WorldWideScience

Sample records for water heating system

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

    Directory of Open Access Journals (Sweden)

    Zhongchao Zhao

    2018-05-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Stene, Joern

    2004-02-01

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

  3. Performance Analysis of Photovoltaic Water Heating System

    Directory of Open Access Journals (Sweden)

    Tomas Matuska

    2017-01-01

    Full Text Available Performance of solar photovoltaic water heating systems with direct coupling of PV array to DC resistive heating elements has been studied and compared with solar photothermal systems. An analysis of optimum fixed load resistance for different climate conditions has been performed for simple PV heating systems. The optimum value of the fixed load resistance depends on the climate, especially on annual solar irradiation level. Use of maximum power point tracking compared to fixed optimized load resistance increases the annual yield by 20 to 35%. While total annual efficiency of the PV water heating systems in Europe ranges from 10% for PV systems without MPP tracking up to 15% for system with advanced MPP trackers, the efficiency of solar photothermal system for identical hot water load and climate conditions is more than 3 times higher.

  4. 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.

  5. Basics of Solar Heating & Hot Water Systems.

    Science.gov (United States)

    American Inst. of Architects, Washington, DC.

    In presenting the basics of solar heating and hot water systems, this publication is organized from the general to the specific. It begins by presenting functional and operational descriptions of solar heating and domestic hot water systems, outlining the basic concepts and terminology. This is followed by a description of solar energy utilization…

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

    OpenAIRE

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

    2018-01-01

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

  7. Solar Water Heating System for Biodiesel Production

    Directory of Open Access Journals (Sweden)

    Syaifurrahman

    2018-01-01

    Full Text Available Nowadays, electricity become very expensive thing in some remote areas. Energy from solar panels give the solution as renewable energy that is environment friendly. West Borneo is located on the equator where the sun shines for almost 10-15 hours/day. Solar water heating system which is includes storage tank and solar collections becomes a cost-effective way to generate the energy. Solar panel heat water is delivered to water in storage tank. Hot water is used as hot fluid in biodiesel jacked reactor. The purposes of this research are to design Solar Water Heating System for Biodiesel Production and measure the rate of heat-transfer water in storage tank. This test has done for 6 days, every day from 8.30 am until 2.30 pm. Storage tank and collection are made from stainless steel and polystyrene a well-insulated. The results show that the heater can be reach at 50ºC for ±2.5 hours and the maximum temperature is 62ºC where the average of light intensity is 1280 lux.

  8. Solar Water Heating System for Biodiesel Production

    Science.gov (United States)

    Syaifurrahman; Usman, A. Gani; Rinjani, Rakasiwi

    2018-02-01

    Nowadays, electricity become very expensive thing in some remote areas. Energy from solar panels give the solution as renewable energy that is environment friendly. West Borneo is located on the equator where the sun shines for almost 10-15 hours/day. Solar water heating system which is includes storage tank and solar collections becomes a cost-effective way to generate the energy. Solar panel heat water is delivered to water in storage tank. Hot water is used as hot fluid in biodiesel jacked reactor. The purposes of this research are to design Solar Water Heating System for Biodiesel Production and measure the rate of heat-transfer water in storage tank. This test has done for 6 days, every day from 8.30 am until 2.30 pm. Storage tank and collection are made from stainless steel and polystyrene a well-insulated. The results show that the heater can be reach at 50ºC for ±2.5 hours and the maximum temperature is 62ºC where the average of light intensity is 1280 lux.

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

    Directory of Open Access Journals (Sweden)

    Yuguo Wu

    2018-09-01

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

  10. Solar water heating system for a lunar base

    Science.gov (United States)

    Somers, Richard E.; Haynes, R. Daniel

    1992-01-01

    An investigation of the feasibility of using a solar water heater for a lunar base is described. During the investigation, computer codes were developed to model the lunar base configuration, lunar orbit, and heating systems. Numerous collector geometries, orientation variations, and system options were identified and analyzed. The results indicate that the recommended solar water heater could provide 88 percent of the design load and would not require changes in the overall lunar base design. The system would give a 'safe-haven' water heating capability and use only 7 percent to 10 percent as much electricity as an electric heating system. As a result, a fixed position photovoltaic array can be reduced by 21 sq m.

  11. Municipal water-based heat pump heating and/or cooling systems: Findings and recommendations. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Bloomquist, R.G. [Washington, State Univ., Pullman, WA (United States); Wegman, S. [South Dakota Utilities Commission (United States)

    1998-04-01

    The purpose of the present work was to determine if existing heat pump systems based on municipal water systems meet existing water quality standards, to analyze water that has passed through a heat pump or heat exchanger to determine if corrosion products can be detected, to determine residual chlorine levels in municipal waters on the inlet as well as the outlet side of such installations, to analyses for bacterial contaminants and/or regrowth due to the presence of a heat pump or heat exchanger, to develop and suggest criteria for system design and construction, to provide recommendations and specifications for material and fluid selection, and to develop model rules and regulations for the installation, operation, and monitoring of new and existing systems. In addition, the Washington State University (WSU) has evaluated availability of computer models that would allow for water system mapping, water quality modeling and system operation.

  12. The Utilisation of Solar System in Combined Heating System of Water

    Directory of Open Access Journals (Sweden)

    Ján Jobbágy

    2017-01-01

    Full Text Available The paper assessed the topicality and returns of solar system utilization to heating of water. Practical measurements were conducted after reconstruction of the family house. (in Nesvady, Slovak republic, on which the solar system were assembled. The system consists of the gas heater, solar panels, distributions and circulation pump. The solar system was assembled due to decreasing of operation costs and connected with conventional already used gas heating system by boiler Quantum (V = 115 L. The conventional system was used for 21 days to gather basic values for evaluation. At this point it was observed that 11.93 m3 of gas is needed to heat up 1 m3 of water. Used water in this case was heated from initial 16.14 °C to 52.04 °C of output temperature. Stand by regime of boiler was characterized by 0.012 m3.h-1 consumption of gas. The rest of the measurements represent the annual (from 03/2013 to 02/2014 operation process of boiler Tatramat VTS 200L (trivalent with 200 litres of volume (as a part of Thermosolar solar system. The solar collectors TS 300 are also part of the solar system. An input and output temperatures of heating water we observed along with water and gas consumption, intensity of solar radiation and actual weather conditions. The amount of heat produced by solar system was then calculated. Total investment on solar system were 2,187.7 € (1,475.7 € with subsidy. Therefore, return on investment for the construction of the solar system was set at 23 years even with subsidy.

  13. An analytical method for defining the pump`s power optimum of a water-to-water heat pump heating system using COP

    Directory of Open Access Journals (Sweden)

    Nyers Jozsef

    2017-01-01

    Full Text Available This paper analyzes the energy efficiency of the heat pump and the complete heat pump heating system. Essentially, the maximum of the coefficient of performance of the heat pump and the heat pump heating system are investigated and determined by applying a new analytical optimization procedure. The analyzed physical system consists of the water-to-water heat pump, circulation and well pump. In the analytical optimization procedure the "first derivative equal to zero" mathematical method is applied. The objective function is the coefficient of performance of the heat pump, and the heat pump heating system. By using the analytical optimization procedure and the objective function, as the result, the local and the total energy optimum conditions with respect to the mass flow rate of hot and cold water i. e. the power of circulation or well pump are defined.

  14. Retrofitting Combined Space and Water Heating Systems: Laboratory Tests

    Energy Technology Data Exchange (ETDEWEB)

    Schoenbauer, B.; Bohac, D.; Huelman, P.; Olson, R.; Hewitt, M.

    2012-10-01

    Better insulated and tighter homes can often use a single heating plant for both space and domestic water heating. These systems, called dual integrated appliances (DIA) or combination systems, can operate at high efficiency and eliminate combustion safety issues associated by using a condensing, sealed combustion heating plant. Funds were received to install 400 DIAs in Minnesota low-income homes. The NorthernSTAR DIA laboratory was created to identify proper system components, designs, operating parameters, and installation procedures to assure high efficiency of field installed systems. Tests verified that heating loads up to 57,000 Btu/hr can be achieved with acceptable return water temperatures and supply air temperatures.

  15. Retrofitting Combined Space and Water Heating Systems. Laboratory Tests

    Energy Technology Data Exchange (ETDEWEB)

    Schoenbauer, B. [NorthernStar Building America Partnership, St. Paul, MN (United States); Bohac, D. [NorthernStar Building America Partnership, St. Paul, MN (United States); Huelman, P. [NorthernStar Building America Partnership, St. Paul, MN (United States); Olsen, R. [NorthernStar Building America Partnership, St. Paul, MN (United States); Hewett, M. [NorthernStar Building America Partnership, St. Paul, MN (United States)

    2012-10-01

    Better insulated and tighter homes can often use a single heating plant for both space and domestic water heating. These systems, called dual integrated appliances (DIA) or combination systems, can operate at high efficiency and eliminate combustion safety issues associated by using a condensing, sealed combustion heating plant. Funds were received to install 400 DIAs in Minnesota low-income homes. The NorthernSTAR DIA laboratory was created to identify proper system components, designs, operating parameters, and installation procedures to assure high efficiency of field installed systems. Tests verified that heating loads up to 57,000 Btu/hr can be achieved with acceptable return water temperatures and supply air temperatures.

  16. Demand side management in South Africa at industrial residence water heating systems using in line water heating methodology

    International Nuclear Information System (INIS)

    Rankin, R.; Rousseau, P.G.

    2008-01-01

    The South African electrical utility, ESKOM, currently focuses its demand side management (DSM) initiatives on controlling electrical load between 18:00 and 20:00 each day, which is the utility's peak demand period. Funding is provided to energy service companies (ESCo's) to implement projects that can achieve load shifting out of this period. This paper describes how an improved in line water heating concept developed in previous studies was implemented into several real life industrial sanitary water heating systems to obtain the DSM load shift required by ESKOM. Measurements from a selection of these plants are provided to illustrate the significant load reductions that are being achieved during 18:00-20:00. The measured results also show that the peak load reduction is achieved without adversely affecting the availability of sufficient hot water to the persons using the showering and washing facilities served by the water heating system. A very good correlation also exists between these measured results and simulations that were done beforehand to predict the DSM potential of the project. The in line water heater concept provides an improved solution for DSM at sanitary water heating systems due to the stratified manner in which hot water is supplied to the tanks. This provides an improved hot water supply to users when compared to conventional in tank heating systems, even with load shifting being done. It also improves the storage efficiency of a plant, thereby allowing the available storage capacity of a plant to be utilized to its full extent for load shifting purposes

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

    International Nuclear Information System (INIS)

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

    2003-01-01

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

  18. Prototype solar heating and hot water system

    Science.gov (United States)

    1977-01-01

    Progress is reported in the development of a solar heating and hot water system which uses a pyramidal optics solar concentrator for heating, and consists of the following subsystems: collector, control, transport, and site data acquisition. Improvements made in the components and subsystems are discussed.

  19. Solar system for domestic hot water and space heating

    Energy Technology Data Exchange (ETDEWEB)

    Weiss, W. [Arbeitsgemeinschaf Erneubare Energie, Gleisdorf (Austria)

    1997-12-31

    The solar thermal markets, different types of solar systems for hot water and space heating, the dimensioning and the components of solar heating systems, the properties of the systems are reviewed in this presentation

  20. Solar system for domestic hot water and space heating

    Energy Technology Data Exchange (ETDEWEB)

    Weiss, W [Arbeitsgemeinschaf Erneubare Energie, Gleisdorf (Austria)

    1998-12-31

    The solar thermal markets, different types of solar systems for hot water and space heating, the dimensioning and the components of solar heating systems, the properties of the systems are reviewed in this presentation

  1. Characterization of a solar photovoltaic/loop-heat-pipe heat pump water heating system

    International Nuclear Information System (INIS)

    Zhang, Xingxing; Zhao, Xudong; Xu, Jihuan; Yu, Xiaotong

    2013-01-01

    Highlights: ► Describing concept and operating principle of the PV/LHP heat pump water heating system. ► Developing a numerical model to evaluate the performance of the system. ► Experimental testing of the prototype system. ► Characterizing the system performance using parallel comparison between the modelling and experimental results. ► Investigating the impact of the operating conditions to the system’s performance. -- Abstract: This paper introduced the concept, potential application and benefits relating to a novel solar photovoltaic/loop-heat-pipe (PV/LHP) heat pump system for hot water generation. On this basis, the paper reported the process and results of characterizing the performance of such a system, which was undertaken through dedicated thermo-fluid and energy balance analyses, computer model development and operation, and experimental verification and modification. The fundamental heat transfer, fluid flow and photovoltaic governing equations were applied to characterize the energy conversion and transfer processes occurring in each part and whole system layout; while the energy balance approach was utilized to enable inter-connection and resolution of the grouped equations. As a result, a dedicated computer model was developed and used to calculate the operational parameters, optimise the geometrical configurations and sizes, and recommend the appropriate operational condition relating to the system. Further, an experimental rig was constructed and utilized to acquire the relevant measurement data that thus enabled the parallel comparison between the simulation and experiment. It is concluded that the testing and modelling results are in good agreement, indicating that the model has the reasonable accuracy in predicting the system’s performance. Under the given experimental conditions, the electrical, thermal and overall efficiency of the PV/LHP module were around 10%, 40% and 50% respectively; whilst the system’s overall performance

  2. Installation package for a solar heating and hot water system

    Science.gov (United States)

    1978-01-01

    Development and installation of two commercial solar heating and hot water systems are reported. The systems consist of the following subsystems: collector, storage, transport, hot water, auxiliary energy and controls. General guidelines are provided which may be utilized in development of detailed installation plans and specifications. In addition, operation, maintenance and repair of a solar heating and hot water system instructions are included.

  3. Life cycle assessment of domestic heat pump hot water systems in Australia

    Directory of Open Access Journals (Sweden)

    Moore Andrew D.

    2017-01-01

    Full Text Available Water heating accounts for 23% of residential energy consumption in Australia, and, as over half is provided by electric water heaters, is a significant source of greenhouse gas emissions. Due to inclusion in rebate schemes heat pump water heating systems are becoming increasingly popular, but do they result in lower greenhouse gas emissions? This study follows on from a previous life cycle assessment study of domestic hot water systems to include heat pump systems. The streamlined life cycle assessment approach used focused on the use phase of the life cycle, which was found in the previous study to be where the majority of global warming potential (GWP impacts occurred. Data was collected from an Australian heat pump manufacturer and was modelled assuming installation within Australian climate zone 3 (AS/NZS 4234:2011. Several scenarios were investigated for the heat pumps including different sources of electricity (grid, photovoltaic solar modules, and batteries and the use of solar thermal panels. It was found that due to their higher efficiency heat pump hot water systems can result in significantly lower GWP than electric storage hot water systems. Further, solar thermal heat pump systems can have lower GWP than solar electric hot water systems that use conventional electric boosting. Additionally, the contributions of HFC refrigerants to GWP can be significant so the use of alternative refrigerants is recommended. Heat pumps combined with PV and battery technology can achieve the lowest GWP of all domestic hot water systems.

  4. Prototype solar heating and cooling systems including potable hot water

    Science.gov (United States)

    1978-01-01

    Progress is reviewed in the development, delivery, and support of two prototype solar heating and cooling systems including potable hot water. The system consisted of the following subsystems: collector, auxiliary heating, potable hot water, storage, control, transport, and government-furnished site data acquisition.

  5. Solar-assisted heat pump – A sustainable system for low-temperature water heating applications

    International Nuclear Information System (INIS)

    Chaturvedi, S.K.; Gagrani, V.D.; Abdel-Salam, T.M.

    2014-01-01

    Highlights: • DX-SAHP water heaters systems are economical as well as energy conserving. • The economic analysis is performed using the life cycle cost (LCC) analysis. • LCC can be optimized with respect to the collector area at a specific temperature. • For high load temperature range a two stage heat pump system is more appropriate. - Abstract: Direct expansion solar assisted heat pump systems (DX-SAHP) have been widely used in many applications including water heating. In the DX-SAHP systems the solar collector and the heat pump evaporator are integrated into a single unit in order to transfer the solar energy to the refrigerant. The present work is aimed at studying the use of the DX-SAHP for low temperature water heating applications. The novel aspect of this paper involves a detailed long-term thermo-economic analysis of the energy conservation potential and economic viability of these systems. The thermal performance is simulated using a computer program that incorporates location dependent radiation, collector, economic, heat pump and load data. The economic analysis is performed using the life cycle cost (LCC) method. Results indicate that the DX-SAHP water heaters systems when compared to the conventional electrical water heaters are both economical as well as energy conserving. The analysis also reveals that the minimum value of the system life cycle cost is achieved at optimal values of the solar collector area as well as the compressor displacement capacity. Since the cost of SAHP system presents a barrier to mass scale commercialization, the results of the present study indicating that the SAHP life cycle cost can be minimized by optimizing the collector area would certainly be helpful in lowering, if not eliminating, the economic barrier to these systems. Also, at load temperatures higher than 70 °C, the performance of the single stage heat pump degrades to the extent that its cost and efficiency advantages over the electric only system are

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

    International Nuclear Information System (INIS)

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

    1993-01-01

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

  7. Increase of COP for heat transformer in water purification systems. Part II - Without increasing heat source temperature

    International Nuclear Information System (INIS)

    Romero, R.J.; Siqueiros, J.; Huicochea, A.

    2007-01-01

    The integration of a water purification system allows a heat transformer to increase the actual coefficient of performance, by the reduction of the amount of heat supplied by unit of heat. A new defined COP called COP WP is proposed for the present system, which considers the fraction of heat recycled. Simulation with proven software compares the performance of the modeling of an absorption heat transformer for water purification (AHTWP) operating with water/lithium bromide, as working fluid-absorbent pair. Plots of enthalpy-based coefficients of performance (COP ET ) and water purification coefficient of performance (COP WP ) are shown against absorber temperature for several thermodynamic operating conditions. The results showed that the proposed (AHTWP) system is capable of increasing the original value of COP ET up to 1.6 times its original value by recycling energy from a water purification system. The proposed COP WP allows increments for COP values from any experimental data for water purification or for any other distillation system integrated to a heat transformer, regardless of actual COP A value or working fluid-absorbent pair

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

    International Nuclear Information System (INIS)

    Siqueiros, J.; Romero, R.J.

    2007-01-01

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

  9. Influence of ambient temperatures on performance of a CO2 heat pump water heating system

    International Nuclear Information System (INIS)

    Yokoyama, Ryohei; Shimizu, Takeshi; Ito, Koichi; Takemura, Kazuhisa

    2007-01-01

    In residential applications, an air-to-water CO 2 heat pump is used in combination with a domestic hot water storage tank, and the performance of this system is affected significantly not only by instantaneous ambient air and city water temperatures but also by hourly changes of domestic hot water consumption and temperature distribution in the storage tank. In this paper, the performance of a CO 2 heat pump water heating system is analyzed by numerical simulation. A simulation model is created based on thermodynamic equations, and the values of model parameters are estimated based on measured data for existing devices. The calculated performance is compared with the measured one, and the simulation model is validated. The system performance is clarified in consideration of seasonal changes of ambient air and city water temperatures

  10. Nuclear reactor with makeup water assist from residual heat removal system

    Science.gov (United States)

    Corletti, Michael M.; Schulz, Terry L.

    1993-01-01

    A pressurized water nuclear reactor uses its residual heat removal system to make up water in the reactor coolant circuit from an in-containment refueling water supply during staged depressurization leading up to passive emergency cooling by gravity feed from the refueling water storage tank, and flooding of the containment building. When depressurization commences due to inadvertence or a manageable leak, the residual heat removal system is activated manually and prevents flooding of the containment when such action is not necessary. Operation of the passive cooling system is not impaired. A high pressure makeup water storage tank is coupled to the reactor coolant circuit, holding makeup coolant at the operational pressure of the reactor. The staged depressurization system vents the coolant circuit to the containment, thus reducing the supply of makeup coolant. The level of makeup coolant can be sensed to trigger opening of successive depressurization conduits. The residual heat removal pumps move water from the refueling water storage tank into the coolant circuit as the coolant circuit is depressurized, preventing reaching the final depressurization stage unless the makeup coolant level continues to drop. The residual heat removal system can also be coupled in a loop with the refueling water supply tank, for an auxiliary heat removal path.

  11. Nuclear reactor with makeup water assist from residual heat removal system

    International Nuclear Information System (INIS)

    Corletti, M.M.; Schulz, T.L.

    1993-01-01

    A pressurized water nuclear reactor uses its residual heat removal system to make up water in the reactor coolant circuit from an in-containment refueling water supply during staged depressurization leading up to passive emergency cooling by gravity feed from the refueling water storage tank, and flooding of the containment building. When depressurization commences due to inadvertence or a manageable leak, the residual heat removal system is activated manually and prevents flooding of the containment when such action is not necessary. Operation of the passive cooling system is not impaired. A high pressure makeup water storage tank is coupled to the reactor coolant circuit, holding makeup coolant at the operational pressure of the reactor. The staged depressurization system vents the coolant circuit to the containment, thus reducing the supply of makeup coolant. The level of makeup coolant can be sensed to trigger opening of successive depressurization conduits. The residual heat removal pumps move water from the refueling water storage tank into the coolant circuit as the coolant circuit is depressurized, preventing reaching the final depressurization stage unless the makeup coolant level continues to drop. The residual heat removal system can also be coupled in a loop with the refueling water supply tank, for an auxiliary heat removal path. 2 figures

  12. Nuclear reactor with makeup water assist from residual heat removal system

    Science.gov (United States)

    Corletti, M.M.; Schulz, T.L.

    1993-12-07

    A pressurized water nuclear reactor uses its residual heat removal system to make up water in the reactor coolant circuit from an in-containment refueling water supply during staged depressurization leading up to passive emergency cooling by gravity feed from the refueling water storage tank, and flooding of the containment building. When depressurization commences due to inadvertence or a manageable leak, the residual heat removal system is activated manually and prevents flooding of the containment when such action is not necessary. Operation of the passive cooling system is not impaired. A high pressure makeup water storage tank is coupled to the reactor coolant circuit, holding makeup coolant at the operational pressure of the reactor. The staged depressurization system vents the coolant circuit to the containment, thus reducing the supply of makeup coolant. The level of makeup coolant can be sensed to trigger opening of successive depressurization conduits. The residual heat removal pumps move water from the refueling water storage tank into the coolant circuit as the coolant circuit is depressurized, preventing reaching the final depressurization stage unless the makeup coolant level continues to drop. The residual heat removal system can also be coupled in a loop with the refueling water supply tank, for an auxiliary heat removal path. 2 figures.

  13. Solar heating and hot water system installed at Arlington Raquetball Club, Arlington, Virginia

    Science.gov (United States)

    1981-01-01

    A solar space and water heating system is described. The solar energy system consists of 2,520 sq. ft. of flat plate solar collectors and a 4,000 gallon solar storage tank. The transfer medium in the forced closed loop is a nontoxic antifreeze solution (50 percent water, 50 percent propylene glycol). The service hot water system consists of a preheat coil (60 ft. of 1 1/4 in copper tubing) located in the upper third of the solar storage tank and a recirculation loop between the preheat coil and the existing electric water heaters. The space heating system consists of two separate water to air heat exchangers located in the ducts of the existing space heating/cooling systems. The heating water is supplied from the solar storage tank. Extracts from site files, specification references for solar modifications to existing building heating and hot water systems, and installation, operation and maintenance instructions are included.

  14. Preliminary design package for solar heating and hot water system

    Science.gov (United States)

    1976-01-01

    Two prototype solar heating and hot water systems for use in single-family dwellings or commercial buildings were designed. Subsystems included are: collector, storage, transport, hot water, auxiliary energy, and government-furnished site data acquisition. The systems are designed for Yosemite, California, and Pueblo, Colorado. The necessary information to evaluate the preliminary design for these solar heating and hot water systems is presented. Included are a proposed instrumentation plan, a training program, hazard analysis, preliminary design drawings, and other information about the design of the system.

  15. Investigation of a heat storage for a solar heating system for combined space heating and domestic hot water supply for homeowner´s association "Bakken"

    DEFF Research Database (Denmark)

    Vejen, Niels Kristian

    1998-01-01

    A heat storage for a solar heating system for combined space heating and domestic hot water supply was tested in a laboratory test facility.The heat storage consist of a mantle tank with water for the heating system and of a hot water tank, which by means of thermosyphoning is heated by the water...

  16. Water heating solar system using collector with polycarbonate absorber surface

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Luiz Guilherme Meira de; Sodre, Dilton; Cavalcanti, Eduardo Jose Cidade; Souza, Luiz Guilherme Vieira Meira de; Mendes, Jose Ubiragi de Lima [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil)], e-mails: lguilherme@dem.ufrn.br, diltonsodre@ifba.edu.br, ubiragi@ct.ufrn.br

    2010-07-01

    It is presented s solar collector to be used in a heating water for bath system, whose main characteristics are low cost and easy fabrication and assembly processes. The collector absorber surface consists of a polycarbonate plate with an area of 1.5 m{sup 2}. The water inlet and outlet are made of PVC 50mm, and were coupled to a 6mm thick polycarbonate plate using fiberglass resin. A 200 liters thermal reservoir will be used. This reservoir is also alternative. The absorber heating system works under thermo-siphon regimen. Thermal parameters will be evaluated to prove the feasibility of the studied solar heating system to obtain bath water for a four people family. (author)

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

    Institute of Scientific and Technical Information of China (English)

    Nan Lv; Qing Zhang; Zhenqian Chen; Dongsheng Wu

    2017-01-01

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

  18. Preventing damage in heating systems. Corrosion resulting from water in heating systems; Schaeden in Heizungsanlagen vermeiden. Korrosion in Verbindung mit Heizungswasser

    Energy Technology Data Exchange (ETDEWEB)

    Hannemann, M. [Hannemann Wassertechnik Deutschland, Erding (Germany)

    2004-02-01

    Nearly all heating systems today use water as heating fluid. It is therefore important to know about the properties of this heat carrier fluid and about its interactions with heating system materials. This contribution discusses the main characteristics of common types of water and their effects on the heating systems. (orig.) [German] Praktisch in jeder Heizungsanlage wird Wasser als Waermetraeger verwendet. Von daher ist es ratsam, Eigenschaften dieses Waermetraegers und seine Wechselwirkungen mit Heizungswerkstoffen zu kennen. Der nachfolgende Beitrag behandelt die wichtigsten Eigenschaften gebraeuchlicher Waesser und deren Auswirkungen auf die Heizungsanlagen. (orig.)

  19. Comparison of three systems of solar water heating by thermosiphon

    Science.gov (United States)

    Hernández, E.; Guzmán, R. E.

    2016-02-01

    The main purpose of this project was to elaborate a comparison between three water heating systems; using two plane water heating solar collector and another using a vacuum tube heater, all of them are on top of the cafeteria's roof on building of the “Universidad Pontificia Bolivariana” in Bucaramanga, Colombia. Through testing was determined each type of water heating systems' performance, where the Stainless Steel tube collector reached a maximum efficiency of 71.58%, the Copper Tubing Collector a maximum value of 76.31% and for the Vacuum Tube Heater Collector a maximum efficiency of 72.33%. The collector with copper coil was the system more efficient. So, taking into account the Performance and Temperature Curves, along with the weather conditions at the time of the testing we determined that the most efficient Solar Heating System is the one using a Vacuum Tube Heater Collector. Reaching a maximum efficiency of 72.33% and a maximum temperature of 62.6°C.

  20. Optimization of Solar Water Heating System under Time and Spatial Partition Heating in Rural Dwellings

    Directory of Open Access Journals (Sweden)

    Yanfeng Liu

    2017-10-01

    Full Text Available This paper proposes the application of time and spatial partition heating to a solar water heating system. The heating effect and system performance were analyzed under the continuous and whole space heating and time and spatial partition heating using TRNSYS. The results were validated by comparing with the test results of the demonstration building. Compared to continuous and whole space heating, the use of time and spatial partition heating increases the solar fraction by 16.5%, reduces the auxiliary heating by 7390 MJ, and reduces the annual operation cost by 2010 RMB. Under time and spatial partition heating, optimization analyses were conducted for the two system capacity parameters of the solar collector area and tank volume and the one operation parameter of auxiliary heater setting outlet temperature. The results showed that a reasonable choice of the solar collector area can reduce the dynamic annual cost, the increased tank volume is advantageous to heat storage, and the auxiliary heater setting outlet temperature have greater influence on the indoor heating effect. The advanced opening of solar water heating system and the normal opening of passive air vents are recommended. Based on the comparison of the two modes, the time and spatial partition heating technology is a better choice for rural dwellings.

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

    Directory of Open Access Journals (Sweden)

    Piljae Im

    2018-01-01

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

  2. Optimum systems design with random input and output applied to solar water heating

    Science.gov (United States)

    Abdel-Malek, L. L.

    1980-03-01

    Solar water heating systems are evaluated. Models were developed to estimate the percentage of energy supplied from the Sun to a household. Since solar water heating systems have random input and output queueing theory, birth and death processes were the major tools in developing the models of evaluation. Microeconomics methods help in determining the optimum size of the solar water heating system design parameters, i.e., the water tank volume and the collector area.

  3. Optimization and Thermoeconomics Research of a Large Reclaimed Water Source Heat Pump System

    Directory of Open Access Journals (Sweden)

    Zi-ping Zhang

    2013-01-01

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

  4. A LCC model of renewal energy : the cases of water heating system in Taiwan

    Energy Technology Data Exchange (ETDEWEB)

    Hsu, K.J. [Leader Univ., Tainan City, Taiwan (China). Dept. of Construction Technology; Huang, J.S. [National Taiwan Univ., Taipei, Taiwan (China). Dept. of Bioenvironmental Systems Engineering

    2007-07-01

    One of the most important renewable energy strategies being promoted by the Bureau of Energy, Ministry of Economic Affairs in Taiwan is the use of solar energy water heating systems. This paper presented the results of a study that examined whether these systems were a feasible alternative without governmental subsidies. Economic methods of investment analysis, such as net benefit analysis, the saving-to-investment ratio, the adjusted internal rate of return, the life cycle cost (LCC) analysis, and sensitivity analysis can be used to evaluate buildings and building systems. Comparing different kinds of energy consumption alternatives, the LCC method is particularly suitable for determining whether the higher initial cost of the systems is economically justified by reductions in future costs. This study used the LCC method to evaluate renewable energy alternatives in Taiwan using water heating systems in the National Taiwan University (NTU) Smart Home as illustrative examples. Three kinds of water heating systems are used in the NTU Smart Home, including the evacuated tubular collectors, heat pump water heating system and power-saving water heating system. This study assessed LCC using gas geyser heating as the contrast group. Sensitivity analysis was used to verify the major factors, and show how it influences life cycle costing. It was concluded that compared with the gas geyser water heating system, the power-saving water heating system was the inefficient scheme. 7 refs., 1 tab., 2 figs.

  5. Theory of energy level and its application in water-loop heat pump system

    International Nuclear Information System (INIS)

    Yu, Qi Dong

    2017-01-01

    Highlights: • Novel theory of saving energy and its application in water loop heat pump. • Reverse energy caused by units to water loop and its solution. • New method for determining the energy-saving range of water loop heat pump. • Capacity model of auxiliary heat source and its size for all building types. • Advice for reducing total energy consumption of water loop heat pump. - Abstract: It is a difficult problem to how to determine the reverse energy caused by units to water loop when a water-loop heat pump (WLHP) is in cooling and heating simultaneous mode, which not only has a great impact on energy-saving rate but also decides the use of auxiliary heat source in winter. This paper presents a theory of energy level to improve the research on WLHP system by using the relationship among building, circulating water and units. In this theory, the circulating water replaces building load as a new method to convert the reverse energy into energy change of circulating water and the equation of energy level also is built to determine the energy-saving range of WLHP system and report the capacity model of auxiliary heat source for all building types. An office building with different auxiliary powers is tested to analyze system operation characteristic and the effect of auxiliary heat source on unit and system and the results validate previous conclusions and suggest that an energy balance should be considered between units and auxiliary power to improve overall operation.

  6. Measure Guideline. Combination Forced-Air Space and Tankless Domestic Hot Water Heating Systems

    Energy Technology Data Exchange (ETDEWEB)

    Rudd, Armin [Building Science Corporation Industry Team (BSC), Somerville, MA (United States)

    2012-08-01

    This document describes design and application guidance for combination space and tankless domestic hot water heating systems (combination systems) used in residential buildings, based on field evaluation, testing, and industry meetings conducted by Building Science Corporation. As residential building enclosure improvements continue to drive heating loads down, using the same water heating equipment for both space heating and domestic water heating becomes attractive from an initial cost and space-saving perspective. This topic is applicable to single- and multi-family residential buildings, both new and retrofitted.

  7. Minimizing temperature instability of heat recovery hot water system utilizing optimized thermal energy storage

    Science.gov (United States)

    Suamir, I. N.; Sukadana, I. B. P.; Arsana, M. E.

    2018-01-01

    One energy-saving technology that starts gaining attractive for hotel industry application in Indonesia is the utilization of waste heat of a central air conditioning system to heat water for domestic hot water supply system. Implementing the technology for such application at a hotel was found that hot water capacity generated from the heat recovery system could satisfy domestic hot water demand of the hotel. The gas boilers installed in order to back up the system have never been used. The hot water supply, however, was found to be instable with hot water supply temperature fluctuated ranging from 45 °C to 62 °C. The temperature fluctuations reaches 17 °C, which is considered instable and can reduce hot water usage comfort level. This research is aimed to optimize the thermal energy storage in order to minimize the temperature instability of heat recovery hot water supply system. The research is a case study approach based on cooling and hot water demands of a hotel in Jakarta-Indonesia that has applied water cooled chillers with heat recovery systems. The hotel operation with 329 guest rooms and 8 function rooms showed that hot water production in the heat recovery system completed with 5 m3 thermal energy storage (TES) could not hold the hot water supply temperature constantly. The variations of the cooling demand and hot water demands day by day were identified. It was found that there was significant mismatched of available time (hours) between cooling demand which is directly correlated to the hot water production from the heat recovery system and hot water usage. The available TES system could not store heat rejected from the condenser of the chiller during cooling demand peak time between 14.00 and 18.00 hours. The extra heat from the heat recovery system consequently increases the temperature of hot water up to 62 °C. It is about 12 K above 50 °C the requirement hot water temperature of the hotel. In contrast, the TES could not deliver proper

  8. Solar heating and hot water system installed at Cherry Hill, New Jersey

    Science.gov (United States)

    1979-01-01

    The solar heating and hot water system installed in existing buildings at the Cherry Hill Inn in Cherry Hill, New Jersey is described in detail. The system is expected to furnish 31.5% of the overall heating load and 29.8% of the hot water load. The collectors are liquid evacuated tube type. The storage system is an above ground insulated steel water tank with a capacity of 7,500 gallons.

  9. Theoretical investigation of the performance of a novel loop heat pipe solar water heating system for use in Beijing, China

    International Nuclear Information System (INIS)

    Zhao Xudong; Wang Zhangyuan; Tang Qi

    2010-01-01

    A novel loop heat pipe (LHP) solar water heating system for typical apartment buildings in Beijing was designed to enable effective collection of solar heat, distance transport, and efficient conversion of solar heat into hot water. Taking consideration of the heat balances occurring in various parts of the loop, such as the solar absorber, heat pipe loop, heat exchanger and storage tank, a computer model was developed to investigate the thermal performance of the system. With the specified system structure, the efficiency of the solar system was found to be a function of its operational characteristics - working temperature of the loop heat pipe, water flow rate across the heat exchanger, and external parameters, including ambient temperature, temperature of water across the exchanger and solar radiation. The relationship between the efficiency of the system and these parameters was established, analysed and discussed in detail. The study suggested that the loop heat pipe should be operated at around 72 deg. C and the water across the heat exchanger should be maintained at 5.1 l/min. Any variation in system structure, i.e., glazing cover and height difference between the absorber and heat exchanger, would lead to different system performance. The glazing covers could be made using either borosilicate or polycarbonate, but borosilicate is to be preferred as it performs better and achieves higher efficiency at higher temperature operation. The height difference between the absorber and heat exchanger in the design was 1.9 m which is an adequate distance causing no constraint to heat pipe heat transfer. These simulation results were validated with the primary testing results.

  10. Nuclear reactor with makeup water assist from residual heat removal system

    International Nuclear Information System (INIS)

    Schulz, T.L.; Corletti, M.M.

    1994-01-01

    A pressurized water nuclear reactor uses its residual heat removal system to make up water in the reactor coolant circuit by pumping water from an in-containment refueling water storage tank during staged depressurization of the coolant circuit, the final stage including passive emergency cooling by gravity feed from the refueling water storage tank to the coolant circuit and to flood the containment building. When depressurization commences due to inadvertence or a manageable leak, the residual heat removal system is activated manually and avoids the final stage of depressurization with its flooding of the containment when such action is not necessary, but does not prevent the final stage when it is necessary. A high pressure makeup water storage tank coupled to the reactor coolant circuit holds makeup coolant at the operational pressure of the reactor. The staged depressurization system vents the coolant circuit to the containment, thus reducing the supply of makeup coolant. The level of makeup coolant can be sensed to trigger opening of successive depressurization conduits. The residual heat removal system can also be coupled in a loop with the refueling water supply tanks for cooling the tank. (Author)

  11. 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.

  12. Installation package for a sunspot cascade solar water heating system

    Science.gov (United States)

    1980-01-01

    Solar water heating systems installed at Tempe, Arizona and San Diego, California are described. The systems consist of the following: collector, collector-tank water loop, solar tank, conventional tank, and controls. General guidelines which may be utilized in development of detailed installation plans and specifications are provided along with instruction on operation, maintenance, and installation of solar hot water systems.

  13. Power generation and heating performances of integrated system of ammonia–water Kalina–Rankine cycle

    International Nuclear Information System (INIS)

    Zhang, Zhi; Guo, Zhanwei; Chen, Yaping; Wu, Jiafeng; Hua, Junye

    2015-01-01

    Highlights: • Integrated system of ammonia–water Kalina–Rankine cycle (AWKRC) is investigated. • Ammonia–water Rankine cycle is operated for cogenerating room heating-water in winter. • Kalina cycle with higher efficiency is operated for power generation in other seasons. • Power recovery efficiency accounts thermal efficiency and waste heat absorbing ratio. • Heating water with 70 °C and capacity of 55% total reclaimed heat load is cogenerated. - Abstract: An integrated system of ammonia–water Kalina–Rankine cycle (AWKRC) for power generation and heating is introduced. The Kalina cycle has large temperature difference during evaporation and small one during condensation therefore with high thermal efficiency for power generation, while the ammonia–water Rankine cycle has large temperature difference during condensation as well as evaporation, thus it can be adopted to generate heating-water as a by-product in winter. The integrated system is based on the Kalina cycle and converted to the Rankine cycle with a set of valves. The performances of the AWKRC system in different seasons with corresponding cycle loops were studied and analyzed. When the temperatures of waste heat and cooling water are 300 °C and 25 °C respectively, the thermal efficiency and power recovery efficiency of Kalina cycle are 20.9% and 17.4% respectively in the non-heating seasons, while these efficiencies of the ammonia–water Rankine cycle are 17.1% and 13.1% respectively with additional 55.3% heating recovery ratio or with comprehensive efficiency 23.7% higher than that of the Kalina cycle in heating season

  14. Solar heating and hot water system installed at Saint Louis, Missouri

    Science.gov (United States)

    1980-01-01

    The solar heating and hot water system installed at the William Tao & Associates, Inc., office building in St. Louis, Missouri is described, including maintenance and construction problems, final drawings, system requirements, and manufacturer's component data. The solar system was designed to provide 50 percent of the hot water requirements and 45 percent of the space heating needs for a 900 sq ft office space and drafting room. The solar facility has 252 sq ft of glass tube concentrator collectors and a 1000 gallon steel storage tank buried below a concrete slab floor. Freeze protection is provided by a propylene glycol/water mixture in the collector loop. The collectors are roof mounted on a variable tilt array which is adjusted seasonally and is connected to the solar thermal storage tank by a tube-in-shell heat exchanger. Incoming city water is preheated through the solar energy thermal storage tank.

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

    Directory of Open Access Journals (Sweden)

    Denysova Alla

    2015-08-01

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

  16. A study on the formation of fouling in a heat exchanging system for Han-river water as cooling water

    International Nuclear Information System (INIS)

    Sung, Sun Kyung; Suh, Sang Ho; Rho, Hyung Woon; Cho, Young Il

    2003-01-01

    Scale is formed when hard water is heated or cooled in heat transfer equipments such as heat exchangers, condensers, evaporators, cooling towers, boilers, and pipe walls. When scale deposits in a heat exchanger surface, it is traditionally called fouling. The objective of the present study is to investigate the formation of fouling in a heat exchanging system. A lab-scale heat exchanging system is built-up to observe and measure the formation of fouling experimentally. Water analyses are conducted to obtain the properties of Han river water. In the present study a microscopic observation is conducted to visualize the process of scale formation. Hardness of Han-river water is higher than that of tap water in Seoul

  17. Optimal design of solar water heating systems | Alemu | Zede Journal

    African Journals Online (AJOL)

    Solar water heating systems are usually designed using simplified equation of annual efficiency of the heating system from solar radiation incident on the collector during the year and empirical values of annual efficiency. The pe1formance of the preliminary design is predicted by using either/chart method or by translate it ...

  18. Solar heating and hot water system installed at office building, One Solar Place, Dallas, Texas

    Science.gov (United States)

    1980-01-01

    A solar heating on cooling system is described which is designed to provide 87 percent of the space heating needs, 100 percent of the potable hot water needs and is sized for future absorption cooling. The collection subsystem consists of 28 solargenics, series 76, flat plate collectors with a total area of 1,596 square feet. The solar loop circulates an ethylene glyco water solution through the collectors into a hot water system exchanger. The water storage subsystem consists of a heat exchanger, two 2,300 gallon concrete hot water storage tanks with built in heat exchangers and a back-up electric boiler. The domestic hot water subsystem sends hot water to the 10,200 square feet floor area office building hot water water fixtures. The building cold water system provides make up to the solar loop, the heating loop, and the hot water concrete storage tanks. The design, construction, cost analysis, operation and maintenance of the solar system are described.

  19. Technical Analysis of Combined Solar Water Heating Systems for Cold Climate Regions

    OpenAIRE

    Hossein Lotfizadeh; André McDonald; Amit Kumar

    2016-01-01

    Renewable energy resources, which can supplement space and water heating for residential buildings, can have a noticeable impact on natural gas consumption and air pollution. This study considers a technical analysis of a combined solar water heating system with evacuated tube solar collectors for different solar coverage, ranging from 20% to 100% of the total roof area of a typical residential building located in Edmonton, Alberta, Canada. The alternative heating systems were conventional (n...

  20. Solar heating and hot water system installed at Shoney's Restaurant, North Little Rock, Arkansas

    Science.gov (United States)

    1980-01-01

    A solar heating system designed to supply a major portion of the space and water heating requirements for a restaurant is described. The restaurant has a floor space of approximately 4,650 square feet and requires approximate 1500 gallons of hot water daily. The solar energy system consists of 1,428 square feet of Chamberlain flat plate liquid collector subsystem, and a 1500 gallon storage subsystem circulating hot water producing 321 x 10 to the 6th power Btu/Yr (specified) building heating and hot water heating.

  1. System design package for SIMS prototype system 3, solar heating and domestic hot water

    Energy Technology Data Exchange (ETDEWEB)

    1978-11-01

    This report is a collation of documents and drawings that describe a prototype solar heating and hot water system using liquid flat plat collectors and a gas or electric furnace energy subsystem. The system was designed for installation into a single-family dwelling. The description, performance specification, subsystem drawings, verification plan/procedure, and hazard analysis of the system are packaged for evaluation of the system with information sufficient to assemble a similar system. The SIMS Prototype Heating and Hot Water System, Model Number 3 has been installed in a residence at Glendo State Park, Glendo, Wyoming.

  2. Solar heating and hot water system installed at Listerhill, Alabama

    Science.gov (United States)

    1978-01-01

    The Solar system was installed into a new building and was designed to provide 79% of the estimated annual space heating load and 59% of the estimated annual potable hot water requirement. The collectors are flat plate, liquid manufactured by Reynolds Metals Company and cover a total area of 2344 square feet. The storage medium is water inhibited with NALCO 2755 and the container is an underground, unpressurized steel tank with a capacity of 5000 gallons. This report describes in considerable detail the solar heating facility and contains detailed drawings of the completed system.

  3. System design package for IBM system one: solar heating and domestic hot water

    Science.gov (United States)

    1977-01-01

    This report is a collation of documents and drawings that describe a prototype solar heating and hot water system using air as the collector fluid and a pebble bed for heat storage. The system was designed for installation into a single family dwelling. The description, performance specification, subsystem drawings, verification plan/procedure, and hazard analysis of the system was packaged for evaluation of the system with information sufficient to assemble a similar system.

  4. Annual performance of building-integrated photovoltaic/water-heating system for warm climate application

    International Nuclear Information System (INIS)

    Chow, T.T.; Chan, A.L.S.; Fong, K.F.; Lin, Z.; He, W.; Ji, J.

    2009-01-01

    A building-integrated photovoltaic/water-heating (BiPVW) system is able to generate higher energy output per unit collector area than the conventional solar systems. Through computer simulation with energy models developed for this integrative solar system in Hong Kong, the results showed that the photovoltaic/water-heating (PVW) system has economic advantages over the conventional photovoltaic (PV) installation. The system thermal performance under natural water circulation was found better than the pump-circulation mode. For a specific BiPVW system at a vertical wall of a fully air-conditioned building and with collectors equipped with flat-box-type thermal absorber and polycrystalline silicon cells, the year-round thermal and cell conversion efficiencies were found respectively 37.5% and 9.39% under typical Hong Kong weather conditions. The overall heat transmission through the PVW wall is reduced to 38% of the normal building facade. When serving as a water pre-heating system, the economical payback period was estimated around 14 years. This greatly enhances the PV market opportunities. (author)

  5. Evaluation of a flue gas driven open absorption system for heat and water recovery from fossil fuel boilers

    International Nuclear Information System (INIS)

    Wang, Zhenying; Zhang, Xiaoyue; Li, Zhen

    2016-01-01

    Highlights: • Flue gas driven open absorption system that efficiently recovers total heat. • Efficient heat and water recovery for various kinds of fossil fuel boilers. • Heat and water recovery efficiencies increase with moisture content of flue gas. • Temperature requirements for district heat supply and domestic hot water were met. • Experimental system surpasses conventional condensing system in total heat recovery. - Abstract: This paper presents an open absorption system for total heat recovery from fossil fuel boilers using the high temperature flue gas as the regeneration heat source. In this system, liquid desiccant serves as the recycling medium, which absorbs waste heat and moisture contained in the low temperature flue gas in the packed tower and then regenerates in the regenerator by the high temperature flue gas. Water vapor generated in the regenerator gets condensed after releasing heat to the heating water system and the condensing water also gets recycled. The return water collects heat from the solution water heat exchanger, the flue gas water heat exchanger and the condenser respectively and is then used for district heating. Driven by the vapor pressure difference between high humidity flue gas and the liquid desiccant, the heat recovery efficiency of the system is not limited by the dew point of the flue gas, enabling a warmer water to be heated up than the conventional condensing boiler. The performance of this system was analyzed theoretically and experimentally and the results showed that the system operated well for both district heat supply and domestic hot water supply. The system efficiency increased with the moisture content of flue gas and the total heat recovery was about 8.5%, 17.2%, 21.2%, and 9.2% higher than the conventional condensing system in the case of coal fired boiler, fuel oil boiler, natural gas boiler, and coke oven gas boiler, respectively.

  6. Heat transfer coefficient: Medivance Arctic Sun Temperature Management System vs. water immersion.

    Science.gov (United States)

    English, M J; Hemmerling, T M

    2008-07-01

    To improve heat transfer, the Medivance Arctic Sun Temperature Management System (Medivance, Inc., Louisville, CO, USA) features an adhesive, water-conditioned, highly conductive hydrogel pad for intimate skin contact. This study measured and compared the heat transfer coefficient (h), i.e. heat transfer efficiency, of this pad (hPAD), in a heated model and in nine volunteers' thighs; and of 10 degrees C water (hWATER) in 33 head-out immersions by 11 volunteers. Volunteer studies had ethical approval and written informed consent. Calibrated heat flux transducers measured heat flux (W m-2). Temperature gradient (DeltaT) was measured between skin and pad or water temperatures. Temperature gradient was changed through the pad's water temperature controller or by skin cooling on immersion. The heat transfer coefficient is the slope of W m-2/DeltaT: its unit is W m-2 degrees C-1. Average with (95% CI) was: model, hPAD = 110.4 (107.8-113.1), R2 = 0.99, n = 45; volunteers, hPAD = 109.8 (95.5-124.1), R2 = 0.83, n = 51; and water immersion, hWATER = 107.1 (98.1-116), R2 = 0.86, n = 94. The heat transfer coefficient for the pad was the same in the model and volunteers, and equivalent to hWATER. Therefore, for the same DeltaT and heat transfer area, the Arctic Sun's heat transfer rate would equal water immersion. This has important implications for body cooling/rewarming rates.

  7. High efficient ammonia heat pump system for industrial process water using the ISEC concept. Part 1

    DEFF Research Database (Denmark)

    Rothuizen, Erasmus Damgaard; Madsen, C.; Elmegaard, Brian

    2014-01-01

    The purpose of the Isolated System Energy Charging (ISEC) is to provide a high-efficient ammonia heat pump system for hot water production. The ISEC concept uses two storage tanks for the water, one discharged and one charged. The charged tank is used for the industrial process while the discharged...... tank, is charging. Charging is done by circulating the water in the tank through the condenser several times and thereby gradually heats the water. This result in a lower condensing temperature than if the water was heated in one step. A dynamic model of the system, implemented in Dymola, is used...... to investigate the performance of the ISEC system. The ISEC concept approaches the efficiency of a number of heat pumps in series and the COP of the system may reach 6.8, which is up to 25 % higher than a conventional heat pump heating water in one step....

  8. Improved Design Tools for Surface Water and Standing Column Well Heat Pump Systems (DE-EE0002961)

    Energy Technology Data Exchange (ETDEWEB)

    Spitler, J. D.; Culling, J. R.; Conjeevaram, K.; Ramesh, M.; Selvakumar, M.

    2012-11-30

    Ground-source heat pump (GSHP) systems are perhaps the most widely used “sustainable” heating and cooling systems, with an estimated 1.7 million installed units with total installed heating capacity on the order of 18 GW. They are widely used in residential, commercial, and institutional buildings. Standing column wells (SCW) are one form of ground heat exchanger that, under the right geological conditions, can provide excellent energy efficiency at a relatively low capital cost. Closed-loop surface water heat pump (SWHP) systems utilize surface water heat exchangers (SWHE) to reject or extract heat from nearby surface water bodies. For building near surface water bodies, these systems also offer a high degree of energy efficiency at a low capital cost. However, there have been few design tools available for properly sizing standing column wells or surface water heat exchangers. Nor have tools for analyzing the energy consumption and supporting economics-based design decisions been available. The main contributions of this project lie in providing new tools that support design and energy analysis. These include a design tool for sizing surface water heat exchangers, a design tool for sizing standing column wells, a new model of surface water heat pump systems implemented in EnergyPlus and a new model of standing column wells implemented in EnergyPlus. These tools will better help engineers design these systems and determine the economic and technical feasibility.

  9. Heating and Domestic Hot Water Systems in Buildings Supplied by Low-Temperature District Heating

    DEFF Research Database (Denmark)

    Brand, Marek

    solutions simply redirect the bypassed water back to the DH network without additional cooling, but bypassed water can instead be redirected to floor heating in the bathroom to be further cooled and thus reduce heat loss from the DH network while improving comfort for occupants and still ensure fast DHW...... increased risk of Legionella if the DH substation and DHW system are designed for the low-temperature supply conditions. To ensure the fast provision of DHW during non-heating periods, the supply service pipe should be kept warm, preferably with the bypass solution redirecting the bypass flow to bathroom...... temperature. To accord with the literature, the modelling of internal heat gains reflected the improved efficiency of equipment by reduction of value from 5W/m2 to 4.2W/m2, also modelled as intermittent heat gains based on a realistic week schedule. Furthermore, the indoor set-point temperature was increased...

  10. Solar heating and hot water system installed at Cherry Hill, New Jersey. [Hotels

    Energy Technology Data Exchange (ETDEWEB)

    1979-05-16

    The solar heating and hot water system installed in existing buildings at the Cherry Hill Inn in Cherry Hill, New Jersey is described in detail. The system went into operation November 8, 1978 and is expected to furnish 31.5% of the overall heating load and 29.8% of the hot water load. The collectors are General Electric Company liquid evacuated tube type. The storage system is an above ground insulated steel water tank with a capacity of 7,500 gallons.

  11. Techno-Economic Analysis of Solar Water Heating Systems inTurkey.

    Science.gov (United States)

    Ertekin, Can; Kulcu, Recep; Evrendilek, Fatih

    2008-02-25

    In this study, solar water heater was investigated using meteorological and geographical data of 129 sites over Turkey. Three different collector types were compared in terms of absorber material (copper, galvanized sheet and selective absorber). Energy requirement for water heating, collector performances, and economical indicators were calculated with formulations using observed data. Results showed that selective absorbers were most appropriate in terms of coverage rate of energy requirement for water-heating all over Turkey. The prices of selective, copper and galvanized absorber type's heating systems in Turkey were 740.49, 615.69 and 490.89 USD, respectively. While payback periods (PBPs) of the galvanized absorber were lower, net present values (NPVs) of the selective absorber were higher than the rest. Copper absorber type collectors did not appear to be appropriate based on economical indicators.

  12. Investigation of a low flow solar heating system for space heating and domestic hot water supply for Aidt Miljø A/S

    DEFF Research Database (Denmark)

    Vejen, Niels Kristian

    1997-01-01

    A low flow solar heating system for space heating and domestic hot water supply from Aidt Miljø A/Swas tested in a laboratory test facility.......A low flow solar heating system for space heating and domestic hot water supply from Aidt Miljø A/Swas tested in a laboratory test facility....

  13. System design package for SIMS Prototype System 4, solar heating and domestic hot water

    Energy Technology Data Exchange (ETDEWEB)

    1978-11-01

    This report is a collation of documents and drawings that describe a prototype solar heating and hot water system using air type solar energy collection techniques. The system consists of a modular designed prepackaged solar unit containing solar collctors, a rock storage container, blowers, dampers, ducting, air-to-water heat exchanger, DHW preheat tank, piping and system controls. The system was designed to be installed adjacent to a small single family dwelling. The description, performance specification, subsystem drawings, verification plan/procedure, and hazard analysis of the system are packaged for evaluation of the system with inforation sufficient to assemble a similar system. The prepackage solar unit has been installed at the Mississippi Power and Light Company, Training Facilities, Clinton, Mississippi.

  14. Investigation of a solar heating system for space heating and domestic hot water supply for Sol&Træ A.m.b.a

    DEFF Research Database (Denmark)

    Vejen, Niels Kristian

    1999-01-01

    A solar heating system for space heating and domestic hot water supply from "Sol&Træ A.m.b.a." was tested in a laboratory test facility.......A solar heating system for space heating and domestic hot water supply from "Sol&Træ A.m.b.a." was tested in a laboratory test facility....

  15. Development of hot water supply system for a small district heating reactor

    International Nuclear Information System (INIS)

    Murase, Toshihiko; Narabayashi, Tadashi; Shimazu, Yoichiro

    2007-01-01

    On the earth, there are many environmental problems. For example, rapid increase of world population causes the enormous consumption of fossil fuel and emission of CO 2 into the global air. Now, mankaind faced to deal with these serious problems. One solution for these problems is utilization of nuclear reactors. Currently, about 65% of thermal output of a nuclear reactor is thrown away to the sea or the atmosphere through a turbine condenser. When a hot-water pipeline from a nuclear plant will be constructed, the exhaust heat from nuclear reactor will able to be utilized. Therefore, authors began to study nuclear power plant system for district heating. This reactor is based on a PWR plant. Its thermal output is 10 MWth and its electrical output is 3.4 MW. The nuclear plant supply electricity and heat for 2000 to 3000 houses. The plant aim to supply all the energy for the adjacent pepole's life, for example, heat, electricity and hydrogen for fuel battery car. This total-energy supply system assumed to be built in Northern area such as Hokkaido in Japan. In order to develop an optimum thermal design method for the system, heat transport experiments and thermal-hydraulic calculations were carried out. Using a metal pipe covered with foam-polyurethane thermal insulator, feed-water temperature and return-water temperature was measured to evaluate heat loss. As the result, the heat loss from the hot-water temperature was very little. The thermal-hydraulic calculation method was verified and applied to actual pipeline size calculation. The result of heat loss calculation will be 0.2degC/5 km. considering these results, the best pipe specification was obtained. (author)

  16. Solar heating and hot water system installed at office building, One Solar Place, Dallas, Texas. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1980-06-01

    This document is the Final Report of the Solar Energy System Installed at the First Solar Heated Office Building, One Solar Place, Dallas, Texas. The Solar System was designed to provide 87 percent of the space heating needs, 100 percent of the potable hot water needs and is sized for future absorption cooling. The collection subsystem consists of 28 Solargenics, series 76, flat plate collectors with a total area of 1596 square feet. The solar loop circulates an ethylene glycol-water solution through the collectors into a hot water system heat exchanger. The hot water storage subsystem consists of a heat exchanger, two 2300 gallon concrete hot water storage tanks with built in heat exchangers and a back-up electric boiler. The domestic hot water subsystem sends hot water to the 10,200 square feet floor area office building hot water fixtures. The building cold water system provides make-up to the solar loop, the heating loop, and the hot water concrete storage tanks. The design, construction, cost analysis, operation and maintenance of the solar system are described. The system became operational July 11, 1979.

