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Sample records for thermally coupled distillation

  1. Study of thermally coupled distillation systems for energy-efficient ...

    Indian Academy of Sciences (India)

    Distillation is one of the most widely used separation unit operations in process industries, although it is quite energy intensive. In many cases, the enormous energy requirements for distillation make it economically infeasible to carry out the separation. Thermally coupled distillation system (TCDS) is an advanced distillation ...

  2. Study of thermally coupled distillation systems for energy-efficient ...

    Indian Academy of Sciences (India)

    but also helps reduce emissions associated with the use of the fossil fuels [2]. Thermally coupled distillation system. (TCDS) is one of such configurations. TCDS was first pro- posed by Wright [3] as a divided wall column and later the- oretical studies were performed by Petlyuk et al [4]. The fully thermally coupled distillation ...

  3. Study of thermally coupled distillation systems for energy-efficient ...

    Indian Academy of Sciences (India)

    ponent mixtures. Int. J. Chem. Eng. 5(3): 555–561. [5] Fidkowski Z and Krolikowski L 1987 Minimum energy requirements for thermally coupled distillation systems. AIChE J. 33(4): 643–653. [6] Amminudin K A, Smith R, Thong D Y C and Towler G. P 2001 Design and optimization of fully thermally coupled distillation columns ...

  4. Distillate yield improvement using a parabolic dish reflector coupled single slope basin solar still with thermal energy storage using beeswax

    Directory of Open Access Journals (Sweden)

    Aondoyila KUHE

    2016-07-01

    Full Text Available A single slope solar still, integrated with latent heat thermal energy storage system coupled to a parabolic concentrator was designed with the aim of improving productivity. 14 kg of beeswax was used as phase change material (PCM between the absorber plate and the bottom of the still to keep the operating temperature of the still high enough to produce distilled water even during the sunset hours. The bottom of the still is covered by 0.2 m aluminum sheet painted black on the side facing the parabolic concentrator to help in absorbing solar radiation reflected from the parabolic concentrator and conducting same to the PCM. To determine the effect of PCM, a solar still without PCM was used to compare with the solar still with PCM. The temperature of water, air temperature, inner surface glass temperature and outer surface glass temperature were measured. Experimental results show that the effect of thermal storage in the parabolic concentrator-coupled single slope solar still increased the productivity by 62%.

  5. Renewable water: Direct contact membrane distillation coupled with solar ponds

    International Nuclear Information System (INIS)

    Suárez, Francisco; Ruskowitz, Jeffrey A.; Tyler, Scott W.; Childress, Amy E.

    2015-01-01

    Highlights: • Experimental investigation of direct contact membrane distillation driven by solar ponds. • The DCMD/SGSP system treats ∼6 times the water flow treated by an AGMD/SGSP system. • Half of the energy extracted from the SGSP was used to transport water across the membrane. • Reducing heat losses through the DCMD/SGSP system would yield higher water fluxes. - Abstract: Desalination powered by renewable energy sources is an attractive solution to address the worldwide water-shortage problem without contributing significant to greenhouse gas emissions. A promising system for renewable energy desalination is the utilization of low-temperature direct contact membrane distillation (DCMD) driven by a thermal solar energy system, such as a salt-gradient solar pond (SGSP). This investigation presents the first experimental study of fresh water production in a coupled DCMD/SGSP system. The objectives of this work are to determine the experimental fresh water production rates and the energetic requirements of the different components of the system. From the laboratory results, it was found that the coupled DCMD/SGSP system treats approximately six times the water flow treated by a similar system that consisted of an air–gap membrane distillation unit driven by an SGSP. In terms of the energetic requirements, approximately 70% of the heat extracted from the SGSP was utilized to drive thermal desalination and the rest was lost in different locations of the system. In the membrane module, only half of the useful heat was actually used to transport water across the membrane and the remainder was lost by conduction in the membrane. It was also found that by reducing heat losses throughout the system would yield higher water fluxes, pointing out the need to improve the efficiency throughout the DCMD/SGSP coupled system. Therefore, further investigation of membrane properties, insulation of the system, or optimal design of the solar pond must be addressed in

  6. Renewable Water: Direct Contact Membrane Distillation Coupled With Solar Ponds

    Science.gov (United States)

    Suarez, F. I.; Tyler, S. W.; Childress, A. E.

    2010-12-01

    The exponential population growth and the accelerated increase in the standard of living have increased significantly the global consumption of two precious resources: water and energy. These resources are intrinsically linked and are required to allow a high quality of human life. With sufficient energy, water may be harvested from aquifers, treated for potable reuse, or desalinated from brackish and seawater supplies. Even though the costs of desalination have declined significantly, traditional desalination systems still require large quantities of energy, typically from fossil fuels that will not allow these systems to produce water in a sustainable way. Recent advances in direct contact membrane distillation can take advantage of low-quality or renewable heat to desalinate brackish water, seawater or wastewater. Direct contact membrane distillation operates at low pressures and can use small temperature differences between the feed and permeate water to achieve a significant freshwater production. Therefore, a much broader selection of energy sources can be considered to drive thermal desalination. A promising method for providing renewable source of heat for direct contact membrane distillation is a solar pond, which is an artificially stratified water body that captures solar radiation and stores it as thermal energy at the bottom of the pond. In this work, a direct contact membrane distillation/solar pond coupled system is modeled and tested using a laboratory-scale system. Freshwater production rates on the order of 2 L day-1 per m2 of solar pond (1 L hr-1 per m2 of membrane area) can easily be achieved with minimal operating costs and under low pressures. While these rates are modest, they are six times larger than those produced by other solar pond-powered desalination systems - and they are likely to be increased if heat losses in the laboratory-scale system are reduced. Even more, this system operates at much lower costs than traditional desalination

  7. The Coupling Study for Solar Heating System and Membrane Distillation System

    Science.gov (United States)

    Yan, Suying; Zhang, Tao; Professor, Rui Tian; WeiZhang, Wei

    In this paper, it was simplified that the heating system of thermal mass in solar membrane distillation and it was established that the physical model of heat transfer installed the guide plate in the all-glass thermal solar membrane distillation system. The model included the all-glass solar heat collector system and the hot chamber of membrane distillation system. In this paper, it was constructed that the coupling integration points between the two parts and reached setting methods for coupled boundary conditions and unsteady-state flow. It was established that an unsteady three-dimensional CFD model for solar membrane distillation system and drawn solution and ideas and reached the variation law of fluid temperature and flow rate in outlet of fluid connection changes in solar collector system. It was calculated that the coupling model of hot chamber in membrane distillation and obtained the variation law between non-steady-state flux and solar radiation intensity and laid the foundation for coupling utilization of solar energy with membrane distillation.

  8. Comparison of energy expenditure and closed-loop performance of thermal and reactive distillation sequences coupled for biodiesel production; Comparacion de gasto energetico y desempeno a lazo cerrado de secuencias de destilacion reactiva y termicamente acopladas para produccion de biodiesel

    Energy Technology Data Exchange (ETDEWEB)

    Cornejo-Jacob, J.L [Universidad Michoacana de San Nicolas de Hidalgo, Morelia, Michoacan (Mexico); Vazquez-Ojeda, M; Segovia-Hernandez, J.G; Hernandez, S [Universidad de Guanajuato, Guanajuato, Guanajuato (Mexico); Maya-Yescas, R. [Universidad Michoacana de San Nicolas de Hidalgo, Morelia, Michoacan (Mexico)]. E-mail: rmayay@umich.mx

    2013-03-15

    Biodiesel is the common name for fatty acid methyl esters, obtained by esterification (basic catalysis) or trans-esterification (acid catalysis) of vegetable or animal oils with alcohols, and used as liquid fuel. Production involves the reaction, under mild conditions, between the oil and, typically, excess of methanol. Traditional production of biodiesel exhibits some handicaps, such as the shift of equilibrium to fatty acids by using excess of alcohol that must be separated and recycled. As alternative, it is possible to integrate reaction/separation operations into a single intensified unit, a reactive distillation column, followed by a second separation unit. These configurations exhibit several advantages such as shifting equilibrium in the reactive region and, because of the thermal integration with the second unit, energy savings during products separation. In order to design these production sequences taking advantage of steady state knowledge (energy savings) and considering dynamic performance, this work performs a controllability analysis for six possible configurations; open-loop control properties, evaluated by single value decomposition, are probed by implementing PI controllers to the system. The reactive distillation column coupled to a stripper, without reboilers, shows to be the best option in terms of closed-loop performance and energy savings. [Spanish] Biodiesel es el nombre comun dado a metil esteres de acidos grasos obtenidos por esterificacion (catalisis basica) o trans-esterificacion (catalisis acida) de aceites animales o vegetales con alcoholes, y usados como combustibles liquidos. Su produccion involucra la reaccion entre el aceite y, tipicamente, exceso de metanol a condiciones moderadas. La produccion tradicional de biodiesel exhibe algunas desventajas como el desplazamiento del equilibrio hacia acidos grasos debido al exceso de alcohol, que debe ser separado y reciclado. Alternativamente, es posible integrar las operaciones reaccion

  9. Simulation of vacuum membrane distillation coupled with solar energy

    International Nuclear Information System (INIS)

    Zrelli, Adel; Chaouchi, Bechir; Gabsi, Slimane

    2009-01-01

    This work focuses on solar energy coupled with vacuum membrane distillation (VMD) for brackish water desalination. VMD is an evaporative process, using porous and hydrophobic membranes, permit to obtain the gaseous permeate, under vacuum, from the aqueous liquid feed. The aim of this work was to simulate the influence of operating conditions (feed flow, feed temperature, permeate pressure) and hollow fibres membrane characteristics (pitch, radius of curvature) on the permeate flux. In order to enhance the performance of the VMD process in desalination to get more permeate flux, we have choose a new module, placed in the absorber of the cylindro-parabolic concentrator, containing hollow fibres wrapped around rod in helical geometry. The model formulation allows for variation of the physical characteristics of brackish solution and the water permeability of membrane. The numerical results showed the important effect of the helical geometry on the enhancement of the permeate flux.

  10. Novel thermal efficiency-based model for determination of thermal conductivity of membrane distillation membranes

    International Nuclear Information System (INIS)

    Vanneste, Johan; Bush, John A.; Hickenbottom, Kerri L.; Marks, Christopher A.; Jassby, David

    2017-01-01

    Development and selection of membranes for membrane distillation (MD) could be accelerated if all performance-determining characteristics of the membrane could be obtained during MD operation without the need to recur to specialized or cumbersome porosity or thermal conductivity measurement techniques. By redefining the thermal efficiency, the Schofield method could be adapted to describe the flux without prior knowledge of membrane porosity, thickness, or thermal conductivity. A total of 17 commercially available membranes were analyzed in terms of flux and thermal efficiency to assess their suitability for application in MD. The thermal-efficiency based model described the flux with an average %RMSE of 4.5%, which was in the same range as the standard deviation on the measured flux. The redefinition of the thermal efficiency also enabled MD to be used as a novel thermal conductivity measurement device for thin porous hydrophobic films that cannot be measured with the conventional laser flash diffusivity technique.

  11. Process intensification by coupling the Joule effect with pervaporation and sweeping gas membrane distillation

    NARCIS (Netherlands)

    Shukla, S.; Méricq, J. P.; Belleville, M.P.; Hengl, N.; Benes, N. E.; Vankelecom, I.; Sanchez Marcano, Jose

    2018-01-01

    This work concerns the intensification of membrane processes by coupling the Joule effect with two membrane processes: pervaporation and sweeping gas membrane distillation. For this purpose, conducting metallic hollow fibers impregnated or coated with polydimethyl siloxane were simultaneously used

  12. Thermal distillation system utilizing biomass energy burned in stove by means of heat pipe

    Directory of Open Access Journals (Sweden)

    Hiroshi Tanaka

    2016-09-01

    Full Text Available A thermal distillation system utilizing a part of the thermal energy of biomass burned in a stove during cooking is proposed. The thermal energy is transported from the stove to the distiller by means of a heat pipe. The distiller is a vertical multiple-effect diffusion distiller, in which a number of parallel partitions in contact with saline-soaked wicks are set vertically with narrow gaps of air. A pilot experimental apparatus was constructed and tested with a single-effect and multiple-effect distillers to investigate primarily whether a heat pipe can transport thermal energy adequately from the stove to the distiller. It was found that the temperatures of the heated plate and the first partition of the distiller reached to about 100 °C and 90 °C, respectively, at steady state, showing that the heat pipe works sufficiently. The distilled water obtained was about 0.75 and 1.35 kg during the first 2 h of burning from a single-effect and multiple-effect distillers, respectively.

  13. On Entropy Generation and the Effect of Heat and Mass Transfer Coupling in a Distillation Process

    Science.gov (United States)

    Burgos-Madrigal, Paulina; Mendoza, Diego F.; López de Haro, Mariano

    2018-01-01

    The entropy production rates as obtained from the exergy analysis, entropy balance and the nonequilibrium thermodynamics approach are compared for two distillation columns. The first case is a depropanizer column involving a mixture of ethane, propane, n-butane and n-pentane. The other is a weighed sample of Mexican crude oil distilled with a pilot scale fractionating column. The composition, temperature and flow profiles, for a given duty and operating conditions in each column, are obtained with the Aspen Plus V8.4 software by using the RateFrac model with a rate-based nonequilibrium column. For the depropanizer column the highest entropy production rate is found in the central trays where most of the mass transfer occurs, while in the second column the highest values correspond to the first three stages (where the vapor mixture is in contact with the cold liquid reflux), and to the last three stages (where the highest temperatures take place). The importance of the explicit inclusion of thermal diffusion in these processes is evaluated. In the depropanizer column, the effect of the coupling between heat and mass transfer is found to be negligible, while for the fractionating column it becomes appreciable.

  14. Electrical Thermal Network for Direct Contact Membrane Distillation Modeling and Analysis

    KAUST Repository

    Karam, Ayman M.

    2015-02-04

    Membrane distillation is an emerging water distillation technology that offers several advantages compared to conventional water desalination processes. Although progress has been made to model and understand the physics of the process, many studies are based on steady-state assumptions or are computationally not appropriate for real time control. This paper presents the derivation of a novel dynamical model, based on analogy between electrical and thermal systems, for direct contact membrane distillation (DCMD). The proposed model captures the dynamics of temperature distribution and distilled water flux. To demonstrate the adequacy of the proposed model, validation with transient and steady-state experimental data is presented.

  15. STUDY OF THE THERMAL CRACKING DURING THE VACUUM DISTILLATION OF ATMOSPHERIC RESIDUE OF CRUDE OIL

    Directory of Open Access Journals (Sweden)

    JAOUAD ELAYANE

    2017-03-01

    Full Text Available This article concerns the study of the thermal cracking as undesirable phenomenon in the vacuum distillation of atmospheric residue of crude oil. In this point, we have sought to identify and characterize the effect of the increase in the temperature of vacuum distillation on the separation and the modification of the constituents of atmospheric residue of crude oil whose origin is Arabian Light. This study has been carried out by several techniques of analysis such as the density (ASTM D4052, distillation (ASTM D1160, determination of heavy metals nickel and vanadium (IFP9422, dosing of Conradson Carbon (ASTM D189, dosing of asphaltenes (ASTM D2549 and dosage of PCI (polycyclic aromatics (ASTM D 5186. The results showed a clear idea on the decomposition of the atmospheric residue and their influence on the performance of the vacuum distillation unit.

  16. Production of Bioethanol from Agricultural Wastes Using Residual Thermal Energy of a Cogeneration Plant in the Distillation Phase

    Directory of Open Access Journals (Sweden)

    Raffaela Cutzu

    2017-05-01

    Full Text Available Alcoholic fermentations were performed, adapting the technology to exploit the residual thermal energy (hot water at 83–85 °C of a cogeneration plant and to valorize agricultural wastes. Substrates were apple, kiwifruit, and peaches wastes; and corn threshing residue (CTR. Saccharomyces bayanus was chosen as starter yeast. The fruits, fresh or blanched, were mashed; CTR was gelatinized and liquefied by adding Liquozyme® SC DS (Novozymes, Dittingen, Switzerland; saccharification simultaneous to fermentation was carried out using the enzyme Spirizyme® Ultra (Novozymes, Dittingen, Switzerland. Lab-scale static fermentations were carried out at 28 °C and 35 °C, using raw fruits, blanched fruits and CTR, monitoring the ethanol production. The highest ethanol production was reached with CTR (10.22% (v/v and among fruits with apple (8.71% (v/v. Distillations at low temperatures and under vacuum, to exploit warm water from a cogeneration plant, were tested. Vacuum simple batch distillation by rotary evaporation at lab scale at 80 °C (heating bath and 200 mbar or 400 mbar allowed to recover 93.35% (v/v and 89.59% (v/v of ethanol, respectively. These results support a fermentation process coupled to a cogeneration plant, fed with apple wastes and with CTR when apple wastes are not available, where hot water from cogeneration plant is used in blanching and distillation phases. The scale up in a pilot plant was also carried out.

  17. Fluid-structure thermal coupling

    Energy Technology Data Exchange (ETDEWEB)

    Hyun, J. [Adtech, N3S, Tokyo (Japan); Gasser, D. [Simulog, N3S, Estet, Simail, 78 - Saint Quentin en Yvelyne (France)

    1997-12-31

    On many occasions thermal exchange takes place between a structure and a fluid flowing in its neighbourhood. Such phenomena can be very complex, and numerical simulation is then an interesting means to understand them better. In that context, SIMULOG simulated the air flow around a radiator using the coupled numerical codes N3S and SYRTHES, which are developed at EDF/LNH. While N3S computes the air flow and thermal convection around the radiator`s fins, SYRTHES computes heat conduction in the radiator. The N3S-SYRTHES coupling process takes into account the heat transfer at the fluid/solid interface. Two computations were performed, corresponding to air flow rates values between the fins of 0.0518 m{sup 3}/s and 0.0865 m{sup 3}/s, and a radiator temperature of 40 deg C, the air flows along the Z axis from the bottom to the top of the radiator. A rise in temperature, along the Z axis, takes place in the air and in the radiator. The maximum temperature reached inside the radiator is 55 deg C for the lowest flow and 51 deg C for the highest one. The average decrease of the air and radiator temperature is about 5 deg C when the flow rate raises from 0.0518 m{sup 3}/s to 0.0865 m{sup 3}/s. Such a simulation gives important information for the conception and the performance evaluation of this process where the main objective is to control the maximum temperature. (authors)

  18. Electrical equivalent thermal network for direct contact membrane distillation modeling and analysis

    KAUST Repository

    Karam, Ayman M.

    2016-09-19

    Membrane distillation (MD) is an emerging water desalination technology that offers several advantages compared to conventional desalination methods. Although progress has been made to model the physics of the process, there are two common limitations of existing models. Firstly, many of the models are based on the steady-state analysis of the process and secondly, some of the models are based on partial differential equations, which when discretized introduce many states which are not accessible in practice. This paper presents the derivation of a novel dynamic model, based on the analogy between electrical and thermal systems, for direct contact membrane distillation (DCMD). An analogous electrical thermal network is constructed and its elements are parameterized such that the response of the network models the DCMD process. The proposed model captures the spatial and temporal responses of the temperature distribution along the flow direction and is able to accurately predict the distilled water flux output. To demonstrate the adequacy of the proposed model, validation with time varying and steady-state experimental data is presented. (C) 2016 Elsevier Ltd. All rights reserved.

  19. Batch pervaporative fermentation with coupled membrane and its influence on energy consumption in permeate recovery and distillation stage

    International Nuclear Information System (INIS)

    Leon, Juan A.; Palacios-Bereche, Reynaldo; Nebra, Silvia A.

    2016-01-01

    In the ethanol production process from sugarcane molasses, the distillation process is a high-energy demand stage. The distillation energy efficiency is strongly associated with the alcoholic fermentation performance in the process. The final ethanol concentration in the alcoholic wines has a direct impact on consumption of thermal energy in ethanol separation. In this paper, ethanol production with a H-SBMF (Hybrid-Simple Batch Membrane Fermenter) using PDMS (polydimethylsiloxane) pervaporation membrane was modelled and simulated, in order to determine its influence on energy consumption in distillation. Steam in distillation and electrical energy needs in permeate recovery were mainly influenced by membrane adaptation. The H-SBMF achieved a higher ethanol production in the range of 10–13% compared to the conventional batch fermenter, and an increase in productivity of 150%. The distillation system consisted of two sets of columns: the ethanol recovery column and the rectification column. The permeate recovery system (i.e. vacuum and compression) was regarded in order to evaluate the electrical energy requirement, and the thermal energy demand was evaluated. A decrease in steam consumption was evidenced by the adaptation of the membrane to the fermenter. Higher energy efficiencies were achieved in distillation with larger membrane areas, achieving almost 17% steam reduction. - Highlights: • Higher and faster ethanol productions were achieved by fermenter hybridization. • Multi-stage permeate compression and inter-stage heat recovery were assumed. • Energy demand was studied based on an integrated fermentation and distillation scheme. • High-energy efficiency was attained in the distillation to produce hydrated alcohol.

  20. Analysis of Thermal Properties on Backward Feed Multi effect Distillation Dealing with High-Salinity Wastewater

    International Nuclear Information System (INIS)

    Xue, J.; Ming, J.; Li, L.; Cui, Q.; Bai, Y.

    2015-01-01

    Theoretical investigations on thermal properties of multi effect distillation (MED) are presented to approach lower capital costs and more distillated products. A mathematical model, based on the energy and mass balance, is developed to (i) evaluate the influences of variations in key parameters (effect numbers, evaporation temperature in last effect, and feed salinity) on steam consumption, gained output ratio (GOR), and total heat transfer areas of MED and (II) compare two operation modes (backward feed (BF) and forward feed (FF) systems). The result in the first part indicated that GOR and total heat transfer areas increased with the effect numbers. Also, higher effect numbers result in the fact that the evaporation temperature in last effect has slight influence on GOR, while it influences the total heat transfer areas remarkably. In addition, an increase of feed salinity promotes the total heat transfer areas but reduces GOR. The analyses in the second part indicate that GOR and total heat transfer areas of BF system are higher than those in FF system. One thing to be aware of is that the changes of steam consumption can be omitted, considering that it shows an opposite trend to GOR.

  1. Non-thermal Production of Natural betalain Colorant Concentrate from Red Beet Extract by Using the Osmotic Distillation

    Directory of Open Access Journals (Sweden)

    Nazanin Amirasgari

    2016-04-01

    Full Text Available Background and Objectives: Red beet extract concentrate can be used as a natural colorant in food products; however, destructive effects of thermal methods to produce juice concentrate decrease nutritional value in the final product. Materials and Methods: In this study, red beet extract was concentrated using osmotic distillation method, and the best pretreatment was evaluated to increase the efficiency of the concentration process. Also changes in some physicochemical properties such as betacyanins and betaxanthins contents, total phenolic compounds and antioxidant activity of red beet juice were evaluated by both the membrane and thermal concentration methods. Results: The results showed that the best concentration efficiency was obtained after pretreatment of the fresh juice with centrifugation at 1699 G for 17 min. Evaluation of the effect of both the membrane and thermal concentration processes on the physicochemical properties of juice showed that the membrane method did not change betacyanin and betaxanthin contents, total phenolic compounds, and antioxidant activity of the red beet extract. However, these properties decreased with the thermal concentration method by 26, 15, 11 and 13%, respectively. Conclusions: According to the results, osmotic distillation can produce red beet concentrate with more nutritional value than the concentrate produced with thermal method. Keywords: Membrane, Natural betalain colorant, Osmotic distillation, Red beet

  2. Distillation irrigation: a low-energy process for coupling water purification and drip irrigation

    Science.gov (United States)

    Constantz, J.

    1989-01-01

    A method is proposed for combining solar distillation and drip irrigation to simultaneously desalinize water and apply this water to row crops. In this paper, the basic method is illustrated by a simple device constructed primarily of sheets of plastic, which uses solar energy to distill impaired water and apply the distillate to a widely spaced row crop. To predict the performance of the proposed device, an empirical equation for distillate production, dp, is developed from reported solar still production rates, and a modified Jensen-Haise equation is used to calculate the potential evapotranspiration, et, for a row crop. Monthly values for et and dp are calculated by using a generalized row crop at five locations in the Western United States. Calculated et values range from 1 to 22 cm month-1 and calculated dp values range from 2 to 11 cm month-1, depending on the location, the month, and the crop average. When the sum of dp plus precipitation, dp + P, is compared to et for the case of 50% distillation irrigation system coverage, the results indicate that the crop's et is matched by dp + P, at the cooler locations only. However, when the system coverage is increased to 66%, the crop's et is matched by dp + P even at the hottest location. Potential advantages of distillation irrigation include the ability: (a) to convert impaired water resources to water containing no salts or sediments; and (b) to efficiently and automatically irrigate crops at a rate that is controlled primarily by radiation intensities. The anticipated disadvantages of distillation irrigation include: (a) the high costs of a system, due to the large amounts of sheeting required, the short lifetime of the sheeting, and the physically cumbersome nature of a system; (b) the need for a widely spaced crop to reduce shading of the system by the crop; and (c) the production of a concentrated brine or precipitate, requiring proper off-site disposal. ?? 1989.

  3. Study of the Formation of Eutectic Melt of Uranium and Thermal Analysis for the Salt Distillation of Uranium Deposits

    International Nuclear Information System (INIS)

    Park, Sung Bin; Hwang, Sung Chan; Kang, Young Ho; Park, Ki Min; Jun, Wan Gi; Lee, Han Soo; Cho, Dong Wook

    2010-01-01

    Uranium deposits from an electrorefining process contain about 30% salt. In order to recover pure uranium and transform it into an ingot, the salts have to be removed from the uranium deposits. Major process variables for the salt distillation process of the uranium deposits are hold temperature and vacuum pressure. Effects of the variables on the salt removal efficiency were studied in the previous study 1. By applying the Hertz-Langmuir relation to the salt evaporation of the uranium deposits, the evaporation coefficients were obtained at the various conditions. The operational conditions for achieving above 99% salt removal were deduced. The salt distilled uranium deposits tend to form the eutectic melt with iron, nickel, chromium for structural material of salt evaporator. In this study, we investigated the hold temperature limitation in order to prevent the formation of the eutectic melt between uranium and other metals. The reactions between the uranium metal and stainless steel were tested at various conditions. And for enhancing the evaporation rate of the salt and the efficient recovery of the distilled salt, the thermal analysis of the salt distiller was conducted by using commercial CFX software. From the thermal analysis, the effect of Ar gas flow on the evaporation of the salt was studied.

  4. The setup of an extraction system coupled to a hydrogen isotopes distillation column

    International Nuclear Information System (INIS)

    Zamfirache, M.; Bornea, A.; Stefanescu, I.; Bidica, N.; Balteanu, O.; Bucur, C.

    2008-01-01

    Among the most difficult problems of cryogenic distillation one stands apart: the extraction of the heavy fraction. By an optimal design of the cycle scheme, this problem could be avoided. A 'worst case scenario' is usually occurring when the extracted fraction consists of one prevalent isotope such as hydrogen and small amounts of the other two hydrogen isotopes (deuterium and/or tritium). This situation is further complicated by two parameters of the distillation column: the extraction flow rate and the hold-up. The present work proposes the conceptual design of an extraction system associated to the cryogenic distillation column used in hydrogen separation processes. During this process, the heavy fraction (DT, T 2 ) is separated, its concentration being the highest at the bottom of the distillation column. From this place the extraction of the gaseous phase can now begin. Being filled with adsorbent, the extraction system is used to temporarily store the heavy fraction. Also the extraction system provides samples for the gas Chromatograph. The research work is focused on the existent pilot plant for tritium and deuterium separation from our institute to validate the experiments carried out until now. (authors)

  5. Identification of volatile compounds in Chrysanthemum morifolium by microwave distillation solid-phase microextraction coupled with GC/MS.

    Science.gov (United States)

    Zhou, Tao; Yang, Bei; Zhang, Haiying; Yu, Yingjia; Chen, Bin; Chen, Yile; Duan, Gengli

    2009-01-01

    Microwave distillation with concomitant solid-phase microextraction (MD-SPME) coupled with GC/MS was developed for identifying volatile compounds in the dried flowers of Chrysanthemum morifolium (CM). Different experimental parameters, including SPME fiber coating, microwave power, irradiation time, and water volume were optimized. The best results were obtained using carboxen/polydimethylsiloxane fiber with microwave irradiation at 400 W for 3 min and the addition of 1 mL water into 1.0 g sample. The proposed method allowed the isolation, extraction, and concentration of volatile compounds to be completed in a single step. This MD-SPME-GC/MS method has also been compared to the conventional steam distillation method followed by GC/MS for this identification. Thirty-two volatile compounds were identified using the newly developed MD-SPME-GC/MS process. Relative standard deviation values of steam distillation-GC/MS. Therefore, the proposed MD-SPME-GC/MS method is simple, rapid, and efficient for identifying volatile compounds in CM.

  6. Detection of trace fluoride in serum and urine by online membrane-based distillation coupled with ion chromatography.

    Science.gov (United States)

    Lou, Chaoyan; Guo, Dandan; Wang, Nani; Wu, Shuchao; Zhang, Peimin; Zhu, Yan

    2017-06-02

    An online membrane-based distillation (MBD) coupled with ion chromatography (IC) method was proposed for automatic detection of trace fluoride (F - ) in serum and urine samples. The system consisted of a sample vessel, a lab-made membrane module and an ion chromatograph. Hydrophobic polytetrafluoroethylene (PTFE) hollow fiber membrane was used in MBD which was directly performed in serum and urine samples to eliminate the matrix interferences and enrich fluoride, while enabling automation. The determination of fluoride in biological samples was carried out by IC with suppressed conductometric detection. The proposed method feasibly determined trace fluoride in serum and urine matrices with the optimized parameters, such as acid concentration, distillation temperature, and distillation time, etc. Fluoride exhibited satisfactory linearity in the range of 0.01-5.0mg/L with a correlation coefficient of 0.9992. The limit of detection (LOD, S/N=3) and limit of quantification (LOQ, S/N=10) were 0.78μg/L and 2.61μg/L, respectively. The relative standard deviations of peak area and peak height were all less than 5.15%. The developed method was validated for the determination of fluoride in serum and urine with good spiked recoveries ranging between 97.1-101.9%. This method also can be proposed as a suitable alternative for the analysis of fluoride in other complex biological samples. Copyright © 2017. Published by Elsevier B.V.

  7. Thermal coupling at aqueous and biomolecular interfaces

    Science.gov (United States)

    Shenogina, Natalia B.

    Heat flow in the materials with nanoscopic features is dominated by thermal properties of the interfaces. While thermal properties of the solid-solid and solid-liquid interfaces are well studied, research of the thermal transport properties across soft (liquid-liquid) interfaces is very limited. Such interfaces are, however, plentiful in biological systems. In such systems the temperature control is of a great importance, because biochemical reactions, conformation of biomolecules as well as processes in biological cells and membranes have strong temperature sensitivity. The critical ingredient to temperature control in biological systems is the understanding of heat flow and thermal coupling across soft interfaces. To investigate heat transfer across biological and aqueous interfaces we chose to study a number of soft interfacial systems by means of molecular dynamic simulations. One of the interfaces under our investigation is the interface between protein (specifically green fluorescent protein) and water. Using this model we concentrated on the importance of vibrational frequency on coupling between water and proteins, and on significant differences between the roles of low and high frequency vibrations. Our thermal interfacial analysis allowed us to shed new light on to the issue of protein to water slaving, i.e., the concept of water controlling protein dynamics. Considering that the surface of the protein is composed of a complicated mixture of the hydrophobic and hydrophilic domains, to systematically explore the role of interfacial interactions we studied less complicated models with homogenous interfaces whith interfacial chemistry that could be changed in a controlled manner. We demonstrated that thermal transport measurements can be used to probe interfacial environments and to quantify interfacial bonding strength. Such ability provides a unique opportunity to characterize a variety of interfaces, which can be difficult to achieve with more direct

  8. Synthesis report on thermally driven coupled processes

    Energy Technology Data Exchange (ETDEWEB)

    Hardin, E.L.

    1997-10-15

    The main purpose of this report is to document observations and data on thermally coupled processes for conditions that are expected to occur within and around a repository at Yucca Mountain. Some attempt is made to summarize values of properties (e.g., thermal properties, hydrologic properties) that can be measured in the laboratory on intact samples of the rock matrix. Variation of these properties with temperature, or with conditions likely to be encountered at elevated temperature in the host rock, is of particular interest. However, the main emphasis of this report is on direct observation of thermally coupled processes at various scales. Direct phenomenological observations are vitally important in developing and testing conceptual models. If the mathematical implementation of a conceptual model predicts a consequence that is not observed, either (1) the parameters or the boundary conditions used in the calculation are incorrect or (2) the conceptual basis of the model does not fit the experiment; in either case, the model must be revised. For example, the effective continuum model that has been used in thermohydrology studies combines matrix and fracture flow in a way that is equivalent to an assumption that water is imbibed instantaneously from fractures into adjacent, partially saturated matrix. Based on this approximation, the continuum-flow response that is analogous to fracture flow will not occur until the effective continuum is almost completely saturated. This approximation is not entirely consistent with some of the experimental data presented in this report. This report documents laboratory work and field studies undertaken in FY96 and FY97 to investigate thermally coupled processes such as heat pipes and fracture-matrix coupling. In addition, relevant activities from past years, and work undertaken outside the Yucca Mountain project are summarized and discussed. Natural and artificial analogs are also discussed to provide a convenient source of

  9. Thermal quench at finite 't Hooft coupling

    Directory of Open Access Journals (Sweden)

    H. Ebrahim

    2016-03-01

    Full Text Available Using holography we have studied thermal electric field quench for infinite and finite 't Hooft coupling constant. The set-up we consider here is D7-brane embedded in (α′ corrected AdS-black hole background. It is well-known that due to a time-dependent electric field on the probe brane, a time-dependent current will be produced and it will finally relax to its equilibrium value. We have studied the effect of different parameters of the system on equilibration time. As the most important results, for massless fundamental matter, we have observed a universal behaviour in the rescaled equilibration time in the very fast quench regime for different values of the temperature and α′ correction parameter. It seems that in the slow quench regime the system behaves adiabatically. We have also observed that the equilibration time decreases in finite 't Hooft coupling limit.

  10. Coupling Geothermal Heat Pumps with Underground Seasonal Thermal Energy Storage

    Science.gov (United States)

    2017-03-21

    EW-201135) Coupling Geothermal Heat Pumps with Underground Seasonal Thermal Energy Storage March 2017 This document has been cleared for...09/2011-03/2017 4. TITLE AND SUBTITLE Coupling Geothermal Heat Pumps with Underground Seasonal Thermal Energy Storage 5a...v ACRONYMS AND ABBREVIATIONS AGWT American Ground Water Trust AHU Air Handling Unit ATES Aquifer Thermal Energy Storage BTES Borehole

  11. Dynamic nonlinear thermal optical effects in coupled ring resonators

    Directory of Open Access Journals (Sweden)

    Chenguang Huang

    2012-09-01

    Full Text Available We investigate the dynamic nonlinear thermal optical effects in a photonic system of two coupled ring resonators. A bus waveguide is used to couple light in and out of one of the coupled resonators. Based on the coupling from the bus to the resonator, the coupling between the resonators and the intrinsic loss of each individual resonator, the system transmission spectrum can be classified by three different categories: coupled-resonator-induced absorption, coupled-resonator-induced transparency and over coupled resonance splitting. Dynamic thermal optical effects due to linear absorption have been analyzed for each category as a function of the input power. The heat power in each resonator determines the thermal dynamics in this coupled resonator system. Multiple “shark fins” and power competition between resonators can be foreseen. Also, the nonlinear absorption induced thermal effects have been discussed.

  12. A theoretical study of a direct contact membrane distillation system coupled to a salt-gradient solar pond for terminal lakes reclamation.

    Science.gov (United States)

    Suárez, Francisco; Tyler, Scott W; Childress, Amy E

    2010-08-01

    Terminal lakes are water bodies that are located in closed watersheds with the only output of water occurring through evaporation or infiltration. The majority of these lakes, which are commonly located in the desert and influenced by human activities, are increasing in salinity. Treatment options are limited, due to energy costs, and many of these lakes provide an excellent opportunity to test solar-powered desalination systems. This paper theoretically investigates utilization of direct contact membrane distillation (DCMD) coupled to a salt-gradient solar pond (SGSP) for sustainable freshwater production at terminal lakes. A model for heat and mass transport in the DCMD module and a thermal model for an SGSP were developed and coupled to evaluate the feasibility of freshwater production. The construction of an SGSP outside and inside of a terminal lake was studied. As results showed that freshwater flows are on the same order of magnitude as evaporation, these systems will only be successful if the SGSP is constructed inside the terminal lake so that there is little or no net increase in surface area. For the study site of this investigation, water production on the order of 2.7 x 10(-3) m(3) d(-1) per m(2) of SGSP is possible. The major advantages of this system are that renewable thermal energy is used so that little electrical energy is required, the coupled system requires low maintenance, and the terminal lake provides a source of salts to create the stratification in the SGSP. (c) 2010 Elsevier Ltd. All rights reserved.

  13. Simultaneous concentration and detoxification of lignocellulosic hydrolyzates by vacuum membrane distillation coupled with adsorption.

    Science.gov (United States)

    Zhang, Yaqin; Li, Ming; Wang, Yafei; Ji, Xiaosheng; Zhang, Lin; Hou, Lian

    2015-12-01

    Low sugar concentration and the presence of various inhibitors are the major challenges associated with lignocellulosic hydrolyzates as a fermentation broth. Vacuum membrane distillation (VMD) process can be used to concentrate sugars and remove inhibitors (furans) efficiently, but it's not desirable for the removal of less volatile inhibitors such as acetic acid. In this study, a VMD-adsorption process was proposed to improve the removal of acetic acid, achieving simultaneous concentration and detoxification of lignocellulosic hydrolyzates by one step process. Results showed that sugars were concentrated with high rejections (>98%) and little sugar loss (<2%), with the significant reduction in nearly total furans (99.7%) and acetic acid (83.5%) under optimal operation conditions. Fermentation results showed the ethanol production of hydrolyzates concentrated and detoxified using the VMD-adsorption method were approximately 10-fold greater than from untreated hydrolyzates. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Osmotically and thermally isolated forward osmosis-membrane distillation (fo-md) integrated module for water treatment applications

    KAUST Repository

    Ghaffour, Noreddine

    2016-09-01

    An integrated forward osmosis-membrane distillation (FO-MD) module and systems and methods incorporating the module is disclosed providing higher efficiencies and using less energy. The FO-MD module is osmotically and thermally isolated. The isolation can prevent mixing of FO draw solution/FO permeate and MD feed, and minimize dilution of FO draw solution and cooling of MD feed. The module provides MD feed solution and FO draw solution streams that flow in the same module but are separated by an isolation barrier. The osmotically and thermally isolated FO-MD integrated module, systems and methods offer higher driving forces of both FO and MD processes, higher recovery, and wider application than previously proposed hybrid FO- MD systems.

  15. Coupling of standard condensing nuclear power stations to horizontal aluminium tubes multieffect distillation plants

    International Nuclear Information System (INIS)

    Adar, J.

    1977-01-01

    No large nuclear back-pressure turbines are available to-day. Standard condensing nuclear turbines could operate continuously with a back-pressure of up to 7'' Hg, exhausting huge amounts of steam at 56degC-64degC with a loss of electricity production of only 6%-10%. The horizontal aluminium tube multieffect distillation process developed by 'Israel Desalination Engineering Ltd' is very suitable for the use of such low-grade heat. A special flash-chamber loop constitutes a positive barrier against any possible contamination being carried over by the steam exhausted from the turbine to the desalination plant. The operation is designed to be flexible so that the power plant can be operated either in conjunction with the desalination plant or as a single purpose plant. Flow sheets, heat and mass balances have been prepared for eight different combinations of plants. Only standard equipment is being used in the power plant. The desalination plant consists of 6 to 12 parallel double lines, each of them similar to a large prototype now being designed. Water production varies between 50 and 123 MGD and water cost between 90 and 137 c/1000 gallons. Costs are based on actual bids

  16. Waste Heat Recovery and Recycling in Thermal Separation Processes: Distillation, Multi-Effect Evaporation (MEE) and Crystallization Processes

    Energy Technology Data Exchange (ETDEWEB)

    Emmanuel A. Dada; Chandrakant B. Panchal; Luke K. Achenie; Aaron Reichl; Chris C. Thomas

    2012-12-03

    Evaporation and crystallization are key thermal separation processes for concentrating and purifying inorganic and organic products with energy consumption over 1,000 trillion Btu/yr. This project focused on a challenging task of recovering low-temperature latent heat that can have a paradigm shift in the way thermal process units will be designed and operated to achieve high-energy efficiency and significantly reduce the carbon footprint as well as water footprint. Moreover, this project has evaluated the technical merits of waste-heat powered thermal heat pumps for recovery of latent heat from distillation, multi-effect evaporation (MEE), and crystallization processes and recycling into the process. The Project Team has estimated the potential energy, economics and environmental benefits with the focus on reduction in CO2 emissions that can be realized by 2020, assuming successful development and commercialization of the technology being developed. Specifically, with aggressive industry-wide applications of heat recovery and recycling with absorption heat pumps, energy savings of about 26.7 trillion Btu/yr have been estimated for distillation process. The direct environmental benefits of this project are the reduced emissions of combustible products. The estimated major reduction in environmental pollutants in the distillation processes is in CO2 emission equivalent to 3.5 billion lbs/year. Energy consumption associated with water supply and treatments can vary between 1,900 kWh and 23,700 kWh per million-gallon water depending on sources of natural waters [US DOE, 2006]. Successful implementation of this technology would significantly reduce the demand for cooling-tower waters, and thereby the use and discharge of water treatment chemicals. The Project Team has also identified and characterized working fluid pairs for the moderate-temperature heat pump. For an MEE process, the two promising fluids are LiNO3+KNO3+NANO3 (53:28:19 ) and LiNO3+KNO3+NANO2

  17. One-Shot, reagent-free determination of the alcoholic content of distilled beverages by thermal infrared enthalpimetry.

    Science.gov (United States)

    Oliveira, Alessandra S; Nora, Flávia M Dalla; Mello, Renius O; Mello, Paola A; Tischer, Bruna; Costa, Adilson B; Barin, Juliano S

    2017-08-15

    A simple and fast method is proposed for determining the alcoholic content of distilled beverages by thermal infrared enthalpimetry (TIE), in which purified water is added directly and the temperature rise caused by the heat of dilution is monitored using an infrared camera. A calibration curve was constructed with hydroalcoholic reference solutions to determine the alcoholic content of vodka, whisky, and cachaça. The influence of the total volume of solutions in the reactor, the stirring speed, the dispensing rate, and the ratio between hydroalcoholic samples and water were evaluated to reach an optimum mixture and provide low variation among measurements. Optimized conditions for those respective parameters were 2.4mL, 200rpm, 0.57mLs -1 , and 1:1. To evaluate the accuracy, alcoholic content was also determined by a conventional method (AOAC method 942.06, pycnometry), with agreement ranging from 99.4% to 100.9%. No sample preparation (e.g., dilution or distillation) was required with the proposed method, decreasing the time required for analysis by at least one order of magnitude. The proposed method required less energy consumption by a factor of about three thousand in comparison with the conventional method. The proposed TIE method was robust, able to determine the alcoholic content of diverse distilled beverages. Due to these features and the high sample throughput (up to 480 samples per hour), the proposed method could be considered suitable for routine analysis and agrees with the principles of green analytical chemistry. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Thermal rectification and negative differential thermal conductance in harmonic chains with nonlinear system-bath coupling

    Science.gov (United States)

    Ming, Yi; Li, Hui-Min; Ding, Ze-Jun

    2016-03-01

    Thermal rectification and negative differential thermal conductance were realized in harmonic chains in this work. We used the generalized Caldeira-Leggett model to study the heat flow. In contrast to most previous studies considering only the linear system-bath coupling, we considered the nonlinear system-bath coupling based on recent experiment [Eichler et al., Nat. Nanotech. 6, 339 (2011), 10.1038/nnano.2011.71]. When the linear coupling constant is weak, the multiphonon processes induced by the nonlinear coupling allow more phonons transport across the system-bath interface and hence the heat current is enhanced. Consequently, thermal rectification and negative differential thermal conductance are achieved when the nonlinear couplings are asymmetric. However, when the linear coupling constant is strong, the umklapp processes dominate the multiphonon processes. Nonlinear coupling suppresses the heat current. Thermal rectification is also achieved. But the direction of rectification is reversed compared to the results of weak linear coupling constant.

  19. Optimal design of advanced distillation configuration for enhanced energy efficiency of waste solvent recovery process in semiconductor industry

    International Nuclear Information System (INIS)

    Chaniago, Yus Donald; Minh, Le Quang; Khan, Mohd Shariq; Koo, Kee-Kahb; Bahadori, Alireza; Lee, Moonyong

    2015-01-01

    Highlights: • Thermally coupled distillation process is proposed for waste solvent recovery. • A systematic optimization procedure is used to optimize distillation columns. • Response surface methodology is applied to optimal design of distillation column. • Proposed advanced distillation allows energy efficient waste solvent recovery. - Abstract: The semiconductor industry is one of the largest industries in the world. On the other hand, the huge amount of solvent used in the industry results in high production cost and potential environmental damage because most of the valuable chemicals discharged from the process are incinerated at high temperatures. A distillation process is used to recover waste solvent, reduce the production-related costs and protect the environment from the semiconductor industrial waste. Therefore, in this study, a distillation process was used to recover the valuable chemicals from semiconductor industry discharge, which otherwise would have been lost to the environment. The conventional sequence of distillation columns, which was optimized using the Box and sequential quadratic programming method for minimum energy objectives, was used. The energy demands of a distillation problem may have a substantial influence on the profitability of a process. A thermally coupled distillation and heat pump-assisted distillation sequence was implemented to further improve the distillation performance. Finally, a comparison was made between the conventional and advanced distillation sequences, and the optimal conditions for enhancing recovery were determined. The proposed advanced distillation configuration achieved a significant energy saving of 40.5% compared to the conventional column sequence

  20. Analysis of volatile components from Ziziphora taurica subsp. taurica by steam distillation, superheated-water extraction, and direct thermal desorption with GCxGC-TOFMS.

    Science.gov (United States)

    Ozel, Mustafa Z; Göğüş, Fahrettin; Hamilton, Jacqueline F; Lewis, Alastair C

    2005-05-01

    Volatile components from the leaves of Ziziphora taurica subsp. taurica have been isolated by steam distillation, superheated-water extraction, and direct thermal desorption techniques. The volatile components were characterized by comprehensive two dimensional gas chromatography-time of flight mass spectrometry. The extraction yields from Z. taurica leaves were found to be 1.56% and 1.32% for steam distillation and superheated-water extraction respectively. The major compounds found in the volatile fractions of the leaves of Z. taurica were pulegone, terpinen-4-ol, cis-carveol, trans-carveol, and verbenone. The number of volatile components identified were 28, 30, and 41 for steam distillation, superheated-water extraction, and direct thermal desorption, respectively.

  1. Recovery of salts from ion-exchange regeneration streams by a coupled nanofiltration-membrane distillation process.

    Science.gov (United States)

    Jiříček, Tomáš; De Schepper, Wim; Lederer, Tomáš; Cauwenberg, Peter; Genné, Inge

    2015-01-01

    Ion-exchange tap water demineralization for process water preparation results in a saline regeneration wastewater (20-100 mS cm(-1)) that is increasingly problematic in view of discharge. A coupled nanofiltration-membrane distillation (NF-MD) process is evaluated for the recovery of water and sodium chloride from this wastewater. NF-MD treatment of mixed regeneration wastewater is compared to NF-MD treatment of separate anion- and cation-regenerate fractions. NF on mixed regeneration wastewater results in a higher flux (30 L m(-2) h(-1) at 7 bar) compared to NF on the separate fractions (6-9 L m(-2) h(-1) at 30 bar). NF permeate recovery is strongly limited by scaling (50% for separate and 60% for mixed, respectively). Physical signs of scaling were found during MD treatment of the NF permeates but did not result in flux decline for mixed regeneration wastewater. Final salt composition is expected to qualify as a road de-icing salt. NF-MD is an economically viable alternative compared to external disposal of wastewater for larger-scale installations (1.4 versus 2.5 euro m(-3) produced demineralized water for a 10 m3 regenerate per day plant). The cost benefits of water re-use and salt recuperation are small when compared to total treatment costs for mixed regenerate wastewater.

  2. A New Hybrid BFOA-PSO Optimization Technique for Decoupling and Robust Control of Two-Coupled Distillation Column Process

    Directory of Open Access Journals (Sweden)

    Noha Abdelkarim

    2016-01-01

    Full Text Available The two-coupled distillation column process is a physically complicated system in many aspects. Specifically, the nested interrelationship between system inputs and outputs constitutes one of the significant challenges in system control design. Mostly, such a process is to be decoupled into several input/output pairings (loops, so that a single controller can be assigned for each loop. In the frame of this research, the Brain Emotional Learning Based Intelligent Controller (BELBIC forms the control structure for each decoupled loop. The paper’s main objective is to develop a parameterization technique for decoupling and control schemes, which ensures robust control behavior. In this regard, the novel optimization technique Bacterial Swarm Optimization (BSO is utilized for the minimization of summation of the integral time-weighted squared errors (ITSEs for all control loops. This optimization technique constitutes a hybrid between two techniques, which are the Particle Swarm and Bacterial Foraging algorithms. According to the simulation results, this hybridized technique ensures low mathematical burdens and high decoupling and control accuracy. Moreover, the behavior analysis of the proposed BELBIC shows a remarkable improvement in the time domain behavior and robustness over the conventional PID controller.

  3. Experimental investigation on thermal performance of a closed loop pulsating heat pipe (CLPHP) using methanol and distilled water at different filling ratios

    Science.gov (United States)

    Rahman, Md. Lutfor; Swarna, Anindita Dhar; Ahmed, Syed Nasif Uddin; Perven, Sanjida; Ali, Mohammad

    2016-07-01

    Pulsating Heat Pipes, the new two-phase heat transfer devices, with no counter current flow between liquid and vapor have become a modern topic for research in the field of thermal management. This paper focuses on the performance of methanol and distilled water as working fluid in a closed loop pulsating heat pipe (CLPHP). This performances are compared in terms of thermal resistance, heat transfer co-efficient, and evaporator and condenser wall temperature with variable heat inputs. Methanol and Distilled water are selected for their lower surface tension, dynamic viscosity and sensible heat. A closed loop PHP made of copper with 2mm ID and 2.5mm OD having total 8 loops are supplied with power input varied from 10W to 60W. During the experiment the PHP is kept vertical, while the filling ratio (FR) is increased gradually from 40% to 70% with 10% increment. The optimum filling ratio for a minimum thermal resistance is found to be 60% and 40% for distilled water and methanol respectively and methanol is found to be the better working fluid compared to distilled water in terms of its lower thermal resistance and higher heat transfer coefficient.

  4. Transient simulation of a solar heating system for a small-scale ethanol-water distillation plant: Thermal, environmental and economic performance

    International Nuclear Information System (INIS)

    Vargas-Bautista, Juan Pablo; García-Cuéllar, Alejandro Javier; Pérez-García, Santiago L.; Rivera-Solorio, Carlos I.

    2017-01-01

    Highlights: • Thermal simulation of a small solar ethanol distillation plant is performed. • The optimum collector area is obtained for two different thermal collectors types. • Higher solar fraction was found for parabolic trough collectors. • Economic analysis is performed for different scenarios to evaluate feasibility. - Abstract: The thermal, environmental and economic performance of a small-scale ethanol distillation system, where solar energy is used as primary energy source, was studied. Two different concentrations of ethanol at the feed stream (5 wt.% and 10 wt.%) were analysed to obtain a distillate product of 95 wt.% ethanol (hydrous ethanol). Evacuated tube solar collectors (ETC) and parabolic trough collectors (PTC) were considered for the solar heating system. A case of study for a specific geographical place (Monterrey, México) was developed herein to evaluate the solar ethanol distillation system; the results can be extended to other locations, weather conditions and operational parameters. The thermal results from the simulation showed that through an adequate selection of the solar collector area and an appropriate sizing of the different equipment of the solar distillation system, PTC represents a better option where energy savings of 80% and 71% can be achieved for 5 wt.% and 10 wt.% ethanol at the feed stream, respectively. However, the economic feasibility of the solar distillation system is achieved using ETC for a price of hydrous ethanol of 1.75 USD/L and a feed stream of 10 wt.% ethanol, reaching an internal rate of return (IRR) of 18.8% and payback period of 5.2 years. As an important technical result, selected ETC presented advantages over PTC where an average distillate product of 3.6 and 3.4 ml at 95 wt.% ethanol can be obtained per unit of solar energy (kW h) captured per area (m 2 ) of solar collector using 5 wt.% and 10 wt.% ethanol at the feed stream, respectively (36% more than PTC). The reduction of greenhouse gases

  5. electrical-thermal coupling of induction machine for improved

    African Journals Online (AJOL)

    user

    This paper summarizes the electrical-thermal coupling of induction machine for improved thermal performance. The interaction of its electrical and mechanical parts leads to an increase in temperature which if not properly monitored may lead to breakdown of the machine. The paper therefore, set out to study the effect of ...

  6. Thermal coupling system analysis of a nuclear desalination plant

    International Nuclear Information System (INIS)

    Adak, A.K.; Srivastava, V.K.; Tewari, P.K.

    2010-01-01

    When a nuclear reactor is used to supply steam for desalination plant, the method of coupling has a significant technical and economic impact. The exact method of coupling depends upon the type of reactor and type of desalination plant. As a part of Nuclear Desalination Demonstration Project (NDDP), BARC has successfully commissioned a 4500 m 3 /day MSF desalination plant coupled to Madras Atomic Power Station (MAPS) at Kalpakkam. Desalination plant coupled to nuclear power plant of Pressurized Heavy Water Reactor (PHWR) type is a good example of dual-purpose nuclear desalination plant. This paper presents the thermal coupling system analysis of this plant along with technical and safety aspects. (author)

  7. Coupling of the Models of Human Physiology and Thermal Comfort

    Science.gov (United States)

    Pokorny, J.; Jicha, M.

    2013-04-01

    A coupled model of human physiology and thermal comfort was developed in Dymola/Modelica. A coupling combines a modified Tanabe model of human physiology and thermal comfort model developed by Zhang. The Coupled model allows predicting the thermal sensation and comfort of both local and overall from local boundary conditions representing ambient and personal factors. The aim of this study was to compare prediction of the Coupled model with the Fiala model prediction and experimental data. Validation data were taken from the literature, mainly from the validation manual of software Theseus-FE [1]. In the paper validation of the model for very light physical activities (1 met) indoor environment with temperatures from 12 °C up to 48 °C is presented. The Coupled model predicts mean skin temperature for cold, neutral and warm environment well. However prediction of core temperature in cold environment is inaccurate and very affected by ambient temperature. Evaluation of thermal comfort in warm environment is supplemented by skin wettedness prediction. The Coupled model is designed for non-uniform and transient environmental conditions; it is also suitable simulation of thermal comfort in vehicles cabins. The usage of the model is limited for very light physical activities up to 1.2 met only.

  8. Coupling of the Models of Human Physiology and Thermal Comfort

    Directory of Open Access Journals (Sweden)

    Jicha M.

    2013-04-01

    Full Text Available A coupled model of human physiology and thermal comfort was developed in Dymola/Modelica. A coupling combines a modified Tanabe model of human physiology and thermal comfort model developed by Zhang. The Coupled model allows predicting the thermal sensation and comfort of both local and overall from local boundary conditions representing ambient and personal factors. The aim of this study was to compare prediction of the Coupled model with the Fiala model prediction and experimental data. Validation data were taken from the literature, mainly from the validation manual of software Theseus–FE [1]. In the paper validation of the model for very light physical activities (1 met indoor environment with temperatures from 12 °C up to 48 °C is presented. The Coupled model predicts mean skin temperature for cold, neutral and warm environment well. However prediction of core temperature in cold environment is inaccurate and very affected by ambient temperature. Evaluation of thermal comfort in warm environment is supplemented by skin wettedness prediction. The Coupled model is designed for non-uniform and transient environmental conditions; it is also suitable simulation of thermal comfort in vehicles cabins. The usage of the model is limited for very light physical activities up to 1.2 met only.

  9. Thermally-driven Coupled THM Processes in Shales

    Science.gov (United States)

    Rutqvist, J.

    2017-12-01

    Temperature changes can trigger strongly coupled thermal-hydrological-mechanical (THM) processes in shales that are important to a number of subsurface energy applications, including geologic nuclear waste disposal and hydrocarbon extraction. These coupled processes include (1) direct pore-volume couplings, by thermal expansion of trapped pore-fluid that triggers instantaneous two-way couplings between pore fluid pressure and mechanical deformation, and (2) indirect couplings in terms of property changes, such as changes in mechanical stiffness, strength, and permeability. Direct pore-volume couplings have been studied in situ during borehole heating experiments in shale (or clay stone) formations at Mont Terri and Bure underground research laboratories in Switzerland and France. Typically, the temperature changes are accompanied with a rapid increase in pore pressure followed by a slower decrease towards initial (pre-heating) pore pressure. Coupled THM modeling of these heater tests shows that the pore pressure increases because the thermal expansion coefficient of the fluid is much higher than that of the porous clay stone. Such thermal pressurization induces fluid flow away from the pressurized area towards areas of lower pressure. The rate of pressure increase and magnitude of peak pressure depends on the rate of heating, pore-compressibility, and permeability of the shale. Modeling as well as laboratory experiments have shown that if the pore pressure increase is sufficiently large it could lead to fracturing of the shale or shear slip along pre-existing bedding planes. Another set of data and observations have been collected associated with studies related to concentrated heating and cooling of oil-shales and shale-gas formations. Heating may be used to enhance production from tight oil-shale, whereas thermal stimulation has been attempted for enhanced shale-gas extraction. Laboratory experiments on shale have shown that strength and elastic deformation

  10. Ethyl Acetate Synthesis by Coupling of Fixed-bed Reactor and Reactive Distillation Column—Process Integration Aspects

    Czech Academy of Sciences Publication Activity Database

    Smejkal, Q.; Kolena, J.; Hanika, Jiří

    2009-01-01

    Roč. 154, 1-3 (2009), s. 236-240 ISSN 1385-8947. [International Conference on Chemical Reactors - CHEMREACTOR -18 /18./. Malta, 23.09.2008-03.10.2008] Institutional research plan: CEZ:AV0Z40720504 Keywords : ethyl acetate * esterification * reactive distillation Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 2.816, year: 2009

  11. D-brane disformal coupling and thermal dark matter

    Science.gov (United States)

    Dutta, Bhaskar; Jimenez, Esteban; Zavala, Ivonne

    2017-11-01

    Conformal and disformal couplings between a scalar field and matter occur naturally in general scalar-tensor theories. In D-brane models of cosmology and particle physics, these couplings originate from the D-brane action describing the dynamics of its transverse (the scalar) and longitudinal (matter) fluctuations, which are thus coupled. During the post-inflationary regime and before the onset of big bang nucleosynthesis (BBN), these couplings can modify the expansion rate felt by matter, changing the predictions for the thermal relic abundance of dark matter particles and thus the annihilation rate required to satisfy the dark matter content today. We study the D-brane-like conformal and disformal couplings effect on the expansion rate of the Universe prior to BBN and its impact on the dark matter relic abundance and annihilation rate. For a purely disformal coupling, the expansion rate is always enhanced with respect to the standard one. This gives rise to larger cross sections when compared to the standard thermal prediction for a range of dark matter masses, which will be probed by future experiments. In a D-brane-like scenario, the scale at which the expansion rate enhancement occurs depends on the string coupling and the string scale.

  12. Identification of trace volatile compounds in freshly distilled Calvados and Cognac using preparative separations coupled with gas chromatography-mass spectrometry.

    Science.gov (United States)

    Ledauphin, Jérôme; Saint-Clair, Jean-François; Lablanquie, Odile; Guichard, Hugues; Founier, Nicole; Guichard, Elisabeth; Barillier, Daniel

    2004-08-11

    Gas chromatography coupled with mass spectrometry (GC-MS) using both electron impact and chemical ionization detection modes led to the determination of the volatile composition of two samples of freshly distilled Cognac and two samples of freshly distilled Calvados. A total of 169 volatile compounds were directly identified in dichloromethane extracts obtained by liquid-liquid extraction. Trace compounds present in both spirits were characterized with the help of preparative separations. In a first step, groups of compounds were separated by preparative GC, and the fractions were analyzed on a polar stationary phase by GC-MS. In a second step, silica gel fractionation was used to separate them by polarity. In this study, 331 compounds, of which 162 can be considered as trace compounds, were characterized in both freshly distilled Cognac and Calvados. Of these, 39 are common to both spirits; 30 are specific to Cognac with numerous hexenyl esters and norisoprenoidic derivatives, whereas 93 are specific to Calvados with compounds such as unsaturated alcohols, phenolic derivatives, and unsaturated aldehydes.

  13. VHTR core modeling: coupling between neutronic and thermal-hydraulics

    International Nuclear Information System (INIS)

    Limaiem, I.; Damian, F.; Raepsaet, X.; Studer, E.

    2005-01-01

    Following the present interest in the next generation nuclear power plan (NGNP), Cea is deploying special effort to develop new models and qualify its research tools for this next generation reactors core. In this framework, the Very High Temperature Reactor concept (VHTR) has an increasing place in the actual research program. In such type of core, a strong interaction exists between neutronic and thermal-hydraulics. Consequently, the global core modelling requires accounting for the temperature feedback in the neutronic models. The purpose of this paper is to present the new neutronic and thermal-hydraulics coupling model dedicated to the High Temperature Reactors (HTR). The coupling model integrates a new version of the neutronic scheme calculation developed in collaboration between Cea and Framatome-ANP. The neutronic calculations are performed using a specific calculation processes based on the APOLLO2 transport code and CRONOS2 diffusion code which are part of the French reactor physics code system SAPHYR. The thermal-hydraulics model is characterised by an equivalent porous media and 1-D fluid/3-D thermal model implemented in the CAST3M/ARCTURUS code. The porous media approach involves the definition of both homogenous and heterogeneous models to ensure a correct temperature feedback. This study highlights the sensitivity of the coupling system's parameters (radial/axial meshing and data exchange strategy between neutronic and thermal-hydraulics code). The parameters sensitivity study leads to the definition of an optimal coupling system specification for the VHTR. Besides, this work presents the first physical analysis of the VHTR core in steady-state condition. The analysis gives information about the 3-D power peaking and the temperature coefficient. Indeed, it covers different core configurations with different helium distribution in the core bypass. (authors)

  14. Coupled fast-thermal system at the 'RB' nuclear reactor

    International Nuclear Information System (INIS)

    Pesic, M.

    1987-01-01

    The results of the analyses of the possibility of the coupled fast-thermal system (CFTS) design at the 'RB' nuclear reactor are shown. As the proof of the theoretical analyses the first stage CFTS-1 has been designed, realized, and tested. The excellent agreement between the results of the CFTS-1 studies and the theoretical predictions opens a straight way to the second, the final stage - realization of the designed CFST at the 'RB' nuclear reactor. (author)

  15. Coupled fast-thermal system at the 'RB' nuclear reactor

    International Nuclear Information System (INIS)

    Pesic, M.

    1987-04-01

    The results of the analyses of the possibility of the coupled fast-thermal system (CFTS) design at the 'RB' nuclear reactor are shown. As the proof of the theoretical analyses the first stage CFTS-1 has been designed, realized, and tested. The excellent agreement between the results of the CFTS-1 studies and the theoretical predictions opens a straight way to the second, the final stage - realization of the designed CFST at the 'RB' nuclear reactor. (author)

  16. Gauge coupling unification and nonequilibrium thermal dark matter.

    Science.gov (United States)

    Mambrini, Yann; Olive, Keith A; Quevillon, Jérémie; Zaldívar, Bryan

    2013-06-14

    We study a new mechanism for the production of dark matter in the Universe which does not rely on thermal equilibrium. Dark matter is populated from the thermal bath subsequent to inflationary reheating via a massive mediator whose mass is above the reheating scale T(RH). To this end, we consider models with an extra U(1) gauge symmetry broken at some intermediate scale (M(int) ≃ 10(10)-10(12) GeV). We show that not only does the model allow for gauge coupling unification (at a higher scale associated with grand unification) but it can provide a dark matter candidate which is a standard model singlet but charged under the extra U(1). The intermediate scale gauge boson(s) which are predicted in several E6/SO(10) constructions can be a natural mediator between dark matter and the thermal bath. We show that the dark matter abundance, while never having achieved thermal equilibrium, is fixed shortly after the reheating epoch by the relation T(RH)(3)/M(int)(4). As a consequence, we show that the unification of gauge couplings which determines M(int) also fixes the reheating temperature, which can be as high as T(RH) ≃ 10(11) GeV.

  17. A Lumped Thermal Model Including Thermal Coupling and Thermal Boundary Conditions for High Power IGBT Modules

    DEFF Research Database (Denmark)

    Bahman, Amir Sajjad; Ma, Ke; Blaabjerg, Frede

    2018-01-01

    Detailed thermal dynamics of high power IGBT modules are important information for the reliability analysis and thermal design of power electronic systems. However, the existing thermal models have their limits to correctly predict these complicated thermal behavior in the IGBTs: The typically used...... thermal model based on one-dimensional RC lumps have limits to provide temperature distributions inside the device, moreover some variable factors in the real-field applications like the cooling and heating conditions of the converter cannot be adapted. On the other hand, the more advanced three......-dimensional thermal models based on Finite Element Method (FEM) need massive computations, which make the long-term thermal dynamics difficult to calculate. In this paper, a new lumped three-dimensional thermal model is proposed, which can be easily characterized from FEM simulations and can acquire the critical...

  18. Coupled Thermal Field of the Rotor of Liquid Floated Gyroscope

    Directory of Open Access Journals (Sweden)

    Wang Zhengjun

    2015-01-01

    Full Text Available Inertial navigation devices include star sensor, GPS, and gyroscope. Optical fiber and laser gyroscopes provide high accuracy, and their manufacturing costs are also high. Magnetic suspension rotor gyroscope improves the accuracy and reduces the production cost of the device because of the influence of thermodynamic coupling. Therefore, the precision of the gyroscope is reduced and drift rate is increased. In this study, the rotor of liquid floated gyroscope, particularly the dished rotor gyroscope, was placed under a thermal field, which improved the measurement accuracy of the gyroscope. A dynamic theory of the rotor of liquid floated gyroscope was proposed, and the thermal field of the rotor was simulated. The maximum stress was in x, 1.4; y, 8.43; min 97.23; and max 154.34. This stress occurred at the border of the dished rotor at a high-speed rotation. The secondary flow reached 5549 r/min, and the generated heat increased. Meanwhile, the high-speed rotation of the rotor was volatile, and the dished rotor movement was unstable. Thus, nanomaterials must be added to reduce the thermal coupling fluctuations in the dished rotor and improve the accuracy of the measurement error and drift rate.

  19. Geometric nonlinear formulation for thermal-rigid-flexible coupling system

    Science.gov (United States)

    Fan, Wei; Liu, Jin-Yang

    2013-10-01

    This paper develops geometric nonlinear hybrid formulation for flexible multibody system with large deformation considering thermal effect. Different from the conventional formulation, the heat flux is the function of the rotational angle and the elastic deformation, therefore, the coupling among the temperature, the large overall motion and the elastic deformation should be taken into account. Firstly, based on nonlinear strain-displacement relationship, variational dynamic equations and heat conduction equations for a flexible beam are derived by using virtual work approach, and then, Lagrange dynamics equations and heat conduction equations of the first kind of the flexible multibody system are obtained by leading into the vectors of Lagrange multiplier associated with kinematic and temperature constraint equations. This formulation is used to simulate the thermal included hub-beam system. Comparison of the response between the coupled system and the uncoupled system has revealed the thermal chattering phenomenon. Then, the key parameters for stability, including the moment of inertia of the central body, the incident angle, the damping ratio and the response time ratio, are analyzed. This formulation is also used to simulate a three-link system applied with heat flux. Comparison of the results obtained by the proposed formulation with those obtained by the approximate nonlinear model and the linear model shows the significance of considering all the nonlinear terms in the strain in case of large deformation. At last, applicability of the approximate nonlinear model and the linear model are clarified in detail.

  20. Coupling between water chemistry and thermal output at unsaturated repositories

    International Nuclear Information System (INIS)

    Walton, J.; LeMone, D.; Casey, D.

    1995-01-01

    This paper summarizes issues in predicting thermohydrology in the near field of a deep geological repository and the implications for performance assessment. Predicted thermohydrology depends on waste package design, and particularly on backfill materials. The coupling between solute concentrations and thermal gradients leads to a prediction of highly variable water chemistry in the near field which is radically different than the initial, undisturbed water chemistry; however, most analyses to date assume that waste package chemistry is approximately the same as initial pore water chemistry. Several alternative, simplified approaches for performance assessment are discussed

  1. Coupled heat conduction and thermal stress formulation using explicit integration

    International Nuclear Information System (INIS)

    Marchertas, A.H.; Kulak, R.F.

    1982-06-01

    The formulation needed for the conductance of heat by means of explicit integration is presented. The implementation of these expressions into a transient structural code, which is also based on explicit temporal integration, is described. Comparisons of theoretical results with code predictions are given both for one-dimensional and two-dimensional problems. The coupled thermal and structural solution of a concrete crucible, when subjected to a sudden temperature increase, shows the history of cracking. The extent of cracking is compared with experimental data

  2. A Feasibility Study of Ammonia Recovery from Coking Wastewater by Coupled Operation of a Membrane Contactor and Membrane Distillation

    Directory of Open Access Journals (Sweden)

    Po-Hsun Lin

    2018-03-01

    Full Text Available More than 80% of ammonia (NH3 in the steel manufacturing process wastewater is contributed from the coking wastewater, which is usually treated by biological processes. However, the NH3 in the coking wastewater is typically too high for biological treatment due to its inhibitory concentration. Therefore, a two-stage process including a hollow fiber membrane contactor (HFMC and a modified membrane distillation (MD system was developed and applied to reduce and recover NH3 from coking wastewater. The objectives of this paper are to evaluate different membrane materials, receiving solutions, and operation parameters for the system, remove NH3 from the coking wastewater to less than 300 mg N/L, which is amenable to the biological process, and recover ammonia solution for reuse. As a result, the polytetrafluoroethylene (PTFE HFMC using sulfuric acid as a receiving solution can achieve a maximum NH3-N transmembrane flux of 1.67 g N/m2·h at pH of 11.5 and reduce NH3 in the coking wastewater to less than 300 mg N/L. The NH3 in the converted ammonium sulfate ((NH42SO4 was then recovered by the modified MD using ice water as the receiving solution to produce ≥3% of ammonia solution for reuse.

  3. A Feasibility Study of Ammonia Recovery from Coking Wastewater by Coupled Operation of a Membrane Contactor and Membrane Distillation.

    Science.gov (United States)

    Lin, Po-Hsun; Horng, Ren-Yang; Hsu, Shu-Fang; Chen, Shiao-Shing; Ho, Chia-Hua

    2018-03-03

    More than 80% of ammonia (NH₃) in the steel manufacturing process wastewater is contributed from the coking wastewater, which is usually treated by biological processes. However, the NH₃ in the coking wastewater is typically too high for biological treatment due to its inhibitory concentration. Therefore, a two-stage process including a hollow fiber membrane contactor (HFMC) and a modified membrane distillation (MD) system was developed and applied to reduce and recover NH₃ from coking wastewater. The objectives of this paper are to evaluate different membrane materials, receiving solutions, and operation parameters for the system, remove NH₃ from the coking wastewater to less than 300 mg N/L, which is amenable to the biological process, and recover ammonia solution for reuse. As a result, the polytetrafluoroethylene (PTFE) HFMC using sulfuric acid as a receiving solution can achieve a maximum NH₃-N transmembrane flux of 1.67 g N/m²·h at pH of 11.5 and reduce NH₃ in the coking wastewater to less than 300 mg N/L. The NH₃ in the converted ammonium sulfate ((NH₄)₂SO₄) was then recovered by the modified MD using ice water as the receiving solution to produce ≥3% of ammonia solution for reuse.

