WorldWideScience

Sample records for direct-expansion solar-assisted heat

  1. Use of solar assisted absorption heat pumps

    Energy Technology Data Exchange (ETDEWEB)

    Lazzarin, R.

    An absorption system can be used for both ambient cooling and heating by solar energy. Heating by an absorption heat pump can represent an interesting alternative, especially in the countries where electric power is not always easily available. Some machines available on the market have been tested. The COP behavior and heating capacity have been examined as a function of the cold source temperature and with regard to different thermal levels. The COP has reached 1.7. Some simulations have been carried out - with two different climatic conditions - to compare the performances of various ''conventional'' solar installation types with solar assisted absorption heat pumps. The series system has shown better performances, 25% to 75%, in comparison with the simpler solar installation. 16 refs.

  2. Solar Assisted Heat Pump Study for Heating of Military Facilities.

    Science.gov (United States)

    1978-07-01

    This study identified 21 generic solar assisted heat pump systems and subjectively evaluated them. The six most promising systems were evaluated in... heat pump . Preliminary drawings intergrating this system into a family housing unit at Little Rock AFB were developed. The system selected had a 27-32 year pay back. (Author)

  3. Investigation of direct expansion in ground source heat pumps

    Science.gov (United States)

    Kalman, M. D.

    A fully instrumented subscale ground coupled heat pump system was developed, and built, and used to test and obtain data on three different earth heat exchanger configurations under heating conditions (ground cooling). Various refrigerant flow control and compressor protection devices were tested for their applicability to the direct expansion system. Undistributed Earth temperature data were acquired at various depths. The problem of oil return at low evaporator temperatures and low refrigerant velocities was addressed. An analysis was performed to theoretically determine what evaporator temperature can be expected with an isolated ground pipe configuration with given length, pipe size, soil conditions and constant heat load. Technical accomplishments to data are summarized.

  4. Solar-assisted heat pump research and development

    Energy Technology Data Exchange (ETDEWEB)

    Day, A.R.; Karayiannis, T.G. (South Bank Univ., London (United Kingdom). School of Engineering and Design)

    1994-01-01

    The main findings of a detailed literature search on solar-assisted heat pumps (SAHP) are presented. The various system types are described and the relevant performance criteria by which systems can be assessed are defined. While most work in the literature has focused on series systems there is no evidence that these can compete with parallel systems, either in non-purchased energy delivery or, more significantly, in cost. Efforts to improve control strategies for series systems are unable to achieve better performance. Technology is sufficiently advanced to exploit the best of these systems if the economic climate becomes favourable. Some suggestions are advanced as to where future research effort can make a useful contribution. (author)

  5. Development of hybrid solar-assisted cooling/heating system

    KAUST Repository

    Huang, B.J.

    2010-08-01

    A solar-assisted ejector cooling/heating system (SACH) was developed in this study. The SACH combines a pump-less ejector cooling system (ECS) with an inverter-type heat pump (R22) and is able to provide a stable capacity for space cooling. The ECS is driven by solar heat and is used to cool the condenser of the R22 heat pump to increase its COP and reduce the energy consumption of the compressor by regulating the rotational speed of the compressor through a control system. In a complete SACH system test run at outdoor temperature 35 °C, indoor temperature 25 °C and compressor speed 20-80 Hz, and the ECS operating at generator temperature 90 °C and condensing temperature 37 °C, the corresponding condensing temperature of the heat pump in the SACH is 24.5-42 °C, cooling capacity 1.02-2.44 kW, input power 0.20-0.98 kW, and cooling COPc 5.11-2.50. This indicates that the use of ECS in SACH can effectively reduce the condensing temperature of the heat pump by 12.6-7.3 °C and reduce the power consumption by 81.2-34.5%. The SACH can also supply heat from the heat pump. At ambient temperature from 5 °C to 35 °C, the heating COPh is in the range 2.0-3.3. © 2010 Elsevier Ltd. All rights reserved.

  6. Modeling and Experimental Validation of a Transient Direct Expansion Heat Pump

    Directory of Open Access Journals (Sweden)

    Clément Rousseau

    2017-06-01

    Full Text Available Geothermal heat pump technology is currently one of the most interesting technologies used to heat buildings. There are two designs used in the industry: geothermal heat pump using a secondary ground loop and Direct Expansion (DX ground source heat pump. The latter is less used, possibly because less research has been carried out for the design of this kind of heat pump. In this paper, a transient model using the Comsol Multiphysic of a DX ground heat pump is presented in heating mode with R22, and a comparison with experimental results is presented with a 24-hour test. It is shown that the model was adequately validated by our experiment with only a maximum difference of 15%. Following this validation, a parametric analysis was realised on the geometry of the borehole. This study concluded that to have the best heat extraction of the ground, the pipes shank spacing need to be important without increasing the borehole diameter. Keywords: Direct Expansion geothermal heat pump, Modeling, R22 Article History: Received January 16th 2017; Received in revised form May 28th 2017; Accepted June 6th 2017; Available online How to Cite This Article: Rousseau, C., Fannou, J.L.C., Lamarche, L. and Kajl, S. (2017 Modeling and Experimental Validation of a Transient Direct Expansion Heat Pump. International Journal of Renewable Energy Develeopment, 6(2, 145-155. https://doi.org/10.14710/ijred.6.2.145-155

  7. Experimental analysis of direct-expansion ground-coupled heat pump systems

    Science.gov (United States)

    Mei, V. C.; Baxter, V. D.

    1991-09-01

    Direct-expansion ground-coil-coupled (DXGC) heat pump systems have certain energy efficiency advantages over conventional ground-coupled heat pump (GCHP) systems. Principal among these advantages are that the secondary heat transfer fluid heat exchanger and circulating pump are eliminated. While the DXGC concept can produce higher efficiencies, it also produces more system design and environmental problems (e.g., compressor starting, oil return, possible ground pollution, and more refrigerant charging). Furthermore, general design guidelines for DXGC systems are not well documented. A two-pronged approach was adopted for this study: (1) a literature survey, and (2) a laboratory study of a DXGC heat pump system with R-22 as the refrigerant, for both heating and cooling mode tests done in parallel and series tube connections. The results of each task are described in this paper. A set of general design guidelines was derived from the test results and is also presented.

  8. Analysis of a Residential Heating System Utilizing a Solar Assisted Water-to-Air Heat Pump.

    Science.gov (United States)

    1979-07-01

    heat pump heating system were analyzed. A realistic residence and solar assisted water-to-air heat pump system were modeled for this northern climate using the transient simulation computer code TRNSYS developed by the University of Wisconsin. The system was studied over a one month winter period, December, using actual hourly weather data. The system was analyzed for both the cloudiest and clearest December weather recorded in the last 30 years. The collector area and storage tank capacity were varied and the effects on system performance were

  9. Theoretical energy and exergy analyses of solar assisted heat pump space heating system

    Directory of Open Access Journals (Sweden)

    Atmaca Ibrahim

    2014-01-01

    Full Text Available Due to use of alternative energy sources and energy efficient operation, heat pumps come into prominence in recent years. Especially in solar-assisted heat pumps, sizing the required system is difficult and arduous task in order to provide optimum working conditions. Therefore, in this study solar assisted indirect expanded heat pump space heating system is simulated and the results of the simulation are compared with available experimental data in the literature in order to present reliability of the model. Solar radiation values in the selected region are estimated with the simulation. The case study is applied and simulation results are given for Antalya, Turkey. Collector type and storage tank capacity effects on the consumed power of the compressor, COP of the heat pump and the overall system are estimated with the simulation, depending on the radiation data, collector surface area and the heating capacity of the space. Exergy analysis is also performed with the simulation and irreversibility, improvement potentials and exergy efficiencies of the heat pump and system components are estimated.

  10. Building Space Heating with a Solar-Assisted Heat Pump Using Roof-Integrated Solar Collectors

    Directory of Open Access Journals (Sweden)

    Zhiyong Yang

    2011-03-01

    Full Text Available A solar assisted heat pump (SAHP system was designed by using a roof-integrated solar collector as the evaporator, and then it was demonstrated to provide space heating for a villa in Tianjin, China. A building energy simulation tool was used to predict the space heating load and a three dimensional theoretical model was established to analyze the heat collection performance of the solar roof collector. A floor radiant heating unit was used to decrease the energy demand. The measurement results during the winter test period show that the system can provide a comfortable living space in winter, when the room temperature averaged 18.9 °C. The average COP of the heat pump system is 2.97 and with a maximum around 4.16.

  11. Steady-state testing of an advanced solar-assisted heat pump

    Energy Technology Data Exchange (ETDEWEB)

    Catan, M.A.

    1982-06-01

    A prototype water-to-air solar assisted heat pump (SAHP) has been tested under steady state conditions. The results of the tests indicate that the nominal goal for the hardware portion of the contract was achieved and surpassed. The tests show some areas of potential improvement, which are discussed.

  12. Solar assisted heat pump on air collectors: A simulation tool

    Energy Technology Data Exchange (ETDEWEB)

    Karagiorgas, Michalis; Galatis, Kostas; Tsagouri, Manolis [Department of Mechanical Engineering Educators, ASPETE, N. Iraklio, GR 14121 (Greece); Tsoutsos, Theocharis [Environmental Engineering Dept., Technical University of Crete, Technical University Campus, GR 73100, Chania (Greece); Botzios-Valaskakis, Aristotelis [Centre for Renewable Energy Sources (CRES), 19th km Marathon Ave., GR 19001, Pikermi (Greece)

    2010-01-15

    The heating system of the bioclimatic building of the Greek National Centre for Renewable Energy Sources (CRES) comprises two heating plants: the first one includes an air source heat pump, Solar Air Collectors (SACs) and a heat distribution system (comprising a fan coil unit network); the second one is, mainly, a geothermal heat pump unit to cover the ground floor thermal needs. The SAC configuration as well as the fraction of the building heating load covered by the heating plant are assessed in two operation modes; the direct (hot air from the collectors is supplied directly to the heated space) and the indirect mode (warm air from the SAC or its mixture with ambient air is not supplied directly to the heated space but indirectly into the evaporator of the air source heat pump). The technique of the indirect mode of heating aims at maximizing the efficiency of the SAC, saving electrical power consumed by the compressor of the heat pump, and therefore, at optimizing the coefficient of performance (COP) of the heat pump due to the increased intake of ambient thermal energy by means of the SAC. Results are given for three research objectives: assessment of the heat pump efficiency whether in direct or indirect heating mode; Assessment of the overall heating plant efficiency on a daily or hourly basis; Assessment of the credibility of the suggested simulation model TSAGAIR by comparing its results with the TRNSYS ones. (author)

  13. Solar Assisted Ground Source Heat Pump Performance in Nearly Zero Energy Building in Baltic Countries

    Science.gov (United States)

    Januševičius, Karolis; Streckienė, Giedrė

    2013-12-01

    In near zero energy buildings (NZEB) built in Baltic countries, heat production systems meet the challenge of large share domestic hot water demand and high required heating capacity. Due to passive solar design, cooling demand in residential buildings also needs an assessment and solution. Heat pump systems are a widespread solution to reduce energy use. A combination of heat pump and solar thermal collectors helps to meet standard requirements and increases the share of renewable energy use in total energy balance of country. The presented paper describes a simulation study of solar assisted heat pump systems carried out in TRNSYS. The purpose of this simulation was to investigate how the performance of a solar assisted heat pump combination varies in near zero energy building. Results of three systems were compared to autonomous (independent) systems simulated performance. Different solar assisted heat pump design solutions with serial and parallel solar thermal collector connections to the heat pump loop were modelled and a passive cooling possibility was assessed. Simulations were performed for three Baltic countries: Lithuania, Latvia and Estonia.

  14. Review on advanced of solar assisted chemical heat pump dryer for agriculture produce

    Energy Technology Data Exchange (ETDEWEB)

    Fadhel, M.I. [Solar Energy Research Institute, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia); Faculty of Engineering and Technology, Multimedia University, Jalan Ayer Keroh Lama, 75450 Melaka (Malaysia); Sopian, K.; Daud, W.R.W.; Alghoul, M.A. [Solar Energy Research Institute, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia)

    2011-02-15

    Over the past three decades there has been nearly exponential growth in drying R and D on a global scale. Improving of the drying operation to save energy, improve product quality as well as reduce environmental effect remained as the main objectives of any development of drying system. A solar assisted chemical heat pump dryer is a new solar drying system, which have contributed to better cost-effectiveness and better quality dried products as well as saving energy. A solar collector is adapted to provide thermal energy in a reactor so a chemical reaction can take place. This reduces the dependency of the drying technology on fossil energy for heating. In this paper a review on advanced of solar assisted chemical heat pump dryer is presented (the system model and the results from experimental studies on the system performance are discussed). The review of heat pump dryers and solar assisted heat pump dryer is presented. Description of chemical heat pump types and the overview of chemical heat pump dryer are discussed. The combination of chemical heat pump and solar technology gives extra efficiency in utilizing energy. (author)

  15. Solar assisted heat pumps: a possible wave of the future

    Energy Technology Data Exchange (ETDEWEB)

    Smetana, F.O.

    1976-12-01

    With the higher costs of electric power and the widespread interest to use solar energy to reduce the national dependence on fossil fuels, heat pumps are examined to determine their suitability for use with solar energy systems.

  16. Solar assisted heat pumps: A possible wave of the future

    Science.gov (United States)

    Smetana, F. O.

    1976-01-01

    With the higher costs of electric power and the widespread interest to use solar energy to reduce the national dependence on fossil fuels, heat pumps are examined to determine their suitability for use with solar energy systems.

  17. Simulation of Hybrid Photovoltaic Solar Assisted Loop Heat Pipe/Heat Pump System

    Directory of Open Access Journals (Sweden)

    Nannan Dai

    2017-02-01

    Full Text Available A hybrid photovoltaic solar assisted loop heat pipe/heat pump (PV-SALHP/HP water heater system has been developed and numerically studied. The system is the combination of loop heat pipe (LHP mode and heat pump (HP mode, and the two modes can be run separately or compositely according to the weather conditions. The performances of independent heat pump (HP mode and hybrid loop heat pipe/heat pump (LHP/HP mode were simulated and compared. Simulation results showed that on typical sunny days in spring or autumn, using LHP/HP mode could save 40.6% power consumption than HP mode. In addition, the optimal switchover from LHP mode to HP mode was analyzed in different weather conditions for energy saving and the all-year round operating performances of the system were also simulated. The simulation results showed that hybrid LHP/HP mode should be utilized to save electricity on sunny days from March to November and the system can rely on LHP mode alone without any power consumption in July and August. When solar radiation and ambient temperature are low in winter, HP mode should be used

  18. Control System for Solar-Assisted Heat Pump System.

    Science.gov (United States)

    heat pump , a water-to-air heat exchanger, a domestic water heater, and a cooling tower. The preferred embodiment of the controller of the present invention includes a first temperature sensing means for sensing the temperature of the collector fluid at the outlet of the solar collector system, a second temperature sensing means for sensing the temperature of the storage fluid at the thermal storage system, and a third temperature sensing means for sensing the temperature of the inlet water to the domestic water heater. The controller compares the temperature of the thermal

  19. Computer simulation of ground coupled storage in a series solar assisted heat pump system

    Energy Technology Data Exchange (ETDEWEB)

    Andrews, John W.; Metz, Philip D.

    1979-01-01

    A quantitative study of the effect of thermal coupling between the ground and the heat storage element of a series solar assisted heat pump system is presented. The transient simulation computer program TRNSYS is used to simulate the solar portion of this system. A program to simulate the thermal interaction of the storage element with the ground is incorporated into TRNSYS as a sub-routine. This program calculates heat flow through the ground in discrete steps over space and time. Boundary conditions are established. The ground coupled storage is driven by thermal inputs from the solar portion of the system and from the changing ambient and ground temperatures.

  20. Performance Study of Thermoelectric Solar-Assisted Heat Pump with Reflectors

    Science.gov (United States)

    Lertsatitthanakorn, C.; Soponronnarit, S.; Jamradloedluk, J.; Rungsiyopas, M.; Sarachitti, R.

    2014-06-01

    The simultaneous conversion of solar radiation into thermal and electrical energy in a thermoelectric (TE) solar-assisted heat pump is, for the purposes of this study, referred to as hybrid conversion. To capture more thermal and electrical energy, flat-plate reflectors have been mounted on a TE solar collector. To obtain higher solar radiation intensity on the TE solar collector, the position of the reflectors has been changed and the optimal position of the reflectors determined by both experimental measurements and numerical calculation so as to obtain maximal concentration of solar radiation intensity. The calculated values have been found to be in good agreement with measured ones. Improvements to the thermal energy and electrical power outputs of the system can be achieved by the use of the TE solar-assisted heat pump with reflectors. For the optimum position of the reflectors, the coefficient of performance (COP) of the system formed from a TE solar collector integrated with a heat pump (TESC-HP) was 5.60. The power output and conversion efficiency of the TE modules can reach 10.09 W and 2.40%, respectively, being improved by 34.5% and 18.2%, respectively, compared with the TESC-HP without reflectors.

  1. Solar-assisted heat supply in private homes. Solar unterstuetzte Waermeversorgung fuer private Haushalte

    Energy Technology Data Exchange (ETDEWEB)

    Hahne, E.; Fisch, N.

    1992-01-01

    Compared to decentralized systems, central heating in new residential areas proves to be rather more cost-effective and not more expensive. A volar support system will increase the price of heat but will still be cheaper than conventional single-application supply. In terms of a sparing use of raw materials and of CO[sub 2] emission reduction, the use of solar energy for heating and hot water is well worth thinking about although the resulting costs will be higher by a factor of 2 to 2.5 than the current cost of conventional energies. The government and local authorities should take a pioneering role in the propagation of solar-assisted systems today. (orig.)

  2. Solar-assisted heat pumps: impact of evaporator characteristics on performance

    Energy Technology Data Exchange (ETDEWEB)

    Catan, M.A.

    1982-03-01

    Five water-refrigerant heat exchangers were tested as part of a program of experimental studies of solar-assisted heat pump (SAHP) components and controls. The aim of this work is to establish ways of improving on the benchmark designs of two prototype SAHPs, one each built by Northrup Incorporated and Lennox Industries Incorporated under contract to the US Department of Energy (DOE). The performance of a water source heat pump, employing any of these evaporators, can be projected using these data, in conjunction with appropriate data pertaining to the rest of the heat pump. Thus, the impact of the evaporator's characteristics on the heat pump performance as a whole may be assessed. The necessary supplementary data may be obtained from compressor curves and condenser performance data, or from test data from a heat pump for which substitution of one of the evaporators considered in this report is contemplated. The steady state performance of the Northrup prototype SAHP employing each of the heat exchangers tested is projected using these test data. The projections of coefficient of performance (COP) versus entering water temperature performance are presented along with the original test data for comparison.

  3. Performance Analysis of Solar Assisted Fluidized Bed Dryer Integrated Biomass Furnace with and without Heat Pump for Drying of Paddy

    OpenAIRE

    M. Yahya

    2016-01-01

    The performances of a solar assisted fluidized bed dryer integrated biomass furnace (SA-FBDIBF) and a solar assisted heat pump fluidized bed dryer integrated biomass furnace (SAHP-FBDIBF) for drying of paddy have been evaluated, and also drying kinetics of paddy were determined. The SA-FBDIBF and the SAHP-FBDIBF were used to dry paddy from 11 kg with moisture content of 32.85% db to moisture content of 16.29% db (14% wb) under an air mass flow rate of 0.1037 kg/s within 29.73 minutes and 22.9...

  4. Performance analysis of solar-assisted chemical heat-pump dryer

    Energy Technology Data Exchange (ETDEWEB)

    Fadhel, M.I. [Solar Energy Research Institute, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia); Faculty of Engineering and Technology, Multimedia University, Jalan Ayer Keroh Lama, 75450, Melaka (Malaysia); Sopian, K.; Daud, W.R.W. [Solar Energy Research Institute, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia)

    2010-11-15

    A solar-assisted chemical heat-pump dryer has been designed, fabricated and tested. The performance of the system has been studied under the meteorological conditions of Malaysia. The system consists of four main components: solar collector (evacuated tubes type), storage tank, solid-gas chemical heat pump unit and dryer chamber. A solid-gas chemical heat pump unit consists of reactor, condenser and evaporator. The reaction used in this study (CaCl2-NH{sub 3}). A simulation has been developed, and the predicted results are compared with those obtained from experiments. The maximum efficiency for evacuated tubes solar collector of 80% has been predicted against the maximum experiment of 74%. The maximum values of solar fraction from the simulation and experiment are 0.795 and 0.713, respectively, whereas the coefficient of performance of chemical heat pump (COP{sup h}) maximum values 2.2 and 2 are obtained from simulation and experiments, respectively. The results show that any reduction of energy at condenser as a result of the decrease in solar radiation will decrease the coefficient of performance of chemical heat pump as well as decrease the efficiency of drying. (author)

  5. Study on the System Design of a Solar Assisted Ground Heat Pump System Using Dynamic Simulation

    Directory of Open Access Journals (Sweden)

    Min Gyung Yu

    2016-04-01

    Full Text Available Recently, the use of hybrid systems using multiple heat sources in buildings to ensure a stable energy supply and improve the system performance has gained attention. Among them, a heat pump system using both solar and ground heat was developed and various system configurations have been introduced. However, establishing a suitable design method for the solar-assisted ground heat pump (SAGHP system including a thermal storage tank is complicated and there are few quantitative studies on the detailed system configurations. Therefore, this study developed three SAGHP system design methods considering the design factors focused on the thermal storage tank. Using dynamic energy simulation code (TRNSYS 17, individual performance analysis models were developed and long-term quantitative analysis was carried out to suggest optimum design and operation methods. As a result, it was found that SYSTEM 2 which is a hybrid system with heat storage tank for only a solar system showed the highest average heat source temperature of 14.81 °C, which is about 11 °C higher than minimum temperature in SYSTEM 3. Furthermore, the best coefficient of performance (COP values of heat pump and system were 5.23 and 4.32 in SYSYEM 2, using high and stable solar heat from a thermal storage tank. Moreover, this paper considered five different geographical and climatic locations and the SAGHP system worked efficiently in having high solar radiation and cool climate zones and the system COP was 4.51 in the case of Winnipeg (Canada where the highest heating demand is required.

  6. Thermo-economic Optimization of Solar Assisted Heating and Cooling (SAHC System

    Directory of Open Access Journals (Sweden)

    A. Ghafoor

    2014-12-01

    Full Text Available The energy demand for cooling is continuously increasing due to growing thermal loads, changing architectural modes of building, and especially due to occupants indoor comfort requirements resulting higher electricity demand notably during peak load hours. This increasing electricity demand is resulting higher primary energy consumption and emission of green house gases (GHG due to electricity generation from fossil fuels. An exciting alternative to reduce the peak electricity consumption is the possible utilization of solar heat to run thermally driven cooling machines instead of vapor compression machines utilizing high amount of electricity. In order to widen the use of solar collectors, they should also be used to contribute for sanitary hot water production and space heating. Pakistan lying on solar belt has a huge potential to utilize solar thermal heat for heating and cooling requirement because cooling is dominant throughout the year and the enormous amount of radiation availability provides an opportunity to use it for solar thermal driven cooling systems. The sensitivity analysis of solar assisted heating and cooling system has been carried out under climatic conditions of Faisalabad (Pakistan and its economic feasibility has been calculated using maximization of NPV. Both storage size and collector area has been optimized using different economic boundary conditions. Results show that optimum area of collector lies between 0.26m2 to 0.36m2 of collector area per m2 of conditioned area for ieff values of 4.5% to 0.5%. The optimum area of collector increases by decreasing effective interest rate resulting higher solar fraction. The NPV was found to be negative for all ieff values which shows that some incentives/subsidies are needed to be provided to make the system cost beneficial. Results also show that solar fraction space heating varies between 87 and 100% during heating season and solar fraction cooling between 55 and 100% during

  7. Solar-assisted district heating systems: The Solarthermie 2000-programme; Solarunterstuetzte Nahwaermeversorgung: Programm Solarthermie-2000

    Energy Technology Data Exchange (ETDEWEB)

    Lottner, V. [Forschungszentrum Juelich GmbH (Germany). Projekttraeger Biologie, Energie, Umwelt (BEO)

    1998-12-31

    In Germany, utilisation of solar energy for thermal energy supply has a considerable technical and economic potential in terms of substitution of fossil fuels and reduction of CO{sub 2} emission. If appropriate technologies are used, solar-assisted district heat supply systems can be a cost-efficient concept for thermal utilisation of solar energy. The BMBF -programme `Solarthermie 2000` supports a number of pilot and demonstration plants in order to test and develop the most promising systems and storage facilities under real conditions. Long-term measuring programmes generate reliable data on thermal performance and cost of the plant concepts and create a solid basis for a technical and economic evaluation. (orig.) [Deutsch] Die Nutzung von Solarenergie fuer die Waermeversorgung bietet in Deutschland ein grosses technisches und wirtschaftliches Potential zur Substitution fossiler Energietraeger und Reduzierung der CO{sub 2} Emissionen in die Atmosphaere. Solarunterstuetzte Nahwaermesysteme stellen unter guenstigen technischen Bedingungen ein kostenguenstiges Konzept der thermischen Nutzung der Solarenergie dar. In dem BMBF-Programm Solarthermie-2000 werden Pilot- und Demonstrationsanlagen gefoerdert, so dass die aussichtsreichsten System- und Speicherkonzepte in der Praxis erprobt und gezielt weiterentwickelt werden koennen. Mit Langzeit-Messprogrammen werden belastbare Werte der thermischen Leistung und Kosten der Anlagenkonzepte ermittelt und eine zuverlaessige Grundlage fuer die technisch-wirtschaftliche Bewertung geschaffen. (orig.)

  8. System performance and economic analysis of solar-assisted cooling/heating system

    KAUST Repository

    Huang, B.J.

    2011-11-01

    The long-term system simulation and economic analysis of solar-assisted cooling/heating system (SACH-2) was carried out in order to find an economical design. The solar heat driven ejector cooling system (ECS) is used to provide part of the cooling load to reduce the energy consumption of the air conditioner installed as the base-load cooler. A standard SACH-2 system for cooling load 3.5. kW (1. RT) and daily cooling time 10 h is used for case study. The cooling performance is assumed only in summer seasons from May to October. In winter season from November to April, only heat is supplied. Two installation locations (Taipei and Tainan) were examined.It was found from the cooling performance simulation that in order to save 50% energy of the air conditioner, the required solar collector area is 40m2 in Taipei and 31m2 in Tainan, for COPj=0.2. If the solar collector area is designed as 20m2, the solar ejector cooling system will supply about 17-26% cooling load in Taipei in summer season and about 21-27% cooling load in Tainan. Simulation for long-term performance including cooling in summer (May-October) and hot water supply in winter (November-April) was carried out to determine the monthly-average energy savings. The corresponding daily hot water supply (with 40°C temperature rise of water) for 20m2 solar collector area is 616-858L/day in Tainan and 304-533L/day in Taipei.The economic analysis shows that the payback time of SACH-2 decreases with increasing cooling capacity. The payback time is 4.8. years in Tainan and 6.2. years in Taipei when the cooling capacity >10. RT. If the ECS is treated as an additional device used as a protective equipment to avoid overheating of solar collectors and to convert the excess solar heat in summer into cooling to reduce the energy consumption of air conditioner, the payback time is less than 3 years for cooling capacity larger than 3. RT. © 2011 Elsevier Ltd.

  9. Performance analysis of a direct expansion air dehumidification system combined with membrane-based total heat recovery

    Energy Technology Data Exchange (ETDEWEB)

    Liang, Cai-Hang; Zhang, Li-Zhi; Pei, Li-Xia [Key Laboratory of Enhanced Heat Transfer and Energy Conservation of Education Ministry, School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou 510640 (China)

    2010-09-15

    A direct expansion (DX) air dehumidification system is an efficient way to supply fresh and dry air to a built environment. It plays a key role in preventing the spread of respiratory disease like Swine flu (H1N1). To improve the efficiency of a conventional DX system in hot and humid regions, a new system of DX in combination with a membrane-based total heat exchanger is proposed. Air is supplied with dew points. A detailed mathematical modeling is performed. A cell-by-cell simulation technique is used to simulate its performances. A real prototype is built in our laboratory in South China University of Technology to validate the model. The effects of inlet air humidity and temperature, evaporator and condenser sizes on the system performance are investigated. The results indicate that the model can predict the system accurately. Compared to a conventional DX system, the air dehumidification rate (ADR) of the novel system is 0.5 times higher, and the coefficient of performance (COP) is 1 times higher. Furthermore, the system performs well even under harsh hot and humid weather conditions. (author)

  10. Analysis of a Hybrid PV/Thermal Solar-Assisted Heat Pump System for Sports Center Water Heating Application

    Directory of Open Access Journals (Sweden)

    Y. Bai

    2012-01-01

    Full Text Available The application of solar energy provides an alternative way to replace the primary source of energy, especially for large-scale installations. Heat pump technology is also an effective means to reduce the consumption of fossil fuels. This paper presents a practical case study of combined hybrid PV/T solar assisted heat pump (SAHP system for sports center hot water production. The initial design procedure was first presented. The entire system was then modeled with the TRNSYS 16 computation environment and the energy performance was evaluated based on year round simulation results. The results show that the system COP can reach 4.1 under the subtropical climate of Hong Kong, and as compared to the conventional heating system, a high fractional factor of energy saving at 67% can be obtained. The energy performances of the same system under different climatic conditions, that include three other cities in France, were analyzed and compared. Economic implications were also considered in this study.

  11. Design and Performance Evaluation of a Solar Assisted Heat Pump Dryer Integrated with Biomass Furnace for Red Chilli

    OpenAIRE

    M. Yahya

    2016-01-01

    The performance of a solar assisted heat pump dryer integrated with biomass furnace has been designed and evaluated for drying red chillies, and drying kinetics of red chillies were evaluated. The red chillies were dried from 22 kg with moisture content of 4.26 db to moisture content of 0.08 db which needed 11 hours, with the average drying chamber temperature, drying chamber relative humidity, and an air mass flow rate of 70.5°C, 10.1%, and 0.124 kg/s, respectively, while the open sun drying...

  12. Experimental study of a novel photovoltaic solar-assisted heat pump/loop heat-pipe (PV-SAHP/LHP) system

    Science.gov (United States)

    Zhang, Tao; Pei, Gang; Zhu, Qunzhi; Ji, Jie

    2017-01-01

    A prototype of a photovoltaic solar-assisted heat-pump/loop heat-pipe system (PV-SAHP/LHP) was constructed in this paper. The system was a combination of photovoltaic solar-assisted heat pump system (PV-SAHP) and loop heat pipe photovoltaic/thermal (LHP-PV/T) system. The combined system can carry out with two modes but using the same working fluid, and the two modes can switch operation freely. R600a was employed as the working fluid, and system performance under different working mode was presented in this paper. The results show that the day average photothermal efficiency & photovoltaic efficiency can reach to 43.6% & 11.3% under LHP-PV/T working mode compared with that of 57.5% & 12.1% under PV-SAHP working mode: Besides that, a day average COP of 3.66 was obtained under PV-SAHP working mode.

  13. 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.

  14. Design and Performance Evaluation of a Solar Assisted Heat Pump Dryer Integrated with Biomass Furnace for Red Chilli

    Directory of Open Access Journals (Sweden)

    M. Yahya

    2016-01-01

    Full Text Available The performance of a solar assisted heat pump dryer integrated with biomass furnace has been designed and evaluated for drying red chillies, and drying kinetics of red chillies were evaluated. The red chillies were dried from 22 kg with moisture content of 4.26 db to moisture content of 0.08 db which needed 11 hours, with the average drying chamber temperature, drying chamber relative humidity, and an air mass flow rate of 70.5°C, 10.1%, and 0.124 kg/s, respectively, while the open sun drying needed 62 hours. Compared to open sun drying, this dryer yielded 82% saving in drying time. The drying rate, the specific moisture extraction rate, and thermal efficiency of the dryer were estimated in average to be about 1.57 kg/h, 0.14 kg/kWh, and 9.03%, respectively. Three mathematical models, the Newton, Henderson-Pabis, and Page models, were fitted to the experimental data on red chillies dried by solar assisted heat pump dryer integrated with biomass furnace and open sun drying. The performance of these models was evaluated by comparing the coefficient of determination (R2, mean bias error (MBE, and root mean-square error (RMSE. The Page model gave the best results for representing drying kinetics of red chillies.

  15. Results of heating mode performance tests of a solar-assisted heat pump. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Jones, C.B.; Smetana, F.O.

    1979-04-01

    The performance of a heat pump, utilizing 8.16 square meters of low-cost solar collectors as the evaporator in a Freon-114 refrigeration cycle, was determined under actual insolation conditions during the summer and fall of 1976. C.O.P.'s (coefficient of performance) greater than 3 were obtained with condensing temperatures around 78 C and evaporating temperatures around 27 C. Ambient temperatures were about 3 C above evaporating temperatures. Similar performance levels were obtained at other insolation and temperature conditions. Experience with the system has identified some component and system changes which should increase the obtainable C.O.P. to about 4.0. These are described along with the system's design rationale. The accumulated data are presented as an appendix.

  16. Results of heating mode performance tests of a solar-assisted heat pump

    Science.gov (United States)

    Jones, C. B.; Smetana, F. O.

    1979-01-01

    The performance of a heat pump, utilizing 8.16 square meters of low-cost solar collectors as the evaporator in a Freon-114 refrigeration cycle, was determined under actual insolation conditions during the summer and fall of 1976. C.O.P.'s (coefficient of performance) greater than 3 were obtained with condensing temperatures around 78 C and evaporating temperatures around 27 C. Ambient temperatures were about 3 C above evaporating temperatures. Similar performance levels were obtained at other insolation and temperature conditions. Experience with the system has identified some component and system changes which should increase the obtainable C.O.P. to about 4.0. These are described along with the system's design rationale. The accumulated data are presented as an appendix.

  17. Performance Analysis of Solar Assisted Fluidized Bed Dryer Integrated Biomass Furnace with and without Heat Pump for Drying of Paddy

    Directory of Open Access Journals (Sweden)

    M. Yahya

    2016-01-01

    Full Text Available The performances of a solar assisted fluidized bed dryer integrated biomass furnace (SA-FBDIBF and a solar assisted heat pump fluidized bed dryer integrated biomass furnace (SAHP-FBDIBF for drying of paddy have been evaluated, and also drying kinetics of paddy were determined. The SA-FBDIBF and the SAHP-FBDIBF were used to dry paddy from 11 kg with moisture content of 32.85% db to moisture content of 16.29% db (14% wb under an air mass flow rate of 0.1037 kg/s within 29.73 minutes and 22.95 minutes, with average temperatures and relative humidities of 80.3°C and 80.9°C and 12.28% and 8.14%, respectively. The average drying rate, specific energy consumption, and specific moisture extraction rate were 0.043 kg/minute and 0.050 kg/minute, 5.454 kWh/kg and 4.763 kWh/kg, and 0.204 kg/kWh and 0.241 kg/kWh for SA-FBDIBF and SAHP-FBDIBF, respectively. In SA-FBDIBF and SAHP-FBDIBF, the dryer thermal efficiencies were average values of 12.28% and 15.44%; in addition, the pickup efficiencies were 33.55% and 43.84% on average, whereas the average solar and biomass fractions were 10.9% and 10.6% and 36.6% and 30.4% for SA-FBDIBF and SAHP-FBDIBF, respectively. The drying of paddy occurred in the falling rate period. The experimental dimensionless moisture content data were fitted to three mathematical models. Page’s model was found best to describe the drying behaviour of paddy.

  18. Assessment of solar-assisted gas-fired heat pump systems

    Science.gov (United States)

    Lansing, F. L.

    1981-01-01

    As a possible application for the Goldstone Energy Project, the performance of a 10 ton heat pump unit using a hybrid solar gas energy source was evaluated in an effort to optimize the solar collector size. The heat pump system is designed to provide all the cooling and/or heating requirements of a selected office building. The system performance is to be augmented in the heating mode by utilizing the waste heat from the power cycle. A simplified system analysis is described to assess and compute interrrelationships of the engine, heat pump, and solar and building performance parameters, and to optimize the solar concentrator/building area ratio for a minimum total system cost. In addition, four alternative heating cooling systems, commonly used for building comfort, are described; their costs are compared, and are found to be less competitive with the gas solar heat pump system at the projected solar equipment costs.

  19. Assessment of solar-assisted gas-fired heat pump systems

    Science.gov (United States)

    Lansing, F. L.

    1981-01-01

    As a possible application for the Goldstone Energy Project, the performance of a 10 ton heat pump unit using a hybrid solar gas energy source was evaluated in an effort to optimize the solar collector size. The heat pump system is designed to provide all the cooling and/or heating requirements of a selected office building. The system performance is to be augmented in the heating mode by utilizing the waste heat from the power cycle. A simplified system analysis is described to assess and compute interrrelationships of the engine, heat pump, and solar and building performance parameters, and to optimize the solar concentrator/building area ratio for a minimum total system cost. In addition, four alternative heating cooling systems, commonly used for building comfort, are described; their costs are compared, and are found to be less competitive with the gas solar heat pump system at the projected solar equipment costs.

  20. Solar Assisted Ground Source Heat Pump Performance in Nearly Zero Energy Building in Baltic Countries

    National Research Council Canada - National Science Library

    Karolis Januševičius; Giedrė Streckienė

    2013-01-01

    .... Heat pump systems are a widespread solution to reduce energy use. A combination of heat pump and solar thermal collectors helps to meet standard requirements and increases the share of renewable energy use in total energy balance of country...

  1. Solar assisted district heating system Hanover-Kronsberg; Solar unterstuetzte Nahwaermeversorgung Hannover-Kronsberg

    Energy Technology Data Exchange (ETDEWEB)

    Schlosser, M.; Heuer, M.; Bodmann, M.; Fisch, M.N. [Technische Univ. Braunschweig (DE). Inst. fuer Gebaeude- und Solartechnik (IGS)

    2006-07-01

    Since mid-2000, the Hanover-Kronsberg pilot plant has been providing heat for 106 apartments in multiple dwellings. A solar collector system and a seasonal hot-water heat store are integrated in the plant. Auxiliary heat is provided by the district heating system of the Kronsberg development. Collector yields in the first year were below expectations. Leaky connections between the collector field and supply mains resulted in standstills and loss of profit. In 2004, all connections were replaced successively, and the hydraulic system of the collector circuit was modified. The performance data of the last few years are the basis of this contribution, which focuses on the experience with the collector system since its commissioning. (orig.)

  2. Experimental analysis of a solar assisted absorption heat pump with earth seasonal storage

    Energy Technology Data Exchange (ETDEWEB)

    Lazzarin, R.M.

    A plant composed of an energy roof, a seasonal earth storage and an absorption heat pump has been tested. The purpose was to study the behaviour of the various components and their interaction. The surveys were carried out over a two year period. The following operations were considered: the charging of the earth storage by the energy roof and the working of an absorption heat pump connected either to the energy roof or to the earth storage.

  3. Solar-assisted central heating in Hamburg-Bramfeld; Solarunterstuetzte Nahwaermeversorgung Hamburg-Bramfeld

    Energy Technology Data Exchange (ETDEWEB)

    Ebel, M. [HGC Hamburg Gas Consult, Hamburg (Germany)

    1998-12-31

    About 38% of the energy consumed in Germany is used for space heating. Hot water demand of old buildings accounts for approximately 10% while buildings constructed according to modern insulation standards account for 15 - 20 %. Space heating has a considerable conservation potential, which plays an important role in terms of reducing carbon dioxide pollution. More and more new technologies for conventional thermal insulation as well as for the active use of solar energy are being developed and will soon be commercially available. (orig.) [Deutsch] In der Bundesrepublik Deutschland werden ca. 38% des Energieverbrauches fuer die Waermeversorgung von Gebaeuden eingesetzt. Auf den Warmwasserbedarf entfallen davon ca. 10% bei Altbauten und 15-20% bei Wohngebaeuden nach den heute gueltigen Waermeschutzbestimmungen. Damit liegt im Bereich der Waemreversorgung von Gebaeuden ein erhebliches Einsparpotential, welches innerhalb der Diskussion ueber die CO{sub 2}-Problematik eine immer groessere Bedeutung erlangt. Neben einer Verbesserung der konventionellen Waermedaemmung der Gebaeude werden zunehmend Techniken der aktiven Solarenergienutzung zur Einsatzreife entwickelt. (orig.)

  4. Solar-assisted district heating systems - the SOLARIS pilot plant at Chemnitz - Status report; Solar unterstuetzte Nahwaermeversorgung - Pilotanlage SOLARIS Chemnitz Statusbericht `98

    Energy Technology Data Exchange (ETDEWEB)

    Urbaneck, T.; Schirmer, U. [Technische Univ. Chemnitz (Germany). Projektgruppe Solarthermie 2000

    1998-12-31

    The solar-assisted district heating in the Technology and Industrial Park SOLARIS is currently being built. The seasonal heat storage is a gravel-water tank with a volume of 8,000 cubic metre and has already been completed. The expectations have been met with respect to using a simple technology for the construction of seasonal storage and reducing costs. The initial operation is scheduled for summer 1998. Afterwards a two-year measuring programme will control and evaluate the function of the solar-assisted district heating system. (orig.) [Deutsch] Das solar unterstuetzte Nahwaermesystem im Chemnitzer Technologie- und Gewerbepark solaris befindet sich im Bau. Der saisonale Waermespeicher, ein 8000 m{sup 3} Kies-Wasser-Speicher ist fertiggestellt. Die Erwartungen in bezug auf eine einfache Technologie zum Bau von saisonalen Speichern und in bezug auf die Einhaltung des Kostenrahmens wurden erfuellt. Die Inbetriebnahme ist im Sommer 1998 geplant. Ein zweijaehriges Messprogramm soll nach Inbetriebnahme die Funktion des solar unterstuetzten Nahwaermesystems ueberwachen. (orig.)

  5. The underground heat storage for solar-assisted district heating in Neckarsulm. First measuring results; Der Erdsonden-Waermespeicher fuer die solarunterstuetzte Nahwaermeversorgung in Neckarsulm. Erste Messergebnisse

    Energy Technology Data Exchange (ETDEWEB)

    Seiwald, H.; Hahne, E. [Stuttgart Univ. (Germany). Inst. fuer Thermodynamik und Waermetechnik

    1998-12-31

    A solar-assisted district heating system with seasonal underground heat storage is currently under construction in Neckarsulm (Baden-Wurttemberg). In the new residential area approximately 1,300 flats are going to be built during the next years. The overall energy demand (hot water and space heating) is supposed to be covered by 50% with solar energy. During the first phase the project will be subsidised in the frame of the BMBF programme `Solarthermie 2000, Teilprogramm III`. A solar plant consisting of 2,700 square metres of collectors, a buffer tank (100 cubic metre) and an underground heat storage with a volume of approx. 20,000 cubic metres will be constructed by the end of 1998. It will be the first plant in Germany where thermal energy generated of solar energy is stored at high temperatures (up to 80 C) directly in the earth and utilised without a heat pump. (orig.) [Deutsch] In Neckarsulm (Baden-Wuerttemberg) befindet sich derzeit eine solar unterstuetzte Nahwaermeversorgung mit saisonalem Endsonden-Waermespeicher im Aufbau. Im Neubaugebiet Amorbach werden in den naechsten Jahren rund 1300 Wohneinheiten entstehen, deren Gesamtwaermebedarf (Warmwasser und Raumheizung) zu rund 50% mit Sonnenenergie gedeckt werden soll. In der ersten Phase wird das Projekt im Rahmen des BMBF-Programms `Solarthermie 2000, Teilprogramm III` gefoerdert. Bis Ende 1998 wird eine Solaranlage bestehend aus 2.700 m{sup 2} Kollektoren, einem Pufferspeicher (100 m{sup 3}) und einem Endsonden-Waermespeicher mit einem Volumen von ca. 20.000 m{sup 3} erstellt. Damit wird in Deutschland erstmalig eine Anlage realisiert, bei der solar erzeugte Waerme auf hohem Temperaturniveau (bis zu 80 C) direkt im Erdreich gespeichert und ohne Waermepumpe genutzt werden soll. (orig.)

  6. Solar-assisted biomass-district heating: projects in Austria and operational data; Solarunterstuetzte Biomasse-Fernwaermeversorgung: Projekte in Oesterreich und Betriebsdaten

    Energy Technology Data Exchange (ETDEWEB)

    Faninger, G. [Institut fuer Interdisziplinaere Forschung und Fortbildung der Universitaeten Klagenfurt, Innsbruck und Wien (IFF), Klagenfurt (Austria)

    1998-12-31

    In recent years small-volume biomass district heating systems (district heat grids) have attracted increasing interest in Austria. By the end of 1997 some 359 biomass-district heating systems with an overall capacity of approximately 483 MW were in operation. If a biomass-district heating plant and a solar plant are combined the solar plant can supply most of the heat required outside the heating season. At present Austria runs 12 solar-assisted biomass-district heating grids with collector areas between 225 square metres and 1,250 square metres. In order to run these biomass-district heating systems in an economically and technically efficient way it is necessary to assure high quality in terms of planning, construction and operation. A list of criteria is set up on the basis of first operational data in order to evaluate energy efficiency and economic performance. These criteria should be applied in order to ensure that energy, environment and economy are equally considered in the planning and construction of solar-assisted biomass-district heating plants. They should also be helpful for the approval procedures of projects. (orig.) [Deutsch] Kleinraeumige Biomasse-Fernwaermeanlagen (Nahwaermenetze) fanden in den letzten Jahren zunehmendes Interesse in Oesterreich. So waren Ende 1997 insgesamt 359 Biomasse-Fernwaermeanlagen mit einer installierten Gesamtleistung von etwa 483 MW in Betrieb. Die Kombination einer Biomasse-Fernwaermeanlage mit einer Solaranlage bringt den Vorteil, dass die Waermebereitstellung ausserhalb der Heizsaison zu einem hohen Anteil ueber die Solaranlage vorgenommen werden kann. Derzeit werden in Oesterreich 12 solarunterstuetzte Biomasse-Nahwaermenetze mit Kollektorflaechen von 225 m{sup 2} bis 1.250 m{sup 2} betrieben. Um einen moeglichst effizienten und damit auch wirtschaftlichen Betrieb von solarunterstuetzten Biomasse-Fernwaermeanlagen zu gewaehrleisten, werden hohe Anforderungen an Planung, Ausfuehrung und Betrieb gestellt. Auf der

  7. Solar-assisted district heating systems, state-of-the-art and economic efficiency; Solarunterstuetzte Nahwaermeversorgung Stand der Technik und Wirtschaftlichkeit

    Energy Technology Data Exchange (ETDEWEB)

    Fisch, M.N. [Technische Univ. Braunschweig (Germany). Inst. fuer Gebaeude- und Solartechnik; Kuebler, R. [Steinbeis Transferzentrum Energie-, Gebaeude- und Solartechnik (STZ-IGS), Stuttgart (Germany)

    1998-12-31

    After the successful testing of smaller solar-assisted district heat supply projects in the first half of the Nineties in Germany (e.g. Ravensburg, Koengen, Neckarsulm, Schwaebisch-Gmuend), the first large-scale plants with long term heat storage started to operate in Hamburg and Friedrichshafen. Thus a target has been reached that had seemed to be an illusion for a long time - the utilisation of solar energy generated in the summer for building heating in wintertime. In Hamburg (collector area = 3,000 square metres) and Friedrichshafen (collector area = 5,600 square metres when finished) buried hot-water storage tanks with a volume of 4,500 cubic metres and 12,000 cubic metres were built; bore-hole heat storage is being tested in a third demonstration project in Neckarsulm. The first part of this plant (collector area = 2,700 square metres, storage capacity approximately 20,000 cubic metres) was put in operation in October 1997. A fourth solar-assisted district heating system with a gravel/water heat storage (volume approximately 8,000 cubic metres) is currently under construction in Chemnitz and supposed to be completed in the second half of 1998. (orig.) [Deutsch] Nach der erfolgreichen Erprobung von kleineren solarunterstuetzten Nahwaermeprojekten in der ersten Haelfte der neunziger Jahre in Deutschland (z.B. Ravensburg, Koengen, Neckarsulm, Schwaebisch-Gmuend) gingen Ende 1996 in Hamburg und Friedrichshafen die ersten solaren Grossanlagen mit Langzeit-Waermespeicher in Betrieb. Damit wurde ein Ziel erreicht, das ueber viele Jahre hinweg utopisch erschienen war - mit der Sonnenenergie aus dem Sommer im Winter die Gebaeude zu beheizen. Waehrend in Hamburg (Kollektorflaeche 3.000 m{sup 2}) und in Friedrichshafen (5.600 m{sup 2} im Endausbau) eingegrabene Heisswasser-Waermespeicher mit einem Volumen von 4.500 m{sup 3} bzw. 12.000 m{sup 3} realisiert wurden, wird in einem dritten Demonstrationsprojekt in Neckarsulm ein Erdsonden-Waermespeicher erprobt. Die erste

  8. Optimization on solar-assisted heat pump system based on TRNSYS%基于TRNSYS的太阳能水源热泵系统优化研究

    Institute of Scientific and Technical Information of China (English)

    曲世琳; 王东旭; 董家男; 彭莉

    2015-01-01

    为提高太阳能水源热泵耦合系统性能,该文从设计及运行两方面对其进行优化研究.在建立太阳能水源热泵耦合系统应用模型的基础上,用瞬时系统模拟程序( Transient system simulation program,TRNSYS)软件搭建系统计算模型,以系统的设计参数如:太阳能集热器面积、储热水箱体积及集热器倾角等为变量,利用GENOPT软件对系统进行优化. 并以系统运行控制参数如:集热器供回水温差和供暖末端供回水温差为变量分析系统性能参数( Coefficient of performance,COP) ,分析系统节能潜力. 该文以北京某别墅为研究对象进行优化,结果表明系统COP升高、性能得到改善. 研究结果为太阳能热泵系统优化提供了一定的理论依据.%This paper optimizes a solar-assisted heat pump system on design and operation in order to improve its performance. We build a system model using transient system simulation program (TRNSYS),taking solar collector area,storage tank capacity and collector tilt as variables,and then optimize the design using GENOPT software. Meanwhile, we analyze the coefficient of performance ( COP) and energy-saving potential of the system by taking temperature difference between supply and return water of heat collectors and that of heating terminal equipments as variables. The object of this study is a villa in Beijing. The study results show that the COP is increased and the performance is im-proved,which provide theoretical foundation for optimization on the solar-assisted heat pump system.

  9. Solar assisted absorption or motor driven heat pump with earth seasonal storage. Final report. Pt. 1 and 2

    Energy Technology Data Exchange (ETDEWEB)

    Lazzarin, R.M.

    1987-01-01

    A plant composed of an energy roof, a seasonal earth storage and an absorption heat pump has been experimented. The purpose was to study the behaviour of the various components and their interaction. The surveys went on during two years. The following operations are considered: The charging of the earth storage by the energy roof and the working of an absorption heat pump connected either to the energy roof or to the earth storage.

