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Sample records for rtg heat source

  1. GPHS-RTG system explosion test direct course experiment 5000. [General Purpose Heat Source-Radioisotope Thermoelectric Generator

    Energy Technology Data Exchange (ETDEWEB)

    1984-03-01

    The General Purpose Heat Source-Radioisotope Thermoelectric Generator (GPHS-RTG) has been designed and is being built to provide electrical power for spacecrafts to be launched on the Space Shuttle. The objective of the RTG System Explosion Test was to expose a mock-up of the GPHS-RTG with a simulated heat source to the overpressure and impulse representative of a potential upper magnitude explosion of the Space Shuttle. The test was designed so that the heat source module would experience an overpressure at which the survival of the fuel element cladding would be expected to be marginal. Thus, the mock-up was placed where the predicted incident overpressure would be 1300 psi. The mock-up was mounted in an orientation representative of the launch configuration on the spacecraft to be used on the NASA Galileo Mission. The incident overpressure measured was in the range of 1400 to 2100 psi. The mock-up and simulated heat source were destroyed and only very small fragments were recovered. This damage is believed to have resulted from a combination of the overpressure and impact by very high velocity fragments from the ANFO sphere. Post-test analysis indicated that extreme working of the iridium clad material occurred, indicative of intensive impulsive loading on the metal.

  2. RTG Waste Heat System for the Cassini Propulsion Module

    Science.gov (United States)

    Mireles, V.; Stultz, J.

    1994-01-01

    This paper describes the thermal design for the propulsion module subsystem (PMS), and presents the results from the radioisotope thermoelectric generator (RTG) waste heat thermal test, and it summarizes the adjustment techniques and their relative effectiveness; it also shows the resulting predicted PMS flight temperatures relative to the requirements.

  3. On thermal stress failure of the SNAP-19A RTG heat shield

    Science.gov (United States)

    Pitts, W. C.; Anderson, L. A.

    1974-01-01

    Results of a study on thermal stress problems in an amorphous graphite heat shield that is part of the launch-abort protect system for the SNAP-19A radio-isotope thermoelectric generators (RTG) that will be used on the Viking Mars Lander are presended. The first result is from a thermal stress analysis of a full-scale RTG heat source that failed to survive a suborbital entry flight test, possibly due to thermal stress failure. It was calculated that the maximum stress in the heat shield was only 50 percent of the ultimate strength of the material. To provide information on the stress failure criterion used for this calculation, some heat shield specimens were fractured under abort entry conditions in a plasma arc facility. It was found that in regions free of stress concentrations the POCO graphite heat shield material did fracture when the local stress reached the ultimate uniaxial stress of the material.

  4. Sfp1 and Rtg3 reciprocally modulate carbon source-conditional stress adaptation in the pathogenic yeast Candida albicans.

    Science.gov (United States)

    Kastora, Stavroula L; Herrero-de-Dios, Carmen; Avelar, Gabriela M; Munro, Carol A; Brown, Alistair J P

    2017-08-01

    The pathogenicity of the clinically important yeast, Candida albicans, is dependent on robust responses to host-imposed stresses. These stress responses have generally been dissected in vitro at 30°C on artificial growth media that do not mimic host niches. Yet host inputs, such as changes in carbon source or temperature, are known to affect C. albicans stress adaptation. Therefore, we performed screens to identify novel regulators that promote stress resistance during growth on a physiologically relevant carboxylic acid and at elevated temperatures. These screens revealed that, under these 'non-standard' growth conditions, numerous uncharacterised regulators are required for stress resistance in addition to the classical Hog1, Cap1 and Cta4 stress pathways. In particular, two transcription factors (Sfp1 and Rtg3) promote stress resistance in a reciprocal, carbon source-conditional manner. SFP1 is induced in stressed glucose-grown cells, whereas RTG3 is upregulated in stressed lactate-grown cells. Rtg3 and Sfp1 regulate the expression of key stress genes such as CTA4, CAP1 and HOG1 in a carbon source-dependent manner. These mechanisms underlie the stress sensitivity of C. albicans sfp1 cells during growth on glucose, and rtg3 cells on lactate. The data suggest that C. albicans exploits environmentally contingent regulatory mechanisms to retain stress resistance during host colonisation. © 2017 The Authors. Molecular Microbiology Published by John Wiley & Sons Ltd.

  5. Design and Structural Analysis of Mars Rover RTG

    Energy Technology Data Exchange (ETDEWEB)

    Schock, Alfred; Hamrick, T.; Sankarankandath, V.; Shirbacheh, M.

    1989-09-29

    The paper describes the design and the structural and mass analysis of a Radioisotope Thermoelectric Generators (RTGs) for powering the MARS Rover vehicle, which is a critical element of the unmanned Mars Rover and Sample Return mission (MRSR). The RTG design study was conducted by Fairchild Space Company for the U.S. Department of Energy, in support of the Jet Propulsion Laboratory's MRSR project.; The paper briefly describes a reference mission scenario, an illustrative Rover design and activity pattern on Mars, and its power system requirements and environmental constraints, including the RTG cooling requirements during transit to Mars. It identifies the key RTG design problem, i.e. venting the helium generated by the fuel's alpha decay without intrusion of the Martian atmosphere into the RTG, and proposes a design approach for solving that problem.; Using that approach, it describes a very conservative baseline RTG design. The design is based on the proven and safety-qualified General Purpose Heat Source module, and employs standard thermoelectric unicouples whose reliability and performance stability has been extensively demonstrated on previous space missions. The heat source of the 250-watt RTG consists of a stack of 18 separate modules that is supported at its ends but not along its length. The paper describes and analyzes the structure that holds the stack together during Earth launch and Mars operations but allows it to come apart in case of an inadvertent reentry.; A companion paper presented at this conference describes the RTG's thermal and electrical analysis, and compares its performance with that of several lighter but less conservative design options.; There is a duplicate copy in the ESD files. This document is not relevent to OSTI Library. Do not send.

  6. Silicon Germanium (SiGe) Radioisotope Thermoelectric Generator (RTG) Program for space missions. Fifteenth technical progress report, August 1-31, 1980

    Energy Technology Data Exchange (ETDEWEB)

    Whitmore, C. W.; Silverman, G.

    1980-01-01

    This program consists of the following three tasks: Multi-Hundred Watt RTG for the Galileo Probe Mission; Reestablishment of Silicon Germanium Unicouple Capability; and General Purpose Heat Source RTG for the International Solar Polar and Galileo Orbiter Missions. Details of program progress for each task, including a milestone schedule and a discussion of current problem areas (if any) are presented.

  7. Simulating the Gradually Deteriorating Performance of an RTG

    Science.gov (United States)

    Wood, Eric G.; Ewell, Richard C.; Patel, Jagdish; Hanks, David R.; Lozano, Juan A.; Snyder, G. Jeffrey; Noon, Larry

    2008-01-01

    Degra (now in version 3) is a computer program that simulates the performance of a radioisotope thermoelectric generator (RTG) over its lifetime. Degra is provided with a graphical user interface that is used to edit input parameters that describe the initial state of the RTG and the time-varying loads and environment to which it will be exposed. Performance is computed by modeling the flows of heat from the radioactive source and through the thermocouples, also allowing for losses, to determine the temperature drop across the thermocouples. This temperature drop is used to determine the open-circuit voltage, electrical resistance, and thermal conductance of the thermocouples. Output power can then be computed by relating the open-circuit voltage and the electrical resistance of the thermocouples to a specified time-varying load voltage. Degra accounts for the gradual deterioration of performance attributable primarily to decay of the radioactive source and secondarily to gradual deterioration of the thermoelectric material. To provide guidance to an RTG designer, given a minimum of input, Degra computes the dimensions, masses, and thermal conductances of important internal structures as well as the overall external dimensions and total mass.

  8. Mars Rover RTG Study

    Energy Technology Data Exchange (ETDEWEB)

    Schock, Alfred

    1989-11-27

    This report summarizes the results of a Radioisotope Thermoelectric Generator (RTG) design study conducted by Fairchild Space Company at the direction of the U.S. Department of Energy's Office of Special Applications, in support of the Mars Rover and Sample Return mission under investigation at NASA's Jet Propulsion Laboratory. Presented at the 40th Congress of the IAF, Oct. 7-13, 1989 in Torremolinos, Malaga-Spain. The paper describes the design and analysis of Radioisotope Thermoelectric Generators (RTGs) for powering the Mars Rover vehicle, which is a critical element of the unmanned Mars Rover and Sample Return mission (MRSR). The RTG design study was conducted by Fairchild Space for the U.S. DOE in support of the JPL MRSR Project. The paper briefly describes a reference mission scenario, an illustrative Rover design and activity pattern on Mars, and its power system requirements and environmental constraints, including the RTG cooling requirements during transit to Mars. It summarizes the baseline RTG's mass breakdown, and presents a detailed description of its thermal, thermoelectric, and electrical analysis. The results presented show the RTG performance achievable with current technology, and the performance improvements that would be achievable with various technology developments. It provides a basis for selecting the optimum strategy for meeting the Mars Rover design goals with minimal programmatic risk and cost. Cross Reference CID #7135 dated 10/1989. There is a duplicate copy. This document is not relevant to the OSTI Library. Do not send.

  9. Mars Rover RTG Study

    Energy Technology Data Exchange (ETDEWEB)

    Schock, Alfred

    1989-10-01

    Presented at the 40th Congress of the IAF, Oct. 7-13, 1989 in Torremolinos, Malaga-Spain. The paper describes the design and analysis of Radioisotope Thermoelectric Generators (RTGs) for powering the Mars Rover vehicle, which is a critical element of the unmanned Mars Rover and Sample Return mission (MRSR). The RTG design study was conducted by Fairchild Space for the U.S. DOE in support of the JPL MRSR Project. The paper briefly describes a reference mission scenario, an illustrative Rover design and activity pattern on Mars, and its power system requirements and environmental constraints, including the RTG cooling requirements during transit to Mars. It summarizes the baseline RTG's mass breakdown, and presents a detailed description of its thermal, thermoelectric, and electrical analysis. The results presented show the RTG performance achievable with current technology, and the performance improvements that would be achievable with various technology developments. It provides a basis for selecting the optimum strategy for meeting the Mars Rover design goals with minimal programmatic risk and cost. There is a duplicate copy and three copies in the file.

  10. TAGS 85/2N RTG Power for Viking Lander Capsule

    Science.gov (United States)

    1969-08-01

    Results of studies performed by Isotopes, Inc., Nuclear Systems Division, to optimize and baseline a TAGS 85/2N RTG for the Viking Lander Capsule prime electrical power source are presented. These studies generally encompassed identifying the Viking RTG mission profile and design requirements, and establishing a baseline RTG design consistent with these requirements.

  11. Mars Rover RTG Study

    Energy Technology Data Exchange (ETDEWEB)

    Schock, Alfred

    1989-08-25

    This report summarizes the results of a Radioisotope Thermoelectric Generator (RTG) design study conducted by Fairchild Space Company at the direction of the U.S. Department of Energy's Office of SpecialApplications, in suppport of the Mars Rover and Sample Return mission under investigation at NASA's Jet Propulsion Laboratory. The report is a rearranged, updated, and significantly expanded amalgam of three interrelated papers presented at the 24th Intersocity Energy Conversion Engineering Conference (IECEC) at Arlington, Virginia, on August 10, 1989.

  12. General-purpose heat source: Research and development program, radioisotope thermoelectric generator/thin fragment impact test

    Energy Technology Data Exchange (ETDEWEB)

    Reimus, M.A.H.; Hinckley, J.E.

    1996-11-01

    The general-purpose heat source provides power for space missions by transmitting the heat of {sup 238}Pu decay to an array of thermoelectric elements in a radioisotope thermoelectric generator (RTG). Because the potential for a launch abort or return from orbit exists for any space mission, the heat source response to credible accident scenarios is being evaluated. This test was designed to provide information on the response of a loaded RTG to impact by a fragment similar to the type of fragment produced by breakup of the spacecraft propulsion module system. The results of this test indicated that impact by a thin aluminum fragment traveling at 306 m/s may result in significant damage to the converter housing, failure of one fueled clad, and release of a small quantity of fuel.

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

    Energy Technology Data Exchange (ETDEWEB)

    1991-07-01

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

  14. Design Modifications for Increasing the BOm and EOM Power Output and Reducing the Size and Mass of RTG for the Pluto Mission

    Energy Technology Data Exchange (ETDEWEB)

    Schock, Alfred; Or, Chuen T; Kumar, Vasanth

    1994-08-01

    Paper presented at the 29th IECEC in Monterey, CA in August 1994. A companion paper analyzed the effect on source modules for three specific fuel options, and compared the predicted power output with JPL's latest goals for the Pluto Fast Flyby (PFF) mission. The results showed that a 5-module RTG cannot fully meet JPL's goals with any of the available fuels; and that a 6-module RTG more than meets those goals with Russian fuel, almost meets them with U.S. (Cassini-type) fuel, but still falls far short of meeting them with the depleted fuel from the aged (1982) Galileo spare RTG. The inadequacy of the aged fuel was disappointing,because heat source modules made from it already exist, and their use in PFF could result in substantial cost savings. The present paper describes additional analyses which showed that a six-module RTG with the aged fuel can meet JPL's stipulated power margin with a relatively simple design modification, that a second design modification makes it possible to recover all of the mass and size penalty for going from five to six heat source modules, and that a third modification could raise the EOM power margin to 16%.

  15. Design Modifications for Increasing the BOM and EOM Power Output and Reducing the Size and Mass of RTG for the Pluto Mission

    Energy Technology Data Exchange (ETDEWEB)

    Schock, Alfred; Or, Chuen T; Kumar, Vasanth

    1994-06-01

    A companion paper analyzed the effect on source modules for three specific fuel options, and compared the predicted power output with JPL's latest goals for the Pluto Fast Flyby (PFF) mission. The results showed that a 5-module RTG cannot fully meet JPL's goals with any of the available fuels; and that a 6-module RTG more than meets those goals with Russian fuel, almost meets them with U.S. (Cassini-type) fuel, but still falls far short of meeting them with the depleted fuel from the aged (1982) Galileo spare RTG. The inadequacy of the aged fuel was disappointing,because heat source modules made from it already exist, and their use in PFF could result in substantial cost savings. The present paper describes additional analyses which showed that a six-module RTG with the aged fuel can meet JPL's stipulated power margin with a relatively simple design modification, that a second design modification makes it possible to recover all of the mass and size penalty for going from five to six heat source modules, and that a third modification could raise the EOM power margin to 16%. There are four copies in the file. Cross Reference ESD Files FSC-ESD-217-94-531 (CID #8572)

  16. 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.

  17. Design peculiarities prospects of the use of small-size low power RTG for investigating planets and small bodies of the solar system

    Science.gov (United States)

    Pustovalov, A. A.; Gusev, V. V.; Pankin, M. I.

    1998-01-01

    The paper considers some aspects of the development of the space plutonium-238 radionuclide thermoelectrical generators (RTG) of low power. Such autonomous sources of electrical power can be first be used for electrical supply and heating of the equipment of small stations, penetrators, probes descending on the planets and asteroids, where a low illumination and low temperatures make it difficult to use solar batteries and chemical current sources.

  18. An evaluation of alternate production methods for Pu-238 general purpose heat source pellets

    Energy Technology Data Exchange (ETDEWEB)

    Mark Borland; Steve Frank

    2009-06-01

    For the past half century, the National Aeronautics and Space Administration (NASA) has used Radioisotope Thermoelectric Generators (RTG) to power deep space satellites. Fabricating heat sources for RTGs, specifically General Purpose Heat Sources (GPHSs), has remained essentially unchanged since their development in the 1970s. Meanwhile, 30 years of technological advancements have been made in the applicable fields of chemistry, manufacturing and control systems. This paper evaluates alternative processes that could be used to produce Pu 238 fueled heat sources. Specifically, this paper discusses the production of the plutonium-oxide granules, which are the input stream to the ceramic pressing and sintering processes. Alternate chemical processes are compared to current methods to determine if alternative fabrication processes could reduce the hazards, especially the production of respirable fines, while producing an equivalent GPHS product.

  19. Metabolic Profiling of Retrograde Pathway Transcription Factors Rtg1 and Rtg3 Knockout Yeast

    Directory of Open Access Journals (Sweden)

    Zanariah Hashim

    2014-07-01

    Full Text Available Rtg1 and Rtg3 are two basic helix-loop-helix (bHLH transcription factors found in yeast Saccharomyces cerevisiae that are involved in the regulation of the mitochondrial retrograde (RTG pathway. Under RTG response, anaplerotic synthesis of citrate is activated, consequently maintaining the supply of important precursors necessary for amino acid and nucleotide synthesis. Although the roles of Rtg1 and Rtg3 in TCA and glyoxylate cycles have been extensively reported, the investigation of other metabolic pathways has been lacking. Characteristic dimer formation in bHLH proteins, which allows for combinatorial gene expression, and the link between RTG and other regulatory pathways suggest more complex metabolic signaling involved in Rtg1/Rtg3 regulation. In this study, using a metabolomics approach, we examined metabolic alteration following RTG1 and RTG3 deletion. We found that apart from TCA and glyoxylate cycles, which have been previously reported, polyamine biosynthesis and other amino acid metabolism were significantly altered in RTG-deficient strains. We revealed that metabolic alterations occurred at various metabolic sites and that these changes relate to different growth phases, but the difference can be detected even at the mid-exponential phase, when mitochondrial function is repressed. Moreover, the effect of metabolic rearrangements can be seen through the chronological lifespan (CLS measurement, where we confirmed the role of the RTG pathway in extending the yeast lifespan. Through a comprehensive metabolic profiling, we were able to explore metabolic phenotypes previously unidentified by other means and illustrate the possible correlations of Rtg1 and Rtg3 in different pathways.

  20. 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.

  1. Lunar Surface Stirling Power Systems Using Isotope Heat Sources

    Science.gov (United States)

    Schmitz, Paul C.; Penswick, L. Barry; Shaltens, Richard K.

    2010-01-01

    For many years, NASA has used the decay of plutonium-238 (Pu-238) (in the form of the General Purpose Heat Source (GPHS)) as a heat source for Radioisotope Thermoelectric Generators (RTGs), which have provided electrical power for many NASA missions. While RTGs have an impressive reliability record for the missions in which they have been used, their relatively low thermal to electric conversion efficiency and the scarcity of plutonium-238 (Pu-238) has led NASA to consider other power conversion technologies. NASA is considering returning both robotic and human missions to the lunar surface and, because of the long lunar nights (14.75 Earth days), isotope power systems are an attractive candidate to generate electrical power. NASA is currently developing the Advanced Stirling Radioisotope Generator (ASRG) as a candidate higher efficiency power system that produces greater than 160 W with two GPHS modules at the beginning of life (BOL) (32% efficiency). The ASRG uses the same Pu-238 GPHS modules, which are used in RTG, but by coupling them to a Stirling convertor provides a four-fold reduction in the number of GPHS modules. This study considers the use of americium-241 (Am-241) as a substitute for the Pu-238 in Stirling- convertor-based Radioisotope Power Systems (RPS) for power levels from tens of watts to 5 kWe. The Am-241 is used as a substitute for the Pu-238 in GPHS modules. Depending on power level, different Stirling heat input and removal systems are modeled. It was found that substituting Am-241 GPHS modules into the ASRG reduces power output by about one-fifth while maintaining approximately the same system mass. In order to obtain the nominal 160 W of electrical output of the Pu-238 ASRG requires 10 Am-241 GPHS modules. Higher power systems require changing from conductive coupling heat input and removal from the Stirling convertor to either pumped loops or heat pipes. Liquid metal pumped loops are considered as the primary heat transportation on the hot

  2. Temperature-time distribution and thermal stresses on the RTG fins and shell during water cooling

    Science.gov (United States)

    Turner, R. H.

    1983-01-01

    Radioisotope thermoelectric generator (RTG) packages designed for space missions generally do not require active cooling. However, the heat they generate cannot remain inside of the launch vehicle bay and requires active removal. Therefore, before the Shuttle bay door is closed, the RTG coolant tubes attached to the heat rejection fins must be filled with water, which will circulate and remove most of the heat from the cargo bay. There is concern that charging a system at initial temperature around 200 C with water at 24 C can cause unacceptable thermal stresses in the RTG shell and fins. A computer model is developed to estimate the transient temperature distribution resulting from such charging. The thermal stresses resulting from the temperature gradients do not exceed the elastic deformation limit for the material. Since the simplified mathematical model for thermal stresses tends to overestimate stresses, it is concluded that the RTG can be cooled by introducing water at 24 C to the initially hot fin coolant tubes while the RTG is in the Shuttle cargo bay.

  3. Temperature-time distribution and thermal stresses on the RTG fins and shell during water cooling

    Science.gov (United States)

    Turner, R. H.

    1983-01-01

    Radioisotope thermoelectric generator (RTG) packages designed for space missions generally do not require active cooling. However, the heat they generate cannot remain inside of the launch vehicle bay and requires active removal. Therefore, before the Shuttle bay door is closed, the RTG coolant tubes attached to the heat rejection fins must be filled with water, which will circulate and remove most of the heat from the cargo bay. There is concern that charging a system at initial temperature around 200 C with water at 24 C can cause unacceptable thermal stresses in the RTG shell and fins. A computer model is developed to estimate the transient temperature distribution resulting from such charging. The thermal stresses resulting from the temperature gradients do not exceed the elastic deformation limit for the material. Since the simplified mathematical model for thermal stresses tends to overestimate stresses, it is concluded that the RTG can be cooled by introducing water at 24 C to the initially hot fin coolant tubes while the RTG is in the Shuttle cargo bay.

  4. Multiple source ground heat storage

    Science.gov (United States)

    Belzile, P.; Lamarche, L.; Rousse, D. R.

    2016-09-01

    Sharing geothermal borefields is usually done with each borehole having the same inlet conditions (flow rate, temperature and fluid). The objective of this research is to improve the energy efficiency of shared and hybrid geothermal borefields by segregating heat transfer sources. Two models are briefly presented: The first model allows the segregation of the inlet conditions for each borefields; the second model allows circuits to be defined independently for each leg of double U-tubes in a borehole. An application couples residential heat pumps and arrays of solar collectors. Independent circuits configuration gave the best energy savings in a symmetric configuration, the largest shank spacing and with solar collectors functioning all year long. The boreholes have been shortened from 300 m to 150 m in this configuration.

  5. Heat Transfer Analysis for Optimal Design of Radioisotope Thermoelectric Generator

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jong Han; Son, Kwang Jae; Hong, Jintae; Kim, Jong Bum [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-05-15

    A new approach is need in the space development and requires a technique having a high degree of reliability. For example, there is radioisotope thermoelectric generator(RTG) using radioisotope that has different mechanism in comparison with solar power as power source. This is a technology that has already been trusted by generator for space in the developed countries. For example, RTG is essential for moon explorer because no other power exist source night of moon. In this study, we investigated the thermal efficiency according to the structure of RTG. Specifically, the thermal properties were analyzed according to the presence of the shield inside vacuum heat-insulating part of the RTG through the finite element analysis. Finite element analysis was used to analyze the characteristics of the temperature distribution in the RTG models according to the shield. The structure of the shield came out less heat loss than the structure without shield. As a result, the structure with a shield is advantage in the RTG design.

  6. 30 CFR 57.4500 - Heat sources.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Heat sources. 57.4500 Section 57.4500 Mineral... HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Fire Prevention and Control Installation/construction/maintenance § 57.4500 Heat sources. Heat sources capable of producing...

  7. 30 CFR 56.4500 - Heat sources.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Heat sources. 56.4500 Section 56.4500 Mineral... HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Fire Prevention and Control Installation/construction/maintenance § 56.4500 Heat sources. Heat sources capable of producing...

  8. 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.

  9. 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.

  10. 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...

  11. Advanced radioisotope heat source for Stirling Engines

    Science.gov (United States)

    Dobry, T. J.; Walberg, G.

    2001-02-01

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

  12. 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...

  13. Evaluation of Aqueous and Powder Processing Techniques for Production of Pu-238-Fueled General Purpose Heat Sources

    Energy Technology Data Exchange (ETDEWEB)

    2008-06-01

    This report evaluates alternative processes that could be used to produce Pu-238 fueled General Purpose Heat Sources (GPHS) for radioisotope thermoelectric generators (RTG). Fabricating GPHSs with the current process has remained essentially unchanged since its development in the 1970s. Meanwhile, 30 years of technological advancements have been made in the fields of chemistry, manufacturing, ceramics, and control systems. At the Department of Energy’s request, alternate manufacturing methods were compared to current methods to determine if alternative fabrication processes could reduce the hazards, especially the production of respirable fines, while producing an equivalent GPHS product. An expert committee performed the evaluation with input from four national laboratories experienced in Pu-238 handling.

  14. Earth's Heat Source - The Sun

    CERN Document Server

    Manuel, Oliver K

    2009-01-01

    The Sun encompasses planet Earth, supplies the heat that warms it, and even shakes it. The United Nation Intergovernmental Panel on Climate Change (IPCC) assumed that solar influence on our climate is limited to changes in solar irradiance and adopted the consensus opinion of a Hydrogen-filled Sun, the Standard Solar Model (SSM). They did not consider the alternative solar model and instead adopted another consensus opinion: Anthropogenic greenhouse gases play a dominant role in climate change. The SSM fails to explain the solar wind, solar cycles, and the empirical link of solar surface activity with Earth changing climate. The alternative solar model, that was molded from an embarrassingly large number of unexpected observations revealed by space-age measurements since 1959, explains not only these puzzles but also how closely linked interactions between the Sun and its planets and other celestial bodies induce turbulent cycles of secondary solar characteristics that significantly affect Earth climate.

  15. Characterization and modeling of the heat source

    Energy Technology Data Exchange (ETDEWEB)

    Glickstein, S.S.; Friedman, E.

    1993-10-01

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

  16. Ground as a possible heat pump source

    Energy Technology Data Exchange (ETDEWEB)

    Lazzarin, R. [Padova Univ. (Germany). Dipt. di Tecnica e Gestione die Istemi Industriali

    2001-06-01

    Heat pumps are devices that can increase the thermal level of heat taken from an available source. Their performances are usually very sensible to the temperatures. This is the reason why sources different from the outside air are welcome, since that source is thermally unfavourable. The ground is a possible very favourable source: temperature variations are damped in the ground so much the more deeper one descends. The variations are also delayed, so that in the coldest period one can find equality very good thermal levels. The two main used systems are: horizontal tubes at a depth between 0.8 and 1.5m and vertical tubes. This last technology has gained an increasing popularity with depths which are sometimes deeper than 100m. It interests a large volume of ground with a comparatively small surface area. It is a technology already widespread in Switzerland (where more than 15.000 ground heat pumps were installed in these years), Germany and Austria. It could be a very favourable technology also in Italy and other mediterranean countries both for the presence of good thermal levels underground with excellent characteristics of heat exchange and for the possible use of the ground as a suitable summer thermal sink. (orig.)

  17. MODEL OF LASER-TIG HYBRID WELDING HEAT SOURCE

    Institute of Scientific and Technical Information of China (English)

    Chen Yanbin; Li Liqun; Feng Xiaosong; Fang Junfei

    2004-01-01

    The welding mechanism of laser-TIG hybrid welding process is analyzed. With the variation of arc current, the welding process is divided into two patterns: deep-penetration welding and heat conductive welding. The heat flow model of hybrid welding is presented. As to deep-penetration welding, the heat source includes a surface heat flux and a volume heat flux. The heat source of heat conductive welding is composed of two Gaussian distribute surface heat sources. With this heat source model, a temperature field is calculated. The finite element code MARC is employed for this purpose. The calculation results show a good agreement with the experimental data.

  18. General-Purpose Heat Source development: Safety Verification Test Program. Bullet/fragment test series

    Energy Technology Data Exchange (ETDEWEB)

    George, T.G.; Tate, R.E.; Axler, K.M.

    1985-05-01

    The radioisotope thermoelectric generator (RTG) that will provide power for space missions contains 18 General-Purpose Heat Source (GPHS) modules. Each module contains four /sup 238/PuO/sub 2/-fueled clads and generates 250 W/sub (t)/. Because a launch-pad or post-launch explosion is always possible, we need to determine the ability of GPHS fueled clads within a module to survive fragment impact. The bullet/fragment test series, part of the Safety Verification Test Plan, was designed to provide information on clad response to impact by a compact, high-energy, aluminum-alloy fragment and to establish a threshold value of fragment energy required to breach the iridium cladding. Test results show that a velocity of 555 m/s (1820 ft/s) with an 18-g bullet is at or near the threshold value of fragment velocity that will cause a clad breach. Results also show that an exothermic Ir/Al reaction occurs if aluminum and hot iridium are in contact, a contact that is possible and most damaging to the clad within a narrow velocity range. The observed reactions between the iridium and the aluminum were studied in the laboratory and are reported in the Appendix.

  19. Ion plating with an induction heating source

    Science.gov (United States)

    Spalvins, T.; Brainard, W. A.

    1976-01-01

    Induction heating is introduced as an evaporation heat source in ion plating. A bare induction coil without shielding can be directly used in the glow discharge region with no arcing. The only requirement is to utilize an rf inductive generator with low operating frequency of 75 kHz. Mechanical simplicity of the ion plating apparatus and ease of operation is a great asset for industrial applications; practically any metal such as nickel, iron, and the high temperature refractories can be evaporated and ion plated.

  20. Some comments on air source heat pumps

    Energy Technology Data Exchange (ETDEWEB)

    Haukaas, H.T. (Norges tekniska hoegskola, Trondheim (Norway)). Institutt for kuldeteknikk

    1982-02-01

    Some vital conditions regarding air/water heat pumps are analyzed by use of computer simulators of a middle sized heat pump system. Heat pumps, and specially air source units, should always be used in combination with conventional heating equipment for peak load supply. (Bivalent systems). The economic optimum heat pump capacity compared to system design load is strongly related to the climate. At typical coastal conditions a ratio of 60-70 per cent is found favourable, while 40-50 per cent will be the correct choice for Norwegian inland area. Analysis of the evaporator shows that it should be designed for 120-130 W/m/sup 2/ specific load and 2-2.2 m/s inlet air velocity, which is well below common practice in designing standard air coolers. The condenser LMTD (logaritmic mean temperature difference) should be chosen about 4 degrees C, while the corresponding 'sellers optimum' is calculated to app. 8.5 degrees C. The difference in total heating costs between systems fully designed according to 'sellers optimum' and 'buyers optimum' respectively is found to be about 0.01 Nkr/kWh.

  1. Research on ground heat exchanger of Ground Source Heat Pump technique

    Institute of Scientific and Technical Information of China (English)

    LIU Dong-sheng; SUN You-hong; GAO Ke; WU Xiao-hang

    2004-01-01

    Ground Source Heat Pump technique and its operating principle are described in this paper. Ground heat exchanger is the key technique of ground source heat pump and its pattems are discussed. Software is helpful to design ground heat exchanger. A project of Chinese Ground Source Heat Pump is introduced and its market is more and more extensive.

  2. Cassini RTG Acceptance Test Results and RTG Performance on Galileo and Ulysses

    Science.gov (United States)

    Kelly, C. E.; Klee, P. M.

    1997-06-01

    Flight acceptance testing has been completed for the RTGs to be used on the Cassini spacecraft which is scheduled for an October 6, 1997 launch to Saturn. The acceptance test program includes vibration tests, magnetic field measurements, properties (weight and c.g.) and thermal vacuum test. This paper presents The thermal vacuum test results. Three RTGs are to be used, F 2, F 6, and F 7. F 5 is tile back up RTG, as it was for the Galileo and Ulysses missions launched in 1989 and 1990, respectively. RTG performance measured during the thermal vacuum tests carried out at die Mound Laboratory facility met all specification requirements. Beginning of mission (BOM) and end of mission (EOM) power predictions have been made based on than tests results. BOM power is predicted to be 888 watts compared to the minimum requirement of 826 watts. Degradation models predict the EOM power after 16 years is to be 640 watts compared to a minimum requirement of 596 watts. Results of small scale module tests are also showing. The modules contain couples from the qualification and flight production runs. The tests have exceeded 28,000 hours (3.2 years) and are continuing to provide increased confidence in the predicted long term performance of the Cassini RTGs. All test results indicate that the power requirements of the Cassini spacecraft will be met. BOM and EOM power margins of over five percent are predicted. Power output from telemetry for the two Galileo RTGs are shown from the 1989 launch to the recent Jupiter encounter. Comparisons of predicted, measured and required performance are shown. Telemetry data are also shown for the RTG on the Ulysses spacecraft which completed its planned mission in 1995 and is now in the extended mission.

  3. Cassini RTG acceptance test results and RTG performance on Galileo and Ulysses

    Energy Technology Data Exchange (ETDEWEB)

    Kelly, C.E.; Klee, P.M. [Lockheed Martin Corp., Philadelphia, PA (United States)

    1997-12-31

    Flight acceptance testing has been completed for the RTGs to be used on the Cassini spacecraft which is scheduled for an October 6, 1997 launch to Saturn. The acceptance test program includes vibration tests, magnetic field measurements, mass properties (weight and c.g.) and thermal vacuum test. This paper presents the thermal vacuum test results. Three RTGs are to be used, F-2, F-6, and F-7. F-5 is the backup RTG, as it was for the Galileo and Ulysses missions launched in 1989 and 1990, respectively. RTG performance measured during the thermal vacuum tests carried out at the Mound Laboratory facility met all specification requirements. Beginning of mission (BOM) and end of mission (EOM) power predictions have been made based on these tests results. BOM power is predicted to be 888 watts compared to the minimum requirement of 826 watts. Degradation models predict the EOM power after 16 years is to be 640 watts compared to a minimum requirement of 596 watts. Results of small scale module tests are also shown. The modules contain couples from the qualification and flight production runs. The tests have exceeded 28,000 hours (3.2 years) and are continuing to provide increased confidence in the predicted long term performance of the Cassini RTGs. All test results indicate that the power requirements of the Cassini spacecraft will be met. BOM and EOM power margins of over 5% are predicted. Power output from telemetry for the two Galileo RTGs are shown from the 1989 launch to the recent Jupiter encounter. Comparisons of predicted, measured and required performance are shown. Telemetry data are also shown for the RTG on the Ulysses spacecraft which completed its planned mission in 1995 and is now in the extended mission.

  4. A Sensitivity Study on Radiation Dose of 500W RTPV having Different Source Shapes

    Energy Technology Data Exchange (ETDEWEB)

    Cheon, Seong Jae; Hong, Ser Gi [KAERI, Daejeon (Korea, Republic of)

    2016-05-15

    Radioisotope Thermoelectric Generators (RTG) has been considered as a power supply system for long-lived operation in space. RTG is an essentially nuclear battery that converts the heat resulted from the radioactive decay into electricity. RTG has the advantage of high energy density and long life operation because of the very long half-life of the radioisotopes. However, RTG systems have relatively low thermoelectric energy conversion efficiency of 3-7%. In this work, a sensitivity study on the total radiation dose was performed for 500W RTPVs having different source configurations. In particular, comparative shielding analysis using two different types of source design (a cubic source type and cylindrical sources type) were performed to show their relative performances. The results show that the RTPV(the cubic homogeneous source type and the cylindrical heterogeneous source type) device using the cylindrical sources type has lower dose values by 6-11% depending on the packing factor at the measurement cell than the RTPV device using the cubic source type. Also, we investigated the effect of the compactness of four cylindrical sources on the radiation dose. The results showed that the loosely packed sources give lower total radiation dose than the closely packed sources.

  5. Microflares as Possible Sources for Coronal Heating

    Indian Academy of Sciences (India)

    Meera Gupta; Rajmal Jain; Jayshree Trivedi; A. P. Mishra

    2008-03-01

    We present a preliminary study of 27 microflares observed by Solar X-ray Spectrometer (SOXS) mission during July 2003 to August 2006. We found that all 27 microflares show the Fe-line feature peaking around 6.7 keV, which is an indicator of the presence of coronal plasma temperature ≥ 9 MK. On the other hand, the spectra of microflares showhybrid model of thermal and non-thermal emission, which further supports them as possible sources of coronal heating. Our results based on the analysis show that the energy relapsed by the microflares is good enough for heating of the active corona. We discuss our results in the light of the hybrid model of microflares production.

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

    DEFF Research Database (Denmark)

    Haglind, Fredrik; Elmegaard, Brian

    2014-01-01

    Low-temperature heat sources are available in many applications, ranging from waste heat from marine diesel engines, industries and refrigeration plants to biomass, geothermal and solar heat sources. There is a great potential for enhancing the utilization of these heat sources by novel thermodyn......Low-temperature heat sources are available in many applications, ranging from waste heat from marine diesel engines, industries and refrigeration plants to biomass, geothermal and solar heat sources. There is a great potential for enhancing the utilization of these heat sources by novel.......Both power production and heat pumps may benefit from the development as both technologies utilize a heat source. This makes it possible to cover the complete temperature range of low temperature sources. The development may contribute to significantly lower energy consumption in Danish industry and shipping...

  7. Reflection of ground-source heat pump systems' application

    Institute of Scientific and Technical Information of China (English)

    ZHANGSuyun; LINZhenguo; WUXiangsheng; WUTian

    2003-01-01

    Ground-source heat pump system is an air-conditioning form of energy efficient and environment protection. This article introduced the forms of ground-source heat pump systems, analyzed the problems of ground-source heat pump systems in application in China, and put forward the solutions to these problems.

  8. Optimal Ground Source Heat Pump System Design

    Energy Technology Data Exchange (ETDEWEB)

    Ozbek, Metin [ENVIRON; Yavuzturk, Cy [University of Hartford; Pinder, George [University of Vermont

    2015-04-15

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

  9. Optimal Ground Source Heat Pump System Design

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-04-01

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

  10. 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.

  11. Desalination using low grade heat sources

    Science.gov (United States)

    Gude, Veera Gnaneswar

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

  12. AN INVESTIGATION OF THERMAL CHARACTERISTICS OF A SINTERED-WICK HEAT PIPE WITH DOUBLE HEAT SOURCES

    Directory of Open Access Journals (Sweden)

    Nattawut Tharawadee

    2013-01-01

    Full Text Available Heat pipes have been used extensively in the electronic industry for decades especially in laptop computers. For cost-effectiveness, a single heat pipe is designed to simultaneously transfer heat from both the Central Processing Unit (CPU and the Graphics Processing Unit (GPU inside the main board to the heat sink. This causes the efficiency of the heat pipe to change without any theoretical prediction. In this research, thermal performance of a sintered-wick heat pipe with double heat sources has been experimentally and numerically investigated by utilizing the Finite Element Method (FEM. The focus being the effect that the distance between the two heat sources and also the power input pattern (heat source#1 (HT1: heat source#2(HT2 has on temperature and thermal resistance of the heat pipe. The first heat source (HT1 was located at one end and the heat sink was located at another end of the heat pipe, while another heat source (HT2 was placed between HT1 and a heat sink. The ratios of heat input power were controlled at 10W:10W, 20W:10W and 30W:10W. Two copper blocks (15 mm×15 mm were used as heat sources for the evaporator section (Le1, Le2 to electrically supply heat to the bottom half of the heat pipe. A mathematical model using the Finite Element Method (FEM was established to calculate temperature and thermal resistance. The speed of the cooling fan was adjusted to maintain constant operating temperature at the adiabatic section throughout the tests. The operating temperature was controlled at 60 ± 3°C. It was noted that, when distance between the heat sources was increased from 0 mm to 75 mm, thermal resistance slightly decreased from 0.589-0.53°C/W respectively. Heat source 2, therefore, should be placed as close as possible to the condenser section. Both heat sources should have a distance between them of at least 12 mm, which minimizes heat accumulation. When the power input of HT1 was increased from 10 W to 30W (HT2 was

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

    Science.gov (United States)

    Pei, Guihong; Zhang, Liyin

    2016-01-01

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

  14. Heating a chemical current source which operates at low temperature

    Energy Technology Data Exchange (ETDEWEB)

    Mitsumata, T.; Khosikhara, N.

    1983-02-14

    A chamber for catalytic ignition of hydrogen or gasoline is installed in a chemical current source. The isolated heat heats the chemical current source with a low temperature of the environment providing its optimal operational conditions. The fuel is fed into the chamber from a tank or chamber located in the body of the chemical current source.

  15. Irregular spacing of heat sources for treating hydrocarbon containing formations

    Science.gov (United States)

    Miller, David Scott [Katy, TX; Uwechue, Uzo Philip [Houston, TX

    2012-06-12

    A method for treating a hydrocarbon containing formation includes providing heat input to a first section of the formation from one or more heat sources located in the first section. Fluids are produced from the first section through a production well located at or near the center of the first section. The heat sources are configured such that the average heat input per volume of formation in the first section increases with distance from the production well.

  16. Performance analysis of air——water dual source heat pump water heater with heat recovery

    Institute of Scientific and Technical Information of China (English)

    CHEN ZeShao; TAO WenQuan; ZHU YanWen; HU Peng

    2012-01-01

    A new air-water dual source heat pump water heater with heat recovery is proposed.The heat pump system can heat water by using a single air source,a single water source,or air-water dual sources.The water is first pre-heated by waste hot water,then heated by the heat pump.Waste heat is recovered by first preheating the cold water and as water source of the heat pump.According to the correlated formulas of the coefficient of performance of air-source heat pump and water-source heat pump,and the gain coefficient of heat recovery-preheater,the formulas for the coefficient of performance of heat pump in six operating modes are obtained by using the dimensionless correspondence analysis method.The system characteristics of heat absorption and release associated with the heat recovery-preheater are analyzed at different working conditions.The developed approaches can provide reference for the optimization of the operating modes and parameters.The results of analysis and experiments show that the coefficient of performance of the device can reach 4-5.5 in winter,twice as much as air source heat pump water heater.The utilization of waste heat in the proposed system is higher than that in the system which only uses waste water to preheating or as heat source.Thus,the effect of energy saving of the new system is obvious.On the other hand,the dimensionless correspondence analysis method is introduced to performance analysis of the heat pump,which also has theoretical significance and practical value.

  17. Modular Radioisotope Thermoelectric Generator (RTG) Program. Final technical report

    Energy Technology Data Exchange (ETDEWEB)

    1992-12-31

    Section 2.0 of this report summarizes the MOD-RTG reference flight design, and Section 3.0 discusses the Ground Demonstration System design. Multicouple technology development is discussed in Section 4.0, and Section 5.0 lists all published technical papers prepared during the course of the contract.

  18. Ground-source Heat Pump Barometer

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2011-09-15

    The double whammy dealt by the economic crisis and housing slump has stifled expansion of the ground-source heat pump market in many European countries. The European Union market contracted for the second year running (by 2.9% between 2009 and 2010), and this despite the fact that more than 100,000 units were sold over the twelve-month period, taking the number of installed units past the one million mark. [French] La crise economique ainsi que la crise immobiliere qui touchent de nombreux pays europeens ne facilitent pas l'essor du marche de la pompe a chaleur geothermique. Pour la deuxieme annee consecutive, le marche de l'union europeenne est en baisse (-2,9 % entre 2009 et 2010). il parvient tout de meme a se maintenir au-dessus des 100 000 unites vendues par an, ce qui lui permet de depasser pour la premiere fois le cap du million d'unites installees.

  19. Mapping of low temperature heat sources in Denmark

    DEFF Research Database (Denmark)

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

    2015-01-01

    of those heat sources feasible. In this work a mapping of those heat sources is performed to gain an overview of the potential amount of waste heat and natural heat sources in Denmark. The energy potentials are mapped together with the temperature ranges at which the heat is available and the exergy...... content of the heat. The mapping is based on data and literature primarily published by Statistics Denmark and the Danish Energy Agency, as well as interviews with specialists and engineering estimates. The results indicate that up to 13 % of the energy input to the analysed sectors is available as waste...... and deep geothermal energy. The theoretical solar thermal potential alone would be above 500 PJ per year. For the development of advanced thermodynamic cycles for the integration of heat sources in the Danish energy system, several areas of interest are determined. In the maritime transport sector a high...

  20. Depth Determination of an Abnormal Heat Source in Biological Tissues

    Institute of Scientific and Technical Information of China (English)

    WANG Qing-Hua; LI Zhen-Hua; LAI Jian-Cheng; HE An-Zhi

    2011-01-01

    We deduce the surface temperature distribution generated by the inner point heat source in biological tissues and propose a graphic method to retrieve the depth of the point heat source. The practical surface temperature distribution can be regarded as the convolution of the temperature distribution of the inner point heat source with the heat source shape function. The depth of an abnormal heat source in biological tissues can be retrieved by using the graphic method combined with the blind deconvolution scheme.%We deduce the surface temperature distribution generated by the inner point heat source in biological tissues and propose a graphic method to retrieve the depth of the point heat source.The practical surface temperature distribution can be regarded as the convolution of the temperature distribution of the inner point heat source with the heat source shape function.The depth of an abnormal heat source in biological tissues can be retrieved by using the graphic method combined with the blind deconvolution scheme.Surface temperature distribution of the biological tissues is closely related to the neighboring metabolic heat production,blood circulation in an organism and environmental temperature.[1] The abnormal metabolic performances of a local region in biological tissue imply malignant changes occurring,which can be distinguished from the variance of surface temperature.Modern development of thermal infrared (TIR) imaging has made the surface temperature measurement of biological tissue easier.Nowadays,several types of tumors,e.g.skin or breast can be recognized with TIR imaging.[2] The diagnostics with TIR imaging require more experienced operators and can not accurately ascertain the site of pathological changes,which limits the value of this technology.Therefore ascertaining the depth of inner heat source in biological body has the extremely important clinical value.

  1. Similarity of Heat Transfer on Heat Source Elements in the Entrance Region in Electronic Equipment

    Institute of Scientific and Technical Information of China (English)

    Jane Z. Jiang; Sui Lin

    2001-01-01

    A similarity equation for heat transfer on heat source elements situated in the entrance region in electronic equipment is developed based on the experimental data obtained by Sparrow et al.[4]. The characteristic of the similarity equation is that the ratio of the heat transfer coefficient at the entrance region to that at the fully developed region is independent of the Reynolds number. It depends only on the row number of the elements situated in the entrance region. An example of the usefulness of the similarity equation is presented that determines the heat transfer on heat source elements in a power unit that contains only a small number of the heat source elements.

  2. The mechanical measuring method of welding heat source efficiency

    Institute of Scientific and Technical Information of China (English)

    Zhang Jianqiang; Zhang Guodong; He Jie; Wang Chengquan; Chen Bingquan

    2007-01-01

    Based on the principle of residual deformation induced by superposition of the welding residual stress and working stress, the welding heat source efficiency has been determined by measuring displacement changes of specimens under loading and unloading in tensile tests, and combining with calculating welding parameters. Meanwhile, the welding heat source efficiencies obtained are compared with those of the measuring-calculating method. The research results show that the welding heat source efficiencies are almost the same as those obtained by the measuring-calculating method. Therefore, the welding heat source efficiency can be determined accurately by this method, and a new determining method of the heat source efficiency for the welding heat process calculating has been provided.

  3. A novel design method for ground source heat pump

    Directory of Open Access Journals (Sweden)

    Dong Xing-Jie

    2014-01-01

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

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

    Directory of Open Access Journals (Sweden)

    W. Piekarska

    2010-10-01

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

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

    Institute of Scientific and Technical Information of China (English)

    曲世林; 马飞; 仇安兵

    2009-01-01

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

  6. Heat sources in proton exchange membrane (PEM) fuel cells

    Science.gov (United States)

    Ramousse, Julien; Lottin, Olivier; Didierjean, Sophie; Maillet, Denis

    In order to model accurately heat transfer in PEM fuel cell, a particular attention had to be paid to the assessment of heat sources in the cell. Although the total amount of heat released is easily computed from its voltage, local heat sources quantification and localization are not simple. This paper is thus a discussion about heat sources/sinks distribution in a single cell, for which many bold assumptions are encountered in the literature. The heat sources or sinks under consideration are: (1) half-reactions entropy, (2) electrochemical activation, (3) water sorption/desorption at the GDL/membrane interfaces, (4) Joule effect in the membrane and (5) water phase change in the GDL. A detailed thermodynamic study leads to the conclusion that the anodic half-reaction is exothermic (Δ Sr ev a = - 226 J mo l-1 K-1) , instead of being athermic as supposed in most of the thermal studies. As a consequence, the cathodic half-reaction is endothermic (Δ Sr ev c = + 62.8 J mo l-1 K-1) , which results in a heat sink at the cathode side, proportional to the current. In the same way, depending on the water flux through the membrane, sorption can create a large heat sink at one electrode and an equivalent heat source at the other. Water phase change in the GDL - condensation/evaporation - results in heat sources/sinks that should also be taken into account. All these issues are addressed in order to properly set the basis of heat transfer modeling in the cell.

  7. GPHS-RTGs in support of the Cassini RTG Program. Final technical report, January 11, 1991--April 30, 1998

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-08-01

    As noted in the historical summary, this program encountered a number of changes in direction, schedule, and scope over the period 11 January 1991 to 31 December 1998. The report provides a comprehensive summary of all the varied aspects of the program over its seven and a quarter years, and highlights those aspects that provide information beneficial to future radioisotope programs. In addition to summarizing the scope of the Cassini GPHS-RTG Program provided as background, the introduction includes a discussion of the scope of the final report and offers reference sources for information on those topics not covered. Much of the design heritage of the GPHS-RTG comes from the Multi-Hundred Watt (MHW) RTGs used on the Lincoln Experimental Satellites (LES) 8/9 and Voyager spacecraft. The design utilized for the Cassini program was developed, in large part, under the GPHS-RTG program which produced the Galileo and Ulysses RTGs. Reports from those programs included detailed documentation of the design, development, and testing of converter components and full converters that were identical to, or similar to, components used in the Cassini program. Where such information is available in previous reports, it is not repeated here.

  8. GPHS RTGs in Support of the Cassini RTG Program. Final Technical Report, January 11, 1991 - April 30, 1998

    Science.gov (United States)

    1998-08-01

    As noted in the historical summary, this program encountered a number of changes in direction, schedule, and scope over the period 11 January 1991 to 31 December 1998. The report provides a comprehensive summary of all the varied aspects of the program over its seven and a quarter years, and highlights those aspects that provide information beneficial to future radioisotope programs. In addition to summarizing the scope of the Cassini GPHS RTG Program provided as background, the introduction includes a discussion of the scope of the final report and offers reference sources for information on those topics not covered. Much of the design heritage of the GPHS RTG comes from the Multi Hundred Watt (MHW) RTGs used on the Lincoln Experimental Satellites (LES) 8/9 and Voyager spacecraft. The design utilized for the Cassini program was developed, in large part, under the GPHS RTG program which produced the Galileo and Ulysses RTGs. Reports from those programs included detailed documentation of the design, development, and testing of converter components and full converters that were identical to, or similar to, components used in the Cassini program.

  9. On the solution of heat conduction problems involving heat sources via boundary-fitted grids

    Science.gov (United States)

    Grandi, G. M.; Ferreri, J. C.

    1989-01-01

    It is shown that codes employing boundary-fitted grids (BFG) in heat conduction problems involving heat sources must be implemented in strictly numerically conservative form if accurate results are to be obtained. It is demonstrated that, for one-dimensional problems, nonconservative form imply errors originated in grid nonuniformity that cause a spurious increase in the heat source. This in turn leads to significant errors in the computed solution. Therefore, the implementation of BFG codes using nonconservative forms should be avoided. An application to an unsteady, axisymmetric benchmark problem involving a spherical, time-decaying heat source is presented.

  10. Air Source Cold Climate Heat Pump

    Science.gov (United States)

    2013-08-01

    Unico, Inc. received ISO 9001 :2008 certification. 7.1 COST MODEL The market for CCHP consists includes both residential and light commercial...by electricity that could come from renewable energy. The field demonstration was conducted at the Camp Atterbury Joint Maneuver Training Center...American Society of Heating, Refrigeration, and Air Conditioning Engineers CAJMTC Camp Atterbury Joint Maneuver Training Center CCHP Cold Climate

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

    Directory of Open Access Journals (Sweden)

    Alexandros Sotirios Anifantis

    2016-09-01

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

  12. Heating performance of a ground source heat pump system installed in a school building

    Institute of Scientific and Technical Information of China (English)

    Jaedo; SONG; Kwangho; LEE; Youngman; JEONG; Seongir; CHEONG; Jaekeun; LEE; Yujin; HWANG; Yeongho; LEE; Donghyuk; LEE

    2010-01-01

    The heating performance of a water-to-refrigerant type ground source heat pump system is represented in this paper under the actual working conditions of the GSHP(ground source heat pump) system during the winter season of 2008.Ten heat pump equipments with the capacity of 10 HP each and a closed vertical typed-ground heat exchanger with 24 boreholes of 175 m in depth were constructed.We investigated a variety of working conditions,including the outdoor temperature,the ground temperature,and the water temperature of inlet and outlet of the ground heat exchanger in order to examine the heating performance of the GSHP system.Subsequently,the heating capacity and the input power were investigated to determine the heating performance of the GSHP system.The average heating coefficient of performance(COP) of the heat pump was noted to be 5.1 at partial load of 47%,while the overall system COP was found to be 4.2.Also,performance of the GSHP system was compared with that of air source heat pump.