  17. Solar heating, cooling and domestic hot water system installed at Columbia Gas System Service Corporation, Columbus, Ohio

    Science.gov (United States)

    1980-01-01

    The solar energy system installed in the building has 2,978 sq ft of single axis tracking, concentrating collectors and provides solar energy for space heating, space cooling and domestic hot water. A 1,200,000 Btu/hour water tube gas boiler provides hot water for space heating. Space cooling is provided by a 100 ton hot water fired absorption chiller. Domestic hot water heating is provided by a 50 gallon natural gas domestic storage water heater. Extracts from the site files, specification references, drawings, installation, operation and maintenance instructions are included.

  18. Residential solar-heating system

    Science.gov (United States)

    1978-01-01

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

  19. Installation package for a domestic solar heating and hot water system

    Science.gov (United States)

    1978-01-01

    The installation of two prototype solar heating and hot water systems is described. The systems consists of the following subsystems: solar collector, storage, control, transport, and auxiliary energy.

  20. Preliminary design package for solar heating and hot water system

    Science.gov (United States)

    1977-01-01

    The preliminary design review on the development of a multi-family solar heating and domestic hot water prototype system is presented. The report contains the necessary information to evaluate the system. The system consists of the following subsystems: collector, storage, transport, control and Government-furnished site data acquisition.

  1. Solar heating and hot water system installed at Southeast of Saline, Unified School District 306, Mentor, Kansas

    Science.gov (United States)

    1979-01-01

    The solar system, installed in a new building, was designed to provide 52 percent of the estimated annual space heating load and 84 percent of the estimated annual potable hot water requirement. The liquid flat plate collectors are ground-mounted and cover a total area of 5125 square feet. The system will provide supplemental heat for the school's closed-loop water-to-air heat pump system and domestic hot water. The storage medium is water inside steel tanks with a capacity of 11,828 gallons for space heating and 1,600 gallons for domestic hot water. The solar heating facility is described and drawings are presented of the completed system which was declared operational in September 1978, and has functioned successfully since.

  2. Simulation of hybrid ground-coupled heat pump with domestic hot water heating systems using HVACSIM+

    Energy Technology Data Exchange (ETDEWEB)

    Cui, Ping; Yang, Hongxing [Department of Building Services Engineering, The Hong Kong Polytechnic University, Hong Kong (China); Spitler, Jeffrey D. [School of Mechanical Engineering, Oklahoma State University (United States); Fang, Zhaohong [Ground Source Heat Pump Research Center, Shandong University of Architecture and Engineering, Jinan (China)

    2008-07-01

    A hybrid ground-coupled heat pump (HGCHP) with domestic hot water (DHW) supply system has been proposed in this paper for space cooling/heating and DHW supply for residential buildings in hot-climate areas. A simulation model for this hybrid system is established within the HVACSIM+ environment. A sample system, applied for a small residential apartment located in Hong Kong, is hourly simulated in a typical meteorological year. The conventional GCHP system and an electric heater for DHW supply are also modeled and simulated on an hourly basis within the HVACSIM+ for comparison purpose. The results obtained from this case study show that the HGCHP system can effectively alleviate the imbalanced loads of the ground heat exchanger (GHE) and can offer almost 95% DHW demand. The energy saving for DHW heating is about 70% compared with an electric heater. This proposed scheme, i.e. the HGCHP with DHW supply, is suitable to residential buildings in hot-climate areas, such as in Hong Kong. (author)

  3. Techno-Economic Analysis of Solar Water Heating Systems inTurkey

    Directory of Open Access Journals (Sweden)

    Fatih Evrendilek

    2008-02-01

    Full Text Available In this study, solar water heater was investigated using meteorological and geographical data of 129 sites over Turkey. Three different collector types were compared in terms of absorber material (copper, galvanized sheet and selective absorber. Energy requirement for water heating, collector performances, and economical indicators were calculated with formulations using observed data. Results showed that selective absorbers were most appropriate in terms of coverage rate of energy requirement for water-heating all over Turkey. The prices of selective, copper and galvanized absorber type’s heating systems in Turkey were 740.49, 615.69 and 490.89 USD, respectively. While payback periods (PBPs of the galvanized absorber were lower, net present values (NPVs of the selective absorber were higher than the rest. Copper absorber type collectors did not appear to be appropriate based on economical indicators.

  4. ACCOUNTING FOR NONUNIFORMITY OF WATER CONSUMPTION IN THE EXHAUST AIR HEAT RECLAMATION SYSTEMS FOR HOT WATER SUPPLY

    Directory of Open Access Journals (Sweden)

    Samarin Oleg Dmitrievich

    2017-03-01

    Full Text Available This article is devoted to assessment of the influence of variation of daily hot water consumption on the predicted energy effect by using heat recovery of exhaust air in typical exhaust ventilation systems of the most commonly used flat buildings during their switch to the mechanical induction for the pre-heating of water for hot water supply. It outlines the general principle of the organization of this method of energy saving and presents the basic equations of heat transfer in the heat exchanger. The article proposes a simplified method of accounting for changes in the heat transfer coefficient of air-to-water heat exchanger with fluctuations of water demand using existing dependencies for this coefficient from the rate flow of heating and heated fluid through the device. It presents observations to identify the parameters of the real changes of water consumption during the day with the main quantitative characteristics of normally distributed random variables. Calculation of thermal efficiency of the heat exchange equipment using dimensionless parameters through the number of heat transfer under the optimal opposing scheme of fluid motion is completed under conditions of variable water flow rate for the type residential building of the П3-1/16 series using the Monte Carlo method for numerical modeling of stochastic processes. The estimation of the influence of fluctuation of the current water consumption on the instantaneous thermal efficiency factor of the heat exchanger and the total energy consumption of the building is given, and it is shown that the error of said calculation using average daily parameters is within the margin of usual engineering calculation.

  5. Design, Fabrication, and Efficiency Study of a Novel Solar Thermal Water Heating System: Towards Sustainable Development

    OpenAIRE

    M. Z. H. Khan; M. R. Al-Mamun; S. Sikdar; P. K. Halder; M. R. Hasan

    2016-01-01

    This paper investigated a novel loop-heat-pipe based solar thermal heat-pump system for small scale hot water production for household purposes. The effective use of solar energy is hindered by the intermittent nature of its availability, limiting its use and effectiveness in domestic and industrial applications especially in water heating. The easiest and the most used method is the conversion of solar energy into thermal energy. We developed a prototype solar water heating system for experi...

  6. Side-by-Side Testing of Water Heating Systems: Results from the 2013-2014 Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Colon, Carlos [Florida Solar Energy Center, Cocoa, FL (United States). Bulding America Partnership for Improved Residential Construction

    2017-07-12

    The Florida Solar Energy Center (FSEC) has completed a fourth year-long evaluation on residential hot water heating systems in a laboratory environment (east central Florida, hot-humid climate). This report contains a summary of research activities regarding the evaluation of two residential electric heat pump water heaters (HPWHs), a solar thermal system utilizing a polymer glazed absorber and a high efficiency natural gas system.

  7. Performance of a day/night water heat storage system for heating and cooling of semi-closed greenhouses in mild winter climate

    NARCIS (Netherlands)

    Baeza, E.J.; Pérez Parra, J.J.; López, J.C.; Gázquez, J.C.; Meca, D.E.; Stanghellini, C.; Kempkes, F.L.K.; Montero, J.I.

    2012-01-01

    A novel system for heating/cooling greenhouses based on air/water heat exchangers connected to a thermally stratified water storage tank was tested in a small greenhouse compartment at the Experimental Station of the Cajamar Foundation in Almería, Spain. The system maintained a closed greenhouse (no

  8. Alternative solutions for inhibiting Legionella in domestic hot water systems based on low-temperature district heating

    DEFF Research Database (Denmark)

    Yang, Xiaochen; Li, Hongwei; Svendsen, Svend

    2015-01-01

    Abstract District heating is a cost-effective way of providing heat to high heat density areas. Low-temperature district heating (LTDH) is a promising way to make district heating more energy-efficient and adaptable to well-insulated buildings with low heating demand in the future. However, one c...... systems. They have the additional benefit of reducing the heat loss of the hot water system. The alternative design solutions both enrich our options for water sanitation and improve the energy efficiency of our energy systems....... concern is the multiplication of Legionella due to insufficient temperature elevation with low-temperature supply. The aim of this study was to find optimal solutions to this dilemma for specific situations. The solutions were of two types: alternative system designs and various methods of sterilization...... methods, thermal treatment, ionization, chlorine, chlorine dioxide, ultraviolet light, photocatalysis and filtration are discussed as the most frequently used methods in hot water systems. The characteristics, efficacy and operation methods of LTDH using the solutions investigated are documented...

  9. A concept of passive safety pressurized water reactor system with inherent matching nature of core heat generation and heat removal

    International Nuclear Information System (INIS)

    Murao, Yoshio; Araya, Fumimasa; Iwamura, Takamichi; Okumura, Keisuke

    1995-01-01

    The reduction of manpower in operation and maintenance by simplification of the system are essential to improve the safety and the economy of future light water reactors. At the Japan Atomic Energy Research Institute (JAERI), a concept of a simplified passive safety reactor system JPSR was developed for this purpose and in the concept minimization of developing work and conservation of scale-up capability in design were considered. The inherent matching nature of core heat generation and heat removal rate is introduced by the core with high reactivity coefficient for moderator density and low reactivity coefficient for fuel temperature (Doppler effect) and once-through steam generators (SGs). This nature makes the nuclear steam supply system physically-slave for the steam and energy conversion system by controlling feed water mass flow rate. The nature can be obtained by eliminating chemical shim and adopting in-vessel control rod drive mechanism (CRDM) units and a low power density core. In order to simplify the system, a large pressurizer, canned pumps, passive residual heat removal systems with air coolers as a final heat sink and passive coolant injection system are adopted and the functions of volume and boron concentration control and seal water supply are eliminated from the chemical and volume control system (CVCS). The emergency diesel generators and auxiliary component cooling system of 'safety class' for transferring heat to sea water as a final heat sink in emergency are also eliminated. All of systems are built in the containment except for the air coolers of the passive residual heat removal system. The analysis of the system revealed that the primary coolant expansion in 100% load reduction in 60 s can be mitigated in the pressurizer without actuating the pressure relief valves and the pressure in 50% load change in 30 s does not exceed the maximum allowable pressure in accidental conditions in regardless of pressure regulation. (author)

  10. Waste heat recovery system

    International Nuclear Information System (INIS)

    Phi Wah Tooi

    2010-01-01

    Full text: The Konzen in-house designed anaerobic digester system for the POME (Palm Oil Mill Effluent) treatment process is one of the registered Clean Development Mechanism (CDM) projects in Malaysia. It is an organic wastewater treatment process which achieves excellent co-benefits objectives through the prevention of water pollution and reduction of greenhouse gas emissions, which is estimated to be 40,000 to 50,000 t-CO 2 per year. The anaerobic digester was designed in mesophile mode with temperature ranging from 37 degree Celsius to 45 degree Celsius. A microorganisms growth is optimum under moderately warm temperature conditions. The operating temperature of the anaerobic digester needs to be maintained constantly. There are two waste heat recovery systems designed to make the treatment process self-sustaining. The heat recovered will be utilised as a clean energy source to heat up the anaerobic digester indirectly. The first design for the waste heat recovery system utilises heat generated from the flue gas of the biogas flaring system. A stainless steel water tank with an internal water layer is installed at the top level of the flare stack. The circulating water is heated by the methane enriched biogas combustion process. The second design utilizes heat generated during the compression process for the biogas compressor operation. The compressed biogas needs to be cooled before being recycled back into the digester tank for mixing purposes. Both the waste heat recovery systems use a design which applies a common water circulation loop and hot water tank to effectively become a closed loop. The hot water tank will perform both storage and temperature buffer functions. The hot water is then used to heat up recycled sludge from 30 degree Celsius to 45 degree Celsius with the maximum temperature setting at 50 degree Celsius. The recycled sludge line temperature will be measured and monitored by a temperature sensor and transmitter, which will activate the

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

    Directory of Open Access Journals (Sweden)

    Jinshun Wu

    2013-01-01

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

  12. PORTABLE PEM FUEL CELL SYSTEM: WATER AND HEAT MANAGEMENT

    Directory of Open Access Journals (Sweden)

    SITI NAJIBAH ABD RAHMAN

    2016-07-01

    Full Text Available Portable polymer electrolyte membrane (PEM fuel cell power generator is a PEM fuel cell application that is used as an external charger to supply the demand for high energy. Different environments at various ambient temperatures and humidity levels affect the performance of PEM fuel cell power generators. Thermal and water management in portable PEM fuel cells are a critical technical barrier for the commercialization of this technology. The size and weight of the portable PEM fuel cells used for thermal and water management systems that determine the performance of portable PEM fuel cells also need to be considered. The main objective of this paper review was to determine the importance of water and thermal management systems in portable PEM fuel cells. Additionally, this review investigated heat transfer and water transport in PEM fuel cells. Given that portable PEM fuel cells with different powers require different thermal and water management systems, this review also discussed and compared management systems for low-, medium-, and high-power portable PEM fuel cells.

  13. Design, Fabrication, and Efficiency Study of a Novel Solar Thermal Water Heating System: Towards Sustainable Development

    Directory of Open Access Journals (Sweden)

    M. Z. H. Khan

    2016-01-01

    Full Text Available This paper investigated a novel loop-heat-pipe based solar thermal heat-pump system for small scale hot water production for household purposes. The effective use of solar energy is hindered by the intermittent nature of its availability, limiting its use and effectiveness in domestic and industrial applications especially in water heating. The easiest and the most used method is the conversion of solar energy into thermal energy. We developed a prototype solar water heating system for experimental test. We reported the investigation of solar thermal conversion efficiency in different seasons which is 29.24% in summer, 14.75% in winter, and 15.53% in rainy season. This paper also discusses the DC heater for backup system and the current by using thermoelectric generator which are 3.20 V in summer, 2.120 V in winter, and 1.843 V in rainy season. This solar water heating system is mostly suited for its ease of operation and simple maintenance. It is expected that such novel solar thermal technology would further contribute to the development of the renewable energy (solar driven heating/hot water service and therefore lead to significant environmental benefits.

  14. Investigation on Solar Heating System with Building-Integrated Heat Storage

    DEFF Research Database (Denmark)

    Heller, Alfred

    1996-01-01

    Traditional solar heating systems cover between 5 and 10% of the heat demand fordomestic hot water and comfort heating. By applying storage capacity this share can beincreased much. The Danish producer of solar heating systems, Aidt-Miljø, markets such a system including storage of dry sand heated...... by PP-pipe heat exchanger. Heat demand is reduced due to direct solar heating and due to storage. The storage affects the heat demand passively due to higher temperatures. Hence heat loss is reduced and passive heating is optioned. In theory, by running the system flow backwards, active heating can...... solar collector area of the system, was achieved. Active heating from the sand storage was not observed. The pay-back time for the system can be estimated to be similar to solar heated domestic hot water systems in general. A number of minor improvements on the system could be pointed out....

  15. Design guide for heat transfer equipment in water-cooled nuclear reactor systems

    International Nuclear Information System (INIS)

    1975-07-01

    Information pertaining to design methods, material selection, fabrication, quality assurance, and performance tests for heat transfer equipment in water-cooled nuclear reactor systems is given in this design guide. This information is intended to assist those concerned with the design, specification, and evaluation of heat transfer equipment for nuclear service and the systems in which this equipment is required. (U.S.)

  16. A run-around heat exchanger system to improve the energy efficiency of a home appliance using hot water

    International Nuclear Information System (INIS)

    Park, Jae Sung; Jacobi, Anthony M.

    2009-01-01

    A significant portion of the energy consumed by many home appliances using hot water is used to heat cold supply water. Such home appliances generally are supplied water at a temperature lower than the ambient temperature, and the supply water is normally heated to its maximum operating temperature, often using natural gas or an electrical heater. In some cases, it is possible to pre-heat the supply water and save energy that would normally be consumed by the natural gas or electrical heater. In order to save the energy consumed by an appliance using water heater, a run-around heat exchanger system is used to transfer heat from the ambient to the water before an electrical heater is energized. A simple model to predict the performance of this system is developed and validated, and the model is used to explore design and operating issues relevant to the run-around heat exchanger system. Despite the additional power consumption by the fan and pump of the run-around heat exchanger system, the experimental data and analysis show that for some systems the overall energy efficiency of the appliance can be improved, saving about 6% of the energy used by the baseline machine.

  17. Retrofitting Domestic Hot Water Heaters for Solar Water Heating Systems in Single-Family Houses in a Cold Climate: A Theoretical Analysis

    Directory of Open Access Journals (Sweden)

    Björn Karlsson

    2012-10-01

    Full Text Available One of the biggest obstacles to economic profitability of solar water heating systems is the investment cost. Retrofitting existing domestic hot water heaters when a new solar hot water system is installed can reduce both the installation and material costs. In this study, retrofitting existing water heaters for solar water heating systems in Swedish single-family houses was theoretically investigated using the TRNSYS software. Four simulation models using forced circulation flow with different system configurations and control strategies were simulated and analysed in the study. A comparison with a standard solar thermal system was also presented based on the annual solar fraction. The simulation results indicate that the retrofitting configuration achieving the highest annual performance consists of a system where the existing tank is used as storage for the solar heat and a smaller tank with a heater is added in series to make sure that the required outlet temperature can be met. An external heat exchanger is used between the collector circuit and the existing tank. For this retrofitted system an annual solar fraction of 50.5% was achieved. A conventional solar thermal system using a standard solar tank achieves a comparable performance for the same total storage volume, collector area and reference conditions.

  18. Legionellae in water heating systems. Legionellen in Warmwasserbereitungsanlagen

    Energy Technology Data Exchange (ETDEWEB)

    1991-10-01

    A Public Health Office inquiry submitted to the Building Surveyor's Office about prophylactic measures taken to protect the health of bathers at the Vonderort saltwater pools was followed by a detailed inquiry among AMEV members. It was found that most of the persons interviewed did not have sufficient experience in using water heating methods which completely ban legionellae. However, several administrative authorities considered a 60deg C thermal tap water disinfection a necessary protective measure. A circular regulation was subsequently issued by the Northrhine-Westphalian Ministry for Building Construction and Housing to improve legionella protection. Details are also given about the protective measures and maintenance schemes issued by the Public Health Office for drinking water and space HVAC systems. (BWI).

  19. High efficient ammonia heat pump system for industrial process water using the ISEC concept. Part 2

    DEFF Research Database (Denmark)

    Olesen, Martin F.; Madsen, Claus; Olsen, Lars

    2014-01-01

    The Isolated System Energy Charging (ISEC) concept allows for a high efficiency of a heat pump system for hot water production. The ISEC concept consists of two water storage tanks, one charged and one discharged. The charged tank is used for the industrial process, while the discharged tank...... is charging. The charging of the tank is done by recirculating water through the condenser and thereby gradually heating the water. The modelling of the system is described in Part I [1]. In this part, Part II, an experimental test setup of the tank system is reported, the results are presented and further...... modelling of the heat pump and tank system is performed (in continuation of Part I). The modelling is extended to include the system performance with different natural refrigerants and the influence of different types of compressors....

  20. Operation Performance of Central Solar Heating System with Seasonal Storage Water Tank in Harbin

    Institute of Scientific and Technical Information of China (English)

    YE Ling; JIANG Yi-qiang; YAO Yang; ZHANG Shi-cong

    2009-01-01

    This paper presented a preliminary research on the central solar heating system with seasonal stor-age(CSHSSS)used in cold climate in China.A mathematical model of the solar energy seasonal storage water tank used in the central solar heating system was firstly developed based on energy conservation.This was fol-lowed by the simulation of the CSHSSS used in a two-floor villa in Harbin,and analysis of the impacts on storage water temperature of tank volume,solar collector area,tank burial depth,insulation thickness around the tank,etc.The results show there is a relatively economical tank volume to optimize the system efficiency,which de-creases with increasing tank volume at the constant collector area,and increases with increasing collector area at the constant tank volume.Furthermore,the insulation thickness has obvious effect on avoiding heat loss,while the tank burial depth doesn't.In addition-the relationship between the solar collector efficiency and storage wa-ter temperature is also obtained,it decreases quickly with increasing storing water temperature,and then in-creases slowly after starting space heating system.These may be helpful for relevant design and optimization in cold climates in China and all over the world.

  1. Solar Water Heating with Low-Cost Plastic Systems

    Energy Technology Data Exchange (ETDEWEB)

    None

    2012-01-01

    Federal buildings consumed over 392,000 billion Btu of site delivered energy for buildings during FY 2007 at a total cost of $6.5 billion. Earlier data indicate that about 10% of this is used to heat water.[2] Targeting energy consumption in Federal buildings, the Energy Independence and Security Act of 2007 (EISA) requires new Federal buildings and major renovations to meet 30% of their hot water demand with solar energy, provided it is cost-effective over the life of the system. In October 2009, President Obama expanded the energy reduction and performance requirements of EISA and its subsequent regulations with his Executive Order 13514.

  2. Mitigating Climate Change by the Development and Deployment of Solar Water Heating Systems

    Directory of Open Access Journals (Sweden)

    S. T. Wara

    2013-01-01

    Full Text Available Solar energy is becoming an alternative for the limited fossil fuel resources. One of the simplest and most direct applications of this energy is the conversion of solar radiation into heat, which can be used in Water Heating Systems. Ogun State in Nigeria was used as a case study. The solar radiation for the state was explored with an annual average of 4.775 kWh/m2 recorded. The designed system comprised storage tanks and the collector unit which comprises wooden casing, copper tube, and aluminium foil. Test results for the unlagged and lagged storage tanks for water temperature at various angles of inclination (2.500°–20.000° were on the average 27.800°C and 28.300°C, respectively, for the inlet temperature and 60.100°C and 63.000°C for the outlet temperature, respectively. The efficiency of the Solar Water Heating System was 72.500% and the power saved 2.798 kW. The cost of the unit is put at 1121,400 ($145 as at August 2012. The unit developed can be applied for the purpose of reducing the cost of energy, dealing with environmental challenges, and improving the use of energy, hence serving as a climate mitigation process as this can be extended for water heating for domestic and other industrial purposes.

  3. Solar Water Heating with Low-Cost Plastic Systems (Brochure)

    Energy Technology Data Exchange (ETDEWEB)

    2012-01-01

    Newly developed solar water heating technology can help Federal agencies cost effectively meet the EISA requirements for solar water heating in new construction and major renovations. This document provides design considerations, application, economics, and maintenance information and resources.

  4. A study of a desuperheater heat recovery system complete with a reversibly used water cooling tower (RUWCT) for hot water supply

    Science.gov (United States)

    Tan, Kunxiong

    Recovering heat rejected from the condenser in a refrigeration system to generate service hot water for buildings is commonly seen in both tropics and subtropics. This study included a critical literature review on heat recovery from air-conditioning/refrigeration systems, with particular emphasis on the direct condenser heat recovery and its related mathematical simulation models. The review identified many applications of desuperheaters to small-scaled residential air-conditioning or heat pump units. The heat and mass transfer characteristics of a RUWCT have been studied in detail, which is based on the theory of direct contact heat and mass transfer between moist air and water. The thesis reports on the differences in the heat and mass transfer process that takes place in a RUWCT, a standard water cooling tower and a spray room. A corrective factor that accounts for the change of chilled water mass flow rate is incorporated into the theoretical analysis of a RUWCT. The algorithms developed from the theoretical analysis are capable of predicting the heat exchange capacity of a RUWCT at any operating conditions. This theoretical analysis is the first of its kind. Extensive field experimental work on the heat and mass transfer characteristics of a RUWCT has been carried out in a hotel building in Haikou, Hainan province of China, where the RUWCT is installed. Results from the experimental work indicate that the theoretical analysis can represent the heat and mass transfer characteristics in a RUWCT with an acceptable accuracy. A numerical analysis for a RUWCT is undertaken to determine both air and water states at intermediate horizontal sections along the tower height. Field experimental data confirm that the predicted air and water conditions at the tower inlet and outlet are of acceptable accuracy. A steady-state mathematical model is developed to simulate the operational performance of a water chiller plant complete with a desuperheater heat recovery system and

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-10-15

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

  6. Thermodynamic Heat Water by The Condenser of Refrigerator

    International Nuclear Information System (INIS)

    Ben Slama, Romdhane

    2009-01-01

    The present innovation relates to the coupling of a refrigerator to a cumulus to heat water and this, thanks to the heat yielded to the level of the condenser of the refrigerating system even. The heating of water is carried out thus without energy over consumption. The quantity of heat transferred by the water-cooled condenser is sufficient to raise the temperature of this latter with 60 degree at the end of five hours. This can satisfy completely or partially the requirements out of hot water of a family which can distribute its requirements out of hot water all along the day and the week. The quantity of heat recovered by water to heat rises with four multiples the power consumption by the compressor. The system thus makes it possible to save energy and to safeguard the environment

  7. Experimental studies on heat transfer and thermal performance characteristics of thermosyphon solar water heating system with helical and Left-Right twisted tapes

    International Nuclear Information System (INIS)

    Jaisankar, S.; Radhakrishnan, T.K.; Sheeba, K.N.

    2011-01-01

    Research highlights: → Conventional solar heaters are inefficient due to poor convective heat transfer. → Twisted tapes improve the heat transfer rate in solar water heater system. → Increase in outlet water temperature by 15 o C through the use of twisted tapes. →Thermal performance of twisted tape collector is 19% more than plain tube system. → Reduces collector area (0.6 m 2 ) whereas area for conventional collector is 1 m 2 . -- Abstract: Experimental investigation of heat transfer, friction factor and thermal performance of thermosyphon solar water heater system fitted with helical and Left-Right twist of twist ratio 3 has been performed and presented. The helical twisted tape induces swirl flow inside the riser tubes unidirectional over the length. But, in Left-Right system the swirl flow is bidirectional which increases the heat transfer and pressure drop when compared to the helical system. The experimental heat transfer and friction factors characteristics are validated with theoretical equations and the deviation falls with in the acceptable limits. The results show that heat transfer enhancement in twisted tape collector is higher than the plain tube collector. Compared to helical and Left-Right twisted tape system of same twist ratio 3, maximum thermal performance is obtained for Left-Right twisted tape collector with increase in solar intensity.

  8. Solar heating systems for heating and hot water

    Energy Technology Data Exchange (ETDEWEB)

    Schnaith, G; Dittrich, K

    1980-07-01

    Deutsche Bundesbahn has shown an interest in solar heating systems, too. The items discussed include the useful radiation energy, design features of collectors, heat carrier media, safeguards and profitability studies. The system installed by Deutsche Bundesbahn in the social services building of the Munich-Laim railway workshop is described. In conclusion, the test results of the first few months of service are given. In order to obtain unambiguous results, it appears indispensable to arrange for an additional total trial period of not less than two years and to conduct tests also on further systems presently under construction.

  9. Impacts of Water Quality on Residential Water Heating Equipment

    Energy Technology Data Exchange (ETDEWEB)

    Widder, Sarah H.; Baechler, Michael C.

    2013-11-01

    Water heating is a ubiquitous energy use in all residential housing, accounting for 17.7% of residential energy use (EIA 2012). Today, there are many efficient water heating options available for every fuel type, from electric and gas to more unconventional fuel types like propane, solar, and fuel oil. Which water heating option is the best choice for a given household will depend on a number of factors, including average daily hot water use (total gallons per day), hot water draw patterns (close together or spread out), the hot water distribution system (compact or distributed), installation constraints (such as space, electrical service, or venting accommodations) and fuel-type availability and cost. While in general more efficient water heaters are more expensive than conventional water heating technologies, the savings in energy use and, thus, utility bills can recoup the additional upfront investment and make an efficient water heater a good investment over time in most situations, although the specific payback period for a given installation will vary widely. However, the expected lifetime of a water heater in a given installation can dramatically influence the cost effectiveness and savings potential of a water heater and should be considered, along with water use characteristics, fuel availability and cost, and specific home characteristics when selecting the optimum water heating equipment for a particular installation. This report provides recommendations for selecting and maintaining water heating equipment based on local water quality characteristics.

  10. Heat transmission systems for heating and potable water. New requirements and problem solutions for hygiene, safety and improved heat utilization. Waermeuebertragungssysteme fuer Heizung und Trinkwasser. Neue Anforderungen und Problemloesungen bezueglich Hygiene, Sicherheit und besserer Waermenutzung

    Energy Technology Data Exchange (ETDEWEB)

    Kremer, R

    1989-10-01

    In the past, additional demands were made on heat transmission systems regarding hygienic requirements in potable water heating plant for hospitals, hotels, sanatoriums and old-age homes, safety requirements to protect the potable water from the penetration of hazardous substances and requirements for improved heat utilization through return flow cooling and condensate cooling in the district heating. Where potable water heaters are concerned, safety radiators for heat transfer which comply with the requirements of DIN 1988 Part 2 and Part 4, as well as water heaters with permanent disinfection which are legionnaires' disease-proof, are now available for use in hospitals, old age homes and sanatoriums. For the district heating sector, improved range systems with low concentration in the hot water sector as well as condensate heat utilizing systems have been further developed in the steam heating sector. (orig.).

  11. Monitoring of Danish marketed solar heating systems

    International Nuclear Information System (INIS)

    Ellehauge, K.

    1993-01-01

    The paper describes the monitoring of manufactured solar heating systems for domestic hot water combined with space heating and systems for domestic hot water only. Results from the monitoring of 5 marketed combined systems for domestic hot water and space heating are presented. The systems situated at one family houses at different sites in Denmark have been monitored from January/February 1992. For the detailed monitoring of manufactured systems only for domestic hot water a test facility for simultaneous monitoring of 5 solar heating systems has been established at the Thermal Insulation Laboratory. (au)

  12. Measure Guideline: Combined Space and Water Heating Installation and Optimization

    Energy Technology Data Exchange (ETDEWEB)

    Schoenbauer, B. [NorthernSTAR Building America Partnership, St. Paul, MN (United States); Bohac, D. [NorthernSTAR Building America Partnership, St. Paul, MN (United States); Huelman, P. [NorthernSTAR Building America Partnership, St. Paul, MN (United States)

    2017-03-01

    Combined space and water heater (combi or combo) systems are defined by their dual functionality. Combi systems provide both space heating and water heating capabilities with a single heat source. This guideline will focus on the installation and operation of residential systems with forced air heating and domestic hot water (DHW) functionality. Past NorthernSTAR research has used a combi system to replace a natural gas forced air distribution system furnace and tank type water heater (Schoenbauer et al. 2012; Schoenbauer, Bohac, and McAlpine 2014). The combi systems consisted of a water heater or boiler heating plant teamed with a hydronic air handler that included an air handler, water coil, and water pump to circulate water between the heating plant and coil. The combi water heater or boiler had a separate circuit for DHW. Past projects focused on laboratory testing, field characterization, and control optimization of combi systems. Laboratory testing was done to fully characterize and test combi system components; field testing was completed to characterize the installed performance of combi systems; and control methodologies were analyzed to understand the potential of controls to simplify installation and design and to improve system efficiency and occupant comfort. This past work was relied upon on to create this measure guideline.

  13. Measure Guideline: Combined Space and Water Heating Installation and Optimization

    Energy Technology Data Exchange (ETDEWEB)

    Schoenbauer, B. [Univ. of Minnesota, St. Paul, MN (United States). NorthernSTAR Building America Partnership; Bohac, D. [Univ. of Minnesota, St. Paul, MN (United States). NorthernSTAR Building America Partnership; Huelman, P. [Univ. of Minnesota, St. Paul, MN (United States). NorthernSTAR Building America Partnership

    2017-03-03

    Combined space and water heater (combi or combo) systems are defined by their dual functionality. Combi systems provide both space heating and water heating capabilities with a single heat source. This guideline will focus on the installation and operation of residential systems with forced air heating and domestic hot water (DHW) functionality. Past NorthernSTAR research has used a combi system to replace a natural gas forced air distribution system furnace and tank type water heater (Schoenbauer et al. 2012; Schoenbauer, Bohac, and McAlpine 2014). The combi systems consisted of a water heater or boiler heating plant teamed with a hydronic air handler that included an air handler, water coil, and water pump to circulate water between the heating plant and coil. The combi water heater or boiler had a separate circuit for DHW. Past projects focused on laboratory testing, field characterization, and control optimization of combi systems. Laboratory testing was done to fully characterize and test combi system components; field testing was completed to characterize the installed performance of combi systems; and control methodologies were analyzed to understand the potential of controls to simplify installation and design and to improve system efficiency and occupant comfort. This past work was relied upon on to create this measure guideline.

  14. Seasonal performance evaluation of electric air-to-water heat pump systems

    International Nuclear Information System (INIS)

    Dongellini, Matteo; Naldi, Claudia; Morini, Gian Luca

    2015-01-01

    A numerical model for the calculation of the seasonal performance of different kinds of electric air-to-water heat pumps is presented. The model is based on the procedure suggested by the European standard EN 14825 and the Italian standard UNI/TS 11300-4, which specify the guidelines for calculation of the seasonal performance of heat pumps during the heating season (SCOP), the cooling season (SEER) and for the production of domestic hot water. In order to consider the variation of outdoor conditions the developed model employs the bin-method. Different procedures are proposed in the paper for the analysis of the seasonal performance of mono-compressor, multi-compressor and variable speed compressor air-to-water heat pumps. The numerical results show the influence of the effective operating mode of the heat pumps on the SCOP value and put in evidence the impact of the design rules on the seasonal energy consumption of these devices. The study also highlights the importance of the correct sizing of the heat pump in order to obtain high seasonal efficiency and it shows that, for a fixed thermal load, inverter-driven and multi-compressor heat pumps have to be slightly oversized with respect to mono-compressor ones in order to obtain for the same building the highest SCOP values. - Highlights: • A model for the prediction of seasonal performance of HPs has been developed. • The model considers mono-compressor, multi-compressor and inverter-driven HPs. • The procedure takes into account HPs performances at partial load. • Optimization of heat pump sizing depending on its control system.

  15. System design package for SIMS prototype system 4, solar heating and domestic hot water

    Science.gov (United States)

    1978-01-01

    The system consisted of a modular designed prepackaged solar unit, containing solar collectors, a rock storage container, blowers, dampers, ducting, air-to-water heat exchanger, DHW preheat tank, piping, and system controls. The system was designed to be installed adjacent to a small single family dwelling. The description, performance specification, subsystem drawings, verification plan/procedure, and hazard analysis of the system were packaged for evaluation.

  16. Liquid heat capacity of the solvent system (piperazine + n-methyldiethanolamine + water)

    International Nuclear Information System (INIS)

    Chen, Y.-R.; Caparanga, Alvin R.; Soriano, Allan N.; Li, M.-H.

    2010-01-01

    A new set of values for the heat capacity of aqueous mixtures of piperazine (PZ) and n-methyldiethanolamine (MDEA) at different concentrations and temperatures are reported in this paper. The differential scanning calorimetry technique was used to measure the property over the range T = 303.2 K to T = 353.2 K for mixtures containing 0.60 to 0.90 mole fraction water with 15 different concentrations of the system (PZ + MDEA + H 2 O). Heat capacity for four concentrations of the binary system (PZ + MDEA) was also measured. A Redlich-Kister-type equation was adopted to estimate the excess molar heat capacity, which was used to predict the value of the molar heat capacity at a particular concentration and temperature, which would then be compared against the measured value. A total of 165 data points fit into the model resulted in a low overall average absolute deviation of 4.6% and 0.3% for the excess molar heat capacity and molar heat capacity, respectively. Thus, the results presented here are of acceptable accuracy for use in engineering process design.

  17. Design package for a complete residential solar space heating and hot water system

    Science.gov (United States)

    1978-01-01

    Information necessary to evaluate the design of a solar space heating and hot water system is reported. System performance specifications, the design data brochure, the system description, and other information pertaining to the design are included.

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

    International Nuclear Information System (INIS)

    Havelka, Z.; Petrovsky, I.

    1987-01-01

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

  19. Performance of a Solar Heating System with Photovoltaic Thermal Hybrid Collectors and Heat Pump

    DEFF Research Database (Denmark)

    Dannemand, Mark; Furbo, Simon; Perers, Bengt

    2017-01-01

    . When the solar collectors are unable to supply the heat demand an auxiliary heat source is used. Heat pumps can generate this heat. Liquid/water heat pumps have better performance than air/water heat pumps in cold climates but requires installation of a tubing system for the cold side of the heat pump....... The tubes are typically placed in the ground, requires a significant land area and increase the installation cost. A new system design of a solar heating system with two storage tanks and a liquid/water heat pump is presented. The system consists of PVT collectors that generate both heat and electricity......The energy consumption in buildings accounts for a large part of the World’s CO2 emissions. Much energy is used for appliances, domestic hot water preparation and space heating. In solar heating systems, heat is captured by solar collectors when the sun is shining and used for heating purposes...

  20. Solar heating and domestic hot water system installed at Kansas City, Fire Stations, Kansas City, Missouri

    Science.gov (United States)

    1980-01-01

    The solar system was designed to provide 47 percent of the space heating, 8,800 square feet area and 75 percent of the domestic hot water (DHW) load. The solar system consists of 2,808 square feet of Solaron, model 2001, air, flat plate collector subsystem, a concrete box storage subsystem which contains 1,428 cubic feet of 0.5 inch diameter pebbles weighing 71.5 tons, a DHW preheat tank, blowers, pumps, heat exchangers, air ducting, controls and associated plumbing. Two 120 gallon electric DHW heaters supply domestic hot water which is preheated by the solar system. Auxiliary space heating is provided by three electric heat pumps with electric resistance heaters and four 30 kilowatt electric unit heaters. There are six modes of system operation.

  1. Solar heating and domestic hot water system installed at Kansas City, Fire Stations, Kansas City, Missouri

    Science.gov (United States)

    1980-07-01

    The solar system was designed to provide 47 percent of the space heating, 8,800 square feet area and 75 percent of the domestic hot water (DHW) load. The solar system consists of 2,808 square feet of Solaron, model 2001, air, flat plate collector subsystem, a concrete box storage subsystem which contains 1,428 cubic feet of 0.5 inch diameter pebbles weighing 71.5 tons, a DHW preheat tank, blowers, pumps, heat exchangers, air ducting, controls and associated plumbing. Two 120 gallon electric DHW heaters supply domestic hot water which is preheated by the solar system. Auxiliary space heating is provided by three electric heat pumps with electric resistance heaters and four 30 kilowatt electric unit heaters. There are six modes of system operation.

  2. After-heat removal system

    International Nuclear Information System (INIS)

    Yamamoto, Michiyoshi; Mitani, Shinji.

    1982-01-01

    Purpose: To prevent contamination of suppression pool water and intrusion of corrosion products into a nuclear reactor. Constitution: Upon stop of an after-heat removing system, reactor water contained in pipelines is drained out to a radioactive wastes processing facility at the time the cooling operation mode has been completed. At the same time, water is injected from a pure water supply system to the after-heat removing system to discharge corrosion product and activated materials while cleaning the inside of the pipelines. Then, pure water is held in the pipelines and it is discharged again and replaced with pure water before entering the cooling mode operation. Thereafter, the cooling mode operation upon reactor shutdown is performed. (Yoshino, Y.)

  3. Solar Heating System with Building-Integrated Heat Storage

    DEFF Research Database (Denmark)

    Heller, Alfred

    1996-01-01

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

  4. Research of the heat exchanging processes running in the heating and hot water supply loops of the coil heat exchangers

    Directory of Open Access Journals (Sweden)

    Ірина Геннадіївна Шитікова

    2016-11-01

    Full Text Available The fuel-energy complex research has made it possible to disclose a huge power-saving potential in the municipal heat-and-power engineering. Power-and-resource-saving units and systems are becoming extremely urgent because of the power engineering crisis expansion. The self-adjusting heat supply system from the individual heating points with the heat-accumulating units and coil heat exchangers for independent heating and water supply systems has been examined. Coil heat exchangers are used in municipal heating for heat transfer (e.g. geothermal waters for the independent mains of the heating and hot water supply systems. The heat engineering calculation of the heating and accumulating unit with the coil heat exchanger for independent heat supply systems from individual heater was performed and experimental data were received at the experimental industrial unit under the laboratory conditions. The peculiarities of the flows in the intertubular space, their influence on the heat exchange and temperatures of the first and intermediate mains have been shown. It is important to know the processes running inside the apparatus to be able to improve the technical characteristics of the three-loop coil heat exchanger. The task solution will make it possible to save the materials consumption for the three-loop coil heat exchangers in the future

  5. Energy performance of air-to-water and water-to-water heat pumps in hotel applications

    International Nuclear Information System (INIS)

    Lam, Joseph C.; Chan, Wilco W.

    2003-01-01

    We present work on measurement of the energy performance of heat pumps for hotel operations in subtropical climates. Two city hotels in Hong Kong were investigated. The first case was an application of an air-to-water heat pump to provide heating for an outdoor swimming pool during the heating season. The second case was the installation of three water-to-water heat pumps to complement an existing boiler system for hot water supply. The heating energy output and corresponding electricity use were measured. The heat pump energy efficiency was evaluated in terms of the coefficient of performance (COP), defined as the heating energy output to the electrical energy use. The air-to-water heat pump provided 49.1 MW h heating while consuming 24.6 MW h electricity during the 6((1)/(2))-month heating season from mid-October to April. For the water-to-water heat pumps, the estimated annual heating output and the electricity use were 952 and 544 MW h, respectively. It was found that the heat pumps generally operated in a COP range of 1.5-2.4, and the payback period was about two years, which was considered financially attractive

  6. Annual analysis of heat pipe PV/T systems for domestic hot water and electricity production

    International Nuclear Information System (INIS)

    Pei Gang; Fu Huide; Ji Jie; Chow Tintai; Zhang Tao

    2012-01-01

    Highlights: ► A novel heat pipe photovoltaic/thermal system with freeze protection was proposed. ► A detailed annual simulation model for the HP-PV/T system was presented. ► Annual performance of HP-PV/T was predicted and analyzed under different condition. - Abstract: Heat-pipe photovoltaic/thermal (HP-PV/T) systems can simultaneously provide electrical and thermal energy. Compared with traditional water-type photovoltaic/thermal systems, HP-PV/T systems can be used in cold regions without being frozen with the aid of a carefully selected heat-pipe working fluid. The current research presents a detailed simulation model of the HP-PV/T system. Using this model, the annual electrical and thermal behavior of the HP-PV/T system used in three typical climate areas of China, namely, Hong Kong, Lhasa, and Beijing, are predicted and analyzed. Two HP-PV/T systems, with and without auxiliary heating equipment, are studied annually under four different kinds of hot-water load per unit collecting area (64.5, 77.4, 90.3, and 103.2 kg/m 2 ).

  7. System Design Package for SIMS Prototype System 3, Solar Heating and Domestic Hot Water

    Science.gov (United States)

    1978-01-01

    A collation of documents and drawings are presented that describe a prototype solar heating and hot water system using liquid flat plate collectors and a gas or electric furnace energy subsystem. The system was designed for installation into a single-family dwelling. The description, performance specification, subsystem drawings, verification plan/procedure, and hazard analysis of the system are packaged for evaluation of the system with information sufficient to assemble a similar system.

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

    DEFF Research Database (Denmark)

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

    2017-01-01

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

  9. Competence in water-borne heating systems in buildings; Kompetanse innen vannbaarene varmesystemer i bygg

    Energy Technology Data Exchange (ETDEWEB)

    Jarstein, Stig; Palm, Linn Therese; Naess, Bente Haukland; Nossum, Aase; Johnsen, Morten

    2009-01-15

    Trade participants in water-borne heating systems in buildings has experienced mistakes in all phases and of all participants of a project. When water-borne heating system functions, there is almost no follow up. This report is based on a qualitative survey where a several central participants, who on a daily basis are involved in projects with water-borne heating systems, are interviewed or have participated in focus group meetings. Following points illustrate experiences made by the operators in occasions where competence in trade is insufficiencies and mistakes occur: - Property developer lacks ordering competence and has problems in ordering quality. Consultant submit services of minor quality. Performance is of another quality than the supplier. Administration / maintenance lacks competence in how to run the system and without introduction and training in the heating system they take over a system that is over dimensioned and hard to regulate. The trade as a whole knows all the challenges, but the participants gives mainly the impression that the fault is lac of competence for all the other participants - not them self. This report points out measures and Enova can support competence improving measures which on long term will improve the quality from the participants. The trade is recommended to look into project execution, how competence is involved at the right moment, improving of control and documentation routines and at termination / hand over. (AG).14 refs., 14 figs., 2 tabs

  10. Heat exchangers in heavy water reactor systems

    International Nuclear Information System (INIS)

    Mehta, S.K.

    1988-01-01

    Important features of some major heat exchange components of pressurized heavy water reactors and DHRUVA research reactor are presented. Design considerations and nuclear service classifications are discussed

  11. Mathematical model for calculation of the heat-hydraulic modes of heating points of heat-supplying systems

    Science.gov (United States)

    Shalaginova, Z. I.

    2016-03-01

    The mathematical model and calculation method of the thermal-hydraulic modes of heat points, based on the theory of hydraulic circuits, being developed at the Melentiev Energy Systems Institute are presented. The redundant circuit of the heat point was developed, in which all possible connecting circuits (CC) of the heat engineering equipment and the places of possible installation of control valve were inserted. It allows simulating the operating modes both at central heat points (CHP) and individual heat points (IHP). The configuration of the desired circuit is carried out automatically by removing the unnecessary links. The following circuits connecting the heating systems (HS) are considered: the dependent circuit (direct and through mixing elevator) and independent one (through the heater). The following connecting circuits of the load of hot water supply (HWS) were considered: open CC (direct water pumping from pipelines of heat networks) and a closed CC with connecting the HWS heaters on single-level (serial and parallel) and two-level (sequential and combined) circuits. The following connecting circuits of the ventilation systems (VS) were also considered: dependent circuit and independent one through a common heat exchanger with HS load. In the heat points, water temperature regulators for the hot water supply and ventilation and flow regulators for the heating system, as well as to the inlet as a whole, are possible. According to the accepted decomposition, the model of the heat point is an integral part of the overall heat-hydraulic model of the heat-supplying system having intermediate control stages (CHP and IHP), which allows to consider the operating modes of the heat networks of different levels connected with each other through CHP as well as connected through IHP of consumers with various connecting circuits of local systems of heat consumption: heating, ventilation and hot water supply. The model is implemented in the Angara data

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

    Directory of Open Access Journals (Sweden)

    Y. Bai

    2012-01-01

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

  13. Solar Energy for Space Heating & Hot Water.

    Science.gov (United States)

    Energy Research and Development Administration, Washington, DC. Div. of Solar Energy.

    This pamphlet reviews the direct transfer of solar energy into heat, particularly for the purpose of providing space and hot water heating needs. Owners of buildings and homes are provided with a basic understanding of solar heating and hot water systems: what they are, how they perform, the energy savings possible, and the cost factors involved.…

  14. Conventional heating systems is heating with geothermal water, v. 15(60)

    International Nuclear Information System (INIS)

    Hadzhimishev, Dimitar; Gashteovski, Ljupcho; Shami, Jotso

    2007-01-01

    The Geothermal Energy (GE) is a new renewable energy source with many advantages and specifics. Present mainly application of GE is in agriculture. In Geothermal System Kochani the GE uses for district heating and industrial uses also. There are many problems to solve before using the geothermal energy for district heating: direct application feasibility for heating rooms and industrial using existing heating installation system (90/70°C); the level of heating needs covering without installation reconstruction; techno-economical justification of this reconstruction ; covering of pike heating needs. The answers of these enigmas you have in this written effort. The results were practically justified in about ten object in Kochani. (Author)

  15. Conventional heating systems is heating with geothermal water, v. 15(59)

    International Nuclear Information System (INIS)

    Hadzhimishev, Dimitar; Gashteovski, Ljupcho; Shami, Jotso

    2007-01-01

    The Geothermal Energy (GE) is a new renewable energy source with many advantages and specifics. Present mainly application of GE is in agriculture. In Geothermal System Kochani the GE uses for district heating and industrial uses also. There are many problems to solve before using the geothermal energy for district heating: direct application feasibility for heating rooms and industrial using existing heating installation system (90/70°C); the level of heating needs covering without installation reconstruction; techno-economical justification of this reconstruction ; covering of pike heating needs. The answers of these enigmas you have in this written effort. The results were practically justified in about ten object in Kochani. (Author)

  16. Heat pipes and heat pipe exchangers for heat recovery systems

    Energy Technology Data Exchange (ETDEWEB)

    Vasiliev, L L; Grakovich, L P; Kiselev, V G; Kurustalev, D K; Matveev, Yu

    1984-01-01

    Heat pipes and heat pipe exchangers are of great importance in power engineering as a means of recovering waste heat of industrial enterprises, solar energy, geothermal waters and deep soil. Heat pipes are highly effective heat transfer units for transferring thermal energy over large distance (tens of meters) with low temperature drops. Their heat transfer characteristics and reliable working for more than 10-15 yr permit the design of new systems with higher heat engineering parameters.

  17. Low Temperature District Heating Consumer Unit with Micro Heat Pump for Domestic Hot Water Preparation

    DEFF Research Database (Denmark)

    Zvingilaite, Erika; Ommen, Torben Schmidt; Elmegaard, Brian

    2012-01-01

    In this paper we present and analyse the feasibility of a district heating (DH) consumer unit with micro heat pump for domestic hot water (DHW) preparation in a low temperature (40 °C) DH network. We propose a micro booster heat pump of high efficiency (COP equal to 5,3) in a consumer DH unit...... in order to boost the temperature of the district heating water for heating the DHW. The paper presents the main designs of the suggested system and different alternative micro booster heat pump concepts. Energy efficiency and thermodynamic performance of these concepts are calculated and compared....... The results show that the proposed system has the highest efficiency. Furthermore, we compare thermodynamic and economic performance of the suggested heat pump-based concept with different solutions, using electric water heater. The micro booster heat pump system has the highest annualised investment (390 EUR...

  18. Verification test report on a solar heating and hot water system

    Science.gov (United States)

    1978-01-01

    Information is provided on the development, qualification and acceptance verification of commercial solar heating and hot water systems and components. The verification includes the performances, the efficiences and the various methods used, such as similarity, analysis, inspection, test, etc., that are applicable to satisfying the verification requirements.

  19. Study of an innovative ejector heat pump-boosted district heating system

    International Nuclear Information System (INIS)

    Zhang, Bo; Wang, Yuanchao; Kang, Lisha; Lv, Jinsheng

    2013-01-01

    An Ejector heat pump-boosted District Heating (EDH) system is proposed to improve the heating capacity of existing district heating systems with Combined Heat and Power (CHP). In the EDH, two ejector heat pumps are installed: a primary heat pump (HP 1 ) at the heating station and a secondary heat pump (HP 2 ) at the heating substation. With the EDH, the low-grade waste heat from circulating cooling water in the CHP is recycled and the temperature difference between the water supply and the return of the primary heating network is increased. A thermodynamic model was provided. An experimental study was carried out for both HP 1 and HP 2 to verify the predicting performance. The results show that the COP of HP 1 can reach 1.5–1.9, and the return water temperature of the primary heating network could be decreased to 35 °C with HP 2 . A typical case study for the EDH was analyzed. -- Highlights: • An ejector heat pump-boosted district heating (EDH) is proposed. • The 1st ejector heat pump in EDH recycles heat from cooling water of the CHP. • The 2nd ejector heat pump in EDH boosts the thermal energy utilization of the primary heating network. • Modeling and experimental studies are presented

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

    International Nuclear Information System (INIS)

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

    2014-01-01

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

  1. Solar heating, cooling, and hot water systems installed at Richland, Washington

    Science.gov (United States)

    1979-01-01

    The project described is part of the U. S. Department of Energy's solar demonstration program, and became operational in April 1978. The solar system uses 6,000 square feet of flat-plate liquid collectors in a closed loop to deliver solar energy through a liquid-liquid heat exchanger to the building heat-pump duct work or 9,000-gallon thermal energy storage tank. A 25-ton Arkla solar-driven absorption chiller provides the cooling, in conjunction with a 2,000 gallon chilled water storage tank and reflective ponds on three sides of the building surplus heat. A near-by building is essentially identical except for having conventional heat-pump heating and cooling, and can serve as an experimental control. An on-going public relations program was provided from the beginning of the program, and resulted in numerous visitors and tour groups.

  2. Boise geothermal district heating system

    Energy Technology Data Exchange (ETDEWEB)

    Hanson, P.J.

    1985-10-01

    This document describes the Boise geothermal district heating project from preliminary feasibility studies completed in 1979 to a fully operational system by 1983. The report includes information about the two local governments that participated in the project - the City of Boise, Idaho and the Boise Warm Springs Water District. It also discusses the federal funding sources; the financial studies; the feasibility studies conducted; the general system planning and design; design of detailed system components; the legal issues involved in production; geological analysis of the resource area; distribution and disposal; the program to market system services; and the methods of retrofitting buildings to use geothermal hot water for space heating. Technically this report describes the Boise City district heating system based on 170/sup 0/F water, a 4000 gpm production system, a 41,000 foot pipeline system, and system economies. Comparable data are also provided for the Boise Warm Springs Water District. 62 figs., 31 tabs.

  3. Economics of residential solar hot water heating systems in Malaysia

    International Nuclear Information System (INIS)

    Abdulmula, Ahmed Mohamed Omer; Sopian, Kamaruzzaman; Haj Othman, Mohd Yosof

    2006-01-01

    Malaysia has favorable climatic conditions for the development of solar energy due to the abundant sunshine and is considered good for harnessing energy from the sun. This is because solar hot water can represent the large energy consumer in Malaysian households but, because of the high initial cost of Solar Water Heating Systems (SWHSs) and easily to install and relatively inexpensive to purchase electric water heaters, many Malyaysian families are still using Electric Water Heaters to hot their water needs. This paper is presented the comparing of techno-economic feasibility of some models of SWHS from Malaysian's market with the Electric Water Heaters )EWH) by study the annual cost of operation for both systems. The result shows that the annual cost of the electrical water heater becomes greater than than the annual cost of the SWHS for all models in long-team run so it is advantageous for the family to use the solar water heater, at least after 4 years. In addition with installation SWHS the families can get long-term economical benefits, environment friendly and also can doing its part to reduce this country's dependence on foreign oil that is price increase day after day.(Author)

  4. Chemical heat pump and chemical energy storage system

    Science.gov (United States)

    Clark, Edward C.; Huxtable, Douglas D.

    1985-08-06

    A chemical heat pump and storage system employs sulfuric acid and water. In one form, the system includes a generator and condenser, an evaporator and absorber, aqueous acid solution storage and water storage. During a charging cycle, heat is provided to the generator from a heat source to concentrate the acid solution while heat is removed from the condenser to condense the water vapor produced in the generator. Water is then stored in the storage tank. Heat is thus stored in the form of chemical energy in the concentrated acid. The heat removed from the water vapor can be supplied to a heat load of proper temperature or can be rejected. During a discharge cycle, water in the evaporator is supplied with heat to generate water vapor, which is transmitted to the absorber where it is condensed and absorbed into the concentrated acid. Both heats of dilution and condensation of water are removed from the thus diluted acid. During the discharge cycle the system functions as a heat pump in which heat is added to the system at a low temperature and removed from the system at a high temperature. The diluted acid is stored in an acid storage tank or is routed directly to the generator for reconcentration. The generator, condenser, evaporator, and absorber all are operated under pressure conditions specified by the desired temperature levels for a given application. The storage tanks, however, can be maintained at or near ambient pressure conditions. In another form, the heat pump system is employed to provide usable heat from waste process heat by upgrading the temperature of the waste heat.

  5. Consumer impacts on dividends from solar water heating

    Energy Technology Data Exchange (ETDEWEB)

    Hill, F.; Levermore, G. [University of Manchester, Manchester (United Kingdom); Lynch, H. [Centre for Alternative Technology, Machynlleth, University of East London, London (United Kingdom)

    2011-01-15

    Common domestic solar water heating system usage patterns were investigated by a survey of 55 installations. These usage patterns were modelled by simulation based on the actual occupants' use of boiler or other auxiliary heating control strategies. These strategies were not optimal, as often assumed. The effectiveness of the technology was found to be highly sensitive to the time settings used for auxiliary water heating, and the 65% of solar householders using their boilers in the mornings were found to be forgoing 75% of their potential savings. Additionally, 92% of consumers were found to be small households, whose potential savings were only 23% of those of larger households, which use more hot water. Overall the majority (at least 60%) of the systems surveyed were found to be achieving no more than 6% of their potential savings. Incorporating consideration of Legionella issues, results indicate that if solar thermal technology is to deliver its potential to CO2 reduction targets: solar householders must avoid any use of their auxiliary water heating systems before the end of the main warmth of the day, grants for solar technology should be focused on households with higher hot water demands, and particularly on those that are dependent on electricity for water heating, health and safety requirements for hot water storage must be reviewed and, if possible, required temperatures should be set at a lower level, so that carbon savings from solar water heating may be optimized.

  6. 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.

  7. Heat-pump-centered integrated community energy systems

    Energy Technology Data Exchange (ETDEWEB)

    Schaetzle, W.J.; Brett, C.E.; Seppanen, M.S.