  10. COMPREHENSIVE EVALUATION OF SOLAR ASSISTED GROUND SOURCE HEAT HUMP%太阳能+地源热泵联合循环项目综合评标

    Institute of Scientific and Technical Information of China (English)

    孙洲阳; 陈武

    2013-01-01

    Selection of heating-ventilation-air conditioning (HVAC) cooling and heating source is a multiattribute problem,involving lots of unmeasurable factors.The fuzzy comprehensive evaluation method transfers qualitative indexes into quantitative indexes utilizing fuzzy membership,and solves the problem very well.Evaluation cases include:(1) solar assisted ground source heat hump central air-conditioning; (2) lithium bromide direct-fired absorption chiller; (3) chiller and fuel boiler; (4) chiller and gas boiler; (5) chiller and electrical boiler.The evaluate results show that the case (1) is the best.%提出一种基于模糊数学的综合评价方法——模糊综合评价法.该方法利用模糊隶属度理论把定性指标合理定量化,把定性评价转化为定量评价.评估方案包括:①太阳能+地源热泵联合循环;②溴化锂吸收式直燃机组;③冷水机组+燃油热水锅炉;④冷水机组+燃气热水锅炉;⑤冷水机组+电锅炉.事实证明,利用模糊综合评价方法得出的最终结果与实际评标结果吻合较好,具有良好的实用价值.

  11. Solar assisted absorption or motor driven heat pump with earth seasonal storage: Part 2, Tables and figures: Final report

    Energy Technology Data Exchange (ETDEWEB)

    Lazzarin, R.M.

    1986-01-01

    A plant composed of an energy roof, a seasonal earth storage and an absorption heat pump has been tested. The purpose was to study the behavior of the various components and their interaction. The surveys went on during two years. The following operations are considered: the charging of the earth storage by the energy roof and the working of an absorption heat pump connected either to the energy roof or to the earth storage. This volume contains all the figures and tables for the report. 77 figs., 24 tabs.

  12. The solar-assisted district heating concept in Stuttgart-Burgholzhof; Das solarunterstuetzte Nahwaermekonzept Stuttgart-Burgholzhof

    Energy Technology Data Exchange (ETDEWEB)

    Grosshans, D. [Neckarwerke Stuttgart AG (Germany)

    1998-12-31

    The housing area Burgholzhof is located on a hill above the valley of Stuttgart in the city borough of Canstatt. The building area has a size of 13.4 hectare and will contain 1,360 flats with a total heated area of 86,000 square metres that can house 2,800 people. Heat will be supplied by a heating power station, a plant for thermal use of solar energy and a heat distribution system built by Neckarwerke Stuttgart (Stuttgart utility company). The Neckarwerke Stuttgart paid the construction costs of the plant for thermal utilisation of solar energy. They will not be included in the energy price charged to the consumer. (orig.) [Deutsch] Das Wohngebiet `Burgholzhof` liegt auf einer Anhoehe ueber dem Talkessel der Landeshauptstadt Stuttgart im Stadtteil Bad-Cannstatt. Die Bebauungsflaeche betraegt nach einer im Jahr 1997 durchgefuehrten Arrondierung 13,4 ha. Im Endausbau werden etwa 1360 Wohneinheiten mit einer beheizten Gesamtflaeche von etwa 86 000 m{sup 2} entstanden sein. Somit koennen etwa 2800 Buergerinnen und Buerger in diesem neuen Stadtteil wohnen. Zur Waermeversorgung wurde ein Heizwerk, eine Anlage zur thermischen Nutzung der Sonnenenergie und ein Waermeverteilsystem von den NWS erstellt. Die Kosten fuer den Bau der Anlage zur thermischen Nutzung der Sonnenenergie wurden von den NWS uebernommen. Sie sind somit kein Bestandteil des an die Nutzer zu verrechnenden Waermepreises. (orig.)

  13. 多功能太阳能辅助空气源热泵系统研究%Multifunctional Solar Assisted Air Source Heat Pump System

    Institute of Scientific and Technical Information of China (English)

    李洪

    2013-01-01

      研究设计了一种多功能太阳能辅助空气源热泵系统,可实现一机多用,根据用户的不同需求,可在多种模式下运行.该系统将太阳能热利用技术与热泵技术相结合,克服了太阳能的不稳定性,同时有望提高太阳能热利用效率及系统综合运行性能.通过对该系统在某宾馆建筑中的应用研究发现:该系统全年月平均太阳能利用系数可达61.8%,综合运行性能比传统空调及热水供应系统有所提高,尤其在制冷季;与传统组合系统相比,系统运行能耗明显降低,全年平均节能接近50%.%A novel multifunctional solar assisted air source heat pump system is presented. The studied system can work in different op-erating modes depending on different requirement of customers. The combination of solar thermal application with heat pump technology has great potential in improving the comprehensive operating performance. A case study employing the system in a hotel is analyzed. The investi-gation results show that the solar fraction of the system can averagely reach 61.8%. Compared with conventional system, the comprehensive performance is obviously promoted, especially in cooling season. Energy consumption of the studied system is also significantly reduced and nearly 50%can be saved.

  14. A new photovoltaic solar-assisted loop heat pipe/heat-pump system%新型光伏-太阳能环形热管/热泵复合系统

    Institute of Scientific and Technical Information of China (English)

    张龙灿; 裴刚; 张涛; 季杰

    2014-01-01

    The photovoltaic solar assisted loop heat pipe system/heat-pump (PV-SALHP/HP) is the combination of solar assisted loop heat pipe system (SALHP) and solar assisted heat pipe (SAHP). A photovoltaic/thermal (PVT) evaporator and condenser could be shared by two circling modes, and so is the working medium. The loop heat pipe mode will be utilized when solar radiation is strong and the temperature of working medium in PVT evaporator is higher than that in condenser. Correspondingly, the heat pump mode will be started when solar radiation is weak or the temperature difference of working medium in PVT evaporator and condenser cannot satisfy the condition of loop heat pipe mode. The loop heat pipe mode is passive and the heat pump mode is active, which means that the loop heat pipe mode does not consume work and the heat pump mode does. Therefore, the transformable mode of system could heavily reduce power consumption, raise the utilization ratio of solar energy, and promote energy saving. A PV-SAHP/LHP test rig is built. The instantaneous and daily performance of the loop heat pipe mode and heat pump mode is studied.%光伏-太阳能环形热管/热泵复合系统将太阳能环形热管循环模式和太阳能热泵循环模式有机结合,两者采用相同的工质,共用一个PVT蒸发器和冷凝器。当太阳辐照强度较强,工质在PVT蒸发器中的温度高于冷凝器中的温度时,可以利用环形热管模式制热;当太阳辐照强度较弱或工质在PVT蒸发器中与冷凝器中的温差无法满足环形热管模式运行时,可以利用热泵模式制热。两种模式既能够独立运行,又可以互相切换,确保热能的稳定供应,同时能够明显降低系统耗电量。搭建了光伏-太阳能环形热管/热泵复合系统实验平台,对复合系统在环形热管模式和热泵模式独立运行时的瞬时性能和全天性能进行了实验研究。

  15. 北方地区应用太阳能辅助土壤源热泵效能分析%Efficiency Analysis of Utilizing Solar-assisted Ground Source Heat Pump in the Northern China

    Institute of Scientific and Technical Information of China (English)

    赵金秀

    2015-01-01

    针对北方寒冷地区气候特点,指出了太阳能辅助土壤源热泵系统相对于单独的土壤源热泵或单独的太阳能应用的技术特点。对北方寒冷地区某学校综合楼建筑进行了太阳能辅助土壤源热泵系统设计;并针对该建筑采用太阳能辅助土壤源热泵系统、采用单独的土壤源热泵系统或采用传统采暖空调系统,从三者经济效益、社会效益、环境效益等方面进行了比较,从而体现了太阳能辅助土壤源热泵系统相对于单独的土壤源热泵系统或传统采暖空调系统的高效、经济、节能、环保等优异性。%For the cold climate characteristics of the Northern China, the paper introduces the technical characteristics of solar-assisted ground source heat pump system relative to the separate ground source heat pump system or the separate solar energy application. For a complex building of a university in the cold northern area, the solar -assisted ground source heat pump system is designed, and economic benefits, social benefits, environmental benefits and other aspects about using the solar-assisted ground source heat pump system or using the ground source heat pump system alone or using the traditional air conditioning system are compared, thus reflects the excellent efficiency, cost-saving and energy -saving characteristics, and environmental protection about the solar assisted ground source heat pump system.

  16. THE TRANSIENT ANALYSIS OF A HOUSEHOLD BIOGAS DIGESTER WITH SOLAR ASSISTED HEATING SYSTEM%太阳能辅助加热户用沼气系统的瞬时计算分析

    Institute of Scientific and Technical Information of China (English)

    陈志光; 秦朝葵; 李振群; 戴万能

    2011-01-01

    设计了太阳能辅助加热户用沼气池系统.太阳集热器集热通过螺旋管换热器加热沼液.为了评价系统的加热效果,对系统进行优化设计,建立了系统数学模型,对系统冬季运行情况进行计算分析.结果表明,太阳能辅助加热户用沼气系统能有效提高沼气池内温度.%In order to maintain a certain degree of temperature for rural household biogas digester in winter especially in north China, a solar assisted heating system was designed. In the system the biogas digester was heated by hot water from the solar collector through a spiral heat exchanger. A mathematical model was established and the operation of the system was simulated to evaluate the effect of the system. The results show that the solar-assisted heating system can effectively increase the temperature of the household biogas digester.

  17. Evaluation of the performance in the solar assisted heat pump system; Taiyonetsu riyo heat pump system no seino hyoka ni tsuite

    Energy Technology Data Exchange (ETDEWEB)

    Saito, Y. [Osaka Institute of Technology, Osaka (Japan)

    1996-10-27

    Performance of a solar heating system with a hydrothermal source heat pump was evaluated and compared with that of a direct solar heating system. The sun-dependency rates ({Sigma}D and {Sigma}H)of the direct system and heat pump (HP)-provided system were expressed as a function of the rate ({alpha}) of the auxiliary heat against the collected heat and as a function of the performance coefficient and {alpha}, respectively. When the sun-dependency rates are compared, it is found that the HP-provided system is the more advantageous when {Sigma}H/{Sigma}D>1. The relationship between the {alpha}`s of the two systems was clarified and computation was performed to compare the sun-dependency rates on condition that the two are equal in the heat collecting area. Although the sun-dependence rate cannot be elevated to 100% in the HP-provided system, it achieves a sun-dependency rate higher than that of the direct system even when the heat collecting area is small. In cases where the building is economically limited, for instance, with respect to the area for solar collector installation, it is advantageous to employ the HP-provided system. 5 figs., 1 tab.

  18. Drying Experimental Analysis Based on Series-parallel Solar-assisted Heat Pump%混联式太阳能热泵干燥装置物料试验分析

    Institute of Scientific and Technical Information of China (English)

    吴鹏辉; 周来发; 邱瑜

    2013-01-01

    提出了串联和并联相结合的混联式太阳能热泵干燥系统,其中太阳能以直接、间接两种方式介入于干燥过程,设计制造了一套太阳能热泵干燥装置.在此基础上,以典型干燥物料鱼和萝卜进行试验,并就干燥性能、实际结果作了较具体、较详尽的分析.%Presents a series and parallel combination of hybrid solar-assisted heat pump drying system,the solar energy would be intervened to the drying process with direct or indirect way, and a set of small solar-assisted heat pump device was designed and manufactured. Then,two typical drying tests of fish and radish were done based on that drying apparatus. Finally, such specific and detailed analysis for the experiment results were conducted,the drying performance reached as well.

  19. Numerical Simulation of Unsteady Heat Transfer in Solar-assisted Heating Household Biogas Digester%户用太阳能辅助加热沼气池动态传热仿真

    Institute of Scientific and Technical Information of China (English)

    郭甲生; 秦朝葵; 魏晓峰; 唐继旭

    2011-01-01

    针对态变温差条件下螺旋管换热器传热系数计算复杂,而螺旋管换热器传热系数是户用太阳能辅助加热沼气池系统设计中的重要参数.为确定沼气池内加热盘管的传热系数及合理的搅拌叶轮旋转速度,采用全三维Navier-Stokes方程和多重参考系法(MRF),根据标准k-ε湍流模型及相应的计算网络及边界条件,对沼气池内传热及流动进行三维非定常数值仿真,分析系统的传热系数,随着旋转叶轮转速提高,螺旋加热盘管传热系数也随之增加,但旋转叶轮所需电机功率也将随之增大.通过数值仿真,可以大大缩短系统的研制和改进设计周期,结果与现场实测传热系数有较好的吻合.证明提高了沼气池内螺旋盘管的加热效果,并为系统设计提供参考依据.%The heat transfer coefficient of spiral tube exchanger in unsteady condition is hard to obtain, while the heat transfer coefficient of spiral tube exchanger is of great importance in design of solar-assisted heating household biogas digester system.The development and design cycle and cost of solar-assisted heating household biogas digester system can be cut down greatly with the support of numerical simulation.In this paper, studies were carried out on the three-dimensional unsteady numerical simulation of heating process in biogas digesters by using computational fluid dynamics (CFD), the multi-reference frame (MRF) and standard k-ε turbulent model were used in the simulation.The simulation result indicates that heating coil heat transfer coefficient can enhance significantly with the use of stirring device in biogas digesters.With the increase of rotating impeller speed, heating coil heat transfer coefficient increases, however, the rotating impeller motor power requirements also increase.The heating coil heat transfer coefficient simulation result has a good match with the field test result.The results are of importance to the design of SHHBDS.

  20. 严寒地区太阳能热泵供暖系统设计与运行实测%Design and Operation Measurement of Solar Assisted Heat Pump System for Heating in Severe Cold Zone

    Institute of Scientific and Technical Information of China (English)

    刘其伟; 姜益强; 于易平

    2013-01-01

    In this paper, a solar assisted heat pump system for heating in severe cold zone was proposed, and its principle, operational modes and control measures were introduced. This system had good adaptability under different operation conditions with several operational modes,the solar energy could be utilized to the greatest extent and the operational efficiency could be guaranteed. The operation measurement results of a practical engineering in Daqing indicated that the thermal efficiency of solar collector was 51% of the typical day in December. If employing standby heating in the night, the solar fraction would up to 70% of the typical day in November. In addition,the cost of per heating area was about 18 RMB,saving by 60%. To sum up,the system had good performance of energy conservation and economical efficiency.%本文提出了一种适合严寒地区供暖的太阳能热泵系统,介绍了系统的原理、运行模式及控制措施.多种运行模式使系统在不同工况下具有较好的适应性,可最大程度利用太阳能,保证热泵的运行效率.大庆某实际工程的运行数据表明:12月典型日集热器集热效率为51%;若采用夜晚值班供暖,11月典型日太阳能保证率可达70%.单位供暖面积供暖费用为18元左右,可节约60%,系统具有较好的节能性和经济性.

  1. Design of Control System of Parallel Solar Assisted Heat Pump Water Heater%并联式太阳能热泵热水器控制系统设计

    Institute of Scientific and Technical Information of China (English)

    张建成; 吴永明; 苗文凭

    2012-01-01

    阐述了并联式太阳热泵热水器是最易受推广使用的太阳能热泵热水器类型;针对23目前并联式太阳能热泵热水器存在的集成化控制问题,分析了并联式太阳热泵热水器控制系统的控制要求,采用水位、温差与时间相结合的控制方法,以ATmega48单片机为核心,研究了控制系统的工作原理、硬件结构及控制数据流程;系统能够根据天气、水温等不同情况自动选择太阳能机组或空气能热泵机组来制取热水,并且具有主要设备的故障自诊断功能、压缩机延时保护功能及智能化霜功能,提高了该热水器的稳定性和低温制热效率;测试结果表明:使用该集成系统后,系统平均能源利用率提高了约23%.%Among all the solar assisted heat pump water heater, the paralle type is the most easily promoted. According to the integrated problem that exists in the control of the parallel solar assisted heat pump water heater, on the basis of analyzing requirements of the control system of the parallel solar assisted heat pump water heater, the control method associating with water-level, difference in temperature and time is applied. The realization principle, hardware structure and controlling data flow of the control system are studied based on AT-mega48. The system can select automatically solar-energy or air-energy heat -pump to make hot water according to weather and water temperature. Combined with the functions of fault self -diagnosis for key facilities, delay protection for compressor and automatically defrosting, the control system can improve the stability and thermal efficiency of the water heater under the low temperature. The results show that 23%of the average energy efficiency have been improved by using the integrated control system.

  2. Solar-assisted Heat Pump Drying Technology and its Research Progress%太阳能辅助热泵干燥技术及其研究进展

    Institute of Scientific and Technical Information of China (English)

    贺飞; 唐兰; 黎清荐

    2016-01-01

    干燥物料需要消耗大量的能量。我国的干燥能耗占工业总能耗比例达到了12%。机械化程度低是我国干燥能耗大于发达国家的主要原因。将热泵技术应用于物料干燥节能效果明显,并且热泵干燥是一种温和的干燥方式,干燥产品品质好,干燥温度调节范围宽,干燥参数易于控制。相比于热泵干燥,太阳能干燥运行费用低,环境污染少,也得到了广泛的关注。把太阳能与热泵结合起来进行物料干燥相比原有单一热泵系统有较大改进和提高。论述了国内外太阳能辅助热泵干燥技术。%Drying material will use a lot of energy. The energy consumption of drying takes up 12%of the total energy consumption of industry in China. The greater drying consumption in our country than that in the developed countries is caused by the low degree of mechanization. The heat pump technology applied to the material drying can get an obvious energy saving effect, meanwhile, the heat pump drying is a moderate drying method with better drying product quality, wide adjusting range of drying temperature, and easier parameters control. Compared with the heat pump drying, the solar drying operation cost is lower with less environmental pollution which also received wide attention. Solar -assisted heat pump drying technology has greater improvement compared to the original single heat pump system. The solar-assisted heat pump drying both at home and abroad is expounded.

  3. Performance on Solar-Assisted Ground-Source Heat Pump System%太阳能-地源热泵串联复合式系统的性能研究

    Institute of Scientific and Technical Information of China (English)

    丁力勤

    2016-01-01

    对于总热负荷与总冷负荷不平衡的建筑,单独采用土壤源热泵系统供暖或供冷时,系统运行末期土壤温度发生很大的变化,降低了系统的运行性能。针对此类建筑,搭建太阳能-土壤源串联复合式热泵系统,从集热器单位面积流量、存储水箱体积的影响因素出发,研究供暖期热泵机组蒸发器侧进水温度、系统运行性能和能耗的变化情况,为常规土壤源热泵系统引起的土壤热平衡问题提出解决方案,为今后的实际工程设计及应用提供参考依据。%In the heating load dominated area of cold winter zone, the heat taken and released to the soil is unbalanced, when the ground source heat pump (GSHP) system is responsible for all air conditioning loads in most cases. Then it results that the soil temperature would change greatly, and the performance of the system would bring down. The paper builds the ground source heat pump system and the solar-assisted ground-source heat pump system, and then analyzes the different inlet water temperature of heat pump, the different performance and energy consumption according to different collector unit area and tank volume parameters. It is important to provide reference to build the integrated heat pump system and solution for the soil thermal balance.

  4. Solar assisted absorption or motor driven heat pump with earth seasonal storage: Part 1, Final report, 1 July 1982-30 June 1985

    Energy Technology Data Exchange (ETDEWEB)

    Lazzarin, R.M.

    1986-01-01

    A plant composed of an energy roof, a seasonal earth storage and an absorption heat pump has been tested. The purpose was to study the behavior of the various components and their interaction. The surveys went on during two years. The following operations are considered: the charging of the earth storage by the energy roof and the working of an absorption heat pump connected either to the energy roof or to the earth storage.

  5. An Analysis of Different Solar-Assisted Heating Systems and Their Effect on the Energy Performance of Multifamily Buildings—A Swedish Case

    Directory of Open Access Journals (Sweden)

    Richard Thygesen

    2017-01-01

    Full Text Available Today, the household sector in the European Union and in Sweden accounts for approximately 25% and 22% of the final energy demand, respectively, and the sector will continue to grow in the next decades. To limit the impact on the energy demand of buildings, the European Union has introduced the Energy Performance of Building Directive. In Sweden, a proposal for building regulations adapted to the Energy Performance of Buildings Directive has been released, but no decision on implementation of it has been made. In this article, a real building is simulated to evaluate how different combinations of heating and decentralized energy generation systems are affecting the specific energy demand of the building. Also, an analysis on how the Swedish incentive schemes affect the choice of decentralized energy generation systems is conducted. Furthermore, it is investigated if it is necessary to adopt the incentive schemes to steer towards systems that reduce the specific energy demand of the building. The conclusion in this article is that the current incentive system is ineffective in terms of specific energy demand reduction of buildings. It needs to be adapted so it steers towards a reduction of the specific energy demand of buildings.

  6. 太阳能热变换器制蒸汽系统性能研究%Performances of a Steam Generation System With a Solar Assisted Absorption Heat Transformer

    Institute of Scientific and Technical Information of China (English)

    刘锋; 隋军; 刘浩; 金红光

    2015-01-01

    构建了一套蒸汽产量为1 t/h(制热功率为620 kW)的太阳能辅助吸收式热变换器(solar assisted absorption heat transformer,SAAHT)制蒸汽系统,探讨了太阳辐照强度、环境温度以及蒸汽凝水回收率对制热量和系统热效率的影响。结果表明,当太阳辐照强度由200 W/m2增加到1000W/m2时,系统热效率提高20.4个百分点,制热功率增加1090 kW;当环境温度由15℃升高到33℃时,系统热效率先由26.6%缓慢增大至27.8%,然后快速下降至9.27%,制热功率先由593.6kW 增大至619.5 kW ,然后下降至206.6kW。当蒸汽凝水由不回收变化到全回收,系统热效率提高2.75个百分点,制热功率增加61kW。研究提出不同太阳辐照强度、环境温度以及凝水回收率条件下系统最佳集热温度。经济性分析结果表明,该系统产汽成本为162元/t,其替代燃油锅炉和燃气锅炉时,投资回收期介于1.95年和6.70年之间,与燃煤锅炉相比,没有明显的价格优势,但CO2减排量突出。%ABSTRACT:A solar assisted absorption heat transformer (SAAHT) system generating 1 t /h low pressure steam was developed and the influence of solar radiation intensity, ambient temperature and condensate water recovery ratio of low pressure steam on the system thermal efficiency and heat load used by the steam user were studied. When solar radiation intensity ranges from 200W/m2 to 1000W/m2, the system thermal efficiency increases by 20.4 percentage points and heat load for steam user increases 1090 kW. When ambient temperature ranges from 15℃ to 33℃, the system thermal efficiency increases from 26.6% to 27.8%, and then decreases to 9.27%; heat load for steam user increases from 593.6kW to 619.5kW and then decreases to 206.6kW. When condensate water recovery ratio ranges from 0 to 1, the system thermal efficiency increases by 2.75 percentage points and heat load for steam user increases 61kW. Considering the variation

  7. Solar-assisted district heating system - Scientific study. Solar-assisted district heating system with long-term thermal storage in Friedrichshafen-Wiggenhausen and Hamburg-Bramfeld.. Results of the first year of operation; Solar unterstuetzte Nahwaermeversorgung - Wissenschaftliches Begleitprogramm. Solare Nahwaermeversorgung mit Langzeitwaermespeicher in Friedrichshafen-Wiggenhausen und Hamburg-Bramfeld. Ergebnisse des ersten Betriebsjahres

    Energy Technology Data Exchange (ETDEWEB)

    Schulz, M.E.; Mahler, B.; Hahne, E. [Stuttgart Univ. (Germany). Inst. fuer Thermodynamik und Waermetechnik

    1998-12-31

    The first two pilot plants for solar district heating with seasonal thermal energy storage were put in operation in October 1996. Both projects were initiated by the Institute for Thermodynamics and Thermal Energy Technology (ITW) of the University of Stuttgart that also provided scientific support up to the present. This report presents the results of the first two years of operation of both plants. Both solar plants have been operated without any major problems. The solar energy yield in the first year of operation has only been reduced by the unsatisfactory operation of the heating grid. The most important step towards optimising the plants is the adjustment of the internal heating systems and thus the reduction of the heating temperatures which are currently too high. Based on subject pre-conditions the results projected for the first pilot plants for solar district heating and long-term thermal energy storage will be reached in the following years of operation. (orig.) [Deutsch] Im Oktober 1996 gingen die ersten beiden Pilotanlagen zur solaren Nahwaermeversorgung mit saisonaler Waermespeicherung in Betrieb. Beide Projekte wurden vom Institut fuer Thermodynamik und Waermetechnik (ITW), Universitaet Stuttgart initiiert und ueber die gesamte bisherige Laufzeit wissenschaftlich begleitet. Die Ergebnisse des ersten Betriebsjahres der beiden Anlagen sind in diesem Bericht zusammengestellt. In beiden Faellen funktionieren die Solaranlagen ohne grosse Probleme. Die solaren Ertraege wurden im ersten Betriebsjahr noch durch die unzureichende Betriebsweise der Heiznetze gemindert. Wichtigster Ansatzpunkt fuer eine Optimierung der Anlagen ist die Einregulierung der hausinternen Heizungssysteme und damit die Absenkung der derzeit noch zu hohen Heiznetztemperaturen. Unter dieser Voraussetzung werden die vorausgesagten Ergebnisse fuer die ersten Pilotanlagen zur solaren Nahwaerme mit Langzeit-Waermespeicher in den naechsten Betriebsjahren erreicht werden. (orig.)

  8. Thermodynamic analysis of solar assisted multi-functional trigeneration system

    Directory of Open Access Journals (Sweden)

    Önder KIZILKAN

    2016-02-01

    Full Text Available In this study, modelling and thermodynamic analysis of solar assisted trigeneration system was carried out. The required thermal energy for gas and vapor cycles were supplied from solar tower which is a new concept for gas cycle applications. Additionally, an absorption refrigeration cycle, vapor production process, drying process and water heating process were integrated to the system. Energy and exergy efficiencies of the trigeneration system were determined by the application of first and second law analyses. The results showed that the gas cycle efficiency was found to be 31%, vapor cycle efficiency was found to be 28% and coefficient of performance (COP values of the refrigeration system was found to be 0.77. Also the highest exergy destruction rate was found to be 4154 kW in solar tower.Keywords: Solar tower, Trigeneration, Gas cycle, Vapor cycle, Energy, Exergy

  9. Solar Assisted Water Source Heat Pump System for Heating in Winter%关于太阳能辅助水源热泵系统联合冬季供暖的研究

    Institute of Scientific and Technical Information of China (English)

    石东森; 赵展

    2014-01-01

    Along with the increased awareness of energy shortage and environmental protection in China, solar energy and shallow geothermal energy as renewable energy are getting more and more atten-tion. But regardless of the solar system or single water source heat pump system has some limitations, few of joint operation for both applications. Based on the actual project as an example, the solar system can be combined with water source heat pump system, and the system will achieve the required indoor air temper-ature; and the technical analysis of operation cost for solar system with water source heat pump system shows the energy efficiency is completely obvious.%随着我国能源的紧缺和环保意识的加强,太阳能、浅层地热能作为可再生能源,越来越受到人们的重视。但无论是太阳能系统,还是水源热泵系统,单独运行时均有一定的局限性,两者联合运行的应用很少。通过实际工程分析,太阳能系统与水源热泵系统可以联合工作,并可达到预期的室内空调温度;对太阳能系统与水源热泵系统联合运行的运行费用做了技术分析,证实这种联合模式节能效果十分明显。

  10. Analysis of a Hybrid Solar-Assisted Trigeneration System

    Directory of Open Access Journals (Sweden)

    Elisa Marrasso

    2016-09-01

    Full Text Available A hybrid solar-assisted trigeneration system is analyzed in this paper. The system is composed of a 20 m2 solar field of evacuated tube collectors, a natural gas fired micro combined heat and power system delivering 12.5 kW of thermal power, an absorption heat pump (AHP with a nominal cooling power of 17.6 kW, two storage tanks (hot and cold and an electric auxiliary heater (AH. The plant satisfies the energy demand of an office building located in Naples (Southern Italy. The electric energy of the cogenerator is used to meet the load and auxiliaries electric demand; the interactions with the grid are considered in cases of excess or over requests. This hybrid solution is interesting for buildings located in cities or historical centers with limited usable roof surface to install a conventional solar heating and cooling (SHC system able to achieve high solar fraction (SF. The results of dynamic simulation show that a tilt angle of 30° maximizes the SF of the system on annual basis achieving about 53.5%. The influence on the performance of proposed system of the hot water storage tank (HST characteristics (volume, insulation is also studied. It is highlighted that the SF improves when better insulated and bigger HSTs are considered. A maximum SF of about 58.2% is obtained with a 2000 L storage, whereas the lower thermal losses take place with a better insulated 1000 L tank.

  11. Performance test of solar-assisted ejector cooling system

    KAUST Repository

    Huang, Bin-Juine

    2014-03-01

    A solar-assisted ejector cooling/heating system (SACH-2k) is built and test result is reported. The solar-driven ejector cooling system (ECS) is connected in series with an inverter-type air conditioner (IAC). Several advanced technologies are developed in SACH-k2, including generator liquid level control in ECS, the ECS evaporator temperature control, and optimal control of fan power in cooling tower of ECS. From the field test results, the generator liquid level control performs quite well and keeps stable performance of ejector. The ECS evaporator temperature control also performs satisfactorily to keep ejector performance normally under low or fluctuating solar radiation. The fan power control system cooling tower performs stably and reduces the power consumption dramatically without affecting the ECS performance. The test results show that the overall system COPo including power consumptions of peripheral increases from 2.94-3.3 (IAC alone) to 4.06-4.5 (SACH-k2), about 33-43%. The highest COPo is 4.5. © 2013 Elsevier Ltd and IIR. All rights reserved.

  12. STUDY ON SOLAR-ASSISTED HEAT PUMP SYSTEM FOR ELECTRIC VEHICLE AIR CONDITIONING%太阳能辅助电动汽车热泵空调系统的研究

    Institute of Scientific and Technical Information of China (English)

    马国远; 史保新; 陈观生; 吴立志

    2001-01-01

    介绍研制的电动汽车热泵空调系统及其配用的双工作腔滑片压缩机的性能,依据测试样机的试验结果分析了转速对该空调系统制冷量、输入功率及COP等性能的影响。若轿车顶盖全部布满太阳电池,所产生的电能约为225W,可以使空调系统的制冷量增加8%左右,同时还能降低汽车空调冷负荷的峰值。%This paper describes the heat pump system for electric vehicle air conditioning and the sliding vane compressor with double-actions used in the system.According to the experimental results of the sample,the influence of compressor speed on the cooling/heating capacity,power input,and COP of the heat pump system is discussed.The photovoltaic cells,assumed to cover the roof area of a compact car,can only generate about 225W power.This can improve the refrigerating capacity of the heat pump system by about eight percent,which significantly reduces the peak cooling load when the car is parked under the strong sunlight.

  13. Solar Thermal Power Generation 2000: solar-assisted district heating, tight sealing of pit water storage tanks made out of pre-stressed concrete; Solarthermie 2000, TP3: Solarunterstuetzte Nahwaermeversorgung: Dichte Heisswasser - Waermespeicher aus Hochleistungsbeton. Erdbeckenspeicher aus Hochleistungsbeton

    Energy Technology Data Exchange (ETDEWEB)

    Reineck, K.H.; Lichtenfels, A.; Schlaich, J. [Stuttgart Univ. (Germany). Inst. fuer Konstruktion und Entwurf 2

    1998-12-31

    In 1996 the two large heat storage tanks in Hamburg-Bramfeld (4,750 cubic metres) and Friedrichshafen-Wiggenhausen (12,000 cubic metres) were built out of concrete with an inner stainless steel lining. This was a big step towards economic efficiency. The research project ``Tight sealing of pit water storage tanks made out of pre-stressed concrete`` was launched by the BMBF in order to show that the concrete construction will not only bear loads but also ensure sealing. Building costs for underground hot water storage tanks could then be reduced by at least 25%. The first results of this research project are presented. The paper also contains recommendations for the further development of heat storage tanks built with pre-stressed concrete. (orig.) [Deutsch] Im Jahre 1996 wurden die beiden grossen Waermespeicher in Hamburg-Bramfeld mit einem Volumen von 4.750 m{sup 3} und in Friedrichshafen-Wiggenhausen mit 12.000 m{sup 3} aus Beton mit innenliegender Edelstahlauskleidung fertiggestellt. Mit dem Bau dieser beiden Grossspeicher konnte ein richtungsweisender Schritt hin zur Wirtschaftlichkeit gemacht werden, wie man es in Studien vor 15 Jahren nicht fuer moeglich hielt. Mit dem BMBF - Forschungsvorhaben `Dichte Heisswasser - Waermespeicher aus Hochleistungsbeton` soll gezeigt werden, dass das Betontragwerk nicht nur Lasten abtragen sondern auch die Funktion der Abdichtung uebernehmen kann. Damit sollen die Baukosten fuer unterirdische Heisswasser-Waermespeicher um mindestens 25% gesenkt werden. Es werden die ersten Ergebnisse dieses Forschungsvorhabens mitgeteilt und Empfehlungen fuer die weitere Entwicklung von Waermespeichern aus Hochleistungsbeton gegeben. (orig.)

  14. The development of solar-assisted gas-fired appliances: phase ii. Final report dec 80-nov 81

    Energy Technology Data Exchange (ETDEWEB)

    Hagen, K.G.; Levine, A.; Colarusso, J.M.; Zakak, A.I.

    1981-12-01

    An evaluation of applying solar assistance to commercial laundry drying and supermarket dehumidification was accomplished. The laundry drying project included experimental evaluation of the transient and steady-state characteristics of the hot air produced by an air-heating solar collector; experimental evaluation of the performance characteristics of a gas-fired laundry dryer as affected by varying the inlet air temperature and humidity; and an assessment of the characteristics of commercial laundries in relation to the potential commercialization of the solar-assisted dryer concept. The supermarket dehumidification project included an assessment of the relative latent and sensible cooling requirements as a function of geographic location; typical design studies of the performance and cost effectiveness of desiccant dehumidification systems in this application; and the incremental effectiveness of solar assistance to desiccant regeneration. In both projects, the solar-assist feature is, at best, marginally cost effective, including incentives, in the near term; however, the gas-fired only desiccant dehumidification concept is shown to be a potentially attractive alternative to vapor compression dehumidification with a potential for widespread application.

  15. Numerical simulation of solar-assisted multi-effect distillation (SMED) desalination systems

    KAUST Repository

    Kim, Youngdeuk

    2013-01-01

    We present a simulation model for the transient behavior of solar-assisted seawater desalination plant that employs the evacuated-tube collectors in conjunction with a multieffect distillation plant of nominal water production capacity of 16m3/day. This configuration has been selected due to merits in terms of environment-friendliness and energy efficiency. The solar-assisted multi-effect distillation system comprises 849 m2 of evacuated-tube collectors, 280 m3 water storage tanks, auxiliary heater, and six effects and a condenser. The present analysis employs a baseline configuration, namely; (i) the local solar insolation input (Jeddah, Saudi Arabia), (ii) a coolant flow rate through the headers of collector based on ASHRAE standards, (iii) a heating water demand, and (iv) the augmentation of water temperature by auxiliary when the supply temperature from the solar tank drops below the set point. It is observed that the annual collector efficiency and solar fraction decrease from 57.3 to 54.8% and from 49.4 to 36.7%, respectively, with an increase in the heating water temperature from 80 to 90 °C. The overall water production rate and the performance ratio increase slightly from 0.18 to 0.21 kg/s and from 4.11 to 4.13, respectively. © 2013 Desalination Publications.

  16. Solar-Assisted Electric Vehicle Charging Station Interim Report

    Energy Technology Data Exchange (ETDEWEB)

    Lapsa, Melissa Voss [ORNL; Durfee, Norman [ORNL; Maxey, L Curt [ORNL; Overbey, Randall M [ORNL

    2011-09-01

    Oak Ridge National Laboratory (ORNL) has been awarded $6.8 million in the Department of Energy (DOE) American Recovery and Reinvestment Act (ARRA) funds as part of an overall $114.8 million ECOtality grant with matching funds from regional partners to install 125 solar-assisted Electric Vehicle (EV) charging stations across Knoxville, Nashville, Chattanooga, and Memphis. Significant progress has been made toward completing the scope with the installation of 25 solar-assisted charging stations at ORNL; six stations at Electric Power Research Institute (EPRI); and 27 stations at Nissan's Smyrna and Franklin sites, with three more stations under construction at Nissan's new lithium-ion battery plant. Additionally, the procurement process for contracting the installation of 34 stations at Knoxville, the University of Tennessee Knoxville (UTK), and Nashville sites is underway with completion of installation scheduled for early 2012. Progress is also being made on finalizing sites and beginning installations of 30 stations in Nashville, Chattanooga, and Memphis by EPRI and Tennessee Valley Authority (TVA). The solar-assisted EV charging station project has made great strides in fiscal year 2011. A total of 58 solar-assisted EV parking spaces have been commissioned in East and Middle Tennessee, and progress on installing the remaining 67 spaces is well underway. The contract for the 34 stations planned for Knoxville, UTK, and Nashville should be underway in October with completion scheduled for the end of March 2012; the remaining three Nissan stations are under construction and scheduled to be complete in November; and the EPRI/TVA stations for Chattanooga, Vanderbilt, and Memphis are underway and should be complete by the end of March 2012. As additional Nissan LEAFs are being delivered, usage of the charging stations has increased substantially. The project is on course to complete all 125 solar-assisted EV charging stations in time to collect meaningful data

  17. Performance investigation of a solar-assisted direct contact membrane distillation system

    KAUST Repository

    Kim, Youngdeuk

    2013-01-01

    This paper presents a solar-assisted direct contact membrane distillation (DCMD) system with novel energy recovery concepts for a continuous 24-h-a-day operation. A temperature modulating scheme is introduced to the solar-thermal system that supplies feed seawater to the DCMD modules. This scheme attenuates extreme temperature fluctuations of the feed water by storing the collected energy during solar-peak hours and reutilizing it throughout the day. Thus, the energy savings is realized yet the feed seawater temperature is maintained within the desired range. Additionally, the system employs heat recovery from the permeate and brine streams to the feed seawater. The simulations for such a system with a shell-and-tube type DCMD modules are carried out to examine the spatial property variations and the sensitivity of system performance (i.e., transmembrane pressure, permeate flux and performance ratio) to the operating conditions (inlet temperature and flow rate) and the fiber dimensions (fiber length and packing density). It is found that there are trade-offs between mean permeate flux and performance ratio with respect to permeate inlet temperature and flow rate and between total distillate production and performance ratio with respect to packing density. For the solar-assisted DCMD system having evacuated-tube collectors of 3360m2 with 160m3 seawater storage tanks and 50 DCMD modules, the annual solar fraction and the collector efficiency are found to be 77% and 53%, respectively, whilst the overall permeate production capacity is 31m3/day. The overall specific thermal energy consumption of the DCMD system with heat recovery is found to be 436kWh/m3 and it is about 43% lower as compared to the system without heat recovery. It is observed that the specific thermal energy consumption decreases significantly by 55% with increased collector area from 1983m2 to 3360m2 whereas the specific electrical energy consumption increases slightly by 16%. © 2012 Elsevier B.V.

  18. Performance Assessment of a Solar-Assisted Desiccant-Based Air Handling Unit Considering Different Scenarios

    Directory of Open Access Journals (Sweden)

    Giovanni Angrisani

    2016-09-01

    Full Text Available In this paper, three alternative layouts (scenarios of an innovative solar-assisted hybrid desiccant-based air handling unit (AHU are investigated through dynamic simulations. Performance is evaluated with respect to a reference system and compared to those of the innovative plant without modifications. For each scenario, different collector types, surfaces and tilt angles are considered. The effect of the solar thermal energy surplus exploitation for other low-temperature uses is also investigated. The first alternative scenario consists of the recovery of the heat rejected by the condenser of the chiller to pre-heat the regeneration air. The second scenario considers the pre-heating of regeneration air with the warmer regeneration air exiting the desiccant wheel (DW. The last scenario provides pre-cooling of the process air before entering the DW. Results reveal that the plants with evacuated solar collectors (SC can ensure primary energy savings (15%–24% and avoid equivalent CO2 emissions (14%–22%, about 10 percentage points more than those with flat-plate collectors, when the solar thermal energy is used only for air conditioning and the collectors have the best tilt angle. If all of the solar thermal energy is considered, the best results with evacuated tube collectors are approximately 73% in terms of primary energy saving, 71% in terms of avoided equivalent CO2 emissions and a payback period of six years.

  19. Solar-assisted smokehouse for the drying of natural rubber on small-scale Indonesian farms

    Energy Technology Data Exchange (ETDEWEB)

    Breymayer, M.; Pass, T.; Muehlbauer, W. (Hohenheim Univ., Stuttgart (Germany). Inst. for Agricultural Engineering in the Tropics and Subtropics); Amir, E.J.; Mulato, S. (Bogor Research Inst. for Estate Crops, Bogor (Indonesia))

    1993-11-01

    Natural rubber in Indonesia is mainly produced by smallholder farmers and-being the highest foreign currency generating agricultural commodity-is of great importance for the Indonesian economy. Nevertheless, due to the lack of appropriate dryers, more than 80% of the total production has to be sold as low-grade Standard Indonesian Rubber (SIR) for a relatively low price. In order to improve the product quality, a solar-heated rubber sheet dryer was developed. It consists of a flat-plate solar air heater connected to a drying chamber. Part-recirculation of the exhaust air leads to the desired drying air temperature of 45-60[sup o]C and results in a significant reduction of the drying time. To enable drying independent of weather conditions, a biomass furnace was incorporated underneath the drying chamber. The simple design of the solar-assisted smokehouse allows local production and after further improvements seems to be an economical alternative for farmer groups or nucleus estates. (Author)

  20. Optimal control and performance test of solar-assisted cooling system

    KAUST Repository

    Huang, B.J.

    2010-10-01

    The solar-assisted cooling system (SACH) was developed in the present study. The ejector cooling system (ECS) is driven by solar heat and connected in parallel with an inverter-type air conditioner (A/C). The cooling load can be supplied by the ECS when solar energy is available and the input power of the A/C can be reduced. In variable weather, the ECS will probably operate at off-design condition of ejector and the cooling capability of the ECS can be lost completely. In order to make the ejector operate at critical or non-critical double-choking condition to obtain a better performance, an electronic expansion valve was installed in the suction line of the ejector to regulate the opening of the expansion valve to control the evaporator temperature. This will make the SACH always produce cooling effect even at lower solar radiation periods while the ejector performs at off-design conditions. The energy saving of A/C is experimentally shown 50-70% due to the cooling performance of ECS. The long-term performance test results show that the daily energy saving is around 30-70% as compared to the energy consumption of A/C alone (without solar-driven ECS). The total energy saving of A/C is 52% over the entire test period. © 2010 Elsevier Ltd. All rights reserved.

  1. Development of a Solar Assisted Drying System Using Double-Pass Solar Collector with Finned Absorber

    Science.gov (United States)

    Azmi, M. S. M.; Othman, M. Y.; Sopian, K.; Ruslan, M. H.; Majid, Z. A. A.; Fudholi, A.; Yasin, J. M.

    2012-09-01

    The Solar Energy Research Group, Universiti Kebangsaan Malaysia, International Islamic University Malaysia and Yayasan FELDA has designed and constructed a solar assisted drying system at OPF FELDA Factory, Felda Bukit Sagu 2, Kuantan, Pahang. The drying system has a total of six double-pass solar collectors. Each collector has a length of 480 cm and a width of 120 cm. The first channel depth is 3.5 cm and the second channel depth is 7 cm. Longitudinal fins made of angle aluminium, 0.8 mm thickness were attached to the bottom surface of the absorber plate. The solar collectors are arranged as two banks of three collectors each in series. Internal manifold are used to connect the collectors. Air enters through the first channel and then through the second channel of the collector. An auxiliary heater source is installed to supply heat under unfavourable solar radiation condition. An on/off controller is used to control the startup and shutdown of the auxiliary heater. An outlet temperature of 70-75 °C can be achieved at solar radiation range of 800-900 W/m2 and flow rate of 0.12 kg/s. The average thermal efficiency of a solar collector is approximately 37%.

  2. 太阳能辅助供热挂面烘房热能构成与应用潜力分析%Analysis of Heat Energy Constitution and Application Potential about Solar-assist-ed Heat Supply Noodle Drying Chamber in Chinese Dried Noodle Drying Process

    Institute of Scientific and Technical Information of China (English)

    武亮; 刘锐; 于晓磊; 张影全; 张波; 魏益民

    2015-01-01

    为研究太阳能辅助供热挂面烘房的热能构成、节能效果及建设和管理成本,本文以某一挂面生产企业的太阳能-燃煤供热锅炉和挂面干燥生产车间为研究对象,分别于2015年4.28—4.29、6.01—6.03和7.28—7.29,分3次9d监测了不同时间段的耗煤量(243~251MJ/kg)、太阳能利用时长、挂面产量和蒸发水分的质量。分析结果表明:在调查时间内燃煤单独供热平均时长16.50h,单位煤耗28.60~32.05kg/t;太阳能结合燃煤供热平均时长5.64h,单位煤耗18.32~20.53kg/t,太阳能供热占比35.94%;太阳能单独供热(未使用燃煤系统)平均时长1.88h。太阳能辅助供热挂面烘房平均煤耗为23.97~26.86kg/t;太阳能为该段时间生产提供了17.51%的能量,相当于节约燃煤257.94kg,约等于生产8.05~9.02t挂面所耗煤量。以全年生产200d计,估计每年可节约标准煤43.48t,减少碳排放113.05t;以燃煤(243~251MJ/kg)到厂价600~800元计,可节约生产成本30953~41271元。%For studying heat energy constitution, energy-saving effect and cost of installation and maintenance about solar energy assisted heat supply drying noodle drying process in chamber, a production line which energy was supplied by solar and coal was chosen as research object, coal consumption in different time periods, time of solar energy utilized and noodle produc-tion were monitored, 9 days survey was conducted during 4.28-4.29, 6.01-6.03, 7.28-7.29, 2015. Results showed that, in survey period, average time of coal heating alone was 16.5h, unit coal consumption was 28.60-32.05kg/t (noodle product); so-lar combined with coal heating 5.64h, unit coal consumption was 18.32-20.53kg/t, share 37.12%of total energy consumption in this period; solar heating alone (without coal) 1.88h; share17.51%about whole energy consumption in noodle production of all day, equivalent to saving coal 257.94kg, approximately equal to coal consumption

  3. Assessing the Robustness of Thermoeconomic Diagnosis of Fouled Evaporators: Sensitivity Analysis of the Exergetic Performance of Direct Expansion Coils

    Directory of Open Access Journals (Sweden)

    Antonio Piacentino

    2016-03-01

    Full Text Available Thermoeconomic diagnosis of refrigeration systems is a pioneering approach to the diagnosis of malfunctions, which has been recently proven to achieve good performances for the detection of specific faults. Being an exergy-based diagnostic technique, its performance is influenced by the trends of exergy functions in the “design” and “abnormal” conditions. In this paper the sensitivity of performance of thermoeconomic diagnosis in detecting a fouled direct expansion coil and quantifying the additional consumption it induces is investigated; this fault is critical due to the simultaneous air cooling and dehumidification occurring in the coil, that induce variations in both the chemical and thermal fractions of air exergy. The examined parameters are the temperature and humidity of inlet air, the humidity of reference state and the sensible/latent heat ratio (varied by considering different coil depths. The exergy analysis reveals that due to the more intense dehumidification occurring in presence of fouling, the exergy efficiency of the evaporator coil eventually increases. Once the diagnostic technique is based only on the thermal fraction of air exergy, the results suggest that the performance of the technique increases when inlet air has a lower absolute humidity, as evident from the “optimal performance” regions identified on a psychrometric chart.

  4. Solar-Laundry - Solar-assisted air-conditioning of a laundry in Vienna; Solar-Laundry - Solare Klimatisierung einer Wiener Waescherei

    Energy Technology Data Exchange (ETDEWEB)

    Selke, T.; Neuhaeuser, M.; Pol, O. [arsenal research, Wien (Austria). Geschaeftsfeld Nachhaltige Energiesysteme

    2005-07-01

    Laundry enterprises produce immense amounts of waste heat due to the applied machines (washing machines, ironing machines, steam dolls). Consequently the indoor climate of the production area is dominated by high temperature and humidity values both in summer and in winter. Without any air-conditioning the climatic working conditions wouldn't be acceptable for the employees. The aim of the project >>Solar-Laundry<< is to design and implement a solar-assisted air-conditioning system in Vienna into the existing building services. By optimisation of the existing ventilation system and by the use of both solar heat and biomass heat the innovative air-conditioning plant demonstrates an ecological and energy-efficient technical application. The main project objectives are: 1. Significant improvement of indoor air comfort, 2. Installation of an innovative and sustainable energy system for air-conditioning with an acceptable surplus of investment, 3. Reduction of both primary energy consumption and energy costs compared to conventional air-conditioning systems. The participants in the >>Solar-Laundry<< project are: WienWork, TB-Holzinger Ingenieurgesellschaft m.b.H., pos architekten schneider ZT Keg, Oesterreichische Forschungs- und Pruefzentrum Arsenal GmbH. The solar-assisted air-conditioning system is the first plant in Vienna. The commissioning of the >>Solar-Laundry<< plant is scheduled for summer 2005. (orig.)

  5. Solar-assisted dual-effect adsorption cycle for the production of cooling effect and potable water

    KAUST Repository

    Ng, K. C.

    2009-05-17

    This paper investigates the performance of a solar-assisted adsorption (AD) cycle which produces two useful effects, namely cooling and desalination, with only a low-temperature heat input such as thermal energy from solar collectors. Heat sources varying from 65 to 80°C can be obtained from 215-m2 flat plate-type solar collectors to regenerate the proposed silica gel-water-based AD cycle. In this paper, both mathematical modelling and experimental results from the AD cycle operation are discussed, in terms of two key parameters, namely specific daily water production (SDWP) and specific cooling capacity (SCC). The experimental results show that the AD cycle is capable of producing chilled water at 7 to 10°C with varying SCC range of 25-35 Rton/tonne of silica gel. Simultaneously, the AD cycle produces a SDWP of 3-5 m3 per tonne of silica gel per day, rendering it as a dual-effect machine that has an overall conversion or performance ratio of 0.8-1.1. © The Author 2009. Published by Oxford University Press. All rights reserved.

  6. Direct expansion in the estimate of agricultural cultures by regular segments

    Directory of Open Access Journals (Sweden)

    Rogério Teixeira de Faria

    2005-04-01

    Full Text Available The objective of this work was to develop a method to estimate the crop area of coffee, maize and soybean in the region of Cornélio Procópio, Paraná State, Brazil. This region comprises a total of 23 municipalities. The direct expansion method with regular segments of 1 km x 1 km was used to estimate the crop area. The stratification was carried out with remote sensing satellite images, digital image classification procedure, Geographic Information System (GIS, GPS (Global Positioning System among others. The sampled area was 1.26% of the region which corresponds to 89 segments. These segments were visited during a field work from October 29th to December 10th of 2002. Comparison between the results of this research and the official estimates indicated that best results were obtained for soybean area estimation, which occupies 32.1% of the region. The soybean area estimation had a difference of 5.9% in relation to the official estimate and a coefficient of variation equal to 6.6%. The result was available one week after the end of the field work indicating that the method is fast. The conclusions of the work are: 1 the thematic map of the images makes it possible to stratify the region and can also be helpful to the subjective surveys; 2 the regular segments were easily located in the field, with the use of the GPS; 3 the crop area estimation was fast and met the opportunity criteria; 4 an error figure is associated to the estimates, attending the reliability criteria and; 5 the errors of the estimates varied in response to the cultivated area by each crop in the region.

