WorldWideScience

Sample records for heat source based

  1. An MHD heat source based on intermetallic reactions

    Energy Technology Data Exchange (ETDEWEB)

    Sadjian, H.; Zavitsanos, P. (General Sciences, Inc., Souderton, PA (United States)); Marston, C.H. (Villanova Univ., PA (United States))

    1991-05-06

    The main objective of this program was the development of an MHD heat source of potential use in Space - Based Multi Megawatt, MHD Power Systems. The approach is based on extension of high temperature chemical/ion release technology developed by the General Sciences, Incorporated (GSI) team and successfully applied in other Space Applications. Solid state reactions have been identified which can deliver energy densities and electrons in excess of those from high energy explosives as well as other conventional fuels. The use of intermetallic reactions can be used to generate hot hydrogen plasma from the reaction, to create a high level of seedant ionization, can be packaged as a cartridge type fuels for discrete pulses. The estimated weight for energizing a (100 MW - 1000 sec) Pulsed MHD Power System can range from 12 to 25 {times} 10{sup 3} kg depending on reaction system and strength of the magnetic field. The program consisted of two major tasks with eight subtasks designed to systematically evaluate these concepts in order to reduce fuel weight requirements. Laboratory measurements on energy release, reaction product identification and levels of ionization were conducted in the first task to screen candidate fuels. The second task addressed the development of a reaction chamber in which conductivity, temperature and pressure were measured. Instrumentation was developed to measure these parameters under high temperature pulsed conditions in addition to computer programs to reduce the raw data. Measurements were conducted at GSI laboratories for fuel weights of up to 120 grams and at the Franklin Research Center* for fuel weights up to 1 kilogram. The results indicate that fuel weight can be scaled using modular packaging. Estimates are presented for fuel weight requirements. 15 refs.

  2. Experimental investigation and feasibility analysis on a capillary radiant heating system based on solar and air source heat pump dual heat source

    International Nuclear Information System (INIS)

    Zhao, M.; Gu, Z.L.; Kang, W.B.; Liu, X.; Zhang, L.Y.; Jin, L.W.; Zhang, Q.L.

    2017-01-01

    Graphical abstract: (a) Vertical temperature gradient in Case 3, (b) PMV and PPD of the test room in Case 3, (c) operating time of SPCTS and ASHP systems in Case 3 and (d) the proportion of SPCTS operating time. - Highlights: • A capillary heating system based on solar and air source heat pump was developed. • Influence of supply water temperature on solar energy saving rate was investigated. • Heating performance and thermal comfort of capillary heating system were analyzed. • Low temperature heating with capillary is suitable for solar heating system. - Abstract: Due to sustainable development, solar energy has drawn much attention and been widely applied in buildings. However, the application of solar energy is limited because of its instability, intermittency and low energy density in winter. In order to use low density and instable solar energy source for heating and improve the utilization efficiency of solar energy, a solar phase change thermal storage (SPCTS) heating system using a radiant-capillary-terminal (RCT) to effectively match the low temperature hot water, a phase change thermal storage (PCTS) to store and continuously utilize the solar energy, and an air source heat pump (ASHP) as an alternate energy, was proposed and set up in this research. Series of experiments were conducted to obtain the relation between the solar radiation utilization rate and the heating supply temperatures, and to evaluate the performance of the RCT module and the indoor thermal environment of the system for its practical application in a residential building in the north-western City of Xi’an, China. The results show that energy saving of the solar heating system can be significantly improved by reducing the supplied water temperature, and the supplied water temperature of the RCT would be no more than 35 °C. The capillary radiation heating can adopt a lower water temperature and create a good thermal comfort environment as well. These results may lead to the

  3. Dual source heat pump

    Science.gov (United States)

    Ecker, Amir L.; Pietsch, Joseph A.

    1982-01-01

    What is disclosed is a heat pump apparatus for conditioning a fluid characterized by a fluid handler and path for circulating the fluid in heat exchange relationship with a refrigerant fluid; at least two refrigerant heat exchangers, one for effecting heat exchange with the fluid and a second for effecting heat exchange between refrigerant and a heat exchange fluid and the ambient air; a compressor for efficiently compressing the refrigerant; at least one throttling valve for throttling liquid refrigerant; a refrigerant circuit; refrigerant; a source of heat exchange fluid; heat exchange fluid circulating device and heat exchange fluid circuit for circulating the heat exchange fluid in heat exchange relationship with the refrigerant; and valves or switches for selecting the heat exchangers and direction of flow of the refrigerant therethrough for selecting a particular mode of operation. The heat exchange fluid provides energy for defrosting the second heat exchanger when operating in the air source mode and also provides a alternate source of heat.

  4. 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.

  5. A study of Ground Source Heat Pump based on a heat infiltrates coupling model established with FEFLOW

    Science.gov (United States)

    Chen, H.; Hu, C.; Chen, G.; Zhang, Q.

    2017-12-01

    Geothermal heat is a viable source of energy and its environmental impact in terms of CO2 emissions is significantly lower than conventional fossil fuels. it is vital that engineers acquire a proper understanding about the Ground Source Heat Pump (GSHP). In this study, the model of the borehole exchanger under conduction manners and heat infiltrates coupling manners was established with FEFLOW. The energy efficiency, heat transfer endurance and heat transfer in the unit depth were introduced to quantify the energy efficient and the endurance period. The performance of a the Borehole Exchanger (BHE) in soil with and without groundwater seepage was analyzed of heat transfer process between the soil and the working fluid. Basing on the model, the varied regularity of energy efficiency performance an heat transfer endurance with the conditions including the different configuration of the BHE, the soil properties, thermal load characteristic were discussed. Focus on the heat transfer process in multi-layer soil which one layer exist groundwater flow. And an investigation about thermal dispersivity was also analyzed its influence on heat transfer performance. The final result proves that the model of heat infiltrates coupling model established in this context is reasonable, which can be applied to engineering design.

  6. Simulation of a combined heating, cooling and domestic hot water system based on ground source absorption heat pump

    International Nuclear Information System (INIS)

    Wu, Wei; You, Tian; Wang, Baolong; Shi, Wenxing; Li, Xianting

    2014-01-01

    Highlights: • A combined heating/cooling/DHW system based on GSAHP is proposed in cold regions. • The soil imbalance is effectively reduced and soil temperature can be kept stable. • 20% and 15% of condensation/absorption heat is recovered by GSAHP to produce DHW. • The combined system can improve the primary energy efficiency by 23.6% and 44.4%. - Abstract: The amount of energy used for heating and domestic hot water (DHW) is very high and will keep increasing. The conventional ground source electrical heat pump used in heating-dominated buildings has the problems of thermal imbalance, decrease of soil temperature, and deterioration of heating performance. Ground source absorption heat pump (GSAHP) is advantageous in both imbalance reduction and primary energy efficiency (PEE) improvement; however, the imbalance is still unacceptable in the warmer parts of cold regions. A combined heating/cooling/DHW (HCD) system based on GSAHP is proposed to overcome this problem. The GSAHPs using generator absorber heat exchange (GAX) and single-effect (SE) cycles are simulated to obtain the performance under various working conditions. Different HCD systems in Beijing and Shenyang are simulated comparatively in TRNSYS, based on which the thermal imbalance, soil temperature, heat recovery, and energy efficiency are analyzed. Results show that GSAHP–GAX–HCD is suitable for Beijing and GSAHP–SE–HCD is suitable for Shenyang. The imbalance ratio can be reduced to −14.8% in Beijing and to 6.0% in Shenyang with an annual soil temperature variation of only 0.5 °C and 0.1 °C. Furthermore, about 20% and 15% of the total condensation/absorption heat is recovered to produce DHW, and the PEE can reach 1.516 in Beijing and 1.163 in Shenyang. The combined HCD systems can achieve a PEE improvement of 23.6% and 44.4% compared with the normal heating/cooling systems

  7. Research on a Household Dual Heat Source Heat Pump Water Heater with Preheater Based on ASPEN PLUS

    Directory of Open Access Journals (Sweden)

    Xiang Gou

    2016-12-01

    Full Text Available This article proposes a dual heat source heat pump bathroom unit with preheater which is feasible for a single family. The system effectively integrates the air source heat pump (ASHP and wastewater source heat pump (WSHP technologies, and incorporates a preheater to recover shower wastewater heat and thus improve the total coefficient of performance (COP of the system, and it has no electric auxiliary heating device, which is favorable to improve the security of the system operation. The process simulation software ASPEN PLUS, widely used in the design and optimization of thermodynamic systems, was used to simulate various cases of system use and to analyze the impact of the preheater on the system. The average COP value of a system with preheater is 6.588 and without preheater it is 4.677. Based on the optimization and analysis, under the standard conditions of air at 25 °C, relative humidity of 70%, wastewater at 35 °C, wastewater flow rate of 0.07 kg/s, tap water at 15 °C, and condenser outlet water temperature at 50 °C, the theoretical COP of the system can reach 9.784 at an evaporating temperature of 14.96 °C, condensing temperature of 48.74 °C, and preheated water temperature of 27.19 °C.

  8. Thulium-170 heat source

    Science.gov (United States)

    Walter, Carl E.; Van Konynenburg, Richard; VanSant, James H.

    1992-01-01

    An isotopic heat source is formed using stacks of thin individual layers of a refractory isotopic fuel, preferably thulium oxide, alternating with layers of a low atomic weight diluent, preferably graphite. The graphite serves several functions: to act as a moderator during neutron irradiation, to minimize bremsstrahlung radiation, and to facilitate heat transfer. The fuel stacks are inserted into a heat block, which is encased in a sealed, insulated and shielded structural container. Heat pipes are inserted in the heat block and contain a working fluid. The heat pipe working fluid transfers heat from the heat block to a heat exchanger for power conversion. Single phase gas pressure controls the flow of the working fluid for maximum heat exchange and to provide passive cooling.

  9. Radioisotopic heat source

    Science.gov (United States)

    Jones, G.J.; Selle, J.E.; Teaney, P.E.

    1975-09-30

    Disclosed is a radioisotopic heat source and method for a long life electrical generator. The source includes plutonium dioxide shards and yttrium or hafnium in a container of tantalum-tungsten-hafnium alloy, all being in a nickel alloy outer container, and subjected to heat treatment of from about 1570$sup 0$F to about 1720$sup 0$F for about one h. (auth)

  10. Performance of ammonia–water based cycles for power generation from low enthalpy heat sources

    International Nuclear Information System (INIS)

    Mergner, Hanna; Weimer, Thomas

    2015-01-01

    Cost efficient power generation from low temperature heat sources requires an optimal usage of the available heat. In addition to the ORC (Organic Rankine Cycles), cycles with ammonia and water as working fluid show promising results regarding efficiency. Due to their non-isothermal phase change, mixtures can adapt well to a liquid heat source temperature profile and reduce the exergetic losses. In this analysis thermodynamic calculations on the layouts of two existing ammonia–water cycles are compared: a geothermal power plant based on a Siemens’ patent and a modified lab plant based on a patent invented by Kalina (KCS-34). The difference between the two cycles is the position of the internal heat recovery. Cycle simulations were carried out at defined boundary conditions in order to identify optimal operation parameters. For the selected heat source of 393.15 K (hot water) the ammonia mass fraction between 80% and 90% results in the best performance in both configurations. In general, the layout of Siemens achieves a slightly better efficiency compared to the KCS-34. Compared to an ORC using R245fa as working fluid, the exergetic efficiency can be increased by the ammonia/water based cycles by approximately 25%. - Highlights: • Two NH 3 /H 2 O based cycles based on existing plants are analyzed and compared. • A simple KCS-34 focuses on a high enthalpy difference at the turbine. • The Kalina cycle of a Siemens patent KC SG1 runs on a high vapor mass flow. • The layout of the KC SG1 shows slightly better results compared to the KCS-34. • NH 3 /H 2 O cycles show an efficiency increase compared to a regular ORC with R245fa

  11. Protected isotope heat source

    International Nuclear Information System (INIS)

    Burns, R.K.; Shure, L.I.; Katzen, E.D.

    1975-01-01

    A radioactive isotope capsule is disposed in a container (heat shield) which will have a single stable trim attitude when reentering the earth's atmosphere and while falling to earth. The center of gravity of the heat source is located forward of the midpoint between the front face and the rear face of the container. The capsule is insulated from the front face of the container but not from the rear surface of the container. (auth)

  12. Regenerative heat sources for heating networks

    International Nuclear Information System (INIS)

    Huenges, Ernst; Sperber, Evelyn; Eggers, Jan-Bleicke; Noll, Florian; Kallert, Anna Maria; Reuss, Manfred

    2015-01-01

    The ambitious goal, the German Federal Government has set itself, to reduce the emissions of greenhouse gases by 80% to 95% by the year 2050. As there are currently more than half of German energy consumption for the production of heat is required, big contributions to climate protection can be expected from this area if more renewable heat sources are used. Renewable heat sources such as bioenergy, solar thermal and geothermal energy in particular can be provided as compared to fossil fuels with significantly lower specific CO 2 emissions. Objectives in the heating market and scenarios for the transformation of the heat sector have been elaborated in the BMU Lead Study 2011. The main pillar of this scenario is the reduction of final energy consumption for heat by the energy-efficient renovation of existing buildings and further increasing demands on the energetic quality of new buildings. To cover the remaining energy demand, a focus is on the expansion of heating networks based on renewable energies. [de

  13. Fuel fired heat sources

    Energy Technology Data Exchange (ETDEWEB)

    Ortlinghaus, U

    1977-09-08

    Fuel fired heat sources with a valve-controlled ignition and main burner, whose flame is monitored and whose control valve is closed or opened by a controller according to the control deviation between actual and reference heat source temperature, previously suffered the disadvantage of high consumption of ignition gas. According to the invention this disadvantage is avoided by closing the ignition valve from the controller via a delay unit and having the delay time of the delay unit controlled either by the temperature measured by the sensor or increasing it with increasing deviation of the actual value of pre-temperature from the reference value of the pre-temperature.

  14. Energy and exergy analysis of a double effect absorption refrigeration system based on different heat sources

    International Nuclear Information System (INIS)

    Kaynakli, Omer; Saka, Kenan; Kaynakli, Faruk

    2015-01-01

    Highlights: • Energy and exergy analysis was performed on double effect series flow absorption refrigeration system. • The refrigeration system runs on various heat sources such as hot water, hot air and steam. • A comparative analysis was carried out on these heat sources in terms of exergy destruction and mass flow rate of heat source. • The effect of heat sources on the exergy destruction of high pressure generator was investigated. - Abstract: Absorption refrigeration systems are environmental friendly since they can utilize industrial waste heat and/or solar energy. In terms of heat source of the systems, researchers prefer one type heat source usually such as hot water or steam. Some studies can be free from environment. In this study, energy and exergy analysis is performed on a double effect series flow absorption refrigeration system with water/lithium bromide as working fluid pair. The refrigeration system runs on various heat sources such as hot water, hot air and steam via High Pressure Generator (HPG) because of hot water/steam and hot air are the most common available heat source for absorption applications but the first law of thermodynamics may not be sufficient analyze the absorption refrigeration system and to show the difference of utilize for different type heat source. On the other hand operation temperatures of the overall system and its components have a major effect on their performance and functionality. In this regard, a parametric study conducted here to investigate this effect on heat capacity and exergy destruction of the HPG, coefficient of performance (COP) of the system, and mass flow rate of heat sources. Also, a comparative analysis is carried out on several heat sources (e.g. hot water, hot air and steam) in terms of exergy destruction and mass flow rate of heat source. From the analyses it is observed that exergy destruction of the HPG increases at higher temperature of the heat sources, condenser and absorber, and lower

  15. Recovery Act: Finite Volume Based Computer Program for Ground Source Heat Pump Systems

    Energy Technology Data Exchange (ETDEWEB)

    James A Menart, Professor

    2013-02-22

    This report is a compilation of the work that has been done on the grant DE-EE0002805 entitled Finite Volume Based Computer Program for Ground Source Heat Pump Systems. The goal of this project was to develop a detailed computer simulation tool for GSHP (ground source heat pump) heating and cooling systems. Two such tools were developed as part of this DOE (Department of Energy) grant; the first is a two-dimensional computer program called GEO2D and the second is a three-dimensional computer program called GEO3D. Both of these simulation tools provide an extensive array of results to the user. A unique aspect of both these simulation tools is the complete temperature profile information calculated and presented. Complete temperature profiles throughout the ground, casing, tube wall, and fluid are provided as a function of time. The fluid temperatures from and to the heat pump, as a function of time, are also provided. In addition to temperature information, detailed heat rate information at several locations as a function of time is determined. Heat rates between the heat pump and the building indoor environment, between the working fluid and the heat pump, and between the working fluid and the ground are computed. The heat rates between the ground and the working fluid are calculated as a function time and position along the ground loop. The heating and cooling loads of the building being fitted with a GSHP are determined with the computer program developed by DOE called ENERGYPLUS. Lastly COP (coefficient of performance) results as a function of time are provided. Both the two-dimensional and three-dimensional computer programs developed as part of this work are based upon a detailed finite volume solution of the energy equation for the ground and ground loop. Real heat pump characteristics are entered into the program and used to model the heat pump performance. Thus these computer tools simulate the coupled performance of the ground loop and the heat pump. The

  16. Finite Volume Based Computer Program for Ground Source Heat Pump System

    Energy Technology Data Exchange (ETDEWEB)

    Menart, James A. [Wright State University

    2013-02-22

    This report is a compilation of the work that has been done on the grant DE-EE0002805 entitled ?Finite Volume Based Computer Program for Ground Source Heat Pump Systems.? The goal of this project was to develop a detailed computer simulation tool for GSHP (ground source heat pump) heating and cooling systems. Two such tools were developed as part of this DOE (Department of Energy) grant; the first is a two-dimensional computer program called GEO2D and the second is a three-dimensional computer program called GEO3D. Both of these simulation tools provide an extensive array of results to the user. A unique aspect of both these simulation tools is the complete temperature profile information calculated and presented. Complete temperature profiles throughout the ground, casing, tube wall, and fluid are provided as a function of time. The fluid temperatures from and to the heat pump, as a function of time, are also provided. In addition to temperature information, detailed heat rate information at several locations as a function of time is determined. Heat rates between the heat pump and the building indoor environment, between the working fluid and the heat pump, and between the working fluid and the ground are computed. The heat rates between the ground and the working fluid are calculated as a function time and position along the ground loop. The heating and cooling loads of the building being fitted with a GSHP are determined with the computer program developed by DOE called ENERGYPLUS. Lastly COP (coefficient of performance) results as a function of time are provided. Both the two-dimensional and three-dimensional computer programs developed as part of this work are based upon a detailed finite volume solution of the energy equation for the ground and ground loop. Real heat pump characteristics are entered into the program and used to model the heat pump performance. Thus these computer tools simulate the coupled performance of the ground loop and the heat pump

  17. Combined heat and power (cogeneration) plant based on renewable energy sources and electrochemical hydrogen systems

    Science.gov (United States)

    Grigor'ev, S. A.; Grigor'ev, A. S.; Kuleshov, N. V.; Fateev, V. N.; Kuleshov, V. N.

    2015-02-01

    The layout of a combined heat and power (cogeneration) plant based on renewable energy sources (RESs) and hydrogen electrochemical systems for the accumulation of energy via the direct and inverse conversion of the electrical energy from RESs into the chemical energy of hydrogen with the storage of the latter is described. Some efficient technical solutions on the use of electrochemical hydrogen systems in power engineering for the storage of energy with a cyclic energy conversion efficiency of more than 40% are proposed. It is shown that the storage of energy in the form of hydrogen is environmentally safe and considerably surpasses traditional accumulator batteries by its capacitance characteristics, being especially topical in the prolonged absence of energy supply from RESs, e.g., under the conditions of polar night and breathless weather. To provide the required heat consumption of an object during the peak period, it is proposed to burn some hydrogen in a boiler house.

  18. Experimental screening of carbon-base materials for impact members in isotopic heat sources

    International Nuclear Information System (INIS)

    Bansal, G.K.; Duckworth, W.H.

    1976-11-01

    Fourteen C/C composites and three reentry-grade bulk graphites were evaluated experimentally to determine their applicability for impact member use in radioisotope heat sources. The composites included the following generic types: (1) 2-D cloth lay-ups; (2) 2-D and 3-D felts; (3) 3-D weaves; (4) 3-D pierced fabrics; (5) 7-D weave; and (6) coarse polar weave. Also included was the 2-D randomly wound, resin-impregnated C/C material presently used as the impact member in the MHW RTG and commonly designated ''GIS'' (an acronym for graphite impact shell). The various materials were evaluated as energy absorbing materials. None of the materials in these tests performed appreciably better than the GIS impact member material now used in the MHW heat source, HITCO Pyro Carb 814. Two cloth lay-up composites, HITCO's Pyro Carb 903 and Carborundum's Carbitex 700, were somewhat superior in performance, while the bulk graphites and felt-base composites ranked least effective as energy absorbers. All experimental data and other factors considered to date suggest that Pyro Carb 903 is the best prospect for a bifunctional heat shield and impact member. Its high density (1.80 g/cm 3 ) indicates potentially good ablation resistance to accompany its indicated good performance as an energy absorber

  19. 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...... and the covered demand of each heat source as well as required peak unit capacity. The results showed that heat pumps using different heat sources yield better performance than a heat pump based on a single one. The performance was influenced by the composition of the different heat sources. It was found that 78......% groundwater, 22% seawater and 0% air resulted in highest COP of 3.33 for the given heat demand. Furthermore, the implementation of rule based short term storage made peak units redundant. The variation in base load capacity showed that heat pumps utilizing the analyzed heat sources could perform very...

  20. Neutron generator for BNCT based on high current ECR ion source with gyrotron plasma heating.

    Science.gov (United States)

    Skalyga, V; Izotov, I; Golubev, S; Razin, S; Sidorov, A; Maslennikova, A; Volovecky, A; Kalvas, T; Koivisto, H; Tarvainen, O

    2015-12-01

    BNCT development nowadays is constrained by a progress in neutron sources design. Creation of a cheap and compact intense neutron source would significantly simplify trial treatments avoiding use of expensive and complicated nuclear reactors and accelerators. D-D or D-T neutron generator is one of alternative types of such sources for. A so-called high current quasi-gasdynamic ECR ion source with plasma heating by millimeter wave gyrotron radiation is suggested to be used in a scheme of D-D neutron generator in the present work. Ion source of that type was developed in the Institute of Applied Physics of Russian Academy of Sciences (Nizhny Novgorod, Russia). It can produce deuteron ion beams with current density up to 700-800 mA/cm(2). Generation of the neutron flux with density at the level of 7-8·10(10) s(-1) cm(-2) at the target surface could be obtained in case of TiD2 target bombardment with deuteron beam accelerated to 100 keV. Estimations show that it is enough for formation of epithermal neutron flux with density higher than 10(9) s(-1) cm(-2) suitable for BNCT. Important advantage of described approach is absence of Tritium in the scheme. First experiments performed in pulsed regime with 300 mA, 45 kV deuteron beam directed to D2O target demonstrated 10(9) s(-1) neutron flux. This value corresponds to theoretical estimations and proofs prospects of neutron generator development based on high current quasi-gasdynamic ECR ion source. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Solution to Two-Dimensional Steady Inverse Heat Transfer Problems with Interior Heat Source Based on the Conjugate Gradient Method

    Directory of Open Access Journals (Sweden)

    Shoubin Wang

    2017-01-01

    Full Text Available The compound variable inverse problem which comprises boundary temperature distribution and surface convective heat conduction coefficient of two-dimensional steady heat transfer system with inner heat source is studied in this paper applying the conjugate gradient method. The introduction of complex variable to solve the gradient matrix of the objective function obtains more precise inversion results. This paper applies boundary element method to solve the temperature calculation of discrete points in forward problems. The factors of measuring error and the number of measuring points zero error which impact the measurement result are discussed and compared with L-MM method in inverse problems. Instance calculation and analysis prove that the method applied in this paper still has good effectiveness and accuracy even if measurement error exists and the boundary measurement points’ number is reduced. The comparison indicates that the influence of error on the inversion solution can be minimized effectively using this method.

  2. New nuclear heat sources for district heating

    International Nuclear Information System (INIS)

    Lerouge, B.

    1975-01-01

    The means by which urban oil heating may be taken over by new energy sources, especially nuclear, are discussed. Several possibilities exist: pressurized water reactors for high powers, and low-temperature swimming-pool-type process-heat reactors for lower powers. Both these cases are discussed [fr

  3. Strong source heat transfer simulations based on a GalerKin/Gradient - least - squares method

    International Nuclear Information System (INIS)

    Franca, L.P.; Carmo, E.G.D. do.

    1989-05-01

    Heat conduction problems with temperature-dependent strong sources are modeled by an equation with a laplacian term, a linear term and a given source distribution term. When the linear-temperature-dependent source term is much larger than the laplacian term, we have a singular perturbation problem. In this case, boundary layers are formed to satisfy the Dirichlet boundary conditions. Although this is an elliptic equation, the standard Galerkin method solution is contaminated by spurious oscillations in the neighborhood of the boundary layers. Herein we employ a Galerkin/Gradient-least-squares method which eliminates all pathological phenomena of the Galerkin method. The method is constructed by adding to the Galerkin method a mesh-dependent term obtained by the least-squares form of the gradient of the Euler-Lagrange equation. Error estimates, numerical simulations in one-and multi-dimensions are given that attest the good stability and accuracy properties of the method [pt

  4. Crystallization Analysis and Control of Ammonia-Based Air Source Absorption Heat Pump in Cold Regions

    Directory of Open Access Journals (Sweden)

    Wei Wu

    2013-01-01

    Full Text Available Energy consumption of heating and domestic hot water is very high and will keep increasing. Air source absorption heat pump (ASAHP was proposed to overcome the problems of low energy efficiency and high air pollution existing in boiler systems, as well as the problem of bad performance under low ambient temperatures for electrical heat pumps. In order to investigate the crystallization possibility of ammonia-salt ASAHP, crystallization margin (evaluated by solution mass concentration at generating temperature ranging from 100 to 150°C, evaporating temperature from −30 to 10°C, and condensing temperature from 30 to 65°C are analyzed. To prevent the NH3–NaSCN solution from crystallizing, ASAHP integrated with pressure booster located between the evaporator and absorber is simulated. Analysis and comparisons show that NH3–NaSCN is easy to crystallize at relatively high generating temperature, low evaporating temperature, and low condensing temperature. But crystallization margin of NH3–LiNO3 can always stay above 5% for most conditions, keeping away from crystallization. Pressure booster can effectively avoid the crystallization problem that will take place in the NH3–NaSCN ASAHP system.

  5. Hot Hydrogen Heat Source Development

    Data.gov (United States)

    National Aeronautics and Space Administration — The purpose of this project is to develop a  hot hydrogen heat source that would produce  a high temperature hydrogen flow which would be comparable to that produced...

  6. International patent analysis of water source heat pump based on orbit database

    Science.gov (United States)

    Li, Na

    2018-02-01

    Using orbit database, this paper analysed the international patents of water source heat pump (WSHP) industry with patent analysis methods such as analysis of publication tendency, geographical distribution, technology leaders and top assignees. It is found that the beginning of the 21st century is a period of rapid growth of the patent application of WSHP. Germany and the United States had done researches and development of WSHP in an early time, but now Japan and China have become important countries of patent applications. China has been developing faster and faster in recent years, but the patents are concentrated in universities and urgent to be transferred. Through an objective analysis, this paper aims to provide appropriate decision references for the development of domestic WSHP industry.

  7. Biological effects of intracorporeal radioisotope heat sources

    International Nuclear Information System (INIS)

    Gillis, M.F.; Decker, J.R.; Karagianes, M.T.

    1976-01-01

    A surface heat flux of 0.04 watts/cm 2 from a retroperitoneal implant with healthy surface ingrowth of tissue prior to generation of heat is intolerable, producing gross tissue necrosis. Percutaneous cooling of hot implants during the post-operative healing period is a feasible technique, but our current plutonium heat source implant design has been proven of inadequate size and a new design is described. Rough calculations based on tissue conductivity and conductance values suggest that even with this larger device, added heat to proximate tissues may produce long-term changes even though the heat burden may be tolerable over relatively short periods

  8. Development of efficient air-cooling strategies for lithium-ion battery module based on empirical heat source model

    International Nuclear Information System (INIS)

    Wang, Tao; Tseng, K.J.; Zhao, Jiyun

    2015-01-01

    Thermal modeling is the key issue in thermal management of lithium-ion battery system, and cooling strategies need to be carefully investigated to guarantee the temperature of batteries in operation within a narrow optimal range as well as provide cost effective and energy saving solutions for cooling system. This article reviews and summarizes the past cooling methods especially forced air cooling and introduces an empirical heat source model which can be widely applied in the battery module/pack thermal modeling. In the development of empirical heat source model, three-dimensional computational fluid dynamics (CFD) method is employed, and thermal insulation experiments are conducted to provide the key parameters. A transient thermal model of 5 × 5 battery module with forced air cooling is then developed based on the empirical heat source model. Thermal behaviors of battery module under different air cooling conditions, discharge rates and ambient temperatures are characterized and summarized. Varies cooling strategies are simulated and compared in order to obtain an optimal cooling method. Besides, the battery fault conditions are predicted from transient simulation scenarios. The temperature distributions and variations during discharge process are quantitatively described, and it is found that the upper limit of ambient temperature for forced air cooling is 35 °C, and when ambient temperature is lower than 20 °C, forced air-cooling is not necessary. - Highlights: • An empirical heat source model is developed for battery thermal modeling. • Different air-cooling strategies on module thermal characteristics are investigated. • Impact of different discharge rates on module thermal responses are investigated. • Impact of ambient temperatures on module thermal behaviors are investigated. • Locations of maximum temperatures under different operation conditions are studied.

  9. Curing of a Bisphenol-E Based Cyanate Ester using Magnetic Nanoparticles as an Internal Heat Source through Induction Heating

    Science.gov (United States)

    2013-11-01

    reactions forming high-temperature thermosetting polymers and for innovative ways to process such polymers. 15. SUBJECT TERMS 16. SECURITY...reaction should allow for other reactions forming high-temperature thermosetting polymers and for innovative ways to process such polymers...generated by the particles in a polymer,18 1 µm nickel alloy (Nitinol) used to compare polymerizations with conventional or induction heating,19 or a

  10. General Purpose Heat Source Simulator

    Science.gov (United States)

    Emrich, Bill

    2008-01-01

    The General Purpose Heat Source (GPHS) simulator project is designed to replicate through the use of electrical heaters, the form, fit, and function of actual GPHS modules which generate heat through the radioactive decay of Pu238. The use of electrically heated modules rather than modules containing Pu238 facilitates the testing of spacecraft subsystems and systems without sacrificing the quantity and quality of the test data gathered. Previous GPHS activities are centered around developing robust heater designs with sizes and weights that closely matched those of actual Pu238 fueled GPHS blocks. These efforts were successful, although their maximum temperature capabilities were limited to around 850 C. New designs are being pursued which also replicate the sizes and weights of actual Pu238 fueled GPHS blocks but will allow operation up to 1100 C.

  11. A simulation-based analysis of variable flow pumping in ground source heat pump systems with different types of borehole heat exchangers: A case study

    International Nuclear Information System (INIS)

    Zarrella, Angelo; Emmi, Giuseppe; De Carli, Michele

    2017-01-01

    Highlights: • The work focuses on the variable flow in ground source heat pump systems. • The constant and variable speed circulation pumps in the ground loop are compared. • The constant temperature difference control across the heat pump is studied. • The variable flow affects the energy performance of the heat pump. • The constant temperature difference control offers an attractive energy saving. - Abstract: A simulation model of ground source heat pump systems has been used to investigate to what extent a variable flow of the heat-carrier fluid of the ground loop affects the energy efficiency of the entire system. The model contemporaneously considers the borehole heat exchangers, the heat pump, the building load, and the control strategies for the circulation pumps of the ground loop. A constant speed of the circulation pumps of the ground loop was compared with a variable flow controlled by means of a constant temperature difference across the heat pump on the ground side considering the load profile of an office building located in North Italy. The analysis was carried out for a single U-tube, double U-tube and coaxial pipe heat exchangers. The control strategies adopted to manage the flow rate of the heat-carrier fluid of the ground loop affect both the heat exchange rate of the borehole field and the heat pump’s long-term energy efficiency. The simulations show considerable differences in the system’s seasonal energy efficiency. The constant speed of the circulation pumps leads to the best results as far as the heat pump’s energy performance was concerned, but this advantage was lost because of the greater amount of electrical energy used by the circulation pumps; this, of course, affects the energy efficiency of the entire system. The optimal solution appears then to be a constant temperature difference in the heat-carrier fluid across the heat pump.

  12. A modified Gaussian model for the thermal plume from a ground-based heat source in a cross-wind

    International Nuclear Information System (INIS)

    Selander, W.N.; Barry, P.J.; Robertson, E.

    1990-06-01

    An array of propane burners operating at ground level in a cross-wind was used as a heat source to establish a blown-over thermal plume. A three-dimensional array of thermocouples was used to continuously measure the plume temperature downwind from the source. The resulting data were used to correlate the parameters of a modified Gaussian model for plume rise and dispersion with source strength, wind speed, and atmospheric dispersion parameters

  13. Nuclear heat sources for cryogenic refrigerator applications

    International Nuclear Information System (INIS)

    Raab, B.; Schock, A.; King, W.G.; Kline, T.; Russo, F.A.

    1975-01-01

    Spacecraft cryogenic refrigerators require thermal inputs on the order of 1000 W. First, the characteristics of solar-electric and radioisotope heat source systems for supplying this thermal input are compared. Then the design of a 238 Pu heat source for this application is described, and equipment for shipping and handling the heat source is discussed. (LCL)

  14. Member for conducting excess heat away from heat sources

    International Nuclear Information System (INIS)

    Cooke-Yarborough, E.H.

    1975-01-01

    Should a radioisotope-powered engine (e.g., a Stirling cycle engine for generating electricity) stop working for any reason, the radioisotope heat source will continue to generate heat. This will result in a rise in temperature which may cause overheating of and possible damage to the engine as well as to the heat source itself. The invention provides a support/location member for conducting excess heat from the heat source and which, in normal operation of the engine, will impede the conduction of heat away from the heat source and so reduce thermal losses. The member is of elongated form and comprises a stack of heat-conductive slugs disposed in a tube and in interspaced relationship along the axis of the tube. The tube supports the slugs in axial alignment. Means are provided for attaching an end one of the slugs to the heat source and means operable on overheating of said end one of the slugs are also provided whereby the slugs are able to move into heat-conducting contact with each other so as to conduct the excess heat away from said heat source. The slugs may be brazed to the tube whereby progressive overheating of the slugs along the stack results in an overheated slug being freed from attachment to the tube so as to allow the overheated slug to move along the stack and engage the next slug in line in heat-conducting contact. (U.S.)

  15. Hybrid district heating system with heat supply from nuclear source

    International Nuclear Information System (INIS)

    Havelka, Z.; Petrovsky, I.

    1987-01-01

    Several designs are described of heat supply from large remote power sources (e.g., WWER-1000 nuclear power plants with a 1000 MW turbine) to localities where mainly steam distribution networks have been built but only some or none networks for hot water distribution. The benefits of the designs stem from the fact that they do not require the conversion of the local steam distribution system to a hot water system. They are based on heat supply from the nuclear power plant to the consumer area in hot water of a temperature of 150 degC to 200 degC. Part of the hot water heat will be used for the production of low-pressure steam which will be compressed using heat pumps (steam compressors) to achieve the desired steam distribution network specifications. Water of lower temperature can be used in the hot water network. The hot water feeder forms an automatic pressure safety barrier in heat supply of heating or technological steam from a nuclear installation. (Z.M.). 5 figs., 9 refs

  16. Predicting performance of a ground-source heat pump system using fuzzy weighted pre-processing-based ANFIS

    Energy Technology Data Exchange (ETDEWEB)

    Esen, Hikmet; Esen, Mehmet [Department of Mechanical Education, Faculty of Technical Education, Firat University, 23119 Elazig (Turkey); Inalli, Mustafa [Department of Mechanical Engineering, Faculty of Engineering, Firat University, 23279 Elazig (Turkey); Sengur, Abdulkadir [Department of Electronic and Computer Science, Faculty of Technical Education, Firat University, 23119 Elazig (Turkey)

    2008-12-15

    The goal of this work is to predict the daily performance (COP) of a ground-source heat pump (GSHP) system with the minimum data set based on an adaptive neuro-fuzzy inference system (ANFIS) with a fuzzy weighted pre-processing (FWP) method. To evaluate the effectiveness of our proposal (FWP-ANFIS), a computer simulation is developed on MATLAB environment. The comparison of the proposed hybridized system's results with the standard ANFIS results is carried out and the results are given in the tables. The efficiency of the proposed method was demonstrated by using the 3-fold cross-validation test. The statistical methods, such as the root-mean squared (RMS), the coefficient of multiple determinations (R{sup 2}) and the coefficient of variation (cov), are given to compare the predicted and actual values for model validation. The average R{sup 2} values is 0.9998, the average RMS value is 0.0272 and the average cov value is 0.7733, which can be considered as very promising. The data set for the COP of GSHP system available included 38 data patterns. The simulation results show that the FWP-based ANFIS can be used in an alternative way in these systems. The prediction results of the proposed structure were much better than the standard ANFIS results. Therefore, instead of limited experimental data found in the literature, faster and simpler solutions are obtained using hybridized structures such as FWP-based ANFIS. (author)

  17. Comparison of swimming pools alternative passive and active heating systems based on renewable energy sources in Southern Europe

    International Nuclear Information System (INIS)

    Katsaprakakis, Dimitris Al.

    2015-01-01

    This article examines different passive and active heating systems for swimming pools. The passive systems introduced in this article are: * The swimming pools' enclosure. * The placement of floating insulating covers on the pools' surfaces whenever they are not used. The examined active systems in this article are: * A biomass heater. * A biomass heater and solar collectors combi-system. * Vertical geothermal heat exchangers (GHE) co-operating with geothermal heat pumps (GHP). The methodology employed for the introduced systems' evaluation is the arithmetic computational simulation of the swimming pools' annual heating, using annual time series of averaged hourly values for the available solar radiation and the calculated pools' thermal power demand (heating loads). The dimensioning of the active systems aims at the maximisation of the heating production from R.E.S. (renewable energy sources). and the optimisation of the corresponding investments' economic indexes. The examined systems are evaluated technically and economically versus fundamental criteria. It is proved that significant reduction of the heating loads is achieved with the introduced passive systems. The reduced swimming pools' heating loads can be successfully covered by the proposed R.E.S. active systems. The fossil fuels consumption is eliminated. The corresponding investments' payback periods can be lower than 5 years. - Highlights: • The passive solar systems reduce the swimming pools heating loads more than 90%. • The examined active heating system exhibit payback periods lower than 3.5 years. • The energy saving is maximised with a biomass heater – solar collectors system. • Single biomass heaters exhibits the shortest payback period. • GHE–GHP can be used in cases of low solar radiation and lack of biomass fuels

  18. Thulium heat sources for space power applications

    International Nuclear Information System (INIS)

    Alderman, C.J.

    1992-05-01

    Reliable power supplies for use in transportation and remote systems will be an important part of space exploration terrestrial activities. A potential power source is available in the rare earth metal, thulium. Fuel sources can be produced by activating Tm-169 targets in the space station reactor. The resulting Tm-170 heat sources can be used in thermoelectric generators to power instrumentation and telecommunications located at remote sites such as weather stations. As the heat source in a dynamic Sterling or Brayton cycle system, the heat source can provide a lightweight power source for rovers or other terrestrial transportation systems

  19. Effects of Symmetrically Arranged Heat Sources on the Heat Release Performance of Extruded-Type Heat Sinks

    Energy Technology Data Exchange (ETDEWEB)

    Ku, Min Ye [Chonbuk National Univ., Chonju (Korea, Republic of)

    2016-02-15

    In this study we investigated the effects of symmetrically arranged heat sources on the heat release performances of extruded-type heat sinks through experiments and thermal fluid simulations. Also, based on the results we suggested a high-efficiency and cost-effective heat sink for a solar inverter cooling system. In this parametric study, the temperatures between heaters on the base plate and the heat release rates were investigated with respect to the arrangements of heat sources and amounts of heat input. Based on the results we believe that the use of both sides of the heat sink is the preferred method for releasing the heat from the heat source to the ambient environment rather than the use of a single side of the heat sink. Also from the results, it is believed that the symmetric arrangement of the heat sources is recommended to achieve a higher rate of heat transfer. From the results of the thermal fluid simulation, it was possible to confirm the qualitative agreement with the experimental results. Finally, quantitative comparison with respect to mass flow rates, heat inputs, and arrangements of the heat source was also performed.

  20. A synthetic layout optimization of discrete heat sources flush mounted on a laminar flow cooled flat plate based on the constructal law

    International Nuclear Information System (INIS)

    Shi, Zhongyuan; Dong, Tao

    2015-01-01

    Highlights: • A constructal thermohydraulic optimization was carried out. • The effect of manufacturing limit on the Pareto solution set was discussed. • The suitable constraints may differ from those on a quasi-continuous basis. - Abstract: A synthetic optimization is presented for the Pareto layouts of discrete heat sources (with uniform heat flux) flush mounted on a flat plate over which laminar flow serves for cooling purpose. The peak temperatures and the flow drag loss are minimizing simultaneously provided that the total heat dissipation rate and the plate length are held constant. The impact of the manufacturing limit, i.e. the minimum length of the heated or the adiabatic patch, on the optimum layout is discussed. The results in general comply with analytical deduction based on the constructal theory. However in a finite length scenario, geometric constraints on the adiabatic spacing differ from that fits the situation in which maximum heat transfer performance alone is to be achieved.

  1. Diffusion of heat from a finite, rectangular, plane heat source

    International Nuclear Information System (INIS)

    Ferreri, J.C.; Caballero, C.H.

    1985-01-01

    Non-dimensional results for the temperature field originating in a rectangular, finite, plane heat source with infinitesimal thickness are introduced. The source decays in time, zero decay being a particular case. Results are useful for obtaining an aproximation of the maximum temperature of a system holding an internal heat source. The range selected for the parameters is specially useful in the case of a nuclear waste repository. The application to the case of mass diffussion arises from analogy. (Author) [es

  2. Mapping of potential heat sources for heat pumps for district heating in Denmark

    International Nuclear Information System (INIS)

    Lund, Rasmus; Persson, Urban

    2016-01-01

    The ambitious policy in Denmark on having a 100% renewable energy supply in 2050 requires radical changes to the energy systems to avoid an extensive and unsustainable use of biomass resources. Currently, wind power is being expanded and the increasing supply of electricity is slowly pushing the CHP (combined heat and power) plants out of operation, reducing the energy efficiency of the DH (district heating) supply. Here, large heat pumps for district heating is a frequently mentioned solution as a flexible demand for electricity and an energy efficient heat producer. The idea is to make heat pump use a low temperature waste or ambient heat source, but it has so far been very unclear which heat sources are actually available for this purpose. In this study eight categories of heat sources are analysed for the case of Denmark and included in a detailed spatial analysis where the identified heat sources are put in relation to the district heating areas and the corresponding demands. The analysis shows that potential heat sources are present near almost all district heating areas and that sea water most likely will have to play a substantial role as a heat source in future energy systems in Denmark. - Highlights: • The availability of heat sources for heat pumps in Denmark are mapped and quantified. • A novel methodology for assessment of low temperature industrial excess heat is presented. • There are heat sources available for 99% of district heating networks in Denmark. • The concentration of heat sources is generally bigger around bigger cities than smaller. • Ambient temperature heat sources will be more needed in district heating of big cities.

  3. Design of serially connected district heating heat pumps utilising a geothermal heat source

    DEFF Research Database (Denmark)

    Jensen, Jonas Kjær; Ommen, Torben Schmidt; Markussen, Wiebke Brix

    2017-01-01

    The design of two heat pumps (HP), connected in series, was investigated for operation in the district heating (DH) network of the Greater Copenhagen area, Denmark. The installation was dimensioned to supply 7.2 MW of heat at a temperature of 85 °C. The heat pumps utilise a geothermal heat source...

  4. Advanced radioisotope heat source for Stirling Engines

    International Nuclear Information System (INIS)

    Dobry, T.J.; Walberg, G.

    2001-01-01

    The heat exchanger on a Stirling Engine requires a thermal energy transfer from a heat source to the engine through a very limited area on the heater head circumference. Designing an effective means to assure maximum transfer efficiency is challenging. A single General Purpose Heat Source (GPHS), which has been qualified for space operations, would satisfy thermal requirements for a single Stirling Engine that would produce 55 electrical watts. However, it is not efficient to transfer its thermal energy to the engine heat exchanger from its rectangular geometry. This paper describes a conceptual design of a heat source to improve energy transfer for Stirling Engines that may be deployed to power instrumentation on space missions

  5. Optimal Ground Source Heat Pump System Design

    Energy Technology Data Exchange (ETDEWEB)

    Ozbek, Metin [Environ Holdings Inc., Princeton, NJ (United States); Yavuzturk, Cy [Univ. of Hartford, West Hartford, CT (United States); Pinder, George [Univ. of Vermont, Burlington, VT (United States)

    2015-04-01

    Despite the facts that GSHPs first gained popularity as early as the 1940’s and they can achieve 30 to 60 percent in energy savings and carbon emission reductions relative to conventional HVAC systems, the use of geothermal energy in the U.S. has been less than 1 percent of the total energy consumption. The key barriers preventing this technically-mature technology from reaching its full commercial potential have been its high installation cost and limited consumer knowledge and trust in GSHP systems to deliver the technology in a cost-effective manner in the market place. Led by ENVIRON, with support from University Hartford and University of Vermont, the team developed and tested a software-based a decision making tool (‘OptGSHP’) for the least-cost design of ground-source heat pump (‘GSHP’) systems. OptGSHP combines state of the art optimization algorithms with GSHP-specific HVAC and groundwater flow and heat transport simulation. The particular strength of OptGSHP is in integrating heat transport due to groundwater flow into the design, which most of the GSHP designs do not get credit for and therefore are overdesigned.

  6. Lunar Base Heat Pump

    Science.gov (United States)

    Walker, D.; Fischbach, D.; Tetreault, R.

    1996-01-01

    The objective of this project was to investigate the feasibility of constructing a heat pump suitable for use as a heat rejection device in applications such as a lunar base. In this situation, direct heat rejection through the use of radiators is not possible at a temperature suitable for lde support systems. Initial analysis of a heat pump of this type called for a temperature lift of approximately 378 deg. K, which is considerably higher than is commonly called for in HVAC and refrigeration applications where heat pumps are most often employed. Also because of the variation of the rejection temperature (from 100 to 381 deg. K), extreme flexibility in the configuration and operation of the heat pump is required. A three-stage compression cycle using a refrigerant such as CFC-11 or HCFC-123 was formulated with operation possible with one, two or three stages of compression. Also, to meet the redundancy requirements, compression was divided up over multiple compressors in each stage. A control scheme was devised that allowed these multiple compressors to be operated as required so that the heat pump could perform with variable heat loads and rejection conditions. A prototype heat pump was designed and constructed to investigate the key elements of the high-lift heat pump concept. Control software was written and implemented in the prototype to allow fully automatic operation. The heat pump was capable of operation over a wide range of rejection temperatures and cooling loads, while maintaining cooling water temperature well within the required specification of 40 deg. C +/- 1.7 deg. C. This performance was verified through testing.

  7. HEAT PUMP USING SUBSOIL WATERS AS LOW TEMPERATURE HEAT SOURCE

    Directory of Open Access Journals (Sweden)

    Denysova Alla

    2015-08-01

    Full Text Available One of the basic directions of perfection of heat supply systems is the tendency of transition to the low-temperature heating systems based on application of heat pump installations. We consider heat supply system with heat pump installations using subsoil waters. Numerical simulation of thermal processes in the elements of a single-stage and double-stage heat pump systems has been worked out. Values of depths of wells and their quantity, necessary for effective operation of the offered installations, and values of capacity of electric water pumps for subsoil waters unit are calculated. Capacity of compressor electric drive and coefficient of performance of heat pump for the conditions of the city of Odessa are presented.

  8. Comparative Evaluation of Different Computational Models for Performance of Air Source Heat Pumps Based on Real World Data

    NARCIS (Netherlands)

    Tabatabaei, Seyed Amin; Treur, Jan; Waumans, Erik

    2015-01-01

    To reduce energy usage and CO2 emission due to heating, heat pumps have turned out a good option. For example, to obtain a net zero house, often a combination of solar panels and a heat pump is used. A computational model of the performance of a heat pump provides a useful tool for prediction and

  9. Hoosac tunnel geothermal heat source. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1982-06-10

    The Hoosac Rail Tunnel has been analyzed as a central element in a district heating system for the City of North Adams. The tunnel has been viewed as a collector of the earth's geothermal heat and a seasonal heat storage facility with heat piped to the tunnel in summer from existing facilities at a distance. Heated fluid would be transported in winter from the tunnel to users who would boost the temperature with individual heat pumps. It was concluded the tunnel is a poor source of geothermal heat. The maximum extractable energy is only 2200 million BTU (20000 gallons of oil) at 58/sup 0/F. The tunnel is a poor heat storage facility. The rock conductivity is so high that 75% of the heat injected would escape into the mountain before it could be recaptured for use. A low temperature system, with individual heat pumps for temperature boost could be economically attractive if a low cost fuel (byproduct, solid waste, cogeneration) or a cost effective seasonal heat storage were available.

  10. Characterization and modeling of the heat source

    Energy Technology Data Exchange (ETDEWEB)

    Glickstein, S.S.; Friedman, E.

    1993-10-01

    A description of the input energy source is basic to any numerical modeling formulation designed to predict the outcome of the welding process. The source is fundamental and unique to each joining process. The resultant output of any numerical model will be affected by the initial description of both the magnitude and distribution of the input energy of the heat source. Thus, calculated weld shape, residual stresses, weld distortion, cooling rates, metallurgical structure, material changes due to excessive temperatures and potential weld defects are all influenced by the initial characterization of the heat source. Understandings of both the physics and the mathematical formulation of these sources are essential for describing the input energy distribution. This section provides a brief review of the physical phenomena that influence the input energy distributions and discusses several different models of heat sources that have been used in simulating arc welding, high energy density welding and resistance welding processes. Both simplified and detailed models of the heat source are discussed.

  11. Geothermal source heat pump performance for a greenhouse heating system: an experimental study

    Directory of Open Access Journals (Sweden)

    Alexandros Sotirios Anifantis

    2016-09-01

    Full Text Available Greenhouses play a significant function in the modern agriculture economy even if require great amount of energy for heating systems. An interesting solution to alleviate the energy costs and environmental problems may be represented by the use of geothermal energy. The aim of this paper, based on measured experimental data, such as the inside greenhouse temperature and the heat pump performance (input and output temperatures of the working fluid, electric consumption, was the evaluation of the suitability of low enthalpy geothermal heat sources for agricultural needs such as greenhouses heating. The study was carried out at the experimental farm of the University of Bari, where a greenhouse was arranged with a heating system connected to a ground-source heat pump (GSHP, which had to cover the thermal energy request. The experimental results of this survey highlight the capability of the geothermal heat source to ensue thermal conditions suitable for cultivation in greenhouses even if the compressor inside the heat pump have operated continuously in a fluctuating state without ever reaching the steady condition. Probably, to increase the performance of the heat pump and then its coefficient of performance within GSHP systems for heating greenhouses, it is important to analyse and maximise the power conductivity of the greenhouse heating system, before to design an expensive borehole ground exchanger. Nevertheless, according to the experimental data obtained, the GSHP systems are effective, efficient and environmental friendly and may be useful to supply the heating energy demand of greenhouses.

  12. Nuclear heat source component design considerations for HTGR process heat reactor plant concept

    International Nuclear Information System (INIS)

    McDonald, C.F.; Kapich, D.; King, J.H.; Venkatesh, M.C.

    1982-05-01

    The coupling of a high-temperature gas-cooled reactor (HTGR) and a chemical process facility has the potential for long-term synthetic fuel production (i.e., oil, gasoline, aviation fuel, hydrogen, etc) using coal as the carbon source. Studies are in progress to exploit the high-temperature capability of an advanced HTGR variant for nuclear process heat. The process heat plant discussed in this paper has a 1170-MW(t) reactor as the heat source and the concept is based on indirect reforming, i.e., the high-temperature nuclear thermal energy is transported [via an intermediate heat exchanger (IHX)] to the externally located process plant by a secondary helium transport loop. Emphasis is placed on design considerations for the major nuclear heat source (NHS) components, and discussions are presented for the reactor core, prestressed concrete reactor vessel (PCRV), rotating machinery, and heat exchangers

  13. Heat source model for welding process

    International Nuclear Information System (INIS)

    Doan, D.D.

    2006-10-01

    One of the major industrial stakes of the welding simulation relates to the control of mechanical effects of the process (residual stress, distortions, fatigue strength... ). These effects are directly dependent on the temperature evolutions imposed during the welding process. To model this thermal loading, an original method is proposed instead of the usual methods like equivalent heat source approach or multi-physical approach. This method is based on the estimation of the weld pool shape together with the heat flux crossing the liquid/solid interface, from experimental data measured in the solid part. Its originality consists in solving an inverse Stefan problem specific to the welding process, and it is shown how to estimate the parameters of the weld pool shape. To solve the heat transfer problem, the interface liquid/solid is modeled by a Bezier curve ( 2-D) or a Bezier surface (3-D). This approach is well adapted to a wide diversity of weld pool shapes met for the majority of the current welding processes (TIG, MlG-MAG, Laser, FE, Hybrid). The number of parameters to be estimated is weak enough, according to the cases considered from 2 to 5 in 20 and 7 to 16 in 3D. A sensitivity study leads to specify the location of the sensors, their number and the set of measurements required to a good estimate. The application of the method on test results of welding TIG on thin stainless steel sheets in emerging and not emerging configurations, shows that only one measurement point is enough to estimate the various weld pool shapes in 20, and two points in 3D, whatever the penetration is full or not. In the last part of the work, a methodology is developed for the transient analysis. It is based on the Duvaut's transformation which overpasses the discontinuity of the liquid metal interface and therefore gives a continuous variable for the all spatial domain. Moreover, it allows to work on a fixed mesh grid and the new inverse problem is equivalent to identify a source

  14. Air-source heat pump carbon footprints: HFC impacts and comparison to other heat sources

    International Nuclear Information System (INIS)

    Johnson, Eric P.

    2011-01-01

    European governments see that heat pumps could reduce carbon emissions in space- and hot-water heating. EU's Renewable Energy Directive designates heat pumps as renewable - eligible for various subsidies - if their carbon footprints are below an implied, average threshold. This threshold omits carbon generated by manufacture and emission of a heat-pump's fluorocarbon refrigerant. It also omits the footprint of the heat pump's hardware. To see if these omissions are significant, this study calculated carbon footprints of representative, residential heat pumps in the UK. Three findings emerged. First, in relation to power generation, which accounts for most of a heat-pump's greenhouse-gas emissions, fluorocarbons add another 20% to the footprint. Second, at UK efficiencies a heat-pump footprint (in kg CO 2 e emitted per kWh delivered) is comparable or higher than footprints of gaseous fuels used in heating. It is lower than the footprint of heating oil and far lower than the footprints of solid fuels. Third, production and disposal of a heat pump's hardware is relatively insignificant, accounting for only 2-3% of the overall heat-pump footprint. Sensitivities to the results were assessed: key factors are footprint of electricity generation, F-gas composition and leak rates and type of wall construction. - Research highlights: → Refrigerant emissions add 20% to a UK air-source heat pump's carbon footprint. → This contribution is so far ignored by regulations. → UK heat pump footprints are comparable to those of gaseous fuels.

  15. Heat transfer from the moving heat source of arbitrary shape

    International Nuclear Information System (INIS)

    Fomin, Sergei A.

    2000-01-01

    The present research is related to contact melting by a moving heat source of arbitrary shape. Heat conduction in the melting material is governed by 3D differential equation, where the thermal conductivity of the surrounding material is assumed to be strongly temperature dependent. By using the Green's formula, the boundary-value problem is converted to the boundary integral equation. This non-linear equation is solved numerically by interactions utilizing the boundary element method. Different shapes of heat sources are investigated. Since the obtained integral equation is the Fredholm type equation of the first kind and belongs to the family of so-called ill-posed problems, therefore, supplementary computations, that verify the stability of numerical algorithm, are provided. For the special cases associated with thermodrilling technology, some analytical estimations and solutions are obtained. Particularly, if the melting velocity is high (Pe>10), asymptotic solutions are found. In this case the integral equation is significantly reduced, that simplifies the computations. Numerical results are in good agreement with the closed-form solutions available for the elliptical shape of a solid-liquid interface. (author)

  16. Prediction of temperature and HAZ in thermal-based processes with Gaussian heat source by a hybrid GA-ANN model

    Science.gov (United States)

    Fazli Shahri, Hamid Reza; Mahdavinejad, Ramezanali

    2018-02-01

    Thermal-based processes with Gaussian heat source often produce excessive temperature which can impose thermally-affected layers in specimens. Therefore, the temperature distribution and Heat Affected Zone (HAZ) of materials are two critical factors which are influenced by different process parameters. Measurement of the HAZ thickness and temperature distribution within the processes are not only difficult but also expensive. This research aims at finding a valuable knowledge on these factors by prediction of the process through a novel combinatory model. In this study, an integrated Artificial Neural Network (ANN) and genetic algorithm (GA) was used to predict the HAZ and temperature distribution of the specimens. To end this, a series of full factorial design of experiments were conducted by applying a Gaussian heat flux on Ti-6Al-4 V at first, then the temperature of the specimen was measured by Infrared thermography. The HAZ width of each sample was investigated through measuring the microhardness. Secondly, the experimental data was used to create a GA-ANN model. The efficiency of GA in design and optimization of the architecture of ANN was investigated. The GA was used to determine the optimal number of neurons in hidden layer, learning rate and momentum coefficient of both output and hidden layers of ANN. Finally, the reliability of models was assessed according to the experimental results and statistical indicators. The results demonstrated that the combinatory model predicted the HAZ and temperature more effective than a trial-and-error ANN model.

  17. Is the Korean public willing to pay for a decentralized generation source? The case of natural gas-based combined heat and power

    International Nuclear Information System (INIS)

    Kim, Hyo-Jin; Lim, Seul-Ye; Yoo, Seung-Hoon

    2017-01-01

    Natural gas (NG)-based combined heat and power (CHP) plants can be installed near electricity-consuming areas and do not require large-scale and long-distance power transmission facilities. This paper attempts to assess the public's additional willingness to pay (WTP) for substituting consumption of a unit of electricity generated from nuclear power plant, currently a dominant power generation source in Korea, with that produced from NG-based CHP plant in terms of decentralized generation using the contingent valuation (CV) method. To this end, a CV survey of 1,000 households was implemented. The results show that the mean additional WTP for substituting nuclear power plant by NG-based CHP plant is estimated to be KRW 55.3 (USD 0.047) per kWh of electricity, which is statistically significant at the 1% level. This value amounts to 44.7% of the average price for electricity, KRW 123.69 (USD 0.106) in 2015, which implies that the public are ready to shoulder a significant financial burden to achieve the substitution. Moreover, the value can be interpreted as an external cost of nuclear power generation relative to NG-based CHP generation, or as an external benefit of NG-based CHP generation relative to nuclear power generation with a view to decentralized generation. - Highlights: • Combined heat and power (CHP) is a representative decentralized generation source. • Nuclear power requires large-scale and long-distance power transmission facilities. • We assess people's additional willingness to pay (WTP) for CHP over nuclear power. • We conduct a contingent valuation survey of 1,000 households in Korea. • The mean additional WTP amounts to 44.2% of the average price for electricity.

  18. Nuclear heat source component design considerations for HTGR process heat reactor plant concept

    International Nuclear Information System (INIS)

    McDonald, C.F.; Kapich, D.; King, J.H.; Venkatesh, M.C.

    1982-01-01

    Using alternate energy sources abundant in the U.S.A. to help curb foreign oil imports is vitally important from both national security and economic standpoints. Perhaps the most forwardlooking opportunity to realize national energy goals involves the integrated use of two energy sources that have an established technology base in the U.S.A., namely nuclear energy and coal. The coupling of a high-temperature gas-cooled reactor (HTGR) and a chemical process facility has the potential for long-term synthetic fuel production (i.e., oil, gasoline, aviation fuel, hydrogen, etc.) using coal as the carbon source. Studies are in progress to exploit the high-temperature capability of an advanced HTGR variant for nuclear process heat. The process heat plant discussed in this paper has a 1170-MW(t) reactor as the heat source and the concept is based on indirect reforming, i.e., the high-temperature nuclear thermal energy is transported (via an intermediate heat exchanger (IHX)) to the externally located process plant by a secondary helium transport loop. Emphasis is placed on design considerations for the major nuclear heat source (NHS) components, and discussions are presented for the reactor core, prestressed concrete reactor vessel (PCRV), rotating machinery, and heat exchangers

  19. Ground Source Heat Supply in Moscow Oblast: Temperature Potential and Sustainable Depth of Heat Wells

    Science.gov (United States)

    Vasil'ev, G. P.; Gornov, V. F.; Dmitriev, A. N.; Kolesova, M. V.; Yurchenko, V. A.

    2018-01-01

    The paper is devoted to a problem of increasing the efficiency of low-potential geothermal heat in heat pump systems of residential buildings the Moscow oblast of Russia, including Moscow. Estimates of a natural geothermal potential in the Moscow oblast (based on climatological data for the period from 1982 to 2011) are presented and a "Typical climatic year of natural soil temperature variations for the geoclimatic conditions of the Moscow oblast, including the city of Moscow" is proposed. Numerical simulation of the influence of geothermal energy potential and the depth of heat wells on the efficiency of ground source heat pump systems for the heat supply of residential buildings is carried out. Analysis of the numerical simulation showed that the operation of a heat pump system in a house heating mode under the geoclimatic conditions of the Moscow oblast leads to a temperature drop of the heat-exchange medium circulating through heat wells to 5-6°C by the end of the first 10 years of operation, and the process stabilizes by the 15th year of operation, and further changes in the heat-exchange medium temperature do not any longer significantly affect the temperature of the heat-exchange medium in the heat well. In this case, the exact dependence of the heat-exchange medium temperature drop on the depth is not revealed. Data on the economically expedient heat well depth for the conditions of the Moscow oblast ensuring a net present value for the whole residential building life cycle are presented. It is found that the heat well depth of 60 m can be considered as an endpoint for the Moscow oblast, and a further heat well deepening is economically impractical.

  20. Improvements in or relating to devices for conducting excess heat away from heat sources

    International Nuclear Information System (INIS)

    Cooke-Yarborough, E.H.

    1976-01-01

    Reference is made to radioisotope powered heat engines. Should such an engine stop working for any reason the radioisotope heat source will continue to generate heat, and this may cause overheating and possible damage to the engine as well as the heat source. A device is described for conducting excess heat from the heat source to a heat sink but which in normal operation of the engine will impede heat conduction and so reduce thermal losses. The device may be used to support and/or locate the heat source. Constructional and operational details are given. (U.K.)

  1. Utilization of low-temperature heat sources for heat and power production

    DEFF Research Database (Denmark)

    Haglind, Fredrik; Elmegaard, Brian

    2014-01-01

    Low-temperature heat sources are available in many applications, ranging from waste heat from marine diesel engines, industries and refrigeration plants to biomass, geothermal and solar heat sources. There is a great potential for enhancing the utilization of these heat sources by novel...

  2. Cost of heat from a seasonal source

    Science.gov (United States)

    Reilly, R. W.; Brown, D. R.; Huber, H. D.

    Results are reported of an investigation to estimate the cost of aquifer thermal energy storage (ATES) from a seasonal heat source. The cost of supplying energy (hot water) from an ATES system is estimated. Three types of loads are investigated: point demands, residential developments, and a multidistrict city. Several technical and economic factors are found to control the economic performance of an ATES system. Costs are found to be prohibitive for systems of small size, long transmission distances, and employing expensive purchased thermal energy. ATES is found to be cost-competitive with oil-fired and electric hot water delivery systems under a broad range of potential situations.