    1979-12-01

    The heat-pump-centered integrated community energy system (HP-ICES) supplies district heating and cooling using heat pumps and a thermal energy storage system which is provided by nature in underground porous formations filled with water, i.e., aquifers. The energy is transported by a two-pipe system, one for warm water and one for cool water, between the aquifers and the controlled environments. Each energy module contains the controlled environments, an aquifer, wells for access to the aquifer, the two pipe water distribution system and water source heat pumps. The heat pumps upgrade the energy in the distribution system for use in the controlled environments. Economically, the system shows improvement on both energy usage and capital costs. The system saves over 60% of the energy required for resistance heating; saves over 30% of the energy required for most air-source heat pumps and saves over 60% of the energy required for gas, coal, or oil heating, when comparing to energy input required at the power plant for heat pump usage. The proposed system has been analyzed as demonstration projects for a downtown portion of Louisville, Kentucky, and a section of Fort Rucker, Alabama. The downtown Louisville demonstration project is tied directly to major buildings while the Fort Rucker demonstration project is tied to a dispersed subdivision of homes. The Louisville project shows a payback of approximately 3 y, while Fort Rucker is approximately 30 y. The primary difference is that at Fort Rucker new heat pumps are charged to the system. In Louisville, either new construction requiring heating and cooling systems or existing chillers are utilized. (LCL)

  8. Field Surveys of Non-Residential Solar Water Heating Systems in Taiwan

    Directory of Open Access Journals (Sweden)

    Kung-Ming Chung

    2012-02-01

    Full Text Available To develop indigenous alternative and renewable energy resources, long-term subsidy programs (1986–1991 and 2000–present for solar water heaters have been enforced in Taiwan. By the end of 2010, the total installed area of solar collectors had exceeded 2 million square meters. However, over 98% of solar water heaters were used in residential systems for hot water production, with the areas of installed solar collector being less than 10 square meters. There were only 98 systems with area of solar collectors installed exceeding 100 square meters put into operation from 2001 to 2010. These systems were mainly installed for water heating in dormitories, swimming pools, restaurants, and manufacturing plants. In the present study, a comprehensive survey of these large-scale solar water heaters was conducted. The objectives of the survey were to assess the system performance and to collect feedback from individual users. It is found that lack of experience in system design and maintenance are the key factors affecting reliable operation of a system. Hourly, daily and long-term field measurements of a dormitory system were also examined to evaluate its thermal efficiencies. Results indicated that thermal efficiency of the system is associated with the daily solar radiation. Hot water use pattern and operation of auxiliary heater should be taken into account in system design.

  9. Prototype implementation and experimental analysis of water heating using recovered waste heat of chimneys

    Directory of Open Access Journals (Sweden)

    Mahmoud Khaled

    2015-03-01

    Full Text Available This work discusses a waste heat recovery system (WHRS applied to chimneys for heating water in residential buildings. A prototype illustrating the suggested system is implemented and tested. Different waste heat scenarios by varying the quantity of burned firewood (heat input are experimented. The temperature at different parts of the WHRS and the gas flow rates of the exhaust pipes are measured. Measurements showed that the temperature of 95 L tank of water can be increased by 68 °C within one hour. Obtained results show that the convection and radiation exchanges at the bottom surface of the tank have a considerable impact on the total heat transfer rate of the water (as high as 70%.

  10. An Experiment on Heat Recovery Performance Improvements in Well-Water Heat-Pump Systems for a Traditional Japanese House

    Directory of Open Access Journals (Sweden)

    Chiemi Iba

    2018-04-01

    Full Text Available Concerns about resource depletion have prompted several countries to promote the usage of renewable energy, such as underground heat. In Japan, underground heat-pump technology has begun to be utilized in large-scale office buildings; however, several economic problems are observed to still exist, such as high initial costs that include drilling requirements. Further, most of the traditional dwellings “Kyo-machiya” in Kyoto, Japan have a shallow well. This study intends to propose an effective ground-source heat-pump system using the well water from a “Kyo-machiya” home that does not contain any drilling works. In previous research, it was depicted that the well-water temperature decreases as the heat pump (HP is operated and that the heat extraction efficiency steadily becomes lower. In this study, an experiment is conducted to improve efficiency using a drainage pump. Based on the experimental results, the effect of efficiency improvement and the increase in the electric power consumption of the drainage pump are examined. It is indicated that short-time drainage could help to improve efficiency without consuming excessive energy. Thus, continuous use of the heat pump becomes possible.

  11. Fuel cell heat utilization system; Nenryo denchi netsuriyo sochi

    Energy Technology Data Exchange (ETDEWEB)

    Urata, T. [Tokyo (Japan); Omura, T. [Tokyo (Japan)

    1995-07-04

    In the conventional fuel cell heat utilization system, the waste heat is recovered to be utilized by either the waste heat recovery heat exchanger or the waste heat recovery steam. In the employment of the waste heat recovery heat exchanger system, however, the utility value is decreased when the temperature of the waste heat is lowered. Contrarily, in the employment of the waste heat recovery steam system, the supplementary water requirement is increased corresponding to the amount of waste heat recovery steam, resulting in the cost increase for water treatment. This invention solves the problem. In the invented fuel cell heat utilization system, a pressurized water from the steam separator is introduced into the second circuit to utilize directly the heat in the heat utilization system without employing the heat exchanger. If a blowdown valve is installed between the second circuit heat utilization system and the steam separator, the heat loss due to the blowdown can be reduced, since the low temperature water is blown down after being utilized in the heat utilization system. 4 figs.

  12. In-Situ Measurements of the Performance of Thermosyphon Solar Water Heating Systems in Libya

    International Nuclear Information System (INIS)

    Abdunnabi, M. I. R.; Loveday, D. L.

    2014-01-01

    This paper reports on a project carried out by the Centre for Solar Energy Research and Studies (CSERS) to familiarize Libyan people with solar water heating technologies. Around 100 solar water heaters have been installed in the domestic sector and selected systems were equipped with monitoring instruments required to evaluate thermal performance. The paper presents the results of data collected over a one year period from a system installed in a family residence situated in a village located 90 km south of Tripoli (Libyan capital). The results showed that the system solar fraction was 55.8% of the average amount of daily hot water withdrawn (144 liters) at an average withdrawal temperature of 46.6 °. The total energy withdrawn during the whole year was 1557 kWl1. It is concluded that such a system is not adequate in terms of cost effectiveness for the current installed situation. It is recommended that the annual solar fraction for any solar water heating system should be over 70° in order to achieve cost—effectiveness and to help wide spread take—up of this technology.(author)

  13. Solar heating and hot water system installed at James Hurst Elementary School, Portsmouth, Virginia

    Science.gov (United States)

    1981-01-01

    Solar heating and a hot water system installed in an elementary school in Portsmouth, Virginia are examined. The building is zoned into four heating/cooling areas. Each area is equipped with an air handling unit that is monitored and controlled by central control and monitoring system. The solar system for the building uses a collector area of 3,630 sq. ft. of flat plate liquid collectors, and a 6,000 gallon storage tank. System descriptions, maintenance reports, detailed component specifications, and design drawings to evaluate this solar system are reported.

  14. Federal technology alert. Parabolic-trough solar water heating

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-04-01

    Parabolic-trough solar water heating is a well-proven renewable energy technology with considerable potential for application at Federal facilities. For the US, parabolic-trough water-heating systems are most cost effective in the Southwest where direct solar radiation is high. Jails, hospitals, barracks, and other facilities that consistently use large volumes of hot water are particularly good candidates, as are facilities with central plants for district heating. As with any renewable energy or energy efficiency technology requiring significant initial capital investment, the primary condition that will make a parabolic-trough system economically viable is if it is replacing expensive conventional water heating. In combination with absorption cooling systems, parabolic-trough collectors can also be used for air-conditioning. Industrial Solar Technology (IST) of Golden, Colorado, is the sole current manufacturer of parabolic-trough solar water heating systems. IST has an Indefinite Delivery/Indefinite Quantity (IDIQ) contract with the Federal Energy Management Program (FEMP) of the US Department of Energy (DOE) to finance and install parabolic-trough solar water heating on an Energy Savings Performance Contract (ESPC) basis for any Federal facility that requests it and for which it proves viable. For an ESPC project, the facility does not pay for design, capital equipment, or installation. Instead, it pays only for guaranteed energy savings. Preparing and implementing delivery or task orders against the IDIQ is much simpler than the standard procurement process. This Federal Technology Alert (FTA) of the New Technology Demonstration Program is one of a series of guides to renewable energy and new energy-efficient technologies.

  15. Development of two-stage compression heat pump for hot water supply in commercial use. Establishment of design method for water and air heat source system; Gyomuyo nidan asshukushiki kyuto heat pump no kaihatsu. Suinetguen oyobi kuki netsugen sytem no sekkei hoho no kakuritsu

    Energy Technology Data Exchange (ETDEWEB)

    Hasegawa, H; Hashimoto, K; Saikawa, M; Iwatsubo, T; Mimaki, T [Central Research Institute of Electric Power Industry, Tokyo (Japan)

    1996-07-01

    The two-stage compression cascade heating heat pump cycle was devised for hot water supply in business use such as hotel and store use which allows hot water supply less in primary energy consumption than gas boilers, and higher in temperature than conventional heat pumps. This cycle heats water in cascade manner by two-stage compression using two compressors in both low- and high-stage refrigerant circuits, and two condensers different in condensation temperature (intermediate heat exchanger and condenser) to achieve higher hot water temperature and higher COP. For cost reduction, the new system design method was established which is possible to cope with conventional compressors such as screw and scroll ones with different theoretical suction volume for every one. System design parameters such as thermal output and COP of hot water supply were largely affected by theoretical suction volume ratio of low- and high-stage compressors dependent on combination of the compressors, and refrigerant condensing temperature in an intermediate heat exchanger as proper parameter. 4 refs., 17 figs., 13 tabs.

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

    International Nuclear Information System (INIS)

    Dawoud, Belal

    2014-01-01

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

  17. Solar heating still in the early stages. Changes for hot water production - VDI meeting 'Efficient heating systems'

    Energy Technology Data Exchange (ETDEWEB)

    Goehringer, P

    1976-10-01

    More and more realism replaces the initial euphoria concerning the discussion on solar heating. Not only the possibilities are considered these days, but also the limits of this still controversial way of heating. This impression was deepened by a meeting of the VDI-Gesellschaft Technische Gebaeudeausruestung (Society for the technical equipment of buildings) held in Bonn. The heating of water with solar energy during the summer is viewed optimistically by the experts - as far as space heating is concerned, the sun collector is conceded only a very modest position in Central Europe within integrated heating systems. It is true that solar technology in the USA is already very sophisticated and economically feasible in many cases; however, techniques cannot be adopted unconditionally for Europe, as the average values of global solar radiation are much lower here. Thus, different technologies will be required.

  18. Thermodynamic analysis and optimization of an ammonia-water power system with LNG (liquefied natural gas) as its heat sink

    International Nuclear Information System (INIS)

    Wang, Jiangfeng; Yan, Zhequan; Wang, Man; Dai, Yiping

    2013-01-01

    Due to a good behavior of ammonia-water during the two-phase heat addition process and the liquefied natural gas with great cold energy, an ammonia-water power system with LNG as its heat sink is proposed to utilize the low grade waste heat. Based on the thermodynamic mathematical models, the effects of key thermodynamic design parameters, including turbine inlet pressure, turbine inlet temperature, ammonia mass fraction, pinch temperature difference and approach temperature difference in the heat recovery vapor generator, on the system performance are examined from the view of both thermodynamics and economics. To obtain the optimum performance, multi-objective optimization is conducted to find the best thermodynamic design parameters from both thermodynamic and economic aspects using NSGA-II (Non-dominated sorting genetic algorithm-II). The exergy efficiency, total heat transfer capability and turbine size parameter are selected as three objective functions to maximize the exergy efficiency, and minimize the total heat transfer capability and turbine size parameter under the given waste heat conditions. The results show that turbine inlet pressure, turbine inlet temperature, ammonia mass fraction, pinch temperature difference and approach temperature difference have significant effects on the system performance. By multi-objective optimization, the Pareto frontier solution for the ammonia-water power system is obtained. - Highlights: ► An ammonia-water power system with LNG as its heat sink is proposed. ► The effects of key parameters on the system performance are examined. ► Multi-objective optimization is conducted to obtain optimum system performance

  19. A heat pipe solar collector system for winter heating in Zhengzhou city, China

    Directory of Open Access Journals (Sweden)

    Zheng Hui-Fan

    2017-01-01

    Full Text Available A heat pipe solar collector system for winter heating is investigated both experimentally and theoretically. The hourly heat collecting capacity, water temperature and contribution rate of solar collector system based on Zhengzhou city typical sunshine are calculated. The study reveals that the heat collecting capacity and water temperature increases initially and then decreases, and the solar collector system can provide from 40% to 78% heating load for a 200 m2 villa with in Zhengzhou city from November to March.

  20. Water systems

    International Nuclear Information System (INIS)

    Riess, R.

    1980-01-01

    The present paper describes the coolant chemistry and its consequences for 1300 MWsub(e) KWU PWR plants. Some selected systems, i.e. primary heat transport system, steam water cycle and cooling water arrangements, are chosen for this description. Various aspects of coolant chemistry regarding general corrosion, selective types of corrosion and deposits on heat transfer surfaces have been discussed. The water supply systems necessary to fulfill the requirements of the coolant chemistry are discussed as well. It has been concluded that a good operating performance can only be achieved when - beside other factors - the water chemistry has been given sufficient consideration. (orig./RW)

  1. Water systems

    International Nuclear Information System (INIS)

    Riess, R.

    1981-01-01

    The present paper describes the coolant chemistry and its consequences for 1300 MWsub(e) KWU PWR plants. Some selected systems, i.e. primary heat transport system, steam water cycle and cooling water arrangements, are chosen for this description. Various aspects of coolant chemistry regarding general corrosion, selective types of corrosion and deposits on heat transfer surface have been discussed. The water supply systems necessary to fulfill the requirements of the coolant chemistry are discussed as well. It has been concluded that a good operating performance can only be achieved when - beside other factors - the water chemistry has been given sufficient consideration. (orig./RW)

  2. Aging assessment of Residual Heat Removal systems in Boiling Water Reactors

    International Nuclear Information System (INIS)

    Lofaro, R.J.; Aggarwal, S.

    1992-01-01

    The effects of aging on Residual Heat Removal systems in Boiling Water Reactors have been studied as part of the Nuclear Plant Aging Research Program. The aging phenomena has been characterized by analyzing operating experience from various national data bases. In addition, actual plant data was obtained to supplement and validate the data base findings

  3. Outdoor test method to determine the thermal behavior of solar domestic water heating systems

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Valladares, O.; Pilatowsky, I. [Centro de Investigacion en Energia, Universidad Nacional Autonoma de Mexico, Privada Xochicalco, s/n, Colonia Centro, 62580 Temixco, Morelos (Mexico); Ruiz, V. [Escuela Tecnica Superior de Ingenieros, Universidad de Sevilla, Camino de los Descubrimientos, s/n, Isla de la Cartuja, 41092 Sevilla, Espana (Spain)

    2008-07-15

    The dynamics of the market, the generation of new promotion programs, fiscal incentives and many other factors are to be considered for the massive application of solar domestic water heating systems (SDWHS) mainly of the compact thermosiphon type, makes it necessary to choose simple and inexpensive procedure tests that permit to know their characteristic thermal behaviors without an official standard being necessary. Moreover, it allows the comparison among systems and offers enough and reliable information to consumers and manufacturers. In most developing countries, an official national standard for SDWHS is not available, therefore it is necessary to adopt an international test procedure in which the cost and time of implementation is very important. In this work, a simple and inexpensive test method to determine the thermal behavior of SDWHS is proposed. Even though these procedure tests do not have an official standard structure they permit, by comparing different solar systems under identical solar, ambient, and initial conditions, the experimental determination of: (a) the maximum available volume of water for solar heating; (b) water temperature increment and available thermal energy at the end of the day; (c) temperature profiles (stratification) and the average temperature in the storage tank after it is homogenized; (d) the average global thermal efficiency; (e) water temperature decrement and energy lost overnight; and (f) the relationship between hot water volume and solar collector area as function of the average heating temperature. An additional proposed test permits to know the heat losses caused by the reverse flow in the collector loop. These tests will be carried out independently of the configuration between the solar collector and the storage tank, the way the fluid circulates and the type of thermal exchange. The results of this procedure test can be very useful, firstly, for the local solar manufacturers' equipment in order to design

  4. Outdoor test method to determine the thermal behavior of solar domestic water heating systems

    International Nuclear Information System (INIS)

    Garcia-Valladares, O.; Pilatowsky, I.; Ruiz, V.

    2008-01-01

    The dynamics of the market, the generation of new promotion programs, fiscal incentives and many other factors are to be considered for the massive application of solar domestic water heating systems (SDWHS) mainly of the compact thermosiphon type, makes it necessary to choose simple and inexpensive procedure tests that permit to know their characteristic thermal behaviors without an official standard being necessary. Moreover, it allows the comparison among systems and offers enough and reliable information to consumers and manufacturers. In most developing countries, an official national standard for SDWHS is not available, therefore it is necessary to adopt an international test procedure in which the cost and time of implementation is very important. In this work, a simple and inexpensive test method to determine the thermal behavior of SDWHS is proposed. Even though these procedure tests do not have an official standard structure they permit, by comparing different solar systems under identical solar, ambient, and initial conditions, the experimental determination of: (a) the maximum available volume of water for solar heating; (b) water temperature increment and available thermal energy at the end of the day; (c) temperature profiles (stratification) and the average temperature in the storage tank after it is homogenized; (d) the average global thermal efficiency; (e) water temperature decrement and energy lost overnight; and (f) the relationship between hot water volume and solar collector area as function of the average heating temperature. An additional proposed test permits to know the heat losses caused by the reverse flow in the collector loop. These tests will be carried out independently of the configuration between the solar collector and the storage tank, the way the fluid circulates and the type of thermal exchange. The results of this procedure test can be very useful, firstly, for the local solar manufacturers' equipment in order to design and

  5. Laboratory Evaluation of Gas-Fired Tankless and Storage Water Heater Approaches to Combination Water and Space Heating

    Energy Technology Data Exchange (ETDEWEB)

    Kingston, T. [Gas Technology Inst., Des Plaines, IL (United States); Scott, S. [Gas Technology Inst., Des Plaines, IL (United States)

    2013-03-01

    Homebuilders are exploring more cost-effective combined space and water heating systems (combo systems) with major water heater manufacturers that are offering pre-engineered forced air space heating combo systems. In this project, unlike standardized tests, laboratory tests were conducted that subjected condensing tankless and storage water heater based combo systems to realistic, coincidental space and domestic hot water loads and found that the tankless combo system maintained more stable DHW and space heating temperatures than the storage combo system, among other key findings.

  6. Economic and safety aspects of using moderator heat for feed water heating in a nuclear power plant

    International Nuclear Information System (INIS)

    Patwegar, I.A.; Dutta, Anu; Chaki, S.K.; Venkat Raj, V.

    2002-01-01

    Full text: In the proposed advanced heavy water reactor (AHWR), coolant and moderator are separated by the coolant channel. The coolant absorbs most of the fission heat produced in the reactor core. However, the moderator absorbs about 5 to 6 % of the fission heat. In a reactor producing 750 MW(th) power, this moderator heat is about 40 MW. In the present Indian PHWR (pressurized heavy water reactor) systems, this moderator heat is lost to a sink through the moderator heat exchangers, which are cooled by process water. This paper presents the results of the steam cycle analysis carried out for AHWR using moderator heat exchangers as part of the feed heating system. The present study is an attempt to determine the gain in electrical output (MW) if moderator heat is utilized for feed water heating. The operational and safety aspects of using moderator heat are also discussed in the paper

  7. Improving the performance of district heating systems by utilization of local heat boosters

    DEFF Research Database (Denmark)

    Falcone, A.; Dominkovic, D. F.; Pedersen, A. S.

    was to evaluate the possibilities to lower the forward temperature of the heat supply in order to reduce the heat losses of the system. Booster heat pumps are introduced to increase the water temperature close to the final users. A Matlab model was developed to simulate the state of the case study DH network...... was set to minimize the system heat losses. * Corresponding author 0303-1 1 This goal was achieved by lowering the forward temperature to 40°C and relying on the installed heat pumps to boost the water temperature to the admissible value needed for the domestic hot water preparation. Depending......District Heating (DH) plays an important role into the Danish energy green transition towards the future sustainable energy systems. The new, 4 th generation district heating network, the so called Low Temperature District Heating (LTDH), tends to lower the supply temperature of the heat down to 40...

  8. Feasibility of active solar water heating systems with evacuated tube collector at different operational water temperatures

    International Nuclear Information System (INIS)

    Mazarrón, Fernando R.; Porras-Prieto, Carlos Javier; García, José Luis; Benavente, Rosa María

    2016-01-01

    Highlights: • Analysis of the feasibility of an active solar water-heating system. • Profitability decreases as the required water temperature increases. • The number of collectors that maximizes profitability depends on the required temperature. • Investment in a properly sized system generates savings between 23% and 15%. • Fuel consumption can be reduced by 70%. - Abstract: With rapid advancements in society, higher water temperatures are needed in a number of applications. The demand for hot water presents a great variability with water required at different temperatures. In this study, the design, installation, and evaluation of a solar water heating system with evacuated tube collector and active circulation has been carried out. The main objective is to analyze how the required tank water temperature affects the useful energy that the system is capable of delivering, and consequently its profitability. The results show how the energy that is collected and delivered to the tank decreases with increasing the required temperature due to a lower performance of the collector and losses in the pipes. The annual system efficiency reaches average values of 66%, 64%, 61%, 56%, and 55% for required temperatures of 40 °C, 50 °C, 60 °C, 70 °C, and 80 °C. As a result, profitability decreases as temperature increases. The useful energy, and therefore the profitability, will decrease if the demand is not distributed throughout the day or focused on the end of the day. The system’s profitability was determined in two cases: considering maximum profitability of the system, assuming 100% utilization of useful energy (scenario 1); assuming a particular demand, considering that on many days all the useful energy the system can supply is not used (scenario 2). The analysis shows that through proper sizing of the system, optimizing the number of solar collectors, the investment in the solar system can be profitable with similar profitability values in the two

  9. Possibilities of heat energy recovery from greywater systems

    Science.gov (United States)

    Niewitecka, Kaja

    2018-02-01

    Waste water contains a large amount of heat energy which is irretrievably lost, so it is worth thinking about the possibilities of its recovery. It is estimated that in a residential building with full sanitary fittings, about 70% of the total tap water supplied is discharged as greywater and could be reused. The subject of the work is the opportunity to reuse waste water as an alternative source of heat for buildings. For this purpose, the design of heat exchangers used in the process of greywater heat recovery in indoor sewage systems, public buildings as well as in industrial plants has been reviewed. The possibility of recovering heat from waste water transported in outdoor sewage systems was also taken into consideration. An exemplary waste water heat recovery system was proposed, and the amount of heat that could be obtained using a greywater heat recovery system in a residential building was presented. The work shows that greywater heat recovery systems allow for significant savings in preheating hot tap water, and the rate of cost reimbursement depends on the purpose of the building and the type of installation. At the same time, the work shows that one should adjust the construction solutions of heat exchangers and indoor installations in buildings to the quality of the medium flowing, which is greywater.

  10. Fuel savings with conventional hot water space heating systems by incorporating a natural gas powered heat pump. Preliminary project: Development of heat pump technology

    Science.gov (United States)

    Vanheyden, L.; Evertz, E.

    1980-12-01

    Compression type air/water heat pumps were developed for domestic heating systems rated at 20 to 150 kW. The heat pump is driven either by a reciprocating piston or rotary piston engine modified to operate on natural gas. Particular features of natural gas engines as prime movers, such as waste heat recovery and variable speed, are stressed. Two systems suitable for heat pump operation were selected from among five different mass produced car engines and were modified to incorporate reciprocating piston compressor pairs. The refrigerants used are R 12 and R 22. Test rig data transferred to field conditions show that the fuel consumption of conventional boilers can be reduced by 50% and more by the installation of engine driven heat pumps. Pilot heat pumps based on a 1,600 cc reciprocating piston engine were built for heating four two-family houses. Pilot pump operation confirms test rig findings. The service life of rotary piston and reciprocating piston engines was investigated. The tests reveal characteristic curves for reciprocating piston engines and include exhaust composition measurements.

  11. Solar air heating system for combined DHW and space heating

    Energy Technology Data Exchange (ETDEWEB)

    Oestergaard Jensen, S.; Bosanac, M.

    2002-12-01

    The project deals with the development and testing of a simple system for utilization of the summer excess heat from small solar air heating systems for preheating of fresh air. The principle of the system is to lead the heated air down around a domestic hot water tank letting the surface of the tank act as heat exchanger between the air and the water. In order to increase the heat transfer, coefficient fins into the air stream were mounted on the tank. A complete system with 3 m{sup 2} solar air collector, ductworks and a 85 litre storage were set up and extensively monitored. The air stream through the system was created by a fan connected directly to one or two PV-panels leading to a solar radiation dependent flow rate without the use of any other control. Based on monitoring results the system was characterized and a TRNSYS model of the system was developed and calibrated/validated. The monitoring and the simulations with the TRNSYS model revealed several interesting things about the system. The monitoring revealed that the system is capable of bringing the temperature of the water in the storage above 60 deg. C at warm days with clear sky conditions. The storage is very stratified, which is beneficial as usable hot water temperatures rather quickly are obtained. The performance was highly dependent on the airflow rate through the system. It can be concluded that the investigated system will have a performance in the order of 500 kWh during the winter, spring and autumn months and around 250 kWh during the four summer months - or in total a yearly performance of 750 kWh/m{sup 2}. A small traditional solar heating system for preheating of domestic hot water would have a higher performance during the four summer months, but no performance during the rest of the year if the system is installed in a summer house, which only is occupied during the summer. The parametric analysis further indicates that it is possible to further optimise the system when the thermal

  12. Solar heating and hot water system installed at Municipal Building complex, Abbeville, South Carolina

    Science.gov (United States)

    1979-01-01

    Information on the solar energy system installed at the new municipal building for the City of Abbeville, SC is presented, including a description of solar energy system and buildings, lessons learned, and recommendations. The solar space heating system is a direct air heating system. The flat roof collector panel was sized to provide 75% of the heating requirement based on an average day in January. The collectors used are job-built with two layers of filon corrugated fiberglass FRP panels cross lapped make up the cover. The storage consists of a pit filled with washed 3/4 in - 1 1/2 in diameter crushed granite stone. The air handler includes the air handling mechanism, motorized dampers, air circulating blower, sensors, control relays and mode control unit. Solar heating of water is provided only those times when the hot air in the collector is exhausted to the outside.

  13. Performance of commercially available solar and heat pump water heaters

    International Nuclear Information System (INIS)

    Lloyd, C.R.; Kerr, A.S.D.

    2008-01-01

    Many countries are using policy incentives to encourage the adoption of energy-efficient hot water heating as a means of reducing greenhouse gas emissions. Such policies rely heavily on assumed performance factors for such systems. In-situ performance data for solar and heat pump hot water systems, however, are not copious in the literature. Otago University has been testing some systems available in New Zealand for a number of years. The results obtained are compared to international studies of in-situ performance of solar hot water systems and heat pump hot water systems, by converting the results from the international studies into a single index suitable for both solar and heat pump systems (COP). Variability in the international data is investigated as well as comparisons to model results. The conclusions suggest that there is not too much difference in performance between solar systems that have a permanently connected electric boost backup and heat pump systems over a wide range of environmental temperatures. The energy payback time was also calculated for electric boost solar flat plate systems as a function of both COP and hot water usage for a given value of embodied energy. The calculations generally bode well for solar systems but ensuring adequate system performance is paramount. In addition, such systems generally favour high usage rates to obtain good energy payback times

  14. Study and Optimization of Design Parameters in Water Loop Heat Pump Systems for Office Buildings in the Iberian Peninsula

    Directory of Open Access Journals (Sweden)

    Francisco Javier Fernández

    2017-11-01

    Full Text Available Water loop heat pump (WLHP air conditioning systems use heat pumps connected to a common water circuit to fulfill the energy demands of different thermal zones in a building. In this study, the energy consumption was analyzed for the air conditioning of an office building in the typical climate of four important cities of the Iberian Peninsula. The energy consumption of one water loop heat pump system was compared with a conventional water system. Two design parameters, the range in the control temperatures and the water loop thermal storage size, were tested. Energy redistribution is an important advantage of the WLHP system, but significant savings came from high efficiency parameters in the heat pumps and minor air flow rates in the cooling tower. The low thermal level in the water loop makes this technology appropriate to combine with renewable sources. Using natural gas as the thermal energy source, a mean decrease in CO2 emissions of 8.1% was reached. Simulations showed that the installation of big thermal storage tanks generated small energy savings. Besides, the total annual consumption in buildings with high internal loads can be reduced by keeping the water loop as cool as possible.

  15. Side-by-Side Testing of Water Heating Systems: Results from the 2013–2014 Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Colon, Carlos [Florida Solar Energy Center, Cocoa, FL (United States). Building America Partnership for Improved Residential Construction (BA-PIRC)

    2017-07-01

    The Florida Solar Energy Center (FSEC) completed a fourth year-long evaluation on residential hot water heating systems in a laboratory environment (east central Florida, hot-humid climate). The evaluation studied the performance of five hot water systems (HWS) plus a reference baseline system for each fuel, (i.e., electric and natural gas). Electric HWS consisted of two residential electric heat pump water heaters (HPWHs, 60 and 80 gallons), a solar thermal system using a polymer absorber (glazed) collector with 80-gallon storage and a duplicate 50-gallon standard electric water heater with added cap and wrap insulation. Baseline performance data were collected from a standard 50-gallon electric water heater of minimum code efficiency to compare energy savings. Similarly, a standard 40-gallon upright vented natural gas water heater served as baseline for the natural gas fuel category. The latter, having a larger jacket diameter [18 in., with an energy factor (EF) of 0.62] with increased insulation, replaced a former baseline (17 in. diameter, EF = 0.59) that served during three previous testing rotations (2009–2013). A high-efficiency, condensing natural gas hybrid water heater with 27-gallon buffered tank was also tested and compared against the gas baseline. All systems underwent testing simultaneously side-by-side under the criteria specified elsewhere in this report.

  16. Fuzzy comprehensive evaluation of district heating systems

    International Nuclear Information System (INIS)

    Wei Bing; Wang Songling; Li Li

    2010-01-01

    Selecting the optimal type of district heating (DH) system is of great importance because different heating systems have different levels of efficiency, which will impact the system economics, environment and energy use. In this study, seven DH systems were analysed and evaluated by the fuzzy comprehensive evaluation method. The dimensionless number-goodness was introduced into the calculation, the economics, environment and energy technology factors were considered synthetically, and the final goodness values were obtained. The results show that if only one of the economics, environment or energy technology factors are considered, different heating systems have different goodness values. When all three factors were taken into account, the final ranking of goodness values was: combined heating and power>gas-fired boiler>water-source heat pump>coal-fired boiler>ground-source heat pump>solar-energy heat pump>oil-fired boiler. The combined heating and power system is the best choice from all seven systems; the gas-fired boiler system is the best of the three boiler systems for heating purpose; and the water-source heat pump is the best of the three heat pump systems for heating and cooling.

  17. Reduction of carbon dioxide emissions by solar water heating systems and passive technologies in social housing

    International Nuclear Information System (INIS)

    Bessa, Vanessa M.T.; Prado, Racine T.A.

    2015-01-01

    Growing global concern regarding climate change motivates technological studies to minimize environmental impacts. In this context, solar water heating (SWH) systems are notably prominent in Brazil, primarily because of the abundance of solar energy in the country. However, SWH designs have not always been perfectly developed. In most projects, the installation option of the solar system only considers the electric power economy aspects and not the particular characteristics of each climatic zone. Thus, the primary objective of this paper is to assess the potential of carbon dioxide reduction with the use of SWH in comparison with electric showers in social housing in several Brazilian climatic zones. The Brazilian government authorities have created public policies to encourage the use of these technologies primarily among the low-income population. The results of this paper indicate that hot climactic regions demonstrate a low reduction of CO 2 emissions with SWH installations. Thus, solar radiation is not useful for water heating in those regions, but it does lead to a large fraction of household cooling loads, implying a demand for electrical energy for air conditioning or requiring the adoption of passive techniques to maintain indoor temperatures below threshold values. -- Graphical abstract: Display Omitted -- Highlights: •Brazil has created public policies to increase the use of solar water heating in social housing. •We have evaluated the potential for reduction of CO 2 emissions installing solar water heating. •We have found that the coldest regions have the greatest potential for reducing emissions. •Passive technologies for thermal comfort in hot climate households are more useful than solar water heating systems

  18. Solar heating and domestic hot water system installed at North Dallas High School

    Science.gov (United States)

    1980-01-01

    The solar energy system located at the North Dallas High School, Dallas, Texas is discussed. The system is designed as a retrofit in a three story with basement, concrete frame high school building. Extracts from the site files, specification references for solar modification to existing building heating and domestic hot water systems, drawings, installation, operation and maintenance instructions are included.

  19. Development of a thermal storage system based on the heat of adsorption of water in hygroscopic materials

    NARCIS (Netherlands)

    Wijsman, A.J.T.M.; Oosterhaven, R.; Ouden, C. den

    1979-01-01

    A thermal storage system based on the heat of adsorption of water in hygroscopic materials has been studied as a component of a solar space heating system. The aim of this project is to decrease the storage volume in comparison with a rock-bed storage system by increasing the stored energy density.

  20. 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.

  1. Three-objective optimization of a novel triple-effect absorption heat transformer combined with a water desalination system

    International Nuclear Information System (INIS)

    Mahmoudi, S.M.S.; Salehi, S.; Yari, M.

    2017-01-01

    Highlights: • A new type of triple-effect absorption heat transformers is proposed. • A temperature lift of 180 °C is obtained by the proposed system. • The proposed system is observed to be the most effective. • The highest distilled water mass flow rate is obtained by the proposed system. - Abstract: A novel triple-effect absorption heat transformer is proposed and compared with a most studied configuration of triple-effect absorption heat transformer and a modified form of it from the viewpoint of exergoeconomics. All systems are integrated with water desalination system to produced distilled water. Sensitivity analyses are performed to identify the influence on the systems’ performance of such decision parameters as the temperatures of evaporator, condenser, absorber and absorbing evaporators for all the configurations. Then a three-objective optimization is accomplished to specify the optimal design points for the purpose of minimizing the product unit cost and maximizing the exergy coefficient of performance as well as the distilled water mass flow rate. In this regard, the Pareto frontiers are plotted for all the systems. The results show that, under the optimized conditions, the exergy coefficient of performance and distilled water mass flow rate for the proposed configuration can be higher by 16% and 38% with respect to the corresponding values in the other two systems. In addition, it is observed that the maximum gross temperature lift in the proposed system is about 20–40% higher than those in the other systems.

  2. The dry heat exchanger calorimeter system

    International Nuclear Information System (INIS)

    Renz, D.P.; Wetzel, J.R.; James, S.J.; Kasperski, P.W.; Duff, M.F.

    1991-01-01

    A radiometric isothermal heat flow calorimeter and preconditioner system that uses air instead of water as the heat exchange medium has been developed at Mound. The dry heat exchanger calorimeter is 42 inches high by 18 inches in diameter and the preconditioner is a 22 inch cube, making it extremely compact compared to existing units. The new system is ideally suited for transportable, stand-alone, or glovebox applications. Preliminary tests of the system have produced sample measurements with standard deviations less than 0.25% and sample errors less than 0.50%. These tests have shown that the dry heat exchanger system will yield acceptance data with an accuracy comparable to those of Mound water bath systems now in use. 4 figs., 1 tab

  3. Solar heating and hot water system installed at Alderson Broaddus College, Philippi, West Virginia

    Science.gov (United States)

    1981-01-01

    Data needed necessary to evaluate the design and operation of a solar energy heating and hot water system installed in a commercial application are presented. The information includes system descriptions, acceptance test data, schematics, as built drawing, problems encountered, all solutions and photographs of the system at various stages of completion.

  4. An innovative pool with a passive heat removal system

    International Nuclear Information System (INIS)

    Vitale Di Maio, Damiano; Naviglio, Antonio; Giannetti, Fabio; Manni, Fabio

    2012-01-01

    Heat removal systems are of primary importance in several industrial processes. As heat sink, a water pool or atmospheric air may be selected. The first solution takes advantage of high heat transfer coefficient with water but it requires active systems to maintain a constant water level; the second solution takes benefit from the unlimited heat removal capacity by air, but it requires a larger heat exchanger to compensate the lower heat transfer coefficient. In NPPs (nuclear power plants) during a nuclear reactor shutdown, as well as in some chemical plants to control runaway reactions, it is possible to use an innovative heat sink that joins the advantages of the two previous solutions. This solution is based on a special heat exchanger submerged in a water pool designed so that when heat removal is requested, active systems are not required to maintain the water level; due to the special design, when the pool is empty, atmospheric air becomes the only heat sink. The special heat exchanger design allows to have a heat exchanger without being oversized and to have a system able to operate for unlimited period without external interventions. This innovative system provides an economic advantage as well as enhanced safety features.

  5. Heat losses through pipe connections in hot water stores

    DEFF Research Database (Denmark)

    Andersen, Elsa; Fan, Jianhua; Furbo, Simon

    2007-01-01

    The heat loss from pipe connections at the top of hot water storage tanks with and without a heat trap is investigated theoretically and compared to similar experimental investigations. Computational Fluid Dynamics (CFD) is used for the theoretical analysis. The investigations show that the heat...... loss from an ideally insulated pipe connected to the top of a hot water tank is mainly due to a natural convection flow in the pipe, that the heat loss coefficient of pipes connected to the top of a hot water tank is high, and that a heat trap can reduce the heat loss coefficient significantly. Further......, calculations show that the yearly thermal performance of solar domestic hot water systems is strongly reduced if the hot water tank has a thermal bridge located at the top of the tank....

  6. Regional analysis of residential water heating options: energy use and economics

    Energy Technology Data Exchange (ETDEWEB)

    O' Neal, D.; Carney, J.; Hirst, E.

    1978-10-01

    This report evaluates the energy and direct economic effects of introducing improved electric-water-heating systems to the residential market. These systems are: electric heat pumps offered in 1981, solar systems offered in 1977, and solar systems offered in 1977 with a Federal tax credit in effect from 1977 through 1984. The ORNL residential energy model is used to calculate energy savings by type of fuel for each system in each of the ten Federal regions and for the nation as a whole for each year between 1977 and 2000. Changes in annual fuel bills and capital costs for water heaters are also computed at the same level of detail. Model results suggest that heat-pump water heaters are likely to offer much larger energy and economic benefits than will solar systems, even with tax credits. This is because heat pumps provide about the same savings in electricity for water heating (about half) at a much lower capital cost ($700 to $2000) than do solar systems. However, these results are based on highly uncertain estimates of future performance and cost characteristics for both heat pump and solar systems. The cumulative national energy saving by the year 2000 due to commercialization of heat-pump water heaters in 1981 is estimated to be 1.5 QBtu. Solar-energy benefits are about half this much without tax credits and two-thirds as much with tax credits. The net economic benefit to households of heat-pump water heaters (present worth of fuel bill reductions less the present worth of extra costs for more-efficient systems) is estimated to be $640 million. Again, the solar benefits are much less.

  7. Development of In-Service Inspection system for heat transfer tubes in the primary pressurized water cooler in the HTTR

    Energy Technology Data Exchange (ETDEWEB)

    Shinozaki, Masayuki; Furusawa, Takayuki [Japan Atomic Energy Research Inst., Oarai, Ibaraki (Japan). Oarai Research Establishment; Wada, Shigeyuki

    1999-08-01

    The ISI (In-Service Inspection) system has been developed so as to maintain the structural integrity of heat transfer tubes in the primary pressurized water cooler in the HTTR (High Temperature Engineering Test Reactor). This system consists of eddy current probes, ultra-sonic probes, insertion and extraction units, positioning unit and so on. Verification and performance tests of the developed ISI system were carried out using mock-up heat transfer tubes in the primary pressurized water cooler. The constitution of the system, R and D results of the inspection probes, and verification and performance test results of the ISI system for heat transfer tubes are described in this paper. (author)

  8. Avoidance of damage in hot water heating systems. Part 2. Corrosion and water, a status report; Vermeidung von Schaeden in Warmwasserheizungen. Teil 2. Korrosion und Heizungswasser - eine Standortbestimmung

    Energy Technology Data Exchange (ETDEWEB)

    Lapp, H.; Hannemann, M. [Deutsche Erfinderverband fuer Muenchen und Oberbayern (Germany); Deutsche Gewerbeverband fuer Markt Schwaben und die Region (Germany)

    2003-02-01

    Water is used in nearly every heating system, so it is important to know about the characteristics of this important heat carrier, its interactions with heating system materials, and other aspects. The contribution presents the main characteristics of common waters, their effects on heating systems, and common water treatement methods. [German] Praktisch in jeder Heizung wird Wasser als Waermetraeger verwendet. Aus diesem Grunde ist es in jedem Fall ratsam, die Eigenschaften dieses speziellen Waermetraegers, seine Wechselwirkungen mit den Heizungswerkstoffen und andere Besonderheiten zu kennen. In dem folgenden Artikel werden die wichtigsten Eigenschaften gebraeuchlicher Waesser und deren Auswirkungen auf die Heizungsanlagen dargelegt sowie die wichtigsten Behandlungsverfahren vorgestellt. (orig.)

  9. Economic feasibility of solar water and space heating.

    Science.gov (United States)

    Bezdek, R H; Hirshberg, A S; Babcock, W H

    1979-03-23

    The economic feasibility in 1977 and 1978 of solar water and combined water and space heating is analyzed for single-family detached residences and multi-family apartment buildings in four representative U.S. cities: Boston, Massachusetts; Washington, D.C.; Grand Junction, Colorado; and Los Angeles, California. Three economic decision criteria are utilized: payback period, years to recovery of down payment, and years to net positive cash flow. The cost competitiveness of the solar systems compared to heating systems based on electricity, fuel oil, and natural gas is then discussed for each city, and the impact of the federal tax credit for solar energy systems is assessed. It is found that even without federal incentives some solar water and space heating systems are competitive. Enactment of the solar tax credit, however, greatly enhances their competitiveness. The implications of these findings for government tax and energy pricing policies are discussed.

  10. Heat-pump-centered integrated community energy systems: system development summary

    Energy Technology Data Exchange (ETDEWEB)

    Calm, J.M.

    1980-02-01

    An introduction to district heating systems employing heat pumps to enable use of low-temperature energy sources is presented. These systems operate as thermal utilities to provide space heating and may also supply space cooling, service-water heating, and other thermal services. Otherwise-wasted heat from industrial and commercial processes, natural sources including solar and geothermal heat, and heat stored on an annual cycle from summer cooling may be effectively utilized by the systems described. These sources are abundant, and their use would conserve scarce resources and reduce adverse environmental impacts. More than one-quarter of the energy consumed in the United States is used to heat and cool buildings and to heat service water. Natural gas and oil provide approximately 83% of this energy. The systems described show potential to reduce net energy consumption for these services by 20 to 50% and to allow fuel substitution with less-scarce resources not practical in smaller, individual-building systems. Seven studies performed for the system development phase of the Department of Energy's Heat-Pump-Centered Integrated Community Energy Systems Project and to related studies are summarized. A concluding chapter tabulates data from these separately published studies.

  11. Multifamily Heat Pump Water Heater Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Hoeschele, M. [Alliance for Residential Building Innovation (ARBI), Davis, CA (United States); Weitzel, E. [Alliance for Residential Building Innovation (ARBI), Davis, CA (United States)

    2013-11-22

    Although heat pump water heaters (HPWHs) have gained significant attention in recent years as a high efficiency electric water heating solution for single family homes, central HPWHs for commercial or multi-family applications are not as well documented in terms of measured performance and cost effectiveness. To evaluate this technology, the Alliance for Residential Building Innovation team monitored the performance of a 10.5 ton central HPWH installed on a student apartment building at the West Village Zero Net Energy Community in Davis, California. Monitoring data collected over a 16 month period were then used to validate a TRNSYS simulation model. The TRNSYS model was then used to project performance in different climates using local electric rates. Results of the study indicate that after some initial commissioning issues, the HPWH operated reliably with an annual average efficiency of 2.12 (Coefficient of Performance). The observed efficiency was lower than the unit's rated efficiency, primarily due to the fact that the system rarely operated under steady-state conditions. Changes in the system configuration, storage tank sizing, and control settings would likely improve the observed field efficiency. Modeling results suggest significant energy savings relative to electric storage water heating systems (typical annual efficiencies around 0.90) providing for typical simple paybacks of six to ten years without any incentives. The economics versus gas water heating are currently much more challenging given the current low natural gas prices in much of the country. Increased market size for this technology would benefit cost effectiveness and spur greater technology innovation.

  12. Multifamily Heat Pump Water Heater Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Hoeschele, M. [Davis Energy Group, Davis, CA (United States). Alliance for Residential Building Innovation; Weitzel, E. [Davis Energy Group, Davis, CA (United States). Alliance for Residential Building Innovation

    2017-03-03

    Although heat pump water heaters (HPWHs) have gained significant attention in recent years as a high efficiency electric water heating solution for single family homes, central HPWHs for commercial or multi-family applications are not as well documented in terms of measured performance and cost effectiveness. To evaluate this technology, the Alliance for Residential Building Innovation team monitored the performance of a 10.5 ton central HPWH installed on a student apartment building at the West Village Zero Net Energy Community in Davis, California. Monitoring data collected over a 16 month period were then used to validate a TRNSYS simulation model. The TRNSYS model was then used to project performance in different climates using local electric rates. Results of the study indicate that after some initial commissioning issues, the HPWH operated reliably with an annual average efficiency of 2.12 (Coefficient of Performance). The observed efficiency was lower than the unit's rated efficiency, primarily due to the fact that the system rarely operated under steady-state conditions. Changes in the system configuration, storage tank sizing, and control settings would likely improve the observed field efficiency. Modeling results suggest significant energy savings relative to electric storage water heating systems (typical annual efficiencies around 0.90) providing for typical simple paybacks of six to ten years without any incentives. The economics versus gas water heating are currently much more challenging given the current low natural gas prices in much of the country. Increased market size for this technology would benefit cost effectiveness and spur greater technology innovation.

  13. Multifamily Heat Pump Water Heater Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Hoeschele, M. [Alliance for Residential Building Innovation (ARBI), Davis, CA (United States); Weitzel, E. [Alliance for Residential Building Innovation (ARBI), Davis, CA (United States)

    2017-03-01

    Although heat pump water heaters (HPWHs) have gained significant attention in recent years as a high efficiency electric water heating solution for single family homes, central HPWHs for commercial or multi-family applications are not as well documented in terms of measured performance and cost effectiveness. To evaluate this technology, the Alliance for Residential Building Innovation team monitored the performance of a 10.5 ton central HPWH installed on a student apartment building at the West Village Zero Net Energy Community in Davis, California. Monitoring data collected over a 16 month period were then used to validate a TRNSYS simulation model. The TRNSYS model was then used to project performance in different climates using local electric rates. Results of the study indicate that after some initial commissioning issues, the HPWH operated reliably with an annual average efficiency of 2.12 (Coefficient of Performance). The observed efficiency was lower than the unit's rated efficiency, primarily due to the fact that the system rarely operated under steady-state conditions. Changes in the system configuration, storage tank sizing, and control settings would likely improve the observed field efficiency. Modeling results suggest significant energy savings relative to electric storage water heating systems (typical annual efficiencies around 0.90) providing for typical simple paybacks of six to ten years without any incentives. The economics versus gas water heating are currently much more challenging given the current low natural gas prices in much of the country. Increased market size for this technology would benefit cost effectiveness and spur greater technology innovation.

  14. Evaluation of trigeneration system using microturbine, ammonia-water absorption chiller, and a heat recovery boiler

    Energy Technology Data Exchange (ETDEWEB)

    Preter, Felipe C.; Rocha, Marcelo S.; Simoes-Moreira, Jose Roberto [SISEA - Alternative Energy Systems Lab. Dept. of Mechanical Engineering. University of Sao Paulo (EP/USP), SP (Brazil)], e-mails: felipe.preter@poli.usp.br, msrocha@poli.usp.br, jrsimoes@usp.br; Andreos, Ronaldo [COMGAS - Companhia de Gas de Sao Paulo, SP (Brazil)], e-mail: randreos@comgas.com.br

    2010-07-01

    In this work, a CCHP or tri generation system has been projected, mounted, and tested in laboratory, combining a microturbine for power generation, a heat recovery boiler for hot water production, and an ammonia water absorption chiller for chilled water production. The project was motivated by the large practical applications of this kind of energy recovery system in commerce, and industry, and, in general, more than 85% of the energy source is used as power, hot water, and cold water. In the first part, the trigeneration system theoretical model is detailed, and in the second part, experimental results are presented for different operation conditions. (author)

  15. Study on the simulation of heat pump heating and cooling systems to hospital building

    International Nuclear Information System (INIS)

    Choi, Young Don; Han, Seong Ho; Cho, Sung Hwan; Kim, Du Sung; Um, Chul Jun

    2008-01-01

    In Korea, air source heat pump system is less efficient than conventional heat source facilities, because the air temperature in winter season is so low that COP of air source heat pump system drops below 3.0. Therefore, the study on the application of heat pump heating and cooling systems is crucial for the efficient popularization of heat pump. In this work, we present the dynamic analysis of energy consumption for the large hospital building by heat resistance-capacitance method. The system simulation of water storage air source heat pump is additionally performed by changing sizes and locations of the hospital building. The computed results show that energy cost of water storage air source heat pump is low, so it is more economical than absorption chiller and heater

  16. Energy saving type area hot water supply system using heat of hot waste water from the sludge center as hot source for hot water; New energy rokko airando CITY. Surajjisenta karano onhaisuinetsu wo kyuyuyo netsugen ni riyosuru sho energy gata chiiki onsui kyokyu system

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-01-01

    Heat source of area hot water supply system in Rokko island City (man-made island) is heat of combustion at the sludge center (sludge incineration plant) in this island. Dehydrated sludge cakes (230ton/day) brought from seven sewage disposal plants in Kobe City is combusted (850degC) in the fluid bed hearth. Combustion gas washed in the scrubber, hot waste water after the washing give heat into heat transfer water in the first heat exchanger. Temperature being 64degC in summer and about 50degC in winter, this heat transfer water is sent into the second heat exchanger at every condominium building throughout the pipe line system circulating in the area. At each home, gas heater and hot water supply devices fitted, additional combustion is not necessary in summer but is used according to demand in other seasons. This hot water supply service has been carried out since 1988 and at present has been used by 3600 homes. Amount of supplying hot water being about 3000cu.m/day, saving is calculated roughly as 60% of gas for hot water supply. Fee for this system is 1500/yen/month uniformly for each home. 14 figs.

  17. Validation of a simulation method for forced circulation type of solar domestic hot water heating systems; Kyosei junkangata taiyonetsu kyuto system simulation hoho no kensho

    Energy Technology Data Exchange (ETDEWEB)

    Sato, M; Udagawa, M [Kogakuin University, Tokyo (Japan); Matsumoto, T [Yazaki Corp., Tokyo (Japan)

    1996-10-27

    Simulation of solar hot water systems using element model was conducted, in which computation of the convergence of apparatus characteristic values was performed every hour. For each apparatus, the outlet temperature was made a function of the inlet temperature on the basis of the heat balance, from which a simultaneous equation was derived and then solved for the determination of the outlet temperature for the computation of the quantity of heat collected by each apparatus. The actually measured system comprises a planar solar collector, heat storage tank, and heat collector piping. The measurement involved a direct heat collecting system with the medium running from the heat storage tank bottom layer, through the solar collector, and then back to the heat storage tank third layer, and an indirect heat collector system with a heat exchanger provided at the heat storage tank bottom layer. There was no substantial difference between the direct type and the indirect type with respect to the solar collector inlet and outlet temperatures, quantity of heat collected, and the fluctuation in heat storage tank inside temperature distribution relative to time. Difference occurred between the two in tank water temperature distribution, however, when water was extracted in great volume at a time. The quantity of the heat collected by each of the two and the daily integration of the same differed but a little from computed values. 4 refs., 6 figs., 4 tabs.

  18. Exergy analysis of a system using a chemical heat pump to link a supercritical water-cooled nuclear reactor and a thermochemical water splitting cycle

    International Nuclear Information System (INIS)

    Granovskii, M.; Dincer, I.; Rosen, M. A.; Pioro, I

    2007-01-01

    the heat transfer to the water splitting cycle. A preliminary exergy analysis of the proposed heat pump is conducted and a coefficient of performance (COP), taking into account a decrease in electricity generation in the nuclear power generation cycle, is evaluated. The calculated per unit mass flow heat supply rate to the thermochemical cycle increases by a factor of 3 to 5 depending on the steam temperature. A combined system comprising a SCW nuclear plant, a chemical heat pump and a lower temperature UT-3 thermochemical water splitting cycle is presented. Despite a decrease in electricity generation, the calculated exergy efficiency of hydrogen production in the considered system appears to be competitive with that for low temperature water electrolysis

  19. Development of a nonazeotropic heat pump for crew hygiene water heating

    Science.gov (United States)

    Walker, David H.; Deming, Glenn I.

    1991-01-01

    A heat pump system is currently under development to produce hot water for crew hygiene on future manned space missions. The heat pump uses waste heat sources and a nonazeotropic working fluid in a highly efficient cycle. The potential benefits include a reduction in peak power draw from 2 to 5 kW for electric cartridge heaters to just more than 100 W for the heat pump. As part of the heat pump development project, a unique high efficiency compressor was developed to maintain lubrication in a zero-gravity environment.

  20. DBP formation in hot and cold water across a simulated distribution system: effect of incubation time, heating time, pH, chlorine dose, and incubation temperature.

    Science.gov (United States)

    Liu, Boning; Reckhow, David A

    2013-10-15

    This paper demonstrates that disinfection byproducts (DBP) concentration profiles in heated water were quite different from the DBP concentrations in the cold tap water. Chloroform concentrations in the heated water remained constant or even decreased slightly with increasing distribution system water age. The amount of dichloroacetic acid (DCAA) was much higher in the heated water than in the cold water; however, the maximum levels in heated water with different distribution system water ages did not differ substantially. The levels of trichloroacetic acid (TCAA) in the heated water were similar to the TCAA levels in the tap water, and a slight reduction was observed after the tap water was heated for 24 h. Regardless of water age, significant reductions of nonregulated DBPs were observed after the tap water was heated for 24 h. For tap water with lower water ages, there were significant increases in dichloroacetonitrile (DCAN), chloropicrin (CP), and 1,1-dichloropropane (1,1-DCP) after a short period of heating. Heating of the tap water with low pH led to a more significant increase of chloroform and a more significant short-term increase of DCAN. High pH accelerated the loss of the nonregulated DBPs in the heated water. The results indicated that as the chlorine doses increased, levels of chloroform and DCAA in the heated water increased significantly. However, for TCAA, the thermally induced increase in concentration was only notable for the chlorinated water with very high chlorine dose. Finally, heating may lead to higher DBP concentrations in chlorinated water with lower distribution system temperatures.

  1. Laboratory Evaluation of Gas-Fired Tankless and Storage Water Heater Approaches to Combination Water and Space Heating

    Energy Technology Data Exchange (ETDEWEB)

    Kingston, T.; Scott, S.

    2013-03-01

    Homebuilders are exploring more cost effective combined space and water heating systems (combo systems) with major water heater manufacturers that are offering pre-engineered forced air space heating combo systems. In this project, unlike standardized tests, laboratory tests were conducted that subjected condensing tankless and storage water heater based combo systems to realistic, coincidental space and domestic hot water loads with the following key findings: 1) The tankless combo system maintained more stable DHW and space heating temperatures than the storage combo system. 2) The tankless combo system consistently achieved better daily efficiencies (i.e. 84%-93%) than the storage combo system (i.e. 81%- 91%) when the air handler was sized adequately and adjusted properly to achieve significant condensing operation. When condensing operation was not achieved, both systems performed with lower (i.e. 75%-88%), but similar efficiencies. 3) Air handlers currently packaged with combo systems are not designed to optimize condensing operation. More research is needed to develop air handlers specifically designed for condensing water heaters. 4) System efficiencies greater than 90% were achieved only on days where continual and steady space heating loads were required with significant condensing operation. For days where heating was more intermittent, the system efficiencies fell below 90%.

  2. Retrofitting Conventional Electric Domestic Hot Water Heaters to Solar Water Heating Systems in Single-Family Houses—Model Validation and Optimization

    Directory of Open Access Journals (Sweden)

    Luis R. Bernardo

    2013-02-01

    Full Text Available System cost reductions and development of standardised plug-and-function systems are some of the most important goals for solar heating technology development. Retrofitting hot water boilers in single-family houses when installing solar collectors has the potential to significantly reduce both material and installation costs. In this study, the TRNSYS simulation models of the retrofitting solar thermal system were validated against measurements. Results show that the validated models are in good agreement with measurements. On an annual basis a deviation of 2.5% out of 1099 kWh was obtained between the auxiliary energy from results and from the simulation model for a complete system. Using the validated model a system optimization was carried out with respect to control strategies for auxiliary heating, heat losses and volume of auxiliary storage. A sensitivity analysis was carried out regarding different volumes of retrofitted hot water boiler, DHW profiles and climates. It was estimated that, with adequate improvements, extended annual solar fractions of 60%, 78% and 81% can be achieved for Lund (Sweden, Lisbon (Portugal and Lusaka (Zambia, respectively. The correspondent collector area was 6, 4 and 3 m2, respectively. The studied retrofitted system achieves a comparable performance with conventional solar thermal systems with the potential to reduce the investment cost.

  3. Performance Analysis and Application of Three Different Computational Methods for Solar Heating System with Seasonal Water Tank Heat Storage

    Directory of Open Access Journals (Sweden)

    Dongliang Sun

    2013-01-01

    Full Text Available We analyze and compare three different computational methods for a solar heating system with seasonal water tank heat storage (SHS-SWTHS. These methods are accurate numerical method, temperature stratification method, and uniform temperature method. The accurate numerical method can accurately predict the performance of the system, but it takes about 4 to 5 weeks, which is too long and hard for the performance analysis of this system. The temperature stratification method obtains relatively accurate computation results and takes a relatively short computation time, which is about 2 to 3 hours. Therefore, this method is most suitable for the performance analysis of this system. The deviation of the computational results of the uniform temperature method is great, and the time consumed is similar to that of the temperature stratification method. Therefore, this method is not recommended herein. Based on the above analyses, the temperature stratification method is applied to analyze the influence of the embedded depth of water tank, the thickness of thermal insulation material, and the collection area on the performance of this system. The results will provide a design basis for the related demonstration projects.

