Experimental investigation of the higher coefficient of thermal performance for water-in-glass evacuated tube solar water heaters in China

International Nuclear Information System (INIS)

Zhang, Xinyu; You, Shijun; Xu, Wei; Wang, Min; He, Tao; Zheng, Xuejing

2014-01-01

Highlights: • The energy grades system for solar water heater (SWH) in China was introduced. • Heat loss and capacity of heat collection mainly affected SWH thermal performance. • Optimum ratio of tank volume to collector area for solar water heater is 57 to 72 L/m 2 . • The recommendation polyurethane insulation layer should be around 50 mm thick. • SWH with shorter tube has a better thermal performance. - Abstract: Solar water heaters (SWHs), now widely used in China, represent an environmentally friendly way to heat water. We tested the performance of more than 1000 water-in-glass evacuated tube SWHs according to Chinese standards and found that the heat loss from the storage tank and capacity of the solar collector affected their thermal performance. The optimum parameters to maximize the performance of water-in-glass evacuated tube SWHs included a ratio of tank volume to collector area of 57–72 L/m 2 , which should give a system efficiency of 0.49–0.57, meaning that the temperature of water in the tank will exceed 45 °C after one day of heat collection. In addition, the polyurethane insulation layer should be around 50 mm thick with a free foaming density of about 35 kg/m 3 , and the evacuated tube should be short. The tilt angle did not affect the performance of the SWHs. These results should aid in the design of highly efficient SWHs

Actual performance and economic feasibility of residential solar water heaters

International Nuclear Information System (INIS)

Anhalt, J.

1987-01-01

Four residential solar water heaters currently available on the Brazilian market have been evaluated to their possible use for substituting the common electric shower head. The tests were carried out with the solar systems mounted side by side on an artificial roof. The hot water demand was simulated following a consumer profile which represents a Brazilian family with an income of seven minimum salaries. The data, which was collected automatically and presented in the form of graphs and tables, shows that an optimized solar water heater could save as much as 65% of the energy demand for residential water heating in the state of Sao Paulo. An economical study concludes that the installation and maintenance of such a solar system is feasible if long term financing is available. (author)

Energy efficiency improvement and fuel savings in water heaters using baffles

International Nuclear Information System (INIS)

Moeini Sedeh, Mahmoud; Khodadadi, J.M.

2013-01-01

Highlights: ► Thermal efficiency improved by simple/novel design of baffles inside water reservoir. ► Noticeable steady-state natural gas savings of about 5%. ► Extensive 3-D numerical investigations followed by experimental verifications. ► Baffle designs prototyped in identical water heaters for ANSI/US DOE test protocols. ► Numerical/experimental results verified thermal efficiency improvement and fuel savings. -- Abstract: Thermal efficiency improvement of a water heater was investigated numerically and experimentally in response to presence of a baffle, particularly designed for modifying the flow field within the water reservoir and enhancing heat transfer extracted into the water tank. A residential natural gas-fired water heater was selected for modifying its water tank through introducing a baffle for lowering natural gas consumption by 5% as a target. Based on the geometric features of the selected water heater, three-dimensional models of the water heater subsections were developed. Upon detailed studies of flow and heat transfer in each subsection, various sub-models were integrated to a complete model of the water heater. Thermal performance of the selected water heater was investigated numerically using computational fluid dynamics analysis. Prior to baffle design process and in order to verify the developed model of the water heater, time-dependent numerically-predicted temperatures were compared to the experimentally-measured temperatures under the same conditions at six (6) different locations inside the water tank and good agreement was observed. Upon verifying the numerical model, the fluid flow and heat transfer patterns were characterized for the selected water heater. The overall design of the baffle and its location and orientation were finalized based on the numerical results and a set of parametric studies. Finally, two baffle designs were proposed, with the second design being an optimized version of the first design. The

Solar water heaters in Taiwan

International Nuclear Information System (INIS)

Chang, K.; Lee, T.; Chung, K.

