WorldWideScience

Sample records for external heat load

  1. Divertor heat load in ASDEX Upgrade L-mode in presence of external magnetic perturbation

    Science.gov (United States)

    Faitsch, M.; Sieglin, B.; Eich, T.; Herrmann, A.; Suttrop, W.; the ASDEX Upgrade Team

    2017-09-01

    Power exhaust is one of the major challenges for a future fusion device. Applying a non-axisymmetric external magnetic perturbation is one technique that is studied in order to mitigate or suppress large edge localized modes which accompany the high confinement regime in tokamaks. The external magnetic perturbation induces breaking in the axisymmetry of a tokamak and leads to a 2D heat flux pattern on the divertor target. The 2D heat flux pattern at the outer divertor target is studied on ASDEX Upgrade in stationary L-mode discharges. The amplitude of the 2D characteristic of the heat flux depends on the alignment between the field lines at the edge and the vacuum response of the applied magnetic perturbation spectrum. The 2D characteristic reduces with increasing density. The increasing divertor broadening, S, with increasing density is proposed as the main actuator. This is supported by a generic model using field line tracing and the vacuum field approach that is in quantitative agreement with the measured heat flux. The perturbed heat flux, averaged over a full toroidal rotation of the magnetic perturbation, is identical to the non-perturbed heat flux without magnetic perturbation. The transport qualifiers, power fall-off length {λ }q and divertor broadening, S, are the same within the uncertainty compared to the unperturbed reference. No additional cross field transport is observed.

  2. Combination of external loads

    Energy Technology Data Exchange (ETDEWEB)

    Frandsen, S.; Tarp Johansen, N.J.; Joergensen, H. [Forskningscenter Risoe, Roskilde (Denmark); Gravesen, H.; Soerensen, S.L. [Carl Bro, Glostrup (Denmark); Pedersen, J. [Elsam Engineering, Fredericia (Denmark); Zorn, R.; Hvidberg Knudsen, M. [DHI Water and Environment, Hoersholm (Denmark); Voelund, P. [Energi E2, Koebenhavn (Denmark)

    2003-09-01

    The project onbectives have been: To improve and consequently opimise the basis for design of offshore wind turbines. This is done through 1) mapping the wind, wave ice and current as well as correlations of these, and 2) by clarifyring how these external conditions transform into loads. A comprehensive effort has been made to get a thorough understanding of the uncertainties that govern the reliability of wind turbines with respect to wind and wave loading. One of the conclusions is that the reliability of wind turbines is generally lower, than the average reliability of building structures that are subject not only to environmental loads, which are very uncertain, but also imposed loads and self weight, which are less uncertain than the environmental loads. The implication is that, at the moment lower load partial safety factors for onshore wind turbines cannot be recommended. For the combination of wind and wave design loads the problem is twofold: 1). A very conservative design will be generated by simply adding the individual wind and wave design loads disregarding the independence of the short-term fluctuations of wind and wave loads. 2). Characteristic values and partial safety factors for wind and wave loads are not defined similarly. This implies that the reliability levels of turbine support structures subject to purely aerodynamic loads and subject to purely hydrodynamic loads are not identical. For the problem of combining aerodynamic design loads and hydrodynamic design loads two results have been obtained in the project: 1). By simple means a site specific wave load safety factor rendering the same safety level for hydrodynamic loads as for aerodynamic loads is derived, and next, by direct square summation of extreme fluctuations, the wind and wave load safety factors are weighted. 2). Under the assumptions that a deep water site is considered and that the wave loading is a fifty-fifty mix of drag and inertia the same wind and wave load safety factor

  3. Stabilization of Externally Slung Helicopter Loads

    Science.gov (United States)

    1974-08-01

    maximum slir^ Loao weighting and " vertical bounce ." The last question provides information on multi-point suspension of external 1oads. PHASE...an allowable cargo load, and vertical bounce . 110 Maximum Sling Load Weight The maximum sling load lifted by a CH-47B helicopter under...changes were made in their flying technique except for very smooth flight control inputs when lifting an ACL. Vertical Bounce Fifteen of the forty Army

  4. Cooling Load Estimation in the Building Based On Heat Sources

    Science.gov (United States)

    Chairani; Sulistyo, S.; Widyawan

    2017-05-01

    Heating, ventilation and air conditioning (HVAC) is the largest source of energy consumption. In this research, we discuss cooling load in the room by considering the different heat source and the number of occupancy. Energy cooling load is affected by external and internal heat sources. External cooling load in this discussion include convection outdoor/exterior using the DOE-2 algorithm, calculation of heat using Thermal Analysis Research Program (TARP), and Conduction Transfer Function (CTF). The internal cooling load is calculated based on the activity of the occupants in the office, a number of occupants, heat gain from lighting, and heat gain from electrics equipment. Weather data used is Surakarta weather and design day used is Jakarta design day. We use the ASHRAE standard for building materials and the metabolic of occupants while on the activity. The results show that the number of occupancies have an influence of cooling load. A large number of occupancy will cause the cooling load is great as well.

  5. APS high heat load monochromator

    Energy Technology Data Exchange (ETDEWEB)

    Lee, W.K.; Mills, D.

    1993-02-01

    This document contains the design specifications of the APS high heat load (HHL) monochromator and associated accessories as of February 1993. It should be noted that work is continuing on many parts of the monochromator including the mechanical design, crystal cooling designs, etc. Where appropriate, we have tried to add supporting documentation, references to published papers, and calculations from which we based our decisions. The underlying philosophy behind performance specifications of this monochromator was to fabricate a device that would be useful to as many APS users as possible, that is, the design should be as generic as possible. In other words, we believe that this design will be capable of operating on both bending magnet and ID beamlines (with the appropriate changes to the cooling and crystals) with both flat and inclined crystal geometries and with a variety of coolants. It was strongly felt that this monochromator should have good energy scanning capabilities over the classical energy range of about 4 to 20 keywith Si (111) crystals. For this reason, a design incorporating one rotation stage to drive both the first and second crystals was considered most promising. Separate rotary stages for the first and second crystals can sometimes provide more flexibility in their capacities to carry heavy loads (for heavily cooled first crystals or sagittal benders of second crystals), but their tuning capabilities were considered inferior to the single axis approach.

  6. Dense Molecular Cores Being Externally Heated

    CERN Document Server

    Kim, Gwanjeong; Gopinathan, Maheswar; Jeong, Woong-Seob; Kim, Mi-Ryang

    2016-01-01

    We present results of our study on eight dense cores, previously classified as starless, using infrared (3-160 {\\micron}) imaging observations with \\textit{AKARI} telescope and molecular line (HCN and N$_2$H$^+$) mapping observations with \\textit{KVN} telescope. Combining our results with the archival IR to mm continuum data, we examined the starless nature of these eight cores. Two of the eight cores are found to harbor faint protostars having luminosity of $\\sim0.3-4.4$ L$_{\\odot}$. The other six cores are found to remain as starless and probably are in a dynamically transitional state. The temperature maps produced using multi-wavelength images show an enhancement of about 3-6 K towards the outer boundary of these cores, suggesting that they are most likely being heated externally by nearby stars and/or interstellar radiation fields. Large virial parameters and an over-dominance of red asymmetric line profiles over the cores may indicate that the cores are set into either an expansion or an oscillatory mot...

  7. Heat Load Estimator for Smoothing Pulsed Heat Loads on Supercritical Helium Loops

    Science.gov (United States)

    Hoa, C.; Lagier, B.; Rousset, B.; Bonnay, P.; Michel, F.

    Superconducting magnets for fusion are subjected to large variations of heat loads due to cycling operation of tokamaks. The cryogenic system shall operate smoothly to extract the pulsed heat loads by circulating supercritical helium into the coils and structures. However the value of the total heat loads and its temporal variation are not known before the plasma scenario starts. A real-time heat load estimator is of interest for the process control of the cryogenic system in order to anticipate the arrival of pulsed heat loads to the refrigerator and finally to optimize the operation of the cryogenic system. The large variation of the thermal loads affects the physical parameters of the supercritical helium loop (pressure, temperature, mass flow) so those signals can be used for calculating instantaneously the loads deposited into the loop. The methodology and algorithm are addressed in the article for estimating the heat load deposition before it reaches the refrigerator. The CEA patented process control has been implemented in a Programmable Logic Controller (PLC) and has been successfully validated on the HELIOS test facility at CEA Grenoble. This heat load estimator is complementary to pulsed load smoothing strategies providing an estimation of the optimized refrigeration power. It can also effectively improve the process control during the transient between different operating modes by adjusting the refrigeration power to the need. This way, the heat load estimator participates to the safe operation of the cryogenic system.

  8. THE PROBLEM OF AN EXTERNAL CIRCULAR CRACK UNDER ASYMMETRIC LOADINGS

    Institute of Scientific and Technical Information of China (English)

    王银邦

    2001-01-01

    Using the boundary integral equation method, the problem of an external circular crack in a three-dimensional infinite elastic body under asymmetric loadings is investigated. The two- dimensional singular boundary integral equations of the problem were reduced to a system of Abel integral equations by means of Fourier series and hypergeometric functions. The exact solutions of stress intensity factors are obtained for the problem of an external circular crack under asymmetric loadings, which are even more universal than the results obtained by the use of Hankel transform method. The results demonstrate that the boundary integral equation method has great potential as a new analytic method.

  9. Load Management in District Heating Operation

    DEFF Research Database (Denmark)

    Li, Hongwei; Wang, Stephen Jia

    2015-01-01

    heating load can be reduced through building demand side management. The building thermal mass can be used to shift the heating supply under the circumstance without jeopardizing the consumer thermal comfort. In this paper, the multi-agent framework is applied to a simplified building dynamic model...

  10. Cost minimization of generation, storage, and new loads, comparing costs with and without externalities

    DEFF Research Database (Denmark)

    Noel, Lance Douglas; Brodie, Joseph; Kempton, Willett

    2017-01-01

    G) technology, and building heat) are modeled within the PJM Interconnection. The corresponding electric systems are then operated and constrained to meet the load every hour over four years. The total cost of each energy system is calculated, both with and without externalities, to find the least...... cost energy systems. Using today’s costs of conventional and renewable electricity and without adding any externalities, the cost-minimum system includes no renewable generation, but does include EVs. When externalities are included, however, the most cost-effective to system covers 50% of the electric...... load with renewable energy and runs reliably without need for either new conventional generation or purpose-built storage. The three novel energy policy implications of this research are: (1) using today’s cost of renewable electricity and estimates of externalities, it is cost effective to implement...

  11. Effects of aqueous humor hydrodynamics on human eye heat transfer under external heat sources.

    Science.gov (United States)

    Tiang, Kor L; Ooi, Ean H

    2016-08-01

    The majority of the eye models developed in the late 90s and early 00s considers only heat conduction inside the eye. This assumption is not entirely correct, since the anterior and posterior chambers are filled aqueous humor (AH) that is constantly in motion due to thermally-induced buoyancy. In this paper, a three-dimensional model of the human eye is developed to investigate the effects AH hydrodynamics have on the human eye temperature under exposure to external heat sources. If the effects of AH flow are negligible, then future models can be developed without taking them into account, thus simplifying the modeling process. Two types of external thermal loads are considered; volumetric and surface irradiation. Results showed that heat convection due to AH flow contributes to nearly 95% of the total heat flow inside the anterior chamber. Moreover, the circulation inside the anterior chamber can cause an upward shift of the location of hotspot. This can have significant consequences to our understanding of heat-induced cataractogenesis. Copyright © 2016 IPEM. Published by Elsevier Ltd. All rights reserved.

  12. Residential Variable-Capacity Heat Pumps Sized to Heating Loads

    Energy Technology Data Exchange (ETDEWEB)

    Munk, Jeffrey D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Jackson, Roderick K. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Odukomaiya, Adewale [Georgia Inst. of Technology, Atlanta, GA (United States); Gehl, Anthony C. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2014-01-01

    Variable capacity heat pumps are an emerging technology offering significant energy savings potential and improved efficiency. With conventional single-speed systems, it is important to appropriately size heat pumps for the cooling load as over-sizing would result in cycling and insufficient latent capacity required for humidity control. These appropriately sized systems are often under-sized for the heating load and require inefficient supplemental electric resistance heat to meet the heating demand. Variable capacity heat pumps address these shortcomings by providing an opportunity to intentionally size systems for the dominant heating season load without adverse effects of cycling or insufficient dehumidification in the cooling season. This intentionally-sized system could result in significant energy savings in the heating season, as the need for inefficient supplemental electric resistance heat is drastically reduced. This is a continuation of a study evaluating the energy consumption of variable capacity heat pumps installed in two unoccupied research homes in Farragut, a suburb of Knoxville, Tennessee. In this particular study, space conditioning systems are intentionally sized for the heating season loads to provide an opportunity to understand and evaluate the impact this would have on electric resistance heat use and dehumidification. The results and conclusions drawn through this research are valid and specific for portions of the Southeastern and Midwestern United States falling in the mixed-humid climate zone. While other regions in the U.S. do not experience this type of climate, this work provides a basis for, and can help understand the implications of other climate zones on residential space conditioning energy consumption. The data presented here will provide a framework for fine tuning residential building EnergyPlus models that are being developed.

  13. Residential Variable-Capacity Heat Pumps Sized to Heating Loads

    Energy Technology Data Exchange (ETDEWEB)

    Munk, Jeffrey D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Jackson, Roderick K. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Odukomaiya, Adewale [Georgia Inst. of Technology, Atlanta, GA (United States); Gehl, Anthony C. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2014-01-01

    Variable capacity heat pumps are an emerging technology offering significant energy savings potential and improved efficiency. With conventional single-speed systems, it is important to appropriately size heat pumps for the cooling load as over-sizing would result in cycling and insufficient latent capacity required for humidity control. These appropriately sized systems are often under-sized for the heating load and require inefficient supplemental electric resistance heat to meet the heating demand. Variable capacity heat pumps address these shortcomings by providing an opportunity to intentionally size systems for the dominant heating season load without adverse effects of cycling or insufficient dehumidification in the cooling season. This intentionally-sized system could result in significant energy savings in the heating season, as the need for inefficient supplemental electric resistance heat is drastically reduced. This is a continuation of a study evaluating the energy consumption of variable capacity heat pumps installed in two unoccupied research homes in Farragut, a suburb of Knoxville, Tennessee. In this particular study, space conditioning systems are intentionally sized for the heating season loads to provide an opportunity to understand and evaluate the impact this would have on electric resistance heat use and dehumidification. The results and conclusions drawn through this research are valid and specific for portions of the Southeastern and Midwestern United States falling in the mixed-humid climate zone. While other regions in the U.S. do not experience this type of climate, this work provides a basis for, and can help understand the implications of other climate zones on residential space conditioning energy consumption. The data presented here will provide a framework for fine tuning residential building EnergyPlus models that are being developed.

  14. Problems with plastered external heat insulation. Probleme mit verputzter Aussenwaermedaemmung

    Energy Technology Data Exchange (ETDEWEB)

    Epple, H.; Foglia, A.; Preisig, H.; Pfefferkorn, J.

    1984-01-01

    Concerning execution, maintenance and service life, walls with plastered external heat insulation constitute an economic method. Owing to experience gained with plastered external heat insulation, it is possible today to provide reliable information on requirements made on ground material and operational execution. The author intends to contribute to a prevention of defects by giving concise examples. A survey on different types of external heat insulation is followed by a treatment of the problem areas of roof-edge connection, base end under ground, modernization of old buildings and cracks in plaster. Principal statements are made concerning steam diffusion, planning, materials and execution.

  15. Improving Automation Routines for Automatic Heating Load Detection in Buildings

    Directory of Open Access Journals (Sweden)

    Stephen Timlin

    2012-11-01

    Full Text Available Energy managers use weather compensation data and heating system cut off routines to reduce heating energy consumption in buildings and improve user comfort. These routines are traditionally based on the calculation of an estimated building load that is inferred from the external dry bulb temperature at any point in time. While this method does reduce heating energy consumption and accidental overheating, it can be inaccurate under some weather conditions and therefore has limited effectiveness. There remains considerable scope to improve on the accuracy and relevance of the traditional method by expanding the calculations used to include a larger range of environmental metrics. It is proposed that weather compensation and automatic shut off routines that are commonly used could be improved notably with little additional cost by the inclusion of additional weather metrics. This paper examines the theoretical relationship between various external metrics and building heating loads. Results of the application of an advanced routine to a recently constructed building are examined, and estimates are made of the potential savings that can be achieved through the use of the routines proposed.

  16. Elastic Stability of Concentric Tube Robots Subject to External Loads.

    Science.gov (United States)

    Ha, Junhyoung; Park, Frank C; Dupont, Pierre E

    2016-06-01

    Concentric tube robots, which are comprised of precurved elastic tubes that are concentrically arranged, are being developed for many medical interventions. The shape of the robot is determined by the rotation and translation of the tubes relative to each other, and also by any external forces applied by the environment. As the tubes rotate and translate relative to each other, elastic potential energy caused by tube bending and twisting can accumulate; if a configuration is not locally elastically stable, then a dangerous snapping motion may occur as energy is suddenly released. External loads on the robot also influence elastic stability. In this paper, we provide a second-order sufficient condition, and also a separate necessary condition, for elastic stability. Using methods of optimal control theory, we show that these conditions apply to general concentric tube robot designs subject to arbitrary conservative external loads. They can be used to assess the stability of candidate robot configurations. Our results are validated via comparison with other known stability criteria, and their utility is demonstrated by an application to stable path planning.

  17. Dynamic analysis of scraper conveyor operation with external loads

    Directory of Open Access Journals (Sweden)

    Świder Jerzy

    2017-01-01

    Full Text Available A load to an armoured face conveyor (AFC during coal mining is changeable and very difficult or even impossible to be predicted. Changes of the load to the upper scraper chain affect the load of the driving motor and generate changes in a scraper chain tension. Impact of increasing the external load to the upper scraper chain on the operation of electric motors and on the scraper chain tension is presented. The developed numerical model of the Rybnik 850 conveyor enabled identifying the places of the scraper chain high tension or places of its loosening. An impact of changing frequency of driving motor voltage on AFC’s operational conditions was tested and analysed using the AFC’s numerical model. During tests, tension of the scraper chain on the discharge end and the return end was recorded. High tension of the scraper chain and its loosening during the changeable load were also recorded on upward and downward transportation of run-of-mine material.

  18. Indirect solar loading of waste heat radiators

    Energy Technology Data Exchange (ETDEWEB)

    Kirkpatrick, R.C.; Tabor, J.E.; Lindman, E.L.; Cooper, A.J.

    1988-01-01

    Waste heat from space based power systems must ultimately be radiated away into space. The local topology around the radiators must be considered from two stand-points: the scattering of sunlight onto the surfaces of the radiator and the heat load that the radiator may put on near-by components of the system. A view factor code (SNAP) developed at Los Alamos allows the computation of the steady-state radiation environment for complex 3-D geometries. An example of the code's utility is given. 4 refs., 2 figs., 1 tab.

  19. Quasistatic Modeling of Concentric Tube Robots with External Loads.

    Science.gov (United States)

    Lock, Jesse; Laing, Genevieve; Mahvash, Mohsen; Dupont, Pierre E

    2010-12-03

    Concentric tube robots are a subset of continuum robots constructed by combining pre-curved elastic tubes. As the tubes are rotated and translated with respect to each other, their curvatures interact elastically, enabling control of the robot's tip configuration as well as the curvature along its length. This technology is projected to be useful in many types of minimally invasive medical procedures. Because these robots are flexible by design, they deflect considerably when applying forces to the external environment. Thus, in contrast to rigid-link robots, their kinematic and static force models are coupled. This paper derives a multi-tube quasistatic model that relates tube rotations and translations together with externally applied loads to robot shape and tip configuration. The model can be applied in robot design, procedure planning as well as control. For validation, the multi-tube model is compared experimentally to a computationally-efficient single-tube approximate model.

  20. The Effect of External Loads and Cyclic Loading on Normal Patellofemoral Joint Signals.

    Directory of Open Access Journals (Sweden)

    K. O. Ladly

    1993-07-01

    Full Text Available Pain over the anterior portion of the knee joint is a common clinical complaint. A condition known as 'chondromalacia patella' (softening of the cartilage under the patella, which frequently causes anterior knee pain is difficult to diagnose and monitor. Vibrations detected by a contact transducer over the patellofemoral joint may be useful in the assessment of chondromalacia patella. This paper utilised this technique known as vibroarthrography (VAG, to study two potential sources of variability of the normal patellofemoral joint signal. The effect of increased muscular force on the VAG signal was measured by externally loading the joint. The effect of load history (cyclic loading on the VAG signal was determined by comparing signals before, during, and after application of weights under similar cyclic loading conditions. Results indicated that external loading of the patellofemoral joint caused only minor signal variation. Cyclical loading of the joint, on the other hand, was determined to be a major source of variability of the normal patellofemoral joint signal, which must be controlled in future VAG tests.

  1. Analyzing Design Heating Loads in Superinsulated Buildings

    Energy Technology Data Exchange (ETDEWEB)

    Arena, Lois [Consortium for Advanced Residential Buildings, Norwalk, CT (United States)

    2015-06-16

    The U.S. Department of Energy’s Building America research team Consortium for Advanced Residential Buildings (CARB) worked with the EcoVillage cohousing community in Ithaca, New York, on the Third Residential EcoVillage Experience neighborhood. This communityscale project consists of 40 housing units—15 apartments and 25 single-family residences. Units range in size from 450 ft2 to 1,664 ft2 and cost from $80,000 for a studio apartment to $235,000 for a three- or four-bedroom single-family home. For the research component of this project, CARB analyzed current heating system sizing methods for superinsulated homes in cold climates to determine if changes in building load calculation methodology should be recommended. Actual heating energy use was monitored and compared to results from the Air Conditioning Contractors of America’s Manual J8 (MJ8) and the Passive House Planning Package software. Results from that research indicate that MJ8 significantly oversizes heating systems for superinsulated homes and that thermal inertia and internal gains should be considered for more accurate load calculations.

  2. The effect of external boundary conditions on condensation heat transfer in rotating heat pipes

    Science.gov (United States)

    Daniels, T. C.; Williams, R. J.

    1979-01-01

    Experimental evidence shows the importance of external boundary conditions on the overall performance of a rotating heat pipe condenser. Data are presented for the boundary conditions of constant heat flux and constant wall temperature for rotating heat pipes containing either pure vapor or a mixture of vapor and noncondensable gas as working fluid.

  3. TEM Pump With External Heat Source And Sink

    Science.gov (United States)

    Nesmith, Bill J.

    1991-01-01

    Proposed thermoelectric/electromagnetic (TEM) pump driven by external source of heat and by two or more heat pipe radiator heat sink(s). Thermoelectrics generate electrical current to circulate liquid metal in secondary loop of two-fluid-loop system. Intended for use with space and terrestrial dual loop liquid metal nuclear reactors. Applications include spacecraft on long missions or terrestrial beacons or scientific instruments having to operate in remote areas for long times. Design modified to include multiple radiators, converters, and ducts, as dictated by particular application.

  4. Analyzing Design Heating Loads in Superinsulated Buildings

    Energy Technology Data Exchange (ETDEWEB)

    Arena, Lois [Consortium for Advanced Residential Buildings, Norwalk, CT (United States)

    2015-06-01

    Super-insulated homes offer many benefits including improved comfort, reduced exterior noise penetration, lower energy bills, and the ability to withstand power and fuel outages under much more comfortable conditions than a typical home. While these homes aren't necessarily constructed with excessive mass in the form of concrete floors and walls, the amount of insulation and the increase in the thickness of the building envelope can lead to a mass effect, resulting in the structures ability to store much more heat than a code built home. This results in a very low thermal inertia making the building much less sensitive to drastic temperature swings thereby decreasing the peak heating load demand. During the winter of 2013/2014, CARB monitored the energy use of three homes in climate zone 6 in an attempt to evaluate the accuracy of two different mechanical system sizing methods for low load homes. Based on the results, it is recommended that internal and solar gains be included and some credit for thermal inertia be used in sizing calculations for super insulated homes.

  5. Cooling load optimization of an irreversible refrigerator with combined heat transfer

    Directory of Open Access Journals (Sweden)

    M. El Haj Assad

    2013-01-01

    Full Text Available In this work a mathematical model to study the performance of an irreversible refrigerator has been presented with the consideration of heat exchange by combined convection and radiation. The external irreversibility effects due to finite rate heat transfer as well as the effects of internal dissipations have been considered in the analysis. The relation between the cooling load and the coefficient of performance of the refrigerator has been derived. Furthermore an expression for the maximum cooling rate has been derived. The parameters that affect the cooling load have been investigated. The cooling load has been discussed and the effect of internal irreversibility has been investigated.

  6. CONVECTIVE HEAT TRANSFER IN CYCLONE DEVICE WITH EXTERNAL GAS RECIRCULATION

    Directory of Open Access Journals (Sweden)

    S. V. Karpov

    2016-01-01

    Full Text Available The article considers the convective heat transfer on the surface of a hollow cylinder or several billets in a cyclone device with the new principle of external gas recirculation. According to this principle, transport of coolant from the lateral surface of the chamber, where the temperature is the highest, in the axial region is being fulfilled due to the pressure drop between the wall and axial areas of cyclonic flow. Dependency analysis of average and local heat transfer coefficients from operational and geometrical parameters has been performed; the generalized similarity equations for the calculation of the latter have been suggested. It is demonstrated that in case of download of a cyclone chamber with several billets, the use of the considered scheme of the external recirculation due to the specific characteristics of aerodynamics practically does not lead to noticeable changes in the intensity of convective heat transfer. Both experimental data and the numerical simulation results obtained with the use of OpenFOAM platform were used in the work. The investigations fulfilled will expand the area of the use of cyclone heating devices.

  7. Externally heated valve engine a new approach to piston engines

    CERN Document Server

    Kazimierski, Zbyszko

    2016-01-01

    This book reports on a novel approach for generating mechanical energy from different, external heat sources using the body of a typical piston engine with valves. By presenting simple yet effective numerical models, the authors show how this new approach, which combines existing internal combustion technology with a lubrication system, is able to offer an economic solution to the problem of mechanical energy generation in piston engines. Their results also show that a stable heat generation process can be guaranteed outside of the engine. The book offers a detailed report on physical and numerical models of 4-stroke and 2-stroke versions of the EHVE together with different models of heat exchange, valves and results of their simulations. It also delivers the test results of an engine prototype run in laboratory conditions. By presenting a novel theoretical framework and providing readers with extensive knowledge of both the advantages and challenges of the method, this book is expected to inspire academic re...

  8. Hip abduction strength training in the clinical setting: with or without external loading?

    DEFF Research Database (Denmark)

    Bandholm, T; Weeke, Karen; Weinold, Christian;

    2010-01-01

    The side-lying hip abduction exercise is one of the most commonly used exercises in rehabilitation to increase hip abduction strength, and is often performed without external loading. The aim of this study was to compare the effect of 6 weeks of side-lying hip abduction training, with and without...... external loading, on hip abduction strength in healthy subjects. Thirty-one healthy, physically active men and women were included in a randomised controlled trial and allocated to side-lying hip abduction training, with or without external loading. Training without external loading was performed using...... only the weight of the leg as resistance, whereas training with external loading was performed with a relative load corresponding to 10 repetition maximum. Hip abduction strength was measured pre- and post-intervention. Isometric and eccentric hip abduction strength of the trained leg increased after...

  9. Static Heat Loads in the LHC Arc Cryostats: Final Assessment

    CERN Document Server

    Parma, V

    2010-01-01

    This note presents the final assessment of the static heat loads in the LHC arc cryostats, using different experimental methods during the first commissioning period in 2007. This assessment further develops and completes previous estimates made during the commissioning of sector 7_8 [1]. The estimate of the helium inventory, a prerequisite for the heat load calculation, is also presented. Heat loads to the cold mass are evaluated from the internal energy balance during natural as well as powered warm-ups of the helium baths in different subsector. The helium inventory is calculated from the internal energy balance during powered warm-ups and matched with previous assessments. Furthermore, heat loads to the thermal shield are estimated from the non-isothermal cooling of the supercritical helium in line E. The comparison of measured heat loads with previous estimates and with budgeted values is then presented, while their correlation with some important parameters like insulation vacuum pressure and some heat ...

  10. Heat loading limits for solid transuranic wastes storage

    Energy Technology Data Exchange (ETDEWEB)

    Spatz, T.L.

    1993-07-01

    Heat loading limits have been established for four storage configurations of TRU wastes. The calculations were performed assuming the worst case scenario whereby all the heat generated within a drum was generated within one ``cut`` and that this cut was located in the very center of the drum. Poly-boxes containing one HEPA filter were assumed to have a uniform heat generation throughout the filter. The maximum allowable temperatures were based on the materials in the containers. A comparison between the drum center temperature for a uniform heat load distribution and for the center temperature when the heat load is confined to one cut in the center of the drum is also illustrated. This comparison showed that the heat load of a particular drum can be more than doubled by distributing the sources of heat uniformly throughout the container.

  11. Evaluation of externally heated pulsed MPD thruster cathodes

    Science.gov (United States)

    Myers, Roger M.; Domonkos, Matthew; Gallimore, Alec D.

    1993-01-01

    Recent interest in solar electric orbit transfer vehicles (SEOTV's) has prompted a reevaluation of pulsed magnetoplasmadynamic (MPD) thruster systems due to their ease of power scaling and reduced test facility requirements. In this work the use of externally heated cathodes was examined in order to extend the lifetime of these thrusters to the 1000 to 3000 hours required for SEOTV missions. A pulsed MPD thruster test facility was assembled, including a pulse-forming network (PFN), ignitor supply and propellant feed system. Results of cold cathode tests used to validate the facility, PFN, and propellant feed system design are presented, as well as a preliminary evaluation of externally heated impregnated tungsten cathodes. The cold cathode thruster was operated on both argon and nitrogen propellants at peak discharge power levels up to 300 kW. The results confirmed proper operation of the pulsed thruster test facility, and indicated that large amounts of gas were evolved from the BaO-CaO-Al2O3 cathodes during activation. Comparison of the expected space charge limited current with the measured vacuum current when using the heated cathode indicate that either that a large temperature difference existed between the heater and the cathode or that the surface work function was higher than expected.

  12. Short-term heat load forecasting for single family houses

    DEFF Research Database (Denmark)

    Bacher, Peder; Madsen, Henrik; Nielsen, Henrik Aalborg;

    2013-01-01

    This paper presents a method for forecasting the load for space heating in a single-family house. The forecasting model is built using data from sixteen houses located in Sønderborg, Denmark, combined with local climate measurements and weather forecasts. Every hour the hourly heat load for each ...

  13. Compressibility measurements of gases using externally heated pressure vessels.

    Science.gov (United States)

    Presnall, D. C.

    1971-01-01

    Most of the data collected under conditions of high temperature and pressure have been determined using a thick-walled bomb of carefully measured and fixed volume which is externally heated by an electric furnace or a thermostatically controlled bath. There are numerous variations on the basic method depending on the pressure-temperature range of interest, and the particular gas or gas mixture being studied. The construction and calibration of the apparatus is discussed, giving attention to the pressure vessel, the volume of the bomb, the measurement of pressure, the control and measurement of temperature, and the measurement of the amount and composition of gas in the bomb.

  14. Design and Fabrication of Externally heated Copper Bromide Laser

    Directory of Open Access Journals (Sweden)

    J.P. Dudeja

    1993-04-01

    Full Text Available An externally-heated, longitudinally-discharged, low-repetition-rate copper bromide laser, was designed and fabricated. The green-coloured wavelength at 5106 A from this laser can be used for underwater ranging and detection of submerged objects. Several new changes in the design of discharge tube, heating technique, buffer-gas-flow sub-system and electrical circuit have been conceived and incorporated advantageously in our system. Various parameters, for example, the type of buffer gas and its flow rate, mixture of gases, temperature of the discharge tube, delay between dissociation and excitation pulses, dissociation and excitation energies, and various resonator configurations are being optimised to get the maximum output power/energy from the laser system.

  15. Comfort air temperature influence on heating and cooling loads of a residential building

    Science.gov (United States)

    Stanciu, C.; Șoriga, I.; Gheorghian, A. T.; Stanciu, D.

    2016-08-01

    The paper presents the thermal behavior and energy loads of a two-level residential building designed for a family of four, two adults and two students, for different inside comfort levels reflected by the interior air temperature. Results are intended to emphasize the different thermal behavior of building elements and their contribution to the building's external load. The most important contributors to the building thermal loss are determined. Daily heating and cooling loads are computed for 12 months simulation in Bucharest (44.25°N latitude) in clear sky conditions. The most important aspects regarding sizing of thermal energy systems are emphasized, such as the reference months for maximum cooling and heating loads and these loads’ values. Annual maximum loads are encountered in February and August, respectively, so these months should be taken as reference for sizing thermal building systems, in Bucharest, under clear sky conditions.

  16. Analytical study of the heat loss attenuation by clothing on thermal manikins under radiative heat loads

    NARCIS (Netherlands)

    Hartog, E.A. den; Havenith, G.

    2010-01-01

    For wearers of protective clothing in radiation environments there are no quantitative guidelines available for the effect of a radiative heat load on heat exchange. Under the European Union funded project ThermProtect an analytical effort was defined to address the issue of radiative heat load whil

  17. The Effect of External Factors on Consumption Electricity Loads Forecasting using Fuzzy Takagi-Sugeno Kang

    Directory of Open Access Journals (Sweden)

    Gayatri Dwi Santika

    2017-03-01

    Full Text Available This study applied Fuzzy Inference System Sugeno to forecast electrical load by considering the external factors. To see the accuracy of forecasting using Fuzzy Inference System Sugeno, then a comparison between the forecasting results of Fuzzy Inference System Sugeno using historical data with Fuzzy Inference System Sugeno using external factors was done. By using external factors method, resulted the smallest RMSE of 0762 and using historical data obtained error (RMSE of 1028. The results of the study came to the conclusion that Fuzzy Inference System Sugeno method using external factors to forecast the consumption of electrical load gives a better result than Fuzzy Inference System Sugeno using only historical data.

  18. Transient behavior of heat pipe with thermal energy storage under pulse heat loads

    Science.gov (United States)

    Chang, Ming-, Jr.

    1991-02-01

    Future space missions will require thermal transport devices with the ability to handle transient pulse heat loads. A novel design of a high-temperature axially grooved heat pipe (HP) which incorporates thermal energy storage (TES) to migrate pulse heat loads was presented. A phase-change material (PCM) which is encapsulated in cylindrical containers was used for the thermal energy storage. The transient response of the HP/TES system under two different types of pulse heat loads was studied analytically. The first type is pulse heat loads applied at the heat pipe evaporator, the second type is reversed-pulse heat loads applied at the condenser. In this research, a new three-dimensional alternating-direction-implicit (ADI) method was developed to model the heat conduction through the heat pipe wall and wicks, including the liquid flow in grooves. A very important characteristic of this new ADI method is that it is consistent with physical considerations. Compared with the well-known Brian's and Douglas's ADI methods, this new ADI method had higher accuracy and requires less computer storage. In the numerical solution of heat transfer problems with phase change (Stefan-type problem), a modified Pham's method which includes features from enthalpy and heat capacity methods was used to simulate the melting and solidification processes of the PCG. The vapor flow was assumed quasi-steady and one-dimensional, and was coupled with the evaporation and condensation on the heat pipe inside wall surface and the surfaces of the PCM containers. The transient responses of three different HP/TES configurations were compared: (1) a heat pipe with a large empty cylinder installed in the vapor core, (2) a heat pipe with a large PCM cylinder, and (3) a heat pipe with six small PCM cylinders. From the numerical results, it was found that the PCM is very effective in mitigrating the adverse effect of pulse heat loads. The six small PCM cylinders are more efficient than the large PCM

  19. Nonlinear ultrasonic imaging method for closed cracks using subtraction of responses at different external loads.

    Science.gov (United States)

    Ohara, Yoshikazu; Horinouchi, Satoshi; Hashimoto, Makoto; Shintaku, Yohei; Yamanaka, Kazushi

    2011-08-01

    To improve the selectivity of closed cracks for objects other than cracks in ultrasonic imaging, we propose an extension of a novel imaging method, namely, subharmonic phased array for crack evaluation (SPACE) as well as another approach using the subtraction of responses at different external loads. By applying external static or dynamic loads to closed cracks, the contact state in the cracks varies, resulting in an intensity change of responses at cracks. In contrast, objects other than cracks are independent of external load. Therefore, only cracks can be extracted by subtracting responses at different loads. In this study, we performed fundamental experiments on a closed fatigue crack formed in an aluminum alloy compact tension (CT) specimen using the proposed method. We examined the static load dependence of SPACE images and the dynamic load dependence of linear phased array (PA) images by simulating the external loads with a servohydraulic fatigue testing machine. By subtracting the images at different external loads, we show that this method is useful in extracting only the intensity change of responses related to closed cracks, while canceling the responses of objects other than cracks.

  20. The relationships between internal and external training load models during basketball training.

    Science.gov (United States)

    Scanlan, Aaron T; Wen, Neal; Tucker, Patrick S; Dalbo, Vincent J

    2014-09-01

    The present investigation described and compared the internal and external training loads during basketball training. Eight semiprofessional male basketball players (mean ± SD, age: 26.3 ± 6.7 years; stature: 188.1 ± 6.2 cm; body mass: 92.0 ± 13.8 kg) were monitored across a 7-week period during the preparatory phase of the annual training plan. A total of 44 total sessions were monitored. Player session ratings of perceived exertion (sRPE), heart rate, and accelerometer data were collected across each training session. Internal training load was determined using the sRPE, training impulse (TRIMP), and summated-heart-rate-zones (SHRZ) training load models. External training load was calculated using an established accelerometer algorithm. Pearson product-moment correlations with 95% confidence intervals (CIs) were used to determine the relationships between internal and external training load models. Significant moderate relationships were observed between external training load and the sRPE (r42 = 0.49, 95% CI = 0.23-0.69, p basketball settings. Basketball coaching and conditioning professionals should not assume a linear dose-response between accelerometer and internal training load models during training and are recommended to combine internal and external approaches when monitoring training load in players.

  1. External representation of argumentation in CSCL and the management of cognitive load

    NARCIS (Netherlands)

    Bruggen, J.M.; Kirschner, P.A.; Jochems, W.

    2002-01-01

    Computer-supported collaborative learning (CSCL) environments, particularly environments where students share external representations, are discussed as an interesting area for the application of cognitive load theory (CLT). CSCL environments share a number of characteristics that will induce consid

  2. The Effect of External Factors on Consumption Electricity Loads Forecasting using Fuzzy Takagi-Sugeno Kang

    National Research Council Canada - National Science Library

    Gayatri Dwi Santika; wayan f mahmudy

    2017-01-01

    .... The results of the study came to the conclusion that Fuzzy Inference System Sugeno method using external factors to forecast the consumption of electrical load gives a better result than Fuzzy...

  3. Integration and software for thermal test of heat rate sensors. [space shuttle external tank

    Science.gov (United States)

    Wojciechowski, C. J.; Shrider, K. R.

    1982-01-01

    A minicomputer controlled radiant test facility is described which was developed and calibrated in an effort to verify analytical thermal models of instrumentation islands installed aboard the space shuttle external tank to measure thermal flight parameters during ascent. Software was provided for the facility as well as for development tests on the SRB actuator tail stock. Additional testing was conducted with the test facility to determine the temperature and heat flux rate and loads required to effect a change of color in the ET tank external paint. This requirement resulted from the review of photographs taken of the ET at separation from the orbiter which showed that 75% of the external tank paint coating had not changed color from its original white color. The paint on the remaining 25% of the tank was either brown or black, indicating that it had degraded due to heating or that the spray on form insulation had receded in these areas. The operational capability of the facility as well as the various tests which were conducted and their results are discussed.

  4. Interaction of adhered metallic dust with transient plasma heat loads

    NARCIS (Netherlands)

    Ratynskaia, S.; Tolias, P.; I. Bykov,; Rudakov, D.; de Angeli, M.; Vignitchouk, L.; Ripamonti, D.; Riva, G.; Bardin, S.; van der Meiden, H.; Vernimmen, J.; Bystrov, K.; De Temmerman, G.

    2016-01-01

    The first study of the interaction of metallic dust (tungsten, aluminum) adhered on tungsten substrates with transient plasma heat loads is presented. Experiments were carried out in the Pilot-PSI linear device with transient heat fluxes up to 550 MW m −2 and in the DIII-D divertor tokamak. The cent

  5. 24 CFR 3280.508 - Heat loss, heat gain and cooling load calculations.

    Science.gov (United States)

    2010-04-01

    ... Thermal Protection § 3280.508 Heat loss, heat gain and cooling load calculations. (a) Information, values... Floor Systems 23.15Pipes 23.17Tanks, Vessels, and Equipment 23.18Refrigerated Rooms and Buildings 24... heat-flow paths (“thermal shorts”) shall be explicitly accounted for in the calculation of...

  6. Recovery of Myocardial Kinematic Function without the Time History of External Loads

    Directory of Open Access Journals (Sweden)

    Zhang Heye

    2010-01-01

    Full Text Available A time-domain filtering algorithm is proposed to recover myocardial kinematic function using output-only measurements without the time history of external loads. The main contribution of this work is that the overall effect of all the external loads on the myocardium is treated as a random variable disturbed by the Gaussian white noise because the external loads of the myocardium are usually unknown in practical exercises. The kernel of our proposed algorithm is an iterative, multiframe, and sequential filtering procedure consisting of a Kalman filter and a least-squares filter. In our proposed implementation, the initial guess of myocardial kinematic function and residual innovation of all the state variables are first computed using a Kalman filter via state space equations only driven by the Gaussian white noise, and then the residual innovation is fed into a least-squares filter to estimate the total external loads of the myocardium. In the end, the initial guess of myocardial kinematic function is corrected using external loads provided by the least-squares filter. After the introduction of the whole structure of our algorithm, we demonstrate the ability of the framework on synthetic data and MR image sequences.

  7. Space Heating Load Estimation Procedure for CHP Systems sizing

    Science.gov (United States)

    Vocale, P.; Pagliarini, G.; Rainieri, S.

    2015-11-01

    Due to its environmental and energy benefits, the Combined Heat and Power (CHP) represents certainly an important measure to improve energy efficiency of buildings. Since the energy performance of the CHP systems strongly depends on the fraction of the useful cogenerated heat (i.e. the cogenerated heat that is actually used to meet building thermal demand), in building applications of CHP, it is necessary to know the space heating and cooling loads profile to optimise the system efficiency. When the heating load profile is unknown or difficult to calculate with a sufficient accuracy, as may occur for existing buildings, it can be estimated from the cumulated energy uses by adopting the loads estimation procedure (h-LEP). With the aim to evaluate the useful fraction of the cogenerated heat for different operating conditions in terms of buildings characteristics, weather data and system capacity, the h-LEP is here implemented with a single climate variable: the hourly average dry- bulb temperature. The proposed procedure have been validated resorting to the TRNSYS simulation tool. The results, obtained by considering a building for hospital use, reveal that the useful fraction of the cogenerated heat can be estimated with an average accuracy of ± 3%, within the range of operative conditions considered in the present study.

  8. Short-term heat load forecasting for single family houses

    DEFF Research Database (Denmark)

    Bacher, Peder; Madsen, Henrik; Nielsen, Henrik Aalborg

    2013-01-01

    This paper presents a method for forecasting the load for space heating in a single-family house. The forecasting model is built using data from sixteen houses located in Sønderborg, Denmark, combined with local climate measurements and weather forecasts. Every hour the hourly heat load for each...... characteristics for each house, such as the level of adaptivity and the thermal dynamical response of the building, which is modeled with simple transfer functions. Identification of a model, which is suitable for all the houses, is carried out. The results show that the one-step ahead errors are close to white...

  9. Monitoring External and Internal Loads of Brazilian Soccer Referees During Official Matches

    Science.gov (United States)

    Costa, Eduardo C.; Vieira, Caio M. A.; Moreira, Alexandre; Ugrinowitsch, Carlos; Castagna, Carlo; Aoki, Marcelo S.

    2013-01-01

    This study aimed to assess the external and internal loads of Brazilian soccer referees during official matches. A total of 11 field referees (aged 36.2 ± 7.5 years) were monitored during 35 matches. The external (distance covered, mean and maximal speed) and internal load parameters (session ratings of perceived exertion [RPE] training load [TL], Edwards' TL, and time spent in different heart rate [HR] zones) were assessed in 3-4 matches per referee. External load parameters were measured using a wrist Global Positioning System (GPS) receiver. No differences in distance covered (5.219 ± 205 vs. 5.230 ± 237 m) and maximal speed (19.3 ± 1.0 vs. 19.4 ± 1.4 km·h-1) were observed between the halves of the matches (p > 0.05). However, the mean speed was higher in the first half of the matches (6.6 ± 0.4 vs. 6.4 ± 0.3 km·h-1) (p referees demonstrated a HR ≥ 80% of HRmax. Nonetheless, the time spent at 90-100% of HRmax was higher in the first half (59.9 vs. 52.3%) (p referees demonstrated high external and internal load demands during official matches. The portable GPS/HR monitors and session RPE method can provide relevant information regarding the magnitude of the physiological strain during official matches. Key Points High external and internal loads were imposed on Brazilian soccer referees during official matches. There was a high positive correlation between a subjective marker of internal load (session RPE) and parameters of external load (distance covered between 90-100% of HRmax and maximal speed). There was a high positive correlation between session RPE method and Edwards' method. Session RPE seems to be a reliable marker of internal load. The portable GPS/HR monitors and the session RPE method can provide relevant information regarding the magnitude of external and internal loads of soccer referees during official matches. PMID:24149165

  10. Effects of Lewis number on coupled heat and mass transfer in a circular tube subjected to external convective heating.

    Science.gov (United States)

    Jiao, Anjun; Zhang, Yuwen; Ma, Hongbin; Critser, John

    2009-03-01

    Heat and mass transfer in a circular tube subject to the boundary condition of the third kind is investigated. The closed form of temperature and concentration distributions, the local Nusselt number based on the total external heat transfer and convective heat transfer inside the tube, as well as the Sherwood number were obtained. The effects of Lewis number and Biot number on heat and mass transfer were investigated.

  11. Particle loading rates for HVAC filters, heat exchangers, and ducts.

    Science.gov (United States)

    Waring, M S; Siegel, J A

    2008-06-01

    The rate at which airborne particulate matter deposits onto heating, ventilation, and air-conditioning (HVAC) components is important from both indoor air quality (IAQ) and energy perspectives. This modeling study predicts size-resolved particle mass loading rates for residential and commercial filters, heat exchangers (i.e. coils), and supply and return ducts. A parametric analysis evaluated the impact of different outdoor particle distributions, indoor emission sources, HVAC airflows, filtration efficiencies, coils, and duct system complexities. The median predicted residential and commercial loading rates were 2.97 and 130 g/m(2) month for the filter loading rates, 0.756 and 4.35 g/m(2) month for the coil loading rates, 0.0051 and 1.00 g/month for the supply duct loading rates, and 0.262 g/month for the commercial return duct loading rates. Loading rates are more dependent on outdoor particle distributions, indoor sources, HVAC operation strategy, and filtration than other considered parameters. The results presented herein, once validated, can be used to estimate filter changing and coil cleaning schedules, energy implications of filter and coil loading, and IAQ impacts associated with deposited particles. The results in this paper suggest important factors that lead to particle deposition on HVAC components in residential and commercial buildings. This knowledge informs the development and comparison of control strategies to limit particle deposition. The predicted mass loading rates allow for the assessment of pressure drop and indoor air quality consequences that result from particle mass loading onto HVAC system components.

  12. External loading does not change energy cost and mechanics of rollerski skating.

    Science.gov (United States)

    Millet, G; Perrey, S; Candau, R; Belli, A; Borrani, F; Rouillon, J D

    1998-08-01

    The purpose of this study was to examine the effects of external loading on the energy cost and mechanics of roller ski skating. A group of 13 highly skilled male cross-country skiers roller skied at 19.0 ( SD 0.1) km x h(-1) without additional load and with loads of 6% and 12% body mass (mb). Oxygen uptake (VO2), knee and ankle joint kinematics, roller-ski electromyogram (EMG) of the vastus lateralis and gastrocnemius lateralis muscles, and roller ski velocity were recorded during the last 40 s of each 4-min period of roller skiing. One-way repeated measures ANOVA revealed that the VO2 expressed relative to total mass (mtot), joint kinetics, eccentric-to-concentric ratio of the integrated EMG, velocity changes within a cycle, and cycle rate did not change significantly with load. The subsequent analysis of the effect of load on each resistance opposing motion suggested that the power to sustain changes in translational kinetic energy, potential energy, and overcoming rolling resistance increased proportionately with the load. The lack of a significant change in VO2/mtot with external loading was associated with a lack of marked change in external mechanical power relative to mtot. The existence of an EMG signal during the eccentric phase prior to the thrust (concentric phase), as well as the lack of significant delay between the two phases, showed that a stretch-shortening cycle (SSC) occurs in roller ski skating. Taken together, the present results would suggest that external loading up to 12% mb does not increase storage and release of elastic energy of lower limb muscles during SSC in roller ski skating.

  13. Differences in lumbar spine load due to posture and upper limb external load.

    Science.gov (United States)

    Kamińska, Joanna; Roman-Liu, Danuta; Zagrajek, Tomasz; Borkowski, Paweł

    2010-01-01

    As the lumbar region of the spine is particularly predisposed to musculoskeletal disorders, the aim of this article was to assess lumbar spine load on the basis of an accurate model of this part of the body. The model was developed with the finite element method and the energy criterion for optimising muscle work. Computer calculations confirmed that stresses and compression forces in intervertebral discs increased with an increase in the load force and that they were significantly larger in the bent forwards posture than in the erect posture. This result clearly shows that lifting light objects and the erect posture are important elements in minimising spine load.

  14. Heat loads and cryogenics for HE-LHC

    CERN Document Server

    Delikaris, D

    2011-01-01

    We report preliminary considerations on cryogenics for a higher-energy LHC ("HE-LHC") with about 16.5 TeV beam energy and 20-T dipole magnets. In particular we sketch the heat loads scaled on the proposed principal beam parameters and size the cryogenic plants for different operating temperature of the beam screens.

  15. Cryogenic heat loads analysis from SST-1 plasma experiments

    Science.gov (United States)

    Bairagi, N.; Tanna, V. L.; Pradhan, S.

    2017-02-01

    Cryogenic heat load analysis is an important aspect for stable operation of Tokamaks employing large scale superconducting magnets. Steady State Superconducting Tokamak (SST-1) at IPR is equipped with superconducting magnets system (SCMS) comprising sixteen numbers of modified ‘D’ shaped toroidal field (TF) and nine poloidal field (PF) superconducting coils which are wound using NbTi/Cu based cable-in conduit conductor (CICC). SST-1 magnets operation has flexibility to cool either in two-phase with sub-cooling, two-phase without sub-cooling or single phase (supercritical) helium using a dedicated 1.3 kW helium refrigerator cum liquefier (HRL). Here, we report gross heat losses for integrated TF superconducting magnets of SST-1 during the plasma campaign using cryogenic helium supply/return thermodynamic data from cryoplant. Heat loads mainly comprising of steady state as well as transient loads are smoothly absorbed by SST-1 cryogenic helium plant during plasma experiments. The corresponding heat produced in the coils is totally released to the helium flowing through the TF coils, which in turn is dumped into liquid helium stored in main control Dewar. These results are very useful reference for heat loss analysis for TF as well as PF coils and provides database for future operation of SST-1 machine.

  16. Health Externalities and Heat savings in Energy System Modelling

    DEFF Research Database (Denmark)

    Zvingilaite, Erika

    from the rest of the energy system. This PhD study contributes to the development in energy system modelling, by including heat saving options – insulation of walls, roofs and floors, replacing of windows and installing ventilation system with heat recovery – in the Danish heat and power sector...... and included in an energy system optimisation model. The performed analysis of the Danish heat and power sector concludes that accounting for spatial variation of health damage costs in heat and power system optimisation model has an effect on the optimal technology mix and distribution of energy plants among...... and are popular as secondary heating technologies in Denmark, can cause indoor and outdoor air pollution locally. Hence, consumers can be exposed to their own air pollution, which can cause damage to their health. Such damage costs should be internalised in consumer decision making. The PhD study demonstrates...

  17. Design and Analysis of CH-47 External Cargo Handling System (Snubbed Load).

    Science.gov (United States)

    1979-10-01

    induced oscillation (potential for " vertical - bounce ") 48 QUANTITATIVE CONFIGURATION COMPARISON 7 CONFIGURATION 1 2 3 4 5 6 8 EVALUATION WT FAC CRITERIA ACFT...they were in early CH-47 aircraft because of incorporation of the ECP-41OR3 thrust control system which alleviates external load vertical bounce . The CH

  18. INVESTIGATION OF SOLAR ABSORPTANCE OF BUILDING EXTERNAL SURFACES FROM HEAT FLUX POINT OF VIEW

    Directory of Open Access Journals (Sweden)

    Meral ÖZEL

    2006-02-01

    Full Text Available In this study, solar absorptance of external surfaces of buildings has been numerically investigated from the heat gain and losses point of view. For this purpose, external surface solar absorptance was icreased from 0 to 1with an ratio of 0.1 and, for the summer and winter conditions, heat fluxs was calculated by considering orientations of the wall and its roof for brick and concrete structure materials. Besides, external surface absorptance was assumed as 0.2, 0.5 and 0.9, respectively. Than, heat gain and losses were calculated to insulation thickness increasing on the outdoor surface of wall. Results obtained were presented as graphics

  19. Direct and indirect loading of the Ilizarov external fixator: the effect on the interfragmentary movements and compressive loads.

    Science.gov (United States)

    Gessmann, Jan; Baecker, Hinnerk; Jettkant, Birger; Muhr, Gert; Seybold, Dominik

    2011-04-01

    The amount of weight bearing and the force transmission to the frame have an important influence on the results of treatment with an Ilizarov external fixator. The frame provides beneficial interfragmentary movements and compressive loads at the fracture site through elastic wires. Mobilisation can be achieved by applying a weight-bearing platform at the distal end of the fixator. The effect on the interfragmentary movements and the compressive loads in indirect and direct loading were analysed in this study using a composite tibia bone model. Displacement transducers were attached to measure the interfragmentary movements and to detect relative movements of the bone fragments and movements between the rings. The compressive loads in the osteotomy were measured with loading cells in the defect zone. The weight-bearing platform had a substantial effect on the biomechanical behaviour of the frame. It led to an indirect force transmission through the fixator with respect to the osteotomy, resulting in lower compressive loads, lower interfragmentary movements and higher mechanical stress on the frame.

  20. Liquid fueled external heating system for STM4-120 Stirling engine

    Science.gov (United States)

    Meijer, R. J.; Ziph, B.; Godett, T. M.

    1985-01-01

    The STM4-120 Stirling engine, currently under development at Stirling Thermal Motors, Inc., is a 40 kW variable stroke engine with indirect heating using a sodium heat pipe. The engine is functionally separated into an application independent Energy Conversion Unit (ECU) consisting of the Stirling cycle and drive heated by condensing sodium and the application dependent External Heating System (EHS), designed to supply the ECU with sodium vapor heated by the particular energy source, connected by tubes with mechanical couplings. This paper describes an External Heating System for the STM4-120 ECU designed for the combustion of liquid fuel, comprised of a recuperative preheater, a combustion chamber, and a heat exchanger/evaporator where heat is transferred from the flue gas to the sodium causing it to evaporate. The design concept and projected performance are described and discussed.

  1. Heat recovery improves part-load turbine sfc

    Energy Technology Data Exchange (ETDEWEB)

    Lester, J.W.; Ware, R.N.

    1982-12-01

    Explains how energy efficiencies can be held almost constant for full- and half-load operation of gas turbine powered mobile generators via heat recovery techniques. Two basic types of gas turbine heat recovery systems are considered: recuperative and regenerative. Effectiveness of a heat recovery device is usually defined as a ratio of the actual air-side temperature rise to the maximum theoretical temperature rise. This theoretical increase would raise the air temperature to that of the gasside temperature. A prototype was prepared, the only modification to the existing model GTP36-51 being incorporation of recuperator ducting and addition of the recuperator itself. The test program's goal was to demonstrate sfc reduction of the order of 40%. Results, corrected to a sea-level, 15C day, adequately demonstrated the improvement. A 36% reduction in fuel consumption at a 30-kW load, and a 32% reduction at a 15-kW load, were demonstrated. For further sfc reduction, increased operating temperatures are essential. Optimized pressure ratio was found to lie between four and five to one. An engine rotor speed of 112,000 rpm was found necessary for the high-temperature component match. Concludes that heat recovery, together with the higher component efficiencies projected for 1983 and beyond, is expected to permit an sfc of the order of 190 g/kWh for devices of the types described.

  2. Dynamic Loading of Carrara Marble in a Heated State

    Science.gov (United States)

    Wong, Louis Ngai Yuen; Li, Zhihuan; Kang, Hyeong Min; Teh, Cee Ing

    2017-06-01

    Useable land is a finite space, and with a growing global population, countries have been exploring the use of underground space as a strategic resource to sustain the growth of their society and economy. However, the effects of impact loading on rocks that have been heated, and hence the integrity of the underground structure, are still not fully understood and has not been included in current design standards. Such scenarios include traffic accidents and explosions during an underground fire. This study aims to provide a better understanding of the dynamic load capacity of Carrara marble at elevated temperatures. Dynamic uniaxial compression tests are performed on Carrara marble held at various temperatures using a split-Hopkinson Pressure Bar (SHPB) setup with varying input force. A customized oven is included in the SHPB setup to allow for testing of the marble specimens in a heated state. After the loading test, a three-wave analysis is performed to obtain the dynamic stress-strain curve of the specimen under loading. The fragments of the failed specimens were also collected and dry-sieved to obtain the particle size distribution. The results reveal that the peak stress of specimens that have been heated is negatively correlated with the heating temperature. However, the energy absorbed by the specimens at peak stress at all temperatures is similar, indicating that a significant amount of energy is dissipated via plastic deformation. Generally, fragment size is also found to show a negative correlation with heating temperature and loading pressure. However, in some cases this relationship does not hold true, probably due to the occurrence of stress shadowing. Linear Elastic Fracture Mechanics has been found to be generally applicable to specimens tested at low temperatures; but at higher temperatures, Elastic-Plastic Fracture Mechanics will give a more accurate prediction. Another contribution of this study is to show that other than the peak stress of the

  3. Surface heat loads on the ITER divertor vertical targets

    Science.gov (United States)

    Gunn, J. P.; Carpentier-Chouchana, S.; Escourbiac, F.; Hirai, T.; Panayotis, S.; Pitts, R. A.; Corre, Y.; Dejarnac, R.; Firdaouss, M.; Kočan, M.; Komm, M.; Kukushkin, A.; Languille, P.; Missirlian, M.; Zhao, W.; Zhong, G.

    2017-04-01

    The heating of tungsten monoblocks at the ITER divertor vertical targets is calculated using the heat flux predicted by three-dimensional ion orbit modelling. The monoblocks are beveled to a depth of 0.5 mm in the toroidal direction to provide magnetic shadowing of the poloidal leading edges within the range of specified assembly tolerances, but this increases the magnetic field incidence angle resulting in a reduction of toroidal wetted fraction and concentration of the local heat flux to the unshadowed surfaces. This shaping solution successfully protects the leading edges from inter-ELM heat loads, but at the expense of (1) temperatures on the main loaded surface that could exceed the tungsten recrystallization temperature in the nominal partially detached regime, and (2) melting and loss of margin against critical heat flux during transient loss of detachment control. During ELMs, the risk of monoblock edge melting is found to be greater than the risk of full surface melting on the plasma-wetted zone. Full surface and edge melting will be triggered by uncontrolled ELMs in the burning plasma phase of ITER operation if current models of the likely ELM ion impact energies at the divertor targets are correct. During uncontrolled ELMs in pre-nuclear deuterium or helium plasmas at half the nominal plasma current and magnetic field, full surface melting should be avoided, but edge melting is predicted.

  4. Assessment of external fixator reusability using load- and cycle-dependent tests.

    Science.gov (United States)

    Matsuura, Maiko; Lounici, Smain; Inoue, Nozomu; Walulik, Stephen; Chao, Edmund Y S

    2003-01-01

    No standard method has been established for investigating repeated use of an external fixator. The purpose of the current study was to establish a fatigue testing method for assessing fixator frame reuse. A unilateral DynaFix trade mark external fixator system was tested using high-load and low-cycle (900-150 N at 5 Hz) and low-load and high-cycle (450-100 N at 10 Hz) tests (assumed one use of 500,000 and 1 million cycles, respectively). These loading conditions were selected to simulate single clinical use and to satisfy Food and Drug Administration requirements. In the high-load low-cycle test, substantial failure of the serrated joint occurred before completion of the first simulated use. In the low-load high-cycle test, all fixators completed three simulated clinical uses without failure, although (1/4) of the serrated joint components had hairline cracks. The high-load low-cycle test identified the fixator components which should be examined and replaced if reuse of the fixator is to be considered. Wear and deformation of the set screw on the rotary joint and telescoping mechanisms were observed in the low-load high-cycle test but not in the high-load low-cycle test. Therefore, if the unilateral DynaFix trade mark fixators are being considered for reusability, the number of reuses should be limited as the whole structure of the device will experience fatigue damage as the loading cycle increases.

  5. Heat Conductivity of One-Dimensional Carbon Chain in an External Potential

    Institute of Scientific and Technical Information of China (English)

    GE Yong; DONG Jin-Ming

    2007-01-01

    The heat transport in a one-dimensional (1D) carbon nanowire (CNW) lying in an external potential with different amplitudes and periods is studied by the non-equilibrium molecular dynamics method. It is found that the thermal conductivity of CNW is always anomalous, increasing with the CNW length and obeying the power law κ~ N, in which α decreases with the increasing external potential amplitude. The thermal conductivity could be enhanced by the external potential with rather larger amplitudes, which means that an applied external potential could be an efficient tool to improve the heat conductivity of a real 1D material. In addition, the effect of different periods of the external potential is studied, finding the external potential with an incommensurate period leads to the smaller α value.

  6. MONITORING EXTERNAL AND INTERNAL LOADS OF BRAZILIAN SOCCER REFEREES DURING OFFICIAL MATCHES

    Directory of Open Access Journals (Sweden)

    Eduardo C. Costa

    2013-09-01

    Full Text Available This study aimed to assess the external and internal loads of Brazilian soccer referees during official matches. A total of 11 field referees (aged 36.2 ± 7.5 years were monitored during 35 matches. The external (distance covered, mean and maximal speed and internal load parameters (session ratings of perceived exertion [RPE] training load [TL], Edwards' TL, and time spent in different heart rate [HR] zones were assessed in 3-4 matches per referee. External load parameters were measured using a wrist Global Positioning System (GPS receiver. No differences in distance covered (5.219 ± 205 vs. 5.230 ± 237 m and maximal speed (19.3 ± 1.0 vs. 19.4 ± 1.4 km·h-1 were observed between the halves of the matches (p > 0.05. However, the mean speed was higher in the first half of the matches (6.6 ± 0.4 vs. 6.4 ± 0.3 km·h-1 (p 80% of HRmax. Nonetheless, the time spent at 90-100% of HRmax was higher in the first half (59.9 vs. 52.3% (p < 0.05. Significant correlations between session RPE TL and distance covered at 90-100% of HRmax (r = 0.62 and session RPE TL and maximal speed (r = 0.54 (p < 0.05 were noted. Furthermore, there was a positive correlation between session RPE TL and Edwards' TL (r = 0.61 (p < 0.05. Brazilian soccer referees demonstrated high external and internal load demands during official matches. The portable GPS/HR monitors and session RPE method can provide relevant information regarding the magnitude of the physiological strain during official matches

  7. High Heat-Load Slits for the PLS Multipole Wiggler

    CERN Document Server

    Gil, Kyehwan; Kim, Young-Chan; Lee, Heung-Soo; Wha Chung, Chin

    2005-01-01

    The HFMX (High Flux Macromolecular X-ray crystallography) beamline under commissioning at Pohang Accelerator Laboratory uses beam from a multipole wiggler for MAD experiment. Two horizontal and vertical slits relevant to high heat load are installed at its front-end. In order to treat high heat load and to reduce beam scattering, the horizontal slit has two glidcop blocks with 10° of vertical inclination and its tungsten blades defining beam size are bolted on backsides of both blocks. The blocks of the slit are adjusted on fixed slides by two actuating bars, respectively. Water through channels machined along the actuating bars cool down the heat load of both blocks. The vertical slit has the same structure as the horizontal slit except its installation direction and angle of vertical inclination. The installed slits show stable operation performance and no alignment for the blocks is required by virtue of a pair of blocks translating on slides. The cooling performance of two slits is also shown to ...

  8. EXACT SOLUTION OF AN EXTERNAL CIRCULAR CRACK IN A PIEZOELECTRIC SOLID SUBJECTED TO SHEAR LOADING

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A three-dimensional, exact analysis is presented in this paperfor the problem of an external circular crack in a transversely isotropic piezoelectric medium subjected to arbitrary antisymmetric shear loading. A recently proposed general solution of three-dimensional piezoelectricity is employed. It is shown that four quasi harmonic functions involved in the general solution can be represented by just one complex potential. Previous results in potential theory are then used to obtain the exact solution of the problem. For point shear loading, Green's functions for the elastoelectric field are derived in terms of elementary functions.

  9. On the addition of heat to solar pond from external sources

    NARCIS (Netherlands)

    Ganguly, S.; Jain, Ravi; Date, Abhijit; Akbarzadeh, Aliakbar

    2017-01-01

    This brief note addresses the method of adding heat to a solar pond from an external source which is used to enhance the performance of a solar pond. Heat energy collected by Evacuated Tube Solar Collectors (ETSC) is transferred by circulating fluid from the Lower Convective Zone (LCZ) of a solar po

  10. On the addition of heat to solar pond from external sources

    NARCIS (Netherlands)

    Ganguly, S.; Jain, Ravi; Date, Abhijit; Akbarzadeh, Aliakbar

    2017-01-01

    This brief note addresses the method of adding heat to a solar pond from an external source which is used to enhance the performance of a solar pond. Heat energy collected by Evacuated Tube Solar Collectors (ETSC) is transferred by circulating fluid from the Lower Convective Zone (LCZ) of a solar

  11. Unified solution of limit loads of thick wall cylinder subject to external pressure considering strain softening

    Institute of Scientific and Technical Information of China (English)

    CHEN Changfu; XIAO Shujun; YANG Yu

    2007-01-01

    Based on the unified strength theory [1],a unified strength criterion for strain softening materials,such as concrete or rock,was derived,and the elastic and plastic limit loads of a thick-walled cylinder made of these materials subject to external pressure were also given.In addition,the influence of some factors on the limit loads of such cylinders as the ratio of the external radius to intemal radius,rb/ra,the coefficient b,which reflects the effect of medium principal stress and the normal stress of the relevant surface on the material destroy degree,the ratio of tensile strength to compressed strength of the material,α,and the damage variable β were discussed in detail.Some examples were given and some meaningful results were obtained.

  12. Beam heat load investigations with a cold vacuum chamber for diagnostics in a synchrotron light source

    Energy Technology Data Exchange (ETDEWEB)

    Voutta, Robert

    2016-04-22

    The beam heat load is a crucial input parameter for the cryogenic design of superconducting insertion devices. To understand the discrepancies between the predicted heat load of an electron beam to a cold bore and the heat load observed in superconducting devices, a cold vacuum chamber for diagnostics has been built. Extensive beam heat load measurements were performed at the Diamond light source. They are analysed systematically and combined with complementary impedance bench measurements.

  13. Beam heat load investigations with a cold vacuum chamber for diagnostics in a synchrotron light source

    OpenAIRE

    Voutta, Robert

    2016-01-01

    The beam heat load is a crucial input parameter for the cryogenic design of superconducting insertion devices. To understand the discrepancies between the predicted heat load of an electron beam to a cold bore and the heat load observed in superconducting devices, a cold vacuum chamber for diagnostics has been built. Extensive beam heat load measurements were performed at the Diamond light source. They are analysed systematically and combined with complementary impedance bench measurements.

  14. Navier-Stokes analysis of turbomachinery blade external heat transfer

    Science.gov (United States)

    Ameri, A. A.; Sockol, P. M.; Gorla, R. S. R.

    1992-01-01

    The two-dimensional, compressible, thin-layer Navier-Stokes and energy equations were solved numerically to obtain heat transfer rates on turbomachinery blades. The Baldwin-Lomax algebraic model and the q - omega low Reynolds number, two-equation model were used for modeling of turbulence. For the numerical solution of the governing equations a four-stage Runge-Kutta solver was employed. The turbulence model equations were solved using an implicit scheme. Numerical solutions are presented for two-dimensional flow within two vane cascades. The heat transfer results and the pressure distributions were compared with published experimental data. The agreement between the numerical calculations and the experimental values were found to be generally favorable. The position of transition from laminar to turbulent flow was also predicted accurately.

  15. Convective Heat Transfer Between the Wall Surface of a Cavity and the External Main Stream

    Science.gov (United States)

    Yoshiwara, Masahiro; Katto, Yoshiro; Yokoyama, Masanori

    An experimental study has been made under the following conditions for convective heat transfer between the wall surface of a cavity of which both width and depth are 25 mm and the external main stream; the range of Reynolds numbers is from 104 to 105, and the ratio of tripping wire diameter to cavity width is 0.08. The oncoming boundary layer to a cavity is turbulent by the tripping wire with the existing study. Convective heat transfer between a cavity wall surface and the external main stream is treated by the following two phenomena; one is the heat transfer which is related to the temperature difference between the wall surface and the fluid in the cavity, and the other the heat transfer which is related to the temperature difference between the fluid in a cavity and the external mainstream. Experimental data obtained for the foregoing conditions is almost coincide with the existing dimensionless correlations of two of the authors.