  4. Match properties of heat transfer and coupled heat and mass transfer processes in air-conditioning system

    International Nuclear Information System (INIS)

    Zhang Tao; Liu Xiaohua; Zhang Lun; Jiang Yi

    2012-01-01

    Highlights: ► Investigates match properties of heat or mass transfer processes in HVAC system. ► Losses are caused by limited transfer ability, flow and parameter mismatching. ► Condition of flow matching is the same heat capacity of the fluids. ► Parameter matching is only reached along the saturation line in air–water system. ► Analytical solutions of heat and mass transfer resistance are derived. - Abstract: Sensible heat exchangers and coupled heat and mass transfer devices between humid air and water/desiccant are commonly used devices in air-conditioning systems. This paper focuses on the match properties of sensible heat transfer processes and coupled heat and mass transfer processes in an effort to understand the reasons for performance limitations in order to optimize system performance. Limited heat transfer capability and flow mismatching resulted in heat resistance of the sensible heat transfer process. Losses occurred during the heat and mass transfer processes due to limited transfer capability, flow mismatching, and parameter mismatching. Flow matching was achieved when the heat capacities of the fluids were identical, and parameter matching could only be reached along the saturation line in air–water systems or the iso-concentration line in air–desiccant systems. Analytical solutions of heat transfer resistance and mass transfer resistance were then derived. The heat and mass transfer process close to the saturation line is recommended, and heating sprayed water resulted in better humidification performance than heating inlet air in the air humidifier.

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

    Science.gov (United States)

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

    2017-01-12

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

  6. Solar heating and hot water system installed at Charlotte Memorial Hospital, Charlotte, North Carolina

    Science.gov (United States)

    1981-01-01

    Detailed information regarding the design and installation of a heating and hot water system in a commercial application is given. This information includes descriptions of system and building, design philosophy, control logic operation modes, design and installation drawing and a brief description of problems encountered and their solutions.

  7. 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.

  8. Heats of immersion in the thorium oxide-water system at elevated temperatures

    International Nuclear Information System (INIS)

    Holmes, H.F.

    1976-01-01

    The surface properties of ThO 2 were studied by heat of immersion calorimetry at 25 to 200 0 C. Results show that the integral heat of immersion of thorium oxide contains contributions which reflect considerable interaction with several layers of water adjacent to the oxide surface. It would be desirable to know the heat capacity changes which occur in the multilayer adsorption of water on an oxide surface. However, such data are not available and their acquisition would be an extremely difficult task. Structuring (a negative ΔCp) of several layers of water (by increased hydrogen bonding) adjacent to an oxide surface could explain an increase in the heat of immersion as the immersion temperature is increased. The more energetic, heterogeneous, high-surface-area samples are expected to induce more order in the adjacent water layers than the less energetic samples. This interpretation is similar to that offered for the temperature dependence of the heat of solution of the alkali halides

  9. Investigation of characteristics of passive heat removal system based on the assembled heat transfer tube

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Xiang Cheng; Yan, Changqi; Meng, Zhao Ming; Chen, Kailun; Song, Shao Chuang; Yang, Zong Hao; Yu, Jie [Fundamental Science on Nuclear Safety and Simulation Technology Laboratory, Harbin Engineering University, Harbin (China)

    2016-12-15

    To get an insight into the operating characteristics of the passive residual heat removal system of molten salt reactors, a two-phase natural circulation test facility was constructed. The system consists of a boiling loop absorbing the heat from the drain tank, a condensing loop consuming the heat, and a steam drum. A steady-state experiment was carried out, in which the thimble temperature ranged from 450 .deg. C to 700 .deg. C and the system pressure was controlled at levels below 150 kPa. When reaching a steady state, the system was operated under saturated conditions. Some important parameters, including heat power, system resistance, and water level in the steam drum and water tank were investigated. The experimental results showed that the natural circulation system is feasible in removing the decay heat, even though some fluctuations may occur in the operation. The uneven temperature distribution in the water tank may be inevitable because convection occurs on the outside of the condensing tube besides boiling with decreasing the decay power. The instabilities in the natural circulation loop are sensitive to heat flux and system resistance rather than the water level in the steam drum and water tank. RELAP5 code shows reasonable results compared with experimental data.

  10. Investigation of Characteristics of Passive Heat Removal System Based on the Assembled Heat Transfer Tube

    Directory of Open Access Journals (Sweden)

    Xiangcheng Wu

    2016-12-01

    Full Text Available To get an insight into the operating characteristics of the passive residual heat removal system of molten salt reactors, a two-phase natural circulation test facility was constructed. The system consists of a boiling loop absorbing the heat from the drain tank, a condensing loop consuming the heat, and a steam drum. A steady-state experiment was carried out, in which the thimble temperature ranged from 450°C to 700°C and the system pressure was controlled at levels below 150 kPa. When reaching a steady state, the system was operated under saturated conditions. Some important parameters, including heat power, system resistance, and water level in the steam drum and water tank were investigated. The experimental results showed that the natural circulation system is feasible in removing the decay heat, even though some fluctuations may occur in the operation. The uneven temperature distribution in the water tank may be inevitable because convection occurs on the outside of the condensing tube besides boiling with decreasing the decay power. The instabilities in the natural circulation loop are sensitive to heat flux and system resistance rather than the water level in the steam drum and water tank. RELAP5 code shows reasonable results compared with experimental data.

  11. Evaluation of heat exchange performance for the auxiliary component cooling water system cooling tower in HTTR

    International Nuclear Information System (INIS)

    Tochio, Daisuke; Kameyama, Yasuhiko; Shimizu, Atsushi; Inoi, Hiroyuki; Yamazaki, Kazunori; Shimizu, Yasunori; Aragaki, Etsushi; Ota, Yukimaru; Fujimoto, Nozomu

    2006-09-01

    The auxiliary component cooling water system (ACCWS) is one of the cooling system in High Temperature Engineering Test Reactor (HTTR). The ACCWS has main two features, many facilities cooling, and heat sink of the vessel cooling system which is one of the engineering safety features. Therefore, the ACCWS is required to satisfy the design criteria of heat removal performance. In this report, heat exchange performance data of the rise-to-power-up test and the in-service operation for the ACCWS cooling tower was evaluated. Moreover, the evaluated values were compared with the design values, and it is confirmed that ACCWS cooling tower has the required heat exchange performance in the design. (author)

  12. Performance study of heat-pipe solar photovoltaic/thermal heat pump system

    International Nuclear Information System (INIS)

    Chen, Hongbing; Zhang, Lei; Jie, Pengfei; Xiong, Yaxuan; Xu, Peng; Zhai, Huixing

    2017-01-01

    Highlights: • The testing device of HPS PV/T heat pump system was established by a finished product of PV panel. • A detailed mathematical model of heat pump was established to investigate the performance of each component. • The dynamic and static method was combined to solve the mathematical model of HPS PV/T heat pump system. • The HPS PV/T heat pump system was optimized by the mathematical model. • The influence of six factors on the performance of HPS PV/T heat pump system was analyzed. - Abstract: A heat-pipe solar (HPS) photovoltaic/thermal (PV/T) heat pump system, combining HPS PV/T collector with heat pump, is proposed in this paper. The HPS PV/T collector integrates heat pipes with PV panel, which can simultaneously generate electricity and thermal energy. The extracted heat from HPS PV/T collector can be used by heat pump, and then the photoelectric conversion efficiency is substantially improved because of the low temperature of PV cells. A mathematical model of the system is established in this paper. The model consists of a dynamic distributed parameter model of the HPS PV/T collection system and a quasi-steady state distributed parameter model of the heat pump. The mathematical model is validated by testing data, and the dynamic performance of the HPS PV/T heat pump system is discussed based on the validated model. Using the mathematical model, a reasonable accuracy in predicting the system’s dynamic performance with a relative error within ±15.0% can be obtained. The capacity of heat pump and the number of HPS collectors are optimized to improve the system performance based on the mathematical model. Six working modes are proposed and discussed to investigate the effect of solar radiation, ambient temperature, supply water temperature in condenser, PV packing factor, heat pipe pitch and PV backboard absorptivity on system performance by the validated model. It is found that the increase of solar radiation, ambient temperature and PV

  13. TPX heating and cooling system

    International Nuclear Information System (INIS)

    Kungl, D.J.; Knutson, D.S.; Costello, J.; Stoenescu, S.; Yemin, L.

    1995-01-01

    TPX, while having primarily super-conducting coils that do not require water cooling, still has very significant water cooling requirements for the plasma heating systems, vacuum vessel, plasma facing components, diagnostics, and ancillary equipment. This is accentuated by the 1000-second pulse requirement. Two major design changes, which have significantly affected the TPX Heating and Cooling System, have been made since the conceptual design review in March of 1993. This paper will discuss these changes and review the current status of the conceptual design. The first change involves replacing the vacuum vessel neutron shielding configuration of lead/glass composite tile by a much simpler and more reliable borated water shield. The second change reduces the operating temperature of the vacuum vessel from 150 C to ≥50 C. With this temperature reduction, all in-vessel components and the vessel will be supplied by coolant at a common ≥50 C inlet temperature. In all, six different heating and cooling supply requirements (temperature, pressure, water quality) for the various TPX components must be met. This paper will detail these requirements and provide an overview of the Heating and Cooling System design while focusing on the ramifications of the TPX changes described above

  14. The utilization of excess wind-electric power from stock water pumping systems to heat a sector of the stock tank

    Energy Technology Data Exchange (ETDEWEB)

    Nydahl, J.E.; Carlson, B.O. [Univ. of Wyoming, Laramie, WY (United States)

    1996-12-31

    On the high plains, a wind-electric stock water pumping system produces a significant amount of excess power over the winter months due to intense winds and the decreased water consumption by cattle. The University of Wyoming is developing a multi-tasking system to utilize this excess energy to resistively heat a small sector of the stock tank at its demonstration/experimental site. This paper outlines the detailed heat transfer analysis that predicted drinking water temperature and icing conditions. It also outlines the optimization criteria and the power produced by the Bergey 1500 wind electric system. Results show that heating a smaller insulated tank inserted into the larger tank would raise the drinking water temperature by a maximum of 6.7 {degrees}C and eliminate icing conditions. The returns associated with the additional cattle weight gain, as a result of the consumption of warmer water, showed that system modification costs would be recovered the first year. 12 refs., 11 figs., 2 tabs.

  15. CAREM-25: Residual heat removal system

    International Nuclear Information System (INIS)

    Arvia, Roberto P.; Coppari, Norberto R.; Gomez de Soler, Susana M.; Ramilo, Lucia B.

    2000-01-01

    The objective of this work was the definition and consolidation of the residual heat removal system for the CAREM 25 reactor. The function of this system is cool down the primary circuit, removing the core decay heat from hot stand-by to cold shutdown and during refueling. In addition, this system heats the primary water from the cold shutdown condition to hot stand-by condition during the reactor start up previous to criticality. The system has been designed according to the requirements of the standards: ANSI/ANS 51.1 'Nuclear safety criteria for the design of stationary PWR plants'; ANSI/ANS 58.11 'Design criteria for safe shutdown following selected design basis events in light water reactors' and ANSI/ANS 58.9 'Single failure criteria for light water reactor safety-related fluid systems'. The suggested design fulfills the required functions and design criteria standards. (author)

  16. Potential Energy Flexibility for a Hot-Water Based Heating System in Smart Buildings Via Economic Model Predictive Control

    DEFF Research Database (Denmark)

    Ahmed, Awadelrahman M. A.; Zong, Yi; Mihet-Popa, Lucian

    2017-01-01

    This paper studies the potential of shifting the heating energy consumption in a residential building to low price periods based on varying electricity price signals suing Economic Model Predictive Control strategy. The investigated heating system consists of a heat pump incorporated with a hot...... water tank as active thermal energy storage, where two optimization problems are integrated together to optimize both the heat pump electricity consumption and the building heating consumption. A sensitivity analysis for the system flexibility is examined. The results revealed that the proposed...

  17. FFTF primary heat transport system heating, ventilating and air conditioning system experience

    International Nuclear Information System (INIS)

    Umek, A.M.; Hicks, D.F.; Schweiger, D.L.

    1981-01-01

    FFTF cools its primary/in-containment sodium equipment cells by means of a forced nitrogen cooling system which exchanges heat with a water-glycol system. The nitrogen cooling system is also used to maintain an inert gas atmosphere in the cells containing sodium equipment. Sodium Piping and Components have installed electrical resistance heaters to maintain a minimum sodium temperature and stainless steel jacketed mineral insulation to reduce heat loss. Design features and test results of a comprehensive redesign of the HVAC and insulation system required to support long-term nuclear operations are discussed

  18. Technical project of a solar water heating system for Hostal FRATERNIDAD, Santiago de Cuba

    International Nuclear Information System (INIS)

    Arzuaga Machado, Yusnel; Torres Ten, Alonso; Fonseca Fonseca, Susana; Fuetes lombá, Osmanys; Massipe Hernández, J. Raúl; Gonzalez, Wagner Roberto

    2017-01-01

    It is presented the technical project of a solar water heating system for Hostal FRATERNIDAD, Santiago de Cuba, Cuba, 20 Cabannas type tourism and a one of 2 square meter flat solar collector will be used, with a storage tank of 200 liters capacity, that is to say one system per cabin. (author)

  19. Low-Cost Solar Water Heating Research and Development Roadmap

    Energy Technology Data Exchange (ETDEWEB)

    Hudon, K.; Merrigan, T.; Burch, J.; Maguire, J.

    2012-08-01

    The market environment for solar water heating technology has changed substantially with the successful introduction of heat pump water heaters (HPWHs). The addition of this energy-efficient technology to the market increases direct competition with solar water heaters (SWHs) for available energy savings. It is therefore essential to understand which segment of the market is best suited for HPWHs and focus the development of innovative, low-cost SWHs in the market segment where the largest opportunities exist. To evaluate cost and performance tradeoffs between high performance hot water heating systems, annual energy simulations were run using the program, TRNSYS, and analysis was performed to compare the energy savings associated with HPWH and SWH technologies to conventional methods of water heating.

  20. Long-distance heat transport by hot water

    International Nuclear Information System (INIS)

    Munser, H.; Reetz, B.

    1990-01-01

    From the analysis of the centralized heat supply in the GDR energy-economical and ecological indispensable developments of long-distance heat systems in conurbation are derived. The heat extraction from a nuclear power plant combined with long- distance hot-water transport over about 110 kilometres is investigated and presented as a possibility to perspective base load heat demands for the district around Dresden. By help of industrial-economic, hydraulic and thermic evaluations of first design variants of the transit system the acceptance of this ecologic and energetic preferred solution is proved and requirements for its realization are shown

  1. Solar space and water heating system at Stanford University Central Food Services Building. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1980-05-01

    This active hydronic domestic hot water and space heating system was 840 ft/sup 2/ of single-glazed, liquid, flat plate collectors and 1550 gal heat storage tanks. The following are discussed: energy conservation, design philosophy, operation, acceptance testing, performance data, collector selection, bidding, costs, economics, problems, and recommendations. An operation and maintenance manual and as-built drawings are included in appendices. (MHR)

  2. Compact seasonal PCM heat storage for solar heating systems

    DEFF Research Database (Denmark)

    Dannemand, Mark

    Space heating of buildings and preparation of domestic hot water accounts for a large part of the society’s energy consumption. Solar radiation is an abundant and renewable energy source which can be harvested by solar collectors and used to cover heating demands in the built environment....... The seasonal availability of solar energy does however not match with the heating demands in buildings which typically are large in winter periods when limited solar energy is available. Heat can be stored over a few days in water stores but continuous heat losses limits the storage periods. The possibility...... of storing heat from summer where solar energy is widely available to winter periods where the heating demands are large, allows for implementing more renewable energy in our energy system. The phase change material (PCM) sodium acetate trihydrate (SAT) melts at 58 °C. The melting process requires...

  3. Evaporation and condensation heat transfer in a suppression chamber of the water wall type passive containment cooling system

    International Nuclear Information System (INIS)

    Fujii, Tadashi; Kataoka, Yoshiyuki; Murase, Michio

    1996-01-01

    To evaluate the system pressure response of a water wall type containment cooling system, which is one of the passive safety systems, the evaporation and condensation behaviors in a suppression chamber have been experimentally examined. In the system, the suppression pool water evaporates from the pool surface, passing into the wetwell due to pool temperature rise, while steam in the wetwell condenses on the steel containment vessel wall due to the heat release through the wall. The wetwell is a gas phase region in the suppression chamber and its pressure, which is expressed as the sum of the noncondensable gas pressure and saturated steam pressure, is strongly affected by the evaporation heat transfer from the suppression pool surface and condensation heat transfer on the containment vessel wall. Based on the measured temperature profiles near the heat transfer surface and the wetwell pressure using two apparatuses, evaporation and condensation heat transfer coefficients were evaluated. The following results were obtained. (1) Both heat transfer coefficients increased as the ratio of the steam partial pressure to the total pressure increased. (2) Comparison of the results from two types of test apparatuses confirmed that the size of the heat transfer surface did not affect the heat transfer characteristics within these tests. (3) The heat transfer coefficients were expressed by the ratio of the steam to noncondensable gas logarithmic mean concentration, which considered the steam and gas concentration gradient from the heat transfer surface to the wetwell bulk. (author)

  4. Economic analysis of wind-powered refrigeration cooling/water-heating systems in food processing. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Garling, W.S.; Harper, M.R.; Merchant-Geuder, L.; Welch, M.

    1980-03-01

    Potential applications of wind energy include not only large central turbines that can be utilized by utilities, but also dispersed systems for farms and other applications. The US Departments of Energy (DOE) and Agriculture (USDA) currently are establishing the feasibility of wind energy use in applications where the energy can be used as available, or stored in a simple form. These applications include production of hot water for rural sanitation, heating and cooling of rural structures and products, drying agricultural products, and irrigation. This study, funded by USDA, analyzed the economic feasibility of wind power in refrigeration cooling and water heating systems in food processing plants. Types of plants included were meat and poultry, dairy, fruit and vegetable, and aquaculture.

  5. High pressure, low pressure and hot water heating systems in hospitals. Hochdruck-, Niederdruck- und Warmwasserheizungsanlagen im Krankenhaus

    Energy Technology Data Exchange (ETDEWEB)

    Riedle, K [H. Riedle GmbH, Wiesbaden (Germany)

    1994-07-01

    In hospital nowadays the limitation of the use of steam boilers and their direct supply network to the possible minimum is aimed at when the heating system is exchanged or retrofitted. Independent of the fact whether high pressure or low pressure steam or hot water is used the optimum water treatment should be carried out with a minimum of chemical substances. Here hydroquinone, neutralizing amines, carbohydrazide, sodium sulphite and tannins can be used. The dimensioning of hot water heating circuits is shown with examples. (BWI)

  6. The UK solar water heating industry: a period of development and growth

    International Nuclear Information System (INIS)

    Blower, John

    2001-01-01

    This 2001 edition of the guide to UK renewable energy companies examines the solar water heating sector in the UK and presents an illustration of the layout of a typical solar water heating system. The rising demand for solar water heating and growth in sales especially in the export market are noted. Developments within the UK solar water heating manufacturing industry are considered, and details are given of design and development in innovative policy infrastructure, and the SHINE 21 project supported by the EU's ADAPT programme and the UK Department of Trade and Industry involving collaboration between the solar water heating and plumbing industries. Developments in the new build sectors including in-roof solar collector products and the increasing number of solar water heating systems installed in UK houses are discussed along with the promising future for the market

  7. House-internal heating systems; Husinterna vaermesystem

    Energy Technology Data Exchange (ETDEWEB)

    Johansson, Per-Olof; Wollerstrand, Janusz [Lund Univ. (Sweden). Dept. of Heat and Power Engineering

    2005-07-01

    reduction of heat comfort, increased risk for corrosion, noise and pump damage. To avoid this it is important to remove the air that comes with the water when the system is filled up and that no air is leaking in into the system. This can be avoided by filling the radiator-system with water from the district heating net or with deairated water. The method is put into practice in some Swedish and Nordic heating systems. If the radiator-system is of low temperature type a greater amount of air can be in solution in the water which can cause problem. To avoid this, a permanent air eliminator can be installed, either of a bubble catcher or of a vacuum degasser type. Within the HVAC-branch an interest of filling up the radiator-system with water from the district heating net exists, but to make this possible in a greater extent an interest from the owner of the district heating net is also necessary.

  8. TiO2/water Nanofluid Heat Transfer in Heat Exchanger Equipped with Double Twisted-Tape Inserts

    Science.gov (United States)

    Eiamsa-ard, S.; Ketrain, R.; Chuwattanakul, V.

    2018-05-01

    Nowadays, heat transfer enhancement plays an important role in improving efficiency of heat transfer and thermal systems for numerous areas such as heat recovery processes, chemical reactors, air-conditioning/refrigeration system, food engineering, solar air/water heater, cooling of high power electronics etc. The present work presents the experimental results of the heat transfer enhancement of TiO2/water nanofluid in a heat exchanger tube fitted with double twisted tapes. The study covered twist ratios of twisted tapes (y/w) of 1.5, 2.0, and 2.5) while the concentration of the nanofluid was kept constant at 0.05% by volume. Observations show that heat transfer, friction loss and thermal performance increase as twist ratio (y/w) decreases. The use of the nanofluid in the tube equipped with the double twisted-tapes with the smallest twist ratio (y/w = 1.5) results in the increases of heat transfer rates and friction factor up to 224.8% and 8.98 times, respectively as compared to those of water. In addition, the experimental results performed that double twisted tapes induced dual swirling-flows which played an important role in improving fluid mixing and heat transfer enhancement. It is also observed that the TiO2/water nanofluid was responsible for low pressure loss behaviors.

  9. Effect of heat recovery water heater system on the performance of residential split air conditioner using hydrocarbon refrigerant (HCR22)

    Science.gov (United States)

    Aziz, A.; Thalal; Amri, I.; Herisiswanto; Mainil, A. K.

    2017-09-01

    This This paper presents the performance of residential split air conditioner (RSAC) using hydrocarbon refrigerant (HCR22) as the effect on the use of heat recovery water heater system (HRWHS). In this study, RSAC was modified with addition of dummy condenser (trombone coil type) as heat recovery water heater system (HRWHS). This HRWHS is installed between a compressor and a condenser by absorbing a part of condenser waste heat. The results show that RSAC with HRWHS is adequate to generate hot water with the temperature range about 46.58˚C - 48.81˚C when compared to without HRWHS and the use of dummy condenser does not give significant effect to the split air conditioner performance. When the use of HRWHS, the refrigerant charge has increase about 19.05%, the compressor power consumption has slightly increase about 1.42% where cooling capacity almost the same with slightly different about 0.39%. The condenser heat rejection is lower about 2.68% and the COP has slightly increased about 1.05% when compared to without HRWHS. The use of HRWHS provide free hot water, it means there is energy saving for heating water without negative impact to the system performance of RSAC.

  10. Research and Development Roadmap for Water Heating Technologies

    Energy Technology Data Exchange (ETDEWEB)

    Goetzler, William [Navigant Consulting Inc.; Gagne, Claire [Navigant Consulting Inc.; Baxter, Van D [ORNL; Lutz, James [Lawrence Berkeley National Laboratory (LBNL); Merrigan, Tim [National Renewable Energy Laboratory (NREL); Katipamula, Srinivas [Pacific Northwest National Laboratory (PNNL)

    2011-10-01

    Although water heating is an important energy end-use in residential and commercial buildings, efficiency improvements in recent years have been relatively modest. However, significant advancements related to higher efficiency equipment, as well as improved distribution systems, are now viable. DOE support for water heating research, development and demonstration (RD&D) could provide the impetus for commercialization of these advancements.

  11. Longevity characteristics of flat solar water-heating collectors in hot-water-supply systems. Part 1. Procedure for calculating collector thermal output

    International Nuclear Information System (INIS)

    Avezova, N.R.; Ruziev, O. S.; Suleimanov, Sh. I.; Avezov, R. R.; Vakhidov, A.

    2013-01-01

    A procedure for calculating longevity indices (daily and monthly variations and, hence, annual thermal output) of flat solar water-heating collectors, amount of conditional fuel saved per year by using solar energy, and cost of solar fuel and thermal energy generated in hot-water-supply systems is described. (authors)

  12. Integration of Space Heating and Hot Water Supply in Low Temperature District Heating

    DEFF Research Database (Denmark)

    Elmegaard, Brian; Ommen, Torben Schmidt; Markussen, Michael

    2014-01-01

    pipes, where the water is at the highest temperature. The heat loss may be lowered by decreasing the temperatures in the network for which reason low temperature networks are proposed as a low loss solution for future district heating. However, the heating demand of the consumers involve both domestic......District heating makes it possible to provide heat for many consumers in an efficient manner. In particular, district heating based on combined heat and power production is highly efficient. One disadvantage of district heating is that there is a significant heat loss from the pipes...... to the surrounding ground. In larger networks involving both transmission and distribution systems, the heat loss is most significant from the distribution network. An estimate is that about 80-90 % of the heat loss occurs in the distribution system. In addition, the heat loss is naturally highest from the forward...

  13. Analyzing the optimization of an organic Rankine cycle system for recovering waste heat from a large marine engine containing a cooling water system

    International Nuclear Information System (INIS)

    Yang, Min-Hsiung; Yeh, Rong-Hua

    2014-01-01

    Highlights: • Employing the thermodynamic analysis and a heat-transfer method, an ORC optimization is presented. • An optimal objective parameter evaluation of six working fluids is presented. • Refrigerants with superior thermodynamic properties do not necessary have excellent performance. • Cylinder jacket water temperature strongly affects optimal evaporation temperature. - Abstract: In this study, six working fluids with zero ozone depletion potential and low global warming potential are used in an organic Rankine cycle (ORC) system to recover waste heat from cylinder jacket water of large marine diesel engines. Thermodynamic analysis and a finite-temperature-difference heat-transfer method are developed to evaluate the thermal efficiency, total heat-exchanger area, objective parameter, and exergy destruction of the ORC system. The optimal evaporation and condensation temperatures for achieving the maximal objective parameter, the ratio of net power output to the total heat-transfer area of heat exchangers, of an ORC system are investigated. The results show that, among the working fluids, R600a performs the best in the optimal objective parameter evaluation followed by R1234ze, R1234yf, R245fa, R245ca, and R1233zd at evaporation temperatures ranging from 58 °C to 68 °C and condensation temperatures ranging from 35 °C to 45 °C. The optimal operating temperatures and corresponding thermal efficiency and exergy destruction are proposed. Furthermore, the influences of inlet temperatures on cylinder jacket water and cooling water in the ORC are presented for recovering waste heat. The results of this work were verified with theoretical solutions and experimental results in the literature and it was revealed that they were consistent with them

  14. 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.

  15. Simultaneous Waste Heat and Water Recovery from Power Plant Flue Gases for Advanced Energy Systems

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Dexin [Gas Technology Inst., Des Plaines, IL (United States)

    2016-12-31

    This final report presents the results of a two-year technology development project carried out by a team of participants sponsored by the Department of Energy (DOE). The objective of this project is to develop a membrane-based technology to recover both water and low grade heat from power plant flue gases. Part of the recovered high-purity water and energy can be used directly to replace plant boiler makeup water as well as improving its efficiency, and the remaining part of the recovered water can be used for Flue Gas Desulfurization (FGD), cooling tower water makeup or other plant uses. This advanced version Transport Membrane Condenser (TMC) with lower capital and operating costs can be applied to existing plants economically and can maximize waste heat and water recovery from future Advanced Energy System flue gases with CO2 capture in consideration, which will have higher moisture content that favors the TMC to achieve higher efficiency.

  16. A Study of Ballast Water Treatment Using Engine Waste Heat

    Science.gov (United States)

    Balaji, Rajoo; Yaakob, Omar; Koh, Kho King; Adnan, Faizul Amri bin; Ismail, Nasrudin bin; Ahmad, Badruzzaman bin; Ismail, Mohd Arif bin

    2018-05-01

    Heat treatment of ballast water using engine waste heat can be an advantageous option complementing any proven technology. A treatment system was envisaged based on the ballast system of an existing, operational crude carrier. It was found that the available waste heat could raise the temperatures by 25 °C and voyage time requirements were found to be considerable between 7 and 12 days to heat the high volumes of ballast water. Further, a heat recovery of 14-33% of input energies from exhaust gases was recorded while using a test rig arrangement representing a shipboard arrangement. With laboratory level tests at temperature ranges of around 55-75 °C, almost complete species mortalities for representative phytoplankton, zooplankton and bacteria were observed while the time for exposure varied from 15 to 60 s. Based on the heat availability analyses for harvesting heat from the engine exhaust gases(vessel and test rig), heat exchanger designs were developed and optimized using Lagrangian method applying Bell-Delaware approaches. Heat exchanger designs were developed to suit test rig engines also. Based on these designs, heat exchanger and other equipment were procured and erected. The species' mortalities were tested in this mini-scale arrangement resembling the shipboard arrangement. The mortalities realized were > 95% with heat from jacket fresh water and exhaust gases alone. The viability of the system was thus validated.

  17. Experimental study on fouling in the heat exchangers of surface water heat pumps

    International Nuclear Information System (INIS)

    Bai, Xuelian; Luo, Te; Cheng, Kehui; Chai, Feng

    2014-01-01

    Fouling in the heat exchangers plays a key role on the performance of surface water heat pumps. It is also the basement for the system design criteria and operation energy efficiency. In this paper, experimental measurements are performed both in the field and the laboratory with different water qualities, temperatures and velocities. The research will focus on the dynamic growth characteristics of fouling and its main components. By studying the variation rules of fouling resistance, the fouling resistance allowance for certain water condition is recommended. Furthermore, a fouling prediction model in surface water heat pump will be developed and validated based on elaborating with fouling principle under specified water conditions. - Highlights: • Field and laboratory experiments are taken to measure the fouling variation. • Fouling growth process can be divided into four stages. • We recommend fouling resistance allowances for certain conditions. • A fouling prdiction model is developed and validated

  18. Combined heat and power solar system

    International Nuclear Information System (INIS)

    Anon

    2000-01-01

    An Australian-designed photovoltaic (PV) power system that also supplies hot water is close to commercial release. PVs have been around for decades and solar concentrators have been efficiently heating water for nearly a century. The Australian National University, Department of Engineering - Centre for Sustainable Energy systems (CSES), has designed a domestic scale modular system that not only generates electricity but also provides concentrated thermal energy to heat water for a Solahart hot water system and is designed to be deployed into small to medium scale applications such as hospitals, schools and dwellings with an easily assembled galvanised steel frame. A market research was carried out and is envisaged that at least 7,500 units will be installed annually by the year 2005 and up to 25,000 units by 2008

  19. District heating with SLOWPOKE energy systems

    International Nuclear Information System (INIS)

    Lynch, G.F.

    1988-03-01

    The SLOWPOKE Energy System, a benign nuclear heat source designed to supply 10 thermal megawatts in the form of hot water for local heating systems in buildings and institutions, is at the forefront of these developments. A demonstration unit has been constructed in Canada and is currently undergoing an extensive test program. Because the nuclear heat source is small, operates at atmospheric pressure, and produces hot water below 100 degrees Celcius, intrinsic safety features will permit minimum operator attention and allow the heat source to be located close to the load and hence to people. In this way, a SLOWPOKE Energy System can be considered much like the oil- or coal-fired furnace it is designed to replace. The low capital investment requirements, coupled with a high degree of localization, even for the first unit, are seen as attractive features for the implementation of SLOWPOKE Energy Systems in many countries

  20. An experimental study of trans-critical CO2 water–water heat pump using compact tube-in-tube heat exchangers

    International Nuclear Information System (INIS)

    Jiang, Yuntao; Ma, Yitai; Li, Minxia; Fu, Lin

    2013-01-01

    Highlights: • Thermodynamic analyses of transcritical CO 2 cycle with and without IHX are provided. • A transcritical CO 2 heat pump system adopts compact tube-in-tube heat exchangers. • Experiment results of systems with and without IHX have been analyzed and compared. • IHX can improve the performance of the transcritical CO 2 heat pump system. - Abstract: A transcritical CO 2 water–water heat pump system is introduced in this study, which employs compact tube-in-tube evaporator and gas cooler. Its primary test standards and operating conditions are introduced. Under test conditions, experiments have been carried out with compression cycles with and without internal heat exchanger (IHX). Experiment results have been analyzed and compared, showing that IHX can improve the coefficient of performance of the system. The analyses are done mainly on the variations of outlet CO 2 temperature of the gas cooler, compressor discharge pressure, compressor lubricant temperature, hot water mass flow rate, etc. When the inlet water temperature of the gas cooler is 15 °C, 20 °C, 25 °C respectively, the hot water temperature ranges from 45 °C to 70 °C, the relative COP h (coefficient of performance when heating) change index (RCI COP ) of the heat pump system with IHX is about 3.5–8% higher than that without IHX. The relative capacity change index (RCI Q ) of the heat pump system with IHX is about 5–10% higher than that without IHX. Temperature of CO 2 increases at the outlet of the gas cooler when the outlet water temperature of the gas cooler increases. Lowering the outlet CO 2 temperature of the gas cooler is an important way to improve the performance of the system

  1. Building America Case Study: Side-by-Side Testing of Water Heating Systems: Results from 2013-2014 Evaluation Final Report, Cocoa, FL

    Energy Technology Data Exchange (ETDEWEB)

    Rothgeb, Stacey K [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Colon, C. [BA-PIRC; Martin, E. [BA-PIRC

    2017-08-24

    The Florida Solar Energy Center (FSEC) has completed a fourth year-long evaluation on residential hot water heating systems in a laboratory environment (east central Florida, hot-humid climate). This report contains a summary of research activities regarding the evaluation of two residential electric heat pump water heaters (HPWHs), a solar thermal system utilizing a polymer glazed absorber and a high efficiency natural gas system.

  2. Building America Case Study: Side-by-Side Testing of Water Heating Systems: Results from the 2013–2014 Evaluation Final Report

    Energy Technology Data Exchange (ETDEWEB)

    C. Colon and E. Martin

    2017-08-24

    The Florida Solar Energy Center (FSEC) has completed a fourth year-long evaluation on residential hot water heating systems in a laboratory environment (east central Florida, hot-humid climate). This report contains a summary of research activities regarding the evaluation of two residential electric heat pump water heaters (HPWHs), a solar thermal system utilizing a polymer glazed absorber and a high efficiency natural gas system.

  3. Solar-assisted gas-energy water-heating feasibility for apartments

    Science.gov (United States)

    Davis, E. S.

    1975-01-01

    Studies of residential energy use, solar-energy technology for buildings, and the requirements for implementing technology in the housing industry led to a project to develop a solar water heater for apartments. A design study for a specific apartment was used to establish a solar water-heater cost model which is based on plumbing contractor bids and manufacturer estimates. The cost model was used to size the system to minimize the annualized cost of hot water. The annualized cost of solar-assisted gas-energy water heating is found to be less expensive than electric water heating but more expensive than gas water heating. The feasibility of a natural gas utility supplying the auxiliary fuel is evaluated. It is estimated that gas-utilizing companies will find it profitable to offer solar water heating as part of a total energy service option or on a lease basis when the price of new base-load supplies of natural gas reaches $2.50-$3.00 per million Btu.

  4. Refrigerant charge management in a heat pump water heater

    Science.gov (United States)

    Chen, Jie; Hampton, Justin W.

    2014-06-24

    Heat pumps that heat or cool a space and that also heat water, refrigerant management systems for such heat pumps, methods of managing refrigerant charge, and methods for heating and cooling a space and heating water. Various embodiments deliver refrigerant gas to a heat exchanger that is not needed for transferring heat, drive liquid refrigerant out of that heat exchanger, isolate that heat exchanger against additional refrigerant flowing into it, and operate the heat pump while the heat exchanger is isolated. The heat exchanger can be isolated by closing an electronic expansion valve, actuating a refrigerant management valve, or both. Refrigerant charge can be controlled or adjusted by controlling how much liquid refrigerant is driven from the heat exchanger, by letting refrigerant back into the heat exchanger, or both. Heat pumps can be operated in different modes of operation, and segments of refrigerant conduit can be interconnected with various components.

  5. Solar heating, cooling, and domestic hot water system installed at Kaw Valley State Bank and Trust Company, Topeka, Kansas

    Science.gov (United States)

    1980-01-01

    The building has approximately 5600 square feet of conditioned space. Solar energy was used for space heating, space cooling, and preheating domestic hot water (DHW). The solar energy system had an array of evacuated tube-type collectors with an area of 1068 square feet. A 50/50 solution of ethylene glycol and water was the transfer medium that delivered solar energy to a tube-in-shell heat exchanger that in turn delivered solar heated water to a 1100 gallon pressurized hot water storage tank. When solar energy was insufficient to satisfy the space heating and/or cooling demand, a natural gas-fired boiler provided auxiliary energy to the fan coil loops and/or the absorption chillers. Extracts from the site files, specification references, drawings, and installation, operation and maintenance instructions are presented.

  6. Experimental investigation on the use of water-phase change material storage in conventional solar water heating systems

    Energy Technology Data Exchange (ETDEWEB)

    Al-Hinti, I.; Al-Ghandoor, A.; Maaly, A.; Abu Naqeera, I.; Al-Khateeb, Z.; Al-Sheikh, O. [The Hashemite University, Zarqa 13115 (Jordan)

    2010-08-15

    This paper presents an experimental investigation of the performance of water-phase change material (PCM) storage for use with conventional solar water heating systems. Paraffin wax contained in small cylindrical aluminum containers is used as the PCM. The containers are packed in a commercially available, cylindrical hot water storage tank on two levels. The PCM storage advantage is firstly demonstrated under controlled energy input experiments with the aid of an electrical heater on an isolated storage tank, with and without the PCM containers. It was found that the use of the suggested configuration can result in a 13-14 C advantage in the stored hot water temperature over extended periods of time. The storage performance was also investigated when connected to flat plate collectors in a closed-loop system with conventional natural circulation. Over a test period of 24 h, the stored water temperature remained at least 30 C higher than the ambient temperature. The use of short periods of forced circulation was found to have minimum effect on the performance of the system. Finally, the recovery effect and the storage performance of the PCM was analyzed under open-loop operation patterns, structured to simulate daily use patterns. (author)

  7. Decontamination of drinking water by direct heating in solar panels.

    Science.gov (United States)

    Fjendbo Jørgensen, A J; Nøhr, K; Sørensen, H; Boisen, F

    1998-09-01

    A device was developed for direct heating of water by solar radiation in a flow-through system of copper pipes. An adjustable thermostat valve prevents water below the chosen temperature from being withdrawn. The results show that it is possible to eliminate coliform and thermotolerant coliform bacteria from naturally contaminated river water by heating to temperatures of 65 degrees C or above. Artificial additions of Salmonella typhimurium, Streptococcus faecalis and Escherichia coli to contaminated river water were also inactivated after heating to 65 degrees C and above. The total viable count could be reduced by a factor of 1000. The heat-resistant bacteria isolated from the Mlalakuva River (Tanzania) were spore-forming bacteria which exhibited greater heat resistance than commonly used test bacteria originating from countries with colder climates. To provide a good safety margin it is recommended that an outlet water temperature of 75 degrees C be used. At that temperature the daily production was about 501 of decontaminated water per m2 of solar panel, an amount that could be doubled by using a heat exchanger to recycle the heat.

  8. Investigation and optimisation of heat storage tanks for low-flow SDHW systems[Solar Domestic Hot Water

    Energy Technology Data Exchange (ETDEWEB)

    Knudsen, Soeren

    2004-07-01

    This thesis, 'Investigation and optimisation of heat storage tanks for low-flow SDHW systems', describes a study of the heat transfer and flow structure in vertical mantle heat exchangers for low-flow Solar Domestic Hot Water (SDHW) systems. The heat storage is a key component in SDHW systems and the vertical mantle heat exchanger is one of the most promising heat storage designs for low-flow SDHW systems. The study was carried out using a combination of experimental and numerical methods. Thermal experiments of mantle heat exchangers with different mantle inlet designs showed that the mantle inlet port with advantage can be located a distance from the top of the mantle. Consequently, the mantle heat exchangers marketed today can be improved by changing the mantle inlet position. The heat transfer and flow structure in mantle heat exchangers are rather complex and the thermal experiments were followed by investigations by means of advanced experimental and numerical techniques such as Particle Image Velocimetry (PIV) and Computational Fluid Dynamics (CFD). Using a transparent glass mantle tank, experimental flow visualisation was carried out with a PIV system. The flow structures inside the mantle and inside the tank were visualised and then compared with the flow structures predicted by CFD-models. The investigations showed that the CFD-models were able to model the flow in the mantle and in the tank correctly. The CFD-models were also validated by means of thermal experiments with a steel mantle tank. With the verified CFD-models, a parameter analysis was carried out for differently designed mantle heat exchangers for different typical conditions to reveal how the mantle tank parameters influence the flow structure and heat transfer in mantle heat exchangers. The heat transfer in the mantle near the mantle inlet port showed to be in the mixed convection regime, and as the distance from the inlet increased, natural convection started to dominate. The

  9. Experimental study of heat transfer and pressure drop characteristics of air/water and air-steam/water heat exchange in a polymer compact heat exchanger

    NARCIS (Netherlands)

    Cheng, L.; Geld, van der C.W.M.

    2005-01-01

    Experiments of heat transfer and pressure drop in a polymer compact heat exchanger made of PolyVinyliDene-Fluoride were conducted under various conditions for air/water heat exchange and air-steam/water heat exchange, respectively. The overall heat transfer coefficients of air-steam/water heat

  10. Energetic and financial evaluation of solar assisted heat pump space heating systems

    International Nuclear Information System (INIS)

    Bellos, Evangelos; Tzivanidis, Christos; Moschos, Konstantinos; Antonopoulos, Kimon A.

    2016-01-01

    Highlights: • Four solar heating systems are presented in this work. • Various combinations between solar collectors and heat pumps are presented. • The systems are compared energetically and financially. • The use of PV and an air source heat pump is the best choice financially. • The use of PVT with a water source heat pump is the best solution energetically. - Abstract: Using solar energy for space heating purposes consists an alternative way for substituting fossil fuel and grid electricity consumption. In this study, four solar assisted heat pump heating systems are designed, simulated and evaluated energetically and financially in order to determine the most attractive solution. The use of PV collectors with air source heat pump is compared to the use of FPC, PVT and FPC with PV coupled with a water source heat pump. A sensitivity analysis for the electricity cost is conducted because of the great variety of this parameter over the last years. The final results proved that for electricity cost up to 0.23 €/kW h the use of PV coupled with an air source heat pump is the most sustainable solution financially, while for higher electricity prices the coupling of PVT with an water source heat pump is the best choice. For the present electricity price of 0.2 €/kW h, 20 m"2 of PV is able to drive the air source heat pump with a yearly solar coverage of 67% leading to the most sustainable solution. Taking into account energetic aspects, the use of PVT leads to extremely low grid electricity consumption, fact that makes this technology the most environmental friendly.

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

    International Nuclear Information System (INIS)

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

    2017-01-01

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

  12. 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.

  13. Heat of fusion storage systems for combined solar systems in low energy buildings

    DEFF Research Database (Denmark)

    Schultz, Jørgen Munthe; Furbo, Simon

    2004-01-01

    Solar heating systems for combined domestic hot water and space heating has a large potential especially in low energy houses where it is possible to take full advantage of low temperature heating systems. If a building integrated heating system is used – e.g. floor heating - the supply temperature...... from solid to liquid form (Fig. 1). Keeping the temperature as low as possible is an efficient way to reduce the heat loss from the storage. Furthermore, the PCM storage might be smaller than the equivalent water storage as more energy can be stored per volume. If the PCM further has the possibility...... systems through further improvement of water based storages and in parallel to investigate the potential of using storage designs with phase change materials, PCM. The advantage of phase change materials is that large amounts of energy can be stored without temperature increase when the material is going...

  14. A solar assisted heat-pump dryer and water heater

    International Nuclear Information System (INIS)

    Hawlader, M.N.A.; Chou, S.K.; Jahangeer, K.A.; Rahman, S.M.A.

    2006-01-01

    Growing concern about the depletion of conventional energy resources has provided impetus for considerable research and development in the area of alternative energy sources. A solar assisted heat pump dryer and water heater found to be one of the solutions while exploring for alternative energy sources. The heat pump system is used for drying and water heating applications with the major share of the energy derived from the sun and the ambient. The solar assisted heat pump dryer and water heater has been designed, fabricated and tested. The performance of the system has been investigated under the meteorological conditions of Singapore. The system consists of a variable speed reciprocating compressor, evaporator-collector, storage tank, air cooled condenser, auxiliary heater, blower, dryer, dehumidifier, and air collector. The drying medium used is air and the drying chamber is configured to carry out batch drying of good grains. A water tank connected in series with the air cooled condenser delivers hot water for domestic applications. The water tank also ensures complete condensation of the refrigerant vapour. A simulation program is developed using Fortran language to evaluate the performance of the system and the influence of different variables. The performance indices considered to evaluate the performance of the system are: Solar Fraction (SF), Coefficient of Performance (COP) and Specific Moisture Extraction Rate (SMER). A COP value of 7.5 for a compressor speed of 1800 rpm was observed. Maximum collector efficiencies of 0.86 and 0.81 have been found for evaporator-collector and air collector, respectively. A value of the SMER of 0.79 has been obtained for a load of 20 kg and a compressor speed of 1200 rpm

  15. Role of Solar Water Heating in Multifamily Zero Energy Homes

    Energy Technology Data Exchange (ETDEWEB)

    Aldrich, Robb [Consortium for Advanced Residential Buildings, Norwalk, CT (United States); Williamson, James [Consortium for Advanced Residential Buildings, Norwalk, CT (United States)

    2016-04-08

    Solar domestic hot water (SDHW) systems have been installed on buildings for decades, but because of relatively high costs they have not achieved significant market penetration in most of the country. As more buildings move towards zero net energy consumption, however, many designers and developers are looking more closely at SDHW. In multifamily buildings especially, SDHW may be more practical for several reasons: 1) When designing for zero net energy consumption, solar water heating may be part of the lowest cost approach to meet water heating loads; 2) Because of better scale, SDHW systems in multifamily buildings cost significantly less per dwelling than in single-family homes; 3) Many low-load buildings are moving away from fossil fuels entirely. SDHW savings are substantially greater when displacing electric resistance water heating; and 4) In addition to federal tax incentives, some states have substantial financial incentives that dramatically reduce the costs (or increase the benefits) of SDHW systems in multifamily buildings. With support from the U.S. DOE Building America program, the Consortium for Advanced Residential Buildings (CARB) worked with a developer in western Massachusetts to evaluate a SDHW system on a 12-unit apartment building. Olive Street Development completed construction in spring of 2014, and CARB has been monitoring performance of the water heating systems since May 2014.

  16. Solar energy uses in home water heating systems; Utilizacao da energia solar em sistemas de aquecimento de agua residencial

    Energy Technology Data Exchange (ETDEWEB)

    Basso, Luiz Henrique

    2008-07-01

    The awareness of the importance of the environment has stimulated the study of new energy sources renewed and less pollutant. Amongst these sources, solar energy stands alone for being perennial and clean. The use of solar energy in systems of residential water heating, instead of the electric shower, can compliment the economy of electric energy, based on the Brazilian energy matrix. To know all the factors that influence the operation of a system of water heating by solar energy it is important the determination of its economic and technical viabilities and, distribution targeting in urban and agricultural residences. To evaluate equipment of water heating for solar energy in the region west of the Parana, Brazil, an archetype with similar characteristics to equipment used in residences for two inhabitants was built, to function with natural circulation or thermosyphon and without help of a complementary heating system. The room temperature and the speed of the wind were also evaluated, verifying its influence in the heating system. The equipment revealed technical viability, reaching the minimum temperature of 35 deg C for shower, whenever the solar radiation was above the 3500 W.m{sup -2}, for the majority of the studied days. The system operated without interruptions and it did not need maintenance, except for the monthly glass cleaning. Economic viability was clearly demonstrated since the useful life of the equipment exceeded the period of use to gain its investment. (author)

  17. Development of advanced heat pump (2). Prelimirary test of two-stage compression heat pump. Koseino onreinetsu kyokyu heat pump system no kaihatsu. Dai 2 ho 2dan attsusyuku system shisakuki no yobi jikken kekka

    Energy Technology Data Exchange (ETDEWEB)

    Iwatsubo, Tetsushiro; Saikawa, Michinori; Hamamatsu, Teruhide

    1988-03-01

    A heat pump driven by electricity is one of the excellent electricity utilization systems and is promoted to be widely used. An advanced heat pump has been investigated to enlarge its applications in the field of hot water supply for domestic use which will be competitive with city gas and air conditioning in large scale buildings. An experimental unit with two-stage compression system was designed, which has the multi-function of air conditioning and hot water supply, and the trial system was fabricated. In the design, followings were considered; cooperative operations of two compressors by inverter driving, the temperature conditions of both the air for the air conditioning and the heat source, additional setting of the intermediate heat exchanger. The test operation was carried out with checking the start up procedure, the control sequence and so on. The probability of five operation modes: cooling, heating, hot water supply, cooling/hot water supply, and heating/hot water supply, were confirmed. In the mode of heating/hot water supply the hot water temperature was increased to 65/sup 0/C, the excellent performance in hot water supply was demonstrated. (21 figs, 8 tabs, 1 photo, 5 refs)

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

    International Nuclear Information System (INIS)

    Sun Fangtian; Fu Lin; Zhang Shigang; Sun Jian

    2012-01-01

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

  19. Method and apparatus for enhanced heat recovery from steam generators and water heaters

    Science.gov (United States)

    Knight, Richard A.; Rabovitser, Iosif K.; Wang, Dexin

    2006-06-27

    A heating system having a steam generator or water heater, at least one economizer, at least one condenser and at least one oxidant heater arranged in a manner so as to reduce the temperature and humidity of the exhaust gas (flue gas) stream and recover a major portion of the associated sensible and latent heat. The recovered heat is returned to the steam generator or water heater so as to increase the quantity of steam generated or water heated per quantity of fuel consumed. In addition, a portion of the water vapor produced by combustion of fuel is reclaimed for use as feed water, thereby reducing the make-up water requirement for the system.

  20. Water heating solar system for popular houses; Sistema solar de aquecimento de agua para residencias populares

    Energy Technology Data Exchange (ETDEWEB)

    Mogawer, Tamer; Souza, Teofilo Miguel de [Universidade Estadual Paulista (UNESP), Guaratingueta, SP (Brazil). Centro de Energias Renovaveis], e-mail: teofilo@feg.unesp.br

    2004-07-01

    In this paper we present a case study for the design of a low cost solar heating system for a popular residence in an isolated rural community in the state of Rio Grande do Norte. This scaling can be extended to several rural communities that are in the same situation in Brazil as well as the wider use of solar power between the low-income people who do not have the benefits of electricity in their homes or want to have a lower cost of electricity. In this context, there are very interesting alternatives, among which is the replacement of electric heating bath water by heating by solar energy. According to several sources the electric shower, as it is now simple and extremely cheap, is the villain of the national electrical system. It is used in peak hours of consumption, something like 10% of electric generating capacity installed in Brazil, forcing many industries to switch off the machines because of the high cost of electricity during this period. Using the heating by solar energy, we can reduce consumption of electric shower and also increase the use of clean energy in popular homes and in isolated rural communities. This paper will address the use of solar energy with the basic purpose of heating water for bathing in popular residences and in isolated rural areas, using low cost systems, built with easily materials that is found in any area of the country. (author)

  1. Solar water heating and its prospect for timber drying application

    Energy Technology Data Exchange (ETDEWEB)

    Yin, B T

    1982-01-01

    The technical requirements for timber drying are discussed, and the possibility of using a solar water heating system to substitute for conventional fuel in a modern kiln is looked into from heat transfer considerations. At the moment, conventional fuel is used to generate steam for the heating of air in a kiln. If hot water is to be substitued for steam as the heating medium, the heating coil size required is larger. This size is determined relative to that of a steam coil for similar kiln operating temperatures. 5 references.

  2. Combined Space and Water Heating: Next Steps to Improved Performance

    Energy Technology Data Exchange (ETDEWEB)

    Schoenbauer, B. [NorthernSTAR Building America Partnership, Minneapolis, MN (United States); Bohac, D. [NorthernSTAR Building America Partnership, Minneapolis, MN (United States); Huelman, P. [NorthernSTAR Building America Partnership, Minneapolis, MN (United States)

    2016-07-13

    A combined space- and water-heating (combi) system uses a high-efficiency direct-vent burner that eliminates safety issues associated with natural draft appliances. Past research with these systems shows that using condensing water heaters or boilers with hydronic air handling units can provide both space and water heating with efficiencies of 90% or higher. Improved controls have the potential to reduce complexity and improve upon the measured performance. This project demonstrates that controls can significantly benefit these first-generation systems. Laboratory tests and daily load/performance models showed that the set point temperature reset control produced a 2.1%-4.3% (20-40 therms/year) savings for storage and hybrid water heater combi systems operated in moderate-load homes.

  3. Ground-source heat pump systems in Norway

    International Nuclear Information System (INIS)

    Stene, Joern

    2007-01-01

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

  4. Sanitary hot water consumption patterns in commercial and industrial sectors in South Africa: Impact on heating system design

    International Nuclear Information System (INIS)

    Rankin, R.; Rousseau, P.G.

    2006-01-01

    A large amount of individual sanitary hot water consumers are present in the South African residential sector. This led to several studies being done on hot water consumption patterns in this sector. Large amounts of sanitary hot water are also consumed in the commercial sector in buildings such as hotels and in large residences such as those found in the mining industry. The daily profiles of sanitary hot water consumption are not related to any technical process but rather to human behavior and varying ambient conditions. The consumption of sanitary hot water, therefore, represents a challenge to the electrical utility because it is an energy demand that remains one of the biggest contributors to the undesirable high morning and afternoon peaks imposed on the national electricity supply grid. It also represents a challenge to sanitary hot water system designers because the amount of hot water as well as the daily profile in which it is consumed impacts significantly on system design. This paper deals with hot water consumption in the commercial and industrial sectors. In the commercial sector, we look at hotels and in the industrial sector at large mining residences. Both of them are served by centralized hot water systems. Measured results from the systems are compared to data obtained from previous publications. A comparison is also made to illustrate the impact that these differences will have on sanitary hot water system design. Simulations are conducted for these systems using a simulation program developed in previous studies. The results clearly show significant differences in the required heating and storage capacity for the new profiles. A twin peak profile obtained from previous studies in the residential sector was used up to now in studies of heating demand and system design in commercial buildings. The results shown here illustrate the sanitary hot water consumption profile differs significantly from the twin peaks profile with a very high morning

  5. Thermodynamic analysis of vapor compression heat pump cycle for tap water heating and development of CO_2 heat pump water heater for residential use

    International Nuclear Information System (INIS)

    Saikawa, Michiyuki; Koyama, Shigeru

    2016-01-01

    Highlights: • The ideal vapor compression cycle for tap water heating and its COP were defined. • It was verified theoretically that CO_2 achieves the highest COP for tap water heating. • The prototype of CO_2 heat pump water heater for residential use was developed. • Further COP improvement of CO_2 heat pump water heater was estimated. - Abstract: The ideal vapor compression cycle for tap water heating and its coefficient of performance (COP) have been studied theoretically at first. The ideal cycle is defined as the cycle whose high temperature heat source varies temperature with constant specific heat and other processes are same as the reverse Carnot cycle. The COP upper limit of single stage compression heat pump cycle for tap water heating with various refrigerants such as fluorocarbons and natural refrigerants was calculated. The refrigerant which achieves the highest COP for supplying hot water is CO_2. Next, the prototype of CO_2 heat pump water heater for residential use has been developed. Its outline and experimental results are described. Finally its further possibility of COP improvement has been studied. The COP considered a limit from a technical point of view was estimated about 6.0 at the Japanese shoulder season (spring and autumn) test condition of heating water from 17 °C to 65 °C at 16 °C heat source air temperature (dry bulb)/12 °C (wet bulb).

  6. Solar water heating for aquaculture : optimizing design for sustainability

    Energy Technology Data Exchange (ETDEWEB)

    McDonald, M.; Thwaites, J. [Taylor Munro Energy Systems Inc., Delta, BC (Canada)

    2003-08-01

    This paper presents the results of a solar water heating project at Redfish Ranch, the first Tilapia tropical fish farm in British Columbia. The fish are raised in land-based tanks, eliminating the risk of contamination of local ecosystems. As a tropical species, they requires warm water. Natural gas or propane boilers are typically used to maintain tank temperatures at 26 to 28 degrees C. Redfish Ranch uses solar energy to add heat to the fish tanks, thereby reducing fossil-fuel combustion and greenhouse gas emissions. This unique building-integrated solar system is improving the environmental status of of this progressive industrial operation by offsetting fossil-fuel consumption. The system was relatively low cost, although substantial changes had to be made to the roof of the main building. The building-integrated design of the solar water heating system has reduced operating costs, generated local employment, and shows promise of future activity. As such, it satisfies the main criteria for sustainability. 7 refs.

  7. Comparative Studies of the Operation Method of Solar Energy Water Heating System with Auxiliary Heat Pump Heater%热泵辅助供热太阳能热水系统运行模式对比分析

    Institute of Scientific and Technical Information of China (English)

    林辩启; 罗会龙; 王浩; 田盼雨

    2015-01-01

    太阳能热水系统与热泵辅助供热合理结合可取长补短,有效降低建筑能耗。简要概述了空气源热泵、水源热泵、地源热泵辅助供热太阳能热水系统的结构形式及其运行模式。在此基础上,对比分析了热泵辅助供热太阳能热水系统各种典型运行模式的特点及其适用的应用环境。%The appropriate combination of solar water heating system and heat pump auxiliary heating is an effective way to reduce the building energy consumption. The structure and operation method of solar water heating system with different auxiliary heating, such as air-source heat pump, water-source heat pump, and soil-source heat pump, were introduced briefly. The characteristics of all kinds of solar water heating system with auxiliary heating were compared and analyzed. The suitable application environment of solar water heating system with auxiliary heating was also presented.