2006-01-01

Solar water heater has been commercialized during the last two decades in Taiwan. The government initiated the incentive programs during 1986-1991 and 2000-2004. This created an economic incentive for the end-users. The total area of solar collectors installed was more than one million square meters. The data also show that most of the solar water heaters are mainly used by the domestic sector for hot water production (about 97%). The regional popularization analysis indicates limited installation of solar water heaters in the northern district. In the eastern district and remote islands, the problems of climatic conditions and availability of localized installers/dealers are addressed. (author)

Feedwater heater performance evaluation using the heat exchanger workstation

International Nuclear Information System (INIS)

Ranganathan, K.M.; Singh, G.P.; Tsou, J.L.

1995-01-01

A Heat Exchanger Workstation (HEW) has been developed to monitor the condition of heat exchanging equipment power plants. HEW enables engineers to analyze thermal performance and failure events for power plant feedwater heaters. The software provides tools for heat balance calculation and performance analysis. It also contains an expert system that enables performance enhancement. The Operation and Maintenance (O ampersand M) reference module on CD-ROM for HEW will be available by the end of 1995. Future developments of HEW would result in Condenser Expert System (CONES) and Balance of Plant Expert System (BOPES). HEW consists of five tightly integrated applications: A Database system for heat exchanger data storage, a Diagrammer system for creating plant heat exchanger schematics and data display, a Performance Analyst system for analyzing and predicting heat exchanger performance, a Performance Advisor expert system for expertise on improving heat exchanger performance and a Water Calculator system for computing properties of steam and water. In this paper an analysis of a feedwater heater which has been off-line is used to demonstrate how HEW can analyze the performance of the feedwater heater train and provide an economic justification for either replacing or repairing the feedwater heater

PERFORMANCE DETERIORATION OF THERMOSIPHON SOLAR FLAT PLATE WATER HEATER DUE TO SCALING

OpenAIRE

arunachala umesh chandavar

2011-01-01

The performance of Flat plate Solar Water Heater deteriorates within five to twelve years of their installation due to factors related to manufacturing, operating conditions, lack of maintenance etc. Especially, problem due to scaling is significant as it is based on quality of water used. The remaining factors are system dependent and could be overcome by quality production. Software is developed by incorporating Hottel Whillier Bliss (H-W-B) equation to ascertain the effect of scaling o...

Space Station solar water heater

Science.gov (United States)

Horan, D. C.; Somers, Richard E.; Haynes, R. D.

1990-01-01

The feasibility of directly converting solar energy for crew water heating on the Space Station Freedom (SSF) and other human-tended missions such as a geosynchronous space station, lunar base, or Mars spacecraft was investigated. Computer codes were developed to model the systems, and a proof-of-concept thermal vacuum test was conducted to evaluate system performance in an environment simulating the SSF. The results indicate that a solar water heater is feasible. It could provide up to 100 percent of the design heating load without a significant configuration change to the SSF or other missions. The solar heater system requires only 15 percent of the electricity that an all-electric system on the SSF would require. This allows a reduction in the solar array or a surplus of electricity for onboard experiments.

Outlook for solar water heaters in Taiwan

International Nuclear Information System (INIS)

Chang, Keh-Chin; Lee, Tsong-Sheng; Chung, Kung-Ming; Lin, Wei-Min

2008-01-01

The share of indigenous energy supply continuously decreases over the last two decades in Taiwan. The development and use of renewable energy sources and technologies are becoming vital for the management of energy supply and demand. For promotion of solar water heaters, the incentive programs were firstly initiated in the period of 1986-1991 and re-initiated from 2000 to the present. These programs create an economic incentive for the end users and have a drastic effect on the popularization of solar water heaters. To further promote solar water heaters during the current incentive program period, several key factors are addressed. In addition to the cost of solar water heaters and energy price index, the potential market of solar water heaters in Taiwan is associated with the climatic conditions, population structure, urbanization, building type of housing and status of new construction. (author)

Outlook for solar water heaters in Taiwan

Energy Technology Data Exchange (ETDEWEB)