  13. Oceanic heat sources to Pine Island Bay

    Science.gov (United States)

    Mazloff, M. R.; Gilroy, A. R.; Gille, S. T.; Subramanian, A. C.

    2012-12-01

    The rapid melting of Pine Island Glacier, West Antarctica has been attributed to increased basal melting of its grounded ice-shelf. Recent work suggests that an increased ocean heat supply to Pine Island Bay (PIB) is responsible for this increased melting. There is no consensus, however, on the origin of this increased ocean heat. We use a 2008-2010 state estimate of the Southern Ocean to diagnose the heat budget on the PIB continental shelf. In times of minimal sea-ice coverage, air-sea fluxes dominate the budget. Sea-ice is present over much of the year, however, and on average advection and parameterized small-scale mixing are equally important. The average air-sea fluxes and small scale mixing both act to cool the continental shelf waters, while advection by the large-scale circulation tends to warm these waters. The warmest waters are found on the eastern PIB continental shelf where bathymetric features cause increased advective fluxes and mixing. The average circulation along the PIB continental shelf is eastward consisting of approximately 1 Sv along shelf flow augmented by 1 Sv of across shelf flow to be balanced by a 2 Sv outflow along the eastern PIB shelf. Numerical simulations of passive tracer releases reveal the advective pathways of these waters that reach the continental shelf.

  14. Optimal Hierarchical Decision-Making for Heat Source Selection of District Heating Systems

    Directory of Open Access Journals (Sweden)

    Fang Fang

    2014-01-01

    Full Text Available With the rapid development of China’s urbanization, the proportion between the heating consumption and the energy consumption of the whole society keeps rising in recent years. For a district heating system, the selection of the heat source makes significant impact on the energy efficiency and the pollutant emissions. By integrating the methods of the Analytic Hierarchy Process (AHP and the Preference Ranking Organization Method for Enrichment Evaluation (PROMETHEE, a multiple-attribute decision-making scheme for the heat source selection of district heating systems is proposed in this paper. As a core part of this scheme, a comprehensive benefit index with hierarchical parallel structure is constructed. The economic benefit, environment benefit, and technical benefit can be reflected with a certain percentage in the comprehensive benefit index. To test the efficiency of the proposed scheme, a case study for a large-scale district heating system in Beijing is carried out, where five kinds of heat sources (water source heat pump, ground source heat pump, gas-fired boiler, coal-fired boiler, and oil-fired boiler are taken into account. The analysis and instructions for the final sorting result are also demonstrated.

  15. Development and Use of the Galileo and Ulysses Power Sources

    Energy Technology Data Exchange (ETDEWEB)

    Bennett, Gary L; Hemler, Richard J; Schock, Alfred

    1994-10-01

    Paper presented at the 45th Congress of the International Astronautical Federation, October 1994. The Galileo mission to Jupiter and the Ulysses mission to explore the polar regions of the Sun required a new power source: the general-purpose heat source radioisotope thermoelectric generator (GPHS-RTG), the most powerful RTG yet flow. Four flight-qualified GPHS-RTGs were fabricated with one that is being used on Ulysses, two that are being used on Galileo and one that was a common spare (and is now available for the Cassini mission to Saturn). In addition, and Engineering Unit and a Qualification Unit were fabricated to qualify the design for space through rigorous ground tests. This paper summarizes the ground testing and performance predictions showing that the GPHS-RTGs have met and will continue to meet or exceed the performance requirements of the ongoing Galileo and Ulysses missions. There are two copies in the file.

  16. Heat pump contracting: a source of heat that takes care of the climate; Klimaschonende Waermeversorgung

    Energy Technology Data Exchange (ETDEWEB)

    Beyeler, F.

    2003-07-01

    This article discusses heat pump 'contracting solutions' used in the refurbishment of the central heating systems of two housing developments in Zurich and Thun, Switzerland. In these and other projects, the high level of investment needed for the installation of the heat pumps was met by third-party contractors, who install and operate the space heating and domestic hot water systems and sell the heat energy to the tenants. The system serving the 96 'Rietlihof' apartments in Zurich is operated by the public utilities of the City of Zurich, EWZ, the housing development in Thun by the Bernese power utility BKW. The article stresses the importance of professional planning and the correct choice of heat sources. The ecological and economical advantages of heating system refurbishment projects that use heat pumps built, financed and operated by contractors are discussed.

  17. Cosmological constraints on the graviton mass in RTG

    Science.gov (United States)

    Chugreev, Yu. V.

    2017-07-01

    The Friedmann cosmological scenario in RTG (without inflation) is considered. The joint maximum-likelihood analysis of data on type Ia supernovae, the shift parameter of microwave radiation, and baryon acoustic oscillations from the Sloan catalogue of red galaxies provided tight fit constraints on the graviton mass and the space curvature in GR. It is demonstrated that the confidence interval for the graviton mass extends indefinitely if the quintessence parameter tends to zero. These conclusions are valid if the present scale factor a 0 >(2)-1/6= 0.89. At a 0 type) in the gravitational field equations in a broad range of redshifts (0 < z < 1015).

  18. RTG resource book for western states and provinces: Final proceedings

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1994-12-31

    The Western Interstate Energy Board held a workshop and liaison activities among western states, provinces, and utilities on the formation of Regional Transmission Groups (RTGs). Purpose of the activities was to examine the policy implications for western states and provinces in the formation of RTGs in the West, the implications for western ratepayers and utilities of the RTG formation and potential impacts of RTGs on the western electricity system. The workshop contributed to fulfilling the transmission access and competition objectives of Title VII of the Energy Policy Act of 1992.

  19. Mini-Brayton economic RTG study. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1974-01-01

    The objective of this study is to demonstrate the applicability of a radioisotope heated Mini-Brayton power system to the 1973 USAF/AEC requirements established for the SURVSATCOM Mission. The principal requiremenets of the power system, are: 400 We power level; maximum weight 205 lbs.; $1.2 to 2.0 million per unit cost; and 5y mission duration. A radioisotope heat source that meets the ACE Nuclear Safety Criteria is presented. The major aspects of the Reference Design MB-ERTG are summarized. The Reference Design, utilizes a flexible Brayton rotating unit (BRU), a /sup 244/Cm heat source with ceramic clad fuel cylinders and an aluminum radiator. The flexible BRU has a variable power output capability, from 400 We to 3000 We, and is an important factor in the formulation of a cost effective development plan. The system weight is 186 lb and unit cost, including the /sup 244/Cm fuel, acceptance testing and delivery is $748,000. The total development cost for the 5-yr program is estimated at $16.4M with an additional $6.5M required for /sup 244/Cm heat source development support, /sup 244/Cm fuel, heat source fabrication and capital equipment expenditures. (LCL)

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

    Directory of Open Access Journals (Sweden)

    Čenejac Aleksandra R.

    2012-01-01

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

  1. Helium release from radioisotope heat sources

    Energy Technology Data Exchange (ETDEWEB)

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

    1984-05-01

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

  2. Ground Source Geothermal District Heating and Cooling System

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-10-21

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

  3. Infant respiratory symptoms associated with indoor heating sources.

    Science.gov (United States)

    Triche, Elizabeth W; Belanger, Kathleen; Beckett, William; Bracken, Michael B; Holford, Theodore R; Gent, Janneane; Jankun, Thomas; McSharry, Jean-Ellen; Leaderer, Brian P

    2002-10-15

    This study examined the effects of indoor heating sources on infant respiratory symptoms during the heating season of the first year of life. Mothers delivering babies between 1993 and 1996 at 12 hospitals in Connecticut and Virginia were enrolled. Daily symptom and heating source use information about their infant was obtained every 2 weeks during the first year of life. Heating sources included fireplace, wood stove, kerosene heater, and gas space heater use. Four health outcomes were analyzed by reporting period: days of wheeze, episodes of wheeze, days of cough, and episodes of cough. A large percentage of infants had at least one episode of cough (88%) and wheeze (33%) during the heating season of the first year of life. Wood stove, fireplace, kerosene heater, and gas space heater use was intermittent across the study period. In adjusted Poisson regression models controlling for important confounders, gas space heater use was associated with episodes and days of wheeze. Wood stove use was associated with total days of cough, and kerosene heater use was associated with episodes of cough. Fireplace use was not associated with any of the respiratory symptoms. Use of some heating sources appears related to respiratory symptoms in infants.

  4. 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.

  5. Feasibility of drying system using waste heat as the heating source

    Science.gov (United States)

    Xie, M. N.; Shi, Y. L.; Chen, L. X.

    2016-08-01

    In this study, a wastewater heat pump system was proposed and its thermal performance was analyzed. The proposed system includes two evaporators: an air-source evaporator and a water-source evaporator. The air-source evaporator absorbs heat from the moist hot air which exhaust from the drying oven. The water-source evaporator absorbs heat from the waste water, while the waste water recovers heat from the mechanical energy, which was produced by cutting and polishing in stone production. The thermodynamic model was developed to evaluate the performance of the proposed system. The energetic analysis was carried out to investigate the influences of the temperature of fresh air. The results show significantly higher energy efficiency, compact-sized and energy-saving compared with the system which uses air as the heat source. Among the seven of alternative refrigerants (R152a, R123, R1234yf, R1234ze, R600a, R22 and R600) investigated, R123 was suggested to be used in this heat pump for its high heating efficiency, inflammable, very low ODP(Ozone Depletion Potential) and GWP(Global warming potential).

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-03-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1985-06-01

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

  8. MELCOR Sensitivity Analysis Focusing on the Heat Source

    Energy Technology Data Exchange (ETDEWEB)

    Maeng, Yunhwan; Sung, Joonyoung; Lee, Jaeyoung [Handong Global Univ., Pohang (Korea, Republic of)

    2015-10-15

    Present study conducted MELCOR code calculation by assuming the situation of complete loss of coolant accident (LOCA) scenario in a PWR 17 x 17 single spent fuel assembly, not an overall spent fuel pool. Present study conducted MELCOR analysis focusing on the heat source (decay heat, oxidation heat) and analysis object was PWR 17x17 spent nuclear fuel assembly. By changing the decay heat and oxidation coefficient, variation of peak cladding temperature to the time of the fuel assembly was analyzed. Different oxidation coefficient results the difference on the initiating time and existence of zirconium fire. From the result of MELCOR analysis, we found the criteria of decay heat that MELCOR simulation result showed the disagreement of peak cladding temperature, about 5.0 kW - 10.0 kW range.

  9. Stability of thermal structures with an internal heating source

    CERN Document Server

    Sanchez, Nestor

    2008-01-01

    We study the thermal equilibrium and stability of isobaric, spherical structures having a radiation source located at its center. The thermal conduction coefficient, external heating and cooling rates are represented as power laws of the temperature. The internal heating decreases with distance from the source r approximately as exp(-tau)/(r**2), being tau the optical depth. We find that the influence of the radiation source is important only in the central region, but its effect is enough to make the system thermally unstable above a certain threshold central temperature. This threshold temperature decreases as the internal heating efficiency increases, but, otherwise, it does not depend on the structure size. Our results suggest that a solar-like star migrating into a diffuse interstellar region may destabilize the surrounding medium.

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

    Science.gov (United States)

    Chairani; Sulistyo, S.; Widyawan

    2017-05-01

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

  11. TEM Pump With External Heat Source And Sink

    Science.gov (United States)

    Nesmith, Bill J.

    1991-01-01

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

  12. NUMERICAL STUDY OF TRANSIENT THREE-DIMENSIONAL HEAT CONDUCTION PROBLEM WITH A MOVING HEAT SOURCE

    Directory of Open Access Journals (Sweden)

    Marko V Miloš

    2011-01-01

    Full Text Available A numerical study of transient three-dimensional heat conduction problem with a moving source is presented. For numerical solution Douglas-Gunn alternating direction implicit method is applied and for the moving heat source flux distribution Gaussian function is used. An influence on numerical solution of input parameters figuring in flux boundary conditions is examined. This include parameters appearing in Gaussian function and heat transfer coefficient from free convection boundaries. Sensitivity of cooling time from 800 to 500 °C with respect to input parameters is also tested.

  13. Advanced radioisotope power source options for Pluto Express

    Energy Technology Data Exchange (ETDEWEB)

    Underwood, M.L. [California Inst. of Technology, Pasadena, CA (United States). Jet Propulsion Lab.

    1995-12-31

    In the drive to reduce mass and cost, Pluto Express is investigating using an advanced power conversion technology in a small Radioisotope Power Source (RPS) to deliver the required mission power of 74 W(electric) at end of mission. Until this year the baseline power source under consideration has been a Radioisotope Thermoelectric Generator (RTG). This RTG would be a scaled down GPHS RTG with an inventory of 6 General Purpose Heat Sources (GPHS) and a mass of 17.8 kg. High efficiency, advanced technology conversion options are being examined to lower the power source mass and to reduce the amount of radioisotope needed. Three technologies are being considered as the advanced converter technology: the Alkali Metal Thermal-to-Electric Converter (AMTEC), Thermophotovoltaic (TPV) converters, and Stirling Engines. Conceptual designs for each of these options have been prepared. Each converter would require only 2 GPHSs to provide the mission power and would have a mass of 6.1, 7.2, and 12.4 kg for AMTEC, TPV, and Stirling Engines respectively. This paper reviews the status of each technology and the projected performance of an advanced RPS based on each technology. Based on the projected performance and spacecraft integration issues, Pluto Express would prefer to use the AMTEC based RPS. However, in addition to technical performance, selection of a power technology will be based on many other factors.

  14. Laser induced heat source distribution in bio-tissues

    Science.gov (United States)

    Li, Xiaoxia; Fan, Shifu; Zhao, Youquan

    2006-09-01

    During numerical simulation of laser and tissue thermal interaction, the light fluence rate distribution should be formularized and constituted to the source term in the heat transfer equation. Usually the solution of light irradiative transport equation is given in extreme conditions such as full absorption (Lambert-Beer Law), full scattering (Lubelka-Munk theory), most scattering (Diffusion Approximation) et al. But in specific conditions, these solutions will induce different errors. The usually used Monte Carlo simulation (MCS) is more universal and exact but has difficulty to deal with dynamic parameter and fast simulation. Its area partition pattern has limits when applying FEM (finite element method) to solve the bio-heat transfer partial differential coefficient equation. Laser heat source plots of above methods showed much difference with MCS. In order to solve this problem, through analyzing different optical actions such as reflection, scattering and absorption on the laser induced heat generation in bio-tissue, a new attempt was made out which combined the modified beam broaden model and the diffusion approximation model. First the scattering coefficient was replaced by reduced scattering coefficient in the beam broaden model, which is more reasonable when scattering was treated as anisotropic scattering. Secondly the attenuation coefficient was replaced by effective attenuation coefficient in scattering dominating turbid bio-tissue. The computation results of the modified method were compared with Monte Carlo simulation and showed the model provided reasonable predictions of heat source term distribution than past methods. Such a research is useful for explaining the physical characteristics of heat source in the heat transfer equation, establishing effective photo-thermal model, and providing theory contrast for related laser medicine experiments.

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

    DEFF Research Database (Denmark)

    Schmidt, Henrik Nikolaj Blich; Hattel, Jesper

    2004-01-01

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

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

    DEFF Research Database (Denmark)

    Schmidt, Henrik Nikolaj Blich; Hattel, Jesper

    2004-01-01

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

  17. On an Analog Controlled Precision Heat Power Source

    Science.gov (United States)

    Seilmayer, M.; Katepally, V. K.

    2017-07-01

    The analog controlled precision heat power source is the main part of a sensor development to estimate real time properties of the primary coolant in a 300 kW process cooling system. The measurement of physical properties like thermal conductivity or thermal diffusion requires a precise and accurate heater. The constant heat flux is then applied to the liquid under test to acquire its different properties. Here, commonly established control methods of heating with constant current or constant voltage may fail because the heating resistor changes its resistance with temperature. The idea is to utilize a power monitor circuit like the LT2940, which contains an analog multiplier with a control loop around it. The initial design and its assumed uncertainties will be discussed. The first version of the power controller shows an outstanding performance in terms of precision in a steady state. Compared to conventional switching mode power sources the approach with an analog controlled heater avoids EMI issues as well. The main goal of the present design is a precise source of heat power with less than 0.5% of error.

  18. Multicharged iron ions produced by using induction heating vapor source.

    Science.gov (United States)

    Kato, Yushi; Kubo, Takashi; Muramatsu, Masayuki; Tanaka, Kiyokatsu; Kitagawa, Atsushi; Yoshida, Yoshikazu; Asaji, Toyohisa; Sato, Fuminobu; Iida, Toshiyuki

    2008-02-01

    Multiply charged Fe ions are produced from solid pure material in an electron cyclotron resonance (ECR) ion source. We develop an evaporator by using induction heating with an induction coil which is made of bare molybdenum wire partially covered by ceramic beads in vacuum and surrounding and heating directly the pure Fe rod. Heated material has no contact with insulators, so that outgas is minimized. The evaporator is installed around the mirror end plate outside of the ECR plasma with its hole grazing the ECR zone. Helium or argon gas is usually chosen for supporting gas. The multicharged Fe ions up to Fe(13+) are extracted from the opposite side of mirror and against the evaporator, and then multicharged Fe ion beam is formed. We compare production of multicharged iron ions by using this new source with our previous methods.

  19. A reference heat source for solar collector thermal testing

    Science.gov (United States)

    Harrison, S. J.; Bernier, M. A.

    1984-12-01

    A direct-comparison reference heat source (RHS), used for testing liquid-based solar collectors, is described. A major advantage of the RHS is its capability to measure the product of mass flow and specific heat directly in the test loop. Calibration tests are performed on two reference heat sources over a range of flowrates and inlet temperatures normally encountered in flat-plate solar collector testing (10 C to 95 C). It is shown that at low flowrates (less than or equal to 0.008 kg/s), localized boiling may introduce errors if the heater power density is not reduced as well, whereas operation at flowrates greater than 0.05 kg/s reduces the temperature rise across the RHS, increasing temperature measurement uncertainty. To achieve satisfactory results with an RHS, a stable inlet temperature, good flowrate control, and regulation of the power supplied to the heater are required.

  20. EnergyPlus Air Source Integrated Heat Pump Model

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Bo [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Energy and Transportation Science Division; Adams, Mark B. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Energy and Transportation Science Division; New, Joshua Ryan [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Energy and Transportation Science Division

    2016-03-30

    This report summarizes the development of the EnergyPlus air-source integrated heat pump model. It introduces its physics, sub-models, working modes, and control logic. In addition, inputs and outputs of the new model are described, and input data file (IDF) examples are given.

  1. Thermoelectricity without absorbing energy from the heat sources

    Science.gov (United States)

    Whitney, Robert S.; Sánchez, Rafael; Haupt, Federica; Splettstoesser, Janine

    2016-01-01

    We analyze the power output of a quantum dot machine coupled to two electronic reservoirs via thermoelectric contacts, and to two thermal reservoirs - one hot and one cold. This machine is a nanoscale analogue of a conventional thermocouple heat-engine, in which the active region being heated is unavoidably also exchanging heat with its cold environment. Heat exchange between the dot and the thermal reservoirs is treated as a capacitive coupling to electronic fluctuations in localized levels, modeled as two additional quantum dots. The resulting multiple-dot setup is described using a master equation approach. We observe an "exotic" power generation, which remains finite even when the heat absorbed from the thermal reservoirs is zero (in other words the heat coming from the hot reservoir all escapes into the cold environment). This effect can be understood in terms of a non-local effect in which the heat flow from heat source to the cold environment generates power via a mechanism which we refer to as Coulomb heat drag. It relies on the fact that there is no relaxation in the quantum dot system, so electrons within it have a non-thermal energy distribution. More poetically, one can say that we find a spatial separation of the first-law of thermodynamics (heat to work conversion) from the second-law of thermodynamics (generation of entropy). We present circumstances in which this non-thermal system can generate more power than any conventional macroscopic thermocouple (with local thermalization), even when the latter works with Carnot efficiency.

  2. Reprint of : Thermoelectricity without absorbing energy from the heat sources

    Science.gov (United States)

    Whitney, Robert S.; Sánchez, Rafael; Haupt, Federica; Splettstoesser, Janine

    2016-08-01

    We analyze the power output of a quantum dot machine coupled to two electronic reservoirs via thermoelectric contacts, and to two thermal reservoirs - one hot and one cold. This machine is a nanoscale analogue of a conventional thermocouple heat-engine, in which the active region being heated is unavoidably also exchanging heat with its cold environment. Heat exchange between the dot and the thermal reservoirs is treated as a capacitive coupling to electronic fluctuations in localized levels, modeled as two additional quantum dots. The resulting multiple-dot setup is described using a master equation approach. We observe an "exotic" power generation, which remains finite even when the heat absorbed from the thermal reservoirs is zero (in other words the heat coming from the hot reservoir all escapes into the cold environment). This effect can be understood in terms of a non-local effect in which the heat flow from heat source to the cold environment generates power via a mechanism which we refer to as Coulomb heat drag. It relies on the fact that there is no relaxation in the quantum dot system, so electrons within it have a non-thermal energy distribution. More poetically, one can say that we find a spatial separation of the first-law of thermodynamics (heat to work conversion) from the second-law of thermodynamics (generation of entropy). We present circumstances in which this non-thermal system can generate more power than any conventional macroscopic thermocouple (with local thermalization), even when the latter works with Carnot efficiency.

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

    Energy Technology Data Exchange (ETDEWEB)

    Mittereder, N.; Poerschke, A.

    2013-11-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-11-01

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

  5. Operation Performance of Air Source Heat Pump System for Space Heating in Tianjin

    Institute of Scientific and Technical Information of China (English)

    ZHAO Jun; CHEN Yan; QU Hang; LI Xinguo

    2007-01-01

    An air source heat pump system (ASHPS) used in an office building is set up and studied experimentally. Its operating performance in winter is evaluated based on test data and a comparative discussion is given on the effect of climate conditions and heating load ratio on the operation behavior.Then heating capacity variation caused by evaporator frosting is analyzed as well. Finally, the defrosting parameters and the technical feasibility are studied for a constant heating demand. The experimental results indicate that both the outlet water temperature drop and the system COP should be taken into account when setting defrosting parameters, and ASHPS is a viable technology for space heating and hotwater production in winter in Tianjin, which can maintain the room temperature above 19 ℃ when the outdoor temperature is -2 ℃.

  6. Innovative commercial ``ground source'' heat pump system sources and sinks: Engineering and economics

    Energy Technology Data Exchange (ETDEWEB)

    Sachs, H.M.; Lowenstein, A.I.; Henderson, H.I. Jr.; Carlson, S.W.; Risser, J.E.

    1998-07-01

    Geothermal heat pumps, which will be called GX systems in this paper, have been employed in specialty applications on both residential and commercial buildings for several decades. GX systems generally have very competitive life cycle costs, but somewhat higher initial costs. The incremental cost of the ground heat exchanger cost is close to the average cost per ton, so GX systems work best with very efficient building shells. Innovative methods can reduce the ground heat exchanger cost. These include better coupling of the heat exchange boreholes to the ground, hybrid systems that use low cost closed fluid coolers to supplement the ground heat exchanger where cooling loads dominate, open loop systems, and opportunistic systems that use sewage effluent or other non-standard sources for heat exchange. These approaches and their benefits are illustrated through five case studies.

  7. Medium-sized rock heat source systems. Mellanstora bergvaermesystem; Dimensioneringsanalyser

    Energy Technology Data Exchange (ETDEWEB)

    Spante, L.

    1989-05-24

    Results from these medium-sized rock heat source systems show that more functional trouble and inferior performance than expected are obtained if the borehole system is not adapted to the temperature demands of the heat pump cold transfer fluid. The design of the evaporator causes the evaporation temperature to become to low when the cold transfer fluid temperature reaches its lowest level for the year in two of the three plants studied. The third plant presents no functional trouble despite being operated at the same lowest cold transfer fluid temperature during the first years of operation. An analysis of complementary addition of boreholes in one of the plants with functional trouble reveals that the solution may be interesting if the heat pumps has to be capacity controlled for long periods during the heating season. In that plant the space for additional boreholes is limited, why the cost of this measure might be higher than the estimated SEK 240 per meter borehole. The computer code SBMA shows good agreement with measured weekly notations of the cold transfer fluid temperature during the first years of operation. The long-term temperature reduction caused by interaction between the closely located boreholes cannot be verified from only three years of operation. This fact gives cause for a follow-up of a number of medium-sized rock heat source systems for some additional years. 13 illus., 16 tabs. (author).

  8. Numerical analysis of heat exchange processes for the ground source heat pump system

    Science.gov (United States)

    Saito, H.; Muto, H.; Moritani, S.; Kohgo, Y.; Hamamoto, S.; Takemura, T.; Ohnishi, J.; Komatsu, T.

    2012-12-01

    Ground source heat pump systems (GSHP) use ground or groundwater as a heat source. They can achieve much higher coefficient of performance (COP) than conventional air source heat pump systems because the temperature of the ground is much more stable than that of the air. Heat energy in the ground is then viewed as one of the renewable energy sources. GSHP has been receiving great interests among countries in North America and Western Europe, as well as some developed countries in Asia because it can potentially reduce energy consumption and greenhouse gas emission. While GSHP can inject heat from the buildings to the ground for cooling during the summer, it can pump heat stored in the ground for heating during the winter. As some physical, chemical, and biological properties of the ground and groundwater are temperature dependent, running GSHP can eventually affect groundwater quality. The main objective of this project was to develop a model that allows predicting not only ground and groundwater temperatures but also changes in physical, chemical, and biological properties of ground and groundwater with GSHP under operations. This particular study aims at simulating heat exchange and transfer processes in the ground for a vertical-loop closed GSHP system. In the closed GSHP system, an anti-freezing solution is circulated inside the closed-loop tube, called U-tube, that is buried in the ground. Heat is then transferred to the anti-freezing solution in the U-tube by a heat exchanger. In this study we used HYDRUS to predict temperature of the anti-freezing solution, as well as that of the ground. HYDRUS allows one to simulate variably-saturated water flow and solute and heat transport in porous media numerically in two- and three-dimensional domains with great flexibility in defining boundary conditions. At first changes in anti-freezing solution temperatures measured were predicted in response to Thermal Response Test (TRT) conducted at our study site. Then, heat

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-11-25

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

  10. Development of a Portable Thermogenerator for Uncontrolled Heat Sources

    Science.gov (United States)

    Juanicó, Luis E.; Rinalde, Fabián; Taglialavore, Eduardo; Molina, Marcelo

    2013-07-01

    This paper presents the development of a portable thermogenerator designed to work on uncontrolled heat sources. Its thermal behavior regarding both steady-state and transient regimens was analytically described and numerically solved by using a lumped capacity model. The ranges of heating power and power increasing rates have been determined to ensure safe operation, or give users advance warning in case of failure. In addition, this model is a useful tool for designing a controller system based on which a feasible thermogenerator can be developed. Experimental tests performed on a prototype based on a commercial BiTe module have demonstrated this goal.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2001-07-01

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

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

    DEFF Research Database (Denmark)

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

    2016-01-01

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

  13. Investigation of the Performance of a Heat Pump Using Waste Water as a Heat Source

    Directory of Open Access Journals (Sweden)

    Ali Kahraman

    2009-08-01

    Full Text Available In this research, a water-water heat pump system using waste water as a heat source, a type that is not often used in Turkey and the World, was experimentally modeled. The experiments were performed under the conditions of simulated waste water temperature values of 20 °C, 30 °C and 40 °C. Inlet and outlet water temperatures of the evaporator and condenser, water flow rates in the evaporator and condenser circuits, pressures at the compressor inlet and outlet and power consumption of the system were measured. The heating coefficients of performance were calculated based on the measurements. It was found that the maximum temperature in the energy storage tank was about 50.6 °C. For the heat source temperatures of 20 °C, 30 °C and 40 °C, the heating coefficients of the performance of the system became 3.36, 3.43 and 3.69, respectively, 6 min. after the start time of the experiments and then they were decreased to 1.87, 1.83 and 1.77 with increasing water temperature in the condenser tank. The mean uncertainty value of the measurement parameters was found to be about ±2.47%. Finally, for the purpose of meeting hot water need as well as floor heating system requirements, it is seen that energy quality level of a waste low grade temperature heat source can be increased by using a heat pump system.

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

    Science.gov (United States)

    Vantúch, Martin; Kaduchová, Katarína; Lenhard, Richard

    2016-06-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-01-01

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

  16. North Village Ground Source Heat Pump Demonstration Project

    Energy Technology Data Exchange (ETDEWEB)

    Redderson, Jeff

    2015-08-03

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

  17. Indoor heating sources and respiratory symptoms in nonsmoking women.

    Science.gov (United States)

    Triche, Elizabeth W; Belanger, Kathleen; Bracken, Michael B; Beckett, William S; Holford, Theodore R; Gent, Janneane F; McSharry, Jean-Ellen; Leaderer, Brian P

    2005-05-01

    Secondary heating appliances are important indoor sources of air pollution, including particulate matter, nitrogen dioxide (NO2), and sulfur dioxide (SO2). We hypothesized that the use of secondary heating sources increases respiratory symptoms in women living in nonsmoking households and specifically that concentrations of SO2 and NO2 emitted from heating sources are associated with respiratory symptoms. Mothers who delivered babies at 12 hospitals in Connecticut and Virginia (1993-1996) were enrolled. There were 888 women who contributed symptom and exposure information during the winter heating season (15 October to 15 April), for a total of 9783 reporting periods (median = 12 reporting periods per woman, interquartile range 11-12). Adjusted rate ratios (RRs) of effects of source use and measured concentrations on rate of days with symptoms were obtained using generalized estimating equations for a log-linear Poisson model, controlling age, education, race, history of allergies, number of children, dwelling type, and residence state. In adjusted models, each hour-per-day increase in kerosene heater use is associated with an increase in wheezing (RR = 1.06; 95% confidence interval (CI) = 1.01-1.11). Each hour of fireplace use is associated with increased cough (1.05; 1.01-1.09), sore throat (1.04; 1.00-1.08), and marginally with chest tightness (1.05; 0.99-1.12). Each 10 ppb increase in SO2 (a proxy for sulfate aerosol) is associated with increased wheezing (1.57; 1.10-2.26) and chest tightness (1.32; 1.01-1.71). Emissions from fireplaces, gas space heaters, and kerosene heaters may contribute to respiratory symptoms in a population of nonsmoking women.

  18. Temperature distribution of an infinite slab under point heat source

    Directory of Open Access Journals (Sweden)

    Wu Zhao-Chun

    2014-01-01

    Full Text Available The temperature field in an infinite slab under an instantaneous or continuous point heat source is studied numerically. The numerical results reveal the temperature distribution and its change regularity, which are significant for the temperature control encountered in many practical manufacturing processes, such as the laser treatment processes on the surface of films, welding and cutting, and even the design of measuring devices for thermal properties of material.

  19. Cassini RTG program. Monthly technical progress report, September 29, 1997--October 26, 1997

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-11-24

    This report describes work on the contract to provide Radioisotope Thermoelectric Generators (RTG) and Ancillary Activities in support of the Cassini Spacecraft launch. The craft was successfully launched on October 15, 1997. Early telemetry results show excellent performance from the three launched RTG modules. A major share of this report describes safety analyses for contamination radii in the event of launch failures and generator destruction, as well as launch related activities.

  20. Thermal vacuum testing of a MHW RTG after 17 years in storage

    Science.gov (United States)

    Tolson, B. Allen; Brewer, Gene D.; Mintz, Gerald V.; Reynoso, Tony; Pugh, Barry K.; Davis, Stephen B.; Hoye, Timothy J.

    2001-02-01

    In April of 2000, thermal vacuum testing was performed on one of the Multi-Hundred Watt (MHW) Radioisotopic Thermoelectric Generator (RTG) units that were fabricated in the early 1970's for the Voyager mission. The MHW RTG units are configured with electrical heaters, which allowed the varying of input power, so the output power could be measure at different input levels. The results of a thermal vacuum test earlier this year showed the generators are still in good working order. .

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

    DEFF Research Database (Denmark)

    Tol, Hakan; Dinçer, Ibrahim; Svendsen, Svend

    2012-01-01

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

  2. Progress report No. 29 for a program of thermoelectric generator testing and RTG degradation mechanisms evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Stapfer, G.; Garvey, L.

    1979-02-01

    Thermal conductivity measurements of the P-type and N-type selenide alloys after 17000 hours and 4100 hours, respectively, are in good agreement with the 3M Co data. Ingradient testing of N-legs after 6600 hours show comparable performance to the reported 3M data. Ingradient testing of P-legs at accelerated test conditions, have completed 3600 hours and performance shows reasonable correlation with accelerated temperature and current gradients. N-type samples from both the Thermal Conductivity Tests and Ingradient Performance Tests were removed from test for examination. All samples were found to be severely cracked upon removal from the test fixtures. Metallurgical and x-ray diffraction analysis showed (1) extensive cracking had occurred in the lower half (cold end) of the legs and (2) a crystallographic phase change occurred in the upper half (hot end) of the legs from monoclinic to orthorhombic. It is postulated that the phase change that occurs on heating aggravates the micro-cracks that exist in the as fabricated leg. An initial evaluation of the performance of the Voyager 1 and 2 RTG's after 12,000 hours of operation versus the DEGRA performance prediction code, shows excellent agreement. (WHK)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1995-04-01

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

  4. Convection heat transfer from discrete heat sources in a liquid cooled rectangular channel

    Energy Technology Data Exchange (ETDEWEB)

    Bhowmik, H. [Department of Mechanical Engineering, Dhaka University of Engineering and Technology, Gazipur 1700 (Bangladesh); Tso, C.P. [Faculty of Engineering and Technology, Multimedia University, Jalan Ayer Keroh Lama, 75450 Melaka (Malaysia); Tou, K.W.; Tan, F.L. [School of Mechanical and Production Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798 (Singapore)

    2005-11-01

    Steady-state experiments are performed to study general convective heat transfer from an in-line four simulated electronic chips in a vertical rectangular channel using water as the working fluid. The experimental data covers a wide range for laminar flow under natural, mixed and forced convection conditions with Reynolds number based on channel hydraulic diameter ranging from 40 to 2220 and Reynolds number based on heat source length ranging from 50 to 2775, respectively. The heat flux ranges from 0.1W/cm{sup 2} to 0.6W/cm{sup 2}. The inlet water temperature is at 24{sup o}C. The effect of heat fluxes, flow rates and geometrical parameters such as chip number are investigated. The experimental results indicate that the heat transfer coefficient is strongly affected by Reynolds number and fully-developed values of heat transfer coefficient are reached before the first chip. Empirical correlations are developed for relations using Nusselt number, Reynolds number and Grashof number, based on channel hydraulic diameter. (author)

  5. Work output and efficiency at maximum power of linear irreversible heat engines operating with a finite-sized heat source.

    Science.gov (United States)

    Izumida, Yuki; Okuda, Koji

    2014-05-01

    We formulate the work output and efficiency for linear irreversible heat engines working between a finite-sized hot heat source and an infinite-sized cold heat reservoir until the total system reaches the final thermal equilibrium state with a uniform temperature. We prove that when the heat engines operate at the maximum power under the tight-coupling condition without heat leakage the work output is just half of the exergy, which is known as the maximum available work extracted from a heat source. As a consequence, the corresponding efficiency is also half of its quasistatic counterpart.

  6. Low Temperature Heat Source Utilization Current and Advanced Technology

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, James H. Jr.; Dambly, Benjamin W.

    1992-06-01

    Once a geothermal heat source has been identified as having the potential for development, and its thermal, physical, and chemical characteristics have been determined, a method of utilization must be decided upon. This compendium will touch upon some of these concerns, and hopefully will provide the reader with a better understanding of technologies being developed that will be applicable to geothermal development in East Africa, as well as other parts of the world. The appendices contain detailed reports on Down-the-Well Turbo Pump, The Vapor-Turbine Cycle for Geothermal Power Generation, Heat Exchanger Design for Geothermal Power Plants, and a Feasibility Study of Combined Power and Water Desalting Plant Using Hot Geothermal Water. [DJE-2005

  7. HTGR nuclear heat source component design and experience

    Energy Technology Data Exchange (ETDEWEB)

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

    1982-05-01

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

  8. Experimental Study of Melting Heat Transfer in an Enclosure with Three Discrete Protruding Heat Sources

    Institute of Scientific and Technical Information of China (English)

    YonglinJu; ZhongqiChen; 等

    1998-01-01

    To explore the possibility of using solid-liquid phase change cooling to those periodically or intermittently operated electronic equipment,a detail of experimental study of time-dependent melting heat transfer in a rectangular enclosure with three discrete proturding heat sources is presented.A series of experimental measurement in an enclosure with phase change materials (PCM)of n-octadecane of experimental measurement in an enclosure with phase change materials(PCM) of -octadecane heated by three discrete protruding heat sources at a constant rate on one of its vertical wall has been described.The opposite wall of the enclosure is cooled at a constant temperature and all other walls of the enclosure are insulated.The time-dependent solid-liquid shapes of the interface during melting process,the variation of surface temperature and the effects of sulbcooling are investigated.An empirical correlation predicting the relationship between the liquid phase fraction and subcooling is given.

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

    NARCIS (Netherlands)

    Ooster, van 't A.; Wit, de J.; Janssen, E.G.O.N.; Ruigrok, J.

    2008-01-01

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

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

    Science.gov (United States)

    Tiang, Kor L; Ooi, Ean H

    2016-08-01

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

  11. Convective heat transfer enhancement of laminar flow of latent functionally thermal fluid in a circular tube with constant heat flux: internal heat source model and its application

    Institute of Scientific and Technical Information of China (English)

    张寅平; 胡先旭; 郝磬; 王馨

    2003-01-01

    This paper analyzes the convective heat transfer enhancement mechanism of latent heat functionally thermal fluid. By using the proposed internal heat source model, the influence of each factor affecting the heat transfer enhancement of laminar flow in a circular tube with constant heat flux is analyzed. The main influencing factors and the mechanisms of heat transfer enhancement are clarified, and the influences of the main factors on the heat transfer enhancement are quantitatively analyzed. A modified Nusselt number for internal flow is introduced to describe more effectively the degree of heat transfer enhancement for latent functionally thermal fluid.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-10-27

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

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

    Directory of Open Access Journals (Sweden)

    V. A. Sednin

    2010-01-01

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

  14. Optimal configuration for a finite high-temperature source heat engine cycle with the complex heat transfer law

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    The optimal configuration of a heat engine operating between a finite high-temperature source and an infinite low-temperature reservoir is derived by using finite time thermodynamics based on a complex heat transfer law,including Newtonian heat transfer law,linear phenomenological heat transfer law,radiative heat transfer law,Dulong-Petit heat transfer law,generalized convective heat transfer law and generalized radiative heat transfer law,q ∝(△T n). In the engine model the only irreversibility of finite rate heat transfer is considered. The optimal relation between the power output and efficiency of the heat engine is also derived by using an equivalent temperature of the hot reservoir. The obtained results include those obtained in recent literature and can provide some theoretical guidance for the designs of practical engines.

  15. Optimal configuration for a finite high-temperature source heat engine cycle with the complex heat transfer law

    Institute of Scientific and Technical Information of China (English)

    LI Jun; CHEN LinGen; SUN FengRui

    2009-01-01

    The optimal configuration of a heat engine operating between a finite high-temperature source and an infinite low-temperature reservoir is derived by using finite time thermodynamics based on a complex heat transfer law, including Newtonian heat transfer law, linear phenomenological heat transfer law, radiative heat transfer law, Dulong-Petit heat transfer law, generalized convective heat transfer law and generalized radiative heat transfer law, q∝ (△Tn). In the engine model the only irreversibility of finite rate heat transfer is considered. The optimal relation between the power output and efficiency of the heat engine is also derived by using an equivalent temperature of the hot reservoir. The obtained re-sults include those obtained in recent literature and can provide some theoretical guidance for the de-signs of practical engines.

  16. Investigation of the heat source(s) of the Surprise Valley Geothermal System, Northern California

    Science.gov (United States)

    Tanner, N.; Holt, C. D.; Hawkes, S.; McClain, J. S.; Safford, L.; Mink, L. L.; Rose, C.; Zierenberg, R. A.

    2016-12-01

    Concerns about environmental impacts and energy security have led to an increased interest in sustainable and renewable energy resources, including geothermal systems. It is essential to know the permeability structure and possible heat source(s) of a geothermal area in order to assess the capacity and extent of the potential resource. We have undertaken geophysical surveys at the Surprise Valley Hot Springs in Cedarville, California to characterize essential parameters related to a fault-controlled geothermal system. At present, the heat source(s) for the system are unknown. Igneous bodies in the area are likely too old to have retained enough heat to supply the system, so it is probable that fracture networks provide heat from some deeper or more distributed heat sources. However, the fracture system and permeability structure remain enigmatic. The goal of our research is to identify the pathways for fluid transport within the Surprise Valley geothermal system using a combination of geophysical methods including active seismic surveys and short- and long-period magnetotelluric (MT) surveys. We have collected 14 spreads, consisting of 24 geophones each, of active-source seismic data. We used a "Betsy Gun" source at 8 to 12 locations along each spread and have collected and analyzed about 2800 shot-receiver pairs. Seismic velocities reveal shallow lake sediments, as well as velocities consistent with porous basalts. The latter, with velocities of greater than 3.0 km/s, lie along strike with known hot springs and faulted and tilted basalt outcrops outside our field area. This suggests that basalts may provide a permeable pathway through impermeable lake deposits. We conducted short-period (10Hz-60kHz) MT measurements at 33 stations. Our short-period MT models indicate shallow resistive blocks (>100Ωm) with a thin cover of more conductive sediments ( 10Ωm) at the surface. Hot springs are located in gaps between resistive blocks and are connected to deeper low

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-01-15

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-05-24

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

  19. Research on modeling of heat source for electron beam welding fusion-solidification zone

    Institute of Scientific and Technical Information of China (English)

    Wang Yajun; Fu Pengfei; Guan Yongjun; Lu Zhijun; Wei Yintao

    2013-01-01

    In this paper,the common heat source model of point and linear heat source in the numerical simulation of electron beam welding (EBW) were summarized and introduced.The combined point-linear heat source model was brought forward and to simulate the welding temperature fields of EBW and predicting the weld shape.The model parameters were put forward and regulated in the combined model,which included the ratio of point heat source to linear heat source Qpr and the distribution of linear heat source Lr.Based on the combined model,the welding temperature fields of EBW were investigated.The results show that the predicted weld shapes are conformable to those of the actual,the temperature fields are reasonable and correct by simulating with combined point-linear heat source model and the typical weld shapes are gained.

  20. Using Ground Source Heat Pumps for Renewable Energy

    Directory of Open Access Journals (Sweden)

    Xhevat BERISHA

    2017-04-01

    Full Text Available This paper provides background information on the current energy supply, energy demand, and energy sources in Kosovo. Moreover, it presents the country‟s current level of applying alternative energy sources. Additionally, this paper focuses on geothermal energy as a renewable energy resource with the potential to contribute to a sustainable use of resources to meet renewable energy and energy efficiency requirements of the European Union (EU, “EU 20 20 by 2020” policy. Hence, a careful analysis is included on how to approach the aforementioned targets through investments in geothermal energy through providing an energy consumption forecast and analysing geothermal energy projects in Europe and specifically in Kosovo. This paper carefully represents the potential usage of geothermal energy in Kosovo, renewable energy source targets, and it addresses the importance of laws, regulations, and reports regarding the utilization of this type of energy. Economic and environmental implications of investing in geothermal energy - geothermal heat pumps for the case of International Village are additionally analysed. Lastly, recommendations and conclusions, for future actions, are derived and addressed to relevant stakeholders, primarily policy-makers, and government representatives.

  1. Combined radiative and natural or forced convective heat transfer between parallel vertical plates with two-dimensional discrete heat sources

    Energy Technology Data Exchange (ETDEWEB)

    Nickell, T.W.

    1988-01-01

    This study numerically analyzes combined radiative and natural or forced convective heat transfer between vertical parallel plates with two-dimensional discrete heat sources. The numerical method was verified by comparing its results with other published experimental data and the agreement was excellent. It is shown that radiative heat transfer is a significant and useful mode of heat transfer in combination with both natural and forced convection in this situation and cannot be neglected. Radiative heat transfer accounted for 50-60% or more of the total heat transfer in some cases, and usually approximately 30-35% on the top of a discrete heat source. This fact can be used to advantage in the thermal design of electronic circuit boards.

  2. Cobalt-60 heat source demonstration program. Phase III. Fabrication. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1973-06-01

    Significant accomplishments completed during Phase III of the /sup 60/Co Heat Source Demonstration program include the following: encapsulation of 2 MCi of /sup 60/Co; fabrication of the heat source, including the ASME coded pressure vessel/core assembly, and biological shielding; endurance testing of a prototype heat pipe for a period of 28 months; fabrication and qualification of the heat pipe emergency cooling subsystem; issue of the safety evaluation report, reference 3, and the operations manual, reference 4; and heat source assembly. The planned demonstration test program was modified to include testing of a total power system. Based on an evaluation of available power conversion systems, which included the closed-cycle Brayton and organic Rankine systems, the closed-cycle Brayton system was selected for use. Selection was based on advantages offered by the direct coupling of this conversion system with the gas-cooled heat source. In implementing the test program, the AiResearch BCD power conversion system was to be coupled to the heat source following initial heat source performance testing and part way through the endurance test. In accordance with the program redirection the following Phase IV checkout operations were completed to evaluate procedural and hardware acceptability: heat source dummy fueling; fueling cask sielding survey; and heat source shielding survey (single pin). Completion of these latter activities verified the acceptability of critical characteristics of the heat source and its supporting equipment.

  3. Comparison on welding mode characteristics of arc heat source for heat input control in hybrid welding of aluminum alloy

    Science.gov (United States)

    Song, Moo-Keun; Kim, Jong-Do; Oh, Jae-Hwan

    2015-03-01

    Presently in shipbuilding, transportation and aerospace industries, the potential to apply welding using laser and laser-arc hybrid heat sources is widely under research. This study has the purpose of comparing the weldability depending on the arc mode by varying the welding modes of arc heat sources in applying laser-arc hybrid welding to aluminum alloy and of implementing efficient hybrid welding while controlling heat input. In the experimental study, we found that hybrid welding using CMT mode produced deeper penetration and sounder bead surface than those characteristics produced during only laser welding, with less heat input compared to that required in pulsed arc mode.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-01-15

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

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

    Energy Technology Data Exchange (ETDEWEB)

    R.K. Johnson

    2013-09-01

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

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

    Directory of Open Access Journals (Sweden)

    Maksimov Vyacheslav I.

    2015-01-01

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

  7. Optimal configuration for a finite low-temperature source refrigerator cycle with heat transfer law

    Directory of Open Access Journals (Sweden)

    Jun Li, Lingen Chen, Yanlin Ge, Fengrui Sun

    2016-01-01

    Full Text Available The optimal configuration of a refrigeration cycle operating between a finite low-temperature source and an infinite high-temperature sink are derived by using finite time thermodynamics based on a complex heat transfer law, including Newtonian heat transfer law, linear phenomenological heat transfer law, radiative heat transfer law, Dulong-Petit heat transfer law, generalized convective heat transfer law and generalized radiative heat transfer law. In the refrigeration cycle model the only irreversibility of finite rate heat transfer is considered. The optimal relation between cooling load and coefficient of performance (COP of the refrigeration cycle is also derived by using an equivalent temperature of low-temperature source. The obtained results include those with various heat transfer laws and infinite low-temperature source, and can provide some theoretical guidelines for the designs of practical refrigerators.

  8. Cassini RTG Program. Monthly technical progress report, 27 November--31 December 1995

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-01-24

    This monthly technical progress report provided information on the following tasks: spacecraft integration and liaison; engineering support; safety analysis; qualified unicouple fabrication; ETG fabrication, assembly, and test; ground support equipment (GSE); RTG shipping and launch support; designs, reviews, and mission applications; project management, quality assurance, and reliability, and contractor acquired government owned (CAGO) property acquisition.

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

    Science.gov (United States)

    Agll, Abdulhakim Amer

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

  10. Heat and power sources based on nuclear shipbuilding technologies

    Energy Technology Data Exchange (ETDEWEB)

    Veshnyakov, K.; Fadeev, Y.; Panov, Y.; Polunichev, V. [JSC Afrikantov OKBM, Nizhny Novgorod (Russian Federation)

    2009-07-01

    The report gives information on the application of power units with small-power nuclear reactors as advanced energy sources to provide world consumers with electric power, domestic and industrial heat and fresh water. The report describes the technical concept of ABV unified reactor plant (RP) for floating and ground small power plants (SPP) developed in JSC 'Afrikantov OKBM'. The report contains the technical specification of the ABV RP utilizing an integral water-cooled reactor with thermal power of 38 to 45 MW, natural coolant circulation and improved inherent safety, as well as main characteristics of the reactor and core fuel ensuring acceptable mobility of the RP and NPP as a whole. The indicated refueling interval is 10-12 years. The report gives a detailed description of the concept for RP safety provision and compliance with international radiation and nuclear safety requirements, as well as the description of passive and other safety systems securing stability to any low-probability internal events, personnel errors and external impacts. The report provides data on application and technological properties of the floating and ground SPPs with a unified ABV RP; absence of spent fuel and radioactive waste at floating nuclear power plants (FNPP); FNPP transportation to consumers in a ready-to-operate state; arrangement, operation and disposal requirements.

  11. Conduction heat transfer in semi-infinite and infinite regions with discrete heat sources

    Energy Technology Data Exchange (ETDEWEB)

    Venkataraman, Nellore S.; Castillo, Omar E. Meza [Puerto Rico Univ., Dept. of Mechanical Engineering, Mayaguez (Puerto Rico)

    2006-01-15

    The steady state temperature distribution in semi-infinite slabs and infinite quadrants due to two- and three-dimensional discrete heating sources shaped in the form of thin electric current carrying wires has been determined. The temperature field is obtained using Green's function integral techniques. The solutions obtained here are compared with numerical solutions obtained from a commercial software package. It is shown that for the cases considered here we get closed form solutions or solutions in the form of simple numerically calculable integrals which are far superior to numerical methods in terms of elegance and labor involved for parametric studies. The behavior of the non-dimensional temperature with the various relevant parameters is discussed. (Author)

  12. Synaptic alterations in the rTg4510 mouse model of tauopathy.

    Science.gov (United States)

    Kopeikina, Katherine J; Polydoro, Manuela; Tai, Hwan-Ching; Yaeger, Erich; Carlson, George A; Pitstick, Rose; Hyman, Bradley T; Spires-Jones, Tara L

    2013-04-15

    Synapse loss, rather than the hallmark amyloid-β (Aβ) plaques or tau-filled neurofibrillary tangles (NFT), is considered the most predictive pathological feature associated with cognitive status in the Alzheimer's disease (AD) brain. The role of Aβ in synapse loss is well established, but despite data linking tau to synaptic function, the role of tau in synapse loss remains largely undetermined. Here we test the hypothesis that human mutant P301L tau overexpression in a mouse model (rTg4510) will lead to age-dependent synaptic loss and dysfunction. Using array tomography and two methods of quantification (automated, threshold-based counting and a manual stereology-based technique) we demonstrate that overall synapse density is maintained in the neuropil, implicating synapse loss commensurate with the cortical atrophy known to occur in this model. Multiphoton in vivo imaging reveals close to 30% loss of apical dendritic spines of individual pyramidal neurons, suggesting these cells may be particularly vulnerable to tau-induced degeneration. Postmortem, we confirm the presence of tau in dendritic spines of rTg4510-YFP mouse brain by array tomography. These data implicate tau-induced loss of a subset of synapses that may be accompanied by compensatory increases in other synaptic subtypes, thereby preserving overall synapse density. Biochemical fractionation of synaptosomes from rTg4510 brain demonstrates a significant decrease in expression of several synaptic proteins, suggesting a functional deficit of remaining synapses in the rTg4510 brain. Together, these data show morphological and biochemical synaptic consequences in response to tau overexpression in the rTg4510 mouse model. Copyright © 2012 Wiley Periodicals, Inc.