  7. Optimization of a solar-assisted drying system for drying bananas

    Energy Technology Data Exchange (ETDEWEB)

    Smitabhindu, R. [Department of Industrial Engineering, Kasetsart University, Bangkok 10900 (Thailand); Janjai, S. [Department of Physics, Faculty of Science, Silpakorn University, Nakhon Pathom 73000 (Thailand); Chankong, V. [Department of Electrical Engineering and Computer Science, Case Western Reserve University, Cleveland, OH (United States)

    2008-07-15

    This paper presents a mathematical model for optimal design of a solar-assisted drying system for drying bananas. The optimization model consists of a simulation model of a solar-assisted drying system combined with an economic model. The simulation model is composed of two systems of differential equations: one for the collector and other for the drying cabinet. These systems of the differential equation were solved using the finite difference method. Values of the model parameters were determined experimentally. A computer program in FORTRAN was developed to simulate the performance of the drying system. The model was validated by comparing the simulation results with the experimental results and they were in good agreement. This simulation model was used for the optimization of the solar-assisted drying system. An economic model was formulated to calculate the annual drying cost. The optimization problem was defined as the optimization of the geometry and operational parameters of the drying system so as to minimize the drying cost per unit of dried product. Currently used collector area and the air recycle factor were considered as the parameters for basic mode of operation of the drying system. The adaptive pattern search technique was adopted to find the optimum values of the solar collector area and the recycle factor. The optimum values of the collector area and the recycle factor were found to be 26 m{sup 2} and 90%, respectively. The computer program developed in this study can be used to optimize similar drying systems. (author)

  8. Solar assisted alkali pretreatment of garden biomass: Effects on lignocellulose degradation, enzymatic hydrolysis, crystallinity and ultra-structural changes in lignocellulose.

    Science.gov (United States)

    Gabhane, Jagdish; William, S P M Prince; Vaidya, Atul N; Das, Sera; Wate, Satish R

    2015-06-01

    A comprehensive study was carried out to assess the effectiveness of solar assisted alkali pretreatment (SAAP) on garden biomass (GB). The pretreatment efficiency was assessed based on lignocellulose degradation, conversion of cellulose into reducing sugars, changes in the ultra-structure and functional groups of lignocellulose and impact on the crystallinity of cellulose, etc. SAAP was found to be efficient for the removal of lignin and hemicellulose that facilitated enzymatic hydrolysis of cellulose. FTIR and XRD studies provided details on the effectiveness of SAAP on lignocellulosic moiety and crystallinity of cellulose. Scanning electron microscopic analysis showed ultra-structural disturbances in the microfibrils of GB as a result of pretreatment. The mass balance closer of 97.87% after pretreatment confirmed the reliability of SAAP pretreatment. Based on the results, it is concluded that SAAP is not only an efficient means of pretreatment but also economical as it involved no energy expenditure for heat generation during pretreatment.

  9. Design, Development and Performance Evaluation of a Small Scale Solar Assisted Paddy Dryer for on Farm Processing

    Directory of Open Access Journals (Sweden)

    Sidrah Ashfaq

    2016-04-01

    Full Text Available With the continued escalation in population growth and the expansion of international food trade and demand of high quality product for food security at low cost has created considerable interest in the development of new post-harvest technologies. This is particularly important for developing countries where post-harvest losses of cereals are between 10-20% and of fruits and vegetables as high as 20- 100% A new solar assisted paddy dryer with central air distribution model (along the length of drying chamber has been developed. Due to this distinct feature of the dryer high drying rate was achieved during the drying processes .Other components of the dryer are perforated drying chamber, blower and flat plat solar air collector. Dryer was evaluated using 100kg of freshly harvested paddy at 23.78% moisture content (wb. Performance evaluation results showed that the mean drying rate of the solar assisted paddy dryer was 0.87kg/hr per for every 100kg, whereas 0.46kg/hr was the sun drying rate comparatively. The faster drying rate of the dryer reveals its suability to dry the paddy for its safe storage moisture content rapidly. By using the solar assisted paddy dryer, approximately 50% saving in time was also achieved as compared with the traditional sun drying method. Solar assisted paddy dryer took 10hr for drying the 100kg paddy up to 14%, while sun drying method dried paddy up to 13.89% in 19 hours. Cost analysis also showed that, by using solar assisted paddy dryer we candry good quality paddy at low cost as compared with the open sun drying method. For development of agriculture in the rural areas, commercial size of the solar assisted paddy dryer can be amplified and produced at community level.

  10. Dynamic behavior of a direct expansion evaporator under frosting condition. Part II. Field investigation on a shipping container

    Energy Technology Data Exchange (ETDEWEB)

    Tso, C.P. [Multimedia University, Melaka (Malaysia). Faculty of Engineering and Technology; Cheng, Y.C.; Lai, A.C.K. [Nanyang Technological University, Singapore 634798 (Singapore). School of Mechanical and Aerospace Engineering

    2006-06-15

    A field investigation is performed on the frost formation at an evaporator of a commercial full-scale refrigerated container that uses R-12 as the working refrigerant. Results when compared with those from a numerical model presented earlier show that the model is capable of predicting the dynamic behavior of a direct expansion evaporator under both non-frosting and frosting conditions. The air outlet and energy transferred compare well between experiment and model, and within 20% for the air pressure drop. The frost occurrence and propagation agree well generally, with the frost formation first occurring at the first row where the refrigerant enters the evaporator. (author)

  11. ANN based optimization of a solar assisted hybrid cooling system in Turkey

    Energy Technology Data Exchange (ETDEWEB)

    Ozgur, Arif; Yetik, Ozge; Arslan, Oguz [Mechanical Eng. Dept., Engineering Faculty, Dumlupinar University (Turkey)], email: maozgur@dpu.edu.tr, email: ozgeyetik@dpu.edu.tr, email: oarslan@dpu.edu.tr

    2011-07-01

    This study achieved optimization of a solar assisted hybrid cooling system with refrigerants such as R717, R141b, R134a and R123 using an artificial neural network (ANN) model based on average total solar radiation, ambient temperature, generator temperature, condenser temperature, intercooler temperature and fluid types. ANN is a new tool; it works rapidly and can thus be a solution for design and optimization of complex power cycles. A unique flexible ANN algorithm was introduced to evaluate the solar ejector cooling systems because of the nonlinearity of neural networks. The conclusion was that the best COPs value obtained with the ANN is 1.35 and COPc is 3.03 when the average total solar radiation, ambient temperature, generator temperature, condenser temperature, intercooler temperature and algorithm are respectively 674.72 W/m2, 17.9, 80, 15 and 13 degree celsius and LM with 14 neurons in single hidden layer, for R717.

  12. DIRECT EXPANSIONS FOR THE DISTRIBUTION FUNCTIONS AND DENSITY FUNCTIONS OF x2-TYPE AND t-TYPE DISTRIBUTED RANDOM VARIABLES

    Institute of Scientific and Technical Information of China (English)

    ZHENGZUKANG

    1996-01-01

    Suppose that Z1,Z2…,Zn are independent normal random variables with common mean μ and variance σ2. Then S2=∑n n=1 (zi-z)2/σ2 and T =(n-1的平方根)-Z/(S2/n的平方根) have x2n-1 distribution and tn-1 distribution respectively. If the normal assumption fails, there will be the remainders of the distribution functions and density functions. This paper gives the direct expansions of distribution functions and density functions of S2 and T up to o(n-1). They are more intuitive and convenient than usual Edgeworth expansions.

  13. Control strategies study of a complete solar assisted air conditioning system in an office building using TRNSYS

    OpenAIRE

    Thomas, Sébastien; Andre, Philippe

    2009-01-01

    It is now clearly assumed that solar assisted air conditioning is able to minimize environmental impact and CO2 production of buildings operation. How to reach highest energy savings is still a work in progress. In former literature, equipment control has been point out as a critical feature of energy consumption. Control becomes more and more important as system is complex. The complete simulation environment was developed in previous work, it includes the absorption chiller ...

  14. Renewables for Heating and Cooling

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2007-07-01

    This timely report examines the technologies, current markets and relative costs for heat and cold production using biomass, geothermal and solar-assisted systems. It evaluates a range of national case studies and relevant policies. Should the successful and more cost-effective policies be implemented by other countries, then the relatively untapped economic potential of renewable energy heating and cooling systems could be better realised, resulting in potential doubling of the present market within the next few years.

  15. Solar assisted alkali pretreatment of garden biomass: Effects on lignocellulose degradation, enzymatic hydrolysis, crystallinity and ultra-structural changes in lignocellulose

    Energy Technology Data Exchange (ETDEWEB)

    Gabhane, Jagdish [Solid and Hazardous Waste Management Division, National Environmental Engineering Research Institute, Nehru Marg, Nagpur 440020, Maharashtra (India); William, S.P.M. Prince, E-mail: spmp_william@neeri.res.in [Solid and Hazardous Waste Management Division, National Environmental Engineering Research Institute, Nehru Marg, Nagpur 440020, Maharashtra (India); Vaidya, Atul N. [Solid and Hazardous Waste Management Division, National Environmental Engineering Research Institute, Nehru Marg, Nagpur 440020, Maharashtra (India); Das, Sera [Analytical Instrumentation Division, National Environmental Engineering Research Institute, Nehru Marg, Nagpur 440020, Maharashtra (India); Wate, Satish R. [Solid and Hazardous Waste Management Division, National Environmental Engineering Research Institute, Nehru Marg, Nagpur 440020, Maharashtra (India)

    2015-06-15

    Highlights: • SAAP is an efficient and economic means of pretreatment. • SAAP was found to be efficient in lignin and hemicellulose removal. • SAAP enhanced the enzymatic hydrolysis. • FTIR, XRD and SEM provided vivid understanding about the mode of action of SAAP. • Mass balance closer of 98% for pretreated GB confirmed the reliability of SAAP. - Abstract: A comprehensive study was carried out to assess the effectiveness of solar assisted alkali pretreatment (SAAP) on garden biomass (GB). The pretreatment efficiency was assessed based on lignocellulose degradation, conversion of cellulose into reducing sugars, changes in the ultra-structure and functional groups of lignocellulose and impact on the crystallinity of cellulose, etc. SAAP was found to be efficient for the removal of lignin and hemicellulose that facilitated enzymatic hydrolysis of cellulose. FTIR and XRD studies provided details on the effectiveness of SAAP on lignocellulosic moiety and crystallinity of cellulose. Scanning electron microscopic analysis showed ultra-structural disturbances in the microfibrils of GB as a result of pretreatment. The mass balance closer of 97.87% after pretreatment confirmed the reliability of SAAP pretreatment. Based on the results, it is concluded that SAAP is not only an efficient means of pretreatment but also economical as it involved no energy expenditure for heat generation during pretreatment.

  16. Preliminary design package for residential heating/cooling system--Rankine air conditioner redesign

    Energy Technology Data Exchange (ETDEWEB)

    1978-12-01

    This report contains a summary of the preliminary redesign and development of a marketable single-family heating and cooling system. The objectives discussed are the interim design and schedule status of the Residential (3-ton) redesign, problem areas and solutions, and the definition of plans for future design and development activities. The proposed system for a single-family residential heating and cooling system is a single-loop, solar-assisted, hydronic-to-warm-air heating subsystem with solar-assisted domestic water heating and a Rankine-driven expansion air-conditioning subsystem.

  17. Preliminary design package for residential heating/cooling system: Rankine air conditioner redesign

    Science.gov (United States)

    1978-01-01

    A summary of the preliminary redesign and development of a marketable single family heating and cooling system is presented. The interim design and schedule status of the residential (3-ton) redesign, problem areas and solutions, and the definition of plans for future design and development activities were discussed. The proposed system for a single-family residential heating and cooling system is a single-loop, solar-assisted, hydronic-to-warm-air heating subsystem with solar-assisted domestic water heating and a Rankine-driven expansion air-conditioning subsystem.

  18. Development of a solar-assisted curing process for cigar tobacco; Entwicklung eines solargestuetzten Trocknungsverfahrens fuer Zigarrentabak

    Energy Technology Data Exchange (ETDEWEB)

    Bux, M.

    1996-12-31

    The newly developed solar-assisted drying plant permitted to reduce drying time from between 30 and 40 days to between 18 and 22 days, and to increase the amount filled in from approximately 27 to 67 kilogrammes per square metre. Leaf loss during drying was cut down from between 4 and 6 per cent as previously to about 0.2 per cent. Specific energy demand was by a factor of 12 lower than the demand of conventional driers: the actual demand was 4.8 MJ per kilogramme of tobacco as compared to 58 MJ per kilogramme previously. Taking into account capital, labour, energy and repair costs, a rise in proceeds from solar-dried tobacco of about US $ 1.50 per kilogramme, and the cost involved by higher leaf loss using the conventional technique, drying cost using the solar-assisted method was US $ 2.16 per kilogramme of tobacco. For the conventional method, drying cost was US $ 4.74 per kilogramme. Accordingly, the amortization period of the solar-assisted plant is only two to three years. The solar-assisted method would only cease to be economical if investment costs were increased by 64 per cent, if the interest rate went up to 44 per cent or if the costs arising from leaf loss dropped to US $ 0.8. (orig./HW) [Deutsch] Durch den Einsatz der neu entwickelten solargestuetzten Trocknungsanlage konnte die Trocknungsdauer von bislang 30 bis 40 auf 18 bis 22 Tage reduziert und die Fuellmenge von ca. 27 auf 67 kg/m{sup 2} gesteigert werden. Die Blattverluste waehrend der Trocknung wurden von bislang 4 bis 6% auf ca. 0,2% gesenkt. Der spezifische Energiebedarf war mit 4,8 gegenueber 58 MJ/kg Tabak um den Faktor 12 geringer als der Bedarf konventionller Trockner. Unter Beruecksichtigung von Kapital-, Arbeits-, Energie- und Reparaturkosten, des im Mittel um 1,5 US Dollar/kg hoeheren Stueckerloeses solargetrockneten Tabaks, sowie der Kosten aufgrund der hoeheren Blattverluste beim konventionellen Verfahren, betrugen die Trocknungsstueckkosten des solargestuetzten Verfahrens 2,16 US

  19. Solar assisted ventilation tower, Frederiksberg[Denmark]; Ventilationsanlaeggenes betydning for ejendommens varmeforbrug. Delrapport 1

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2002-04-01

    The project has demonstrated a building integrated ventilation system with the ducts system installed outside the facade. The air ducts are installed in a solar tower parallel to the staircases in the courtyard. The towers utilise the solar energy for preheating the ventilation air. An air handling unit with counterflow heat exchanger is installed in the roof space. The system is designed for old building block, which are going to be renovated with mechanical ventilation. The system saves room space for the installations of the ventilation ducts. The monitoring of the system performance shows energy saving of 40% caused by new windows, individual heat meters and ventilation with heat recovery and solar tower. The system efficiency of the solar tower is high compared with other traditional solar wall constructions. The ventilation system is designed with a very low electricity consumption of the fans. The monitored electricity consumption is 22 W per dwellings. (au)

  20. Energy and economic analysis of biogas heated livestock buildings

    Energy Technology Data Exchange (ETDEWEB)

    Axaopoulos, P.; Panagakis, P. [Agricultural University of Athens (Greece). Laboratory of Farm Structures

    2003-03-01

    The possibility to cover the annual space-heating requirements of a typical swine nursery by the methane produced using a solar-assisted anaerobic digester of innovative design, is studied for two Greek areas. Simulation is used to predict the hourly temperature and relative humidity inside the early-weaned piglet unit, along with the heating energy requirements to keep indoor conditions within pigs' production space. The methane produced by the solar- assisted anaerobic digester is also calculated using a detailed simulation algorithm. The results showed that the methane produced from the solar-assisted anaerobic digester completely ensures not only full coverage of the annual space-heating requirements of the described piglet unit for both Greek areas, but also large methane surplus which could be used in various other ways. A simple sensitivity analysis concerning the economics of the solar-assisted anaerobic digester indicated that its profitability strongly depends on to what extent the produced methane is used. (author)

  1. Performance evaluation of solar assisted dryers for low temperature drying applications: Pt. 1; Plants description

    Energy Technology Data Exchange (ETDEWEB)

    Arata, A. (Universidad Tecnica Federico Santa Maria, Valparaiso (Chile)); Sharma, V.K. (Commission of the European Communities, Ispra (Italy))

    1991-01-01

    Research aimed at investigating the most appropriate cost effective food preservation technology suitable for implementation with limited financial resources is reported. It is hoped that the simple designs discussed in the present communication can be fabricated by small-scale industries using simple tools and relatively cheap and locally available materials. This first paper presents a detailed description, along with a preliminary heat transfer analysis, for fruit dryers developed and tested experimentally. Results obtained from the experiments conducted will be reported in a second paper. (author).

  2. Feasibility of a solar-assisted winter air-conditioning system using evaporative air-coolers

    Directory of Open Access Journals (Sweden)

    Mohamed M. El-Awad

    2011-03-01

    Full Text Available The paper presents a winter air-conditioning system which is suitable for regions with mildly cold but dry winters. The system modifies the evaporative air-cooler that is commonly used for summer air-conditioning in such regions by adding a heating process after the humidification process. The paper describes a theoretical model that is used to estimate the system's water and energy consumption. It is shown that a 150-LPD solar heater is adequate for air-conditioning a 500 ft3/min (14.4 m3/min air flow rate for four hours of operation. The maximum air-flow rate that can be heated by a single solar water-heater for four hours of operation is about 900-cfm, unless a solar water heater large than a 250-LPD heater is used. For the 500 ft3/min air flow rate the paper shows that the 150, 200, 250 and 300 LPD solar water-heaters can provide air-conditioning for 4, 6, 8 and 10 hours, respectively, while consuming less energy than the equivalent refrigerated-type air-conditioner.

  3. Feasibility of a solar-assisted winter air-conditioning system using evaporative air-coolers

    Energy Technology Data Exchange (ETDEWEB)

    El-Awad, Mohamed M. [Mechanical Engineering Department, the University of Khartoum, P.O. Box 321 Khartoum (Sudan)

    2011-07-01

    The paper presents a winter air-conditioning system which is suitable for regions with mildly cold but dry winters. The system modifies the evaporative air-cooler that is commonly used for summer air-conditioning in such regions by adding a heating process after the humidification process. The paper describes a theoretical model that is used to estimate the system's water and energy consumption. It is shown that a 150-LPD solar heater is adequate for air-conditioning a 500 ft3/min (14.4 m3/min) air flow rate for four hours of operation. The maximum air-flow rate that can be heated by a single solar water-heater for four hours of operation is about 900-cfm, unless a solar water heater large than a 250-LPD heater is used. For the 500 ft3/min air flow rate the paper shows that the 150, 200, 250 and 300 LPD solar water-heaters can provide air-conditioning for 4, 6, 8 and 10 hours, respectively, while consuming less energy than the equivalent refrigerated-type air-conditioner.

  4. Economic analysis of solar assisted absorption chiller for a commercial building

    Science.gov (United States)

    Antonyraj, Gnananesan

    Dwindling fossil fuels coupled with changes in global climate intensified the drive to make use of renewable energy resources that have negligible impact on the environment. In this attempt, the industrial community produced various devices and systems to make use of solar energy for heating and cooling of building space as well as generate electric power. The most common components employed for collection of solar energy are the flat plate and evacuated tube collectors that produce hot water that can be employed for heating the building space. In order to cool the building, the absorption chiller is commonly employed that requires hot water at high temperatures for its operation. This thesis deals with economic analysis of solar collector and absorption cooling system to meet the building loads of a commercial building located in Chattanooga, Tennessee. Computer simulations are employed to predict the hourly building loads and performance of the flat plate and evacuated tube solar collectors using the hourly weather data. The key variables affecting the economic evaluation of such system are identified and the influence of these parameters is presented. The results of this investigation show that the flat plate solar collectors yield lower payback period compared to the evacuated tube collectors and economic incentives offered by the local and federal agencies play a major role in lowering the payback period.

  5. An improved assessment model of variable frequency-driven direct expansion air-conditioning system in commercial buildings for Taiwan green building rating system

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Kuan-Hsiung [Department of Mechanical and Electro-mechanical Engineering, National Sun Yet-Sen University, 70 Lien-hai Rd., Kaohsiung 804 (China); Hwang, Ruey-Lung [Department of Safety and Health of Occupant, China Medical University, 91 Huseh-Shin Rd, Taichung, 404 (China)

    2007-10-15

    Because of the superior performance of the multi-unit variable frequency-driven (VFD) direct expansion (DX) air-conditioning system, installing this kind of system in rental commercial buildings, dwelling houses, and schools is becoming more and more popular in Taiwan. Even though the features and characteristics of the multi-unit VFD DX system are different from those of the central system, it is still assessed by the conventional method used for evaluating the efficiency of all air-conditioning systems, which is designed mainly for central systems. This article explains the problems that occur when the current assessment method is applied to the multi-unit VFD DX system. An alternative assessment method is proposed. (author)

  6. Efficient mineralization of the antibiotic trimethoprim by solar assisted photoelectro-Fenton process driven by a photovoltaic cell.

    Science.gov (United States)

    Zhang, Yanyu; Wang, Aimin; Tian, Xiujun; Wen, Zhenjun; Lv, Hanjiao; Li, Desheng; Li, Jiuyi

    2016-11-15

    In this study, a novel self-sustainable solar assisted photoelectro-Fenton (SPEF) system driven by a solar photovoltaic cell was developed for the efficient mineralization of antibiotic trimethoprim (TMP) in water. A comparative degradation of 200mgL(-1) TMP by RuO2/Ti anodic oxidation (AO), anodic oxidation with H2O2 electrogeneration (AO-H2O2), electro-Fenton (EF) and SPEF was investigated. SPEF was proved to exhibit the highest oxidation power, i.e., more than 80% TOC was removed after 360min SPEF treatment of 200mgL(-1) of TMP under optimal conditions at pH 3.0, 1.0mM Fe(2+) and 18mAcm(-2). Influences of current density, pH, initial Fe(2+) and initial TMP concentration on SPEF process were also studied. Ten aromatic intermediates generated from hydroxylation, carbonylation and demethylation reactions were identified using UPLC-QTOF-MS/MS system during the SPEF treatment, together with three carboxylic acids (oxamic, oxalic and formic acids) and two inorganic ions (NH4(+) and NO3(-)) measured. Therefore, a reasonable pathway of TMP degradation in SPEF process was proposed.

  7. Modelling a solar-assisted air-conditioning system installed in CIESOL building using an artificial neural network

    Energy Technology Data Exchange (ETDEWEB)

    Rosiek, S.; Batlles, F.J. [Dpto. Fisica Aplicada, Universidad de Almeria, 04120 Almeria (Spain); CIESOL, Joint Centre University of Almeria-CIEMAT, 04120 Almeria (Spain)

    2010-12-15

    This paper proposes Artificial Neural Networks (ANN) to model a solar-assisted air-conditioning system installed in the Solar Energy Research Center (CIESOL). This system consists mainly of the single-effect LiBr-H{sub 2}0 absorption chiller fed by water provided from either solar collectors or hot water storage tanks. The present work describes the total solar cooling systems based on absorption chiller and provided only with solar collectors. The experimental data were collected during the cooling period of 2008. ANN was used with the main goal of predicting the efficiency of the chiller and global system using the lowest number of input variables. The configuration 7-8-4 (7 inputs, 8 hidden and 4 output neurons) was found to be the optimal topology. The results demonstrate the accuracy ANN's predictions with a Root Mean Square Error (RMSE) of less than 1.9% and practically null deviation, which can be considered very satisfactory. (author)

  8. ZnO nanoparticles co-doped with Fe3+ and Eu3+ ions for solar assisted photocatalysis.

    Science.gov (United States)

    Yin, Dongguang; Zhang, Le; Song, Kailin; Ou, Yangjuan; Wang, Chengcheng; Liu, Bing; Wu, Minghong

    2014-08-01

    In this study, ZnO nanoparticles co-doped with Fe3+ and Eu3+ were prepared by a facile co-precipitation method. The structure and morphology of the as-prepared nanoparticles were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and diffuse reflectance absorption spectra, respectively. The photocatalytic activities of the prepared catalysts were evaluated by photocatalytic degradation of methyl orange in aqueous solution with solar light irradiation. The co-doped Fe3+ and Eu3+ showed a synergistic effect, which significantly increased the photocatalytic activity of ZnO. The influences of calcination time, photocatalytic reaction temperature and catalyst loading on the photocatalytic activity of the catalyst were also investigated. It was found that there were an optimum photocatalytic reaction temperature and an optimum catalyst loading for high photocatalytic efficiency, and the photocatalytic efficiency decreased with increase in calcination time. The results of this study demonstrate that the as-prepared product of Eu3+/Fe3+/ZnO is a promising photocatalyst for solar assisted degradation of organic pollutions.

  9. Installation guidelines for solar heating system, single-family residence at New Castle, Pennsylvania

    Science.gov (United States)

    1980-01-01

    The solar heating system installer guidelines are presented for each subsystem. This single family residential heating system is a solar-assisted, hydronic-to-warm-air system with solar-assisted domestic water heating. It is composed of the following major components: (1) liquid cooled flat plate collectors; (2) water storage tank; (3) passive solar-fired domestic water preheater; (4) electric hot water heater; (5) heat pump with electric backup; (6) solar hot water coil unit; (7) tube-and-shell heat exchanger, three pumps, and associated pipes and valving in an energy transport module; (8) control system; and (9) air-cooled heat purge unit. Information is provided on the operating procedures, controls, caution requirements, and routine and schedule maintenance in the form of written descriptions, schematics, detail drawings, pictures, and manufacturer's component data.

  10. Installation guidelines for Solar Heating System, single-family residence at New Castle, Pennsylvania

    Energy Technology Data Exchange (ETDEWEB)

    1980-01-01

    The Solar Heating System installer guidelines are provided for each subsystem and includes testing and filling the system. This single-family residential heating system is a solar-assisted, hydronic-to-warm-air system with solar-assisted domestic water heating. It is composed of the following major components: liquid cooled flat plate collectors; water storage tank; passive solar-fired domestic water preheater; electric hot water heater; heat pump with electric backup; solar hot water coil unit; tube-and-shell heat exchanger, three pumps, and associated pipes and valving in an energy transport module; control system; and air-cooled heat purge unit. Information is also provided on the operating procedures, controls, caution requirements, and routine and schedule maintenance. Information consists of written procedures, schematics, detail drawings, pictures and manufacturer's component data.

  11. A DDC-based capacity controller of a direct expansion (DX) air conditioning (A/C) unit for simultaneous indoor air temperature and humidity control - Pt. 1: Control algorithms and preliminary controllability tests

    Energy Technology Data Exchange (ETDEWEB)

    Li, Zheng [Institute of Air Conditioning, China Academy of Building Research, Beijing 100013 (China); Deng, Shiming [Department of Building Services Engineering, The Hong Kong Polytechnic University, Kowloon, Hong Kong SAR (China)

    2007-01-15

    For residential buildings located in the subtropics, direct expansion (DX) air conditioning (A/C) units are commonly used. Most DX A/C units are currently equipped with single-speed compressors and supply fans, relying on on-off cycling compressors as a low-cost approach to maintain only indoor air dry-bulb temperature, resulting in either space overcooling or an uncontrolled equilibrium indoor relative humidity (RH) level. With the rapid development of A/C industry, the use of variable-speed compressor and supply fan has become more and more prevalent and practical. This paper, the first part of a two-part series, reports on the development of a novel direct digital control (DDC)-based capacity controller for a DX A/C unit having variable-speed compressor and supply fan to simultaneously control indoor air temperature and RH in a conditioned space served by the DX A/C unit. The controller is the first of its kind as a composite parameter, sensible heat ratio (SHR), is used as a controlled parameter. The core element of the capacity controller, a numerical calculation algorithm (NCA) is firstly presented. This is followed by reporting the results of preliminary controllability tests of the DDC-based capacity controller, which suggested that the controller developed could achieve a reasonable control accuracy, but with room for improvement with respect to control sensitivity. Part II of the two-part series reports on the further development of the controller to improve its control sensitivity, and the results of associated controllability tests. (author)

  12. Comparative evaluation of ground-coupled heat pumps that use solar energy

    Energy Technology Data Exchange (ETDEWEB)

    Andrews, J.W.; Catan, M.A.

    1985-03-01

    A study of combined building space conditioning systems using both solar energy and heat pumps was conducted for the US Department of Energy (DOE). Several of these systems used the ground as a source or storage element for thermal energy, in order to reduce or eliminate the need for backup energy. This paper summarizes the results obtained for these systems in the United States, and describes the relationship of ground-coupling to the overall US solar-assisted heat-pump program.

  13. Installation guidelines for solar heating system, single-family residence at William OBrien State Park, Stillwater, Minnesota

    Science.gov (United States)

    1980-01-01

    Installation procedures for the single family residential solar heating system at the William O'Brien State Park, Stillwater, Minnesota, are presented. The system is a solar-assisted, hydronic-to-warm-air system with solar-assisted domestic water heating. It is composed of the following major components: liquid cooled flat plate collectors; water storage tank; passive solar-fired domestic water preheater; electric hot water heater; heat pump with electric backup; solar hot water coil unit; tube-and-shell heat exchanger, three pumps, and associated pipes and valving in an energy transport module; control system; and air-cooled heat purge unit. Installer guidelines are provided for each subsystem and includes testing and filling the system. Information is also given on the operating procedures, controls, caution requirements and routine and schedule maintenance.

  14. New absorption chiller and control strategy for the solar assisted cooling system at the german federal enviroment agency

    OpenAIRE

    Albers, Jan

    2013-01-01

    Part of: Thermally driven heat pumps for heating and cooling. – Ed.: Annett Kühn – Berlin: Universitätsverlag der TU Berlin, 2013 ISBN 978-3-7983-2686-6 (print) ISBN 978-3-7983-2596-8 (online) urn:nbn:de:kobv:83-opus4-39458 [http://nbn-resolving.de/urn:nbn:de:kobv:83-opus4-39458] Typically the cooling capacity of absorption chillers is controlled by adjusting the driving hot water temperature according to the load. Meanwhile the cooling water temperature is contr...

  15. PV/T太阳能热泵系统的性能研究%Dynamic Performance of PV/T Solar-assisted Heat Pump System

    Institute of Scientific and Technical Information of China (English)

    裴刚; 季杰; 何伟; 孙炜

    2006-01-01

    提出一种新型的太阳能热泵系统--PV/T-SAHP系统,该系统具有光电/光热综合利用的功能;建立了PV/T-SAHP系统的动态模型,对该系统的运行特性进行了数值模拟.结果显示,PV/T-SAHP系统的电效率和热效率较传统的太阳能系统和热泵系统都有明显提高,运行能耗较普通热泵大幅度降低;系统PV/T蒸发器的面积、管间距、倾角等参数的变化对电效率和热性能会产生比较大的影响,是系统优化设计的关键因素.

  16. Solar assisted biogas plants: Pt. 4. Optimum area for blackening and double glazing over a fixed-dome biogas plant

    Energy Technology Data Exchange (ETDEWEB)

    Jayashankar, B.C.; Kishor, J.; Goyal, I.C.; Sawhney, R.L.; Sodha, M.S.

    The economic analysis of a fixed-dome biogas plant of rated capacity 8 m/sup 3/, above which a part of the ground is blackened and doubly glazed in the cold climate of Srinagar is presented. Blackening and glazing of the ground cannot alone maintain the slurry temperature at 35/sup 0/C, which is the optimum temperature in the mesophilic range for the anaerobic digestion of cattle dung, and so a part of the biogas must be burnt. The electrical simulation experiments have been performed to determine the loss or gain of heat from the underground biodigestor to the ambient atmosphere through the ground if a part of the ground above is blackened and double glazed. Economic analysis of the system shows that the optimum area to be blackened and glazed would have a radius 1.5 times that of the biodigestor.

  17. A Variable Refrigerant Flow Heat Pump Computer Model in EnergyPlus

    Energy Technology Data Exchange (ETDEWEB)

    Raustad, Richard A. [Florida Solar Energy Center

    2013-01-01

    This paper provides an overview of the variable refrigerant flow heat pump computer model included with the Department of Energy's EnergyPlusTM whole-building energy simulation software. The mathematical model for a variable refrigerant flow heat pump operating in cooling or heating mode, and a detailed model for the variable refrigerant flow direct-expansion (DX) cooling coil are described in detail.

  18. Solar energy and heat pumps: evaluation of combined systems for heating and cooling of buildings

    Energy Technology Data Exchange (ETDEWEB)

    Andrews, J.W.; Catan, M.A.; Le Doux, P.

    1982-09-01

    An analysis of a broad range of solar assisted heat pump systems was carried out. Systems were divided into three categories on the basis of whether ground coupling was included in the system and, if so, whether solar energy was stored in the ground or used in some other way. In the category of non-ground-coupled systems, an advanced air-source heat pump concept designed to improve capacity and coefficient of performance at low source temperatures was used as the basis for a dual source heat pump. For ground coupled systems which do not store solar heat in the ground, three options were considered: use of simple passive techniques to reduce the effective heating load; use of photovoltaics to drive the heat pump compressor; and use of active solar components as a source to the heat pump, for direct space heating, or for domestic hot water only. For systems which do store solar energy in the ground, the minimum size for efficient thermal carryover from summer to winter was determined to be a system capable of serving approx. 100 houses. Use of a fuel-fired heat pump is also an advantage in these larger systems. Economic analyses were based on a maximum allowable payback of 8 years for residential systems. For the large-scale system, a simplified 10-year life-cycle costing was employed.

  19. 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.

  20. West Chester Work Center Solar Space Heating Demonstration Project. Final technical progress report

    Energy Technology Data Exchange (ETDEWEB)

    1979-08-01

    An integrated system is described providing solar energy space heating for a 9982 sq ft, newly built, one-story building. Functionally, the building consists of two sections: an office and a storeroom. The office section is heated by solar-assisted water-to-air heat pump units. The storeroom section is heated by an air-handling unit, containing a water-to-air coil. The system design was based on solar energy providing 62% of the heating load, with the balance to be supplied by heat pump power and a back-up electric boiler. The system includes 1900 active (2112 gross) square feet of flat-plate solar collectors, and a 6000 gallon above-ground indoor storage tank. Freeze protection is provided by a gravity drain-down scheme combined with nitrogen pressurization in a closed circuit.

  1. 太阳能辅助碳捕集:适用技术、性能比较和发展趋势%Solar-assisted carbon capture:technology,performance comparison and development trend

    Institute of Scientific and Technical Information of China (English)

    赵睿恺; 邓帅; 赵力; 刘一楠; 何俊南

    2016-01-01

    Solar-assisted carbon capture,which integrates three technologies of energy efficient, renewable energy utilization,CO2 capture together,is a reasonable solution to mitigate the challenge of climate change. The research status of solar-assisted carbon capture of post-combustion, pre-combustion and oxygen-combustion is summarized in terms of separation method and technology, etc. Then separation processes of different technologies are evaluated using ideal minimum separation work and thermodynamic separation efficiency. Finally,several potential directions of solar-assisted carbon capture in the future may be the basic theory of energy efficiency,highly-efficient integration and cascade utilization. The separation model would not fit to the second generation technologies and the framework of carbon capture would be expanded. Solar-assisted links would be added as well from carbon capture to transportation and storage. Cascade utilization of solar-assisted carbon capture would become more flexible.%太阳能辅助碳捕集系统集合了提高能源转换效率、使用可再生能源和二氧化碳捕集与封存3种应对气候变化挑战的技术,是跨学科研究中的新兴领域。本文综述了燃烧后、燃烧前和富氧燃烧碳捕集技术中太阳能辅助碳捕集的研究现状,并从分离方式、分离技术和太阳能辅助方式等方面进行了深入分析。其后从分离理想最小功和分离热力学效率对不同二氧化碳的分离技术进行了性能评价。最后对太阳能辅助碳捕集技术的发展趋势进行了梳理,分离模型方法不再适合光催化等第二代碳捕集技术,碳捕集理论研究的框架有待拓展;太阳能辅助环节将从碳捕集过程逐步扩展到运输和储存过程;太阳能辅助形式中的梯级利用更加灵活多样。该新兴技术在能效基础理论、太阳能梯级利用和高效集成三方面亟待突破。

  2. Seasonal heat storage in underground caverns. Final report; Saisonale Waermespeicherung in Grubenraeumen. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Eikmeier, B.; Mohr, M.; Unger, H.

    1999-11-01

    The solar assisted heat supply of buildings can provide an important contribution in order to achieve the targets of minimization of primary energy consumption and reduction of greenhouse gas emissions. However, the problem of the seasonal divergence between the high solar energy supply in the summer and the high demand in the winter consists; therefore seasonal heat storage is indispensable. Here, a considerable fraction of the investments must be addressed to the central reservoir. An approach towards the reduction of the investment costs for the installation of seasonal storages in the use of cavities, which are already available in mines. In the Ruhr-Area a complex net of subterranean cavities is available. For the cost estimation of solar assisted heat supply with integrated storage in mines, the reference suburban colony 'Essen-Stoppenberg' with 42 double family houses is chosen. The specific storage costs are estimated for different technical options (tunnel- or shaft storage, direct or indirect charging system). In most cases these costs are comparable to other seasonal heat storage projects. With advantageous conditions specific capital expenditures can be achieved, which are lower than those of conventional seasonal storage. However, it must be considered, that the operating costs of pit storages are expected to be higher. (orig.)

  3. Solar heating and cooling system installed at Leavenworth, Kansas

    Science.gov (United States)

    1980-01-01

    A solar heating and cooling is described which is designed to furnish 90 percent of the overall heating load, 70 percent of the cooling load and 100 percent of the domestic hot water load. The building has two floors with a total of 12,000 square feet gross area. The system has 120 flat-plate liquid solar panels with a net area of 2,200 square feet. Five 3 ton Arkla solar assisted absorption units provide the cooling, in conjunction with a 3,000 gallon chilled water storage tank. Two 3,000 gallon storage tanks are provided with one designated for summer use, whereas both tanks are utilized during winter.

  4. A Process Heat Application Using Parabolic Trough Collector

    Science.gov (United States)

    Yılmaz, İbrahim Halil; Söylemez, Mehmet Sait; Hayta, Hakan; Yumrutaş, Recep

    A pilot study has been performed based on a heat process application that is designed, installed and tested at Gaziantep University to establish the technical and economic feasibility of high temperature solar-assisted cooking process. The system has been designed to be satisfying the process conditions integrated with parabolic trough solar collector (PTSC). It is primarily consists of the PTSC array, auxiliary heater, plate type heat exchanger, cooking system and water heating tanks. In the operation of the process heat application, the energy required to cook wheat (used as cooking material) has been supplied from solar energy which is transferred to heat transfer fluid (HTF) by heat exchanging units and finally discharged to water in order to produce bulgur. The performance parameters of the sub-systems and the process compatibility have been accomplished depending on the system operation. In addition that the system performance of the high temperature solar heat process has been presented and the recommendations on its improvement have been evaluated by performing an experimental study. As a result that the use of solar energy in process heat application has been projected and its contribution to economics view with respect to conventional cooking systems has been conducted.

  5. Optimization of Serial Combined System of Ground-Coupled Heat Pump and Solar Collector

    Institute of Scientific and Technical Information of China (English)

    ZHAO Jun; CHEN Yan; LU Suzhen; CUI Junkui

    2009-01-01

    A mathematical optimization model was set up for a ground-solar combined system based on in-situ experimental results,in which the solar collector was combined serially with a ground-coupled heat pump(GCHP).The universal optimal equations were solved by the constrained variable metric method considering both the performance and economics.Then the model was applied to a specific case concerning an actual solar assisted GCHP system for space heating.The results indicated a system coefficient of performance(COP)of 3.9 for the optimal method under the seriaI heating mode,and 3.2 for the conventional one.In addition,the optimum solution also showed advantages in energy and cost saving.1eading to a 16.7%improvement in the heat pump performance at 17.2%less energy consumption and 11.8%lower annual cost,respectively.

  6. Brookhaven solar-heat-pump simulator: technical description and experimental results

    Energy Technology Data Exchange (ETDEWEB)

    Catan, M.

    1982-07-01

    The series solar-assisted heat pump (SAHP) system has the potential to deliver heat with very high seasonal coefficients of performance (coefficient of performance or COP is the ratio of useful heat delivered to electrical power consumed). This potential rests on the ability of the heat-pump component to use the high source temperatures available from the solar-collector component to deliver heat with a COP which rises monotonically with source temperature. The Brookhaven National Laboratory (BNL) Heat Pump Simulator has played an important role in a program aimed at demonstrating the feasibility of building simple potentially inexpensive heat pumps for use in SAHP systems. Basically the work described here consists of the following: (1) The construction and testing of a laboratory heat pump built from conventional components and characterized by a very desirable COP versus source temperature profile. (2) The testing of two prototype SAHPs built by heat-pump manufacturers under contract to DOE. (3) Detailed component and control tests aimed at establishing improvements in the SAHP prototypes. The paper describes, in some detail, the BNL Heat Pump Simulator, a versatile instrument used to test heat pumps and heat-pump subcomponents under transient and steady-state conditions.

  7. Energy Performance Comparison of Heating and Air Conditioning Systems for Multi-Family Residential Buildings

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Weimin; Zhang, Jian; Jiang, Wei; Liu, Bing

    2011-07-31

    The type of heating, ventilation and air conditioning (HVAC) system has a large impact on the heating and cooling energy consumption in multifamily residential buildings. This paper compares the energy performance of three HVAC systems: a direct expansion (DX) split system, a split air source heat pump (ASHP) system, and a closed-loop water source heat pump (WSHP) system with a boiler and an evaporative fluid cooler as the central heating and cooling source. All three systems use gas furnace for heating or heating backup. The comparison is made in a number of scenarios including different climate conditions, system operation schemes and applicable building codes. It is found that with the minimum code-compliant equipment efficiency, ASHP performs the best among all scenarios except in extremely code climates. WSHP tends to perform better than the split DX system in cold climates but worse in hot climates.

  8. Status seminar `98: Solar-supported district heating with seasonal heat storage. Status report `98; Status-Seminar `98: Solarunterstuetzte Nahwaermeversorgung - Saisonale Waermespeicherung. Statusbericht `98

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-12-31

    This status report refers to the BMBF (Federal Ministry for Education, Science, Research and Technology) status seminar: Solar-assisted district heat supply - seasonal heat storage that took place in Neckarsulm on 19th and 20th May. 1998. The report contains the reference papers and the status reports of all projects supported under the Ministry`s SOLARTHERMIE programme that have already been finished or are still running. (orig.) [Deutsch] Der vorliegende Statusbericht wird anlaesslich des BMBF-Statusseminars: Solarunterstuetzte Nahwaermeversorgung - Saisonale Waermespeicherung am 19. und 20. Mai 1998 in Neckarsulm herausgegeben. Der Bericht enthaelt neben den Tagungsbeitraegen auch die Sachstandsberichte aller Projekte, die zu diesem Thema in den letzten Jahren von BMBF in dem Programm SOLARTHERMIE-2000 bereits abgeschlossen wurden oder z.Zt. gefoerdert werden. (orig.)

  9. Performance of a solar energy-assisted heat pump heating system: analysis and correlation of field-collected data

    Energy Technology Data Exchange (ETDEWEB)

    Williams, R.C.

    1979-08-01

    An analysis of building energy usage and thermal load for the Solar Building during the winter heating seasons of 1974-75 and 1975-76 is reported. The one-story office building is located in Albuquerque, New Mexico. Its mechanical heating and cooling equipment is categorized as a solar-assisted heat pump system consisting of solar collectors, water thermal storage, a water-to-water heat pump and five smaller water-to-air heat pump packaged units. Building energy usage was examined with emphasis on the time of day energy was consumed and the source from which the energy was obtained; i.e., from the electricity for lighting, office equipment and mechanical equipment, and from the heat output of the thermal storage and heat pumps. The rate of electrical energy consumption was found to be very dependent on building use. High rates of electrical energy usage during occupied periods required cooling during parts of even the coldest days. Mechanical equipment heating was found to vary as a function of building usage as well as a function of the indoor-outdoor temperature differential. Energies supplied to and withdrawn from the building were examined and are presented for hourly, daily, and seasonal periods. A comparison of the two heating seasons was made. Energy losses and gains from the building to the surroundings were examined for both steady-state and transient load profiles. Envelope conductive heat losses and losses due to infiltration and ventilation were calculated using actual weather data through the use of the Building Environmental Analysis Program (BEAP). The effect of building thermal storage on heating and cooling loads was examined and a set of building balance-point temperatures was established. Comparisons between the building energy consumption and a calculated load were made for hourly, daily, and seasonal periods.

  10. Heat Waves

    Science.gov (United States)

    Heat Waves Dangers we face during periods of very high temperatures include: Heat cramps: These are muscular pains and ... having trouble with the heat. If a heat wave is predicted or happening… - Slow down. Avoid strenuous ...

  11. Heat Islands

    Science.gov (United States)

    EPA's Heat Island Effect Site provides information on heat islands, their impacts, mitigation strategies, related research, a directory of heat island reduction initiatives in U.S. communities, and EPA's Heat Island Reduction Program.

  12. Comfortable, high-efficiency heat pump with desiccant-coated, water-sorbing heat exchangers

    Science.gov (United States)

    Tu, Y. D.; Wang, R. Z.; Ge, T. S.; Zheng, X.

    2017-01-01

    Comfortable, efficient, and affordable heating, ventilation, and air conditioning systems in buildings are highly desirable due to the demands of energy efficiency and environmental friendliness. Traditional vapor-compression air conditioners exhibit a lower coefficient of performance (COP) (typically 2.8-3.8) owing to the cooling-based dehumidification methods that handle both sensible and latent loads together. Temperature- and humidity-independent control or desiccant systems have been proposed to overcome these challenges; however, the COP of current desiccant systems is quite small and additional heat sources are usually needed. Here, we report on a desiccant-enhanced, direct expansion heat pump based on a water-sorbing heat exchanger with a desiccant coating that exhibits an ultrahigh COP value of more than 7 without sacrificing any comfort or compactness. The pump’s efficiency is doubled compared to that of pumps currently used in conventional room air conditioners, which is a revolutionary HVAC breakthrough. Our proposed water-sorbing heat exchanger can independently handle sensible and latent loads at the same time. The desiccants adsorb moisture almost isothermally and can be regenerated by condensation heat. This new approach opens up the possibility of achieving ultrahigh efficiency for a broad range of temperature- and humidity-control applications.

  13. Comfortable, high-efficiency heat pump with desiccant-coated, water-sorbing heat exchangers

    Science.gov (United States)

    Tu, Y. D.; Wang, R. Z.; Ge, T. S.; Zheng, X.

    2017-01-01

    Comfortable, efficient, and affordable heating, ventilation, and air conditioning systems in buildings are highly desirable due to the demands of energy efficiency and environmental friendliness. Traditional vapor-compression air conditioners exhibit a lower coefficient of performance (COP) (typically 2.8–3.8) owing to the cooling-based dehumidification methods that handle both sensible and latent loads together. Temperature- and humidity-independent control or desiccant systems have been proposed to overcome these challenges; however, the COP of current desiccant systems is quite small and additional heat sources are usually needed. Here, we report on a desiccant-enhanced, direct expansion heat pump based on a water-sorbing heat exchanger with a desiccant coating that exhibits an ultrahigh COP value of more than 7 without sacrificing any comfort or compactness. The pump’s efficiency is doubled compared to that of pumps currently used in conventional room air conditioners, which is a revolutionary HVAC breakthrough. Our proposed water-sorbing heat exchanger can independently handle sensible and latent loads at the same time. The desiccants adsorb moisture almost isothermally and can be regenerated by condensation heat. This new approach opens up the possibility of achieving ultrahigh efficiency for a broad range of temperature- and humidity-control applications. PMID:28079171

  14. Comfortable, high-efficiency heat pump with desiccant-coated, water-sorbing heat exchangers.

    Science.gov (United States)

    Tu, Y D; Wang, R Z; Ge, T S; Zheng, X

    2017-01-12

    Comfortable, efficient, and affordable heating, ventilation, and air conditioning systems in buildings are highly desirable due to the demands of energy efficiency and environmental friendliness. Traditional vapor-compression air conditioners exhibit a lower coefficient of performance (COP) (typically 2.8-3.8) owing to the cooling-based dehumidification methods that handle both sensible and latent loads together. Temperature- and humidity-independent control or desiccant systems have been proposed to overcome these challenges; however, the COP of current desiccant systems is quite small and additional heat sources are usually needed. Here, we report on a desiccant-enhanced, direct expansion heat pump based on a water-sorbing heat exchanger with a desiccant coating that exhibits an ultrahigh COP value of more than 7 without sacrificing any comfort or compactness. The pump's efficiency is doubled compared to that of pumps currently used in conventional room air conditioners, which is a revolutionary HVAC breakthrough. Our proposed water-sorbing heat exchanger can independently handle sensible and latent loads at the same time. The desiccants adsorb moisture almost isothermally and can be regenerated by condensation heat. This new approach opens up the possibility of achieving ultrahigh efficiency for a broad range of temperature- and humidity-control applications.

  15. Solar heating cooling. Preparation of possible participation in IEA, Solar Heating Cooling Task 25; Solvarmedrevet koeling. Forberedelse af evt. deltagelse i IEA, Solar Heating Cooling Task 25

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-03-01

    For the Danish solar heating industries it is interesting to discuss the domestic market possibilities and the export possibilities for solar heating cooling systems. The Danish solar heating sector also wants to participate in the international collaboration within IEA Solar Heating and Cooling Task 25 'Solar Assisted Air Conditioning of Buildings'. The Danish Energy Agency therefore has granted means for this project to discuss: The price of cooling for 3 different solar cooling methods (absorption cooling, desiccant cooling and ejector cooling); Market possibilities in Denmark and abroad; The advantages by Danish participation in IEA Task 25. The task has been solved through literature studies to establish status for the 3 technologies. It turned out that ejector cooling by low temperatures (85 deg. C from the solar collector) exists as pilot plants in relation to district heating, but is still not commercial accessible. Desiccant cooling, where the supplied heat has temperatures down to 55 deg. C is a well-developed technology. However only a handful of pilot plants with solar heating exists, and thus optimization relating to operation strategy and economy is on the experimental stage. Absorption cooling plants driven by solar heating are found in a large number in Japan and are also demonstrated in several other countries. The combination of absorption heating pump and solar heating is considered to be commercial accessible. Solar heating is interesting as heat source of to the exent that it can replace other sources of heat without the economy being depreciated. This can be the case in South Europe if: 1) oil or natural gas is used for heating; 2) a solar heating system already exists, e.g. for domestic water supply, and is installed so that the marginal costs by solar heating supply of the ventilation plant is reduced. All in all the above conditions mean that the market for solar heating for cooling is very limited in Europe, where almost

  16. Study on the Performance of a Ground Source Heat Pump System Assisted by Solar Thermal Storage

    Directory of Open Access Journals (Sweden)

    Yu Jin Nam

    2015-11-01

    Full Text Available A ground source heat pump system (GSHPS utilizes a relatively stable underground temperature to achieve energy-saving for heating and cooling in buildings. However, continuous long-term operation will reduce the soil temperature in winter, resulting in a decline in system performance. In this research, in order to improve the system performance of a GSHPS, a ground heat pump system integrated with solar thermal storage was developed. This solar-assisted ground heat pump system (SAGHPS can both maintain the balance of the soil temperature effectively and achieve higher system performance than the conventional system. In this paper, in order to examine the characteristics of the system, a dynamic simulation was conducted under various conditions. The results of our case study provide specific operation data such as heat exchange rate, heat source temperature, and heat pump COP. As a result, the heat pump COP of SAGHPS was 4.7%, 9.3% higher than that of the GSHPS.