  16. Life cycle assessment of base-load heat sources for district heating system options

    Energy Technology Data Exchange (ETDEWEB)

    Ghafghazi, Saeed [University of British Columbia, Vancouver; Sowlati, T. [University of British Columbia, Vancouver; Sokhansanj, Shahabaddine [ORNL; Melin, Staffan [Delta Research Corporation

    2011-03-01

    Purpose There has been an increased interest in utilizing renewable energy sources in district heating systems. District heating systems are centralized systems that provide heat for residential and commercial buildings in a community. While various renewable and conventional energy sources can be used in such systems, many stakeholders are interested in choosing the feasible option with the least environmental impacts. This paper evaluates and compares environmental burdens of alternative energy source options for the base load of a district heating center in Vancouver, British Columbia (BC) using the life cycle assessment method. The considered energy sources include natural gas, wood pellet, sewer heat, and ground heat. Methods The life cycle stages considered in the LCA model cover all stages from fuel production, fuel transmission/transportation, construction, operation, and finally demolition of the district heating system. The impact categories were analyzed based on the IMPACT 2002+ method. Results and discussion On a life-cycle basis, the global warming effect of renewable energy options were at least 200 kgeqCO2 less than that of the natural gas option per MWh of heat produced by the base load system. It was concluded that less than 25% of the upstream global warming impact associated with the wood pellet energy source option was due to transportation activities and about 50% of that was resulted from wood pellet production processes. In comparison with other energy options, the wood pellets option has higher impacts on respiratory of inorganics, terrestrial ecotoxicity, acidification, and nutrification categories. Among renewable options, the global warming impact of heat pump options in the studied case in Vancouver, BC, were lower than the wood pellet option due to BC's low carbon electricity generation profile. Ozone layer depletion and mineral extraction were the highest for the heat pump options due to extensive construction required for these

  17. A Geometrically Exact Model for Externally Loaded Concentric-Tube Continuum Robots

    Science.gov (United States)

    Rucker, D. Caleb; Jones, Bryan A.; Webster, Robert J.

    2011-01-01

    Continuum robots, which are composed of multiple concentric, precurved elastic tubes, can provide dexterity at diameters equivalent to standard surgical needles. Recent mechanics-based models of these “active cannulas” are able to accurately describe the curve of the robot in free space, given the preformed tube curves and the linear and angular positions of the tube bases. However, in practical applications, where the active cannula must interact with its environment or apply controlled forces, a model that accounts for deformation under external loading is required. In this paper, we apply geometrically exact rod theory to produce a forward kinematic model that accurately describes large deflections due to a general collection of externally applied point and/or distributed wrench loads. This model accommodates arbitrarily many tubes, with each having a general preshaped curve. It also describes the independent torsional deformation of the individual tubes. Experimental results are provided for both point and distributed loads. Average tip error under load was 2.91 mm (1.5%–3% of total robot length), which is similar to the accuracy of existing free-space models. PMID:21566688

  18. Workshop on high heat load x-ray optics

    Energy Technology Data Exchange (ETDEWEB)

    1990-01-01

    A workshop on High Heat Load X-Ray Optics'' was held at Argonne National Laboratory on August 3--5, 1989. The object of this workshop was to discuss recent advances in the art of cooling x-ray optics subject to high heat loads from synchrotron beams. The cooling of the first optical element in the intense photon beams that will be produced in the next generation of synchrotron sources is recognized as one of the major challenges that must be faced before one will be able to use these very intense beams in future synchrotron experiments. Considerable advances have been made in this art during the last few years, but much work remains to be done before the heating problem can be said to be completely solved. Special emphasis was placed on recent cooling experiments and detailed finite element'' and finite difference'' calculations comparing experiment with theory and extending theory to optimize performance.

  19. Covering of heating load of object by using ground heat as a renewable energy source

    Directory of Open Access Journals (Sweden)

    Čenejac Aleksandra R.

    2012-01-01

    Full Text Available Rational use of energy, improving energy performance of buildings and use of renewable energy sources are the most important measures for reducing consumption of non-renewable primary energy (solid, liquid, and gaseous fuels, environmental protection and for the future sustainable development of mankind. In the total primary energy consumption great part is related to building industry, for heating spaces in which people stay and live. Renewable energy sources (RES present natural resources and they are one of the alternatives that allow obtaining heat for heating buildings, and by that they provide a significant contribution to the energy balance of a country. This paper analyzes the participation of ground source as RES, when the vertical (the probe in the ground and horizontal (registry in the ground heat exchangers are used for covering heating load of the building.

  20. External heating of electrical cables and auto-ignition investigation.

    Science.gov (United States)

    Courty, L; Garo, J P

    2017-01-05

    Electric cables are now extensively used for both residential and industrial applications. During more than twenty years, multi-scale approaches have been developed to study fire behavior of such cables that represents a serious challenge. Cables are rather complicated materials because they consist of an insulated part and jacket of polymeric materials. These polymeric materials can have various chemical structures, thicknesses and additives and generally have a char-forming tendency when exposed to heat source. In this work, two test methods are used for the characterization of cable pyrolysis and flammability. The first one permits the investigation of cable pyrolysis. A description of the cable mass loss is obtained, coupling an Arrhenius expression with a 1D thermal model of cables heating. Numerical results are successfully compared with experimental data obtained for two types of cable commonly used in French nuclear power plants. The second one is devoted to ignition investigations (spontaneous or piloted) of these cables. All these basic observations, measurements and modelling efforts are of major interest for a more comprehensive fire resistance evaluation of electric cables. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. Modeling and Simulation of Heat Transfer in Loaded Continuous Heat Treatment Furnace

    Institute of Scientific and Technical Information of China (English)

    KANG Jin-wu; HUANG Tian-you; PURUSHOTHAMAN Radhakrishnan; WANG Wei-wei; RONG Yi-ming

    2004-01-01

    Continuous furnaces are widely used in the heat treatment of mass-produced parts. However, the heating up process of parts in continuous furnace is still decided by experience. In this paper the heat transfer in the continuous furnace is formulated firstly. The heat balance in each zone is discussed and equations are given. Coupled with the model for heat transfer between workpieces and furnace and the heat transfer in the workload as well presented in the former developed CHT-bf for batch furnaces, a program CHT-cf for continuous furnaces was developed. The model deals with two typical movements of parts: continuous or step by step. The moving speed of parts and load pattern can be optimized based on the calculated temperature distributions and curves, especially, the fastest heated and slowest-heated temperature-distance profiles. A case study is carried out for the heat treatment of a kind of hook-shaped part. The calculated results are analyzed and in good agreement with the measured ones.

  2. Optimization of Boiler Heat Load in Water-Heating Boiler-House

    Directory of Open Access Journals (Sweden)

    B. A. Bayrashevsky

    2009-01-01

    Full Text Available An analytical method for optimization of water-heating boiler loads has been developed on the basis of approximated semi-empirical dependences pertaining to changes of boiler gross efficiency due to its load. A complex (∂tух/∂ξΔξ is determined on the basis of a systematic analysis (monitoring of experimental data and the Y. P. Pecker’s formula for calculation of balance losses q2. This complex makes it possible to set a corresponding correction to a standard value of the boiler gross efficiency due to contamination of heating surfaces.Software means for optimization of water-heating boilers has been developed and it is recommended to be applied under operational conditions.

  3. Series load induction heating inverter state estimator using Kalman filter

    Directory of Open Access Journals (Sweden)

    Szelitzky T.

    2011-12-01

    Full Text Available LQR and H2 controllers require access to the states of the controlled system. The method based on description function with Fourier series results in a model with immeasurable states. For this reason, we proposed a Kalman filter based state estimator, which not only filters the input signals, but also computes the unobservable states of the system. The algorithm of the filter was implemented in LabVIEW v8.6 and tested on recorded data obtained from a 10-40 kHz series load frequency controlled induction heating inverter.

  4. Heat conduction in a confined solid strip: response to external strain.

    Science.gov (United States)

    Chaudhuri, Debasish; Dhar, Abhishek

    2006-07-01

    We study heat conduction in a system of hard disks confined to a narrow two-dimensional channel. The system is initially in a high-density solidlike phase. We study, through nonequilibrium molecular dynamics simulations, the dependence of the heat current on an externally applied elongational strain. The strain leads to deformation and failure of the solid and we find that the changes in internal structure can lead to very sharp changes in the heat current. A simple free-volume-type calculation of the heat current in a finite hard-disk system is proposed. This reproduces some qualitative features of the current-strain graph for small strains.

  5. Directed motion generated by heat bath nonlinearly driven by external noise

    Energy Technology Data Exchange (ETDEWEB)

    Chaudhuri, J Ray [Department of Physics, Katwa College, Katwa, Burdwan 713 130, West Bengal (India); Barik, D [Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700 032 (India); Banik, S K [Department of Physics, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061-0435 (United States)

    2007-12-07

    Based on the heat bath system approach where the bath is nonlinearly modulated by an external Gaussian random force, we propose a new microscopic model to study directed motion in the overdamped limit for a nonequilibrium open system. Making use of the coupling between the heat bath and the external modulation as a small perturbation, we construct a Langevin equation with multiplicative noise- and space-dependent dissipation and the corresponding Fokker-Planck-Smoluchowski equation in the overdamped limit. We examine the thermodynamic consistency condition and explore the possibility of observing a phase-induced current as a consequence of state-dependent diffusion and, necessarily, nonlinear driving of the heat bath by the external noise.

  6. High Heat Load Properties of Ultra Fine Grain Tungsten

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Z.; Du, J.; Ge, C. [Lab. of Special Ceramic and P/M, University of Science and Technology, 100083 Beijing (China); Linke, J.; Pintsuk, G. [FZJ-Forschungszentrum Juelich GmbH, Association Euratom-FZJ, Institut fur Plasmaphysik, Postfach 1913, D-52425 Juelich (Germany); Song, S.X. [Research Center on Fusion Materials (RCFM), University of Science and Technology Beijing (USTB), 100083 Beijing (China)

    2007-07-01

    Full text of publication follows: Tungsten is increasingly considered as a promising candidate armour materials facing the plasma in tokamaks for medium to high heat flux components (EAST, ASDEX, ITER). Fabrication tungsten with ultra fine grain size is considered as an effective way to ameliorate some disadvantages of tungsten, such as its brittleness at room temperature. But the research data on the performance of ultra fine grain tungsten is still very limit. In this work, high heat load properties of pure ultra-fine grain tungsten have been studied. The ultra fine grain tungsten samples with average grain size of 0.2 {mu}m, 1 {mu}m and 3 {mu}m were fabricated by resistance sintering under ultra high pressure. The annealing experiments for the investigation of the material resistance against grain growth have been done by annealing samples in a vacuum furnace at different temperature holding for 2 hours respectively. It is found that recrystallization and grain growth occur at heating temperature of 1250 deg. c. The finer the initial grain sizes of tungsten, the smaller its grain growth grain. The effects of transient high thermal loads (off normal events like disruptions) on tungsten surface morphology have been performed in electron beam test facility JUDITH. The thermal loads tests have been carried out with 4 ms pulses at different power density of 0.22, 0.33, 0.44, 0.55 and 0.88 GW/m{sup 2} respectively. Horizontal cracks formed for all tungsten samples at 0.44 GW/m{sup 2}. Particle erosions occurred for tungsten with 3 {mu}m size at 0.33 GW/m{sup 2} and for tungsten with 0.2 and 1 {mu}m size at 0.55 GW/m{sup 2}. The weight loss of tungsten with 0.2, 1 and 3 {mu}m size are 2,0.1,0.6 mg respectively at 0.88 GW/m{sup 2}. The effects of a large number of very short transient repetitive thermal loads (ELM-like) on tungsten surface morphology also have been performed by using a fundamental wave of a YAG laser. It is found that tungsten with 0.2 {mu}m size has

  7. Factors related to external loads in buried pipelines; Consideracoes quanto as variaveis relacionadas ao carregamento externo em dutos enterrados

    Energy Technology Data Exchange (ETDEWEB)

    Provenzano, Carlos E.C.; Silva, Breno S.; Fernandes, Lincoln F.; Santos Junior, Sergio J.F. [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil); Louzada, Carlos H.C.M.

    2005-07-01

    Work of heavy equipment or vehicles above existent right-of-ways, may cause undesired external overload at buried pipelines in operation. The effect of these loads shall be analyzed considering the deflections and stresses on the pipelines. The major variables, nominal diameter, thickness, material, soil parameters, operation pressure and external loads shall be related and verified according to the limits from original project. Cases when the external loads cause higher efforts, the traffic over the pipelines shall be restricted in order to avoid damages. In other cases, it may be adapted to any technical alternatives to modify the parameters in such a way to make possible work above the right-of-way, such as increase the machine support area, increase backfill covering, a reduction in the internal operation pressure in a short time, etc. This work presents the study on the parameters used to establish the maximum allowable external loads over buried pipelines in operation. (author)

  8. External Load Affects Ground Reaction Force Parameters Non-uniformly during Running in Weightlessness

    Science.gov (United States)

    DeWitt, John; Schaffner, Grant; Laughlin, Mitzi; Loehr, James; Hagan, R. Donald

    2004-01-01

    Long-term exposure to microgravity induces detrimefits to the musculcskdetal system (Schneider et al., 1995; LeBlanc et al., 2000). Treadmill exercise is used onboard the International Space Station as an exercise countermeasure to musculoskeletal deconditioning due to spaceflight. During locomotive exercise in weightlessness (0G), crewmembers wear a harness attached to an external loading mechanism (EL). The EL pulls the crewmember toward the treadmill, and provides resistive load during the impact and propulsive phases of gait. The resulting forces may be important in stimulating bone maintenance (Turner, 1998). The EL can be applied via a bungee and carabineer clip configuration attached to the harness and can be manipulated to create varying amounts of load levels during exercise. Ground-based research performed using a vertically mounted treadmill found that peak ground reaction forces (GRF) during running at an EL of less than one body weight (BW) are less than those that occur during running in normal gravity (1G) (Davis et al., 1996). However, it is not known how the GRF are affected by the EL in a true OG environment. Locomotion while suspended may result in biomechanics that differ from free running. The purpose of this investigation was to determine how EL affects peak impact force, peak propulsive force, loading rate, and impulse of the GRF during running in 0G. It was hypothesized that increasing EL would result in increases in each GRF parameter.

  9. The impact of cognitive control, incentives, and working memory load on the P3 responses of externalizing prisoners.

    Science.gov (United States)

    Baskin-Sommers, Arielle R; Krusemark, Elizabeth A; Curtin, John J; Lee, Christopher; Vujnovich, Aleice; Newman, Joseph P

    2014-02-01

    The P3 amplitude reduction is one of the most common correlates of externalizing. However, few studies have used experimental manipulations designed to challenge different cognitive functions in order to clarify the processes that impact this reduction. To examine factors moderating P3 amplitude in trait externalizing, we administered an n-back task that manipulated cognitive control demands, working memory load, and incentives to a sample of male offenders. Offenders with high trait externalizing scores did not display a global reduction in P3 amplitude. Rather, the negative association between trait externalizing and P3 amplitude was specific to trials involving inhibition of a dominant response during infrequent stimuli, in the context of low working memory load, and incentives for performance. In addition, we discuss the potential implications of these findings for externalizing-related psychopathologies. The results complement and expand previous work on the process-level dysfunction contributing to externalizing-related deficits in P3.

  10. Integrated Behavior of Carbon and Copper Alloy Heat Sink Under Different Heat Loads and Cooling Conditions

    Institute of Scientific and Technical Information of China (English)

    Li Hua; Li Jiangang; Chen Junling; Hu Jiansheng

    2005-01-01

    An actively water-cooled limiter has been designed for the long pulse operation of an HT-7 device, by adopting an integrated structure-doped graphite and a copper alloy heat sink with a super carbon sheet serving as a compliant layer between them. The behaviors of the integrated structure were evaluated in an electron beam facility under different heat loads and cooling conditions. The surface temperature and bulk temperature distribution were carefully measured by optical pyrometers and thermocouples under a steady state heat flux of 1 to 5 MW/m2 and a water flow rate of 3 m3/h, 4.5 m3/h and 6 m3/h, respectively. It was found that the surface temperature increased rapidly with the heat flux rising, but decreased only slightly with the water flow rate rising. The surface temperature reached approximately 1200℃ at 5 MW/m2 of heat flux and 6 ms/h of water flow. The primary experimental results indicate that the integrated design meets the requirements for the heat expelling capacity of the HT-7 device. A set of numerical simulations was also completed, whose outcome was in good accord with the experimental results.

  11. An analysis of representative heating load lines for residential HSPF ratings

    Energy Technology Data Exchange (ETDEWEB)

    Rice, C. Keith [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Shen, Bo [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Shrestha, Som S. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-07-01

    This report describes an analysis to investigate representative heating loads for single-family detached homes using current EnergyPlus simulations (DOE 2014a). Hourly delivered load results are used to determine binned load lines using US Department of Energy (DOE) residential prototype building models (DOE 2014b) developed by Pacific Northwest National Laboratory (PNNL). The selected residential single-family prototype buildings are based on the 2006 International Energy Conservation Code (IECC 2006) in the DOE climate regions. The resulting load lines are compared with the American National Standards Institute (ANSI)/Air-Conditioning, Heating, and Refrigeration Institute (AHRI) Standard 210/240 (AHRI 2008) minimum and maximum design heating requirement (DHR) load lines of the heating seasonal performance factor (HSPF) ratings procedure for each region. The results indicate that a heating load line closer to the maximum DHR load line, and with a lower zero load ambient temperature, is more representative of heating loads predicted for EnergyPlus prototype residential buildings than the minimum DHR load line presently used to determine HSPF ratings. An alternative heating load line equation was developed and compared to binned load lines obtained from the EnergyPlus simulation results. The effect on HSPF of the alternative heating load line was evaluated for single-speed and two-capacity heat pumps, and an average HSPF reduction of 16% was found. The alternative heating load line relationship is tied to the rated cooling capacity of the heat pump based on EnergyPlus autosizing, which is more representative of the house load characteristics than the rated heating capacity. The alternative heating load line equation was found to be independent of climate for the six DOE climate regions investigated, provided an adjustable zero load ambient temperature is used. For Region IV, the default DOE climate region used for HSPF ratings, the higher load line results in an ~28

  12. Study on heat under dynamic loading of rubber

    Directory of Open Access Journals (Sweden)

    T. I. Igumenova

    2016-01-01

    Full Text Available A number of studies on heat buildup in tire rubber surface scan method samples using a thermal imaging camera. Investigated the exothermic chemical reaction mechanical destruction rubber when loading designs permanent cyclic stretching with deformation of the working zone 50%. Percentage of deformation of the working zone was chosen on the basis of the actual data on the stretch-compression zone "Rusk" tires, which is the maximum level difference of deformation during run-in. Experiment plan provided for periodic relaxation samples of at least 72 hours for more accurate simulation of operation process of structural products. Created and processed data on temperature changes in samples for bar and line profile for rubber compounds with the introduction of nanomodificator (fullerene-containing technical carbon in comparison with the control sample without him. The data obtained reflect the nature of heat depending on the composition of the compound. Identified common patterns of thermal nature of physicochemical process mechanical destruction rubbers. For rubber with nanomodifikatorom there has been an increase in the temperature interval reaction from a minimum to a maximum 2 degrees that is also linked to the rise in the average temperature of the reaction on the histogram also at 2-3 degrees of deformation under the same conditions and the level of cyclic loading. However, the temperature in the control sample that is associated with the beginning of the formation of hardened rubber structures, economies of Mallinza-Petrikeeva, occurs with delay twice compared with modified Fullerenes. Measurement of physic-mechanical indicators selected in the course of testing of samples showed the beginning of formation of structure with increased strength of samples in the sample temperature zone that corresponds to the thermal effect of èndotermičeskomu recombination reactions of macromolecules.

  13. CFD Analysis of Convective Heat Transfer Coefficient on External Surfaces of Buildings

    Directory of Open Access Journals (Sweden)

    Andrea de Lieto Vollaro

    2015-07-01

    Full Text Available Convective heat transfer coefficients for external building surfaces are essential in building energy simulation (BES to calculate convective heat gains and losses from building facades and roofs to the environment. These coefficients are complex functions of: building geometry, building surroundings, local air flow patterns and temperature differences. A microclimatic analysis in a typical urban configuration, has been carried out using Ansys Fluent Version 14.0, an urban street canyon, with a given H/W ratio, has been considered to simulate a three-dimensional flow field and to calculate the thermal fluid dynamics parameters that characterize the street canyon. In this paper, the convective heat transfer coefficient values on the windward external façade of the canyon and on the windward and leeward inner walls are analyzed and a comparison with values from experimental and numerical correlations is carried out.

  14. External Corrosion of Pipes in District Heating Systems; Utvaendig korrosion paa fjaerrvaermeroer

    Energy Technology Data Exchange (ETDEWEB)

    Sund, Goeran [Det Norske Veritas, Stockholm (Sweden)

    2002-07-01

    Corrosion damages of pipes in district heating systems can occur both external and internal. The aim with this work has been to clarify external corrosion damages of pipes, and try to correlate the damages to the corrosivity of different soils and waters. For the analysis the Swedish District Heating Association's district heating system statistics has been used. The district heating system statistics shows that the cost for corrosion damages is high, and pipes older than 20 years have increased risk for corrosion. The knowledge about corrosion concerning steel poles and water pipes in soils can not be applied to external corrosion of steel pipes in district heating systems. The corrosion rate of steel poles in soils is low. The corrosion of steel pipes in district heating systems can locally give high rates, up to 0,5 mm/year. The mechanism for this type of corrosion is different compared to the corrosion mechanism of poles in soils. The temperature is higher and aggressive water, with road-salt and chloride content, falls in drops on the steel pipe, and impurities evaporate on the steel surface. These factors increase the corrosion rate. If the material thickness is 5 mm, fracture can occur in the pipe within ten years. The number of copper pipe corrosion damage is limited. The most determining corrosion factors of copper pipes are pH-value and impurities as chloride and sulphate in the water. Stainless steel pipes of type 304 can not be used in soils due to the risk of local corrosion. Higher alloyed stainless steels, with molybdenum and higher chromium content should be used. It is concluded that failures can occur due to external corrosion of steel pipes. This failure is expensive and can lead to human damage. One way to eliminate failures of steel pipes is to carry out risk analysis.

  15. Numerical Model for Conduction-Cooled Current Lead Heat Loads

    CERN Document Server

    White, M J; Brueck, H D; 10.1063/1.4706965

    2012-01-01

    Current leads are utilized to deliver electrical power from a room temperature junction mounted on the vacuum vessel to a superconducting magnet located within the vacuum space of a cryostat. There are many types of current leads used at laboratories throughout the world, however, conduction-cooled current leads are often chosen for their simplicity and reliability. Conduction-cooled leads have the advantage of using common materials, have no superconducting/normal state transition, and have no boil-off vapor to collect. The XFEL (X-Ray Free Electron Laser) magnets are operated at 2 K, which makes vapor-cooled current leads impractical due to the sub-atmospheric bath pressure. This paper presents a numerical model for conduction-cooled current lead heat loads. This model takes into account varying material and fluid thermal properties, varying thicknesses along the length of the lead, heat transfer in the circumferential and longitudinal directions, electrical power dissipation, and the effect of thermal inte...

  16. The Integration of Internal and External Training Load Metrics in Hurling.

    Science.gov (United States)

    Malone, Shane; Doran, Dominic; Akubat, Ibrahim; Collins, Kieran

    2016-12-01

    The current study aimed to assess the relationship between the hurling player's fitness profile and integrated training load (TL) metrics. Twenty-five hurling players performed treadmill testing for VO2max, the speed at blood lactate concentrations of 2 mmol•L-1 (vLT) and 4 mmol•L-1 (vOBLA) and the heart rate-blood lactate profile for calculation of individual training impulse (iTRIMP). The total distance (TD; m), high speed distance (HSD; m) and sprint distance (SD; m) covered were measured using GPS technology (4-Hz, VX Sport, Lower Hutt, New Zealand) which allowed for the measurement of the external TL. The external TL was divided by the internal TL to form integration ratios. Pearson correlation analyses allowed for the assessment of the relationships between fitness measures and the ratios to performance during simulated match play. External measures of the TL alone showed limited correlations with fitness measures. Integrated TL ratios showed significant relationships with fitness measures in players. TD:iTRIMP was correlated with aerobic fitness measures VO2max (r = 0.524; p = 0.006; 95% CI: 0.224 to 0.754; large) and vOBLA (r = 0.559; p = 0.003; 95% CI: 0.254 to 0.854; large). HSD:iTRIMP also correlated with aerobic markers for fitness vLT (r = 0.502; p = 0.009; 95% CI: 0.204 to 0.801; large); vOBLA (r = 0.407; p = 0.039; 95% CI: 0.024 to 0.644; moderate). Interestingly SD:iTRIMP also showed significant correlations with vLT (r = 0.611; p = 0.001; 95% CI: 0.324 to 0.754; large). The current study showed that TL ratios can provide practitioners with a measure of fitness as external performance alone showed limited relationships with aerobic fitness measures.

  17. Individualised internal and external training load relationships in elite wheelchair rugby players

    Directory of Open Access Journals (Sweden)

    Thomas Andrew William Paulson

    2015-12-01

    Full Text Available Aim: The quantification and longitudinal monitoring of athlete training load (TL provides a scientific explanation for changes in performance and helps manage injury/illness risk. The aim of the present study was to establish the relationship between measures of internal (heart rate (HR and session RPE (sRPE and external TL specific to wheelchair rugby (WR. Methods: Fourteen international WR athletes (age = 29 ± 7 yrs; body mass = 58.9 ± 10.9 kg were monitored during 18 training sessions over a 3 month period. Activity profiles were collected during each training session using a radio-frequency based indoor tracking system. External TL was quantified by total distance (m covered as well as time spent and distance covered in a range of classification-specific arbitrary speed zones. Banister’s TRIMP, Edwards’s summated HR zone (SHRZ and Lucia’s TRIMP methods were used to quantify physiological internal TL. sRPE was calculated as the product of session duration multiplied by perceived exertion using the Borg CR10 scale. Relationships between external and internal TL were examined using correlation coefficients and the 90% confidence intervals (90% CI. Results: sRPE (r=0.59 and all HR-based (r >0.80 methods showed large and very large relationships with the total distance covered during training sessions, respectively. Large and very large correlations (r =0.56-0.82 were also observed between all measures of internal TL and times spent and distances covered in low and moderate intensity speed zones. HR-based methods showed very large relationships with time (r=0.71-0.75 and distance (r=0.70-0.73 in the very high speed zone and a large relationship with the number of high intensity activities performed (r=0.56-0.62. Weaker relationships (r=0.32–0.35 were observed between sRPE and all measures of high intensity activity. A large variation of individual correlation co-efficient was observed between sRPE and all external TL measures

  18. NETWORK MODEL AND ALGORITHM FOR SOLVING PROBLEM OF OPTIMUM THERMAL LOAD DISTRIBUTION AMONG HEAT-SOURCES OF ENTERPRISE HEATING SYSTEM

    Directory of Open Access Journals (Sweden)

    V. A. Sednin

    2010-01-01

    Full Text Available The paper  presents an algorithm for optimization of thermal load distribution among heat-sources in the system of centralized heat supply. The algorithm can be used while elaborating plans for development of heat supply systems in cities and settlements.

  19. Heat load characteristics and new design using one-coil model superconducting magnets

    Science.gov (United States)

    Jizo, Yoshihiro; Akagi, Hidenari; Yamaguchi, Takashi; Terai, Motoaki; Shinobu, Masatoshi

    Superconducting magnets (SCM) for Maglev trains are vibrated by the electromagnetic force arising from the magnetic field of higher harmonics, which is due to the arrangement of the ground coils. The heat load within the liquid helium temperature region increases by the vibration of the magnets. This paper reports a heat load generation estimation mechanism due to the above-mentioned vibration, as well as effective measures of reducing heat load generation. In addition, we show how a one-coil type SCM can reduce the heat load generation in electromagnetic disturbance tests.

  20. Examining the External Training Load of an English Premier League Football Team With Special Reference to Acceleration.

    Science.gov (United States)

    Akenhead, Richard; Harley, Jamie A; Tweddle, Simon P

    2016-09-01

    Akenhead, R, Harley, J, and Tweddle, S. Examining the external training load of an English Premier League football team with special reference to acceleration. J Strength Cond Res 30(9): 2424-2432, 2016-Practitioners and coaches often use external training load variables such as distance run and the number of high-speed running (HSR) activities to quantify football training. However, an important component of the external load may be overlooked when acceleration activities are not considered. The aim of this study was to describe the within-microcycle distribution of external load, including acceleration, during in-season 1-game weeks in an elite football team. Global Positioning System technology was used to collect time-motion data from 12 representative 7-day microcycles across a competitive season (48 training days, 295 data sets). Training time, total distance (TD), high-speed running (HSR) distance (>5.8 m·s), sprint running distance (>6.7 m·s) and acceleration variables were recorded during each training session. Data were analysed for interday and interposition differences using mixed linear modeling. The distribution of external load was characterized by the second training day of the microcycle (5 days prematch) exhibiting the highest values for all variables of training load, with the fourth day (1 day prematch) exhibiting the lowest values. Central midfield players covered ∼8-16% greater TD than other positions excluding wide midfielders (p ≤ 0.03, d = 0.2-0.4) and covered ∼17% greater distance accelerating 1-2 m·s than central defenders (p = 0.03, d = 0.7). When expressed relative to training duration and TD, the magnitude of interday and interposition differences were markedly reduced (p = 0.03, d = 0.2-0.3). When managing the distribution of training load, practitioners should be aware of the intensity of training sessions and consider the density of external load within sessions.

  1. To Problem Pertaining to Calculation of Resistance to Heat Transfer in Modern Structures of Building External Walls

    Directory of Open Access Journals (Sweden)

    L. V. Nesterov

    2007-01-01

    Full Text Available The paper presents a new methodology for determination of resistance to heat transfer of building external walls with the introduction of heat engineering uniformity factors obtained on the basis of calculating two- and three-dimensional temperature pattern. The methodology makes it possible to take into account influence of joints, connections with adjoining structures and jambs of external walls.

  2. The effect of external heat transfer on thermal explosion in a spherical vessel with natural convection.

    Science.gov (United States)

    Campbell, A N

    2015-07-14

    When any exothermic reaction proceeds in an unstirred vessel, natural convection may develop. This flow can significantly alter the heat transfer from the reacting fluid to the environment and hence alter the balance between heat generation and heat loss, which determines whether or not the system will explode. Previous studies of the effects of natural convection on thermal explosion have considered reactors where the temperature of the wall of the reactor is held constant. This implies that there is infinitely fast heat transfer between the wall of the vessel and the surrounding environment. In reality, there will be heat transfer resistances associated with conduction through the wall of the reactor and from the wall to the environment. The existence of these additional heat transfer resistances may alter the rate of heat transfer from the hot region of the reactor to the environment and hence the stability of the reaction. This work presents an initial numerical study of thermal explosion in a spherical reactor under the influence of natural convection and external heat transfer, which neglects the effects of consumption of reactant. Simulations were performed to examine the changing behaviour of the system as the intensity of convection and the importance of external heat transfer were varied. It was shown that the temporal development of the maximum temperature in the reactor was qualitatively similar as the Rayleigh and Biot numbers were varied. Importantly, the maximum temperature in a stable system was shown to vary with Biot number. This has important consequences for the definitions used for thermal explosion in systems with significant reactant consumption. Additionally, regions of parameter space where explosions occurred were identified. It was shown that reducing the Biot number increases the likelihood of explosion and reduces the stabilising effect of natural convection. Finally, the results of the simulations were shown to compare favourably with

  3. Pulse mitigation and heat transfer enhancement techniques. Volume 4: Transient behavior of heat pipe with thermal energy storage under pulse heat loads

    Science.gov (United States)

    Chow, L. C.; Chang, M. J.

    1992-08-01

    A novel design of a high-temperature axially grooved heat pipe (HP), which utilizes thermal energy storage (TES) to mitigate pulse heat loads, was presented. Phase-change material (PCM) encapsulated in cylindrical containers was used for thermal energy storage. The transient responses of the HP/TES system under two types of pulse heat loads were studied numerically. The first type is pulse heat loads applied at the heat pipe evaporator; the second type is reversed-pulse heat loads applied at the condenser. The transient response of three different HP/TES configurations were compared: (1) a heat pipe with a large empty cylinder installed in the vapor core, (2) a heat pipe with a large PCM cylinder, and (3) a heat pipe with six small PCM cylinders. It was found that the PCM is very effective in mitigating the adverse effect of pulse heat loads. The six small PCM cylinders are more efficient than the large PCM cylinder in relaxing the heat pipe temperature increase under pulse heat loads.

  4. Influence of high temperatures and relative humidity on heat exchange of miners subjected to measured physical load

    Energy Technology Data Exchange (ETDEWEB)

    Knapik, Z.; Lyubchin' ska-Koval' ska, V.; Kozerovski, Ch.; Yuzva, V.; Tsader, Ya.; Ponerevka, E.; Paradovski, L.; Stolyarska, B.

    1987-12-01

    Investigates influence of microclimate of mines (temperature and humidity) on health of miners. Two groups of healthy men (18 to 45 and 46 to 58 years of age) performed controlled amounts of physical work on a bicycle ergometer under conditions of microclimate of mines at temperatures of 28 to 34 C and relative humidity of 100%. Increase in body heat of miners was measured by a thermocouple in the external auditory meatus 1 to 2 mm from the eardrum. Results showed a significant increase in internal temperature of body and that internal temperature of body rises with increases in external temperatures from 28 to 34 C. Conditions of test in which healthy men carry out controlled work loads significantly decrease removal of endogenous heat from body. Humidity of 100% eliminates removal of body heat by evaporation, radiation and convection. Overheating of body produces exhaustion, loss of concentration, limits diuresis and thickens urine. Miners over 45 years of age overheat more than younger men under the same conditions and work loads; men of greater body weight exhibit the same response. Tables determining approximate energy demands at the time of carrying out controlled physical work loads must take into consideration size of body, temperature of work place and relative humidity of air. 6 refs.

  5. Time Domain Simulation of Transient Responses of Very Large Floating Structures Under Unsteady External Loads

    Institute of Scientific and Technical Information of China (English)

    QIU Liu-chao; LIU Hua

    2005-01-01

    A time domain finite element method (FEM) for the analysis of transient elastic response of a very large floating structure (VLFS) subjected to arbitrary time-dependent external loads is presented. This method is developed directly in time domain and the hydrodynamic problem is formulated based on linear, inviscid and slightly compressible fluid theory and the structural response is analyzed on the thin plate assumption. The time domain finite element procedure herein is validated by comparing numerical results with available experimental data. Finally, the transient elastic response of a pontoon-type VLFS under the landing of an airplane is computed by the proposed time domain FEM. The time histories of the applied force and the position and velocity of an airplane during landing are modeled with data from a Boeing 747-400 jumbo jet.

  6. Intelligent Control of Diesel Generators Using Gain-Scheduling Based on Online External-Load Estimation

    DEFF Research Database (Denmark)

    Mai, Christian; Jepsen, Kasper Lund; Yang, Zhenyu;

    2014-01-01

    keep a consistent performance for a wide range of operating conditions. Technically, a general nonlinear dynamic model is firstly developed based on fundamental principles of diesel generators. Then, the system parameters of this model can be identified experimentally or partially retrieved from...... the data-sheet for a specific unit. By combining an online external-load estimation with this specific units model, finally an intelligent control using the online gain scheduling strategy is proposed. The proposed solution is verified and analyzed based on a lab-sized emulator of a diesel generator, where...... a controlled AC-motor is employed to emulate a diesel engine. The testing results clearly show that the proposed control solution can lead to a better overall system performance than most existing solutions do, especially subject to widely diverse operating conditions....

  7. Internal (Annular) and Compressible External (Flat Plate) Turbulent Flow Heat Transfer Correlations.

    Energy Technology Data Exchange (ETDEWEB)

    Dechant, Lawrence [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Smith, Justin [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2016-01-01

    Here we provide a discussion regarding the applicability of a family of traditional heat transfer correlation based models for several (unit level) heat transfer problems associated with flight heat transfer estimates and internal flow heat transfer associated with an experimental simulation design (Dobranich 2014). Variability between semi-empirical free-flight models suggests relative differences for heat transfer coefficients on the order of 10%, while the internal annular flow behavior is larger with differences on the order of 20%. We emphasize that these expressions are strictly valid only for the geometries they have been derived for e.g. the fully developed annular flow or simple external flow problems. Though, the application of flat plate skin friction estimate to cylindrical bodies is a traditional procedure to estimate skin friction and heat transfer, an over-prediction bias is often observed using these approximations for missile type bodies. As a correction for this over-estimate trend, we discuss a simple scaling reduction factor for flat plate turbulent skin friction and heat transfer solutions (correlations) applied to blunt bodies of revolution at zero angle of attack. The method estimates the ratio between axisymmetric and 2-d stagnation point heat transfer skin friction and Stanton number solution expressions for sub-turbulent Reynolds numbers %3C1x10 4 . This factor is assumed to also directly influence the flat plate results applied to the cylindrical portion of the flow and the flat plate correlations are modified by

  8. Study of the collector/heat pipe cooled externally configured thermionic diode

    Science.gov (United States)

    1973-01-01

    A collector/heat pipe cooled, externally configured (heated) thermionic diode module was designed for use in a laboratory test to demonstrate the applicability of this concept as the fuel element/converter module of an in-core thermionic electric power source. During the course of the program, this module evolved from a simple experimental mock-up into an advanced unit which was more reactor prototypical. Detailed analysis of all diode components led to their engineering design, fabrication, and assembly, with the exception of the collector/heat pipe. While several designs of high power annular wicked heat pipes were fabricated and tested, each exhibited unexpected performance difficulties. It was concluded that the basic cause of these problems was the formation of crud which interfered with the liquid flow in the annular passage of the evaporator region.

  9. Effects of external loading on lumbar extension moment during squat lifting

    Directory of Open Access Journals (Sweden)

    Iman Vahdat

    2017-08-01

    Full Text Available Objectives: The main objective of this study has been qualitative investigation of the effects of external loading on the lumbar extension moment during squat lifting. Findings of this study may allow to determine the factor with the most considerable effect on the lumbar extension moment and may help determine the lumbar spine risk factors at temporo-spatial coordination during squat lifting. Material and Methods: Twelve healthy men volunteered to perform slow and fast squat lifting of a box of varied mass (4 kg, 8 kg and 12 kg. The eight-channel electromyography was applied to detect the activities of abdominal (rectus abdominis and external oblique and lower back muscles (iliocostalis lumborum and multifidus. The lumbar extension moment was calculated using 3D linked segment model. Ground reaction forces and kinematic data were recorded using a Vicon system with 2 parallel Kistler force-plates. Results: Significant increases (both p-values 0.05 were detected between the lumbar angles related to the lower trunk muscles peak activities and lumbar angle related to the peak lumbar extension moment in most of the lifts. Conclusions: According to the findings, the inertial force of the lifted box is the most important factor that affects the lumbar extension moment during squat lifting. Moreover, critical lumbar angles are seemingly those ones in which the lifted box reaches the peak acceleration. Int J Occup Med Environ Health 2017;30(4:665–679

  10. Parametric experiments and CFD analysis on condensation heat transfer performance of externally condensing tubes

    Energy Technology Data Exchange (ETDEWEB)

    Jeon, Byong Guk; Kim, Do Yun; Shin, Chang Wook; NO, Hee Cheon, E-mail: hcno@kaist.ac.kr

    2015-11-15

    Highlights: • Geometric effects of HXs on external condensation are experimentally observed. • Lower tube angle has higher heat transfer coefficients over vertical tubes by 15–30%. • 2.68 cmD tube has higher heat transfer coefficients over 4.91 cmD tube roughly by 10–20%. • CFD approach is validated against our experiments with good accuracy (error ∼7%). - Abstract: To ensure safe operation of nuclear power plants even in the case of a prolonged station blackout, advanced reactors adopt passive systems that can operate without electricity supply. In Korea, a passive auxiliary feedwater system was successfully validated, and a passive containment cooling system (PCCS) has recently attracted attention. To investigate the thermal performance of PCCSs, we perform various experiments with external heat exchangers, which condense steam externally, for PCCSs. Through experiments, we construct a database for the lower air mass fraction and perform a parametric study on the tube inclination and diameter. The operating ranges for the experiments are 0.24–0.38 MPa (pressure), 0.06–0.4 (air mass fraction), and 0–90° (tube inclination). A lower tube inclination and smaller tube diameter are found to yield higher heat-transfer coefficients, by approximately 20%. In the prediction of condensation heat-transfer coefficients, experimental correlations and the heat–mass transfer analogy have limitations in both accuracy and applicability. A computational-fluid-dynamics approach is used with the aid of user-defined functions to calculate the heat-transfer coefficients. The resulting predictions exhibit an average error of 7% when the air mass fraction is higher than 0.2.

  11. Natural convection heat transfer coefficients in phase change material (PCM) modules with external vertical fins

    Energy Technology Data Exchange (ETDEWEB)

    Castell, Albert; Sole, Cristian; Medrano, Marc; Roca, Joan; Cabeza, Luisa F. [Departament d' Informatica i Enginyeria Industrial, Universitat de Lleida, Pere de Cabrera s/n, 25001 Lleida (Spain); Garcia, Daniel [Departament Projectes d' Enginyeria, Universitat Politecnica de Catalunya, Colom 11, 08222 Terrassa (Spain)

    2008-09-15

    To determine the heat transfer coefficient by natural convection for specific geometries, experimental correlations are used. No correlations were found in the literature for the geometries studied in this work. These geometries consisted of a cylindrical module of 88 mm of diameter and 315 mm height with external vertical fins of 310 mm height and 20 and 40 mm length. To determine the heat transfer coefficient by natural convection, experimental work was done. This module, containing PCM (sodium acetate trihydrate), was situated in the middle upper part of a cylindrical water tank of 440 mm of diameter and 450 mm height. The calculated heat transfer coefficient changed by using external fins, as the heat transfer surface was increased. The temperature variation of the PCM and the water are presented as a function of time, and the heat transfer coefficient for different fins is presented as a function of the temperature difference. Experimental correlations were obtained, presenting the Nusselt number as a function of different dimensionless numbers. Different correlations were analysed to find which one fit better to the experimental data. (author)

  12. High-intensity tasks with external load in military applications: a review.

    Science.gov (United States)

    O'Neal, Eric K; Hornsby, Jared H; Kelleran, Kyle J

    2014-09-01

    This article provides a synopsis of the limited investigations examining the impact of external load (EL) on performance of high-intensity tasks under load (HITL), EL training intervention effects on HITL performance, and injuries from EL training. Repetitive lifting tasks and initiation of locomotion, such as rapidly moving from a prone position to sprinting appear to be more hindered by EL than maximal sprinting velocity and may explain why training with EL does not improve obstacle course or prolonged (200-300 yard shuttle) drills. EL training appears to offer very little if any benefit for HITL in lesser trained populations. This contrast results of multiple studies incorporating ≥ 3 weeks of prolonged hypergravity interventions (wearing EL during daily activities) in elite anaerobic athletes, indicating EL training stimulus is likely only beneficial to well-trained soldiers. Women and lesser trained individuals appear to be more susceptible to increased injury with EL training. A significant limitation concerning current HITL knowledge is the lack of studies incorporating trained soldiers. Future investigations concerning the effects of HITL on marksmanship, repetitive lifting biomechanics, efficacy of hypergravity training for military personnel, and kinematics of sprinting from tactical positions with various EL displacements and technique training are warranted.

  13. Daily simulations of urban heat load in Vienna for 2011

    Science.gov (United States)

    Hollosi, Brigitta; Zuvela-Aloise, Maja; Koch, Roland

    2014-05-01

    In this study, the dynamical urban climate model MUKLIMO3 (horizontal resolution of 100 m) is uni-directionally coupled with the operational weather forecast model ALARO-ALADIN of the ZAMG (horizontal resolution of 4.8 km) to simulate the development of the urban heat island in Vienna on a daily basis. The aim is to evaluate the performance of the urban climate model applied for climatological studies in a weather prediction mode. The focus of the investigation is on assessment of the urban heat load during day-time. We used the archived daily forecast data for the summer period in 2011 (April - October) as input data for the urban climate model. The high resolution simulations were initialized with vertical profiles of temperature and relative humidity and prevailing wind speed and direction in the rural area near the city in the early morning hours. The model output for hourly temperature and relative humidity has been evaluated against the monitoring data at 9 weather stations in the area of the city. Additionally, spatial gradients in temperature were evaluated by comparing the grid point values with the data collected during a mobile measuring campaign taken on a multi-vehicle bicycle tour on the 7th of July, 2011. The results show a good agreement with observations on a district scale. Particular challenge in the modeling approach is achieving robust and numerically stable model solutions for different weather situation. Therefore, we analyzed modeled wind patterns for different atmospheric conditions in the summer period. We found that during the calm hot days, due to the inhomogeneous surface and complex terrain, the local-scale temperature gradients can induce strong anomalies, which in turn could affect the circulation on a larger scale. However, these results could not be validated due to the lack of observations. In the following years extreme hot conditions are very likely to occur more frequently and with higher intensity. Combining urban climate

  14. Scaling STI's sapphire cryocooler for applications requiring higher heat loads

    Science.gov (United States)

    Karandikar, Abhijit; Fiedler, Andreas

    2012-06-01

    Superconductor Technologies Inc. (STI) developed the Sapphire cryocooler specifically for the SuperLink® product; a high performance superconducting Radio Frequency (RF) front-end receiver used by wireless carriers such as Verizon Wireless and AT&T to improve network cell coverage and data speeds. STI has built and deployed over 6,000 systems operating 24 hours a day (24/7), 7 days a week in the field since 1999. Sapphire is an integrated free piston Stirling cycle cryocooler with a cooling capacity of 5 Watts at 77 Kelvin (K) with less than 100 Watts (W) input power. It has a field-proven Mean Time Between Failure (MTBF) of well over 1 million hours, requires zero maintenance and has logged over 250 million cumulative runtime hours. The Sapphire cooler is built on a scalable technology platform, enabling the design of machines with cooling capacities greater than 1 kilowatt (kW). This scalable platform also extends the same outstanding attributes as the Sapphire cooler, namely high reliability, zero maintenance, and compact size - all at a competitive cost. This paper will discuss emerging applications requiring higher heat loads and these attributes, describe Sapphire, and show a preliminary concept of a scaled machine with a 100 W cooling capacity.

  15. Flow boiling critical heat flux enhancement by using magnetic nanofluids and external magnetic fields

    Energy Technology Data Exchange (ETDEWEB)

    Lee, T.; Jeong, Y.H. [Korea Advanced Inst. of Science and Tech., Daejeon (Korea, Republic of)

    2011-07-01

    By using the nanofluid as a working fluid, we can expect the enhancement in the flow boiling critical heat flux mainly due to the deposition of nanoparticles on the heat transfer surface. In this study, we suggest the magnetic nanofluid, or magnetite-water nanofluid, as a working fluid which is regarded as a controllable nanofluid, that is, nanoparticles or magnetite nanoparticles in a nanofluid can be controlled by an external magnetic field. Therefore, we can expect the advantages of magnetic nanofluid such as, i) control of nanofluid concentration to maintain nanoparticle suspension and to localize nanofluid concentration, and ii) removal of nanoparticle from nanofluid when we want. In this study, we focused on the investigation of flow boiling critical heat flux characteristics for the magnetic nanofluid. Series of experiments were performed under the low pressure and low flow conditions, and based on the experimental results; we can conclude that the use of magnetic nanofluid improves the flow boiling critical heat flux characteristics. This is mainly due to the deposition of magnetite nanoparticles on the heat transfer surface, which results in the improvement of wettability and re-wetting characteristics of heat transfer surface. Preliminary results of the magnetic field effects on the flow boiling critical heat flux would be presented also. (author)

  16. A combined gray neural network model of seasonal heating load forecast

    Institute of Scientific and Technical Information of China (English)

    QIAOXiaozhuang; YANGChangzhi

    2003-01-01

    Seasonal heating load time sequence has the double trends of increasing and fluctuating, so it''s difficult to select a model to forecast it. In this paper, a combined model of gray model and artificial neural network model was presented to forecast seasonal heating load. A concrete model was established and was verified through actual examples.

  17. The Integration of Internal and External Training Load Metrics in Hurling

    Directory of Open Access Journals (Sweden)

    Malone Shane

    2016-12-01

    Full Text Available The current study aimed to assess the relationship between the hurling player’s fitness profile and integrated training load (TL metrics. Twenty-five hurling players performed treadmill testing for VO2max, the speed at blood lactate concentrations of 2 mmol•L-1 (vLT and 4 mmol•L-1 (vOBLA and the heart rate-blood lactate profile for calculation of individual training impulse (iTRIMP. The total distance (TD; m, high speed distance (HSD; m and sprint distance (SD; m covered were measured using GPS technology (4-Hz, VX Sport, Lower Hutt, New Zealand which allowed for the measurement of the external TL. The external TL was divided by the internal TL to form integration ratios. Pearson correlation analyses allowed for the assessment of the relationships between fitness measures and the ratios to performance during simulated match play. External measures of the TL alone showed limited correlations with fitness measures. Integrated TL ratios showed significant relationships with fitness measures in players. TD:iTRIMP was correlated with aerobic fitness measures VO2max (r = 0.524; p = 0.006; 95% CI: 0.224 to 0.754; large and vOBLA (r = 0.559; p = 0.003; 95% CI: 0.254 to 0.854; large. HSD:iTRIMP also correlated with aerobic markers for fitness vLT (r = 0.502; p = 0.009; 95% CI: 0.204 to 0.801; large; vOBLA (r = 0.407; p = 0.039; 95% CI: 0.024 to 0.644; moderate. Interestingly SD:iTRIMP also showed significant correlations with vLT (r = 0.611; p = 0.001; 95% CI: 0.324 to 0.754; large. The current study showed that TL ratios can provide practitioners with a measure of fitness as external performance alone showed limited relationships with aerobic fitness measures.

  18. Beam heat load and pressure rise in a cold vacuum chamber

    Directory of Open Access Journals (Sweden)

    S. Casalbuoni

    2007-09-01

    Full Text Available The beam heat load and the pressure in the vacuum chamber of the cold bore superconducting undulator installed at ANKA (ANgstrom source KArlsruhe have been monitored for almost two years. Possible sources of the observed heat load could be synchrotron radiation from upstream magnets, image currents, electron and ion bombardment. In this paper, the various possible contributions to the heat load are discussed and compared with experimental results. The dynamic pressure increases nonlinearly with the average beam current. The current where it assumes a maximum varies both with the bunch intensity and with the initial vacuum pressure. A correlation between the heat load and the dynamic pressure has been observed. This study suggests that electron bombardment could explain the beam heat load and pressure rise observed for a bunch length of 10 mm.

  19. Phenomenology of break-up modes in contact free externally heated nanoparticle laden fuel droplets

    Science.gov (United States)

    Pathak, Binita; Basu, Saptarshi

    2016-12-01

    We study thermally induced atomization modes in contact free (acoustically levitated) nanoparticle laden fuel droplets. The initial droplet size, external heat supplied, and suspended particle concentration (wt. %) in droplets govern the stability criterion which ultimately determines the dominant mode of atomization. Pure fuel droplets exhibit two dominant modes of breakup namely primary and secondary. Primary modes are rather sporadic and normally do not involve shape oscillations. Secondary atomization however leads to severe shape deformations and catastrophic intense breakup of the droplets. The dominance of these modes has been quantified based on the external heat flux, dynamic variation of surface tension, acoustic pressure, and droplet size. Addition of particles alters the regimes of the primary and secondary atomization and introduces bubble induced boiling and bursting. We analyze this new mode of atomization and estimate the time scale of bubble growth up to the point of bursting using energy balance to determine the criterion suitable for parent droplet rupture. All the three different modes of breakup have been well identified in a regime map determined in terms of Weber number and the heat utilization rate which is defined as the energy utilized for transient heating, vaporization, and boiling in droplets.

  20. Sensitivity Analysis of Depletion Parameters for Heat Load Evaluation of PWR Spent Fuel Storage Pool

    Energy Technology Data Exchange (ETDEWEB)

    Kim, In Young; Lee, Un Chul [Seoul National University, Seoul (Korea, Republic of)

    2011-12-15

    As necessity of safety re-evaluation for spent fuel storage facility has emphasized after the Fukushima accident, accuracy improvement of heat load evaluation has become more important to acquire reliable thermal-hydraulic evaluation results. As groundwork, parametric and sensitivity analyses of various storage conditions for Kori Unit 4 spent fuel storage pool and spent fuel depletion parameters such as axial burnup effect, operation history, and specific heat are conducted using ORIGEN2 code. According to heat load evaluation and parametric sensitivity analyses, decay heat of last discharged fuel comprises maximum 80.42% of total heat load of storage facility and there is a negative correlation between effect of depletion parameters and cooling period. It is determined that specific heat is most influential parameter and operation history is secondly influential parameter. And decay heat of just discharged fuel is varied from 0.34 to 1.66 times of average value and decay heat of 1 year cooled fuel is varied from 0.55 to 1.37 times of average value in accordance with change of specific power. Namely depletion parameters can cause large variation in decay heat calculation of short-term cooled fuel. Therefore application of real operation data instead of user selection value is needed to improve evaluation accuracy. It is expected that these results could be used to improve accuracy of heat load assessment and evaluate uncertainty of calculated heat load.

  1. Possible role of external radial electric field on ion heating in an FRC

    Science.gov (United States)

    Gupta, Deepak; Trask, E.; Korepanov, S.; Granstedt, E.; Osin, D.; Roche, T.; Deng, B.; Beall, M.; Zhai, K.; TAE Team

    2016-10-01

    In C-2/C-2U FRCs, a radial electric field is applied by either plasma guns or biased electrodes inside the divertors, at both ends of the machine. The electric field plays an important role in stabilizing the FRC; thus, providing a favorable target condition to a neutral beam injection. In addition, it is also observed that the application of radial electric field may lead to a heating of ions. Radial profile of impurity ion emission, azimuthal velocity and temperature are measured under different configurations. The conditions and evidences of ion heating due to the electric field biasing will be presented and discussed. Radial momentum balance equation of oxygen impurity ions is used with these measurements to estimate the radial electric field profile. Parameters affecting the ion heating due to biasing will also be discussed with some correlations. The external radial electric field is planned to be applied by biased electrodes and plasma guns in C-2W inner/outer divertors.

  2. Allothermal gasification of biomass using micron size biomass as external heat source.

    Science.gov (United States)

    Cheng, Gong; Li, Qian; Qi, Fangjie; Xiao, Bo; Liu, Shiming; Hu, Zhiquan; He, Piwen

    2012-03-01

    An allothermal biomass gasification system using biomass micron fuel (BMF) as external heat source was developed. In this system, heat supplied to gasifier was generated from combustion of BMF. Biomass feedstock was gasified with steam and then tar in the produced gas was decomposed in a catalytic bed with NiO/γ-Al(2)O(3) catalyst. Finally the production gas was employed as a substitute for civil fuel gas. An overall energy analysis of the system was also investigated. The results showed that the lower heating value of the product gas reached more than 12 MJ/Nm(3). The combusted BMF accounted for 26.8% of the total energy input. Allothermal gasification based on the substituted BMF for conventional energy was an efficient and economical technology to obtain bioenergy.

  3. Effect of Court Dimensions on Players' External and Internal Load during Small-Sided Handball Games.

    Science.gov (United States)

    Corvino, Matteo; Tessitore, Antonio; Minganti, Carlo; Sibila, Marko

    2014-05-01

    The aim of this study was to investigate the effect of three different court dimensions on the internal and external load during small-sided handball games. Six male amateur handball players took part in this study and participated in three different 8-min 3vs3 (plus goalkeepers) small-sided handball games (each repeated twice). The three court dimensions were 12×24m, 30×15m and 32×16m. Through Global Positioning System devices (SPI pro elite 15Hz, GPSports) and video analysis, the following parameters were recorded: cyclic and acyclic movements (distance covered and number of technical actions executed), heart rate, and rating of perceived exertion (RPE). Total distance travelled increased with court dimensions (885.2m ± 66.6m in 24×12m; 980.0m ± 73.4m in 30×15m; 1095.0m ± 112.9m in 32×16m, p 5.2 m·s(-1)) highlighted substantial differences: playing with the 30×15m court in comparison to the 24×12m, the players covered less distance in the first speed zone (p = 0.012; ES = 0.70) and more distance in the second (p = 0.049; ES = 0.73) and third (p = 0.012; ES = 0.51) speed zones. Statistical differences were also found between the 24×12m and 32×16m courts: the players covered more distance in the second and third speed zones (p = 0.013, ES = 0.76; p = 0.023 ES = 0.69) with the 32×16m court in comparison to the 24×12m. There was no significant effect of court dimensions on the technical parameters (number of team actions, passes, piston movements toward goal and defensive activities), the number of specific handball jumps and changes of direction, and the time spent in the different heart rate zones. Considering the average data of all the experimental conditions together (24×12m, 30×15m, 32×16m), a pronounced statistical difference was highlighted between the values in first two HR zones and the last two (p games can be used to manipulate both external and internal loads on the players. Key pointsTo cover the specific game demands, more specific

  4. Effect of Court Dimensions on Players’ External and Internal Load during Small-Sided Handball Games

    Directory of Open Access Journals (Sweden)

    Matteo Corvino

    2014-06-01

    Full Text Available The aim of this study was to investigate the effect of three different court dimensions on the internal and external load during small-sided handball games. Six male amateur handball players took part in this study and participated in three different 8-min 3vs3 (plus goalkeepers small-sided handball games (each repeated twice. The three court dimensions were 12×24m, 30×15m and 32×16m. Through Global Positioning System devices (SPI pro elite 15Hz, GPSports and video analysis, the following parameters were recorded: cyclic and acyclic movements (distance covered and number of technical actions executed, heart rate, and rating of perceived exertion (RPE. Total distance travelled increased with court dimensions (885.2m ± 66.6m in 24×12m; 980.0m ± 73.4m in 30×15m; 1095.0m ± 112.9m in 32×16m, p 5.2 m·s-1 highlighted substantial differences: playing with the 30×15m court in comparison to the 24×12m, the players covered less distance in the first speed zone (p = 0.012; ES = 0.70 and more distance in the second (p = 0.049; ES = 0.73 and third (p = 0.012; ES = 0.51 speed zones. Statistical differences were also found between the 24×12m and 32×16m courts: the players covered more distance in the second and third speed zones (p = 0.013, ES = 0.76; p = 0.023 ES = 0.69 with the 32×16m court in comparison to the 24×12m. There was no significant effect of court dimensions on the technical parameters (number of team actions, passes, piston movements toward goal and defensive activities, the number of specific handball jumps and changes of direction, and the time spent in the different heart rate zones. Considering the average data of all the experimental conditions together (24×12m, 30×15m, 32×16m, a pronounced statistical difference was highlighted between the values in first two HR zones and the last two (p < 0.05; large ES. The rating of perceived exertion was significantly higher during the drill with the 32×16m court compared with the 24

  5. Mechanical performance of external fixators with wires for the treatment of bone fractures--Part I: Load-displacement behavior.

    Science.gov (United States)

    Delprete, C; Gola, M M

    1993-02-01

    Using matrix algebra, a mathematical model is formulated for a particular type of external fixator with wires (system developed by Ilizarov) for the treatment of bone fractures. The mathematical model is used to give a linear estimate of the stiffness under lateral and axial loads in a representative number of practical conditions. Relative displacements of the bone ends at the fracture site are calculated not only in the common case of a gap, but also for various angles of inclined sliding contact; in this case, a realistic load is applied and nonlinear stiffening of the wires under transversal loads is iteratively taken into account.

  6. Quantifying external load in Australian football matches and training using accelerometers.

    Science.gov (United States)

    Boyd, Luke J; Ball, Kevin; Aughey, Robert J

    2013-01-01

    To describe the external load of Australian football matches and training using accelerometers. Nineteen elite and 21 subelite Australian footballers wore accelerometers during matches and training. Accelerometer data were expressed in 2 ways: from all 3 axes (player load; PL) and from all axes when velocity was below 2 m/s (PLSLOW). Differences were determined between 4 playing positions (midfielders, nomadics, deeps, and ruckmen), 2 playing levels (elite and subelite), and matches and training using percentage change and effect size with 90% confidence intervals. In the elite group, midfielders recorded higher PL than nomadics and deeps did (8.8%, 0.59 ± 0.24; 34.2%, 1.83 ± 0.39 respectively), and ruckmen were higher than deeps (37.2%, 1.27 ± 0.51). Elite midfielders, nomadics, and ruckmen recorded higher PLSLOW than deeps (13.5%, 0.65 ± 0.37; 11.7%, 0.55 ± 0.36; and 19.5%, 0.83 ± 0.50, respectively). Subelite midfielders were higher than nomadics, deeps, and ruckmen (14.0%, 1.08 ± 0.30; 31.7%, 2.61 ± 0.42; and 19.9%, 0.81 ± 0.55, respectively), and nomadics and ruckmen were higher than deeps for PL (20.6%, 1.45 ± 0.38; and 17.4%, 0.57 ± 0.55, respectively). Elite midfielders, nomadics, and ruckmen recorded higher PL (7.8%, 0.59 ± 0.29; 12.9%, 0.89 ± 0.25; and 18.0%, 0.67 ± 0.59, respectively) and PLSLOW (9.4%, 0.52 ± 0.30; 11.3%, 0.68 ± 0.25; and 14.1%, 0.84 ± 0.61, respectively) than subelite players. Small-sided games recorded the highest PL and PLSLOW and were the only training drill to equal or exceed the load from matches across positions and playing levels. PL differed between positions, with midfielders the highest, and between playing levels, with elite higher. Differences between matches and training were also evident, with PL from small-sided games equivalent to or higher than matches.

  7. Mathematical model for prediction of pyrolysis and ignition of wood under external heat flux

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The pyrolysis and ignition of combustible materials is an important aspect of the processes taking place in an unwanted fire. A prediction model presented in this paper is to study pyrolysis and ignition time of wood under external heat flux. The solution of the model provides the temperature at each point of the solid and the local solid conversion. And the time to ignition of the wood is predicted with the solution of surface temperature. In general, a good agreement between experimental and theoretical results is obtained.

  8. Heating load of buildings. Room heat from decentralized renewable electricity; Heizlast von Gebaeuden. Raumwaerme aus dezentral erneuerbarem Strom

    Energy Technology Data Exchange (ETDEWEB)

    Hartmann, Frank

    2013-10-15

    If one would like to get the heating load of a building by using peripheral generated electrical energy from photovoltaics or small wind power, one must deal with both the specific building, as well as the heating load, the heating temperature limit and the differentiation of specific heating period for the building. Here, a ground source heat pump with an intelligent energy storage system seems to be the first choice. [German] Moechte man mit dezentral erzeugter elektrischer Energie aus Photovoltaik oder Kleinst-Windkraft die Heizlast eines Gebaeudes besorgen, muss man sich sowohl mit dem spezifischen Gebaeude, als auch mit der Heizlast, der Heizgrenztemperatur und der Differenzierung der spezifischen Heizperiode fuer das Gebaeude auseinandersetzen. Dabei scheint eine erdgekoppelte Waermepumpe mit einem intelligenten Speichersystem die erste Wahl.

  9. Quantitative evaluation of wall heat loads by lost fast ions in the Large Helical Device

    Science.gov (United States)

    Morimoto, Junki; Suzuki, Yasuhiro; Seki, Ryosuke

    2016-10-01

    In fusion plasmas, fast ions are produced by neutral beam injections (NBI), ion cyclotron heating (ICH) and fusion reactions. Some of fast ions are lost from fusion plasmas because of some kinds of drift and instability. These lost fast ions may cause damages on plasma facing components such as divertors and diagnostic instruments in fusion reactors. Therefore, wall heat loads by lost fast ions in the Large Helical Device (LHD) is under investigation. For this purpose, we have been developing the Monte-Carlo code for the quantitative evaluation of wall heat loads based on following the guiding center orbits of fast ions. Using this code, we investigate wall heat loads and hitting points of lost fast ions produced by NBI in LHD. Magnetic field configurations, which depend on beta values, affect orbits of fast ions and wall heat loads. Therefore, the wall heat loads by fast ions in equilibrium magnetic fields including finite beta effect and magnetic islands are quantitatively evaluated. The differences of wall heat loads and particle deposition patterns for cases of the vacuum field and various beta equilibrium fields will be presented at the meeting.

  10. Experimental investigation on heat transfer rate of Co–Mn ferrofluids in external magnetic field

    Directory of Open Access Journals (Sweden)

    Margabandhu M.

    2016-06-01

    Full Text Available Manganese substituted cobalt ferrite (Co1–xMnxFe2O4 with x = 0, 0.3, 0.5, 0.7 and 1 nanopowders were synthesized by chemical coprecipitation method. The synthesized magnetic nanoparticles were investigated by various characterization techniques, such as X-ray diffraction (XRD, vibrating sample magnetometry (VSM, scanning electron microscopy (SEM and thermogravimetric and differential thermal analysis (TG/DTA. The XRD results confirmed the presence of cubic spinel structure of the prepared powders and the average crystallite size of magnetic particles ranging from 23 to 45 nm. The VSM results showed that the magnetic properties varied with an increase in substituted manganese while SEM analysis showed the change in the morphology of obtained magnetic nanoparticles. The TG/DTA analysis indicated the formation of crystalline structure of the synthesized samples. The heat transfer rate was measured in specially prepared magnetic nanofluids (nanoparticles dispersed in carrier fluid transformer oil as a function of time and temperature in presence of external magnetic fields. The experimental analysis indicated enhanced heat transfer rate of the magnetic nanofluids which depended upon the strength of external magnetic field and chemical composition.

  11. Optimal Cooling Load and COP Relationship of a Four-Heat-Reservoir Endoreversible Absorption Refrigeration Cycle

    Directory of Open Access Journals (Sweden)

    Chih Wu

    2004-06-01

    Full Text Available Abstract: On the basis of a four-heat-reservoir endoreversible absorption refrigeration cycle model, another linear heat transfer law [i.e., the heat-flux] is adopted, the fundamental optimal relation between the coefficient of performance (COP and the cooling load, as well as the maximum cooling load and the corresponding COP of the cycle coupled to constant-temperature heat reservoirs are derived by using finite-time thermodynamics or thermodynamic optimization. The optimal distribution of the heat-transfer surface areas is also obtained. Moreover, the effects of the cycle parameters on the COP and the cooling load of the cycle are studied by detailed numerical examples. The results obtained herein are of importance to the optimal design and performance improvement of an absorption refrigeration cycle.

  12. Elastic-Plastic Nonlinear Response of a Space Shuttle External Tank Stringer. Part 2; Thermal and Mechanical Loadings

    Science.gov (United States)

    Knight, Norman F., Jr.; Warren, Jerry E.; Elliott, Kenny B.; Song, Kyongchan; Raju, Ivatury S.

    2012-01-01

    Elastic-plastic, large-deflection nonlinear thermo-mechanical stress analyses are performed for the Space Shuttle external tank s intertank stringers. Detailed threedimensional finite element models are developed and used to investigate the stringer s elastic-plastic response for different thermal and mechanical loading events from assembly through flight. Assembly strains caused by initial installation on an intertank panel are accounted for in the analyses. Thermal loading due to tanking was determined to be the bounding loading event. The cryogenic shrinkage caused by tanking resulted in a rotation of the intertank chord flange towards the center of the intertank, which in turn loaded the intertank stringer feet. The analyses suggest that the strain levels near the first three fasteners remain sufficiently high that a failure may occur. The analyses also confirmed that the installation of radius blocks on the stringer feet ends results in an increase in the stringer capability.

  13. Analysis of the cryogenic system behavior for pulsed heat load in EAST

    Science.gov (United States)

    Hu, L. B.; Zhuang, M.; Zhou, Z. W.; Xia, G. H.

    2014-01-01

    EAST is the first full superconducting fusion device. The plasma is confined by the magnetic fields generated from a large set of superconducting magnets which are made of cable in-conduit conductor (CICC). In operation, these magnets suffer heat loads from thermal and nuclear radiation from the surrounding components and plasma as well as the eddy currents and the AC losses generated within the magnets, together with the heat conduction through supports and the resistive heat generated at the current lead transiting to room temperature. The cryogenic system of our EAST consists of a 2kW/4K helium refrigerator and a distribution system for the cooling of poloidal field (PF) and toroidal field (TF) coils, structures, thermal shields, buslines and current leads. Pulsed heat load is the main difference between the cryogenic system of a full superconducting Tokamak system and other large scale cryogenic systems. The cryogenic system operates in a pulsed heat loads mode requiring the helium refrigerator to remove periodically large heat loads in time. At the same time, the cryogenic system parameters such as helium cooling superconducting magnets, helium refrigerator and helium distribution system are changing. In this paper, the variation range of the parameters of superconducting magnets and refrigerator has been analyzed in the typical plasma discharge mode. The control scheme for the pulsed loads characteristics of the cryogenic system has been proposed, the implementation of which helps to smooth the pulse loads and to improve the stability of the operation of the cryogenic system.

  14. Assessment of Static Heat Loads in the LHC Arc, from the Commissioning of Sector 7-8

    CERN Document Server

    Maglioni, C

    2008-01-01

    This note presents first estimates of the static heat loads in the LHC arc cryostats, evaluated experimentally during the commissioning of sector 7-8 in April 2007. Heat loads to the thermal shielding are estimated from the non-isothermal cooling of the supercritical helium in line E, while heat loads to the 1.9K level of the cold masses are estimated from the internal energy balance during a natural warm-up of the sector in the absence of active cooling. A comparison of the measured heat loads with the budgeted heat loads is then presented and discussed.

  15. Heat Transfer and Impact Load of Steel and Concrete Double Containment

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Tae-Soon; Choi, Choeng-Ryul [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2016-10-15

    A CFD analysis technique was applied. The impact load on the concrete wall by aircraft and thermal heat release rate by steel containment were evaluated. We could confirm the structural role of added structure, and in conclusion, the case of adding cooling water tank to SUS containment vessel could obtain bigger impact load dispersion effect.

  16. Combined impact of transient heat loads and steady-state plasma exposure on tungsten

    Energy Technology Data Exchange (ETDEWEB)

    Huber, Alexander, E-mail: A.Huber@fz-juelich.de [Forschungszentrum Jülich GmbH, Institut für Energie- und Klimaforschung, 52425 Jülich (Germany); Wirtz, Marius; Sergienko, Gennady; Steudel, Isabel [Forschungszentrum Jülich GmbH, Institut für Energie- und Klimaforschung, 52425 Jülich (Germany); Arakcheev, Aleksey; Burdakov, Aleksander [Budker Institute of Nuclear Physics (BINP), Novosibirsk 630090 (Russian Federation); Esser, Hans Guenter; Freisinger, Michaele; Kreter, Arkadi; Linke, Jochen; Linsmeier, Christian; Mertens, Philippe; Möller, Sören; Philipps, Volker; Pintsuk, Gerald; Reinhart, Michael; Schweer, Bernd [Forschungszentrum Jülich GmbH, Institut für Energie- und Klimaforschung, 52425 Jülich (Germany); Shoshin, Andrey [Budker Institute of Nuclear Physics (BINP), Novosibirsk 630090 (Russian Federation); Terra, Alexis; Unterberg, Bernhard [Forschungszentrum Jülich GmbH, Institut für Energie- und Klimaforschung, 52425 Jülich (Germany)

    2015-10-15

    Highlights: • W-samples under combined loading conditions show a lower damage threshold. • The pre-loaded W-samples show a lower damage threshold due to the D- embrittlement. • Pronounced increase of the D retention has been observed during the combined loads. • Enhanced blister formation has been observed under combined loading conditions. - Abstract: Cracking thresholds and crack patterns in tungsten targets have been studied in recent experiments after repetitive ITER-like ELM heat pulses in combination with plasma exposure in PSI-2 (Γ{sub target} = 2.5–4.0 × 10{sup 21} m{sup −2} s{sup −1}, ion energy on surface E{sub ion} = 60 eV, T{sub e} ≈ 10 eV). The heat pulses were simulated by laser irradiation. A Nd:YAG laser with energy per pulse of up to 32 J and a duration of 1 ms at the fundamental wavelength (λ = 1064 nm, repetition rate 0.5 Hz) was used to irradiate ITER-grade W samples with repetitive heat loads. In contrast to pure thermal exposure with a laser beam where the damage threshold under pure heat loads for ITER-grade W lies between 0.38 and 0.76 GW/m{sup 2}, the experiments with pre-loaded W-samples as well as under combined loading conditions show a lower damage threshold of 0.3 GW/m{sup 2}. This is probably due to deuterium embrittlement and/or a higher defect concentration in a region close to the surface due to supersaturation with deuterium. A pronounced increase in the D retention (more than a factor of five) has been observed during the combined transient heat loads and plasma exposure. Enhanced blister formation has been observed under these combined loading conditions.