  4. Design of a thermally integrated bioethanol-fueled solid oxide fuel cell system integrated with a distillation column

    Science.gov (United States)

    Jamsak, W.; Douglas, P. L.; Croiset, E.; Suwanwarangkul, R.; Laosiripojana, N.; Charojrochkul, S.; Assabumrungrat, S.

    Solid oxide fuel cell systems integrated with a distillation column (SOFC-DIS) have been investigated in this study. The MER (maximum energy recovery) network for SOFC-DIS system under the base conditions (C EtOH = 25%, EtOH recovery = 80%, V = 0.7 V, fuel utilization = 80%, T SOFC = 1200 K) yields Q Cmin = 73.4 and Q Hmin = 0 kW. To enhance the performance of SOFC-DIS, utilization of internal useful heat sources from within the system (e.g. condenser duty and hot water from the bottom of the distillation column) and a cathode recirculation have been considered in this study. The utilization of condenser duty for preheating the incoming bioethanol and cathode recirculation for SOFC-DIS system were chosen and implemented to the SOFC-DIS (CondBio-CathRec). Different MER designs were investigated. The obtained MER network of CondBio-CathRec configuration shows the lower minimum cold utility (Q Cmin) of 55.9 kW and total cost index than that of the base case. A heat exchanger loop and utility path were also investigated. It was found that eliminate the high temperature distillate heat exchanger can lower the total cost index. The recommended network is that the hot effluent gas is heat exchanged with the anode heat exchanger, the external reformer, the air heat exchanger, the distillate heat exchanger and the reboiler, respectively. The corresponding performances of this design are 40.8%, 54.3%, 0.221 W cm -2 for overall electrical efficiency, Combine Heat and Power (CHP) efficiency and power density, respectively. The effect of operating conditions on composite curves on the design of heat exchanger network was investigated. The obtained composite curves can be divided into two groups: the threshold case and the pinch case. It was found that the pinch case which T SOFC = 1173 K yields higher total cost index than the CondBio-CathRec at the base conditions. It was also found that the pinch case can become a threshold case by adjusting split fraction or operating at

  5. Volatiles profiling in medicinal licorice roots using steam distillation and solid-phase microextraction (SPME) coupled to chemometrics.

    Science.gov (United States)

    Farag, Mohamed A; Wessjohann, Ludger A

    2012-11-01

    Licorice (Glycyrrhiza glabra L.) is a plant of considerable commercial importance in traditional medicine and for the flavor and sweets industry. Although Glycyrrhiza species are very competitive targets for phytochemical studies, very little is known about the volatiles composition within that genus, although such knowledge can be suspected to be relevant for understanding the olfactory and taste properties. To provide insight into Glycyrrhiza species aroma composition and for its use in food and pharmaceutical industry, volatile constituents from G. glabra, G. inflata, and G. echinata roots were profiled using steam distillation and solid-phase microextraction. Two phenols, thymol and carvacrol, were found exclusively in essential oil and headspace samples of G. glabra, and with highest amounts for samples that originated from Egypt. In G. echinata oil, (2E, 4E)-decadienal (21%) and β-caryophyllene oxide (24%) were found as main constituents, whereas 1α, 10α-epoxyamorpha-4-ene (13%) and β-dihydroionone (8%) predominated G. inflata. Principal component and hierarchical cluster analyses clearly separated G. echinata and G. inflata from G. glabra; with phenolics and aliphatic aldehydes contributing mostly for species segregation. Licorice (Glycyrrhiza glabra) has large economic, nutritional, and medicinal values. The data presented in this article help in licorice quality control analysis to identify G. glabra from its closely allied species. The presence of thymol and carvacrol exclusively in G. glabra suggests that these volatiles could serve as chemotaxonomic markers and also might be considered as potentially relevant for taste. © 2012 Institute of Food Technologists®

  6. A coupled electro-thermal Discontinuous Galerkin method

    Science.gov (United States)

    Homsi, L.; Geuzaine, C.; Noels, L.

    2017-11-01

    This paper presents a Discontinuous Galerkin scheme in order to solve the nonlinear elliptic partial differential equations of coupled electro-thermal problems. In this paper we discuss the fundamental equations for the transport of electricity and heat, in terms of macroscopic variables such as temperature and electric potential. A fully coupled nonlinear weak formulation for electro-thermal problems is developed based on continuum mechanics equations expressed in terms of energetically conjugated pair of fluxes and fields gradients. The weak form can thus be formulated as a Discontinuous Galerkin method. The existence and uniqueness of the weak form solution are proved. The numerical properties of the nonlinear elliptic problems i.e., consistency and stability, are demonstrated under specific conditions, i.e. use of high enough stabilization parameter and at least quadratic polynomial approximations. Moreover the prior error estimates in the H1-norm and in the L2-norm are shown to be optimal in the mesh size with the polynomial approximation degree.

  7. Coupled neutronics - thermal-hydraulics programs for SCWRS

    Energy Technology Data Exchange (ETDEWEB)

    Reiss, T. [Institute of Nuclear Techniques, Budapest University of Technology and Economics, Muegyetem rkp. 9., 1111 Budapest (Hungary)

    2010-07-01

    The Supercritical Water Cooled Reactor (SCWR) was chosen as one of the Generation IV reactors by GIF. At the moment, a number of concepts - thermal as well as fast ones - exist. The reference parameters for a thermal SCWR have been taken from the European High Performance Light Water Reactor (HPLWR). Since the pressure is higher than the critical pressure (22.1 MPa) there is no change in the phase of the water in the core. On the other hand, due to the significant changes in the physical properties of water at supercritical pressure, the system is susceptible to local temperature, density and power oscillations. This inclination is increased by the pseudo-critical transformation of the water used as coolant. Thus, for modelling a system of this type coupled neutronics - thermal-hydraulics programs are required. Such a program system has been developed with the following main features: great modularity which allows for easy modifications, thus several SCWR concepts can be studied; detailed assembly calculations (with MCNP) and full-core analysis (with SCALE) are supported; the differential equations of xenon poisoning are implemented to study xenon oscillations. The program system was used to examine the assembly of the HPLWR, to design the assembly and the core of the Simplified Supercritical Water Cooled Reactor (SSCWR) and to model xenon oscillations in SCWRs. (authors)

  8. Performance analysis on a new multi-effect distillation combined with an open absorption heat transformer driven by waste heat

    International Nuclear Information System (INIS)

    Zhang, Xiaodong; Hu, Dapeng; Li, Zhiyi

    2014-01-01

    In this paper, a new water distillation system, which consists of either a single- or multi-effect distiller combined with an open absorption heat transformer (OAHT), has been proposed. The new integrated system can be used for distilling waste water with high amounts of SiO 2 from heavy oil production, and the resultant distilled water can be supplied to steam boilers to produce high quality steam which in turn is injected into oil reservoirs to assist with heavy oil recovery. The thermodynamic cycle performances for these new integrated distillation systems were simulated based on the thermodynamic properties of the aqueous solution of LiBr as well as the mass and energy balance of the system. The results indicate that combined with OAHT, the waste heat at 70 °C can be elevated to 125 °C and thereby produce steam at 120 °C in the absorber, which is able to drive a four-effect distiller to produce distilled water. For a single-effect and four-effect distiller, the coefficients of performance (COP) are approximately 1.02 while the performance ratios are 2.19 and 5.72, respectively. Therefore, the four-effect distillation system combined with an OAHT is more thermally effective and is an ideal option to process the waste water in oilfields. -- Highlights: • A new absorption vapor compression distillation was proposed in present research. • An open absorption heat transformer has a coupled thermally evaporator and absorber. • Distillation of waste water with high content of SiO 2 from heavy oil production. • The waste heat of 70 °C can be elevated up to 125 °C and generate steam of 120 °C. • The waste heat is able to drive four-effect distillation to produce distilled water

  9. Coupling Geothermal Heat Pumps with Underground Seasonal Thermal Energy Storage (EW-201135)

    Science.gov (United States)

    2017-03-01

    FINAL REPORT Coupling Geothermal Heat Pumps with Underground Seasonal Thermal Energy Storage ESTCP Project EW-201135 MARCH 2017...TITLE AND SUBTITLE Coupling Geothermal Heat Pumps with Underground Seasonal Thermal Energy Storage 5a. CONTRACT NUMBER 5b...LIST OF FIGURES Page Figure 2.1. Borehole Thermal Energy Storage (BTES) Overview ............................................................ 8

  10. Coupled electrochemical thermal modelling of a novel Li-ion battery pack thermal management system

    International Nuclear Information System (INIS)

    Basu, Suman; Hariharan, Krishnan S.; Kolake, Subramanya Mayya; Song, Taewon; Sohn, Dong Kee; Yeo, Taejung

    2016-01-01

    Highlights: • Three-dimensional electrochemical thermal model of Li-ion battery pack using computational fluid dynamics (CFD). • Novel pack design for compact liquid cooling based thermal management system. • Simple temperature estimation algorithm for the cells in the pack using the results from the model. • Sensitivity of the thermal performance to contact resistance has been investigated. - Abstract: Thermal management system is of critical importance for a Li-ion battery pack, as high performance and long battery pack life can be simultaneously achieved when operated within a narrow range of temperature around the room temperature. An efficient thermal management system is required to keep the battery temperature in this range, despite widely varying operating conditions. A novel liquid coolant based thermal management system, for 18,650 battery pack has been introduced herein. This system is designed to be compact and economical without compromising safety. A coupled three-dimensional (3D) electrochemical thermal model is constructed for the proposed Li-ion battery pack. The model is used to evaluate the effects of different operating conditions like coolant flow-rate and discharge current on the pack temperature. Contact resistance is found to have the strongest impact on the thermal performance of the pack. From the numerical solution, a simple and novel temperature correlation of predicting the temperatures of all the individual cells given the temperature measurement of one cell is devised and validated with experimental results. Such coefficients have great potential of reducing the sensor requirement and complexity in a large Li-ion battery pack, typical of an electric vehicle.

  11. Theory of mode coupling in spin torque oscillators coupled to a thermal bath of magnons

    Science.gov (United States)

    Zhou, Yan; Zhang, Shulei; Li, Dong; Heinonen, Olle

    Recently, numerous experimental investigations have shown that the dynamics of a single spin torque oscillator (STO) exhibits complex behavior stemming from interactions between two or more modes of the oscillator. Examples are the observed mode-hopping and mode coexistence. There has been some initial work indicating how the theory for a single-mode (macro-spin) spin torque oscillator should be generalized to include several modes and the interactions between them. In this work, we rigorously derive such a theory starting with the generalized Landau-Lifshitz-Gilbert equation in the presence of the current-driven spin transfer torques. We will first show, in general, that how a linear mode coupling would arise through the coupling of the system to a thermal bath of magnons, which implies that the manifold of orbits and fixed points may shift with temperature. We then apply our theory to two experimentally interesting systems: 1) a STO patterned into nano-pillar with circular or elliptical cross-sections and 2) a nano-contact STO. For both cases, we found that in order to get mode coupling, it would be necessary to have either a finite in-plane component of the external field or an Oersted field. We will also discuss the temperature dependence of the linear mode coupling. Y. Zhou acknowledges the support by the Seed Funding Program for Basic Research from the University of Hong Kong, and University Grants Committee of Hong Kong (Contract No. AoE/P-04/08).

  12. Near-term feasibility of nuclear reactors for seawater desalting. Coupling of standard condensing nuclear power stations to low-grade heat multieffect distillation plants

    International Nuclear Information System (INIS)

    Adar, J.; Manor, S.; Schaal, M.

    1977-01-01

    The paper describes the horizontal aluminium tube, multieffect distillation process developed by Israel Desalination Engineering Ltd., which is very suitable for the use of low-grade heat from standard condensing nuclear turbines operating at increased back-pressure. A special flash-chamber constitutes a positive barrier against any possible contamination being carried over by the steam exhausted from the turbine to the desalination plant. Flow sheets, heat and mass balances have been prepared for two standard sizes of NSSS and turbines, two back-pressures, and corresponding desalination plants. Only standard equipment is being used in the steam and electricity-producing plant. The desalination plant consists of 6 to 12 parallel double lines, each of them similar to a large prototype now being designed and which will be coupled to an old fossil-fuel power station. Total energy requirements of the desalination plant represent only 19 to 50% of the total water cost as against 75% for a single-purpose plant. Costs are based on actual bids for the power plant and actual estimates for the desalination prototype. The operation is designed to be flexible so that the power plant can be operated either in conjunction with the desalination plant, or as a single-purpose plant. (author)

  13. Thermal DBI action for the D3-brane at weak and strong coupling

    DEFF Research Database (Denmark)

    Grignani, Gianluca; Harmark, Troels; Marini, Andrea

    2014-01-01

    We study the effective action for finite-temperature D3-branes with an electromagnetic field at weak and strong coupling. We call this action the thermal DBI action. Comparing at low temperature the leading T4 correction for the thermal DBI action at weak and strong coupling we find that the 3/4 ...

  14. Thermalization and confinement in strongly coupled gauge theories

    Directory of Open Access Journals (Sweden)

    Ishii Takaaki

    2016-01-01

    Full Text Available Quantum field theories of strongly interacting matter sometimes have a useful holographic description in terms of the variables of a gravitational theory in higher dimensions. This duality maps time dependent physics in the gauge theory to time dependent solutions of the Einstein equations in the gravity theory. In order to better understand the process by which “real world” theories such as QCD behave out of thermodynamic equilibrium, we study time dependent perturbations to states in a model of a confining, strongly coupled gauge theory via holography. Operationally, this involves solving a set of non-linear Einstein equations supplemented with specific time dependent boundary conditions. The resulting solutions allow one to comment on the timescale by which the perturbed states thermalize, as well as to quantify the properties of the final state as a function of the perturbation parameters. We comment on the influence of the dual gauge theory’s confinement scale on these results, as well as the appearance of a previously anticipated universal scaling regime in the “abrupt quench” limit.

  15. Holographic thermalization in [Formula: see text] super Yang-Mills theory at finite coupling.

    Science.gov (United States)

    Stricker, Stefan A

    We investigate the behavior of energy-momentum tensor correlators in holographic [Formula: see text] super Yang-Mills plasma, taking finite coupling corrections into account. In the thermal limit we determine the flow of quasinormal modes as a function of the 't Hooft coupling. Then we use a specific model of holographic thermalization to study the deviation of the spectral densities from their thermal limit in an out-of-equilibrium situation. The main focus lies on the thermalization pattern with which the plasma constituents approach their thermal distribution as the coupling constant decreases from the infinite coupling limit. All obtained results point towards the weakening of the usual top-down thermalization pattern.

  16. Spatially resolved thermal desorption/ionization coupled with mass spectrometry

    Science.gov (United States)

    Jesse, Stephen; Van Berkel, Gary J; Ovchinnikova, Olga S

    2013-02-26

    A system and method for sub-micron analysis of a chemical composition of a specimen are described. The method includes providing a specimen for evaluation and a thermal desorption probe, thermally desorbing an analyte from a target site of said specimen using the thermally active tip to form a gaseous analyte, ionizing the gaseous analyte to form an ionized analyte, and analyzing a chemical composition of the ionized analyte. The thermally desorbing step can include heating said thermally active tip to above 200.degree. C., and positioning the target site and the thermally active tip such that the heating step forms the gaseous analyte. The thermal desorption probe can include a thermally active tip extending from a cantilever body and an apex of the thermally active tip can have a radius of 250 nm or less.

  17. Rapid analysis of Fructus forsythiae essential oil by ionic liquids-assisted microwave distillation coupled with headspace single-drop microextraction followed by gas chromatography–mass spectrometry

    International Nuclear Information System (INIS)

    Jiao, Jiao; Ma, Dan-Hui; Gai, Qing-Yan; Wang, Wei; Luo, Meng; Fu, Yu-Jie; Ma, Wei

    2013-01-01

    Graphical abstract: -- Highlights: •A new ILAMD-HS-SDME method is developed for the microextraction of essential oil. •ILs used as destruction agent of plant cell walls and microwave absorption medium. •Parameters affecting the extraction efficiency are optimized by Box–Behnken design. •Procedure benefits: similar constituents, shorter duration and smaller sample amount. •ILAMD-HS-SDME followed by GC–MS is a promising technique in analytical fields. -- Abstract: A rapid, green and effective miniaturized sample preparation and analytical technique, i.e. ionic liquids-assisted microwave distillation coupled with headspace single-drop microextraction (ILAMD-HS-SDME) followed by gas chromatography–mass spectrometry (GC–MS) was developed for the analysis of essential oil (EO) in Fructus forsythiae. In this work, ionic liquids (ILs) were not only used as the absorption medium of microwave irradiation but also as the destruction agent of plant cell walls. 1-Ethyl-3-methylimidazolium acetate ([C 2 mim]OAc) was chosen as the optimal ILs. Moreover, n-heptadecane (2.0 μL) was selected as the appropriate suspended solvent for the extraction and concentration of EO. Extraction conditions of the proposed method were optimized using the relative peak area of EO constituents as the index, and the optimal operational parameters were obtained as follows: irradiation power (300 W), sample mass (0.7 g), mass ratio of ILs to sample (2.4), temperature (78 °C) and time (3.4 min). In comparison to previous reports, the proposed method was faster and required smaller sample amount but could equally monitor all EO constituents with no significant differences

  18. Determination of nonylphenol isomers in landfill leachate and municipal wastewater using steam distillation extraction coupled with comprehensive two-dimensional gas chromatography/time-of-flight mass spectrometry.

    Science.gov (United States)

    Zhang, Caixiang; Eganhouse, Robert P; Pontolillo, James; Cozzarelli, Isabelle M; Wang, Yanxin

    2012-03-23

    4-Nonylphenols (4-NPs) are known endocrine disruptors and by-products of the microbial degradation of nonylphenol polyethoxylate surfactants. One of the challenges to understanding the toxic effects of nonylphenols is the large number of isomers that may exist in environmental samples. In order to attribute toxic effects to specific compounds, a method is needed for the separation and quantitation of individual nonylphenol isomers. The pre-concentration methods of solvent sublimation, solid-phase extraction or liquid-liquid extraction prior to chromatographic analysis can be problematic because of co-extraction of thousands of compounds typically found in complex matrices such as municipal wastewater or landfill leachate. In the present study, steam distillation extraction (SDE) was found to be an effective pre-concentration method for extraction of 4-NPs from leachate and wastewater, and comprehensive two-dimensional gas chromatography (GC×GC) coupled with fast mass spectral data acquisition by time-of-flight mass spectrometry (ToFMS) enhanced the resolution and identification of 4-NP isomers. Concentrations of eight 4-NP isomers were determined in leachate from landfill cells of different age and wastewater influent and effluent samples. 4-NP isomers were about 3 times more abundant in leachate from the younger cell than the older one, whereas concentrations in wastewater effluent were either below detection limits or <1% of influent concentrations. 4-NP isomer distribution patterns were found to have been altered following release to the environment. This is believed to reflect isomer-specific degradation and accumulation of 4-NPs in the aquatic environment. Copyright © 2012 Elsevier B.V. All rights reserved.

  19. Rapid analysis of Fructus forsythiae essential oil by ionic liquids-assisted microwave distillation coupled with headspace single-drop microextraction followed by gas chromatography–mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Jiao, Jiao [State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Harbin 150040 (China); Ma, Dan-Hui [College of Life Sciences, Northeast Forestry University, Harbin 150040 (China); Gai, Qing-Yan; Wang, Wei; Luo, Meng [State Engineering Laboratory of Bio-Resource Eco-Utilization, Northeast Forestry University, Harbin 150040 (China); Fu, Yu-Jie, E-mail: yujie_fu2002@yahoo.com [State Engineering Laboratory of Bio-Resource Eco-Utilization, Northeast Forestry University, Harbin 150040 (China); Ma, Wei, E-mail: mawei@hljucm.net [State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Harbin 150040 (China); School of Pharmaceutical, Heilongjiang University of Chinese Medicine, Harbin 150040 (China)

    2013-12-04

    Graphical abstract: -- Highlights: •A new ILAMD-HS-SDME method is developed for the microextraction of essential oil. •ILs used as destruction agent of plant cell walls and microwave absorption medium. •Parameters affecting the extraction efficiency are optimized by Box–Behnken design. •Procedure benefits: similar constituents, shorter duration and smaller sample amount. •ILAMD-HS-SDME followed by GC–MS is a promising technique in analytical fields. -- Abstract: A rapid, green and effective miniaturized sample preparation and analytical technique, i.e. ionic liquids-assisted microwave distillation coupled with headspace single-drop microextraction (ILAMD-HS-SDME) followed by gas chromatography–mass spectrometry (GC–MS) was developed for the analysis of essential oil (EO) in Fructus forsythiae. In this work, ionic liquids (ILs) were not only used as the absorption medium of microwave irradiation but also as the destruction agent of plant cell walls. 1-Ethyl-3-methylimidazolium acetate ([C{sub 2}mim]OAc) was chosen as the optimal ILs. Moreover, n-heptadecane (2.0 μL) was selected as the appropriate suspended solvent for the extraction and concentration of EO. Extraction conditions of the proposed method were optimized using the relative peak area of EO constituents as the index, and the optimal operational parameters were obtained as follows: irradiation power (300 W), sample mass (0.7 g), mass ratio of ILs to sample (2.4), temperature (78 °C) and time (3.4 min). In comparison to previous reports, the proposed method was faster and required smaller sample amount but could equally monitor all EO constituents with no significant differences.

  20. Determination of nonylphenol isomers in landfill leachate and municipal wastewater using steam distillation extraction coupled with comprehensive two-dimensional gas chromatography/time-of-flight mass spectrometry

    Science.gov (United States)

    Zhang, Caixiang; Eganhouse, Robert P.; Pontolillo, James; Cozzarelli, Isabelle M.; Wang, Yanxin

    2012-01-01

    4-Nonylphenols (4-NPs) are known endocrine disruptors and by-products of the microbial degradation of nonylphenol polyethoxylate surfactants. One of the challenges to understanding the toxic effects of nonylphenols is the large number of isomers that may exist in environmental samples. In order to attribute toxic effects to specific compounds, a method is needed for the separation and quantitation of individual nonylphenol isomers. The pre-concentration methods of solvent sublimation, solid-phase extraction or liquid–liquid extraction prior to chromatographic analysis can be problematic because of co-extraction of thousands of compounds typically found in complex matrices such as municipal wastewater or landfill leachate. In the present study, steam distillation extraction (SDE) was found to be an effective pre-concentration method for extraction of 4-NPs from leachate and wastewater, and comprehensive two-dimensional gas chromatography (GC × GC) coupled with fast mass spectral data acquisition by time-of-flight mass spectrometry (ToFMS) enhanced the resolution and identification of 4-NP isomers. Concentrations of eight 4-NP isomers were determined in leachate from landfill cells of different age and wastewater influent and effluent samples. 4-NP isomers were about 3 times more abundant in leachate from the younger cell than the older one, whereas concentrations in wastewater effluent were either below detection limits or <1% of influent concentrations. 4-NP isomer distribution patterns were found to have been altered following release to the environment. This is believed to reflect isomer-specific degradation and accumulation of 4-NPs in the aquatic environment.

  1. Coupling Geothermal Heat Pumps (GHP) With Underground Seasonal Thermal Energy Storage (USTES)

    Science.gov (United States)

    2017-03-21

    TECHNICAL GUIDANCE Coupling Geothermal Heat Pumps (GHP) With Underground Seasonal Thermal Energy Storage (USTES) ESTCP Project EW-201135 MARCH...Geothermal Heat Pumps with Underground Seasonal Thermal Energy Storage 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6...Geothermal Heat Pumps, thermal , energy storage Page Intentionally Left Blank i TECHNICAL & ENVIRONMENTAL

  2. Thermal tides and Martian dust storms: Direct evidence for coupling

    International Nuclear Information System (INIS)

    Leovy, C.B.; Zurek, R.W.

    1979-01-01

    Observations of surface pressure oscillations at the Viking 1 and Viking 2 lander sites on Mars indicate that the thermally driven global atmospheric tides were closely coupled to the dust content of the Martian atmosphere, especially during northern fall and winter, when two successive global dust storms occurred. The onset of each of these global storms was marked by substantial, nearly simultaneous increases in the dust opacity and in the range of the daily surface pressure variation observed at both lander sites. Although both the diurnal and semidiurnal tidal surface pressure components were amplified at Lander 1 during the onset of a global dust storm, the semidiurnal component was greatly enhanced in relation to the diurnal tide. Semidiurnal wind components were prominent at both lander sites during the height of the global dust storm. We have attempted to interpret these observations using simplified dynamical models. In particular, the semidiurnal wind component can be successfully related to the observed surface pressure variation using a simplified model of a semidiurnally forced Ekman boundary layer. On the other hand, a classical atmospheric tidal model shows that the preferential enhancement of the semidiurnal surface pressure oscillation at Lander 1 can be produced by a tidal heating distribution which places most of the heating (per unit mass) above 10-km altitude. Furthermore, when a dust storm expands to global scale, it does so rather quickly, and the total atmospheric heating at the peak of the dust storm can represent more than 50% of the available insolation. The Viking observations suggest that a number of mechanisms are important for the generation and decay of these episodic Martian global dust storms

  3. Thermal transfer structures coupling electronics card(s) to coolant-cooled structure(s)

    Science.gov (United States)

    David, Milnes P; Graybill, David P; Iyengar, Madhusudan K; Kamath, Vinod; Kochuparambil, Bejoy J; Parida, Pritish R; Schmidt, Roger R

    2014-12-16

    Cooling apparatuses and coolant-cooled electronic systems are provided which include thermal transfer structures configured to engage with a spring force one or more electronics cards with docking of the electronics card(s) within a respective socket(s) of the electronic system. A thermal transfer structure of the cooling apparatus includes a thermal spreader having a first thermal conduction surface, and a thermally conductive spring assembly coupled to the conduction surface of the thermal spreader and positioned and configured to reside between and physically couple a first surface of an electronics card to the first surface of the thermal spreader with docking of the electronics card within a socket of the electronic system. The thermal transfer structure is, in one embodiment, metallurgically bonded to a coolant-cooled structure and facilitates transfer of heat from the electronics card to coolant flowing through the coolant-cooled structure.

  4. Dynamic effects of diabatization in distillation columns

    DEFF Research Database (Denmark)

    Bisgaard, Thomas; Huusom, Jakob Kjøbsted; Abildskov, Jens

    2013-01-01

    The dynamic effects of diabatization in distillation columns are investigated in simulation emphasizing the heat-integrated distillation column (HIDiC). A generic, dynamic, first-principle model has been formulated, which is flexible enough to describe various diabatic distillation configurations....... Dynamic Relative Gain Array and Singular Value Analysis have been applied in a comparative study of a conventional distillation column and a HIDiC. The study showed increased input-output coupling due to diabatization. Feasible SISO control structures for the HIDiC were also found and control...

  5. Dynamic Effects of Diabatization in Distillation Columns

    DEFF Research Database (Denmark)

    Bisgaard, Thomas; Huusom, Jakob Kjøbsted; Abildskov, Jens

    2012-01-01

    The dynamic eects of diabatization in distillation columns are investigated in simulation with primary focus on the heat-integrated distillation column (HIDiC). A generic, dynamic, rst-principle model has been formulated, which is exible to describe various diabatic distillation congurations....... Dynamic Relative Gain Array and Singular Value Analysis have been applied in a comparative study of a conventional distillation column and a HIDiC. The study showed increased input-output coupling due to diabatization. Feasible SISO control structures for the HIDiC were also found. Control...

  6. Cooled electronic system with thermal spreaders coupling electronics cards to cold rails

    Science.gov (United States)

    Chainer, Timothy J; Gaynes, Michael A; Graybill, David P; Iyengar, Madhusudan K; Kamath, Vinod; Kochuparambil, Bejoy J; Schmidt, Roger R; Schultz, Mark D; Simco, Daniel P; Steinke, Mark E

    2013-07-23

    Liquid-cooled electronic systems are provided which include an electronic assembly having an electronics card and a socket with a latch at one end. The latch facilitates securing of the card within the socket or removal of the card from the socket. A liquid-cooled cold rail is disposed at the one end of the socket, and a thermal spreader couples the electronics card to the cold rail. The thermal spreader includes first and second thermal transfer plates coupled to first and second surfaces on opposite sides of the card, and thermally conductive extensions extending from end edges of the plates, which couple the respective transfer plates to the liquid-cooled cold rail. The thermally conductive extensions are disposed to the sides of the latch, and the card is securable within or removable from the socket using the latch without removing the cold rail or the thermal spreader.

  7. Near term feasibility of nuclear reactor for sea-water desalting: coupling of standard condensing nuclear power stations to low grade heat multieffect distillation plants

    International Nuclear Information System (INIS)

    Adar, J.; Manor, S.; Schaal, M.

    1977-01-01

    Commercial nuclear power reactors exist only in standard sizes and designs. No large nuclear back-pressure turbines are available today. Therefore, near term large scale nuclear desalination plants must be tailored to the NSSS sizes and available turbines and not the contrary. Standard condensing nuclear turbines could operate continuously with a back-presure of up to 5-7'' Hg (depending on the supplier). It means that they can exhaust huge amounts of steam at 56 0 C - 64 0 C with a loss of electricity production of 6% - 10% when compared to 2 1/2'' Hg normal condensing pressure. The horizontal aluminium tube multi-effect distillation process developed by ''Israel Desalination Engineering'' Ltd. is very suitable for the use of such low-grade heat: 4 to 9 effects can operate within these temperature ranges. A special flash-chamber constitutes a positive barrier against any possible contamination being carried over by the steam exhausted from the turbine to the desalination plant. Flow sheets, heat and mass balances have been prepared for two standard sizes of NSSS and turbines (1882sup(Mwth) and 2785sup(Mwth)), two ''back-pressures'' (5 1/2'' and 7'' Hg), and corresponding desalination plants. Only standard equipment is being used in the steam and electricity producing plant. The desalination plant consists of 6 to 12 parallel double lines, each of them similar to a large prototype now being designed and which is going to be coupled to an old fossil power station. Water production varies between 50 and 123 sup(us MGD) and water cost between 23 and 36 sup(cents)/M 3 . Total energy requirements of the desalination plant represent only 19 to 50% of the total water cost as against 75% for a single purpose plant. Costs are based on actual bids for the power plant and actual estimates for the desalination prototype. The operation is designed to be flexible so that the power plant can be operated either in conjunction with the desalination plant, or as a single purpose

  8. Coupling diffusion and maximum entropy models to estimate thermal inertia

    Science.gov (United States)

    Thermal inertia is a physical property of soil at the land surface related to water content. We have developed a method for estimating soil thermal inertia using two daily measurements of surface temperature, to capture the diurnal range, and diurnal time series of net radiation and specific humidi...

  9. Coupled Mechanical-Electrochemical-Thermal Analysis of Failure Propagation in Lithium-ion Batteries

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Chao; Santhanagopalan, Shriram; Pesaran, Ahmad

    2016-07-28

    This is a presentation given at the 12th World Congress for Computational Mechanics on coupled mechanical-electrochemical-thermal analysis of failure propagation in lithium-ion batteries for electric vehicles.

  10. Thermal conductivity of magnetic insulators with strong spin-orbit coupling

    Science.gov (United States)

    Stamokostas, Georgios; Lapas, Panteleimon; Fiete, Gregory A.

    We study the influence of spin-orbit coupling on the thermal conductivity of various types of magnetic insulators. In the absence of spin-orbit coupling and orbital-degeneracy, the strong-coupling limit of Hubbard interactions at half filling can often be adequately described in terms of a pure spin Hamiltonian of the Heisenberg form. However, in the presence of spin-orbit coupling the resulting exchange interaction can become highly anisotropic. The effect of the atomic spin-orbit coupling, taken into account through the effect of magnon-phonon interactions and the magnetic order and excitations, on the lattice thermal conductivity of various insulating magnetic systems is studied. We focus on the regime of low temperatures where the dominant source of scattering is two-magnon scattering to one-phonon processes. The thermal current is calculated within the Boltzmann transport theory. We are grateful for financial support from NSF Grant DMR-0955778.

  11. Coupled Aeroheating and Ablative Thermal Response Simulation Tool

    Data.gov (United States)

    National Aeronautics and Space Administration — The thermal protection system (TPS) performance requirements for atmospheric entry vehicles on current and future NASA missions preclude the use of heritage reusable...

  12. Single-electron thermal devices coupled to a mesoscopic gate

    Science.gov (United States)

    Sánchez, Rafael; Thierschmann, Holger; Molenkamp, Laurens W.

    2017-11-01

    We theoretically investigate the propagation of heat currents in a three-terminal quantum dot engine. Electron–electron interactions introduce state-dependent processes which can be resolved by energy-dependent tunneling rates. We identify the relevant transitions which define the operation of the system as a thermal transistor or a thermal diode. In the former case, thermal-induced charge fluctuations in the gate dot modify the thermal currents in the conductor with suppressed heat injection, resulting in huge amplification factors and the possible gating with arbitrarily low energy cost. In the latter case, enhanced correlations of the state-selective tunneling transitions redistribute heat flows giving high rectification coefficients and the unexpected cooling of one conductor terminal by heating the other one. We propose quantum dot arrays as a possible way to achieve the extreme tunneling asymmetries required for the different operations.

  13. PCB-level Electro thermal Coupling Simulation Analysis

    Science.gov (United States)

    Zhou, Runjing; Shao, Xuchen

    2017-10-01

    Power transmission network needs to transmit more current with the increase of the power density. The problem of temperature rise and the reliability is becoming more and more serious. In order to accurately design the power supply system, we must consider the influence of the power supply system including Joule heat, air convection and other factors. Therefore, this paper analyzes the relationship between the electric circuit and the thermal circuit on the basis of the theory of electric circuit and thermal circuit.

  14. General Approach for Composite Thermoelectric Systems with Thermal Coupling: The Case of a Dual Thermoelectric Cooler

    OpenAIRE

    Flores-Niño, Cuautli; Olivares-Robles, Miguel; Loboda, Igor

    2015-01-01

    In this work, we show a general approach for inhomogeneous composite thermoelectric systems, and as an illustrative case, we consider a dual thermoelectric cooler. This composite cooler consists of two thermoelectric modules (TEMs) connected thermally in parallel and electrically in series. Each TEM has different thermoelectric (TE) properties, namely thermal conductance, electrical resistance and the Seebeck coefficient. The system is coupled by thermal conductances to heat reservoirs. The p...

  15. Catalytic distillation structure

    Science.gov (United States)

    Smith, L.A. Jr.

    1984-04-17

    Catalytic distillation structure is described for use in reaction distillation columns, and provides reaction sites and distillation structure consisting of a catalyst component and a resilient component intimately associated therewith. The resilient component has at least about 70 volume % open space and is present with the catalyst component in an amount such that the catalytic distillation structure consists of at least 10 volume % open space. 10 figs.

  16. Investigation of the Fluid-Solid Thermal Coupling for Rolling Bearing under Oil-Air Lubrication

    Directory of Open Access Journals (Sweden)

    Baohong Tong

    2015-02-01

    Full Text Available An excellent oil-air lubrication system helps to improve rolling bearing's working conditions and thus extend its service life span. Flowing and heat dissipating characteristics of oil-air media inside bearing chamber are very complicated due to the fluid-solid thermal coupling. Effects of fluid-solid thermal coupling are neglected in all previous simulation efforts. A numerical model for simulating the flowing inside bearing chamber is developed here based on an analytical fluid-solid thermal coupling method under oil-air lubrication. The effects of the coupling of air-oil flowing and heat dissipating in bearing chamber are predicted. The simulation results indicate that the coupling is influential in the performances of the flowing in rolling bearing under oil-air lubrication. With consideration of the coupling, the turbulence intensity, the turbulent kinetic energy, and the temperature of the rollers are predicted to be lower because part of the heat is carried out by the flow due to the heat transfer. On the contrary, the turbulent dissipation rate gets higher when considering the coupling effects. It is also interesting that the coupling effects have little influence on the flow pressure and the velocity, which is manifested by a little higher predicted value when considering the coupling.

  17. Inserts thermal coupling analysis in hexagonal honeycomb plates used for satellite structural design

    International Nuclear Information System (INIS)

    Boudjemai, A.; Mankour, A.; Salem, H.; Amri, R.; Hocine, R.; Chouchaoui, B.

    2014-01-01

    Mechanical joints and fasteners are essential elements in joining structural components in mechanical systems. The thermal coupling effect between the adjacent inserts depends to a great extent on the thermal properties of the inserts and the clearance. In this paper the Finite-Element Method (FEM) has been employed to study the insert thermal coupling behaviour of the hexagonal honeycomb panel. Fully coupled thermal analysis was conducted in order to predict thermal coupling phenomena caused by the adjacent inserts under extreme thermal loading conditions. Detailed finite elements models for a honeycomb panel are developed in this study including the insert joints. New approach of the adhesive joint is modelled. Thermal simulations showed that the adjacent inserts cause thermal interference and the adjacent inserts are highly sensitive to the effect of high temperatures. The clearance and thermal interference between the adjacent inserts have an important influence on the satellite equipments (such as the electronics box), which can cause the satellite equipments failures. The results of the model presented in this analysis are significant in the preliminary satellites structural dimensioning which present an effective approach of development by reducing the cost and the time of analysis. - Highlights: •In this work we perform thermal analysis of honeycomb plates using finite element method. •Detailed finite elements models for honeycomb panel are developed in this study including the insert joints. •New approach of the adhesive joint is modelled. •The adjacent inserts cause the thermal interference. •We conclude that this work will help in the analysis and the design of complex satellite structures

  18. Thermal Impedance Model of High Power IGBT Modules Considering Heat Coupling Effects

    DEFF Research Database (Denmark)

    Bahman, Amir Sajjad; Ma, Ke; Blaabjerg, Frede

    2014-01-01

    thermal models, only the self-heating effects of the chips are taken into account, while the thermal coupling effects among chips are less considered. This could result in inaccurate temperature estimation, especially in the high power IGBT modules where the chips are allocated closely to each other...... with large amount of heat generated. In this paper, both the self-heating and heat-coupling effects in the of IGBT module are investigated based on Finite Element Method (FEM) simulation, a new thermal impedance model is thereby proposed to better describe the temperature distribution inside IGBT modules....... It is concluded that the heat coupling between IGBT and diode chips strongly influence the temperature distribution inside IGBT module, and this effect can be properly modeled/predicted by the proposed thermal impedance model....

  19. Finite-element analysis of elastic sound-proof coupling thermal state

    Science.gov (United States)

    Tsyss, V. G.; Strokov, I. M.; Sergaeva, M. Yu

    2018-01-01

    The aim is in calculated determining of the elastic rubber-metal element thermal state of soundproof coupling ship shafting under variable influence during loads in time. Thermal coupling calculation is performed with finite element method using NX Simens software with Nastran solver. As a result of studies, the following results were obtained: - a volumetric picture of the temperature distribution over the array of the deformed coupling body is obtained; - time to reach steady-state thermal coupling mode has been determined; - dependences of maximum temperature and time to reach state on the established operation mode on rotation frequency and ambient temperature are determined. The findings prove the conclusion that usage of finite element analysis modern software can significantly speed up problem solving.

  20. Analysis Of Electrical – Thermal Coupling Of Induction Machine ...

    African Journals Online (AJOL)

    The interaction of the Electrical and mechanical parts of Electrical machines gives rise to the heating of the machine's constituent parts. This consequently leads to an increase in temperature which if not properly monitored may lead to the breakdown of the machine. This paper therefore presents the Electrical and thermal ...

  1. Modeling RP-1 Fuel Advanced Distillation Data using Comprehensive Two-Dimensional Gas Chromatography Coupled with Time-of-Flight Mass Spectrometry and Partial Least Squares Analysis

    Science.gov (United States)

    2014-05-07

    for public release; distribution unlimited. Metabolites in Fermenting and Respiring Yeast Cells. Anal Chem 78:2700–2709. doi: 10.1021/ac052106o 447...measures the temperature of the liquid analyzed, and the other thermocouple measures the temperature in the headspace above the liquid being distilled...may potentially occur at high temperatures when analyzing samples containing low-volatility compounds [17]. This feature was achieved by sealing

  2. Self-similar solution for coupled thermal electromagnetic model ...

    African Journals Online (AJOL)

    An investigation into the existence and uniqueness solution of self-similar solution for the coupled Maxwell and Pennes Bio-heat equations have been done. Criteria for existence and uniqueness of self-similar solution are revealed in the consequent theorems. Journal of the Nigerian Association of Mathematical Physics ...

  3. Control properties of hybrid distillation processes for the separation of biobutanol

    DEFF Research Database (Denmark)

    Sánchez-Ramírez, Eduardo; Alcocer-García, Heriberto; Quiroz-Ramírez, Juan José

    2017-01-01

    which is integrated for only two distillation columns instead of three distillation columns, showed good dynamic properties. In addition, thermally coupled sequence A showed better control properties under open-loop analysis. CONCLUSIONS: Using both SVD analysis and closed-loop tests the dynamics...... properties were obtained for several hybrid processes to separate an effluent produced by fermentation. It was possible to control all schemes under both methodologies and it was clear that when the base case became more complex with thermal coupling, section movement or elimination of a column section......BACKGROUND: Butanol produced from fermentation has attracted the interest of research groups because its physicochemical properties show several enhancements over bioethanol. Recent studies have proposed alternative methods to separate and purify biobutanol from a fermentation broth...

  4. Microbubble Distillation for Ethanol-Water Separation

    Directory of Open Access Journals (Sweden)

    Atheer Al-yaqoobi

    2016-01-01

    Full Text Available In the current study, a novel approach for separating ethanol-water mixture by microbubble distillation technology was investigated. Traditional distillation processes require large amounts of energy to raise the liquid to its boiling point to effect removal of volatile components. The concept of microbubble distillation by comparison is to heat the gas phase rather than the liquid phase to achieve separation. The removal of ethanol from the thermally sensitive fermentation broths was taken as a case of study. Consequently the results were then compared with those which could be obtained under equilibrium conditions expected in an “ideal” distillation unit. Microbubble distillation has achieved vapour compositions higher than that which could be obtained under traditional equilibrium conditions. The separation was achieved at liquid temperature significantly less than the boiling point of the mixture. In addition, it was observed that the separation efficiency of the microbubble distillation could be increased by raising the injected air temperature, while the temperature of the liquid mixture increased only moderately. The separation efficiency of microbubble distillation was compared with that of pervaporation for the recovery of bioethanol from the thermally sensitive fermentation broths. The technology could be controlled to give high separation and energy efficiency. This could contribute to improving commercial viability of biofuel production and other coproducts of biorefinery processing.

  5. Quantum thermalization of two coupled two-level systems in eigenstate and bare-state representations

    International Nuclear Information System (INIS)

    Liao Jieqiao; Huang Jinfeng; Kuang Leman

    2011-01-01

    We study analytically the quantum thermalization of two coupled two-level systems (TLSs), which are connected with either two independent heat baths (IHBs) or a common heat bath (CHB). We understand the quantum thermalization in eigenstate and bare-state representations when the coupling between the two TLSs is stronger and weaker than the TLS-bath couplings, respectively. In the IHB case, we find that, when the two IHBs have the same temperatures, the two coupled TLSs in eigenstate representation can be thermalized with the same temperature as those of the IHBs. However, in the case of two IHBs at different temperatures, just when the energy detuning between the two TLSs satisfies a special condition, the two coupled TLSs in eigenstate representation can be thermalized with an immediate temperature between those of the two IHBs. In bare-state representation, we find a counterintuitive phenomenon that, under some conditions, the temperature of the TLS connected with the high-temperature bath is lower than that of the other TLS, which is connected with the low-temperature bath. In the CHB case, the coupled TLSs in eigenstate representation can be thermalized with the same temperature as that of the CHB in nonresonant cases. In bare-state representation, the TLS with a larger energy separation can be thermalized to a thermal equilibrium with a lower temperature. In the resonant case, we find a phenomenon of antithermalization. We also study the steady-state entanglement between the two TLSs in both the IHB and CHB cases.

  6. Neutronic and thermal-hydraulic coupling for 3D reactor core modeling combining MCB and fluent

    Directory of Open Access Journals (Sweden)

    Królikowski Igor P.

    2015-09-01

    Full Text Available Three-dimensional simulations of neutronics and thermal hydraulics of nuclear reactors are a tool used to design nuclear reactors. The coupling of MCB and FLUENT is presented, MCB allows to simulate neutronics, whereas FLUENT is computational fluid dynamics (CFD code. The main purpose of the coupling is to exchange data such as temperature and power profile between both codes. Temperature required as an input parameter for neutronics is significant since cross sections of nuclear reactions depend on temperature. Temperature may be calculated in thermal hydraulics, but this analysis needs as an input the power profile, which is a result from neutronic simulations. Exchange of data between both analyses is required to solve this problem. The coupling is a better solution compared to the assumption of estimated values of the temperatures or the power profiles; therefore the coupled analysis was created. This analysis includes single transient neutronic simulation and several steady-state thermal simulations. The power profile is generated in defined points in time during the neutronic simulation for the thermal analysis to calculate temperature. The coupled simulation gives information about thermal behavior of the reactor, nuclear reactions in the core, and the fuel evolution in time. Results show that there is strong influence of neutronics on thermal hydraulics. This impact is stronger than the impact of thermal hydraulics on neutronics. Influence of the coupling on temperature and neutron multiplication factor is presented. The analysis has been performed for the ELECTRA reactor, which is lead-cooled fast reactor concept, where the coolant fl ow is generated only by natural convection

  7. Lifetime prediction of LED lighting systems considering thermal coupling between LED sources and drivers

    DEFF Research Database (Denmark)

    Alfarog, Azzarn Orner; Qu, Xiaohui; Wang, Huai

    2017-01-01

    The lifetime prediction of LED lighting system is important to guide the designers to fulfill the design specifications and to benchmark the cost-competitiveness of different lighting technologies. Currently, the lifetime of LED system is usually predicted from the source part and the driver part...... separately, and then the thermal design is also optimized independently. In practice, the LED source and driver are usually compacted in a single fixture. The heat dissipated from LED source and driver will be coupled together and affect the heat transfer performance, which may degrade the whole system...... and accelerate the failure. In this paper, a new thermal model concerning the thermal coupling is proposed with Finite Element Method (FEM) simulation for parameter acquirement. The proposed model has a better estimation of the thermal stresses of key components in the LED lamps and therefore an improved...

  8. A fully coupled thermal-mechanical-fluid flow model for nonlinear geologic systems

    Science.gov (United States)

    Hart, R. D.

    1981-02-01

    A single model is presented which describes fully coupled thermal-mechanical-fluid flow behavior of highly nonlinear, dynamic or quasistatic, porous geologic systems. The mathematical formulation for the model utilizes the continuum theory of mixtures to describe the multiphase nature of the system, and incremental linear constitutive theory to describe the path dependency of nonlinear material behavior. The model, incorporated in an explicit finite difference numerical procedure, was implemented in two different computer codes. A special-purpose one-dimensional code, SNEAKY, was written for initial validation of the coupling mechanisms and testing of the coupled model logic. A general purpose commercially available code, STEALTH, developed for modeling dynamic nonlinear thermomechanical processes, was modified to include fluid flow behavior and the coupling constitutive model. The fully explicit approach in the coupled calculation facilitated the inclusion of the coupling mechanisms and complex constitutive behavior.

  9. Ferromagnetic and Antiferromagnetic Coupling of Spin Molecular Interfaces with High Thermal Stability.

    Science.gov (United States)

    Avvisati, Giulia; Cardoso, Claudia; Varsano, Daniele; Ferretti, Andrea; Gargiani, Pierluigi; Betti, Maria Grazia

    2018-03-26

    We report an advanced organic spin-interface architecture with magnetic remanence at room temperature, constituted by metal phthalocyanine molecules magnetically coupled with Co layer(s), mediated by graphene. Fe- and Cu-phthalocyanines assembled on graphene/Co have identical structural configurations, but FePc couples antiferromagnetically with Co up to room temperature, while CuPc couples ferromagnetically with weaker coupling and thermal stability, as deduced by element-selective X-ray magnetic circular dichroic signals. The robust antiferromagnetic coupling is stabilized by a superexchange interaction, driven by the out-of-plane molecular orbitals responsible of the magnetic ground state and electronically decoupled from the underlying metal via the graphene layer, as confirmed by ab initio theoretical predictions. These archetypal spin interfaces can be prototypes to demonstrate how antiferromagnetic and/or ferromagnetic coupling can be optimized by selecting the molecular orbital symmetry.

  10. Multiscale development of a fission gas thermal conductivity model: Coupling atomic, meso and continuum level simulations

    Science.gov (United States)

    Tonks, Michael R.; Millett, Paul C.; Nerikar, Pankaj; Du, Shiyu; Andersson, David; Stanek, Christopher R.; Gaston, Derek; Andrs, David; Williamson, Richard

    2013-09-01

    Fission gas production and evolution significantly impact the fuel performance, causing swelling, a reduction in the thermal conductivity and fission gas release. However, typical empirical models of fuel properties treat each of these effects separately and uncoupled. Here, we couple a fission gas release model to a model of the impact of fission gas on the fuel thermal conductivity. To quantify the specific impact of grain boundary (GB) bubbles on the thermal conductivity, we use atomistic and mesoscale simulations. Atomistic molecular dynamic simulations were employed to determine the GB thermal resistance. These values were then used in mesoscale heat conduction simulations to develop a mechanistic expression for the effective GB thermal resistance of a GB containing gas bubbles, as a function of the percentage of the GB covered by fission gas. The coupled fission gas release and thermal conductivity model was implemented in Idaho National Laboratory's BISON fuel performance code to model the behavior of a 10-pellet LWR fuel rodlet, showing how the fission gas impacts the UO2 thermal conductivity. Furthermore, additional BISON simulations were conducted to demonstrate the impact of average grain size on both the fuel thermal conductivity and the fission gas release.

  11. Multiscale development of a fission gas thermal conductivity model: Coupling atomic, meso and continuum level simulations

    International Nuclear Information System (INIS)

    Tonks, Michael R.; Millett, Paul C.; Nerikar, Pankaj; Du, Shiyu; Andersson, David; Stanek, Christopher R.; Gaston, Derek; Andrs, David; Williamson, Richard

    2013-01-01

    Fission gas production and evolution significantly impact the fuel performance, causing swelling, a reduction in the thermal conductivity and fission gas release. However, typical empirical models of fuel properties treat each of these effects separately and uncoupled. Here, we couple a fission gas release model to a model of the impact of fission gas on the fuel thermal conductivity. To quantify the specific impact of grain boundary (GB) bubbles on the thermal conductivity, we use atomistic and mesoscale simulations. Atomistic molecular dynamic simulations were employed to determine the GB thermal resistance. These values were then used in mesoscale heat conduction simulations to develop a mechanistic expression for the effective GB thermal resistance of a GB containing gas bubbles, as a function of the percentage of the GB covered by fission gas. The coupled fission gas release and thermal conductivity model was implemented in Idaho National Laboratory’s BISON fuel performance code to model the behavior of a 10-pellet LWR fuel rodlet, showing how the fission gas impacts the UO 2 thermal conductivity. Furthermore, additional BISON simulations were conducted to demonstrate the impact of average grain size on both the fuel thermal conductivity and the fission gas release

  12. Fouling in Membrane Distillation, Osmotic Distillation and Osmotic Membrane Distillation

    Directory of Open Access Journals (Sweden)

    Mourad Laqbaqbi

    2017-03-01

    Full Text Available Various membrane separation processes are being used for seawater desalination and treatment of wastewaters in order to deal with the worldwide water shortage problem. Different types of membranes of distinct morphologies, structures and physico-chemical characteristics are employed. Among the considered membrane technologies, membrane distillation (MD, osmotic distillation (OD and osmotic membrane distillation (OMD use porous and hydrophobic membranes for production of distilled water and/or concentration of wastewaters for recovery and recycling of valuable compounds. However, the efficiency of these technologies is hampered by fouling phenomena. This refers to the accumulation of organic/inorganic deposits including biological matter on the membrane surface and/or in the membrane pores. Fouling in MD, OD and OMD differs from that observed in electric and pressure-driven membrane processes such electrodialysis (ED, membrane capacitive deionization (MCD, reverse osmosis (RO, nanofiltration (NF, ultrafiltration (UF, microfiltration (MF, etc. Other than pore blockage, fouling in MD, OD and OMD increases the risk of membrane pores wetting and reduces therefore the quantity and quality of the produced water or the concentration efficiency of the process. This review deals with the observed fouling phenomena in MD, OD and OMD. It highlights different detected fouling types (organic fouling, inorganic fouling and biofouling, fouling characterization techniques as well as various methods of fouling reduction including pretreatment, membrane modification, membrane cleaning and antiscalants application.

  13. Investigation on coupling characteristics of neutronics/thermal-hydraulics of PWR NPP core

    International Nuclear Information System (INIS)

    Zheng Yong; Peng Minjun; Xia Genglei; Liu Xinkai

    2014-01-01

    In this paper, an integrated neutronics/thermal-hydraulic model for the reactor of Qinshan Phase n NPP project was developed, using the RELAP5-HD as core coupled computational code. Based on the coupled model, the steady state calculation and the rod drop transient simulation were performed. The results show that the values obtained from RELAP5-HD calculation agree well with the available measured data, and the calculated accident curves can predict all major parameters trends of the transient with good accuracy. Both steady state and transient calculation results are in accordance with the theoretical analysis from the feedback aspect of coupled reactor neutronics/thermal-hydraulics, this demonstrates that a successful coupled model of Qinshan Phase n NPP core has been developed, and the established model provides a good foundation for further simulation analysis of the nuclear power plant system. (authors)

  14. Steady-state entanglement and thermalization of coupled qubits in two common heat baths

    Science.gov (United States)

    Hu, Li-Zhen; Man, Zhong-Xiao; Xia, Yun-Jie

    2018-03-01

    In this work, we study the steady-state entanglement and thermalization of two coupled qubits embedded in two common baths with different temperatures. The common bath is relevant when the two qubits are difficult to be isolated to only contact with their local baths. With the quantum master equation constructed in the eigenstate representation of the coupled qubits, we have demonstrated the variations of steady-state entanglement with respect to various parameters of the qubits' system in both equilibrium and nonequilibrium cases of the baths. The coupling strength and energy detuning of the qubits as well as the temperature gradient of the baths are found to be beneficial to the enhancement of the entanglement. We note a dark state of the qubits that is free from time-evolution and its initial population can greatly influence the steady-state entanglement. By virtues of effective temperatures, we also study the thermalization of the coupled qubits and their variations with energy detuning.

  15. A generalized interface module for the coupling of spatial kinetics and thermal-hydraulics codes

    International Nuclear Information System (INIS)

    Barber, D.A.; Miller, R.M.; Joo, H.G.; Downar, T.J.; Mousseau, V.A.; Ebert, D.D.

    1999-01-01

    A generalized interface module has been developed for the coupling of any thermal-hydraulics code to any spatial kinetics code. The coupling scheme was designed and implemented with emphasis placed on maximizing flexibility while minimizing modifications to the respective codes. In this design, the thermal-hydraulics, general interface, and spatial kinetics codes function independently and utilize the Parallel Virtual Machine software to manage cross-process communication. Using this interface, the USNRC version of the 3D neutron kinetics code, PARCX, has been coupled to the USNRC system analysis codes RELAP5 and TRAC-M. RELAP5/PARCS assessment results are presented for two NEACRP rod ejection benchmark problems and an NEA/OECD main steam line break benchmark problem. The assessment of TRAC-M/PARCS has only recently been initiated, nonetheless, the capabilities of the coupled code are presented for a typical PWR system/core model

  16. The thermal coupling constant and the gap equation in the λ φ 4D model

    International Nuclear Information System (INIS)

    Ananos, G.N.J.; Malbouisson, A.P.C.; Svaiter, N.F.

    1998-05-01

    By the concurrent use of two different resummation methods, the composite operator formalism and the Dyson-Schwinger equation, we re-examine the behaviour at finite temperature of the O(N)-symmetric λψ 4 model in a generic D-dimensional Euclidean space. In the cases D = 3 and D = 4, an analysis of the thermal behaviour of the renormalized squared mass and coupling constant are done for all temperatures. It results that the thermal renormalized squared mass is positive and increases monotonically with the temperature. The behavior of the thermal coupling constant is quite different in odd or even dimensional space. In D = 3, the thermal coupling constant decreases up to a minimum value different from zero and ten grows up monotonically as the temperature increases. In the case D = 4, it is found that the thermal renormalized coupling constant tends in the high temperature limit to a constant asymptotic value. Also for general D-dimensional Euclidean space, we are able to obtain a formula for the critical temperature of the second order phase transition. This formula agrees with previous known values at D = 3 and D 4. (author)

  17. A computational domain decomposition approach for solving coupled flow-structure-thermal interaction problems

    OpenAIRE

    Eugenio Aulisa; Sandro Manservisi; Padmanabhan Seshaiyer

    2009-01-01

    Solving complex coupled processes involving fluid-structure-thermal interactions is a challenging problem in computational sciences and engineering. Currently there exist numerous public-domain and commercial codes available in the area of Computational Fluid Dynamics (CFD), Computational Structural Dynamics (CSD) and Computational Thermodynamics (CTD). Different groups specializing in modelling individual process such as CSD, CFD, CTD often come together to solve a complex coupled ap...

  18. Regenerative adsorption distillation system

    KAUST Repository

    Ng, Kim Choon

    2013-12-26

    There is provided a regenerative adsorption distillation system comprising a train of distillation effects in fluid communication with each other. The train of distillation effects comprises at least one intermediate effect between the first and last distillation effects of the train, each effect comprising a vessel and a condensing tube for flow of a fluid therein. The system further comprises a pair of adsorption-desorption beds in vapour communication with the last effect and at least one intermediate effect, wherein the beds contain an adsorbent that adsorbs vapour from the last effect and transmits desorbed vapour into at least one of the intermediate effect.

  19. Fully coupled thermal-mechanical-fluid flow model for nonliner geologic systems

    International Nuclear Information System (INIS)

    Hart, R.D.

    1981-01-01

    A single model is presented which describes fully coupled thermal-mechanical-fluid flow behavior of highly nonlinear, dynamic or quasistatic, porous geologic systems. The mathematical formulation for the model utilizes the continuum theory of mixtures to describe the multiphase nature of the system, and incremental linear constitutive theory to describe the path dependency of nonlinear material behavior. The model, incorporated in an explicit finite difference numerical procedure, was implemented in two different computer codes. A special-purpose one-dimensional code, SNEAKY, was written for initial validation of the coupling mechanisms and testing of the coupled model logic. A general purpose commercially available code, STEALTH, developed for modeling dynamic nonlinear thermomechanical processes, was modified to include fluid flow behavior and the coupling constitutive model. The fully explicit approach in the coupled calculation facilitated the inclusion of the coupling mechanisms and complex constitutive behavior. Analytical solutions pertaining to consolidation theory for soils, thermoelasticity for solids, and hydrothermal convection theory provided verification of stress and fluid flow, stress and conductive heat transfer, and heat transfer and fluid flow couplings, respectively, in the coupled model. A limited validation of the adequacy of the coupling constitutive assumptions was also performed by comparison with the physical response from two laboratory tests. Finally, the full potential of the coupled model is illustrated for geotechnical applications in energy-resource related areas. Examples in the areas of nuclear waste isolation and cut-and-fill mining are cited

  20. Design of a Protection Thermal Energy Storage Using Phase Change Material Coupled to a Solar Receiver

    Science.gov (United States)

    Verdier, D.; Falcoz, Q.; Ferrière, A.

    2014-12-01

    Thermal Energy Storage (TES) is the key for a stable electricity production in future Concentrated Solar Power (CSP) plants. This work presents a study on the thermal protection of the central receiver of CSP plant using a tower which is subject to considerable thermal stresses in case of cloudy events. The very high temperatures, 800 °C at design point, impose the use of special materials which are able to resist at high temperature and high mechanical constraints and high level of concentrated solar flux. In this paper we investigate a TES coupling a metallic matrix drilled with tubes of Phase Change Material (PCM) in order to store a large amount of thermal energy and release it in a short time. A numerical model is developed to optimize the arrangement of tubes into the TES. Then a methodology is given, based from the need in terms of thermal capacity, in order to help the choice of the geometry.

  1. Irradiation of diffusion couples U-Mo/Al. Thermal calculation

    International Nuclear Information System (INIS)

    Fortis, Ana M.; Mirandou, Monica; Denis, Alicia C.

    2004-01-01

    The development of new low enrichment fuel elements for research reactors has lead to obtaining a number of compounds and alloys where the decrease in the enrichment is compensated by a higher uranium density in the fuel material. This has been achieved in particular with the uranium silicides dispersed in an aluminum matrix, where uranium densities about 4.8 g/cm 3 have been reached. Among the diverse candidate alloys, those of U-Mo with molybdenum content in the range 6 to 10 w % can yield, upon dispersion, to uranium densities of about 8 g/cm 3 . The first irradiation experiments employing these alloys in fuel plates, either dispersed in Al or monolithic revealed certain phenomena which are worthy of further studies. Failures have been detected apparently due to the formation of reaction products between the fissile material and the aluminum matrix, which exhibit a poor irradiation behavior. An experiment was designed which final purpose is to irradiate diffusion couples U-Mo/Al in the RA-3 reactor and to analyze the interaction zone at the working temperatures of the fuel elements. A simple device was built consisting of two Al 6063 blocks which press the U-Mo sample in between, located in an Al capsule. The ensemble is placed in a tube, which can be filled with different gases and introduced in the reactor. For safety reasons temperature predictions are necessary before performing the experiment. To this end, the COSMOS code was used. As a preliminary step and in order to test to exactness of the numerical estimations, two irradiations were performed in the RA-1 reactor with He and N 2 as transference gases. The agreement between the measured and calculated temperatures was good, particularly in the case of He and, along with the numerical predictions for the RA-3 reactor, provides a reliable basis to proceed with the following steps. (author)

  2. Model of natural ventilation by using a coupled thermal-airflow simulation program

    DEFF Research Database (Denmark)

    Oropeza-Perez, Ivan; Østergaard, Poul Alberg; Remmen, Arne

    2012-01-01

    This article presents a model of natural ventilation of buildings at the stage of design and a consequence of the behaviour of the occupants. An evaluation is made by coupling multizone air modelling and thermal building simulation using a deterministic set of input factors comprising among others...

  3. Statistical properties of the energy exchanged between two heat baths coupled by thermal fluctuations

    DEFF Research Database (Denmark)

    Ciliberto, S.; Imparato, A.; Naert, A.

    2013-01-01

    We study both experimentally and theoretically the statistical properties of the energy exchanged between two electrical conductors, kept at different temperatures by two different heat reservoirs, and coupled by the electrical thermal noise. Such a system is ruled by the same equations as two...

  4. Quantum distillation of bosons

    Science.gov (United States)

    Weiss, David

    2015-05-01

    The non-equilibrium dynamics of many-body quantum systems present a series of challenges for theory and opportunities for cold atom experiments. I will describe an experiment in which a bundle of initially trapped superfluid 1D Bose lattice gases is quenched to an untrapped, flat lattice potential. This simple experimental situation in the intermediate coupling regime (U/J between 4 and 9.6) leads to interesting dynamics. These include the progressive dissolution of a fraction of the doublons, as well as the quantum distillation and long term confinement of singlons out of and within the central, doublon-dominated region. We measure these processes by combining absorption imaging, photoassociation and 3-body loss to separately reconstruct the spatial distributions of the expectation values of singlons, doublons and triplons. The qualitative dynamics is reproduced by a Gutzwiller mean field model and the essence of the experiment can be understood by considering simple spatial pictures of site occupancies. This work was supported by the NSF and the ARO.

  5. Coupled large-eddy simulation of thermal mixing in a T-junction

    International Nuclear Information System (INIS)

    Kloeren, D.; Laurien, E.

    2011-01-01

    Analyzing thermal fatigue due to thermal mixing in T-junctions is part of the safety assessment of nuclear power plants. Results of two large-eddy simulations of mixing flow in a T-junction with coupled and adiabatic boundary condition are presented and compared. The temperature difference is set to 100 K, which leads to strong stratification of the flow. The main and the branch pipe intersect horizontally in this simulation. The flow is characterized by steady wavy pattern of stratification and temperature distribution. The coupled solution approach shows highly reduced temperature fluctuations in the near wall region due to thermal inertia of the wall. A conjugate heat transfer approach is necessary in order to simulate unsteady heat transfer accurately for large inlet temperature differences. (author)

  6. Development of MCATHAS system of coupled neutronics/thermal-hydraulics in supercritical water reactor

    Energy Technology Data Exchange (ETDEWEB)

    An, P.; Yao, D. [Science and Tech. on Reactor System Design Tech. Laboratory, Chengdu (China)

    2011-07-01

    The MCATHAS system of coupled neutronics/Thermal-hydraulics in supercritical water reactor is described, which considers the mutual influence between the obvious axial and radial evolution of material temperature, water density and the relative power distribution. This system can obtain the main neutronics and thermal parameters along with burn-up. MCATHAS system is parallel processing coupling. The MCNP code is used for neutronics analysis with the continuous cross section library at any temperature calculated by interpolation algorithm; The sub-channel code ATHAS is for thermal-hydraulics analysis and the ORIGEN Code for burn-up calculation. We validate the code with the assembly of HPLWR and analyze the assembly SCLWR- H. (author)

  7. Giant negative linear compression positively coupled to massive thermal expansion in a metal-organic framework.

    Science.gov (United States)

    Cai, Weizhao; Katrusiak, Andrzej

    2014-07-04

    Materials with negative linear compressibility are sought for various technological applications. Such effects were reported mainly in framework materials. When heated, they typically contract in the same direction of negative linear compression. Here we show that this common inverse relationship rule does not apply to a three-dimensional metal-organic framework crystal, [Ag(ethylenediamine)]NO3. In this material, the direction of the largest intrinsic negative linear compression yet observed in metal-organic frameworks coincides with the strongest positive thermal expansion. In the perpendicular direction, the large linear negative thermal expansion and the strongest crystal compressibility are collinear. This seemingly irrational positive relationship of temperature and pressure effects is explained and the mechanism of coupling of compressibility with expansivity is presented. The positive coupling between compression and thermal expansion in this material enhances its piezo-mechanical response in adiabatic process, which may be used for designing new artificial composites and ultrasensitive measuring devices.

  8. Transient thermal-mechanical coupling behavior analysis of mechanical seals during start-up operation

    Science.gov (United States)

    Gao, B. C.; Meng, X. K.; Shen, M. X.; Peng, X. D.

    2016-05-01

    A transient thermal-mechanical coupling model for a contacting mechanical seal during start-up has been developed. It takes into consideration the coupling relationship among thermal-mechanical deformation, film thickness, temperature and heat generation. The finite element method and multi-iteration technology are applied to solve the temperature distribution and thermal-mechanical deformation as well as their evolution behavior. Results show that the seal gap transforms from negative coning to positive coning and the contact area of the mechanical seal gradually decreases during start-up. The location of the maximum temperature and maximum contact pressure move from the outer diameter to inside diameter. The heat generation and the friction torque increase sharply at first and then decrease. Meanwhile, the contact force decreases and the fluid film force and leakage rate increase.

  9. Improving Neutron Kinetics and Thermal Hydraulics coupled tools for BEPU calculations

    Energy Technology Data Exchange (ETDEWEB)

    Pericas, R.; Reventós, F.; Batet, Il.

    2015-07-01

    The BEPU methodology is capable of providing a solution in terms of increasing the nuclear power production without compromising the safety margins. This study presents different improvements performed using tools available at UPC in the field of Neutron Kinetics and Thermal Hydraulics coupled systems. The paper describes a comparison between the BEPU methodology and the Conservative Bounding methodology within the framework of the Neutron Kinetics and Thermal Hydraulics coupled systems. To perform such comparison the following tools have been selected: TRACE for thermal-hydraulic system calculations, PARCS for reactor kinetics core simulator code. A Main Steam Line Break (MSLB) in a Pressurized Water Reactor (PWR) is the selected simulated transient to show the improvements performed. (Author)

  10. Catalytic distillation process

    Science.gov (United States)

    Smith, L.A. Jr.

    1982-06-22

    A method is described for conducting chemical reactions and fractionation of the reaction mixture comprising feeding reactants to a distillation column reactor into a feed zone and concurrently contacting the reactants with a fixed bed catalytic packing to concurrently carry out the reaction and fractionate the reaction mixture. For example, a method for preparing methyl tertiary butyl ether in high purity from a mixed feed stream of isobutene and normal butene comprising feeding the mixed feed stream to a distillation column reactor into a feed zone at the lower end of a distillation reaction zone, and methanol into the upper end of said distillation reaction zone, which is packed with a properly supported cationic ion exchange resin, contacting the C[sub 4] feed and methanol with the catalytic distillation packing to react methanol and isobutene, and concurrently fractionating the ether from the column below the catalytic zone and removing normal butene overhead above the catalytic zone.

  11. An approach to validation of coupled CFD and system thermal-hydraulics codes

    International Nuclear Information System (INIS)

    Jeltsov, M.; Cadinu, F.; Villanueva, W.; Karbojian, A.; Koop, K.; Kudinov, P.

    2011-01-01

    This paper discusses the development of approach and experimental facility for the validation of coupled Computational Fluid Dynamics (CFD) and System Thermal Hydraulics (STH) codes. The validation of a coupled code requires experiments which feature two way feedback between the component (CFD sub-domain) and the system (STH sub-domain). We present results of CFD analysis that are used in the development of a flexible design for the TALL-3D experimental facility. The facility consists of a lead-bismuth thermal-hydraulic loop operating in forced and natural circulation regimes with a heated pool-type 3D test section. The goal of the design is to achieve a feedback between mixing and stratification phenomena in the 3D tests section and forced / natural circulation flow conditions in the loop. Finally, we discuss the development of an experimental validation matrix for validation of coupled STH and CFD codes that considers the key physical phenomena of interest. (author)

  12. A fully coupled finite element framework for thermal fracturing simulation in subsurface cold CO2 injection

    Directory of Open Access Journals (Sweden)

    Shunde Yin

    2018-03-01

    Simulation of thermal fracturing during cold CO2 injection involves the coupled processes of heat transfer, mass transport, rock deforming as well as fracture propagation. To model such a complex coupled system, a fully coupled finite element framework for thermal fracturing simulation is presented. This framework is based on the theory of non-isothermal multiphase flow in fracturing porous media. It takes advantage of recent advances in stabilized finite element and extended finite element methods. The stabilized finite element method overcomes the numerical instability encountered when the traditional finite element method is used to solve the convection dominated heat transfer equation, while the extended finite element method overcomes the limitation with traditional finite element method that a model has to be remeshed when a fracture is initiated or propagating and fracturing paths have to be aligned with element boundaries.

  13. A coupled nuclear reactor thermal energy storage system for enhanced load following operation

    International Nuclear Information System (INIS)

    Alameri, Saeed A.; King, Jeffrey C.