  8. SIMS prototype system 1: Design data brochure. [solar heating system

    Science.gov (United States)

    1978-01-01

    A prototype solar heating and hot water system using air as the collector fluid and a pebble bed for heat storage was designed for installation into a single family dwelling. The system, subsystem, and installation requirements are described. System operation and performance are discussed, and procedures for sizing the system to a specific site are presented.

  9. Hot water tank for use with a combination of solar energy and heat-pump desuperheating

    Science.gov (United States)

    Andrews, J.W.

    1980-06-25

    A water heater or system is described which includes a hot water tank having disposed therein a movable baffle to function as a barrier between the incoming volume of cold water entering the tank and the volume of heated water entering the tank which is heated by the circulation of the cold water through a solar collector and/or a desuperheater of a heat pump so as to optimize the manner in which heat is imparted to the water in accordance to the demand on the water heater or system. A supplemental heater is also provided and it is connected so as to supplement the heating of the water in the event that the solar collector and/or desuperheater cannot impart all of the desired heat input into the water.

  10. Hot water tank for use with a combination of solar energy and heat-pump desuperheating

    Science.gov (United States)

    Andrews, John W.

    1983-06-28

    A water heater or system which includes a hot water tank having disposed therein a movable baffle to function as a barrier between the incoming volume of cold water entering the tank and the volume of heated water entering the tank which is heated by the circulation of the cold water through a solar collector and/or a desuperheater of a heat pump so as to optimize the manner in which heat is imparted to the water in accordance to the demand on the water heater or system. A supplemental heater is also provided and it is connected so as to supplement the heating of the water in the event that the solar collector and/or desuperheater cannot impart all of the desired heat input into the water.

  11. Application of cooling with solid dissecants in solar heating and heating water systems; Aplicacion de la refrigeracion con desecantes solidos en sistemas solares de calefaccion y agua caliente sanitaria

    Energy Technology Data Exchange (ETDEWEB)

    Carrillo Andres, A.; Cejudo Lopez, J. M.; Dominguez Munoz, F.; Serrano Casares, F.

    2004-07-01

    Solar thermal systems designed for domestic hot water and space heating, must be dimensioned on a larger scale than for purely domestic hot water. In summer, when there are many days when no heating is required, the oversized collector area leads to frequent stagnancy situations. In order to use the excess of collector area in summer, a solar desiccant cooling system can be integrated in the solar thermal system. This paper study such combination, using computer simulations with the program TRNSYS, Klein(2000). (Author)

  12. Solar systems and heat pumps in operation in Carinthia: results 1994 - 1997

    International Nuclear Information System (INIS)

    Faninger, G.

    1998-04-01

    Solar systems and heat pumps in operation in Carinthia: results 1994 - 1997. Test results from solar systems for swimming pool heating, hot water preparation and space heating as well as heat pumps for hot water preparation, space heating and heat recovery will be reported and assessed collectively. (author)

  13. Packaged solar water heating technology: twenty years of progress

    International Nuclear Information System (INIS)

    Morrison, Graham; Wood, Byard

    2000-01-01

    The world market for packaged solar water heaters is reviewed, and descriptions are given of the different types of solar domestic water heaters (SDWH), design concepts for packaged SDWH, thermosyphon SDWH, evacuated insulation and excavated tube collectors, seasonally biased solar collectors, heat pump water heaters, and photovoltaic water heaters. The consumer market value for SDWHs is explained, and the results of a survey of solar water heating are summarised covering advantages, perceived disadvantages, the relative importance of purchase decision factors, experience with system components, and the most frequent maintenance problems. The durability, reliability, and performance of SDWHs are discussed

  14. Fiscal 1976 Sunshine Project result report. R and D on solar cooling/heating and hot water supply system; 1976 nendo taiyonetsu reidanbo kyuto system no kenkyu seika hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1977-03-01

    This report describes the fiscal 1974-76 research result on solar cooling/heating and hot water supply systems. Research was made on survey and analysis of current R and D states, system analysis, energy impact analysis, installation sites of solar collectors, diffusion policy, profitability, and performance evaluation method. Main research results obtained are as follows. The effect of solar cooling/heating and hot water supply on the Japanese energy demand in 2000 is estimated to be 13% for residences and 5% for the other buildings. Environment pollution derived from solar cooling/heating is extremely less than that from conventional energy quantitatively. The facility cost is estimated to be probably 27,000yen/m{sup 2} in collector cost, and nearly 100,000yen/t in heat storage tank cost. As design data for solar cooling/heating systems, the estimation method of heat collection for every solar radiation rank, performance comparison of honeycomb type collectors, and various data for air heat collection systems are presented. (NEDO)

  15. Heat exchanger for solar water heaters

    Science.gov (United States)

    Cash, M.; Krupnick, A. C.

    1977-01-01

    Proposed efficient double-walled heat exchanger prevents contamination of domestic water supply lines and indicates leakage automatically in solar as well as nonsolar heat sources using water as heat transfer medium.

  16. Flue gas recovery system for natural gas combined heat and power plant with distributed peak-shaving heat pumps

    International Nuclear Information System (INIS)

    Zhao, Xiling; Fu, Lin; Wang, Xiaoyin; Sun, Tao; Wang, Jingyi; Zhang, Shigang

    2017-01-01

    Highlights: • A flue gas recovery system with distributed peak-shaving heat pumps is proposed. • The system can improve network transmission and distribution capacity. • The system is advantageous in energy saving, emission reduction and economic benefits. - Abstract: District heating systems use distributed heat pump peak-shaving technology to adjust heat in secondary networks of substations. This technology simultaneously adjusts the heat of the secondary network and reduces the return-water temperature of the primary network by using the heat pump principle. When optimized, low temperature return-water is able to recycle more waste heat, thereby further improving the heating efficiency of the system. This paper introduces a flue gas recovery system for a natural gas combined heat and power plant with distributed peak-shaving heat pumps. A pilot system comprising a set of two 9F gas-steam combined cycle-back pressure heating units was used to analyse the system configuration and key parameters. The proposed system improved the network transmission and distribution capacity, increased heating capacity, and reduced heating energy consumption without compromising heating safety issues. As such, the proposed system is advantageous in terms of energy saving, emission reduction, and economic benefits.

  17. Efficiency improvement of a concentrated solar receiver for water heating system using porous medium

    Science.gov (United States)

    Prasartkaew, Boonrit

    2018-01-01

    This experimental study aims at investigating on the performance of a high temperature solar water heating system. To approach the high temperature, a porous-medium concentrated solar collector equipped with a focused solar heliostat were proposed. The proposed system comprised of two parts: a 0.7x0.7-m2 porous medium receiver, was installed on a 3-m tower, and a focused multi-flat-mirror solar heliostat with 25-m2 aperture area. The porous medium used in this study was the metal swarf or metal waste from lathing process. To know how the system efficiency could be improved by using such porous medium, the proposed system with- and without-porous medium were tested and the comparative study was performed. The experimental results show that, using porous medium for enhancing the heat transfer mechanism, the system thermal efficiency was increased about 25%. It can be concluded that the efficiency of the proposed system can be substantially improved by using the porous medium.

  18. Analysis of economic and environmental benefits of a new heat pump air conditioning system with a heat recovery device

    Science.gov (United States)

    Li, lingxue

    2017-08-01

    The paper designs a new wind-water cooling and heating water conditioner system, connects cooling tower with heat recovery device, which uses cooling water to completely remove the heat that does not need heat recollection, in order to ensure that the system can work efficiently with higher performance coefficient. After the test actual engineering operation, the system’s maximum cooling coefficient of performance can reach 3.5. Its maximum comprehensive coefficient of performance can reach 6.5. After the analysis of its economic and environmental, we conclude that the new system can save 89822 kw per year. It reflects energy-saving and environmental benefits of the cold and hot water air conditioning system.

  19. Water extraction from high moisture lignite by means of efficient integration of waste heat and water recovery technologies with flue gas pre-drying system

    International Nuclear Information System (INIS)

    Han, Xiaoqu; Yan, Junjie; Karellas, Sotirios; Liu, Ming; Kakaras, Emmanuel; Xiao, Feng

    2017-01-01

    Highlights: • Energy-saving potential of FPLPS in different cold-ends and lignite types is evaluated. • Water-saving of FPLPS is realized through recovery of water extracted from lignite. • Integrations of low pressure economizer and spray tower with FPLPS are proposed. • Thermodynamic and economic performances of different schemes are investigated. - Abstract: The flue gas pre-dried lignite-fired power system (FPLPS) integrates the fan mill flue gas dryer with an open pulverizing system and yields an increase of the boiler efficiency. Particularly, the dryer exhaust gas contains a large amount of vapor removed from high moisture lignite, which exhibits great potential for waste heat and water recovery. Two available options are considered to realize the extraction of water from lignite: the low pressure economizer (LPE) for water-cooled units and the spray tower (SPT) integrated with heat pump for air-cooled units. This paper aims at evaluating the energy saving and water recovery potentials of the FPLPS integrated with both schemes. Results showed that the plant efficiency improvement of the FPLPS at base case varied from 1.14% to 1.47% depending on the moisture content of raw lignite. The water recovery ratio and plant efficiency improvement in the optimal LPE scheme were 39.4% and 0.20%, respectively. In contrast, 83.3% of water recover ratio and 110.6 MW_t_h heat supply were achieved in the SPT system. Both schemes were economically feasible with discounted payback periods of around 3 years. Moreover, parametric analysis was conducted to examine the economic viability of both schemes with different lignite types and market factors.

  20. Temperature distribution of a hot water storage tank in a simulated solar heating and cooling system

    Science.gov (United States)

    Namkoong, D.

    1976-01-01

    A 2,300-liter hot water storage tank was studied under conditions simulating a solar heating and cooling system. The initial condition of the tank, ranging from 37 C at the bottom to 94 C at the top, represented a condition midway through the start-up period of the system. During the five-day test period, the water in the tank gradually rose in temperature but in a manner that diminished its temperature stratification. Stratification was found not to be an important factor in the operation of the particular solar system studied.

  1. Exploration of Impinging Water Spray Heat Transfer at System Pressures Near the Triple Point

    Science.gov (United States)

    Golliher, Eric L.; Yao, Shi-Chune

    2013-01-01

    The heat transfer of a water spray impinging upon a surface in a very low pressure environment is of interest to cooling of space vehicles during launch and re-entry, and to industrial processes where flash evaporation occurs. At very low pressure, the process occurs near the triple point of water, and there exists a transient multiphase transport problem of ice, water and water vapor. At the impingement location, there are three heat transfer mechanisms: evaporation, freezing and sublimation. A preliminary heat transfer model was developed to explore the interaction of these mechanisms at the surface and within the spray.

  2. Design of a Heat Pump Assisted Solar Thermal System

    OpenAIRE

    Krockenberger, Kyle G.; DeGrove, John M.; Hutzel, William J.; Foreman, J. Christopher

    2014-01-01

    This paper outlines the design of an active solar thermal loop system that will be integrated with an air source heat pump hot water heater to provide highly efficient heating of a water/propylene glycol mixture. This system design uses solar energy when available, but reverts to the heat pump at night or during cloudy weather. This new design will be used for hydronic heating in the Applied Energy Laboratory, a teaching laboratory at Purdue University, but it is more generally applicable for...

  3. Solar hot-water generation and heating - Kombi-Kompakt+

    International Nuclear Information System (INIS)

    Haller, M.; Vogelsanger, P.

    2005-01-01

    This final report for the Swiss Federal Office of Energy (SFOE) describes new testing facilities at the Institute for Solar Technology in Rapperswil, Switzerland, that allow the testing of solar systems the whole year through. The systems tested feature the combined generation of heat for hot water storage vessels and heat for space heating. The test method used, the Concise Cycle Test (CCT) is described. The results of tests made on a large number of systems demonstrate that it is especially important to have a test system that allows the solar market to be protected from unsatisfactory systems. Good co-operation with manufactures is noted. As the test method includes tests with secondary energy sources such as oil or gas, certain problems in this area were discovered and corrected. Further tests are to be made with systems using biomass as a secondary source of heat

  4. A passive emergency heat sink for water-cooled reactors with particular application to CANDU reactors

    International Nuclear Information System (INIS)

    Spinks, N.J.

    1996-01-01

    Water in an overhead pool can serve as a general-purpose passive emergency heat sink for water-cooled reactors. It can be used for containment cooling, for emergency depressurization of the heat transport-system, or to receive any other emergency heat, such as that from the CANDU moderator. The passive emergency water system provides in-containment depressurization of steam generators and no other provision is needed for supply of low-pressure emergency water to the steam generators. For containment cooling, the pool supplies water to the tube side of elevated tube banks inside containment. The elevation with respect to the reactor heat source maximizes heat transport, by natural convection, of hot containment gases. This effective heat transport combines with the large heat-transfer coefficients of tube banks, to reduce containment overpressure during accidents. Cooled air from the tube banks is directed past the break in the heat-transport system, to facilitate removal of hydrogen using passive catalytic recombiners. (author)

  5. The annual number of days that solar heated water satisfies a specified demand temperature

    Energy Technology Data Exchange (ETDEWEB)

    Yohanis, Y.G. [Thermal Systems Engineering Group, Faculty of Engineering, University of Ulster, BT37 0QB Northern Ireland (United Kingdom); Popel, O.; Frid, S.E. [Non-traditional Renewable Energy Sources, Institute for High Temperatures, Russian Academy of Sciences, 13/19 Izhorskaya str., IVTAN, Moscow 127412 (Russian Federation); Norton, B. [Dublin Institute of Technology, Aungier Street, Dublin 2 (Ireland)

    2006-08-15

    An analysis of solar water heating systems determines the number of days in each month when solar heated water wholly meets demand above a set temperature. The approach has been used to investigate the potential contribution to water heating loads of solar water heating in two UK locations. Correlations between the approach developed and the use of solar fractions are discussed. (author)

  6. Experimental and theoretic investigations of thermal behavior of a seasonal water pit heat storage

    DEFF Research Database (Denmark)

    Fan, Jianhua; Huang, Junpeng; Chatzidiakos, Angelos

    Seasonal heat storages are considered essential for district heating systems because they offer flexibility for the system to integrate different fluctuating renewable energy sources. Water pit thermal storages (PTES) have been successfully implemented in solar district heating plants in Denmark....... Thermal behavior of a 75,000 m3 water pit heat storage in Marstal solar heating plant was investigated experimentally and numerically. Temperatures at different levels of the water pit storage and temperatures at different depths of the ground around the storage were monitored and analyzed. A simulation...... model of the water pit storage is built to investigate development of temperatures in and around the storage. The calculated temperatures are compared to the monitored temperatures with an aim to validate the simulation model. Thermal stratification in the water pit heat storage and its interaction...

  7. Liquid-Metal/Water Direct Contact Heat Exchange: Flow Visualization, Flow Stability, and Heat Transfer Using Real-Time X-Ray Imaging

    International Nuclear Information System (INIS)

    Abdulla, Sherif H.; Liu Xin; Anderson, Mark H.; Bonazza, Riccardo; Corradini, Michael L.; Cho, Dae; Page, Richard

    2005-01-01

    Advanced reactor system designs are being considered with liquid-metal cooling connected to a steam power cycle. In addition, current reactor safety systems are considering auxiliary cooling schemes that assure ex-vessel debris coolability utilizing direct water injection into molten material pools to achieve core quenching and eventual coolability. The phenomenon common in both applications is direct contact heat exchange. The current study focuses on detailed measurements of liquid-metal/water direct contact heat exchange that is directly applicable to improvements in effective heat transfer in devices that are being considered for both of these purposes.In this study, a test facility was designed at the University of Wisconsin-Madison to map the operating range of liquid-metal/water direct contact heat exchange. The test section (184-cm height, 45.75-cm width, and 10-cm depth) is a rectangular slice of a larger heat exchange device. This apparatus was used not only to provide measurements of integral thermal performance (i.e., volumetric heat transfer coefficient), but also local heat transfer coefficients in a bubbly flow regime with X-ray imaging based on measured parameters such as bubble formation time, bubble rise velocity, and bubble diameters.To determine these local heat transfer coefficients, a complete methodology of the X-ray radiography for two-phase flow measurement has been developed. With this methodology, a high-energy X-ray imaging system is optimized for our heat exchange experiments. With this real-time, large-area, high-energy X-ray imaging system, the two-phase flow was quantitatively visualized. An efficient image processing strategy was developed by combining several optimal digital image-processing algorithms into a software computational tool written in MATLAB called T-XIP. Time-dependent heat transfer-related variables such as bubble volumes and velocities, were determined. Finally, an error analysis associated with these measurements

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

    International Nuclear Information System (INIS)

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

    2014-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    1980-01-01

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

  10. Residential hot water distribution systems: Roundtablesession

    Energy Technology Data Exchange (ETDEWEB)

    Lutz, James D.; Klein, Gary; Springer, David; Howard, Bion D.

    2002-08-01

    Residential building practice currently ignores the lossesof energy and water caused by the poor design of hot water systems. Theselosses include: combustion and standby losses from water heaters, thewaste of water (and energy) while waiting for hot water to get to thepoint of use; the wasted heat as water cools down in the distributionsystem after a draw; heat losses from recirculation systems and thediscarded warmth of waste water as it runs down the drain. Severaltechnologies are available that save energy (and water) by reducing theselosses or by passively recovering heat from wastewater streams and othersources. Energy savings from some individual technologies are reported tobe as much as 30 percent. Savings calculations of prototype systemsincluding bundles of technologies have been reported above 50 percent.This roundtable session will describe the current practices, summarizethe results of past and ongoing studies, discuss ways to think about hotwater system efficiency, and point to areas of future study. We will alsorecommend further steps to reduce unnecessary losses from hot waterdistribution systems.

  11. Exergy analysis of an experimental heat transformer for water purification

    International Nuclear Information System (INIS)

    Rivera, W.; Huicochea, A.; Martinez, H.; Siqueiros, J.; Juarez, D.; Cadenas, E.

    2011-01-01

    First and second law of thermodynamics have been used to analyze the performance of an experimental heat transformer used for water purification. The pure water is produced in the auxiliary condenser delivering an amount of heat, which is recycled into the heat transformer increasing the heat source temperatures and also the internal, external and exergy coefficients of performance. The theoretical and experimental study was divided into two parts. In the first part, a second law analysis was carried out to the experimental system showing that the absorber and the condenser are the components with the highest irreversibilities. In the second part, with the results obtained from the second law analysis, new test runs were carried out at similar conditions than the former but varying only one selected temperature at the time. Comparing the COP (coefficient of performance) between the old and new test runs, it was shown that higher internal, external and exergy coefficients of performance were obtained in all the new test runs. Also it was shown that the ECOP (exergy coefficient of performance) increases with an increment of the amount of the purified water produced and with the decrease of the flow ratio. -- Research highlights: → By the first time an experimental results of a heat transformer for water purification with heat recycling has been presented. → An exergy analysis has been carried out in order to identify the irreversibilities in the main components of the system. → With the results obtained of the second law analysis new experimental test runs were carried out minimizing the system irreversibilities and furthermore increasing the system efficiency.

  12. Preliminary Analysis on Heat Removal Capacity of Passive Air-Water Combined Cooling Heat Exchanger Using MARS

    International Nuclear Information System (INIS)

    Kim, Seung-Sin; Jeon, Seong-Su; Hong, Soon-Joon; Bae, Sung-Won; Kwon, Tae-Soon

    2015-01-01

    Current design requirement for working time of PAFS heat exchanger is about 8 hours. Thus, it is not satisfied with the required cooling capability for the long term SBO(Station Black-Out) situation that is required to over 72 hours cooling. Therefore PAFS is needed to change of design for 72 hours cooling. In order to acquirement of long terms cooling using PAFS, heat exchanger tube has to be submerged in water tank for long time. However, water in the tank is evaporated by transferred heat from heat exchanger tubes, so water level is gradually lowered as time goes on. The heat removal capacity of air cooling heat exchanger is core parameter that is used for decision of applicability on passive air-water combined cooling system using PAFS in long term cooling. In this study, the development of MARS input model and plant accident analysis are performed for the prediction of the heat removal capacity of air cooling heat exchanger. From analysis result, it is known that inflow air velocity is the decisive factor of the heat removal capacity and predicted air velocity is lower than required air velocity. But present heat transfer model and predicted air velocity have uncertainty. So, if changed design of PAFS that has over 4.6 kW heat removal capacity in each tube, this type heat exchanger can be applied to long term cooling of the nuclear power plant

  13. Study and optimization of operating regimes of NPP district heating system

    International Nuclear Information System (INIS)

    Bunin, V.S.; Vasil'ev, M.K.; Kudryavtsev, A.A.; Gorbashev, Yu.B.; Gadzhij, V.M.

    1980-01-01

    Thermal tests of the system with two reactors and four turbines have been carried out for the purpose of verification of operating regimes of the NPP district heating system with boiling single-curcuit RBMK-1000 reactors and K-500-65/3000 turbines. The system is designed for heat supply of habitable settlement and industrial site. The data processing have been carried out by the BESM-6 computer representing distributions of heat flow, steam, water and their parameters and determining the main energy indices of the system. Calculations of the system operating regime variables during the year have been carried out with the help of this program. It has been expected that the system provided heat consumption of 232 MW at calculated regime of thermal loading of the district, temperature regime of the system water of 130/170 deg C, relative load of hot water supply of 0.2 and duration of heating period of 4800 h. Calculations demonstrated that distric heat supply by NPP allowed one to supplant about 85 thous. of reference fuel/year of organic fuel. About 63 thous. of reference fuel/year are required for compensation of decrease of electric energy production in a condensation cycle. It has been also shown, that replacing the four-stroke system heaters by one-stroke heaters permits to drop system water underheating 1.5 times and, respectively, electric energy underproduction to 72 mln Mj (20 mln, kWxh). It produces additional economy of 6.6 thous. reference fuel/year. Calculations of its heat system have been conducted in order to determine the influence of water consumption in an intermediate circuit on the system efficiency. It has been shown that with the increase of water consumption energy power losses decrease. Thus, the above studied have demonstrated that the use of the single-circuit NPP district heating systems leads to considerable economy of fuel

  14. Control challenges in domestic heating systems

    DEFF Research Database (Denmark)

    Thybo, Honglian; Larsen, Lars F. S.; Weitzmann, Peter

    2007-01-01

    The objective of this paper is to analyze domestic heating applications and identify unfavorable building constructions and control challenges to be addressed by high performance heating control systems. Heating of domestic houses use a large amount of the total energy consumption in Scandinavia....... Hence the potential of reducing energy consumption by applying high performance control is vast. Indoor climate issues are becoming more in focus, which also leads to a demand for high performance heating systems. The paper presents an analysis of how the building elements of today's domestic houses...... with water based floor heating affect the control challenge. The analysis is documented with simulation results....

  15. Geothermal district heating system feasibility analysis, Thermopolis, Wyoming

    Energy Technology Data Exchange (ETDEWEB)

    Goering, S.W.; Garing, K.L.; Coury, G.; Mickley, M.C.

    1982-04-26

    The purpose of this study is to determine the technical and economic feasibility of constructing and operating a district heating system to serve the residential, commercial, and public sectors in Thermopolis. The project geothermal resource assessment, based on reviews of existing information and data, indicated that substantial hot water resources likely exist in the Rose Dome region 10 miles northeast of Thermopolis, and with quantities capable of supporting the proposed geothermal uses. Preliminary engineering designs were developed to serve the space heating and hot water heating demands for buildings in the Thermopolis-East Thermopolis town service area. The heating district design is based on indirect geothermal heat supply and includes production wells, transmission lines, heat exchanger units, and the closed loop distribution and collection system necessary to serve the individual customers. Three options are presented for disposal of the cooled waters-reinjection, river disposal, and agricultural reuse. The preliminary engineering effort indicates the proposed system is technically feasible. The design is sized to serve 1545 residences, 190 businesses, and 24 public buildings. The peak design meets a demand of 128.2 million Btu at production rates of 6400 gpm.

  16. Investigation af a solar heating system for space heating and domestic hot water supply with a high degree of coverage

    DEFF Research Database (Denmark)

    Vejen, Niels Kristian

    1999-01-01

    A solar storage tank for space heating and domestic hot water supply was designed and testet in af laboratory test facility.......A solar storage tank for space heating and domestic hot water supply was designed and testet in af laboratory test facility....

  17. Flow film boiling heat transfer in water and Freon-113

    International Nuclear Information System (INIS)

    Liu, Qiusheng; Shiotsu, Masahiro; Sakurai, Akira

    2002-01-01

    Experimental apparatus and method for film boiling heat transfer measurement on a horizontal cylinder in forced flow of water and Freon-113 under pressurized and subcooled conditions were developed. The experiments of film boiling heat transfer from single horizontal cylinders with diameters ranging from 0.7 to 5 mm in saturated and subcooled water and Freon-113 flowing upward perpendicular to the cylinders were carried out for the flow velocities ranging from 0 to 1 m/s under system pressures ranging from 100 to 500 kPa. Liquid subcoolings ranged from 0 to 50 K, and the cylinder surface superheats were raised up to 800 K for water and 400 K for Freon-113. The film boiling heat transfer coefficients obtained were depended on surface superheats, flow velocities, liquid subcoolings, system pressures and cylinder diameters. The effects of these parameters were systematically investigated under wider ranges of experimental conditions. It was found that the heat transfer coefficients are higher for higher flow velocities, subcoolings, system pressures, and for smaller cylinder diameters. The observation results of film boiling phenomena were obtained by a high-speed video camera. A new correlation for subcooled flow film boiling heat transfer was derived by modifying authors' correlation for saturated flow film boiling heat transfer with authors' experimental data under wide subcooled conditions. (author)

  18. Vapor compression heat pump system field tests at the tech complex

    Science.gov (United States)

    Baxter, Van D.

    1985-11-01

    The Tennessee Energy Conservation In Housing (TECH) complex has been utilized since 1977 as a field test site for several novel and conventional heat pump systems for space conditioning and water heating. Systems tested include the Annual Cycle Energy System (ACES), solar assisted heat pumps (SAHP) both parallel and series, two conventional air-to-air heat pumps, an air-to-air heat pump with desuperheater water heater, and horizontal coil and multiple shallow vertical coil ground-coupled heat pumps (GCHP). A direct comparison of the measured annual performance of the test systems was not possible. However, a cursory examination revealed that the ACES had the best performance, however, its high cost makes it unlikely that it will achieve wide-spread use. Costs for the SAHP systems are similar to those of the ACES but their performance is not as good. Integration of water heating and space conditioning functions with a desuperheater yielded significant efficiency improvement at modest cost. The GCHP systems performed much better for heating than for cooling and may well be the most efficient alternative for residences in cold climates.

  19. Radiant Heating and Cooling Systems. Part one

    DEFF Research Database (Denmark)

    Kim, Kwan Woo; Olesen, Bjarne W.

    2015-01-01

    The use of radiant heating systems has several thousand years of history.1,2 The early stage of radiant system application was for heating purposes, where hot air from flue gas (cooking, fires) was circulated under floors or in walls. After the introduction of plastic piping water-based radiant...

  20. Summer Indoor Heat Pump Water Heater Evaluation in a Hot-Dry Climate

    Energy Technology Data Exchange (ETDEWEB)

    Hoeschele, Marc [National Renewable Energy Lab. (NREL), Golden, CO (United States); Seitzler, Matthew [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2017-05-01

    Heat pump water heaters offer a significant opportunity to improve water heating performance for the over 40% of U.S. households that heat domestic hot water using electric resistance storage water heaters. Numerous field studies have also been completed documenting performance in a variety of climates and applications. More recent evaluation efforts have focused attention on the performance of May through September 2014, with ongoing winter monitoring being sponsored by California utility partners. Summer results show favorable system performance with extrapolated annual water heating savings of 1,466 to 2,300 kWh per year, based on the observed hot water loads. Additional summer space cooling benefits savings of 121 to 135 kWh per year were projected, further increasing the water energy savings.

  1. Design aspects of commercial open-loop heat pump systems

    Energy Technology Data Exchange (ETDEWEB)

    Rafferty, Kevin

    2000-01-01

    Open loop (or groundwater heat pump systems are the oldest of the ground-source systems. Common design variations include direct (groundwater used directly in the heat pump units), indirect (building loop isolated with a plate heat exchanger), and standing column (water produced and returned to the same well). Direct systems are typically limited to the smallest applications. Standing column systems are employed in hard rock geology sites where it is not possible to produce sufficient water for a conventional system. Due to its greater potential application, this paper reviews key design aspects of the indirect approach. The general design procedure is reviewed, identification of optimum groundwater flow, heat exchanger selection guidelines, well pump control, disposal options, well spacing, piping connections and related issues.

  2. Design Aspects of Commerical Open-Loop Heat Pump Systems

    Energy Technology Data Exchange (ETDEWEB)

    Rafferty, Kevin

    2001-03-01

    Open loop (or groundwater heat pump systems are the oldest of the ground-source systems. Common design variations include direct (groundwater used directly in the heat pump units), indirect (building loop isolated with a plate heat exchanger), and standing column (water produced and returned to the same well). Direct systems are typically limited to the smallest applications. Standing column systems are employed in hard rock geology sites where it is not possible to produce sufficient water for a conventional system. Due to its greater potential application, this paper reviews key design aspects of the indirect approach. The general design procedure is reviewed, identification of optimum groundwater flow, heat exchanger selection guidelines, well pump control, disposal options, well spacing, piping connections and related issues.

  3. Solar heating, cooling, and domestic hot water system installed at Kaw Valley State Bank and Trust Company, Topeka, Kansas. Final report

    Energy Technology Data Exchange (ETDEWEB)

    None

    1980-11-01

    The building has approximately 5600 square feet of conditioned space. Solar energy is used for space heating, space cooling, and preheating domestic hot water (DHW). The solar energy system has an array of evacuated tube-type collectors with an area of 1068 square feet. A 50/50 solution of ethylene glycol and water is the transfer medium that delivers solar energy to a tube-in-shell heat exchanger that in turn delivers solar-heated water to a 1100 gallon pressurized hot water storage tank. When solar energy is insufficient to satisfy the space heating and/or cooling demand, a natural gas-fired boiler provides auxiliary energy to the fan coil loops and/or the absorption chillers. Extracts from the site files, specification references, drawings, and installation, operation and maintenance instructions are included.

  4. Transient Performance of Air-cooled Condensing Heat Exchanger in Long-term Passive Cooling System during Decay Heat Load

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Myoung Jun; Lee, Hee Joon [Kookmin University, Seoul (Korea, Republic of); Moon, Joo Hyung; Bae, Youngmin; Kim, Young-In [KAERI, Daejeon (Korea, Republic of)

    2015-05-15

    In the event of a 'loss of coolant accident'(LOCA) and a non-LOCA, the secondary passive cooling system would be activated to cool the steam in a condensing heat exchanger that is immersed in an emergency cooldown tank (ECT). Currently, the capacities of these ECTs are designed to be sufficient to remove the sensible and residual heat from the reactor coolant system for 72 hours after the occurrence of an accident. After the operation of a conventional passive cooling system for an extended period, however, the water level falls as a result of the evaporation from the ECT, as steam is emitted from the open top of the tank. Therefore, the tank should be refilled regularly from an auxiliary water supply system when the system is used for more than 72 hours. Otherwise, the system would fail to dissipate heat from the condensing heat exchanger due to the loss of the cooling water. Ultimately, the functionality of the passive cooling system would be seriously compromised. As a passive means of overcoming the water depletion in the tank, Kim et al. applied for a Korean patent covering the concept of a long-term passive cooling system for an ECT even after 72 hours. This study presents transient performance of ECT with installing air-cooled condensing heat exchanger under decay heat load. The cooling capacity of an air-cooled condensing heat exchanger was evaluated to determine its practicality.

  5. The relation of collector and storage tank size in solar heating systems

    International Nuclear Information System (INIS)

    Çomaklı, Kemal; Çakır, Uğur; Kaya, Mehmet; Bakirci, Kadir

    2012-01-01

    Highlights: ► A storage tank is used in many solar water heating systems for the storage of hot water. ► Using larger storage tanks decrease the efficiency and increases the cost of the system. ► The optimum tank size for the collector area is very important for economic solar heating systems. ► The optimum sizes of the collectors and the storage tank are determined. - Abstract: The most popular method to benefit from the solar energy is to use solar water heating systems since it is one of the cheapest way to benefit from the solar energy. The investment cost of a solar water heating system is very low, and the maintenance costs are nearly zero. Using the solar energy for solar water heating (SWH) technology has been greatly improved during the past century. A storage tank is used in many solar water heating systems for the conservation of heat energy or hot water for use when some need it. In addition, domestic hot water consumption is strongly variable in many buildings. It depends on the geographical situation, also on the country customs, and of course on the type of building usage. Above all, it depends on the inhabitants’ specific lifestyle. For that reason, to provide the hot water for consumption at the desirable temperature whenever inhabitants require it, there must be a good relevance between the collectors and storage tank. In this paper, the optimum sizes of the collectors and the storage tank are determined to design more economic and efficient solar water heating systems. A program has been developed and validated with the experimental study and environmental data. The environmental data were obtained through a whole year of operation for Erzurum, Turkey.

  6. Demonstration test on the heat pump system, thermally utilizing the domestic waste water. Result of the collecting test on an air conditioning system, Hokkaido Electric Power Gymnasium, Tomari; Seikatsu haisui netsuriyo heat pump system jissho shiken. Tomari Hokuden taiikukan reidanbo system no sainetsu shiken kekka ni tsuite

    Energy Technology Data Exchange (ETDEWEB)

    Honma, T; Yamada, K; Watanabe, K [Hokkaido Electric Power Co. Inc., Sapporo (Japan)

    1995-06-14

    A heat pump system utilizing the domestic waste water was introduced into a gymnasium owned by Hokkaido Electric Power to elucidate the applicability of domestic waste water as a thermal source of heat pump in the cold region. The gymnasium is a two-storied concrete building with the floor space of 2292m{sup 2}. Ground water at temperatures from 10 to 20{degree}C is utilized for the water supply. Made to flow together as waste water, the dirty water and daily exhaust water are discharged at the rate of 100t/day into a river after passing through the septic tank. Higher by 5 to 15{degree}C than the atmospheric temperature, the discharging temperature is kept higher than 10{degree}C even during the very cold period. The domestic waste water is almost neutral in pH, and normal in both SS and BOD. The heat pump was utilized for two stages, i.e., thermal collection and temperature heightening. The capacity of a sewage storage tank tank was made to be 170m{sup 3} to meet the thermal load of 139000kcal/h in the gymnasium. The temperature of 15{degree}C could be kept during the air heating trial. The system is about 2 in coefficient of performance. The K-value of heat exchanger decreased by about 30% after seven months of operation. Upon its overhauling, its K-value recovered to 2.37, so that it must be overhauled once a year. 5 refs., 15 figs. 4 tabs.

  7. Heat exchanger with dirt separator for the use of the heat energy of waste water

    Energy Technology Data Exchange (ETDEWEB)

    1975-11-13

    Well-known heat exchanger systems consist of separate heat exchangers and dirt separators. In the case here in question both devices form a unit. A finned tube heat exchanger is positioned in the center of the dirt separator and is given extra protection through deflection sheets. A safety overflow is supplied so that no residue can appear in the waste water line when decanting.

  8. Compact interior heat exchangers for CO{sub 2} mobile heat pumping systems

    Energy Technology Data Exchange (ETDEWEB)

    Hafner, Armin

    2003-07-01

    The natural refrigerant carbon dioxide (CO{sub 2}) offers new possibilities for design of flexible, efficient and environmentally safe mobile heat pumping systems. As high-efficient car engines with less waste heat are developed, extra heating of the passenger compartment is needed in the cold season. A reversible transcritical CO{sub 2} system with gliding temperature heat rejection can give high air delivery temperature which results in rapid heating of the passenger compartment and rapid defogging or defrosting of windows. When operated in cooling mode, the efficiency of transcritical CO{sub 2} systems is higher compared to common (HFC) air conditioning systems, at most dominant operating conditions. Several issues were identified for the design of compact interior heat exchangers for automotive reversible CO{sub 2} heat pumping systems. Among theses issues are: (1) Refrigerant flow distribution, (2) Heat exchanger fluid flow circuiting, (3) Air temperature uniformity downstream of the heat exchanger, (4) Minimization of temperature approach, (5) Windshield flash fogging due to retained water inside the heat exchanger, (6) Internal beat conduction in heating mode operation, and (7) Refrigerant side pressure drop In order to provide a basis for understanding these issues, the author developed a calculation model and set up a test facility and investigated different prototype heat exchangers experimentally.

  9. Radiation hygienic assessment of centralized heat and hot water supply of Bilibino village from Bilibin central nuclear heating- and power plant

    International Nuclear Information System (INIS)

    Eremin, V.A.; Marej, A.N.; Nechiporenko, N.I.; Rasskazov, A.P.; Sayapin, N.P.; Soldatov, G.E.; Shcherbinin, A.S.

    1983-01-01

    The experience in using an atomic power plant for heat and hot water supply of the village of Bilibino is outlined. Particular attention is given to the population radiation safety. It has been demonstrated that radiation safety of the system is ensured by maintaining fixed pressure levels in the heating media and by the hermetic state of heat exchanges. Water in the heat and hot water supply network meets the requirements for drinking water. Radioactive corrosion products were not detected in the test water. Gamma-radiation dose rate from the surface of heating devices and pipe-lines in the test premises did not exceed the natural background, that is, U.U1-0.025 mrad

  10. Multivariate optimization of a solar water heating system using the Simplex method

    CERN Document Server

    Michelson, E

    1982-01-01

    Two Simplex computer library packages for multivariate optimization have been tested on an hour-by-hour simulation of a solar water heating system. The two packages are: MINUITS written at CERN (Geneva) , and the E04CCF routine which is part of the UK Numerical Algorithms Group Library. Technical and economic optima have been derived for three of the following variables simultaneously: collector area, tilt, azimuth, and store volume. The two packages give the same results. The meteorological data used were one (composite) year for Hamburg (Germany) and 1964 for Kew (UK). The Hamburg data were also condensed to form a year consisting of 60 averaged days. The optima derived with the 60-day year were very close to those obtained with the 365-day year. The Simplex method, which is a direct search method, is known to be very robust. It is particularly suited to hour-by-hour simulations of solar heating systems since the function being minimized is not monotonically decreasing towards the minimum in sufficient sign...

  11. Some features of an economical central heating water supply

    International Nuclear Information System (INIS)

    Glaeser, G.

    1990-01-01

    This paper is concerned with the necessary savings of energy and fuel as well as reduction of pollutant emission in the field of central district heat supply. Results of studies on solving these problems are presented. To provide thermal power based on heating water essential features of the district heating system in the GDR are outlined and advantages, resources and limits of specific solutions quantified. Finally, selected systems are evaluated as to energy and cost expenses, and some conclusions are drawn for future concepts. (author)

  12. Design of water and heat recovery networks for the simultaneous minimisation of water and energy consumption

    International Nuclear Information System (INIS)

    Polley, Graham Thomas; Picon-Nunez, Martin; Lopez-Maciel, Jose de Jesus

    2010-01-01

    This paper describes procedures for the design of processes in which water and energy consumption form a large part of the operating cost. Good process design can be characterised by a number of properties, amongst the most important are: efficient use of raw materials, low capital cost and good operability. In terms of thermodynamic analysis these processes can be characterised as being either a 'pinch' problem or a 'threshold' problem. This paper concentrates on developing designs for problems of the threshold type. Most of the problems discussed by previous workers have been of this type. With these properties in mind this work looks at the design of integrated water and energy systems that exhibit the following features: 1. minimum water consumption, 2. minimum energy consumption, and 3. simple network structure. The approach applies for single contaminant. It is shown that the water conservation problem and the heat recovery problems can be de-coupled and the water conservation options should be established first. It is then shown that the number of heaters and heat recovery units required for the system, the quantity and type of hot utility needed for the plant and the complexity of the heat recovery network can all be determined without having to design any heat recovery network. This allows the engineer to select the better water conservation option before embarking on the design of the heat recovery network. For this type of problem the design of the heat recovery network itself is usually simple and straightforward.

  13. Development of space heating and domestic hot water systems with compact thermal energy storage. Compact thermal energy storage: Material development for System Integration

    NARCIS (Netherlands)

    Davidson, J.H.; Quinnell, J.; Burch, J.; Zondag, H.A.; Boer, R. de; Finck, C.J.; Cuypers, R.; Cabeza, L.F.; Heinz, A.; Jahnig, D.; Furbo, S.; Bertsch, F.

    2013-01-01

    Long-term, compact thermal energy storage (TES) is essential to the development of cost-effective solar and passive building-integrated space heating systems and may enhance the annual technical and economic performance of solar domestic hot water (DHW) systems. Systems should provide high energy

  14. Investigations on installation of the heat exchange system in geothermal wells; Chinetsu koseinai netsukokan system donyu ni kansuru chosa

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-03-01

    The heat exchange system in geothermal wells is a system that replaces the air source heat pump and uses underground beds or groundwater as a heat source to heat rooms by collecting underground heat in winter, and cool rooms in summer by operating a heat media circuit in reverse direction through the action of a reverse flow valve to discharge heat underground. This paper describes feasibility investigations on the system including its technical trend for introducing the system technology. Technological and economic discussions were given by classifying the intra-well heat exchange device in its installation direction (horizontal loop type and vertical installation type), underground heat exchange media (antifreeze solution/water cyclic system and direct expansion system), and underground heat transfer (heat conduction system and heat convection system). As a result of discussing each system, it was concluded that the following two systems are promising: A = vertical installation, antifreeze solution/water cyclic and heat conduction system, and B = vertical installation, antifreeze solution/water cyclic and heat convection system. Since the system B was found to have better efficiency and economy among both systems, it is necessary to verify an intra-well heat exchange system and operation methods that suit the system B effectively. 21 refs., 8 tabs.

  15. 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

  16. Heat transport analysis in a district heating and snow melting system in Sapporo and Ishikari, Hokkaido applying waste heat from GTHTR300

    International Nuclear Information System (INIS)

    Kasahara, Seiji; Kamiji, Yu; Terada, Atsuhiko; Yan Xing; Inagaki, Yoshiyuki; Murata, Tetsuya; Mori, Michitsugu

    2015-01-01

    A district heating and snow melting system utilizing waste heat from Gas Turbine High temperature Gas Reactor of 300 MW_e (GTHTR300), a heat-electricity cogeneration design of high temperature gas-cooled reactor, was analyzed. Application areas are set in Sapporo and Ishikari, the heavy snowfall cities in Northern Japan. The heat transport analyses are carried out by modeling the components in the system; pipelines of the secondary water loops between GTHTR300s and heat demand district and heat exchangers to transport the heat from the secondary water loops to the tertiary loops in the district. Double pipe for the secondary loops are advantageous for less heat loss and smaller excavation area. On the other hand, these pipes has disadvantage of more electricity consumption for pumping. Most of the heat demand in the month of maximum requirement can be supplied by 2 GTHTR300s and delivered by 9 secondary loops and around 5000 heat exchangers. Closer location of GTHTR300 site to the heat demand district is largely advantageous economically. Less decrease of the distance from 40 km to 20 km made the heat loss half and cost of the heat transfer system 22% smaller. (author)

  17. Solar water heating in the hotel industry

    Energy Technology Data Exchange (ETDEWEB)

    Urbanek, A

    1981-01-01

    There is an increasing number of hotels, pensions, guest-houses and boarding-houses whose owners attempt to lower their energy cost - especially for water heating in summer - by installing solar systems. The article presents some examples of buildings in West Germany.

  18. Energy consumption modeling of air source electric heat pump water heaters

    International Nuclear Information System (INIS)

    Bourke, Grant; Bansal, Pradeep

    2010-01-01

    Electric heat pump air source water heaters may provide an opportunity for significant improvements in residential water heater energy efficiency in countries with temperate climates. As the performance of these appliances can vary widely, it is important for consumers to be able to accurately assess product performance in their application to maximise energy savings and ensure uptake of this technology. For a given ambient temperature and humidity, the performance of an air source heat pump water heater is strongly correlated to the water temperature in or surrounding the condenser. It is therefore important that energy consumption models for these products duplicate the real-world water temperatures applied to the heat pump condenser. This paper examines a recently published joint Australian and New Zealand Standard, AS/NZS 4234: 2008; Heated water systems - Calculation of energy consumption. Using this standard a series TRNSYS models were run for several split type air source electric heat pump water heaters. An equivalent set of models was then run utilizing an alternative water use pattern. Unfavorable errors of up to 12% were shown to occur in modeling of heat pump water heater performance using the current standard compared to the alternative regime. The difference in performance of a model using varying water use regimes can be greater than the performance difference between models of product.

  19. Design of a Solar Water Heating System for Kuti Hall, University of ...

    African Journals Online (AJOL)

    Monthly average daily irradiance in plane of solar collector and Cold water temperature calculated from weather data collated to determine heating load. Mathematical model was developed based on heat transfer, thermal and optical and energy performance of collector. The absorber plate area, dimensions of solar ...

  20. Passive heat removal system with injector-condenser

    Energy Technology Data Exchange (ETDEWEB)

    Soplenkov, K I [All-Russian Inst. of Nuclear Power Plant Operation, Electrogorsk Research and Engineering Centre of Nuclear Power Safety (Russian Federation)

    1996-12-01

    The system described in this paper is a passive system for decay heat removal from WWERs. It operates off the secondary side of the steam generators (SG). Steam is taken from the SG to operate a passive injector pump which causes secondary fluid to be pumped through a heat exchanger. Variants pass either water or steam from the SG through the heat exchanger. There is a passive initiation scheme. The programme for experimental and theoretical validation of the system is described. (author). 8 figs.

  1. ITER SAFETY TASK NID-5D: Operational tritium loss and accident investigation for heat transport and water detritiation systems

    International Nuclear Information System (INIS)

    Kalyanam, K.M.; Fong, C.; Moledina, M.; Natalizio, A.

    1995-02-01

    The task objectives are to: a) determine major pathways for tritium loss during normal operation of the cooling systems and water detritiation system, b) estimate operational losses and environmental tritium releases from the heat transport and water detritiation systems of ITER, and c) prepare a preliminary Failure Modes and Effects Analysis (FMEA) for the ITER Water Detritiation System. The analysis will be used to estimate chronic environmental tritium releases (airborne and waterborne) for the ITER Cooling Systems and Water Detritiation System. The assessment will form the basis for demonstrating the acceptability of ITER for siting in the Early Safety and Environmental Characterization Study (ESECS), to be issued in early 1995. (author). 7 refs., 10 tabs., 11 figs

  2. Energetical and ecological assessment of solar- and heat pump technologies for hot water preparation and space heating in Austria

    International Nuclear Information System (INIS)

    Faninger, G.

    1991-11-01

    Solar and heat pump systems have been proved in many applications on the market. To achieve an efficient energy output it is necessary to consider the special conditions of these technologies. The energetical and ecological criteria of solar and heat pump systems for hot water preparation and space heating are analysed on the basis of experimental data. (author)

  3. Instrumentation for NBI SST-1 cooling water system

    International Nuclear Information System (INIS)

    Qureshi, Karishma; Patel, Paresh; Jana, M.R.

    2015-01-01

    Neutral Beam Injector (NBI) System is one of the heating systems for Steady state Superconducting Tokamak (SST-1). It is capable of generating a neutral hydrogen beam of power 0.5 MW at 30 kV. NBI system consists of following sub-systems: Ion source, Neutralizer, Deflection Magnet and Magnet Liner (ML), Ion Dump (ID), V-Target (VT), Pre Duct Scraper (PDS), Beam Transmission Duct (BTD) and Shine Through (ST). For better heat removal management purpose all the above sub-systems shall be equipped with Heat Transfer Elements (THE). During beam operation these sub-systems gets heated due to the received heat load which requires to be removed by efficient supplying water. The cooling water system along with the other systems (External Vacuum System, Gas Feed System, Cryogenics System, etc.) will be controlled by NBI Programmable Logic Control (PLC). In this paper instrumentation and its related design for cooling water system is discussed. The work involves flow control valves, transmitters (pressure, temperature and water flow), pH and conductivity meter signals and its interface with the NBI PLC. All the analog input, analog output, digital input and digital output signals from the cooling water system will be isolated and then fed to the NBI PLC. Graphical Users Interface (GUI) needed in the Wonderware SCADA for the cooling water system shall also be discussed. (author)

  4. Water from abandoned mines as a heat source: practical experiences of open- and closed-loop strategies, United Kingdom

    OpenAIRE

    Banks, D; Athresh, A; Al-Habaibeh, A; Burnside, N

    2017-01-01

    Pilot heat pump systems have been installed at two former collieries in Yorkshire/Derbyshire, England, to extract heat from mine water. The installations represent three fundamental configurations of heat exchanger. At Caphouse Colliery, mine water is pumped through a heat exchanger coupled to a heat pump and then discharged to waste (an open-loop heat exchange system). The system performs with high thermal efficiency, but the drawbacks are: (1) it can only be operated when mine water is bein...

  5. Heat transfer and fluid flow in nuclear systems

    CERN Document Server

    Fenech, Henri

    1982-01-01

    Heat Transfer and Fluid in Flow Nuclear Systems discusses topics that bridge the gap between the fundamental principles and the designed practices. The book is comprised of six chapters that cover analysis of the predicting thermal-hydraulics performance of large nuclear reactors and associated heat-exchangers or steam generators of various nuclear systems. Chapter 1 tackles the general considerations on thermal design and performance requirements of nuclear reactor cores. The second chapter deals with pressurized subcooled light water systems, and the third chapter covers boiling water reacto

  6. Long term performance of a solar floor and hot water heating house; Taiyonetsu yukadanbo kyuto jutaku no choki seino

    Energy Technology Data Exchange (ETDEWEB)

    Udagawa, M [Kogakuin University, Tokyo (Japan)

    1997-11-25

    Outlined herein are measured energy consumption followed for 12 years for a totally electrified solar house with a floor-heating and hot-water heating system. In the solar system, hot water generated by the solar collector is sent, via a surge tank, to a living room, dining room and study to heat their concrete floors, and recycled back to the collector after heating the heat-storage tank for hot water supply. The collector is of plate type, consisting of 6 units, each with a white glass sheet as the heat-collecting membrane for selectively absorbing heat. Its total heat-collecting area is 11.4m{sup 2}. Long-term performance of the solar system installed for floor and hot-water heating in a totally electrified solar house, is analyzed by the measured results collected for 12 years. The house consumes secondary energy of 11.7MWh/year on the average, which is approximately 20% lower that that required for a house of the equivalent size. The solar system has been operated smoothly, to supply 46 and 35% of the required heat for hot-water and floor heating. It is however estimated that annual heat loss reaches 34% in the hot-water heating system, including that in the electric hot-water generator, and prevention of heat loss is one of the major themes for the future system designs. 4 refs., 5 figs.

  7. Subscale Water Based Phase Change Material Heat Exchanger Development

    Science.gov (United States)

    Sheth, Rubik; Hansen, Scott

    2016-01-01

    Supplemental heat rejection devices are required in many spacecraft as the radiators are not sized to meet the full heat rejection demand. One means of obtaining additional heat rejection is through the use of phase change material heat exchangers (PCM HX's). PCM HX's utilize phase change to store energy in unfavorable thermal environments (melting) and reject the energy in favorable environments (freezing). Traditionally, wax has been used as a PCM on spacecraft. However, water is an attractive alternative because it is capable of storing about 40% more energy per unit mass due to its higher latent heat of fusion. The significant problem in using water as a PCM is its expansion while freezing, leading to structural integrity concerns when housed in an enclosed heat exchanger volume. Significant investigation and development has taken place over the past five years to understand and overcome the problems associated with water PCM HX's. This paper reports on the final efforts by Johnson Space Center's Thermal Systems Branch to develop a water based PCM HX. The test article developed and reported on is a subscale version of the full-scale water-based PCM HX's constructed by Mezzo Technologies. The subscale unit was designed by applying prior research on freeze front propagation and previous full-scale water PCM HX development. Design modifications to the subscale unit included use of urethane bladder, decreased aspect ratio, perforated protection sheet, and use of additional mid-plates. Testing of the subscale unit was successful and 150 cycles were completed without fail.

  8. Estimation of low-potential heat recuperation efficiency of smoke fumes in a condensation heat utilizer under various operation conditions of a boiler and a heating system

    Science.gov (United States)

    Ionkin, I. L.; Ragutkin, A. V.; Luning, B.; Zaichenko, M. N.

    2016-06-01

    For enhancement of the natural gas utilization efficiency in boilers, condensation heat utilizers of low-potential heat, which are constructed based on a contact heat exchanger, can be applied. A schematic of the contact heat exchanger with a humidifier for preheating and humidifying of air supplied in the boiler for combustion is given. Additional low-potential heat in this scheme is utilized for heating of the return delivery water supplied from a heating system. Preheating and humidifying of air supplied for combustion make it possible to use the condensation utilizer for heating of a heat-transfer agent to temperature exceeding the dewpoint temperature of water vapors contained in combustion products. The decision to mount the condensation heat utilizer on the boiler was taken based on the preliminary estimation of the additionally obtained heat. The operation efficiency of the condensation heat utilizer is determined by its structure and operation conditions of the boiler and the heating system. The software was developed for the thermal design of the condensation heat utilizer equipped by the humidifier. Computation investigations of its operation are carried out as a function of various operation parameters of the boiler and the heating system (temperature of the return delivery water and smoke fumes, air excess, air temperature at the inlet and outlet of the condensation heat utilizer, heating and humidifying of air in the humidifier, and portion of the circulating water). The heat recuperation efficiency is estimated for various operation conditions of the boiler and the condensation heat utilizer. Recommendations on the most effective application of the condensation heat utilizer are developed.

  9. Ground-water heat pumps: an examination of hydrogeologic, environmental, legal, and economic factors affecting their use

    Energy Technology Data Exchange (ETDEWEB)

    Armitage, D M; Bacon, D J; Massey-Norton, J T; Miller, J D

    1980-11-12

    Groundwater is attractive as a potential low-temperature energy source in residential space-conditioning applications. When used in conjuncton with a heat pump, ground water can serve as both a heat source (for heating) and a heat sink (for cooling). Major hydrogeologic aspects that affect system use include groundwater temperature and availability at shallow depths as these factors influence operational efficiency. Ground-water quality is considered as it affects the performance and life-expectancy of the water-side heat exchanger. Environmental impacts related to groundwater heat pump system use are most influenced by water use and disposal methods. In general, recharge to the subsurface (usually via injection wells) is recommended. Legal restrictions on system use are often stricter at the municipal and county levels than at state and Federal levels. Although Federal regulations currently exist, the agencies are not equipped to regulate individual, domestic installations. Computer smulations indicate that under a variety of climatologic conditions, groundwater heat pumps use less energy than conventional heating and cooling equipment. Life-cycle cost comparisons with conventional equipment depend on alternative system choices and well cost options included in the groundwater heat pump system.

  10. A heating system for piglets in farrowing house using waste heat from biogas engine

    Directory of Open Access Journals (Sweden)

    Payungsak Junyusen

    2008-12-01

    Full Text Available The aim of this study is to design and test a heating system for piglets in farrowing house by utilising the waste heat from a biogas engine as a heat source. The study was separated into three parts: the study on the biogas combined heat and power plant, the investigation on the properties of the heat panel, and the installation and testing of the heating system. From the experiment, the condition producing 60 kW of electrical power was a proper one, in which electrical efficiency and specific fuel consumption were 14% and 1.22 m3/kWh respectively. Generating both electricity and heat increased the overall efficiency to 37.7% and decreased the specific fuel consumption to 0.45 m3/kWh. The heat panel, which was made of a plastic material, had a thermal conductivity of 0.58 W/mC and the maximum compressive force and operating pressure of 8.1 kN and 0.35 bar respectively. The surface temperature of the panel was dependent on the inlet water temperature. When hot water of 44C was supplied into the farrowing house with room temperature of 26C, the average surface temperature was 33C. The developed heating system could provide heat for 4.3 farrowing houses. The payback period of this project was 2.5 years.

  11. Report on an investigation into heat pumps in China in fiscal 1995; 1995 nendo Chugoku ni okeru heat pump system ni kansuru chosa hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-03-01

    The paper surveyed the present status, the status of spread, and the technical development of the technology of heat pumps for residential and industrial uses in China. Main examples of installation of heat pumps are cited below: steam drive absorption type refrigerators in Beijing; sea water heat source turbo heat pumps in Qingdao; hot water drive absorption type refrigerators in Beijing; oil-fueled absorption type water cooling and heating appliances in Beijing; ice latent heat storage airconditioning systems using electrically-driven screw chiller in Beijing; temperature rising systems using electrically-driven heat pump of the solar energy utilization warm water swimming pool in Guangdong Province; cooling water supply using waste heat utilization absorption type refrigerator of the alcohol plant in Shandong Province; timber drying systems using electrically-driven heat pump, and marine product cultivation systems in Quangdong Province; distillation systems using steam turbine heat pump in Jiangxi Province. The demand for heat pumps is expected to be 20 million units under the 9th 5-year plan, and the development of equipment is thought to go toward promotion of energy conservation, low noise, multi-type or multi-functional air conditioning equipment, and computer use. 137 figs., 40 tabs.