  17. Diffuse Ceiling Ventilation and the Influence of Room Height and Heat Load Distribution

    DEFF Research Database (Denmark)

    Nielsen, Peter Vilhelm; Vilsbøll, Rasmus W; Liu, Li;

    2015-01-01

    Diffuse ceiling (inlet) ventilation is an air distribution system that supplies air from the entire ceiling surface, giving a low supply velocity. The flow pattern in the room is controlled by the heat sources. The system generates high mixing flow and the air velocities in the room are expected...... with a large room height and it decreases in connection with certain heat load distributions. Room geometries and heat load distributions that are optimal for diffuse ceiling ventilation are discussed. A simplified design procedure is introduced....

  18. Measurements of SCRF cavity dynamic heat load in horizontal test system

    Energy Technology Data Exchange (ETDEWEB)

    DeGraff, B.D.; Bossert, R.J.; Pei, L.; Soyars, W.M.; /Fermilab

    2009-11-01

    The Horizontal Test System (HTS) at Fermilab is currently testing fully assembled, dressed superconducting radio frequency (SCRF) cavities. These cavities are cooled in a bath of superfluid helium at 1.8K. Dissipated RF power from the cavities is a dynamic heat load on the cryogenic system. The magnitude of heat flux from these cavities into the helium is also an important variable for understanding cavity performance. Methods and hardware used to measure this dynamic heat load are presented. Results are presented from several cavity tests and testing accuracy is discussed.

  19. Calorimetric measurement of heat load in full non-inductive LHCD plasmas on TRIAM-1M

    Science.gov (United States)

    Hanada, K.; Shinoda, N.; Sugata, T.; Sasaki, K.; Zushi, H.; Nakamura, K.; Sato, K. N.; Sakamoto, M.; Idei, H.; Hasegawa, M.; Kawasaki, S.; Nakashima, H.; Higashijima, A.; Triam Group

    2007-06-01

    Calorimetric measurements using the temperature increment of cooling-water were carried out to estimate the heat load distribution on the plasma facing components (PFCs) in the limiter discharges on TRIAM-1M. Line averaged electron density, ne, and LH power, PLH, dependences of the heat load on PFCs were measured. The heat load on the limiters was proportional to ne1.5 in the range of ne = 0.2-1.0 × 1019 m-3 and PLH1 in the range of PLH = 0.005-0.09 MW. For PLH > 0.1 MW, the plasma transition to an enhanced current drive (ECD) mode appeared and the ne dependences on the heat load on the limiter moderated. This indicates that the heat flux to scrape-off layer (SOL) region was reduced due to the improvement of the plasma confinement. The up-down asymmetry of the heat load on the vacuum vessel was enhanced in the ECD mode, which may be caused by the increasing of the direct loss of energetic electrons.

  20. Estimation of heat load in waste tanks using average vapor space temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Crowe, R.D.; Kummerer, M.; Postma, A.K.

    1993-12-01

    This report describes a method for estimating the total heat load in a high-level waste tank with passive ventilation. This method relates the total heat load in the tank to the vapor space temperature and the depth of waste in the tank. Q{sub total} = C{sub f} (T{sub vapor space {minus}} T{sub air}) where: C{sub f} = Conversion factor = (R{sub o}k{sub soil}{sup *}area)/(z{sub tank} {minus} z{sub surface}); R{sub o} = Ratio of total heat load to heat out the top of the tank (function of waste height); Area = cross sectional area of the tank; k{sub soil} = thermal conductivity of soil; (z{sub tank} {minus} z{sub surface}) = effective depth of soil covering the top of tank; and (T{sub vapor space} {minus} T{sub air}) = mean temperature difference between vapor space and the ambient air at the surface. Three terms -- depth, area and ratio -- can be developed from geometrical considerations. The temperature difference is measured for each individual tank. The remaining term, the thermal conductivity, is estimated from the time-dependent component of the temperature signals coming from the periodic oscillations in the vapor space temperatures. Finally, using this equation, the total heat load for each of the ferrocyanide Watch List tanks is estimated. This provides a consistent way to rank ferrocyanide tanks according to heat load.

  1. Thermally determining flow and/or heat load distribution in parallel paths

    Energy Technology Data Exchange (ETDEWEB)

    Chainer, Timothy J.; Iyengar, Madhusudan K.; Parida, Pritish R.

    2017-08-01

    A method including obtaining calibration data for at least one sub-component in a heat transfer assembly, wherein the calibration data comprises at least one indication of coolant flow rate through the sub-component for a given surface temperature delta of the sub-component and a given heat load into said sub-component, determining a measured heat load into the sub-component, determining a measured surface temperature delta of the sub-component, and determining a coolant flow distribution in a first flow path comprising the sub-component from the calibration data according to the measured heat load and the measured surface temperature delta of the sub-component.

  2. Thermally determining flow and/or heat load distribution in parallel paths

    Energy Technology Data Exchange (ETDEWEB)

    Chainer, Timothy J.; Iyengar, Madhusudan K.; Parida, Pritish R.

    2016-12-13

    A method including obtaining calibration data for at least one sub-component in a heat transfer assembly, wherein the calibration data comprises at least one indication of coolant flow rate through the sub-component for a given surface temperature delta of the sub-component and a given heat load into said sub-component, determining a measured heat load into the sub-component, determining a measured surface temperature delta of the sub-component, and determining a coolant flow distribution in a first flow path comprising the sub-component from the calibration data according to the measured heat load and the measured surface temperature delta of the sub-component.

  3. Experimental study of plasma energy transfer and material erosion under ELM-like heat loads

    Energy Technology Data Exchange (ETDEWEB)

    Garkusha, I.E., E-mail: garkusha@ipp.kharkov.u [Institute of Plasma Physics of the NSC KIPT, Akademicheskaya 1, 61108 Kharkov (Ukraine); Makhlaj, V.A.; Chebotarev, V.V. [Institute of Plasma Physics of the NSC KIPT, Akademicheskaya 1, 61108 Kharkov (Ukraine); Landman, I. [Forschungszentrum Karlsruhe, IHM, 76021 Karlsruhe (Germany); Tereshin, V.I.; Aksenov, N.N.; Bandura, A.N. [Institute of Plasma Physics of the NSC KIPT, Akademicheskaya 1, 61108 Kharkov (Ukraine)

    2009-06-15

    Main features of plasma-surface interaction and energy transfer to tokamak plasma facing components are studied at different heat loads in ELM simulation experiments with the plasma gun QSPA Kh-50. Repetitive plasma exposures of tungsten, graphite and different combined W-C targets were performed at the pulse duration of 0.25 ms and the heat loads varied in the range 0.2-2.5 MJ/m{sup 2}. The onset of vapor shield in front of the surface was investigated. The evaporation is immediately followed by a saturation of surface heat load if further increasing the impact energy. The presence of graphite essentially decreases the heat flux to the nearby tungsten surface, which is due to the carbon vapor shield. Droplet splashing at the tungsten surface and formation of hot spots on the graphite surface are discussed.

  4. Diffusion-controlled startup of a gas-loaded liquid-metal heat pipe

    Science.gov (United States)

    Ponnappan, R.; Boehman, L. I.; Mahefkey, E. T.

    1990-07-01

    Liquid-metal heat pipes have exhibited difficulties starting up from a frozen-state. Inert gas loading is a possible solution to the frozen-state startup problem. The present study deals with the diffusion-controlled startup analysis and testing of an argon-loaded, 2-m-long, stainless steel-sodium heat pipe of the double-walled type with artery channel and long adiabatic section. A two-dimensional, quasi-steady state, binary vapor-gas diffusion model determined the energy transport rate of vapor at the diffusion front. The analytical solution to the diffusion problem provided the vapor flux, which in turn was used in the one-dimensional transient thermal model of the heat pipe to predict the time rate-of-change of temperature and position of the hot front. The experimental test results successfully demonstrated the startup of a gas-loaded sodium heat pipe and validated the diffusion model of the startup.

  5. Design and operations of load-tolerant external conjugate-T matching system for the A2 ICRH antennas at JET

    CERN Document Server

    Monakhov, I; Blackman, T; Dowson, S; Durodie, F; Jacquet, P; Lehmann, J; Mayoral, M-L; Nightingale, M P S; Noble, C; Sheikh, H; Vrancken, M; Walden, A; Whitehurst, A; Wooldridge, E; contributors, JET-EFDA

    2013-01-01

    A load-tolerant External Conjugate-T (ECT) impedance matching system for two A2 Ion Cyclotron Resonance Heating (ICRH) antennas has been successfully put into operation at JET. The system allows continuous injection of the RF power into plasma in the presence of strong antenna loading perturbations caused by Edge Localized Modes (ELMs). Reliable ECT performance has been demonstrated under a variety of antenna loading conditions including H-mode plasmas with Radial Outer Gaps (ROG) in the range of 4-14 cm. The high resilience to ELMs predicted during the circuit simulations has been fully confirmed experimentally. Dedicated arc detection techniques and real-time matching algorithms have been developed as a part of the ECT project. The new Advanced Wave Amplitude Comparison System (AWACS) has proven highly efficient in detection of arcs both between and during ELMs. The ECT system has allowed the delivery of up to 4 MW of RF power without trips into plasmas with Type-I ELMs. Together with the 3dB system and the...

  6. Optimum load distribution between heat sources based on the Cournot model

    Science.gov (United States)

    Penkovskii, A. V.; Stennikov, V. A.; Khamisov, O. V.

    2015-08-01

    One of the widespread models of the heat supply of consumers, which is represented in the "Single buyer" format, is considered. The methodological base proposed for its description and investigation presents the use of principles of the theory of games, basic propositions of microeconomics, and models and methods of the theory of hydraulic circuits. The original mathematical model of the heat supply system operating under conditions of the "Single buyer" organizational structure provides the derivation of a solution satisfying the market Nash equilibrium. The distinctive feature of the developed mathematical model is that, along with problems solved traditionally within the bounds of bilateral relations of heat energy sources-heat consumer, it considers a network component with its inherent physicotechnical properties of the heat network and business factors connected with costs of the production and transportation of heat energy. This approach gives the possibility to determine optimum levels of load of heat energy sources. These levels provide the given heat energy demand of consumers subject to the maximum profit earning of heat energy sources and the fulfillment of conditions for formation of minimum heat network costs for a specified time. The practical realization of the search of market equilibrium is considered by the example of a heat supply system with two heat energy sources operating on integrated heat networks. The mathematical approach to the solution search is represented in the graphical form and illustrates computations based on the stepwise iteration procedure for optimization of levels of loading of heat energy sources (groping procedure by Cournot) with the corresponding computation of the heat energy price for consumers.

  7. Impact of External Pressure on the Heat Transfer Coefficient during Solidification of Al-A356 Alloy

    DEFF Research Database (Denmark)

    Jabbari, Masoud; Ilkhchy, A.Fardi; Moumani, E.

    In this paper the interfacial heat transfer coefficient (IHTC) is correlated to applied external pressure, in which IHTC at the interface between A356 aluminum alloy and metallic mold during the solidification of the casting under different pressures were obtained using the Inverse Heat Conduction...... Problem (IHCP) method. The method covers the expedient of comparing theoretical and experimental thermal histories. Temperature profiles obtained from thermocouples were used in a finite difference heat flow program to estimate the transient heat transfer coefficients. The new simple formula was presented...

  8. Comparison of ELM heat loads in snowflake and standard divertors

    Energy Technology Data Exchange (ETDEWEB)

    Rognlien, T D; Cohen, R H; Ryutov, D D; Umansky, M V

    2012-05-08

    An analysis is given of the impact of the tokamak divertor magnetic structure on the temporal and spatial divertor heat flux from edge localized modes (ELMs). Two configurations are studied: the standard divertor where the poloidal magnetic field (B{sub p}) varies linearly with distance (r) from the magnetic null and the snowflake where B{sub p} varies quadratrically with r. Both one and two-dimensional models are used to analyze the effect of the longer magnetic field length between the midplane and the divertor plate for the snowflake that causes a temporal dilation of the ELM divertor heat flux. A second effect discussed is the appearance of a broad region near the null point where the poloidal plasma beta can substantially exceed unity, especially for the snowflake configuration during the ELM; such a condition is likely to drive additional radial ELM transport.

  9. Testing and analysis of load-side immersed heat exchangers for solar domestic hot water systems

    Energy Technology Data Exchange (ETDEWEB)

    Farrington, R.B.; Bingham, C.E.

    1987-10-01

    This report describes work to determine the performance of load-side heat exchangers for use in residential solar domestic hot water systems. We measured the performance of four heat exchangers: a smooth coil and a finned coil having heat transfer areas of 2.5 m/sup 2/ (26 ft/sup 2/) and those having areas of 1.7 m/sup 2/ (19 ft/sup 2/). A numerical model using the thermal network program MITAS was constructed, and results were compared to the experimental results. Research showed a smooth coil with only 70% of the surface area of a finned coil performed better than the finned coil. Also, load-side heat exchangers can maintain and enhance stratification in storage tanks, permitting the use of control strategies that take advantage of stratified storage tanks to increase system performance. The analytical model, which agreed reasonably well with the experimental results, was used to vary heat exchanger flow rate and area and initial tank temperature for both a smooth- and a finned-coil heat exchanger. Increasing the heat exchanger flow rate and area results in higher heat transfer rates but not necessarily optimal performance. Lower initial tank temperatures resulted in reduced tank stratification. The smooth heat exchanger outperformed the finned heat exchanger with the same outside surface area. 15 refs., 37 figs., 9 tabs.

  10. Response of NSTX liquid lithium divertor to high heat loads

    Energy Technology Data Exchange (ETDEWEB)

    Abrams, T., E-mail: tabrams@pppl.gov [Princeton Plasma Physics Laboratory, Princeton, NJ 08543 (United States); Jaworski, M.A. [Princeton Plasma Physics Laboratory, Princeton, NJ 08543 (United States); Kallman, J. [Lawrence Livermore National Laboratory, Livermore, CA 94550 (United States); Kaita, R. [Princeton Plasma Physics Laboratory, Princeton, NJ 08543 (United States); Foley, E.L. [Nova Photonics, Inc., Princeton, NJ 08543 (United States); Gray, T.K. [Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Kugel, H. [Princeton Plasma Physics Laboratory, Princeton, NJ 08543 (United States); Levinton, F. [Nova Photonics, Inc., Princeton, NJ 08543 (United States); McLean, A.G. [Lawrence Livermore National Laboratory, Livermore, CA 94550 (United States); Skinner, C.H. [Princeton Plasma Physics Laboratory, Princeton, NJ 08543 (United States)

    2013-07-15

    Samples of the NSTX Liquid Lithium Divertor (LLD) with and without an evaporative Li coating were directly exposed to a neutral beam ex-situ at a power of ∼1.5 MW/m{sup 2} for 1–3 s. Measurements of front face and bulk sample temperature were obtained. Predictions of temperature evolution were derived from a 1D heat flux model. No macroscopic damage occurred when the “bare” sample was exposed to the beam but microscopic changes to the surface were observed. The Li-coated sample developed a lithium hydroxide (LiOH) coating, which did not change even when the front face temperature exceeded the pure Li melting point. These results are consistent with the lack of damage to the LLD surface and imply that heating alone may not expose pure liquid Li if the melting point of surface impurities is not exceeded. This suggests that flow and heat are needed for future PFCs requiring a liquid Li surface.

  11. Deformation pathways and breakup modes in acoustically levitated bicomponent droplets under external heating

    Science.gov (United States)

    Pathak, Binita; Basu, Saptarshi

    2016-03-01

    Controlled breakup of droplets using heat or acoustics is pivotal in applications such as pharmaceutics, nanoparticle production, and combustion. In the current work we have identified distinct thermal acoustics-induced deformation regimes (ligaments and bubbles) and breakup dynamics in externally heated acoustically levitated bicomponent (benzene-dodecane) droplets with a wide variation in volatility of the two components (benzene is significantly more volatile than dodecane). We showcase the physical mechanism and universal behavior of droplet surface caving in leading to the inception and growth of ligaments. The caving of the top surface is governed by a balance between the acoustic pressure field and the restrictive surface tension of the droplet. The universal collapse of caving profiles for different benzene concentration (growth. Subsequent ligament breakup is primarily Rayleigh-Plateau type. The breakup mode shifts to diffusional entrapment-induced boiling with an increase in concentration of the volatile component (benzene >70 % by volume). The findings are portable to any similar bicomponent systems with differential volatility.

  12. AUTOMATIC CONTROL SYSTEM OF HEAT PUMP STATION GAS COOLER AT THE WIDE RANGE OF HEAT LOAD

    Directory of Open Access Journals (Sweden)

    Juravleov A.A.

    2008-08-01

    Full Text Available There is examined the structure the of control system of gas cooler of heat pump station, which uses the carbon dioxide as the working fluid in the transctitical thermodynamical cycle. It is analiyed the structure of the complex: heat pump station – district heating system.

  13. Heat load tests of superconducting magnets vibrated electromagnetically for the Maglev train

    Science.gov (United States)

    Ohmori, J.; Nakao, H.; Yamashita, T.; Sanada, Y.; Shudou, M.; Kawai, M.; Fujita, M.; Terai, M.; Miura, A.

    Superconducting magnets on Maglev trains vibrate due to harmonic ripples of electromagnetic flux generated by ground coils. Heat load caused by vibration in the magnet amounted to several tens of watts in the electromagnetic vibration test. This was mainly because a.c. loss was induced in the helium vessel housing the superconducting coil, due to relative vibration between the aluminium thermal shield and the coil. The heat load caused by vibration should be strictly restricted to less than 4W due to limited cryogenic refrigeration capacity. The heat load was tested using electromagnetic flux ripples for a superconducting magnet model of one coil which corresponds to 1/4 of an actual magnet. The flux ripples simulated the 6th harmonic of the actual ground levitation coil. Some ideas to reduce the heat load were tried for the magnet model, such as applying high resistance thermal radiation shielding, increasing rigidity of the vacuum vessel, and using high purity copper plating on the helium vessel. These ideas proved effective, and the maximum heat load due to vibration was held to less than 4 W per magnet for the one coil magnet model.

  14. Characterization of heat loads from mitigated and unmitigated vertical displacement events in DIII-D

    Science.gov (United States)

    Hollmann, E. M.; Commaux, N.; Eidietis, N. W.; Humphreys, D. A.; Jernigan, T. J.; Lasnier, C. J.; Moyer, R. A.; Pitts, R. A.; Sugihara, M.; Strait, E. J.; Watkins, J.; Wesley, J. C.

    2013-06-01

    Experiments have been conducted on the DIII-D tokamak to study the distribution and repeatability of heat loads and vessel currents resulting from vertical displacement events (VDEs). For unmitigated VDEs, the radiated power fraction appears to be of order 50%, with the remaining power dominantly conducted to the vessel walls. Shot-to-shot scatter in heat loads measured at one toroidal location is not large (<±50%), suggesting that toroidal asymmetries in conducted heat loads are not large. Conducted heat loads are clearly observed during the current quench (CQ) of both mitigated and unmitigated disruptions. Significant poloidal asymmetries in heat loads and radiated power are often observed in the experiments but are not yet understood. Energy dissipated resistively in the conducting walls during the CQ appears to be small (<5%). The mitigating effect of neon massive gas injection (MGI) as a function of MGI trigger delay has also been studied. Improved mitigation is observed as the MGI trigger delay is decreased. For sufficiently early MGI mitigation, close to 100% radiated energy and a reduction of roughly a factor 2 in vessel forces is achieved.

  15. Characterization of heat loads from mitigated and unmitigated vertical displacement events in DIII-D

    Energy Technology Data Exchange (ETDEWEB)

    Hollmann, E. M.; Moyer, R. A. [University of California-San Diego, La Jolla, California 92093 (United States); Commaux, N.; Jernigan, T. J. [Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States); Eidietis, N. W.; Humphreys, D. A.; Strait, E. J.; Wesley, J. C. [General Atomics, San Diego, California 92186 (United States); Lasnier, C. J. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Pitts, R. A.; Sugihara, M. [ITER Organization, Route de Vinon sur Verdon, 13115 St Paul Lez Durance (France); Watkins, J. [Sandia National Laboratory, Albuquerque, New Mexico 87185 (United States)

    2013-06-15

    Experiments have been conducted on the DIII-D tokamak to study the distribution and repeatability of heat loads and vessel currents resulting from vertical displacement events (VDEs). For unmitigated VDEs, the radiated power fraction appears to be of order 50%, with the remaining power dominantly conducted to the vessel walls. Shot-to-shot scatter in heat loads measured at one toroidal location is not large (<±50%), suggesting that toroidal asymmetries in conducted heat loads are not large. Conducted heat loads are clearly observed during the current quench (CQ) of both mitigated and unmitigated disruptions. Significant poloidal asymmetries in heat loads and radiated power are often observed in the experiments but are not yet understood. Energy dissipated resistively in the conducting walls during the CQ appears to be small (<5%). The mitigating effect of neon massive gas injection (MGI) as a function of MGI trigger delay has also been studied. Improved mitigation is observed as the MGI trigger delay is decreased. For sufficiently early MGI mitigation, close to 100% radiated energy and a reduction of roughly a factor 2 in vessel forces is achieved.

  16. Specifics of heat and mass transfer in spherical dimples under the effect of external factors

    Science.gov (United States)

    Shchukin, A. V.; Il'inkov, A. V.; Takmovtsev, V. V.; Khabibullin, I. I.

    2017-06-01

    The specifics are examined of heat transfer enhancement with spherical dimples under the effect of factors important for practice and characteristic of cooling systems of gas-turbine engines and power units. This experimental investigation deals with the effect of the following factors on the flow in a channel with hemispherical dimples: continuous air swirl in an annulus with dimples on its concave wall, dimples on the convex or concave wall of a curved rectangular channel, imposition of regular velocity fluctuations on the external flow in a straight rectangular channel, and adverse or favorable pressure gradient along the flow direction. The flow is turbulent. Reynolds numbers based on the channel hydraulic diameter are on the order of 104. Results of the investigation of a model of a two-cavity diffuser dimple proposed by the authors are presented. It has been found that results for channels with spherical dimples and for smooth channels differ not only quantitatively but also qualitatively. Thus, if the effect of centrifugal mass forces on convex and concave surfaces with hemispherical dimples and in a smooth channel is almost the same (quantitative and qualitative indicators are identical), the pressure gradient in the flow direction brings about the drastically opposite results. At the same time, the quantitative contribution to a change in heat transfer in hemispherical dimples is different and depends on the impact type. The results are discussed with the use of physical models created on the basis of the results of flow visualization studies and data on the turbulence intensity, pressure coefficient, etc. Results of the investigations suggest that application of spherical dimples under nonstandard conditions requires the calculated heat transfer to be corrected to account for one or another effect.

  17. Numerical analysis of convective drying of a moist object with combined internal and external heat and mass transfer

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Donghyun; Son, Gihun [Sogang University, Seoul (Korea, Republic of); Kim, Sungil [Korea Institute of Energy Research, Daejeon (Korea, Republic of)

    2016-02-15

    A numerical approach is developed for computing convective drying of a moist object. The conservation equations of mass, momentum, energy and moisture in the internal and external regions of an object are solved with the coupled heat and mass transfer conditions on the object surface, including the effect of evaporation. A numerical approach is applied to predict the internal and external temperature and moisture distributions during the convective drying with variations in the initial moisture content and the water activity. The numerical results show that the water activity is an important parameter for determining the drying rate pattern and the analogy between the heat and mass transfer on the object surface.

  18. Heat Loads Due to Small Penetrations in Multilayer Insulation Blankets

    Science.gov (United States)

    Johnson, W. L.; Heckle, K. W.; Fesmire, J. E.

    2017-01-01

    The main penetrations (supports and piping) through multilayer insulation systems for cryogenic tanks have been previously addressed by heat flow measurements. Smaller penetrations due to fasteners and attachments are now experimentally investigated. The use of small pins or plastic garment tag fasteners to each the handling and construction of multilayer insulation (MLI) blankets goes back many years. While it has long been understood that penetrations and other discontinuities degrade the performance of the MLI blanket, quantification of this degradation has generally been lumped into gross performance multipliers (often called degradation factors or scale factors). Small penetrations contribute both solid conduction and radiation heat transfer paths through the blanket. The conduction is down the stem of the structural element itself while the radiation is through the hole formed during installation of the pin or fastener. Analytical models were developed in conjunction with MLI perforation theory and Fouriers Law. Results of the analytical models are compared to experimental testing performed on a 10 layer MLI blanket with approximately 50 small plastic pins penetrating the test specimen. The pins were installed at 76-mm spacing inches in both directions to minimize the compounding of thermal effects due to localized compression or lateral heat transfer. The testing was performed using a liquid nitrogen boil-off calorimeter (Cryostat-100) with the standard boundary temperatures of 293 K and 78 K. Results show that the added radiation through the holes is much more significant than the conduction down the fastener. The results are shown to be in agreement with radiation theory for perforated films.

  19. Erosion of newly developed CFCs and Be under disruption heat loads

    Science.gov (United States)

    Nakamura, K.; Akiba, M.; Araki, M.; Dairaku, M.; Sato, K.; Suzuki, S.; Yokoyama, K.; Linke, J.; Duwe, R.; Bolt, H.; Roedig, M.

    1996-10-01

    An evaluation of the erosion under disruption heat loads is very important to the lifetime prediction of divertor armour tiles of next fusion devices such as ITER. In particular, erosion data on CFCs (carbon fiber reinforced composites) and beryllium (Be) as the armour materials is urgently required in the ITER design. For CFCs, high heat flux experiments on the newly developed CFCs with high thermal conductivity have been performed under the heat flux of around 800-2000 MW/m 2 and the pulse length of 2-5 ms in JAERI electron beam irradiation systems (JEBIS). As a result, the weight losses of B 4C doped CFCs after heating were almost same to those of the non doped CFC up to 5 wt% boron content. For Be, we have carried out our first disruption experiments on S65/C grade Be specimens in the Juelich divertor test facility in hot cells (JUDITH) facility as a frame work of the J—EU collaboration. The heating conditions were heat loads of 1250-5000 MW/m 2 for 2-8 ms, and the heated area was 3 × 3 mm 2. As a result, the protuberances of the heated area of Be were observed under the lower heat flux.

  20. Considerable different frequency dependence of dynamic tensile modulus between self-heating (Joule heat) and external heating for polymer--nickel-coated carbon fiber composites.

    Science.gov (United States)

    Zhang, Rong; Bin, Yuezhen; Dong, Enyuan; Matsuo, Masaru

    2014-06-26

    Dynamic tensile moduli of polyethylene--nickel-coated carbon fiber (NiCF) composites with 10 and 4 vol % NiCF contents under electrical field were measured by a homemade instrument in the frequency range of 100--0.01 Hz. The drastic descent of the storage modulus of the composite with 10 vol % was verified in lower frequency range with elevating surface temperature (T(s)) by self-heating (Joule heat). The composite was cut when T(s) was beyond 108 °C. On the other hand, the measurement of the composite with 4 vol % beyond 88 °C was impossible, since T(s) did not elevate because of the disruption of current networks. Incidentally, the dynamic tensile moduli by external heating could be measured up to 130 and 115 °C for 10 and 4 vol %, respectively, but the two composites could be elongated beyond the above temperatures. Such different properties were analyzed in terms of crystal dispersions, electrical treeing, and thermal fluctuation-induced tunneling effect.

  1. Modeling of ribosome dynamics on a ds-mRNA under an external load

    Science.gov (United States)

    Shakiba, Bahareh; Dayeri, Maryam; Mohammad-Rafiee, Farshid

    2016-07-01

    Protein molecules in cells are synthesized by macromolecular machines called ribosomes. According to the recent experimental data, we reduce the complexity of the ribosome and propose a model to express its activity in six main states. Using our model, we study the translation rate in different biological relevant situations in the presence of external force and the translation through the RNA double stranded region in the absence or presence of the external force. In the present study, we give a quantitative theory for translation rate and show that the ribosome behaves more like a Brownian Ratchet motor. Our findings could shed some light on understanding behaviors of the ribosome in biological conditions.

  2. Modeling of Ribosome Dynamics on a ds-mRNA under an External Load

    CERN Document Server

    Shakiba, Bahareh; Mohammad-Rafiee, Farshid

    2016-01-01

    Protein molecules in cells are synthesized by macromolecular machines called ribosomes. According to recent experimental data, we reduce the complexity of the ribosome and propose a model to express its activity in six main states. Using our model, we study the translation rate in different biological relevant situations in the presence of external force, and translation through the RNA double stranded region in the absence or presence of the external force. In the present study, we give a quantitative theory for translation rate and show that the ribosome behaves more like a Brownian Ratchet motor. Our findings could shed some light on understanding behaviors of the ribosome in biological conditions.

  3. Full-scale testing of leakage of blast waves inside a partially vented room exposed to external air blast loading

    Science.gov (United States)

    Codina, R.; Ambrosini, D.

    2017-06-01

    For the last few decades, the effects of blast loading on structures have been studied by many researchers around the world. Explosions can be caused by events such as industrial accidents, military conflicts or terrorist attacks. Urban centers have been prone to various threats including car bombs, suicide attacks, and improvised explosive devices. Partially vented constructions subjected to external blast loading represent an important topic in protective engineering. The assessment of blast survivability inside structures and the development of design provisions with respect to internal elements require the study of the propagation and leakage of blast waves inside buildings. In this paper, full-scale tests are performed to study the effects of the leakage of blast waves inside a partially vented room that is subjected to different external blast loadings. The results obtained may be useful for proving the validity of different methods of calculation, both empirical and numerical. Moreover, the experimental results are compared with those computed using the empirical curves of the US Defense report/manual UFC 3-340. Finally, results of the dynamic response of the front masonry wall are presented in terms of accelerations and an iso-damage diagram.

  4. Simulation of electron-cloud heat load for the cold arcs of the Large Hadron Collider

    CERN Document Server

    Maury Cuna, Humberto; Rumolo, Giovanni; Zimmermann, Frank

    2013-01-01

    The heat load due to the electron cloud in the Large Hadron Collider (LHC) cold arcs is a concern for its performance near and beyond nominal beam current. We report the results of simulation studies, which examine the electron-cloud induced heat load for different values of low-energy electron reflectivity and secondary emission yield at injection energy, as well as at beam energies of 4 TeV and 7 TeV, for two different bunch spacing: 25 ns and 50 ns. Benchmarking the simulations against heat-load observations at different beam energies and bunch spacings allows an estimate of the secondary emission yield in the cold arcs of the LHC and of its evolution as a function of time.

  5. Long-Haul Truck Sleeper Heating Load Reduction Package for Rest Period Idling

    Energy Technology Data Exchange (ETDEWEB)

    Lustbader, Jason Aaron; Kekelia, Bidzina; Tomerlin, Jeff; Kreutzer, Cory J.; Yeakel, Skip; Adelman, Steven; Luo, Zhiming; Zehme, John

    2016-04-05

    Annual fuel use for sleeper cab truck rest period idling is estimated at 667 million gallons in the United States, or 6.8% of long-haul truck fuel use. Truck idling during a rest period represents zero freight efficiency and is largely done to supply accessory power for climate conditioning of the cab. The National Renewable Energy Laboratory's CoolCab project aims to reduce heating, ventilating, and air conditioning (HVAC) loads and resulting fuel use from rest period idling by working closely with industry to design efficient long-haul truck thermal management systems while maintaining occupant comfort. Enhancing the thermal performance of cab/sleepers will enable smaller, lighter, and more cost-effective idle reduction solutions. In addition, if the fuel savings provide a one- to three-year payback period, fleet owners will be economically motivated to incorporate them. For candidate idle reduction technologies to be implemented by original equipment manufacturers and fleets, their effectiveness must be quantified. To address this need, several promising candidate technologies were evaluated through experimentation and modeling to determine their effectiveness in reducing rest period HVAC loads. Load reduction strategies were grouped into the focus areas of solar envelope, occupant environment, conductive pathways, and efficient equipment. Technologies in each of these focus areas were investigated in collaboration with industry partners. The most promising of these technologies were then combined with the goal of exceeding a 30% reduction in HVAC loads. These technologies included 'ultra-white' paint, advanced insulation, and advanced curtain design. Previous testing showed more than a 35.7% reduction in air conditioning loads. This paper describes the overall heat transfer coefficient testing of this advanced load reduction technology package that showed more than a 43% reduction in heating load. Adding an additional layer of advanced insulation

  6. Long-Haul Truck Sleeper Heating Load Reduction Package for Rest Period Idling: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Lustbader, Jason; Kekelia, Bidzina; Tomerlin, Jeff; Kreutzer, Cory; Adelman, Steve; Yeakel, Skip; Luo, Zhiming; Zehme, John

    2016-03-24

    Annual fuel use for sleeper cab truck rest period idling is estimated at 667 million gallons in the United States, or 6.8% of long-haul truck fuel use. Truck idling during a rest period represents zero freight efficiency and is largely done to supply accessory power for climate conditioning of the cab. The National Renewable Energy Laboratory's CoolCab project aims to reduce heating, ventilating, and air conditioning (HVAC) loads and resulting fuel use from rest period idling by working closely with industry to design efficient long-haul truck thermal management systems while maintaining occupant comfort. Enhancing the thermal performance of cab/sleepers will enable smaller, lighter, and more cost-effective idle reduction solutions. In addition, if the fuel savings provide a one- to three-year payback period, fleet owners will be economically motivated to incorporate them. For candidate idle reduction technologies to be implemented by original equipment manufacturers and fleets, their effectiveness must be quantified. To address this need, several promising candidate technologies were evaluated through experimentation and modeling to determine their effectiveness in reducing rest period HVAC loads. Load reduction strategies were grouped into the focus areas of solar envelope, occupant environment, conductive pathways, and efficient equipment. Technologies in each of these focus areas were investigated in collaboration with industry partners. The most promising of these technologies were then combined with the goal of exceeding a 30% reduction in HVAC loads. These technologies included 'ultra-white' paint, advanced insulation, and advanced curtain design. Previous testing showed more than a 35.7% reduction in air conditioning loads. This paper describes the overall heat transfer coefficient testing of this advanced load reduction technology package that showed more than a 43% reduction in heating load. Adding an additional layer of advanced insulation

  7. Long-Haul Truck Sleeper Heating Load Reduction Package for Rest Period Idling

    Energy Technology Data Exchange (ETDEWEB)

    Lustbader, Jason; Kekelia, Bidzina; Tomerlin, Jeff; Kreutzer, Cory; Adelman, Steve; Yeakel, Skip; Luo, Zhiming; Zehme, John

    2016-06-01

    Annual fuel use for sleeper cab truck rest period idling is estimated at 667 million gallons in the United States, or 6.8% of long-haul truck fuel use. Truck idling during a rest period represents zero freight efficiency and is largely done to supply accessory power for climate conditioning of the cab. The National Renewable Energy Laboratory's CoolCab project aims to reduce heating, ventilating, and air conditioning (HVAC) loads and resulting fuel use from rest period idling by working closely with industry to design efficient long-haul truck thermal management systems while maintaining occupant comfort. Enhancing the thermal performance of cab/sleepers will enable smaller, lighter, and more cost-effective idle reduction solutions. In addition, if the fuel savings provide a one- to three-year payback period, fleet owners will be economically motivated to incorporate them. For candidate idle reduction technologies to be implemented by original equipment manufacturers and fleets, their effectiveness must be quantified. To address this need, several promising candidate technologies were evaluated through experimentation and modeling to determine their effectiveness in reducing rest period HVAC loads. Load reduction strategies were grouped into the focus areas of solar envelope, occupant environment, conductive pathways, and efficient equipment. Technologies in each of these focus areas were investigated in collaboration with industry partners. The most promising of these technologies were then combined with the goal of exceeding a 30% reduction in HVAC loads. These technologies included 'ultra-white' paint, advanced insulation, and advanced curtain design. Previous testing showed more than a 35.7% reduction in air conditioning loads. This paper describes the overall heat transfer coefficient testing of this advanced load reduction technology package that showed more than a 43% reduction in heating load. Adding an additional layer of advanced insulation

  8. Value analysis of district heating system with gas-fired peak load boiler in secondary network

    Institute of Scientific and Technical Information of China (English)

    郑雪晶; 穆振英

    2009-01-01

    In district heating(DH) system with gas-fired peak load regulating boiler in the secondary network,by prolonging run time of base load plants under rated condition,the mean energy efficiency could be increased. The fuels of the system,including coal and gas,would cause different environmental impacts. Meanwhile,the reliability of the heating networks would be changed because the peak load regulating boiler could work as a standby heat source. A model for assessment of heating system was established by value analysis to optimize this kind of system. Energy consumption,greenhouse gas emission,pollution emission and system reliability were selected as functional assessment indexes in the model. Weights of each function were determined by analytical hierarchy process (AHP) and experts consultation. Life cycle cost was used as the cost in the model. A real case as an example was discussed to obtain the optimal base load ratio. The result shows that the optimal base load ratio of the case is 0.77.

  9. Heat load of a GaAs photocathode in an SRF electron gun

    Institute of Scientific and Technical Information of China (English)

    WANG Er-Dong; ZHAO Kui; J(o)rg Kewisch; Ilan Ben-Zvi; Andrew Burrill; Trivini Rao; WU Qiong; Animesh Jain; Ramesh Gupta; Doug Holmes

    2011-01-01

    A great deal of effort has been made over the last decades to develop a better polarized electron source for high energy physics. Several laboratories operate DC guns with a gallium arsenide photocathode, which yield a highly polarized electron beam. However, the beam's emittance might well be improved by using a superconducting radio frequency (SRF) electron gun, which delivers beams of a higher brightness than that from DC guns because the field gradient at the cathode is higher. SRF guns with metal and CsTe cathodes have been tested successfully. To produce polarized electrons, a Gallium-Arsenide photo-cathode must be used: an experiment to do so in a superconducting RF gun is under way at BNL. Since a bulk gallium arsenide (GaAs) photocathode is normal conducting, a problem arises from the heat load stemming from the cathode. We present our measurements of the electrical resistance of GaAs at cryogenic temperatures, a prediction of the heat load and verification by measuring the quality factor of the gun with and without the cathode at 2 K. We simulate heat generation and flow from the GaAs cathode using the ANSYS program. By following the findings with the heat load model, we designed and fabricated a new cathode holder (plug) to decrease the heat load from GaAs.

  10. Simulation of Be armour cracking under ITER-like transient heat loads [in press

    OpenAIRE

    Pestchanyi, S.; Spilker, B.; Bazylev, B.

    2016-01-01

    Simulation of beryllium cracking under action of multiple severe surface heatings has been performed using the PEGASUS-3D code and verified by experiments in the JUDITH 1 facility. Analysis of the results has revealed beryllium thermo conductivity degradation under action of repetitive pulsed heat load due to accumulation of the cracks in the surface layer. Thermo conductivity degradation is found to be at least 4 times after 100 pulses in JUDITH 1 facility. An analytical model for the Be cra...

  11. Simulation of Be armour cracking under ITER-like transient heat loads

    OpenAIRE

    Pestchanyi, S.; Spilker, B.; Bazylev, B

    2016-01-01

    Simulation of beryllium cracking under action of multiple severe surface heatings has been performed using the PEGASUS-3D code and verified by experiments in the JUDITH 1 facility. Analysis of the results has revealed beryllium thermo conductivity degradation under action of repetitive pulsed heat load due to accumulation of the cracks in the surface layer. Thermo conductivity degradation is found to be at least 4 times after 100 pulses in JUDITH 1 facility. An analytical model for the Be cra...

  12. Effect of particle loading on heat transfer enhancement in a gas-solid suspension cross flow

    Institute of Scientific and Technical Information of China (English)

    周劲松; 骆仲泱; 高翔; 倪明江; 岑可法

    2002-01-01

    Heat transfer between gas-solid multiphase flow and tubes occurs in m a ny industry processes, such as circulating fluidized bed process, pneumatic conv eying process, chemical process, drying process, etc. This paper focuses on the influence of the presence of particles on the heat transfer between a tube and g as-solid suspension. The presence of particles causes positive enhancement of h e at transfer in the case of high solid loading ratio, but heat transfer reduction has been found for in the case of very low solid loading ratio (Ms of les s than 0.05 kg/kg). A useful correlation incorporating solid loading ratio, particle s ize and flow Reynolds number was derived from experimental data. In addition, th e k-ε two-equation model and the Fluctuation-Spectrum- Random-Trajecto ry Model ( FSRT Model) are used to simulate the flow field and heat transfer of the gas-ph a se and the solid-phase, respectively. Through coupling of the two phases the mo d el can predict the local and total heat transfer characteristics of tube in gas - solid cross flow. For the total heat transfer enhancement due to particles loadi ng the model predictions agreed well with experimental data.

  13. Estimation of the Unsteady Aerodynamic Load on Space Shuttle External Tank Protuberances from a Component Wind Tunnel Test

    Science.gov (United States)

    Panda, Jayatana; Martin, Fred W.; Sutliff, Daniel L.

    2008-01-01

    At the wake of the Columbia (STS-107) accident it was decided to remove the Protuberance Aerodynamic Load (PAL) Ramp that was originally intended to protect various protuberances outside of the Space Shuttle External Tank from high buffet load induced by cross-flows at transonic speed. In order to establish the buffet load without the PAL ramp, a wind tunnel test was conducted where segments of the protuberances were instrumented with dynamic pressure transducers; and power-spectra of sectional lift and drag forces at various span-wise locations between two adjacent support brackets were measured under different cross flow angles, Mach number and other conditions. Additionally, frequency-dependent spatial correlations between the sectional forces were also established. The sectional forces were then adjusted by the correlation length to establish span-averaged spectra of normal and lateral forces that can be suitably "added" to various other unsteady forces encountered by the protuberance. This paper describes the methodology used for calculating the correlation-adjusted power spectrum of the buffet load. A second part of the paper describes wind-tunnel results on the difference in the buffet load on the protuberances with and without the PAL ramp. In general when the ramp height is the same as that of the protuberance height, such as that found on the liquid Oxygen part of the tank, the ramp is found to cause significant reduction of the unsteady aerodynamic load. However, on the liquid Hydrogen part of the tank, where the Oxygen feed-line is far larger in diameter than the height of the PAL ramp, little protection is found to be available to all but the Cable Tray.

  14. Surface modifications of W divertor components for EAST during exposure to high heat loads with He

    Energy Technology Data Exchange (ETDEWEB)

    Li, C., E-mail: lichun10@mails.tsinghua.edu.cn [Laboratory of Advanced Materials, School of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Greuner, H. [Max Planck Institute for Plasma Physics, Boltzmannstr. 2, 85748 Garching (Germany); Yuan, Y. [School of Physics and Nuclear Energy Engineering, Beihang University, Beijing 100191 (China); Zhao, S.X.; Luo, G.N. [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, Anhui 230031 (China); Böswirth, B. [Max Planck Institute for Plasma Physics, Boltzmannstr. 2, 85748 Garching (Germany); Fu, B.Q.; Jia, Y.Z. [Laboratory of Advanced Materials, School of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Liu, X. [Southwestern Institute of Physics, Chengdu, Sichuan 610041 (China); Liu, W., E-mail: liuw@mail.tsinghua.edu.cn [Laboratory of Advanced Materials, School of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China)

    2015-08-15

    Flat-type W/Cu plasma-facing components have been developed for the new generation divertor of the Chinese Experimental Advanced Superconducting Tokamak. Surface modifications of such actively water-cooled W components following short and long pulse high heat loading coupled with He particle loads with fluence of 3 × 10{sup 22} m{sup −2} have been investigated. An adiabatically loaded W block was investigated as a comparison and exposed to short pulse loads. Blistering was observed on all sample surfaces, but was less pronounced on the components than on the W block, due to the significant lower surface temperature caused by active cooling. For components, longer pulse loads gave rise to a rougher surface. Furthermore, most blisters on components are found to be less than 1 μm in diameter, with just a very few blisters larger than 1 μm, observed only in some near 〈1 1 1〉 grains.

  15. Beam heat load due to geometrical and resistive wall impedance in COLDDIAG

    Science.gov (United States)

    Casalbuoni, S.; Migliorati, M.; Mostacci, A.; Palumbo, L.; Spataro, B.

    2012-11-01

    One of the still open issues for the development of superconductive insertion devices is the understanding of the heat intake from the electron beam. With the aim of measuring the beam heat load to a cold bore and the hope to gain a deeper understanding in the underlying mechanisms, a cold vacuum chamber for diagnostics (COLDDIAG) was built. It is equipped with the following instrumentation: retarding field analyzers to measure the electron flux, temperature sensors to measure the beam heat load, pressure gauges, and mass spectrometers to measure the gas content. Possible beam heat load sources are: synchrotron radiation, wakefield effects due to geometrical and resistive wall impedance and electron/ion bombardment. The flexibility of the engineering design will allow the installation of the cryostat in different synchrotron light sources. COLDDIAG was first installed in the Diamond Light Source (DLS) in 2011. Due to a mechanical failure of the thermal transition of the cold liner, the cryostat had to be removed after one week of operation. After having implemented design changes in the thermal liner transition, COLDDIAG has been reinstalled in the DLS at the end of August 2012. In order to understand the beam heat load mechanism it is important to compare the measured COLDDIAG parameters with theoretical expectations. In this paper we report on the analytical and numerical computation of the COLDDIAG beam heat load due to coupling impedances deriving from unavoidable step transitions, ports used for pumping and diagnostics, surface roughness, and resistive wall. The results might have an important impact on future technological solutions to be applied to cold bore devices.

  16. Simulation of Be armour cracking under ITER-like transient heat loads

    Directory of Open Access Journals (Sweden)

    S. Pestchanyi

    2016-12-01

    Full Text Available Simulation of beryllium cracking under action of multiple severe surface heatings has been performed using the PEGASUS-3D code and verified by experiments in the JUDITH 1 facility. Analysis of the results has revealed beryllium thermo conductivity degradation under action of repetitive pulsed heat load due to accumulation of the cracks in the surface layer. Thermo conductivity degradation is found to be at least 4 times after 100 pulses in JUDITH 1 facility. An analytical model for the Be cracking threshold under action of arbitrary heat pulses has been developed.

  17. A simple external resistance heating diamond anvil cell and its application for synchrotron radiation x-ray diffraction.

    Science.gov (United States)

    Fan, Dawei; Zhou, Wenge; Wei, Shuyi; Liu, Yonggang; Ma, Maining; Xie, Hongsen

    2010-05-01

    A simple external heating assemblage allowing diamond anvil cell experiments at pressures up to 34 GPa and temperatures up to 653 K was constructed. This cell can be connected to the synchrotron radiation conveniently. The design and construction of this cell are fully described, as well as its applications for x-ray diffraction. Heating is carried out by using an external-heating system, which is made of NiCr resistance wire, and the temperature was measured by a NiCr-NiSi or PtRh-Pt thermocouple. We showed the performance of the new system by introducing the phase transition study of cinnabar (alpha-HgS) and thermal equation of state study of almandine at high pressure and temperature with this cell.

  18. Experimental study of an externally finned tube with internal heat transfer enhancement for phase change thermal energy storage

    Science.gov (United States)

    Martinelli, M.; Bentivoglio, F.; Couturier, R.; Fourmigué, J.-F.; Marty, P.

    2016-09-01

    After having presented the design of a latent heat thermal energy storage system (LHTESS) for district heating, experimental results of a vertical tube-in-shell LHTESS are discussed. The tube is radially finned on its external wall to enhance the heat transfer in the phase change material. The test rig is operated with flow conditions corresponding to the proposed design. As the internal flow of heat transfer fluid (HTF) appears to be laminar and is highly influenced by buoyancy forces, which results in mixed convection regime, cross-sectional area reducers are installed inside the HTF tube in order to reduce the Rayleigh number and thus natural convection. Experimental results are presented for two finned tubes, with and without internal heat transfer enhancement respectively.

  19. Natural convection and radiation heat transfer of an externally-finned tube vertically placed in a chamber

    Science.gov (United States)

    Qiu, Yan; Tian, Maocheng; Guo, Zhixiong

    2013-03-01

    A three-dimensional numerical study was made to investigate effects of fin angle, fin surface emissivity, and tube wall temperature on heat transfer enhancement for a longitudinal externally-finned tube placed vertically in a small chamber. The numerical model was first validated through comparison with experimental measurements and the appropriateness of general boundary conditions was examined. The numerical results show that the mean Nusselt number increases with Rayleigh number for all the fin angles investigated. The maximum heat transfer rate per mass occurs when the fin angle is about 60° for fin surface emissivity between 0.7 and 0.8 and 55° when the surface emissivity increases to 0.9. With increasing tube wall temperature, both the natural convection and radiation heat transfer are enhanced, but the fraction of radiation heat transfer decreases in the temperature range studied. Radiation fraction increases with increasing fin surface emissivity. Both convection and radiation heat transfer modes are important.

  20. Influence of resonant magnetic perturbations on transient heat load deposition and fast ion losses

    Energy Technology Data Exchange (ETDEWEB)

    Rack, Michael Thomas

    2014-07-11

    Thermonuclear fusion is the energy conversion process which keeps the sun shining. For the last six decades, researchers have been investigating the physics involved in order to enable the usage of this energy supply on Earth. The most promising candidates for fusion power plants are based on magnetic confinement of plasma to provide the ideal conditions for efficient thermonuclear fusion in well controlled surroundings. One important aspect is the control of instabilities that occur in the edge region of the plasma and lead to an ejection of huge amounts of energy. Magnetic perturbation fields which are resonant in the plasma edge are found to modify the plasma favourably and reduce the impact of these instabilities. This dissertation focuses on the effects of resonant magnetic perturbation fields on the ejected energy as well as on the drawbacks of these perturbation fields. The transient energy ejection which is triggered by the instabilities causes extreme heat loads on the wall components in fusion devices. Therefore, it is crucial to understand how resonant magnetic perturbation fields affect the heat load deposition. Furthermore, the impact of resonant magnetic perturbation fields on the confinement of fast ions is an important aspect as fast ions are still required to be well confined in order to avoid additional wall loads and increase the fusion efficiency. Recent upgrades on the Joint European Torus allow for a detailed study of the heat load deposition profiles caused by transient events. Throughout this work, the new features are used for the study of the modifications of the transient heat load depositions that occur if resonant magnetic perturbation fields are applied. This leads to a further understanding of the processes involved during the plasma edge instabilities. Additionally, an alternative method using lower hybrid waves for applying resonant magnetic perturbations is investigated. Furthermore, a new diagnostic, capable of detecting fast ion

  1. Effect of particle loading on heat transfer enhancement in a gas-solid suspension cross flow

    Institute of Scientific and Technical Information of China (English)

    周劲松; 骆仲泱; 高翔; 倪明江; 岑可法

    2002-01-01

    Heat transfer between gas-solid multiphase flow and tubes occurs in many industry processes, such as circulating fluidized bed process, pneumatic conveying process, chemical process, drying process, etc. (This paper focuses on the influence of the presence of particles on the heat transfer between a tube and gas-solid sus-pension. The presence of particles causes positive enhancement of heat transfer in the case of high solid loading ratio, but heat transfer reduction has been found for in the case of very low soliding ratio (Ms of less than 0.05 kg/kg). A usefial correlation ineorpomting solid lolling ratio, particle size and flow Reytmlds number was derived from experimental data. In addition, the κ-ε two-equation model and the Fluctuation-Spectrum-Random-Trajectory Model (FSRT Model) are used to simulate the flow field and heat transit of the gas-phase and the solid-phase, respectively. Through coupling of the two phases the model can predict the local and total heat transfer characteristics of tube in gas-solid cross flow. For the total heat transfer enhancement due to particles loading the model predictions agreed well wih experimental data.

  2. Fast heating and cooling in nanoimprint using a spring-loaded adapter in a preheated press

    DEFF Research Database (Denmark)

    Schift, Helmut; Bellini, Sandro; Gobrecht, Jens

    2007-01-01

    By using a spring-loaded adapter, instant heating and cooling of wafer-type substrates was implemented in standard hot embossing equipment. This was possible by using the well-known concept of a clamped stack of stamp and substrate, pre-assembled in an alignment fixture. A number of thermoplastic...

  3. Cluster analysis of residential heat load profiles and the role of technical and household characteristics

    DEFF Research Database (Denmark)

    Carmo, Carolina; Christensen, Toke Haunstrup

    2016-01-01

    segments; a main cluster with a relatively constant load profile and a minor cluster with a more distinct variation during the day. The difference between the clusters is primarily correlated with building characteristics like floor area, building year and type of space heating distribution system, while...

  4. Technology Solutions Case Study: Calculating Design Heating Loads for Superinsulated Buildings

    Energy Technology Data Exchange (ETDEWEB)

    None

    2015-08-01

    Designing a superinsulated home has many benefits including improved comfort, reduced exterior noise penetration, lower energy bills, and the ability to withstand power and fuel outages under much more comfortable conditions than a typical home. Extremely low heating and cooling loads equate to much smaller HVAC equipment than conventionally required. Sizing the mechanical system to these much lower loads reduces first costs and the size of the distribution system needed. While these homes aren't necessarily constructed with excessive mass in the form of concrete floors and walls, the amount of insulation and the increase in the thickness of the building envelope can lead to a mass effect, resulting in the structures ability to store much more heat than a code built home. This results in a very low thermal inertia making the building much less sensitive to drastic temperature swings thereby decreasing the peak heating load demand. Alternative methods that take this inertia into account along with solar and internal gains result in smaller more appropriate design loads than those calculated using Manual J version 8. During the winter of 2013/2014, the Consortium for Advanced Residential Buildings team monitored the energy use of three homes in climate zone 6 in an attempt to evaluate the accuracy of two different mechanical system sizing methods for low load homes. Based on the results, it is recommended that internal and solar gains be included and some credit for thermal inertia be used in sizing calculations for superinsulated homes.

  5. Effects of external phase on D-cycloserine loaded W/O nanocapsules prepared by the interfacial polymerization method.

    Science.gov (United States)

    Musumeci, Teresa; Ventura, Cinzia A; Carbone, Claudia; Pignatello, Rosario; Puglisi, Giovanni

    2011-07-01

    Water in oil (W/O) polybutylcyanoacrylate nanocapsules containing D-cycloserine (D-CS) for intranasal delivery were prepared by the interfacial polymerization method. Different oils, as external phase, for the preparation of the initial W/O miniemulsions were used and their effect on mean size and other physico-chemical properties were evaluated by photon correlation spectroscopy (PCS) and scanning electron microscopy (SEM) analysis. Two probes at different hydrophilicity were used to verify the internal aqueous nature of the core. Both miniemulsions and nanocapsules mean size and polydispersity index were influenced by the used external phase. Different entrapment efficiency were obtained for D-cycloserine-loaded nanocapsules correlated to the used oil [ranging from 39 to 51% encapsulation efficiency (E.E.)]. In vitro drug release showed an initial burst effect (ranging from 20 to 40%) followed by a slow release of D-CS for all preparations. This study demonstrated that many relevant physico-chemical and technological properties of polybutylcyanoacrylate nanocapsules prepared by interfacial polymerization of miniemulsions are significantly influenced by the external oil phase used.

  6. Study on mitigation of pulsed heat load for ITER cryogenic system

    Science.gov (United States)

    Peng, N.; Xiong, L. Y.; Jiang, Y. C.; Tang, J. C.; Liu, L. Q.

    2015-03-01

    One of the key requirements for ITER cryogenic system is the mitigation of the pulsed heat load deposited in the magnet system due to magnetic field variation and pulsed DT neutron production. As one of the control strategies, bypass valves of Toroidal Field (TF) case helium loop would be adjusted to mitigate the pulsed heat load to the LHe plant. A quasi-3D time-dependent thermal-hydraulic analysis of the TF winding packs and TF case has been performed to study the behaviors of TF magnets during the reference plasma scenario with the pulses of 400 s burn and repetition time of 1800 s. The model is based on a 1D helium flow and quasi-3D solid heat conduction model. The whole TF magnet is simulated taking into account thermal conduction between winding pack and case which are cooled separately. The heat loads are given as input information, which include AC losses in the conductor, eddy current losses in the structure, thermal radiation, thermal conduction and nuclear heating. The simulation results indicate that the temperature variation of TF magnet stays within the allowable range when the smooth control strategy is active.

  7. Effects of Small-Sided Soccer Games on Internal and External Load and Lower Limb Power: A Pilot Study in Collegiate Players

    Directory of Open Access Journals (Sweden)

    Clemente Filipe Manuel

    2017-03-01

    Full Text Available Purpose. The aim of the study was to examine the influence of small-sided and conditioned games (SSG on the internal load (heart rate [HR] and perceived exertion, external load (Global Positioning System variables, and lower limb power (squat jump [SJ] and countermovement jump [CMJ].

  8. Physiological responses to incremental exercise in the heat following internal and external precooling.

    Science.gov (United States)

    James, C A; Richardson, A J; Watt, P W; Gibson, O R; Maxwell, N S

    2015-06-01

    Twelve males completed three incremental, discontinuous treadmill tests in the heat [31.9(1.0) °C, 61.9(8.9)%] to determine speed at two fixed blood lactate concentrations (2 and 3.5 mmol/L), running economy (RE), and maximum oxygen uptake ( V ˙ O 2 m a x ). Trials involved 20 min of either internal cooling (ICE, 7.5 g/kg ice slurry ingestion) or mixed-methods external cooling (EXT, cold towels, forearm immersion, ice vest, and cooling shorts), alongside no intervention (CON). Following precooling, participants ran 0.3 km/h faster at 2 mmol/L and 0.2 km/h faster at 3.5 mmol/L (P = 0.04, partial η(2)  = 0.27). Statistical differences were observed vs CON for ICE (P = 0.03, d = 0.15), but not EXT (P = 0.12, d = 0.15). There was no effect of cooling on RE (P = 0.81, partial η(2)  = 0.02), nor on V ˙ O 2 m a x (P = 0.69, partial η(2)  = 0.04). An effect for cooling on physiological strain index was observed (P < 0.01, partial η(2)  = 0.41), with differences vs CON for EXT (P = 0.02, d = 0.36), but not ICE (P = 0.06, d = 0.36). Precooling reduced thermal sensation (P < 0.01, partial η(2)  = 0.66) in both cooling groups (P < 0.01). Results indicate ICE and EXT provide similar physiological responses for exercise up to 30 min duration in the heat. Differing thermoregulatory responses are suggestive of specific event characteristics determining the choice of cooling. Precooling appears to reduce blood lactate accumulation and reduce thermoregulatory and perceptual strain during incremental exercise.

  9. Direct Time Domain Numerical Analysis of Transient Behavior of a VLFS during Unsteady External Loads in Wave Condition

    Directory of Open Access Journals (Sweden)

    Yong Cheng

    2014-01-01

    Full Text Available The transient response of the VLFS subjected to arbitrary external load is systematically investigated by a direct time domain modal expansion method, in which the BEM solutions based on time domain Kelvin sources are used for hydrodynamic forces. In the analysis, the time domain free-surface Green functions with sufficient accuracy are rapidly evaluated in finite water depth by the interpolation-tabulation method, and the boundary integral equation with a quarter VLFS model is established taking advantage of symmetry of flow field and structure. The validity of the present method is verified by comparing with the time histories of vertical displacements of the VLFS during a mass drop and airplane landing and takeoff in still water conditions, respectively. Then the developed numerical scheme is used in wave conditions to study the combined action taking into account the mass drop/airplane landing/takeoff loads as well as incident wave action. It is found that the elevation of structural waves due to mass drop load can be significantly changed near the impact region, while the vertical motion of runway in wave conditions is dominant as compared with that only generated by airplane.

  10. Heat pump without particle transport or external work on the medium achieved by differential thermostatting of the phase space.

    Science.gov (United States)

    Patra, Puneet Kumar; Bhattacharya, Baidurya

    2016-03-01

    We propose a mechanism that enables heat flow from a colder region to a hotter region without necessitating either particle transport or external work on the conductor, thereby bypassing the compressor part of a classical heat pump cycle. Our mechanism relies on thermostatting the kinetic and configurational temperatures of the same particle differently. We keep the two ends of a conductor, which in the present study is a single dimensional ϕ(4) chain, at the same kinetic temperature T(0), but at different configurational temperatures--one end hotter and the other end colder than T(0). While external energy is needed within the thermostatted regions to achieve this differential thermostatting, no external work is performed on the system itself. We show that the mechanism satisfies the statistical form of the second law of thermodynamics (the fluctuation theorem). The proposed mechanism reveals two interesting findings: (i) contrary to traditional thermodynamics where only the kinetic temperature is thought to govern heat conduction, configurational temperature can also play an important role, and (ii) the relative temperature difference between the kinetic and configurational variables governs the direction of heat flow. The challenge, however, is in developing experimental techniques to thermostat the kinetic and configurational variables of the same particle at different values.

  11. Heat pump without particle transport or external work on the medium achieved by differential thermostatting of the phase space

    Science.gov (United States)

    Patra, Puneet Kumar; Bhattacharya, Baidurya

    2016-03-01

    We propose a mechanism that enables heat flow from a colder region to a hotter region without necessitating either particle transport or external work on the conductor, thereby bypassing the compressor part of a classical heat pump cycle. Our mechanism relies on thermostatting the kinetic and configurational temperatures of the same particle differently. We keep the two ends of a conductor, which in the present study is a single dimensional ϕ4 chain, at the same kinetic temperature T0, but at different configurational temperatures—one end hotter and the other end colder than T0. While external energy is needed within the thermostatted regions to achieve this differential thermostatting, no external work is performed on the system itself. We show that the mechanism satisfies the statistical form of the second law of thermodynamics (the fluctuation theorem). The proposed mechanism reveals two interesting findings: (i) contrary to traditional thermodynamics where only the kinetic temperature is thought to govern heat conduction, configurational temperature can also play an important role, and (ii) the relative temperature difference between the kinetic and configurational variables governs the direction of heat flow. The challenge, however, is in developing experimental techniques to thermostat the kinetic and configurational variables of the same particle at different values.

  12. Experimental temperature distribution and heat load characteristics of rotating heat pipes

    Science.gov (United States)

    Daniels, T. C.; Williams, R. J.

    1978-01-01

    Experimental results show conclusively that the presence of a small quantity of a noncondensable gas (NCG) mixed with the working fluid has a considerable effect on the condensation process in a rotating heat pipe. The temperature distribution in the condenser shows the blanketing effect of the NCG and the ratio of the molecular weight of the working fluid to that of the NCG has a very definite effect on the shape of this distribution. Some of the effects are quite similar to the well-established data on stationary heat pipes.

  13. Colloid volume loading does not mitigate decreases in central blood volume during simulated hemorrhage while heat stressed

    DEFF Research Database (Denmark)

    Crandall, Craig G; Wilson, Thad E; Marving, Jens

    2012-01-01

    Heat stress results in profound reductions in the capacity to withstand a simulated hemorrhagic challenge; however, this capacity is normalized if the individual is volume loaded prior to the challenge. The present study tested the hypothesis that volume loading during passive heat stress attenua...

  14. Erosion simulation of first wall beryllium armour under ITER transient heat loads

    Science.gov (United States)

    Bazylev, B.; Janeschitz, G.; Landman, I.; Pestchanyi, S.; Loarte, A.

    2009-04-01

    The beryllium is foreseen as plasma facing armour for the first wall in the ITER in form of Be-clad blanket modules in macrobrush design with brush size about 8-10 cm. In ITER significant heat loads during transient events (TE) are expected at the main chamber wall that may leads to the essential damage of the Be armour. The main mechanisms of metallic target damage remain surface melting and melt motion erosion, which determines the lifetime of the plasma facing components. Melting thresholds and melt layer depth of the Be armour under transient loads are estimated for different temperatures of the bulk Be and different shapes of transient loads. The melt motion damages of Be macrobrush armour caused by the tangential friction force and the Lorentz force are analyzed for bulk Be and different sizes of Be-brushes. The damage of FW under radiative loads arising during mitigated disruptions is numerically simulated.

  15. Phase change based cooling for high burst mode heat loads with temperature regulation above the phase change temperature

    Science.gov (United States)

    The United States of America as represented by the United States Department of Energy

    2009-12-15

    An apparatus and method for transferring thermal energy from a heat load is disclosed. In particular, use of a phase change material and specific flow designs enables cooling with temperature regulation well above the fusion temperature of the phase change material for medium and high heat loads from devices operated intermittently (in burst mode). Exemplary heat loads include burst mode lasers and laser diodes, flight avionics, and high power space instruments. Thermal energy is transferred from the heat load to liquid phase change material from a phase change material reservoir. The liquid phase change material is split into two flows. Thermal energy is transferred from the first flow via a phase change material heat sink. The second flow bypasses the phase change material heat sink and joins with liquid phase change material exiting from the phase change material heat sink. The combined liquid phase change material is returned to the liquid phase change material reservoir. The ratio of bypass flow to flow into the phase change material heat sink can be varied to adjust the temperature of the liquid phase change material returned to the liquid phase change material reservoir. Varying the flowrate and temperature of the liquid phase change material presented to the heat load determines the magnitude of thermal energy transferred from the heat load.

  16. Modelling the Slab Failure of an Open Structure Acted by External Blast Loads

    Directory of Open Access Journals (Sweden)

    Nica George Bogdan

    2016-09-01

    Full Text Available The explosion of bombs near buildings generally yields severe damages to the structures. Explosion resistant standards and requirements are constantly being developed and upgraded. This paper focuses on the damages which occur toa RC slab due to blast action. The numerical model replicates a ¼ scale experiment. The analysis is conducted using a software based on the recently developed Applied Element Method. This numerical method is able to model accurately all the structural behavior stages up to failure. The results are compared to experimental data available in the literature. The analysis reveals that the slab failure due to uplift pressures may be avoided by some simple reinforcing details, as they are listed in the Romanian National Annex – accidental loads of the Eurocode EN 1991-1-7.

  17. More power and less loads in wind farms. 'Heat and flux'

    Energy Technology Data Exchange (ETDEWEB)

    Corten, G.P.; Schaak, P. [ECN Wind Energy, Petten (Netherlands)

    2004-11-01

    We consider a farm as a single energy extracting body instead of a superposition of individual energy extractors, i.e. wind turbines. As a result we found two new hypotheses called Heat and Flux. Both hypotheses reveal that the classical operation of turbines in a wind farm at the Lanchester-Betz optimum does not lead to maximum farm output. However, when the turbines at the windward side of the farm are operated below their optimum, then the power of the turbines under the lee increases in such a way that the net farm production increases slightly. Next to this production advantage of Heat and Flux operation there is also a loading advantage. The average axial loading of the upwind turbines of a farm is reduced in a 'Heat and Flux'-farm. As a result those turbines generate less turbines so that the fatigue loads of the downwind turbines reduce too. The results were confirmed by in a boundary layer tunnel by means of differential measurements between a 'Heat and Flux'-farm and a classical farm.

  18. Kinetic modeling of divertor heat load fluxes in the Alcator C-Mod and DIII-D tokamaks

    Energy Technology Data Exchange (ETDEWEB)

    Pankin, A. Y. [Tech-X Corporation, Boulder, Colorado 80303 (United States); Rafiq, T.; Kritz, A. H. [Department of Physics, Lehigh University, Bethlehem, Pennsylvania 18015 (United States); Park, G. Y. [National Fusion Research Institute, Daejeon, 305-333 (Korea, Republic of); Chang, C. S.; Ku, S. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08540 (United States); Brunner, D.; Hughes, J. W.; LaBombard, B.; Terry, J. L. [MIT Plasma Science and Fusion Center, Cambridge, Massachusetts 02139 (United States); Groebner, R. J. [General Atomics, San Diego, California 92121 (United States)

    2015-09-15

    The guiding-center kinetic neoclassical transport code, XGC0 [Chang et al., Phys. Plasmas 11, 2649 (2004)], is used to compute the heat fluxes and the heat-load width in the outer divertor plates of Alcator C-Mod and DIII-D tokamaks. The dependence of the width of heat-load fluxes on neoclassical effects, neutral collisions, and anomalous transport is investigated using the XGC0 code. The XGC0 code includes realistic X-point geometry, a neutral source model, the effects of collisions, and a diffusion model for anomalous transport. It is observed that the width of the XGC0 neoclassical heat-load is approximately inversely proportional to the total plasma current I{sub p.} The scaling of the width of the divertor heat-load with plasma current is examined for an Alcator C-Mod discharge and four DIII-D discharges. The scaling of the divertor heat-load width with plasma current is found to be weaker in the Alcator C-Mod discharge compared to scaling found in the DIII-D discharges. The effect of neutral collisions on the 1/I{sub p} scaling of heat-load width is shown not to be significant. Although inclusion of poloidally uniform anomalous transport results in a deviation from the 1/I{sub p} scaling, the inclusion of the anomalous transport that is driven by ballooning-type instabilities results in recovering the neoclassical 1/I{sub p} scaling. The Bohm or gyro-Bohm scalings of anomalous transport do not strongly affect the dependence of the heat-load width on plasma current. The inclusion of anomalous transport, in general, results in widening the width of neoclassical divertor heat-load and enhances the neoclassical heat-load fluxes on the divertor plates. Understanding heat transport in the tokamak scrape-off layer plasmas is important for strengthening the basis for predicting divertor conditions in ITER.

  19. Dental implants with internal versus external connections: 1-year post-loading results from a pragmatic multicenter randomised controlled trial.