  17. Heat Stress

    Science.gov (United States)

    ... Publications and Products Programs Contact NIOSH NIOSH HEAT STRESS Recommend on Facebook Tweet Share Compartir NEW OSHA- ... hot environments may be at risk of heat stress. Exposure to extreme heat can result in occupational ...

  18. Heating automation

    OpenAIRE

    Tomažič, Tomaž

    2013-01-01

    This degree paper presents usage and operation of peripheral devices with microcontroller for heating automation. The main goal is to make a quality system control for heating three house floors and with that, increase efficiency of heating devices and lower heating expenses. Heat pump, furnace, boiler pump, two floor-heating pumps and two radiator pumps need to be controlled by this system. For work, we have chosen a development kit stm32f4 - discovery with five temperature sensors, LCD disp...

  19. Heat pumps

    CERN Document Server

    Macmichael, DBA

    1988-01-01

    A fully revised and extended account of the design, manufacture and use of heat pumps in both industrial and domestic applications. Topics covered include a detailed description of the various heat pump cycles, the components of a heat pump system - drive, compressor, heat exchangers etc., and the more practical considerations to be taken into account in their selection.

  20. Solar short-distance heat. State of projects in Germany; Solare Nahwaerme. Stand der Projekte in Deutschland

    Energy Technology Data Exchange (ETDEWEB)

    Fisch, M.N. [Technische Univ. Braunschweig (Germany). Inst. fuer Gebaeude- und Solartechnik, Inter-Governmental Maritime Consultative Organization, Steinbeis Transferzentrum Energie-, Gebaeude- und Solartechnik (STZ-EGS), Stuttgart (Germany)

    1999-10-01

    After the successful testing of smaller solar-assisted short-distance heat projects during the first half of the 90s in Germany (e.g., Ravensburg, Koengen, Neckarsulm, Schwaebisch-Gmuend), the first large-scale solar plants with long-term thermal energy stores went operational in Hamburg and Friedrichshafen in late 1996. So, a goal was attained that had seemed Utopian for many years: to heat buildings in winter with solar energy stored during summer. (orig.) [Deutsch] Nach der erfolgreichen Erprobung von kleineren solarunterstuetzten Nahwaermeprojekten in der ersten Haelfte der neunziger Jahre in Deutschland (z.B. Ravensburg, Koengen, Neckarsulm, Schwaebisch-Gmuend) gingen Ende 1996 in Hamburg und Friedrichshafen die ersten solaren Grossanlagen mit Langzeit-Waermespeicher in Betrieb. Damit wurde ein Ziel erreicht, das ueber viele Jahre hinweg utopisch erschienen war - mit der Sonnenenergie aus dem Sommer im Winter die Gebaeude zu beheizen. (orig.)

  1. Heating System of High Temperature Biogas Digester by Solar Energy and Methane Liquid Heat Recovery Heat Pump%太阳能-沼液余热式热泵高温厌氧发酵加温系统

    Institute of Scientific and Technical Information of China (English)

    裴晓梅; 石惠娴; 朱洪光; 龙惟定

    2012-01-01

    A heating system of biogas digester was developed to avoid area limitations of buried wells in the heating system of biogas digester by ground-source heat pump, in which the heat energy was supplied by hot water from waste heat recovery coupled with solar- assisted heat pump. The key parameters such as the heat load of digester, waste heat recovery rate of the methane liquid, medium and high heat pump, the solar energy collector area and so on werecalculated. The results show that this system can guarantee the temperature of 50+2℃ in the digester, the heat recovery rate of the methane liquid can reach upto 70%. The system is characterized by that the solar energy and waste heat recovery of the methane liquid serve as the low-graded heat sources of the heat pump. There a're three kinds of running modes including the sloar energy heating directly, the solar energy low level heat sources heat pump, and the combination of the solar energy and waste heat recovery low - graded heat resources heat pump and so on. The waste heat recovery technique can make full use of energy of the system and prevent thermal pollution.%针对地源热泵式沼气池加温系统需要打地埋井及铺设地埋管受地质水质局限等问题,系统构建了太阳能—沼液余热式热泵高温厌氧发酵加温系统.对系统发酵池热负荷、沼液余热回收率、中高温热泵机组、太阳能集热装置等关键参数进行了理论计算,得出系统能够保证发酵池温度50±2℃,沼液余热回收量可以达到系统总需要热量的70%.系统特点在于采用太阳能和沼液余热联合作为中高温热泵低位热源并确立其三种运行模式,包括太阳能直接加温模式,太阳能低位热源—热泵加热模式和太阳能—沼液余热回收联合式热泵加温模式.

  2. How to Ensure Long -term Stable Operation of Ground Source Heat Pump System for Heating Biogas Digester%如何保证地源热泵式沼气池加温系统长期稳定运行

    Institute of Scientific and Technical Information of China (English)

    张迪; 石惠娴; 朱洪光; 雷勇; 王卓

    2011-01-01

    针对地源热泵式沼气池加温系统中出现的冬夏季取排热不平衡从而影响其长期稳定运行的问题,本文在采取控制运行方式、增加辅助热源和蓄热系统解决方法的分析基础上,从充分利用可再生能源和地源热泵设备的角度出发,提出热泵供热和制冷互补模式与太阳能-地源热泵多功能互补模式,并对其可行性进行分析.%To address the problem of heat imbalance of soil between winter and summer led by ground source heat pump system for heating biogas digester and to ensure the system running more stably, effectively in a long time , the paper presents the advantages and disadvantages of controlling operation model and solar assisted ground source heat pump system with heat storage.What's more, the paper also proposes complementary models of heafing and cooling of heat pump and multifunctional system integrationg solar energy with ground source heat pump, and analyses the possibility of the above two solutions from the perspective of making full use of renewable energy and the equipment of ground soure heat pump.

  3. Heat pumps

    CERN Document Server

    Brodowicz, Kazimierz; Wyszynski, M L; Wyszynski

    2013-01-01

    Heat pumps and related technology are in widespread use in industrial processes and installations. This book presents a unified, comprehensive and systematic treatment of the design and operation of both compression and sorption heat pumps. Heat pump thermodynamics, the choice of working fluid and the characteristics of low temperature heat sources and their application to heat pumps are covered in detail.Economic aspects are discussed and the extensive use of the exergy concept in evaluating performance of heat pumps is a unique feature of the book. The thermodynamic and chemical properties o

  4. HEAT RECUPERATION

    Directory of Open Access Journals (Sweden)

    S. L. Rovin

    2011-01-01

    Full Text Available Heat recovery is an effective method of shortening specific energy consumption. new constructions of recuperators for heating and cupola furnaces have been designed and successfully introduced. two-stage recuperator with computer control providing blast heating up to 600 °C and reducing fuel consumption by 30% is of special interest.

  5. Heat exchanger

    Energy Technology Data Exchange (ETDEWEB)

    Craig, L.B.; Farma, A.J.

    1987-01-06

    This invention concerns a heat exchanger as used in a space heater, of the type in which hot exhaust gases transfer heat to water or the like flowing through a helical heat exchange coil. A significant improvement to the efficiency of the heat exchange occurring between the air and water is achieved by using a conduit for the water having external helical fluting such that the hot gases circulate along two paths, rather than only one. A preferred embodiment of such a heat exchanger includes a porous combustion element for producing radiant heat from a combustible gas, surrounded by a helical coil for effectively transferring the heat in the exhaust gas, flowing radially from the combustion element, to the water flowing through the coil. 4 figs.

  6. Composite ground source heat pump used in scattered oilfield%复合地源热泵在油田边零井中的应用

    Institute of Scientific and Technical Information of China (English)

    刘伟; 杨鹏; 侯静

    2012-01-01

    In the Remote areas, oil is stored in storage tanks, and needed to be heated in order to output. Compared with fuel, gas boilers and electric heating system, ground source heat pump heating system has the features as safe, energy saving, environmentally friendly. But a separate ground source heat pump sys- tem only take the heat from soil, not release heat to the soil. To overcome this shortcoming the paper pro- poses solar--assisted ground-source heat pump system. Through the use of trnsys software simulation, it is proved that this system is feasible, and should be promoted.%油田边零井中的原油储存在储油罐中,需要加热才能输出,地源热泵加热系统较燃油、燃气锅炉和电加热系统,具有安全,节能,环保的特点,但是单独地源热泵系统地下地埋管只取热不放热,为了克服这个缺点,提出了太阳能辅助地源热泵系统,通过运用trnsys软件模拟,证明此系统用于油田边零井是可行的,值得推广的。

  7. Heat pipes

    CERN Document Server

    Dunn, Peter D

    1994-01-01

    It is approximately 10 years since the Third Edition of Heat Pipes was published and the text is now established as the standard work on the subject. This new edition has been extensively updated, with revisions to most chapters. The introduction of new working fluids and extended life test data have been taken into account in chapter 3. A number of new types of heat pipes have become popular, and others have proved less effective. This is reflected in the contents of chapter 5. Heat pipes are employed in a wide range of applications, including electronics cooling, diecasting and injection mo

  8. Magnetar heating

    CERN Document Server

    Beloborodov, Andrei M

    2016-01-01

    We examine four candidate mechanisms that could explain the high surface temperatures of magnetars. (1) Heat flux from the liquid core heated by ambipolar diffusion. It could sustain the observed surface luminosity $L_s\\approx 10^{35}$ erg s$^{-1}$ if core heating offsets neutrino cooling at a temperature $T_{\\rm core}>6\\times 10^8$ K. This scenario is viable if the core magnetic field exceeds $10^{16}$ G, the magnetar has mass $M10^{16}$ G varying on a 100 meter scale could provide $L_s\\approx 10^{35}$ erg s$^{-1}$. (4) Bombardment of the stellar surface by particles accelerated in the magnetosphere. This mechanism produces hot spots on magnetars. Observations of transient magnetars show evidence for external heating.

  9. Heat emergencies

    Science.gov (United States)

    ... death. The early symptoms of heat cramps include: Muscle cramps and pains that most often occur in the ... do if salt beverages are not available. For muscle cramps , give beverages as noted above and massage affected ...

  10. Heat transfer

    CERN Document Server

    Holman, J P

    2010-01-01

    As one of the most popular heat transfer texts, Jack Holman's "Heat Transfer" is noted for its clarity, accessible approach, and inclusion of many examples and problem sets. The new tenth edition retains the straight-forward, to-the-point writing style while covering both analytical and empirical approaches to the subject. Throughout the book, emphasis is placed on physical understanding while, at the same time, relying on meaningful experimental data in those situations that do not permit a simple analytical solution. New examples and templates provide students with updated resources for computer-numerical solutions.

  11. Heat-Related Illnesses

    Medline Plus

    Full Text Available ... for signs of heat stroke or exhaustion. Heat Stroke and Exhaustion Symptoms of early heat exhaustion symptoms ... heavy sweating; nausea; and giddiness. Symptoms of heat stroke (late stage of heat illness) include flushed, hot, ...

  12. Heat-Related Illnesses

    Medline Plus

    Full Text Available ... for signs of heat stroke or exhaustion. Heat Stroke and Exhaustion Symptoms of early heat exhaustion symptoms ... heavy sweating; nausea; and giddiness. Symptoms of heat stroke (late stage of heat illness) include flushed, hot, ...

  13. Infrared heating

    Science.gov (United States)

    IR heating was first industrially used in the 1930s for automotive curing applications and rapidly became a widely applied technology in the manufacturing industry. Contrarily, a slower pace in the development of IR technologies for processing foods and agricultural products was observed, due to lim...

  14. IEA Annex 26: Advanced Supermarket Refrigeration/Heat Recovery Systems

    Energy Technology Data Exchange (ETDEWEB)

    Baxter, VAN

    2003-05-19

    has its own refrigeration unit; low-charge direct expansion--similar to conventional multiplex refrigeration systems but with improved controls to limit charge. Means to integrate store HVAC systems for space heating/cooling with the refrigeration system have been investigated as well. One approach is to use heat pumps to recover refrigeration waste heat and raise it to a sufficient level to provide for store heating needs. Another involves use of combined heating and power (CHP) or combined cooling, heating, and power (CCHP) systems to integrate the refrigeration, HVAC, and power services in stores. Other methods including direct recovery of refrigeration reject heat for space and water heating have also been examined.

  15. Heat Related Illnesses

    Institute of Scientific and Technical Information of China (English)

    Robert Carter III; Samuel N. Cheuvront; Michael N. Sawka

    2007-01-01

    @@ KEY POINTS · Heat illnesses range in severity from mild (heat rash, heat syncope, cramps) to serious (heat exhaustion, heat injury, heat stroke). · Although heat illness can occur in anyone, an increased risk is associated with a variety of environmental factors, personal characteristics,health conditions, and medications.

  16. Geothermal district heating systems

    Science.gov (United States)

    Budney, G. S.; Childs, F.

    1982-06-01

    Ten district heating demonstration projects and their present status are described. The projects are Klamath County YMCA, Susanville District Heating, Klamath Falls District Heating, Reno Salem Plaza Condominium, El Centro Community Center Heating/Cooling, Haakon School and Business District Heating, St. Mary's Hospital, Diamond Ring Ranch, Pagosa Springs District Heating, and Boise District Heating.

  17. Solar heating and cooling system installed at Leavenworth, Kansas. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Perkins, R. M.

    1980-06-01

    The solar heating and cooling system installed at the headquarters of Citizens Mutual Savings Association in Leavenworth, Kansas, is described in detail. The project is part of the U.S. Department of Energy's solar demonstration program and became operational in March, 1979. The designer was TEC, Inc. Consulting Engineers, Kansas City, Missouri and contractor was Norris Brothers, Inc., Lawrence, Kansas. The solar system is expected to furnish 90 percent of the overall heating load, 70 percent of the cooling load and 100 percent of the domestic hot water load. The building has two floors with a total of 12,000 square feet gross area. The system has 120 flat-plate liquid solar panels with a net area of 2200 square feet. Five, 3-ton Arkla solar assisted absorption units provide the cooling, in conjunction with a 3000 gallon chilled water storage tank. Two, 3000 gallon storage tanks are provided with one designated for summer use, whereas both tanks are utilized during winter.

  18. Heating systems for heating subsurface formations

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Scott Vinh (Houston, TX); Vinegar, Harold J. (Bellaire, TX)

    2011-04-26

    Methods and systems for heating a subsurface formation are described herein. A heating system for a subsurface formation includes a sealed conduit positioned in an opening in the formation and a heat source. The sealed conduit includes a heat transfer fluid. The heat source provides heat to a portion of the sealed conduit to change phase of the heat transfer fluid from a liquid to a vapor. The vapor in the sealed conduit rises in the sealed conduit, condenses to transfer heat to the formation and returns to the conduit portion as a liquid.

  19. Hydride heat pump with heat regenerator

    Science.gov (United States)

    Jones, Jack A. (Inventor)

    1991-01-01

    A regenerative hydride heat pump process and system is provided which can regenerate a high percentage of the sensible heat of the system. A series of at least four canisters containing a lower temperature performing hydride and a series of at least four canisters containing a higher temperature performing hydride is provided. Each canister contains a heat conductive passageway through which a heat transfer fluid is circulated so that sensible heat is regenerated. The process and system are useful for air conditioning rooms, providing room heat in the winter or for hot water heating throughout the year, and, in general, for pumping heat from a lower temperature to a higher temperature.

  20. Heat transfer

    CERN Document Server

    Jorge, Kubie; Thomas, Grassie

    2012-01-01

    A core task of engineers is to analyse energy related problems. The analytical treatment is usually based on principles of thermodynamics, fluid mechanics and heat transfer, but is increasingly being handled computationally.This unique resource presents a practical textbook, written for both undergraduates and professionals, with a series of over 60 computer workbooks on an accompanying CD.The book emphasizes how complex problems can be deconstructed into a series of simple steps. All thermophysical property computations are illustrated using diagrams within text and on the compani

  1. Heat pipes

    CERN Document Server

    Dunn, Peter D

    1982-01-01

    A comprehensive, up-to-date coverage of the theory, design and manufacture of heat pipes and their applications. This latest edition has been thoroughly revised, up-dated and expanded to give an in-depth coverage of the new developments in the field. Significant new material has been added to all the chapters and the applications section has been totally rewritten to ensure that topical and important applications are appropriately emphasised. The bibliography has been considerably enlarged to incorporate much valuable new information. Thus readers of the previous edition, which has established

  2. Low temperature nuclear heat

    Energy Technology Data Exchange (ETDEWEB)

    Kotakorpi, J.; Tarjanne, R. (comps.)

    1977-08-01

    The meeting was concerned with the use of low grade nuclear heat for district heating, desalination, process heat, and agriculture and aquaculture. The sessions covered applications and demand, heat sources, and economics.

  3. Regenerative Hydride Heat Pump

    Science.gov (United States)

    Jones, Jack A.

    1992-01-01

    Hydride heat pump features regenerative heating and single circulation loop. Counterflow heat exchangers accommodate different temperatures of FeTi and LaNi4.7Al0.3 subloops. Heating scheme increases efficiency.

  4. Heat-Related Illnesses

    Medline Plus

    Full Text Available ... Emergencies A-Z Share this! Home » Emergency 101 Heat-Related Illnesses Dr. Glenn Mitchell , Emergency physician at ... about heat cramps and heat stroke and exhaustion. Heat Cramps Symptoms include muscle spasms, usually in the ...

  5. Regenerative Hydride Heat Pump

    Science.gov (United States)

    Jones, Jack A.

    1992-01-01

    Hydride heat pump features regenerative heating and single circulation loop. Counterflow heat exchangers accommodate different temperatures of FeTi and LaNi4.7Al0.3 subloops. Heating scheme increases efficiency.

  6. Heat pipe thermosyphon heat performance calculation

    Science.gov (United States)

    Novomestský, Marcel; Kapjor, Andrej; Papučík, Štefan; Siažik, Ján

    2016-06-01

    In this article the heat performance of the heat pipe thermosiphon is achieved through numerical model. The heat performance is calculated from few simplified equations which depends on the working fluid and geometry. Also the thermal conductivity is good to mentioning, because is really interesting how big differences are between heat pipes and full solid surfaces.

  7. Segmented heat exchanger

    Science.gov (United States)

    Baldwin, Darryl Dean; Willi, Martin Leo; Fiveland, Scott Byron; Timmons, Kristine Ann

    2010-12-14

    A segmented heat exchanger system for transferring heat energy from an exhaust fluid to a working fluid. The heat exchanger system may include a first heat exchanger for receiving incoming working fluid and the exhaust fluid. The working fluid and exhaust fluid may travel through at least a portion of the first heat exchanger in a parallel flow configuration. In addition, the heat exchanger system may include a second heat exchanger for receiving working fluid from the first heat exchanger and exhaust fluid from a third heat exchanger. The working fluid and exhaust fluid may travel through at least a portion of the second heat exchanger in a counter flow configuration. Furthermore, the heat exchanger system may include a third heat exchanger for receiving working fluid from the second heat exchanger and exhaust fluid from the first heat exchanger. The working fluid and exhaust fluid may travel through at least a portion of the third heat exchanger in a parallel flow configuration.

  8. 空气源热泵在学生公寓的热水改造工程中的应用%Application of Air Source Heat Pump Water Heater to Reconstruction Project of Domestic Hot Water in Student Apartment

    Institute of Scientific and Technical Information of China (English)

    何绪春

    2012-01-01

    The domestic water-heating system with gas-fired boiler of a college apartment in Chongqing was discussed.The reconstruction plans concerning air-source heat pump heating system and solar assisted air-source heat system were processed and discussed respectively after the analysis on daily hot water load.Compared with the original water-heating system,the annual operating costs of solar heating systems would be the lowest.%以重庆某学校采用燃气锅炉房作为热源的洗浴热水加热系统作为研究对象。对热水系统日用热量进行了分析。对原加热系统提出两种改造方案:空气源热泵加热系统、太阳能辅助空气源加热系统,探讨了这两种加热系统的系统流程,与原加热系统的年运行费用进行了比较,太阳能加热系统的年运行费用最低。

  9. Handbook on heat exchangers

    Science.gov (United States)

    Bazhan, Pavel I.; Kanevets, Georgii E.; Seliverstov, Vladimir M.

    Essential data on heat exchange equipment used in ship, locomotive, automotive, and aircraft powerplants are presented in a systematic manner. The data cover the principal types and technical and performance characteristics of heat exchangers, fundamentals of the theory of heat exchange, calculation of heat transfer coefficients for different types of heat exchange apparatus, optimization of heat exchangers, computer-aided design of heat exchange equipment, testing techniques, and test result processing.

  10. Nonazeotropic Heat Pump

    Science.gov (United States)

    Ealker, David H.; Deming, Glenn

    1991-01-01

    Heat pump collects heat from water circulating in heat-rejection loop, raises temperature of collected heat, and transfers collected heat to water in separate pipe. Includes sealed motor/compressor with cooling coils, evaporator, and condenser, all mounted in outer housing. Gradients of temperature in evaporator and condenser increase heat-transfer efficiency of vapor-compression cycle. Intended to recover relatively-low-temperature waste heat and use it to make hot water.

  11. Nonazeotropic Heat Pump

    Science.gov (United States)

    Ealker, David H.; Deming, Glenn

    1991-01-01

    Heat pump collects heat from water circulating in heat-rejection loop, raises temperature of collected heat, and transfers collected heat to water in separate pipe. Includes sealed motor/compressor with cooling coils, evaporator, and condenser, all mounted in outer housing. Gradients of temperature in evaporator and condenser increase heat-transfer efficiency of vapor-compression cycle. Intended to recover relatively-low-temperature waste heat and use it to make hot water.

  12. Heat Calculation of Borehole Heat Exchangers

    Directory of Open Access Journals (Sweden)

    S. Filatov

    2013-01-01

    Full Text Available The paper considers a heat calculation method of borehole heat exchangers (BHE which can be used for designing and optimization of their design values and included in a comprehensive mathematical model of heat supply system with a heat pump based on utilization of low-grade heat from the ground.The developed method of calculation is based on the reduction of the problem general solution pertaining to heat transfer in BHE with due account of heat transfer between top-down and bottom-up flows of heat carrier to the solution for a boundary condition of one kind on the borehole wall. Used the a method of electrothermal analogy has been used for a calculation of the thermal resistance and  the required shape factors for calculation of  a borehole filler thermal resistance have been obtained numerically. The paper presents results of heat calculation of various BHE designs in accordance with the proposed method.

  13. Heat pump technology

    CERN Document Server

    Von Cube, Hans Ludwig; Goodall, E G A

    2013-01-01

    Heat Pump Technology discusses the history, underlying concepts, usage, and advancements in the use of heat pumps. The book covers topics such as the applications and types of heat pumps; thermodynamic principles involved in heat pumps such as internal energy, enthalpy, and exergy; and natural heat sources and energy storage. Also discussed are topics such as the importance of the heat pump in the energy industry; heat pump designs and systems; the development of heat pumps over time; and examples of practical everyday uses of heat pumps. The text is recommended for those who would like to kno

  14. Cryogenic heat transfer

    CERN Document Server

    Barron, Randall F

    2016-01-01

    Cryogenic Heat Transfer, Second Edition continues to address specific heat transfer problems that occur in the cryogenic temperature range where there are distinct differences from conventional heat transfer problems. This updated version examines the use of computer-aided design in cryogenic engineering and emphasizes commonly used computer programs to address modern cryogenic heat transfer problems. It introduces additional topics in cryogenic heat transfer that include latent heat expressions; lumped-capacity transient heat transfer; thermal stresses; Laplace transform solutions; oscillating flow heat transfer, and computer-aided heat exchanger design. It also includes new examples and homework problems throughout the book, and provides ample references for further study.

  15. Evaporation of alternative refrigerants to R 22 in technical shell and tube heat exchangers; Verdampfung von Ersatzkaeltemitteln fuer R 22 in technischen Rohrbuendel-Waermeaustauschern

    Energy Technology Data Exchange (ETDEWEB)

    Bonekamp, S. [Henkel KGaA, Duesseldorf (Germany)

    2000-05-01

    The refrigerant mixtures R 404A, R 407C, R 410A and R 507 and the pure fluids R 134a, ammonia, propane and propene are mainly recommended for substituting R 22. This report shows the results of heat transfer calculations for these refrigerants over a wide application range for flooded and for direct expansion evaporation. To determine the best substitute for R 22 the heat transfer areas are compared and a ranking for both types of evaporators is presented. (orig.) [German] Als Ersatz fuer R 22 werden hauptsaechlich die Kaeltemittelgemische R 404A, R 407C, R 410A und R 507 sowie die reinen Stoffe R 134a, Ammoniak, Propan und Propen diskutiert. Diese Arbeit stellt Berechnungsergebnisse fuer die verschiedenen Ersatzkaeltemittel in einem grossen technischen Anwendungsbereich sowohl fuer ueberflutete als auch fuer Einspritz-Verdampfer vor. Der Vergleich der ermittelten Waermeaustauschflaechen liefert fuer beide Verdampfungsarten eine Reihenfolge fuer die Verwendbarkeit als Austauschstoff fuer R 22. (orig.)

  16. Critical heat flux around strongly heated nanoparticles.

    Science.gov (United States)

    Merabia, Samy; Keblinski, Pawel; Joly, Laurent; Lewis, Laurent J; Barrat, Jean-Louis

    2009-02-01

    We study heat transfer from a heated nanoparticle into surrounding fluid using molecular dynamics simulations. We show that the fluid next to the nanoparticle can be heated well above its boiling point without a phase change. Under increasing nanoparticle temperature, the heat flux saturates, which is in sharp contrast with the case of flat interfaces, where a critical heat flux is observed followed by development of a vapor layer and heat flux drop. These differences in heat transfer are explained by the curvature-induced pressure close to the nanoparticle, which inhibits boiling. When the nanoparticle temperature is much larger than the critical fluid temperature, a very large temperature gradient develops, resulting in close to ambient temperature just a radius away from the particle surface. The behavior reported allows us to interpret recent experiments where nanoparticles can be heated up to the melting point, without observing boiling of the surrounding liquid.

  17. Heat exchangers for waste heat recovery

    Energy Technology Data Exchange (ETDEWEB)

    Al-Rabghi, O.M.; Akyurt, M.; Najjar, Y.S.H.; Alp, T. (King Abdulaziz Univ., Jeddah (Saudi Arabia). College of Engineering)

    1993-01-01

    A survey is made of the equipment used for heat recovery and utilization. Types and merits of commonly employed heat exchangers are presented, and criteria for selecting heat exchangers are summarized. Applications for waste heat recovery are emphasized. It is concluded that careful selection and operation of such equipment would be expected to result in energy savings as well as problem-free operation. (author)

  18. Oscillating heat pipes

    CERN Document Server

    Ma, Hongbin

    2015-01-01

    This book presents the fundamental fluid flow and heat transfer principles occurring in oscillating heat pipes and also provides updated developments and recent innovations in research and applications of heat pipes. Starting with fundamental presentation of heat pipes, the focus is on oscillating motions and its heat transfer enhancement in a two-phase heat transfer system. The book covers thermodynamic analysis, interfacial phenomenon, thin film evaporation,  theoretical models of oscillating motion and heat transfer of single phase and two-phase flows, primary  factors affecting oscillating motions and heat transfer,  neutron imaging study of oscillating motions in an oscillating heat pipes, and nanofluid’s effect on the heat transfer performance in oscillating heat pipes.  The importance of thermally-excited oscillating motion combined with phase change heat transfer to a wide variety of applications is emphasized. This book is an essential resource and learning tool for senior undergraduate, gradua...

  19. Absorption heat pump system

    Science.gov (United States)

    Grossman, G.

    1982-06-16

    The efficiency of an absorption heat pump system is improved by conducting liquid from a second stage evaporator thereof to an auxiliary heat exchanger positioned downstream of a primary heat exchanger in the desorber of the system.

  20. Multidimensional Heat Conduction

    DEFF Research Database (Denmark)

    Rode, Carsten

    1998-01-01

    Analytical theory of multidimensional heat conduction. General heat conduction equation in three dimensions. Steay state, analytical solutions. The Laplace equation. Method of separation of variables. Principle of superposition. Shape factors. Transient, multidimensional heat conduction....

  1. Regenerative adsorbent heat pump

    Science.gov (United States)

    Jones, Jack A. (Inventor)

    1991-01-01

    A regenerative adsorbent heat pump process and system is provided which can regenerate a high percentage of the sensible heat of the system and at least a portion of the heat of adsorption. A series of at least four compressors containing an adsorbent is provided. A large amount of heat is transferred from compressor to compressor so that heat is regenerated. The process and system are useful for air conditioning rooms, providing room heat in the winter or for hot water heating throughout the year, and, in general, for pumping heat from a lower temperature to a higher temperature.

  2. Water quality assessment of solar-assisted adsorption desalination cycle

    KAUST Repository

    Kim, Youngdeuk

    2014-07-01

    This study focuses on the water quality assessment (feed, product and brine) of the pilot adsorption desalination (AD) plant. Seawater from the Red Sea is used as feed to the AD plant. Water quality tests are evaluated by complying the Environmental Protection Agency (EPA) standards with major primary and secondary inorganic drinking water pollutants and other commonly tested water quality parameters. Chemical testing of desalinated water at the post desalination stage confirms the high quality of produced fresh water. Test results have shown that the adsorption desalination process is very effective in eliminating all forms of salts, as evidenced by the significant reduction of the TDS levels from approximately 40,000. ppm in feed seawater to less than 10. ppm. Test results exhibit extremely low levels of parameters which are generally abundant in feed seawater. The compositions of seawater and process related parameters such as chloride, sodium, bromide, sulfate, calcium, magnesium, and silicate in desalinated water exhibit values of less than 0.1. ppm. Reported conductivity measurements of desalinated water are comparable to distilled water conductivity levels and ranged between 2 and 6. μS/cm while TOC and TIC levels are also extremely low and its value is less than 0.5. ppm. © 2014 Elsevier B.V.

  3. Solar heat storages in district heating networks

    Energy Technology Data Exchange (ETDEWEB)

    Ellehauge, K. (Ellehauge og Kildemoes, AArhus (DK)); Engberg Pedersen, T. (COWI A/S, Kgs. Lyngby (DK))

    2007-07-15

    This report gives information on the work carried out and the results obtained in Denmark on storages for large solar heating plants in district heating networks. Especially in Denmark the share of district heating has increased to a large percentage. In 1981 around 33% of all dwellings in DK were connected to a district heating network, while the percentage in 2006 was about 60% (in total 1.5 mio. dwellings). In the report storage types for short term storage and long term storages are described. Short term storages are done as steel tanks and is well established technology widely used in district heating networks. Long term storages are experimental and used in connection with solar heating. A number of solar heating plants have been established with either short term or long term storages showing economy competitive with normal energy sources. Since, in the majority of the Danish district heating networks the heat is produced in co-generation plants, i.e. plants producing both electricity and heat for the network, special attention has been put on the use of solar energy in combination with co-generation. Part of this report describes that in the liberalized electricity market central solar heating plants can also be advantageous in combination with co-generation plants. (au)

  4. Heat pumps in district heating networks

    DEFF Research Database (Denmark)

    Ommen, Torben Schmidt; Markussen, Wiebke Brix; Elmegaard, Brian

    constraints limit the power plants. Efficient heat pumps can be used to decouple the constraints of electricity and heat production, while maintaining the high energy efficiency needed to match the politically agreed carbon emission goals. The requirements in terms of COP, location, capacity and economy...... are calculated using an energy system model which includes power plants, heat pumps and district heating consumption profiles. The model is developed with focus on accurate representation of the performance of the units in different locations and operating modes. The model can assist in investment decisions...... and strategic planning in the energy sector. The paper presents a case study of optimal implementation of heat pumps in the present energy system of the Copenhagen area. By introduction of the correct capacity of heat pumps, a 1,6 % reduction in fuel consumption for electricity and heat production can...

  5. Transient Heat Conduction

    DEFF Research Database (Denmark)

    Rode, Carsten

    1998-01-01

    Analytical theory of transient heat conduction.Fourier's law. General heat conducation equation. Thermal diffusivity. Biot and Fourier numbers. Lumped analysis and time constant. Semi-infinite body: fixed surface temperature, convective heat transfer at the surface, or constant surface heat flux...

  6. Heat-Related Illnesses

    Medline Plus

    Full Text Available ... sun or any situation that involves extreme heat. Young children and the elderly are most at risk, but anyone can be affected. Here you will find information about heat cramps and heat stroke and exhaustion. Heat Cramps Symptoms include muscle spasms, usually in the legs and stomach area. ...

  7. Nature's Heat Exchangers.

    Science.gov (United States)

    Barnes, George

    1991-01-01

    Discusses the heat-transfer systems of different animals. Systems include heat conduction into the ground, heat transferred by convection, heat exchange in lizards, fish and polar animals, the carotid rete system, electromagnetic radiation from animals and people, and plant and animal fiber optics. (MDH)

  8. Heat Pipe Planets

    Science.gov (United States)

    Moore, William B.; Simon, Justin I.; Webb, A. Alexander G.

    2014-01-01

    When volcanism dominates heat transport, a terrestrial body enters a heat-pipe mode, in which hot magma moves through the lithosphere in narrow channels. Even at high heat flow, a heat-pipe planet develops a thick, cold, downwards-advecting lithosphere dominated by (ultra-)mafic flows and contractional deformation at the surface. Heat-pipes are an important feature of terrestrial planets at high heat flow, as illustrated by Io. Evidence for their operation early in Earth's history suggests that all terrestrial bodies should experience an episode of heat-pipe cooling early in their histories.

  9. Heat Treating Apparatus

    Science.gov (United States)

    De Saro, Robert; Bateman, Willis

    2002-09-10

    Apparatus for heat treating a heat treatable material including a housing having an upper opening for receiving a heat treatable material at a first temperature, a lower opening, and a chamber therebetween for heating the heat treatable material to a second temperature higher than the first temperature as the heat treatable material moves through the chamber from the upper to the lower opening. A gas supply assembly is operatively engaged to the housing at the lower opening, and includes a source of gas, a gas delivery assembly for delivering the gas through a plurality of pathways into the housing in countercurrent flow to movement of the heat treatable material, whereby the heat treatable material passes through the lower opening at the second temperature, and a control assembly for controlling conditions within the chamber to enable the heat treatable material to reach the second temperature and pass through the lower opening at the second temperature as a heated material.

  10. Introduction to heat transfer

    CERN Document Server

    SUNDÉN, B

    2012-01-01

    Presenting the basic mechanisms for transfer of heat, Introduction to Heat Transfer gives a deeper and more comprehensive view than existing titles on the subject. Derivation and presentation of analytical and empirical methods are provided for calculation of heat transfer rates and temperature fields as well as pressure drop. The book covers thermal conduction, forced and natural laminar and turbulent convective heat transfer, thermal radiation including participating media, condensation, evaporation and heat exchangers.

  11. Thermoelectric heat exchange element

    Science.gov (United States)

    Callas, James J.; Taher, Mahmoud A.

    2007-08-14

    A thermoelectric heat exchange module includes a first substrate including a heat receptive side and a heat donative side and a series of undulatory pleats. The module may also include a thermoelectric material layer having a ZT value of 1.0 or more disposed on at least one of the heat receptive side and the heat donative side, and an electrical contact may be in electrical communication with the thermoelectric material layer.

  12. Thermoelectric heat exchange element

    Energy Technology Data Exchange (ETDEWEB)

    Callas, James J. (Peoria, IL); Taher, Mahmoud A. (Peoria, IL)

    2007-08-14

    A thermoelectric heat exchange module includes a first substrate including a heat receptive side and a heat donative side and a series of undulatory pleats. The module may also include a thermoelectric material layer having a ZT value of 1.0 or more disposed on at least one of the heat receptive side and the heat donative side, and an electrical contact may be in electrical communication with the thermoelectric material layer.

  13. Heat transfer, thermal control, and heat pipes

    Science.gov (United States)

    Olstad, W. B.

    1980-01-01

    This volume provides information on recent progress in spacecraft thermal control and the supporting disciplines of conduction, thermal radiation, and heat pipe theory and application. Four problem areas are considered: conduction heat transfer, radiation heat transfer, thermal control, and heat pipes. The topics covered include finite-element methodology for transient conduction/forced-convection thermal analysis; effects of surface finish on thermal contact resistance between different materials; mathematical models for wide-band nongray gas radiation in spherical and cylindrical geometries; thermal design, analysis and testing of the Shuttle remote manipulator arm; porous heat pipe; and transient behavior of liquid trap heat-pipe thermal diodes. Also discussed is the thermal design concept for a high-resolution UV spectrometer.

  14. Heat cascading regenerative sorption heat pump

    Science.gov (United States)

    Jones, Jack A. (Inventor)

    1995-01-01

    A simple heat cascading regenerative sorption heat pump process with rejected or waste heat from a higher temperature chemisorption circuit (HTCC) powering a lower temperature physisorption circuit (LTPC) which provides a 30% total improvement over simple regenerative physisorption compression heat pumps when ammonia is both the chemisorbate and physisorbate, and a total improvement of 50% or more for LTPC having two pressure stages. The HTCC contains ammonia and a chemisorbent therefor contained in a plurality of canisters, a condenser-evaporator-radiator system, and a heater, operatively connected together. The LTPC contains ammonia and a physisorbent therefor contained in a plurality of compressors, a condenser-evaporator-radiator system, operatively connected together. A closed heat transfer circuit (CHTC) is provided which contains a flowing heat transfer liquid (FHTL) in thermal communication with each canister and each compressor for cascading heat from the HTCC to the LTPC. Heat is regenerated within the LTPC by transferring heat from one compressor to another. In one embodiment the regeneration is performed by another CHTC containing another FHTL in thermal communication with each compressor. In another embodiment the HTCC powers a lower temperature ammonia water absorption circuit (LTAWAC) which contains a generator-absorber system containing the absorbent, and a condenser-evaporator-radiator system, operatively connected together. The absorbent is water or an absorbent aqueous solution. A CHTC is provided which contains a FHTL in thermal communication with the generator for cascading heat from the HTCC to the LTAWAC. Heat is regenerated within the LTAWAC by transferring heat from the generator to the absorber. The chemical composition of the chemisorbent is different than the chemical composition of the physisorbent, and the absorbent. The chemical composition of the FHTL is different than the chemisorbent, the physisorbent, the absorbent, and ammonia.

  15. Protecting Yourself from Heat Stress

    Science.gov (United States)

    Fast Facts Protecting Yourself from He at Stress Heat stress, from exertion or hot environments, places workers at risk for illnesses such as heat stroke, heat exhaustion, or heat cramps. Heat Stroke ...

  16. Basic heat transfer

    CERN Document Server

    Bacon, D H

    2013-01-01

    Basic Heat Transfer aims to help readers use a computer to solve heat transfer problems and to promote greater understanding by changing data values and observing the effects, which are necessary in design and optimization calculations.The book is concerned with applications including insulation and heating in buildings and pipes, temperature distributions in solids for steady state and transient conditions, the determination of surface heat transfer coefficients for convection in various situations, radiation heat transfer in grey body problems, the use of finned surfaces, and simple heat exc

  17. Domestic wastewater heat recovery

    OpenAIRE

    Veijola, T.

    2017-01-01

    The aim of this thesis is to study and explain the purpose and the function of drain water heat exchangers. The thesis goes over theory behind heat transfer and heat exchangers and presents the general solutions of domestic drain water heat recovery systems. Systems gone over in detail are the different general shower drain water heat recovery systems. Another part of the thesis is a case study of an actual shower drain water heat recovery system of a Finnish household. The purpose of th...

  18. Heat Roadmap Europe

    DEFF Research Database (Denmark)

    Hansen, Kenneth; Connolly, David; Lund, Henrik

    2015-01-01

    of supplying sustainable heating. Different heat production options are included in terms of individual and community heating systems. Furthermore, the levelised cost of supplying sustainable heat is estimated for both a single technology and from an energy system perspective. The results are analysed...... by assessing various parameters such as socio-economic costs and energy efficiency improvements in the national energy systems. The results demonstrate the economically feasible levels of heat savings and heat production for various European countries, highlighting differences in their national conditions...

  19. High heat flux loop heat pipes

    Science.gov (United States)

    North, Mark T.; Sarraf, David B.; Rosenfeld, John H.; Maidanik, Yuri F.; Vershinin, Sergey

    1997-01-01

    Loop Heat Pipes (LHPs) can transport very large thermal power loads, over long distances, through flexible, small diameter tubes and against high gravitational heads. While recent LHPs have transported as much as 1500 W, the peak heat flux through a LHP's evaporator has been limited to about 0.07 MW/m2. This limitation is due to the arrangement of vapor passages next to the heat load which is one of the conditions necessary to ensure self priming of the device. This paper describes work aimed at raising this limit by threefold to tenfold. Two approaches were pursued. One optimized the vapor passage geometry for the high heat flux conditions. The geometry improved the heat flow into the wick and working fluid. This approach also employed a finer pored wick to support higher vapor flow losses. The second approach used a bidisperse wick material within the circumferential vapor passages. The bidisperse material increased the thermal conductivity and the evaporative surface area in the region of highest heat flux, while providing a flow path for the vapor. Proof-of-concept devices were fabricated and tested for each approach. Both devices operated as designed and both demonstrated operation at a heat flux of 0.70 MW/m2. This performance exceeded the known state of the art by a factor of more than six for both conventional heat pipes and for loop heat pipes using ammonia. In addition, the bidisperse-wick device demonstrated boiling heat transfer coefficients up to 100,000 W/m2.K, and the fine pored device demonstrated an orientation independence with its performance essentially unaffected by whether its evaporator was positioned above, below or level with the condenser.

  20. An electrohydrodynamic heat pipe

    Science.gov (United States)

    Jones, T. B.

    1972-01-01

    Dielectric liquid for transfer of heat provides liquid flow from the condenser section to the evaporator section in conventional heat pipes. Working fluid is guided or pumped by an array of wire electrodes connected to a high-voltage source.

  1. Radial heat flux transformer

    Science.gov (United States)

    Basiulis, A.; Buzzard, R. J.

    1971-01-01

    Unit moves heat radially from small diameter shell to larger diameter shell, or vice versa, with negligible temperature drop, making device useful wherever heating or cooling of concentrically arranged materials, substances, and structures is desired.

  2. Heat-Related Illnesses

    Medline Plus

    Full Text Available ... for Disasters Communication With Your Family And Your Doctor About Your Wishes Visiting the ER Who Takes ... 101 Heat-Related Illnesses Dr. Glenn Mitchell , Emergency physician at Mercy Health System in Chesterfield, Missouri Heat- ...

  3. Convective heat transfer

    CERN Document Server

    Kakac, Sadik; Pramuanjaroenkij, Anchasa

    2014-01-01

    Intended for readers who have taken a basic heat transfer course and have a basic knowledge of thermodynamics, heat transfer, fluid mechanics, and differential equations, Convective Heat Transfer, Third Edition provides an overview of phenomenological convective heat transfer. This book combines applications of engineering with the basic concepts of convection. It offers a clear and balanced presentation of essential topics using both traditional and numerical methods. The text addresses emerging science and technology matters, and highlights biomedical applications and energy technologies. What’s New in the Third Edition: Includes updated chapters and two new chapters on heat transfer in microchannels and heat transfer with nanofluids Expands problem sets and introduces new correlations and solved examples Provides more coverage of numerical/computer methods The third edition details the new research areas of heat transfer in microchannels and the enhancement of convective heat transfer with nanofluids....

  4. Heat Roadmap Europe

    DEFF Research Database (Denmark)

    David, Andrei; Mathiesen, Brian Vad; Averfalk, Helge

    2017-01-01

    The Heat Roadmap Europe (HRE) studies estimated a potential increase of the district heating (DH) share to 50% of the entire heat demand by 2050, with approximately 25–30% of it being supplied using large-scale electric heat pumps. This study builds on this potential and aims to document...... capacity of electric large-scale heat pumps with more than 1 MW thermal output, operating in European DH systems. The survey is the first database of its kind containing the technical characteristics of these heat pumps, and provides the basis for the analysis of this paper. By quantifying the heat sources...... that such developments can begin now with technologies currently available. We present a database and the status of the technology and its ability of expansion to other European locations by reviewing experiences aimed at further research or application in the heating industry. This is based on a survey of the existing...

  5. Experiences with R 407 C as working fluid for heat pumps

    Energy Technology Data Exchange (ETDEWEB)

    Ochsner, K. [Ochsner Waermepumpen, Linz (Austria)

    1994-09-01

    The working fluid issue presents a significant challenge for the heat pump industry. The author has been testing R-407C as alternative working fluid for R 22. R-407C, a blend of R-134a, R-125 and R-32 has an ozone depletion potential of zero, is non-flammable and non-poisonous, and gives the same performance as R-22. Ester oils are used as lubricants. Practical manufacturing issues to be solved included the need for moisture free handling, as traces of water will react with the lubricant. A number of R-407C heat pumps have now been installed at customers, in one case a ground coupled direct expansion system. The author`s rationale to opt for R-407C at this stage is based on its ongoing concern about the public and regulatory acceptability of the safety implications of flammable and/or toxic natural refrigerants. However, it is noted that a number of working fluids, including HFC`s, HFC blends and the `naturals` all have the potential to replace R-22 in the long run. Industry experiences, and, above all, customer wishes will decide in the end. 5 figs., 2 tabs.

  6. Computer Modeling VRF Heat Pumps in Commercial Buildings using EnergyPlus

    Energy Technology Data Exchange (ETDEWEB)

    Raustad, Richard

    2013-07-01

    Variable Refrigerant Flow (VRF) heat pumps are increasingly used in commercial buildings in the United States. Monitored energy use of field installations have shown, in some cases, savings exceeding 30% compared to conventional heating, ventilating, and air-conditioning (HVAC) systems. A simulation study was conducted to identify the installation or operational characteristics that lead to energy savings for VRF systems. The study used the Department of Energy EnergyPlus? building simulation software and four reference building models. Computer simulations were performed in eight U.S. climate zones. The baseline reference HVAC system incorporated packaged single-zone direct-expansion cooling with gas heating (PSZ-AC) or variable-air-volume systems (VAV with reheat). An alternate baseline HVAC system using a heat pump (PSZ-HP) was included for some buildings to directly compare gas and electric heating results. These baseline systems were compared to a VRF heat pump model to identify differences in energy use. VRF systems combine multiple indoor units with one or more outdoor unit(s). These systems move refrigerant between the outdoor and indoor units which eliminates the need for duct work in most cases. Since many applications install duct work in unconditioned spaces, this leads to installation differences between VRF systems and conventional HVAC systems. To characterize installation differences, a duct heat gain model was included to identify the energy impacts of installing ducts in unconditioned spaces. The configuration of variable refrigerant flow heat pumps will ultimately eliminate or significantly reduce energy use due to duct heat transfer. Fan energy is also studied to identify savings associated with non-ducted VRF terminal units. VRF systems incorporate a variable-speed compressor which may lead to operational differences compared to single-speed compression systems. To characterize operational differences, the computer model performance curves used

  7. Heat sink analytical modelling

    OpenAIRE

    Guitart Corominas, Joaquim

    2010-01-01

    Electronics has leaded most technological advances of the past 60 years. There are technologies with domains particularly developed for electronics such as material science, electromagnetism, system dynamics and also heat transfer. The relation to heat transfer is because the heat generation of electronics devices. Commonly, these devices need additional cooling in order to avoid extreme temperatures inside it. Heat sinks allow this supplementary cooling, so they are omnipresent i...

  8. Compact, super heat exchanger

    Science.gov (United States)

    Fortini, A.; Kazaroff, J. M.

    1980-01-01

    Heat exchanger uses porous media to enhance heat transfer through walls of cooling channels, thereby lowering wall temperature. Porous media within cooling channel increases internal surface area from which heat can be transferred to coolant. Comparison data shows wall has lower temperature and coolant has higher temperature when porous medium is used within heat exchanger. Media can be sintered powedered metal, metal fibers, woven wire layers, or any porous metal having desired permeability and porosity.

  9. Heating, ventilation and cooling

    CSIR Research Space (South Africa)

    Osburn, L

    2009-02-01

    Full Text Available content and is evaporated by the air stream with less moisture. Enthalpy wheels are more effective at transferring energy between the air streams as both sensible and latent heat is transferred. Ground-Coupled Heat Exchanger Ground-coupled heat... with high diurnal temperature variations. Evaporative Coolers Evaporative coolers work on the concept that the evaporation of water has a cooling effect on its immediate environment due to the latent heat that it absorbs in order to evaporate...

  10. Heating by wind energy

    Energy Technology Data Exchange (ETDEWEB)

    Auer, F.

    1983-06-01

    The heating of a hang-glider museum on the Rhoen mountains (950 m) is technically feasable and even economic. The investment will pay out within 15-19 years. The heat demand of the museum of maximally 120 KW will be optimized by a 120 KW WECS in combination with a 2-days-heat-storage. So 60% of the yearly heat demand can be covered.

  11. Potential for domestic heat recovery

    Science.gov (United States)

    Feldman, K. T., Jr.; Tsai, G. J.

    1981-11-01

    The potential for reducing gas-fired heating costs by the use of waste heat is discussed. A heat recovery heat exchanger can be installed to recover waste heat from the hot exhaust gases going up the flue pipe from a furnace, water heater, or clothes dryer. Some specific designs are described for heat recovery equipment. Specific design and performance of the Hallofin heat exchanger and the heat pipe heat exchanger are evaluated.

  12. Heat roadmap China

    DEFF Research Database (Denmark)

    Xiong, Weiming; Wang, Yu; Mathiesen, Brian Vad

    2015-01-01

    District heating is regarded as a key element of energy saving actions in the Chinese national energy strategy, while space heating in China is currently still dominated by coal boilers. However, there is no existing quantitative study to analyse the future heat strategy for China. Therefore...

  13. Heat Roadmap Europe 1

    DEFF Research Database (Denmark)

    Connolly, David; Mathiesen, Brian Vad; Østergaard, Poul Alberg

    2012-01-01

    , additional resources are utilised for heat in the district heating network that would otherwise be wasted such as surplus industrial heat, waste incineration, large-scale solar thermal, and geothermal. In all scenarios considered, the results indicate that in the current (2010) and future (2030/2050) EU27...

  14. Heat Roadmap Europe

    DEFF Research Database (Denmark)

    Connolly, David; Mathiesen, Brian Vad; Lund, Henrik

    2015-01-01

    the total heat demand by approximately 30-50%, it will be cheaper to supply heat from a sustainable resource instead of continuing with further savings, which can also enable a higher penetration of renewable energy due to cost shifted from savings and due to the availability of low cost waste heat sources...

  15. Champagne Heat Pump

    Science.gov (United States)

    Jones, Jack A.