    2013-01-01

    Nuclear power plants operate most economically at a constant power level, providing base load electric power. In an energy grid containing a high fraction of renewable power sources, nuclear reactors may be subject to significantly variable power demands. These variable power demands can negatively impact the effective capacity factor of the reactor and result in severe economic penalties. Coupling a nuclear reactor to a large thermal energy storage block will allow the reactor to better respond to variable power demands. In the system described in this paper, a Prismatic core Advanced High Temperature Reactor supplies constant power to a lithium chloride molten salt thermal energy storage block that provides thermal power as needed to a closed Brayton cycle energy conversion system. During normal operation, the thermal energy storage block stores thermal energy during the night for use in the times of peak demand during the day. In this case, the nuclear reactor stays at a constant thermal power level. After a loss of forced circulation, the reactor reaches a shut down state in less than half an hour and the average fuel, graphite and coolant temperatures remain well within the design limits over the duration of the transient, demonstrating the inherent safety of the coupled system. (author)

  14. A flexible coupling scheme for Monte Carlo and thermal-hydraulics codes

    International Nuclear Information System (INIS)

    Hoogenboom, J. Eduard; Ivanov, Aleksandar; Sanchez, Victor; Diop, Cheikh

    2011-01-01

    A coupling scheme between a Monte Carlo code and a thermal-hydraulics code is being developed within the European NURISP project for comprehensive and validated reactor analysis. The scheme is flexible as it allows different Monte Carlo codes and different thermal-hydraulics codes to be used. At present the MCNP and TRIPOLI4 Monte Carlo codes can be used and the FLICA4 and SubChanFlow thermal-hydraulics codes. For all these codes only an original executable is necessary. A Python script drives the iterations between Monte Carlo and thermal-hydraulics calculations. It also calls a conversion program to merge a master input file for the Monte Carlo code with the appropriate temperature and coolant density data from the thermal-hydraulics calculation. Likewise it calls another conversion program to merge a master input file for the thermal-hydraulics code with the power distribution data from the Monte Carlo calculation. Special attention is given to the neutron cross section data for the various required temperatures in the Monte Carlo calculation. Results are shown for an infinite lattice of PWR fuel pin cells and a 3 x 3 fuel BWR pin cell cluster. Various possibilities for further improvement and optimization of the coupling system are discussed. (author)

  15. Thermal stability, thermal expansion and grain-growth in exchange-coupled Fe-Pt-Ag-B bulk nanocomposite magnets

    International Nuclear Information System (INIS)

    Nicula, R.; Crisan, O.; Crisan, A.D.; Mercioniu, I.; Stir, M.; Vasiliu, F.

    2015-01-01

    Highlights: • Formation of the L10 FePt hard-magnetic phase (>90%) directly in the as-cast state. • Specific alternating hard/soft nanostructure is stable to 600 °C without grain growth. • Anisotropic and non-linear thermal expansion effects. • The FePtAgB alloy behaves like a single magnetic phase (full exchange coupling). - Abstract: Rare-earth free (RE-free) exchange coupling nanocomposite magnets are intensively studied nowadays due to their potential use in applications demanding stable high-temperature operation and corrosion resistance. In this respect, the FePt alloy system is one of the most actively addressed potential permanent magnet solutions. In FePt alloys, promising magnetic features arise from the co-existence of hard magnetic L1 0 FePt and soft magnetic L1 2 Fe 3 Pt phases emerged from the same metastable precursor. The present work deals with an in-situ temperature-resolved synchrotron radiation study of the thermal stability, thermal expansion and microstructure evolution in exchange-coupled FePtAgB alloys. The as-cast microstructural state as well as the optimized magnetic behavior are given as reference and correlated to the observed microstructural evolution with temperature. The melt-spun Fe 48 Pt 28 Ag 6 B 18 alloy ribbons were examined in situ by synchrotron X-ray powder diffraction from ambient temperature up to 600 °C. The FePt-Fe 3 Pt exchange-coupled microstructure achieved by rapid solidification is not significantly altered during the high temperature exposure. The thermal expansion of the FePt L1 0 unit cell has been found to be strongly anisotropic, being essentially an in-plane expansion which may be seen as an anisotropic invar effect. For the FePt L1 0 phase, a significant deviation from linear thermal expansion is observed at the Curie temperature T C = 477 °C. This non-linear behavior above T C is tentatively linked to a diffusion/segregation mechanism of Ag. The promising hard magnetic properties as well as the

  16. Thermal stability, thermal expansion and grain-growth in exchange-coupled Fe-Pt-Ag-B bulk nanocomposite magnets

    Energy Technology Data Exchange (ETDEWEB)

    Nicula, R., E-mail: radu.nicula@empa.ch [Empa, Swiss Federal Laboratories for Materials Science and Technology, Advanced Materials Processing, Feuerwerkerstr. 39, CH-3602 Thun (Switzerland); Crisan, O.; Crisan, A.D.; Mercioniu, I. [National Institute for Materials Physics, P.O. Box MG-7, 077125 Bucharest-Magurele (Romania); Stir, M. [University of Berne, Department of Chemistry and Biochemistry, Freiestrasse 3, CH-3012 Berne (Switzerland); Vasiliu, F. [National Institute for Materials Physics, P.O. Box MG-7, 077125 Bucharest-Magurele (Romania)

    2015-02-15

    Highlights: • Formation of the L10 FePt hard-magnetic phase (>90%) directly in the as-cast state. • Specific alternating hard/soft nanostructure is stable to 600 °C without grain growth. • Anisotropic and non-linear thermal expansion effects. • The FePtAgB alloy behaves like a single magnetic phase (full exchange coupling). - Abstract: Rare-earth free (RE-free) exchange coupling nanocomposite magnets are intensively studied nowadays due to their potential use in applications demanding stable high-temperature operation and corrosion resistance. In this respect, the FePt alloy system is one of the most actively addressed potential permanent magnet solutions. In FePt alloys, promising magnetic features arise from the co-existence of hard magnetic L1{sub 0} FePt and soft magnetic L1{sub 2} Fe{sub 3}Pt phases emerged from the same metastable precursor. The present work deals with an in-situ temperature-resolved synchrotron radiation study of the thermal stability, thermal expansion and microstructure evolution in exchange-coupled FePtAgB alloys. The as-cast microstructural state as well as the optimized magnetic behavior are given as reference and correlated to the observed microstructural evolution with temperature. The melt-spun Fe{sub 48}Pt{sub 28}Ag{sub 6}B{sub 18} alloy ribbons were examined in situ by synchrotron X-ray powder diffraction from ambient temperature up to 600 °C. The FePt-Fe{sub 3}Pt exchange-coupled microstructure achieved by rapid solidification is not significantly altered during the high temperature exposure. The thermal expansion of the FePt L1{sub 0} unit cell has been found to be strongly anisotropic, being essentially an in-plane expansion which may be seen as an anisotropic invar effect. For the FePt L1{sub 0} phase, a significant deviation from linear thermal expansion is observed at the Curie temperature T{sub C} = 477 °C. This non-linear behavior above T{sub C} is tentatively linked to a diffusion/segregation mechanism of Ag

  17. Machine-Thermal Coupling Stresses Analysis of the Fin-Type Structural Thermoelectric Generator

    Science.gov (United States)

    Zhang, Zheng; Yue, Hao; Chen, Dongbo; Qin, Delei; Chen, Zijian

    2017-05-01

    The design structure and heat-transfer mechanism of a thermoelectric generator (TEG) determine its body temperature state. Thermal stress and thermal deformation generated by the temperature variation directly affect the stress state of thermoelectric modules (TEMs). Therefore, the rated temperature and pressing force of TEMs are important parameters in TEG design. Here, the relationships between structural of a fin-type TEG (FTEG) and these parameters are studied by modeling and "machine-thermal" coupling simulation. An indirect calculation method is adopted in the coupling simulation. First, numerical heat transfer calculations of a three-dimensional FTEG model are conducted according to an orthogonal simulation table. The influences of structural parameters for heat transfer in the channel and outer fin temperature distribution are analyzed. The optimal structural parameters are obtained and used to simulate temperature field of the outer fins. Second, taking the thermal calculation results as the initial condition, the thermal-solid coupling calculation is adopted. The thermal stresses of outer fin, mechanical force of spring-angle pressing mechanism, and clamping force on a TEM are analyzed. The simulation results show that the heat transfer area of the inner fin and the physical parameters of the metal materials are the keys to determining the FTEG temperature field. The pressing mechanism's mechanical force can be reduced by reducing the outer fin angle. In addition, a corrugated cooling water pipe, which has cooling and spring functionality, is conducive to establishing an adaptable clamping force to avoid the TEMs being crushed by the thermal stresses in the body.

  18. Coupled electro-thermal field in a high current electrolysis cell or liquid metal batteries

    Science.gov (United States)

    Cai, Liwei; Ni, Haiou; Lu, Gui-Min; Yu, Jian-Guo

    2018-01-01

    Coupled electro-thermal field exists widely in chemical batteries and electrolysis industry. In this study, a three-dimensional numerical model, which is based on the finite-element software ANSYS, has been built to simulate the electro-thermal field in a magnesium electrolysis cell. The adjustment of the relative position of the anode and cathode can change the energy consumption of the magnesium electrolysis process significantly. Besides, the current intensity has a nonlinear effect on heat balance, and the effects of heat transfer coefficients, electrolysis and air temperature on the heat balance have been released to maintain the thermal stability in a magnesium electrolysis cell. The relationship between structure as well as process parameters and electro-thermal field has been obtained and the simulation results can provide experience for the scale-up design in liquid metal batteries. PMID:29515848

  19. Thermal neutron imaging through XRQA2 GAFCHROMIC films coupled with a cadmium radiator

    Energy Technology Data Exchange (ETDEWEB)

    Sacco, D. [INFN – LNF, Via E. Fermi n.40, Frascati, 00044 Roma (Italy); INAIL – DIT, Via di Fontana Candida n.1, 00040 Monteporzio Catone (Italy); Bedogni, R., E-mail: roberto.bedogni@lnf.infn.it [INFN – LNF, Via E. Fermi n.40, Frascati, 00044 Roma (Italy); Bortot, D. [Politecnico di Milano, Dipartimento di Energia, Via La Masa 34, 20156 Milano (Italy); INFN – Milano, Via Celoria16, 20133 Milano (Italy); Palomba, M. [ENEA Casaccia, Via Anguillarese, 301, S. Maria di Galeria, 00123 Roma (Italy); Pola, A. [Politecnico di Milano, Dipartimento di Energia, Via La Masa 34, 20156 Milano (Italy); INFN – Milano, Via Celoria16, 20133 Milano (Italy); Introini, M.V.; Lorenzoli, M. [Politecnico di Milano, Dipartimento di Energia, Via La Masa 34, 20156 Milano (Italy); Gentile, A. [INFN – LNF, Via E. Fermi n.40, Frascati, 00044 Roma (Italy); Strigari, L. [Laboratory of Medical Physics, Regina Elena National Cancer Institute, Via E. Chianesi 53, 00144 Roma (Italy); Pressello, C. [Department of Medical Physics, Azienda Ospedaliera San Camillo Forlanini, Circonvallazione Gianicolense 87, 00152 Roma (Italy); Soriani, A. [Laboratory of Medical Physics, Regina Elena National Cancer Institute, Via E. Chianesi 53, 00144 Roma (Italy); Gómez-Ros, J.M. [INFN – LNF, Via E. Fermi n.40, Frascati, 00044 Roma (Italy); CIEMAT, Av. Complutense 40, 28040 Madrid (Spain)

    2015-10-21

    A simple and inexpensive method to perform passive thermal neutron imaging on large areas was developed on the basis of XRQA2 GAFCHROMIC films, commonly employed for quality assurance in radiology. To enhance their thermal neutron response, the sensitive face of film was coupled with a 1 mm thick cadmium radiator, forming a sandwich. By exchanging the order of Cd filter and sensitive film with respect to the incident neutron beam direction, two different configurations (beam-Cd-film and beam-film-Cd) were identified. These configurations were tested at thermal neutrons fluence values in the range 10{sup 9}–10{sup 10} cm{sup −2}, using the ex-core radial thermal neutron column of the ENEA Casaccia – TRIGA reactor. The results are presented in this work.

  20. Coupled electro-thermal field in a high current electrolysis cell or liquid metal batteries.

    Science.gov (United States)

    Sun, Ze; Cai, Liwei; Ni, Haiou; Lu, Gui-Min; Yu, Jian-Guo

    2018-02-01

    Coupled electro-thermal field exists widely in chemical batteries and electrolysis industry. In this study, a three-dimensional numerical model, which is based on the finite-element software ANSYS, has been built to simulate the electro-thermal field in a magnesium electrolysis cell. The adjustment of the relative position of the anode and cathode can change the energy consumption of the magnesium electrolysis process significantly. Besides, the current intensity has a nonlinear effect on heat balance, and the effects of heat transfer coefficients, electrolysis and air temperature on the heat balance have been released to maintain the thermal stability in a magnesium electrolysis cell. The relationship between structure as well as process parameters and electro-thermal field has been obtained and the simulation results can provide experience for the scale-up design in liquid metal batteries.

  1. Advanced Distillation Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Maddalena Fanelli; Ravi Arora; Annalee Tonkovich; Jennifer Marco; Ed Rode

    2010-03-24

    The Advanced Distillation project was concluded on December 31, 2009. This U.S. Department of Energy (DOE) funded project was completed successfully and within budget during a timeline approved by DOE project managers, which included a one year extension to the initial ending date. The subject technology, Microchannel Process Technology (MPT) distillation, was expected to provide both capital and operating cost savings compared to conventional distillation technology. With efforts from Velocys and its project partners, MPT distillation was successfully demonstrated at a laboratory scale and its energy savings potential was calculated. While many objectives established at the beginning of the project were met, the project was only partially successful. At the conclusion, it appears that MPT distillation is not a good fit for the targeted separation of ethane and ethylene in large-scale ethylene production facilities, as greater advantages were seen for smaller scale distillations. Early in the project, work involved flowsheet analyses to discern the economic viability of ethane-ethylene MPT distillation and develop strategies for maximizing its impact on the economics of the process. This study confirmed that through modification to standard operating processes, MPT can enable net energy savings in excess of 20%. This advantage was used by ABB Lumus to determine the potential impact of MPT distillation on the ethane-ethylene market. The study indicated that a substantial market exists if the energy saving could be realized and if installed capital cost of MPT distillation was on par or less than conventional technology. Unfortunately, it was determined that the large number of MPT distillation units needed to perform ethane-ethylene separation for world-scale ethylene facilities, makes the targeted separation a poor fit for the technology in this application at the current state of manufacturing costs. Over the course of the project, distillation experiments were

  2. Electromagnetic-mechanical-thermal fully coupled model for Terfenol-D devices

    Science.gov (United States)

    Huang, Wenmei; Deng, Zhangxian; Dapino, Marcelo J.; Weng, Ling; Wang, Bowen

    2015-05-01

    This paper presents a fully coupled, nonlinear electromagnetic-mechanical-thermal model for Terfenol-D devices which include active magnetostrictive materials and passive components. The model includes two parts: (1) a material-level discrete energy-averaged model (DEAM) to describe the magnetomechanical coupling and thermal effect of Terfenol-D and (2) a system-level finite element model formulated in weak form using Maxwell's equations, Newton's law, and heat transfer equations. The objective is to describe the electromagnetic, mechanical, and thermal dynamics of the device. The system finite element model is constructed in COMSOL Multiphysics, and the nonlinear behavior of Terfenol-D is coupled through lookup tables generated by the DEAM. Preliminary results of the output capacity of a Terfenol-D actuator with respect to ambient temperature are presented in terms of blocked force, free displacement, and output power. The blocked force and free displacement decrease by 8.0% and 29.8%, respectively, for a 12 A (RMS) excitation current, as the temperature increases from 20 °C to 180 °C. One of the key contributions of this study is that it accounts for both the temperature-dependent Terfenol-D properties and the thermal effects of surrounding passive systems.

  3. Thermal coupling and effect of subharmonic synchronization in a system of two VO2 based oscillators

    Science.gov (United States)

    Velichko, Andrey; Belyaev, Maksim; Putrolaynen, Vadim; Perminov, Valentin; Pergament, Alexander

    2018-03-01

    We explore a prototype of an oscillatory neural network (ONN) based on vanadium dioxide switching devices. The model system under study represents two oscillators based on thermally coupled VO2 switches. Numerical simulation shows that the effective action radius RTC of coupling depends both on the total energy released during switching and on the average power. It is experimentally and numerically proved that the temperature change ΔT commences almost synchronously with the released power peak and T-coupling reveals itself up to a frequency of about 10 kHz. For the studied switching structure configuration, the RTC value varies over a wide range from 4 to 45 μm, depending on the external circuit capacitance C and resistance Ri, but the variation of Ri is more promising from the practical viewpoint. In the case of a "weak" coupling, synchronization is accompanied by attraction effect and decrease of the main spectra harmonics width. In the case of a "strong" coupling, the number of effects increases, synchronization can occur on subharmonics resulting in multilevel stable synchronization of two oscillators. An advanced algorithm for synchronization efficiency and subharmonic ratio calculation is proposed. It is shown that of the two oscillators the leading one is that with a higher main frequency, and, in addition, the frequency stabilization effect is observed. Also, in the case of a strong thermal coupling, the limit of the supply current parameters, for which the oscillations exist, expands by ∼10%. The obtained results have a universal character and open up a new kind of coupling in ONNs, namely, T-coupling, which allows for easy transition from 2D to 3D integration. The effect of subharmonic synchronization hold promise for application in classification and pattern recognition.

  4. Predicting Formation Damage in Aquifer Thermal Energy Storage Systems Utilizing a Coupled Hydraulic-Thermal-Chemical Reservoir Model

    Science.gov (United States)

    Müller, Daniel; Regenspurg, Simona; Milsch, Harald; Blöcher, Guido; Kranz, Stefan; Saadat, Ali

    2014-05-01

    In aquifer thermal energy storage (ATES) systems, large amounts of energy can be stored by injecting hot water into deep or intermediate aquifers. In a seasonal production-injection cycle, water is circulated through a system comprising the porous aquifer, a production well, a heat exchanger and an injection well. This process involves large temperature and pressure differences, which shift chemical equilibria and introduce or amplify mechanical processes. Rock-fluid interaction such as dissolution and precipitation or migration and deposition of fine particles will affect the hydraulic properties of the porous medium and may lead to irreversible formation damage. In consequence, these processes determine the long-term performance of the ATES system and need to be predicted to ensure the reliability of the system. However, high temperature and pressure gradients and dynamic feedback cycles pose challenges on predicting the influence of the relevant processes. Within this study, a reservoir model comprising a coupled hydraulic-thermal-chemical simulation was developed based on an ATES demonstration project located in the city of Berlin, Germany. The structural model was created with Petrel, based on data available from seismic cross-sections and wellbores. The reservoir simulation was realized by combining the capabilities of multiple simulation tools. For the reactive transport model, COMSOL Multiphysics (hydraulic-thermal) and PHREEQC (chemical) were combined using the novel interface COMSOL_PHREEQC, developed by Wissmeier & Barry (2011). It provides a MATLAB-based coupling interface between both programs. Compared to using COMSOL's built-in reactive transport simulator, PHREEQC additionally calculates adsorption and reaction kinetics and allows the selection of different activity coefficient models in the database. The presented simulation tool will be able to predict the most important aspects of hydraulic, thermal and chemical transport processes relevant to

  5. Effects of coupled thermal, hydrological and chemical processes on nuclide transport

    International Nuclear Information System (INIS)

    Carnahan, C.L.

    1987-03-01

    Coupled thermal, hydrological and chemical processes can be classified in two categories. One category consists of the ''Onsager'' type of processes driven by gradients of thermodynamic state variables. These processes occur simultaneously with the direct transport processes. In particular, thermal osmosis, chemical osmosis and ultrafiltration may be prominent in semipermeable materials such as clays. The other category consists of processes affected indirectly by magnitudes of thermodynamic state variables. An important example of this category is the effect of temperature on rates of chemical reactions and chemical equilibria. Coupled processes in both categories may affect transport of radionuclides. Although computational models of limited extent have been constructed, there exists no model that accounts for the full set of THC-coupled processes. In the category of Onsager coupled processes, further model development and testing is severely constrained by a deficient data base of phenomenological coefficients. In the second category, the lack of a general description of effects of heterogeneous chemical reactions on permeability of porous media inhibits progress in quantitative modeling of hydrochemically coupled transport processes. Until fundamental data necessary for further model development have been acquired, validation efforts will be limited necessarily to testing of incomplete models of nuclide transport under closely controlled experimental conditions. 34 refs., 2 tabs

  6. Thermal Phase Transitions of Strongly Correlated Bosons with Spin-Orbit Coupling

    Science.gov (United States)

    Hickey, Ciarán; Paramekanti, Arun

    2014-12-01

    Experiments on ultracold atoms have started to explore lattice effects and thermal fluctuations for two-component bosons with spin-orbit coupling (SOC). Motivated by this, we derive and study a t J model for lattice bosons with equal Rashba-Dresselhaus SOC and strong Hubbard repulsion in a uniform Zeeman magnetic field. Using the Gutzwiller ansatz, we find strongly correlated ground states with stripe superfluid (SF) order. We formulate a finite temperature generalization of the Gutzwiller method, and show that thermal fluctuations in the doped Mott insulator drive a two-step melting of the stripe SF, revealing a wide regime of a stripe normal fluid.

  7. Model development and calibration for the coupled thermal, hydraulic and mechanical phenomena of the bentonite

    Energy Technology Data Exchange (ETDEWEB)

    Chijimatsu, M.; Borgesson, L.; Fujita, T.; Jussila, P.; Nguyen, S.; Rutqvist, J.; Jing, L.; Hernelind, J.

    2009-02-01

    In Task A of the international DECOVALEX-THMC project, five research teams study the influence of thermal-hydro-mechanical (THM) coupling on the safety of a hypothetical geological repository for spent fuel. In order to improve the analyses, the teams calibrated their bentonite models with results from laboratory experiments, including swelling pressure tests, water uptake tests, thermally gradient tests, and the CEA mock-up THM experiment. This paper describes the mathematical models used by the teams, and compares the results of their calibrations with the experimental data.

  8. Light-water-reactor coupled neutronic and thermal-hydraulic codes

    International Nuclear Information System (INIS)

    Diamond, D.J.

    1982-01-01

    An overview is presented of computer codes that model light water reactor cores with coupled neutronics and thermal-hydraulics. This includes codes for transient analysis and codes for steady state analysis which include fuel depletion and fission product buildup. Applications in nuclear design, reactor operations and safety analysis are given and the major codes in use in the USA are identified. The neutronic and thermal-hydraulic methodologies and other code features are outlined for three steady state codes (PDQ7, NODE-P/B and SIMULATE) and four dynamic codes (BNL-TWIGL, MEKIN, RAMONA-3B, RETRAN-02). Speculation as to future trends with such codes is also presented

  9. Light-water-reactor coupled neutronic and thermal-hydraulic codes

    Energy Technology Data Exchange (ETDEWEB)

    Diamond, D.J.

    1982-01-01

    An overview is presented of computer codes that model light water reactor cores with coupled neutronics and thermal-hydraulics. This includes codes for transient analysis and codes for steady state analysis which include fuel depletion and fission product buildup. Applications in nuclear design, reactor operations and safety analysis are given and the major codes in use in the USA are identified. The neutronic and thermal-hydraulic methodologies and other code features are outlined for three steady state codes (PDQ7, NODE-P/B and SIMULATE) and four dynamic codes (BNL-TWIGL, MEKIN, RAMONA-3B, RETRAN-02). Speculation as to future trends with such codes is also presented.

  10. Coherent oscillation in a linear quantum system coupled to a thermal bath

    International Nuclear Information System (INIS)

    Bell, N.F.; Volkas, R.R.; Sawyer, R.F.

    2000-01-01

    We consider the time development of the density matrix for a system coupled to a thermal bath, in models that go beyond the standard two-level systems through addition of an energy excitation degree of freedom and through the possibility of the replacement of the spin algebra by a more complex algebra. We find conditions under which increasing the coupling to the bath above a certain level decreases the rate of entropy production, and in which the limiting behavior is a dissipationless sinusoidal oscillation that could be interpreted as the synchronization of many modes of the uncoupled system

  11. Implementation and verification of a coupled fire model as a thermal boundary condition within P3/THERMAL

    International Nuclear Information System (INIS)

    Hensinger, D.M.; Gritzo, L.A.; Koski, J.A.

    1996-01-01

    A user-defined boundary condition subroutine has been implemented within P3/THERMAL to represent the heat flux between a noncombusting object and an engulfing fire. The heat flux calculations includes a simple 2D fire model in which energy and radiative heat transport equations are solved to produce estimates of the heat fluxes at the fire-object interface. These estimates reflect radiative coupling between a cold object and the flow of hot combustion gases which has been observed in fire experiments. The model uses a database of experimental pool fire measurements for far field boundary conditions and volumetric heat release rates. Taking into account the coupling between a structure and the fire is an improvement over the σT 4 approximation frequently used as a boundary condition for engineered system response and is the preliminary step in the development of a fire model with a predictive capability. This paper describes the implementation of the fire model as a P3/THERMAL boundary condition and presents the results of a verification calculation carried out using the model

  12. Nuclear-thermal-coupled optimization code for the fusion breeding blanket conceptual design

    Energy Technology Data Exchange (ETDEWEB)

    Li, Jia, E-mail: lijia@ustc.edu.cn [School of Nuclear Science and Technology, University of Science and Technology of China, Hefei 230027, Anhui (China); Jiang, Kecheng; Zhang, Xiaokang [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031, Anhui (China); Nie, Xingchen [School of Nuclear Science and Technology, University of Science and Technology of China, Hefei 230027, Anhui (China); Zhu, Qinjun; Liu, Songlin [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031, Anhui (China)

    2016-12-15

    Highlights: • A nuclear-thermal-coupled predesign code has been developed for optimizing the radial build arrangement of fusion breeding blanket. • Coupling module aims at speeding up the efficiency of design progress by coupling the neutronics calculation code with the thermal-hydraulic analysis code. • Radial build optimization algorithm aims at optimal arrangement of breeding blanket considering one or multiple specified objectives subject to the design criteria such as material temperature limit and available TBR. - Abstract: Fusion breeding blanket as one of the key in-vessel components performs the functions of breeding the tritium, removing the nuclear heat and heat flux from plasma chamber as well as acting as part of shielding system. The radial build design which determines the arrangement of function zones and material properties on the radial direction is the basis of the detailed design of fusion breeding blanket. For facilitating the radial build design, this study aims for developing a pre-design code to optimize the radial build of blanket with considering the performance of nuclear and thermal-hydraulic simultaneously. Two main features of this code are: (1) Coupling of the neutronics analysis with the thermal-hydraulic analysis to speed up the analysis progress; (2) preliminary optimization algorithm using one or multiple specified objectives subject to the design criteria in the form of constrains imposed on design variables and performance parameters within the possible engineering ranges. This pre-design code has been applied to the conceptual design of water-cooled ceramic breeding blanket in project of China fusion engineering testing reactor (CFETR).

  13. Development of coupled neutronics/thermal-hydraulics test case for HPLWR

    Science.gov (United States)

    Pham, P.; Gamtsemlidze, I. D.; Bahdanovich, R. B.; Nikonov, S. P.; Smirnov, A. D.

    2017-01-01

    The High-Performance Light Water Reactor (HPLWR) is the European concept of a supercritical water reactor (SCWR) which is one of the most promising and innovative designs of the Generation IV nuclear reactor concepts. The thermal-hydraulics behavior of supercritical water is significantly different from water at sub-critical pressure because of the difference in the specific heat value. Coupled analysis of HPLWR assembly neutronics and thermal-hydraulics has become important because of the strong influence of the water density on the neutron spectrum and power distribution. Programs MCU (Monte-Carlo Universal) and ATHLET (Analysis of Thermal-hydraulics of Leaks and Transients) were used for better estimation of power and temperature distribution in HPLWR assembly.

  14. Turbulence, chaos and thermal noise in globally coupled Josephson junction arrays

    International Nuclear Information System (INIS)

    Dominguez, D.

    1995-03-01

    We discuss the effects of thermal noise in underdamped Josephson junction series arrays that are globally coupled through a resistive load and driven by an rf current. We study the breakdown of the law of large numbers in the turbulent phase of the Josephson arrays. This corresponds to a saturation of the broad band noise S 0 for a large number N of junctions. We find that this phenomenon is stable against thermal fluctuations below a critical temperature T cl . The behaviour of S 0 vs. T, for large N, shows three different regimes. For 0 cl , S 0 decreases when increasing T, and there is turbulence and the breakdown of the law of large numbers. For T cl c2 , S 0 is constant and the dynamics is dominated by the chaos of the individual junctions. Finally for T > T c2 , S 0 in mainly due to thermal fluctuations, since it increases linearly with T. (author). 23 refs, 6 figs

  15. Three dimensional neutronic/thermal-hydraulic coupled simulation of MSR in transient state condition

    International Nuclear Information System (INIS)

    Zhou, Jianjun; Zhang, Daling; Qiu, Suizheng; Su, Guanghui; Tian, Wenxi; Wu, Yingwei

    2015-01-01

    Highlights: • Developed a three dimensional neutronic/thermal-hydraulic coupled transient analysis code for MSR. • Investigated the neutron distribution and thermal-hydraulic characters of the core under transient condition. • Analyzed three different transient conditions of inlet temperature drop, reactivity jump and pump coastdown. - Abstract: MSR (molten salt reactor) use liquid molten salt as coolant and fuel solvent, which was the only one liquid reactor of six Generation IV reactor types. As a liquid reactor the physical property of reactor was significantly influenced by fuel salt flow and the conventional analysis methods applied in solid fuel reactors are not applicable for this type of reactors. The present work developed a three dimensional neutronic/thermal-hydraulic coupled code investigated the neutronics and thermo-hydraulics characteristics of the core in transient condition based on neutron diffusion theory and numerical heat transfer. The code consists of two group neutron diffusion equations for fast and thermal neutron fluxes and six group balance equations for delayed neutron precursors. The code was separately validated by neutron benchmark and flow and heat transfer benchmark. Three different transient conditions was analyzed with inlet temperature drop, reactivity jump and pump coastdown. The results provide some valuable information in design and research this kind of reactor

  16. Validation and applicability of the 3D core kinetics and thermal hydraulics coupled code SPARKLE

    International Nuclear Information System (INIS)

    Miyata, Manabu; Maruyama, Manabu; Ogawa, Junto; Otake, Yukihiko; Miyake, Shuhei; Tabuse, Shigehiko; Tanaka, Hirohisa

    2009-01-01

    The SPARKLE code is a coupled code system based on three individual codes whose physical models have already been verified and validated. Mitsubishi Heavy Industries (MHI) confirmed the coupling calculation, including data transfer and the total reactor coolant system (RCS) behavior of the SPARKLE code. The confirmation uses the OECD/NEA MSLB benchmark problem, which is based on Three Mile Island Unit 1 (TMI-1) nuclear power plant data. This benchmark problem has been used to verify coupled codes developed and used by many organizations. Objectives of the benchmark program are as follows. Phase 1 is to compare the results of the system transient code using point kinetics. Phase 2 is to compare the results of the coupled three-dimensional (3D) core kinetics code and 3D core thermal-hydraulics (T/H) code, and Phase 3 is to compare the results of the combined coupled system transient code, 3D core kinetics code, and 3D core T/H code as a total validation of the coupled calculation. The calculation results of the SPARKLE code indicate good agreement with other benchmark participants' results. Therefore, the SPARKLE code is validated through these benchmark problems. In anticipation of applying the SPARKLE code to licensing analyses, MHI and Japanese PWR utilities have established a safety analysis method regarding the calculation conditions such as power distributions, reactivity coefficients, and event-specific features. (author)

  17. A computational domain decomposition approach for solving coupled flow-structure-thermal interaction problems

    Directory of Open Access Journals (Sweden)

    Eugenio Aulisa

    2009-04-01

    Full Text Available Solving complex coupled processes involving fluid-structure-thermal interactions is a challenging problem in computational sciences and engineering. Currently there exist numerous public-domain and commercial codes available in the area of Computational Fluid Dynamics (CFD, Computational Structural Dynamics (CSD and Computational Thermodynamics (CTD. Different groups specializing in modelling individual process such as CSD, CFD, CTD often come together to solve a complex coupled application. Direct numerical simulation of the non-linear equations for even the most simplified fluid-structure-thermal interaction (FSTI model depends on the convergence of iterative solvers which in turn rely heavily on the properties of the coupled system. The purpose of this paper is to introduce a flexible multilevel algorithm with finite elements that can be used to study a coupled FSTI. The method relies on decomposing the complex global domain, into several local sub-domains, solving smaller problems over these sub-domains and then gluing back the local solution in an efficient and accurate fashion to yield the global solution. Our numerical results suggest that the proposed solution methodology is robust and reliable.

  18. Thermal behavior and transformation kinetics of titanium dioxide nanocrystallites prepared by coupling agents

    International Nuclear Information System (INIS)

    Chen, W.C.; Wang, Y.T.; Shih, C.J.

    2010-01-01

    Coupling agents have been widely used to retard the sintering of silver paste and minimize co-firing defects due to densification mismatch between silver and dielectrics. The thermal-decomposition and crystallization behavior of the coupling agent is a subject of great concern. To elucidate what is responsible for the oxidation, Ti organometallic compounds were calcined at different temperatures (350, 400, 500, 600 o C) for 2 h and the crystallization behavior was determined by X-ray diffraction (XRD). The activation energy for crystallization of coupling agents was studied by using isothermal methods. According to the quantitative XRD method, the values calculated by the Johnson-Mehi-Avrami equation are 134.9 kJ mol -1 . The growth morphology parameters are 1.061, 0.915, 1.016 respectively. Combining the results of DTA, XRD and TEM, it is found that formation of nanocrystallized titania accompanies the combustion of organometallic compounds.

  19. Thermal behavior and transformation kinetics of titanium dioxide nanocrystallites prepared by coupling agents

    Energy Technology Data Exchange (ETDEWEB)

    Chen, W.C. [School of Dentistry, Kaohsiung Medical University, 100 Shi-Chuan 1st Road, Kaohsiung 80708, Taiwan (China); Wang, Y.T. [Department of Medical Research and Education, Chen Hsin General Hospital, 45 Cheng-Hsin Street, Pai-Tou, Taipei 11220, Taiwan (China); Shih, C.J., E-mail: cjshih@kmu.edu.t [Department of Fragrance and Cosmetics Science, Kaohsiung Medical University, 100 Shi-Chuan1st Road, Kaohsiung 80708, Taiwan (China)

    2010-02-04

    Coupling agents have been widely used to retard the sintering of silver paste and minimize co-firing defects due to densification mismatch between silver and dielectrics. The thermal-decomposition and crystallization behavior of the coupling agent is a subject of great concern. To elucidate what is responsible for the oxidation, Ti organometallic compounds were calcined at different temperatures (350, 400, 500, 600 {sup o}C) for 2 h and the crystallization behavior was determined by X-ray diffraction (XRD). The activation energy for crystallization of coupling agents was studied by using isothermal methods. According to the quantitative XRD method, the values calculated by the Johnson-Mehi-Avrami equation are 134.9 kJ mol{sup -1}. The growth morphology parameters are 1.061, 0.915, 1.016 respectively. Combining the results of DTA, XRD and TEM, it is found that formation of nanocrystallized titania accompanies the combustion of organometallic compounds.

  20. A Pore-Scale Simulation on Thermal-Hydromechanical Coupling Mechanism of Rock

    Directory of Open Access Journals (Sweden)

    Rui Song

    2017-01-01

    Full Text Available Thermal-hydromechanical (THM coupling process is a key issue in geotechnical engineering emphasized by many scholars. Most existing studies are conducted at macroscale or mesoscale. This paper presents a pore-scale THM coupling study of the immiscible two-phase flow in the perfect-plastic rock. Assembled rock matrix and pore space models are reconstructed using micro-CT image. The rock deformation and fluid flow are simulated using ANSYS and CFX software, respectively, in which process the coupled physical parameters will be exchanged by ANSYS multiphysics platform at the end of each iteration. Effects of stress and temperature on the rock porosity, permeability, microstructure, and the displacing mechanism of water flooding process are analyzed and revealed.

  1. Analysis of thermally coupled chemical looping combustion-based power plants with carbon capture

    KAUST Repository

    Iloeje, Chukwunwike

    2015-04-01

    © 2015 Elsevier Ltd. A number of CO2 capture-enabled power generation technologies have been proposed to address the negative environmental impact of CO2 emission. One important barrier to adopting these technologies is the associated energy penalty. Chemical-looping Combustion (CLC) is an oxy-combustion technology that can significantly lower this penalty. It utilizes an oxygen carrier to transfer oxygen from air/oxidizing stream in an oxidation reactor to the fuel in a reduction reactor. Conventional CLC reactor designs employ two separate reactors, with metal/metal oxide particles circulating pneumatically in-between. One of the key limitations of these designs is the entropy generation due to reactor temperature difference, which lowers the cycle efficiency. Zhao et al. (Zhao et al., 2014; Zhao and Ghoniem, 2014) proposed a new CLC rotary reactor design, which overcomes this limitation. This reactor consists of a single rotating wheel with micro-channels designed to maintain thermal equilibrium between the fuel and air sides. This study uses three thermodynamic models of increasing fidelity to demonstrate that the internal thermal coupling in the rotary CLC reactor creates the potential for improved cycle efficiency. A theoretical availability model and an ideal thermodynamic cycle model are used to define the efficiency limits of CLC systems, illustrate the impact of reactor thermal coupling and discuss relevant criteria. An Aspen Plus® model of a regenerative CLC cycle is then used to show that this thermal coupling raises the cycle efficiency by up to 2% points. A parametric study shows that efficiency varies inversely with pressure, with a maximum of 51% at 3bar, 1000C and 60% at 4bar, 1400C. The efficiency increases with CO2 fraction at high pressure ratios but exhibits a slight inverse dependence at low pressure ratios. The parametric study shows that for low purge steam demand, steam generation improves exhaust heat recovery and increases efficiency

  2. Characterization of petroleum distillates by GC-AED (coupling with gas chromatography and atomic emission detection); Caracterisation des distillats petroliers par couplage chromatographie en phase gazeuse et detection par emission atomique

    Energy Technology Data Exchange (ETDEWEB)

    Baco, F.

    1997-05-21

    This thesis describes the characterization of atmospheric petroleum distillates (kerosenes and gas-oils) and vacuum distillates by hyphenated technic of Gas Chromatography and Atomic Emission Detector (GC-AED). A gas chromatographic simulated distillation, which gives the weight % of sample as a function of the petroleum cut temperature, was adapted to the GC-AED to obtain an original information about the elemental composition profile. After generalities, historic of the development of the instrument and the first petroleum applications are described. In the experimental part, analytical conditions used, different technics of characterisation of distillates and the base of samples analyzed are exposed. After a study of the GC-AED`s performances for the target elements (C, H, S, N), a quantitative method for the elemental analysis of distillates was developed and validated at three levels: total elemental analysis, simulated distillation and elemental composition as a function of the distillation profile. Finally, different ways for the applications of the GC-AED in order to characterize the distillates were explored, in particular to classify products and predict some petroleum properties (cetane number, density,...). The more interesting outlook seems to be the prediction of some properties as a function of the distillation profile. (author) 155 refs.

  3. Neutronics - thermal-hydraulics coupling: application to the helium-cooled fast reactor

    International Nuclear Information System (INIS)

    Vaiana, F.

    2009-11-01

    This thesis focuses on the study of interactions between neutron-kinetics and thermal-hydraulics. Neutron-kinetics allow to calculate the power in a nuclear reactor and the temperature evolution of materials where this power is deposited is known thanks to thermal-hydraulics. Moreover, when the temperatures evolve, the densities and cross sections change. These two disciplines are thus coupled. The first part of this work corresponds to the study and development of a method which allows to simulate transients in nuclear reactors and especially with a Monte-Carlo code for neutron-kinetics. An algorithm for the resolution of the neutron transport equation has been established and validated with a benchmark. In thermal-hydraulics, a porous media approach, based on another thesis, is considered. This gives the opportunity to solve the equations on the whole core without unconscionable computation time. Finally, a theoretical study has been performed on the statistical uncertainties which result from the use of a Monte-Carlo code and which spread from the reactivity to the power and from the power to the temperatures. The second part deals with the study of a misplaced control rod withdrawing in a GFR (helium-cooled fast reactor), a fourth generation reactor. Some models allowing to calculate neutron-kinetics and thermal-hydraulics in the core (which contains assemblies built up with fuel plates) were defined. In thermal-hydraulics, a model for the core based on the porous media approach and a fuel plate homogenization model have been set up. A similar homogenization model has been studied for neutron-kinetics. Finally, the control rod withdrawing transient where we can observe the power raising and the stabilisation by thermal feedback has been performed with the Monte-Carlo code Tripoli for neutron-kinetics and the code Trio-U for thermal-hydraulics. (author)

  4. BWR transient analysis using neutronic / thermal hydraulic coupled codes including uncertainty quantification

    International Nuclear Information System (INIS)

    Hartmann, C.; Sanchez, V.; Tietsch, W.; Stieglitz, R.

    2012-01-01

    The KIT is involved in the development and qualification of best estimate methodologies for BWR transient analysis in cooperation with industrial partners. The goal is to establish the most advanced thermal hydraulic system codes coupled with 3D reactor dynamic codes to be able to perform a more realistic evaluation of the BWR behavior under accidental conditions. For this purpose a computational chain based on the lattice code (SCALE6/GenPMAXS), the coupled neutronic/thermal hydraulic code (TRACE/PARCS) as well as a Monte Carlo based uncertainty and sensitivity package (SUSA) has been established and applied to different kind of transients of a Boiling Water Reactor (BWR). This paper will describe the multidimensional models of the plant elaborated for TRACE and PARCS to perform the investigations mentioned before. For the uncertainty quantification of the coupled code TRACE/PARCS and specifically to take into account the influence of the kinetics parameters in such studies, the PARCS code has been extended to facilitate the change of model parameters in such a way that the SUSA package can be used in connection with TRACE/PARCS for the U and S studies. This approach will be presented in detail. The results obtained for a rod drop transient with TRACE/PARCS using the SUSA-methodology showed clearly the importance of some kinetic parameters on the transient progression demonstrating that the coupling of a best-estimate coupled codes with uncertainty and sensitivity tools is very promising and of great importance for the safety assessment of nuclear reactors. (authors)

  5. Design Methodology of a Dual-Halbach Array Linear Actuator with Thermal-Electromagnetic Coupling

    Science.gov (United States)

    Eckert, Paulo Roberto; Flores Filho, Aly Ferreira; Perondi, Eduardo; Ferri, Jeferson; Goltz, Evandro

    2016-01-01

    This paper proposes a design methodology for linear actuators, considering thermal and electromagnetic coupling with geometrical and temperature constraints, that maximizes force density and minimizes force ripple. The method allows defining an actuator for given specifications in a step-by-step way so that requirements are met and the temperature within the device is maintained under or equal to its maximum allowed for continuous operation. According to the proposed method, the electromagnetic and thermal models are built with quasi-static parametric finite element models. The methodology was successfully applied to the design of a linear cylindrical actuator with a dual quasi-Halbach array of permanent magnets and a moving-coil. The actuator can produce an axial force of 120 N and a stroke of 80 mm. The paper also presents a comparative analysis between results obtained considering only an electromagnetic model and the thermal-electromagnetic coupled model. This comparison shows that the final designs for both cases differ significantly, especially regarding its active volume and its electrical and magnetic loading. Although in this paper the methodology was employed to design a specific actuator, its structure can be used to design a wide range of linear devices if the parametric models are adjusted for each particular actuator. PMID:26978370

  6. Design Methodology of a Dual-Halbach Array Linear Actuator with Thermal-Electromagnetic Coupling

    Directory of Open Access Journals (Sweden)

    Paulo Roberto Eckert

    2016-03-01

    Full Text Available This paper proposes a design methodology for linear actuators, considering thermal and electromagnetic coupling with geometrical and temperature constraints, that maximizes force density and minimizes force ripple. The method allows defining an actuator for given specifications in a step-by-step way so that requirements are met and the temperature within the device is maintained under or equal to its maximum allowed for continuous operation. According to the proposed method, the electromagnetic and thermal models are built with quasi-static parametric finite element models. The methodology was successfully applied to the design of a linear cylindrical actuator with a dual quasi-Halbach array of permanent magnets and a moving-coil. The actuator can produce an axial force of 120 N and a stroke of 80 mm. The paper also presents a comparative analysis between results obtained considering only an electromagnetic model and the thermal-electromagnetic coupled model. This comparison shows that the final designs for both cases differ significantly, especially regarding its active volume and its electrical and magnetic loading. Although in this paper the methodology was employed to design a specific actuator, its structure can be used to design a wide range of linear devices if the parametric models are adjusted for each particular actuator.

  7. Design Methodology of a Dual-Halbach Array Linear Actuator with Thermal-Electromagnetic Coupling.

    Science.gov (United States)

    Eckert, Paulo Roberto; Flores Filho, Aly Ferreira; Perondi, Eduardo; Ferri, Jeferson; Goltz, Evandro

    2016-03-11

    This paper proposes a design methodology for linear actuators, considering thermal and electromagnetic coupling with geometrical and temperature constraints, that maximizes force density and minimizes force ripple. The method allows defining an actuator for given specifications in a step-by-step way so that requirements are met and the temperature within the device is maintained under or equal to its maximum allowed for continuous operation. According to the proposed method, the electromagnetic and thermal models are built with quasi-static parametric finite element models. The methodology was successfully applied to the design of a linear cylindrical actuator with a dual quasi-Halbach array of permanent magnets and a moving-coil. The actuator can produce an axial force of 120 N and a stroke of 80 mm. The paper also presents a comparative analysis between results obtained considering only an electromagnetic model and the thermal-electromagnetic coupled model. This comparison shows that the final designs for both cases differ significantly, especially regarding its active volume and its electrical and magnetic loading. Although in this paper the methodology was employed to design a specific actuator, its structure can be used to design a wide range of linear devices if the parametric models are adjusted for each particular actuator.

  8. Enhanced thermal photon and dilepton production in strongly coupled = 4 SYM plasma in strong magnetic field

    Science.gov (United States)

    Mamo, Kiminad A.

    2013-08-01

    We calculate the DC conductivity tensor of strongly coupled = 4 super-Yang-Mills (SYM) plasma in a presence of a strong external magnetic field B ≫ T 2 by using its gravity dual and employing both the RG flow approach and membrane paradigm which give the same results. We find that, since the magnetic field B induces anisotropy in the plasma, different components of the DC conductivity tensor have different magnitudes depending on whether its components are in the direction of the magnetic field B. In particular, we find that a component of the DC conductivity tensor in the direction of the magnetic field B increases linearly with B while the other components (which are not in the direction of the magnetic field B) are independent of it. These results are consistent with the lattice computations of the DC conductivity tensor of the QCD plasma in an external magnetic field B. Using the DC conductivity tensor, we calculate the soft or low-frequency thermal photon and dilepton production rates of the strongly coupled = 4 SYM plasma in the presence of the strong external magnetic field B ≫ T 2. We find that the strong magnetic field B enhances both the thermal photon and dilepton production rates of the strongly coupled = 4 SYM plasma in a qualitative agreement with the experimentally observed enhancements at the heavy-ion collision experiments.

  9. Modeling of thermal coupling in VO2-based oscillatory neural networks

    Science.gov (United States)

    Velichko, Andrey; Belyaev, Maksim; Putrolaynen, Vadim; Perminov, Valentin; Pergament, Alexander

    2018-01-01

    In this study, we have demonstrated the possibility of using the thermal coupling to control the dynamics of operation of coupled VO2 oscillators. Based on the example of a 'switch-microheater' pair, we have explored the synchronization and dissynchronization modes of a single oscillator with respect to an external harmonic heat impact. The features of changes in the spectra are shown, in particular, the effect of the natural frequency attraction to the affecting signal frequency and the self-oscillation noise reduction effects at synchronization. The time constant of the temperature effect for the considered system configuration is in the range 7-140 μs, which allows operation in the oscillation frequency range of up to ∼70 kHz. A model estimate of the minimum temperature sensitivity of the switch is δTswitch ∼ 0.2 K, and the effective action radius RTC of the switch-to-switch thermal coupling is not less than 25 μm. Nevertheless, as the simulation shows, the frequency range can be significantly extended up to the values of 1-30 GHz if using nanometer-scale switches (heaters). article>

  10. Strong coupling of a building thermal model with a controlled electical heater for an hybrid energy simulation

    OpenAIRE

    Gaaloul, Sana; Delinchant, Benoît; Wurtz, Frédéric; Thiers, Stéphane; Peuportier, Bruno

    2011-01-01

    International audience; The context of this study is the coupling of thermal and electrical models in order to efficiently simulate energy consumption in buildings, which requires managing interoperability problems between simulation environments. The coupling is accomplished in MATLAB™ tool between a thermal model of a building envelope using COMFIE software and an electrical heater model. Our purpose is to study and generalize the interoperability between these two domains governed by pheno...

  11. Automotive Underhood Thermal Management Analysis Using 3-D Coupled Thermal-Hydrodynamic Computer Models: Thermal Radiation Modeling

    Energy Technology Data Exchange (ETDEWEB)

    Pannala, S; D' Azevedo, E; Zacharia, T

    2002-02-26

    The goal of the radiation modeling effort was to develop and implement a radiation algorithm that is fast and accurate for the underhood environment. As part of this CRADA, a net-radiation model was chosen to simulate radiative heat transfer in an underhood of a car. The assumptions (diffuse-gray and uniform radiative properties in each element) reduce the problem tremendously and all the view factors for radiation thermal calculations can be calculated once and for all at the beginning of the simulation. The cost for online integration of heat exchanges due to radiation is found to be less than 15% of the baseline CHAD code and thus very manageable. The off-line view factor calculation is constructed to be very modular and has been completely integrated to read CHAD grid files and the output from this code can be read into the latest version of CHAD. Further integration has to be performed to accomplish the same with STAR-CD. The main outcome of this effort is to obtain a highly scalable and portable simulation capability to model view factors for underhood environment (for e.g. a view factor calculation which took 14 hours on a single processor only took 14 minutes on 64 processors). The code has also been validated using a simple test case where analytical solutions are available. This simulation capability gives underhood designers in the automotive companies the ability to account for thermal radiation - which usually is critical in the underhood environment and also turns out to be one of the most computationally expensive components of underhood simulations. This report starts off with the original work plan as elucidated in the proposal in section B. This is followed by Technical work plan to accomplish the goals of the project in section C. In section D, background to the current work is provided with references to the previous efforts this project leverages on. The results are discussed in section 1E. This report ends with conclusions and future scope of

  12. Techno-economic assessment of boiler feed water production by membrane distillation with reuse of thermal waste energy from cooling water

    NARCIS (Netherlands)

    Kuipers, N.J.M.; Leerdam, R.C. van; Medevoort, J. van; Tongeren, W.G.J.M. van; Verhasselt, B.; Verelst, L.; Vermeersch, M.; Corbisier, D.

    2015-01-01

    The European KIC-Climate project Water and Energy for Climate Change (WE4CC) aims at the technical demonstration, business case evaluation and implementation of new value chains for the production of high-quality water using low-grade thermal waste energy from cooling water. A typical large-scale

  13. A Coupled Model of Multiphase Flow, Reactive Biogeochemical Transport, Thermal Transport and Geo-Mechanics.

    Science.gov (United States)

    Tsai, C. H.; Yeh, G. T.

    2015-12-01

    In this investigation, a coupled model of multiphase flow, reactive biogeochemical transport, thermal transport and geo-mechanics in subsurface media is presented. It iteratively solves the mass conservation equation for fluid flow, thermal transport equation for temperature, reactive biogeochemical transport equations for concentration distributions, and solid momentum equation for displacement with successive linearization algorithm. With species-based equations of state, density of a phase in the system is obtained by summing up concentrations of all species. This circumvents the problem of having to use empirical functions. Moreover, reaction rates of all species are incorporated in mass conservation equation for fluid flow. Formation enthalpy of all species is included in the law of energy conservation as a source-sink term. Finite element methods are used to discretize the governing equations. Numerical experiments are presented to examine the accuracy and robustness of the proposed model. The results demonstrate the feasibility and capability of present model in subsurface media.

  14. Coupled thermal model of photovoltaic-thermoelectric hybrid panel for sample cities in Europe

    DEFF Research Database (Denmark)

    Rezaniakolaei, Alireza; Sera, Dezso; Rosendahl, Lasse Aistrup

    2016-01-01

    of the hybrid system under different weather conditions. The model takes into account solar irradiation, wind speed and ambient temperature as well as convective and radiated heat losses from the front and rear surfaces of the panel. The model is developed for three sample cities in Europe with different......In general, modeling of photovoltaic-thermoelectric (PV/TEG) hybrid panels have been mostly simplified and disconnected from the actual ambient conditions and thermal losses from the panel. In this study, a thermally coupled model of PV/TEG panel is established to precisely predict performance...... weather conditions. The results show that radiated heat loss from the front surface and the convective heat loss due to the wind speed are the most critical parameters on performance of the hybrid panel performance. The results also indicate that, with existing thermoelectric materials, the power...

  15. General Approach for Composite Thermoelectric Systems with Thermal Coupling: The Case of a Dual Thermoelectric Cooler

    Directory of Open Access Journals (Sweden)

    Cuautli Yanehowi Flores-Niño

    2015-06-01

    Full Text Available In this work, we show a general approach for inhomogeneous composite thermoelectric systems, and as an illustrative case, we consider a dual thermoelectric cooler. This composite cooler consists of two thermoelectric modules (TEMs connected thermally in parallel and electrically in series. Each TEM has different thermoelectric (TE properties, namely thermal conductance, electrical resistance and the Seebeck coefficient. The system is coupled by thermal conductances to heat reservoirs. The proposed approach consists of derivation of the dimensionless thermoelectric properties for the whole system. Thus, we obtain an equivalent figure of merit whose impact and meaning is discussed. We make use of dimensionless equations to study the impact of the thermal conductance matching on the cooling capacity and the coefficient of the performance of the system. The equivalent thermoelectric properties derived with our formalism include the external conductances and all intrinsic thermoelectric properties of each component of the system. Our proposed approach permits us changing the thermoelectric parameters of the TEMs and the working conditions of the composite system. Furthermore, our analysis shows the effect of the number of thermocouples on the system. These considerations are very useful for the design of thermoelectric composite systems. We reproduce the qualitative behavior of a commercial composite TEM connected electrically in series.

  16. Electrical and thermal transport in the quasiatomic limit of coupled Luttinger liquids

    Science.gov (United States)

    Szasz, Aaron; Ilan, Roni; Moore, Joel E.

    2017-02-01

    We introduce a new model for quasi-one-dimensional materials, motivated by intriguing but not yet well-understood experiments that have shown two-dimensional polymer films to be promising materials for thermoelectric devices. We consider a two-dimensional material consisting of many one-dimensional systems, each treated as a Luttinger liquid, with weak (incoherent) coupling between them. This approximation of strong interactions within each one-dimensional chain and weak coupling between them is the "quasiatomic limit." We find integral expressions for the (interchain) transport coefficients, including the electrical and thermal conductivities and the thermopower, and we extract their power law dependencies on temperature. Luttinger liquid physics is manifested in a violation of the Wiedemann-Franz law; the Lorenz number is larger than the Fermi liquid value by a factor between γ2 and γ4, where γ ≥1 is a measure of the electron-electron interaction strength in the system.

  17. Role of temperature and composition on the thermal-hydro-mechanical coupling of concretes

    International Nuclear Information System (INIS)

    Brue, Flore

    2009-01-01

    The French project of the storage of nuclear wastes, which is managed by the Andra, needs some experimental data on the durability of the concrete. Loadings which are taken into account are the desaturation/re-saturation processes, the heat load and the mechanical evolution. Hence this study focuses on the coupling thermo-hydro-mechanical on concretes of the research program of Andra, made with CEM I and CEM V/A cement type. The water saturation degree and shrinkages of materials, which are subjected to desiccation or re-saturation, are dependent on the imposed thermal and hydrous conditions and on their microstructural characteristics. Moreover the study of the mechanical evolution is gone further at 20 C in function of the water saturation degree. Different short-term tests highlight a hydrous damage, which determine the mechanical behaviour. The long-term study of desiccation creep shows the coupling between the durability, the mechanical evolution and the desiccation. (author)

  18. Uncertainty propagation applied to multi-scale thermal-hydraulics coupled codes. A step towards validation

    Energy Technology Data Exchange (ETDEWEB)

    Geffray, Clotaire Clement

    2017-03-20

    The work presented here constitutes an important step towards the validation of the use of coupled system thermal-hydraulics and computational fluid dynamics codes for the simulation of complex flows in liquid metal cooled pool-type facilities. First, a set of methods suited for uncertainty and sensitivity analysis and validation activities with regards to the specific constraints of the work with coupled and expensive-to-run codes is proposed. Then, these methods are applied to the ATHLET - ANSYS CFX model of the TALL-3D facility. Several transients performed at this latter facility are investigated. The results are presented, discussed and compared to the experimental data. Finally, assessments of the validity of the selected methods and of the quality of the model are offered.

  19. A One-Structure-Based Multieffects Coupled Nanogenerator for Simultaneously Scavenging Thermal, Solar, and Mechanical Energies.

    Science.gov (United States)

    Ji, Yun; Zhang, Kewei; Yang, Ya

    2018-02-01

    Rapid advances in various energy harvesters impose the challenge on integrating them into one device structure with synergetic effects for full use of the available energies from the environment. Here, a multieffect coupled nanogenerator based on ferroelectric barium titanate is reported. It promotes the ability to simultaneously scavenging thermal, solar, and mechanical energies. By integration of a pyroelectric nanogenerator, a photovoltaic cell, and a triboelectric-piezoelectric nanogenerator in one structure with only two electrodes, multieffects interact with each other to alter the electric output, and a complementary power source with peak current of ≈1.5 µA, peak voltage of ≈7 V, and platform voltage of ≈6 V is successfully achieved. Compared with traditional hybridized nanogenerators with stacked architectures, the one-structure-based multieffects coupled nanogenerator is smaller, simpler, and less costly, showing prospective in practical applications and represents a new trend of all-in-one multiple energy scavenging.

  20. Coupling the severe accident code SCDAP with the system thermal hydraulic code MARS

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Young Jin; Chung, Bub Dong [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    2004-07-01

    MARS is a best-estimate system thermal hydraulics code with multi-dimensional modeling capability. One of the aims in MARS code development is to make it a multi-functional code system with the analysis capability to cover the entire accident spectrum. For this purpose, MARS code has been coupled with a number of other specialized codes such as CONTEMPT for containment analysis, and MASTER for 3-dimensional kinetics. And in this study, the SCDAP code has been coupled with MARS to endow the MARS code system with severe accident analysis capability. With the SCDAP, MARS code system now has acquired the capability to simulate such severe accident related phenomena as cladding oxidation, melting and slumping of fuel and reactor structures.

  1. Coupling the severe accident code SCDAP with the system thermal hydraulic code MARS

    International Nuclear Information System (INIS)

    Lee, Young Jin; Chung, Bub Dong

    2004-01-01

    MARS is a best-estimate system thermal hydraulics code with multi-dimensional modeling capability. One of the aims in MARS code development is to make it a multi-functional code system with the analysis capability to cover the entire accident spectrum. For this purpose, MARS code has been coupled with a number of other specialized codes such as CONTEMPT for containment analysis, and MASTER for 3-dimensional kinetics. And in this study, the SCDAP code has been coupled with MARS to endow the MARS code system with severe accident analysis capability. With the SCDAP, MARS code system now has acquired the capability to simulate such severe accident related phenomena as cladding oxidation, melting and slumping of fuel and reactor structures

  2. Thermal vacuum state for the two-coupled-oscillator model at finite temperature: Derivation and application

    International Nuclear Information System (INIS)

    Xu Xue-Xiang; Hu Li-Yun; Guo Qin; Fan Hong-Yi

    2013-01-01

    Following the spirit of thermo field dynamics initiated by Takahashi and Umezawa, we employ the technique of integration within an ordered product of operators to derive the thermal vacuum state (TVS) for the Hamiltonian H of the two-coupled-oscillator model. The ensemble averages of the system are derived conveniently by using the TVS. In addition, the entropy for this system is discussed based on the relation between the generalized Hellmann—Feynman theorem and the entroy variation in the context of the TVS. (general)

  3. Ventilated buildings optimisation by using a coupled thermal-airflow simulation program

    DEFF Research Database (Denmark)

    Oropeza-Perez, Ivan; Østergaard, Poul Alberg; Remmen, Arne

    2011-01-01

    This work shows the optimization of natural ventilation within buildings at the stage of design and behaviour of the occupants. An evaluation is done by coupled multizone air modelling and thermal building simulation by using a deterministic set of input factors comprising among others climate......, local environment, building characteristics, building systems, behaviour of occupants, heat loads. Selected deterministic input factors were varied to generate additional information applied in an optimization loop. With that, it is found that the optimal solution depends to a great deal...

  4. Thermal spectral functions of strongly coupled N = 4 supersymmetric Yang-Mills theory.

    Science.gov (United States)

    Kovtun, Pavel; Starinets, Andrei

    2006-04-07

    We use the gauge-gravity duality conjecture to compute spectral functions of the stress-energy tensor in finite-temperature N = 4 supersymmetric Yang-Mills theory in the limit of large N(c) and large 't Hooft coupling. The spectral functions exhibit peaks characteristic of hydrodynamic modes at small frequency, and oscillations at intermediate frequency. The nonperturbative spectral functions differ qualitatively from those obtained in perturbation theory. The results may prove useful for lattice studies of transport processes in thermal gauge theories.

  5. Coupled 3D neutronics/thermal hydraulics modeling of the SAFARI-1 MTR

    International Nuclear Information System (INIS)

    Rosenkrantz, Adam; Avramova, Maria; Ivanov, Kostadin; Prinsloo, Rian; Botes, Danniëll; Elsakhawy, Khalid

    2014-01-01

    Highlights: • Development of 3D coupled neutronics/thermal–hydraulic model of SAFARI-1. • Verification of 3D steady-state NEM based neutronics model for SAFARI-1. • Verification of 3D COBRA-TF based thermal–hydraulic model of SAFARI-1. • Quantification of the effect of correct modeling of thermal–hydraulic feedback. - Abstract: The purpose of this study was to develop a coupled accurate multi-physics model of the SAFARI-1 Material Testing Reactor (MTR), a facility that is used for both research and the production of medical isotopes. The model was developed as part of the SAFARI-1 benchmarking project as a cooperative effort between the Pennsylvania State University (PSU) and the South African Nuclear Energy Corporation (Necsa). It was created using a multi-physics coupling of state of the art nuclear reactor simulation tools, consisting of a neutronics code and a thermal hydraulics code. The neutronics tool used was the PSU code NEM, and the results from this component were verified using the Necsa neutronics code OSCAR-4, which is utilized for SAFARI-1 core design and fuel management. On average, the multiplication factors of the neutronics models agreed to within 5 pcm and the radial assembly-averaged powers agreed to within 0.2%. The thermal hydraulics tool used was the PSU version of COBRA-TF (CTF) sub-channel code, and the results of this component were verified against another thermal hydraulics code, the RELAP5-3D system code, used at Necsa for thermal–hydraulics analysis of SAFARI-1. Although only assembly-averaged results from RELAP5-3D were available, they fell within the range of values for the corresponding assemblies in the comprehensive CTF solution. This comparison allows for the first time to perform a quantification of steady-state errors for a low-powered MTR with an advanced thermal–hydraulic code such as CTF on a per-channel basis as compared to simpler and coarser-mesh RELAP5-3D modeling. Additionally, a new cross section

  6. Thermal coupling of a high temperature PEM fuel cell with a complex hydride tank

    DEFF Research Database (Denmark)

    Pfeifer, P.; Wall, C.; Jensen, Jens Oluf

    2009-01-01

    Sodium alanate doped with cerium catalyst has been proven to have fast kinetics for hydrogen ab- and de-sorption as well as a high gravimetric storage density around 5 wt%. The kinetics of hydrogen sorption can be improved by preparing the alanate as nanocrystalline material. However, the second...... the possibilities of a thermal coupling of a high temperature PEM fuel cell operating at 160-200 degrees C. The starting temperatures and temperature hold-times before starting fuel cell operation, the heat transfer characteristics of the hydride storage tanks, system temperature, fuel cell electrical power...

  7. Coupled neutronic-thermal-hydraulics analysis in a coolant subchannel of a PWR using CFD techniques

    Energy Technology Data Exchange (ETDEWEB)

    Ribeiro, Felipe P.; Su, Jian, E-mail: sujian@nuclear.ufrj.br [Coordenacao de Pos-Graduacao e Pesquisa de Engenharia (COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Programa de Engenharia Nuclear

    2017-07-01

    The high capacity of Computational Fluid Dynamics code to predict multi-dimensional thermal-hydraulics behaviour and the increased availability of capable computer systems are making that method a good tool to simulate phenomena of thermal-hydraulics nature in nuclear reactors. However, since there are no neutron kinetics models available in commercial CFD codes to the present day, the application of CFD in the nuclear reactor safety analyses is still limited. The present work proposes the implementation of the point kinetics model (PKM) in ANSYS - Fluent to predict the neutronic behaviour in a Westinghouse Sequoyah nuclear reactor, coupling with the phenomena of heat conduction in the rod and thermal-hydraulics in the cooling fluid, via the reactivity feedback. Firstly, a mesh convergence and turbulence model study was performed, using the Reynolds-Average Navier-Stokes method, with square arrayed rod bundle featuring pitch to diameter ratio of 1:32. Secondly, simulations using the k-! SST turbulence model were performed with an axial distribution of the power generation in the fuel to analyse the heat transfer through the gap and cladding, and its in fluence on the thermal-hydraulics behaviour of the cooling fluid. The wall shear stress distribution for the centre-line rods and the dimensionless velocity were evaluated to validate the model, as well as the in fluence of the mass flow rate variation on the friction factor. The coupled model enabled to perform a dynamic analysis of the nuclear reactor during events of insertion of reactivity and shutdown of primary coolant pumps. (author)

  8. Simulating High Flux Isotope Reactor Core Thermal-Hydraulics via Interdimensional Model Coupling

    Energy Technology Data Exchange (ETDEWEB)

    Travis, Adam R [ORNL

    2014-05-01

    A coupled interdimensional model is presented for the simulation of the thermal-hydraulic characteristics of the High Flux Isotope Reactor core at Oak Ridge National Laboratory. The model consists of two domains a solid involute fuel plate and the surrounding liquid coolant channel. The fuel plate is modeled explicitly in three-dimensions. The coolant channel is approximated as a twodimensional slice oriented perpendicular to the fuel plate s surface. The two dimensionally-inconsistent domains are linked to one another via interdimensional model coupling mechanisms. The coupled model is presented as a simplified alternative to a fully explicit, fully three-dimensional model. Involute geometries were constructed in SolidWorks. Derivations of the involute construction equations are presented. Geometries were then imported into COMSOL Multiphysics for simulation and modeling. Both models are described in detail so as to highlight their respective attributes in the 3D model, the pursuit of an accurate, reliable, and complete solution; in the coupled model, the intent to simplify the modeling domain as much as possible without affecting significant alterations to the solution. The coupled model was created with the goal of permitting larger portions of the reactor core to be modeled at once without a significant sacrifice to solution integrity. As such, particular care is given to validating incorporated model simplifications. To the greatest extent possible, the decrease in solution time as well as computational cost are quantified versus the effects such gains have on the solution quality. A variant of the coupled model which sufficiently balances these three solution characteristics is presented alongside the more comprehensive 3D model for comparison and validation.

  9. A Proposal to Develop and Test a Fibre-Optic Coupled Solar Thermal Propulsion System for Microsatellites

    Science.gov (United States)

    2006-03-01

    b) Figure 2.2: (a) Parabolic solar cooker . (b) Fresnel solar cooker Fibre Optic Solar Thermal Propulsion Demonstration Technology 8 external...Proposal to Develop and Test a Fibre-Optic Coupled Solar Thermal Propulsion System for Microsatellites 5c. PROGRAM ELEMENT NUMBER 5d. PROJECT...report results from a contract tasking University of Surrey. Solar Thermal Propulsion (STP) previously envisioned for large spacecraft and capable of

  10. A novel integrated thermally coupled moving bed reactors for naphtha reforming process with hydrodealkylation of toluene

    International Nuclear Information System (INIS)

    Iranshahi, Davood; Saeedi, Reza; Azizi, Kolsoom; Nategh, Mahshid

    2017-01-01

    Highlights: • A novel thermally coupled reactor in CCR naphtha reforming process is modeled. • The required heat of Naphtha process is attained with toluene hydrodealkylation. • A new kinetic model involving 32 pseudo-component and 84 reactions is proposed. • The aromatics and hydrogen production increase 19% and 23%, respectively. - Abstract: Due to the importance of catalytic naphtha reforming process in refineries, development of this process to attain the highest yield of desired products is crucial. In this study, continuous catalyst regeneration naphtha reforming process with radial flow is coupled with hydrodealkylation of toluene to prevent energy loss while enhancing aromatics and hydrogen yields. In this coupled process, heat is transferred between hot and cold sections (from hydrodealkylation of toluene to catalytic naphtha reforming process) using the process integration method. A steady-state two-dimensional model, which considers coke formation on the catalyst pellets, is developed and 32 pseudo-components with 84 reactions are investigated. Kinetic model utilized for HDA process is homogeneous and non-catalytic. The modeling results reveal an approximate increase of 19% and 23% in aromatics and hydrogen molar flow rates, respectively, in comparison with conventional naphtha reforming process. The improvement in aromatics production evidently indicates that HDA is a suitable process to be coupled with naphtha reforming.

  11. An analytical study on excitation of nuclear-coupled thermal-hydraulic instability due to seismically induced resonance in BWR

    Energy Technology Data Exchange (ETDEWEB)

    Hirano, Masashi [Japan Atomic Energy Research Institute, Ibaraki-ken (Japan)

    1997-07-01

    This paper describes the results of a scoping study on seismically induced resonance of nuclear-coupled thermal-hydraulic instability in BWRs, which was conducted by using TRAC-BF1 within a framework of a point kinetics model. As a result of the analysis, it is shown that a reactivity insertion could occur accompanied by in-surge of coolant into the core resulted from the excitation of the nuclear-coupled instability by the external acceleration. In order to analyze this phenomenon more in detail, it is necessary to couple a thermal-hydraulic code with a three-dimensional nuclear kinetics code.

  12. Distillation with labelled transition systems

    DEFF Research Database (Denmark)

    Hamilton, Geoffrey William; Jones, Neil

    2012-01-01

    In this paper, we provide an improved basis for the " distillation" program transformation. It is known that superlinear speedups can be obtained using distillation, but cannot be obtained by other earlier automatic program transformation techniques such as deforestation, positive supercompilation...

  13. Coupled fully 3D neutron kinetics thermal-hydraulic computations for DNB analysis on PWRs

    International Nuclear Information System (INIS)

    Pitot, Samuel; Alborghetti, Nicolas

    2007-01-01

    Departure from Nucleate Boiling (DNB) is one of the major limiting factors of Pressurized Water Reactors (PWRs). Safety requires that occurrence of DNB should be precluded under normal or incidental operating conditions. To perform Main Steam Line Break (MSLB) accident calculations EDF have developed its own numerical tool OSCARD based on: the thermal-hydraulic THYC code for DNB analysis, the neutron kinetics COCCINELLE code for power distribution computations, the thermal-hydraulic CATHARE code to provide boundary conditions analysis with system scale computation. With OSCARD a fully three-dimensional (3D) representation of the core is proposed in conjunction with a two-phase flow porous-body approach (THYC) and two-group diffusion equations in the axial and lateral directions with Doppler and void reactivity feedback effects (COCCINELLE). OSCARD provides EDF with an alternative and independent way of evaluating fuel performance and safety margins. In the licensed approach, the coupled 3D neutron kinetics and thermal-hydraulic part of OSCARD steady computations is used to produce 3D power distribution in the reactor core at the most penalizing moment of the transient. Then this distribution is used as an input for THYC to perform thermal-hydraulic subchannel analysis. This 3 steps approach is used with simple conservative and bounding analysis assumptions, that can not occur in reality. In a prospective approach, OSCARD enables to combine thermal-hydraulic subchannel analysis with the neutron kinetics radial average channel model using a nodalization of one quarter of fuel assembly in order to perform one step DNB analysis. (author)

  14. Whole core pin-by-pin coupled neutronic-thermal-hydraulic steady state and transient calculations using COBAYA3 code

    International Nuclear Information System (INIS)

    Jimenez, J.; Herrero, J. J.; Cuervo, D.; Aragones, J. M.