    Science.gov (United States)

    Esposito, Marco; Maghaireh, Hassan; Pistilli, Roberto; Grusovin, Maria Gabriella; Lee, Sang Taek; Gualini, Federico; Yoo, Jungtaek; Buti, Jacopo

    2015-01-01

    To evaluate advantages and disadvantages of identical implants with internal or external connections. Two hundred patients with any type of edentulism (single tooth, partial and total edentulism) requiring one implant-supported prosthesis were randomly allocated in two equal groups to receive either implants with an external connection (EC) or implants of the same type but with an internal connection (IC) (EZ Plus, MegaGen Implant, Gyeongbuk, South Korea) at seven centres. Due to slight differences in implant design/components, IC implants were platform switched while EC were not. Patients were followed for 1 year after initial loading. Outcome measures were prosthesis/implant failures, any complication, marginal bone level changes and clinician preference assessed by blinded outcome assessors. One hundred and two patients received 173 EC implants and 98 patients received 154 IC implants. Six patients dropped out with 11 EC implants and 3 patients with four IC implants, but all remaining patients were followed up to 1-year post-loading. Two centres did not provide any periapical radiographs. Two prostheses supported by EC implants and one supported by IC implants failed (P = 1.000, difference = -0.01, 95% CI: -0.05 to 0.04). Three EC implants failed in 3 patients versus two IC implants in 1 patient (P = 0.6227, difference = -0.02, 95% CI: -0.07 to 0.03). EC implants were affected by nine complications in 9 patients versus six complications of IC implants in 6 patients (P = 0.5988, difference = -0.02, 95% CI: -0.10 to 0.06). There were no statistically significant differences for prosthesis/implant failures and complications between the implant systems. One year after loading, there were no statistically significant differences in marginal bone level changes between the two groups (difference = 0.24, 95% CI: -0.01 to 0.50, P = 0.0629) and both groups lost bone from implant placement in a statistically significant manner: 0.98 mm for the EC implants and 0.85 mm for

  20. Total heat loss coefficient of flat roof constructions with external insulation in tapered layers including the effects of thermal bridges

    DEFF Research Database (Denmark)

    Rose, Jørgen; Svendsen, Svend

    2005-01-01

    and insulation has to be fulfilled. Based on a given design of the tapered insulation the total heat loss coefficient of the roof can be calculated using formulae in EN ISO 6946 for typical segments of the tapered insulation. Performing design and calculations for large roofs with numerous different segments can...... for design of flat roofs and a pc-program that can be used for calculating the total heat loss coefficient of externally insulated roofs with insulation in tapered layers, taking into account thermal bridges in the roof construction.......In order to achieve durability of flat roofs with external insulation, it is necessary to secure proper drainage of the roof, i.e. to avoid water leaking into the insulation. The design of the tapered insulation of the roof is quite difficult as requirements with respect to both drainage...

  1. Online short-term heat load forecasting for single family houses

    DEFF Research Database (Denmark)

    Bacher, Peder; Madsen, Henrik; Nielsen, Henrik Aalborg

    2013-01-01

    This paper presents a method for forecasting the load for heating in a single-family house. Both space and hot tap water heating are forecasted. The forecasting model is built using data from sixteen houses in Sønderborg, Denmark, combined with local climate measurements and weather forecasts....... The models are optimized to fit the level of optimal adaptivity and the thermal dynamical response of the building. Identification of a model, which is suitable for application to all the houses, is carried out. The results show that the forecasting errors mainly are related to: unpredictable high frequency...

  2. New heating load calculation in practice; Neue Heizlastberechnung in der Praxis

    Energy Technology Data Exchange (ETDEWEB)

    Kroeber, C. [REHAU AG und Co., REHAU-Akademie, Erlangen (Germany)

    2004-07-01

    First the heating demand/standard heat load of the building is calculated related to DIN 4701 and than by DIN EN 12831. The topic is to considerate not new formulas and calculation steps but looking on the results of the calculation and discussing it. (GL) [German] Am Beispiel eines Mehrfamilienhauses soll dieser Frage auf den Grund gegangen werden. Dazu wird der Norm-Waermebedarf/die Norm-Heizlast des Gebaeudes zuerst nach DIN 4701 und dann nach DIN EN 12831 berechnet. Dabei liegt der Schwerpunkt der Betrachtung nicht auf den neuen Berechnungsansaetzen und Formeln, sondern vielmehr auf der Betrachtung der Berechnungsergebnisse. (orig.)

  3. Measuring the Heat Load on the Flight ASTRO-H Soft Xray Spectrometer Dewar

    Science.gov (United States)

    DiPirro, M.; Shirron, P.; Yoshida, S.; Kanao, K.; Tsunematsu, S.; Fujimoto, R.; Sneiderman, G.; Kimball, M.; Ezoe, Y.; Ishikawa, K.; Takei, Y.; Mitsuda, K.; Kelley, R.

    2015-01-01

    The Soft Xray Spectrometer (SXS) instrument on-board the ASTRO-H X-ray mission is based on microcalorimeters operating at 50 mK. Low temperature is achieved by use of an adiabatic demagnetization refrigerator (ADR) cyclically operating up to a heat sink at either 1.2 K or 4.5 K. The 1.2 K heat sink is provided by a 40 liter superfluid helium dewar. The parasitic heat to the helium from supports, plumbing, wires, and radiation, and the cyclic heat dumped by the ADR operation determine the liquid helium lifetime. To measure this lifetime we have used various techniques to rapidly achieve thermal equilibrium and then measure the boil-off rate of the helium. We have measured a parasitic heat of 650 microwatts and a cyclic heat of 100 microwatts for a total of 750 microwatts. This closely matches the predicted heat load. Starting with a fill level at launch of more than 33 liters results in a lifetime of greater than 4 years for the liquid helium. The techniques and accuracy for this measurement will be explained in this paper.

  4. Calibration of a silver thin film gauge for short duration convective step heat load

    Indian Academy of Sciences (India)

    SHRUTIDHARA SARMA; NIRANJAN SAHOO; AYNUR UNAL

    2016-07-01

    Thin film gauges (TFGs) are a promising candidate for measuring transient heat fluxes in the applications involving very short duration of heating environment. They are basically resistance temperature detectors (RTDs) having the capability of responding in the range of few microseconds. In the present study, asilver thin film gauge (STFG) is fabricated and calibrated in-house with a view to assess the performance of STFGs in dynamic environment. Convective heat load is supplied by a hot-air gun where the heated air jet strikes the gauge and its response is obtained through voltage signal. Subsequently, the surface heat fluxes are estimated by using one dimensional heat conduction modeling. The similar experimental environment is studied to obtain the flow behavior of hot-air jet emanating into atmosphere by using numerical simulations. The selfsimilar velocities are plotted as well as the interference of outer domain into the experiment parameters has been studied. Ultimately, the surface heat fluxes obtained from various methods are compared to analyse the performance of this hand-made STFG. This study reveals the ability of STFGs to be used in practical short duration transient situations.

  5. An Optimal Control Approach for an Overall Cryogenic Plant Under Pulsed Heat Loads

    CERN Document Server

    Gómez Palacin, Luis; Blanco Viñuela, Enrique; Maekawa, Ryuji; Chalifour, Michel

    2015-01-01

    This work deals with the optimal management of a cryogenic plant composed by parallel refrigeration plants, which provide supercritical helium to pulsed heat loads. First, a data reconciliation approach is proposed to estimate precisely the refrigerator variables necessary to deduce the efficiency of each refrigerator. Second, taking into account these efficiencies, an optimal operation of the system is proposed and studied. Finally, while minimizing the power consumption of the refrigerators, the control system maintains stable operation of the cryoplant under pulsed heat loads. The management of the refrigerators is carried out by an upper control layer, which balances the relative production of cooling power in each refrigerator. In addition, this upper control layer deals with the mitigation of malfunctions and faults in the system. The proposed approach has been validated using a dynamic model of the cryoplant developed with EcosimPro software, based on first principles (mass and energy balances) and the...

  6. Effect of Shear Resistance on Flexural Debonding Load-Carrying Capacity of RC Beams Strengthened with Externally Bonded FRP Composites

    Directory of Open Access Journals (Sweden)

    Guibing Li

    2014-05-01

    Full Text Available Debonding failure is the main failure mode in flexurally strengthened reinforced concrete beams by externally bonded or near surface mounted fibre reinforced polymer (FRP composites. It is believed that FRP debonding will be initiated if the shear stress on the concrete-FRP interface reaches the tensile strength of concrete. However, it was found through experimental and analytical studies that the debonding mechanism of FRP composites has the potential of shear failure in combination with debonding failure. Moreover, the shear failure probably influences the debonding failure. Presently, there are very little experimental and analytical studies to investigate the influence of shear resistance of reinforced concrete (RC beam on FRP debonding failure. The current study investigates and analyzes the effect of shear resistance on FRP debonding failure based on test results. The analytical results show that the shear resistance of RC beam has a great effect on flexural debonding load-carrying capacity of FRP-strengthened RC beam. The influence of shear resistance on flexural debonding load-carrying capacity must be fully considered in flexural strengthening design of RC beams.

  7. Design and implementation of a multiaxial loading capability during heating on an engineering neutron diffractometer

    Energy Technology Data Exchange (ETDEWEB)

    Benafan, O., E-mail: othmane.benafan@nasa.gov [NASA Glenn Research Center, Structures and Materials Division, Cleveland, Ohio 44135 (United States); Advanced Materials Processing and Analysis Center, Materials Science and Engineering Department, University of Central Florida, Orlando, Florida 32816 (United States); Padula, S. A. [NASA Glenn Research Center, Structures and Materials Division, Cleveland, Ohio 44135 (United States); Skorpenske, H. D.; An, K. [Spallation Neutron Source, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States); Vaidyanathan, R. [Advanced Materials Processing and Analysis Center, Materials Science and Engineering Department, University of Central Florida, Orlando, Florida 32816 (United States)

    2014-10-01

    A gripping capability was designed, implemented, and tested for in situ neutron diffraction measurements during multiaxial loading and heating on the VULCAN engineering materials diffractometer at the spallation neutron source at Oak Ridge National Laboratory. The proposed capability allowed for the acquisition of neutron spectra during tension, compression, torsion, and/or complex loading paths at elevated temperatures. The design consisted of age-hardened, Inconel{sup ®} 718 grips with direct attachment to the existing MTS load frame having axial and torsional capacities of 100 kN and 400 N·m, respectively. Internal cooling passages were incorporated into the gripping system for fast cooling rates during high temperature experiments up to ~1000 K. The specimen mounting couplers combined a threaded and hexed end-connection for ease of sample installation/removal without introducing any unwanted loads. Instrumentation of this capability is documented in this work along with various performance parameters. The gripping system was utilized to investigate deformation in NiTi shape memory alloys under various loading/control modes (e.g., isothermal, isobaric, and cyclic), and preliminary results are presented. The measurements facilitated the quantification of the texture, internal strain, and phase fraction evolution in NiTi shape memory alloys under various loading/control modes.

  8. Design and implementation of a multiaxial loading capability during heating on an engineering neutron diffractometer

    Science.gov (United States)

    Benafan, O.; Padula, S. A.; Skorpenske, H. D.; An, K.; Vaidyanathan, R.

    2014-10-01

    A gripping capability was designed, implemented, and tested for in situ neutron diffraction measurements during multiaxial loading and heating on the VULCAN engineering materials diffractometer at the spallation neutron source at Oak Ridge National Laboratory. The proposed capability allowed for the acquisition of neutron spectra during tension, compression, torsion, and/or complex loading paths at elevated temperatures. The design consisted of age-hardened, Inconel® 718 grips with direct attachment to the existing MTS load frame having axial and torsional capacities of 100 kN and 400 N.m, respectively. Internal cooling passages were incorporated into the gripping system for fast cooling rates during high temperature experiments up to ˜1000 K. The specimen mounting couplers combined a threaded and hexed end-connection for ease of sample installation/removal without introducing any unwanted loads. Instrumentation of this capability is documented in this work along with various performance parameters. The gripping system was utilized to investigate deformation in NiTi shape memory alloys under various loading/control modes (e.g., isothermal, isobaric, and cyclic), and preliminary results are presented. The measurements facilitated the quantification of the texture, internal strain, and phase fraction evolution in NiTi shape memory alloys under various loading/control modes.

  9. A Large-scale Test Facility for Heat Load Measurements down to 1.9 K

    CERN Document Server

    Dufay, L; Rieubland, Jean Michel; Vandoni, Giovanna

    2002-01-01

    Laboratory-scale tests aimed at minimizing the thermal loads of the LHC magnet cryostat have gone along with the development of the various mechanical components. For final validation of the industrial design with respect to heat inleaks between large surfaces at different temperatures, a full-scale test cryostat has been constructed. The facility reproduces the same pattern of temperature levels as the LHC dipole cryostat, avoiding the heat inleaks from local components like supports and feedthroughs and carefully minimizing fringe effects due to the truncated geometry of the facility with respect to the LHC cryostats serial layout. Thermal loads to the actively cooled radiation screen, operated between 50 K and 65 K, are measured by enthalpy difference along its length. At 1.9 K, the loads are obtained from the temperature difference across a superfluid helium exchanger. On the beam screen, the electrical power needed to stabilize the temperature at 20 K yields a direct reading of the heat losses. Precise i...

  10. Titanium tritide radioisotope heat source development : palladium-coated titanium hydriding kinetics and tritium loading tests.

    Energy Technology Data Exchange (ETDEWEB)

    Van Blarigan, Peter; Shugard, Andrew D.; Walters, R. Tom (Savannah River National Labs, Aiken, SC)

    2012-01-01

    We have found that a 180 nm palladium coating enables titanium to be loaded with hydrogen isotopes without the typical 400-500 C vacuum activation step. The hydriding kinetics of Pd coated Ti can be described by the Mintz-Bloch adherent film model, where the rate of hydrogen absorption is controlled by diffusion through an adherent metal-hydride layer. Hydriding rate constants of Pd coated and vacuum activated Ti were found to be very similar. In addition, deuterium/tritium loading experiments were done on stacks of Pd coated Ti foil in a representative-size radioisotope heat source vessel. The experiments demonstrated that such a vessel could be loaded completely, at temperatures below 300 C, in less than 10 hours, using existing department-of-energy tritium handling infrastructure.

  11. Transient modelling of heat loading of phase change material for energy storage

    Directory of Open Access Journals (Sweden)

    Asyraf W.M.

    2017-01-01

    Full Text Available As the development of solar energy is getting advance from time to time, the concentration solar technology also get the similar attention from the researchers all around the globe. This technology concentrate a large amount of energy into main spot. To collect all the available energy harvest from the solar panel, a thermal energy storage is required to convert the heat energy to one of the purpose such as electrical energy. With the idea of energy storage application that can be narrow down to commercial application such as cooking stove. Using latent heat type energy storage seem to be appropriate with the usage of phase change material (PCM that can release and absorb heat energy at nearly constant temperature by changing its state. Sodium nitrate (NaNO3 and potassium nitrate (KNO3 was selected to use as PCM in this project. This paper focus on the heat loading process and the melting process of the PCM in the energy storage using a computer simulation. The model of the energy storage was created as solid three dimensional modelling using computer aided software and the geometry size of it depend on how much it can apply to boil 1 kg of water in cooking application. The materials used in the tank, heat exchanger and the heat transfer fluid are stainless steel, copper and XCELTHERM MK1, respectively. The analysis was performed using a commercial simulation software in a transient state. The simulation run on different value of velocity but kept controlled under laminar state only, then the relationship of velocity and heat distribution was studied and the melting process of the PCM also has been analyzed. On the effect of heat transfer fluid velocity, the higher the velocity resulted in higher the rate of heat transfer. The comparison between the melting percentages of the PCMs under test conditions show that NaNO3 melts quite faster than KNO3.

  12. Flight Testing and Real-Time System Identification Analysis of a UH-60A Black Hawk Helicopter with an Instrumented External Sling Load

    Science.gov (United States)

    McCoy, Allen H.

    1998-01-01

    Helicopter external air transportation plays an important role in today's world. For both military and civilian helicopters, external sling load operations offer an efficient and expedient method of handling heavy, oversized cargo. With the ability to reach areas otherwise inaccessible by ground transportation, helicopter external load operations are conducted in industries such as logging, construction, and fire fighting, as well as in support of military tactical transport missions. Historically, helicopter and load combinations have been qualified through flight testing, requiring considerable time and cost. With advancements in simulation and flight test techniques there is potential to substantially reduce costs and increase the safety of helicopter sling load certification. Validated simulation tools make possible accurate prediction of operational flight characteristics before initial flight tests. Real time analysis of test data improves the safety and efficiency of the testing programs. To advance these concepts, the U.S. Army and NASA, in cooperation with the Israeli Air Force and Technion, under a Memorandum of Agreement, seek to develop and validate a numerical model of the UH-60 with sling load and demonstrate a method of near real time flight test analysis. This thesis presents results from flight tests of a U.S. Army Black Hawk helicopter with various external loads. Tests were conducted as the U.S. first phase of this MOA task. The primary load was a container express box (CONEX) which contained a compact instrumentation package. The flights covered the airspeed range from hover to 70 knots. Primary maneuvers were pitch and roll frequency sweeps, steps, and doublets. Results of the test determined the effect of the suspended load on both the aircraft's handling qualities and its control system's stability margins. Included were calculations of the stability characteristics of the load's pendular motion. Utilizing CIFER(R) software, a method for near

  13. Analysis of classical Fourier, SPL and DPL heat transfer model in biological tissues in presence of metabolic and external heat source

    Science.gov (United States)

    Kumar, Dinesh; Singh, Surjan; Rai, K. N.

    2016-06-01

    In this paper, the temperature distribution in a finite biological tissue in presence of metabolic and external heat source when the surface subjected to different type of boundary conditions is studied. Classical Fourier, single-phase-lag (SPL) and dual-phase-lag (DPL) models were developed for bio-heat transfer in biological tissues. The analytical solution obtained for all the three models using Laplace transform technique and results are compared. The effect of the variability of different parameters such as relaxation time, metabolic heat source, spatial heat source, different type boundary conditions on temperature distribution in different type of the tissues like muscle, tumor, fat, dermis and subcutaneous based on three models are analyzed and discussed in detail. The result obtained in three models is compared with experimental observation of Stolwijk and Hardy (Pflug Arch 291:129-162, 1966). It has been observe that the DPL bio-heat transfer model provides better result in comparison of other two models. The value of metabolic and spatial heat source in boundary condition of first, second and third kind for different type of thermal therapies are evaluated.

  14. Current Status and Performance Tests of Korea Heat Load Test Facility KoHLT-EB

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sukkwon; Jin, Hyunggon; Shin, Kyuin; Choi, Boguen; Lee, Eohwak; Yoon, Jaesung; Lee, Dongwon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Kim, Duckhoi; Cho, Seungyon [National Fusion Research Institute, Daejeon (Korea, Republic of)

    2013-05-15

    A commissioning test has been scheduled to establish the installation and preliminary performance experiments of the copper hypervapotron mockups. And a qualification test will be performed to evaluate the CuCrZr duct liner in the ITER neutral beam injection facility and the ITER first wall small-scale mockups of the semi-prototype, at up to 1.5 and 5 MW/m{sup 2} high heat flux. Also, this system will be used to test other PFCs for ITER and materials for tokamak reactors. Korean high heat flux test facility(KoHLT-EB; Korea Heat Load Test facility - Electron Beam) by using an electron beam system has been constructed in KAERI to perform the qualification test for ITER blanket FW semi-prototype mockups, hypervapotron cooling devices in fusion devices, and other ITER plasma facing components. The commissioning and performance tests with the supplier of e-gun system have been performed on November 2012. The high heat flux test for hypervapotron cooling device and calorimetry were performed to measure the surface heat flux, the temperature profile and cooling performance. Korean high heat flux test facility for the plasma facing components of nuclear fusion machines will be constructed to evaluate the performance of each component. This facility for the plasma facing materials will be equipped with an electron beam system with a 60 kV acceleration gun.

  15. Oligonol Supplementation Affects Leukocyte and Immune Cell Counts after Heat Loading in Humans

    Directory of Open Access Journals (Sweden)

    Jeong Beom Lee

    2014-06-01

    Full Text Available Oligonol is a low-molecular-weight form of polyphenol and has antioxidant and anti-inflammatory activity, making it a potential promoter of immunity. This study investigates the effects of oligonol supplementation on leukocyte and immune cell counts after heat loading in 19 healthy male volunteers. The participants took a daily dose of 200 mg oligonol or a placebo for 1 week. After a 2-week washout period, the subjects were switched to the other study arm. After each supplement, half-body immersion into hot water was made, and blood was collected. Then, complete and differential blood counts were performed. Flow cytometry was used to enumerate and phenotype lymphocyte subsets. Serum concentrations of interleukin (IL-1β and IL-6 in blood samples were analyzed. Lymphocyte subpopulation variables included counts of total T cells, B cells, and natural killer (NK cells. Oligonol intake attenuated elevations in IL-1β (an 11.1-fold change vs. a 13.9-fold change immediately after heating; a 12.0-fold change vs. a 12.6-fold change 1h after heating and IL-6 (an 8.6-fold change vs. a 9.9-fold change immediately after heating; a 9.1-fold change vs. a 10.5-fold change 1h after heating immediately and 1 h after heating in comparison to those in the placebo group. Oligonol supplementation led to significantly higher numbers of leukocytes (a 30.0% change vs. a 21.5% change immediately after heating; a 13.5% change vs. a 3.5% change 1h after heating and lymphocytes (a 47.3% change vs. a 39.3% change immediately after heating; a 19.08% change vs. a 2.1% change 1h after heating relative to those in the placebo group. Oligonol intake led to larger increases in T cells, B cells, and NK cells at rest (p < 0.05, p < 0.05, and p < 0.001, respectively and immediately after heating (p < 0.001 in comparison to those in the placebo group. In addition, levels of T cells (p < 0.001 and B cells (p < 0.001 were significantly higher 1 h after heating in comparison to those in

  16. The cryogenic cooling program in high-heat-load optics at the Advanced Photon Source

    Energy Technology Data Exchange (ETDEWEB)

    Rogers, C.S.

    1993-07-01

    This paper describes some of the aspects of the cryogenic optics program at the Advanced Photon Source (APS). A liquid-nitrogen-cooled, high-vacuum, double crystal monochromator is being fabricated at Argonne National Laboratory (ANL). A pumping system capable of delivering a variable flow rate of up to 10 gallons per minute of pressurized liquid nitrogen and removing 5 kilowatts of x-ray power is also being constructed. This specialized pumping system and monochromator will be used to test the viability of cryogenically cooled, high-heat-load synchrotron optics. It has been determined that heat transfer enhancement will be required for optics used with APS insertion devices. An analysis of a porous-matrix-enhanced monochromator crystal is presented. For the particular case investigated, a heat transfer enhancement factor of 5 to 6 was calculated.

  17. Initiation of Heated PBX-9501 Explosive When Exposed to Dynamic Loading

    Energy Technology Data Exchange (ETDEWEB)

    Urtiew, P A; Vandersall, K S; Tarver, C M; Garcia, F

    2005-08-16

    Shock initiation experiments on the heated PBX9501 explosive (95% HMX, 2.5% estane, and 2.5% nitro-plasticizer by weight) were performed at temperatures 150 C and 180 C to obtain in-situ pressure gauge data. A 101 mm diameter propellant driven gas gun was utilized to initiate the PBX9501 explosive and manganin piezo-resistive pressure gauge packages were placed between sample slices to measure time resolved local pressure histories. The run-distance-to-detonation points on the Pop-plot for these experiments showed the sensitivity of the heated material to shock loading. This work shows that heated PBX-9501 is more shock sensitive than it is at ambient conditions. Proper Ignition and Growth modeling parameters were obtained to fit the experimental data. This parameter set will allow accurate code predictions to be calculated for safety scenarios involving PBX9501 explosives at temperatures close to those at which experiments were performed.

  18. Using Simulink Simulation to Evaluate Load Following Characteristics of SOFC Generator with Heat Exchanger Considering Heat Balance

    Science.gov (United States)

    Tuyen, Nguyen Duc; Fujita, Goro; Yokoyama, Ryuichi; Koyanagi, Kaoru; Funabashi, Toshihisa; Nomura, Masakatsu

    That ever increasing electricity consumption, progress in power deregulation, and rising public awareness for environment have created more interest in fuel cell distributed generation. Among different types of fuel cells, solid oxide fuel cells (SOFCs) manifest themselves as great potential applications due to many advantages such as low emission, high efficiency, and high power rating. On the other hand, SOFC systems are beneficial because they can convert fuel such as natural gas (almost CH4) which is supplied by widespread systems in many countries into electricity efficiently using internal reforming. In facts, the load demand changes flexibly and fuel cell life time decreases by rapid thermal change. Its lifetime may be extended by maintaining in appropriate temperature. Therefore, it is important to acquire the load following performance as well as control of operation temperature. This paper addresses components of the simple SOFC power unit model with heat exchanger (HX) included. Typical dynamical submodels are used to follow the variation of load demand at a local location that considers temperature characteristics using the Matlab-SIMULINK program.

  19. Influence of the heater material on the critical heat load at boiling of liquids on surfaces with different sizes

    Science.gov (United States)

    Anokhina, E. V.

    2010-05-01

    Data on critical heat loads q cr for the saturated and unsaturated pool boiling of water and ethanol under atmospheric pressure are reported. It is found experimentally that the critical heat load does not necessarily coincide with the heat load causing burnout of the heater, which should be taken into account. The absolute values of q cr for the boiling of water and ethanol on copper surfaces 65, 80, 100, 120, and 200 μm in diameter; tungsten surface 100 μm in diameter; and nichrome surface 100 μm in diameter are obtained experimentally.

  20. Heat loads of transparent construction elements and sun shading systems; Waermelasten transparenter Bauteile und Sonnenschutzsysteme

    Energy Technology Data Exchange (ETDEWEB)

    Simmler, H.; Binder, B.; Vonbank, R.

    2000-07-01

    This report for the Swiss Federal Office of Energy (SFOE) describes a test system installed at the Swiss Federal Laboratories for Materials Testing and Research (EMPA) in Duebendorf, Switzerland, for the investigation of heat gain by glazing elements often used in modern architecture and the efficiency of shading elements. The two climatically controlled test cells for the measurement of the thermal characteristics of facade elements and shading systems are described and the results of measurements made using various types of glazing and shading systems - including external and internal lamellas, blinds and extendible fabric sunshades - are presented. The results are analysed and interpreted in a comprehensive appendix.

  1. Tungsten joining with copper alloy and its high heat load performance

    Science.gov (United States)

    Liu, Xiang; Lian, Youyun; Chen, Lei; Cheng, Zengkui; Chen, Jiming; Duan, Xuru; Song, Jioupeng; Yu, Yang

    2014-12-01

    W-CuCrZr joining technology by using low activation Cu-Mn filler metal was developed at Southwestern Institute of Physics (SWIP) for the manufacturing of divertor components of fusion experiment devices. In addition, a fast W coating technology by chemical vapor deposition (CVD) was also developed and CVD-W/CuCrZr and CVD-W/C mockups with a W coating thickness of 2 mm were prepared. In order to assess their high heat flux (HHF) performances, a 60 kW Electron-beam Material testing Scenario (EMS-60) equipped with a 150 keV electron beam welding gun was constructed at SWIP. Experimental results indicated that brazed W/CuCrZr mockups can withstand 8 MW/m2 heat flux for 1000 cycles without visible damages and CVD-W/CuCrZr mockups with W-Cu gradient interface can survive 1000 cycles under 11 MW/m2 heat flux. An ultrasonic inspection method for non-destructive tests (NDT) of brazed W/CuCrZr mockups was established and 2 mm defect can be detected. Infinite element analysis and heat load tests indicated that 5 mm defect had less noticeable influence on the heat transfer.

  2. Effect of insulating layer material on RF-induced heating for external fixation system in 1.5 T MRI system.

    Science.gov (United States)

    Liu, Yan; Kainz, Wolfgang; Qian, Songsong; Wu, Wen; Chen, Ji

    2014-09-01

    The radio frequency (RF)-induced heating is a major concern when patients with medical devices are placed inside a magnetic resonance imaging (MRI) system. In this article, numerical studies are applied to investigate the potentials of using insulated materials to reduce the RF heating for external fixation devices. It is found that by changing the dielectric constant of the insulation material, the RF-induced heating at the tips of devices can be altered. This study indicates a potential technique of developing external fixation device with low MRI RF heating.

  3. Risk Assessment of Heating, Ventilating, and Air-Conditioning Strategies in Low-Load Homes

    Energy Technology Data Exchange (ETDEWEB)

    Poerschke, Andrew [IBACOS, Inc., Pittsburgh, PA (United States)

    2016-02-17

    "Modern, energy efficient homes conforming to the Zero Energy Ready Home standard face the challenge of meeting high customer expectations for comfort. Traditional heating, ventilation, and air conditioning (HVAC) sizing and control strategies may be insufficient to adequately condition each zone due to unique load patterns in each room caused by a number of factors. These factors include solar heat gains, occupant-related gains, and gains associated with appliances and electronics. Because of shrinking shell loads, these intermittent factors are having an increasingly significant impact on the thermal load in each zone. Consequently, occupant comfort can be compromised. To evaluate the impact of climate and house geometry, as well as HVAC system and control strategies on comfort conditions, IBACOS analyzed the results of 99 TRNSYS multiple-zone simulations. The results of this analysis indicate that for simple-geometry and single-story plans, a single zone and thermostat can adequately condition the entire house. Demanding house geometry and houses with multiple stories require the consideration of multiple thermostats and multiple zones.

  4. Blast load estimation using Finite Volume Method and linear heat transfer

    Directory of Open Access Journals (Sweden)

    Lidner Michał

    2016-01-01

    Full Text Available From the point of view of people and building security one of the main destroying factor is the blast load. Rational estimating of its results should be preceded with knowledge of complex wave field distribution in time and space. As a result one can estimate the blast load distribution in time. In considered conditions, the values of blast load are estimating using the empirical functions of overpressure distribution in time (Δp(t. The Δp(t functions are monotonic and are the approximation of reality. The distributions of these functions are often linearized due to simplifying of estimating the blast reaction of elements. The article presents a method of numerical analysis of the phenomenon of the air shock wave propagation. The main scope of this paper is getting the ability to make more realistic the Δp(t functions. An explicit own solution using Finite Volume Method was used. This method considers changes in energy due to heat transfer with conservation of linear heat transfer. For validation, the results of numerical analysis were compared with the literature reports. Values of impulse, pressure, and its duration were studied.

  5. Recrystallization and grain growth induced by ELMs-like transient heat loads in deformed tungsten samples.

    Science.gov (United States)

    Suslova, A; El-Atwani, O; Sagapuram, D; Harilal, S S; Hassanein, A

    2014-11-04

    Tungsten has been chosen as the main candidate for plasma facing components (PFCs) due to its superior properties under extreme operating conditions in future nuclear fusion reactors such as ITER. One of the serious issues for PFCs is the high heat load during transient events such as ELMs and disruption in the reactor. Recrystallization and grain size growth in PFC materials caused by transients are undesirable changes in the material, since the isotropic microstructure developed after recrystallization exhibits a higher ductile-to-brittle transition temperature which increases with the grain size, a lower thermal shock fatigue resistance, a lower mechanical strength, and an increased surface roughening. The current work was focused on careful determination of the threshold parameters for surface recrystallization, grain growth rate, and thermal shock fatigue resistance under ELM-like transient heat events. Transient heat loads were simulated using long pulse laser beams for two different grades of ultrafine-grained tungsten. It was observed that cold rolled tungsten demonstrated better power handling capabilities and higher thermal stress fatigue resistance compared to severely deformed tungsten. Higher recrystallization threshold, slower grain growth, and lower degree of surface roughening were observed in the cold rolled tungsten.

  6. Modelling reduction of urban heat load in Vienna by modifying surface properties of roofs

    Science.gov (United States)

    Žuvela-Aloise, Maja; Andre, Konrad; Schwaiger, Hannes; Bird, David Neil; Gallaun, Heinz

    2017-01-01

    The study examines the potential of urban roofs to reduce the urban heat island (UHI) effect by changing their reflectivity and implementing vegetation (green roofs) using the example of the City of Vienna. The urban modelling simulations are performed based on high-resolution orography and land use data, climatological observations, surface albedo values from satellite imagery and registry of the green roof potential in Vienna. The modelling results show that a moderate increase in reflectivity of roofs (up to 0.45) reduces the mean summer temperatures in the densely built-up environment by approximately 0.25 °C. Applying high reflectivity materials (roof albedo up to 0.7) leads to average cooling in densely built-up area of approximately 0.5 °C. The green roofs yield a heat load reduction in similar order of magnitude as the high reflectivity materials. However, only 45 % of roof area in Vienna is suitable for greening and the green roof potential mostly applies to industrial areas in city outskirts and is therefore not sufficient for substantial reduction of the UHI effect, particularly in the city centre which has the highest heat load. The strongest cooling effect can be achieved by combining the green roofs with high reflectivity materials. In this case, using 50 or 100 % of the green roof potential and applying high reflectivity materials on the remaining surfaces have a similar cooling effect.

  7. Behavior of Brazed W/Cu Mockup Under High Heat Flux Loads

    Science.gov (United States)

    Chen, Lei; Lian, Youyun; Liu, Xiang

    2014-03-01

    In order to transfer the heat from the armor to the coolant, tungsten has to be connected with a copper heat sink. The joint technology is the most critical issue for manufacturing plasma facing components. Consequently, the reliability of the joints should be verified by a great number of high-heat-flux (HHF) tests to simulate the real load conditions. W/Cu brazed joint technology with sliver free filler metal CuMnNi has been developed at Southwestern Institute of Physics (SWIP). Screening and thermal fatigue tests of one small-scale flat tile W/CuCrZr mockup were performed on a 60 kW electron-beam Material testing scenario (EMS-60) constructed recently at SWIP. The module successfully survived screening test with the absorbed power density (Pabs) of 2 MW/m2 to 10 MW/m2 and the following 1000 cycles at Pabs of 7.2 MW/m2 without hot spots and overheating zones during the whole test campaign. Metallurgy and SEM observations did not find any cracks at both sides and the interface, indicating a good bonding of W and CuCrZr alloy. In addition, finite element simulations by ANSYS 12.0 under experimental load conditions were performed and compared with experimental results.

  8. Numerical Modeling of Conjugate Thermogravitational Convection in a Closed System with a Radiant Energy Source in Conditions of Convective-Radiative Heat Exchange at the External Boundary

    OpenAIRE

    Nee Alexander

    2016-01-01

    Mathematical modeling of conjugate natural convection in a closed rectangular cavity with a radiant energy source in conditions of convective-radiative heat exchange at the external boundary was conducted. The radiant energy distribution was set by the Lambert’s law. Conduction and convection processes analysis showed that the air masses flow pattern is modified slightly over the time. The temperature increases in the gas cavity, despite the heat removal from the one of the external boundary....

  9. External magnetic field effect on the growth rate of a plasma-loaded free-electron laser

    Science.gov (United States)

    Esmaeildoost, N.; Jafari, S.; Abbasi, E.

    2016-06-01

    In order to extend the production of intense coherent radiation to angstrom wavelengths, a laser wave is employed as a laser wiggler which propagates through a magnetized plasma channel. The plasma-loaded laser wigglers increase the ability of laser guidance and electron bunching process compared to the counterpropagating laser wigglers in vacuum. The presence of the plasma medium can make it possible to propagate the laser wiggler and the electron beam parallel to each other so that the focusing of the pulse will be saved. In addition, employing an external guide magnetic field can confine both the ambient plasma and the transverse motions of the electron beam, therefore, improving the free-electron lasers' efficiency, properly. Electron trajectories have been obtained by solving the steady state equations of motion for a single particle and the fourth-order Runge-Kutta method has been used to simulate the electron orbits. To study the growth rate of a laser-pumped free-electron laser in the presence of a plasma medium, perturbation analysis has been performed to combine the momentum transfer, continuity, and wave equations, respectively. Numerical calculations indicate that by increasing the guide magnetic field frequency, the growth rate for group I orbits increases, while for group II and III orbits decreases.

  10. Total heat loss coefficient of flat roof constructions with external insulation in tapered layers including the effects of thermal bridges

    DEFF Research Database (Denmark)

    Rose, Jørgen; Svendsen, Svend

    2005-01-01

    be quite tedious, and therefore a method to generate and optimize solutions has been developed and implemented in a program that also takes into account the effects of different types of thermal bridges, i.e. roof windows, insulation fasteners, roof/wall joints etc. This paper describes a new method...... for design of flat roofs and a pc-program that can be used for calculating the total heat loss coefficient of externally insulated roofs with insulation in tapered layers, taking into account thermal bridges in the roof construction....

  11. Impact of Groundwater Flow and Energy Load on Multiple Borehole Heat Exchangers.

    Science.gov (United States)

    Dehkordi, S Emad; Schincariol, Robert A; Olofsson, Bo

    2015-01-01

    The effect of array configuration, that is, number, layout, and spacing, on the performance of multiple borehole heat exchangers (BHEs) is generally known under the assumption of fully conductive transport. The effect of groundwater flow on BHE performance is also well established, but most commonly for single BHEs. In multiple-BHE systems the effect of groundwater advection can be more complicated due to the induced thermal interference between the boreholes. To ascertain the influence of groundwater flow and borehole arrangement, this study investigates single- and multi-BHE systems of various configurations. Moreover, the influence of energy load balance is also examined. The results from corresponding cases with and without groundwater flow as well as balanced and unbalanced energy loads are cross-compared. The groundwater flux value, 10(-7) m/s, is chosen based on the findings of previous studies on groundwater flow interaction with BHEs and thermal response tests. It is observed that multi-BHE systems with balanced loads are less sensitive to array configuration attributes and groundwater flow, in the long-term. Conversely, multi-BHE systems with unbalanced loads are influenced by borehole array configuration as well as groundwater flow; these effects become more pronounced with time, unlike when the load is balanced. Groundwater flow has more influence on stabilizing loop temperatures, compared to array characteristics. Although borehole thermal energy storage (BTES) systems have a balanced energy load function, preliminary investigation on their efficiency shows a negative impact by groundwater which is due to their dependency on high temperature gradients between the boreholes and surroundings.

  12. Determination of Optimum Thermal Insulation Thicknesses for External Walls Considering the Heating, Cooling and Annual Energy Requirement

    Directory of Open Access Journals (Sweden)

    Ömer KAYNAKLI

    2016-06-01

    Full Text Available In this study, optimization of thermal insulation thickness applied to the external walls of buildings has been carried out comparatively based on the seasonal (space-heating and cooling and the annual energy requirements considering solar radiation effect. This study has been performed for four degree-day regions of Turkey, namely, Iskenderun (in the first region, Istanbul (in the second region, Ankara (in the third region and Ardahan (in the fourth region. By determining the sol-air temperatures for each region and maximizing the present worth value of seasonal and annual energy savings, the optimum thermal insulation thicknesses have been calculated. The effects of solar radiation on heating-cooling energy requirements, the variation of optimum insulation thicknesses and payback periods with respect to degree-day regions, the differences between the analyses based on seasonal and annual have been presented in tabular and graphical form.

  13. USE OF GAS BURNERS TYPE "DAVA" OPERATING UNDER VARIABLE LOAD TO PRODUCE HEAT AND HOT WATER

    Directory of Open Access Journals (Sweden)

    Daud V.

    2014-12-01

    Full Text Available The article brings additional information referred to upgraded gas burners type "DAVA", which are characterized by high performance at variable load. Adaptation of burner operation is carried out automatically. There are presented design features that allow increase of the efficiency and the reliability of these burners at variable load, and reducing natural gas consumption. The range of variation of the coefficient of excess air affects the efficiency of the burner. The experimental results of the tests of gas burners of different power had confirmed the economic effect of the upgraded burners at heat production. It is proved that economic effect increases with increasing of burner output and of operation time during the season.

  14. Simulation of CO2 Brayton Cycle for Engine Exhaust Heat Recovery under Various Operating Loads

    Institute of Scientific and Technical Information of China (English)

    舒歌群; 张承宇; 田华; 高媛媛; 李团兵; 仇荣赓

    2015-01-01

    A bottoming cycle system based on CO2 Brayton cycle is proposed to recover the engine exhaust heat. Its performance is compared with the conventional air Brayton cycle under five typical engine conditions. The results show that CO2 Brayton cycle proves to be superior to the air Brayton cycle in terms of the system net output power, thermal efficiency and recovery efficiency. In most cases, the recovery efficiency of CO2 Brayton cycle can be higher than 9%and the system has a better performance at the engine’s high operating load. The thermal efficiency can be as large as 24.83%under 100%operating load, accordingly, the net output power of 14.86 kW is obtained.

  15. Heat load and deuterium plasma effects on SPS and WSP tungsten

    Directory of Open Access Journals (Sweden)

    Vilémová Monika

    2015-06-01

    Full Text Available Tungsten is a prime choice for armor material in future nuclear fusion devices. For the realization of fusion, it is necessary to address issues related to the plasma–armor interactions. In this work, several types of tungsten material were studied, i.e. tungsten prepared by spark plasma sintering (SPS and by water stabilized plasma spraying (WSP technique. An intended surface porosity was created in the samples to model hydrogen/helium bubbles. The samples were subjected to a laser heat loading and a radiation loading of deuterium plasma to simulate edge plasma conditions of a nuclear fusion device (power density of 108 W/cm2 and 107 W/cm2, respectively, in the pulse intervals up to 200 ns. Thermally induced changes in the morphology and the damage to the studied surfaces are described. Possible consequences for the fusion device operation are pointed out.

  16. Investigation of damages induced by ITER-relevant heat loads during massive gas injections on Beryllium

    Directory of Open Access Journals (Sweden)

    B. Spilker

    2016-12-01

    Full Text Available Massive gas injections (MGIs will be used in ITER to mitigate the strong damaging effect of full performance plasma disruptions on the plasma facing components. The MGI method transforms the stored plasma energy to radiation that is spread across the vacuum vessel with poloidal and toroidal asymmetries. This work investigated the impact of MGI like heat loading on the first wall armor material beryllium. ITER-relevant power densities of 90-260MWm−2in combination with pulse durations of 5-10ms were exerted onto the S-65 grade beryllium specimens in the electron beam facility JUDITH 1. All tested loading conditions led to noticeable surface morphology changes and in the expected worst case scenario, a crater with thermally induced cracks with a depth of up to ∼340µm formed in the loaded area. The level of destruction in the loaded area was strongly dependent on the pulse number but also on the formation of beryllium oxide. The cyclic melting of beryllium could lead to an armor thinning mechanism under the presence of melt motion driving forces such as surface tension, magnetic forces, and plasma pressure.

  17. Volume loading augments cutaneous vasodilatation and cardiac output of heat stressed older adults.

    Science.gov (United States)

    Gagnon, Daniel; Romero, Steven A; Ngo, Hai; Sarma, Satyam; Cornwell, William K; Poh, Paula Y S; Stoller, Douglas; Levine, Benjamin D; Crandall, Craig G

    2017-08-21

    Age-related changes in cutaneous microvascular and cardiac functions limit the extent of cutaneous vasodilatation and the increase in cardiac output that healthy older adults can achieve during passive heat stress. However, it is unclear if these age-related changes in microvascular and cardiac functions maximally restrain the levels of cutaneous vasodilatation and cardiac output that healthy older adults can achieve during heat stress. We observed that rapid volume loading, performed during passive heat stress, augments both cutaneous vasodilatation and cardiac output in healthy older humans. These findings demonstrate that the microcirculation of healthy aged skin can further dilate during passive heat exposure, despite peripheral limitations to vasodilatation. Furthermore, healthy older humans can augment cardiac output when cardiac pre-load is increased during heat stress. Primary ageing markedly attenuates cutaneous vasodilatation and the increase in cardiac output during passive heating. However, it remains unclear if these responses are maximally restrained by age-related changes in cutaneous microvascular and cardiac functions. We hypothesized that rapid volume loading performed during heat stress would increase cardiac output in older adults without parallel increases in cutaneous vasodilatation. Twelve young (Y: 26 ± 5 years) and ten older (O: 69 ± 3 years) healthy adults were passively heated until core temperature increased by 1.5°C. Cardiac output (thermodilution), forearm vascular conductance (FVC, venous occlusion plethysmography) and cutaneous vascular conductance (CVC, laser-Doppler) were measured before and after rapid infusion of warmed saline (15 mL kg(-1) , ∼7 min). While heat stressed, but prior to saline infusion, cardiac output (O: 6.8 ± 0.4 vs. Y: 9.4 ± 0.6 L min(-1) ), FVC (O: 0.08 ± 0.01 vs. Y: 0.17 ± 0.02 mL (100 mL min(-1)  mmHg(-1) )(-1) ), and CVC (O: 1.29 ± 0.34 vs. Y: 1.93 ± 0.30

  18. Optimal control of a fuel cell/wind/PV/grid hybrid system with thermal heat pump load

    CSIR Research Space (South Africa)

    Sichilalu, S

    2016-10-01

    Full Text Available This paper presents an optimal energy management strategy for a grid-tied photovoltaic–wind-fuel cell hybrid power supply system. The hybrid system meets the load demand consisting of an electrical load and a heat pump water heater supplying thermal...

  19. Temperature calculations of heat loads in rotating target wheels exposed to high beam currents.

    Energy Technology Data Exchange (ETDEWEB)

    Greene, J. P.; Gabor, R.; Neubauer, J.

    2000-11-29

    In heavy-ion physics, high beam currents can eventually melt or destroy the target. Tightly focused beams on stationary targets of modest melting point will exhibit short lifetimes. Defocused or wobbled beams are employed to enhance target survival. Rotating targets using large diameter wheels can help overcome target melting and allow for higher beam currents to be used in experiments. The purpose of the calculations in this work is to try and predict the safe maximum beam currents which produce heat loads below the melting point of the target material.

  20. Simultaneous optimization of the cavity heat load and trip rates in linacs using a genetic algorithm

    Directory of Open Access Journals (Sweden)

    Balša Terzić

    2014-10-01

    Full Text Available In this paper, a genetic algorithm-based optimization is used to simultaneously minimize two competing objectives guiding the operation of the Jefferson Lab’s Continuous Electron Beam Accelerator Facility linacs: cavity heat load and radio frequency cavity trip rates. The results represent a significant improvement to the standard linac energy management tool and thereby could lead to a more efficient Continuous Electron Beam Accelerator Facility configuration. This study also serves as a proof of principle of how a genetic algorithm can be used for optimizing other linac-based machines.

  1. Inner cladding influence on large mode area photonic crystal fiber properties under severe heat load

    Science.gov (United States)

    Coscelli, Enrico; Poli, Federica; Dauliat, Romain; Darwich, Dia; Cucinotta, Annamaria; Selleri, Stefano; Schuster, Kay; Benoît, Aurélien; Jamier, Raphael; Roy, Philippe

    2016-03-01

    Constant innovations of fiber technology over the last twenty years has fueled a huge improvement of the performances of fiber lasers. Further power scaling of fiber lasers is currently hindered by the phenomenon of transverse mode instabilities, a sudden deterioration of output beam quality occurring beyond a certain power threshold due to energy transfer from the fiber fundamental mode to high-order modes. Several studies have pinpointed a thermal origin for this phenomenon. A possible solution is to implement fiber designs capable of providing a robust single-mode operation even under severe heat load, in order to prevent such coupling. In this paper the effects on the propagating modes of the change of the inner cladding size and microstructuration in double-cladding photonic crystal fibers under heating condition are discussed, and related to field confinement and single-mode regime.

  2. Analysis of Unsteady Tip and Endwall Heat Transfer in a Highly Loaded Transonic Turbine Stage

    Science.gov (United States)

    Shyam, Vikram; Ameri, Ali; Chen, Jen-Ping

    2010-01-01

    In a previous study, vane-rotor shock interactions and heat transfer on the rotor blade of a highly loaded transonic turbine stage were simulated. The geometry consists of a high pressure turbine vane and downstream rotor blade. This study focuses on the physics of flow and heat transfer in the rotor tip, casing and hub regions. The simulation was performed using the Unsteady Reynolds-Averaged Navier-Stokes (URANS) code MSU-TURBO. A low Reynolds number k-epsilon model was utilized to model turbulence. The rotor blade in question has a tip gap height of 2.1 percent of the blade height. The Reynolds number of the flow is approximately 3x10(exp 6) per meter. Unsteadiness was observed at the tip surface that results in intermittent "hot spots". It is demonstrated that unsteadiness in the tip gap is governed by inviscid effects due to high speed flow and is not strongly dependent on pressure ratio across the tip gap contrary to published observations that have primarily dealt with subsonic tip flows. The high relative Mach numbers in the tip gap lead to a choking of the leakage flow that translates to a relative attenuation of losses at higher loading. The efficacy of new tip geometry is discussed to minimize heat flux at the tip while maintaining choked conditions. In addition, an explanation is provided that shows the mechanism behind the rise in stagnation temperature on the casing to values above the absolute total temperature at the inlet. It is concluded that even in steady mode, work transfer to the near tip fluid occurs due to relative shearing by the casing. This is believed to be the first such explanation of the work transfer phenomenon in the open literature. The difference in pattern between steady and time-averaged heat flux at the hub is also explained.

  3. Experimental validation of advanced regulations for superconducting magnet cooling undergoing periodic heat loads

    Science.gov (United States)

    Lagier, B.; Rousset, B.; Hoa, C.; Bonnay, P.

    2014-01-01

    Superconducting magnets used in tokamaks undergo periodic heat load caused by cycling plasma operations inducing AC losses, neutrons fluxes and eddy currents in magnet structures. In the cryogenic system of JT60-SA tokamak, the Auxiliary Cold Box (ACB) distributes helium from the refrigerator to the cryogenic users and in particular to the superconducting magnets. ACB comprises a saturated helium bath with immersed heat exchangers, extracting heat from independent cooling loops. The supercritical helium flow in each cooling loop is driven by a cold circulator. In order to safely operate the refrigerator during plasma pulses, the interface between the ACB and the refrigerator shall be as stable as possible, with well-balanced bath inlet and outlet mass flows during cycling operation. The solution presented in this paper relies on a combination of regulations to smooth pulsed heat loads and to keep a constant refrigeration power during all the cycle. Two smoothing strategies are presented, both regulating the outlet mass flow of the bath: the first one using the bath as a thermal buffer and the second one storing energy in the loop by varying the cold circulator speed. The bath outlet mass flow is also controlled by an immersed resistive heater which enables a constant evaporation rate in the bath when power coming from the loops is decreasing. The refrigeration power is controlled so that the compensating power remains within an acceptable margin. Experimental validation is achieved using the HELIOS facility. This facility running at CEA Grenoble since 2010 is a scaled down model of the ACB bath and Central Solenoid magnet cooling loop of the JT60-SA tokamak. Test results show performances and robustness of the regulations.

  4. Experimental validation of advanced regulations for superconducting magnet cooling undergoing periodic heat loads

    Energy Technology Data Exchange (ETDEWEB)

    Lagier, B.; Rousset, B.; Hoa, C.; Bonnay, P. [CEA Grenoble INAC/SBT, 17 rue des Martyrs, 38054 Grenoble Cedex 9 (France)

    2014-01-29

    Superconducting magnets used in tokamaks undergo periodic heat load caused by cycling plasma operations inducing AC losses, neutrons fluxes and eddy currents in magnet structures. In the cryogenic system of JT60-SA tokamak, the Auxiliary Cold Box (ACB) distributes helium from the refrigerator to the cryogenic users and in particular to the superconducting magnets. ACB comprises a saturated helium bath with immersed heat exchangers, extracting heat from independent cooling loops. The supercritical helium flow in each cooling loop is driven by a cold circulator. In order to safely operate the refrigerator during plasma pulses, the interface between the ACB and the refrigerator shall be as stable as possible, with well-balanced bath inlet and outlet mass flows during cycling operation. The solution presented in this paper relies on a combination of regulations to smooth pulsed heat loads and to keep a constant refrigeration power during all the cycle. Two smoothing strategies are presented, both regulating the outlet mass flow of the bath: the first one using the bath as a thermal buffer and the second one storing energy in the loop by varying the cold circulator speed. The bath outlet mass flow is also controlled by an immersed resistive heater which enables a constant evaporation rate in the bath when power coming from the loops is decreasing. The refrigeration power is controlled so that the compensating power remains within an acceptable margin. Experimental validation is achieved using the HELIOS facility. This facility running at CEA Grenoble since 2010 is a scaled down model of the ACB bath and Central Solenoid magnet cooling loop of the JT60-SA tokamak. Test results show performances and robustness of the regulations.

  5. Modeling of limiter heat loads and impurity transport in Wendelstein 7-X startup plasmas

    Science.gov (United States)

    Effenberg, Florian; Feng, Y.; Frerichs, H.; Schmitz, O.; Hoelbe, H.; Koenig, R.; Krychowiak, M.; Pedersen, T. S.; Bozhenkov, S.; Reiter, D.

    2015-11-01

    The quasi-isodynamic stellarator Wendelstein 7-X starts plasma operation in a limiter configuration. The field consists of closed magnetic flux surfaces avoiding magnetic islands in the plasma boundary. Because of the small size of the limiters and the absence of wall-protecting elements in this phase, limiter heat loads and impurity generation due to plasma surface interaction become a concern. These issues are studied with the 3D fluid plasma edge and kinetic neutral transport code EMC3-Eirene. It is shown that the 3D SOL consists of three separate helical magnetic flux bundles of different field line connection lengths. A density scan at input power of 4MW reveals a strong modulation of the plasma paramters with the connection length. The limiter peak heat fluxes drop from 14 MWm-2 down to 10 MWm-2 with raising the density from 1 ×1018m-3 to 1.9 ×1019m-3, accompanied by an increase of the heat flux channel widths λq. Radiative power losses can help to avoid thermal overloads of the limiters at the upper margin of the heating power. The power removal feasibility of the intrinsic carbon and other extrinsic light impurities via active gas injection is discussed as a preparation of this method for island divertor operation. Work supported in part by start up funds of the Department of Engineering Physics at the University of Wisconsin - Madison, USA and by the U.S. Department of Energy under grant DE-SC0013911.

  6. Heat load behaviors of plasma sprayed tungsten coatings on copper alloys with different compliant layers

    Energy Technology Data Exchange (ETDEWEB)

    Chong, F.L. [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China)], E-mail: flch@ipp.ac.cn; Chen, J.L.; Li, J.G. [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Hu, D.Y.; Zheng, X.B. [Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200051 (China)

    2008-04-15

    Plasma sprayed tungsten (PS-W) coatings with the compliant layers of titanium (Ti), nickel-chromium-aluminum (NiCrAl) alloys and W/Cu mixtures were fabricated on copper alloys, and their properties of the porosity, oxygen content, thermal conductivity and bonding strength were measured. High heat flux tests of actively cooled W coatings were performed by means of an electron beam facility. The results indicated that APS-W coating showed a poorer heat transfer capability and thermo-mechanical properties than VPS-W coating, and the compliant layers improved W coating performance under the heat flux load. Among three compliant layers, W/Cu was the preferable because of its better effects on heat removal and stress alleviating. The optimization of W/Cu compliant layer found that 0.1 mm and 25 vol.%W was optimum compliant layer structure for 1 mm W coating, which induced a 23% reduction of the maximum stress compared to the sharp interface, and the plastic strain was reduced to 0.01% from 1.55%.

  7. Heat load behaviors of plasma sprayed tungsten coatings on copper alloys with different compliant layers

    Science.gov (United States)

    Chong, F. L.; Chen, J. L.; Li, J. G.; Hu, D. Y.; Zheng, X. B.

    2008-04-01

    Plasma sprayed tungsten (PS-W) coatings with the compliant layers of titanium (Ti), nickel-chromium-aluminum (NiCrAl) alloys and W/Cu mixtures were fabricated on copper alloys, and their properties of the porosity, oxygen content, thermal conductivity and bonding strength were measured. High heat flux tests of actively cooled W coatings were performed by means of an electron beam facility. The results indicated that APS-W coating showed a poorer heat transfer capability and thermo-mechanical properties than VPS-W coating, and the compliant layers improved W coating performance under the heat flux load. Among three compliant layers, W/Cu was the preferable because of its better effects on heat removal and stress alleviating. The optimization of W/Cu compliant layer found that 0.1 mm and 25 vol.%W was optimum compliant layer structure for 1 mm W coating, which induced a 23% reduction of the maximum stress compared to the sharp interface, and the plastic strain was reduced to 0.01% from 1.55%.

  8. Specific features of heat transfer on the external surface of smoke stacks blown by wind

    Science.gov (United States)

    Maneev, A. P.; Terekhov, V. I.

    2015-03-01

    Results of a full-scale experiment on studying heat transfer on the surface of a reinforced-concrete smoke stack blown by wind at the value of Reynolds number Re = 1.05 × 107 are presented. Comparison of the experimental results with the experimental data obtained previously by other researchers under laboratory conditions at Re cylinder in a transcritical streamlining mode. The data obtained in the present study open the possibility to estimate the average values of heat transfer coefficient on the surface of smoke stacks in a flow of atmospheric air at 4 × 106 < Re < 107.

  9. Changes in heat load profile of typical Danish multi-storey buildings when energy-renovated and supplied with low-temperature district heating

    DEFF Research Database (Denmark)

    Harrestrup, Maria; Svendsen, Svend

    2013-01-01

    end-use savings are implemented in buildings concurrent with the application of low-temperature district heating (LTDH), the heat profiles of the buildings will change. Reducing peak loads is important, since this is the dimensioning foundation for future district heating systems. To avoid oversized...... RE-based capacity, a long-term perspective needs to be taken. Applying LTDH in existing buildings without changing the heating system implies reduced radiator performance, so it is of great importance that acceptable comfort temperatures can still be provided. The results indicate that it is possible...

  10. Kinetic modeling of divertor heat load fluxes in the Alcator C-Mod and DIII-D tokamaks

    CERN Document Server

    Pankin, A Y; Kritz, A H; Park, G Y; Chang, C S; Brunner, D; Groebner, R J; Hughes, J W; LaBombard, B; Terry, J L; Ku, S

    2015-01-01

    The guiding-center kinetic neoclassical transport code, XGC0, [C.S. Chang et. al, Phys. Plasmas 11, 2649 (2004)] is used to compute the heat fluxes and the heat-load width in the outer divertor plates of Alcator C-Mod and DIII-D tokamaks. The dependence of the width of heat-load fluxes on neoclassical effects, neutral collisions and anomalous transport is investigated using the XGC0 code. The XGC0 code includes realistic X-point geometry, a neutral source model, the effects of collisions, and a diffusion model for anomalous transport. It is observed that width of the XGC0 neoclassical heat-load is approximately inversely proportional to the total plasma current $I_{\\rm p}$. The scaling of the width of the divertor heat-load with plasma current is examined for an Alcator C-Mod discharge and four DIII-D discharges. The scaling of the divertor heat-load width with plasma current is found to be weaker in the Alcator C-Mod discharge compared to scaling found in the DIII-D discharges. The effect of neutral collisio...

  11. Heat Load Measurements on a Large Superconducting Magnet An Application of a Void Fraction Meter

    CERN Document Server

    Pengo, R; Junker, S; Passardi, Giorgio; ten Kate, H H J

    2004-01-01

    ATLAS is one of the two major experiments of the LHC project at CERN using cryogenics. The superconducting magnet system of ATLAS is composed of the Barrel Toroid (BT), two End Caps Toroids and the Central Solenoid. The BT is formed of 8 race-track superconducting dipoles, each one 25 m long and 5 m wide. A reduced scale prototype (named B0) of one of the 8 dipoles, about one third of the length, has been constructed and tested in a dedicated cryogenic facility at CERN. To simulate the final thermal and hydraulic operating conditions, the B0 was cooled by a forced flow of 4.5 K saturated liquid helium provided by a centrifugal pump of 80 g/s nominal capacity. Both static and dynamic heat loads, generated by the induced currents on the B0 casing during a slow dump or a ramp up, have been measured to verify the expected thermal budget of the entire BT. The instrument used for the heat load measurements was a Void Fraction Meter (VFM) installed on the magnet return line. The instrument constructed at CERN was ca...

  12. Surface cracking of tungsten-vanadium alloys under transient heat loads

    Directory of Open Access Journals (Sweden)

    Kameel Arshad

    2015-07-01

    Full Text Available To evaluate high heat load performance of tungsten-vanadium (W-V alloys as a potential candidate for plasma facing materials of fusion devices, the target materials with three different V concentrations (1, 5 and 10 wt% are exposed to thermal shock loading. The alloys are fabricated by cold isostatic pressing and subsequently sintered in a vacuum furnace. Thereafter, they are exposed to different high heat flux densities ranging from 340 to 675 MW/m2 for single shot of 5 ms duration in an intense electron beam test facility. The alloys with lowest V concentration (1 wt% are highly damaged in form of seriously cracking. The ones with intermediate V content (5 wt% has shown comparatively better performance than both highest and lowest V contents alloys. The results indicate that improved mechanical properties and reduced thermal conductivity due to V addition comprehensively affect the cracking behavior of W-V alloy under transient thermal shock.

  13. Coupled Kinetic-MHD Simulations of Divertor Heat Load with ELM Perturbations

    Science.gov (United States)

    Cummings, Julian; Chang, C. S.; Park, Gunyoung; Sugiyama, Linda; Pankin, Alexei; Klasky, Scott; Podhorszki, Norbert; Docan, Ciprian; Parashar, Manish

    2010-11-01

    The effect of Type-I ELM activity on divertor plate heat load is a key component of the DOE OFES Joint Research Target milestones for this year. In this talk, we present simulations of kinetic edge physics, ELM activity, and the associated divertor heat loads in which we couple the discrete guiding-center neoclassical transport code XGC0 with the nonlinear extended MHD code M3D using the End-to-end Framework for Fusion Integrated Simulations, or EFFIS. In these coupled simulations, the kinetic code and the MHD code run concurrently on the same massively parallel platform and periodic data exchanges are performed using a memory-to-memory coupling technology provided by EFFIS. The M3D code models the fast ELM event and sends frequent updates of the magnetic field perturbations and electrostatic potential to XGC0, which in turn tracks particle dynamics under the influence of these perturbations and collects divertor particle and energy flux statistics. We describe here how EFFIS technologies facilitate these coupled simulations and discuss results for DIII-D, NSTX and Alcator C-Mod tokamak discharges.

  14. RELATIONSHIP BETWEEN BLOOD LACTATE AND HYPERVENTILATION DURING HIGH-INTENSITY CONSTANT-LOAD EXERCISE IN HEAT

    Directory of Open Access Journals (Sweden)

    T. Chiba

    2011-09-01

    Full Text Available The purpose of this study was to examine the relationship between hyperventilation and increase in blood lactate during high-intensity constant-load exercise in heat and normal conditions. Seven male volunteers exercised for 10 min on a cycle ergometer at 80%·VO2max in heat (40ºC, 50%relative humidity: HT and normal conditions (20ºC, 50% relative humidity: CON. Oxygen uptake, carbon dioxide output, ventilation, blood lactate and blood electrolytes (K , Na , Cl− were measured in HT and CON. We found that ventilation was significantly higher during exercise in HT compared with CON (p<0.05 and RER tends to be higher in HT than in CON. Blood lactate was significantly higher at 3 min during exercise in HT compared with CON (5.96 ± 0.57 mEq·l-1 5.00 ± 0.28 mEq·l-1, p<0.05. Change in strong ion difference [∆SID = (∆K ∆Na − (∆Cl− ∆La−], which affects ∆HCO3− in blood significantly, was lower at 5 min during exercise in HT compared with in CON (p<0.05. These results suggest that hyperventilation during exercise in heat would induce lower HCO3− in blood and consequently would result in an increase in blood lactate at an earlier time during high-intensity exercise in heat. It was concluded that hyperventilation during short-term high-intensity exercise in heat is temporarily associated with an increase in blood lactate.

  15. Zero-field steps and coherent emission of externally heated long Josephson junctions

    Science.gov (United States)

    Grib, Alexander; Seidel, Paul; Tonouchi, Masayoshi

    2017-01-01

    IV-characteristics of stacks of two inductively interacting long Josephson junctions with the homogeneous and inhomogeneous distributions of critical currents were investigated numerically. It was assumed that the inhomogeneous linear distribution of critical currents along the junction was created by heating of one end of the stack. Even zero-field steps were found in the IV-curve of the stack with the homogeneous distribution of critical currents, whereas odd zero-field steps appeared in the IV-curve of the stack with the heated end. Due to the inductive interaction between junctions in a stack of two junctions, each of the zero-field steps splits into two steps which correspond to frequencies of collective excitations in the system. Strong coherent emission was found at the step which corresponds to the frequency of in-phase oscillations.

  16. Heat and momentum transfer for magnetoconvection in a vertical external magnetic field

    Science.gov (United States)

    Zürner, Till; Liu, Wenjun; Krasnov, Dmitry; Schumacher, Jörg

    2016-11-01

    The scaling theory of Grossmann and Lohse for the turbulent heat and momentum transfer is extended to the magnetoconvection case in the presence of a (strong) vertical magnetic field. The comparison with existing laboratory experiments and direct numerical simulations in the quasistatic limit allows to restrict the parameter space to very low Prandtl and magnetic Prandtl numbers and thus to reduce the number of unknown parameters in the model. Also included is the Chandrasekhar limit for which the outer magnetic induction field B is large enough such that convective motion is suppressed and heat is transported by diffusion. Our theory identifies four distinct regimes of magnetoconvection which are distinguished by the strength of the outer magnetic field and the level of turbulence in the flow, respectively. LIMTECH Research Alliance and Research Training Group GK 1567 on Lorentz Force Velocimetry, funded by the Deutsche Forschungsgemeinschaft.

  17. Heat and momentum transfer for magnetoconvection in a vertical external magnetic field

    CERN Document Server

    Zürner, Till; Krasnov, Dmitry; Schumacher, Jörg

    2016-01-01

    The scaling theory of Grossmann and Lohse (J. Fluid Mech. 407, 27 (2000)) for the turbulent heat and momentum transfer is extended to the magnetoconvection case in the presence of a (strong) vertical magnetic field. The comparison with existing laboratory experiments and direct numerical simulations in the quasistatic limit allows to restrict the parameter space to very low Prandtl and magnetic Prandtl numbers and thus to reduce the number of unknown parameters in the model. Also included is the Chandrasekhar limit for which the outer magnetic induction field B is large enough such that convective motion is suppressed and heat is transported by diffusion. Our theory identifies four distinct regimes of magnetoconvection which are distinguished by the strength of the outer magnetic field and the level of turbulence in the flow, respectively.

  18. Propagation of combustion waves in the shell-core energetic materials with external heat losses.

    Science.gov (United States)

    Gubernov, V V; Kudryumov, V N; Kolobov, A V; Polezhaev, A A

    2017-03-01

    In this paper, the properties and stability of combustion waves propagating in the composite solid energetic material of the shell-core type are numerically investigated within the one-dimensional diffusive-thermal model with heat losses to the surroundings. The flame speed is calculated as a function of the parameters of the model. The boundaries of stability are determined in the space of parameters by solving the linear stability problem and direct integration of the governing non-stationary equations. The results are compared with the characteristics of the combustion waves in pure solid fuel. It is demonstrated that a stable travelling combustion wave solution can exist for the parameters of the model for which the flame front propagation is unstable in pure solid fuel and it can propagate several times faster even in the presence of significant heat losses.

  19. Numerical study on transient local entropy generation in pulsating turbulent flow through an externally heated pipe

    Indian Academy of Sciences (India)

    Hüseyin Yapici; Gamze Baştürk; Nesrın Kayataş; Şenay Yalçin

    2005-10-01

    This study presents an investigation of transient local entropy generation rate in pulsating turbulent flow through an externally heated pipe. The flow inlet to the pipe pulsates at a constant period and amplitude, only the velocity oscilates. rate in pulsating turbulent flow through an externally heated pipe. The flow inlet to the pipe pulsates at a constant period and amplitude, only the velocity oscilates. The simulations are extended to include different pulsating flow cases (sinusoidal flow, step flow, and saw-down flow) and for varying periods. The flow and temperature fields are computed numerically with the help of the Fluent computational fluid dynamics (CFD) code, and a computer program developed by us by using the results of the calculations performed for the flow and temperature fields. In all investigated cases, the irreversibility due to the heat transfer dominates. With the increase of flow period, the highest levels of the total entropy generation rates increase logarithmically in the case of sinusoidal and saw-down flow cases whereas they are almost constant and the highest total local entropy is also generated in the step case flow. The Merit number oscillates periodically in the pulsating flow cases along the flow time. The results of this study indicate that flow pulsation has an adverse effect on the ratio of the useful energy transfer rate to the irreversibility rate.

  20. Performance Test of Korea Heat Load Test Facility (KoHLT-EB) for the Plasma Facing Components of Fusion Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Suk-Kwon; Jin, Hyung Gon; Lee, Eo Hwak; Yoon, Jae-Sung; Lee, Dong Won [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Cho, Seungyon [National Fusion Research Institute, Daejeon (Korea, Republic of)

    2014-10-15

    The main components of the plasma facing components (PFCs) in the tokamak are the blanket first wall and divertor, which include the armour materials, the heat sink with the cooling mechanism, and the diagnostics devices for the temperature measurement. The Korea Heat Load Test facility by using electron beam (KoHLT-EB) has been operating for the plasma facing components to develop fusion engineering. This electron beam facility was constructed using a 300 kW electron gun and a cylindrical vacuum chamber. Performance tests were carried out for the calorimetric calibrations with Cu dummy mockup and for the heat load test of large Cu module. For the simulation of the heat load test of each mockup, the preliminary thermal-hydraulic analyses with ANSYS-CFX were performed. For the development of the plasma facing components in the fusion reactors, test mockups were fabricated and tested in the high heat flux test facility. To perform a beam profile test, an assessment of the possibility of electron beam Gaussian power density profile and the results of the absorbed power for that profile before the test starts are needed. To assess the possibility of a Gaussian profile, for the qualification test of the Gaussian heat load profile, a calorimeter mockup and large Cu module were manufactured to simulate real heat. For this high-heat flux test, the Korean high-heat flux test facility using an electron beam system was constructed. In this facility, a cyclic heat flux test will be performed to measure the surface heat flux, surface temperature profile, and cooling capacity.

  1. Minimization of the external heating power by long fusion power rise-up time for self-ignition access in the helical reactor FFHR2m

    Science.gov (United States)

    Mitarai, O.; Sagara, A.; Chikaraishi, H.; Imagawa, S.; Watanabe, K.; Shishkin, A. A.; Motojima, O.

    2007-11-01

    Minimization of the external heating power to access self-ignition is advantageous to increase the reactor design flexibility and to reduce the capital and operating costs of the plasma heating device in a helical reactor. In this work we have discovered that a larger density limit leads to a smaller value of the required confinement enhancement factor, a lower density limit margin reduces the external heating power and over 300 s of the fusion power rise-up time makes it possible to reach a minimized heating power. While the fusion power rise-up time in a tokamak is limited by the OH transformer flux or the current drive capability, any fusion power rise-up time can be employed in a helical reactor for reducing the thermal stresses of the blanket and shields, because the confinement field is generated by the external helical coils.

  2. Oxide segregation and melting behavior of transient heat load exposed beryllium

    Science.gov (United States)

    Spilker, B.; Linke, J.; Pintsuk, G.; Wirtz, M.