  13. Adiabatic heating and convection caused by a fixed-heat-flux source in a near-critical fluid.

    Science.gov (United States)

    Soboleva, E B

    2003-10-01

    Dynamics and heat transfer in a near-critical fluid in a square cavity with a finite heat source located at the bottom are studied numerically. A thermally insulated enclosure and a fixed-heat-flux source are considered. The two-dimensional simulation is based on the full Navier-Stokes equations with two-scale splitting of the pressure and the van der Waals equation of state. It is shown that the piston effect is independent of convection. Near the critical point, this effect becomes independent of criticality and convective motions are damped.

  14. Harvesting Nanocatalytic Heat Localized in Nanoalloy Catalyst as a Heat Source in a Nanocomposite Thin Film Thermoelectric Device.

    Science.gov (United States)

    Zhao, Wei; Shan, Shiyao; Luo, Jin; Mott, Derrick M; Maenosono, Shinya; Zhong, Chuan-Jian

    2015-10-20

    This report describes findings of an investigation of harvesting nanocatalytic heat localized in a nanoalloy catalyst layer as a heat source in a nanocomposite thin film thermoelectric device for thermoelectric energy conversion. This device couples a heterostructured copper-zinc sulfide nanocomposite for thermoelectrics and low-temperature combustion of methanol fuels over a platinum-cobalt nanoalloy catalyst for producing heat localized in the nanocatalyst layer. The possibility of tuning nanocatalytic heat in the nanocatalyst and thin film thermoelectric properties by compositions points to a promising pathway in thermoelectric energy conversion.

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

    Science.gov (United States)

    Song, Yulong; Ye, Zuliang; Cao, Feng

    2017-08-01

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

  16. 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.

  17. Thermal Stresses in an Anisotropic Thin Plate Subjected to Moving Plane Heat Sources

    Directory of Open Access Journals (Sweden)

    Malak Naji

    2014-04-01

    Full Text Available The aim of this study is to numerically simulate the plane moving heat source through anisotropic mild steal thin plate. Heat conduction problems in anisotropic material, where the thermal conductivity varies with direction and involving a moving heat source have several industrial applications, such like metal cutting, flame or laser hardening of metals, welding and others. The parabolic heat conduction model is used for the prediction of the temperature history. The temperature distribution inside the plate is determined from the solution of heat equation. Thus, the heat equation is solved numerically using finite deference method and the temperature distributions are determined. The thermal stresses in this case are, also, investigated and computed numerically. It is found that the thermal conductivity ratio affect in both temperature and thermal stresses distributions, in additional to the speed and heat source intensity.

  18. Thermodynamic formalism of minimum heat source temperature for driving advanced adsorption cooling device

    Science.gov (United States)

    Saha, Bidyut Baran; Chakraborty, Anutosh; Koyama, Shigeru; Srinivasan, Kandadai; Ng, Kim Choon; Kashiwagi, Takao; Dutta, Pradip

    2007-09-01

    This letter presents a thermodynamic formulation to calculate the minimum driving heat source temperature of an advanced solid sorption cooling device, and it is validated with experimental data. This formalism has been developed from the rigor of the Boltzmann distribution function and the condensation approximation of adsorptive molecules. An interesting and useful finding has been established from this formalism that it is possible to construct a solid sorption refrigeration device that operates in a cycle transferring heat from a low temperature source to a heat sink with a driving heat source at a temperature close to but above ambient.

  19. General expression of double ellipsoidal heat source model and its error analysis

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    In order to analyze the maximum power density error with different heat flux distribution parameter values for double ellipsoidal heat source model, a general expression of double ellipsoidal heat source model was derived from Goldak double ellipsoidal heat source model, and the error of maximum power density was analyzed under this foundation. The calculation error of thermal cycling parameters caused by the maximum power density error was compared quantitatively by numerical simulation. The results show that for guarantee the accuracy of welding numerical simulation, it is better to introduce an error correction coefficient into the Goldak double ellipsoidal heat source model expression. And, heat flux distribution parameter should get higher value for the higher power density welding methods.

  20. Simulation of Velocity and Temperature Distributions of Displacement Ventilation System with Single or Double Heat Sources

    Institute of Scientific and Technical Information of China (English)

    Wenfei Wu; Xuan Wu; Yanhui Feng; Xinxin Zhang

    2007-01-01

    In order to obtain a better understanding of flow characteristics of displacement ventilation, the three-dimensional numerical models are developed using the CFD technology. The numerical simulation results are verified by experiments, based on this, the velocity and temperature distribution of three-dimensional displacement ventilation system with single and double heat sources are studied. Velocity and temperature fields under two different cases of heat source are analyzed and compared. The numerical results show that there are three layers in vertical temperature fields of displacement ventilation system with single or double heat sources, and the vertical temperature distribution of single heat source is different from that of double heat sources. When indoor load is large, the comfort requirement of people indoor can't be satisfied with displacement ventilation system only, thus an additional refrigeration system is necessary. Furthermore, under the condition of two heat sources, the displacement ventilation parameters can't be computed simply according to single heat source inlet parameters, therefore the interaction between heat sources should be considered.

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

    DEFF Research Database (Denmark)

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

    2012-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2017-04-24

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

  3. Temperature and Humidity Independent Control Research on Ground Source Heat Pump Air Conditioning System

    Science.gov (United States)

    Chen, G.; Wang, L. L.

    Taking green demonstration center building air conditioning system as an example, this paper presents the temperature and humidity independent control system combined with ground source heat pump system, emphasis on the design of dry terminal device system, fresh air system and ground source heat pump system.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-09-01

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

  5. Thermal Management Controller for Heat Source Temperature Control and Thermal Management

    Institute of Scientific and Technical Information of China (English)

    HUANGFU Yi; WU Jing-yi; WANG Ru-zhu; LI Sheng

    2009-01-01

    In many heat recovery processes, temperature control of heat source is often required to ensure safety and high efficiency of the heat source equipment. In addition, the management of recovered heat is important for the proper use of waste heat. To this aim, the concept of thermal management controller (TMC), which can vary heat transfer rate via the volume variation of non-condensable gas, was presented. Theoretical model and experimental prototype were established. Investigation shows that the prototype is effective in temperature control. With water as the working fluid, the vapor temperature variation is only 1.3 ℃ when the heating power varies from 2.5 to 10.0 kW. In variable working conditions, this TMC can automatically adjust thermal allocation to the heat consumer.

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

    Science.gov (United States)

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

    2015-08-01

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

  7. Thermal Stresses in an Anisotropic Thin Plate Subjected to Moving Line Heat Sources

    Directory of Open Access Journals (Sweden)

    Malak Naji

    2014-02-01

    Full Text Available The aim of this present study is to investigate thermal stresses inside a thin anisotropic mild steal plate during moving line heat source. The parabolic heat conduction model is used for the prediction of the temperature history. The temperature distributions are determined numerically using finite difference method. Thermal stresses are computed numerically. It is found that the thermal conductivity ratio affect in both temperature and thermal stresses distributions, in additional to the speed and heat source intensity.

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

    Energy Technology Data Exchange (ETDEWEB)

    Voutta, Robert

    2016-04-22

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

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

    OpenAIRE

    Voutta, Robert

    2016-01-01

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

  10. Development of dual-source hybrid heat pump system using groundwater and air

    Energy Technology Data Exchange (ETDEWEB)

    Nam, Yujin; Ooka, Ryozo [Cw403 Institute of Industry Science, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8505 (Japan); Shiba, Yoshiro [Zeneral Heatpump Industry Co., Ltd., Nagoya 459-8001 (Japan)

    2010-06-15

    To achieve high heat pump efficiency, groundwater heat pump (GWHP) system uses groundwater, which is relatively stable AT temperature compared with outdoor air, as a heat source. However, it is difficult to meet annual heating and cooling loads using only groundwater as a heat source. In order to optimize the operation method of GWHP systems, it is necessary to develop a system utilizing both groundwater and air sources according to the building load conditions. Furthermore, during intermediate seasons (such as spring and autumn) with reduced heating and cooling loads, GWHP system is less efficient than air source heat pump (ASHP) system according to temperature conditions. In order to more efficiently use GWHP systems, it is necessary to develop a system which utilizes both groundwater and air sources according to temperature conditions and building loads. This research has developed a GWHP system that employs a hybrid heat pump system with groundwater wells using dual groundwater and air heat sources. In this paper, the annual performance of the developed system has been calculated, and several case studies have been conducted on the effect of introduction location, refrigerant and pumping rate. Furthermore, the coefficient of system performance and the effects on underground environments have been evaluated by real-scale experiment using two wells. (author)

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

    Directory of Open Access Journals (Sweden)

    Sławomir Rabczak

    2016-11-01

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

  12. Heat Capacity Mapping Mission Digital Source: 1978-1980

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — NASA's Heat Capacity Mapping Mission (HCMM) project collected Earth data in the visible and thermal bands between April 1978 and September 1980. This was an...

  13. Heat Capacity Mapping Mission Digital Source: 1978-1980

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — NASA's Heat Capacity Mapping Mission (HCMM) project collected Earth data in the visible and thermal bands between April 1978 and September 1980. This was an...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-07-01

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

  15. Verification of Conjugate Heat Transfer Models in a Closed Volume with Radiative Heat Source

    Directory of Open Access Journals (Sweden)

    Maksimov Vyacheslav I.

    2016-01-01

    Full Text Available The results of verification of mathematical model of convective-conductive heat transfer in a closed volume with a thermally conductive enclosing structures are presented. Experiments were carried out to determine the temperature of floor premises in the working conditions of radiant heating systems. Comparison of mathematical modelling of temperature fields and experiments showed their good agreement. It is concluded that the mathematical model of conjugate heat transfers in the air cavity with a heat-conducting and heat-retaining walls correspond to the real process of formation of temperature fields in premises with gas infrared heaters system.

  16. Thermoacoustic Instability in a Rijke Tube with a Distributed Heat Source

    Directory of Open Access Journals (Sweden)

    Xiaochuan Yang

    2015-01-01

    Full Text Available A Rijke tube with a distributed heat source is investigated. Driven by the widely existing thermoacoustic instability in lean premixed gas turbine combustors, this work aims to explore the physicochemical underpinning and assist in the elucidation and analysis of this problem. The heat release model consists of a row of distributed heat sources with individual heat release rates. The integrated heat release rate is then coupled with the acoustic perturbation for thermoacoustic analysis. A continuation approach is employed to conduct the bifurcation analysis and capture the nonlinear behaviour inherent in the system. Unlike the conventional approach by the Galerkin method, the acoustic equations are originally discretized using the Method of Lines (MOL to build up a dynamic system. The model is first validated and shown to yield good predictions with available experimental data. Influences of multiple heat sources, time delay, and heat release distribution are then studied to reveal the extensive nonlinear characteristics involved in the case of a distributed heat source. It is found that distributed heat source plays an important role in determining the stability of a thermoacoustic system.

  17. Performance improvement of air source heat pump by using gas-injected rotary compressor

    Science.gov (United States)

    Wang, B. L.; Liu, X. R.; Ding, Y. C.; Shi, W. X.

    2017-08-01

    Rotary compressor is most widely used in small capacity refrigeration and heat pump systems. For the air source heat pump, the heating capacity and the COP will be obviously degraded when it is utilized in low temperature ambient. Gas injection is an effective method to enhance its performance under those situations, which has been well applied in air source heat pump with scroll compressor. However, the development of the gas injection technology in rotary compressor is relatively slow due to limited performance improvement. In this research, the essential reason constraining the improvement of the gas injection on the rotary compressor and its heat pump system is identified. Two new injection structures for rotary compressors has been put forward to overcome the drawback of traditional injection structures. Based on a verified numerical model, the thermodynamic performance of air source heat pumps with the new gas-injected rotary compressor are investigated. The results indicate that, compared to the air source heat pump with the traditional gas injected rotary compressor, the new injection structures both can enhance heating capacity and COP of the air source heat pump obviously.

  18. Evaluation of water source heat pumps for the Juneau, Alaska Area

    Energy Technology Data Exchange (ETDEWEB)

    Jacobsen, J.J.; King, J.C.; Eisenhauer, J.L.; Gibson, C.I.

    1980-07-01

    The purposes of this project were to evaluate the technical and economic feasibility of water source heat pumps (WSHP) for use in Juneau, Alaska and to identify potential demonstration projects to verify their feasibility. Information is included on the design, cost, and availability of heat pumps, possible use of seawater as a heat source, heating costs with WSHP and conventional space heating systems, and life cycle costs for WSHP-based heating systems. The results showed that WSHP's are technically viable in the Juneau area, proper installation and maintenance is imperative to prevent equipment failures, use of WSHP would save fuel oil but increase electric power consumption. Life cycle costs for WSHP's are about 8% above that for electric resistance heating systems, and a field demonstration program to verify these results should be conducted. (LCL)

  19. Identification of radiogenic heat source distribution in the crust: A variational approach

    Indian Academy of Sciences (India)

    R N Singh; Ajay Manglik

    2000-04-01

    Radiogenic heat sources present in the continental crust contribute significantly to the total surface heat flow and temperature distribution in the crust. Various modelsforthe depth distribution of radiogenic sources have been proposed. Among these modelsthe exponential model has been shown to be an optimal, smooth model through the variational approach applied to the heat conduction equation. In the present work, a two-layered model of the crust is considered and heat transport by advection is included in the upper layer. The heat transport in the lower layer is by conduction only. Application of variational principle determines the nature of the radiogenic source distribution in both the layers. The resultsthus obtained indicate a radiogenic source distribution which is more complex than a simple exponential model.

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

    Directory of Open Access Journals (Sweden)

    Xiang Gou

    2016-12-01

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

  1. Quantifying Systemic Efficiency using Exergy and Energy Analysis for Ground Source Heat Pumps: Domestic Space Conditioning and Water Heating Applications.

    Energy Technology Data Exchange (ETDEWEB)

    Ally, Moonis Raza [ORNL; Baxter, Van D [ORNL; Gehl, Anthony C [ORNL; Munk, Jeffrey D [ORNL

    2017-01-01

    Although air temperatures over land surfaces show wide seasonal and daily variations, the ground, approximately 10 meters below the earth s surface, remains relatively stable in temperature thereby serving as an energy source or sink. Ground source heat pumps can heat, cool, and supply homes with hot water efficiently by utilizing the earth s renewable and essentially inexhaustible energy resources, saving fossil fuels, reducing greenhouse gas emissions, and lowering the environmental footprint. In this paper, evidence is shown that ground source heat pumps can provide up to 79%-87% of domestic hot water energy needs, and up to 77% of space heating needs with the ground s thermal energy resources. The case refers to a 12-month study conducted at a 253 m2 research house located in Oak Ridge, Tennessee, 36.01 N 84.26 W in a mixed-humid climate with HDD of 2218 C-days and CDD of 723 C-days under simulated occupancy conditions. A single 94.5m vertical bore interfaced the heat pump with the ground. The research shows that this technology is capable of achieving US DOE targets of 25 % and 35% energy savings in HVAC, and in water heating, respectively by 2030. It is also a viable technology to meet greenhouse gas target emissions under the IECC 2012 Standard, as well as the European Union (EU) 2020 targets of using renewable energy resources. The paper quantifies systemic efficiencies using Exergy analysis of the major components, clearly pointing areas for further improvement.

  2. Cassini RTG Program monthly technical progress report, July 28--August 24, 1997

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-09-24

    The technical progress achieved during this period is described. This report is organized by program task structure: (1) spacecraft and integration liaison; (2) engineering support; (3) safety; (4) qualified unicouple production; (5) ETG fabrication, assembly, and test; (6) ground support equipment (GSE); (7) RTG shipping and launch support; (8) designs, reviews, and mission applications; (9) project management, quality assurance, reliability, contract changes, CAGO acquisition (operating funds), and CAGO maintenance and repair; and (10) CAGO acquisition (capital funds).

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1995-09-01

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

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

    Directory of Open Access Journals (Sweden)

    Ahmed W. Mustava

    2013-04-01

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

  5. Maximum work for Carnot-like heat engines with infinite heat source

    CERN Document Server

    Long, Rui

    2014-01-01

    An analysis of efficiency and its bounds at maximum work output for Carnot-like heat engines is conducted. The heat transfer processes are described by the linear law with time-dependent heat conductance. The upper bound of efficiency is found to be the CA efficiency,and is independent of the time duration completing each process and the time-dependent conductance. We prove that even the working medium exchanges heat sufficiently with the heat reservoirs, the work which could be extracted is finite and limited. The optimal temperature profiles in the heat exchanging processes are also analyzed. When the dimensionless contact times satisfy certain relations,the endoreversible model is recovered.

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

    DEFF Research Database (Denmark)

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

    2016-01-01

    . In long periods with high level of irradiance several modules were charged in parallel due to the limited heat exchange capacity of the integrated heat exchanger of the modules. After the modules were heated to more than 80° C they were set to passively cool down. Modules reached 30 °C in a period......A latent heat storage based on the phase change material Sodium Acetate Trihydrate (SAT) has been tested as part of a demonstration system. The full heat storage consisted of 4 individual modules each containing about 200 kg of sodium acetate trihydrate with different additives. The aim...... was to actively utilize the ability of the material to supercool to obtain long storage periods. The modules were charged with solar heat supplied by 22.4 m2 evacuated tubular collectors. The investigation showed that it was possible to fully charge one module within a period of 270 minutes with clear skies...

  7. Field Investigation of an Air-Source Cold Climate Heat Pump

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Bo [ORNL; Abdelaziz, Omar [ORNL; Rice, C Keith [ORNL; Baxter, Van D [ORNL

    2017-01-01

    In the U.S., there are approximately 2.6 million dwellings that use electricity for heating in cold and very cold regions with an annual energy consumption of 0.16 quads (0.17 EJ). A high performance cold climate heat pump (CCHP) would result in significant savings over current technologies (greater than 60% compared to electric resistance heating). We developed an air-source cold climate heat pump, which uses tandem compressors, with a single compressor rated for the building design cooling load, and running two compressors to provide, at -13 F (-25 C), 75% of rated heating capacity. The tandem compressors were optimized for heating operation and are able to tolerate discharge temperatures up to 280 F (138 C). A field investigation was conducted in the winter of 2015, in an occupied home in Ohio, USA. During the heating season, the seasonal COP was measured at 3.16, and the heat pump was able to operate down to -13 F (-25 C) and eliminate resistance heat use. The heat pump maintained an acceptable comfort level throughout the heating season. In comparison to a previous single-speed heat pump in the home, the CCHP demonstrated more than 40% energy savings in the peak heating load month. This paper illustrates the measured field performance, including compressor run time, frost/defrosting operations, distributions of building heating load and capacity delivery, comfort level, field measured COPs, etc.

  8. Federal Technology Alert: Ground-Source Heat Pumps Applied to Federal Facilities--Second Edition

    Energy Technology Data Exchange (ETDEWEB)

    Hadley, Donald L.

    2001-03-01

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

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

    DEFF Research Database (Denmark)

    Dominkovic, Dominik Franjo

    2016-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Ileana Blanco

    2013-09-01

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

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

    DEFF Research Database (Denmark)

    Dominkovic, Dominik Franjo

    2016-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Mirzaei Hooshyar

    2015-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Urbancl Danijela

    2016-01-01

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

  14. Efficiency of Vertical Geothermal Heat Exchangers in the Ground Source Heat Pump System

    Institute of Scientific and Technical Information of China (English)

    Heyi Zeng; Nairen Diao; Zhaohong Fang

    2003-01-01

    Taking the fluid temperature distribution along the borehole depth into account, a new quasi-three-dimensional model for vertical ground heat exchangers has been established, which provides a better understanding of the heat transfer processes in the geothermal heat exchangers. On this basis the efficiency of the borehole has been defined and its analytical expression derived. Comparison with the previous two-dimensional model shows that the quasi-three-dimensional model is more rational and more accurate to depict the practical feature of the conduction of geothermal heat exchanger, and the efficiency notion can be easily used to determine the inlet and outlet temperature of the circulating fluid inside the heat exchanger.

  15. Multi-Bed Multi-Stage Adsorption Refrigeration Cycle-Reducing Driving Heat Source Temperature

    Science.gov (United States)

    Alam, K. C. Amanul; Akahira, Akira; Hamamoto, Yoshinori; Akisawa, Atsushi; Kashiwagi, Takao; Saha, Bidyut Baran; Koyama, Shigeru; Ng, Kim Choon; Chua, Hui Tong

    The study aims at designing a multi-bed multi-stage adsorption chiller that can be driven by waste heat at near ambient temperature. The chiller is designed such a way that it can be switched into different modes depending on the driving heat source temperature. Stage regeneration techniques have been applied to operate the chiller by relatively low temperature heat source. Driving heat source temperature is validated by simulated data and the performances obtained from different modes are compared. In terms of COP (Coefficient of performance),the chiller shows best performance in conventional single-stage mode for driving heat source temperature greater than 60°C, two stage mode for driving source temperature between 42 and 60°C,in three-stage mode for driving source temperature less than 42°C. In terms of cooling capacity, it shows the best performance in single-stage mode for heat source temperature greater than 70°C. The mass recovery process in single-stage mode is also examined. It is seen that the mass recovery process improve cooling capacity significantly, specially for the low regenerating temperature region.

  16. Buoyancy-Driven Radiative Unsteady Magnetohydrodynamic Heat Transfer over a Stretching Sheet with non-Uniform Heat Source/sink

    Directory of Open Access Journals (Sweden)

    Dulal Pal

    2016-01-01

    Full Text Available In the present study an unsteady mixed convection boundary layer flow of an electrically conduct- ing fluid over an stretching permeable sheet in the presence of transverse magnetic field, thermal radiation and non-uniform heat source/sink effects is investigated. The unsteadiness in the flow and temperature fields is due to the time-dependent nature of the stretching velocity and the surface temperature. Both opposing and assisting flows are considered. The dimensionless governing or- dinary non-linear differential equations are solved numerically by applying shooting method using Runge-Kutta-Fehlberg method. The effects of unsteadiness parameter, buoyancy parameter, thermal radiation, Eckert number, Prandtl number and non-uniform heat source/sink parameter on the flow and heat transfer characteristics are thoroughly examined. Comparisons of the present results with previously published results for the steady case are found to be excellent.

  17. Nanofluid Flow past an Unsteady Permeable Shrinking Sheet with Heat Source or Sink and Newtonian Heating in a Porous Medium

    Directory of Open Access Journals (Sweden)

    M.Lavanya

    2016-02-01

    Full Text Available The consideration of nanofluids has been paid a good attention on the forced convection; the analysis focusing nanofluids in porous media are limited in literature. Thus, the use of nanofluids in porous media would be very much helpful in heat and mass transfer enhancement. In this paper, the influence of variable suction, Newtonian heating and heat source or sink heat and mass transfer over a permeable shrinking sheet embedded in a porous medium filled with a nanofluid is discussed in detail. The solutions of the nonlinear equations governing the velocɨty, temperature and concentration profiles are solved numerically using Runge-Kutta Gill procedure together with shooting method and graphical results for the resulting parameters are displayed and discussed. The influence of the physical parameters on skin-friction coefficient, local Nusselt number and local Sherwood number are shown in a tabulated form.

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

    Directory of Open Access Journals (Sweden)

    Nazari Mohsen

    2015-01-01

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

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

    Data.gov (United States)

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Juvonen, J.; Lapinlampi, T.

    2013-08-15

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

  1. Characterization of the Inductively Heated Plasma Source IPG6-B

    Science.gov (United States)

    Dropmann, Michael; Laufer, Rene; Herdrich, Georg; Matthews, Lorin; Hyde, Truell

    2014-10-01

    In close collaboration between the Center for Astrophysics, Space Physics and Engineering Research (CASPER) at Baylor University, Texas, and the Institute of Space Systems (IRS) at the University of Stuttgart, Germany, two plasma facilities have been established using the Inductively heated Plasma Generator 6 (IPG6). The facility at Baylor University (IPG6-B) works at a frequency of 13.56 MHz and a maximum power of 15 kW. A vacuum pump of 160 m3/h in combination with a butterfly valve allows pressure control over a wide range. Intended fields of research include basic investigation into thermo-chemistry and plasma radiation, space plasma environments and high heat fluxes e.g. those found in fusion devices or during atmospheric re-entry of spacecraft. After moving the IPG6-B facility to the Baylor Research and Innovation Collaborative (BRIC) it was placed back into operation during the summer of 2014. Initial characterization in the new lab, using a heat flux probe, Pitot probe and cavity calorimeter, has been conducted for Air, Argon and Helium. The results of this characterization are presented.

  2. Water source heat pumps for greenhouse soil cooling. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Spieser, H.

    1987-06-01

    In an attempt to diversify and grow flowers which are in high demand, growers are looking to produce certain exotic flowers which require unique growing conditions. One example is the Alstroemerias also knwon as the Peruvian Lily. If the plants are grown continuously at about 12-15/sup 0/C soil temperature, the plant will continue to flower regardless of air temperature and photoriod. These latter two factors are considered secondary to the importance of cool soil temperatures. Alstroemeria production is still relatively new to the greenhouse industry. Some controversy still exists as to the direct benefits of planned soil cooling. This project was set up to evaluate a mechanical soil cooling system for continuous year round Alstroemeria production. A heat pump soil cooling system was installed in two greenhouses each with dimensions of 16 m by 61 m. Combined these greenhouses have a growing area of 1952 m/sup 2/. These greenhouses are older wooden greenhouses, covered by double poly, air-inflated glazing. This system worked very well, maintaining the soil temperature at the proper levels throughout the spring and summer months. During the rest of the year the soil cooling system is used less intensely. During winter months when soil cooling is not required, the heat pumps provide base load heating to the greenhouse through fan forced unit heaters.

  3. Magnetic pumping as a source of particle heating

    Science.gov (United States)

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

    2016-10-01

    Magnetic pumping is a means of heating plasmas for both fusion and astrophysical applications. This study presents a generalized model, related to the compressional pumping model Fisk & Gloeckler applied to the solar wind (2006). Unlike previous models, this model includes diffusion of the anisotropic features which develop in velocity space, thereby allowing energy to be transferred to the particles directly from the turbulence. By using various orderings, the drift kinetic equation can be reduced to a more general form of Parker's equation with an anisotropic distribution function. Through expansions in both pitch angle and in space, it can be shown that this equation has power law solutions and results in an overall heating of the plasma. This form of heating is related to transit-time damping. Kinetic simulations were performed to test the theoretical model and explore regimes where spatial and velocity diffusion are of the same order of importance, regimes not easily available to analytical calculations. These simulations appear to confirm the pumping model in the appropriate limits.

  4. National Certification Standard for Ground Source Heat Pump Personnel

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-07-31

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

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

    Directory of Open Access Journals (Sweden)

    Xin Wen Zhang

    2015-07-01

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

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

    NARCIS (Netherlands)

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

    2017-01-01

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

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

    DEFF Research Database (Denmark)

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

    2012-01-01

    prices. A significant part of this challenge may be dealt with in the way space heating, space cooling, and domestic hot water production which is provided to residential and commercial buildings. Air source heat pumps (ASHP) are widely used conversion technologies for providing building thermal energy...

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

    NARCIS (Netherlands)

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

    2017-01-01

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

  9. Technology Solutions Case Study: Ground Source Heat Pump Research, TaC Studios Residence, Atlanta, Georigia

    Energy Technology Data Exchange (ETDEWEB)

    None

    2014-09-01

    This case study describes the construction of a new test home that demonstrates current best practices for the mixed-humid climate, including a high performance ground source heat pump for heating and cooling, a building envelope featuring advanced air sealing details and low-density spray foam insulation, and glazing that exceeds ENERGY STAR requirements.

  10. Using Ground Source Heat Pumps for Renewable Energy

    OpenAIRE

    Xhevat BERISHA

    2017-01-01

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

  11. An Electrothermal Plasma Source Developed for Simulation of Transient Heat Loads in Future Large Fusion Devices

    Science.gov (United States)

    Gebhart, Trey; Baylor, Larry; Winfrey, Leigh

    2016-10-01

    The realization of fusion energy requires materials that can withstand high heat and particle fluxes at the plasma material interface. In this work, an electrothermal (ET) plasma source has been designed as a possible transient heat flux source for a linear plasma material interaction device. An ET plasma source operates in the ablative arc regime, which is driven by a DC capacitive discharge. The current travels through the 4mm bore of a boron nitride liner and subsequently ablates and ionizes the liner material. This results in a high density plasma with a large unidirectional bulk flow out of the source exit. The pulse length for the ET source has been optimized using a pulse forming network to have a duration of 1ms at full-width half maximum. The peak currents and maximum source energies seen in this system are 2kA and 5kJ. The goal of this work is to show that the ET source produces electron densities and heat fluxes that are comparable to transient events in future large magnetic confinement fusion devices. Heat flux, plasma temperature, and plasma density were determined for each test shot using infrared imaging and optical spectroscopy techniques. This work will compare the ET source output (heat flux, temperature, and density) with and without an applied magnetic field. Research sponsored by the Laboratory Directed Research and Development Program of Oak Ridge National Laboratory, managed by UT-Battelle, LLC, for the U. S. Department of Energy.

  12. Ablation Properties of the Carbon-Based Composites Used in Artificial Heat Source Under Fire Accident

    Institute of Scientific and Technical Information of China (English)

    TANG; Xian; HUANG; Jin-ming; ZHOU; Shao-jian; LUO; Zhi-fu

    2012-01-01

    <正>The ablation properties of the carbon-based composites used in artificial heat source under fire accident were investigated by the arc heater. In this work, we tested the carbon-based composites referring to Fig. 1. Their linear/mass ablation ratio and ablation morphologies were studied. The results showed that the carbon-based composites used in artificial heat source behaved well

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

    DEFF Research Database (Denmark)

    Heiselberg, Per; Nielsen, Peter V.

    1988-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Jukka Yrjölä

    2015-08-01

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

  15. Electron cyclotron resonance heating by magnetic filter field in a negative hydrogen ion source

    Energy Technology Data Exchange (ETDEWEB)

    Kim, June Young, E-mail: beacoolguy@snu.ac.kr; Cho, Won-Hwi; Dang, Jeong-Jeung; Chung, Kyoung-Jae, E-mail: jkjlsh1@snu.ac.kr; Hwang, Y. S. [Department of Nuclear Engineering, Seoul National University, Seoul 151-742 (Korea, Republic of)

    2016-02-15

    The influence of magnetic filter field on plasma properties in the heating region has been investigated in a planar-type inductively coupled radio-frequency (RF) H{sup −} ion source. Besides filtering high energy electrons near the extraction region, the magnetic filter field is clearly observed to increase the electron temperature in the heating region at low pressure discharge. With increasing the operating pressure, enhancement of electron temperature in the heating region is reduced. The possibility of electron cyclotron resonance (ECR) heating in the heating region due to stray magnetic field generated by a filter magnet located at the extraction region is examined. It is found that ECR heating by RF wave field in the discharge region, where the strength of an axial magnetic field is approximately ∼4.8 G, can effectively heat low energy electrons. Depletion of low energy electrons in the electron energy distribution function measured at the heating region supports the occurrence of ECR heating. The present study suggests that addition of axial magnetic field as small as several G by an external electromagnet or permanent magnets can greatly increase the generation of highly ro-vibrationally excited hydrogen molecules in the heating region, thus improving the performance of H{sup −} ion generation in volume-produced negative hydrogen ion sources.

  16. On the Design and Response of Domestic Ground-Source Heat Pumps in the UK

    Directory of Open Access Journals (Sweden)

    Chris Underwood

    2014-07-01

    Full Text Available The design and response of ground source heat pumps coupled to vertical closed loop arrays in UK domestic applications are investigated in this article. Two typical UK house types are selected as the vehicle for the study and a detailed dynamic thermal modelling method is used to arrive at time-series heating demands for the two houses. A new empirical heat pump model is derived using experimental data taking into account the deteriorating performance of the heat pump during periods of light load. The heat pump model is incorporated into an existing numerical ground model and completed with a classical effectiveness type heat exchange model of the closed loop array. The model is used to analyse array sizing and performance over an extended time period, as well as sensitivity of the design to soil conductivity and borehole heat exchanger resistance and sensitivity to over-sizing and part-load behavior of the heat pump. Results show that the UK’s standard for ground source design (the Microgeneration Certification Scheme may lead to under-estimated array sizes and that heating system over-sizing and deleterious part-load heat pump performance can add up to 20% to the electrical consumption of these systems.

  17. Numerical Prediction of Performance of Water Type Stirling Engine Considering Heat Exchange with Heat Sources

    Science.gov (United States)

    Yamaguchi, Yoshiyuki; Higuchi, Tetsuya

    Two different analytical models were developed on water type Stirling engine. One is the resonance model which qualitatively clarifies the relationship between performance and resonance tube length, and the other is the heat transfer model considering heat transfer between working gas and the tube walls of heating and cooling units. These analyses and experiments were carried out changing the resonance tube length variously, then it was confirmed that the resonance tube length which maximizes the water column amplitude of the power piston agrees well and the oscillations of water columns at that resonance tube length also agrees. In addition, a series of analysis using the heat transfer model was carried out with changing cross sectional area of the resonance tube, loss factors of the elbows, heat transfer area of heating and cooling unit, and pressure of working gas. By this numerical investigation, the effect on the resonance tube length and the work at the length in which these parameters maximize the amplitude of power piston water column was clarified.

  18. Hourly Calculation Method of Air Source Heat Pump Behavior

    Directory of Open Access Journals (Sweden)

    Ludovico Danza

    2016-04-01

    Full Text Available The paper describes an hourly simplified model for the evaluation of the energy performance of heat pumps in cooling mode maintaining a high accuracy and low computational cost. This approach differs from the methods used for the assessment of the overall energy consumption of the building, normally placed in the so-called white or black box models, where the transient conduction equation is deterministically and stochastically solved, respectively. The present method wants to be the expression of the grey box model, taking place between the previous approaches. The building envelope is defined using a building thermal model realized with a 3 Resistance 1 Capacitance (3R1C thermal network based on the solution of the lumped capacitance method. The simplified model evaluates the energy efficiency ratio (EER of a heat pump through the determination of the hourly second law efficiency of a reversed Carnot cycle. The results of the simplified method were finally compared with those provided by EnergyPlus, a dynamic building energy simulation program, and those collected from an outdoor test cell in real working conditions. The results are presented in temperatures and energy consumptions profiles and are validated using the Bland-Altman test.

  19. Nanofluid flow and forced convection heat transfer over a stretching surface considering heat source

    Science.gov (United States)

    Mohammadpour, M.; Valipour, P.; Shambooli, M.; Ayani, M.; Mirparizi, M.

    2015-07-01

    In this paper, magnetic field effects on the forced convection flow of a nanofluid over a stretching surface in the presence of heat generation/absorption are studied. The equations of continuity, momentum and energy are transformed into ordinary differential equations and solved numerically using the fourth-order Runge-Kutta integration scheme featuring the shooting technique. Different types of nanoparticles as copper (Cu), silver (Ag), alumina (Al2O3) and titania (TiO2) with water as their base fluid has been considered. The influence of significant parameters, such as magnetic parameter, volume fraction of the nanoparticles, heat generation/absorption parameter, velocity ratio parameter and temperature index parameter on the flow and heat transfer characteristics are discussed. The results show that the values of temperature profiles increase with increasing heat generation/absorption and volume fraction of the nanoparticles but they decrease with increasing velocity ratio parameter and temperature index parameter. Also, it can be found that selecting silver as nanoparticle leads to the highest heat transfer enhancement.

  20. Research Progress on the Problem of Fluid, Heat and Energy Distribution near the Earthquake Source Area

    Institute of Scientific and Technical Information of China (English)

    Yan Rui; Jiang Changsheng; Shao Zhigang; Zhou Longquan; Li Yingchun

    2011-01-01

    As the basic problems in seismology, fluid, heat and energy distribution near earthquake sources during earthquake generation have been the leading subjects of concern to seismologists. Currently, more and more research shows fluid around earthquake source areas, which plays an important role in the process of earthquake preparation and generation. However, there is considerable controversy over the source of fluid in the deep crust. As for the problem of heat around earthquake source areas, different models have been proposed to explain the stress heat flow paradox. Among them, the dynamic weakening model has been thought to be the key to solving the heat flow paradox issue. After large earthquakes, energy distribution is directly related to friction heat. It is of timely and important practical significance to immediately implement deep drilling in-site surveying to gain understanding of fluid, friction heat and energy distribution during earthquake generation. The latest international progress in fluid, heat and energy distribution research has been reviewed in this paper which will bring important inspiration for the understanding of earthquake preparation and occurrence.

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

    Science.gov (United States)

    Qin, Zenghu; Tong, Mingwei; Kun, Lin

    2012-01-01

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

  2. Co-control of source and heat: the generation and distribution of hydrocarbons controlled by source rocks and heat%源热共控论

    Institute of Scientific and Technical Information of China (English)

    张功成

    2012-01-01

    Hydrocarbon generation is co-controlled by source rocks and heat, which are internal and external controlling factors, respectively. The combination of these two factors controls the generation, scale, phase (oil or gas) behavior and regional distribution pattern of hydrocarbons. The controlling factors of potential hydrocarbon source rocks include the type, abundance and scale of source rocks. Their heat field consists of hot, warm and cold models and there are 3 types of thermal evolution, I. E. Temperature-increasing, temperature-decreasing and complex multi-episode types. In potential hydrocarbon-generating sags, there are 4 kinds of combination between source rocks and heat, namely sufficient source and heat, sufficient source but deficient heat, deficient source but sufficient heat, and deficient source and heat. The sufficient source and heat combination can form hydrocarbon-generating sags including hydrocarbon-prolific or hydrocarbon-bearing sags, and the sufficient source but deficient heat combination or the deficient source but sufficient heat combination can also form hydrocarbon-generating or hydrocarbon-prolific sags on condition that source and heat can complement each other, while the deficient source and heat combination can not form hydrocarbon-bearing sags. In a hydrocarbon province co-controlled by source and heat, oil, gas or oil-gas layers generally have a spatially ordered distribution, which is characterized vertically by a lower oil and upper gas pattern or a lower gas and upper oil pattern, and laterally hy an inner and outer belt pattern, an inner and outer circle pattern, or a zoning pattern. The scale of hydrocarbon reserves in this hydrocarbon province depends mainly on the development of the sufficient source and heat sag, and hydrocarbon-bearing basins in China can be roughly classified into extra-prolific, prolific, medium, small and poor hydrocarbon-bearing basins.%源热共控油气形成,潜在烃源岩是油气形成的内因,

  3. The Possibility to use a Nuclear Power Plant as a Source of Electrical Energy and Heat

    Directory of Open Access Journals (Sweden)

    Tomasz Minkiewicz

    2014-09-01

    Full Text Available In this article issues concernig the possibility of nuclear power plant (NPP operation also as a source of heat, which means combined heat and power production, have been described. CHP work is possible and profitable only in those areas where high thermal power demand occurs, which means near city agglomerations such as Warsaw or the Tri-City. Two levels of thermal power delivered to the heating system have been considered. Preliminary technical and economic studies regarding NPP location by Żarnowiec Lake have confirmed the NPP potential to work as a primary source of heat in the heating network system, which would feed the regions of Wejherowo and Gdynia.

  4. Behavioral observations and operant procedures using microwaves as a heat source for young chicks

    Energy Technology Data Exchange (ETDEWEB)

    Morrison, W.D.; McMillan, I.; Bate, L.A.; Otten, L.; Pei, D.C.

    1986-08-01

    Four trials, using operant conditioning procedures, were conducted to study the response of chicks, housed at 16 C, to microwave or infrared heat. Microwave power density was 26 mW/cm2 in Trial 1, 13 mW/cm2 in Trial 2, and 10 mW/cm2 in Trials 3 and 4. Chicks voluntarily demanded between 28 and 63% as much heat (min heat/hr) from microwave source as from infrared source at all power densities. There was no correlation, however, between the ratio of heat demanded and the power density used. There were no significant differences in growth between infrared- or microwave-heated chicks. It is evident from these studies that 8-day-old broiler chicks are capable of associating the performance of a task with a thermal reward provided by the microwaves. They are also able to utilize these microwaves through operant conditioning without any visible detrimental effect to their health or behavior.

  5. Impact factors on the long-term sustainability of Borehole Heat Exchanger coupled Ground Source Heat Pump System

    Science.gov (United States)

    Shao, Haibing; Hein, Philipp; Görke, Uwe-Jens; Bucher, Anke; Kolditz, Olaf

    2016-04-01

    In recent years, Ground Source Heat Pump System (GSHPS) has been recognized as an efficient technology to utilize shallow geothermal energy. Along with its wide application, some GSHPS are experiencing a gradual decrease in Borehole Heat Exchanger (BHE) outflow temperatures and thus have to be turned off after couple of years' operation. A comprehensive numerical investigation was then performed to model the flow and heat transport processes in and around the BHE, together with the dynamic change of heat pump efficiency. The model parameters were based on the soil temperature and surface weather condition in the Leipzig area. Different scenarios were modelled for a service life of 30 years, to reveal the evolution of BHE outflow and surrounding soil temperatures. It is found that lateral groundwater flow and using BHE for cooling will be beneficial to the energy recovery, along with the efficiency improvement of the heat pump. In comparison to other factors, the soil heat capacity and thermal conductivity are considered to have minor impact on the long-term sustainability of the system. Furthermore, the application of thermally enhanced grout material will improve the sustainability and efficiency. In contrast, it is very likely that undersized systems and improper grouting are the causes of strong system degradation.

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

    Science.gov (United States)

    Strumpf, H. J.

    1978-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-11-15

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

  8. COMPARATIVE STUDY AMONG HYBRID GROUND SOURCE HEAT PUMP SYSTEM, COMPLETE GROUND SOURCE HEAT PUMP AND CONVENTIONAL HVAC SYSTEM

    Energy Technology Data Exchange (ETDEWEB)

    Jiang Zhu; Yong X. Tao

    2011-11-01

    In this paper, a hotel with hybrid geothermal heat pump system (HyGSHP) in the Pensacola is selected and simulated by the transient simulation software package TRNSYS [1]. To verify the simulation results, the validations are conducted by using the monthly average entering water temperature, monthly facility consumption data, and etc. And three types of HVAC systems are compared based on the same building model and HVAC system capacity. The results are presented to show the advantages and disadvantages of HyGSHP compared with the other two systems in terms of energy consumptions, life cycle cost analysis.

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

    Directory of Open Access Journals (Sweden)

    Reddy Meenakshi R.

    2012-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2017-04-15

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

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

    DEFF Research Database (Denmark)

    Mathiesen, Brian Vad; Lund, Henrik

    2005-01-01

    This paper presents the methodology and results of analysing the use of different energy storage technologies in the task of integration of fluctuating renewable energy sources (RES) into the electricity supply. The analysis is done on the complete electricity system including renewable energy...... sources as well as power plants and CHP (Combined heat and power production). Emphasis is put on the need for ancillary services. Devices to store electricity as well as devices to store heat can be used to help the integration of fluctuating sources. Electricity storage technologies can be used...

  12. Development of the data base for a degradation model of a selenide RTG. [Radioisotope Thermoelectric Generator

    Science.gov (United States)

    Stapfer, G.; Truscello, V. C.

    1977-01-01

    The paper is concerned with the evaluation of the materials used in a selenide radioisotope thermoelectric generator (RTG). These materials are composed of n-type gadolinium selenide and n-type copper selenide. A three-fold evaluation approach is being used: (1) the study of the rate of change of the thermal conductivity of the material, (2) the investigation of the long-term stability of the material's Seebeck voltage and electrical resistivity under current and temperature gradient conditions, and (3) determination of the physical behavior and compatibility of the material with surrounding insulation at elevated temperatures. Programmatically, the third category of characteristic evaluation is being emphasized.

  13. Location of energy source for coronal heating on the photosphere

    Science.gov (United States)

    Hong, Zhen-Xiang; Yang, Xu; Wang, Ya; Ji, Kai-Fan; Ji, Hai-Sheng; Cao, Wen-Da

    2017-02-01

    It is reported that ultra-fine dynamic ejections along magnetic loops of an active region originate from intergranular lanes and they are associated with subsequent heating in the corona. As continuing work, we analyze the same set of data but focus on a quiet region and the overlying EUV/UV emission as observed by the Atmospheric Imaging Assembly (AIA) on board Solar Dynamics Observatory (SDO). We find that there appear to be dark patches scattered across the quiet region and the dark patches always stay along intergranular lanes. Over the dark patches, the average UV/EUV emission at 131, 171, 304 and 1600 Å (middle temperature) is more intense than that of other regions and EUV brightness is negatively correlated with 10830 Å intensity, though, such a trend does not exist for high temperature lines at 94, 193, 211 and 335 Å. For the same quiet region, where both TiO 7057 Å broad band images and 10830 Å filtergrams are available, contours for the darkest lane areas on TiO images and dark patches on 10830 Å filtergrams frequently differ in space. The results suggest that the dark patches do not simply reflect the areas with the darkest lanes but are associated with a kind of enhanced absorption (EA) at 10830 Å. A strict definition for EA with narrow band 10830 Å filtergrams is found to be difficult. In this paper, we define enhanced absorption patches (EAPs) of a quiet region as the areas where emission is less than ∼90% of the mean intensity of the region. The value is equivalent to the average intensity along thin dark loops connecting two moss regions of the active region. A more strict definition for EAPs, say 88%, gives even more intense UV/EUV emission over those in the middle temperature range. The results provide further observational evidence that energy for heating the upper solar atmosphere comes from the intergranular lane area where the magnetic field is constantly brought in by convection motion in granules.

  14. Investigation on A Ground Source Heat Pump System Integrated With Renewable Sources

    OpenAIRE

    Qian, Defeng; Niu, Fuxin; Kavanaugh, Steven; O'Neill, Zheng

    2016-01-01

    Buildings consumed 40% of the energy and represented 40% of the carbon emissions in the United States. This is more than any other sector of the U.S. economy, including transportation and industry. About 24% of all energy used in the nation is for space heating, cooling and water heating in buildings. Enhancing building efficiency represents one of the easiest, most immediate and most cost effective ways to reduce carbon emissions. One of energy efficient and environment friendly technologies...

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

    Science.gov (United States)

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

    2015-12-01

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

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

    Directory of Open Access Journals (Sweden)

    Wajs Jan

    2015-12-01

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

  17. High Performance Cascading Adsorption Refrigeration Cycle with Internal Heat Recovery Driven by a Low Grade Heat Source Temperature

    Directory of Open Access Journals (Sweden)

    Yuki Ueda

    2009-11-01

    Full Text Available This paper presents the performance of an advanced cascading adsorption cycle that utilizes a driven heat source temperature between 90–130 ºC. The cycle consists of four beds that contain silica gel as an adsorber fill. Two of the beds work in a single stage cycle that is driven by an external heat source, while the other two beds work in a mass recovery cycle that is driven by waste heat of sensible and adsorption heat of the high temperature cycle. The performances, in terms of the coefficient of performance (COP and the specific cooling power (SCP, are compared with conventional cascading-without-mass-recovery and single-stage cycles. The paper also presents the effect of the adsorbent mass on performance. The results show that the proposed cycle with mass recovery produces as high of a COP as the COP that is produced by the conventional cascading cycle. However, it produces a lower SCP than that of the single-stage cycle.

  18. An inductively heated hot cavity catcher laser ion source

    CERN Document Server

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

    2015-01-01

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

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

    DEFF Research Database (Denmark)

    Nguyen, Chan; Veje, Christian

    2011-01-01

    A transcritical carbon dioxide (CO2) Rankine power cycle has been analyzed based on first and second law of thermodynamics. Detailed simulations using distributed models for the heat exchangers have been performed in order to develop the performance characteristics in terms of e.g., thermal effic...... conditions for the high side pressure. In addition the results underline that the investment cost for additional heat exchange components such as an internal heat exchanger may be unprofitable in the case where the heat source is free.......A transcritical carbon dioxide (CO2) Rankine power cycle has been analyzed based on first and second law of thermodynamics. Detailed simulations using distributed models for the heat exchangers have been performed in order to develop the performance characteristics in terms of e.g., thermal...... efficiency, exergetic efficiency and specific net power output. A generic cycle configuration has been used for analysis of a geothermal energy heat source. This model has been validated against similar calculations using industrial waste heat as the energy source. Calculations are done with fixed...

  20. Joule Heating, Particle Precipitation and Dynamical Heating as Possible Tidal Sources in the Antarctic Winter Lower Thermosphere

    Science.gov (United States)

    Fong, W.; Chu, X.; Lu, X.; Chen, C.; Yu, Z.; Fuller-Rowell, T. J.; Richmond, A. D.; Codrescu, M.

    2014-12-01

    Winter temperature tides observed by lidar at McMurdo (77.8°S, 166.7°E), Antarctica, show less than 3 K diurnal and semidiurnal tidal amplitude below 100 km. However, above 100 km, the diurnal and semidiurnal tidal amplitudes grow super-exponentially and can reach at least 15 K near 110 km, which are exceeding that of the freely propagating tides originating from the lower atmosphere. Such fast growth exists for all Kp index cases and diurnal amplitude increases to 15-30 K at 110 km with larger Kp indices corresponding to larger tidal amplitudes and faster growth rates. Combining with the slopes of diurnal tidal phases being steeper above 100 km, and the tidal phases barely changing with altitude from 100 to 106 km, it indicates that in-situ tidal sources may exist near or above 100 km. In this paper, we utilize the coupled thermosphere ionosphere plasmasphere electrodynamics (CTIPe) model to investigate possible sources/mechanisms that lead to the fast amplitude growth of tides in the polar winter region. Joule heating, particle precipitation, and dynamical heating are likely to be the dominant thermospheric tidal sources, according to CTIPe model. Interestingly, the CTIPe tidal amplitudes induced by these sources form a concentric pattern with its center located at the geomagnetic pole, implying that the geomagnetic activity may play an important role. Furthermore, dynamical heating, which includes adiabatic heating/cooling and vertical advection, is likely to be the explanation of the fast growth of diurnal tidal amplitudes even under quiet condition of geomagnetic activity as observed by lidar. We also found that the tides propagating from the lower atmosphere is a minor factor for the fast increase of thermospheric diurnal tides in Antarctica.

  1. 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.

  2. Curing of a bisphenol E based cyanate ester using magnetic nanoparticles as an internal heat source through induction heating.

    Science.gov (United States)

    Hubbard, Jeremiah W; Orange, François; Guinel, Maxime J-F; Guenthner, Andrew J; Mabry, Joseph M; Sahagun, Christopher M; Rinaldi, Carlos

    2013-11-13

    We report on the control of cyclotrimerization forming a polycyanurate polymer using magnetic iron oxide nanoparticles in an alternating-current (ac) field as an internal heat source, starting from a commercially available monomer. Magnetic nanoparticles were dispersed in the monomer and catalytic system using sonication, and the mixture was subjected to an alternating magnetic field, causing the magnetic nanoparticles to dissipate the energy of the magnetic field in the form of heat. Internal heating of the particle/monomer/catalyst system was sufficient to start and sustain the polymerization reaction, producing a cyanate ester network with conversion that compared favorably to polymerization through heating in a conventional laboratory oven. The two heating methods gave similar differential scanning calorimetry temperature profiles, conversion rates, and glass transition temperatures when using the same temperature profile. The ability of magnetic nanoparticles in an ac field to drive the curing reaction should allow for other reactions forming high-temperature thermosetting polymers and for innovative ways to process such polymers.