    2004-01-01

    The term champagne heat pump denotes a developmental heat pump that exploits a cycle of absorption and desorption of carbon dioxide in an alcohol or other organic liquid. Whereas most heat pumps in common use in the United States are energized by mechanical compression, the champagne heat pump is energized by heating. The concept of heat pumps based on other absorption cycles energized by heat has been understood for years, but some of these heat pumps are outlawed in many areas because of the potential hazards posed by leakage of working fluids. For example, in the case of the water/ammonia cycle, there are potential hazards of toxicity and flammability. The organic-liquid/carbon dioxide absorption/desorption cycle of the champagne heat pump is similar to the water/ammonia cycle, but carbon dioxide is nontoxic and environmentally benign, and one can choose an alcohol or other organic liquid that is also relatively nontoxic and environmentally benign. Two candidate nonalcohol organic liquids are isobutyl acetate and amyl acetate. Although alcohols and many other organic liquids are flammable, they present little or no flammability hazard in the champagne heat pump because only the nonflammable carbon dioxide component of the refrigerant mixture is circulated to the evaporator and condenser heat exchangers, which are the only components of the heat pump in direct contact with air in habitable spaces.

  16. Liquid heat capacity lasers

    Science.gov (United States)

    Comaskey, Brian J.; Scheibner, Karl F.; Ault, Earl R.

    2007-05-01

    The heat capacity laser concept is extended to systems in which the heat capacity lasing media is a liquid. The laser active liquid is circulated from a reservoir (where the bulk of the media and hence waste heat resides) through a channel so configured for both optical pumping of the media for gain and for light amplification from the resulting gain.

  17. Geothermal heat in a heat pump use

    Science.gov (United States)

    Pavlova, A.; Hansen, J.; Obermeyer, H.; Pavlova, I.

    2016-09-01

    The considered innovative technology proposes to use alternative energy sources for the process efficiency in low-height construction. The world economy depends on price rises for energy sources and the danger of environmental pollution increases. Geothermal energy is the basic resource saving and environmentally safe renewable heat source that is characterized by inexhaustibility, permanent all the-year-round use, universal prevalence of resources and the ability to replace considerable volumes of traditional energy carriers. The expediency and power efficiency to apply a heat pump with the use of geothermal heat is proved for low-height construction.

  18. Numerical study of heat pipe application in heat recovery systems

    Energy Technology Data Exchange (ETDEWEB)

    Song Lin; Broadbent, John; McGlen, Ryan [Thermacore Europe, Ashington (United Kingdom)

    2005-01-01

    Heat pipes are two-phase heat transfer devices with extremely high effective thermal conductivity. They can be cylindrical or planar in structure. Heat pipes can be embedded in a metal cooling plate, which is attached to the heat source, and can also be assembled with a fin stack for fluid heat transfer. Due to the high heat transport capacity, heat exchangers with heat pipes have become much smaller than traditional heat exchangers in handling high heat fluxes. With the working fluid in a heat pipe, heat can be absorbed on the evaporator region and transported to the condenser region where the vapour condenses releasing the heat to the cooling media. Heat pipe technology has found increasing applications in enhancing the thermal performance of heat exchangers in microelectronics, energy and other industrial sectors. Utilisation of a heat pipe fin stack in the drying cycle of domestic appliances for heat recovery may lead to a significant energy saving in the domestic sector. However, the design of the heat pipe heat exchanger will meet a number of challenges. This paper presents a design method by using CFD simulation of the dehumidification process with heat pipe heat exchangers. The strategies of simulating the process with heat pipes are presented. The calculated results show that the method can be further used to optimise the design of the heat pipe fin stack. The study suggests that CFD modelling is able to predict thermal performance of the dehumidification solution with heat pipe heat exchangers. (Author)

  19. District Heating System Using Heat Pump Installations and CHP

    Directory of Open Access Journals (Sweden)

    Sit M.L.

    2015-12-01

    Full Text Available The article describes the district heating system, in which part of the heat of return water thermal power is used to supply heat to the district heating puThe article describes the district heating system, in which part of the heat of return water thermal power is used to supply heat to the district heating pumps, evaporators heating and hot water. Heat pumps use carbon dioxide as refrigerant. During the transitional period of the year, and the summer heat pump for preparing hot-water supply system uses the heat of the surrounding air. The heat of the ambient air is used in the intermediate heat exchanger between the first and second stages of the heat pump to cool the gas after the first stage of the compressor of the heat pump.

  20. Heat Roadmap Europe 2

    DEFF Research Database (Denmark)

    Connolly, David; Mathiesen, Brian Vad; Østergaard, Poul Alberg;

    Many strategies have already been proposed for the decarbonisation of the EU energy system by the year 2050. These typically focus on the expansion of renewable energy in the electricity sector and subsequently, electrifying both the heat and transport sectors as much as possible...... are identified and then, the EU27 energy system is modelled to investigate the impact of district heating. The results indicate that a combination of heat savings, district heating in urban areas, and individual heat pumps in rural areas will enable the EU27 to reach its greenhouse gas emission targets by 2050...

  1. Single Electrode Heat Effects

    DEFF Research Database (Denmark)

    Jacobsen, Torben; Broers, G. H. J.

    1977-01-01

    SP, of theelectrode reaction. eta is the overvoltage at the electrode. This equation is appliedto a high temperature carbonate fuel cell. It is shown that the Peltier entropyterm by far exceeds the heat production due to the irreversible losses, and thatthe main part of heat evolved at the cathode is reabsorbed......The heat evolution at a single irreversibly working electrode is treated onthe basis of the Brønsted heat principle. The resulting equation is analogous to the expression for the total heat evolution in a galvanic cellwith the exception that –DeltaS is substituted by the Peltier entropy, Delta...

  2. Heat Rash (Prickly Heat or Miliaria)

    Science.gov (United States)

    ... infection, such as: Increased pain, swelling, redness or warmth around the affected area Pus draining from the ... climates. Hot, humid weather can cause heat rash. Physical activity. Intense exercise, hard work or any activity ...

  3. Flexible heating head for induction heating

    Science.gov (United States)

    Fox, Robert L. (Inventor); Johnson, Samuel D. (Inventor); Coultrip, Robert H. (Inventor); Phillips, W. Morris (Inventor)

    1993-01-01

    An induction heating head includes a length of wire having first and second opposite ends and being wound in a flat spiral shape to form an induction coil, a capacitor connected to the first and second ends of the wire, the induction coil and capacitor defining a tank circuit, and a flexible, elastomeric body molded to encase the induction coil. When a susceptor is placed in juxtaposition to the body, and the tank circuit is powered, the susceptor is inductively heated.

  4. Heat Roadmap Europe 2

    DEFF Research Database (Denmark)

    Connolly, David; Mathiesen, Brian Vad; Østergaard, Poul Alberg

    Many strategies have already been proposed for the decarbonisation of the EU energy system by the year 2050. These typically focus on the expansion of renewable energy in the electricity sector and subsequently, electrifying both the heat and transport sectors as much as possible. In these strate......Many strategies have already been proposed for the decarbonisation of the EU energy system by the year 2050. These typically focus on the expansion of renewable energy in the electricity sector and subsequently, electrifying both the heat and transport sectors as much as possible....... In these strategies, the role of district heating has never been fully explored system, nor have the benefits of district heating been quantified at the EU level. This study combines the mapping of local heat demands and local heat supplies across the EU27. Using this local knowledge, new district heating potentials...... are identified and then, the EU27 energy system is modelled to investigate the impact of district heating. The results indicate that a combination of heat savings, district heating in urban areas, and individual heat pumps in rural areas will enable the EU27 to reach its greenhouse gas emission targets by 2050...

  5. Active microchannel heat exchanger

    Science.gov (United States)

    Tonkovich, Anna Lee Y [Pasco, WA; Roberts, Gary L [West Richland, WA; Call, Charles J [Pasco, WA; Wegeng, Robert S [Richland, WA; Wang, Yong [Richland, WA

    2001-01-01

    The present invention is an active microchannel heat exchanger with an active heat source and with microchannel architecture. The microchannel heat exchanger has (a) an exothermic reaction chamber; (b) an exhaust chamber; and (c) a heat exchanger chamber in thermal contact with the exhaust chamber, wherein (d) heat from the exothermic reaction chamber is convected by an exothermic reaction exhaust through the exhaust chamber and by conduction through a containment wall to the working fluid in the heat exchanger chamber thereby raising a temperature of the working fluid. The invention is particularly useful as a liquid fuel vaporizer and/or a steam generator for fuel cell power systems, and as a heat source for sustaining endothermic chemical reactions and initiating exothermic reactions.

  6. Economics of heat pump systems for simultaneous heating and cooling

    Energy Technology Data Exchange (ETDEWEB)

    Ghosh, S.; Devotta, S.; Patwardhan, V.S.

    1987-01-01

    Heat pumps can be incorporated advantageously into processes which require simultaneously both cooling and heating. The economics of heat pumps in India for simultaneous heat and cooling is assessed with respect to process, design and economic parameters. For the typical conditions of various parameters in India, a heat pump system for simultaneous heating and cooling is very attractive.

  7. Optimization of Heat Exchangers

    Energy Technology Data Exchange (ETDEWEB)

    Ivan Catton

    2010-10-01

    The objective of this research is to develop tools to design and optimize heat exchangers (HE) and compact heat exchangers (CHE) for intermediate loop heat transport systems found in the very high temperature reator (VHTR) and other Generation IV designs by addressing heat transfer surface augmentation and conjugate modeling. To optimize heat exchanger, a fast running model must be created that will allow for multiple designs to be compared quickly. To model a heat exchanger, volume averaging theory, VAT, is used. VAT allows for the conservation of mass, momentum and energy to be solved for point by point in a 3 dimensional computer model of a heat exchanger. The end product of this project is a computer code that can predict an optimal configuration for a heat exchanger given only a few constraints (input fluids, size, cost, etc.). As VAT computer code can be used to model characteristics )pumping power, temperatures, and cost) of heat exchangers more quickly than traditional CFD or experiment, optimization of every geometric parameter simultaneously can be made. Using design of experiment, DOE and genetric algorithms, GE, to optimize the results of the computer code will improve heat exchanger disign.

  8. Silicon Heat Pipe Array

    Science.gov (United States)

    Yee, Karl Y.; Ganapathi, Gani B.; Sunada, Eric T.; Bae, Youngsam; Miller, Jennifer R.; Beinsford, Daniel F.

    2013-01-01

    Improved methods of heat dissipation are required for modern, high-power density electronic systems. As increased functionality is progressively compacted into decreasing volumes, this need will be exacerbated. High-performance chip power is predicted to increase monotonically and rapidly with time. Systems utilizing these chips are currently reliant upon decades of old cooling technology. Heat pipes offer a solution to this problem. Heat pipes are passive, self-contained, two-phase heat dissipation devices. Heat conducted into the device through a wick structure converts the working fluid into a vapor, which then releases the heat via condensation after being transported away from the heat source. Heat pipes have high thermal conductivities, are inexpensive, and have been utilized in previous space missions. However, the cylindrical geometry of commercial heat pipes is a poor fit to the planar geometries of microelectronic assemblies, the copper that commercial heat pipes are typically constructed of is a poor CTE (coefficient of thermal expansion) match to the semiconductor die utilized in these assemblies, and the functionality and reliability of heat pipes in general is strongly dependent on the orientation of the assembly with respect to the gravity vector. What is needed is a planar, semiconductor-based heat pipe array that can be used for cooling of generic MCM (multichip module) assemblies that can also function in all orientations. Such a structure would not only have applications in the cooling of space electronics, but would have commercial applications as well (e.g. cooling of microprocessors and high-power laser diodes). This technology is an improvement over existing heat pipe designs due to the finer porosity of the wick, which enhances capillary pumping pressure, resulting in greater effective thermal conductivity and performance in any orientation with respect to the gravity vector. In addition, it is constructed of silicon, and thus is better

  9. Floor heating maximizes residents` comfort

    Energy Technology Data Exchange (ETDEWEB)

    Tirkkanen, P.; Wikstroem, T.

    1996-11-01

    Storing heat in floors by using economical night-time electricity does not increase the specific consumption of heating. According to studies done by IVO, the optimum housing comfort is achieved if the room is heated mainly by means of floor heating that is evened out by window or ceiling heating, or by a combination of all three forms of heating. (orig.)

  10. "Bottle-Brush" Heat Exchanger

    Science.gov (United States)

    Tward, E.; Gatewood, J. R.

    1982-01-01

    Heat exchanger consists of a metal tube with wires extending inward from wall. Conduction of heat along wires improves heat transfer to gas or other filling. Fluid is heated throughout the cross section of tube. Suggested applications are refrigerators, heat engines, thermal instrumentation, and heat switches.

  11. Floor heating maximizes residents` comfort

    Energy Technology Data Exchange (ETDEWEB)

    Tirkkanen, P.; Wikstroem, T.

    1996-11-01

    Storing heat in floors by using economical night-time electricity does not increase the specific consumption of heating. According to studies done by IVO, the optimum housing comfort is achieved if the room is heated mainly by means of floor heating that is evened out by window or ceiling heating, or by a combination of all three forms of heating. (orig.)

  12. Performance characteristic of thermosyphon heat pipe at radiant heat source

    Science.gov (United States)

    Hrabovský, Peter; Papučík, Štefan; Kaduchová, Katarína

    2016-06-01

    This article discusses about device, which is called heat pipe. This device is with heat source with radiant heat source. Heat pipe is device with high efficiency of heat transfer. The heat pipe, which is describe in this article is termosyphon heat pipe. The experiment with termosyphon heat pipe get a result. On the base of result, it will be in future to create mathematical model in Ansys. Thermosyphon heat pipe is made of copper and distilled water is working fluid. The significance of this experiment consists in getting of the heat transfer and performance characteristic. On the basis of measured and calculated data can be constructed the plots.

  13. Heat-pipe Earth.

    Science.gov (United States)

    Moore, William B; Webb, A Alexander G

    2013-09-26

    The heat transport and lithospheric dynamics of early Earth are currently explained by plate tectonic and vertical tectonic models, but these do not offer a global synthesis consistent with the geologic record. Here we use numerical simulations and comparison with the geologic record to explore a heat-pipe model in which volcanism dominates surface heat transport. These simulations indicate that a cold and thick lithosphere developed as a result of frequent volcanic eruptions that advected surface materials downwards. Declining heat sources over time led to an abrupt transition to plate tectonics. Consistent with model predictions, the geologic record shows rapid volcanic resurfacing, contractional deformation, a low geothermal gradient across the bulk of the lithosphere and a rapid decrease in heat-pipe volcanism after initiation of plate tectonics. The heat-pipe Earth model therefore offers a coherent geodynamic framework in which to explore the evolution of our planet before the onset of plate tectonics.

  14. Heat transfer II essentials

    CERN Document Server

    REA, The Editors of

    1988-01-01

    REA's Essentials provide quick and easy access to critical information in a variety of different fields, ranging from the most basic to the most advanced. As its name implies, these concise, comprehensive study guides summarize the essentials of the field covered. Essentials are helpful when preparing for exams, doing homework and will remain a lasting reference source for students, teachers, and professionals. Heat Transfer II reviews correlations for forced convection, free convection, heat exchangers, radiation heat transfer, and boiling and condensation.

  15. Advances in heat transfer

    CERN Document Server

    Hartnett, James P; Cho, Young I; Greene, George A

    2001-01-01

    Heat transfer is the exchange of heat energy between a system and its surrounding environment, which results from a temperature difference and takes place by means of a process of thermal conduction, mechanical convection, or electromagnetic radiation. Advances in Heat Transfer is designed to fill the information gap between regularly scheduled journals and university-level textbooks by providing in-depth review articles over a broader scope than is allowable in either journals or texts.

  16. NCSX Plasma Heating Methods

    Energy Technology Data Exchange (ETDEWEB)

    H.W. Kugel; D. Spong; R. Majeski; M. Zarnstorff

    2003-02-28

    The NCSX (National Compact Stellarator Experiment) has been designed to accommodate a variety of heating systems, including ohmic heating, neutral-beam injection, and radio-frequency. Neutral beams will provide one of the primary heating methods for NCSX. In addition to plasma heating, beams are also expected to provide a means for external control over the level of toroidal plasma rotation velocity and its profile. The plan is to provide 3 MW of 50 keV balanced neutral-beam tangential injection with pulse lengths of 500 msec for initial experiments, and to be upgradeable to pulse lengths of 1.5 sec. Subsequent upgrades will add 3 MW of neutral-beam injection. This Chapter discusses the NCSX neutral-beam injection requirements and design issues, and shows how these are provided by the candidate PBX-M (Princeton Beta Experiment-Modification) neutral-beam injection system. In addition, estimations are given for beam-heating efficiencies, scaling of heating efficiency with machine size an d magnetic field level, parameter studies of the optimum beam-injection tangency radius and toroidal injection location, and loss patterns of beam ions on the vacuum chamber wall to assist placement of wall armor and for minimizing the generation of impurities by the energetic beam ions. Finally, subsequent upgrades could add an additional 6 MW of radio-frequency heating by mode-conversion ion-Bernstein wave (MCIBW) heating, and if desired as possible future upgrades, the design also will accommodate high-harmonic fast-wave and electron-cyclotron heating. The initial MCIBW heating technique and the design of the radio-frequency system lend themselves to current drive, so that if current drive became desirable for any reason only minor modifications to the heating system described here would be needed. The radio-frequency system will also be capable of localized ion heating (bulk or tail), and possibly ion-Bernstein-wave-generated sheared flows.

  17. NCSX Plasma Heating Methods

    Energy Technology Data Exchange (ETDEWEB)

    Kugel, H. W.; Spong, D.; Majeski, R.; Zarnstorff, M.

    2008-01-18

    The National Compact Stellarator Experiment (NCSX) has been designed to accommodate a variety of heating systems, including ohmic heating, neutral beam injection, and radio-frequency (rf). Neutral beams will provide one of the primary heating methods for NCSX. In addition to plasma heating, neutral beams are also expected to provide a means for external control over the level of toroidal plasma rotation velocity and its profile. The experimental plan requires 3 MW of 50-keV balanced neutral beam tangential injection with pulse lengths of 500 ms for initial experiments, to be upgradeable to pulse lengths of 1.5 s. Subsequent upgrades will add 3MW of neutral beam injection (NBI). This paper discusses the NCSX NBI requirements and design issues and shows how these are provided by the candidate PBX-M NBI system. In addition, estimations are given for beam heating efficiencies, scaling of heating efficiency with machine size and magnetic field level, parameter studies of the optimum beam injection tangency radius and toroidal injection location, and loss patterns of beam ions on the vacuum chamber wall to assist placement of wall armor and for minimizing the generation of impurities by the energetic beam ions. Finally, subsequent upgrades could add an additional 6 MW of rf heating by mode conversion ion Bernstein wave (MCIBW) heating, and if desired as possible future upgrades, the design also will accommodate high-harmonic fast-wave and electron cyclotron heating. The initial MCIBW heating technique and the design of the rf system lend themselves to current drive, so if current drive became desirable for any reason, only minor modifications to the heating system described here would be needed. The rf system will also be capable of localized ion heating (bulk or tail), and possiblyIBW-generated sheared flows.

  18. Mechanisms of Coronal Heating

    Indian Academy of Sciences (India)

    S. R. Verma

    2006-06-01

    The Sun is a mysterious star. The high temperature of the chromosphere and corona present one of the most puzzling problems of solar physics. Observations show that the solar coronal heating problem is highly complex with many different facts. It is likely that different heating mechanisms are at work in solar corona. Recent observations show that Magnetic Carpet is a potential candidate for solar coronal heating.

  19. Convection heat transfer

    CERN Document Server

    Bejan, Adrian

    2013-01-01

    Written by an internationally recognized authority on heat transfer and thermodynamics, this second edition of Convection Heat Transfer contains new and updated problems and examples reflecting real-world research and applications, including heat exchanger design. Teaching not only structure but also technique, the book begins with the simplest problem solving method (scale analysis), and moves on to progressively more advanced and exact methods (integral method, self similarity, asymptotic behavior). A solutions manual is available for all problems and exercises.

  20. Joule heating in nanowires

    OpenAIRE

    Fangohr, H.; Chernyshenko, D.; Franchin, Matteo; Fischbacher, Thomas; Meier, G.

    2011-01-01

    We study the effect of Joule heating from electric currents flowing through ferromagnetic nanowires on the temperature of the nanowires and on the temperature of the substrate on which the nanowires are grown. The spatial current density distribution, the associated heat generation, and diffusion of heat is simulated within the nanowire and the substrate. We study several different nanowire and constriction geometries as well as different substrates: (thin) silicon nitride membranes, (thick) ...

  1. Induction Heating Systems

    Science.gov (United States)

    1991-01-01

    Induction heating technology, a magnetic non-deforming process, was developed by Langley researchers to join plastic and composite components in space. Under NASA license, Inductron Corporation uses the process to produce induction heating systems and equipment for numerous applications. The Torobonder, a portable system, comes with a number of interchangeable heads for aircraft repair. Other developments are the E Heating Head, the Toroid Joining Gun, and the Torobrazer. These products perform bonding applications more quickly, safely and efficiently than previous methods.

  2. Counterflow Regolith Heat Exchanger

    Science.gov (United States)

    Zubrin, Robert; Jonscher, Peter

    2013-01-01

    A problem exists in reducing the total heating power required to extract oxygen from lunar regolith. All such processes require heating a great deal of soil, and the heat energy is wasted if it cannot be recycled from processed material back into new material. The counterflow regolith heat exchanger (CoRHE) is a device that transfers heat from hot regolith to cold regolith. The CoRHE is essentially a tube-in-tube heat exchanger with internal and external augers attached to the inner rotating tube to move the regolith. Hot regolith in the outer tube is moved in one direction by a right-hand - ed auger, and the cool regolith in the inner tube is moved in the opposite direction by a left-handed auger attached to the inside of the rotating tube. In this counterflow arrangement, a large fraction of the heat from the expended regolith is transferred to the new regolith. The spent regolith leaves the heat exchanger close to the temperature of the cold new regolith, and the new regolith is pre-heated close to the initial temperature of the spent regolith. Using the CoRHE can reduce the heating requirement of a lunar ISRU system by 80%, reducing the total power consumption by a factor of two. The unique feature of this system is that it allows for counterflow heat exchange to occur between solids, instead of liquids or gases, as is commonly done. In addition, in variants of this concept, the hydrogen reduction can be made to occur within the counterflow heat exchanger itself, enabling a simplified lunar ISRU (in situ resource utilization) system with excellent energy economy and continuous nonbatch mode operation.

  3. Heat and thermodynamics

    CERN Document Server

    Saxena, A K

    2014-01-01

    Heat and thermodynamics aims to serve as a textbook for Physics, Chemistry and Engineering students. The book covers basic ideas of Heat and Thermodynamics, Kinetic Theory and Transport Phenomena, Real Gases, Liquafaction and Production and Measurement of very Low Temperatures, The First Law of Thermodynamics, The Second and Third Laws of Thermodynamics and Heat Engines and Black Body Radiation. KEY FEATURES Emphasis on concepts Contains 145 illustrations (drawings), 9 Tables and 48 solved examples At the end of chapter exercises and objective questions

  4. Laser Processed Heat Exchangers

    Science.gov (United States)

    Hansen, Scott

    2017-01-01

    The Laser Processed Heat Exchanger project will investigate the use of laser processed surfaces to reduce mass and volume in liquid/liquid heat exchangers as well as the replacement of the harmful and problematic coatings of the Condensing Heat Exchangers (CHX). For this project, two scale unit test articles will be designed, manufactured, and tested. These two units are a high efficiency liquid/liquid HX and a high reliability CHX.

  5. Heat Pipe Materials Compatibility

    Science.gov (United States)

    Eninger, J. E.; Fleischman, G. L.; Luedke, E. E.

    1976-01-01

    An experimental program to evaluate noncondensable gas generation in ammonia heat pipes was completed. A total of 37 heat pipes made of aluminum, stainless steel and combinations of these materials were processed by various techniques, operated at different temperatures and tested at low temperature to quantitatively determine gas generation rates. In order of increasing stability are aluminum/stainless combination, all aluminum and all stainless heat pipes. One interesting result is the identification of intentionally introduced water in the ammonia during a reflux step as a means of surface passivation to reduce gas generation in stainless-steel/aluminum heat pipes.

  6. Quantum heat traces

    CERN Document Server

    Avramidi, Ivan G

    2016-01-01

    We study new invariants of elliptic partial differential operators acting on sections of a vector bundle over a closed Riemannian manifold that we call the relativistic heat trace and the quantum heat traces. We obtain some reduction formulas expressing these new invariants in terms of some integral transforms of the usual classical heat trace and compute the asymptotics of these invariants. The coefficients of these asymptotic expansion are determined by the usual heat trace coefficients (which are locally computable) as well as by some new global invariants.

  7. Introduction to Heat Pipes

    Science.gov (United States)

    Ku, Jentung

    2015-01-01

    This is the presentation file for the short course Introduction to Heat Pipes, to be conducted at the 2015 Thermal Fluids and Analysis Workshop, August 3-7, 2015, Silver Spring, Maryland. NCTS 21070-15. Course Description: This course will present operating principles of the heat pipe with emphases on the underlying physical processes and requirements of pressure and energy balance. Performance characterizations and design considerations of the heat pipe will be highlighted. Guidelines for thermal engineers in the selection of heat pipes as part of the spacecraft thermal control system, testing methodology, and analytical modeling will also be discussed.

  8. Heated Tube Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The Heated Tube Facility at NASA GRC investigates cooling issues by simulating conditions characteristic of rocket engine thrust chambers and high speed airbreathing...

  9. Heat transfer equipment design

    Science.gov (United States)

    Shah, R. K.; Subbarao, Eleswarapu Chinna; Mashelkar, R. A.

    A comprehensive presentation is made of state-of-the-art configurations and design methodologies for heat transfer devices applicable to industrial processes, automotive systems, air conditioning/refrigeration, cryogenics, and petrochemicals refining. Attention is given to topics in heat exchanger mechanical design, single-phase convection processes, thermal design, two-phase exchanger thermal design, heat-transfer augmentation, and rheological effects. Computerized analysis and design methodologies are presented for the range of heat transfer systems, as well as advanced methods for optimization and performance projection.

  10. Quantum heat traces

    Science.gov (United States)

    Avramidi, Ivan G.

    2017-02-01

    We study new invariants of elliptic partial differential operators acting on sections of a vector bundle over a closed Riemannian manifold that we call the relativistic heat trace and the quantum heat traces. We obtain some reduction formulas expressing these new invariants in terms of some integral transforms of the usual classical heat trace and compute the asymptotics of these invariants. The coefficients of these asymptotic expansion are determined by the usual heat trace coefficients (which are locally computable) as well as by some new global invariants.

  11. An electrohydrodynamic heat pipe.

    Science.gov (United States)

    Jones, T. B.

    1972-01-01

    A heat pipe of new design, using an electrode structure to orient and guide the dielectric liquid phase flow, is proposed. Analysis indicates that the operation of the electrohydrodynamic heat pipe is in direct analogy to capillary devices, with the polarization force acting in place of capillarity. Advantages of these new heat pipes include greatly reduced liquid friction, electrohydrodynamically enhanced evaporation and condensation heat transfer, and a possible voltage-controlled on/off feature. Preliminary calculations indicate that relatively high performance devices are possible.

  12. Heat rejection system

    Science.gov (United States)

    Smith, Gregory C.; Tokarz, Richard D.; Parry, Jr., Harvey L.; Braun, Daniel J.

    1980-01-01

    A cooling system for rejecting waste heat consists of a cooling tower incorporating a plurality of coolant tubes provided with cooling fins and each having a plurality of cooling channels therein, means for directing a heat exchange fluid from the power plant through less than the total number of cooling channels to cool the heat exchange fluid under normal ambient temperature conditions, means for directing water through the remaining cooling channels whenever the ambient temperature rises above the temperature at which dry cooling of the heat exchange fluid is sufficient and means for cooling the water.

  13. Reclaiming Waste Heat

    Science.gov (United States)

    1976-01-01

    'Air-O-Space' heater, based on spacecraft heat, requires no fuel other than electricity to run fan. Installed in chimney flue, heat pipes transfer heat from waste hot gases (but not the gases themselves) to fresh air blown across the other end of the pipes. It can transport roughly 500 times the heat flux of the best solid conductors with a temperature drop of less than 3 degrees per foot. This instrument has also been used by Kin-Tek Laboratories Inc. to produce an instrument to calibrate gas analyzers for air-pollution monitoring.

  14. EVALUATION OF A MULTIFUNCTIONAL VALVE ASSEMBLY IN A DIRECT EXPANSION REFRIGERATION SYSTEM REPORT

    Science.gov (United States)

    The report describes the performance, including energy consumption, of a refrigeration system incorporating a multifunctional valve (MXV assembly). The MXV assembly (consisting of additional liquid line, an XTC valve, and a larger thermostatic expansion valve) was installed on al...

  15. Dynamic behavior of a direct expansion evaporator under frosting condition. Part I. Distributed model

    Energy Technology Data Exchange (ETDEWEB)

    Tso, C.P. [Multimedia University, Melaka (Malaysia). Faculty of Engineering and Technology; Cheng, Y.C.; Lai, A.C.K. [Nanyang Technological University, Singapore 634798 (Singapore). School of Mechanical and Aerospace Engineering

    2006-06-15

    A general distributed model with two-phase flow for refrigerant coupled with a frost model is developed for studying the dynamic behavior of an evaporator. The equations are derived in non-steady-state manner for the refrigerant and a quasi-steady state model with permeation for the frost. The complex flow and geometry of the finned tube evaporator lead to uneven wall and air temperature distributions, which in turn affect the rate of frost growth and densification along the coil depth. Results include frost accumulation and its effect on energy transfer, air off-coil temperature, refrigerant liquid dry-out position and propagation of frost formation along the coil. (author)

  16. Heat Pipe Integrated Microsystems

    Energy Technology Data Exchange (ETDEWEB)

    Gass, K.; Robertson, P.J.; Shul, R.; Tigges, C.

    1999-03-30

    The trend in commercial electronics packaging to deliver ever smaller component packaging has enabled the development of new highly integrated modules meeting the demands of the next generation nano satellites. At under ten kilograms, these nano satellites will require both a greater density electronics and a melding of satellite structure and function. Better techniques must be developed to remove the subsequent heat generated by the active components required to-meet future computing requirements. Integration of commercially available electronics must be achieved without the increased costs normally associated with current generation multi chip modules. In this paper we present a method of component integration that uses silicon heat pipe technology and advanced flexible laminate circuit board technology to achieve thermal control and satellite structure. The' electronics/heat pipe stack then becomes an integral component of the spacecraft structure. Thermal management on satellites has always been a problem. The shrinking size of electronics and voltage requirements and the accompanying reduction in power dissipation has helped the situation somewhat. Nevertheless, the demands for increased onboard processing power have resulted in an ever increasing power density within the satellite body. With the introduction of nano satellites, small satellites under ten kilograms and under 1000 cubic inches, the area available on which to place hot components for proper heat dissipation has dwindled dramatically. The resulting satellite has become nearly a solid mass of electronics with nowhere to dissipate heat to space. The silicon heat pipe is attached to an aluminum frame using a thermally conductive epoxy or solder preform. The frame serves three purposes. First, the aluminum frame provides a heat conduction path from the edge of the heat pipe to radiators on the surface of the satellite. Secondly, it serves as an attachment point for extended structures attached

  17. 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.

  18. Solar Heating System with Building-Integrated Heat Storage

    DEFF Research Database (Denmark)

    Heller, Alfred

    1996-01-01

    Traditional solar heating systems cover between 5 and 10% of the heat demand fordomestic hot water and comfort heating. By applying storage capacity this share can beincreased much. The Danish producer of solar heating systems, Aidt-Miljø, markets such a system including storage of dry sand heated...... by PP-pipe heat exchanger. Heat demand is reduced due to direct solar heating, and due to storage. Heat demand is reduced due to direct solar heating, due to storage and due to lower heat losses through the ground. In theory, by running the system flow backwards through the sand storage, active heating...... can be achieved.The objective of the report is to present results from measured system evaluation andcalculations and to give guidelines for the design of such solar heating systems with building integrated sand storage. The report is aimed to non-technicians. In another report R-006 the main results...

  19. Heat pipes and use of heat pipes in furnace exhaust

    Science.gov (United States)

    Polcyn, Adam D.

    2010-12-28

    An array of a plurality of heat pipe are mounted in spaced relationship to one another with the hot end of the heat pipes in a heated environment, e.g. the exhaust flue of a furnace, and the cold end outside the furnace. Heat conversion equipment is connected to the cold end of the heat pipes.

  20. Heat-Related Illnesses

    Medline Plus

    Full Text Available ... heat stroke and exhaustion. Heat Cramps Symptoms include muscle spasms, usually in the legs and stomach area. To treat, have the person rest in a cool place and give small amounts of cool water, juice or a commercial sports liquid. (Do not ...

  1. Cold Climate Heat Pump

    Science.gov (United States)

    2013-08-01

    12. Data set 7 – energy consumption of heat pump and furnace ................................ 22 Figure 13. Experimentally adjusted TRNSYS model...minute SCF standard cubic feet SEER seasonal energy efficiency ratio SH superheated TMY Typical Meteorological Year TRNSYS Transient Systems...Simulation Program ( TRNSYS ), to generate an experimentally adjusted, simulation heating seasonal performance. 6.4.1 Simulation Results The TRNSYS model

  2. Microchannel heat sink assembly

    Science.gov (United States)

    Bonde, Wayne L.; Contolini, Robert J.

    1992-01-01

    The present invention provides a microchannel heat sink with a thermal range from cryogenic temperatures to several hundred degrees centigrade. The heat sink can be used with a variety of fluids, such as cryogenic or corrosive fluids, and can be operated at a high pressure. The heat sink comprises a microchannel layer preferably formed of silicon, and a manifold layer preferably formed of glass. The manifold layer comprises an inlet groove and outlet groove which define an inlet manifold and an outlet manifold. The inlet manifold delivers coolant to the inlet section of the microchannels, and the outlet manifold receives coolant from the outlet section of the microchannels. In one embodiment, the manifold layer comprises an inlet hole extending through the manifold layer to the inlet manifold, and an outlet hole extending through the manifold layer to the outlet manifold. Coolant is supplied to the heat sink through a conduit assembly connected to the heat sink. A resilient seal, such as a gasket or an O-ring, is disposed between the conduit and the hole in the heat sink in order to provide a watetight seal. In other embodiments, the conduit assembly may comprise a metal tube which is connected to the heat sink by a soft solder. In still other embodiments, the heat sink may comprise inlet and outlet nipples. The present invention has application in supercomputers, integrated circuits and other electronic devices, and is suitable for cooling materials to superconducting temperatures.

  3. Passive Vaporizing Heat Sink

    Science.gov (United States)

    Knowles, TImothy R.; Ashford, Victor A.; Carpenter, Michael G.; Bier, Thomas M.

    2011-01-01

    A passive vaporizing heat sink has been developed as a relatively lightweight, compact alternative to related prior heat sinks based, variously, on evaporation of sprayed liquids or on sublimation of solids. This heat sink is designed for short-term dissipation of a large amount of heat and was originally intended for use in regulating the temperature of spacecraft equipment during launch or re-entry. It could also be useful in a terrestrial setting in which there is a requirement for a lightweight, compact means of short-term cooling. This heat sink includes a hermetic package closed with a pressure-relief valve and containing an expendable and rechargeable coolant liquid (e.g., water) and a conductive carbon-fiber wick. The vapor of the liquid escapes when the temperature exceeds the boiling point corresponding to the vapor pressure determined by the setting of the pressure-relief valve. The great advantage of this heat sink over a melting-paraffin or similar phase-change heat sink of equal capacity is that by virtue of the =10x greater latent heat of vaporization, a coolant-liquid volume equal to =1/10 of the paraffin volume can suffice.

  4. Heat and Motion.

    Science.gov (United States)

    Pearlman, Norman

    Unlike many elementary presentations on heat, this monograph is not restricted to explaining thermal behavior in only macroscopic terms, but also developes the relationships between thermal properties and atomic behavior. "It relies at the start on intuition about heat at the macroscopic level. Familiarity with the particle model of mechanics,…

  5. Electron heat flux instability

    Science.gov (United States)

    Saeed, Sundas; Sarfraz, M.; Yoon, P. H.; Lazar, M.; Qureshi, M. N. S.

    2017-02-01

    The heat flux instability is an electromagnetic mode excited by a relative drift between the protons and two-component core-halo electrons. The most prominent application may be in association with the solar wind where drifting electron velocity distributions are observed. The heat flux instability is somewhat analogous to the electrostatic Buneman or ion-acoustic instability driven by the net drift between the protons and bulk electrons, except that the heat flux instability operates in magnetized plasmas and possesses transverse electromagnetic polarization. The heat flux instability is also distinct from the electrostatic counterpart in that it requires two electron species with relative drifts with each other. In the literature, the heat flux instability is often called the 'whistler' heat flux instability, but it is actually polarized in the opposite sense to the whistler wave. This paper elucidates all of these fundamental plasma physical properties associated with the heat flux instability starting from a simple model, and gradually building up more complexity towards a solar wind-like distribution functions. It is found that the essential properties of the instability are already present in the cold counter-streaming electron model, and that the instability is absent if the protons are ignored. These instability characteristics are highly reminiscent of the electron firehose instability driven by excessive parallel temperature anisotropy, propagating in parallel direction with respect to the ambient magnetic field, except that the free energy source for the heat flux instability resides in the effective parallel pressure provided by the counter-streaming electrons.

  6. Scraped surface heat exchangers.

    Science.gov (United States)

    Rao, Chetan S; Hartel, Richard W

    2006-01-01

    Scraped surface heat exchangers (SSHEs) are commonly used in the food, chemical, and pharmaceutical industries for heat transfer, crystallization, and other continuous processes. They are ideally suited for products that are viscous, sticky, that contain particulate matter, or that need some degree of crystallization. Since these characteristics describe a vast majority of processed foods, SSHEs are especially suited for pumpable food products. During operation, the product is brought in contact with a heat transfer surface that is rapidly and continuously scraped, thereby exposing the surface to the passage of untreated product. In addition to maintaining high and uniform heat exchange, the scraper blades also provide simultaneous mixing and agitation. Heat exchange for sticky and viscous foods such as heavy salad dressings, margarine, chocolate, peanut butter, fondant, ice cream, and shortenings is possible only by using SSHEs. High heat transfer coefficients are achieved because the boundary layer is continuously replaced by fresh material. Moreover, the product is in contact with the heating surface for only a few seconds and high temperature gradients can be used without the danger of causing undesirable reactions. SSHEs are versatile in the use of heat transfer medium and the various unit operations that can be carried out simultaneously. This article critically reviews the current understanding of the operations and applications of SSHEs.

  7. Heat sterilization of wood

    Science.gov (United States)

    Xiping Wang

    2010-01-01

    Two important questions should be considered in heat sterilizing solid wood materials: First, what temperature–time regime is required to kill a particular pest? Second, how much time is required to heat the center of any wood configuration to the kill temperature? The entomology research on the first question has facilitated the development of international standards...

  8. Combined Heat and Power

    Science.gov (United States)

    CHP is on-site electricity generation that captures the heat that would otherwise be wasted to provide useful thermal energy such as steam or hot water than can be used for space heating, cooling, domestic hot water and industrial processes.

  9. Mesoscopic photon heat transistor

    DEFF Research Database (Denmark)

    Ojanen, T.; Jauho, Antti-Pekka

    2008-01-01

    We show that the heat transport between two bodies, mediated by electromagnetic fluctuations, can be controlled with an intermediate quantum circuit-leading to the device concept of a mesoscopic photon heat transistor (MPHT). Our theoretical analysis is based on a novel Meir-Wingreen-Landauer-typ......We show that the heat transport between two bodies, mediated by electromagnetic fluctuations, can be controlled with an intermediate quantum circuit-leading to the device concept of a mesoscopic photon heat transistor (MPHT). Our theoretical analysis is based on a novel Meir......-Wingreen-Landauer-type of conductance formula, which gives the photonic heat current through an arbitrary circuit element coupled to two dissipative reservoirs at finite temperatures. As an illustration we present an exact solution for the case when the intermediate circuit can be described as an electromagnetic resonator. We discuss...

  10. Graphene heat dissipating structure

    Energy Technology Data Exchange (ETDEWEB)

    Washburn, Cody M.; Lambert, Timothy N.; Wheeler, David R.; Rodenbeck, Christopher T.; Railkar, Tarak A.

    2017-08-01

    Various technologies presented herein relate to forming one or more heat dissipating structures (e.g., heat spreaders and/or heat sinks) on a substrate, wherein the substrate forms part of an electronic component. The heat dissipating structures are formed from graphene, with advantage being taken of the high thermal conductivity of graphene. The graphene (e.g., in flake form) is attached to a diazonium molecule, and further, the diazonium molecule is utilized to attach the graphene to material forming the substrate. A surface of the substrate is treated to comprise oxide-containing regions and also oxide-free regions having underlying silicon exposed. The diazonium molecule attaches to the oxide-free regions, wherein the diazonium molecule bonds (e.g., covalently) to the exposed silicon. Attachment of the diazonium plus graphene molecule is optionally repeated to enable formation of a heat dissipating structure of a required height.

  11. Heat tolerance in wheat

    DEFF Research Database (Denmark)

    Sharma, Dew Kumari

    climate, wheat is sensitive to heat stress. We need to understand how our crops will perform in these changing climatic conditions and how we can develop varieties, which are more tolerant. The PhD study focussed on understanding heat tolerance in wheat with a combined approach of plant physiology...... II (PSII), which is a fundamental process in photosynthesis. The first study was conducted to identify cultivars differing in Fv/Fm as a measure of heat tolerance during reproductive phase. The proportion of the total variation in cultivar Fv/Fm that was due to the genotypic difference was termed...... among cultivars due to heat stress as the GD of most of them remained similar in control and stress. The second study investigated if it was possible to use detached leaves to screen for heat tolerance instead of intact plants. The previously selected 41 cultivars, known to differ in v/Fm, were used...

  12. Experimental research on heat transfer of pulsating heat pipe

    Institute of Scientific and Technical Information of China (English)

    LI Jia; Yan Li

    2008-01-01

    Experimental research was conducted to understand heat transfer characteristic of pulsating heat pipe in this paper,and the PHP is made of high quality glass capillary tube. Under different fill ratio, heat transfer rate and many other influence factors, the flow patterns were observed in the start-up, transition and stable stage. The effects of heating position on heat transfer were discussed. The experimental results indicate that no annular flow appears in top heating condition. Under different fill ratios and heat transfer rate, the flow pattern in PHP is transferred from bulk flow to semi-annular flow and annular flow, and the performance of heat transfer is improved for down heating case. The experimental results indicate that the total heat resistant of PHP is increased with fill ratio, and heat transfer rate achieves optimum at filling rate 50%. But for pulsating heat pipe with changing diameters the thermal resistance is higher than that with uniform diameters.

  13. Heat pipe dynamic behavior

    Science.gov (United States)

    Issacci, F.; Roche, G. L.; Klein, D. B.; Catton, I.

    1988-01-01

    The vapor flow in a heat pipe was mathematically modeled and the equations governing the transient behavior of the core were solved numerically. The modeled vapor flow is transient, axisymmetric (or two-dimensional) compressible viscous flow in a closed chamber. The two methods of solution are described. The more promising method failed (a mixed Galerkin finite difference method) whereas a more common finite difference method was successful. Preliminary results are presented showing that multi-dimensional flows need to be treated. A model of the liquid phase of a high temperature heat pipe was developed. The model is intended to be coupled to a vapor phase model for the complete solution of the heat pipe problem. The mathematical equations are formulated consistent with physical processes while allowing a computationally efficient solution. The model simulates time dependent characteristics of concern to the liquid phase including input phase change, output heat fluxes, liquid temperatures, container temperatures, liquid velocities, and liquid pressure. Preliminary results were obtained for two heat pipe startup cases. The heat pipe studied used lithium as the working fluid and an annular wick configuration. Recommendations for implementation based on the results obtained are presented. Experimental studies were initiated using a rectangular heat pipe. Both twin beam laser holography and laser Doppler anemometry were investigated. Preliminary experiments were completed and results are reported.

  14. Acoustically enhanced heat transport

    Energy Technology Data Exchange (ETDEWEB)

    Ang, Kar M.; Hung, Yew Mun; Tan, Ming K., E-mail: tan.ming.kwang@monash.edu [School of Engineering, Monash University Malaysia, 47500 Bandar Sunway, Selangor (Malaysia); Yeo, Leslie Y. [Micro/Nanophysics Research Laboratory, RMIT University, Melbourne, VIC 3001 (Australia); Friend, James R. [Department of Mechanical and Aerospace Engineering, University of California, San Diego, California 92093 (United States)

    2016-01-15

    We investigate the enhancement of heat transfer in the nucleate boiling regime by inducing high frequency acoustic waves (f ∼ 10{sup 6} Hz) on the heated surface. In the experiments, liquid droplets (deionized water) are dispensed directly onto a heated, vibrating substrate. At lower vibration amplitudes (ξ{sub s} ∼ 10{sup −9} m), the improved heat transfer is mainly due to the detachment of vapor bubbles from the heated surface and the induced thermal mixing. Upon increasing the vibration amplitude (ξ{sub s} ∼ 10{sup −8} m), the heat transfer becomes more substantial due to the rapid bursting of vapor bubbles happening at the liquid-air interface as a consequence of capillary waves travelling in the thin liquid film between the vapor bubble and the air. Further increases then lead to rapid atomization that continues to enhance the heat transfer. An acoustic wave displacement amplitude on the order of 10{sup −8} m with 10{sup 6} Hz order frequencies is observed to produce an improvement of up to 50% reduction in the surface temperature over the case without acoustic excitation.

  15. Geothermal Heat Transfer

    Energy Technology Data Exchange (ETDEWEB)

    Basmajian, V.V.

    1986-01-28

    This patent describes a heat transfer apparatus which consists of: heat exchanging means for orientation in the earth below ground substantially vertically, having a hollow conduit of length from top to bottom much greater than the span across the hollow conduit orthogonal to its length with a top, bottom and an intermediate portion contiguous and communicating with the top and bottom portions for allowing thermally conductive fluid to flow freely between the top, intermediate and bottom portions for immersion in thermally conductive fluid in the region around the heat exchanging means for increasing the heat flow between the latter and earth when inserted into a substantially vertical borehole in the earth with the top portion above the bottom portion. The heat exchanger consists of heat exchanging conduit means in the intermediate portion for carrying refrigerant. The heat exchanging conduit consisting of tubes of thermally conductive material for carrying the refrigerant and extending along the length of the hollow conduit for a tube length that is less than the length of the hollow conduit. The hollow conduit is formed with port means between the top and the plurality of tubes for allowing the thermally conductive fluid to pass in a flow path embracing the tubes, the bottom portion, an outer channel around the hollow conduit and the port means.

  16. Acoustically enhanced heat transport

    Science.gov (United States)

    Ang, Kar M.; Yeo, Leslie Y.; Friend, James R.; Hung, Yew Mun; Tan, Ming K.

    2016-01-01

    We investigate the enhancement of heat transfer in the nucleate boiling regime by inducing high frequency acoustic waves (f ˜ 106 Hz) on the heated surface. In the experiments, liquid droplets (deionized water) are dispensed directly onto a heated, vibrating substrate. At lower vibration amplitudes (ξs ˜ 10-9 m), the improved heat transfer is mainly due to the detachment of vapor bubbles from the heated surface and the induced thermal mixing. Upon increasing the vibration amplitude (ξs ˜ 10-8 m), the heat transfer becomes more substantial due to the rapid bursting of vapor bubbles happening at the liquid-air interface as a consequence of capillary waves travelling in the thin liquid film between the vapor bubble and the air. Further increases then lead to rapid atomization that continues to enhance the heat transfer. An acoustic wave displacement amplitude on the order of 10-8 m with 106 Hz order frequencies is observed to produce an improvement of up to 50% reduction in the surface temperature over the case without acoustic excitation.

  17. Small particle heat exchangers

    Energy Technology Data Exchange (ETDEWEB)

    Hunt, A.J.

    1978-06-01

    A dispersion of small absorbing particles forms an ideal system to collect radiant energy, transform it to heat, and efficiently transfer the heat to a surrounding fluid. If the heated fluid is a pressurized gas, it can be passed through an expansion turbine to create useful mechanical energy. The most obvious application of this technique is its use in a solar collection system. In this case, the incoming sunlight is used to heat a compressed gas in an engine utilizing a Brayton cycle. The solar collection system may utilize high concentration as provided by a central receiver or parabolic dish, medium concentration from a linear collector, or possibly no concentration using a flat plate collector, if precautions were taken to reduce the heat losses. The same concept may be applied generally to non-solar heat exchangers. These may be of the type used to heat a gas from a combustion source, or in general as a gas to gas heat exchanger. The latter application may be limited to rather high temperature. Each of the above applications is discussed. First, a description of the concept is applied to a solar central-tower system. The general principles are described, including the optical and physical characteristics of the particles, the confinement of the gas-particle mixture, and the system considerations; the latter include the amount and type of particles, the receiver efficiency and the generation of the particles. The same considerations are reviewed for applications to linear trough and flat plate receivers. Finally, the use of small particles in non-solar heat exchangers is considered.

  18. Pioneering Heat Pump Project

    Energy Technology Data Exchange (ETDEWEB)

    Aschliman, Dave [Indiana Inst. of Technology, Inc., Fort Wayne, IN (United States); Lubbehusen, Mike [Indiana Inst. of Technology, Inc., Fort Wayne, IN (United States)

    2015-06-30

    This project was initiated at a time when ground coupled heat pump systems in this region were limited in size and quantity. There were economic pressures with costs for natural gas and electric utilities that had many organizations considering ground coupled heat pumps; The research has added to the understanding of how ground temperatures fluctuate seasonally and how this affects the performance and operation of the heat pumps. This was done by using a series of temperature sensors buried within the middle of one of the vertical bore fields with sensors located at various depths below grade. Trending of the data showed that there is a lag in ground temperature with respect to air temperatures in the shoulder months, however as full cooling and heating season arrives, the heat rejection and heat extraction from the ground has a significant effect on the ground temps; Additionally it is better understood that while a large community geothermal bore field serving multiple buildings does provide a convenient central plant to use, it introduces complexity of not being able to easily model and predict how each building will contribute to the loads in real time. Additional controllers and programming were added to provide more insight into this real time load profile and allow for intelligent shedding of load via a dry cooler during cool nights in lieu of rejecting to the ground loop. This serves as a means to ‘condition’ the ground loop and mitigate thermal creep of the field, as is typically observed; and It has been observed when compared to traditional heating and cooling equipment, there is still a cost premium to use ground source heat pumps that is driven mostly by the cost for vertical bore holes. Horizontal loop systems are less costly to install, but do not perform as well in this climate zone for heating mode

  19. Joule heating in nanowires

    Science.gov (United States)

    Fangohr, Hans; Chernyshenko, Dmitri S.; Franchin, Matteo; Fischbacher, Thomas; Meier, Guido

    2011-08-01

    We study the effect of Joule heating from electric currents flowing through ferromagnetic nanowires on the temperature of the nanowires and on the temperature of the substrate on which the nanowires are grown. The spatial current density distribution, the associated heat generation, and diffusion of heat are simulated within the nanowire and the substrate. We study several different nanowire and constriction geometries as well as different substrates: (thin) silicon nitride membranes, (thick) silicon wafers, and (thick) diamond wafers. The spatially resolved increase in temperature as a function of time is computed. For effectively three-dimensional substrates (where the substrate thickness greatly exceeds the nanowire length), we identify three different regimes of heat propagation through the substrate: regime (i), where the nanowire temperature increases approximately logarithmically as a function of time. In this regime, the nanowire temperature is well described analytically by You [Appl. Phys. Lett.APPLAB0003-695110.1063/1.2399441 89, 222513 (2006)]. We provide an analytical expression for the time tc that marks the upper applicability limit of the You model. After tc, the heat flow enters regime (ii), where the nanowire temperature stays constant while a hemispherical heat front carries the heat away from the wire and into the substrate. As the heat front reaches the boundary of the substrate, regime (iii) is entered, where the nanowire and substrate temperature start to increase rapidly. For effectively two-dimensional substrates (where the nanowire length greatly exceeds the substrate thickness), there is only one regime in which the temperature increases logarithmically with time for large times, before the heat front reaches the substrate boundary. We provide an analytical expression, valid for all pulse durations, that allows one to accurately compute this temperature increase in the nanowire on thin substrates.