    2016-10-01

    In the experimental fusion reactor ITER, beryllium will be applied as first wall armor material. However, the ITER-like wall project at JET already experienced that the relatively low melting temperature of beryllium can easily be exceeded during plasma operation. Therefore, a detailed study was carried out on S-65 beryllium under various transient, ITER-relevant heat loads that were simulated in the electron beam facility JUDITH 1. Hereby, the absorbed power densities were in the range of 0.15-1.0 GW m-2 in combination with pulse durations of 1-10 ms and pulse numbers of 1-1000. In metallographic cross sections, the emergence of a transition region in a depth of ~70-120 µm was revealed. This transition region was characterized by a strong segregation of oxygen at the grain boundaries, determined with energy dispersive x-ray spectroscopy element mappings. The oxide segregation strongly depended on the maximum temperature reached at the end of the transient heat pulse in combination with the pulse duration. A threshold for this process was found at 936 °C for a pulse duration of 10 ms. Further transient heat pulses applied to specimens that had already formed this transition region resulted in the overheating and melting of the material. The latter occurred between the surface and the transition region and was associated with a strong decrease of the thermal conductivity due to the weakly bound grains across the transition region. Additionally, the transition region caused a partial separation of the melt layer from the bulk material, which could ultimately result in a full detachment of the solidified beryllium layers from the bulk armor. Furthermore, solidified beryllium filaments evolved in several locations of the loaded area and are related to the thermally induced crack formation. However, these filaments are not expected to account for an increase of the beryllium net erosion.

  3. Air-to-Water Heat Pumps With Radiant Delivery in Low-Load Homes

    Energy Technology Data Exchange (ETDEWEB)

    Backman, C.; German, A.; Dakin, B.; Springer, D.

    2013-12-01

    Space conditioning represents nearly 50% of average residential household energy consumption, highlighting the need to identify alternative cost-effective, energy-efficient cooling and heating strategies. As homes are better built, there is an increasing need for strategies that are particularly well suited for high performance, low load homes. ARBI researchers worked with two test homes in hot-dry climates to evaluate the in-situ performance of air-to-water heat pump (AWHP) systems, an energy efficient space conditioning solution designed to cost-effectively provide comfort in homes with efficient, safe, and durable operation. Two monitoring projects of test houses in hot-dry climates were initiated in 2010 to test this system. Both systems were fully instrumented and have been monitored over one year to capture complete performance data over the cooling and heating seasons. Results are used to quantify energy savings, cost-effectiveness, and system performance using different operating modes and strategies. A calibrated TRNSYS model was developed and used to evaluate performance in various climate regions. This strategy is most effective in tight, insulated homes with high levels of thermal mass (i.e. exposed slab floors).

  4. Air-to-Water Heat Pumps With Radiant Delivery in Low-Load Homes

    Energy Technology Data Exchange (ETDEWEB)

    Backman, C. [Alliance for Residential Building Innovation (ARBI), Davis, CA (United States); German, A. [Alliance for Residential Building Innovation (ARBI), Davis, CA (United States); Dakin, B. [Alliance for Residential Building Innovation (ARBI), Davis, CA (United States); Springer, D. [Alliance for Residential Building Innovation (ARBI), Davis, CA (United States)

    2013-12-01

    Space conditioning represents nearly 50% of average residential household energy consumption, highlighting the need to identify alternative cost-effective, energy-efficient cooling and heating strategies. As homes are better built, there is an increasing need for strategies that are particularly well suited for high performance, low load homes. ARBI researchers worked with two test homes in hot-dry climates to evaluate the in-situ performance of air-to-water heat pump systems, an energy efficient space conditioning solution designed to cost-effectively provide comfort in homes with efficient, safe, and durable operation. Two monitoring projects of test houses in hot-dry climates were initiated in 2010 to test this system. Both systems were fully instrumented and have been monitored over one year to capture complete performance data over the cooling and heating seasons. Results are used to quantify energy savings, cost-effectiveness, and system performance using different operating modes and strategies. A calibrated TRNSYS model was developed and used to evaluate performance in various climate regions. This strategy is most effective in tight, insulated homes with high levels of thermal mass (i.e. exposed slab floors).

  5. Specific Aspects Regarding Coupled Numerical Modeling of Inverter and Load Equipments in an Induction Heating Installation

    Directory of Open Access Journals (Sweden)

    Claudiu MICH-VANCEA

    2008-05-01

    Full Text Available The most propitious projection of inductiveelectrothermic installation requires a deep study ofcoupled electrothermic and circuits problems; thereforethe present paper follows the same line. Research inspecific literature have emphasized that induction heatinghas a much higher efficiency if the supply of the charge(inductor – piece is done at frequencies other thatindustrial one. [1]. Due to material alter depending ontemperature and, implicitly, the variation of the electricalparameters of the heating installation it is necessary totackle the projection of these inductive electrothermicinstallation projected through coupled numericalmodeling of the inverter circuit and of the heatingthrough induction process. The paper presents thenumerical modeling of the continuous current –alternating current conversion bridge (inverter withelements of static switch – over, the type of commandsignal (PWM of elements of static switch of power, thenumerical modeling of the heating throughelectromagnetic induction process and aspects ofcorrelation regarding the functioning/ working of theinstallation depending on the parameters of the load. Theparameters get modified due to material alter dependingon temperature during the heating process.

  6. Urban summer heat load. Meteorological data as a proxy for metropolitan biodiversity

    Energy Technology Data Exchange (ETDEWEB)

    Kappes, Heike [Naturalis Biodiversity Center, Leiden (Netherlands); Katzschner, Lutz [Kassel Univ. (Germany). Environmental Meteorological Dept.; Nowak, Carsten [Senckenberg Gesellschaft fuer Naturforschung, Gelnhausen (Germany). Conservation Genetics Section; Biodiversity and Climate Research Centre (BiK-F), Frankfurt am Main (Germany)

    2012-10-15

    Regional climate models forecast that the incidence of extreme heat waves will increase in Central Europe, and the associated intensification of urban heat islands causes concerns about human health and biodiversity. We investigated species diversity of terrestrial gastropods across an urban gradient in a metropolitan area. We considered 34 sites of different degrees of urbanization and of different thermal stress classes (TSC) that were derived from a classification of urban heat load based on the physiological equivalent temperature (PET). A total of 31 species were recorded with 0-21 species per site (mean: 4.4 {+-} 5.2 species per site). Alpha diversity was best explained by TSC, bush cover and perennial vegetation cover, and it decreased with increasing thermal stress. Overall, thermal stress predicted snail and slug species richness better than urban cover (ANOVA(analysis of variance); TSC: F = 10.0, p < 0.001; urbanization: F = 3.9, p = 0.018), and the proportional loss in species richness was higher for native species than for introduced species. The results indicate that climatic stress contributes to the impoverishment of biodiversity in urban areas. We propose that TSC and/or PET are useful indicators for environmental stress levels in biodiversity studies in natural and anthropogenically transformed landscapes. (orig.)

  7. Condensation Heat-Transfer Measurements of Refrigerants on Externally Enhanced Tubes.

    Science.gov (United States)

    1987-06-01

    fins (m 2) as Coefficient used in eqn. 5.6 At Area of smooth tube (same as Ao) (m 2) cb Fraction of tube surface flooded C, Sieder -Tate-type...modified Wilson plot method was used to process all data. The Sieder -Tate-type equation (eqn. 4.6)- was used for the inside heat-transfer coefficient. A...Flux 2.535E+04 (W/m𔃼) Tube-metal thermal conduc. 385.0 (W/m.K) Sieder -Tate constant 0.0280 UNCERTAINTY ANALYSIS: VARIABLE PERCENT UNCERTAINTY Mass

  8. INDUSTRIAL CARBON DIOXIDE HEAT PUMP STATION WITH EVAPORATORS WORKING AT VARIOUS TEMPERATURE LEVELS AND AT VARIABLE LOAD

    Directory of Open Access Journals (Sweden)

    Sit M.L.

    2010-08-01

    Full Text Available The block diagram of an industrial carbon dioxide heat pump working in a supercritical cycle, with two evaporators included in parallel working at different temperature levels (mainly for wine-making factories is developed. Heat pump is intended for simultaneous production of heat and cold and works at variable thermal loading. It is shown, how an ejector inclusion in the heat pump scheme provides growth of its thermal efficiency. The way of construction of the hydraulic scheme and a control system provides full controllability of the thermal pump.

  9. Chiral and Parity Symmetry Breaking for Planar Fermions: Effects of a Heat Bath and Uniform External Magnetic Field

    CERN Document Server

    Ayala, Alejandro; Gutierrez, Enif; Raya, Alfredo; Sanchez, Angel

    2010-01-01

    We study chiral symmetry breaking for relativistic fermions, described by a parity violating Lagrangian in 2+1-dimensions, in the presence of a heat bath and a uniform external magnetic field. Working within their four-component formalism allows for the inclusion of both parity-even and -odd mass terms. Therefore, we can define two types of fermion anti-fermion condensates. For a given value of the magnetic field, there exist two different critical temperatures which would render one of these condensates identically zero, while the other would survive. Our analysis is completely general: it requires no particular simplifying hierarchy among the energy scales involved, namely, bare masses, field strength and temperature. However, we do reproduce some earlier results, obtained or anticipated in literature, corresponding to special kinematical regimes for the parity conserving case. Relating the chiral condensate to the one-loop effective Lagrangian, we also obtain the magnetization and the pair production rate ...

  10. Technique for recovering rare-earth metals from spent sintered Nd-Fe-B magnets without external heating

    Directory of Open Access Journals (Sweden)

    Ryo Sasai

    2016-06-01

    Full Text Available To selectively recover rare-earth metals with higher purity from spent sintered Nd-Fe-B magnets without external heating, we investigated the mechano-chemical treatment of spent sintered Nd-Fe-B magnet powder with a reaction solution of HCl and (COOH2 at room temperature. The results of various experiments showed that the mechano-chemical treatment with HCl and (COOH2 is very effective for recovering the rare-earth metals contained in spent sintered Nd-Fe-B magnet powder; the recovery rate and purity of the rare-earth metals were 95.3 and 95.0 mass%, respectively, under optimal conditions ([HCl] = 0.2 mol/dm3 and [(COOH2] = 0.25 mol/dm3.

  11. Modeling the burnout of solid polydisperse fuel under the conditions of external heat transfer

    Science.gov (United States)

    Skorik, I. A.; Goldobin, Yu. M.; Tolmachev, E. M.; Gal'perin, L. G.

    2013-11-01

    A self-similar burnout mode of solid polydisperse fuel is considered taking into consideration heat transfer between fuel particles, gases, and combustion chamber walls. A polydisperse composition of fuel is taken into account by introducing particle distribution functions by radiuses obtained for the kinetic and diffusion combustion modes. Equations for calculating the temperatures of particles and gases are presented, which are written for particles average with respect to their distribution functions by radiuses taking into account the fuel burnout ratio. The proposed equations take into consideration the influence of fuel composition, air excess factor, and gas recirculation ratio. Calculated graphs depicting the variation of particle and gas temperatures, and the fuel burnout ratio are presented for an anthracite-fired boiler.

  12. Flow and heat transfer in gas turbine disk cavities subject to nonuniform external pressure field

    Energy Technology Data Exchange (ETDEWEB)

    Roy, R.P.; Kim, Y.W.; Tong, T.W. [Arizona State Univ., Tempe, AZ (United States)

    1995-10-01

    Injestion of hot gas from the main-stream gas path into turbine disk cavities, particularly the first-stage disk cavity, has become a serious concern for the next-generation industrial gas turbines featuring high rotor inlet temperature. Fluid temperature in the cavities increases further due to windage generated by fluid drag at the rotating and stationary surfaces. The resulting problem of rotor disk heat-up is exacerbated by the high disk rim temperature due to adverse (relatively flat) temperature profile of the mainstream gas in the annular flow passage of the turbine. A designer is concerned about the level of stresses in the turbine rotor disk and its durability, both of which are affected significantly by the disk temperature distribution. This distribution also plays a major role in the radial position of the blade tip and thus, in establishing the clearance between the tip and the shroud. To counteract mainstream gas ingestion as well as to cool the rotor and the stator disks, it is necessary to inject cooling air (bled from the compressor discharge) into the wheel space. Since this bleeding of compressor air imposes a penalty on the engine cycle performance, the designers of disk cavity cooling and sealing systems need to accomplish these tasks with the minimum possible amount of bleed air without risking disk failure. This requires detailed knowledge of the flow characteristics and convective heat transfer in the cavity. The flow in the wheel space between the rotor and stator disks is quite complex. It is usually turbulent and contains recirculation regions. Instabilities such as vortices oscillating in space have been observed in the flow. It becomes necessary to obtain both a qualitative understanding of the general pattern of the fluid motion as well as a quantitative map of the velocity and pressure fields.

  13. Externally heated protostellar cores in the Ophiuchus star-forming region

    CERN Document Server

    Lindberg, Johan E; Jørgensen, Jes K; Cordiner, Martin A; Bjerkeli, Per

    2016-01-01

    We present APEX 218 GHz observations of molecular emission in a complete sample of embedded protostars in the Ophiuchus star-forming region. To study the physical properties of the cores, we calculate H$_2$CO and c-C$_3$H$_2$ rotational temperatures, both of which are good tracers of the kinetic temperature of the molecular gas. We find that the H$_2$CO temperatures range between 16 K and 124 K, with the highest H$_2$CO temperatures toward the hot corino source IRAS 16293-2422 (69-124 K) and the sources in the $\\rho$ Oph A cloud (23-49 K) located close to the luminous Herbig Be star S 1, which externally irradiates the $\\rho$ Oph A cores. On the other hand, the c-C$_3$H$_2$ rotational temperature is consistently low (7-17 K) in all sources. Our results indicate that the c-C$_3$H$_2$ emission is primarily tracing more shielded parts of the envelope whereas the H$_2$CO emission (at the angular scale of the APEX beam; 3600 au in Ophiuchus) mainly traces the outer irradiated envelopes, apart from in IRAS 16293-24...

  14. Method to Estimate Long-term Change of Heat and Electric Power Daily Load Curves in Japan

    Science.gov (United States)

    Oda, Takuya; Akisawa, Atushi; Kashiwagi, Takao

    The rapid spread of CHP systems will put pressure on the regional power system to requiring an examination of the power and heat output of CHP systems. When considering the country-wide potential of the CHP system one should examine such system in coordination with the grid power system. It is essential to calculate the heat and power demand at end-use level. In the paper, annual heat and power demands of end-use sectors are forecast to the year 2025 based on 20 year data. Regression analysis is used. Estimated annual demands are divided into the seasonal hourly demands considering demand characteristics. Daily load curves of heat and power demands are determined for the Japanese end-use sectors, and the annual changes of such demands are shown by duration curves of heat to power ratios. Moreover, the grid power daily load curves are computed numerically from the estimated heat and power demands at manufacturing, residential and commercial sectors. Such load curves also consider self-generated power at manufacturing industry and own consumption of the grid power. Estimating heat and power demands allow for a joint analysis between the power system and the future phasing in of CHP systems.

  15. Numerical calculation of flow and heat transfer process in the new-type external combustion swirl-flowing hot stove

    Institute of Scientific and Technical Information of China (English)

    Shuchen Zhang; Hongzhi Guo; Xiangjun Liu; Zhangping Cai; Xiancheng Gao; Sidong Xu

    2003-01-01

    It is clarified that the important method to improve the blast temperature of the small and the middle blast furnaces whose production is about two-thirds of total sum of China from 1000℃ to 1250-1300℃ is to preheat both their combustion-supporting air and coal gas. The air temperature of blast furnaces can be reached to 1250-1300℃ by burning single blast furnace coal gas if high speed burner is applied to blast furnaces and new-type external combustion swirl-flowing hot stove is used to preheat their combustion-supporting air. The computational results of the flow and heat transfer processions in the bot stove prove that the surface of the bed of the thernal storage balls there have not eccentric flow and the flow field and temperature field distribution is even. The computational results of the blast temperature distribution are similar to those determination experiment data. The numerical results also provide references for developing and designing the new-type external combustion swirl-flowing hot stoves.

  16. Estimation of external contact loads using an inverse dynamics and optimization approach: general method and application to sit-to-stand maneuvers.

    Science.gov (United States)

    Robert, T; Causse, J; Monnier, G

    2013-09-01

    This paper presents a general method to estimate unmeasured external contact loads (ECLs) acting on a system whose kinematics and inertial properties are known. This method is dedicated to underdetermined problems, e.g. when the system has two or more unmeasured external contact wrenches. It is based on inverse dynamics and a quadratic optimization, and is therefore relatively simple, computationally cost effective and robust. Net joint loads (NJLs) are included as variables of the problem, and thus could be estimated in the same procedure as the ECL and be used within the cost function. The proposed method is tested on human sit-to-stand maneuvers performed holding a handle with one hand, i.e. asymmetrical movements with multiples external contacts. Three sets of measured and unmeasured contact load components and three cost functions are considered and simulated results are compared to experimental data. For the population and movement studied, better results are obtained for a least-square sharing between actuated degrees-of-freedom of the relative motor torques (motor torques normalized by the maximal torque production capacity). Moreover, the number of unknown ECL components does not significantly influence the results. In particular, measuring only the vertical force under the seat lead to a relatively correct estimation of the ECL and NJT: not only the values of R% were small (about 10% for the feet ECL and 20% for the NJT), but the influence of an experimental parameters (the Seat Height) was also correctly predicted.

  17. ELM simulation experiments using transient heat and particle load produced by a magnetized coaxial plasma gun

    Science.gov (United States)

    Shoda, K.; Sakuma, I.; Iwamoto, D.; Kikuchi, Y.; Fukumoto, N.; Nagata, M.

    2011-10-01

    It is considered that thermal transient events such as type I edge-localized modes (ELMs) and disruptions will limit the lifetime of plasma-facing components (PFCs) in ITER. It is predicted that the heat load onto the PFCs during type I ELMs in ITER is 0.2-2MJ/m2 with pulse length of ~0.1-1ms. We have investigated interaction between transient heat and particle load and the PFCs by using a magnetized coaxial plasma gun (MCPG) at University of Hyogo. In the experiment, a pulsed plasma with duration of ~0.5ms, incident ion energy of ~30eV, and surface absorbed energy density of ~0.3-0.7MJ/m2 was produced by the MCPG. However, no melting occurred on a tungsten surface exposed to a single plasma pulse of ~0.7MJ/m2, while cracks clearly appeared at the edge part of the W surface. Thus, we have recently started to improve the performance of the MCPG in order to investigate melt layer dynamics of a tungsten surface such as vapor cloud formation. In the modified MCPG, the capacitor bank energy for the plasma discharge is increased from 24.5 kJ to 144 kJ. In the preliminary experiments, the plasmoid with duration of ~0.6 ms, incident ion energy of ~ 40 eV, and the surface absorbed energy density of ~2 MJ/m2 was successfully produced at the gun voltage of 6 kV.

  18. Thermal models of buildings. Determination of temperatures, heating and cooling loads. Theories, models and computer programs

    Energy Technology Data Exchange (ETDEWEB)

    Kaellblad, K.

    1998-05-01

    The need to estimate indoor temperatures, heating or cooling load and energy requirements for buildings arises in many stages of a buildings life cycle, e.g. at the early layout stage, during the design of a building and for energy retrofitting planning. Other purposes are to meet the authorities requirements given in building codes. All these situations require good calculation methods. The main purpose of this report is to present the authors work with problems related to thermal models and calculation methods for determination of temperatures and heating or cooling loads in buildings. Thus the major part of the report deals with treatment of solar radiation in glazing systems, shading of solar and sky radiation and the computer program JULOTTA used to simulate the thermal behavior of rooms and buildings. Other parts of thermal models of buildings are more briefly discussed and included in order to give an overview of existing problems and available solutions. A brief presentation of how thermal models can be built up is also given and it is a hope that the report can be useful as an introduction to this part of building physics as well as during development of calculation methods and computer programs. The report may also serve as a help for the users of energy related programs. Independent of which method or program a user choose to work with it is his or her own responsibility to understand the limits of the tool, else wrong conclusions may be drawn from the results 52 refs, 22 figs, 4 tabs

  19. Generation of dried tube specimen for HIV-1 viral load proficiency test panels: a cost-effective alternative for external quality assessment programs.

    Science.gov (United States)

    Ramos, Artur; Nguyen, Shon; Garcia, Albert; Subbarao, Shambavi; Nkengasong, John N; Ellenberger, Dennis

    2013-03-01

    Participation in external quality assessment programs is critical to ensure quality clinical laboratory testing. Commercially available proficiency test panels for HIV-1 virus load testing that are used commonly in external quality assessment programs remain a financial obstacle to resource-limited countries. Maintaining cold-chain transportation largely contributes to the cost of traditional liquid proficiency test panels. Therefore, we developed and evaluated a proficiency test panel using dried tube specimens that can be shipped and stored at ambient temperature. This dried tube specimens panel consisted of 20 μl aliquots of a HIV-1 stock that were added to 2 ml tubes and left uncapped for drying, as a preservation method. The stability of dried tube specimens at concentrations ranging from 10² to 10⁶·⁵ RNA copies/ml was tested at different temperatures over time, showing no viral load reduction at 37 °C and a decrease in viral load smaller than 0.5 Log₁₀ at 45 °C for up to eight weeks when compared to initial results. Eight cycles of freezing-thawing had no effect on the stability of the dried tube specimens. Comparable viral load results were observed when dried tube specimen panels were tested on Roche CAPTAQ, Abbott m2000, and Biomerieux easyMAG viral load systems. Preliminary test results of dried proficiency test panels shipped to four African countries at ambient temperature demonstrated a low inter assay variation (SD range: 0.29-0.41 Log₁₀ RNA copies/ml). These results indicated that HIV-1 proficiency test panels generated by this methodology might be an acceptable alternative for laboratories in resource-limited countries to participate in external quality assessment programs.

  20. α-Tocopherol-loaded niosome prepared by heating method and its release behavior.

    Science.gov (United States)

    Basiri, Ladan; Rajabzadeh, Ghadir; Bostan, Aram

    2017-04-15

    α-Tocopherol-loaded niosome was developed using modified heating method. The influence of surfactants (Span60 and Tween60) in different mole ratios, presence or absence of cholesterol (Chol) and dicetyl phosphate (DCP) as well as different concentration of α-tocopherol (α-TOC) on mean size, polydispersity index, zeta potential and entrapment efficiency (EE) was evaluated. The results showed that α-TOC loaded niosomes exhibited a small mean size (73.85±0.6-186±0.58nm), narrow size distribution and high EE (61.13±0.52-98.92±0.92). By decreasing the HLB, the EE and stability of the niosomes increased. The DCP and Chol improved the physicochemical properties of niosomes. 3:1 mole ratio of Span 60:Tween 60, 4mg/ml of α-TOC and 25:12.5:2.5 mole ratio of surfactant:Chol:DCP was the optimum formulation in the encapsulation of α-TOC applying niosome system. The niosomes had sustained release profile in the simulated gastric and intestinal fluid.

  1. Thermal Energy Storage for Building Load Management: Application to Electrically Heated Floor

    Directory of Open Access Journals (Sweden)

    Hélène Thieblemont

    2016-07-01

    Full Text Available In cold climates, electrical power demand for space conditioning becomes a critical issue for utility companies during certain periods of the day. Shifting a portion or all of it to off-peak periods can help reduce peak demand and reduce stress on the electrical grid. Sensible thermal energy storage (TES systems, and particularly electrically heated floors (EHF, can store thermal energy in buildings during the off-peak periods and release it during the peak periods while maintaining occupants’ thermal comfort. However, choosing the type of storage system and/or its configuration may be difficult. In this paper, the performance of an EHF for load management is studied. First, a methodology is developed to integrate EHF in TRNSYS program in order to investigate the impact of floor assembly on the EHF performance. Then, the thermal comfort (TC of the night-running EHF is studied. Finally, indicators are defined, allowing the comparison of different EHF. Results show that an EHF is able to shift 84% of building loads to the night while maintaining acceptable TC in cold climate. Moreover, this system is able to provide savings for the customer and supplier if there is a significant difference between off-peak and peak period electricity prices.

  2. THE DEPENDENCE OF HEAT CONSUMPTION ON THE DYNAMICS OF EXTERNAL AIR TEMPERATURE DURING COLD SNAP PERIODS

    Directory of Open Access Journals (Sweden)

    Rymarov Andrey Georgievich

    2014-09-01

    Full Text Available The dynamics of outdoor temperature variations during the cold period of the year influences the operation of the systems providing the required microclimate in the premises, which may be subject to automation systems that affects the IQ of a building, it is important to note that in the last decade there has been a growth in the participation of intelligent technologies in the formation of a microclimate of buildings. Studying the microclimate quality in terms of energy consumption of the premises and the building considers climate variability and outdoor air pollution, which is connected with the economic aspects of energy efficiency and productivity, and health of workers, as a short-term temperature fall in the premises has harmful consequences. Low outdoor temperatures dry the air in the premises that requires accounting for climate control equipment and, if necessary, the personal account of its work. Excess heat in the premises, including office equipment, corrects the temperature conditions, which reduces the adverse effect of cold snap.

  3. Recrystallization and grain growth behavior of rolled tungsten under VDE-like short pulse high heat flux loads

    Science.gov (United States)

    Yuan, Y.; Greuner, H.; Böswirth, B.; Krieger, K.; Luo, G.-N.; Xu, H. Y.; Fu, B. Q.; Li, M.; Liu, W.

    2013-02-01

    Short pulse heat loads expected for vertical displacement events (VDEs) in ITER were applied in the high heat flux (HHF) test facility GLADIS at IPP-Garching onto samples of rolled W. Pulsed neutral beams with the central heat flux of 23 MW/m2 were applied for 0.5, 1.0 and 1.5 s, respectively. Rapid recrystallization of the adiabatically loaded 3 mm thick samples was observed when the pulse duration was up to 1.0 s. Grains grew markedly following recrystallization with increasing pulse length. The recrystallization temperature and temperature dependence of the recrystallized grain size were also investigated. The results showed that the recrystallization temperature of the W grade was around 2480 °C under the applied heat loading condition, which was nearly 1150 °C higher than the conventional recrystallization temperature, and the grains were much finer. A linear relationship between the logarithm of average grain size (ln d) and the inverse of maximum surface temperature (1/Tmax) was found and accordingly the activation energy for grain growth in temperature evolution up to Tmax in 1.5 s of the short pulse HHF load was deduced to be 4.1 eV. This provided an effective clue to predict the structure evolution under short pulse HHF loads.

  4. Electric Heating Property from Butyl Rubber-Loaded Boron Carbide Composites

    Institute of Scientific and Technical Information of China (English)

    MENG Dechuan; WANG Ninghui; LI Guofeng

    2014-01-01

    We researched the electric heating property from butyl rubber-loaded boron carbide composite. The effects of boron carbide content on bulk resistivity, voltage-current characteristic, thermal conductivity and thermal stability of boron carbide/butyl rubber (IIR) polymer composite were introduced. The analysis results indicated that the bulk resistivity decreased greatly with increasing boron carbide content, and when boron carbide content reached to 60%, the bulk resistivity achieved the minimum. Accordingly, electric heating behavior of the composite is strongly dependent on boron carbide content as well as applied voltage. The content of boron carbide was found to be effective in achieving high thermal conductivity in composite systems. The thermal conductivity of the composite material with added boron carbide was improved nearly 20 times than that of the pure IIR. The thermal stability test showed that, compared with pure IIR, the thermal stable time of composites was markedly extended, which indicated that the boron carbide can significantly improve the thermal stability of boron carbide/IIR composite.

  5. Tympanic temperature in confined beef cattle exposed to excessive heat load

    Science.gov (United States)

    Mader, T. L.; Gaughan, J. B.; Johnson, L. J.; Hahn, G. L.

    2010-11-01

    Angus crossbred yearling steers ( n = 168) were used to evaluate effects on performance and tympanic temperature (TT) of feeding additional potassium and sodium to steers exposed to excessive heat load (maximum daily ambient temperature exceeded 32°C for three consecutive days) during seasonal summer conditions. Steers were assigned one of four treatments: (1) control; (2) potassium supplemented (diet containing 2.10% KHCO3); (3) sodium supplemented (diet containing 1.10% NaCl); or (4) potassium and sodium supplemented (diet containing 2.10% KHCO3 and 1.10% NaCl). Overall, additional KHCO3 at the 2% level or NaCl at the 1% level did not improve performance or heat stress tolerance with these diet formulations. However, the addition of KHCO3 did enhance water intake. Independent of treatment effects, TT of cattle displaying high, moderate, or low levels of stress suggest that cattle that do not adequately cool down at night are prone to achieving greater body temperatures during a subsequent hot day. Cattle that are prone to get hot but can cool at night can keep average tympanic temperatures at or near those of cattle that tend to consistently maintain lower peak and mean body temperatures. In addition, during cooler and moderately hot periods, cattle change TT in a stair-step or incremental pattern, while under hot conditions, average TT of group-fed cattle moves in conjunction with ambient conditions, indicating that thermoregulatory mechanisms are at or near maximum physiological capacity.

  6. FLASHPOINT - a tool to routinely calculate the heat load in the irradiated fuel bays

    Energy Technology Data Exchange (ETDEWEB)

    Vyskocil, E.; Morrison, C.; Gifford, E.; Inglot, A.; Kozlowski, K.; Gocmanac, M. [AMEC NSS, Reactor and Radiation Physics, Toronto, Ontario (Canada); Parlatan, Y. [Ontario Power Generation, Safety Analysis Improvement Project Dept., Pickering, Ontario (Canada); Alabasha, H. [Bruce Power, Nuclear Safety Analysis and Support, Toronto, Ontario (Canada)

    2013-07-01

    At the recommendation of the World Association of Nuclear Operators (WANO), a tool was developed as an enhancement of NuFLASH (Nuclear Fuel Location and Storage History) in order to routinely calculate the Irradiated Fuel Bay (IFB) heat load. It uses information stored in NuFLASH regarding the location and details of spent fuel bundle properties to calculate the decay power on a bundle by bundle basis and then sum the decay powers of all bundles in a particular IFB. FLASHPOINT employs a two-step approximation of the bundle irradiation history based on the record of the life cycle for each individual fuel bundle. The primary parameter affecting the decay power of any individual irradiated CANDU fuel bundle following its discharge from core is the period of time elapsed since the bundle last operated at power within the reactor. The remaining factors influencing the decay power of an individual fuel bundle concern the irradiation history of that bundle while in core. The accuracy of the FLASHPOINT methodology has been assessed primarily through comparison of results obtained using the two step history representation implemented in FLASHPOINT against results from a more detailed ORIGEN-S calculation of the decay heat based on the SORO power history for a randomly selected sample of bundles. The results for individual bundles and the aggregate group are presented and the accuracy of the two-step approximation is demonstrated to be acceptable. (author)

  7. Revised Heating Load Line Analysis: Addendum to ORNL/TM-2015/281

    Energy Technology Data Exchange (ETDEWEB)

    Rice, C. Keith [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Shen, Bo [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Shrestha, Som S. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2016-07-01

    The original heating load line analysis of ORNL TM-2015/281 was modified to incorporate two adjustments of (1) removing mechanical ventilation and (2) resizing the heat pump units based on new criteria. This resulted in a lowering of the HLL slope factor from the originally rounded 1.3 level to 1.15 in DOE Region IV and V while leaving unchanged the zero-load ambient at a rounded value of 55 F. For the other four DOE regions, the zero-load ambients dropped by 1 to 2 F from those found earlier and the rounded HLL slope factors ranged from 1.05 to 1.3. The average rounded HLL slope factor over all six DOE regions is 1.15. Effects of the revised slope factor on rated HSPFs (Region IV) for single- and two-capacity units dropped from 16% in the original work to 12.6% in this report. For VS units, the HSPF reductions of 14 to 25% in the original report were lowered to a range of 9 to 21%. As in the original report, for VS units that do not limit minimum speed operation below 47 F ambient, the average HSPF reduction for the cases evaluated is approximately the same as for single- and two-capacity units. For VS units that do limit minimum speed operation below 47 F ambient, the lower 1.15 slope factor of this report generally results in small overpredictions of rated HSPF by 1 to 3% compared to functional HSPF. An exception is minimum-speed-limited VS units where the minimum speed COP at 47 F is higher than that at 62 F; one such unit was found to have an HSPF overprediction of over 14% with the 1.15 HLL slope factor level. For such VS exception cases, a default HSPF penalty should be considered. For the more typical VS units that limit minimum speed operation, use of a 1.15 slope factor for rated HSPF was found to still acceptably limit the HSPF error. If slope factors lower than 1.15 are used for HSPF ratings, some means should be considered to appropriately derate the HSPFs for VS units which limit minimum speed operation below 47 F ambient.

  8. Natural gas pyrolysis in double-walled reactor tubes using thermal plasma or concentrated solar radiation as external heating source

    Institute of Scientific and Technical Information of China (English)

    Stèphane Abanades; Stefania Tescari; Sylvain Rodat; Gilles Flamant

    2009-01-01

    The thermal pyrolysis of natural gas as a clean hydrogen production route is examined.The concept of a double-walled reactor tube is proposed and implemented.Preliminary experiments using an external plasma heating source are carded out to validate this concept.The results point out the efficient CH4 dissociation above 1850 K (CH4 conversion over 90%) and the key influence of the gas residence time.Simulations are performed to predict the conversion rate of CH4 at the reactor outlet,and are consistent with experimental tendencies.A solar reactor prototype featuring four independent double-walled tubes is then developed.The heat in high temperature process required for the endothermic reaction of natural gas pyrolysis is supplied by concentrated solar energy.The tubes are heated uniformly by radiation using the blackbody effect of a cavity-receiver absorbing the concentrated solar irradiation through a quartz window.The gas composition at the reactor outlet,the chemical conversion of CH4,and the yield to H2 are determined with respect to reaction temperature,inlet gas flow-rates,and feed gas composition.The longer the gas residence time,the higher the CH4 conversion and H2 yield,whereas the lower the amount of acetylene.A CH4 conversion of 99% and H2 yield of about 85% are measured at 1880 K with 30% CH4 in the feed gas (6 L/min injected and residence time of 18 ms).A temperature increase from 1870 K to 1970 K does not improve the H2 yield.

  9. How low can the low heating load density district heating be? Environmental aspects on low heating load density district heating of the present generation compared to a domestic oil burner; Hur vaermegles kan den vaermeglesa fjaerrvaermen vara? Miljoeaspekter paa vaermegles fjaerrvaerme med dagens teknik jaemfoerd med villaoljepanna

    Energy Technology Data Exchange (ETDEWEB)

    Froeling, Morgan [Chalmers Univ. of Technology, Goeteborg (Sweden). Dept. of Chemical Environmental Science

    2005-07-01

    In Sweden we can see an increase of district heating networks in residential areas with low heat density. For the customer the economy is normally the most important argument when deciding to choose district heating. For many customers, however, arguments regarding environmental friendliness are important complimentary arguments. When district heating systems are built with decreased heat density, the environmental impacts from use of district heating will increase, depending on such as increased need of pipes and increased heat losses from the distribution system. The purpose of this study is to investigate if there is a limit, a lowest heat density when it is not any longer beneficial to build district heating when district heating replaces local oil furnace heating. Life cycle inventory data for district heating distribution systems in areas with low heat density has been compared with the use of oil furnaces. The environmental impacts are categorized into Global Warming Potential, Acidification Potential, Eutrofication Potential and Use of Finite Resources. To enhance the assessment three single point indicators have also been used: EcoIndicator99, EPS and ExternE. The economics of using district heating in areas with low heat density has not been regarded in this study. A model comparing the space heating of a single family home with an oil furnace or with district heating has been created. The home has an annual heat need of 20 MWh. The district heating distribution network is characterized by its linear heat density. The linear heat density is a rough description of a district heating network, and thus also the results from the model will be general. Still it can give us a general idea of the environmental limit for district heating in areas with low heat density. An assessment of all results indicate that with the type of technology used at present it is not environmentally beneficial to use district heating with lower linear heat density than 0,2 MWh/m. At

  10. Analysis of Entropy Generation of Combined Heat and Mass Transfer in Internal and External Flows with the Assumption of Local Thermodynamic Equilibrium

    Institute of Scientific and Technical Information of China (English)

    ShouguangYao

    1994-01-01

    In this paper,the control volume method is used to establish the general expression of entropy generation due to combined convective heat and mass transfer in internal and external fluid streams.The expression accounts for irreversibilities due to the presence of heat transfer across a finite temperature difference,mass transfer across a finite difference in the chemical potential of a species,and due to flow friction.Based on the assumption of local thermodynamic equilibrium,the generalized form of the Gibbs equation is used in this analysis.The results are applied to two fundamental problems of forced convection heat and mass transfer in internal and external flows.After minimizing the entropy generation,useful conclusions are derived that are typical of the second law viewpoint for the definition of the optimum operation conditions for the specified applications.which is a valuable criterion for optimum design of heat and fluid flow devices.

  11. Recrystallization and grain growth behavior of rolled tungsten under VDE-like short pulse high heat flux loads

    Energy Technology Data Exchange (ETDEWEB)

    Yuan, Y. [Laboratory of Advanced Materials, Department of Material Science and Engineering, Tsinghua University, Beijing 100084 (China); Greuner, H.; Böswirth, B.; Krieger, K. [Max-Planck-Institut für Plasmaphysik, EURATOM Association, 85748 Garching (Germany); Luo, G.-N. [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, Anhui 230031 (China); Xu, H.Y.; Fu, B.Q.; Li, M. [Laboratory of Advanced Materials, Department of Material Science and Engineering, Tsinghua University, Beijing 100084 (China); Liu, W., E-mail: liuw@mail.tsinghua.edu.cn [Laboratory of Advanced Materials, Department of Material Science and Engineering, Tsinghua University, Beijing 100084 (China)

    2013-02-15

    Highlights: ► Recrystallization temperature of a rolled W was ∼2480 °C under applied HHF loads. ► Fine grains were obtained under HHF loads with appropriate short pulse length. ► With increasing pulse length, the recrystallized grains significantly grew larger. ► A linear relationship between ln d and 1/T{sub max} was found. ► Activation energy for grain growth in T evolution up to T{sub max} in 1.5 s was obtained. -- Abstract: Short pulse heat loads expected for vertical displacement events (VDEs) in ITER were applied in the high heat flux (HHF) test facility GLADIS at IPP-Garching onto samples of rolled W. Pulsed neutral beams with the central heat flux of 23 MW/m{sup 2} were applied for 0.5, 1.0 and 1.5 s, respectively. Rapid recrystallization of the adiabatically loaded 3 mm thick samples was observed when the pulse duration was up to 1.0 s. Grains grew markedly following recrystallization with increasing pulse length. The recrystallization temperature and temperature dependence of the recrystallized grain size were also investigated. The results showed that the recrystallization temperature of the W grade was around 2480 °C under the applied heat loading condition, which was nearly 1150 °C higher than the conventional recrystallization temperature, and the grains were much finer. A linear relationship between the logarithm of average grain size (ln d) and the inverse of maximum surface temperature (1/T{sub max}) was found and accordingly the activation energy for grain growth in temperature evolution up to T{sub max} in 1.5 s of the short pulse HHF load was deduced to be 4.1 eV. This provided an effective clue to predict the structure evolution under short pulse HHF loads.

  12. Heat loads on JET plasma facing components from ICRF and LH wave absorption in the SOL

    Science.gov (United States)

    Jacquet, P.; Colas, L.; Mayoral, M.-L.; Arnoux, G.; Bobkov, V.; Brix, M.; Coad, P.; Czarnecka, A.; Dodt, D.; Durodie, F.; Ekedahl, A.; Frigione, D.; Fursdon, M.; Gauthier, E.; Goniche, M.; Graham, M.; Joffrin, E.; Korotkov, A.; Lerche, E.; Mailloux, J.; Monakhov, I.; Noble, C.; Ongena, J.; Petrzilka, V.; Portafaix, C.; Rimini, F.; Sirinelli, A.; Riccardo, V.; Vizvary, Z.; Widdowson, A.; Zastrow, K.-D.; EFDA Contributors, JET

    2011-10-01

    In JET, lower hybrid (LH) and ion cyclotron resonance frequency (ICRF) wave absorption in the scrape-off layer can lead to enhanced heat fluxes on some plasma facing components (PFCs). Experiments have been carried out to characterize these heat loads in order to: (i) prepare JET operation with the Be wall which has a reduced power handling capability as compared with the carbon wall and (ii) better understand the physics driving these wave absorption phenomena and propose solutions for next generation systems to reduce them. When using ICRF, hot spots are observed on the antenna structures and on limiters close to the powered antennas and are explained by acceleration of ions in RF-rectified sheath potentials. High temperatures up to 800 °C can be reached on locations where a deposit has built up on tile surfaces. Modelling which takes into account the fast thermal response of surface layers can reproduce well the surface temperature measurements via infrared (IR) imaging, and allow evaluation of the heat fluxes local to active ICRF antennas. The flux scales linearly with the density at the antenna radius and with the antenna voltage. Strap phasing corresponding to wave spectra with lower kpar values can lead to a significant increase in hot spot intensity in agreement with antenna modelling that predicts, in that case, an increase in RF sheath rectification. LH absorption in front of the antenna through electron Landau damping of the wave with high Npar components generates hot spots precisely located on PFCs magnetically connected to the launcher. Analysis of the LH hot spot surface temperature from IR measurements allows a quantification of the power flux along the field lines: in the worst case scenario it is in the range 15-30 MW m-2. The main driving parameter is the LH power density along the horizontal rows of the launcher, the heat fluxes scaling roughly with the square of the LH power density. The local electron density in front of the grill increases

  13. Enhancement of urban heat load through social inequalities on an example of a fictional city King's Landing

    Science.gov (United States)

    Žuvela-Aloise, M.

    2017-03-01

    The numerical model MUKLIMO_3 is used to simulate the urban climate of an imaginary city as an illustrative example to demonstrate that the residential areas with deprived socio-economic conditions can exhibit an enhanced heat load at night, and thus more disadvantageous environmental conditions, compared with the areas of higher socio-economic status. The urban climate modelling simulations differentiate between orographic, natural landscape, building and social effects, where social differences are introduced by selection of location, building type and amount of vegetation. The model results show that the increase of heat load can be found in the areas inhabited by the poor population as a combined effect of natural and anthropogenic factors. The unfavourable location in the city and the building type, consisting of high density, low housing with high fraction of pavement and small amount of vegetation contribute to the formation of excessive heat load. This abstract example shows that the enhancement of urban heat load can be linked to the concept of a socially stratified city and is independent of the historical development of any specific city.

  14. Behavioural evidence for heat-load problems in Great Knots in tropical Australia fuelling for long-distance flight

    NARCIS (Netherlands)

    Battley, PF; Rogers, DI; Piersma, T; Koolhaas, A; Battley, Phil F.; Rogers, Danny I.

    2003-01-01

    Migratory shorebirds that live in the tropics prior to embarking on long (> 5000 km) flights may face heat-load problems. The behaviour of a large sandpiper, the Great Knot (Calidris tenuirostris), was studied in Roebuck Bay, north-west Australia, from February to April 2000. We determined the incid

  15. Potential Remedies for the High Synchrotron-Radiation-Induced Heat Load for Future Highest-Energy-Proton Circular Colliders

    Science.gov (United States)

    Cimino, R.; Baglin, V.; Schäfers, F.

    2015-12-01

    We propose a new method for handling the high synchrotron radiation (SR) induced heat load of future circular hadron colliders (like FCC-hh). FCC-hh are dominated by the production of SR, which causes a significant heat load on the accelerator walls. Removal of such a heat load in the cold part of the machine, as done in the Large Hadron Collider, will require more than 100 MW of electrical power and a major cooling system. We studied a totally different approach, identifying an accelerator beam screen whose illuminated surface is able to forward reflect most of the photons impinging onto it. Such a reflecting beam screen will transport a significant part of this heat load outside the cold dipoles. Then, in room temperature sections, it could be more efficiently dissipated. Here we will analyze the proposed solution and address its full compatibility with all other aspects an accelerator beam screen must fulfill to keep under control beam instabilities as caused by electron cloud formation, impedance, dynamic vacuum issues, etc. If experimentally fully validated, a highly reflecting beam screen surface will provide a viable and solid solution to be eligible as a baseline design in FCC-hh projects to come, rendering them more cost effective and sustainable.

  16. Potential Remedies for the High Synchrotron-Radiation-Induced Heat Load for Future Highest-Energy-Proton Circular Colliders

    CERN Document Server

    AUTHOR|(CDS)2084568; Baglin, Vincent; Schaefers, Franz

    2015-01-01

    We propose a new method for handling the high synchrotron radiation (SR) induced heat load of future circular hadron colliders (like FCC-hh). FCC-hh are dominated by the production of SR, which causes a significant heat load on the accelerator walls. Removal of such a heat load in the cold part of the machine, as done in the Large Hadron Collider, will require more than 100 MW of electrical power and a major cooling system. We studied a totally different approach, identifying an accelerator beam screen whose illuminated surface is able to forward reflect most of the photons impinging onto it. Such a reflecting beam screen will transport a significant part of this heat load outside the cold dipoles. Then, in room temperature sections, it could be more efficiently dissipated. Here we will analyze the proposed solution and address its full compatibility with all other aspects an accelerator beam screen must fulfill to keep under control beam instabilities as caused by electron cloud formation, impedance, dynamic...

  17. Enhancement of urban heat load through social inequalities on an example of a fictional city King's Landing

    Science.gov (United States)

    Žuvela-Aloise, M.

    2016-08-01

    The numerical model MUKLIMO_3 is used to simulate the urban climate of an imaginary city as an illustrative example to demonstrate that the residential areas with deprived socio-economic conditions can exhibit an enhanced heat load at night, and thus more disadvantageous environmental conditions, compared with the areas of higher socio-economic status. The urban climate modelling simulations differentiate between orographic, natural landscape, building and social effects, where social differences are introduced by selection of location, building type and amount of vegetation. The model results show that the increase of heat load can be found in the areas inhabited by the poor population as a combined effect of natural and anthropogenic factors. The unfavourable location in the city and the building type, consisting of high density, low housing with high fraction of pavement and small amount of vegetation contribute to the formation of excessive heat load. This abstract example shows that the enhancement of urban heat load can be linked to the concept of a socially stratified city and is independent of the historical development of any specific city.

  18. Potential Remedies for the High Synchrotron-Radiation-Induced Heat Load for Future Highest-Energy-Proton Circular Colliders.

    Science.gov (United States)

    Cimino, R; Baglin, V; Schäfers, F

    2015-12-31

    We propose a new method for handling the high synchrotron radiation (SR) induced heat load of future circular hadron colliders (like FCC-hh). FCC-hh are dominated by the production of SR, which causes a significant heat load on the accelerator walls. Removal of such a heat load in the cold part of the machine, as done in the Large Hadron Collider, will require more than 100 MW of electrical power and a major cooling system. We studied a totally different approach, identifying an accelerator beam screen whose illuminated surface is able to forward reflect most of the photons impinging onto it. Such a reflecting beam screen will transport a significant part of this heat load outside the cold dipoles. Then, in room temperature sections, it could be more efficiently dissipated. Here we will analyze the proposed solution and address its full compatibility with all other aspects an accelerator beam screen must fulfill to keep under control beam instabilities as caused by electron cloud formation, impedance, dynamic vacuum issues, etc. If experimentally fully validated, a highly reflecting beam screen surface will provide a viable and solid solution to be eligible as a baseline design in FCC-hh projects to come, rendering them more cost effective and sustainable.

  19. Effect of second-phase particles on the properties of W-based materials under high-heat loading

    Directory of Open Access Journals (Sweden)

    Xiao–Yue Tan

    2016-12-01

    Full Text Available W, W-TaC, and W-TiC materials were subjected to heat–load tests in an electron beam facility (10keV, 8kW at 100 pulses. After heat loading, severe cracks and plastic deformation were detected on the surface of pure W materials. However, plastic deformation was the primary change on the surfaces of W-TaC and W-TiC alloys. This phenomenon was due to the second-phase (TaC and TiC particles dispersed in the W matrix, which strengthened the grain boundaries and prevented crack formation and propagation. In addition, the microhardness of W and W-TiC obviously decreased, whereas that of W-TaC did not change considerably before and after heat loading.

  20. The influence of external dynamic loads on the lifetime of rolling element bearings: Experimental analysis of the lubricant film and surface wear

    Science.gov (United States)

    Jacobs, William; Van Hooreweder, Brecht; Boonen, Rene; Sas, Paul; Moens, David

    2016-06-01

    Precise prediction of the lifetime of rolling element bearings is a crucial step towards a reliable design of many rotating machines. For bearings subjected to highly varying loads, recent research emphasises a strong reduction of the actual bearing lifetime w.r.t. the classically calculated bearing lifetime. This paper experimentally analyses the influence of external dynamic loads on the lifetime of rolling element bearings. A novel bearing test rig is introduced. The test rig is able to apply a fully controlled multi-axial static and dynamic load on a single test bearing. Also, different types and sizes of bearings can be tested. Two separate investigations are conducted. First, the behaviour of the lubricant film between the rolling elements and raceways is analysed. Increased metallic contact or breakdown of the film during dynamic excitation is investigated based on the measured electrical resistance through the bearing. The study shows that the lubricant film thickness follows the imposed variations of the load. Variations of the lubricant film thickness are similar to the variations when the magnitude of the static bearing load is changed. Second, wear of the raceway surfaces is analysed. Surface wear is investigated after a series of accelerated lifetime tests under high dynamic load. Due to sliding motion between asperities of the contacting surfaces in the bearing, polishing of the raceway honing structure occurs. This polishing is clearly observed on SEM images of the inner raceway after a test duration of only 0.5% of the calculated L10 life. Polishing wear of the surfaces, such as surface induced cracks and material delamination, is expected when the bearing is further exposed to the high dynamic load.

  1. Study of regeneration system of 300 MW power unit based on nondeaerating heat balance diagram at reduced load

    Science.gov (United States)

    Esin, S. B.; Trifonov, N. N.; Sukhorukov, Yu. G.; Yurchenko, A. Yu.; Grigor'eva, E. B.; Snegin, I. P.; Zhivykh, D. A.; Medvedkin, A. V.; Ryabich, V. A.

    2015-09-01

    More than 30 power units of thermal power stations, based on the nondeaerating heat balance diagram, successfully operate in the former Soviet Union. Most of them are power units with a power of 300 MW, equipped with HTGZ and LMZ turbines. They operate according to a variable electric load curve characterized by deep reductions when undergoing night minimums. Additional extension of the range of power unit adjustment makes it possible to maintain the dispatch load curve and obtain profit for the electric power plant. The objective of this research is to carry out estimated and experimental processing of the operating regimes of the regeneration system of steam-turbine plants within the extended adjustment range and under the conditions when the constraints on the regeneration system and its equipment are removed. Constraints concerning the heat balance diagram that reduce the power unit efficiency when extending the adjustment range have been considered. Test results are presented for the nondeaerating heat balance diagram with the HTGZ turbine. Turbine pump and feed electric pump operation was studied at a power unit load of 120-300 MW. The reliability of feed pump operation is confirmed by a stable vibratory condition and the absence of cavitation noise and vibration at a frequency that characterizes the cavitation condition, as well as by oil temperature maintenance after bearings within normal limits. Cavitation performance of pumps in the studied range of their operation has been determined. Technical solutions are proposed on providing a profitable and stable operation of regeneration systems when extending the range of adjustment of power unit load. A nondeaerating diagram of high-pressure preheater (HPP) condensate discharge to the mixer. A regeneration system has been developed and studied on the operating power unit fitted with a deaeratorless thermal circuit of the system for removing the high-pressure preheater heating steam condensate to the mixer

  2. Numerical Study on the Flow Length in an Injection Molding Process with an External Air-Heating Step

    Directory of Open Access Journals (Sweden)

    Thanh Trung Do

    2017-04-01

    Full Text Available In this study, an external gas-assisted mold temperature control combined with water cooling was applied to achieve rapid mold-surface temperature control for observing the melt flow length in the thin-wall injection molding process. Variable part-thickness values of 0.2 mm, 0.4 mm, and 0.6 mm were used. Through a simulation and experiment, the injection molding process was achieved by using ABS and stamp insert temperatures ranging from 30 to 150 °C. In the simulation, when the stamp temperature was raised from 90 to 150 °C with part thickness of 0.2 mm, 0.4 mm, and 0.6 mm, the melt flow length increased by approximately 25.0%, 19.6%, and 12.8%, respectively. When the stamp temperature was higher than the glass-transition temperature of ABS, the improvement in the melt flow length was clearer, especially in the thinner part. In the experiment, the positive effect of stamp temperature was demonstrated; however, the improvement in the melt flow length was slightly different compared with the simulation owing to the heat transfer between the hot stamp and the environment.

  3. Transient Stability Improvement for Combined Heat and Power System Using Load Shedding

    Directory of Open Access Journals (Sweden)

    Hung-Cheng Chen

    2014-01-01

    Full Text Available The purpose of the paper is to analyze and improve the transient stability of an industrial combined heat and power (CHP system in a high-tech science park in Taiwan. The CHP system installed two 161 kV/161 kV high-impendence transformers to connect with Taipower System (TPS for both decreasing the short-circuit fault current and increasing the fault critical clearing time. The transient stabilities of three types of operation modes in CHP units, 3G1S, 2G1S, and 1G1S, are analyzed. Under the 3G1S operation mode, the system frequency is immediately restored to 60 Hz after tie line tripping with the TPS. Under the 1G1S and 2G1S operation modes, the system frequencies will continuously decrease and eventually become unstable. A novel transient stability improvement approach using load shedding technique based on the change in frequency is proposed to improve the transient stability.

  4. Investigation of vacuum properties of CuCrZr alloy for high-heat-load absorber

    Science.gov (United States)

    Shueh, C.; Chan, C. K.; Chang, C. C.; Sheng, I. C.

    2017-01-01

    The Taiwan Photon Source (TPS) uses high-heat-load (HHL) absorbers to protect downstream ultrahigh-vacuum chambers from overheating. In this work, we propose to use the CuCrZr alloy (ASTM C18150) for the HHL absorber body and the ConFlat flanges. We use the throughput method to measure the thermal outgassing rate and a helium leak detector to verify the vacuum seal between the CuCrZr alloy and stainless-steel flanges. The measured outgassing rate of the CuCrZr alloy was 5.8×10-10 Pa m/s after 72 h of pumping and decreased to 2.0 × 10-10 Pa m/s after 100 h of pumping. The leak rate through the vacuum seal between a CuCrZr flange and a stainless-steel flange was less than 1 × 10-10 Pa m3/s even after mounting and unmounting the flanges ten times and baking them at 250 °C. These results indicate that CuCrZr alloy is suitable for integrating HHL components with ConFlat CuCrZr flanges for the absorption of the synchrotron radiation generated by the TPS.

  5. Limiter heat loads during the first operation of the W7-X stellarator

    Science.gov (United States)

    Wurden, Glen; Niemann, Holger; Jakubowski, Marcin; Bozhenkov, Sergey; Biedermann, Christoph; Marsen, Stefan; Effenberg, Florian; Stephey, Laurie; Schmitz, Oliver; W7-X Team

    2016-10-01

    During the first operational phase (OP1.1) of the new W7-X stellarator, five poloidal graphite limiters served as the main boundary for the plasma. There was a dedicated set of diagnostics to observe the performance of the temporary poloidal limiters and infer basic transport behavior of the 3-D helical SOL plasma. We describe IR imaging of the limiters, which resulted in observations of 1) heat flux determination as a function of time and space, 2) total energy into the limiters, 3) high-frequency helical patterns of energy bursts onto the limiters, 4) changes in surface emissivity, and 5) detection of UFO's (small-to-large dusts). These measurements were made in 2 magnetic configuration discharges (differing iota), and in ones where the power loads to the limiters were systematically modified by the use of trim coils. Observed power fractions on the limiters ranged from 40% to 20% of the 0.6 to 4 MW ECRH input powers. Acknowledgement: Funded under DOE LANS Contract DE-AC5026NA25396 and DE-SC0014210, and within the EUROfusion Consortium under Euratom Grant 633053.

  6. Affect of Air Leakage into a Thermal-Vacuum Chamber on Helium Refrigeration Heat Load

    Science.gov (United States)

    Garcia, Sam; Meagher, Daniel; Linza, Robert; Saheli, Fariborz; Vargas, Gerardo; Lauterbach, John; Reis, Carl; Ganni, Venkatarao (Rao); Homan, Jonathan

    2008-01-01

    NASA s Johnson Space Center (JSC) Building 32 houses two large thermal-vacuum chambers (Chamber A and Chamber B). Within these chambers are liquid nitrogen shrouds to provide a thermal environment and helium panels which operate at 20K to provide cryopumping. Some amount of air leakage into the chambers during tests is inevitable. This causes "air fouling" of the helium panel surfaces due to the components of the air that adhere to the panels. The air fouling causes the emittance of the helium panels to increase during tests. The increase in helium panel emittance increases the heat load on the helium refrigerator that supplies the 20K helium for those panels. Planning for thermal-vacuum tests should account for this increase to make sure that the helium refrigerator capacity will not be exceeded over the duration of a test. During a recent test conducted in Chamber B a known-size air leak was introduced to the chamber. Emittance change of the helium panels and the affect on the helium refrigerator was characterized. A description of the test and the results will be presented.

  7. Lesson from Tungsten Leading Edge Heat Load Analysis in KSTAR Divertor

    Science.gov (United States)

    Hong, Suk-Ho; Pitts, Richard Anthony; Lee, Hyeong-Ho; Bang, Eunnam; Kang, Chan-Soo; Kim, Kyung-Min; Kim, Hong-Tack; ITER Organization Collaboration; Kstar Team Team

    2016-10-01

    An important design issue for the ITER tungsten (W) divertor and in fact for all such components using metallic plasma-facing elements and which are exposed to high parallel power fluxes, is the question of surface shaping to avoid melting of leading edges. We have fabricated a series of tungsten blocks with a variety of leading edge heights (0.3, 0.6, 1.0, and 2.0 mm), from the ITER worst case to heights even beyond the extreme value tested on JET. They are mounted into adjacent, inertially cooled graphite tile installed in the central divertor region of KSTAR, within the field of view of an infra-red (IR) thermography system with a spatial resolution to 0.4 mm/pixel. Adjustment of the outer divertor strike point position is used to deposit power on the different blocks in different discharges. The measured power flux density on flat regions of the surrounding graphite tiles is used to obtain the parallel power flux, q|| impinging on the various W blocks. Experiments have been performed in Type I ELMing H-mode with Ip = 600 kA, BT = 2 T, PNBI = 3.5 MW, leading to a hot attached divertor with typical pulse lengths of 10 s. Three dimensional ANSYS simulations using q|| and assuming geometric projection of the heat flux are found to be consistent with the observed edge loading. This research was partially supported by Ministry of Science, ICT, and Future Planning under KSTAR project.

  8. Numerical Modeling of Conjugate Thermogravitational Convection in a Closed System with a Radiant Energy Source in Conditions of Convective-Radiative Heat Exchange at the External Boundary

    Directory of Open Access Journals (Sweden)

    Nee Alexander

    2016-01-01

    Full Text Available Mathematical modeling of conjugate natural convection in a closed rectangular cavity with a radiant energy source in conditions of convective-radiative heat exchange at the external boundary was conducted. The radiant energy distribution was set by the Lambert’s law. Conduction and convection processes analysis showed that the air masses flow pattern is modified slightly over the time. The temperature increases in the gas cavity, despite the heat removal from the one of the external boundary. According to the results of the integral heat transfer analysis were established that the average Nusselt number (Nuav increasing occurs up to τ = 200 (dimensionless time. Further Nuav has changed insignificantly due to the temperature field equalization near the interfaces “gas – wall”.

  9. A High-Order Theory for the Analysis of Circular Cylindrical Composite Sandwich Shells with Transversely Compliant Core Subjected to External Loads

    DEFF Research Database (Denmark)

    Rahmani, Omid; Khalili, S.M.R.; Thomsen, Ole Thybo

    2012-01-01

    , in contrast to most of the available sandwich plate and shell theories, no prior assumptions are made with respect to the displacement field in the core. Herein the displacement and the stress fields of the core material are determined through a 3D elasticity solution. The performance of the present theory......A new model based on the high order sandwich panel theory is proposed to study the effect of external loads on the free vibration of circular cylindrical composite sandwich shells with transversely compliant core, including also the calculation of the buckling loads. In the present model...... is compared with that of other sandwich theories by the presentation of comparative results obtained for several examples encompassing different material properties and geometric parameters. It is shown that the present model produce results of very high accuracy, and it is suggested that the present model...

  10. On the influence of the urban heat island on the cooling load of a school building in Athens, Greece

    Science.gov (United States)

    Bagiorgas, H. S.; Mihalakakou, G.

    2016-02-01

    The present study investigates the effect of the urban heat island (UHI) phenomenon, measured in the Greater Athens Area (GAA), on the energy consumption of a typical modern school building. The energy performance of the selected building has been calculated using an accurate, extensively validated, transient simulation model for 17 different sites of the GAA, for the summer period. Calculations showed that the urban heat island phenomenon affects remarkably the thermal behavior of the school building, as suburban areas presented much lower cooling loads. The cooling load values fluctuated between 3304.3 kWh for the rural stations and 14,585.1 kWh for the central stations (for the year 2011) or between 3206.5 kWh and 14,208.3 kWh (for the year 2012), respectively. Moreover, the mean monthly cooling load values varied between 0.4-2 kWh/m2 for the rural stations and 4-6.9 kWh/m2 for the central stations, for the selected time period. Furthermore, a neural network model was designed and developed in order to quantify the contribution of various meteorological parameters (such as the mean daily air temperature values, the mean daily solar radiation values, the average wind speed and the urban heat island intensity) to the energy consumption of the building and it was found that the urban heat island intensity is the predominant parameter, influencing remarkably the energy consumption of the typical school building.

  11. Investigations of pulsed heat loads on a forced flow supercritical helium loop. Part B: Simulation of the cryogenic circuit

    Science.gov (United States)

    Vallcorba, R.; Hitz, D.; Rousset, B.; Lagier, B.; Hoa, C.

    2012-07-01

    The VINCENTA software is applied to model the transient thermal-hydraulic flow of the HELIOS supercritical helium circuit. This cryogenic circuit is equipped with dedicated heating to simulate pulsed heat loads - See Part A for the description of the experimental set up. Currently, one of the main important problems to be solved is the control and smoothing of heat pulses in the cryogenic circuit to keep the refrigerator in stable operation. In this context, the aim of the present development is to get a predictive model for the experimental management of overall heat loads absorbed by the refrigerator as well as to better understand the associated physical phenomena. This preliminary model is validated with early experiments performed with the HELIOS test facility which is dedicated to simulate representative pulsed loads related to the Japanese tokamak JT60-SA. This article presents the first comparison between model and experiments for two JT60-SA relevant scaled down pulses: (20 s/600 s-1000 W) and (60 s/1800 s-750 W).

  12. Bone Mass Gained in Response to External Loading is Preserved for Several Weeks Following Cessation of Loading in 10 Week C57BL/6J Mice

    Science.gov (United States)

    2010-01-01

    increased BMC in the loaded bone is caused by both bone size and vBMD changes. Bone size, as reflected by periosteal circumference (PC), was increased by 18...days four-point bending on 10 week female C57BL/6J mice. The x-axis corresponds to various time points. (a) Bone mineral content (BMC), (b) Periosteal ...tibia. In the pQCT analysis of bone parameters using the lower threshold (180-730), we found that the magnitude of increase in periosteal circumference

  13. Preliminary study on heat load using calorimetric measurement during long-pulse high-performance discharges on EAST

    Science.gov (United States)

    Liu, Y. K.; Hamada, N.; Hanada, K.; Gao, X.; Liu, H. Q.; Yu, Y. W.; Qian, J. P.; Yang, L.; Xu, T. J.; Jie, Y. X.; Yao, Y.; Wang, S. S.; Xu, J. C.; Yang, Z. D.; Li, G. S.; EAST Team

    2017-04-01

    Experimental Advanced Superconducting Tokamak (EAST) aims to demonstrate steady-state advanced high-performance H-mode plasmas with an ITER-like configuration, plasma control and heating schemes. The plasma-facing components in EAST are actively cooled, providing good conditions for researching long-pulse and high-energy discharges. A long-pulse high-performance plasma discharge (#59892 discharge) of up to 103 s with a core electron temperature of up to 4.5 keV was sustained with an injected energy exceeding 0.22 GJ in the 2015–2016 experimental campaign. A calorimetric measurement utilizing the temperature increment of cooling water is carried out to calculate the heat load on the strike point region of the lower divertor during long-pulse discharges in EAST. For the long-pulse and high-energy discharges, the comparison of the measurement results for the heat load measured by divertor Langmuir probes and the calorimetry diagnostic indicates that most of the heat load is delivered to the divertor panels as plasma, not radiation, and charge exchange neutrals. The ratio of the heat load on the strike point region of the lower divertor to the total injected energy is on average 42.5% per discharge with the lower single null divertor configuration. If the radiated energy loss measured by the fast bolometer diagnostic is taken into consideration, the ratio is found to be 61.6%. The experimental results and the analysis of the physics involved in these discharges are reported and discussed.

  14. Analysis of the temperature and thermal stress in pure tungsten monoblock during heat loading and the influences of alloying and dispersion strengthening on these responses

    Energy Technology Data Exchange (ETDEWEB)

    Fukuda, Makoto, E-mail: makoto.fukuda@qse.tohoku.ac.jp [Tohoku University, 6-6-01-2 Aramaki-aza Aoba, Aobaku, Sendai, 980-8579 (Japan); Nogami, Shuhei; Guan, Wenhai; Hasegawa, Akira [Tohoku University, 6-6-01-2 Aramaki-aza Aoba, Aobaku, Sendai, 980-8579 (Japan); Muroga, Takeo [National Institute for Fusion Science, 322-6 Oroshi-cho, Gifu, 509-5292 (Japan)

    2016-06-15

    Highlights: • The heat load response of pure W and its alloys monoblock was investigated by FEA. • The effect of alloying on heat load response of W was not clearly observed. • The possibility of cracking during cooling phase after heat load was suggested. • The effects of recrystallization and irradiation embrittlement were discussed. • W alloys will show better reliability than pure W during fusion reactor operation. - Abstract: The effects of 3% Re addition and K-bubble dispersion on temperature and stress values and the distributions thereof in a W monoblock during heat loading were investigated using finite element analysis. K-doped W-3%Re exhibited the highest recrystallization resistance but showed a higher surface temperature than pure W or K-doped W during the heat loading. The effect of K-bubble dispersion and 3% Re addition on thermal stress distribution during heat loading was not clearly observed, and residual tensile stress after heat loading, which could possibly cause cracking, was observed at the top surfaces of all materials. Because of the higher strength and temperature at which recrystallization starts for the K-doped W-3%Re and K-doped W, the probability of crack formation at the top surface might be lower compared to that in pure W. The improvement in the material properties and resistance to crack initiation and propagation in W during cyclic heat loading is crucial for the design and development of plasma-facing components. This work suggests possibility of the crack formation in a pure W monoblock in the cooling phase after a 20 MW/m{sup 2} heat loading cycle and the effectiveness of K-bubble dispersion and Re addition for improving the heat loading resistance of monoblock W.

  15. External Heat Flux on Manned Transport Spacecraft with Multiple Modes and Attitudes%载人运输飞船多模式和姿态的外热流

    Institute of Scientific and Technical Information of China (English)

    卢威; 黄家荣; 钟奇

    2011-01-01

    External heat flux analysis is not only the foundation of thermal control design and thermal analysis, but also the significant thermal boundary condition for ground thermal test.Based on theoretical analysis, a spacecraft external heat flux model was developed and the heat flux was calculated in different flight modes and attitudes.In addition, the heat flux characteristics was obtained in the extreme case.The results show that heat flux increases with the augmentation of percent time in sunlight when the spacecraft is in three-axis stabilized attitude, but decreases abruptly when it turns into the yaw maneuver, and then the heat flux will decrease with the augmentation of percent time in sunlight reversely.%在理论分析的基础上,建立了飞船外热流分析模型,解算出不同飞行姿态和模式下的外热流,分析得到外热流变化规律,得出极端外热流工况.分析结果表明:当姿态为三轴稳定时,外热流随受硒因子增大而增加;由三轴稳定转为偏航机动后外热流突然减小,且随受硒因子增大而减小.

  16. Numerical study of plasma generation process and internal antenna heat loadings in J-PARC RF negative ion source

    Energy Technology Data Exchange (ETDEWEB)

    Shibata, T., E-mail: shibat@post.j-parc.jp; Ueno, A.; Oguri, H.; Ohkoshi, K.; Ikegami, K.; Takagi, A.; Asano, H.; Naito, F. [J-PARC Center, Tokai-mura, Naka-gun, Ibaraki-ken 319-1195 (Japan); Nishida, K.; Mochizuki, S.; Hatayama, A. [Keio University, Hiyoshi, Kohoku-ku, Yokohama-shi, Kanagawa-ken 223-8522 (Japan); Mattei, S.; Lettry, J. [European Organization for Nuclear Research (CERN), 1211 Geneva 23 (Switzerland)

    2016-02-15

    A numerical model of plasma transport and electromagnetic field in the J-PARC (Japan Proton Accelerator Research Complex) radio frequency ion source has been developed to understand the relation between antenna coil heat loadings and plasma production/transport processes. From the calculation, the local plasma density increase is observed in the region close to the antenna coil. Electrons are magnetized by the magnetic field line with absolute magnetic flux density 30–120 Gauss which leads to high local ionization rate. The results suggest that modification of magnetic configuration can be made to reduce plasma heat flux onto the antenna.

  17. submitter Numerical study of plasma generation process and internal antenna heat loadings in J-PARC RF negative ion source

    CERN Document Server

    Shibata, T; Mochizuki, S; Mattei, S; Lettry, J; Hatayama, A; Ueno, A; Oguri, H; Ohkoshi, K; Ikegami, K; Takagi, A; Asano, H; Naito, F

    2016-01-01

    A numerical model of plasma transport and electromagnetic field in the J-PARC (Japan Proton Accelerator Research Complex) radio frequency ion source has been developed to understand the relation between antenna coil heat loadings and plasma production/transport processes. From the calculation, the local plasma density increase is observed in the region close to the antenna coil. Electrons are magnetized by the magnetic field line with absolute magnetic flux density 30-120 Gauss which leads to high local ionization rate. The results suggest that modification of magnetic configuration can be made to reduce plasma heat flux onto the antenna.