  3. Urban heat islands in the subsurface as sustainable source for geothermal energy

    Science.gov (United States)

    Menberg, Kathrin; Bayer, Peter; Blum, Philipp

    2014-05-01

    The urban heat island (UHI) is not a phenomenon that solely occurs in the atmosphere with increased air temperatures. We also observe it in the subsurface, and groundwater temperatures in shallow aquifers are strongly influenced by anthropogenic land surface alterations. Widespread thermal anomalies, which are triggered by various processes, such as increased ground surface temperatures (GST) and heat loss from buildings, can be found under many urban areas. With groundwater temperatures elevated by several degrees these aquifers represent large amounts of stored thermal energy. However, to exploit these attractive geothermal reservoirs efficiently and sustainably, the processes, which lead to the profound subsurface urban warming, need to be identified and quantified. In the current study, the spatial extension of the heat anomalies beneath several German cities, such as Berlin, Munich, Karlsruhe and Cologne, is scrutinized by mapping groundwater temperatures in a dense network of observation wells. With the high-resolved spatial distribution of groundwater temperatures, the dominant heat sources and important driving factors can be identified and incorporated into an analytical heat flux model. The annual anthropogenic heat input into the aquifer originating from several heat sources, such as increased GST, basements, sewage networks, district heating networks and reinjections of thermal waste water, is estimated by a Monte Carlo simulation for the cities of Cologne and Karlsruhe. All studied cities exhibit aquifers with significantly elevated temperatures, with the highest temperatures of up to 18°C prevailing in the densely built-up city centers. But also in suburban and industrial areas groundwater temperatures are several degrees above the rural background. The accumulated heat content in the urban aquifers can be estimated based on the thermal ground properties. This content is compared to the annual space heating demand in order to analyze the space

  4. Nucleotide Sequence of the blaRTG-2 (CARB-5) Gene and Phylogeny of a New Group of Carbenicillinases

    Science.gov (United States)

    Choury, Daniele; Szajnert, Marie-France; Joly-Guillou, Marie-Laure; Azibi, Kemal; Delpech, Marc; Paul, Gérard

    2000-01-01

    We determined the nucleotide sequence of the bla gene for the Acinetobacter calcoaceticus β-lactamase previously described as CARB-5. Alignment of the deduced amino acid sequence with those of known β-lactamases revealed that CARB-5 possesses an RTG triad in box VII, as described for the Proteus mirabilis GN79 enzyme, instead of the RSG consensus characteristic of the other carbenicillinases. Phylogenetic studies showed that these RTG enzymes constitute a new, separate group, possibly ancestors of the carbenicillinase family. PMID:10722515

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

    Directory of Open Access Journals (Sweden)

    Kai-Long Hsiao

    2010-01-01

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

  6. A theoretical estimation of the pre-breakdown-heating time in the underwater discharge acoustic source

    Institute of Scientific and Technical Information of China (English)

    Wang Yi-Bo; Wang Shang-Wu; Zeng Xin-Wu

    2012-01-01

    One of the common characteristics of the electrothermal breakdown in an underwater discharge acoustic source(UDAS)is the existence of a pre-breakdown-heating phase.In our experiment,two phenomena were observed:(1)the breakdown time that takes on high randomicity and obeys a "double-peak" stochastic distribution;(2)the higher salt concentration that reduces the residual voltage and causes 100% non-breakdown.The mechanism of electrothermal breakdown is analysed.To specify the end of the pre-breakdown-heating phase,a "border boiling" assumption is proposed,in which the breakdown time is assumed to be the time needed to heat the border water around the initial arc to 773 K.Based on this ‘border boiling' assumption,the numerical simulation is performed to evaluate the effects of two heating mechanisms:the Joule heating from the ionic current,and the radiation heating from the initial arc.The simulation results verify the theoretical explanations to these two experiment phenomena:(1)the stochastic distribution of the radius of the initial arc results in the randomicity of the breakdown time;(2)the difference in efficiency between the radiation heating and the Joule heating determines that,in the case of higher salt concentration,more energy will be consumed in the pre-breakdown-heating phase.

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

    Directory of Open Access Journals (Sweden)

    Jong-Keun Shin

    2013-05-01

    Full Text Available In the present study, a fuel cell driven ground source heat pump (GSHP system is applied in a community building and heat pump system performance is analyzed by computational methods. Conduction heat transfer between the brine pipe and ground is analyzed by TEACH code in order to predict the performance of the heat pump system. The predicted coefficient of performance (COP of the heat pump system and the energy cost were compared with the variation of the location of the objective building, the water saturation rate of the soil, and the driven powers of the heat pump system. Compared to the late-night electricity driven system, a significant reduction of energy cost can be accomplished by employing the fuel cell driven heat pump system. This is due to the low cost of electricity production of the fuel cell system and to the application of the recovered waste heat generated during the electricity production process to the heating of the community building.

  8. Thermodynamic inspection of concrete using a controlled heat source

    Science.gov (United States)

    Milne, James M.

    1990-10-01

    Concrete is not quite such a non-destructable material as many are led to believe. It can deteriorate with time due to changes in the chemistry, the effect of moisture penetration and the corrosion of reinforcing steel bars. Much of this damage occurs relatively close to the surface, sometimes revealed by discolourations or the presence of cracks and sometimes as spallation when the corrosion products of steel cause delamination of the near surface concrete. These effects may occur in good quality concrete but their severity and rapidity of onset may be enhanced by fabrication defects when aggregates may not be to specification or the packing conditions cause porosity. It may thus be months or even years afterwards that these defects come to light. As a consequence a new industry has been formed to inspect concrete structures which may include X-ray equipment, linac accelerators, gamma isotope sources, ultrasonics, radar and of course thermography. Each of these nethods will have their own particular attractive features and merits. But most of these activities tend to be used more as a "fire fighting" service than as one ensuring regular maintenance of critical structures or even as quality control of structures during building. Quite often it seems that Non-destructive Testing is turned into a litigation service for dissatisfied customers and thermography is no stranger to this topic. It is heartening to see that the ASTM organisation in the USA and British Standards are encouraging and developing suitable standards for the inspection of concrete by thermographic techniques.

  9. MUNICIPAL WASTEWATER AS AN SOURCE OF WASTE HEAT – CASE STUDY

    Directory of Open Access Journals (Sweden)

    Alina Żogała

    2016-09-01

    Full Text Available The paper describes the possibility of useing treated wastewater from municipal waste water treatment plant as a waste heat source. Presented and calculated theoretical possibilities of receiving heat takes into account the indirect and direct method. A variant case study was carried out on the example of municipal mechanical and biological wastewater treatment plant Ruptawa belonging to Jastrzębskie Przedsiębiorstwo Wodociągów i Kanalizacji (voivodship Silesia, Jastrzębie City.

  10. Parallel Operation Characteristics Analysis of Sewage Source Heat Pump Units in Winter

    Institute of Scientific and Technical Information of China (English)

    庄兆意; 张承虎; 王海燕; 孙德兴

    2010-01-01

    Sewage source heat pump unit operates under partial load most of the time, and study on the law of coefficient of performance (COP) of the unit varying with load ratio can provide basis for the heat pump units running in high efficiency. A mathematical model determining COP, evaporation temperature and condensation temperature of a single unit was proposed. Under the condition of uniform load distribution, the model was established according to different ways of bearing partial load with the same type multi...

  11. [Urban heat island effect based on urban heat island source and sink indices in Shenyang, Northeast China].

    Science.gov (United States)

    Li, Li-Guang; Xu, Shen-Lai; Wang, Hong-Bo; Zhao, Zi-Qi; Cai, Fu; Wu, Jin-Wen; Chen, Peng-Shi; Zhang, Yu-Shu

    2013-12-01

    Based on the remote images in 2001 and 2010, the source and sink areas of urban heat island (UHI) in Shenyang City, Northeast China were determined by GIS technique. The effect of urban regional landscape pattern on UHI effect was assessed with land surface temperature (LST), area rate index (CI) of the source and sink areas and intensity index (LI) of heat island. The results indicated that the land use type changed significantly from 2001 to 2010, which significantly changed the source and sink areas of UHI, especially in the second and third circle regions. The source and sink areas were 94.3% and 5.7% in the first circle region, 64.0% and 36.0% in the third circle region in 2001, while they were 93.4% and 6.6%, 70.2% and 29.8% in 2010, respectively. It suggested that the land use pattern extended by a round shape in Shenyang led to the corresponding UHI pattern. The LST in the study area tended to decrease from the first circle region to the third. The UHI intensity was characterized with a single center in 2001 and with several centers in 2010, and the grade of UHI intensity was in a decreasing trend from 2001 to 2010. The absolute value of CI increased from the first circle region to the third, and the L1 was close to 1, suggesting the change in land use pattern had no significant influence on UHI in Shenyang.

  12. Eigenvalue approach to fractional order generalized magneto-thermoelastic medium subjected to moving heat source

    Energy Technology Data Exchange (ETDEWEB)

    Abbas, Ibrahim A., E-mail: aabbas5@kau.edu.sa [Department of Mathematics, Faculty of Science and Arts-Khulais, King Abdulaziz University, Jeddah (Saudi Arabia); Department of mathematics, Faculty of Science, Sohag University, Sohag (Egypt)

    2015-03-01

    In the present work, we consider the problem of fractional order thermoelastic interaction in a material placed in a magnetic field and subjected to a moving plane of heat source. The basic equations have been written in the form of a vector–matrix differential equation in the Laplace transform domain, which is then solved by an eigenvalue approach. The inverse Laplace transforms are computed numerically and some comparisons have been shown in figures to estimate the effect of each of the fractional order, heat source velocity, time and the magnetic field and parameters. - Highlights: • The problem of fractional order thermoelastic interaction in a material placed in a magnetic field and subjected to a moving plane of heat source. • The eigenvalue approach gives exact solution in the Laplace domain without any assumed restrictions on the actual physical quantities. • Numerical results for the temperature, displacement and the stress distributions are represented graphically.

  13. Optimal Homotopy Asymptotic Solution for Exothermic Reactions Model with Constant Heat Source in a Porous Medium

    Directory of Open Access Journals (Sweden)

    Fazle Mabood

    2015-01-01

    Full Text Available The heat flow patterns profiles are required for heat transfer simulation in each type of the thermal insulation. The exothermic reaction models in porous medium can prescribe the problems in the form of nonlinear ordinary differential equations. In this research, the driving force model due to the temperature gradients is considered. A governing equation of the model is restricted into an energy balance equation that provides the temperature profile in conduction state with constant heat source on the steady state. The proposed optimal homotopy asymptotic method (OHAM is used to compute the solutions of the exothermic reactions equation.

  14. Demonstration of a non-contact x-ray source using an inductively heated pyroelectric accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Klopfer, Michael; Satchouk, Vladimir; Cao, Anh; Wolowiec, Thomas; Alivov, Yahya; Molloi, Sabee, E-mail: symolloi@uci.edu

    2015-04-11

    X-ray emission from pyroelectric sources can be produced through non-contact thermal cycling using induction heating. In this study, we demonstrated a proof of concept non-contact x-ray source powered via induction heating. An induction heater operating at 62.5 kHz provided a total of 6.5 W of delivered peak thermal power with 140 V DC of driving voltage. The heat was applied to a ferrous substrate mechanically coupled to a cubic 1 cm{sup 3} Lithium Niobate (LiNbO{sub 3}) pyroelectric crystal maintained in a 3–12 mTorr vacuum. The maximum temperature reached was 175 °C in 86 s of heating. The cooling cycle began immediately after heating and was provided by passive radiative cooling. The total combined cycle time was 250 s. x-ray photons were produced and analyzed in both heating and cooling phases. Maximum photon energies of 59 keV and 55 keV were observed during heating and cooling, respectively. Non-contact devices such as this, may find applications in cancer therapy (brachytherapy), non-destructive testing, medical imaging, and physics education fields.

  15. Energy from Waste: Reuse of Compost Heat as a Source of Renewable Energy

    Directory of Open Access Journals (Sweden)

    G. Irvine

    2010-01-01

    Full Text Available An in-vessel tunnel composting facility in Scotland was used to investigate the potential for collection and reuse of compost heat as a source of renewable energy. The amount of energy offered by the compost was calculated and seasonal variations analysed. A heat exchanger was designed in order to collect and transfer the heat. This allowed heated water of 47.3oC to be obtained. The temperature could be further increased to above 60oC by passing it through multiple tunnels in series. Estimated costs for installing and running the system were calculated. In order to analyse these costs alternative solar thermal and ground source heat pump systems were also designed. The levels of supply and economic performance were then compared. A capital cost of £11,662 and operating cost of £1,039 per year were estimated, resulting in a cost of £0.50 per kWh for domestic water and £0.10 per kWh for spatial heat. Using the heat of the compost was found to provide the most reliable level of supply at a similar price to its rivals.

  16. Numerical simulation of precessing vortex core dumping by localized nonstationary heat source

    Science.gov (United States)

    Porfiriev, Denis; Gorbunova, Anastasiya; Zavershinsky, Igor; Sugak, Semen; Molevich, Nonna

    2016-10-01

    The precessing vortex core (PVC) is a crucial structure for many technical devices with the heat release. For this purpose, we performed the 3D numerical simulations of PVC in the swirling flow created in the open tube with the paraxial nonstationary heat source. Power of the source was modulated by sinusoidal law. We showed that three turbulence models give the qualitatively similar dependences of PVC frequency and amplitude on the heat-source power. The numerical simulation demonstrated that the obtained PVC is a left-handed co-rotated bending single-vortex structure. For considered values of the swirl and mass flow rate, we obtained that, for wide range of modulation frequencies, the growth of the heat-source power leads to gradual increase in the PVC frequency and slow change in the amplitude of vortex core oscillations. However, for specific modulation frequency, which depends on the tube geometry, dependencies of the PVC frequency and the amplitudes of oscillations have distinct maximum and minimum. Which means that, under specific conditions, flow pattern changes dramatically and precession is almost dumped at the relatively low values of heat power.

  17. Thermal modeling of multi-shape heating sources on n-layer electronic board

    Directory of Open Access Journals (Sweden)

    Monier-Vinard Eric

    2017-01-01

    Full Text Available The present work completes the toolbox of analytical solutions that deal with resolving steady-state temperatures of a multi-layered structure heated by one or many heat sources. The problematic of heating sources having non-rectangular shapes is addressed to enlarge the capability of analytical approaches. Moreover, various heating sources could be located on the external surfaces of the sandwiched layers as well as embedded at interface of its constitutive layers. To demonstrate its relevance, the updated analytical solution has been compared with numerical simulations on the case of a multi-layered electronic board submitted to a set of heating source configurations. The comparison shows a high agreement between analytical and numerical calculations to predict the centroid and average temperatures. The promoted analytical approach establishes a kit of practical expressions, easy to implement, which would be cumulated, using superposition principle, to help electronic designers to early detect component or board temperatures beyond manufacturer limit. The ability to eliminate bad concept candidates with a minimum of set-up, relevant assumptions and low computation time can be easily achieved.

  18. Suppression of cyclotron instability in Electron Cyclotron Resonance ion sources by two-frequency heating

    Energy Technology Data Exchange (ETDEWEB)

    Skalyga, V. [Institute of Applied Physics of Russian Academy of Sciences, 46 Ulyanova st., Nizhny Novgorod (Russian Federation); Lobachevsky State University of Nizhny Novgorod (UNN), 23 Gagarina st., Nizhny Novgorod (Russian Federation); Izotov, I.; Mansfeld, D. [Institute of Applied Physics of Russian Academy of Sciences, 46 Ulyanova st., Nizhny Novgorod (Russian Federation); Kalvas, T.; Koivisto, H.; Komppula, J.; Kronholm, R.; Laulainen, J.; Tarvainen, O. [Department of Physics, University of Jyväskylä, Jyväskylä (Finland)

    2015-08-15

    Multiple frequency heating is one of the most effective techniques to improve the performance of Electron Cyclotron Resonance (ECR) ion sources. The method increases the beam current and average charge state of the extracted ions and enhances the temporal stability of the ion beams. It is demonstrated in this paper that the stabilizing effect of two-frequency heating is connected with the suppression of electron cyclotron instability. Experimental data show that the interaction between the secondary microwave radiation and the hot electron component of ECR ion source plasmas plays a crucial role in mitigation of the instabilities.

  19. Induction heating pure vapor source of high temperature melting point materials on electron cyclotron resonance ion source.

    Science.gov (United States)

    Kutsumi, Osamu; Kato, Yushi; Matsui, Yuuki; Kitagawa, Atsushi; Muramatsu, Masayuki; Uchida, Takashi; Yoshida, Yoshikazu; Sato, Fuminobu; Iida, Toshiyuki

    2010-02-01

    Multicharged ions that are needed are produced from solid pure material with high melting point in an electron cyclotron resonance ion source. We develop an evaporator by using induction heating (IH) with multilayer induction coil, which is made from bare molybdenum or tungsten wire without water cooling and surrounding the pure vaporized material. We optimize the shapes of induction coil and vaporized materials and operation of rf power supply. We conduct experiment to investigate the reproducibility and stability in the operation and heating efficiency. IH evaporator produces pure material vapor because materials directly heated by eddy currents have no contact with insulated materials, which are usually impurity gas sources. The power and the frequency of the induction currents range from 100 to 900 W and from 48 to 23 kHz, respectively. The working pressure is about 10(-4)-10(-3) Pa. We measure the temperature of the vaporized materials with different shapes, and compare them with the result of modeling. We estimate the efficiency of the IH vapor source. We are aiming at the evaporator's higher melting point material than that of iron.

  20. Heat transfer in inclined air rectangular cavities with two localized heat sources

    Directory of Open Access Journals (Sweden)

    Samy M. Elsherbiny

    2015-12-01

    The investigation used rectangular enclosures with position ratios of the heaters, B1 = 0.25, B2 = 0.75, size ratio, ɛ = 0.25, and covered Rayleigh numbers based on scale length, s/A ranging from 103 to 106. The tilt angle from the horizontal was changed from Φ = 0° to 180°, and the aspect ratio was taken as A = 1, 5, and 10. The results are presented graphically in the form of streamlines and isotherm contour plots. The heat transfer characteristics, and average Nusselt numbers were also presented. A correlation for Nu is also given.

  1. THE NATURAL CONVECTION OF AQUIFERS WITH CONSTANT HEAT SOURCES AND ITS INFLUENCE ON TEMPERATURE FIELDS

    Institute of Scientific and Technical Information of China (English)

    LIU Guo-qing; ZHOU Zhi-fang

    2012-01-01

    By combining sand tank tests with numerical simulations,this paper studies the temperature fields around constant heat sources to reveal the mechanism of the natural convection and its influence on the temperature fields in the process of energy storage.Using the “24-channel temperature auto acquisition system” developed by our research group in the tests,the temperatures are recorded at measuring points within the research area in the tests,the revised Brinkman equation and a transfer-convection balance model are used for solving the aquifer water-thermal coupling problems,and through comparison of the test results with the calculation results,it is discovered that the influence ranges and the variations of the two temperature fields are consistent,which validates the mathematical model.On the basis of this,we also study the influences of the heat source positions and the boundary conditions on the temperature fields,and the results show that,under the natural convection,the heat source positions may influence the distribution of the temperature fields,thus affect the energy storage.For the same energy storage layer,the temperature field for the top energy storage is characterized by a smaller heat influence range and a relatively concentrated temperature distribution.However,when the heat source is at the bottom,the range of a temperature field,and the temperature is relatively dispersed,which is not favorable to heat recycle,with the same heat sourcc position,the boundary conditions determine the size of the critical Rayleigh number,and thus have an influence on the occurrence and the strength of the natural convection,and accordingly,on the temperature fields.

  2. Sustainable renewable energy seawater desalination using combined-cycle solar and geothermal heat sources

    KAUST Repository

    Missimer, Thomas M.

    2013-01-01

    Key goals in the improvement of desalination technology are to reduce overall energy consumption, make the process "greener," and reduce the cost of the delivered water. Adsorption desalination (AD) is a promising new technology that has great potential to reduce the need for conventional power, to use solely renewable energy sources, and to reduce the overall cost of water treatment. This technology can desalt seawater or water of even higher salinity using waste heat, solar heat, or geothermal heat. An AD system can operate effectively at temperatures ranging from 55 to 80 °C with perhaps an optimal temperature of 80 °C. The generally low temperature requirement for the feedwater allows the system to operate quite efficiently using an alternative energy source, such as solar power. Solar power, particularly in warm dry regions, can generate a consistent water temperature of about 90 °C. Although this temperature is more than adequate to run the system, solar energy collection only can occur during daylight hours, thereby necessitating the use of heat storage during nighttime or very cloudy days. With increasing capacity, the need for extensive thermal storage may be problematic and could add substantial cost to the development of an AD system. However, in many parts of the world, there are subsurface geothermal energy sources that have not been extensively used. Combining a low to moderate geothermal energy recovery system to an AD system would provide a solution to the thermal storage issue. However, geothermal energy development from particularly Hot Dry Rock is limited by the magnitude of the heat flow required for the process and the thermal conductivity of the rock material forming the heat reservoir. Combining solar and geothermal energy using an alternating 12-h cycle would reduce the probability of depleting the heat source within the geothermal reservoir and provide the most effective use of renewable energy. © 2013 Desalination Publications.

  3. Mixed Convection Flow of Casson Nanofluid over a Stretching Sheet with Convectively Heated Chemical Reaction and Heat Source/Sink

    Directory of Open Access Journals (Sweden)

    T. Hayat

    2015-01-01

    Full Text Available The present study addresses the mixed convection flow of non-Newtonian nanofluid over a stretching surface in presence of thermal radiation, heat source/sink and first order chemical reaction. Casson fluid model is adopted in the present study. Magnetic field contribution is incorporated in the momentum equation whereas the aspects of nanoparticles are considered in the energy and concentration equations. Convective boundary conditions for both heat and mass transfer are utilized. Similarity transformations are employed to reduce the partial differential equations into ordinary differential equations. Series solutions of the resulting problem are obtained. Impacts of all the physical parameters on the velocity, temperature and concentration fields are analyzed graphically. Numerical values of different involved parameters for local skin friction coefficient, local Nusselt and Sherwood numbers are obtained and discussed.

  4. Field experiment on coalmine heat disaster governance using cold source from surface water

    Institute of Scientific and Technical Information of China (English)

    Guo Pingye; Zhu Guolong; Liu Yuqing; Duan Mengmeng; Wu Junyin

    2014-01-01

    Regarding the lack of cold source for underground cooling systems from either mine inflow or return air, field experiments were taken in a high temperature deep coal mine with abundant cold source from surface water. Taking Sanhejian coal mine as an example, this paper introduced the technology scheme of heat disaster governance using surface water cold source. The paper presents the basics of this field experiment at the beginning, following by the design and site layout of the cooling system including the analysis and calculation of cold source. Numerical calculation method is also applied based on the operation parameters to simulate the influence to the surface river ecosystem. The results suggest that the temperature of surface water shall be lower than 34 ?C after heat exchange, and when more cooling capacities are needed in the future, increasing the water flow is more favorable than increasing the cooling range of water, which is better for the ecological environment protection.

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

    Energy Technology Data Exchange (ETDEWEB)

    Fullam, H.T.

    1981-12-01

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

  6. Sources and potential application of waste heat utilization at a gas processing facility

    Science.gov (United States)

    Alshehhi, Alyas Ali

    Waste heat recovery (WHR) has the potential to significantly improve the efficiency of oil and gas plants, chemical and other processing facilities, and reduce their environmental impact. In this Thesis a comprehensive energy audit at Abu Dhabi Gas Industries Ltd. (GASCO) ASAB gas processing facilities is undertaken to identify sources of waste heat and evaluate their potential for on-site recovery. Two plants are considered, namely ASAB0 and ASAB1. Waste heat evaluation criteria include waste heat grade (i.e., temperature), rate, accessibility (i.e., proximity) to potential on-site waste heat recovery applications, and potential impact of recovery on installation performance and safety. The operating parameters of key waste heat source producing equipment are compiled, as well as characteristics of the waste heat streams. In addition, potential waste heat recovery applications and strategies are proposed, focusing on utilities, i.e., enhancement of process cooling/heating, electrical/mechanical power generation, and steam production. The sources of waste heat identified at ASAB facilities consist of gas turbine and gas generator exhaust gases, flared gases, excess propane cooling capacity, excess process steam, process gas air-cooler heat dissipation, furnace exhaust gases and steam turbine outlet steam. Of the above waste heat sources, exhaust gases from five gas turbines and one gas generator at ASAB0 plant, as well as from four gas turbines at ASAB1 plant, were found to meet the rate (i.e., > 1 MW), grade (i.e., > 180°C), accessibility (i.e., absorption refrigeration unit for gas turbine inlet air cooling, which would result in additional electric or mechanical power generation, and pre-cooling of process gas, which could reduce the need for or eliminate air coolers, as well as reduce propane chiller load, and ii) serve for heating of lean gas, which would reduce furnace load. At ASAB1, it is proposed that exhaust gases from all four gas turbines be used to

  7. Chemical characteristics and source apportionment of atmospheric particles during heating period in Harbin, China

    Institute of Scientific and Technical Information of China (English)

    Likun Huang; Guangzhi Wang

    2014-01-01

    Atmospheric particles (total suspended particles (TSPs); particulate matter (PM) with particle size below 10 μm,PM10; particulate matter with particle size below 2.5 μm,PM2.5)were collected and analyzed during heating and non-heating periods in Harbin.The sources of PM10 and PM2.5 were identified by the chemical mass balance (CMB) receptor model.Results indicated that PM2.5/TSP was the most prevalent and PM2.5 was the main component of PM10,while the presence of PM10-100 was relatively weak.SC42-and NO3-concentrations were more significant than other ions during the heating period.As compared with the non-heating period,Mn,Ni,Pb,S,Si,Ti,Zn,As,Ba,Cd,Cr,Fe and K were relatively higher during the heating period.In particular,Mn,Ni,S,Si,Ti,Zn and As in PM2.5 were obviously higher during the heating period.Organic carbon (OC) in the heating period was 2-5 times higher than in the non-heating period.Elemental carbon (EC) did not change much.OC/EC ratios were 8-11 during the heating period,which was much higher than in other Chinese cities (OC/EC:4-6).Results from the CMB indicated that 11 pollution sources were identified,of which traffic,coal combustion,secondary sulfate,secondary nitrate,and secondary organic carbon made the greatest contnbution.Before the heating period,dust and petrochemical industry made a larger contribution.In the heating period,coal combustion and secondary sulfate were higher.After the heating period,dust and petrochemical industry were highen Some hazardous components in PM2.5 were higher than in PM10,because PM2.5 has a higher ability to absorb toxic substances.Thus PM2.5 pollution is more significant regarding human health effects in the heating period.

  8. A small-plane heat source method for measuring the thermal conductivities of anisotropic materials

    Science.gov (United States)

    Cheng, Liang; Yue, Kai; Wang, Jun; Zhang, Xinxin

    2017-07-01

    A new small-plane heat source method was proposed in this study to simultaneously measure the in-plane and cross-plane thermal conductivities of anisotropic insulating materials. In this method the size of the heat source element is smaller than the sample size and the boundary condition is thermal insulation due to no heat flux at the edge of the sample during the experiment. A three-dimensional model in a rectangular coordinate system was established to exactly describe the heat transfer process of the measurement system. Using the Laplace transform, variable separation, and Laplace inverse transform methods, the analytical solution of the temperature rise of the sample was derived. The temperature rises calculated by the analytical solution agree well with the results of numerical calculation. The result of the sensitivity analysis shows that the sensitivity coefficients of the estimated thermal conductivities are high and uncorrelated to each other. At room temperature and in a high-temperature environment, experimental measurements of anisotropic silica aerogel were carried out using the traditional one-dimensional plane heat source method and the proposed method, respectively. The results demonstrate that the measurement method developed in this study is effective and feasible for simultaneously obtaining the in-plane and cross-plane thermal conductivities of the anisotropic materials.

  9. Model of the heat source of the Cerro Prieto magma-hydrothermal system, Baja California, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Elders, W.A.; Bird, D.K.; Williams, A.E.; Schiffman, P.; Cox, B.

    1982-08-10

    Earlier studies at Cerro Prieto by UCR have led to the development of a qualitative model for field flow in the geothermal system before it was drilled and perturbed by production. Current efforts are directed towards numerical modelling of heat and mass transfer in the system in this undisturbed state. A two-dimensional model assumes that the heat sources were a single basalt/gabbro intrusion which provided heat to the system as it cooled. After compiling various information on the physical properties of the reservoir, the enthalpy contained in two 1cm thick section across the reservoir orthogonal to each other was calculated. Next various shapes, sizes and depths for the intrusion as initial conditions and boundary conditions for the calculation of heat transfer were considered. A family of numerical models which so far gives the best matches to the conditions observed in the field today have in common a funnel-shaped intrusion with a top 4km wide emplaced at a depth of 5km some 30,000 to 50,000 years ago, providing heat to the geothermal system. Numerical modelling is still in progress. Although none of the models so far computed may be a perfect match for the thermal history of the reservoir, they all indicate that the intrusive heat source is young, close and large.

  10. Study on a groundwater source heat pump cooling system in solar greenhouse

    Energy Technology Data Exchange (ETDEWEB)

    Chai, Lilong; Ma, Chengwei [China Agricultural Univ., Beijing (China). Coll. of Water Conservancy and Civil Engineering. Dept. of Agricultural Structure and Bio-environmental Engineering], E-mail: macwbs@cau.edu.cn

    2008-07-01

    This study aims at exploiting the potential of ground source heat pump (GSHP) technology in cooling agricultural greenhouse, and advocating the use of renewable and clean energy in agriculture. GSHP has the multi-function of heating, cooling and dehumidifying, which is one of the fastest growing technologies of renewable energy air conditioning in recent years. The authors carried out experiment on the ground source heat pump system in cooling greenhouse in Beijing region during the summertime of 2007, and conducted analysis on the energy efficiency of the system by using coefficient of performance (COP). According to the data collected during Aug.13-18th, 2007, the coefficient of performance of GSHP system (COP{sub sys}) has reached 3.15 on average during the test. (author)

  11. Mathematical Modeling of Magneto Pulsatile Blood Flow Through a Porous Medium with a Heat Source

    Directory of Open Access Journals (Sweden)

    Sharma B.K

    2015-05-01

    Full Text Available In the present study a mathematical model for the hydro-magnetic non-Newtonian blood flow in the non-Darcy porous medium with a heat source and Joule effect is proposed. A uniform magnetic field acts perpendicular to the porous surface. The governing non-linear partial differential equations have been solved numerically by applying the explicit finite difference Method (FDM. The effects of various parameters such as the Reynolds number, hydro-magnetic parameter, Forchheimer parameter, Darcian parameter, Prandtl number, Eckert number, heat source parameter, Schmidt number on the velocity, temperature and concentration have been examined with the help of graphs. The present study finds its applications in surgical operations, industrial material processing and various heat transfer operations.

  12. Study on a groundwater source heat pump cooling system in solar greenhouse

    Energy Technology Data Exchange (ETDEWEB)

    Chai, Lilong; Ma, Chengwei [China Agricultural Univ., Beijing (China). Coll. of Water Conservancy and Civil Engineering. Dept. of Agricultural Structure and Bio-environmental Engineering], E-mail: macwbs@cau.edu.cn

    2008-07-01

    This study aims at exploiting the potential of ground source heat pump (GSHP) technology in cooling agricultural greenhouse, and advocating the use of renewable and clean energy in agriculture. GSHP has the multi-function of heating, cooling and dehumidifying, which is one of the fastest growing technologies of renewable energy air conditioning in recent years. The authors carried out experiment on the ground source heat pump system in cooling greenhouse in Beijing region during the summertime of 2007, and conducted analysis on the energy efficiency of the system by using coefficient of performance (COP). According to the data collected during Aug.13-18th, 2007, the coefficient of performance of GSHP system (COP{sub sys}) has reached 3.15 on average during the test. (author)

  13. General-purpose heat source safety verification test series: SVT-7 through SVT-10

    Science.gov (United States)

    George, T. G.; Pavone, D.

    1985-09-01

    The General-Purpose Heat Source (GPHS) is a modular component of the radioisotope thermoelectric generator that will supply power for the Galileo and Ulysses (formerly ISPM) space missions. The GPHS provides power by transmitting the heat of (238)PuO2 (ALPHA)-decay to an array of thermoelectric elements. Because the possibility of an orbital abort always exists, the heat source was designed and constructed to minimize plutonia release in any accident environment. The Safety Verification Test (SVT) series was formulated to evaluate the effectiveness of GPHS plutonia containment after atmospheric reentry and Earth impact. The first report (covering SVT-1 through SVT-6) described the results of flat and side-on module impacts. This report describes module impacts at angles of 15(0) and 30(0).

  14. General-purpose heat source safety verification test series: SVT-11 through SVT-13

    Science.gov (United States)

    George, T. G.; Pavone, D.

    1986-05-01

    The General-Purpose Heat Source (GPHS) is a modular component of the radioisotope thermoelectric generator that will provide power for the Galileo and Ulysses (formerly ISPM) space missions. The GPHS provides power by transmitting the heat of Pu -decay to an array of thermoelectric elements. Because the possibility of an orbital abort always exists, the heat source was designed and constructed to minimize plutonia release in any accident environment. The Safety Verification Test (SVT) series was formulated to evaluate the effectiveness of GPHS plutonia containment after atmospheric reentry and Earth impact. The first two reports (covering SVT-1 through SVT-10) described the results of flat, side-on, and angular module impacts against steel targets at 54 m/s. This report describes flat-on module impacts against concrete and granite targets, at velocities equivalent to or higher than previous SVTs.

  15. Calculation of temperature field in gas flow with internal heat source

    Directory of Open Access Journals (Sweden)

    Gerasimov Alexander V.

    2015-01-01

    Full Text Available Gas flow sequentially moving through three zones (input z1 of a cylindrical channel was considered. Analytical solutions taking into account the influence of heat source limitation in the axial direction and intensity of air flow in this direction on thermal balance were obtained.

  16. Finite element analysis of keyhole plasma arc welding based on an adaptive heat source mode

    Institute of Scientific and Technical Information of China (English)

    Hu Qingxian; Wu Chuansong; Zhang Yuming

    2007-01-01

    An adaptive heat source mode is proposed to account for the keyhole effect and the characteristics of volumetric distribution along the direction of the workpiece thickness. Finite element analysis of the temperature field in keyhole plasma arc welding is conducted and the weld geometry is obtained. The predicted results are in agreement with the measured ones.

  17. Alternative energy sources for the heating and cooling of a building

    CSIR Research Space (South Africa)

    Strydom, JFS

    1979-11-27

    Full Text Available The objective of two of the studies was to choose the most economical source of heating energy, taking cognizance of the building owner’s particular circumstances; in both cases a suitable alternative to light petroleum oil, which had been used...

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

    DEFF Research Database (Denmark)

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

    2017-01-01

    The Scandinavian countries Denmark, Norway and Sweden currently deploy large amounts of variable renewable energy (VRE) sources, especially wind power. This calls for additional flexibility in the power market. The right coupling to the underlying national and local district heating (DH) markets...

  19. Plasma diagnostics approach to welding heat source/molten pool interaction

    Energy Technology Data Exchange (ETDEWEB)

    Key, J.F.; McIlwain, M.E.; Isaacson, L.

    1980-01-01

    Plasma diagnostic techniques show that weld fusion zone profile and loss of metal vapors from the molten pool are strongly dependent on both the intensity and distribution of the heat source. These plasma properties, are functions of cathode vertex angle and thermal conductivity of the shielding gas, especially near the anode.

  20. Impacts of New EU and Czech Environmental Legislation on Heat and Electricity Prices of Combined Heat and Power Sources in the Czech Republic

    Directory of Open Access Journals (Sweden)

    J. Vecka

    2011-01-01

    Full Text Available In my economic model I calculate the impact of the new EU ETS Directive, the Industrial Emissions Directive and the new air protection law on future heat and electricity prices for combined heat and power sources. I discover that there will be a significant increase in heat and electricity prices, especially because of the implementation of new so-called benchmark tools for allocating allowances. The main problem of large heat producers in this respect is loss of competitiveness on the heat market due to emerging stricter environmental legislation, which is not applied to competitors on the heat market (smaller heat sources. There is also lack of clarity about the modalities for allocating free allowances, and about the future development of the whole carbon market (the future European allowance price.

  1. Chemical reaction and heat source effects on MHD oscillatory flow in an irregular channel

    Directory of Open Access Journals (Sweden)

    P.V. Satya Narayana

    2016-12-01

    Full Text Available This paper investigates the effect of heat and mass transfer on MHD oscillatory flow in an asymmetric wavy channel with chemical reaction and heat source. The unsteadiness in the flow is due to an oscillatory pressure gradient across the ends of the channel. A magnetic field of uniform strength is applied in the direction perpendicular to the channel. However, the induced magnetic field is neglected due to the assumption of small magnetic Reynolds number. The temperature difference of the channel is also assumed high enough to induce heat transfer due to radiation. The governing equations are solved analytically by regular perturbation method. The analytical results are evaluated numerically and then are presented graphically to discuss the effects of different parameters entering into the problem. It is observed that the heat transport of a system is more increased in oscillatory flow than in ordinary conduction.

  2. Optimization and thermoeconomics research of a large reclaimed water source heat pump system.

    Science.gov (United States)

    Zhang, Zi-ping; Du, Fang-hui

    2013-01-01

    This work describes a large reclaimed water source heat pump system (RWSHPS) and elaborates on the composition of the system and its design principles. According to the characteristics of the reclaimed water and taking into account the initial investment, the project is divided into two stages: the first stage adopts distributed heat pump heating system and the second adopts the combination of centralized and decentralized systems. We analyze the heating capacity of the RWSHPS, when the phase II project is completed, the system can provide hydronic heating water with the supply and return water temperature of 55°C/15°C and meet the hydronic heating demand of 8 million square meters of residential buildings. We make a thermal economics analysis by using Thermal Economics theory on RWSHPS and gas boiler system, it is known that the RWSHPS has more advantages, compared with the gas boiler heating system; both its thermal efficiency and economic efficiency are relatively high. It provides a reference for future applications of the RWSHPS.

  3. Sensitivity analysis on the performances of a closed-loop Ground Source Heat Pump

    Science.gov (United States)

    Casasso, Alessandro; Sethi, Rajandrea

    2014-05-01

    Ground Source Heat Pumps (GSHP) permit to achieve a significant reduction of greenhouse gas emissions, and the margins for economic saving of this technology are strongly correlated to the long-term sustainability of the exploitation of the heat stored in the soil. The operation of a GSHP over its lifetime should be therefore modelled considering realistic conditions, and a thorough characterization of the physical properties of the soil is essential to avoid large errors of prediction. In this work, a BHE modelling procedure with the finite-element code FEFLOW is presented. Starting from the governing equations of the heat transport in the soil around a GSHP and inside the BHE, the most important parameters are individuated and the adopted program settings are explained. A sensitivity analysis is then carried on both the design parameters of the heat exchanger, in order to understand the margins of improvement of a careful design and installation, and the physical properties of the soil, with the aim of quantifying the uncertainty induced by their variability. The relative importance of each parameter is therefore assessed by comparing the statistical distributions of the fluid temperatures and estimating the energy consumption of the heat pump, and practical conclusions are from these results about the site characterization, the design and the installation of a BHE. References Casasso A., Sethi R., 2014 Efficiency of closed loop geothermal heat pumps: A sensitivity analysis, Renewable Energy 62 (2014), pp. 737-746 Chiasson A.C., Rees S.J., Spitler J.D., 2000, A preliminary assessment of the effects of groundwater flow on closed-loop ground-source heat pump systems, ASHRAE Transactions 106 (2000), pp. 380-393 Delaleux F., Py X., Olives R., Dominguez A., 2012, Enhancement of geothermal borehole heat exchangers performances by improvement of bentonite grouts conductivity, Applied Thermal Engineering 33-34, pp. 92-99 Diao N., Li Q., Fang Z., 2004, Heat transfer in

  4. Ground heat flux and power sources of low-enthalpy geothermal systems

    Science.gov (United States)

    Bayer, Peter; Blum, Philipp; Rivera, Jaime A.

    2015-04-01

    Geothermal heat pumps commonly extract energy from the shallow ground at depths as low as approximately 400 m. Vertical borehole heat exchangers are often applied, which are seasonally operated for decades. During this lifetime, thermal anomalies are induced in the ground and surface-near aquifers, which often grow over the years and which alleviate the overall performance of the geothermal system. As basis for prediction and control of the evolving energy imbalance in the ground, focus is typically set on the ground temperatures. This is reflected in regulative temperature thresholds, and in temperature trends, which serve as indicators for renewability and sustainability. In our work, we examine the fundamental heat flux and power sources, as well as their temporal and spatial variability during geothermal heat pump operation. The underlying rationale is that for control of ground temperature evolution, knowledge of the primary heat sources is fundamental. This insight is also important to judge the validity of simplified modelling frameworks. For instance, we reveal that vertical heat flux from the surface dominates the basal heat flux towards a borehole. Both fluxes need to be accounted for as proper vertical boundary conditions in the model. Additionally, the role of horizontal groundwater advection is inspected. Moreover, by adopting the ground energy deficit and long-term replenishment as criteria for system sustainability, an uncommon perspective is adopted that is based on the primary parameter rather than induced local temperatures. In our synthetic study and dimensionless analysis, we demonstrate that time of ground energy recovery after system shutdown may be longer than what is expected from local temperature trends. In contrast, unrealistically long recovery periods and extreme thermal anomalies are predicted without account for vertical ground heat fluxes and only when the energy content of the geothermal reservoir is considered.

  5. Dynamic effects on containment of air-curtain fume hood operated with heat source.

    Science.gov (United States)

    Chen, Jia-Kun; Huang, Rong Fung; Hsin, Pei-Yi

    2012-01-01

    This study focused on the leakage characteristics of the air-curtain fume hood that are subject to the influences of sash movement and walk-by motion while a high temperature heat source was operated in the hood. The flow visualization and trace gas test method were used to investigate the performance of the air-curtain fume hood. An electric heater was placed in the hood to simulate the heat source. The temperature of the heat source installed inside the air-curtain fume hood varied between 180°C and 300°C. Trace gas tests following the dynamic test methods of EN-14175 protocol were employed to measure the spillages of sulfur hexafluoride gas that were released in the hood. When subject to the influence of sash movement at a heat source temperature lower than 260°C, the leakage level was high at the suction velocity V(s) 10 m/sec. When subject to the influence of people walk-by, the leakage level was relatively low at the suction velocity larger than 8 m/sec at sash height H = 50 cm. The height of the sash opening was a crucial parameter for the containment of the air-curtain fume hood. At the sash opening lower than about 25 cm, suction velocity less than or equal to 6 m/sec was enough to make the sulfur hexafluoride leakage less than the threshold value, 0.65 ppm, suggested by the BG Chemie. The air-curtain fume hood presented a great performance to resist the effect of drafts even though there was a high temperature heat source working in the hood.

  6. Identifying (subsurface) anthropogenic heat sources that influence temperature in the drinking water distribution system

    Science.gov (United States)

    Agudelo-Vera, Claudia M.; Blokker, Mirjam; de Kater, Henk; Lafort, Rob

    2017-09-01

    The water temperature in the drinking water distribution system and at customers' taps approaches the surrounding soil temperature at a depth of 1 m. Water temperature is an important determinant of water quality. In the Netherlands drinking water is distributed without additional residual disinfectant and the temperature of drinking water at customers' taps is not allowed to exceed 25 °C. In recent decades, the urban (sub)surface has been getting more occupied by various types of infrastructures, and some of these can be heat sources. Only recently have the anthropogenic sources and their influence on the underground been studied on coarse spatial scales. Little is known about the urban shallow underground heat profile on small spatial scales, of the order of 10 m × 10 m. Routine water quality samples at the tap in urban areas have shown up locations - so-called hotspots - in the city, with relatively high soil temperatures - up to 7 °C warmer - compared to the soil temperatures in the surrounding rural areas. Yet the sources and the locations of these hotspots have not been identified. It is expected that with climate change during a warm summer the soil temperature in the hotspots can be above 25 °C. The objective of this paper is to find a method to identify heat sources and urban characteristics that locally influence the soil temperature. The proposed method combines mapping of urban anthropogenic heat sources, retrospective modelling of the soil temperature, analysis of water temperature measurements at the tap, and extensive soil temperature measurements. This approach provided insight into the typical range of the variation of the urban soil temperature, and it is a first step to identifying areas with potential underground heat stress towards thermal underground management in cities.

  7. Assessment of heat sources on the control of fast flow of Vestfonna Ice Cap, Svalbard

    Directory of Open Access Journals (Sweden)

    M. Schäfer

    2013-10-01

    Full Text Available The dynamic regime of Svalbard's Nordaustlandet ice caps is dominated by fast flowing outlet glaciers, making assessment of their response to climate change challenging. A key element of the challenge lies in the fact that the motion of fast outlet glaciers occurs largely through basal sliding, and is governed by physical processes at the glacier bed, processes that are difficult both to observe and to simulate. Up to now, most of the sliding laws used in ice flow models were based on uniform parameters with a condition on temperature to identify regions of basal sliding. However these models are usually not able to reproduce observed velocities with sufficient accuracy. With the development of inverse methods, it is now common to infer a spatially varying field of sliding parameters from surface ice-velocity observations. These parameter distributions usually reflect a high spatial variability and represent valuable information to understand and test various hypotheses on physical processes involved in sliding. However, in these models, basal sliding is uncoupled from the thermal regime of basal ice and the evolution of the sliding parameters in prognostic simulations remains problematic. Here we explore the role of different heat sources (friction heating, strain heating and latent heat through percolation of melt water on the development of sliding and fast flow through thermomechanical coupling on Nordaustlandet outlet glaciers. We focus on Vestfonna with a special emphasis on Franklinbreen, a fast flowing outlet glacier which has been observed to accelerate between 1995 and 2008 and possibly already prior to 1995. We try to reconcile the impacts of temperature and heat sources on basal friction coefficients inferred from observed surface velocities during these two periods. Our simulations reproduce a temperature profile from borehole measurements, allowing an interpretation of the vertical temperature structure in terms of temporal

  8. Improvement of efficiency and temperature control of induction heating vapor source on electron cyclotron resonance ion source.

    Science.gov (United States)

    Takenaka, T; Kiriyama, R; Muramatsu, M; Kitagawa, A; Uchida, T; Kurisu, Y; Nozaki, D; Yano, K; Yoshida, Y; Sato, F; Kato, Y; Iida, T

    2012-02-01

    An electron cyclotron resonance ion source (ECRIS) is used to generate multicharged ions for many kinds of the fields. We have developed an evaporator by using induction heating method that can generate pure vapor from solid state materials in ECRIS. We develop the new matching and protecting circuit by which we can precisely control the temperature of the induction heating evaporator. We can control the temperature within ±15 °C around 1400 °C under the operation pressure about 10(-4) Pa. We are able to use this evaporator for experiment of synthesizing process to need pure vapor under enough low pressure, e.g., experiment of generation of endohedral Fe-fullerene at the ECRIS.

  9. An Experimental Study of Waveguide Coupled Microwave Heating with Conventional Multicusp Negative Ion Source

    CERN Document Server

    Komppula, J; Koivisto, H; Laulainen, J; Tarvainen, O

    2015-01-01

    Negative ion production with conventional multicusp plasma chambers utilizing 2.45 GHz microwave heating is demonstrated. The experimental results were obtained with the multicusp plasma chambers and extraction systems of the RFdriven RADIS ion source and the filament driven arc discharge ion source LIISA. A waveguide microwave coupling system, which is almost similar to the one used with the SILHI ion source, was used. The results demonstrate that at least one third of negative ion beam obtained with inductive RF-coupling (RADIS) or arc discharge (LIISA) can be achieved with 1 kW of 2.45 GHz microwave power in CW mode without any modification of the plasma chamber. The co-extracted electron to H^- ratio and the optimum pressure range were observed to be similar for both heating methods. The behaviour of the plasma implies that the energy transfer from the microwaves to the plasma electrons is mainly an off-resonance process.

  10. An experimental study of waveguide coupled microwave heating with conventional multicusp negative ion sources

    Science.gov (United States)

    Komppula, J.; Kalvas, T.; Koivisto, H.; Laulainen, J.; Tarvainen, O.

    2015-04-01

    Negative ion production with conventional multicusp plasma chambers utilizing 2.45 GHz microwave heating is demonstrated. The experimental results were obtained with the multicusp plasma chambers and extraction systems of the RF-driven RADIS ion source and the filament driven arc discharge ion source LIISA. A waveguide microwave coupling system, which is almost similar to the one used with the SILHI ion source, was used. The results demonstrate that at least one third of negative ion beam obtained with inductive RF-coupling (RADIS) or arc discharge (LIISA) can be achieved with 1 kW of 2.45 GHz microwave power in CW mode without any modification of the plasma chamber. The co-extracted electron to H- ratio and the optimum pressure range were observed to be similar for both heating methods. The behaviour of the plasma implies that the energy transfer from the microwaves to the plasma electrons is mainly an off-resonance process.

  11. 基于复合热源的热泵型空调器%Heat pump air conditioner based on multiple heat sources

    Institute of Scientific and Technical Information of China (English)

    吴国珊; 凌勋

    2012-01-01

    It is proposed that the air-water multiple heat sources could be the heat source of heat pump air conditioner. Based on the current study condition, the heat pump air conditioner which has a air/family waste water multiple heat source is preliminary designed. The working cycle and characteristics of the air conditioner are analyzed by using the thermodynamic principle. The results show that the refrigeration performance of the heat pump air conditioner is better than that of air source heat pump air conditioner, the heating performance and the situation which the outdoor heat exchanger frosts are improved.%提出将空气-水作为热泵型空调器的复合热源.根据当前的研究状况,初步设计空气-水复合热源热泵型空调器,利用热力学原理分析该空调器的工作循环和特点,结果表明该空调器的制冷性能高于空气源热泵空调器,制热和室外换热器结霜状况得到一定改善.

  12. Waste heat recovery from the European Spallation Source cryogenic helium plants - implications for system design

    Science.gov (United States)

    Jurns, John M.; Bäck, Harald; Gierow, Martin

    2014-01-01

    The European Spallation Source (ESS) neutron spallation project currently being designed will be built outside of Lund, Sweden. The ESS design includes three helium cryoplants, providing cryogenic cooling for the proton accelerator superconducting cavities, the target neutron source, and for the ESS instrument suite. In total, the cryoplants consume approximately 7 MW of electrical power, and will produce approximately 36 kW of refrigeration at temperatures ranging from 2-16 K. Most of the power consumed by the cryoplants ends up as waste heat, which must be rejected. One hallmark of the ESS design is the goal to recycle waste heat from ESS to the city of Lund district heating system. The design of the cooling system must optimize the delivery of waste heat from ESS to the district heating system and also assure the efficient operation of ESS systems. This report outlines the cooling scheme for the ESS cryoplants, and examines the effect of the cooling system design on cryoplant design, availability and operation.

  13. IMPACT OF GEOTHERMAL GRADIENT ON GROUND SOURCE HEAT PUMP SYSTEM MODELING

    Directory of Open Access Journals (Sweden)

    Tomislav Kurevija

    2014-07-01

    Full Text Available ndisturbed ground temperature is one of the most crucial thermogeological parameters needed for shallow geothermal resources assessment. Energy considered to be geothermal is energy stored in the ground at depths where solar radiation has no effect. At depth where undisturbed ground temperature occurs there is no influence of seasonal variations in air temperature from surface. Exact temperature value, and depth where it occurs, is functionally dependent on surface climate parameters and thermogeologic properties of ground. After abovementioned depth, increase of ground temperature is solely dependent on geothermal gradient. Accurately determined value of undisturbed ground temperature is beneficial for proper sizing of borehole heat exchangers. On practical example of building which is being heated and cooled with shallow geothermal resource, influences of undisturbed ground temperature and geothermal gradient, on size of borehole heat exchanger are going to be presented. Sizing of borehole heat exchanger was calculated with commercial software Ground Loop Designer (GLD, which uses modified line source and cylinder source solutions of heat conduction in solids.

  14. Performance and Economic Modeling of Horizontally Drilled Ground-Source Heat Pumps in Select California Climates

    Science.gov (United States)

    Wiryadinata, Steven

    Service life modeling was performed to gage the viability of unitary 3.5 kWt, ground-source terminal heat pumps (GTHP) employing horizontal directionally drilled geothermal heat exchangers (GHX) over air-source terminal heat pumps (PTHP) in hotels and motels and residential apartment building sectors in California's coastal and inland climates. Results suggest the GTHP can reduce hourly peak demand for the utility by 7%-25% compared to PTHP, depending on the climate and building type. The annual energy savings, which range from -1% to 5%, are highly dependent on the GTHP pump energy use relative to the energy savings attributed to the difference in ground and air temperatures (DeltaT). In mild climates with small ?T, the pump energy use may overcome any advantage to utilizing a GHX. The majority of total levelized cost savings - ranging from 0.18/ft2 to 0.3/ft 2 - are due to reduced maintenance and lifetime capital cost normally associated with geothermal heat pump systems. Without these reductions (not validated for the GTHP system studied), the GTHP technology does not appear to offer significant advantages over PTHP in the climate zones studied here. The GTHP levelized cost was most sensitive to variations in installed cost and in some cases, energy use (influenced by climate zone choice), which together highlights the importance of climate selection for installation, and the need for larger market penetration of ground-source systems in order to bring down installed costs as the technology matures.

  15. Air Source Heat Pump a Key Role in the Development of Smart Buildings in Future Energy Systems

    DEFF Research Database (Denmark)

    Craciun, Vasile S.; Trifa, Viorel; Bojesen, Carsten

    2012-01-01

    of energy is used for space heating, space cooling, and domestic hot water production which are provided to residential and commercial buildings. Air source heat pumps (ASHP) are widely used conversion technologies all over the world for providing building thermal energy services as: cooling, heating...