    2010-10-01

    Nowadays coupled 3-dimensional neutron kinetics and thermal-hydraulic core calculations are performed by applying a radial average channel approach using a meshing of one quarter of assembly in the best case. This approach does not take into account the subchannels effects due to the averaging of the physical fields and the loose of heterogeneity in the thermal-hydraulic model. Therefore the models do not have enough resolution to predict those subchannels effects which are important for the fuel design safety margins, because it is in the local scale, where we can search the hottest pellet or the maximum heat flux. The Polytechnic University of Madrid advanced multi-scale neutron-kinetics and thermal-hydraulics methodologies being implemented in COBAYA3 include domain decomposition by alternate core dissections for the local 3-dimensional fine-mesh scale problems (pin cells/subchannels) and an analytical nodal diffusion solver for the coarse mesh scale coupled with the thermal-hydraulic using a model of one channel per assembly or per quarter of assembly. In this work, we address the domain decomposition by the alternate core dissections methodology applied to solve coupled 3-dimensional neutronic-thermal-hydraulic problems at the fine-mesh scale. The neutronic-thermal-hydraulic coupling at the cell-subchannel scale allows the treatment of the effects of the detailed thermal-hydraulic feedbacks on cross-sections, thus resulting in better estimates of the local safety margins at the pin level. (Author)

  15. Modeling and temperature regulation of a thermally coupled reactor system via internal model control strategy

    Energy Technology Data Exchange (ETDEWEB)

    Lee, S.Y.; Coronella, C.J.; Bhadkamkar, A.S.; Seader, J.D. [Univ. of Utah, Salt Lake City, UT (United States). Dept. of Chemical and Fuels Engineering

    1993-12-01

    A two-stage, thermally coupled fluidized-bed reactor system has been developed for energy-efficient conversion of tar-sand bitumen to synthetic crude oil. Modeling and temperature control of a system are addressed in this study. A process model and transfer function are determined by a transient response technique and the reactor temperature are controlled by PI controllers with tuning settings determined by an internal model control (IMC) strategy. Using the IMC tuning method, sufficiently good control performance was experimentally observed without lengthy on-line tuning. It is shown that IMC strategy provides a means to directly use process knowledge to make a control decision. Although this control method allows for fine tuning by adjusting a single tuning parameter, it is not easy to determine the optimal value of this tuning parameter, which must be specified by the user. A novel method is presented to evaluate that parameter, which must be specified by the user. A novel method is presented to evaluate that parameter in this study. It was selected based on the magnitude of elements on the off-diagonal of the relative gain array to account for the effect of thermal coupling on control performance. It is shown that this method provides stable and fast control of reactor temperatures. By successfully decoupling the system, a simple method of extending the IMC tuning technique to multiinput/multioutput systems is obtained.

  16. Bioconjugate functionalization of thermally carbonized porous silicon using a radical coupling reaction†

    Science.gov (United States)

    Sciacca, Beniamino; Alvarez, Sara D.; Geobaldo, Francesco; Sailor, Michael J.

    2011-01-01

    The high stability of Salonen’s thermally carbonized porous silicon (TCPSi) has attracted attention for environmental and biochemical sensing applications, where corrosion-induced zero point drift of porous silicon-based sensor elements has historically been a significant problem. Prepared by the high temperature reaction of porous silicon with acetylene gas, the stability of this silicon carbide-like material also poses a challenge—many sensor applications require a functionalized surface, and the low reactivity of TCPSi has limited the ability to chemically modify its surface. This work presents a simple reaction to modify the surface of TCPSi with an alkyl carboxylate. The method involves radical coupling of a dicarboxylic acid (sebacic acid) to the TCPSi surface using a benzoyl peroxide initiator. The grafted carboxylic acid species provides a route for bioconjugate chemical modification, demonstrated in this work by coupling propylamine to the surface carboxylic acid group through the intermediacy of pentafluorophenol and 1-ethyl-3-[3-dimethylaminopropyl]carbodiimide hydrochloride (EDC). The stability of the carbonized porous Si surface, both before and after chemical modification, is tested in phosphate buffered saline solution and found to be superior to either hydrosilylated (with undecylenic acid) or thermally oxidized porous Si surfaces. PMID:20967329

  17. The performance of residential micro-cogeneration coupled with thermal and electrical storage

    Science.gov (United States)

    Kopf, John

    Over 80% of residential secondary energy consumption in Canada and Ontario is used for space and water heating. The peak electricity demands resulting from residential energy consumption increase the reliance on fossil-fuel generation stations. Distributed energy resources can help to decrease the reliance on central generation stations. Presently, distributed energy resources such as solar photovoltaic, wind and bio-mass generation are subsidized in Ontario. Micro-cogeneration is an emerging technology that can be implemented as a distributed energy resource within residential or commercial buildings. Micro-cogeneration has the potential to reduce a building's energy consumption by simultaneously generating thermal and electrical power on-site. The coupling of a micro-cogeneration device with electrical storage can improve the system's ability to reduce peak electricity demands. The performance potential of micro-cogeneration devices has yet to be fully realized. This research addresses the performance of a residential micro-cogeneration device and it's ability to meet peak occupant electrical loads when coupled with electrical storage. An integrated building energy model was developed of a residential micro-cogeneration system: the house, the micro-cogeneration device, all balance of plant and space heating components, a thermal storage device, an electrical storage device, as well as the occupant electrical and hot water demands. This model simulated the performance of a micro-cogeneration device coupled to an electrical storage system within a Canadian household. A customized controller was created in ESP-r to examine the impact of various system control strategies. The economic performance of the system was assessed from the perspective of a local energy distribution company and an end-user under hypothetical electricity export purchase price scenarios. It was found that with certain control strategies the micro-cogeneration system was able to improve the

  18. Bis(triisopropylsilylethynyl)pentacene/Au(111) interface: Coupling, molecular orientation, and thermal stability

    KAUST Repository

    Gnoli, Andrea

    2014-10-02

    The assembly and the orientation of functionalized pentacene at the interface with inorganics strongly influence both the electric contact and the charge transport in organic electronic devices. In this study electronic spectroscopies and theoretical modeling are combined to investigate the properties of the bis(triisopropylsilylethynyl)pentacene (TIPS-Pc)/Au(111) interface as a function of the molecular coverage to compare the molecular state in the gas phase and in the adsorbed phase and to determine the thermal stability of TIPS-Pc in contact with gold. Our results show that in the free molecule only the acene atoms directly bonded to the ligands are affected by the functionalization. Adsorption on Au(111) leads to a weak coupling which causes only modest binding energy shifts in the TIPS-Pc and substrate core level spectra. In the first monolayer the acene plane form an angle of 33 ± 2° with the Au(111) surface at variance with the vertical geometry reported for thicker solution-processed or evaporated films, whereas the presence of configurational disorder was observed in the multilayer. The thermal annealing of the TIPS-Pc/Au(111) interface reveals the ligand desorption at ∼470 K, which leaves the backbone of the decomposed molecule flat-lying on the metal surface as in the case of the unmodified pentacene. The weak interaction with the metal substrate causes the molecular dissociation to occur 60 K below the thermal decomposition taking place in thick drop-cast films.

  19. Numerical modelling of levee stability based on coupled mechanical, thermal and hydrogeological processes

    Directory of Open Access Journals (Sweden)

    Dwornik Maciej

    2016-01-01

    Full Text Available The numerical modelling of coupled mechanical, thermal and hydrogeological processes for a soil levee is presented in the paper. The modelling was performed for a real levee that was built in Poland as a part of the ISMOP project. Only four parameters were changed to build different flood waves: the water level, period of water increase, period of water decrease, and period of low water level after the experiment. Results of numerical modelling shows that it is possible and advisable to calculate simultaneously changes of thermal and hydro-mechanical fields. The presented results show that it is also possible to use thermal sensors in place of more expensive pore pressure sensors, with some limitations. The results of stability analysis show that the levee is less stable when the water level decreases, after which factor of safety decreases significantly. For all flooding wave parameters described in the paper, the levee is very stable and factor of safety variations for any particular stage were not very large.

  20. ARCADIAR - A New Generation of Coupled Neutronics / Core Thermal- Hydraulics Code System at AREVA NP

    International Nuclear Information System (INIS)

    Curca-Tivig, Florin; Merk, Stephan; Pautz, Andreas; Thareau, Sebastien

    2007-01-01

    Anticipating future needs of our customers and willing to concentrate synergies and competences existing in the company for the benefit of our customers, AREVA NP decided in 2002 to develop the next generation of coupled neutronics/ core thermal-hydraulic (TH) code systems for fuel assembly and core design calculations for both, PWR and BWR applications. The global CONVERGENCE project was born: after a feasibility study of one year (2002) and a conceptual phase of another year (2003), development was started at the beginning of 2004. The present paper introduces the CONVERGENCE project, presents the main feature of the new code system ARCADIA R and concludes on customer benefits. ARCADIA R is designed to meet AREVA NP market and customers' requirements worldwide. Besides state-of-the-art physical modeling, numerical performance and industrial functionality, the ARCADIA R system is featuring state-of-the-art software engineering. The new code system will bring a series of benefits for our customers: e.g. improved accuracy for heterogeneous cores (MOX/ UOX, Gd...), better description of nuclide chains, and access to local neutronics/ thermal-hydraulics and possibly thermal-mechanical information (3D pin by pin full core modeling). ARCADIA is a registered trademark of AREVA NP. (authors)

  1. Metal/dielectric thermal interfacial transport considering cross-interface electron-phonon coupling: Theory, two-temperature molecular dynamics, and thermal circuit

    Science.gov (United States)

    Lu, Zexi; Wang, Yan; Ruan, Xiulin

    2016-02-01

    The standard two-temperature equations for electron-phonon coupled thermal transport across metal/nonmetal interfaces are modified to include the possible coupling between metal electrons with substrate phonons. The previous two-temperature molecular dynamics (TT-MD) approach is then extended to solve these equations numerically at the atomic scale, and the method is demonstrated using Cu/Si interface as an example. A key parameter in TT-MD is the nonlocal coupling distance of metal electrons and nonmetal phonons, and here we use two different approximations. The first is based on Overhauser's "joint-modes" concept, while we use an interfacial reconstruction region as the length scale of joint region rather than the phonon mean-free path as in Overhauser's original model. In this region, the metal electrons can couple to the joint phonon modes. The second approximation is the "phonon wavelength" concept where electrons couple to phonons nonlocally within the range of one phonon wavelength. Compared with the original TT-MD, including the cross-interface electron-phonon coupling can slightly reduce the total thermal boundary resistance. Whether the electron-phonon coupling within the metal block is nonlocal or not does not make an obvious difference in the heat transfer process. Based on the temperature profiles from TT-MD, we construct a new mixed series-parallel thermal circuit. We show that such a thermal circuit is essential for understanding metal/nonmetal interfacial transport, while calculating a single resistance without solving temperature profiles as done in most previous studies is generally incomplete. As a comparison, the simple series circuit that neglects the cross-interface electron-phonon coupling could overestimate the interfacial resistance, while the simple parallel circuit in the original Overhauser's model underestimates the total interfacial resistance.

  2. Ordering and thermal excitations in dipolar coupled single domain magnet arrays (Presentation Recording)

    Science.gov (United States)

    Östman, Erik; Arnalds, Unnar; Kapaklis, Vassilios; Hjörvarsson, Björgvin

    2015-09-01

    For a small island of a magnetic material the magnetic state of the island is mainly determined by the exchange interaction and the shape anisotropy. Two or more islands placed in close proximity will interact through dipolar interactions. The state of a large system will thus be dictated by interactions at both these length scales. Enabling internal thermal fluctuations, e.g. by the choice of material, of the individual islands allows for the study of thermal ordering in extended nano-patterned magnetic arrays [1,2]. As a result nano-magnetic arrays represent an ideal playground for the study of physical model systems. Here we present three different studies all having used magneto-optical imaging techniques to observe, in real space, the order of the systems. The first study is done on a square lattice of circular islands. The remanent magnetic state of each island is a magnetic vortex structure and we can study the temperature dependence of the vortex nucleation and annihilation fields [3]. The second are long chains of dipolar coupled elongated islands where the magnetization direction in each island only can point in one of two possible directions. This creates a system which in many ways mimics the Ising model [4] and we can relate the correlation length to the temperature. The third one is a spin ice system where elongated islands are placed in a square lattice. Thermal excitations in such systems resemble magnetic monopoles [2] and we can investigate their properties as a function of temperature and lattice parameters. [1] V. Kapaklis et al., New J. Phys. 14, 035009 (2012) [2] V. Kapaklis et al., Nature Nanotech 9, 514(2014) [3] E. Östman et al.,New J. Phys. 16, 053002 (2014) [4] E. Östman et al.,Thermal ordering in mesoscopic Ising chains, In manuscript.

  3. Coupled neutronics and thermal hydraulics of high density cores for FRM II

    Energy Technology Data Exchange (ETDEWEB)

    Breitkreutz, Harald

    2011-03-04

    According to the 'Verwaltungsvereinbarung zwischen Bund und Land vom 30.5.2003' and its updating on 13.11.2010, the Forschungs-Neutronenquelle Heinz Maier-Leibnitz, Frm II, has to convert its fuel element to an uranium enrichment which is significantly lower than the current 93%, in case this is economically reasonable and doesn't impact the reactor performance immoderate. In the framework of this conversion, new calculations regarding neutronics and thermal hydraulics for the anticipated core configurations have to be made. The computational power available nowadays allows for detailed 3D calculations, on the neutronic as well as on the thermal hydraulic side. In this context, a new program system, 'X{sup 2}', was developed. It couples the Monte Carlo code McnpX, the computational fluid dynamics code Cfx and the burn-up code sequence MonteBurns. The codes were modified and extended to meet the requirements of the coupled calculation concept. To verify the new program system, highly detailed calculations for the current fuel element were made and compared to simulations and measurements that were performed in the past. The results strengthen the works performed so far and show that the original, conservative approach overestimates all critical thermal hydraulic values. Using the CFD software, effects like the impact of the combs that fix the fuel plates and the pressure drop at the edges of the fuel plates were studied in great detail for the first time. Afterwards, a number of possible new fuel elements with lower enrichment, based on disperse and monolithic UMo (uranium with 8 wt.-% Mo) were analysed. A number of straight-forward conversion scenarios was discussed, showing that a further compaction of the fuel element, an extended cycle length or an increased reactor power is needed to compensate the flux loss, which is caused by the lower enrichment. This flux loss is in excess of 7%. The discussed new fuel elements include a 50

  4. Coupled neutronics and thermal hydraulics of high density cores for FRM II

    International Nuclear Information System (INIS)

    Breitkreutz, Harald

    2011-01-01

    According to the 'Verwaltungsvereinbarung zwischen Bund und Land vom 30.5.2003' and its updating on 13.11.2010, the Forschungs-Neutronenquelle Heinz Maier-Leibnitz, Frm II, has to convert its fuel element to an uranium enrichment which is significantly lower than the current 93%, in case this is economically reasonable and doesn't impact the reactor performance immoderate. In the framework of this conversion, new calculations regarding neutronics and thermal hydraulics for the anticipated core configurations have to be made. The computational power available nowadays allows for detailed 3D calculations, on the neutronic as well as on the thermal hydraulic side. In this context, a new program system, 'X 2 ', was developed. It couples the Monte Carlo code McnpX, the computational fluid dynamics code Cfx and the burn-up code sequence MonteBurns. The codes were modified and extended to meet the requirements of the coupled calculation concept. To verify the new program system, highly detailed calculations for the current fuel element were made and compared to simulations and measurements that were performed in the past. The results strengthen the works performed so far and show that the original, conservative approach overestimates all critical thermal hydraulic values. Using the CFD software, effects like the impact of the combs that fix the fuel plates and the pressure drop at the edges of the fuel plates were studied in great detail for the first time. Afterwards, a number of possible new fuel elements with lower enrichment, based on disperse and monolithic UMo (uranium with 8 wt.-% Mo) were analysed. A number of straight-forward conversion scenarios was discussed, showing that a further compaction of the fuel element, an extended cycle length or an increased reactor power is needed to compensate the flux loss, which is caused by the lower enrichment. This flux loss is in excess of 7%. The discussed new fuel elements include a 50% enriched disperse UMo core with

  5. Horizontal ground coupled heat pump: Thermal-economic modeling and optimization

    International Nuclear Information System (INIS)

    Sanaye, Sepehr; Niroomand, Behzad

    2010-01-01

    The modeling and optimizing processes of a Ground Coupled Heat Pump (GCHP) with closed Horizontal Ground Heat eXchanger (HGHX) are presented in this paper. After thermal modeling of GCHP including HGHX, the optimum design parameters of the system were estimated by minimizing a defined objective function (total of investment and operation costs) subject to a list of constraints. This procedure was performed applying Genetic Algorithm technique. For given heating/cooling loads and various climatic conditions, the optimum values of saturated temperature/pressure of condenser and evaporator as well as inlet and outlet temperatures of the water source in cooling and heating modes were predicted. Then, for our case study, the design parameters as well as the configuration of HGHX were obtained. Furthermore, the sensitivity analysis of change in the total annual cost of the system and optimum design parameters with the climatic conditions, cooling/heating capacity, and soil type were discussed.

  6. Development of a scanning microscopy by total internal reflection coupled with thermal lens spectroscopy.

    Science.gov (United States)

    Shimosaka, Takuya; Iwamoto, Kazutoshi; Izako, Masakazu; Suzuki, Asa; Uchiyama, Katsumi; Hobo, Toshiyuki

    2004-01-01

    Non-destructive measurement of a small region on a solid/liquid interface is of great importance in physical chemistry and biochemistry, especially in the research of thin films and cell membranes. Optical methods for surface analysis with high lateral resolution are suitable methods for monitoring them. We now report a new scanning optical microscopic method to which total internal reflection coupled with a thermal lens technique was introduced. Its lateral resolution was estimated both experimentally and theoretically. To experimentally estimate the resolution, the grid patterns of thin photoresist films with well-defined lateral structures were measured. The experimental resolution was about 45 microm, which was almost same as the diameter of the excitation beam at a glass/sample interface. From this result, it was verified that this new scanning microscopy ideally worked.

  7. Coupling analysis of frictional heat of fluid film and thermal deformation of mechanical seal end faces

    International Nuclear Information System (INIS)

    Zhou Jianfeng; Gu Boqin

    2007-01-01

    The heat transfer model of the rotating ring and the stationary ring of mechanical seal was built. The method to calculate the frictional heat that transferred by the rings was given. the coupling analysis of the frictional heat of fluid film and thermal deformation of end faces was carried out by using FEA and BP ANN, and the relationship among the rotational speed ω, the fluid film thickness h i on the inner diameter of sealing face and the radial separation angle β of deformed end faces was obtained. Corresponding to a given ω, h i and β can be obtained by the equilibrium condition between the closing force and the bearing force of fluid film. The relationship between the leakage rate and the closing force was analyzed, and the fundamental of controlling the leakage rate by regulating the closing force was also discussed. (authors)

  8. MCNP5 study on kinetics parameters of coupled fast-thermal system HERBE

    Directory of Open Access Journals (Sweden)

    Pešić Milan P.

    2011-01-01

    Full Text Available New validation of the well-known Monte Carlo code MCNP5 against measured criticality and kinetics data for the coupled fast-thermal HERBE System at the Reactor B critical assembly is shown in this paper. Results of earlier calculations of these criticality and kinetics parameters, done by combination of transport and diffusion codes using two-dimension geometry model are compared to results of new calculations carried out by the MCNP5 code in three-dimension geometry. Satisfactory agreements in comparison of new results with experimental data, in spite complex heterogeneous composition of the HERBE core, are achieved confirming that MCNP5 code could apply successfully to study on HERBE kinetics parameters after uncertainties in impurities in material compositions and positions of fuel elements in fast zone were removed.

  9. Hollow cathode modeling: I. A coupled plasma thermal two-dimensional model

    Science.gov (United States)

    Sary, Gaétan; Garrigues, Laurent; Boeuf, Jean-Pierre

    2017-05-01

    A two-dimensional axisymmetric quasi-neutral fluid model of an emissive hollow cathode that includes neutral xenon, single charge ions and electrons has been developed. The gas discharge is coupled with a thermal model of the cathode into a self-consistent generic model applicable to any hollow cathode design. An exhaustive description of the model assumptions and governing equations is given. Boundary conditions for both the gas discharge and thermal model are clearly specified as well. A new emissive sheath model that is valid for any emissive material and in both space charge and thermionic emission limited regimes is introduced. Then, setting the emitter temperature to an experimentally measured profile, we compare simulation results of the plasma model to measurements available in the literature for NASA NSTAR barium oxide cathode. Qualitative discrepancies between simulation results and measurements are noted in the cathode plume regarding the simulated plasma potential. Motivated by experimental evidence supporting the occurrence of ion acoustic instabilities in the cathode plume, an enhanced model of electron transport in the plume is presented and its consequences analyzed. Using the obtained plasma model, simulated quantities in the plume are qualitatively comparable with measurements. Inside the cathode, the simulated plasma density agrees well with measurements and is within the +/- 50 % experimental uncertainty associated with these measurements. A comparison of simulation results of the full coupled cathode model for the NASA NSTAR cathode with experimental measurements is presented in a companion paper, as well as a physical analysis of the cathode behavior and a parametric study of the influence of the operating point and key design choices.

  10. Interface requirements to couple thermal-hydraulic codes to severe accident codes: ATHLET-CD

    Energy Technology Data Exchange (ETDEWEB)

    Trambauer, K. [GRS, Garching (Germany)

    1997-07-01

    The system code ATHLET-CD is being developed by GRS in cooperation with IKE and IPSN. Its field of application comprises the whole spectrum of leaks and large breaks, as well as operational and abnormal transients for LWRs and VVERs. At present the analyses cover the in-vessel thermal-hydraulics, the early phases of core degradation, as well as fission products and aerosol release from the core and their transport in the Reactor Coolant System. The aim of the code development is to extend the simulation of core degradation up to failure of the reactor pressure vessel and to cover all physically reasonable accident sequences for western and eastern LWRs including RMBKs. The ATHLET-CD structure is highly modular in order to include a manifold spectrum of models and to offer an optimum basis for further development. The code consists of four general modules to describe the reactor coolant system thermal-hydraulics, the core degradation, the fission product core release, and fission product and aerosol transport. Each general module consists of some basic modules which correspond to the process to be simulated or to its specific purpose. Besides the code structure based on the physical modelling, the code follows four strictly separated steps during the course of a calculation: (1) input of structure, geometrical data, initial and boundary condition, (2) initialization of derived quantities, (3) steady state calculation or input of restart data, and (4) transient calculation. In this paper, the transient solution method is briefly presented and the coupling methods are discussed. Three aspects have to be considered for the coupling of different modules in one code system. First is the conservation of masses and energy in the different subsystems as there are fluid, structures, and fission products and aerosols. Second is the convergence of the numerical solution and stability of the calculation. The third aspect is related to the code performance, and running time.

  11. Advanced Coupled Simulation of Borehole Thermal Energy Storage Systems and Above Ground Installations

    Science.gov (United States)

    Welsch, Bastian; Rühaak, Wolfram; Schulte, Daniel O.; Bär, Kristian; Sass, Ingo

    2016-04-01

    Seasonal thermal energy storage in borehole heat exchanger arrays is a promising technology to reduce primary energy consumption and carbon dioxide emissions. These systems usually consist of several subsystems like the heat source (e.g. solarthermics or a combined heat and power plant), the heat consumer (e.g. a heating system), diurnal storages (i.e. water tanks), the borehole thermal energy storage, additional heat sources for peak load coverage (e.g. a heat pump or a gas boiler) and the distribution network. For the design of an integrated system, numerical simulations of all subsystems are imperative. A separate simulation of the borehole energy storage is well-established but represents a simplification. In reality, the subsystems interact with each other. The fluid temperatures of the heat generation system, the heating system and the underground storage are interdependent and affect the performance of each subsystem. To take into account these interdependencies, we coupled a software for the simulation of the above ground facilities with a finite element software for the modeling of the heat flow in the subsurface and the borehole heat exchangers. This allows for a more realistic view on the entire system. Consequently, a finer adjustment of the system components and a more precise prognosis of the system's performance can be ensured.

  12. Measurement of spectrum for thermal neutrons produced from H2O moderator coupled with mercury target

    International Nuclear Information System (INIS)

    Meigo, S.; Maekawa, F.; Kasugai, Y.; Nakashima, H.; Ikeda, Y.; Watanabe, N.

    2001-01-01

    In order to obtain fundamental data for the design of pulsed spallation neutron source, the slowing-down and thermalized neutrons from an H 2 O moderator coupled with the mercury target were measured using GeV proton beams at AGS (Alternative Gradient Synchrotron) in BNL (Brookhaven National Laboratory) under the ASTE (AGS-Spallation Target Experiment) collaboration. The mercury target (φ 20 cm x L 130 cm) was surrounded by a lead reflector (1 x 1 x 1 m 3 ) was irradiated by 1.94-, 12- and 24-GeV protons. The spectral intensities of thermal neutrons from the moderator are measured by the current-mode time-of-flight technique using enriched 6 Li and 7 Li glass scintillators. By this technique, only several incident pulses were needed to obtain sufficient statistics for incident energy. The results have shown that the neutron spectral intensity per proton integrated over the Maxwellian region was almost proportional to the proton energy. By moving the target along the beam direction within 15 cm, the dependence of the relative moderator position to the target on the neutron flux was also measured. With this position change, the difference with flux was found within 10%. (author)

  13. Coupled neutronics and thermal hydraulics modelling in reactor dynamics codes TRAB-3D and HEXTRAN

    International Nuclear Information System (INIS)

    Kyrki-Rajamaeki, R.; Raety, H.

    1999-01-01

    The reactor dynamics codes for transient and accident analyses inherently include the coupling of neutronics and thermal hydraulics modelling. In Finland a number of codes with 1D and 3D neutronic models have been developed, which include models also for the cooling circuits. They have been used mainly for the needs of Finnish power plants, but some of the codes have also been utilized elsewhere. The continuous validation, simultaneous development, and experiences obtained in commercial applications have considerably improved the performance and range of application of the codes. The fast operation of the codes has enabled realistic analysis of 3D core combined to a full model of the cooling circuit even in such long reactivity scenarios as ATWS. The reactor dynamics methods are developed further and new more detailed models are created for tasks related to increased safety requirements. For thermal hydraulics calculations, an accurate general flow model based on a new solution method has been developed. Although mainly intended for analysis purposes, the reactor dynamics codes also provide reference solutions for simulator applications. As computer capability increases, these more sophisticated methods can be taken into use also in simulator environments. (author)

  14. Experimental studies on a ground coupled heat pump with solar thermal collectors for space heating

    International Nuclear Information System (INIS)

    Xi, Chen; Hongxing, Yang; Lin, Lu; Jinggang, Wang; Wei, Liu

    2011-01-01

    This paper presents experimental studies on a solar-assisted ground coupled heat pump (SAGCHP) system for space heating. The system was installed at the Hebei Academy of Sciences in Shijiazhuang (lat. N38 o 03', long. E114 o 26'), China. Solar collectors are in series connection with the borehole array through plate heat exchangers. Four operation modes of the system were investigated throughout the coldest period in winter (Dec 5th to Dec 27th). The heat pump performance, borehole temperature distributions and solar colleting characteristics of the SAGCHP system are analyzed and compared when the system worked in continuous or intermittent modes with or without solar-assisted heating. The SAGCHP system is proved to perform space heating with high energy efficiency and satisfactory solar fraction, which is a promising substitute for the conventional heating systems. It is also recommended to use the collected solar thermal energy as an alternative source for the heat pump instead of recharging boreholes for heat storage because of the enormous heat capacity of the earth. -- Highlights: → We study four working modes of a solar-assisted ground coupled heat pump. → The heating performance is in direct relation with the borehole temperature. → Solar-assisted heating elevates borehole temperature and system performance. → The system shows higher efficiency over traditional heating systems in cold areas. → Solar heat is not suggested for high temperature seasonal storage.

  15. A time-dependent neutron transport model and its coupling to thermal-hydraulics

    International Nuclear Information System (INIS)

    Pautz, A.

    2001-01-01

    A new neutron transport code for time-dependent analyses of nuclear systems has been developed. The code system is based on the well-known Discrete Ordinates code DORT, which solves the steady-state neutron/photon transport equation in two dimensions for an arbitrary number of energy groups and the most common regular geometries. For the implementation of time-dependence a fully implicit first-order scheme was employed to minimize errors due to temporal discretization. This requires various modifications to the transport equation as well as the extensive use of elaborated acceleration mechanisms. The convergence criteria for fluxes, fission rates etc. had to be strongly tightened to ensure the reliability of results. To perform coupled analyses, an interface to the GRS system code ATHLET has been developed. The nodal power densities from the neutron transport code are passed to ATHLET to calculate thermal-hydraulic system parameters, e.g. fuel and coolant temperatures. These are in turn used to generate appropriate nuclear cross sections by interpolation of pre-calculated data sets for each time step. Finally, to demonstrate the transient capabilities of the coupled code system, the research reactor FRM-II has been analysed. Several design basis accidents were modelled, like the loss of off site power, loss of secondary heat sink and unintended control rod withdrawal. (author)

  16. Neutronic / thermal-hydraulic coupling with the code system Trace / Parcs

    International Nuclear Information System (INIS)

    Mejia S, D. M.; Del Valle G, E.

    2015-09-01

    The developed models for Parcs and Trace codes corresponding for the cycle 15 of the Unit 1 of the Laguna Verde nuclear power plant are described. The first focused to the neutronic simulation and the second to thermal hydraulics. The model developed for Parcs consists of a core of 444 fuel assemblies wrapped in a radial reflective layer and two layers, a superior and another inferior, of axial reflector. The core consists of 27 total axial planes. The model for Trace includes the vessel and its internal components as well as various safety systems. The coupling between the two codes is through two maps that allow its intercommunication. Both codes are used in coupled form performing a dynamic simulation that allows obtaining acceptably a stable state from which is carried out the closure of all the main steam isolation valves (MSIVs) followed by the performance of safety relief valves (SRVs) and ECCS. The results for the power and reactivities introduced by the moderator density, the fuel temperature and total temperature are shown. Data are also provided like: the behavior of the pressure in the steam dome, the water level in the downcomer, the flow through the MSIVs and SRVs. The results are explained for the power, the pressure in the steam dome and the water level in the downcomer which show agreement with the actions of the MSIVs, SRVs and ECCS. (Author)

  17. Effect of electron thermal motion on plasma heating in a magnetized inductively coupled plasma

    International Nuclear Information System (INIS)

    Aman-ur-Rehman; Pu Yikang

    2007-01-01

    Power absorbed inside the magnetized inductively coupled plasma (MICP) is calculated using three different warm MICP models and is then compared with the result of the cold MICP model. The comparison shows that in the propagating region (ω e vertical bar), under the cavity resonance conditions, warm plasma heating S warm is significantly less than the cold plasma heating S cold , unless the distance traveled by the electrons due to their thermal motion, during the effective wave period, becomes significantly less than the wavelength of the cavity wave. Furthermore, in the propagating region, when ω≅ vertical bar Ω e vertical bar, there appears a valley on the plot of η(ω)=S warm /S cold versus ω showing the negative effect of electron thermal motion on plasma heating. This valley widens and gets smoother with an increase in the plasma length. In the nonpropagating region (ω> vertical bar Ω e vertical bar), the maximum value of η(ω) exists when ω- vertical bar Ω e vertical bar ≅v th /δ, showing that, in the presence of the external magnetic field, the thermal motion of the electrons leads to a Doppler shift of the frequencies, at which collisionless heating is the dominant mode of electron heating. Furthermore, in the nonpropagating region, when ω≅ vertical bar Ω e vertical bar, the skin depth of the right circularly polarized electric field decreases with magnetic field. This decrease in the skin depth results in an increase of collisionless heating under the Doppler-shifted wave particle resonant condition of ω- vertical bar Ω e vertical bar ≅v th /δ. It is also observed that, for large plasma length, the results of all the three warm MICP models are consistent with each other

  18. Multi-scale, coupled Reactor Physics / Thermal-Hydraulics system and applications to the HPLWR 3 Pass Core

    OpenAIRE

    Monti, Lanfranco

    2009-01-01

    The HPLWR is an innovative reactor concept cooled with water at supercritical pressure. The pronounced changes of water properties with the heat-up demands advanced analyses tools which have been developed and successfully applied. Coupled neutronic/thermal-hydraulic analyses have been performed for the whole core and the coupled solution has been successively investigated at sub-channel resolution evaluating local quantities. The obtained results represent a new quality in core analyses.

  19. Coupling of unidimensional neutron kinetics to thermal hydraulics in parallel channels

    International Nuclear Information System (INIS)

    Cecenas F, M.; Campos G, R.M.

    2003-01-01

    In this work the dynamic behavior of a consistent system in fifteen channels in parallel that represent the reactor core of a BWR type, coupled of a kinetic neutronic model in one dimension is studied by means of time series. The arrangement of channels is obtained collapsing the assemblies that it consists the core to an arrangement of channels prepared in straight lines, and it is coupled to the unidimensional solution of the neutron diffusion equation. This solution represents the radial power distribution, and initially the static solution is obtained to verify that the one modeling core is critic. The coupled set nuclear-thermal hydraulics it is solved numerically by means of a net of CPUs working in the outline teacher-slave by means of Parallel Virtual Machine (PVM), subject to the restriction that the pressure drop is equal for each channel, which is executed iterating on the refrigerant distribution. The channels are dimensioned according to the one Stability Benchmark of the Ringhals swedish plant, organized by the Nuclear Energy Agency in 1994. From the information of this benchmark it is obtained the axial power profile for each channel, which is assumed as invariant in the time. To obtain the time series, the system gets excited with white noise (sequence that statistically obeys to a normal distribution with zero media), so that the power generated in each channel it possesses the same ones characteristics of a typical signal obtained by means of the acquisition of those signals of neutron flux in a BWR reactor. (Author)

  20. Qutrit magic state distillation

    International Nuclear Information System (INIS)

    Anwar, Hussain; Browne, Dan E; Campbell, Earl T

    2012-01-01

    Magic state distillation (MSD) is a purification protocol that plays an important role in fault-tolerant quantum computation. Repeated iteration of the steps of an MSD protocol generates pure single non-stabilizer states, or magic states, from multiple copies of a mixed resource state using stabilizer operations only. Thus mixed resource states promote the stabilizer operations to full universality. MSD was introduced for qubit-based quantum computation, but little has been known concerning MSD in higher-dimensional qudit-based computation. Here, we describe a general approach for studying MSD in higher dimensions. We use it to investigate the features of a qutrit MSD protocol based on the five-qutrit stabilizer code. We show that this protocol distils non-stabilizer magic states, and identify two types of states that are attractors of this iteration map. Finally, we show how these states may be converted, via stabilizer circuits alone, into a state suitable for state-injected implementation of a non-Clifford phase gate, enabling non-Clifford unitary computation. (paper)

  1. A coupled magneto-thermo-elastic problem in a perfectly conducting elastic half-space with thermal relaxation

    Directory of Open Access Journals (Sweden)

    S. K. Roy-Choudhuri

    1990-01-01

    Full Text Available In the present paper we consider the magneto-thermo-elastic wave produced by a thermal shock in a perfectly conducting elastic half-space. Here the Lord-Shulman theory of thermoelasticity [1] is used to account for the interaction between the elastic and thermal fields. The solution obtained in analytical form reduces to those of Kaliski and Nowacki [2] when the coupling between the temperature and strain fields and the relaxation time are neglected. The results also agree with those of Massalas and DaLamangas [3] in absence of the thermal relaxation time.

  2. Solar desalination by freezing and distillation

    Science.gov (United States)

    Kvajic, G.

    It is noted that among seawater desalination processes the absorption-freeze vapor compression processes based on the thermal heat pump, although untested commercially and still in the development stage, appears technically and economically an attractive application of low-grade (exergy) solar heat. The distillation processes proposed here may be conveniently powered by low-grade solar heat (from flat plate solar collectors). It is expected that the scaling problem will be insignificant in comparison with that encountered in the conventional multistage flash process. The novel feature here is the use of enlarged capacity for heat exchange between distillate and brine via latent heat of solid-liquid phase change of a suitable hydrophobic intermediate heat transfer material.

  3. 3D neutronic codes coupled with thermal-hydraulic system codes for PWR, and BWR and VVER reactors

    Energy Technology Data Exchange (ETDEWEB)

    Langenbuch, S.; Velkov, K. [GRS, Garching (Germany); Lizorkin, M. [Kurchatov-Institute, Moscow (Russian Federation)] [and others

    1997-07-01

    This paper describes the objectives of code development for coupling 3D neutronics codes with thermal-hydraulic system codes. The present status of coupling ATHLET with three 3D neutronics codes for VVER- and LWR-reactors is presented. After describing the basic features of the 3D neutronic codes BIPR-8 from Kurchatov-Institute, DYN3D from Research Center Rossendorf and QUABOX/CUBBOX from GRS, first applications of coupled codes for different transient and accident scenarios are presented. The need of further investigations is discussed.

  4. Development of a 'Coupling-by-Closure' approach between CFD and system thermal-hydraulics codes

    International Nuclear Information System (INIS)

    Cadinu, Francesco; Kudinov, Pavel

    2009-01-01

    The variety of scenarios in nuclear reactor safety analysis creates a diversity of approaches to the problem of coupling Computational Fluid Dynamics (CFD) and System Thermal-Hydraulics (STH) codes. In this paper, we focus on the development of a 'Coupling by Closure' (CC) technique. In this approach, a CFD code is used to provide closures as an input into an STH code. The STH solution defines the 'macrostate' conditions where the CFD-generated closure is needed. This technique aims to provide a solution for a class of problems where the standard closure used in STH is not valid (e.g. because of their transient nature). The water hammer phenomenon is a typical example of a transient where unsteady friction (or heat transfer) plays an important role. We demonstrate different aspects of the 'Coupling by Closure' technique on a test problem: the transient laminar flow through a sudden expansion driven by a time-dependent gradient of pressure. Unsteadiness, with its effect on friction, and the presence of 3D effects are some features this flow shares with many reactor transients. Furthermore, despite being conceptually simple, this transient cannot be reliably simulated by a STH code because of the lack of appropriate closures (unsteady loss coefficient). We show that it is possible to get around this difficulty by complementing the STH analysis with CFD simulations. By developing the CC methodology, we achieve the goal of calculating the correct mass flow rate through the system as a function of time, at a much lower computational cost than the one required by a full transient CFD simulation. Starting point of our coupling strategy is the analysis of the interplay between mass flow rate and loss coefficient in a transient flow. We show how to identify time intervals, during the transient, when no expensive unsteady CFD closure is required because the solution is not sensitive to the loss coefficient or because the latter can be calculated by steady state CFD

  5. Numerical stability analysis of coupled neutronics and thermal-hydraulics schemes and new neutronic feedback-reactions model

    International Nuclear Information System (INIS)

    Guertin, Chantal

    1995-01-01

    This thesis is part of the validation process of using coupled 3D neutronics and thermal-hydraulics codes for studying accidental situations with boiling. First part is dedicated to a numerical stability analysis of neutronics and thermal-hydraulics coupled schemes. Both explicit and semi-implicit coupling schemes were applied to solve the set of equations describing the linearized neutronics and thermal-hydraulics of point reactor. Point reactor modelling was preferred to obtain analytical expressions of eigenvalues of the discretized Systems. Stability criteria, based on eigenvalues, was calculated as well as neutronic and thermalhydraulic responses of the System following insertion of a reactivity step. Results show no severe restriction of time domain, stability wise. Actual transient calculations using coupled neutronics and thermal-hydraulics codes, like COCCINELLE and THYC developed at Electricite de France, do not show stability problems. Second part introduces surface spline as a new neutronic feedback model. The cross influences of feedback parameters is now taken into account. Moderator temperature and density were modeled. This method, simple and accurate, allows an homogeneous description of cross-sections overall operating reactor situations including accidents with boiling. (author) [fr

  6. A methodology for the coupling of RAMONA-3B neutron kinetics and TRAC-BF1 thermal-hydraulics

    International Nuclear Information System (INIS)

    Lopez, Arsenio Procopio; Morales Sandoval, Jaime B.

    2005-01-01

    The initial objective of this project was to directly couple the RAMONA and TRAC codes running on different PCs. The idea was to use the best part of each one and eliminate some of their limitations and widen the applicability of these codes to simulate different BWR and system components. It was required to try to minimize the amount of changes to present code subroutines and calculation procedures. If possible, just substitute values obtained in the parallel code. Preliminary results indicated that using a CHAN component of TRAC to model thermal-hydraulic phenomena for each neutronic channel modeled in RAMONA is rather difficult. Large amounts of CPU time consumption are obtained and lots of PCs would make this solution difficult, besides considerable large transients are introduced by the differences in thermal-hydraulic results of these codes. The substitution of the thermal-hydraulics of RAMONA, by the TRAC channel calculations, is possible but simulation of a null transient on both codes must be planed and a gradual change must be controlled by an additional supervisory subroutine. An indirect coupling of these codes, it is therefore proposed, in order to eliminate most of these limitations. In this indirect coupling, a thermal-hydraulic model of the average tube in a bundle and the global channel cooling fluid dynamics is programmed for each neutronic channel while the global reactor vessel and core is modeled by TRAC with just four channels and four rings. Results are more reliable, coupling is simpler and faster simulations are possible

  7. Direct Numerical Simulations of Concentration and Temperature Polarization in Direct Contact Membrane Distillation

    Science.gov (United States)

    Lou, Jincheng; Tilton, Nils

    2017-11-01

    Membrane distillation (MD) is a method of desalination with boundary layers that are challenging to simulate. MD is a thermal process in which warm feed and cool distilled water flow on opposite sides of a hydrophobic membrane. The temperature difference causes water to evaporate from the feed, travel through the membrane, and condense in the distillate. Two challenges to MD are temperature and concentration polarization. Temperature polarization represents a reduction in the transmembrane temperature difference due to heat transfer through the membrane. Concentration polarization describes the accumulation of solutes near the membrane. These phenomena reduce filtration and lead to membrane fouling. They are difficult to simulate due to the coupling between the velocity, temperature, and concentration fields on the membrane. Unsteady regimes are particularly challenging because noise at the outlets can pollute the near-membrane flow fields. We present the development of a finite-volume method for the simulation of fluid flow, heat, and mass transport in MD systems. Using the method, we perform a parametric study of the polarization boundary layers, and show that the concentration boundary layer shows self-similar behavior that satisfies power laws for the downstream growth. Funded by the U.S. Bureau of Reclamation.

  8. Mode coupling theory for nonequilibrium glassy dynamics of thermal self-propelled particles.

    Science.gov (United States)

    Feng, Mengkai; Hou, Zhonghuai

    2017-06-28

    We present a mode coupling theory study for the relaxation and glassy dynamics of a system of strongly interacting self-propelled particles, wherein the self-propulsion force is described by Ornstein-Uhlenbeck colored noise and thermal noises are included. Our starting point is an effective Smoluchowski equation governing the distribution function of particle positions, from which we derive a memory function equation for the time dependence of density fluctuations in nonequilibrium steady states. With the basic assumption of the absence of macroscopic currents and standard mode coupling approximation, we can obtain expressions for the irreducible memory function and other relevant dynamic terms, wherein the nonequilibrium character of the active system is manifested through an averaged diffusion coefficient D[combining macron] and a nontrivial structural function S 2 (q) with q being the magnitude of wave vector q. D[combining macron] and S 2 (q) enter the frequency term and the vertex term for the memory function, and thus influence both the short time and the long time dynamics of the system. With these equations obtained, we study the glassy dynamics of this thermal self-propelled particle system by investigating the Debye-Waller factor f q and relaxation time τ α as functions of the persistence time τ p of self-propulsion, the single particle effective temperature T eff as well as the number density ρ. Consequently, we find the critical density ρ c for given τ p shifts to larger values with increasing magnitude of propulsion force or effective temperature, in good accordance with previously reported simulation work. In addition, the theory facilitates us to study the critical effective temperature T for fixed ρ as well as its dependence on τ p . We find that T increases with τ p and in the limit τ p → 0, it approaches the value for a simple passive Brownian system as expected. Our theory also well recovers the results for passive systems and can be

  9. Numerical modeling of coupled thermal chemical reactive transport: simulation of a heat storage system

    Science.gov (United States)

    Shao, H.; Watanabe, N.; Singh, A. K.; Nagel, T.; Linder, M.; Woerner, A.; Kolditz, O.

    2012-12-01

    As a carbon-free energy supply technology, the operation time and final energy output of thermal solar power plants can be greatly extended if efficient thermal storage systems are applied. One of the proposed design of such system is to utilize reversible thermochemical reactions and its embedded reaction enthalpy, e.g. the Ca(OH)2/CaO hydration circle, in a fixed-bed gas-solid reactor (Schaube et al. 2011) The modeling of such a storage system involves multiple strongly-coupled physical and chemical processes. Seepage velocity is calculated by the nonlinear Forchheimer law. Gas phase density and viscosity are temperature, pressure and composition dependent. Also, heat transfer between gas and solid phases is largely influenced by the exothermal heat produced by the hydration of calcium oxide. Numerical solution of four governing PDEs include the mass balance, reactive transport, heat balance equations for gas and solid phases, which are implemented into the open source scientific software OpenGeoSys in a monolithic way. Based on it, a 2D numerical model, considering the boundary heat loss of the system, was set up to simulate the energy-storage and release circle. The high performance computing techniques were employed in two stages. First, the dynamic behavior of the heat storage system is simulated on a parallel platform. Second, a large number of processors are employed to perform sensitivity analysis, whereas the reaction rates and efficiency factor of heat transfer are parameterized so that the measured and simulated temperature profile fit with each other. The model showed that heat transfer coefficient between solid and gas phase, grain size of the filling material will influence the final performance greatly. By varying these factors, the calibrated model will be further applied to optimize the design of such energy storage system.

  10. Stability analysis of BWR nuclear-coupled thermal-hyraulics using a simple model

    Energy Technology Data Exchange (ETDEWEB)

    Karve, A.A.; Rizwan-uddin; Dorning, J.J. [Univ. of Virginia, Charlottesville, VA (United States)

    1995-09-01

    A simple mathematical model is developed to describe the dynamics of the nuclear-coupled thermal-hydraulics in a boiling water reactor (BWR) core. The model, which incorporates the essential features of neutron kinetics, and single-phase and two-phase thermal-hydraulics, leads to simple dynamical system comprised of a set of nonlinear ordinary differential equations (ODEs). The stability boundary is determined and plotted in the inlet-subcooling-number (enthalpy)/external-reactivity operating parameter plane. The eigenvalues of the Jacobian matrix of the dynamical system also are calculated at various steady-states (fixed points); the results are consistent with those of the direct stability analysis and indicate that a Hopf bifurcation occurs as the stability boundary in the operating parameter plane is crossed. Numerical simulations of the time-dependent, nonlinear ODEs are carried out for selected points in the operating parameter plane to obtain the actual damped and growing oscillations in the neutron number density, the channel inlet flow velocity, and the other phase variables. These indicate that the Hopf bifurcation is subcritical, hence, density wave oscillations with growing amplitude could result from a finite perturbation of the system even where the steady-state is stable. The power-flow map, frequently used by reactor operators during start-up and shut-down operation of a BWR, is mapped to the inlet-subcooling-number/neutron-density (operating-parameter/phase-variable) plane, and then related to the stability boundaries for different fixed inlet velocities corresponding to selected points on the flow-control line. The stability boundaries for different fixed inlet subcooling numbers corresponding to those selected points, are plotted in the neutron-density/inlet-velocity phase variable plane and then the points on the flow-control line are related to their respective stability boundaries in this plane.

  11. Constraint control of distillation processes

    NARCIS (Netherlands)

    Roffel, B.; Fontein, H.J.

    1979-01-01

    There is a growing interest to design and operate chemical processes for reduced energy consumption. As an example a comparison is made between the distillation of binary mixtures in a conventional distillation column, a vapour recompression system and a two column heat integrated system. For all

  12. Optimization of Borehole Thermal Energy Storage System Design Using Comprehensive Coupled Simulation Models

    Science.gov (United States)

    Welsch, Bastian; Rühaak, Wolfram; Schulte, Daniel O.; Formhals, Julian; Bär, Kristian; Sass, Ingo

    2017-04-01

    Large-scale borehole thermal energy storage (BTES) is a promising technology in the development of sustainable, renewable and low-emission district heating concepts. Such systems consist of several components and assemblies like the borehole heat exchangers (BHE), other heat sources (e.g. solarthermics, combined heat and power plants, peak load boilers, heat pumps), distribution networks and heating installations. The complexity of these systems necessitates numerical simulations in the design and planning phase. Generally, the subsurface components are simulated separately from the above ground components of the district heating system. However, as fluid and heat are exchanged, the subsystems interact with each other and thereby mutually affect their performances. For a proper design of the overall system, it is therefore imperative to take into account the interdependencies of the subsystems. Based on a TCP/IP communication we have developed an interface for the coupling of a simulation package for heating installations with a finite element software for the modeling of the heat flow in the subsurface and the underground installations. This allows for a co-simulation of all system components, whereby the interaction of the different subsystems is considered. Furthermore, the concept allows for a mathematical optimization of the components and the operational parameters. Consequently, a finer adjustment of the system can be ensured and a more precise prognosis of the system's performance can be realized.

  13. An approach to modeling coupled thermal-hydraulic-chemical processes in geothermal systems

    Science.gov (United States)

    Palguta, Jennifer; Williams, Colin F.; Ingebritsen, Steven E.; Hickman, Stephen H.; Sonnenthal, Eric

    2011-01-01

    Interactions between hydrothermal fluids and rock alter mineralogy, leading to the formation of secondary minerals and potentially significant physical and chemical property changes. Reactive transport simulations are essential for evaluating the coupled processes controlling the geochemical, thermal and hydrological evolution of geothermal systems. The objective of this preliminary investigation is to successfully replicate observations from a series of hydrothermal laboratory experiments [Morrow et al., 2001] using the code TOUGHREACT. The laboratory experiments carried out by Morrow et al. [2001] measure permeability reduction in fractured and intact Westerly granite due to high-temperature fluid flow through core samples. Initial permeability and temperature values used in our simulations reflect these experimental conditions and range from 6.13 × 10−20 to 1.5 × 10−17 m2 and 150 to 300 °C, respectively. The primary mineralogy of the model rock is plagioclase (40 vol.%), K-feldspar (20 vol.%), quartz (30 vol.%), and biotite (10 vol.%). The simulations are constrained by the requirement that permeability, relative mineral abundances, and fluid chemistry agree with experimental observations. In the models, the granite core samples are represented as one-dimensional reaction domains. We find that the mineral abundances, solute concentrations, and permeability evolutions predicted by the models are consistent with those observed in the experiments carried out by Morrow et al. [2001] only if the mineral reactive surface areas decrease with increasing clay mineral abundance. This modeling approach suggests the importance of explicitly incorporating changing mineral surface areas into reactive transport models.

  14. Elimination of Thermally Generated Charge in Charged Coupled Devices Using Bayesian Estimator

    Directory of Open Access Journals (Sweden)

    J. Svihlik

    2008-06-01

    Full Text Available This paper deals with advanced methods for elimination of thermally generated charge in astronomical images, which were acquired by a Charged Coupled Device (CCD sensor. There exist a number of light images acquired by telescope, which were not corrected by dark frame. The reason is simple: the dark frame doesn't exist, because it was not acquired. This situation may for instance come when sufficient memory space is not available. Correction methods based on the modeling of the light and dark image in the wavelet domain will be discussed. As the model for the dark frame image and for the light image the generalized Laplacian was chosen. The model parameters were estimated using moment method, whereas an extensive measurement on an astronomical camera was proposed and done. This measurement simplifies estimation of the dark frame model parameters. Finally a set of astronomical testing images was corrected and then the objective criteria for an image quality evaluation based on the aperture photometry were applied.

  15. Influence of void effects on reactivity of coupled fast-thermal system HERBE

    International Nuclear Information System (INIS)

    Ljubenov, V.; Milovanovic, S.; Milovanovic, T.; Cuknic, O.

    1997-01-01

    Coupled fast-thermal system HERBE at the experimental zero power heavy water reactor RB is a system with the significant effects of the neutron leakage and neutron absorption. Presence of a coolant void introduces a new structure in an extremely heterogeneous core. In those conditions satisfactory results of the calculation are acquired only using specified space-energy homogenization procedure. In order to analyze transient appearances and accidental cases of the reactor systems, a procedure for modeling of influence of moderator and coolant loss on reactivity ('void effect') is developed. Reduction of the moderator volume fraction in some fuel channels due to air gaps or steam generation during the accidental moderator boiling, restricts validity of the diffusion approximation in the reactor calculations. In cases of high neutron flux gradients, which are consequence of high neutron absorption, application of diffusion approximation is questionable too. The problem may be solved using transport or Monte Carlo methods, but they are not acceptable in the routine applications. Applying new techniques based on space-energy core homogenization, such as the SPH method or the discontinuity factor method, diffusion calculations become acceptable. Calculations based on the described model show that loss of part of moderator medium introduce negative reactivity in the HERBE system. Calculated local void reactivity coefficients are used in safety analysis of hypothetical accidents

  16. Electromagnetic-thermal-structural coupling analysis of the ITER edge localized mode coil with flexible supports

    Science.gov (United States)

    Zhang, Shanwen; Song, Yuntao; Tang, Linlin; Wang, Zhongwei; Ji, Xiang; Du, Shuangsong

    2017-05-01

    In a fusion reactor, the edge localized mode (ELM) coil has a mitigating effect on the ELMs of the plasma. The coil is placed close to the plasma between the vacuum vessel and the blanket to reduce its design power and improve its mitigating ability. The coil works in a high-temperature, high-nuclear-heat and high-magnetic-field environment. Due to the existence of outer superconducting coils, the coil is subjected to an alternating electromagnetic force induced by its own alternating current and the outer magnetic field. The design goal for the ELM coil is to maintain its structural integrity in the multi-physical field. Taking as an example the middle ELM coil (with flexible supports) of ITER (the International Thermonuclear Fusion Reactor), an electromagnetic-thermal-structural coupling analysis is carried out using ANSYS. The results show that the flexible supports help the three-layer casing meet the static and fatigue design requirements. The structural design of the middle ELM coil is reasonable and feasible. The work described in this paper provides the theoretical basis and method for ELM coil design.

  17. Low temperature thermally regenerative electrochemical system

    Science.gov (United States)

    Loutfy, Raouf O.; Brown, Alan P.; Yao, Neng-Ping

    1983-01-01

    A thermally regenerative electrochemical system including an electrochemical cell with two water-based electrolytes separated by an ion exchange membrane, at least one of the electrolytes containing a complexing agent and a salt of a multivalent metal whose respective order of potentials for a pair of its redox couples is reversible by a change in the amount of the complexing agent in the electrolyte, the complexing agent being removable by distillation to cause the reversal.

  18. Low-temperature thermally regenerative electrochemical system

    Science.gov (United States)

    Loutfy, R.O.; Brown, A.P.; Yao, N.P.

    1982-04-21

    A thermally regenerative electrochemical system is described including an electrochemical cell with two water-based electrolytes separated by an ion exchange membrane, at least one of the electrolytes containing a complexing agent and a salt of a multivalent metal whose respective order of potentials for a pair of its redox couples is reversible by a change in the amount of the ocmplexing agent in the electrolyte, the complexing agent being removable by distillation to cause the reversal.

  19. Heat Rate Enhancement of IGCC Power Plant Coupled with Solar thermal power plant

    OpenAIRE

    Kotdawala, Rasesh R; V., Jyothi; Kanaujia, Gaurav; Adapa, Bharath

    2016-01-01

    Integrated gasification  combined cycle power plant (IGCC) has shown the potential of having higher operating thermal efficiency, than supercritical thermal power plants as it combines the advantages of coal gasification and combined cycle power plant. Solar thermal plant has shown great promise to augment the thermal efficiency of the fossil based power plants and reducing CO2 emissions. In this research paper, impact of integrating solar thermal power plant utilizing linear Fresnel collecto...

  20. Final Report: Improving the understanding of the coupled thermal-mechanical-hydrologic behavior of consolidating granular salt

    Energy Technology Data Exchange (ETDEWEB)

    Stormont, John [Univ. of New Mexico, Albuquerque, NM (United States); Lampe, Brandon [Univ. of New Mexico, Albuquerque, NM (United States); Mills, Melissa [Univ. of New Mexico, Albuquerque, NM (United States); Paneru, Laxmi [Univ. of New Mexico, Albuquerque, NM (United States); Lynn, Timothy [Univ. of New Mexico, Albuquerque, NM (United States); Piya, Aayush [Univ. of New Mexico, Albuquerque, NM (United States)

    2017-09-09

    The goal of this project is to improve the understanding of key aspects of the coupled thermal-mechanical-hydrologic response of granular (or crushed) salt used as a seal material for shafts, drifts, and boreholes in mined repositories in salt. The project is organized into three tasks to accomplish this goal: laboratory measurements of granular salt consolidation (Task 1), microstructural observations on consolidated samples (Task 2), and constitutive model development and evaluation (Task 3). Task 1 involves laboratory measurements of salt consolidation along with thermal properties and permeability measurements conducted under a range of temperatures and stresses expected for potential mined repositories in salt. Testing focused on the role of moisture, temperature and stress state on the hydrologic (permeability) and thermal properties of consolidating granular salt at high fractional densities. Task 2 consists of microstructural observations made on samples after they have been consolidated to interpret deformation mechanisms and evaluate the ability of the constitutive model to predict operative mechanisms under different conditions. Task 3 concerns the development of the coupled thermal-mechanical-hydrologic constitutive model for granular salt consolidation. The measurements and observations in Tasks 1 and 2 were used to develop a thermal-mechanical constitutive model. Accomplishments and status from each of these efforts is reported in subsequent sections of this report

  1. IRPhE/RRR-SEG, Reactor Physics Experiments from Fast-Thermal Coupled Facility

    International Nuclear Information System (INIS)

    Weiss, Frank-Peter; Dietze, Klaus; Jacqmin, Robert; Ishikawa, Makoto

    2003-01-01

    1 - Description: The RRR-SEG-experiments have been performed to check neutron data of the most important reactor materials, especially of fission product nuclides, fuel isotopes and structural materials. The measured central reactivity worths (CRW) of small samples were compared with calculated values. These C/E-ratios have been used then for data corrections or in adjustment procedures. The reactor RRG-SEG (at RC Rossendorf / Germany) was a fast-thermal coupled facility of zero power. The annular thermal drivers were filled by fuel assemblies and moderated by water. The inner insertion lattices were loaded with pellets of fuel and other materials producing the fast neutron flux. The characteristics of the neutron and adjoint spectra were obtained by special arrangements of these pellets in unit cells. In this way, a hard or soft neutron spectrum or a special energy behavior of the adjoint function could be reached. The samples were moved by means of tubes to the central position (pile-oscillation technique). The original information about the facility and measurements is compiled in Note Technique SPRC/LEPh/93-230 (SEG) The SEG experiments are considered 'clean' integral experiments, simple and clear in geometry and well suited for calculation. In all SEG configurations only a few materials were used, most of these were standards. Due to the designed adjoint function (energy-independent or monotonously rising), the capture or scattering effect was dominant, convenient to check separately capture or scattering data. At first, analyses of the experiments have been performed in Rossendorf. Newer analyses were done later in Cadarache / CEA France using the European scheme for reactor calculation JEF-2.2 / ECCO / ERANOS (see Note Techniques and JEF/DOC-746). Furthermore, re-analyses were performed in O-arai / JNC Japan with the JNC standard route JENDL-3.2 / SLAROM / CITATION / PERKY. Results obtained with both code systems and different data evaluations (JEF-2.2 and

  2. IRPhE/STEK, Reactor Physics Experiments from Fast-Thermal Coupled Facility

    International Nuclear Information System (INIS)

    Dietze, Klaus; Klippel, Henk Th.; Koning, Arjan; Jacqmin, Robert

    2003-01-01

    1 - Description: The STEK-experiments have been performed to check neutron data of the most important reactor materials, especially of fission product nuclides, fuel isotopes and structural materials. The measured central reactivity worths (CRW) of small samples were compared with calculated values. These C/E-ratios have been used then for data corrections or in adjustment procedures. The reactors STEK (ECN Petten/ Netherlands) was a fast-thermal coupled facility of zero power. The annular thermal drivers were filled by fuel assemblies and moderated by water. The inner insertion lattices were loaded with pellets of fuel and other materials producing the fast neutron flux. The characteristics of the neutron and adjoint spectra were obtained by special arrangements of these pellets in unit cells. In this way, a hard or soft neutron spectrum or a special energy behavior of the adjoint function could be reached. The samples were moved by means of tubes to the central position (pile-oscillation technique). The original information about the facility and measurements is compiled in RCN-209, ECN-10 The 5 STEK configurations cover a broad energy range due to their increasing softness. The experiments are very valuable because of the extensive program of sample reactivity measurements with many fission product nuclides important in reactor burn-up calculations. At first, analyses of the experiments have been performed in Petten. Newer analyses were done later in Cadarache / CEA France using the European scheme for reactor calculation JEF-2.2 / ECCO / ERANOS (see Note Techniques and JEF/DOC-746). Furthermore, re-analyses were performed in O-arai / JNC Japan with the JNC standard route JENDL-3.2 / SLAROM / CITATION / PERKY. Results obtained with both code systems and different data evaluations (JEF-2.2 and JENDL-3.2) are compared in JEF/DOC-861. It contains the following documents: 31 Reports, 2 publications, 5 JEF documents, 4 conferences. 2 - Related or auxiliary programs

  3. Thermal-hydraulics/thermal-mechanics temporal coupling for unprotected loss of flow accidents simulations on a SFR

    Directory of Open Access Journals (Sweden)

    Patricot Cyril

    2016-01-01

    Full Text Available In the frame of ASTRID designing, unprotected loss of flow (ULOF accidents are considered. As the reactor is not scrammed, power evolution is driven by neutronic feedbacks, among which Doppler effect, linked to fuel temperature, is prominent. Fuel temperature is calculated using thermal properties of fuel pins (we will focus on heat transfer coefficient between fuel pellet and cladding, Hgap, and on fuel thermal conductivity, λfuel which vary with irradiation conditions (neutronic flux, mass flow and history for instance and during transient (mainly because of dilatation of materials with temperature. In this paper, we propose an analysis of the impact of spatial variation and temporal evolution of thermal properties of fuel pins on a CFV-like core [M.S. Chenaud et al., Status of the ASTRID core at the end of the pre-conceptual design phase 1, in Proceedings of ICAPP 2013, Jeju Island, Korea (2013] behavior during an ULOF accident. These effects are usually neglected under some a priori conservative assumptions. The vocation of our work is not to provide a best-estimate calculation of ULOF transient, but to discuss some of its physical aspects. To achieve this goal, we used TETAR, a thermal-hydraulics system code developed by our team to calculate ULOF transients, GERMINAL V1.5, a CEA code dedicated to SFR pin thermal-mechanics calculations and APOLLO3®, a neutronic code in development at CEA.

  4. ITER task T48 (1994); low-inventory cryogenic distillation tests

    International Nuclear Information System (INIS)

    Woodall, K.; Robins, J.; Bellamy, D.

    1995-01-01

    Previous work at Ontario Hydro Technologies (OHT) had shown that small cryogenic columns could be stably controlled and designed to much lower inventories than had been previously thought possible. Among the results were measurements of Height-of-Equivalent-Theoretical-Plate (HETP) versus holdup for Heli-Pak A and B in columns up to 20 mm diameter. ITER cryogenic distillation column designs suggest that the final high-tritium columns could be 30-70 mm diameter. The objective of this ITER task was to design and construct a column section for demonstration of scale-up of low inventory cryogenic distillation. The experiments were to be carried out in an upgraded Cryogenics Distillation Laboratory at OHT, in the facility used for previous low-inventory column tests. The ITER scaled-up test system as the following characteristics: 55 W condenser capacity; 30 mm diameter column loaded with Helipak B; 1500 mm packed height. The first task was to design and build the scaled-up test facility. In order to reduce costs, it was necessary to use existing 30-35 W helium refrigerators. Therefore, to provide 60-W duty to the scaled-up column, the two refrigerators had to be well coupled thermally, but not mechanically, since the refrigerator cold heads have very thin shells. The solution was to attach the column firmly to one cold head and indirectly to an adjacent cold head through flexible copper braid. Several iterations were required to obtain the desired good heat transfer with flexible mechanical connection. This facility is now operational and ready to begin measurements on the 30 mm column. Also during 1994, the Princeton Tritium Processing System (TPS) was installed and commissioned. The results from this experience are relevant to the ITER distillation system. 2 refs., 10 figs

  5. Effects of Drake Passage on the Ocean's Thermal and Mechanical Energy Budget in a Coupled AOGCM

    Science.gov (United States)

    von der Heydt, A. S.; Viebahn, J. P.

    2016-12-01

    During the Cenozoic Earth's climate has undergone a major long-term transition from `greenhouse' to `icehouse' conditions with extensive ice sheets in the polar regions of both hemispheres. The gradual cooling may be seen as response to the overall slowly decreasing atmospheric CO2-concentration due to weathering processes in the Earth System, however, continental geometry has changed considerably over this period and the long-term gradual trend was interrupted, by several rapid transitions and periods where temperature and greenhouse gas concentrations seem to be decoupled. The Eocene-Oligocene boundary ( 34 Ma, E/O) and mid-Miocene climatic transition ( 13 Ma, MCT) reflect major phases of Antarctic ice sheet build-up and global climate cooling, while Northern Hemisphere ice sheets developed much later ( 2.7Ma). Thresholds in atmospheric CO2-concentration together with feedback mechanisms related to land ice formation are among the favoured mechanisms of these climatic transitions, while the long-proposed ocean circulation changes caused by opening of tectonic gateways seem to play a less direct role. The opening of the Southern Ocean gateways, however, has eventually led to the development of today's strongest ocean current, the Antarctic Circumpolar Current, playing a major role in the transport properties of the global ocean circulation. The overall state of the global ocean circulation, therefore, must precondition the climate system to dramatic events such as major ice sheet formation. Closing Drake Passage in ocean-only and coupled climate models under otherwise present-day boundary conditions has become a classic experiment, indicating that there exists a considerable uncertainty in the climate response of those models to a closed Drake Passage. Here we quantify the climate response to a closed Drake Passage in a state-of-the-art coupled climate model (CESM). We show that the ocean gateway mechanism is robust in the sense that the equatorward expansion of

  6. Hydrodynamic Instability and Thermal Coupling in a Dynamic Model of Liquid-Propellant Combustion

    Science.gov (United States)

    Margolis, S. B.

    1999-01-01

    For liquid-propellant combustion, the Landau/Levich hydrodynamic models have been combined and extended to account for a dynamic dependence of the burning rate on the local pressure and temperature fields. Analysis of these extended models is greatly facilitated by exploiting the realistic smallness of the gas-to-liquid density ratio rho. Neglecting thermal coupling effects, an asymptotic expression was then derived for the cellular stability boundary A(sub p)(k) where A(sub p) is the pressure sensitivity of the burning rate and k is the disturbance wavenumber. The results explicitly indicate the stabilizing effects of gravity on long-wave disturbances, and those of viscosity and surface tension on short-wave perturbations, and the instability associated with intermediate wavenumbers for critical negative values of A(sub p). In the limit of weak gravity, hydrodynamic instability in liquid-propellant combustion becomes a long-wave, instability phenomenon, whereas at normal gravity, this instability is first manifested through O(1) wavenumbers. In addition, surface tension and viscosity (both liquid and gas) each produce comparable effects in the large-wavenumber regime, thereby providing important modifications to the previous analyses in which one or more of these effects was neglected. For A(sub p)= O, the Landau/Levich results are recovered in appropriate limiting cases, although this typically corresponds to a hydrodynamically unstable parameter regime for p temperature sensitivity is incorporated into our previous asymptotic analyses. This entails a coupling of the energy equation to the previous purely hydrodynamic problem, and leads to a significant modification of the pulsating boundary such that, for sufficiently large values of the temperature-sensitivity parameter, liquid-propellant combustion can become intrinsically unstable to this alternative form of hydrodynamic instability. For simplicity, further attention is confined here to the inviscid version

  7. INFLATING AND DEFLATING HOT JUPITERS: COUPLED TIDAL AND THERMAL EVOLUTION OF KNOWN TRANSITING PLANETS

    International Nuclear Information System (INIS)

    Miller, N.; Fortney, J. J.; Jackson, B.

    2009-01-01

    We examine the radius evolution of close in giant planets with a planet evolution model that couples the orbital-tidal and thermal evolution. For 45 transiting systems, we compute a large grid of cooling/contraction paths forward in time, starting from a large phase space of initial semimajor axes and eccentricities. Given observational constraints at the current time for a given planet (semimajor axis, eccentricity, and system age), we find possible evolutionary paths that match these constraints, and compare the calculated radii to observations. We find that tidal evolution has two effects. First, planets start their evolution at larger semimajor axis, allowing them to contract more efficiently at earlier times. Second, tidal heating can significantly inflate the radius when the orbit is being circularized, but this effect on the radius is short-lived thereafter. Often circularization of the orbit is proceeded by a long period while the semimajor axis slowly decreases. Some systems with previously unexplained large radii that we can reproduce with our coupled model are HAT-P-7, HAT-P-9, WASP-10, and XO-4. This increases the number of planets for which we can match the radius from 24 (of 45) to as many as 35 for our standard case, but for some of these systems we are required to be viewing them at a special time around the era of current radius inflation. This is a concern for the viability of tidal inflation as a general mechanism to explain most inflated radii. Also, large initial eccentricities would have to be common. We also investigate the evolution of models that have a floor on the eccentricity, as may be due to a perturber. In this scenario, we match the extremely large radius of WASP-12b. This work may cast some doubt on our ability to accurately determine the interior heavy element enrichment of normal, noninflated close in planets, because of our dearth of knowledge about these planets' previous orbital-tidal histories. Finally, we find that the end

  8. Exchange coupling mechanism for magnetization reversal and thermal stability of Co nanoparticles embedded in a CoO matrix

    International Nuclear Information System (INIS)

    Givord, Dominique; Skumryev, Vassil; Nogues, Josep

    2005-01-01

    A model providing a semi-quantitative account of the magnetic behavior of Co nanoparticles embedded in a CoO matrix is presented. The results confirm that exchange coupling at the interface between ferromagnetic (FM) and antiferromagnetic (AFM) nanostructures could provide an extra source of magnetic anisotropy, leading to thermal stability of the FM nanoparticles. It is shown that perpendicular coupling between the AFM and FM moments may result in large coercivities. The energy barrier, which works against reversal is due to the AFM susceptibility anisotropy. The experimentally observed exchange bias is tentatively ascribed to pre-existing intrinsic canting of the AFM moments at the interface

  9. Amine modification of thermally carbonized porous silicon with silane coupling chemistry.

    Science.gov (United States)

    Mäkilä, Ermei; Bimbo, Luis M; Kaasalainen, Martti; Herranz, Barbara; Airaksinen, Anu J; Heinonen, Markku; Kukk, Edwin; Hirvonen, Jouni; Santos, Hélder A; Salonen, Jarno

    2012-10-02

    Thermally carbonized porous silicon (TCPSi) microparticles were chemically modified with organofunctional alkoxysilane molecules using a silanization process. Before the silane coupling, the TCPSi surface was activated by immersion in hydrofluoric acid (HF). Instead of regeneration of the silicon hydride species, the HF immersion of silicon carbide structure forms a silanol termination (Si-OH) on the surface required for silanization. Subsequent functionalization with 3-aminopropyltriethoxysilane provides the surface with an amine (-NH(2)) termination, while the SiC-type layer significantly stabilizes the functionalized structure both mechanically and chemically. The presence of terminal amine groups was verified with FTIR, XPS, CHN analysis, and electrophoretic mobility measurements. The overall effects of the silanization to the morphological properties of the initial TCPSi were analyzed and they were found to be very limited, making the treatment effects highly predictable. The maximum obtained number of amine groups on the surface was calculated to be 1.6 groups/nm(2), corresponding to 79% surface coverage. The availability of the amine groups for further biofunctionalization was confirmed by successful biotinylation. The isoelectric point (IEP) of amine-terminated TCPSi was measured to be at pH 7.7, as opposed to pH 2.6 for untreated TCPSi. The effects of the surface amine termination on the cell viability of Caco-2 and HT-29 cells and on the in vitro fenofibrate release profiles were also assessed. The results indicated that the surface modification did not alter the loading of the drug inside the pores and also retained the beneficial enhanced dissolution characteristics similar to TCPSi. Cellular viability studies also showed that the surface modification had only a limited effect on the biocompatibility of the PSi.