  18. Study of a scattering shield in a high heat load monochromator

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Rong, E-mail: rh66@cornell.edu [IMCA-CAT, Hauptman-Woodward Institute (United States); Meron, Mati [CARS, The University of Chicago (United States)

    2013-07-11

    The techniques for the cooling of the first crystal of a monochromator are by now mature and are used routinely to deal with the heat loads resulting from the intense beams generated by third generation synchrotron insertion device sources. However, the thermal stability of said monochromators, which crucially depends on proper shielding of X-ray scattering off the first crystal, remains a serious consideration. This will become even more so in the near future, as many synchrotron facilities are upgrading to higher beam currents and energies. During a recent upgrade of the 17-ID beamline at the APS it was recognized that accurate simulation of the spatial distribution of the power scattered off the first crystal was essential for the understanding and remediation of the observed large temperature increase of the first crystal's scattering shield. The calculation is complex, due to the broad energy spectrum of the undulator and the prevalence of multiple X-ray scattering events within the bulk of the crystal, thus the Monte Carlo method is the natural tool for such a task. A successful simulation was developed, for the purpose of the 17-ID upgrade, and used to significantly improve the design of the first crystal's scattering shield. -- Highlights: • We use the Monte Carlo method to simulate X-ray scattering from monochromator crystals. • Scattered X-ray power on each surface of the scattering shield has been calculated. • Overheating on the original shield is well explained with simulated scattering power. • The thermal stability of the modified scattering shield is satisfactory.

  19. Qualification Program of Korea Heat Load Test Facility KoHLT-EB for ITER Plasma Facing Components

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Suk-Kwon; Park, Seoung Dae; Jin, Hyung Gon; Lee, Eo Hwak; Yoon, Jae-Sung; Lee, Dong Won [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Cho, Seungyon [National Fusion Research Institute, Daejeon (Korea, Republic of)

    2015-10-15

    The qualification tests were performed to evaluate the high heat flux test facility for the PFCs and fusion reactor materials. For the thermal fatigue test, two types of tungsten mock-ups were fabricated. The cooling performance was tested under the similar operation condition of ITER and fusion reactor. After the completion of the preliminary mockup test and facility qualification, the high heat flux test facility will assess the performance test for the various plasma facing components in fusion reactor materials. Preliminary thermo-hydraulic and performance tests were conducted using various test mockups for the plasma facing components in the high heat flux test facilities of the world. The previous heat flux tests were performed by using the graphite heater facilities in Korea. Several facilities which equipped with an electron beam as the uniform heat source were fabricated for the tokamak PFCs in the EU, Russia and US. These heat flux test facilities are utilized for a cyclic heat flux test of the PFCs. Each facility working for their own purpose in EU FZJ, US SNL, and Russia Efremov institute. For this purpose, KoHLTEB was constructed and this facility will be used for ITER TBM performance test with the small-scale and large-scale mockups, and prototype. Also, it has been used for other fusion application for developing plasma facing component (PFC) for ITER FW, tungsten divertor, and heat transfer experiment and so on under the domestic R and D program. Korea heat load test facility by using electron beam KoHLT-EB was constructed for the high heat flux test to verify the plasma facing components, including ITER TBM first wall.

  20. Comparison of the Performance of Chilled Beam with Swirl Jet and Diffuse Ceiling Air Supply: Impact of Heat Load Distribution

    DEFF Research Database (Denmark)

    Bertheussen, Bård; Mustakallio, Panu; Kosonen, Risto

    2013-01-01

    (ventilation effectiveness of 0.4) and the air flow rate had to be above minimum to safeguard the indoor air quality. The radial swirl jet of chilled beam also was not capable of creating complete mixing at high and concentrated heat load (ventilation effectiveness of 0.7)....... (L x W x H)). A window (6.5 m2) was simulated by radiant panels. Four chilled beam units were installed symmetrically on the suspended ceiling together with two exhaust vents. The diffuse ceiling inlet was made of standard perforated acoustic tiles (0.5% total degree of perforation). The room air...... temperature was controlled at 24 °C. The quality of the generated indoor environment as defined in ISO standard 7730 (2005) was assessed based on comprehensive physical measurements. The systems created Category A thermal environment in cooling situations at heat load of 50 W∙m−2 and 78 W∙m−2 (office room...

  1. Measurement of heat load density profile on acceleration grid in MeV-class negative ion accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Hiratsuka, Junichi, E-mail: hiratsuka.junichi@jaea.go.jp; Hanada, Masaya; Kojima, Atsushi; Umeda, Naotaka; Kashiwagi, Mieko; Yoshida, Masafumi; Nishikiori, Ryo; Ichikawa, Masahiro; Watanabe, Kazuhiro; Tobari, Hiroyuki [Japan Atomic Energy Agency, 801-1 Mukoyama, Naka 311-0193 (Japan); Miyamoto, Kenji [Naruto University of Education, 748 Nakashima, Takashima, Naruto-cho, Naruto-shi, Tokushima 772-8502 (Japan)

    2016-02-15

    To understand the physics of the negative ion extraction/acceleration, the heat load density profile on the acceleration grid has been firstly measured in the ITER prototype accelerator where the negative ions are accelerated to 1 MeV with five acceleration stages. In order to clarify the profile, the peripheries around the apertures on the acceleration grid were separated into thermally insulated 34 blocks with thermocouples. The spatial resolution is as low as 3 mm and small enough to measure the tail of the beam profile with a beam diameter of ∼16 mm. It was found that there were two peaks of heat load density around the aperture. These two peaks were also clarified to be caused by the intercepted negative ions and secondary electrons from detailed investigation by changing the beam optics and gas density profile. This is the first experimental result, which is useful to understand the trajectories of these particles.

  2. Experimental Investigation of Heat Transfer in Separated Flow on a Highly Loaded LP Turbine Cascade

    Science.gov (United States)

    2003-03-01

    W Q e Q c Q f c Fig. 5 Heat-rate balance of a glue-on hot-film sensor The forced convective heat flux fcQ can be determined from the heat-rate...constant in x-direction, fcQ results in: )cTw(TAhfc Q −= (10) The heat generation rate by an electrical current I of the hot- film with a resistance Rw

  3. Vehicle Exhaust Waste Heat Recovery Model with Integrated Thermal Load Leveling

    Science.gov (United States)

    2015-08-01

    finned heat pipes, a high forced convection coefficient (>250 W/m2K, the high end of the range suggested by Incropera and DeWitt20), and no...20. Incropera FP, DeWitt DP. Fundamentals of heat and mass transfer. New York (NY): Wiley; 2002. 21. Heat Pipes. Advanced Cooling Technologies, Inc

  4. Human health-related externalities in energy system modelling the case of the Danish heat and power sector

    DEFF Research Database (Denmark)

    Zvingilaite, Erika

    2011-01-01

    This paper discusses methodology of energy system modelling when reduction of local externalities, such as damage to the human health from energy production-related air pollution, is in focus. Ideally, the local energy externalities should be analysed by adopting the impact pathway approach...... of ExternE study, and following the pollutants from their release to the personal uptake and resulting health effects. This would require inclusion of air pollution modelling and monetary valuation of the impacts into an energy system optimisation process. However, this approach involves a complex study...... and power sector verifies that it is cheaper for the society to include externalities in the planning of an energy system than to pay for the resulting damages later. Total health costs decrease by around 18% and total system costs decrease by nearly 4% when health externalities are included...

  5. Effect of Enhanced Air Temperature (extreme heat, and Load of Non-Linear Against the Use of Electric Power

    Directory of Open Access Journals (Sweden)

    I Ketut Wijaya

    2015-12-01

    Full Text Available Usage Electric power is very easy to do, because the infrastructure for connecting  already available and widely sold. Consumption electric power is not accompanied by the ability to recognize electric power. The average increase of electricity power in Bali in extreme weather reaches 10% in years 2014, so that Bali suffered power shortages and PLN as the manager of electric power to perform scheduling on of electric power usage. Scheduling is done because many people use electric power as the load  of fan and Air Conditioner exceeding the previous time. Load of fan, air conditioning, and computers including non-linear loads which can add heat on the conductor of electricity. Non-linear load and hot weather can lead to heat on conductor so  insulation damaged  and cause electrical short circuit. Data of electric power obtained through questionnaires, surveys, measurement and retrieve data from various parties. Fires that occurred in 2014, namely 109 events, 44 is  event caused by an electric short circuit (approximately 40%. Decrease power factors can cause losses of electricity and hot. Heat can cause and adds heat on the  conductor electric. The analysis showed  understanding electric power of the average  is 27,700 with value between 20 to 40. So an understanding of the electrical power away from the understand so that many errors because of the act own. Installation tool ELCB very necessary but very necessary provide counseling   of electricity to the community.

  6. An In-Depth Look at Ground Source Heat Pumps and Other Electric Loads in Two GreenMax Homes

    Energy Technology Data Exchange (ETDEWEB)

    Puttagunta, Srikanth [Consortium for Advanced Residential Buildings (CARB), Norwalk, CT (United States); Shapiro, Carl [Consortium for Advanced Residential Buildings (CARB), Norwalk, CT (United States)

    2012-04-01

    Building America research team Consortium for Advanced Residential Buildings (CARB) partnered with WPPI Energy to answer key research questions on in-field performance of ground-source heat pumps and lighting, appliance, and miscellaneous loads (LAMELs) through extensive field monitoring at two WPPI GreenMax demonstration homes in Wisconsin. These two test home evaluations provided valuable data on the true in-field performance of various building mechanical systems and LAMELs.

  7. Development of heat transfer coefficient model for external heated rotary kiln with low filling large particles%大颗粒低填充率外热式回转窑传热系数模型的构建

    Institute of Scientific and Technical Information of China (English)

    吴静; 李选友; 陈宝明; 高玲; 王瑞雪; 赵改菊; 王成运

    2014-01-01

    Heat transfer coefficient is one of the most crucial parameters in thermal calculation and design for an externally heated rotary kiln. Suitably designed kiln dimensions, structure and operating parameters rely on the accuracy of the employed heat transfer coefficient. For an externally heated kiln, heat transfers from an outside source to inside particles through a wall. Generally, the filling ratio in an externally heated rotary kiln is low. So, the heat transfer mechanism for large particles with a low filling ratio in an externally heated rotary kiln is quite different from that in an internally heated rotary kiln, whose filling ratio is usually more than 15 percent. Despite the existence of some achievements in particles motion behavior and heat transfer mechanisms in an internally heated rotary kiln, so far, there is no reliable heat transfer model to describe the heat transfer process between the kiln’s surface and particles in an externally heated rotary kiln with low filling large particles. As a result, the main approach of heat transfer coefficient determination is still an experimental test. On the basis of heat transfer mechanism analysis, this paper regards the heat transfer process between the kiln’s surface and large particles as consisting of heat conduction between the kiln’s surface and gas film, heat convection between the gas film and particles, and heat radiation between the kiln’s surface and particles. Finally, a mathematical model is created for the prediction of the heat transfer coefficient between the kiln’s surface and large particles. To validate the developed model, a series of experimental tests are performed. Alumina spherical grains with a diameter of 6 mm are used as testing particles. When the filling ratio is 5 percent, the heat transfer coefficients are measured in the range of 220℃-420℃ at 20℃ surface temperature intervals, corresponding to the rotary speeds of 1r/min, 2r/min, and 3r/min, respectively. The

  8. 集中供热系统不同调峰供热方式的技术经济性分析%Technical and Economic Analysis on Different Peak Heating Load Regulation Methods for District Heating System

    Institute of Scientific and Technical Information of China (English)

    张群力; 狄洪发

    2012-01-01

    本文主要分析了分布式调峰供热方式在集中供热系统应用中的技术经济性.通过节能性和经济性对比分析可知,相对于集中调峰供热方式,分布式调峰供热方式可以降低集中供热系统的供热能耗,提高承担基础负荷的集中热源的满负荷运行小时数、提高集中热源的供热效率,同时可以降低一次供热管网的初投资、减少一次供热管网的热损失.%In this paer,the technical and economic analysis on the district heating system with distributed peak heating load regulation method was given out. Compared with the district heating system with centralized peak heating load regulation method, the total heating energy consumption of the district heating system with distributed peak heating load regulation method was reduced. Meanwhile,the operation hours under full load condition and the heating efficiency of the centralized heating source of district heating system were increased,while the initial investiment and heat loss of the primary heating network were decreased.

  9. Application of powerful quasi-steady-state plasma accelerators for simulation of ITER transient heat loads on divertor surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Tereshin, V I [Institute of Plasma Physics of the NSC KIPT, Kharkov 61108 (Ukraine); Bandura, A N [Institute of Plasma Physics of the NSC KIPT, Kharkov 61108 (Ukraine); Byrka, O V [Institute of Plasma Physics of the NSC KIPT, Kharkov 61108 (Ukraine); Chebotarev, V V [Institute of Plasma Physics of the NSC KIPT, Kharkov 61108 (Ukraine); Garkusha, I E [Institute of Plasma Physics of the NSC KIPT, Kharkov 61108 (Ukraine); Landman, I [Forschungszentrum Karlsruhe, IHM, Karlsruhe 76021 (Germany); Makhlaj, V A [Institute of Plasma Physics of the NSC KIPT, Kharkov 61108 (Ukraine); Neklyudov, I M [Institute of Plasma Physics of the NSC KIPT, Kharkov 61108 (Ukraine); Solyakov, D G [Institute of Plasma Physics of the NSC KIPT, Kharkov 61108 (Ukraine); Tsarenko, A V [Institute of Plasma Physics of the NSC KIPT, Kharkov 61108 (Ukraine)

    2007-05-15

    The paper presents the investigations of high power plasma interaction with material surfaces under conditions simulating the ITER disruptions and type I ELMs. Different materials were exposed to plasma with repetitive pulses of 250 {mu}s duration, the ion energy of up to 0.6 keV, and the heat loads varying in the 0.5-25 MJ m{sup -2} range. The plasma energy transfer to the material surface versus impact load has been analysed. The fraction of plasma energy that is absorbed by the target surface is rapidly decreased with the achievement of the evaporation onset for exposed targets. The distributions of evaporated material in front of the target surface and the thickness of the shielding layer are found to be strongly dependent on the target atomic mass. The surface analysis of tungsten targets exposed to quasi-steady-state plasma accelerators plasma streams is presented together with measurements of the melting onset load and evaporation threshold, and also of erosion patterns with increasing heat load and the number of plasma pulses.

  10. Study on Improving Partial Load by Connecting Geo-thermal Heat Pump System to Fuel Cell Network

    Science.gov (United States)

    Obara, Shinya; Kudo, Kazuhiko

    Hydrogen piping, the electric power line, and exhaust heat recovery piping of the distributed fuel cells are connected with network, and operational planning is carried out. Reduction of the efficiency in partial load is improved by operation of the geo-thermal heat pump linked to the fuel cell network. The energy demand pattern of the individual houses in Sapporo was introduced. And the analysis method aiming at minimization of the fuel rate by the genetic algorithm was described. The fuel cell network system of an analysis example assumed connecting the fuel cell co-generation of five houses. When geo-thermal heat pump was introduced into fuel cell network system stated in this paper, fuel consumption was reduced 6% rather than the conventional method

  11. Predicting the conditions under which vibroacoustic resonances with external periodic loads occur in the primary coolant circuits of VVER-based NPPs

    Science.gov (United States)

    Proskuryakov, K. N.; Fedorov, A. I.; Zaporozhets, M. V.

    2015-08-01

    The accident at the Japanese Fukushima Daiichi nuclear power plant (NPP) caused by an earthquake showed the need of taking further efforts aimed at improving the design and engineering solutions for ensuring seismic resistance of NPPs with due regard to mutual influence of the dynamic processes occurring in the NPP building structures and process systems. Resonance interaction between the vibrations of NPP equipment and coolant pressure pulsations leads to an abnormal growth of dynamic stresses in structural materials, accelerated exhaustion of equipment service life, and increased number of sudden equipment failures. The article presents the results from a combined calculation-theoretical and experimental substantiation of mutual amplification of two kinds of external periodic loads caused by rotation of the reactor coolant pump (RCP) rotor and an earthquake. The data of vibration measurements at an NPP are presented, which confirm the predicted multiple amplification of vibrations in the steam generator and RCP at a certain combination of coolant thermal-hydraulic parameters. It is shown that the vibration frequencies of the main equipment may fall in the frequency band corresponding to the maximal values in the envelope response spectra constructed on the basis of floor accelerograms. The article presents the results from prediction of conditions under which vibroacoustic resonances with external periodic loads take place, which confirm the occurrence of additional earthquake-induced multiple growth of pressure pulsation intensity in the steam generator at the 8.3 Hz frequency and additional multiple growth of vibrations of the RCP and the steam generator cold header at the 16.6 Hz frequency. It is shown that at the elastic wave frequency equal to 8.3 Hz in the coolant, resonance occurs with the frequency of forced vibrations caused by the rotation of the RCP rotor. A conclusion is drawn about the possibility of exceeding the design level of equipment vibrations

  12. A contribution to the investigation of the heat load of shock absorbers of semi-active suspensions in motor vehicles

    Directory of Open Access Journals (Sweden)

    Miroslav D. Demić

    2013-10-01

    Full Text Available Dynamic simulation, based on modeling, has a significant role during the process of vehicle development. It is especially important in the first stages of vehicle design, when relevant vehicle parameters are to be defined. Shock absorbers as executive parts of vehicle semi-active suspension systems suffer thermal loads, which may result in damage and degradation of ther characteristics. Therefore,this paper shows an attempt to analyze converting of mechanical work into heat by using the dynamic simulation method. Introduction Shock absorbers are integral elements of semi-active suspension systems for vehicles (hereinafter SASS. They directly affect the active vehicle safety. The role of shock absorbers is to absorb mechanical vibrations transferred from the road and to ensure the safety of passengers in a vehicle. The kinetic energy of vehicle vibrations transforms into mechanical work or heat in shock absorbers. In practice, in the first stage of vehicle development, the shock absorber parameters are chosen from the condition of damping vibrations of vehicles, but their thermal shock loads should be also taken into account. Motor vehicles have complex dynamic characteristics manifested by spatial movement, parameters change during operation, a number of disturbing influences, backlash, friction, hysteresis, etc. The above-mentioned dynamic phenomena, especially vibration, lead to fatigue of driver and users, reduce the life of the vehicle and its systems, etc. The main objective of the system is to reduce the reliance of the above-mentioned negative effects, improving the vehicle behavior on the road and allow the exploitation of vehicles in a wide range of service conditions. Classical systems cannot satisfiy these conditions, so there was a need to introduce new suspension systems with controlled characteristics (briefly called "semi-active", or "active" systems. Oscillatory model of vehicle The differential equations of vibratory motion of

  13. Relationships Between Internal and External Training Load in Team-Sport Athletes: Evidence for an Individualized Approach.

    Science.gov (United States)

    Bartlett, Jonathan D; O'Connor, Fergus; Pitchford, Nathan; Torres-Ronda, Lorena; Robertson, Samuel J

    2017-02-01

    The aim of this study was to quantify and predict relationships between rating of perceived exertion (RPE) and GPS training-load (TL) variables in professional Australian football (AF) players using group and individualized modeling approaches. TL data (GPS and RPE) for 41 professional AF players were obtained over a period of 27 wk. A total of 2711 training observations were analyzed with a total of 66 ± 13 sessions/player (range 39-89). Separate generalized estimating equations (GEEs) and artificial-neural-network analyses (ANNs) were conducted to determine the ability to predict RPE from TL variables (ie, session distance, high-speed running [HSR], HSR %, m/min) on a group and individual basis. Prediction error for the individualized ANN (root-mean-square error [RMSE] 1.24 ± 0.41) was lower than the group ANN (RMSE 1.42 ± 0.44), individualized GEE (RMSE 1.58 ± 0.41), and group GEE (RMSE 1.85 ± 0.49). Both the GEE and ANN models determined session distance as the most important predictor of RPE. Furthermore, importance plots generated from the ANN revealed session distance as most predictive of RPE in 36 of the 41 players, whereas HSR was predictive of RPE in just 3 players and m/min was predictive of RPE in just 2 players. This study demonstrates that machine learning approaches may outperform more traditional methodologies with respect to predicting athlete responses to TL. These approaches enable further individualization of load monitoring, leading to more accurate training prescription and evaluation.

  14. 谈寒冷地区外墙保温施工要点%On external wall heat insulation construction points in cold areas

    Institute of Scientific and Technical Information of China (English)

    张跃华

    2014-01-01

    In order to accelerate the circular economy and realize the social and economic sustainable development, the paper explores the exter-nal wall heat insulation construction technique in cold areas, analyzes the technical requirements for the external wall and heat insulation, illus-trates the selection principle for the external wall and exterior heat insulation materials, and points out the materials can meet the demands for the safe long-term stability and energy-saving long-term stability.%为加快发展循环经济,实现经济社会的可持续发展,对寒冷地区外墙保温施工技术进行了探讨,分析了外墙外保温的技术要求,阐述了外墙外保温材料的选择原则、方法,指出外墙保温材料应满足安全长期稳定、节能效果长期稳定等要求。

  15. Lava heating and loading of ice sheets on early Mars: Predictions for meltwater generation, groundwater recharge, and resulting landforms

    Science.gov (United States)

    Cassanelli, James P.; Head, James W.

    2016-06-01

    Recent modeling studies of the early Mars climate predict a predominantly cold climate, characterized by the formation of regional ice sheets across the highland areas of Mars. Formation of the predicted "icy highlands" ice sheets is coincident with a peak in the volcanic flux of Mars involving the emplacement of the Late Noachian - Early Hesperian ridged plains unit. We explore the relationship between the predicted early Mars "icy highlands" ice sheets, and the extensive early flood volcanism to gain insight into the surface conditions prevalent during the Late Noachian to Early Hesperian transition period. Using Hesperia Planum as a type area, we develop an ice sheet lava heating and loading model. We quantitatively assess the thermal and melting processes involved in the lava heating and loading process following the chronological sequence of lava emplacement. We test a broad range of parameters to thoroughly constrain the lava heating and loading process and outline predictions for the formation of resulting geological features. We apply the theoretical model to a study area within the Hesperia Planum region and assess the observed geology against predictions derived from the ice sheet lava heating and loading model. Due to the highly cratered nature of the Noachian highlands terrain onto which the volcanic plains were emplaced, we predict highly asymmetrical lava loading conditions. Crater interiors are predicted to accumulate greater thicknesses of lava over more rapid timescales, while in the intercrater plains, lava accumulation occurs over longer timescales and does not reach great thicknesses. We find that top-down melting due to conductive heat transfer from supraglacial lava flows is generally limited when the emplaced lava flows are less than ∼10 m thick, but is very significant at lava flow thicknesses of ∼100 m or greater. We find that bottom-up cryosphere and ice sheet melting is most likely to occur within crater interiors where lavas

  16. Heat loads in inboard limited L-mode plasmas in TCV

    Energy Technology Data Exchange (ETDEWEB)

    Nespoli, F., E-mail: federico.nespoli@epfl.ch; Labit, B.; Furno, I.; Canal, G.P.; Fasoli, A.

    2015-08-15

    Infrared thermography is used in TCV to measure the heat flux deposited onto the graphite tiles of the inner wall. The heat flux radial profile is found to be well described by the sum of a main parallel component and a non negligible cross-field component. The latter accounts for about 20% of the deposited heat flux. The parallel component shows an enhancement around the contact point in all discharges under consideration. Main plasma parameters, such as density, current, elongation and triangularity have been varied, allowing for empirical scalings of the heat fluxes.

  17. Containment loads due to direct containment heating and associated hydrogen behavior: Analysis and calculations with the CONTAIN code

    Energy Technology Data Exchange (ETDEWEB)

    Williams, D C; Bergeron, K D; Carroll, D E; Gasser, R D; Tills, J L; Washington, K E

    1987-05-01

    One of the most important unresolved issues governing risk in many nuclear power plants involves the phenomenon called direct containment heating (DCH), in which it is postulated that molten corium ejected under high pressure from the reactor vessel is dispersed into the containment atmosphere, thereby causing sufficient heating and pressurization to threaten containment integrity. Models for the calculation of potential DCH loads have been developed and incorporated into the CONTAIN code for severe accident analysis. Using CONTAIN, DCH scenarios in PWR plants having three different representative containment types have been analyzed: Surry (subatmospheric large dry containment), Sequoyah (ice condenser containment), and Bellefonte (atmospheric large dry containment). A large number of parameter variation and phenomenological uncertainty studies were performed. Response of DCH loads to these variations was found to be quite complex; often the results differ substantially from what has been previously assumed concerning DCH. Containment compartmentalization offers the potential of greatly mitigating DCH loads relative to what might be calculated using single-cell representations of containments, but the actual degree of mitigation to be expected is sensitive to many uncertainties. Dominant uncertainties include hydrogen combustion phenomena in the extreme environments produced by DCH scenarios, and factors which affect the rate of transport of DCH energy to the upper containment. In addition, DCH loads can be aggravated by rapid blowdown of the primary system, co-dispersal of moderate quantities of water with the debris, and quenching of de-entrained debris in water; these factors act by increasing steam flows which, in turn, accelerates energy transport. It may be noted that containment-threatening loads were calculated for a substantial portion of the scenarios treated for some of the plants considered.

  18. Influence of Cooling to Heating Load Ratio on Optimal Supply Water and Air Temperatures in an Air Conditioning System

    Science.gov (United States)

    Karino, Naoki; Shiba, Takashi; Yokoyama, Ryohei; Ito, Koichi

    In planning an air conditioning system, supply water and air temperatures are important factors from the viewpoint of energy saving and cost reduction. For example, lower temperature supply water and air for space cooling reduce the coefficient of performance of a refrigeration machine, and increase the thickness of heat insulation material. However, they enable larger temperature differences, and reduce equipment sizes and power demand. It is also an important subject to evaluate the effect of the supply water and air temperatures on energy saving and cost reduction on the annual basis by considering not only cooling but also heating loads. The purposes of this paper are to propose an optimal planning method for an air conditioning system with large temperature difference, and to analyze the effect of supply water and air temperatures on the long-term economics through a numerical study for an office building. As a result, it is shown that the proposed method effectively determines supply water and air temperatures, and the influence of the cooling to heating load ratio on the long-term economics is clarified.

  19. Effect of volume loading on the Frank-Starling relation during reductions in central blood volume in heat-stressed humans

    DEFF Research Database (Denmark)

    Bundgaard-Nielsen, Morten; Wilson, T E; Seifert, Thomas

    2010-01-01

    During reductions in central blood volume while heat stressed, a greater decrease in stroke volume (SV) for a similar decrease in ventricular filling pressure, compared to normothermia, suggests that the heart is operating on a steeper portion of a Frank-Starling curve. If so, volume loading...... of heat-stressed individuals would shift the operating point to a flatter portion of the heat stress Frank-Starling curve thereby attenuating the reduction in SV during subsequent decreases in central blood volume. To investigate this hypothesis, right heart catheterization was performed in eight males.......06). However, subsequent volume loading increased SV to 143 +/- 29 ml (P = 0.003). LBNP provoked a larger decrease in SV relative to the decrease in PCWP during heating (8.6 +/- 1.9 ml mmHg(1)) compared to normothermia (4.5 +/- 3.0 ml mmHg(1), P = 0.02). After volume loading while heat stressed, the reduction...

  20. Displacement analysis of a bend plate test with mechanical loading and laser heating

    Energy Technology Data Exchange (ETDEWEB)

    Lam, P.S.

    1997-09-01

    The surface displacment of a steel plate caused by a permanent deformation as a result of local yielding was modeled by a finite element analysis. The local yielding occurs when a small area of the plate is heated by a laser beam. The calculated displacments are in good agreement with the preliminary experimental data obtained using a bend specimen with laser heating at the University of Alabama at Huntsville. It has been shown computuationally and optically that the relative displacments are less than 1mm near the laser heated area of the specimen. The results demonstrate that the experimental approach is a feasible technique for determining the residual stress under multiaxial stress field.

  1. 外载荷的B样条曲线变形%Shape modification of B-spline curve via external loads

    Institute of Scientific and Technical Information of China (English)

    程仙国; 刘伟军

    2011-01-01

    运用能量优化的思想,提出一种B样条曲线变形的新方法,可用于B样条曲线的变形.首先将B样条曲线段类比为有限单元法中线单元,并将作用在B样条曲线段的外载荷等效成线单元的端点力,分别建立B样条曲线内部能量、外载荷能量函数方程;外载荷的改变将引起B样条曲线能量的变化,通过求解一个使曲线能量的变化量为最小的优化问题,得到变形后的B样条曲线.运用该方法实现了B样条曲线的局部、整体等变形操作.%Based on the idea of energy optimization, a new method for shape modification of the B-spine curve is proposed. First, using an analogy between the B-spline curve and the curve element of finite element method, and making the external load acting on the curve be equivalent to the end force into the element, the internal energy functional equation of the B-spline curve and the energy functional equation of the load are constructed respectively. The energy change of the Bspline curve with the change of the load, a new curve is generated by solving an optimization problem of the change of the energy. Using this approach, the local or total modification of the curve can be accomplished.

  2. Impact of Urban Heat Island under the Hanoi Master Plan 2030 on Cooling Loads in Residential Buildings

    Directory of Open Access Journals (Sweden)

    Tran Hoang Hai Nam

    2015-01-01

    Full Text Available This study aims to evaluate the influence of urban heat island (UHI under the Hanoi Master Plan 2030 on the energy consumption for space cooling in residential buildings. The weather conditions under the current and future status (master plan condition simulated in the previous study (Trihamdani et al., 2014 were used and cooling loads in all the residential buildings in Hanoi over the hottest month were estimated under the simulated current and future conditions by using the building simulation program, TRNSYS (v17. Three most typical housing types in the city were selected for the simulation. The cooling loads of respective housing types were obtained in each of the districts in Hanoi. The results show that the total cooling loads over June 2010 is approximately 683 Terajoule (TJ under the current status, but it is predicted to increase to 903 TJ under the master plan condition. The increment is largely due to the increase in number of households (203 TJ or 92%, but partially due to the increase in urban temperature, i.e. UHI effect (17 TJ or 8%. The increments in new built-up areas were found to be larger than those in existing built-up areas. The cooling load in apartment is approximately half of that in detached house, which is approximately half of that in row house. Moreover, it was seen that although sensible cooling loads increased with the increase in outdoor temperature, the latent cooling loads decreased due to the decrease in absolute humidity and the increase in air temperature.

  3. Structural response of transient heat loading on a molybdenum surface exposed to low-energy helium ion irradiation

    Science.gov (United States)

    Sinclair, G.; Tripathi, J. K.; Diwakar, P. K.; Hassanein, A.

    2016-03-01

    The advancement of fusion reactor engineering is currently inhibited by the lack of knowledge surrounding the stability of plasma facing components (PFCs) in a tokamak environment. During normal operation, events of high heat loading occur periodically where large amounts of energy are imparted onto the PFC surface. Concurrently, irradiation by low-energy helium ions present in the fusion plasma can result in the synthesis of a fibre form nanostructure on the PFC surface, called ‘fuzz’. In order to understand how this heterogeneous structure evolves and deforms in response to transient heat loading, a pulsed Nd:YAG millisecond laser is used to simulate these events on a fuzz form molybdenum (Mo) surface. Performance was analysed by three metrics: nanostructure evolution, particle emission, and improvement in optical properties. Experiments performed at the upper end of the expected range for type-I edge-localized modes (ELMs) found that the helium-induced nanostructure completely disappears after 200 pulses of the laser at 1.5 MJ m-2. In situ mass loss measurements found that the amount of particles leaving the surface increases as energy density increases and the rate of emission increases with pulse count. Finally, optical properties assisted in providing a qualitative indication of fuzz density on the Mo surface; after 400 pulses at 1.5 MJ m-2, the optical reflectivity of the damaged surface is ~90% of that of a mirror polished Mo sample. These findings provide different results than previous studies done with tungsten (W), and further help illustrate the complicated nature of how transient events of high heat loading in a tokamak environment might impact the performance and lifetime of PFCs in ITER and future DEMO devices (Ueda et al 2014 Fusion Eng. Des. 89 901-6).

  4. Optimization of the RF cavity heat load and trip rates for CEBAF at 12 GeV

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, He [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Roblin, Yves R. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Freyberger, Arne P. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Krafft, Geoffrey A. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Terzic, Balsa P. [Old Dominion Univ., Norfolk, VA (United States)

    2017-05-01

    The Continuous Electron Beam Accelerator Facility at JLab has 200 RF cavities in the north linac and the south linac respectively after the 12 GeV upgrade. The purpose of this work is to simultaneously optimize the heat load and the trip rate for the cavities and to reconstruct the pareto-optimal front in a timely manner when some of the cavities are turned down. By choosing an efficient optimizer and strategically creating the initial gradients, the pareto-optimal front for no more than 15 cavities down can be re-established within 20 seconds.

  5. The updated algorithm of the Energy Consumption Program (ECP): A computer model simulating heating and cooling energy loads in buildings

    Science.gov (United States)

    Lansing, F. L.; Strain, D. M.; Chai, V. W.; Higgins, S.

    1979-01-01

    The energy Comsumption Computer Program was developed to simulate building heating and cooling loads and compute thermal and electric energy consumption and cost. This article reports on the new additional algorithms and modifications made in an effort to widen the areas of application. The program structure was rewritten accordingly to refine and advance the building model and to further reduce the processing time and cost. The program is noted for its very low cost and ease of use compared to other available codes. The accuracy of computations is not sacrificed however, since the results are expected to lie within + or - 10% of actual energy meter readings.

  6. Radiant Heating and Cooling Systems. Part two

    DEFF Research Database (Denmark)

    Kim, Kwan Woo; Olesen, Bjarne W.

    2015-01-01

    Control of the heating and cooling system needs to be able to maintain the indoor temperatures within the comfort range under the varying internal loads and external climates. To maintain a stable thermal environment, the control system needs to maintain the balance between the heat gain...

  7. Damage prediction of carbon fibre composite armoured actively cooled plasma-facing components under cycling heat loads

    Energy Technology Data Exchange (ETDEWEB)

    Chevet, G; Schlosser, J; Courtois, X; Escourbiac, F; Missirlian, M [CEA, IRFM, F-13108 Saint Paul Lez Durance (France); Herb, V; Martin, E; Camus, G [LCTS, CNRS UMR 5801, Universite Bordeaux 1, Pessac (France); Braccini, M [SIMaP, CNRS UMR 5266, Grenoble (France)], E-mail: gaelle.chevet@cea.fr

    2009-12-15

    In order to predict the lifetime of carbon fibre composite (CFC) armoured plasma-facing components in magnetic fusion devices, it is necessary to analyse the damage mechanisms and to model the damage propagation under cycling heat loads. At Tore Supra studies have been launched to better understand the damage process of the armoured flat tile elements of the actively cooled toroidal pump limiter, leading to the characterization of the damageable mechanical behaviour of the used N11 CFC material and of the CFC/Cu bond. Up until now the calculations have shown damage developing in the CFC (within the zone submitted to high shear stress) and in the bond (from the free edge of the CFC/Cu interface). Damage is due to manufacturing shear stresses and does not evolve under heat due to stress relaxation. For the ITER divertor, NB31 material has been characterized and the characterization of NB41 is in progress. Finite element calculations show again the development of CFC damage in the high shear stress zones after manufacturing. Stresses also decrease under heat flux so the damage does not evolve. The characterization of the CFC/Cu bond is more complex due to the monoblock geometry, which leads to more scattered stresses. These calculations allow the fabrication difficulties to be better understood and will help to analyse future high heat flux tests on various mock-ups.

  8. Load Prediction in District Heating Systems with Regard to Scenarios and Uncertainties in Weather; Lastprognoser foer fjaerrvaerme med haensyn till scenarier och osaekerheter i vaedret

    Energy Technology Data Exchange (ETDEWEB)

    Hedberg, Martin; Koppers, Gijs [Meteopolaris AB, Nacka (Sweden)

    2011-11-15

    The report shows, by means of load calculations on ensemble weather forecasts and subsequent production planning, that by a better optimization of the operation of district heating plants the costs of production of heat and electricity can be reduced. During a fifth of the time the saving potential is 5% or more.

  9. Thin film flow and heat transfer over an unsteady stretching sheet with thermal radiation, internal heating in presence of external magnetic field

    CERN Document Server

    Metri, Prashant G; Abel, M Subhash

    2016-01-01

    In this paper we present a mathematical analysis of thin film flow and heat transfer to a laminar liquid film from a horizontal stretching sheet. The flow of thin liquid film and subsequent heat transfer from the stretching surface is investigated with the aid of similarity transformations. Similarity transformations are used to convert unsteady boundary layer equations to a system of non-linear ordinary differential equations. The resulting non-linear differential equations are solved numerically using Runge-kutta-Fehlberg and Newton-Raphson schemes. A relationship between film thickness $\\beta$ and the unsteadiness parameter $S$ is found, the effect of unsteadiness parameter $S$, and the Prandtl number $Pr$, Magnetic field parameter $Mn$, Radiation parameter $Nr$ and viscous dissipation parameter $Ec$ and heat source parameter $\\gamma$ on the temperature distributions are presented and discussed in detail. Present analysis shows that the combined effect of magnetic field, thermal radiation, heat source and ...

  10. An Electrothermal Plasma Source Developed for Simulation of Transient Heat Loads in Future Large Fusion Devices

    Science.gov (United States)

    Gebhart, Trey; Baylor, Larry; Winfrey, Leigh

    2016-10-01

    The realization of fusion energy requires materials that can withstand high heat and particle fluxes at the plasma material interface. In this work, an electrothermal (ET) plasma source has been designed as a possible transient heat flux source for a linear plasma material interaction device. An ET plasma source operates in the ablative arc regime, which is driven by a DC capacitive discharge. The current travels through the 4mm bore of a boron nitride liner and subsequently ablates and ionizes the liner material. This results in a high density plasma with a large unidirectional bulk flow out of the source exit. The pulse length for the ET source has been optimized using a pulse forming network to have a duration of 1ms at full-width half maximum. The peak currents and maximum source energies seen in this system are 2kA and 5kJ. The goal of this work is to show that the ET source produces electron densities and heat fluxes that are comparable to transient events in future large magnetic confinement fusion devices. Heat flux, plasma temperature, and plasma density were determined for each test shot using infrared imaging and optical spectroscopy techniques. This work will compare the ET source output (heat flux, temperature, and density) with and without an applied magnetic field. Research sponsored by the Laboratory Directed Research and Development Program of Oak Ridge National Laboratory, managed by UT-Battelle, LLC, for the U. S. Department of Energy.

  11. Heat pumps: impact of the partial load operation on the efficiency; Pompes a chaleur: impact du fonctionnement a charge partielle sur le rendement

    Energy Technology Data Exchange (ETDEWEB)

    Bernier, J. [Climastar, 35 - Vitre (France)

    2002-10-01

    On site measurements have permitted to demonstrate the energy loss generated by the rise of rate of heat pumps. The aim of this article is to propose a method for the calculation of the effective power a heat pump with respect to the duration of the operation cycle. The effective power varies with the thermal inertia of the heat emitter, with the regulation, with the size of the pump and with its load ratio. (J.S.)

  12. Experimental investigations on an axial grooved cryogenic heat pipe

    Directory of Open Access Journals (Sweden)

    Senthil Kumar Muniappan

    2012-01-01

    Full Text Available This paper deals with development and studies of a trapezoidal axial grooved nitrogen heat pipe. A special liquid nitrogen cryostat has been designed and developed for evaluating the performance of heat pipe where the condenser portion is connected to the cold sink externally. Experiments have been performed on the heat pipe as well as on an equivalent diameter copper rod at different heat loads. The steady state performance of the heat pipe is compared with that of copper rod.

  13. Artificial Neural Networks: a viable tool to design heat load smoothing strategies for the ITER Toroidal Field coils

    Science.gov (United States)

    Froio, A.; Bonifetto, R.; Carli, S.; Quartararo, A.; Savoldi, L.; Zanino, R.

    2015-12-01

    In superconducting tokamaks, cryoplants provide the helium needed to cool the superconducting magnet systems. The evaluation of the heat load from the magnets to the cryoplant is fundamental for the design of the latter and the assessment of suitable strategies to smooth the heat load pulses induced by the pulsed plasma scenarios is crucial for the operation. Here, a simplified thermal-hydraulic model of an ITER Toroidal Field (TF) magnet, based on Artificial Neural Networks (ANNs), is developed and inserted into a detailed model of the ITER TF winding and casing cooling circuits based on the state-of-the-art 4C code, which also includes active controls. The low computational effort requested by such a model allows performing a fast parametric study, to identify the best smoothing strategy during standard plasma operation. The ANNs are trained using 4C simulations, and the predictive capabilities of the simplified model are assessed against 4C simulations, both with and without active smoothing, in terms of accuracy and computational time.

  14. Modelling energy savings in the Danish building sector combined with internalisation of health related externalities in a heat and power system optimisation model

    DEFF Research Database (Denmark)

    Zvingilaite, Erika

    2013-01-01

    A substantial untapped energy saving potential rests in the building sector and is expected to play an important role in achieving reduction of environmental impacts of energy. In order to utilise this potential, effective policy measures need to be adopted to remove the existing barriers...... and create incentives. For that purpose, the cost effective energy saving options together with an optimal level of savings and expected environmental benefits have to be identified. The paper reports on a study that analyses these questions by including heat-saving measures in buildings into an energy....... Furthermore, the results suggest that changes in the energy generation sector are the prime driver behind the reduction of environmental externalities of energy. Heat savings in buildings play only a small role under model assumptions. © 2012Elsevier Ltd. All rights reserved....

  15. Study of the effect of external heating and internal temperature build-up during polymerization on the morphology of porous polymethacrylate adsorbent

    Energy Technology Data Exchange (ETDEWEB)

    Wei, Chan Yi, E-mail: vicchanyiwei@hotmail.com; Ongkudon, Clarence M., E-mail: clarence@ums.edu.my; Kansil, Tamar, E-mail: tamarkansil87@gmail.com [Biotechnology Research Institute, Universiti Malaysia Sabah, Jalan UMS, 88400 Kota Kinabalu, Sabah (Malaysia)

    2015-07-22

    Modern day synthesis protocols of methacrylate monolithic polymer adsorbent are based on existing polymerization blueprint without a thorough understanding of the dynamics of pore structure and formation. This has resulted in unproductiveness of polymer adsorbent consequently affecting purity and recovery of final product, productivity, retention time and cost effectiveness of the whole process. The problems magnified in monolith scaling-up where internal heat buildup resulting from external heating and high exothermic polymerization reaction was reflected in cracking of the adsorbent. We believe that through careful and precise control of the polymerization kinetics and parameters, it is possible to prepare macroporous methacrylate monolithic adsorbents with controlled pore structures despite being carried out in an unstirred mould. This research involved the study of the effect of scaling-up on pore morphology of monolith, in other words, porous polymethacrylate adsorbents that were prepared via bulk free radical polymerization process by imaging the porous morphology of polymethacrylate with scanning electron microscope.

  16. The Effect of Thermal Mass on Annual Heat Load and Thermal Comfort in Cold Climate Construction

    DEFF Research Database (Denmark)

    Stevens, Vanessa; Kotol, Martin; Grunau, Bruno

    2016-01-01

    Thermal mass in building construction refers to a building material's ability to absorb and release heat based on changing environmental conditions. In building design, materials with high thermal mass used in climates with a diurnal temperature swing around the interior set-point temperature hav...

  17. Preparation of calcium chloride-loaded solid lipid particles and heat-triggered calcium ion release

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Huangying; Kim, Jin-Chul [Kangwon National University, Chunchon (Korea, Republic of)

    2015-08-15

    CaCl{sub 2}-loaded solid lipid particles (SLPs) were prepared by a melt/emulsification/solidification method. CaCl{sub 2} microparticles (1-5 μm) could be obtained in a mortar with aid of the dispersant (Tween 80/Span80 (35/65, w/w)) when the ratio of CaCl{sub 2} to dispersant was 2 : 0.1 (w/w). SLP was prepared by dispersing 0.42 g of micronized CaCl{sub 2} particles in 2 g of molten PBSA, emulsifying the mixture at 85 .deg. C in 40 ml of Tween 20 solution (0.5% w/v), and quenching the emulsion in an ice bath. The diameter of CaCl{sub 2}-loaded SLP was 10-150 μm. The unenveloped CaCl{sub 2} could be removed by dialysis and the specific loading of CaCl{sub 2} in SLP was 0.036mg/mg. An EDS spectrum of CaCl{sub 2}-loaded SLP, which was dialyzed, showed that the unenveloped CaCl{sub 2} was completely removed. Any excipients (dispersant, Tween 20, CaCl{sub 2}) had little effect on the melting point of SLPs. No appreciable amount of Ca2+ was released in 20-50 .deg. C for 22 h. But the release degree at 60 .deg. C was significant (about 2.3%) during the same period. The matrix of the lipid particle was in a liquid state at 60 .deg. C, so CaCl{sub 2} particles could move freely and contact the surrounding water, leading to the release. At 70 .deg. C, the release degree at a given time was a few times higher than that obtained at 60 .deg. C.

  18. Effect of External Forced Flow and Boiling Film on Heat Transfer of AISI 4140 Steel Horizontal Rod During Direct Quenching%Effect of External Forced Flow and Boiling Film on Heat Transfer of AISI 4140 Steel Horizontal Rod During Direct Quenching

    Institute of Scientific and Technical Information of China (English)

    A H Meysami; R Ghasemzadeh; S H Seyedein; M R Aboutalebi

    2011-01-01

    The effects of rod falling and moving, external flow field, boiling film and radiation were investigated on fluid flow and heat transfer of AISI 4140 steel horizontal rod during direct quenching by mathematical modeling. The flow field and heat transfer in quenching tank were simulated by computational fluid dynamics (CFD) method considering falling and moving of rods during process. Therefore, modeling of flow field was done by a fixed-mesh method for general moving objects equations, and then, energy equation was solved with a numerical approach so that effeet of boiling film heat flux was considered as a source term in energy equation for solid-liquid boundary. Simulated results were verified by comparing with published and experimental data and there was a good agreement between them. Also, the effects of external forced flow and film boiling were investigated on heat flux output, temperature distribution and heat transfer coefficient of rod. Also simulated results determined optimum quenching time for this process.

  19. Air-To-Water Heat Pumps with Radiant Delivery in Low Load Homes: Tucson, Arizona and Chico, California (Fact Sheet)

    Energy Technology Data Exchange (ETDEWEB)

    2013-11-01

    Space conditioning represents nearly 50% of average residential household energy consumption, highlighting the need to identify alternative cost-effective, energy-efficient cooling and heating strategies. As homes are better built, there is an increasing need for strategies that are particularly well suited for high performance, low load homes. ARBI researchers worked with two test homes in hot-dry climates to evaluate the in-situ performance of air-to-water heat pump (AWHP) systems, an energy efficient space conditioning solution designed to cost-effectively provide comfort in homes with efficient, safe, and durable operation. Two monitoring projects of test houses in hot-dry climates were initiated in 2010 to test this system. Both systems were fully instrumented and have been monitored over one year to capture complete performance data over the cooling and heating seasons. Results are used to quantify energy savings, cost-effectiveness, and system performance using different operating modes and strategies. A calibrated TRNSYS model was developed and used to evaluate performance in various climate regions. This strategy is most effective in tight, insulated homes with high levels of thermal mass (i.e. exposed slab floors).

  20. Melt layer erosion of pure and lanthanum doped tungsten under VDE-like high heat flux loads

    Science.gov (United States)

    Yuan, Y.; Greuner, H.; Böswirth, B.; Luo, G.-N.; Fu, B. Q.; Xu, H. Y.; Liu, W.

    2013-07-01

    Heat loads expected for VDEs in ITER were applied in the neutral beam facility GLADIS at IPP Garching. Several ˜3 mm thick rolled pure W and W-1 wt% La2O3 plates were exposed to pulsed hydrogen beams with a central heat flux of 23 MW/m2 for 1.5-1.8 s. The melting thresholds are determined, and melt layer motion as well as material structure evolutions are shown. The melting thresholds of the two W grades are very close in this experimental setup. Lots of big bubbles with diameters from several μm to several 10 μm in the re-solidified layer of W were observed and they spread deeper with increasing heat flux. However, for W-1 wt% La2O3, no big bubbles were found in the corrugated melt layer. The underlying mechanisms referred to the melt layer motion and bubble issues are tentatively discussed based on comparison of the erosion characteristics between the two W grades.

  1. Melt layer erosion of pure and lanthanum doped tungsten under VDE-like high heat flux loads

    Energy Technology Data Exchange (ETDEWEB)

    Yuan, Y., E-mail: yuanyue08@mails.tsinghua.edu.cn [Department of Material Science and Engineering, Tsinghua University, Haidian District, Beijing 100084 (China); Greuner, H.; Böswirth, B. [Max-Planck-Institut für Plasmaphysik, EURATOM Association, 85748 Garching (Germany); Luo, G.-N. [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, Anhui 230031 (China); Fu, B.Q.; Xu, H.Y. [Department of Material Science and Engineering, Tsinghua University, Haidian District, Beijing 100084 (China); Liu, W., E-mail: liuw@mail.tsinghua.edu.cn [Department of Material Science and Engineering, Tsinghua University, Haidian District, Beijing 100084 (China)

    2013-07-15

    Heat loads expected for VDEs in ITER were applied in the neutral beam facility GLADIS at IPP Garching. Several ∼3 mm thick rolled pure W and W–1 wt% La{sub 2}O{sub 3} plates were exposed to pulsed hydrogen beams with a central heat flux of 23 MW/m{sup 2} for 1.5–1.8 s. The melting thresholds are determined, and melt layer motion as well as material structure evolutions are shown. The melting thresholds of the two W grades are very close in this experimental setup. Lots of big bubbles with diameters from several μm to several 10 μm in the re-solidified layer of W were observed and they spread deeper with increasing heat flux. However, for W–1 wt% La{sub 2}O{sub 3}, no big bubbles were found in the corrugated melt layer. The underlying mechanisms referred to the melt layer motion and bubble issues are tentatively discussed based on comparison of the erosion characteristics between the two W grades.

  2. ITER-relevant transient heat loads on tungsten exposed to plasma and beryllium

    Science.gov (United States)

    Yu, J. H.; Doerner, R. P.; Dittmar, T.; Höschen, T.; Schwarz-Selinger, T.; Baldwin, M. J.

    2014-04-01

    Tungsten (W) is presently the most attractive plasma facing material for future fusion reactors. Off-normal transient events such as edge localized modes and disruptions are simulated with a pulsed laser system in the PISCES-B facility, providing pulses with 1-10 ms duration with absorbed heat flux factors up to ˜90 MJ m-2 s-1/2. This paper characterizes surface morphology changes and damage thresholds under transient heating on W exposed to He plasma or D plasma with and without Be coatings. W is damaged in the form of grain growth, surface roughening, melting and cracking. With a Be coating on the order of μm thick, the laser pulse produces a variety of Be surface changes including Be-W alloying, vaporization of the Be layer, melting and delamination.

  3. Numerical Analysis of a Pulse Detonation Cross Flow Heat Load Experiment

    Science.gov (United States)

    Paxson, Daniel E.; Naples, Andrew .; Hoke, John L.; Schauer, Fred

    2011-01-01

    A comparison between experimentally measured and numerically simulated, time-averaged, point heat transfer rates in a pulse detonation (PDE) engine is presented. The comparison includes measurements and calculations for heat transfer to a cylinder in crossflow and to the tube wall itself using a novel spool design. Measurements are obtained at several locations and under several operating conditions. The measured and computed results are shown to be in substantial agreement, thereby validating the modeling approach. The model, which is based in computational fluid dynamics (CFD) is then used to interpret the results. A preheating of the incoming fuel charge is predicted, which results in increased volumetric flow and subsequent overfilling. The effect is validated with additional measurements.

  4. Buoyancy effects in vertical rectangular duct with coplanar magnetic field and single sided heat load

    Energy Technology Data Exchange (ETDEWEB)

    Kirillov, I.R. [NIIEFA – JSC “D.V. Efremov Institute of Electrophysical Apparatus”, St. Petersburg, 196641 (Russian Federation); Obukhov, D.M., E-mail: obukhov@sintez.niiefa.spb.su [NIIEFA – JSC “D.V. Efremov Institute of Electrophysical Apparatus”, St. Petersburg, 196641 (Russian Federation); Genin, L.G. [MPEI – National Research University “Moscow Power Engineering Institute”, 14 Krasnokazarmennaya str., Moscow (Russian Federation); Sviridov, V.G.; Razuvanov, N.G.; Batenin, V.M.; Belyaev, I.A. [JIHT – Joint Institute of High Temperatures of the Russian Academy of Science, 13/19, Igorskaya str., Moscow (Russian Federation); Poddubnyi, I.I. [MPEI – National Research University “Moscow Power Engineering Institute”, 14 Krasnokazarmennaya str., Moscow (Russian Federation); Pyatnitskaya, N.Yu. [JIHT – Joint Institute of High Temperatures of the Russian Academy of Science, 13/19, Igorskaya str., Moscow (Russian Federation)

    2016-03-15

    Highlights: • Heat transfer in vertical duct mercury flow in coplanar magnetic field is studied. • Mean velocity, temperature and temperature pulsations are measured. • Buoyancy influence on heat transfer is found. - Abstract: This article investigates an effect which was found out in downward flow of liquid metal (LM) in vertical rectangular duct in coplanar magnetic field (MF). The experiments have been performed on facility which located in JIHT. This facility is magneto hydrodynamic (MHD) mercury close-loop. The temperature field measurements have been performed at one side heating conditions in coplanar magnetic field. The averaged temperature fields, wall temperature distributions and statistical characteristics of temperature fluctuation have been obtained. The strong influence of counter thermo-gravitational convection (TGC) on average and fluctuation parameters has been observed. The influence of TGC in magnetic field leads to developing of temperature low-frequency fluctuations with high magnitude. The temperature fluctuation amplitude in a wide range of operating conditions is higher than turbulence level.

  5. Study of Heat Transfer in a Kapok Material from the Convective Heat Transfer Coefficient and the Excitation Pulse of Solicitations External Climatic

    Directory of Open Access Journals (Sweden)

    M. Dieng

    2013-02-01

    Full Text Available The aim of this study is to characterize thermal insulating local material, kapok, from a study in 3 dimensions in Cartesian coordinate and in dynamic frequency regime. From a study a 3 dimensional the heat transfer through a material made of wool kapok (thermal conductivity: &lambda = 0,035 W/m/K; density: &rho = 12, 35 kg/m3; thermal diffusivity: &alpha = 17, 1.10-7 m2 /s is presented. The evolution curves of temperature versus convective heat transfer coefficient have helped highlight the importance of pulse excitation and the depth in the material. The thermal impedance is studied from representations of Nyquist and Bode diagrams allowing characterizing the thermal behavior from thermistors. The evolution of the thermal impedance with the thermal capacity of the material is presented.

  6. Experimental study of ELM-like heat loading on beryllium under ITER operational conditions

    Science.gov (United States)

    Spilker, B.; Linke, J.; Pintsuk, G.; Wirtz, M.

    2016-02-01

    The experimental fusion reactor ITER, currently under construction in Cadarache, France, is transferring the nuclear fusion research to the power plant scale. ITER’s first wall (FW), armoured by beryllium, is subjected to high steady state and transient power loads. Transient events like edge localized modes not only deposit power densities of up to 1.0 GW m-2 for 0.2-0.5 ms in the divertor of the machine, but also affect the FW to a considerable extent. Therefore, a detailed study was performed, in which transient power loads with absorbed power densities of up to 1.0 GW m-2 were applied by the electron beam facility JUDITH 1 on beryllium specimens at base temperatures of up to 300 °C. The induced damage was evaluated by means of scanning electron microscopy and laser profilometry. As a result, the observed damage was highly dependent on the base temperatures and absorbed power densities. In addition, five different classes of damage, ranging from ‘no damage’ to ‘crack network plus melting’, were defined and used to locate the damage, cracking, and melting thresholds within the tested parameter space.

  7. The dopamine receptor D4 gene and familial loading interact with perceived parenting in predicting externalizing behavior problems in early adolescence: the TRacking Adolescents' Individual Lives Survey (TRAILS)

    NARCIS (Netherlands)

    Marsman, R.; Oldehinkel, A.J.; Ormel, J.; Buitelaar, J.K.

    2013-01-01

    Although externalizing behavior problems show in general a high stability over time, the course of externalizing behavior problems may vary from individual to individual. Our main goal was to investigate the predictive role of parenting on externalizing behavior problems. In addition, we investigate

  8. The dopamine receptor D4 gene and familial loading interact with perceived parenting in predicting externalizing behavior problems in early adolescence : The TRacking Adolescents' Individual Lives Survey (TRAILS)

    NARCIS (Netherlands)

    Marsman, Rianne; Oldehinkel, Albertine J.; Ormel, Johan; Buitelaar, Jan K.

    2013-01-01

    Although externalizing behavior problems show in general a high stability over time, the course of externalizing behavior problems may vary from individual to individual. Our main goal was to investigate the predictive role of parenting on externalizing behavior problems. In addition, we investigate

  9. High-heat-load monochromator options for the RIXS beamline at the APS with the MBA lattice

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Zunping, E-mail: zpliu@anl.gov; Gog, Thomas, E-mail: gog@aps.anl.gov; Stoupin, Stanislav A.; Upton, Mary H.; Ding, Yang; Kim, Jung-Ho; Casa, Diego M.; Said, Ayman H.; Carter, Jason A.; Navrotski, Gary [Advanced Photon Source, Argonne National Laboratory, 9700 S. Cass Ave, Lemont, IL 60439 (United States)

    2016-07-27

    With the MBA lattice for APS-Upgrade, tuning curves of 2.6 cm period undulators meet the source requirements for the RIXS beamline. The high-heat-load monochromator (HHLM) is the first optical white beam component. There are four options for the HHLM such as diamond monochromators with refrigerant of either water or liquid nitrogen (LN{sub 2}), and silicon monochromators of either direct or indirect cooling system. Their performances are evaluated at energy 11.215 keV (Ir L-III edge). The cryo-cooled diamond monochromator has similar performance as the water-cooled diamond monochromator because GaIn of the Cu-GaIn-diamond interface becomes solid. The cryo-cooled silicon monochromators perform better, not only in terms of surface slope error due to thermal deformation, but also in terms of thermal capacity.

  10. Estimation of the dust production rate from the tungsten armour after repetitive ELM-like heat loads

    Science.gov (United States)

    Pestchanyi, S.; Garkusha, I.; Makhlaj, V.; Landman, I.

    2011-12-01

    Experimental simulations for the erosion rate of tungsten targets under ITER edge-localized mode (ELM)-like surface heat loads of 0.75 MJ m-2 causing surface melting and of 0.45 MJ m-2 without melting have been performed in the QSPA-Kh50 plasma accelerator. Analytical considerations allow us to conclude that for both energy deposition values the erosion mechanism is solid dust ejection during surface cracking under the action of thermo-stress. Tungsten influx into the ITER containment of NW~5×1018 W per medium size ELM of 0.75 MJ m-2 and 0.25 ms time duration has been estimated. The radiation cooling power of Prad=150-300 MW due to such influx of tungsten is intolerable: it should cool the ITER core to 1 keV within a few seconds.

  11. Heat transfer characteristics and entropy generation for wing-shaped-tubes with longitudinal external fins in cross-flow

    Energy Technology Data Exchange (ETDEWEB)

    Ahmed, Sayed Ahmed E. Sayed; Mesalhy, Osama M.; Abdelatief, Mohamed A. [Zagazig University, Zagazig (Egypt)

    2016-06-15

    A numerical study is conducted to clarify heat transfer characteristics, effectiveness and entropy generation for a bundle of wingshaped-tubes attached to Longitudinal fins (LF) at downstream side. The air-side Re{sub a} ranged from 1.8 x 10{sup 3} to 9.7 x 10{sup 3} . The fin height (h{sub f}) and fin thickness (δ) have been changed as: (2 mm <= hf <= 12 mm) and (1.5 mm <= δ <= 3.5 mm). The analysis of entropy generation is based on the principle of minimizing the rate of total entropy generation that includes the generation of entropy due to heat transfer and friction losses. The temperature field around the wing-shaped-tubes with (LF) is predicted using commercial CFD FLUENT 6.3.26 software package. Correlations of Nu{sub a}, St{sub a}, and Bejan number (Be), as well as the irreversibility distribution ratio (Φ) in terms of Re{sub a} and design parameters for the studied bundle are presented. Results indicated that, installing fins with heights from 2 to 12 mm results in an increase in Nu{sub a} from 11 to 36% comparing with that of wing-shaped tubes without fins (NOF). The highest and lowest values of effectiveness(ε) at every value of the considered Re{sub a} range are occurred at hf = 6 mm and (NOF), espectively. The wing-shaped-tubes heat exchanger with hf = 6 mm has the highest values of (ε), efficiency index (η) and area goodness factor (G{sub a}) and also the lowest values of Φ and hence the best performance comparing with other arrangements. The minimum values of Φ are occurred at hf = 6 mm. (Be) decreases with increasing Re{sub a} for all studied hf. The heat transfer irreversibility predominates for (1800 <= Re{sub a} <= 4200) while the opposite is true for (6950 < Re{sub a} <= 9700). δ has negligible effect on Nu{sub a} and heat transfer irreversibility. Comparisons between the experimental and numerical results of the present study and those, previously, obtained for similar available studies showed good agreements.

  12. Mitigation of upward and downward vertical displacement event heat loads with upper or lower massive gas injection in DIII-D

    Energy Technology Data Exchange (ETDEWEB)

    Hollmann, E. M.; Moyer, R. A. [University of California-San Diego, La Jolla, California 92093 (United States); Commaux, N.; Shiraki, D. [Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States); Eidietis, N. W.; Parks, P. B. [General Atomics, San Diego, California 92186 (United States); Lasnier, C. J. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)

    2015-10-15

    Intentionally triggered upward and downward vertical displacement events (VDEs) leading to disruptions were pre-emptively mitigated with neon massive gas injection (MGI) coming from either above or below the plasma. Global indicators of disruption mitigation effectiveness (conducted heat loads, radiated power, and vessel motion) do not show a clear improvement when mitigating with the gas jet located closer to the VDE impact area. A clear trend of improved mitigation is observed for earlier MGI timing relative to the VDE impact time. The plasma edge magnetic perturbation is seen to lock to a preferential phase during the VDE thermal quench, but this phase is not clearly matched by preliminary attempts to fit to the conducted heat load phase. Clear indications of plasma infra-red (IR) emission are observed both before and during the disruptions. This IR emission can affect calculation of disruption heat loads; here, the time decay of post-disruption IR signals is used to correct for this effect.

  13. Mitigation of upward and downward vertical displacement event heat loads with upper or lower massive gas injection in DIII-D

    Science.gov (United States)

    Hollmann, E. M.; Commaux, N.; Eidietis, N. W.; Lasnier, C. J.; Moyer, R. A.; Parks, P. B.; Shiraki, D.

    2015-10-01

    Intentionally triggered upward and downward vertical displacement events (VDEs) leading to disruptions were pre-emptively mitigated with neon massive gas injection (MGI) coming from either above or below the plasma. Global indicators of disruption mitigation effectiveness (conducted heat loads, radiated power, and vessel motion) do not show a clear improvement when mitigating with the gas jet located closer to the VDE impact area. A clear trend of improved mitigation is observed for earlier MGI timing relative to the VDE impact time. The plasma edge magnetic perturbation is seen to lock to a preferential phase during the VDE thermal quench, but this phase is not clearly matched by preliminary attempts to fit to the conducted heat load phase. Clear indications of plasma infra-red (IR) emission are observed both before and during the disruptions. This IR emission can affect calculation of disruption heat loads; here, the time decay of post-disruption IR signals is used to correct for this effect.

  14. A novel 1D/2D model for simulating conjugate heat transfer applied to flow boiling in tubes with external fins

    Science.gov (United States)

    Ocłoń, Paweł; Łopata, Stanisław; Nowak, Marzena

    2015-04-01

    This study presents a novel, simplified model for the time-efficient simulation of transient conjugate heat transfer in round tubes. The flow domain and the tube wall are modeled in 1D and 2D, respectively and empirical correlations are used to model the flow domain in 1D. The model is particularly useful when dealing with complex physics, such as flow boiling, which is the main focus of this study. The tube wall is assumed to have external fins. The flow is vertical upwards. Note that straightforward computational fluid dynamics (CFD) analysis of conjugate heat transfer in a system of tubes, leads to 3D modeling of fluid and solid domains. Because correlation is used and dimensionality reduced, the model is numerically more stable and computationally more time-efficient compared to the CFD approach. The benefit of the proposed approach is that it can be applied to large systems of tubes as encountered in many practical applications. The modeled equations are discretized in space using the finite volume method, with central differencing for the heat conduction equation in the solid domain, and upwind differencing of the convective term of the enthalpy transport equation in the flow domain. An explicit time discretization with forward differencing was applied to the enthalpy transport equation in the fluid domain. The conduction equation in the solid domain was time discretized using the Crank-Nicholson scheme. The model is applied in different boundary conditions and the predicted boiling patterns and temperature fields are discussed.

  15. Comparative study of beam losses and heat loads reduction methods in MITICA beam source

    Energy Technology Data Exchange (ETDEWEB)

    Sartori, E., E-mail: emanuele.sartori@igi.cnr.it; Agostinetti, P.; Dal Bello, S.; Marcuzzi, D.; Serianni, G.; Veltri, P. [Consorzio RFX, Euratom-ENEA association, C.so Stati Uniti 4, 35127 Padova (Italy); Sonato, P. [Consorzio RFX, Euratom-ENEA association, C.so Stati Uniti 4, 35127 Padova (Italy); Dipartimento di Ingegneria Elettrica, Padova University, Via Gradenigo 6/a, 35131 Padova (Italy)

    2014-02-15

    In negative ion electrostatic accelerators a considerable fraction of extracted ions is lost by collision processes causing efficiency loss and heat deposition over the components. Stripping is proportional to the local density of gas, which is steadily injected in the plasma source; its pumping from the extraction and acceleration stages is a key functionality for the prototype of the ITER Neutral Beam Injector, and it can be simulated with the 3D code AVOCADO. Different geometric solutions were tested aiming at the reduction of the gas density. The parameter space considered is limited by constraints given by optics, aiming, voltage holding, beam uniformity, and mechanical feasibility. The guidelines of the optimization process are presented together with the proposed solutions and the results of numerical simulations.

  16. Comparative study of beam losses and heat loads reduction methods in MITICA beam source

    Science.gov (United States)

    Sartori, E.; Agostinetti, P.; Dal Bello, S.; Marcuzzi, D.; Serianni, G.; Sonato, P.; Veltri, P.

    2014-02-01

    In negative ion electrostatic accelerators a considerable fraction of extracted ions is lost by collision processes causing efficiency loss and heat deposition over the components. Stripping is proportional to the local density of gas, which is steadily injected in the plasma source; its pumping from the extraction and acceleration stages is a key functionality for the prototype of the ITER Neutral Beam Injector, and it can be simulated with the 3D code AVOCADO. Different geometric solutions were tested aiming at the reduction of the gas density. The parameter space considered is limited by constraints given by optics, aiming, voltage holding, beam uniformity, and mechanical feasibility. The guidelines of the optimization process are presented together with the proposed solutions and the results of numerical simulations.

  17. Effects of short-term aerobic exercise with and without external loading on bone metabolism and balance in postmenopausal women with osteoporosis.

    Science.gov (United States)

    Roghani, Tayebeh; Torkaman, Giti; Movasseghe, Shafieh; Hedayati, Mehdi; Goosheh, Babak; Bayat, Noushin

    2013-02-01

    The aim of this study is to evaluate the effect of submaximal aerobic exercise with and without external loading on bone metabolism and balance in postmenopausal women with osteoporosis (OP). Thirty-six volunteer, sedentary postmenopausal women with OP were randomly divided into three groups: aerobic, weighted vest, and control. Exercise for the aerobic group consisted of 18 sessions of submaximal treadmill walking, 30 min daily, 3 times a week. The exercise program for the weighted-vest group was identical to that of the aerobic group except that the subjects wore a weighted vest (4-8 % of body weight). Body composition, bone biomarkers, bone-specific alkaline phosphatase (BALP) and N-terminal telopeptide of type 1 collagen (NTX), and balance (near tandem stand, NTS, and star-excursion, SE) were measured before and after the 6-week exercise program. Fat decreased (p = 0.01) and fat-free mass increased (p = 0.005) significantly in the weighted-vest group. BALP increased and NTX decreased significantly in both exercise groups (p ≤ 0.05). After 6 weeks of exercise, NTS score increased in the exercise groups and decreased in the control group (aerobic: +49.68 %, weighted vest: +104.66 %, and control: -28.96 %). SE values for all directions increased significantly in the weighted-vest group. Results showed that the two exercise programs stimulate bone synthesis and decrease bone resorption in postmenopausal women with OP, but that exercise while wearing a weighted vest is better for improving balance.

  18. Researching Complex Heat, Air and Moisture Interactions for a Wide-Range of Building Envelope Systems and Environmental Loads

    Energy Technology Data Exchange (ETDEWEB)

    Karagiozis, A.N.

    2007-05-15

    This document serves as the final report documenting work completed by Oak Ridge National Laboratory (ORNL) and the Fraunhofer Institute in Building Physics (Holzkirchen, Germany) under an international CRADA No. 0575 with Fraunhofer Institute of Bauphysics of the Federal Republic of Germany for Researching Complex Heat, Air and Moisture Interactions for a Wide Range of Building Envelope Systems and Environmental Loads. This CRADA required a multi-faceted approach to building envelope research that included a moisture engineering approach by blending extensive material property analysis, laboratory system and sub-system thermal and moisture testing, and advanced moisture analysis prediction performance. The Participant's Institute for Building physics (IBP) and the Contractor's Buildings Technology Center (BTC) identified potential research projects and activities capable of accelerating and advancing the development of innovative, low energy and durable building envelope systems in diverse climates. This allowed a major leverage of the limited resources available to ORNL to execute the required Department of Energy (DOE) directives in the area of moisture engineering. A joint working group (ORNL and Fraunhofer IBP) was assembled and a research plan was executed from May 2000 to May 2005. A number of key deliverables were produced such as adoption of North American loading into the WUFI-software. in addition the ORNL Weather File Analyzer was created and this has been used to address environmental loading for a variety of US climates. At least 4 papers have been co-written with the CRADA partners, and a chapter in the ASTM Manual 40 on Moisture Analysis and Condensation Control. All deliverables and goals were met and exceeded making this collaboration a success to all parties involves.