  16. 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.

  17. Assessment of heat sources on the control of fast flow of Vestfonna ice cap, Svalbard

    Science.gov (United States)

    Schäfer, M.; Gillet-Chaulet, F.; Gladstone, R.; Pettersson, R.; Pohjola, V. A.; Strozzi, T.; Zwinger, T.

    2014-10-01

    Understanding the response of fast flowing ice streams or outlet glaciers to changing climate is crucial in order to make reliable projections of sea level change over the coming decades. Motion of fast outlet glaciers occurs largely through basal motion governed by physical processes at the glacier bed, which are not yet fully understood. Various subglacial mechanisms have been suggested for fast flow but common to most of the suggested processes is the requirement of presence of liquid water, and thus temperate conditions. We use a combination of modelling, field, and remote observations in order to study links between different heat sources, the thermal regime and basal sliding in fast flowing areas on Vestfonna ice cap. A special emphasis lies on Franklinbreen, a fast flowing outlet glacier which has been observed to accelerate recently. We use the ice flow model Elmer/Ice including a Weertman type sliding law and a Robin inverse method to infer basal friction parameters from observed surface velocities. Firn heating, i.e. latent heat release through percolation of melt water, is included in our model; its parameterisation is calibrated with the temperature record of a deep borehole. We found that strain heating is negligible, whereas friction heating is identified as one possible trigger for the onset of fast flow. Firn heating is a significant heat source in the central thick and slow flowing area of the ice cap and the essential driver behind the ongoing fast flow in all outlets. Our findings suggest a possible scenario of the onset and maintenance of fast flow on the Vestfonna ice cap based on thermal processes and emphasise the role of latent heat released through refreezing of percolating melt water for fast flow. However, these processes cannot yet be captured in a temporally evolving sliding law. In order to simulate correctly fast flowing outlet glaciers, ice flow models not only need to account fully for all heat sources, but also need to incorporate

  18. Application analysis of ground source heat pumps in building space conditioning

    Energy Technology Data Exchange (ETDEWEB)

    Qian, Hua; Wang, Yungang

    2013-07-01

    The adoption of geothermal energy in space conditioning of buildings through utilizing ground source heat pump (GSHP, also known as geothermal heat pump) has increased rapidly during the past several decades. However, the impacts of the GSHP utilization on the efficiency of heat pumps and soil temperature distribution remained unclear and needs further investigation. This paper presents a novel model to calculate the soil temperature distribution and the coefficient of performance (COP) of GSHP. Different scenarios were simulated to quantify the impact of different factors on the GSHP performance, including heat balance, daily running mode, and spacing between boreholes. Our results show that GSHP is suitable for buildings with balanced cooling and heating loads. It can keep soil temperature at a relatively constant level for more than 10 years. Long boreholes, additional space between boreholes, intermittent running mode will improve the performance of GSHP, but large initial investment is required. The improper design will make the COP of GSHP even lower than traditional heat pumps. Professional design and maintenance technologies are greatly needed in order to promote this promising technology in the developing world.

  19. Regularities pertinent to heat transfer between torch gas layers and steam boiler firebox waterwalls. Part I. Geometrical and physical torch model as a source of heat radiation

    Science.gov (United States)

    Makarov, A. N.

    2014-09-01

    The progress seen in the 19th-21st centuries in the development of methods for calculating heat transfer in torch furnaces, fireboxes, and combustion chambers is analyzed. Throughout the 20th century, calculations of heat transfer were carried out based on the law for radiation from solid bodies deduced by Y. Stefan and L. Boltzmann. It is shown that the use of this law for calculating heat transfer of a torch (a gaseous source of radiation) in heating furnaces and power-generating installations leads to incorrect results. It is substantiated that there is crisis of methods for calculating heat transfer in torch furnaces and power-generating installations. Geometrical and physical torch models in the form of radiating cylindrical gas volumes as sources of heat radiation are proposed for overcoming this crisis.

  20. Effect of working fluids and internal diameters on thermal performance of vertical and horizontal closed-loop pulsating heat pipes with multiple heat sources

    Directory of Open Access Journals (Sweden)

    Kammuang-Lue Niti

    2016-01-01

    Full Text Available Some electrical applications have a number of heat sources. The closed-loop pulsating heat pipe (CLPHP is applied to transfer heat from these devices. Since the CLPHP primarily transfers heat by means of the working fluid’s phase change in a capillary tube, the thermal performance of the CLPHP significantly depends on the working fluid type and the tube’s internal diameter. In order to provide the fundamental information for manufacturers of heat exchangers, this study on the effect of working fluids and internal diameters has been conducted. Three electrical plate heaters were installed on the CLPHP as the heat sources. The experiments were conducted by varying the working fluid to be R123, ethanol, and water, and the internal diameter to be 1.0 mm, 1.5 mm, and 2.0 mm. For each set of the same working fluid and internal diameter, the input heat fluxes of the heat sources were also made to vary within six different patterns. It can be concluded that when the latent heat of evaporation increases - in the case of vertical CLPHP - and when the dynamic viscosity of the liquid increases - in the case of horizontal CLPHP - the thermal performance decreases. Moreover, when the internal diameter increases, the thermal performance increases for both of vertical and horizontal CLPHPs.

  1. Operation of the CAPRICE electron cyclotron resonance ion source applying frequency tuning and double frequency heating.

    Science.gov (United States)

    Maimone, F; Tinschert, K; Celona, L; Lang, R; Mäder, J; Rossbach, J; Spädtke, P

    2012-02-01

    The properties of the electromagnetic waves heating the electrons of the ECR ion sources (ECRIS) plasma affect the features of the extracted ion beams such as the emittance, the shape, and the current, in particular for higher charge states. The electron heating methods such as the frequency tuning effect and the double frequency heating are widely used for enhancing the performances of ECRIS or even for the routine operation during the beam production. In order to better investigate these effects the CAPRICE ECRIS has been operated using these techniques. The ion beam properties for highly charged ions have been measured with beam diagnostic tools. The reason of the observed variations of this performance can be related to the different electromagnetic field patterns, which are changing inside the plasma chamber when the frequency is varying.

  2. Environmental considerations for geothermal energy as a source for district heating

    Energy Technology Data Exchange (ETDEWEB)

    Rafferty, Kevin D.

    1996-01-01

    Geothermal energy currently provides a stable and environmentally attractive heat source for approximately 20 district heating (DH) systems in the United States. The use of this resource eliminates nearly 100% of the conventional fuel consumption (and, hence, the emissions) of the loads served by these systems. As a result, geothermal DH systems can rightfully claim the title of the most fuel-efficient CH systems in operations today. The cost of producing heat from a geothermal resource (including capitalization of the production facility and cost for pumping) amounts to an average of $1.00 per mission Btu (0.0034 $/kWh). The major environmental challenge for geothermal systems is proper management of the producing aquifer. Many systems are moving toward injection of the geothermal fluids to ensure long-term production.

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

    Science.gov (United States)

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

    2012-03-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Rogers, C.S.

    1993-07-01

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

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

    Science.gov (United States)

    Certified models meet all ENERGY STAR requirements as listed in the Version 5.0 ENERGY STAR Program Requirements for Air Source Heat Pump and Central Air Conditioner Equipment that are effective as of September 15, 2015. A detailed listing of key efficiency criteria are available at http://www.energystar.gov/index.cfm?c=airsrc_heat.pr_crit_as_heat_pumps Listed products have been submitted to EPA by ENERGY STAR partners that do not participate in the AHRI certification program. EPA will continue to update this list with products that are certified by EPA-recognized certification bodies other than AHRI. The majority of ENERGY STAR products, certified by AHRI, can be found on the CEE/AHRI Verified Directory at http://www.ceedirectory.org/

  6. System simulation for an untreated sewage source heat pump (USSHP) in winter

    Science.gov (United States)

    Qin, Na; Hao, Peng Z.

    2017-01-01

    The paper discusses the system characteristics of an untreated sewage source heat pump in winter. In this system, the sewage enters into the evaporator directly. The variable parameters to control the system contain the sewage temperature at evaporator inlet and the water temperature at condenser inlet. It is found that most parameters, except the condensation heat transfer coefficient, change in the form of sine wave the same as the sewage temperature at inlet. The heating load and consumed power are 12.9kW and 3.45kW when the sewage temperature at inlet is 13°C. COP is about 3.75 in the range of the sewage temperature at inlet of 12-13°C.

  7. Genotoxic effects of selected biocides on RTG-2 fish cells by means of a modified Fast Micromethod Assay.

    Science.gov (United States)

    Sánchez-Fortún, S; Llorente, M T; Castaño, A

    2005-06-01

    A sensitive in vitro assay for detecting DNA damage in RTG-2 cells culture is described. This assay employs a dye, PicoGreen double stranded DNA (dsDNA) quantitation reagent, which becomes intensely fluorescent upon binding nucleic acids. The assay includes a simple and rapid 50-min sample lysis in the presence of EDTA, SDS, and high urea concentration at pH 10, followed by time-dependent DNA denaturation at pH 11.6 after NaOH addition. The time course and the extent of DNA denaturation are followed in a microplate fluorescence reader at room temperature for less than 1h. Comparative studies between suspension and fixed RTG-2 cells indicated that it is possible to apply this methodology in both cases with good results. Neutral red assay was used for to determine the cellular viability when RTG-2 cultures were exposed to tetrakis(hydroxymethyl) phosphonium chloride (THPC) and benzalkonium chloride (BC), as biocides used in the disinfection of cooling towers. The results obtained by neutral red assay indicate IC(50(48)) values of 0.017 (0.011-0.028) and 2.71 (1.91-3.86) mg/L for tetrakis(hydroxymethyl) phosphonium chloride and benzalkonium chloride, respectively. DNA damage has been evaluated for both disinfectants in RTG-2 culture, by exposure to 1/10-, 1/25-, 1/50-, and 1/100-IC(50(48)) value, and the results obtained indicate a strain scission factor (SSF) of 0.126+/-0.014, 0.181+/-0.014, 0.217+/-0.013, and 0.245+/-0.013 in cell suspensions, and 0.077+/-0.019, 0.107+/-0.014, 0.151+/-0.014, and 0.202+/-0.015 in attached cells for tetrakis(hydroxymethyl) phosphonium chloride; while the SSF values for benzalkonium chloride are 0.023+/-0.009, 0.033+/-0.017, 0.068+/-0.012, and 0.088+/-0.015 in cell suspensions, and 0.033+/-0.010, 0.044+/-0.011, 0.080+/-0.009, and 0.093+/-0.010 in attached cells. Thus, the assay proposed in this study has made it possible to show DNA damage in RTG-2 cells when exposed to 0.2(1/100 IC(50(48))) and 300(1/10 IC(50(48))) Hg/L of tetrakis

  8. Investigation of acoustic gravity waves created by anomalous heat sources: experiments and theoretical analysis

    Science.gov (United States)

    Pradipta, R.; Lee, M. C.

    2013-07-01

    We have been investigating high-power radio wave-induced acoustic gravity waves (AGWs) at Gakona, Alaska, using the High-frequency Active Aurora Research Program (HAARP) heating facility (i.e. HF heater) and extensive diagnostic instruments. This work was aimed at performing a controlled study of the space plasma turbulence triggered by the AGWs originating from anomalous heat sources, as observed in our earlier experiments at Arecibo, Puerto Rico (Pradipta 2007 MS Thesis MIT Press, Cambridge, MA). The HF heater operated in continuous wave (CW) O-mode can heat ionospheric plasmas effectively to yield a depleted magnetic flux tube as rising plasma bubbles (Lee et al 1998 Geophys. Res. Lett. 25 579). Two processes are responsible for the depletion of the magnetic flux tube: (i) thermal expansion and (ii) chemical reactions caused by heated ions. The depleted plasmas create large density gradients that can augment spread F processes via generalized Rayleigh-Taylor instabilities (Lee et al 1999 Geophys. Res. Lett. 26 37). It is thus expected that the temperature of neutral particles in the heated ionospheric region can be increased. Such a heat source in the neutral atmosphere may potentially generate AGWs in the form of traveling ionospheric plasma disturbances (TIPDs). We should point out that these TIPDs have features distinctively different from electric and magnetic field (ExB) drifts of HF wave-induced large-scale non-propagating plasma structures. Moreover, it was noted in our recent study of naturally occurring AGW-induced TIDs that only large-scale AGWs can propagate upward to reach higher altitudes. Thus, in our Gakona experiments we select optimum heating schemes for HF wave-induced AGWs that can be distinguished from the naturally occurring ones. The generation and propagation of AGWs are monitored by MUIR (Modular Ultra high-frequency Ionospheric Radar), Digisonde and GPS/low-earth-orbit satellites. Our theoretical and experimental studies have shown that

  9. Heat Source Neutron Emission Rate Reduction Studies - Water Induced HF Liberation

    Science.gov (United States)

    Matonic, John; Brown, John; Foltyn, Liz; Garcia, Lawrence; Hart, Ron; Herman, David; Huling, Jeff; Pansoy-Hjelvik, M. E. Lisa; Sandoval, Fritz; Spengler, Diane

    2004-02-01

    Plutonium-238 oxide (238PuO2) is used in the fabrication of general purpose heat sources (GPHS) or light-weight radioisotope heater units (LWRHUs). The heat sources supply the thermal energy used in radioisotope thermoelectric generators to power spacecraft for deep space missions and to heat critical components in the cold environs of space. Los Alamos National Laboratory has manufactured heat sources for approximately two decades. The aqueous purification of 238PuO2 is required, due to rigorous total Pu-content, actinide and non-actinide metal impurity, and neutron emission rate specifications. The 238PuO2 aqueous purification process is a new capability at Los Alamos National Laboratory as previously, aqueous purified 238PuO2 occurred at other DOE complexes. The Pu-content and actinide and non-actinide metal impurity specifications are met well within specification in the Los Alamos process, though reduction in neutron emission rates have been challenging. High neutron emission rates are typically attributed to fluoride content in the oxide. The alpha decay from 238Pu results in α,n reactions with light elements such as 17O, 18O, and 19F resulting in high neutron emission rates in the purified 238PuO2. Simple 16O-exchange takes care of the high NER due to 17O, and 18O. A new method to reduce the NER due to 19F in the purified 238PuO2 is presented in this paper. The method involves addition of water to purified 238PuO2, followed by heating to remove the water and liberating fluoride as HF.

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

    Science.gov (United States)

    Jakkareddy, Pradeep S.; Balaji, C.

    2016-09-01

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

  11. A Strongly Heated Neutron Star in the Transient Z Source MAXI J0556-332

    Science.gov (United States)

    Homan, Jeroen; Fridriksson, Joel K.; Wijnands, Rudy; Cackett, Edward M.; Degenaar, Nathalie; Linares, Manuel; Lin, Dacheng; Remillard, Ronald A.

    2014-11-01

    We present Chandra, XMM-Newton, and Swift observations of the quiescent neutron star in the transient low-mass X-ray binary MAXI J0556-332. Observations of the source made during outburst (with the Rossi X-ray Timing Explorer) reveal tracks in its X-ray color-color and hardness-intensity diagrams that closely resemble those of the neutron-star Z sources, suggesting that MAXI J0556-332 had near- or super-Eddington luminosities for a large part of its ~16 month outburst. A comparison of these diagrams with those of other Z sources suggests a source distance of 46 ± 15 kpc. Fits to the quiescent spectra of MAXI J0556-332 with a neutron-star atmosphere model (with or without a power-law component) result in distance estimates of 45 ± 3 kpc, for a neutron-star radius of 10 km and a mass of 1.4 M ⊙. The spectra show the effective surface temperature of the neutron star decreasing monotonically over the first ~500 days of quiescence, except for two observations that were likely affected by enhanced low-level accretion. The temperatures we obtain for the fits that include a power law (kT_eff∞ = 184-308 eV) are much higher than those seen for any other neutron star heated by accretion, while the inferred cooling (e-folding) timescale (~200 days) is similar to other sources. Fits without a power law yield higher temperatures (kT_eff∞ = 190-336 eV) and a shorter e-folding time (~160 days). Our results suggest that the heating of the neutron-star crust in MAXI J0556-332 was considerably more efficient than for other systems, possibly indicating additional or more efficient shallow heat sources in its crust.

  12. A strongly heated neutron star in the transient z source MAXI J0556-332

    Energy Technology Data Exchange (ETDEWEB)

    Homan, Jeroen; Remillard, Ronald A. [MIT Kavli Institute for Astrophysics and Space Research, 77 Massachusetts Avenue 37-582D, Cambridge, MA 02139 (United States); Fridriksson, Joel K.; Wijnands, Rudy [Anton Pannekoek Institute for Astronomy, University of Amsterdam, Postbus 94249, 1090 GE Amsterdam (Netherlands); Cackett, Edward M. [Department of Physics and Astronomy, Wayne State University, 666 W. Hancock St., Detroit, MI 48201 (United States); Degenaar, Nathalie [Department of Astronomy, University of Michigan, 500 Church Street, Ann Arbor, MI 48109 (United States); Linares, Manuel [Instituto de Astrofísica de Canarias, c/ Vía Láctea s/n, E-38205 La Laguna, Tenerife (Spain); Lin, Dacheng, E-mail: jeroen@space.mit.edu [Space Science Center, University of New Hampshire, Durham, NH 03824 (United States)

    2014-11-10

    We present Chandra, XMM-Newton, and Swift observations of the quiescent neutron star in the transient low-mass X-ray binary MAXI J0556-332. Observations of the source made during outburst (with the Rossi X-ray Timing Explorer) reveal tracks in its X-ray color-color and hardness-intensity diagrams that closely resemble those of the neutron-star Z sources, suggesting that MAXI J0556-332 had near- or super-Eddington luminosities for a large part of its ∼16 month outburst. A comparison of these diagrams with those of other Z sources suggests a source distance of 46 ± 15 kpc. Fits to the quiescent spectra of MAXI J0556-332 with a neutron-star atmosphere model (with or without a power-law component) result in distance estimates of 45 ± 3 kpc, for a neutron-star radius of 10 km and a mass of 1.4 M {sub ☉}. The spectra show the effective surface temperature of the neutron star decreasing monotonically over the first ∼500 days of quiescence, except for two observations that were likely affected by enhanced low-level accretion. The temperatures we obtain for the fits that include a power law (kT{sub eff}{sup ∞} = 184-308 eV) are much higher than those seen for any other neutron star heated by accretion, while the inferred cooling (e-folding) timescale (∼200 days) is similar to other sources. Fits without a power law yield higher temperatures (kT{sub eff}{sup ∞} = 190-336 eV) and a shorter e-folding time (∼160 days). Our results suggest that the heating of the neutron-star crust in MAXI J0556-332 was considerably more efficient than for other systems, possibly indicating additional or more efficient shallow heat sources in its crust.

  13. Performance tests of air source heat pumps under frosting conditions. Quality of results

    Science.gov (United States)

    Fahlen, P.

    This report focuses on the analysis of uncertainties in research regarding air-source heat pumps. The principles recommended by the Western European Calibration Conference (WECC) are applied and the generated information is condensed in the form of uncertainty budgets. The ensuring discussion, and the Measurement Assurance Program that was applied during the research work are also relevant to general testing of cooling coils, e.g. for air source heat pumps. The general conclusion of the analysis is that the method of determining frost mass by continuous weighing and frost density by inference from pressure drop considerations, which is presented in the report, has the potential to produce results with an accuracy on a par with the best previously used techniques to investigate frosting and defrosting phenomena. Furthermore, the methodology has the distinct advantage of yielding online measuring possibilities and being much less time consuming than traditional techniques.

  14. Organic Rankine-cycle turbine power plant utilizing low temperature heat sources

    Science.gov (United States)

    Maizza, V.

    1980-03-01

    Utilizing and converting of existing low temperature and waste heat sources by the use of a high efficiency bottoming cycle is attractive and should be possible for many locations. This paper presents a theoretical study on possible combination of an organic Rankine-cycle turbine power plate with the heat pump supplied by waste energy sources. Energy requirements and system performances are analyzed using realistic design operating condition for a middle town. Some conversion systems employing working fluids other than water are being studied for the purpose of proposed application. Thermodynamic efficiencies, with respect to available resource, have been calculated by varying some system operating parameters at various reference temperature. With reference to proposed application equations and graphs are presented which interrelate the turbine operational parameters for some possible working fluids with computation results.

  15. Temperature distribution of air source heat pump barn with different air flow

    Science.gov (United States)

    He, X.; Li, J. C.; Zhao, G. Q.

    2016-08-01

    There are two type of airflow form in tobacco barn, one is air rising, the other is air falling. They are different in the structure layout and working principle, which affect the tobacco barn in the distribution of temperature field and velocity distribution. In order to compare the temperature and air distribution of the two, thereby obtain a tobacco barn whose temperature field and velocity distribution are more uniform. Taking the air source heat pump tobacco barn as the investigated subject and establishing relevant mathematical model, the thermodynamics of the two type of curing barn was analysed and compared based on Fluent. Provide a reasonable evidence for chamber arrangement and selection of outlet for air source heat pump tobacco barn.

  16. Performance prediction between horizontal and vertical source heat pump systems for greenhouse heating with the use of artificial neural networks

    Science.gov (United States)

    Benli, Hüseyin

    2016-08-01

    This paper presents the suitability of artificial neural networks (ANNs) to predict the performance and comparison between a horizontal and a vertical ground source heat pump system. Performance forecasting is the precondition for the optimal control and energy saving operation of heat pump systems. In this study, performance parameters such as air temperature entering condenser fan-coil unit, air temperature leaving condenser fan-coil unit, and ground temperatures (2 and 60 m) obtained experimental studies are input data; coefficient of performance of system (COPsys) is in output layer. The back propagation learning algorithm with three different variants such as Levenberg-Marguardt, Pola-Ribiere conjugate gradient, and scaled conjugate gradient, and also tangent sigmoid transfer function were used in the network so that the best approach can be found. The results showed that LM with three neurons in the hidden layer is the most suitable algorithm with maximum correlation coefficients R2 of 0.999, minimum root mean square RMS value and low coefficient variance COV. The reported results confirmed that the use of ANN for performance prediction of COPsys,H-V is acceptable in these studies.

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

    Directory of Open Access Journals (Sweden)

    Pydych Tadeusz

    2017-01-01

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

  18. A new power generation method utilizing a low grade heat source

    Institute of Scientific and Technical Information of China (English)

    Wei-feng WU; Kin-ping LONG; Xiao-ling YU; Quan-ke FENG

    2012-01-01

    Energy crisis make the effective use of low grade energy more and more urgent.It is still a worldwide difficult conundrum.To efficiently recover low grade heat,this paper deals with a theoretical analysis of a new power generation method driven by a low grade heat source.When the temperature of the low grade heat source exceeds the saturated temperature,it can heat the liquid into steam.If the steam is sealed and cooled in a container,it will lead to a negative pressure condition.The proposed power generation method utilizes the negative pressure condition in the sealed container,called as a condensator.When the condensator is connected to a liquid pool,the liquid will be pumped into it by the negative pressure condition.After the condensator is filled by liquid,the liquid flows back into the pool and drives the turbine to generate electricity.According to our analysis,for water,the head pressure of water pumped into the condensator could reach 9.5 m when the temperature of water in the pool is 25 ℃,and the steam temperature is 105 ℃.Theoretical thermal efficiency of this power generation system could reach 3.2% to 5.8% varying with the altitude of the condensator to the water level,ignoring steam leakage loss.

  19. Finite line-source model for borehole heat exchangers. Effect of vertical temperature variations

    Energy Technology Data Exchange (ETDEWEB)

    Bandos, Tatyana V.; Fernandez, Esther; Santander, Juan Luis G.; Isidro, Jose Maria; Perez, Jezabel; Cordoba, Pedro J. Fernandez de [Instituto Universitario de Matematica Pura y Aplicada, Universidad Politecnica de Valencia, Camino de Vera s/n, 46022 Valencia (Spain); Montero, Alvaro; Urchueguia, Javier F. [Instituto de Ingenieria Energetica, Universidad Politecnica de Valencia, Camino de Vera s/n, 46022 Valencia (Spain)

    2009-06-15

    A solution to the three-dimensional finite line-source (FLS) model for borehole heat exchangers (BHEs) that takes into account the prevailing geothermal gradient and allows arbitrary ground surface temperature changes is presented. Analytical expressions for the average ground temperature are derived by integrating the exact solution over the line-source depth. A self-consistent procedure to evaluate the in situ thermal response test (TRT) data is outlined. The effective thermal conductivity and the effective borehole thermal resistance can be determined by fitting the TRT data to the time-series expansion obtained for the average temperature. (author)

  20. Combined Cycle for Power Generation and Refrigeration Using Low Temperature Heat Sources

    OpenAIRE

    Vijay Chauhan; P. Anil Kishan; Sateesh Gedupudi

    2014-01-01

    A combined refrigeration and power cycle, which uses ammonia-water as the working fluid, is proposed by combining Rankine and vapour absorption cycles with an advantage of varying refrigeration capacity to power output ratio. The study investigates the usage of low temperature heat sources for the cycle operation. Results of parametric analysis are presented, which show the scope for optimization. Results of thermodynamic optimization of the cycle for second law efficiency performed using gen...

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

    Energy Technology Data Exchange (ETDEWEB)

    Menart, James A. [Wright State University

    2013-02-22

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

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

    Energy Technology Data Exchange (ETDEWEB)

    James A Menart, Professor

    2013-02-22

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

  3. Geometric Characteristics of Methane Steam Reforming with Low Temperature Heat Source

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Gahui; Yun, Jinwon; Yu, Sangseok [Chungnam Nat’l Univ., Daejeon (Korea, Republic of)

    2016-12-15

    In a hybrid fuel cell system, low-temperature reforming technology, which uses waste heat as a heat source, is applied to improve system efficiency. A low temperature reformer is required to optimize geometry in low thermal conditions so that the reformer can achieve the proper methane conversion rate. This study analyzed internal temperature distributions and the reaction patterns of a reformer by considering the change of the shape factor on the limited heat supply condition. Unlike the case of a high temperature reformer, analysis showed that the reaction of a low temperature reformer takes place primarily in the high temperature region of the reactor exit. In addition, it was confirmed that the efficiency can be improved by reducing the GHSV (gas hourly space velocity) or increasing the heat transfer area in the radial direction. Through reacting characteristic analysis, according to change of the aspect ratio, it was confirmed that a low temperature reformer can improve the efficiency by increasing the heat transfer in the radial direction, rather than in the longitudinal direction.

  4. Model for the heat source of the Cerro Prieto magma-hydrothermal system, Baja California, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Elders, W.A.; Bird, D.K.; Williams, A.E.; Schiffman, P.; Cox, B.

    1981-01-01

    Earlier studies at Cerro Prieto led to the development of a qualitative model for fluid flow in the geothermal system before it was drilled and perturbed by production. Current efforts are directed towards numerical modeling of heat and mass transfer in the system in this undisturbed state. This one-dimensional model assumes that the heat source was a single basalt/gabbro intrusion which provided heat to the system as it cooled. After compilation of various information of the physical properties of the reservoir, the enthalpy contained in two 1 cm thick sections across the reservoir orthogonal to each other was calculated. Various shapes, sizes and depths for the intrusion were considered as initial conditions and boundary conditions for the calculations of heat transfer. A family of numerical models which so far gives the best matches to the conditions observed in the field today have in common a funnel-shaped intrusion with a top 4 km wide emplaced at a depth of 5 km some 30,000 to 50,000 years ago, providing heat to the geothermal system.

  5. A strong shallow heat source in the accreting neutron star MAXI J0556-332

    CERN Document Server

    Deibel, Alex; Brown, Edward F; Page, Dany

    2015-01-01

    An accretion outburst in an X-ray transient deposits material onto the neutron star primary; this accumulation of matter induces reactions in the neutron star's crust. During the accretion outburst these reactions heat the crust out of thermal equilibrium with the core. When accretion halts, the crust cools to its long-term equilibrium temperature on observable timescales. Here we examine the accreting neutron star transient MAXI J0556-332, which is the hottest transient, at the start of quiescence, observed to date. Models of the quiescent light curve require a large deposition of heat in the shallow outer crust from an unknown source. The additional heat injected is $\\approx 4\\textrm{-}10\\,\\mathrm{MeV}$ per accreted nucleon; when the observed decline in accretion rate at the end of the outburst is accounted for, the required heating increases to $\\approx 6\\textrm{-}16\\,\\mathrm{MeV}$. This shallow heating is still required to fit the lightcurve even after taking into account a second accretion episode, uncer...

  6. Construction Technology of Soil Source Heat Exchanger of Ground Source Heat Pump%地源热泵土壤源换热器的施工技术

    Institute of Scientific and Technical Information of China (English)

    程金明; 王巧真

    2007-01-01

    地源热泵(Ground Source Heat Pump, GSHP)作为最有发展潜力的热泵技术在各级政府的积极推介下发展迅速,但由于地源换热器施工安装成本高,技术的发展遇到了很大的阻力.探讨了土壤源换热器施工技术和土壤源换热器的热平衡问题,力图提高土源换热器施工技术,降低地源热泵成本,促进该技术的推广应用.

  7. Analysis of Magnetic Field Effects on Distributed Heat Sources in a Nanofluid-Filled Enclosure by Natural Convection

    Directory of Open Access Journals (Sweden)

    Alireza Aghaei

    2016-01-01

    Full Text Available This paper studies the effect of magnetic field on the flow field and heat transfer of nanofluid with variable properties in the square enclosure with two arrangements of heat sources. Based upon numerical predictions, the effects of pertinent parameters such as the Rayleigh number (103, 104 and 105, the Hartmann number (0, 25, 50, 75 and 100 and the solid volume fraction (0 to 4% on the flow and temperature fields and the heat transfer performance of the enclosure are examined. For the numerical solution of conservation equations, finite volume method and SIMPLER algorithm was used. The results show that the heat transfer rate influenced by district heat sources and it increases with distributing heat sources on the side walls and it increases with an increase of the Rayleigh number and volume fraction, but decreases with an increase of Hartmann number.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2017-07-01

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

  9. Optimization of systems with the combination of ground-source heat pump and solar collectors in dwellings

    DEFF Research Database (Denmark)

    Kjellsson, Elisabeth; Hellström, Göran; Perers, Bengt

    2010-01-01

    The use of ground-source heat pumps for heating and domestic hot water in dwellings is common in Sweden. The combination with solar collectors has been introduced to reduce the electricity demand in the system. In order to analyze different systems with combinations of solar collectors and ground......-source heat pumps, computer simulations have been carried out with the simulation program TRNSYS. Large differences were found between the system alternatives. The optimal design is when solar heat produces domestic hot water during summertime and recharges the borehole during wintertime. The advantage...... is related to the rate of heat extraction from the borehole as well as the overall design of the system. The demand of electricity may increase with solar recharging, because of the increased operating time of the circulation pumps. Another advantage with solar heat in combination with heat pumps is when...

  10. Effect of heat radiation in a Walter’s liquid B fluid over a stretching sheet with non-uniform heat source/sink and elastic deformation

    Directory of Open Access Journals (Sweden)

    A.K. Abdul Hakeem

    2014-07-01

    Full Text Available In this present article heat transfer in a Walter’s liquid B fluid over an impermeable stretching sheet with non-uniform heat source/sink, elastic deformation and radiation are reported. The basic boundary layer equations for momentum and heat transfer, which are non-linear partial differential equations, are converted into non-linear ordinary differential equations by means of similarity transformation. The dimensionless governing equations for this investigation are solved analytically using hyper geometric functions. The results are carried out for prescribed surface temperature (PST and prescribed power law surface heat flux (PHF. The effects of viscous dissipation, Prandtl number, Eckert number, heat source/sink parameter with elastic deformation and radiation are shown in the several plots and addressed.

  11. Characterizing open and non-uniform vertical heat sources: towards the identification of real vertical cracks in vibrothermography experiments

    Science.gov (United States)

    Castelo, A.; Mendioroz, A.; Celorrio, R.; Salazar, A.; López de Uralde, P.; Gorosmendi, I.; Gorostegui-Colinas, E.

    2017-05-01

    Lock-in vibrothermography is used to characterize vertical kissing and open cracks in metals. In this technique the crack heats up during ultrasound excitation due mainly to friction between the defect's faces. We have solved the inverse problem, consisting in determining the heat source distribution produced at cracks under amplitude modulated ultrasound excitation, which is an ill-posed inverse problem. As a consequence the minimization of the residual is unstable. We have stabilized the algorithm introducing a penalty term based on Total Variation functional. In the inversion, we combine amplitude and phase surface temperature data obtained at several modulation frequencies. Inversions of synthetic data with added noise indicate that compact heat sources are characterized accurately and that the particular upper contours can be retrieved for shallow heat sources. The overall shape of open and homogeneous semicircular strip-shaped heat sources representing open half-penny cracks can also be retrieved but the reconstruction of the deeper end of the heat source loses contrast. Angle-, radius- and depth-dependent inhomogeneous heat flux distributions within these semicircular strips can also be qualitatively characterized. Reconstructions of experimental data taken on samples containing calibrated heat sources confirm the predictions from reconstructions of synthetic data. We also present inversions of experimental data obtained from a real welded Inconel 718 specimen. The results are in good qualitative agreement with the results of liquids penetrants testing.

  12. Mission design study of an RTG powered, ion engine equipped interstellar spacecraft

    Science.gov (United States)

    Fogel, Joshua A.

    This research explores a variety of mission and system architectures for an unmanned Interstellar Precursor Mission (IPM) spacecraft with a Radioisotope Thermoelectric Generator (RTG) powered Ion Engine using Xenon propellant, traveling on a (direct) ballistic escape trajectory to the undisturbed Interstellar Medium (˜200 AU). The main goal of this work was to determine the relationship between the propulsion system design parameters and the ensuing escape trajectory. To do this, an orbit simulator was created in Matlab using a fourth order Runge-Kutta numerical integration method to propagate the thrusting spacecraft's trajectory through time. The accelerations due to the Sun's gravity and the Ion Engine thrust were modeled separately and then combined into a single total acceleration vector at each time step, with the thrust direction assumed to be in the direction of the spacecraft's instantaneous velocity vector. The propellant of the thruster was also designed to be completely consumed by the time of engine cut-off (ECO), meaning a constant propellant mass flow rate. Simulations were run for burn times of 5, 10 & 15 years, with heliocentric launch velocities of 0, 5, 7, 10 & 12 km/sec from a circular 1 AU Earth orbit, and with RTG supplied engine input powers of 1000, 1500 & 2000 W. A total of 45 simulations were run for the circular 1 AU case, as well as additional comparison simulations for launches from an elliptical Earth orbit at perihelion and aphelion. The results of these simulations yielded many interesting results on the total fly-out times to 200 AU, which ranged dramatically from ˜35 to ˜140 years depending on the propulsion system settings and orbital initial conditions, as well as descriptions of the ECO distances from the Sun for each mission. The simulations also revealed the inherent gravitational maneuver inefficiency felt by all low thrust spacecraft, which becomes more apparent under certain conditions. Relations between launch velocity

  13. Existing climate data sources and Their Use in Heat IslandResearch

    Energy Technology Data Exchange (ETDEWEB)

    Akbari, Hashem; Pon, Brian; Smith, Craig Kenton; Stamper-Kurn, Dan Moses

    1998-10-01

    Existing climate data sources can be used in two general types of analysis for the detection of urban heat islands. Historical analyses use long-term data records-preferentially from several locations in and around an urban area-to trace the gradual influence of urban development on its climate. Primary sources of such data include the cooperative network, first-order National Weather Service stations, and military weather stations. Analyses of short-term data use information from a dense urban weather station network to discern the location, extent, and magnitude of urban heat islands. Such analyses may use the aforementioned national networks or regional networks such as agricultural, air quality monitoring, or utility networks. We demonstrate the use of existing data sources with a historical analysis of temperature trends in Los Angeles, California, and an analysis of short-term data of the urban temperature profile for Phoenix, Arizona. The Los Angeles climate was examined with eleven long-term data records from the cooperative network. Statistically significant trends of rising temperature were detected at Los Angeles Civic Center and other stations over some parts of the year, although timing of the increase varied from station to station. Observed increases in temperatures maybe due to long-term climate changes, microclimate influences, or local-scale heat islands. The analysis of short-term data was made for Phoenix using the PRISMS station network. Mean diurnal temperature profiles for a month were examined and compared with those for adjacent rural areas. Data fi-om stations in the center of Phoenix showed clear and significant nighttime and daytime temperature differences of 1- 2K (3 - 4"F). These temperature increases maybe attributable to a local-scale heat island.

  14. A critical evaluation of semianalytic methods in the study of centrally heated, unresolved, infrared sources

    Science.gov (United States)

    Doty, Steven D.; Leung, Chun Ming

    1994-01-01

    We critically evaluate current methods of analysis in infrared (IR) astronomy and investigate the conditions under which these semianalytic methods are reliable. Specifically we examine the usual assumptions of homogeneities in dust density and temperature, and neglect of opacity effects when applied to internally heated, unresolved IR sources. To accomplish this, a series of radiation transport models for these sources have been constructed. The model results are treated as observed quantities and analyzed to derive the source parameters, using simple semianalytic methods. The discrepancies between the derived and actual model parameters can then be attributed to the limitations of the analysis methods and provide a measure of their reliability. Applying this approach to centrally heated, unresolved IR sources, we have studied in detail the following diagnostic problems: (1) determination of dust mass from monochromatic and integrated luminosities; (2) estimation of dust temperature distribution from color temperatures derived from the flux spectrum; and (3) determination of the empirical grain emissivity law (opacity function) for both continuum and spectral features.

  15. Enhanced primary sludge sonication by heat insulation to reclaim carbon source for biological phosphorous removal.

    Science.gov (United States)

    Tian, Qing; Wang, Qi; Zhu, Yanbing; Li, Fang; Zhuang, Lin; Yang, Bo

    2017-01-01

    Ultrasound pretreatment is a potent step to disintegrate primary sludge (PS). The supernatant of sonicated PS is recycled as an alternative carbon source for biological phosphorus removal. In this study, we investigated the role of temperature on PS disintegration during sonication. We found that a temperature of 60°C yielded a dissolution rate of about 2% soluble chemical oxygen demand (SCOD) as compared to 7% SCOD using sonication at the specific energy (SE) of 7359kJ/kg TS. Using the SE of 6000kJ/kg TS with heat insulation during sonication, the SCOD dissolution rate of PS was similar to the result at the SE of 7051kJ/kg TS without heat insulation. Upon treatment with sonication, the PS released low concentrations of Cu and Zn into the supernatant. The phosphorus-accumulating organisms (PAOs) used the supernatant of sonicated PS as the carbon source. Supplementation with the diluted sonicated PS supernatant (SCOD≈1000mg/L) in anaerobic phase resulted in the release of phosphorus (36mg/L) and the production of polyhydroxyalkanoates (PHAs) (0.36g PHA/g SS). Compared with sodium acetate, higher polyhydroxyvalerate (PHV) faction in the polyhydroxyalkanoates (PHAs) was observed in the biomass when incubated with sonicated PS as the carbon source. This work provides a simple pathway to conserve energy and to enhance efficiencies of ultrasonic pretreatment and the recovery of carbon source from the sludge for improving the phosphorus removal in the ENR system.

  16. The feasibility of retrieving nuclear heat sources from orbit with the space shuttle

    Energy Technology Data Exchange (ETDEWEB)

    Pyatt, D.W.; Englehart, R.W.

    1980-01-01

    Spacecraft launched for orbital missions have a finite orbital lifetime. Current estimates for the lifetime of the nine nuclear powered U.S. satellites now in orbit range from 150 years to 10{sup 6} years. Orbital lifetime is determined primarily by altitude, solar activity, and the satellite ballistic coefficient. There is also the potential of collision with other satellites or space debris, which would reduce the lifetime in orbit. These orbiting power sources contain primarily Pu-238 and Pu-239 as the fuel material. Pu-238 has an approximate 87-year half life and so considerable amounts of daughter products are present after a few tens of years. In addition, there are minor but possibly significant amounts of impurity isotopes present with their own decay chains. Radioisotopic heat sources have been designed to evolving criteria since the first launches. Early models were designed to burn up upon reentry. Later designs were designed to reenter intact. After tens or hundreds of years in orbit, the ability of any orbiting heat source to reenter intact and impact while maintaining containment integrity is in doubt. Such ability could only be verified by design to provide protection in the case of early mission failures such as launch aborts, failure to achieve orbit, or the attainment of only a short orbit. With the development of the Space Shuttle there exists the potential ability to recover heat sources in orbit after their missions are completed. Such retrieval could allow the risk of eventual reentry burnup or impact with atmospheric dispersion and subsequent radiation doses to the public to be avoided.

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

    Energy Technology Data Exchange (ETDEWEB)

    Im, Piljae [ORNL; Liu, Xiaobing [ORNL

    2015-09-01

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

  18. Focus group discussions among owners and non-owners of ground source heat pumps

    Energy Technology Data Exchange (ETDEWEB)

    Roberson, B.F.

    1988-07-01

    This research was sponsored by the Office of Buildings and Community Systems and conducted by the Pacific Northwest Laboratory as part of an ongoing effort to enhance the commercial use of federally developed technology. Federal dollars have supported research on the development of ground source heat pumps (GSHP) for several years. Though several companies currently sell GSHP's for residential use, their share of the total heating and air conditioning business remains less than one percent. Large manufacturing companies with national distribution have not yet added GSHP equipment to their product line. GSHP's use only about one half (Braud 1987) to one third (Bose 1987) of the energy needed to operate conventional furnaces and air conditioners. Consequently, a high level of market penetration by the GSHP offers direct benefits to both utility companies and individual users of the systems. Widespread use of these highly efficient systems will reduce both total energy consupmtion, and problems associated with high levels of energy use during peak periods. This will allow utility companies to delay capital expenditures for new facilities to meet the growing energy demand during peak periods. The cost effective use of electricity also reduces the likelihood of homeowners switching to a different fuel source for heating. 5 refs.

  19. Preliminary analysis on the relationships between Tibetan Plateau NDVI change and its surface heat source and precipitation of China

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Using the automatic weather station data obtained from the Tibetan Plateau (TP), the normalized dif- ference vegetation index and the monthly precipitation data of China and by the methods of correlation and composite analysis, preliminary analytical results are achieved concerning the relationships be- tween TP NDVI change and its surface heat source and precipitation of China. The results of our re- search may lead to the following conclusions: (1) A positive correlation relationship exists between TP NDVI change and its surface heat source, including the sensible heat and the latent heat. As to the correlation of the former, it is more remarkable in western TP than in eastern TP, and as to the correla- tion of the latter, however it turns out contrary. (2) With the improvement of TP vegetation, its surface heat source of every season is also mainly reinforced, especially in summer. As to the contribution of the sensible heat and the latent heat to the increment of the TP surface heat source intensity, the for- mer is comparatively more significant than the latter in winter and spring, while in summer and autumn, the two have almost the same importance. (3) The correlation coefficient between summer NDVI over TP and the corresponding period precipitation of China displays a belt distribution of "+?+" from south to north China. (4) Anomalous surface heating field over TP derived from vegetation change is probably an important factor to affect summer precipitation of China.

  20. 太阳能-空气复合热源热泵热水系统%Solar-air composite heat source heat pump hot water system

    Institute of Scientific and Technical Information of China (English)

    王岗; 全贞花; 赵耀华; 侯隆澍; 徐俊芳; 邓月超

    2014-01-01

    In the light of low efficiency of photovoltaic power generation and the problems of air source heat pump applied in cold regions, a composite heat exchanger evaporator is developed and a new type of solar-air composite heat source heat pump hot water system is designed in this study, which is comprised of independent solar photovoltaic-thermal collector based on flat plate micro heat pipe and air source heat pump. The performance of heat pump hot water system is evaluated experimentally under different operating conditions, including water temperature of the tank, heating time of hot water, suction and discharge pressure, consumption of compressor power and heat pump coefficient of performance (COP), etc. Experimental results show that at ambient temperature of 5℃, 10℃ and 15℃, with 73 L hot water heated by heat pump and water temperature in the tank ranged from 15℃ to 50℃, the running time of composite heat source operation is shorter than that of separate air heat source operation, decreased by 5.14%, 10.29% and 11.38%, respectively. COPs are increased by 5.99%, 9.28%and 11.96%, respectively.%针对光伏发电效率较低和空气源热泵在寒冷地区应用中存在的问题,研发了一种新型复合蒸发器,将平板微热管阵列太阳能光伏光热(PV/T)集热器与空气源热泵相结合,组成新型太阳能-空气复合热源热泵热水系统。并对该热水系统在不同运行工况下的水箱水温、吸排气压力、压缩机功率和性能等进行了实验研究。实验结果表明,在环境温度分别为5、10和15℃的条件下,热泵加热73 L水,水温从15℃加热到50℃时,双热源运行工况的加热时间比单空气热源运行工况依次缩短了5.14%、10.29%和11.38%,COP依次提高了5.99%、9.28%和11.96%。

  1. Operation of a microwave plasma source for electron heating and antenna testing

    Science.gov (United States)

    Caughman, J. B. O.; Bigelow, T. S.; Diem, S. J.; Goulding, R. H.; Rasmussen, D. A.; Schaich, C. R.; White, T. L.

    2011-10-01

    One of the major challenges for magnetic fusion is the interaction of the plasma with materials. Linear plasma-material interaction test stands can benefit from additional electron heating of the high-density source plasma to increase the total plasma heat flux at the target to better simulate fusion reactor conditions (10-20 MW/m2). A microwave-based plasma experiment has begun at ORNL to study electron heating of over-dense plasmas and to provide a plasma environment for antenna testing. The plasma is generated by high-field launched whistler waves at 18 GHz to create a moderate-density plasma (ne ~1018/m3). Electron heating of the over-dense plasma is provided by either whistler waves or electron Bernstein waves at 6 GHz. In addition, a single strap mockup antenna, designed to operate at 40-50 MHz, is being constructed to study near-field plasma interactions. The antenna will be placed in the experiment's central vacuum chamber, which will act as an rf test facility. ORNL is managed by UT-Battelle, LLC, for the U.S. DOE under contract DE-AC-05-00OR22725.

  2. Transient natural ventilation of a room with a distributed heat source

    Science.gov (United States)

    Fitzgerald, Shaun D.; Woods, Andrew W.

    We report on an experimental and theoretical study of the transient flows which develop as a naturally ventilated room adjusts from one temperature to another. We focus on a room heated from below by a uniform heat source, with both high- and low-level ventilation openings. Depending on the initial temperature of the room relative to (i) the final equilibrium temperature and (ii) the exterior temperature, three different modes of ventilation may develop. First, if the room temperature lies between the exterior and the equilibrium temperature, the interior remains well-mixed and gradually heats up to the equilibrium temperature. Secondly, if the room is initially warmer than the equilibrium temperature, then a thermal stratification develops in which the upper layer of originally hot air is displaced upwards by a lower layer of relatively cool inflowing air. At the interface, some mixing occurs owing to the effects of penetrative convection. Thirdly, if the room is initially cooler than the exterior, then on opening the vents, the original air is displaced downwards and a layer of ambient air deepens from above. As this lower layer drains, it is eventually heated to the ambient temperature, and is then able to mix into the overlying layer of external air, and the room becomes well-mixed. For each case, we present new laboratory experiments and compare these with some new quantitative models of the transient flows. We conclude by considering the implications of our work for natural ventilation of large auditoria.

  3. 浙北地区地源热泵土壤换热性能测试研究%Study on Measurement of Heat Transfer Characteristics of Ground Source in a Ground Source Heat Pump System in Northern Zhejiang

    Institute of Scientific and Technical Information of China (English)

    刘晓勤; 郑锦龙; 郑翀

    2011-01-01

    The heat transfer characteristics of ground source in Ground Source Heat Pump (GSHP) in Northem Zhejiang were experimentally measured. The experimental results showed that the initial ground source temperature in the coldest month was approximately 17.0℃, which was significantly higher than the temperature of the outside environment. The mean thermal conductivity of the ground source was 1.73W/(m· ℃). It indicated that the ground source had good heat transfer capacity and could be used for the ground source heat pump system. The experimental measurement of the heat transfer coefficient was also conducted on a single U type underground heat exchanger at the depth of 60 m. The experimental results showed that the heat dissipating capacity of the single pipe were 3666W in summer and 2508 W in winter, respectively. The heat dissipating capacity could meet the requirement of the ground source heat pump system.%对浙北地区某地源热泵工程土壤换热性能进行了实验测试,结果显示,浙北地区冬季最冷月地下土壤初始温度稳定在17.0℃左右,远高于室外环境温度;土壤的平均导热系数为1.73W/(m·℃),有较强的地下换热能力,适合做地源热泵系统;对60m深的单U形式地下换热器进行换热性能测试,夏季单根盘管散热量3666W,冬季单根盘管散热量2508W,能满足系统工作要求。

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

    Science.gov (United States)

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

    2016-06-01

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

  5. Control strategy research of variable flow at heat source side for water source heat pump%水源热泵系统热源侧变流量控制策略研究

    Institute of Scientific and Technical Information of China (English)

    蒋小强; 龙惟定; 李敏

    2012-01-01

    分析水源热泵系统供热运行的技术经济性.建立适用于TRNSYS软件模拟的水源热泵系统模型,针对不同水源温度通过改变热源侧水流量方式优化运行.比较水源热泵系统、燃气和燃油3种供热方式的运行经济性,结果表明,不同水源温度下的最佳供热方式不同.%Technical economy analysis of water source heat pump system is done in heating operation. The model of water source heat pump is established at TRNSYS platform, the optimal operation under different temperature of source water are carried by changing the water flow of heat source side. The running economy of heating by wate soure heat pump system, the combustion gas or oil is compared, the best heating mode is obtained at different water source temperature.

  6. Study of heat sources interacting in integrated circuits by laser mirage effect

    Energy Technology Data Exchange (ETDEWEB)

    Perpiñà, X.; Jordà, X.; Vellvehi, M. [Centre Nacional de Microelectrònica IMB-CNM (CSIC), Campus UAB, 08193 Bellaterra (Barcelona) (Spain); Altet, J. [Departament d' Enginyeria Electrònica, Universitat Politècnica de Catalunya, Barcelona 08034 (Spain)

    2014-08-25

    This work exploits the mirage effect to analyze multiple heat sources thermally interacting in an integrated circuit (IC) by means of a probe IR laser beam, which strikes on the die lateral walls and passes through the die substrate. Under such conditions, the criteria for locating such hot spots, as well as their relative power dissipation, are discussed on the basis of a theoretical model inferred in this work. Finally, the technique feasibility is shown in a real application scenario, obtaining 5-μm spatial lateral resolution and an error in power dissipation measurements below 5%. This method may become a practical alternative to usual off-chip techniques for inspecting hot spots in ICs and to experimentally characterize heat flow in the semiconductor substrate.

  7. Introduction of renewable energy sources in the district heating system of Greece

    Directory of Open Access Journals (Sweden)

    Nikolaos Margaritis

    2016-06-01

    Full Text Available The district heating (DH system of Greece, mainly supported from lignite fired stations, is facing lately significant challenges. Stricter emission limits, decreased efficiency due to old age and increased costs are major challenges of the lignite sector and are expected to result in the decommissioning of several lignite-fired units in the coming years. As a result, managers of DH networks are currently investigating alternative scenarios for the substitution of thermal power that it is expected to be lost, through the integration of Renewable Energy Sources (RES into the system. In this paper, the DH systems of Kozani and Ptolemaida are examined regarding possible introduction of RES. The first study examines district heating of Kozani and alternative future options for covering a part of city’s thermal load whereas the second study refers to a biomass CHP plant (ORC technology, 1MWe, 5MWth to be powered from a biomass mixture (wood chips and straw.

  8. Investment and Economy Analysis of Water-Source Heat Pump System in Chongqing, China

    Directory of Open Access Journals (Sweden)

    Yong Ding

    2013-01-01

    Full Text Available In China, the application of renewable energy witnesses rapid development. In the near future, a lot of demonstration projects will be built and thus it is urgent to know the economics of renewable energy building application technologies. Based on the renewable energy demonstration projects in Chongqing city, the author discussed the economy issue of water-source heat pump system (WSHPs in order to provide suggestions for the application projects. According to the design information of demonstration projects, the average incremental investment, allowance, and payback period are calculated in this paper. Comparing WSHPs with traditional heating, ventilation, and air conditioning (HVAC system, the saved energy of WSHPs is estimated in the current paper. The author calculated the amount of saved energy in unit applied area and unit intake water. Besides, the economy and efficiency of WSHPs project is analyzed at the end of this paper.