  10. Exergy analysis of methane cracking thermally coupled with chemical looping combustion for hydrogen production

    International Nuclear Information System (INIS)

    Wang, Zhe; Fan, Weiyu; Zhang, Guangqing; Dong, Shuang

    2016-01-01

    Highlights: • A novel MC–CLC process for H 2 production is proposed. • Energy utilisation of three MC processes is analysed by exergy analysis. • MC–CLC has the highest exergy efficiency compared with MC-CH 4 and MC-H 2. • MC-H 2 provides an advantage of absence of CO 2 generation. - Abstract: This paper proposes a novel hydrogen production process by Methane Cracking thermally coupled with Chemical Looping Combustion (MC–CLC) which provides an advantage of inherent capture of CO 2 . The energy utilisation performance of the MC–CLC process is compared with that of conventional Methane Cracking with combusting CH 4 (MC-CH 4 ) and Methane Cracking with combusting H 2 (MC-H 2 ) using exergy analysis, with focus on exergy flows, destruction and efficiency. The three MC processes are simulated using Aspen Plus software with detailed heat integration. In these processes, the majority of the exergy destruction occurs in the combustors or CLC mostly due to the high irreversibility of combustion. The CO 2 capture unit has the lowest exergy efficiency in the MC-CH 4 process, leading to a lower overall exergy efficiency of the process. The combustor in the MC-H 2 process has a much higher energy efficiency than that in the MC-CH 4 process or the CLC in the MC–CLC process. Although the use of H 2 as fuel decreases the H 2 production rate, the MC-H 2 process provides the advantage of an absence of CO 2 generation, and stores more chemical exergy in the solid carbon which can be utilised appropriately. The MC–CLC process obtains the highest exergy efficiency among the three models and this is primarily due to the absence of a CO 2 capture penalty and the CLC’s higher fuel utilization efficiency than the conventional combustion process.

  11. Interface requirements to couple thermal-hydraulic codes to 3D neutronic codes

    Energy Technology Data Exchange (ETDEWEB)

    Langenbuch, S.; Austregesilo, H.; Velkov, K. [GRS, Garching (Germany)] [and others

    1997-07-01

    The present situation of thermalhydraulics codes and 3D neutronics codes is briefly described and general considerations for coupling of these codes are discussed. Two different basic approaches of coupling are identified and their relative advantages and disadvantages are discussed. The implementation of the coupling for 3D neutronics codes in the system ATHLET is presented. Meanwhile, this interface is used for coupling three different 3D neutronics codes.

  12. Flow resistance of orifices and spacers of BWR thermal-hydraulic and neutronic coupling loop

    International Nuclear Information System (INIS)

    Iguchi, Tadashi; Asaka, Hideaki; Nakamura, Hideo

    2002-03-01

    Authors are performing THYNC experiments to study thermal-hydraulic instability under neutronic and thermal-hydraulic coupling. In THYNC experiments, the orifices are installed at the exit of the test section and the spacers are installed in the test section, in order to properly simulate in-core thermal-hydraulics in the reactor core. It is necessary to know the flow resistance of the orifices and spacers for the analysis of THYNC experimental results. Consequently, authors measured the flow resistance of orifice and spacer under single-phase and two-phase flows. Using the experimental results, authors investigated the dependency of the flow resistances on the parameters, such as pressure, mass flux, an geometries. Furthermore, authors investigated the applicability of the basic two-phase flow models, for example the separate flow model, to the two-phase flow multiplier. As the result of the investigation on the single-phase flow experiment, it was found (1) that the effects of pressure and mass flux flow resistance are described by a function of Reynolds number, and (2) that flow resistances of the orifice and the spacer are calculated with the previous prediction methods. However, it was necessary to introduce an empirical coefficient, since it was difficult to predict accurately the flow resistance only with the previous prediction method due to the complicated geometry dependency, for example a flow area blockage ratio. On the other hand, according to the investigation on two-phase flow experiment, the followings were found. (1) Relation between the two-phase flow multiplier and the quality is regarded to be linear under pressure of 2MPa - 7MPa. The relation is dependent on pressure and geometry, and is little dependent on mass flux. (2) Relation between the two-phase flow multiplier and void fraction is little dependent on pressure, mass flux, and geometry under pressure of 0.2MPa - 7MPa and void fraction less than 0.6. The relation is less dependent on

  13. Modeling coupled thermal, flow, transport and geochemical processes controlling near field long-term evolution

    International Nuclear Information System (INIS)

    Zhou, W.; Arthur, R.; Xu, T.; Pruess, K.

    2005-01-01

    Full text of publication follows: Bentonite is planned for use as a buffer material in the Swedish nuclear waste disposal concept (KBS-3). Upon emplacement, the buffer is expected to experience a complex set of coupled processes involving heating, re-saturation, reaction and transport of groundwater imbibed from the host rock. The effect of these processes may eventually lead to changes in desirable physical and rheological properties of the buffer, but these processes are not well understood. In this paper, a new quantitative model is evaluated to help improve our understanding of the long-term performance of buffer materials. This is an extension of a previous study [1] that involved simple thermal and chemical models applied to a fully saturated buffer. The thermal model in the present study uses heating histories for spent fuel in a single waste package [2]. The model uses repository dimensions, such as borehole and tunnel spacings [2], which affect the temperature distribution around the waste package. At the time of emplacement, bentonite is partially saturated with water having a different composition than the host-rock groundwater. The present model simulates water imbibition from the host rock into the bentonite under capillary and hydraulic pressure gradients. The associated chemical reactions and solute transport are simulated using Aespoe water composition [3]. The initial mineralogy of bentonite is assumed to be dominated by Na-smectite with much smaller amounts of anhydrite and calcite. Na-smectite dissolution is assumed to be kinetically-controlled while all other reactions are assumed to be at equilibrium controlled. All equilibrium and kinetic constants are temperature dependent. The modeling tool used is TOUGHREACT, developed by Lawrence Berkeley National Laboratory [4]. TOUGHREACT is a numerical model that is well suited for near-field simulations because it accounts for feedback between porosity and permeability changes from mineral

  14. Distillation Column Flooding Predictor

    Energy Technology Data Exchange (ETDEWEB)

    George E. Dzyacky

    2010-11-23

    The Flooding Predictor™ is a patented advanced control technology proven in research at the Separations Research Program, University of Texas at Austin, to increase distillation column throughput by over 6%, while also increasing energy efficiency by 10%. The research was conducted under a U. S. Department of Energy Cooperative Agreement awarded to George Dzyacky of 2ndpoint, LLC. The Flooding Predictor™ works by detecting the incipient flood point and controlling the column closer to its actual hydraulic limit than historical practices have allowed. Further, the technology uses existing column instrumentation, meaning no additional refining infrastructure is required. Refiners often push distillation columns to maximize throughput, improve separation, or simply to achieve day-to-day optimization. Attempting to achieve such operating objectives is a tricky undertaking that can result in flooding. Operators and advanced control strategies alike rely on the conventional use of delta-pressure instrumentation to approximate the column’s approach to flood. But column delta-pressure is more an inference of the column’s approach to flood than it is an actual measurement of it. As a consequence, delta pressure limits are established conservatively in order to operate in a regime where the column is never expected to flood. As a result, there is much “left on the table” when operating in such a regime, i.e. the capacity difference between controlling the column to an upper delta-pressure limit and controlling it to the actual hydraulic limit. The Flooding Predictor™, an innovative pattern recognition technology, controls columns at their actual hydraulic limit, which research shows leads to a throughput increase of over 6%. Controlling closer to the hydraulic limit also permits operation in a sweet spot of increased energy-efficiency. In this region of increased column loading, the Flooding Predictor is able to exploit the benefits of higher liquid

  15. Quantum entanglement distillation with metamaterials.

    Science.gov (United States)

    al Farooqui, Md Abdullah; Breeland, Justin; Aslam, Muhammad I; Sadatgol, Mehdi; Özdemir, Şahin K; Tame, Mark; Yang, Lan; Güney, Durdu Ö

    2015-07-13

    We propose a scheme for the distillation of partially entangled two-photon Bell and three-photon W states using metamaterials. The distillation of partially entangled Bell states is achieved by using two metamaterials with polarization dependence, one of which is rotated by π/2 around the direction of propagation of the photons. On the other hand, the distillation of three-photon W states is achieved by using one polarization dependent metamaterial and two polarization independent metamaterials. Upon transmission of the photons of the partially entangled states through the metamaterials the entanglement of the states increases and they become distilled. This work opens up new directions in quantum optical state engineering by showing how metamaterials can be used to carry out a quantum information processing task.

  16. A coupled thermal and electrochemical study of lithium-ion battery cooled by paraffin/porous-graphite-matrix composite

    OpenAIRE

    Greco, Angelo; Jiang, Xi

    2016-01-01

    Lithium-ion (Li-ion) battery cooling using a phase change material (PCM)/compressed expanded natural graphite (CENG) composite is investigated, for a cylindrical battery cell and for a battery module scale. An electrochemistry model (average model) is coupled to the thermal model, with the addition of a one-dimensional model for the solution and solid diffusion using the nodal network method. The analysis of the temperature distribution of the battery module scale has shown that a two-dimensi...

  17. Membrane distillation : a new approach using composite membranes

    NARCIS (Netherlands)

    Franken, Antonius Christianus Maria

    1988-01-01

    In this thesis several aspects of the membrane distillation process and the thermally driven pervaporation process have been described. Both processes differ essentially from each other as far as their mechanism of separation and their applicability is concerned. From a practical point of view,

  18. Effective Thermal Property Estimation of Unitary Pebble Beds Based on a CFD-DEM Coupled Method for a Fusion Blanket

    Science.gov (United States)

    Chen, Lei; Chen, Youhua; Huang, Kai; Liu, Songlin

    2015-12-01

    Lithium ceramic pebble beds have been considered in the solid blanket design for fusion reactors. To characterize the fusion solid blanket thermal performance, studies of the effective thermal properties, i.e. the effective thermal conductivity and heat transfer coefficient, of the pebble beds are necessary. In this paper, a 3D computational fluid dynamics discrete element method (CFD-DEM) coupled numerical model was proposed to simulate heat transfer and thereby estimate the effective thermal properties. The DEM was applied to produce a geometric topology of a prototypical blanket pebble bed by directly simulating the contact state of each individual particle using basic interaction laws. Based on this geometric topology, a CFD model was built to analyze the temperature distribution and obtain the effective thermal properties. The current numerical model was shown to be in good agreement with the existing experimental data for effective thermal conductivity available in the literature. supported by National Special Project for Magnetic Confined Nuclear Fusion Energy of China (Nos. 2013GB108004, 2015GB108002, 2014GB122000 and 2014GB119000), and National Natural Science Foundation of China (No. 11175207)

  19. Distillation process using microchannel technology

    Science.gov (United States)

    Tonkovich, Anna Lee [Dublin, OH; Simmons, Wayne W [Dublin, OH; Silva, Laura J [Dublin, OH; Qiu, Dongming [Carbondale, IL; Perry, Steven T [Galloway, OH; Yuschak, Thomas [Dublin, OH; Hickey, Thomas P [Dublin, OH; Arora, Ravi [Dublin, OH; Smith, Amanda [Galloway, OH; Litt, Robert Dwayne [Westerville, OH; Neagle, Paul [Westerville, OH

    2009-11-03

    The disclosed invention relates to a distillation process for separating two or more components having different volatilities from a liquid mixture containing the components. The process employs microchannel technology for effecting the distillation and is particularly suitable for conducting difficult separations, such as the separation of ethane from ethylene, wherein the individual components are characterized by having volatilities that are very close to one another.

  20. Parametric studies by means of uncertainty and sensitivity methods for coupled thermal-hydraulic/neutron-physics application

    Energy Technology Data Exchange (ETDEWEB)

    Jaeger, W.; Sanchez, V.; Cheng, X. [Karlsruhe Institute of Technology (KIT), Eggenstein-Leopoldshafen (Germany). Inst. for Neutron Physics and Reactor Technology; Monti, L. [Karlsruhe Institute of Technology (KIT), Eggenstein-Leopoldshafen (Germany). Inst. for Nuclear and Energy Technologies; Hurtado, A. [Technical Univ. of Dresden (Germany). Inst. of Power Engineering

    2011-07-01

    At the Institute for Neutron Physics and Reactor Technology (INR) at the Karlsruhe Institute of Technology (KIT), the development and validation of coupled codes systems is one major activity. In this paper, a 2-step method is proposed to perform uncertainty and sensitivity analysis of a nuclear fuel bundle. At first, the SUSA package (Software system for Uncertainty and Sensitivity Analysis), 2 is applied to the thermal hydraulic results of the TRACE (TRACE/RELAP Advanced Computational Engine) code to identify crucial thermal hydraulic parameter combinations which are successively used in the TH/NP coupled system TRACEERANOS to account for the neutronic feedbacks. This 2-step method was applied since the TRACE-ERANOS system runs 1 input in approximately 1 day (depending on the computer configurations). Since the uncertainty and sensitivity analysis requires about 100 runs of the thermal hydraulic input (with altered parameters, running within minutes) an integral TRACE-SUSA-ERANOS analysis would need around 100 days. For this analysis a fuel assembly model of the HPLWR (High Performance Light Water Reactor) was selected. Due to the general structure of the coupling and code communication scripts, the system can be used for any kind of reactor/system which can be described with TRACE and ERANOS (e.g., fast systems) while SUSA can be applied to anything. (orig.)

  1. Thermal-orbital coupled tidal heating and habitability of Martian-sized extrasolar planets around M stars

    International Nuclear Information System (INIS)

    Shoji, D.; Kurita, K.

    2014-01-01

    M-type stars are good targets in the search for habitable extrasolar planets. Due to their low effective temperatures, the habitable zone of M stars is very close to the stars themselves. For planets that are close to their stars, tidal heating plays an important role in thermal and orbital evolutions, especially when the planet's orbit has a relatively large eccentricity. Although tidal heating interacts with the thermal state and the orbit of the planet, such coupled calculations for extrasolar planets around M stars have not been conducted. We perform coupled calculations using simple structural and orbital models and analyze the thermal state and habitability of a terrestrial planet. Considering this planet to be Martian-sized, the tide heats up and partially melts the mantle, maintaining an equilibrium state if the mass of the star is less than 0.2 times the mass of the Sun and the initial eccentricity of the orbit is more than 0.2. The reduction of heat dissipation due to the melted mantle allows the planet to stay in the habitable zone for more than 10 Gyr even though the orbital distance is small. The surface heat flux at the equilibrium state is between that of Mars and Io. The thermal state of the planet mainly depends on the initial value of the eccentricity and the mass of the star.

  2. Technological and energetic improvement of a propylene distillation column

    Directory of Open Access Journals (Sweden)

    Ostrovski Nikolaj

    2005-01-01

    Full Text Available A multicomponent distillation column for propylene purification was optimized in order to increase its energetic effectively. The ©-method coupled with the Soave-Redlich-Kwong equation of state for generating K-values and enthalpies was used. The optimal combination of pressure, temperature and reflux flow provided the decrease of steam consumption and loss of propylene with bottom flow.

  3. Minimum Energy Requirements in Complex Distillation Arrangements

    Energy Technology Data Exchange (ETDEWEB)

    Halvorsen, Ivar J.

    2001-07-01

    Distillation is the most widely used industrial separation technology and distillation units are responsible for a significant part of the total heat consumption in the world's process industry. In this work we focus on directly (fully thermally) coupled column arrangements for separation of multicomponent mixtures. These systems are also denoted Petlyuk arrangements, where a particular implementation is the dividing wall column. Energy savings in the range of 20-40% have been reported with ternary feed mixtures. In addition to energy savings, such integrated units have also a potential for reduced capital cost, making them extra attractive. However, the industrial use has been limited, and difficulties in design and control have been reported as the main reasons. Minimum energy results have only been available for ternary feed mixtures and sharp product splits. This motivates further research in this area, and this thesis will hopefully give some contributions to better understanding of complex column systems. In the first part we derive the general analytic solution for minimum energy consumption in directly coupled columns for a multicomponent feed and any number of products. To our knowledge, this is a new contribution in the field. The basic assumptions are constant relative volatility, constant pressure and constant molar flows and the derivation is based on Underwood's classical methods. An important conclusion is that the minimum energy consumption in a complex directly integrated multi-product arrangement is the same as for the most difficult split between any pair of the specified products when we consider the performance of a conventional two-product column. We also present the Vmin-diagram, which is a simple graphical tool for visualisation of minimum energy related to feed distribution. The Vmin-diagram provides a simple mean to assess the detailed flow requirements for all parts of a complex directly coupled arrangement. The main purpose in

  4. Desalination using Membrane Distillation : Experimental and Numerical Study

    OpenAIRE

    Kullab, Alaa

    2011-01-01

    Desalination has been increasingly adopted over the last decades as an option, and sometimes as a necessity to overcome water shortages in many areas around the world. Today, several thermal and physical separation technologies are well established in large scale production for domestic and industrial purposes.  Membrane distillation is a novel thermally-driven process that can be adapted effectively for water desalination or water treatment in industrial applications, due to its potential lo...

  5. 27 CFR 24.216 - Distilling material.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Distilling material. 24.216 Section 24.216 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU... fermentation or distillation. No sugar may be added in the production of distilling material. Distillates...

  6. Use of solar distillation for olive mill wastewater drying and recovery of polyphenolic compounds.

    Science.gov (United States)

    Sklavos, Sotirios; Gatidou, Georgia; Stasinakis, Athanasios S; Haralambopoulos, Dias

    2015-10-01

    Olive mill wastewater (OMW) is characterized by its high organic load and the presence of phenolic compounds. For first time, a solar distillator was used to investigate the simultaneous solar drying of OMW and the recovery of phenolic compounds with antioxidant properties in the distillate. Two experiments were conducted and the role of thermal insulation on the performance of the distiller was studied. The use of insulation resulted to higher temperatures in the distillator (up to 84.3 °C and 78.5 °C at the air and sludge, respectively), shorter period for OMW dewatering (14 days), while it increased the performance of distillator by 26.1%. Chemical characterization of the distillate showed that pH and COD concentration gradually decreased during the experiments, whereas an opposite trend was noticed for conductivity and total phenols concentration. Almost 4% of the total phenols found initially in OMW were transferred to the distillate when an insulated solar distillator was used. Gas chromatographic analysis of collected distillates confirmed the presence of tyrosol in all samples; whereas hydroxytyrosol was found only in fresh collected distillate samples. Further experiments should be conducted to optimize the process and quantify the concentrations of recovered phenolic compounds. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. Results From an International Simulation Study on Coupled Thermal, Hydrological, and Mechanical (THM) Processes Near Geological Nuclear Waste Repositories

    International Nuclear Information System (INIS)

    J. Rutqvist; D. Barr; J.T. Birkholzer; M. Chijimatsu; O. Kolditz; Q. Liu; Y. Oda; W. Wang; C. Zhang

    2006-01-01

    As part of the ongoing international DECOVALEX project, four research teams used five different models to simulate coupled thermal, hydrological, and mechanical (THM) processes near waste emplacement drifts of geological nuclear waste repositories. The simulations were conducted for two generic repository types, one with open and the other with back-filled repository drifts, under higher and lower postclosure temperatures, respectively. In the completed first model inception phase of the project, a good agreement was achieved between the research teams in calculating THM responses for both repository types, although some disagreement in hydrological responses is currently being resolved. In particular, good agreement in the basic thermal-mechanical responses was achieved for both repository types, even though some teams used relatively simplified thermal-elastic heat-conduction models that neglected complex near-field thermal-hydrological processes. The good agreement between the complex and simplified process models indicates that the basic thermal-mechanical responses can be predicted with a relatively high confidence level

  8. Performance and costs of a roof-sized PV/thermal array combined with a ground coupled heat pump

    International Nuclear Information System (INIS)

    Bakker, M.; Zondag, H.A.; Elswijk, M.J.; Strootman, K.J.; Jong, M.J.M.

    2005-01-01

    A photovoltaic/thermal (PVT) panel is a combination of photovoltaic cells with a solar thermal collector, generating solar electricity and solar heat simultaneously. Hence, PVT panels are an alternative for a combination of separate PV panels and solar thermal collectors. A promising system concept, consisting of 25 m 2 of PVT panels and a ground coupled heat pump, has been simulated in TRNSYS. It has been found that this system is able to cover 100% of the total heat demand for a typical newly-built Dutch one-family dwelling, while covering nearly all of its own electricity use and keeping the long-term average ground temperature constant. The cost of such a system has been compared to the cost of a reference system, where the PVT panels have been replaced with separate PV panels (26 m 2 ) and solar thermal collectors (7 m 2 ), but which is otherwise identical. The electrical and thermal yield of this reference system is equal to that of the PVT system. It has been found that both systems require a nearly identical initial investment. Finally, a view on future PVT markets is given. In general, the residential market is by far the most promising market. The system discussed in this paper is expected to be most successful in newly-built low-energy housing concepts. (Author)

  9. The thermal fatigue resistance of vermicular cast iron coupling with H13 steel units by cast-in process

    International Nuclear Information System (INIS)

    Wang, Chengtao; Zhou, Hong; Lin, Peng Yu; Sun, Na; Guo, Qingchun; Zhang, Peng; Yu, Jiaxiang; Liu, Yan; Wang, Mingxing; Ren, Luquan

    2010-01-01

    This paper focuses on improving the thermal fatigue resistance on the surface of vermicular cast iron coupling with inserted H13 steel blocks that had different cross sections, by cast-in processing. The microstructure of bionic units was examined by scanning electron microscope. Micro-hardness and thermal fatigue resistance of bionic samples with varied cross sections and spacings were investigated, respectively. Results show that a marked metallurgical bonding zone was produced at interface between the inserted H13 steel block and the parent material - a unique feature of the bionic structure in the vermicular cast iron samples. The micro-hardness of the bionic samples has been significantly improved. Thermal resistance of the samples with the circular cross section was the highest and the bionics sample with spacing of 2 mm spacing had a much longer thermal fatigue life, thus resulting in the improvement for the thermal fatigue life of the bionic samples, due to the efficient preclusion for the generation and propagation of crack at the interface of H13 block and the matrix.

  10. Performance and costs of a roof-sized PV/thermal array combined with a ground coupled heat pump

    International Nuclear Information System (INIS)

    Bakker, M.; Zondag, H.A.; Elswijk, M.J.; Strootman, K.J.; Jong, M.J.M.

    2005-03-01

    A photovoltaic/thermal (PVT) panel is a combination of photovoltaic cells with a solar thermal collector, generating solar electricity and solar heat simultaneously. Hence, PVT panels are an alternative for a combination of separate PV panels and solar thermal collectors. A promising system concept, consisting of 25 m 2 of PVT panels and a ground coupled heat pump, has been simulated in TRNSYS. It has been found that this system is able to cover 100% of the total heat demand for a typical newly-built Dutch one-family dwelling, while covering nearly all of its own electricity use and keeping the long-term average ground temperature constant. The cost of such a system has been compared to the cost of a reference system, where the PVT panels have been replaced with separate PV panels (26 m 2 ) and solar thermal collectors (7 m 2 ), but which is otherwise identical. The electrical and thermal yield of this reference system is equal to that of the PVT system. It has been found that both systems require a nearly identical initial investment. Finally, a view on future PVT markets is given. In general, the residential market is by far the most promising market. The system discussed in this paper is expected to be most successful in newly-built low-energy housing concepts

  11. Solar membrane distillation: desalination for the Navajo Nation.

    Science.gov (United States)

    Karanikola, Vasiliki; Corral, Andrea F; Mette, Patrick; Jiang, Hua; Arnoldand, Robert G; Ela, Wendell P

    2014-01-01

    Provision of clean water is among the most serious, long-term challenges in the world. To an ever increasing degree, sustainable water supply depends on the utilization of water of impaired initial quality. This is particularly true in developing nations and in water-stressed areas such as the American Southwest. One clear example is the Navajo Nation. The reservation covers 27,000 square miles, mainly in northeastern Arizona. Low population density coupled with water scarcity and impairment makes provision of clean water particularly challenging. The Navajos rely primarily on ground water, which is often present in deep aquifers or of brackish quality. Commonly, reverse osmosis (RO) is chosen to desalinate brackish ground water, since RO costs are competitive with those of thermal desalination, even for seawater applications. However, both conventional thermal distillation and RO are energy intensive, complex processes that discourage decentralized or rural implementation. In addition, both technologies demand technical experience for operation and maintenance, and are susceptible to scaling and fouling unless extensive feed pretreatment is employed. Membrane distillation (MD), driven by vapor pressure gradients, can potentially overcome many of these drawbacks. MD can operate using low-grade, sub-boiling sources of heat and does not require extensive operational experience. This presentation discusses a project on the Navajo Nation, Arizona (Native American tribal lands) that is designed to investigate and deploy an autonomous (off-grid) system to pump and treat brackish groundwater using solar energy. Βench-scale, hollow fiber MD experiment results showed permeate water fluxes from 21 L/m2·d can be achieved with transmembrane temperature differences between 40 and 80˚C. Tests run with various feed salt concentrations indicate that the permeate flux decreases only about 25% as the concentration increases from 0 to 14% (w/w), which is four times seawater salt

  12. Coupled Monitoring and Inverse Modeling to Investigate Surface - Subsurface Hydrological and Thermal Dynamics in the Arctic Tundra

    Science.gov (United States)

    Tran, A. P.; Dafflon, B.; Hubbard, S. S.; Bisht, G.; Peterson, J.; Ulrich, C.; Romanovsky, V. E.; Kneafsey, T. J.; Wu, Y.

    2015-12-01

    Quantitative characterization of the soil surface-subsurface hydrological and thermal processes is essential as they are primary factors that control the biogeochemical processes, ecological landscapes and greenhouse gas fluxes. In the Artic region, the surface-subsurface hydrological and thermal regimes co-interact and are both largely influenced by soil texture and soil organic content. In this study, we present a coupled inversion scheme that jointly inverts hydrological, thermal and geophysical data to estimate the vertical profiles of clay, sand and organic contents. Within this inversion scheme, the Community Land Model (CLM4.5) serves as a forward model to simulate the land-surface energy balance and subsurface hydrological-thermal processes. Soil electrical conductivity (from electrical resistivity tomography), temperature and water content are linked together via petrophysical and geophysical models. Particularly, the inversion scheme accounts for the influences of the soil organic and mineral content on both of the hydrological-thermal dynamics and the petrophysical relationship. We applied the inversion scheme to the Next Generation Ecosystem Experiments (NGEE) intensive site in Barrow, AK, which is characterized by polygonal-shaped arctic tundra. The monitoring system autonomously provides a suite of above-ground measurements (e.g., precipitation, air temperature, wind speed, short-long wave radiation, canopy greenness and eddy covariance) as well as below-ground measurements (soil moisture, soil temperature, thaw layer thickness, snow thickness and soil electrical conductivity), which complement other periodic, manually collected measurements. The preliminary results indicate that the model can well reproduce the spatiotemporal dynamics of the soil temperature, and therefore, accurately predict the active layer thickness. The hydrological and thermal dynamics are closely linked to the polygon types and polygon features. The results also enable the

  13. Efficiency of fermionic quantum distillation

    Energy Technology Data Exchange (ETDEWEB)

    Herbrych, Jacek W. [Univ. of Tennessee, Knoxville, TN (United States); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Feiguin, Adrian E. [Northeastern Univ., Boston, MA (United States); Dagotto, Elbio R. [Univ. of Tennessee, Knoxville, TN (United States); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Heidrich-Meisner, F. [Ludwig-Maximilians-Univ. Munchen, Munchen (Germany)

    2017-09-13

    Here, we present a time-dependent density-matrix renormalization group investigation of the quantum distillation process within the Fermi-Hubbard model on a quasi-one-dimensional ladder geometry. The term distillation refers to the dynamical, spatial separation of singlons and doublons in the sudden expansion of interacting particles in an optical lattice, i.e., the release of a cloud of atoms from a trapping potential. Remarkably, quantum distillation can lead to a contraction of the doublon cloud, resulting in an increased density of the doublons in the core region compared to the initial state. As a main result, we show that this phenomenon is not limited to chains that were previously studied. Interestingly, there are additional dynamical processes on the two-leg ladder such as density oscillations and self-trapping of defects that lead to a less efficient distillation process. An investigation of the time evolution starting from product states provides an explanation for this behavior. Initial product states are also considered since in optical lattice experiments, such states are often used as the initial setup. We propose configurations that lead to a fast and efficient quantum distillation.

  14. DECOVALEX III PROJECT. Thermal-Hydro-Mechanical Coupled Processes in Safety Assessments. Report of Task 4

    Energy Technology Data Exchange (ETDEWEB)

    Andersson, Johan [JA Streamflow AB, Aelvsjoe (Sweden)

    2005-02-15

    A part (Task 4) of the International DECOVALEX III project on coupled thermo-hydro-mechanical (T-H-M) processes focuses on T-H-M modelling applications in safety and performance assessment of deep geological nuclear waste repositories. A previous phase, DECOVALEX II, saw a need to improve such modelling. In order to address this need Task 4 of DECOVALEX III has: Analysed two major T-H-M experiments (Task 1 and Task 2) and three different Bench Mark Tests (Task 3) set-up to explore the significance of T-H-M in some potentially important safety assessment applications. Compiled and evaluated the use of T-H-M modelling in safety assessments at the time of the year 2000. Organised a forum a forum of interchange between PA-analysts and THM modelers at each DECOVALEX III workshop. Based on this information the current report discusses the findings and strives for reaching recommendations as regards good practices in addressing coupled T-H-M issues in safety assessments. The full development of T-H-M modelling is still at an early stage and it is not evident whether current codes provide the information that is required. However, although the geosphere is a system of fully coupled processes, this does not directly imply that all existing coupled mechanisms must be represented numerically. Modelling is conducted for specific purposes and the required confidence level should be considered. It is necessary to match the confidence level with the modelling objective. Coupled THM modelling has to incorporate uncertainties. These uncertainties mainly concern uncertainties in the conceptual model and uncertainty in data. Assessing data uncertainty is important when judging the need to model coupled processes. Often data uncertainty is more significant than the coupled effects. The emphasis on the need for THM modelling differs among disciplines. For geological radioactive waste disposal in crystalline and other similar hard rock formations DECOVALEX III shows it is essential to

  15. Near-field coupling of gold plasmonic antennas for sub-100 nm magneto-thermal microscopy

    Directory of Open Access Journals (Sweden)

    Jonathan C. Karsch

    2017-08-01

    Full Text Available The development of spintronic technology with increasingly dense, high-speed, and complex devices will be accelerated by accessible microscopy techniques capable of probing magnetic phenomena on picosecond time scales and at deeply sub-micron length scales. A recently developed time-resolved magneto-thermal microscope provides a path towards this goal if it is augmented with a picosecond, nanoscale heat source. We theoretically study adiabatic nanofocusing and near-field heat induction using conical gold plasmonic antennas to generate sub-100 nm thermal gradients for time-resolved magneto-thermal imaging. Finite element calculations of antenna-sample interactions reveal focused electromagnetic loss profiles that are either peaked directly under the antenna or are annular, depending on the sample’s conductivity, the antenna’s apex radius, and the tip-sample separation. We find that the thermal gradient is confined to 40 nm to 60 nm full width at half maximum for realistic ranges of sample conductivity and apex radius. To mitigate this variation, which is undesirable for microscopy, we investigate the use of a platinum capping layer on top of the sample as a thermal transduction layer to produce heat uniformly across different sample materials. After determining the optimal capping layer thickness, we simulate the evolution of the thermal gradient in the underlying sample layer and find that the temporal width is below 10 ps. These results lay a theoretical foundation for nanoscale, time-resolved magneto-thermal imaging.

  16. A coupled THC model of the FEBEX in situ test with bentonite swelling and chemical and thermal osmosis

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, L.; Samper, J.; Montenegro, L.

    2011-04-01

    The performance assessment of a geological repository for radioactive waste requires quantifying the geochemical evolution of the bentonite engineered barrier. This barrier will be exposed to coupled thermal (T), hydrodynamic (H), mechanical (M) and chemical (C) processes. This paper presents a coupled THC model of the FEBEX (Full-scale Engineered Barrier EXperiment) in situ test which accounts for bentonite swelling and chemical and thermal osmosis. Model results attest the relevance of thermal osmosis and bentonite swelling for the geochemical evolution of the bentonite barrier while chemical osmosis is found to be almost irrelevant. The model has been tested with data collected after the dismantling of heater 1 of the in situ test. The model reproduces reasonably well the measured temperature, relative humidity, water content and inferred geochemical data. However, it fails to mimic the solute concentrations at the heater-bentonite and bentonite-granite interfaces because the model does not account for the volume change of bentonite, the CO{sub 2}(g) degassing and the transport of vapor from the bentonite into the granite. The inferred HCO{sub 3}{sup -} and pH data cannot be explained solely by solute transport, calcite dissolution and protonation/deprotonation by surface complexation, suggesting that such data may be affected also by other reactions.

  17. A coupled THC model of the FEBEX in situ test with bentonite swelling and chemical and thermal osmosis

    International Nuclear Information System (INIS)

    Zheng, L.; Samper, J.; Montenegro, L.

    2011-01-01

    The performance assessment of a geological repository for radioactive waste requires quantifying the geochemical evolution of the bentonite engineered barrier. This barrier will be exposed to coupled thermal (T), hydrodynamic (H), mechanical (M) and chemical (C) processes. This paper presents a coupled THC model of the FEBEX (Full-scale Engineered Barrier EXperiment) in situ test which accounts for bentonite swelling and chemical and thermal osmosis. Model results attest the relevance of thermal osmosis and bentonite swelling for the geochemical evolution of the bentonite barrier while chemical osmosis is found to be almost irrelevant. The model has been tested with data collected after the dismantling of heater 1 of the in situ test. The model reproduces reasonably well the measured temperature, relative humidity, water content and inferred geochemical data. However, it fails to mimic the solute concentrations at the heater-bentonite and bentonite-granite interfaces because the model does not account for the volume change of bentonite, the CO 2 (g) degassing and the transport of vapor from the bentonite into the granite. The inferred HCO 3 - and pH data cannot be explained solely by solute transport, calcite dissolution and protonation/deprotonation by surface complexation, suggesting that such data may be affected also by other reactions.

  18. Thermal hydraulic and neutron kinetic simulation of the Angra 2 reactor using a RELAP5/PARCS coupled model

    Energy Technology Data Exchange (ETDEWEB)

    Reis, Patricia A.L.; Costa, Antonella L.; Hamers, Adolfo R.; Pereira, Claubia; Rodrigues, Thiago D.A.; Mantecon, Javier G.; Veloso, Maria A.F., E-mail: patricialire@yahoo.com.br, E-mail: antonella@nuclear.ufmg.br, E-mail: adolforomerohamers@hotmail.com, E-mail: claubia@nuclear.ufmg.br, E-mail: thiagodanielbh@gmail.com, E-mail: mantecon1987@gmail.com, E-mail: dora@nuclear.ufmg.br [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Departamento de Engenharia Nuclear; Instituto Nacional de Ciencias e Tecnologia de Reatores Nucleares Inovadores (INCT/CNPq), Belo Horizonte (Brazil); Miro, Rafael; Verdu, Gumersindo, E-mail: rmiro@iqn.upv.es, E-mail: gverdu@iqn.upv.es [Universidad Politecnica de Valencia (Spain). Departamento de Ingenieria Quimica y Nuclear

    2015-07-01

    The computational advances observed in the last two decades have been provided direct impact on the researches related to nuclear simulations, which use several types of computer codes, including coupled between them, allowing representing with very accuracy the behavior of nuclear plants. Studies of complex scenarios in nuclear reactors have been improved by the use of thermal-hydraulic (TH) and neutron kinetics (NK) coupled codes. This technique consists in incorporating three-dimensional (3D) neutron modeling of the reactor core into codes, mainly to simulate transients that involve asymmetric core spatial power distributions and strong feedback effects between neutronics and reactor thermal-hydraulics. Therefore, this work presents preliminary results of TH RELAP5 and the NK PARCS calculations applied to model of the Angra 2 reactor. The WIMSD-5B code has been used to generate the macroscopic cross sections used in the NK code. The results obtained are satisfactory and represent important part of the development of this methodology. The next step is to couple the codes. (author)

  19. Mathematical modeling of a multi-stage naphtha reforming process using novel thermally coupled recuperative reactors to enhance aromatic production

    Energy Technology Data Exchange (ETDEWEB)

    Iranshahi, Davood; Bahmanpour, Ali Mohammad; Pourazadi, Ehsan; Rahimpour, Mohammad Reza [Department of Chemical Engineering, School of Chemical and Petroleum Engineering, Shiraz University, P.O. Box 71345, Shiraz (Iran)

    2010-10-15

    In this study, a novel thermally coupled reactor containing the naphtha reforming process in the endothermic side and the hydrogenation of nitrobenzene to aniline in the exothermic side has been investigated. Considering the higher thermal efficiency as well as the smaller size of the reactor, utilizing the recuperative coupled reactor is given priority. In this novel configuration, the first and the second reactor of the conventional naphtha reforming process have been substituted by the recuperative coupled reactors which contain the naphtha reforming reactions in the shell side, and the hydrogenation reaction in the tube side. The achieved results of this simulation have been compared with the results of the conventional fixed-bed naphtha reforming reactors. Acceptable enhancement can be noticed in the performance of the reactors. The production rate of the high octane aromatics and the consumption rate of the paraffins have improved 17% and 72%, respectively. The conversion of the nitrobenzene is acceptable and the effect of the number of the tubes also has been taken into account. However, the performance of the new configuration needs to be tested experimentally over a range of parameters under practical operating conditions. (author)

  20. Performance indicators of bioethanol distillation

    International Nuclear Information System (INIS)

    Marriaga, Nilson

    2009-01-01

    The increase of biofuels demand accelerates the construction of new production plants and technological improvements in the process so the development of versatile tools for evaluating alternatives becomes an undeniable challenge. It was established through heuristic rules, thermodynamic analysis and simulation computer the energy consumption and performance indicators that govern, from fermented mash (ethanol 8.5 % v/v), the distillation of various capacities for bioethanol production: 20, 60, 100 and 150 KLD (kiloliters / day) through Aspen PlusTM simulator. It was found that the distillation demand nearly 30% of heat that would be obtained by burning alcohol fuel produced thus it is necessary the use of raw materials that generate enough biomass to produce the steam required. In addition, correlations were found to allow for easy diameters of distillation columns in terms of production capacity.

  1. Membrane distillation of industrial cooling tower blowdown water

    Directory of Open Access Journals (Sweden)

    N.E. Koeman-Stein

    2016-06-01

    Full Text Available The potential of membrane distillation for desalination of cooling tower blowdown water (CTBD is investigated. Technical feasibility is tested on laboratory and pilot scale using real cooling tower blowdown water from Dow Benelux in Terneuzen (Netherlands. Two types of membranes, polytetrafluorethylene and polyethylene showed good performance regarding distillate quality and fouling behavior. Concentrating CTBD by a factor 4.5 while maintaining a flux of around 2 l/m2*h was possible with a water recovery of 78% available for reuse. Higher concentration factors lead to severe decrease in flux which was caused by scaling. Membrane distillation could use the thermal energy that would otherwise be discharged of in a cooling tower and function as a heat exchanger. This reduces the need for cooling capacity and could lead to a total reduction of 37% water intake for make-up water, as well as reduced energy and chemicals demands and greenhouse gas emissions.

  2. The direct determination of HgS by thermal desorption coupled with atomic absorption spectrometry

    Czech Academy of Sciences Publication Activity Database

    Coufalík, Pavel; Zvěřina, O.; Komárek, J.

    2016-01-01

    Roč. 118, APR (2016), s. 1-5 ISSN 0584-8547 Institutional support: RVO:68081715 Keywords : mercury * HgS * thermal desorption Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 3.241, year: 2016

  3. Solar power water distillation unit

    Science.gov (United States)

    Hameed, Kamran; Muzammil Khan, Muhammad; Shahrukh Ateeq, Ijlal; Omair, Syed Muhammad; Ahmer, Muhammad; Wajid, Abdul

    2013-06-01

    Clean drinking water is the basic necessity for every human being, but about 1.1 billion people in the world lacked proper drinking water. There are many different types of water purification processes such as filtration, reverse osmosis, ultraviolet radiation, carbon absorption, but the most reliable processes are distillation and boiling. Water purification, such as distillation, is especially important in regions where water resources or tap water is not suitable for ingesting without boiling or chemical treatment. In design project It treats the water by combining different methods such as Filtration, Distillation and a technique called concentrated solar power (CSP). Distillation is literally the method seen in nature, whereby: the sun heats the water on the earth's surface, the water is turned into a vapor (evaporation) and rises, leaving contaminants behind, to form clouds. As the upper atmosphere drops in temperature the vapors cool and convert back to water to form water. In this project distillation is achieved by using a parabolic mirror which boils water at high temperature. Filtration is done by sand filter and carbon filter. First sand filter catches the sand particles and the carbon filter which has granules of active carbon is used to remove odor dissolved gases from water. This is the Pre-treatment of water. The filtered water is then collected in a water container at a focus of parabolic mirror where distillation process is done. Another important feature of designed project is the solar tracking of a parabolic mirror which increases the efficiency of a parabolic mirror [1],[2].

  4. Solar power water distillation unit

    International Nuclear Information System (INIS)

    Hameed, Kamran; Khan, Muhammad Muzammil; Ateeq, Ijlal Shahrukh; Omair, Syed Muhammad; Ahmer, Muhammad; Wajid, Abdul

    2013-01-01

    Clean drinking water is the basic necessity for every human being, but about 1.1 billion people in the world lacked proper drinking water. There are many different types of water purification processes such as filtration, reverse osmosis, ultraviolet radiation, carbon absorption, but the most reliable processes are distillation and boiling. Water purification, such as distillation, is especially important in regions where water resources or tap water is not suitable for ingesting without boiling or chemical treatment. In design project It treats the water by combining different methods such as Filtration, Distillation and a technique called concentrated solar power (CSP). Distillation is literally the method seen in nature, whereby: the sun heats the water on the earth's surface, the water is turned into a vapor (evaporation) and rises, leaving contaminants behind, to form clouds. As the upper atmosphere drops in temperature the vapors cool and convert back to water to form water. In this project distillation is achieved by using a parabolic mirror which boils water at high temperature. Filtration is done by sand filter and carbon filter. First sand filter catches the sand particles and the carbon filter which has granules of active carbon is used to remove odor dissolved gases from water. This is the Pre-treatment of water. The filtered water is then collected in a water container at a focus of parabolic mirror where distillation process is done. Another important feature of designed project is the solar tracking of a parabolic mirror which increases the efficiency of a parabolic mirror [1],[2].

  5. Bounds for nonlocality distillation protocols

    International Nuclear Information System (INIS)

    Forster, Manuel

    2011-01-01

    Nonlocality can be quantified by the violation of a Bell inequality. Since this violation may be amplified by local operations, an alternative measure has been proposed--distillable nonlocality. The alternative measure is difficult to calculate exactly due to the double exponential growth of the parameter space. In this paper, we give a way to bound the distillable nonlocality of a resource by the solutions to a related optimization problem. Our upper bounds are exponentially easier to compute than the exact value and are shown to be meaningful in general and tight in some cases.

  6. Coupled optical-thermal-fluid and structural analyses of novel light-trapping tubular panels for concentrating solar power receivers

    Science.gov (United States)

    Ortega, Jesus D.; Christian, Joshua M.; Yellowhair, Julius E.; Ho, Clifford K.

    2015-09-01

    Traditional tubular receivers used in concentrating solar power are formed using tubes connected to manifolds to form panels; which in turn are arranged in cylindrical or rectangular shapes. Previous and current tubular receivers, such as the ones used in Solar One, Solar Two, and most recently the Ivanpah solar plants, have used a black paint coating to increase the solar absorptance of the receiver. However, these coatings degrade over time and must be reapplied, increasing the receiver maintenance cost. This paper presents the thermal efficiency evaluation of novel receiver tubular panels that have a higher effective solar absorptance due to a light-trapping effect created by arranging the tubes in each panel into unique geometric configurations. Similarly, the impact of the incidence angle on the effective solar absorptance and thermal efficiency is evaluated. The overarching goal of this work is to achieve effective solar absorptances of ~90% and thermal efficiencies above 85% without using an absorptance coating. Several panel geometries were initially proposed and were down-selected based on structural analyses considering the thermal and pressure loading requirements of molten salt and supercritical carbon-dioxide receivers. The effective solar absorptance of the chosen tube geometries and panel configurations were evaluated using the ray-tracing modeling capabilities of SolTrace. The thermal efficiency was then evaluated by coupling computational fluid dynamics with the ray-tracing results using ANSYS Fluent. Compared to the base case analysis (flat tubular panel), the novel tubular panels have shown an increase in effective solar absorptance and thermal efficiency by several percentage points.

  7. Interface requirements to couple thermal hydraulics codes to severe accident codes: ICARE/CATHARE

    International Nuclear Information System (INIS)

    Camous, F.; Jacq, F.; Chatelard, P.

    1997-01-01

    In order to describe with the same code the whole sequence of severe LWR accidents, up to the vessel failure, the Institute of Protection and Nuclear Safety has performed a coupling of the severe accident code ICARE2 to the thermalhydraulics code CATHARE2. The resulting code, ICARE/CATHARE, is designed to be as pertinent as possible in all the phases of the accident. This paper is mainly devoted to the description of the ICARE2-CATHARE2 coupling

  8. Interface requirements to couple thermal hydraulics codes to severe accident codes: ICARE/CATHARE

    Energy Technology Data Exchange (ETDEWEB)

    Camous, F.; Jacq, F.; Chatelard, P. [IPSN/DRS/SEMAR CE-Cadarache, St Paul Lez Durance (France)] [and others

    1997-07-01

    In order to describe with the same code the whole sequence of severe LWR accidents, up to the vessel failure, the Institute of Protection and Nuclear Safety has performed a coupling of the severe accident code ICARE2 to the thermalhydraulics code CATHARE2. The resulting code, ICARE/CATHARE, is designed to be as pertinent as possible in all the phases of the accident. This paper is mainly devoted to the description of the ICARE2-CATHARE2 coupling.

  9. A model predictive framework of Ground Source Heat Pump coupled with Aquifer Thermal Energy Storage System in heating and cooling equipment of a building

    NARCIS (Netherlands)

    Rostampour Samarin, V.; Bloemendal, J.M.; Keviczky, T.

    2017-01-01

    This paper presents a complete model of a building heating and cooling equipment and a ground source heat pump (GSHP) coupled with an aquifer thermal energy storage (ATES) system. This model contains detailed
    mathematical representations of building thermal dynamics, ATES system dynamics, heat

  10. Design optimization of an axial-field eddy-current magnetic coupling based on magneto-thermal analytical model

    Directory of Open Access Journals (Sweden)

    Fontchastagner Julien

    2018-03-01

    Full Text Available This paper presents a design optimization of an axial-flux eddy-current magnetic coupling. The design procedure is based on a torque formula derived from a 3D analytical model and a population algorithm method. The main objective of this paper is to determine the best design in terms of magnets volume in order to transmit a torque between two movers, while ensuring a low slip speed and a good efficiency. The torque formula is very accurate and computationally efficient, and is valid for any slip speed values. Nevertheless, in order to solve more realistic problems, and then, take into account the thermal effects on the torque value, a thermal model based on convection heat transfer coefficients is also established and used in the design optimization procedure. Results show the effectiveness of the proposed methodology.

  11. Coupled neutronics/thermal-hydraulics analysis of a high-performance light-water reactor fuel assembly

    Energy Technology Data Exchange (ETDEWEB)

    Waata, C.L.

    2006-07-15

    The use of water at supercritical pressure as coolant and moderator introduces a challenge in the design of a High-Performance Light-Water Reactor (HPLWR) fuel assembly. At supercritical pressure condition (P=25 MPa), the thermal-hydraulics behaviour of water differs strongly from that at sub-critical pressure due to a rapid variation of the thermal-physical properties across the pseudo-critical line. Due of the strong link between the water (moderation) and the neutron spectrum and subsequently the power distribution, a coupling of neutronics and thermal-hydraulics has become a necessity for reactor concepts operating at supercritical pressure condition. The effect of neutron moderation on the local parameters of thermal-hydraulics and vice-verse in a fuel assembly has to be considered for an accurate design analysis. In this study, the Monte Carlo N-Particle code (MCNP) and the sub-channel code STAFAS (Sub-channel Thermal-hydraulics Analysis of a Fuel Assembly under Supercritical conditions) have been coupled for the design analysis of a fuel assembly with supercritical water as coolant and moderator. Both codes are well known for complex geometry modelling. The MCNP code is used for neutronics analyses and for the prediction of power profiles of individual fuel rods. The sub-channel code STAFAS for the thermal-hydraulics analyses takes into account the coolant properties beyond the critical point as well as separate moderator channels. The coupling procedure is realized automatically. MCNP calculates the power distribution in each fuel rod, which is then transferred into STAFAS to obtain the corresponding thermal-hydraulic conditions in each sub-channel. The new thermal-hydraulic conditions are used to generate a new input deck for the next MCNP calculation. This procedure is repeated until a converged state is achieved. The coupled code system was tested on a proposed fuel assembly design of a HPLWR. An under-relaxation was introduced to achieve convergence

  12. Coupled neutronics/thermal-hydraulics analysis of a high-performance light-water reactor fuel assembly

    International Nuclear Information System (INIS)

    Waata, C.L.

    2006-07-01

    The use of water at supercritical pressure as coolant and moderator introduces a challenge in the design of a High-Performance Light-Water Reactor (HPLWR) fuel assembly. At supercritical pressure condition (P=25 MPa), the thermal-hydraulics behaviour of water differs strongly from that at sub-critical pressure due to a rapid variation of the thermal-physical properties across the pseudo-critical line. Due of the strong link between the water (moderation) and the neutron spectrum and subsequently the power distribution, a coupling of neutronics and thermal-hydraulics has become a necessity for reactor concepts operating at supercritical pressure condition. The effect of neutron moderation on the local parameters of thermal-hydraulics and vice-verse in a fuel assembly has to be considered for an accurate design analysis. In this study, the Monte Carlo N-Particle code (MCNP) and the sub-channel code STAFAS (Sub-channel Thermal-hydraulics Analysis of a Fuel Assembly under Supercritical conditions) have been coupled for the design analysis of a fuel assembly with supercritical water as coolant and moderator. Both codes are well known for complex geometry modelling. The MCNP code is used for neutronics analyses and for the prediction of power profiles of individual fuel rods. The sub-channel code STAFAS for the thermal-hydraulics analyses takes into account the coolant properties beyond the critical point as well as separate moderator channels. The coupling procedure is realized automatically. MCNP calculates the power distribution in each fuel rod, which is then transferred into STAFAS to obtain the corresponding thermal-hydraulic conditions in each sub-channel. The new thermal-hydraulic conditions are used to generate a new input deck for the next MCNP calculation. This procedure is repeated until a converged state is achieved. The coupled code system was tested on a proposed fuel assembly design of a HPLWR. An under-relaxation was introduced to achieve convergence

  13. TISKTH-3: a couple neutronics/thermal-hydraulics code for the transient analysis of light water reactors

    International Nuclear Information System (INIS)

    Peng Muzhang; Zhang Quan; Wang Guoli; Zhang Yuman

    1988-01-01

    TISKTH-3 is a coupled neutronics/thermal-hydraulics code for the transient analysis. A 3-dimensional neutron kinetics equation solved by the Nodal Green's Function Method is used for the neutronics model of the code. A homogeneous equilibrium model with a complete boiling curve and two numerical solutions of the implicit and explicit scheme is used for the thermal-hydraulics model of the code. A 2-dimensional heat conduction equation with variable conductivity solved by the method of weighted residuals is used for the fuel rod heat transfer model of the code. TISKTH-3 is able to analyze the fast transient process and complicate accident situations in the core. The initative applications have shown that the stability and convergency in the calculations with the code are satisfactory

  14. Energy consumption maps for quaternary distillation sequences

    DEFF Research Database (Denmark)

    Gomez-Castro, F.I.; Ramírez-Vallejo, N.E.; Segovia-Hernandez, J.G.

    2016-01-01

    be generated for the separation of multicomponent mixtures. This fact is an advantage, since a wide portfolio of alternatives can be used to separate a specific mixture; however, this is also a disadvantage since a lot of alternatives must be explored in order to find the optimal one. The optimal configuration...... of the solutions space. For the separation of ternary mixtures, Tedder and Rudd (1978) presented a composition map for which thermally coupled systems allowed energy savings. However, the scenario is different for quaternary mixtures, since no similar information is available. Therefore, in this work, energy...... consumption data for five feed compositions for a mixture near to ideality are presented. The quaternary sequences studied are: conventional direct (three columns), conventional indirect (three columns), thermally coupled direct (main column and two side rectifiers), and thermally coupled indirect (main...

  15. Thermal degradation assessment of canola and olive oil using ultra-fast gas chromatography coupled with chemometrics.

    Science.gov (United States)

    Majchrzak, Tomasz; Lubinska, Martyna; Różańska, Anna; Dymerski, Tomasz; Gębicki, Jacek; Namieśnik, Jacek

    2017-01-01

    Oil blending is often used to enhance the properties of vegetable oils. The admixture of a more thermally stable oil makes the resulting blend more suitable for use in frying. A new method of quality assessment of vegetable oils used in frying is presented in this paper. In this method, ultra-fast gas chromatography coupled with flame ionization detector and chemometrics is employed. Principal component analysis was used for data processing. The results obtained with this method were compared with the results of the Rancimat test and sensory evaluation. It is demonstrated that the addition of olive oil improves the stability of rapeseed oil, and also changes its flavour and aroma profile. In addition, it was found that ultra-fast GC coupled with chemometrics is an effective tool for the assessment of the quality of edible oils. The proposed method does not require sample preparation, and the total time of analysis is less than 2 min.

  16. Methods and Models for the Coupled Neutronics and Thermal-Hydraulics Analysis of the CROCUS Reactor at EFPL

    OpenAIRE

    Rais, A.; Siefman, D.; Girardin, G.; Hursin, M.; Pautz, A.

    2015-01-01

    In order to analyze the steady state and transient behavior of the CROCUS reactor, several methods and models need to be developed in the areas of reactor physics, thermal-hydraulics, and multiphysics coupling. The long-term objectives of this project are to work towards the development of a modern method for the safety analysis of research reactors and to update the Final Safety Analysis Report of the CROCUS reactor. A first part of the paper deals with generation of a core simulator nuclear...

  17. Development of a coupled neutronic/thermal-hydraulic tool with multi-scale capabilities and applications to HPLWR core analysis

    Energy Technology Data Exchange (ETDEWEB)

    Monti, Lanfranco, E-mail: lanfranco.monti@gmail.co [Karlsruhe Institute of Technology (KIT), Institute for Nuclear and Energy Technologies (IKET), Hermann-von-Helmholtzplatz 1, 76344 Eggenstein-Leopoldshafen (Germany); Starflinger, Joerg, E-mail: joerg.starflinger@ike.uni-stuttgart.d [Universitaet Stuttgart, Institut fuer Kernenergetik und Energiesysteme, Pfaffenwaldring 31, 70569 Stuttgart (Germany); Schulenberg, Thomas, E-mail: schulenberg@kit.ed [Karlsruhe Institute of Technology (KIT), Institute for Nuclear and Energy Technologies (IKET), Hermann-von-Helmholtzplatz 1, 76344 Eggenstein-Leopoldshafen (Germany)

    2011-05-15

    Highlights: Advanced analysis and design techniques for innovative reactors are addressed. Detailed investigation of a 3 pass core design with a multi-physics-scales tool. Coupled 40-group neutron transport/equivalent channels TH core analyses methods. Multi-scale capabilities: from equivalent channels to sub-channel pin-by-pin study. High fidelity approach: reduction of conservatism involved in core simulations. - Abstract: The High Performance Light Water Reactor (HPLWR) is a thermal spectrum nuclear reactor cooled and moderated with light water operated at supercritical pressure. It is an innovative reactor concept, which requires developing and applying advanced analysis tools as described in the paper. The relevant water density reduction associated with the heat-up, together with the multi-pass core design, results in a pronounced coupling between neutronic and thermal-hydraulic analyses, which takes into account the strong natural influence of the in-core distribution of power generation and water properties. The neutron flux gradients within the multi-pass core, together with the pronounced dependence of water properties on the temperature, require to consider a fine spatial resolution in which the individual fuel pins are resolved to provide precise evaluation of the clad temperature, currently considered as one of the crucial design criteria. These goals have been achieved considering an advanced analysis method based on the usage of existing codes which have been coupled with developed interfaces. Initially neutronic and thermal-hydraulic full core calculations have been iterated until a consistent solution is found to determine the steady state full power condition of the HPLWR core. Results of few group neutronic analyses might be less reliable in case of HPLWR 3-pass core than for conventional LWRs because of considerable changes of the neutron spectrum within the core, hence 40 groups transport theory has been preferred to the usual 2 groups

  18. Coupled CFD-Thermal Analysis of Erosion Patterns Resulting from Nozzle Wedgeouts on the SRTMV-N2

    Science.gov (United States)

    Ables, Catherine; Davis, Philip

    2014-01-01

    The objective of this analysis was to study the effects of the erosion patterns from the introduction of nozzle flaws machined into the nozzle of the SRTMV-N2 (Solid Rocket Test Motor V Nozzle 2). The SRTMV-N2 motor was a single segment static subscale solid rocket motor used to further develop the RSRMV (Redesigned Solid Rocket Motor V Segment). Two flaws or "wedgeouts" were placed in the nozzle inlet parallel to the ply angles of that section to study erosion effects. One wedgeout was placed in the nose cap region and the other placed in the inlet ring on the opposite side of the bondline, separated 180 degrees circumferentially. A coupled CFD (Computational Fluid Analysis)-thermal iterative analytical approach was utilized at the wedgeouts to analyze the erosion profile during the burn time. The iterative CFD thermal approach was applied at five second intervals throughout the motor burn. The coupled fluid thermal boundary conditions were derived from a steady state CFD solution at the beginning of the interval. The derived heat fluxes were then applied along the surface and a transient thermal solution was developed to characterize the material response over the specified interval. Eroded profiles of each of the nozzle's wedgeouts and the original contour were created at each of the specified intervals. The final iteration of the erosion profile showed that both wedgeouts were "washedout," indicating that the erosion profile of the wedgeout had rejoined the original eroded contour, leaving no trace of the wedgeouts post fire. This analytical assessment agreed with post-fire observations made of the SRTMV-N2 wedgeouts, which noted a smooth eroded contour.

  19. Development and Applications of a General Coupled Thermal-hydraulic/Neutronic Model for the Ringhals-3 Pressurized Water Reactor

    International Nuclear Information System (INIS)

    Staalek, Mathias

    2008-03-01

    Coupled calculations are important for the simulation of nuclear power plants when there is a strong feedback between the neutron kinetics and the thermal-hydraulics. A general coupled model of the Ringhals-3 Pressurized Water Reactor has been developed for this purpose. The development is outlined in the thesis with details given in the appended papers. A PARCS model was developed for the core calculations and a RELAP5 model for the thermal-hydraulic calculations. The RELAP5 model has 157 channels for modelling the flow in the fuel assemblies. This means that there is a one-one correspondence radially between the neutronic and thermal-hydraulic nodalization. This detailed mapping between the neutron kinetics and the thermal-hydraulics makes it possible to use the model for all kinds of transient. To provide realistic material data to the PARCS model, a cross-section interface was developed. With this interface one can import material data from a binary CASMO-4 library file into PARCS. Due to the one-to-one mapping, any any core loading can easily be considered. The PARCS model was benchmarked against measurements of the steady-state power distribution of Ringhals-3. The power shape was well reproduced by the model. Validational work for steady-state conditions of the thermal-hydraulic was also successfully performed. The most challenging part of the validation of a coupled model is for transients. This is much more difficult since the dynamics of the system becomes very important. Two transients that occurred at Ringhals-3 were chosen for the validational work. The first transient was a Load Rejection Transient. In general the model gave good results but some problems were experienced, e.g. the pressurizer pressure turned out to be more difficult to be correctly simulated. The second transient was a Loss of Feed Water transient. A malfunctioning feed water control valve closed, and therefore shut down the feed water supply to the steam generator in one of the

  20. Experimental investigation on the thermal performance of heat storage walls coupled with active solar systems

    Science.gov (United States)

    Zhao, Chunyu; You, Shijun; Zhu, Chunying; Yu, Wei

    2016-12-01

    This paper presents an experimental investigation of the performance of a system combining a low-temperature water wall radiant heating system and phase change energy storage technology with an active solar system. This system uses a thermal storage wall that is designed with multilayer thermal storage plates. The heat storage material is expanded graphite that absorbs a mixture of capric acid and lauric acid. An experiment is performed to study the actual effect. The following are studied under winter conditions: (1) the temperature of the radiation wall surface, (2) the melting status of the thermal storage material in the internal plate, (3) the density of the heat flux, and (4) the temperature distribution of the indoor space. The results reveal that the room temperature is controlled between 16 and 20 °C, and the thermal storage wall meets the heating and temperature requirements. The following are also studied under summer conditions: (1) the internal relationship between the indoor temperature distribution and the heat transfer within the regenerative plates during the day and (2) the relationship between the outlet air temperature and inlet air temperature in the thermal storage wall in cooling mode at night. The results indicate that the indoor temperature is approximately 27 °C, which satisfies the summer air-conditioning requirements.

  1. Optimization of ITER Nb3Sn CICCs for coupling loss, transverse electromagnetic load and axial thermal contraction

    Science.gov (United States)

    Nijhuis, A.; van Lanen, E. P. A.; Rolando, G.

    2012-01-01

    The ITER cable-in-conduit conductors (CICCs) are built up from sub-cable bundles, wound in different stages, which are twisted to counter coupling loss caused by time-changing external magnet fields. The selection of the twist pitch lengths has major implications for the performance of the cable in the case of strain-sensitive superconductors, i.e. Nb3Sn, as the electromagnetic and thermal contraction loads are large but also for the heat load from the AC coupling loss. At present, this is a great challenge for the ITER central solenoid (CS) CICCs and the solution presented here could be a breakthrough for not only the ITER CS but also for CICC applications in general. After proposing longer twist pitches in 2006 and successful confirmation by short sample tests later on, the ITER toroidal field (TF) conductor cable pattern was improved accordingly. As the restrictions for coupling loss are more demanding for the CS conductors than for the TF conductors, it was believed that longer pitches would not be applicable for the conductors in the CS coils. In this paper we explain how, with the use of the TEMLOP model and the newly developed models JackPot-ACDC and CORD, the design of a CICC can be improved appreciably, particularly for the CS conductor layout. For the first time a large improvement is predicted not only providing very low sensitivity to electromagnetic load and thermal axial cable stress variations but at the same time much lower AC coupling loss. Reduction of the transverse load and warm-up-cool-down degradation can be reached by applying longer twist pitches in a particular sequence for the sub-stages, offering a large cable transverse stiffness, adequate axial flexibility and maximum allowed lateral strand support. Analysis of short sample (TF conductor) data reveals that increasing the twist pitch can lead to a gain of the effective axial compressive strain of more than 0.3% with practically no degradation from bending. This is probably explained by

  2. Electrically Isolating Thermally Coupled Device for Noise Suppression of Circuits in Deep Space

    Science.gov (United States)

    Mantooth, A.; McNutt, T.; Mojarradi, M.; Li, H.; Blalock, B.

    2001-01-01

    Mixed mode rad hard avionics Systems on a Chip (SoC) designed for deep space applications such as Europa orbiters and Europa Landers will require data isolation circuits to block noise. This paper presents the simulation performance for a novel rad hard SOI CMOS compatible thermal transducer used for on-chip data isolation in SoC. The research presented involves the use of commercially available computer aided design tools to model the transient electrothermal behavior of the transducer. Both one- and two-dimensional analyses of a prototype thermal transducer were performed. Results indicate that thermal-based data isolator technology can pass a data bit in under a microsecond and, as a measurement of feasibility, I(exp 2)C bus specifications can be met.

  3. Cooled electronic system with liquid-cooled cold plate and thermal spreader coupled to electronic component

    Energy Technology Data Exchange (ETDEWEB)

    Chainer, Timothy J.; Graybill, David P.; Iyengar, Madhusudan K.; Kamath, Vinod; Kochuparambil, Bejoy J.; Schmidt, Roger R.; Steinke, Mark E.

    2018-03-27

    Apparatus and method are provided for facilitating cooling of an electronic component. The apparatus includes a liquid-cooled cold plate and a thermal spreader associated with the cold plate. The cold plate includes multiple coolant-carrying channel sections extending within the cold plate, and a thermal conduction surface with a larger surface area than a surface area of the component to be cooled. The thermal spreader includes one or more heat pipes including multiple heat pipe sections. One or more heat pipe sections are partially aligned to a first region of the cold plate, that is, where aligned to the surface to be cooled, and partially aligned to a second region of the cold plate, which is outside the first region. The one or more heat pipes facilitate distribution of heat from the electronic component to coolant-carrying channel sections of the cold plate located in the second region of the cold plate.

  4. Prototype of an Interface for Hyphenating Distillation with Gas Chromatography and Mass Spectrometry

    Science.gov (United States)

    Tang, Ya-Ru; Yang, Hui-Hsien; Urban, Pawel L.

    2017-01-01

    Chemical analysis of complex matrices—containing hundreds of compounds—is challenging. Two-dimensional separation techniques provide an efficient way to reduce complexity of mixtures analyzed by mass spectrometry (MS). For example, gasoline is a mixture of numerous compounds, which can be fractionated by distillation techniques. However, coupling conventional distillation with other separations as well as MS is not straightforward. We have established an automatic system for online coupling of simple microscale distillation with gas chromatography (GC) and electron ionization MS. The developed system incorporates an interface between the distillation condenser and the injector of a fused silica capillary GC column. Development of this multidimensional separation (distillation-GC-MS) was preceded by a series of preliminary off-line experiments. In the developed technique, the components with different boiling points are fractionated and instantly analyzed by GC-MS. The obtained data sets illustrate dynamics of the distillation process. An important advantage of the distillation-GC-MS technique is that raw samples can directly be analyzed without removal of the non-volatile matrix residues that could contaminate the GC injection port and the column. Distilling the samples immediately before the injection to the GC column may reduce possible matrix effects—especially in the early phase of separation, when molecules with different volatilities co-migrate. It can also reduce losses of highly volatile components (during fraction collection and transfer). The two separation steps are partly orthogonal, what can slightly increase selectivity of the entire analysis. PMID:28337400

  5. Current status of the international DECOVALEX project: thermal-hydraulic-mechanical couplings

    Energy Technology Data Exchange (ETDEWEB)

    Kang, C. H.; Hwang, Y. S.; Kim, J

    1998-01-01

    THM coupling is an important issue to assess the safety of the HLW repositories. In this art report the current status of the international DECOVALEX project was reviewed to understand the most updated R and D direction on the groundwater flow assessment coupled with the decay heat and mechanical stress around a repository. Important progresses of DECOVALEX I, II, III and 2 were studied. Results show that even though there are good agreements on the predictions of stress and temperature, still the prediction of flow in discrete fracture network is incomplete. (author). 21 refs., 28 tabs., 33 figs

  6. Air-ground temperature coupling: analysis by means of Thermal Orbits

    Czech Academy of Sciences Publication Activity Database

    Čermák, Vladimír; Bodri, L.

    2016-01-01

    Roč. 6, č. 1 (2016), s. 112-122 ISSN 2160-0414 R&D Projects: GA ČR(CZ) GAP210/11/0183; GA MŠk(CZ) LG13040 Institutional support: RVO:67985530 Keywords : Thermal Orbits * temperature monitoring * air temperature vs ground temperature Subject RIV: DG - Athmosphere Sciences, Meteorology

  7. Modeling and experimental investigation of thermal-mechanical-electric coupling dynamics in a standing wave ultrasonic motor

    Science.gov (United States)

    Li, Xiang; Yao, Zhiyuan; He, Yigang; Dai, Shichao

    2017-09-01

    Ultrasonic motor operation relies on high-frequency vibration of a piezoelectric vibrator and interface friction between the stator and rotor/slider, which can cause temperature rise of the motor under continuous operation, and can affect motor parameters and performance in turn. In this paper, an integral model is developed to study the thermal-mechanical-electric coupling dynamics in a typical standing wave ultrasonic motor. Stick-slip motion at the contact interface and the temperature dependence of material parameters of the stator are taken into account in this model. The elastic, piezoelectric and dielectric material coefficients of the piezoelectric ceramic, as a function of temperature, are determined experimentally using a resonance method. The critical parameters in the model are identified via measured results. The resulting model can be used to evaluate the variation in output characteristics of the motor caused by the thermal-mechanical-electric coupling effects. Furthermore, the dynamic temperature rise of the motor can be accurately predicted under different input parameters using the developed model, which will contribute to improving the reliable life of a motor for long-term running.

  8. Coupling of electromagnetic and thermal codes. Induction heating; Couplage des codes electromagnetique et thermique. Le chauffage par induction

    Energy Technology Data Exchange (ETDEWEB)

    Colombani, M. [CEDRAT, (France)

    1997-12-31

    The development and adjustment of induction heating systems is quite delicate because two different subjects of physics are involved: magnetism (Foucault currents) and thermal engineering. Moreover, the magnetic and electrical properties depends on the temperature and the dissipated power depends on the magnetic and electrical properties and on the electrical excitation sources (geometry, intensity, frequency). The CEDRAT company has been involved since several years in the development of modeling softwares which allow to analyze these kind of problems. The most used is the FLUX2D software, developed by CEDRAT RECHERCHE in collaboration with the LEG (CNRS-INPG) and EdF, and which is used in several domains of applications (electric motors, actuators, high-voltage devices, magnetic recording, induction heating etc..). This software is based on a finite-element calculation method and, in the case of induction heating, it can perform different types of modeling: magnetic, thermal, temperature-dependant properties, weak and strong coupling, coupling with the electric circuit equations etc.. (J.S.)

  9. A Dual-Continuum Model for Brine Migration in Salt Associated with Heat-Generating Nuclear Waste: Fully Coupled Thermal-Hydro-Mechanical Analysis

    Science.gov (United States)

    Hu, M.; Rutqvist, J.