Chang, Keh-Chin [Department of Aeronautical and Astronautical Engineering, National Cheng Kung University, Kueijen, Tainan, Taiwan 711 (China); Lee, Tsong-Sheng; Chung, Kung-Ming [Aerospace Science and Technology Research Center, National Cheng Kung University, Kueijen, Tainan, Taiwan 711 (China); Lin, Wei-Min [Tainan University of Technology (China)

2008-01-15

The share of indigenous energy supply continuously decreases over the last two decades in Taiwan. The development and use of renewable energy sources and technologies are becoming vital for the management of energy supply and demand. For promotion of solar water heaters, the incentive programs were firstly initiated in the period of 1986-1991 and re-initiated from 2000 to the present. These programs create an economic incentive for the end users and have a drastic effect on the popularization of solar water heaters. To further promote solar water heaters during the current incentive program period, several key factors are addressed. In addition to the cost of solar water heaters and energy price index, the potential market of solar water heaters in Taiwan is associated with the climatic conditions, population structure, urbanization, building type of housing and status of new construction. (author)

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.

Integrated collector-storage solar water heater with extended storage unit

International Nuclear Information System (INIS)

Kumar, Rakesh; Rosen, Marc A.

2011-01-01

The integrated collector-storage solar water heater (ICSSWH) is one of the simplest designs of solar water heater. In ICSSWH systems the conversion of solar energy into useful heat is often simple, efficient and cost effective. To broaden the usefulness of ICSSWH systems, especially for overnight applications, numerous design modifications have been proposed and analyzed in the past. In the present investigation the storage tank of an ICSSWH is coupled with an extended storage section. The total volume of the modified ICSSWH has two sections. Section A is exposed to incoming solar radiation, while section B is insulated on all sides. An expression is developed for the natural convection flow rate in section A. The inter-related energy balances are written for each section and solved to ascertain the impact of the extended storage unit on the water temperature and the water heater efficiency. The volumes of water in the two sections are optimized to achieve a maximum water temperature at a reasonably high efficiency. The influence is investigated of inclination angle of section A on the temperature of water heater and the angle is optimized. It is determined that a volume ratio of 7/3 between sections A and B yields the maximum water temperature and efficiency in the modified solar water heater. The performance of the modified water heater is also compared with a conventional ICSSWH system under similar conditions.

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.

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...

Predictive Power of Machine Learning for Optimizing Solar Water Heater Performance: The Potential Application of High-Throughput Screening

Directory of Open Access Journals (Sweden)

Hao Li

2017-01-01

Full Text Available Predicting the performance of solar water heater (SWH is challenging due to the complexity of the system. Fortunately, knowledge-based machine learning can provide a fast and precise prediction method for SWH performance. With the predictive power of machine learning models, we can further solve a more challenging question: how to cost-effectively design a high-performance SWH? Here, we summarize our recent studies and propose a general framework of SWH design using a machine learning-based high-throughput screening (HTS method. Design of water-in-glass evacuated tube solar water heater (WGET-SWH is selected as a case study to show the potential application of machine learning-based HTS to the design and optimization of solar energy systems.

Experimental Investigation of a Natural Circulation Solar Domestic Water Heater Performance under Standard Consumption Rate

DEFF Research Database (Denmark)

Kolaei, Alireza Rezania; Taherian, H.; Ganji, D. D.

2012-01-01

This paper reports experimental studies on the performance of a natural circulation solar water heater considering the weather condition of a city in north of Iran. The tests are done on clear and partly cloudy days. The variations of storage tank temperature due to consumption from the tank, daily...... consumption influence on the solar water heater efficiency, and on the input temperature of the collector are studied and the delivered daily useful energy has been obtained. The results show that by withdrawing from storage tank, the system as well as its collector efficiency will increase. Considering...... the value of the coefficient FRUL and τα, which are obtained experimentally as 6.03 and 0.83 respectively, average. monthly total load that is covered by this solar water heating system is estimated....