  9. In Situ Measurement of the Undisturbed Ground Temperature for Ground Source Heat Pump System

    Institute of Scientific and Technical Information of China (English)

    ZHOU Ya-su

    2008-01-01

    The undisturbed ground are important for design of the ground heat exchangers in ground source heat pump (GSHP) systems. In this paper, the undisturbed ground temperatures measured in two different methods are presented. The investigation was carried out in two cases. The temperature measured with the direct method is assumed to give the correct undisturbed ground temperature profile. The temperature measured with indirect method overestimates the undisturbed ground temperature by 2.1℃ and 1.7℃. This difference is mainly caused by the circulation pump and ambient air to the fluid. Therefore, the results that are decreased about 2℃ as compared with the indirect measured are recommended to estimate the undisturbed ground temperature in situ measuring. A smaller pump or deeper borehole or mild weather would result in a more correct temperature. Because the undisturbed ground temperature is affected by many factors. Whether or not these conclusions are correct to other areas, this would need further investigation.

  10. Second law analysis of advanced power generation systems using variable temperature heat sources

    Science.gov (United States)

    Bliem, C. J.; Mines, G. L.

    Many systems produce power using variable temperature (sensible) heat sources. The Heat Cycle Research Program is currently investigating the potential improvements to such power cycles utilizing moderate temperature geothermal resources to produce electrical power. It has been shown that mixtures of saturated hydrocarbons (alkanes) or halogenated hydrocarbons operating with a supercritical Rankine cycle gave improved performance over boiling Rankine cycles with the pure working fluids for typical applications. Recently, in addition to the supercritical Rankine Cycle, other types of cycles have been proposed for binary geothermal service. This paper explores the limits on efficiency of a feasible plant and discusses the methods used in these advanced concept plants to achieve the maximum possible efficiency. The advanced plants considered appear to be approaching the feasible limit of performance so that the designer must weigh all considerations to fine the best plant for a given service. These results would apply to power systems in other services as well as to geothermal power plants.

  11. Improved heating efficiency with High-Intensity Focused Ultrasound using a new ultrasound source excitation.

    Science.gov (United States)

    Bigelow, Timothy A

    2009-01-01

    High-Intensity Focused Ultrasound (HIFU) is quickly becoming one of the best methods to thermally ablate tissue noninvasively. Unlike RF or Laser ablation, the tissue can be destroyed without inserting any probes into the body minimizing the risk of secondary complications such as infections. In this study, the heating efficiency of HIFU sources is improved by altering the excitation of the ultrasound source to take advantage of nonlinear propagation. For ultrasound, the phase velocity of the ultrasound wave depends on the amplitude of the wave resulting in the generation of higher harmonics. These higher harmonics are more efficiently converted into heat in the body due to the frequency dependence of the ultrasound absorption in tissue. In our study, the generation of the higher harmonics by nonlinear propagation is enhanced by transmitting an ultrasound wave with both the fundamental and a higher harmonic component included. Computer simulations demonstrated up to a 300% increase in temperature increase compared to transmitting at only the fundamental for the same acoustic power transmitted by the source.

  12. An experimental study of waveguide coupled microwave heating with conventional multicusp negative ion sources

    Energy Technology Data Exchange (ETDEWEB)

    Komppula, J.; Kalvas, T.; Koivisto, H.; Laulainen, J.; Tarvainen, O.

    2015-04-08

    Negative ion production with conventional multicusp plasma chambers utilizing 2.45 GHz microwave heating is demonstrated. The experimental results were obtained with the multicusp plasma chambers and extraction systems of the RF-driven RADIS ion source and the filament driven arc discharge ion source LIISA. A waveguide microwave coupling system, which is almost similar to the one used with the SILHI ion source, was used. The results demonstrate that at least one third of negative ion beam obtained with inductive RF-coupling (RADIS) or arc discharge (LIISA) can be achieved with 1 kW of 2.45 GHz microwave power in CW mode without any modification of the plasma chamber. The co-extracted electron to H{sup −} ratio and the optimum pressure range were observed to be similar for both heating methods. The behaviour of the plasma implies that the energy transfer from the microwaves to the plasma electrons is mainly an off-resonance process.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-12-01

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

  14. Comparative genotoxicity testing of Rhine river sediment extracts using the comet assay with permanent fish cell lines (RTG-2 and RTL-W1) and the Ames test

    Energy Technology Data Exchange (ETDEWEB)

    Kosmehl, T.; Braunbeck, T.; Hollert, H. [Dept. of Zoology, Aquatic Ecology and Toxicology Section, Univ. of Heidelberg (Germany); Krebs, F.; Manz, W. [German Federal Inst. of Hydrology, Koblenz (Germany); Erdinger, L. [Dept. for Hygiene and Medical Microbiology, Inst. for Hygiene, Univ. of Heidelberg (Germany)

    2004-07-01

    Whilst at least in Germany assessment strategies on the basis of chemical analysis and acute toxicity data dominated the last decades, the development of more specific biological endpoints and biomarkers in ecotoxicology is required in order to arrive at a good ecological potential and good chemical status of surface waters in the European river basins until the year 2015, as required by the European Water Framework Directive. Since sediments have for long been known to function both as a sink and as a source of pollutants in aquatic systems, and since part of the particle-associated substances have frequently been demonstrated to cause mutagenic and carcinogenic effects in aquatic organisms, particularly in fish, there is, among other requirements, an urgent need to develop, standardize and implement integrated vertebrate-based test systems addressing genotoxicity into recent sediment investigation strategies. Thus, the present study was designed to compare the suitability of two commonly used test systems, the comet assay and the Ames test, for the evaluation of the ecotoxicological burden of surface and core sediment samples from the river Rhine. Methods (or main features). In order to determine the importance of inherent enzymatic activities, two permanent fish cell lines with different biotransformation capacities, RTL-W1 and RTG-2, were compared with respect to their capability of detecting genotoxic effects in 18 surface and core sediment samples from 9 locations along the river Rhine in the comet assay with and without exogenous bioactivation. For further comparison, as a prokaryotic mutagenicity assay, the Salmonella plate incorporation assay (Ames test) with the test strains TA98 and TA100 with and without exogenous metabolic activation was used. Results and discussion. Whereas all sediment extracts induced genotoxic effects in the comet assay with RTL-W1 cells, only 12 out of 18 sediment extracts revealed significant genotoxicity in the tests with the

  15. Micro- and Nanoscale Energetic Materials as Effective Heat Energy Sources for Enhanced Gas Generators.

    Science.gov (United States)

    Kim, Sang Beom; Kim, Kyung Ju; Cho, Myung Hoon; Kim, Ji Hoon; Kim, Kyung Tae; Kim, Soo Hyung

    2016-04-13

    In this study, we systematically investigated the effect of micro- and nanoscale energetic materials in formulations of aluminum microparticles (Al MPs; heat source)/aluminum nanoparticles (Al NPs; heat source)/copper oxide nanoparticles (CuO NPs; oxidizer) on the combustion and gas-generating properties of sodium azide microparticles (NaN3 MPs; gas-generating agent) for potential applications in gas generators. The burn rate of the NaN3 MP/CuO NP composite powder was only ∼0.3 m/s. However, the addition of Al MPs and Al NPs to the NaN3 MP/CuO NP matrix caused the rates to reach ∼1.5 and ∼5.3 m/s, respectively. In addition, the N2 gas volume flow rate generated by the ignition of the NaN3 MP/CuO NP composite powder was only ∼0.6 L/s, which was significantly increased to ∼1.4 and ∼3.9 L/s by adding Al MPs and Al NPs, respectively, to the NaN3 MP/CuO NP composite powder. This suggested that the highly reactive Al MPs and NPs, with the assistance of CuO NPs, were effective heat-generating sources enabling the complete thermal decomposition of NaN3 MPs upon ignition. Al NPs were more effective than Al MPs in the gas generators because of the increased reactivity induced by the reduced particle size. Finally, we successfully demonstrated that a homemade airbag with a specific volume of ∼140 mL could be rapidly and fully inflated by the thermal activation of nanoscale energetic material-added gas-generating agents (i.e., NaN3 MP/Al NP/CuO NP composites) within the standard time of ∼50 ms for airbag inflation.

  16. Heat Transfer in MHD Dusty Boundary Layer Flow over an Inclined Stretching Sheet with Non-Uniform Heat Source/Sink

    Directory of Open Access Journals (Sweden)

    G. K. Ramesh

    2012-01-01

    Full Text Available This paper presents the study of momentum and heat transfer characteristics in a hydromagnetic flow of dusty fluid over an inclined stretching sheet with non-uniform heat source/sink, where the flow is generated due to a linear stretching of the sheet. Using a similarity transformation, the governing equations of the problem are reduced to a coupled third-order nonlinear ordinary differential equations and are solved numerically by Runge-Kutta-Fehlberg fourth-fifth-order method using symbolic software Maple. Our numerical solutions are shown to agree with the available results in the literature and then employ the numerical results to bring out the effects of the fluid-particle interaction parameter, local Grashof number, angle of inclination, heat source/sink parameter, Chandrasekhar number, and the Prandtl number on the flow and heat transfer characteristics. The results have possible technological applications in liquid-based systems involving stretchable materials.

  17. Effects of thermal radiation and heat transfer over an unsteady stretching surface embedded in a porous medium in the presence of heat source or sink

    Directory of Open Access Journals (Sweden)

    Elsayed M. A Elbashbeshy

    2011-01-01

    Full Text Available The effects of thermal radiation and heat transfer over an unsteady stretching surface embedded in a porous medium in the presence of heat source or sink are studied. The governing time dependent boundary layer equations are transformed to ordinary differential equations containing radiation parameter, permeability parameter, heat source or sink parameter, Prandtl number, and unsteadiness parameter. These equations are solved numerically by applying Nachtsheim-Swinger shooting iteration technique together with Rung-Kutta fourth order integration scheme. The velocity profiles, temperature profiles, the skin friction coefficient, and the rate of heat transfer are computed and discussed in details for various values of the different parameters. Comparison of the obtained numerical results is made with previously published results.

  18. FEM Simulation of Dissimilar Aluminum Titanium Fiber Laser Welding Using 2D and 3D Gaussian Heat Sources

    Directory of Open Access Journals (Sweden)

    Sonia D’Ostuni

    2017-08-01

    Full Text Available For a dissimilar laser weld, the model of the heat source is a paramount boundary condition for the prediction of the thermal phenomena, which occur during the welding cycle. In this paper, both two-dimensional (2D and three-dimensional (3D Gaussian heat sources were studied for the thermal analysis of the fiber laser welding of titanium and aluminum dissimilar butt joint. The models were calibrated comparing the fusion zone of the experiment with that of the numerical model. The actual temperature during the welding cycle was registered by a thermocouple and used for validation of the numerical model. When it came to calculate the fusion zone dimensions in the transversal section, the 2D heat source showed more accurate results. The 3D heat source provided better results for the simulated weld pool and cooling rate.

  19. Ground-Source Integrated Heat Pump for Near-Zero Energy Houses: Technology Status Report

    Energy Technology Data Exchange (ETDEWEB)

    Murphy, Richard W [ORNL; Rice, C Keith [ORNL; Baxter, Van D [ORNL; Craddick, William G [ORNL

    2007-09-01

    . With the greater energy savings the cost of the more energy efficient components required for the IHP can be recovered more quickly than if they were applied to individual pieces of equipment to meet each individual energy service need. An IHP can be designed to use either outdoor air or geothermal resources (e.g., ground, ground water, surface water) as the environmental energy source/sink. Based on a scoping study of a wide variety of possible approaches to meeting the energy service needs for a ZEH, DOE selected the IHP concept as the most promising and has supported research directed toward the development of both air- and ground-source versions. This report describes the ground-source IHP (GS-IHP) design and includes the lessons learned and best practices revealed by the research and development (R&D) effort throughout. Salient features of the GS-IHP include a variable-speed rotary compressor incorporating a brushless direct current permanent magnet motor which provides all refrigerant compression, a variable-speed fan for the indoor section, a multiple-speed ground coil circuit pump, and a single-speed pump for water heating operation. Laboratory IHP testing has thus far used R-22 because of the availability of the needed components that use this refrigerant. It is expected that HFC R-410A will be used for any products arising from the IHP concept. Data for a variable-speed compressor that uses R-410A has been incorporated into the DOE/ORNL Mark VI Heat Pump Design Model (HPDM). HPDM was then linked to TRNSYS, a time-series-dependent simulation model capable of determining the energy use of building cooling and heating equipment as applied to a defined house on a sub-hourly basis. This provided a highly flexible design analysis capability for advanced heat pump equipment; however, the program also took a relatively long time to run. This approach was used with the initial prototype design reported in Murphy et al. (2007a) and in the business case analysis of

  20. ELM simulation experiments on Pilot-PSI using simultaneous high flux plasma and transient heat/particle source

    NARCIS (Netherlands)

    De Temmerman, G.; Zielinski, J. J.; van Diepen, S.; Marot, L.; Price, M.

    2011-01-01

    A new experimental setup has been developed for edge localized mode (ELM) simulation experiments with relevant steady-state plasma conditions and transient heat/particle source. The setup is based on the Pilot-PSI linear plasma device and allows the superimposition of a transient heat/particle pulse

  1. Air-Source Integrated Heat Pump for Near-Zero Energy Houses: Technology Status Report

    Energy Technology Data Exchange (ETDEWEB)

    Murphy, Richard W [ORNL; Rice, C Keith [ORNL; Baxter, Van D [ORNL; Craddick, William G [ORNL

    2007-07-01

    This report documents the development of an air-source integrated heat pump (AS-IHP) through the third quarter of FY2007. It describes the design, analyses and testing of the AS-IHP, and provides performance specifications for a field test prototype and proposed control strategy. The results obtained so far continue to support the AS-IHP being a promising candidate to meet the energy service needs for DOE's development of a Zero Energy Home (ZEH) by the year 2020.

  2. Minimization of operator-balance interactive warmup by use of an alter ego heat source

    Science.gov (United States)

    Braudaway, D. W.

    Operator-equipment interaction is a well-known but frustrating part of many high precision measurements. Deterioration in performance of a high-precision balance required testing to identify the cause of the problem and to establish effectiveness of the solution. An unexpected result of the tests was a clear characterization of a significant operator-balance thermal interaction and verification of the empirically determined warmup requirement. The repeatability of the interactive effect inspired development of a replacement for the operator using an alter ego heat source.

  3. Effect of Thermo-Diffusion and Chemical Reaction on Mixed Convective Heat And Mass Transfer Through A Porous Medium In Cylindrical Annulus With Heat Source.

    Directory of Open Access Journals (Sweden)

    Dr.K.Gnaneswar

    2014-09-01

    Full Text Available A finite element study of combined heat and mass transfer flow through a porous medium in a circular cylindrical annulus with Soret and Dufour effects in the presence of heat sources has been analyzed. The coupled velocity, energy, and diffusion equations are solved numerically by using Galerkin- finite element technique. Shear stress, Nusslet number and Sherwood number are evaluated numerically for different values of the governing parameters under consideration and are shown in tabular form.

  4. The Influence of the Heat Source Temperature on the Multivane Expander Output Power in an Organic Rankine Cycle (ORC System

    Directory of Open Access Journals (Sweden)

    Piotr Kolasiński

    2015-04-01

    Full Text Available Organic Rankine Cycle (ORC power systems are nowadays an option for local and domestic cogeneration of heat and electric power. Very interesting are micropower systems for heat recovery from low potential (40–90 °C waste and renewable heat sources. Designing an ORC system dedicated to heat recovery from such a source is very difficult. Most important problems are connected with the selection of a suitable expander. Volumetric machines, such as scroll and screw expanders, are adopted as turbine alternative in small-power ORC systems. However, these machines are complicated and expensive. Vane expanders on the other hand are simple and cheap. This paper presents a theoretical and experimental analysis of the operation of a micro-ORC rotary vane expander under variable heat source temperature conditions. The main objective of this research was therefore a comprehensive analysis of relation between the vane expander output power and the heat source temperature. A series of experiments was performed using the micropower ORC test-stand. Results of these experiments are presented here, together with a mathematical description of multivane expanders. The analysis presented in this paper indicates that the output power of multivane expanders depend on the heat source temperature, and that multivane expanders are cheap alternatives to other expanders proposed for micropower ORC systems.

  5. X-ray Sources Generated from Gas-Filled Laser-Heated Targets

    Energy Technology Data Exchange (ETDEWEB)

    Back, C A; Grun, J; Decker, C D; Davis, J; Laming, J M; Feldman, U; Suter, L J; Landen, O L; Miller, M; Serduke, F; Wuest, C

    2000-06-06

    The X-ray sources in the 4-7 keV energy regime can be produced by laser-irradiating high-Z gas-filled targets with high-powered lasers. A series of experiments have been performed using underdense targets that are supersonically heated with {approx} 35 W of 0.35 {micro}m laser light. These targets were cylindrical Be enclosures that were filled with 1-2 atms of Xe gas. L-shell x-ray emission is emitted from the plasma and detected by Bragg crystal spectrometers and x-ray diodes. Absolute flux measurements show conversion efficiencies of {approx} 10% in the multi-kilovolt x-ray emission. These sources can be used as bright x-ray backlighters or for material testing.

  6. Preliminary analysis on the relationships between Tibetan Plateau NDVI change and its surface heat source and precipitation of China

    Institute of Scientific and Technical Information of China (English)

    HUA Wei; FAN GuangZhou; ZHOU DingWen; NI ChangJian; LI XueMin; WANG YongLi; LIU YaQin; HUANG XianLun

    2008-01-01

    Using the automatic weather station data obtained from the Tibetan Plateau (TP), the normalized dif-ference vegetation index and the monthly precipitation data of China and by the methods of correlation and composite analysis, preliminary analytical results are achieved concerning the relationships be-tween TP NDVI change and its surface heat source and precipitation of China. The results of our re-search may lead to the following conclusions: (1) A positive correlation relationship exists between TP NDVI change and its surface heat source, including the sensible heat and the latent heat. As to the correlation of the former, it is more remarkable in western TP than in eastern TP, and as to the correla-tion of the latter, however it turns out contrary. (2) With the improvement of TP vegetation, its surface heat source of every season is also mainly reinforced, especially in summer. As to the contribution of the sensible heat and the latent heat to the increment of the TP surface heat source intensity, the for-mer is comparatively more significant than the latter in winter and spring, while in summer and autumn, the two have almost the same importance. (3) The correlation coefficient between summer NDVI over TP and the corresponding period precipitation of China displays a belt distribution of "+-+" from south to north China. (4) Anomalous surface heating field over TP derived from vegetation change is probably an important factor to affect summer precipitation of China.keywords Tibetan Plateau, vegetation change, surface heat source, precipitation of China.

  7. Hybrid Ground-Source Heat Pump Installations: Experiences, Improvements, and Tools

    Energy Technology Data Exchange (ETDEWEB)

    Scott Hackel; Amanda Pertzborn

    2011-06-30

    One innovation to ground-source heat pump (GSHP, or GHP) systems is the hybrid GSHP (HyGSHP) system, which can dramatically decrease the first cost of GSHP systems by using conventional technology (such as a cooling tower or a boiler) to meet a portion of the peak heating or cooling load. This work uses three case studies (two cooling-dominated, one heating-dominated) to demonstrate the performance of the hybrid approach. Three buildings were studied for a year; the measured data was used to validate models of each system. The models were used to analyze further improvements to the hybrid approach, and establish that this approach has positive impacts, both economically and environmentally. Lessons learned by those who design and operate the systems are also documented, including discussions of equipment sizing, pump operation, and cooling tower control. Finally, the measured data sets and models that were created during this work are described; these materials have been made freely available for further study of hybrid systems.

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

    Directory of Open Access Journals (Sweden)

    Wei Wu

    2013-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-09-30

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

  10. Heat Transfer by Thermo-capillary Convection -Sounding Rocket COMPERE Experiment SOURCE

    Science.gov (United States)

    Dreyer, Michael; Fuhrmann, Eckart

    The sounding rocket COMPERE experiment SOURCE was successfully flown on MASER 11, launched in Kiruna (ESRANGE), May 15th, 2008. SOURCE has been intended to partly ful-fill the scientific objectives of the European Space Agency (ESA) Microgravity Applications Program (MAP) project AO-2004-111 (Convective boiling and condensation). Three parties of principle investigators have been involved to design the experiment set-up: ZARM for thermo-capillary flows, IMFT (Toulouse, France) for boiling studies, EADS Astrium (Bremen, Ger-many) for depressurization. The topic of this paper is to study the effect of wall heat flux on the contact line of the free liquid surface and to obtain a correlation for a convective heat trans-fer coefficient. The experiment has been conducted along a predefined time line. A preheating sequence at ground was the first operation to achieve a well defined temperature evolution within the test cell and its environment inside the rocket. Nearly one minute after launch, the pressurized test cell was filled with the test liquid HFE-7000 until a certain fill level was reached. Then the free surface could be observed for 120 s without distortion. Afterwards, the first depressurization was started to induce subcooled boiling, the second one to start saturated boiling. The data from the flight consists of video images and temperature measurements in the liquid, the solid, and the gaseous phase. Data analysis provides the surface shape versus time and the corresponding apparent contact angle. Computational analysis provides information for the determination of the heat transfer coefficient in a compensated gravity environment where a flow is caused by the temperature difference between the hot wall and the cold liquid. The paper will deliver correlations for the effective contact angle and the heat transfer coefficient as a function of the relevant dimensionsless parameters as well as physical explanations for the observed behavior. The data will be used

  11. Characterization of Site for Installing Open Loop Ground Source Heat Pump System

    Science.gov (United States)

    Yun, S. W.; Park, Y.; Lee, J. Y.; Yi, M. J.; Cha, J. H.

    2014-12-01

    This study was conducted to understand hydrogeological properties of site where open loop ground source heat pump system will be installed and operated. Groundwater level and water temperature were hourly measured at the well developed for usage of open loop ground source heat pump system from 11 October 2013 to 8 January 2014. Groundwater was sampled in January and August 2013 and its chemical and isotopic compositions were analyzed. The bedrock of study area is the Jurassic granodiorite that mainly consists of quartz (27.9 to 46.8%), plagioclase (26.0 to 45.5%), and alkali feldspar (9.5 to 18.7%). The groundwater level ranged from 68.30 to 68.94 m (above mean sea level). Recharge rate was estimated using modified watertable fluctuation method and the recharge ratios was 9.1%. The water temperature ranged from 14.8 to 15.0oC. The vertical Increase rates of water temperature were 1.91 to 1.94/100 m. The water temperature showed the significant seasonal variation above 50 m depth, but had constant value below 50 m depth. Therefore, heat energy of the groundwater can be used securely in open loop ground source heat pump system. Electrical conductivity ranged from 120 to 320 µS/cm in dry season and from 133 to 310 µS/cm in wet season. The electrical conductivity gradually decreased with depth. In particular, electrical conductivity in approximately 30 m depth decreased dramatically (287 to 249 µS/cm) in wet season. The groundwater was Ca-HCO3 type. The concentrations of dissolved components did not show the vertically significant variations from 0 to 250 m depth. The δ18O and δD ranged from -9.5 to -9.4‰ and from -69 to -68‰. This work is supported by the New and Renewable Energy of the Korea Institute of Energy Technology Evaluation and Planning (KETEP) grant funded by the Korea government Ministry of Knowledge Economy (No.20123040110010).

  12. ELF/VLF wave generation from the beating of two HF ionospheric heating sources

    Science.gov (United States)

    Cohen, M. B.; Moore, R. C.; Golkowski, M.; Lehtinen, N. G.

    2012-12-01

    It is well established that Extremely Low Frequency (ELF, 0.3-3 kHz) and Very Low Frequency (VLF, 3-30 kHz) radio waves can be generated via modulated High Frequency (HF, 3-10 MHz) heating of the lower ionosphere (60-100 km). The ionospheric absorption of HF power modifies the conductivity of the lower ionosphere, which in the presence of natural currents such as the auroral electrojet, creates an `antenna in the sky.' We utilize a theoretical model of the HF to ELF/VLF conversion and the ELF/VLF propagation, and calculate the amplitudes of the generated ELF/VLF waves when two HF heating waves, separated by the ELF/VLF frequency, are transmitted from two adjacent locations. The resulting ELF/VLF radiation pattern exhibits a strong directional dependence (as much as 15 dB) that depends on the physical spacing of the two HF sources. This beat wave source can produce signals 10-20 dB stronger than those generated using amplitude modulation, particularly for frequencies greater than 5-10 kHz. We evaluate recent suggestions that beating two HF waves generates ELF/VLF waves in the F-region (>150 km), and conclude that those experimental results may have misinterpreted, and can be explained strictly by the much more well established D region mechanism.

  13. Mixed convection flow with non-uniform heat source/sink in a doubly stratified magnetonanofluid

    Science.gov (United States)

    Mehmood, K.; Hussain, S.; Sagheer, M.

    2016-06-01

    In this study, we explore the unsteady flow of viscous nanofluid driven by an inclined stretching sheet. The novelty of the present study is to account for the effect of a non-uniform heat source/sink in a thermally and solutally stratified magnetonanofluid. Governing system of nonlinear partial differential equations is converted into a system of nonlinear ordinary differential equations. Solution of the transformed system is obtained using RK4 method with shooting technique. It is observed that increase in the values of thermal and mass stratification parameter reduce the velocity profile and increase in the values of variable thermal conductivity parameter and non-uniform heat source/sink parameters enhance the temperature distribution. Moreover, skin friction coefficient, Nusselt number and Sherwood number are discussed. Obtained results are displayed both graphically and in tabular form to illustrate the effect of different parameters on the velocity, temperature and concentration profiles. Numerical results are compared with previous published results and found to be in good agreement for special cases of the emerging parameters.

  14. A comparative assessment of future heat and power sources for the UK domestic sector

    Energy Technology Data Exchange (ETDEWEB)

    Cockroft, Jeremy; Kelly, Nick [Energy Systems Research Unit, Department of Mechanical Engineering, 75 Montrose Street, University of Strathclyde, Glasgow G1 1XJ (United Kingdom)

    2006-09-15

    In 2003, the UK government announced its aspiration for a 60% reduction in CO{sub 2} emissions by 2050 relative to 1990 levels. To achieve this radical target, action is required across all sectors of the economy to reduce energy demand significantly and to increase the supply of energy from zero or low carbon sources. Focusing on the domestic sector, where energy consumption is currently rising, technologies such as fuel cells, Stirling and internal combustion engine micro-CHP and heat pumps are often cited as the means to reduce carbon emissions. However, there is much uncertainty as to the potential environmental benefits (if any) of the aforementioned technologies when set against a picture of changing energy supply and demand. The paper describes an analysis in which the performance of the four different technologies mentioned above was compared against a common datum of energy supply from condensing gas boilers and grid electricity for a number of scenarios. The aim of the analysis was to determine if significant CO{sub 2} savings could be made and to determine the minimum thermodynamic performance criteria that these technologies must attain if they are to yield any environmental benefits. The main finding of the work is that air source heat pumps yield significantly more CO{sub 2} savings than any of the other technologies examined. (author)

  15. Clinical applications of internal heat source analysis for breast cancer identification.

    Science.gov (United States)

    Han, F; Liang, C W; Shi, G L; Wang, L; Li, K Y

    2015-02-13

    Nondestructive preoperative breast imaging techniques are widely used for breast cancer testing and diagnosis. This study aimed to evaluate the feasibility and efficacy of quantitative diagnosis via the thermal analysis of abnormal metabolism. Nine hundred forty-eight women who underwent breast biopsy from 2009 to 2013 were investigated. Thermal analysis was used to calculate the internal heat source (i.e., tumor) thermal power for each participant. The applicability and effectiveness of our approach were estimated using the chi-square test, kappa statistics (k), and odds ratios (OR). Breast density and tumor size were considered during this estimation. A thermal power q = 0.2 w was determined as the optimal separation threshold between breast cancer and benign disease. Moreover, good agreement (k = 0.837) with the gold-standard assessment (breast biopsy) was confirmed in 93.2% of the patients (N = 884/948), and the sensitivity and specificity were 94.2 and 92.9%, respectively. The results also found no significant differences in methodological accuracy between the fatty and dense breasts (OR = 1.194, P = 0.524). Furthermore, after dividing the cohort into three groups according to tumor size (T1: 5 cm), the tumor size had no effect on the proposed method (ORs = 1, P = 0.724). Internal heat source analysis can feasibly and efficiently distinguish between breast cancer and benign disease.

  16. Flow characteristics of the raw sewage for the design of sewage-source heat pump systems.

    Science.gov (United States)

    Xu, Ying; Wu, Yuebin; Sun, Qiang

    2014-01-01

    The flow characteristics of raw sewage directly affect the technical and economic performance of sewage-source heat pump systems. The purpose of this research is to characterize the flow characteristics of sewage by experimental means. A sophisticated and flexible experimental apparatus was designed and constructed. Then the flow characteristics of the raw sewage were studied through laboratorial testing and theoretical analyses. Results indicated that raw sewage could be characterized as a power-law fluid with the rheological exponent n being 0.891 and the rheological coefficient k being 0.00175. In addition, the frictional loss factor formula in laminar flow for raw sewage was deduced by theoretical analysis of the power-law fluid. Furthermore, an explicit empirical formula for the frictional loss factor in turbulent flow was obtained through curve fitting of the experimental data. Finally, the equivalent viscosity of the raw sewage is defined in order to calculate the Reynolds number in turbulent flow regions; it was found that sewage had two to three times the viscosity of water at the same temperature. These results contributed to appropriate parameters of fluid properties when designing and operating sewage-source heat pump systems.

  17. Production of 238PuO2 heat sources for the Cassini mission

    Science.gov (United States)

    George, Timothy G.; Foltyn, Elizabeth M.

    1998-01-01

    NASA's Cassini mission to Saturn, scheduled to launch in October, 1997, is perhaps the most ambitious interplanetary explorer ever constructed. Electric power for the spacecraft's science instruments and on-board computers will be provided by three radioisotope thermoelectric generators (RTGs) powered by 216 238PuO2-fueled General-Purpose Heat Source (GPHS) capsules. In addition, critical equipment and instruments on the spacecraft and Huygens probe will be warmed by 128 Light-Weight Radioisotope Heater Units (LWRHUs). Fabrication and assembly of the GPHS capsules and LWRHU heat sources was performed at Los Alamos National Laboratory (LANL) between January 1994 and September 1996. During this production campaign, LANL pressed and sintered 315 GPHS fuel pellets and 181 LWRHU pellets. By October 1996, NMT-9 had delivered a total of 235 GPHS capsules to EG&G Mound Applied Technologies (EG&G MAT) in Miamisburg, Ohio. EG&G MAT conditioned the capsules for use, loaded the capsules into the Cassini RTGs, tested the RTGs, and coordinated transportation to Kennedy Space Center (KSC). LANL also fabricated and assembled a total of 180 LWRHUs. The LWRHUs required for the Cassini spacecraft were shipped to KSC in mid-1997.

  18. General-Purpose Heat Source Development: Safety Test Program. Postimpact evaluation, Design Iteration Test 3

    Energy Technology Data Exchange (ETDEWEB)

    Schonfeld, F.W.; George, T.G.

    1984-07-01

    The General-Purpose Heat Source(GPHS) provides power for space missions by transmitting the heat of /sup 238/PuO/sub 2/ decay to thermoelectric elements. Because of the inevitable return of certain aborted missions, the heat source must be designed and constructed to survive both re-entry and Earth impact. The Design Iteration Test (DIT) series is part of an ongoing test program. In the third test (DIT-3), a full GPHS module was impacted at 58 m/s and 930/sup 0/C. The module impacted the target at an angle of 30/sup 0/ to the pole of the large faces. The four capsules used in DIT-3 survived impact with minimal deformation; no internal cracks other than in the regions indicated by Savannah River Plant (SRP) preimpact nondestructive testing were observed in any of the capsules. The 30/sup 0/ impact orientation used in DIT-3 was considerably less severe than the flat-on impact utilized in DIT-1 and DIT-2. The four capsules used in DIT-1 survived, while two of the capsules used in DIT-2 breached; a small quantity (approx. = 50 ..mu..g) of /sup 238/PuO/sub 2/ was released from the capsules breached in the DIT-2 impact. All of the capsules used in DIT-1 and DIT-2 were severely deformed and contained large internal cracks. Postimpact analyses of the DIT-3 test components are described, with emphasis on weld structure and the behavior of defects identified by SRP nondestructive testing.

  19. Thermal stresses induced by a point heat source in a circular plate by quasi-static approach

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    The present paper deals with the determination of quasi-static thermal stresses due to an instantaneous point heat source of strength g_(pi) situated at certain circle along the radial direction of the circular plate and releasing its heat spontaneously at time t=τ.A circular plate is considered having arbitrary initial temperature and subjected to time dependent heat flux at the fixed circular boundary of r=b.The governing heat conduction equation is solved by using the integral transform method,and res...

  20. Numerical simulations of the impact of seasonal heat storage on source zone emission in a TCE contaminated aquifer

    Science.gov (United States)

    Popp, Steffi; Beyer, Christof; Dahmke, Andreas; Bauer, Sebastian

    2016-04-01

    In urban regions, with high population densities and heat demand, seasonal high temperature heat storage in the shallow subsurface represents an attractive and efficient option for a sustainable heat supply. In fact, the major fraction of energy consumed in German households is used for room heating and hot water production. Especially in urbanized areas, however, the installation of high temperature heat storage systems is currently restricted due to concerns on negative influences on groundwater quality caused e.g. by possible interactions between heat storages and subsurface contaminants, which are a common problem in the urban subsurface. Detailed studies on the overall impact of the operation of high temperature heat storages on groundwater quality are scarce. Therefore, this work investigates possible interactions between groundwater temperature changes induced by heat storage via borehole heat exchangers and subsurface contaminations by numerical scenario analysis. For the simulation of non-isothermal groundwater flow, and reactive transport processes the OpenGeoSys code is used. A 2D horizontal cross section of a shallow groundwater aquifer is assumed in the simulated scenario, consisting of a sandy sediment typical for Northern Germany. Within the aquifer a residual trichloroethene (TCE) contaminant source zone is present. Temperature changes are induced by a seasonal heat storage placed within the aquifer with scenarios of maximum temperatures of 20°C, 40°C and 60°C, respectively, during heat injection and minimum temperatures of 2°C during heat extraction. In the scenario analysis also the location of the heat storage relative to the TCE source zone and plume was modified. Simulations were performed in a homogeneous aquifer as well as in a set of heterogeneous aquifers with hydraulic conductivity as spatially correlated random fields. In both cases, results show that the temperature increase in the heat plume and the consequential reduction of water

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

    Science.gov (United States)

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

    2015-12-01

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

  2. Design Optimization and the Limits of Steady-State Heating Efficiency for Conventional Single-Speed Air-Source Heat Pumps

    Energy Technology Data Exchange (ETDEWEB)

    Rice, C.K.

    2001-06-06

    The ORNL Heat Pump Model and an optimizing program were used to explore the limits of steady-state heating efficiency for conventional air-source heat pumps. The method used allows for the simultaneous optimization of ten selected design variables, taking proper account of their interactions, while constraining other parameters to chosen limits or fixed values. Designs were optimized for a fixed heating capacity, but the results may be scaled to other capacities. Substantial performance improvement is predicted compared to today's state of the art heat pump. With increased component efficiencies that are expected in the near future and with modest increases in heat exchanger area, a 28% increase in heating efficiency is predicted; for long-term improvements with considerably larger heat exchangers, a 56% increase is possible. The improved efficiencies are accompanied by substantial reductions in the requirements for compressor and motor size. The predicted performance improvements are attributed not only to improved components and larger heat exchangers but also to the use of an optimizing design procedure. Deviations from the optimized design may be necessary to make use of available component sizes and to maintain good cooling-mode performance while improving the heating efficiency. Sensitivity plots (i.e., COP as a function of one or more design parameters) were developed to explore design flexibilities and to evaluate their consequences. The performance of the optimized designs was compared to that of modified ideal cycles to assess the factors that limit further improvement. It is hoped that the design methods developed will be useful to designers in the heat pump industry.

  3. X-RAY SOURCE HEIGHTS IN A SOLAR FLARE: THICK-TARGET VERSUS THERMAL CONDUCTION FRONT HEATING

    Energy Technology Data Exchange (ETDEWEB)

    Reep, J. W. [National Research Council Post-Doc Program, Naval Research Laboratory, Washington, DC 20375 (United States); Bradshaw, S. J. [Department of Physics and Astronomy, Rice University, Houston, TX 77005 (United States); Holman, G. D., E-mail: jeffrey.reep.ctr@nrl.navy.mil, E-mail: stephen.bradshaw@rice.edu, E-mail: gordon.d.holman@nasa.gov [Solar Physics Laboratory, Code 671, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)

    2016-02-10

    Observations of solar flares with RHESSI have shown X-ray sources traveling along flaring loops, from the corona down to the chromosphere and back up. The 2002 November 28 C1.1 flare, first observed with RHESSI by Sui et al. and quantitatively analyzed by O’Flannagain et al., very clearly shows this behavior. By employing numerical experiments, we use these observations of X-ray source height motions as a constraint to distinguish between heating due to a non-thermal electron beam and in situ energy deposition in the corona. We find that both heating scenarios can reproduce the observed light curves, but our results favor non-thermal heating. In situ heating is inconsistent with the observed X-ray source morphology and always gives a height dispersion with photon energy opposite to what is observed.

  4. X-ray Source Heights in a Solar Flare: Thick-target versus Thermal Conduction Front Heating

    CERN Document Server

    Reep, Jeffrey W; Holman, Gordon D

    2015-01-01

    Observations of solar flares with RHESSI have shown X-ray sources traveling along flaring loops, from the corona down to the chromosphere and back up. The 28 November 2002 C1.1 flare, first observed with RHESSI by Sui et al. 2006 and quantitatively analyzed by O'Flannagain et al. 2013, very clearly shows this behavior. By employing numerical experiments, we use these observations of X-ray source height motions as a constraint to distinguish between heating due to a non-thermal electron beam and in situ energy deposition in the corona. We find that both heating scenarios can reproduce the observed light curves, but our results favor non-thermal heating. In situ heating is inconsistent with the observed X-ray source morphology and always gives a height dispersion with photon energy opposite to what is observed.

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

    NARCIS (Netherlands)

    Fink, J.; van Leeuwen, Richard Pieter

    2016-01-01

    In this paper, we develop and investigate the optimal control of a group of 104 heat pumps and a central Combined Heat and Power unit (CHP). The heat pumps supply space heating and domestic hot water to households. Each house has a buffer for domestic hot water and a floor heating system for space h

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

    NARCIS (Netherlands)

    Fink, J.; van Leeuwen, Richard Pieter

    2016-01-01

    In this paper, we develop and investigate the optimal control of a group of 104 heat pumps and a central Combined Heat and Power unit (CHP). The heat pumps supply space heating and domestic hot water to households. Each house has a buffer for domestic hot water and a floor heating system for space

  7. Convective heat and mass transfer in three-dimensional mixed convection flow of viscoelastic fluid in presence of chemical reaction and heat source/sink

    Science.gov (United States)

    Bilal Ashraf, M.; Alsaedi, A.; Hayat, T.; Shehzad, S. A.

    2017-06-01

    Heat and mass transfer effects in the three-dimensional mixed convection flow of a viscoelastic fluid with internal heat source/sink and chemical reaction have been investigated in the present work. The flow generation is because of an exponentially stretching surface. Magnetic field normal to the direction of flow is considered. Convective conditions at the surface are also encountered. Appropriate similarity transformations are utilized to reduce the boundary layer partial differential equations into the ordinary differential equations. The homotopy analysis method is used to develop the solution expressions. Impacts of different controlling parameters such as ratio parameter, Hartman number, internal heat source/sink, chemical reaction, mixed convection, concentration buoyancy parameter and Biot numbers on the velocity, temperature and concentration profiles are analyzed. The local Nusselt and Sherwood numbers are sketched and examined.

  8. Experimental Optimization of Passive Cooling of a Heat Source Array Flush-Mounted on a Vertical Plate

    Directory of Open Access Journals (Sweden)

    Antoine Baudoin

    2016-11-01

    Full Text Available Heat sources, such as power electronics for offshore power, could be cooled passively—mainly by conduction and natural convection. The obvious advantage of this strategy is its high reliability. However, it must be implemented in an efficient manner (i.e., the area needs to be kept low to limit the construction costs. In this study, the placement of multiple heat sources mounted on a vertical plate was studied experimentally for optimization purposes. We chose a regular distribution, as this is likely to be the preferred choice in the construction process. We found that optimal spacing can be determined for a targeted source density by tuning the vertical and horizontal spacing between the heat sources. The optimal aspect ratio was estimated to be around two.

  9. Simulation and optimisation of a ground source heat pump with different ground heat exchanger configurations for a single-family residential house

    DEFF Research Database (Denmark)

    Pavlov, Georgi Krasimiroy; Olesen, Bjarne W.

    2012-01-01

    In the future there will be an increased demand for energy efficient cooling of residential buildings. Therefore it is essential to develop cooling concepts that are passive and/or using very little primary energy. A possible solution is a ground source heat pump combined with a low....... For the studied geographical location, passive cooling by bypassing the heat pump and using only the ground heat exchanger can provide acceptable room temperatures.......-temperature heating and high-temperature cooling system. The present work evaluates the performance in relation to thermal comfort and energy consumption of a GSHP with different GHE concepts. The different configurations are analyzed being part of the energy supply system of a low-energy residential house...

  10. Solid Waste from Swine Wastewater as a Fuel Source for Heat Production

    Directory of Open Access Journals (Sweden)

    Myung-Ho Park

    2012-11-01

    Full Text Available This study was to evaluate the feasibility of recycling the solids separated from swine wastewater treatment process as a fuel source for heat production and to provide a data set on the gas emissions and combustion properties. Also, in this study, the heavy metals in ash content were analyzed for its possible use as a fertilizer. Proximate analysis of the solid recovered from the swine wastewater after flocculation with organic polymer showed high calorific (5,330.50 kcal/kg and low moisture (15.38% content, indicating that the solid separated from swine wastewater can be used as an alternative fuel source. CO and NOx emissions were found to increase with increasing temperature. Combustion efficiency of the solids was found to be stable (95 to 98% with varied temperatures. Thermogravimetry (TG and differential thermal analysis (DTA showed five thermal effects (four exothermic and one endothermic, and these effects were distinguished in three stages, water evaporation, heterogeneous combustion of hydrocarbons and decomposition reaction. Based on the calorific value and combustion stability results, solid separated from swine manure can be used as an alternative source of fuel, however further research is still warranted regarding regulation of CO and NOx emissions. Furthermore, the heavy metal content in ash was below the legal limits required for its usage as fertilizer.

  11. Experimental study on heat supply of soil-seawater-source heat pump%土壤海水源热泵供暖实验研究

    Institute of Scientific and Technical Information of China (English)

    吴君华; 李海山; 牛林

    2014-01-01

    Sets up a field test platform of soil-seawater-source heat pump and performs heating experiment.The experimental results show that the higher the sand soil temperature is,the more the inlet water temperature of heat pump is,which results in larger heat exchanger capacity per unit length and higher COP of the heat pump system.Under the experimental conditions,the average value of heat exchanger capacity per unit length is 38.2 W/m,and the average value of COP is 1.8.The heat exchanger of soil-seawater-source heat pump system has little effect on the soil thermal environment due to stronger temperature restoration ability of shallow layer seabed soil.%搭建了土壤海水源现场实验台,进行了供暖实验。结果表明,沙层土壤温度越高,则机组进水温度也越高,单位管长换热量也就越大,热泵系统 COP 也就越大;实验工况下,单位管长换热量平均值为38.2 W/m,热泵系统COP 平均值为1.8;浅层海底沙层土壤温度恢复能力较强,盘管换热器对周围土壤热环境影响较小。

  12. Thermal hydraulic design and decay heat removal of a solid target for a spallation neutron source

    Energy Technology Data Exchange (ETDEWEB)

    Takenaka, N. [Department of Mechanical Engineering, Kobe University, Kobe (Japan)]. E-mail: takenaka@mech.kobe-u.ac.jp; Nio, D. [Hokkaido University, Sapporo (Japan); Kiyanagi, Y. [Hokkaido University, Sapporo (Japan); Mishima, K. [Kyoto University Research Reactor Institute, Kumatori (Japan); Kawai, M. [High Energy Accelerator Research Institute, Tsukuba (Japan); Furusaka, M. [High Energy Accelerator Research Institute, Tsukuba (Japan)

    2005-08-01

    Thermal hydraulic design and thermal stress calculations were conducted for a water-cooled solid target irradiated by a MW-class proton beam for a spallation neutron source. Plate type and rod bundle type targets were examined. The thickness of the plate and the diameter of the rod were determined based on the maximum and the wall surface temperature. The thermal stress distributions were calculated by a finite element method (FEM). The neutronics performance of the target is roughly proportional to its average density. The averaged densities of the designed targets were calculated for tungsten plates, tantalum-clad tungsten plates, tungsten rods sheathed by tantalum and Zircaloy and they were compared with mercury density. It was shown that the averaged density was highest for the tungsten plates and was high for the tantalum cladding tungsten plates, the tungsten rods sheathed by tantalum and Zircaloy in order. They were higher than or equal to that of mercury for the 1-2 MW proton beams. Tungsten target without the cladding or the sheath is not practical due to corrosion by water under irradiation condition. Therefore, the tantalum cladding tungsten plate already made successfully by HIP and the sheathed tungsten rod are the candidate of high performance solid targets. The decay heat of each target was calculated. It was low enough low compared to that of ISIS for the target without tantalum but was about four times as high as that of ISIS when the thickness of the tantalum cladding was 0.5 mm. Heat removal methods of the decay heat with tantalum were examined. It was shown that a special cooling system was required for the target exchange when tantalum was used for the target. It was concluded that the tungsten rod target sheathed with stainless steel or Zircaloy was the most reliable from the safety considerations and had similar neutronics performance to that of mercury.

  13. Thermal hydraulic design and decay heat removal of a solid target for a spallation neutron source

    Science.gov (United States)

    Takenaka, N.; Nio, D.; Kiyanagi, Y.; Mishima, K.; Kawai, M.; Furusaka, M.

    2005-08-01

    Thermal hydraulic design and thermal stress calculations were conducted for a water-cooled solid target irradiated by a MW-class proton beam for a spallation neutron source. Plate type and rod bundle type targets were examined. The thickness of the plate and the diameter of the rod were determined based on the maximum and the wall surface temperature. The thermal stress distributions were calculated by a finite element method (FEM). The neutronics performance of the target is roughly proportional to its average density. The averaged densities of the designed targets were calculated for tungsten plates, tantalum clad tungsten plates, tungsten rods sheathed by tantalum and Zircaloy and they were compared with mercury density. It was shown that the averaged density was highest for the tungsten plates and was high for the tantalum cladding tungsten plates, the tungsten rods sheathed by tantalum and Zircaloy in order. They were higher than or equal to that of mercury for the 1 2 MW proton beams. Tungsten target without the cladding or the sheath is not practical due to corrosion by water under irradiation condition. Therefore, the tantalum cladding tungsten plate already made successfully by HIP and the sheathed tungsten rod are the candidate of high performance solid targets. The decay heat of each target was calculated. It was low enough low compared to that of ISIS for the target without tantalum but was about four times as high as that of ISIS when the thickness of the tantalum cladding was 0.5 mm. Heat removal methods of the decay heat with tantalum were examined. It was shown that a special cooling system was required for the target exchange when tantalum was used for the target. It was concluded that the tungsten rod target sheathed with stainless steel or Zircaloy was the most reliable from the safety considerations and had similar neutronics performance to that of mercury.

  14. Moving heat source response in micropolar half-space with two-temperature theory

    Science.gov (United States)

    Shaw, Soumen; Mukhopadhyay, Basudeb

    2013-03-01

    The present paper deals with the moving heat source response in a homogeneous, isotropic, micropolar semi-infinite medium in the presence of a finite rotation about its axis. In this context, two-temperature generalized thermoelasticity theory has been considered. In order to obtain the physical aspects of displacement, microrotation, stress distribution and temperature changes, a complex quartic equation has been solved by employing Descartes' algorithm with the help of an irreducible Cardan's method. To illustrate the analytical developments, the numerical solutions have been carried out for aluminum-epoxy composite, and the variations in displacement, microrotation, stress distribution and temperature changes have been shown graphically. This work may find applications in geophysics.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-01-01

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

  16. Comparative study of beam losses and heat loads reduction methods in MITICA beam source

    Energy Technology Data Exchange (ETDEWEB)

    Sartori, E., E-mail: emanuele.sartori@igi.cnr.it; Agostinetti, P.; Dal Bello, S.; Marcuzzi, D.; Serianni, G.; Veltri, P. [Consorzio RFX, Euratom-ENEA association, C.so Stati Uniti 4, 35127 Padova (Italy); Sonato, P. [Consorzio RFX, Euratom-ENEA association, C.so Stati Uniti 4, 35127 Padova (Italy); Dipartimento di Ingegneria Elettrica, Padova University, Via Gradenigo 6/a, 35131 Padova (Italy)

    2014-02-15

    In negative ion electrostatic accelerators a considerable fraction of extracted ions is lost by collision processes causing efficiency loss and heat deposition over the components. Stripping is proportional to the local density of gas, which is steadily injected in the plasma source; its pumping from the extraction and acceleration stages is a key functionality for the prototype of the ITER Neutral Beam Injector, and it can be simulated with the 3D code AVOCADO. Different geometric solutions were tested aiming at the reduction of the gas density. The parameter space considered is limited by constraints given by optics, aiming, voltage holding, beam uniformity, and mechanical feasibility. The guidelines of the optimization process are presented together with the proposed solutions and the results of numerical simulations.

  17. Comparative study of beam losses and heat loads reduction methods in MITICA beam source

    Science.gov (United States)

    Sartori, E.; Agostinetti, P.; Dal Bello, S.; Marcuzzi, D.; Serianni, G.; Sonato, P.; Veltri, P.

    2014-02-01

    In negative ion electrostatic accelerators a considerable fraction of extracted ions is lost by collision processes causing efficiency loss and heat deposition over the components. Stripping is proportional to the local density of gas, which is steadily injected in the plasma source; its pumping from the extraction and acceleration stages is a key functionality for the prototype of the ITER Neutral Beam Injector, and it can be simulated with the 3D code AVOCADO. Different geometric solutions were tested aiming at the reduction of the gas density. The parameter space considered is limited by constraints given by optics, aiming, voltage holding, beam uniformity, and mechanical feasibility. The guidelines of the optimization process are presented together with the proposed solutions and the results of numerical simulations.

  18. Attenuation of Scintillation of Discrete Cosmic Sources during Nonresonant HF Heating of the Upper Ionosphere

    Science.gov (United States)

    Bezrodny, V. G.; Watkins, B.; Charkina, O. V.; Yampolski, Y. M.

    2014-03-01

    The aim of the work is to experimentally investigate the response of scintillation spectra and indices of discrete cosmic sources (DCS) to modification of the ionospheric F-region by powerful electromagnetic fields with frequencies exceeding the Langmuir and upper hybrid ones. The results of a special experiment on the scintillations of radiation from DCS Cygnus A observed with using the 64-beam imaging riometer located near the Gakona village (Alaska, USA) are here presented. The ionosphere was artificially disturbed by powerful HAARP heater. Under the studied conditions of nonresonant heating of the ionospheric plasma, an earlier unknown effect of reducing the level of DCS scintillation was discovered. The theoretical interpretation has been given for the discovered effect, which using allowed the proposed technique of solving the inverse problem (recovery deviations of average electron density and temperature in the modified region from their unperturbed values).