    2017-12-01

    The disposal of heat-generating nuclear waste in salt host rock establishes a thermal gradient around the waste package that may cause brine inclusions in the salt grains to migrate toward the waste package. In this study, a dual-continuum model is developed to analyze such a phenomenon. This model is based on the Finite Volume Method (FVM), and it is fully thermal-hydro-mechanical (THM) coupled. For fluid flow, the dual-continuum model considers flow in the interconnected pore space and also in the salt grains. The mass balance of salt and water in these two continua is separately established, and their coupling is represented by flux associated with brine migration. Together with energy balance, such a system produces a coupled TH model with strongly nonlinear features. For mechanical analysis, a new formulation is developed based on the Voronoi tessellated mesh. By relating each cell to several connected triangles, first-order approximation is constructed. The coupling between thermal and mechanical fields is only considered in terms of thermal expansion. And the coupling between the hydraulic and mechanical fields in terms of pore-volume effects is consistent with Biot's theory. Therefore, a fully coupled THM model is developed. Several demonstration examples are provided to verify the model. Last the new model is applied to analyze coupled THM behavior and the results are compared with experimental data.

  10. 27 CFR 27.40 - Distilled spirits.

    Science.gov (United States)

    2010-04-01

    ... 26 U.S.C. 5001 on each proof gallon and a proportionate tax at a like rate on all fractional parts of each proof gallon. All products of distillation, by whatever name known, which contain distilled...

  11. Thermal hydraulic studies of spallation target for one-way coupled ...

    Indian Academy of Sciences (India)

    1Laser and Plasma Technology Division; 2Nuclear Physics Division, Bhabha Atomic. Research Centre ... Abstract. BARC has recently proposed a one-way coupled ADS reactor. This reactor requires typically ~1 GeV proton beam with 2 mA of current. Approximately 8 kW of .... The overall target module dimensions and flow ...

  12. Extension of BEPU methods to Sub-channel Thermal-Hydraulics and to Coupled Three-Dimensional Neutronics/Thermal-Hydraulics Codes

    International Nuclear Information System (INIS)

    Avramova, M.; Ivanov, K.; Arenas, C.

    2013-01-01

    The principles that support the risk-informed regulation are to be considered in an integrated decision-making process. Thus, any evaluation of licensing issues supported by a safety analysis would take into account both deterministic and probabilistic aspects of the problem. The deterministic aspects will be addressed using Best Estimate code calculations and considering the associated uncertainties i.e. Plus Uncertainty (BEPU) calculations. In recent years there has been an increasing demand from nuclear research, industry, safety and regulation for best estimate predictions to be provided with their confidence bounds. This applies also to the sub-channel thermal-hydraulic codes, which are used to evaluate local safety parameters. The paper discusses the extension of BEPU methods to the sub-channel thermal-hydraulic codes on the example of the Pennsylvania State University (PSU) version of COBRA-TF (CTF). The use of coupled codes supplemented with uncertainty analysis allows to avoid unnecessary penalties due to incoherent approximations in the traditional decoupled calculations, and to obtain more accurate evaluation of margins regarding licensing limit. This becomes important for licensing power upgrades, improved fuel assembly and control rod designs, higher burn-up and others issues related to operating LWRs as well as to the new Generation 3+ designs being licensed now (ESBWR, AP-1000, EPR-1600 and etc.). The paper presents the application of Generalized Perturbation Theory (GPT) to generate uncertainties associated with the few-group assembly homogenized neutron cross-section data used as input in coupled reactor core calculations. This is followed by a discussion of uncertainty propagation methodologies, being implemented by PSU in cooperation of Technical University of Catalonia (UPC) for reactor core calculations and for comprehensive multi-physics simulations. (authors)

  13. Demonstration of the Performance of an Air-Type Photovoltaic Thermal (PVT System Coupled with a Heat-Recovery Ventilator

    Directory of Open Access Journals (Sweden)

    Jin-Hee Kim

    2016-09-01

    Full Text Available A heat-recovery ventilator (HRV effectively conducts ventilation by recovering waste heat from indoors to outdoors during heating periods. However, dew condensation associated with the HRV system may arise due to the difference between the indoor temperature and the very low outdoor temperature in winter, and this can decrease the heat exchange efficiency. These problems can be solved by the pre-heating of the incoming air, but additional energy is required when pursuing such a strategy. On the other hand, an air-type photovoltaic thermal (PVT system produces electricity and thermal energy simultaneously using air as the heat transfer medium. Moreover, the heated air from the air-type PVT system can be connected to the HRV to pre-heat the supply air instead of taking in the cold outdoor air. Thus, the ventilation efficiency can be improved and the problems arising during the heating period can be resolved. Consequentially, the heating energy required in a building can be reduced, with additional electricity acquired as well. In this paper, the performance of an air-type PVT system coupled with an HRV is assessed. To do this, air-type PVT collectors operating at 1 kWp were installed in an experimental house and coupled to an HRV system. Thermal performance and heating energy required during the winter season were analyzed experimentally. Furthermore, the electrical performances of the air-type PVT system with and without ventilation at the back side of the PV during the summer season were analyzed.

  14. Coupled optical and thermal detailed simulations for the accurate evaluation and performance improvement of molten salts solar towers

    Science.gov (United States)

    García-Barberena, Javier; Mutuberria, Amaia; Palacin, Luis G.; Sanz, Javier L.; Pereira, Daniel; Bernardos, Ana; Sanchez, Marcelino; Rocha, Alberto R.

    2017-06-01

    The National Renewable Energy Centre of Spain, CENER, and the Technology & Innovation area of ACS Cobra, as a result of their long term expertise in the CSP field, have developed a high-quality and high level of detail optical and thermal simulation software for the accurate evaluation of Molten Salts Solar Towers. The main purpose of this software is to make a step forward in the state-of-the-art of the Solar Towers simulation programs. Generally, these programs deal with the most critical systems of such plants, i.e. the solar field and the receiver, on an independent basis. Therefore, these programs typically neglect relevant aspects in the operation of the plant as heliostat aiming strategies, solar flux shapes onto the receiver, material physical and operational limitations, transient processes as preheating and secure cloud passing operating modes, and more. The modelling approach implemented in the developed program consists on effectively coupling detailed optical simulations of the heliostat field with also detailed and full-transient thermal simulations of the molten salts tube-based external receiver. The optical model is based on an accurate Monte Carlo ray-tracing method which solves the complete solar field by simulating each of the heliostats at once according to their specific layout in the field. In the thermal side, the tube-based cylindrical external receiver of a Molten Salts Solar Tower is modelled assuming one representative tube per panel, and implementing the specific connection layout of the panels as well as the internal receiver pipes. Each tube is longitudinally discretized and the transient energy and mass balances in the temperature dependent molten salts and steel tube models are solved. For this, a one dimensional radial heat transfer model based is used. The thermal model is completed with a detailed control and operation strategy module, able to represent the appropriate operation of the plant. An integration framework has been

  15. Lattice Boltzmann simulation of phase separation under dynamic temperature and shear: Coupling effects of shear convection and thermal diffusion.

    Science.gov (United States)

    Heping, Wang; Xingguo, Geng; Xiaoguang, Li; Duyang, Zang

    2016-10-01

    This paper presents an exploration of the separation behavior and pattern formation in a shear binary fluid with dynamic temperature after slow cooling via coupled lattice Boltzmann method. The phase separation procedure can be divided into three different stages: spinodal decomposition, domain growth, and domain stretch. The effect of thermal diffusion was observed to be more significant than that of shear convection in the spinodal decomposition stage, while the opposite was observed in the domain growth stage. The slow cooling temperature field significantly prolonged the spinodal decomposition stage, and decreased the separated domain size in domain growth stage. The phase behavior and pattern formation from the disordered state into the coexistence state after slow cooling was investigated during the domain stretch stage. Two typical length scales were obtained according to the equilibrium of two phases, where the number of layers in the corresponding domains was controllable by adjusting the Prandtl number for systems of different scales. The manner in which various viscosities and thermal diffusivities influence the morphologies and kinetic characterizations of the materials was also demonstrated: numerical results indicated that decrease in viscosity can cause increase in the growth exponents of separation fronts and velocity of domain growth, as well as increase in thermal diffusion.

  16. Thermal Entanglement in XXZ Heisenberg Model for Coupled Spin-Half and Spin-One Triangular Cell

    Science.gov (United States)

    Najarbashi, Ghader; Balazadeh, Leila; Tavana, Ali

    2018-01-01

    In this paper, we investigate the thermal entanglement of two-spin subsystems in an ensemble of coupled spin-half and spin-one triangular cells, (1/2, 1/2, 1/2), (1/2, 1, 1/2), (1, 1/2, 1) and (1, 1, 1) with the XXZ anisotropic Heisenberg model subjected to an external homogeneous magnetic field. We adopt the generalized concurrence as the measure of entanglement which is a good indicator of the thermal entanglement and the critical points in the mixed higher dimensional spin systems. We observe that in the near vicinity of the absolute zero, the concurrence measure is symmetric with respect to zero magnetic field and changes abruptly from a non-null to null value for a critical magnetic field that can be signature of a quantum phase transition at finite temperature. The analysis of concurrence versus temperature shows that there exists a critical temperature, that depends on the type of the interaction, i.e. ferromagnetic or antiferromagnetic, the anisotropy parameter and the strength of the magnetic field. Results show that the pairwise thermal entanglement depends on the third spin which affects the maximum value of the concurrence at absolute zero and at quantum critical points.

  17. Lightning Strike Ablation Damage Influence Factors Analysis of Carbon Fiber/Epoxy Composite Based on Coupled Electrical-Thermal Simulation

    Science.gov (United States)

    Yin, J. J.; Chang, F.; Li, S. L.; Yao, X. L.; Sun, J. R.; Xiao, Y.

    2017-10-01

    According to the mathematical analysis model constructed on the basis of energy-balance relationship in lightning strike, and accompany with the simplified calculation strategy of composite resin pyrolysis degree dependent electrical conductivity, an effective three dimensional thermal-electrical coupling analysis finite element model of composite laminate suffered from lightning current was established based on ABAQUS, to elucidate the effects of lighting current waveform parameters and thermal/electrical properties of composite laminate on the extent of ablation damage. Simulated predictions agree well with the composite lightning strike directed effect experimental data, illustrating the potential accuracy of the constructed model. The analytical results revealed that extent of composite lightning strike ablation damage can be characterized by action integral validly, there exist remarkable power function relationships between action integral and visual damage area, projected damage area, maximum damage depth and damage volume of ablation damage, and enhancing the electrical conductivity and specific heat of composite, ablation damage will be descended obviously, power function relationships also exist between electrical conductivity, specific heat and ablation damage, however, the impact of thermal conductivity on the extent of ablation damage is not notable. The conclusions obtained provide some guidance for composite anti-lightning strike structure-function integration design.

  18. Cascade Distillation Subsystem Development: Progress Toward a Distillation Comparison Test

    Science.gov (United States)

    Callahan, M. R.; Lubman, A.; Pickering, Karen D.

    2009-01-01

    Recovery of potable water from wastewater is essential for the success of long-duration manned missions to the Moon and Mars. Honeywell International and a team from NASA Johnson Space Center (JSC) are developing a wastewater processing subsystem that is based on centrifugal vacuum distillation. The wastewater processor, referred to as the Cascade Distillation Subsystem (CDS), utilizes an innovative and efficient multistage thermodynamic process to produce purified water. The rotary centrifugal design of the system also provides gas/liquid phase separation and liquid transport under microgravity conditions. A five-stage subsystem unit has been designed, built, delivered and integrated into the NASA JSC Advanced Water Recovery Systems Development Facility for performance testing. A major test objective of the project is to demonstrate the advancement of the CDS technology from the breadboard level to a subsystem level unit. An initial round of CDS performance testing was completed in fiscal year (FY) 2008. Based on FY08 testing, the system is now in development to support an Exploration Life Support (ELS) Project distillation comparison test expected to begin in early 2009. As part of the project objectives planned for FY09, the system will be reconfigured to support the ELS comparison test. The CDS will then be challenged with a series of human-gene-rated waste streams representative of those anticipated for a lunar outpost. This paper provides a description of the CDS technology, a status of the current project activities, and data on the system s performance to date.

  19. DECOVALEX III PROJECT. Mathematical Models of Coupled Thermal-Hydro-Mechanical Processes for Nuclear Waste Repositories. Executive Summary

    International Nuclear Information System (INIS)

    Jing, L.; Stephansson, O.; Kautzky, F.

    2005-02-01

    DECOVALEX is an international consortium of governmental agencies associated with the disposal of high-level nuclear waste in a number of countries. The consortium's mission is the DEvelopment of COupled models and their VALidation against EXperiments. Hence the acronym/name DECOVALEX. Currently, agencies from Canada, Finland, France, Germany, Japan, Spain, Switzerland, Sweden, United Kingdom, and the United States are in DECOVALEX. Emplacement of nuclear waste in a repository in geologic media causes a number of physical processes to be intensified in the surrounding rock mass due to the decay heat from the waste. The four main processes of concern are thermal, hydrological, mechanical and chemical. Interactions or coupling between these heat-driven processes must be taken into account in modeling the performance of the repository for such modeling to be meaningful and reliable. DECOVALEX III is organized around four tasks. The FEBEX (Full-scale Engineered Barriers EXperiment) in situ experiment being conducted at the Grimsel site in Switzerland is to be simulated and analyzed in Task 1. Task 2, centered around the Drift Scale Test (DST) at Yucca Mountain in Nevada, USA, has several sub-tasks (Task 2A, Task 2B, Task 2C and Task 2D) to investigate a number of the coupled processes in the DST. Task 3 studies three benchmark problems: a) the effects of thermal-hydrologic-mechanical (THM) coupling on the performance of the near-field of a nuclear waste repository (BMT1); b) the effect of upscaling THM processes on the results of performance assessment (BMT2); and c) the effect of glaciation on rock mass behavior (BMT3). Task 4 is on the direct application of THM coupled process modeling in the performance assessment of nuclear waste repositories in geologic media. This executive summary presents the motivation, structure, objectives, approaches, and the highlights of the main achievements and outstanding issues of the tasks studied in the DECOVALEX III project. The

  20. Cyclic distillation technology - A mini-review

    NARCIS (Netherlands)

    Bîldea, Costin Sorin; Pătruţ, Cătălin; Jørgensen, Sten Bay; Abildskov, Jens; Kiss, Anton A.

    2016-01-01

    Process intensification in distillation systems has received much attention during past decades, with the aim of increasing both energy and separation efficiency. Various techniques, such as internal heat-integrated distillation, membrane distillation, rotating packed bed, dividing-wall columns and

  1. The failure models of Sn-based solder joints under coupling effects of electromigration and thermal cycling

    Science.gov (United States)

    Ma, Limin; Zuo, Yong; Liu, Sihan; Guo, Fu; Wang, Xitao

    2013-01-01

    Currently, the main concerns of Pb-free solder joints are focusing on electromigration (EM) and thermomechanical fatigue (TMF) problems. Many models have been established to understand the failure mechanisms of the joint under such single test conditions. Based on the fact that almost all microelectronic devices serve in combination conditions of fluctuated temperature and electric current stressing, the coupling effects of EM and TMF on evolution of microstructure and resistance of solder joint had been investigated. The failure models of binary SnBi alloy and ternary SnAgCu (SAC) solder under the coupling stressing were divided into four and three different stages, respectively. The failure mechanisms were dominant by the relationship of phase segregation, polarity effect, phase coarsening, and the coefficient of thermal expansion mismatch. Cracks tend to form and propagate along the interface between intermetallic compound layers and solder matrix in SAC solder. However, grain boundary was considered as the nucleation sites for microcracks in SnBi solder. High current density alleviates the deterioration of solder at the beginning stage of coupling stressing through Joule heating effect. An abrupt jump of resistance could be observed before the failure of the joint. The failure molds were determined by interactions of EM behaviors and TMF damages.

  2. Neutronic and thermal-hydraulic coupling using Milonga and OpenFOAM codes: an approach using free software

    International Nuclear Information System (INIS)

    Silva, Vitor Vasconcelos Araújo

    2016-01-01

    The development of a fine mesh coupled neutronics/thermal-hydraulics framework mainly using open source software is presented. The contributions proposed go in two different directions: one, is the focus on the open software development, a concept widely spread in many fields of knowledge but rarely explored in the nuclear engineering field; the second, is the use of operating system shared memory as a fast and reliable storage area to couple the computational fluid dynamics (CFD) software OpenFOAM to the free and flexible reactor core analysis code Milonga. This concept was applied to simulate the behavior of the TRIGA Mark 1 IPR-R1 reactor fuel pin in steady-state mode. The macroscopic cross-sections for the model, a set of two-group cross-sections data, were generated using WIMSD-5B code. The results show that this innovative coupled system gives consistent results, encouraging system further development and its use for complex nuclear systems. (author)

  3. GCFR Coupled Neutronic and Thermal-Fluid-Dynamics Analyses for a Core Containing Minor Actinides

    Directory of Open Access Journals (Sweden)

    Diego Castelliti

    2009-01-01

    Full Text Available Problems about future energy availability, climate changes, and air quality seem to play an important role in energy production. While current reactor generations provide a guaranteed and economical energy production, new nuclear power plant generation would increase the ways and purposes in which nuclear energy can be used. To explore these new technological applications, several governments, industries, and research communities decided to contribute to the next reactor generation, called “Generation IV.” Among the six Gen-IV reactor designs, the Gas Cooled Fast Reactor (GCFR uses a direct-cycle helium turbine for electricity generation and for a CO2-free thermochemical production of hydrogen. Additionally, the use of a fast spectrum allows actinides transmutation, minimizing the production of long-lived radioactive waste in an integrated fuel cycle. This paper presents an analysis of GCFR fuel cycle optimization and of a thermal-hydraulic of a GCFR-prototype under steady-state and transient conditions. The fuel cycle optimization was performed to assess the capability of the GCFR to transmute MAs, while the thermal-hydraulic analysis was performed to investigate the reactor and the safety systems behavior during a LOFA. Preliminary results show that limited quantities of MA are not affecting significantly the thermal-fluid-dynamics behavior of a GCFR core.

  4. Global Effects of SuperParameterization on Hydro-Thermal Land-Atmosphere Coupling on Multiple Timescales and an Amplification of the Bowen Ratio

    Science.gov (United States)

    Qin, H.; Pritchard, M. S.; Kooperman, G. J.; Parishani, H.

    2017-12-01

    Conventional General Circulation Models (GCMs) in the Global Land-Atmosphere Coupling Experiment (GLACE) tend to produce overly strong Land-Atmosphere coupling (L-A coupling) strength. We investigate the effects of cloud SuperParameterization (SP) on L-A coupling on timescales longer than the diurnal where it has been previously shown to have a strong effect. Using the Community Atmosphere Model v3.5 (CAM3.5) and its SuperParameterized counterpart SPCAM3.5, we conducted experiments following the GLACE and Atmospheric Model Intercomparison Project (AMIP) protocols. On synoptic-to-subseasonal timescales, SP significantly mutes hydrologic L-A coupling on a global scale, through the atmospheric segment. But on longer seasonal timescales, SP does not exhibit detectable effects on hydrologic L-A coupling. Two regional effects of SP on thermal L-A coupling are also discovered and explored. Over the Arabian Peninsula, SP strikingly reduces thermal L-A coupling due to a control by mean regional rainfall reduction. Over the Southwestern US and Northern Mexico, however, SP remarkably enhances the thermal L-A coupling independent of rainfall or soil moisture. We argue that the cause may be a previously unrecognized effect of SP to amplify the simulated Bowen ratio. Not only does this help reconcile a puzzling local enhancement of thermal L-A coupling over the Southwestern US, but it is also demonstrated to be a robust, global effect of SP over land that is independent of model version and experiment design, and that has important consequences for climate change prediction.

  5. FRAPTRAN Fuel Rod Code and its Coupled Transient Analysis with the GENFLO Thermal-Hydraulic Code

    International Nuclear Information System (INIS)

    Valtonen, Keijo; Hamalainen, Anitta; Cunningham, Mitchel E.

    2002-01-01

    The FRAPTRAN computer code has been developed for the U.S. Nuclear Regulatory Commission (NRC) to calculate fuel behavior during power and/or cooling transients at burnup levels up to 65 MWd/kgM. FRAPTRAN has now been assessed and peer reviewed. STUK/VTT have coupled GENFLO to FRAPTRAN for calculations with improved coolant boundary conditions and prepared example calculations to show the effect of improving the coolant boundary conditions.

  6. FRAPTRAN Fuel Rod Code and its Coupled Transient Analysis with the GENFLO Thermal-Hydraulic Code

    Energy Technology Data Exchange (ETDEWEB)

    Valtonen, Keijo (Radiation and Nuclear Safety Authority, Finland); Hamalainen, Anitta (VTT Energy, Finland); Cunningham, Mitchel E.(BATTELLE (PACIFIC NW LAB))

    2002-05-01

    The FRAPTRAN computer code has been developed for the U.S. Nuclear Regulatory Commission (NRC) to calculate fuel behavior during power and/or cooling transients at burnup levels up to 65 MWd/kgM. FRAPTRAN has now been assessed and peer reviewed. STUK/VTT have coupled GENFLO to FRAPTRAN for calculations with improved coolant boundary conditions and prepared example calculations to show the effect of improving the coolant boundary conditions.

  7. ZZ-PBMR-400, OECD/NEA PBMR Coupled Neutronics/Thermal Hydraulics Transient Benchmark - The PBMR-400 Core Design

    International Nuclear Information System (INIS)

    Reitsma, Frederik

    2007-01-01

    Description of benchmark: This international benchmark, concerns Pebble-Bed Modular Reactor (PBMR) coupled neutronics/thermal hydraulics transients based on the PBMR-400 MW design. The deterministic neutronics, thermal-hydraulics and transient analysis tools and methods available to design and analyse PBMRs lag, in many cases, behind the state of the art compared to other reactor technologies. This has motivated the testing of existing methods for HTGRs but also the development of more accurate and efficient tools to analyse the neutronics and thermal-hydraulic behaviour for the design and safety evaluations of the PBMR. In addition to the development of new methods, this includes defining appropriate benchmarks to verify and validate the new methods in computer codes. The scope of the benchmark is to establish well-defined problems, based on a common given set of cross sections, to compare methods and tools in core simulation and thermal hydraulics analysis with a specific focus on transient events through a set of multi-dimensional computational test problems. The benchmark exercise has the following objectives: - Establish a standard benchmark for coupled codes (neutronics/thermal-hydraulics) for PBMR design; - Code-to-code comparison using a common cross section library ; - Obtain a detailed understanding of the events and the processes; - Benefit from different approaches, understanding limitations and approximations. Major Design and Operating Characteristics of the PBMR (PBMR Characteristic and Value): Installed thermal capacity: 400 MW(t); Installed electric capacity: 165 MW(e); Load following capability: 100-40-100%; Availability: ≥ 95%; Core configuration: Vertical with fixed centre graphite reflector; Fuel: TRISO ceramic coated U-235 in graphite spheres; Primary coolant: Helium; Primary coolant pressure: 9 MPa; Moderator: Graphite; Core outlet temperature: 900 C.; Core inlet temperature: 500 C.; Cycle type: Direct; Number of circuits: 1; Cycle

  8. Thermal Phenomena in the Friction Process of the TG15 - Hard Anodic Coating Couple

    Directory of Open Access Journals (Sweden)

    Służałek G.

    2016-09-01

    Full Text Available The paper presents a one-dimensional model of heat conduction in a couple consisting of a cylinder made of a sliding plastic material, TG15, and a cuboid made of alloy AW 6061 coated with a hard anodic coating, where the couple is heated with the heat generated during friction. TG15 is a composite material based on polytetrafluoroethylene (PTFE with a 15% graphite filler, used for piston rings in oil-free air-compressors. Measurement of temperature in the friction zone is extremely important for the understanding and analysis of the phenomena occurring therein. It is practically impossible to introduce a temperature sensor in such a place. Therefore, the interaction taking place in such a couple was modelled using numerical methods. In order to simplify and accelerate the calculations, a one-dimensional model and constant thermophysical parameters of the materials participating in friction were adopted. To solve the proposed model, the finite difference method was used (FDM. The resultant system of equations was solved by means of an explicit scheme.

  9. Consistent temperature coupling with thermal fluctuations of smooth particle hydrodynamics and molecular dynamics.

    Directory of Open Access Journals (Sweden)

    Georg C Ganzenmüller

    Full Text Available We propose a thermodynamically consistent and energy-conserving temperature coupling scheme between the atomistic and the continuum domain. The coupling scheme links the two domains using the DPDE (Dissipative Particle Dynamics at constant Energy thermostat and is designed to handle strong temperature gradients across the atomistic/continuum domain interface. The fundamentally different definitions of temperature in the continuum and atomistic domain - internal energy and heat capacity versus particle velocity - are accounted for in a straightforward and conceptually intuitive way by the DPDE thermostat. We verify the here-proposed scheme using a fluid, which is simultaneously represented as a continuum using Smooth Particle Hydrodynamics, and as an atomistically resolved liquid using Molecular Dynamics. In the case of equilibrium contact between both domains, we show that the correct microscopic equilibrium properties of the atomistic fluid are obtained. As an example of a strong non-equilibrium situation, we consider the propagation of a steady shock-wave from the continuum domain into the atomistic domain, and show that the coupling scheme conserves both energy and shock-wave dynamics. To demonstrate the applicability of our scheme to real systems, we consider shock loading of a phospholipid bilayer immersed in water in a multi-scale simulation, an interesting topic of biological relevance.

  10. Consistent temperature coupling with thermal fluctuations of smooth particle hydrodynamics and molecular dynamics.

    Science.gov (United States)

    Ganzenmüller, Georg C; Hiermaier, Stefan; Steinhauser, Martin O

    2012-01-01

    We propose a thermodynamically consistent and energy-conserving temperature coupling scheme between the atomistic and the continuum domain. The coupling scheme links the two domains using the DPDE (Dissipative Particle Dynamics at constant Energy) thermostat and is designed to handle strong temperature gradients across the atomistic/continuum domain interface. The fundamentally different definitions of temperature in the continuum and atomistic domain - internal energy and heat capacity versus particle velocity - are accounted for in a straightforward and conceptually intuitive way by the DPDE thermostat. We verify the here-proposed scheme using a fluid, which is simultaneously represented as a continuum using Smooth Particle Hydrodynamics, and as an atomistically resolved liquid using Molecular Dynamics. In the case of equilibrium contact between both domains, we show that the correct microscopic equilibrium properties of the atomistic fluid are obtained. As an example of a strong non-equilibrium situation, we consider the propagation of a steady shock-wave from the continuum domain into the atomistic domain, and show that the coupling scheme conserves both energy and shock-wave dynamics. To demonstrate the applicability of our scheme to real systems, we consider shock loading of a phospholipid bilayer immersed in water in a multi-scale simulation, an interesting topic of biological relevance.

  11. Key distillation in quantum cryptography

    Science.gov (United States)

    Slutsky, Boris Aron

    1998-11-01

    Quantum cryptography is a technique which permits two parties to communicate over an open channel and establish a shared sequence of bits known only to themselves. This task, provably impossible in classical cryptography, is accomplished by encoding the data on quantum particles and harnessing their unique properties. It is believed that no eavesdropping attack consistent with the laws of quantum theory can compromise the secret data unknowingly to the legitimate users of the channel. Any attempt by a hostile actor to monitor the data carrying particles while in transit reveals itself through transmission errors it must inevitably introduce. Unfortunately, in practice a communication is not free of errors even when no eavesdropping is present. Key distillation is a technique that permits the parties to overcome this difficulty and establish a secret key despite channel defects, under the assumption that every particle is handled independently from other particles by the enemy. In the present work, key distillation is described and its various aspects are studied. A relationship is derived between the average error rate resulting from an eavesdropping attack and the amount of information obtained by the attacker. Formal definition is developed of the security of the final key. The net throughput of secret bits in a quantum cryptosystem employing key distillation is assessed. An overview of quantum cryptographic protocols and related information theoretical results is also given.

  12. Driving Force Based Design of Cyclic Distillation

    DEFF Research Database (Denmark)

    Nielsen, Rasmus Fjordbak; Huusom, Jakob Kjøbsted; Abildskov, Jens

    2017-01-01

    Driving force based design is adopted from conventional continuous distillation to cyclic distillation. This leads to a definition of the operating line representation for the cyclic distillation process. A possible realization of the driving force design is presented, which implies operation...... with mixed phase feeds. A range of binary test cases, benzene toluene, methanol water, and ethanol water, are evaluated. The advantage of the design approach in cyclic distillation is shown to be analogous to the advantages obtained in conventional continuous distillation, including a minimal utility...

  13. 3D thermal modeling of TRISO fuel coupled with neutronic simulation

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Jianwei [Los Alamos National Laboratory; Uddin, Rizwan [UNIV OF ILLINIOS

    2010-01-01

    The Very High Temperature Gas Reactor (VHTR) is widely considered as one of the top candidates identified in the Next Generation Nuclear Power-plant (NGNP) Technology Roadmap under the U.S . Depanment of Energy's Generation IV program. TRlSO particle is a common element among different VHTR designs and its performance is critical to the safety and reliability of the whole reactor. A TRISO particle experiences complex thermo-mechanical changes during reactor operation in high temperature and high burnup conditions. TRISO fuel performance analysis requires evaluation of these changes on micro scale. Since most of these changes are temperature dependent, 3D thermal modeling of TRISO fuel is a crucial step of the whole analysis package. In this paper, a 3D numerical thermal model was developed to calculate temperature distribution inside TRISO and pebble under different scenarios. 3D simulation is required because pebbles or TRISOs are always subjected to asymmetric thermal conditions since they are randomly packed together. The numerical model was developed using finite difference method and it was benchmarked against ID analytical results and also results reported from literature. Monte-Carlo models were set up to calculate radial power density profile. Complex convective boundary condition was applied on the pebble outer surface. Three reactors were simulated using this model to calculate temperature distribution under different power levels. Two asymmetric boundary conditions were applied to the pebble to test the 3D capabilities. A gas bubble was hypothesized inside the TRISO kernel and 3D simulation was also carried out under this scenario. Intuition-coherent results were obtained and reported in this paper.

  14. New aspects of electronic excitations at the bismuth surface: Topology, thermalization and coupling to coherent phonons

    Energy Technology Data Exchange (ETDEWEB)

    Perfetti, L., E-mail: luca.perfetti@polytechnique.edu [Laboratoire des Solides Irradiés, Ecole Polytechnique – CEA/DSM – CNRS UMR 7642, 91128 Palaiseau (France); Faure, J. [Laboratoire d’Optique Appliquée, Ecole Polytechnique – ENSTA – CNRS UMR 7639, 91761 Palaiseau (France); Papalazarou, E.; Mauchain, J.; Marsi, M.; Goerbig, M.O. [Laboratoire de Physique des Solides, CNRS UMR 8502, Université Paris-Sud, F-91405 Orsay (France); Taleb-Ibrahimi, A.; Ohtsubo, Y. [Synchrotron SOLEIL, Saint-Aubin-BP 48, F-91192 Gif sur Yvette (France)

    2015-05-15

    We review measurements of angle and time resolved photoelectron spectroscopy on the surface states of the Bi(1 1 1) surface. The work covers several aspects of these surface states, discussing the topological properties, the strong anisotropy of the spin–orbit splitting and the dynamical relaxation of photoexcited electrons. Since time resolved experiments disentagle interaction processes in real time, the reported data offer a novel perspective on the motion of charge carriers in surface states and will serve as an unuseful reference for other systems with strong spin–orbit coupling.

  15. Neutronic/Thermal-hydraulic Coupling Technigues for Sodium Cooled Fast Reactor Simulations

    International Nuclear Information System (INIS)

    Ragusa, Jean; Siegel, Andrew; Ruggieri, Jean-Michel

    2010-01-01

    The objective of this project was to test new coupling algorithms and enable efficient and scalable multi-physics simulations of advanced nuclear reactors, with considerations regarding the implementation of such algorithms in massively parallel environments. Numerical tests were carried out to verify the proposed approach and the examples included some reactor transients. The project was directly related to the Sodium Fast Reactor program element of the Generation IV Nuclear Energy Systems Initiative and the Advanced Fuel cycle Initiative, and, supported the requirement of high-fidelity simulation as a mean of achieving the goals of the presidential Global Nuclear Energy Partnership (GNEP) vision.

  16. Cyclic distillation technology - A mini-review

    DEFF Research Database (Denmark)

    Bîldea, Costin Sorin; Pătruţ, Cătălin; Jørgensen, Sten Bay

    2016-01-01

    Process intensification in distillation systems has received much attention during the pastdecades, with the aim of increasing both energy and separation efficiency. Varioustechniques, such as internal heat-integrated distillation, membrane distillation, rotating packedbed, dividing-wall columns...... and reactive distillation were studied and reported in literature. All these techniques employ the conventional continuous counter-current contact of vapor andliquid phases. Cyclic distillation technology is based on an alternative operating mode usingseparate phase movement which leads to key practical...... advantages in both chemical andbiochemical processes. This article provides a mini-review of cyclic distillation technology.The topics covered include the working principle, design and control methods, main benefitsand limitations as well as current industrial applications. Cyclic distillation can...

  17. Numerical Methods for an Analysis of Hydrogen Behaviors Coupled with Thermal Hydraulics in a NPP Containment

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jongtae; Park, Rae-Joon; Hong, Seong-Wan; Kim, Gun-Hong [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2016-10-15

    In a containment safety analysis, multi-dimensional characteristics in thermal hydraulics are very important because the flow paths are not confined in a large free volume of the containment. The analysis is difficult because of a difference in length scales between a characteristic length of the flow and representative length of the containment. In order to simulate hydrogen and steam behaviors in a containment during postulated severe accidents, the GASFLOW code as a multi-dimensional analysis tool for NPP containment has been used for years because of its computational efficiency. Though GASFLOW is well developed for a real NPP containment analysis, there exist shortcomings in nodalization, two-phase and turbulence models. It is based on a Cartesian or cylindrical coordinate mesh, so it is impractical to refine a mesh locally in a region with a physical or geometrical complication. In this paper, the importance of the hydrogen safety in an NPP containment and requirements of the analysis tool was described. And physical models necessary for the hydrogen safety analysis code were listed. As a member of international collaborative project HYMERES for containment thermal hydraulics, KAERI is actively participating in an analytic working group. As an analysis tool for blind benchmarkes, the analysis code described in this paper was used. From the blind benchmark analyses, it was found that the code is very promising for hydrogen safety analysis. Currently, it is proposed to develop the code collaboratively in a hydrogen safety community based on an open-source strategy.

  18. Thermal Coupling Between the Ocean and Mantle of Europa: Implications for Ocean Convection

    Science.gov (United States)

    Soderlund, Krista M.; Schmidt, Britney E.; Wicht, Johannes; Blankenship, Donald D.

    2015-11-01

    Magnetic induction signatures at Europa indicate the presence of a subsurface ocean beneath the cold icy crust. The underlying mantle is heated by radioactive decay and tidal dissipation, leading to a thermal contrast sufficient to drive convection and active dynamics within the ocean. Radiogenic heat sources may be distributed uniformly in the interior, while tidal heating varies spatially with a pattern that depends on whether eccentricity or obliquity tides are dominant. The distribution of mantle heat flow along the seafloor may therefore be heterogeneous and impact the regional vigor of ocean convection. Here, we use numerical simulations of thermal convection in a global, Europa-like ocean to test the sensitivity of ocean dynamics to variations in mantle heat flow patterns. Towards this end, three end-member cases are considered: an isothermal seafloor associated with dominant radiogenic heating, enhanced seafloor temperatures at high latitudes associated with eccentricity tides, and enhanced equatorial seafloor temperatures associated with obliquity tides. Our analyses will focus on convective heat transfer since the heat flux pattern along the ice-ocean interface can directly impact the ice shell and the potential for geologic activity within it.

  19. Flexible parallel implicit modelling of coupled thermal-hydraulic-mechanical processes in fractured rocks

    Science.gov (United States)

    Cacace, Mauro; Jacquey, Antoine B.

    2017-09-01

    Theory and numerical implementation describing groundwater flow and the transport of heat and solute mass in fully saturated fractured rocks with elasto-plastic mechanical feedbacks are developed. In our formulation, fractures are considered as being of lower dimension than the hosting deformable porous rock and we consider their hydraulic and mechanical apertures as scaling parameters to ensure continuous exchange of fluid mass and energy within the fracture-solid matrix system. The coupled system of equations is implemented in a new simulator code that makes use of a Galerkin finite-element technique. The code builds on a flexible, object-oriented numerical framework (MOOSE, Multiphysics Object Oriented Simulation Environment) which provides an extensive scalable parallel and implicit coupling to solve for the multiphysics problem. The governing equations of groundwater flow, heat and mass transport, and rock deformation are solved in a weak sense (either by classical Newton-Raphson or by free Jacobian inexact Newton-Krylow schemes) on an underlying unstructured mesh. Nonlinear feedbacks among the active processes are enforced by considering evolving fluid and rock properties depending on the thermo-hydro-mechanical state of the system and the local structure, i.e. degree of connectivity, of the fracture system. A suite of applications is presented to illustrate the flexibility and capability of the new simulator to address problems of increasing complexity and occurring at different spatial (from centimetres to tens of kilometres) and temporal scales (from minutes to hundreds of years).

  20. Thermal coupling in low fields between the nuclear and electronic spins in Tm2+ doped CaF2

    International Nuclear Information System (INIS)

    Urbina, Cristian.

    1977-01-01

    It is shown that in a CaF 2 crystal doped with divalent thulium ions there is in low fields, a thermal coupling between the electron magnetic moments of Tm 2+ and the nuclear moments of 19 F. When these ones have been lowered down to temperature through dynamical high-field polarization and adiabatic demagnetization in succession the resulting polarisation of the formed ones can overstep their original polarization in high field. A trial is given to explain this Zeeman electronic energy cooling through nuclear Zeeman energy with invoking a thermal coupling between both systems through the spin-spin electronic interaction but no theoretical model is developed in view of a quantitative explanation of the dynamics of such a process. The magnetic resonance spectrum of Tm 2 + in low field is also investigated: an important shift and narrowing of the electron resonance line in low field are obtained when 19 F nuclei are very cold. This special spectral characters are explained as due to magnetic interactions between electronic impurities and the neighbouring 19 F nuclei and a theoretical model is developed (based on the local Weiss field approximation) which explains rather well the changes in the spectral shift as a function of the 19 F nucleus temperature. A second theoretical model has also been developed in view of a quantitative explanation of both the narrowing and shift of the spectrum, but its prediction disagree with the experimental results. It is shown that in low fieldsx it is possible to get rid of paramagnetic impurities after they have been reused as reducing agents for 19 F nucleus entropy populating at about 80%, a non magnetic metastable state with these impurities [fr

  1. Monitoring Soil Hydraulic and Thermal Properties using Coupled Inversion of Time-lapse Temperature and Electrical Resistance Data

    Science.gov (United States)

    Tran, A. P.; Dafflon, B.; Hubbard, S. S.; Kowalsky, M. B.; Tokunaga, T. K.; Faybishenko, B.; Long, P.

    2014-12-01

    Evaluation of spatiotemporal dynamics of heat transport and water flow in terrestrial environments is essential for understanding hydrological and biogeochemical processes. Electrical resistance tomography has been increasingly well used for monitoring subsurface hydrological processes and estimating soil hydraulic properties through coupled hydrogeophysical inversion. However, electrical resistivity depends on a variety of factors such as temperature, which may limit the accuracy of hydrogeophysical inversion. The main objective of this study is to develop a hydrogeophysical inversion framework to enable the incorporation of nonisothermal processes into the hydrogeophysical inversion procedure, and use of this procedure to investigate the effect of hydrological controls on biogeochemical cycles in terrestrial environments. We developed the coupled hydro-thermal-geophysical inversion approach, using the iTOUGH2 framework. In this framework, the heat transport and water flow are simultaneously modeled with TOUGH2 code, which effectively accounts for the multiphase, multi-component and nonisothermal flow in porous media. A flexible approach is used to incorporate petrophysical relationships and uncertainty to link soil moisture and temperature with the electrical resistivity. The developed approach was applied to both synthetic and field case studies. At the DOE subsurface biogeochemistry field site located near Rifle CO, seasonal snowmelt delivers a hydrological pulse to the system, which in turn influences the cycles of nitrogen, carbon and other critical elements. Using the new approach, we carried out numerical inversion of electrical resistance data collected along a 100 m transect at the Rifle site, and compared the results with field investigations of the soil, vadose zone, including the capillary fringe, and groundwater, as well as temperature and tensiometer measurements. Preliminary results show the importance of accounting for nonisothermal conditions to

  2. A hybrid multi-effect distillation and adsorption cycle

    KAUST Repository

    Thu, Kyaw

    2013-04-01

    This paper describes the development of a simple hybrid desalination system of a Multi-Effect Distillation (MED) and an adsorption (AD) cycle operating at sub-atmospheric pressures and temperatures. By hybridizing the conventional MED with an AD cycle, there is a symbiotic enhancement of performances of both cycles. The performance enhancement is attributed to (i) the cascade of adsorbent\\'s regeneration temperature and this extended the usage of thermal energy emanating from the brine heater and (ii) the vapor extraction from the last MED stage by AD cycle which provides the effect of lowering saturation temperatures of all MED stages to the extent of 5°C, resulting in scavenging of heat leaks into the MED stages from the ambient. The combined effects of the hybrid cycles increase the water production capacity of the desalination plant by nearly twofolds.In this paper, we demonstrate a hybrid cycle by simulating an 8-stage MED cycle which is coupled to an adsorption cycle for direct vapor extraction from the last MED stage. The sorption properties of silica gel is utilized (acting as a mechanical vapor compressor) to reduce the saturation temperatures of MED stages. The modeling utilizes the adsorption isotherms and kinetics of the adsorbent. +. adsorbate (silica-gel. +. water) pair along with the governing equations of mass, energy and concentration. For a 8-stage MED and AD cycles operating at assorted temperatures of 65-90°C, the results show that the water production rate increases from 60% to twofolds when compared to the MED alone. The performance ratio (PR) and gain output ratio (GOR) also improve significantly. © 2012 Elsevier Ltd.

  3. Fluid-Thermal-Structural Coupled Analysis of a Radial Inflow Micro Gas Turbine Using Computational Fluid Dynamics and Computational Solid Mechanics

    Directory of Open Access Journals (Sweden)

    Yonghui Xie

    2014-01-01

    Full Text Available A three-dimensional fluid-thermal-structural coupled analysis for a radial inflow micro gas turbine is conducted. First, a fluid-thermal coupled analysis of the flow and temperature fields of the nozzle passage and the blade passage is performed by using computational fluid dynamics (CFD. The flow and heat transfer characteristics of different sections are analyzed in detail. The thermal load and the aerodynamic load are then obtained from the temperature field and the pressure distribution. The stress distributions of the blade are finally studied by using computational solid mechanics (CSM considering three cases of loads: thermal load, aerodynamics load combined with centrifugal load, and all the three types of loads. The detailed parameters of the flow, temperature, and the stress are obtained and analyzed. The numerical results obtained provide a useful knowledge base for further exploration of radial gas turbine design.

  4. Coupling Chemical Kinetics and Flashes in Reactive, Thermal and Compositional Reservoir Simulation

    DEFF Research Database (Denmark)

    Kristensen, Morten Rode; Gerritsen, Margot G.; Thomsen, Per Grove

    2007-01-01

    of convergence and error test failures by more than 50% compared to direct integration without the new algorithm. To facilitate the algorithmic development we construct a virtual kinetic cell model. We use implicit one-step ESDIRK (Explicit Singly Diagonal Implicit Runge-Kutta) methods for integration...... of the kinetics. The kinetic cell model serves both as a tool for the development and testing of tailored solvers as well as a testbed for studying the interactions between chemical kinetics and phase behavior. A comparison between a Kvalue correlation based approach and a more rigorous equation of state based......Phase changes are known to cause convergence problems for integration of stiff kinetics in thermal and compositional reservoir simulations. We propose an algorithm for detection and location of phase changes based on discrete event system theory. The algorithm provides a robust way for handling...

  5. Passive thermal regulation of flat PV modules by coupling the mechanisms of evaporative and fin cooling

    Science.gov (United States)

    Chandrasekar, M.; Senthilkumar, T.

    2016-07-01

    A passive thermal regulation technique with fins in conjunction with cotton wicks is developed in the present work for controlling the temperature of PV module during its operation. Experiments were conducted with the developed technique in the location of Tiruchirappalli (78.6°E and 10.8°N), Tamil Nadu, India with flat 25 Wp PV module and its viability was confirmed. The PV module temperature got reduced by 12 % while the electrical yield is increased by 14 % with the help of the developed cooling system. Basic energy balance equation applicable for PV module was used to evaluate the module temperatures and a fair agreement was obtained between the theoretical and experimental values for the cases of with cooling and without cooling.

  6. Modeling of Steam Distillation Mechanism during Steam Injection Process Using Artificial Intelligence

    OpenAIRE

    Daryasafar, Amin; Ahadi, Arash; Kharrat, Riyaz

    2014-01-01

    Steam distillation as one of the important mechanisms has a great role in oil recovery in thermal methods and so it is important to simulate this process experimentally and theoretically. In this work, the simulation of steam distillation is performed on sixteen sets of crude oil data found in the literature. Artificial intelligence (AI) tools such as artificial neural network (ANN) and also adaptive neurofuzzy interference system (ANFIS) are used in this study as effective methods to simulat...

  7. Studies on optimal design and operation of integrated distillation arrangements

    Energy Technology Data Exchange (ETDEWEB)

    Christiansen, Atle Christer

    1997-12-31

    During the last decades, there has been growing concern in the chemical engineering environment over the task of developing more cost- and energy efficient process equipment. This thesis discusses measures for improving the end-use energy efficiency of separation systems. It emphasises a certain class of integrated distillation arrangements, in particular it considers means for direct coupling of distillation columns so as to use the underlying physics to facilitate more energy efficient separations. The numerical methods discussed are well suited to solve models of distillation columns. A tear and grid method is proposed that to some extent exploits the sparsity, since the number of tear variables required for solving a distillation model usually is rather small. The parameter continuation method described is well suited for ill-conditioned problems. The analysis of integrated columns is extended beyond the scope of numerical simulations by means of analytical results that applies in certain limiting cases. The consept of preferred separation, which is important for prefractionator arrangements, is considered. From this analysis is derived information that is important for the practical operation of such columns. Finally, the proposed numerical methods are used to optimize Petlyuk arrangements for separating ternary and quaternary mixtures. 166 refs., 130 figs., 20 tabs.

  8. Relaxation of a coherent, magnetic s–p model system coupled to one and two thermal baths and a laser pulse

    Energy Technology Data Exchange (ETDEWEB)

    Lefkidis, G. [Department of Physics and Research Center OPTIMAS, University of Kaiserslautern, Box 3049, 67653 Kaiserslautern (Germany); School of Mechanics, Civil Engineering and Architecture, Northwestern Polytechnical University, Xi’an 710072 (China); Sold, S.; Hübner, W. [Department of Physics and Research Center OPTIMAS, University of Kaiserslautern, Box 3049, 67653 Kaiserslautern (Germany)

    2017-06-15

    We study an s–p model magnetic system with a triplet ground state coupled to two temperature baths. By varying the temperatures we both generate non-thermal electronic distributions and create additional coherences in the density matrix of the system. Thus the thermally-induced magnetic response goes beyond the simple picture of majority-minority population dynamics. Furthermore, we discuss the influence of temperature induced relaxation effects on the dynamics induced by an optical perturbation for this quantum system.

  9. A coupled thermal and electrochemical study of lithium-ion battery cooled by paraffin/porous-graphite-matrix composite

    Science.gov (United States)

    Greco, Angelo; Jiang, Xi

    2016-05-01

    Lithium-ion (Li-ion) battery cooling using a phase change material (PCM)/compressed expanded natural graphite (CENG) composite is investigated, for a cylindrical battery cell and for a battery module scale. An electrochemistry model (average model) is coupled to the thermal model, with the addition of a one-dimensional model for the solution and solid diffusion using the nodal network method. The analysis of the temperature distribution of the battery module scale has shown that a two-dimensional model is sufficient to describe the transient temperature rise. In consequence, a two-dimensional cell-centred finite volume code for unstructured meshes is developed with additions of the electrochemistry and phase change. This two-dimensional thermal model is used to investigate a new and usual battery module configurations cooled by PCM/CENG at different discharge rates. The comparison of both configurations with a constant source term and heat generation based on the electrochemistry model showed the superiority of the new design. In this study, comparisons between the predictions from different analytical and computational tools as well as open-source packages were carried out, and close agreements have been observed.

  10. Exchange bias coupling in NiO/Ni bilayer tubular nanostructures synthetized by electrodeposition and thermal oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Yu, T., E-mail: work_tian@scu.edu.cn [College of Physical Science and Technology, Sichuan University, Chengdu 610064 (China); Zhang, Z.W.; Xu, Y.H. [College of Physical Science and Technology, Sichuan University, Chengdu 610064 (China); Liu, Y. [Analytical & Testing Center, Sichuan University, Chengdu 610064 (China); Li, W.J. [Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing 100190 (China); Nie, Y.; Zhang, X. [College of Physical Science and Technology, Sichuan University, Chengdu 610064 (China); Xiang, G., E-mail: gxiang@scu.edu.cn [College of Physical Science and Technology, Sichuan University, Chengdu 610064 (China)

    2017-05-01

    In this paper, we reported the synthesis of NiO/Ni bilayer nanotubes by electrodeposition and thermal oxidation using anodic aluminum oxide templates. The morphology, structure, chemical composition and magnetic properties, especially magnetic exchange bias induced by subsequent magnetic field cooling, in this one-dimensional antiferromagnetic/ferromagnetic hybrid system were investigated. It was found that the effect of the annealing temperature, which mainly dominated the thickness of the NiO layer, and the annealing time, which mainly dominated the grain size of the NiO, on the exchange bias field showed competitive relationship. The optimized exchange bias field was achieved by the combination of the shorter annealing time and higher annealing temperature. - Highlights: • NiO-Ni bilayer tubular nanotubes were fabricated by electrodeposition and thermal oxidation. • The exchange bias effect in NiO-Ni nanotubes was induced by magnetic field cooling. • The competitive effect of annealing temperature and annealing time on the exchange bias coupling was analyzed.

  11. Technical basis and programmatic requirements for large block testing of coupled thermal-mechanical-hydrological-chemical processes

    International Nuclear Information System (INIS)

    Lin, Wunan.

    1993-09-01

    This document contains the technical basis and programmatic requirements for a scientific investigation plan that governs tests on a large block of tuff for understanding the coupled thermal- mechanical-hydrological-chemical processes. This study is part of the field testing described in Section 8.3.4.2.4.4.1 of the Site Characterization Plan (SCP) for the Yucca Mountain Project. The first, and most important objective is to understand the coupled TMHC processes in order to develop models that will predict the performance of a nuclear waste repository. The block and fracture properties (including hydrology and geochemistry) can be well characterized from at least five exposed surfaces, and the block can be dismantled for post-test examinations. The second objective is to provide preliminary data for development of models that will predict the quality and quantity of water in the near-field environment of a repository over the current 10,000 year regulatory period of radioactive decay. The third objective is to develop and evaluate the various measurement systems and techniques that will later be employed in the Engineered Barrier System Field Tests (EBSFT)

  12. Validation of the Jarzynski relation for a system with strong thermal coupling: an isothermal ideal gas model.

    Science.gov (United States)

    Baule, A; Evans, R M L; Olmsted, P D

    2006-12-01

    We revisit the paradigm of an ideal gas under isothermal conditions. A moving piston performs work on an ideal gas in a container that is strongly coupled to a heat reservoir. The thermal coupling is modeled by stochastic scattering at the boundaries. In contrast to recent studies of an adiabatic ideal gas with a piston [R.C. Lua and A.Y. Grosberg, J. Phys. Chem. B 109, 6805 (2005); I. Bena, Europhys. Lett. 71, 879 (2005)], the container and piston stay in contact with the heat bath during the work process. Under this condition the heat reservoir as well as the system depend on the work parameter lambda and microscopic reversibility is broken for a moving piston. Our model is thus not included in the class of systems for which the nonequilibrium work theorem has been derived rigorously either by Hamiltonian [C. Jarzynski, J. Stat. Mech. (2004) P09005] or stochastic methods [G.E. Crooks, J. Stat. Phys. 90, 1481 (1998)]. Nevertheless the validity of the nonequilibrium work theorem is confirmed both numerically for a wide range of parameter values and analytically in the limit of a very fast moving piston, i.e., in the far nonequilibrium regime.

  13. The Effects of Coupling Agents on the Mechanical and Thermal Properties of Eucalyptus Flour/HDPE Composite

    Directory of Open Access Journals (Sweden)

    Metanawin Siripan

    2015-01-01

    Full Text Available The aim of this research was to study the effects of the coupling agents, FusabondTM E-528 (polyethylene-grafted maleic anhydride; PE-g-MA, MA and Amino Silane (Si, on the thermal properties, and mechanical properties of Eucalyptus flour-HDPE composite. Variation of the Eucalyptus flour contents in the HDPE resulted in properties of the composite. With increasing in the contents of Eucalyptus flour in polymer matrix, the mechanical properties of the HDPE composite decreased in EU-MA series samples while they were gradually decreased in EU-Si series samples. SEM micrographs showed the fracture surface of the HDPE/Eucalyptus composite at different ratios of Eucalyptus flour. SEM micrograpgh exhibited the dispersion of EU flour in polymer matrix. The samples of both coupling agents showed an increase in interfacial adhesion, observed for the considerable decreased of gaps between the matrix and the dispersed phase. However, the EU-MA sample appeared to be more uniformly than the EU-Si sample.

  14. Techno-economic study of hydrogen production by high temperature electrolysis and coupling with different thermal energy sources

    International Nuclear Information System (INIS)

    Rivera-Tinoco, R.

    2009-03-01

    This work focuses on the techno-economic study of massive hydrogen production by the High Temperature Electrolysis (HTE) process and also deals with the possibility of producing the steam needed in the process by using different thermal energy sources. Among several sources, those retained in this study are the biomass and domestic waste incineration units, as well as two nuclear reactors (European Pressurised water Reactor - EPR and Sodium Fast Reactor - SFR). Firstly, the technical evaluation of the steam production by each of these sources was carried out. Then, the design and modelling of the equipments composing the process, specially the electrolysers (Solid Oxides Electrolysis Cells), are presented. Finally, the hydrogen production cost for each energy sources coupled with the HTE process is calculated. Moreover, several sensibility studies were performed in order to determine the process key parameter and to evaluate the influence of the unit size effect, the electric energy cost, maintenance, the cells current density, their investment cost and their lifespan on the hydrogen production cost. Our results show that the thermal energy cost is much more influent on the hydrogen production cost than the steam temperature at the outlet stream of the thermal source. It seems also that the key parameters for this process are the electric energy cost and the c ells lifespan. The first one contributes for more than 70% of the hydrogen production cost. From several cell lifespan values, it seems that a 3 year value, rather than 1 year, could lead to a hydrogen production cost reduced on 34%. However, longer lifespan values going from 5 to 10 years would only lead to a 8% reduction on the hydrogen production cost. (author)

  15. Development and application of the coupled thermal-hydraulics and neutron-kinetics code ATHLET/BIPR-VVER for safety analysis

    Energy Technology Data Exchange (ETDEWEB)

    Lizorkin, M.; Nikonov, S. [Kurchatov Institute for Atomic Energy, Moscow (Russian Federation); Langenbuch, S.; Velkov, K. [Gesellschaft fur Anlagen- und Reaktorsicherheit (GRS) mbH, Garching (Germany)

    2006-07-01

    The coupled thermal-hydraulics and neutron-kinetics code ATHLET/BIPR-VVER was developed within a co-operation between the RRC Kurchatov Institute (KI) and GRS. The modeling capability of this coupled code as well as the status of validation by benchmark activities and comparison with plant measurements are described. The paper is focused on the modeling of flow mixing in the reactor pressure vessel including its validation and the application for the safety justification of VVER plants. (authors)

  16. Comparative Study of Experimental and Theoretical Convective, Evaporative for Two Model Distiller

    OpenAIRE

    Khaoula Hidouri; Ali Benhmidene; Bechir Chouachi

    2017-01-01

    The purification of brackish seawater becomes a necessity and not a choice against demographic and industrial growth especially in third world countries. Two models can be used in this work: simple solar still and simple solar still coupled with a heat pump. In this research, the productivity of water by Simple Solar Distiller (SSD) and Simple Solar Distiller Hybrid Heat Pump (SSDHP) was determined by the orientation, the use of heat pump, the simple or double glass cover. The productivity ca...

  17. Numerical and experimental investigations of coupled electromagnetic and thermal fields in superconducting accelerator magnets

    International Nuclear Information System (INIS)

    Mierau, Anna

    2013-01-01

    The new international facility for antiproton and ion research FAIR will be built in Darmstadt (Germany). The existing accelerator facility of GSI Helmholtzzentrum for Heavy Ion Research will serve as a pre-accelerator for the new facility. FAIR will provide high-energy antiproton and ion beams with unprecedented intensity and quality for fundamental research of states of matter and the evolution of the universe. The central component of FAIR's accelerator and storage rings complex is a double-ring accelerator consisting of two heavy ion synchrotrons SIS100 and SIS300. The SIS100 is the primary accelerator of FAIR. The desired beam properties of SIS100 require a design of the machine much more challenging than the conventional design of existing proton and ion synchrotrons. The key technical components of each synchrotron are the special electromagnets, which allow guiding the charged particles on their orbits in the synchrotron during the acceleration processes. For a stable operation of the SIS100's the magnets have to produce extremely homogeneous magnetic fields. Furthermore, the SIS100 high-intensity ion beam modes, for example with U 28+ ions, require an ultra-high vacuum in the beam pipe of the synchrotron, which can be generated effectively only at low temperatures below 15 K. Due to the field quality requirements for the magnets, the properties of the dynamic vacuum in the beam pipe but also in order to minimise future operating costs, fast ramped superconducting magnets will be used to guide the beam in SIS100. These magnets have been developed at GSI within the framework of the FAIR project. Developing a balanced design of a superconducting accelerator magnet requires a sound understanding of the interaction between its thermal and electromagnetic fields. Of special importance in this case are the magnetic field properties such as the homogeneity of the static magnetic field in the aperture of the magnet, and the dynamic heat losses of the whole magnet

  18. 3D Coupled Thermal-Hydraulic Model of the Lower Yarmouk Gorge, Jordan Rift Valley

    Science.gov (United States)

    Walther, M.; Magri, F.; Inbar, N.; Möller, P.; Raggad, M.; Rödiger, T.; Rosenthal, E.; Shentsis, I.; Siebert, C.; Volpi, G.

    2017-12-01

    It is supposed that the Lower Yarmouk Gorge (LYG), in the Jordan Rift Valley acts as the mixing zone of two crossing flow pathways: N-S from the Hermon Mountains and from the Ajlun Dome, and E-W from Jebel al Arab Mountain in Syria (also known as Huran Plateau or Yarmouk drainage basin). As a result, several springs can be found within the gorge. These are characterized by widespread temperatures (20 - 60 °C) which indicate that, beside the complex regional flow, also ascending thermal waters control the hydrologic behavior of the LYG. Previous simulations based on a conceptual simplified 3D model (Magri et al., 2016) showed that crossing flow paths result from the coexistence of convection, that can develop for example along NE-SW oriented faults within the gorge or in permeable aquifers below Maastrichtian aquiclude, and additional flow fields that are induced by the N-S topographic gradients. Here we present the first 3D hydrogeological model of the entire LYG that includes structural features based on actual logs and interpreted seismic lines from both Israeli and Jordanian territories. The model distinguishes seven units from upper Eocene to the Lower Triassic, accounting for major aquifers, aquicludes and deep-cutting faults. Recharges are implemented based on the numerical representation developed by Shentsis (1990) that considers relationships between mean annual rain and topographic elevation. The model reveals that topography-driven N-S and E-W flows strongly control the location of discharge areas while the anomalous spring temperature is not necessarily linked to the presence of fault convection. Local permeability anisotropy due to aquifers folding or facies changes are features sufficient for the rising of hot fluids. Shentsis, I., 1990. Mathematical models for long-term prediction of mountainous river runoff: methods, information and results, Hydrological Sciences Journal, 35:5, 487-500 Magri, F., Möller, S., Inbar, N., Möller, P., Raggad, M., R

  19. Thermal entanglement in an orthogonal dimer-plaquette chain with alternating Ising–Heisenberg coupling

    International Nuclear Information System (INIS)

    Paulinelli, H G; De Souza, S M; Rojas, Onofre

    2013-01-01

    In this paper we explore the entanglement in an orthogonal dimer-plaquette Ising–Heisenberg chain, assembled between plaquette edges, also known as orthogonal dimer plaquettes. The quantum entanglement properties involving an infinite chain structure are quite important, not only because the mathematical calculation is cumbersome but also because real materials are well represented by infinite chains. Using the local gauge symmetry of this model, we are able to map onto a simple spin-1 like Ising and spin-1/2 Heisenberg dimer model with single effective ion anisotropy. Thereafter this model can be solved using the decoration transformation and transfer matrix approach. First, we discuss the phase diagram at zero temperature of this model, where we find five ground states, one ferromagnetic, one antiferromagnetic, one triplet–triplet disordered and one triplet–singlet disordered phase, beside a dimer ferromagnetic–antiferromagnetic phase. In addition, we discuss the thermodynamic properties such as entropy, where we display the residual entropy. Furthermore, using the nearest site correlation function it is possible also to analyze the pairwise thermal entanglement for both orthogonal dimers. Additionally, we discuss the threshold temperature of the entangled region as a function of Hamiltonian parameters. We find a quite interesting thin reentrance threshold temperature for one of the dimers, and we also discuss the differences and similarities for both dimers. (paper)

  20. Gaseous phase benzene decomposition by non-thermal plasma coupled with nano titania catalyst

    International Nuclear Information System (INIS)

    Zhu, T.; Li, J.; Jin, Y. Q.; Liang, Y. H.; Ma, G. D.

    2009-01-01

    Synergistic effect of atmospheric non-thermal plasma generated by dielectric barrier discharge and nano titania photo catalyst for benzene decomposition was tested. The paper indicated the effect of photo catalyst on removal efficiency of benzene, the compare of photo catalyst characteristic in different high temperatures by heat treatment, analysis of by-products. The results showed that the effect of degradation was visible by added photo catalyst in the plasma reactor. When concentration of benzene was 600 mg/m 3 and electric field strength was 10 kV/cm, the removal efficiency of benzene was increased up to 81 % without photo catalyst. At the same condition, the removal efficiency was increased to 15 % higher with photo catalyst. Nano titania crystal was anatase crystal in 450 d eg C heat treatment which is best for benzene removal. The plasma reactor packed with photo catalyst shows a better selectivity of carbon dioxide than that without photo catalyst. By-products are mostly carbon dioxide, water and a small quantity of carbon monoxide

  1. Temperature sensor based on ladder-level assisted thermal coupling and thermal-enhanced luminescence in NaYF4: Nd³⁺.

    Science.gov (United States)

    Tian, Xiuna; Wei, Xiantao; Chen, Yonghu; Duan, Changkui; Yin, Min

    2014-12-01

    NaYF4: Nd³⁺ microprisms were synthesized by a hydrothermal method. The bands of near-infrared (NIR) luminescence originating from the 4F3/2, 4F5/2 and 4F7/2 levels of Nd³⁺ ions in NaYF4: Nd³⁺ microcrystals were measured under 574.8 nm excitation at various temperatures from 323 to 673 K. The fluorescence intensity ratios (FIRs) between any two of the three bands change monotonically with temperature and agree with the prediction assuming thermal couplings. A large relative temperature sensitivity of 1.12% K⁻¹ at 500K is reached with the FIR of 4F7/2 to 4F3/2 levels. In addition, anti-Stokes fluorescence from 4F5/2 level (740 nm) and 4F5/2,7/2 levels (740 nm and 803 nm) of Nd³⁺ ions was studied meticulously under 793.8 nm and 864.2 nm excitations, respectively. The intensities were shown to be greatly enhanced as temperature increases, and the 740 nm band from 4F7/2 level at 458 K increases in intensity by 170 fold relative to that at 298 K under the 793.8 nm excitation.

  2. Coupling Metallic Nanostructures to Thermally Responsive Polymers Allows the Development of Intelligent Responsive Membranes

    Directory of Open Access Journals (Sweden)

    J. Rubén Morones-Ramírez

    2014-01-01

    Full Text Available Development of porous membranes capable of controlling flow or changing their permeability to specific chemical entities, in response to small changes in environmental stimuli, is an area of appealing research, since these membranes present a wide variety of applications. The synthesis of these membranes has been mainly approached through grafting of environmentally responsive polymers to the surface walls of polymeric porous membranes. This synergizes the chemical stability and mechanical strength of the polymer membrane with the fast response times of the bonded polymer chains. Therefore, different composite membranes capable of changing their effective pore size with environmental triggers have been developed. A recent interest has been the development of porous membranes responsive to light, since these can achieve rapid, remote, noninvasive, and localized flow control. This work describes the synthesis pathway to construct intelligent optothermally responsive membranes. The method followed involved the grafting of optothermally responsive polymer-metal nanoparticle nanocomposites to polycarbonate track-etched porous membranes (PCTEPMs. The nanoparticles coupled to the polymer grafts serve as the optothermal energy converters to achieve optical switching of the pores. The results of the paper show that grafting of the polymer and in situ synthesis of the metallic particles can be easily achieved. In addition, the composite membranes allow fast and reversible switching of the pores using both light and heat permitting control of fluid flow.

  3. Thermal Behaviors and Lubrication Properties in Rotary Blade Coupling of Sports Utility Vehicles

    Science.gov (United States)

    Huang, Kuohsiu David; Tzeng, Sheng-Chung; Ma, Wei-Ping; Wu, Tai-Sheng

    This study attempts to improve the local high temperature distributions in rotary-blade-coupling (RBC), which is the source of motive power for sport-utility-vehicles (SUV). The experiment takes RBC with forced convection and circumferential ribs for the research on heat transfer enhancement. During rotation, RBC produces centrifugal fluid flow, convection phenomenon and temperature distributions that differ with rotational speed. Simultaneously, rotation enhances the turbulence intensity of the flow field, promoting heat transfer and destabilizing Taylor vortices. This instability influences the local heat transfer distribution and damages the machine parts because of overheating. To analyze the actual convection of the rotary flow field, the experiment testing section is designed based on the actual size of the RBC. In the experiment, the RBC is cooled via forced exterior oil supply, and ring-shaped turbulence ribs of three aspect ratios (AR=5/3, 2.5, and 10/3) are added to augment the heat transfer area, for discussing the axial temperature distributions at the top and bottom of the RBC. The experiment adopts major physical parameters within 2.856 × 105 ≤Ta≤2.031 × 106 and 0.053 ≤Re ≤1.054 to discuss the heat transfer effect in the interior rotary flow distribution groove of RBC in the four-wheel-drive (4WD) vehicle. Finally, based on the relevant experimental results, an empirical correlation is established for the reference of 4WD vehicle designers.

  4. Flux Enhancement in Membrane Distillation Using Nanofiber Membranes

    Directory of Open Access Journals (Sweden)

    T. Jiříček

    2016-01-01

    Full Text Available Membrane distillation (MD is an emerging separation technology, whose largest application potential lies in the desalination of highly concentrated solutions, which are out of the scope of reverse osmosis. Despite many attractive features, this technology is still awaiting large industrial application. The main reason is the lack of commercially available membranes with fluxes comparable to reverse osmosis. MD is a thermal separation process driven by a partial vapour pressure difference. Flux, distillate purity, and thermal efficiency are always in conflict, all three being strictly connected with pore size, membrane hydrophobicity, and thickness. The world has not seen the ideal membrane yet, but nanofibers may offer a solution to these contradictory requirements. Membranes of electrospun PVDF were tested under various conditions on a direct contact (DCMD unit, in order to determine the optimum conditions for maximum flux. In addition, their performance was compared to commonly available PTFE, PE, and PES membranes. It was confirmed that thinner membranes have higher fluxes and a lower distillate purity and also higher energy losses via conduction across the membrane. As both mass and heat transfer are connected, it is best to develop new membranes with a target application in mind, for the specific membrane module and operational conditions.

  5. Coupled thermal-optic effects and electrical modulation mechanism of birefringence crystal with Gaussian laser incidence

    International Nuclear Information System (INIS)

    Zhou Ji; He Zhi-Hong; Ma Yu; Dong Shi-Kui

    2015-01-01

    We study the Gaussian laser transmission in lithium niobate crystal (LiNbO 3 ) by using the finite element method to solve the electromagnetic field’s frequency domain equation and energy equation. The heat generated is identified by calculating the transmission loss of the electromagnetic wave in the birefringence crystal, and the calculated value of the heat generated is substituted into the energy equation. The electromagnetic wave’s energy losses induced by its multiple refractions and reflections along with the resulting physical property changes of the lithium niobate crystal are considered. Influences of ambient temperature and heat transfer coefficient on refraction and walk-off angles of O-ray and E-ray in the cases of different incident powers and crystal thicknesses are analyzed. The E-ray electrical modulation instances, in which the polarized light waveform is adjusted to the rated condition via an applied electrical field in the cases of different ambient temperatures and heat transfer coefficients, are provided to conclude that there is a correlation between ambient temperature and applied electrical field intensity and a correlation between surface heat transfer coefficient and applied electrical field intensity. The applicable electrical modulation ranges without crystal breakdown are proposed. The study shows that the electrical field-adjustable heat transfer coefficient range becomes narrow as the incident power decreases and wide as the crystal thickness increases. In addition, it is pointed out that controlling the ambient temperature is easier than controlling the heat transfer coefficient. The results of the present study can be used as a quantitative theoretical basis for removing the adverse effects induced by thermal deposition due to linear laser absorption in the crystal, such as depolarization or wave front distortion, and indicate the feasibility of adjusting the refractive index in the window area by changing the heat transfer

  6. Interface requirements for coupling a containment code to a reactor system thermal hydraulic codes

    International Nuclear Information System (INIS)

    Baratta, A.J.

    1997-01-01

    To perform a complete analysis of a reactor transient, not only the primary system response but the containment response must also be accounted for. Such transients and accidents as a loss of coolant accident in both pressurized water and boiling water reactors and inadvertent operation of safety relief valves all challenge the containment and may influence flows because of containment feedback. More recently, the advanced reactor designs put forth by General Electric and Westinghouse in the US and by Framatome and Seimens in Europe rely on the containment to act as the ultimate heat sink. Techniques used by analysts and engineers to analyze the interaction of the containment and the primary system were usually iterative in nature. Codes such as RELAP or RETRAN were used to analyze the primary system response and CONTAIN or CONTEMPT the containment response. The analysis was performed by first running the system code and representing the containment as a fixed pressure boundary condition. The flows were usually from the primary system to the containment initially and generally under choked conditions. Once the mass flows and timing are determined from the system codes, these conditions were input into the containment code. The resulting pressures and temperatures were then calculated and the containment performance analyzed. The disadvantage of this approach becomes evident when one performs an analysis of a rapid depressurization or a long term accident sequence in which feedback from the containment can occur. For example, in a BWR main steam line break transient, the containment heats up and becomes a source of energy for the primary system. Recent advances in programming and computer technology are available to provide an alternative approach. The author and other researchers have developed linkage codes capable of transferring data between codes at each time step allowing discrete codes to be coupled together

  7. Interface requirements for coupling a containment code to a reactor system thermal hydraulic codes

    Energy Technology Data Exchange (ETDEWEB)

    Baratta, A.J.