  3. Soil temperature distribution around a U-tube heat exchanger in a multi-function ground source heat pump system

    International Nuclear Information System (INIS)

    Li Shuhong; Yang Weihua; Zhang Xiaosong

    2009-01-01

    The imbalance of heat extracted from the earth by the underground heat exchangers in winter and ejected into it in summer is expected to affect the long term performance of conventional ground source heat pump (GSHP) in territories with a cold winter and a warm summer such as the middle and downstream areas of the Yangtze River in China. This paper presents a new multi-function ground source heat pump (MFGSHP) system which supplies hot water as well as space cooling/heating to mitigate the soil imbalance of the extracted and ejected heat by a ground source heat pump system. The heat transfer characteristic is studied and the soil temperature around the underground heat exchangers are simulated under a typical climatic condition of the Yangtze River. A three-dimensional model was constructed with the commercial computational fluid dynamics software FLUENT based on the inner heat source theory. Temperature distribution and variation trend of a tube cluster of the underground heat exchanger are simulated for the long term performance. The results show that the soil temperature around the underground tube keeps increasing due to the surplus heat ejected into the earth in summer, which deteriorates the system performance and may lead to the eventual system deterioration. The simulation shows that MFGSHP can effectively alleviate the temperature rise by balancing the heat ejected to/extracted from underground by the conventional ground source heat pump system. The new system also improves the energy efficiency.

  4. Analysis of the orderly distribution of oil and gas fields in China based on the theory of co-control of source and heat

    Directory of Open Access Journals (Sweden)

    Gongcheng Zhang

    2015-01-01

    Full Text Available Taking a hydrocarbon zone or a basin group as a unit, this paper analyzed the vertical hydrocarbon generation regularity of onshore and offshore oil and gas fields in China, based on the theory of co-control of source and heat. The results demonstrated that the hydrocarbon generation modes of oil and gas fields in China are orderly. First, the hydrocarbon zones in southeastern China offshore area, including the East and South China Sea basins, are dominated by single hydrocarbon generation mode, which displays as either single oil generation in the near shore or single gas generation in the offshore controlled by both source and heat. Second, the eastern hydrocarbon zones, including the Bohai Bay, Songliao and Jianghan basins and the North and South Yellow Sea basins, are dominated by a two-layer hydrocarbon generation mode, which performs as “upper oil and lower gas”. Third, the central hydrocarbon zones, including the Ordos, Sichuan and Chuxiong basins, are also dominated by the “upper oil and lower gas” two-layer hydrocarbon generation mode. In the Ordos Basin, gas is mainly generated in the Triassic, and oil is predominantly generated in the Paleozoic. In the Sichuan Basin, oil was discovered in the Jurassic, and gas was mostly discovered in the Sinian and Triassic. Fourth, the western hydrocarbon zones are dominated by a “sandwich” multi-layer mode, such as the Junggar, Tarim, Qaidam basins. In summary, the theory of co-control of source and heat will be widely applied to oil and gas exploration all over China. Oil targets should be focused on the near shore areas in the southeastern China sea, the upper strata in the eastern and middle hydrocarbon zones, and the Ordovician, Permian and Paleogene strata in the western hydrocarbon zone, while gas targets should be focused on the off-shore areas in the southeastern China sea, the Cambrian, Carboniferous, Jurassic, and Quaternary strata in the western hydrocarbon zone. A pattern of

  5. 21 CFR 872.6475 - Heat source for bleaching teeth.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Heat source for bleaching teeth. 872.6475 Section... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6475 Heat source for bleaching teeth. (a) Identification. A heat source for bleaching teeth is an AC-powered device that consists of a...

  6. Upscaling a district heating system based on biogas cogeneration and heat pumps

    NARCIS (Netherlands)

    van Leeuwen, Richard Pieter; Fink, J.; Smit, Gerardus Johannes Maria; de Wit, Jan B.

    2015-01-01

    The energy supply of the Meppel district Nieuwveense landen is based on biogas cogeneration, district heating, and ground source heat pumps. A centrally located combined heat and power engine (CHP) converts biogas from the municipal wastewater treatment facility into electricity for heat pumps and

  7. Ground Source Heat Pump in Heating System with Electronics Monitoring

    Directory of Open Access Journals (Sweden)

    NEAMŢU Ovidiu

    2013-10-01

    Full Text Available The monitoring system is implemented for a ground coupled heat pump in heating/ system. The borehole heat exchangers – which are 150 m long - are filled with a mixture of water and ethilene glycol calledbrine. Metering and monitoring energy consumption is achieved for: heat pump, circulation pumps, additional electrical heating, hot air ventilation systems, control systems with sensors: analog and smart sensors. Instantaneous values are stored in a local computer.

  8. Radioisotopes for heat-source applications

    International Nuclear Information System (INIS)

    Hoisington, J.E.

    1982-01-01

    Potential DOD requirements for noninterruptable power sources could total 1 MW thermal by FY 1990. Of the three isotopes considered, ( 90 Sr, 147 Pm, 238 Pu) 90 Sr is the only one available in sufficient amounts to meet this requirement. To meet the DOD FY 1990 requirements, it would be necessary to undertake 90 Sr recovery operations from spent fuel reprocessing at SRP, Hanford, and the Barnwell Nuclear Fuels Plant (BNFP). 90 Sr recovery from the existing alkaline high level waste (HLW) at Hanford and SRP is not attractive because the isotopic purity of the 90 Sr is below that required for DOD applications. Without reprocessing LWR spent fuel, SRP and Hanford could not supply the demand of 1 MW thermal until FY 1996. Between FY 1983 and FY 1996, SRP and Hanford could supply approximately 0.70 MW of 90 Sr and 0.15 MW of 147 Pm. SRP could supply an additional 0.15 MW from the production and recovery of 238 Pu. Strontium-90 is the most economical of the three heat source radionuclides considered. The 90 Sr unit recovery cost from SRP fresh acid waste would be $180/watt. The BNFP 90 Sr recovery cost would be $130/watt to $235/watt depending on the age and burnup of the LWR spent fuel. Hanford 90 Sr recovery costs form Purex fresh acid waste are unavailable, but they are expected to be comparable to the SRP costs. 147 Pm and 238 Pu are considerably more expensive heat source materials. 147 Pm recovery costs at SRP are estimated to be $450/watt. As with 90 Sr, the Hanford 147 Pm recovery costs are expected to be comparabl to the SRP costs. Production of high assay (93.5%) 238 Pu at SRP from excess 231 Np would cost about $1160/watt, while recovery of low assay (27%) 238 Pu from the waste stream is estimated at $1850/watt

  9. Thermal hydraulic analysis of the encapsulated nuclear heat source

    Energy Technology Data Exchange (ETDEWEB)

    Sienicki, J.J.; Wade, D.C. [Argonne National Lab., IL (United States)

    2001-07-01

    An analysis has been carried out of the steady state thermal hydraulic performance of the Encapsulated Nuclear Heat Source (ENHS) 125 MWt, heavy liquid metal coolant (HLMC) reactor concept at nominal operating power and shutdown decay heat levels. The analysis includes the development and application of correlation-type analytical solutions based upon first principles modeling of the ENHS concept that encompass both pure as well as gas injection augmented natural circulation conditions, and primary-to-intermediate coolant heat transfer. The results indicate that natural circulation of the primary coolant is effective in removing heat from the core and transferring it to the intermediate coolant without the attainment of excessive coolant temperatures. (authors)

  10. The impact of in-canopy wind profile formulations on heat flux estimation in an open orchard using the remote sensing-based two-source model

    Directory of Open Access Journals (Sweden)

    C. Cammalleri

    2010-12-01

    Full Text Available For open orchard and vineyard canopies containing significant fractions of exposed soil (>50%, typical of Mediterranean agricultural regions, the energy balance of the vegetation elements is strongly influenced by heat exchange with the bare soil/substrate. For these agricultural systems a "two-source" approach, where radiation and turbulent exchange between the soil and canopy elements are explicitly modelled, appears to be the only suitable methodology for reliably assessing energy fluxes. In strongly clumped canopies, the effective wind speed profile inside and below the canopy layer can strongly influence the partitioning of energy fluxes between the soil and vegetation components. To assess the impact of in-canopy wind profile on model flux estimates, an analysis of three different formulations is presented, including algorithms from Goudriaan (1977, Massman (1987 and Lalic et al. (2003. The in-canopy wind profile formulations are applied to the thermal-based two-source energy balance (TSEB model developed by Norman et al. (1995 and modified by Kustas and Norman (1999. High resolution airborne remote sensing images, collected over an agricultural area located in the western part of Sicily (Italy comprised primarily of vineyards, olive and citrus orchards, are used to derive all the input parameters needed to apply the TSEB. The images were acquired from June to October 2008 and include a relatively wide range of meteorological and soil moisture conditions. A preliminary sensitivity analysis of the three wind profile algorithms highlights the dependence of wind speed just above the soil/substrate to leaf area index and canopy height over the typical range of canopy properties encountered in these agricultural areas. It is found that differences among the models in wind just above the soil surface are most significant under sparse and medium fractional cover conditions (15–50%. The TSEB model heat flux estimates are compared with micro

  11. Ground-source heat pump barometer

    International Nuclear Information System (INIS)

    Anon.

    2011-01-01

    In Europe the ground-source heat pump market contracted for the second year running by 2.9% between 2009 and 2010. Around 103.000 units were sold in 2010, taking the number of installed units over one million. The 3 European countries with the most sales are Sweden (31953 units, +16%), Germany (25516 units, -13%) and France (12250 units, -21%). The drop in sales is generally due to market contraction on the current recession but some specificities exist: for instance the insufficient training of the installers has led to under-performance and to a bad image of this energy in France. The Swedish and German manufacturers are in a very strong position and are increasing their market share in the main European markets. (A.C.)

  12. Desalination using low grade heat sources

    Science.gov (United States)

    Gude, Veera Gnaneswar

    A new, low temperature, energy-efficient and sustainable desalination system has been developed in this research. This system operates under near-vacuum conditions created by exploiting natural means of gravity and barometric pressure head. The system can be driven by low grade heat sources such as solar energy or waste heat streams. Both theoretical and experimental studies were conducted under this research to evaluate and demonstrate the feasibility of the proposed process. Theoretical studies included thermodynamic analysis and process modeling to evaluate the performance of the process using the following alternate energy sources for driving the process: solar thermal energy, solar photovoltaic/thermal energy, geothermal energy, and process waste heat emissions. Experimental studies included prototype scale demonstration of the process using grid power as well as solar photovoltaic/thermal sources. Finally, the feasibility of the process in reclaiming potable-quality water from the effluent of the city wastewater treatment plant was studied. The following results have been obtained from theoretical analysis and modeling: (1) The proposed process can produce up to 8 L/d of freshwater for 1 m2 area of solar collector and evaporation chamber respectively with a specific energy requirement of 3122 kJ for 1 kg of freshwater production. (2) Photovoltaic/thermal (PV/T) energy can produce up to 200 L/d of freshwater with a 25 m2 PV/T module which meets the electricity needs of 21 kWh/d of a typical household as well. This configuration requires a specific energy of 3122 kJ for 1 kg of freshwater production. (3) 100 kg/hr of geothermal water at 60°C as heat source can produce up to 60 L/d of freshwater with a specific energy requirement of 3078 kJ for 1 kg of freshwater production. (4) Waste heat released from an air conditioning system rated at 3.25 kW cooling, can produce up to 125 L/d of freshwater. This configuration requires an additional energy of 208 kJ/kg of

  13. Start-up Characteristics of Swallow-tailed Axial-grooved Heat Pipe under the conditions of Multiple Heat Sources

    Science.gov (United States)

    Zhang, Renping

    2017-12-01

    A mathematical model was developed for predicting start-up characteristics of Swallow-tailed Axial-grooved Heat Pipe under the conditions of Multiple Heat Sources. The effects of heat capacitance of heat source, liquid-vapour interfacial evaporation-condensation heat transfer, shear stress at the interface was considered in current model. The interfacial evaporating mass flow rate is based on the kinetic analysis. Time variations of evaporating mass rate, wall temperature and liquid velocity are studied from the start-up to steady state. The calculated results show that wall temperature demonstrates step transition at the junction between the heat source and non-existent heat source on the evaporator. The liquid velocity changes drastically at the evaporator section, however, it has slight variation at the evaporator section without heat source. When the effect of heat source is ignored, the numerical temperature demonstrates a quicker response. With the consideration of capacitance of the heat source, the data obtained from the proposed model agree well with the experimental results.

  14. A feasible system integrating combined heating and power system with ground-source heat pump

    International Nuclear Information System (INIS)

    Li, HongQiang; Kang, ShuShuo; Yu, Zhun; Cai, Bo; Zhang, GuoQiang

    2014-01-01

    A system integrating CHP (combined heating and power) subsystem based on natural gas and GSHP (ground-source heat pump subsystem) in series is proposed. By help of simulation software-Aspen Plus, the energy performance of a typical CHP and GSHP-S (S refers to ‘in series’) system was analyzed. The results show that the system can make a better use of waste heat in flue gas from CHP (combined heating and power subsystem). The total system energy efficiency is 123% and the COP (coefficient of performance) of GSHP (ground-source heat pump) subsystem is 5.3. A referenced CHP and GSHP-P (P refers to ‘in parallel’) system is used for comparison; its total system energy efficiency and COP of GSHP subsystem are 118.6% and 3.5 respectively. Compared with CHP and GSHP-P system with different operating parameters, the CHP and GSHP-S system can increase total system energy efficiency by 0.8–34.7%, with related output ratio of heat to power (R) from 1.9 to 18.3. Furthermore, the COP of GSHP subsystem can be increased between the range 3.6 and 6, which is much higher than that in conventional CHP and GSHP-P system. This study will be helpful for other efficient GSHP systems integrating if there is waste heat or other heat resources with low temperature. - Highlights: • CHP system based on natural gas and ground source heat pump. • The new system can make a better utilization of waste heat in flue gas by a special way. • The proposed system can realize energy saving potential from 0.8 to 34.7%. • The coefficient of performance of ground source heat pump subsystem is significantly improved from 3.5 to 3.6–6. • Warm water temperature and percentage of flue gas used to reheat are key parameters

  15. Heat transfer analysis of underground U-type heat exchanger of ground source heat pump system.

    Science.gov (United States)

    Pei, Guihong; Zhang, Liyin

    2016-01-01

    Ground source heat pumps is a building energy conservation technique. The underground buried pipe heat exchanging system of a ground source heat pump (GSHP) is the basis for the normal operation of an entire heat pump system. Computational-fluid-dynamics (CFD) numerical simulation software, ANSYS-FLUENT17.0 have been performed the calculations under the working conditions of a continuous and intermittent operation over 7 days on a GSHP with a single-well, single-U and double-U heat exchanger and the impact of single-U and double-U buried heat pipes on the surrounding rock-soil temperature field and the impact of intermittent operation and continuous operation on the outlet water temperature. The influence on the rock-soil temperature is approximately 13 % higher for the double-U heat exchanger than that of the single-U heat exchanger. The extracted energy of the intermittent operation is 36.44 kw·h higher than that of the continuous mode, although the running time is lower than that of continuous mode, over the course of 7 days. The thermal interference loss and quantity of heat exchanged for unit well depths at steady-state condition of 2.5 De, 3 De, 4 De, 4.5 De, 5 De, 5.5 De and 6 De of sidetube spacing are detailed in this work. The simulation results of seven working conditions are compared. It is recommended that the side-tube spacing of double-U underground pipes shall be greater than or equal to five times of outer diameter (borehole diameter: 180 mm).

  16. Conjugated heat transfer of natural convection in pool with internal heat sources and convection in the tube

    International Nuclear Information System (INIS)

    Li Longjian; Liu Hongtao; Cui Wenzhi

    2007-01-01

    The conjugated heat transfer of natural convection in pool with internal heat source and the forced convection in the tube was analyzed, and the corresponding three-dimensional physical and mathematical model was proposed. A control volume based finite element method was employed to solve numerically the problem. The computations were performed for different internal heat source intensity of the pool and the different flow velocity in the tube. The computed heat transfer coefficients on the inner and outer wall showed well consistency of those calculated with the empirical correlations. Compared with the measured total heat transfer coefficients between the fluids in and out of the tube, the computed ones showed also the well consistency, which implied that the numerical model proposed in this paper was reliable. The research results revealed that the total heat transfer coefficients between the fluids were strongly affected by the internal heat source intensity of the pool liquid and the flow velocity in the tube. (authors)

  17. Supply of Prague with heat from a nuclear heat source

    International Nuclear Information System (INIS)

    Poul, F.

    1976-01-01

    The proposals are discussed of supplying Prague, the Czechoslovak Capital, with nuclear reactor-generated heat energy. The proposals meet the requirements of the general urban plan of development. The first nuclear heating plant is to be sited in the Kojetice locality, in the northern Prague suburb. It will be commissioned by 1984 and 1985. It is estimated that the maximum heat output in form of hot water will be 821 MW. By 1995 the construction of the second nuclear heating plant should be started southeast or east of Prague. The connection of these two nuclear plants to the hot water mains together with other conventional heating plants will secure the heat supply for Prague and its new housing estates and industrial works. (Oy)

  18. Increase of COP for heat transformer in water purification systems. Part I - Increasing heat source temperature

    International Nuclear Information System (INIS)

    Siqueiros, J.; Romero, R.J.

    2007-01-01

    The integration of a water purification system in a heat transformer allows a fraction of heat obtained by the heat transformer to be recycled, increasing the heat source temperature. Consequently, the evaporator and generator temperatures are also increased. For any operating conditions, keeping the condenser and absorber temperatures and also the heat load to the evaporator and generator, a higher value of COP is obtained when only the evaporator and generator temperatures are increased. Simulation with proven software compares the performance of the modeling of an absorption heat transformer for water purification (AHTWP) operating with water/lithium bromide, as the working fluid-absorbent pair. Plots of enthalpy-based coefficients of performance (COP ET ) and the increase in the coefficient of performance (COP) are shown against absorber temperature for several thermodynamic operating conditions. The results showed that proposed (AHTWP) system is capable of increasing the original value of COP ET more than 120%, by recycling part of the energy from a water purification system. The proposed system allows to increase COP values from any experimental data for water purification or any other distillation system integrated to a heat transformer, regardless of the actual COP value and any working fluid-absorbent pair

  19. Solar heating as a major source of energy for Australia

    Energy Technology Data Exchange (ETDEWEB)

    Morse, R. N.

    1977-07-01

    Solar energy can make its most effective contribution to Australian primary energy in the form of heat for industrial applications. About 50% of all end use energy is required as heat and it is estimated that 40% of this amounting to 1 EJ/a by 2000 could be supplied by solar heat generating systems. This would be 12% of estimated primary energy requirements by that time, and could help reduce the country's increasing dependence on imported oil. Energy self-sufficiency for Australia is possible, based on coal, solar energy and natural gas as primary energy sources. The reason for the present orientation towards residential solar water heaters is that there are many places where electric power for water heating costs between 2 and 4 cents per kWh which makes a solar water heater an attractive proposition. There is also a growing interest in the solar heating of swimming pools, mostly for private homes but also in larger installations for public and institutional pools. Industrial applications, on the other hand, are inhibited by the current low energy prices in Australia, which in some cases are around 0.13 cents/MJ (.47 cents/kWh). Industry, however, uses 40% of Australian primary energy, and represents by far the greatest potential for solar heat generating systems. Demonstration plants are being planned to obtain data on capital and running costs, and at the same time build up professional design and constructional skills in this area. The first demonstration solar industrial process heating system was commissioned in December 1976 and supplies portion of the heat requirements of a soft drink plant in conjunction with the existing oil fired boiler. Integrated solar/oil fired systems of this sort ensure continuous operation of the plant and over a year can result in significant oil savings.

  20. Solar heating as a major source of energy for Australia

    Energy Technology Data Exchange (ETDEWEB)

    Morse, R.N.

    1977-07-01

    Solar energy can make its most effective contribution to Australian primary energy in the form of heat for industrial applications. About 50% of all end use energy is required as heat and it is estimated that 40% of this amounting to 1 EJ/a by 2000 could be supplied by solar heat generating systems. This would be 12% of estimated primary energy requirements by that time, and could help reduce the country's increasing dependence on imported oil. Energy self-sufficiency for Australia is possible, based on coal, solar energy and natural gas as primary energy sources. The reason for the present orientation towards residential solar water heaters is that there are many places where electric power for water heating costs between 2 and 4 cents per kWh which makes a solar water heater an attractive proposition. There is also a growing interest in the solar heating of swimming pools, mostly for private homes but also in larger installations for public and institutional pools. Industrial applications, on the other hand, are inhibited by the current low energy prices in Australia, which in some cases are around 0.13 cents/MJ (.47 cents/kWh). Industry, however, uses 40% of Australian primary energy, and represents by far the greatest potential for solar heat generating systems. Demonstration plants are being planned to obtain data on capital and running costs, and at the same time build up professional design and constructional skills in this area. The first demonstration solar industrial process heating system was commissioned in December 1976 and supplies portion of the heat requirements of a soft drink plant in conjunction with the existing oil fired boiler. Integrated solar/oil fired systems of this sort ensure continuous operation of the plant and over a year can result in significant oil savings.

  1. Mapping of low temperature heat sources in Denmark

    DEFF Research Database (Denmark)

    Bühler, Fabian; Holm, Fridolin Müller; Huang, Baijia

    2015-01-01

    heat. The total accessible waste heat potential is found to be approximately 266 PJ per year with 58 % of it below 100 °C. In the natural heat category, temperatures below 20 °C originate from ambient air, sea water and shallow geothermal energy, and temperatures up to 100 °C are found for solar...... and deep geothermal energy. The theoretical solar thermal potential alone would be above 500 PJ per year. For the development of advanced thermodynamic cycles for the integration of heat sources in the Danish energy system, several areas of interest are determined. In the maritime transport sector a high......Low temperature heat sources are available in many applications, ranging from waste heat from industrial processes and buildings to geothermal and solar heat sources. Technical advancements, such as heat pumps with novel cycle design and multi-component working fluids, make the utilisation of many...

  2. Experimental study of adsorption chiller driven by variable heat source

    Energy Technology Data Exchange (ETDEWEB)

    Wang, D.C.; Wang, Y.J.; Zhang, J.P.; Tian, X.L. [College of Electromechanical Engineering, Qingdao University, Qingdao 266071 (China); Wu, J.Y. [Institute of Refrigeration and Cryogenics, Shanghai Jiao Tong University, Shanghai 200030 (China)

    2008-05-15

    A silica gel-water adsorption chiller has been developed in recent years and has been applied in an air conditioning system driven by solar energy. The heat source used to drive the adsorption chiller is variable at any moment because the solar radiation intensity or the waste heat from engines varies frequently. An adsorption cooling system may be badly impacted by a variable heat source with temperature variations in a large range. In this work, a silica gel-water adsorption chiller driven by a variable heat source is experimentally studied. The influences of the variable heat source on the performance of the chiller are analyzed, especially for a continuous temperature increase process and a continuous temperature decrease process of the heat source. As an example, the dynamic characteristics of the heat source are also analyzed when solar energy is taken as the heat source of the adsorption chiller. According to the experimental results for the adsorption chiller and the characteristics of the heat source from solar energy, control strategies of the adsorption chiller driven by solar energy are proposed. (author)

  3. Experimental study of adsorption chiller driven by variable heat source

    International Nuclear Information System (INIS)

    Wang, D.C.; Wang, Y.J.; Zhang, J.P.; Tian, X.L.; Wu, J.Y.

    2008-01-01

    A silica gel-water adsorption chiller has been developed in recent years and has been applied in an air conditioning system driven by solar energy. The heat source used to drive the adsorption chiller is variable at any moment because the solar radiation intensity or the waste heat from engines varies frequently. An adsorption cooling system may be badly impacted by a variable heat source with temperature variations in a large range. In this work, a silica gel-water adsorption chiller driven by a variable heat source is experimentally studied. The influences of the variable heat source on the performance of the chiller are analyzed, especially for a continuous temperature increase process and a continuous temperature decrease process of the heat source. As an example, the dynamic characteristics of the heat source are also analyzed when solar energy is taken as the heat source of the adsorption chiller. According to the experimental results for the adsorption chiller and the characteristics of the heat source from solar energy, control strategies of the adsorption chiller driven by solar energy are proposed

  4. Integrated multiscale simulation of combined heat and power based district heating system

    International Nuclear Information System (INIS)

    Li, Peifeng; Nord, Natasa; Ertesvåg, Ivar Ståle; Ge, Zhihua; Yang, Zhiping; Yang, Yongping

    2015-01-01

    Highlights: • Simulation of power plant, district heating network and heat users in detail and integrated. • Coupled calculation and analysis of the heat and pressure losses of the district heating network. • District heating is not preferable for very low heat load due to relatively high heat loss. • Lower design supply temperatures of the district heating network give higher system efficiency. - Abstract: Many studies have been carried out separately on combined heat and power and district heating. However, little work has been done considering the heat source, the district heating network and the heat users simultaneously, especially when it comes to the heating system with large-scale combined heat and power plant. For the purpose of energy conservation, it is very important to know well the system performance of the integrated heating system from the very primary fuel input to the terminal heat users. This paper set up a model of 300 MW electric power rated air-cooled combined heat and power plant using Ebsilon software, which was validated according to the design data from the turbine manufacturer. Then, the model of heating network and heat users were developed based on the fundamental theories of fluid mechanics and heat transfer. Finally the combined heat and power based district heating system was obtained and the system performances within multiscale scope of the system were analyzed using the developed Ebsilon model. Topics with regard to the heat loss, the pressure drop, the pump power consumption and the supply temperatures of the district heating network were discussed. Besides, the operational issues of the integrated system were also researched. Several useful conclusions were drawn. It was found that a lower design primary supply temperature of the district heating network would give a higher seasonal energy efficiency of the integrated system throughout the whole heating season. Moreover, it was not always right to relate low design

  5. The ion source development for neutral injection heating at JAERI

    International Nuclear Information System (INIS)

    Shirakata, H.; Itoh, T.; Kondoh, U.; Matsuda, S.; Ohara, Y.; Ohga, T.; Shibata, T.; Sugawara, T.; Tanaka, S.

    1976-01-01

    The neutral beam research and development effort at JAERI has been mainly concentrated on design, construction and testing of ion sources needed for present and planned heating experiments. Fundamental characteristics of the ion sources developed are described

  6. Heat sources for heat pumps in the energetic and economic comparison

    International Nuclear Information System (INIS)

    Bockelmann, Franziska; Fisch, M. Norbert; Schlosser, Mathias; Peter, Markus

    2016-01-01

    Because of the growing application of heat pumps also the number of potentially usable low-temperature heat sources and corresponding heat exchangers for heat-pump systems present in the market increases. Thereby products like energy fences, high-power piles, ore ice reservoir come into applications without any knowledge ab out their power or the cost-profit ratio. The optimized lay-out of the coupling to the building are however essential conditions in order to reach an energy-efficient and durable operation of the facilities. The research project ''future heat pump'' sponsored by the BMWi is dedicated to the energetic and economic evaluation of heat sources for heat pumps. In this connection a pre-check-tool for the preliminary selection of low-temperature heat sources and connected, suitable heat-exchange systems is developed and their actual status of development presented. The holistic, comparing consideration of the different heat sources and heat-exchanger systems is related among others to the power numbers of the heat pumps, the entry and withdrawal services of the heat-exchangers, and the general performance of the systems. Additionally an estimation of economic and ecologic aspects (investment and operation costs, CO_2 emissions) is made. Aim is the determination of the plausibility of applications and essential boundary conditions of single source systems. For the qualitative comparison in a project-accompanying monitoring different facilities and source systems are measurement-technically comprehended.

  7. Solar-Radiation Heating as a Possible Heat Source for Dehydration of Hydrous Carbonaceous Chondrites

    Science.gov (United States)

    Nakamura, T.; Golabek, G.; Ohtsuka, K.; Matsuoka, M.

    2017-07-01

    We have calculated time-dependent temperature profiles of near surface layers of primitive Near Sun Asteroid (3200) Phaethon and found that solar radiation heating is a possible heat source for dehydration of carbonaceous chondrites.

  8. Heat-source specification 500 watt(e) RTG

    International Nuclear Information System (INIS)

    1983-02-01

    This specification establishes the requirements for a 90 SrF 2 heat source and its fuel capsule for application in a 500 W(e) thermoelectric generator. The specification covers: fuel composition and quantity; the Hastelloy S fuel capsule material and fabrication; and the quality assurance requirements for the assembled heat source

  9. Sources for high frequency heating. Performance and limitations

    International Nuclear Information System (INIS)

    Le Gardeur, R.

    1976-01-01

    The various problems encountered in high frequency heating of plasmas can be decomposed into three spheres of action: theoretical development, antenna designing, and utilization of power sources. By classifying heating into three spectral domains, present and future needs are enumerated. Several specific antenna designs are treated. High frequency power sources are reviewed. The actual development of the gyratron is discussed in view of future needs in very high frequency heating of plasmas [fr

  10. Slowpoke - a new Canadian heat source

    International Nuclear Information System (INIS)

    Bancroft, A.R.; Lynch, G.F.; Ohta, M.M.

    1987-07-01

    Atomic Energy of Canada Limited now has a new product, the SLOWPOKE Energy System, that provides low temperature heat suitable for building and process heating. The SLOWPOKE Energy System is sized to deliver up to 10 megawatts of hot water at up to 90 degrees C, appropriate for large buildings and industrial processes. It is designed for operation without the full-time attendance of dedicated staff and, because of its inherent safety, for siting close to users. At less than 2 cents/kWh, the heat is competitive with oil, gas and electricity in most regions of Canada and the world

  11. A novel design method for ground source heat pump

    Directory of Open Access Journals (Sweden)

    Dong Xing-Jie

    2014-01-01

    Full Text Available This paper proposes a novel design method for ground source heat pump. The ground source heat pump operation is controllable by using several parameters, such as the total meters of buried pipe, the space between wells, the thermal properties of soil, thermal resistance of the well, the initial temperature of soil, and annual dynamic load. By studying the effect of well number and well space, we conclude that with the increase of the well number, the inlet and outlet water temperatures decrease in summer and increase in winter, which enhance the efficiency of ground source heat pump. The well space slightly affects the water temperatures, but it affects the soil temperature to some extent. Also the ground source heat pump operations matching with cooling tower are investigated to achieve the thermal balance. This method greatly facilitates ground source heat pump design.

  12. Efficiency of the heat pump cooperating with various heat sources in monovalent and bivalent systems

    Energy Technology Data Exchange (ETDEWEB)

    Kurpaska, S.; Latala, H. [Krakow Univ. of Agriculture, Krakow (Poland). Inst. of Agricultural Engineering and Computer Science

    2010-07-01

    This paper reported on a study that tested the efficiency of compressor heat pumps cooperating with various types of lower heat sources such as horizontal ground heat exchangers, vertical exchangers and sources operating in the bivalent system. The system for receiving energy consisted of a traditional heating system and liquid-air exchangers. The study identified a strong relationship between the heating efficiency of the analysed systems and temperature inside the structure. The study showed that the bivalent system was fully capable of meeting a heat requirement of about 1 MJ -2.

  13. A key review of wastewater source heat pump (WWSHP) systems

    International Nuclear Information System (INIS)

    Hepbasli, Arif; Biyik, Emrah; Ekren, Orhan; Gunerhan, Huseyin; Araz, Mustafa

    2014-01-01

    Highlights: • Comprehensively reviewing WWSHP systems for the first time. • Varying the COP values for heating of the reviewed systems between 1.77 and 10.63. • Ranging the COP values for cooling of the reviewed systems from 2.23 to 5.35. • Being the majority of the performance assessments on the energetic basis. - Abstract: Heat pumps (HPs) are part of the environmentally friendly technologies using renewable energy and have been utilized in the developed countries for years. Wastewater is seen as a renewable heat source for HPs. At the beginning of the 1980s, waste (sewage) water source heat pumps (WWSHPs) were widely applied in North European countries like Sweden and Norway and partially applied in China. In the past two decades, the WWSHP has become increasingly popular due to its advantages of relatively higher energy utilization efficiency and environmental protection. The present study comprehensively reviews WWSHP systems in terms of applications and performance assessments including energetic, exergetic, environmental and economic aspects for the first time to the best of the authors’ knowledge. In this context, a historical development of WWSHPs was briefly given first. Next, wastewater potential and its characteristics were presented while a WWSHP system was introduced. The previously conducted studies on WWSHPs were then reviewed and classified in a tabulated form. Finally, some concluding remarks were listed. The COP values of the reviewed studies ranged from 1.77 to 10.63 for heating and 2.23 to 5.35 for cooling based on the experimental and simulated values. The performance assessments are mostly made using energy analysis methods while the number of exergetic evaluations is very low and has not been comprehensively performed. It is expected that the comprehensive review here will be very beneficial to those dealing with the design, analysis, simulation and performance assessment of WWSHP systems

  14. Application of Abaqus to analysis of the temperature field in elements heated by moving heat sources

    Directory of Open Access Journals (Sweden)

    W. Piekarska

    2010-10-01

    Full Text Available Numerical analysis of thermal phenomena occurring during laser beam heating is presented in this paper. Numerical models of surface andvolumetric heat sources were presented and the influence of different laser beam heat source power distribution on temperature field wasanalyzed. Temperature field was obtained by a numerical solution the transient heat transfer equation with activity of inner heat sources using finite element method. Temperature distribution analysis in welded joint was performed in the ABAQUS/Standard solver. The DFLUXsubroutine was used for implementation of the movable welding heat source model. Temperature-depended thermophysical properties for steelwere assumed in computer simulations. Temperature distribution in laser beam surface heated and butt welded plates was numericallyestimated.

  15. Performance variations of river water source heat pump system according to heat exchanger capacity variations

    International Nuclear Information System (INIS)

    Park, Seong Ryong; Baik, Young Jin; Lee, Young Soo; Kim, Hee Hwan

    2003-01-01

    The utilization of unused energy is important because it can afford to offer a chance to increase energy efficiency of a heat pump system. One of the promising unused energy sources is river water. It can be used as a heat source in both heating and cooling effectively with its superior features as a secondary working fluids. In this study, the performance of a 5HP heat pump system using river water as a heat source is investigated by both experiment and simulation. According to system simulation results, performance improvement of condenser seems more effective than that of evaporator for better COPH. The serial connection is also preferred among several methods to improve plate type heat exchanger performance. The experimental results show that the hot water of 50∼60 .deg. C can be acquired from water heat source of 5∼9 .deg. C with COPH of 2.7∼3.5

  16. Air source absorption heat pump in district heating: Applicability analysis and improvement options

    International Nuclear Information System (INIS)

    Wu, Wei; Shi, Wenxing; Li, Xianting; Wang, Baolong

    2015-01-01

    Highlights: • Applicability of air source absorption heat pump (ASAHP) district heating is studied. • Return temperature and energy saving rate (ESR) in various conditions are optimized. • ASAHP is more suitable for shorter distance or lower temperature district heating. • Two options can reduce the primary return temperature and improve the applicability. • The maximum ESR is improved from 13.6% to 20.4–25.6% by compression-assisted ASAHP. - Abstract: The low-temperature district heating system based on the air source absorption heat pump (ASAHP) was assessed to have great energy saving potential. However, this system may require smaller temperature drop leading to higher pump consumption for long-distance distribution. Therefore, the applicability of ASAHP-based district heating system is analyzed for different primary return temperatures, pipeline distances, pipeline resistances, supplied water temperatures, application regions, and working fluids. The energy saving rate (ESR) under different conditions are calculated, considering both the ASAHP efficiency and the distribution consumption. Results show that ASAHP system is more suitable for short-distance district heating, while for longer-distance heating, lower supplied hot water temperature is preferred. In addition, the advantages of NH 3 /H 2 O are inferior to those of NH 3 /LiNO 3 , and the advantages for warmer regions and lower pipeline resistance are more obvious. The primary return temperatures are optimized to obtain maximum ESRs, after which the suitable distances under different acceptable ESRs are summarized. To improve the applicability of ASAHP, the integration of cascaded heat exchanger (CHX) and compression-assisted ASAHP (CASAHP) are proposed, which can reduce the primary return temperature. The integration of CHX can effectively improve the applicability of ASAHP under higher supplied water temperatures. As for the utilization of CASAHP, higher compression ratio (CR) is better in

  17. Geothermal energy. Ground source heat pumps

    International Nuclear Information System (INIS)

    2009-01-01

    Geothermal energy can be harnessed in 2 different ways: electricity or heat generation. The combined net electrical geothermal power of the European Union countries reached 719.3 MWe in 2008 (4.8 MW up on 2007) for 868.1 MWe of installed capacity. Gross electrical production contracted slightly in 2008 (down 1% on the 2007 level) and stood at 5809.5 GWh in 2008. Italy has a overwhelming position with a production of 5520.3 GWh. Geothermal heat production concerning aquifers whose temperature is 30-150 C. degrees generally at a depth of 1-3 km is called low- and medium-enthalpy energy. 18 of the 27 EU members use low- and medium-enthalpy energy totaling 2560.0 MWth of installed capacity that yielded 689.2 ktoe in 2008 and 3 countries Hungary, Italy and France totaling 480.3 ktoe. Very low-enthalpy energy concerns the exploitation of shallow geothermal resources using geothermal heat pumps. In 2008, 114452 ground heat pumps were sold in Europe. At the end of 2008, the installed capacity was 8955.4 MWth (16.5% up on 2007 level, it represented 785206 pumps. Over one million ground heat pumps are expected to be operating in 2010 in Europe. (A.C.)

  18. General purpose heat source task group. Final report

    International Nuclear Information System (INIS)

    1979-01-01

    The results of thermal analyses and impact tests on a modified design of a 238 Pu-fueled general purpose heat source (GPHS) for spacecraft power supplies are presented. This work was performed to establish the safety of a heat source with pyrolytic graphite insulator shells located either inside or outside the graphite impact shell. This safety is dependent on the degree of aerodynamic heating of the heat source during reentry and on the ability of the heat source capsule to withstand impact after reentry. Analysis of wind tunnel and impact test data result in a recommended GPHS design which should meet all temperature and safety requirements. Further wind tunnel tests, drop tests, and impact tests are recommended to verify the safety of this design

  19. Second Sound for Heat Source Localization

    CERN Document Server

    Vennekate, Hannes; Uhrmacher, Michael; Quadt, Arnulf; Grosse-Knetter, Joern

    2011-01-01

    Defects on the surface of superconducting cavities can limit their accelerating gradient by localized heating. This results in a phase transition to the normal conduction state | a quench. A new application, involving Oscillating Superleak Transducers (OST) to locate such quench inducing heat spots on the surface of the cavities, has been developed by D. Hartill et al. at Cornell University in 2008. The OSTs enable the detection of heat transfer via second sound in super uid helium. This thesis presents new results on the analysis of their signal. Its behavior has been studied for dierent circumstances at setups at the University of Gottingen and at CERN. New approaches for an automated signal processing have been developed. Furthermore, a rst test setup for a single-cell Superconducting Proton Linac (SPL) cavity has been prepared. Recommendations of a better signal retrieving for its operation are presented.

  20. The Closing Wells as Heat Source

    Directory of Open Access Journals (Sweden)

    Gonet Andrzej

    2004-09-01

    Full Text Available The Turaszówka crude oil field is situated within the borders of Krosno town. The oil resources are nearly depleted. Many of the boreholes have already been liquidated. Currently, only 22 boreholes are being exploited. Eight of them are watered and exploiting oil along with the reservoir water.The boreholes were submitted for producing the geothermal energy, because of their location. They are situated within the urban area. The suggested solution allows for gaining the pure energy and also does not require additional expenditure for mining researches connected with closing of the abandoned boreholes of the field.The paper points to the suggestion and preliminary analysis for wells of Turaszówka oil field adaptation for borehole heat exchangers. There is also presentation of using the heat for Complex of Upper Grammar School heating system and the swimming pool which are both placed close to the oil field.

  1. Source effects on impurity and heat transport in a tokamak

    International Nuclear Information System (INIS)

    Bennett, R.B.

    1980-12-01

    A recently developed generalization of neoclassical theory is extended here to study heat flux contributions to impurity transport, as well as the heat fluxes themselves. The theory accounts for the first four source moments, with external drags, which has been studied previously with either fewer moments or restricted to a collisional plasma. Conditions are established for which a momentum source may be used to modify the particle and heat transport. In the course of this work, the particle and heat transport is evaluated for a two species plasma with arbitrary plasma geometry, beta, and collisionality

  2. Performance analysis on solar-water compound source heat pump for radiant floor heating system

    Institute of Scientific and Technical Information of China (English)

    曲世林; 马飞; 仇安兵

    2009-01-01

    A solar-water compound source heat pump for radiant floor heating (SWHP-RFH) experimental system was introduced and analyzed. The SWHP-RFH system mainly consists of 11.44 m2 vacuum tube solar collector,1 000 L water tank assisted 3 kW electrical heater,a water source heat pump,the radiant floor heating system with cross-linked polyethylene (PE-X) of diameter 20 mm,temperature controller and solar testing system. The SWHP-RFH system was tested from December to February during the heating season in Beijing,China under different operation situations. The test parameters include the outdoor air temperature,solar radiation intensity,indoor air temperature,radiation floor average surface temperature,average surface temperature of the building envelope,the inlet and outlet temperatures of solar collector,the temperature of water tank,the heat medium temperatures of heat pump condenser side and evaporator side,and the power consumption includes the water source heat pump system,the solar source heat pump system,the auxiliary heater and the radiant floor heating systems etc. The experimental results were used to calculate the collector efficiency,heat pump dynamic coefficient of performance (COP),total energy consumption and seasonal heating performance during the heating season. The results indicate that the performance of the compound source heat pump system is better than that of the air source heat pump system. Furthermore,some methods are suggested to improve the thermal performance of each component and the whole SWHP-RFH system.

  3. The economics of supplying the supplementary heat in a closed loop water source heat pump system

    International Nuclear Information System (INIS)

    Johnson, R.P.; Bartkus, V.E.; Singh, J.B.

    1993-01-01

    The paper describes the details of a research and demonstration project that will be completed in August 1992 at a healthcare facility in northeastern Pennsylvania. The purpose of the project is to compare the economics of several methods of supplying the supplementary heating in a facility served by a closed loop water source heat pump system. The systems being tested include a storage hot water tank with electric resistance heaters and three air source heat pumps that have the ability to supply the same heat during on-peak hours as well as off-peak hours. The paper compares the projected operating costs of the following: (1) Gas boiler supplying the supplementary heat. (2) Stored hot water supplying the supplementary heat which is generated and stored during off-peak hours using resistance heat on PP ampersand L's offpeak rate. (3) Stored hot water supplying the supplementary heat generated during off-peak hours using the air source heat pumps on PP ampersand L's off-peak rate. (4) Hot water generated by the air source heat pumps supplying the supplementary loop heating on PP ampersand L's general service and time-of-day electric rates. It is generally known in the HVAC industry that a closed loop water source heat pump system can provide one of the most efficient means of space conditioning to a building with high internal gains by transferring the excess heat available in one part of the building to another part of the building where it may be needed for heating. The following flow diagram depicts the relationship of the air source heat pumps with the storage tanks and the building closed water loop

  4. SELECTION OF HEAT SUPPLY SOURCE FOR MOBILE BUILDING STRUCTURE

    OpenAIRE

    T. I. Dolgikh; S. V. Morozov; Yu. P. Orlov; A. B. Reis; A. Yu Yakovlev

    2014-01-01

    The paper proposes a vortex heat generator with energy transformation of the highest  state  of matter motion  into  the  lowest  one  as  a  heat  supply  source  for a mobile object. Energy transformation coefficient indices close or equal to 1 have been obtained as a result of experiments on efficiency of the vortex heat generator. Such results can be explained with the help of the 2nd Bohr quantum postulate. Standard series of certified VTG heat generators has been proposed for heat suppl...

  5. Nuclear heat source design for an advanced HTGR process heat plant

    International Nuclear Information System (INIS)

    McDonald, C.F.; O'Hanlon, T.W.

    1983-01-01

    A high-temperature gas-cooled reactor (HTGR) coupled with a chemical process facility could produce synthetic fuels (i.e., oil, gasoline, aviation fuel, methanol, hydrogen, etc.) in the long term using low-grade carbon sources (e.g., coal, oil shale, etc.). The ultimate high-temperature capability of an advanced HTGR variant is being studied for nuclear process heat. This paper discusses a process heat plant with a 2240-MW(t) nuclear heat source, a reactor outlet temperature of 950 0 C, and a direct reforming process. The nuclear heat source outputs principally hydrogen-rich synthesis gas that can be used as a feedstock for synthetic fuel production. This paper emphasizes the design of the nuclear heat source and discusses the major components and a deployment strategy to realize an advanced HTGR process heat plant concept

  6. Heat pumps using vertical boreholls as heat source; Varmepumper med lodrette boringer som varmeoptager

    Energy Technology Data Exchange (ETDEWEB)

    Pedersen, Svend V. [Teknologisk Institut, Aarhus (Denmark); Thoegersen, L.; Soerensen, Inga [VIA University College, Risskov (Denmark)] [and others

    2013-01-15

    This report presents instructions on what to consider when you have to establish vertical wells as energy sources for ground source heating systems. The report provides an introduction into what to be aware of when it comes to sizing vertical ground hoses as heat absorbers for heat pumps. The initial geological assessments, you have to make are described and there are references to the available tools and websites that exist today. A calculation model is developed for the design of vertical ground hoses. This calculation model is intended as a tool for installers and consultants as well as well drillers. The calculation model contains two computational models, one can be used for initial calculations and dimensioning of vertical ground hoses, and the detailed model can be used for costing by well driller. The simple calculation is based on proven design approach from the German standard VDI 4640, and the detailed calculation is based on a known empirical calculation, which assumes that you know the geology in more detail. In the project measurements were carried out on four installations, and the calculations show that there is good agreement between the measurements and the calculation model. (LN)

  7. An Empirical Temperature Variance Source Model in Heated Jets

    Science.gov (United States)

    Khavaran, Abbas; Bridges, James

    2012-01-01

    An acoustic analogy approach is implemented that models the sources of jet noise in heated jets. The equivalent sources of turbulent mixing noise are recognized as the differences between the fluctuating and Favre-averaged Reynolds stresses and enthalpy fluxes. While in a conventional acoustic analogy only Reynolds stress components are scrutinized for their noise generation properties, it is now accepted that a comprehensive source model should include the additional entropy source term. Following Goldstein s generalized acoustic analogy, the set of Euler equations are divided into two sets of equations that govern a non-radiating base flow plus its residual components. When the base flow is considered as a locally parallel mean flow, the residual equations may be rearranged to form an inhomogeneous third-order wave equation. A general solution is written subsequently using a Green s function method while all non-linear terms are treated as the equivalent sources of aerodynamic sound and are modeled accordingly. In a previous study, a specialized Reynolds-averaged Navier-Stokes (RANS) solver was implemented to compute the variance of thermal fluctuations that determine the enthalpy flux source strength. The main objective here is to present an empirical model capable of providing a reasonable estimate of the stagnation temperature variance in a jet. Such a model is parameterized as a function of the mean stagnation temperature gradient in the jet, and is evaluated using commonly available RANS solvers. The ensuing thermal source distribution is compared with measurements as well as computational result from a dedicated RANS solver that employs an enthalpy variance and dissipation rate model. Turbulent mixing noise predictions are presented for a wide range of jet temperature ratios from 1.0 to 3.20.

  8. Elastic unloading of a disk after plastic deformation by a circular heat source

    International Nuclear Information System (INIS)

    Gamer, U.; Mack, W.

    1987-01-01

    Subject of the investigation is the transient stress distribution in an elastic-plastic disk acted upon by a circular heat source. The disk serves as a mechanical model of the rotating anode of an X-ray-tube. The calculation is based on Tresca's yield criterion and the flow rule associatd to it. During heating, a plastic region spreads around the source, which is absorbed by an unloaded zone after the removal of the source. (orig.) [de

  9. Applications of New Chemical Heat Sources Phase 1

    National Research Council Canada - National Science Library

    Bell, William

    2001-01-01

    Report developed under Small Business Innovative Research (SBIR) contract. This project has examined the application of new chemical heat sources, with emphasis on portable heaters for military field rations...

  10. Transient thermal stress distribution in a circular pipe heated externally with a periodically moving heat source

    International Nuclear Information System (INIS)

    Özışık, Gülşah; Genç, M. Serdar; Yapıcı, Hüseyin

    2012-01-01

    This study presents the effects of periodically moving heat source on a circular steel pipe heated partly from its outer surface under stagnant ambient conditions. While the pipe is heated with this heat source applied on a certain section having a thickness of heat flux, the water flows through it to transfer heat. It is assumed that the flow is a fully-developed laminar flow. The heat source moves along from one end of the outer to the other end with a constant speed and then returns to the first end with the same speed. It is assumed that the heat transfer rate has a constant value, and that the thermo-physical properties of the steel do not change with temperature (elastic analysis). The numerical calculations have been performed individually for a wide range of thermal conductivity of steel and for different thicknesses of heat flux. The moving heat source produces the non-uniform temperature gradient and the non-uniform effective thermal stress, and when it arrives at the ends of the pipe, the temperature and effective thermal stress ratio profiles rise more excessively. The tangential component is more dominant in the effective thermal stress than the radial component. Highlights: ► Moving heat source produces non-uniform temperature gradients and thermal stresses. ► When moving heat source arrives at ends of pipe, temperature gradients rise excessively. ► With increasing of heat flux thickness and thermal conductivity, the temperature gradients reduce. ► Temperature gradients in thermal boundary layers slightly increase. ► Tangential component is more dominant in thermal stress than radial component.

  11. Trends in Solar energy Driven Vertical Ground Source Heat Pump Systems in Sweden - An Analysis Based on the Swedish Well Database

    Science.gov (United States)

    Juhlin, K.; Gehlin, S.

    2016-12-01

    Sweden is a world leader in developing and using vertical ground source heat pump (GSHP) technology. GSHP systems extract passively stored solar energy in the ground and the Earth's natural geothermal energy. Geothermal energy is an admitted renewable energy source in Sweden since 2007 and is the third largest renewable energy source in the country today. The Geological Survey of Sweden (SGU) is the authority in Sweden that provides open access geological data of rock, soil and groundwater for the public. All wells drilled must be registered in the SGU Well Database and it is the well driller's duty to submit registration of drilled wells.Both active and passive geothermal energy systems are in use. Large GSHP systems, with at least 20 boreholes, are active geothermal energy systems. Energy is stored in the ground which allows both comfort heating and cooling to be extracted. Active systems are therefore relevant for larger properties and industrial buildings. Since 1978 more than 600 000 wells (water wells, GSHP boreholes etc) have been registered in the Well Database, with around 20 000 new registrations per year. Of these wells an estimated 320 000 wells are registered as GSHP boreholes. The vast majority of these boreholes are single boreholes for single-family houses. The number of properties with registered vertical borehole GSHP installations amounts to approximately 243 000. Of these sites between 300-350 are large GSHP systems with at least 20 boreholes. While the increase in number of new registrations for smaller homes and households has slowed down after the rapid development in the 80's and 90's, the larger installations for commercial and industrial buildings have increased in numbers over the last ten years. This poster uses data from the SGU Well Database to quantify and analyze the trends in vertical GSHP systems reported between 1978-2015 in Sweden, with special focus on large systems. From the new aggregated data, conclusions can be drawn about

  12. Swedish Homeowners' Attitude towards Water-Based Heating Systems

    Energy Technology Data Exchange (ETDEWEB)

    Gustavsson, L; Mahapatra, K [Mid Sweden Univ., Ecotechnology, SE-831 25 Oestersund (Sweden)

    2008-10-15

    In 2004 and 2007, we conducted questionnaire surveys of 1,500 randomly selected Swedish homeowners of detached houses to understand their attitude towards adopting an innovative heating system (IHS). The results showed that there was no substantial change in homeowners' attitude towards IHSs. More than 80% of the respondents did not intend to install a new heating system. Economic aspects and functional reliability were the most important factors in the respondents' choice of heating system while environmental factors were of less importance. Installers were the most frequently consulted source of information on heating systems. Respondents perceived the relative advantage of pellet boilers over oil or electricity-based heating systems, but bedrock heat pump system was ranked higher than pellet heating system in every aspect except for investment cost. Pellet heating system has advantages with respect to investment cost. District heating system was considered as most functionally reliable and automatic. Keywords: Heat sector, socio-economic aspects, market implementation

  13. Renewable-based heat supply of multi-apartment buildings with varied heat demands

    International Nuclear Information System (INIS)

    Truong, Nguyen Le; Dodoo, Ambrose; Gustavsson, Leif

    2015-01-01

    This study investigates the cost and primary energy use to heat an existing multi-apartment building in Sweden, before and after deep energy efficiency renovation, with different types of renewable-based systems. District heating systems of different scales as well as local heat production based on bioelectric boilers, ground-source bioelectric heat pumps and wood pellet boilers with or without solar heating are considered. The annual energy demand of the building, calculated hour by hour, with and without energy efficiency improvements, are matched against the renewable-based heat supply options by techno-economic modeling to minimize cost for each considered heat supply option. The results show that the availability of heating technologies at the building site and the scale of the building's heat demand influence the cost and the primary energy efficiency of the heating options. District heat from large-scale systems is cost efficient for the building without energy-efficiency improvement, whereas electric heat pumps and wood pellet boilers are more cost efficient when implementing energy-efficiency improvement. However, the cost difference is small between these alternatives and sensitive to the size of building. Large-scale district heating with cogeneration of power is most primary energy efficient while heat pumps and medium-scale district heating are nearly as efficient. - Highlights: • Heating technologies influence costs and primary energy use of a building. • Large-scale district heating with cogeneration of power is primary energy efficient. • Large-scale district heating is cost efficient for buildings with large heat demand. • Heat pumps and pellet boilers are cost competitive in energy-efficient buildings.

  14. Free convection flow of some fractional nanofluids over a moving vertical plate with uniform heat flux and heat source

    Science.gov (United States)

    Azhar, Waqas Ali; Vieru, Dumitru; Fetecau, Constantin

    2017-08-01

    Free convection flow of some water based fractional nanofluids over a moving infinite vertical plate with uniform heat flux and heat source is analytically and graphically studied. Exact solutions for dimensionless temperature and velocity fields, Nusselt numbers, and skin friction coefficients are established in integral form in terms of modified Bessel functions of the first kind. These solutions satisfy all imposed initial and boundary conditions and reduce to the similar solutions for ordinary nanofluids when the fractional parameters tend to one. Furthermore, they reduce to the known solutions from the literature when the plate is fixed and the heat source is absent. The influence of fractional parameters on heat transfer and fluid motion is graphically underlined and discussed. The enhancement of heat transfer in such flows is higher for fractional nanofluids in comparison with ordinary nanofluids. Moreover, the use of fractional models allows us to choose the fractional parameters in order to get a very good agreement between experimental and theoretical results.

  15. A directly heated electron beam line source

    International Nuclear Information System (INIS)

    Iqbal, M.; Masood, K.; Rafiq, M.; Chaudhry, M.A.

    2002-05-01

    A 140-mm cathode length, Electron Beam Line Source with a high degree of focusing of the beam is constructed. The design principles and basic characteristic considerations for electron beam line source consists of parallel plate electrode geometric array as well as a beam power of 35kW are worked out. The dimensions of the beam at the work site are 1.25xl00mm. The gun is designed basically for the study of evaporation and deposition characteristic of refractory metals for laboratory use. However, it may be equally used for melting and casting of these metals. (author)

  16. EFFECT OF THE TYPE OF HEAT SOURCES ON CARBON DIOXIDE EMISSIONS

    Directory of Open Access Journals (Sweden)

    Sławomir Rabczak

    2016-11-01

    Full Text Available A lot of attention is nowadays devoted to the problem of generally defined ecology. It is absolutely essential in case of systems and sources generating heat due to their direct influence on the environment through emitting post-process products to the atmosphere which are, most frequently a result of combustion. Therefore, constant searchers are made to optimize the operation of heat sources and to acquire energy from sources for which the general balance of carbon dioxide emission is zero or close to zero. This work compares the emissions of equivalent CO2 from selected systems with the following heat sources: coal, gas furnace, heat pump, and refers results of the analysis to aspects connected with regulations concerning environmental protection. The systems generating thermal energy in the gas furnaces, coal, biomass, as well as the compression heat pumps with the lower heat source as ambient air or ground were taken under consideration, as well as centralized systems for the production of heat based on the combustion of coal, gas, oil, and biomass. the Emission of carbon dioxide for the installation of cogeneration and absorption heat pump were also calculated. Similarly obtained amount of extra emission necessary for the proper operation maintenance of heating devices via the supplied electricity from external source, the mostly fuel-fired power plants for fuels as previously mentioned. The results of the calculations were presented in tables and graphs.

  17. Post-evaluation of a ground source heat pump system for residential space heating in Shanghai China

    Science.gov (United States)

    Lei, Y.; Tan, H. W.; Wang, L. Z.

    2017-11-01

    Residents of Southern China are increasingly concerned about the space heating in winter. The chief aim of the present work is to find a cost-effective way for residential space heating in Shanghai, one of the biggest city in south China. Economic and energy efficiency of three residential space heating ways, including ground source heat pump (GSHP), air source heat pump (ASHP) and wall-hung gas boiler (WHGB), are assessed based on Long-term measured data. The results show that the heat consumption of the building is 120 kWh/m2/y during the heating season, and the seasonal energy efficiency ratio (SEER) of the GSHP, ASHP and WHGB systems are 3.27, 2.30, 0.88 respectively. Compared to ASHP and WHGB, energy savings of GSHP during the heating season are 6.2 kgce/(m2.y) and 2.2 kgce/(m2.y), and the payback period of GSHP are 13.3 and 7.6 years respectively. The sensitivity analysis of various factors that affect the payback period is carried out, and the results suggest that SEER is the most critical factor affecting the feasibility of ground source heat pump application, followed by building load factor and energy price factor. These findings of the research have led the author to the conclusion that ground source heat pump for residential space heating in Shanghai is a good alternative, which can achieve significant energy saving benefits, and a good system design and operation management are key factors that can shorten the payback period.

  18. Operation characteristic of a R123-based organic Rankine cycle depending on working fluid mass flow rates and heat source temperatures

    International Nuclear Information System (INIS)

    Feng, Yong-Qiang; Hung, Tzu-Chen; Wu, Shang-Lun; Lin, Chih-Hung; Li, Bing-Xi; Huang, Kuo-Chen; Qin, Jiang

    2017-01-01

    Highlights: • The operation characteristic of an Organic Rankine Cycle using R123 and a scroll expander have been investigated. • The behaviors and detailed discussion for those four major components are examined. • The expander isentropic efficiency presents a slight decrease first and then a sharp increase with mass flow rate. • The maximum electrical power and system generation efficiency are 2.01 kW and 3.25%, respectively. - Abstract: The test and operation characteristic of an organic Rankine cycle using R123 and a scroll expander have been investigated. The steady-state operation characteristic is addressed with the varying working fluid mass flow rates ranging of 0.124–0.222 kg/s and heat source temperatures ranging of 383.15–413.15 K. The behaviors and detailed discussion for those four major components (pump, evaporator, expander and condenser) are examined. The experimental results show that the environmental temperature presents a higher influence on the pump behaviors. The range of pump power consumption, isentropic efficiency and back work ratio are 0.21–0.32 kW, 26.76–53.96%, and 14–32%, respectively. The expander isentropic efficiency presents a slight decrease first and then a sharp increase with mass flow rate, while a degree of superheating more than 3 K is necessary to avoid expander cavitation. The expander isentropic and generator efficiencies are in range of 69.10–85.17% and 60–73%, respectively, while the respective heat transfer coefficients for evaporator and condenser are ranging of 200–400 and 450–2000 W/m"2 K. The maximum expander shaft power and electrical power are 2.78 kW and 2.01 kW, respectively, while the maximum system generating efficiency is 3.25%. Moreover, the tested thermal efficiency presents a slight decrease trend with mass flow rate.

  19. Thermodynamic performance analysis of sequential Carnot cycles using heat sources with finite heat capacity

    International Nuclear Information System (INIS)

    Park, Hansaem; Kim, Min Soo

    2014-01-01

    The maximum efficiency of a heat engine is able to be estimated by using a Carnot cycle. Even though, in terms of efficiency, the Carnot cycle performs the role of reference very well, its application is limited to the case of infinite heat reservoirs, which is not that realistic. Moreover, considering that one of the recent key issues is to produce maximum work from low temperature and finite heat sources, which are called renewable energy sources, more advanced theoretical cycles, which can present a new standard, and the research about them are necessary. Therefore, in this paper, a sequential Carnot cycle, where multiple Carnot cycles are connected in parallel, is studied. The cycle adopts a finite heat source, which has a certain initial temperature and heat capacity, and an infinite heat sink, which is assumed to be ambient air. Heat transfer processes in the cycle occur with the temperature difference between a heat reservoir and a cycle. In order to resolve the heat transfer rate in those processes, the product of an overall heat transfer coefficient and a heat transfer area is introduced. Using these conditions, the performance of a sequential Carnot cycle is analytically calculated. Furthermore, as the efforts for enhancing the work of the cycle, the optimization research is also conducted with numerical calculation. - Highlights: • Modified sequential Carnot cycles are proposed for evaluating low grade heat sources. • Performance of sequential Carnot cycles is calculated analytically. • Optimization study for the cycle is conducted with numerical solver. • Maximum work from a heat source under a certain condition is obtained by equations

  20. Energy source completion for geothermal district heating systems

    International Nuclear Information System (INIS)

    Popovski, Kiril

    2000-01-01

    Geothermal district heating systems differs from the others mainly in the part of energy source completion and its connection to the heat distribution systems rather known problem. Even rather known problematic in the countries where geothermal energy is in wide application, new appearances of mistakes are always present due to the fact that necessary literature is difficult to be found. Essentials of the geothermal well completion and connection of geothermal source to the district heating distribution system are summarized in the paper and several examples of geothermal projects in flow are presented. (Author)

  1. Heat source reconstruction from noisy temperature fields using an optimised derivative Gaussian filter

    Science.gov (United States)

    Delpueyo, D.; Balandraud, X.; Grédiac, M.

    2013-09-01

    The aim of this paper is to present a post-processing technique based on a derivative Gaussian filter to reconstruct heat source fields from temperature fields measured by infrared thermography. Heat sources can be deduced from temperature variations thanks to the heat diffusion equation. Filtering and differentiating are key-issues which are closely related here because the temperature fields which are processed are unavoidably noisy. We focus here only on the diffusion term because it is the most difficult term to estimate in the procedure, the reason being that it involves spatial second derivatives (a Laplacian for isotropic materials). This quantity can be reasonably estimated using a convolution of the temperature variation fields with second derivatives of a Gaussian function. The study is first based on synthetic temperature variation fields corrupted by added noise. The filter is optimised in order to reconstruct at best the heat source fields. The influence of both the dimension and the level of a localised heat source is discussed. Obtained results are also compared with another type of processing based on an averaging filter. The second part of this study presents an application to experimental temperature fields measured with an infrared camera on a thin plate in aluminium alloy. Heat sources are generated with an electric heating patch glued on the specimen surface. Heat source fields reconstructed from measured temperature fields are compared with the imposed heat sources. Obtained results illustrate the relevancy of the derivative Gaussian filter to reliably extract heat sources from noisy temperature fields for the experimental thermomechanics of materials.

  2. Ground Source Integrated Heat Pump (GS-IHP) Development

    Energy Technology Data Exchange (ETDEWEB)

    Baxter, V. D. [ORNL; Rice, K. [ORNL; Murphy, R. [ORNL; Munk, J. [ORNL; Ally, Moonis [ORNL; Shen, Bo [ORNL; Craddick, William [ORNL; Hearn, Shawn A. [ClimateMaster, Inc.