  19. Aerodynamic levitation and laser heating: Applications at synchrotron and neutron sources

    Energy Technology Data Exchange (ETDEWEB)

    Hennet, L.; Pozdnyakova, I.; Drewitt, J.W.E.; Leydier, M.; Brassamin, S.; Zanghi, D.; Magazu, S.; Price, D.L. [CEMHTI and University of Orleans, 45071 Orleans Cedex 02 (France); Cristiglio, V.; Kozaily, J.; Fischer, H.E.; Cuello, G.J.; Koza, M. [ILL, BP. 156, 38042 Grenoble Cedex 09 (France); Bytchkov, A. [ESRF, BP. 220, 38043 Grenoble Cedex 09 (France); Thiaudiere, D. [Synchrotron SOLEIL, BP. 48, 91192 Gif-sur-Yvette Cedex (France); Gruner, S. [Institute of Physics, Chemnitz UT, 09107 Chemnitz (Germany); Greaves, G.N. [IMAPS, University of Wales, Aberystwyth, SY23 3BZ (United Kingdom)

    2011-05-15

    Aerodynamic levitation is an effective way to suspend samples which can be heated with CO{sub 2} lasers. The advantages of this container-less technique are the simplicity and compactness of the device, making it possible to integrate it easily in different kinds of experiments. In addition, all types of materials can be used, including metals and oxides. The integration of aerodynamic levitation at synchrotron and neutron sources provides powerful tools to study the structure and dynamics of molten materials. We present here an overview of the existing techniques (electromagnetic levitation, electrostatic levitation, single-axis acoustic levitation, and aerodynamic levitation) and of the developments made at the CEMHTI in Orleans, as well as a few examples of experimental results already obtained. (authors)

  20. Literature Review: Weldability of Iridium DOP-26 Alloy for General Purpose Heat Source

    Energy Technology Data Exchange (ETDEWEB)

    Burgardt, Paul [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Pierce, Stanley W. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-10-19

    The basic purpose of this paper is to provide a literature review relative to fabrication of the General Purpose Heat Source (GPHS) that is used to provide electrical power for deep space missions of NASA. The particular fabrication operation to be addressed here is arc welding of the GPHS encapsulation. A considerable effort was made to optimize the fabrication of the fuel pellets and of other elements of the encapsulation; that work will not be directly addressed in this paper. This report consists of three basic sections: 1) a brief description of the GPHS will be provided as background information for the reader; 2) mechanical properties and the optimization thereof as relevant to welding will be discussed; 3) a review of the arc welding process development and optimization will be presented. Since the welding equipment must be upgraded for future production, some discussion of the historical establishment of relevant welding variables and possible changes thereto will also be discussed.

  1. Errors in Thermographic Camera Measurement Caused by Known Heat Sources and Depth Based Correction

    Directory of Open Access Journals (Sweden)

    Mark Christian E. Manuel

    2016-03-01

    Full Text Available Thermal imaging has shown to be a better tool for the quantitative measurement of temperature than single spot infrared thermometers. However, thermographic cameras can encounter errors in acquiring accurate temperature measurements in the presence of other environmental heat sources. Some of these errors arise due to the inability of the thermal camera to detect objects and features in the infrared domain. In this paper, the thermal image is registered as a stereo image from a Kinect system prior to depth-based correction. Experiments demonstrating the error are presented together with the determination of the measurement errors under prior knowledge of the thermographed scene. The proposed correction scheme improves the accuracy of the thermal image through augmentation using the Kinect system.

  2. Regulatory framework and examples of ground-source heating/cooling technology in the Winnipeg area

    Energy Technology Data Exchange (ETDEWEB)

    Matthews, R. [Manitoba Conservation, Winnipeg, MB (Canada)

    2003-07-01

    Winnipeg, Manitoba lies over a highly transmissive Carbonate Aquifer of Ordovician age, which provides a suitable environment for groundwater supply and return wells. Many licensed ground-source heating cooling (GSHC) systems have been installed in and around the Winnipeg urban area over the last several decades. A water rights licence, issued by the Provincial Department of Conservation, is required for all groundwater supply and return wells. This licence comes with certain rights and responsibilities. This paper describes the regulatory framework which governs the licensing process. The author emphasized that the future use and success of the technology depends, in large part, on the development of a critical mass of experienced contractors, hydrogeologists and consulting engineers. 2 refs.

  3. On the Response of an OST to a Point-like Heat Source

    CERN Document Server

    Quadt, A; Uhrmacher, M; Weingarten, J; Willenberg, B; Vennekate, H

    2011-01-01

    A new technique of superconducting cavity diagnostics has been introduced by D. Hartrill at Cornell University, Ithaca, USA. Oscillating Superleak Transducers (OST) detect the heat transferred from a cavity's quench point via "Second Sound" through the superfluid He bath, needed to cool the superconducting cavity. The observed response of an OST is a complex, but reproducible pattern of oscillations. A small helium evaporation cryostat was built which allows the investigation of the response of an OST in greater detail. The distance between a point-like electrical heater and the OST can be varied. The OST can be mounted either parallel or perpendicular to the plate, housing the heat source. If the artificial quench-point releases an amount of energy compatible to a real quench spot on a cavity's surface, the OST signal starts with a negative pulse, which is usually strong enough to allow automatic detection. Furthermore, the reflection of the Second Sound on the wall is observed. A reflection coefficient R = ...

  4. High-frequency torsional Alfvén waves as an energy source for coronal heating

    Science.gov (United States)

    Srivastava, Abhishek Kumar; Shetye, Juie; Murawski, Krzysztof; Doyle, John Gerard; Stangalini, Marco; Scullion, Eamon; Ray, Tom; Wójcik, Dariusz Patryk; Dwivedi, Bhola N.

    2017-03-01

    The existence of the Sun’s hot atmosphere and the solar wind acceleration continues to be an outstanding problem in solar-astrophysics. Although magnetohydrodynamic (MHD) modes and dissipation of magnetic energy contribute to heating and the mass cycle of the solar atmosphere, yet direct evidence of such processes often generates debate. Ground-based 1-m Swedish Solar Telescope (SST)/CRISP, Hα 6562.8 Å observations reveal, for the first time, the ubiquitous presence of high frequency (~12–42 mHz) torsional motions in thin spicular-type structures in the chromosphere. We detect numerous oscillating flux tubes on 10 June 2014 between 07:17 UT to 08:08 UT in a quiet-Sun field-of-view of 60” × 60” (1” = 725 km). Stringent numerical model shows that these observations resemble torsional Alfvén waves associated with high frequency drivers which contain a huge amount of energy (~105 W m‑2) in the chromosphere. Even after partial reflection from the transition region, a significant amount of energy (~103 W m‑2) is transferred onto the overlying corona. We find that oscillating tubes serve as substantial sources of Alfvén wave generation that provide sufficient Poynting flux not only to heat the corona but also to originate the supersonic solar wind.

  5. Geothermal(Ground-Source)Heat Pumps: Market Status, Barriers to Adoption, and Actions to Overcome Barriers

    Energy Technology Data Exchange (ETDEWEB)

    Hughes, Patrick [ORNL

    2008-12-01

    More effective stewardship of our resources contributes to the security, environmental sustainability, and economic well-being of the nation. Buildings present one of the best opportunities to economically reduce energy consumption and limit greenhouse gas emissions. Geothermal heat pumps (GHPs), sometimes called ground-source heat pumps, have been proven capable of producing large reductions in energy use and peak demand in buildings. However, GHPs have received little attention at the policy level as an important component of a national strategy. Have policymakers mistakenly overlooked GHPs, or are GHPs simply unable to make a major contribution to the national goals for various reasons? This brief study was undertaken at DOE's request to address this conundrum. The scope of the study includes determining the status of global GHP markets and the status of the GHP industry and technology in the United States, assembling previous estimates of GHP energy savings potential, identifying key barriers to application of GHPs, and identifying actions that could accelerate market adoption of GHPs. The findings are documented in this report along with conclusions and recommendations.

  6. Promoting renewable energy sources for heating and cooling in EU-27 countries

    Energy Technology Data Exchange (ETDEWEB)

    Cansino, Jose M., E-mail: jmcansino@us.es [Department of Economic Analysis and Political Economy, Seville University, Avda. Ramon y Cajal, no. 1, 41018 Seville (Spain); Pablo-Romero, Maria del P. [Department of Economic Analysis and Political Economy, Seville University, Avda. Ramon y Cajal, no. 1, 41018 Seville (Spain); Roman, Rocio, E-mail: rroman@us.es [Department of Economic Analysis and Political Economy, Seville University, Avda. Ramon y Cajal, no. 1, 41018 Seville (Spain); Yniguez, Rocio [Department of Economic Analysis and Political Economy, Seville University, Avda. Ramon y Cajal, no. 1, 41018 Seville (Spain)

    2011-06-15

    In addition to public policies aimed at improving the energy efficiency of buildings, EU authorities have also promoted the use of Renewable Energy Sources for heating and cooling uses (RES H and C). This paper analyses the main policy measures implemented in EU-27 countries up to 2009: i.e. subsidies, tax incentives, financial support and feed-in tariffs. Twenty-three Member States (MSs) have developed some of these policy measures. The most widespread measure is the subsidy (22 MSs have implemented these) because from a political point of view, subsidies provide a straightforward approach to promote the use of RES H and C. Secondly, tax incentives have been used for reducing investment costs and making renewable energy profitable. Thirdly, financial incentives and feed-in tariffs have been used sparingly. While financial incentives might be used more extensively for promoting RES H and C if they are accompanied by other policy measures, feed-in tariffs are not likely to be implemented significantly in the future because this measure is not designed for household heat producers. - Highlights: > Main EU policies to reduce energy consumption are focused on buildings' efficiency. > Alternative incentives to promote the use of RES H and C in EU-27 are now studied. > Subsidies are the most widespread measure. > Tax incentives are used for reducing investment costs and making RES profitable. > Financial incentives and feed-in tariffs have been used sparingly.

  7. High current multicharged metal ion source using high power gyrotron heating of vacuum arc plasma.

    Science.gov (United States)

    Vodopyanov, A V; Golubev, S V; Khizhnyak, V I; Mansfeld, D A; Nikolaev, A G; Oks, E M; Savkin, K P; Vizir, A V; Yushkov, G Yu

    2008-02-01

    A high current, multi charged, metal ion source using electron heating of vacuum arc plasma by high power gyrotron radiation has been developed. The plasma is confined in a simple mirror trap with peak magnetic field in the plug up to 2.5 T, mirror ratio of 3-5, and length variable from 15 to 20 cm. Plasma formed by a cathodic vacuum arc is injected into the trap either (i) axially using a compact vacuum arc plasma gun located on axis outside the mirror trap region or (ii) radially using four plasma guns surrounding the trap at midplane. Microwave heating of the mirror-confined, vacuum arc plasma is accomplished by gyrotron microwave radiation of frequency 75 GHz, power up to 200 kW, and pulse duration up to 150 micros, leading to additional stripping of metal ions by electron impact. Pulsed beams of platinum ions with charge state up to 10+, a mean charge state over 6+, and total (all charge states) beam current of a few hundred milliamperes have been formed.

  8. High-frequency torsional Alfvén waves as an energy source for coronal heating

    Science.gov (United States)

    Srivastava, Abhishek Kumar; Shetye, Juie; Murawski, Krzysztof; Doyle, John Gerard; Stangalini, Marco; Scullion, Eamon; Ray, Tom; Wójcik, Dariusz Patryk; Dwivedi, Bhola N.

    2017-01-01

    The existence of the Sun’s hot atmosphere and the solar wind acceleration continues to be an outstanding problem in solar-astrophysics. Although magnetohydrodynamic (MHD) modes and dissipation of magnetic energy contribute to heating and the mass cycle of the solar atmosphere, yet direct evidence of such processes often generates debate. Ground-based 1-m Swedish Solar Telescope (SST)/CRISP, Hα 6562.8 Å observations reveal, for the first time, the ubiquitous presence of high frequency (~12–42 mHz) torsional motions in thin spicular-type structures in the chromosphere. We detect numerous oscillating flux tubes on 10 June 2014 between 07:17 UT to 08:08 UT in a quiet-Sun field-of-view of 60” × 60” (1” = 725 km). Stringent numerical model shows that these observations resemble torsional Alfvén waves associated with high frequency drivers which contain a huge amount of energy (~105 W m−2) in the chromosphere. Even after partial reflection from the transition region, a significant amount of energy (~103 W m−2) is transferred onto the overlying corona. We find that oscillating tubes serve as substantial sources of Alfvén wave generation that provide sufficient Poynting flux not only to heat the corona but also to originate the supersonic solar wind. PMID:28256538

  9. An Experimental Facility to Validate Ground Source Heat Pump Optimisation Models for the Australian Climate

    Directory of Open Access Journals (Sweden)

    Yuanshen Lu

    2017-01-01

    Full Text Available Ground source heat pumps (GSHPs are one of the most widespread forms of geothermal energy technology. They utilise the near-constant temperature of the ground below the frost line to achieve energy-efficiencies two or three times that of conventional air-conditioners, consequently allowing a significant offset in electricity demand for space heating and cooling. Relatively mature GSHP markets are established in Europe and North America. GSHP implementation in Australia, however, is limited, due to high capital price, uncertainties regarding optimum designs for the Australian climate, and limited consumer confidence in the technology. Existing GSHP design standards developed in the Northern Hemisphere are likely to lead to suboptimal performance in Australia where demand might be much more cooling-dominated. There is an urgent need to develop Australia’s own GSHP system optimisation principles on top of the industry standards to provide confidence to bring the GSHP market out of its infancy. To assist in this, the Queensland Geothermal Energy Centre of Excellence (QGECE has commissioned a fully instrumented GSHP experimental facility in Gatton, Australia, as a publically-accessible demonstration of the technology and a platform for systematic studies of GSHPs, including optimisation of design and operations. This paper presents a brief review on current GSHP use in Australia, the technical details of the Gatton GSHP facility, and an analysis on the observed cooling performance of this facility to date.

  10. Studying on the increasing temperature in IT-SOFC: Effect of heat sources

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The dimensions and the materials type limit the performance of fuel cell. The increase of the temperature in electrodes and electrolyte of the cell, is due to the over potential of activation (transfer of load), the over potential Ohmic (resistance of polarization), the over potential of reaction (heat released by the chemical reaction) and the over potential of diffusion. In this paper,we studied the thermo-electrical performance of an intermediate temperature solid oxide fuel cell (IT-SOFC) with electrode supported. The aim of this work is to study this increasing temperature of a single cell of an IT-SOFC under the influence of the following parameters: heat sources, functioning temperature and voltages of the cell, geometric configuration and materials type.The equation of energy in one dimension is numerically resolved by using the method of finite volumes. A computing program (FORTRAN) is developed locally for this purpose in order to obtain fields of temperature in every element of the cell.

  11. Increase of COP for heat transformer in water purification systems. Part II - Without increasing heat source temperature

    Energy Technology Data Exchange (ETDEWEB)

    Romero, R.J. [Centro de Investigacion en Ingenieria y Ciencias Aplicadas, Universidad Autonoma del Estado de Morelos, Av. Universidad 1001, Col. Chamilpa, C.P. 62209 Cuernavaca, Morelos (Mexico)]. E-mail: rosenberg@uaem.mx; Siqueiros, J. [Centro de Investigacion en Ingenieria y Ciencias Aplicadas, Universidad Autonoma del Estado de Morelos, Av. Universidad 1001, Col. Chamilpa, C.P. 62209 Cuernavaca, Morelos (Mexico); Huicochea, A. [Posgrado en Ingenieria y Ciencias Aplicadas, Universidad Autonoma del Estado de Morelos, Av. Universidad 1001, Col. Chamilpa, C.P. 62209 Cuernavaca, Morelos (Mexico)

    2007-04-15

    The integration of a water purification system allows a heat transformer to increase the actual coefficient of performance, by the reduction of the amount of heat supplied by unit of heat. A new defined COP called COP{sub WP} is proposed for the present system, which considers the fraction of heat recycled. Simulation with proven software compares the performance of the modeling of an absorption heat transformer for water purification (AHTWP) operating with water/lithium bromide, as working fluid-absorbent pair. Plots of enthalpy-based coefficients of performance (COP{sub ET}) and water purification coefficient of performance (COP{sub WP}) are shown against absorber temperature for several thermodynamic operating conditions. The results showed that the proposed (AHTWP) system is capable of increasing the original value of COP{sub ET} up to 1.6 times its original value by recycling energy from a water purification system. The proposed COP{sub WP} allows increments for COP values from any experimental data for water purification or for any other distillation system integrated to a heat transformer, regardless of actual COP{sub A} value or working fluid-absorbent pair.

  12. Increase of COP for heat transformer in water purification systems. Pt. 2 - Without increasing heat source temperature

    Energy Technology Data Exchange (ETDEWEB)

    Romero, R.J.; Siqueiros, J. [Centro de Investigacion en Ingenieria y Ciencias Aplicadas, Universidad Autonoma del Estado de Morelos, Av. Universidad 1001, Col. Chamilpa, C.P. 62209 Cuernavaca, Morelos (Mexico); Huicochea, A. [Posgrado en Ingenieria y Ciencias Aplicadas, Universidad Autonoma del Estado de Morelos, Av. Universidad 1001, Col. Chamilpa, C.P. 62209 Cuernavaca, Morelos (Mexico)

    2007-04-15

    The integration of a water purification system allows a heat transformer to increase the actual coefficient of performance, by the reduction of the amount of heat supplied by unit of heat. A new defined COP called COP{sub WP} is proposed for the present system, which considers the fraction of heat recycled. Simulation with proven software compares the performance of the modeling of an absorption heat transformer for water purification (AHTWP) operating with water/lithium bromide, as working fluid-absorbent pair. Plots of enthalpy-based coefficients of performance (COP{sub ET}) and water purification coefficient of performance (COP{sub WP}) are shown against absorber temperature for several thermodynamic operating conditions. The results showed that the proposed (AHTWP) system is capable of increasing the original value of COP{sub ET} up to 1.6 times its original value by recycling energy from a water purification system. The proposed COP{sub WP} allows increments for COP values from any experimental data for water purification or for any other distillation system integrated to a heat transformer, regardless of actual COP{sub A} value or working fluid-absorbent pair. (author)

  13. Inverse conjugate mixed convection in a vertical substrate with protruding heat sources: a combined experimental and numerical study

    Science.gov (United States)

    Ahamad, Shaik Imran; Balaji, C.

    2016-06-01

    This paper reports the results of a combined numerical and experimental study to estimate the heat inputs of three protruding heat sources of the same size placed on a vertically placed PCB board of height 150 mm, depth 250 mm, and thickness 5 mm. First, limited measurements of temperatures were recorded at eight locations along the height of the back of the PCB board for different (and known) values of heat inputs of the protruding heat sources and different velocities. These were followed by three-dimensional calculations of fluid flow and conjugate heat transfer for various heat transfer coefficients on the backside of the PCB board. The difference between the CFD predicted and experimentally measured temperature distributions on the back of the PCB board was minimized using least squares and the best value of heat transfer coefficient was obtained. Using this `data assimilated' CFD model, detailed CFD simulations were done for various values of heat input values and Reynolds numbers (each of these can be different from one another) of the flow. The temperatures at the same eight locations at the back of the PCB board were noted. An artificial neural network was then developed with ten inputs (eight temperatures together with the input velocity and the ambient temperature) to estimate the three outputs (three heat inputs) after carrying out extensive studies on the architecture of the network. This inverse solution was then tested with experiments for validating the ANN approach to solve the inverse conjugate heat transfer problem. Finally, with the ANN estimated heat inputs, CFD simulations were again run to compare the temperature distribution at the back of the PCB board with measurements.

  14. Irreversible three-heat-source refrigerator with heat transfer law of Q{alpha}{delta}(T{sup -1}) and its performance optimization based on ECOP criterion

    Energy Technology Data Exchange (ETDEWEB)

    Ngouateu Wouagfack, Paiguy Armand [University of Dschang, L2MSP, Department of Physics, PO Box 67, Dschang (Cameroon); Tchinda, Rene [University of Dschang, LISIE, University Institute of Technology Fotso Victor, PO Box 134, Bandjoun (Cameroon)

    2011-11-15

    The new thermo-ecological optimization of an absorption system for cooling applications operating between three temperature levels with the linear phenomenological heat transfer law of Q{alpha}{delta}(T{sup -} {sup 1}) has been performed by taking account the losses of heat resistance, internal irreversibility and leakage. The considered objective function is the ecological coefficient of performance (ECOP) and is defined as the cooling load per unit loss rate of availability. The comparative analysis with the ecological optimization criterion (E) defined in the literature and also with the cooling load optimization criterion (R) has been carried out to prove the utility of the new thermo-ecological optimization criterion (ECOP) for three-heat-source refrigerators with linear phenomenological heat transfer law. The results show that the three-heat-source refrigeration cycle working at maximum ECOP conditions has a significant advantage in terms of entropy production rate and coefficient of performance over the maximum E and maximum R conditions. The obtained results may provide a general theoretical tool for the thermo-ecological design of absorption refrigerator. (orig.)

  15. Effect of heat source on MHD free convection flow past an oscillating porous plate in the slip flow regime

    Directory of Open Access Journals (Sweden)

    S. S. Das, L. K. Mishra, P. K. Mishra

    2011-09-01

    Full Text Available This paper investigates the effect of heat source on free convective flow of a viscous incompressible electrically conducting fluid through a porous medium bounded by an oscillating porous plate in the slip flow regime in presence of a transverse magnetic field. The governing equations of the flow field are solved analytically and the expressions for velocity, temperature, skin friction t and the heat flux in terms of Nusselts number Nu are obtained. The effects of the important flow parameters such as magnetic parameter M, permeability parameter Kp, Grashof number for heat transfer Gr, heat source parameter S and rarefaction parameter R on the velocity of the flow field are analyzed quantitatively with the help of figures.

  16. Experimental Study on the Thermal Stratification in a Pool Boiling with a Horizontal Heat Source

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Seok; Ryu, Sung Uk; Euh, Dong-Jin; Song, Chul-Hwa [KAERI, Daejeon (Korea, Republic of)

    2015-05-15

    temperature rise and the dissipation of the thermal stratification at the stagnant region in a pool boiling with a horizontal heat source installed asymmetrically. The thermal stratification and stagnant region began to disappear when the pool temperature reached to over 90 .deg. C. The present experimental results can help characterize the performance of boiling models on heated surfaces and provide benchmark data to validate the calculation performance of a thermal hydraulic system analysis code.

  17. A proposal for a novel H ion source based on electron cyclotron resonance heating and surface ionization

    Energy Technology Data Exchange (ETDEWEB)

    Tarvainen, Ollie A [Los Alamos National Laboratory; Kurennoy, Sergey [Los Alamos National Laboratory

    2008-01-01

    A design for a novel H{sup -} ion source based on electron cyclotron resonance plasma heating and surface ionization is presented. The plasma chamber of the source is an rf-cavity designed for TE{sub 111} eigenmode at 2.45 GHz. The desired mode is excited with a loop antenna. The ionization process takes place on a cesiated surface of a biased converter electrode. The H{sup -} ion beam is further 'self-extracted' through the plasma region. The magnetic field of the source is optimized for plasma generation by electron cyclotron resonance heating, and beam extraction. The design features of the source are discussed in detail and the attainable H{sup -} ion current, beam emittance and duty factor of the novel source are estimated.

  18. A Proposal for a Novel H- Ion Source Based on Electron Cyclotron Resonance Plasma Heating and Surface Ionization

    Science.gov (United States)

    Tarvainen, O.; Kurennoy, S.

    2009-03-01

    A design for a novel H- ion source based on electron cyclotron resonance plasma heating and surface ionization is presented. The plasma chamber of the source is an rf-cavity designed for TE111 eigenmode at 2.45 GHz. The desired mode is excited with a loop antenna. The ionization process takes place on a cesiated surface of a biased converter electrode. The H- ion beam is further "self-extracted" through the plasma region. The magnetic field of the source is optimized for plasma generation by electron cyclotron resonance heating, and beam extraction. The design features of the source are discussed in detail and the attainable H- ion current, beam emittance and duty factor of the novel source are estimated.

  19. Recovery Act - Geothermal Technologies Program: Ground Source Heat Pumps Final Scientific/Technical Report

    Energy Technology Data Exchange (ETDEWEB)

    Nick Rosenberry, Harris Companies

    2012-05-04

    A large centralized geothermal heat pump system was installed to provide ice making, space cooling, space heating, process water heating, and domestic hot water heating for an ice arena in Eagan Minnesota. This paper provides information related to the design and construction of the project. Additionally, operating conditions for 12 months after start-up are provided.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-02-15

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

  1. Numerical simulation of seepage flow field in groundwater source heat pump system and its influence on temperature field

    Institute of Scientific and Technical Information of China (English)

    Jihua HU; Yanjun ZHANG; Danyan DU; Gang WU; Ziwang YU; Chen WANG; Fuquan NI

    2008-01-01

    Energy utilization in the aquifers is a new technology closely related to development of heat pump technique. It is significant for the flow distribution to be predicted in the aquifer surrounding the Groundwater Source Heat Pump System (GSHPS). The authors presented a new concept of "flow transfixion" by analyzing general features of aquifers, and then discussed interaction of the flow transfixion with the heat transfixion, which has practical significance to projects. A numerical model of groundwater flow was established based on the basic tenets of water-heat transferring in the aquifer. On this basis the flow field and the temperature field of GSHPS for a site in Shenyang City were numerically simulated. The basis of the flow transfixion was obtained; it was discussed for the influence of the flow transfixion on the heat transfixion. To a certain extent, the study offers some reference for the projects' design of GSHP in the studied area.

  2. Temperature field due to time-dependent heat sources in a large rectangular grid - Derivation of analytical solution

    Energy Technology Data Exchange (ETDEWEB)

    Claesson, J.; Probert, T. [Lund Univ. (Sweden). Dept. of Building Physics and Mathematical Physics

    1996-01-01

    The temperature field in rock due to a large rectangular grid of heat releasing canisters containing nuclear waste is studied. The solution is by superposition divided into different parts. There is a global temperature field due to the large rectangular canister area, while a local field accounts for the remaining heat source problem. The global field is reduced to a single integral. The local field is also solved analytically using solutions for a finite line heat source and for an infinite grid of point sources. The local solution is reduced to three parts, each of which depends on two spatial coordinates only. The temperatures at the envelope of a canister are given by a single thermal resistance, which is given by an explicit formula. The results are illustrated by a few numerical examples dealing with the KBS-3 concept for storage of nuclear waste. 8 refs.

  3. Numerical algorithm conjugating steady and transient, separated, compressible flow and a solid body having arbitrarily distributed heat sources

    Science.gov (United States)

    Degani, D.

    1984-01-01

    A numerical algorithm that is second-order accurate in time has been developed for the conjugated problem of a separated, compressible flow field and a conductive solid body. The full two-dimensional time-dependent Navier-Stokes equations are coupled with the time-dependent energy equation for the solid body and are solved simultaneously. using implicit algorithms. The energy equation for the solid body may include arbitrarily distributed heat sources. The algorithm has been exmined for the case of two-dimensional supersonic compression-corner interaction, with a heat source embedded in the wall in the vicinity of the separation bubble and the attached boundary layer. The effect of the heat source on the flow field is studied for steady and transient cases.

  4. 污水源热泵技术应用%The sewage-source heat pump technology application

    Institute of Scientific and Technical Information of China (English)

    张永清; 那威

    2016-01-01

    This paper introduced the typical sewage-source heat pump system engineering at home and abroad,analyzed the advantages and dis-advantages of sewage-source heat pump system,and elaborated four principles promotion of sewage-source heat pump technology,conducive to the popularization and application and continuous development of the technology in our country.%对国内外典型的污水源热泵系统工程进行了介绍,分析了污水源热泵系统的优缺点,并阐述了推广污水源热泵技术应遵循的四项原则,有利于该技术在我国的推广应用与不断发展。

  5. Optimization of the Changing Phase Fluid in a Carnot Type Engine for the Recovery of a Given Waste Heat Source

    Directory of Open Access Journals (Sweden)

    Mathilde Blaise

    2015-07-01

    Full Text Available A Carnot type engine with a changing phase during the heating and the cooling is modeled with its thermal contact with the heat source. In a first optimization, the optimal high temperature of the cycle is determined to maximize the power output. The temperature and the mass flow rate of the heat source are given. This does not take into account the converter internal fluid and its mass flow rate. It is an exogenous optimization of the converter. In a second optimization, the endogenous optimization, the isothermal heating corresponds only to the vaporization of the selected fluid. The maximization of the power output gives the optimal vaporization temperature of the cycled fluid. Using these two optima allows connecting the temperature of the heat source to the working fluid used. For a given temperature level, mass flow rate and composition of the waste heat to recover, an optimal fluid and its temperature of vaporization are deduced. The optimal conditions size also the internal mass flow rate and the compression ratio (pump size. The optimum corresponds to the maximum of the power output and must be combined with the environmental fluid impact and the technological constraints.

  6. Effect of rotational speed modulation on heat transport in a fluid layer with temperature dependent viscosity and internal heat source

    Directory of Open Access Journals (Sweden)

    B.S. Bhadauria

    2014-12-01

    Full Text Available In this paper, a theoretical investigation has been carried out to study the combined effect of rotation speed modulation and internal heating on thermal instability in a temperature dependent viscous horizontal fluid layer. Rayleigh–Bénard momentum equation with Coriolis term has been considered to describe the convective flow. The system is rotating about it is own axis with non-uniform rotational speed. In particular, a time-periodic and sinusoidally varying rotational speed has been considered. A weak nonlinear stability analysis is performed to find the effect of modulation on heat transport. Nusselt number is obtained in terms of amplitude of convection and internal Rayleigh number, and depicted graphically for showing the effects of various parameters of the system. The effect of modulated rotation speed is found to have a stabilizing effect for different values of modulation frequency. Further, internal heating and thermo-rheological parameters are found to destabilize the system.

  7. System for vaporizing carbon dioxide utilizing the heat by-product of the refrigeration system as a heat source

    Energy Technology Data Exchange (ETDEWEB)

    Shaw, H.L.

    1980-12-23

    The present invention is directed to a carbonation and refrigeration system wherein the heat of the refrigerant output side of the refrigeration compressor is utilized to vaporize liquid carbon dioxide into CO/sub 2/ gas which is introduced into a liquid product. The carbonation and refrigeration system successfully utilizes the heat of the refrigerant to vaporize the CO/sub 2/ liquid regardless of the cooling demand of the system caused by seasonal temperature variations. For example during the winter months when the cooling demand is as low as 10% of the cooling demand in the summer, the carbonation and refrigeration system operates effectively to vaporize the CO/sub 2/ liquid by means of a heat exchanger and a desuperheater which are connected in communication with the superheated vapor emerging from the output side of a refrigeration compressor. In addition, the carbonation and refrigeration system of the present invention cools more efficiently by extracting some of the heat from the condensed refrigerant entering the receiver of the refrigeration system. In this manner, the refrigeration compressor can operate more efficiently.

  8. Decision support for optimal location of local heat source for small district heating system on the example of biogas plant

    Directory of Open Access Journals (Sweden)

    Ciapała Bartłomiej

    2017-01-01

    Full Text Available Developing a new district heating system requires making decisions affecting entire range of following activities and wellness of the system. The article presents methodics of choosing optimal location and crucial customers with three approaches to optimisation process, discuss obtained results and obstacles. Further improvements and potential applications are named.

  9. Effects of Radiation and free Convection Currents on Unsteady Couette Flow between two Vertical Parallel Plates with Constant Heat flux and Heat Source Through Porous Medium

    Directory of Open Access Journals (Sweden)

    Damala Ch Kesavaiah

    2013-04-01

    Full Text Available The present study the free convection in unsteady Couette flow of a viscous incompressible fluid confined between two vertical parallel plates in the presence of thermal radiation with heat source in the presence of uniform magnetic field is presented. The flow is induced by means of Couette motion and free convection currents occurring as a result of application of constant heat flux on the wall with a uniform vertical motion in its own plane while constant temperature on the stationary wall. The fluid considered here is a gray, absorbing-emitting but non-scattering medium, and the Rosseland approximation is used to describe the radiative heat flux in the analysis. The dimensionless governing partial differential equations are solved by using regular perturbation technique. The results for the velocity, temperature and the skin-friction are shown graphically. The effects of different parameters are discussed.

  10. STAR: The Secure Transportable Autonomous Reactor System - Encapsulated Fission Heat Source

    Energy Technology Data Exchange (ETDEWEB)

    Ehud Greenspan

    2003-10-31

    OAK-B135 The Encapsulated Nuclear Heat Source (ENHS) is a novel 125 MWth fast spectrum reactor concept that was selected by the 1999 DOE NERI program as a candidate ''Generation-IV'' reactor. It uses Pb-Bi or other liquid-metal coolant and is intended to be factory manufactured in large numbers to be economically competitive. It is anticipated to be most useful to developing countries. The US team studying the feasibility of the ENHS reactor concept consisted of the University of California, Berkeley, Argonne National Laboratory (ANL), Lawrence Livermore National Laboratory (LLNL) and Westinghouse. Collaborating with the US team were three Korean organizations: Korean Atomic Energy Research Institute (KAERI), Korean Advanced Institute for Science and Technology (KAIST) and the University of Seoul, as well as the Central Research Institute of the Electrical Power Industry (CRIEPI) of Japan. Unique features of the ENHS include at least 20 years of operation without refueling; no fuel handling in the host country; no pumps and valves; excess reactivity does not exceed 1$; fully passive removal of the decay heat; very small probability of core damaging accidents; autonomous operation and capability of load-following over a wide range; very long plant life. In addition it offers a close match between demand and supply, large tolerance to human errors, is likely to get public acceptance via demonstration of superb safety, lack of need for offsite response, and very good proliferation resistance. The ENHS reactor is designed to meet the requirements of Generation IV reactors including sustainable energy supply, low waste, high level of proliferation resistance, high level of safety and reliability, acceptable risk to capital and, hopefully, also competitive busbar cost of electricity.

  11. Implicit Solution of Non-Equilibrium Radiation Diffusion Including Reactive Heating Source in Material Energy Equation

    Energy Technology Data Exchange (ETDEWEB)

    Shumaker, D E; Woodward, C S

    2005-05-03

    In this paper, the authors investigate performance of a fully implicit formulation and solution method of a diffusion-reaction system modeling radiation diffusion with material energy transfer and a fusion fuel source. In certain parameter regimes this system can lead to a rapid conversion of potential energy into material energy. Accuracy in time integration is essential for a good solution since a major fraction of the fuel can be depleted in a very short time. Such systems arise in a number of application areas including evolution of a star and inertial confinement fusion. Previous work has addressed implicit solution of radiation diffusion problems. Recently Shadid and coauthors have looked at implicit and semi-implicit solution of reaction-diffusion systems. In general they have found that fully implicit is the most accurate method for difficult coupled nonlinear equations. In previous work, they have demonstrated that a method of lines approach coupled with a BDF time integrator and a Newton-Krylov nonlinear solver could efficiently and accurately solve a large-scale, implicit radiation diffusion problem. In this paper, they extend that work to include an additional heating term in the material energy equation and an equation to model the evolution of the reactive fuel density. This system now consists of three coupled equations for radiation energy, material energy, and fuel density. The radiation energy equation includes diffusion and energy exchange with material energy. The material energy equation includes reaction heating and exchange with radiation energy, and the fuel density equation includes its depletion due to the fuel consumption.

  12. Regional Heat Sources and the Active and Break Phases of Boreal Summer Intraseasonal Variability

    Energy Technology Data Exchange (ETDEWEB)

    Annamalai, H; Sperber, K R

    2003-12-15

    The boreal summer intraseasonal variability (BSISV) associated with the 30-50 day mode is represented by the co-existence of three components, poleward propagation of convection over the Indian and tropical west Pacific longitudes and eastward propagation along the equator. The hypothesis that the three components influence each other has been investigated using observed OLR, NCEP-NCAR reanalysis, and solutions from an idealized linear model. The null hypothesis is that the three components are mutually independent. Cyclostationary EOF (CsEOF) analysis is applied on filtered OLR to extract the life-cycle of the BSISV. The dominant mode of CsEOF is significantly tied to observed rainfall over the Indian subcontinent. The components of the heating patterns from CsEOF analysis serve as prescribed forcings for the linear model. This allows us to ascertain which heat sources and sinks are instrumental in driving the large-scale monsoon circulation during the BSISV life-cycle. We identify three new findings: (1) the circulation anomalies that develop as a Rossby wave response to suppressed convection over the equatorial Indian Ocean associated with the previous break phase of the BSISV precondition the ocean-atmosphere system in the western Indian Ocean and trigger the next active phase of the BSISV, (2) the development of convection over the tropical west Pacific forces descent anomalies to the west. This, in conjunction with the weakened cross-equatorial flow due to suppressed convective anomalies over the equatorial Indian Ocean reduce the tropospheric moisture over the Arabian Sea, and promote westerly wind anomalies that do not recurve over India. As a result the low-level cyclonic vorticity shifts from India to southeast Asia and break conditions are initiated over India, and (3) the circulation anomalies forced by equatorial Indian Ocean convective anomalies significantly influence the active/break phases over the tropical west Pacific. Our model solutions support

  13. Integration of available regenerative energy sources in community networks for both electricity and heating

    Energy Technology Data Exchange (ETDEWEB)

    Alcalde Melo, Henrique

    2013-03-06

    In the last years, energy prices for German households have been increasing constantly. Some reasons for that include: the dependency of Germany on external fossil fuels to supply its energy demand, the decision to invest in renewable energy generation and to shut down all its nuclear power plants. Nowadays households are already able to generate energy on-site, however the generation potential depends on climatic conditions as well as the specific location and the type of the building. The aim of this work is to evaluate whether a community of new efficient single-family houses can generate enough energy on-site to supply its electricity and heating demand over the year based on renewable energy sources and with the support of energy storage systems, including electric vehicles. The theoretical community is situated in the city of Cottbus, Germany. For this community, an electricity load profile was designed based on the use of common devices and separated in controllable and uncontrollable loads. Electricity is generated on-site through photovoltaic panels and small wind turbines, and the electricity generation potential is evaluated based on the community's available space, which is rather limited, and the actual regulations in the State of Brandenburg. A comparison of the available technologies to supply the heating demand as well as to store energy in the household sector is presented and discussed. It is assumed that each household has an electric vehicle that can be charged and also discharged in the community as an extra energy storage system. A software simulation system was designed with which an energy balance analysis is carried out based on hourly values of supply and demand. Under the assumptions taken for this study, the results of the simulation show that the community is able to generate more energy than consumed throughout a year, however in a few occasions there is not enough energy available to supply the community's energy demand

  14. Thermophoresis on boundary layer heat and mass transfer flow of Walters-B fluid past a radiate plate with heat sink/source

    Science.gov (United States)

    Vasu, B.; Gorla, Rama Subba Reddy; Murthy, P. V. S. N.

    2016-09-01

    The Walters-B liquid model is employed to simulate medical creams and other rheological liquids encountered in biotechnology and chemical engineering. This rheological model introduces supplementary terms into the momentum conservation equation. The combined effects of thermal radiation and heat sink/source on transient free convective, laminar flow and mass transfer in a viscoelastic fluid past a vertical plate are presented by taking thermophoresis effect into account. The transformed conservation equations are solved using a stable, robust finite difference method. A parametric study illustrating the influence of viscoelasticity parameter (Γ), thermophoretic parameter (τ), thermal radiation parameter (F), heat sink/source (ϕ), Prandtl number (Pr), Schmidt number (Sc), thermal Grashof number (Gr), solutal Grashof number (Gm), temperature and concentration profiles as well as local skin-friction, Nusselt and Sherwood number is conducted. The results of this parametric study are shown graphically and inform of table. The study has applications in polymer materials processing.

  15. Thermophoresis on boundary layer heat and mass transfer flow of Walters-B fluid past a radiate plate with heat sink/source

    Science.gov (United States)

    Vasu, B.; Gorla, Rama Subba Reddy; Murthy, P. V. S. N.

    2017-05-01

    The Walters-B liquid model is employed to simulate medical creams and other rheological liquids encountered in biotechnology and chemical engineering. This rheological model introduces supplementary terms into the momentum conservation equation. The combined effects of thermal radiation and heat sink/source on transient free convective, laminar flow and mass transfer in a viscoelastic fluid past a vertical plate are presented by taking thermophoresis effect into account. The transformed conservation equations are solved using a stable, robust finite difference method. A parametric study illustrating the influence of viscoelasticity parameter ( Γ), thermophoretic parameter ( τ), thermal radiation parameter ( F), heat sink/source ( ϕ), Prandtl number ( Pr), Schmidt number ( Sc), thermal Grashof number ( Gr), solutal Grashof number ( Gm), temperature and concentration profiles as well as local skin-friction, Nusselt and Sherwood number is conducted. The results of this parametric study are shown graphically and inform of table. The study has applications in polymer materials processing.

  16. Discussion on the Ground Source Heat Pump Pechnology%浅谈地源热泵技术

    Institute of Scientific and Technical Information of China (English)

    齐游洋; 辛立民

    2015-01-01

    The ground source heat pump system is the use of shallow geothermal heating and cooling system can be used in a new type of energy. Efficient use of ground source heat pump technology offers cold energy to the building, in order to meet a variety of building functions, for easy, fast and comfortable en-vironment is the goal of ground source heat pump technology. In order to solve the problem of building energy consumption is too serious, the best way is to research more new and renewable en-ergy, so as to achieve the purpose of building energy efficiency. This paper details the principle of ground source heat pump tech-nology, as well as ground-source heat pump classification and characteristics, and prospects of its development prospects.%地源热泵系统是利用浅层地能进行供热制冷的新型能源所使用的系统。高效利用地源热泵技术提供给建筑的冷热能量,以满足建筑的各种使用功能,实现方便、快捷、舒适的环境,是地源热泵技术实现的目标。为了解决建筑耗能过于严重的问题,最好的办法就是更多地去研究新的可再生能源,从而达到建筑节能的目的。本文主要详细阐述了地源热泵技术的原理,以及地源热泵的分类及其特点,并展望其发展前景。

  17. MHD effects on heat transfer over stretching sheet embedded in porous medium with variable viscosity, viscous dissipation and heat source/sink

    Directory of Open Access Journals (Sweden)

    Hunegnaw Dessie

    2014-09-01

    Full Text Available In this analysis, MHD boundary layer flow and heat transfer of a fluid with variable viscosity through a porous medium towards a stretching sheet by taking in to the effects of viscous dissipation in presence of heat source/sink is considered. The symmetry groups admitted by the corresponding boundary value problem are obtained by using Lie’s scaling group of transformations. These transformations are used to convert the partial differential equations of the governing equations into self-similar non-linear ordinary differential equations. Numerical solutions of these equations are obtained by Runge-Kutta fourth order with shooting method. Numerical results obtained for different parameters such as viscosity variation parameter A, permeability parameter k1, heat source/sink parameter λ, magnetic field parameter M, Prandtl number Pr, and Eckert number Ec are drawn graphically and effects of different flow parameters on velocity and temperature profiles are discussed. The skin-friction coefficient -f″(0 and heat transfer coefficient −θ′(0 are presented in tables.

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

    Directory of Open Access Journals (Sweden)

    Markus Preißinger

    2017-02-01

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

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

    Directory of Open Access Journals (Sweden)

    Yongmin Yang

    2017-01-01

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

  20. Analytical Solution of the Hyperbolic Heat Conduction Equation for Moving Semi-Infinite Medium under the Effect of Time-Dependent Laser Heat Source

    Directory of Open Access Journals (Sweden)

    R. T. Al-Khairy

    2009-01-01

    source, whose capacity is given by (,=((1−− while the semi-infinite body has insulated boundary. The solution is obtained by Laplace transforms method, and the discussion of solutions for different time characteristics of heat sources capacity (constant, instantaneous, and exponential is presented. The effect of absorption coefficients on the temperature profiles is examined in detail. It is found that the closed form solution derived from the present study reduces to the previously obtained analytical solution when the medium velocity is set to zero in the closed form solution.

  1. 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...

  2. MHD Heat and Mass Transfer of Chemical Reaction Fluid Flow over a Moving Vertical Plate in Presence of Heat Source with Convective Surface Boundary Condition

    Directory of Open Access Journals (Sweden)

    B. R. Rout

    2013-01-01

    Full Text Available This paper aims to investigate the influence of chemical reaction and the combined effects of internal heat generation and a convective boundary condition on the laminar boundary layer MHD heat and mass transfer flow over a moving vertical flat plate. The lower surface of the plate is in contact with a hot fluid while the stream of cold fluid flows over the upper surface with heat source and chemical reaction. The basic equations governing the flow, heat transfer, and concentration are reduced to a set of ordinary differential equations by using appropriate transformation for variables and solved numerically by Runge-Kutta fourth-order integration scheme in association with shooting method. The effects of physical parameters on the velocity, temperature, and concentration profiles are illustrated graphically. A table recording the values of skin friction, heat transfer, and mass transfer at the plate is also presented. The discussion focuses on the physical interpretation of the results as well as their comparison with previous studies which shows good agreement as a special case of the problem.

  3. The Earth's mantle in a microwave oven: thermal convection driven by a heterogeneous distribution of heat sources

    Science.gov (United States)

    Fourel, Loïc; Limare, Angela; Jaupart, Claude; Surducan, Emanoil; Farnetani, Cinzia G.; Kaminski, Edouard C.; Neamtu, Camelia; Surducan, Vasile

    2017-08-01

    Convective motions in silicate planets are largely driven by internal heat sources and secular cooling. The exact amount and distribution of heat sources in the Earth are poorly constrained and the latter is likely to change with time due to mixing and to the deformation of boundaries that separate different reservoirs. To improve our understanding of planetary-scale convection in these conditions, we have designed a new laboratory setup allowing a large range of heat source distributions. We illustrate the potential of our new technique with a study of an initially stratified fluid involving two layers with different physical properties and internal heat production rates. A modified microwave oven is used to generate a uniform radiation propagating through the fluids. Experimental fluids are solutions of hydroxyethyl cellulose and salt in water, such that salt increases both the density and the volumetric heating rate. We determine temperature and composition fields in 3D with non-invasive techniques. Two fluorescent dyes are used to determine temperature. A Nd:YAG planar laser beam excites fluorescence, and an optical system, involving a beam splitter and a set of colour filters, captures the fluorescence intensity distribution on two separate spectral bands. The ratio between the two intensities provides an instantaneous determination of temperature with an uncertainty of 5% (typically 1K). We quantify mixing processes by precisely tracking the interfaces separating the two fluids. These novel techniques allow new insights on the generation, morphology and evolution of large-scale heterogeneities in the Earth's lower mantle.

  4. Utilisation of bleed steam heat to increase the upper heat source temperature in low-temperature ORC

    Science.gov (United States)

    Mikielewicz, Dariusz; Mikielewicz, Jarosław

    2011-12-01

    In the paper presented is a novel concept to utilize the heat from the turbine bleed to improve the quality of working fluid vapour in the bottoming organic Rankine cycle (ORC). That is a completely novel solution in the literature, which contributes to the increase of ORC efficiency and the overall efficiency of the combined system of the power plant and ORC plant. Calculations have been accomplished for the case when available is a flow rate of low enthalpy hot water at a temperature of 90 °C, which is used for preliminary heating of the working fluid. That hot water is obtained as a result of conversion of exhaust gases in the power plant to the energy of hot water. Then the working fluid is further heated by the bleed steam to reach 120 °C. Such vapour is subsequently directed to the turbine. In the paper 5 possible working fluids were examined, namely R134a, MM, MDM, toluene and ethanol. Only under conditions of 120 °C/40 °C the silicone oil MM showed the best performance, in all other cases the ethanol proved to be best performing fluid of all. Results are compared with the "stand alone" ORC module showing its superiority.

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

    Directory of Open Access Journals (Sweden)

    Jiří Fink

    2016-07-01

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

  6. 地源热泵的地埋管群换热特性研究%Heat transfer characteristics of underground heat exchanger group in ground-source heat pump systems

    Institute of Scientific and Technical Information of China (English)

    於仲义; 陈焰华; 雷建平

    2012-01-01

    结合武汉某实际工程的地埋管群阵列布置情况和地源热泵系统的运行情况,对典型区域的地埋管群运行5年中的埋管换热特性进行了动态数值模拟和分析.提出了温度偏离度和换热保证度的概念,并研究了二者在地源热泵长期运行过程中的变化规律.建议尽量减小冷热负荷不平衡率,以保证地源热泵系统稳定可靠的运行.%Based on the arrangement of the underground heat exchanger group and the operation conditions of the ground-source heat pump system of an actual project in Wuhan, performs a dynamic numerical simulation and analysis of the heat transfer characteristics of the underground heat exchanger group during a five-year operation period in typical zones. Presents the concepts of temperature deviation degree and heat transfer assurance factor, and studies their variation in a long term operation process of ground-source heat pump systems. Proposes that the imbalance rate between cooling and heating load should be reduced as much as possible to ensure the stability and reliability of ground-source heat pump system operation.

  7. Characteristics of Atmospheric Heat Sources over Asia in Summer:Comparison of Results Calculated Using Multiple Reanalysis Datasets

    Institute of Scientific and Technical Information of China (English)

    ZHANG Bo; CHEN Longxun; HE Jinhai; ZHU Congwen; LI Wei

    2009-01-01

    Using 1979-2000 daily NCEP/NCAR (National Centers for Environmental Prediction/National Center for Atmospheric Research) reanalysis data (version 1, hereafter referred to as NCEP1; version 2, hereafter referred to as NCEP2), ECMWF (European Center for Medium-range Weather Forecasts) reanalysis data (ERA), and the Global Asian Monsoon Experiment (GAME) reanalysis data in summer 1998, the vertically integrated heat source (Q1) in summer is calculated, and results obtained using different datasets are com-pared. The distributions of (Q1) calculated by using NCEP1 are in good agreement with rainfall observations over the Arabian Sea/Indian Peninsula, the Bay of Bengal (BOB), and East China. The distributions of (Q1)revealed by using NCEP2 are unrealistic in the southern Indian Peninsula, the BOB, and the South China Sea. Using ERA, the heat sources over the tropical Asia are in accordance with the summer precipitation,however, the distributions of (Q1) in East China are unreasonable. In the tropical region, the distributions of the summer heat source given by NCEP1 and ERA seem to be more accurate than those revealed by NCEP2. The NCEP1 and NCEP2 data are better for calculating heat sources over the subtropical and eastern regions of mainland China.

  8. Optimization design and compare of different solar-ground source heat pump system of office building in cold regions

    Science.gov (United States)

    Xie, H.; He, S.; Fu, Y.

    2016-08-01

    This paper presents two different operation modes of Solar-Ground Source Heat Pump System (SGSHP(S)). With the simulation tool TRNSYS, two different SGSHP system models were built to taking simulation. After making analysis and compare of different simulation results, series operation mode was believed to be better than parallel in the target building.

  9. Electric Power Supply of Meat Processing Enterprise through Utilization Heat of Compressor Station Secondary Energy Sources in Main Gasline

    Directory of Open Access Journals (Sweden)

    A. Nesenchuk

    2013-01-01

    Full Text Available The paper considers a structure of power consumption by a meat processing enterprise with indication of specific power consumption norms in accordance with product nomenclature. Schemes for supply of the enterprise with heat and cold through utilization of compressor station secondary energy sources in main gasline have been presented in the paper.

  10. On the Technology of Ground Source Heat Pump%浅谈地源热泵技术

    Institute of Scientific and Technical Information of China (English)

    屈东升

    2012-01-01

    The concept of ground source heat pump technology is described. The working principle and classification, the composition of ground source heat pump is introduced. The characteristics and actual application of ground source heat pump is analyzed. It is pointed out that the ground source heat pump which is a renewable energy has broad developing and applying prospects in energy saving and exhaustion-reducing, environmental protection, sustainable development in our country.%阐述地源热泵技术的概念。介绍地源热泵系统的组成部分、工作原理和分类,分析地源热泵系统的特点和实际应用情况。提出地源热泵这种可再生能源在我国节能降耗、生态环保、可持续发展中具有广阔的发展和应用前景。

  11. Gilthead seabream (Sparus aurata) Mx gene promoters respond differentially to IPNV and VHSV infections in RTG-2 cells.

    Science.gov (United States)

    González-Mariscal, J A; Fernández-Trujillo, M A; Alonso, M C; García-Rosado, E; Álvarez, M C; Béjar, J

    2016-03-01

    The understanding of virus-host interactions relies on the knowledge of the regulatory mechanisms of the type I interferon (IFN I)-stimulated genes (ISGs). Among ISGs, those coding Mx proteins play a main role due to their direct antiviral activity. The study of these genes in gilthead seabream is interesting, since this species displays high natural resistance to viral diseases, being asymptomatic carrier of infectious pancreatic necrosis virus (IPNV) and viral haemorrhagic septicaemia virus (VHSV). Gilthead seabream has three Mx genes (Mx1, Mx2, and Mx3), encoding proteins with a wide spectrum of antiviral activity. The structure of the three promoters (pMx1, pMx2 and pMx3) has been previously disclosed, and their response to poly I:C in RTG-2 cells characterized. To further analyze these promoters, their response to two viral infections has been evaluated in the present study. For that purpose, RTG-2 cells transiently transfected with the luciferase gene under the control of each promoter were inoculated with either IPNV or VHSV at two different doses. The highest and lowest fold induction values were recorded for pMx2 and pMx3, respectively. The promoter induction was always stronger after VHSV inoculation than in IPNV-inoculated cells. In addition, the higher dose of VHSV tested induced higher response of the three promoters, whereas in IPNV-infected cells the highest induction was recorded after inoculation with the lower viral dose. To further study the response of the Mx2 promoter, RTG-2 cells stably transfected with the luciferase gene under the control of pMx2 were stimulated with poly I:C and subsequently infected with IPNV or VHSV. Interestingly, IPNV infection inhibited the induction caused by poly I:C, suggesting an antagonistic activity of IPNV on Mx2 transcription. In contrast, VHSV infection did not alter the response triggered by poly I:C. These results highlight the specific regulation that controls the activity of each promoter, and support the

  12. Marangoni convective MHD flow of SWCNT and MWCNT nanoliquids due to a disk with solar radiation and irregular heat source

    Science.gov (United States)

    Mahanthesh, B.; Gireesha, B. J.; Shashikumar, N. S.; Shehzad, S. A.