    1997-07-01

    To perform a complete analysis of a reactor transient, not only the primary system response but the containment response must also be accounted for. Such transients and accidents as a loss of coolant accident in both pressurized water and boiling water reactors and inadvertent operation of safety relief valves all challenge the containment and may influence flows because of containment feedback. More recently, the advanced reactor designs put forth by General Electric and Westinghouse in the US and by Framatome and Seimens in Europe rely on the containment to act as the ultimate heat sink. Techniques used by analysts and engineers to analyze the interaction of the containment and the primary system were usually iterative in nature. Codes such as RELAP or RETRAN were used to analyze the primary system response and CONTAIN or CONTEMPT the containment response. The analysis was performed by first running the system code and representing the containment as a fixed pressure boundary condition. The flows were usually from the primary system to the containment initially and generally under choked conditions. Once the mass flows and timing are determined from the system codes, these conditions were input into the containment code. The resulting pressures and temperatures were then calculated and the containment performance analyzed. The disadvantage of this approach becomes evident when one performs an analysis of a rapid depressurization or a long term accident sequence in which feedback from the containment can occur. For example, in a BWR main steam line break transient, the containment heats up and becomes a source of energy for the primary system. Recent advances in programming and computer technology are available to provide an alternative approach. The author and other researchers have developed linkage codes capable of transferring data between codes at each time step allowing discrete codes to be coupled together.

  8. Hybrid wind-power-distillation plant

    Directory of Open Access Journals (Sweden)

    Ninić Neven

    2012-01-01

    Full Text Available This paper reports and elaborates on the idea of a solar distiller and an offshore wind power plant operating together. The subject under discussion is a single-stage solar distillation plant with vaporization, using adiabatic expansion in the gravitational field inside a wind power plant supporting column. This scheme divides investment costs for electric power and distillate production. In the region of the Adriatic Sea, all electric power produced could be “converted” to hydrogen using less than 10% of the distillate produced.

  9. Treatment of batik waste using distillation method

    Science.gov (United States)

    Riyanto, Sidiq, Nurma Yunita; Hidayah, Nailil

    2017-12-01

    In this study has been the treatment of batik waste using distillation method. This study aims to the treatment of batik waste using distillation method. Batik is a world heritage that has an impact on economic improvement and environmental damage. Batik waste is a hazardous and toxic waste material. Batik waste in this research has been taken from Batik Industry in Yogyakarta, Indonesia. Batik waste of 5 L is included in the distillation apparatus, then the distillation run for 4 hours. The distillation product of solids and liquids is collected and analyzed. The solid produced at the distillation boiler was analyzed by FTIR. The distillation liquid was analyzed ammonia and COD concentration using UV-Vis Spectrophotometer. The result of the analysis showed that based on FTIR spectra obtained by dye with high purity. The analysis results shown are of ammonia, COD and pH were 0.652 mg/L, 238.31 mg/L, and 7.306, respectively. The compounds produced by boiler are the azo dye based on the spectrum at wave numbers 1554.07 cm-1. The conclusion of this research is that the distillation method is very suitable for the treatment of the batik waste at small batik industry. Advantages of distillation techniques that can be obtained two products are water and dye that can be used in batik industry.

  10. Predictive uncertainty reduction in coupled neutron-kinetics/thermal hydraulics modeling of the BWR-TT2 benchmark

    Energy Technology Data Exchange (ETDEWEB)

    Badea, Aurelian F., E-mail: aurelian.badea@kit.edu [Karlsruhe Institute of Technology, Vincenz-Prießnitz-Str. 3, 76131 Karlsruhe (Germany); Cacuci, Dan G. [Center for Nuclear Science and Energy/Dept. of ME, University of South Carolina, 300 Main Street, Columbia, SC 29208 (United States)

    2017-03-15

    Highlights: • BWR Turbine Trip 2 (BWR-TT2) benchmark. • Substantial (up to 50%) reduction of uncertainties in the predicted transient power. • 6660 uncertain model parameters were calibrated. - Abstract: By applying a comprehensive predictive modeling methodology, this work demonstrates a substantial (up to 50%) reduction of uncertainties in the predicted total transient power in the BWR Turbine Trip 2 (BWR-TT2) benchmark while calibrating the numerical simulation of this benchmark, comprising 6090 macroscopic cross sections, and 570 thermal-hydraulics parameters involved in modeling the phase-slip correlation, transient outlet pressure, and total mass flow. The BWR-TT2 benchmark is based on an experiment that was carried out in 1977 in the NPP Peach Bottom 2, involving the closure of the turbine stop valve which caused a pressure wave that propagated with attenuation into the reactor core. The condensation of the steam in the reactor core caused by the pressure increase led to a positive reactivity insertion. The subsequent rise of power was limited by the feedback and the insertion of the control rods. The BWR-TT2 benchmark was modeled with the three-dimensional reactor physics code system DYN3D, by coupling neutron kinetics with two-phase thermal-hydraulics. All 6660 DYN3D model parameters were calibrated by applying a predictive modeling methodology that combines experimental and computational information to produce optimally predicted best-estimate results with reduced predicted uncertainties. Simultaneously, the predictive modeling methodology yields optimally predicted values for the BWR total transient power while reducing significantly the accompanying predicted standard deviations.

  11. Uncertainties in coupled thermal-hydrological processes associated with the drift scale test at Yucca Mountain, Nevada

    International Nuclear Information System (INIS)

    Mukhopadhyay, Sumitra; Tsang, Y.W.

    2002-01-01

    Understanding thermally driven coupled hydrological, mechanical, and chemical processes in unsaturated fractured tuff is essential for evaluating the performance of the potential radioactive waste repository at Yucca Mountain, Nevada. The Drift Scale Test (DST), intended for acquiring such an understanding of these processes, has generated a huge volume of temperature and moisture redistribution data. Sophisticated thermal hydrological (TH) conceptual models have yielded a good fit between simulation results and those measured data. However, some uncertainties in understanding the TH processes associated with the DST still exist. This paper evaluates these uncertainties and provides quantitative estimates of the range of these uncertainties. Of particular interest for the DST are the uncertainties resulting from the unmonitored loss of vapor through an open bulkhead of the test. There was concern that the outcome from the test might have been significantly altered by these losses. Using alternative conceptual models, we illustrate that predicted mean temperatures from the DST are within 1 degree C of the measured mean temperatures through the first two years of heating. The simulated spatial and temporal evolution of drying and condensation fronts is found to be qualitatively consistent with measured saturation data. Energy and mass balance computation shows that no more than 13 percent of the input energy is lost because of vapor leaving the test domain through the bulkhead. The change in average saturation in fractures is also relatively small. For a hypothetical situation in which no vapor is allowed to exit through the bulkhead, the simulated average fracture saturation is not qualitatively different enough to be discerned by measured moisture redistribution data. This leads us to conclude that the DST, despite the uncertainties associated with open field testing, has provided an excellent understanding of the TH processes

  12. The axial power distribution validation of the SCWR fuel assembly with coupled neutronics-thermal hydraulics method

    Energy Technology Data Exchange (ETDEWEB)

    Xi, Xi [CNNC Key Laboratory on Nuclear Reactor Thermal Hydraulics Technology, Nuclear Power Institute of China, Chengdu 610041 (China); Xiao, Zejun, E-mail: fabulous_2012@sina.com [CNNC Key Laboratory on Nuclear Reactor Thermal Hydraulics Technology, Nuclear Power Institute of China, Chengdu 610041 (China); Yan, Xiao; Li, Yongliang; Huang, Yanping [CNNC Key Laboratory on Nuclear Reactor Thermal Hydraulics Technology, Nuclear Power Institute of China, Chengdu 610041 (China)

    2013-05-15

    Highlights: ► CFX and MCNP codes are suitable to calculate the axial power profile of the FA. ► The partition method in the calculation will affect the final result. ► The density feedback has little effect on the axial power profile of CSR1000 FA. -- Abstract: SCWR (super critical water reactor) is one of the IV generation nuclear reactors in the world. In a typical SCWR the water enters the reactor from the cold leg with a temperature of 280 °C and then leaves the core with a temperature of 500 °C. Due to the sharp change in temperature, there is a huge density change of the water along the axial direction of the fuel assembly (FA), which will affect the moderating power of the water. So the axial power distribution of the SCWR FA could be different from the traditional PWR FA.In this paper, it is the first time that the thermal hydraulics code CFX and neutronics code MCNP are used to analyze the axial power distribution of the SCWR FA. First, the factors in the coupled method which could affect the result are analyzed such as the initialization value or the partition method especially in the MCNP code. Then the axial power distribution of the Europe HPLWR FA is obtained by the coupled method with the two codes and the result is compared with that obtained by Waata and Reiss. There is a good agreement among the three kinds of results. At last, this method is used to calculate the axial power distribution of the Chinese SCWR (CSR1000) FA. It is found the axial power profile of the CSR1000 FA is not so sensitive to the change of the moderator density.

  13. The path to clean energy: direct coupling of nuclear and renewable technologies for thermal and electrical applications

    Energy Technology Data Exchange (ETDEWEB)

    Bragg-Sitton, Shannon [Idaho National Lab. (INL), Idaho Falls, ID (United States). Nuclear Fuel Performance and Design; Boardman, Richard [Idaho National Lab. (INL), Idaho Falls, ID (United States). Advanced Process and Decision Systems; Ruth, Mark [National Renewable Energy Lab. (NREL), Golden, CO (United States). Strategic Energy Analysis Center

    2015-07-01

    The U.S. Department of Energy (DOE) recognizes the need to transform the energy infrastructure of the U.S. and elsewhere to systems that can significantly reduce environmental impacts in an efficient and economically viable manner while utilizing both clean energy generation sources and hydrocarbon resources. Thus, DOE is supporting research and development that could lead to more efficient utilization of clean nuclear and renewable energy generation sources. A concept being advanced by the DOE Offices of Nuclear Energy (NE) and Energy Efficiency and Renewable Energy (EERE) is tighter coupling of nuclear and renewable energy sources in a manner that better optimizes energy use for the combined electricity, industrial manufacturing, and the transportation sectors. This integration concept has been referred to as a “hybrid system” that is capable of providing energy (thermal or electrical) where it is needed, when it is needed. For the purposes of this work, the hybrid system would integrate two or more energy resources to generate two or more products, one of which must be an energy commodity, such as electricity or transportation fuel. This definition requires coupling of subsystems ‘‘behind’’ the electrical transmission bus, where energy flows are dynamically apportioned as necessary to meet demand and the system has a single connection to the grid that provides dispatchable electricity as required while capital intensive generation assets operate at full capacity. Development of integrated energy systems for an “energy park” must carefully consider the intended location and the associated regional resources, traditional industrial processes, energy delivery infrastructure, and markets to identify viable region-specific system configurations. This paper will provide an overview of the current status of regional hybrid energy system design, development and application of dynamic analysis tools to assess technical and economic performance, and

  14. 40 CFR 721.4500 - Isopropylamine distillation residues and ethylamine distillation residues.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Isopropylamine distillation residues and ethylamine distillation residues. 721.4500 Section 721.4500 Protection of Environment... residues and ethylamine distillation residues. (a) Chemical substances and significant new use subject to...

  15. Recycling of acetone by distillation

    International Nuclear Information System (INIS)

    Brennan, D.L.; Campbell, B.A.; Phelan, J.E.; Harper, M.

    1992-09-01

    The Resource Conservation Recovery Act (RCRA) identifies spent acetone solvent as a listed hazardous waste. At Fernald, acetone has been spent that has been contaminated with radionuclides and therefore is identified as a mixed hazardous waste. At the time of this publication there is no available approved method of recycling or disposal of radioactively contaminated spent acetone solvent. The Consent Decree with the Ohio EPA and the Consent Agreement with the United States EPA was agreed upon for the long-term compliant storage of hazardous waste materials. The purpose of this project was to demonstrate the feasibility for safely decontaminating spent acetone to background levels of radioactivity for reuse. It was postulated that through heat distillation, radionuclides could be isolated from the spent acetone

  16. Development of neutronic models for the thermal hydraulics coupling of the MSFR and the calculation of effective kinetic parameters

    International Nuclear Information System (INIS)

    Laureau, Axel

    2015-01-01

    In this PhD thesis, we describe the development of innovative neutronic models for their coupling with thermal hydraulics such that they combine precision and reasonable computational times. One of the main cases where this method is applied is the Molten Salt Fast Reactor (MSFR) whose combines a fast neutron spectrum with a thorium cycle. In this fourth generation reactor, the motion of the delayed neutron precursors and the associated phenomena have to be taken into account due to the liquid fuel circulation. The starting point for these developments was the preliminary design of this type of system where a dedicated multi-physical representation was needed to study the reactor performance in steady and transient conditions. As a first step, a stationary coupling was developed. A neutronic model based on a stochastic approach was associated to a CFD (Computational Fluid Dynamics) code to solve the Navier Stokes equations for turbulent flows and the transport of the delayed neutron precursors. The impact of this precursor motion is taken into account by reconstructing the prompt shower that they generate. This approach, called by shower, views the critical reactor as a prompt subcritical reactor that amplifies a source of delayed neutrons. A second step consisted in developing a neutronic model based on a time dependent version of the fission matrices (Transient Fission Matrix or TFM) so as to enable reactor transient studies. With the TFM model, an initial computation of the matrices with a stochastic code (MCNP, SERPENT) allows the characterization of the global spatial and time dependent neutronic response of the reactor with a precision close to that of a Monte Carlo calculation. The information thus obtained is then used to calculate transients, while retaining the advantage of reduced computational time. The TFM model, which can be used for various system concepts, also allows the evaluation of effective kinetic parameters such as the effective fraction of

  17. Exergy analysis of a MSF distillation plant

    International Nuclear Information System (INIS)

    Kahraman, Nafiz; Cengel, Yunus A.

    2005-01-01

    In this paper, a large MSF distillation plant in the gulf area is analyzed thermodynamically using actual plant operation data. Exergy flow rates are evaluated throughout the plant, and the exergy flow diagram is prepared. The rates of exergy destruction and their percentages are indicated on the diagram so that the locations of highest exergy destruction can easily be identified. The highest exergy destruction (77.7%) occurs within the MSF unit, as expected, and this can be reduced by increasing the number of flashing stages. The exergy destruction in the pumps and motors account for 5.3% of the total, and this also can be reduced by using high efficiency motors and pumps. The plant is determined to have a second law efficiency of just 4.2%, which is very low. This indicates that there are major opportunities in the plant to reduce exergy destruction and, thus, the amount of electric and thermal energy supplied, making the operation of the plant more cost effective

  18. Exergy analysis of a MSF distillation plant

    Energy Technology Data Exchange (ETDEWEB)

    Kahraman, Nafiz [Department of Mechanical Engineering, Erciyes University, Kayseri (Turkey)]. E-mail: nafiz@erciyes.edu.tr; Cengel, Yunus A. [Department of Mechanical Engineering/312, University of Nevada, Reno, NV 89557 (United States)

    2005-09-15

    In this paper, a large MSF distillation plant in the gulf area is analyzed thermodynamically using actual plant operation data. Exergy flow rates are evaluated throughout the plant, and the exergy flow diagram is prepared. The rates of exergy destruction and their percentages are indicated on the diagram so that the locations of highest exergy destruction can easily be identified. The highest exergy destruction (77.7%) occurs within the MSF unit, as expected, and this can be reduced by increasing the number of flashing stages. The exergy destruction in the pumps and motors account for 5.3% of the total, and this also can be reduced by using high efficiency motors and pumps. The plant is determined to have a second law efficiency of just 4.2%, which is very low. This indicates that there are major opportunities in the plant to reduce exergy destruction and, thus, the amount of electric and thermal energy supplied, making the operation of the plant more cost effective.

  19. Characterization of a 50kW Inductively Coupled Plasma Torch for Testing of Ablative Thermal Protection Materials

    Science.gov (United States)

    Greene, Benton R.; Clemens, Noel T.; Varghese, Philip L.; Bouslog, Stanley A.; Del Papa, Steven V.

    2017-01-01

    With the development of new manned spaceflight capabilities including NASA's Orion capsule and the Space-X Dragon capsule, there is a renewed importance of understanding the dynamics of ablative thermal protection systems. To this end, a new inductively coupled plasma torch facility is being developed at UT-Austin. The torch operates on argon and/or air at plasma powers up to 50 kW. In the present configuration the flow issues from a low-speed subsonic nozzle and the hot plume is characterized using slug calorimetry and emission spectroscopy. Preliminary measurements using emission spectroscopy have indicated that the torch is capable of producing an air plasma with a temperature between 6,000 K and 8,000 K depending on the power and flow settings and an argon plasma with a temperature of approximately 12,000 K. The operation envelope was measured, and heat flux measured for every point within the envelope using both a slug calorimeter and a Gardon gauge heat flux sensor. The torch was found to induce a stagnation point heat flux of between 90 and 225 W/sq cm.

  20. Analysis of Control Rod Drop Accidents for the Canadian SCWR Using Coupled 3-Dimensional Neutron Kinetics and Thermal Hydraulics

    Directory of Open Access Journals (Sweden)

    Frederic Salaun

    2018-01-01

    Full Text Available The Canadian Supercritical Water-cooled Reactor (SCWR, a GEN IV reactor design, is a hybrid design of the well-established CANDU™ and Boiling Water Reactor with water above its thermodynamic critical point. Given the batch fueled design, control rods are used to manage the reactivity throughout the fuel cycle. This paper examines the consequences of a control rod drop accident (CRDA for the Canadian SCWR. The asymmetry generated by the dropped rod requires an accurate 3-dimensional neutron kinetics calculation coupled to a detailed thermal-hydraulic model. Before simulating the CRDAs, the proper implementation of the 3D reactivity feedback was verified and various sensitivity studies were performed. This work demonstrates that the proposed safety systems for the SCWR core are capable of terminating the CRDA sequence prior to exceeding maximum sheath and centerline temperatures. In one instance involving a rod on the periphery of the core, the proposed trip setpoint (115% FP was not exceeded and a new steady state was reached. Therefore it is recommended that the design also include provisions for a high-log rate and/or local Neutron Overpower Protection (NOP trips, similar to existing CANDU designs such that reactor shutdown can be assured for such spatial anomalies.

  1. Coupled fluid-thermal analysis of low-pressure sublimation and condensation with application to freeze-drying

    Science.gov (United States)

    Ganguly, Arnab

    Freeze-drying is a low-pressure, low-temperature condensation pumping process widely used in the manufacture of bio-pharmaceuticals for removal of solvents by sublimation. The goal of the process is to provide a stable dosage form by removing the solvent in such a way that the sensitive molecular structure of the active substance is least disturbed. The vacuum environment presents unique challenges for understanding and controlling heat and mass transfer in the process. As a result, the design of equipment and associated processes has been largely empirical, slow and inefficient. A comprehensive simulation framework to predict both, process and equipment performance is critical to improve current practice. A part of the dissertation is aimed at performing coupled fluid-thermal analysis of low-pressure sublimation-condensation processes typical of freeze-drying technologies. Both, experimental and computational models are used to first understand the key heat transfer modes during the process. A modeling and computational framework, validated with experiments for analysis of sublimation, water-vapor flow and condensation in application to pharmaceutical freeze-drying is developed. Augmented with computational fluid dynamics modeling, the simulation framework presented here allows to predict for the first time, dynamic product/process conditions taking into consideration specifics of equipment design. Moreover, by applying the modeling framework to process design based on a design-space approach, it has demonstrated that there is a viable alternative to empiricism.

  2. The Verification of Coupled Neutronics Thermal-Hydraulics Code NODAL3 in the PWR Rod Ejection Benchmark

    Directory of Open Access Journals (Sweden)

    Surian Pinem

    2014-01-01

    Full Text Available A coupled neutronics thermal-hydraulics code NODAL3 has been developed based on the few-group neutron diffusion equation in 3-dimensional geometry for typical PWR static and transient analyses. The spatial variables are treated by using a polynomial nodal method while for the neutron dynamic solver the adiabatic and improved quasistatic methods are adopted. In this paper we report the benchmark calculation results of the code against the OECD/NEA CRP PWR rod ejection cases. The objective of this work is to determine the accuracy of NODAL3 code in analysing the reactivity initiated accident due to the control rod ejection. The NEACRP PWR rod ejection cases are chosen since many organizations participated in the NEA project using various methods as well as approximations, so that, in addition to the reference solutions, the calculation results of NODAL3 code can also be compared to other codes’ results. The transient parameters to be verified are time of power peak, power peak, final power, final average Doppler temperature, maximum fuel temperature, and final coolant temperature. The results of NODAL3 code agree well with the PHANTHER reference solutions in 1993 and 1997 (revised. Comparison with other validated codes, DYN3D/R and ANCK, shows also a satisfactory agreement.

  3. Methods and Models for the Coupled Neutronics and Thermal-Hydraulics Analysis of the CROCUS Reactor at EFPL

    Directory of Open Access Journals (Sweden)

    A. Rais

    2015-01-01

    Full Text Available In order to analyze the steady state and transient behavior of the CROCUS reactor, several methods and models need to be developed in the areas of reactor physics, thermal-hydraulics, and multiphysics coupling. The long-term objectives of this project are to work towards the development of a modern method for the safety analysis of research reactors and to update the Final Safety Analysis Report of the CROCUS reactor. A first part of the paper deals with generation of a core simulator nuclear data library for the CROCUS reactor using the Serpent 2 Monte Carlo code and also with reactor core modeling using the PARCS code. PARCS eigenvalue, radial power distribution, and control rod reactivity worth results were benchmarked against Serpent 2 full-core model results. Using the Serpent 2 model as reference, PARCS eigenvalue predictions were within 240 pcm, radial power was within 3% in the central region of the core, and control rod reactivity worth was within 2%. A second part reviews the current methodology used for the safety analysis of the CROCUS reactor and presents the envisioned approach for the multiphysics modeling of the reactor.

  4. The electric field in capacitively coupled RF discharges: a smooth step model that includes thermal and dynamic effects

    Science.gov (United States)

    Brinkmann, Ralf Peter

    2015-12-01

    The electric field in radio-frequency driven capacitively coupled plasmas (RF-CCP) is studied, taking thermal (finite electron temperature) and dynamic (finite electron mass) effects into account. Two dimensionless numbers are introduced, the ratios ε ={λ\\text{D}}/l of the electron Debye length {λ\\text{D}} to the minimum plasma gradient length l (typically the sheath thickness) and η ={ω\\text{RF}}/{ω\\text{pe}} of the RF frequency {ω\\text{RF}} to the electron plasma frequency {ω\\text{pe}} . Assuming both numbers small but finite, an asymptotic expansion of an electron fluid model is carried out up to quadratic order inclusively. An expression for the electric field is obtained which yields (i) the space charge field in the sheath, (ii) the generalized Ohmic and ambipolar field in the plasma, and (iii) a smooth interpolation for the transition in between. The new expression is a direct generalization of the Advanced Algebraic Approximation (AAA) proposed by the same author (2009 J. Phys. D: Appl. Phys. 42 194009), which can be recovered for η \\to 0 , and of the established Step Model (SM) by Godyak (1976 Sov. J. Plasma Phys. 2 78), which corresponds to the simultaneous limits η \\to 0 , ε \\to 0 . A comparison of the hereby proposed Smooth Step Model (SSM) with a numerical solution of the full dynamic problem proves very satisfactory.

  5. Effect of an electron beam on the subsequent pyrogenic distillation of lignin and cellulose

    Science.gov (United States)

    Metreveli, P. K.; Metreveli, A. K.; Kholodkova, E. M.; Ponomarev, A. V.

    2014-03-01

    The irradiation notably influences responsiveness of cellulose and lignin to the subsequent pyrogenic distillation though both weight and the form of samples do not change almost at doses up to 3 MGy. Decreases in overpoint of lignin and cellulose irradiated at 2.2 MGy are ~80°and ~100°, respectively. Third of condensate from cellulose and almost half from lignin are distilled-off at lower temperatures. The thermally instable compounds convertible mainly to furans via subsequent heating are forming in cellulose. Distillation of the irradiated lignin gives less tar which, however, is richer by methoxy-phenols. In distilled-off water-organic fraction the content of soluble organic compounds is increased.

  6. Recycling of Waste Acetone by Fractional Distillation

    Science.gov (United States)

    Weires, Nicholas A.; Johnston, Aubrey; Warner, Don L.; McCormick, Michael M.; Hammond, Karen; McDougal, Owen M.

    2011-01-01

    Distillation is a ubiquitous technique in the undergraduate organic chemistry curriculum; the technique dates back to ca. 3500 B.C.E. With the emergence of green chemistry in the 1990s, the importance of emphasizing responsible waste management practices for future scientists is paramount. Combining the practice of distillation with the message…

  7. Membrane distillation against a pressure difference

    NARCIS (Netherlands)

    Keulen, L.; Ham, L.V. van der; Kuipers, N.J.M.; Hanemaaijer, J.H.; Vlugt, T.J.H.; Kjelstrup, S.

    2017-01-01

    Membrane distillation is an attractive technology for production of fresh water from seawater. The MemPower® concept, studied in this work, uses available heat (86 °C) to produce pressurized water (2.2 bar and 46 °C) by membrane distillation, which again can be used to power a turbine for

  8. A literature review of coupled thermal-hydrologic-mechanical-chemical processes pertinent to the proposed high-level nuclear waste repository at Yucca Mountain

    Energy Technology Data Exchange (ETDEWEB)

    Manteufel, R.D.; Ahola, M.P.; Turner, D.R.; Chowdhury, A.H. [Southwest Research Inst., San Antonio, TX (United States). Center for Nuclear Waste Regulatory Analyses

    1993-07-01

    A literature review has been conducted to determine the state of knowledge available in the modeling of coupled thermal (T), hydrologic (H), mechanical (M), and chemical (C) processes relevant to the design and/or performance of the proposed high-level waste (HLW) repository at Yucca Mountain, Nevada. The review focuses on identifying coupling mechanisms between individual processes and assessing their importance (i.e., if the coupling is either important, potentially important, or negligible). The significance of considering THMC-coupled processes lies in whether or not the processes impact the design and/or performance objectives of the repository. A review, such as reported here, is useful in identifying which coupled effects will be important, hence which coupled effects will need to be investigated by the US Nuclear Regulatory Commission in order to assess the assumptions, data, analyses, and conclusions in the design and performance assessment of a geologic reposit``. Although this work stems from regulatory interest in the design of the geologic repository, it should be emphasized that the repository design implicitly considers all of the repository performance objectives, including those associated with the time after permanent closure. The scope of this review is considered beyond previous assessments in that it attempts with the current state-of-knowledge) to determine which couplings are important, and identify which computer codes are currently available to model coupled processes.

  9. A literature review of coupled thermal-hydrologic-mechanical-chemical processes pertinent to the proposed high-level nuclear waste repository at Yucca Mountain

    International Nuclear Information System (INIS)

    Manteufel, R.D.; Ahola, M.P.; Turner, D.R.; Chowdhury, A.H.

    1993-07-01

    A literature review has been conducted to determine the state of knowledge available in the modeling of coupled thermal (T), hydrologic (H), mechanical (M), and chemical (C) processes relevant to the design and/or performance of the proposed high-level waste (HLW) repository at Yucca Mountain, Nevada. The review focuses on identifying coupling mechanisms between individual processes and assessing their importance (i.e., if the coupling is either important, potentially important, or negligible). The significance of considering THMC-coupled processes lies in whether or not the processes impact the design and/or performance objectives of the repository. A review, such as reported here, is useful in identifying which coupled effects will be important, hence which coupled effects will need to be investigated by the US Nuclear Regulatory Commission in order to assess the assumptions, data, analyses, and conclusions in the design and performance assessment of a geologic reposit''. Although this work stems from regulatory interest in the design of the geologic repository, it should be emphasized that the repository design implicitly considers all of the repository performance objectives, including those associated with the time after permanent closure. The scope of this review is considered beyond previous assessments in that it attempts with the current state-of-knowledge) to determine which couplings are important, and identify which computer codes are currently available to model coupled processes

  10. Operation and Design of Diabatic Distillation Processes

    DEFF Research Database (Denmark)

    Bisgaard, Thomas

    design of the heat-integrated distillation column configurations is challenging as a result of the increased number of decision variables compared to the CDiC. Finally, themodel is implemented in Matlab and a database of the considered configurations, case studies, pure component properties, and binary......Diabatic operation of a distillation column implies that heat is exchanged in one or more stages in the column. The most common way of realising diabatic operation is by internal heat integration resulting in a heat-integrated distillation column (HIDiC). When operating the rectifying section...... at a higher pressure, a driving forcefor transferring heat from the rectifying section to the stripping section is achieved. As a result, the condenser and reboiler duties can be significantly reduced. For two-product distillation, the HIDiC is a favourable alternative to the conventional distillation column...

  11. Numerical research on the neutronic/thermal-hydraulic/mechanical coupling characteristics of the optimized helium cooled solid breeder blanket for CFETR

    Energy Technology Data Exchange (ETDEWEB)

    Cui, Shijie; Zhang, Dalin, E-mail: dlzhang@mail.xjtu.edu.cn; Cheng, Jie; Tian, Wenxi; Su, G.H.

    2017-01-15

    As one of the candidate tritium breeding blankets for Chinese Fusion Engineering Test Reactor (CFETR), a conceptual structure of the helium cooled solid breeder blanket has recently been proposed. The neutronic, thermal-hydraulic and mechanical characteristics of the blanket directly affect its tritium breeding and safety performance. Therefore, neutronic/thermal-hydraulic/mechanical coupling analyses are of vital importance for a reliable blanket design. In this work, first, three-dimensional neutronics analysis and optimization of the typical outboard equatorial blanket module (No. 12) were performed for the comprehensive optimal scheme. Then, thermal and fluid dynamic analyses of the scheme under both normal and critical conditions were performed and coupled with the previous neutronic calculation results. With thermal-hydraulic boundaries, thermo-mechanical analyses of the structure materials under normal, critical and blanket over-pressurization conditions were carried out. In addition, several parametric sensitivity studies were also conducted to investigate the influences of the main parameters on the blanket temperature distributions. In this paper, the coupled analyses verify the reasonability of the optimized conceptual design preliminarily and can provide an important reference for the further analysis and optimization design of the CFETR helium cooled solid breeder blanket.

  12. A new coupling of the 3D thermal-hydraulic code THYC and the thermo-mechanical code CYRANO3 for PWR calculations

    Energy Technology Data Exchange (ETDEWEB)

    Marguet, S.D. [Electricite de France (EDF), 92 - Clamart (France)

    1997-12-31

    Among all parameters, the fuel temperature has a significant influence on the reactivity of the core, because of the Doppler effect on cross-sections. Most neutronic codes use a straightforward method to calculate an average fuel temperature used in their specific feed-back models. For instance, EDF`s neutronic code COCCINELLE uses the Rowland`s formula using the temperatures of the center and the surface of the pellet. COCCINELLE is coupled to the 3D thermal-hydraulic code THYC with calculates TDoppler with is standard thermal model. In order to improve the accuracy of such calculations, we have developed the coupling of our two latest codes in thermal-hydraulics (THYC) and thermo-mechanics (CYRANO3). THYC calculates two-phase flows in pipes or rod bundles and is used for transient calculations such as steam-line break, boron dilution accidents, DNB predictions, steam generator and condenser studies. CYRANO3 calculates most of the phenomena that take place in the fuel such as: 1) heat transfer induced by nuclear power; 2) thermal expansion of the fuel and the cladding; 3) release of gaseous fission`s products; 4) mechanical interaction between the pellet and the cladding. These two codes are now qualified in their own field and the coupling, using Parallel Virtual Machine (PVM) libraries customized in an home-made-easy-to-use package called CALCIUM, has been validated on `low` configurations (no thermal expansion, constant thermal characteristics) and used on accidental transients such as rod ejection and loss of coolant accident. (K.A.) 7 refs.

  13. A new coupling of the 3D thermal-hydraulic code THYC and the thermo-mechanical code CYRANO3 for PWR calculations

    International Nuclear Information System (INIS)

    Marguet, S.D.

    1997-01-01

    Among all parameters, the fuel temperature has a significant influence on the reactivity of the core, because of the Doppler effect on cross-sections. Most neutronic codes use a straightforward method to calculate an average fuel temperature used in their specific feed-back models. For instance, EDF's neutronic code COCCINELLE uses the Rowland's formula using the temperatures of the center and the surface of the pellet. COCCINELLE is coupled to the 3D thermal-hydraulic code THYC with calculates TDoppler with is standard thermal model. In order to improve the accuracy of such calculations, we have developed the coupling of our two latest codes in thermal-hydraulics (THYC) and thermo-mechanics (CYRANO3). THYC calculates two-phase flows in pipes or rod bundles and is used for transient calculations such as steam-line break, boron dilution accidents, DNB predictions, steam generator and condenser studies. CYRANO3 calculates most of the phenomena that take place in the fuel such as: 1) heat transfer induced by nuclear power; 2) thermal expansion of the fuel and the cladding; 3) release of gaseous fission's products; 4) mechanical interaction between the pellet and the cladding. These two codes are now qualified in their own field and the coupling, using Parallel Virtual Machine (PVM) libraries customized in an home-made-easy-to-use package called CALCIUM, has been validated on 'low' configurations (no thermal expansion, constant thermal characteristics) and used on accidental transients such as rod ejection and loss of coolant accident. (K.A.)

  14. A Novel 3D Thermal Impedance Model for High Power Modules Considering Multi-layer Thermal Coupling and Different Heating/Cooling Conditions

    DEFF Research Database (Denmark)

    Bahman, Amir Sajjad; Ma, Ke; Blaabjerg, Frede

    2015-01-01

    accurate temperature estimation either vertically or horizontally inside the power devices is still hard to identify. This paper investigates the thermal behavior of high power module in various operating conditions by means of Finite Element Method (FEM). A novel 3D thermal impedance network considering......Thermal management of power electronic devices is essential for reliable performance especially at high power levels. One of the most important activities in the thermal management and reliability improvement is acquiring the temperature information in critical points of the power module. However...

  15. Characteristics of a laser beam produced by using thermal lensing effect compensation in a fiber-coupled laser-diode-pumped Nd:YAG ceramic laser

    International Nuclear Information System (INIS)

    Kim, Duck-Lae; Kim, Byung-Tai

    2010-01-01

    The characteristics of a laser beam produced by using thermal lensing effect compensation in a fiber-coupled laser-diode Nd:YAG ceramic laser were investigated. The thermal lensing effect was compensated for by using a compensator, which was 25 mm away from the laser rod, with a focal length of 30 mm and an effective clear aperture of 22 mm. Using a compensator, the divergence and the beam propagation factor M 2 of the output beam were 5.5 mrad and 2.4, respectively, under a pump power of 12W. The high-frequency components in the compensated laser beam were removed.

  16. Coupling Monte Carlo simulations with thermal analysis for correcting microdosimetric spectra from a novel micro-calorimeter

    Science.gov (United States)

    Fathi, K.; Galer, S.; Kirkby, K. J.; Palmans, H.; Nisbet, A.

    2017-11-01

    The high uncertainty in the Relative Biological Effectiveness (RBE) values of particle therapy beam, which are used in combination with the quantity absorbed dose in radiotherapy, together with the increase in the number of particle therapy centres worldwide necessitate a better understating of the biological effect of such modalities. The present novel study is part of performance testing and development of a micro-calorimeter based on Superconducting QUantum Interference Devices (SQUIDs). Unlike other microdosimetric detectors that are used for investigating the energy distribution, this detector provides a direct measurement of energy deposition at the micrometre scale, that can be used to improve our understanding of biological effects in particle therapy application, radiation protection and environmental dosimetry. Temperature rises of less than 1μK are detectable and when combined with the low specific heat capacity of the absorber at cryogenic temperature, extremely high energy deposition sensitivity of approximately 0.4 eV can be achieved. The detector consists of 3 layers: tissue equivalent (TE) absorber, superconducting (SC) absorber and silicon substrate. Ideally all energy would be absorbed in the TE absorber and heat rise in the superconducting layer would arise due to heat conduction from the TE layer. However, in practice direct particle absorption occurs in all 3 layers and must be corrected for. To investigate the thermal behaviour within the detector, and quantify any possible correction, particle tracks were simulated employing Geant4 (v9.6) Monte Carlo simulations. The track information was then passed to the COMSOL Multiphysics (Finite Element Method) software. The 3D heat transfer within each layer was then evaluated in a time-dependent model. For a statistically reliable outcome, the simulations had to be repeated for a large number of particles. An automated system has been developed that couples Geant4 Monte Carlo output to COMSOL for

  17. A Natural Analogue for Thermal-Hydrological-Chemical Coupled Processes at the Proposed Nuclear Waste Repository at Yucca Mountain, Nevada

    International Nuclear Information System (INIS)

    Bill Carey; Gordon Keating; Peter C. Lichtner

    1999-01-01

    Dike and sill complexes that intruded tuffaceous host rocks above the water table are suggested as natural analogues for thermal-hydrologic-chemical (THC) processes at the proposed nuclear waste repository at Yucca Mountain, Nevada. Scoping thermal-hydrologic calculations of temperature and saturation profiles surrounding a 30-50 m wide intrusion suggest that boiling conditions could be sustained at distances of tens of meters from the intrusion for several thousand years. This time scale for persistence of boiling is similar to that expected for the Yucca Mountain repository with moderate heat loading. By studying the hydrothermal alteration of the tuff host rocks surrounding the intrusions, insight and relevant data can be obtained that apply directly to the Yucca Mountain repository and can shed light on the extent and type of alteration that should be expected. Such data are needed to bound and constrain model parameters used in THC simulations of the effect of heat produced by the waste on the host rock and to provide a firm foundation for assessing overall repository performance. One example of a possible natural analogue for the repository is the Paiute Ridge intrusive complex located on the northeastern boundary of the Nevada Test Site, Nye County, Nevada. The complex consists of dikes and sills intruded into a partially saturated tuffaceous host rock that has stratigraphic sequences that correlate with those found at Yucca Mountain. The intrusions were emplaced at a depth of several hundred meters below the surface, similar to the depth of the proposed repository. The tuffaceous host rock surrounding the intrusions is hydrothermally altered to varying extents depending on the distance from the intrusions. The Paiute Ridge intrusive complex thus appears to be an ideal natural analogue of THC coupled processes associated with the Yucca Mountain repository. It could provide much needed physical and chemical data for understanding the influence of heat

  18. Fenomena Kerak Dalam Desalinasi Dengan Multi Stage Flash Distillation (Msf)

    OpenAIRE

    Alimah, Siti

    2006-01-01

    SCALING PHENOMENA IN DESALINATION WITH MULTI STAGE FLASH DISTILLATION (MSF). Assessment of scaling phenomena in MSF desalination has been carried out. Scale is one of predominantly problem in multi stage flash (MSF) desalination installation. The main types of scale in MSF are carbonat calcium (CaC03), hydroxide magnesium (Mg(OH)2) dan sulphate calcium (CaS04). CaC03 dan Mg(OH)2 scales result from the thermal decomposition of bicarbonate ion, however sulphate calcium scale result from reactio...

  19. Concentration of lignocellulosic hydrolyzates by solar membrane distillation.

    Science.gov (United States)

    Zhang, Lin; Wang, Yafei; Cheng, Li-Hua; Xu, Xinhua; Chen, Huanlin

    2012-11-01

    A small solar energy collector was run to heat lignocellulosic hydrolyzates through an exchanger, and the heated hydrolyzate was concentrated by vacuum membrane distillation (VMD). Under optimal conditions of velocity of 1.0m/s and 65°C, glucose rejection was 99.5% and the flux was 8.46Lm(-2)h(-1). Fermentation of the concentrated hydrolyzate produced 2.64 times the amount of ethanol as fermentation using the original hydrolyzate. The results of this work indicated the possibility to decrease the thermal energy consumption of lignocellulosic ethanol through using VMD. Copyright © 2012 Elsevier Ltd. All rights reserved.

  20. Comparison of Citronella Oil Extraction Methods from Cymbopogon nardus Grass by Ohmic-heated Hydro-distillation, Hydro-Distillation, and Steam Distillation

    OpenAIRE

    Muhammad Hazwan Hamzah; Hasfalina Che Man; Zurina Zainal Abidin; Hishamuddin Jamaludin

    2013-01-01

    A proposed method for citronella oil extraction was developed with the application of ohmic heated hydro-distillation. The objective was to compare the performance of three different extraction methods, viz. ohmic heated hydro-distillation, hydro-distillation, and steam distillation. The maximum amount of extracted oil yield by ohmic heated hydro-distillation was 7.64 mL/kWh as compared to hydro-distillation and steam distillation methods that resulted oil yields of 3.87 mL/kWh and 1.69 mL/kW...

  1. Fractional distillation of acid contaminants from sevoflurane.

    Science.gov (United States)

    Laster, M J; Eger, E I; Cherry, W R; Gong, D

    2000-10-01

    On two occasions, sevoflurane distributed for clinical practice has been found to be contaminated with compounds thought to include hydrogen fluoride (HF) and silicon tetrafluoride (SiF(4)). Both compounds can produce pulmonary injury. However, injury would require fractional distillation of the compounds during the course of sevoflurane vaporization. We hypothesized that such distillation would occur and that the compounds would vaporize more rapidly than would sevoflurane. Thus, we tested whether fractional distillation occurs during vaporization of sevoflurane containing HF or SiF(4), or from sevoflurane containing HF converted to other compounds by contact with glass. Vaporization of distilled 65%-99% of these compounds, SiF(4) distilling most rapidly, HF (converted to other acidic compounds, including SiF(4)) distilling nearly as rapidly, and HF slowest. Nuclear magnetic resonance studies indicated that HF interaction with glass changed all HF to three other compounds, one being SiF(4) and the others being unknown. HF and SiF4 distill from sevoflurane more rapidly than sevoflurane is vaporized. Measurement of acidity after sevoflurane administration may not reveal a previous presence of such contaminants.

  2. The Coupled Thermal and Mechanical Influence on a Glassy Thermoplastic Polyamide: Nylon 6, 6 Under Vibro-Creep

    Science.gov (United States)

    Liu, Z. Y.; Beniwal, S.; Jenkins, C. H. M.; Winter, R. M.

    2004-09-01

    The vibro-creep behavior of pure Nylon 6, 6 samples subjected to tensile-tensile cyclic loading conditions within the linear elastic region (25% of yield stress at 30 °C) was studied by examining their viscoelastic response. All tests were performed at controlled temperatures, and humidity was kept as low as possible. The test protocol included three frequencies and two amplitudes. The results from all tests show that vibro-creep behavior may be divided into three stages: (a) Primary thermally dominated regime (b) Transition or coupled regime (c) Tertiary damage dominated regime. The sample temperature was observed to rise 2 2.5 °C during the cyclic loading process, which significantly contributed to the early mechanical response of the sample. Two sets of quasi-static tests were completed at 30 °C and 32.5 °C to give references for vibro-creep effects. The relationship between engineering strain for the cyclic loading process (at 30 °C) and the quasi-static creep at 32.5 °C suggests the boundaries for different mechanisms dominating the vibro-creep behavior. This is also evident from the postmortem analyses of sample surfaces using AFM. Both the exterior sample surfaces and the interior cross-sectional surfaces were checked for the evolving damage. Mean roughness and dimensions of the cracks were measured in the damaged samples. Cracks of dimensions 2 4 μm on the exterior surface and 1 2 μm on the interior cross-sectional surface were observed in pure Nylon 6, 6 samples subjected up to 2 × 106 cycles.

  3. Thermal radiation transfer calculations in combustion fields using the SLW model coupled with a modified reference approach

    Science.gov (United States)

    Darbandi, Masoud; Abrar, Bagher

    2018-01-01

    The spectral-line weighted-sum-of-gray-gases (SLW) model is considered as a modern global model, which can be used in predicting the thermal radiation heat transfer within the combustion fields. The past SLW model users have mostly employed the reference approach to calculate the local values of gray gases' absorption coefficient. This classical reference approach assumes that the absorption spectra of gases at different thermodynamic conditions are scalable with the absorption spectrum of gas at a reference thermodynamic state in the domain. However, this assumption cannot be reasonable in combustion fields, where the gas temperature is very different from the reference temperature. Consequently, the results of SLW model incorporated with the classical reference approach, say the classical SLW method, are highly sensitive to the reference temperature magnitude in non-isothermal combustion fields. To lessen this sensitivity, the current work combines the SLW model with a modified reference approach, which is a particular one among the eight possible reference approach forms reported recently by Solovjov, et al. [DOI: 10.1016/j.jqsrt.2017.01.034, 2017]. The combination is called "modified SLW method". This work shows that the modified reference approach can provide more accurate total emissivity calculation than the classical reference approach if it is coupled with the SLW method. This would be particularly helpful for more accurate calculation of radiation transfer in highly non-isothermal combustion fields. To approve this, we use both the classical and modified SLW methods and calculate the radiation transfer in such fields. It is shown that the modified SLW method can almost eliminate the sensitivity of achieved results to the chosen reference temperature in treating highly non-isothermal combustion fields.

  4. Structural Decoupling and Disturbance Rejection in a Distillation Column

    DEFF Research Database (Denmark)

    Bahar, Mehrdad; Jantzen, Jan; Commault, C.

    1996-01-01

    Introduction, distillation column model, input-output decoupling, disturbance rejection, concluding remarks, references.......Introduction, distillation column model, input-output decoupling, disturbance rejection, concluding remarks, references....

  5. Three Mile Island Unit 1 Main Steam Line Break Three-Dimensional Neutronics/Thermal-Hydraulics Analysis: Application of Different Coupled Codes

    International Nuclear Information System (INIS)

    D'Auria, Francesco; Moreno, Jose Luis Gago; Galassi, Giorgio Maria; Grgic, Davor; Spadoni, Antonino

    2003-01-01

    A comprehensive analysis of the double ended main steam line break (MSLB) accident assumed to occur in the Babcock and Wilcox Three Mile Island Unit 1 (TMI-1) has been carried out at the Dipartimento di Ingegneria Meccanica, Nucleare e della Produzione of the University of Pisa, Italy, in cooperation with the University of Zagreb, Croatia. The overall activity has been completed within the framework of the participation in the Organization for Economic Cooperation and Development-Committee on the Safety of Nuclear Installations-Nuclear Science Committee pressurized water reactor MSLB benchmark.Thermal-hydraulic system codes (various versions of Relap5), three-dimensional (3-D) neutronics codes (Parcs, Quabbox, and Nestle), and one subchannel code (Cobra) have been adopted for the analysis. Results from the following codes (or code versions) are assumed as reference:1. Relap5/mod3.2.2, beta version, coupled with the 3-D neutron kinetics Parcs code parallel virtual machine (PVM) coupling2. Relap5/mod3.2.2, gamma version, coupled with the 3-D neutron kinetics Quabbox code (direct coupling)3. Relap5/3D code coupled with the 3-D neutron kinetics Nestle code.The influence of PVM and of direct coupling is also discussed.Boundary and initial conditions of the system, including those relevant to the fuel status, have been supplied by Pennsylvania State University in cooperation with GPU Nuclear Corporation (the utility, owner of TMI) and the U.S. Nuclear Regulatory Commission. The comparison among the results obtained by adopting the same thermal-hydraulic nodalization and the coupled code version is discussed in this paper.The capability of the control rods to recover the accident has been demonstrated in all the cases as well as the capability of all the codes to predict the time evolution of the assigned transient. However, one stuck control rod caused some 'recriticality' or 'return to power' whose magnitude is largely affected by boundary and initial conditions

  6. Elementary introduction into thermal desalination of saline waters

    International Nuclear Information System (INIS)

    Froehner, K.R.

    1979-01-01

    The principle of thermal conversion of saline waters into potable water are described from an elementary point of view in an easy understandable manner, covering distillation, submerged coil evaporation, flash evaporation, multiple effect distillation, vapour compression, and solar distillation in simple solar stills. (orig.)

  7. Coupled calculation of the radiological release and the thermal-hydraulic behavior of a 3-loop PWR after a SGTR by means of the code RELAP5

    Energy Technology Data Exchange (ETDEWEB)

    Van Hove, W.; Van Laeken, K.; Bartsoen, L. [Belgatom, Brussels (Belgium)] [and others

    1995-09-01

    To enable a more realistic and accurate calculation of the radiological consequences of a SGTR, a fission product transport model was developed. As the radiological releases strongly depend on the thermal-hydraulic transient, the model was included in the RELAP5 input decks of the Belgian NPPs. This enables the coupled calculation of the thermal-hydraulic transient and the radiological release. The fission product transport model tracks the concentration of the fission products in the primary circuit, in each of the SGs as well as in the condenser. This leads to a system of 6 coupled, first order ordinary differential equations with time dependent coefficients. Flashing, scrubbing, atomisation and dry out of the break flow are accounted for. Coupling with the thermal-hydraulic calculation and correct modelling of the break position enables an accurate calculation of the mixture level above the break. Pre- and post-accident spiking in the primary circuit are introduced. The transport times in the FW-system and the SG blowdown system are also taken into account, as is the decontaminating effect of the primary make-up system and of the SG blowdown system. Physical input parameters such as the partition coefficients, half life times and spiking coefficients are explicitly introduced so that the same model can be used for iodine, caesium and noble gases.

  8. Modeling of steam distillation mechanism during steam injection process using artificial intelligence.

    Science.gov (United States)

    Daryasafar, Amin; Ahadi, Arash; Kharrat, Riyaz

    2014-01-01

    Steam distillation as one of the important mechanisms has a great role in oil recovery in thermal methods and so it is important to simulate this process experimentally and theoretically. In this work, the simulation of steam distillation is performed on sixteen sets of crude oil data found in the literature. Artificial intelligence (AI) tools such as artificial neural network (ANN) and also adaptive neurofuzzy interference system (ANFIS) are used in this study as effective methods to simulate the distillate recoveries of these sets of data. Thirteen sets of data were used to train the models and three sets were used to test the models. The developed models are highly compatible with respect to input oil properties and can predict the distillate yield with minimum entry. For showing the performance of the proposed models, simulation of steam distillation is also done using modified Peng-Robinson equation of state. Comparison between the calculated distillates by ANFIS and neural network models and also equation of state-based method indicates that the errors of the ANFIS model for training data and test data sets are lower than those of other methods.

  9. Validation of Agent Based Distillation Movement Algorithms

    National Research Council Canada - National Science Library

    Gill, Andrew

    2003-01-01

    Agent based distillations (ABD) are low-resolution abstract models, which can be used to explore questions associated with land combat operations in a short period of time Movement of agents within the EINSTein and MANA ABDs...

  10. Efficient entanglement distillation without quantum memory.

    Science.gov (United States)

    Abdelkhalek, Daniela; Syllwasschy, Mareike; Cerf, Nicolas J; Fiurášek, Jaromír; Schnabel, Roman

    2016-05-31

    Entanglement distribution between distant parties is an essential component to most quantum communication protocols. Unfortunately, decoherence effects such as phase noise in optical fibres are known to demolish entanglement. Iterative (multistep) entanglement distillation protocols have long been proposed to overcome decoherence, but their probabilistic nature makes them inefficient since the success probability decays exponentially with the number of steps. Quantum memories have been contemplated to make entanglement distillation practical, but suitable quantum memories are not realised to date. Here, we present the theory for an efficient iterative entanglement distillation protocol without quantum memories and provide a proof-of-principle experimental demonstration. The scheme is applied to phase-diffused two-mode-squeezed states and proven to distil entanglement for up to three iteration steps. The data are indistinguishable from those that an efficient scheme using quantum memories would produce. Since our protocol includes the final measurement it is particularly promising for enhancing continuous-variable quantum key distribution.

  11. Distillation modeling for a uranium refining process

    International Nuclear Information System (INIS)

    Westphal, B.R.

    1996-01-01

    As part of the spent fuel treatment program at Argonne National Laboratory, a vacuum distillation process is being employed for the recovery of uranium following an electrorefining process. Distillation of a salt electrolyte, containing a eutectic mixture of lithium and potassium chlorides, from uranium is achieved by a simple batch operation and is termed open-quotes cathode processingclose quotes. The incremental distillation of electrolyte salt will be modeled by an equilibrium expression and on a molecular basis since the operation is conducted under moderate vacuum conditions. As processing continues, the two models will be compared and analyzed for correlation with actual operating results. Possible factors that may contribute to aberrations from the models include impurities at the vapor-liquid boundary, distillate reflux, anomalous pressure gradients, and mass transport phenomena at the evaporating surface. Ultimately, the purpose of either process model is to enable the parametric optimization of the process

  12. Coupled transfers; Transferts couples

    Energy Technology Data Exchange (ETDEWEB)

    Nicolas, X.; Lauriat, G.; Jimenez-Rondan, J. [Universite de Marne-la-Vallee, Lab. d' Etudes des Transferts d' Energie et de Matiere (LETEM), 77 (France); Bouali, H.; Mezrhab, A. [Faculte des Sciences, Dept. de Physique, Lab. de Mecanique et Energetique, Oujda (Morocco); Abid, C. [Ecole Polytechnique Universitaire de Marseille, IUSTI UMR 6595, 13 Marseille (France); Stoian, M.; Rebay, M.; Lachi, M.; Padet, J. [Faculte des Sciences, Lab. de Thermomecanique, UTAP, 51 - Reims (France); Mladin, E.C. [Universitaire Polytechnique Bucarest, Faculte de Genie Mecanique, Bucarest (Romania); Mezrhab, A. [Faculte des Sciences, Lab. de Mecanique et Energetique, Dept. de Physique, Oujda (Morocco); Abid, C.; Papini, F. [Ecole Polytechnique, IUSTI, 13 - Marseille (France); Lorrette, C.; Goyheneche, J.M.; Boechat, C.; Pailler, R. [Laboratoire des Composites ThermoStructuraux, UMR 5801, 33 - Pessac (France); Ben Salah, M.; Askri, F.; Jemni, A.; Ben Nasrallah, S. [Ecole Nationale d' Ingenieurs de Monastir, Lab. d' Etudes des Systemes Thermiques et Energetiques (Tunisia); Grine, A.; Desmons, J.Y.; Harmand, S. [Laboratoire de Mecanique et d' Energetique, 59 - Valenciennes (France); Radenac, E.; Gressier, J.; Millan, P. [ONERA, 31 - Toulouse (France); Giovannini, A. [Institut de Mecanique des Fluides de Toulouse, 31 (France)

    2005-07-01

    This session about coupled transfers gathers 30 articles dealing with: numerical study of coupled heat transfers inside an alveolar wall; natural convection/radiant heat transfer coupling inside a plugged and ventilated chimney; finite-volume modeling of the convection-conduction coupling in non-stationary regime; numerical study of the natural convection/radiant heat transfer coupling inside a partitioned cavity; modeling of the thermal conductivity of textile reinforced composites: finite element homogenization on a full periodical pattern; application of the control volume method based on non-structured finite elements to the problems of axisymmetrical radiant heat transfers in any geometries; modeling of convective transfers in transient regime on a flat plate; a conservative method for the non-stationary coupling of aero-thermal engineering codes; measurement of coupled heat transfers (forced convection/radiant transfer) inside an horizontal duct; numerical simulation of the combustion of a water-oil emulsion droplet; numerical simulation study of heat and mass transfers inside a reactor for nano-powders synthesis; reduction of a combustion and heat transfer model of a direct injection diesel engine; modeling of heat transfers inside a knocking operated spark ignition engine; heat loss inside an internal combustion engine, thermodynamical and flamelet model, composition effects of CH{sub 4}H{sub 2} mixtures; experimental study and modeling of the evolution of a flame on a solid fuel; heat transfer for laminar subsonic jet of oxygen plasma impacting an obstacle; hydrogen transport through a A-Si:H layer submitted to an hydrogen plasma: temperature effects; thermal modeling of the CO{sub 2} laser welding of a magnesium alloy; radiant heat transfer inside a 3-D environment: application of the finite volume method in association with the CK model; optimization of the infrared baking of two types of powder paints; optimization of the emission power of an infrared

  13. Multipartite secret key distillation and bound entanglement

    International Nuclear Information System (INIS)

    Augusiak, Remigiusz; Horodecki, Pawel

    2009-01-01

    Recently it has been shown that quantum cryptography beyond pure entanglement distillation is possible and a paradigm for the associated protocols has been established. Here we systematically generalize the whole paradigm to the multipartite scenario. We provide constructions of new classes of multipartite bound entangled states, i.e., those with underlying twisted Greenberger-Horne-Zeilinger (GHZ) structure and nonzero distillable cryptographic key. We quantitatively estimate the key from below with the help of the privacy squeezing technique.

  14. Evaluating the performance of coupled snow-soil models in SURFEXv8 to simulate the permafrost thermal regime at a high Arctic site

    Science.gov (United States)

    Barrere, Mathieu; Domine, Florent; Decharme, Bertrand; Morin, Samuel; Vionnet, Vincent; Lafaysse, Matthieu

    2017-09-01

    Climate change projections still suffer from a limited representation of the permafrost-carbon feedback. Predicting the response of permafrost temperature to climate change requires accurate simulations of Arctic snow and soil properties. This study assesses the capacity of the coupled land surface and snow models ISBA-Crocus and ISBA-ES to simulate snow and soil properties at Bylot Island, a high Arctic site. Field measurements complemented with ERA-Interim reanalyses were used to drive the models and to evaluate simulation outputs. Snow height, density, temperature, thermal conductivity and thermal insulance are examined to determine the critical variables involved in the soil and snow thermal regime. Simulated soil properties are compared to measurements of thermal conductivity, temperature and water content. The simulated snow density profiles are unrealistic, which is most likely caused by the lack of representation in snow models of the upward water vapor fluxes generated by the strong temperature gradients within the snowpack. The resulting vertical profiles of thermal conductivity are inverted compared to observations, with high simulated values at the bottom of the snowpack. Still, ISBA-Crocus manages to successfully simulate the soil temperature in winter. Results are satisfactory in summer, but the temperature of the top soil could be better reproduced by adequately representing surface organic layers, i.e., mosses and litter, and in particular their water retention capacity. Transition periods (soil freezing and thawing) are the least well reproduced because the high basal snow thermal conductivity induces an excessively rapid heat transfer between the soil and the snow in simulations. Hence, global climate models should carefully consider Arctic snow thermal properties, and especially the thermal conductivity of the basal snow layer, to perform accurate predictions of the permafrost evolution under climate change.

  15. Investigation of Future Thermal Comforts in a Tropical Megacity Using Coupling of Energy Balance Model and Large Eddy Simulation

    Science.gov (United States)

    Sueishi, T.; Yucel, M.; Ashie, Y.; Varquez, A. C. G.; Inagaki, A.; Darmanto, N. S.; Nakayoshi, M.; Kanda, M.

    2017-12-01

    Recently, temperature in urban areas continue to rise as an effect of climate change and urbanization. Specifically, Asian megacities are projected to expand rapidly resulting to serious in the future atmospheric environment. Thus, detailed analysis of urban meteorology for Asian megacities is needed to prescribe optimum against these negative climate modifications. A building-resolving large eddy simulation (LES) coupled with an energy balance model is conducted for a highly urbanized district in central Jakarta on typical daytime hours. Five cases were considered; case 1 utilizes present urban scenario and four cases representing different urban configurations in 2050. The future configurations were based on representative concentration pathways (RCP) and shared socio-economic pathways (SSP). Building height maps and land use maps of simulation domains are shown in the attached figure (top). Case 1 3 focuses on the difference of future scenarios. Case 1 represents current climatic and urban conditions, case 2 and 3 was an idealized future represented by RCP2.6/SSP1 and RCP8.5/SSP3, respectively. More complex urban morphology was applied in case 4, vegetation and building area were changed in case 5. Meteorological inputs and anthropogenic heat emission (AHE) were calculated using Weather Research and Forecasting (WRF) model (Varquez et al [2017]). Sensible and latent heat flux from surfaces were calculated using an energy balance model (Ashie et al [2011]), with considers multi-reflection, evapotranspiration and evaporation. The results of energy balance model (shown in the middle line of figure), in addition to WRF outputs, were used as input into the PArallelized LES Model (PALM) (Raasch et al [2001]). From standard new effective temperature (SET*) which included the effects of temperature, wind speed, humidity and radiation, thermal comfort in urban area was evaluated. SET* contours at 1 m height are shown in the bottom line of the figure. Extreme climate

  16. Water solar distiller productivity enhancement using concentrating solar water heater and phase change material (PCM)

    OpenAIRE

    Miqdam T. Chaichan; Hussein A. Kazem

    2015-01-01

    This paper investigates usage of thermal energy storage extracted from concentrating solar heater for water distillation. Paraffin wax selected as a suitable phase change material, and it was used for storing thermal energy in two different insulated treasurers. The paraffin wax is receiving hot water from concentrating solar dish. This solar energy stored in PCM as latent heat energy. Solar energy stored in a day time with a large quantity, and some heat retrieved for later use. Water’s temp...

  17. 7 CFR 160.8 - Steam distilled wood turpentine.

    Science.gov (United States)

    2010-01-01

    ... STANDARDS FOR NAVAL STORES General § 160.8 Steam distilled wood turpentine. The designation “steam distilled wood turpentine” shall refer to the kind of spirits of turpentine obtained by steam distillation from... 7 Agriculture 3 2010-01-01 2010-01-01 false Steam distilled wood turpentine. 160.8 Section 160.8...

  18. Thermal Desalination using MEMS and Salinity-Gradient Solar Pond Technology

    Science.gov (United States)

    Lu, H.; Walton, J. C.; Hein, H.

    2002-08-01

    MEMS (multi-effect, multi-stage) flash desalination (distillation) driven by thermal energy derived from a salinity-gradient solar pond is investigated in this study for the purpose of improving the thermodynamic efficiency and economics of this technology. Three major tasks are performed: (1) a MEMS unit is tested under various operating conditions at the El Paso Solar Pond site; (2) the operation and maintenance procedures of the salinity-gradient solar pond coupled with the MEMS operation is studied; and (3) previous test data on a 24-stage, falling-film flash distillation unit (known as the Spinflash) is analyzed and compared with the performance of the MEMS unit. The data and information obtained from this investigation is applicable to a variety of thermal desalination processes using other solar options and/or waste heat.

  19. Development of the coupled 'system thermal-hydraulics, 3D reactor kinetics, and hot channel' analysis capability of the MARS code

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, J. J.; Chung, B. D.; Lee, W.J

    2005-02-01

    The subchannel analysis capability of the MARS 3D module has been improved. Especially, the turbulent mixing and void drift models for flow mixing phenomena in rod bundles have been assessed using some well-known rod bundle test data. Then, the subchannel analysis feature was combined to the existing coupled 'system Thermal-Hydraulics (T/H) and 3D reactor kinetics' calculation capability of MARS. These features allow the coupled 'system T/H, 3D reactor kinetics, and hot channel' analysis capability and, thus, realistic simulations of hot channel behavior as well as global system T/H behavior. In this report, the MARS code features for the coupled analysis capability are described first. The code modifications relevant to the features are also given. Then, a coupled analysis of the Main Steam Line Break (MSLB) is carried out for demonstration. The results of the coupled calculations are very reasonable and realistic, and show these methods can be used to reduce the over-conservatism in the conventional safety analysis.

  20. The influence of starch oxidization and aluminate coupling agent on interfacial interaction, rheological behavior, mechanical and thermal properties of poly(propylene carbonate)/starch blends

    Science.gov (United States)

    Jiang, Guo; Zhang, Shui-Dong; Huang, Han-Xiong; The Key Laboratory of Polymer Processing Engineering of the Ministry of Education Team

    Poly(propylene carbonate) (PPC) is a kind of new biodegradable polymer that is synthesized by copolymerization of propylene oxide and carbon dioxide. In this work, PPC end-capped with maleic anhydride (PPCMA)/thermoplastic starch (TPS), PPCMA/thermoplastic oxidized starch (TPOS) and PPCMA/AL-TPOS (TPOS modified by aluminate coupling agent) blends were prepared by melt blending to improve its thermal and mechanical properties. FTIR results showed that there existed hydrogen-bonding interaction between PPCMA and starch. SEM observation revealed that the compatibility between PPCMA and TPOS was improved by the oxidation of starch. The enhanced interfacial interactions between PPCMA and TPOS led to a better performance of PPC blends such as storage modulus (G'), loss modulus (G''), complex viscosity (η*), tensile strength and thermal properties. Furthermore, the modification of TPOS by aluminate coupling agent (AL) facilitated the dispersion of oxidized starch in PPC matrix, and resulted in increasing the tensile strength and thermal stability. National Natural Science Foundation of China, National Science Fund of Guangdong Province.

  1. Statistical safety evaluation of BWR turbine trip scenario using coupled neutron kinetics and thermal hydraulics analysis code SKETCH-INS/TRACE5.0

    International Nuclear Information System (INIS)

    Ichikawa, Ryoko; Masuhara, Yasuhiro; Kasahara, Fumio

    2012-01-01

    The Best Estimate Plus Uncertainty (BEPU) method has been prepared for the regulatory cross-check analysis at Japan Nuclear Energy Safety Organization (JNES) on base of the three-dimensional neutron-kinetics/thermal-hydraulics coupled code SKETCH-INS/TRACE5.0. In the preparation, TRACE5.0 is verified against the large-scale thermal-hydraulic tests carried out with NUPEC facility. These tests were focused on the pressure drop of steam-liquid two phase flow and void fraction distribution. From the comparison of the experimental data with other codes (RELAP5/MOD3.3 and TRAC-BF1), TRACE5.0 was judged better than other codes. It was confirmed that TRACE5.0 has high reliability for thermal hydraulics behavior and are used as a best-estimate code for the statistical safety evaluation. Next, the coupled code SKETCH-INS/TRACE5.0 was applied to turbine trip tests performed at the Peach Bottom-2 BWR4 Plant. The turbine trip event shows the rapid power peak due to the voids collapse with the pressure increase. The analyzed peak value of core power is better simulated than the previous version SKETCH-INS/TRAC-BF1. And the statistical safety evaluation using SKETCH-INS/TRACE5.0 was applied to the loss of load transient for examining the influence of the choice of sampling method. (author)

  2. Coupling of Mechanical Behavior of Lithium Ion Cells to Electrochemical-Thermal (ECT) Models for Battery Crush

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Chao; Santhanagopalan, Shriram; Pesaran, Ahmad; Sahraei, Elham; Wierzbicki, Tom

    2016-06-14

    Vehicle crashes can lead to crushing of the battery, damaging lithium ion battery cells and causing local shorts, heat generation, and thermal runaway. Simulating all the physics and geometries at the same time is challenging and takes a lot of effort; thus, simplifications are needed. We developed a material model for simultaneously modeling the mechanical-electrochemical-thermal behavior, which predicted the electrical short, voltage drop, and thermal runaway behaviors followed by a mechanical abuse-induced short. The effect of short resistance on the battery cell performance was studied.

  3. The minimum work requirement for distillation processes

    Energy Technology Data Exchange (ETDEWEB)

    Yunus, Cerci; Yunus, A. Cengel; Byard, Wood [Nevada Univ., Las Vegas, NV (United States). Dept. of Mechanical Engineering

    2000-07-01

    A typical ideal distillation process is proposed and analyzed using the first and second-laws of thermodynamics with particular attention to the minimum work requirement for individual processes. The distillation process consists of an evaporator, a condenser, a heat exchanger, and a number of heaters and coolers. Several Carnot engines are also employed to perform heat interactions of the distillation process with the surroundings and determine the minimum work requirement for processes. The Carnot engines give the maximum possible work output or the minimum work input associated with the processes, and therefore the net result of these inputs and outputs leads to the minimum work requirement for the entire distillation process. It is shown that the minimum work relation for the distillation process is the same as the minimum work input relation found by Cerci et al [1] for an incomplete separation of incoming saline water, and depends only on the properties of the incoming saline water and the outgoing pure water and brine. Also, certain aspects of the minimum work relation found are discussed briefly. (authors)

  4. Comparison of the volatile composition of Stachys pubescence oils obtained by hydro distillation and steam distillation.

    Science.gov (United States)

    Biglar, Mahmoud; Ardekani, Mohammad Reza Shams; Khanavi, Mahnaz; Shafiee, Abbas; Rustaiyan, Abdolhossein; Salimpour, Fahimeh; Farjadmand, Fatemeh

    2014-07-01

    The oils obtained by hydrodistillation and steam distillation of the aerial part of Stachys pubescence Ten. was analyzed by GC and GC/MS. Water distilled essential oil of the aerial part of S. pubescence, was rich in fatty acids like hexadecanoic acid and linoleic acid and also benzaldehyde and spathulenol whereas the steam distilled oil of the plant contained hexadecanoic acid, spathulenol and eugenol. Both of oils were rich in fatty acids (36.6 and 27.9%, respectively). Moreover, the content of oxygenated mono and sesquiterpenss were defined higher in steam distilled oil than hydrodistiledd oil (24.5, 17.2 and 6.1, 15.5%, respectively). In conclusion it seems that oxygenated terpenoids were trended to steam distillation method more than hydrodistillation, respectively.

  5. Hybrid pressure retarded osmosis-membrane distillation system for power generation from low-grade heat: thermodynamic analysis and energy efficiency.

    Science.gov (United States)

    Lin, Shihong; Yip, Ngai Yin; Cath, Tzahi Y; Osuji, Chinedum O; Elimelech, Menachem

    2014-05-06

    We present a novel hybrid membrane system that operates as a heat engine capable of utilizing low-grade thermal energy, which is not readily recoverable with existing technologies. The closed-loop system combines membrane distillation (MD), which generates concentrated and pure water streams by thermal separation, and pressure retarded osmosis (PRO), which converts the energy of mixing to electricity by a hydro-turbine. The PRO-MD system was modeled by coupling the mass and energy flows between the thermal separation (MD) and power generation (PRO) stages for heat source temperatures ranging from 40 to 80 °C and working concentrations of 1.0, 2.0, and 4.0 mol/kg NaCl. The factors controlling the energy efficiency of the heat engine were evaluated for both limited and unlimited mass and heat transfer kinetics in the thermal separation stage. In both cases, the relative flow rate between the MD permeate (distillate) and feed streams is identified as an important operation parameter. There is an optimal relative flow rate that maximizes the overall energy efficiency of the PRO-MD system for given working temperatures and concentration. In the case of unlimited mass and heat transfer kinetics, the energy efficiency of the system can be analytically determined based on thermodynamics. Our assessment indicates that the hybrid PRO-MD system can theoretically achieve an energy efficiency of 9.8% (81.6% of the Carnot efficiency) with hot and cold working temperatures of 60 and 20 °C, respectively, and a working solution of 1.0 M NaCl. When mass and heat transfer kinetics are limited, conditions that more closely represent actual operations, the practical energy efficiency will be lower than the theoretically achievable efficiency. In such practical operations, utilizing a higher working concentration will yield greater energy efficiency. Overall, our study demonstrates the theoretical viability of the PRO-MD system and identifies the key factors for performance

  6. Brain Emotional Learning Based Intelligent Decoupler for Nonlinear Multi-Input Multi-Output Distillation Columns

    Directory of Open Access Journals (Sweden)

    M. H. El-Saify

    2017-01-01

    Full Text Available The distillation process is vital in many fields of chemical industries, such as the two-coupled distillation columns that are usually highly nonlinear Multi-Input Multi-Output (MIMO coupled processes. The control of MIMO process is usually implemented via a decentralized approach using a set of Single-Input Single-Output (SISO loop controllers. Decoupling the MIMO process into group of single loops requires proper input-output pairing and development of decoupling compensator unit. This paper proposes a novel intelligent decoupling approach for MIMO processes based on new MIMO brain emotional learning architecture. A MIMO architecture of Brain Emotional Learning Based Intelligent Controller (BELBIC is developed and applied as a decoupler for 4 input/4 output highly nonlinear coupled distillation columns process. Moreover, the performance of the proposed Brain Emotional Learning Based Intelligent Decoupler (BELBID is enhanced using Particle Swarm Optimization (PSO technique. The performance is compared with the PSO optimized steady state decoupling compensation matrix. Mathematical models of the distillation columns and the decouplers are built and tested in simulation environment by applying the same inputs. The results prove remarkable success of the BELBID in minimizing the loops interactions without degrading the output that every input has been paired with.