    2013-05-24

    Between October 2008 and May 2013 ORNL and ClimateMaster, Inc. (CM) engaged in a Cooperative Research and Development Agreement (CRADA) to develop a groundsource integrated heat pump (GS-IHP) system for the US residential market. A initial prototype was designed and fabricated, lab-tested, and modeled in TRNSYS (SOLAR Energy Laboratory, et al, 2010) to predict annual performance relative to 1) a baseline suite of equipment meeting minimum efficiency standards in effect in 2006 (combination of air-source heat pump (ASHP) and resistance water heater) and 2) a state-of-the-art (SOA) two-capacity ground-source heat pump with desuperheater water heater (WH) option (GSHPwDS). Predicted total annual energy savings, while providing space conditioning and water heating for a 2600 ft{sup 2} (242 m{sup 2}) house at 5 U.S. locations, ranged from 52 to 59%, averaging 55%, relative to the minimum efficiency suite. Predicted energy use for water heating was reduced 68 to 78% relative to resistance WH. Predicted total annual savings for the GSHPwDS relative to the same baseline averaged 22.6% with water heating energy use reduced by 10 to 30% from desuperheater contributions. The 1st generation (or alpha) prototype design for the GS-IHP was finalized in 2010 and field test samples were fabricated for testing by CM and by ORNL. Two of the alpha units were installed in 3700 ft{sup 2} (345 m{sup 2}) houses at the ZEBRAlliance site in Oak Ridge and field tested during 2011. Based on the steady-state performance demonstrated by the GS-IHPs it was projected that it would achieve >52% energy savings relative to the minimum efficiency suite at this specific site. A number of operational issues with the alpha units were identified indicating design changes needed to the system before market introduction could be accomplished. These were communicated to CM throughout the field test period. Based on the alpha unit test results and the diagnostic information coming from the field test

  3. Infant otitis media and the use of secondary heating sources.

    Science.gov (United States)

    Pettigrew, Melinda M; Gent, Janneane F; Triche, Elizabeth W; Belanger, Kathleen D; Bracken, Michael B; Leaderer, Brian P

    2004-01-01

    This prospective study investigated the association of exposure to indoor secondary heating sources with otitis media and recurrent otitis media risk in infants. We enrolled mothers living in nonsmoking households and delivering babies between 1993 and 1996 in 12 Connecticut and Virginia hospitals. Biweekly telephone interviews during the first year of life assessed diagnoses from doctors' office visits and use of secondary home heating sources, air conditioner use, and day care. Otitis media episodes separated by more than 21 days were considered to be unique episodes. Recurrent otitis media was defined as 4 or more episodes of otitis media. Repeated-measures logistic regression modeling evaluated the association of kerosene heater, fireplace, or wood stove use with otitis media episodes while controlling for potential confounders. Logistic regression evaluated the relation of these secondary heating sources with recurrent otitis media. None of the secondary heating sources were associated with otitis media or with recurrent otitis media. Otitis media was associated with day care, the winter heating season, birth in the fall, white race, additional children in the home, and a maternal history of allergies in multivariate models. Recurrent otitis media was associated with day care, birth in the fall, white race, and a maternal history of allergies or asthma. We found no evidence that the intermittent use of secondary home heating sources increases the risk of otitis media or recurrent otitis media. This study confirms earlier findings regarding the importance of day care with respect to otitis media risk.

  4. Research status and evaluation system of heat source evaluation method for central heating

    Science.gov (United States)

    Sun, Yutong; Qi, Junfeng; Cao, Yi

    2018-02-01

    The central heating boiler room is a regional heat source heating center. It is also a kind of the urban environment pollution, it is an important section of building energy efficiency. This article through to the evaluation method of central heating boiler room and overviews of the researches during domestic and overseas, summarized the main influence factors affecting energy consumption of industrial boiler under the condition of stable operation. According to the principle of establishing evaluation index system. We can find that is great significance in energy saving and environmental protection for the content of the evaluation index system of the centralized heating system.

  5. Helium release from radioisotope heat sources

    Energy Technology Data Exchange (ETDEWEB)

    Peterson, D.E.; Early, J.W.; Starzynski, J.S.; Land, C.C.

    1984-05-01

    Diffusion of helium in /sup 238/PuO/sub 2/ fuel was characterized as a function of the heating rate and the fuel microstructure. The samples were thermally ramped in an induction furnace and the helium release rates measured with an automated mass spectrometer. The diffusion constants and activation energies were obtained from the data using a simple diffusion model. The release rates of helium were correlated with the fuel microstructure by metallographic examination of fuel samples. The release mechanism consists of four regimes, which are dependent upon the temperature. Initially, the release is controlled by movement of point defects combined with trapping along grain boundaries. This regime is followed by a process dominated by formation and growth of helium bubbles along grain boundaries. The third regime involves volume diffusion controlled by movement of oxygen vacancies. Finally, the release at the highest temperatures follows the diffusion rate of intragranular bubbles. The tendency for helium to be trapped within the grain boundaries diminishes with small grain sizes, slow thermal pulses, and older fuel.

  6. Helium release from radioisotope heat sources

    International Nuclear Information System (INIS)

    Peterson, D.E.; Early, J.W.; Starzynski, J.S.; Land, C.C.

    1984-05-01

    Diffusion of helium in 238 PuO 2 fuel was characterized as a function of the heating rate and the fuel microstructure. The samples were thermally ramped in an induction furnace and the helium release rates measured with an automated mass spectrometer. The diffusion constants and activation energies were obtained from the data using a simple diffusion model. The release rates of helium were correlated with the fuel microstructure by metallographic examination of fuel samples. The release mechanism consists of four regimes, which are dependent upon the temperature. Initially, the release is controlled by movement of point defects combined with trapping along grain boundaries. This regime is followed by a process dominated by formation and growth of helium bubbles along grain boundaries. The third regime involves volume diffusion controlled by movement of oxygen vacancies. Finally, the release at the highest temperatures follows the diffusion rate of intragranular bubbles. The tendency for helium to be trapped within the grain boundaries diminishes with small grain sizes, slow thermal pulses, and older fuel

  7. 太阳能双能源吸收式热泵耦合地埋管地源热泵供热——基于工程实例的分析与总结%Heating by dual energy solar absorption heat pump coupling ground-source heat pump——Analysis and summary based on an engineering example

    Institute of Scientific and Technical Information of China (English)

    宋晨; 王东博

    2017-01-01

    Based on an engineering example,analyses the design of the dual energy solar absorption heat pump system and the ground-source heat pump system,determines the system form and equipment parameter configuration.Optimizes and analyses the coupling heating design of the two systems and the operation modes under different targets,determines the system coupling mode and the operation modes for different targets.%以工程实例为基础,对太阳能双能源吸收式热泵及地埋管地源热泵供热系统的设计进行了分析,确定了系统形式及设备参数配置.对2种系统形式的耦合供热设计及基于不同目标下的运行方式进行了优化分析,确定了系统耦合方式及针对不同目标的运行方式.

  8. New waste heat district heating system with combined heat and power based on absorption heat exchange cycle in China

    International Nuclear Information System (INIS)

    Sun Fangtian; Fu Lin; Zhang Shigang; Sun Jian

    2012-01-01

    A new waste heat district heating system with combined heat and power based on absorption heat exchange cycle (DHAC) was developed to increase the heating capacity of combined heat and power (CHP) through waste heat recovery, and enhance heat transmission capacity of the existing primary side district heating network through decreasing return water temperature by new type absorption heat exchanger (AHE). The DHAC system and a conventional district heating system based on CHP (CDH) were analyzed in terms of both thermodynamics and economics. Compared to CDH, the DHAC increased heating capacity by 31% and increased heat transmission capacity of the existing primary side district heating network by 75%. The results showed that the exergetic efficiency of DHAC was 10.41% higher and the product exergy monetary cost was 36.6¥/GJ less than a CHD. DHAC is an effective way to increase thermal utilization factor of CHP, and to reduce district heating cost. - Highlights: ► Absorption heat pumps are used to recover waste heat in CHP. ► Absorption heat exchanger can reduce exergy loss in the heat transfer process. ► New waste heat heating system (DHAC) can increase heating capacity of CHP by 31%. ► DHAC can enhance heat transmission capacity of the primary pipe network by 75%. ► DHAC system has the higher exergetic efficiency and the better economic benefit.

  9. Laser heated solenoid as a neutron source facility

    International Nuclear Information System (INIS)

    Steinhauer, L.C.; Rose, P.H.

    1975-01-01

    Conceptual designs are presented for a radiation test facility based on a laser heated plasma confined in a straight solenoid. The thin plasma column, a few meters in length and less than a centimeter in diameter, serves as a line source of neutrons. Test samples are located within or just behind the plasma tube, at a radius of 1-2 cm from the axis. The plasma is heated by an axially-directed powerful long-wavelength laser beam. The plasma is confined radially in the intense magnetic field supplied by a pulsed solenoid surrounding the plasma tube. The facility is pulsed many times a second to achieve a high time-averaged neutron flux on the test samples. Based on component performance achievable in the near term (e.g., magnetic field, laser pulse energy) and assuming classical physical processes, it appears that average fluxes of 10 13 to 10 14 neutrons/cm 2 -sec can be achieved in such a device. The most severe technical problems in such a facility appear to be rapid pulsing design and lifetime of some electrical and laser components

  10. Welding of iridium heat source capsule components

    International Nuclear Information System (INIS)

    Mustaleski, T.M.; Yearwood, J.C.; Burgan, C.E.; Green, L.A.

    1991-01-01

    Interplanetary spacecraft have long used radioisotope thermoelectric generators (RTG) to produce power for instrumentation. These RTG produce electrical energy from the heat generated through the radioactive decay of plutonium-238. The plutonium is present as a ceramic pellet of plutonium oxide. The pellet is encapsulated in a containment shell of iridium. Iridium is the material of choice for these capsules because of its compatibility with the plutonium dioxide. The high-energy beam welding (electron beam and laser) processes used in the fabrication of the capsules has not been published. These welding procedures were originally developed at the Mound Laboratories and have been adapted for use at the Oak Ridge Y-12 Plant. The work involves joining of thin material in small sizes to exacting tolerances. There are four different electron beam welds on each capsule, with one procedure being used in three locations. There is also a laser weld used to seal the edges of a sintered frit assembly. An additional electron beam weld is also performed to seal each of the iridium blanks in a stainless steel waster sheet prior to forming. In the transfer of these welding procedures from one facility to another, a number of modifications were necessary. These modifications are discussed in detail, as well as the inherent problems in making welds in material which is only 0.005 in. thick. In summary, the paper discusses the welding of thin components of iridium using the high energy beam processes. While the peculiarities of iridium are pertinent to the discussion, much of the information is of general interest to the users of these processes. This is especially true of applications involving thin materials and high-precision assemblies

  11. Ground Source Geothermal District Heating and Cooling System

    Energy Technology Data Exchange (ETDEWEB)

    Lowe, James William [Ball State Univ., Muncie, IN (United States)

    2016-10-21

    Ball State University converted its campus from a coal-fired steam boiler district heating system to a ground source heat pump geothermal district system that produces simultaneously hot water for heating and chilled water for cooling. This system will include the installation of 3,600 four hundred feet deep vertical closed loop boreholes making it the largest ground source geothermal district system in the country. The boreholes will act as heat exchangers and transfer heat by virtue of the earth’s ability to maintain an average temperature of 55 degree Fahrenheit. With growing international concern for global warming and the need to reduce worldwide carbon dioxide loading of the atmosphere geothermal is poised to provide the means to help reduce carbon dioxide emissions. The shift from burning coal to utilizing ground source geothermal will increase electrical consumption but an overall decrease in energy use and reduction in carbon dioxide output will be achieved. This achievement is a result of coupling the ground source geothermal boreholes with large heat pump chiller technology. The system provides the thermodynamic means to move large amounts of energy with limited energy input. Ball State University: http://cms.bsu.edu/About/Geothermal.aspx

  12. Hydrogen production from coal using a nuclear heat source

    International Nuclear Information System (INIS)

    Quade, R.N.

    1977-01-01

    A strong candidate for hydrogen production in the intermediate time frame of 1990 to 1995 is a coal-based process using a high-temperature gas-cooled reactor (HTGR) as a heat source. Expected process efficiencies in the range of 60 to 70% are considerably higher than all other hydrogen production processes except steam reforming of a natural gas - a feedstock which may not be available in large quantities in this time frame. The process involves the preparation of a coal liquid, hydrogasification of that liquid, and steam reforming of the resulting gaseous or light liquid product. Bench-scale experimental work on the hydrogasification of coal liquids is being carried out. A study showing process efficiency and cost of hydrogen vs nuclear reactor core outlet temperature has been completed and shows diminishing returns at process temperatures above about 1500 0 F. (author)

  13. Hydrogen production from coal using a nuclear heat source

    Science.gov (United States)

    Quade, R. N.

    1976-01-01

    A strong candidate for hydrogen production in the intermediate time frame of 1985 to 1995 is a coal-based process using a high-temperature gas-cooled reactor (HTGR) as a heat source. Expected process efficiencies in the range of 60 to 70% are considerably higher than all other hydrogen production processes except steam reforming of a natural gas. The process involves the preparation of a coal liquid, hydrogasification of that liquid, and steam reforming of the resulting gaseous or light liquid product. A study showing process efficiency and cost of hydrogen vs nuclear reactor core outlet temperature has been completed, and shows diminishing returns at process temperatures above about 1500 F. A possible scenario combining the relatively abundant and low-cost Western coal deposits with the Gulf Coast hydrogen users is presented which provides high-energy density transportation utilizing coal liquids and uranium.

  14. Environmental assessment for radioisotope heat source fuel processing and fabrication

    International Nuclear Information System (INIS)

    1991-07-01

    DOE has prepared an Environmental Assessment (EA) for radioisotope heat source fuel processing and fabrication involving existing facilities at the Savannah River Site (SRS) near Aiken, South Carolina and the Los Alamos National Laboratory (LANL) near Los Alamos, New Mexico. The proposed action is needed to provide Radioisotope Thermoelectric Generators (RTG) to support the National Aeronautics and Space Administration's (NASA) CRAF and Cassini Missions. Based on the analysis in the EA, DOE has determined that the proposed action does not constitute a major Federal action significantly affecting the quality of the human environment within the meaning of the National Environmental Policy Act (NEPA) of 1969. Therefore, an Environmental Impact Statement is not required. 30 refs., 5 figs

  15. A Study on Conjugate Heat Transfer Analysis of Reactor Vessel including Irradiated Structural Heat Source

    Energy Technology Data Exchange (ETDEWEB)

    Yi, Kunwoo; Cho, Hyuksu; Im, Inyoung; Kim, Eunkee [KEPCO EnC, Daejeon (Korea, Republic of)

    2015-10-15

    Though Material reliability programs (MRPs) have a purpose to provide the evaluation or management methodologies for the operating RVI, the similar evaluation methodologies can be applied to the APR1400 fleet in the design stage for the evaluation of neutron irradiation effects. The purposes of this study are: to predict the thermal behavior whether or not irradiated structure heat source; to evaluate effective thermal conductivity (ETC) in relation to isotropic and anisotropic conductivity of porous media for APR1400 Reactor Vessel. The CFD simulations are performed so as to evaluate thermal behavior whether or not irradiated structure heat source and effective thermal conductivity for APR1400 Reactor Vessel. In respective of using irradiated structure heat source, the maximum temperature of fluid and core shroud for isotropic ETC are 325.8 .deg. C, 341.5 .deg. C. The total amount of irradiated structure heat source is about 5.41 MWth and not effect to fluid temperature.

  16. Simulation of embedded heat exchangers of solar aided ground source heat pump system

    Institute of Scientific and Technical Information of China (English)

    王芳; 郑茂余; 邵俊鹏; 李忠建

    2008-01-01

    Aimed at unbalance of soil temperature field of ground source heat pump system, solar aided energy storage system was established. In solar assisted ground-source heat pump (SAGSHP) system with soil storage, solar energy collected in three seasons was stored in the soil by vertical U type soil exchangers. The heat abstracted by the ground-source heat pump and collected by the solar collector was employed to heating. Some of the soil heat exchangers were used to store solar energy in the soil so as to be used in next winter after this heating period; and the others were used to extract cooling energy directly in the soil by circulation pump for air conditioning in summer. After that solar energy began to be stored in the soil and ended before heating period. Three dimensional dynamic numerical simulations were built for soil and soil heat exchanger through finite element method. Simulation was done in different strata month by month. Variation and restoration of soil temperature were studied. Economy and reliability of long term SAGSHP system were revealed. It can be seen that soil temperature is about 3 ℃ higher than the original one after one year’s running. It is beneficial for the system to operate for long period.

  17. Experimental Study and Modeling of Ground-Source Heat Pumps with Combi-Storage in Buildings

    Directory of Open Access Journals (Sweden)

    Wessam El-Baz

    2018-05-01

    Full Text Available There is a continuous growth of heat pump installations in residential buildings in Germany. The heat pumps are not only used for space heating and domestic hot water consumption but also to offer flexibility to the grid. The high coefficient of performance and the low cost of heat storages made the heat pumps one of the optimal candidates for the power to heat applications. Thus, several questions are raised about the optimal integration and control of heat pump system with buffer storages to maximize its operation efficiency and minimize the operation costs. In this paper, an experimental investigation is performed to study the performance of a ground source heat pump (GSHP with a combi-storage under several configurations and control factors. The experiments were performed on an innovative modular testbed that is capable of emulating a ground source to provide the heat pump with different temperature levels at different times of the day. Moreover, it can emulate the different building loads such as the space heating load and the domestic hot water consumption in real-time. The data gathered from the testbed and different experimental studies were used to develop a simulation model based on Modelica that can accurately simulate the dynamics of a GSHP in a building. The model was validated based on different metrics. Energetically, the difference between the developed model and the measured values was only 3% and 4% for the heat generation and electricity consumption, respectively.

  18. Experimental study on local heat transfer characteristics of porous media with internal heat source

    International Nuclear Information System (INIS)

    Zan Yuanfeng; Wang Taotao; Xiao Zejun; Wang Fei; Huang Yanping

    2008-01-01

    Model of porous media with internal heat source is established. The model uses water as flowing media, and the stainless steel test section is packed with steel spheres in manner of regular triangle, respectively. The armoured resistance wire is inserted inside the steel sphere. On the basis of the experimental model, many parameters of the local heat transfer characteristics including current velocity and wall temperature of steel sphere are measured. The experimental results show that the coefficient of heat transfer scarcely changes with pressure. The coefficient of heat transfer increases with the surface heat flux of steel sphere. When raising the inlet temperature of the cooling water, the coefficient of heat transfer presents the descending trend. In addition, the influence of entrance effect on heat transfer is discovered in the experiment, which is much less than the liquid flow in the light tube. After experiment data are analyzed and processed, the relation model of heat transfer on local heat transfer characteristic of porous media with internal heat source was described with a power-law-equation. The deviations between calculation and experimental values are within ±10%. (authors)

  19. The application of ground source heat pumps to a subdivision-wide district heating system

    International Nuclear Information System (INIS)

    Ciavaglia, L.

    2005-01-01

    Design guidelines for economic ground source heat pumps (GSHP) in district energy systems were presented. The broad economics of using central GSHP in a community district energy system were examined. Design parameters needed to utilize GSHP in district energy system were outlined. The sensitivity of energy prices and the costs of major capital were reviewed. District heating load duration curves were outlined. It was suggested that varying GSHP capacity from 0 to 100 per cent of load was advisable. In addition, capacity should be balanced with gas boiler technology. The amortizing of capital within energy costs was recommended. It was suggested that the best scenario was a minimum of 50 per cent ground energy. Details of pipings and heat exchanger costs were presented, along with costs for gas boilers and gas costs for the district energy system. Charts of current costing and reduction of piping capital were included. It was concluded that GSHP can be a viable component of a district energy system, as a GSHP based district energy system can provide more stable energy prices than conventional fossil fuel systems. It was suggested that sizing of GSHP at, or near, 40 per cent of peak demand provided optimal conditions with respect to energy cost and use of earth energy. tabs., figs

  20. Assessment of dynamic energy conversion systems for radioisotope heat sources

    International Nuclear Information System (INIS)

    Thayer, G.R.; Mangeng, C.A.

    1985-06-01

    The use of dynamic conversion systems to convert the heat generated in a 7500 W(t) 90 Sr radioisotopic heat source to electricity is examined. The systems studies were Stirling; Brayton Cycle; three organic Rankines (ORCs) (Barber-Nichols/ORMAT, Sundstrand, and TRW); and an organic Rankine plus thermoelectrics. The systems were ranked for a North Warning System mission using a Los Alamos Multiattribute Decision Theory code. Three different heat source designs were used: case I with a beginning of life (BOL) source temperature of 640 C, case II with a BOL source temperature of 745 0 C, and case III with a BOL source temperature of 945 0 C. The Stirling engine system was the top-ranked system of cases I and II, closely followed by the ORC systems in case I and ORC plus thermoelectrics in case II. The Brayton cycle system was top-ranked for case III, with the Stirling engine system a close second. The use of 238 Pu in heat source sizes of 7500 W(t) was examined and found to be questionable because of cost and material availability and because of additional requirements for analysis of safeguards and critical mass

  1. Natural convection in wavy enclosures with volumetric heat sources

    International Nuclear Information System (INIS)

    Oztop, H.F.; Varol, Y.; Abu-Nada, E.; Chamkha, A.

    2011-01-01

    In this paper, the effects of volumetric heat sources on natural convection heat transfer and flow structures in a wavy-walled enclosure are studied numerically. The governing differential equations are solved by an accurate finite-volume method. The vertical walls of enclosure are assumed to be heated differentially whereas the two wavy walls (top and bottom) are kept adiabatic. The effective governing parameters for this problem are the internal and external Rayleigh numbers and the amplitude of wavy walls. It is found that both the function of wavy wall and the ratio of internal Rayleigh number (Ra I ) to external Rayleigh number (Ra E ) affect the heat transfer and fluid flow significantly. The heat transfer is predicted to be a decreasing function of waviness of the top and bottom walls in case of (IRa/ERa)>1 and (IRa/ERa)<1. (authors)

  2. Heating effects in a liquid metal ion source

    International Nuclear Information System (INIS)

    Mair, G.L.R.; Aitken, K.L.

    1984-01-01

    A reassessment is made of the heating occurring at the anode of a liquid metal ion source, in the light of new microscopic observations. The apex region of the cones is in the form of a cusp, or jet, even at very low currents. The calculation for ohmic heating is conclusive for low currents; no heating occurs at the anode; for high currents (approx. 50-100 μA), substantial heating is conceivable, if a long, very thin, cylindrical jet exists at the apex of the anode. The answer to the problem of external heating, in the form of electrons bombarding the anode, is not quite conclusive; this is because of the impossibility of correctly assessing the electron flux entering the anode. However, it would appear to be a definite conclusion that for reasons of self-consistency field-ionisation of thermally released atoms cannot be a significant ion emission mechanism. (author)

  3. SELECTION OF HEAT SUPPLY SOURCE FOR MOBILE BUILDING STRUCTURE

    Directory of Open Access Journals (Sweden)

    T. I. Dolgikh

    2014-01-01

    Full Text Available The paper proposes a vortex heat generator with energy transformation of the highest  state  of matter motion  into  the  lowest  one  as  a  heat  supply  source  for a mobile object. Energy transformation coefficient indices close or equal to 1 have been obtained as a result of experiments on efficiency of the vortex heat generator. Such results can be explained with the help of the 2nd Bohr quantum postulate. Standard series of certified VTG heat generators has been proposed for heat supply of the mobile object (field hospital.

  4. The Polyvalent Heat Supply System for Experimental Building of the Passive Type (area of 300 m2 Based on Renewable and Alternative Energy Sources

    Directory of Open Access Journals (Sweden)

    Basok, B.I.

    2014-11-01

    Full Text Available Results of the development and implementation of heat supply system for experimental building of the passive type are presented, optimal operating conditions are investigated, guidelines for the creation of heat supply systems for passive type buildings are provided.

  5. Power generation from low-temperature heat source

    Energy Technology Data Exchange (ETDEWEB)

    Lakew, Amlaku Abie

    2012-07-01

    The potential of low-temperature heat sources for power production has been discussed for decades. The diversity and availability of low-temperature heat sources makes it interesting for power production. The thermodynamic power cycle is one of the promising technologies to produce electricity from low-temperature heat sources. There are different working fluids to be used in a thermodynamic power cycle. Working fluid selection is essential for the performance of the power cycle. Over the last years, different working fluid screening criteria have been used. In broad speaking the screening criteria can be grouped as thermodynamic performance, component size requirement, economic performance, safety and environmental impact. Screening of working fluids at different heat source temperatures (80-200 Celsius degrees) using thermodynamic performance (power output and exergy efficiency) and component size (heat exchanger and turbine) is investigated. It is found that the 'best' working fluid depends on the criteria used and heat source temperature level. Transcritical power cycles using carbon dioxide as a working fluid is studied to produce power at 100 Celsius degrees. Carbon dioxide is an environmentally friendly refrigerant. The global warming potential of carbon dioxide is 1. Furthermore, because of its low critical temperature (31 Celsius degrees), carbon dioxide can operate in a transcritical power cycle for lower heat source temperatures. A transcritical configuration avoids the problem of pinching which otherwise would happened in subcritical power cycle. In the process, better temperature matching is achieved and more heat is extracted. Thermodynamic analysis of transcritical cycle is performed; it is found that there is an optimal operating pressure for highest net power output. The pump work is a sizable fraction of the work produced by the turbine. The effect of efficiency deterioration of the pump and the turbine is compared. When the

  6. Buoyancy induced convective flow in porous media with heat source

    International Nuclear Information System (INIS)

    Hwang, I.T.

    1978-01-01

    An unbounded fluid layer in a porous medium with an internal heat source and uniformly heated from below is studied. The layer is in the gravitational field. Linear theory predicts that the disturbances of infinitesimal amplitude will start to grow when the Rayleigh number exceeds its critical value. These disturbances do not grow without limit; but by advecting heat and momentum, the disturbances alter their forms to achieve a finite amplitude. Just like infinitesimal amplitude disturbances the degeneracies of possible solutions persist for finite amplitude solutions. This study evaluates these various forms of solutions. The small parameter method of Poincare is used to treat the problem in successive order

  7. Development of the Sixty Watt Heat-Source hardware components

    International Nuclear Information System (INIS)

    McNeil, D.C.; Wyder, W.C.

    1995-01-01

    The Sixty Watt Heat Source is a nonvented heat source designed to provide 60 thermal watts of power. The unit incorporates a plutonium-238 fuel pellet encapsulated in a hot isostatically pressed General Purpose Heat Source (GPHS) iridium clad vent set. A molybdenum liner sleeve and support components isolate the fueled iridium clad from the T-111 strength member. This strength member serves as the pressure vessel and fulfills the impact and hydrostatic strength requirements. The shell is manufactured from Hastelloy S which prevents the internal components from being oxidized. Conventional drawing operations were used to simplify processing and utilize existing equipment. The deep drawing reqirements for the molybdenum, T-111, and Hastelloy S were developed from past heat source hardware fabrication experiences. This resulted in multiple step drawing processes with intermediate heat treatments between forming steps. The molybdenum processing included warm forming operations. This paper describes the fabrication of these components and the multiple draw tooling developed to produce hardware to the desired specifications. copyright 1995 American Institute of Physics

  8. Melting of a phase change material in a horizontal annulus with discrete heat sources

    Directory of Open Access Journals (Sweden)

    Mirzaei Hooshyar

    2015-01-01

    Full Text Available Phase change materials have found many industrial applications such as cooling of electronic devices and thermal energy storage. This paper investigates numerically the melting process of a phase change material in a two-dimensional horizontal annulus with different arrangements of two discrete heat sources. The sources are positioned on the inner cylinder of the annulus and assumed as constant-temperature boundary conditions. The remaining portion of the inner cylinder wall as well as the outer cylinder wall is considered to be insulated. The emphasis is mainly on the effects of the arrangement of the heat source pair on the fluid flow and heat transfer features. The governing equations are solved on a non-uniform O type mesh using a pressure-based finite volume method with an enthalpy porosity technique to trace the solid and liquid interface. The results are obtained at Ra=104 and presented in terms of streamlines, isotherms, melting phase front, liquid fraction and dimensionless heat flux. It is observed that, depending on the arrangement of heat sources, the liquid fraction increases both linearly and non-linearly with time but will slow down at the end of the melting process. It can also be concluded that proper arrangement of discrete heat sources has the great potential in improving the energy storage system. For instance, the arrangement C3 where the heat sources are located on the bottom part of the inner cylinder wall can expedite the melting process as compared to the other arrangements.

  9. Heat Source Models in Simulation of Heat Flow in Friction Stir Welding

    DEFF Research Database (Denmark)

    Schmidt, Henrik Nikolaj Blich; Hattel, Jesper

    2004-01-01

    The objective of the present paper is to investigate the effect of including the tool probe and the material flow in the numerical modelling of heat flow in Friction Stir Welding (FSW). The contact condition at the interface between the tool and workpiece controls the heat transfer mechanisms....... The convective heat transfer due to the material flow affects the temperature fields. Models presented previously in literature allow the heat to flow through the probe volume, and the majority of them neglect the influence of the contact condition as the sliding condition is assumed. In the present work......, a number of cases are established. Each case represents a combination of a contact condition, i.e. sliding and sticking, and a stage of refinement regarding the heat source distribution. In the most detailed models the heat flow is forced around the probe volume by prescribing a velocity field in shear...

  10. Heat source models in simulation of heat flow in friction stir welding

    DEFF Research Database (Denmark)

    Schmidt, Henrik Nikolaj Blich; Hattel, Jesper

    2004-01-01

    The objective of the present paper is to investigate the effect of including the tool probe and the material flow in the numerical modelling of heat flow in friction stir welding (FSW). The contact condition at the interface between the tool and workpiece controls the heat transfer mechanisms....... The convective heat transfer due to the material flow affects the temperature fields. Models presented previously in the literature allow the heat to flow through the probe volume, and the majority neglects the influence of the contact condition as the sliding condition is assumed. In this work, a number...... of cases is established. Each case represents a combination of a contact condition, i.e. sliding and sticking, and a stage of refinement regarding the heat source distribution. In the most detailed models, the heat flow is forced around the probe volume by prescribing a velocity field in shear layers...

  11. Performance analysis of a soil-based thermal energy storage system using solar-driven air-source heat pump for Danish buildings sector

    DEFF Research Database (Denmark)

    Jradi, M.; Veje, C.; Jørgensen, B. N.

    2017-01-01

    and the economic and environmental aspects. However, the intermittent nature of solar energy and the lack of high solar radiation intensities in various climates favour the use of various energy storage techniques to eliminate the discrepancy between energy supply and demand. The current work presents an analysis......, Denmark, in addition to charging the soil storage medium in summer months when excess electric power is generated. The stored heat is discharged in December and January to provide the space heating and domestic hot water demands of the residential project without the utilization of an external heating...... losses and the surrounding soil temperature variation throughout the year. It was found that the overall system heating coefficient of performance is around 4.76, where the reported energetic efficiency is 5.88% for the standalone PV system, 19.1% for the combined PV-ASHP system, and 22...

  12. Ground source heat pumps (GSHP) for heating and cooling in Greece

    Science.gov (United States)

    Dimera, Nikoletta

    This report presents the results of a theoretical study about the feasibility of closed loop Ground Source Heat Pumps (GSHP) for heating and cooling in Greece in terms of their impact on the capital and running costs of the building services systems of the buildings. The main aim of carrying out this study was to investigate if the heating and cooling potential of the ground could be utilized cost efficiently to serve the buildings energy demand in the Greek region. At first, an existing implementation of a closed loop GSHP system in Greece is presented and its efficiency is discussed. The aim of doing so was to understand the way of sizing such systems and the efficiency of this technology in Greek climatic and ground conditions. In a separate part of this report, the impact of different user behaviour and of various ways of sizing a GSHP system is investigated in terms of the cost impact of the examined different options as well as of their effect on the internal health and comfort conditions. After the building simulation under different scenarios, it was concluded that the user behavior - the operation of windows mostly - can result in great savings on the annual energy bills. The conclusions of this first part of the report about the user behaviour and the way of sizing GSHP systems were utilized in the next part of it, where a GSHP system is proposed for a building currently under construction in central Greece. A simple 30-year cost analysis was used in order to estimate the performance of the proposed GSHP system in economic terms and to compare it with the conventional HVAC system commonly used in Greece. According to the results of the analysis, the capital cost of installing a GSHP system for heating and cooling in buildings in Greece appears higher than the cost of conventional HVAC systems. More specifically, the capital cost of an installation for heating including gas boilers and a cooling system based on air conditioning split units is about the

  13. Numerical analysis of the heat source characteristics of a two-electrode TIG arc

    International Nuclear Information System (INIS)

    Ogino, Y; Hirata, Y; Nomura, K

    2011-01-01

    Various kinds of multi-electrode welding processes are used to ensure high productivity in industrial fields such as shipbuilding, automotive manufacturing and pipe fabrication. However, it is difficult to obtain the optimum welding conditions for a specific product, because there are many operating parameters, and because welding phenomena are very complicated. In the present research, the heat source characteristics of a two-electrode TIG arc were numerically investigated using a 3D arc plasma model with a focus on the distance between the two electrodes. The arc plasma shape changed significantly, depending on the electrode spacing. The heat source characteristics, such as the heat input density and the arc pressure distribution, changed significantly when the electrode separation was varied. The maximum arc pressure of the two-electrode TIG arc was much lower than that of a single-electrode TIG. However, the total heat input of the two-electrode TIG arc was nearly constant and was independent of the electrode spacing. These heat source characteristics of the two-electrode TIG arc are useful for controlling the heat input distribution at a low arc pressure. Therefore, these results indicate the possibility of a heat source based on a two-electrode TIG arc that is capable of high heat input at low pressures.

  14. Current status of ground-source heat pumps in China

    International Nuclear Information System (INIS)

    Yang Wei; Zhou Jin; Xu Wei; Zhang Guoqiang

    2010-01-01

    As a renewable energy technology, the ground-source heat pump (GSHP) technologies have increasingly attracted world-wide attention due to their advantages of energy efficiency and environmental friendliness. This paper presents Chinese research and application on GSHP followed by descriptions of patents. The policies related to GSHP are also introduced and analyzed. With the support of Chinese government, several new heat transfer models and two new GSHP systems (named pumping and recharging well (PRW) and integrated soil cold storage and ground-source heat pump (ISCS and GSHP) system) have been developed by Chinese researchers. The applications of GSHP systems have been growing rapidly since the beginning of the 21st century with financial incentives and supportive government policies. However, there are still several challenges for the application of GSHP systems in large scale. This paper raises relevant suggestions for overcoming the existing and potential obstacles. In addition, the developing and applying prospects of GSHP systems in China are also discussed.

  15. Absorptivity Measurements and Heat Source Modeling to Simulate Laser Cladding

    Science.gov (United States)

    Wirth, Florian; Eisenbarth, Daniel; Wegener, Konrad

    The laser cladding process gains importance, as it does not only allow the application of surface coatings, but also additive manufacturing of three-dimensional parts. In both cases, process simulation can contribute to process optimization. Heat source modeling is one of the main issues for an accurate model and simulation of the laser cladding process. While the laser beam intensity distribution is readily known, the other two main effects on the process' heat input are non-trivial. Namely the measurement of the absorptivity of the applied materials as well as the powder attenuation. Therefore, calorimetry measurements were carried out. The measurement method and the measurement results for laser cladding of Stellite 6 on structural steel S 235 and for the processing of Inconel 625 are presented both using a CO2 laser as well as a high power diode laser (HPDL). Additionally, a heat source model is deduced.

  16. Weldability of general purpose heat source new-process iridium

    International Nuclear Information System (INIS)

    Kanne, W.R.

    1987-01-01

    Weldability tests on General Purpose Heat Source (GPHS) iridium capsules showed that a new iridium fabrication process reduced susceptibility to underbead cracking. Seventeen capsules were welded (a total of 255 welds) in four categories and the number of cracks in each weld was measured

  17. General-purpose heat source development. Phase I: design requirements

    International Nuclear Information System (INIS)

    Snow, E.C.; Zocher, R.W.

    1978-09-01

    Studies have been performed to determine the necessary design requirements for a 238 PuO 2 General-Purpose Heat Source (GPHS). Systems and missions applications, as well as accident conditions, were considered. The results of these studies, along with the recommended GPHS design requirements, are given in this report

  18. Exergoeconomic analysis of a solar assisted ground-source heat pump greenhouse heating system

    International Nuclear Information System (INIS)

    Ozgener, Onder; Hepbasli, Arif

    2005-01-01

    EXCEM analysis may prove useful to investigators in engineering and other disciplines due to the methodology are being based on the quantities exergy, cost, energy and mass. The main objective of the present study is to investigate between capital costs and thermodynamic losses for devices in solar assisted ground-source heat pump greenhouse heating system (SAGSHPGHS) with a 50 m vertical 32 mm nominal diameter U-bend ground heat exchanger. This system was designed and installed at the Solar Energy Institute, Ege University, Izmir, Turkey. Thermodynamic loss rate-to-capital cost ratios are used to show that, for components and the overall system, a systematic correlation appears to exist between capital cost and exergy loss (total or internal), but not between capital cost and energy loss or external exergy loss. This correlation may imply that devices in successful air conditioning are configured so as to achieve an overall optimal design, by appropriately balancing the thermodynamic (exergy-based) and economic characteristics of the overall system and its devices. The results may, (i) provide useful insights into the relations between thermodynamics and economics, both in general and for SAGSHPGHS (ii) help demonstrate the merits of second-law analysis. It is observed from the results that the maximum exergy destructions in the system particularly occur due to the electrical, mechanical and isentropic efficiencies and emphasize the need for paying close attention to the selection of this type of equipment, since components of inferior performance can considerably reduce the overall performance of the system. In conjunction with this, the total exergy losses values are obtained to be from 0.010 kW to 0.480 kW for the system. As expected, the largest energy and exergy losses occur in the greenhouse and compressor. The ratio of thermodynamic loss rate to capital cost values are obtained for a range from 0.035 to 1.125

  19. Fabrication of three 2500-watt (thermal) strontium-90 heat sources

    International Nuclear Information System (INIS)

    DeVore, J.R.; Haff, K.W.; Tompkins, J.A.

    1986-08-01

    Three 2500-watt (thermal) heat sources were fabricated by the Oak Ridge National Laboratory (ORNL) for the purpose of fueling a 500-watt (electric) thermoelectric generator as part of the US Department of Energy's Byproducts Utilization Program (BUP). Each of the sources, which are the largest ever assembled, consist of hot-pressed pellets of 90 Sr fluoride, doubly encapsulated in three Haynes-25 inner capsules and in a Hastelloy-S outer capsule. The total 90 Sr inventory of all three sources is 1.12 million curies. The sources were fabricated at the ORNL Fission Product Development Laboratory (FPDL), which is a facility that is capable of processing multi-megacurie quantities of radioactive materials, chiefly 137 Cs and 90 Sr. The source was tested to determine compliance with all of the IAEA Safety Series No. 33 requirements. The source fabrication, assembly, and testing are described in the presentation

  20. Discussion on application of water source heat pump technology to uranium mines

    International Nuclear Information System (INIS)

    An Qiang

    2011-01-01

    Application of water source heat pump units in recovering waste heat from uranium mines is discussed, and several forms of waste heat recovery are introduced. The problems in the application of water source heat pump technology are analyzed. Analysis results show that the water source heat pump technology has broad application prospects in uranium mines, and it is a way to exchange existing structure of heat and cold sources in uranium mines. (authors)

  1. Ground Source Heat Pump Sub-Slab Heat Exchange Loop Performance in a Cold Climate

    Energy Technology Data Exchange (ETDEWEB)

    Mittereder, N.; Poerschke, A.

    2013-11-01

    This report presents a cold-climate project that examines an alternative approach to ground source heat pump (GSHP) ground loop design. The innovative ground loop design is an attempt to reduce the installed cost of the ground loop heat exchange portion of the system by containing the entire ground loop within the excavated location beneath the basement slab. Prior to the installation and operation of the sub-slab heat exchanger, energy modeling using TRNSYS software and concurrent design efforts were performed to determine the size and orientation of the system. One key parameter in the design is the installation of the GSHP in a low-load home, which considerably reduces the needed capacity of the ground loop heat exchanger. This report analyzes data from two cooling seasons and one heating season. Upon completion of the monitoring phase, measurements revealed that the initial TRNSYS simulated horizontal sub-slab ground loop heat exchanger fluid temperatures and heat transfer rates differed from the measured values. To determine the cause of this discrepancy, an updated model was developed utilizing a new TRNSYS subroutine for simulating sub-slab heat exchangers. Measurements of fluid temperature, soil temperature, and heat transfer were used to validate the updated model.

  2. Effect of the Presence of Semi-circular Cylinders on Heat Transfer From Heat Sources Placed in Two Dimensional Channel

    Directory of Open Access Journals (Sweden)

    Ahmed W. Mustava

    2013-04-01

    Full Text Available The effect of a semi-circular cylinders in a two dimensional channel on heat transfer by forced convection from two heat sources with a constant temperature has been studied numerically. Each channel contains two heat sources; one on the upper surface of the channel and the other on the lower surface of the channel. There is semi-circular cylinder under the source in upper surface and there is semi-circular cylinder above the source in lower surface. The location of the second heat source with its semi-cylinder has been changed and keeps the first source with its semi- cylinder at the same location. The flow and temperature field are studied numerically with different values of Reynolds numbers and for different spacing between the centers of the semi-cylinders. The laminar flow field is analyzed numerically by solving the steady forms of the two-dimensional incompressible Navier- Stokes and energy equations.  The Cartesian velocity components and pressure on a collocated (non-staggered grid are used as dependent variables in the momentum equations, which discretized by finite volume method, body fitted coordinates are used to represent the complex channel geometry accurately, and grid generation technique based on elliptic partial differential equations is employed. SIMPLE algorithm is used to adjust the velocity field to satisfy the conservation of mass.  The range of Reynolds number is (Re= 100 – 800 and the range of the spacing between the semi-cylinders is(1-4 and the Prandtl number is 0.7.The results showed that increasing the spacing between the semi-cylinders increases the average of Nusselt number of the first heat source for all Reynolds numbers. As well as the results show that the best case among the cases studied to enhance the heat transfer is when the second heat source and its semi-cylinder located on at the distance (S=1.5 from the first half of the cylinder and the Reynolds number is greater than (Re ≥ 400 because of the

  3. Ground Source Heat Pump Sub-Slab Heat Exchange Loop Performance in a Cold Climate

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-11-01

    This report presents a cold-climate project that examines an alternative approach to ground source heat pump (GSHP) ground loop design. The innovative ground loop design is an attempt to reduce the installed cost of the ground loop heat exchange portion of the system by containing the entire ground loop within the excavated location beneath the basement slab. Prior to the installation and operation of the sub-slab heat exchanger, energy modeling using TRNSYS software and concurrent design efforts were performed to determine the size and orientation of the system. One key parameter in the design is the installation of the GSHP in a low-load home, which considerably reduces the needed capacity of the ground loop heat exchanger. This report analyzes data from two cooling seasons and one heating season.

  4. Self-Heating Effects In Polysilicon Source Gated Transistors

    Science.gov (United States)

    Sporea, R. A.; Burridge, T.; Silva, S. R. P.

    2015-01-01

    Source-gated transistors (SGTs) are thin-film devices which rely on a potential barrier at the source to achieve high gain, tolerance to fabrication variability, and low series voltage drop, relevant to a multitude of energy-efficient, large-area, cost effective applications. The current through the reverse-biased source barrier has a potentially high positive temperature coefficient, which may lead to undesirable thermal runaway effects and even device failure through self-heating. Using numerical simulations we show that, even in highly thermally-confined scenarios and at high current levels, self-heating is insufficient to compromise device integrity. Performance is minimally affected through a modest increase in output conductance, which may limit the maximum attainable gain. Measurements on polysilicon devices confirm the simulated results, with even smaller penalties in performance, largely due to improved heat dissipation through metal contacts. We conclude that SGTs can be reliably used for high gain, power efficient analog and digital circuits without significant performance impact due to self-heating. This further demonstrates the robustness of SGTs. PMID:26351099

  5. Measured Performance of a Low Temperature Air Source Heat Pump

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, R. K. [Johnson Research LLC, Pueblo West, CO (United States)

    2013-09-01

    A 4-ton Low Temperature Heat Pump (LTHP) manufactured by Hallowell International was installed in a residence near New Haven, Connecticut and monitored over two winters of operation. After attending to some significant service issues, the heat pump operated as designed. This report should be considered a review of the dual compressor 'boosted heat pump' technology. The Low Temperature Heat Pumpsystem operates with four increasing levels of capacity (heat output) as the outdoor temperature drops. The system was shown to select capacity correctly, supplying the appropriate amount of heat to the house across the full range of outdoor temperatures. The system's Coefficient of Performance (Seasonal COP, or SCOP) over two entire winters was calculated, based on measured data, to be 3.29over the first winter and 2.68 over the second winter. A second seasonal efficiency calculation by a different method yielded a SCOP of 2.78 for the first winter and 2.83 for the second winter. This second seasonal efficiency calculation was determined by comparing measured heat pump energy use to the in situ energy use with resistance heat alone. This method is the ratio of the slopes of thedaily energy use load lines.

  6. Radioactive heat source and method of making same

    International Nuclear Information System (INIS)

    Elsner, N.B.

    1977-01-01

    A radioactive source of heat which is resistant to cremation conditions is made by encapsulating a radioisotope within a containment vessel and forming a refractory metal silicide diffusion coating exterior thereof. A secondary molybdenum vessel may be provided with a molybdenum silicide coating and then heated in air to oxidize its outer layer. A layer is applied exterior of the diffusion-coating which provides a continuous ceramic oxide layer upon subjection to cremation. This outer layer may be discrete silica carried in a hardenable binder of an organic polymer, and a minor amount of antimony is preferably also included

  7. Promising design options for the encapsulated nuclear heat source reactor

    Energy Technology Data Exchange (ETDEWEB)

    Conway, L.; Carelli, M.D.; Dzodzo, M. [Westinghouse Science and Technology, Pittsburgh, PA (United States); Hossain, Q.; Brown, N.W. [Lawrence Livermore National Lab., CA (United States); Wade, D.C.; Sienick, J.J. [Argonne National Lab., IL (United States); Greenspan, E.; Kastenberg, W.E.; Saphier, D. [University of California Dept of Nuclear Engineering, Berkeley, CA (United States)

    2001-07-01

    Promising design options for the Encapsulated Nuclear Heat Source (ENHS) liquid-metal cooled fast reactor were identified during the first year of the DOE NERI program sponsored feasibility study. Many opportunities for incorporation of innovations in design and fabrication were identified. Three of the innovations are hereby described: a novel IHX (intermediate heat exchanger) made of a relatively small number of rectangular channels, an ENHS module design featuring 100% natural circulation, and a novel conceptual design of core support and fuelling. As a result of the first year study the ENHS concept appears more practical and more promising than perceived at the outset of this study. (authors)

  8. Promising design options for the encapsulated nuclear heat source reactor

    International Nuclear Information System (INIS)

    Conway, L.; Carelli, M.D.; Dzodzo, M.; Hossain, Q.; Brown, N.W.; Wade, D.C.; Sienick, J.J.; Greenspan, E.; Kastenberg, W.E.; Saphier, D.

    2001-01-01

    Promising design options for the Encapsulated Nuclear Heat Source (ENHS) liquid-metal cooled fast reactor were identified during the first year of the DOE NERI program sponsored feasibility study. Many opportunities for incorporation of innovations in design and fabrication were identified. Three of the innovations are hereby described: a novel IHX (intermediate heat exchanger) made of a relatively small number of rectangular channels, an ENHS module design featuring 100% natural circulation, and a novel conceptual design of core support and fuelling. As a result of the first year study the ENHS concept appears more practical and more promising than perceived at the outset of this study. (authors)

  9. Ground-source heat pump systems in Norway

    International Nuclear Information System (INIS)

    Stene, Joern

    2007-01-01

    The Norwegian ground source heat pump (GSHP) market is reviewed. Boreholes in bedrock are of growing interest for residential systems and of growing interest for larger systems with thermal recharging or thermal energy storage. Ground water is limited to areas where the water has acceptable purity. Challenges and important boundary conditions include 1) high quality GSHP system requires engineering expertise, 2) new building codes and EU directive 'energy performance of buildings.'(2006), and 3) hydronic floor heating systems in 50 percent of new residences (author) (ml)

  10. Heat pump using dual heat sources of air and water. Performance in cooling mode; Mizu kuki ryonetsugen heat pump no kenkyu. Reibo unten ni okeru seino

    Energy Technology Data Exchange (ETDEWEB)

    Ito, S; Miura, N [Kanagawa Institute of Technology, Kanagawa (Japan); Uchikawa, Y [Kubota Corp., Osaka (Japan)

    1997-11-25

    When a heat pump is used for cooling purpose, it is possible to utilize different kinds of waste water as high-heat sources. However, these heat sources would have their temperatures vary with seasons and time in a day. Therefore, a discussion was given on performance of a heat pump when water and air heat sources are used for condensers during cooling operation independently, in series and in parallel, respectively. The air condenser shows an equivalent COP as compared with the water condenser when air temperature is lower by about 8 degC than water temperature. At the same heat source temperature, the COP for the water condenser indicated a value higher by about 0.6 than the case of the air condenser. A method to use condensers in parallel experiences little contribution from the air heat source, and performance of the heat pump decreases below the case of using the water heat source independently when the air heat source temperature becomes higher than that of the water heat source. In the case of series use in which a water condenser is installed in front and an air condenser in rear, its effect is exhibited when temperature in the air heat source is lower than that in the water heat source. Better performance was shown than in operating the water heat source independently. 2 refs., 9 figs.

  11. Internal heat gain from different light sources in the building lighting systems

    Directory of Open Access Journals (Sweden)

    Suszanowicz Dariusz

    2017-01-01

    Full Text Available EU directives and the Construction Law have for some time required investors to report the energy consumption of buildings, and this has indeed caused low energy consumption buildings to proliferate. Of particular interest, internal heat gains from installed lighting affect the final energy consumption for heating of both public and residential buildings. This article presents the results of analyses of the electricity consumption and the luminous flux and the heat flux emitted by different types of light sources used in buildings. Incandescent light, halogen, compact fluorescent bulbs, and LED bulbs from various manufacturers were individually placed in a closed and isolated chamber, and the parameters for their functioning under identical conditions were recorded. The heat flux emitted by 1 W nominal power of each light source was determined. Based on the study results, the empirical coefficients of heat emission and energy efficiency ratios for different types of lighting sources (dependent lamp power and the light output were designated. In the heat balance of the building, the designated rates allow for precise determination of the internal heat gains coming from lighting systems using various light sources and also enable optimization of lighting systems of buildings that are used in different ways.

  12. Internal heat gain from different light sources in the building lighting systems

    Science.gov (United States)

    Suszanowicz, Dariusz

    2017-10-01

    EU directives and the Construction Law have for some time required investors to report the energy consumption of buildings, and this has indeed caused low energy consumption buildings to proliferate. Of particular interest, internal heat gains from installed lighting affect the final energy consumption for heating of both public and residential buildings. This article presents the results of analyses of the electricity consumption and the luminous flux and the heat flux emitted by different types of light sources used in buildings. Incandescent light, halogen, compact fluorescent bulbs, and LED bulbs from various manufacturers were individually placed in a closed and isolated chamber, and the parameters for their functioning under identical conditions were recorded. The heat flux emitted by 1 W nominal power of each light source was determined. Based on the study results, the empirical coefficients of heat emission and energy efficiency ratios for different types of lighting sources (dependent lamp power and the light output) were designated. In the heat balance of the building, the designated rates allow for precise determination of the internal heat gains coming from lighting systems using various light sources and also enable optimization of lighting systems of buildings that are used in different ways.

  13. Design and qualification testing of a strontium-90 fluoride heat source

    International Nuclear Information System (INIS)

    Fullam, H.T.

    1981-12-01

    The Strontium Heat Source Development Program began at the Pacific Northwest Laboratory (PNL) in 1972 and is scheduled to be completed by the end of FY-1981. The program is currently funded by the US Department of Energy (DOE) By-Product Utilization Program. The primary objective of the program has been to develop the data and technology required to permit the licensing of power systems for terrestrial applications that utilize 90 SrF 2 -fueled radioisotope heat sources. A secondary objective of the program has been to design and qualification-test a general purpose 90 SrF 2 -fueled heat source. The effort expended in the design and testing of the heat source is described. Detailed information is included on: heat source design, licensing requirements, and qualification test requirements; the qualification test procedures; and the fabrication and testing of capsules of various materials. The results obtained in the qualification tests show that the outer capsule design proposed for the 90 SrF 2 heat source is capable of meeting current licensing requirements when Hastelloy S is used as the outer capsule material. The data also indicate that an outer capsule of Hastelloy C-4 would probably also meet licensing requirements, although Hastelloy S is the preferred material. Therefore, based on the results of this study, the general purpose 90 SrF 2 heat source will consist of a standard WESF Hastelloy C-276 inner capsule filled with 90 SrF 2 and a Hastelloy S outer capsule having a 2.375-in. inner diameter and 0.500-in. wall thickness. The end closures for this study, the general purpose 90 SrF 2 heat a Hastelloy S outer capsule having a 2.375-in. inner diameter and 0.500-in. wall thickness. The end closures for the outer capsule will utilize an interlocking joint design requiring a 0.1-in. penetration closure weld

  14. Quasiballistic heat removal from small sources studied from first principles

    Science.gov (United States)

    Vermeersch, Bjorn; Mingo, Natalio

    2018-01-01

    Heat sources whose characteristic dimension R is comparable to phonon mean free paths display thermal resistances that exceed conventional diffusive predictions. This has direct implications to (opto)electronics thermal management and phonon spectroscopy. Theoretical analyses have so far limited themselves to particular experimental configurations. Here, we build upon the multidimensional Boltzmann transport equation (BTE) to derive universal expressions for the apparent conductivity suppression S (R ) =κeff(R ) /κbulk experienced by radially symmetric 2D and 3D sources. In striking analogy to cross-plane heat conduction in thin films, a distinct quasiballistic regime emerges between ballistic (κeff˜R ) and diffusive (κeff≃κbulk ) asymptotes that displays a logarithmic dependence κeff˜ln(R ) in single crystals and fractional power dependence κeff˜R2 -α in alloys (with α the Lévy superdiffusion exponent). Analytical solutions and Monte Carlo simulations for spherical and circular heat sources in Si, GaAs, Si0.99Ge0.01 , and Si0.82Ge0.18 , all carried out from first principles, confirm the predicted generic tendencies. Contrary to the thin film case, common approximations like kinetic theory estimates κeff≃∑Sωgreyκω and modified Fourier temperature curves perform relatively poorly. Up to threefold deviations from the BTE solutions for sub-100 nm sources underline the need for rigorous treatment of multidimensional nondiffusive transport.

  15. Design of serially connected ammonia-water hybrid absorption-compression heat pumps for district heating with the utilisation of a geothermal heat source

    DEFF Research Database (Denmark)

    Jensen, Jonas Kjær; Ommen, Torben Schmidt; Markussen, Wiebke Brix

    2016-01-01

    District heating (DH) can reduce the primary energy consumption in urban areas with significant heat demands. The design of a serially connected ammonia-water hybrid absorption-compression heat pump system was investigated for operation in the Greater Copenhagen DH network in Denmark, in order...... to supply 7.2 MW heat at 85 °C utilizing a geothermal heat source at 73 °C. Both the heat source and heat sink experience a large temperature change over the heat transfer process, of which a significant part may be achieved by direct heat exchange. First a generic study with a simple representation...

  16. Thermodynamic analysis on an instantaneous water heating system of shower wastewater source heat pump

    Directory of Open Access Journals (Sweden)

    Yuguo Wu

    2018-09-01

    Full Text Available Water reuse and desalination systems are energy intensive processes, and their increasing use is leading energy consumption within water systems to be an increasingly important issue. Shower wastewater contains large amounts of heat, so there is an opportunity to recover energy from shower water to offset energy consumption elsewhere in water systems. This paper found ways to increase the output of hot water and lower the energy consumption by establishing a thermodynamic model of an instantaneous wastewater source heat pump. The system proved to be very effective, the heating COP (coefficient of performance can reach 3.3 even in the winter. Under the conditions of limited heat transfer area, reducing the suction pressure of a compressor is a more feasible way to increase the hot water output to meet the needs of users rather than increasing the discharge pressure. Besides, increasing the heat transfer area of the evaporator is a more effective option. When the heat transfer area of evaporator varies from 0.5 to 1.0 square meters, a notable change is that the heating COP increases from 3.283 to 3.936. The heating COP in a system with a recuperator can reach 5.672, almost double that compared to the original systems.

  17. Performance analysis of air source heat pump system for office building

    Energy Technology Data Exchange (ETDEWEB)

    Han, Dong Won; KIm, Yong Chan [Korea University, Seoul (Korea, Republic of); Chang, Young Soo [School of Mechanical System Engineering, Kookmin University, Seoul (Korea, Republic of)

    2016-11-15

    In this study, the performance of an air source heat pump system installed in a commercial building is analyzed using the developed heat pump performance model and building load simulation data of several regions in Korea. The performance test of an air source heat pump system with a variable speed compressor is tested to develop model that considers changes in the performance characteristics of the heat pump system under various operating conditions. The heat pump system is installed in an environmental chamber, and the experimental equipment is set up according to the manufacturer' specifications as well as the AHRI 1230 test specifications. The performance test conditions of the heat pump system are selected using a central composite design method, in which 29 points for each cooling and heating mode are selected. The developed performance model based on experimental data predicts experimental values with an error of ±5 %. Building cooling and heating loads in three regions in Korea are analyzed using TRNSYS software, which includes standard building and weather data from Seoul, Daejeon and Busan in Korea. The effects of outdoor air temperature and part load ratio on the performance and regional monthly average power consumption of the heat pump system are analyzed.

  18. Advanced control for ground source heat pump systems

    Energy Technology Data Exchange (ETDEWEB)

    Hughes, Patrick [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Gehl, Anthony C. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Liu, Xiaobing [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2017-09-01

    Ground source heat pumps (GSHP), also known as geothermal heat pumps (GHP), are proven advanced HVAC systems that utilize clean and renewable geothermal energy, as well as the massive thermal storage capacity of the ground, to provide space conditioning and water heating for both residential and commercial buildings. GSHPs have higher energy efficiencies than conventional HVAC systems. It is estimated, if GSHPs achieve a 10% market share in the US, in each year, 0.6 Quad Btu primary energy consumption can be saved and 36 million tons carbon emissions can be avoided (Liu et al. 2017). However, the current market share of GSHPs is less than 1%. The foremost barrier preventing wider adoption of GSHPs is their high installation costs. To enable wider adoption of GSHPs, the costeffectiveness of GSHP applications must be improved.

  19. The impact of municipal waste combustion in small heat sources

    Science.gov (United States)

    Vantúch, Martin; Kaduchová, Katarína; Lenhard, Richard

    2016-06-01

    At present there is a tendency to make greater use for heating houses for burning solid fuel, such as pieces of wood, coal, coke, local sources of heat to burn natural gas. This tendency is given both the high price of natural gas as well as the availability of cheaper solid fuel. In many cases, in the context saving heating costs, respectively in the context of the disposal of waste is co-incinerated with municipal solid fuels and wastes of different composition. This co entails increased production emissions such as CO (carbon monoxide), NOx (nitrogen oxides), particulate matter (particulate matter), PM10, HCl (hydrogen chloride), PCDD/F (polychlorinated dibenzodioxins and dibenzofurans), PCBs (polychlorinated biphenyls) and others. The experiment was focused on the emission factors from the combustion of fossil fuels in combination with municipal waste in conventional boilers designed to burn solid fuel.

  20. Development of an Air-Source Heat Pump Integrated with a Water Heating / Dehumidification Module

    Energy Technology Data Exchange (ETDEWEB)

    Rice, C Keith [ORNL; Uselton, Robert B. [Lennox Industries, Inc; Shen, Bo [ORNL; Baxter, Van D [ORNL; Shrestha, Som S [ORNL

    2014-01-01

    A residential-sized dual air-source integrated heat pump (AS-IHP) concept is under development in partnership between ORNL and a manufacturer. The concept design consists of a two-stage air-source heat pump (ASHP) coupled on the air distribution side with a separate novel water heating/dehumidification (WH/DH) module. The motivation for this unusual equipment combination is the forecast trend for home sensible loads to be reduced more than latent loads. Integration of water heating with a space dehumidification cycle addresses humidity control while performing double-duty. This approach can be applied to retrofit/upgrade applications as well as new construction. A WH/DH module capable of ~1.47 L/h water removal and ~2 kW water heating capacity was assembled by the manufacturer. A heat pump system model was used to guide the controls design; lab testing was conducted and used to calibrate the models. Performance maps were generated and used in a TRNSYS sub-hourly simulation to predict annual performance in a well-insulated house. Annual HVAC/WH energy savings of ~35% are predicted in cold and hot-humid U.S. climates compared to a minimum efficiency baseline.

  1. North Village Ground Source Heat Pump Demonstration Project

    Energy Technology Data Exchange (ETDEWEB)

    Redderson, Jeff

    2015-08-03

    This project demonstrated the feasibility of converting from a traditional direct exchange system to a ground source heat pump system on a large scale, multiple building apartment complex on a university campus. A total of ten apartment buildings were converted using vertical well fields and a ground source loop that connected the 24 apartments in each building into a common system. The system has yielded significant operational savings in both energy and maintenance and transformed the living environments of these residential buildings for our students.

  2. Heat source component development program, October 1977--February 1978

    International Nuclear Information System (INIS)

    1978-03-01

    The General Purpose Heat Source (GPHS) is being developed by Los Alamos Scientific Laboratory (LASL) for the Department of Energy (DOE) Division of Nuclear Research and Application (DNRA). The first mission scheduled for the GPHS is the NASA Out-of-Ecliptic Flight in January, 1983. During the current reporting period (October--December, 1977, January--February, 1978), activities in this task were conducted as follows: (1) documentation of results of the reentry thermal, ablation, and thermal stress analyses of the conceptual designs; (2) identification and completion of modifications to the thermal and ablation models used to determine the performance response of the heat source modules during reentry; (3) initiation of modifications to the thermal stress model used to determine the performance response of heat source modules during reentry; (4) completion and documentation of the surface chemistry experiments; (5) initiation and completion of activities in support of LASL to define test plans for the trial design phase of the GPHS development program; (6) participation in the GPHS design review meeting held at DOE/Germantown, Maryland, December 19--20, 1977; and (7) initiation of the thermal analysis of Trial Design 1.1

  3. Towards a Future of District Heating Systems with Low-Temperature Operation together with Non-Fossil Fuel Heat Sources

    DEFF Research Database (Denmark)

    Tol, Hakan; Dinçer, Ibrahim; Svendsen, Svend

    2012-01-01

    This study focused on investigation of non-fossil fuel heat sources to be supplied to low-energy district heating systems operating in low temperature such as 55 C and 25 C in terms of, respectively, supply and return. Vast variety of heat sources classed in categories such as fossil fuel...

  4. Recuperator with microjet technology as a proposal for heat recovery from low-temperature sources

    Directory of Open Access Journals (Sweden)

    Wajs Jan

    2015-12-01

    Full Text Available A tendency to increase the importance of so-called dispersed generation, based on the local energy sources and the working systems utilizing both the fossil fuels and the renewable energy resources is observed nowadays. Generation of electricity on industrial or domestic scale together with production of heat can be obtained for example through employment of the ORC systems. It is mentioned in the EU directive 2012/27/EU for cogenerative production of heat and electricity. For such systems the crucial points are connected with the heat exchangers, which should be small in size but be able to transfer high heat fluxes. In presented paper the prototype microjet heat exchanger dedicated for heat recovery systems is introduced. Its novel construction is described together with the systematical experimental analysis of heat transfer and flow characteristics. Reported results showed high values of the overall heat transfer coefficient and slight increase in the pressure drop. The results of microjet heat exchanger were compared with the results of commercially available compact plate heat exchanger.