  12. Chlorine attack in copper/cupronickel heat exchangers tubes in service water system

    International Nuclear Information System (INIS)

    Hortiguela, Ruben; Corchon, Fernando; Villesccas, Gilberto

    2012-09-01

    Santa Maria de Garona is a nuclear power plant design BWR type 3 with an open cooling circuit without cooling towers which outlets to the Ebro river. In November 2006, the presence of zebra mussels was found upstream of the plant intake. The recommended option for the service water system was to install a chlorination treatment using liquid sodium hypochlorite. This recommendation was based primarily on the need to have an effective mitigation system in place at Garona in the summer of 2007. The recommendation was to apply continuous or semi-continuous addition of chlorine to the service water system, preventing any primary attachment of zebra mussels to the service water piping. The chlorine injection system was designed to deliver approximately 0,3 to 0,5 ppm Total Residual Chlorine (TRC) to the service water on continuous basis. The chlorine injection pumps located at the start of the service water system are controlled by the output of a chlorine analyzer located at the end of the service water system just prior to discharge. After four years injecting NaClO, numerous cases of tube failures in heat exchangers made of copper and cupronickel alloys have been detected. The reactions involved are as follows: Corrosion Reactions in Cupronickel alloys Cl 2 + Ni → NiCl 2 E=1.610 V (Pitting Initiator), Cl 2 + Cu → CuCl 2 E=1.023 V. Corrosion Reactions in Copper tubes Cl 2 + Cu → CuCl 2 E=1.023 V. A close examination by optical microscope of the internal wall of the tubes has shown the typical crystals created from chorine corrosion such as: Cu (OH) 2 , CuCl 2 . (2H 2 O),NiCl 2 , [CuCl 3 ] -1 and [CuCl 4 ] -2 Conclusions: The degradation of the material is due to a combination of the following items: - Ageing of material after many years of operation; - Erosion due to poor quality of river water (silica particles, silts, sediments, etc); - Attack from chlorination to base material; The solutions that have been implemented are mainly: - Reduction of chlorine

  13. Heat transfer in vertical pipe flow at supercritical pressures of water

    International Nuclear Information System (INIS)

    Loewenberg, M.F.

    2007-05-01

    A new reactor concept with light water at supercritical conditions is investigated in the framework of the European project ''High Performance Light Water Reactor'' (HPLWR). Characteristics of this reactor are the system pressure and the coolant outlet temperature above the critical point of water. Water is regarded as a single phase fluid under these conditions with a high energy density. This high energy density should be utilized in a technical application. Therefore in comparison with up to date nuclear power plants some constructive savings are possible. For instance, steam dryers or steam separators can be avoided in contrast to boiling water reactors. A thermal efficiency of about 44% can be accomplished at a system pressure of 25MPa through a water heat-up from 280 C to 510 C. To ensure this heat-up within the core reliable predictions of the heat transfer are necessary. Water as the working fluid changes its fluid properties dramatically during the heat up in the core. As such; the density in the core varies by the factor of seven. The motivation to develop a look-up table for heat transfer predications in supercritical water is due to the significant temperature dependence of the fluid properties of water. A systematic consolidation of experimental data was performed. Together with further developments of the methods to derive a look-up table made it possible to develop a look-up table for heat transfer in supercritical water in vertical flows. A look-up table predicts the heat transfer for different boundary conditions (e.g. pressure or heat flux) with tabulated data. The tabulated wall temperatures for fully developed turbulent flows can be utilized for different geometries by applying hydraulic diameters. With the developed look-up table the difficulty of choosing one of the many published correlations can be avoided. In general, the correlations have problems with strong fluid property variations. Strong property variations combined with high heat

  14. Experimental and simulation study on the plate absorber for hybrid heat pump system

    Energy Technology Data Exchange (ETDEWEB)

    An, Seung Sun; Jung, Chung Woo; Kang, Yong Tae [Kyung Hee University, Yongin (Korea, Republic of); Kim, Min Sung; Park, Seong Ryong [KIER, Daejeon (Korea, Republic of); Kang, Chae Dong [Chonbuk National University, Jeonju (Korea, Republic of)

    2013-12-15

    This research conducts an experiment for a hybrid heat pump system, using ammonia-water as a working fluid, to obtain a hot water of about 80 .deg. C. The hybrid heat pump system is the combination of vapor compression cycle and absorption cycle to improve the performance of the heat pump system. The hybrid heat pump system uses a low temperature heat source of about 50 .deg. C from the industrial waste heat. The system consists of absorber, desorber, solution heat exchanger, oil heat exchanger, rectifier, compressor and a solution pump. Parametric analysis is carried out experimentally and numerically for the key parameters such as the capacity of the absorber, the internal pressure change. From the present experimental study, it is found that the maximum hot water temperature is obtained to be 79.33 .deg. C.

  15. Microbial growth in domestic hot water systems with special emphasis on connections to district heating networks

    Energy Technology Data Exchange (ETDEWEB)

    Frederiksen, S [Lund Institute of Technology, Dept. of Heat and Power Engineering, Lund (SE); Krongaard Kristensen, K [Regional Food and Hygiene Authority, Koebenhavns Amt Vest, Glostrup (DK)

    1991-01-01

    It is by now well-estalished that domestic hot water systems often harbour Legionella bacteria. Measurements into a number of Danish systems have revealed many other bacteria, among them the thermophilic species Thermus, which is predominantly found on heating coils, where local temperatures are higher. This bacterium not only hampers heat transfer due to fouling, but may also be pathogenic, due to release of endotoxins. Its presence may explain a wide spectrum of symptoms experienced by people after hot baths, such as rashes and itching. The paper summarizes these findings, and on this basis engineering and microbiological considerations are presented in an effort to find ways of future control strategies that go beyond Legionella prevention. Special attention is given to district heating connections, in which low supply and return temperatures are generally wanted in the primary circuit. (author) 16 refs.

  16. Study of an active wall solar heating system

    International Nuclear Information System (INIS)

    Kassem, Talal

    2006-01-01

    An active wall solar heating system was built and tested. In the same time a compatible computer program has been according to set the recommended dimensions for the solar collectors where (F-Chart) method used to set the ratio of monthly solar sharing average for the examined heating system. Some parameters, such as collectors' areas, its tilt angle and near earth reflecting were experimentally investigated, affecting the executed active solar heating system performance. The study explain the ability of using this system which is simple, Low coast and high performance in heating residential and public buildings and heating water with ratio of yearly solar sharing achieves the needed saving of using this system.(Author)

  17. 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...

  18. Development and validation of models for simulation of supercritical carbon dioxide Brayton cycles and application to self-propelling heat removal systems in boiling water reactors

    International Nuclear Information System (INIS)

    Venker, Jeanne

    2015-01-01

    The objective of the current work was to develop a model that is able to describe the transient behavior of supercritical carbon dioxide (sCO 2 ) Brayton cycles, to be applied to self-propelling residual heat removal systems in boiling water reactors. The developed model has been implemented into the thermohydraulic system code ATHLET. By means of this improved ATHLET version, novel residual heat removal systems, which are based on closed sCO 2 Brayton cycles, can be assessed as a retrofit measure for present light water reactors. Transient simulations are hereby of great importance. The heat removal system has to be modeled explicitly to account for the interaction between the system and the behavior of the plant during different accident conditions. As a first step, transport and thermodynamic fluid properties of supercritical carbon dioxide have been implemented in ATHLET to allow for the simulation of the new working fluid. Additionally, a heat transfer correlation has been selected to represent the specific heat transfer of supercritical carbon dioxide. For the calculation of pressure losses due to wall friction, an approach for turbulent single phase flow has been adopted that is already implemented in ATHLET. In a second step, a component model for radial compressors has been implemented in the system code. Furthermore, the available model for axial turbines has been adapted to simulate the transient behavior of radial turbines. All extensions have been validated against experimental data. In order to simulate the interaction between the self-propelling heat removal system and a generic boiling water reactor, the components of the sCO 2 Brayton cycle have been dimensioned with first principles. An available input deck of a generic BWR has then been extended by the residual heat removal system. The modeled application has shown that the extended version of ATHLET is suitable to simulate sCO 2 Brayton cycles and to evaluate the introduced heat removal system

  19. Energy and Exergy Performances of Air-Based vs. Water-Based Heating and Cooling Systems: A Case Study of a Single-Family House

    DEFF Research Database (Denmark)

    Kazanci, Ongun Berk; Shukuya, Masanori; Olesen, Bjarne W.

    2016-01-01

    Different indoor terminal units can be used to heat and cool indoor spaces. These terminal units mostly rely on convection and radiation heat transfer mechanisms but their relative ratios can vary significantly for air-based and water-based systems with implications on whole system performance, i...

  20. 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.

  1. Performance comparison of air-source heat pump water heater with different expansion devices

    International Nuclear Information System (INIS)

    Peng, Jing-Wei; Li, Hui; Zhang, Chun-Lu

    2016-01-01

    Highlights: • An air-source heat pump water heater model was developed and validated. • System performance with EEV, capillary tube or short tube orifice were compared. • Short tube orifice is more suitable for heat pump water heater than capillary tube. - Abstract: Air source heat pump water heater (ASHPWH) is designed to work under wide operating conditions. Therefore, both the system and components require higher reliability and stability than ordinary heat pump air-conditioning systems. In this paper, a quasi-steady-state system model of ASHPWH using electronic expansion valve (EEV), capillary tube or short tube orifice as expansion device is developed and validated by a prototype using R134a and scroll compressor, by which the system performance is evaluated and compared at varying water temperature and different ambient temperature. Flow characteristics of those three expansion devices in ASHPWH are comparatively analyzed. Results show that the EEV throttling system performs best. Compared with capillary tube, flow characteristics of short tube orifice are closer to that of EEV and therefore more suitable for ASHPWH. Reliability concern of liquid carryover to the compressor in the system using short tube orifice is investigated as well. Higher superheat or less system refrigerant charge could help mitigate the risk.

  2. Solar Space and Water Heating for Hospital --Charlottesville, Virginia

    Science.gov (United States)

    1982-01-01

    Solar heating system described in an 86-page report consists of 88 single-glazed selectively-coated baseplate collector modules, hot-water coils in air ducts, domestic-hot-water preheat tank, 3,000 Gallon (11,350-1) concrete urethane-insulated storage tank and other components.

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

    Science.gov (United States)

    Rijal, G K; Fujioka, R S

    2001-01-01

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

  4. Evaluation of Technical and Utility Programmatic Challenges With Residential Forced-Air Integrated Space/Water Heat Systems

    Energy Technology Data Exchange (ETDEWEB)

    Kingston, Tim [Partnership for Advanced Residential Retrofit, Des Plaines, IL (United States); Vadnal, Hillary [Partnership for Advanced Residential Retrofit, Des Plaines, IL (United States); Scott, Shawn [Partnership for Advanced Residential Retrofit, Des Plaines, IL (United States); Kalensky, Dave [Partnership for Advanced Residential Retrofit, Des Plaines, IL (United States)

    2016-12-01

    This multi-unit field demonstration of combined space and water heating (combi) systems was conducted to help document combi system installation and performance issues that needed to be addressed through research. The objective of the project was to put commercialized forced-air tankless combi units into the field through local contractors that were trained by manufacturers and GTI staff under the auspices of utility-implemented ETPs.

  5. Development and Validation of a Gas-Fired Residential Heat Pump Water Heater - Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Michael Garrabrant; Roger Stout; Paul Glanville; Janice Fitzgerald; Chris Keinath

    2013-01-21

    For gas-fired residential water heating, the U.S. and Canada is predominantly supplied by minimum efficiency storage water heaters with Energy Factors (EF) in the range of 0.59 to 0.62. Higher efficiency and higher cost ($700 - $2,000) options serve about 15% of the market, but still have EFs below 1.0, ranging from 0.65 to 0.95. To develop a new class of water heating products that exceeds the traditional limit of thermal efficiency, the project team designed and demonstrated a packaged water heater driven by a gas-fired ammonia-water absorption heat pump. This gas-fired heat pump water heater can achieve EFs of 1.3 or higher, at a consumer cost of $2,000 or less. Led by Stone Mountain Technologies Inc. (SMTI), with support from A.O. Smith, the Gas Technology Institute (GTI), and Georgia Tech, the cross-functional team completed research and development tasks including cycle modeling, breadboard evaluation of two cycles and two heat exchanger classes, heat pump/storage tank integration, compact solution pump development, combustion system specification, and evaluation of packaged prototype GHPWHs. The heat pump system extracts low grade heat from the ambient air and produces high grade heat suitable for heating water in a storage tank for domestic use. Product features that include conventional installation practices, standard footprint and reasonable economic payback, position the technology to gain significant market penetration, resulting in a large reduction of energy use and greenhouse gas emissions from domestic hot water production.

  6. Improvement in Performance of a Thermochemical Heat Storage System by Implementing an Internal Heat Recovery System

    NARCIS (Netherlands)

    Gaeini, M.; Saris, L.; Zondag, H.A.; Rindt, C.C.M.

    A lab-scale prototype of a thermochemical heat storage system, employing a water-zeolite 13X as the working pair, is designed and optimized for providing hot tap water. During the hydration process, humid air is introduced to the packed bed reactor filled with dehydrated zeolite 13X, and the

  7. Integration of space heating and hot water supply in low temperature district heating

    DEFF Research Database (Denmark)

    Elmegaard, Brian; Ommen, Torben Schmidt; Markussen, Michael

    2016-01-01

    District heating may supply many consumers efficiently, but the heat loss from the pipes to the ground is a challenge. The heat loss may be lowered by decreasing the network temperatures for which reason low temperature networks are proposed for future district heating. The heating demand...... of the consumers involves both domestic hot water and space heating. Space heating may be provided at low temperature in low energy buildings. Domestic hot water, however, needs sufficient temperatures to avoid growth of legionella. If the network temperature is below the demand temperature, supplementary heating...... is required by the consumer. We study conventional district heating at different temperatures and compare the energy and exergetic efficiency and annual heating cost to solutions that utilize electricity for supplementary heating of domestic hot water in low temperature district heating. This includes direct...

  8. Solar heating and cooling system with absorption chiller and low temperature latent heat storage: Energetic performance and operational experience

    Energy Technology Data Exchange (ETDEWEB)

    Helm, M.; Keil, C.; Hiebler, S.; Mehling, H.; Schweigler, C. [Bavarian Center for Applied Energy Research (ZAE Bayern) (Germany)

    2009-06-15

    Absorption cooling systems based on water/lithium bromide (LiBr) solution typically require an open wet cooling tower to transfer the reject heat to the ambient. Yet, water consumption, the need for water make-up and cleaning, formation of fog, and the risk of Legionella bacteria growth are hindering factors for the implementation of small solar cooling systems. The application of a latent heat storage supporting the heat rejection of the absorption chiller in conjunction with a dry cooling system allows eliminating the wet cooling tower. By that means heat rejection of the chiller is shifted to periods with lower ambient temperatures, i.e. night time or off-peak hours. The system concept and the hydraulic scheme together with an analysis of the energetic performance of the system are presented, followed by a report on the operation of a first pilot installation. (author)

  9. Analysis on the heating performance of a gas engine driven air to water heat pump based on a steady-state model

    International Nuclear Information System (INIS)

    Zhang, R.R.; Lu, X.S.; Li, S.Z.; Lin, W.S.; Gu, A.Z.

    2005-01-01

    In this study, the heating performance of a gas engine driven air to water heat pump was analyzed using a steady state model. The thermodynamic model of a natural gas engine is identified by the experimental data and the compressor model is created by several empirical equations. The heat exchanger models are developed by the theory of heat balance. The system model is validated by comparing the experimental and simulation data, which shows good agreement. To understand the heating characteristic in detail, the performance of the system is analyzed in a wide range of operating conditions, and especially the effect of engine waste heat on the heating performance is discussed. The results show that engine waste heat can provide about 1/3 of the total heating capacity in this gas engine driven air to water heat pump. The performance of the engine, heat pump and integral system are analyzed under variations of engine speed and ambient temperature. It shows that engine speed has remarkable effects on both the engine and heat pump, but ambient temperature has little influence on the engine's performance. The system and component performances in variable speed operating conditions is also discussed at the end of the paper

  10. Thermal energy recovery of air conditioning system--heat recovery system calculation and phase change materials development

    International Nuclear Information System (INIS)

    Gu Zhaolin; Liu Hongjuan; Li Yun

    2004-01-01

    Latent heat thermal energy storage systems can be used to recover the rejected heat from air conditioning systems, which can be used to generate low-temperature hot water. It decreases not only the consumption of primary energy for heating domestic hot water but also the calefaction to the surroundings due to the rejection of heat from air conditioning systems. A recovery system using phase change materials (PCMs) to store the rejected (sensible and condensation) heat from air conditioning system has been developed and studied, making up the shortage of other sensible heat storage system. Also, PCMs compliant for heat recovery of air conditioning system should be developed. Technical grade paraffin wax has been discussed in this paper in order to develop a paraffin wax based PCM for the recovery of rejected heat from air conditioning systems. The thermal properties of technical grade paraffin wax and the mixtures of paraffin wax with lauric acid and with liquid paraffin (paraffin oil) are investigated and discussed, including volume expansion during the phase change process, the freezing point and the heat of fusion

  11. A passive emergency heat sink for water cooled reactors with particular application to CANDU reg-sign reactors

    International Nuclear Information System (INIS)

    Spinks, N.J.

    1996-01-01

    Water in an overhead pool can serve as a general-purpose passive emergency heat sink for water-cooled reactors. It can be used for containment cooling, for emergency depressurization of the heat transport-system, or to receive any other emergency heat, such as that from the CANDU reg-sign moderator. The passive emergency water system provides in-containment depressurization of steam generators and no other provision is needed for supply of low-pressure emergency water to the steam generators. For containment cooling, the pool supplies water to the tube side of elevated tube banks inside containment. The elevation with respect to the reactor heat source maximizes heat transport, by natural convection, of hot containment gases. This effective heat transport combines with the large heat-transfer coefficients of tube banks, to reduce containment overpressure during accidents. Cooled air from the tube banks is directed past the break in the heat-transport system, to facilitate removal of hydrogen using passive catalytic recombiners

  12. Individual Heating systems vs. District Heating systems: What will consumers pay for convenience?

    International Nuclear Information System (INIS)

    Yoon, Taeyeon; Ma, Yongsun; Rhodes, Charles

    2015-01-01

    For Korea's two most popular apartment heating systems – Individual Heating (IH) and District Heating (DH), – user convenience rests heavily on location of the boiler, availability of hot water, administration of the system, and user control of indoor temperature. A double-bounded dichotomous choice method estimates consumer value for convenience, in a hypothetical market. Higher-income more-educated consumers in more expensive apartments prefer DH. Cost-conscious consumers, who use more electrical heating appliances and more actively adjust separate room temperatures, prefer IH. With willingness-to-pay (WTP) defined as the price ratio between IH and DH, 800 survey respondents indicate a WTP of 4.0% for DH over IH. IH users unfamiliar with DH expect little greater convenience (0.1% WTP), whereas the WTP for DH users runs to 7.9%, demonstrating consumer loyalty. Quantified estimates of consumer preference and convenience can inform design of a full-cost-plus pricing system with a price cap. Results here indirectly predict the effect of abolishing regulations that exclusively establish district heating zones. Strategies to foster the many external benefits of DH systems should stress not their lower cost, but convenience, comfort, and safety. Higher installation costs still hamper DH expansion, so policy-makers could set policies to lower cost barriers to entry. - Highlights: • District Heating (DH) and Individual Heating (IH) systems differ in user convenience. • Difference of convenience is evaluated by a double-bounded dichotomous choice method. • Consumers are willing to pay a 4.03–12.52% higher rate to use DH rather than IH. • Consumers with high living standards prefer DH to IH, and show high consumer loyalty. • Strategies to foster DH systems should stress DH convenience over its lower cost.

  13. A novel PV/T-air dual source heat pump water heater system: Dynamic simulation and performance characterization

    International Nuclear Information System (INIS)

    Cai, Jingyong; Ji, Jie; Wang, Yunyun; Zhou, Fan; Yu, Bendong

    2017-01-01

    Highlights: • The PV/T evaporator and air source evaporator connect in parallel and operate simultaneously. • A dynamic model is developed to simulate the behavior of the system. • The thermal and electrical characteristics of the PV/T evaporator are evaluated. • The contribution of the air source evaporator and PV/T evaporator has been discussed. - Abstract: To enable the heat pump water heater maintain efficient operation under diverse circumstances, a novel PV/T-air dual source heat pump water heater (PV/T-AHPWH) has been proposed in this study. In the PV/T-AHPWH system, a PV/T evaporator and an air source evaporator connect in parallel and operate simultaneously to recover energy from both solar energy and environment. A dynamic model is presented to simulate the behavior of the PV/T-AHPWH system. On this basis, the influences of solar irradiation, ambient temperature and packing factor have been discussed, and the contributions of air source evaporator and PV/T evaporator are evaluated. The results reveal that the system can obtain efficient operation with the average COP above 2.0 under the ambient temperature of 10 °C and solar irradiation of 100 W/m 2 . The PV/T evaporator can compensate for the performance degradation of the air source evaporator caused by the increasing condensing temperature. As the evaporating capacity in PV/T evaporator remains at relatively low level under low irradiation, the air source evaporator can play the main role of recovering heat. Comparing the performance of dual source heat pump system employing PV/T collector with that utilizing normal solar thermal collector, the system utilizing PV/T evaporator is more efficient in energy saving and performance improvement.

  14. FY 1986 Report on research and development of super heat pump energy accumulation system. System construction and operational study results (Systemization studies); 1986 nendo super heat pump energy shuseki system kenkyu kaihatsu seika hokokusho. System shisaku unten kenkyu (system ka kenkyu)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1987-03-01

    The studies on combinations of high-performance compression heat pump and chemical heat accumulation systems are conducted to construct the optimum systems for air conditioning/hot water supply for large-sized buildings and local districts, and also for industrial processes. For partial optimization of super heat pump (SPH) accumulation system, the SPH operational mode is changed to find the optimum conditions. As a result, it is found that system efficiency is the highest, and hence the power cost is the lowest, when the system is continuously operated night and day, followed by 2-night/1-day mode and night alone mode, in this order, for office building air conditioning, district air conditioning, and hot water supply. The effects of combination of SHP and chemical heat accumulation systems incorporated in an industrial process for heating are estimated. The results indicate that power load leveling effect is not 100% but 92%, even when the heat required for the daytime operation is totally supplied from the chemical accumulation system. The skeleton of the super heat pump accumulation system simulator is finalized, and the elementary system modules are developed, to allow simulation of general flows. (NEDO)

  15. Conceptual design study of geothermal district heating of a thirty-house subdivision in Elko, Nevada, using existing water-distribution systems, Phase III. Final technical report, October 1, 1979-September 30, 1980

    Energy Technology Data Exchange (ETDEWEB)

    Pitts, D.R.

    1980-09-30

    A conceptual design study for district heating of a 30-home subdivision located near the southeast extremity of the city of Elko, Nevada is presented. While a specific residential community was used in the study, the overall approach and methodologies are believed to be generally applicable for a large number of communities where low temperature geothermal fluid is available. The proposed district heating system utilizes moderate temperature, clean domestic water and existing community culinary water supply lines. The culinary water supply is heated by a moderate temperature geothermal source using a single heat exchanger at entry to the subdivision. The heated culinary water is then pumped to the houses in the community where energy is extracted by means of a water supplied heat pump. The use of heat pumps at the individual houses allows economic heating to result from supply of relatively cool water to the community, and this precludes the necessity of supplying objectionably hot water for normal household consumption use. Each heat pump unit is isolated from the consumptive water flow such that contamination of the water supply is avoided. The community water delivery system is modified to allow recirculation within the community, and very little rework of existing water lines is required. The entire system coefficient of performance (COP) for a typical year of heating is 3.36, exclusive of well pumping energy.

  16. Heating homes and water with the sun. Solar thermal solutions adapted to individual homes

    International Nuclear Information System (INIS)

    Bareau, Helene; Juniere, Olivier; Leplay, Camille

    2016-09-01

    This brochure, edited by ADEME, the French office for energy management and sustainable development, gives a basic outlook of the way to complete the installation of a solar space and hot water heating system in an individual home. After some recall of the key points to be considered before taking the decision to invest in a solar heating system (minimum surface, orientation, etc.) and the main administrative procedures to be respected (in France), this document presents the common individual solar water heating system (which is now reliable and robust), its various equipment and operating principles, the dimensioning of the system, gives recommendations on points such as the panel position and orientation, the risk of overheating and the way to avoid it, etc. It also presents combined solar heating solutions that simultaneously heat water and space, their operating principles and the way to complete their installation for a home. Informations on financing, selection of the equipment and the installer, and installation maintenance are also proposed

  17. 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.

  18. Design of stationary PEFC system configurations to meet heat and power demands

    Science.gov (United States)

    Wallmark, Cecilia; Alvfors, Per

    This paper presents heat and power efficiencies of a modeled PEFC system and the methods used to create the system configuration. The paper also includes an example of a simulated fuel cell system supplying a building in Sweden with heat and power. The main method used to create an applicable fuel cell system configuration is pinch technology. This technology is used to evaluate and design a heat exchanger network for a PEFC system working under stationary conditions, in order to find a solution with high heat utilization. The heat exchanger network in the system connecting the reformer, the burner, gas cleaning, hot-water storage and the PEFC stack will affect the heat transferred to the hot-water storage and thereby the heating of the building. The fuel, natural gas, is reformed to a hydrogen-rich gas within a slightly pressurized system. The fuel processor investigated is steam reforming, followed by high- and low-temperature shift reactors and preferential oxidation. The system is connected to the electrical grid for backup and peak demands and to a hot-water storage to meet the varying heat demand for the building. The procedure for designing the fuel cell system installation as co-generation system is described, and the system is simulated for a specific building in Sweden during 1 year. The results show that the fuel cell system in combination with a burner and hot-water storage could supply the building with the required heat without exceeding any of the given limitations. The designed co-generation system will provide the building with most of its power requirements and would further generate income by sale of electricity to the power grid.

  19. Optimal Control of Solar Heating System

    KAUST Repository

    Huang, Bin-Juine

    2017-02-21

    Forced-circulation solar heating system has been widely used in process and domestic heating applications. Additional pumping power is required to circulate the water through the collectors to absorb the solar energy. The present study intends to develop a maximum-power point tracking control (MPPT) to obtain the minimum pumping power consumption at an optimal heat collection. The net heat energy gain Qnet (= Qs − Wp/ηe) was found to be the cost function for MPPT. The step-up-step-down controller was used in the feedback design of MPPT. The field test results show that the pumping power is 89 W at Qs = 13.7 kW and IT = 892 W/m2. A very high electrical COP of the solar heating system (Qs/Wp = 153.8) is obtained.

  20. Theoretical study of heat pump system using CO2/dimethylether as refrigerant

    Directory of Open Access Journals (Sweden)

    Fan Xiao-Wei

    2013-01-01

    Full Text Available Nowadays, HCFC22 is widely used in heat pump systems in China, which should be phased out in the future. Thus, eco-friendly mixture CO2/dimethylether is proposed to replace HCFC22. Compared with pure CO2 and pure dimethylether, the mixture can reduce the heat rejection pressure, and suppress the flammability and explosivity of pure dimethylether. According to the Chinese National Standards on heat pump water heater and space heating system, performances of the subcritical heat pump system are discussed and compared with those of the HCFC22 system. It can be concluded that CO2 /dimethylether mixture works efficiently as a refrigerant for heat pumps with a large heat-sink temperature rise. When mass fraction of dimethylether is increased, the heat rejection pressure is reduced. Under the nominal working condition, there is an optimal mixture mass fraction of 28/72 of CO2/dimethylether for water heater application under conventional condensation pressure, 3/97 for space heating application. For water heater application, both the heating coefficient of performance and volumetric heating capacity increase by 17.90% and 2.74%, respectively, compared with those of HCFC22 systems. For space heating application, the heating coefficient of performance increases by 8.44% while volumetric heating capacity decreases by 34.76%, compared with those of HCFC22 systems. As the superheat degree increases, both the heating coefficient of performance and volumetric heating capacity tend to decrease.

  1. Performance evaluation of solar heating system with thermal core type soil heat storage. Part 5. Performance prediction and evaluation of the system considered of the weather condition; Taiyonetsu riyo netsu kakushiki dojo chikunetsu system no seino hyoka. 5. Kisho joken wo koryoshita system no seino yosoku to hyoka

    Energy Technology Data Exchange (ETDEWEB)

    Yoshida, N [Nishimatsu Construction Co. Ltd., Tokyo (Japan); Nakajima, Y [Kogakuin University, Tokyo (Japan)

    1997-11-25

    The paper studied a solar heating system with thermal core type soil heat storage (combining a thermal core composing of a water tank and an underground pebble tank and the soil around the heat storage tank and also using solar energy). Solar energy is stored by temperature level in the high temperature water tank, the low temperature pebble heat storage tank and the soil around the heat storage tank. Heat is recovered according to temperature as direct ventilation space heating (utilization of pebble tank air), floor heating (utilization of hot water of the heat storage water tank) and heat pump heat source (utilization of pebble tank air). A study was made of performance and regional effectiveness of the system under different weather conditions. A study was also made of effects of the water tank for short term heat storage by changing the water volume. Using the same structure, etc. for the system, the system was evaluated using weather data of Sapporo, Tokyo and Kagoshima. In terms of efficiency of the system, the system structure was found to be most suitable for weather conditions in Tokyo. However, the air heat source heat pump which cannot be usually used in the cold area has come to be used. Such effect except efficiency is also considered, and the amount of performance to be targeted in each region changes. 2 refs., 14 figs., 1 tab.

  2. Dynamic behavior of district heating systems

    International Nuclear Information System (INIS)

    Kunz, J.

    1994-01-01

    The goal of this study is to develop a simulation model of a hot water system taking into account the time dependent phenomena which are important for the operational management of such a system. A state of the art literature review has shown that there is no such model considering all parts from the generation of the heat at the plant to its consumption in the connected buildings so far. First, an exhaustive list of all dynamic phenomena occurring in district heating systems has been drawn and analyzed. Considering this list, this thesis proposes that a model which satisfies the criteria listed above can be developed by superposing four sub-models which are a dynamic model of the heat generation plant, a steady state model of the hydraulic calculation of the distribution network, a dynamic model of the thermal behavior of the network and a dynamic model of the heat consumers. The development of the four sub-models starts from the fundamental conservation equations for fluid systems, i.e. the conservation of mass, momentum and energy. The transformations of those general equations into simple calculation formulas show and justify the hypotheses made in the modeling process. The heat generation plant model itself is a set of sub-models: the models for steam boilers, hot water boilers and heat accumulators which take account of the dynamic evolution of the water temperature by a simple form of the energy conservation equation, as well as the steady state models for circulation pumps and pressurizers. Since the velocities in the network pipes are small, a consideration of steady states is adopted. A network model allowing to calculate the hydraulic variables in every point is adopted from the graph theory. The pressures and flow rates in the network are calculated at discrete time steps and they are considered to be constant for the duration between the time steps. (author) figs., tabs., refs

  3. Fiscal 1974 Sunshine Project result report. Research on solar cooling/heating and hot water supply system; 1974 nendo taiyonetsu reidanbo kyuto system no kenkyu seika hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1975-03-01

    This report describes the fiscal 1974 research result on solar cooling/heating and hot water supply system. This 3- year project from fiscal 1974 to 1976 aims to predict the share of solar energy in future cooling/heating and hot water supply energy demand, and develop simulation technology. The project surveys and analyzes current domestic and overseas development states, and studies various systems to obtain characteristics of every system, pursuit an optimum implementation, and establish a diffusion plan. Future energy consumptions and prices are predicted in relation to energy saving, and the utilization impact of solar energy is analyzed. Study is also made on diffusion plan, profitability and performance evaluation method. Among these schedules, in fiscal 1974 based on the survey and analysis on previous domestic and overseas development states, features and problems were arranged every system and application. The basic study on system simulation, and rough feasibility study on solar heat systems by conventional technique were carried out. The basic data on performance evaluation standards were also prepared. (NEDO)

  4. Integrating wind power using intelligent electric water heating

    International Nuclear Information System (INIS)

    Fitzgerald, Niall; Foley, Aoife M.; McKeogh, Eamon

    2012-01-01

    Dwindling fossil fuel resources and pressures to reduce greenhouse gas emissions will result in a more diverse range of generation portfolios for future electricity systems. Irrespective of the portfolio mix the overarching requirement for all electricity suppliers and system operators is to instantaneously meet demand, to operate to standards and reduce greenhouse gas emissions. Therefore all electricity market participants will ultimately need to use a variety of tools to balance the power system. Thus the role of demand side management with energy storage will be paramount to integrate future diverse generation portfolios. Electric water heating has been studied previously, particularly at the domestic level to provide load control, peak shave and to benefit end-users financially with lower bills, particularly in vertically integrated monopolies. In this paper a number of continuous direct load control demand response based electric water heating algorithms are modelled to test the effectiveness of wholesale electricity market signals to study the system benefits. The results are compared and contrasted to determine which control algorithm showed the best potential for energy savings, system marginal price savings and wind integration.

  5. The comparison of solar water heating system operation parameters calculated using traditional method and dynamic simulations

    Directory of Open Access Journals (Sweden)

    Sornek Krzysztof

    2016-01-01

    Full Text Available The proper design of renewable energy based systems is really important to provide their efficient and safe operation. The aim of this paper is to compare the results obtained during traditional static calculations, with the results of dynamic simulations. For this reason, simulations of solar water heating (SWH system, designed for a typical residential building, were conducted in the TRNSYS (Transient System Simulation Tool. Carried out calculations allowed to determine the heat generation in the discussed system as well as to estimate the efficiency of considered installation. Obtained results were compared with the results from other available tool based on the static calculations. It may be concluded, that using dynamic simulations at the designing stage of renewable energy based systems may help to avoid many exploitation problems (including low efficiency, overheating etc. and allows to provide safe exploitation of such installations.

  6. Demand side management for commercial buildings using an in line heat pump water heating methodology

    International Nuclear Information System (INIS)

    Rankin, Riaan; Rousseau, Pieter G.; Eldik, Martin van

    2004-01-01

    Most of the sanitary hot water used in South African buildings is heated by means of direct electrical resistance heaters. This is one of the major contributors to the undesirably high morning and afternoon peaks imposed on the national electricity supply grid. For this reason, water heating continues to be of concern to the electricity supplier, ESCOM. Previous studies, conducted by the Potchefstroom University for Christian Higher Education in South Africa, indicated that extensive application of the so called inline heat pump water heating methodology in commercial buildings could result in significant demand side management savings to ESKOM. Furthermore, impressive paybacks can be obtained by building owners who choose to implement the design methodology on existing or new systems. Currently, a few examples exist where the design methodology has been successfully implemented. These installations are monitored with a fully web centric monitoring system that allows 24 h access to data from each installation. Based on these preliminary results, a total peak demand reduction of 108 MW can be achieved, which represents 18% of the peak load reduction target set by ESKOM until the year 2015. This represents an avoided cost of approximately MR324 (ZAR) [Int J Energy Res 25(4) (1999) 2000]. Results based on actual data from the monitored installations shows a significant peak demand reduction for each installation. In one installation, a hotel with an occupancy of 220 people, the peak demand contribution of the hot water installation was reduced by 86%, realizing a 36% reduction in peak demand for the whole building. The savings incurred by the building owner also included significant energy consumption savings due to the superior energy efficiency of the heat pump water heater. The combined savings result in a conservatively calculated straight payback period of 12.5 months, with an internal rate of return of 98%. The actual cost of water heating is studied by

  7. Solar heating systems for houses. A design handbook for solar combisystems

    International Nuclear Information System (INIS)

    Weiss, W.

    2003-11-01

    A handbook giving guidance on systems for providing combined solar space heating and solar water heating for houses has been produced by an international team. The guidance focuses on selection of the optimum combi-system for groups of single-family houses and multi-family houses. Standard classification and evaluation procedures are described. The book should be a valuable tool for building engineers, architects, solar manufacturers and installers of solar solar energy systems, and anyone interested in optimizing combined water and space heating solar systems

  8. Local heat transfer where heated rods touch in axially flowing water

    International Nuclear Information System (INIS)

    Kast, S.J.

    1983-05-01

    An anlaytic model is developed to predict the azimuthal width of a stablesteam blanket region near the line of contact between two heated rods cooled by axially flowing water at high pressure. The model is intended to aid analysis of reduced surface heat transfer capability for the abnormal configuration of nuclear fuel rods bowed into contact in the core of a pressurized water nuclear reactor. The analytic model predicts the azimuthal width of the steam blanket zone having reduced surface heat transfer as a function of rod average heat flux, subchannel coolant conditions and rod dimensions. The analytic model is developed from a heat balance between the heat generated in the wall of a heated empty tube and the heat transported away by transverse mixing and axial convection in the coolant subchannel. The model is developed for seveal geometries including heated rods in line contact, a heated rod touching a short insulating plane and a heated rod touching the inside of a metal guide tube

  9. Experimental study on a hybrid photovoltaic/heat pump system

    International Nuclear Information System (INIS)

    Chen Hongbing; Riffat, Saffa B.; Fu Yu

    2011-01-01

    Several studies have found that the decrease of photovoltaic (PV) cell temperature would increase the solar-to-electricity conversion efficiency. Different working fluids such as air and water have been used for the cooling of PV modules, but the improvement in energy performance has been found to be small. In this paper, R134a refrigerant was employed to cool the PV modules. With its low evaporating temperature, it was expected to achieve better cooling effect and electrical performance of the PV modules than using air and water working fluids. An experimental rig of a hybrid micro PV panel-based heat pump system was constructed for the performance testing in a laboratory at University of Nottingham. A small PV panel was made of 6 glass vacuum tube - PV module - aluminium sheet - cooper tube (GPAC) sandwiches connected in series, acting as the evaporator. This was coupled with a small heat pump system. The glass vacuum tubes reduced the heat loss from the PV panel to the ambient, resulting in the improvement of thermal performance. Three testing modes were proposed to investigate the effect of solar radiation, condenser water flow rate and condenser water supply temperature on energy performance. The testing results showed that an averaged COP reached 3.8, 4.3 and 4.0 under the three testing modes with variable radiation, condenser water supply water temperature and water flow rate, respectively, but this could be much higher for a large capacity heat pump system using large PV panels on building roofs. The COP increased with the increasing solar radiation, but decreased with the increasing condenser water supply temperature and water flow rate. The electrical efficiency of PV panel was improved by up to 1.9% based on a reference PV efficiency of 3.9%, compared with that without cooling. The condenser water supply temperature and water flow rate had little effect on the electrical performance. - Highlights: → R134a refrigerant was used for cooling of PV modules

  10. Energy Efficiency of Low-Temperature Deaeration of Makeup Water for a District Heating System

    Energy Technology Data Exchange (ETDEWEB)

    Sharapov, V. I., E-mail: vlad-sharapov2008@yandex.ru; Kudryavtseva, E. V. [Ulyanovsk State Technical University (Russian Federation)

    2016-07-15

    It is shown that the temperature of makeup water in district heating systems has a strong effect on the energy efficiency of turbines of thermal power plants. A low-temperature deaeration process that considerably improves the energy efficiency of thermal power plants is developed. The desorbing agent is the gas supplied to the burners of the boiler. The energy efficiency of the process for a typical unit of thermal power plant is assessed.

  11. MULTIFUNCTIONAL SOLAR SYSTEMS FOR HEATING AND COOLING

    Directory of Open Access Journals (Sweden)

    Doroshenko A.V.

    2010-12-01

    Full Text Available The basic circuits of multifunctional solar systems of air drainage, heating (hot water supply and heating, cooling and air conditioning are developed on the basis of open absorption cycle with a direct absorbent regeneration. Basic decisions for new generation of gas-liquid solar collectors are developed. Heat-mass-transfer apparatus included in evaporative cooling system, are based on film interaction of flows of gas and liquid and in them, for the creation of nozzle, multi-channel structures from polymeric materials and porous ceramics are used. Preliminary analysis of multifunctional systems possibilities is implemented.

  12. OPTIMUM HEAT STORAGE DESIGN FOR SDHW SYSTEMS

    DEFF Research Database (Denmark)

    Shah, Louise Jivan; Furbo, Simon

    1997-01-01

    Two simulation models have been used to analyse the heat storage design’s influence on the thermal performance of solar domestic hot water (SDHW) systems. One model is especially designed for traditional SDHW systems based on a heat storage design where the solar heat exchanger is a built-in spiral....... The other model is especially designed for low flow SDHW systems based on a mantle tank.The tank design’s influence on the thermal performance of the SDHW systems has been investigated in a way where only one tank parameter has been changed at a time in the calculations. In this way a direct analysis...

  13. Four decades of working experience of Cirus primary cooling water heat exchangers

    International Nuclear Information System (INIS)

    Dubey, P.K.; Ullas, O.P.; Rao, D.V.H.; Zope, A.K.; Kharpate, A.V.

    2006-01-01

    CIRUS is a 40 MW (Th.) research reactor, commissioned in the year 1960. The reactor has natural uranium fuel rods, heavy water as moderator, demineralised water (DM water) as primary coolant, and seawater as secondary coolant. There are six Heat Exchangers in the primary cooling water (PCW) system. Five of them are required for the normal operation of the reactor and one is kept stand by. DM water flows on the shell side of the heat exchanger in two passes. Seawater is used as coolant on the tube side of the heat exchangers in four passes. Cirus has been in operation for around 41 years excluding refurbishment period. During these four decades of reactor operation, PCW heat exchangers have experienced many failures and undergone many modifications in the circuit for ensuring better performance. This paper tries to capture the essence of working experiences with PCW heat exchangers, various problems faced, remedial measures taken during those four decades of reactor operation. (author)

  14. Possibility of heat recovery from gray water in residential building

    Directory of Open Access Journals (Sweden)

    Mazur Aleksandra

    2017-12-01

    Full Text Available Recovery of waste heat from gray water can be an interesting alternative to other energy saving systems in a building, including alternative energy sources. Mainly, due to a number of advantages including independence from weather conditions, small investment outlay, lack of user support, or a slight interference with the installation system. The purpose of this article is to present the financial effectiveness of installations which provide hot, usable water to a detached house, using a Drain Water Heat Recovery (DWHR system depending on the number of system users and the various combinations of bathing time in the shower, which has an influence on the daily warm water demand in each of the considered options. The economic analysis of the adopted installation variants is based on the Life Cycle Cost (LCC method, which is characterized by the fact that it also includes the operating costs in addition to the capital expenditure during the entire analysis period. For each case, the necessary devices were selected and the cost of their installation was estimated.

  15. Possibility of heat recovery from gray water in residential building

    Science.gov (United States)

    Mazur, Aleksandra; Słyś, Daniel

    2017-12-01

    Recovery of waste heat from gray water can be an interesting alternative to other energy saving systems in a building, including alternative energy sources. Mainly, due to a number of advantages including independence from weather conditions, small investment outlay, lack of user support, or a slight interference with the installation system. The purpose of this article is to present the financial effectiveness of installations which provide hot, usable water to a detached house, using a Drain Water Heat Recovery (DWHR) system depending on the number of system users and the various combinations of bathing time in the shower, which has an influence on the daily warm water demand in each of the considered options. The economic analysis of the adopted installation variants is based on the Life Cycle Cost (LCC) method, which is characterized by the fact that it also includes the operating costs in addition to the capital expenditure during the entire analysis period. For each case, the necessary devices were selected and the cost of their installation was estimated.

  16. Development and validation of models for simulation of supercritical carbon dioxide Brayton cycles and application to self-propelling heat removal systems in boiling water reactors

    Energy Technology Data Exchange (ETDEWEB)

    Venker, Jeanne

    2015-03-31

    The objective of the current work was to develop a model that is able to describe the transient behavior of supercritical carbon dioxide (sCO{sub 2}) Brayton cycles, to be applied to self-propelling residual heat removal systems in boiling water reactors. The developed model has been implemented into the thermohydraulic system code ATHLET. By means of this improved ATHLET version, novel residual heat removal systems, which are based on closed sCO{sub 2} Brayton cycles, can be assessed as a retrofit measure for present light water reactors. Transient simulations are hereby of great importance. The heat removal system has to be modeled explicitly to account for the interaction between the system and the behavior of the plant during different accident conditions. As a first step, transport and thermodynamic fluid properties of supercritical carbon dioxide have been implemented in ATHLET to allow for the simulation of the new working fluid. Additionally, a heat transfer correlation has been selected to represent the specific heat transfer of supercritical carbon dioxide. For the calculation of pressure losses due to wall friction, an approach for turbulent single phase flow has been adopted that is already implemented in ATHLET. In a second step, a component model for radial compressors has been implemented in the system code. Furthermore, the available model for axial turbines has been adapted to simulate the transient behavior of radial turbines. All extensions have been validated against experimental data. In order to simulate the interaction between the self-propelling heat removal system and a generic boiling water reactor, the components of the sCO{sub 2} Brayton cycle have been dimensioned with first principles. An available input deck of a generic BWR has then been extended by the residual heat removal system. The modeled application has shown that the extended version of ATHLET is suitable to simulate sCO{sub 2} Brayton cycles and to evaluate the introduced

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

    Directory of Open Access Journals (Sweden)

    Nannan Dai

    2017-02-01

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

  18. Simulation of a heat pump system for total heat recovery from flue gas

    International Nuclear Information System (INIS)

    Wei, Maolin; Yuan, Weixing; Song, Zhijia; Fu, Lin; Zhang, Shigang

    2015-01-01

    This paper introduces an approach of using an open-cycle absorption heat pump (OAHP) for recovering waste heat from the flue gas of a gas boiler with a system model. And equivalent energy efficiency is used to evaluate two other heat recovery systems that integrate an electric compression heat pump (EHP) or an absorption heat pump (AHP) with a boiler. The key factors influencing the systems are evaluated. The OAHP system efficiency is improved by 11% compared to the base case. And the OAHP system is more efficient than the AHP or the EHP systems, especially when the solution mass flow rate is only a little less than the cold water mass flow rate. The energy efficiency comparison is supplemented with a simplified economic analysis. The results indicate that the OAHP system is the best choice for the current prices of electricity and natural gas in Beijing. - Highlights: • An OAHP system is analyzed to improve heat recovery from natural gas flue gas. • OAHP system models are presented and analyzed. • The key factors influencing the OAHP systems are analyzed. • The OAHP system is most efficient for most cases compared with other systems. • The OAHP system is more economic than other systems

  19. Supercritical water gasification with decoupled pressure and heat transfer modules

    KAUST Repository

    Dibble, Robert

    2017-09-14

    The present invention discloses a system and method for supercritical water gasification (SCWG) of biomass materials wherein the system includes a SCWG reactor and a plurality of heat exchangers located within a shared pressurized vessel, which decouples the function of containing high pressure from the high temperature function. The present invention allows the heat transfer function to be conducted independently from the pressure transfer function such that the system equipment can be designed and fabricated in manner that would support commercial scaled-up SCWG operations. By using heat exchangers coupled to the reactor in a series configuration, significant efficiencies are achieved by the present invention SCWG system over prior known SCWG systems.

  20. Vapor Compression and Thermoelectric Heat Pump Heat Exchangers for a Condensate Distillation System: Design and Experiment

    Science.gov (United States)

    Erickson, Lisa R.; Ungar, Eugene K.

    2013-01-01

    Maximizing the reuse of wastewater while minimizing the use of consumables is critical in long duration space exploration. One of the more promising methods of reclaiming urine is the distillation/condensation process used in the cascade distillation system (CDS). This system accepts a mixture of urine and toxic stabilizing agents, heats it to vaporize the water and condenses and cools the resulting water vapor. The CDS wastewater flow requires heating and its condensate flow requires cooling. Performing the heating and cooling processes separately requires two separate units, each of which would require large amounts of electrical power. By heating the wastewater and cooling the condensate in a single heat pump unit, mass, volume, and power efficiencies can be obtained. The present work describes and compares two competing heat pump methodologies that meet the needs of the CDS: 1) a series of mini compressor vapor compression cycles and 2) a thermoelectric heat exchanger. In the paper, the system level requirements are outlined, the designs of the two heat pumps are described in detail, and the results of heat pump performance tests are provided. A summary is provided of the heat pump mass, volume and power trades and a selection recommendation is made.

  1. Energy Savings for Solar Heating Systems

    DEFF Research Database (Denmark)

    Thür, Alexander; Furbo, Simon; Shah, Louise Jivan

    2006-01-01

    showed a good degree of similarity. With the boiler model, various simulations of solar domestic hot water heating systems were done for different hot water demands and collector sizes. The result shows that the potential of fuel reduction can be much higher than the solar gain of the solar thermal...... system. For some conditions the fuel reduction can be up to the double of the solar gain due to a strong increase of the system efficiency. As the monitored boilers were not older than 3 years, it can be assumed that the saving potential with older boilers could be even higher than calculated......In this paper the realistic behaviour and efficiency of heating systems were analysed, based on long term monitoring projects. Based on the measurements a boiler model used to calculate the boiler efficiency on a monthly basis was evaluated. Comparisons of measured and calculated fuel consumptions...

  2. Combined Active and Passive Solar Space Heating and Solar Hot Water Systems for an Elementary School in Boise, Idaho.

    Science.gov (United States)

    Smull, Neil A.; Armstrong, Gerald L.

    1979-01-01

    Amity Elementary School in Boise, Idaho, features a solar space heating and domestic hot water system along with an earth covering to accommodate the passive aspects of energy conservation. (Author/MLF)

  3. Passive safety systems for decay heat removal of MRX

    Energy Technology Data Exchange (ETDEWEB)

    Ochiai, M; Iida, H; Hoshi, T [Japan Atomic Energy Research Inst., Ibaraki (Japan). Nuclear Ship System Lab.

    1996-12-01

    The MRX (marine Reactor X) is an advanced marine reactor, its design has been studied in Japan Atomic Energy Research Institute. It is characterized by four features, integral type PWR, in-vessel type control rod drive mechanisms, water-filled containment vessel and passive decay heat removal system. A water-filled containment vessel is of great advantage since it ensures compactness of a reactor plant by realizing compact radiation shielding. The containment vessel also yields passive safety of MRX in the event of a LOCA by passively maintaining core flooding without any emergency water injection. Natural circulation of water in the vessels (reactor and containment vessels) is one of key factors of passive decay heat removal systems of MRX, since decay heat is transferred from fuel rods to atmosphere by natural circulation of the primary water, water in the containment vessel and thermal medium in heat pipe system for the containment vessel water cooling in case of long terms cooling after a LOCA as well as after reactor scram. Thus, the ideal of water-filled containment vessel is considered to be very profitable and significant in safety and economical point of view. This idea is, however, not so familiar for a conventional nuclear system, so experimental and analytical efforts are carried out for evaluation of hydrothermal behaviours in the reactor pressure vessel and in the containment vessel in the event of a LOCA. The results show the effectiveness of the new design concept. Additional work will also be conducted to investigate the practical maintenance of instruments in the containment vessel. (author). 4 refs, 9 figs, 2 tabs.

  4. Solar water heating systems feasibility for domestic requests in Tunisia: Thermal potential and economic analysis

    International Nuclear Information System (INIS)

    Hazami, Majdi; Naili, Nabiha; Attar, Issam; Farhat, Abdelhamid

    2013-01-01

    Highlights: • The present work studies the potential of using Domestic Solar Water Heating systems. • The payback period is between 8 and 7.5 years. • The annual savings in electrical energy is between 1316 and 1459 kW h/year. • The savings by using the solar systems is about 3969–4400.34 $. • The annual GHG emission per house is reduced by 27,800 tCO 2 . - Abstract: The main goal of the present work is to study the energetic and the economic potential of the deployment of Domestic Solar Water Heating systems (DSWHs) instead of using electric/gas/town gas water heaters. A case study related to Tunisian scenario was performed according to a typical Tunisian households composed of 4–5 persons. In this scenario we evaluated the performance and the life cycle perspective of the two most popular DSWHs over the recent years (i.e. DSWH with flat-plate solar collector, FPC, and DSWHs with evacuated-tube solar collector, ETC). The dynamic behavior of DSWHs according to Tunisian data weather was achieved by means of TRNSYS simulation. The Results showed that the FPC and ETC provide about 8118 and 12032 kW h/year of thermal energy. The economic potential of DSWHs in saving electricity and reducing carbon dioxide emissions was also investigated. Results showed that the annual savings in electrical energy relatively to the FPC and ETC are about 1316 and 1459 kW h/year, with a payback period of around 8 and 10 years, respectively. Based on gas/town gas water heater, the FPC and ETC save about 306 m 3 and 410 m 3 of gas/town gas with a payback period about 6 and 7.5 years, respectively. We found that the life cycle savings by installing the solar system instead of buying electricity to satisfy hot water needs are about $3969 (FPC) and $4400 (ETC). We establish also that the use of the DSWHs instead of installing gas/town gas water heaters save about $1518 (FPC) and $2035 (ETC). From an environmental point of view the annual GHG emission per house is reduced by 27800

  5. Heating Water with Solar Energy Costs Less at the Phoenix Federal Correctional Institution

    Energy Technology Data Exchange (ETDEWEB)

    2004-09-01

    A large solar thermal system installed at the Phoenix Federal Correctional Institution (FCI) in 1998 heats water for the prison and costs less than buying electricity to heat that water. This renewable energy system provides 70% of the facility's annual hot water needs. The Federal Bureau of Prisons did not incur the up-front cost of this system because it was financed through an Energy Savings Performance Contract (ESPC). The ESPC payments are 10% less than the energy savings so that the prison saves an average of$6,700 per year, providing an immediate payback. The solar hot water system produces up to 50,000 gallons of hot water daily, enough to meet the needs of 1,250 inmates and staff who use the kitchen, shower, and laundry facilities.

  6. Modelling and multi-scenario analysis for electric heat tracing system combined with low temperature district heating for domestic hot water supply

    DEFF Research Database (Denmark)

    Yang, Xiaochen; Li, Hongwei; Svendsen, Svend

    2016-01-01

    Low temperature district heating (LTDH) is a cost-efficient way of supplying space heating and domestic hot water (DHW) for buildings in urban areas. However, there is concern that the potential hygiene problems (Legionella) might occur if LTDH is implemented, especially for large buildings...... performance on heat loss saving, and it also gave benefits to district heating network by sharing part of the heating load....

  7. The Economics of Connecting of Small Buildings to Geothermal District Heating Systems

    Energy Technology Data Exchange (ETDEWEB)

    Rafferty, Kevin

    2003-03-01

    Many of the communities co-located with geothermal resources are very small and as a result the buildings they contain tend to be small as well. Generally, small buildings (10,000 ft2) use heating systems which are not hot water based. Since geothermal district heating systems deliver hot water, the costs associated with the conversion of small building heating systems to use hot water for heating is an issue of great influence in terms of the potential development of such systems. This paper examines the typical retrofit costs associated with conversion of small buildings and the level of savings necessary to attract the interest of owners. In general, the prospects for connection of such buildings based only on energy savings is not positive.

  8. The economics of connecting of small buildings to geothermal district heating systems

    Energy Technology Data Exchange (ETDEWEB)

    Rafferty, Kevin

    2001-01-01

    Many of the communities co-located with geothermal resources are very small and as a result the buildings they contain tend to be small as well. Generally, small buildings (10,000 ft2) use heating systems which are not hot water based. Since geothermal district heating systems deliver hot water, the costs associated with the conversion of small building heating systems to use hot water for heating is an issue of great influence in terms of the potential development of such systems. This paper examines the typical retrofit costs associated with conversion of small buildings and the level of savings necessary to attract the interest of owners. In general, the prospects for connection of such buildings based only on energy savings is not positive.

  9. Preliminary business plan: Plzen district heating system upgrade

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-06-01

    The district heating system of the City of Plzen, Czech Republic, needs to have physical upgrades to replace aging equipment and to comply with upcoming environmental regulations. Also, its ownership and management are being changed as a result of privatization. As majority owner, the City has the primary goal of ensuring that the heating needs of its customers are met as reliably and cost-effectively as possible. This preliminary business plan is part of the detailed analysis (5 reports in all) done to assist the City in deciding the issues. Preparation included investigation of ownership, management, and technology alternatives; estimation of market value of assets and investment requirements; and forecasting of future cash flow. The district heating system consists of the Central Plzen cogeneration plant, two interconnected heating plants [one supplying both hot water and steam], three satellite heating plants, and cooperative agreements with three industrial facilities generating steam and hot water. Most of the plants are coal-fired, with some peaking units fired by fuel oil.

  10. Thermal performance analysis of a direct-expansion solar-assisted heat pump water heater

    International Nuclear Information System (INIS)

    Kong, X.Q.; Zhang, D.; Li, Y.; Yang, Q.M.

    2011-01-01

    A direct-expansion solar-assisted heat pump water heater (DX-SAHPWH) is described, which can supply hot water for domestic use during the whole year. The system mainly employs a bare flat-plate collector/evaporator with a surface area of 4.2 m 2 , an electrical rotary-type hermetic compressor, a hot water tank with the volume of 150 L and a thermostatic expansion valve. R-22 is used as working fluid in the system. A simulation model based on lumped and distributed parameter approach is developed to predict the thermal performance of the system. Given the structure parameters, meteorological parameters, time step and final water temperature, the numerical model can output operational parameters, such as heat capacity, system COP and collector efficiency. Comparisons between the simulation results and the experimental measurements show that the model is able to give satisfactory predictions. The effect of various parameters, including solar radiation, ambient temperature, wind speed and compressor speed, has been analyzed on the thermal performance of the system. -- Highlights: ► A direct-expansion solar-assisted heat pump water heater (DX-SAHPWH) is described. ► A simulation model based on lumped and distributed parameter approach is developed to predict the thermal performance of the system. ► The numerical model can output operational parameters, such as heat capacity, system COP and collector efficiency. ► Comparisons between the simulation results and the experimental measurements show that the model is able to give satisfactory predictions. ► The effect of various parameters has been analyzed on the thermal performance of the system.

  11. Solar-heating and hot water system--St. Louis, Missouri

    Science.gov (United States)

    1981-01-01

    Sunlight supplies about half heat energy needs of small office. System includes six tilt-adjustable commercial collectors and 1,000 gallon energy storage tank. Report contains description of system and components, drawings and photographs, manufacturer's data, and related material.