Development of an Accurate Feed-Forward Temperature Control Tankless Water Heater

Energy Technology Data Exchange (ETDEWEB)

David Yuill

2008-06-30

The following document is the final report for DE-FC26-05NT42327: Development of an Accurate Feed-Forward Temperature Control Tankless Water Heater. This work was carried out under a cooperative agreement from the Department of Energy's National Energy Technology Laboratory, with additional funding from Keltech, Inc. The objective of the project was to improve the temperature control performance of an electric tankless water heater (TWH). The reason for doing this is to minimize or eliminate one of the barriers to wider adoption of the TWH. TWH use less energy than typical (storage) water heaters because of the elimination of standby losses, so wider adoption will lead to reduced energy consumption. The project was carried out by Building Solutions, Inc. (BSI), a small business based in Omaha, Nebraska. BSI partnered with Keltech, Inc., a manufacturer of electric tankless water heaters based in Delton, Michigan. Additional work was carried out by the University of Nebraska and Mike Coward. A background study revealed several advantages and disadvantages to TWH. Besides using less energy than storage heaters, TWH provide an endless supply of hot water, have a longer life, use less floor space, can be used at point-of-use, and are suitable as boosters to enable alternative water heating technologies, such as solar or heat-pump water heaters. Their disadvantages are their higher cost, large instantaneous power requirement, and poor temperature control. A test method was developed to quantify performance under a representative range of disturbances to flow rate and inlet temperature. A device capable of conducting this test was designed and built. Some heaters currently on the market were tested, and were found to perform quite poorly. A new controller was designed using model predictive control (MPC). This control method required an accurate dynamic model to be created and required significant tuning to the controller before good control was achieved. The MPC

A high turndown, ultra low emission low swirl burner for natural gas, on-demand water heaters

Energy Technology Data Exchange (ETDEWEB)

Rapp, Vi H. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Cheng, Robert K. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Therkelsen, Peter L. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

2017-06-13

Previous research has shown that on-demand water heaters are, on average, approximately 37% more efficient than storage water heaters. However, approximately 98% of water heaters in the U.S. use storage water heaters while the remaining 2% are on-demand. A major market barrier to deployment of on-demand water heaters is their high retail cost, which is due in part to their reliance on multi-stage burner banks that require complex electronic controls. This project aims to research and develop a cost-effective, efficient, ultra-low emission burner for next generation natural gas on-demand water heaters in residential and commercial buildings. To meet these requirements, researchers at the Lawrence Berkeley National Laboratory (LBNL) are adapting and testing the low-swirl burner (LSB) technology for commercially available on-demand water heaters. In this report, a low-swirl burner is researched, developed, and evaluated to meet targeted on-demand water heater performance metrics. Performance metrics for a new LSB design are identified by characterizing performance of current on-demand water heaters using published literature and technical specifications, and through experimental evaluations that measure fuel consumption and emissions output over a range of operating conditions. Next, target metrics and design criteria for the LSB are used to create six 3D printed prototypes for preliminary investigations. Prototype designs that proved the most promising were fabricated out of metal and tested further to evaluate the LSB’s full performance potential. After conducting a full performance evaluation on two designs, we found that one LSB design is capable of meeting or exceeding almost all the target performance metrics for on-demand water heaters. Specifically, this LSB demonstrated flame stability when operating from 4.07 kBTU/hr up to 204 kBTU/hr (50:1 turndown), compliance with SCAQMD Rule 1146.2 (14 ng/J or 20 ppm NOX @ 3% O2), and lower CO emissions than state

Strategy Guideline: Proper Water Heater Selection

Energy Technology Data Exchange (ETDEWEB)

Hoeschele, M. [Alliance for Residential Building Innovation, Davis, CA (United States); Springer, D. [Alliance for Residential Building Innovation, Davis, CA (United States); German, A. [Alliance for Residential Building Innovation, Davis, CA (United States); Staller, J. [Alliance for Residential Building Innovation, Davis, CA (United States); Zhang, Y. [Alliance for Residential Building Innovation, Davis, CA (United States)

2015-04-01

This Strategy Guideline on proper water heater selection was developed by the Building America team Alliance for Residential Building Innovation to provide step-by-step procedures for evaluating preferred cost-effective options for energy efficient water heater alternatives based on local utility rates, climate, and anticipated loads.