  5. Recuperator with microjet technology as a proposal for heat recovery from low-temperature sources

    Science.gov (United States)

    Wajs, Jan; Mikielewicz, Dariusz; Fornalik-Wajs, Elżbieta; Bajor, Michał

    2015-12-01

    A tendency to increase the importance of so-called dispersed generation, based on the local energy sources and the working systems utilizing both the fossil fuels and the renewable energy resources is observed nowadays. Generation of electricity on industrial or domestic scale together with production of heat can be obtained for example through employment of the ORC systems. It is mentioned in the EU directive 2012/27/EU for cogenerative production of heat and electricity. For such systems the crucial points are connected with the heat exchangers, which should be small in size but be able to transfer high heat fluxes. In presented paper the prototype microjet heat exchanger dedicated for heat recovery systems is introduced. Its novel construction is described together with the systematical experimental analysis of heat transfer and flow characteristics. Reported results showed high values of the overall heat transfer coefficient and slight increase in the pressure drop. The results of microjet heat exchanger were compared with the results of commercially available compact plate heat exchanger.

  6. A new energy analysis tool for ground source heat pump systems

    Energy Technology Data Exchange (ETDEWEB)

    Michopoulos, A.; Kyriakis, N. [Process Equipment Design Laboratory, Mechanical Engineering Department, Aristotle University of Thessaloniki, POB 487, 541 24 Thessaloniki (Greece)

    2009-09-15

    A new tool, suitable for energy analysis of vertical ground source heat pump systems, is presented. The tool is based on analytical equations describing the heat exchanged with the ground, developed in Matlab {sup registered} environment. The time step of the simulation can be freely chosen by the user (e.g. 1, 2 h etc.) and the calculation time required is very short. The heating and cooling loads of the building, at the afore mentioned time step, are needed as input, along with the thermophysical properties of the soil and of the ground heat exchanger, the operation characteristic curves of the system's heat pumps and the basic ground source heat exchanger dimensions. The results include the electricity consumption of the system and the heat absorbed from or rejected to the ground. The efficiency of the tool is verified through comparison with actual electricity consumption data collected from an existing large scale ground coupled heat pump installation over a three-year period. (author)

  7. Heat sources for heat pumps in the energetic and economic comparison; Waermequellen fuer Waermepumpen im energetischen und wirtschaftlichen Vergleich

    Energy Technology Data Exchange (ETDEWEB)

    Bockelmann, Franziska; Fisch, M. Norbert; Schlosser, Mathias; Peter, Markus [Technische Univ. Braunschweig (Germany). Inst. fuer Gebaeude- und Solartechnik

    2016-07-01

    Because of the growing application of heat pumps also the number of potentially usable low-temperature heat sources and corresponding heat exchangers for heat-pump systems present in the market increases. Thereby products like energy fences, high-power piles, ore ice reservoir come into applications without any knowledge ab out their power or the cost-profit ratio. The optimized lay-out of the coupling to the building are however essential conditions in order to reach an energy-efficient and durable operation of the facilities. The research project ''future heat pump'' sponsored by the BMWi is dedicated to the energetic and economic evaluation of heat sources for heat pumps. In this connection a pre-check-tool for the preliminary selection of low-temperature heat sources and connected, suitable heat-exchange systems is developed and their actual status of development presented. The holistic, comparing consideration of the different heat sources and heat-exchanger systems is related among others to the power numbers of the heat pumps, the entry and withdrawal services of the heat-exchangers, and the general performance of the systems. Additionally an estimation of economic and ecologic aspects (investment and operation costs, CO{sub 2} emissions) is made. Aim is the determination of the plausibility of applications and essential boundary conditions of single source systems. For the qualitative comparison in a project-accompanying monitoring different facilities and source systems are measurement-technically comprehended.

  8. Heat transfer within a concrete slab with a finite microwave heating source

    International Nuclear Information System (INIS)

    Lagos, L.E.; Li, W.; Ebadian, M.A.; Grubb, R.G.

    1995-01-01

    In the present paper, the concrete decontamination and decommissioning process with a finite microwave heating source is investigated theoretically. For the microwave induced heating pattern, a multilayer concrete slab, which includes steel reinforcement mesh, is assumed to be exposed to a finite plane microwave source at normal incidence. Two-dimensional heat transport within the concrete is also considered to evaluate the variations of temperature with heating time at different frequencies with and without the presence of the reinforcement bars. Four commonly used industrial microwave frequencies of 0.896, 2.45, 10.6 and 18.0 GHz have been selected. The results revealed that as the microwave frequency increases to, or higher than 10.6 GHz, the maximum temperature shifts toward the front surface of the concrete. It was found that the presence of a steel reinforcement mesh causes part of the microwave energy to be blocked and reflected. Furthermore, it was observed that the temperature distribution is nearly uniform within the dimensions of the microwave applicator for a high microwave power intensity and a short heating time. (author)

  9. Accelerator based continuous neutron source.

    CERN Document Server

    Shapiro, S M; Ruggiero, A G

    2003-01-01

    Until the last decade, most neutron experiments have been performed at steady-state, reactor-based sources. Recently, however, pulsed spallation sources have been shown to be very useful in a wide range of neutron studies. A major review of neutron sources in the US was conducted by a committee chaired by Nobel laureate Prof. W. Kohn: ''Neutron Sources for America's Future-BESAC Panel on Neutron Sources 1/93''. This distinguished panel concluded that steady state and pulsed sources are complementary and that the nation has need for both to maintain a balanced neutron research program. The report recommended that both a new reactor and a spallation source be built. This complementarity is recognized worldwide. The conclusion of this report is that a new continuous neutron source is needed for the second decade of the 20 year plan to replace aging US research reactors and close the US neutron gap. it is based on spallation production of neutrons using a high power continuous superconducting linac to generate pr...

  10. Hybrid ground-source heat pump system with active air source regeneration

    International Nuclear Information System (INIS)

    Allaerts, K.; Coomans, M.; Salenbien, R.

    2015-01-01

    Highlights: • A hybrid ground source heat pump system with two separate borefields is modelled. • The maximum underground storage temperature depends on the size of the drycooler. • Drycooler selection curves are given as function of underground storage temperature. • The size of the cold storage is reduced with 47% in the cost optimal configuration. • The cooling seasonal performance factor decreases with reduced storage capacity. - Abstract: Ground-source heat pump systems (GSHP) offer great advantages over traditional heating and cooling installations. However, their applications are limited due to the high initial costs of borehole drilling. One way to avoid these costs is by reducing the size of the borefield, e.g. by combining the system with other renewable energy sources or by using active regeneration to increase the system efficiency. In this paper a hybrid ground-source heat pump system (HGSHP) is analyzed. The borefield is split into a warm part and a cold part, which allows for seasonal thermal-energy storage. Additionally, supplementary drycoolers capture heat during summer and cold during winter. The relationship between the underground storage size and temperature and the drycooler capacity is described, using an office building in Flanders (Belgium) as reference case. Results show that with a HGSHP system a significant borefield size reduction can be achieved without compromising system performance; i.e. for the reference case a reduction of 47% was achieved in the cost-optimal configuration. It is also shown that the cooling seasonal performance factor decreases significantly with underground storage capacity. In addition, the HGSHP can be used to maintain or restore thermal balance in the geothermal source when heating and cooling loads do not match

  11. Ground-source heat pump case studies and utility programs

    Energy Technology Data Exchange (ETDEWEB)

    Lienau, P.J.; Boyd, T.L.; Rogers, R.L.

    1995-04-01

    Ground-source heat pump systems are one of the promising new energy technologies that has shown rapid increase in usage over the past ten years in the United States. These systems offer substantial benefits to consumers and utilities in energy (kWh) and demand (kW) savings. The purpose of this study was to determine what existing monitored data was available mainly from electric utilities on heat pump performance, energy savings and demand reduction for residential, school and commercial building applications. In order to verify the performance, information was collected for 253 case studies from mainly utilities throughout the United States. The case studies were compiled into a database. The database was organized into general information, system information, ground system information, system performance, and additional information. Information was developed on the status of demand-side management of ground-source heat pump programs for about 60 electric utility and rural electric cooperatives on marketing, incentive programs, barriers to market penetration, number units installed in service area, and benefits.

  12. Testing of PCM Heat Storage Modules with Solar Collectors as Heat Source

    DEFF Research Database (Denmark)

    Englmair, Gerald; Dannemand, Mark; Johansen, Jakob Berg

    2016-01-01

    A latent heat storage based on the phase change material Sodium Acetate Trihydrate (SAT) has been tested as part of a demonstration system. The full heat storage consisted of 4 individual modules each containing about 200 kg of sodium acetate trihydrate with different additives. The aim...... was to actively utilize the ability of the material to supercool to obtain long storage periods. The modules were charged with solar heat supplied by 22.4 m2 evacuated tubular collectors. The investigation showed that it was possible to fully charge one module within a period of 270 minutes with clear skies...

  13. Numerical method of identification of an unknown source term in a heat equation

    Directory of Open Access Journals (Sweden)

    Fatullayev Afet Golayo?lu

    2002-01-01

    Full Text Available A numerical procedure for an inverse problem of identification of an unknown source in a heat equation is presented. Approach of proposed method is to approximate unknown function by polygons linear pieces which are determined consecutively from the solution of minimization problem based on the overspecified data. Numerical examples are presented.

  14. Electron beam welding of iridium heat source capsules

    International Nuclear Information System (INIS)

    Mustaleski, T.M.; Yearwood, J.C.; Burgan, C.E.; Green, L.A.

    1991-01-01

    The development of the welding procedures for the production of DOP-26 iridium alloy cups for heat source encapsulation is described. All the final assembly welds were made using the electron beam welding process. The welding of the 0.13-mm weld shield required the use of computer controlled X-Y table and a run-off tab. Welding of the frit vent to the cup required that a laser weld be made to hold the frit assembly edges together for the final electron beam weld. Great care is required in tooling design and beam placement to achieve acceptable results. Unsuccessful attempts to use laser beam welding for heat shield butt weld are discussed

  15. HTGR nuclear heat source component design and experience

    International Nuclear Information System (INIS)

    Peinado, C.O.; Wunderlich, R.G.; Simon, W.A.

    1982-05-01

    The high-temperature gas-cooled reactor (HTGR) nuclear heat source components have been under design and development since the mid-1950's. Two power plants have been designed, constructed, and operated: the Peach Bottom Atomic Power Station and the Fort St. Vrain Nuclear Generating Station. Recently, development has focused on the primary system components for a 2240-MW(t) steam cycle HTGR capable of generating about 900 MW(e) electric power or alternately producing high-grade steam and cogenerating electric power. These components include the steam generators, core auxiliary heat exchangers, primary and auxiliary circulators, reactor internals, and thermal barrier system. A discussion of the design and operating experience of these components is included

  16. Self-optimizing control of air-source heat pump with multivariable extremum seeking

    International Nuclear Information System (INIS)

    Dong, Liujia; Li, Yaoyu; Mu, Baojie; Xiao, Yan

    2015-01-01

    The air-source heat pump (ASHP) is widely adopted for cooling and heating of residential and commercial buildings. The performance of ASHP can be controlled by several operating variables, such as compressor capacity, condenser fan speed, evaporator fan speed and suction superheat. In practice, the system characteristics can be varied significantly by the variations in ambient condition, operation setpoint, internal thermal load and equipment degradation, which makes it difficult to obtain accurate plant models. As consequence, the model based control strategies for ASHP could limit the achievable energy efficiency. Model-free self-optimizing control strategies are thus more preferable. In this study, a multi-input extremum seeking control (ESC) scheme is proposed for both heating and cooling operation of ASHP. The zone temperature is assumed to be regulated by the compressor capacity, while the expansion valve opening is used to regulate the suction superheat at the given setpoint. The total power consumption of the compressor, the condenser fan and the evaporator fan is measured as input to the ESC, while the ESC controls the evaporator fan speed, the condenser fan speed and the suction superheat setpoint. The proposed scheme is evaluated with a Modelica based dynamic simulation model of ASHP under both cooling and heating modes of operation. Simulation results show the effectiveness of the proposed scheme to achieve the maximum achievable efficiency in a nearly model-free manner. - Highlights: • Multi-input ESC. • Air-source heat pump. • Cooling and heating. • Modelica based model

  17. Quality assurance program plan for FRG sealed isotopic heat sources project (C-229)

    International Nuclear Information System (INIS)

    Tanke, J.M.

    1997-01-01

    This QAPP implements the Quality Assurance Program Plan for the FRG Sealed Isotopic Heat Sources Project (C-229). The heat source will be relocated from the 324 Building and placed in interim storage at the Central Waste Complex (CWC)

  18. Air source integrated heat pump simulation model for EnergyPlus

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Bo; New, Joshua; Baxter, Van

    2017-12-01

    An Air Source Integrated Heat Pump (AS-IHP) is an air source, multi-functional spacing conditioning unit with water heating function (WH), which can lead to great energy savings by recovering the condensing waste heat for domestic water heating. This paper summarizes development of the EnergyPlus AS-IHP model, introducing the physics, sub-models, working modes, and control logic. Based on the model, building energy simulations were conducted to demonstrate greater than 50% annual energy savings, in comparison to a baseline heat pump with electric water heater, over 10 US cities, using the EnergyPlus quick-service restaurant template building. We assessed water heating energy saving potentials using AS-IHP versus both gas and electric baseline systems, and pointed out climate zones where AS-IHPs are promising. In addition, a grid integration strategy was investigated to reveal further energy saving and electricity cost reduction potentials, via increasing the water heating set point temperature during off-peak hours and using larger water tanks.

  19. General-purpose heat source development. Phase II: conceptual designs

    International Nuclear Information System (INIS)

    Snow, E.C.; Zocher, R.W.; Grinberg, I.M.; Hulbert, L.E.

    1978-11-01

    Basic geometric module shapes and fuel arrays were studied to determine how well they could be expected to meet the General Purpose Heat Source (GPHS) design requirements. Seven conceptual designs were selected, detailed drawings produced, and these seven concepts analyzed. Three of these design concepts were selected as GPHS Trial Designs to be reanalyzed in more detail and tested. The geometric studies leading to the selection of the seven conceptual designs, the analyses of these designs, and the selection of the three trial designs are discussed

  20. Estimation of heat transfer and heat source in a molten pool

    Energy Technology Data Exchange (ETDEWEB)

    Yun, J.I.; Suh, K.Y.; Kang, C.S. [Seoul National Univ., Dept. of Nuclear Engineering (Korea, Republic of)

    2001-07-01

    Heat transfer and fluid flow in a molten pool are influenced by internal volumetric heat generated from the radioactive decay of fission product species retained in the pool. The pool superheat is determined based on the overall energy balance that equates the heat production rate to the heat loss rate. Decay heat of fission products in the pool was estimated by product of the mass concentration and energy conversion factor of each fission product. For the calculation of heat generation rate in the pool, twenty-nine (29) elements were chosen and classified by their chemical properties. The mass concentration of a fission product is obtained from released fraction and the tabular output of the ORIGEN 2 code. The initial core and pool inventories at each time can also be estimated using ORIGEN 2. The released fraction of each fission product is calculated based on the bubble dynamics and mass transport. Numerical analysis was performed for the TMI-2 accident. The pool is assumed to be a partially filled hemispherical geometry, 1.45 m in radius and 32,700 kg in mass. The change of pool geometry during the numerical calculation was neglected. The peak temperature sizably decreased by about 60 K as the fission products were released from the pool. (author)

  1. Estimation of heat transfer and heat source in a molten pool

    International Nuclear Information System (INIS)

    Yun, J.I.; Suh, K.Y.; Kang, C.S.

    2001-01-01

    Heat transfer and fluid flow in a molten pool are influenced by internal volumetric heat generated from the radioactive decay of fission product species retained in the pool. The pool superheat is determined based on the overall energy balance that equates the heat production rate to the heat loss rate. Decay heat of fission products in the pool was estimated by product of the mass concentration and energy conversion factor of each fission product. For the calculation of heat generation rate in the pool, twenty-nine (29) elements were chosen and classified by their chemical properties. The mass concentration of a fission product is obtained from released fraction and the tabular output of the ORIGEN 2 code. The initial core and pool inventories at each time can also be estimated using ORIGEN 2. The released fraction of each fission product is calculated based on the bubble dynamics and mass transport. Numerical analysis was performed for the TMI-2 accident. The pool is assumed to be a partially filled hemispherical geometry, 1.45 m in radius and 32,700 kg in mass. The change of pool geometry during the numerical calculation was neglected. The peak temperature sizably decreased by about 60 K as the fission products were released from the pool. (author)

  2. Whole planet cooling and the radiogenic heat source contents of the earth and moon

    International Nuclear Information System (INIS)

    Schubert, G.; Stevenson, D.

    1980-01-01

    It is widely believed that the surface heat flows of the earth and moon provide good measures of the total amounts of radioactives in these bodies. Simple thermal evolution models, based on subsolidus whole mantle convection, indicate that this may not be the case. These models have been constructed assuming an initially hot state, but with a wide variety of choices for the parameters characterizing the rheology and convective vigor. All models are constrained to be consistent with present-day surface heat fluxes, and many of the terrestrial models are consistent with the mantle viscosities indicated by post-glacial rebound. For the earth the acceptable models give a radiogenic heat production that is only 65--85% of the surface heat output, the difference being due to secular cooling of the earth (about 50 0 --100 0 C per 10 9 years in the upper mantle). It is argued that the actual heat generation may be substantially less, since the models omit core heat, upward migration of heat sources, possible layering of the mantle, and deviations from steady convection. Geochemical models which are near to chondritic (apart from potassium depletion) are marginally consistent with surface heat flow. In the lunar models, heat generation is typically only 70--80% of the surface heat flow, even with allowance for the strong near-surface enhancement of radioactives. Despite the simplicity of the models the persistence of a significant difference between heat generation and heat output for a wide range of parameter choices indicates that this difference is real and should be incorporated in geochemical modeling of the planets

  3. 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.

  4. Integrated Temperature Sensors based on Heat Diffusion

    NARCIS (Netherlands)

    Van Vroonhoven, C.P.L.

    2015-01-01

    This thesis describes the theory, design and implementation of a new class of integrated temperature sensors, based on heat diffusion. In such sensors, temperature is sensed by measuring the time it takes for heat to diffuse through silicon. An on-chip thermal delay can be determined by geometry and

  5. Natural convection heat transfer in a rectangular pool with volumetric heat sources

    International Nuclear Information System (INIS)

    Lee, Seung Dong; Lee, Kang Hee; Suh, Kune Y.

    2003-01-01

    Natural convection plays an important role in determining the thermal load from debris accumulated in the reactor vessel lower head during a severe accident. The heat transfer within the molten core material can be characterized by buoyancy-induced flows resulting from internal heating due to decay of fission products. The thermo-fluid dynamic characteristics of the molten pool depend strongly on the thermal boundary conditions. The spatial and temporal variation of heat flux on the pool wall boundaries and the pool superheat are mainly characterized by the natural convection flow inside the molten pool. In general, natural convection involving internal heat generation is delineated in terms of the modified Rayleigh number, Ra', which quantifies the internal heat source and hence the strength of buoyancy. The test section is of rectangular cavity whose length, width, and height are 500 mm, 80 mm, and 250 mm, respectively. A total of twenty-four T-type thermocouples were installed in the test loop to measure temperature distribution. Four T-type thermocouples were utilized to measure temperatures on the boundary. A direct heating method was adopted in this test to simulate the uniform heat generation. The experiments covered a range of Rayleigh number, Ra, between 4.87x10 7 and 2.32x10 14 and Prandtl number, Pr, between 0.7 and 3.98. Tests were conducted with water and air as simulant. The upper and lower boundary conditions were maintained at a uniform temperature of 10degC. (author)

  6. Ground source heat pump performance in case of high humidity soil and yearly balanced heat transfer

    International Nuclear Information System (INIS)

    Schibuola, Luigi; Tambani, Chiara; Zarrella, Angelo; Scarpa, Massimiliano

    2013-01-01

    Highlights: • GSHPs are simulated in case of humid soil and yearly balanced heat transfer. • Humid soil and yearly balanced heat transfer imply higher compactness of GSHPs. • Resulting GSHPs are compared with other traditional and innovative HVAC systems. • GSHPs score best, especially in case of inverter-driven compressors. - Abstract: Ground source heat pump (GSHP) systems are spreading also in Southern Europe, due to their high energy efficiency both in heating and in cooling mode. Moreover, they are particularly suitable in historical cities because of difficulties in the integration of heating/cooling systems into buildings subjected to historical preservation regulations. In these cases, GSHP systems, especially the ones provided with borehole heat exchangers, are a suitable solution instead of gas boilers, air-cooled chillers or cooling towers. In humid soils, GSHP systems are even more interesting because of their enhanced performance due to higher values of soil thermal conductivity and capacity. In this paper, GSHP systems operating under these boundary conditions are analyzed through a specific case study set in Venice and related to the restoration of an historical building. With this analysis the relevant influences of soil thermal conductivity and yearly balanced heat transfer in the design of the borehole field are shown. In particular, the paper shows the possibility to achieve higher compactness of the borehole field footprint area when yearly balanced heat transfer in the borehole field is expected. Then, the second set of results contained in the paper shows how GSHP systems designed for high humidity soils and yearly balanced heat loads at the ground side, even if characterized by a compact footprint area, may still ensure better performance than other available and more common technologies such as boilers, air-cooled chillers, chillers coupled with cooling towers and heat pumps and chillers coupled with lagoon water. As a consequence

  7. Heat buffers improve capacity and exploitation degree of geothermal energy sources

    NARCIS (Netherlands)

    Ooster, A.van t; Wit, J. de; Janssen, E.G.O.N.; Ruigrok, J.

    2008-01-01

    This research focuses on the role of heat buffers to support optimal use of combinations of traditional and renewable heat sources like geothermal heat for greenhouse heating. The objective was to determine the contribution of heat buffers to effective new combinations of resources that satisfy

  8. Novel edible oil sources: Microwave heating and chemical properties.

    Science.gov (United States)

    Hashemi, Seyed Mohammad Bagher; Mousavi Khaneghah, Amin; Koubaa, Mohamed; Lopez-Cervantes, Jaime; Yousefabad, Seyed Hossein Asadi; Hosseini, Seyedeh Fatemeh; Karimi, Masoumeh; Motazedian, Azam; Asadifard, Samira

    2017-02-01

    The aim of this work was to investigate the effect of various microwave heating times (1, 3, 5, 10, and 15min) on the chemical properties of novel edible oil sources, including Mashhadi melon (Cucumis melo var. Iranians cv. Mashhadi), Iranian watermelon (Citrullus lanatus cv. Fire Fon), pumpkin (Cucurbita pepo subsp. pepo var. Styriaca), and yellow apple (Malus domestica cv. Golden Delicious) seed oils. The evaluated parameters were peroxide value (PV), conjugated diene (CD) and triene (CT) values, carbonyl value (CV), p-anisidine value (AnV), oil stability index (OSI), radical scavenging activity (RSA), total tocopherols, total phenolics, as well as chlorophyll and carotenoid contents. Results showed that extended microwave heating involves decreased quality of the seed oils, mainly due to the formation of primary and secondary oxidation products. Microwave heating time also affects the total contents of chlorophylls, carotenoids, phenolics and tocopherols, which clearly decrease by increasing the exposure time. The order of oxidative stability of the analyzed edible oils was pumpkin>Mashhadi melon>Iranian watermelon>yellow apple. The obtained results demonstrated the promising potential of these novel edible oils for different food applications. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Operational Performance Characterization of a Heat Pump System Utilizing Recycled Water as Heat Sink and Heat Source in a Cool and Dry Climate

    Directory of Open Access Journals (Sweden)

    Piljae Im

    2018-01-01

    Full Text Available The wastewater leaving from homes and businesses contains abundant low-grade energy, which can be utilized through heat pump technology to heat and cool buildings. Although the energy in the wastewater has been successfully utilized to condition buildings in other countries, it is barely utilized in the United States, until recently. In 2013, the Denver Museum of Nature & Science at Denver, the United States implemented a unique heat pump system that utilizes recycled wastewater from a municipal water system to cool and heat its 13,000 m2 new addition. This recycled water heat pump (RWHP system uses seven 105 kW (cooling capacity modular water-to-water heat pumps (WWHPs. Each WWHP uses R-410A refrigerant, has two compressors, and can independently provide either 52 °C hot water (HW or 7 °C chilled water (CHW to the building. This paper presents performance characterization results of this RWHP system based on the measured data from December 2014 through August 2015. The annual energy consumption of the RWHP system was also calculated and compared with that of a baseline Heating, Ventilation, and Air Conditioning (HVAC system which meets the minimum energy efficiencies that are allowed by American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE 90.1-2013. The performance analysis results indicate that recycled water temperatures were favorable for effective operation of heat pumps. As a result, on an annual basis, the RWHP system avoided 50% of source energy consumption (resulting from reduction in natural gas consumption although electricity consumption was increased slightly, reduced CO2 emissions by 41%, and saved 34% in energy costs as compared with the baseline system.

  10. Simulation and analysis on thermodynamic performance of surface water source heat pump system

    Institute of Scientific and Technical Information of China (English)

    Nan Lv; Qing Zhang; Zhenqian Chen; Dongsheng Wu

    2017-01-01

    This work established a thermodynamic performance model of a heat pump system containing a heat pump unit model, an air conditioning cooling and heating load calculation model, a heat exchanger model and a water pump performance model based on mass and energy balances. The thermodynamic performance of a surface water source heat pump air conditioning system was simulated and verified by comparing the simulation results to an actual engineering project. In addition, the effects of the surface water temperature, heat exchanger structure and surface water pipeline transportation system on the thermodynamic performance of the heat pump air conditioning system were analyzed. Under the simulated conditions in this paper with a cooling load of 3400 kW, the results showed that a 1 ℃ decrease in the surface water temperature leads to a 2.3 percent increase in the coefficient of performance; furthermore, an additional 100 m of length for the closed-loop surface water heat exchanger tube leads to a 0.08 percent increase in the coefficient of performance. To decrease the system energy consumption, the optimal working point should be specified according to the surface water transportation length.

  11. Heat pump using dual heat sources of air and water. Performance with heat sources arranged in parallel; Mizu kuki ryonetsugen heat pump no kenkyu. Netsugen heiretsu unten ni okeru seino

    Energy Technology Data Exchange (ETDEWEB)

    Ito, S; Miura, N; Sato, S [Kanagawa Institute of Technology, Kanagawa (Japan); Uchikawa, Y; Hamada, K [Kubota Corp., Osaka (Japan)

    1996-10-27

    A heat pump system using water and air as heat sources was built and evaluated for its performance. In this system, evaporators may be operated singly or as connected in parallel or series, and, for each case, the quantity of heat acquired may be measured and system performance may be quantitatively evaluated. The findings follow. When the two heat sources are equal in temperature in the single-evaporator operation, the evaporation temperature is about 7{degree}C higher on the water side than on the air side, and the performance coefficient is about 0.7 higher. When the air heat source temperature is 25{degree}C in the parallel operation, like quantities of heat are obtained from both heat sources, and collection of heat from the water increases with a decrease in the air heat source temperature but, with an increase, collection from the air increases. When the air heat source temperature decreases, the evaporation temperature decreases in the single-evaporator working on the air and in the parallel operation but it levels off in the single-evaporator working on the water alone. When the water heat source temperature decreases, evaporation temperature drop is sharper in the single-evaporator working on the water than in the parallel operation, which suggests the transfer from the parallel operation to the single-evaporator working on the air. In the single-evaporator operation on the water heat source, the evaporation temperature linearly decreases with an increase in superheating. 1 ref., 10 figs.

  12. Hydrogen and renewable energy sources integrated system for greenhouse heating

    Directory of Open Access Journals (Sweden)

    Ileana Blanco

    2013-09-01

    Full Text Available A research is under development at the Department of Agro- Environmental Sciences of the University of Bari “Aldo Moro” in order to investigate the suitable solutions of a power system based on solar energy (photovoltaic and hydrogen, integrated with a geothermal heat pump for powering a self sustained heated greenhouse. The electrical energy for heat pump operation is provided by a purpose-built array of solar photovoltaic modules, which supplies also a water electrolyser system controlled by embedded pc; the generated dry hydrogen gas is conserved in suitable pressured storage tank. The hydrogen is used to produce electricity in a fuel cell in order to meet the above mentioned heat pump power demand when the photovoltaic system is inactive during winter night-time or the solar radiation level is insufficient to meet the electrical demand. The present work reports some theoretical and observed data about the electrolyzer operation. Indeed the electrolyzer has required particular attention because during the experimental tests it did not show a stable operation and it was registered a performance not properly consistent with the predicted performance by means of the theoretical study.

  13. 3D simulation of Heat transfer in MEMS-based microchannel

    International Nuclear Information System (INIS)

    Choi, Chi Woong; Huh, Cheol; Kim, Dong Eok; Kim, Moo Hwan

    2007-01-01

    The microchannel heat sink is promising heat dissipation method for high heat flux source. Contrary to conventional circular channel, MEMS based microchannel had rectangular or trapezoidal cross-sectional shape. In our study, we conducted three dimensional conjugate heat transfer calculation for rectangular shape microchannel. First, we simulated that channel was completely drained with known heating power. As a result we obtained calibration line, which indicates heat loss was function of temperature. Second, we simulated single phase heat transfer with various mass flux, 100-400 kg/m 2 s. In conclusion, the single phase test verified that the present heat loss evaluation method is applicable to micro scale heat transfer devices. Heat fluxes from each side wall shows difference due to non-uniform heating. However those ratios were correlated with supplied total heat. Finally, we proposed effective area correction factor to evaluate appropriate heat flux

  14. Moving heat source in a confined channel: Heat transfer and boiling in endovenous laser ablation of varicose veins

    NARCIS (Netherlands)

    de Boer, Amit; Oliveira, Jorge L. G.; van der Geld, Cees W. M.; Malskat, Wendy S. J.; van den Bos, Renate; Nijsten, Tamar; van Gemert, Martin J. C.

    2017-01-01

    Motion of a moving laser light heat source in a confined volume has important applications such as in endovenous laser ablation (EVLA) of varicose veins. This light heats up the fluid and the wall volume by absorption and heat conduction. The present study compares the flow and temperature fields in

  15. Heat input properties of hollow cathode arc as a welding heat source

    International Nuclear Information System (INIS)

    Nishikawa, Hiroshi; Shobako, Shinichiro; Ohta, Masashi; Ohji, Takayoshi

    2005-01-01

    In order to clarify whether a hollow cathode arc (HCA) can be used as a welding heat source in space, investigations into the fundamental characteristics of HCA were experimentally performed under low pressure conditions. The HCA method enables an arc discharge to ignite and maintain under low pressure conditions; in contrast, low pressure conditions make it extremely difficult for the conventional gas tungsten arc method to form an arc discharge. In an earlier paper, it was shown that the melting process by HCA is very sensitive to process parameters such as the gas flow rate and arc length, and a deep penetration forms when the arc length is long and the gas flow rate is low. In this paper, the distribution of the arc current on the anode surface and the plasma properties of the HCA under low pressure conditions have been made clear and the total heat energy to the anode has been discussed in order to understand the heat input properties of the HCA. The result shows that the HCA in the case of a low gas flow rate is a high and concentrated energy source, and the high energy input to the anode contributes to the deep penetration

  16. Microinstallations Based on Renewable Energy Sources in the Construction Sector

    Science.gov (United States)

    Kurzak, Lucjan

    2017-10-01

    The focus of this paper is on the status and prognoses of the use of microinstallations based on renewable energy sources to supply heat and power. The technologies that have been important in Europe and Poland for microgeneration of electricity include photovoltaic systems, micro wind turbines and co-generation systems. Solar collectors, heat pumps and biomass have also been used to generate heat. Microinstallations for renewable energy sources represent the initial point and the foundation for the development of micro networks, intelligent networks and the whole prosumer energy sector.

  17. Tabulation of Fundamental Assembly Heat and Radiation Source Files

    International Nuclear Information System (INIS)

    T. deBues; J.C. Ryman

    2006-01-01

    The purpose of this calculation is to tabulate a set of computer files for use as input to the WPLOAD thermal loading software. These files contain details regarding heat and radiation from pressurized water reactor (PWR) assemblies and boiling water reactor (BWR) assemblies. The scope of this calculation is limited to rearranging and reducing the existing file information into a more streamlined set of tables for use as input to WPLOAD. The electronic source term files used as input to this calculation were generated from the output files of the SAS2H/ORIGIN-S sequence of the SCALE Version 4.3 modular code system, as documented in References 2.1.1 and 2.1.2, and are included in Attachment II

  18. Advanced neutron source design: burnout heat flux correlation development

    International Nuclear Information System (INIS)

    Gambill, W.R.; Mochizuki, T.

    1988-01-01

    In the advanced neutron source reactor (ANSR) fuel element region, heat fluxes will be elevated. Early designs corresponded to average and estimated hot-spot fluxes of 11 to 12 and 21 to 22 MW/m 2 , respectively. Design changes under consideration may lower these values to ∼ 9 and 17 MW/m 1 . In either event, the development of a satisfactory burnout heat flux correlation is an important element among the many thermal-hydraulic design issues, since the critical power ratio will depend in part on its validity. Relatively little work in the area of subcooled-flow burnout has been published over the past 12 yr. The authors have compared seven burnout correlations and modifications therefore with several sets of experimental data, of which the most relevant to the ANS core are those referenced. The best overall agreement between the correlations tested and these data is currently provided by a modification of Thorgerson et al. correlation. The variable ranges of the experimental data are outlined and the results of the correlation comparisons are summarized

  19. Nonlinear radiative heat flux and heat source/sink on entropy generation minimization rate

    Science.gov (United States)

    Hayat, T.; Khan, M. Waleed Ahmed; Khan, M. Ijaz; Alsaedi, A.

    2018-06-01

    Entropy generation minimization in nonlinear radiative mixed convective flow towards a variable thicked surface is addressed. Entropy generation for momentum and temperature is carried out. The source for this flow analysis is stretching velocity of sheet. Transformations are used to reduce system of partial differential equations into ordinary ones. Total entropy generation rate is determined. Series solutions for the zeroth and mth order deformation systems are computed. Domain of convergence for obtained solutions is identified. Velocity, temperature and concentration fields are plotted and interpreted. Entropy equation is studied through nonlinear mixed convection and radiative heat flux. Velocity and temperature gradients are discussed through graphs. Meaningful results are concluded in the final remarks.

  20. Conversion to biofuel based heating systems - local environmental effects

    International Nuclear Information System (INIS)

    Jonsson, Anna

    2003-01-01

    One of the most serious environmental problems today is the global warming, i.e.climate changes caused by emissions of greenhouse gases. The greenhouse gases originate from combustion of fossil fuels and changes the atmospheric composition. As a result of the climate change, the Swedish government has decided to make a changeover of the Swedish energy system. This involves an increase of the supply of electricity and heating from renewable energy sources and a decrease in the amount electricity used for heating, as well as a more efficient use of the existing electricity system. Today, a rather large amount electricity is used for heating in Sweden. Furthermore, nuclear power will be phased out by the year 2010 in Sweden. Bio fuels are a renewable energy source and a conceivable alternative to the use of fossil fuels. Therefore, an increase of bio fuels will be seen the coming years. Bio fuels have a lot of environmental advantages, mainly for the global environment, but might also cause negative impacts such as depletion of the soils where the biomass is grown and local deterioration of the air quality where the bio fuels are combusted. These negative impacts are a result of the use of wrong techniques and a lack of knowledge and these factors have to be improved if the increase of the use of bio fuels is to be made effectively. The aim of this master thesis is to evaluate the possibilities for heating with bio fuel based systems in housing areas in the municipalities of Trollhaettan, Ulricehamn and Goetene in Vaestra Goetalands County in the South West of Sweden and to investigate which environmental and health effects are caused by the conversion of heating systems. The objective is to use the case studies as examples on preferable bio fuel based heating systems in different areas, and to what environmental impact this conversion of heating systems might cause. The housing areas for this study have been chosen on the basis of present heating system, one area

  1. Optimal operating conditions of a transcritical endoreversible cycle using a low enthalpy heat source

    International Nuclear Information System (INIS)

    Rachedi, Malika; Feidt, Michel; Amirat, Madjid; Merzouk, Mustapha

    2016-01-01

    Highlights: • Thermodynamics analysis of a finite size heat engine driven by a finite heat source. • Mathematical modelling of a transcritical endoreversible organic Rankine cycle. • Parametric study of the optimum operating conditions of transcritical cycle. • Choice of appropriate parameters could lead to very promising efficiencies. - Abstract: In the context of thermodynamic analysis of finite dimensions systems, we studied the optimum operating conditions of an endoreversible thermal machine. In this study, we considered a transcritical cycle, considering external irreversibilities. The hot reservoir is a low enthalpy geothermal heat source; therefore, it is assumed to be finite, whereas the cold reservoir is assumed to be infinite. The power optimisation is investigated by searching the optimum effectiveness of the heat-exchanger at the hot side of the engine. The sum of the total effectiveness and the second law of thermodynamics are used as constraints for optimisation. The optimal temperatures of the working fluid and optimum performances are evaluated based on the most significant parameters of the system: (1) the ratio of heat capacity rate of the working fluid to the heat capacity rate of the coolant and (2) the ratio of the sink temperature to the temperature of the hot source. The parametric study of the cycle and its approximation by a trilateral cycle enabled us to determine the optimum value of the effectiveness of the heat exchangers and the optimal operating temperatures of the cycle considered. The efficiencies obtained are in the range of 15–25% and was found to exceed the efficiency expected by the Curzon and Ahlborn prevision; meanwhile, the Carnot efficiency remains at a high limit.

  2. Lunar base heat pump, phase 1

    Science.gov (United States)

    Goldman, Jeffrey H.; Harvey, A.; Lovell, T.; Walker, David H.

    1994-01-01

    This report describes the Phase 1 process and analysis used to select a refrigerant and thermodynamic cycle as the basis of a vapor compression heat pump requiring a high temperature lift, then to perform a preliminary design to implement the selected concept, including major component selection. Use of a vapor compression heat pump versus other types was based on prior work performed for the Electric Power Research Institute. A high lift heat pump is needed to enable a thermal control system to remove heat down to 275 K from a habitable volume when the external thermal environment is severe. For example, a long-term lunar base habitat will reject heat from a space radiator to a 325 K environment. The first step in the selection process was to perform an optimization trade study, quantifying the effect of radiator operating temperature and heat pump efficiency on total system mass; then, select the radiator operating temperature corresponding to the lowest system mass. Total system mass included radiators, all heat pump components, and the power supply system. The study showed that lunar night operation, with no temperature lift, dictated the radiator size. To operate otherwise would require a high mass penalty to store power. With the defined radiation surface, and heat pump performances assumed to be from 40 percent to 60 percent of the Carnot ideal, the optimum heat rejection temperature ranged from 387 K to 377 K, as a function of heat pump performance. Refrigerant and thermodynamic cycles were then selected to best meet the previously determined design conditions. The system was then adapted as a ground-based prototype lifting temperature to 360 K (versus 385 K for flight unit) and using readily available commercial-grade components. Over 40 refrigerants, separated into wet and dry compression behavioral types, were considered in the selection process. Refrigerants were initially screened for acceptable critical temperature. The acceptable refrigerants were

  3. The effect of location of a convective heat source on displacement ventilation: CFD study

    Energy Technology Data Exchange (ETDEWEB)

    Park, H.J.; Holland, D. [Dunham Associates, Inc., Minneapolis, MN (United States). Advanced Technologies Group

    2001-08-01

    Two-dimensional computational simulations are performed to examine the effect of vertical location of a convective heat source on thermal displacement ventilation systems. In this study, a heat source is modeled with seven different heights from the floor (0.5, 0.75, 1.0, 1.25, 1.5, 1.75, 2.0 m) in a displacement ventilation environment. The flow and temperature fields in thermal displacement ventilation systems vary depending on the location of the heat source. As the heat source rises, the convective heat gain from the heat source to an occupied zone becomes less significant. This effect changes the temperature field and results in the reduction of the cooling load in the occupied zone. The stratification level is also affected by the heat source location at a given flow rate. (author)

  4. Optimal design of district heating and cooling pipe network of seawater-source heat pump

    Energy Technology Data Exchange (ETDEWEB)

    Li, Xiang-li; Duanmu, Lin; Shu, Hai-wen [School of Civil and Hydraulic Engineering, Dalian University of Technology, Dalian, Liaoning Province 116024 (China)

    2010-01-15

    The district heating and cooling (DHC) system of a seawater-source heat pump is large system engineering. The investments and the operational cost of DHC pipe network are higher than a tradition system. Traditional design methods only satisfy the needs of the technology but dissatisfy the needs of the economy, which not only waste a mass of money but also bring problems to the operation, the maintenance and the management. So we build a least-annualized-cost global optimal mathematic model that comprises all constrict conditions. Furthermore, this model considers the variety of heating load and cooling load, the operational adjustment in different periods of the year. Genetic algorithm (GA) is used to obtain the optimal combinations of discrete diameters. Some operators of GA are selected to reduce the calculation time and obtain good calculation accuracy. This optimal method is used to the design of the DHC network of Xinghai Bay commercial district which is a real engineering. The design optimization can avoid the matter of the hydraulic unbalance of the system, enhance the running efficiency and greatly reduce the annualized-cost comparing with the traditional design method. (author)

  5. The heat source of Ruapehu crater lake; deductions from the energy and mass balances

    Science.gov (United States)

    Hurst, A. W.; Bibby, H. M.; Scott, B. J.; McGuinness, M. J.

    1991-05-01

    Regular observations of temperature, outflow rates and water chemistry of Crater Lake, Mt. Ruapehu, New Zealand have been made for the last 25 years. These data have been used to derive a model of the dynamics of the lake, and determine the input of energy, mass, and chloride from the volcano to the Crater Lake. The recent, relatively quiescent state of the volcano, when virtually no heat has been input to the lake, has also enabled an assessment to be made of the surface heat loss characteristics, which play an important role in the model of the lake. The modelling suggests that since about 1982 the ratio of the volcanic heat to mass added to the base of the lake is about 6 MJ/kg, which is not compatible with heating of the lake by magmatic steam alone. Thus, only about 50% of the heating has been by magmatic steam. It is suggested that heat could be transferred from a magmatic source to the region below the lake by a heat-pipe mechanism, commonly associated with geothermal systems. The simultaneous upward movement of vapour phase, and downward movement of liquid phase from condensed vapour allows efficient heat transfer without overall mass transfer. The permeability necessary to supply the required heat is of the order of 10 darcy, and is consistent with a rubble filled vent. For at least the last five years, there has been a characteristic pattern in the Crater Lake temperature record, with alternate heating and cooling phases. The heating phase generally lasts for one or two months, while the cooling phase lasts for six months to a year. A possible explanation for this cyclic behaviour is the presence of a layer of liquid sulphur under Crater Lake, acting as a partial barrier between the heat-pipe and the lake. The unusual variations of the viscosity of liquid sulphur with temperature will mean that at temperatures greater than 160°C, the layer of sulphur becomes highly viscous and would block any upwards steam flow and hence stop the heat input to Crater

  6. Measured Performance of a Low Temperature Air Source Heat Pump

    Energy Technology Data Exchange (ETDEWEB)

    R.K. Johnson

    2013-09-01

    A 4-ton Low Temperature Heat Pump (LTHP) manufactured by Hallowell International was installed in a residence near New Haven, Connecticut and monitored over two winters of operation. After attending to some significant service issues, the heat pump operated as designed. This report should be considered a review of the dual compressor “boosted heat pump” technology. The Low Temperature Heat Pump system operates with four increasing levels of capacity (heat output) as the outdoor temperature drops.

  7. Thermal-hydraulic process for cooling, heating and power production with low-grade heat sources in residential sector

    International Nuclear Information System (INIS)

    Borgogno, R.; Mauran, S.; Stitou, D.; Marck, G.

    2017-01-01

    Highlights: • Assessment of solar thermal-hydraulic process for tri-generation application. • Choice of the most suitable working fluid pair (R1234yf/R1233zd). • Evaluation of the global annual performance in Mediterranean climate. • Global annual COP and heat amplification achieving 0.24 and 1.2 respectively. • Global annual performance achieving an electric efficiency of 3.7%. - Abstract: A new process based on thermal-hydraulic conversion actuated by low-grade thermal energy is investigated. Input thermal energy can be provided by the means of solar collectors, as well as other low temperature energy sources. In the following article, “thermo-hydraulic” term refers to a process involving an incompressible fluid used as an intermediate medium to transfer work hydraulically between different thermal operated components or sub-systems. The system aims at providing trigeneration energy features for the residential sector, that is providing heating, cooling and electrical power for meeting the energy needs of domestic houses. This innovative system is made of two dithermal processes (working at two different levels of temperatures) and featuring two different working fluids. The first process is able to directly supply either electrical energy generated by an hydraulic turbine or drives the second process thanks to the incompressible fluid, which is similar to a heat pump effect for heating or cooling purposes. The innovative aspect of this process relies on the use of an hydraulic transfer fluid to transfer the work between each sub-system and therefore simplifying the conversion chain. A model, assuming steady-state operation, is developed to assess the energy performances of different variants of this thermo-hydraulic process with various heat source temperatures (80–110 °C) or heat sinks (0–30 °C), as well as various pairs of working fluids. For instance, in the frame of a single-family home, located in the Mediterranean region, the working

  8. Experimental study of enhancing heating performance of the air-source heat pump by using a novel heat recovery device designed for reusing the energy of the compressor shell

    International Nuclear Information System (INIS)

    Huang, Bi; Jian, Qifei; Luo, Lizhong; Zhao, Jing

    2017-01-01

    Highlights: • A novel heat recovery device was designed and tested. • Aiming at avoiding liquid slugging in cold areas. • Recovery of the waste energy of compressor housing. • Refrigerant is heated with the energy recovered before it is sucked into the compressor. • Requires no extra power while the recovery system is operating. - Abstract: A novel heat recovery device designed to recover the heat that is released from the outer surface of heat pump compressors, and to enhance the performance of heat pumps in cold areas was made and tested in this study. The novel heat recovery device consists of three fundamental units: a heat absorption unit, a heat emission unit and heat pipes. An amount of work focused on recovering the heat of compressors through oil system, but few studies concentrated on the housing. The main advantage of the heat recovery device is no need for extra energy consumption for its only driving force is the temperature difference between the compressor shell and the working fluid inside the suction line. The experimental results were obtained from a series of tests with a R410A air-source heat pump. Effects of the device are analyzed with respect of the suction temperature, temperature distribution among the housing, input power and exergy destruction. Moreover, the impact on the heating capacity is also discussed. Further, direction for improvement is also given based on the analysis.

  9. About the possible options for models of convective heat transfer in closed volumes with local heating source

    Directory of Open Access Journals (Sweden)

    Maksimov Vyacheslav I.

    2015-01-01

    Full Text Available Results of mathematical modeling of convective heat transfer in air area surrounded on all sides enclosing structures, in the presence of heat source at the lower boundary of the media are presented. Solved the system of differential equations of unsteady Navier-Stokes equations with the appropriate initial and boundary conditions. The process of convective heat transfer is calculated using the models of turbulence Prandtl and Prandtl-Reichard. Takes into account the processes of heat exchange region considered with the environment. Is carried out the analysis of the dimensionless heat transfer coefficient at interfaces “air – enclosures”. The distributions average along the gas temperature range are obtained.

  10. Performance analysis of low temperature heat source of organic Rankine cycle for geothermal application

    Science.gov (United States)

    Pintoro, A.; Ambarita, H.; Nur, T. B.; Napitupulu, F. H.

    2018-02-01

    Indonesia has a high potential energy resources from geothermal activities. Base on the report of Asian Development Bank and World Bank, the estimated of Indonesian hydrothermal geothermal resource considered to be the largest among the world. If it’s can be utilized to produce the electric power, it’s can contribute to increasing the electrification rates in Indonesia. In this study, an experimental studied of electric power generation, utilizing the Organic Rankine Cycle (ORC) system to convert the low level heat of hydrothermal as an energy source. The temperature of hydrothermal was modelled as hot water from water boiler which has a temperature range from 60 °C - 100 °C to heat up the organic working fluid of ORC system. The system can generated 1,337.7 watts of electricity when operated using R134A with hot water inlet temperature of 100 °C. Changing system working fluid to R245fa, the net power obtained increase to 1,908.9 watts with the same heat source condition. This study showed that the ORC system can be implemented to utilize low temperature heat source of hydrothermal in Indonesia.

  11. Nuclear and geothermal energy as a direct heat source

    International Nuclear Information System (INIS)

    Field, A.A.

    1976-01-01

    After some remarks on economic aspects, the swimming pool reactor simplified for the purpose of heat generation is described, the core of which supplies heat of 100-120 0 C for district heating. In this context, ways of storing waste heat are discussed. The alternative is pointed out that energy may be transferred by means of hydrogen. In conclusion, it is demonstrated on a French plant how geothermal water can be used directly via heat exchangers for district heating. (UA/LN) [de

  12. Application of sorption heat pumps for increasing of new power sources efficiency

    Science.gov (United States)

    Vasiliev, L.; Filatova, O.; Tsitovich, A.

    2010-07-01

    In the 21st century the way to increase the efficiency of new sources of energy is directly related with extended exploration of renewable energy. This modern tendency ensures the fuel economy needs to be realized with nature protection. The increasing of new power sources efficiency (cogeneration, trigeneration systems, fuel cells, photovoltaic systems) can be performed by application of solid sorption heat pumps, regrigerators, heat and cold accumulators, heat transformers, natural gas and hydrogen storage systems and efficient heat exchangers.

  13. Large heat storage tank for load management nd implementation of ambient heat. District heating networks based on combined heat and power; Grosswaermespeicher zum Lastmanagement und zur Einbindung von Umweltenergie. Auf KWK basierende Fernwaermenetze

    Energy Technology Data Exchange (ETDEWEB)

    Gross, Sebastian; Rhein, Martin; Ruehling, Karin [Technische Universitaet Dresden (Germany). Inst. fuer Energietechnik

    2013-06-15

    The district heating based on combined heat and power is a transitional technology on the way to the supply of Germany with renewable energy. In the next years, this transitional technology can only be maintained and expanded when marketability is given. Therefore an appropriate combination has to be found from investment measures. Together with new aspects in the management strategy, these investment measures should significantly improve the marketability. The investment measures also aims to enable a primary energetic, appropriate combination of natural gas-based combined heat and power, renewable energy sources (solar thermal energy, ambient heat) and heat pump technology.

  14. Ground Source Heat Pumps vs. Conventional HVAC: A Comparison of Economic and Environmental Costs

    Science.gov (United States)

    2009-03-26

    of systems are surface water heat pumps (SWHPs), ground water heat pumps (GWHPs), and ground coupled heat pumps ( GCHPs ) (Kavanaugh & Rafferty, 1997...Kavanaugh & Rafferty, 1997). Ground Coupled Heat Pumps (Closed-Loop Ground Source Heat Pumps) GCHPs , otherwise known as closed-loop GSHPs, are the...Significant confusion has arisen through the use of GCHP and closed-loop GSHP terminology. Closed-loop GSHP is the preferred nomenclature for this

  15. local alternative sources for cogeneration combined heat and power system

    Science.gov (United States)

    Agll, Abdulhakim Amer

    Global demand for energy continues to grow while countries around the globe race to reduce their reliance on fossil fuels and greenhouse gas emissions by implementing policy measures and advancing technology. Sustainability has become an important issue in transportation and infrastructure development projects. While several agencies are trying to incorporate a range of sustainability measures in their goals and missions, only a few planning agencies have been able to implement these policies and they are far from perfect. The low rate of success in implementing sustainable policies is primarily due to incomplete understanding of the system and the interaction between various elements of the system. The conventional planning efforts focuses mainly on performance measures pertaining to the system and its impact on the environment but seldom on the social and economic impacts. The objective of this study is to use clean and alternative energy can be produced from many sources, and even use existing materials for energy generation. One such pathway is using wastewater, animal and organic waste, or landfills to create biogas for energy production. There are three tasks for this study. In topic one evaluated the energy saving that produced from combined hydrogen, heat, and power and mitigate greenhouse gas emissions by using local sustainable energy at the Missouri S&T campus to reduce energy consumption and fossil fuel usage. Second topic aimed to estimate energy recovery and power generation from alternative energy source by using Rankin steam cycle from municipal solid waste at Benghazi-Libya. And the last task is in progress. The results for topics one and two have been presented.

  16. Plasmonic photothermal heating of intraperitoneal tumors through the use of an implanted near-infrared source.

    Science.gov (United States)

    Bagley, Alexander F; Hill, Samuel; Rogers, Gary S; Bhatia, Sangeeta N

    2013-09-24

    Plasmonic nanomaterials including gold nanorods are effective agents for inducing heating in tumors. Because near-infrared (NIR) light has traditionally been delivered using extracorporeal sources, most applications of plasmonic photothermal therapy have focused on isolated subcutaneous tumors. For more complex models of disease such as advanced ovarian cancer, one of the primary barriers to gold nanorod-based strategies is the adequate delivery of NIR light to tumors located at varying depths within the body. To address this limitation, a series of implanted NIR illumination sources are described for the specific heating of gold nanorod-containing tissues. Through computational modeling and ex vivo studies, a candidate device is identified and validated in a model of orthotopic ovarian cancer. As the therapeutic, imaging, and diagnostic applications of plasmonic nanomaterials progress, effective methods for NIR light delivery to challenging anatomical regions will complement ongoing efforts to advance plasmonic photothermal therapy toward clinical use.

  17. Environmental assessment for the relocation and storage of isotopic heat sources, Hanford Site, Richland, Washington

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-06-01

    As part of a bilateral agreement between the Federal Minister for Research and Technology of the Federal Republic of Germany (FRG) and the DOE, Pacific Northwest National Laboratory (PNNL) developed processes for the treatment and immobilization of high-level radioactive waste. One element of this bilateral agreement was the production of sealed isotopic heat sources. During the mid-1980s, 30 sealed isotopic heat sources were manufactured. The sources contain a total of approximately 8.3 million curies consisting predominantly of cesium-137 and strontium-90 with trace amounts of transuranic contamination. Currently, the sources are stored in A-Cell of the 324 Building. Intense radiation fields from the sources are causing the cell windows and equipment to deteriorate. Originally, it was not intended to store the isotopic heat sources for this length of time in A-cell. The 34 isotopic heat sources are classified as remote handled transuranic wastes. Thirty-one of the isotopic heat sources are sealed, and seals on the three remaining isotopic heat sources have not been verified. However, a decision has been made to place the remaining three isotopic heat sources in the CASTOR cask(s). The Washington State Department of Health (WDOH) has concurred that isotopic heat sources with verified seals or those placed into CASTOR cask(s) can be considered sealed (no potential to emit radioactive air emissions) and are exempt from WAC Chapter 246-247, Radiation Protection-Air Emissions.

  18. Environmental assessment for the relocation and storage of isotopic heat sources, Hanford Site, Richland, Washington

    International Nuclear Information System (INIS)

    1997-06-01

    As part of a bilateral agreement between the Federal Minister for Research and Technology of the Federal Republic of Germany (FRG) and the DOE, Pacific Northwest National Laboratory (PNNL) developed processes for the treatment and immobilization of high-level radioactive waste. One element of this bilateral agreement was the production of sealed isotopic heat sources. During the mid-1980s, 30 sealed isotopic heat sources were manufactured. The sources contain a total of approximately 8.3 million curies consisting predominantly of cesium-137 and strontium-90 with trace amounts of transuranic contamination. Currently, the sources are stored in A-Cell of the 324 Building. Intense radiation fields from the sources are causing the cell windows and equipment to deteriorate. Originally, it was not intended to store the isotopic heat sources for this length of time in A-cell. The 34 isotopic heat sources are classified as remote handled transuranic wastes. Thirty-one of the isotopic heat sources are sealed, and seals on the three remaining isotopic heat sources have not been verified. However, a decision has been made to place the remaining three isotopic heat sources in the CASTOR cask(s). The Washington State Department of Health (WDOH) has concurred that isotopic heat sources with verified seals or those placed into CASTOR cask(s) can be considered sealed (no potential to emit radioactive air emissions) and are exempt from WAC Chapter 246-247, Radiation Protection-Air Emissions

  19. Experimental Study of the Performance of Air Source Heat Pump Systems Assisted by Low-Temperature Solar-Heated Water

    Directory of Open Access Journals (Sweden)

    Jinshun Wu

    2013-01-01

    Full Text Available Due to the low temperatures, the heating efficiency of air source heat pump systems during the winter is very low. To address this problem, a low-temperature solar hot water system was added to a basic air source heat pump system. Several parameters were tested and analyzed. The heat collection efficiency of the solar collector was analyzed under low-temperature conditions. The factors that affect the performance of the heat pumps, such as the fluid temperature, pressure, and energy savings, were analyzed for cases where the solar energy auxiliary heat pump and the air source heat pump are used independently. The optimal heating temperature and the changes in the fluid temperature were determined. The influence of the compression ratio and the coefficient of performance (COP were investigated theoretically. The results revealed the parameters that are important to the performance of the system. Several measures for improving the COP of the heat pump units are provided for other applications and future research.

  20. Heated probe diagnostic inside of the gas aggregation nanocluster source

    Science.gov (United States)

    Kolpakova, Anna; Shelemin, Artem; Kousal, Jaroslav; Kudrna, Pavel; Tichy, Milan; Biederman, Hynek; Surface; Plasma Science Team

    2016-09-01

    Gas aggregation cluster sources (GAS) usually operate outside common working conditions of most magnetrons and the size of nanoparticles created in GAS is below that commonly studied in dusty plasmas. Therefore, experimental data obtained inside the GAS are important for better understanding of process of nanoparticles formation. In order to study the conditions inside the gas aggregation chamber, special ``diagnostic GAS'' has been constructed. It allows simultaneous monitoring (or spatial profiling) by means of optical emission spectroscopy, mass spectrometry and probe diagnostic. Data obtained from Langmuir and heated probes map the plasma parameters in two dimensions - radial and axial. Titanium has been studied as an example of metal for which the reactive gas in the chamber starts nanoparticles production. Three basic situations were investigated: sputtering from clean titanium target in argon, sputtering from partially pre-oxidized target and sputtering with oxygen introduced into the discharge. It was found that during formation of nanoparticles the plasma parameters differ strongly from the situation without nanoparticles. These experimental data will support the efforts of more realistic modeling of the process. Czech Science Foundation 15-00863S.

  1. Dynamic Allocation of a Domestic Heating Task to Gas-Based and Heatpump-Based Heating Agents

    NARCIS (Netherlands)

    Treur, J.

    2013-01-01

    In this paper a multi-agent model for a domestic heating task is introduced and analysed. The model includes two alternative heating agents (for gas-based heating and for heatpump-based heating), and a third allocation agent which determines the most economic allocation of the heating task to these

  2. Linking potential heat source and sink to urban heat island: Heterogeneous effects of landscape pattern on land surface temperature.

    Science.gov (United States)

    Li, Weifeng; Cao, Qiwen; Lang, Kun; Wu, Jiansheng

    2017-05-15

    Rapid urbanization has significantly contributed to the development of urban heat island (UHI). Regulating landscape composition and configuration would help mitigate the UHI in megacities. Taking Shenzhen, China, as a case study area, we defined heat source and heat sink and identified strong and weak sources as well as strong and weak sinks according to the natural and socioeconomic factors influencing land surface temperature (LST). Thus, the potential thermal contributions of heat source and heat sink patches were differentiated. Then, the heterogeneous effects of landscape pattern on LST were examined by using semiparametric geographically weighted regression (SGWR) models. The results showed that landscape composition has more significant effects on thermal environment than configuration. For a strong source, the percentage of patches has a positive impact on LST. Additionally, when mosaicked with some heat sink, even a small improvement in the degree of dispersion of a strong source helps to alleviate UHI. For a weak source, the percentage and density of patches have positive impacts on LST. For a strong sink, the percentage, density, and degree of aggregation of patches have negative impacts on LST. The effects of edge density and patch shape complexity vary spatially with the fragmentation of a strong sink. Similarly, the impacts of a weak sink are mainly exerted via the characteristics of percent, density, and shape complexity of patches. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Radiation detector system having heat pipe based cooling

    Science.gov (United States)

    Iwanczyk, Jan S.; Saveliev, Valeri D.; Barkan, Shaul

    2006-10-31

    A radiation detector system having a heat pipe based cooling. The radiation detector system includes a radiation detector thermally coupled to a thermo electric cooler (TEC). The TEC cools down the radiation detector, whereby heat is generated by the TEC. A heat removal device dissipates the heat generated by the TEC to surrounding environment. A heat pipe has a first end thermally coupled to the TEC to receive the heat generated by the TEC, and a second end thermally coupled to the heat removal device. The heat pipe transfers the heat generated by the TEC from the first end to the second end to be removed by the heat removal device.

  4. Variable Conductance Heat Pipe Cooling of Stirling Convertor and General Purpose Heat Source

    Science.gov (United States)

    Tarau, Calin; Schwendeman, Carl; Anderson, William G.; Cornell, Peggy A.; Schifer, Nicholas A.

    2013-01-01

    In a Stirling Radioisotope Power System (RPS), heat must be continuously removed from the General Purpose Heat Source (GPHS) modules to maintain the modules and surrounding insulation at acceptable temperatures. The Stirling convertor normally provides this cooling. If the Stirling convertor stops in the current system, the insulation is designed to spoil, preventing damage to the GPHS at the cost of an early termination of the mission. An alkali-metal Variable Conductance Heat Pipe (VCHP) can be used to passively allow multiple stops and restarts of the Stirling convertor. In a previous NASA SBIR Program, Advanced Cooling Technologies, Inc. (ACT) developed a series of sodium VCHPs as backup cooling systems for Stirling RPS. The operation of these VCHPs was demonstrated using Stirling heater head simulators and GPHS simulators. In the most recent effort, a sodium VCHP with a stainless steel envelope was designed, fabricated and tested at NASA Glenn Research Center (GRC) with a Stirling convertor for two concepts; one for the Advanced Stirling Radioisotope Generator (ASRG) back up cooling system and one for the Long-lived Venus Lander thermal management system. The VCHP is designed to activate and remove heat from the stopped convertor at a 19 degC temperature increase from the nominal vapor temperature. The 19 degC temperature increase from nominal is low enough to avoid risking standard ASRG operation and spoiling of the Multi-Layer Insulation (MLI). In addition, the same backup cooling system can be applied to the Stirling convertor used for the refrigeration system of the Long-lived Venus Lander. The VCHP will allow the refrigeration system to: 1) rest during transit at a lower temperature than nominal; 2) pre-cool the modules to an even lower temperature before the entry in Venus atmosphere; 3) work at nominal temperature on Venus surface; 4) briefly stop multiple times on the Venus surface to allow scientific measurements. This paper presents the experimental

  5. An analysis of solar assisted ground source heat pumps in cold climates

    International Nuclear Information System (INIS)

    Emmi, Giuseppe; Zarrella, Angelo; De Carli, Michele; Galgaro, Antonio

    2015-01-01

    Highlights: • The work focuses on solar assisted ground source heat pump in cold climates. • Multi-year simulations of SAGSHP, are carried out in six cold locations. • GSHP and SAGSHP are compared. • The effect of total borehole length on the heat pump energy efficiency is studied. • A dedicated control strategy is used to manage both solar and ground loops. - Abstract: Exploiting renewable energy sources for air-conditioning has been extensively investigated over recent years, and many countries have been working to promote the use of renewable energy to decrease energy consumption and CO_2 emissions. Electrical heat pumps currently represent the most promising technology to reduce fossil fuel usage. While ground source heat pumps, which use free heat sources, have been taking significant steps forward and despite the fact that their energy performance is better than that of air source heat pumps, their development has been limited by their high initial investment cost. An alternative solution is one that uses solar thermal collectors coupled with a ground source heat pump in a so-called solar assisted ground source heat pump. A ground source heat pump system, used to heat environments located in a cold climate, was investigated in this study. The solar assisted ground source heat pump extracted heat from the ground by means of borehole heat exchangers and it injected excess solar thermal energy into the ground. Building load profiles are usually heating dominated in cold climates, but when common ground source heat pump systems are used only for heating, their performance decreases due to an unbalanced ground load. Solar thermal collectors can help to ensure that systems installed in cold zones perform more efficiently. Computer simulations using a Transient System Simulation (TRNSYS) tool were carried out in six cold locations in order to investigate solar assisted ground source heat pumps. The effect of the borehole length on the energy efficiency of

  6. Forecast of power generation and heat production from renewable energy sources

    Directory of Open Access Journals (Sweden)

    Pydych Tadeusz

    2017-01-01

    Full Text Available The share of renewable energy sources (RES in the end use of energy in the UE will increase from the present level of about 25% to 50 % in 2030 according to the assumptions of the European Commission. In Poland the RES Act was passed in 2015. The act defines mechanisms and instruments for supporting the production of electricity and heat from renewable energy sources. Statistics (2003–2014 of electricity generation and heat production from RES in Poland were used in the research. Because of amendments to regulations connected with promoting RES and the emissions trading system (ETS as well as the uncertainty associated with further directions of the energy and environmental policy, generation of electricity and heat based on the use of RES must be modelled while taking risk into account. A number of dynamic processes incorporating random events may be modelled by stochastic equations using Ito calculus. By applying Euler’s method to solve stochastic differential equations (SDE, it is possible to simulate the development of the use of renewable energy carriers in electricity generation and heat production in the future.