  12. Design of an additional heat sink based on natural circulation in pressurized water reactors

    International Nuclear Information System (INIS)

    Frischengruber, Kurt; Solanilla, Roberto; Fernandez, Ricardo; Blumenkrantz, Arnaldo; Castano, Jorge

    1989-01-01

    Residual heat removal through the steam generators in Nuclear Power Plant with pressurized water reactors (PWR) or pressurized heavy water reactors (PHWR in pressured vessel or pressured tube types) requires the maintenance of the steam generator inventory and the availability of and appropriate heat sink, which are based on the operability of the steam generators feedwater system. This paper describes the conceptual design of an assured heat removal system which includes only passive elements and is based on natural circulation. The system can supplement the original systems of the plant. The new system includes a condenser/boiler heat exchanger to condense the steam produced in the steam generator, transferring the heat to the water of an open pool at atmospheric pressure. The condensed steam flows back to the steam generators by natural circulation effects. The performance of an Atucha type PHWR nuclear power station with and without the proposed system is calculated in an emergency power case for the first 5000 seconds after the incident. The analysis shows that the proposed system offers the possibility to cool-down the plant to a low energy state during several hours and avoids the repeated actuation of the primary and secondary system safety valves. (Author) [es

  13. Heat pipe based cold energy storage systems for datacenter energy conservation

    International Nuclear Information System (INIS)

    Singh, Randeep; Mochizuki, Masataka; Mashiko, Koichi; Nguyen, Thang

    2011-01-01

    In the present paper, design and economics of the novel type of thermal control system for datacenter using heat pipe based cold energy storage has been proposed and discussed. Two types of cold energy storage system namely: ice storage system and cold water storage system are explained and sized for datacenter with heat output capacity of 8800 kW. Basically, the cold energy storage will help to reduce the chiller running time that will save electricity related cost and decrease greenhouse gas emissions resulting from the electricity generation from non-renewable sources. The proposed cold energy storage system can be retrofit or connected in the existing datacenter facilities without major design changes. Out of the two proposed systems, ice based cold energy storage system is mainly recommended for datacenters which are located in very cold locations and therefore can offer long term seasonal storage of cold energy within reasonable cost. One of the potential application domains for ice based cold energy storage system using heat pipes is the emergency backup system for datacenter. Water based cold energy storage system provides more compact size with short term storage (hours to days) and is potential for datacenters located in areas with yearly average temperature below the permissible cooling water temperature (∼25 o C). The aforesaid cold energy storage systems were sized on the basis of metrological conditions in Poughkeepsie, New York. As an outcome of the thermal and cost analysis, water based cold energy storage system with cooling capability to handle 60% of datacenter yearly heat load will provide an optimum system size with minimum payback period of 3.5 years. Water based cold energy storage system using heat pipes can be essentially used as precooler for chiller. Preliminary results obtained from the experimental system to test the capability of heat pipe based cold energy storage system have provided satisfactory outcomes and validated the proposed

  14. Engineering Design and Economic Analysis of Air Source Heat Pump Assisted Solar Water Heating System%热泵+太阳能热水系统的工程设计与经济分析

    Institute of Scientific and Technical Information of China (English)

    李永华

    2013-01-01

    以空气源热泵为辅助热源的太阳能集中热水系统,不仅节能效率高,而且能保证全天候连续热水供应,是近年来太阳能利用的发展方向之一。淮海工学院学生浴室采用了空气源热泵辅助太阳能热水系统,设计用水人数17000人,日需热水量184 t。介绍了该热水系统的工作原理及设计计算,并对5种热水工程方案从初期投资和运行费用方面进行了详细的经济性分析,结果表明:以空气源热泵为辅助热源的热水方案较其他方案具有更好的经济、环保效益。%The high energy-efficient solar energy water heating system in conjunction with air source heat pump, supplying all-weather continuous hot water, is one of the developing direction of solar energy utilization in recent years. Students ’ Bathroom of Huaihai Institute of Technology use solar water heating system assisted with air source heat pump for 17000 students, requiring 184 tons of hot water every day. The working principle and design calculation of hot water system are expounded with detailed analysis of the initial investment and operating costs for five kinds of heating water engineering solutions. Results show that air source heat pump as auxiliary heat source has better economic and environmental benefits.

  15. Reduction of Energy Consumption and CO2 Emissions in Domestic Water Heating by Means of Direct Expansion Solar Assisted Heat Pump

    International Nuclear Information System (INIS)

    Baleta, J.; Curko, T.; Cutic, T.; Pasanec, J.; Soldo, V.

    2012-01-01

    Domestic water heating in households sector is usually performed by either fossil fuel fired or electric boilers. Both the combustion process of the former and large electricity consumption of the latter strongly influence overall greenhouse gas emissions. Moreover, very high specific heat of water requires large quantity of energy for water heating making a significant impact on the overall energy consumption in the households sector whose total consumption of 80,81 PJ equals to 19,6% of total primary energy supply in Croatia in 2010. Considering the mentioned impact on energy consumption and CO 2 emissions as well as goals set by European Commission (so called 20-20-20), new technologies based on renewable energy sources are more than welcome in the field of domestic water heating. Direct expansion solar assisted heat pump is presented in this paper. Its working principle is based on single-stage vapour-compression cycle. Representing a gradual step to commercial application with a water tank of 300 l, the developed mobile unit is designed as a test rig enabling all necessary measurements to evaluate potential of solar irradiation for domestic water heating on various locations. Besides the unit description, trial testing results are presented and analyzed as well as a basic comparison of CO 2 emissions between solar assisted heat pump and conventionally used water heating systems. Taking into account both the decentralized water heating and favourable climatic conditions (especially along the Croatian Adriatic coast) as well as rising fossil fuel prices, it is expected that solar assisted heat pumps will be commercialized in the near future.(author)

  16. Solar/electric heating systems for the future energy system

    Energy Technology Data Exchange (ETDEWEB)

    Furbo, S.; Dannemand, M.; Perers, B. [and others

    2013-05-15

    The aim of the project is to elucidate how individual heating units for single family houses are best designed in order to fit into the future energy system. The units are based on solar energy, electrical heating elements/heat pump, advanced heat storage tanks and advanced control systems. Heat is produced by solar collectors in sunny periods and by electrical heating elements/heat pump. The electrical heating elements/heat pump will be in operation in periods where the heat demand cannot be covered by solar energy. The aim is to use the auxiliary heating units when the electricity price is low, e.g. due to large electricity production by wind turbines. The unit is equipped with an advanced control system where the control of the auxiliary heating is based on forecasts of the electricity price, the heat demand and the solar energy production. Consequently, the control is based on weather forecasts. Three differently designed heating units are tested in a laboratory test facility. The systems are compared on the basis of: 1) energy consumption for the auxiliary heating; 2) energy cost for the auxiliary heating; 3) net utilized solar energy. Starting from a normal house a solar combi system (for hot water and house heating) can save 20-30% energy cost, alone, depending on sizing of collector area and storage volume. By replacing the heat storage with a smart tank based on electric heating elements and a smart control based on weather/load forecast and electricity price information 24 hours ahead, another 30-40% can be saved. That is: A solar heating system with a solar collector area of about 10 m{sup 2}, a smart tank based on electric heating element and a smart control system, can reduce the energy costs of the house by at least 50%. No increase of heat storage volume is needed to utilize the smart control. The savings in % are similar for different levels of building insulation. As expected a heat pump in the system can further reduce the auxiliary electricity

  17. IMPROVEMENT OF SYSTEMS OF TECHNICAL WATER SUPPLY WITH COOLING TOWERS FOR HEAT POWER PLANTS TECHNICAL AND ECONOMIC INDICATORS PERFECTION. Part 2

    Directory of Open Access Journals (Sweden)

    Yu. A. Zenovich-Leshkevich-Olpinskiy

    2016-01-01

    Full Text Available The method of calculation of economic efficiency that can be universal and is suitable for feasibility study of modernization of irrigation and water distribution system of cooling towers has been developed. The method takes into account the effect of lower pressure exhaust steam in the condenser by lowering the temperature of the cooling water outlet of a cooling tower that aims at improvement of technical and economic indicators of heat power plants. The practical results of the modernization of irrigation and water distribution system of a cooling tower are presented. As a result, the application of new irrigation and water distribution systems of cooling towers will make it possible to increase the cooling efficiency by more than 4 оС and, therefore, to obtain the fuel savings by improving the vacuum in the turbine condensers. In addition, the available capacity of CHP in the summer period is increased. The results of the work, the experience of modernization of irrigation and water distribution systems of the Gomel CHP-2 cooling towers system, as well as the and methods of calculating of its efficiency can be disseminated for upgrading similar facilities at the power plants of the Belarusian energy system. Some measures are prosed to improve recycling systems, cooling towers and their structures; such measures might significantly improve the reliability and efficiency of technical water supply systems of heat power plants.

  18. Optimal study of a solar air heating system with pebble bed energy storage

    International Nuclear Information System (INIS)

    Zhao, D.L.; Li, Y.; Dai, Y.J.; Wang, R.Z.

    2011-01-01

    Highlights: → Use two kinds of circulation media in the solar collector. → Air heating and pebble bed heat storage are applied with different operating modes. → Design parameters of the system are optimized by simulation program. → It is found that the system can meet 32.8% of the thermal energy demand in heating season. → Annual solar fraction aims to be 53.04%. -- Abstract: The application of solar air collectors for space heating has attracted extensive attention due to its unique advantages. In this study, a solar air heating system was modeled through TRNSYS for a 3319 m 2 building area. This air heating system, which has the potential to be applied for space heating in the heating season (from November to March) and hot water supply all year around in North China, uses pebble bed and water storage tank as heat storage. Five different working modes were designed based on different working conditions: (1) heat storage mode, (2) heating by solar collector, (3) heating by storage bed, (4) heating at night and (5) heating by an auxiliary source. These modes can be operated through the on/off control of fan and auxiliary heater, and through the operation of air dampers manually. The design, optimization and modification of this system are described in this paper. The solar fraction of the system was used as the optimization parameter. Design parameters of the system were optimized by using the TRNSYS program, which include the solar collector area, installation angle of solar collector, mass flow rate through the system, volume of pebble bed, heat transfer coefficient of the insulation layer of the pebble bed and water storage tank, height and volume of the water storage tank. The TRNSYS model has been verified by data from the literature. Results showed that the designed solar system can meet 32.8% of the thermal energy demand in the heating season and 84.6% of the energy consumption in non-heating season, with a yearly average solar fraction of 53.04%.

  19. Recovery of Water from Boiler Flue Gas Using Condensing Heat Exchangers

    Energy Technology Data Exchange (ETDEWEB)

    Edward Levy; Harun Bilirgen; John DuPoint

    2011-03-31

    Most of the water used in a thermoelectric power plant is used for cooling, and DOE has been focusing on possible techniques to reduce the amount of fresh water needed for cooling. DOE has also been placing emphasis on recovery of usable water from sources not generally considered, such as mine water, water produced from oil and gas extraction, and water contained in boiler flue gas. This report deals with development of condensing heat exchanger technology for recovering moisture from flue gas from coal-fired power plants. The report describes: (1) An expanded data base on water and acid condensation characteristics of condensing heat exchangers in coal-fired units. This data base was generated by performing slip stream tests at a power plant with high sulfur bituminous coal and a wet FGD scrubber and at a power plant firing high-moisture, low rank coals. (2) Data on typical concentrations of HCl, HNO{sub 3} and H{sub 2}SO{sub 4} in low temperature condensed flue gas moisture, and mercury capture efficiencies as functions of process conditions in power plant field tests. (3) Theoretical predictions for sulfuric acid concentrations on tube surfaces at temperatures above the water vapor dewpoint temperature and below the sulfuric acid dew point temperature. (4) Data on corrosion rates of candidate heat exchanger tube materials for the different regions of the heat exchanger system as functions of acid concentration and temperature. (5) Data on effectiveness of acid traps in reducing sulfuric acid concentrations in a heat exchanger tube bundle. (6) Condensed flue gas water treatment needs and costs. (7) Condensing heat exchanger designs and installed capital costs for full-scale applications, both for installation immediately downstream of an ESP or baghouse and for installation downstream of a wet SO{sub 2} scrubber. (8) Results of cost-benefit studies of condensing heat exchangers.

  20. Recovery of Water from Boiler Flue Gas Using Condensing Heat Exchangers

    Energy Technology Data Exchange (ETDEWEB)

    Levy, Edward; Bilirgen, Harun; DuPont, John

    2011-03-31

    Most of the water used in a thermoelectric power plant is used for cooling, and DOE has been focusing on possible techniques to reduce the amount of fresh water needed for cooling. DOE has also been placing emphasis on recovery of usable water from sources not generally considered, such as mine water, water produced from oil and gas extraction, and water contained in boiler flue gas. This report deals with development of condensing heat exchanger technology for recovering moisture from flue gas from coal-fired power plants. The report describes: • An expanded data base on water and acid condensation characteristics of condensing heat exchangers in coal-fired units. This data base was generated by performing slip stream tests at a power plant with high sulfur bituminous coal and a wet FGD scrubber and at a power plant firing highmoisture, low rank coals. • Data on typical concentrations of HCl, HNO{sub 3} and H{sub 2}SO{sub 4} in low temperature condensed flue gas moisture, and mercury capture efficiencies as functions of process conditions in power plant field tests. • Theoretical predictions for sulfuric acid concentrations on tube surfaces at temperatures above the water vapor dewpoint temperature and below the sulfuric acid dew point temperature. • Data on corrosion rates of candidate heat exchanger tube materials for the different regions of the heat exchanger system as functions of acid concentration and temperature. • Data on effectiveness of acid traps in reducing sulfuric acid concentrations in a heat exchanger tube bundle. • Condensed flue gas water treatment needs and costs. • Condensing heat exchanger designs and installed capital costs for full-scale applications, both for installation immediately downstream of an ESP or baghouse and for installation downstream of a wet SO{sub 2} scrubber. • Results of cost-benefit studies of condensing heat exchangers.

  1. The use of helical heat exchanger for heat recovery domestic water-cooled air-conditioners

    International Nuclear Information System (INIS)

    Yi Xiaowen; Lee, W.L.

    2009-01-01

    An experimental study on the performance of a domestic water-cooled air-conditioner (WAC) using tube-in-tube helical heat exchanger for preheating of domestic hot water was carried out. The main aims are to identify the comprehensive energy performance (space cooling and hot water preheating) of the WAC and the optimum design of the helical heat exchanger taking into account the variation in tap water flow rate. A split-type WAC was set up for experimental study at different indoor and outdoor conditions. The cooling output, the amount of recovered heat, and the power consumption for different hot water flow rates were measured. The experimental results showed that the cooling coefficient of performance (COP) of the WAC improves with the inclusion of the heat recovery option by a minimum of 12.3%. This can be further improved to 20.6% by an increase in tap water flow rate. Same result was observed for the comprehensive COP of the WAC. The maximum achievable comprehensive COP was 4.92 when the tap water flow rate was set at 7.7 L/min. The overall heat transfer coefficient of the helical heat exchanger under various operating conditions were determined by Wilson plot. A mathematical model relating the over all heat transfer coefficient to the outer pipe diameter was established which provides a convenient way of optimising the design of the helical heat exchanger

  2. Field Performance of Heat Pump Water Heaters in the Northeast

    Energy Technology Data Exchange (ETDEWEB)

    Shapiro, Carl [Consortium for Advanced Residential Buildings, Norwalk, CT (United States); Puttagunta, Srikanth [Consortium for Advanced Residential Buildings, Norwalk, CT (United States)

    2016-02-01

    Heat pump water heaters (HPWHs) are finally entering the mainstream residential water heater market. Potential catalysts are increased consumer demand for higher energy efficiency electric water heating and a new Federal water heating standard that effectively mandates use of HPWHs for electric storage water heaters with nominal capacities greater than 55 gallons. When compared to electric resistance water heating, the energy and cost savings potential of HPWHs is tremendous. Converting all electric resistance water heaters to HPWHs could save American consumers 7.8 billion dollars annually ($182 per household) in water heating operating costs and cut annual residential source energy consumption for water heating by 0.70 quads.

  3. Thermal Interface Evaluation of Heat Transfer from a Pumped Loop to Titanium-Water Thermosyphons

    Science.gov (United States)

    Jaworske, Donald A.; Sanzi, James L.; Gibson, Marc A.; Sechkar, Edward A.

    2009-01-01

    Titanium-water thermosyphons are being considered for use in the heat rejection system for lunar outpost fission surface power. Key to their use is heat transfer between a closed loop heat source and the heat pipe evaporators. This work describes laboratory testing of several interfaces that were evaluated for their thermal performance characteristics, in the temperature range of 350 to 400 K, utilizing a water closed loop heat source and multiple thermosyphon evaporator geometries. A gas gap calorimeter was used to measure heat flow at steady state. Thermocouples in the closed loop heat source and on the evaporator were used to measure thermal conductance. The interfaces were in two generic categories, those immersed in the water closed loop heat source and those clamped to the water closed loop heat source with differing thermal conductive agents. In general, immersed evaporators showed better overall performance than their clamped counterparts. Selected clamped evaporator geometries offered promise.

  4. Heating Water with Solar Energy Costs Less at the Phoenix Federal Correctional Institution

    Energy Technology Data Exchange (ETDEWEB)

    None

    2004-09-01

    A large solar thermal system installed at the Phoenix Federal Correctional Institution (FCI) in 1998 heats water for the prison and costs less than buying electricity to heat that water. This renewable energy system provides 70% of the facility's annual hot water needs. The Federal Bureau of Prisons did not incur the up-front cost of this system because it was financed through an Energy Savings Performance Contract (ESPC). The ESPC payments are 10% less than the energy savings so that the prison saves an average of $6,700 per year, providing an immediate payback. The solar hot water system produces up to 50,000 gallons of hot water daily, enough to meet the needs of 1,250 inmates and staff who use the kitchen, shower, and laundry facilities. This publication details specifications of the parabolic trough solar system and highlights 5 years of measured performance data.

  5. Critical heat flux analysis on change of plate temperature and cooling water flow rate for rectangular narrow gap with bilateral-heated cases

    International Nuclear Information System (INIS)

    M Hadi Kusuma; Mulya Juarsa; Anhar Riza Antariksawan

    2013-01-01

    Boiling heat transfer phenomena on rectangular narrow gap was related to the safety of nuclear reactors. Research done in order to study the safety of nuclear reactors in particular relating to boiling heat transfer and useful on the improvement of next-generation reactor designs. The research focused on calculation of the heat flux during the cooling process in rectangular narrow gap size 1.0 mm. with initial temperatures 200°C. 400°C, and 600°C, also the flow rates of cooling water 0,1 liters/second. 0,2 liters/second. and 0,3 liters/second. Experiments carried out by injecting water at a certain flow rate with the water temperature 85°C. Transient temperature measurement data recorded by the data acquisition system. Transient temperature measurement data is used to calculate the flux of heat gain is then used to obtain the heat transfer coefficient. This research aimed to obtain the correlation between critical heat flux and heat transfer coefficient to changes in temperatures and water flow rates for bilaterally-heated cases on rectangular narrow gap. The results obtained for a constant cooling water flow rate, critical heat flux will increase when hot plate temperature also increased. While on a constant hot plate temperature, coefficient heat transfer will increase when cooling water flow rate also increased. Thus it can be said that the cooling water flow rate and temperature of the hot plate has a significant effect on the critical heat flux and heat transfer coefficient resulted in quenching process of vertical rectangular narrow gap with double-heated cases. (author)

  6. Investigations of Intelligent Solar Heating Systems for Single Family House

    DEFF Research Database (Denmark)

    Andersen, Elsa; Chen, Ziqian; Fan, Jianhua

    2014-01-01

    Three differently designed intelligent solar heating systems are investigated experimentally in a test facility. The systems provide all the needed yearly heating demand in single family houses. The systems are based on highly stratified tanks with variable auxiliary heated volumes. The tank is a......, the control strategy of intelligent solar heating systems is investigated and the yearly auxiliary energy use of the systems and the electricity price for supplying the consumers with domestic hot water and space heating are calculated....... systems.The system will be equipped with an intelligent control system where the control of the electrical heating element(s)/heat pump is based on forecasts of the variable electricity price, the heating demand and the solar energy production.By means of numerical models of the systems made in Trnsys......Three differently designed intelligent solar heating systems are investigated experimentally in a test facility. The systems provide all the needed yearly heating demand in single family houses. The systems are based on highly stratified tanks with variable auxiliary heated volumes. The tank...

  7. WEXA: exergy analysis for increasing the efficiency of air/water heat pumps - Final report

    Energy Technology Data Exchange (ETDEWEB)

    Gasser, L.; Wellig, B.; Hilfiker, K.

    2008-04-15

    This comprehensive final report for the Swiss Federal Office of Energy (SFOE) presents the results of a study at the made by the Engineering and Architecture department at the Lucerne University of Applied Sciences and Arts. The subject of the WEXA study (Waermepumpen-Exergie-Analyse - heat pump exergy analysis) is the analysis of the operation of air/water heat-pumps using exergy analysis methods. The basic thermodynamics of heating systems using heat-pumps is discussed. The exergy analyses and exergy balances for the various components and processes of an air/water heat-pump are presented and discussed. Comparisons are presented for heat-pumps with on/off and continuous control systems for their compressors and fans. The paper is concluded with a collection of appendices on the subject.

  8. Containment heat removal system

    International Nuclear Information System (INIS)

    Wade, G.E.; Barbanti, G.; Gou, P.F.; Rao, A.S.; Hsu, L.C.

    1992-01-01

    This patent describes a nuclear system of a type including a containment having a nuclear reactor therein, the nuclear reactor including a pressure vessel and a core in the pressure vessel, the system. It comprises a gravity pool of coolant disposed at an elevation sufficient to permit a flow of coolant into the nuclear reactor pressure vessel against a predetermined pressure within the nuclear reactor pressure vessel; means for reducing a pressure of steam in the nuclear reactor pressure vessel to a value less than the predetermined pressure in the event of a nuclear accident, the means including a depressurization valve connected to the pressure vessel, the means further including steam heat dissipating means such dissipating means including a suppression pool; a supply of water in the suppression pool, there being a headspace in the suppression pool above the water supply; a substantial amount of air in the head space; means for feeding pressurized steam from the nuclear reactor pressure vessel to a location under a surface of the supply of water, the supply of water being effective to absorb heat sufficient to reduce steam pressure below the predetermined pressure; and a check valve for communicating the headspace with the containment, the check valve being oriented to vent air in the headspace to the containment when a pressure in the headspace exceeds a pressure in the containment by a predetermined pressure differential

  9. Hybrid heat recovery - flat plate Stirling engine system

    International Nuclear Information System (INIS)

    Bogdanizh, A.M.; Budin, R.; Sutlovizh, I.

    2000-01-01

    In this paper, the possibility of process condensate heat recovery for boiler water preheating as well as for combined heat and power production for chosen process in textile industry has been investigated. The garment industry requires low pressure process steam or hot water for which production expensive fossil fuel should be used. Fuel usage can be reduced by various energy conservation methods. During the process a great quantity of hot condensate or waste hot water is rejected in the sewage system. To reduce heat wastes and improve technological process this condensate could be returned to the boiler for feed water preheating. When 60% condensate is returned to the steam generator about 8 % natural gas is saved. The rest of the condensate should be used for driving low temperature flat plate Stirling motor the advantage of the flat plate Stirling engine is ability to work at low temperatures. This engine produces electrical energy which can put in motion an electrogenerator in the same plant. While Stirling engine can be used electrical power and economical effect could be much greater using such a hybrid system the process waste heat is not only converted into useful work but at the same time thermal pollution is greatly diminished. (Author)

  10. Physical and chemical parameter correlations with technical and technological characteristics of heating systems and the presence of Legionella spp. in the hot water supply.

    Science.gov (United States)

    Rakić, Anita; Štambuk-Giljanović, Nives

    2016-02-01

    The purpose of this study was to evaluate the prevalence of Legionella spp. and compare the quality of hot water between four facilities for accommodation located in Southern Croatia (the Split-Dalmatian County). The research included data collection on the technical and technological characteristics in the period from 2009 to 2012. The survey included a type of construction material for the distribution and internal networks, heating system water heater type, and water consumption. Changes in water quality were monitored by determination of the physical and chemical parameters (temperature, pH, free chlorine residual concentrations, iron, zinc, copper and manganese) in the samples, as well as the presence and concentration of bacteria Legionella spp. The temperature is an important factor for the development of biofilms, and it is in negative correlation with the appearance of Legionella spp. Positive correlations between the Fe and Zn concentrations and Legionella spp. were established, while the inhibitory effect of a higher Cu concentration on the Legionella spp. concentration was proven. Legionella spp. were identified in 38/126 (30.2%) of the water samples from the heating system with zinc-coated pipes, as well as in 78/299 (26.1%) of the samples from systems with plastic pipes. A similar number of Legionella spp. positive samples were established regardless of the type of the water heating system (central or independent). The study confirms the necessity of regular microbial contamination monitoring of the drinking water distribution systems (DWDSs).

  11. A new test procedure to evaluate the performance of substations for collective heating systems

    Science.gov (United States)

    Baetens, Robin; Verhaert, Ivan

    2017-11-01

    The overall heat demand of a single dwelling, existing out of space heating and domestic hot water production, decreases due to higher insulation rates. Because of this, investing in efficient and renewable heat generation becomes less interesting. Therefore, to incorporate renewables or residual heat on a larger scale, district heating or collective heating systems grow in importance. Within this set-up, the substation is responsible for the interaction between local demand for comfort and overall energy performance of the collective heating system. Many different configurations of substations exist, which influence both local comfort and central system performance. Next to that, also hybrids exist with additional local energy input. To evaluate performance of such substations, a new experimental-based test procedure is developed in order to evaluate these different aspects, characterized by the two roles a substation has, namely as heat generator and as heat consumer. The advantage of this approach is that an objective comparison between individual and central systems regarding performance on delivering local comfort can be executed experimentally. The lab set-up consists out of three different subsystems, namely the central system, the domestic hot water consumption and the local space heating. The central system can work with different temperature regimes and control strategies, as these aspects have proven to have the largest influence on actual performance. The domestic hot water system is able to generate similar tap profiles according to eco-design regulation for domestic hot water generation. The space heating system is able to demand a modular heat load.

  12. A new test procedure to evaluate the performance of substations for collective heating systems

    Directory of Open Access Journals (Sweden)

    Baetens Robin

    2017-01-01

    Full Text Available The overall heat demand of a single dwelling, existing out of space heating and domestic hot water production, decreases due to higher insulation rates. Because of this, investing in efficient and renewable heat generation becomes less interesting. Therefore, to incorporate renewables or residual heat on a larger scale, district heating or collective heating systems grow in importance. Within this set-up, the substation is responsible for the interaction between local demand for comfort and overall energy performance of the collective heating system. Many different configurations of substations exist, which influence both local comfort and central system performance. Next to that, also hybrids exist with additional local energy input. To evaluate performance of such substations, a new experimental-based test procedure is developed in order to evaluate these different aspects, characterized by the two roles a substation has, namely as heat generator and as heat consumer. The advantage of this approach is that an objective comparison between individual and central systems regarding performance on delivering local comfort can be executed experimentally. The lab set-up consists out of three different subsystems, namely the central system, the domestic hot water consumption and the local space heating. The central system can work with different temperature regimes and control strategies, as these aspects have proven to have the largest influence on actual performance. The domestic hot water system is able to generate similar tap profiles according to eco-design regulation for domestic hot water generation. The space heating system is able to demand a modular heat load.

  13. Coupled equations for transient water flow, heat flow, and ...

    Indian Academy of Sciences (India)

    interacting processes, including flow of fluids, deformation of porous materials, chemical reactions, and transport of ... systems involving the flow of water, heat, and deformation. Such systems are ..... Defined thus, αI is independent of boundary con- ditions in an ... perature change with free deformation at constant total stress ...

  14. Combined heat pump for sanitary hot water and space heating with CO{sub 2} as refrigerant; Kombineret brugsvands- og rumvarmepumpe med CO{sub 2} som koelemiddel

    Energy Technology Data Exchange (ETDEWEB)

    Schoen Poulsen, C. [Teknologisk Institut (Denmark)

    2006-05-19

    This project report describes the implementation of the Danish project called 'Combined heat pump for sanitary hot water and space heating with CO{sub 2} as refrigerant'. In the course of the project, a combined heat pump has been developed for heating sanitary hot water and producing domestic space heating. The project shows that CO2 has excellent properties in systems where a high temperature is desired on the gas cooler side and that it is possible to combine the production of sanitary hot water with the production of domestic space heating. During the project, a number of system solutions have been analysed and at the end of the project a prototype was built. It was tested in the laboratory according to a current Dutch standard for heat pumps for sanitary hot water. The prototype was constructed without the space heat part which solely has been analysed according to calculations. The reason is that there currently are no applicable European standards for the testing of combined systems and as the total efficiency of the system mainly depends on the temperature out of the gas cooler it was decided not to spend resources on the construction of the combined system in the prototype version of the unit. Instead, a number of proposals have been submitted to how the system with a space heat section could be constructed. The main components used in the prototype (compressor, exchangers, valve, control and tank) are all partly commercially available and therefore focus has been on the system construction. During the project, a number of CFD calculations have been carried out on the gas cooler in the hot water tank and the results show how important it is that the gas cooler is designed and placed correctly. The laboratory tests carried out on the unit show that the COP of the heat pump plant in connection with sanitary hot water tapping (according to Dutch standard) is 1.4 1.5 which is not immediately satisfactory. But when it is considered that the unit is a

  15. Saturated flow boiling heat transfer in water-heated vertical annulus

    International Nuclear Information System (INIS)

    Sun Licheng; Yan Changqi; Sun Zhonning

    2005-01-01

    This paper describes the saturated flow boiling heat transfer characteristics of water at 1 atm and low velocities in water-heated vertical annuli with equivalent diameters of 10 mm and 6 mm. Test section is consisted of two concentric circular tubes outer of which is made of quartz, so the whole test courses can be visualized. There are three main flow patterns of bubble flow, churn flow and churn-annular flow in the annuli, most important of which is churn flow. Flooding is the mechanism of churn flow and churn can enhance the heat transport between steam and water; Among the three factors of mass flux, inlet subcooling and annulus width, the last one has great effect on heat transport, moderately decreasing the annulus width can enhance the heat transfer; Combined annular flow model with theory of flooding and turbulent Prandtl Number, the numerical value of heat flux is given, the shape of test boiling curve and that of calculated by model is very alike, but there is large discrepancy between test data and calculated results, the most possible reason is that some parameters given by fluid flooding model are based on experimental data of common circular tubes, but not of annuli. Doing more research on flooding in annulus, particularly narrow annulus, is necessary for calculating the saturated boiling in annulus. (authors)

  16. Analysis of profitability of using a heat recovery system from grey water discharged from the shower (case study of Poland)

    Science.gov (United States)

    Kordana, Sabina; Słys, Daniel

    2017-11-01

    The paper analyses the profitability of the use of Drain Water Heat Recovery units. An original simulation model was used for this purpose, and a detached residential building located in Poland was selected as the test facility. The conducted analysis proved that the type of the hot water heater has decisive influence on the profitability level of such an investment. Application of the abovementioned technology is particularly profitable, when water is heated with the use of an electrical device. When the energy source in the system is a gas water heater, the obtained calculation results are not as favourable, and the period of investment return in many cases exceeds the expected service life of these devices. Moreover, the analysis demonstrated that the potential energy savings, and thus also the financial savings, may be in both cases increased as a result of simultaneous intake of water from various water taps.

  17. Influencing Swedish homeowners to adopt district heating system

    Energy Technology Data Exchange (ETDEWEB)

    Mahapatra, Krushna; Gustavsson, Leif [Ecotechnology, Mid Sweden University, Akademigatan 1, 831 25 Oestersund (Sweden)

    2009-02-15

    Improved energy efficiency and greenhouse gas mitigation could be achieved by replacing resistance heaters with district heating system. In 2005, only about 8% of the Swedish detached houses had district heating system. The expansion of such systems largely depends on homeowners' adoption decisions. And, to motivate homeowners to adopt district heating, it is essential to understand their decision-making process. In this context, in June 2005 we carried out a questionnaire survey of about 700 homeowners who lived in the city of Oestersund in houses with resistance heaters (baseline survey). About 84% of the respondents did not intend to install a new heating system. Since then these homeowners were influenced by (a) an investment subsidy by the Swedish government to replace resistance heaters with district heating, a brine/water-based heat pump, or a biomass-based heating system and (b) a marketing campaign by the municipality-owned district heating company. This paper analyses how these two measures influenced about 78% of the homeowners to adopt the district heating system. For this purpose we carried out a follow-up survey of the same homeowners in December 2006 (resurvey). Results showed that the investment subsidy and the marketing campaign created a need among the homeowners to adopt a new heating system. The marketing campaign was successful in motivating them to adopt the district heating system. The marketing strategy by the district heating company corresponds to the results obtained in the baseline survey. (author)

  18. Influencing Swedish homeowners to adopt district heating system

    International Nuclear Information System (INIS)

    Mahapatra, Krushna; Gustavsson, Leif

    2009-01-01

    Improved energy efficiency and greenhouse gas mitigation could be achieved by replacing resistance heaters with district heating system. In 2005, only about 8% of the Swedish detached houses had district heating system. The expansion of such systems largely depends on homeowners' adoption decisions. And, to motivate homeowners to adopt district heating, it is essential to understand their decision-making process. In this context, in June 2005 we carried out a questionnaire survey of about 700 homeowners who lived in the city of Ostersund in houses with resistance heaters (baseline survey). About 84% of the respondents did not intend to install a new heating system. Since then these homeowners were influenced by (a) an investment subsidy by the Swedish government to replace resistance heaters with district heating, a brine/water-based heat pump, or a biomass-based heating system and (b) a marketing campaign by the municipality-owned district heating company. This paper analyses how these two measures influenced about 78% of the homeowners to adopt the district heating system. For this purpose we carried out a follow-up survey of the same homeowners in December 2006 (resurvey). Results showed that the investment subsidy and the marketing campaign created a need among the homeowners to adopt a new heating system. The marketing campaign was successful in motivating them to adopt the district heating system. The marketing strategy by the district heating company corresponds to the results obtained in the baseline survey

  19. Influencing Swedish homeowners to adopt district heating system

    Energy Technology Data Exchange (ETDEWEB)

    Mahapatra, Krushna; Gustavsson, Leif [Ecotechnology, Mid Sweden University, Akademigatan 1, 831 25 Oestersund (Sweden)

    2009-02-15

    Improved energy efficiency and greenhouse gas mitigation could be achieved by replacing resistance heaters with district heating system. In 2005, only about 8% of the Swedish detached houses had district heating system. The expansion of such systems largely depends on homeowners' adoption decisions. And, to motivate homeowners to adopt district heating, it is essential to understand their decision-making process. In this context, in June 2005 we carried out a questionnaire survey of about 700 homeowners who lived in the city of Oestersund in houses with resistance heaters (baseline survey). About 84% of the respondents did not intend to install a new heating system. Since then these homeowners were influenced by (a) an investment subsidy by the Swedish government to replace resistance heaters with district heating, a brine/water-based heat pump, or a biomass-based heating system and (b) a marketing campaign by the municipality-owned district heating company. This paper analyses how these two measures influenced about 78% of the homeowners to adopt the district heating system. For this purpose we carried out a follow-up survey of the same homeowners in December 2006 (resurvey). Results showed that the investment subsidy and the marketing campaign created a need among the homeowners to adopt a new heating system. The marketing campaign was successful in motivating them to adopt the district heating system. The marketing strategy by the district heating company corresponds to the results obtained in the baseline survey. (author)

  20. Performance analysis of a solar-assisted swimming pool heating system

    Energy Technology Data Exchange (ETDEWEB)

    Alkhamis, A I; Sherif, S A [Miami Univ., Coral Gables, FL (United States). Dept. of Mechanical Engineering

    1991-12-31

    This paper discusses feasibility studies for a solar-assisted heating system using a computer simulation program. The solar heating is accomplished by employing hot water generated by heat exchange with the solar collector working fluid. The performance of the system is analysed from both thermodynamic and economic standpoints and general conclusions are reached. 17 refs., 7 figs.

  1. Discussion of the Integrate Designs between Solar Energy Water Heating System and Air-source Heat Pump%空气源热泵与太阳能热水系统集成设计探讨

    Institute of Scientific and Technical Information of China (English)

    王伟; 南晓红; 马俊; 李飞

    2011-01-01

    对不同地区应用的几种不同形式空气源热泵辅助型太阳能热水系统设计方案进行介绍探讨,并以其为基础提出一种新的空气源热泵与太阳能热水系统集成的多功能系统设计方案。总结了不同地区、不同形式空气源热泵辅助型太阳能热水系统的设计方案、特点及新集成系统运行模式等,为我国不同地区应用此类系统时选择具体设计方案提供参考。%In this paper,different designs of the solar energy water heating system aided by air-source heat pump(SEWH-ASHP) are introduced and discussed,then a new integrate design between solar energy water heating system and air-source heat pump is given.Characters of different designs of the solar energy water heating system aided by air-source heat pump in different area are summed and the operational modes of the integrate system are analysed,which would be a useful reference to chose for designing and using the system of SEWH-ASHP and integrate system in different areas in China.

  2. Investigating the interactions of decentralized and centralized wastewater heat recovery systems.

    Science.gov (United States)

    Sitzenfrei, Robert; Hillebrand, Sebastian; Rauch, Wolfgang

    2017-03-01

    In the urban water cycle there are different sources for extracting energy. In addition to potential and chemical energy in the wastewater, thermal energy can also be recovered. Heat can be recovered from the wastewater with heat exchangers that are located decentralized and/or centralized at several locations throughout the system. It can be recovered directly at the source (e.g. in the showers and bathrooms), at building block level (e.g. warm water tanks collecting all grey water), in sewers or at the wastewater treatment plant. However, an uncoordinated installation of systems on such different levels can lead to competing technologies. To investigate these interactions, a modelling environment is set up, tested and calibrated based on continuous sewer temperature and flow measurements. With that approach different heat recovery scenarios on a household level (decentralized) and of in-sewer heat recovery (centralized) are investigated. A maximum performance drop of 40% for a centralized energy recovery system was estimated when all bathrooms are equipped with decentralized recovery systems. Therefore, the proposed modelling approach is suitable for testing different future conditions and to identify robust strategies for heat recovery systems from wastewater.

  3. 'Pioneer' - A controlled air-water heat pump for the replacement of oil-fired and electric heating systems; Geregelte Waermepumpe Pioneer. Geregelte Luft-Wasser-Waermepumpe fuer Sanierungen von Oel- und Elektroheizungen - Schlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Boeckh, P. von; Borer, M.; Borer, T. [Fachhochschule beider Basel FHBB, Dept. Industrie, Abtlg. Maschinenbau, Muttenz (Switzerland); Eggenberger, H.J. [Solartis GmbH, WP-Versuchslabor EICH, Fuellinsdorf (Switzerland)

    2005-07-01

    This final report for the Swiss Federal Office of Energy (SFOE) presents the results of a project that involved the development of an air-water heat pump system that could replace existing oil-fired and electric heating systems. The system features variable-frequency compressor and ventilator drives and was tested on a special test bed that provided appropriately prepared primary air. The measurements and optimisations made included the definition of optimal parameters for ventilator and de-icing system, measurement of performance coefficients and noise emissions as well as on the suitability of the system for hot-water generation. The authors quote figures that show that the performance of the variable-speed system is much better than systems running in stop-and-go mode.

  4. 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.

  5. An assessment of efficient water heating options for an all-electric single family residence in a mixed-humid climate

    Science.gov (United States)

    Balke, Elizabeth C.; Healy, William M.; Ullah, Tania

    2016-01-01

    An evaluation of a variety of efficient water heating strategies for an all-electric single family home located in a mixed-humid climate is conducted using numerical modeling. The strategies considered include various combinations of solar thermal, heat pump, and electric resistance water heaters. The numerical model used in the study is first validated against a year of field data obtained on a dual-tank system with a solar thermal preheat tank feeding a heat pump water heater that serves as a backup. Modeling results show that this configuration is the most efficient of the systems studied over the course of a year, with a system coefficient of performance (COPsys) of 2.87. The heat pump water heater alone results in a COPsys of 1.9, while the baseline resistance water heater has a COPsys of 0.95. Impacts on space conditioning are also investigated by considering the extra energy consumption required of the air source heat pump to remove or add heat from the conditioned space by the water heating system. A modified COPsys that incorporates the heat pump energy consumption shows a significant drop in efficiency for the dual tank configuration since the heat pump water heater draws the most heat from the space in the heating season while the high temperatures in the solar storage tank during the cooling season result in an added heat load to the space. Despite this degradation in the COPsys, the combination of the solar thermal preheat tank and the heat pump water heater is the most efficient option even when considering the impacts on space conditioning. PMID:27990058

  6. An assessment of efficient water heating options for an all-electric single family residence in a mixed-humid climate.

    Science.gov (United States)

    Balke, Elizabeth C; Healy, William M; Ullah, Tania

    2016-12-01

    An evaluation of a variety of efficient water heating strategies for an all-electric single family home located in a mixed-humid climate is conducted using numerical modeling. The strategies considered include various combinations of solar thermal, heat pump, and electric resistance water heaters. The numerical model used in the study is first validated against a year of field data obtained on a dual-tank system with a solar thermal preheat tank feeding a heat pump water heater that serves as a backup. Modeling results show that this configuration is the most efficient of the systems studied over the course of a year, with a system coefficient of performance (COP sys ) of 2.87. The heat pump water heater alone results in a COP sys of 1.9, while the baseline resistance water heater has a COP sys of 0.95. Impacts on space conditioning are also investigated by considering the extra energy consumption required of the air source heat pump to remove or add heat from the conditioned space by the water heating system. A modified COP sys that incorporates the heat pump energy consumption shows a significant drop in efficiency for the dual tank configuration since the heat pump water heater draws the most heat from the space in the heating season while the high temperatures in the solar storage tank during the cooling season result in an added heat load to the space. Despite this degradation in the COP sys , the combination of the solar thermal preheat tank and the heat pump water heater is the most efficient option even when considering the impacts on space conditioning.

  7. Dynamic performance of a novel solar photovoltaic/loop-heat-pipe heat pump system

    International Nuclear Information System (INIS)

    Zhang, Xingxing; Zhao, Xudong; Shen, Jingchun; Xu, Jihuan; Yu, Xiaotong

    2014-01-01

    Highlights: • A transient model was developed to predict dynamic performance of new PV/LHP system. • The model accuracy was validated by experiment giving less than 9% in error. • The new system had basic and advanced performance coefficients of 5.51 and 8.71. • The new system had a COP 1.5–4 times that for conventional heat pump systems. • The new system had higher exergetic efficiency than PV and solar collector systems. - Abstract: Objective of the paper is to present an investigation into the dynamic performance of a novel solar photovoltaic/loop-heat-pipe (PV/LHP) heat pump system for potential use in space heating or hot water generation. The methods used include theoretical computer simulation, experimental verification, analysis and comparison. The fundamental equations governing the transient processes of solar transmission, heat transfer, fluid flow and photovoltaic (PV) power generation were appropriately integrated to address the energy balances occurring in different parts of the system, e.g., glazing cover, PV cells, fin sheet, loop heat pipe, heat pump cycle and water tank. A dedicated computer model was developed to resolve the above grouping equations and consequently predict the system’s dynamic performance. An experimental rig was constructed and operated under the real weather conditions for over one week in Shanghai to evaluate the system living performance, which was undertaken by measurement of various operational parameters, e.g., solar radiation, photovoltaic power generation, temperatures and heat pump compressor consumption. On the basis of the first- (energetic) and second- (exergetic) thermodynamic laws, an overall evaluation approach was proposed and applied to conduct both quantitative and qualitative analysis of the PV/LHP module’s efficiency, which involved use of the basic thermal performance coefficient (COP th ) and the advanced performance coefficient (COP PV/T ) of such a system. Moreover, a simple comparison

  8. Advanced regenerative heat recovery system

    Science.gov (United States)

    Prasad, A.; Jasti, J. K.

    1982-02-01

    A regenerative heat recovery system was designed and fabricated to deliver 1500 scfm preheated air to a maximum temperature of 1600 F. Since this system is operating at 2000 F, the internal parts were designed to be fabricated with ceramic materials. This system is also designed to be adaptable to an internal metallic structure to operate in the range of 1100 to 1500 F. A test facility was designed and fabricated to test this system. The test facility is equipped to impose a pressure differential of up to 27 inches of water column in between preheated air and flue gas lines for checking possible leakage through the seals. The preliminary tests conducted on the advanced regenerative heat recovery system indicate the thermal effectiveness in the range of 60% to 70%. Bench scale studies were conducted on various ceramic and gasket materials to identify the proper material to be used in high temperature applications. A market survey was conducted to identify the application areas for this heat recovery system. A cost/benefit analysis showed a payback period of less than one and a half years.

  9. Research and development of an air-cycle heat-pump water heater. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Dieckmann, J.T.; Erickson, A.J.; Harvey, A.C.; Toscano, W.M.

    1979-10-01

    A prototype reverse Brayton air cycle heat pump water heater has been designed and built for residential applications. The system consists of a compressor/expander, an air-water heat exchanger, an electric motor, a water circulation pump, a thermostat, and fluid management controls. The prototype development program consisted of a market analysis, design study, and development testing. A potential residential market for the new high-efficiency water heater of approximately 480,000 units/y was identified. The retail and installation cost of this water heater is estimated to be between $500 and $600 which is approximately $300 more than a conventional electric water heater. The average payback per unit is less than 3-1/2 y and the average recurring energy cost savings after the payback period is approximately $105/y at the average seasonal coefficient of performance (COP) of 1.7. As part of the design effort, a thermodynamic parametric analysis was performed on the water heater system. It was determined that to obtain a coefficient of performance of 1.7, the isentropic efficiency of both the compressor and the expander must be at least 85%. The selected mechanical configuration is described. The water heater has a diameter of 25 in. and a height of 73 in. The results of the development testing of the prototype water heater system showed: the electrical motor maximum efficiency of 78%; the compressor isentropic efficiency is 95 to 119% and the volumetric efficiency is approximately 85%; the expander isentropic efficiency is approximately 58% and the volumetric efficiency is 92%; a significant heat transfer loss of approximately 16% occurred in the expander; and the prototype heat pump system COP is 1.26 which is less than the design goal of at least 1.7. Future development work is recommended.

  10. Experimental study of gas engine driven air to water heat pump in cooling mode

    International Nuclear Information System (INIS)

    Elgendy, E.; Schmidt, J.

    2010-01-01

    Nowadays a sustainable development for more efficient use of energy and protection of the environment is of increasing importance. Gas engine heat pumps represent one of the most practicable solutions which offer high energy efficiency and environmentally friendly for heating and cooling applications. In this paper, the performance characteristics of gas engine driven heat pump used in water cooling were investigated experimentally without engine heat recovery. The effects of several important factors (evaporator water inlet temperature, evaporator water volume flow rate, ambient air temperature, and engine speed) on the performance of gas engine driven heat pump were studied in a wide range of operating conditions. The results showed that primary energy ratio of the system increased by 22.5% as evaporator water inlet temperature increased from 13 o C to 24 o C. On the other hand, varying of engine speed from 1300 rpm to 1750 rpm led to decrease in system primary energy ratio by 13%. Maximum primary energy ratio has been estimated with a value of two over a wide range of operating conditions.

  11. Experimental investigate of heat transfer for graphene/water nanofluid in micro heat exchanger

    Science.gov (United States)

    Abd Elhafez, S. E.; Abo-Zahhad, E. M.; El-Shazly, A. H.; El-Kady, M. F.

    2017-02-01

    In this investigation, the heat transfer characteristics of graphene nano platelets (GNPs)/water nanofluid were studied in a micro heat exchanger (MHE). The micro heat exchanger performance was also examined. The test setup was worked out in the laminar regime with Reynold numbers varying between 100 and 400GNPs/water nanofluid was prepared three different concentrations (0.025 wt. %, 0.05 wt. % and 0.1 wt. %) using ultrasonic wave. The influence of mass flow rate, inlet temperatures and weight fraction on the overall heat transfer coefficient (U) and logarithmic mean temperature (LMTD) were examined. The results showed considerable enhancement on the overall heat transfer coefficient of graphene/water nanofluid and the MHE effectiveness. A maximum enhancement on overall heat transfer coefficient was reached to 150% at Re=100 by 0.1wt% nanofluid. The effectiveness of micro heat exchanger was enhanced by increase weight fraction of graphene nanoparticle. Moreover, the experimental results showed that 0.1 wt. % GNPs/water nanofluid, flowing through MHE, has had high pressure drop, and pumping power, when it has been compared with 0.5 wt. % and 0.025 wt.%.

  12. Smart solar domestic hot water systems. Development and test; Intelligente solvarmeanlaeg. Udvikling og afproevning

    Energy Technology Data Exchange (ETDEWEB)

    Andersen, E.; Knudsen, S.; Furbo, S.; Vejen, N.K.

    2001-07-01

    The purpose of the project described in this report is to develop and test smart solar domestic hot water systems (SDHW systems) where the energy supply from the auxiliary energy supply system is controlled in a flexible way fitted to the hot water consumption in such a way, that the SDHW systems are suitable for large as well as small hot water demands. In a smart SDHW system the auxiliary energy supply system is controlled in a smart way. The auxiliary energy supply system heats up the water in the hot water tank from the top and only the hot water volume needed by the consumers is heated. Further the water is heated immediately before tapping. The control system includes a number of temperature sensors which cover the temperatures in the auxiliary heated volume. Based on these temperatures the energy content in the hot water tank is calculated. Only water heated to a temperature above 50 deg. C contributes to the total energy content in the hot water tank. Furhter the control system includes a timer that only allows the auxiliary energy supply system to be active in certain time periods and only if the energy content in the hot water tank is lower than wanted. In this way the water in the tank is heated immediately before the expected time of tapping and only the hot water volume needed is heated. The report is divided into five main sections. The sections deals with: Developing and testing storage tanks, laboratory test of SDHW systems based on some of the developed storage tanks, validation of simulation programs for smart solar heating systems, optimisation of system design and control strategy and measurements on two smart SDHW systems installed in single family houses. In all the developed hot water tanks, attempt is made to heat the water in the tank from the top of the tank and not as in traditional tanks where the water is heated from the lowest level of the auxiliary energy supply system, normally a helix or a electrical heating element placed in the

  13. Artificial Neural Networks-Based Software for Measuring Heat Collection Rate and Heat Loss Coefficient of Water-in-Glass Evacuated Tube Solar Water Heaters.

    Science.gov (United States)

    Liu, Zhijian; Liu, Kejun; Li, Hao; Zhang, Xinyu; Jin, Guangya; Cheng, Kewei

    2015-01-01

    Measurements of heat collection rate and heat loss coefficient are crucial for the evaluation of in service water-in-glass evacuated tube solar water heaters. However, conventional measurement requires expensive detection devices and undergoes a series of complicated procedures. To simplify the measurement and reduce the cost, software based on artificial neural networks for measuring heat collection rate and heat loss coefficient of water-in-glass evacuated tube solar water heaters was developed. Using multilayer feed-forward neural networks with back-propagation algorithm, we developed and tested our program on the basis of 915 measured samples of water-in-glass evacuated tube solar water heaters. This artificial neural networks-based software program automatically obtained accurate heat collection rate and heat loss coefficient using simply "portable test instruments" acquired parameters, including tube length, number of tubes, tube center distance, heat water mass in tank, collector area, angle between tubes and ground and final temperature. Our results show that this software (on both personal computer and Android platforms) is efficient and convenient to predict the heat collection rate and heat loss coefficient due to it slow root mean square errors in prediction. The software now can be downloaded from http://t.cn/RLPKF08.

  14. Artificial Neural Networks-Based Software for Measuring Heat Collection Rate and Heat Loss Coefficient of Water-in-Glass Evacuated Tube Solar Water Heaters

    Science.gov (United States)

    Liu, Zhijian; Liu, Kejun; Li, Hao; Zhang, Xinyu; Jin, Guangya; Cheng, Kewei

    2015-01-01

    Measurements of heat collection rate and heat loss coefficient are crucial for the evaluation of in service water-in-glass evacuated tube solar water heaters. However, conventional measurement requires expensive detection devices and undergoes a series of complicated procedures. To simplify the measurement and reduce the cost, software based on artificial neural networks for measuring heat collection rate and heat loss coefficient of water-in-glass evacuated tube solar water heaters was developed. Using multilayer feed-forward neural networks with back-propagation algorithm, we developed and tested our program on the basis of 915measuredsamples of water-in-glass evacuated tube solar water heaters. This artificial neural networks-based software program automatically obtained accurate heat collection rateand heat loss coefficient using simply "portable test instruments" acquired parameters, including tube length, number of tubes, tube center distance, heat water mass in tank, collector area, angle between tubes and ground and final temperature. Our results show that this software (on both personal computer and Android platforms) is efficient and convenient to predict the heat collection rate and heat loss coefficient due to it slow root mean square errors in prediction. The software now can be downloaded from http://t.cn/RLPKF08. PMID:26624613

  15. Energy saving analysis on mine-water source heat pump in a residential district of Henan province, central China

    Science.gov (United States)

    Wang, Hong; Duan, Huanlin; Chen, Aidong

    2018-02-01

    In this paper, the mine-water source heat pump system is proposed in residential buildings of a mining community. The coefficient of performance (COP) and the efficiency of exergy are analyzed. The results show that the COP and exergy efficiency of the mine-water source heat pump are improved, the exergy efficiency of mine-water source heat pump is more than 10% higher than that of the air source heat pump.The electric power conservation measure of “peak load shifting” is also emphasized in this article. It shows that itis a very considerable cost in the electric saving by adopting the trough period electricity to produce hot water. Due to the proper temperature of mine water, the mine-watersource heat pump unit is more efficient and stable in performance, which further shows the advantage of mine-water source heat pump in energy saving and environmental protection. It provides reference to the design of similar heat pump system as well.

  16. The market penetration of solar and heat pump systems in Austria 1991

    International Nuclear Information System (INIS)

    Faninger, G.

    1992-02-01

    The market penetration of solar and heat pump systems in Austria in 1991 shows a high interest for solar systems as well as for swimming-pool heating as for domestic hot-water preparation and also an increase in the field of heat pumps especially for space heating. (author)

  17. Solar Space and Water Heating for School -- Dallas, Texas

    Science.gov (United States)

    1982-01-01

    90 page report gives overview of retrofitted solar space-heating and hot-water system installation for 61-year-old high school. Description, specifications, modifications, plan drawings for roof, three floors, basement, correspondence, and documents are part of report.

  18. Hot sanitary water production with CO_2 heat pumps: Effect of control strategy on system performance and stratification inside the storage tank

    International Nuclear Information System (INIS)

    Tammaro, M.; Mauro, A.W.; Montagud, C.; Corberán, J.M.; Mastrullo, R.

    2016-01-01

    In this work three different control strategies for the production of sanitary hot water by means of an electric heat pump working with CO_2 are investigated. The heat pump is a prototype, here modelled in the vapour-compression software package IMST-ART. By simulating this model, the performance of the heat pump is correlated to the boundary conditions and is scaled to different sizes, namely 1, 1.5, and 2 times larger than the reference system. After having chosen an application for which the load profile of sanitary hot water during the year is known, these heat pumps are simulated in a TRNSYS16 model where the production of sanitary hot water and the consumption are buffered by the presence of a tank. Key parameter in guaranteeing comfort and good performance of the system is the stratification inside the storage tank. The size of the tank necessary to keep a certain level of comfort at the user is then determined through a parametric analysis for each size of the heat pump. The energetic performance is also evaluated for each system in terms of seasonal performance factor. Then, the results obtained are compared with a different system where the heat pump is equipped with an inverter and the circulation pump follows a different control logic. The size of the tank and the seasonal performance factor are therefore determined in this case too. Moreover, a “night&day” control logic is compared to these first two options to have a baseline of comparison in terms of volume of storage needed to guarantee a same level of comfort and performance. To provide information also on the running costs, a parametric analysis was run varying the type of control, the heat pump and the tank sizes for different load profiles. The results show that the size of the heat pump has a significant effect on the comfort of the user, which usually leads to oversizing of the storage tank when the load profile is unknown. With regard to this, the results obtained for the alternative

  19. Evaluation of heat exchange performance for primary pressurized water cooler in HTTR

    International Nuclear Information System (INIS)

    Tochio, Daisuke; Nakagawa, Shigeaki

    2006-01-01

    In High Temperature Engineering Test Reactor (HTTR), the rated thermal power of 30 MW, the generated heat at reactor core is finally dissipated at the air-cooler by way of the heat exchangers of the primary cooling system, such as the primary pressurized water cooler (PPWC) and the intermediate heat exchanger (IHX). The heat exchangers in the primary cooling system are required the heat exchange performance to remove reactor generated heat 30 MW under the condition of reactor coolant outlet temperature 850degC/950degC. Therefore, the heat exchanges are required to satisfy the design criteria of heat exchange performance. In this report, heat exchange performance data of the rise-to-power-up test and the in-service operation for the PPWC in the main cooling system was evaluated. Moreover, the evaluated values were compared with the design values, and it is confirmed that PPWC has the required heat exchange performance in the design. (author)

  20. Evaluation of heat exchange performance for secondary pressurized water cooler in HTTR

    International Nuclear Information System (INIS)

    Tochio, Daisuke; Watanabe, Syuji; Saikusa, Akio; Oyama, Sunao; Nemoto, Takahiro; Hamamoto, Shinpei; Shinohara, Masanori; Isozaki, Minoru; Nakagawa, Shigeaki

    2006-02-01

    In High Temperature Engineering Test Reactor (HTTR), the rated thermal power of 30MW, the generated heat at reactor core is finally dissipated at the air-cooler by way of the heat exchangers of the primary cooling system, such as the intermediate heat exchanger (IHX) and the secondary pressurized water cooler (SPWC). The heat exchangers in the main cooling system are required the heat exchange performance to remove the reactor-generated-heat of 30MW under the condition of reactor coolant outlet temperature of 850degC/950degC. Therefore, the heat exchanges are required to satisfy the design criteria of heat exchange performance. In this report, heat exchange performance of the SPWC in the main cooling system was evaluated with the rise-to-power-up test and the in-service operation data. Moreover, evaluated value is compared with designed one, it is confirmed that the SPWC has required heat exchange performance. (author)

  1. System design package for the solar heating and cooling central data processing system

    Science.gov (United States)

    1978-01-01

    The central data processing system provides the resources required to assess the performance of solar heating and cooling systems installed at remote sites. These sites consist of residential, commercial, government, and educational types of buildings, and the solar heating and cooling systems can be hot-water, space heating, cooling, and combinations of these. The instrumentation data associated with these systems will vary according to the application and must be collected, processed, and presented in a form which supports continuity of performance evaluation across all applications. Overall software system requirements were established for use in the central integration facility which transforms raw data collected at remote sites into performance evaluation information for assessing the performance of solar heating and cooling systems.