  7. Contribution to the optimization of the coupling of nuclear reactors to desalination processes

    International Nuclear Information System (INIS)

    Dardour, S.

    2007-04-01

    This work deals with modelling, simulation and optimization of the coupling between nuclear reactors (PWR, modular high temperature reactors) and desalination processes (multiple effect distillation, reverse osmosis). The reactors considered in this study are PWR (Pressurized Water Reactor) and GTMHR (Gas Turbine Modular Helium Reactor). The desalination processes retained are MED (Multi Effect Distillation) and SWRO (Sea Water Reverse Osmosis). A software tool: EXCELEES of thermodynamic modelling of coupled systems, based on the Engineering Algebraic Equation Solver has been developed. Models of energy conversion systems and of membrane desalination processes and distillation have been developed. Based on the first and second principles of thermodynamics, these models have allowed to determine the optimal running point of the coupled systems. The thermodynamic analysis has been completed by a first economic evaluation. Based on the use of the DEEP software of the IAEA, this evaluation has confirmed the interest to use these types of reactors for desalination. A modelling tool of thermal processes of desalination in dynamic condition has been developed too. This tool has been applied to the study of the dynamics of an existing plant and has given satisfying results. A first safety checking has been at last carried out. The transients able to jeopardize the integrated system have been identified. Several measures aiming at consolidate the safety have been proposed. (O.M.)

  8. Neutronics and thermal-hydraulics coupling: some contributions toward an improved methodology to simulate the initiating phase of a severe accident in a sodium fast reactor

    International Nuclear Information System (INIS)

    Guyot, Maxime

    2014-01-01

    This project is dedicated to the analysis and the quantification of bias corresponding to the computational methodology for simulating the initiating phase of severe accidents on Sodium Fast Reactors. A deterministic approach is carried out to assess the consequences of a severe accident by adopting best estimate design evaluations. An objective of this deterministic approach is to provide guidance to mitigate severe accident developments and re-criticalities through the implementation of adequate design measures. These studies are generally based on modern simulation techniques to test and verify a given design. The new approach developed in this project aims to improve the safety assessment of Sodium Fast Reactors by decreasing the bias related to the deterministic analysis of severe accident scenarios. During the initiating phase, the subassembly wrapper tubes keep their mechanical integrity. Material disruption and dispersal is primarily one-dimensional. For this reason, evaluation methodology for the initiating phase relies on a multiple-channel approach. Typically a channel represents an average pin in a subassembly or a group of similar subassemblies. In the multiple-channel approach, the core thermal-hydraulics model is composed of 1 or 2 D channels. The thermal-hydraulics model is coupled to a neutronics module to provide an estimate of the reactor power level. In this project, a new computational model has been developed to extend the initiating phase modeling. This new model is based on a multi-physics coupling. This model has been applied to obtain information unavailable up to now in regards to neutronics and thermal-hydraulics models and their coupling. (author) [fr

  9. Coupling of aerosol behaviour and thermal-hydraulics. Reinforced concerted action on reactor safety source term project

    International Nuclear Information System (INIS)

    Bieder, U.; Fynbo, P.; Jokiniemi, J.; Paller, A.; Schatz, A.

    1993-12-01

    The status of the experimental work (LACE, KAEUER, FALCON test facilities, DEMONA and VANAM experiments) and the new generation of computer codes (eg. CONTAIN, FIPLOC-M, ITHACA, GOTHIC-M) for a coupled calculation of thermohydraulic and aerosol processes is reviewed and the lack of the present state of knowledge is summarized. The role of the coupled calculations with respect to advanced reactor design and to operating LWRs is also considered. (HP)

  10. Projecting range limits with coupled thermal tolerance - climate change models: an example based on gray snapper (Lutjanus griseus along the U.S. east coast.

    Directory of Open Access Journals (Sweden)

    Jonathan A Hare

    Full Text Available We couple a species range limit hypothesis with the output of an ensemble of general circulation models to project the poleward range limit of gray snapper. Using laboratory-derived thermal limits and statistical downscaling from IPCC AR4 general circulation models, we project that gray snapper will shift northwards; the magnitude of this shift is dependent on the magnitude of climate change. We also evaluate the uncertainty in our projection and find that statistical uncertainty associated with the experimentally-derived thermal limits is the largest contributor (∼ 65% to overall quantified uncertainty. This finding argues for more experimental work aimed at understanding and parameterizing the effects of climate change and variability on marine species.

  11. Projecting range limits with coupled thermal tolerance - climate change models: an example based on gray snapper (Lutjanus griseus) along the U.S. east coast.

    Science.gov (United States)

    Hare, Jonathan A; Wuenschel, Mark J; Kimball, Matthew E

    2012-01-01

    We couple a species range limit hypothesis with the output of an ensemble of general circulation models to project the poleward range limit of gray snapper. Using laboratory-derived thermal limits and statistical downscaling from IPCC AR4 general circulation models, we project that gray snapper will shift northwards; the magnitude of this shift is dependent on the magnitude of climate change. We also evaluate the uncertainty in our projection and find that statistical uncertainty associated with the experimentally-derived thermal limits is the largest contributor (∼ 65%) to overall quantified uncertainty. This finding argues for more experimental work aimed at understanding and parameterizing the effects of climate change and variability on marine species.

  12. Solvent distillations studies for a reprocessing plant

    International Nuclear Information System (INIS)

    Ginisty, C.; Guillaume, B.

    1989-01-01

    The substantial amounts of solvent used in large reprocessing plants are such that considerable care must be paid to solvent management to limit the production of organic wastes. The installation of intensive treatment by chemical regeneration serves to increase the service life of the solvent. General solvent management, combined with a distillation unit under reduced pressure also helps to recycle the two components of the solvent at a low activity level. Distillation also serves to remove the heavy degradation products that are generally responsible for poor hydraulic behavior and for the holdup of radioactive products such as plutonium, zirconium and ruthenium. From the safety standpoint, the flashpoint of the distilled diluent tends to rise. It can therefore be recycled without risk

  13. Entanglement distillation protocols and number theory

    International Nuclear Information System (INIS)

    Bombin, H.; Martin-Delgado, M.A.

    2005-01-01

    We show that the analysis of entanglement distillation protocols for qudits of arbitrary dimension D benefits from applying basic concepts from number theory, since the set Z D n associated with Bell diagonal states is a module rather than a vector space. We find that a partition of Z D n into divisor classes characterizes the invariant properties of mixed Bell diagonal states under local permutations. We construct a very general class of recursion protocols by means of unitary operations implementing these local permutations. We study these distillation protocols depending on whether we use twirling operations in the intermediate steps or not, and we study them both analytically and numerically with Monte Carlo methods. In the absence of twirling operations, we construct extensions of the quantum privacy algorithms valid for secure communications with qudits of any dimension D. When D is a prime number, we show that distillation protocols are optimal both qualitatively and quantitatively

  14. Superadditivity of distillable entanglement from quantum teleportation

    Science.gov (United States)

    Bandyopadhyay, Somshubhro; Roychowdhury, Vwani

    2005-12-01

    We show that the phenomenon of superadditivity of distillable entanglement observed in multipartite quantum systems results from the consideration of states created during the execution of the standard end-to-end quantum teleportation protocol [and a few additional local operations and classical communication (LOCC) steps] on a linear chain of singlets. Some of these intermediate states are tensor products of bound entangled (BE) states, and hence, by construction possess distillable entanglement, which can be unlocked by simply completing the rest of the LOCC operations required by the underlying teleportation protocol. We use this systematic approach to construct both new and known examples of superactivation of bound entanglement, and examples of activation of BE states using other BE states. A surprising outcome is the construction of noiseless quantum relay channels with no distillable entanglement between any two parties, except for that between the two end nodes.

  15. Superadditivity of distillable entanglement from quantum teleportation

    International Nuclear Information System (INIS)

    Bandyopadhyay, Somshubhro; Roychowdhury, Vwani

    2005-01-01

    We show that the phenomenon of superadditivity of distillable entanglement observed in multipartite quantum systems results from the consideration of states created during the execution of the standard end-to-end quantum teleportation protocol [and a few additional local operations and classical communication (LOCC) steps] on a linear chain of singlets. Some of these intermediate states are tensor products of bound entangled (BE) states, and hence, by construction possess distillable entanglement, which can be unlocked by simply completing the rest of the LOCC operations required by the underlying teleportation protocol. We use this systematic approach to construct both new and known examples of superactivation of bound entanglement, and examples of activation of BE states using other BE states. A surprising outcome is the construction of noiseless quantum relay channels with no distillable entanglement between any two parties, except for that between the two end nodes

  16. Influence of coil current modulation on polycrystalline diamond film deposition by irradiation of Ar/CH4/H2 inductively coupled thermal plasmas

    Science.gov (United States)

    Betsuin, Toshiki; Tanaka, Yasunori; Arai, T.; Uesugi, Y.; Ishijima, T.

    2018-03-01

    This paper describes the application of an Ar/CH4/H2 inductively coupled thermal plasma with and without coil current modulation to synthesise diamond films. Induction thermal plasma with coil current modulation is referred to as modulated induction thermal plasma (M-ITP), while that without modulation is referred to as non-modulated ITP (NM-ITP). First, spectroscopic observations of NM-ITP and M-ITP with different modulation waveforms were made to estimate the composition in flux from the thermal plasma by measuring the time evolution in the spectral intensity from the species. Secondly, we studied polycrystalline diamond film deposition tests on a Si substrate, and we studied monocrystalline diamond film growth tests using the irradiation of NM-ITP and M-ITP. From these tests, diamond nucleation effects by M-ITP were found. Finally, following the irradiation results, we attempted to use a time-series irradiation of M-ITP and NM-ITP for polycrystalline diamond film deposition on a Si substrate. The results indicated that numerous larger diamond particles were deposited with a high population density on the Si substrate by time-series irradiation.

  17. Combining structural-thermal coupled field FE analysis and the Taguchi method to evaluate the relative contributions of multi-factors in a premolar adhesive MOD restoration.

    Science.gov (United States)

    Lin, Chun-Li; Chang, Yen-Hsiang; Lin, Yi-Feng

    2008-08-01

    The aim of this study was to determine the relative contribution of changes in restorative material, cavity dimensions, adhesive layer adaptation, and load conditions on the biomechanical response of an adhesive Class II MOD restoration during oral temperature changes. A validated finite-element (FE) model was used to perform the structural-thermal coupled field analyses and the Taguchi method was employed to identify the significance of each design factor in controlling the stress. The results indicated that thermal expansion in restorative material amplified the thermal effect and dominated the tooth stress value (69%) at high temperatures. The percentage contributions of the load conditions, cavity depth, and cement modulus increased the effect on tooth stress values 46%, 32%, and 14%, respectively, when the tooth temperature was returned to 37 degrees C. Load conditions were also the main factor influencing the resin cement stress values, irrespective of temperature changes. Increased stress values occurred with composite resin, lateral force, a deeper cavity, and a higher luting cement modulus. The combined use of FE analysis and the Taguchi method efficiently identified that a deeper cavity might increase the risk of a restored tooth fracture, as well as a ceramic inlay with a lower thermal expansion, attaining a proper occlusal adjustment to reduce the lateral occlusal force and low modulus luting material application to obtain a better force-transmission mechanism are recommended.

  18. Source book for planning nuclear dual-purpose electric/distillation desalination plants

    International Nuclear Information System (INIS)

    Reed, S.A.

    1981-02-01

    A source book on nuclear dual-purpose electric/distillation desalination plants was prepared to assist government and other planners in preparing broad evaluations of proposed applications of dual-purpose plants. The document is divided into five major sections. Section 1 presents general discussions relating to the benefits of dual-purpose plants, and spectrum for water-to-power ratios. Section 2 presents information on commercial nuclear plants manufactured by US manufacturers. Section 3 gives information on distillation desalting processes and equipment. Section 4 presents a discussion on feedwater pretreatment and scale control. Section 5 deals with methods for coupling the distillation and electrical generating plants to operate in the dual mode

  19. Source book for planning nuclear dual-purpose electric/distillation desalination plants

    Energy Technology Data Exchange (ETDEWEB)

    Reed, S.A.

    1981-02-01

    A source book on nuclear dual-purpose electric/distillation desalination plants was prepared to assist government and other planners in preparing broad evaluations of proposed applications of dual-purpose plants. The document is divided into five major sections. Section 1 presents general discussions relating to the benefits of dual-purpose plants, and spectrum for water-to-power ratios. Section 2 presents information on commercial nuclear plants manufactured by US manufacturers. Section 3 gives information on distillation desalting processes and equipment. Section 4 presents a discussion on feedwater pretreatment and scale control. Section 5 deals with methods for coupling the distillation and electrical generating plants to operate in the dual mode.

  20. Selective distillation phenomenon in two-species Bose-Einstein condensates in open boundary optical lattices

    Science.gov (United States)

    Bai, Xiao-Dong; Zhang, Mei; Xiong, Jun; Yang, Guo-Jian; Deng, Fu-Guo

    2015-11-01

    We investigate the formation of discrete breathers (DBs) and the dynamics of the mixture of two-species Bose-Einstein condensates (BECs) in open boundary optical lattices using the discrete nonlinear Schrödinger equations. The results show that the coupling of intra- and interspecies interaction can lead to the existence of pure single-species DBs and symbiotic DBs (i.e., two-species DBs). Furthermore, we find that there is a selective distillation phenomenon in the dynamics of the mixture of two-species BECs. One can selectively distil one species from the mixture of two-species BECs and can even control dominant species fraction by adjusting the intra- and interspecies interaction in optical lattices. Our selective distillation mechanism may find potential application in quantum information storage and quantum information processing based on multi-species atoms.

  1. Refreshment topics II: Design of distillation columns

    Directory of Open Access Journals (Sweden)

    Milojević Svetomir

    2006-01-01

    Full Text Available For distillation column design it is necessary to define all the variable parameters such as component concentrations in different streams temperatures, pressures, mass and energy flow, which are used to represent the separation process of some specific system. They are related to each other according to specific laws, and if the number of such parameters exceeds the number of their relationships, in order to solve a problem some of them must be specified in advance or some constraints assumed for the mass balance, the balance of energy, phase equilibria or chemical equilibria. Knowledge of specific elements which are the constituents of a distillation unit must be known to define the number of design parameters as well as some additional apparati also necessary to realize the distilation. Each separate apparatus might be designed and constructed only if all the necessary and variable parameters for such a unit are defined. This is the right route to solve a distilation unit in many different cases. The construction of some distillation unit requires very good knowledge of mass, heat and momentum transfer phenomena. Moreover, the designer needs to know which kind of apparatus will be used in the distillation unit to realize a specific production process. The most complicated apparatus in a rectification unit is the distillation column. Depending on the complexity of the separation process one, two or more columns are often used. Additional equipment are heat exchangers (reboilers, condensers, cooling systems, heaters, separators, tanks for reflux distribution, tanks and pumps for feed transportation, etc. Such equipment is connected by pipes and valves, and for the normal operation of a distillation unit other instruments for measuring the flow rate, temperature and pressure are also required. Problems which might arise during the determination and selection of such apparati and their number requires knowledge of the specific systems which must

  2. Functionalization of a Hydrophilic Commercial Membrane Using Inorganic-Organic Polymers Coatings for Membrane Distillation

    Directory of Open Access Journals (Sweden)

    Lies Eykens

    2017-06-01

    Full Text Available Membrane distillation is a thermal separation technique using a microporous hydrophobic membrane. One of the concerns with respect to the industrialization of the technique is the development of novel membranes. In this paper, a commercially available hydrophilic polyethersulfone membrane with a suitable structure for membrane distillation was modified using available hydrophobic coatings using ORMOCER® technology to obtain a hydrophobic membrane that can be applied in membrane distillation. The surface modification was performed using a selection of different components, concentrations, and application methods. The resulting membranes can have two hydrophobic surfaces or a hydrophobic and hydrophilic surface depending on the application method. An extensive characterization procedure confirmed the suitability of the coating technique and the obtained membranes for membrane distillation. The surface contact angle of water could be increased from 27° up to 110°, and fluxes comparable to membranes commonly used for membrane distillation were achieved under similar process conditions. A 100 h test demonstrated the stability of the coating and the importance of using sufficiently stable base membranes.

  3. Production of diesel-like fuel from waste engine oil by pyrolitic distillation

    Energy Technology Data Exchange (ETDEWEB)

    Arpa, Orhan [Dicle University, Mechanical Engineering Department, Diyarbakir (Turkey); Yumrutas, Recep [University of Gaziantep, Mechanical Engineering Department, Gaziantep (Turkey); Demirbas, Ayhan [Sila Science, Trabzon (Turkey)

    2010-01-15

    The aim of this study is to obtain diesel-like fuel from waste lubrication engine oils by pyrolitic distillation method, which can be used in diesel engines. With this aim in mind, waste engine oil is collected in a tank, and it is purified from contaminants such as dust, heavy carbon soot, metal particles, gum-type materials and other impurities by filtering in the process prepared earlier. To investigate effects of additives known as sodium carbonate (NaCO{sub 3}), zeolite and lime (CaO) on density, viscosity, flash point, sulfur content, heating value and distillation temperature, the purified oil samples are blended separately with additives having mass basis of 2%, 4%, 6%, 8% and 10%. The mixed samples are exposed to pyrolitic distillation process to produce fuels to be used in engines. Thermal and physical properties of the produced fuels such as density, flash point, viscosity, sulfur content, heating value and distillation temperatures are examined. From these results, the CaO with a ratio of 2% has the highest effect on decreasing of sulfur content of the waste engine oil and on acquiring the most suitable distillation temperatures close to values of a diesel fuel. Diesel-like fuel (DLF) is obtained as 60% of the waste lubrication engine oil. (author)

  4. Biocuration: Distilling data into knowledge.

    Science.gov (United States)

    2018-04-01

    Data, including information generated from them by processing and analysis, are an asset with measurable value. The assets that biological research funding produces are the data generated, the information derived from these data, and, ultimately, the discoveries and knowledge these lead to. From the time when Henry Oldenburg published the first scientific journal in 1665 (Proceedings of the Royal Society) to the founding of the United States National Library of Medicine in 1879 to the present, there has been a sustained drive to improve how researchers can record and discover what is known. Researchers' experimental work builds upon years and (collectively) billions of dollars' worth of earlier work. Today, researchers are generating data at ever-faster rates because of advances in instrumentation and technology, coupled with decreases in production costs. Unfortunately, the ability of researchers to manage and disseminate their results has not kept pace, so their work cannot achieve its maximal impact. Strides have recently been made, but more awareness is needed of the essential role that biological data resources, including biocuration, play in maintaining and linking this ever-growing flood of data and information. The aim of this paper is to describe the nature of data as an asset, the role biocurators play in increasing its value, and consistent, practical means to measure effectiveness that can guide planning and justify costs in biological research information resources' development and management.

  5. Polypropylene/Short Glass Fibers Composites: Effects of Coupling Agents on Mechanical Properties, Thermal Behaviors, and Morphology

    Directory of Open Access Journals (Sweden)

    Jia-Horng Lin

    2015-12-01

    Full Text Available This study uses the melt compounding method to produce polypropylene (PP/short glass fibers (SGF composites. PP serves as matrix while SGF serves as reinforcement. Two coupling agents, maleic anhydride grafted polypropylene, (PP-g-MA and maleic anhydride grafted styrene-ethylene-butylene-styrene block copolymer (SEBS-g-MA are incorporated in the PP/SGF composites during the compounding process, in order to improve the interfacial adhesion and create diverse desired properties of the composites. According to the mechanical property evaluations, increasing PP-g-MA as a coupling agent provides the composites with higher tensile, flexural, and impact properties. In contrast, increasing SEBS-g-MA as a coupling agent provides the composites with decreasing tensile and flexural strengths, but also increasing impact strength. The DSC results indicate that using either PP-g-MA or SEBS-g-MA as the coupling agent increases the crystallization temperature. However, the melting temperature of PP barely changes. The spherulitic morphology results show that PP has a smaller spherulite size when it is processed with PP-g-MA or SEBS-g-MA as the coupling agent. The SEM results indicate that SGF is evenly distributed in PP matrices, but there are distinct voids between these two materials, indicating a poor interfacial adhesion. After PP-g-MA or SEBS-g-MA is incorporated, SGF can be encapsulated by PP, and the voids between them are fewer and indistinctive. This indicates that the coupling agents can effectively improve the interfacial compatibility between PP and SGF, and as a result improves the diverse properties of PP/SGF composites.

  6. Performance simulation of the JPL solar-powered distiller. Part 1: Quasi-steady-state conditions. [for cooling microwave equipment

    Science.gov (United States)

    Yung, C. S.; Lansing, F. L.

    1983-01-01

    A 37.85 cu m (10,000 gallons) per year (nominal) passive solar powered water distillation system was installed and is operational in the Venus Deep Space Station. The system replaced an old, electrically powered water distiller. The distilled water produced with its high electrical resistivity is used to cool the sensitive microwave equipment. A detailed thermal model was developed to simulate the performance of the distiller and study its sensitivity under varying environment and load conditions. The quasi-steady state portion of the model is presented together with the formulas for heat and mass transfer coefficients used. Initial results indicated that a daily water evaporation efficiency of 30% can be achieved. A comparison made between a full day performance simulation and the actual field measurements gave good agreement between theory and experiment, which verified the model.

  7. Static multiplicities in heterogeneous azeotropic distillation sequences

    DEFF Research Database (Denmark)

    Esbjerg, Klavs; Andersen, Torben Ravn; Jørgensen, Sten Bay

    1998-01-01

    different static behavior. The method of Petlyuk and Avet'yan (1971), Bekiaris et al. (1993), which assumes infinite reflux and infinite number of stages, is extended to and applied on heterogeneous azeotropic distillation sequences. The predictions are substantiated through simulations. The static sequence...

  8. Non-equilibrium modelling of distillation

    NARCIS (Netherlands)

    Wesselingh, JA; Darton, R

    1997-01-01

    There are nasty conceptual problems in the classical way of describing distillation columns via equilibrium stages, and efficiencies or HETP's. We can nowadays avoid these problems by simulating the behaviour of a complete column in one go using a non-equilibrium model. Such a model has phase

  9. Robust Geometric Control of a Distillation Column

    DEFF Research Database (Denmark)

    Kymmel, Mogens; Andersen, Henrik Weisberg

    1987-01-01

    A frequency domain method, which makes it possible to adjust multivariable controllers with respect to both nominal performance and robustness, is presented. The basic idea in the approach is that the designer assigns objectives such as steady-state tracking, maximum resonance peaks, bandwidth, m...... is used to examine and improve geometric control of a binary distillation column....

  10. Designing reactive distillation processes with improved efficiency

    NARCIS (Netherlands)

    Almeida-Rivera, C.P.

    2005-01-01

    In this dissertation a life-span inspired perspective is taken on the conceptual design of grassroots reactive distillation processes. Attention was paid to the economic performance of the process and to potential losses of valuable resources over the process life span. The research was cast in a

  11. Innovative and Advanced Coupled Neutron Transport and Thermal Hydraulic Method (Tool) for the Design, Analysis and Optimization of VHTR/NGNP Prismatic Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Rahnema, Farzad; Garimeela, Srinivas; Ougouag, Abderrafi; Zhang, Dingkang

    2013-11-29

    This project will develop a 3D, advanced coarse mesh transport method (COMET-Hex) for steady- state and transient analyses in advanced very high-temperature reactors (VHTRs). The project will lead to a coupled neutronics and thermal hydraulic (T/H) core simulation tool with fuel depletion capability. The computational tool will be developed in hexagonal geometry, based solely on transport theory without (spatial) homogenization in complicated 3D geometries. In addition to the hexagonal geometry extension, collaborators will concurrently develop three additional capabilities to increase the code’s versatility as an advanced and robust core simulator for VHTRs. First, the project team will develop and implement a depletion method within the core simulator. Second, the team will develop an elementary (proof-of-concept) 1D time-dependent transport method for efficient transient analyses. The third capability will be a thermal hydraulic method coupled to the neutronics transport module for VHTRs. Current advancements in reactor core design are pushing VHTRs toward greater core and fuel heterogeneity to pursue higher burn-ups, efficiently transmute used fuel, maximize energy production, and improve plant economics and safety. As a result, an accurate and efficient neutron transport, with capabilities to treat heterogeneous burnable poison effects, is highly desirable for predicting VHTR neutronics performance. This research project’s primary objective is to advance the state of the art for reactor analysis.

  12. A two-dimensional nodal model with turbulent effects for the synthesis of Si nano-particles by inductively coupled thermal plasmas

    International Nuclear Information System (INIS)

    Colombo, V; Ghedini, E; Gherardi, M; Sanibondi, P; Shigeta, M

    2012-01-01

    Nano-particle synthesis by means of inductively coupled plasma torches is a material process of large technological interest. Numerous parameters are involved in the optimization of this process; hence the development of numerical models for the prediction of thermal and magneto-fluid dynamics fields, precursor powder trajectories and thermal history, as well as nano-particle formation and growth, is necessary for the up-scaling of these devices from laboratory batch production to an industrial continuous process. In this work, a two-dimensional (2D) discrete-type model (nodal model) for the analysis of nano-powder nucleation and growth is presented, taking into account convection, diffusion and turbulent effects on particle formation. Discrete-type models feature high precision and reveal a great deal of information useful for clarifying the nano-particle formation process. Using Si as the precursor material, 2D simulations of a nano-particle synthesis RF plasma apparatus with a reaction chamber are carried out. Good agreement is found when comparing results obtained with this model with those coming from a well-established nucleation-coupled moment method. Moreover, the extended amount of obtainable information that characterizes the nodal model is underlined. (paper)

  13. Spin transfer torque switching in exchange-coupled amorphous GdFeCo/TbFe bilayers for thermally assisted MRAM application

    Science.gov (United States)

    Dai, Bing; Guo, Yong; Zhu, Jiaqi; Kato, Takeshi; Iwata, Satoshi; Tsunashima, Shigeru; Yang, Lei; Han, Jiecai

    2017-04-01

    Exchange-coupled amorphous GdFeCo/TbFe memory layers in giant magneto-resistance (GMR) devices for spin transfer torque (STT) switching have been studied, and temperature dependence of the critical current density of the GMR devices was measured to discuss the effect of exchange-coupled bilayers as a memory layer of the thermally assisted magnetic random access memory (MRAM). The GMR devices having amorphous GdFeCo and TbFe memory bilayers with various thicknesses were prepared by magnetron sputtering and subsequent micro-fabrication processes. A pulsed current was applied to the GMR devices in order to investigate the spin transfer torque (STT) switching. The maximum magneto-resistance (MR) ratio was around 0.15%, and the coercivity of the memory bilayer increased with the TbFe thickness and decreased with elevating temperature. The critical current densities J c to switch the memory bilayer with structure of Gd21.4 (Fe90Co10)78.6(9 nm)/Tb16Fe84 (1 nm) as low as 2.2  ×  107 A cm-2 was obtained. The J c reduced with increasing the temperature and was found to scale with the effective anisotropy K eff of GdFeCo/TbFe bilayer, which is believed to be suitable for the application of thermally assisted STT-MRAM.

  14. Irreversibility analysis in the process of solar distillation

    Science.gov (United States)

    Chávez, S.; Terres, H.; Lizardi, A.; López, R.; Lara, A.

    2017-01-01

    In this work an irreversibility analysis for the thermal process of solar distillation of three different substances is presented, for which it employs a solar still of a slope where three experimental tests with 5.5 L of brine, river water and MgCl2 were performed. Temperature data principally in the glass cover, absorber plate, fluid, environment and the incident solar radiation on the device were obtained. With measurements of temperature, solar radiation and exergetic balance, irreversibilities are found on the device. The results show that the highest values of irreversibilities are concentrated in the absorber plate with an average of 321 W, 342 W and 276 W, followed by the cover glass with an average of 75.8 W, 80.4 W and 86.7 W and finally the fluid with 15.3 W, 15.9 W and 16 W, for 5.5 L of brine, river water and MgCl2.

  15. Effectiveness of Water Desalination by Membrane Distillation Process

    Directory of Open Access Journals (Sweden)

    Marek Gryta

    2012-07-01

    Full Text Available The membrane distillation process constitutes one of the possibilities for a new method for water desalination. Four kinds of polypropylene membranes with different diameters of capillaries and pores, as well as wall thicknesses were used in studied. The morphology of the membrane used and the operating parameters significantly influenced process efficiency. It was found that the membranes with lower wall thickness and a larger pore size resulted in the higher yields. Increasing both feed flow rate and temperature increases the permeate flux and simultaneously the process efficiency. However, the use of higher flow rates also enhanced heat losses by conduction, which decreases the thermal efficiency. This efficiency also decreases when the salt concentration in the feed was enhanced. The influence of fouling on the process efficiency was considered.

  16. Effectiveness of Water Desalination by Membrane Distillation Process

    Science.gov (United States)

    Gryta, Marek

    2012-01-01

    The membrane distillation process constitutes one of the possibilities for a new method for water desalination. Four kinds of polypropylene membranes with different diameters of capillaries and pores, as well as wall thicknesses were used in studied. The morphology of the membrane used and the operating parameters significantly influenced process efficiency. It was found that the membranes with lower wall thickness and a larger pore size resulted in the higher yields. Increasing both feed flow rate and temperature increases the permeate flux and simultaneously the process efficiency. However, the use of higher flow rates also enhanced heat losses by conduction, which decreases the thermal efficiency. This efficiency also decreases when the salt concentration in the feed was enhanced. The influence of fouling on the process efficiency was considered. PMID:24958289

  17. Use of thermal analysis coupled with differential scanning calorimetry, quadrupole mass spectrometry and infrared spectroscopy (TG-DSC-QMS-FTIR to monitor chemical properties and thermal stability of fulvic and humic acids.

    Directory of Open Access Journals (Sweden)

    Patrycja Boguta

    Full Text Available Thermogravimetry-coupled with differential scanning calorimetry, quadrupole mass spectrometry, and Fourier-transform infrared spectroscopy (TG-DSC-QMS-FTIR-was applied to monitor the thermal stability (in an N2 pyrolytic atmosphere and chemical properties of natural polymers, fulvic (FA and humic acids (HA, isolated from chemically different soils. Three temperature ranges, R1, 40-220°C; R2, 220-430°C; and R3, 430-650°C, were distinguished from the DSC data, related to the main thermal processes of different structures (including transformations without weight loss. Weight loss (ΔM estimated from TG curves at the above temperature intervals revealed distinct differences within the samples in the content of physically adsorbed water (at R1, volatile and labile functional groups (at R2 as well as recalcitrant and refractory structures (at R3. QMS and FTIR modules enabled the chemical identification (by masses and by functional groups, respectively of gaseous species evolved during thermal decomposition at R1, R2 and R3. Variability in shape, area and temperature of TG, DSC, QMS and FTIR peaks revealed differences in thermal stability and chemical structure of the samples between the FAs and HAs fractions of different origin. The statistical analysis showed that the parameters calculated from QMS (areas of m/z = 16, 17, 18, 44, DSC (MaxDSC and TG (ΔM at R1, R2 and R3 correlated with selected chemical properties of the samples, such as N, O and COOH content as well as E2/E6 and E2/E4 indexes. This indicated a high potential for the coupled method to monitor the chemical changes of humic substances. A new humification parameter, HTD, based on simple calculations of weight loss at specific temperature intervals proved to be a good alternative to indexes obtained from other methods. The above findings showed that the TG-DSC-QMS-FTIR coupled technique can represent a useful tool for the comprehensive assessment of FAs and HAs properties related to

  18. Use of thermal analysis coupled with differential scanning calorimetry, quadrupole mass spectrometry and infrared spectroscopy (TG-DSC-QMS-FTIR) to monitor chemical properties and thermal stability of fulvic and humic acids.

    Science.gov (United States)

    Boguta, Patrycja; Sokołowska, Zofia; Skic, Kamil

    2017-01-01

    Thermogravimetry-coupled with differential scanning calorimetry, quadrupole mass spectrometry, and Fourier-transform infrared spectroscopy (TG-DSC-QMS-FTIR)-was applied to monitor the thermal stability (in an N2 pyrolytic atmosphere) and chemical properties of natural polymers, fulvic (FA) and humic acids (HA), isolated from chemically different soils. Three temperature ranges, R1, 40-220°C; R2, 220-430°C; and R3, 430-650°C, were distinguished from the DSC data, related to the main thermal processes of different structures (including transformations without weight loss). Weight loss (ΔM) estimated from TG curves at the above temperature intervals revealed distinct differences within the samples in the content of physically adsorbed water (at R1), volatile and labile functional groups (at R2) as well as recalcitrant and refractory structures (at R3). QMS and FTIR modules enabled the chemical identification (by masses and by functional groups, respectively) of gaseous species evolved during thermal decomposition at R1, R2 and R3. Variability in shape, area and temperature of TG, DSC, QMS and FTIR peaks revealed differences in thermal stability and chemical structure of the samples between the FAs and HAs fractions of different origin. The statistical analysis showed that the parameters calculated from QMS (areas of m/z = 16, 17, 18, 44), DSC (MaxDSC) and TG (ΔM) at R1, R2 and R3 correlated with selected chemical properties of the samples, such as N, O and COOH content as well as E2/E6 and E2/E4 indexes. This indicated a high potential for the coupled method to monitor the chemical changes of humic substances. A new humification parameter, HTD, based on simple calculations of weight loss at specific temperature intervals proved to be a good alternative to indexes obtained from other methods. The above findings showed that the TG-DSC-QMS-FTIR coupled technique can represent a useful tool for the comprehensive assessment of FAs and HAs properties related to their

  19. Modeling thermal dynamics of active layer soils and near-surface permafrost using a fully coupled water and heat transport model

    Science.gov (United States)

    Jiang, Yueyang; Zhuang, Qianlai; O'Donnell, Jonathan A.

    2012-01-01

    Thawing and freezing processes are key components in permafrost dynamics, and these processes play an important role in regulating the hydrological and carbon cycles in the northern high latitudes. In the present study, we apply a well-developed soil thermal model that fully couples heat and water transport, to simulate the thawing and freezing processes at daily time steps across multiple sites that vary with vegetation cover, disturbance history, and climate. The model performance was evaluated by comparing modeled and measured soil temperatures at different depths. We use the model to explore the influence of climate, fire disturbance, and topography (north- and south-facing slopes) on soil thermal dynamics. Modeled soil temperatures agree well with measured values for both boreal forest and tundra ecosystems at the site level. Combustion of organic-soil horizons during wildfire alters the surface energy balance and increases the downward heat flux through the soil profile, resulting in the warming and thawing of near-surface permafrost. A projection of 21st century permafrost dynamics indicates that as the climate warms, active layer thickness will likely increase to more than 3 meters in the boreal forest site and deeper than one meter in the tundra site. Results from this coupled heat-water modeling approach represent faster thaw rates than previously simulated in other studies. We conclude that the discussed soil thermal model is able to well simulate the permafrost dynamics and could be used as a tool to analyze the influence of climate change and wildfire disturbance on permafrost thawing.

  20. Coupling of Mechanical Behavior of Lithium Ion Cells to Electrochemical-Thermal Models for Battery Crush; NREL (National Renewable Energy Laboratory)

    Energy Technology Data Exchange (ETDEWEB)

    Pesaran, Ahmad; Zhang, Chao; Santhanagopalan, Shriram; Sahraei, Elham; Wierzbiki, Tom

    2015-06-15

    Propagation of failure in lithium-ion batteries during field events or under abuse is a strong function of the mechanical response of the different components in the battery. Whereas thermal and electrochemical models that capture the abuse response of batteries have been developed and matured over the years, the interaction between the mechanical behavior and the thermal response of these batteries is not very well understood. With support from the Department of Energy, NREL has made progress in coupling mechanical, thermal, and electrochemical lithium-ion models to predict the initiation and propagation of short circuits under external crush in a cell. The challenge with a cell crush simulation is to estimate the magnitude and location of the short. To address this, the model includes an explicit representation of each individual component such as the active material, current collector, separator, etc., and predicts their mechanical deformation under different crush scenarios. Initial results show reasonable agreement with experiments. In this presentation, the versatility of the approach for use with different design factors, cell formats and chemistries is explored using examples.

  1. Modeling the Structural-Thermal-Electrical Coupling in an Electrostatically Actuated MEMS Switch and Its Impact on the Switch Stability

    Directory of Open Access Journals (Sweden)

    Hassen M. Ouakad

    2013-01-01

    Full Text Available Modeling and analysis for the static behavior and collapse instabilities of a MEMS cantilever switch subjected to both electrical and thermal loadings are presented. The thermal loading forces can be as a result of a huge amount of switching contact of the microswitch. The model considers the microbeam as a continuous medium and the electric force as a nonlinear function of displacement and accounts for its fringing-field effect. The electric force is assumed to be distributed over specific lengths underneath the microbeam. A boundary-value solver is used to study the collapse instability, which brings the microbeam from its unstuck configuration to touch the substrate and gets stuck in the so-called pinned configuration. We have found negligible influence of the temperature on the static stability of the switch. We then investigate the effect of the thermal heating due to the current flow on the cantilever switch while it is in the on position (adhered position. We also found slight effect on the static stability of the switch.

  2. Mechanical properties, morphology and thermal degradation of a biocomposite of polypropylene and curaua fibers: coupling agent effect

    Directory of Open Access Journals (Sweden)

    Barbara Mano

    2013-01-01

    Full Text Available Biocomposites of polymers with vegetal fibers have a broad spectrum of applications due to their high specific properties in comparison to their counterparts made with fiberglass. Polypropylene, PP, composites with curaua fiber compatibilized with different concentrations of maleic anhydride grafted polypropylene, PP-g-MA, were characterized according to their mechanical properties, morphologies and thermal stabilities in oxidative and inert atmospheres. The composites were prepared by single screw extrusion and injection molded specimens were used for testing. The composite with 20 wt % of curaua fiber with and without compatibilizer presented improved mechanical properties compared to pure PP. The use of PP-g-MA as a compatibilizer significantly increased fiber/matrix adhesion, however, the mechanical properties were only slightly improved in comparison with composites without compatibilizer. We observed an improvement in thermal stability of the composites, compared to that expected from the weighted average of the individual components, both under inert and oxidative atmospheres. Furthermore, the thermal stability improved under inert atmosphere as a function of the concentration of compatibilizer. In this situation, indeed, there was a different shift of the weight loss processes owing to the presence of the compatibilizer.

  3. High-temperature stability of chemically vapor-deposited tungsten-silicon couples rapid thermal annealed in ammonia and argon

    International Nuclear Information System (INIS)

    Broadbent, E.K.; Morgan, A.E.; Flanner, J.M.; Coulman, B.; Sadana, D.K.; Burrow, B.J.; Ellwanger, R.C.

    1988-01-01

    A rapid thermal anneal (RTA) in an NH 3 ambient has been found to increase the thermal stability of W films chemically vapor deposited (CVD) on Si. W films deposited onto single-crystal Si by low-pressure CVD were rapid thermal annealed at temperatures between 500 and 1100 0 C in NH 3 and Ar ambients. The reactions were studied using Rutherford backscattering spectrometry, x-ray diffraction, Auger electron spectroscopy, transmission electron microscopy, and four-point resistivity probe. High-temperature (≥1000 0 C) RTA in Ar completely converted W into the low resistivity (31 μΩ cm) tetragonal WSi 2 phase. In contrast, after a prior 900 0 C RTA in NH 3 , N inclusion within the W film and at the W/Si interface almost completely suppressed the W-Si reaction. Detailed examination, however, revealed some patches of WSi 2 formed at the interface accompanied by long tunnels extending into the substrate, and some crystalline precipitates in the substrate close to the interface. The associated interfacial contact resistance was only slightly altered by the 900 0 C NH 3 anneal. The NH 3 -treated W film acted as a diffusion barrier in an Al/W/Si contact metallurgy up to at least 550 0 C, at which point some increase in contact resistance was measured

  4. High-temperature stability of chemically vapor-deposited tungsten-silicon couples rapid thermal annealed in ammonia and argon

    Energy Technology Data Exchange (ETDEWEB)

    Broadbent, E.K.; Morgan, A.E.; Flanner, J.M.; Coulman, B.; Sadana, D.K.; Burrow, B.J.; Ellwanger, R.C.

    1988-12-15

    A rapid thermal anneal (RTA) in an NH/sub 3/ ambient has been found to increase the thermal stability of W films chemically vapor deposited (CVD) on Si. W films deposited onto single-crystal Si by low-pressure CVD were rapid thermal annealed at temperatures between 500 and 1100 /sup 0/C in NH/sub 3/ and Ar ambients. The reactions were studied using Rutherford backscattering spectrometry, x-ray diffraction, Auger electron spectroscopy, transmission electron microscopy, and four-point resistivity probe. High-temperature (greater than or equal to1000 /sup 0/C) RTA in Ar completely converted W into the low resistivity (31 ..mu cap omega.. cm) tetragonal WSi/sub 2/ phase. In contrast, after a prior 900 /sup 0/C RTA in NH/sub 3/, N inclusion within the W film and at the W/Si interface almost completely suppressed the W-Si reaction. Detailed examination, however, revealed some patches of WSi/sub 2/ formed at the interface accompanied by long tunnels extending into the substrate, and some crystalline precipitates in the substrate close to the interface. The associated interfacial contact resistance was only slightly altered by the 900 /sup 0/C NH/sub 3/ anneal. The NH/sub 3/-treated W film acted as a diffusion barrier in an Al/W/Si contact metallurgy up to at least 550 /sup 0/C, at which point some increase in contact resistance was measured.

  5. Thermal shaft effects on load-carrying capacity of a fully coupled, variable-properties cryogenic journal bearing

    Science.gov (United States)

    Braun, M. J.; Wheeler, R. L., III; Hendricks, R. C.

    1986-01-01

    The purpose of this work was to perform a rather complete analysis for a cryogenic (oxygen) journal bearing. The Reynolds equation required coupling and simultaneous solution with the fluid energy equation. To correctly account for the changes in the fluid viscosity, the fluid energy equation was coupled with the shaft and bearing heat conduction energy equations. The effects of pressure and temperature on the density, viscosity, and load-carrying capacity were further discussed as analysis parameters, with respect to relative eccentricity and the angular velocity. The isothermal fluid case and the adiabatic fluid case represented the limiting boundaries. The discussion was further extrapolated to study the Sommerfeld number dependency on the fluid Nusselt number and its consequence on possible total loss of load-carrying capacity and/or seizure (catastrophic failure).

  6. Comparison of multimesh hp-FEM to interpolation and projection methods for spatial coupling of thermal and neutron diffusion calculations

    Czech Academy of Sciences Publication Activity Database

    Dubcová, Lenka; Šolín, Pavel; Hansen, G.; Park, H.

    2011-01-01

    Roč. 4, č. 230 (2011), s. 1182-1197 ISSN 0021-9991 R&D Projects: GA AV ČR IAA100760702 Institutional research plan: CEZ:AV0Z20570509 Keywords : reactormultiphysics simulation * coupled diffusion * multiphysics error Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 2.310, year: 2011 http://www.sciencedirect.com/science/article/pii/S0021999110005905

  7. Development of safety analysis methodology for moderator system failure of CANDU-6 reactor by thermal-hydraulics/physics coupling

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jong Hyun, E-mail: jhkim@actbest.com [Department of Nuclear and Quantum Engineering, Korea Advanced Institute of Science and Technology, 373-1, Guseong-dong, Yuseong-gu, Daejeon 305-701 (Korea, Republic of); ACT Co., Ltd, 705 Gwanpyeong-dong, Yuseong-gu, Daejeon 305-509 (Korea, Republic of); Jin, Dong Sik [ACT Co., Ltd, 705 Gwanpyeong-dong, Yuseong-gu, Daejeon 305-509 (Korea, Republic of); Chang, Soon Heung [Department of Nuclear and Quantum Engineering, Korea Advanced Institute of Science and Technology, 373-1, Guseong-dong, Yuseong-gu, Daejeon 305-701 (Korea, Republic of)

    2013-10-15

    Highlights: • Developed new safety analysis methodology of moderator system failures for CANDU-6. • The new methodology used the TH-physics coupling concept. • Thermalhydraulic code is CATHENA, physics code is RFSP-IST. • Moderator system failure ends to the subcriticality through self-shutdown. -- Abstract: The new safety analysis methodology for the CANDU-6 nuclear power plant (NPP) moderator system failure has been developed by using the coupling technology with the thermalhydraulic code, CATHENA and reactor core physics code, RFSP-IST. This sophisticated methodology can replace the legacy methodology using the MODSTBOIL and SMOKIN-G2 in the field of the thermalhydraulics and reactor physics, respectively. The CATHENA thermalhydraulic model of the moderator system can simulate the thermalhydraulic behaviors of all the moderator systems such as the calandria tank, head tank, moderator circulating circuit and cover gas circulating circuit and can also predict the thermalhydraulic property of the moderator such as moderator density, temperature and water level in the calandria tank as the moderator system failures go on. And these calculated moderator thermalhydraulic properties are provided to the 3-dimensional neutron kinetics solution module – CERBRRS of RFSP-IST as inputs, which can predict the change of the reactor power and provide the calculated reactor power to the CATHENA. These coupling calculations are performed at every 2 s time steps, which are equivalent to the slow control of CANDU-6 reactor regulating systems (RRS). The safety analysis results using this coupling methodology reveal that the reactor operation enters into the self-shutdown mode without any engineering safety system and/or human interventions for the postulated moderator system failures of the loss of heat sink and moderator inventory, respectively.

  8. Electro-thermal vibration of a smart coupled nanobeam system with an internal flow based on nonlocal elasticity theory

    Energy Technology Data Exchange (ETDEWEB)

    Atabakhshian, V.; Shooshtari, A.; Karimi, M., E-mail: karimi_mh@yahoo.com

    2015-01-01

    In this study, nonlinear vibration and stability of a fluid-conveying nanotube (FCNT), elastically coupled to a smart piezoelectric polymeric beam (PPB) is investigated based on nonlocal elasticity theory, Euler–Bernoulli beam model and energy approach. In order to obtain an active instability control of FCNT, the PPB is longitudinally polarized as an actuator while in the absence of an imposed electric field it is also possible to be used as an alarm biosensor. Simulating the above smart coupled nanobeam system alike the double nanobeam systems (which are relatively developed by other authors) leads to obtain nonlinear differential equations of motion. The linear natural and damping frequencies are achieved by ignoring all the system nonlinearities which are then considered to obtain nonlinear frequencies using an iterative method. The effects of geometric nonlinearity, small scale parameter, coupled medium constants, Knudsen number, temperature change, aspect ratio and external applied voltage on critical flow velocity are studied in details. It is concluded that applying an electric voltage on PPB will increase the stability of FCNT. It is hoped that this research will provide a new approach to smart instability control of FCNTs which is no yet reported.

  9. New insights into properties of large-N holographic thermal QCD at finite gauge coupling at (the non-conformal/next-to) leading order in N

    Energy Technology Data Exchange (ETDEWEB)

    Sil, Karunava; Misra, Aalok [Indian Institute of Technology, Department of Physics, Roorkee, Uttarakhand (India)

    2016-11-15

    It is believed that large-N thermal QCD laboratories like strongly coupled QGP (sQGP) require not only a large 't Hooft coupling but also a finite gauge coupling (Natsuume, String theory and quark-gluon plasma. arXiv:hep-ph/0701201, 2007). Unlike almost all top-down holographic models in the literature, holographic large-N thermal QCD models, based on this assumption, therefore necessarily require addressing this limit from M-theory. This was initiated in Dhuria and Misra (JHEP 1311:001, 2013) which presented a local M-theory uplift of the string theoretic dual of large-N thermal QCD-like theories at finite gauge/string coupling of Mia et al. (Nucl. Phys. B 839:187, arXiv:0902.1540 [hep-th], 2010) (g{sub s} coupling, have been entirely missing in the literature. In this paper we largely address the following two non-trivial issues pertaining to the same. First, up to LO in N (the number of D3-branes), by calculating the temperature dependence of the thermal (and electrical) conductivity and the consequent deviation from the Wiedemann-Franz law, upon comparison with Garg et al. (Phys. Rev. Lett. 103:096402, 2009), we show that, remarkably, the results qualitatively mimic a 1+1-dimensional Luttinger liquid with impurities. Second, by looking at, respectively, the scalar, vector, and tensor modes of metric perturbations and using the prescription of Kovtun and Starinets (Phys. Rev. D 72:086009, arXiv:hep-th/0506184, 2005) for constructing appropriate gauge-invariant perturbations, we obtain the non-conformal corrections to the conformal results (but at finite g{sub s}), respectively, for the speed of sound, the shear mode diffusion constant, and the shear viscosity η (and (η)/(s)). The new insight gained is that it

  10. Simulators of tray distillation columns as tools for interpreting ...

    African Journals Online (AJOL)

    Simulators of tray distillation columns were used to provide technical guidelines for interpreting signals from gamma ray scans used for analysing malfunctions in distillation columns. The transmitted radiation intensities at 0.05 m intervals were determined from top to the bottom of simulators of tray distillation columns ...

  11. 27 CFR 24.183 - Use of distillates containing aldehydes.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Use of distillates containing aldehydes. 24.183 Section 24.183 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX... the fermentation of wine and then returned to the distilled spirits plant from which distillates were...

  12. 27 CFR 19.322 - Distillates containing extraneous substances.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Distillates containing extraneous substances. 19.322 Section 19.322 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX... therein for fermentation of wine to be used as distilling material at the distilled spirits plant from...

  13. Improvement of solar ethanol distillation using ultrasonic waves

    Directory of Open Access Journals (Sweden)

    Jaruwat Jareanjit

    2016-08-01

    Full Text Available This report presents a study on the use of ultrasonic waves in solar ethanol distillation to investigate the performance of ultrasonic waves at a frequency of 30 kHz and at 100 Watts that were installed in the inlet area of a 10-litre distillation tank. Based on the non-continuous distillation process (batch distillation, the experiment demonstrated that using ultrasonic waves in solar ethanol distillation caused the average concentration of hourly distilled ethanol to be higher than that of a normal system (solar ethanol distillation without ultrasonic wave at the same or higher distillation rate and hourly distillation volume. The ultrasonic wave was able to enhance the separation of ethanol from the solution (water-ethanol mixture through solar distillation. The amount of pure ethanol product from each distilled batch was clearly larger than the amount of product obtained from a normal system when the initial concentration of ethanol was lower than 50%v/v (% by volume, where an average of approximately 40% and 20% are obtained for an initial ethanol concentration of 10%v/v and 30%v/v, respectively. Furthermore, the distillation rate varied based on the solar radiation value.

  14. The Design and Manufacturing of Essential oil Distillation Plant for ...

    African Journals Online (AJOL)

    The adaptation of oil distillation technology for essential oil production is proposed for small scale industrial entrepreneur. Steam distillation method is selected considering the constraints to meet the socio-economic level of the rural community. The distillation plant has been modelled based on local resources and the first ...

  15. 27 CFR 27.31 - Warehouse receipts covering distilled spirits.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Warehouse receipts... BEER Dealer Registration and Recordkeeping § 27.31 Warehouse receipts covering distilled spirits. The sale of warehouse receipts for distilled spirits is equivalent to the sale of distilled spirits...

  16. Ekstraksi Minyak Atsiri Dari Akar Wangi Menggunakan Metode Steam - Hydro distillation dan Hydro distilation dengan Pemanas Microwave

    OpenAIRE

    Maulana M Al Hanief; Halim Al Mushawwir W; mahfud mahfud

    2013-01-01

    Penelitian ini bertujuan untuk memperoleh minyak atsiri dari akar wangi dengan modifikasi metode steam-hydro distillation dan hydro distillation yaitu menggunakan pemanasan microwave kemudian membandingkan hasilnya dengan penelitian sebelumnya. Modifikasi ini diharapkan lebih efisien dalam masalah lama penyulingan dan kualitas serta kuantitas rendemen minyak yang lebih baik dan banyak. Penelitian ini menggunakan dua metode yaitu steam-hydro distillation dan hydro distillation dengan pemanfaat...

  17. Ekstraksi Minyak Atsiri Dari Akar Wangi Menggunakan Metode Steam - Hydro Distillation Dan Hydro Distilation Dengan Pemanas Microwave

    OpenAIRE

    Hanief, Maulana M Al; W, Halim Al Mushawwir; mahfud, mahfud

    2013-01-01

    Penelitian ini bertujuan untuk memperoleh minyak atsiri dari akar wangi dengan modifikasi metode steam-hydro distillation dan hydro distillation yaitu menggunakan pemanasan microwave kemudian membandingkan hasilnya dengan penelitian sebelumnya. Modifikasi ini diharapkan lebih efisien dalam masalah lama penyulingan dan kualitas serta kuantitas rendemen minyak yang lebih baik dan banyak. Penelitian ini menggunakan dua metode yaitu steam-hydro distillation dan hydro distillation dengan pemanfaat...

  18. Water stress reduces evaporative cooling in hybrid poplars during hot drought: genotype influences degree of coupling between thermal stress and atmosphere

    Science.gov (United States)

    Fojtik, A. C.; Barnes, M.; Breshears, D. D.; Law, D.; Moore, D. J.

    2016-12-01

    Climate change is projected to increase global temperatures as well as the frequency and severity of drought in many regions worldwide. Potential consequences of hotter drought include widespread forest mortality and ecosystem reorganization. Of concern is the response of woody plants, especially commercially significant species, to drought exacerbated by higher temperatures. Quantifying the physiological effects of hot drought on woody plants can improve understanding of their limitations and ability to adapt to projected conditions. Here we test an association between water stress and thermal stress in two genotypes of hybrid poplar trees during a naturally occurring hot drought in Southern Arizona. Genotype 57-276 had small, diamond-shaped leaves, while genotype R-270 had large, rounded leaves. We hypothesized that the degree of coupling between the atmosphere and leaf temperature would vary with genotype due to the effects of leaf size on boundary layer. We compared pre-dawn water potential (Ψ) to the difference between leaf and air temperature (ΔT; a proxy for thermal stress), and meteorological variables including vapor pressure deficit (VPD), photosynthetically active radiation (PAR), and wind speed as the drought progressed. In both genotypes, Ψ was negatively related to ΔT when leaf temperature was higher than air temperature; this relationship was stronger in the large leaf genotype than the small leaf genotype. Leaves from highly stressed plants were the hottest compared to ambient air temperature. This suggests that water stress results in a reduction in leaf transpiration and associated evaporative cooling. Each genotype also had unique factors affecting ΔT. The small leaf genotype was more tightly coupled to the atmosphere, with ΔT influenced by PAR, and wind speed. This is consistent with smaller, diamond-shaped leaves, which result in a smaller leaf boundary layer that is more sensitive to atmospheric conditions. For the large leaf genotype,

  19. Innovative Vacuum Distillation for Magnesium Recycling

    Science.gov (United States)

    Zhu, Tianbai; Li, Naiyi; Mei, Xiaoming; Yu, Alfred; Shang, Shixiang

    Magnesium recycling now becomes a very important subject as magnesium consumption increases fast around the world. All commonly used magnesium die-casting alloys can be recycled and recovered to the primary metal quality. The recycled materials may be comprised of biscuits, sprues, runners, flash, overflows, dross, sludge, scrap parts, and old parts that are returned from service, An innovative magnesium recycle method, vacuum distillation, is developed and proved out to be able to recycle magnesium scraps, especially machining chips, oily magnesium, smelting sludge, dross or the mixture. With this process at a specific temperature and environment condition, magnesium in scraps can be gasified and then solidified to become crystal magnesium crown. This `recycled' magnesium crown is collected and used as the raw material of magnesium alloys. The experimental results show the vacuum distillation is a feasible and plausible method to recycle magnesium. Further, the cost analysis will be addressed in this paper.

  20. Hydrogen isotope separation by cryogenic distillation method

    International Nuclear Information System (INIS)

    Hayakawa, Nobuo; Mitsui, Jin

    1987-01-01

    Hydrogen isotope separation in fusion fuel cycle and tritium recovery from heavy water reactor are very important, and therefore the early establishment of these separation techniques are desired. The cryogenic distillation method in particular is promising for the separation of hydrogen isotope and the recovery of high concentrated tritium. The studies of hydrogen isotope separation by cryogenic distillation method have been carried out by using the experimental apparatus made for the first time in Japan. The separation of three components (H 2 -HD-D 2 ) under total reflux conditions was got by using the packing tower of 500 mm height. It was confirmed that the Height Equivalent Theoretical Plate (HETP) was 20 - 30 mm for the vapor's line velocity of 20 - 80 mm/s. (author)

  1. Companded total condensation loxboil air distillation

    International Nuclear Information System (INIS)

    Erickson, D.C.

    1989-01-01

    This patent describes a dual pressure cryogenic distillation process for producing gaseous oxygen from a supply of compressed and cleaned air, comprising: a. cooling a major fraction of the compressed and cleaned air; b. rectifying the major fraction in a high pressure rectifier to liquid nitrogen overhead product and kettle liquid bottom product; c. distilling the kettle liquid in a low pressure column to liquid oxygen bottom product and gaseous nitrogen overhead product; d. working expanding a compensating vapor comprised of at least 77% N/sub 2/ thereby producing refrigeration; and e. further compressing the remaining minor fraction comprising no more than about 30% of the compressed, cleaned warm air in a compressor powered by the expansion

  2. Contact structure for use in catalytic distillation

    Science.gov (United States)

    Jones, Jr., Edward M.

    1984-01-01

    A method for conducting catalytic chemical reactions and fractionation of the reaction mixture comprising feeding reactants into a distillation column reactor contracting said reactant in liquid phase with a fixed bed catalyst in the form of a contact catalyst structure consisting of closed porous containers containing the catatlyst for the reaction and a clip means to hold and support said containers, which are disposed above, i.e., on the distillation trays in the tower. The trays have weir means to provide a liquid level on the trays to substantially cover the containers. In other words, the trays function in their ordinary manner with the addition thereto of the catalyst. The reaction mixture is concurrently fractionated in the column.

  3. Experimental entanglement distillation of mesoscopic quantum states

    DEFF Research Database (Denmark)

    Dong, Ruifang; Lassen, Mikael Østergaard; Heersink, Joel

    2008-01-01

    The distribution of entangled states between distant parties in an optical network is crucial for the successful implementation of various quantum communication protocols such as quantum cryptography, teleportation and dense coding(1-3). However, owing to the unavoidable loss in any real optical...... channel, the distribution of loss-intolerant entangled states is inevitably afflicted by decoherence, which causes a degradation of the transmitted entanglement. To combat the decoherence, entanglement distillation, a process of extracting a small set of highly entangled states from a large set of less...... entangled states, can be used(4-14). Here we report on the distillation of deterministically prepared light pulses entangled in continuous variables that have undergone non-Gaussian noise. The entangled light pulses(15-17) are sent through a lossy channel, where the transmission is varying in time similarly...

  4. Mathematical modeling of alcohol distillation columns

    Directory of Open Access Journals (Sweden)

    Ones Osney Pérez

    2011-04-01

    Full Text Available New evaluation modules are proposed to extend the scope of a modular simulator oriented to the sugar cane industry, called STA 4.0, in a way that it can be used to carry out x calculation and analysis in ethanol distilleries. Calculation modules were developed for the simulation of the columns that are combined in the distillation area. Mathematical models were supported on materials and energy balances, equilibrium relations and thermodynamic properties of the ethanol-water system. Ponchon-Savarit method was used for the evaluation of the theoretical stages in the columns. A comparison between the results using Ponchon- Savarit method and those obtained applying McCabe-Thiele method was done for a distillation column. These calculation modules for ethanol distilleries were applied to a real case for validation.

  5. A coupled 3-D kinetics/system thermal-hydraulic analysis of main steam line break accident for Optimized Power Reactor 1000

    International Nuclear Information System (INIS)

    Jin, Yung Kwon; Choi, Chul Jin; Kim, Eun Kee; Lee, Sang Yong

    2006-01-01

    This paper presents the results of the coupled 3-D neutronics/thermal-hydraulic analysis of hypothetical main steam line break (MSLB) accident for Optimized Power Reactor 1000. One of the major concerns of this accident is a return-to-power occurrence accompanied with extremely large radial peaking near the stuck Control Element Assembly (CEA). The conventional point kinetics application does not properly account for this kind of asymmetric and local core behavior. Therefore, the current licensing method of point kinetics application introduces some uncertainties and conservatisms in the physics parameters generation, e.g., the static net scram rod worth, moderator cooldown reactivity, Doppler reactivity, and a 3-D peaking factor. The recently developed UNICORN-TM code system is applied for the 3-D coupled calculation, where neutronics code MASTER is coupled with the best-estimate system transient code RETRAN. The 3-D coupled results were assessed in comparison with those by point kinetics application using stand-alone RETRAN application. To quantify the 3-D reactivity benefits over point kinetics, both calculations assumed the accidents to be initiated from the same core state, e.g., end of cycle burnup, fuel and CEA configuration with the same initial moderator and Doppler temperature coefficient, and with initial system thermal-hydraulic condition. The core physics parameters required for point kinetics application were produced using MASTER with the method and procedure consistent with the current licensing application. The occurrence of return-to-power was simulated by intentionally reducing the net CEA worth in order to assess the spatial power distribution and local T-H effect on the dynamic reactivity feedback. The results have demonstrated that the 3-D analysis removes some of the conservatisms inherent in point kinetics analysis mainly caused by the inability to properly account for local reactivity feedback effects during return-to-power transient

  6. Photothermal Membrane Distillation for Seawater Desalination.

    Science.gov (United States)

    Politano, Antonio; Argurio, Pietro; Di Profio, Gianluca; Sanna, Vanna; Cupolillo, Anna; Chakraborty, Sudip; Arafat, Hassan A; Curcio, Efrem

    2017-01-01

    Thermoplasmonic effects notably improve the efficiency of vacuum membrane distillation, an economically sustainable tool for high-quality seawater desalination. Poly(vinylidene fluoride) (PVDF) membranes filled with spherical silver nanoparticles are used, whose size is tuned for the aim. With the addition of plasmonic nanoparticles in the membrane, the transmembrane flux increases by 11 times, and, moreover, the temperature at the membrane interface is higher than bulk temperature. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Experimental study of diffuse ceiling ventilation coupled with a thermally activated building construction in an office room

    DEFF Research Database (Denmark)

    Zhang, Chen; Heiselberg, Per Kvols; Pomianowski, Michal Zbigniew

    2015-01-01

    This paper presents and analyses the performance of an integrated system with diffuse ceiling ventilation and a thermally activated building construction. A full-scale experiment is carried out in a hot box with an office setup. The performance of the integrated system is evaluated under differen...... throughout the entire ceiling area and the radiation cooling potential of diffuse ceiling is not sufficient. Thus, a further study should be conducted on optimizing diffuse ceiling and plenum design.......This paper presents and analyses the performance of an integrated system with diffuse ceiling ventilation and a thermally activated building construction. A full-scale experiment is carried out in a hot box with an office setup. The performance of the integrated system is evaluated under different...... the opposite effect on energy performance when TABS is activated in heating or cooling mode. Finally, the air temperature distribution in the plenum and the surface temperature distribution of the diffuse ceiling point out that the air does not perfectly mix in the plenum, the air is not evenly distributed...

  8. Biocatalytic desulfurization of petroleum and middle distillates

    International Nuclear Information System (INIS)

    Monticello, D.J.

    1993-01-01

    Biocatalytic Desulfurization (BDS) represents an alternative approach to the reduction of sulfur in fossil fuels. The objective is to use bacteria to selectively remove sulfur from petroleum and middle distillate fractions, without the concomitant release of carbon. Recently, bacteria have been developed which have the ability to desulfurize dibenzothiophene (DBT) and other organosulfur molecules. These bacteria are being developed for use in a biocatalyst-based desulfurization process. Analysis of preliminary conceptual engineering designs has shown that this process has the potential to complement conventional technology as a method to temper the sulfur levels in crude oil, or remove the recalcitrant sulfur in middle distillates to achieve the deep desulfurization mandated by State and Federal regulations. This paper describes the results of initial feasibility studies, sensitivity analyses and conceptual design work. Feasibility studies with various crude oils and middle distillates achieved unoptimized desulfurization levels of 40-80%. Sensitivity analyses indicate that total desulfurization costs of about $3.00 per barrel for crude oil and less than $2.00 per barrel for diesel are possible. Key criteria for commercial success of the process include the cost and half-life of the biocatalyst, residence time in the reactor, oil/water ratios required to extract the sulfur and the disposition of the separated sulfur products. 9 refs., 3 figs

  9. Microfluidic distillation chip for methanol concentration detection.

    Science.gov (United States)

    Wang, Yao-Nan; Liu, Chan-Chiung; Yang, Ruey-Jen; Ju, Wei-Jhong; Fu, Lung-Ming

    2016-03-17

    An integrated microfluidic distillation system is proposed for separating a mixed ethanol-methanol-water solution into its constituent components. The microfluidic chip is fabricated using a CO2 laser system and comprises a serpentine channel, a boiling zone, a heating zone, and a cooled collection chamber filled with de-ionized (DI) water. In the proposed device, the ethanol-methanol-water solution is injected into the microfluidic chip and driven through the serpentine channel and into the collection chamber by means of a nitrogen carrier gas. Following the distillation process, the ethanol-methanol vapor flows into the collection chamber and condenses into the DI water. The resulting solution is removed from the collection tank and reacted with a mixed indicator. Finally, the methanol concentration is inversely derived from the absorbance measurements obtained using a spectrophotometer. The experimental results show the proposed microfluidic system achieves an average methanol distillation efficiency of 97%. The practicality of the proposed device is demonstrated by detecting the methanol concentrations of two commercial fruit wines. It is shown that the measured concentration values deviate by no more than 3% from those obtained using a conventional bench top system. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. Aromatic saturation of distillates. An overview

    International Nuclear Information System (INIS)

    Cooper, Barry H.; Donnis, Bjoern B.L.

    1996-01-01

    The saturation of aromatic compounds in distillate fractions and in particular in diesel fuel has received considerable attention in recent years. A high aromatic content is associated with poor fuel quality, giving a low cetane number in diesel fuel and a high smoke point in jet fuel. There is also evidence that particulate emissions in diesel exhaust gases correlate with the aromatic content of the fuel. New legislation has been introduced to limit aromatics in diesel fuel and this has led to new catalyst and process developments for aromatic saturation. This paper gives an overview of these developments. The types of aromatic compounds found in distillate streams are described, and the kinetics of both single (model) compounds and groups of compounds as found in industrial feedstocks are discussed. Both supported metal sulfide and supported noble metal catalysts are used industrially and the paper outlines the role of the active species in these catalysts and compares reaction conditions used for each. The tolerance of different catalyst systems towards sulfur and nitrogen in the feed is dealt with in some detail. Commercial processes employ either single- or dual-stage catalyst systems depending on the nature of the aromatic saturation catalyst. The paper considers the merits of different process configurations. The paper concludes with a brief survey of possible future applications for distillate aromatic saturation catalysts

  11. Heating oil, distillates and residuals outlook

    International Nuclear Information System (INIS)

    Ervin, M.J.

    2004-01-01

    M.J. Ervin and Associates offers strategic planning support to the downstream petroleum industry in terms of price market monitoring, market analysis, media commentary and benchmarking of marketing operations. This presentation included graphs depicting supply and demand for heating oil distillates and residuals from the mid 1990s to 2004. It was noted that the long-term decline in residuals demand in the United States and Canada are due to environmental issues, the use of natural gas as an alternative, and the increasing complexity of refineries. Graphs depicting market impacts of refinery utilization and inventory trends showed that middle distillate production will increase at the expense of gasoline production. Middle distillates and gasoline markets will be more sensitive to supply disruptions, resulting in more frequent price spikes. Inventory trends indicate a greater reliance on product imports. The demand for heating fuel has stabilized due to the continued penetration of natural gas in eastern states and provinces. The demand for diesel fuel has growth 1.5 to 2 per cent while the demand for jet fuel has remained relatively flat and depends greatly on the growth of the gross national product (GNP). tabs., figs

  12. A More Efficient Contextuality Distillation Protocol

    Science.gov (United States)

    Meng, Hui-xian; Cao, Huai-xin; Wang, Wen-hua; Fan, Ya-jing; Chen, Liang

    2017-12-01

    Based on the fact that both nonlocality and contextuality are resource theories, it is natural to ask how to amplify them more efficiently. In this paper, we present a contextuality distillation protocol which produces an n-cycle box B ∗ B ' from two given n-cycle boxes B and B '. It works efficiently for a class of contextual n-cycle (n ≥ 4) boxes which we termed as "the generalized correlated contextual n-cycle boxes". For any two generalized correlated contextual n-cycle boxes B and B ', B ∗ B ' is more contextual than both B and B '. Moreover, they can be distilled toward to the maximally contextual box C H n as the times of iteration goes to infinity. Among the known protocols, our protocol has the strongest approximate ability and is optimal in terms of its distillation rate. What is worth noting is that our protocol can witness a larger set of nonlocal boxes that make communication complexity trivial than the protocol in Brunner and Skrzypczyk (Phys. Rev. Lett. 102, 160403 2009), this might be helpful for exploring the problem that why quantum nonlocality is limited.

  13. Effect of succinonitrile on electrical, structural, optical, and thermal properties of [poly(ethylene oxide)-succinonitrile]/LiI–I2 redox-couple solid polymer electrolyte

    International Nuclear Information System (INIS)

    Gupta, Ravindra Kumar; Rhee, Hee-Woo

    2012-01-01

    Effect of succinonitrile on electrical, structural, optical, and thermal properties of [poly(ethylene oxide)-succinonitrile]/LiI–I 2 redox-couple solid polymer electrolyte is reported for the first time. For the poly(ethylene oxide)-succinonitrile blend-based electrolyte electrical conductivity was noted as high as ∼3 × 10 −4 S cm −1 at 25 °C, which is an order of magnitude higher than that of pure poly(ethylene oxide)-based electrolyte. It also exhibited relatively better pseudo-activation energy (∼0.08 eV). X-ray diffractometry, polarized optical microscopy, and differential scanning calorimetry studies revealed that succinonitrile is helpful in reducing the poly(ethylene oxide) crystallinity due to its plasticizing property. FT-IR study showed significant modification of the poly(ethylene oxide) chain conformation due to the succinonitrile.

  14. Overstability for surface tension and coupled buoyancy-driven instability in a horizontal liquid layer - Toward the understanding of thermal lens oscillations

    Science.gov (United States)

    Gouesbet, G.; Maquet, J.

    1987-06-01

    The overstability for surface tension and coupled buoyancy-driven instability in a horizontal liquid layer, with very general conditions, is studied. A linear formulation to compute the critical quantities is established. Numerical results are given and compared with overstability experiments in which a free surface is heated by a controlled hot-wire located near and below it. When correctly presented in terms of well chosen reduced quantities, theoretical and experimental results agree very well, showing that there is an analogy between the theoretical problem (horizontal liquid layer, basic conductive state) and the experimental situation (hot-wire heating, basic convective state). Disagreements are pointed out to stress the limitations of the analogy. The original motivation of the work is the understanding of thermal lens oscillations produced when heating below the free surface is carried out using a laser beam.

  15. HETP evaluation of structured packing distillation column

    Directory of Open Access Journals (Sweden)

    A. E. Orlando Jr.

    2009-09-01

    Full Text Available Several tests with a hydrocarbon mixture of known composition (C8-C14, obtained from DETEN Chemistry S.A., have been performed in a laboratory distillation column, having 40mm of nominal diameter and 2.2m high, with internals of Sulzer DX gauze stainless steel structured packing. The main purpose of this work was to evaluate HETP of a structured packing laboratory scale distillation column, operating continuously. Six HETP correlations available in the literature were compared in order to find out which is the most appropriate for structured packing columns working with medium