  7. Solar heating - a major source of renewable energy

    International Nuclear Information System (INIS)

    Bosselaar, L.

    2001-01-01

    Actions that can be taken to increase the uptake of technology for solar water heaters and solar buildings are discussed. An overview of existing technology covers solar water heating, solar buildings, space heating, solar cooling, solar drying, solar desalination. Solar water heating, solar buildings and solar crop drying are discussed individually under the sub-headings of (a) the technology; (b) the market; (c) potential; (d) economics and (e) market acceleration strategies. Other subjects discussed are market acceleration, main opportunities, R and D needs and conclusions. The IEA solar heating and solar cooling programme is described

  8. Climate Adaptivity and Field Test of the Space Heating Used Air-Source Transcritical CO2 Heat Pump

    Science.gov (United States)

    Song, Yulong; Ye, Zuliang; Cao, Feng

    2017-08-01

    In this study, an innovation of air-sourced transcritical CO2 heat pump which was employed in the space heating application was presented and discussed in order to solve the problem that the heating performances of the transcritical CO2 heat pump water heater deteriorated sharply with the augment in water feed temperature. An R134a cycle was adopted as a subcooling device in the proposed system. The prototype of the presented system was installed and supplied hot water for three places in northern China in winter. The field test results showed that the acceptable return water temperature can be increased up to 55°C, while the supply water temperature was raised rapidly by the presented prototype to up to 70°C directly, which was obviously appropriate to the various conditions of heating radiator in space heating application. Additionally, though the heating capacity and power dissipation decreased with the decline in ambient temperature or the augment in water temperature, the presented heat pump system performed efficiently whatever the climate and water feed temperature were. The real time COP of the presented system was generally more than 1.8 in the whole heating season, while the seasonal performance coefficient (SPC) was also appreciable, which signified that the economic efficiency of the presented system was more excellent than other space heating approaches such as fuel, gas, coal or electric boiler. As a result, the novel system will be a promising project to solve the energy issues in future space heating application.

  9. Thermoelectric Exhaust Heat Recovery with Heat Pipe-Based Thermal Control

    Science.gov (United States)

    Brito, F. P.; Martins, Jorge; Hançer, Esra; Antunes, Nuno; Gonçalves, L. M.

    2015-06-01

    Heat pipe (HP)-based heat exchangers can be used for very low resistance heat transfer between a hot and a cold source. Their operating temperature depends solely on the boiling point of their working fluid, so it is possible to control the heat transfer temperature if the pressure of the HP can be adjusted. This is the case of the variable conductance HPs (VCHP). This solution makes VCHPs ideal for the passive control of thermoelectric generator (TEG) temperature levels. The present work assesses, both theoretically and experimentally, the merit of the aforementioned approach. A thermal and electrical model of a TEG with VCHP assist is proposed. Experimental results obtained with a proof of concept prototype attached to a small single-cylinder engine are presented and used to validate the model. It was found that the HP heat exchanger indeed enables the TEG to operate at a constant, optimal temperature in a passive and safe way, and with a minimal overall thermal resistance, under part load, it effectively reduces the active module area without deprecating the temperature level of the active modules.

  10. Encapsulated nuclear heat source reactors for energy security

    International Nuclear Information System (INIS)

    Greenspan, E.; Susplugas, A.; Hong, S.G.; Monti, L.; Sumini, M.; Okawa, T.

    2006-01-01

    A spectrum of Encapsulated Nuclear Heat Source (ENHS) reactors have been conceptually designed over the last few years; they span a power range from 10 MWe to -200 MWe and consider a number of coolants and fuel types. Common features of all these designs include very long life cores - exceeding 20 effective full power years; nearly zero burnup reactivity swing; natural circulation; superb safety; autonomous load following capability; simplicity of operation and maintenance. ENHS reactors could be of particular interest for providing electricity, thermal energy and, possibly, desalinated water to communities that are not connected to a central electricity grid such as to many pacific islands and to remote communities in the mainland of different countries. ENHS reactors provide energy security by virtue of a couple of features: (1) Once an ENHS reactor is commissioned, the community has assured clean energy supply for at least 20 years without needing fuel supply. (2) The energy value of the fuel loaded (in the factory) in the ENHS module is preserved; what is needed for generating energy for additional 20+ years is to remove the fission products, add depleted uranium for makeup fuel, refabricate fuel rods and load into a new module. This fuel recycling is envisioned done by either the supplier country or by a regional or international fuel cycle centre. As the ENHS module is replaced at its entirety at the end of the core life - that is brought about by radiation damage, the ENHS plant life is likely to last for over 100 years. The above features also offer exceptional stability in the price of energy generated by the ENHS reactor. The reference ENHS design will be described followed by a brief description of the design options developed and a summary of their performance characteristics

  11. Geothermal energy: the earth, source of heat and electric power

    International Nuclear Information System (INIS)

    Lenoir, D.

    2005-01-01

    This document provides information on the geothermal energy. It presents the different types of geothermal deposits (very low, low and medium energy geothermal energy), the french deposits and the heat production. The electric power production from the geothermal energy is also discussed with the example of Soultz-sous-Forets. The last part deals with the heat pumps. (A.L.B.)

  12. Feasibility study of a hybrid renewable energy system with geothermal and solar heat sources for residential buildings in South Korea

    International Nuclear Information System (INIS)

    Kim, Young Ju; Woo, Nam Sub; Jang, Sung Cheol; Choi, Jeong Ju

    2013-01-01

    This study investigates the economic feasibility of a hybrid renewable energy system (HRES) that uses geothermal and solar heat sources for water heating, space heating, and space cooling in a residential building in Korea. A small-scale HRES consists of a geothermal heat pump for heating and cooling, solar collectors for hot water, a gas-fired backup boiler, and incidental facilities. To determine whether the Hares will produce any economic benefits for homeowners, an economic analysis is conducted to compare the Hares with conventional methods of space heating and cooling in Korea. The payback period of a small-scale Hares is predicted as a maximum of 9 yrs by life cycle costing based on a performance index compared with conventional systems. However, the payback period of large-scale HRES above 400 RT is 6 yrs to 7 yrs.

  13. Feasibility study of a hybrid renewable energy system with geothermal and solar heat sources for residential buildings in South Korea

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Young Ju; Woo, Nam Sub [Korea Institute of Geoscience and Mineral Resources, Daejeon (Korea, Republic of); Jang, Sung Cheol [Mechatronics Department of the Korea Aviation Polytechnic College, Sacheon (Korea, Republic of); Choi, Jeong Ju [Dong-A University, Busan (Korea, Republic of)

    2013-08-15

    This study investigates the economic feasibility of a hybrid renewable energy system (HRES) that uses geothermal and solar heat sources for water heating, space heating, and space cooling in a residential building in Korea. A small-scale HRES consists of a geothermal heat pump for heating and cooling, solar collectors for hot water, a gas-fired backup boiler, and incidental facilities. To determine whether the Hares will produce any economic benefits for homeowners, an economic analysis is conducted to compare the Hares with conventional methods of space heating and cooling in Korea. The payback period of a small-scale Hares is predicted as a maximum of 9 yrs by life cycle costing based on a performance index compared with conventional systems. However, the payback period of large-scale HRES above 400 RT is 6 yrs to 7 yrs.

  14. Thermal Analysis of a Cracked Half-plane under Moving Point Heat Source

    Directory of Open Access Journals (Sweden)

    He Kuanfang

    2017-09-01

    Full Text Available The heat conduction in half-plane with an insulated crack subjected to moving point heat source is investigated. The analytical solution and the numerical means are combined to analyze the transient temperature distribution of a cracked half-plane under moving point heat source. The transient temperature distribution of the half plane structure under moving point heat source is obtained by the moving coordinate method firstly, then the heat conduction equation with thermal boundary of an insulated crack face is changed to singular integral equation by applying Fourier transforms and solved by the numerical method. The numerical examples of the temperature distribution on the cracked half-plane structure under moving point heat source are presented and discussed in detail.

  15. Recovery Act: Tennessee Energy Efficient Schools Initiative Ground Source Heat Pump Program

    Energy Technology Data Exchange (ETDEWEB)

    Townsend, Terry [Townsend Engineering, Inc., Davenport, IA (United States); Slusher, Scott [Townsend Engineering, Inc., Davenport, IA (United States)

    2017-04-24

    The Tennessee Energy Efficient Schools Initiative (EESI) Hybrid-Water Source Heat Pump (HY-GSHP) Program sought to provide installation costs and operation costs for different Hybrid water source heat pump systems’ configurations so that other State of Tennessee School Districts will have a resource for comparison purposes if considering a geothermal system.

  16. Modeling and analysis of a transcritical rankine power cycle with a low grade heat source

    DEFF Research Database (Denmark)

    Nguyen, Chan; Veje, Christian

    efficiency, exergetic efficiency and specific net power output. A generic cycle configuration has been used for analysis of a geothermal energy heat source. This model has been validated against similar calculations using industrial waste heat as the energy source. Calculations are done with fixed...

  17. Design and modelling of a novel compact power cycle for low temperature heat sources

    DEFF Research Database (Denmark)

    Wronski, Jorrit; Skovrup, Morten Juel; Elmegaard, Brian

    2012-01-01

    Power cycles for the efficient use of low temperature heat sources experience increasing attention. This paper describes an alternative cycle design that offers potential advantages in terms of heat source exploitation. A concept for a reciprocating expander is presented that performs both, work ...

  18. Optimization of operating parameters of ground source heat pump system for space heating and cooling by Taguchi method and utility concept

    International Nuclear Information System (INIS)

    Sivasakthivel, T.; Murugesan, K.; Thomas, H.R.

    2014-01-01

    Highlights: • Ground Source Heat Pump (GSHP) technology is suitable for both heating and cooling. • Important parameters that affect the GSHP performance has been listed. • Parameters of GSHP system has been optimized for heating and cooling mode. • Taguchi technique and utility concept are developed for GSHP optimization. - Abstract: Use of ground source energy for space heating applications through Ground Source Heat pump (GSHP) has been established as an efficient thermodynamic process. The electricity input to the GSHP can be reduced by increasing the COP of the system. However, the COP of a GSHP system will be different for heating and cooling mode operations. Hence in order to reduce the electricity input to the GSHP, an optimum value of COP has to be determined when GSHP is operated in both heating and cooling modes. In the present research, a methodology is proposed to optimize the operating parameters of a GSHP system which will operate on both heating and cooling modes. Condenser inlet temperature, condenser outlet temperature, dryness fraction at evaporator inlet and evaporator outlet temperature are considered as the influencing parameters of the heat pump. Optimization of these parameters for only heating or only cooling mode operation is achieved by employing Taguchi method for three level variations of the above parameters using an L 9 (3 4 ) orthogonal array. Higher the better concept has been used to get a higher COP. A computer program in FORTAN has been developed to carry out the computations and the results have been analyzed for the optimum conditions using Signal-to-Noise (SN) ratio and Analysis Of Variance (ANOVA) method. Based on this analysis, the maximum COP for only heating and only cooling operation are obtained as 4.25 and 3.32 respectively. By making use of the utility concept both the higher values of COP obtained for heating and cooling modes are optimized to get a single optimum COP for heating and cooling modes. A single

  19. Optimal sizing of a multi-source energy plant for power heat and cooling generation

    International Nuclear Information System (INIS)

    Barbieri, E.S.; Dai, Y.J.; Morini, M.; Pinelli, M.; Spina, P.R.; Sun, P.; Wang, R.Z.

    2014-01-01

    Multi-source systems for the fulfilment of electric, thermal and cooling demand of a building can be based on different technologies (e.g. solar photovoltaic, solar heating, cogeneration, heat pump, absorption chiller) which use renewable, partially renewable and fossil energy sources. Therefore, one of the main issues of these kinds of multi-source systems is to find the appropriate size of each technology. Moreover, building energy demands depend on the climate in which the building is located and on the characteristics of the building envelope, which also influence the optimal sizing. This paper presents an analysis of the effect of different climatic scenarios on the multi-source energy plant sizing. For this purpose a model has been developed and has been implemented in the Matlab ® environment. The model takes into consideration the load profiles for electricity, heating and cooling for a whole year. The performance of the energy systems are modelled through a systemic approach. The optimal sizing of the different technologies composing the multi-source energy plant is investigated by using a genetic algorithm, with the goal of minimizing the primary energy consumption only, since the cost of technologies and, in particular, the actual tariff and incentive scenarios depend on the specific country. Moreover economic considerations may lead to inadequate solutions in terms of primary energy consumption. As a case study, the Sino-Italian Green Energy Laboratory of the Shanghai Jiao Tong University has been hypothetically located in five cities in different climatic zones. The load profiles are calculated by means of a TRNSYS ® model. Results show that the optimal load allocation and component sizing are strictly related to climatic data (e.g. external air temperature and solar radiation)

  20. 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.

  1. Experimental Research of a Water-Source Heat Pump Water Heater System

    OpenAIRE

    Zhongchao Zhao; Yanrui Zhang; Haojun Mi; Yimeng Zhou; Yong Zhang

    2018-01-01

    The heat pump water heater (HPWH), as a portion of the eco-friendly technologies using renewable energy, has been applied for years in developed countries. Air-source heat pump water heaters and solar-assisted heat pump water heaters have been widely applied and have become more and more popular because of their comparatively higher energy efficiency and environmental protection. Besides use of the above resources, the heat pump water heater system can also adequately utilize an available wat...

  2. Estimation of spatially varying heat transfer coefficient from a flat plate with flush mounted heat sources using Bayesian inference

    Science.gov (United States)

    Jakkareddy, Pradeep S.; Balaji, C.

    2016-09-01

    This paper employs the Bayesian based Metropolis Hasting - Markov Chain Monte Carlo algorithm to solve inverse heat transfer problem of determining the spatially varying heat transfer coefficient from a flat plate with flush mounted discrete heat sources with measured temperatures at the bottom of the plate. The Nusselt number is assumed to be of the form Nu = aReb(x/l)c . To input reasonable values of ’a’ and ‘b’ into the inverse problem, first limited two dimensional conjugate convection simulations were done with Comsol. Based on the guidance from this different values of ‘a’ and ‘b’ are input to a computationally less complex problem of conjugate conduction in the flat plate (15mm thickness) and temperature distributions at the bottom of the plate which is a more convenient location for measuring the temperatures without disturbing the flow were obtained. Since the goal of this work is to demonstrate the eficiacy of the Bayesian approach to accurately retrieve ‘a’ and ‘b’, numerically generated temperatures with known values of ‘a’ and ‘b’ are treated as ‘surrogate’ experimental data. The inverse problem is then solved by repeatedly using the forward solutions together with the MH-MCMC aprroach. To speed up the estimation, the forward model is replaced by an artificial neural network. The mean, maximum-a-posteriori and standard deviation of the estimated parameters ‘a’ and ‘b’ are reported. The robustness of the proposed method is examined, by synthetically adding noise to the temperatures.

  3. Tropic of Langdale. [River water as a heat source for leisure centre

    Energy Technology Data Exchange (ETDEWEB)

    Cooper, K.

    1986-03-01

    A brief report is given of a unique example of energy management in a Lake District leisure centre. At the site of a former gunpowder mill, river water was directed over a mill race in which a heat exchanger was installed. Heat taken from the river is upgraded by heat pumps, thus providing the base heating and hot water for the leisure centre.

  4. Off-design performance analysis of organic Rankine cycle using real operation data from a heat source plant

    International Nuclear Information System (INIS)

    Kim, In Seop; Kim, Tong Seop; Lee, Jong Jun

    2017-01-01

    Highlights: • ORC systems driven by waste or residual heat from a combined cycle cogeneration plant were analyzed. • An off-design analysis model was developed and validated with commercial ORC data. • A procedure to predict the actual variation of ORC performance using the off-design model was set up. • The importance of using long-term operation data of the heat source plant was demonstrated. - Abstract: There has been increasing demand for cogeneration power plants, which provides high energy utilization. Research on upgrading power plant performance is also being actively pursued. The organic Rankine cycle (ORC) can operate with mid- and low-temperature heat sources and is suitable for enhancing performance of existing power plants. In this study, an off-design analysis model for the ORC was developed, which is driven by waste heat or residual heat from a combined cycle cogeneration plant. The applied heat sources are the exhaust gas from the heat recovery steam generator (Case 1) and waste heat from a heat storage unit (Case 2). Optimal design points of the ORC were selected based on the design heat source condition of each case. Then, the available ORC power output for each case was predicted using actual long-term plant operation data and a validated off-design analysis model. The ORC capacity of Case 2 was almost two times larger than that of Case 1. The predicted average electricity generation of both cases was less than the design output. The results of this paper reveal the importance of both the prediction of electricity generation using actual plant operation data and the need for optimal ORC system sizing.

  5. Point, surface and volumetric heat sources in the thermal modelling of selective laser melting

    Science.gov (United States)

    Yang, Yabin; Ayas, Can

    2017-10-01

    Selective laser melting (SLM) is a powder based additive manufacturing technique suitable for producing high precision metal parts. However, distortions and residual stresses within products arise during SLM because of the high temperature gradients created by the laser heating. Residual stresses limit the load resistance of the product and may even lead to fracture during the built process. It is therefore of paramount importance to predict the level of part distortion and residual stress as a function of SLM process parameters which requires a reliable thermal modelling of the SLM process. Consequently, a key question arises which is how to describe the laser source appropriately. Reasonable simplification of the laser representation is crucial for the computational efficiency of the thermal model of the SLM process. In this paper, first a semi-analytical thermal modelling approach is described. Subsequently, the laser heating is modelled using point, surface and volumetric sources, in order to compare the influence of different laser source geometries on the thermal history prediction of the thermal model. The present work provides guidelines on appropriate representation of the laser source in the thermal modelling of the SLM process.

  6. Ground-Coupling with Water Source Heat Pumps

    Energy Technology Data Exchange (ETDEWEB)

    Kavanaugh, S.

    0001-01-01

    Ground-coupled heat pumps (GCHPs) have been receiving increasing attention in recent years. In areas where the technology has been properly applied, they are the system of choice because of their reliability, high level of comfort, low demand, and low operating costs. Initially these systems were most popular in rural, residential applications where heating requirements were the primary consideration. However, recent improvements in heat pumps units and installation procedures have expanded the market to urban and commercial applications. This paper discusses some of the current activity in the commercial sector. The basic system and nomenclature are discussed. Several variations for commercial buildings are presented along with examples of systems in operation. Several advantages and disadvantages are listed. Operating and installation costs are briefly discussed. Finally, the GCHP is presented as an alternative that is able to counter much of the criticism leveled by the natural gas industry toward conventional heat pumps.

  7. Ground-Coupling with Water Source Heat Pumps

    Energy Technology Data Exchange (ETDEWEB)

    Kavanaugh, S

    0000-12-30

    Ground-coupled heat pumps (GCHPs) have been receiving increasing attention in recent years. In areas where the technology has been properly applied, they are the system of choice because of their reliability, high level of comfort, low demand, and low operating costs. Initially these systems were most popular in rural, residential applications where heating requirements were the primary consideration. However, recent improvements in heat pumps units and installation procedures have expanded the market to urban and commercial applications. This paper discusses some of the current activity in the commercial sector. The basic system and nomenclature are discussed. Several variations for commercial buildings are presented along with examples of systems in operation. Several advantages and disadvantages are listed. Operating and installation costs are briefly discussed. Finally, the GCHP is presented as an alternative that is able to counter much of the criticism leveled by the natural gas industry toward conventional heat pumps.

  8. Air-Source Integrated Heat Pump System Development – Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Baxter, Van D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Rice, C. Keith [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Munk, Jeffrey D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Ally, Moonis R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Shen, Bo [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Uselton, R. B. [Lennox Industries, Inc., Knoxville, TN (United States)

    2017-07-01

    Between October 2007 and September 2017, Oak Ridge National Laboratory (ORNL) and Lennox Industries, Inc. (Lennox) engaged in a Cooperative Research and Development Agreement (CRADA) to develop an air-source integrated heat pump (AS-IHP) system for the US residential market. The Lennox AS-IHP concept consisted of a high-efficiency air-source heat pump (ASHP) for space heating and cooling services and a separate heat pump water heater/dehumidifier (WH/DH) module for domestic water heating and dehumidification (DH) services. A key feature of this system approach with the separate WH/DH is capability to pretreat (i.e., dehumidify) ventilation air and dedicated whole-house DH independent of the ASHP. Two generations of laboratory prototype WH/DH units were designed, fabricated, and lab tested. Performance maps for the system were developed using the latest research version of the US Department of Energy/ORNL heat pump design model (Rice 1992; Rice and Jackson 2005; Shen et al. 2012) as calibrated against the lab test data. These maps served as the input to TRNSYS (Solar Energy Laboratory et al. 2010) to predict annual performance relative to a baseline suite of equipment meeting minimum efficiency standards in effect in 2006 (i.e., a combination of an ASHP with a seasonal energy efficiency ratio (SEER) of 13 and resistance water heater with an energy factor (EF) of 0.9). Predicted total annual energy savings (based on use of a two-speed ASHP and the second-generation WH/DH prototype for the AS-IHP), while providing space conditioning, water heating, and dehumidification for a tight, well-insulated 2600 ft2 (242 m2) house at three US locations, ranged from 33 to 36%, averaging 35%, relative to the baseline system. The lowest savings were seen at the cold-climate Chicago location. Predicted energy use for water heating was reduced by about 50 to 60% relative to a resistance WH.

  9. Process for adapting a heat source and a thermal machine by temporary heat storage

    International Nuclear Information System (INIS)

    Cahn, R.P.; Nicholson, E.W.

    1975-01-01

    The process described is intended to ensure the efficient use of the heat from a nuclear reactor or from a furnace burning fossil fuel at constant power, and of a boiler in a power station comprising a multi-stage steam turbine, the steam extracted from the turbine being used for pre-heating the boiler feed water. This process is most flexible with a varying load. It includes the high temperature storage of the excess heat energy in a low vapor pressure storage liquid (hydrocarbon oils, molten salts or liquid metals) at atmospheric pressure when the demand is low; then, when the energy demand is at its height, the reduction of steam extraction from the turbine with simultaneous utilisation of the hot heat storage liquid for the various maintenance heating functions of the power station by heat exchange, so that the heat can expand totally in the turbine with generation of energy [fr

  10. Annual investigation of vertical type ground source heat pump system performance on a wall heating and cooling system in Istanbul

    Energy Technology Data Exchange (ETDEWEB)

    Akbulut, U.; Yoru, Y.; Kincay, O. [Department of Mechanical Engineering, Yildiz Technical University (Turkey)], email: akbulutugur@yahoo.com, email: yilmazyoru@gmail.com, email: okincay@yildiz.edu.tr

    2011-07-01

    Wall heating and cooling systems (WHCS) are equipped with heating serpentines or panels for water circulation. These systems operate in a low temperature range so they are preferable to other, conventional systems. Furthermore, when these systems are connected to a ground source heat pump (GSHP) system, energy performance and thermal comfort are further enhanced. The purpose of this paper is to report the results of an annual inspection done on a vertical type ground-coupled heat pump systems (V-GSHP) WHCS in Istanbul and present the results. The performance data from the Yildiz Renewable Energy House at Davutpasa Campus of Yildiz Technical University, Istanbul, Turkey, during the year 2010 were collected and analyzed. The conclusions drawn from the inspection and analysis were listed in this paper. Using renewable energy sources effectively will bring both economic and environmental benefits and it is hoped that the use of these energy efficient WHCS systems will become widespread.

  11. An analysis of the vapor flow and the heat conduction through the liquid-wick and pipe wall in a heat pipe with single or multiple heat sources

    Science.gov (United States)

    Chen, Ming-Ming; Faghri, Amir

    1990-01-01

    A numerical analysis is presented for the overall performance of heat pipes with single or multiple heat sources. The analysis includes the heat conduction in the wall and liquid-wick regions as well as the compressibility effect of the vapor inside the heat pipe. The two-dimensional elliptic governing equations in conjunction with the thermodynamic equilibrium relation and appropriate boundary conditions are solved numerically. The solutions are in agreement with existing experimental data for the vapor and wall temperatures at both low and high operating temperatures.

  12. Ground source geothermal heat. Ground source heat pumps and underground thermal energy storage systems. Proceedings; Oberflaechennahe Geothermie. Erdgekoppelte Waermepumpen und unterirdische thermische Energiespeicher. Tagungsband

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2009-07-01

    At the ninth international user forum on shallow geothermal heat on 28th and 29th April, 2009, at BadStaffelstein (Federal Republic of Germany), the following lectures were held: (1) Information system on shallow geothermal heat for Bavaria (Marcellus Schulze); (2) Calculation of the spreading of temperature anomalies in groundwater as an instrument of planning of heat pump systems (Wolfgang Rauch); (3) Comparison of models for simulation of deep geothermal probes (Markus Proell); (4) Impact of the geometry of boreholes and probes on heat transport (Manfred Reuss); (5) Thermal respond tests and temperature depth profiles - Experience from research and practice (Markus Kuebert); (6) A model of simulation for the investigation of the impact of different heat transfer fluids on the efficiency of ground source heat pump devices (Roland Koenigsdorff); (7) The research project EWSplus - Investigations for quality assurance of geothermal probes (Mathieu Riegger); (8) Quality management of plants for the utilization of shallow geothermal heat with geothermal probes - the example of Baden-Wuerttemberg (Bruno Lorinser, Ingrid Stober); (9) Not every heat pump contributes to climate protection (Falk Auer); (10) Field measurements of heat pumps in residential buildings with modern standard and in older buildings (Marek Miara); (11) System technology for a great annual performance factor (Werner Schenk); (12) Modification of older geothermal heat probe devices for use with modern heat pumps (Klaus Friedrich Staerk); (13) Energy-efficient modernisation of a pensioners' condominium from the 1970s with solar-geothermal-air (Michael Guigas); (14) Evaluation and optimization of operation of seasonal storage systems in the foundations of office buildings (Herdis Kipry); (15) Evaluation of an innovative heating and cooling concept with rain water vessels, thermo-active building components and phase change materials in a residential building (Doreen Kalz); (16) Contracts for ground

  13. Heating with ice. Efficient heating source for heat pumps. Primary source storage. Alternative to soil sensors and soil collectors; Heizen mit Eis. Effiziente Waermequelle fuer Waermepumpen. Primaerquellenspeicher, Alternative zu Erdsonden und Erdkollektoren

    Energy Technology Data Exchange (ETDEWEB)

    Tippelt, Egbert [Viessmann, Allendorf (Germany)

    2011-12-15

    For several years heat pumps have taken up a fixed place in the mix of annually installed thermal generators. Thus, in the year 2010 every tenth newly installed heater was a heat pump. A new concept for the development and utilization of natural heat now makes this technology even more attractive. From this perspective, the author of the contribution under consideration reports on a SolarEis storage. This SolarEis storage consists of a cylindrical concrete tank with two heat exchangers consiting of plastic pipes. The SolarEis storage uses outdoor air, solar radiation and soil as heat sources for brine / water heat pumps simultaneously.

  14. Case study for ARRA-funded ground-source heat pump (GSHP) demonstration at Oakland University

    Energy Technology Data Exchange (ETDEWEB)

    Im, Piljae [ORNL; Liu, Xiaobing [ORNL

    2015-09-01

    High initial costs and lack of public awareness of ground-source heat pump (GSHP) technology are the two major barriers preventing rapid deployment of this energy-saving technology in the United States. Under the American Recovery and Reinvestment Act (ARRA), 26 GSHP projects have been competitively selected and carried out to demonstrate the benefits of GSHP systems and innovative technologies for cost reduction and/or performance improvement. This paper highlights the findings of a case study of one of the ARRA-funded GSHP demonstration projects, a ground-source variable refrigerant flow (GS-VRF) system installed at the Human Health Building at Oakland University in Rochester, Michigan. This case study is based on the analysis of measured performance data, maintenance records, construction costs, and simulations of the energy consumption of conventional central heating, ventilation, and air-conditioning (HVAC) systems providing the same level of space conditioning as the demonstrated GS-VRF system. The evaluated performance metrics include the energy efficiency of the heat pump equipment and the overall GS-VRF system, pumping performance, energy savings, carbon emission reductions, and cost-effectiveness of the GS-VRF system compared with conventional HVAC systems. This case study also identified opportunities for reducing uncertainties in the performance evaluation, improving the operational efficiency, and reducing the installed cost of similar GSHP systems in the future.

  15. A thermoacoustic engine capable of utilizing multi-temperature heat sources

    International Nuclear Information System (INIS)

    Qiu Limin; Wang Bo; Sun Daming; Liu Yu; Steiner, Ted

    2009-01-01

    Low-grade energy is widespread. However, it cannot be utilized with high thermal efficiency directly. Following the principle of thermal energy cascade utilization, a thermoacoustic engine (TE) with a new regenerator that can be driven by multiple heat sources at different temperature levels is proposed. Taking a regenerator that utilizes heat sources at two temperatures as an example, theoretical research has been conducted on a traveling-wave TE with the new regenerator to predict its performance. Experimental verification is also done to demonstrate the benefits of the new regenerator. Results indicate that a TE with the new regenerator utilizing additional heat at a lower temperature experiences an increase in pressure ratio, acoustic power, efficiency, and exergy efficiency with proper heat input at an appropriate temperature at the mid-heater. A regenerator that uses multi-temperature heat sources can provide a means of recovering lower grade heat.

  16. Strategic GHG reduction through the use of ground source heat pump technology

    International Nuclear Information System (INIS)

    Hanova, J; Dowlatabadi, H

    2007-01-01

    Higher energy prices and concern about climate change is drawing increasing attention to ground source heat pump (GSHP) systems. Their clear advantage lies in being able to provide heating using 25 to 30% of the energy consumed by even the most efficient conventional alternatives. Their drawback has been high capital costs and uncertainty about whether the emissions associated with the electric power used to energise the system has higher system-wide emissions than the highest-efficiency furnaces. This study delineates circumstances under which GSHP systems achieve net emission reductions, for different electricity generation methods, heat pump efficiencies, and heating loads. We illustrate the effect of relative fuel prices on annual operating savings using fuel prices in multiple countries. Annual operating savings determine how rapidly the technology achieves payback and then generates return on the initial capital investment. Finally, we highlight the least cost supply curve for using GSHP to reduce greenhouse gas emissions. Using the United States as a base reference case, this study explores the potential of GSHP in cold-climate countries worldwide

  17. Performance analysis on a large scale borehole ground source heat pump in Tianjin cultural centre

    Science.gov (United States)

    Yin, Baoquan; Wu, Xiaoting

    2018-02-01

    In this paper, the temperature distribution of the geothermal field for the vertical borehole ground-coupled heat pump was tested and analysed. Besides the borehole ground-coupled heat pump, the system composed of the ice storage, heat supply network and cooling tower. According to the operation data for nearly three years, the temperature constant zone is in the ground depth of 40m -120m with a temperature gradient of about 3.0°C/100m. The temperature of the soil dropped significantly in the heating season, increased significantly in the cooling season, and reinstated in the transitional season. With the energy balance design of the heating and cooling and the existence of the soil thermal inertia, the soil temperature stayed in a relative stable range and the ground source heat pump system was operated with a relative high efficiency. The geothermal source heat pump was shown to be applicable for large scale utilization.

  18. Case Study for the ARRA-Funded Ground Source Heat Pump Demonstration at Ball State University

    Energy Technology Data Exchange (ETDEWEB)

    Im, Piljae [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Liu, Xiaobing [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Henderson, Jr., Hugh [CDH Energy Corp., Beijing (China)

    2016-12-01

    With funding provided by the American Recovery and Reinvestment Act (ARRA), 26 ground-source heat pump (GSHP) projects were competitively selected in 2009 to demonstrate the benefits of GSHP systems and innovative technologies for cost reduction and/or performance improvement. One of the selected demonstration projects is a district central GSHP system installed at Ball State University (BSU) in Muncie, IN. Prior to implementing the district GSHP system, 47 major buildings in BSU were served by a central steam plant with four coal-fired and three natural-gas-fired steam boilers. Cooling was provided by five water-cooled centrifugal chillers at the District Energy Station South (DESS). The new district GSHP system replaced the existing coal-fired steam boilers and conventional water-cooled chillers. It uses ground-coupled heat recovery (HR) chillers to meet the simultaneous heating and cooling demands of the campus. The actual performance of the GSHP system was analyzed based on available measured data from August 2015 through July 2016, construction drawings, maintenance records, personal communications, and construction costs. Since Phase 1 was funded in part by the ARRA grant, it is the focus of this case study. The annual energy consumption of the GSHP system was calculated based on the available measured data and other related information. It was compared with the performance of a baseline scenario— a conventional water-cooled chiller and natural-gas-fired boiler system, both of which meet the minimum energy efficiencies allowed by the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE 90.1-2013). The comparison was made to determine source energy savings, energy cost savings, and CO2 emission reductions achieved by the GSHP system. A cost analysis was performed to evaluate the simple payback of the GSHP system. The following sections summarize the results of the analysis, the lessons learned, and recommendations for improvement

  19. Radiogenic heat production and the earth's heat balance. A source of arguments in geoscience

    International Nuclear Information System (INIS)

    Kuczera, B.

    2008-01-01

    The terrestrial heat flow into interstellar space amounts to approx. 32 TW on the basis of an average heat flow density of 63 mW per sq.m. of earth surface. The loss flow derives part of the energy from the residual heat of the nascent phase of the earth (approx. 40%) and the other part from the natural disintegration of longlived radionuclides, i.e. radiogenic heat production (roughly 60%). This concept met with broad consensus in the geosciences until the 1980s. In 1993, Pollack et al. concluded from the evaluation of recent measured data that heat loss via the oceanic crust of the earth was clearly higher, which raises the loss flow to a total of 44 TW. This is contradicted by Hoffmeister and Criss, who conclude from a modified geochemical model that the total heat loss of 31 TW is fully compensated by radiogenic heat production. In 2001, C. Herndon introduced a new idea into the discussion. According to his thesis, planetary differentiation caused a nuclear georeactor to be created in the center of the earth, whose continuous thermal power of approx. 3 TW contributes to compensating heat losses. Physicists and geoscientists hope to be able to derive new findings on this thesis and on the distribution of radiogenic heat production in the interior of the earth from the planned geo-neutrino experiment in Homestake, USA. (orig.)

  20. Comprehensive thermodynamic analysis of a renewable energy sourced hybrid heating system combined with latent heat storage

    International Nuclear Information System (INIS)

    Utlu, Zafer; Aydın, Devrim; Kıncay, Olcay

    2014-01-01

    Highlights: • An experimental thermal investigation of hybrid renewable heating system is presented. • Analyses were done by using real data obtained from a prototype structure. • Exergy efficiency of system components investigated during discharging period are close to each other as 32%. • The average input energy and exergy rates to the LHS were 0.770 and 0.027 kW. • Overall total energy and exergy efficiencies of LHS calculated as 72% and 28.4%. - Abstract: In this study an experimental thermal investigation of hybrid renewable heating system is presented. Latent heat storage stores energy, gained by solar collectors and supplies medium temperature heat to heat pump both day time also night time while solar energy is unavailable. In addition to this an accumulation tank exists in the system as sensible heat storage. It provides supply–demand balance with storing excess high temperature heat. Analyses were done according to thermodynamic’s first and second laws by using real data obtained from a prototype structure, built as part of a project. Results show that high percent of heat loses took place in heat pump with 1.83 kW where accumulator-wall heating cycle followed it with 0.42 kW. Contrarily highest break-down of exergy loses occur accumulator-wall heating cycle with 0.28 kW. Averagely 2.42 kW exergy destruction took place in whole system during the experiment. Solar collectors and heat pump are the promising components in terms of exergy destruction with 1.15 kW and 1.09 kW respectively. Exergy efficiency of system components, investigated during discharging period are in a close approximately of 32%. However, efficiency of solar collectors and charging of latent heat storage are 2.3% and 7% which are relatively low. Average overall total energy and exergy efficiencies of latent heat storage calculated as 72% and 28.4% respectively. Discharging energy efficiency of latent heat storage is the highest through all system components. Also heat

  1. Transition to chaos in a square enclosure containing internal heat sources

    Energy Technology Data Exchange (ETDEWEB)

    Baytas, A.C. [Institute For Nuclear Energy, Istanbul (Turkey)

    1995-09-01

    A numerical investigation is performed to study the transition from steady to chaotic flow of a fluid confined in a two-dimensional square cavity. The cavity has rigid walls of constant temperature containing uniformly distributed internal heat source. Effects of the Rayleigh number of flow and heat transfer rates are studied. In addition to, same problem is solved for sinusoidally changing internal heat source to show its effect on the flow model and heat transfer of the enclosures. Details of oscillatory solutions and flow bifurcations are presented.

  2. Current status of ground source heat pumps and underground thermal energy storage in Europe

    Energy Technology Data Exchange (ETDEWEB)

    Sanner, B. [Justus Liebig University, Giessen (Germany). Institute of Applied Geosciences; Karytsas, C.; Mendrinos, D. [Center for Renewable Energy Sources, Pikermi (Greece); Rybach, L. [Geowatt AG, Zurich (Switzerland)

    2003-12-01

    Geothermal Heat Pumps, or Ground Coupled Heat Pumps (GCHP), are systems combining a heat pump with a ground heat exchanger (closed loop systems), or fed by ground water from a well (open loop systems). They use the earth as a heat source when operating in heating mode, with a fluid (usually water or a water-antifreeze mixture) as the medium that transfers the heat from the earth to the evaporator of the heat pump, thus utilising geothermal energy. In cooling mode, they use the earth as a heat sink. With Borehole Heat Exchangers (BHE), geothermal heat pumps can offer both heating and cooling at virtually any location, with great flexibility to meet any demands. More than 20 years of R and D focusing on BUE in Europe has resulted in a well-established concept of sustainability for this technology, as well as sound design and installation criteria. Recent developments are the Thermal Response Test, which allows in-situ-determination of ground thermal properties for design purposes, and thermally enhanced grouting materials to reduce borehole thermal resistance. For cooling purposes, but also for the storage of solar or waste heat, the concept of underground thermal energy storage (UTES) could prove successful. Systems can be either open (aquifer storage) or can use BHE (borehole storage). Whereas cold storage is already established on the market, heat storage, and, in particular, high temperature heat storage (> 50{sup o}C) is still in the demonstration phase. Despite the fact that geothermal heat pumps have been in use for over 50 years now (the first were in the USA), market penetration of this technology is still in its infancy, with fossil fuels dominating the space heating market and air-to-air heat pumps that of space cooling. In Germany, Switzerland, Austria, Sweden, Denmark, Norway, France and the USA, large numbers of geothermal heat pumps are already operational, and installation guidelines, quality control and contractor certification are now major issues

  3. A simulation study on the operating performance of a solar-air source heat pump water heater

    International Nuclear Information System (INIS)

    Xu Guoying; Zhang Xiaosong; Deng Shiming

    2006-01-01

    A simulation study on the operating performance of a new type of solar-air source heat pump water heater (SAS-HPWH) has been presented. The SAS-HPWH used a specially designed flat-plate heat collector/evaporator with spiral-finned tubes to obtain energy from both solar irradiation and ambient air for hot water heating. Using the meteorological data in Nanjing, China, the simulation results based on 150 L water heating capacity showed that such a SAS-HPWH can heat water up to 55 deg. C efficiently under various weather conditions all year around. In this simulation study, the influences of solar radiation, ambient temperature and compressor capacity on the performance of the SAS-HPWH were analyzed. In order to improve the overall operating performance, the use of a variable-capacity compressor has been proposed

  4. Comparison between off-resonance and electron Bernstein waves heating regime in a microwave discharge ion source

    Energy Technology Data Exchange (ETDEWEB)

    Castro, G.; Di Giugno, R.; Miracoli, R. [INFN- Laboratori Nazionali del Sud, via S. Sofia 62, 95123 Catania (Italy); Universita degli Studi di Catania, Dipartimento di Fisica e Astronomia, V. S. Sofia 64, 95123 Catania (Italy); Mascali, D. [INFN- Laboratori Nazionali del Sud, via S. Sofia 62, 95123 Catania (Italy); CSFNSM, Viale A. Doria 6, 95125 Catania (Italy); Romano, F. P. [INFN- Laboratori Nazionali del Sud, via S. Sofia 62, 95123 Catania (Italy); CNR-IBAM Via Biblioteca 4, 95124 Catania (Italy); Celona, L.; Gammino, S.; Lanaia, D.; Ciavola, G. [INFN- Laboratori Nazionali del Sud, via S. Sofia 62, 95123 Catania (Italy); Serafino, T. [CSFNSM, Viale A. Doria 6, 95125 Catania (Italy); Di Bartolo, F. [Universita di Messina, Ctr. da Papardo-Sperone, 98100 Messina (Italy); Gambino, N. [INFN- Laboratori Nazionali del Sud, via S. Sofia 62, 95123 Catania (Italy); Universita degli Studi di Catania, Dipartimento di Fisica e Astronomia, V. S. Sofia 64, 95123 Catania (Italy); IET-Institute of Energy Technology, LEC-Laboratory for Energy Conversion, ETH Zurich, Sonneggstrasse 3, CH-8092 Zurich (Switzerland)

    2012-02-15

    A microwave discharge ion source (MDIS) operating at the Laboratori Nazionali del Sud of INFN, Catania has been used to compare the traditional electron cyclotron resonance (ECR) heating with an innovative mechanisms of plasma ignition based on the electrostatic Bernstein waves (EBW). EBW are obtained via the inner plasma electromagnetic-to-electrostatic wave conversion and they are absorbed by the plasma at cyclotron resonance harmonics. The heating of plasma by means of EBW at particular frequencies enabled us to reach densities much larger than the cutoff ones. Evidences of EBW generation and absorption together with X-ray emissions due to high energy electrons will be shown. A characterization of the discharge heating process in MDISs as a generalization of the ECR heating mechanism by means of ray tracing will be shown in order to highlight the fundamental physical differences between ECR and EBW heating.

  5. Link between intermittent electrical energy sources and district heating sector

    DEFF Research Database (Denmark)

    Dominkovic, Dominik Franjo

    2016-01-01

    Energy has always been one of the key challenges in planning of societies' development worldwide. The COP conference in Paris in December 2015 has shown unprecedented mutual understanding of harmful consequences climate change can cause. Integrating power and heating sectors in an efficient way...

  6. The structural design of the experimental equipment for unconventional heating water using heat transfer surfaces located in the heat source

    Directory of Open Access Journals (Sweden)

    Jandačka J.

    2013-04-01

    Full Text Available Flue gas temperature at throat of most industrially produced fireplaces is around 250 to 350 °C. It's quite interesting thermal potential, which can be even before sucking up the chimney back utilize. One of the potential uses of this device to heat the hot water. Article refers to the structural design of such a device, which works with the transfer of heat through a substance changes phase from liquid to steam in a sealed tube (heat pipe. Benefits of heat pipes is their light weight, the thermal effect of a rapid and low maintenance costs.

  7. The structural design of the experimental equipment for unconventional heating water using heat transfer surfaces located in the heat source

    Science.gov (United States)

    Kaduchová, K.; Lenhard, R.; Gavlas, S.; Jandačka, J.

    2013-04-01

    Flue gas temperature at throat of most industrially produced fireplaces is around 250 to 350 °C. It's quite interesting thermal potential, which can be even before sucking up the chimney back utilize. One of the potential uses of this device to heat the hot water. Article refers to the structural design of such a device, which works with the transfer of heat through a substance changes phase from liquid to steam in a sealed tube (heat pipe). Benefits of heat pipes is their light weight, the thermal effect of a rapid and low maintenance costs.

  8. Barriers for district heating as a source of flexibility for the electricity system

    DEFF Research Database (Denmark)

    Skytte, Klaus; Olsen, Ole Jess; Soysal, Emilie Rosenlund

    2017-01-01

    of wind power. Power-to-heat technologies, electric boilers and heat pumps are blocked by high tariffs and taxes. A calculation of the heat costs of different DH technologies demonstrates that, under the present price and tax conditions in Denmark and Sweden, CHP and power-to-heat are unable to compete......The Scandinavian countries Denmark, Norway and Sweden currently deploy large amounts of variable renewable energy (VRE) sources, especially wind power. This calls for additional flexibility in the power market. The right coupling to the underlying national and local district heating (DH) markets...

  9. Analysis and assessment of a new organic Rankine based heat engine system with/without cogeneration

    International Nuclear Information System (INIS)

    Hogerwaard, Janette; Dincer, Ibrahim; Zamfirescu, Calin

    2013-01-01

    A low-temperature heat driven heat engine is proposed as a cost-effective system for power and heat production for small scale applications. The external heat source allows flexibility in the design; the system may be coupled with various available renewable sources including biomass/biofuel/biogas combustion, geothermal heat, concentrated solar radiation, and industrial waste heat, by selecting appropriate off-the-shelf components from the HVAC (heating, ventilation, and air conditioning), refrigeration, and automotive industries for use in an ORC (organic Rankine cycle). A theoretical analysis and an experimental study are carried out for an ORC with R134a as the working fluid, utilizing a low-temperature heat source (T source < 150 °C), with focus on the expansion and boiling processes. The complete ORC model is comprised of models for the expander, working fluid pump, boiler, and condenser. Thermodynamic and heat transfer models are developed to calculate the local and averaged heat transfer coefficient of the working fluid throughout the boiling process, based on the geometry of the selected heat exchanger. Data collected for the experimental ORC test bench are used to validate the expander and boiler models. A case study is performed for the proposed ORC, for cogeneration of power and heat in a residential application. The results of the case study analysis for the proposed ORC system indicate a cycle efficiency of 0.05, exergy efficiency of 0.17, and energy and exergy cogeneration efficiency of 0.87, and 0.35, respectively. - Highlights: • Development and investigation of a scroll based Rankine heat engine operating with R134a. • Thermodynamic analyses of the system and its components. • Heat transfer analyses of boiler and condenser. • Dynamic analysis of expander. • Model validation through performed experiments on an ORC test bench

  10. Economic Model Predictive Control for Hot Water Based Heating Systems in Smart Buildings

    DEFF Research Database (Denmark)

    Awadelrahman, M. A. Ahmed; Zong, Yi; Li, Hongwei

    2017-01-01

    This paper presents a study to optimize the heating energy costs in a residential building with varying electricity price signals based on an Economic Model Predictive Controller (EMPC). The investigated heating system consists of an air source heat pump (ASHP) incorporated with a hot water tank...... as active Thermal Energy Storage (TES), where two optimization problems are integrated together to optimize both the ASHP electricity consumption and the building heating consumption utilizing a heat dynamic model of the building. The results show that the proposed EMPC can save the energy cost by load...

  11. Federal Technology Alert: Ground-Source Heat Pumps Applied to Federal Facilities-Second Edition; FINAL

    International Nuclear Information System (INIS)

    Hadley, Donald L

    2001-01-01

    This Federal Technology Alert, which was sponsored by the U.S. Department of Energy's Office of Federal Energy Management Programs, provides the detailed information and procedures that a Federal energy manager needs to evaluate most ground-source heat pump applications. This report updates an earlier report on ground-source heat pumps that was published in September 1995. In the current report, general benefits of this technology to the Federal sector are described, as are ground-source heat pump operation, system types, design variations, energy savings, and other benefits. In addition, information on current manufacturers, technology users, and references for further reading are provided

  12. Analysis of carbon monoxide production in multihundred-watt heat sources

    International Nuclear Information System (INIS)

    Peterson, D.E.; Mulford, R.N.R.

    1976-05-01

    The production of carbon monoxide observed within Multihundred Watt heat sources placed under storage conditions was analyzed. Results of compositional and isotopic analyses of gas taps performed on eight heat sources are summarized and interpreted. Several proposed CO generation mechanisms are examined theoretically and assessed by applying thermodynamic principles. Outgassing of the heat source graphite followed by oxygen isotopic exchange through the vent assemblies appears to explain the CO production at storage temperatures. Reduction of the plutonia fuel sphere by the CO is examined as a function of temperature and stoichiometry. Experiments that could be performed to investigate possible CO generation mechanisms are discussed

  13. Geothermal heat potential - the source for heating greenhouses in Southestern Europe

    Directory of Open Access Journals (Sweden)

    Urbancl Danijela

    2016-01-01

    Full Text Available The paper presents economically evaluated solutions for heating greenhouses with geothermal potential, if the same greenhouse is placed in two different locations in Southeastern Europe, one in Slovenia and the other in Serbia. The direct geothermal water exploitation using heat exchangers is presented and the remaining heat potential of already used geothermal water is exploited using high temperature heat pumps. Energy demands for heating greenhouses are calculated considering climatic parameters of both locations. Furthermore, different constructions materials are taken into account, and energy demands are evaluated if the same greenhouse is made of 4 mm toughened single glass, double insulated glass or polycarbonate plates. The results show that the geothermal energy usage is economically feasible in both locations, because payback periods are in range from two to almost eight years for different scenarios.

  14. Experimental Research of a Water-Source Heat Pump Water Heater System

    Directory of Open Access Journals (Sweden)

    Zhongchao Zhao

    2018-05-01

    Full Text Available The heat pump water heater (HPWH, as a portion of the eco-friendly technologies using renewable energy, has been applied for years in developed countries. Air-source heat pump water heaters and solar-assisted heat pump water heaters have been widely applied and have become more and more popular because of their comparatively higher energy efficiency and environmental protection. Besides use of the above resources, the heat pump water heater system can also adequately utilize an available water source. In order to study the thermal performance of the water-source heat pump water heater (WSHPWH system, an experimental prototype using the cyclic heating mode was established. The heating performance of the water-source heat pump water heater system, which was affected by the difference between evaporator water fluxes, was investigated. The water temperature unfavorably exceeded 55 °C when the experimental prototype was used for heating; otherwise, the compressor discharge pressure was close to the maximum discharge temperature, which resulted in system instability. The evaporator water flux allowed this system to function satisfactorily. It is necessary to reduce the exergy loss of the condenser to improve the energy utilization of the system.

  15. Domestic energy sources urged as Middle East situation heats up

    International Nuclear Information System (INIS)

    Rodgers, L.M.

    1990-01-01

    This article discusses the alternatives to foreign oil as an energy source for the US in the light of the invasion of Kuwait by Iraq. Topics addressed include the responses of organizations representing various energy sources, the public response of the Department of Energy, the response of conservation advocates, and the Administration's reaction

  16. Technical specifications for the provision of heat and steam sources for INPP and Visaginas. Final report

    International Nuclear Information System (INIS)

    2003-01-01

    In October 1999, the National Energy Strategy was approved by the Lithuanian Parliament. The National Energy Strategy included the decision to close Unit-1 of INPP before 2005. Later is has been decided to close Unit 2 before the end of 2009 as well. The closure and decommissioning will have heavy impact on the heat supply for the city of Visaginas. Unit 1 and Unit 2 of INPP supplies hot water and steam to INPP for process purposes and for space heating of residential and commercial buildings. When Unit 1 is permanently shut down, reliable heat and steam sources independent of the power plants own heat and steam generation facilities are required for safety reasons in the event of shutdown of the remaining unit for maintenance or in an emergency. These steam and heat sources must be operational before single unit operation is envisaged. Provision of a reliable independent heat and steam source is therefore urgent. After both reactors are shut down permanently, a steam source will be needed at the plant for radioactive waste storage and disposal. INPP and DEA has performed a feasibility study for the provision of a reliable heat source for Ignalina Nuclear Power Plant and Visaginas, and the modernisation of Visaginas district heating system. The objective of this project is to prepare technical specifications for the provision of new heat and steam sources for INPP and Visaginas, and for rehabilitation of the heat transmission pipeline between INPP, the back-up boiler station and Visaginas City. The results of the study are presented in detail in the reports and technical specifications: 1. Transient analysis for Visaginas DH system, 2. Non-destructive testing of boiler stations, pump stations and transmission lines, 3. Conceptual design, 4. Technical specifications, Package 1 to 6. The study has suggested: 1. Construction of new steam boiler station, 2. Construction of new heat only boiler station, 3. Renovation of existing back-up heat only boiler station, 4

  17. Atopic dermatitis and indoor use of energy sources in cooking and heating appliances

    Science.gov (United States)

    2012-01-01

    Background Atopic dermatitis (AD) prevalence has considerably increased worldwide in recent years. Studying indoor environments is particularly relevant, especially in industrialised countries where many people spend 80% of their time at home, particularly children. This study is aimed to identify the potential association between AD and the energy source (biomass, gas and electricity) used for cooking and domestic heating in a Spanish schoolchildren population. Methods As part of the ISAAC (International Study of Asthma and Allergies in Childhood) phase III study, a cross-sectional population-based survey was conducted with 21,355 6-to-7-year-old children from 8 Spanish ISAAC centres. AD prevalence, environmental risk factors and the use of domestic heating/cooking devices were assessed using the validated ISAAC questionnaire. Crude and adjusted odds ratios (cOR, aOR) and 95% confidence intervals (CIs) were obtained. A logistic regression analysis was performed (Chi-square test, p-value heating was the only type which obtained a significant aOR (1.13; 95% CI: 1.00-1.27). Finally, the model with all selected confounding variables (sex, BMI, number of siblings, mother’s educational level, smoking habits of parents, truck traffic and geographical area), showed aOR values which were very similar to those obtained in the previous adjusted logistic analysis. None of the results was statistically significant, but the use of electric heating showed an aOR close to significance (1.14; 95% CI: 0.99-1.31). Conclusion In our study population, no statistically significant associations were found between the type of indoor energy sources used and the presence of AD. PMID:23088771

  18. Surface Modification Technology of ODS Alloying Treatment by using Laser Heat Source

    International Nuclear Information System (INIS)

    Kim, H. G.; Kim, I. H.; Choi, B. K.; Park, J. Y.; Koo, Y. H.

    2012-01-01

    The ODS (Oxide Dispersion Strengthed) alloys can be applied as structural materials for components in the core of a nuclear power plants since these components must have a high mechanical strength at high temperature up to 700 .deg. C. This type of alloy was generally manufactured by mechanical alloying from its source metal and Y 2 O 3 powders. The mechanical alloyed powder is subjected to the HIP (Hot Isotatic Pressing) or hot extrusion: and this product is heat treated at target temperature and time. Thus, the Y 2 O 3 particles are dispersed in the metal matrix. These manufacturing process of ODS alloy is very complex and expensive. Also, it is necessary the special techniques to obtain the uniform dispersion and volume control of Y 2 O 3 particles. Another problem is the final product forming such as tube and sheet because the intermediated-product has a high mechanical strength due to the dispersion of Y 2 O 3 particles. The laser cladding techniques was applied on the surface cladding of ceramics and inter-metallic compounds on metal base and ceramic base components to increase corrosion and wear resistance. The laser heat source can be used to the alloying the metal and ceramic materials, because thermally melting of metal and ceramic is possible. So, we are applied on ODS alloy manufacturing by using the laser heat source. The main advantages and disadvantage of this technology can be resumed as follows: · It is possible to apply to the sheet and tube shape component, directly. · Metallurgical damage such as HAZ and severe grain growth is considerably reduced. · Good control of the alloying element of the treated zone · Highly reproducible homogeneous zone · The pores and cracks are suppressed in the treated zone · Oxidation can be prevented during the process. · Good control is possible for the irregular shaped components. · The bulk material alloying is limited by the power of laser source. So, this work is studied on the ODS alloy manufacturing

  19. Multi-objective optimization of a vertical ground source heat pump using evolutionary algorithm

    International Nuclear Information System (INIS)

    Sayyaadi, Hoseyn; Amlashi, Emad Hadaddi; Amidpour, Majid

    2009-01-01

    Thermodynamic and thermoeconomic optimization of a vertical ground source heat pump system has been studied. A model based on the energy and exergy analysis is presented here. An economic model of the system is developed according to the Total Revenue Requirement (TRR) method. The objective functions based on the thermodynamic and thermoeconomic analysis are developed. The proposed vertical ground source heat pump system including eight decision variables is considered for optimization. An artificial intelligence technique known as evolutionary algorithm (EA) has been utilized as an optimization method. This approach has been applied to minimize either the total levelized cost of the system product or the exergy destruction of the system. Three levels of optimization including thermodynamic single objective, thermoeconomic single objective and multi-objective optimizations are performed. In Multi-objective optimization, both thermodynamic and thermoeconomic objectives are considered, simultaneously. In the case of multi-objective optimization, an example of decision-making process for selection of the final solution from available optimal points on Pareto frontier is presented. The results obtained using the various optimization approaches are compared and discussed. Further, the sensitivity of optimized systems to the interest rate, to the annual number of operating hours and to the electricity cost are studied in detail.

  20. Synergistic effect of solar radiation and solar heating to disinfect drinking water sources.

    Science.gov (United States)

    Rijal, G K; Fujioka, R S

    2001-01-01

    Waterborne diseases are still common in developing countries as drinking water sources are contaminated and feasible means to reliably treat and disinfect these waters are not available. Many of these developing countries are in the tropical regions of the world where sunlight is plentiful. The objective of this study was to evaluate the effectiveness of combining solar radiation and solar heating to disinfect contaminated water using a modified Family Sol*Saver System (FSP). The non-UV transmittable cover sheet of the former FSP system was replaced with an UV transmittable plastic cover sheet to enable more wavelengths of sunlight to treat the water. Disinfection efficiency of both systems was evaluated based on reduction of the natural populations of faecal coliform, E. coli, enterococci, C. perfringens, total heterotrophic bacteria, hydrogen sulphide producing bacteria and FRNA virus. The results showed that under sunny and partly sunny conditions, water was heated to critical temperature (60 degrees C) in both the FSP systems inactivating more than 3 log (99.9%) of the concentrations of faecal coliform and E. coli to undetectable levels of heat worked synergistically to enhance the inactivation of faecal indicator bacteria. The relative log removal of indicator microorganism in the FSP treated water was total heterotrophic bacteria heat and radiation effects of sunlight were important in disinfecting water by solar units. The data indicated that direct radiation of sunlight worked synergistically with solar heating of the water to disinfect the water. Thus, effective disinfection was observed even when the water temperature did not reach 60 degrees C. Finally, the hydrogen sulphide test is a simple and reliable test that householders can use to determine whether their water had been sufficiently disinfected.

  1. National Certification Standard for Ground Source Heat Pump Personnel

    Energy Technology Data Exchange (ETDEWEB)

    Kelly, John [Geothermal Heat Pump Consortium, Washington, DC (United States)

    2013-07-31

    The National Certification Standard for the Geothermal Heat Pump Industry adds to the understanding of the barriers to rapid growth of the geothermal heat pump (GHP) industry by bringing together for the first time an analysis of the roles and responsibilities of each of the individual job tasks involved in the design and installation of GHP systems. The standard addresses applicable qualifications for all primary personnel involved in the design, installation, commissioning, operation and maintenance of GHP systems, including their knowledge, skills and abilities. The resulting standard serves as a foundation for subsequent development of curriculum, training and certification programs, which are not included in the scope of this project, but are briefly addressed in the standard to describe ways in which the standard developed in this project may form a foundation to support further progress in accomplishing those other efforts. Follow-on efforts may use the standard developed in this project to improve the technical effectiveness and economic feasibility of curriculum development and training programs for GHP industry personnel, by providing a more complete and objective assessment of the individual job tasks necessary for successful implementation of GHP systems. When incorporated into future certification programs for GHP personnel, the standard will facilitate increased consumer confidence in GHP technology, reduce the potential for improperly installed GHP systems, and assure GHP system quality and performance, all of which benefit the public through improved energy efficiency and mitigated environmental impacts of the heating and cooling of homes and businesses.

  2. Wastewater as a Heat Source for Individual Residence Heating: A Techno-economic Feasibility Study in the Brussels Capital Region

    Directory of Open Access Journals (Sweden)

    Jan Spriet

    2017-09-01

    Full Text Available A large part of the thermal energy in buildings is lost through the drain and ends up as warm wastewater in the sewer system. The installation of heat exchangers in the sewer system enables a rise of the source temperature of heat pumps, increasing their coefficient of performance. To investigate the potential of such a technique in the Brussels Capital Region, a test facility named MYRTES has been installed in the sewer network, the starting point of this facility being to have one heat recovery system per residence. To estimate the heat recovery rate, potentially available in the Brussels Capital Region, the data from this test facility have been used as inputs and validation for a predictive model, considering both the heat recovery and its financial and environmental implications. Simulations show a minimum heating power of the heat pump of 6.3 kW, at a hot water temperature of 45 °C. A maximum of 35% of the buildings in the Brussels Capital Region are eligible for the use of such a system. At current tariffs, the levelized cost of energy for these systems, is lower than for traditional air heat pumps, but is higher than for gas boiler systems. The total equivalent warming impact, however, is estimated to be around 49% lower than for gas boiler systems and around 13% lower than for air heat pumps. In conclusion, heating through these types of systems is more expensive than gas boiler systems, but with increased consumption the competitiveness of these systems improves.

  3. The numerical simulation of heat transfer during a hybrid laser-MIG welding using equivalent heat source approach

    Science.gov (United States)

    Bendaoud, Issam; Matteï, Simone; Cicala, Eugen; Tomashchuk, Iryna; Andrzejewski, Henri; Sallamand, Pierre; Mathieu, Alexandre; Bouchaud, Fréderic

    2014-03-01

    The present study is dedicated to the numerical simulation of an industrial case of hybrid laser-MIG welding of high thickness duplex steel UR2507Cu with Y-shaped chamfer geometry. It consists in simulation of heat transfer phenomena using heat equivalent source approach and implementing in finite element software COMSOL Multiphysics. A numerical exploratory designs method is used to identify the heat sources parameters in order to obtain a minimal required difference between the numerical results and the experiment which are the shape of the welded zone and the temperature evolution in different locations. The obtained results were found in good correspondence with experiment, both for melted zone shape and thermal history.

  4. Thermal non-equilibrium heat transfer in a porous cavity in the presence of bio-chemical heat source

    Directory of Open Access Journals (Sweden)

    Nazari Mohsen

    2015-01-01

    Full Text Available This paper is concerned with thermal non-equilibrium natural convection in a square cavity filled with a porous medium in the presence of a biomass which is transported in the cavity. The biomass can consume a secondary moving substrate. The physics of the presented problem is related to the analysis of heat and mass transfer in a composting process that controlled by internal heat generation. The intensity of the bio-heat source generated in the cavity is equal to the rate of consumption of the substrate by the biomass. It is assumed that the porous medium is homogeneous and isotropic. A two-field model that represents the fluid and solid phase temperature fields separately is used for energy equation. A simplified Monod model is introduced along with the governing equations to describe the consumption of the substrate by the biomass. In other word, the transient biochemical heat source which is dependent on a solute concentration is considered in the energy equations. Investigation of the biomass activity and bio-chemical heat generation in the case of thermal non-equilibrium assumption has not been considered in the literature and they are open research topics. The effects of thermal non-equilibrium model on heat transfer, flow pattern and biomass transfer are investigated. The effective parameters which have a direct impact on the generated bio-chemical heat source are also presented. The influences of the non-dimensional parameters such as fluid-to-solid conductivity ratio on the temperature distribution are presented.