  19. Evolution of transiently melt damaged tungsten under ITER-relevant divertor plasma heat loading

    Energy Technology Data Exchange (ETDEWEB)

    Bardin, S., E-mail: s.bardin@differ.nl [FOM Institute DIFFER – Dutch Institute For Fundamental Energy Research, Ass EURATOM-FOM, Trilateral Euregio Cluster, Nieuwegein (Netherlands); Morgan, T.W. [FOM Institute DIFFER – Dutch Institute For Fundamental Energy Research, Ass EURATOM-FOM, Trilateral Euregio Cluster, Nieuwegein (Netherlands); Glad, X. [Université de Lorraine, Institut Jean Lamour, Vandoeuvre-les-Nancy (France); Pitts, R.A. [ITER Organization, CS 90 046, 13067 St Paul Lez Durance Cedex (France); De Temmerman, G. [FOM Institute DIFFER – Dutch Institute For Fundamental Energy Research, Ass EURATOM-FOM, Trilateral Euregio Cluster, Nieuwegein (Netherlands); ITER Organization, CS 90 046, 13067 St Paul Lez Durance Cedex (France)

    2015-08-15

    A high-repetition-rate ELM simulation system was used at both the Pilot-PSI and Magnum-PSI linear plasma devices to investigate the nature of W damage under multiple shallow melt events and the subsequent surface evolution under ITER relevant plasma fluence and high ELM number. First, repetitive shallow melting of two W monoblocks separated by a 0.5 mm gap was obtained by combined pulsed/steady-state hydrogen plasma loading at normal incidence in the Pilot-PSI device. Surface modifications including melting, cracking and strong net-reshaping of the surface are obtained. During the second step, the pre-damaged W sample was exposed to a high flux plasma regime in the Magnum-PSI device with a grazing angle of 35°. SEM analysis indicates no measurable change to the surface state after the exposure in Magnum-PSI. An increase in transient-induced temperature rise of 40% is however observed, indicating a degradation of thermal properties over time.

  20. Variability in Heat Strain in Fully Encapsulated Impermeable Suits in Different Climates and at Different Work Loads.

    Science.gov (United States)

    DenHartog, Emiel A; Rubenstein, Candace D; Deaton, A Shawn; Bogerd, Cornelis Peter

    2017-03-01

    A major concern for responders to hazardous materials (HazMat) incidents is the heat strain that is caused by fully encapsulated impermeable (NFPA 1991) suits. In a research project, funded by the US Department of Defense, the thermal strain experienced when wearing these suits was studied. Forty human subjects between the ages of 25 and 50 participated in a protocol approved by the local ethical committee. Six different fully encapsulated impermeable HazMat suits were evaluated in three climates: moderate (24°C, 50% RH, 20°C WBGT), warm-wet (32°C, 60% RH, 30°C WBGT), and hot-dry (45°C, 20% RH, 37°C WBGT, 200 W m-2 radiant load) and at three walking speeds: 2.5, 4, and 5.5 km h-1. The medium speed, 4 km h-1, was tested in all three climates and the other two walking speeds were only tested in the moderate climate. Prior to the test a submaximal exercise test in normal clothing was performed to determine a relationship between heart rate and oxygen consumption (pretest). In total, 163 exposures were measured. Tolerance time ranged from as low as 20 min in the hot-dry condition to 60 min (the maximum) in the moderate climate, especially common at the lowest walking speed. Between the six difference suits limited differences were found, a two-layered aluminized suit exhibited significant shorter tolerance times in the moderate climate, but no other major significant differences were found for the other climates or workloads. An important characteristic of the overall dataset is the large variability between the subjects. Although the average responses seem suitable to be predicted, the variability in the warmer strain conditions ranged from 20 min up to 60 min. The work load in these encapsulated impermeable suits was also significantly higher than working in normal clothing and higher than predicted by the Pandolf equation. Heart rate showed a very strong correlation to body core temperature and was in many cases the limiting factor. Setting the heart rate

  1. Impact of Periodic Unsteadiness on Performance and Heat Load in Axial Flow Turbomachines

    Science.gov (United States)

    Sharma, Om P.; Stetson, Gary M.; Daniels, William A,; Greitzer, Edward M.; Blair, Michael F.; Dring, Robert P.

    1997-01-01

    Results of an analytical and experimental investigation, directed at the understanding of the impact of periodic unsteadiness on the time-averaged flows in axial flow turbomachines, are presented. Analysis of available experimental data, from a large-scale rotating rig (LSRR) (low speed rig), shows that in the time-averaged axisymmetric equations the magnitude of the terms representing the effect of periodic unsteadiness (deterministic stresses) are as large or larger than those due to random unsteadiness (turbulence). Numerical experiments, conducted to highlight physical mechanisms associated with the migration of combustor generated hot-streaks in turbine rotors, indicated that the effect can be simulated by accounting for deterministic stress like terms in the time-averaged mass and energy conservation equations. The experimental portion of this program shows that the aerodynamic loss for the second stator in a 1-1/2 stage turbine are influenced by the axial spacing between the second stator leading edge and the rotor trailing edge. However, the axial spacing has little impact on the heat transfer coefficient. These performance changes are believed to be associated with the change in deterministic stress at the inlet to the second stator. Data were also acquired to quantify the impact of indexing the first stator relative to the second stator. For the range of parameters examined, this effect was found to be of the same order as the effect of axial spacing.

  2. ITER-W monoblocks under high pulse number transient heat loads at high temperature

    Energy Technology Data Exchange (ETDEWEB)

    Loewenhoff, Th., E-mail: T.Loewenhoff@fz-juelich.de [Forschungszentrum Jülich, 52428 Jülich (Germany); Linke, J., E-mail: J.Linke@fz-juelich.de [Forschungszentrum Jülich, 52428 Jülich (Germany); Pintsuk, G., E-mail: G.Pintsuk@fz-juelich.de [Forschungszentrum Jülich, 52428 Jülich (Germany); Pitts, R.A., E-mail: Richard.Pitts@iter.org [ITER Organization, Route de Vinon sur Verdon, 13115 Saint Paul-Lez-Durance (France); Riccardi, B., E-mail: Bruno.Riccardi@f4e.europa.eu [Fusion for Energy Joint Undertaking, Josep Pla No. 2 – T B3 7/01, Barcelona 08019 (Spain)

    2015-08-15

    In the context of using a full-tungsten (W) divertor for ITER, thermal shock resistance has become even more important as an issue that may potentially influence the long term performance. To address this issue a unique series of experiments has been performed on ITER-W monoblock mock ups in three EU high heat flux facilities: GLADIS (neutral beam), JUDITH 2 (electron beam) and Magnum-PSI (plasma beam). This paper discusses the JUDITH 2 experiments. Two different base temperatures, 1200 °C and 1500 °C, were chosen superimposed by ∼18,000/100,000 transient events (Δt = 0.48 ms) of 0.2 and 0.6 GW/m{sup 2}. Results showed a stronger surface deterioration at higher base temperature, quantified by an increase in roughening. This is intensified if the same test is done after preloading (exposure to high temperature without transients), especially at higher base temperature when the material recrystallizes.

  3. Thermoregulatory and Physiological Responses of Najdi Sheep Exposed to Environmental Heat Load Prevailing in Saudi Arabia

    Directory of Open Access Journals (Sweden)

    A. A. Al-Haidary, R. S. Aljumaah, M. A. Alshaikh, K. A. Abdoun*, E. M. Samara, A. B. Okab and M. M. Alfuraiji

    2012-10-01

    Full Text Available The objective of this study was to evaluate the thermoregulatory and physiological responses of Najdi rams raised under hot summer conditions prevailing in Kingdom Saudi Arabia. The core temperature (Tcore showed circadian rhythm characterized by biphasic achrophases, which were associated with the feeding times during both seasons. Average daily Tcore was significantly (P<0.05 higher under hot summer conditions. However, the amplitudes of the rhythmic oscillation during winter and summer seasons were 0.85 and 0.56C, respectively. Rectal (Tre and skin temperatures (Tsk were significantly (P<0.05 higher under hot summer conditions and exhibited similar patterns during both seasons concurrent with the pattern of temperature humidity index (THI, reaching the maximum values late in the afternoon and the minimum values early in the morning. Respiratory rate (RR and heart rate (HR showed the same pattern of the thermal parameters and were significantly (P<0.05 higher under hot summer conditions. Serum concentrations of total protein, globulin, glucose, sodium and chloride were significantly (P<0.05 increased while those of albumin and calcium were decreased under hot summer conditions. The results obtained from this study indicate that hot summer conditions of Saudi Arabia is thermally stressful to Najdi rams. Therefore, Najdi sheep production under such conditions would require environmental and/or nutritional modification to alleviate the impact of heat stress.

  4. Model of the heat load under dynamic abrasive processing of food material

    Directory of Open Access Journals (Sweden)

    G. V. Аlеksееv

    2016-01-01

    Full Text Available The modern stage of the improvement food production is conditioned by tense fight for their cost-performance that is defined in significant measure by maximum efficiency of the use agricultural cheese. At the same time problems with disadvantage ecological condition, accompanying life our society, require from taken person of the food different influences on recovery of the organism. For decision of this problem to researchers most different countries unite their own efforts on decision of the touched questions. The improvement and development technology must rest in study existing. In base of the studies can lie the mathematical product models of the feeding and corresponding to processes created in different exploratory organization. The development qualitative, claimed, competitive products – a purpose of each modern producer, choosing for itself most idle time, effective and economic justified way of the decision given problems. Modern prospecting in theories and practical person of the checking quality and analysis allow to use in principal new methods at determination of the possible negative changes to product of the feeding happened in them, in particular, under heat processing. The given methods, except traditional touch component, take into account else and complex of the analytical models of the models, for positioning undesirable warm-up mode for processing the product in target group of the consumers (for instance for integer medical-preventive feeding.

  5. Impact of heat stress on conception rate of dairy cows in the moderate climate considering different temperature-humidity index thresholds, periods relative to breeding, and heat load indices.

    Science.gov (United States)

    Schüller, L K; Burfeind, O; Heuwieser, W

    2014-05-01

    The objectives of this retrospective study were to investigate the relationship between temperature-humidity index (THI) and conception rate (CR) of lactating dairy cows, to estimate a threshold for this relationship, and to identify periods of exposure to heat stress relative to breeding in an area of moderate climate. In addition, we compared three different heat load indices related to CR: mean THI, maximum THI, and number of hours above the mean THI threshold. The THI threshold for the influence of heat stress on CR was 73. It was statistically chosen based on the observed relationship between the mean THI at the day of breeding and the resulting CR. Negative effects of heat stress, however, were already apparent at lower levels of THI, and 1 hour of mean THI of 73 or more decreased the CR significantly. The CR of lactating dairy cows was negatively affected by heat stress both before and after the day of breeding. The greatest negative impact of heat stress on CR was observed 21 to 1 day before breeding. When the mean THI was 73 or more in this period, CR decreased from 31% to 12%. Compared with the average maximum THI and the total number of hours above a threshold of more than or 9 hours, the mean THI was the most sensitive heat load index relating to CR. These results indicate that the CR of dairy cows raised in the moderate climates is highly affected by heat stress.

  6. Identification of the heat transfer coefficient over the external area of a finned tubes heat exchanger with respect to the moisture content of the air without condensation; Identification du coefficient de transfert thermique sur la surface externe d`un echangeur de chaleur a tubes et ailettes planes en fonction de l`humidite de l`air, en l`absence de condensation

    Energy Technology Data Exchange (ETDEWEB)

    Benelmir, R.; Khalfi, M.; Feidt, M. [Nancy-1 Univ. Henri-Poincare, 54 - Vandoeuvre-les-Nancy (France). Lab. d`energetique et de mecanique theorique et appliquee

    1997-04-01

    The following, which is rather oriented towards experimentation, shows the influence of the humidity content of air on heat transfer. This first article concerns heat transfer between, the external fluid (moist air) and the internal fluid (water containing glycol, whose thermal behavior inside circular tubes is well-known) in a heat exchanger of the same type as those used in automotive air conditioning (horizontal copper tubes and plane aluminium fins), in the absence of condensation. The most difficult part of this experimental work is the measurement and control of the air humidity, since one has to make sure that the measurement in certainties are not significant compared to the precision of the calculation of the heat transfer coefficient. The conclusion is that, for this type of exchanger, the heat transfer coefficient decreases with air humidity in the absence of condensation (dry wall). Some correlations have been developed with respect to the relative air humidity. An analog experimental investigation, but this time carried out in the presence of condensation (partially or completely wetted wall), is about to be completed; the obtained results will be communicated later on. (authors) 15 refs.

  7. Examination of material performance of W exposed to high heat load: Postmortem analysis of W exposed to TEXTOR plasma and E-beam test stand

    Science.gov (United States)

    Tanabe, T.; Philipps, V.; Nakamura, K.; Fujine, M.; Ueda, Y.; Wada, M.; Schweer, B.; Pospieszczyk, A.; Unterberg, B.

    1997-02-01

    We have examined the behavior of high Z limiters exposed to TEXTOR edge plasma and found that under certain conditions high Z materials are compatible with plasmas. In high density Ohmic plasmas the accumulation of a high Z impurity in the plasma center with significant radiation is observed, whereas an auxiliary heating like NBI and ICRH enhances the impurity exhaust with saw tooth activity. For a practical use of high Z plasma facing materials, extremely high heat load from the plasma becomes a serious concern. In the present work we have conducted the high heat load tests of tungsten (W) using two different heat sources, one is the W limiter exposed to TEXTOR plasma and the other is various W samples heat loaded with an intense E-beam using the JEBIS facility in Japan Atomic Energy Research Institute (JAERI). From the test results we have to conclude that W, if applied in the form of the bulk material, should be used above the ductile brittle transition temperature (DBTT) but below about 1500°C to avoid the recrystallization. Maximum heat load tolerable without surface melting is about 20 MW/m 2 for several seconds. The monocrystalline used at high temperatures shows very good performance, though the production of the monocrystalline with a desired shape is not easy. Considering its brittle nature, hard machining and heavy mass, bulk W cannot be a structure material but be used as a thin tile or deposited film on some structure materials. Unfortunately, however, the thermal expansion coefficient of W is so small that brazing of W to a heat sink material like Cu which has a much larger thermal expansion coefficient would easily result in cracking due to the large thermal stress. Thus the development of tungsten plasma facing component (PFC) needs much effort in future.

  8. Effect of volume loading on the Frank-Starling relation during reductions in central blood volume in heat-stressed humans

    DEFF Research Database (Denmark)

    Bundgaard-Nielsen, Morten; Wilson, T E; Seifert, Thomas

    2010-01-01

    During reductions in central blood volume while heat stressed, a greater decrease in stroke volume (SV) for a similar decrease in ventricular filling pressure, compared to normothermia, suggests that the heart is operating on a steeper portion of a Frank-Starling curve. If so, volume loading of h...

  9. Effect of dry heat and steam sterilization on load-deflection characteristics of β-titanium wires: An in vitro study

    Directory of Open Access Journals (Sweden)

    Shiva Alavi

    2012-01-01

    Conclusion: It appears dry heat sterilization increases stiffness of RES, BETA, CNA and HONE but autoclave sterilization did not have any effect on load-deflection characteristics of most of the β-titanium wires tested, indicating that clinicians who want to provide maximum safety for their patients can autoclave TMAL, RES and CNA before applying them.

  10. Heat flow in anharmonic crystals with internal and external stochastic baths: a convergent polymer expansion for a model with discrete time and long range interparticle interaction

    Science.gov (United States)

    Pereira, Emmanuel; Mendonça, Mateus S.; Lemos, Humberto C. F.

    2015-09-01

    We investigate a chain of oscillators with anharmonic on-site potentials, with long range interparticle interactions, and coupled both to external and internal stochastic thermal reservoirs of Ornstein-Uhlenbeck type. We develop an integral representation, a` la Feynman-Kac, for the correlations and the heat current. We assume the approximation of discrete times in the integral formalism (together with a simplification in a subdominant part of the harmonic interaction) and develop a suitable polymer expansion for the model. In the regime of strong anharmonicity, strong harmonic pinning, and for the interparticle interaction with integrable polynomial decay, we prove the convergence of the polymer expansion uniformly in volume (number of sites and time). We also show that the two-point correlation decays in space such as the interparticle interaction. The existence of a convergent polymer expansion is of practical interest: it establishes a rigorous support for a perturbative analysis of the heat flow problem and for the computation of the thermal conductivity in related anharmonic crystals, including those with inhomogeneous potentials and long range interparticle interactions. To show the usefulness and trustworthiness of our approach, we compute the thermal conductivity of a specific anharmonic chain, and make a comparison with related numerical results presented in the literature.

  11. Building America Case Study: Calculating Design Heating Loads for Superinsulated Buildings, Ithaca, New York; Technology Solutions for New and Existing Homes, Energy Efficiency & Renewable Energy (EERE)

    Energy Technology Data Exchange (ETDEWEB)

    None

    2015-08-01

    Designing a superinsulated home has many benefits including improved comfort, reduced exterior noise penetration, lower energy bills, and the ability to withstand power and fuel outages under much more comfortable conditions than a typical home. Extremely low heating and cooling loads equate to much smaller HVAC equipment than conventionally required. Sizing the mechanical system to these much lower loads reduces first costs and the size of the distribution system needed. While these homes aren't necessarily constructed with excessive mass in the form of concrete floors and walls, the amount of insulation and the increase in the thickness of the building envelope can lead to a mass effect, resulting in the structures ability to store much more heat than a code built home. This results in a very low thermal inertia making the building much less sensitive to drastic temperature swings thereby decreasing the peak heating load demand. Alternative methods that take this inertia into account along with solar and internal gains result in smaller more appropriate design loads than those calculated using Manual J version 8. During the winter of 2013/2014, CARB monitored the energy use of three homes in climate zone 6 in an attempt to evaluate the accuracy of two different mechanical system sizing methods for low load homes. Based on the results, it is recommended that internal and solar gains be included and some credit for thermal inertia be used in sizing calculations for superinsulated homes.

  12. Optimised Cockpit Heat Load Analysis using Skin Temperature Predicted by CFD and Validation by Thermal Mapping to Improve the Performance of Fighter Aircraft

    Directory of Open Access Journals (Sweden)

    Paresh Gupta

    2015-03-01

    Full Text Available Designing of optimum environmental control system (ECS plays a major role for increasing performance of fighter aircraft depending upon requirement of engine bleed air for running of ECS. Accurate estimation of cockpit skin temperature for obtaining optimised cockpit heat load helps in estimation of engine bleed air for ECS. Present research evolved a methodology for comparing the theoretically calculated skin temperature with computational fluid dynamics (CFD analysis to obtain optimum skin temperature. Results are validated by flight tests under critical flight conditions using thermal crayons. Based on which the optimized heat load and bleed air requirements has been computed. Uncertainty analysis of skin temperature measurement for thermal crayons have been undertaken. The results indicate that the theoretical skin temperature is -26.70 per cent as that of CFD estimated skin temperature. Optimized average cockpit heat load at critical flight profiles is 0.74 times the theoretical cockpit heat load, leading to reduction of bleed air requirement by 26 per cent as compared to theoretical. Due to this literature survey has pridicted the increase in performance parameters like increase in bleed air pressure by 78 per cent, increase in thrust by 60 per cent, and decrease in specific fuel consumption (SFC by 40 per cent to improve the endurance of aircraft. The research has generated governing equations for variation of cockpit heat loads w.r.t aircraft skin temperatures.Defence Science Journal, Vol. 65, No. 1, January 2015, pp.12-24, DOI:http://dx.doi.org/10.14429/dsj.65.7200

  13. Near-infrared dye loaded polymeric nanoparticles for cancer imaging and therapy and cellular response after laser-induced heating

    Directory of Open Access Journals (Sweden)

    Tingjun Lei

    2014-03-01

    Full Text Available Background: In the past decade, researchers have focused on developing new biomaterials for cancer therapy that combine imaging and therapeutic agents. In our study, we use a new biocompatible and biodegradable polymer, termed poly(glycerol malate co-dodecanedioate (PGMD, for the synthesis of nanoparticles (NPs and loading of near-infrared (NIR dyes. IR820 was chosen for the purpose of imaging and hyperthermia (HT. HT is currently used in clinical trials for cancer therapy in combination with radiotherapy and chemotherapy. One of the potential problems of HT is that it can up-regulate hypoxia-inducible factor-1 (HIF-1 expression and enhance vascular endothelial growth factor (VEGF secretion.Results: We explored cellular response after rapid, short-term and low thermal dose laser-IR820-PGMD NPs (laser/NPs induced-heating, and compared it to slow, long-term and high thermal dose heating by a cell incubator. The expression levels of the reactive oxygen species (ROS, HIF-1 and VEGF following the two different modes of heating. The cytotoxicity of NPs after laser/NP HT resulted in higher cell killing compared to incubator HT. The ROS level was highly elevated under incubator HT, but remained at the baseline level under the laser/NP HT. Our results show that elevated ROS expression inside the cells could result in the promotion of HIF-1 expression after incubator induced-HT. The VEGF secretion was also significantly enhanced compared to laser/NP HT, possibly due to the promotion of HIF-1. In vitro cell imaging and in vivo healthy mice imaging showed that IR820-PGMD NPs can be used for optical imaging.Conclusion: IR820-PGMD NPs were developed and used for both imaging and therapy purposes. Rapid and short-term laser/NP HT, with a low thermal dose, does not up-regulate HIF-1 and VEGF expression, whereas slow and long term incubator HT, with a high thermal dose, enhances the expression of both transcription factors.

  14. Effect of high-flux H/He plasma exposure on tungsten damage due to transient heat loads

    Energy Technology Data Exchange (ETDEWEB)

    De Temmerman, G., E-mail: gregory.detemmerman@iter.org [FOM Institute DIFFER, Dutch Institute for Fundamental Energy Research, Association EURATOM-FOM, Trilateral Euregion Cluster, Postbus 1207, 3430BE Nieuwegein (Netherlands); ITER Organization, Route de Vinon sur Verdon, CS 90 096, 13067 Saint Paul-lez-Durance (France); Morgan, T.W.; Eden, G.G. van; Kruif, T. de [FOM Institute DIFFER, Dutch Institute for Fundamental Energy Research, Association EURATOM-FOM, Trilateral Euregion Cluster, Postbus 1207, 3430BE Nieuwegein (Netherlands); Wirtz, M. [Forschungszentrum Jülich GmbH, Institute of Energy and Climate Research – Microstructure and Properties of Materials (IEK-2), EURATOM Association, 52425 Jülich (Germany); Matejicek, J.; Chraska, T. [Institute of Plasma Physics, Association EURATOM-IPP, CR Prague (Czech Republic); Pitts, R.A. [ITER Organization, Route de Vinon sur Verdon, CS 90 096, 13067 Saint Paul-lez-Durance (France); Wright, G.M. [MIT Plasma Science and Fusion Center, 77 Massachusetts Ave., Cambridge, MA 02139 (United States)

    2015-08-15

    The thermal shock behaviour of tungsten exposed to high-flux plasma is studied using a high-power laser. The cases of laser-only, sequential laser and hydrogen (H) plasma and simultaneous laser plus H plasma exposure are studied. H plasma exposure leads to an embrittlement of the material and the appearance of a crack network originating from the centre of the laser spot. Under simultaneous loading, significant surface melting is observed. In general, H plasma exposure lowers the heat flux parameter (F{sub HF}) for the onset of surface melting by ∼25%. In the case of He-modified (fuzzy) surfaces, strong surface deformations are observed already after 1000 laser pulses at moderate F{sub HF} = 19 MJ m{sup −2} s{sup −1/2}, and a dense network of fine cracks is observed. These results indicate that high-fluence ITER-like plasma exposure influences the thermal shock properties of tungsten, lowering the permissible transient energy density beyond which macroscopic surface modifications begin to occur.

  15. In-Situ Neutron Diffraction Under Tensile Loading of Powder-in-Tube Cu/Nb3Sn Composite Wires Effect of Reaction Heat Treatment on Texture, Internal Stress State and Load Transfer

    CERN Document Server

    Scheuerlein, C; Thilly, L

    2007-01-01

    The strain induced degradation of Nb3Sn superconductors can hamper the performance of high field magnets. We report elastic strain measurements in the different phases of entire non-heat treated and fully reacted Nb3Sn composite strands as a function of uniaxial stress during in-situ deformation under neutron beam. After the reaction heat treatment the Cu matrix loses entirely its load carrying capability and the applied stress is transferred to the remaining Nb-Ta alloy and to the brittle (Nb-Ta)3Sn phase, which exhibits a preferential grain orientation parallel to the strand axis.

  16. ExternE National Implementation Finland

    Energy Technology Data Exchange (ETDEWEB)

    Pingoud, K.; Maelkki, H.; Wihersaari, M.; Pirilae, P. [VTT Energy, Espoo (Finland); Hongisto, M. [Imatran Voima Oy, Vantaa (Finland); Siitonen, S. [Ekono Energy Ltd, Espoo (Finland); Johansson, M. [Finnish Environment Institute, Helsinki (Finland)

    1999-07-01

    ExternE National Implementation is a continuation of the ExternE Project, funded in part by the European Commission's Joule III Programme. This study is the result of the ExternE National Implementation Project for Finland. Three fuel cycles were selected for the Finnish study: coal, peat and wood-derived biomass, which together are responsible for about 40% of total electricity generation in Finland and about 75% of the non-nuclear fuel based generation. The estimated external costs or damages were dominated by the global warming (GW) impacts in the coal and peat fuel cycles, but knowledge of the true GW impacts is still uncertain. From among other impacts that were valued in monetary terms the human health damages due to airborne emissions dominated in all the three fuel cycles. Monetary valuation for ecosystem impacts is not possible using the ExternE methodology at present. The Meri-Pori power station representing the coal fuel cycle is one of the world's cleanest and most efficient coal-fired power plants with a condensing turbine. The coal is imported mainly from Poland. The estimated health damages were about 4 mECU/kWh, crop damages an order of magnitude lower and damages caused to building materials two orders of magnitude lower. The power stations of the peat and biomass fuel cycles are of CHP type, generating electricity and heat for the district heating systems of two cities. Their fuels are of domestic origin. The estimated health damages allocated to electricity generation were about 5 and 6 mECU/kWh, respectively. The estimates were case-specific and thus an generalisation of the results to the whole electricity generation in Finland is unrealistic. Despite the uncertainties and limitations of the methodology, it is a promising tool in the comparison of similar kinds of fuel cycles, new power plants and pollution abatement technologies and different plant locations with each other. (orig.)

  17. Will we be heating with green electricity tomorrow? The large potential of load-variable private customer tariffs; Heizen wir kuenftig mit Oekostrom? Das grosse Potenzial lastvariabler Privatkundentarife

    Energy Technology Data Exchange (ETDEWEB)

    Zierdt, Tobias; Lang, Dirk [RWE Effizienz GmbH, Dortmund (Germany)

    2012-09-15

    Momentous changes loom ahead for Germany's energy supply system as a result of the energy turnaround. One central question is how load peaks from renewable energy plants can be conveniently accommodated on the demand side. Two research projects are currently being carried out to examine the acceptance of time-variable and load-variable tariffs for private households. First results show that using green electricity for heat generation is significantly more attractive for both customers and energy suppliers than using it to cover day-to-day electricity demand at a later time.

  18. Effect of volume loading on the Frank-Starling relation during reductions in central blood volume in heat-stressed humans.

    Science.gov (United States)

    Bundgaard-Nielsen, M; Wilson, T E; Seifert, T; Secher, N H; Crandall, C G

    2010-09-01

    During reductions in central blood volume while heat stressed, a greater decrease in stroke volume (SV) for a similar decrease in ventricular filling pressure, compared to normothermia, suggests that the heart is operating on a steeper portion of a Frank-Starling curve. If so, volume loading of heat-stressed individuals would shift the operating point to a flatter portion of the heat stress Frank-Starling curve thereby attenuating the reduction in SV during subsequent decreases in central blood volume. To investigate this hypothesis, right heart catheterization was performed in eight males from whom pulmonary capillary wedge pressure (PCWP), central venous pressure and SV (via thermodilution) were obtained while central blood volume was reduced via lower-body negative pressure (LBNP) during normothermia, whole-body heating (increase in blood temperature 1 degrees C), and during whole-body heating after intravascular volume expansion. Volume expansion was accomplished by administration of a combination of a synthetic colloid (HES 130/0.4, Voluven) and saline. Before LBNP, SV was not affected by heating (122 +/- 30 ml; mean +/- s.d.) compared to normothermia (110 +/- 20 ml; P = 0.06). However, subsequent volume loading increased SV to 143 +/- 29 ml (P = 0.003). LBNP provoked a larger decrease in SV relative to the decrease in PCWP during heating (8.6 +/- 1.9 ml mmHg(1)) compared to normothermia (4.5 +/- 3.0 ml mmHg(1), P = 0.02). After volume loading while heat stressed, the reduction in the SV to PCWP ratio during LBNP was comparable to that observed during normothermia (4.8 +/- 2.3 ml mmHg(1); P = 0.78). These data support the hypothesis that a Frank-Starling mechanism contributes to compromised blood pressure control during simulated haemorrhage in heat-stressed individuals, and extend those findings by showing that volume infusion corrects this deficit by shifting the operating point to a flatter portion of the heat stress Frank-Starling curve.

  19. 13000 a current lead with 1.5 W heat load to 4.5 K for the Large Hadron Collider at CERN

    CERN Document Server

    Good, J A; Martini, L

    2000-01-01

    Cryogenic Ltd. and ENEL S.p.A. have collaborated on the design and construction of prototype current leads for the Large Hadron Collider project at CERN, Geneva. The aim is to deliver a direct current of 13 kA into a 4.5 K liquid helium bath with a total heat load of less than 1.5 W. These hybrid leads transport the current via a resistive heat exchanger cooled by a separate source of helium gas in the high temperature region, and below 50 K via self-cooled high temperature superconductor. (6 refs).

  20. Abstract: Magnetic solitons' contribution to the specific heat of (CH3)4NMnCl3 in an external magnetic field

    Science.gov (United States)

    Borsa, F.

    1982-03-01

    It has been shown theoretically that linear magnetic systems with planar anisotropy should display nonlinear excitations, i.e., sine-Gordon solitons upon application of a magnetic field perpendicular to the chain axis. Experimental evidence for ID magnetic solitons has been presented for TMMC from neutron scattering and NMR measurements.1 The classical statistical mechanics of this system predict a soliton contribution to the free energy and thus to the specific heat.2 In order to test experimentally the thermodynamic relevance of magnetic solitons, I performed measurements of specific heat in single crystal TMMC in an external magnetic field up to 10 Tesla, applied both perpendicular and parallel to the chain. The measurements were performed with an adiabatic calorimeter in the temperature range 1.5-15 °K. The results show an extra contribution for H⊥c not present for H∥c. This contribution displays a broad maximum which scales approximately as H/T in agreement with the theory. The maximum occurs just above the peak in the specific heat which is observed in correspondence to the three-dimensional transition temperature, and it can be clearly resolved only for H⩾5.0 T. The soliton energy obtained by fitting the experiments to the classical theory is Es = 2.0 H for H = 5.39 T and Es = 1.8 H for H = 10 T to be compared with the theoretical value of Es = gμBHS = 3.35 H and with the value obtained by neutron scattering at H = 3.2 T, i.e., Es = 2.6 H. The discrepancy between theory and experiment is discussed in terms of renormalization corrections and of a possible soliton instability occurring for fields between 3 and 5 T. a)Permanent address: Institut di Fisica, Universita di Pavia, 27100 Pavia, Italy. 1J. P. Boucher, L. P. Regnault, J. Rossad Miguod, J. P. Renard, J. Bouillot, and W. G. Stirling, J. Appl. Phys. 52, 1956 (1981). 2K. M. Leung, D. Hone, D. L. Mills, P. S. Riseborough, and S. E. Trullinger, Phys. Rev. B 21, 4017 (1980).

  1. Cooling Load Distribution of Large Space Building

    Institute of Scientific and Technical Information of China (English)

    CHEN Hong-bing(陈红兵); TU Guang-bei(涂光备); YANG Jie(杨洁); Chan K T

    2003-01-01

    The cooling and heating load distribution of large area air-conditioned room such as "open" offices, shopping malls and waiting rooms is usually assumed to be even in air conditioning system design. However, it is not the case in reality, and a low efficient air conditioning system results from this assumption. A simulation and analysis of the cooling load distribution of an office building in Hong Kong with TRANSYS software is provided in this paper. A typical office is divided into 13 zones for simulation, including external zone, medial zone and internal zone in the north, the south, the east and the west respectively and a central zone, instead of 4 directional zone. The result shows there is much cooling load difference between each zone, and more attention should be paid to uneven indoor cooling and heating load distribution to further guide the design.

  2. The effect of food location, heat load, and intrusive medical procedures on brushing activity in dairy cows.

    Science.gov (United States)

    Mandel, R; Whay, H R; Nicol, C J; Klement, E

    2013-10-01

    Animals allocate time and effort to a range of core (e.g., sleeping, feeding, drinking) and "luxury" (e.g., playing, exploring) activities. A luxury activity is characterized by low resilience and, as such, will be reduced when time or energy resources are limited, including under conditions of stress or discomfort. One seemingly luxurious activity available to cows on an increasing number of dairy farms is rubbing against an automated brush. The current study examined the effect of distance from food, heat load, and an intrusive medical procedure (i.e., artificial insemination and transrectal pregnancy examination) on the resilience of brush usage. The probability of using the brush decreased significantly when food was located distantly from the brush (mean=0.53) compared with days when food was located closer to the brush (mean=0.81). Brush usage also decreased at high temperature and humidity levels, with an average decrease of 0.062 brushing events for an increase of 1 temperature-humidity index unit (95% confidence interval=-0.93-0.030). In addition, a significant reduction of approximately 50% in brushing activity was observed on days of artificial insemination compared with the preceding 3d and the following 3d. These findings show that brush usage is a low resilience activity that reduces under a range of conditions. It may thus have the potential to be used as an indicator of a range of health and welfare problems in cows. Further research should be conducted to assess the sensitivity and specificity of this suggested tool and its possible contribution to the early detection of morbidity.

  3. Simple models of district heating systems for load and demand side management and operational optimisation; Simple modeller for fjernvarmesystemer med henblik pae belastningsudjaevning og driftsoptimering

    Energy Technology Data Exchange (ETDEWEB)

    Boehm, B. [Technical Univ. of Denmark, Dept. of Mechanical Engineering, Kgs. Lyngby (Denmark); Larsen, H.V. [Risoe National Lab., System Analysis Dept., Roskilde (DK)

    2004-12-01

    The purpose of this research project has been to further develop and test simple (aggregated) models of district heating (DH) systems for simulation and operational optimization, and to investigate the influence of Load Management and Demand Side Management (DMS) on the total operational costs. The work is based on physical-mathematical modelling and simulation of DH systems, and is a continuation of previous EFP-96 work. In the present EFP-2001 project the goals have been to improve the Danish method of aggregation by addressing the problem of aggregation of pressure losses, and to test the methods on a much larger data set than in the EFP-1996 project. In order to verify the models it is crucial to have good data at disposal. Full information on the heat loads and temperatures not only at the DH plant but also at every consumer (building) is needed, and therefore only a few DH systems in Denmark can supply such data. (BA)

  4. Damage and fatigue crack growth of Eurofer steel first wall mock-up under cyclic heat flux loads. Part 2: Finite element analysis of damage evolution

    Energy Technology Data Exchange (ETDEWEB)

    You, Jeong-Ha, E-mail: you@ipp.mpg.de

    2014-04-15

    Highlights: • The surface heat flux load of 3.5 MW/m{sup 2} produced substantial stresses and inelastic strains in the heat-loaded surface region, especially at the notch root. • The notch root exhibited a typical notch effect such as stress concentration and localized inelastic yield leading to a preferred damage development. • The predicted damage evolution feature agrees well with the experimental observation. • The smooth surface also experiences considerable stresses and inelastic strains. However, the stress intensity and the amount of inelastic deformation are not high enough to cause any serious damage. • The level of maximum inelastic strain is higher at the notch root than at the smooth surface. On the other hand, the amplitude of inelastic strain variation is comparable at both positions. • The amount of inelastic deformation is significantly affected by the length of pulse duration time indicating the important role of creep. - Abstract: In the preceding companion article (part 1), the experimental results of the high-heat-flux (3.5 MW/m{sup 2}) fatigue tests of a Eurofer bare steel first wall mock-up was presented. The aim was to investigate the damage evolution and crack initiation feature. The mock-up used there was a simplified model having only basic and generic structural feature of an actively cooled steel FW component for DEMO reactor. In that study, it was found that microscopic damage was formed at the notch root already in the early stage of the fatigue loading. On the contrary, the heat-loaded smooth surface exhibited no damage up to 800 load cycles. In this paper, the high-heat-flux fatigue behavior is investigated with a finite element analysis to provide a theoretical interpretation. The thermal fatigue test was simulated using the coupled damage-viscoplastic constitutive model developed by Aktaa. The stresses, inelastic deformation and damage evolution at the notch groove and at the smooth surface are compared. The different

  5. Effect on the load size on the efficiency of microwave heating under stop flow and continuous flow conditions

    NARCIS (Netherlands)

    Patil, N.G.; Rebrov, E.V.; Esveld, D.C.; Eränen, K.; Benaskar, F.; Meuldijk, Jan; Mikkola, J.P.; Hessel, V.; Hulshof, L.A.; Murzin, D.Y.; Schouten, J.C.

    2012-01-01

    A novel heating efficiency analysis of the microwave heated stop-flow (i.e. stagnant
    liquid) and continuous-flow reactors has been presented. The thermal losses to the surrounding
    air by natural convection have been taken into account for heating efficiency calculation of
    the microwave

  6. Effect on the load size on the efficiency of microwave heating under stop flow and continuous flow conditions

    NARCIS (Netherlands)

    Patil, N.G.; Rebrov, E.V.; Esveld, D.C.; Eränen, K.; Benaskar, F.; Meuldijk, Jan; Mikkola, J.P.; Hessel, V.; Hulshof, L.A.; Murzin, D.Y.; Schouten, J.C.

    2012-01-01

    A novel heating efficiency analysis of the microwave heated stop-flow (i.e. stagnant
    liquid) and continuous-flow reactors has been presented. The thermal losses to the surrounding
    air by natural convection have been taken into account for heating efficiency calculation of
    the microwave h

  7. Preliminary analysis of effects of thermal loading on gas and heat flow within the framework of the LBNL/USGS site-scale model

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Y.S.; Chen, G.; Bodvarsson, G.

    1995-12-01

    The US Department of Energy is performing detailed site characterization studies at Yucca Mountain to determine its suitability as a geological repository site for high level nuclear wastes. As part of these research efforts, a three-dimensional, site-scale unsaturated-zone model has been developed at Lawrence Berkeley National Laboratory (LBNL) in collaboration with the US Geological Survey (USGS). The primary objectives of developing the 3-D site-scale model are to predict the ambient hydrogeological conditions and the movement of moisture and gas within the unsaturated zone of the mountain. In addition, the model has the capability of modeling non-isothermal flow and transport phenomena at the mountain. Applications of such a site-scale model should include evaluation of effects of thermal loading on heated gas and heat flow through the mountain for long-term performance assessment of the repository. Emplacement of heat-generating, high-level nuclear wastes at Yucca Mountain would create complex multiphase fluid flow and heat transfer processes. The physical mechanisms include conductive and convective heat transfer, phase change phenomena (vaporization and condensation), flow of liquid and gas phases under variably-saturated condition, diffusion and dispersion of vapor and gas, vapor sorption, and vapor-pressure lowering effects. The heterogeneity of complicated geological setting at Yucca Mountain, such as alternating, layers of porous-fractured rocks, will significantly affect the processes of fluid and heat flow.

  8. Evaluating external nutrient and suspended-sediment loads to Upper Klamath Lake, Oregon, using surrogate regressions with real-time turbidity and acoustic backscatter data

    Science.gov (United States)

    Schenk, Liam N.; Anderson, Chauncey W.; Diaz, Paul; Stewart, Marc A.

    2016-12-22

    Executive SummarySuspended-sediment and total phosphorus loads were computed for two sites in the Upper Klamath Basin on the Wood and Williamson Rivers, the two main tributaries to Upper Klamath Lake. High temporal resolution turbidity and acoustic backscatter data were used to develop surrogate regression models to compute instantaneous concentrations and loads on these rivers. Regression models for the Williamson River site showed strong correlations of turbidity with total phosphorus and suspended-sediment concentrations (adjusted coefficients of determination [Adj R2]=0.73 and 0.95, respectively). Regression models for the Wood River site had relatively poor, although statistically significant, relations of turbidity with total phosphorus, and turbidity and acoustic backscatter with suspended sediment concentration, with high prediction uncertainty. Total phosphorus loads for the partial 2014 water year (excluding October and November 2013) were 39 and 28 metric tons for the Williamson and Wood Rivers, respectively. These values are within the low range of phosphorus loads computed for these rivers from prior studies using water-quality data collected by the Klamath Tribes. The 2014 partial year total phosphorus loads on the Williamson and Wood Rivers are assumed to be biased low because of the absence of data from the first 2 months of water year 2014, and the drought conditions that were prevalent during that water year. Therefore, total phosphorus and suspended-sediment loads in this report should be considered as representative of a low-water year for the two study sites. Comparing loads from the Williamson and Wood River monitoring sites for November 2013–September 2014 shows that the Williamson and Sprague Rivers combined, as measured at the Williamson River site, contributed substantially more suspended sediment to Upper Klamath Lake than the Wood River, with 4,360 and 1,450 metric tons measured, respectively.Surrogate techniques have proven useful at

  9. Technology Solutions Case Study: Air-To-Water Heat Pumps with Radiant Delivery in Low Load Homes, Tucson, Arizona and Chico, California

    Energy Technology Data Exchange (ETDEWEB)

    None

    2013-11-01

    Space conditioning represents nearly 50% of average residential household energy consumption, highlighting the need to identify alternative cost-effective, energy-efficient cooling and heating strategies. As homes are better built, there is an increasing need for strategies that are particularly well suited for high performance, low load homes. ARBI researchers worked with two test homes in hot-dry climates to evaluate the in-situ performance of air-to-water heat pump (AWHP) systems, an energy efficient space conditioning solution designed to cost-effectively provide comfort in homes with efficient, safe, and durable operation. Both systems were fully instrumented and have been monitored over one year to capture complete performance data over the cooling and heating seasons. Results are used to quantify energy savings, cost-effectiveness, and system performance using different operating modes and strategies. This strategy is most effective in tight, insulated homes with high levels of thermal mass (i.e. exposed slab floors).

  10. Generation of Domestic Hot Water, Space Heating and Driving Pattern Profiles for Integration Analysis of Active Loads in Low Voltage Grids

    DEFF Research Database (Denmark)

    Diaz de Cerio Mendaza, Iker; Pigazo, Alberto; Bak-Jensen, Birgitte

    2013-01-01

    demand and electric vehicle driving profiles, to be used for power grid calculations. The generated thermal profiles relied on a statistical analysis made from real domestic hot water and space heating data from 25 households of a typical Danish residential area. The driving profiles instead were formed......The changes in the Danish energy sector, consequence of political agreements, are expected to have direct impact in the actual power distribution systems. Large number of electric boiler, heat pumps and electric vehicles are planned and will cope large percentage of the future power consumption...... at household level. Despite of the well-known flexible service that this kind of loads can provide, their flexibility is highly dependent of the domestic hot water and space heating demand and the driving habits of each user. This paper presents two methodologies employed to randomly generate thermal power...

  11. Study on operating mode of solar-earth source heat pump system with dynamic heating load%基于动态热负荷的太阳能——地源热泵运行模式研究

    Institute of Scientific and Technical Information of China (English)

    李素芬; 韩伟; 代兰花

    2011-01-01

    建立了太阳能-地源热泵系统一体化模型,以大连地区气候条件为基础,计算了供暖季某天内房间热负荷的逐时值.在动态热负荷基础上,对联合供暖系统在不同串联运行模式和并联运行模式不同分流比的运行工况进行了模拟计算,将模拟结果与实脸数据对比,两者吻合较好.结果表明:房间热负荷的变化可影响热泵机组COP.联合运行模式在地温的恢复和系统节能方面均占优势.%An integrative model of the solar-earth source heat pump system (SESHPS) is proposed in this study. Based on the local climate condition (Dalian) , the heat load of heating season by one day iscalculated. The simulation of different series-connected modes is conducted. Furthermore, the simulations are also repeated for different shunt ratio of the same parallel connection mode on the condition of dynamic heating load. The numerical result was compared with the experimental data and they agree with each other very well. The result indicates that COP is disturbed by the change of the heating load and the recovery of ground temperature and the energy efficiency is excellent in the joint operation mode.

  12. Numerical Research of External Heat Transfer for Heavy Gas Turbine Blade%重型燃机透平叶片外壁面换热的数值研究

    Institute of Scientific and Technical Information of China (English)

    慕粉娟; 王思远

    2015-01-01

    开发了重型燃机叶片的外换热及气膜修正程序,对某重型燃机的透平第一级静叶片进行了外换热计算,并针对有气膜冷却的叶片对外换热系数进行了修正,分析了不同截面叶型的换热系数分布和湍流度对换热的影响,同时对比了气膜修正前后的换热系数,得到了叶片外部换热特点。%This article developed the external heat transfer program for heavy gas turbine blade ,and calculated the EHTC (external heat transfer coefficients) of some heavy gas turbine first stage stator blade ,corrected the EHTC with the air-film correction program. The distribution of the HTC along the blade profile on different sections was analyzed. The effect of the turbulence intensity on the heat transfer was also discussed. The HTC before and after air-film corrected was compared. Thus, we got the external heat transfer characteristics of blade.

  13. Fundamental optimal relation of a generalized irreversible Carnot heat pump with complex heat transfer law

    Indian Academy of Sciences (India)

    Jun Li; Lingen Chen; Fengrui Sun

    2010-02-01

    The fundamental optimal relation between heating load and coefficient of performance (COP) of a generalized irreversible Carnot heat pump is derived based on a new generalized heat transfer law, which includes the generalized convective heat transfer law and generalized radiative heat transfer law, $q \\varpropto ( T^{n})^{m}$. The generalized irreversible Carnot heat pump model incorporates several internal and external irreversibilities, such as heat resistance, bypass heat leakage, friction, turbulence and other undesirable irreversibility factors. The added irreversibilities besides heat resistance are characterized by a constant parameter and a constant coefficient. The effects of heat transfer laws and various loss terms are analysed. The heating load vs. COP characteristic of a generalized irreversible Carnot heat pump is a parabolic-like curve, which is consistent with the experimental result of thermoelectric heat pump. The obtained results include those obtained in many literatures and indicated that the analysis results of the generalized irreversible Carnot heat pump were more suitable for engineering practice than those of the endoreversible Carnot heat pump.

  14. Low-cost multi-vehicle air temperature measurements for heat load assessment in local-scale climate applications

    Science.gov (United States)

    Zuvela-Aloise, Maja; Weyss, Gernot; Aloise, Giulliano; Mifka, Boris; Löffelmann, Philemon; Hollosi, Brigitta; Nemec, Johana; Vucetic, Visnja

    2014-05-01

    In the recent years there has been a strong interest in exploring the potential of low-cost measurement devices as alternative source of meteorological monitoring data, especially in the urban areas where high-density observations become crucial for appropriate heat load assessment. One of the simple, but efficient approaches for gathering large amount of spatial data is through mobile measurement campaigns in which the sensors are attached to driving vehicles. However, non-standardized data collecting procedure, instrument quality, their response-time and design, variable device ventilation and radiation protection influence the reliability of the gathered data. We investigate what accuracy can be expected from the data collected through low-cost mobile measurements and whether the achieved quality of the data is sufficient for validation of the state-of-the-art local-scale climate models. We tested 5 types of temperature sensors and data loggers: Maxim iButton, Lascar EL-USB-2-LCD+ and Onset HOBO UX100-003 as market available devices and self-designed solar powered Arduino-based data loggers combined with the AOSONG AM2315 and Sensirion SHT21 temperature and humidity sensors. The devices were calibrated and tested in stationary mode at the Austrian Weather Service showing accuracy between 0.1°C and 0.8°C, which was mostly within the device specification range. In mobile mode, the best response-time was found for self-designed device with Arduino-based data logger and Sensirion SHT21 sensor. However, the device lacks the mechanical robustness and should be further improved for broad-range applications. We organized 4 measurement tours: two taking place in urban environment (Vienna, Austria in July 2011 and July 2013) and two in countryside with complex terrain of Mid-Adriatic islands (Hvar and Korcula, Croatia in August 2013). Measurements were taken on clear-sky, dry and hot days. We combined multiple devices attached to bicycle and cars with different

  15. MATHEMATICAL MODEL OF THE MOTION OF A LIGHT ATTACK AIRCRAFT WITH EXTERNAL LOAD SLINGS IN THE EXTREME AREA OF FLIGHT MODES ACCORDING TO THE ANGLE OF ATTACK

    Directory of Open Access Journals (Sweden)

    A. Popov Sergey

    2017-01-01

    Full Text Available For the time being, a combat-capable trainer aircraft has already been used as a light attack aircraft. The quality of mission effectiveness evaluation depends on the degree of relevance of mathematical models used. It is known that the mis- sion efficiency is largely determined by maneuvering capabilities of the aircraft which are realized most fully in extreme angle of attack flight modes. The article presents the study of the effect of Reynolds number, angle of attack and position on the external sling on the parameters characterizing the state of separated-vortex flow, which was conducted using soft- ware complexes such as Solid Works and Ansys Fluent. There given the dependences of the observed parameters for sta- tionary and nonstationary cases of light attack aircraft movement. The article considers the influence of time constants, which characterize the response rate and delaying of separated flow development and attached flow recovery on the state of separated-vortex flow. The author mentions how the speed of angle of attack change influences lift coefficient of a light attack aircraft with external slings due to response rate and delaying of separated flow development and attached flow recovery. The article describes the mathematical model invented by the authors. This is the model of the movements of light attack aircraft with external slings within a vertical flight maneuver, considering the peculiarities of separated-vortex flow. Using this model, there has been obtained the parameters of light attack aircraft output path from the pitch using large an- gles of attack. It is demonstrated that not considering the peculiarities of the separated-vortex flow model of light attack aircraft movements leads to certain increase of height loss at the pullout of the maneuver, which accordingly makes it pos- sible to decrease the height of the beginning of the pullout.

  16. Dynamic responses and influential parameters of reticulated shell subjected to external blast loading%外部爆炸荷载作用下网壳结构的动力响应及其影响参数分析

    Institute of Scientific and Technical Information of China (English)

    翟希梅; 黄明

    2012-01-01

    Finite element software ANSYS/LS-DYNA is used to establish a refined kiewitt8 single-layer reticulated shell finite element model,which contains reticulated shell member, purlin hanger, purlin, rivet and roof boarding to simulate the dynamic responses of a structure subjected to external blast loading by using ALE (Arbitrary-La-grange-Euler) algorithm. The strain rate effect of materials and the inter-collision of the components are considered. The responses of the structure under external eccentric blast loading with varied TNT equivalent weights, explosion point position, section size of reticulated shell bar, rise-span ratio, supporting condition, thickness of roof board-ing, roof boarding load and the form of roof boarding are obtained by the comparison of the plastic strain, the plastic development degree and the displacement of the structure, which could provide a reference for reasonable defense design of reticulated shell structure to resisting blast. The results show that with the changes of each parameter, there are four damage modes of kiewitt8 single-layer reticulated shell under external blast loading, that is intact, local deformation, local damage and total collapse.%运用ANSYS/LS-DYNA动力有限元软件建立了包含网壳杆件、檩托、檩条、铆钉、屋面板在内的精细化K8型单层球面网壳有限元模型,通过选择考虑材料应变率效应的钢材本构关系,采用流固耦合算法并考虑构件相互碰撞影响,对结构在外部爆炸荷载作用下的动力响应进行了数值模拟,获得了TNT炸药当量、爆炸点距离、杆件截面、矢跨比、支承条件、屋面板厚度、屋面荷载及屋面板形式等参数对结构动力响应的影响规律,可为网壳抗爆防护设计提供参考.网壳结构在外部爆炸荷载作用下,随着各参数取值的变化,存在“完好无损、局部凹陷、局部破坏、整体倒塌”四种破坏类型.

  17. 竖向集中荷载作用下体外预应力混凝土连续梁解析解%Vertical Concentrated Load Externally Prestressed Concrete Continuous Beam Analytical Solution

    Institute of Scientific and Technical Information of China (English)

    钟春玲; 叶增; 张云龙

    2012-01-01

    In the prestressed concrete bridge reinforcement, the application of the external prestressed gradually widely. This paper mainly based on differential equation deduced the external prestressed continuous beam in the vertical concentrated load dint method, the analytical solution of the equation. Using this theory calculation in the vertical deflection under concentrated load along the beam long distribution curve and Ansys numerical analysis re- suits are compared, and both have good consistency, it is shown that the result is reasonable and credible. Contrast the result indicates that the analytical solution and can get in the normal service condition the deflection of the con- crete beams, for the future analysis of the external prestressed carbon fiber reinforced the continuous girder provides the foundation.%在预应力混凝土桥梁加固中,体外预应力的应用逐渐广泛.本文主要基于微分方程,推导了体外预应力连续梁在竖向集中荷载作用下力法方程的解析解.利用该理论,计算了在竖向集中荷载作用下的挠度沿梁长的分布曲线,并与Ansys数值分析结果进行了对比,二者具有较好的一致性,说明该计算结果是合理的,可信的.对比结果表明,采用该解析解并能够得到在正常使用状态下混凝土梁的变形情况,为今后分析碳纤维加固体外预应力连续梁提供了基础.

  18. Change in heat load profile for typical Danish multi-storey buildings when energy-renovated and supplied with low-temperature district heating

    DEFF Research Database (Denmark)

    Harrestrup, Maria; Svendsen, Svend

    2013-01-01

    for the future DH-systems and in order to avoid oversized RE-based capacity, a long-term perspective needs to be taken. The results show that it is possible to design the DH-plants based on an average value of the 5 days with highest daily average loads without compromising with indoor thermal comfort. Applying...

  19. Part-Load Performance Prediction and Operation Strategy Design of Organic Rankine Cycles with a Medium Cycle Used for Recovering Waste Heat from Gaseous Fuel Engines

    Directory of Open Access Journals (Sweden)

    Xuan Wang

    2016-07-01

    Full Text Available The Organic Rankine Cycle (ORC is regarded as a suitable way to recover waste heat from gaseous fuel internal combustion engines. As waste heat recovery systems (WHRS have always been designed based on rated working conditions, while engines often work under part-load conditions, it is quite significant to analyze the part-load performance and corresponding operation strategy of ORC systems. This paper presents a dynamic model of ORC with a medium cycle used for a large gaseous fuel engine and analyzes the effect of adjustable parameters on the system performance, giving effective control directions under various conditions. The results indicate that the intermediary fluid mass flow rate has nearly no effect on the output power and thermal efficiency of the ORC, while the mass flow rate of working fluid has a great effect on them. In order to get a better system performance under different working conditions, the system should be operated with the working fluid mass flow rate as large as possible, but with a slight degree of superheating. Then, with the control of constant superheat degree at the end of the heating process, the performance of the combined system that consists of ORC and the engine at steady state under seven typical working conditions is also analyzed. The results indicate that the energy-saving effect of WHRS becomes worse and worse as the working condition decreases. Especially at 40% working condition the WHRS nearly has no energy-saving effect anymore.

  20. Deuterium retention in tungsten under combined high cycle ELM-like heat loads and steady-state plasma exposure

    Directory of Open Access Journals (Sweden)

    A. Huber

    2016-12-01

    Enhanced blister formation has been observed under combined loading conditions at power densities close to the threshold for damaging. It is shown that blisters are not mainly responsible for the pronounced increase of the D retention.

  1. [Analysis of the results of the 2010 External Quality Control Program of the Spanish Society of Infectious Diseases and Clinical Microbiology for HIV-1, HCV, and HBV viral loads].

    Science.gov (United States)

    Orta Mira, Nieves; Serrano, María del Remedio Guna; Martínez, José-Carlos Latorre; Ovies, María Rosario; Poveda, Marta; de Gopegui, Enrique Ruiz; Cardona, Concepción Gimeno

    2011-12-01

    Human immunodeficiency virus type 1 (HIV-1) and hepatitis B (HBV) and C virus (HCV) viral load determinations are among the most important markers for the follow-up of patients infected with these viruses. External quality control tools are crucial to ensure the accuracy of the results obtained by microbiology laboratories. This article summarized the results obtained in the 2010 External Quality Control Program of the Spanish Society of Infectious Diseases and Clinical Microbiology for HIV-1, HCV, and HBV viral loads and HCV genotyping. In the HIV-1 program, a total of five standards were sent. One standard consisted of seronegative human plasma, while the remaining four contained plasma from three different viremic patients, in the range of 3-5 log(10) copies/mL; two of these standards were identical, with the aim of determining repeatability. A significant proportion of the laboratories (22.6% on average) obtained values out of the accepted range (mean ± 0.2 log(10)copies/mL), depending on the standard and on the method used for quantification. Repeatability was very good, with up to 95% of laboratories reporting results within the limits (Δ<0.5 log(10)copies/mL). The HBV and HCV program consisted of two standards with different viral load contents. Most of the participants, 86.1% in the case of HCV and 87.1% in HBV, obtained all the results within the accepted range (mean ± 1.96 SD log(10)UI/mL). Post-analytical errors due to mistranscription of the results were detected in these controls. Data from this analysis reinforce the utility of proficiency programs to ensure the quality of the results obtained by a particular laboratory, as well as the importance of the post-analytical phase in overall quality. Due to interlaboratory variability, use of the same method and the same laboratory for patient follow-up is advisable.

  2. Effect of Traction Angle on the External Work Performed During Running in Weightlessness on a Treadmill Equipped with a Subject Loading System

    Science.gov (United States)

    Gosseye, T. P.; Willems, P. A.; Heglund, N. C.

    2008-06-01

    During long duration spaceflight, astronauts regularly run on a treadmill-gravity simulator to mitigate bone and muscle loss. This study compares the biomechanics of running on a treadmill-gravity simulator during parabolic flights with the biomechanics of running on Earth. We designed a treadmill equipped with a gravity-like subject pull-down system (SLS) and transducers that measure ground reaction forces and pull-down forces. From these signals we calculate the external work (Wext) to sustain the movements of the center of mass (COM) of the body. In weightlessness, most subjects spontaneously tilt backwards while running. This posture imitates running down a ~2° slope on Earth. Consequently, the Wext is ~15% smaller on the simulator than during level running on Earth. This effect can be avoided by mounting the SLS on mobile chariots that maintain the pull-down force vertical (as in gravity).

  3. Beam induced heat loads on the beam-screens of the twin-bore magnets in the IRs of the HL-LHC

    CERN Document Server

    Iadarola, Giovanni; Rumolo, Giovanni

    2016-01-01

    The expected heat load induced on the beam screens has been evaluated for all the twin-bore magnets in the Insertion Regions (IRs) of the HL-LHC. The contribution from the impedance of the beam screen has been evaluated taking into account the presence of a longitudinal weld in the beam screen and the impact of the temperature and of the magnetic field on the resistivity of the surface. The contribution coming from electron cloud effects has been evaluated for different values of the Secondary Electron Yield of the surface based PyECLOUD build-up simulations.

  4. Motion of a ballistic missile angularly misaligned with the flight path upon entering the atmosphere and its effect upon aerodynamic heating, aerodynamic loads, and miss distance

    Science.gov (United States)

    Allen, Julian H

    1957-01-01

    An analysis is given of the oscillating motion of a ballistic missile which upon entering the atmosphere is angularly misaligned with respect to the flight path. The history of the motion for some example missiles is discussed from the point of view of the effect of the motion on the aerodynamic heating and loading. The miss distance at the target due to misalignment and to small accidental trim angles is treated. The stability problem is also discussed for the case where the missile is tumbling prior to atmospheric entry.

  5. The use of solar simulation systems for producing artificial global radiation for the purpose of determining the heat load of rooms

    Science.gov (United States)

    Kalt, A. C.

    1975-01-01

    Certain climatic tests which require solar and sky radiation were carried out in the laboratory by using simulated global radiation. The advantages of such a method of measurement and the possibilities and limitations resulting from the simulation of global radiation are described. Experiments concerning the thermal load in rooms were conducted in order to test the procedure. In particular, the heat gain through a window with sunshade is discussed, a venetian blind between the panes of a double-glazed window being used in most cases.

  6. CHLORIDE DIFFUSIVITY IN SATURATED CEMENT PASTE SUBJECTED TO EXTERNAL LOADINGS%荷载作用下饱和水泥浆体中氯离子扩散性能研究

    Institute of Scientific and Technical Information of China (English)

    金浏; 杜修力; 张仁波

    2015-01-01

    混凝土类水泥浆复合材料中各种尺度的孔隙,如凝胶孔、毛细孔、掺入的气体气泡以及微裂纹等影响着氯离子的扩散性能.孔隙结构参数(如孔隙率)在外荷载作用下会产生变化,进而影响了水泥浆体中氯离子扩散性能.外荷载作用对氯离子扩散行为的影响,可以等效为外荷载所引起的孔隙率的改变对氯离子扩散性能的影响.从微观角度出发,将饱和水泥浆体看作由水泥浆体基质(其孔隙率为零)和孔隙水夹杂相所组成的两相复合材料介质.基于弹性力学理论推导并获得了饱和水泥浆体达到其强度前(即未产生新裂纹前)当前孔隙率与材料初始孔隙率及体应变之间的定量关系,得到了水泥浆体中氯离子扩散系数与这些参数的定量关系.基于Fick第二定律分析了外荷载(体应变)和孔隙率变化对氯离子扩散性能的影响.研究表明:氯离子在饱和砂浆中的扩散系数随孔隙率增大而显著增大;氯离子在砂浆中的扩散系数随压缩体应变的增大而减小,随拉应变增大而增大.%The chloride diffusivity in cement-based composite materials is affected by multi-scale pores,including gel pores,capillary pores,entrained and entrapped voids,micro-cracks,etc.The pore-structure parameters (e.g.porosity) will change when subjected to external loadings,resulting in the change of the chloride diffusivity in cement paste.The effect of the external loadings on the chloride diffusivity can be assumed as the change of porosity on the chloride diffusivity induced by external loadings.In the present study,saturated cement paste is regarded as a two-phase composite composed of instinct cement matrix (with zero porosity) and pore-water inclusion.Based on the theory of elasticity,the quantitative relationship between current porosity of mortar and initial porosity as well as volumetric strain before reaching the strength of mortar (i.e.before the appearance of new

  7. A novel ultra-high performance liquid chromatography method for the rapid determination of β-lactoglobulin as heat load indicator in commercial milk samples.

    Science.gov (United States)

    Boitz, Lisa I; Fiechter, Gregor; Seifried, Reinhold K; Mayer, Helmut K

    2015-03-20

    The level of undenatured acid-soluble β-lactoglobulin can be used as an indicator to assess the heat load applied to liquid milk, thus further allowing the discrimination between milk originating from different thermal production processes. In this work, a new UHPLC method for the rapid determination of bovine β-lactoglobulin in 1.8min only (total runtime 3min) is presented using simple UV detection at 205nm. Separation selectivity for possibly co-eluting other major whey proteins (bovine serum albumin, lactoferrin, α-lactalbumin, immunoglobulin G) was verified, and the method validated for the analysis of liquid milk samples regarding linearity (20-560μg/mL, R(2)>0.99), instrumentation precision (RSDsESL) milk, quite diverse levels were determined ranging from ∼100 up to 4000mg/L, thus clearly illustrating variable applied heat loads and impacts on the "nativeness" of milk essentially due to the fact that the production technologies used for ESL milk may differ significantly, and are currently not regulated in the EU.

  8. Large-surface-area diamond (111) crystal plates for applications in high-heat-load wavefront-preserving x-ray crystal optics

    CERN Document Server

    Stoupin, S; Butler, J E; Kolyadin, A V; Katrusha, A

    2016-01-01

    We report fabrication and results of high-resolution X-ray topography characterization of diamond single crystal plates with a large surface area (10$\\times$10 mm$^2$) and (111) crystal surface orientation for applications in high-heat-load X-ray crystal optics. The plates were fabricated by laser cutting of the (111) facets of diamond crystals grown using high-pressure high-temperature method. The intrinsic crystal quality of a selected 3$\\times$7~mm$^2$ crystal region of one of the studied samples was found to be suitable for applications in wavefront-preserving high-heat-load crystal optics. The wavefront characterization was performed using sequential X-ray diffraction topography in the pseudo plane wave configuration and data analysis using rocking curve topography. The variation of the rocking curve width and peak position measured with a spatial resolution of 13$\\times$13 $\\mu m^2$ over the selected region were found to be less than one microradian.

  9. Manufacture of thick VPS W coatings on relatively large CuZrCr substrate and its steady high heat load performance

    Energy Technology Data Exchange (ETDEWEB)

    Deng, Chunming, E-mail: denghans@126.com; Liu, Min; Yang, Zhenxiao; Deng, Changguang; Zhou, Kesong; Kuang, Ziqi; Zhang, Jifu

    2014-12-15

    W material is considered as one of potential Plasma Facing Materials (PFMs) for its high melting point, excellent stability at elevated temperature, good thermal conductivity, excellent anti-plasma sputtering and low Tritium retention. Functionally graded W/Cu coating was applied on CuCrZr substrate (250 mm × 120 mm × 30 mm) with compositionally gradient W/Cu as bond coat (0.4–0.6 mm) and 1.5 mm thick W coating as top coat via Vacuum Plasma Spraying (VPS) for continuous deposition of 5 h. Microstructure, chemical composition, porosity and adhesive strength for as sprayed thick W coating on the CuCrZr substrate were characterized by means of SEM, ICP-MS, Mercury Intrusion Porosimeter and tensile strength tester. The steady high heat load (HHL) performance for W/Cu functional gradient coating was evaluated by high energy electron beam. The results showed that thick VPS W coated CuCrZr substrate can withstand the steady high heat load at the electron beam power density of 9 MW/m{sup 2} for 1000 cycles.

  10. Large-surface-area diamond (111) crystal plates for applications in high-heat-load wavefront-preserving X-ray crystal optics.

    Science.gov (United States)

    Stoupin, Stanislav; Antipov, Sergey; Butler, James E; Kolyadin, Alexander V; Katrusha, Andrey

    2016-09-01

    Fabrication and results of high-resolution X-ray topography characterization of diamond single-crystal plates with large surface area (10 mm × 10 mm) and (111) crystal surface orientation for applications in high-heat-load X-ray crystal optics are reported. The plates were fabricated by laser-cutting of the (111) facets of diamond crystals grown using high-pressure high-temperature methods. The intrinsic crystal quality of a selected 3 mm × 7 mm crystal region of one of the studied samples was found to be suitable for applications in wavefront-preserving high-heat-load crystal optics. Wavefront characterization was performed using sequential X-ray diffraction topography in the pseudo plane wave configuration and data analysis using rocking-curve topography. The variations of the rocking-curve width and peak position measured with a spatial resolution of 13 µm × 13 µm over the selected region were found to be less than 1 µrad.

  11. Simulation experiment of interaction of plasma facing materials and transient heat loads in ITER divertor by use of magnetized coaxial plasma gun

    Science.gov (United States)

    Nakatsuka, M.; Ando, K.; Higashi, T.; Kikuchi, Y.; Fukumoto, N.; Nagata, M.

    2009-11-01

    Interaction of plasma facing materials and transient head loads such as type I ELMs is one of the critical issues in ITER divertor. The heat load to the ITER divertor during type I ELMs is estimated to be 0.5-3 MJ/m^2 with a pulse length of 0.1-0.5 ms. We have developed a magnetized coaxial plasma gun (MCPG) for the simulation experiment of transient heat load during type I ELMs in ITER divertor. The MCPG has inner and outer electrodes made of stainless steel 304. In addition, the inner electrode is covered with molybdenum so as to suppress the release of impurities from the electrode during the discharge. The diameters of inner and outer electrodes are 0.06 m and 0.14 m, respectively. The power supply for the MCPG is a capacitor bank (7 kV, 1 mF, 25 kJ). The plasma velocity estimated by the time of flight measurement of the magnetic fields was about 50 km/s, corresponding to the ion energy of 15 eV (H) or 30 eV (D). The absorbed energy density of the plasma stream was measured a calorimeter made of graphite. It was found that the absorbed energy density was 0.9 MJ/m^2 with a pulse width of 0.5 ms at the distance of 100 mm from the inner electrode. In the conference, experimental results of plasma exposure on the plasma facing materials in ITER divertor will be shown.

  12. Crack initiation behavior of notched specimens on heat resistant steel under service type loading at high temperature

    Directory of Open Access Journals (Sweden)

    Lu Cui

    2016-10-01

    Full Text Available Cracks at notches deserve special consideration in the design of steam turbine components. This work is addressed to investigate the crack initiation behavior a 10%Cr rotor steel with the help of notched specimens under service-type loading. A significant drifting down of the peak-values of axial deformation under constant amplitude load was observed. Crack initiation was evaluated with the help of the relationship between irreversible deformation energy and cycle number. Further, metallographic examinations were employed to characterize the superposition of creep and fatigue damage mechanisms. Both Neuber-hypothesis and von Mises equivalent strain at notch root were applied for lifetime prediction. Finally, the effectiveness of both methods is validated by comparing with experimental results

  13. External fuel thermionic reactor system.

    Science.gov (United States)

    Mondt, J. F.; Peelgren, M. L.

    1971-01-01

    Thermionic reactors are prime candidates for nuclear electric propulsion. The national thermionic reactor effort is concentrated on the flashlight concept with the external-fuel concept as the backup. The external-fuel concept is very adaptable to a completely modular power subsystem which is attractive for highly reliable long-life applications. The 20- to 25-cm long, externally-fueled converters have been designed, fabricated, and successfully tested with many thermal cycles by electrical heating. However, difficulties have been encountered during encapsulation for nuclear heated tests and none have been started to date. These nuclear tests are required to demonstrate the concept feasibility.