  20. Industrial excess heat for district heating in Denmark

    DEFF Research Database (Denmark)

    Bühler, Fabian; Petrovic, Stefan; Karlsson, Kenneth Bernard

    2017-01-01

    the potential for using them for district heating. In this way the theoretical potential of using the excess heat for covering the heating demand of buildings is determined. Through the use of industry specific temperature profiles the heat usable directly or via heat pumps is further found. A sensitivity...... analysis investigates the impact of future energy efficiency measures in the industry, buildings and the district heating grid on the national potential. The results show that for the case study of Denmark, 1.36 TWh of district heat could be provided annually with industrial excess heat from thermal...

  1. Ventilation with heat recovery

    DEFF Research Database (Denmark)

    Tommerup, Henrik M.; Svendsen, Svend

    2005-01-01

    This paper presents the experiences from the use of ventilation with heat recovery in several experimental single-family houses developed and built within the last four years to meet the new Danish energy requirements of 2005. Included are descriptions of the ventilation system components...... and the main functional demands as well as measurements of the thermal efficiency, electricity consumptions and building air tightness. The paper addresses the aspects of minimizing the heat loss from the duct system and the heat recovery unit (when placed in an unheated attic space) in order to obtain...

  2. Heat treatment furnace

    Science.gov (United States)

    Seals, Roland D; Parrott, Jeffrey G; DeMint, Paul D; Finney, Kevin R; Blue, Charles T

    2014-10-21

    A furnace heats through both infrared radiation and convective air utilizing an infrared/purge gas design that enables improved temperature control to enable more uniform treatment of workpieces. The furnace utilizes lamps, the electrical end connections of which are located in an enclosure outside the furnace chamber, with the lamps extending into the furnace chamber through openings in the wall of the chamber. The enclosure is purged with gas, which gas flows from the enclosure into the furnace chamber via the openings in the wall of the chamber so that the gas flows above and around the lamps and is heated to form a convective mechanism in heating parts.

  3. Heat pump planning handbook

    CERN Document Server

    Bonin, Jürgen

    2015-01-01

    The Heat Pump Planning Handbook contains practical information and guidance on the design, planning and selection of heat pump systems, allowing engineers, designers, architects and construction specialists to compare a number of different systems and options. Including detailed descriptions of components and their functions and reflecting the current state of technology this guide contains sample tasks and solutions as well as new model calculations and planning evaluations. Also economic factors and alternative energy sources are covered, which are essential at a time of rising heat costs. T

  4. Ventilation with heat recovery

    DEFF Research Database (Denmark)

    Tommerup, Henrik M.; Svendsen, Svend

    2005-01-01

    and the main functional demands as well as measurements of the thermal efficiency, electricity consumptions and building air tightness. The paper addresses the aspects of minimizing the heat loss from the duct system and the heat recovery unit (when placed in an unheated attic space) in order to obtain......This paper presents the experiences from the use of ventilation with heat recovery in several experimental single-family houses developed and built within the last four years to meet the new Danish energy requirements of 2005. Included are descriptions of the ventilation system components...

  5. Sorption product heat pump

    Energy Technology Data Exchange (ETDEWEB)

    Antonini, G.; Francois, O.; Gendarme, J.P.; Guilleminot, J.J.; Meunier, F.

    1988-07-15

    A continuous operating, and thus with enhanced performance, heat pump is presented. In this heat pump, the heat transfer between the hot source and the output system or network is realized through a solid adsorbent-refrigerant couple having endothermal desorption properties and exothermal adsorption or absorption properties. The sorption products are carried in a closed cycle movement between the two parts of the reactor. Each side of the reactor is assuming always the same function and the thermal inertia have to be overcome only when starting the reactor.

  6. Probe tip heating assembly

    Science.gov (United States)

    Schmitz, Roger William; Oh, Yunje

    2016-10-25

    A heating assembly configured for use in mechanical testing at a scale of microns or less. The heating assembly includes a probe tip assembly configured for coupling with a transducer of the mechanical testing system. The probe tip assembly includes a probe tip heater system having a heating element, a probe tip coupled with the probe tip heater system, and a heater socket assembly. The heater socket assembly, in one example, includes a yoke and a heater interface that form a socket within the heater socket assembly. The probe tip heater system, coupled with the probe tip, is slidably received and clamped within the socket.

  7. Passive Solar Heating Residences.

    Science.gov (United States)

    1979-07-01

    temperatures of indes 1, 0, 8, and 7. Figure C-2 shows the rate of solair radiation absorption in node 1 (the prinnary solar heat souirce., the rate of...energy. The heating is basically done by letting the sun’s radiation into a building’s interior, to be stored in some kind of thermal mass or to heat up...solar radiation through south facing windows or clerestroies to be stored in the walls or floor of the house. Thermal storage in a wall or roof allows

  8. Heat exchanger design handbook

    CERN Document Server

    Thulukkanam, Kuppan

    2013-01-01

    Completely revised and updated to reflect current advances in heat exchanger technology, Heat Exchanger Design Handbook, Second Edition includes enhanced figures and thermal effectiveness charts, tables, new chapter, and additional topics--all while keeping the qualities that made the first edition a centerpiece of information for practicing engineers, research, engineers, academicians, designers, and manufacturers involved in heat exchange between two or more fluids.See What's New in the Second Edition: Updated information on pressure vessel codes, manufacturer's association standards A new c

  9. Electrohydrodynamic heat pipes.

    Science.gov (United States)

    Jones, T. B.

    1973-01-01

    An electrohydrodynamic heat pipe of radical design is proposed which substitutes polarization electrohydrodynamic force effects for capillarity in collecting, guiding, and pumping a condensate liquid phase. The discussed device is restricted to the use of dielectric liquids as working fluids. Because of the relatively poor thermal transport properties of these liquids, capillary heat pipes using these liquids have not been high performance devices. The employment of the electrohydrodynamic concept should enhance this performance and help fill the performance gap that exists in the temperature range from 250 F to 750 F for 'conventional' capillary heat pipes.

  10. Molecular heat pump.

    Science.gov (United States)

    Segal, Dvira; Nitzan, Abraham

    2006-02-01

    We propose a molecular device that pumps heat against a thermal gradient. The system consists of a molecular element connecting two thermal reservoirs that are characterized by different spectral properties. The pumping action is achieved by applying an external force that periodically modulates molecular levels. This modulation affects periodic oscillations of the internal temperature of the molecule and the strength of its coupling to each reservoir resulting in a net heat flow in the desired direction. The heat flow is examined in the slow and fast modulation limits and for different modulation wave forms, thus making it possible to optimize the device performance.

  11. Elementary heat transfer analysis

    CERN Document Server

    Whitaker, Stephen; Hartnett, James P

    1976-01-01

    Elementary Heat Transfer Analysis provides information pertinent to the fundamental aspects of the nature of transient heat conduction. This book presents a thorough understanding of the thermal energy equation and its application to boundary layer flows and confined and unconfined turbulent flows. Organized into nine chapters, this book begins with an overview of the use of heat transfer coefficients in formulating the flux condition at phase interface. This text then explains the specification as well as application of flux boundary conditions. Other chapters consider a derivation of the tra

  12. 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...

  13. Counterflow Regolith Heat Exchanger Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The counterflow regolith heat exchanger (CoRHE) is a device that transfers heat from hot regolith to cold regolith. The CoRHE is essentially a tube-in-tube heat...

  14. Digitized Heat Transfer

    Science.gov (United States)

    Mohseni, Kamran; Young, Patrick

    2007-11-01

    This presentation presents theoretical and numerical results describing digitized heat transfer (DHT), an active thermal management technique for high-power electronics and integrated micro systems. In digitized heat transfer discrete droplets are employed. The internal flow inside a discrete droplet is dominated by internal circulation imposed by the boundaries. This internal circulation imposes a new timescale for recirculating cold liquid from the middle of the droplet to the boundary. This internal circulation produces periodic oscillation in the overall convective heat transfer rate. Numerical simulations are presented for heat transfer in the droplet for both constant temperature and flux boundary conditions. The effectiveness of DHT for managing both localized temperature spikes and steady state cooling is demonstrated, identifying key parameters for optimization of the DHT method.

  15. Heat-Related Illnesses

    Medline Plus

    Full Text Available ... in Chesterfield, Missouri Heat-related illness can be caused by overexposure to the sun or any situation ... pale skin, rapid pulse, elevated or lowered blood pressure, nausea, loss of consciousness, vomiting or a high ...

  16. Condensation heat transfer

    Science.gov (United States)

    Rose, J. W.

    The paper gives a brief description of some of the better understood aspects of condensation heat transfer and includes discussion of the liquid-vapour interface, natural and forced convection laminar film condensation and dropwise condensation.

  17. Photothermal heating of nanoribbons

    Science.gov (United States)

    Smith, Bennett E.; Zhou, Xuezhe; Davis, E. James; Pauzauskie, Peter J.

    2017-01-01

    Nanoscale optical materials are of great interest for building future optoelectronic devices for information processing and sensing applications. Although heat transfer ultimately limits the maximum power at which nanoscale devices may operate, gaining a quantitative experimental measurement of photothermal heating within single nanostructures remains a challenge. Here, we measure the nonlinear optical absorption coefficient of optically trapped cadmium-sulfide nanoribbons at the level of single nanostructures through observations of their Brownian dynamics during single-beam laser trapping experiments. A general solution to the heat transfer partial differential equation is derived for nanostructures having rectilinear morphology including nanocubes and nanoribbons. Numerical electromagnetic calculations using the discrete-dipole approximation enable the simulation of the photothermal heating source function and the extraction of nonlinear optical absorption coefficients from experimental observations of single nanoribbon dynamics.

  18. Heat-Related Illnesses

    Medline Plus

    Full Text Available ... Medicine's Front Line Observation Emergency Care Fact Sheet Health & Safety Tips Campaigns SUBSCRIBE Emergencies A-Z Share ... Illnesses Dr. Glenn Mitchell , Emergency physician at Mercy Health System in Chesterfield, Missouri Heat-related illness can ...

  19. Analytical heat transfer

    CERN Document Server

    Han, Je-Chin

    2012-01-01

    … it will complete my library … [and] complement the existing literature on heat transfer. It will be of value for both graduate students and faculty members.-Bengt Sunden, Lund University, Sweden

  20. Advanced heat pump cycle

    Energy Technology Data Exchange (ETDEWEB)

    Groll, E.A.; Radermacher, R.

    1993-07-01

    The desorption and absorption process of a vapor compression heat pump with a solution circuit (VCHSC) proceeds at gliding temperature intervals, which can be adjusted over a wide range. In case that the gliding temperature intervals in the desorber and the absorber overlap, a modification of the VCHSC employing a desorber/absorber heat exchange (DAHX) can be introduced, which results in an extreme reduction of the pressure ratio. Although the DAHX-cycle has features of a two-stage cycle, it still requires only one solution pump, one separator and one compressor. Such a cycle for the working pair ammonia/water is built in the Energy Laboratory of the Center for Environmental Energy Engineering at the University of Maryland. The experimental results obtained with the research plant are discussed and compared to those calculated with a simulation program. The possible temperature lift between heat source and heat sink depending on the achievable COP are presented.

  1. Heat-Related Illnesses

    Medline Plus

    Full Text Available ... exhaustion symptoms include cool, moist, pale or flushed skin; headache; dizziness; weakness; feeling exhausted; heavy sweating; nausea; ... stage of heat illness) include flushed, hot, dry skin; fainting; a rapid, weak pulse; rapid, shallow breathing; ...

  2. Heat-Related Illnesses

    Medline Plus

    Full Text Available ... exhaustion symptoms include cool, moist, pale or flushed skin; headache; dizziness; weakness; feeling exhausted; heavy sweating; nausea; ... stage of heat illness) include flushed, hot, dry skin; fainting; a rapid, weak pulse; rapid, shallow breathing; ...

  3. Heat-Related Illnesses

    Medline Plus

    Full Text Available ... Health System in Chesterfield, Missouri Heat-related illness can be caused by overexposure to the sun or ... the elderly are most at risk, but anyone can be affected. Here you will find information about ...

  4. Heat Island Compendium

    Science.gov (United States)

    Heat islands can be mitigated through measures like planting trees and vegetation, installing green roofs and cool roofs, and using cool pavements. The compendium describes all of these strategies and shows how communities around the country are being used

  5. Chiral brownian heat pump.

    Science.gov (United States)

    van den Broek, M; Van den Broeck, C

    2008-04-04

    We present the exact analysis of a chiral Brownian motor and heat pump. Optimization of the construction predicts, for a nanoscale device, frequencies of the order of kHz and cooling rates of the order of femtojoule per second.

  6. Chiral Brownian heat pump

    OpenAIRE

    Van Den Broek, Martijn; Van Den Broeck, Christian

    2007-01-01

    We present the exact analysis of a chiral Brownian motor and heat pump. Optimization of the construction predicts, for a nanoscale device, frequencies of the order of kHz and cooling rates of the order of femtojoule per second.

  7. Microplate Heat Exchanger Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose a microplate heat exchanger for cryogenic cooling systems used for continuous flow distributed cooling systems, large focal plane arrays, multiple cooling...

  8. Radiative heat transfer

    CERN Document Server

    Modest, Michael F

    2013-01-01

    The third edition of Radiative Heat Transfer describes the basic physics of radiation heat transfer. The book provides models, methodologies, and calculations essential in solving research problems in a variety of industries, including solar and nuclear energy, nanotechnology, biomedical, and environmental. Every chapter of Radiative Heat Transfer offers uncluttered nomenclature, numerous worked examples, and a large number of problems-many based on real world situations-making it ideal for classroom use as well as for self-study. The book's 24 chapters cover the four major areas in the field: surface properties; surface transport; properties of participating media; and transfer through participating media. Within each chapter, all analytical methods are developed in substantial detail, and a number of examples show how the developed relations may be applied to practical problems. It is an extensive solution manual for adopting instructors. Features: most complete text in the field of radiative heat transfer;...

  9. Heat and mass transfer

    CERN Document Server

    Karwa, Rajendra

    2017-01-01

    This textbook presents the classical treatment of the problems of heat transfer in an exhaustive manner with due emphasis on understanding of the physics of the problems. This emphasis is especially visible in the chapters on convective heat transfer. Emphasis is laid on the solution of steady and unsteady two-dimensional heat conduction problems. Another special feature of the book is a chapter on introduction to design of heat exchangers and their illustrative design problems. A simple and understandable treatment of gaseous radiation has been presented. A special chapter on flat plate solar air heater has been incorporated that covers thermo-hydraulic modeling and simulation. The chapter on mass transfer has been written looking specifically at the needs of the students of mechanical engineering. The book includes a large number and variety of solved problems with supporting line diagrams. The author has avoided duplicating similar problems, while incorporating more application-based examples. All the end-...

  10. Policies for Renewable Heat

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-07-01

    This paper builds on IEA publications, Deploying Renewables, Principles for Effective Policies and Deploying Renewables, Best and Future Policy Practice, that discuss the 'integrated policy approach,' whereby renewable energy technologies require different support policies at different stages of their maturity pathways. The paper discusses how the integrated policy approach applies to renewable heat. It attempts to provide guidance for policy-makers on renewable heat throughout the different phases of the policy lifecycle, allowing for the specific challenges of renewable heat and needs of the many stakeholders involved. Stimulating a market for heat involves challenges that are different and, often, more difficult to overcome than in the electricity and transport sectors.

  11. Optimal design of the separate type heat pipe heat exchanger

    Institute of Scientific and Technical Information of China (English)

    YU Zi-tao; HU Ya-cai; CEN Ke-fa

    2005-01-01

    Separate type heat pipe heat exchangers are often used for large-scale heat exchanging. The arrangement of such a heat exchanger conveniently allows heat input to and output from the heat exchanger at remote locations. The traditional method of designing an ordinary HPHE (heat pipe heat exchanger) is commonly applied in the separate type exchanger design, but the calculations have to be carried out separately, which makes it very complicated. In this work, the ε-NTU (effectiveness-Number of Transfer Units) method was applied for optimization analysis of single- or multi-level separate type heat pipe heat exchangers. An optimizing formula for single-level separate type heat pipe heat exchangers was obtained. The optimizing principles of effectiveness-NTU and heat transfer rate by the equal distribution method for multi-level separate type heat pipe heat exchanger are presented. The design of separate type heat pipe heat exchangers by the optimizing method is more convenient and faster than by the traditional method.

  12. NGNP Process Heat Utilization: Liquid Metal Phase Change Heat Exchanger

    Energy Technology Data Exchange (ETDEWEB)

    Piyush Sabharwall; Mike Patterson; Vivek Utgikar; Fred Gunnerson

    2008-09-01

    One key long-standing issue that must be overcome to fully realize the successful growth of nuclear power is to determine other benefits of nuclear energy apart from meeting the electricity demands. The Next Generation Nuclear Plant (NGNP) will most likely be producing electricity and heat for the production of hydrogen and/or oil retrieval from oil sands and oil shale to help in our national pursuit of energy independence. For nuclear process heat to be utilized, intermediate heat exchange is required to transfer heat from the NGNP to the hydrogen plant or oil recovery field in the most efficient way possible. Development of nuclear reactor - process heat technology has intensified the interest in liquid metals as heat transfer media because of their ideal transport properties. Liquid metal heat exchangers are not new in practical applications. An important rational for considering liquid metals is the potential convective heat transfer is among the highest known. Thus explains the interest in liquid metals as coolant for intermediate heat exchange from NGNP. For process heat it is desired that, intermediate heat exchangers (IHX) transfer heat from the NGNP in the most efficient way possible. The production of electric power at higher efficiency via the Brayton Cycle, and hydrogen production, requires both heat at higher temperatures and high effectiveness compact heat exchangers to transfer heat to either the power or process cycle. Compact heat exchangers maximize the heat transfer surface area per volume of heat exchanger; this has the benefit of reducing heat exchanger size and heat losses. High temperature IHX design requirements are governed in part by the allowable temperature drop between the outlet and inlet of the NGNP. In order to improve the characteristics of heat transfer, liquid metal phase change heat exchangers may be more effective and efficient. This paper explores the overall heat transfer characteristics and pressure drop of the phase change

  13. Thermal radiation heat transfer

    CERN Document Server

    Howell, John R; Siegel, Robert

    2016-01-01

    Further expanding on the changes made to the fifth edition, Thermal Radiation Heat Transfer, 6th Edition continues to highlight the relevance of thermal radiative transfer and focus on concepts that develop the radiative transfer equation (RTE). The book explains the fundamentals of radiative transfer, introduces the energy and radiative transfer equations, covers a variety of approaches used to gauge radiative heat exchange between different surfaces and structures, and provides solution techniques for solving the RTE.

  14. Superradiant Quantum Heat Engine

    OpenAIRE

    Ali Ü. C. Hardal; Müstecaplıoğlu, Özgür E.

    2015-01-01

    Scientific Reports | 5:12953 | DOI: 10.1038/srep12953 1 www.nature.com/scientificreports Superradiant Quantum Heat Engine Ali Ü. C. Hardal & Özgür E. Müstecaplıoğlu Quantum physics revolutionized classical disciplines of mechanics, statistical physics, and electrodynamics. One branch of scientific knowledge however seems untouched: thermodynamics. Major motivation behind thermodynamics is to develop eficient heat engines. Technology has a trend to miniaturize engines, ...

  15. Heat exchange apparatus

    Science.gov (United States)

    Degtiarenko, Pavel V.

    2003-08-12

    A heat exchange apparatus comprising a coolant conduit or heat sink having attached to its surface a first radial array of spaced-apart parallel plate fins or needles and a second radial array of spaced-apart parallel plate fins or needles thermally coupled to a body to be cooled and meshed with, but not contacting the first radial array of spaced-apart parallel plate fins or needles.

  16. Heat-Related Illnesses

    Science.gov (United States)

    1988-04-01

    to cold stress. Despite this ability, man has been plagued by heat illness throughout recorded history. The Old Testament describes a young man’s...encounter heat illness because of the requirement to train unacclimatized men by means of forced heavy physical cxercise. The United States Army...dyspnea, dysphagia , and urinary incontinence. 2 6 Although the muscular rigidity and hyperthermia are reminiscent of malignant hyperthermia, the putative

  17. Heat Pipe Systems

    Science.gov (United States)

    1988-01-01

    Solar Fundamentals, Inc.'s hot water system employs space-derived heat pipe technology. It is used by a meat packing plant to heat water for cleaning processing machinery. Unit is complete system with water heater, hot water storage, electrical controls and auxiliary components. Other than fans and a circulating pump, there are no moving parts. System's unique design eliminates problems of balancing, leaking, corroding, and freezing.

  18. Comparison of heat transfer efficiency between heat pipe and tube bundles heat exchanger

    Directory of Open Access Journals (Sweden)

    Wu Zhao-Chun

    2015-01-01

    Full Text Available A comparison of heat transfer efficiency between the heat pipe and tube bundles heat exchanger is made based on heat transfer principle and the analysis of thermal characteristics. This paper argues that although heat pipe has the feature of high axial thermal conductivity, to those cases where this special function of heat transfer is unnecessary, heat pipe exchanger is not a high efficient heat exchanger when it is just used as a conventional heat exchanger in the industrial fields. In turn, there are some deficiencies for heat pipe exchanger, such as complicated manufacturing process, critical requirements for manufacturing materials, etc. which leads to a higher cost in comparison to a tubular heat exchanger. Nonetheless, due to its diverse structural features and extraordinary properties, heat pipe exchanger still has wide applications on special occasions.

  19. Critical heat flux thermodynamics

    Energy Technology Data Exchange (ETDEWEB)

    Collado, F.J. E-mail: fjk@posta.unizar.es

    2002-11-01

    Convective boiling in subcooled water flowing through a heated channel is essential in many engineering applications where high heat flux need to be accommodated, such as in the divertor plates of fusion reactors. There are many available correlations for predicting heat transfer in the individual regimes of the empirical Nukiyama boiling curve, although unfortunately there is no physical fundamentals of such curve. Recently, the author has shown that the classical entropy balance could contain key information about boiling heat transfer. So, it was found that the average thermal gap in the heated channel (the wall temperature minus the average temperature of the coolant fluid) was strongly correlated with the efficiency of a theoretical reversible engine placed in this thermal gap. In this work and from the new proposed correlation, a new expression of the wall temperature in function of the average fluid temperature is derived and successfully checked against experimental data from General Electric. This expression suggests a new and simple definition of the critical heat flux (CHF), a key parameter of the thermal-hydraulic design of fusion reactors. Finally, based on the new definition, the CHF trends are commented.

  20. Heat transfer interface between a high temperature heat source and a heat sink

    Energy Technology Data Exchange (ETDEWEB)

    du Pre, F.K.; Jaspers, H.A.

    1977-10-11

    A heat-transfer interface between and separating a high temperature heat source and a heat sink is formed by the adjacent walls of the heat source and heat sink with a thin gap between these walls and helium gas sealed in the gap, the walls preferably defining concentric hemispheres; this interface being particularly feasible as separable walls of the heater portion of a Stirling engine and a heat source.

  1. Utilization of heat pipes for transfer heat from the flue gas into the heat transfer medium

    Directory of Open Access Journals (Sweden)

    Lenhard Richard

    2014-03-01

    Full Text Available The contribution is listed possible application of heat pipes in systems for obtaining heat from flue gas of small heat sources. It is also stated in the contribution design an experimental device on which to study the impact of fill (the quantity, type of load at various temperature parameters (temperature heating and cooling thermal power transferred to the heat pipe. Is listed measurement methodology using heat pipes designed experimental facility, measurement results and analysis of the results obtained.

  2. Heat exchanger device and method for heat removal or transfer

    Science.gov (United States)

    Koplow, Jeffrey P [San Ramon, CA

    2012-07-24

    Systems and methods for a forced-convection heat exchanger are provided. In one embodiment, heat is transferred to or from a thermal load in thermal contact with a heat conducting structure, across a narrow air gap, to a rotating heat transfer structure immersed in a surrounding medium such as air.

  3. Heat exchanger device and method for heat removal or transfer

    Science.gov (United States)

    Koplow, Jeffrey P

    2013-12-10

    Systems and methods for a forced-convection heat exchanger are provided. In one embodiment, heat is transferred to or from a thermal load in thermal contact with a heat conducting structure, across a narrow air gap, to a rotating heat transfer structure immersed in a surrounding medium such as air.

  4. Role of radiogenic heat generation in surface heat flow formation

    Science.gov (United States)

    Khutorskoi, M. D.; Polyak, B. G.

    2016-03-01

    Heat generation due to decay of long-lived radioactive isotopes is considered in the Earth's crust of the Archean-Proterozoic and Paleozoic provinces of Eurasia and North America. The heat flow that forms in the mantle is calculated as the difference between the heat flow observed at the boundary of the solid Earth and radiogenic heat flow produced in the crust. The heat regime in regions with anomalously high radiogenic heat generation is discussed. The relationship between various heat flow components in the Precambrian and Phanerozoic provinces has been comparatively analyzed, and the role of erosion of the surfaceheat- generating layer has been estimated.

  5. 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.

  6. Fault-Tolerant Heat Exchanger

    Science.gov (United States)

    Izenson, Michael G.; Crowley, Christopher J.

    2005-01-01

    A compact, lightweight heat exchanger has been designed to be fault-tolerant in the sense that a single-point leak would not cause mixing of heat-transfer fluids. This particular heat exchanger is intended to be part of the temperature-regulation system for habitable modules of the International Space Station and to function with water and ammonia as the heat-transfer fluids. The basic fault-tolerant design is adaptable to other heat-transfer fluids and heat exchangers for applications in which mixing of heat-transfer fluids would pose toxic, explosive, or other hazards: Examples could include fuel/air heat exchangers for thermal management on aircraft, process heat exchangers in the cryogenic industry, and heat exchangers used in chemical processing. The reason this heat exchanger can tolerate a single-point leak is that the heat-transfer fluids are everywhere separated by a vented volume and at least two seals. The combination of fault tolerance, compactness, and light weight is implemented in a unique heat-exchanger core configuration: Each fluid passage is entirely surrounded by a vented region bridged by solid structures through which heat is conducted between the fluids. Precise, proprietary fabrication techniques make it possible to manufacture the vented regions and heat-conducting structures with very small dimensions to obtain a very large coefficient of heat transfer between the two fluids. A large heat-transfer coefficient favors compact design by making it possible to use a relatively small core for a given heat-transfer rate. Calculations and experiments have shown that in most respects, the fault-tolerant heat exchanger can be expected to equal or exceed the performance of the non-fault-tolerant heat exchanger that it is intended to supplant (see table). The only significant disadvantages are a slight weight penalty and a small decrease in the mass-specific heat transfer.

  7. Heat Pipe Blocks Return Flow

    Science.gov (United States)

    Eninger, J. E.

    1982-01-01

    Metal-foil reed valve in conventional slab-wick heat pipe limits heat flow to one direction only. With sink warmer than source, reed is forced closed and fluid returns to source side through annular transfer wick. When this occurs, wick slab on sink side of valve dries out and heat pipe ceases to conduct heat.

  8. Liquid/liquid heat exchanger

    Science.gov (United States)

    Miller, C. G.

    1980-01-01

    Conceptual design for heat exchanger, utilizing two immiscible liquids with dissimilar specific gravities in direct contact, is more efficient mechanism of heat transfer than conventional heat exchangers with walls or membranes. Concept could be adapted for collection of heat from solar or geothermal sources.

  9. Structures to radiate heat softly

    Energy Technology Data Exchange (ETDEWEB)

    Perilae, T.; Wikstroem, T. [ed.

    1997-11-01

    Over the past fifty years, heating systems in single-family houses have taken a great leap forward. First wood-burning stoves gave way to oil heaters; then these were superseded by central heating systems; and now conventional central heating systems have lost their way with the increasingly widespread use of room-specific heating systems

  10. Experiments Demonstrate Geothermal Heating Process

    Science.gov (United States)

    Roman, Harry T.

    2012-01-01

    When engineers design heat-pump-based geothermal heating systems for homes and other buildings, they can use coil loops buried around the perimeter of the structure to gather low-grade heat from the earth. As an alternative approach, they can drill well casings and store the summer's heat deep in the earth, then bring it back in the winter to warm…

  11. Kajian Eksperimen Heat Exchahger Pada Heat Pump Menggunakan Refrijeran Hidrokarbon

    Directory of Open Access Journals (Sweden)

    Kusnandar

    2016-03-01

    Full Text Available Heat pump or usually known as pump energy is a device that can cooling and heating to be used, which functions as a cooling evaporator can be direct replace to heating as a function of the condenser using a reversing valve.. Using heat exchangers in the heat pump system is installed on the suction line and discharge line, so it will give the suction line temperature changes will be higher and discharge line temperatures will be lower, resulting in a greater cooling effect and lighter work of compression. The heat pump uses refrigerant type of hydrocarbon that is friendly to the environment, such as refrigerant R-290. From the results obtained research that the highest of Coefficient of Performance (COP in the heat pump using heat exchangers is 4.8 and without using heat exchanger is 4.1. So value of COP of haet pump between using heat exchanger and withaout heat exchanger is 0.7. The highest efficiency obtained on the heat pump using heat exchangers is 90.3%, and efficiency of heat pump without using heat exchanger is 78.95%.

  12. Heat exchanger restart evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Morrison, J.M.; Hirst, C.W.; Lentz, T.F.

    1992-02-28

    On December 24, 1991, the K-Reactor was in the shutdown mode with full AC process water flow and full cooling water flow. Safety rod testing was being performed as part of the power ascension testing program. The results of cooling water samples indicated tritium concentrations higher than allowable. Further sampling and testing confirmed a Process Water System to Cooling Water System leak in heat exchanger 4A (HX 4A). The heat exchanger was isolated and the plant shutdown. Heat exchanger 4kA was removed from the plant and moved to C-Area prior to performing examinations and diagnostic testing. This included locating and identifying the leaking tube or tubes, eddy current examination of the leaking tube and a number of adjacent tubes, visually inspecting the leaking tube from both the inside as well as the area surrounding the failure mechanism. In addition ten other tubes that either exhibited eddy current indications or would represent a baseline condition were removed from heat exchanger 4A for metallurgical examination. Additional analysis and review of heat exchanger leakage history was performed to determine if there are any patterns which can be used for predictive purposes. Compensatory actions have been taken to improve the sensitivity and response time to any future events of this type. The results of these actions are summarized herein.

  13. Heat-pipe planets

    Science.gov (United States)

    Moore, William B.; Simon, Justin I.; Webb, A. Alexander G.

    2017-09-01

    Observations of the surfaces of all terrestrial bodies other than Earth reveal remarkable but unexplained similarities: endogenic resurfacing is dominated by plains-forming volcanism with few identifiable centers, magma compositions are highly magnesian (mafic to ultra-mafic), tectonic structures are dominantly contractional, and ancient topographic and gravity anomalies are preserved to the present. Here we show that cooling via volcanic heat pipes may explain these observations and provide a universal model of the way terrestrial bodies transition from a magma-ocean state into subsequent single-plate, stagnant-lid convection or plate tectonic phases. In the heat-pipe cooling mode, magma moves from a high melt-fraction asthenosphere through the lithosphere to erupt and cool at the surface via narrow channels. Despite high surface heat flow, the rapid volcanic resurfacing produces a thick, cold, and strong lithosphere which undergoes contractional strain forced by downward advection of the surface toward smaller radii. We hypothesize that heat-pipe cooling is the last significant endogenic resurfacing process experienced by most terrestrial bodies in the solar system, because subsequent stagnant-lid convection produces only weak tectonic deformation. Terrestrial exoplanets appreciably larger than Earth may remain in heat-pipe mode for much of the lifespan of a Sun-like star.

  14. Multileg Heat-Pipe Evaporator

    Science.gov (United States)

    Alario, J. P.; Haslett, R. A.

    1986-01-01

    Parallel pipes provide high heat flow from small heat exchanger. Six parallel heat pipes extract heat from overlying heat exchanger, forming evaporator. Vapor channel in pipe contains wick that extends into screen tube in liquid channel. Rods in each channel hold wick and screen tube in place. Evaporator compact rather than extended and more compatible with existing heat-exchanger geometries. Prototype six-pipe evaporator only 0.3 m wide and 0.71 m long. With ammonia as working fluid, transports heat to finned condenser at rate of 1,200 W.

  15. Intensification of Convective Heat Transfer in Heating Device of Mobile Heating System with BH-Heat Generator

    Directory of Open Access Journals (Sweden)

    N. Nesenchuk

    2013-01-01

    Full Text Available Directions pertaining to intensification of convective heat transfer in a soft heating device have been experimentally investigated  in the paper and the most efficient one has been selected that is creation of artificial roughness on the device surface. The considered heating device for a heat supply system of a mobile object has been made of soft polymer material (polyvinyl chloride. Following  evaluation results of  heat exchange intensification a criteria equation has been obtained for calculation of external heat transfer with due account of heat transfer intensification.

  16. Heat transfer fluids containing nanoparticles

    Science.gov (United States)

    Singh, Dileep; Routbort, Jules; Routbort, A.J.; Yu, Wenhua; Timofeeva, Elena; Smith, David S.; France, David M.

    2016-05-17

    A nanofluid of a base heat transfer fluid and a plurality of ceramic nanoparticles suspended throughout the base heat transfer fluid applicable to commercial and industrial heat transfer applications. The nanofluid is stable, non-reactive and exhibits enhanced heat transfer properties relative to the base heat transfer fluid, with only minimal increases in pumping power required relative to the base heat transfer fluid. In a particular embodiment, the plurality of ceramic nanoparticles comprise silicon carbide and the base heat transfer fluid comprises water and water and ethylene glycol mixtures.

  17. Solar district heating system `Schillerstrasse` in Schwaebisch-Gmuend; Solare Nahwaerme ``Schillerstrasse`` in Schwaebisch Gmuend

    Energy Technology Data Exchange (ETDEWEB)

    Kuebler, R. [Steinbeis-Transferzentrum Energie-, Gebaeude- und Solartechnik, Stuttgart (Germany); Mangold, D. [Stuttgart Univ. (Germany). Inst. fuer Thermodynamik und Waermetechnik

    1998-12-31

    The construction project Schillerstrasse in Schwaebisch-Gmuend was planned and realised by the Siedlungswerk Stuttgart from 1993 until 1996. Like in earlier projects in Ravensburg and Koengen the Siedlungswerk wanted to use new technologies in the field of thermal insulation and heat supply at the construction of this new residential area in order to stay considerably below the former construction standards (WSVO 1982). One part of this energy concept is a large solar plant to support warm water supply. Good experience had been made with flat solar collectors at the three plants in Ravensburg and Koengen. In Schwaebisch-Gmuend vacuum pipe collectors were utilised for the first time. They were the only type of collectors which could be installed on the flat roofs without being visible from the ground. The solar-assisted district heating system was put in operation in May 1996. A new method that controls the system by measuring data acquisition enabled to measure and optimise the thermal performance of the plant. At the beginning of 1998 the plant was modified in order to improve the use of the solar plant. (orig.) [Deutsch] Das Bauvorhaben Schillerstrasse in Schwaebisch Gmuend wurde in den Jahren 1993-1996 vom Siedlungswerk Stuttgart geplant und gebaut. Aehnlich wie bei frueheren Projekten in Ravensburg und Koengen war es das Ziel des Siedlungswerks, in diesem Neubauvorhaben neue Wege beim Waermeschutz und bei der Waermeversorgung der Wohnanlage zu gehen, um den damaligen Baustandard (WSVO 1982) deutlich zu unterschreiten. Ein Element dieses Energiekonzepts ist eine grosse Solaranlage zur Unterstuetzung der Warmwasserbereitung. Nach guten Erfahrungen mit Flachkollektoren in den drei Anlagen in Ravensburg und Koengen wurden in Schwaebisch Gmuend zum ersten Mal Vakuum-Roehrenkollektoren eingesetzt. Fuer die Wahl der Vakuumroehren waren nicht zuletzt die stadtpolitischen Randbedingungen ausschlaggebend, die nur eine von unten nicht sichtbare Aufstellung auf dem

  18. Gravity heats the Universe

    CERN Document Server

    Moss, Adam

    2009-01-01

    Structure in the Universe grew through gravitational instability from very smooth initial conditions. Energy conservation requires that the growing negative potential energy of these structures is balanced by an increase in kinetic energy. A fraction of this is converted into heat in the collisional gas of the intergalactic medium. Using a toy model of gravitational heating we attempt to link the growth of structure in the Universe and the average temperature of this gas. We find that the gas is rapidly heated from collapsing structures at around $z {\\sim} 10$, reaching a temperature ${>} 10^6$K today, depending on some assumptions of our simplified model. Before that there was a cold era from $z\\sim100$ to $\\sim10$ in which the matter temperature is below that of the Cosmic Microwave Background.

  19. Heat and mass transfer

    CERN Document Server

    Baehr, Hans Dieter

    2011-01-01

    This comprehensive textbook provides a solid foundation of knowledge on the principles of heat and mass transfer and shows how to solve problems by applying modern methods. The basic theory is developed systematically, exploring in detail the solution methods to all important problems.   The thoroughly revised 3rd edition includes an introduction to the numerical solution of Finite Elements. A new section on heat and mass transfer in porous media has also been added.   The book will be useful not only to upper-level and graduate students, but also to practicing scientists and engineers, offering a firm understanding of the principles of heat and mass transfer, and showing how to solve problems by applying modern methods. Many completed examples and numerous exercises with solutions facilitate learning and understanding, and an appendix includes data on key properties of important substances.

  20. Thermal radiation heat transfer

    CERN Document Server

    Howell, John R; Mengüç, M Pinar

    2011-01-01

    Providing a comprehensive overview of the radiative behavior and properties of materials, the fifth edition of this classic textbook describes the physics of radiative heat transfer, development of relevant analysis methods, and associated mathematical and numerical techniques. Retaining the salient features and fundamental coverage that have made it popular, Thermal Radiation Heat Transfer, Fifth Edition has been carefully streamlined to omit superfluous material, yet enhanced to update information with extensive references. Includes four new chapters on Inverse Methods, Electromagnetic Theory, Scattering and Absorption by Particles, and Near-Field Radiative Transfer Keeping pace with significant developments, this book begins by addressing the radiative properties of blackbody and opaque materials, and how they are predicted using electromagnetic theory and obtained through measurements. It discusses radiative exchange in enclosures without any radiating medium between the surfaces-and where heat conduction...

  1. Heat tolerance in wheat

    DEFF Research Database (Denmark)

    Sharma, Dew Kumari

    among cultivars due to heat stress as the GD of most of them remained similar in control and stress. The second study investigated if it was possible to use detached leaves to screen for heat tolerance instead of intact plants. The previously selected 41 cultivars, known to differ in v/Fm, were used....... The main difference between the detached leaves and intact plant was the vast difference in time scale of reaction and the severity of heat stress. All the chlorophyll fluorescence parameters remained almost unaffected in control, indicating that the detachment itself did not cause the difference....... The correlation of the cultivar response in intact plant versus detached leaf was low. Overall, the result suggests that selection of cultivars by detached leaves may operate for different genetic factors than in intact plants. In the third study, the previously selected high and low groups of cultivars (from...

  2. Artificial muscles on heat

    Science.gov (United States)

    McKay, Thomas G.; Shin, Dong Ki; Percy, Steven; Knight, Chris; McGarry, Scott; Anderson, Iain A.

    2014-03-01

    Many devices and processes produce low grade waste heat. Some of these include combustion engines, electrical circuits, biological processes and industrial processes. To harvest this heat energy thermoelectric devices, using the Seebeck effect, are commonly used. However, these devices have limitations in efficiency, and usable voltage. This paper investigates the viability of a Stirling engine coupled to an artificial muscle energy harvester to efficiently convert heat energy into electrical energy. The results present the testing of the prototype generator which produced 200 μW when operating at 75°C. Pathways for improved performance are discussed which include optimising the electronic control of the artificial muscle, adjusting the mechanical properties of the artificial muscle to work optimally with the remainder of the system, good sealing, and tuning the resonance of the displacer to minimise the power required to drive it.

  3. Elements of heat transfer

    CERN Document Server

    Rathakrishnan, Ethirajan

    2012-01-01

    1 Basic Concepts and Definitions1.1 Introduction1.1.1 Driving Potential1.2 Dimensions and Units1.2.1 Dimensional Homogeneity1.3 Closed and Open Systems1.3.1 Closed System (ControlMass)1.3.2 Isolated System1.3.3 Open System (ControlVolume)1.4 Forms of Energy1.4.1 Internal Energy1.5 Properties of a System1.5.1 Intensive and Extensive Properties1.6 State and Equilibrium1.7 Thermal and Calorical Properties1.7.1 Specific Heat of an Incompressible Substance1.7.2 Thermally Perfect Gas 1.8 The Perfect Gas1.9 Summary1.10 Exercise ProblemsConduction Heat Transfer2.1 Introduction2.2 Conduction Heat Trans

  4. Induction heating coupler

    Science.gov (United States)

    Fox, Robert L. (Inventor); Copeland, Carl E. (Inventor); Swaim, Robert J. (Inventor); Coultrip, Robert H. (Inventor); Johnston, David F. (Inventor); Phillips, W. Morris (Inventor); Johnson, Samuel D. (Inventor); Dinkins, James R. (Inventor); Buckley, John D. (Inventor)

    1994-01-01

    An induction heating device includes a handle having a hollow interior and two opposite ends, a wrist connected to one end of the handle, a U-shaped pole piece having two spaced apart ends, a tank circuit including an induction coil wrapped around the pole piece and a capacitor connected to the induction coil, a head connected to the wrist and including a housing for receiving the U-shaped pole piece, the two spaced apart ends of the pole piece extending outwardely beyond the housing, and a power source connected to the tank circuit. When the tank circuit is energized and a susceptor is placed in juxtaposition to the ends of the U-shaped pole piece, the susceptor is heated by induction heating due to magnetic flux passing between the two ends of the pole piece.

  5. Large Scale Solar Heating

    DEFF Research Database (Denmark)

    Heller, Alfred

    2001-01-01

    The main objective of the research was to evaluate large-scale solar heating connected to district heating (CSDHP), to build up a simulation tool and to demonstrate the application of the simulation tool for design studies and on a local energy planning case. The evaluation was mainly carried out...... model is designed and validated on the Marstal case. Applying the Danish Reference Year, a design tool is presented. The simulation tool is used for proposals for application of alternative designs, including high-performance solar collector types (trough solar collectors, vaccum pipe collectors......). Simulation programs are proposed as control supporting tool for daily operation and performance prediction of central solar heating plants. Finaly the CSHP technolgy is put into persepctive with respect to alternatives and a short discussion on the barries and breakthrough of the technology are given....

  6. Electrochemical heat engine

    Science.gov (United States)

    Elliott, Guy R. B.; Holley, Charles E.; Houseman, Barton L.; Sibbitt, Jr., Wilmer L.

    1978-01-01

    Electrochemical heat engines produce electrochemical work, and mechanical motion is limited to valve and switching actions as the heat-to-work cycles are performed. The electrochemical cells of said heat engines use molten or solid electrolytes at high temperatures. One or more reactions in the cycle will generate a gas at high temperature which can be condensed at a lower temperature with later return of the condensate to electrochemical cells. Sodium, potassium, and cesium are used as the working gases for high temperature cells (above 600 K) with halogen gases or volatile halides being used at lower temperature. Carbonates and halides are used as molten electrolytes and the solid electrolyte in these melts can also be used as a cell separator.

  7. Microgravity condensing heat exchanger

    Science.gov (United States)

    Thomas, Christopher M. (Inventor); Ma, Yonghui (Inventor); North, Andrew (Inventor); Weislogel, Mark M. (Inventor)

    2011-01-01

    A heat exchanger having a plurality of heat exchanging aluminum fins with hydrophilic condensing surfaces which are stacked and clamped between two cold plates. The cold plates are aligned radially along a plane extending through the axis of a cylindrical duct and hold the stacked and clamped portions of the heat exchanging fins along the axis of the cylindrical duct. The fins extend outwardly from the clamped portions along approximately radial planes. The spacing between fins is symmetric about the cold plates, and are somewhat more closely spaced as the angle they make with the cold plates approaches 90.degree.. Passageways extend through the fins between vertex spaces which provide capillary storage and communicate with passageways formed in the stacked and clamped portions of the fins, which communicate with water drains connected to a pump externally to the duct. Water with no entrained air is drawn from the capillary spaces.

  8. Technology assessment heat pumps

    Energy Technology Data Exchange (ETDEWEB)

    Rudolph, R.; Purper, G. (Battelle-Institut e.V., Frankfurt am Main (Germany, F.R.))

    Technology assessment for an increased application of heat pumps is carried out in four areas: Effects in the economics area, i.e. effects on the economic goals which are defined in the Stability Law, on the goals of the power supply policy which result from the energy programme and its projections, and on the economic structure as a whole. The whole range of social problems concerning the use of heat pumps, i.e. the questions which social groups are affected, how they react, and what consequences are they expected to have on energy conservation as an object of social policy. Consequences in the governmental and administrative sectors, i.e. effects on legislation, administration and government budgets. Effects on the ecological systems; of prime interest in this context are the utilisation of environmental energy, changes in the heat balance, and emmission of pollutants.

  9. Overshooting by differential heating

    CERN Document Server

    Andrássy, R

    2015-01-01

    On the long nuclear time scale of stellar main-sequence evolution, even weak mixing processes can become relevant for redistributing chemical species in a star. We investigate a process of "differential heating," which occurs when a temperature fluctuation propagates by radiative diffusion from the boundary of a convection zone into the adjacent radiative zone. The resulting perturbation of the hydrostatic equilibrium causes a flow that extends some distance from the convection zone. We study a simplified differential-heating problem with a static temperature fluctuation imposed on a solid boundary. The astrophysically relevant limit of a high Reynolds number and a low P\\'eclet number (high thermal diffusivity) turns out to be interestingly non-intuitive. We derive a set of scaling relations for the stationary differential heating flow. A numerical method adapted to a high dynamic range in flow amplitude needed to detect weak flows is presented. Our two-dimensional simulations show that the flow reaches a sta...

  10. RF Pulsed Heating

    Energy Technology Data Exchange (ETDEWEB)

    Pritzkau, David P.

    2002-01-03

    RF pulsed heating is a process by which a metal is heated from magnetic fields on its surface due to high-power pulsed RF. When the thermal stresses induced are larger than the elastic limit, microcracks and surface roughening will occur due to cyclic fatigue. Pulsed heating limits the maximum magnetic field on the surface and through it the maximum achievable accelerating gradient in a normal conducting accelerator structure. An experiment using circularly cylindrical cavities operating in the TE{sub 011} mode at a resonant frequency of 11.424 GHz is designed to study pulsed heating on OFE copper, a material commonly used in normal conducting accelerator structures. The high-power pulsed RF is supplied by an X-band klystron capable of outputting 50 MW, 1.5 {micro}s pulses. The test pieces of the cavity are designed to be removable to allow testing of different materials with different surface preparations. A diagnostic tool is developed to measure the temperature rise in the cavity utilizing the dynamic Q change of the resonant mode due to heating. The diagnostic consists of simultaneously exciting a TE{sub 012} mode to steady-state in the cavity at 18 GHz and measuring the change in reflected power as the cavity is heated from high-power pulsed RF. Two experimental runs were completed. One run was executed at a calculated temperature rise of 120 K for 56 x 10{sup 6} pulses. The second run was executed at a calculated temperature rise of 82 K for 86 x 10{sup 6} pulses. Scanning electron microscope pictures show extensive damage occurring in the region of maximum temperature rise on the surface of the test pieces.

  11. Solar industrial process heat

    Energy Technology Data Exchange (ETDEWEB)

    Lumsdaine, E.

    1981-04-01

    The aim of the assessment reported is to candidly examine the contribution that solar industrial process heat (SIPH) is realistically able to make in the near and long-term energy futures of the United States. The performance history of government and privately funded SIPH demonstration programs, 15 of which are briefly summarized, and the present status of SIPH technology are discussed. The technical and performance characteristics of solar industrial process heat plants and equipment are reviewed, as well as evaluating how the operating experience of over a dozen SIPH demonstration projects is influencing institutional acceptance and economoc projections. Implications for domestic energy policy and international implications are briefly discussed. (LEW)

  12. Harnessing solar heat

    CERN Document Server

    Norton, Brian

    2013-01-01

    Systems engineered by man to harness solar heat in a controlled manner now include a diverse range of technologies each serving distinctive needs in particular climate contexts. This text covers the breadth of solar energy technologies for the conversion of solar energy to provide heat, either as the directly-used output or as an intermediary to other uses such as power generation or cooling. It is a wholly updated, extended and revised version of “Solar Energy Thermal Technology” first published in 1992. The text draws on the own author’s research and that of numerous colleagues and

  13. Heat treatment deformations

    Energy Technology Data Exchange (ETDEWEB)

    Bavaro, A. (Soliveri SpA, Caravaggio (Italy))

    1990-02-01

    Types and causes of heat treatement derived isotropic and anisotropic dilatancies in ferrous materials are reviewed. The concepts are developed in such a way as to allow extension to all materials exhibiting martensitic tempering behaviour. This paper intends to illustrate the basic processes of dimensional variations undergone by the materials under heat treatments. The parametric analysis includes an analysis of the interactions amongst the parameters themselves. The relative importance of each parameter is assessed in order to determine methods to attenuate deformation action. Simplified examples are offered to provide technicians explanations as to why specific deformations occur and indications on improved materials working techniques.

  14. Nanocrystallinity induced by heating

    DEFF Research Database (Denmark)

    Mørup, Steen; Meaz, T.M.; Bender Koch, C.;

    1997-01-01

    Samples of akaganeite (beta-FeOOH) and goethite (alpha-FeOOH) have been studied after heating at various temperatures up to 800 C. X-ray diffraction and Mossbauer spectroscopy measurements showed that slightly below the temperatures at which the samples transform to hematite (alpha-Fe2O3) the oxy......Samples of akaganeite (beta-FeOOH) and goethite (alpha-FeOOH) have been studied after heating at various temperatures up to 800 C. X-ray diffraction and Mossbauer spectroscopy measurements showed that slightly below the temperatures at which the samples transform to hematite (alpha-Fe2O3...

  15. Geothermal Heat Pump Performance

    Energy Technology Data Exchange (ETDEWEB)

    Boyd, Tonya L.; Lienau, Paul J.

    1995-01-01

    Geothermal heat pump systems are a promising new energy technology that has shown rapid increase in usage over the past ten years in the United States. These systems offer substantial benefits to customers 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. Information was developed on the status of electric utility marketing programs, barriers to market penetration, incentive programs, and benefits.

  16. Geothermal heat pump performance

    Energy Technology Data Exchange (ETDEWEB)

    Boyd, Tonya L.; Lienau, Paul J.

    1995-01-01

    Geothermal heat pump systems are a promising new energy technology that has shown rapid increase in usage over the past ten years in the United States. These systems offer substantial benefits to customers 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. Information was developed on the status of electric utility marketing programs, barriers to market penetration, incentive programs, and benefits.