  5. Using Ground Source Heat Pumps for Renewable Energy

    OpenAIRE

    Xhevat BERISHA

    2017-01-01

    This paper provides background information on the current energy supply, energy demand, and energy sources in Kosovo. Moreover, it presents the country‟s current level of applying alternative energy sources. Additionally, this paper focuses on geothermal energy as a renewable energy resource with the potential to contribute to a sustainable use of resources to meet renewable energy and energy efficiency requirements of the European Union (EU), “EU 20 20 by 2020” policy. Hence, a careful analy...

  6. Energy recovery during expansion of compressed gas using power plant low-quality heat sources

    Science.gov (United States)

    Ochs, Thomas L [Albany, OR; O'Connor, William K [Lebanon, OR

    2006-03-07

    A method of recovering energy from a cool compressed gas, compressed liquid, vapor, or supercritical fluid is disclosed which includes incrementally expanding the compressed gas, compressed liquid, vapor, or supercritical fluid through a plurality of expansion engines and heating the gas, vapor, compressed liquid, or supercritical fluid entering at least one of the expansion engines with a low quality heat source. Expansion engines such as turbines and multiple expansions with heating are disclosed.

  7. Performance of water source heat pump system using high-density polyethylene tube heat exchanger wound with square copper wire

    Directory of Open Access Journals (Sweden)

    Xin Wen Zhang

    2015-07-01

    Full Text Available Surface water source heat pump system is an energy-efficient heat pump system. Surface water heat exchanger is an important part of heat pump system that can affect the performance of the system. In order to enhance the performance of the system, the overall heat transfer coefficient (U value of the water exchanger using a 32A square copper coiled high-density polyethylene tube was researched. Comparative experiments were conducted between the performance of the coiled high-density polyethylene tube and the 32A smooth high-density polyethylene tube. At the same time, the coefficient of performance of the heat pump was investigated. According to the result, the U value of the coiled tube was 18% higher than that of the smooth tube in natural convection and 19% higher in forced convection. The coefficient of performance of the heat pump with the coiled tube is higher than that with the smooth tube. The economic evaluation of the coiled tube was also investigated.

  8. Thermal performance and pressure drop of spiral-tube ground heat exchangers for ground-source heat pump

    International Nuclear Information System (INIS)

    Jalaluddin; Miyara, Akio

    2015-01-01

    Thermal performance and pressure drop of the spiral-tube GHE were evaluated in this present work. A numerical simulation tool was used to carry out this research. The heat exchange rates per meter borehole depth of the spiral-tube GHE with various pitches and their pressure drops were compared with that of the U-tube GHE. Furthermore, a comparative analysis between a spiral pipe and straight pipe was performed. In comparison with the straight pipe, using the spiral pipe in the borehole increased the heat exchange rate to the ground per meter borehole depth. However, the pressure drop of water flow also increased due to increasing the length of pipe per meter borehole depth and its spiral geometry. The accuracy of the numerical model was verified for its pressure drop with some pressure drop correlations. The heat exchange rate and pressure drop of the GHEs are presented. As an example, the heat exchange rate per meter borehole depth of spiral pipe with 0.05 m pitch in the turbulent flow increased of 1.5 times. Its pressure drop also increased of 6 times. However, from the view point of energy efficiency, using the spiral pipe in the ground-source heat pump system gives a better performance than using the straight pipe. The heat exchange rate and pressure drop are important parameter in design of the ground-source heat pump (GSHP) system. - Highlights: • Thermal performance and pressure drop of spiral-tube GHE are presented. • Effects of spiral pitch on thermal performance and pressure drop are analyzed. • Using a spiral pipe increases heat exchange rate per meter borehole depth of GHE. • Pressure drop per meter borehole depth also increases in the spiral pipe.

  9. ENERGY STAR Certified Non-AHRI Central Air Conditioner Equipment and Air Source Heat Pump

    Data.gov (United States)

    U.S. Environmental Protection Agency — Certified models meet all ENERGY STAR requirements as listed in the Version 5.0 ENERGY STAR Program Requirements for Air Source Heat Pump and Central Air Conditioner...

  10. An amplitude and phase control system for the TFTR rf heating sources

    International Nuclear Information System (INIS)

    Cutsogeorge, G.

    1989-04-01

    Feedback loops that control the amplitude and phase of the rf heating sources on TFTR are described. The method for providing arc protection is also discussed. Block diagrams and Bode plots are included. 6 figs

  11. Milliwatt-generator heat source. Progress report, January-June 1983

    International Nuclear Information System (INIS)

    Mershad, E.A.

    1983-01-01

    Progress is reported in the following: heat source shipments, reimbursable orders, hardware shipments, raw material qualification/procurement, DOE audit and milliwatt generator process review, surveillance capsule evaluations, pressure burst testing, and hardware fabrication and quality

  12. Energy well. Ground-source heat in one-family houses; Energiakaivo. Maalaemmoen hyoedyntaeminen pientaloissa

    Energy Technology Data Exchange (ETDEWEB)

    Juvonen, J.; Lapinlampi, T.

    2013-08-15

    This guide deals with the legislation, planning, building, usage and maintenance of ground-source heat systems. The guide gives recommendations and instructions on national level on the permit practices and how to carry out the whole ground-source heat system project. The main focus of the guide is on energy wells for one-family houses. The principle is that an action permit is needed to build a ground-source heat system. On ground water areas a permit according to the water act may also be required. To avoid any problems, the placement of the system needs to be planned precisely. This guide gives a comprehension to the orderer on the issues that need to be considered before ordering, during construction, when the system is running and when giving up the use of the ground-source heat system. (orig.)

  13. Material impacts and heat flux characterization of an electrothermal plasma source with an applied magnetic field

    Science.gov (United States)

    Gebhart, T. E.; Martinez-Rodriguez, R. A.; Baylor, L. R.; Rapp, J.; Winfrey, A. L.

    2017-08-01

    To produce a realistic tokamak-like plasma environment in linear plasma device, a transient source is needed to deliver heat and particle fluxes similar to those seen in an edge localized mode (ELM). ELMs in future large tokamaks will deliver heat fluxes of ˜1 GW/m2 to the divertor plasma facing components at a few Hz. An electrothermal plasma source can deliver heat fluxes of this magnitude. These sources operate in an ablative arc regime which is driven by a DC capacitive discharge. An electrothermal source was configured with two pulse lengths and tested under a solenoidal magnetic field to determine the resulting impact on liner ablation, plasma parameters, and delivered heat flux. The arc travels through and ablates a boron nitride liner and strikes a tungsten plate. The tungsten target plate is analyzed for surface damage using a scanning electron microscope.

  14. 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

  15. Entropy Generation Analysis of Natural Convection in Square Enclosures with Two Isoflux Heat Sources

    Directory of Open Access Journals (Sweden)

    S. Z. Nejad

    2017-04-01

    Full Text Available This study investigates entropy generation resulting from natural convective heat transfer in square enclosures with local heating of the bottom and symmetrical cooling of the sidewalls. This analysis tends to optimize heat transfer of two pieces of semiconductor in a square electronic package. In this simulation, heaters are modeled as isoflux heat sources and sidewalls of the enclosure are isothermal heat sinks. The top wall and the non-heated portions of the bottom wall are adiabatic. Flow and temperature fields are obtained by numerical simulation of conservation equations of mass, momentum and energy in laminar, steady and two dimensional flows. With constant heat energy into the cavity, effect of Rayleigh number, heater length, heater strength ratios and heater position is evaluated on flow and temperature fields and local entropy generation. The results show that a minimum entropy generation rate is obtained under the same condition in which a minimum peak heater temperature is obtained.

  16. Heat source component development program. Report for period March 1978--June 1978

    International Nuclear Information System (INIS)

    1978-07-01

    The General Purpose Heat Source (GPHS) is a radioisotope heat source being developed by LASL. The first intended application for the GPHS is the Solar Polar mission scheduled for 1983. Battelle's support of LASL during the current reporting period is reported. The specific efforts include: (1) analysis of trial designs with emphasis on comparison of performances of trial designs 1 and 2 and their modifications; and (2) helium vent development with emphasis on fabrication and qualification testing of platinum and iridium nonselective vents

  17. Flow Conditions in a Mechanically Ventilated Room with a Convective Heat Source

    DEFF Research Database (Denmark)

    Heiselberg, Per; Nielsen, Peter V.

    The ventilation of a test room (LxWxH = 5.4x3.6x2.4 m) with a wall mounted heat source is investigated for two different air terminal devices.......The ventilation of a test room (LxWxH = 5.4x3.6x2.4 m) with a wall mounted heat source is investigated for two different air terminal devices....

  18. On the development of an innovative gas-fired heating appliance based on a zeolite-water adsorption heat pump; system description and seasonal gas utilization efficiency

    International Nuclear Information System (INIS)

    Dawoud, Belal

    2014-01-01

    The main objective of this work is to introduce an innovative hybrid heating appliance incorporating a gas condensing boiler and a zeolite-water adsorption heat pump. The condensing boiler is applied to drive the zeolite-water heat pump for the heating base-load and to assist the heat pump in the so called “mixed operation” mode, in which both the heat pump and the condensing boiler are working in series to cover medium heating demands. Peak heating demands are covered by the condensing boiler in the so called “direct heating” mode. The three operation modes of the hybrid heating appliance have been technically described. In addition, the laboratory test conditions for estimating the seasonal heating performance according to the German Guideline VDI 4650-2 have been introduced. For both heating systems 35/28 °C and 55/45 °C, which represent the typical operating conditions of floor and high temperature radiating heating systems in Europe, seasonal heating gas utilization efficiencies of 1.34 and 1.26 have been measured, respectively with a ground heat source. In two field test installations in one-family houses in Germany, the introduced heating appliance showed 27% more seasonal gas utilization efficiency for heating and domestic hot water production, which is equivalent to a CO 2 -emission reduction of 20% compared to the gas condensing boiler technology

  19. Domestic Hot Water Production with Ground Source Heat Pump in Apartment Buildings

    Directory of Open Access Journals (Sweden)

    Jukka Yrjölä

    2015-08-01

    Full Text Available Producing domestic hot water (DHW with a ground source heat pump (GSHP is challenging due to the high temperature (HT of DHW. There are many studies proving the better performance of cascade heat pumps compared to single-stage heat pumps when the difference between the condensing and the evaporation temperature is large. In this system approach study, different GSHP arrangements are described and computationally compared. A two-stage heat pump arrangement is introduced in which water tanks of the heating system are utilized for warming up the DHW in two stages. It is shown that the electricity consumption with this two-stage system is approximately 31% less than with the single-stage heat pump and 12% less than with the cascade system. Further, both low temperature (LT and HT heat pumps can run alone, which is not common in cascade or other two-stage heat pumps. This is advantageous because the high loads of the space heating and DHW production are not simultaneous. Proper insulation of the DHW and recirculation pipe network is essential, and drying towel rails or other heating coils should be avoided when aiming for a high efficiency. The refrigerants in the calculations are R407C for the LT heat pump and R134a for the HT heat pump. Investment costs are excluded from calculations.

  20. Advanced variable speed air source integrated heat pump (AS-IHP) development - CRADA final report

    Energy Technology Data Exchange (ETDEWEB)

    Baxter, Van D. [Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States); Rice, C. Keith [Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States); Munk, Jeffrey D. [Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States); Ally, Moonis Raza [Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States); Shen, Bo [Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)

    2015-09-30

    Between August 2011 and September 2015, Oak Ridge National Laboratory (ORNL) and Nordyne, LLC (now Nortek Global HVAC LLC, NGHVAC) engaged in a Cooperative Research and Development Agreement (CRADA) to develop an air-source integrated heat pump (AS-IHP) system for the US residential market. Two generations of laboratory prototype systems were designed, fabricated, and lab-tested during 2011-2013. Performance maps for the system were developed using the latest research version of the DOE/ORNL Heat Pump Design Model, or HPDM, (Rice 1991; Rice and Jackson 2005; Shen et al 2012) as calibrated against the lab test data. These maps were the input to the TRNSYS (SOLAR Energy Laboratory, et al, 2010) system to predict annual performance relative to a baseline suite of equipment meeting minimum efficiency standards in effect in 2006 (combination of 13 SEER air-source heat pump (ASHP) and resistance water heater with Energy Factor (EF) of 0.9). Predicted total annual energy savings, while providing space conditioning and water heating for a tight, well insulated 2600 ft2 (242 m2) house at 5 U.S. locations, ranged from 46 to 61%, averaging 52%, relative to the baseline system (lowest savings at the cold-climate Chicago location). Predicted energy use for water heating was reduced 62 to 76% relative to resistance WH. Based on these lab prototype test and analyses results a field test prototype was designed and fabricated by NGHVAC. The unit was installed in a 2400 ft2 (223 m2) research house in Knoxville, TN and field tested from May 2014 to April 2015. Based on the demonstrated field performance of the AS-IHP prototype and estimated performance of a baseline system operating under the same loads and weather conditions, it was estimated that the prototype would achieve ~40% energy savings relative to the minimum efficiency suite. The estimated WH savings were >60% and SC mode savings were >50%. But estimated SH savings were only about 20%. It is believed that had the test

  1. A new method to estimate heat source parameters in gas metal arc welding simulation process

    International Nuclear Information System (INIS)

    Jia, Xiaolei; Xu, Jie; Liu, Zhaoheng; Huang, Shaojie; Fan, Yu; Sun, Zhi

    2014-01-01

    Highlights: •A new method for accurate simulation of heat source parameters was presented. •The partial least-squares regression analysis was recommended in the method. •The welding experiment results verified accuracy of the proposed method. -- Abstract: Heat source parameters were usually recommended by experience in welding simulation process, which induced error in simulation results (e.g. temperature distribution and residual stress). In this paper, a new method was developed to accurately estimate heat source parameters in welding simulation. In order to reduce the simulation complexity, a sensitivity analysis of heat source parameters was carried out. The relationships between heat source parameters and welding pool characteristics (fusion width (W), penetration depth (D) and peak temperature (T p )) were obtained with both the multiple regression analysis (MRA) and the partial least-squares regression analysis (PLSRA). Different regression models were employed in each regression method. Comparisons of both methods were performed. A welding experiment was carried out to verify the method. The results showed that both the MRA and the PLSRA were feasible and accurate for prediction of heat source parameters in welding simulation. However, the PLSRA was recommended for its advantages of requiring less simulation data

  2. Performance evaluation of a permanent ring magnet based helicon plasma source for negative ion source research

    Science.gov (United States)

    Pandey, Arun; Bandyopadhyay, M.; Sudhir, Dass; Chakraborty, A.

    2017-10-01

    Helicon wave heated plasmas are much more efficient in terms of ionization per unit power consumed. A permanent magnet based compact helicon wave heated plasma source is developed in the Institute for Plasma Research, after carefully optimizing the geometry, the frequency of the RF power, and the magnetic field conditions. The HELicon Experiment for Negative ion-I source is the single driver helicon plasma source that is being studied for the development of a large sized, multi-driver negative hydrogen ion source. In this paper, the details about the single driver machine and the results from the characterization of the device are presented. A parametric study at different pressures and magnetic field values using a 13.56 MHz RF source has been carried out in argon plasma, as an initial step towards source characterization. A theoretical model is also presented for the particle and power balance in the plasma. The ambipolar diffusion process taking place in a magnetized helicon plasma is also discussed.

  3. Magnetic pumping as a source of particle heating

    Science.gov (United States)

    Lichko, Emily; Egedal, Jan; Daughton, William; Kasper, Justin

    2017-10-01

    Magnetic pumping is a means of heating plasmas for both fusion and astrophysical applications. In this study a magnetic pumping model is developed as a possible explanation for the heating and the generation of power-law distribution functions observed in the solar wind plasma. In most previous studies turbulent energy is only dissipated at microscopic kinetic scales. In contrast, magnetic pumping energizes the particles through the largest scale turbulent fluctuations, thus bypassing the energy cascade. Kinetic simulations are applied to verify these analytic predictions. Previous results for the one-dimensional model, as well as initial results for a two-dimensional model which includes the effects of trapped and passing particles are presented. Preliminary results of the presence of this mechanism in the bow shock region, using spacecraft data from the Magnetospheric Multiscale mission, are presented as well. This research was conducted with support from National Defense Science and Engineering Graduate (NDSEG) Fellowship, 32 CFR 168, as well as from NSF Award 1404166 and NASA award NNX15AJ73G.

  4. Heat pipes as perspective base elements of heat recovery in heat supply and ventilating systems

    Directory of Open Access Journals (Sweden)

    Matveev Andrey

    2017-01-01

    Full Text Available Thermotechnical characteristics of heat pipes are considered as high-efficient heat-transfer devices, which can provide energy-saving technologies for heat supply and ventilating systems and for different branches of industry. Thermotechnical and working (”performance capability” characteristics of heat pipes are investigated. By ”performance capability” of heat pipes and heat-transfer devices on heat pipes we mean the system state, where it can perform set functions and keep parameter values (thermal power, conductivity, thermal resistance, heat-transfer coefficient, temperature level and differential, etc. within the regulations of standardized specifications. The article presents theoretical and experimental methods of «gaslock» length determination on noncondensable gases during long-lasting tests of ammonia heat pipes made of aluminum shape АS – КRА 7.5 – R1 (alloy АD – 31. The paper gives results of research of thermotechnical characteristics of heat pipes in horizontal and vertical states (separate and as a set part while using different systems of thermal insulation. The obtained results of thermotechnical and resource tests show the advantages of ammonia heat pipes as basic elements for heat exchanger design in heating and ventilation systems.

  5. Experimental performance analysis of a direct-expansion ground source heat pump in Xiangtan, China

    International Nuclear Information System (INIS)

    Yang, Wei

    2013-01-01

    The DX GSHP (direct-expansion ground source heat pump), which uses a buried copper piping network through which refrigerant is circulated, is one type of GSHP (ground source heat pump). This study investigates the performance characteristics of a vertical U-bend direct-expansion ground source (geothermal) heat pump system (DX GSHPS) for both heating and cooling. Compared with the conventional GCHP (ground coupled heat pump) system, the DX GSHP system is more efficient, with lower thermal resistance in the GHE (ground heat exchanger) and a lower (higher) condensing (evaporating) temperature in the cooling (heating) mode. In addition, the system performance of the whole DX GSHP system is also higher than that of the conventional GCHP system. A DX GSHP system in Xiangtan, China with a U-bend ground heat exchanger 42 m deep with a nominal outside diameter of 12.7 mm buried in a water well was tested and analysed. The results showed that the performance of this system is very high. The maximum (average) COPs of the system were found to be 6.08 (4.73) and 6.32 (5.03) in the heating and cooling modes, respectively. - Highlights: • The reasons for the higher performance of the DX GSHP (direct-expansion ground source heat pump) are analysed theoretically compared with the conventional GCHP (ground coupled heat pump). • The experimental performance of a DX GSHP system is investigated, which makes a valuable contribution to the literature. • The study is helpful in demonstrating the energy efficiency of the DX GSHP system

  6. Formation and variation of the atmospheric heat source over the Tibetan Plateau and its climate effects

    Science.gov (United States)

    Wu, Guoxiong; He, Bian; Duan, Anmin; Liu, Yimin; Yu, Wei

    2017-10-01

    To cherish the memory of the late Professor Duzheng YE on what would have been his 100th birthday, and to celebrate his great accomplishment in opening a new era of Tibetan Plateau (TP) meteorology, this review paper provides an assessment of the atmospheric heat source (AHS) over the TP from different data resources, including observations from local meteorological stations, satellite remote sensing data, and various reanalysis datasets. The uncertainty and applicability of these heat source data are evaluated. Analysis regarding the formation of the AHS over the TP demonstrates that it is not only the cause of the atmospheric circulation, but is also a result of that circulation. Based on numerical experiments, the review further demonstrates that land-sea thermal contrast is only one part of the monsoon story. The thermal forcing of the Tibetan-Iranian Plateau plays a significant role in generating the Asian summer monsoon (ASM), i.e., in addition to pumping water vapor from sea to land and from the lower to the upper troposphere, it also generates a subtropical monsoon-type meridional circulation subject to the angular momentum conservation, providing an ascending-air large-scale background for the development of the ASM.

  7. Personalized recommendation based on heat bidirectional transfer

    Science.gov (United States)

    Ma, Wenping; Feng, Xiang; Wang, Shanfeng; Gong, Maoguo

    2016-02-01

    Personalized recommendation has become an increasing popular research topic, which aims to find future likes and interests based on users' past preferences. Traditional recommendation algorithms pay more attention to forecast accuracy by calculating first-order relevance, while ignore the importance of diversity and novelty that provide comfortable experiences for customers. There are some levels of contradictions between these three metrics, so an algorithm based on bidirectional transfer is proposed in this paper to solve this dilemma. In this paper, we agree that an object that is associated with history records or has been purchased by similar users should be introduced to the specified user and recommendation approach based on heat bidirectional transfer is proposed. Compared with the state-of-the-art approaches based on bipartite network, experiments on two benchmark data sets, Movielens and Netflix, demonstrate that our algorithm has better performance on accuracy, diversity and novelty. Moreover, this method does better in exploiting long-tail commodities and cold-start problem.

  8. Simulation analysis on dynamic performance of a combined solar/air dual source heat pump water heater

    International Nuclear Information System (INIS)

    Deng, Weishi; Yu, Jianlin

    2016-01-01

    Highlights: • A modified direct expansion solar-assisted heat pump water heater is investigated. • An additional air source evaporator is used in parallel way in the M-DX-SHPWH system. • The M-DX-SHPWH system displays a higher performance at the low solar radiation. • Effects of solar radiation and air temperature on the performance are discussed. - Abstract: This paper investigated a combined solar/air dual source heat pump water heater system for domestic water heating application. In the dual source system, an additional air source evaporator is introduced in parallel way based on a conventional direct expansion solar-assisted heat pump water heaters (DX-SHPWH) system, which can improve the performance of the DX-SHPWH system at a low solar radiation. In the present study, a dynamic mathematical model based on zoned lump parameter approach is developed to simulate the performance of the system (i.e. a modified DX-SHPWH (M-DX-SHPWH) system). Using the model, the performance of M-DX-SHPWH system is evaluated and then compared with that of the conventional DX-SHPWH system. The simulation results show the M-DX-SHPWH system has a better performance than that of the conventional DX-SHPWH system. At a low solar radiation of 100 W/m"2, the heating time of the M-DX-SHPWH decreases by 19.8% compared to the DX-SHPWH when water temperature reaches 55 °C. Meanwhile, the COP on average increases by 14.1%. In addition, the refrigerant mass flow rate distribution in the air source evaporator and the solar collector of the system, the allocation between the air source evaporator and the solar collector areas and effects of solar radiation and ambient air temperature on the system performance are discussed.

  9. Performance Analysis of Slinky Horizontal Ground Heat Exchangers for a Ground Source Heat Pump System

    Directory of Open Access Journals (Sweden)

    Md. Hasan Ali

    2017-10-01

    Full Text Available This paper highlights the thermal performance of reclined (parallel to ground surface and standing (perpendicular to ground surface slinky horizontal ground heat exchangers (HGHEs with different water mass flow rates in the heating mode of continuous and intermittent operations. A copper tube with an outer surface protected with low-density polyethylene was selected as the tube material of the ground heat exchanger. Effects on ground temperature around the reclined slinky HGHE due to heat extraction and the effect of variation of ground temperatures on reclined HGHE performance are discussed. A higher heat exchange rate was experienced in standing HGHE than in reclined HGHE. The standing HGHE was affected by deeper ground temperature and also a greater amount of backfilled sand in standing HGHE (4.20 m3 than reclined HGHE (1.58 m3, which has higher thermal conductivity than site soil. For mass flow rate of 1 L/min with inlet water temperature 7 °C, the 4-day average heat extraction rates increased 45.3% and 127.3%, respectively, when the initial average ground temperatures at 1.5 m depth around reclined HGHE increased from 10.4 °C to 11.7 °C and 10.4 °C to 13.7 °C. In the case of intermittent operation, which boosted the thermal performance, a short time interval of intermittent operation is better than a long time interval of intermittent operation. Furthermore, from the viewpoint of power consumption by the circulating pump, the intermittent operation is more efficient than continuous operation.

  10. Milk of the cow as a source [for heat pumps]; Koe als bronsysteem

    Energy Technology Data Exchange (ETDEWEB)

    Roestenberg, B.

    2012-09-15

    A livestock farm in Joure, the Netherlands, has designed a heat pump system that uses milk as a source. Up to now, three livestock farms in the Netherlands have been equipped with the so-called ECO2000 system that extracts heat from milk, using a heat pump to use this heat elsewhere in the business [Dutch] Een veeteeltbedrijf in Joure, Nederland, heeft een warmtepompsysteem ontworpen dat melk gebruikt als bron. Inmiddels zijn drie melkveehouderijen in Nederland voorzien van het zogenaamde ECO2000 systeem waarbij warmte wordt onttrokken uit melk om via een warmtepomp elders in het bedrijf te worden hergebruikt.

  11. Experimental investigation on water quality standard of Yangtze River water source heat pump.

    Science.gov (United States)

    Qin, Zenghu; Tong, Mingwei; Kun, Lin

    2012-01-01

    Due to the surface water in the upper reaches of Yangtze River in China containing large amounts of silt and algae, high content of microorganisms and suspended solids, the water in Yangtze River cannot be used for cooling a heat pump directly. In this paper, the possibility of using Yangtze River, which goes through Chongqing, a city in southwest China, as a heat source-sink was investigated. Water temperature and quality of the Yangtze River in the Chongqing area were analyzed and the performance of water source heat pump units in different sediment concentrations, turbidity and algae material conditions were tested experimentally, and the water quality standards, in particular surface water conditions, in the Yangtze River region that adapt to energy-efficient heat pumps were also proposed. The experimental results show that the coefficient of performance heat pump falls by 3.73% to the greatest extent, and the fouling resistance of cooling water in the heat exchanger increases up to 25.6% in different water conditions. When the sediment concentration and the turbidity in the river water are no more than 100 g/m3 and 50 NTU respectively, the performance of the heat pump is better, which can be used as a suitable river water quality standard for river water source heat pumps.

  12. A flexible and low cost experimental stand for air source heat pump for Smart Buildings

    DEFF Research Database (Denmark)

    Crăciun, Vasile S.; Bojesen, Carsten; Blarke, Morten

    2012-01-01

    Energy systems are faced with the challenges of reducing dependency on fossil fuels, while handling increasing penetration levels of intermittent renewables such as wind and solar power. At the same time, the efficient consumption of energy is vital for avoiding the impacts from increasing fuel...... prices. A significant part of this challenge may be dealt with in the way space heating, space cooling, and domestic hot water production which is provided to residential and commercial buildings. Air source heat pumps (ASHP) are widely used conversion technologies for providing building thermal energy...... services; cooling, heating, and water heating. ASHP does not have a constant temperature for the primary source like: soil, ground water, or surface water heat pumps. In result, laboratory experiments and tests are faced by the problem of having to handle a wide range of conditions under which...

  13. Mixed convection from a discrete heat source in enclosures with two adjacent moving walls and filled with micropolar nanofluids

    Directory of Open Access Journals (Sweden)

    Sameh E. Ahmed

    2016-03-01

    Full Text Available This paper examines numerically the thermal and flow field characteristics of the laminar steady mixed convection flow in a square lid-driven enclosure filled with water-based micropolar nanofluids by using the finite volume method. While a uniform heat source is located on a part of the bottom of the enclosure, both the right and left sidewalls are considered adiabatic together with the remaining parts of the bottom wall. The upper wall is maintained at a relatively low temperature. Both the upper and left sidewalls move at a uniform lid-driven velocity and four different cases of the moving lid ordinations are considered. The fluid inside the enclosure is a water based micropolar nanofluid containing different types of solid spherical nanoparticles: Cu, Ag, Al2O3, and TiO2. Based on the numerical results, the effects of the dominant parameters such as Richardson number, nanofluid type, length and location of the heat source, solid volume fractions, moving lid orientations and dimensionless viscosity are examined. Comparisons with previously numerical works are performed and good agreements between the results are observed. It is found that the average Nusselt number along the heat source decreases as the heat source length increases while it increases when the solid volume fraction increases. Also, the results of the present study indicate that both the local and the average Nusselt numbers along the heat source have the highest value for the fourth case (C4. Moreover, it is observed that both the Richardson number and moving lid ordinations have a significant effect on the flow and thermal fields in the enclosure.

  14. Large-eddy simulation of convective boundary layer generated by highly heated source with open source code, OpenFOAM

    International Nuclear Information System (INIS)

    Hattori, Yasuo; Suto, Hitoshi; Eguchi, Yuzuru; Sano, Tadashi; Shirai, Koji; Ishihara, Shuji

    2011-01-01

    Spatial- and temporal-characteristics of turbulence structures in the close vicinity of a heat source, which is a horizontal upward-facing round plate heated at high temperature, are examined by using well resolved large-eddy simulations. The verification is carried out through the comparison with experiments: the predicted statistics, including the PDF distribution of temperature fluctuations, agree well with measurements, indicating that the present simulations have a capability to appropriately reproduce turbulence structures near the heat source. The reproduced three-dimensional thermal- and fluid-fields in the close vicinity of the heat source reveals developing processes of coherence structures along the surface: the stationary- and streaky-flow patterns appear near the edge, and such patterns randomly shift to cell-like patterns with incursion into the center region, resulting in thermal-plume meandering. Both the patterns have very thin structures, but the depth of streaky structure is considerably small compared with that of cell-like patterns; this discrepancy causes the layered structures. The structure is the source of peculiar turbulence characteristics, the prediction of which is quite difficult with RANS-type turbulence models. The understanding such structures obtained in present study must be helpful to improve the turbulence model used in nuclear engineering. (author)

  15. Thermoeconomic Evaluation of Modular Organic Rankine Cycles for Waste Heat Recovery over a Broad Range of Heat Source Temperatures and Capacities

    Directory of Open Access Journals (Sweden)

    Markus Preißinger

    2017-02-01

    Full Text Available Industrial waste heat recovery by means of an Organic Rankine Cycle (ORC can contribute to the reduction of CO2 emissions from industries. Before market penetration, high efficiency modular concepts have to be developed to achieve appropriate economic value for industrial decision makers. This paper aims to investigate modularly designed ORC systems from a thermoeconomic point of view. The main goal is a recommendation for a suitable chemical class of working fluids, preferable ORC design and a range of heat source temperatures and thermal capacities in which modular ORCs can be economically feasible. For this purpose, a thermoeconomic model has been developed which is based on size and complexity parameters of the ORC components. Special emphasis has been laid on the turbine model. The paper reveals that alkylbenzenes lead to higher exergetic efficiencies compared to alkanes and siloxanes. However, based on the thermoeconomic model, the payback periods of the chemical classes are almost identical. With the ORC design, the developed model and the boundary conditions of this study, hexamethyldisiloxane is a suitable working fluid and leads to a payback period of less than 5 years for a heat source temperature of 400 to 600 °C and a mass flow rate of the gaseous waste heat stream of more than 4 kg/s.

  16. Preliminary design study of an alternate heat source assembly for a Brayton isotope power system

    Science.gov (United States)

    Strumpf, H. J.

    1978-01-01

    Results are presented for a study of the preliminary design of an alternate heat source assembly (HSA) intended for use in the Brayton isotope power system (BIPS). The BIPS converts thermal energy emitted by a radioactive heat source into electrical energy by means of a closed Brayton cycle. A heat source heat exchanger configuration was selected and optimized. The design consists of a 10 turn helically wound Hastelloy X tube. Thermal analyses were performed for various operating conditions to ensure that post impact containment shell (PICS) temperatures remain within specified limits. These limits are essentially satisfied for all modes of operation except for the emergency cooling system for which the PICS temperatures are too high. Neon was found to be the best choice for a fill gas for auxiliary cooling system operation. Low cycle fatigue life, natural frequency, and dynamic loading requirements can be met with minor modifications to the existing HSA.

  17. Thermodynamic analysis of a low-temperature waste heat recovery system based on the concept of solar chimney

    International Nuclear Information System (INIS)

    Chen, Kai; Wang, Jiangfeng; Dai, Yiping; Liu, Yuqi

    2014-01-01

    Highlights: • A low grade waste heat recovery system based on the concept of solar chimney is proposed. • The effects of three key factors on the system performance are examined. • Thermodynamics analysis is to find a better way to utilize low grade heat source efficiently. - Abstract: The utilization of low-temperature waste heat draws more and more attention due to serious energy crisis nowadays. This paper proposes a low-temperature waste heat recovery system based on the concept of solar chimney. In the system, low-temperature waste heat is used to heat air to produce an air updraft in the chimney tower. The air updraft propels a turbine fixed at the base of the chimney tower to convert waste heat into electricity. The mathematical model of the system is established based on first law and second law of thermodynamics. Hot water is selected as the representative of low-temperature waste heat sources for researching. The heat source temperature, ambient air temperature and area of heat transfer are examined to evaluate their effects on the system performance such as velocity of updraft, mass flow rate of air, power output, conversion efficiency, and exergy efficiency. The velocity of air demonstrates a better stability than the mass flow rate of air and the pressure difference when temperature of heat source, ambient air temperature or area of heat transfer changes

  18. A One-Source Approach for Estimating Land Surface Heat Fluxes Using Remotely Sensed Land Surface Temperature

    Directory of Open Access Journals (Sweden)

    Yongmin Yang

    2017-01-01

    Full Text Available The partitioning of available energy between sensible heat and latent heat is important for precise water resources planning and management in the context of global climate change. Land surface temperature (LST is a key variable in energy balance process and remotely sensed LST is widely used for estimating surface heat fluxes at regional scale. However, the inequality between LST and aerodynamic surface temperature (Taero poses a great challenge for regional heat fluxes estimation in one-source energy balance models. To address this issue, we proposed a One-Source Model for Land (OSML to estimate regional surface heat fluxes without requirements for empirical extra resistance, roughness parameterization and wind velocity. The proposed OSML employs both conceptual VFC/LST trapezoid model and the electrical analog formula of sensible heat flux (H to analytically estimate the radiometric-convective resistance (rae via a quartic equation. To evaluate the performance of OSML, the model was applied to the Soil Moisture-Atmosphere Coupling Experiment (SMACEX in United States and the Multi-Scale Observation Experiment on Evapotranspiration (MUSOEXE in China, using remotely sensed retrievals as auxiliary data sets at regional scale. Validated against tower-based surface fluxes observations, the root mean square deviation (RMSD of H and latent heat flux (LE from OSML are 34.5 W/m2 and 46.5 W/m2 at SMACEX site and 50.1 W/m2 and 67.0 W/m2 at MUSOEXE site. The performance of OSML is very comparable to other published studies. In addition, the proposed OSML model demonstrates similar skills of predicting surface heat fluxes in comparison to SEBS (Surface Energy Balance System. Since OSML does not require specification of aerodynamic surface characteristics, roughness parameterization and meteorological conditions with high spatial variation such as wind speed, this proposed method shows high potential for routinely acquisition of latent heat flux estimation

  19. Thermal energy storage system using phase change materials: Constant heat source

    Directory of Open Access Journals (Sweden)

    Reddy Meenakshi R.

    2012-01-01

    Full Text Available The usage of phase change materials (PCM to store the heat in the form of latent heat is increased, because large quantity of thermal energy is stored in smaller volumes. In the present experimental investigation paraffin and stearic acid are employed as PCMs in thermal energy storage (TES system to store the heat as sensible and latent heat also. A constant heat source is used to supply heat transfer fluid (HTF at constant temperature to the TES system. In the TES system PCMs are stored in the form of spherical capsules of 38 mm diameter made of high density poly ethylene (HDPE. The results of the investigation are related to the charging time and recovery of stored energy from the TES system.

  20. Dynamics of charged bulk viscous collapsing cylindrical source with heat flux

    Energy Technology Data Exchange (ETDEWEB)

    Shah, S.M.; Abbas, G. [The Islamia University of Bahawalpur, Department of Mathematics, Bahawalpur (Pakistan)

    2017-04-15

    In this paper, we have explored the effects of dissipation on the dynamics of charged bulk viscous collapsing cylindrical source which allows the out-flow of heat flux in the form of radiations. The Misner-Sharp formalism has been implemented to drive the dynamical equation in terms of proper time and radial derivatives. We have investigated the effects of charge and bulk viscosity on the dynamics of collapsing cylinder. To determine the effects of radial heat flux, we have formulated the heat transport equations in the context of Mueller-Israel-Stewart theory by assuming that thermodynamics viscous/heat coupling coefficients can be neglected within some approximations. In our discussion, we have introduced the viscosity by the standard (non-causal) thermodynamics approach. The dynamical equations have been coupled with the heat transport equation; the consequences of the resulting coupled heat equation have been analyzed in detail. (orig.)

  1. Nonlinear radiated MHD flow of nanoliquids due to a rotating disk with irregular heat source and heat flux condition

    Science.gov (United States)

    Mahanthesh, B.; Gireesha, B. J.; Shehzad, S. A.; Rauf, A.; Kumar, P. B. Sampath

    2018-05-01

    This research is made to visualize the nonlinear radiated flow of hydromagnetic nano-fluid induced due to rotation of the disk. The considered nano-fluid is a mixture of water and Ti6Al4V or AA7072 nano-particles. The various shapes of nanoparticles like lamina, column, sphere, tetrahedron and hexahedron are chosen in the analysis. The irregular heat source and nonlinear radiative terms are accounted in the law of energy. We used the heat flux condition instead of constant surface temperature condition. Heat flux condition is more relativistic and according to physical nature of the problem. The problem is made dimensionless with the help of suitable similarity constraints. The Runge-Kutta-Fehlberg scheme is adopted to find the numerical solutions of governing nonlinear ordinary differential systems. The solutions are plotted by considering the various values of emerging physical constraints. The effects of various shapes of nanoparticles are drawn and discussed.

  2. An inductively heated hot cavity catcher laser ion source

    CERN Document Server

    Reponen, M; Pohjalainen, I; Rothe, S; Savonen, M; Sonnenschein, V; Voss, A

    2015-01-01

    An inductively heated hot cavity catcher has been constructed for the production of low-energy ion beams of exotic, neutron-deficient Agisotopes. A proof-of-principle experiment has been realized by implanting primary 107Ag21+ ions from a heavy-ion cyclotron into a graphite catcher. A variable-thickness nickel foil was used to degrade the energy of the primary beam in order to mimic the implantation depth expected from the heavy-ion fusion-evaporation recoils of N = Z94Ag. Following implantation, the silver atoms diffused out of the graphite and effused into the catcher cavity and transfer tube, where they were resonantly laser ionized using a three-step excitation and ionization scheme. Following mass separation, the ions were identified by scanning the frequency of the first resonant excitation step while recording the ion count rate. Ion release time profiles were measured for different implantation depths and cavity temperatures with the mean delay time varying from 10 to 600 ms. In addition, the diffusio...

  3. Modeling tectonic heat flow and source rock maturity in the Rub' Al-Khali Basin (Saudi Arabia), with the help of GOCE satellite gravity data

    NARCIS (Netherlands)

    Abdul Fattah, R.; Meekes, S.; Bouman, J.; Ebbing, J.; Haagmans, R.

    2014-01-01

    A 3D basin modeling study was carried out to reconstruct the regional heat flow and source rock maturity in the Rub'al-Khali basin. Gravity gradient data from the GOCE satellite were used to model deep structures, such as the Moho interface. Tectonic heat flow was modeled using the GOCE-based Moho

  4. Residential home heating: The potential for air source heat pump technologies as an alternative to solid and liquid fuels

    International Nuclear Information System (INIS)

    Kelly, J. Andrew; Fu, Miao; Clinch, J. Peter

    2016-01-01

    International commitments on greenhouse gases, renewables and air quality warrant consideration of alternative residential heating technologies. The residential sector in Ireland accounts for approximately 25% of primary energy demand with roughly half of primary home heating fuelled by oil and 11% by solid fuels. Displacing oil and solid fuel usage with air source heat pump (ASHP) technology could offer household cost savings, reductions in emissions, and reduced health impacts. An economic analysis estimates that 60% of homes using oil, have the potential to deliver savings in the region of €600 per annum when considering both running and annualised capital costs. Scenario analysis estimates that a grant of €2400 could increase the potential market uptake of oil users by up to 17% points, whilst a higher oil price, similar to 2013, could further increase uptake from heating oil users by 24% points. Under a combined oil-price and grant scenario, CO_2 emissions reduce by over 4 million tonnes per annum and residential PM_2_._5 and NO_X emissions from oil and peat reduce close to zero. Corresponding health and environmental benefits are estimated in the region of €100m per annum. Sensitivity analyses are presented assessing the impact of alternate discount rates and technology performance. This research confirms the potential for ASHP technology and identifies and informs policy design considerations with regard to oil price trends, access to capital, targeting of grants, and addressing transactions costs. - Highlights: • Air Source Heat Pumps can offer substantial savings over oil fired central heating. • Significant residential air and climate emission reductions are possible. • Associated health and environmental benefits are estimated up to €100m per annum. • Results can inform policy interventions in the residential market to support change.

  5. Fuel-efficiency of hydrogen and heat storage technologies for integration of fluctuating renewable energy sources

    DEFF Research Database (Denmark)

    Mathiesen, Brian Vad; Lund, Henrik

    2005-01-01

    This paper presents the methodology and results of analysing the use of different energy storage technologies in the task of integration of fluctuating renewable energy sources (RES) into the electricity supply. The analysis is done on the complete electricity system including renewable energy...... sources as well as power plants and CHP (Combined heat and power production). Emphasis is put on the need for ancillary services. Devices to store electricity as well as devices to store heat can be used to help the integration of fluctuating sources. Electricity storage technologies can be used...... to relocate electricity production directly from the sources, while heat storage devices can be used to relocate the electricity production from CHP plants and hereby improve the ability to integrate RES. The analyses are done by advanced computer modelling and the results are given as diagrams showing...

  6. GIS based analysis of future district heating potential in Denmark

    DEFF Research Database (Denmark)

    Nielsen, Steffen; Möller, Bernd

    2013-01-01

    in Denmark have been mapped in a heat atlas which includes all buildings and their heat demands. This article focuses on developing a method for assessing the costs associated with supplying these buildings with DH. The analysis is based on the existing DH areas in Denmark. By finding the heat production...

  7. Control strategy and experimental study on a novel defrosting method for air-source heat pump

    International Nuclear Information System (INIS)

    Liang Caihua; Zhang Xiaosong; Li Xiuwei; Chen Zhenqian

    2010-01-01

    A new defrosting method - the sensible heat defrosting method, aiming at shelving the various disadvantages of the conventional reverse cycle defrosting was proposed in this paper. The mechanism and process of this method was analysed. To guarantee the reliability, the self-organizing control algorithm with self-learning function was introduced based on the cardinal fuzzy control algorithm. Moreover, the control strategy was enacted; the corresponding self-organizing fuzzy control system was developed; the Micro Controller Unit (MCU) based control unit was accomplished; and the experimental study was conducted to investigate the sample machine of air-source heat pump system. The results of the experiments showed that the self-organizing control algorithm has good control characteristic and effect. On one hand, the adverse shock from the conventional reverse cycle defrosting to the refrigeration system could be avoided through this proposed method; on the other hand, the 'oil rush' could also be eliminated. Besides, the thermal comfort could be greatly improved since the temperature fluctuation range of the supplied water is narrowed by applying this new method in practice.

  8. Analysis of the Potential of Low-Temperature Heat Pump Energy Sources

    Directory of Open Access Journals (Sweden)

    Pavel Neuberger

    2017-11-01

    Full Text Available The paper deals with an analysis of temperatures of ground masses in the proximities of linear and slinky-type HGHE (horizontal ground heat exchanger. It evaluates and compares the potentials of HGHEs and ambient air. The reason and aim of the verification was to gain knowledge of the temperature course of the monitored low-temperature heat pump energy sources during heating periods and periods of stagnation and to analyse the knowledge in terms of the potential to use those sources for heat pumps. The study was conducted in the years 2012–2015 during three heating periods and three periods of HGHEs stagnation. The results revealed that linear HGHE had the highest temperature potential of the observed low-temperature heat pump energy sources. The average daily temperatures of the ground mass surrounding the linear HGHE were the highest ranging from 7.08 °C to 9.20 °C during the heating periods, and having the lowest temperature variation range of 12.62–15.14 K, the relative frequency of the average daily temperatures of the ground mass being the highest at 22.64% in the temperature range containing the mode of all monitored temperatures in a recorded interval of [4.10, 6.00] °C. Ambient air had lower temperature potential than the monitored HGHEs.

  9. Technical assessment of electric heat boosters in low-temperature district heating based on combined heat and power analysis

    DEFF Research Database (Denmark)

    Cai, Hanmin; You, Shi; Wang, Jiawei

    2018-01-01

    This paper provides a technical assessment of electric heat boosters (EHBs) in low-energy districts. The analysis is based on a hypothetical district with 23 terraced single-family houses supplied by both a lowtemperature district heating (LTDH) network and a low-voltage network (LVN). Two case...

  10. Earliest Deadline Control of a Group of Heat Pumps with a Single Energy Source

    Directory of Open Access Journals (Sweden)

    Jiří Fink

    2016-07-01

    Full Text Available In this paper, we develop and investigate the optimal control of a group of 104 heat pumps and a central Combined Heat and Power unit (CHP. The heat pumps supply space heating and domestic hot water to households. Each house has a buffer for domestic hot water and a floor heating system for space heating. Electricity for the heat pumps is generated by a central CHP unit, which also provides thermal energy to a district heating system. The paper reviews recent smart grid control approaches for central and distributed levels. An online algorithm is described based on the earliest deadline first theory that can be used on the aggregator level to control the CHP and to give signals to the heat pump controllers if they should start or should wait. The central controller requires only a limited amount of privacy-insensitive information from the heat pump controllers about their deadlines, which the heat pump controllers calculate for themselves by model predictions. In this way, a robust heat pump and CHP control is obtained, which is able to minimize energy demand and results in the desired thermal comfort for the households. The simulations demonstrate fast computation times due to minor computational and communication overheads.

  11. Meeting Czechoslovak demands for heat in long-term prospective, especially with regard to nuclear sources

    International Nuclear Information System (INIS)

    Klail, M.

    1988-01-01

    The development was studied of heat demand in the CSSR till the year 2030. The ratio of centralized and decentralized heat supply is currently 60 to 40; in the future a slight increase is expected in the decentralized type of heat supply, mainly as a result of more intensive use of natural gas. In 2030, 710 PU of centralized heat should be produced. A decisive element in meeting the demand will be a growing proportion of combined production of electric power and heat by nuclear power plants. The installed capacity of the nuclear power plants in 2030 should range between 23 and 41 thousand MW, the production of electric power in these plants should be 193 to 238 TWh/y. 109 territorial areas potentially suitable for use of heat from nuclear sources were selected. They were included in 19 regions of which 9 should in the year 2010 be linked to heat supply from nuclear power plants that will be in operation. It is expected that in the year 2030, nuclear sources will supply 250 PU of centralized heat. (Z.M.). 2 tabs., 14 refs

  12. The study of the heat-engineering characteristics of a solar heat collector based on aluminum heat pipes

    International Nuclear Information System (INIS)

    Khairnasov, S.M.; Zaripov, V.K.; Passamakin, B.M. et al.

    2013-01-01

    This paper presents the results of studies into the heat-engineering characteristics of a flat heat solar collector based on aluminum heat pipes that is designed to be used in building facades. The principle of work and the structure of the solar collector are considered; the results of its comparison with a traditional flat solar collector are presented. The studies were performed at a heat carrier temperature range of +10 - +30 degree C and at a solar heat flow density of 400 - 1000 W/m 2 . The obtained experimental heat-engineering characteristics of the collector based on heat pipes show that they are at a level of traditional flow solar collectors; for example, its efficiency is 0.65 - 0.73. Meanwhile, the hydraulic resistance of the structure with heat pipes is by a factor of 2 - 2.4 smaller and ensures a high level of scalability, reliability, and maintainability, which is important when using it as an element of facade constructions of solar heat systems. (author)

  13. Consideration of ultra-high temperature nuclear heat sources for MHD conversion systems

    International Nuclear Information System (INIS)

    Holman, R.R.; Tobin, J.M.; Young, W.E.

    1975-01-01

    The nuclear technology reactors developed and tested in the Nuclear Engine Rocket Vehicle Application (NERVA) program operated with fuel exit gas temperatures in excess of 2600 K. This experience provided a significant ultra-high temperature technology base and design insight for commercial power applications. Design approaches to accommodate fission product retention and other key prevailing requirements are examined in view of the basic overriding functional requirements, and some interesting reconsiderations are suggested. Predicted overall system performance potentials for a 2000 K MHD conversion system and reactor parameter requirements are compared and related to existing technology status. Needed verification and development efforts are suggested. A reconsideration of basic design approaches is suggested that could open the door for immediate development of ultrahigh temperature nuclear heat sources for advanced energy systems

  14. Plastic waste depolymerization as a source of energetic heating oils

    Directory of Open Access Journals (Sweden)

    Wołosiewicz-Głąb Marta

    2017-01-01

    Full Text Available In the past years there has been an increase in production and consumption of plastics, which are widely used in many areas of life. Waste generated from this material are a challenge for the whole of society, regardless of awareness of sustainable development and its technological progress. Still the method of disposal of plastic waste are focused mainly on their storage and incineration, not using energy contained there. In this paper technology for plastic waste depolymerization with characteristics of fuel oil resulting in the process, as an alternative to traditional energy carriers such as: coal, fine coal or coke used in households will be presented. Oil has a high calorific value and no doubt could replace traditional solutions which use conventional energy sources. Furthermore, the fuel resulting from this process is sulfur-free and chemically pure. The paper presents the installation for plastics waste depolymerization used in selected Polish Institute of Plastics Processing, along with the ability to use the main thermocatalytic transformation product.

  15. An Open-Source Based ITS Platform

    DEFF Research Database (Denmark)

    Andersen, Ove; Krogh, Benjamin Bjerre; Torp, Kristian

    2013-01-01

    In this paper, a complete platform used to compute travel times from GPS data is described. Two approaches to computing travel time are proposed one based on points and one based on trips. Overall both approaches give reasonable results compared to existing manual estimated travel times. However......, the trip-based approach requires more GPS data and of a higher quality than the point-based approach. The platform has been completely implemented using open-source software. The main conclusion is that large quantity of GPS data can be managed, with a limited budget and that GPS data is a good source...... for estimating travel times, if enough data is available....

  16. Humans as a Source of Heat and Air Pollution

    DEFF Research Database (Denmark)

    Hyldgård, Carl-Erik

    This is the first part of a planned research into the effect of the human being on the indoor climate. The results are among other things intended for CFD calculations. This part deals with the influence from breathing, smoking, bioeffluents and vapour. The results are mainly based on measurement...

  17. Atopic dermatitis and indoor use of energy sources in cooking and heating appliances

    Directory of Open Access Journals (Sweden)

    Vicedo-Cabrera Ana M

    2012-10-01

    Full Text Available Abstract Background Atopic dermatitis (AD prevalence has considerably increased worldwide in recent years. Studying indoor environments is particularly relevant, especially in industrialised countries where many people spend 80% of their time at home, particularly children. This study is aimed to identify the potential association between AD and the energy source (biomass, gas and electricity used for cooking and domestic heating in a Spanish schoolchildren population. Methods As part of the ISAAC (International Study of Asthma and Allergies in Childhood phase III study, a cross-sectional population-based survey was conducted with 21,355 6-to-7-year-old children from 8 Spanish ISAAC centres. AD prevalence, environmental risk factors and the use of domestic heating/cooking devices were assessed using the validated ISAAC questionnaire. Crude and adjusted odds ratios (cOR, aOR and 95% confidence intervals (CIs were obtained. A logistic regression analysis was performed (Chi-square test, p-value  Results It was found that the use of biomass systems gave the highest cORs, but only electric cookers showed a significant cOR of 1.14 (95% CI: 1.01-1.27. When the geographical area and the mother’s educational level were included in the logistic model, the obtained aOR values differed moderately from the initial cORs. Electric heating was the only type which obtained a significant aOR (1.13; 95% CI: 1.00-1.27. Finally, the model with all selected confounding variables (sex, BMI, number of siblings, mother’s educational level, smoking habits of parents, truck traffic and geographical area, showed aOR values which were very similar to those obtained in the previous adjusted logistic analysis. None of the results was statistically significant, but the use of electric heating showed an aOR close to significance (1.14; 95% CI: 0.99-1.31. Conclusion In our study population, no statistically significant associations were found between the type of indoor

  18. Viscoelastic Fluid over a Stretching Sheet with Electromagnetic Effects and Nonuniform Heat Source/Sink

    Directory of Open Access Journals (Sweden)

    Kai-Long Hsiao

    2010-01-01

    Full Text Available A magnetic hydrodynamic (MHD of an incompressible viscoelastic fluid over a stretching sheet with electric and magnetic dissipation and nonuniform heat source/sink has been studied. The buoyant effect and the electric number E1 couple with magnetic parameter M to represent the dominance of the electric and magnetic effects, and adding the specific item of nonuniform heat source/sink is presented in governing equations which are the main contribution of this study. The similarity transformation, the finite-difference method, Newton method, and Gauss elimination method have been used to analyze the present problem. The numerical solutions of the flow velocity distributions, temperature profiles, and the important wall unknown values of f''(0 and θ'(0 have been carried out. The parameter Pr, E1, or Ec can increase the heat transfer effects, but the parameter M or A* may decrease the heat transfer effects.

  19. Analysis of Fuel Cell Driven Ground Source Heat Pump Systems in Community Buildings

    Directory of Open Access Journals (Sweden)

    Jong-Keun Shin

    2013-05-01

    Full Text Available In the present study, a fuel cell driven ground source heat pump (GSHP system is applied in a community building and heat pump system performance is analyzed by computational methods. Conduction heat transfer between the brine pipe and ground is analyzed by TEACH code in order to predict the performance of the heat pump system. The predicted coefficient of performance (COP of the heat pump system and the energy cost were compared with the variation of the location of the objective building, the water saturation rate of the soil, and the driven powers of the heat pump system. Compared to the late-night electricity driven system, a significant reduction of energy cost can be accomplished by employing the fuel cell driven heat pump system. This is due to the low cost of electricity production of the fuel cell system and to the application of the recovered waste heat generated during the electricity production process to the heating of the community building.

  20. A parametric study of a humidification dehumidification (HDH) desalination system using low grade heat sources

    International Nuclear Information System (INIS)

    He, W.F.; Han, D.; Yue, C.; Pu, W.H.

    2015-01-01

    Highlights: • The HDH desalination system coupling with the waste heat plate LGHC is proposed. • Performance of the desalination system and the plate LGHC is presented. • Influence from the operation pressure on the system performance is investigated. • Gained investment ratio is proposed to characterize the desalination system consumption. - Abstract: Humidification dehumidification (HDH) desalination system is applicable to recover the low grade heat source to heat the seawater before the humidifier. In the paper, plate heat exchangers are integrated to recover the waste heat from the exhaust in the water heated closed air open water (CAOW) HDH desalination system. The performance of the HDH desalination system as well as the plate type of low grade heat collector (LGHC) is investigated at different operation pressures. Gain investment ratio (GIR) is proposed and defined to depict the overall consumption of the whole system. The simulation results show that the modified heat capacity ratio of the dehumidifier (HCRd) is vital for the performance of the HDH desalination system as well as the plate LGHC with a top value of gain output ratio (GOR) at the balance point, HCRd = 1, and the maximum GOR, GOR = 2.44, results from the raised pressure of p = 0.15 MPa. Furthermore, taking the cost for the heat transfer surface area of the LGHC and the air and seawater pipes into consideration, it is revealed that the conditions, HCRd > 1, are more economical due to the increase of GIR, which indicates the profit of unit consumption is more significant.

  1. Increase of COP for heat transformer in water purification systems. Part II - Without increasing heat source temperature

    International Nuclear Information System (INIS)

    Romero, R.J.; Siqueiros, J.; Huicochea, A.

    2007-01-01

    The integration of a water purification system allows a heat transformer to increase the actual coefficient of performance, by the reduction of the amount of heat supplied by unit of heat. A new defined COP called COP WP is proposed for the present system, which considers the fraction of heat recycled. Simulation with proven software compares the performance of the modeling of an absorption heat transformer for water purification (AHTWP) operating with water/lithium bromide, as working fluid-absorbent pair. Plots of enthalpy-based coefficients of performance (COP ET ) and water purification coefficient of performance (COP WP ) are shown against absorber temperature for several thermodynamic operating conditions. The results showed that the proposed (AHTWP) system is capable of increasing the original value of COP ET up to 1.6 times its original value by recycling energy from a water purification system. The proposed COP WP allows increments for COP values from any experimental data for water purification or for any other distillation system integrated to a heat transformer, regardless of actual COP A value or working fluid-absorbent pair

  2. An accelerator based steady state neutron source

    International Nuclear Information System (INIS)

    Burke, R.J.; Johnson, D.L.

    1985-01-01

    Using high current, c.w. linear accelerator technology, a spallation neutron source can achieve much higher average intensities than existing or proposed pulsed spallation sources. With about 100 mA of 300 MeV protons or deuterons, the Accelerator Based Neutron Research Facility (ABNR) would initially achieve the 10 16 n/cm 2 .s thermal flux goal of the advanced steady state neutron source, and upgrading could provide higher steady state fluxes. The relatively low ion energy compared to other spallation sources has an important impact on R and D requirements as well as capital cost, for which a range of $300-450M is estimated by comparison to other accelerator-based neutron source facilities. The source is similar to a reactor source in most respects. It has some higher energy neutrons but fewer gamma rays, and the moderator region is free of many of the design constraints of a reactor, which helps to implement sources for various neutron energy spectra, many beam tubes, etc. With the development of multi-beam concept and the basis for currents greater than 100 mA that is assumed in the R and D plan, the ABNR would serve many additional uses, such as fusion materials development, production of proton-rich isotopes, and other energy and defense program needs

  3. Study of radiation heating (part 1). UR spectroscopic characteristics of radiant heat source

    Energy Technology Data Exchange (ETDEWEB)

    Nagaoka, Yoshikazu; Ajisaka, Kazuhiro; Toyonaga, Hajime; Kitahata, Hiroki; Oshida, Shun' ichi; Sugihara, Tomonori

    1987-09-01

    There are many IR permeable substances. When this is heated with IR beam, UR beam penetrated into the substance and heat up the substance from the inside. In this case, the inside gets hot quicker than the surface which gives much difference in the finish of the product. Characteristics of permeation and absorption of the IR beam vary by the type of the substance and the wave-length of the UR beam. Examples of effectiveness of far infra-red heater are: Baking of rice cake. Baking of PVC granules as a slip-stop for a working gloves. Far infra-red sauna (sweating effect around 50/sup 0/C). Tokyo Gas Co., Ltd. and other companies introduced an IR spectroscopic radiometer of Minarad Systems of USA to establish a data exchange system in 1984. The spectroscopic radio-meter system consists of 3 components, i.e., a spectrophotometric radiometer, a black body furnace, and a computer for data processing. (14 figs, 5 tabs)

  4. Evaluating the use of renewable fuel sources to heat flue-cured tobacco barns

    OpenAIRE

    Brown, Robert T

    2018-01-01

    Evaluating the use of renewable fuel sources to heat flue-cured tobacco barns Robert Taylor Brown ABSTRACT The curing of flue-cured tobacco (Nicotiana tabacum L.) is an energy intensive process and represents a significant portion of the overall cost of production. Given the goal of the industry to reduce the environmental footprint of tobacco production and the energy demand of curing, attention has been directed to explore options for the use of renewable fuels for heating to...

  5. Plasma heating and hot ion sustaining in mirror based hybrids

    International Nuclear Information System (INIS)

    Moiseenko, V. E.; Ågren, O.

    2012-01-01

    Possibilities of plasma heating and sloshing ion sustaining in mirror based hybrids are briefly reviewed. Sloshing ions, i.e. energetic ions with a velocity distribution concentrated to a certain pitch-angle, play an important role in plasma confinement and generation of fusion neutrons in mirror machines. Neutral beam injection (NBI) is first discussed as a method to generate sloshing ions. Numerical results of NBI modeling for a stellarator-mirror hybrid are analyzed. The sloshing ions could alternatively be sustained by RF heating. Fast wave heating schemes, i.e. magnetic beach, minority and second harmonic heating, are addressed and their similarities and differences are described. Characteristic features of wave propagation in mirror hybrid devices including both fundamental harmonic minority and second harmonic heating are examined. Minority heating is efficient for a wide range of minority concentration and plasma densities; it allows one to place the antenna aside from the hot ion location. A simple-design strap antenna suitable for this has good performance. However, this scenario is appropriate only for light minority ions. The second harmonic heating can be applied for the heavy ion component. Arrangements are similar for minority and second harmonic heating. The efficiency of second harmonic heating is influenced by a weaker wave damping than for minority heating. Numerical calculations show that in a hybrid reactor scaled mirror machine the deuterium sloshing ions could be heated within the minority heating scheme, while the tritium ions could be sustained by second harmonic heating.

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

    NARCIS (Netherlands)

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

    2017-01-01

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

  7. Nanofluids and a method of making nanofluids for ground source heat pumps and other applications

    Science.gov (United States)

    Olson, John Melvin

    2013-11-12

    This invention covers nanofluids. Nanofluids are a combination of particles between 1 and 100 nanometers, a surfactant and the base fluid. The nanoparticles for this invention are either pyrogenic nanoparticles or carbon nanotubes. These nanofluids improve the heat transfer of the base fluids. The base fluid can be ethylene glycol, or propylene glycol, or an aliphatic-hydrocarbon based heat transfer fluid. This invention also includes a method of making nanofluids. No surfactant is used to suspend the pyrogenic nanoparticles in glycols.

  8. Failure analysis of radioisotopic heat source capsules tested under multi-axial conditions

    International Nuclear Information System (INIS)

    Zielinski, R.E.; Stacy, E.; Burgan, C.E.

    In order to qualify small radioisotopic heat sources for a 25-yr design life, multi-axial mechanical tests were performed on the structural components of the heat source. The results of these tests indicated that failure predominantly occurred in the middle of the weld ramp-down zone. Examination of the failure zone by standard metallographic techniques failed to indicate the true cause of failure. A modified technique utilizing chemical etching, scanning electron microscopy, and energy dispersive x-ray analysis was employed and dramatically indicated the true cause of failure, impurity concentration in the ramp-down zone. As a result of the initial investigation, weld parameters for the heat sources were altered. Example welds made with a pulse arc technique did not have this impurity buildup in the ramp-down zone

  9. Heat source component development program. Report for July--December 1978

    International Nuclear Information System (INIS)

    Foster, E.L. Jr.

    1979-01-01

    This is the seventh of a series of reports describing the results of several analytical and experimental programs being conducted at Battelle-Columbus Laboratories to develop components for advanced radioisotope heat source applications. The heat sources will for the most part be used in advanced static and dynamic power conversion systems. Battelle's support of LASL during the current reporting period has been to determine the operational and reentry response of selected heat source trial designs, and their thermal response to a space shuttle solid propellant fire environment. Thermal, ablation, and thermal stress analyses were conducted using two-dimensional modeling techniques previously employed for the analysis of the earlier trial design versions, and modified in part to improve the modeling accuracy. Further modifications were made to improve the modeling accuracy as described herein. Thermal, ablation, and thermal stress analyses were then conducted for the trial design selected by LASL/DOE for more detailed studies using three-dimensional modeling techniques

  10. Negative hydrogen ion beam extraction from an AC heated cathode driven Bernas-type ion source

    Energy Technology Data Exchange (ETDEWEB)

    Okano, Y.; Miyamoto, N.; Kasuya, T.; Wada, M.

    2015-04-08

    A plasma grid structure was installed to a Bernas-type ion source used for ion implantation equipment. A negative hydrogen (H{sup −}) ion beam was extracted by an AC driven ion source by adjusting the bias to the plasma grid. The extracted electron current was reduced by positively biasing the plasma grid, while an optimum plasma grid bias voltage for negative ion beam extraction was found to be positive 3 V with respect to the arc chamber. Source operations with AC cathode heating show extraction characteristics almost identical to that with DC cathode heating, except a minute increase in H{sup −} current at higher frequency of cathode heating current.