  14. K8型单层球面网壳基于AUTODYN的外爆响应分析%RESPONSES OF SINGLE-LAYER RETICULATED DOMES SUBJECTED TO EXTERNAL BLAST LOADING USING AUTODYN

    Institute of Scientific and Technical Information of China (English)

    杨帆; 支旭东; 范峰

    2015-01-01

    The dynamic responses of single-layer reticulated domes are analyzed through the explicit dynamic finite element software AUTODYN.The load is applied using the FSI method,and the material is adopted using a multi-segment linear model for steel.First,the accuracy is verified by analyzing near-field and far-field explosions.Then the responses of a 20m span reticulated dome are obtained under external blast loading,including the loading spread,change in maximum nodal displacement,and development of plastic members.The laws governing structural response are researched,accounting for the mass of TNT,explosion distance,and explosion height.The results of numerical simulations indicate that AUTODYN can be used to analyze near-field and far-field explosions;the reticulated dome experiences two main shock wave loadings under external blast loading and the maximum nodal displacement occurs at the first shock wave loading;the plasticity development of structural members ends at 0.05 seconds;the structural responses strengthen with the increase of TNT mass and the explosion height,but weaken with the increase of explosion distance.%该文采用显式动力有限元软件AUTODYN对K8型单层球面网壳在外爆荷载下的动态响应进行了研究.数值模拟中采用流固耦合方法施加荷载,钢材采用多段线性模型,首先验证了AUTODYN进行近场爆炸分析和远场爆炸分析的准确性;考察了跨度为20 m的网壳结构在外爆荷载下的荷载传播规律、最大节点位移变化规律以及塑性杆件发展规律,考察了跨度为40 m网壳结构在TNT质量、炸点距离以及炸点高度参数变化下的结构响应规律.数值分析的结果表明:AUTODYN具备准确进行近场爆炸和远场爆炸分析的能力;单层球面网壳在外爆荷载下主要经历两次冲击波荷载,最大节点位移出现在第一次冲击荷载作用时,结构杆件的塑性发展在0.05 s后基本结束;网壳结构的响应随TNT质量增加和

  15. External Heat Transfer in Moist Air and Superheated Steam for Softwood Drying%软木干燥中湿空气和过热蒸汽的外部传热

    Institute of Scientific and Technical Information of China (English)

    PANG Shusheng

    2004-01-01

    In kiln drying of softwood timber, external heat and moisture mass transfer coefficients are important in defining boundary temperature and moisture content at the wood surface. In addition, superheated steam drying of wood is a promising technology but this has not been widely accepted commercially, partially due to the lack of understanding of the drying phenomena occurred during drying. In this work, experimental investigation was performed to quantify the heat transfer between wood surface and surrounding moist air or superheated steam. In the experiment, saturated radiata pine sapwood samples were dried using dry-bulb/wet-bulb temperatures of 60℃/50℃,90℃/60℃, 120℃/70℃, 140℃/90℃, 160℃/90℃, 140℃/100℃ and 160℃/100℃. The last two schedules were for superheated steam drying as the wet-bulb temperature was set at 100℃. The circulation velocity over the board surface was controlled at 4.2 m·s-1. Two additional runs (90℃/60℃) using air velocities of 2.4 m·s-1 and 4.8 m·s-1were performed to check the effect of the circulation velocity. During drying, sample weight and temperatures at wood surface and different depths were continuously measured. From these measurements, changes in wood temperature and moisture content were calculated and external heat-transfer coefficient was determined for both the moist air and the superheated steam drying.

  16. 内外取热器影响装置长周期运行的因素及对策%Effects of Internal and External Heat Exchanger Device for Long Period Operation Factors and Countermeasures

    Institute of Scientific and Technical Information of China (English)

    艾克利; 张玉宝; 康钰海; 李宏; 郭保宏; 安德会

    2012-01-01

    External heat exchanger main failure form of tube bundle leakage and finned tube distortion,the main reason is the erosion wear,corrosion,welding defects and their structure is not reasonable.The paper on the 60 Mt / a device of heavy oil catalytic cracking heat exchanger in the production of the problems in the running process,influence factors,management and technical defects of the effects obtained after analysis,in order to prolong the using life of external heat exchanger,energy saving,promoting device for diesel and jet operation purpose.%内外取热器失效的主要表现形式为管束泄漏和翅片管变形,其主要原因是冲蚀磨损、腐蚀穿孔、焊接缺陷以及结构不合理等。文章就60 Mt/a重油催化裂化装置取热器在生产运行过程中出现的问题、影响因素、管理缺陷以及技改后所取得的成效加以分析,以期延长外取热器使用寿命,节能降耗,促进装置安稳长满优运行的目的。

  17. Heat transfer through a well insulated external wooden frame wall. An investigation of the effects of normal defects in the insulation resulting from incident wind and air flow through the wall

    Energy Technology Data Exchange (ETDEWEB)

    Roots, P.

    1997-05-01

    The heat requirement of a building can turn out to be greater than was calculated at the design stage. The reason for this may be that heat transport through the building envelope is greater than expected. This in turn can be due to the structure not fulfilling the design requirements in respect to windtightness and airtightness. In addition, there may be defects in the quality of the workmanship of the insulation that significantly reduce the thermal resistance of the external wall. The objective of this investigation has been to ascertain how normal variations in the insulation can affect heat transport through a well-insulated wooden frame external wall under the influences of incident wind or wind flow through the wall. These `normal variations` have been taken to be the presence of electrical conduits, breaks in the insulation, airgaps and nogging pieces, either singly or in combination. For incident wind, measurements in a hotbox and theoretical simulations have shown that the presence of electrical conduits, breaks in the insulation, airgaps or nogging pieces in a well-insulated wooden frame external wall, whether singly or in combination, have negligible effect on thermal transport when subjected to incidnet wind. Heat transport is affected, however, by the presence of a break in the insulation: the combination of electrical conduits, airgaps, a nogging piece and a 16 mm gap in the insulation increased the U-value of the wall by 0.028 W/(m{sup 2.}K) at the most. Measuring the effects of a flow of air through the insulation involved simulating a break in the air seal. A pressure difference of between 10 Pa and 20 Pa was established, causing air to flow from the cold side to the warm side. Measurements and calculations have shown that normal variations in the insulation have a negligible effect on the transmission losses on the cold side, due to the heat exchange effect of the insulation, which raises the temperature of the air flowing through it. This has

  18. Efeitos do peso externo nos chutes espontâneos de lactentes nos primeiros dois meses de vida Effects of external load on spontaneous kicking by one and two-month-old infants

    Directory of Open Access Journals (Sweden)

    JF Landgraf

    2008-12-01

    Full Text Available OBJETIVO: Caracterizar o padrão de chutes espontâneos de lactentes nas idades de um e dois meses, bem como verificar se o peso externo modifica o padrão dos chutes nessas idades. MÉTODOS: Oito lactentes foram filmados nas idades de um e dois meses, estando em supino em uma cadeira infantil reclinada a 0º, na qual havia um móbile na extremidade superior e um painel na extremidade inferior. O experimento teve a duração de seis minutos e 20 segundos, durante os quais foram observados os movimentos de chutes nas situações sem e com peso de 1/10 e 1/3 da massa do membro inferior do lactente. Os pesos externos foram adicionados nos tornozelos do lactente. Pela análise das imagens coletadas por filmadoras digitais, foram verificados a freqüência de chutes e de contatos dos pés em um painel, os movimentos uni e bipodais, a preferência podal e o padrão de coordenação intramembro. RESULTADOS: O teste qui-quadrado revelou aumento significativo da freqüência de chutes nas idades de dois meses e nas situações de peso de 1/10 e pós-peso. Na situação de peso de 1/3 da massa do membro, verificaram-se diminuição do contato dos pés no painel e, na idade de dois meses, aumento da freqüência de contatos. Em todas as situações e idades, houve predomínio por chutes unipodais, não havendo preferência por um dos membros. Além disso, o padrão de coordenação intramembro dos chutes foi caracterizado como em-fase em ambas as idades. CONCLUSÕES: Fatores intrínsecos como a idade e extrínsecos como o peso externo referente a 1/10 da massa do membro inferior promoveram o aumento da freqüência dos chutes espontâneos em lactentes nas idades de um e dois meses.OBJECTIVE: To characterize the spontaneous kicking patterns among one and two-month-old infants, and find whether an external load can modify such patterns at this age. METHODS: Eight infants were filmed at the ages of one and two months, while in the supine position in a baby

  19. Measurement of gas species, temperatures, char burnout, and wall heat fluxes in a 200-MW{sub e} lignite-fired boiler at different loads

    Energy Technology Data Exchange (ETDEWEB)

    Li, Zhengqi; Jing, Jianping; Liu, Guangkui; Chen, Zhichao; Liu, Chunlong [School of Energy Science and Engineering, Harbin Institute of Technology, 92, West Dazhi Street, Harbin 150001 (China)

    2010-04-15

    We measured various operational parameters of a 200-MW{sub e}, wall-fired, lignite utility boiler under different loads. The parameters measured were gas temperature, gas species concentration, char burnout, component release rates (C, H and N), furnace temperature, heat flux, and boiler efficiency. Cold air experiments of a single burner were conducted in the laboratory. A double swirl flow pulverized-coal burner has two ring recirculation zones that start in the secondary air region of the burner. With increasing secondary air flow, the air flow axial velocity increases, the maximum values for the radial velocity, tangential velocity, and turbulence intensity all increase, and there are slight increases in the air flow swirl intensity and the recirculation zone size. With increasing load gas, the temperature and CO concentration in the central region of burner decrease, while O{sub 2} concentration, NO{sub x} concentration, char burnout, and component release rates of C, H, and N increase. Pulverized-coal ignites farther into the burner, in the secondary air region. Gas temperature, O{sub 2} concentration, NO{sub x} concentration, char burnout and component release rates of C, H, and N all increase. Furthermore, CO concentration varies slightly and pulverized-coal ignites closer. In the side wall region, gas temperature, O{sub 2} concentration, and NO{sub x} concentration all increase, but CO concentration varies only slightly. In the bottom row burner region the furnace temperature and heat flux increase appreciably, but the increase become more obvious in the middle and top row burner regions and in the burnout region. Compared with a 120-MW{sub e} load, the mean NO{sub x} emission at the air preheater exits for 190-MW{sub e} load increases from 589.5 mg/m{sup 3} (O{sub 2} = 6%) to 794.6 mg/m{sup 3} (O{sub 2} = 6%), and the boiler efficiency increases from 90.73% to 92.45%. (author)

  20. Performance, bioenergetic status, and indicators of oxidative stress of environmentally heat-loaded Holstein cows in response to diets inducing milk fat depression.

    Science.gov (United States)

    Kargar, S; Ghorbani, G R; Fievez, V; Schingoethe, D J

    2015-07-01

    Effects of grain type and dietary oil supplement on production performance, energy balance, metabolic heat production, and markers of liver function of heat-loaded lactating dairy cows were evaluated using 8 multiparous Holstein cows (77.0d in milk) in a duplicated 4×4 Latin square design with a 2×2 factorial arrangement of treatments. Experimental diets contained either ground barley or ground corn supplemented with either fish oil or soybean oil at 2% of dietary dry matter. Mean daily maximum temperature, minimum relative humidity, and maximum temperature-humidity index were 35.3°C, 11.3%, and 77.0, respectively. Dietary treatment did not affect rectal temperature (38.9°C), but respiration rate tended to decrease in cows fed fish oil versus soybean oil. Dry matter intake decreased for the fish oil-supplemented diets (21.1 vs. 24.3kg/d), which was negatively correlated with plasma concentrations of alkaline phosphatase (r=-0.45; n=32) and malondialdehyde (r=-0.26; n=32). Actual milk yield (41.9kg/d) and energy-corrected milk yield (36.6kg/d) were not affected by grain type, whereas feeding fish oil decreased milk yield as compared with soybean oil (40.4 vs. 43.4kg/d). Milk fat depression occurred in all dietary treatments, especially when cows were fed fish oil because of the presence of polyunsaturated FA in the diets. trans-10 C18:1 was negatively correlated with milk fat yield (r=-0.38; n=32). Daily milk cis-9,trans-11 C18:2 secretion was 29.6% less in cows fed barley- versus corn-based diets but 31.8% greater in cows fed fish oil as compared with cows fed soybean oil. Because of a lower dry matter intake, metabolic heat production was decreased in cows fed fish oil relative to cows fed soybean oil. Although feeding fish oil versus soybean oil decreased net energy for both maintenance and lactation, net energy balance remained unchanged across treatments. In vivo plasma lipoperoxidation was greater in cows fed fish oil versus soybean oil, which

  1. Pressure waves in liquid mercury target from pulsed heat loads and the possible way controlling their effects

    Energy Technology Data Exchange (ETDEWEB)

    Ni, L.; Skala, K. [Paul Scherrer Institute, Villingen (Switzerland)

    1996-06-01

    In ESS project liquid metals are selected as the main target for the pulsed spallation neutron source. Since the very high instantaneous energy is deposited on the heavy molten target in a very short period time, pressure waves are generated. They travel through the liquid and cause high stress in the container. Also, additional stress should be considered in the wall which is the result of direct heating of the target window. These dynamic processes were simulated with computational codes with the static response being analized first. The total resulting dynamic wall stress has been found to have exceeded the design stress for the selected container material. Adding a small amount of gas bubbles in the liquid could be a possible way to reduce the pressure waves.

  2. A Multiscale Approach to Deformation and Fracture of Heat-Resistant Steel Under Static and Cyclic Loading

    Directory of Open Access Journals (Sweden)

    Pavlo MARUSCHAK

    2013-03-01

    Full Text Available Regularities of static and cyclic deformation, damage and fracture of heat-resistant steel 25Kh1M1F, based on the approaches of physical mesomechanics and 3D interferometry method, are presented in this paper. The applicability of these techniques for different hierarchy levels of deformation was studied. The investigation of scanning microscope photos was conducted for several dissipative structures, fragmentation of the material, localisation of macrodeformation and subsequent failure on macro- and mesolevel. It is shown that the used modern techniques of experimental analysis are very efficient in understanding deformation and damage evolution in materials.DOI: http://dx.doi.org/10.5755/j01.ms.19.1.3821

  3. Electricity use and load management in electricity heated one-family houses from customer and utility perspective; Effekten av effekten - Elanvaendning och laststyrning i elvaermda smaahus ur kund- och foeretagsperspektiv

    Energy Technology Data Exchange (ETDEWEB)

    Sernhed, Kerstin

    2004-11-01

    Until recently, the increase in electricity demand and peak power demand has been met by expansion of the electricity production. Today, due to the deregulation of the electricity market, the production capacity is decreasing. Therefore, there is a national interest in finding solutions to peak problems also on the demand side. In the studies described here (Study 1 and 2) ten households in electrically heated houses were examined. In 1999 the utility equipped their customers with a remote metering system (CustCom) that has an in-built load control component. In Study 1, the load pattern of ten households was examined by using energy diaries combined with frequent meter readings (every five minutes) of the load demand for heating, hot water service and domestic electricity use. Household members kept energy diaries over a four-day period in January 2004, noting time, activities and the use of household appliances that run on electricity. The analysis showed that the use of heat-producing household appliances, e.g. sauna, washing machine and dryer, appliances used for cooking, dishwasher and extra electric heaters, contribute to the household's highest peaks. Turning on the sauna and at the same time using the shower equates to a peak load of 7-9 kW. This, in addition to the use of electricity for heating and lighting along alongside electricity use for refrigerators and freezers, results in some households reaching their main fuse level (roughly 13,8 kW for a main fuse of 20 A). This means that the domestic use of electricity makes up a considerable part of the highest peak loads in a household, but the highest peaks occur together with the use of electricity for heating and hot water. In the second study, Study 2, the households participated in a load control experiment, in which the utility was able to turn on and switch off the heating and hot water systems remotely, using the CustCom system. Heating and water heaters were switched off for periods of 1

  4. Assessment of external heat transfer coefficient during oocyte vitrification in liquid and slush nitrogen using numerical simulations to determine cooling rates.

    Science.gov (United States)

    Santos, M V; Sansinena, M; Zaritzky, N; Chirife, J

    2012-01-01

    In oocyte vitrification, plunging directly into liquid nitrogen favor film boiling and strong nitrogen vaporization. A survey of literature values of heat transfer coefficients (h) for film boiling of small metal objects with different geometries plunged in liquid nitrogen revealed values between 125 to 1000 W per per square m per K. These h values were used in a numerical simulation of cooling rates of two oocyte vitrification devices (open-pulled straw and Cryotop), plunged in liquid and slush nitrogen conditions. Heat conduction equation with convective boundary condition was considered a linear mathematical problem and was solved using the finite element method applying the variational formulation. COMSOL Multiphysics was used to simulate the cooling process of the systems. Predicted cooling rates for OPS and Cryotop when cooled at -196 degree C (liquid nitrogen) or -207 degree C (average for slush nitrogen) for heat transfer coefficients estimated to be representative of film boiling, indicated lowering the cooling temperature produces only a maximum 10 percent increase in cooling rates; confirming the main benefit of plunging in slush over liquid nitrogen does not arise from their temperature difference. Numerical simulations also demonstrated that a hypothetical four-fold increase in the cooling rate of vitrification devices when plunging in slush nitrogen would be explained by an increase in heat transfer coefficient. This improvement in heat transfer (i.e., high cooling rates) in slush nitrogen is attributed to less or null film boiling when a sample is placed in slush (mixture of liquid and solid nitrogen) because it first melts the solid nitrogen before causing the liquid to boil and form a film.

  5. Relative contributions of external SST forcing and internal atmospheric variability to July-August heat waves over the Yangtze River valley

    Science.gov (United States)

    Chen, Xiaolong; Zhou, Tianjun

    2017-08-01

    The Yangtze River valley (YRV), located in central-eastern China, has witnessed increased numbers of heat waves in the summer since 1951. Knowing what factors control and affect the interannual variability of heat waves, especially distinguishing the contributions of anomalous sea surface temperature (SST) forcings and those of internal modes of variability, is important to improving heat wave prediction. After evaluating 70 members of the atmospheric model intercomparison project (AMIP) experiments from the 25 models that participated in the coupled model intercomparison project phase 5 (CMIP5), 13 high-skill members (HSMs) are selected to estimate the SST-forced variability. The results show that approximately 2/3 of the total variability of the July-August heat waves in the YRV during 1979-2008 can be attributed to anomalous SST forcings, whereas the other 1/3 are due to internal variability. Within the SST-forced component, one-half of the influence is from the impact of the El Niño-Southern Oscillation (ENSO) and the other half is from non-ENSO related SST forcings, specifically, the SST anomalies in the North Pacific and the North Atlantic. Both the decaying El Niño and developing La Niña accompanied by a warm Indian Ocean and cold central Pacific, respectively, are favorable to hotter summers in the YRV because these patterns strengthen and extend the western North Pacific Subtropical High (WNPSH) westwards, for which the decaying ENSO plays a dominant role. The internal variability shows a circumglobal teleconnection in which Rossby waves propagate southeastwards over the Eurasian Continent and strengthen the WNPSH. Atmospheric model sensitivity experiments confirm that non-ENSO SST forcings can modulate the WNPSH and heat wave variability by projecting their influences onto the internal mode.

  6. Radio-frequency triggered heating and drug release using doxorubicin-loaded LSMO nanoparticles for bimodal treatment of breast cancer.

    Science.gov (United States)

    Kulkarni, Vaishnavi M; Bodas, Dhananjay; Dhoble, Deepa; Ghormade, Vandana; Paknikar, Kishore

    2016-09-01

    Radio-frequency responsive nanomaterials combined with drugs for simultaneous hyperthermia and drug delivery are potential anti-cancer agents. In this study, chitosan coated La0.7Sr0.3MnO3 nanoparticles (C-LSMO NPs) were synthesized and characterized by X-ray diffraction, dynamic light scattering, Fourier transform infra red spectroscopy, vibrating sample magnetometer, scanning electron and atomic force microscopy. Under low radio-frequency (365kHz, RF), C-LSMO NPs (90nm) showed good colloidal stability (+22mV), superparamagnetic nature (15.4 emu/g) and heating capacity (57.4W/g SAR value). Chitosan facilitated doxorubicin entrapment (76%) resulted in DC-LSMO NPs that showed drug release upon a 5min RF exposure. MCF-7 and MDA-MB-231 cancer cells responded to a 5min RF exposure in the presence of bimodal DC-LSMO NPs with a significant decrease in viability to 73% and 88% (Pearson correlation, r=1, Pheat shock protein induction, and caspase production triggered apoptotic cell death. Moreover, DC-LSMO NPs successfully restricted the migration of metastatic MDA-MB-231 cancer cells. These data suggest that DC-LSMO NPs are potential bimodal therapeutic agents for cancer treatment and hold promise against disease recurrence and drug resistance.

  7. Automatic External Load Acquisition by Helicopter

    Science.gov (United States)

    1974-11-01

    of the ship relative to the local level will be sensed with the ship’s stable platform or autopilot gyros and the motion signals trans- mitted to...air permeability = 4 x 10~ h<inrys/m _2 1 is the length of the gap = .15 x 10 m £ is in amp-turns for the coil 4 Calculated B = 10 gauss = 1 Tesla

  8. Experimental Study on the Impact of External Geometrical Shape on Free and Forced Convection Time Dependent Average Heat Transfer Coefficient during Cooling Process

    Directory of Open Access Journals (Sweden)

    Sundus Hussein Abd

    2012-01-01

    Full Text Available In this research, an experimental study was conducted to high light the impact of the exterior shape of a cylindrical body on the forced and free convection heat transfer coefficients when the body is hold in the entrance of an air duct. The impact of changing the body location within the air duct and the air speed are also demonstrated. The cylinders were manufactured with circular, triangular and square sections of copper for its high thermal conductivity with appropriate dimensions, while maintaining the surface area of all shapes to be the same. Each cylinder was heated to a certain temperature and put inside the duct at certain locations. The temperature of the cylinder was then monitored. The heat transfer coefficient were then calculated for forced convection for several Reynolds number (4555-18222.The study covered free convection impact for values of Rayleigh number ranging between (1069-3321. Imperical relationships were obtained for all cases of forced and free convection and compared with equations of circular cylindrical shapes found in literature. These imperical equations were found to be in good comparison with that of other sources.

  9. Modeling and Measurements of Heat Transfer Phenomena in Two-Phase PbSn Alloy Solidification in an External Magnetic Field

    Institute of Scientific and Technical Information of China (English)

    P.A.Nikrityuk; K.Eckert; R.Grundmann; B.Willers; S.Eckert

    2003-01-01

    The main aim of this work is to study numerically the influence of an external magnetic field on the solidification processes of two-component materials. Based on the continuum model of two-phase flow a mathematical model for the directional solidification of a binary alloy in a magnetic field is presented. The model includes mass,momentum, energy and species mass conservation equations written in compressible form and additional relationships describing the temperature-solute coupling. The geometry under study is a cylindrical mold with adiabatic walls and cooled bottom. The macroscale transport in the solidification of alloys is governed by the progress of the two-phase mushy zone, which is treated by means of a porous medium approach. The volume fraction of liquid and solid phases, respectively, is calculated from a 2D approximation of the phase diagram. The results of calculation are compared with experimental data.

  10. Modeling and measurements of heat transfer phenomena in two-phase PbSn alloy solidification in an external magnetic field

    Science.gov (United States)

    Nikrityuk, P. A.; Eckert, K.; Grundmann, R.; Willers, B.; Eckert, S.

    2003-11-01

    The main aim of this work is to study numerically the influence of an external magnetic field on the solidification processes of two-component materials. Based on the continuum model of two-phase flow a mathematical model for the directional solidification of a binary alloy in a magnetic field is presented. The model includes mass, momentum, energy and species mass conservation equations written in compressible form and additional relationships describing the temperature-solute coupling. The geometry under study is a cylindrical mold with adiabatic walls and cooled bottom. The macroscale transport in the solidification of alloys is governed by the progress of the two-phase mushy zone, which is treated by means of a porous medium approach. The volume fraction of liquid and solid phases, respectively, is calculated from a 2D approximation of the phase diagram. The results of calculation are compared with experimental data.

  11. Short-term forecasts of district heating load and outdoor temperature by use of on-line connected computers; Korttidsprognoser foer fjaerrvaermelast och utetemperatur med on-linekopplade datorer

    Energy Technology Data Exchange (ETDEWEB)

    Malmstroem, B.; Ernfors, P.; Nilsson, Daniel; Vallgren, H. [Chalmers Tekniska Hoegskola, Goeteborg (Sweden). Institutionen foer Energiteknik

    1996-10-01

    In this report the available methods for forecasting weather and district heating load have been studied. A forecast method based on neural networks has been tested against the more common statistical methods. The accuracy of the weather forecasts from the SMHI (Swedish Meteorological and Hydrological Institute) has been estimated. In connection with these tests, the possibilities of improving the forecasts by using on-line connected computers has been analysed. The most important results from the study are: Energy company staff generally look upon the forecasting of district heating load as a problem of such a magnitude that computer support is needed. At the companies where computer calculated forecasts are in use, their accuracy is regarded as quite satisfactory; The interest in computer produced load forecasts among energy company staff is increasing; At present, a sufficient number of commercial suppliers of weather forecasts as well as load forecasts is available to fulfill the needs of energy companies; Forecasts based on neural networks did not attain any precision improvement in comparison to more traditional statistical methods. There may though be other types of neural networks, not tested in this study, that are possibly capable of improving the forecast precision; Forecasts of outdoor temperature and district heating load can be significantly improved through the use of on-line-connected computers supplied with instantaneous measurements of temperature and load. This study shows that a general reduction of the load prediction errors by approximately 15% is attainable. For short time horizons (less than 5 hours), more extensive load prediction error reductions can be reached. For the 1-hour time horizon, the possible reduction amounts to up to 50%. 21 refs, 4 figs, 7 appendices

  12. Heat exchanger

    Energy Technology Data Exchange (ETDEWEB)

    Craig, L.B.; Farma, A.J.

    1987-01-06

    This invention concerns a heat exchanger as used in a space heater, of the type in which hot exhaust gases transfer heat to water or the like flowing through a helical heat exchange coil. A significant improvement to the efficiency of the heat exchange occurring between the air and water is achieved by using a conduit for the water having external helical fluting such that the hot gases circulate along two paths, rather than only one. A preferred embodiment of such a heat exchanger includes a porous combustion element for producing radiant heat from a combustible gas, surrounded by a helical coil for effectively transferring the heat in the exhaust gas, flowing radially from the combustion element, to the water flowing through the coil. 4 figs.

  13. Methods for the evaluation of thermal insulation systems and heat bridges of multi-leaf external walls and measures for the reduction of transmission heat losses of facades. Verfahren zur Beurteilung des Waermeschutzes und der Waermebruecken von mehrschaligen Aussenwaenden und Massnahmen zur Verminderung der Transmissionswaermeverluste von Fassaden

    Energy Technology Data Exchange (ETDEWEB)

    Achtziger, J.

    1989-08-01

    When calculating the heat transition coefficient of multi-leaf external walls it shows that particular in case of lightweight metal facades and external walls with coverings the simplified method leads to a too favourable assessment of the building unit and that improvements of the thermal insulation do not have the effect desired. On the basis of exact experimental and arithmetical investigation methods the order of magnitude of the differences from thermal insulation have been found out and also to what extent these can be neglected or have correspondingly to be taken into account. Starting from these results functional influences have been deduced for the different wall constructions. Among the external wall systems investigated were metal constructions and windows, profiled sheet walls and multi-leaf walls of brickwork and of concrete shell as well as wood skeleton and wood panel constructions. The results of these are presented, comparisons are drawn, factors are named which influence the heat transition, the thermal insulation is judged and constructive suggestions for improvements are made. (HWJ).

  14. Fracture toughness of the IEA heat of F82H ferritic/martensitic stainless steel as a function of loading mode

    Energy Technology Data Exchange (ETDEWEB)

    Li, Huaxin; Gelles, D.S. [Pacific Northwest Labs., Richland, WA (United States); Hirth, J.P. [Washington State Univ., Pullman, WA (United States)] [and others

    1997-04-01

    Mode I and mixed-mode I/III fracture toughness tests were performed for the IEA heat of the reduced activation ferritic/martensitic stainless steel F82H at ambient temperature in order to provide comparison with previous measurements on a small heat given a different heat treatment. The results showed that heat to heat variations and heat treatment had negligible consequences on Mode I fracture toughness, but behavior during mixed-mode testing showed unexpected instabilities.

  15. Results of Experimental Investigations to Determine External Tank Protuberance Loads Using a 0.03-Scale Model of the Space Shuttle Launch Configuration (Model 47-OTS) in the NASA/ARC Unitary Plan Wind Tunnel, Volume 2

    Science.gov (United States)

    Houlihan, S. R.

    1992-01-01

    Data were obtained on a 3-percent model of the Space Shuttle launch vehicle in the NASA/Ames Research Center 11x11-foot and 9x7-foot Unitary Plan Wind Tunnels. This test series has been identified as IA19OA/B and was conducted from 7 Feb. 1980 to 19 Feb. 1980 (IA19OA) and from 17 March 1980 to 19 March 1980 and from 8 May 1980 to 30 May 1980 (IA19OB). The primary test objective was to obtain structural loads on the following external tank protuberances: (1) LO2 feedline; (2) GO2 pressure line; (3) LO2 antigeyser line; (4) GH2 pressure line; (5) LH2 tank cable tray; (6) LO2 tank cable tray; (7) Bipod; (8) ET/SRB cable tray; and (9) Crossbeam/Orbiter cable tray. To fulfill these objectives the following steps were taken: Eight 3-component balances were used to measure forces on various sections of 1 thru 6 above; 315 pressure orifices were distributed over all 9 above items. The LO2 feedline was instrumented with 96 pressure taps and was rotated to four positions to yield 384 pressure measurements. The LO2 antigeyser line was instrumented with 64 pressure taps and was rotated to two positions to yield 128 pressure measurements; Three Chrysler miniature flow direction probes were mounted on a traversing mechanism on the tank upper surface centerline to obtain flow field data between the forward and aft attach structures; and Schlieren photographs and ultraviolet flow photographs were taken at all test conditions. Data from each of the four test phases are presented.

  16. Results of experimental investigations to determine external tank protuberance loads using a 0.03-scale model of the Space Shuttle launch configuration (model 47-OTS) in the NASA/ARC unitary plan wind tunnel, volume 1

    Science.gov (United States)

    Houlihan, S. R.

    1992-01-01

    Data were obtained on a 3-percent model of the Space Shuttle launch vehicle in the NASA/Ames Research Center 11x11-foot and 9x7-foot Unitary Plan Wind Tunnels. This test series has been identified as IA190A/B and was conducted from 7 Feb. 1980 to 19 Feb. 1980 (IA190A) and from 17 March 1980 to 19 March 1980 and from 8 May 1980 to 30 May 1980 (IA190B). The primary test objective was to obtain structural loads on the following external tank protuberances: (1) LO2 feedline, (2) GO2 pressure line, (3) LO2 antigeyser line, (4) GH2 pressure line, (5) LH2 tank cable tray, (6) LO2 tank cable tray, (7) Bipod, (8) ET/SRB cable tray, and (9) Crossbeam/Orbiter cable tray. To fulfill these objectives the following steps were taken: (1) Eight 3-component balances were used to measure forces on various sections of 1 thru 6 above. (2) 315 pressure orifices were distributed over all 9 above items. The LO2 feedline was instrumented with 96 pressure taps and was rotated to four positions to yield 384 pressure measurements. The LO2 antigeyser line was instrumented with 64 pressure taps and was rotated to two positions to yield 128 pressure measurements. (3) Three Chrysler miniature flow direction probes were mounted on a traversing mechanism on the tank upper surface centerline to obtain flow field data between the forward and aft attach structures. (4) Schlieren photographs and ultraviolet flow photographs were taken at all test conditions. Data from each of the four test phases are presented.

  17. 水蒸气在竖直微细管外凝结传热特性研究%Research of Condensation Heat Transfer of Wall of Vertical Micro Water Vapor on External Tube

    Institute of Scientific and Technical Information of China (English)

    黄荣海; 陈西平; 严俊杰; 王进仕

    2011-01-01

    This article experimental studied effect of vapor pressure and vapor velocity on the condensation heat transfer characteristics of Saturated vapor on external wall of vertical micro tube(inner and outer diameter were 0.571/0.793 mm) were investigated, and analyzed the effect of vapor pressure and velocity on condensation heat transfer. The experimental result indicated that the condensation heat transfer coefficients increased with increasing vapor velocity, and the heat transfer coefficients increased significantly when the high vapor pressure was high. The result was greater than Nusselt theoretical analysis solution. Condensation heat transfer coefficient almost constant with increasing vapor pressure at the vapor velocity of 2 m.s^-1. However, the condensation heat transfer coefficients increased obviously with increasing vapor pressure when the vapor velocity were 4 m.s^-1 and 6 m.s^-1.%针对不同压力和不同流速下的饱和水蒸气在竖直微细圆管(内外径分别为0.571mm和0.793mm)外的凝结传热特性分别进行了实验研究,分析了蒸气压力和蒸气流速对凝结传热特性的影响。实验结果表明,凝结传热表面传热系数随着蒸气流速的增加而增加,在较高的蒸气压力下增加的更明显,且大于相同实验条件下的Nusselt理论分析解。在蒸气流速为2m·s^-1时,凝结传热系数随压力的变化不大;在4m·s^-1和6m·s^-1时,随着蒸气压力的升高,凝结表面传热系数明显增大。

  18. 无人水下航行器外热源热机用无气体产生燃料%No-gas Generation Fuel Used in External Heat Source Engine of Unmanned Underwear Vehicle(UUV)

    Institute of Scientific and Technical Information of China (English)

    陆宏; 赵熙; 倪亚菲; 邵明臣; 李大鹏

    2015-01-01

    无人水下航行器(UUV)在军事领域正得到愈发广泛的应用,动力装置是其技术难点之一.无人水下航行器采用外热源热机,在续航力和航速上,都优于其他类型动力装置,且使用无气体产生燃料,可从根本上解决水下气体排放问题,提高航行隐蔽性,具有良好的军事应用前景.本文根据无人水下航行器的使用条件和技术要求,对适用于无人水下航行器外热源热机的无气体产生燃料进行了广泛考察,给出了可用于无人水下航行器外热源热机的无气体产生燃料和氧化剂的组合.%Unmanned underwater vehicle(UUV) is applied to the military field more and more widely, of which power plant is one of its technical difficulties. External heat source engine is better than the other types of UUV's power plants by the characters of continuous navigation capacity and navigation velocity. Employment of no-gas generation fuel for the UUV can resolve the problem of gas exhaust underwater and improve navigation stealth. According to technical requirements and working conditions of the UUV, no-gas generation fuels that can be used in the external heat source engine of the UUV are investigated, and used no-gas generation fuels and theirs oxidizers are given in this thesis.

  19. Activated carbon load equalization of gas-phase toluene: effect of cycle length and fraction of time in loading

    Energy Technology Data Exchange (ETDEWEB)

    William M. Moe; Kodi L. Collins; John D. Rhodes [Louisiana State University, Baton Rouge, LA (United States). Department of Civil and Environmental Engineering

    2007-08-01

    Fluctuating pollutant concentrations pose challenges in the design and operation of air pollution control devices such as biofilters. Effective load equalization could decrease or eliminate many of these difficulties. In research described here, experiments were conducted to evaluate effects of cycle length and fraction of time contaminants are supplied on the degree of load equalization achieved by passively operated granular activated carbon (GAC) beds. Columns packed with bituminous coal based Calgon BPL 4 x 6 mesh GAC were subjected to a variety of cyclic loading conditions in which toluene was supplied at concentrations of 1000 or 250 ppmv during loading intervals, and uncontaminated air flowed through the columns during no-loading intervals. The fraction of time when toluene was supplied ranged from 1/2 to 1/6, and cycle lengths ranged from 6 to 48 h. Results demonstrate that passively operated GAC columns can temporarily accumulate contaminants during intervals of high influent concentration and desorb contaminants during intervals of no loading, resulting in appreciable load equalization without need for external regeneration by heating or other means. Greater load equalization was achieved as the fraction of time toluene was loaded decreased and as the cycle length decreased. A pore and surface diffusion model, able to predict the level of contaminant concentration attenuation in GAC columns with reasonable accuracy, was used to further explore the range of load equalization performance expected from columns of various packed bed depths. 19 refs., 6 figs., 1 tab.

  20. The superconducting proposal for the CS magnet system of FAST: a preliminary analysis of the heat load due to AC losses

    CERN Document Server

    Pompeo, N

    2011-01-01

    FAST (Fusion Advanced Studies Torus), the Italian proposal of a Satellite Facility to ITER, is a compact tokamak (R$_0$ = 1.82 m, a = 0.64 m, triangularity $\\delta$ = 0.4) able to investigate non-linear dynamics effects of $\\alpha$-particle behavior in burning plasmas and to test technical solutions for the first wall/divertor directly relevant for ITER and DEMO. Currently, ENEA is investigating the feasibility of a superconducting solution for the magnet system. This paper focuses on the analysis of the CS (Central Solenoid) magnet thermal behavior. In particular, considering a superconducting solution for the CS which uses the room available in the resistive design and referring to one of the most severe scenario envisaged for FAST, the heat load of the CS winding pack due to AC losses is preliminarily evaluated. The results provide a tentative baseline for the definition of the strand requirements and conductor design, that can be accepted in order to fulfil the design requirements.

  1. Coupled calculation of external heat transfer and material temperatures of convection-cooled turbine blades. Final report; Gekoppelte Berechnung des aeusseren Waermeuebergangs und der Materialtemperaturen konvektionsgekuehlter Turbinenschaufeln. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Heselhaus, A.

    1997-05-01

    In this work a hybrid program system consisting of a 3D finite-volume Navier-Stokes flow solver and a 3D finite-element heat conduction solver has been developed. It enables the coupled calculation of structure temperatures in diabatic solid/fluid configurations. The grids of both the finite element and the finite volume computational domain may be completely independent. The coupled program fully resolves the thermal interaction between heat transfer and the resulting material temperatures. The developed coupling algorithm is numerically stable, conservative and works without the need to define ambient temperatures in the flowfield. This allows for the simulation of any solid/fluid configuration. When simulating combined blade/endwall cooling or filmcooling, only a coupled procedure is capable to completely account for the interaction between all relevant thermal parameters. It is found that the coupled calculation of convective cooling in a realistic guide vane leads locally to 45 K higher and 107 K lower blade temperatures than the uncoupled calculation. This shows that accounting for the thermal interaction between the flow and the structure offers both potential to save cooling air and a lower margin of safety when designing cooling systems close to the thermal limits of the blade material. (orig.) [Deutsch] Im Rahmen der vorliegenden Arbeit wurde ein Verfahren zur Berechnung der Temperaturverteilung in diabat umstroemten Koerpern entwickelt, bei dem ein 3D-Finite Volumen Navier-Stokes Stroemungsloeser und ein 3D-Finite Elemente Waermeleitungsloeser zu einem hybriden Programmsystem gekoppelt werden. Dabei besteht die Moeglichkeit, voellig unabhaengige Rechennetze fuer Stroemung und Struktur zu verwenden. Mit dem gekoppelten Verfahren kann die Wechselwirkung zwischen resultierenden Materialtemperaturen und dem davon rueck-beeinflussten Waermeuebergang beruecksichtigt werden. Weiterhin ist der hier entwickelte, stabile und konservative Kopplungsalgorithmus nicht

  2. Effects of high free-flow turbulence, intensive cooling, and wake on the external heat transfer of a gas turbine blade with external heat transfer. Zum Einfluss hoher Freistromturbulenz, intensiver Kuehlung und einer Nachlaufstroemung auf den aeusseren Waermeuebergang einer konvektiv gekuehlten Gasturbinenschaufel

    Energy Technology Data Exchange (ETDEWEB)

    Schulz, A.V.

    1986-04-18

    The effects of free flow turbulence on the heat transfer characteristics of a gas turbine blade with convective cooling are investigated in hot-gas conditions, making a rigid distribution between isotropic turbulence and the free laminar turbulence of a wake flow. The influence of different Reynolds numbers of the grid flow and of different degrees of surface cooling is determined by means of heat transfer experiments with isotropic turbulence generated by quadratic grids. Experimental heat transfer data are compared with the results of a difference boundary layer calculation. The free flow turbulence is determined by laser doppler anemometry while the temperature field is calculated by a finite element method with experimentally determined boundary conditions. Another factor investigated was the effect of a wake on the heat transfer along the blade surface. A turbulent wake was simulated and discussed. (HAG).

  3. External Otitis (Swimmer's Ear)

    Science.gov (United States)

    ... to Pneumococcal Vaccine Additional Content Medical News External Otitis (Swimmer's Ear) By Bradley W. Kesser, MD, Associate ... the Outer Ear Ear Blockages Ear Tumors External Otitis (Swimmer's Ear) Malignant External Otitis Perichondritis External otitis ...

  4. Thermodynamic characteristics of a Brownian heat pump in a spatially periodic temperature field

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    This paper has studied the thermodynamic performance of a thermal Brownian heat pump,which consists of Brownian particles moving at a periodic sawtooth potential with external forces and contacting with the alternating hot and cold reservoirs along the space coordinate.The heat flows driven by both potential and kinetic energies are taken into account.The analytical expressions for the heating load,coefficient of performance(COP) and power input of the Brownian heat pump are derived and the performance characteristics are obtained by numerical calculations.It is shown that due to the heat flow via the change of kinetic energy of the particles,the Brownian heat pump is always irreversible and the COP can never attain the Carnot COP.The study has also investigated the influences of the operating parameters,i.e.the external force,barrier height of the potential,asymmetry of the sawtooth potential and temperature ratio of the heat reservoirs,on the performance of the Brownian heat pump.The effective regions of external force and barrier height of the potential in which the Brownian motor can operates as a heat pump are determined.The results show that the performance of the Brownian heat pump greatly depends on the parameters;if the parameters are properly chosen,the Brownian heat pump may be controlled to operate in the optimal regimes.

  5. Development of a novel method for the exploration of the thermal response of superfluid helium cooled superconducting cables to pulse heat loads

    NARCIS (Netherlands)

    Winkler, T.; Koettig, T.; Weelderen, van R.; Bremer, J.; Brake, ter H.J.M.

    2015-01-01

    Management of transient heat deposition in superconducting magnets and its extraction from the aforementioned is becoming increasingly important to bring high energy particle accelerator performance to higher beam energies and intensities. Precise knowledge of transient heat deposition phenomena in

  6. 基于反向蒙特卡罗法的飞行器在轨外热流计算%On-Orbit External Heat Flux Calculation of Spacecraft Based on Reverse Monte Carlo Method

    Institute of Scientific and Technical Information of China (English)

    潘晴; 王平阳; 包轶颖; 李鹏

    2012-01-01

    为了计算考虑不同纬度和季节下地球反射率和发射率时的在轨外热流,建立了适用于任意地球轨道和飞行姿态条件下的反向蒙特卡罗(RMC)法计算模型.该模型考虑了卫星表面遮挡与多次反射效应,通过连续坐标变换法确定飞行器在给定轨道参数下任意时刻的姿态,并将假设地球辐射特性为常数时的结果与商业软件的计算结果进行比较,以验证模型和计算程序的正确性.在此基础上,考察了地球辐射特性随纬度变化时,飞行器在轨外热流的变化情况.结果表明,所建立的RMC法模型在飞行器姿态控制以及代码计算中具有一定的可靠性;地球反射率和发射率随纬度的变化对地球红外辐射和地球反射辐射的影响均较大,在所选取的轨道参数和抽查时刻,与反射率和发射率不变的结果的最大相对误差分别为一21.31%和80.05%,且均出现于星下点南纬57°;卫星表面遮挡和多次反射效应明显,天线导致其所在平面的地球反射辐射热流密度从19.2W/m^2变化到39.5W/m^2.%In order to calculate the orbit external heat flux in consideration of seasonal and latitudinal variations in earth albedo and emission, the reverse Monte Carlo method model was established which can be used in any kind of earth orbit and aircraft attitude. The model also can take surface covering and multiple reflection into account conveniently. The aircraft attitude was determined in term of the given orbit param eters at any time by continuous coordinate transformation method. The results gained on the constant earth radiation characteristics condition were compared with the results gained by commercial software to verify the accuracy of the model. Then, the orbit external heat flux was computed on varying earth radiation characteristics condition. The results display that the model is reliable to aircraft attitude control and

  7. 竖直微细管外酒精-水蒸气Marangoni凝结传热特性研究%Research on NIarangoni Condensation Heat Transfer of Ethanol-Water Vapor on External Wall of Micro-Vertical Tube

    Institute of Scientific and Technical Information of China (English)

    陈西平; 黄荣海; 严俊杰; 王进仕

    2012-01-01

    In this article the effects of vapor the condensation heat transfer characteristics concentration, vapor pressure and vapor velocity on of ethanol-water mixture vapor on external wall of vertical micro tube(inner and outer diameter were 0.727/1.032 ram) were investigated experimentally. Visual results showed that condensation modes changed with the vapor-to-surface temperature difference. When the vapor-to-surface temperature difference was larger, the condensation modes were typical dropwise condensation. The condensation modes changed to filmwise with decreasing the vapor-to-surface temperature difference. The experimental results indicated that the condensation heat transfer coefficients revealed nonlinear characteristics. The condensation heat transfer coefficient of the ethanol-water mixture was found to have a maximum value of 45 kW·m^-2·K^-1. The heat transfer coefficients increased significantly when the vapor mixture concentrations were lower, and the heat transfer coefficients increased slowly when the vapor mixture concentrations was higher. The condensation heat transfer coefficient increased with the increase of vapor pressure and vapor velocity.%本文搭建了竖直微细管外凝结传热实验台,以酒精水混合蒸气为工质,对不同酒精浓度、不同蒸气流速以及不同蒸气压力下的竖直微细管外(内外径为0.727/1.032mm)Marangoni凝结传热特性进行了研究。可视化结果表明,凝结形态随过冷度的变化有显著变化。在大过冷度时,凝结形态为典型的珠状,随着过冷度逐渐减小,凝结形态由珠状凝结逐渐过渡到膜状凝结。实验结果显示,凝结传热曲线呈现为有峰值的非线性曲线。凝结传热系数最大值为45kW·每m^-2·K^-1,约为纯水3~4倍。凝结传热系数随着过冷度的增加在蒸气浓度低时增加较快,在高浓度时,增加速率较慢。凝结传热系数随蒸气压力或蒸气流速的增加而增加。

  8. Space heat flux simulation and programmable load for thermal test of space optical remote sensor%空间光学遥感器热试验外热流模拟及程控实现

    Institute of Scientific and Technical Information of China (English)

    关奉伟; 刘巨; 于善猛; 黄勇; 崔抗

    2014-01-01

    The whole process of space heat flux analysis, heat flux simulation and programmable load for ther-mal test is expatiated for a given space optical remote sensor working in sun-synchronous orbit.Firstly, space heat flux simulation process of space optical remote sensor is summarized.Secondly, calculation methods of solar radiation, earth albedo and earth infrared radiation are introduced.Thirdly, the space total absorbed heat flux for the given space optical remote sensor is calculated, and the average heat flux of the sunlit area and the shaded area is gained.Finally, the space heat flux simulation method and tactic of thermal test are confirmed, and open-loop control program of programmable power is written using LabVIEW language , and space transient heat loads of thermal test are accurately applied.The results of test indicate that the deviations of applied heat load are within ±2.5%, and the deviations which can meet the requirements of thermal test.%以某太阳同步轨道空间光学遥感器为例,阐述了空间外热流分析计算、热平衡试验外热流模拟以及外热流程控加载的全过程。首先,总结了空间光学遥感器外热流模拟的完整流程。其次,简要介绍了太阳辐射、地球反照、地球红外辐射三种空间外热流的计算方法。然后,对该空间遥感器进行了空间综合吸收外热流计算,获得了阳照区及阴影区外热流平均值。最后,确定了热平衡试验外热流的模拟方法和策略,利用LabVIEW语言编写了程控电源开环控制程序,实现了热试验外热流的准确加载。试验结果表明,外热流值加载偏差在±2.5%以内,满足热平衡试验要求。

  9. External Measures of Cognition

    Directory of Open Access Journals (Sweden)

    Osvaldo eCairo

    2011-10-01

    Full Text Available The human brain is undoubtedly the most impressive, complex and intricate organ that has evolved over time. It is also probably the least understood, and for that reason, the one that is currently attracting the most attention. In fact, the number of comparative analyses that focus on the evolution of brain size in Homo sapiens and other species has increased dramatically in recent years. In neuroscience, no other issue has generated so much interest and been the topic of so many heated debates as the difference in brain size between socially defined population groups, both its connotations and implications. For over a century, external measures of cognition have been related to intelligence. However, it is still unclear whether these measures actually correspond to cognitive abilities. In summary, this paper must be reviewed with this premise in mind.

  10. Thermodynamic cost of external control

    Science.gov (United States)

    Barato, Andre C.; Seifert, Udo

    2017-07-01

    Artificial molecular machines are often driven by the periodic variation of an external parameter. This external control exerts work on the system of which a part can be extracted as output if the system runs against an applied load. Usually, the thermodynamic cost of the process that generates the external control is ignored. Here, we derive a refined second law for such small machines that include this cost, which is, for example, generated by free energy consumption of a chemical reaction that modifies the energy landscape for such a machine. In the limit of irreversible control, this refined second law becomes the standard one. Beyond this ideal limiting case, our analysis shows that due to a new entropic term unexpected regimes can occur: the control work can be smaller than the extracted work and the work required to generate the control can be smaller than this control work. Our general inequalities are illustrated by a paradigmatic three-state system.

  11. Leveraging External Sources of Innovation

    DEFF Research Database (Denmark)

    West, Joel; Bogers, Marcel

    2014-01-01

    This paper reviews research on open innovation that considers how and why firms commercialize external sources of innovations. It examines both the “outside-in” and “coupled” modes of open innovation. From an analysis of prior research on how firms leverage external sources of innovation...... cited work beyond those journals. A review of 291 open innovation-related publications from these sources shows that the majority of these articles indeed address elements of this inbound open innovation process model. Specifically, it finds that researchers have front-loaded their examination...... external innovations create value rather than how firms capture value from those innovations. Finally, the interaction phase considers both feedback for the linear process and reciprocal innovation processes such as cocreation, network collaboration, and community innovation. This review and synthesis...

  12. Effect of heat transfer on the performance of thermoelectric generator-driven thermoelectric refrigerator system

    Science.gov (United States)

    Chen, Lingen; Meng, Fankai; Sun, Fengrui

    2012-01-01

    A model of thermoelectric generator-driven thermoelectric refrigerator with external heat transfer is proposed. The performance of the combined thermoelectric refrigerator device obeying Newton's heat transfer law is analyzed using the combination of finite time thermodynamics and non-equilibrium thermodynamics. Two analytical formulae for cooling load vs. working electrical current, and the coefficient of performance (COP) vs. working electrical current, are derived. For a fixed total heat transfer surface area of four heat exchangers, the allocations of the heat transfer surface area among the four heat exchangers are optimized for maximizing the cooling load and the coefficient of performance (COP) of the combined thermoelectric refrigerator device. For a fixed total number of thermoelectric elements, the ratio of number of thermoelectric elements of the generator to the total number of thermoelectric elements is also optimized for maximizing both the cooling load and the COP of the combined thermoelectric refrigerator device. The influences of thermoelectric element allocation and heat transfer area allocation are analyzed by detailed numerical examples. Optimum working electrical current for maximum cooling load and COP at different total number of thermoelectric elements and different total heat transfer area are obtained, respectively.

  13. Magnetar heating

    CERN Document Server

    Beloborodov, Andrei M

    2016-01-01

    We examine four candidate mechanisms that could explain the high surface temperatures of magnetars. (1) Heat flux from the liquid core heated by ambipolar diffusion. It could sustain the observed surface luminosity $L_s\\approx 10^{35}$ erg s$^{-1}$ if core heating offsets neutrino cooling at a temperature $T_{\\rm core}>6\\times 10^8$ K. This scenario is viable if the core magnetic field exceeds $10^{16}$ G, the magnetar has mass $M10^{16}$ G varying on a 100 meter scale could provide $L_s\\approx 10^{35}$ erg s$^{-1}$. (4) Bombardment of the stellar surface by particles accelerated in the magnetosphere. This mechanism produces hot spots on magnetars. Observations of transient magnetars show evidence for external heating.

  14. Heating load of envelope and energy efficiency correction factor for orientation of civil buildings%民用建筑围护结构负荷与节能朝向修正率

    Institute of Scientific and Technical Information of China (English)

    刘艳峰; 王登甲; 张薇

    2013-01-01

    In the current heating design standard, the value scope of the correction factor for orientation of building envelope heating loads is rather large, and it cannot reflect the differences of solar radiation intensities in various regions which results in that the design calculation results fail to match the respect practical situation. The related energy efficiency design standard does not take the orientation correction into account. Synthetically considering graded solar energy zoning and building thermotechnical design zoning standard, chooses the representative city of every region. Calculates and obtains heating load and energy efficiency correction factors for orientation for wider and more accurate application.%在现行暖通设计规范中,围护结构负荷朝向修正率取值范围较大,且无法体现太阳辐照度地区差异引起的差别,导致不同地区设计计算结果与实际朝向负荷不相符.相关节能设计标准中亦未考虑朝向修正.综合考虑太阳能热能等级分区和建筑热工设计分区划分标准,选取典型城市,计算得到了适用范围广、较准确的负荷朝向修正率和节能朝向修正率.

  15. The External Degree.

    Science.gov (United States)

    Houle, Cyril O.

    This book examines the external degree in relation to the extremes of attitudes, myths, and data. Emphasis is placed on the emergence of the American external degree, foreign external-degree programs, the purpose of the external degree, the current scene, institutional issues, and problems of general policy. (MJM)

  16. Ultimate kinematic characteristics of rail electromagnetic launchers with metal armatures in an external magnetic field

    Science.gov (United States)

    Stankevich, S. V.; Shvetsov, G. A.

    2014-09-01

    This paper presents the results of numerical simulation of the Joule heating of the armature and rails in rail launchers of metal bodies with one or two augmenting rails generating an external magnetic field. The ultimate projectile velocity is calculated under the assumption that the Joule heating of the armature and rails during acceleration does not exceed the melting temperature of the materials of which they are made. It is shown that, with an appropriate choice of the position of the coils generating the augmenting magnetic field with respect to the launcher channel and the current magnitude in them, the heat load on the rails and armature in electromagnetic launchers of solids can be substantially reduced and the ultimate kinematic characteristics of these launchers in crisis-free regimes can be considerably increased.

  17. Comparison of the impact of six heat-load management strategies on thermal responses and milk production of feed-pad and pasture fed dairy cows in a subtropical environment

    Science.gov (United States)

    Davison, T. M.; Jonsson, N. N.; Mayer, D. G.; Gaughan, J. B.; Ehrlich, W. K.; McGowan, M. R.

    2016-05-01

    Exposure to hot environments affects milk yield (MY) and milk composition of pasture and feed-pad fed dairy cows in subtropical regions. This study was undertaken during summer to compare MY and physiology of cows exposed to six heat-load management treatments. Seventy-eight Holstein-Friesian cows were blocked by season of calving, parity, milk yield, BW, and milk protein (%) and milk fat (%) measured in 2 weeks prior to the start of the study. Within blocks, cows were randomly allocated to one of the following treatments: open-sided iron roofed day pen adjacent to dairy (CID) + sprinklers (SP); CID only; non-shaded pen adjacent to dairy + SP (NSD + SP); open-sided shade cloth roofed day pen adjacent to dairy (SCD); NSD + sprinkler (sprinkler on for 45 min at 1100 h if mean respiration rate >80 breaths per minute (NSD + WSP)); open-sided shade cloth roofed structure over feed bunk in paddock + 1 km walk to and from the dairy (SCP + WLK). Sprinklers for CID + SP and NSD + SP cycled 2 min on, 12 min off when ambient temperature >26°C. The highest milk yields were in the CID + SP and CID treatments (23.9 L cow-1 day-1), intermediate for NSD + SP, SCD and SCP + WLK (22.4 L cow-1 day-1), and lowest for NSD + WSP (21.3 L cow-1 day-1) (P data were collected on site at 10-min intervals, and from these, THI was calculated. Nonlinear regression modelling of MY × THI and heat-load management treatment demonstrated that cows in CID + SP showed no decline in MY out to a THI break point value of 83.2, whereas the pooled MY of the other treatments declined when THI >80.7. A combination of iron roof shade plus water sprinkling throughout the day provided the most effective control of heat load.

  18. Optimisation of load control

    Energy Technology Data Exchange (ETDEWEB)

    Koponen, P. [VTT Energy, Espoo (Finland)

    1998-08-01

    Electricity cannot be stored in large quantities. That is why the electricity supply and consumption are always almost equal in large power supply systems. If this balance were disturbed beyond stability, the system or a part of it would collapse until a new stable equilibrium is reached. The balance between supply and consumption is mainly maintained by controlling the power production, but also the electricity consumption or, in other words, the load is controlled. Controlling the load of the power supply system is important, if easily controllable power production capacity is limited. Temporary shortage of capacity causes high peaks in the energy price in the electricity market. Load control either reduces the electricity consumption during peak consumption and peak price or moves electricity consumption to some other time. The project Optimisation of Load Control is a part of the EDISON research program for distribution automation. The following areas were studied: Optimization of space heating and ventilation, when electricity price is time variable, load control model in power purchase optimization, optimization of direct load control sequences, interaction between load control optimization and power purchase optimization, literature on load control, optimization methods and field tests and response models of direct load control and the effects of the electricity market deregulation on load control. An overview of the main results is given in this chapter

  19. Computational Model of Heat Transfer on the ISS

    Science.gov (United States)

    Torian, John G.; Rischar, Michael L.

    2008-01-01

    SCRAM Lite (SCRAM signifies Station Compact Radiator Analysis Model) is a computer program for analyzing convective and radiative heat-transfer and heat-rejection performance of coolant loops and radiators, respectively, in the active thermal-control systems of the International Space Station (ISS). SCRAM Lite is a derivative of prior versions of SCRAM but is more robust. SCRAM Lite computes thermal operating characteristics of active heat-transport and heat-rejection subsystems for the major ISS configurations from Flight 5A through completion of assembly. The program performs integrated analysis of both internal and external coolant loops of the various ISS modules and of an external active thermal control system, which includes radiators and the coolant loops that transfer heat to the radiators. The SCRAM Lite run time is of the order of one minute per day of mission time. The overall objective of the SCRAM Lite simulation is to process input profiles of equipment-rack, crew-metabolic, and other heat loads to determine flow rates, coolant supply temperatures, and available radiator heat-rejection capabilities. Analyses are performed for timelines of activities, orbital parameters, and attitudes for mission times ranging from a few hours to several months.

  20. Optimal usage of low temperature heat sources to supply district heating by heat pumps

    DEFF Research Database (Denmark)

    Pieper, Henrik; Ommen, Torben Schmidt; Markussen, Wiebke Brix

    2017-01-01

    This paper presents a theoretical study on the optimal usage of different low temperature heat sources to supply district heating by heat pumps. The study is based on data for the Copenhagen region. The heat sources were prioritized based on the coefficient of performance calculated for each hour....... Groundwater, seawater and air heat sources were compared with each other as well as to a scenario consisting of a combination of these heat sources. In addition, base load and peak load units were included. Characteristic parameters were the coefficient of performance, the number of full load hours...

  1. The Effect of Condensation in Clothing on Heat Transfer (Het Effect van Condensatie in Kleding op Warmte Afgifte en Warmte Belastheid)

    Science.gov (United States)

    1990-04-02

    to heat. Next was set to zero for treadmill walking and set to the external load during ergometer cycling. B was calculated according to Fanger (1970...during periods of inactivity semipermeable garments allow drying of the underclothing. 37 REFERENCES Fanger , P.O. (1970). Thermal Comfort. McGraw-Hill

  2. NORMATIVE HEAT-TRANSFER COEFFICIENT OF THE RESIDENTIAL BUILDING

    Directory of Open Access Journals (Sweden)

    A. E. Piir

    2015-01-01

    Full Text Available The paper offers a simple but sufficiently accurate technique of the mid-normative heattransfer coefficient for any dwelling house applying the known dimensions, required thermalprotection level and specified facade-glazing portion. The authors present the ascertainment technique of the mid-normative heat-transfer coefficient for a dwelling house with the number of stories from 1 to 16 and the required level of thermal protection. They establish the theoretical dependence and parameters affecting the rate of heat-losses through the external building borders. The article considers the thermal-protection level effect on the heating load and the heating-season fuel consumption rate and finds the correlation between the regulatory requirements to the thermal resistance of certain elements of the building.The authors note the effect of the building geometrical characteristics on the heat-losses rate of the wall portion in the total area of the external borders and its relative quantity as compared with the floor-space of the heated accommodations. The comparison of the specific heat-losses computation results for buildings of 1-, 2-, 4-, 8and 16-storeys with the SNiP 23-02–2003 maximum permissible values show the computational results being less than the maximum values on average by 12 %. This permits recommending the normative heat-transfer coefficient of dwelling houses for evaluating heat-loses at the concept-design stage with the building external-borders engineering constructions being indeterminate or yet under development.

  3. Investigation of a P-96 heat-recovery boiler used as part of the PGU-450T power unit at the Kaliningrad TETs-2 cogeneration station in the course of perfecting the starting and shutdown operations and during running with base loads

    Science.gov (United States)

    Lepaev, P. A.; Shtan', T. P.; Glusker, B. N.; Pashnin, L. V.; Konovalov, P. S.

    2007-09-01

    Results from operational tests carried out on the pilot P-96 heat-recovery boiler of the PGU-450T power unit at the Kaliningrad TETs-2 cogeneration station are presented. Technologies of starting and shutting down the boiler from different thermal states and peculiarities of its operating conditions in the load controlled range are considered. Specific features pertinent to the operation of a horizontal heat-recovery boiler with natural circulation of working medium in the evaporation heating surfaces are established.

  4. Target particle and heat loads in low-triangularity L-mode plasmas in JET with carbon and beryllium/tungsten walls

    NARCIS (Netherlands)

    Groth, M.; Brezinsek, S.; Belo, P.; Corrigan, G.; Harting, D.; Wiesen, S.; Beurskens, M. N. A.; Brix, M.; Clever, M.; Coenen, J. W.; Eich, T.; Flanagan, J.; Giroud, C.; Huber, A.; Jachmich, S.; Kruezi, U.; Lehnen, M.; Lowry, C.; Maggi, C. F.; Marsen, S.; Meigs, A. G.; Sergienko, G.; Sieglin, B.; Silva, C.; Sirinelli, A.; Stamp, M. F.; van Rooij, G. J.

    2013-01-01

    Divertor radiation profiles, and power and particle fluxes to the target have been measured in attached \\{JET\\} L-mode plasmas with carbon and beryllium/tungsten wall materials. In the beryllium/tungsten configuration, factors of 2–3 higher power loads and peak temperatures at the low field side tar

  5. New heating load calculation in practice. DIN 4701 vs. DIN EN 12831; Neue Heizlastberechnung in der Praxis. DIN 4701 vs. DIN EN 12831

    Energy Technology Data Exchange (ETDEWEB)

    Kroeber, C. [Rehau-Akademie Bau, Erlangen (Germany)

    2004-09-15

    DIN EN 12831 is the most controversial technical standard that ever was. The contribution shows the changes from DIN 4701 and their consequences on heating systems and heating grids. (orig.) [German] Wie keine andere Norm, die in den letzten Jahren im Hinblick auf die europaeische Harmonisierung eingefuehrt wurde, sorgt die Heizlastberechnung nach DIN EN 12831 fuer reichlich Gespraechsstoff. In folgendem Beitrag wird beschrieben, welche Veraenderungen im Vergleich zur Waermebedarfsberechnung nach DIN 4701 auftreten und wie sie sich auf die Heizsysteme und Waermeerzeugungsanlagen auswirken. (orig.)

  6. Regulating multiple externalities

    DEFF Research Database (Denmark)

    Waldo, Staffan; Jensen, Frank; Nielsen, Max

    2016-01-01

    Open access is a well-known externality problem in fisheries causing excess capacity and overfishing. Due to global warming, externality problems from CO2 emissions have gained increased interest. With two externality problems, a first-best optimum can be achieved by using two regulatory instrume......Open access is a well-known externality problem in fisheries causing excess capacity and overfishing. Due to global warming, externality problems from CO2 emissions have gained increased interest. With two externality problems, a first-best optimum can be achieved by using two regulatory...

  7. Assessing and Reducing Miscellaneous Electric Loads (MELs) in Lodging

    Energy Technology Data Exchange (ETDEWEB)

    Rauch, Emily M.

    2011-09-01

    Miscellaneous electric loads (MELs) are the loads outside of a building's core functions of heating, ventilating, air conditioning, lighting, and water heating. This report reviews methods to reduce MELs in lodging.

  8. Influence of external flow rates on characteristic equations of absorption chillers; Einfluss variabler Volumenstroeme auf charakteristische Gleichungen fuer Absorptionskaelteanlagen

    Energy Technology Data Exchange (ETDEWEB)

    Ziegler, Felix; Albers, Jan [Technische Univ. Berlin (Germany). Inst. fuer Energietechnik

    2009-04-15

    The method of characteristic equations can be used to describe the performance of absorption chillers in a wide rage of part load conditions as a linear function of a characteristic temperature difference ({delta}{delta}t). This temperature difference combines the external temperatures of hot, chilled and cooling water into one parameter. Normally the achieved part load characteristic is a linear function of {delta}{delta}t provided that the heat transfer coefficients and thus the external flow rates are constant. Nevertheless, this assumption is often not fullfilled under practical conditions. Therefore the classical method has been improved in order to account for variable temperature and flow conditions. Despite of some simplifications the results are in good accordance with measurements. (orig.)

  9. Numerical analysis of influence of heat load on temperature of battery surface with cooling by a two-phase closed thermosyphon

    Directory of Open Access Journals (Sweden)

    Krasnoshlykov Alexander

    2017-01-01

    Full Text Available Numerical analysis of thermal conditions of a two-phase closed thermosyphon using the software package ANSYS FLUENT has been carried out. Time dependence of temperature of heat source surface, which characterize the efficiency of thermosyphon at critical temperatures of batteries have been obtained.

  10. Effect of Pressure Load on Stress Characteristics of the Pre-stressed Heat Exchanger%压力载荷作用对预应力换热器应力特性的影响

    Institute of Scientific and Technical Information of China (English)

    刘义民; 郭崇志

    2016-01-01

    The finite element simulation analysis method was used to numerically calculate the stress of fixed tube heat exchanger. Considering the effect of temperature on the elastic modulus and the pressure load, the stress properties of pre-stressed heat exchanger were researched. Under normal operating conditions, influence of the pressures of tube and shell on the stress of the tube sheet was discussed. Based on a large amount of simulation data, the stress distribution rule for the pressure load on the tube sheet was summarized. Compared with the computational formula of ASME VIII–2, it’s pointed out that the influence of pressure load on the stress of the tube sheet is consistent with the theoretical analysis.%采用有限元数值模拟分析法对固定管板式换热器应力数值计算,考虑温度对材料参数的影响以及压力载荷的作用,探讨预应力换热器的应力特性。在正常操作工况下,讨论管程压力载荷、壳程压力载荷对管板应力的影响,并依据大量的模拟仿真数据总结得到压力载荷对管板的应力变化规律。对比美国 ASME 规范Ⅷ-2中的管板应力计算公式发现,压力载荷对管板应力的影响结果与管板应力计算公式中压力载荷的影响一致。

  11. ASH External Web Portal (External Portal) -

    Data.gov (United States)

    Department of Transportation — The ASH External Web Portal is a web-based portal that provides single sign-on functionality, making the web portal a single location from which to be authenticated...

  12. Target particle and heat loads in low-triangularity L-mode plasmas in JET with carbon and beryllium/tungsten walls

    Energy Technology Data Exchange (ETDEWEB)

    Groth, M., E-mail: mathias.groth@aalto.fi [Aalto University, Association EURATOM-Tekes, Espoo (Finland); Brezinsek, S. [Institute for Energy and Climate Research, Association EURATOM-FZJ Jülich (Germany); Belo, P. [Institute of Plasmas and Nuclear Fusion, Association EURATOM-IST, Lisbon (Portugal); Corrigan, G. [Culham Centre of Fusion Energy, EURATOM-Association, Culham Science Centre, Abingdon (United Kingdom); Harting, D.; Wiesen, S. [Institute for Energy and Climate Research, Association EURATOM-FZJ Jülich (Germany); Beurskens, M.N.A.; Brix, M. [Culham Centre of Fusion Energy, EURATOM-Association, Culham Science Centre, Abingdon (United Kingdom); Clever, M.; Coenen, J.W. [Institute for Energy and Climate Research, Association EURATOM-FZJ Jülich (Germany); Eich, T. [Max-Planck Institute for Plasma Physics, EURATOM-Association, Garching (Germany); Flanagan, J.; Giroud, C. [Culham Centre of Fusion Energy, EURATOM-Association, Culham Science Centre, Abingdon (United Kingdom); Huber, A. [Institute for Energy and Climate Research, Association EURATOM-FZJ Jülich (Germany); Jachmich, S. [Association “EURATOM Belgium State”, Laboratory for Plasma Physics, Brussels (Belgium); Kruezi, U.; Lehnen, M. [Institute for Energy and Climate Research, Association EURATOM-FZJ Jülich (Germany); Lowry, C. [EFDA Close Support Unit, Culham Science Centre, Abingdon (United Kingdom); Maggi, C.F. [Max-Planck Institute for Plasma Physics, EURATOM-Association, Garching (Germany); Marsen, S. [Max-Planck-Institut for Plasma Physics, EURATOM-Association, Greifswald (Germany); and others

    2013-07-15

    Divertor radiation profiles, and power and particle fluxes to the target have been measured in attached JET L-mode plasmas with carbon and beryllium/tungsten wall materials. In the beryllium/tungsten configuration, factors of 2–3 higher power loads and peak temperatures at the low field side target were observed in high-recycling scrape-off layer conditions, whilst in close-to-sheath-limited conditions almost identical plasmas were obtained. The 30% reduction in total radiation with the beryllium/tungsten wall is consistent with a reduction of carbon as the dominant impurity radiator; however similar ion current to the plates, emission from recycling neutrals and neutral pressures in the pumping plenum were measured. Simulations with the EDGDE2/EIRENE code of these plasmas indicate a reduction of the total divertor radiation when carbon is omitted, but significantly higher power loads in high-recycling and detached conditions are predicted than measured.

  13. Fundamental Study of a Combined Hyperthermia System with RF Capacitive Heating and Interstitial Heating

    OpenAIRE

    Saitoh, Yoshiaki; Hori, Junichi; 斉藤, 義明; 堀, 潤一

    2001-01-01

    Interstitial RF heating with an inserted electrode allows the heating position selection in a subject, but the narrow heating region is problematic. This study elucidates development of new interstitial RF heating methods, combining with external RF heating using paired electrodes, heating the subject broadly in advance in order to selectively extend the heating region. Two kinds of heating system were developed by controlling a differential mode and a common mode of RF currents. Heating expe...

  14. Fundamental Study of a Combined Hyperthermia System with RF Capacitive Heating and Interstitial Heating

    OpenAIRE

    Saitoh, Yoshiaki; Hori, Junichi; 斉藤, 義明; 堀, 潤一

    2001-01-01

    Interstitial RF heating with an inserted electrode allows the heating position selection in a subject, but the narrow heating region is problematic. This study elucidates development of new interstitial RF heating methods, combining with external RF heating using paired electrodes, heating the subject broadly in advance in order to selectively extend the heating region. Two kinds of heating system were developed by controlling a differential mode and a common mode of RF currents. Heating expe...

  15. Heat exchanger device and method for heat removal or transfer

    Science.gov (United States)

    Koplow, Jeffrey P [San Ramon, CA

    2012-07-24

    Systems and methods for a forced-convection heat exchanger are provided. In one embodiment, heat is transferred to or from a thermal load in thermal contact with a heat conducting structure, across a narrow air gap, to a rotating heat transfer structure immersed in a surrounding medium such as air.