  17. A heat transfer textbook

    CERN Document Server

    Lienhard, John H

    2011-01-01

    This introduction to heat transfer offers advanced undergraduate and graduate engineering students a solid foundation in the subjects of conduction, convection, radiation, and phase-change, in addition to the related topic of mass transfer. A staple of engineering courses around the world for more than three decades, it has been revised and updated regularly by the authors, a pair of recognized experts in the field. The text addresses the implications, limitations, and meanings of many aspects of heat transfer, connecting the subject to its real-world applications and developing students' ins

  18. Duplex Stirling gas fired heating only heat pump

    Science.gov (United States)

    Beale, W.

    1982-03-01

    In phase I the Duplex Stirling Gas fired Heat Pump was analyzed with the aid of the Sunpower third order simulation and optimization code and found to show heating COP of 1.7 at the rating point of 8 C (17 F) with a heat delivery of 10 kW. Also it was found that a direct heat exchange between working fluid and source and sink air was consistent with high COP in the heat pump, thus eliminating the need for an intermediate heat transfer fluid and its associated pumps and controls. Further, it was demonstrated in the simulation that the heat engine power output could be matched to the heat pump load over the range of source temperatures without need of complex control systems. Cost estimates, along with COP figures from the analysis indicated a payback time of 2 to 4 years in completion with existing combustion heating systems in northern climates.

  19. Primary energy savings using heat storage for biomass heating systems

    Directory of Open Access Journals (Sweden)

    Mitrović Dejan M.

    2012-01-01

    Full Text Available District heating is an efficient way to provide heat to residential, tertiary and industrial users. The heat storage unit is an insulated water tank that absorbs surplus heat from the boiler. The stored heat in the heat storage unit makes it possible to heat even when the boiler is not working, thus increasing the heating efficiency. In order to save primary energy (fuel, the boiler operates on nominal load every time it is in operation (for the purpose of this research. The aim of this paper is to analyze the water temperature variation in the heat storage, depending on the heat load and the heat storage volume. Heat load is calculated for three reference days, with average daily temperatures from -5 to 5°C. The primary energy savings are also calculated for those days in the case of using heat storage in district heating.[Projekat Ministarstva nauke Republike Srbije, br. TR 33051: The concept of sustainable energy supply of settlements with energy efficient buildings

  20. Heat Transfer Characteristics of SiC-coated Heat Pipe for Passive Decay Heat Removal

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kyung Mo; Kim, In Guk; Jeong, Yeong Shin; Bang, In Cheol [Ulsan National Institute of Science and Technology, Ulsan (Korea, Republic of)

    2014-10-15

    The main concern with the Fukushima accident was the failure of active and passive core cooling systems. The main function of existing passive decay heat removal systems is feeding additional coolant to the reactor core. Thus, an established emergency core cooling system (ECCS) cannot operate properly because of impossible depressurization under the station blackout (SBO) condition. Therefore, a new concept for passive decay heat removal system is required. In this study, an innovative hybrid control rod concept is considered for passive in-core decay heat removal that differs from the existing direct vessel injection core cooling system and passive auxiliary feedwater system (PAFS). The heat transfer between the evaporator and condenser sections occurs by phase change of the working fluid and capillary action induced by wick structures installed on the inner wall of the heat pipe. In this study, a hybrid control rod is developed to take the roles of both neutron absorption and heat removal by combining the functions of a heat pipe and control rod. Previous studies on enhancing the heat removal capacity of heat pipes used nanofluids, self-rewetting fluids, various wick structures and condensers. Many studies have examined the thermal performances of heat pipes using various nanofluids. They concluded that the enhanced thermal performance of the heat pipe using nanofluids is due to nanoparticle deposition on the wick structures. Thus, the wick structure of heat pipes has been modified by nanoparticle deposition to enhance the heat removal capacity. However, previous studies used relatively small heat pipes and narrow ranges of heat loads. The environment of a nuclear reactor is very specific, and the decay heat produced by fission products after shutdown is relatively large. Thus, this study tested a large-scale heat pipe over a wide range of power. The concept of a hybrid heat pipe for an advanced in-core decay heat removal system was introduced for complete

  1. Conjugate heat and mass transfer in heat mass exchanger ducts

    CERN Document Server

    Zhang, Li-Zhi

    2013-01-01

    Conjugate Heat and Mass Transfer in Heat Mass Exchanger Ducts bridges the gap between fundamentals and recent discoveries, making it a valuable tool for anyone looking to expand their knowledge of heat exchangers. The first book on the market to cover conjugate heat and mass transfer in heat exchangers, author Li-Zhi Zhang goes beyond the basics to cover recent advancements in equipment for energy use and environmental control (such as heat and moisture recovery ventilators, hollow fiber membrane modules for humidification/dehumidification, membrane modules for air purification, desi

  2. Residential CO2 Heat Pump System for Combined Space Heating and Hot Water Heating

    OpenAIRE

    Stene, Jørn

    2004-01-01

    Carbon dioxide (CO2, R-744) has been identified as a promising alternative to conventional working fluids in a number of applications due to its favourable environmental and thermophysical properties. Previous work on residential CO2 heat pumps has been dealing with systems for either space heating or hot water heating, and it was therefore considered interesting to carry out a theoretical and experimental study of residential CO2 heat pump systems for combined space heating and hot water hea...

  3. Heat storage system adapted for incongruently melting heat storage materials and congruently melting heat storage materials

    Energy Technology Data Exchange (ETDEWEB)

    Schoenfelder, J.L.

    1980-12-30

    A heat storage article adapted for prevention of stratification of incongruently melting heat storage materials, such as eutectic salts, and adapted for use with congruently melting heat storage materials, such as paraffins. The article is comprised of a concrete stone composition, a certain portion of which is comprised of metallic heat transfer materials in order to increase heat transfer through the concrete structure. The concrete structure has an internal cavity which is filled with either the eutectic salt material or the paraffin material.

  4. Heating Systems Specialist.

    Science.gov (United States)

    Air Force Training Command, Sheppard AFB, TX.

    This instructional package is intended for use in training Air Force personnel enrolled in a program for apprentice heating systems specialists. Training includes instruction in fundamentals and pipefitting; basic electricity; controls, troubleshooting, and oil burners; solid and gas fuel burners and warm air distribution systems; hot water…

  5. Solar-heating system

    Science.gov (United States)

    1979-01-01

    Report describes solar modular domestic-hot-water and space-heating system intended for use in small single family dwelling where roof-mounted collectors are not feasible. Contents include design, performance, and hardware specifications for assembly, installation, operation, and maintenance of system.

  6. Heat loss from Buildings

    DEFF Research Database (Denmark)

    Karlsson, Kenneth; Næraa, Rikke

    1997-01-01

    Determination of heat loss coefficients for buildings in Denmark. The coefficient are determined for 15 building groups and 3 year intervals. They are based on the BBR-registre and assumptions of U-values(W/K*m2)and computed in a simple spreed sheet model.The results are used in the REVEILLE...... project for calculations in the SESAM model....

  7. Heat-Related Illnesses

    Science.gov (United States)

    ... stroke and exhaustion. Heat Cramps Symptoms include muscle spasms, usually in the legs and stomach area. To treat, have the person rest in a cool place and give small amounts of cool water, juice or a commercial sports liquid. (Do not give liquids if the person ...

  8. Heat-Related Illnesses

    Medline Plus

    Full Text Available ... Fact Sheet Health & Safety Tips Campaigns SUBSCRIBE Emergencies A-Z Share this! Home » Emergency 101 Heat-Related ... if the person becomes unconscious. READ IN EMERGENCIES A-Z Seizures Choking (Heimlich Maneuver) Vomiting and Diarrhea ...

  9. Heat-Related Illnesses

    Medline Plus

    Full Text Available ... Young children and the elderly are most at risk, but anyone can be affected. Here you will ... moist, pale skin, rapid pulse, elevated or lowered blood pressure, nausea, loss of consciousness, vomiting or a high body temperature. For late stage heat stroke symptoms, ...

  10. Heat-Related Illnesses

    Medline Plus

    Full Text Available ... Fact Sheet Health & Safety Tips Campaigns SUBSCRIBE Emergencies A-Z Share this! Home » Emergency 101 Heat-Related ... if the person becomes unconscious. READ IN EMERGENCIES A-Z Suicide Puncture Wounds Shock Resources Home Safety ...

  11. Solar Energy: Heat Transfer.

    Science.gov (United States)

    Knapp, Henry H., III

    This module on heat transfer is one of six in a series intended for use as supplements to currently available materials on solar energy and energy conservation. Together with the recommended texts and references (sources are identified), these modules provide an effective introduction to energy conservation and solar energy technologies. The…

  12. Solar Energy: Heat Storage.

    Science.gov (United States)

    Knapp, Henry H., III

    This module on heat storage is one of six in a series intended for use as supplements to currently available materials on solar energy and energy conservation. Together with the recommended texts and references (sources are identified), these modules provide an effective introduction to energy conservation and solar energy technologies. The module…

  13. Solar Energy: Home Heating.

    Science.gov (United States)

    Knapp, Henry H., III

    This module on home heating is one of six in a series intended for use as supplements to currently available materials on solar energy and energy conservation. Together with the recommended texts and references (sources are identified), these modules provide an effective introduction to energy conservation and solar energy technologies. The module…

  14. Heat conduction. 3. ed.

    Energy Technology Data Exchange (ETDEWEB)

    Jiji, Latif M. [City Coll. of City Univ. of New York, NY (United States). Dept. of Mechanical Engineering

    2009-07-01

    This textbook presents the classical topics of conduction heat transfer and extends the coverage to include chapters on perturbation methods, heat transfer in living tissue, and microscale conduction. This makes the book unique among the many published textbook on conduction heat transfer. Other noteworthy features of the book are: The material is organized to provide students with the tools to model, analyze and solve a wide range of engineering applications involving conduction heat transfer. Mathematical techniques are presented in a clear and simplified fashion to be used as instruments in obtaining solutions. The simplicity of one-dimensional conduction is used to drill students in the role of boundary conditions and to explore a variety of physical conditions that are of practical interest. Examples are carefully selected to illustrate the application of principles and the construction of solutions. Students are trained to follow a systematic problem solving methodology with emphasis on thought process, logic, reasoning and verification. Solutions to all examples and end-of-chapter problems follow an orderly problems solving approach. (orig.)

  15. Sudurnes Regional Heating Corp.

    Energy Technology Data Exchange (ETDEWEB)

    Lienau, P.J. [ed.

    1996-11-01

    The Svartsengi geothermal area is close to the town of Grindavik on the Rekjanes peninsula and is part of an active fissure swarm, lined with crater-rows and open fissures and faults. The high-temperature area has an area of 2 sq. km and shows only limited signs of geothermal activity at the surface. The reservoir, however, contains lots of energy and at least 8 wells supply the Svartsengi Power Plant with steam. The steam is not useable for domestic heating purposes so that heat exchangers are used to heat cold groundwater with the steam. Some steam is also used for producing 16.4 MW{sub e} of electrical power. The article shows the distribution system piping hot water to nine towns and the Keflavik International Airport. The effluent brine from the Svartsengi Plant is disposed of into a surface pond, called the Blue Lagoon, popular to tourists and people suffering from psoriasis and other forms of eczema seeking therapeutic effects from the silica rich brine. This combined power plant and regional district heating system (cogeneration) is an interesting and unique design for the application of geothermal energy.

  16. Confucius Heats Up

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    @@ The opening cer-emony of the 2008 Beijing Olympic Games left the world spectacular impression. One of the most unforget-table ones was the recitation of Confucius's quotes by the 3000 people who acted as his students group. A Confucius heat spreads China and the rest of the world soon.

  17. Heat-Related Illnesses

    Medline Plus

    Full Text Available ... Fact Sheet Health & Safety Tips Campaigns SUBSCRIBE Emergencies A-Z Share this! Home » Emergency 101 Heat-Related ... if the person becomes unconscious. READ IN EMERGENCIES A-Z Listen to your Symptoms - When To Seek ...

  18. Microtube strip heat exchanger

    Science.gov (United States)

    Doty, F. D.

    1991-04-01

    During the last quarter, Doty Scientific, Inc. (DSI) continued to make progress on the microtube strip (MTS) heat exchangers. The team has begun a heat exchanger stress analysis; however, they have been concentrating the bulk of their analytical energies on a computational fluid dynmaics (CFD) model to determine the location and magnitude of shell-side flow maldistribution which decreases heat exchanger effectiveness. DSI received 120 fineblanked tubestrips from Southern Fineblanking (SFB) for manufacturing process development. Both SFB and NIST provided inspection reports of the tubestrips. DSI completed the tooling required to encapsulate a tube array and press tubestrips on the array. Pressing the tubestrips on tube arrays showed design deficiencies both in the tubestrip design and the tooling design. DSI has a number of revisions in process to correct these deficiencies. The research effort has identified a more economical fusible alloy for encapsulating the tube array, and determined the parameters required to successfully encapsulate the tube array with the new alloy. A more compact MTS heat exchanger bank was designed.

  19. Heat-Related Illnesses

    Medline Plus

    Full Text Available ... Fact Sheet Health & Safety Tips Campaigns SUBSCRIBE Emergencies A-Z Share this! Home » Emergency 101 Heat-Related ... if the person becomes unconscious. READ IN EMERGENCIES A-Z Seizures Sore Throat Sunburn and Sun Safety ...

  20. Heat-Related Illnesses

    Medline Plus

    Full Text Available ... Fact Sheet Health & Safety Tips Campaigns SUBSCRIBE Emergencies A-Z Share this! Home » Emergency 101 Heat-Related ... if the person becomes unconscious. READ IN EMERGENCIES A-Z Sunburn and Sun Safety Sore Throat Choking ( ...

  1. Heat loss from Buildings

    DEFF Research Database (Denmark)

    Karlsson, Kenneth; Næraa, Rikke

    1997-01-01

    Determination of heat loss coefficients for buildings in Denmark. The coefficient are determined for 15 building groups and 3 year intervals. They are based on the BBR-registre and assumptions of U-values(W/K*m2)and computed in a simple spreed sheet model.The results are used in the REVEILLE...

  2. District heating by radiant heat recovery from cement kilns

    Energy Technology Data Exchange (ETDEWEB)

    Caputo, Antonio C.; Palumbo, Mario; Pelagagge, Pacifico M.; Salini, Paolo [University of L' Aquila, Monteluco (Italy). Dept. of Mechanical, Energy and Management Engineering]. E-mail: caputo@ing.univaq.it; palumbo@ing.univaq.it; pelmar@ing.univaq.it; salini@ing.univaq.it

    2008-07-01

    Heat loss from rotary kilns may represent a significant percentage of the total energy input especially in high energy-intensive industrial sectors such as cement production. In this paper the technical and economic feasibility of recovering radiant heat lost through the kiln surface, by means of a secondary external shell acting as a heat exchanger for a transfer fluid, is evaluated for district heating purposes. At first the system architecture is outlined and a technical and economical model addressing both the performances and cost estimation for the heat exchanger and the district heating network is developed. Subsequently, a parametric profitability analysis is carried out with reference to some relevant parameters characterizing the available recoverable waste heat and the size of the heat distribution network, namely the distance between kiln and user area and extension of the district heating network. This is made to obtain a mapping of the conditions were the proposed heat recovery system is economically feasible. In the paper it is demonstrated that the relevant heat consumption of cement production may make the district heating option for heat recovery a viable one even in case of low density of inhabitants in the surroundings of the plant. Furthermore significant fuel savings and emission reductions are achieved respect the adoption of traditional residential boilers. author)

  3. Prototype solar heating and combined heating cooling systems

    Science.gov (United States)

    1978-01-01

    The design and development of eight prototype solar heating and combined heating and cooling systems is discussed. The program management and systems engineering are reported, and operational test sites are identified.

  4. Macroscopic heat transport equations and heat waves in nonequilibrium states

    Science.gov (United States)

    Guo, Yangyu; Jou, David; Wang, Moran

    2017-03-01

    Heat transport may behave as wave propagation when the time scale of processes decreases to be comparable to or smaller than the relaxation time of heat carriers. In this work, a generalized heat transport equation including nonlinear, nonlocal and relaxation terms is proposed, which sums up the Cattaneo-Vernotte, dual-phase-lag and phonon hydrodynamic models as special cases. In the frame of this equation, the heat wave propagations are investigated systematically in nonequilibrium steady states, which were usually studied around equilibrium states. The phase (or front) speed of heat waves is obtained through a perturbation solution to the heat differential equation, and found to be intimately related to the nonlinear and nonlocal terms. Thus, potential heat wave experiments in nonequilibrium states are devised to measure the coefficients in the generalized equation, which may throw light on understanding the physical mechanisms and macroscopic modeling of nanoscale heat transport.

  5. Heat pipe radiator. [for spacecraft waste heat rejection

    Science.gov (United States)

    Swerdling, B.; Alario, J.

    1973-01-01

    A 15,000 watt spacecraft waste heat rejection system utilizing heat pipe radiator panels was investigated. Of the several concepts initially identified, a series system was selected for more in-depth analysis. As a demonstration of system feasibility, a nominal 500 watt radiator panel was designed, built and tested. The panel, which is a module of the 15,000 watt system, consists of a variable conductance heat pipe (VCHP) header, and six isothermalizer heat pipes attached to a radiating fin. The thermal load to the VCHP is supplied by a Freon-21 liquid loop via an integral heat exchanger. Descriptions of the results of the system studies and details of the radiator design are included along with the test results for both the heat pipe components and the assembled radiator panel. These results support the feasibility of using heat pipes in a spacecraft waste heat rejection system.

  6. Control of heat source in a heat conduction problem

    Science.gov (United States)

    Lyashenko, V.; Kobilskaya, E.

    2014-11-01

    The mathematical model of thermal processes during the heat treatment of a moving axisymmetric environment, for example wire. is considered. The wire is heated by internal constantly or periodically operating heat source. It is presented in the form of initial-boundary value problem for the unsteady heat equation with internal constantly or periodically operating heat source. The purpose of the work is the definition of control parameter of temperature field of a moving area, which is heated by internal heat source. The control parameters are determined by solving a nonlocal problem for the heat equation. The problem of getting an adequate temperature distribution throughout the heating area is considered. Therefore, a problem of heat source control is solved, in particular, control by electric current. Control of the heat source allows to maintain the necessary, from a technological point of view, temperature in the heating area. In this paper, to find additional information about the source of heat. The integral condition is used in the control problem. Integral condition, which is considered in the work, determines the energy balance of the heating zone and connects the desired temperature distribution in the internal points of area with temperatures at the boundaries. Control quality in an extremum formulation of the problem is assessed using the quadratic functional. In function space, from a physical point of view, proposed functional is the absolute difference between the actual emission of energy and absorbed energy in the heating zone. The absorbed energy is calculated by solving of the boundary value problem. Methods of determining the control parameters of temperature field are proposed. The resulting problem is solved by iterative methods. At different physical conditions, numerical calculations are carried out, control parameters of the heat treatment process are obtained.

  7. Effect of orientation on heat transfer in pulsating heat pipe

    Directory of Open Access Journals (Sweden)

    Naumova A. M.

    2010-10-01

    Full Text Available The paper presents the results of experimental research of orientation effect on heat transfer characteristics of a pulsating heat pipe (PHP. It is shown that transport of either mass or heat depends on PHP orientation against it`s axis. As a consequence of comparing experimental data with other authors’ results it was concluded that PHP thermal resistance depends not only on orientation but on some other determinal factors such as device construction and thermophysical properties of heat carrier.

  8. Research of heat exchange rate of the pulsating heat pipe

    Directory of Open Access Journals (Sweden)

    Kravets V. Yu.

    2010-02-01

    Full Text Available Given article presents experimental research of heat transfer characteristics of the pulsating heat pipe (PHP which consists of seven coils with 1 mm inner diameter. Water was used as the heat carrier. PHP construction, measuring circuit and research technique are presented. It is shown that under PHP functioning there are two characteristic modes of operation, which can be distinguished by values of thermal resistance. PHP heat exchange features are disclosed.

  9. Industrial Heat Pump for a High Temperature District Heating Application

    DEFF Research Database (Denmark)

    Poulsen, Claus Nørgaard

    2013-01-01

    by excess thermal energy from thermal solar panels. An industrial heat pump system using the natural refrigerant ammonia, is extracting the thermal energy from the storage when needed, and produce hot water at 85°C, for the district heating grid. The heat pump also acts as contributor to electricity grid...

  10. A study of the heating and heat storage problems in passive solar heated room with greenhouse

    Institute of Scientific and Technical Information of China (English)

    CHENWei; LIUWei

    2003-01-01

    In this paper, heating and heat storage in passive solar heating room with greenhouse has been studied. The unsteady numerical simulation is employed to analyze the performance of the flow and temperature field for the typical sunny day of Wuhan, China, in winter in the heating system. The floor of passive solar heating room with a convective hole or not has great effects on temperature distribution and gas flow in heat storage layer of this system. Properties of the bed worked as solar absorber and storage layer have also been studied.

  11. Optimal usage of low temperature heat sources to supply district heating by heat pumps

    DEFF Research Database (Denmark)

    Pieper, Henrik; Ommen, Torben Schmidt; Markussen, Wiebke Brix

    2017-01-01

    This paper presents a theoretical study on the optimal usage of different low temperature heat sources to supply district heating by heat pumps. The study is based on data for the Copenhagen region. The heat sources were prioritized based on the coefficient of performance calculated for each hour....... Groundwater, seawater and air heat sources were compared with each other as well as to a scenario consisting of a combination of these heat sources. In addition, base load and peak load units were included. Characteristic parameters were the coefficient of performance, the number of full load hours...

  12. RSES heat pump technician certification

    Energy Technology Data Exchange (ETDEWEB)

    Zeiner, J.

    1996-06-01

    In 1987 the National Heat Pump certification test was developed by the Refrigeration Service Engineers Society (RSES), and in 1994, the program was more specifically named Heat Pump Service Technician Certification. This report describes the benefits of certification.

  13. Arc Heated Scramjet Test Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The Arc Heated Scramjet Test Facility is an arc heated facility which simulates the true enthalpy of flight over the Mach number range of about 4.7 to 8 for free-jet...

  14. Transient heating of moving objects

    Directory of Open Access Journals (Sweden)

    E.I. Baida

    2014-06-01

    Full Text Available A mathematical model of transient and quasistatic heating of moving objects by various heat sources is considered. The mathematical formulation of the problem is described, examples of thermal calculation given.

  15. Adjustable Induction-Heating Coil

    Science.gov (United States)

    Ellis, Rod; Bartolotta, Paul

    1990-01-01

    Improved design for induction-heating work coil facilitates optimization of heating in different metal specimens. Three segments adjusted independently to obtain desired distribution of temperature. Reduces time needed to achieve required temperature profiles.

  16. VTX HyHeat Project

    Data.gov (United States)

    National Aeronautics and Space Administration — In this project Orbital Technologies Corporation (ORBITEC) will utilize its unique vortex propulsion technology to develop a high-capacity heating system to heat...

  17. Impedance and component heating

    CERN Document Server

    Métral, E; Mounet, N; Pieloni, T; Salvant, B

    2015-01-01

    The impedance is a complex function of frequency, which represents, for the plane under consideration (longitudinal, horizontal or vertical), the force integrated over the length of an element, from a “source” to a “test” wave, normalized by their charges. In general, the impedance in a given plane is a nonlinear function of the test and source transverse coordinates, but it is most of the time sufficient to consider only the first few linear terms. Impedances can influence the motion of trailing particles, in the longitudinal and in one or both transverse directions, leading to energy loss, beam instabilities, or producing undesirable secondary effects such as excessive heating of sensitive components at or near the chamber wall, called beam-induced RF heating. The LHC performance limitations linked to impedances encountered during the 2010-2012 run are reviewed and the currently expected situation during the HL-LHC era is discussed.

  18. The projective heat map

    CERN Document Server

    Schwartz, Richard Evan

    2017-01-01

    This book introduces a simple dynamical model for a planar heat map that is invariant under projective transformations. The map is defined by iterating a polygon map, where one starts with a finite planar N-gon and produces a new N-gon by a prescribed geometric construction. One of the appeals of the topic of this book is the simplicity of the construction that yet leads to deep and far reaching mathematics. To construct the projective heat map, the author modifies the classical affine invariant midpoint map, which takes a polygon to a new polygon whose vertices are the midpoints of the original. The author provides useful background which makes this book accessible to a beginning graduate student or advanced undergraduate as well as researchers approaching this subject from other fields of specialty. The book includes many illustrations, and there is also a companion computer program.

  19. Wavy tube heat pumping

    Energy Technology Data Exchange (ETDEWEB)

    Haldeman, C. W.

    1985-12-03

    A PVC conduit about 4'' in diameter and a little more than 40 feet long is adapted for being seated in a hole in the earth and surrounds a coaxial copper tube along its length that carries Freon between a heat pump and a distributor at the bottom. A number of wavy conducting tubes located between the central conducting tube and the wall of the conduit interconnect the distributor with a Freon distributor at the top arranged for connection to the heat pump. The wavy conducting tubing is made by passing straight soft copper tubing between a pair of like opposed meshing gears each having four convex points in space quadrature separated by four convex recesses with the radius of curvature of each point slightly less than that of each concave recess.

  20. A sublimation heat engine.

    Science.gov (United States)

    Wells, Gary G; Ledesma-Aguilar, Rodrigo; McHale, Glen; Sefiane, Khellil

    2015-03-03

    Heat engines are based on the physical realization of a thermodynamic cycle, most famously the liquid-vapour Rankine cycle used for steam engines. Here we present a sublimation heat engine, which can convert temperature differences into mechanical work via the Leidenfrost effect. Through controlled experiments, quantified by a hydrodynamic model, we show that levitating dry-ice blocks rotate on hot turbine-like surfaces at a rate controlled by the turbine geometry, temperature difference and solid material properties. The rotational motion of the dry-ice loads is converted into electric power by coupling to a magnetic coil system. We extend our concept to liquid loads, generalizing the realization of the new engine to both sublimation and the instantaneous vapourization of liquids. Our results support the feasibility of low-friction in situ energy harvesting from both liquids and ices. Our concept is potentially relevant in challenging situations such as deep drilling, outer space exploration or micro-mechanical manipulation.

  1. Hybrid Heat Exchangers

    Science.gov (United States)

    Tu, Jianping Gene; Shih, Wei

    2010-01-01

    A hybrid light-weight heat exchanger concept has been developed that uses high-conductivity carbon-carbon (C-C) composites as the heat-transfer fins and uses conventional high-temperature metals, such as Inconel, nickel, and titanium as the parting sheets to meet leakage and structural requirements. In order to maximize thermal conductivity, the majority of carbon fiber is aligned in the fin direction resulting in 300 W/m.K or higher conductivity in the fin directions. As a result of this fiber orientation, the coefficient of thermal expansion (CTE) of the C-C composite in both non-fiber directions matches well with the CTE of various high-temperature metal alloys. This allows the joining of fins and parting sheets by using high-temperature braze alloys.

  2. Heat-resistant materials

    CERN Document Server

    1997-01-01

    This handbook covers the complete spectrum of technology dealing with heat-resistant materials, including high-temperature characteristics, effects of processing and microstructure on high-temperature properties, materials selection guidelines for industrial applications, and life-assessment methods. Also included is information on comparative properties that allows the ranking of alloy performance, effects of processing and microstructure on high-temperature properties, high-temperature oxidation and corrosion-resistant coatings for superalloys, and design guidelines for applications involving creep and/or oxidation. Contents: General introduction (high-temperature materials characteristics, and mechanical and corrosion properties, and industrial applications); Properties of Ferrous Heat-Resistant Alloys (carbon, alloy, and stainless steels; alloy cast irons; and high alloy cast steels); Properties of superalloys (metallurgy and processing, mechanical and corrosion properties, degradation, and protective coa...

  3. Urban heat island 1

    DEFF Research Database (Denmark)

    Bühler, Oliver; Jensen, Marina Bergen; Petersen, Karen Sejr

    2010-01-01

    Urban Heat Island beskriver det forhold, at temperaturen i byområder er højere end temperaturen i tilgrænsede landområder. Årsagen hertil ligger i den urbane arealanvendelse, hvor en mindre andel af arealerne er dækket af vegetation, og en større andel består af forseglede arealer....

  4. Solar heating and cooling.

    Science.gov (United States)

    Duffie, J A; Beckman, W A

    1976-01-16

    We have adequate theory and engineering capability to design, install, and use equipment for solar space and water heating. Energy can be delivered at costs that are competitive now with such high-cost energy sources as much fuel-generated, electrical resistance heating. The technology of heating is being improved through collector developments, improved materials, and studies of new ways to carry out the heating processes. Solar cooling is still in the experimental stage. Relatively few experiments have yielded information on solar operation of absorption coolers, on use of night sky radiation in locations with clear skies, on the combination of a solar-operated Rankine engine and a compression cooler, and on open cycle, humidification-dehumidification systems. Many more possibilities for exploration exist. Solar cooling may benefit from collector developments that permit energy delivery at higher temperatures and thus solar operation of additional kinds of cycles. Improved solar cooling capability can open up new applications of solar energy, particularly for larger buildings, and can result in markets for retrofitting existing buildings. Solar energy for buildings can, in the next decade, make a significant contribution to the national energy economy and to the pocketbooks of many individual users. very large-aggregate enterprises in manufacture, sale, and installation of solar energy equipment can result, which can involve a spectrum of large and small businesses. In our view, the technology is here or will soon be at hand; thus the basic decisions as to whether the United States uses this resource will be political in nature.

  5. A heating tube

    Energy Technology Data Exchange (ETDEWEB)

    Burmistrov, V.M.; Rachev, L.A.

    1980-09-23

    Hollow needles made of an electrically conducting material are attached by hinges in the openings of the perforated end of an insert in order to intensify heat and mass transfer. The free sections of the needles are placed outside the insert, and a wick is placed on the wall of the frame in the condensation area. The wick overlaps the inlet openings of the insert.

  6. Heat release mechanism of energetics

    Energy Technology Data Exchange (ETDEWEB)

    Kubota, N. [Third Research Center, Technical Research and development Institute (Japan)

    1996-12-31

    Determination of the heat release mechanism of energetic materials is a major subject of combustion study. In order to elucidate the combustion process of various types of energetic materials a generalized combustion wave structure was proposed and the heat release process was discussed. The heat release process was significantly different between the physical structures of the materials: homogeneous and heterogeneous materials. The thermal structure of an azide polymer was evaluated to demonstrate the heat release mechanism. (author) 6 refs.

  7. Tubing for augmented heat transfer

    Energy Technology Data Exchange (ETDEWEB)

    Yampolsky, J.S.; Pavlics, P.

    1983-08-01

    The objectives of the program reported were: to determine the heat transfer and friction characteristics on the outside of spiral fluted tubing in single phase flow of water, and to assess the relative cost of a heat exchanger constructed with spiral fluted tubing with one using conventional smooth tubing. An application is examined where an isolation water/water heat exchanger was used to transfer the heat from a gaseous diffusion plant to an external system for energy recovery. (LEW)

  8. Earth's surface heat flux

    Directory of Open Access Journals (Sweden)

    J. H. Davies

    2009-11-01

    Full Text Available We present a revised estimate of Earth's surface heat flux that is based upon a heat flow data-set with 38 347 measurements, which is 55% more than used in previous estimates. Our methodology, like others, accounts for hydrothermal circulation in young oceanic crust by utilising a half-space cooling approximation. For the rest of Earth's surface, we estimate the average heat flow for different geologic domains as defined by global digital geology maps; and then produce the global estimate by multiplying it by the total global area of that geologic domain. The averaging is done on a polygon set which results from an intersection of a 1 degree equal area grid with the original geology polygons; this minimises the adverse influence of clustering. These operations and estimates are derived accurately using methodologies from Geographical Information Science. We consider the virtually un-sampled Antarctica separately and also make a small correction for hot-spots in young oceanic lithosphere. A range of analyses is presented. These, combined with statistical estimates of the error, provide a measure of robustness. Our final preferred estimate is 47±2 TW, which is greater than previous estimates.

  9. Nucleate boiling heat transfer

    Energy Technology Data Exchange (ETDEWEB)

    Saiz Jabardo, J.M. [Universidade da Coruna (Spain). Escola Politecnica Superior], e-mail: mjabardo@cdf.udc.es

    2009-07-01

    Nucleate boiling heat transfer has been intensely studied during the last 70 years. However boiling remains a science to be understood and equated. In other words, using the definition given by Boulding, it is an 'insecure science'. It would be pretentious of the part of the author to explore all the nuances that the title of the paper suggests in a single conference paper. Instead the paper will focus on one interesting aspect such as the effect of the surface microstructure on nucleate boiling heat transfer. A summary of a chronological literature survey is done followed by an analysis of the results of an experimental investigation of boiling on tubes of different materials and surface roughness. The effect of the surface roughness is performed through data from the boiling of refrigerants R-134a and R-123, medium and low pressure refrigerants, respectively. In order to investigate the extent to which the surface roughness affects boiling heat transfer, very rough surfaces (4.6 {mu}m and 10.5 {mu}m ) have been tested. Though most of the data confirm previous literature trends, the very rough surfaces present a peculiar behaviour with respect to that of the smoother surfaces (Ra<3.0 {mu}m). (author)

  10. Stirling Engine Heat Pump

    Science.gov (United States)

    Kagawa, Noboru

    Recent advances in the feasibility studies related to the Stirling engines and Stirling engine heat pumps which have been considered attractive due to their promising role in helping to solve the global environmental and energy problems,are reviewed. This article begins to describe the brief history of the Stirling engines and theoretical thermodynamic analysis of the Stirling cycle in order to understand several advantages on the Stirling engine. Furthermore,they could throw light on our question why the dream engines had not been promoted to practical applications during two hundred years. The present review shows that the Stirling engines with several unique advantages including 30 to 40% thermal efficiency and preferable exhaust characteristics,had been designed and constructed by recent tackling for the development of the advanced automobile and other applications using them. Based on the current state of art,it is being provided to push the Stirling engines combined with heat pumps based on the reversed Rankine cycle to the market. At present,however, many problems, especially for the durability, cost, and delicate engine parts must be enforced to solve. In addition,there are some possibilities which can increase the attractiveness of the Stirling engines and heat pumps. The review closes with suggestions for further research.

  11. Heat driven pulse pump

    Science.gov (United States)

    Benner, Steve M (Inventor); Martins, Mario S. (Inventor)

    2000-01-01

    A heat driven pulse pump includes a chamber having an inlet port, an outlet port, two check valves, a wick, and a heater. The chamber may include a plurality of grooves inside wall of the chamber. When heated within the chamber, a liquid to be pumped vaporizes and creates pressure head that expels the liquid through the outlet port. As liquid separating means, the wick, disposed within the chamber, is to allow, when saturated with the liquid, the passage of only liquid being forced by the pressure head in the chamber, preventing the vapor from exiting from the chamber through the outlet port. A plurality of grooves along the inside surface wall of the chamber can sustain the liquid, which is amount enough to produce vapor for the pressure head in the chamber. With only two simple moving parts, two check valves, the heat driven pulse pump can effectively function over the long lifetimes without maintenance or replacement. For continuous flow of the liquid to be pumped a plurality of pumps may be connected in parallel.

  12. Conduction heat transfer solutions

    Energy Technology Data Exchange (ETDEWEB)

    VanSant, J.H.

    1983-08-01

    This text is a collection of solutions to a variety of heat conduction problems found in numerous publications, such as textbooks, handbooks, journals, reports, etc. Its purpose is to assemble these solutions into one source that can facilitate the search for a particular problem solution. Generally, it is intended to be a handbook on the subject of heat conduction. There are twelve sections of solutions which correspond with the class of problems found in each. Geometry, state, boundary conditions, and other categories are used to classify the problems. Each problem is concisely described by geometry and condition statements, and many times a descriptive sketch is also included. The introduction presents a synopsis on the theory, differential equations, and boundary conditions for conduction heat transfer. Some discussion is given on the use and interpretation of solutions. Supplementary data such as mathematical functions, convection correlations, and thermal properties are included for aiding the user in computing numerical values from the solutions. 155 figs., 92 refs., 9 tabs.

  13. 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.

  14. Selection of Rational Heat Transfer Intensifiers in the Heat Exchanger

    Directory of Open Access Journals (Sweden)

    S. A. Burtsev

    2016-01-01

    Full Text Available The paper considers the applicability of different types of heat transfer intensifiers in the heat exchange equipment. A review of the experimental and numerical works devoted to the intensification of the dimpled surface, surfaces with pins and internally ribbed surface were presented and data on the thermal-hydraulic characteristics of these surfaces were given. We obtained variation of thermal-hydraulic efficiency criteria for 4 different objective functions and 15 options for the intensification of heat transfer. This makes it possible to evaluate the advantages of the various heat transfer intensifiers. These equations show influence of thermal and hydraulic characteristics of the heat transfer intensifiers (the values of the relative heat transfer and drag coefficients on the basic parameters of the shell-and-tube heat exchanger: the number and length of the tubes, the volume of the heat exchanger matrix, the coolant velocity in the heat exchanger matrix, coolant flow rate, power to pump coolant (or pressure drop, the amount of heat transferred, as well as the average logarithmic temperature difference. The paper gives an example to compare two promising heat transfer intensifiers in the tubes and shows that choosing the required efficiency criterion to search for optimal heat exchanger geometry is of importance. Analysis is performed to show that a dimpled surface will improve the effectiveness of the heat exchanger despite the relatively small value of the heat transfer intensification, while a significant increase in drag of other heat transfer enhancers negatively affects their thermalhydraulic efficiency. For example, when comparing the target functions of reducing the heat exchanger volume, the data suggest that application of dimpled surfaces in various fields of technology is possible. But there are also certain surfaces that can reduce the parameters of a heat exchanger. It is shown that further work development should be aimed at

  15. Characterization of industrial process waste heat and input heat streams

    Energy Technology Data Exchange (ETDEWEB)

    Wilfert, G.L.; Huber, H.B.; Dodge, R.E.; Garrett-Price, B.A.; Fassbender, L.L.; Griffin, E.A.; Brown, D.R.; Moore, N.L.

    1984-05-01

    The nature and extent of industrial waste heat associated with the manufacturing sector of the US economy are identified. Industry energy information is reviewed and the energy content in waste heat streams emanating from 108 energy-intensive industrial processes is estimated. Generic types of process equipment are identified and the energy content in gaseous, liquid, and steam waste streams emanating from this equipment is evaluated. Matchups between the energy content of waste heat streams and candidate uses are identified. The resultant matrix identifies 256 source/sink (waste heat/candidate input heat) temperature combinations. (MHR)

  16. Heating being put into service

    CERN Multimedia

    2016-01-01

    The SMB-SE group would like to inform you that, the central heating will start this year, on Monday 3 October 2016, and will be progressively and depending on the weather forecast put into service throughout. All buildings will have heating within the following few days. Thank you for your understanding. The CERN heating team SMB-SE

  17. Residential solar-heating system

    Science.gov (United States)

    1978-01-01

    Complete residential solar-heating and hot-water system, when installed in highly-insulated energy-saver home, can supply large percentage of total energy demand for space heating and domestic hot water. System which uses water-heating energy storage can be scaled to meet requirements of building in which it is installed.

  18. Heat transfer and fire spread

    Science.gov (United States)

    Hal E. Anderson

    1969-01-01

    Experimental testing of a mathematical model showed that radiant heat transfer accounted for no more than 40% of total heat flux required to maintain rate of spread. A reasonable prediction of spread was possible by assuming a horizontal convective heat transfer coefficient when certain fuel and flame characteristics were known. Fuel particle size had a linear relation...

  19. Ventilation and Heat Recovering System

    Directory of Open Access Journals (Sweden)

    Olga Bancea

    2007-01-01

    Full Text Available Some aspects concerning the heat reducing for ventilation, achieved by using heat recovering components and a combined heating--ventilating system, assuring both comfort and human health are presented. The floor imbedded systems together with air outlets elements could fulfill all the aesthetically desires, as well as comfort and they are ideal for family houses.

  20. Milk fouling in heat exchangers.

    NARCIS (Netherlands)

    Jeurnink, Th.J.M.

    1996-01-01

    The mechanisms of fouling of heat exchangers by milk were studied. Two major fouling mechanisms were indentified during the heat treatment of milk: (i) the formation and the subsequent deposition of activated serum protein molecules as a result of the heat denaturation; (ii) the precipitation of cal

  1. Staged regenerative sorption heat pump

    Science.gov (United States)

    Jones, Jack A. (Inventor)

    1995-01-01

    A regenerative adsorbent heat pump process and system for cooling and heating a space. A sorbent is confined in a plurality of compressors of which at least four are first stage and at least four are second stage. The first stage operates over a first pressure region and the second stage over a second pressure region which is higher than the first. Sorbate from the first stage enters the second stage. The sorbate loop includes a condenser, expansion valve, evaporator and the compressors. A single sorbate loop can be employed for single-temperature-control such as air conditioning and heating. Two sorbate loops can be used for two-temperature-control as in a refrigerator and freezer. The evaporator temperatures control the freezer and refrigerator temperatures. Alternatively the refrigerator temperature can be cooled by the freezer with one sorbate loop. A heat transfer fluid is circulated in a closed loop which includes a radiator and the compressors. Low temperature heat is exhausted by the radiator. High temperature heat is added to the heat transfer fluid entering the compressors which are desorbing vapor. Heat is transferred from compressors which are sorbing vapor to the heat transfer fluid, and from the heat transfer fluid to the compressors which are desorbing vapor. Each compressor is subjected to the following phases, heating to its highest temperature, cooling down from its highest temperature, cooling to its lowest temperature, and warming up from its lowest temperature. The phases are repeated to complete a cycle and regenerate heat.

  2. Temperature drops in heat pipes

    Energy Technology Data Exchange (ETDEWEB)

    Saatci, A.M.; Khalifa, A.M.A.; Akyurt, M.

    1986-01-01

    The role of entrainment in limiting heat pipe power handling capacity is discussed. The effect of entrainment on the measured temperature field in the integral heat pipe of a split system solar cooker is analyzed. An experimental set-up depicting a heat loop is presented, along with test results.

  3. Climate Fundamentals for Solar Heating.

    Science.gov (United States)

    Conservation and Renewable Energy Inquiry and Referral Service (DOE), Silver Spring, MD.

    The design of any solar heating system is influenced heavily by climate; in this bulletin, information on climate as related to solar heating is as related to solar heating is provided. Topics discussed include: (1) solar radiation; (2) degree days; (3) climate and calculations which make use of solar radiation and degree days; and (4)…

  4. Predicting Indoor Heat Exposure Risk during Extreme Heat Events

    Science.gov (United States)

    Quinn, Ashlinn; Tamerius, James D.; Perzanowski, Matthew; Jacobson, Judith S.; Goldstein, Inge; Acosta, Luis; Shaman, Jeffrey

    2014-01-01

    Increased heat-related morbidity and mortality are expected direct consequences of global warming. In the developed world, most fatal heat exposures occur in the indoor home environment, yet little is known of the correspondence between outdoor and indoor heat. Here we show how summertime indoor heat and humidity measurements from 285 low- and middle-income New York City homes vary as a function of concurrent local outdoor conditions. Indoor temperatures and heat index levels were both found to have strong positive linear associations with their outdoor counterparts; however, among the sampled homes a broad range of indoor conditions manifested for the same outdoor conditions. Using these models, we simulated indoor conditions for two extreme events: the 10-day 2006 NYC heat wave and a 9-day event analogous to the more extreme 2003 Paris heat wave. These simulations indicate that many homes in New York City would experience dangerously high indoor heat index levels during extreme heat events. These findings also suggest that increasing numbers of NYC low- and middle-income households will be exposed to heat index conditions above important thresholds should the severity of heat waves increase with global climate change. The study highlights the urgent need for improved indoor temperature and humidity management. PMID:24893319

  5. Heat pumps in combined heat and power systems

    DEFF Research Database (Denmark)

    Ommen, Torben Schmidt; Markussen, Wiebke Brix; Elmegaard, Brian

    2014-01-01

    of the considered cases. When considering a case where the heat pump is located at a CHP (combined heat and power) plant, a configuration that increases the DH return temperature proposes the lowest operation cost, as low as 12 EUR MWh-1 for a 90 °C e 40 °C DH network. Considering the volumetric heating capacity......Heat pumps have previously been proposed as a way to integrate higher amounts of renewable energy in DH (district heating) networks by integrating, e.g., wind power. The paper identifies and compares five generic configurations of heat pumps in DH systems. The operational performance......, a third configuration is superior in all cases. Finally, the three most promising heat pump configurations are integrated in a modified PQ-diagram of the CHP plant. Each show individual advantages, and for two, also disadvantages in order to achieve flexible operation....

  6. High temperature absorption compression heat pump for industrial waste heat

    DEFF Research Database (Denmark)

    Reinholdt, Lars; Horntvedt, B.; Nordtvedt, S. R.

    2016-01-01

    Heat pumps are currently receiving extensive interest because they may be able to support the integration of large shares of fluctuating electricity production based on renewable sources, and they have the potential for the utilization of low temperature waste heat from industry. In most industries......, the needed temperature levels often range from 100°C and up, but until now, it has been quite difficult to find heat pump technologies that reach this level, and thereby opening up the large-scale heat recovery in the industry. Absorption compression heat pumps can reach temperatures above 100°C......, and they have proved themselves a very efficient and reliable technology for applications that have large temperature changes on the heat sink and/or heat source. The concept of Carnot and Lorenz efficiency and its use in the analysis of system integration is shown. A 1.25 MW system having a Carnot efficiency...

  7. Solar-powered Rankine heat pump for heating and cooling

    Science.gov (United States)

    Rousseau, J.

    1978-01-01

    The design, operation and performance of a familyy of solar heating and cooling systems are discussed. The systems feature a reversible heat pump operating with R-11 as the working fluid and using a motor-driven centrifugal compressor. In the cooling mode, solar energy provides the heat source for a Rankine power loop. The system is operational with heat source temperatures ranging from 155 to 220 F; the estimated coefficient of performance is 0.7. In the heating mode, the vapor-cycle heat pump processes solar energy collected at low temperatures (40 to 80 F). The speed of the compressor can be adjusted so that the heat pump capacity matches the load, allowing a seasonal coefficient of performance of about 8 to be attained.

  8. Solar district heating, an option for future power supply in urban areas; Solare Nahwaerme - eine Option fuer die zukuenftige Energieversorgung im Siedlungsbereich

    Energy Technology Data Exchange (ETDEWEB)

    Fisch, M.N. [Technische Univ. Braunschweig (Germany). Fachbereich fuer Architektur]|[Steinbeis-Transferzentrum Energie, Gebaeude- und Solartechnik, Stuttgart (Germany)

    1999-03-01

    Small-scale solar-assisted district heating was successfully demonstrated in Germany in the first half of this decade. Large-scale systems with long-term thermal storage went into operation in Hamburg and Friedrichshafen at the end of 1996, and the first system with ground probe thermal storage in Neckarsulm at the end of 1997; a fourth installation with pebble/water thermal storage will become operational in the second half of 1998 in Chemnitz. What appeared utopian for many years became thus reality - space heating in Winter with solar energy gathered in Summer. Large solar installations are at least twice as cost-effective as small systems inspite of cost reduction achieved. Large systems avoid about two to three times more CO{sub 2}-emissions than small systems, based on the same amount of monetary investment. The system in Friedrichshafen cost 1.100 DM per m{sup 2} of collector inclusive long-term heat storage (or 11.000 DM per apartment) and covers nearly 50% of annual space heating and warm water demand. The investment costs in Neckarsulm are already about 20% lower; the specific cost for heat ranges between 300 and 500 DM/MWh. (orig.) [German] Nach der erfolgreichen Erprobung von kleineren solarunterstuetzten Nahwaermeprojekten in der ersten Haelfte der neunziger Jahre in Deutschland gingen Ende 1996 in Hamburg und Friedrichshafen die ersten solaren Grossanlagen mit Langzeit-Waermespeicher und Ende 1997 in Neckarsulm die erste Anlage mit Erdsonden-Waermespeicher in Betrieb; eine vierte solarunterstuetzte Nahwaermeversorgung mit einem Kies/Wasser-Waermespeicher wurde in der zweiten Haelfte 1998 in Chemnitz fertig gestellt. Damit wurde erreicht, was ueber Jahre hinweg utopisch erschien - mit Sonnenenergie aus dem Sommer Gebaeude im Winter zu beheizen. Trotz Kostenreduktion bei kleinen Anlagen bleiben grosse Solaranlagen mindestens doppelt so wirtschaftlich. Bei gleicher Investitionssumme vermeiden Grossanlagen etwa zwei- bis dreimal mehr klimaschaedliche CO

  9. Heat transport within the Earth

    CERN Document Server

    Herndon, J Marvin

    2011-01-01

    Numerous attempts have been made to interpret Earth's dynamic processes based upon heat transport concepts derived from ordinary experience. But, ordinary experience can be misleading, especially when underlain by false assumptions. Geodynamic considerations traditionally have embraced three modes of heat transport: conduction, convection, and radiation. Recently, I introduced a fourth, "mantle decompression thermal tsunami" that, I submit, is responsible for emplacing heat at the base of the Earth's crust. Here, I review thermal transport within the Earth and speculate that there might be a fifth mode: "heat channeling", involving heat transport from the core to "hot-spots" such as those that power the Hawaiian Islands and Iceland.

  10. Numerical modeling of microwave heating

    Directory of Open Access Journals (Sweden)

    Shukla A.K.

    2010-01-01

    Full Text Available The present study compares the temperature distribution within cylindrical samples heated in microwave furnace with those achieved in radiatively-heated (conventional furnace. Using a two-dimensional finite difference approach the thermal profiles were simulated for cylinders of varying radii (0.65, 6.5, and 65 cm and physical properties. The influence of susceptor-assisted microwave heating was also modeled for the same. The simulation results reveal differences in the heating behavior of samples in microwaves. The efficacy of microwave heating depends on the sample size and its thermal conductivity.

  11. Measuring of heat transfer coefficient

    DEFF Research Database (Denmark)

    Henningsen, Poul; Lindegren, Maria

    Subtask 3.4 Measuring of heat transfer coefficient Subtask 3.4.1 Design and setting up of tests to measure heat transfer coefficient Objective: Complementary testing methods together with the relevant experimental equipment are to be designed by the two partners involved in order to measure...... the heat transfer coefficient for a wide range of interface conditions in hot and warm forging processes. Subtask 3.4.2 Measurement of heat transfer coefficient The objective of subtask 3.4.2 is to determine heat transfer values for different interface conditions reflecting those typically operating in hot...

  12. Absorption-heat-pump system

    Science.gov (United States)

    Grossman, G.; Perez-Blanco, H.

    1983-06-16

    An improvement in an absorption heat pump cycle is obtained by adding adiabatic absorption and desorption steps to the absorber and desorber of the system. The adiabatic processes make it possible to obtain the highest temperature in the absorber before any heat is removed from it and the lowest temperature in the desorber before heat is added to it, allowing for efficient utilization of the thermodynamic availability of the heat supply stream. The improved system can operate with a larger difference between high and low working fluid concentrations, less circulation losses, and more efficient heat exchange than a conventional system.