  11. Performance analysis and experimental study of heat-source tower solution regeneration

    International Nuclear Information System (INIS)

    Liang, Caihua; Wen, Xiantai; Liu, Chengxing; Zhang, Xiaosong

    2014-01-01

    Highlights: • Theoretical analysis is performed on the characteristics of heat-source tower. • Experimental study is performed on various rules of the solution regeneration rate. • The characteristics of solution regeneration vary widely with different demands. • Results are useful for optimizing the process of solution regeneration. - Abstract: By analyzing similarities and difference between the solution regeneration of a heat-source tower and desiccant solution regeneration, this paper points out that solution regeneration of a heat-source tower has the characteristics of small demands and that a regeneration rate is susceptible to outdoor ambient environments. A theoretical analysis is performed on the characteristics of a heat-source tower solution in different outdoor environments and different regeneration modes, and an experimental study is performed on variation rules of the solution regeneration rate of a cross-flow heat-source tower under different inlet parameters and operating parameters. The experimental results show that: in the operating regeneration mode, as the air volume was increased from 123 m 3 h −1 to 550 m 3 h −1 , the system heat transfer amount increased from 0.42 kW to 0.78 kW, and the regeneration rate increased from 0.03 g s −1 to 0.19 g s −1 . Increasing the solution flow may increase the system heat transfer amount; however, the regeneration rate decreased to a certain extent. In the regeneration mode when the system is idle, as the air volume was increased from 136 m 3 h −1 to 541 m 3 h −1 , the regeneration rate increased from 0.03 g s −1 to 0.1 g s −1 . The regeneration rate almost remained unchanged around 0.07 g s −1 as the solution flow is increased. In the regeneration mode with auxiliary heat when the system is idle, increasing the air volume and increasing the solution flow required more auxiliary heat, thereby improving the solution regeneration rate. As the auxiliary heat was increased from 0.33 k

  12. Energy consumption modeling of air source electric heat pump water heaters

    International Nuclear Information System (INIS)

    Bourke, Grant; Bansal, Pradeep

    2010-01-01

    Electric heat pump air source water heaters may provide an opportunity for significant improvements in residential water heater energy efficiency in countries with temperate climates. As the performance of these appliances can vary widely, it is important for consumers to be able to accurately assess product performance in their application to maximise energy savings and ensure uptake of this technology. For a given ambient temperature and humidity, the performance of an air source heat pump water heater is strongly correlated to the water temperature in or surrounding the condenser. It is therefore important that energy consumption models for these products duplicate the real-world water temperatures applied to the heat pump condenser. This paper examines a recently published joint Australian and New Zealand Standard, AS/NZS 4234: 2008; Heated water systems - Calculation of energy consumption. Using this standard a series TRNSYS models were run for several split type air source electric heat pump water heaters. An equivalent set of models was then run utilizing an alternative water use pattern. Unfavorable errors of up to 12% were shown to occur in modeling of heat pump water heater performance using the current standard compared to the alternative regime. The difference in performance of a model using varying water use regimes can be greater than the performance difference between models of product.

  13. Disruption simulation experiment using high-frequency rastering electron beam as the heat source

    International Nuclear Information System (INIS)

    Yamazaki, S.; Seki, M.

    1987-01-01

    The disruption is a serious event which possibly reduces the lifetime of plasm interactive components, so the effects of the resulting high heat flux on the wall materials must be clearly identified. The authors performed disruption simulation experiments to investigate melting, evaporation, and crack initiation behaviors using an electron beam facility as the heat source. The facility was improved with a high-frequency beam rastering system which provided spatially and temporally uniform heat flux on wider test surfaces. Along with the experiments, thermal and mechanical analyses were also performed. A two-dimensional disruption thermal analysis code (DREAM) was developed for the analyses

  14. Energy from Waste: Reuse of Compost Heat as a Source of Renewable Energy

    Directory of Open Access Journals (Sweden)

    G. Irvine

    2010-01-01

    Full Text Available An in-vessel tunnel composting facility in Scotland was used to investigate the potential for collection and reuse of compost heat as a source of renewable energy. The amount of energy offered by the compost was calculated and seasonal variations analysed. A heat exchanger was designed in order to collect and transfer the heat. This allowed heated water of 47.3oC to be obtained. The temperature could be further increased to above 60oC by passing it through multiple tunnels in series. Estimated costs for installing and running the system were calculated. In order to analyse these costs alternative solar thermal and ground source heat pump systems were also designed. The levels of supply and economic performance were then compared. A capital cost of £11,662 and operating cost of £1,039 per year were estimated, resulting in a cost of £0.50 per kWh for domestic water and £0.10 per kWh for spatial heat. Using the heat of the compost was found to provide the most reliable level of supply at a similar price to its rivals.

  15. Nuclear source of district heating in the north-east region of Russia

    International Nuclear Information System (INIS)

    Dolgov, V.V.

    1998-01-01

    The operation of the Bilibin Nuclear Co-generation Plant (BNCP) as a local district heating source is reviewed in this paper. Specific features of the BNCP power unit are given with special emphases on the components of the technological scheme, which are involved in the heat production and supply to the consumers. The scheme of steam extraction from the turbine, the flow diagram of steam in the turbine, as well as the three circuit heat removal system are described. The numerical characteristics of the nuclear heat supply system in various operating modes are presented. The real information characterizing current radiological conditions in the vicinity of the heat generation and distribution equipment is also presented in the paper. The BNCP technical and economical characteristics are compared with those of conventional energy sources. Both advantages and some problems revealed during the twenty-year experience of the BNCP nuclear heat utilization are generally assessed. Safety and reliability characteristics of the reactor and the heat supply system are also described. (author)

  16. Design and application for a high-temperature nuclear heat source

    International Nuclear Information System (INIS)

    Quade, R.N.

    1980-01-01

    Recent actions by OPEC have sharply increased interest in the United States in synfuels, with coal being the logical choice for the carbon source. Two coal liquefaction processes, direct and indirect, have been examined. Each can produce about 50% more output when coupled to an HTGR for process heat. The nuclear reactor designed for process heat has a power output of 842MW(t), a core outlet temperature of 950 0 C (1742 0 F), and an intermediate helium loop to separate the heat source from the process heat exchangers. Steam-methane reforming is the reference process. As part of the development of a nuclear process heat system, a computer code, Process Heat Reactor Evaluation and Design, is being developed. This code models both the reactor plant and a steam reforming plant. When complete, the program will have the capability to calculate an overall mass and heat balance, size the plant components, and estimate the plant cost for a wide variety of independent variables. (author)

  17. Analysis of the location for peak heating in CHP based combined district heating systems

    International Nuclear Information System (INIS)

    Wang, Haichao; Lahdelma, Risto; Wang, Xin; Jiao, Wenling; Zhu, Chuanzhi; Zou, Pinghua

    2015-01-01

    Combined heat and power (CHP) is the main technology for providing the base load of district heating in China. However, CHP is not efficient for providing the peak load; instead, a peak boiler with high efficiency could be used to compensate the peak load. This paper studies how the location of the peak boiler can affect the energy efficiency and economic performance of such CHP based combined district heating system. Firstly, the connection mode and the control strategy for different peak heating locations are analyzed. Then the effect of the peak boiler's location on the initial investment of the network and the cost for distributing heat is studied. The objective is to place the peak boiler in a location where the overall costs are the smallest. Following this rule, the results indicate that the peak boiler should be located at the CHP plant if that allows using cheaper ‘self-use electricity’ in CHP for distributing the heat. However, if the market electricity price is used everywhere, or if energy efficiency is more emphasized, the location of the peak boiler should be closer to the users with dense heat loads. - Highlights: • Location for peak heating in the CHP based combined DH system is studied. • Regulation or control strategies for combined DH are summarized. • The heat load duration curve for combined DH is demonstrated. • Network design for combined DH with peak boiler outside of the CHP is analyzed

  18. Experimental research on novel adsorption chiller driven by low grade heat source

    International Nuclear Information System (INIS)

    Wang, D.C.; Shi, Z.X.; Yang, Q.R.; Tian, X.L.; Zhang, J.C.; Wu, J.Y.

    2007-01-01

    A novel silica gel-water adsorption chiller is developed. This chiller consists of three vacuum chambers: two adsorption/desorption (or evaporation/condensation) vacuum chambers and one heat pipe working vacuum chamber. In this chiller, only one vacuum valve is installed between the two adsorption/desorption vacuum chambers to improve its performance when it is driven by a low temperature heat source. The operational reliability of the chiller is highly improved because of fewer moving parts. In this work, the performance of the chiller is experimentally tested under a low grade heat source, such as 55-67 o C. The test results show that the performance of this chiller is satisfying when it is driven by a low grade heat source, such as 65 o C, and the cooling capacity (or refrigeration capacity) will reach about 5 kW when the hot water temperature is 65 o C, the cooling water temperature is 30.5 o C and the chilled water inlet temperature is 15.1 o C. The test results confirm that this kind of adsorption chiller can be effectively driven by a low grade heat source

  19. Thermal modeling of multi-shape heating sources on n-layer electronic board

    Directory of Open Access Journals (Sweden)

    Monier-Vinard Eric

    2017-01-01

    Full Text Available The present work completes the toolbox of analytical solutions that deal with resolving steady-state temperatures of a multi-layered structure heated by one or many heat sources. The problematic of heating sources having non-rectangular shapes is addressed to enlarge the capability of analytical approaches. Moreover, various heating sources could be located on the external surfaces of the sandwiched layers as well as embedded at interface of its constitutive layers. To demonstrate its relevance, the updated analytical solution has been compared with numerical simulations on the case of a multi-layered electronic board submitted to a set of heating source configurations. The comparison shows a high agreement between analytical and numerical calculations to predict the centroid and average temperatures. The promoted analytical approach establishes a kit of practical expressions, easy to implement, which would be cumulated, using superposition principle, to help electronic designers to early detect component or board temperatures beyond manufacturer limit. The ability to eliminate bad concept candidates with a minimum of set-up, relevant assumptions and low computation time can be easily achieved.

  20. A thermoelectric-conversion power supply system using a strontium heat source of high-level radioactive nuclear waste

    International Nuclear Information System (INIS)

    Chikazawa, Yoshitaka

    2011-01-01

    A thermoelectric-conversion power supply system with radioactive strontium in high-level radioactive waste has been proposed. A combination of Alkali Metal Thermo-Electric Conversion (AMTEC) and a strontium fluoride heat source can provide a compact and long-lived power supply system. A heat source design with strontium fluoride pin bundles with Hastelloy cladding and intermediate copper has been proposed. This design has taken heat transportation into consideration, and, in this regard, the feasibility has been confirmed by a three-dimensional thermal analysis using Star-CD code. This power supply system with an electric output of 1 MW can be arranged in a space of 50 m 2 and approximately 1.1 m height and can be operated for 15 years without refueling. This compact and long-lived power supply is suitable for powering sources for remote places and middle-sized ships. From the viewpoint of geological disposal of high-level waste, the proposed power supply system provides a financial base for strontium-cesium partitioning. That is, a combination of minor-actinide recycling and strontium-cesium partitioning can eliminate a large part of decay heat in high-level waste and thus can save much space for geological disposal. (author)

  1. Suppression of cyclotron instability in Electron Cyclotron Resonance ion sources by two-frequency heating

    International Nuclear Information System (INIS)

    Skalyga, V.; Izotov, I.; Mansfeld, D.; Kalvas, T.; Koivisto, H.; Komppula, J.; Kronholm, R.; Laulainen, J.; Tarvainen, O.

    2015-01-01

    Multiple frequency heating is one of the most effective techniques to improve the performance of Electron Cyclotron Resonance (ECR) ion sources. The method increases the beam current and average charge state of the extracted ions and enhances the temporal stability of the ion beams. It is demonstrated in this paper that the stabilizing effect of two-frequency heating is connected with the suppression of electron cyclotron instability. Experimental data show that the interaction between the secondary microwave radiation and the hot electron component of ECR ion source plasmas plays a crucial role in mitigation of the instabilities

  2. Comparing costs of power and heat production by prospective and present sources

    International Nuclear Information System (INIS)

    Novak, S.

    1979-01-01

    Capital and running costs are compared of power and heat production from different sources. The lowest capital costs were found for coal-fired power plants followed by light water reactor power plants. The capital costs of other types of power plants, such as wind, geothermal, solar, thermonuclear power plants are significantly higher. The estimated specific cost for electric power production in 1985 for a nuclear power plant is lower than for a fossil-fuel power plant. It is estimated that in 1985 coal will be the cheapest heat source. (Ha)

  3. BRIGITTE, Dose Rate and Heat Source and Energy Flux for Self-Absorbing Rods

    International Nuclear Information System (INIS)

    Jegu, M.; Clement, M.

    1978-01-01

    1 - Nature of physical problem solved: Calculation of dose rate, heat sources or energy flux. The sources are self-absorbing radioactive rods. The shielding consists of blocks of which the cross section can be defined. 2 - Method of solution: Exponential attenuation and build-up factor between source points and detector points. Source integration with error estimate. Automatic or controlled build-up with monitor print-out. 3 - Restrictions on the complexity of the problem: Number of energy points, regions, detector points, abscissa points of the rod, vertical position of the rod, are all limited to ten. The maximum total number of vertical steps is 124

  4. Accelerator-based cold neutron sources and their cooling system

    International Nuclear Information System (INIS)

    Inoue, Kazuhiko; Yanai, Masayoshi; Ishikawa, Yoshikazu.

    1985-01-01

    We have developed and installed two accelerator-based cold neutron sources within a electron linac at Hokkaido University and a proton synchrotoron at National Laboratory for High Energy Physics. Solid methane at 20K was adopted as the cold moderator. The methane condensing heat exchangers attached directly to the moderator chambers were cooled by helium gas, which was kept cooled in refrigerators and circulated by ventilation fans. Two cold neutron sources have operated smoothly and safely for the past several years. In this paper we describe some of the results obtained in the preliminary experiments by using a modest capacity refrigerator, the design philosophy of the cooling system for the pulsed cold neutron sources, and outline of two facilities. (author)

  5. Sustainable renewable energy seawater desalination using combined-cycle solar and geothermal heat sources

    KAUST Repository

    Missimer, Thomas M.

    2013-01-01

    Key goals in the improvement of desalination technology are to reduce overall energy consumption, make the process "greener," and reduce the cost of the delivered water. Adsorption desalination (AD) is a promising new technology that has great potential to reduce the need for conventional power, to use solely renewable energy sources, and to reduce the overall cost of water treatment. This technology can desalt seawater or water of even higher salinity using waste heat, solar heat, or geothermal heat. An AD system can operate effectively at temperatures ranging from 55 to 80 °C with perhaps an optimal temperature of 80 °C. The generally low temperature requirement for the feedwater allows the system to operate quite efficiently using an alternative energy source, such as solar power. Solar power, particularly in warm dry regions, can generate a consistent water temperature of about 90 °C. Although this temperature is more than adequate to run the system, solar energy collection only can occur during daylight hours, thereby necessitating the use of heat storage during nighttime or very cloudy days. With increasing capacity, the need for extensive thermal storage may be problematic and could add substantial cost to the development of an AD system. However, in many parts of the world, there are subsurface geothermal energy sources that have not been extensively used. Combining a low to moderate geothermal energy recovery system to an AD system would provide a solution to the thermal storage issue. However, geothermal energy development from particularly Hot Dry Rock is limited by the magnitude of the heat flow required for the process and the thermal conductivity of the rock material forming the heat reservoir. Combining solar and geothermal energy using an alternating 12-h cycle would reduce the probability of depleting the heat source within the geothermal reservoir and provide the most effective use of renewable energy. © 2013 Desalination Publications.

  6. Effect of the inter-block spacing on the thermal performance of a PCM based heat sink

    Energy Technology Data Exchange (ETDEWEB)

    Faraji, M.; El Qarnia, H. [Cadi Ayyad Univ., Marrakech (Morocco). Faculte des sciences Semlalia, Dept. de physique, Laboratoire de mecanique des fluides et d' energetique; El Khadir, L. [Cadi Ayyad Univ., Marrakech (Morocco). Faculte des sciences Semlalia, Dept. de physique, Laboratoire d' tomatique de l' Environnement et Procedes de Transferts

    2010-07-01

    Advanced electronic devices require efficient thermal control systems. Heat transfer analysis of such systems is challenging because of constraints regarding space limitations, power consumption and noise level. This study considered the problem of melting and natural convection in a rectangular enclosure heated with 3 heat sources with a constant and uniform volumetric heat generation. The heat sources were protruding and mounted on a vertical conducting plate. Conjugate conduction in a plate and heat sources coupled with natural convection and melting process were examined in an effort to determine the effects of the inter-blocks spacing ratio on the thermal performance of the cooling PCM-heat sink. The percentage contribution of substrate heat conduction on the total removed heat from heat sources was also investigated. Correlations were derived for the non- dimensional secured working time and the corresponding melt fraction. In order to investigate the thermal behaviour of the proposed heat sink, a mathematical model was developed based on the mass, momentum and energy conservation equations. The results revealed that for lower inter-blocks spacing, the dimensionless secured working time needed by the chips to reach the critical temperature was maximized. The highest inter-blocks spacing ratio provoked a sudden rise in chip temperatures and thus reduced the dimensionless secured working time. It was concluded that this approach can be used in the design of PCM-based cooling systems. 9 refs., 2 tabs., 4 figs.

  7. Annual performance investigation and economic analysis of heating systems with a compression-assisted air source absorption heat pump

    International Nuclear Information System (INIS)

    Wu, Wei; Shi, Wenxing; Wang, Baolong; Li, Xianting

    2015-01-01

    Highlights: • Optimal compression ratio of CASAHP is obtained for the maximum energy saving rate. • Annual performance is improved by 10–20% compared to ASAHP without compression. • Energy saving rate is 17.7–29.2% and investment is reduced to 30–60% for CASAHP. • Both compression and partial-design enhance the economy with given energy saving. • Payback time is reduced from 12–32 to 3–6 years by compression and partial-design. - Abstract: The compression-assisted air source absorption heat pump (CASAHP) is a promising alternative heating system in severe operating conditions. In this research, parameter studies on the annual performance under various compression ratios (CRs) and source temperatures are performed to achieve the maximum energy saving rates (ESRs). Economic analyses of the CASAHP under different CRs and partial-design ratios are conducted to obtain an optimal design that considers both energy savings and economy improvements. The results show that the optimal CR becomes higher in colder regions and with lower heat source temperatures. For a source temperature of 130 °C, the optimal CR values in all of the cities are within 2.0. For source temperatures from 100 to 130 °C, the maximum ESR is in the range of 17.7–29.2% in the studied cities. The efficiency improvement rate (EIR) caused by compression in a severe source condition can reach 10.0–20.0%. From the viewpoint of economy, the relative investment of CASAHP is reduced to 30–60% with a CR of 2.0–3.0. With a 2–6% sacrifice in ESR, the payback period can be reduced from 12–32 to 5–9 years using compression. Partial-design of the CASAHP can further reduce the payback period to 3–6 years with a partial-design ratio of 50% and a CR of 2.8. Additionally, CRs and partial-design ratios are designed comprehensively by seeking the maximum ESR for a given acceptable payback period

  8. Power performance of the general-purpose heat source radioisotope thermoelectric generator

    International Nuclear Information System (INIS)

    Bennett, G.L.; Lombardo, J.J.; Rock, B.J.

    1986-01-01

    The General-Purpose Heat Source Radioisotope Thermoelectric Generator (GRHS-RTG) has been developed under the sponsorship of the Department of Energy (DOE) to provide electrical power for the National Aeronautics and Space Administration (NASA) Galileo mission to Jupiter and the joint NASA/European Space Agency (ESA) Ulysses mission to study the polar regions of the sun. A total of five nuclear-heated generators and one electrically heated generator have been built and tested, proving out the design concept and meeting the specification requirements. The GPHS-RTG design is built upon the successful-technology used in the RTGs flown on the two NASA Voyager spacecraft and two US Air Force communications satellites. THe GPHS-RTG converts about 4400 W(t) from the nuclear heat source into at least 285 W(e) at beginning of mission (BOM). The GPHS-RTG consists of two major components: the General-Purpose Heat Source (GPHS) and the Converter. A conceptual drawing of the GPHs-RTG is presented and its design and performance are described

  9. A small-plane heat source method for measuring the thermal conductivities of anisotropic materials

    Science.gov (United States)

    Cheng, Liang; Yue, Kai; Wang, Jun; Zhang, Xinxin

    2017-07-01

    A new small-plane heat source method was proposed in this study to simultaneously measure the in-plane and cross-plane thermal conductivities of anisotropic insulating materials. In this method the size of the heat source element is smaller than the sample size and the boundary condition is thermal insulation due to no heat flux at the edge of the sample during the experiment. A three-dimensional model in a rectangular coordinate system was established to exactly describe the heat transfer process of the measurement system. Using the Laplace transform, variable separation, and Laplace inverse transform methods, the analytical solution of the temperature rise of the sample was derived. The temperature rises calculated by the analytical solution agree well with the results of numerical calculation. The result of the sensitivity analysis shows that the sensitivity coefficients of the estimated thermal conductivities are high and uncorrelated to each other. At room temperature and in a high-temperature environment, experimental measurements of anisotropic silica aerogel were carried out using the traditional one-dimensional plane heat source method and the proposed method, respectively. The results demonstrate that the measurement method developed in this study is effective and feasible for simultaneously obtaining the in-plane and cross-plane thermal conductivities of the anisotropic materials.

  10. First in situ operation performance test of ground source heat pump in Tunisia

    International Nuclear Information System (INIS)

    Naili, Nabiha; Attar, Issam; Hazami, Majdi; Farhat, Abdelhamid

    2013-01-01

    Highlights: • Evaluate the geothermal energy in Tunisia. • Study of the performance of GSHP system for cooling space. • GSHP is a promising alternative for building cooling in Tunisia. - Abstract: The main purpose of this paper is to study the energetic potential of the deployment in Tunisia of the Ground Source Heat Pump (GSHP) system for cooling mode application. Therefore, a pilot GSHP system using horizontal Ground Heat Exchanger (GHE) was installed and experimented in the Research and Technology Center of Energy (CRTEn), Borj Cédria. The experiment is conducted in a test room with a floor area of about 12 m 2 . In the floor of the tested room is integrated a polyethylene exchanger (PEX) used as a radiant floor cooling (RFC) system. The experimental setup mainly includes the ground temperature, the temperature and flow rate of water circulating in the heat pump and the GHE, as well as the power consumption of the heat pump and circulating pumps. These experimental data are essentially used to evaluate the coefficient of performance of the heat pump (COP hp ) and the overall system (COP sys ) for continuous operation mode. The COP hp and the COP sys were found to be 4.25 and 2.88, respectively. These results reveal that the use of the ground source heat pump is very appropriate for Tunisian building cooling

  11. Induction heating of a spherical aluminum moderator vessel for the Advanced Neutron Source (ANS)

    International Nuclear Information System (INIS)

    Yousuf, A.

    1994-01-01

    This task was to identify and design a heating system to apply 15 kW of heat to a cold source vessel to simulate the Advanced Neutron Source reactor. This research project aims at the analysis of the induction heating of a spherical aluminum moderator vessel. Computer modeling is presented for the design and analysis of the induction heating system. The objective is to apply 15 kW of heat as uniformly as possible to the outer wall of a 410 mm diameter sphere of thickness 1.5 mm. The report also aims at the analysis of a system model which is simulated using the Eddycuff electromagnetic software. The computer model is built with the finite element analysis software Patran. The induction heating system analysis shows that the predicted performance is in close agreement with the computer simulated data. Hardware constraints such as power supplies and matching load are also analyzed in terms of performance and cost. Physical modeling is also suggested, in which the coil and the workpiece are scaled down

  12. Heat and mass release for some transient fuel source fires: A test report

    International Nuclear Information System (INIS)

    Nowlen, S.P.

    1986-10-01

    Nine fire tests using five different trash fuel source packages were conducted by Sandia National Laboratories. This report presents the findings of these tests. Data reported includes heat and mass release rates, total heat and mass release, plume temperatures, and average fuel heat of combustion. These tests were conducted as a part of the US Nuclear Regulatory Commission sponsored fire safety research program. Data from these tests were intended for use in nuclear power plant probabilistic risk assessment fire analyses. The results were also used as input to a fire test program at Sandia investigating the vulnerability of electrical control cabinets to fire. The fuel packages tested were chosen to be representative of small to moderately sized transient trash fuel sources of the type that would be found in a nuclear power plant. The highest fire intensity encountered during these tests was 145 kW. Plume temperatures did not exceed 820 0 C

  13. Study on a groundwater source heat pump cooling system in solar greenhouse

    Energy Technology Data Exchange (ETDEWEB)

    Chai, Lilong; Ma, Chengwei [China Agricultural Univ., Beijing (China). Coll. of Water Conservancy and Civil Engineering. Dept. of Agricultural Structure and Bio-environmental Engineering], E-mail: macwbs@cau.edu.cn

    2008-07-01

    This study aims at exploiting the potential of ground source heat pump (GSHP) technology in cooling agricultural greenhouse, and advocating the use of renewable and clean energy in agriculture. GSHP has the multi-function of heating, cooling and dehumidifying, which is one of the fastest growing technologies of renewable energy air conditioning in recent years. The authors carried out experiment on the ground source heat pump system in cooling greenhouse in Beijing region during the summertime of 2007, and conducted analysis on the energy efficiency of the system by using coefficient of performance (COP). According to the data collected during Aug.13-18th, 2007, the coefficient of performance of GSHP system (COP{sub sys}) has reached 3.15 on average during the test. (author)

  14. General-purpose heat source safety verification test series: SVT-11 through SVT-13

    International Nuclear Information System (INIS)

    George, T.G.; Pavone, D.

    1986-05-01

    The General-Purpose Heat Source (GPHS) is a modular component of the radioisotope thermoelectric generator that will provide power for the Galileo and Ulysses (formerly ISPM) space missions. The GPHS provides power by transmitting the heat of 238 Pu α-decay to an array of thermoelectric elements. Because the possibility of an orbital abort always exists, the heat source was designed and constructed to minimize plutonia release in any accident environment. The Safety Verification Test (SVT) series was formulated to evaluate the effectiveness of GPHS plutonia containment after atmospheric reentry and Earth impact. The first two reports (covering SVT-1 through SVT-10) described the results of flat, side-on, and angular module impacts against steel targets at 54 m/s. This report describes flat-on module impacts against concrete and granite targets, at velocities equivalent to or higher than previous SVTs

  15. Integration of available regenerative energy sources in community networks for both electricity and heating

    Energy Technology Data Exchange (ETDEWEB)

    Alcalde Melo, Henrique

    2013-03-06

    In the last years, energy prices for German households have been increasing constantly. Some reasons for that include: the dependency of Germany on external fossil fuels to supply its energy demand, the decision to invest in renewable energy generation and to shut down all its nuclear power plants. Nowadays households are already able to generate energy on-site, however the generation potential depends on climatic conditions as well as the specific location and the type of the building. The aim of this work is to evaluate whether a community of new efficient single-family houses can generate enough energy on-site to supply its electricity and heating demand over the year based on renewable energy sources and with the support of energy storage systems, including electric vehicles. The theoretical community is situated in the city of Cottbus, Germany. For this community, an electricity load profile was designed based on the use of common devices and separated in controllable and uncontrollable loads. Electricity is generated on-site through photovoltaic panels and small wind turbines, and the electricity generation potential is evaluated based on the community's available space, which is rather limited, and the actual regulations in the State of Brandenburg. A comparison of the available technologies to supply the heating demand as well as to store energy in the household sector is presented and discussed. It is assumed that each household has an electric vehicle that can be charged and also discharged in the community as an extra energy storage system. A software simulation system was designed with which an energy balance analysis is carried out based on hourly values of supply and demand. Under the assumptions taken for this study, the results of the simulation show that the community is able to generate more energy than consumed throughout a year, however in a few occasions there is not enough energy available to supply the community's energy demand

  16. Integration of available regenerative energy sources in community networks for both electricity and heating

    Energy Technology Data Exchange (ETDEWEB)

    Alcalde Melo, Henrique

    2013-03-06

    In the last years, energy prices for German households have been increasing constantly. Some reasons for that include: the dependency of Germany on external fossil fuels to supply its energy demand, the decision to invest in renewable energy generation and to shut down all its nuclear power plants. Nowadays households are already able to generate energy on-site, however the generation potential depends on climatic conditions as well as the specific location and the type of the building. The aim of this work is to evaluate whether a community of new efficient single-family houses can generate enough energy on-site to supply its electricity and heating demand over the year based on renewable energy sources and with the support of energy storage systems, including electric vehicles. The theoretical community is situated in the city of Cottbus, Germany. For this community, an electricity load profile was designed based on the use of common devices and separated in controllable and uncontrollable loads. Electricity is generated on-site through photovoltaic panels and small wind turbines, and the electricity generation potential is evaluated based on the community's available space, which is rather limited, and the actual regulations in the State of Brandenburg. A comparison of the available technologies to supply the heating demand as well as to store energy in the household sector is presented and discussed. It is assumed that each household has an electric vehicle that can be charged and also discharged in the community as an extra energy storage system. A software simulation system was designed with which an energy balance analysis is carried out based on hourly values of supply and demand. Under the assumptions taken for this study, the results of the simulation show that the community is able to generate more energy than consumed throughout a year, however in a few occasions there is not enough energy available to supply the community's energy demand. Water can be

  17. Exposure calculations for the FRG isotopic heat source project environmental assessment

    International Nuclear Information System (INIS)

    Metcalf, I.L.

    1997-01-01

    The report documents the maximum exposure for transfer of the Federal Republic of Germany (FRG) Isotopic Heat Sources from the 324 Building and placed in interim storage at the Central Waste Complex (CWC). These results are to be reported in the Environmental Assessment DOE-EA- 1 21 1

  18. Dynamic energy converters using an outer heat source for ground uses. Bibliographic study

    International Nuclear Information System (INIS)

    Bousquet, Jean-Louis du

    1969-01-01

    This short bibliographical review presents the main dynamical conversion systems operating with an outer heat source, used for power ranges of a few hundreds Watts to a few hundreds kilowatts and dedicated to ground uses. The study has three parts: recollection of thermodynamic cycles; review of some present or projected realizations; a critical study for selecting converter components (turbine, reciprocating engine, thermodynamical fluid) [fr

  19. Evaluation and characterization of General Purpose Heat Source girth welds for the Cassini mission

    International Nuclear Information System (INIS)

    Lynch, C.M.; Moniz, P.F.; Reimus, M.A.H.

    1998-01-01

    General Purpose Heat Sources (GPHSs) are components of Radioisotopic thermoelectric Generators (RTGs) which provide electric power for deep space missions. Each GPHS consists of a 238 Pu oxide ceramic pellet encapsulated in a welded iridium alloy shell which forms a protective barrier against the release of plutonia in the unlikely event of a launch-pad failure or reentry incident. GPHS fueled clad girth weld flaw detection was paramount to ensuring this safety function, and was accomplished using both destructive and non-destructive evaluation techniques. The first girth weld produced from each welding campaign was metallographically examined for flaws such as incomplete weld penetration, cracks, or porosity which would render a GPHS unacceptable for flight applications. After an acceptable example weld was produced, the subsequently welded heat sources were evaluated non-destructively for flaws using ultrasonic immersion testing. Selected heat sources which failed ultrasonic testing would be radiographed, and/or, destructively evaluated to further characterize and document anomalous indications. Metallography was also performed on impacted heat sources to determine the condition of the welds

  20. Specific power reduction of an ion source due to heating and cathode sputtering of electrodes

    International Nuclear Information System (INIS)

    Hamilton, G.U.; Semashko, N.N.

    The potentialities and limitations of the water-cooled ion-optical system of the ion source designed for continuous operation of the high-power neutral beam injector are determined. The following problems are analyzed: thermal expansion and deformation of electrodes, electrode sputtering as a result of bombardment, and heat transfer to turbulent flow of water

  1. On the mineralization model of 'three sources--heat, water and uranium'

    International Nuclear Information System (INIS)

    Li Xueli

    1992-01-01

    In response to the relations between geological and geothermal settings, geothermal water and uranium mineralizations in the Southeastern China, the model of uranium mineralization in discharge area (depressurization area) of fossil geothermal systems in Mesozoic-Cenozoic Volcanic-magmatic active areas has been put forward and expounded in the view of mineral-formation by the 'three sources'-heat, water and uranium

  2. Savannah River Laboratory isotopic power and heat sources. Monthly report, June 1966

    International Nuclear Information System (INIS)

    1966-06-01

    Progress in research and development is described for the following: preparation of Tm 2 O 3 ; properties of thulium-171; reduction of Pu-236 in Pu-238; 238 Pu oxide with low neutron emission; and encapsulation of cobalt-60 heat sources

  3. Unveiling the sources of disk heating in spiral galaxies with the CALIFA survey

    NARCIS (Netherlands)

    Pinna, F.; Falcón-Barroso, J.; Martig, M.; van de Ven, G.; Lyubenova, M.; Leaman, R.

    The stellar velocity ellipsoid (SVE) quantifies the amount of velocity dispersion in the vertical, radial and azimuthal directions. Since different disk heating mechanisms (e.g. spiral arms, giant molecular clouds, mergers, etc) affect these components differently, the SVE can constrain the sources

  4. Alternative energy sources for the heating and cooling of a building

    CSIR Research Space (South Africa)

    Strydom, JFS

    1979-11-27

    Full Text Available The objective of two of the studies was to choose the most economical source of heating energy, taking cognizance of the building owner’s particular circumstances; in both cases a suitable alternative to light petroleum oil, which had been used...

  5. FRG sealed isotopic heat sources project (C-229) project management plan

    International Nuclear Information System (INIS)

    Metcalf, I.L.

    1997-01-01

    This Project Management Plan defines the cost, scope, schedule, organizational responsibilities, and work breakdown structure for the removal of the Federal Republic of Germany (FRG) Sealed Isotopic Heat Sources from the 324 Building and placed in interim storage at the Central Waste Complex (CWC)

  6. Boundary Layer Fluid Flow in a Channel with Heat Source, Soret ...

    African Journals Online (AJOL)

    The boundary layer fluid flow in a channel with heat source, soret effects and slip condition was studied. The governing equations were solved using perturbation technique. The effects of different parameters such Prandtl number Pr , Hartmann number M, Schmidt number Sc, suction parameter ƒÜ , soret number Sr and the ...

  7. A heat source probe for measuring thermal conductivity in waste rock dumps

    International Nuclear Information System (INIS)

    Blackford, M.G.; Harries, J.R.

    1985-10-01

    The development and use of a heat source probe to measure the thermal conductivity of the material in a waste rock dump is described. The probe releases heat at a constant rate into the surrounding material and the resulting temperature rise is inversely related to the thermal conductivity. The probe was designed for use in holes in the dump which are lined with 50 mm i.d. polyethylene liners. The poor thermal contact between the probe and the liner and the unknown conductivity of the backfill material around the liner necessitated long heating and cooling times (>10 hours) to ensure that the thermal conductivity of the dump material was being measured. Temperature data acquired in the field were analysed by comparing them with temperatures calculated using a two-dimensional cylindrical model of the probe and surrounding material, and the heat transfer code HEATRAN

  8. Nanomaterial-based x-ray sources

    Science.gov (United States)

    Cole, Matthew T.; Parmee, R. J.; Milne, William I.

    2016-02-01

    Following the recent global excitement and investment in the emerging, and rapidly growing, classes of one and two-dimensional nanomaterials, we here present a perspective on one of the viable applications of such materials: field electron emission based x-ray sources. These devices, which have a notable history in medicine, security, industry and research, to date have almost exclusively incorporated thermionic electron sources. Since the middle of the last century, field emission based cathodes were demonstrated, but it is only recently that they have become practicable. We outline some of the technological achievements of the past two decades, and describe a number of the seminal contributions. We explore the foremost market hurdles hindering their roll-out and broader industrial adoption and summarise the recent progress in miniaturised, pulsed and multi-source devices.

  9. Accelerator-based pulsed cold neutron source

    International Nuclear Information System (INIS)

    Inoue, Kazuhiko; Iwasa, Hirokatsu; Kiyanagi, Yoshiaki

    1979-01-01

    An accelerator-based pulsed cold neutron source was constructed. The accelerator is a 35 MeV electron linear accelerator with 1 kW average beam power. The cold neutron beam intensity at a specimen is equivalent to that of a research reactor of 10 14 n/cm 2 .s thermal flux in the case of the quasi-elastic neutron scattering measurements. In spite of some limitations to the universal uses, it has been demonstrated by this facility that the modest capacity accelerator-based pulsed cold neutron source is a highly efficient cold neutron source with low capital investment. Design philosophy, construction details, performance and some operational experiences are described. (author)

  10. Optimization and Thermoeconomics Research of a Large Reclaimed Water Source Heat Pump System

    Directory of Open Access Journals (Sweden)

    Zi-ping Zhang

    2013-01-01

    Full Text Available This work describes a large reclaimed water source heat pump system (RWSHPS and elaborates on the composition of the system and its design principles. According to the characteristics of the reclaimed water and taking into account the initial investment, the project is divided into two stages: the first stage adopts distributed heat pump heating system and the second adopts the combination of centralized and decentralized systems. We analyze the heating capacity of the RWSHPS, when the phase II project is completed, the system can provide hydronic heating water with the supply and return water temperature of 55°C/15°C and meet the hydronic heating demand of 8 million square meters of residential buildings. We make a thermal economics analysis by using Thermal Economics theory on RWSHPS and gas boiler system, it is known that the RWSHPS has more advantages, compared with the gas boiler heating system; both its thermal efficiency and economic efficiency are relatively high. It provides a reference for future applications of the RWSHPS.

  11. Sensitivity analysis on the performances of a closed-loop Ground Source Heat Pump

    Science.gov (United States)

    Casasso, Alessandro; Sethi, Rajandrea

    2014-05-01

    Ground Source Heat Pumps (GSHP) permit to achieve a significant reduction of greenhouse gas emissions, and the margins for economic saving of this technology are strongly correlated to the long-term sustainability of the exploitation of the heat stored in the soil. The operation of a GSHP over its lifetime should be therefore modelled considering realistic conditions, and a thorough characterization of the physical properties of the soil is essential to avoid large errors of prediction. In this work, a BHE modelling procedure with the finite-element code FEFLOW is presented. Starting from the governing equations of the heat transport in the soil around a GSHP and inside the BHE, the most important parameters are individuated and the adopted program settings are explained. A sensitivity analysis is then carried on both the design parameters of the heat exchanger, in order to understand the margins of improvement of a careful design and installation, and the physical properties of the soil, with the aim of quantifying the uncertainty induced by their variability. The relative importance of each parameter is therefore assessed by comparing the statistical distributions of the fluid temperatures and estimating the energy consumption of the heat pump, and practical conclusions are from these results about the site characterization, the design and the installation of a BHE. References Casasso A., Sethi R., 2014 Efficiency of closed loop geothermal heat pumps: A sensitivity analysis, Renewable Energy 62 (2014), pp. 737-746 Chiasson A.C., Rees S.J., Spitler J.D., 2000, A preliminary assessment of the effects of groundwater flow on closed-loop ground-source heat pump systems, ASHRAE Transactions 106 (2000), pp. 380-393 Delaleux F., Py X., Olives R., Dominguez A., 2012, Enhancement of geothermal borehole heat exchangers performances by improvement of bentonite grouts conductivity, Applied Thermal Engineering 33-34, pp. 92-99 Diao N., Li Q., Fang Z., 2004, Heat transfer in

  12. Renewable-based low-temperature district heating for existing buildings in various stages of refurbishment

    DEFF Research Database (Denmark)

    Brand, Marek; Svendsen, Svend

    2013-01-01

    Denmark is aiming for a fossil-free heating sector for buildings by 2035. Judging by the national heating plan, this will be achieved mainly by a further spread of DH (district heating) based on the renewable heat sources. To make the most cost-effective use of these sources, the DH supply...... and, for 98% of the year, to below 60 °C. However for the temperatures below 60 °C a low-temperature DH substation is required for DHW (domestic hot water) heating. This research shows that renewable sources of heat can be integrated into the DH system without problems and contribute to the fossil...... temperature should be as low as possible. We used IDA–ICE software to simulate a typical Danish single-family house from the 1970s connected to DH at three different stages of envelope and space heating system refurbishment. We wanted to investigate how low the DH supply temperature can be without reducing...

  13. Identifying (subsurface) anthropogenic heat sources that influence temperature in the drinking water distribution system

    Science.gov (United States)

    Agudelo-Vera, Claudia M.; Blokker, Mirjam; de Kater, Henk; Lafort, Rob

    2017-09-01

    The water temperature in the drinking water distribution system and at customers' taps approaches the surrounding soil temperature at a depth of 1 m. Water temperature is an important determinant of water quality. In the Netherlands drinking water is distributed without additional residual disinfectant and the temperature of drinking water at customers' taps is not allowed to exceed 25 °C. In recent decades, the urban (sub)surface has been getting more occupied by various types of infrastructures, and some of these can be heat sources. Only recently have the anthropogenic sources and their influence on the underground been studied on coarse spatial scales. Little is known about the urban shallow underground heat profile on small spatial scales, of the order of 10 m × 10 m. Routine water quality samples at the tap in urban areas have shown up locations - so-called hotspots - in the city, with relatively high soil temperatures - up to 7 °C warmer - compared to the soil temperatures in the surrounding rural areas. Yet the sources and the locations of these hotspots have not been identified. It is expected that with climate change during a warm summer the soil temperature in the hotspots can be above 25 °C. The objective of this paper is to find a method to identify heat sources and urban characteristics that locally influence the soil temperature. The proposed method combines mapping of urban anthropogenic heat sources, retrospective modelling of the soil temperature, analysis of water temperature measurements at the tap, and extensive soil temperature measurements. This approach provided insight into the typical range of the variation of the urban soil temperature, and it is a first step to identifying areas with potential underground heat stress towards thermal underground management in cities.

  14. Shallow Groundwater Temperatures and the Urban Heat Island Effect: the First U.K City-wide Geothermal Map to Support Development of Ground Source Heating Systems Strategy

    Science.gov (United States)

    Patton, Ashley M.; Farr, Gareth J.; Boon, David P.; James, David R.; Williams, Bernard; Newell, Andrew J.

    2015-04-01

    The first UK city-wide heat map is described based on measurements of groundwater from a shallow superficial aquifer in the coastal city of Cardiff, Wales, UK. The UK Government has a target of reducing greenhouse gas emissions by 80% by 2050 (Climate Change Act 2008) and low carbon technologies are key to achieving this. To support the use of ground source heating we characterised the shallow heat potential of an urban aquifer to produce a baseline dataset which is intended to be used as a tool to inform developers and to underpin planning and regulation. We exploited an existing network of 168 groundwater monitoring boreholes across the city, recording the water temperature in each borehole at 1m depth intervals up to a depth of 20m. We recorded groundwater temperatures during the coldest part of 2014, and repeat profiling of the boreholes in different seasons has added a fourth dimension to our results and allowed us to characterise the maximum depth of seasonal temperature fluctuation. The temperature profiles were used to create a 3D model of heat potential within the aquifer using GOCAD® and the average borehole temperatures were contoured using Surfer® 10 to generate a 2D thermal resource map to support future assessment of urban Ground Source Heat Pumps prospectively. The average groundwater temperature in Cardiff was found to be above the average for England and Wales (11.3°C) with 90% of boreholes in excess of this figure by up to 4°C. The subsurface temperature profiles were also found to be higher than forecast by the predicted geothermal gradient for the area. Potential sources for heat include: conduction from buildings, basements and sub-surface infrastructure; insulation effects of the urban area and of the geology, and convection from leaking sewers. Other factors include recharge inhibition by drains, localised confinement and rock-water interaction in specific geology. It is likely to be a combination of multiple factors which we are hoping

  15. A general framework to select working fluid and configuration of ORCs for low-to-medium temperature heat sources

    International Nuclear Information System (INIS)

    Vivian, Jacopo; Manente, Giovanni; Lazzaretto, Andrea

    2015-01-01

    Highlights: • General guidelines are proposed to select ORC working fluid and cycle layout. • Distance between critical and heat source temperature for optimal fluid selection. • Separate contributions of cycle efficiency and heat recovery factor. - Abstract: The selection of the most suitable working fluid and cycle configuration for a given heat source is a fundamental step in the search for the optimum design of Organic Rankine Cycles. In this phase cycle efficiency and heat source recovery factor lead to opposite design choices in the achievement of maximum system efficiency and, in turn, maximum power output. In this work, both separate and combined effects of these two performance factors are considered to supply a thorough understanding of the compromise resulting in maximum performance. This goal is pursued by carrying out design optimizations of four different ORC configurations operating with twenty-seven working fluids and recovering heat from sensible heat sources in the temperature range 120–180 °C. Optimum working fluids and thermodynamic parameters are those which simultaneously allow high cycle efficiency and high heat recovery from the heat source to be obtained. General guidelines are suggested to reach this target for any system configuration. The distance between fluid critical temperature and inlet temperature of the heat source is found to play a key role in predicting the optimum performance of all system configurations regardless of the inlet temperature of the heat source

  16. Design and instrumentation of an automotive heat pump system using ambient air, engine coolant and exhaust gas as a heat source

    International Nuclear Information System (INIS)

    Hosoz, M.; Direk, M.; Yigit, K.S.; Canakci, M.; Alptekin, E.; Turkcan, A.

    2009-01-01

    Because the amount of waste heat used for comfort heating of the passenger compartment in motor vehicles decreases continuously as a result of the increasing engine efficiencies originating from recent developments in internal combustion engine technology, it is estimated that heat requirement of the passenger compartment in vehicles using future generation diesel engines will not be met by the waste heat taken from the engine coolant. The automotive heat pump (AHP) system can heat the passenger compartment individually, or it can support the present heating system of the vehicle. The AHP system can also be employed in electric vehicles, which do not have waste heat, as well as vehicles driven by a fuel cell. The authors of this paper observed that such an AHP system using ambient air as a heat source could not meet the heat requirement of the compartment when ambient temperature was extremely low. The reason is the decrease in the amount of heat taken from the ambient air as a result of low evaporating temperatures. Furthermore, the moisture condensed from air freezed on the evaporator surface, thus blocking the air flow through it. This problem can be solved by using the heat of engine coolant or exhaust gases. In this case, the AHP system can have a higher heating capacity and reuse waste heat. (author)

  17. 基于太阳能光伏光热组件的双热源热泵机组的实验研究%Experimental Research of Dual-source Heat Pump Unit Based on Solar Photovoltaic and Photothermal Component

    Institute of Scientific and Technical Information of China (English)

    陈剑波; 孙坤; 聂琳杰; 陈雷田

    2015-01-01

    本文基于太阳能光伏光热一体化系统,设计出应用太阳能光伏光热及空气源的双热源热泵机组。使热泵与太阳能光伏光热组件结合组成太阳能热泵系统,利用太阳能光伏光热组件( PV/T)内循环水及空气源的能量制取生活热水,同时降低太阳能光伏光热组件内循环水的温度,从而降低太阳能光伏板的温度。通过实验测得机组在水冷蒸发侧进水温度20℃,热水出水温度50℃的额定工况下,制冷量为2.855 kW,制热量为3.594 kW,COP为3.6。机组在水-水工况及水-风工况下运行的节能性研究结果表明,相对于单一空气源热泵,双热源热泵机组在满足家庭用生活热水需求的前提下,利用热泵技术回收太阳能光伏光热的热量制取生活热水节能性显著。%Based on the solar photovoltaic-thermal integrated system, we designed a dual-source, i. e. , solar photovoltaic-thermal and air source, heat pump unit. The unit becomes solar assisted heat pump system when combined with solar photovoltaic thermal unit, which produces domestic hot water by air source and circulating water in the solar photovoltaic solar-thermal components ( PV/T) and reduces circulating water temperature and solar photovoltaic panel temperature. We drew the conclusion by experiment that when the inflow water temperature is 20 ℃ on the evaporation side and the outflow hot water temperature is 50 ℃ under the rated conditions, the unit capacity is 2. 855 kW for refrigeration and 3. 594 kW for heating, and the COP is 3. 6. When the unit operates in the water-water condition and wa-ter-air condition, the experiment result shows the dual-source heat pump unit has remarkable energy-saving compared with single air source heat pump when the photovoltaic-thermal solar heat is used for domestic hot water.

  18. An assessment of dynamic energy conversion systems for terrestrial radioisotope heat sources

    International Nuclear Information System (INIS)

    Thayer, G.R.

    1985-01-01

    The use of dynamic conversion systems to convert to electricity the heat generated in a 7500 W(t) 90 Sr radioisotopic heat source is examined. Brayton Cycle, three Organic Rankine systems (Barber-Nichols/ORMAT, Sundstrand, and TRW concepts), Organic Rankine plus thermoelectrics, and Stirling Engine systems were studied. The systems were ranked for a North Warning System mission using a Los Alamos Multi-Attribute Decision Theory code. Three different heat source designs were used: Case I with a beginning of life (BOL) source temperature of 640 0 C, Case II with a BOL source temperature of 745 0 C, and Case III with a BOL source temperature of 945 0 C. The Stirling Engine system was the top-ranked system for Cases I and II, closely followed by the ORC systems in Case I and ORC and thermoelectrics in Case II. The Brayton-Cycle system was top-ranked for Case III, with the Stirling Engine system a close second

  19. Quantification of exploitable shallow geothermal energy by using Borehole Heat Exchanger coupled Ground Source Heat Pump systems

    International Nuclear Information System (INIS)

    Hein, Philipp; Zhu, Ke; Bucher, Anke; Kolditz, Olaf; Pang, Zhonghe; Shao, Haibing

    2016-01-01

    Highlights: • The amount of technically exploitable shallow geothermal energy was quantified. • Therefore, a comprehensive numerical borehole heat exchanger model was employed. • The concept of equivalent temperature drop is introduced. • For one BHE, an equivalent temperature drop of 1.8–2.8 °C over 30 years is realistic • The average extractable energy amount evaluates to be 3.5–5.4 kW h m"−"2 a"−"1. - Abstract: In previous studies, the amount of exploitable shallow geothermal energy was estimated by assuming a uniform temperature drop of 2–6 °C in the aquifer. In this work, a more comprehensive numerical model has been employed to evaluate the available amount of shallow geothermal energy by using Borehole Heat Exchanger coupled Ground Source Heat Pump systems. Numerical experiments have been performed by simulating the long-term evolution of the subsurface temperature field, which is subject to the operation of borehole heat exchangers and varying parameters like subsurface thermal conductivity and groundwater flow velocity. The concept of equivalent temperature drop is proposed as an auxiliary quantity for the subsurface. With the help of this parameter, a procedure has been established to quantify the amount of shallow geothermal potential. Following this approach, a realistic equivalent temperature reduction is found to be from −1.8 to −4.4 °C in the subsurface over a period of 30 years. This can be translated to an annual extractable geothermal energy value in a unit surface area, and it ranges from 3.5 to 8.6 kW h m"−"2 a"−"1. The exact value is site specific and heavily depends on the soil thermal conductivity, groundwater velocity, and borehole arrangement.

  20. Heat transfer optimization of SCO2 porous flow based on Brinkman model

    Directory of Open Access Journals (Sweden)

    Lin David T.W.

    2016-01-01

    Full Text Available The purpose of this study is to obtain the optimal operating condition in order to find the maximum supercritical CO2 heat extraction in the enhanced geothermal system (EGS. In this study, the heat transfer model conjugated with the Brinkman model is used to evaluate the thermal behavior in the reservoir of the EGS. This numerical model is validated by experiment. Optimization is processed based on the Nelder-Mead approach. The optimal operating conditions are proposed with different pressure, porosity. This study will build the optimal platform of heat source of geothermal power plant.

  1. Lithuanian heat sector: Today based on imported fossil fuel, tomorrow - On local biofuel and wastes

    Energy Technology Data Exchange (ETDEWEB)

    Janukonis, Andrius

    2010-09-15

    District heating sector is one of the most important energy sectors in Lithuania, operation of which is closely related to other energy sectors such as electricity, natural gas, oil products, renewable energy sources. Main priorities of Lithuanian energy policy based on the experience of the neighboring countries and directives of the European Union's environmental protection, security and reliability of energy supply and availability of district heating services to all users. It is necessary to use widely the biofuel in the DHS sector for the heat production, unused amounts of which are very big.

  2. Optimal Design of ORC Systems with a Low-Temperature Heat Source

    Directory of Open Access Journals (Sweden)

    Nicolas Galanis

    2012-02-01

    Full Text Available A numerical model of subcritical and trans-critical power cycles using a fixed-flowrate low-temperature heat source has been validated and used to calculate the combinations of the maximum cycle pressure (Pev and the difference between the source temperature and the maximum working fluid temperature (DT which maximize the thermal efficiency (ηth or minimize the non-dimensional exergy losses (β, the total thermal conductance of the heat exchangers (UAt and the turbine size (SP. Optimum combinations of Pev and DT were calculated for each one of these four objective functions for two working fluids (R134a, R141b, three source temperatures and three values of the non-dimensional power output. The ratio of UAt over the net power output (which is a first approximation of the initial cost per kW shows that R141b is the better working fluid for the conditions under study.

  3. An ecofriendly graphene-based nanofluid for heat transfer applications

    DEFF Research Database (Denmark)

    Mehrali, Mohammad; Sadeghinezhad, Emad; Akhiani, Amir Reza

    2016-01-01

    including chemical stability, viscosity, wettability, electrical conductivity and thermal conductivity were investigated in a comprehensive manner. A significant thermal conductivity enhancement amounting to 45.1% was obtained for a volume fraction of 4%. In addition, the convective heat transfer...... that the generated nanofluid will open a new avenue in the pursuit of ecofriendly thermal conductors for heat transfer applications....... coefficient of the nanofluid in a laminar flow regime with uniform wall heat flux was investigated to estimate its cooling capabilities. These results, firmly confirm that the generated graphene-based nanofluid is a formidable transporter of heat and yet ecofriendly. Therefore, it's anticipate...

  4. Agent-based modelling of heating system adoption in Norway

    Energy Technology Data Exchange (ETDEWEB)

    Sopha, Bertha Maya; Kloeckner, Christian A.; Hertwich, Edgar G.

    2010-07-01

    Full text: This paper introduces agent-based modelling as a methodological approach to understand the effect of decision making mechanism on the adoption of heating systems in Norway. The model is used as an experimental/learning tool to design possible interventions, not for prediction. The intended users of the model are therefore policy designers. Primary heating system adoptions of electric heating, heat pump and wood pellet heating were selected. Random topology was chosen to represent social network among households. Agents were households with certain location, number of peers, current adopted heating system, employed decision strategy, and degree of social influence in decision making. The overall framework of decision-making integrated theories from different disciplines; customer behavior theory, behavioral economics, theory of planned behavior, and diffusion of innovation, in order to capture possible decision making processes in households. A mail survey of 270 Norwegian households conducted in 2008 was designed specifically for acquiring data for the simulation. The model represents real geographic area of households and simulates the overall fraction of adopted heating system under study. The model was calibrated with historical data from Statistics Norway (SSB). Interventions with respects to total cost, norms, indoor air quality, reliability, supply security, required work, could be explored using the model. For instance, the model demonstrates that a considerable total cost (investment and operating cost) increase of electric heating and heat pump, rather than a reduction of wood pellet heating's total cost, are required to initiate and speed up wood pellet adoption. (Author)

  5. Model-based analysis and simulation of regenerative heat wheel

    DEFF Research Database (Denmark)

    Wu, Zhuang; Melnik, Roderick V. N.; Borup, F.

    2006-01-01

    The rotary regenerator (also called the heat wheel) is an important component of energy intensive sectors, which is used in many heat recovery systems. In this paper, a model-based analysis of a rotary regenerator is carried out with a major emphasis given to the development and implementation of...

  6. IMPACT OF GEOTHERMAL GRADIENT ON GROUND SOURCE HEAT PUMP SYSTEM MODELING

    Directory of Open Access Journals (Sweden)

    Tomislav Kurevija

    2014-07-01

    Full Text Available ndisturbed ground temperature is one of the most crucial thermogeological parameters needed for shallow geothermal resources assessment. Energy considered to be geothermal is energy stored in the ground at depths where solar radiation has no effect. At depth where undisturbed ground temperature occurs there is no influence of seasonal variations in air temperature from surface. Exact temperature value, and depth where it occurs, is functionally dependent on surface climate parameters and thermogeologic properties of ground. After abovementioned depth, increase of ground temperature is solely dependent on geothermal gradient. Accurately determined value of undisturbed ground temperature is beneficial for proper sizing of borehole heat exchangers. On practical example of building which is being heated and cooled with shallow geothermal resource, influences of undisturbed ground temperature and geothermal gradient, on size of borehole heat exchanger are going to be presented. Sizing of borehole heat exchanger was calculated with commercial software Ground Loop Designer (GLD, which uses modified line source and cylinder source solutions of heat conduction in solids.

  7. Analysis and comparison of methods for the preparation of domestic hot water from district heating system, selected renewable and non-renewable sources in low-energy buildings

    Directory of Open Access Journals (Sweden)

    Knapik Maciej

    2018-01-01

    Full Text Available The article presents an economic analysis and comparison of selected (district heating, natural gas, heat pump with renewable energy sources methods for the preparation of domestic hot water in a building with low energy demand. In buildings of this type increased demand of energy for domestic hot water preparation in relation to the total energy demand can be observed. As a result, the proposed solutions allow to further lower energy demand by using the renewable energy sources. This article presents the results of numerical analysis and calculations performed mainly in MATLAB software, based on typical meteorological years. The results showed that system with heat pump and renewable energy sources Is comparable with district heating system.

  8. Analysis and comparison of methods for the preparation of domestic hot water from district heating system, selected renewable and non-renewable sources in low-energy buildings

    Science.gov (United States)

    Knapik, Maciej

    2018-02-01

    The article presents an economic analysis and comparison of selected (district heating, natural gas, heat pump with renewable energy sources) methods for the preparation of domestic hot water in a building with low energy demand. In buildings of this type increased demand of energy for domestic hot water preparation in relation to the total energy demand can be observed. As a result, the proposed solutions allow to further lower energy demand by using the renewable energy sources. This article presents the results of numerical analysis and calculations performed mainly in MATLAB software, based on typical meteorological years. The results showed that system with heat pump and renewable energy sources Is comparable with district heating system.

  9. Thulium heat source for high-endurance and high-energy density power systems

    International Nuclear Information System (INIS)

    Walter, C.E.; Kammeraad, J.E.; Van Konynenburg, R.; VanSant, J.H.

    1991-05-01

    We are studying the performance characteristics of radioisotope heat source designs for high-endurance and high-energy-density power systems that use thulium-170. Heat sources in the power range of 5--50 kW th coupled with a power conversion efficiency of ∼30%, can easily satisfy current missions for autonomous underwater vehicles. New naval missions will be possible because thulium isotope power systems have a factor of one-to-two hundred higher endurance and energy density than chemical and electrochemical systems. Thulium-170 also has several other attractive features, including the fact that it decays to stable ytterbium-170 with a half-life of four months. For terrestrial applications, refueling on that time scale should be acceptable in view of the advantage of its benign decay. The heat source designs we are studying account for the requirements of isotope production, shielding, and integration with power conversion components. These requirements are driven by environmental and safety considerations. Thulium is present in the form of thin refractory thulia disks that allow power conversion at high peak temperature. We give estimates of power system state points, performance, mass, and volume characteristics. Monte Carlo radiation analysis provides a detailed assessment of shield requirements and heat transfer under normal and distressed conditions is also considered. 11 refs., 7 figs., 4 tabs

  10. Effects of the generator and evaporator temperature differences on a double absorption heat transformer—Different control strategies on utilizing heat sources

    International Nuclear Information System (INIS)

    Wang, Hanzhi; Li, Huashan; Bu, Xianbiao; Wang, Lingbao

    2017-01-01

    Highlights: • Effects of the GETD on the DAHT system performance are analyzed. • Three different configurations are compared in detail. • Suggestions on the heat source control strategies are given. - Abstract: The combination of the absorption heat transformer with renewable energy systems, like solar thermal systems, is raising more and more concern. In those combined systems the strategies on utilizing heat sources can affect system thermodynamic performance significantly. Therefore, this study presents a detailed analysis on the effect of the heat source temperature and different heat source flow patterns on the performance of a double absorption heat transformer (DAHT). A detailed comparative study is carried out to clarify the impact of the generator and evaporator temperature differences (GETD) on the coefficient of performance (COP), exergy efficient (ECOP), exergy destruction rates in the individual components and heat transfer areas needed for each component. The results show that the generator, condenser and absorber-evaporator are responsible for most of the exergy destruction rate in the DAHT system; the parallel-flow configuration (the generator temperature is equal to the evaporator temperature) performs better under the high gross temperature lift conditions; in the case of the counter-flow configuration (the generator temperature is relatively higher), better performance can be obtained in both the COP and ECOP under the proper heat source temperature (85 and 95 °C); the fair-flow configuration (higher temperature in the evaporator) is not recommended in this paper due to no advantages found in either thermodynamic performance or system size.

  11. Engineering for high heat loads on ALS [Advanced Light Source] beamlines

    International Nuclear Information System (INIS)

    DiGennaro, R.; Swain, T.

    1989-08-01

    This paper discussed general thermal engineering problems and specific categories of thermal design issues for high photon flux beam lines at the LBL Advanced Light Source: thermal distortion of optical surfaces and elevated temperatures of thermal absorbers receiving synchrotron radiation. A generic design for water-cooled heat absorbers is described for use with ALS photon shutters, beam defining apertures, and heat absorbing masks. Also, results of in- situ measurements of thermal distortion of a water-cooled mirror in a synchrotron radiation beam line are compared with calculated performance estimates. 17 refs., 2 figs

  12. Heat sources for bright-rimmed molecular clouds: CO observations of NGC 7822

    International Nuclear Information System (INIS)

    Elmegreen, B.G.; Dickinson, D.F.; Lada, C.J.

    1978-01-01

    Observations of the 2.6 mm carbon monoxide line in the bright rim NGC 7822 reveal that the peak excitation and column density of the molecule lie in a ridge ahead of the ionization front. Several possibilities for the excitation of this ridge are discussed. Cosmic rays are shown to provide an excellent heat source for Bok globules, but they can account for only approx.20% of the required heating in NGC 7822. Direct shock or compressional heating of the gas could be adequate only if the pressure inside the cloud is much larger than the thermal pressure. If, in fact, this internal pressure is determined by the source of line broadening (e.g., magnetic fields or turbulence), then shock or compressional heating could be important, and pressure equilibrium may exist between the neutral cloud and the bright rim. Heating by warm grains or by the photoelectric effect is also considered, but such mechanisms are probably not important if the only source of radiation is external to the cloud. This is primarily a result of the low cloud density (approx.10 3 cm -3 ) inferred from our observations. The extent to which unknown embedded stars may provide the required gaseous heating cannot be estimated from our observations of NGC 7822.An interesting and new heat source is suggested which may have important applications to bright-rimmed clouds or to any other predominantly neutral clouds that may have undergone some recent compression. We suggest that the heat input to neutral gas due to the relaxation of internal magnetic fields will be greatly enhanced during cloud compression (with or without a shock). We show that the power input to the gas will increase more with increasing density than will the cooling rate. As a result, cloud compression can lead to an increase in the gas temperature for a period lasting several million years, which is the decay time of the compressed field. The observed ridge in NGC 7822 may be due to stimulated release of internal magnetic energy

  13. A Green's function solution for a rectangular heat source on an infinite plate

    International Nuclear Information System (INIS)

    Bainbridge, B.L.

    1989-01-01

    The applications associated with a rectangular heat source on an infinite plate range from integrated circuits to thin film heat flux sensors on thin substrates. The particular problem from which the solution is developed concerns the use of a resistive strip for monitoring currents generated in circuits exposed to electromagnetic fields. The Green's function formulation is solved by using early and late time approximations for which analytical solutions can be derived. In this paper expressions are developed for three sets of boundary conditions and compared to the experimental performance of a physical device

  14. Processing summary report: Fabrication of cesium and strontium heat and radiation sources

    International Nuclear Information System (INIS)

    Holton, L.K. Jr.; Surma, J.E.; Allen, R.P.