Strategy Guideline. Proper Water Heater Selection

Energy Technology Data Exchange (ETDEWEB)

Hoeschele, M. [Alliance for Residential Building Innovation (ARBI), Davis, CA (United States); Springer, D. [Alliance for Residential Building Innovation (ARBI), Davis, CA (United States); German, A. [Alliance for Residential Building Innovation (ARBI), Davis, CA (United States); Staller, J. [Alliance for Residential Building Innovation (ARBI), Davis, CA (United States); Zhang, Y. [Alliance for Residential Building Innovation (ARBI), Davis, CA (United States)

2015-04-09

This Strategy Guideline on proper water heater selection was developed by the Building America team Alliance for Residential Building Innovation to provide step-by-step procedures for evaluating preferred cost-effective options for energy efficient water heater alternatives based on local utility rates, climate, and anticipated loads.

Integrated solar water-heater and solar water cooler performance during winter time

International Nuclear Information System (INIS)

Shaikh, N.U.; Siddiqui, M.A

2012-01-01

Solar powered water heater and water cooler is an important contribution for the reduction of fossil fuel consumptions and harmful emissions to the environment. This study aims to harness the available solar potential of Pakistan and provide an option fulfilling the domestic hot and cold water demands during winter and summer seasons respectively. The system was designed for the tap-water temperature of 65 degree C (149 degree F) and the chilled drinking-water temperature of 14 degree C (57 degree F) that are the recommended temperatures by World Health Organization (WHO). The solar water heater serves one of the facilities of the Department of Mechanical Engineering at NED University of Engineering and Technology whereas, the solar water cooler will provide drinking water to approximately 50 people including both faculty and students. A pair of single glazed flat plate solar collector was installed to convert solar radiations to heat. Hot water storage and supply system was carefully designed and fabricated to obtain the designed tap-water temperature. Vapour-absorption refrigeration system was designed to chill drinking water. Intensity of solar radiations falling on the solar collector, water temperatures at the inlet and outlet of the solar collectors and the tap water temperature were measured and analyzed at different hours of the day and at different days of the month. The results show that the installed solar collector system has potential to feed hot water of temperatures ranging from 65 degree C (149 degree F) to 70 Degree C (158 degree F), that is the required hot water temperature to operate a vapour absorption chilled water production system. (author)

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.

Heat Pump Water Heaters and American Homes: A Good Fit?

Energy Technology Data Exchange (ETDEWEB)

Franco, Victor; Lekov, Alex; Meyers, Steve; Letschert, Virginie

2010-05-14

Heat pump water heaters (HPWHs) are over twice as energy-efficient as conventional electric resistance water heaters, with the potential to save substantial amounts of electricity. Drawing on analysis conducted for the U.S. Department of Energy's recently-concluded rulemaking on amended standards for water heaters, this paper evaluates key issues that will determine how well, and to what extent, this technology will fit in American homes. The key issues include: 1) equipment cost of HPWHs; 2) cooling of the indoor environment by HPWHs; 3) size and air flow requirements of HPWHs; 4) performance of HPWH under different climate conditions and varying hot water use patterns; and 5) operating cost savings under different electricity prices and hot water use. The paper presents the results of a life-cycle cost analysis of the adoption of HPWHs in a representative sample of American homes, as well as national impact analysis for different market share scenarios. Assuming equipment costs that would result from high production volume, the results show that HPWHs can be cost effective in all regions for most single family homes, especially when the water heater is not installed in a conditioned space. HPWHs are not cost effective for most manufactured home and multi-family installations, due to lower average hot water use and the water heater in the majority of cases being installed in conditioned space, where cooling of the indoor environment and size and air flow requirements of HPWHs increase installation costs.