  2. 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.

  3. Development and application of a specially designed heating system for temperature-programmed high-performance liquid chromatography using subcritical water as the mobile phase.

    Science.gov (United States)

    Teutenberg, T; Goetze, H-J; Tuerk, J; Ploeger, J; Kiffmeyer, T K; Schmidt, K G; Kohorst, W gr; Rohe, T; Jansen, H-D; Weber, H

    2006-05-05

    A specially designed heating system for temperature-programmed HPLC was developed based on experimental measurements of eluent temperature inside a stainless steel capillary using a very thin thermocouple. The heating system can be operated at temperatures up to 225 degrees C and consists of a preheating, a column heating and a cooling unit. Fast cycle times after a temperature gradient can be realized by an internal silicone oil bath which cools down the preheating and column heating unit. Long-term thermal stability of a polybutadiene-coated zirconium dioxide column has been evaluated using a tubular oven in which the column was placed. The packing material was stable after 50h of operation at 185 degrees C. A mixture containing four steroids was separated at ambient conditions using a mobile phase of 25% acetonitrile:75% deionized water and a mobile phase of pure deionized water at 185 degrees C using the specially designed heating system and the PBD column. Analysis time could be drastically reduced from 17 min at ambient conditions and a flow rate of 1 mL/min to only 1.2 min at 185 degrees C and a flow rate of 5 mL/min. At these extreme conditions, no thermal mismatch was observed and peaks were not distorted, thus underlining the performance of the developed heating system. Temperature programming was performed by separating cytostatic and antibiotic drugs with a temperature gradient using only water as the mobile phase. In contrast to an isocratic elution of this mixture at room temperature, overall analysis time could be reduced two-fold from 20 to 10 min.

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

    International Nuclear Information System (INIS)

    Kaynakli, Omer; Saka, Kenan; Kaynakli, Faruk

    2015-01-01

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

  5. A water heating system analysis for rural residences, using solar energy; Analise de um sistema de aquecimento de agua para residencias rurais, utilizando energia solar

    Energy Technology Data Exchange (ETDEWEB)

    Basso, Luiz H.; Souza, Samuel N.M. de; Siqueira, Jair A.C.; Nogueira, Carlos E.C.; Santos, Reginaldo F. [Universidade Estadual do Oeste do Parana (UNIOESTE), Cascavel, PR (Brazil). Programa de Pos-Graduacao em Engenharia Agricola], emails: melegsouza@yahoo.com, ssouza@unioeste.br, jairsiqueira@unioeste.br, cecn1@yahoo.com.br, rfsantos@unioeste.br

    2010-01-15

    The awareness of the importance of the environment has stimulated the study of new renewed energy sources and less pollutant. Amongst these sources, solar energy stands alone for being perennial and clean. The use of solar energy in systems of agricultural residential water heating, can complement the economy of electric energy, base of the Brazilian energy matrix. Knowing the factors that influence the operation of a system of water heating by solar energy is important in determining their technical viabilities targeting their distribution in agricultural residences. To evaluate equipment of water heating for solar energy, a prototype was constructed in the campus of Assis Gurgacz College, in Cascavel,State of Parana, Brazil, with similar characteristics to equipment used in residences for two inhabitants, to function with natural circulation or thermo siphon and without help of a complementary heating system. The equipment revealed technical viability, reaching the minimum temperature for shower, of 35 deg C, whenever the solar radiation was above the 3,500 Wh m{sup -2}, for the majority of the studied days. (author)

  6. Design and experimental study of a solar system for heating water ...

    African Journals Online (AJOL)

    This work presents a design and an experimental study of a linear Fresnel reflector solar with trapezoidal cavity. This prototype is used for heating the tap water. The reflector was designed, constructed and tested in mechanical engineering department, University of Blida 1, Algeria. Various combinations of reflecting mirrors ...

  7. The embodiment design of the heat rejection system for the portable life support system

    Science.gov (United States)

    Stuckwisch, Sue; Francois, Jason; Laughlin, Julia; Phillips, Lee; Carrion, Carlos A.

    1994-01-01

    The Portable Life Support System (PLSS) provides a suitable environment for the astronaut in the Extravehicular Mobility Unit (EMU), and the heat rejection system controls the thermal conditions in the space suit. The current PLSS sublimates water to the space environment; therefore, the system loses mass. Since additional supplies of fluid must be available on the Space Shuttle, NASA desires a closed heat rejecting system. This document presents the embodiment design for a radiative plate heat rejection system without mass transfer to the space environment. This project will transform the concept variant into a design complete with material selection, dimensions of the system, layouts of the heat rejection system, suggestions for manufacturing, and financial viability.

  8. Automation of heating system with heat pump

    OpenAIRE

    Ferdin, Gašper

    2016-01-01

    Because of high prices of energy, we are upgrading our heating systems with newer, more fuel efficient heating devices. Each new device has its own control system, which operates independently from other devices in a heating system. With a relatively low investment costs in automation, we can group devices in one central control system and increase the energy efficiency of a heating system. In this project, we show how to connect an oil furnace, a sanitary heat pump, solar panels and a heat p...

  9. The scientific base of heating water by microwave

    Energy Technology Data Exchange (ETDEWEB)

    Akdoğan, Ender, E-mail: ender.akdogan@tpe.gov.tr [Department of Physics Engineering, Ankara University, Dögol St. Tandoğan Ankara 06560 Türkiye (Turkey); Çiftçi, Muharrem, E-mail: muharrem-ciftci@windowslive.com [Author" 1 Department of Physics, Ankara University, Dögol St. Tandoğan Ankara 06560 Türkiye (Turkey)

    2016-03-25

    This article is based on the master thesis [4] related to our invention which was published in World Intellectual Property Organization (WO/2011/048506) as a microwave water heater. In the project, a prototype was produced to use microwave in industrial heating. In order to produce the prototype, the most appropriate material kind for microwave-water experiments was determined by a new energy loss rate calculation technique. This new energy loss calculation is a determinative factor for material permeability at microwave frequency band (1-100 GHz). This experimental series aim to investigate the rationality of using microwave in heating industry. Theoretically, heating water by microwave (with steady frequency 2.45 GHz) is analyzed from sub-molecular to Classical Mechanic results of heating. In the study, we examined Quantum Mechanical base of heating water by microwave experiments. As a result, we derived a Semi-Quantum Mechanical equation for microwave-water interactions and thus, Wien displacement law can be derived to verify experimental observations by this equation.

  10. Recycling technologies for sewarage systems. Reuse of water, heat, and sludge in Tokyo; Gesuido wo meguru risaikuru gijutsu. Tokyoto ni okeru mizu/netsu/odei no sairiyo

    Energy Technology Data Exchange (ETDEWEB)

    Mino, T. [Tokyo Univ. (Japan)

    1996-03-10

    The recycling technology employed in Tokyo were reported. It will be useful for developing and introducing the recycling technology for water, heat, and sludge in the sewage treatment. Among various kinds of recycling technology, one of the most peculiar technology is the district heating and cooling system using the heat of sewage. The Japan`s first practical plant which uses the untreated sewage as the heat source was installed and is now operating in Korakuen pump station. In the station, the energy contained in the sewage is recovered by a heat exchanger. The heat pump produces warm water of 45{degree}C and cold water of 7{degree}C as well. Both are supplied to the area near by through the heat source supply pipeline. The Nanbu sludge plant has a sludge-resourcing plant, in which the sludge is converted into fuel, metro-bricks, and light-weight granules, as well as a conventional sludge treatment plant carrying out the concentration, dehydration, and incineration of sludge. The Ochiai sewage treatment plant reuses water after cleaning. The clean water is used as for the service water in addition to being discharged into the river stream. 7 figs., 1 tab.

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

    Directory of Open Access Journals (Sweden)

    B. A. Bayrashevsky

    2009-01-01

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

  12. Performance of a Heating Block System Designed for Studying the Heat Resistance of Bacteria in Foods

    Science.gov (United States)

    Kou, Xiao-xi; Li, Rui; Hou, Li-xia; Huang, Zhi; Ling, Bo; Wang, Shao-jin

    2016-01-01

    Knowledge of bacteria’s heat resistance is essential for developing effective thermal treatments. Choosing an appropriate test method is important to accurately determine bacteria’s heat resistances. Although being a major factor to influence the thermo-tolerance of bacteria, the heating rate in samples cannot be controlled in water or oil bath methods due to main dependence on sample’s thermal properties. A heating block system (HBS) was designed to regulate the heating rates in liquid, semi-solid and solid foods using a temperature controller. Distilled water, apple juice, mashed potato, almond powder and beef were selected to evaluate the HBS’s performance by experiment and computer simulation. The results showed that the heating rates of 1, 5 and 10 °C/min with final set-point temperatures and holding times could be easily and precisely achieved in five selected food materials. A good agreement in sample central temperature profiles was obtained under various heating rates between experiment and simulation. The experimental and simulated results showed that the HBS could provide a sufficiently uniform heating environment in food samples. The effect of heating rate on bacterial thermal resistance was evaluated with the HBS. The system may hold potential applications for rapid and accurate assessments of bacteria’s thermo-tolerances. PMID:27465120

  13. A passive decay heat removal system for LWRs based on air cooling

    Energy Technology Data Exchange (ETDEWEB)

    Mochizuki, Hiroyasu, E-mail: mochizki@u-fukui.ac.jp [Research Institute of Nuclear Engineering, University of Fukui, 1-2-4 Kanawa-cho, Tsuruga, Fukui 914-0055 (Japan); Yano, Takahiro [Graduate School of Engineering, University of Fukui, 1-2-4 Kanawa-cho, Tsuruga, Fukui 914-0055 (Japan)

    2015-05-15

    Highlights: • A passive decay heat removal system for LWRs is discussed. • An air cooler model which condenses steam is developed. • The decay heat can be removed by air coolers with forced convection. • The dimensions of the air cooler are proposed. - Abstract: The present paper describes the capability of an air cooling system (ACS) to remove decay heat from a core of LWR such as an advanced boiling water reactor (ABWR) and a pressurized water reactor (PWR). The motivation of the present research is the Fukushima severe accident (SA) on 11 March 2011. Since emergency cooling systems using electricity were not available due to station blackout (SBO) and malfunctions, many engineers might understand that water cooling was not completely reliable. Therefore, a passive decay heat removal (DHR) system would be proposed in order to prevent such an SA under the conditions of an SBO event. The plant behaviors during the SBO are calculated using the system code NETFLOW++ for the ABWR and PWR with the ACS. Two types of air coolers (ACs) are applied for the ABWR, i.e., a steam condensing air cooler (SCAC) of which intake for heat transfer tubes is provided in the steam region, and single-phase type of which intake is provided in the water region. The DHR characteristics are calculated under the conditions of the forced air circulation and also the natural air convection. As a result of the calculations, the decay heat can be removed safely by the reasonably sized ACS when heat transfer tubes are cooled with the forced air circulation. The heat removal rate per one finned heat transfer tube is evaluated as a function of air flow rate. The heat removal rate increases as a function of the air flow rate.

  14. Thermophysical Properties of Fluid Latent Heat Storage Material using Urea-Water Mixture

    Science.gov (United States)

    Hokamura, Taku; Ohkubo, Hidetoshi; Ashizawa, Kiyonori

    This study is concerned with the measurement of thermophysical properties of a urea-water mixture with the aim of adopting the mixture as a latent heat storage material for air-conditioning systems. The urea-water mixture is made of natural substances and has a good fluidity. The urea concentration in the mixture was controlled by measuring the refractive index of the mixture. Being a multi-component substance, a urea-water solution has a liquid-solid co-existent phase on a phase-diagram. Therefore, the liquidus temperature was measured to establish a relationship between the fraction of the solid-phase and temperature. Furthermore, apparent values of specific heat and coefficient of viscosity were measured in the two-phase region where the solid phase is ice. The apparent specific heat and coefficient of viscosity were measure by using an adiabatic calorimeter and a stirring torque meter respectively. The results revealed that the urea-water mixture can probably be used as a latent heat storage material of good fluidity.

  15. Potential for solar water heating in Zimbabwe

    NARCIS (Netherlands)

    Batidzirai, B.; Lysen, E.H.; van Egmond, S.; van Sark, W.G.J.H.M.

    2009-01-01

    This paper discusses the economic, social and environmental benefits from using solar water heating (SWH) in Zimbabwe. By comparing different water heating technology usage in three sectors over a 25-year period, the potential of SWH is demonstrated in alleviating energy and economic problems that

  16. FY1999 Meeting of The Society of Heating, Air-Conditioning and Sanitary Engineering of Japan. Hot water supply system; 1999 nendo gakujutsu koenkai gaiyo. Kyuto

    Energy Technology Data Exchange (ETDEWEB)

    Oze, H. [Toyo University, Tokyo (Japan)

    1999-12-05

    G-5 and 6 measure and investigate actual state of use of hot water supply systems in dormitories used by persons living alone without their families and by unmarried persons to collect fundamental data. G-5 considers how hot water is used, by making a questionnaire survey on the subject houses, and identifies the consumption trend of heat, water and hot water in the hot water supply systems as a whole. G-6 selected eleven houses from among the houses discussed in the previous report to identify the trend of use of hot water by each house. Also, quantity of hot water used in every day of the week is estimated. G-7 discusses methods for estimating water temperatures at faucets of water pipes from the water sources. This is intended to raise the accuracy of tap water temperature conversion coefficient by districts used for calculating estimated heat quantity as a parameter 'hot water supply energy consumption coefficient' to evaluate energy saving performance of a hot water supply facility. G-8 performs numerical simulations changing different parameters in the hot water supply piping system by using a heat loss calculation model for the existing household hot water supply piping. It executes evaluation on energy conservation performance of each model. G-9 estimates efficiency of instantaneous household gas hot water supply devices, not only on thermal efficiency of devices during steady state combustion, but also on non-steady state such as start-up, and discusses methods to derive actual efficiency by using calculations. (translated by NEDO)

  17. Heating systems for heating subsurface formations

    Science.gov (United States)

    Nguyen, Scott Vinh [Houston, TX; Vinegar, Harold J [Bellaire, TX

    2011-04-26

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

  18. Water conservation and improved production efficiency using closed-loop evaporative cooling systems

    Energy Technology Data Exchange (ETDEWEB)

    Marchetta, C. [Niagara Blower Co., Buffalo, NY (United States)

    2009-07-01

    This paper described wet surface air coolers (WSAC) that can be used in refineries and hydrocarbon processing plants to address water use issues. These closed-loop evaporative cooling systems are a cost-effective technology for both heat transfer and water conservation. WSACs can help deliver required cooling water temperatures and improve plant performance while using water streams currently considered to be unusable with conventional towers and heat exchangers. WSACs are versatile and can provide solutions to water use, water quality, and outlet temperature. The benefits of the WSAC include capital cost savings, reduced system pressures, lower carbon footprint, and the ability to use poor quality water as makeup. Water makeup can be blowdown from other equipment, plant effluent, reclaimed water, produced water, flue gas desulphurization (FGD) wastewater, and even seawater. Units can be manufactured with a wide variety of materials depending on water quality, water treatment, and cycles of concentration. This paper also provided comparisons to other alternative technologies, capital and operating cost savings, and site specific case studies. Two other system designs can accommodate closed-loop heat transfer applications, notably an open tower with a heat exchanger and a dry, air-cooled system. A WSAC system is an efficient and effective heat rejection technology for several reasons. The WSAC cooler or condenser utilizes latent cooling, which is far more efficient than sensible cooling. This means that a WSAC system can cool the same heat load with a smaller footprint than all-dry systems. 6 figs.

  19. Analysis and comparison of methods for the preparation of domestic hot water from district heating system, selected renewable and non-renewable sources in low-energy buildings

    Directory of Open Access Journals (Sweden)

    Knapik Maciej

    2018-01-01

    Full Text Available The article presents an economic analysis and comparison of selected (district heating, natural gas, heat pump with renewable energy sources methods for the preparation of domestic hot water in a building with low energy demand. In buildings of this type increased demand of energy for domestic hot water preparation in relation to the total energy demand can be observed. As a result, the proposed solutions allow to further lower energy demand by using the renewable energy sources. This article presents the results of numerical analysis and calculations performed mainly in MATLAB software, based on typical meteorological years. The results showed that system with heat pump and renewable energy sources Is comparable with district heating system.

  20. Analysis and comparison of methods for the preparation of domestic hot water from district heating system, selected renewable and non-renewable sources in low-energy buildings

    Science.gov (United States)

    Knapik, Maciej

    2018-02-01

    The article presents an economic analysis and comparison of selected (district heating, natural gas, heat pump with renewable energy sources) methods for the preparation of domestic hot water in a building with low energy demand. In buildings of this type increased demand of energy for domestic hot water preparation in relation to the total energy demand can be observed. As a result, the proposed solutions allow to further lower energy demand by using the renewable energy sources. This article presents the results of numerical analysis and calculations performed mainly in MATLAB software, based on typical meteorological years. The results showed that system with heat pump and renewable energy sources Is comparable with district heating system.

  1. Component Cooling Heat Exchanger Heat Transfer Capability Operability Monitoring

    International Nuclear Information System (INIS)

    Mihalina, M.; Djetelic, N.

    2010-01-01

    The ultimate heat sink (UHS) is of highest importance for nuclear power plant safe and reliable operation. The most important component in line from safety-related heat sources to the ultimate heat sink water body is a component cooling heat exchanger (CC Heat Exchanger). The Component Cooling Heat Exchanger has a safety-related function to transfer the heat from the Component Cooling (CC) water system to the Service Water (SW) system. SW systems throughout the world have been the root of many plant problems because the water source, usually river, lake, sea or cooling pond, are conductive to corrosion, erosion, biofouling, debris intrusion, silt, sediment deposits, etc. At Krsko NPP, these problems usually cumulate in the summer period from July to August, with higher Sava River (service water system) temperatures. Therefore it was necessary to continuously evaluate the CC Heat Exchanger operation and confirm that the system would perform its intended function in accordance with the plant's design basis, given as a minimum heat transfer rate in the heat exchanger design specification sheet. The Essential Service Water system at Krsko NPP is an open cycle cooling system which transfers heat from safety and non-safety-related systems and components to the ultimate heat sink the Sava River. The system is continuously in operation in all modes of plant operation, including plant shutdown and refueling. However, due to the Sava River impurities and our limited abilities of the water treatment, the system is subject to fouling, sedimentation buildup, corrosion and scale formation, which could negatively impact its performance being unable to satisfy its safety related post accident heat removal function. Low temperature difference and high fluid flows make it difficult to evaluate the CC Heat Exchanger due to its specific design. The important effects noted are measurement uncertainties, nonspecific construction, high heat transfer capacity, and operational specifics (e

  2. Advanced Supermarket Refrigeration/Heat Recovery Systems. Country Report, Denmark

    DEFF Research Database (Denmark)

    Knudsen, Hans-Jørgen Høgaard; Christensen, K. G.

    Annex 26 is the first international project under the IEA Heat Pump Programme that links refrigeration and heat pump technology. Recovering heat from advanced supermarket refrigeration systems for space and water heating seems obvious and is beneficial for owners and operators. Because the great...... number of supermarkets that offer frozen and chilled food and further growth of this sector may be expected, the amount of energy used for refrigeration is enormous and will likely increase in the near future. Annex 26 analysed several advanced supermarket refrigeration systems and came to remarkable...... conclusions as far energy conservation and TEWI reduction is concerned. The conclusion justify that advanced supermarket systems with heat recovery should receive great attention and support. And there is still further research needed in several areas. The Annex also included a thorough system analyses...

  3. A study on post impingement effects of urea-water solution spray on the heated wall of automotive SCR systems

    Science.gov (United States)

    Shahariar, G. M. H.; Wardana, M. K. A.; Lim, O. T.

    2018-04-01

    The post impingement effects of urea-water solution spray on the heated wall of automotive SCR systems was numerically investigated in a constant volume chamber using STAR CCM+ CFD code. The turbulence flow was modelled by realizable k-ε two-layer model together with standard wall function and all y+ treatment was applied along with two-layer approach. The Eulerian-Lagrangian approach was used for the modelling of multi phase flow. Urea water solution (UWS) was injected onto the heated wall for the wall temperature of 338, 413, 473, 503 & 573 K. Spray development after impinging on the heated wall was visualized and measured. Droplet size distribution and droplet evaporation rates were also measured, which are vital parameters for the system performance but still not well researched. Specially developed user defined functions (UDF) are implemented to simulate the desired conditions and parameters. The investigation reveals that wall temperature has a great impact on spray development after impingement, droplet size distribution and evaporation. Increasing the wall temperature leads to longer spray front projection length, smaller droplet size and faster droplet evaporation which are preconditions for urea crystallization reduction. The numerical model and parameters are validated comparing with experimental data.

  4. Indirect Solar Water Heating in Single-Family, Zero Energy Ready Homes

    Energy Technology Data Exchange (ETDEWEB)

    Aldrich, Robb [Consortium for Advanced Residential Buildings, Norwalk, CT (United States)

    2016-02-17

    Solar water heating systems are not new, but they have not become prevalent in most of the U.S. Most of the country is cold enough that indirect solar thermal systems are required for freeze protection, and average installed cost of these systems is $9,000 to $10,000 for typical systems on single-family homes. These costs can vary significantly in different markets and with different contractors, and federal and regional incentives can reduce these up-front costs by 50% or more. In western Massachusetts, an affordable housing developer built a community of 20 homes with a goal of approaching zero net energy consumption. In addition to excellent thermal envelopes and PV systems, the developer installed a solar domestic water heating system (SDHW) on each home. The Consortium for Advanced Residential Buildings (CARB), a research consortium funded by the U.S. Department of Energy Building America program, commissioned some of the systems, and CARB was able to monitor detailed performance of one system for 28 months.

  5. A thermal sensor for water using self-heated NTC thick-film segmented thermistors

    OpenAIRE

    Nikolić, Maria Vesna; Radojčić, B. M.; Aleksić, Obrad; Luković, Miloljub D.; Nikolić, Pantelija

    2011-01-01

    A simple thermal (heat loss) sensor system was designed in a small plastic tube housing using a negative thermal coefficient (NTC) thick-film thermistor as a self-heating sensor. The voltage power supply [range constant voltage (RCV)-range constant voltage] uses the measured input water temperature to select the applied voltage in steps (up and down) in order to enable operation of the sensor at optimal sensitivity for different water temperatures. The input water temperature was measured usi...

  6. Exergy analysis of single effect absorption refrigeration systems: The heat exchange aspect

    International Nuclear Information System (INIS)

    Joybari, Mahmood Mastani; Haghighat, Fariborz

    2016-01-01

    Highlights: • Exergy analysis of LiBr/H 2 O absorption systems with identical COP was carried out. • Exergy destruction rank: absorber followed by generator, condenser and evaporator. • Lower heat source and chilled water inlet temperature reduced exergy destruction. • Higher cooling water inlet temperature reduced exergy destruction. • Lower HTF mass flow rate increased exergy efficiency even for fixed system COP. - Abstract: The main limitation of conventional energy analysis for the thermal performance of energy systems is that this approach does not consider the quality of energy. On the other hand, exergy analysis not only provides information about the systems performance, but also it can specify the locations and magnitudes of losses. A number of studies investigated the effect of parameters such as the component temperature, and heat transfer fluid (HTF) temperature and mass flow rate on the exergetic performance of the same absorption refrigeration system; thus, reported different coefficient of performance (COP) values. However, in this study, the system COP was considered to remain constant during the investigation. This means comparing systems with different heat exchanger designs (based on HTF mass flow rate and temperature) having the same COP value. The effect of HTF mass flow rate and inlet temperature of the cooling water, chilled water and heat source on the outlet specific exergy and exergy destruction rate of each component was investigated. It was found that the lower HTF mass flow rate decreased exergy destruction of the corresponding component. Moreover, the lower temperature of heat source and chilled water inlet increased the system exergetic efficiency. That was also the case for the higher cooling water inlet temperature. Based on the analysis, since the absorber and condenser accounted for a large portion of the total exergy destruction, cooling tower modification with lower cooling water mass flow rate is recommended

  7. Solar heating and cooling of residential buildings: design of systems, 1980 edition

    Energy Technology Data Exchange (ETDEWEB)

    None

    1980-09-01

    This manual was prepared primarily for use in conducting a practical training course on the design of solar heating and cooling systems for residential and small office buildings, but may also be useful as a general reference text. The content level is appropriate for persons with different and varied backgrounds, although it is assumed that readers possess a basic understanding of heating, ventilating, and air-conditioning systems of conventional (non-solar) types. This edition is a revision of the manual with the same title, first printed and distributed by the US Government Printing Office in October 1977. The manual has been reorganized, new material has been added, and outdated information has been deleted. Only active solar systems are described. Liquid and air-heating solar systems for combined space and service water heating or service water heating are included. Furthermore, only systems with proven experience are discussed to any extent.

  8. Prediction of critical heat flux for water in uniformly heated vertical ...

    African Journals Online (AJOL)

    Keywords: CHF - Heat transfer - Water vapor - Porous coated tubes. Auteur correspondant ... electrical and mechanical characteristics were well validated. Figure. 1 shows ... resistance to vapor filtration from the heating wall to the liquid bulk.

  9. Solar heating of the produced water of petroleum; Aquecimento solar da agua produzida de petroleo

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Rogerio Pitanga; Chiavone-Filho, Osvaldo; Bezerra, Magna A. Santos; Melo, Josette Lourdes Sousa de; Oliveira, Jackson Araujo de; Ramos, Rafael E. Moura [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil); Schuhli, Juliana Bregenski; Andrade, Vivian Tavares de [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil). Centro de Pesquisas (CENPES)

    2008-07-01

    In this work, experimental data of solar heating for common water and saline solution were measured. The solar heater is formed by a flat-plane collector and a thermal reservoir ('boiler'). The objective is to quantify the variation of fluids' temperature, and correlate it to environment variables, especially solar irradiation. Thereby, it is possible to estimate the solar heating of produced water of petroleum. The solar heater is part of a system of treatment of produced water, and its function is to pre-heat the fluid that enters into the solar distiller, increasing the productivity of distilled water. A saline solution that represents produced water was used in the experiments, using sodium chloride (1000 ppm). The experimental data demonstrates that the solar heater is capable to heat the fluid to temperatures close to 70 deg C, reaching temperatures close to 50 deg C even during cloudy days with low solar radiation. Furthermore, the solar collector energy system provides a higher rate of heating and trough of the thermal reservoir the temperature can remain longer. These are important aspects to the integration with solar distillation. (author)

  10. Solar heating of the produced water of petroleum; Aquecimento solar da agua produzida de petroleo

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Rogerio Pitanga; Chiavone-Filho, Osvaldo; Bezerra, Magna A. Santos; Melo, Josette Lourdes Sousa de; Oliveira, Jackson Araujo de; Ramos, Rafael E. Moura [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil); Schuhli, Juliana Bregenski; Andrade, Vivian Tavares de [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil). Centro de Pesquisas (CENPES)

    2008-07-01

    In this work, experimental data of solar heating for common water and saline solution were measured. The solar heater is formed by a flat-plane collector and a thermal reservoir ('boiler'). The objective is to quantify the variation of fluids' temperature, and correlate it to environment variables, especially solar irradiation. Thereby, it is possible to estimate the solar heating of produced water of petroleum. The solar heater is part of a system of treatment of produced water, and its function is to pre-heat the fluid that enters into the solar distiller, increasing the productivity of distilled water. A saline solution that represents produced water was used in the experiments, using sodium chloride (1000 ppm). The experimental data demonstrates that the solar heater is capable to heat the fluid to temperatures close to 70 deg C, reaching temperatures close to 50 deg C even during cloudy days with low solar radiation. Furthermore, the solar collector energy system provides a higher rate of heating and trough of the thermal reservoir the temperature can remain longer. These are important aspects to the integration with solar distillation. (author)

  11. Mushroom drying with solar assisted heat pump system

    International Nuclear Information System (INIS)

    Şevik, Seyfi; Aktaş, Mustafa; Doğan, Hikmet; Koçak, Saim

    2013-01-01

    Highlights: • Experimental investigation of a simple and cost effective solar assisted heat pump system. • Developing of a computer program for a drying system with different scenarios by using PLC. • Obtained less energy input with high coefficients of performance of system and more quality products. • Determination of mushroom drying properties such as moisture content, moisture ratio and drying ratio. - Abstract: In this study, a simple and cost effective solar assisted heat pump system (SAHP) with flat plate collectors and a water source heat pump has been proposed. Mushroom drying was examined experimentally in the drying system. Solar energy (SE) system and heat pump (HP) system can be used separately or together. A computer program has been developed for the system. Drying air temperature, relative humidity, weight of product values, etc. were monitored and controlled with different scenarios by using PLC. This system is cheap, good quality and sustainable and it is modeled for good quality product and increased efficiency. Thus, products could be dried with less energy input and more controlled conditions. Mushrooms were dried at 45 °C and 55 °C drying air temperature and 310 kg/h mass flow rate. Mushrooms were dried from initial moisture content 13.24 g water/g dry matter (dry basis) to final moisture content 0.07 g water/g dry matter (dry basis). Mushrooms were dried by using HP system, SE system and SAHP system respectively at 250–220 min, at 270–165 min and at 230–190 min. The coefficients of performance of system (COP) are calculated in a range from 2.1 to 3.1 with respect to the results of experiments. The energy utilization ratios (EURs) were found to vary between 0.42 and 0.66. Specific moisture extraction rate (SMER) values were found to vary between 0.26 and 0.92 kg/kW h

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

    International Nuclear Information System (INIS)

    Deng, Weishi; Yu, Jianlin

    2016-01-01

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

  13. Fiscal 1976 Sunshine Project result report. R and D on solar cooling/heating and hot water supply system (R and D on the system for apartment houses); 1976 nendo taiyo reidanbo oyobi kyuto system no kenkyu kaihatsu seika hokokusho. Shugo jutakuyo system no kenkyu kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1977-03-01

    This report describes the fiscal 1976 research result on solar cooling/heating and hot water supply system for apartment houses. In the system research, comparative study was made on facility costs and operation costs per heat load between previous and solar cooling/heating and hot water supply systems for apartment houses. In the working design for apartment houses, various calculation necessary for start of work, and preparation of detail drawings and specifications were made. In development of solar collector, the test loop and collector were prepared using full-scale collector elements for medium-scale performance tests. In development of heat accumulator, inorganic hydrate was selected as heat storage material using latent heat for the confirmation test of basic physical properties. In development of solar cooling/heating equipment, the confirmation test of Rankine engine's performance, controllability and durability was made under real load. In addition, the refrigerator of nearly 20 tons of refrigeration driven by Rankine engine was fabricated, (NEDO)

  14. Thermal Performance of a Large Low Flow Solar Heating System with a Highly Thermally Stratified Tank

    DEFF Research Database (Denmark)

    Furbo, Simon; Vejen, Niels Kristian; Shah, Louise Jivan

    2005-01-01

    are facing west. The collector tilt is 15° from horizontal for all collectors. Both the east-facing and the west-facing collectors have their own solar collector loop, circulation pump, external heat exchanger and control system. The external heat exchangers are used to transfer the heat from the solar......In year 2000 a 336 m² solar domestic hot water system was built in Sundparken, Elsinore, Denmark. The solar heating system is a low flow system with a 10000 l hot-water tank. Due to the orientation of the buildings half of the solar collectors are facing east, half of the solar collectors...... collector fluid to the domestic water. The domestic water is pumped from the bottom of the hot-water tank to the heat exchanger and back to the hot-water tank through stratification inlet pipes. The return flow from the DHW circulation pipe also enters the tank through stratification inlet pipes. The tank...

  15. Building integration of concentrating solar systems for heating applications

    International Nuclear Information System (INIS)

    Tsoutsou, Sapfo; Infante Ferreira, Carlos; Krieg, Jan; Ezzahiri, Mohamed

    2014-01-01

    A new solar collection system integrated on the façade of a building is investigated for Dutch climate conditions. The solar collection system includes a solar façade, a receiver tube and 10 Fresnel lenses. The Fresnel lenses Fresnel lenses considered were linear, non-imaging, line – focused with a system tracking the position of the sun that ensures vertical incidence of the direct solar radiation on the lenses. For the heating system a double-effect absorption heat pump, which requires high temperature of the heating fluid, was used, working with water and lithium-bromide as refrigerant and solution respectively. The Fresnel lens system is connected with the absorption heat pump through a thermal energy storage tank which accumulates the heat from the Fresnel lens system to provide it to the high pressure generator of the absorption heat pump. - Highlights: • The integration of Fresnel lenses in solar thermal building façades is investigated. • Using building integrated Fresnel lenses, 43% heating energy can be saved. • Energy savings in Mediterranean countries are significantly larger. • The absorption heat pump could make great contribution to energy savings for Dutch climate conditions

  16. Using containment analysis to improve component cooling water heat exchanger limits

    International Nuclear Information System (INIS)

    Da Silva, H.C.; Tajbakhsh, A.

    1995-01-01

    The Comanche Peak Steam Electric Station design requires that exit temperatures from the Component Cooling Water Heat Exchanger remain below 330.37 K during the Emergency Core Cooling System recirculation stage, following a hypothetical Loss of Coolant Accident (LOCA). Due to measurements indicating a higher than expected combination of: (a) high fouling factor in the Component Cooling Water Heat Exchanger with (b) high ultimate heat sink temperatures, that might lead to temperatures in excess of the 330.37 K limit, if a LOCA were to occur, TUElectric adjusted key flow rates in the Component Cooling Water network. This solution could only be implemented with improvements to the containment analysis methodology of record. The new method builds upon the CONTEMPT-LT/028 code by: (a) coupling the long term post-LOCA thermohydraulics with a more detailed analytical model for the complex Component Cooling Water Heat Exchanger network and (b) changing the way mass and energy releases are calculated after core reflood and steam generator energy is dumped to the containment. In addition, a simple code to calculate normal cooldowns was developed to confirm RHR design bases were met with the improved limits

  17. Reports on 1979 result of Sunshine Project. R and D on solar cooling/heating and hot-water supply system (R and D on system for multiple dwelling); 1979 nendo taiyo reidanbo oyobi kyuto system no kenkyu kaihatsu seika hokokusho. Shugo jutakuyo system no kenkyu kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1980-03-01

    This R and D was intended to develop the following technologies for the purpose of putting into practice an innovative system that performs cooling/heating and hot-water supply for a multiple dwelling economically by solar energy: development of equipment constituting solar cooling/heating and hot-water supply system, and development of a system which uses such equipment and which is inexpensive and safe as well as easy for inspection and maintenance. In fiscal 1979, a study was implemented in which emphasis was placed on the experiment of a test housing with a solar cooling/heating and hot-water supply system incorporated for the purpose of proving the results of the research since fiscal 1974. In the overall flow of this project, the following research contents were partially performed or being performed successively during the period of seven years. (1) Examination of various methods, (2) Development of thermally driven freezer, (3) High performance heat collecter, (4) Heat storage device, (5) Types of multiple dwelling suitable for solar energy utilization, (6) Construction of experimental multiple dwelling, (7) Experiment in houses actually in use by people, (8) Confirmation of system improvements and results on the basis of experimental measurements, and (9) Evaluation as a solar system for multiple dwelling. (NEDO)

  18. District heating and heat storage using the solution heat of an ammonia/water system

    International Nuclear Information System (INIS)

    Taube, M.; Peier, W.; Mayor, J.C.

    1976-01-01

    The article describes a model for the optimum use of the heat energy generated in a nuclear power station for district heating and heat storage taking account of the electricity and heat demand varying with time. (HR/AK) [de

  19. Influence of radiative heat and mass transfer mechanism in systemwater droplet-high-temperature gases” on integral characteristics of liquid evaporation

    Directory of Open Access Journals (Sweden)

    Glushkov Dmitrii O.

    2015-01-01

    Full Text Available Physical and mathematical (system of differential equations in private derivatives models of heat and mass transfer were developed to investigate the evaporation processes of water droplets and emulsions on its base moving in high-temperature (more than 1000 K gas flow. The model takes into account a conductive and radiative heat transfer in water droplet and also a convective, conductive and radiative heat exchange with high-temperature gas area. Water vapors characteristic temperature and concentration in small wall-adjacent area and trace of the droplet, numerical values of evaporation velocities at different surface temperature, the characteristic time of complete droplet evaporation were determined. Experiments for confidence estimation of calculated integral characteristics of processes under investigation - mass liquid evaporation velocities were conducted with use of cross-correlation recording video equipment. Their satisfactory fit (deviations of experimental and theoretical velocities were less than 15% was obtained. The influence of radiative heat and mass transfer mechanism on characteristics of endothermal phase transformations in a wide temperature variation range was established by comparison of obtained results of numerical simulation with known theoretical data for “diffusion” mechanisms of water droplets and other liquids evaporation in gas.

  20. Optimization of Temperature Schedule Parameters on Heat Supply in Power-and-Heat Supply Systems

    Directory of Open Access Journals (Sweden)

    V. A. Sednin

    2009-01-01

    Full Text Available The paper considers problems concerning optimization of a temperature schedule in the district heating systems with steam-turbine thermal power stations having average initial steam parameters. It has been shown in the paper that upkeeping of an optimum network water temperature permits to increase an energy efficiency of heat supply due to additional systematic saving of fuel. 

  1. Integrated solar-assisted heat pumps for water heating coupled to gas burners; control criteria for dynamic operation

    International Nuclear Information System (INIS)

    Scarpa, F.; Tagliafico, L.A.; Tagliafico, G.

    2011-01-01

    A direct expansion integrated solar-assisted heat pump (ISAHP) is compared to a traditional flat plate solar panel for low temperature (45 deg. C) water heating applications. The (simulated) comparison is accomplished assuming both the devices are energy supplemented with an auxiliary standard gas burner, to provide the typical heat duty of a four-member family. Literature dynamical models of the systems involved have been used to calculate the main performance figures in a context of actual climatic conditions and typical stochastic user demand. The paper highlights new heat pump control concepts, needed when maximum energy savings are the main goal of the apparatus for given user demand. Simulations confirm the high collector efficiency of the ISAHP when its panel/evaporator works at temperature close to the ambient one. The device, with respect to a flat plate solar water heater, shows a doubled performance, so that it can do the same task just using an unglazed panel with roughly half of the surface.

  2. Heat Transfer Phenomena in Supercritical Water Nuclear Reactors

    International Nuclear Information System (INIS)

    Mark H. Anderson; MichaelL. Corradini; Riccardo Bonazza; Jeremy R. Licht

    2007-01-01

    A supercritical water heat transfer facility has been built at the University of Wisconsin to study heat transfer in a circular and square annular flow channel. A series of integral heat transfer measurements has been carried out over a wide range of heat flux, mass velocity and bulk water temperatures at a pressure of 25 MPa. The circular annular test section geometry is a 1.07 cm diameter heater rod within a 4.29 diameter flow channel

  3. Heat Transfer Phenomena in Supercritical Water Nuclear Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Mark H. Anderson; MichaelL. Corradini; Riccardo Bonazza; Jeremy R. Licht

    2007-10-03

    A supercritical water heat transfer facility has been built at the University of Wisconsin to study heat transfer in ancircular and square annular flow channel. A series of integral heat transfer measurements has been carried out over a wide range of heat flux, mas velocity and bulk water temperatures at a pressure of 25 MPa. The circular annular test section geometry is a 1.07 cm diameter heater rod within a 4.29 diameter flow channel.

  4. Heat flux from magmatic hydrothermal systems related to availability of fluid recharge

    Science.gov (United States)

    Harvey, M. C.; Rowland, J.V.; Chiodini, G.; Rissmann, C.F.; Bloomberg, S.; Hernandez, P.A.; Mazot, A.; Viveiros, F.; Werner, Cynthia A.

    2015-01-01

    Magmatic hydrothermal systems are of increasing interest as a renewable energy source. Surface heat flux indicates system resource potential, and can be inferred from soil CO2 flux measurements and fumarole gas chemistry. Here we compile and reanalyze results from previous CO2 flux surveys worldwide to compare heat flux from a variety of magma-hydrothermal areas. We infer that availability of water to recharge magmatic hydrothermal systems is correlated with heat flux. Recharge availability is in turn governed by permeability, structure, lithology, rainfall, topography, and perhaps unsurprisingly, proximity to a large supply of water such as the ocean. The relationship between recharge and heat flux interpreted by this study is consistent with recent numerical modeling that relates hydrothermal system heat output to rainfall catchment area. This result highlights the importance of recharge as a consideration when evaluating hydrothermal systems for electricity generation, and the utility of CO2 flux as a resource evaluation tool.

  5. Water Replacement Schedules in Heat Stress

    Science.gov (United States)

    Londeree, Ben R.; and others

    1969-01-01

    Although early ingestion of cold water appears to lead to greater relief from heat stress during physical exertion than late ingestion, this difference is reduced toward the end of an hour's work in high heat and humidity. (CK)

  6. Analysis of combined heat and mass transfer of water- Vapor in a ...

    African Journals Online (AJOL)

    In this paper, the combined heat and mass transfer of water-vapor into a cylindrical zeolite adsorber has been numerically simulated The twodimensional heat and mass transfer equations are numerically solved using gPROMS program - a general Process Modeling System {lJ program, inserting the proper initial and ...

  7. Analysis of combined heat and mass transfer of water-vapor in a ...

    African Journals Online (AJOL)

    Jn this paper, the combined heat and mass transfer of water-vapor into a cylindrical zeolite adsorber has been numerically simulated The twodimensional heat and mass transfer equations are numerically solved using gPROMS program - a general Process Modeling System [J] program, inserting the proper initial and ...

  8. Combined Space and Water Heating: Next Steps to Improved Performance

    Energy Technology Data Exchange (ETDEWEB)

    Schoenbauer, B. [NorthernSTAR Building America Partnership, Minneapolis, MN (United States); Bohac, D. [NorthernSTAR Building America Partnership, Minneapolis, MN (United States); Huelman, P. [NorthernSTAR Building America Partnership, Minneapolis, MN (United States)

    2016-07-13

    A combined space- and water-heating (combi) system uses a high-efficiency direct-vent burner that eliminates safety issues associated with natural draft appliances. Past research with these systems shows that using condensing water heaters or boilers with hydronic air handling units can provide both space and water heating with efficiencies of 90% or higher. Improved controls have the potential to reduce complexity and improve upon the measured performance. This project demonstrates that controls can significantly benefit these first-generation systems. Laboratory tests and daily load/performance models showed that the set point temperature reset control produced a 2.1%–4.3% (20–40 therms/year) savings for storage and hybrid water heater combi systems operated in moderate-load homes. The full modulation control showed additional savings over set point control (in high-load homes almost doubling the savings: 4%–5% over the no-control case). At the time of installation the reset control can be implemented for $200–$400, which would provide paybacks of 6–25 years for low-load houses and 3–15 years for high-load houses. Full modulation implementation costs would be similar to the outdoor reset and would provide paybacks of 5-½–20 years for low-load houses and 2-½–10 years for high-load houses.

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

    Directory of Open Access Journals (Sweden)

    Mitrović Dejan M.

    2012-01-01

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

  10. Lab-scale experiment of a closed thermochemical heat storage system including honeycomb heat exchanger

    International Nuclear Information System (INIS)

    Fopah-Lele, Armand; Rohde, Christian; Neumann, Karsten; Tietjen, Theo; Rönnebeck, Thomas; N'Tsoukpoe, Kokouvi Edem; Osterland, Thomas; Opel, Oliver

    2016-01-01

    A lab-scale thermochemical heat storage reactor was developed in the European project “thermal battery” to obtain information on the characteristics of a closed heat storage system, based on thermochemical reactions. The present type of storage is capable of re-using waste heat from cogeneration system to produce useful heat for space heating. The storage material used was SrBr 2 ·6H 2 O. Due to agglomeration or gel-like problems, a structural element was introduced to enhance vapour and heat transfer. Honeycomb heat exchanger was designed and tested. 13 dehydration-hydration cycles were studied under low-temperature conditions (material temperatures < 100 °C) for storage. Discharging was realized at water vapour pressure of about 42 mbar. Temperature evolution inside the reactor at different times and positions, chemical conversion, thermal power and overall efficiency were analysed for the selected cycles. Experimental system thermal capacity and efficiency of 65 kWh and 0.77 are respectively obtained with about 1 kg of SrBr 2 ·6H 2 O. Heat transfer fluid recovers heat at a short span of about 43 °C with an average of 22 °C during about 4 h, acceptable temperature for the human comfort (20 °C on day and 16 °C at night). System performances were obtained for a salt bed energy density of 213 kWh·m 3 . The overall heat transfer coefficient of the honeycomb heat exchanger has an average value of 147 W m −2  K −1 . Though promising results have been obtained, ameliorations need to be made, in order to make the closed thermochemical heat storage system competitive for space heating. - Highlights: • Lab-scale thermochemical heat storage is designed, constructed and tested. • The use of honeycomb heat exchanger as a heat and vapour process enhancement. • Closed system (1 kg SrBr 2 ·6H 2 O) able to give back 3/4 of initial thermal waste energy. • System storage capacity and thermal efficiency are respectively 65 kWh and 0.77.

  11. The influence of weather on the thermal performance of solar heating systems

    DEFF Research Database (Denmark)

    Andersen, Elsa; Furbo, Simon; Shah, Louise Jivan

    2003-01-01

    . The investigation is based on calculations with validated models. Solar heating systems with different solar collector types, heat storage volumes and solar fractions are included in the investigation. The yearly solar radiation varies with approximately 20 % in the period from 1990 until 2002. The calculations......The influence of weather on the thermal performance of solar combi systems, solar domestic hot water systems and solar heating plants is investigated. The investigation is based on weather data from the Danish Design Reference Year, DRY and weather data measured for a period from 1990 until 2002...... show that the thermal performance of the investigated systems varies due to the weather variation. The variation of the yearly thermal performance of a solar heating plant is about 40 % while the variation of the yearly thermal performance of a solar domestic hot water system is about 30...

  12. Fiscal 1974 Sunshine Project result report. R and D on solar cooling/heating and hot water supply system (R and D on the system for new detached houses); 1994 nendo taiyo reidanbo oyobi kyuto system no kenkyu kaihatsu. Shinchiku kojin jutakuyo system no kenkyu kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1975-05-30

    This report describes the fiscal 1974 result on the solar cooling/heating and hot water supply system. The report includes the system analysis result (collection of existing technical data, analysis of weather conditions, profitability assessment, concept design of the primary experimental house), and the research result on equipment and materials (view and evaluation of existing technologies, selective transparent and absorption materials, the primary prototype solar heat collector model, refrigerator). As the study result, the spheroidal experimental house was adopted. The solar heat utilization system is a central air-conditioning equipment composed of heating by hot water obtained from the solar heat collector, and cooling by absorption refrigerator. Heat collection efficiencies were measured for (1) stainless steel substrate collector, (2) copper substrate collector, and (3) glass pipe collector prepared as prototype collectors. (2) was higher in heat collection efficiency than (1). The efficiency of (3) hardly increased by rise in heat collection temperature due to vacuum structure and selective absorption membrane. Further measurement of such characteristics is necessary at higher temperatures. (NEDO)

  13. Reports on 1979 result of Sunshine Project. R and D on solar cooling/heating and hot-water supply system (R and D on system for existing private house); 1979 nendo taiyo reidanbo oyobi kyuto system no kenkyu kaihatsu seika hokokusho. Kison kojin jutakuyo system no kenkyu kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1980-05-31

    The following technologies were developed for the purpose of putting into practice an innovative system that performs cooling/heating and hot-water supply for an existing private house economically by solar energy: (1) development of equipment constituting solar cooling/heating and hot-water supply system, and (2) development of a system which uses such equipment and which is inexpensive and safe as well as easy for inspection and maintenance. The results of the research were as follows. A latent heat type heat storage tank was developed in a small low-loss type in which ammonium alum was selected for a high temperature heat storage tank and in which NaCH{sub 3}COO(center dot)3H{sub 2}O were selected for a combination latent heat/cold water heat storage tank. A refrigerator was developed driven by a small Rankine cycle engine of a result coefficient of 0.47. A flat plate type heat collecting device was developed in a type having a BrNi selective absorbing film and materials of copper tube, aluminum plate and double glass. A vacuum heat collecting device was developed in a high efficient type with the outside dimension of {phi} (diameter) 70 x 1,270 mm, selective absorbing film BrNi, and a degree of vacuum of 10{sup -3}Torr. A heat receiving/releasing storm shutter was developed in a type using a latent heat storing material of paraffin wax. A heat absorbing/insulating outside wall panel was developed using FRP and aluminum as the materials. The system analysis also achieved success. (NEDO)

  14. Design change of tower cooling water system for proton accelerator research center

    International Nuclear Information System (INIS)

    Jeon, G. P.; Kim, J. Y.; Song, I. T.; Min, Y. S.; Mun, K. J.; Cho, J. S.; Nam, J. M.; Park, S. S.; Han, Y. G.

    2012-01-01

    The Tower Cooling Water System (TC) is designed to reject the heat load generated by operating the accelerators and the utility facilities through the component cooling water (CCW) heat exchangers. The circulating water discharged from the circulating water pumps passes through the CCW heat exchangers, the Chiller condenser and the air compressor, and the heated circulating water is return to the cooling tower for the heat removal. In this study, The design of Tower Cooling Water System is changed as follows : At First, The quantity of cells is changed into six in order to operate the cooling tower accurately correspond with condition of each equipment of head loads. The fans of cooling tower are controlled by the signal of TEW installed in the latter parts of it. The type of circulation water pump is modified to centrifugal pump and debris filter system is deleted

  15. Design change of tower cooling water system for proton accelerator research center

    Energy Technology Data Exchange (ETDEWEB)

    Jeon, G. P.; Kim, J. Y.; Song, I. T.; Min, Y. S.; Mun, K. J.; Cho, J. S.; Nam, J. M.; Park, S. S.; Han, Y. G. [KAERI, Daejeon (Korea, Republic of)

    2012-10-15

    The Tower Cooling Water System (TC) is designed to reject the heat load generated by operating the accelerators and the utility facilities through the component cooling water (CCW) heat exchangers. The circulating water discharged from the circulating water pumps passes through the CCW heat exchangers, the Chiller condenser and the air compressor, and the heated circulating water is return to the cooling tower for the heat removal. In this study, The design of Tower Cooling Water System is changed as follows : At First, The quantity of cells is changed into six in order to operate the cooling tower accurately correspond with condition of each equipment of head loads. The fans of cooling tower are controlled by the signal of TEW installed in the latter parts of it. The type of circulation water pump is modified to centrifugal pump and debris filter system is deleted.

  16. Wind power integration with heat pumps, heat storages, and electric vehicles - Energy systems analysis and modelling

    Energy Technology Data Exchange (ETDEWEB)

    Hedegaard, K.

    2013-09-15

    This PhD investigates to which extent heat pumps, heat storages, and electric vehicles can support the integration of wind power. Considering the gaps in existing research, the main focus is put on individual heat pumps in the residential sector (one-family houses) and the possibilities for flexible operation, using the heat storage options available. Several energy systems analyses are performed using the energy system models, Balmorel, developed at the former TSO, ElkraftSystem, and, EnergyPLAN, developed at Aalborg University. The Danish energy system towards 2030, with wind power penetrations of up to 60 %, is used as a case study in most of the analyses. Both models have been developed further, resulting in an improved representation of individual heat pumps and heat storages. An extensive model add-on for Balmorel renders it possible to optimise investment and operation of individual heat pumps and different types of heat storages, in integration with the energy system. Total costs of the energy system are minimised in the optimisation. The add-on incorporates thermal building dynamics and covers various different heat storage options: intelligent heat storage in the building structure for houses with radiator heating and floor heating, respectively, heat accumulation tanks on the space heating circuit, as well as hot water tanks. In EnergyPLAN, some of the heat storage options have been modelled in a technical optimisation that minimises fuel consumption of the energy system and utilises as much wind power as possible. The energy systems analyses reveal that in terms of supporting wind power integration, the installation of individual heat pumps is an important step, while adding heat storages to the heat pumps is less influential. When equipping the heat pumps with heat storages, only moderate system benefits can be gained. Hereof, the main system benefit is that the need for peak/reserve capacity investments can be reduced through peak load shaving; in

  17. Thermodynamic analysis and performance assessment of an integrated heat pump system for district heating applications

    International Nuclear Information System (INIS)

    Soltani, Reza; Dincer, Ibrahim; Rosen, Marc A.

    2015-01-01

    A Rankine cycle-driven heat pump system is modeled for district heating applications with superheated steam and hot water as products. Energy and exergy analyses are performed, followed by parametric studies to determine the effects of varying operating conditions and environmental parameters on the system performance. The district heating section is observed to be the most inefficient part of system, exhibiting a relative irreversibility of almost 65%, followed by the steam evaporator and the condenser, with relative irreversibilities of about 18% and 9%, respectively. The ambient temperature is observed to have a significant influence on the overall system exergy destruction. As the ambient temperature decreases, the system exergy efficiency increases. The electricity generated can increase the system exergy efficiency at the expense of a high refrigerant mass flow rate, mainly due to the fact that the available heat source is low quality waste heat. For instance, by adding 2 MW of excess electricity on top of the targeted 6 MW of product heat, the refrigerant mass flow rate increases from 12 kg/s (only heat) to 78 kg/s (heat and electricity), while the production of 8 MW of product heat (same total output, but in form of heat) requires a refrigerant mass flow rate of only 16 kg/s. - Highlights: • A new integrated heat pump system is developed for district heating applications. • An analysis and assessment study is undertaken through exergy analysis methodology. • A comparative efficiency evaluation is performed for practical applications. • A parametric study is conducted to investigate how varying operating conditions and state properties affect energy and exergy efficiencies.

  18. Heat Transfer in Directional Water Transport Fabrics

    Directory of Open Access Journals (Sweden)

    Chao Zeng

    2016-10-01

    Full Text Available Directional water transport fabrics can proactively transfer moisture from the body. They show great potential in making sportswear and summer clothing. While moisture transfer has been previously reported, heat transfer in directional water transport fabrics has been little reported in research literature. In this study, a directional water transport fabric was prepared using an electrospraying technique and its heat transfer properties under dry and wet states were evaluated, and compared with untreated control fabric and the one pre-treated with NaOH. All the fabric samples showed similar heat transfer features in the dry state, and the equilibrium temperature in the dry state was higher than for the wet state. Wetting considerably enhanced the thermal conductivity of the fabrics. Our studies indicate that directional water transport treatment assists in moving water toward one side of the fabric, but has little effect on thermal transfer performance. This study may be useful for development of “smart” textiles for various applications.

  19. Nuclear boiling heat transfer and critical heat flux in titanium dioxide-water nanofluids

    International Nuclear Information System (INIS)

    Okawa, Tomio; Takamura, Masahiro; Kamiya, Takahito

    2011-01-01

    Nucleate boiling heat transfer was experimentally studied for saturated pool boiling of water-based nanofluids. Since significant nanoparticle deposition on the heated surface was observed after the nucleate boiling in nanofluids, measurement of CHF was also carried out using the nanoparticle deposited heated surface; pure water was used in the CHF measurement. In the present work, the heated surface was a 20 mm diameter cupper surface, and titanium-dioxide was selected as the material of nanoparticles. Experiments were performed for upward- and downward-facing surfaces. Although the CHFs for the downward-facing surface were generally lower than those for the upward-facing surface, the CHFs for the nanoparticle deposited surface were about 1.9 times greater than those for the bare surface in both the configurations. The CHF improvement corresponded well to the reduction of the surface contact angle. During the nucleate boiling in nanofluids, the boiling heat transfer showed peculiar behavior; it was first deteriorated, then improved, and finally approached to an equilibrium state. This observation indicated that the present nanofluid had competing effects to deteriorate and improve the nucleate boiling heat transfer. It was assumed that the wettability and the roughness of the heated surface were influenced by the deposited nanoparticles to cause complex variation of the number of active nucleation sites. During the nucleate boiling of pure water using the downward-facing surface, a sudden increase in the wall temperature was observed stochastically probably due to the accumulation of bubbles beneath the heated surface. Such behavior was not observed when the pure water was replaced by the nanofluid. (author)

  20. Heat dissipation research on the water-cooling channel of HL-2M in-vessel coils

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, J., E-mail: jiangjiaming@swip.ac.cn; Liu, Y.; Chen, Q.; Ji, X.Q.

    2017-04-15

    Highlights: • The joule heat of in-vessel coils is very difficult to dissipate inside HL-2M vacuum vessel. • Heat dissipation model of the coil includes the joule heat model, the heat conduction model and the heat transfer model. • The CFD analysis has been done for the coil-water cooling, with comparison with the date of theoretical analysis and experiment. • The result shows water-cooling channel is good for the joule heat transfer and taken away. - Abstract: HL-2M in-vessel coils are positioned in high vacuum circumstance, and they will generate joule heat when they carry 15 kA electrical current, but joule heat is very difficult to dissipate in vacuum, so a hollow cable with 8 mm inner diameter is design as water-cooling channel for heat convection. By using the methods of the theoretical derivation, together with CFD numeric simulation method and the experiment of the heat transfer, the water channel of HL-2M in-vessel coils has been studied, and the temperature of HL-2M in-vessel coils under different cooling water flow rates is obtained and acceptable. Simultaneously, the external cooling water supply system parameters for the water-cooling channel of the coils are estimated. Three methods’ results are in good agreement; the theoretical model is verified and could be popularized for predicting the temperature rise of HL-2M in-vessel coils.