  13. Measuring of heat transfer coefficient

    DEFF Research Database (Denmark)

    Henningsen, Poul; Lindegren, Maria

    Subtask 3.4 Measuring of heat transfer coefficient Subtask 3.4.1 Design and setting up of tests to measure heat transfer coefficient Objective: Complementary testing methods together with the relevant experimental equipment are to be designed by the two partners involved in order to measure...... the heat transfer coefficient for a wide range of interface conditions in hot and warm forging processes. Subtask 3.4.2 Measurement of heat transfer coefficient The objective of subtask 3.4.2 is to determine heat transfer values for different interface conditions reflecting those typically operating in hot...

  14. Heat pumps for the home

    CERN Document Server

    Cantor, John

    2013-01-01

    In recent years, heat pumps have emerged as a promising new form of technology with a relatively low environmental impact. Moreover, they have presented householders with an opportunity to reduce their heating bills. Heat pumps can heat a building by 'pumping' heat from either the ground or the air outside: an intriguing process which utilizes principles that are somewhat analogous to those employed in the domestic refrigerator. Armed with the practical information contained in these pages, homeowners will have the necessary knowledge to take advantage of this potentially low-carbon t

  15. Residential CO{sub 2} heat pump system for combined space heating and hot water heating

    Energy Technology Data Exchange (ETDEWEB)

    Stene, Joern

    2004-02-01

    Carbon dioxide (CO{sub 2}, R-744) has been identified as a promising alternative to conventional working fluids in a number of applications due to its favourable environmental and thermophysical properties. Previous work on residential CO{sub 2} heat pumps has been dealing with systems for either space heating or hot water heating, and it was therefore considered interesting to carry out a theoretical and experimental study of residential CO{sub 2} heat pump systems for combined space heating and hot water heating - o-called integrated CO{sub 2} heat pump systems. The scope of this thesis is limited to brine-to-water and water-to-water heat pumps connected to low-temperature hydronic space heating systems. The main conclusions are: (1) Under certain conditions residential CO{sub 2} heat pump systems for combined space heating and hot water heating may achieve the same or higher seasonal performance factor (SPF) than the most energy efficient state-of-the-art brine-to-water heat pumps. (2) In contrary to conventional heat pump systems for combined space heating and DHW heating, the integrated CO{sub 2} heat pump system achieves the highest COP in the combined heating mode and the DHW heating mode, and the lowest COP in the space heating mode. Hence, the larger the annual DHW heating demand, the higher the SPF of the integrated CO{sub 2} heat pump system. (3) The lower the return temperature in the space heating system and the lower the DHW storage temperature, the higher the COP of the integrated CO{sub 2} heat pump. A low return temperature in the space heating system also results in a moderate DHW heating capacity ratio, which means that a relatively large part of the annual space heating demand can be covered by operation in the combined heating mode, where the COP is considerably higher than in the space heating mode. (4) During operation in the combined heating mode and the DHW heating mode, the COP of the integrated CO{sub 2} heat pump is heavily influenced by

  16. Heat transfer and thermal control

    Science.gov (United States)

    Crosbie, A. L.

    Radiation heat transfer is considered along with conduction heat transfer, heat pipes, and thermal control. Attention is given to the radiative properties of a painted layer containing nonspherical pigment, bidirectional reflectance measurements of specular and diffuse surfaces with a simple spectrometer, the radiative equilibrium in a general plane-parallel environment, and the application of finite-element techniques to the interaction of conduction and radiation in participating medium, a finite-element approach to combined conductive and radiative heat transfer in a planar medium. Heat transfer in irradiated shallow layers of water, an analytical and experimental investigation of temperature distribution in laser heated gases, numerical methods for the analysis of laser annealing of doped semiconductor wafers, and approximate solutions of transient heat conduction in a finite slab are also examined. Consideration is also given to performance testing of a hydrogen heat pipe, heat pipe performance with gravity assist and liquid overfill, vapor chambers for an atmospheric cloud physics laboratory, a prototype heat pipe radiator for the German Direct Broadcasting TV Satellite, free convection in enclosures exposed to compressive heating, and a thermal analysis of a multipurpose furnace for material processing in space.

  17. Next Generation Microchannel Heat Exchangers

    CERN Document Server

    Ohadi, Michael; Dessiatoun, Serguei; Cetegen, Edvin

    2013-01-01

    In Next Generation Microchannel Heat Exchangers, the authors’ focus on the new generation highly efficient heat exchangers and presentation of novel data and technical expertise not available in the open literature.  Next generation micro channels offer record high heat transfer coefficients with pressure drops much less than conventional micro channel heat exchangers. These inherent features promise fast penetration into many mew markets, including high heat flux cooling of electronics, waste heat recovery and energy efficiency enhancement applications, alternative energy systems, as well as applications in mass exchangers and chemical reactor systems. The combination of up to the minute research findings and technical know-how make this book very timely as the search for high performance heat and mass exchangers that can cut costs in materials consumption intensifies.

  18. Realiability Of Heat Supply Subsystem

    Directory of Open Access Journals (Sweden)

    Babiarz Bożena

    2015-11-01

    Full Text Available The article presents the reliability analysis of subsystem of heat supply in the example of 47 thousand inhabitants’ city. The analysis was made on the basis of operational data made available by the Municipal Heating Company, between the years 2001 ÷ 2012. To describe the quantitative reliability of heat supply subsystem reliability indicators are used. Main times between failure and unitary failure rates including the month of their occurrence, type and diameter of the heating network, thermal power region were working out. Knowing the characteristics of the time to repair for the heating network, the reliability of heat supply subsystem for different thermal power region, considering the district heating system configuration can be determined.

  19. Heat, heat waves, and out-of-hospital cardiac arrest.

    Science.gov (United States)

    Kang, Si-Hyuck; Oh, Il-Young; Heo, Jongbae; Lee, Hyewon; Kim, Jungeun; Lim, Woo-Hyun; Cho, Youngjin; Choi, Eue-Keun; Yi, Seung-Muk; Sang, Do Shin; Kim, Ho; Youn, Tae-Jin; Chae, In-Ho; Oh, Seil

    2016-10-15

    Cardiac arrest is one of the common presentations of cardiovascular disorders and a leading cause of death. There are limited data on the relationship between out-of-hospital cardiac arrest (OHCA) and ambient temperatures, specifically extreme heat. This study investigated how heat and heat waves affect the occurrence of OHCA. Seven major cities in Korea with more than 1 million residents were included in this study. A heat wave was defined as a daily mean temperature above the 98th percentile of the yearly distribution for at least two consecutive days. A total of 50,318 OHCAs of presumed cardiac origin were identified from the nationwide emergency medical service database between 2006 and 2013. Ambient temperature and OHCA had a J-shaped relationship with a trough at 28°C. Heat waves were shown to be associated with a 14-% increase in the risk of OHCA. Adverse effects were apparent from the beginning of each heat wave period and slightly increased during its continuation. Excess OHCA events during heat waves occurred between 3PM and 5PM. Subgroup analysis showed that those 65years or older were significantly more susceptible to heat waves. Ambient temperature and OHCA had a J-shaped relationship. The risk of OHCA was significantly increased with heat waves. Excess OHCA events primarily occurred during the afternoon when the temperature was high. We found that the elderly were more susceptible to the deleterious effects of heat waves. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  20. Theory of heat

    CERN Document Server

    Maxwell, James Clerk

    2001-01-01

    Though James Clerk Maxwell (1831-1879) is best remembered for his epochal achievements in electricity and magnetism, he was wide-ranging in his scientific investigations, and he came to brilliant conclusions in virtually all of them. As James R. Newman put it, Maxwell ""combined a profound physical intuition, an exquisite feeling for the relationship of objects, with a formidable mathematical capacity to establish orderly connections among diverse phenomena. This blending of the concrete and the abstract was the chief characteristic of almost all his researches.""Maxwell's work on heat and st

  1. Heat Stress Monitor

    Science.gov (United States)

    1994-01-01

    The heavy, cumbersome body protection suits worn by members of hazardous materials response teams cause marked elevation of body temperatures, which can reduce effectiveness and lead to heat stress and injury. The CorTemp System, marketed by Human Technologies, Inc., provides the basis for a body temperature monitoring alarm system. Encased in a three-quarter-inch ingestible capsule, the system includes a mini-thermometer, miniature telemetry system, a microbattery and temperature sensor. It makes its way through the digestive system, continuously monitoring temperature. Findings are sent to the recorder by telemetry, and then displayed and stored for transfer to a computer.

  2. Cryogenic regenerative heat exchangers

    CERN Document Server

    Ackermann, Robert A

    1997-01-01

    An in-depth survey of regenerative heat exchangers, this book chronicles the development and recent commercialization of regenerative devices for cryogenic applications. Chapters cover historical background, concepts, practical applications, design data, and numerical solutions, providing the latest information for engineers to develop advanced cryogenic machines. The discussions include insights into the operation of a regenerator; descriptions of the cyclic and fluid temperature distributions in a regenerator; data for various matrix geometries and materials, including coarse and fine bronze, stainless steel-woven wire mesh screens, and lead spheres; and unique operating features of cryocoolers that produce deviations from ideal regenerator theory.

  3. Engineering heat transfer

    CERN Document Server

    Annaratone, Donatello

    2010-01-01

    This book is a generalist textbook; it is designed for anybody interested in heat transmission, including scholars, designers and students. Two criteria constitute the foundation of Annaratone's books, including the present one. The first one consists of indispensable scientific rigor without theoretical exasperation. The inclusion in the book of some theoretical studies, even if admirable for their scientific rigor, would have strengthened the scientific foundation of this publication, yet without providing the reader with further applicable know-how. The second criterion is to deliver practi

  4. Heat pumps in industry. Pt. 2: Applications

    Energy Technology Data Exchange (ETDEWEB)

    Lazzarin, R.M. [Padova Univ., Vicenza (Italy). Ist. di Ingegneria Gestionale

    1995-04-01

    A selection of applications of heat pumps in industry is described, reporting plant lay-outs and performances. The selection includes compression heat pumps at different temperatures, vapour recompression systems, absorption heat pumps and heat transformers. (author)

  5. Compact seasonal PCM heat storage for solar heating systems

    DEFF Research Database (Denmark)

    Dannemand, Mark

    . The seasonal availability of solar energy does however not match with the heating demands in buildings which typically are large in winter periods when limited solar energy is available. Heat can be stored over a few days in water stores but continuous heat losses limits the storage periods. The possibility...... required to keep the graphite suspended and evenly distributed in the SAT composite was also elucidated. Overall, the research has shown that it is possible to utilize stable supercooling of SAT for seasonal heat storage in actual application sized units. Furthermore, investigations have elucidated......Space heating of buildings and preparation of domestic hot water accounts for a large part of the society’s energy consumption. Solar radiation is an abundant and renewable energy source which can be harvested by solar collectors and used to cover heating demands in the built environment...

  6. A Review on Heat Transfer Improvent of Plate Heat Exchanger

    Directory of Open Access Journals (Sweden)

    Abhishek Nandan

    2015-03-01

    Full Text Available Plate heat exchanger has found a wide range of application in various industries like food industries, chemical industries, power plants etc. It reduces the wastage of energy and improves the overall efficiency of the system. Hence, it must be designed to obtain the maximum heat transfer possible. This paper is presented in order to study the various theories and results given over the improvement of heat transfer performance in a plate heat exchanger. However, there is still a lack in data and generalized equations for the calculation of different parameters in the heat exchanger. It requires more attention to find out various possible correlations and generalized solutions for the performance improvement of plate heat exchanger.

  7. Crustal Heat Production and Mantle Heat Flow in Southeast China

    Institute of Scientific and Technical Information of China (English)

    胡圣标; 汪集旸

    1994-01-01

    The correlation between seismic velocity (vp) and radiogenic heat production (A) en-ables the distribution of crustal heat production to be evaluated,from which the mantle heat flow for 21seismic velocity-depth profiles located along the two continental geotraverses in Southeast China can bededuced.Several approaches have been proposed to special problems connected with the conversion ofseismic velocities into heat production in orogenic areas.The results show that the crustal heat flow inSoutheast China is quite inhomogeneous,varying between 17.8 and 46 mW·m-2,which can be attribut-ed to the complicated crustal structure related to overthrusting and overlapping in the upper crust.The re-markable regional variation in the mantle heat flow,ranging from 23.2 to 41.6 mW·m-2,correspondsto the large-scale tectonothermal evolution of the orogenic belts.

  8. Solar heat gain factors and heat loss coefficients for passive heating concepts

    Energy Technology Data Exchange (ETDEWEB)

    Bhandari, M.S.; Bansal, N.K. (Indian Institute of Technology, Hauz Khas (India))

    1994-08-01

    The concept of solar heat gain factor has been introduced for calculating the net energy gain of passive heating elements and other components of a building as a result of incident solar radiation. For passive heating concepts (namely, the direct gain, mass wall, water wall, Trombe wall, and solarium), exact analytical expressions have been obtained for the solar heat gain factors and the corresponding overall heat loss coefficients. These will allow a building designer to calculate immediately the overall heat gain/loss in a building. Numerical calculations have been done for typical values of solar radiation and ambient temperature of typical climatic conditions in India. The method has been compared with the other methods reported in the literature so far. A good comparison is found between the earlier methods and the method of using solar gain factors and the corresponding heat transfer values.

  9. A sublimation heat engine

    Science.gov (United States)

    Wells, Gary G.; Ledesma-Aguilar, Rodrigo; McHale, Glen; Sefiane, Khellil

    2015-01-01

    Heat engines are based on the physical realization of a thermodynamic cycle, most famously the liquid–vapour Rankine cycle used for steam engines. Here we present a sublimation heat engine, which can convert temperature differences into mechanical work via the Leidenfrost effect. Through controlled experiments, quantified by a hydrodynamic model, we show that levitating dry-ice blocks rotate on hot turbine-like surfaces at a rate controlled by the turbine geometry, temperature difference and solid material properties. The rotational motion of the dry-ice loads is converted into electric power by coupling to a magnetic coil system. We extend our concept to liquid loads, generalizing the realization of the new engine to both sublimation and the instantaneous vapourization of liquids. Our results support the feasibility of low-friction in situ energy harvesting from both liquids and ices. Our concept is potentially relevant in challenging situations such as deep drilling, outer space exploration or micro-mechanical manipulation. PMID:25731669

  10. Heat Capacity in Proteins

    Science.gov (United States)

    Prabhu, Ninad V.; Sharp, Kim A.

    2005-05-01

    Heat capacity (Cp) is one of several major thermodynamic quantities commonly measured in proteins. With more than half a dozen definitions, it is the hardest of these quantities to understand in physical terms, but the richest in insight. There are many ramifications of observed Cp changes: The sign distinguishes apolar from polar solvation. It imparts a temperature (T) dependence to entropy and enthalpy that may change their signs and which of them dominate. Protein unfolding usually has a positive ΔCp, producing a maximum in stability and sometimes cold denaturation. There are two heat capacity contributions, from hydration and protein-protein interactions; which dominates in folding and binding is an open question. Theoretical work to date has dealt mostly with the hydration term and can account, at least semiquantitatively, for the major Cp-related features: the positive and negative Cp of hydration for apolar and polar groups, respectively; the convergence of apolar group hydration entropy at T ≈ 112°C; the decrease in apolar hydration Cp with increasing T; and the T-maximum in protein stability and cold denaturation.

  11. High Temperature Thermoacoustic Heat Pump

    Energy Technology Data Exchange (ETDEWEB)

    Tijani, H.; Spoelstra, S. [ECN Biomass and Energy Efficiency, Petten (Netherlands)

    2012-07-15

    Thermoacoustic technology can provide new types of heat pumps that can be deployed in different applications. Thermoacoustic heat pumps can for example be applied in dwellings to generate cooling or heating. Typically, space and water heating makes up about 60% of domestic and office energy consumption. The application of heat pumps can contribute to achieve energy savings and environmental benefits by reducing CO2 and NOx emissions. This paper presents the study of a laboratory scale thermoacoustic-Stirling heat pump operating between 10C and 80C which can be applied in domestics and offices. The heat pump is driven by a thermoacoustic-Stirling engine. The experimental results show that the heat pump pumps 250 W of heat at 60C at a drive ratio of 3.6 % and 200 W at 80C at a drive ratio of 3.5 %. The performance for both cases is about 40% of the Carnot performance. The design, construction, and performance measurements of the heat pump will be presented and discussed.

  12. Heat pipe turbine vane cooling

    Energy Technology Data Exchange (ETDEWEB)

    Langston, L.; Faghri, A. [Univ. of Connecticut, Storrs, CT (United States)

    1995-10-01

    The applicability of using heat pipe principles to cool gas turbine vanes is addressed in this beginning program. This innovative concept involves fitting out the vane interior as a heat pipe and extending the vane into an adjacent heat sink, thus transferring the vane incident heat transfer through the heat pipe to heat sink. This design provides an extremely high heat transfer rate and an uniform temperature along the vane due to the internal change of phase of the heat pipe working fluid. Furthermore, this technology can also eliminate hot spots at the vane leading and trailing edges and increase the vane life by preventing thermal fatigue cracking. There is also the possibility of requiring no bleed air from the compressor, and therefore eliminating engine performance losses resulting from the diversion of compressor discharge air. Significant improvement in gas turbine performance can be achieved by using heat pipe technology in place of conventional air cooled vanes. A detailed numerical analysis of a heat pipe vane will be made and an experimental model will be designed in the first year of this new program.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-01-01

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

  14. Heat Flux Sensors for Infrared Thermography in Convective Heat Transfer

    OpenAIRE

    Giovanni Maria Carlomagno; Luigi de Luca; Gennaro Cardone; Tommaso Astarita

    2014-01-01

    This paper reviews the most dependable heat flux sensors, which can be used with InfraRed (IR) thermography to measure convective heat transfer coefficient distributions, and some of their applications performed by the authors’ research group at the University of Naples Federico II. After recalling the basic principles that make IR thermography work, the various heat flux sensors to be used with it are presented and discussed, describing their capability to investigate complex thermo-fluid-dy...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-01-01

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

  16. Magnetic Heat Pump Containing Flow Diverters

    Science.gov (United States)

    Howard, Frank S.

    1995-01-01

    Proposed magnetic heat pump contains flow diverters for suppression of undesired flows. If left unchecked, undesired flows mix substantial amounts of partially heated and partially cooled portions of working fluid, effectively causing leakage of heat from heated side to cooled side. By reducing leakage of heat, flow diverters increase energy efficiency of magnetic heat pump, potentially offering efficiency greater than compressor-driven refrigerator.

  17. Magnetic Heat Pump Containing Flow Diverters

    Science.gov (United States)

    Howard, Frank S.

    1995-01-01

    Proposed magnetic heat pump contains flow diverters for suppression of undesired flows. If left unchecked, undesired flows mix substantial amounts of partially heated and partially cooled portions of working fluid, effectively causing leakage of heat from heated side to cooled side. By reducing leakage of heat, flow diverters increase energy efficiency of magnetic heat pump, potentially offering efficiency greater than compressor-driven refrigerator.

  18. Mechanisms of Ocean Heat Uptake

    Science.gov (United States)

    Garuba, Oluwayemi

    An important parameter for the climate response to increased greenhouse gases or other radiative forcing is the speed at which heat anomalies propagate downward in the ocean. Ocean heat uptake occurs through passive advection/diffusion of surface heat anomalies and through the redistribution of existing temperature gradients due to circulation changes. Atlantic meridional overturning circulation (AMOC) weakens in a warming climate and this should slow the downward heat advection (compared to a case in which the circulation is unchanged). However, weakening AMOC also causes a deep warming through the redistributive effect, thus increasing the downward rate of heat propagation compared to unchanging circulation. Total heat uptake depends on the combined effect of these two mechanisms. Passive tracers in a perturbed CO2 quadrupling experiments are used to investigate the effect of passive advection and redistribution of temperature anomalies. A new passive tracer formulation is used to separate ocean heat uptake into contributions due to redistribution and passive advection-diffusion of surface heating during an ocean model experiment with abrupt increase in surface temperature. The spatial pattern and mechanisms of each component are examined. With further experiments, the effects of surface wind, salinity and temperature changes in changing circulation and the resulting effect on redistribution in the individual basins are isolated. Analysis of the passive advection and propagation path of the tracer show that the Southern ocean dominates heat uptake, largely through vertical and horizontal diffusion. Vertical diffusion transports the tracer across isopycnals down to about 1000m in 100 years in the Southern ocean. Advection is more important in the subtropical cells and in the Atlantic high latitudes, both with a short time scale of about 20 years. The shallow subtropical cells transport the tracer down to about 500m along isopycnal surfaces, below this vertical

  19. Hybrid Heat Pipes for High Heat Flux Applications Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The thermal transport requirements for future spacecraft missions continue to increase, approaching several kilowatts. At the same time the heat acquisition areas...

  20. Temperature Distribution and Heat Saturating Time of Regenerative Heat Transfer

    Institute of Scientific and Technical Information of China (English)

    Li JIA; Ying MAO; Lixin YANG

    2006-01-01

    In this paper, heat transfer of the ceramic honeycomb regenerator was numerically simulated based on the computational fluid dynamics numerical analysis software CFX5. The longitudinal temperature distribution of regenerator and gas were obtained. The variation of temperature with time was discussed. In addition, the effects of some parameters such as switching time, gas temperature at the inlet of regenerator, height of regenerator and specific heat of the regenerative materials on heat saturating time were discussed. It provided primarily theoretic basis for further study of regenerative heat transfer mechanism.

  1. Large-scale solar heating

    Energy Technology Data Exchange (ETDEWEB)

    Tolonen, J.; Konttinen, P.; Lund, P. [Helsinki Univ. of Technology, Otaniemi (Finland). Advanced Energy Systems

    1998-10-01

    Solar heating market is growing in many European countries and annually installed collector area has exceeded one million square meters. There are dozens of collector manufacturers and hundreds of firms making solar heating installations in Europe. One tendency in solar heating is towards larger systems. These can be roof integrated, consisting of some tens or hundreds of square meters of collectors, or they can be larger centralized solar district heating plants consisting of a few thousand square meters of collectors. The increase of size can reduce the specific investments of solar heating systems, because e.g. the costs of some components (controllers, pumps, and pipes), planning and installation can be smaller in larger systems. The solar heat output can also be higher in large systems, because more advanced technique is economically viable

  2. Heat exchanger leakage problem location

    Directory of Open Access Journals (Sweden)

    Jícha Miroslav

    2012-04-01

    Full Text Available Recent compact heat exchangers are very often assembled from numerous parts joined together to separate heat transfer fluids and to form the required heat exchanger arrangement. Therefore, the leak tightness is very important property of the compact heat exchangers. Although, the compact heat exchangers have been produced for many years, there are still technological problems associated with manufacturing of the ideal connection between the individual parts, mainly encountered with special purpose heat exchangers, e.g. gas turbine recuperators. This paper describes a procedure used to identify the leakage location inside the prime surface gas turbine recuperator. For this purpose, an analytical model of the leaky gas turbine recuperator was created to assess its performance. The results obtained are compared with the experimental data which were acquired during the recuperator thermal performance analysis. The differences between these two data sets are used to indicate possible leakage areas.

  3. Heat exchanger leakage problem location

    Science.gov (United States)

    Hejčík, Jiří; Jícha, Miroslav

    2012-04-01

    Recent compact heat exchangers are very often assembled from numerous parts joined together to separate heat transfer fluids and to form the required heat exchanger arrangement. Therefore, the leak tightness is very important property of the compact heat exchangers. Although, the compact heat exchangers have been produced for many years, there are still technological problems associated with manufacturing of the ideal connection between the individual parts, mainly encountered with special purpose heat exchangers, e.g. gas turbine recuperators. This paper describes a procedure used to identify the leakage location inside the prime surface gas turbine recuperator. For this purpose, an analytical model of the leaky gas turbine recuperator was created to assess its performance. The results obtained are compared with the experimental data which were acquired during the recuperator thermal performance analysis. The differences between these two data sets are used to indicate possible leakage areas.

  4. Heat Transfer Basics and Practice

    CERN Document Server

    Böckh, Peter

    2012-01-01

    The book provides an easy way to understand the fundamentals of heat transfer. The reader will acquire the ability to design and analyze heat exchangers. Without extensive derivation of the fundamentals, the latest correlations for heat transfer coefficients and their application are discussed. The following topics are presented - Steady state and transient heat conduction - Free and forced convection - Finned surfaces - Condensation and boiling - Radiation - Heat exchanger design - Problem-solving After introducing the basic terminology, the reader is made familiar with the different mechanisms of heat transfer. Their practical application is demonstrated in examples, which are available in the Internet as MathCad files for further use. Tables of material properties and formulas for their use in programs are included in the appendix. This book will serve as a valuable resource for both students and engineers in the industry. The author’s experience indicates that students, after 40 lectures and exercises ...

  5. Magnetic heat pump flow director

    Science.gov (United States)

    Howard, Frank S. (Inventor)

    1995-01-01

    A fluid flow director is disclosed. The director comprises a handle body and combed-teeth extending from one side of the body. The body can be formed of a clear plastic such as acrylic. The director can be used with heat exchangers such as a magnetic heat pump and can minimize the undesired mixing of fluid flows. The types of heat exchangers can encompass both heat pumps and refrigerators. The director can adjust the fluid flow of liquid or gas along desired flow directions. A method of applying the flow director within a magnetic heat pump application is also disclosed where the comb-teeth portions of the director are inserted into the fluid flow paths of the heat pump.

  6. Large-scale solar heat

    Energy Technology Data Exchange (ETDEWEB)

    Tolonen, J.; Konttinen, P.; Lund, P. [Helsinki Univ. of Technology, Otaniemi (Finland). Dept. of Engineering Physics and Mathematics

    1998-12-31

    In this project a large domestic solar heating system was built and a solar district heating system was modelled and simulated. Objectives were to improve the performance and reduce costs of a large-scale solar heating system. As a result of the project the benefit/cost ratio can be increased by 40 % through dimensioning and optimising the system at the designing stage. (orig.)

  7. Cluster banding heat source model

    Institute of Scientific and Technical Information of China (English)

    Zhang Liguo; Ji Shude; Yang Jianguo; Fang Hongyuan; Li Yafan

    2006-01-01

    Concept of cluster banding heat source model is put forward for the problem of overmany increment steps in the process of numerical simulation of large welding structures, and expression of cluster banding heat source model is deduced based on energy conservation law.Because the expression of cluster banding heat source model deduced is suitable for random weld width, quantitative analysis of welding stress field for large welding structures which have regular welds can be made quickly.

  8. Boiler Stack Gas Heat Recovery

    Science.gov (United States)

    1987-09-01

    recover about 17 million Btu/hr. The fact that the exhaust gas was loaded with fiber made the spray recu- perator a prime candidate since it could also wash... properties of water, heating feedwater is more effective than heating air. Research in heat-recovery material technology has identified materials which are...and Acidic fluids up to 180 OF. Piping Fans and Blowers 350 OF flue gas. Scrubbers 300 to 350 OF bagasse flue gas, trash burner flue gas. Electrostatic

  9. Heat Roadmap Europe 3 (STRATEGO)

    DEFF Research Database (Denmark)

    Connolly, David; Hansen, Kenneth; Drysdale, David

    Heat Roadmap Europe 3 is from work package 2 of the STRATEGO project (http://stratego-project.eu/). It quantifies the impact of implementing various energy efficiency measures in the heating and cooling sectors of five EU Member States: Czech Republic, Croatia, Italy, Romania, and the United King...... States to simultaneously reduce energy demand, imported fossil fuels, carbon dioxide emissions, and the cost of the heating, cooling, and electricity sectors....

  10. Enhanced heat transfer using nanofluids

    Science.gov (United States)

    Choi, Stephen U. S.; Eastman, Jeffrey A.

    2001-01-01

    This invention is directed to a method of and apparatus for enhancing heat transfer in fluids such as deionized water. ethylene glycol, or oil by dispersing nanocrystalline particles of substances such as copper, copper oxide, aluminum oxide, or the like in the fluids. Nanocrystalline particles are produced and dispersed in the fluid by heating the substance to be dispersed in a vacuum while passing a thin film of the fluid near the heated substance. The fluid is cooled to control its vapor pressure.

  11. Heat stress in growing pigs

    OpenAIRE

    Huynh Thi Thanh Thuy

    2005-01-01

    Compared to other species of farm animals, pigs are more sensitive to high environmental temperatures, because they cannot sweat and do not pant so well. Furthermore, fast-growing lean pigs generate more heat than their congeners living in the wild. This, in combination with confined housing, makes it difficult for these pigs to regulate their heat balance. Heat stressed pigs have low performance, poor welfare, and, by pen fouling, they give higher emissions of odour and ammonia.Above certain...

  12. Peltier heat pumps. Peltiervaermepumpar

    Energy Technology Data Exchange (ETDEWEB)

    Torstensson, H. (Studsvik Energy, Nykoeping (SE))

    1990-06-01

    Todays Peltier devices in heat pump applications gives a low coeffificent of performance. A temperature difference of 40 deg C results in a COP-value of approx. 1.3. Peltier devices are manufactured of alloys composed of heavy elements like tellurium, selenium, bismuth and antimony. These elements thermoelectrical properties, figure of merit are decisive to the performance of the Peltier devices. An upper limit for the figure of merit, ZT, is said to be 2, which at {Delta}T=40 deg C would yield a COP of 2.0 as a maximum. Organic compounds have been investigated with regard to the electric conductivity. Thin film technique have been used for Peltier devices in micro-scale. There are no large-scale applications. The method does not give enhanced termoelectrical properties, but more rational and cheaper manufacturing. (author) (47 refs., 26 figs.).

  13. Poisoning of Heat Pipes

    Science.gov (United States)

    Gillies, Donald; Lehoczky, Sandor; Palosz, Witold; Carpenter, Paul; Salvail, Pat

    2007-01-01

    Thermal management is critical to space exploration efforts. In particular, efficient transfer and control of heat flow is essential when operating high energy sources such as nuclear reactors. Thermal energy must be transferred to various energy conversion devices, and to radiators for safe and efficient rejection of excess thermal energy. Applications for space power demand exceptionally long periods of time with equipment that is accessible for limited maintenance only. Equally critical is the hostile and alien environment which includes high radiation from the reactor and from space (galactic) radiation. In space or lunar applications high vacuum is an issue, while in Martian operations the systems will encounter a CO2 atmosphere. The effect of contact at high temperature with local soil (regolith) in surface operations on the moon or other terrestrial bodies (Mars, asteroids) must be considered.

  14. Heat flux solarimeter

    Energy Technology Data Exchange (ETDEWEB)

    Sartarelli, A.; Vera, S.; Cyrulies, E. [Instituto de Desarrollo Humano, Univ. Nac. de Gral. Sarmiento (IDH, UNGS), Los Polvorines (Argentina); Echarri, R. [Instituto de Desarrollo Humano, Univ. Nac. de Gral. Sarmiento (IDH, UNGS), Los Polvorines (Argentina); Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET) (Argentina); Samson, I. [INTEC (Instituto Tecnologico Santo Domingo), Santo Domingo (Dominican Republic)

    2010-12-15

    The solarimeter presented in this work is easy to assemble. It is calibrated and its performance is validated by means of Hottel's method. Finally, the curves obtained with this solarimeter are compared to the ones obtained with a commercial solarimeter. This device is based on the evaluation of the heat flow in a metal rod. In consequence, measurements are not affected by ambient temperature variations. On the other hand, there is a linear relationship between the temperatures measured at the rod ends and the incident radiation, as can be concluded both from the theory of its operation and the calibration lines obtained. The results obtained from the global irradiance measurements in the area of Los Polvorines (Buenos Aires Province), together with a preliminary evaluation of the solarimeter's response time, are presented in this work. (author)

  15. Heat transfer physics

    CERN Document Server

    Kaviany, Massoud

    2014-01-01

    This graduate textbook describes atomic-level kinetics (mechanisms and rates) of thermal energy storage, transport (conduction, convection, and radiation), and transformation (various energy conversions) by principal energy carriers. The approach combines the fundamentals of molecular orbitals-potentials, statistical thermodynamics, computational molecular dynamics, quantum energy states, transport theories, solid-state and fluid-state physics, and quantum optics. The textbook presents a unified theory, over fine-structure/molecular-dynamics/Boltzmann/macroscopic length and time scales, of heat transfer kinetics in terms of transition rates and relaxation times, and its modern applications, including nano- and microscale size effects. Numerous examples, illustrations, and homework problems with answers that enhance learning are included. This new edition includes applications in energy conversion (including chemical bond, nuclear, and solar), expanded examples of size effects, inclusion of junction quantum tr...

  16. Solar heating wall

    Energy Technology Data Exchange (ETDEWEB)

    Schoenfelder, J.L.

    1983-08-16

    A solar heating wall is disclosed including a water pipe circulation system having a plurality of separate tubes, each formed as a loop, connected between a water supply and a return. The separate tubes are arranged in a single vertical plane at the approximate center of the wall. The wall is formed within a frame which is packed with a material suited for use as a thERMAL RESERVOIR, SUCH AS concrete. The frame provides extra support by having a series of horizontally disposed cross supports on one surface of the wall and a series of vertically disposed cross supports on the opposite surface A pressure relief valve may be provided between the water supply to the separate tubes and the water supply to the building or structure containing the solar wall, so that the solar wall can be adapted for use with a city water system.

  17. Combined Heat and Power

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2008-07-01

    At their 2007 Summit in Heiligendamm, G8 leaders called on countries to 'adopt instruments and measures to significantly increase the share of combined heat and power (CHP) in the generation of electricity.' As a result, energy, economic, environmental and utility regulators are looking for tools and information to understand the potential of CHP and to identify appropriate policies for their national circumstances. This report forms the first part of the response. It includes answers to policy makers' questions about the potential economic, energy and environmental benefits of an increased policy commitment to CHP. It also includes for the first time integrated IEA data on global CHP installations, and analyses the benefits of increased CHP investment in the G8+5 countries. A companion report will be produced later in 2008 to document best practice policy approaches that have been used to expand the use of CHP in a variety of countries.

  18. Holographic Heat Engines

    CERN Document Server

    Johnson, Clifford V

    2014-01-01

    It is shown that in theories of gravity where the cosmological constant is considered a thermodynamic variable, it is natural to use black holes as heat engines. Two examples are presented in detail using AdS charged black holes as the working substance. We notice that for static black holes, the maximally efficient traditional Carnot engine is also a Stirling engine. The case of negative cosmological constant supplies a natural realization of these engines in terms of the field theory description of the fluids to which they are holographically dual. We first propose a precise picture of how the traditional thermodynamic dictionary of holography is extended when the cosmological constant is dynamical and then conjecture that the engine cycles can be performed by using renormalization group flow. We speculate about the existence of a natural dual field theory counterpart to the gravitational thermodynamic volume.

  19. Users of electric heating rewarded

    Energy Technology Data Exchange (ETDEWEB)

    Haapakoski, M. [ed.

    1998-07-01

    When the building industry plunged into the deep recession of the early 1990s this did not paralyse research and development work on electric heating. In fact, IVO and power companies launched the `Electrically Heated Homes in the New Millennium` project in 1992. Its purpose was to verify the efficiency, energy economy and residential comfort of model systems using state-of-the-art electric heating technology. The research project launched six years ago is now nearing completion. Its findings indicate that electricity brings ever more unparalleled benefits when it is used for heating. These benefits involve residential comfort, ease of use and economy

  20. Ergonomics of heat and cold.

    Science.gov (United States)

    Kamon, E

    1975-01-01

    The biophysical, physiological and some of the psychological aspects of work under unfavorable man-made ambient conditions are presented in light of the need to prevent excessive strain. Work is treated in two ways: 1) in terms of the muscles O2 demand as a fraction of maximal aerobic capacity; and 2) in terms of metabolic heat source. Since maximal aerobic capacity depends on factors such as physical fitness, age and sex, these factors require consideration in estimating strain due to work. The absolute metabolic heat (M) produced during work is needed in the consideration of the total heat balance. Radiation (r), convection (C), and, under some circumstances, evaporation (Eev) are the main avenues of heat exchange between man and his immediate environment. Eev is primarily a function of the ambient potential for evaporation (Emax). Since the relation of the sum M+R+C to Emax determines heat balance when man in under a heat load, evaluation of the avenues of heat exchange, the sources of heat load, and the stressing effect of all these on the physiological responses are treated in some detail. Psychrometrically defined limits of exposure are also discussed. Subjective sensation and mental performance are discussed in light of their correlation with physiological responses to heat. Cold is treated mainly from the point of view of safety and protective clothing.

  1. Geothermal heating systems for greenhouses

    Energy Technology Data Exchange (ETDEWEB)

    Silva, J.F.; Johnson, W.C.

    1980-08-12

    Ways to utilize low-temperature geothermally heated water for a flow-through system are presented. The geothermal energy used for this system is the waste heat discharged from space heating 500,000 square feet of floor space at Oregon Institute of Technology with geothermal water pumped directly from the campus wells. The information collected and analyzed is from data developed from operating a greenhouse on the Oregon Institute of Technology campus from December 1979 to April 1980. Methods for calculating heating requirements of greenhouses using geothermal energy were developed from the analyses of the data obtained. (MHR)

  2. The theory of heat radiation

    CERN Document Server

    Planck, Max

    2003-01-01

    Nobel laureate's classic exposition of the theory of radiant heat in terms of quantum action. Kirchoff's law, black radiation, Maxwell's radiation pressure, entropy, other topics. 1914 edition. Bibliography.

  3. Urban Heat Wave Hazard Assessment

    Science.gov (United States)

    Quattrochi, D. A.; Jedlovec, G.; Crane, D. L.; Meyer, P. J.; LaFontaine, F.

    2016-12-01

    Heat waves are one of the largest causes of environmentally-related deaths globally and are likely to become more numerous as a result of climate change. The intensification of heat waves by the urban heat island effect and elevated humidity, combined with urban demographics, are key elements leading to these disasters. Better warning of the potential hazards may help lower risks associated with heat waves. Moderate resolution thermal data from NASA satellites is used to derive high spatial resolution estimates of apparent temperature (heat index) over urban regions. These data, combined with demographic data, are used to produce a daily heat hazard/risk map for selected cities. MODIS data are used to derive daily composite maximum and minimum land surface temperature (LST) fields to represent the amplitude of the diurnal temperature cycle and identify extreme heat days. Compositing routines are used to generate representative daily maximum and minimum LSTs for the urban environment. The limited effect of relative humidity on the apparent temperature (typically 10-15%) allows for the use of modeled moisture fields to convert LST to apparent temperature without loss of spatial variability. The daily max/min apparent temperature fields are used to identify abnormally extreme heat days relative to climatological values in order to produce a heat wave hazard map. Reference to climatological values normalizes the hazard for a particular region (e.g., the impact of an extreme heat day). A heat wave hazard map has been produced for several case study periods and then computed on a quasi-operational basis during the summer of 2016 for Atlanta, GA, Chicago, IL, St. Louis, MO, and Huntsville, AL. A hazard does not become a risk until someone or something is exposed to that hazard at a level that might do harm. Demographic information is used to assess the urban risk associated with the heat wave hazard. Collectively, the heat wave hazard product can warn people in urban

  4. CRBRP decay heat removal systems

    Energy Technology Data Exchange (ETDEWEB)

    Hottel, R. E.; Louison, R.; Boardman, C. E.; Kiley, M. J.

    1977-01-01

    The Decay Heat Removal Systems for the Clinch River Breeder Reactor Plant (CRBRP) are designed to adequately remove sensible and decay heat from the reactor following normal shutdown, operational occurrences, and postulated accidents on both a short term and a long term basis. The Decay Heat Removal Systems are composed of the Main Heat Transport System, the Main Condenser and Feedwater System, the Steam Generator Auxiliary Heat Removal System (SGAHRS), and the Direct Heat Removal Service (DHRS). The overall design of the CRBRP Decay Heat Removal Systems and the operation under normal and off-normal conditions is examined. The redundancies of the system design, such as the four decay heat removal paths, the emergency diesel power supplies, and the auxiliary feedwater pumps, and the diversities of the design such as forced circulation/natural circulation and AC Power/DC Power are presented. In addition to overall design and system capabilities, the detailed designs for the Protected Air Cooled Condensers (PACC) and the Air Blast Heat Exchangers (ABHX) are presented.

  5. Industrial heat pump assessment study

    Science.gov (United States)

    Chappell, R. N.; Priebe, S. J.; Wilfert, G. L.

    1989-03-01

    This report summarizes preliminary studies that assess the potential of industrial heat pumps for reduction of process heating requirements in industries receiving power from the Bonneville Power Administration (BPA). This project was initiated at the request of BPA to determine the potential of industrial heat pumps in BPA's service area. Working from known heat pump principles and from a list of BPA's industrial customers, the authors estimated the fuel savings potential for six industries. Findings indicate that the pulp and paper industry would yield the greatest fuel savings and increased electrical consumption. Assessments presented in this report represent a cooperative effort between The Idaho National Engineering Laboratory (INEL), and Battelle-Northwest Laboratories.

  6. Portable Heat Pump Testing Device

    Directory of Open Access Journals (Sweden)

    Kłosowiak R.

    2015-08-01

    Full Text Available The aim of this paper is to present the design and working principle of a portable testing device for heat pumps in the energy recirculation system. The presented test stand can be used for any refrigerating/reverse flow cycle device to calculate the device energy balance. The equipment is made of two portable containers of the capacity of 250 liters to simulate the air heat source and ground heat source with a system of temperature stabilization, compressor heat pump of the coefficient of performance (COP of = 4.3, a failsafe system and a control and measurement system.

  7. Heat Flux Instrumentation Laboratory (HFIL)

    Data.gov (United States)

    Federal Laboratory Consortium — Description: The Heat Flux Instrumentation Laboratory is used to develop advanced, flexible, thin film gauge instrumentation for the Air Force Research Laboratory....

  8. Inductive Electron Heating Revisited

    Science.gov (United States)

    Tuszewski, M.

    1996-11-01

    Inductively Coupled Plasmas (ICPs) have been studied for over a century. Recently, ICPs have been rediscovered by the multi-billion dollar semiconductor industry as an important class of high-density, low-pressure plasma sources suitable for the manufacture of next-generation integrated circuits. Present low-pressure ICP development is among the most active areas of plasma research. However, this development remains largely empirical, a prohibitively expensive approach for upcoming 300-mm diameter wafers. Hence, there is an urgent need for basic ICP plasma physics research, including experimental characterization and predictive numerical modeling. Inductive radio frequency (rf) power absorption is fundamental to the ICP electron heating and the resulting plasma transport but remains poorly understood. For example, recent experimental measurements and supporting fluid calculationsfootnote M. Tuszewski, Phys. Rev. Lett. 77 in press (1996) on a commercial deposition tool prototype show that the induced rf magnetic fields in the source can cause an order of magnitude reduction in plasma conductivity and in electron heating power density. In some cases, the rf fields penetrate through the entire volume of the ICP discharges while existing models that neglect the induced rf magnetic fields predict rf absorption in a thin skin layer near the plasma surface. The rf magnetic fields also cause more subtle changes in the plasma density and in the electron temperature spatial distributions. These data will be presented and the role of basic research in the applied world of semiconductor manufacturing will be discussed. ^*This research was conducted under the auspices of the U.S. DOE, supported by funds provided by the University of California for discretionary research by Los Alamos National Laboratory.

  9. Gas turbine heat transfer and cooling technology

    CERN Document Server

    Han, Je-Chin; Ekkad, Srinath

    2012-01-01

    FundamentalsNeed for Turbine Blade CoolingTurbine-Cooling TechnologyTurbine Heat Transfer and Cooling IssuesStructure of the BookReview Articles and Book Chapters on Turbine Cooling and Heat TransferNew Information from 2000 to 2010ReferencesTurbine Heat TransferIntroductionTurbine-Stage Heat TransferCascade Vane Heat-Transfer ExperimentsCascade Blade Heat TransferAirfoil Endwall Heat TransferTurbine Rotor Blade Tip Heat TransferLeading-Edge Region Heat TransferFlat-Surface Heat TransferNew Information from 2000 to 20102.10 ClosureReferencesTurbine Film CoolingIntroductionFilm Cooling on Rotat

  10. Measurement and Evaluation of Heating Performance of Heat Pump Systems Using Wasted Heat from Electric Devices for an Electric Bus

    OpenAIRE

    Moo-Yeon Lee; Jong-Phil Won; Chung-Won Cho; Ho-Seong Lee

    2012-01-01

    The objective of this study is to investigate heating performance characteristics of a coolant source heat pump using the wasted heat from electric devices for an electric bus. The heat pump, using R-134a, is designed for heating a passengers’ compartment by using discharged energy from the coolant of electric devices, such as motors and inverters of the electric bus. The heating performance of the heat pump was tested by varying the operating parameters, such as outdoor temperature and volum...

  11. Evaluation of complex heat transfer coefficients for passive heating concepts

    Energy Technology Data Exchange (ETDEWEB)

    Bansal, N.K.; Sodha, M.S.; Singh, S.P.; Ram, S.

    1987-01-01

    Passive heating concepts namely Trombe wall, Water wall and Trans wall have been analysed to obtain overall heat transfer coefficients for average values and for time-dependent variations. The numerical values have been obtained and tabulated for various wall thicknesses.

  12. Numerical study of heat transfer characteristics in BOG heat exchanger

    Science.gov (United States)

    Yan, Yan; Pfotenhauer, John M.; Miller, Franklin; Ni, Zhonghua; Zhi, Xiaoqin

    2016-12-01

    In this study, a numerical study of turbulent flow and the heat transfer process in a boil-off liquefied natural gas (BOG) heat exchanger was performed. Finite volume computational fluid dynamics and the k - ω based shear stress transport model were applied to simulate thermal flow of BOG and ethylene glycol in a full-sized 3D tubular heat exchanger. The simulation model has been validated and compared with the engineering specification data from its supplier. In order to investigate thermal characteristics of the heat exchanger, velocity, temperature, heat flux and thermal response were studied under different mass flowrates in the shell-side. The shell-side flow pattern is mostly determined by viscous forces, which lead to a small velocity and low temperature buffer area in the bottom-right corner of the heat exchanger. Changing the shell-side mass flowrate could result in different distributions of the shell-side flow. However, the distribution in the BOG will remain in a relatively stable pattern. Heat flux increases along with the shell-side mass flowrate, but the increase is not linear. The ratio of increased heat flux to the mass flow interval is superior at lower mass flow conditions, and the threshold mass flow for stable working conditions is defined as greater than 0.41 kg/s.

  13. What Is Heat? Inquiry regarding the Science of Heat

    Science.gov (United States)

    Rascoe, Barbara

    2010-01-01

    This lab activity uses inquiry to help students define heat. It is generic in that it can be used to introduce a plethora of science content across middle and high school grade levels and across science disciplines that include biology, Earth and space science, and physical science. Even though heat is a universal science phenomenon that is…

  14. A heat transfer model of a horizontal ground heat exchanger

    Science.gov (United States)

    Mironov, R. E.; Shtern, Yu. I.; Shtern, M. Yu.; Rogachev, M. S.

    2016-04-01

    Ground-source heat pumps are gaining popularity in Eastern Europe, especially those which are using the horizontal ground heat exchanger (GHX). Due to the difficulty of accessing GHX after the installation, materials and the quality of the installation must satisfy the very high requirements. An inaccurate calculation of GHX can be the reason of a scarcity of heat power in a crucial moment. So far, there isn't any appropriate mathematical description of the horizontal GHX which takes into account the mutual influence of GHX pipes on each other. To solve this problem we used the temperature wave approach. As a result, a mathematical model which describes the dependence of the heat transfer rate per unit length of the horizontal GHX pipe on the thermal properties of soil, operating time of GHX and the distance between pipes was obtained. Using this model, heat transfer rates per unit length of a horizontal GHX were plotted as functions of the distance between pipes and operating time. The modeling shows that heat transfer rates decreases rapidly with the distance between pipes lower then 2 meters. After the launch of heat pump, heat power of GHX is reduced during the first 20 - 30 days and get steady after that. The obtained results correlate with experimental data. Therefore the proposed mathematical model can be used to design a horizontal GHX with the optimal characteristics, and predict its capability during operation.

  15. Mass and Heat Transfer Enhancement of Chemical Heat Pumps

    Institute of Scientific and Technical Information of China (English)

    Gui-PingLin; Xiu-GanYuan

    1993-01-01

    An inert additive,expanded graphit(EG),has been prepared and used to enhance the heat and mass transfer process of chemical heat pumps.The effects of mixing ratio and mixing method on the chemical reaction time are investigated.

  16. 24 CFR 3280.506 - Heat loss/heat gain.

    Science.gov (United States)

    2010-04-01

    ... URBAN DEVELOPMENT MANUFACTURED HOME CONSTRUCTION AND SAFETY STANDARDS Thermal Protection § 3280.506 Heat... assure uniform heat transmission in manufactured homes, cavities in exterior walls, floors, and ceilings shall be provided with thermal insulation. (c) Manufactured homes designed for Uo Value Zone 3 shall...

  17. Some Aspects Concerning Convective Circulation Mode of Heat Transfer in Furnace to Wood Heat Treatment

    Directory of Open Access Journals (Sweden)

    Nadia Potoceanu

    2007-10-01

    Full Text Available The paper presented the most aspects of convective circulate mode of heat transfer : heat transfer through the boundary layer formed at the surface of the heat generator; heat transfer in the heat carrier and heat transfer through the boundary layer formed at the heated surface

  18. Heat Transfer of Nanofluid in a Double Pipe Heat Exchanger.

    Science.gov (United States)

    Aghayari, Reza; Maddah, Heydar; Zarei, Malihe; Dehghani, Mehdi; Kaskari Mahalle, Sahar Ghanbari

    2014-01-01

    This paper investigates the enhancement of heat transfer coefficient and Nusselt number of a nanofluid containing nanoparticles (γ-AL2O3) with a particle size of 20 nm and volume fraction of 0.1%-0.3% (V/V). Effects of temperature and concentration of nanoparticles on Nusselt number changes and heat transfer coefficient in a double pipe heat exchanger with counter turbulent flow are investigated. Comparison of experimental results with valid theoretical data based on semiempirical equations shows an acceptable agreement. Experimental results show a considerable increase in heat transfer coefficient and Nusselt number up to 19%-24%, respectively. Also, it has been observed that the heat transfer coefficient increases with the operating temperature and concentration of nanoparticles.

  19. Crawl space assisted heat pump. [using stored ground heat

    Science.gov (United States)

    Ternes, M. P.

    1980-01-01

    A variety of experiments and simulations, currently being designed or underway, to determine the feasibility of conditioning the source air of an air to air heat pump using stored ground heat or cool to produce higher seasonal COP's and net energy savings are discussed. The ground would condition ambient air as it is drawn through the crawl space of a house. Tests designed to evaluate the feasibility of the concept, to determine the amount of heat or cool available from the ground, to study the effect of the system on the heating and cooling loads of the house, to study possible mechanisms which could enhance heat flow through the ground, and to determine if diurnal temperature swings are necessary to achieve successful system performance are described.

  20. Fundamental Study of a Combined Hyperthermia System with RF Capacitive Heating and Interstitial Heating

    OpenAIRE

    Saitoh, Yoshiaki; Hori, Junichi; 斉藤, 義明; 堀, 潤一

    2001-01-01

    Interstitial RF heating with an inserted electrode allows the heating position selection in a subject, but the narrow heating region is problematic. This study elucidates development of new interstitial RF heating methods, combining with external RF heating using paired electrodes, heating the subject broadly in advance in order to selectively extend the heating region. Two kinds of heating system were developed by controlling a differential mode and a common mode of RF currents. Heating expe...