    1989-02-01

    The Pacific Northwest Laboratory (PNL), has produced 30 isotopic heat sources (canisters) for the Federal Republic of Germany (FRG) to be used as part of a repository testing program in the Asse Salt Mine. PNL program work involved the filling, closure, and decontamination of the 30 canisters. The canisters were fabricated (filled) in three separate processing campaigns using the radioactive liquid-fed ceramic melter to produce a borosilicate glass. Within the borosilicate glass matrix radiochemical constituents ( 137 Cs and 90 Sr) were immobilized to yield a product with a predetermined decay heat and surface radiation exposure rate

  15. 太阳能辅助地源热泵供暖实验研究%Experimental study of a solar assisted ground source heat pump for heating

    Institute of Scientific and Technical Information of China (English)

    赵忠超; 丰威仙; 巩学梅; 米浩君; 成华; 云龙

    2014-01-01

    An experimental study is performed to determine the performance of the solar assisted ground source heat pump(SAGSHP)by using a solar-ground source heat pump hybrid system in the city of Ningbo. The result shows that comparing with the ground source heat pump(GSHP),when the ratio of solar energy to the whole en-ergy is 41. 9% ,the coefficient of performance( COP)of the heat pump and system can improve 15. 1% and 7. 7% respectively. Therefore,the solar assisted ground source heat pump has a significant performance advan-tage according to the experimental result.%选取宁波某公用建筑的太阳能-地源热泵复合系统为实验系统,对太阳能辅助地源热泵( solar assisted ground source heat pump,SAGSHP)供暖进行了实验研究.研究结果表明:与单一的地源热泵(ground source heat pump,GSHP)相比,当太阳能承担41.9%负荷时,热泵机组和整个系统的能效比(coefficient of performance,COP)分别提高了15.1%和7.7%, SAGSHP 供暖运行模式具有明显的性能优势.

  16. Detailed Theoretical Characterization of a Transcritical CO2 Direct Expansion Ground Source Heat Pump Water Heater

    Directory of Open Access Journals (Sweden)

    Parham Eslami-Nejad

    2018-02-01

    Full Text Available A new avenue in modern heat pump technology is related to the use of natural refrigerants such as carbon dioxide (CO2. The use of CO2 in direct expansion ground source heat pumps (DX-GSHP has also gained significant interest as it offers opportunities for cost reduction of the ground loop, albeit some challenges remain in their development, design and use. To address these challenges and to characterize CO2-DX-GSHP performance for water heating applications, a detailed theoretical model and a fully-instrumented test apparatus was developed and built at CanmetENERGY Research Laboratory. The theoretical model was validated against a set of experimental results and adopted to investigate the performance of the system over a wide operating range. Validation results showed that the model predicts the experimental results within the measurement uncertainty. A detailed system performance analysis was also performed using the theoretical model to understand the system behavior and explore the actions required for performance improvement in future installations. The results of the analysis showed that improper design and control of some components, such as the gas cooler and ground heat exchanger can degrade the system performance by up to 25%, and the heat pump heating capacity by 7.5%.

  17. Thermal energy storage in the form of heat or cold with using of the PCM-based accumulation panels

    Directory of Open Access Journals (Sweden)

    Skovajsa Jan

    2016-01-01

    Full Text Available This article describes the usage of thermal energy storage in the form of heat and cold with an adaptation of the special device which is composed of the thermal panels. These panels are based on the phase change materials (PCM for normal inner environment temperature in buildings. The energy for the thermal energy storage is possible to get from built-in electric heating foil or from the tube heat exchanger, which is build in the thermal panels. This technology is able to use renewable energy sources, for example, solar thermal collectors and air-to-water heat pump as a source of heat for heating of the hot water tank. In the cooling mode, there is able to use the heat pump or photovoltaics panels in combination with thermoelectric coolers for cooling.

  18. Long-term heat storage in calcium sulfoaluminate cement (CSA) based concrete

    Energy Technology Data Exchange (ETDEWEB)

    Kaufmann, Josef P.; Winnefeld, Frank [Empa Swiss Federal Laboratories for Materials Science and Technology, Duebendorf (Switzerland). Lab. for Concrete and Construction Chemistry

    2011-07-01

    In general, the selection of materials proposed for solar heat storage is based on one of two principal processes: sensible heat storage or latent heat storage. Sensible heat storage utilizes the specific heat capacity of a material, while latent heat storage is based on the change in enthalpy (heat content) associated with a phase change of the material. Long time sensible heat storage requires excellent thermal insulation whereas latent heat storage allows permanent (seasonal) storage without significant energy losses and any special insulation. Ettringite, one of the cement hydration products, exhibits a high dehydration enthalpy. Calcium sulfoaluminate cement based concrete containing a high amount of ettringite is henceproposed as an efficient latent heat storage material. Compared to conventional heat storage materials this innovative concrete mixture has a high loss-free storage energy density (> 100-150 kWh/m{sup 3}) which is much higher than the one of paraffin or the (loss-sensitive) sensible heat of water. Like common concrete the CSA-concrete is stable and even may carry loads. The dehydration of the CSA-concrete is achieved at temperatures below 100 C. The rehydration process occurs as soon as water (liquid or vapor) is added. In contrast to paraffin, the phase change temperature is not fixed and the latent heat may be recovered at any desired temperature. Furthermore the heat conductivity of this material is high, so that the energy transfer from/to an exchange medium is easy. Additionally CSA-concrete is not flammable and absolutely safe regarding any health aspects. The cost of such CSA-concrete isin the order of normal concrete. The main application is seen in house heating systems. Solar heat, mostly generated during the summer period by means of roof collectors, can be stored in CSA-concrete until the winter. A part or even the whole annual heatingenergy may be produced and saved locally by the householder himself. Additional applications may be

  19. Cyclotron-based neutron source for BNCT

    Energy Technology Data Exchange (ETDEWEB)

    Mitsumoto, T.; Yajima, S.; Tsutsui, H.; Ogasawara, T.; Fujita, K. [Sumitomo Heavy Industries, Ltd (Japan); Tanaka, H.; Sakurai, Y.; Maruhashi, A. [Kyoto University Research Reactor Institute (Japan)

    2013-04-19

    Kyoto University Research Reactor Institute (KURRI) and Sumitomo Heavy Industries, Ltd. (SHI) have developed a cyclotron-based neutron source for Boron Neutron Capture Therapy (BNCT). It was installed at KURRI in Osaka prefecture. The neutron source consists of a proton cyclotron named HM-30, a beam transport system and an irradiation and treatment system. In the cyclotron, H- ions are accelerated and extracted as 30 MeV proton beams of 1 mA. The proton beams is transported to the neutron production target made by a beryllium plate. Emitted neutrons are moderated by lead, iron, aluminum and calcium fluoride. The aperture diameter of neutron collimator is in the range from 100 mm to 250 mm. The peak neutron flux in the water phantom is 1.8 Multiplication-Sign 109 neutrons/cm{sup 2}/sec at 20 mm from the surface at 1 mA proton beam. The neutron source have been stably operated for 3 years with 30 kW proton beam. Various pre-clinical tests including animal tests have been done by using the cyclotron-based neutron source with {sup 10}B-p-Borono-phenylalanine. Clinical trials of malignant brain tumors will be started in this year.

  20. Impact of source and level of calcium fortification on the heat stability of reconstituted skim milk powder.

    Science.gov (United States)

    Vyas, H K; Tong, P S

    2004-05-01

    Calcium enrichment of food and dairy products has gained interest with the increased awareness about the importance of higher calcium intake. Calcium plays many important roles in the human body. Dairy products are an excellent source of dietary calcium, which can be further fortified with calcium salts to achieve higher calcium intake per serving. However, the addition of calcium salts can destabilize food systems unless conditions are carefully controlled. The effect of calcium fortification on the heat stability of reconstituted skim milk was evaluated, using reconstituted skim milks with 2 protein levels: 1.75 and 3.5% (wt/wt) prepared using low and high heat powders. Calcium carbonate, phosphate, lactate, and citrate were used for fortification at 0.15, 0.18, and 0.24% (wt/wt). Each sample was analyzed for solubility, heat stability, and pH. The addition of phosphate and lactate salts lowered the pH of milk, citrate did not have any major effect, and carbonate for the 1.75% protein samples increased the pH. In general, changes in solubility and heat stability were associated with changes in pH. Calcium addition decreased the solubility and heat stability. However, interestingly, the presence of carbonate salt greatly increased the heat stability for 1.75% protein samples. This is due to the neutralizing effect of calcium carbonate when it goes into solution. The results suggested that the heat stability of milk can be affected by the type of calcium salt used. This may be applied to the development of milk-based calcium enriched beverages.

  1. Ultraviolet light and heat source selection in captive spiny-tailed iguanas (Oplurus cuvieri)

    International Nuclear Information System (INIS)

    Dickinson, H.C.; Fa, J.E.

    1997-01-01

    Three experimental manipulations were conducted to assess the influence of heat source selection and active thermoregulation on ultraviolet (UV) light exposure in captive spiny-tailed iguanas (Oplurus cuvieri) at the Jersey Wildlife Preservation Trust. Four replicates per manipulation were conducted on six individual lizards. All animals were tested in a separate enclosure to which they were acclimated before observations. Data on choice of thermal sources were collected during the first 2 hr of light, when lizards were actively thermoregulating. Animals were allowed to choose between incandescent light, UV light and a non-light heat source (thermotube) in different combinations. Recorded temperatures close to the incandescent light (37°C) were always significantly higher than at the thermotube (33°C) and at the UV light (29°C). Manipulation 1 offered the animals a choice of an UV light and an incandescent light as thermal sources. Manipulation 2 presented animals with the thermal choices in Manipulation 1, but substrates under each source in Manipulation 1 were switched. In Manipulation 3, animals could choose between an incandescent light and the thermotube. All studied lizards were significantly more attracted to the incandescent light than to the UV light or thermotube. Incandescent light elicited a significantly higher proportion of basking behaviors in all individuals than the other sources. A high proportion of time basking was also spent in front of the thermotube but fewer individuals and less time were spent basking under the UV light. Heat source selection was generally found to be independent of substrate. Management applications of this preference are suggested for juvenile diurnal heliothermic iguanids. (author)

  2. Ground source heat pumps versus high efficiency natural gas furnaces in Alberta

    Energy Technology Data Exchange (ETDEWEB)

    Shaw, J.

    2003-02-02

    For the past twenty years or so, the heating and cooling of numerous buildings in northern Europe has been accomplished using ground source heat pumps (GSHPs), while in North America they have been in use for approximately ten years. In the Prairies, natural gas furnaces dominate, while GSHP are more popular in eastern Canada. The author noted that natural gas furnaces have an efficiency of 80 per cent or less, while high efficiency natural gas (HENG) furnaces, more expensive, have an efficiency in the 90 per cent range. A brief outline of the principles behind GSHPs was provided. The Coefficient of Performance (COP) of GSHP reaches up to 500 per cent depending whether the unit is cooling or heating. The amount of heat produced by a heating system expressed as a percentage of the energy input required to operate the system is the definition used for the efficiency. In those cases where it is possible to amortize the initial costs, pay now or obtain a subsidy, the installation of GSHP is advantageous. Several factors affect the total cost of heating a building, such as the airtightness of the building and its insulation, the coldness of the climate, and the inside controlled temperature setting. The author then examined the cost of operating a GSHP versus a natural gas furnace. In most examples studied, the cost of operating a GSHP was less than the cost of operating a natural gas furnace. The Total Equivalent Warming Impact (TEWI) of GSHPs and HENG furnaces was examined. The author concluded that the cost of heating by GSHP in Alberta will be lower than the cost of heating by HENG which requires a separate air conditioning unit for the summer months, with additional improvements in efficiency and insulation. 7 refs., 4 tabs.

  3. Open Source GIS based integrated watershed management

    Science.gov (United States)

    Byrne, J. M.; Lindsay, J.; Berg, A. A.

    2013-12-01

    Optimal land and water management to address future and current resource stresses and allocation challenges requires the development of state-of-the-art geomatics and hydrological modelling tools. Future hydrological modelling tools should be of high resolution, process based with real-time capability to assess changing resource issues critical to short, medium and long-term enviromental management. The objective here is to merge two renowned, well published resource modeling programs to create an source toolbox for integrated land and water management applications. This work will facilitate a much increased efficiency in land and water resource security, management and planning. Following an 'open-source' philosophy, the tools will be computer platform independent with source code freely available, maximizing knowledge transfer and the global value of the proposed research. The envisioned set of water resource management tools will be housed within 'Whitebox Geospatial Analysis Tools'. Whitebox, is an open-source geographical information system (GIS) developed by Dr. John Lindsay at the University of Guelph. The emphasis of the Whitebox project has been to develop a user-friendly interface for advanced spatial analysis in environmental applications. The plugin architecture of the software is ideal for the tight-integration of spatially distributed models and spatial analysis algorithms such as those contained within the GENESYS suite. Open-source development extends knowledge and technology transfer to a broad range of end-users and builds Canadian capability to address complex resource management problems with better tools and expertise for managers in Canada and around the world. GENESYS (Generate Earth Systems Science input) is an innovative, efficient, high-resolution hydro- and agro-meteorological model for complex terrain watersheds developed under the direction of Dr. James Byrne. GENESYS is an outstanding research and applications tool to address

  4. Diffusion induced nuclear reactions in metals: a possible source of heat in the core

    International Nuclear Information System (INIS)

    Hamza, V.M.; Iyer, S.S.S.

    1989-01-01

    It has recently been proposed that diffusion of light nuclei in metals can give rise to unusual electrical charge distributions in their lattice structures, inducing thereby certain nuclear reactions that are otherwise uncommon. In the light of these results we advance the hypothesis that such nuclear reactions take place in the metal rich core of the earth, based on following observations: 1 - The solubility of hydrogen in metals is relatively high compared to that in silicates. 2 - Studies of rare gas samples in intraplate volcanos and diamonds show that 3 He/ He ratio increases with depth in the mantle. 3 - There are indications that He is positively correlated with enrichment of metals in lavas. We propose that hydrogen incorporated into metallic phases at the time of planetary accretion was carried to the core by downward migration of metal rich melts during the early states of proto-earth. Preliminary estimates suggest that cold fusion reactions can give rise to an average rate of heat generation of 8.2x10 12 W and may thus serve as a supplementary source of energy for the geomagnetic dynamo. (author)

  5. Environmental considerations for geothermal energy as a source for district heating

    International Nuclear Information System (INIS)

    Rafferty, K.D.

    1996-01-01

    Geothermal energy currently provides a stable and environmentally attractive heat source for approximately 20 district heating (DH) systems in the US. The use of this resource eliminates nearly 100% of the conventional fuel consumption (and, hence, the emissions) of the loads served by these systems. As a result, geothermal DH systems can rightfully claim the title of the most fuel-efficient DH systems in operation today. The cost of producing heat from a geothermal resource (including capitalization of the production facility and cost for pumping) amounts to an average of $1.00 per million Btu (0.0034 $/kWh). The major environmental challenge for geothermal systems is proper management of the producing aquifer. Many systems are moving toward injection of the geothermal fluids to ensure long-term production

  6. The General-Purpose Heat Source Radioisotope Thermoelectric Generator: Power for the Galileo and Ulysses missions

    International Nuclear Information System (INIS)

    Bennett, G.L.; Lombardo, J.J.; Hemler, R.J.; Peterson, J.R.

    1986-01-01

    Electrical power for NASA's Galileo mission to Jupiter and ESA's Ulysses mission to explore the polar regions of the Sun will be provided by General-Purpose Heat Source Radioisotope Thermo-electric Generators (GPHS-RTGs). Building upon the successful RTG technology used in the Voyager program, each GPHS-RTG will provide at least 285 W(e) at beginning-of-mission. The design concept has been proven through extensive tests of an electrically heated Engineering Unit and a nuclear-heated Qualification Unit. Four flight generators have been successfully assembled and tested for use on the Galileo and Ulysses spacecraft. All indications are that the GPHS-RTGs will meet or exceed the power requirement of the missions

  7. ENERGY STAR Certified Non-AHRI Central Air Conditioner Equipment and Air Source Heat Pump

    Science.gov (United States)

    Certified models meet all ENERGY STAR requirements as listed in the Version 5.0 ENERGY STAR Program Requirements for Air Source Heat Pump and Central Air Conditioner Equipment that are effective as of September 15, 2015. A detailed listing of key efficiency criteria are available at http://www.energystar.gov/index.cfm?c=airsrc_heat.pr_crit_as_heat_pumps Listed products have been submitted to EPA by ENERGY STAR partners that do not participate in the AHRI certification program. EPA will continue to update this list with products that are certified by EPA-recognized certification bodies other than AHRI. The majority of ENERGY STAR products, certified by AHRI, can be found on the CEE/AHRI Verified Directory at http://www.ceedirectory.org/

  8. Ground source heat pump retrofit at North Bonneville, WA City Hall

    Energy Technology Data Exchange (ETDEWEB)

    Hughey, M. [Skamania Co. PUD No. 1, Carson, WA (United States)

    1997-12-31

    In 1995, the City of North Bonneville, WA installed a 10-ton Ground Source Heat Pump (GSHP) to replace the electric resistance furnace in its 4,000 square, foot City Hall. North Bonneville is 30 miles east of Portland, Oregon, at river level in the Columbia River Gorge. Funded jointly by the Bonneville Power Administration, the State of Washington and the City, this project has successfully reduced the heating cost of City Hall by nearly one-half while dramatically increasing comfort. It has become a commercial model in the Pacific Northwest for assessing values of commercial GSHP retrofits. This interim report compares estimated savings with actual experience for the first operating year. Projected savings were $1,500; actual savings were $1,390 prior to adjustment for extreme weather. Adjusted savings for Heating Year 1996 were $1,490, a 47 percent decrease. Maintenance savings (not itemized) were in addition to this amount. Monitoring continues in 1997.

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

    International Nuclear Information System (INIS)

    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

  10. System simulation for an untreated sewage source heat pump (USSHP) in winter

    Science.gov (United States)

    Qin, Na; Hao, Peng Z.

    2017-01-01

    The paper discusses the system characteristics of an untreated sewage source heat pump in winter. In this system, the sewage enters into the evaporator directly. The variable parameters to control the system contain the sewage temperature at evaporator inlet and the water temperature at condenser inlet. It is found that most parameters, except the condensation heat transfer coefficient, change in the form of sine wave the same as the sewage temperature at inlet. The heating load and consumed power are 12.9kW and 3.45kW when the sewage temperature at inlet is 13°C. COP is about 3.75 in the range of the sewage temperature at inlet of 12-13°C.

  11. Moving heat source in a confined channel: Heat transfer and boiling in endovenous laser ablation of varicose veins : Heat transfer and boiling in endovenous laser ablation of varicose veins

    NARCIS (Netherlands)

    de Boer, A.; Oliveira, J.L.G.; van der Geld, C.W.M.; Malskat, Wendy S.J.; van den Bos, Renate; Nijsten, Tamar; van Gemert, M.J.C.

    2017-01-01

    Motion of a moving laser light heat source in a confined volume has important applications such as in endovenous laser ablation (EVLA) of varicose veins. This light heats up the fluid and the wall volume by absorption and heat conduction. The present study compares the flow and temperature fields in

  12. 太阳能耦合地源热泵供暖系统的实验研究%Experimental Study on Heating System of Solar Coupled Ground Source Heat Pump

    Institute of Scientific and Technical Information of China (English)

    智超英; 赵宇含

    2017-01-01

    太阳能耦合地源热泵系统的设计以太阳能为辅助、地源热泵为主,最大化地利用太阳能资源,在满足地板采暖制备的情况下,富裕的热量可以补充到生活用水当中.通过实验验证了太阳能耦合地源热泵供暖系统可以有效恢复土壤温度,提高机组性能系数,实现热泵长期稳定的运行.%The design of solar coupled ground source heat pump system is based on solar energy and ground source heat pump.The system can maximize solar energy utilization in the preparation of floor heating.Rich heat can be added to the life water.This paper introduces the solar coupled ground source heat pump heating system.The experiment proves that the system can effectively restore the soil temperature, improve the performance coefficient of the crew, and realize the long-term stable operation of the heat pump.

  13. Impact of heat source/sink on radiative heat transfer to Maxwell nanofluid subject to revised mass flux condition

    Science.gov (United States)

    Khan, M.; Irfan, M.; Khan, W. A.

    2018-06-01

    Nanofluids retain noteworthy structure that have absorbed attentions of numerous investigators because of their exploration in nanotechnology and nanoscience. In this scrutiny a mathematical computation of 2D flows of Maxwell nanoliquid influenced by a stretched cylinder has been established. The heat transfer structure is conceded out in the manifestation of thermal radiation and heat source/sink. Moreover, the nanoparticles mass flux condition is engaged in this exploration. This newly endorsed tactic is more realistic where the conjecture is made that the nanoparticle flux is zero and nanoparticle fraction regulates itself on the restrictions consequently. By utilizing apposite conversion the governing PDEs are transformed into ODEs and then tackled analytically via HAM. The attained outcomes are plotted and deliberated in aspect for somatic parameters. It is remarked that with an intensification in the Deborah number β diminish the liquid temperature while it boosts for radiation parameter Rd . Furthermore, the concentration of Maxwell liquid has conflicting impact for Brownian motion Nb and thermophoresis parameters Nt .

  14. Combination of air-source heat pumps with liquid desiccant dehumidification of air

    International Nuclear Information System (INIS)

    Zhang Li; Hihara, Eiji; Saikawa, Michiyuki

    2012-01-01

    Highlights: ► We propose a frost-free air-source heat pump system with integrated desiccant. ► The system can provide heating load continuously and humidify room. ► The coefficient of performance of the system is 2.6 at T a = −7 °C and RH = 80%. ► The heating load of solution is 3–4 times larger than cooling load of solution. - Abstract: This paper proposes a frost-free air source heat pump system with integrated liquid desiccant dehumidification, in which frosting can be retarded by dehumidifying air before entering an outdoor heat exchanger. And the water removed from the air is used to humidify a room. Simulation is carried out at a dry-bulb temperature of −7 to 5.5 °C and a relative humidity of 80% depending on the frosting conditions. The results show that the coefficient of performance (COP) is in the range of 2.6–2.9, which is 30–40% higher than that of heat pump heating integrated with an electric heater humidifying system. And it is found that the optimum value of the concentration of lithium chloride aqueous solution is 37% for the frost-free operation mode. Experiments are conducted for liquid desiccant system under low air temperature and high relative humidity conditions. Experimental results show that the dew point of the dehumidified air is decreased by 8 °C and the humidity ratio of the humidified air is kept at 8.1 g kg −1 , which ensures the frost-free operation of the heat pump evaporator and the comfortable level of room humidity simultaneously. The heating load of solution is 3–4.5 times larger than cooling load of solution, which agrees with the assumption given at the part of the simulation. Furthermore, the deviations between the calculated COP LHRU and the experimental results are within 33%.

  15. A strongly heated neutron star in the transient z source MAXI J0556-332

    Energy Technology Data Exchange (ETDEWEB)

    Homan, Jeroen; Remillard, Ronald A. [MIT Kavli Institute for Astrophysics and Space Research, 77 Massachusetts Avenue 37-582D, Cambridge, MA 02139 (United States); Fridriksson, Joel K.; Wijnands, Rudy [Anton Pannekoek Institute for Astronomy, University of Amsterdam, Postbus 94249, 1090 GE Amsterdam (Netherlands); Cackett, Edward M. [Department of Physics and Astronomy, Wayne State University, 666 W. Hancock St., Detroit, MI 48201 (United States); Degenaar, Nathalie [Department of Astronomy, University of Michigan, 500 Church Street, Ann Arbor, MI 48109 (United States); Linares, Manuel [Instituto de Astrofísica de Canarias, c/ Vía Láctea s/n, E-38205 La Laguna, Tenerife (Spain); Lin, Dacheng, E-mail: jeroen@space.mit.edu [Space Science Center, University of New Hampshire, Durham, NH 03824 (United States)

    2014-11-10

    We present Chandra, XMM-Newton, and Swift observations of the quiescent neutron star in the transient low-mass X-ray binary MAXI J0556-332. Observations of the source made during outburst (with the Rossi X-ray Timing Explorer) reveal tracks in its X-ray color-color and hardness-intensity diagrams that closely resemble those of the neutron-star Z sources, suggesting that MAXI J0556-332 had near- or super-Eddington luminosities for a large part of its ∼16 month outburst. A comparison of these diagrams with those of other Z sources suggests a source distance of 46 ± 15 kpc. Fits to the quiescent spectra of MAXI J0556-332 with a neutron-star atmosphere model (with or without a power-law component) result in distance estimates of 45 ± 3 kpc, for a neutron-star radius of 10 km and a mass of 1.4 M {sub ☉}. The spectra show the effective surface temperature of the neutron star decreasing monotonically over the first ∼500 days of quiescence, except for two observations that were likely affected by enhanced low-level accretion. The temperatures we obtain for the fits that include a power law (kT{sub eff}{sup ∞} = 184-308 eV) are much higher than those seen for any other neutron star heated by accretion, while the inferred cooling (e-folding) timescale (∼200 days) is similar to other sources. Fits without a power law yield higher temperatures (kT{sub eff}{sup ∞} = 190-336 eV) and a shorter e-folding time (∼160 days). Our results suggest that the heating of the neutron-star crust in MAXI J0556-332 was considerably more efficient than for other systems, possibly indicating additional or more efficient shallow heat sources in its crust.

  16. Study on hybrid heat source overlap welding of magnesium alloy AZ31B

    International Nuclear Information System (INIS)

    Liang, G.L.; Zhou, G.; Yuan, S.Q.

    2009-01-01

    The magnesium alloy AZ31B was overlap welded by hybrid welding (laser-tungsten inert gas arc). According to the hybrid welding interaction principle, a new heat source model, hybrid welding heat source model, was developed with finite element analysis. At the same time, using a high-temperature metallographical microscope, the macro-appearance and microstructure characteristics of the joint after hybrid overlap welding were studied. The results indicate that the hybrid welding was superior to the single tungsten inert gas welding or laser welding on the aspects of improving the utilized efficiency of the arc and enhancing the absorptivity of materials to laser energy. Due to the energy characteristics of hybrid overlap welding the macro-appearance of the joint was cup-shaped, the top weld showed the hybrid welding microstructure, while, the lower weld showed the typical laser welding microstructure

  17. Study on hybrid heat source overlap welding of magnesium alloy AZ31B

    Energy Technology Data Exchange (ETDEWEB)

    Liang, G.L. [Department of Electromechanical Engineering, Tangshan College, Tangshan 063000 (China)], E-mail: guoliliang@sohu.com; Zhou, G. [School of Material Science and Engineering, Harbin Institute of Technology, Harbin 150001 (China); Yuan, S.Q. [Department of Electromechanical Engineering, Tangshan College, Tangshan 063000 (China)

    2009-01-15

    The magnesium alloy AZ31B was overlap welded by hybrid welding (laser-tungsten inert gas arc). According to the hybrid welding interaction principle, a new heat source model, hybrid welding heat source model, was developed with finite element analysis. At the same time, using a high-temperature metallographical microscope, the macro-appearance and microstructure characteristics of the joint after hybrid overlap welding were studied. The results indicate that the hybrid welding was superior to the single tungsten inert gas welding or laser welding on the aspects of improving the utilized efficiency of the arc and enhancing the absorptivity of materials to laser energy. Due to the energy characteristics of hybrid overlap welding the macro-appearance of the joint was cup-shaped, the top weld showed the hybrid welding microstructure, while, the lower weld showed the typical laser welding microstructure.

  18. Performance comparison of air-source heat pump water heater with different expansion devices

    International Nuclear Information System (INIS)

    Peng, Jing-Wei; Li, Hui; Zhang, Chun-Lu

    2016-01-01

    Highlights: • An air-source heat pump water heater model was developed and validated. • System performance with EEV, capillary tube or short tube orifice were compared. • Short tube orifice is more suitable for heat pump water heater than capillary tube. - Abstract: Air source heat pump water heater (ASHPWH) is designed to work under wide operating conditions. Therefore, both the system and components require higher reliability and stability than ordinary heat pump air-conditioning systems. In this paper, a quasi-steady-state system model of ASHPWH using electronic expansion valve (EEV), capillary tube or short tube orifice as expansion device is developed and validated by a prototype using R134a and scroll compressor, by which the system performance is evaluated and compared at varying water temperature and different ambient temperature. Flow characteristics of those three expansion devices in ASHPWH are comparatively analyzed. Results show that the EEV throttling system performs best. Compared with capillary tube, flow characteristics of short tube orifice are closer to that of EEV and therefore more suitable for ASHPWH. Reliability concern of liquid carryover to the compressor in the system using short tube orifice is investigated as well. Higher superheat or less system refrigerant charge could help mitigate the risk.

  19. Marangoni convection radiative flow of dusty nanoliquid with exponential space dependent heat source

    Directory of Open Access Journals (Sweden)

    Basavarajappa Mahanthesh

    2017-12-01

    Full Text Available The flow of liquids submerged with nanoparticles is of significance to industrial applications, specifically in nuclear reactors and the cooling of nuclear systems to improve energy efficiency. The application of nanofluids in water-cooled nuclear systems can result in a significant improvement of their economic performance and/or safety margins. Therefore, in this paper, Marangoni thermal convective boundary layer dusty nanoliquid flow across a flat surface in the presence of solar radiation is studied. A two phase dusty liquid model is considered. Unlike classical temperature-dependent heat source effects, an exponential space-dependent heat source aspect is considered. Stretching variables are utilized to transform the prevailing partial differential system into a nonlinear ordinary differential system, which is then solved numerically via the Runge-Kutta-Fehlberg approach coupled with a shooting technique. The roles of physical parameters are focused in momentum and heat transport distributions. Graphical illustrations are also used to consider local and average Nusselt numbers. We examined the results under both linear and quadratic variation of the surface temperature. Our simulations established that the impact of Marangoni flow is useful for an enhancement of the heat transfer rate.

  20. Probing the heat sources during thermal runaway process by thermal analysis of different battery chemistries

    Science.gov (United States)

    Zheng, Siqi; Wang, Li; Feng, Xuning; He, Xiangming

    2018-02-01

    Safety issue is very important for the lithium ion battery used in electric vehicle or other applications. This paper probes the heat sources in the thermal runaway processes of lithium ion batteries composed of different chemistries using accelerating rate calorimetry (ARC) and differential scanning calorimetry (DSC). The adiabatic thermal runaway features for the 4 types of commercial lithium ion batteries are tested using ARC, whereas the reaction characteristics of the component materials, including the cathode, the anode and the separator, inside the 4 types of batteries are measured using DSC. The peaks and valleys of the critical component reactions measured by DSC can match the fluctuations in the temperature rise rate measured by ARC, therefore the relevance between the DSC curves and the ARC curves is utilized to probe the heat source in the thermal runaway process and reveal the thermal runaway mechanisms. The results and analysis indicate that internal short circuit is not the only way to thermal runaway, but can lead to extra electrical heat, which is comparable with the heat released by chemical reactions. The analytical approach of the thermal runaway mechanisms in this paper can guide the safety design of commercial lithium ion batteries.

  1. A novel absorption refrigeration cycle for heat sources with large temperature change

    International Nuclear Information System (INIS)

    Yan, Xiaona; Chen, Guangming; Hong, Daliang; Lin, Shunrong; Tang, Liming

    2013-01-01

    To increase the use efficiency of available thermal energy in the waste gas/water, a novel high-efficient absorption refrigeration cycle regarded as an improved single-effect/double-lift configuration is proposed. The improved cycle using an evaporator/absorber (E/A) promotes the coefficient of performance and reduces the irreversible loss. Water–lithium bromide is used as the working pair and a simulation study under the steady working conditions is conducted. The results show that the temperature of waste gas discharged is about 20 °C lower than that of the conventional single-effect cycle and the novel cycle we proposed can achieve more cooling capacity per unit mass of waste gas/water at the simulated working conditions. -- Graphical abstract: Pressure – temperature diagram for water – lithium bromide. Highlights: ► A novel waste heat-driven absorption refrigeration cycle is presented. ► The novel cycle can reject heat at much lower temperature. ► The available temperature range of heat source of the proposed cycle is wider. ► Multiple heat sources with different temperatures can be used in the novel cycle

  2. Heat transfer performance of a pulsating heat pipe charged with acetone-based mixtures

    Science.gov (United States)

    Wang, Wenqing; Cui, Xiaoyu; Zhu, Yue

    2017-06-01

    Pulsating heat pipes (PHPs) are used as high efficiency heat exchangers, and the selection of working fluids in PHPs has a great impact on the heat transfer performance. This study investigates the thermal resistance characteristics of the PHP charged with acetone-based binary mixtures, where deionized water, methanol and ethanol were added to and mixed with acetone, respectively. The volume mixing ratios were 2:1, 4:1 and 7:1, and the heating power ranged from 10 to 100 W with filling ratios of 45, 55, 62 and 70%. At a low filling ratio (45%), the zeotropic characteristics of the binary mixtures have an influence on the heat transfer performance of the PHP. Adding water, which has a substantially different boiling point compared with that of acetone, can significantly improve the anti-dry-out ability inside the PHP. At a medium filling ratio (55%), the heat transfer performance of the PHP is affected by both phase transition characteristics and physical properties of working fluids. At high heating power, the thermal resistance of the PHP with acetone-water mixture is between that with pure acetone and pure water, whereas the thermal resistance of the PHP with acetone-methanol and acetone-ethanol mixtures at mixing ratios of 2:1 and 4:1 is less than that with the corresponding pure fluids. At high filling ratios (62 and 70%), the heat transfer performance of the PHP is mainly determined by the properties of working fluids that affects the flow resistance. Thus, the PHP with acetone-methanol and acetone-ethanol mixtures that have a lower flow resistance shows better heat transfer performance than that with acetone-water mixture.

  3. General-purpose heat source project and space nuclear safety and fuels program. Progress report

    International Nuclear Information System (INIS)

    Maraman, W.J.

    1979-12-01

    This formal monthly report covers the studies related to the use of 238 PuO 2 in radioisotopic power systems carried out for the Advanced Nuclear Systems and Projects Division of the Los Alamos Scientific Laboratory. The two programs involved are general-purpose heat source development and space nuclear safety and fuels. Most of the studies discussed hear are of a continuing nature. Results and conclusions described may change as the work continues

  4. Measuring Modularity in Open Source Code Bases

    Directory of Open Access Journals (Sweden)

    Roberto Milev

    2009-03-01

    Full Text Available Modularity of an open source software code base has been associated with growth of the software development community, the incentives for voluntary code contribution, and a reduction in the number of users who take code without contributing back to the community. As a theoretical construct, modularity links OSS to other domains of research, including organization theory, the economics of industry structure, and new product development. However, measuring the modularity of an OSS design has proven difficult, especially for large and complex systems. In this article, we describe some preliminary results of recent research at Carleton University that examines the evolving modularity of large-scale software systems. We describe a measurement method and a new modularity metric for comparing code bases of different size, introduce an open source toolkit that implements this method and metric, and provide an analysis of the evolution of the Apache Tomcat application server as an illustrative example of the insights gained from this approach. Although these results are preliminary, they open the door to further cross-discipline research that quantitatively links the concerns of business managers, entrepreneurs, policy-makers, and open source software developers.

  5. Base fluid in improving heat transfer for EV car battery

    Science.gov (United States)

    Bin-Abdun, Nazih A.; Razlan, Zuradzman M.; Shahriman, A. B.; Wan, Khairunizam; Hazry, D.; Ahmed, S. Faiz; Adnan, Nazrul H.; Heng, R.; Kamarudin, H.; Zunaidi, I.

    2015-05-01

    This study examined the effects of base fluid (as coolants) channeling inside the heat exchanger in the process of the increase in thermal conductivity between EV car battery and the heat exchanger. The analysis showed that secondary cooling system by means of water has advantages in improving the heat transfer process and reducing the electric power loss on the form of thermal energy from batteries. This leads to the increase in the efficiency of the EV car battery, hence also positively reflecting the performance of the EV car. The present work, analysis is performed to assess the design and use of heat exchanger in increasing the performance efficiency of the EV car battery. This provides a preface to the use this design for nano-fluids which increase and improve from heat transfer.

  6. Energy Efficiency Modelling of Residential Air Source Heat Pump Water Heater

    Directory of Open Access Journals (Sweden)

    Cong Toan Tran

    2016-03-01

    Full Text Available The heat pump water heater is one of the most energy efficient technologies for heating water for household use. The present work proposes a simplified model of coefficient of performance and examines its predictive capability. The model is based on polynomial functions where the variables are temperatures and the coefficients are derived from the Australian standard test data, using regression technics. The model enables to estimate the coefficient of performance of the same heat pump water heater under other test standards (i.e. US, Japanese, European and Korean standards. The resulting estimations over a heat-up phase and a full test cycle including a draw off pattern are in close agreement with the measured data. Thus the model allows manufacturers to avoid the need to carry out physical tests for some standards and to reduce product cost. The limitations of the methodology proposed are also discussed.

  7. Heat source component development program. Quarterly report for April--June 1977

    Energy Technology Data Exchange (ETDEWEB)

    Foster, E.L. Jr. (comp.)

    1977-07-01

    This is the third in a series of quarterly reports describing the results of several experimental programs being conducted at Battelle-Columbus to develop components for advanced radioisotope heat source applications. The heat sources will for the most part be used in advanced static and dynamic power conversion systems. The specific component development efforts which are described include: improved selective and nonselective vents for helium release from the fuel containment; an improved reentry member and an improved impact member, singly and combined. The unitized reentry-impact member (RIM) is under development to be used as a bifunctional ablator. The development of a unitized reentry-impact member (RIM) has been stopped and the efforts are being redirected to the evaluation of materials that could be used in the near term for the module housing of the General Purpose Heat Source (GPHS). This redirection will be particularly felt in the selection of (improved) materials for reentry analysis and in the experimental evaluation of materials in impact tests. Finally thermochemical supporting studies are reported.

  8. The epoch of cosmic heating by early sources of X-rays

    Science.gov (United States)

    Eide, Marius B.; Graziani, Luca; Ciardi, Benedetta; Feng, Yu; Kakiichi, Koki; Di Matteo, Tiziana

    2018-05-01

    Observations of the 21 cm line from neutral hydrogen indicate that an epoch of heating (EoH) might have preceded the later epoch of reionization. Here we study the effects on the ionization state and the thermal history of the intergalactic medium (IGM) during the EoH induced by different assumptions on ionizing sources in the high-redshift Universe: (i) stars; (ii) X-ray binaries (XRBs); (iii) thermal bremsstrahlung of the hot interstellar medium (ISM); and (iv) accreting nuclear black holes (BHs). To this aim, we post-process outputs from the (100 h-1 comoving Mpc)3 hydrodynamical simulation MassiveBlack-II with the cosmological 3D radiative transfer code CRASH, which follows the propagation of ultraviolet and X-ray photons, computing the thermal and ionization state of hydrogen and helium through the EoH. We find that stars determine the fully ionized morphology of the IGM, while the spectrally hard XRBs pave way for efficient subsequent heating and ionization by the spectrally softer ISM. With the seeding prescription in MassiveBlack-II, BHs do not contribute significantly to either ionization or heating. With only stars, most of the IGM remains in a cold state (with a median T = 11 K at z = 10), however, the presence of more energetic sources raises the temperature of regions around the brightest and more clustered sources above that of the cosmic microwave background, opening the possibility to observing the 21 cm signal in emission.

  9. Ultrasonic inspection of the strength member weld of transit and pioneer heat sources

    International Nuclear Information System (INIS)

    Dudley, W.A.

    1975-01-01

    A nondestructive technique was developed which allows ultrasonic inspection of the closure weld for the strength member component in plutonium-238 radioisotopic heat sources. The advantage of the ultrasonic approach, over that of the more commonly used radiographic one, is the recognized superiority of ultrasonic testing for identifying lack-of-weld penetration (LOP) when accompanied by incomplete diffusion bonding. The ultrasonic technique, a transverse mode scan of the weld for detection of LOP, is primarily accomplished by use of a holding fixture which permits the vented heat source to be immersed into an inspection tank. The mechanical portion of the scanning system is a lathe modified with an inspection tank and a manipulator. This scanning system has been used in the past to inspect SNAP-27 heat sources. The analyzer-transducer combination used in the inspection is capable of detecting a channel type flaw with a side wall depth of 0.076 mm (0.003 in.) in a weld standard. (U.S.)

  10. Design evolution and verification of the general-purpose heat source

    International Nuclear Information System (INIS)

    Schock, A.

    The General-Purpose Heat Source (GPHS) is a radioisotope heat source for use in space power systems. It employs a modular design, to make it adaptable to a wide range of energy conversion systems and power levels. Each 250 W module is completely autonomous, with its own passive safety provisions to prevent fuel release under all abort modes, including atmospheric reentry and earth impact. Prior development tests had demonstrated good impact survival as long as the iridium fuel capsules retained their ductility. This requires high impact temperatures, typically above 900 0 C and reasonably fine grain size, which in turn requires avoidance of excessive operating temperatures and reentry temperatures. These three requirements - on operating, reentry, and impact temperatures - are in mutual conflict, since thermal design changes to improve any one of these temperatures tend to worsen one or both of the others. This conflict creates a difficult design problem, which for a time threatened the success of the program. The present paper describes how this problem was overcome by successive design revisions, supplemented by thermal analyses and confirmatory vibration and impact tests; and how this may be achieved while raising the specific power of the GPHS to 83 W/lb, a 50% improvement over previously flown radioisotope heat sources

  11. Space Launch System Base Heating Test: Experimental Operations & Results

    Science.gov (United States)

    Dufrene, Aaron; Mehta, Manish; MacLean, Matthew; Seaford, Mark; Holden, Michael

    2016-01-01

    NASA's Space Launch System (SLS) uses four clustered liquid rocket engines along with two solid rocket boosters. The interaction between all six rocket exhaust plumes will produce a complex and severe thermal environment in the base of the vehicle. This work focuses on a recent 2% scale, hot-fire SLS base heating test. These base heating tests are short-duration tests executed with chamber pressures near the full-scale values with gaseous hydrogen/oxygen engines and RSRMV analogous solid propellant motors. The LENS II shock tunnel/Ludwieg tube tunnel was used at or near flight duplicated conditions up to Mach 5. Model development was based on the Space Shuttle base heating tests with several improvements including doubling of the maximum chamber pressures and duplication of freestream conditions. Test methodology and conditions are presented, and base heating results from 76 runs are reported in non-dimensional form. Regions of high heating are identified and comparisons of various configuration and conditions are highlighted. Base pressure and radiometer results are also reported.

  12. Effect of heat radiation in a Walter’s liquid B fluid over a stretching sheet with non-uniform heat source/sink and elastic deformation

    Directory of Open Access Journals (Sweden)

    A.K. Abdul Hakeem

    2014-07-01

    Full Text Available In this present article heat transfer in a Walter’s liquid B fluid over an impermeable stretching sheet with non-uniform heat source/sink, elastic deformation and radiation are reported. The basic boundary layer equations for momentum and heat transfer, which are non-linear partial differential equations, are converted into non-linear ordinary differential equations by means of similarity transformation. The dimensionless governing equations for this investigation are solved analytically using hyper geometric functions. The results are carried out for prescribed surface temperature (PST and prescribed power law surface heat flux (PHF. The effects of viscous dissipation, Prandtl number, Eckert number, heat source/sink parameter with elastic deformation and radiation are shown in the several plots and addressed.

  13. Optimization of systems with the combination of ground-source heat pump and solar collectors in dwellings

    DEFF Research Database (Denmark)

    Kjellsson, Elisabeth; Hellström, Göran; Perers, Bengt

    2010-01-01

    The use of ground-source heat pumps for heating and domestic hot water in dwellings is common in Sweden. The combination with solar collectors has been introduced to reduce the electricity demand in the system. In order to analyze different systems with combinations of solar collectors and ground......-source heat pumps, computer simulations have been carried out with the simulation program TRNSYS. Large differences were found between the system alternatives. The optimal design is when solar heat produces domestic hot water during summertime and recharges the borehole during wintertime. The advantage...... is related to the rate of heat extraction from the borehole as well as the overall design of the system. The demand of electricity may increase with solar recharging, because of the increased operating time of the circulation pumps. Another advantage with solar heat in combination with heat pumps is when...

  14. Case Study for the ARRA-funded Ground Source Heat Pump Demonstration at Denver Museum of Nature & Science

    Energy Technology Data Exchange (ETDEWEB)

    Im, Piljae [ORNL; Liu, Xiaobing [ORNL

    2016-09-01

    High initial costs and lack of public awareness of ground-source heat pump (GSHP) technology are the two major barriers preventing rapid deployment of this energy-saving technology in the United States. Under the American Recovery and Reinvestment Act (ARRA), 26 GSHP projects were competitively selected and carried out to demonstrate the benefits of GSHP systems and innovative technologies for cost reduction and/or performance improvement. This report highlights the findings of a case study of one such GSHP demonstration projects that uses a recycled water heat pump (RWHP) system installed at the Denver Museum of Nature & Science in Denver, Colorado. The RWHP system uses recycled water from the city’s water system as the heat sink and source for a modular water-to-water heat pump (WWHP). This case study was conducted based on the available measured performance data from December 2014 through August 2015, utility bills of the building in 2014 and 2015, construction drawings, maintenance records, personal communications, and construction costs. The annual energy consumption of the RWHP system was calculated based on the available measured data and other related information. It was compared with the performance of a baseline scenario— a conventional VAV system using a water-cooled chiller and a natural gas fired boiler, both of which have the minimum energy efficiencies allowed by ASHRAE 90.1-2010. The comparison was made to determine energy savings, operating cost savings, and CO2 emission reductions achieved by the RWHP system. A cost analysis was performed to evaluate the simple payback of the RWHP system. Summarized below are the results of the performance analysis, the learned lessons, and recommended improvement in the operation of the RWHP system.

  15. Marangoni convection in Casson liquid flow due to an infinite disk with exponential space dependent heat source and cross-diffusion effects

    Science.gov (United States)

    Mahanthesh, B.; Gireesha, B. J.; Shashikumar, N. S.; Hayat, T.; Alsaedi, A.

    2018-06-01

    Present work aims to investigate the features of the exponential space dependent heat source (ESHS) and cross-diffusion effects in Marangoni convective heat mass transfer flow due to an infinite disk. Flow analysis is comprised with magnetohydrodynamics (MHD). The effects of Joule heating, viscous dissipation and solar radiation are also utilized. The thermal and solute field on the disk surface varies in a quadratic manner. The ordinary differential equations have been obtained by utilizing Von Kármán transformations. The resulting problem under consideration is solved numerically via Runge-Kutta-Fehlberg based shooting scheme. The effects of involved pertinent flow parameters are explored by graphical illustrations. Results point out that the ESHS effect dominates thermal dependent heat source effect on thermal boundary layer growth. The concentration and temperature distributions and their associated layer thicknesses are enhanced by Marangoni effect.

  16. Characterization of zeolite-based coatings for adsorption heat pumps

    CERN Document Server

    Freni, Angelo; Bonaccorsi, Lucio; Chmielewski, Stefanie; Frazzica, Andrea; Calabrese, Luigi; Restuccia, Giovanni

    2015-01-01

    This book proposes a radically new approach for characterizing thermophysical and mechanical properties of zeolite-based adsorbent coatings for Adsorptive Heat Transformers (AHT). It presents a developed standard protocol for the complete characterization of advanced coated adsorbers. Providing an in-depth analysis of the different procedures necessary for evaluating the performance of adsorbers, it also presents an analysis of their stability under the hydrothermal and mechanical stresses during their entire life cycle. Adsorptive Heat Transformers (AHT), especially adsorption chillers and

  17. Existing climate data sources and Their Use in Heat IslandResearch

    Energy Technology Data Exchange (ETDEWEB)

    Akbari, Hashem; Pon, Brian; Smith, Craig Kenton; Stamper-Kurn, Dan Moses

    1998-10-01

    Existing climate data sources can be used in two general types of analysis for the detection of urban heat islands. Historical analyses use long-term data records-preferentially from several locations in and around an urban area-to trace the gradual influence of urban development on its climate. Primary sources of such data include the cooperative network, first-order National Weather Service stations, and military weather stations. Analyses of short-term data use information from a dense urban weather station network to discern the location, extent, and magnitude of urban heat islands. Such analyses may use the aforementioned national networks or regional networks such as agricultural, air quality monitoring, or utility networks. We demonstrate the use of existing data sources with a historical analysis of temperature trends in Los Angeles, California, and an analysis of short-term data of the urban temperature profile for Phoenix, Arizona. The Los Angeles climate was examined with eleven long-term data records from the cooperative network. Statistically significant trends of rising temperature were detected at Los Angeles Civic Center and other stations over some parts of the year, although timing of the increase varied from station to station. Observed increases in temperatures maybe due to long-term climate changes, microclimate influences, or local-scale heat islands. The analysis of short-term data was made for Phoenix using the PRISMS station network. Mean diurnal temperature profiles for a month were examined and compared with those for adjacent rural areas. Data fi-om stations in the center of Phoenix showed clear and significant nighttime and daytime temperature differences of 1- 2K (3 - 4"F). These temperature increases maybe attributable to a local-scale heat island.

  18. X radiation sources based on accelerators

    International Nuclear Information System (INIS)

    Couprie, M.E.; Filhol, J.M.

    2008-01-01

    Light sources based on accelerators aim at producing very high brilliance coherent radiation, tunable from the infrared to X-ray range, with picosecond or femtosecond light pulses. The first synchrotron light sources were built around storage rings in which a large number of relativistic electrons produce 'synchrotron radiation' when their trajectory is subjected to a magnetic field, either in bending magnets or in specific insertion devices (undulators), made of an alternating series of magnets, allowing the number of curvatures to be increased and the radiation to be reinforced. These 'synchrotron radiation' storage rings are now used worldwide (there are more than thirty), and they simultaneously distribute their radiation to several tens of users around the storage ring. The most effective installations in term of brilliance are the so-called third generation synchrotron radiation light sources. The radiation produced presents pulse durations of the order of a few tens of ps, at a high rate (of the order of MHz); it is tunable over a large range, depending on the magnetic field and the electron beam energy and its polarisation is adjustable (in the V-UV-soft-X range). Generally, a very precise spectral selection is made by the users with a monochromator. The single pass linear accelerators can produce very short electron bunches (around 100 fs). The beam of very high electronic density is sent into successive undulator modules, reinforcing the radiation's longitudinal coherence, produced according to a Free Electron Laser (FEL) scheme by the interaction between the electron bunch and a light wave. The very high peak brilliance justifies their designation as fourth generation sources. The number of users is smaller because an electron pulse produces a radiation burst towards only one beamline. Energy Recovery Linacs (ERL) let the beam pass several times in the accelerator structures either to recover the energy or to accelerate the electrons during several turns

  19. Heat Retreat Locations in Cities - The Survey-Based Location Analysis of Heat Relief

    Science.gov (United States)

    Neht, Alice; Maximini, Claudia; Prenger-Berninghoff, Kathrin

    2017-12-01

    The adaptation of cities to climate change effects is one of the major strategies in urban planning to encounter the challenges of climate change (IPCC 2014). One of the fields of climate change adaption is dealing with heat events that occur more frequently and with greater intensity. Cities in particular are vulnerable to these events due to high population and infrastructure density. Proceeding urbanization calls for the existence of sufficient heat retreat locations (HRL) to enable relief for the population from heat in summer. This is why an extensive analysis of HRL is needed. This paper aims at the development of a survey-based location analysis of heat relief by identifying user groups, locations and characteristics of HRL based on a home survey that was conducted in three German cities. Key results of the study show that the majority of the participants of the survey are users of existing HRL, are affected by heat, and perceive heat as a burden in summer. Moreover, HRL that are located in close proximity are preferred by most users while their effect depends on the regional context that has to be considered in the analysis. Hence, this research presents an approach to heat relief that underlines the importance of HRL in cities by referring to selected examples of HRL types in densely populated areas of cities. HRL should especially be established and secured in densely built-up areas of cities. According to results of the survey, most HRL are located in public spaces, and the overall accessibility of HRL turned out to be an issue.

  20. A review of the cylindrical heat source method for the design and analysis of vertical ground-coupled heat pump systems

    Energy Technology Data Exchange (ETDEWEB)

    Bernier, M. [Ecole Polytechnique, Montreal, PQ (Canada). Dept. de Genie Mecanique

    2000-12-01

    The successful design and analysis of ground-coupled heat pump (GCHP) systems depends in large part on the adequate prediction of ground water heat transfer. The author presented a detailed review of the cylindrical heat source method utilized for the prediction of transient heat transfer in vertical U-tube ground heat exchangers. The physics that underlies the theory applicable to this technology is explained in a step-by-step manner. Explanations are also provided for the equations that govern the determination of design lengths for the cylindrical heat method, as presented in the ASHRAE handbook. Some improvements were recommended by the author, such as the calculation of the effective thermal resistances using the borehole diameter instead of the equivalent U-tube diameter now in use. Annual hour-by-hour building load calculations should be used to calculate ground loads. 8 refs., 2 tabs., 5 figs., 3 appendices.

  1. Problems of heat sources modeling on stage of isolated power systems expansion planning

    International Nuclear Information System (INIS)

    Malenkov, A.V.; Reshetnikova, L.N.; Sergeev, Yu.A.

    1998-01-01

    It is necessary to use computer codes for evaluation of possible applications and role of nuclear district heating plants in the local self-balancing power and heating systems, which are to be located in the remote isolated and hardly accessible regions in the Far North of Russia. Key factors in determining system configurations and its performances are: (1) interdependency of electricity, heat and fuel supply; (2) long distance between energy consumer centres (from several tens up to some hundred kilometers); and (3) difficulty in export and import of the electricity, especially the fuel in and from neighbouring and remote regions. The problem to challenge is to work out an optimum expansion plan of the local electricity and heat supply system. The ENPEP (ENergy and Power Evaluation Program) software package, which was developed by IAEA together with the USA Argonne National Laboratory, was chosen for this purpose. The Chaun-Bilibino power system (CBPS), an isolated power system in far North-East region of Russia, was selected as the first case of the ENPEP study. ENPEP allows a complex approach in the system expansion optimization planning in the time frame of planning period of up to 30 years. The key ENPEP module, ELECTRIC, considers electricity as the only product. The cogeneration part (heat production) must be considered outside the ELECTRIC model and then the results to be transfer ed to ELECTRIC. The ENPEP study on the Chaun-Bilibino isolated power system has shown that the modelling of the heat supply sources in ENPEP is not a trivial problem. It is very important and difficult to correctly represent specific features of cogeneration process at the same time. (author)

  2. Plasma-based EUV light source

    Science.gov (United States)

    Shumlak, Uri; Golingo, Raymond; Nelson, Brian A.

    2010-11-02

    Various mechanisms are provided relating to plasma-based light source that may be used for lithography as well as other applications. For example, a device is disclosed for producing extreme ultraviolet (EUV) light based on a sheared plasma flow. The device can produce a plasma pinch that can last several orders of magnitude longer than what is typically sustained in a Z-pinch, thus enabling the device to provide more power output than what has been hitherto predicted in theory or attained in practice. Such power output may be used in a lithography system for manufacturing integrated circuits, enabling the use of EUV wavelengths on the order of about 13.5 nm. Lastly, the process of manufacturing such a plasma pinch is discussed, where the process includes providing a sheared flow of plasma in order to stabilize it for long periods of time.

  3. Synchrotron based spallation neutron source concepts

    International Nuclear Information System (INIS)

    Cho, Y.

    1998-01-01

    During the past 20 years, rapid-cycling synchrotrons (RCS) have been used very productively to generate short-pulse thermal neutron beams for neutron scattering research by materials science communities in Japan (KENS), the UK (ISIS) and the US (IPNS). The most powerful source in existence, ISIS in the UK, delivers a 160-kW proton beam to a neutron-generating target. Several recently proposed facilities require proton beams in the MW range to produce intense short-pulse neutron beams. In some proposals, a linear accelerator provides the beam power and an accumulator ring compresses the pulse length to the required ∼ 1 micros. In others, RCS technology provides the bulk of the beam power and compresses the pulse length. Some synchrotron-based proposals achieve the desired beam power by combining two or more synchrotrons of the same energy, and others propose a combination of lower and higher energy synchrotrons. This paper presents the rationale for using RCS technology, and a discussion of the advantages and disadvantages of synchrotron-based spallation sources

  4. An experimental study on defrosting heat supplies and energy consumptions during a reverse cycle defrost operation for an air source heat pump

    International Nuclear Information System (INIS)

    Dong Jiankai; Deng Shiming; Jiang Yiqiang; Xia Liang; Yao Yang

    2012-01-01

    For a space heating air source heat pump (ASHP) unit, when its outdoor coil surface temperature is below both the air dew point temperature and the freezing point of water, frost will form on its outdoor coil surface. Frosting affects its operational performance and energy efficiency. Therefore, periodic defrosting is necessary. Currently, the most widely used standard defrosting method for ASHP units is reverse cycle defrost. The energy that should have been used for space heating is used to melt frost, vaporize the melted frost off outdoor coil surface and heat ambient air during defrosting. It is therefore necessary to study the sources of heat supplies and the end-uses of the heat supplied during a reverse cycle defrost operation. In this paper, firstly, an experimental setup is described and experimental procedures are detailed. This is followed by reporting the experimental results and the evaluation of defrosting efficiency for the experimental ASHP unit. Finally, an evaluation of defrosting heat supplies and energy consumptions during a revere cycle defrost operation for the experimental ASHP unit is presented. The experimental and evaluation results indicated that the heat supply from indoor air contributed to 71.8% of the total heat supplied for defrosting and 59.4% of the supplied energy was used for melting frost. The maximum defrosting efficiency could be up to 60.1%. - Highlights: ► Heat supply and consumption during reverse cycle defrost was experimentally studied. ► Indoor air contributed to >70% of total heat supply when indoor fan was turned on. ► ∼60% of the supplied energy was used for melting frost. ► Alternate heat supply other than indoor air should be explored.

  5. Nondestructive inspection of General Purpose Heat Source (GPHS) fueled clad girth welds

    International Nuclear Information System (INIS)

    Reimus, M. A. H.; George, T. G.; Lynch, C.; Padilla, M.; Moniz, P.; Guerrero, A.; Moyer, M. W.; Placr, A.

    1998-01-01

    The General-Purpose Heat Source (GPHS) provides power for space missions by transmitting the heat of 238 Pu decay to an array of thermoelectric elements. The GPHS is fabricated using an iridium-alloy to contain the 238 PuO 2 fuel pellet. GPHS capsules will be utilized in the upcoming Cassini mission to explore Saturn and its moons. The physical integrity of the girth weld is important to mission safety and performance. Because past experience had revealed a potential for initiation of small cracks in the girth weld overlap zone, a nondestructive inspection of each capsule weld is required. An ultrasonic method was used to inspect the welds of capsules fabricated for the Galileo mission. The instrument, transducer, and method used were state of the art at the time (early 1980s). The ultrasonic instrumentation and methods used to inspect the Cassini GPHSs was significantly upgraded from those used for the Galileo mission. GPHSs that had ultrasonic reflectors in excess of the reject specification level were subsequently inspected with radiography to provide additional engineering data used to accept/reject the heat source. This paper describes the Galileo-era ultrasonic instrumentation and methods and the subsequent upgrades made to support testing of Cassini GPHSs. Also discussed is the data obtained from radiographic examination and correlation to ultrasonic examination results

  6. Nondestructive inspection of General Purpose Heat Source (GPHS) fueled clad girth welds

    International Nuclear Information System (INIS)

    Reimus, M.A.; George, T.G.; Lynch, C.; Padilla, M.; Moniz, P.; Guerrero, A.; Moyer, M.W.; Placr, A.

    1998-01-01

    The General-Purpose Heat Source (GPHS) provides power for space missions by transmitting the heat of 238 Pu decay to an array of thermoelectric elements. The GPHS is fabricated using an iridium-alloy to contain the 238 PuO 2 fuel pellet. GPHS capsules will be utilized in the upcoming Cassini mission to explore Saturn and its moons. The physical integrity of the girth weld is important to mission safety and performance. Because past experience had revealed a potential for initiation of small cracks in the girth weld overlap zone, a nondestructive inspection of each capsule weld is required. An ultrasonic method was used to inspect the welds of capsules fabricated for the Galileo mission. The instrument, transducer, and method used were state of the art at the time (early 1980s). The ultrasonic instrumentation and methods used to inspect the Cassini GPHSs was significantly upgraded from those used for the Galileo mission. GPHSs that had ultrasonic reflectors in excess of the reject specification level were subsequently inspected with radiography to provide additional engineering data used to accept/reject the heat source. This paper describes the Galileo-era ultrasonic instrumentation and methods and the subsequent upgrades made to support testing of Cassini GPHSs. Also discussed is the data obtained from radiographic examination and correlation to ultrasonic examination results. copyright 1998 American Institute of Physics

  7. General-Purpose Heat Source Development: Safety Test Program. Postimpact evaluation, Design Iteration Test 3

    International Nuclear Information System (INIS)

    Schonfeld, F.W.; George, T.G.

    1984-07-01

    The General-Purpose Heat Source(GPHS) provides power for space missions by transmitting the heat of 238 PuO 2 decay to thermoelectric elements. Because of the inevitable return of certain aborted missions, the heat source must be designed and constructed to survive both re-entry and Earth impact. The Design Iteration Test (DIT) series is part of an ongoing test program. In the third test (DIT-3), a full GPHS module was impacted at 58 m/s and 930 0 C. The module impacted the target at an angle of 30 0 to the pole of the large faces. The four capsules used in DIT-3 survived impact with minimal deformation; no internal cracks other than in the regions indicated by Savannah River Plant (SRP) preimpact nondestructive testing were observed in any of the capsules. The 30 0 impact orientation used in DIT-3 was considerably less severe than the flat-on impact utilized in DIT-1 and DIT-2. The four capsules used in DIT-1 survived, while two of the capsules used in DIT-2 breached; a small quantity (approx. = 50 μg) of 238 PuO 2 was released from the capsules breached in the DIT-2 impact. All of the capsules used in DIT-1 and DIT-2 were severely deformed and contained large internal cracks. Postimpact analyses of the DIT-3 test components are described, with emphasis on weld structure and the behavior of defects identified by SRP nondestructive testing

  8. Focus group discussions among owners and non-owners of ground source heat pumps

    Energy Technology Data Exchange (ETDEWEB)

    Roberson, B.F.

    1988-07-01

    This research was sponsored by the Office of Buildings and Community Systems and conducted by the Pacific Northwest Laboratory as part of an ongoing effort to enhance the commercial use of federally developed technology. Federal dollars have supported research on the development of ground source heat pumps (GSHP) for several years. Though several companies currently sell GSHP's for residential use, their share of the total heating and air conditioning business remains less than one percent. Large manufacturing companies with national distribution have not yet added GSHP equipment to their product line. GSHP's use only about one half (Braud 1987) to one third (Bose 1987) of the energy needed to operate conventional furnaces and air conditioners. Consequently, a high level of market penetration by the GSHP offers direct benefits to both utility companies and individual users of the systems. Widespread use of these highly efficient systems will reduce both total energy consupmtion, and problems associated with high levels of energy use during peak periods. This will allow utility companies to delay capital expenditures for new facilities to meet the growing energy demand during peak periods. The cost effective use of electricity also reduces the likelihood of homeowners switching to a different fuel source for heating. 5 refs.

  9. Transient natural ventilation of a room with a distributed heat source

    Science.gov (United States)

    Fitzgerald, Shaun D.; Woods, Andrew W.

    We report on an experimental and theoretical study of the transient flows which develop as a naturally ventilated room adjusts from one temperature to another. We focus on a room heated from below by a uniform heat source, with both high- and low-level ventilation openings. Depending on the initial temperature of the room relative to (i) the final equilibrium temperature and (ii) the exterior temperature, three