Water hammers in direct contact heater systems

International Nuclear Information System (INIS)

Uffer, R.

1983-01-01

This paper discusses the causes and mitigation or prevention of water hammers occurring in direct contact heaters and their attached lines. These water hammers are generally caused by rapid pressure reductions in the heaters or by water lines not flowing full. Proper design and operating measures can prevent or mitigate water hammer occurrence. Water hammers often do not originate at the areas where damage is noted

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.

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

Energy Savings and Breakeven Costs for Residential Heat Pump Water Heaters in the United States

Energy Technology Data Exchange (ETDEWEB)

Maguire, Jeff [National Renewable Energy Lab. (NREL), Golden, CO (United States); Burch, Jay [National Renewable Energy Lab. (NREL), Golden, CO (United States); Merrigan, Tim [National Renewable Energy Lab. (NREL), Golden, CO (United States); Ong, Sean [National Renewable Energy Lab. (NREL), Golden, CO (United States)

2013-07-01

Heat pump water heaters (HPWHs) have recently re-emerged in the U.S. residential water heating market and have the potential to provide homeowners with significant energy savings. However, there are questions as to the actual performance and energy savings potential of these units, in particular in regards to the heat pump's performance in unconditioned space and the impact of the heat pump on space heating and cooling loads when it is located in conditioned space. To help answer these questions, NREL performed simulations of a HPWH in both conditioned and unconditioned space at over 900 locations across the continental United States and Hawaii. Simulations included a Building America benchmark home so that any interaction between the HPWH and the home's HVAC equipment could be captured. Comparisons were performed to typical gas and electric water heaters to determine the energy savings potential and cost effectiveness of a HPWH relative to these technologies. HPWHs were found to have a significant source energy savings potential when replacing typical electric water heaters, but only saved source energy relative to gas water heater in the most favorable installation locations in the southern United States. When replacing an electric water heater, the HPWH is likely to break even in California, the southern United States, and parts of the northeast in most situations. However, the HPWH will only break even when replacing a gas water heater in a few southern states.

Energy Savings and Breakeven Cost for Residential Heat Pump Water Heaters in the United States

Energy Technology Data Exchange (ETDEWEB)

Maguire, J.; Burch, J.; Merrigan, T.; Ong, S.

2013-07-01

Heat pump water heaters (HPWHs) have recently reemerged in the U.S. residential water heating market and have the potential to provide homeowners with significant energy savings. However, there are questions as to the actual performance and energy savings potential of these units, in particular in regards to the heat pump's performance in unconditioned space and the impact of the heat pump on space heating and cooling loads when it is located in conditioned space. To help answer these questions, simulations were performed of a HPWH in both conditioned and unconditioned space at over 900 locations across the continental United States and Hawaii. Simulations included a Building America benchmark home so that any interaction between the HPWH and the home's HVAC equipment could be captured. Comparisons were performed to typical gas and electric water heaters to determine the energy savings potential and cost effectiveness of a HPWH relative to these technologies. HPWHs were found to have a significant source energy savings potential when replacing typical electric water heaters, but only saved source energy relative to gas water heater in the most favorable installation locations in the southern US. When replacing an electric water heater, the HPWH is likely to break even in California, the southern US, and parts of the northeast in most situations. However, the HPWH will only break even when replacing a gas water heater in a few southern states.

Electric Water Heater Modeling and Control Strategies for Demand Response

Energy Technology Data Exchange (ETDEWEB)

Diao, Ruisheng; Lu, Shuai; Elizondo, Marcelo A.; Mayhorn, Ebony T.; Zhang, Yu; Samaan, Nader A.