    2017-10-01

    Present study addresses the Marangoni transport of dissipating SWCNT and MWCNT nanofluids under the influence of magnetic force and radiation. A novel exponential space dependent heat source is considered. The flow is generated due to a disk with surface tension created by thermal gradient. The partial differential equations system governing the flow of carbon-water nanoliquids and heat transfer through Marangoni convection is established. Subsequent system is reduced to nonlinear ordinary boundary value problem via generalized Karman transformations. Numerical solutions are developed of the arising nonlinear problem via Runge-Kutta based shooting approach. Impacts of embedded parameters are focused on Nusselt number, velocity and heat transport distributions through graphical illustrations. Our simulations figured out that the heat transfer rate increased via Marangoni convection; however it is decayed by applied magnetic force. The temperature of SWCNT-H2O nanoliquid dominates MWCNT-H2O nanoliquid.

  13. Thermal power output determination of 2 MW heat source by using of thermocouples

    Science.gov (United States)

    Holubcik, Michal; Vician, Peter; Palacka, Matej

    2016-06-01

    Experiment is an operation or procedure carried out under controlled conditions in order to discover an unknown effect or law, to test or establish a hypothesis, or to illustrate a known law. The most important part of the experiment is to evaluate the measured values. Measurement accuracy depends on a number of factors. Deviations of instruments cannot eliminate or influence if it is neglect the possibility of using more precise measuring equipment. Another way for the most accurate results can be calibration. Calibration allows achieve measurement values with relatively high accuracy using less precision instruments. The paper deals about the problematic of thermal power measurement accuracy. Thermal power was measured on heat source with nominal thermal power 2 MW by using direct calorimetric method. There were used ultrasonic flow meter and type K thermocouples. Type K thermocouples are not very suitable for these applications because of their low precision. The paper presents the possibility of using calibrated thermocouples for the thermal power measurement with acceptable accuracy.

  14. Hydraulic resistance and convective heat transfer within independent power generation micro sources (IPM) channels

    Science.gov (United States)

    V, Sudarev A.; V, Sudarev B.; A, Suryaninov A.

    2012-05-01

    The introduction of new structural materials and technologies contributes to the efficiency increase for the compact IPMs used in various branches of engineering. Use of a driving high-temperature (TIT600K), regenerative (the regeneration ratio is E>85%) micro gas turbine engine μGTE, major components which are made of structural ceramics, allows not only to maintain the effective efficiency at ηe=26-30%, but, also, sharply reduce the material consumption rate for the micro source as a whole. Application of the laser prototyping technique to manufacture the air heater, which is a part of μGTE, increases the IPM compactness. Miniaturization of the air heater, manufactured by the structural ceramics laser fusion, can significantly reduce the hydraulic diameter (dh<=1.0 mm) of the channels, designed to transport the working media inside it. Reducing dh leads to a significant increase in the hydraulic resistance of the micro channels. The associated increase in the energy consumption for μGTE's own needs is compensated by increasing the TIT, E, and heat transfer coefficients in micro channels, and by eliminating the need in cooling for high temperature IPM components.

  15. Development of plasma sources for ICRF heating experiment in KMAX mirror device

    Science.gov (United States)

    Sun, Xuan; Liu, Ming; Yi, Hongshen; Lin, Munan; Shi, Peiyun

    2016-10-01

    KMAX, Keda Mirror with AXisymmeticity, is a tandem mirror machine with a length of 10 meters and diameters of 1.2 meters in the central cell and 0.3 meters in the mirror throat. In the past experiments, the plasma was generated by helicon wave launched from the west end. We obtained the blue core mode in argon discharge, however, it cannot provide sufficient plasma for hydrogen discharge, which is at least 1012 cm-3 required for effective ICRF heating. Several attempts have thus been tried or under design to increase the central cell's plasma density: (1) a washer gun with aperture of 1cm has been successfully tested, and a plasma density of 1013 cm-3 was achieved in the west cell near the gun, however, the plasma is only 1011 cm-3 in the central cell possible due to the mirror trapping and/or neutral quenching effect (2) a larger washer gun with aperture of 2.5 cm and a higher power capacitor bank are being assembled in order to generate more plasmas. In addition, how to mitigate the neutrals is under consideration (3) A hot cathode is been designed and will be tested in combination with plasma gun or alone. Preliminary results from those plasma sources will be presented and discussed.

  16. Simulations of the L H transition dynamics with different heat and particle sources

    Institute of Scientific and Technical Information of China (English)

    李会东; 王占辉; Jan Weiland; 冯灏; 孙卫国

    2015-01-01

    It is crucial to increase the total stored energy by realizing the transition from a low confinement (L-mode) state to a high confinement (H-mode) state in magnetic confinement fusion. The L–H transition process is simulated by using the predictive transport code based on Weiland’s fl uid model. Based on the equilibrium parameters obtained from equilibrium fitting (EFIT) in the experiment, the electron density ne, electron temperature Te, ion temperatures Ti, ion poloidal Vp, and toroidal momenta Vt are simulated self-consistently. The L–H transition dynamic behaviors with the formation of the transport barriers of ion and electron temperatures, the electron density, and the ion toroidal momenta are analyzed. During the L–H transition, the strong poloidal fl ow shear in the edge transport barrier region is observed. The crashes of the electron and ion temperature pedestals are also observed during the L–H transition. The effects of the heating and particle sources on the L–H transition process are studied systematically, and the critical power threshold of the L–H transition is also found.

  17. Long-term Performance of Moderate Heat Portland Cement with Double-expansive Sources

    Institute of Scientific and Technical Information of China (English)

    YE Qing; CHEN Huxing; KONG Deyu; WANG Shangxian; LOU Zonghan

    2007-01-01

    The long-term performance of moderate heat Portland cement with double-expansive sources (DE cement) in the system of high MgO clinker and gypsum was studied by XRD, SEM/EDAX and test methods for strength and expansion of cement. Results indicate that the periclase particle, whose size was 5-7.5 μm in DE cement clinker containing 4.8 % MgO, existed individually. The periclase hydration in hardened DE cement paste started at about 60 days and completed up to 2 000 days, and ettringite in the paste was stable from 3 days to 2 000 days. Under the conditions of 4.5%-5.0 % MgO in clinker and 2.8%-3.4 %SO3 in cement,ettringite expansion and brucite expansion in DE cement paste had a continuity, entirety and stability. At the ages of 90, 365, 730 and 2 000 days the expansion of the paste reached 0.07%-0.11%, 0.16%-0.21%, 0.21%-0.27% and 0.29%-0.38 %, respectively. The results suggest that by using this cement in mass concrete it may compensate its temperature shrinkage and autogenous shrinkage to some extent.

  18. A computational study of droplet evaporation with fuel vapor jet ejection induced by localized heat sources

    KAUST Repository

    Sim, Jaeheon

    2015-05-12

    Droplet evaporation by a localized heat source under microgravity conditions was numerically investigated in an attempt to understand the mechanism of the fuel vapor jet ejection, which was observed experimentally during the flame spread through a droplet array. An Eulerian-Lagrangian method was implemented with a temperature-dependent surface tension model and a local phase change model in order to effectively capture the interfacial dynamics between liquid droplet and surrounding air. It was found that the surface tension gradient caused by the temperature variation within the droplet creates a thermo-capillary effect, known as the Marangoni effect, creating an internal flow circulation and outer shear flow which drives the fuel vapor into a tail jet. A parametric study demonstrated that the Marangoni effect is indeed significant at realistic droplet combustion conditions, resulting in a higher evaporation constant. A modified Marangoni number was derived in order to represent the surface force characteristics. The results at different pressure conditions indicated that the nonmonotonic response of the evaporation rate to pressure may also be attributed to the Marangoni effect.

  19. Heat Loss in a Laser-Driven, Magnetized, X-Ray Source with Thermoelectric Terms

    Science.gov (United States)

    Giuliani, J. L.; Velikovich, A. L.; Kemp, G. E.; Colvin, J. D.; Koning, J.; Fournier, K. B.

    2016-10-01

    The efficiency of laser-driven K-shell radiation sources, i.e., pipes containing a gas or a metal foam, may be improved by using an axial magnetic field to thermally insulate the pipe wall from the hot interior. A planar, self-similar solution for the magnetic and thermal diffusion is developed to model the near wall physics that includes the thermoelectric Nernst and Ettingshausen effects. This solution extends previous work for the MagLIF concept to include the full dependence of the transport coefficients on the electron Hall parameter. The analytic solution assumes a constant pressure. This case is matched with a 1D MHD code, which is then applied to the case allowing for pressure gradients. These numerical solutions are found to evolve toward the self-similar ones. The variation of the time integrated heat loss with and without the thermoelectric terms will be examined. The present work provides a verification test for general MHD codes that use Braginskii's or Epperlein-Haines' transport model to account for thermoelectric effects. NRL supported by the DOE/NNSA. LLNL work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract No. DE-AC52-07NA27344.

  20. Evaluation of federal and state subsidies for ground-source heat pumps

    Energy Technology Data Exchange (ETDEWEB)

    Blumsack, S.; Kleit, A. [Department of Energy and Mineral Engineering, The Pennsylvania State University, 213 Hosler Building University Park, PA (United States); Smith, S.W. [Westcott Consulting, 110 Hosler Building, Boulder, CO (United States)

    2012-08-15

    Energy efficiency can be a powerful way to lower energy bills, as well as the external (social) costs associated with energy consumption. Previous experience and research, however, has demonstrated that consumers are often unwilling to make investments in energy efficiency, even when such investments have relatively short payback periods. Because energy efficiency can contribute to correcting negative externalities associated with energy use, subsidies and other programs have been proposed as a way to increase efficiency investments. Thus, under the right circumstances, such subsidies can improve economic efficiency. In this paper, we analyze the economics of energy-efficient space conditioning using data from an actual household in rural Pennsylvania to evaluate ground-source heat pumps (GHP). GHP technology has been advocated as a potentially appealing energy efficiency measure for rural communities. We find that with current subsidies GHP is economically viable for a wide range of electricity prices. We also find, however, that current subsidies are actually greater than those that can be economically justified. Using the efficient level of subsidies reduces, but does not eliminate, the economic case for GHP technology. We also evaluate the economics of efficiency subsidies using an ambitious program in Pennsylvania as a case study. The program, known as the Alternative Energy Investment Act (AEIA), provides subsidies for GHP among other technologies. We find that the substantial federal subsidies for GHP undercut the economic efficiency arguments for the AEIA with respect to GHP.

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

    Directory of Open Access Journals (Sweden)

    Sameh E. Ahmed

    2016-03-01

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

  2. Tau causes synapse loss without disrupting calcium homeostasis in the rTg4510 model of tauopathy.

    Directory of Open Access Journals (Sweden)

    Katherine J Kopeikina

    Full Text Available Neurofibrillary tangles (NFTs of tau are one of the defining hallmarks of Alzheimer's disease (AD, and are closely associated with neuronal degeneration. Although it has been suggested that calcium dysregulation is important to AD pathogenesis, few studies have probed the link between calcium homeostasis, synapse loss and pathological changes in tau. Here we test the hypothesis that pathological changes in tau are associated with changes in calcium by utilizing in vivo calcium imaging in adult rTg4510 mice that exhibit severe tau pathology due to over-expression of human mutant P301L tau. We observe prominent dendritic spine loss without disruptions in calcium homeostasis, indicating that tangles do not disrupt this fundamental feature of neuronal health, and that tau likely induces spine loss in a calcium-independent manner.

  3. Shallow Groundwater Temperatures and the Urban Heat Island Effect: the First U.K City-wide Geothermal Map to Support Development of Ground Source Heating Systems Strategy

    Science.gov (United States)

    Patton, Ashley M.; Farr, Gareth J.; Boon, David P.; James, David R.; Williams, Bernard; Newell, Andrew J.

    2015-04-01

    The first UK city-wide heat map is described based on measurements of groundwater from a shallow superficial aquifer in the coastal city of Cardiff, Wales, UK. The UK Government has a target of reducing greenhouse gas emissions by 80% by 2050 (Climate Change Act 2008) and low carbon technologies are key to achieving this. To support the use of ground source heating we characterised the shallow heat potential of an urban aquifer to produce a baseline dataset which is intended to be used as a tool to inform developers and to underpin planning and regulation. We exploited an existing network of 168 groundwater monitoring boreholes across the city, recording the water temperature in each borehole at 1m depth intervals up to a depth of 20m. We recorded groundwater temperatures during the coldest part of 2014, and repeat profiling of the boreholes in different seasons has added a fourth dimension to our results and allowed us to characterise the maximum depth of seasonal temperature fluctuation. The temperature profiles were used to create a 3D model of heat potential within the aquifer using GOCAD® and the average borehole temperatures were contoured using Surfer® 10 to generate a 2D thermal resource map to support future assessment of urban Ground Source Heat Pumps prospectively. The average groundwater temperature in Cardiff was found to be above the average for England and Wales (11.3°C) with 90% of boreholes in excess of this figure by up to 4°C. The subsurface temperature profiles were also found to be higher than forecast by the predicted geothermal gradient for the area. Potential sources for heat include: conduction from buildings, basements and sub-surface infrastructure; insulation effects of the urban area and of the geology, and convection from leaking sewers. Other factors include recharge inhibition by drains, localised confinement and rock-water interaction in specific geology. It is likely to be a combination of multiple factors which we are hoping

  4. 土壤源热泵系统地下温度场的热平衡模拟分析%On heat balance simulation analysis of temperature field in ground heat source heat pump system

    Institute of Scientific and Technical Information of China (English)

    宋智军

    2012-01-01

    以成都来福士广场的土壤源热泵工程为例,采用Fluent6.2软件的TransientSolver模块对该项目的地下温度场进行了模拟计算,分别按照土壤源热泵间歇运行模式和连续运行模式来模拟计算地下温度场20年,从模拟结果可以清楚的看到,间歇运行模式下土壤的热平衡状况良好,突出了地下温度场的取热量和排热量的平衡是保证土壤源热泵系统长期稳定运行的重要因素。%Taking the project of the ground source heat pump on Laifushi Square of Chengdu as the example, the paper adopts the Transient Solver Module of the Fluent6.2 software to have the simulation calculation for the underground temperature field of the program, simulates and cal- culates the twenty years of the underground temperature field by adopting the intermittent operation module and its continuous operation one of the ground source heat pump, and shows from the simulation result that the heat balance of the soil in the intermittent operation module has better heat balance, and highlights the balance of the accumulated heat and the extracted heat of the underground temperature field is important for en- suring the long-term and stable operation of the ground source heat pump.

  5. Performance of a 250 kW Organic Rankine Cycle System for Off-Design Heat Source Conditions

    Directory of Open Access Journals (Sweden)

    Ben-Ran Fu

    2014-06-01

    Full Text Available An organic Rankine cycle system comprised of a preheater, evaporator, condenser, turbine, generator, and pump was used to study its off-design performance and the operational control strategy. R245fa was used as the working fluid. Under the design conditions, the net power output is 243 kW and the system thermal efficiency is 9.5%. For an off-design heat source flow rate (mW, the operating pressure was controlled to meet the condition that the R245fa reached the liquid and vapor saturation states at the outlet of the preheater and the evaporator, respectively. The analytical results demonstrated that the operating pressure increased with increasing mW; a higher mW yielded better heat transfer performance of the preheater and required a smaller evaporator heat capacity, and the net power output and system thermal efficiency increased with increasing mW. For the range of mW studied here, the net power output increased by 64.0% while the total heat transfer rate increased by only 9.2%. In summary, off-design operation of the system was examined for a heat source flow rate which varied by –39.0% to +78.0% from the designed rate, resulting in –29.2% to +16.0% and –25.3% to +12.6% variations in the net power output and system thermal efficiency, respectively.

  6. Hydrothermal-flow regime and magmatic heat source of the Cerro Prieto geothermal system, Baja California, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Elders, W.A.; Bird, D.K.; Williams, A.E.; Schiffman, P.

    1982-01-01

    This detailed three-dimensional model of the natural flow regime of the Cerro Prieto geothermal field, before steam production began, is based on patterns of hydrothermal mineral zones and light stable isotopic ratios observed in rock samples from more than fifty deep wells, together with temperature gradients, wireline logs and other data. At the level so far penetrated by drilling, this hydrothermal system was heated by a thermal plume of water close to boiling, inclined at 45/sup 0/, rising from the northeast and discharging to the west. To the east a zone of cold water recharge overlies the inclined thermal plume. Fission track annealing studies shows that the reservoir reached 170/sup 0/C only 10/sup 4/ years ago. Oxygen isotope exchange data indicate that a 12 km/sup 3/ volume of rock subsequently reacted with three times its volume of water hotter than 200/sup 0/C. Averaged over the duration of the heating event this would require a flow velocity of about 6 m/year through the pores of a typical cross section of the reservoir having an average porosity of 10%. Although this is an extensional tectonic environment of leaky transform faulting in which repeated intrusions of basalt magma are likely, for simplicity of computation possible heat sources were modelled as simple two dimensional basalt intrusions of various sizes, shapes and locations. We have calculated a series of two-dimensional convective heat transfer models, with different heat sources and permeability distributions. The models which produce the best fit for the temperature distributions observed in the field today have in common a heat source which is a funnel-shaped basalt intrusion, 4 km wide at the top, emplaced at a depth of 5 km to 6 km about 40,000 to 50,000 years ago.

  7. Optimum bleeding rate of open loop ground source heat pump systems determined by hydrogeological modeling in Korea

    Science.gov (United States)

    Jeon, W. H.; Kim, N.; Lee, J. Y.

    2014-12-01

    This study aims to evaluate the influence of open loop ground source heat pump systems operation on hydrological conditions of aquifer. Test bed is located in Chuncheon, Korea. The step drawdown test was conducted in five stages for 300 minutes. The variation of groundwater levels by open loop ground source heat pump systems operation was estimated using Visual MODFLOW. Transmissivity ranged from 2.02×10-4 to 9.36×10-4, and storage coefficient ranged from 0.00067 to 0.021. The amount of optimum bleeding was calculated to be 240 m3/day. When bleeding will be 50, 90, 240 and 450 m3/day for 5 years, groundwater levels may decrease 1.84, 3.31, 8.89 and 17.0 m, respectively. If the amount of bleeding is 50 m3/day, the influence of bleeding will not reach the boundary regions of the Soyang River after 5 years. Regarding the open loop ground source heat pump system installed at the test bed, the amount of optimum bleeding in accordance with the stand are proposed by the government is 90 m3/day, which is 20% of the 450 m3/day circulation quantity of the system. However, if continuous bleeding of more than 90 m3/day occurs, then the radius of influence is expected to reach the boundary regions of the Soyang River after 5 years. These results indicate that amount of optimum bleeding differ in each open loop ground soured heat pump system. Therefore, the debate for the amount of optimum bleeding in open loop ground source heat pump systems is demanded. This work is supported by the Energy Efficiency and Resources of the Korea Institute of Energy Technology Evaluation and Planning (KETEP) grant funded by the Korea government Ministry of Knowledge Economy (No.20123040110010).

  8. Hydromagnetic convective flow past a vertical porous plate through a porous medium with suction and heat source

    Directory of Open Access Journals (Sweden)

    S.S.Das, U.K.Tripathy, J.K.Das

    2010-05-01

    Full Text Available This paper theoretically analyzes the unsteady hydromagnetic free convective flow of a viscous incompressible electrically conducting fluid past an infinite vertical porous plate through a porous medium in presence of constant suction and heat source. Approximate solutions are obtained for velocity field, temperature field, skin friction and rate of heat transfer using multi-parameter perturbation technique. The effects of the flow parameters on the flow field are analyzed with the aid of figures and tables. The problem has some relevance in the geophysical and astrophysical studies.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-02-15

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

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

    CERN Document Server

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

    2016-01-01

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

  11. MHD FREE CONVECTION FLOW PAST AN INFINITE VERTICAL PLATE WITH FIRST ORDER CHEMICAL REACTION AND HEAT SOURCE/SINK

    Directory of Open Access Journals (Sweden)

    Dr.Abhay Kumar Jha

    2012-07-01

    Full Text Available The objective of this paper is to study heat and mass transfer on an unsteady two dimensional hydromagnetic laminar mixed convective boundary layer flow of an incompressible fluid past a semi-infinite vertical plate with heat source/ sink. The plate moves with constant velocity in the direction of fluid flow while the free stream velocity follows an exponentially increasing small perturbation law. The dimensionless governing equations are solved analytically using two terms harmonic and non-harmonic functions .the results obtainedand discussed with help of graphs and tables to observe the effect of various parameter concerned in the problem under investigation.

  12. Energy performance of a ventilation system for a block of apartments with a ground source heat pump as generation system

    Science.gov (United States)

    Lucchi, M.; Lorenzini, M.; Valdiserri, P.

    2017-01-01

    This work presents a numerical simulation of the annual performance of two different systems: a traditional one composed by a gas boiler-chiller pair and one consisting of a ground source heat pump (GSHP) both coupled to two thermal storage tanks. The systems serve a bloc of flats located in northern Italy and are assessed over a typical weather year, covering both the heating and cooling seasons. The air handling unit (AHU) coupled with the GSHP exhibits excellent characteristics in terms of temperature control, and has high performance parameters (EER and COP), which make conduction costs about 30% lower than those estimated for the traditional plant.

  13. Dual Solutions of MHD Boundary Layer Flow past an Exponentially Stretching Sheet with Non-Uniform Heat Source/Sink

    Directory of Open Access Journals (Sweden)

    Raju CSK

    2016-01-01

    Full Text Available In this study we analyzed the momentum and heat transfer characteristics of MHD boundary layer flow over an exponentially stretching surface in porous medium in the presence of radiation, non-uniform heat source/sink, external pressure and suction/injection. Dual solutions are presented for both suction and injection cases. The heat transfer analysis is carried out for both prescribed surface temperature (PST and prescribed heat flux (PHF cases. The governing equations of the flow are transformed into system of nonlinear ordinary differential equations by using similarity transformation and solved numerically using bvp4c Matlab package. The impact of various non-dimensional governing parameters on velocity, temperature profiles for both PST and PHF cases, friction factor and rate of heat transfer is discussed and presented with the help of graphs and tables. Results indicate that dual solutions exist only for certain range of suction or injection parameters. It is also observed that the exponential parameter have tendency to increase the heat transfer rate for both PST and PHF cases.

  14. Exact Analytical Solution for 3D Time-Dependent Heat Conduction in a Multilayer Sphere with Heat Sources Using Eigenfunction Expansion Method.

    Science.gov (United States)

    Dalir, Nemat

    2014-01-01

    An exact analytical solution is obtained for the problem of three-dimensional transient heat conduction in the multilayered sphere. The sphere has multiple layers in the radial direction and, in each layer, time-dependent and spatially nonuniform volumetric internal heat sources are considered. To obtain the temperature distribution, the eigenfunction expansion method is used. An arbitrary combination of homogenous boundary condition of the first or second kind can be applied in the angular and azimuthal directions. Nevertheless, solution is valid for nonhomogeneous boundary conditions of the third kind (convection) in the radial direction. A case study problem for the three-layer quarter-spherical region is solved and the results are discussed.

  15. Verification of model for heat and mass transfer process in cross flow heat-source tower%叉流热源塔传热传质模型的建立及实验验证

    Institute of Scientific and Technical Information of China (English)

    文先太; 梁彩华; 刘成兴; 张小松

    2012-01-01

    As a new heat and mass transfer device, heat-source tower plays an important role in the heat-source tower heat pump system. Heat is absorbed from the ambient in winter and supplied to the evaporator of heat pump. There are some similarities and differences in heat and mass transfer between heat-source tower and cooling tower. Six primary differences are pointed out as follows: heat resistance, physical property of liquid, ratio of latent heat percentage, flow rate of circular water/liquid, effect of liquid float on the whole system, and direction and rate of heat transfer. Based on the similarities and differences of heat-source tower and cooling tower, the mathematical model of heat and mass transfer in the cross heat-source tower is proposed and the model is confirmed by experiments. Results show that the latent heat percentage of cross flow heat-source tower is less than 35% and the error of heat transfer rate between simulation and experiment is less than 10%. The model is accurate enough to simulate the heat transfer characteristic in the heat-source tower.%热源塔作为新型的热质交换设备,在热源塔热泵机组运行过程中起着重要作用.其在冬季运行时从空气中吸收热量,为热泵机组提供低品位热量.热源塔与冷却塔在传热传质上存在一定异同点,指出了冷却塔与热源塔在传热传质上存在热阻、液体物性、潜热换热量比例、循环水/液体流量、飘液对系统的影响、热量传递方向和换热量大小等方面的差异.根据热源塔与冷却塔差异建立叉流热源塔传热传质数学模型,并采用实验验证模型的准确性.结果表明叉流热源塔潜热百分比低于35%,模型结果与实验结果相比换热性能误差低于10%,该模型能够较为精确地对叉流热源塔换热性能进行模拟.

  16. ON THE RELATIONSHIPS BETWEEN THE SUMMER RAINFALL IN CHINA AND THE ATMOSPHERIC HEAT SOURCES OVER THE EASTERN TIBETAN PLATEAU AND THE WESTERN PACIFIC WARM POOL

    Institute of Scientific and Technical Information of China (English)

    简茂球; 罗会邦; 乔云亭

    2004-01-01

    The relationships between the summer rainfall in China and the atmospheric heat sources over the eastern Tibetan Plateau and the western Pacific warm pool were analyzed comparatively, using the NCEP/NCAR reanalysis daily data. The strong (weak) heat source in summer over the eastern Tibetan Plateau will lead to abundant (scarce) summer rainfall in the Yangtze River basin, and scarce/abundant summer rainfall in the eastern part of Southern China. While the strong (weak) heat source in summer over the western Pacific warm pool will lead to another pattern of abundant (scarce) summer rainfall in the middle-lower reaches of the Yangtze River and scarce (abundant) summer rainfall in Southern China and in the region of northern Jiangsu to southern Shandong. Comparatively, the heat source over the eastern Tibetan Plateau affects a larger area of summer rainfall than the heat source over the western Pacific. In both cases of the heat source anomalies over the eastern Tibetan Plateau and over the western Pacific, there exist EAP-like teleconnection patterns in East Asia. The summer rainfall in China is influenced directly by the abnormal vertical motion, which is related closely to the abnormal heat sources in the atmosphere. The ridge line of the western Pacific High locates far south (north) in summer in the case of strong (weak) heat sources over the two areas mentioned above.

  17. Heat-shock effects on photosynthesis and sink-source dynamics in wheat (Triticum aestivum L.)

    NARCIS (Netherlands)

    Schapendonk, A.H.C.M.; Xu, H.Y.; Putten, van der P.E.L.; Spiertz, J.H.J.

    2007-01-01

    To assess the mechanisms causing genotypic differences in heat tolerance of wheat (Triticum aestivum L.), physiological responses to a heat shock in a vegetative (`end of tillering¿) or a reproductive (`early grain filling¿) stage were studied. Three cultivars ¿ Lavett, Ciano-79 and Attila ¿

  18. 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.

  19. An Integrated Approach on Groundwater Flow and Heat/Solute Transport for Sustainable Groundwater Source Heat Pump (GWHP) System Operation

    Science.gov (United States)

    Park, D. K.; Bae, G. O.; Joun, W.; Park, B. H.; Park, J.; Park, I.; Lee, K. K.

    2015-12-01

    The GWHP system uses a stable temperature of groundwater for cooling and heating in buildings and thus has been known as one of the most energy-saving and cost-efficient renewable energy techniques. A GWHP facility was installed at an island located at the confluence of North Han and South Han rivers, Korea. Because of well-developed alluvium, the aquifer is suitable for application of this system, extracting and injecting a large amount of groundwater. However, the numerical experiments under various operational conditions showed that it could be vulnerable to thermal interference due to the highly permeable gravel layer, as a preferential path of thermal plume migration, and limited space for well installation. Thus, regional groundwater flow must be an important factor of consideration for the efficient operation under these conditions but was found to be not simple in this site. While the groundwater level in this site totally depends on the river stage control of Paldang dam, the direction and velocity of the regional groundwater flow, observed using the colloidal borescope, have been changed hour by hour with the combined flows of both the rivers. During the pumping and injection tests, the water discharges in Cheongpyeong dam affected their respective results. Moreover, the measured NO3-N concentrations might imply the effect of agricultural activities around the facility on the groundwater quality along the regional flow. It is obvious that the extraction and injection of groundwater during the facility operation will affect the fate of the agricultural contaminants. Particularly, the gravel layer must also be a main path for contaminant migration. The simulations for contaminant transport during the facility operation showed that the operation strategy for only thermal efficiency could be unsafe and unstable in respect of groundwater quality. All these results concluded that the integrated approach on groundwater flow and heat/solute transport is necessary

  20. Heat sources for glacial ice melt in a West Greenland tidewater outlet glacier fjord: The role of subglacial freshwater discharge

    DEFF Research Database (Denmark)

    Bendtsen, Jørgen; Mortensen, John; Lennert, Kunuk

    2015-01-01

    The melting of tidewater outlet glaciers from the Greenland Ice Sheet contributes significantly to global sea level rise. Accelerated mass loss is related to melt-processes in front of calving glaciers, yet the role of ocean heat transports is poorly understood. Here we present the first direct...... measurements from a subglacial plume in front of a calving tidewater outlet glacier. Surface salinity in the plume corresponded to a meltwater content of 7 %, which is indicative of significant entrainment of warm bottom water and, according to plume model calculations, significant ice melt. Energy balance...... of the area near the glacier showed that ice melt was mainly due to ocean heat transport and that direct plume-associated melt was only important in periods with high meltwater discharge rates of ~100 m3 s−1. Ocean mixing outside of the plume area was thus the primary heat source for melting glacier ice....

  1. Heat sources for glacial ice melt in a West Greenland tidewater outlet glacier fjord: The role of subglacial freshwater discharge

    DEFF Research Database (Denmark)

    Bendtsen, Jørgen; Mortensen, John; Lennert, Kunuk

    2015-01-01

    The melting of tidewater outlet glaciers from the Greenland Ice Sheet contributes significantly to global sea level rise. Accelerated mass loss is related to melt-processes in front of calving glaciers, yet the role of ocean heat transports is poorly understood. Here we present the first direct...... measurements from a subglacial plume in front of a calving tidewater outlet glacier. Surface salinity in the plume corresponded to a meltwater content of 7 %, which is indicative of significant entrainment of warm bottom water and, according to plume model calculations, significant ice melt. Energy balance...... of the area near the glacier showed that ice melt was mainly due to ocean heat transport and that direct plume-associated melt was only important in periods with high meltwater discharge rates of ~100 m3 s−1. Ocean mixing outside of the plume area was thus the primary heat source for melting glacier ice....

  2. On the Inverse Problem of the Fractional Heat-Like Partial Differential Equations: Determination of the Source Function

    Directory of Open Access Journals (Sweden)

    Gülcan Özkum

    2013-01-01

    Full Text Available The study in this paper mainly concerns the inverse problem of determining an unknown source function in the linear fractional differential equation with variable coefficient using Adomian decomposition method (ADM. We apply ADM to determine the continuous right hand side functions fx and ft in the heat-like diffusion equations Dtαux,t=hxuxxx,t+fx and Dtαux,t=hxuxxx,t+ft, respectively. The results reveal that ADM is very effective and simple for the inverse problem of determining the source function.

  3. Ground-Source Heat Pumps. Overview of Market Status, Barriers to Adoption, and Options for Overcoming Barriers

    Energy Technology Data Exchange (ETDEWEB)

    Goetzler, William [Navigant Consulting, Inc., Chicago, IL (United States); Zogg, Robert [Navigant Consulting, Inc., Chicago, IL (United States); Lisle, Heather [Navigant Consulting, Inc., Chicago, IL (United States); Burgos, Javier [Navigant Consulting, Inc., Chicago, IL (United States)

    2009-02-03

    February 2009 final report submitted to DOE by Navigant Consulting, Inc. This report summarizes the status of ground-source heat pump (GSHP) technology and market penetration globally, estimates the energy saving potential of GSHPs in the U.S., identifies key market barriers that are inhibiting wider market adoption of GSHPs, and recommends initiatives that can be implemented or facilitated by the DOE to accelerate market adoption.

  4. STAR: The Secure Tranportable Autonomous Reactor system, Encapsulated Fission Heat Source. Progress report for period terminating March 31, 2000

    Energy Technology Data Exchange (ETDEWEB)

    Greenspan, Ehud

    2000-04-24

    Significant progress has been made since the beginning of this project, in September 1999. Part of the project findings are described in References 1 and 2. So far we have found no ''show-stopper''. In fact, based on the findings accumulated so far it appears to us that the Encapsulated Nuclear Heat Source (ENHS) is technologically feasible and looks even more attractive than initially conceived.

  5. An In-Depth Look at Ground Source Heat Pumps and Other Electric Loads in Two GreenMax Homes

    Energy Technology Data Exchange (ETDEWEB)

    Puttagunta, Srikanth [Consortium for Advanced Residential Buildings (CARB), Norwalk, CT (United States); Shapiro, Carl [Consortium for Advanced Residential Buildings (CARB), Norwalk, CT (United States)

    2012-04-01

    Building America research team Consortium for Advanced Residential Buildings (CARB) partnered with WPPI Energy to answer key research questions on in-field performance of ground-source heat pumps and lighting, appliance, and miscellaneous loads (LAMELs) through extensive field monitoring at two WPPI GreenMax demonstration homes in Wisconsin. These two test home evaluations provided valuable data on the true in-field performance of various building mechanical systems and LAMELs.

  6. Impact of the High Flux Isotope Reactor HEU to LEU Fuel Conversion on Cold Source Nuclear Heat Generation Rates

    Energy Technology Data Exchange (ETDEWEB)

    Chandler, David [ORNL

    2014-03-01

    Under the sponsorship of the US Department of Energy National Nuclear Security Administration, staff members at the Oak Ridge National Laboratory have been conducting studies to determine whether the High Flux Isotope Reactor (HFIR) can be converted from high enriched uranium (HEU) fuel to low enriched uranium (LEU) fuel. As part of these ongoing studies, an assessment of the impact that the HEU to LEU fuel conversion has on the nuclear heat generation rates in regions of the HFIR cold source system and its moderator vessel was performed and is documented in this report. Silicon production rates in the cold source aluminum regions and few-group neutron fluxes in the cold source moderator were also estimated. Neutronics calculations were performed with the Monte Carlo N-Particle code to determine the nuclear heat generation rates in regions of the HFIR cold source and its vessel for the HEU core operating at a full reactor power (FP) of 85 MW(t) and the reference LEU core operating at an FP of 100 MW(t). Calculations were performed with beginning-of-cycle (BOC) and end-of-cycle (EOC) conditions to bound typical irradiation conditions. Average specific BOC heat generation rates of 12.76 and 12.92 W/g, respectively, were calculated for the hemispherical region of the cold source liquid hydrogen (LH2) for the HEU and LEU cores, and EOC heat generation rates of 13.25 and 12.86 W/g, respectively, were calculated for the HEU and LEU cores. Thus, the greatest heat generation rates were calculated for the EOC HEU core, and it is concluded that the conversion from HEU to LEU fuel and the resulting increase of FP from 85 MW to 100 MW will not impact the ability of the heat removal equipment to remove the heat deposited in the cold source system. Silicon production rates in the cold source aluminum regions are estimated to be about 12.0% greater at BOC and 2.7% greater at EOC for the LEU core in comparison to the HEU core. Silicon is aluminum s major transmutation product and

  7. Coated Particles Fuel Compact-General Purpose Heat Source for Advanced Radioisotope Power Systems

    Science.gov (United States)

    El-Genk, Mohamed S.; Tournier, Jean-Michel

    2003-01-01

    Coated Particles Fuel Compacts (CPFC) have recently been shown to offer performance advantage for use in Radioisotope Heater Units (RHUs) and design flexibility for integrating at high thermal efficiency with Stirling Engine converters, currently being considered for 100 We. Advanced Radioisotope Power Systems (ARPS). The particles in the compact consist of 238PuO2 fuel kernels with 5-μm thick PyC inner coating and a strong ZrC outer coating, whose thickness depends on the maximum fuel temperature during reentry, the fuel kernel diameter, and the fraction of helium gas released from the kernels and fully contained by the ZrC coating. In addition to containing the helium generated by radioactive decay of 238Pu for up to 10 years before launch and 10-15 years mission lifetime, the kernels are intentionally sized (>= 300 μm in diameter) to prevent any adverse radiological effects on reentry. This paper investigates the advantage of replacing the four iridium-clad 238PuO2 fuel pellets, the two floating graphite membranes, and the two graphite impact shells in current State-Of-The-Art (SOA) General Purpose Heat Source (GPHS) with CPFC. The total mass, thermal power, and specific power of the CPFC-GPHS are calculated as functions of the helium release fraction from the fuel kernels and maximum fuel temperature during reentry from 1500 K to 2400 K. For the same total mass and volume as SOA GPHS, the generated thermal power by single-size particles CPFC-GPHS is 260 W at Beginning-Of-Mission (BOM), versus 231 W for the GPHS. For an additional 10% increase in total mass, the CPFC-GPHS could generate 340 W BOM; 48% higher than SOA GPHS. The corresponding specific thermal power is 214 W/kg, versus 160 W/kg for SOA GPHS; a 34% increase. Therefore, for the same thermal power, the CPFC-GPHS is lighter than SOA GPHS, while it uses the same amount of 238PuO2 fuel and same aeroshell. For the same helium release fraction and fuel temperature, binary-size particles CPFC-GPHS could

  8. {beta}-decay data requirements for reactor decay heat calculations: study of the possible source of the gamma-ray discrepancy in reactor heat summation calculations

    Energy Technology Data Exchange (ETDEWEB)

    Algora, A.; Tain, J.L.; Perez-Cerdan, A.B.; Rubio, B.; Agramunt, J.; Caballero, L.; Nacher, E.; Jordan, D.; Molina, F. [Valencia Univ., IFIC (Spain); Algora, A.; Krasznahorkay, A.; Hunyadi, M.D.; Gulyas, J.; Vitez, A.; Csatlos, M.; Csige, L. [Institute of Nuclear Research, Debrecen (Hungary); Aysto, J.; Penttila, H.; Rinta-Antila, S.; Moore, I.; Eronen, T.; Jokinen, A.; Nieminen, A.; Hakala, J.; Karvonen, P.; Kankainen, A.; Hager, U.; Sonoda, T.; Saastamoinen, A.; Rissanen, J.; Kessler, T.; Weber, C.; Ronkainen, J.; Rahaman, S.; Elomaa, V. [Jyvaskyla Univ. (Finland); Burkard, K.; Huller, W. [GSI, Darmstadt (Germany); Batist, L. [PNPI, Gatchina (Russian Federation); Gelletly, W. [Surrey Univ., Guildford (United Kingdom); Yoshida, T. [Mushashi Institute of Technology (Japan); Nichols, A.L. [IAEA Nuclear Data Section, Vienna (Austria); Sonzogni, A. [National Nuclear Data Center, Brookhaven National Laboratory, Upton, NY (United States); Perajarvi, K. [STUK, Helsinki (Finland)

    2008-07-01

    The decay heat of fission products plays an important role in predictions of the heat up of nuclear fuel in reactors. The released energy is calculated as the summation of the activities of all fission products P(t) equals {sigma}(E{sub i}*{lambda}{sub i}*N{sub i}(t)), where E{sub i} is the decay energy of nuclide i (gamma and beta component), {lambda}{sub i} is the decay constant of nuclide i and N{sub i}(t) is the number of nuclide i at cooling time t. Even though the reproduction of the measured decay heat has improved in recent years, there is still a long standing discrepancy in the t about 1000 s cooling time for some fuels. A possible explanation to this improper description has been found in the work of Yoshida et al., where it has been shown that the incomplete knowledge of the {beta}-decay of some T{sub c} isotopes can be the source of the systematic discrepancy. We have recently measured the {beta}-decay process of some Tc isotopes using a total absorption spectrometer at the IGISOL facility in Jyvaskyla (Finland). The results of the measurements as well as the their consequences on summation calculations are discussed. (authors)

  9. Optimal Operation of the Integrated Electrical and Heating Systems to Accommodate the Intermittent Renewable Sources

    DEFF Research Database (Denmark)

    Li, Jinghua; Fang, Jiakun; Zeng, Qing

    2016-01-01

    The integration of electrical and heating systems has great potential to enhance the flexibility of power systems to accommodate more renewable power such as the wind and solar. This study was to investigate an optimal way to integrate the energy of both systems in urban areas. The amount of energy...... conversion between the electrical system and heating system was optimally decided so that the demand within both systems could be met at the least operational cost. Besides, the best node to join with the electrical system and heating system was chosen by consideration of the energy transmission loss....... The mathematic formulation of the optimization problem was detailed as a large-scale non-linear program (LSNLP) in this paper. A decomposition-coordination algorithm was proposed to solve this LSNLP. At last, a 6-bus electrical power system with 31-node heating transmission system was studied to demonstrate...

  10. Energy Efficiency Modelling of Residential Air Source Heat Pump Water Heater

    Directory of Open Access Journals (Sweden)

    Cong Toan Tran

    2016-03-01

    Full Text Available The heat pump water heater is one of the most energy efficient technologies for heating water for household use. The present work proposes a simplified model of coefficient of performance and examines its predictive capability. The model is based on polynomial functions where the variables are temperatures and the coefficients are derived from the Australian standard test data, using regression technics. The model enables to estimate the coefficient of performance of the same heat pump water heater under other test standards (i.e. US, Japanese, European and Korean standards. The resulting estimations over a heat-up phase and a full test cycle including a draw off pattern are in close agreement with the measured data. Thus the model allows manufacturers to avoid the need to carry out physical tests for some standards and to reduce product cost. The limitations of the methodology proposed are also discussed.

  11. INTERANNUAL VARIATIONS OF ATMOSPHERIC HEAT SOURCES AND MOISTURE SINKS OVER THE EQUATORIAL PACIFIC AND THEIR RELATIONS TO THE SST ANOMALIES

    Institute of Scientific and Technical Information of China (English)

    蓝光东; 温之平; 贺海晏

    2004-01-01

    The interannual variations of atmospheric heat sources and moisture sinks over the Equatorial Pacific and their relations with the SST anomalies are studied using ECMWF reanalysis data from 1979 to 1993. It is found by singular value decomposition (SVD) analysis that the region in the tropical Pacific with high positive correlation between the vertically integrated heat source anomaly and the SST anomaly, and between the vertically integrated moisture sink anomaly and the SST anomaly, is mainly located in a long and narrow belt to the east of 170 (E between 5 (S and 5 (N. The analysis of the vertical structure of atmospheric heat sources and moisture sinks shows that the interannual variations of Q1, Q2 and SST in the equatorial central and eastern Pacific are strongly and positively correlated in the whole troposphere except the bottom (962.5 hPa) and the top (85 hPa) layers. However, in the western Pacific, the interannual variations of Q1 below 850 hPa is negatively related to the SST. The correlation coefficient at the level 962.5 hPa reaches even -0.59. In other layers the positive correlation between the interannual variations of Q1, Q2 and the SST are weak in the western Pacific.

  12. Thermal balance in term and preterm newborn infants nursed in an incubator equipped with a radiant heat source.

    Science.gov (United States)

    Sjörs, G; Hammarlund, K; Sedin, G

    1997-04-01

    A radiant hood warmer, a device that heats the incubator roof independently of the incubator's main heat source, was used to study the thermal balance of 11 full term and 13 preterm (gestational age 25-34 weeks) infants exposed to an isolated elevation of incubator roof temperature at stable ambient air temperature and humidity. After initial measurements without active heating of the incubator roof, the hood warmer was set to 33 degrees C, 36 degrees C and finally (preterm infants only) to 39 degrees C. At least 18 min of measurements with the infant asleep were made at each hood warmer setting. In the term infants an increase in roof temperature from 30.5 degrees C to 35.6 degrees C resulted in an increase in skin temperature from 35.4 to 35.9 degrees C, and a decrease in radiative heat loss from 32.8 to 20.7 W/m2 exposed skin. In the preterm infants an increase in roof temperature from 31.0 to 38.4 degrees C led to an increase in skin temperature from 35.7 to 36.3 degrees C and a decrease in radiative heat loss from 34.1 to 13.0 W/m2 exposed skin. The increased inner roof surface temperature did not affect evaporative or convective heat loss, skin blood flow, respiratory water loss, oxygen consumption or transepidermal water loss in either group. Thus, at stable ambient air temperature and humidity, the increase in incubator roof temperature resulted in an increase in skin temperature and a decrease in radiative heat loss in both term and preterm infants.

  13. Nanofluids and a method of making nanofluids for ground source heat pumps and other applications

    Science.gov (United States)

    Olson, John Melvin

    2013-11-12

    This invention covers nanofluids. Nanofluids are a combination of particles between 1 and 100 nanometers, a surfactant and the base fluid. The nanoparticles for this invention are either pyrogenic nanoparticles or carbon nanotubes. These nanofluids improve the heat transfer of the base fluids. The base fluid can be ethylene glycol, or propylene glycol, or an aliphatic-hydrocarbon based heat transfer fluid. This invention also includes a method of making nanofluids. No surfactant is used to suspend the pyrogenic nanoparticles in glycols.

  14. The Netherlands. Complex ground source heat drilling for horticultural works; Niederlande. Komplexe Erdwaermebohrung fuer Gartenbaubetriebe

    Energy Technology Data Exchange (ETDEWEB)

    Kilian, Dieter [DrillTec GUT GmbH, Deggendorf (Germany)

    2012-11-01

    For the past six months, the Dutch gardening industry looked to Honselersdijk near Rotterdam with great expectations. There, five market gardening businesses planned to heat their greenhouses with geothermal heat instead of natural gas. After technically complex drilling operations, hot water is now flowing at a rate of up to 50 litres per second; the drilling project remained fascinating to the last for everybody involved.

  15. Evaluation of geothermal energy as a heat source for the oilsands industry in Northern Alberta (Canada)

    Science.gov (United States)

    Majorowicz, J. A.; Unsworth, M.; Gray, A.; Nieuwenhuis, G.; Babadagli, T.; Walsh, N.; Weides, S.; Verveda, R.

    2012-12-01

    The extraction and processing of bitumen from the oilsands of Northern Alberta requires very large amounts of heat that is obtained by burning natural gas. At current levels, the gas used represents 6% of Canada's natural gas production. Geothermal energy could potentially provide this heat, thereby reducing both the financial costs and environmental impact of the oilsands industry. The Helmholtz Alberta Initiative is evaluating this application of geothermal energy through an integrated program of geology, geophysics, reservoir simulation and calculations of the cost benefit. A first stage in this evaluation is refining estimates of subsurface temperature beneath Northern Alberta. This has involved three stages: (1) Corrected industrial thermal data have been used to revise estimates of the upper crustal temperatures beneath the oilsands regions in Alberta. The geothermal gradient map produced using heat flow and thermal conductivity for the entire Phanerozoic column suggests that the overall gradient of the entire column is less than the gradients calculated directly from industry measurements. (2) Paleoclimatic corrections must be applied , since this region has experienced a significant increase in surface temperatures since the end of the last ice age causing a perturbation of shallow heat flow. For this reason, estimates of geothermal gradient based on shallow data are not necessarily characteristic of the whole sedimentary column and can lead to errors in temperature prediction at depth. (3) Improved measurements have been made of the thermal conductivity of the crystalline basement rocks (average = 2.9±0.8 W/m K). Thermal conductivity exhibits significant spatial variability and to a large degree controls the temperature conditions in the Precambrian crystalline basement rocks and its heat content at given heat flow-heat generation. When these steps are used to calculate subsurface temperatures, it can be shown that the temperatures required for geothermal

  16. Study on the Adaptability of Lake Water-source Heat Pump in the Heating Engineering%湖水源热泵冬季供暖适应性研究

    Institute of Scientific and Technical Information of China (English)

    梁昌祝; 陈静; 邓博

    2014-01-01

    The adaptability of lake water source heat pump in winter for heating is analyzed from aspects of lake water temperature, energy efficiency of heat pump units, environmental impact of cooling water drainage and energy saving of heat pump systems. The research shows that lake water source heat pump has good energy-saving effect when used for heating, with measured energy efficiency of heat pump units reaching 4.34 ~ 4.81. The relative energy-saving rate of water source heat pump system reaches 5%, 68% and 29.8% compared with air source heat pump, electric boiler and gas boiler respectively.%从湖体水温、热泵机组能效、冷排水对水环境的影响及热泵系统节能性四个方面分析了湖水源热泵在冬季供暖的适应性。研究表明,湖水源热泵供暖技术具有良好的节能效益,实测热泵机组能效达到4.34~4.81,相对传统的风冷热泵、电锅炉、燃气锅炉系统而言,水源热泵系统的节能率分别达到5%、68%和29.8%。

  17. Applicability of STEM-RTG and High-Power SRG Power Systems to the Discovery and Scout Mission Capabilities Expansion (DSMCE) Study of ASRG-Based Missions

    Science.gov (United States)

    Colozza, Anthony J.; Cataldo, Robert L.

    2015-01-01

    This study looks at the applicability of utilizing the Segmented Thermoelectric Modular Radioisotope Thermoelectric Generator (STEM-RTG) or a high-power radioisotope generator to replace the Advanced Stirling Radioisotope Generator (ASRG), which had been identified as the baseline power system for a number of planetary exploration mission studies. Nine different Discovery-Class missions were examined to determine the applicability of either the STEM-RTG or the high-power SRG power systems in replacing the ASRG. The nine missions covered exploration across the solar system and included orbiting spacecraft, landers and rovers. Based on the evaluation a ranking of the applicability of each alternate power system to the proposed missions was made.

  18. Optimization of ground source heat pumps related to soil and groundwater conditions as well as grouting material; Optimierung von Waermepumpen in Bezug auf Boden- und Grundwasserverhaeltnisse sowie Verpressmaterial

    Energy Technology Data Exchange (ETDEWEB)

    Katzenbach, R.; Clauss, F.; Waberseck, T. [Technische Univ. Darmstadt (Germany). Inst. und Versuchsanstalt fuer Geotechnik; Sass, J. [Technische Univ. Darmstadt (Germany). Inst. fuer Angewandte Geowissenschaften, Fachgebiet Ingenieurgeologie

    2006-07-01

    The capacity and the performance of ground source heat pumps and seasonal thermal storage systems with borehole heat exchangers depend on the conditions of the encountered subsoil and the groundwater and furthermore on the thermal properties of the grouting material used for conclusive backfilling of the annular space after installing the heat exchanger pipes in the borehole. Intensive investigations are carried out at the Technische Universitaet Darmstadt with the aim of an economical optimisation of the dimensioning of ground source heat pumps and seasonal thermal storage systems. (orig.)

  19. GPHS-RTGs in support of the Cassini RTG Program. Addendum to the final technical report, May 1--December 31, 1998

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-12-01

    This Addendum to the Cassini GPHS-RTG Program Final Technical Progress Report describes activities performed during the period 1 May 1998 through 31 December 1998, including effort reflecting contract modification M058. These activities include Earth Gravity Assist (EGA) reentry and related analyses which are detailed in Part A, and effort related to the installation of CAGO equipment within Lockheed Martin`s Building 100 facility in Valley Forge, PA, which is detailed in Part B.

  20. GPHS-RTGs in support of the Cassini RTG Program. Addendum to the final technical report, May 1--December 31, 1998

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-12-01

    This Addendum to the Cassini GPHS-RTG Program Final Technical Progress Report describes activities performed during the period 1 May 1998 through 31 December 1998, including effort reflecting contract modification M058. These activities include Earth Gravity Assist (EGA) reentry and related analyses which are detailed in Part A, and effort related to the installation of CAGO equipment within Lockheed Martin`s Building 100 facility in Valley Forge, PA, which is detailed in Part B.