2012-07-22

Abstract— Demand response (DR) has a great potential to provide balancing services at normal operating conditions and emergency support when a power system is subject to disturbances. Effective control strategies can significantly relieve the balancing burden of conventional generators and reduce investment on generation and transmission expansion. This paper is aimed at modeling electric water heaters (EWH) in households and tests their response to control strategies to implement DR. The open-loop response of EWH to a centralized signal is studied by adjusting temperature settings to provide regulation services; and two types of decentralized controllers are tested to provide frequency support following generator trips. EWH models are included in a simulation platform in DIgSILENT to perform electromechanical simulation, which contains 147 households in a distribution feeder. Simulation results show the dependence of EWH response on water heater usage . These results provide insight suggestions on the need of control strategies to achieve better performance for demand response implementation. Index Terms— Centralized control, decentralized control, demand response, electrical water heater, smart grid

Nocturnal reverse flow in water-in-glass evacuated tube solar water heaters

International Nuclear Information System (INIS)

Tang, Runsheng; Yang, Yuqin

2014-01-01

Highlights: • Performance of water-in-glass evacuated tube solar water heaters (SWH) at night was studied. • Experimental measurements showed that reverse flow occurred in SWHs at night. • Reverse flow in SWHs was very high but the heat loss due to reverse flow was very low. • Reverse flow seemed not sensitive to atmospheric clearness but sensitive to collector tilt-angle. - Abstract: In this work, the thermal performance of water-in-glass evacuated tube solar water heaters (SWH) at nights was experimentally investigated. Measurements at nights showed that the water temperature in solar tubes was always lower than that in the water tank but higher than the ambient air temperature and T exp , the temperature of water inside tubes predicted in the case of the water in tubes being naturally cooled without reverse flow. This signified that the reverse flow in the system occurred at nights, making the water in solar tubes higher than T exp . It is found that the reverse flow rate in the SWH, estimated based on temperature measurements of water in solar tubes, seemed not sensitive to the atmospheric clearness but sensitive to the collector tilt-angle, the larger the tilt-angle of the collector, the higher the reverse flow rate. Experimental results also showed that, the reverse flow in the SWH was much higher as compared to that in a thermosyphonic domestic solar water heater with flat-plate collectors, but the heat loss from collectors to the air due to reverse flow in SWHs was very small and only took about 8–10% of total heat loss of systems

Recovery Act: Water Heater ZigBee Open Standard Wireless Controller

Energy Technology Data Exchange (ETDEWEB)

Butler, William P. [Emerson Electric Co., St. Louis, MO (United States); Buescher, Tom [Emerson Electric Co., St. Louis, MO (United States)

2014-04-30

The objective of Emerson's Water Heater ZigBee Open Standard Wireless Controller is to support the DOE's AARA priority for Clean, Secure Energy by designing a water heater control that levels out residential and small business peak electricity demand through thermal energy storage in the water heater tank.

Solar Water Heater Installation Package

Science.gov (United States)

1982-01-01

A 48-page report describes water-heating system, installation (covering collector orientation, mounting, plumbing and wiring), operating instructions and maintenance procedures. Commercial solar-powered water heater system consists of a solar collector, solar-heated-water tank, electrically heated water tank and controls. Analysis of possible hazards from pressure, electricity, toxicity, flammability, gas, hot water and steam are also included.

Effect of Installation of Solar Collector on Performance of Balcony Split Type Solar Water Heaters

Directory of Open Access Journals (Sweden)

Xu Ji

2015-01-01

Full Text Available The influences of surface orientation and slope of solar collectors on solar radiation collection of balcony split type solar water heaters for six cities in China were analyzed by employing software TRNSYS. The surface azimuth had greater effect on solar radiation collection in high latitude regions. For deviation of the surface slope angle within ±20° around the optimized angle, the variation of the total annual collecting solar radiation was less than 5%. However, with deviation of 70° to 90°, the variation was up to 20%. The effects of water cycle mode, reverse slope placement of solar collector, and water tank installation height on system efficiency were experimentally studied. The thermal efficiencies of solar water heater with single row horizontal arrangement all-glass evacuated tubular collector were higher than those with vertical arrangement at the fixed surface slope angle of 90°. Compared with solar water heaters with flat-plate collector under natural circulation, the system thermal efficiency was raised up to 63% under forced circulation. For collector at reverse slope placement, the temperature-based water stratification in water tank deteriorated, and thus the thermal efficiency became low. For improving the system efficiency, an appropriate installation height of the water tank was suggested.

Molded polymer solar water heater

Science.gov (United States)

Bourne, Richard C.; Lee, Brian E.

2004-11-09

A solar water heater has a rotationally-molded water box and a glazing subassembly disposed over the water box that enhances solar gain and provides an insulating air space between the outside environment and the water box. When used with a pressurized water system, an internal heat exchanger is integrally molded within the water box. Mounting and connection hardware is included to provide a rapid and secure method of installation.

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

International Nuclear Information System (INIS)

Xu Guoying; Zhang Xiaosong; Deng Shiming

2006-01-01

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

Optimal and Learning-Based Demand Response Mechanism for Electric Water Heater System

Directory of Open Access Journals (Sweden)

Bo Lin

2017-10-01

Full Text Available This paper investigates how to develop a learning-based demand response approach for electric water heater in a smart home that can minimize the energy cost of the water heater while meeting the comfort requirements of energy consumers. First, a learning-based, data-driven model of an electric water heater is developed by using a nonlinear autoregressive network with external input (NARX using neural network. The model is updated daily so that it can more accurately capture the actual thermal dynamic characteristics of the water heater especially in real-life conditions. Then, an optimization problem, based on the NARX water heater model, is formulated to optimize energy management of the water heater in a day-ahead, dynamic electricity price framework. A genetic algorithm is proposed in order to solve the optimization problem more efficiently. MATLAB (R2016a is used to evaluate the proposed learning-based demand response approach through a computational experiment strategy. The proposed approach is compared with conventional method for operation of an electric water heater. Cost saving and benefits of the proposed water heater energy management strategy are explored.

Economics of residential gas furnaces and water heaters in United States new construction market

OpenAIRE

Lekov, Alex B.

2009-01-01

New single-family home construction represents a significant and important market for the introduction of energy-efficient gas-fired space heating and water-heating equipment. In the new construction market, the choice of furnace and water-heater type is primarily driven by first cost considerations and the availability of power vent and condensing water heaters. Few analysis have been performed to assess the economic impacts of the different combinations of space and water-heating equipment....

Economics of residential gas furnaces and water heaters in United States new construction market

Energy Technology Data Exchange (ETDEWEB)

Lekov, Alex B.; Franco, Victor H.; Wong-Parodi, Gabrielle; McMahon, James E.; Chan, Peter

2009-05-06

New single-family home construction represents a significant and important market for the introduction of energy-efficient gas-fired space heating and water-heating equipment. In the new construction market, the choice of furnace and water-heater type is primarily driven by first cost considerations and the availability of power vent and condensing water heaters. Few analysis have been performed to assess the economic impacts of the different combinations of space and water-heating equipment. Thus, equipment is often installed without taking into consideration the potential economic and energy savings of installing space and water-heating equipment combinations. In this study, we use a life-cycle cost analysis that accounts for uncertainty and variability of the analysis inputs to assess the economic benefits of gas furnace and water-heater design combinations. This study accounts not only for the equipment cost but also for the cost of installing, maintaining, repairing, and operating the equipment over its lifetime. Overall, this study, which is focused on US single-family new construction households that install gas furnaces and storage water heaters, finds that installing a condensing or power-vent water heater together with condensing furnace is the most cost-effective option for the majority of these houses. Furthermore, the findings suggest that the new construction residential market could be a target market for the large-scale introduction of a combination of condensing or power-vent water heaters with condensing furnaces.

An overview of the development of solar water heater industry in China

International Nuclear Information System (INIS)

Runqing, Hu; Peijun, Sun; Zhongying, Wang

2012-01-01

This article introduce the development of China solar water heater industry .Gives an overview of stages, market, manufacturing, application and testing about China solar water heater industry. Show the market data from 1998 to 2009. Analyze the experiences and features about the industry. The article also introduces the policy for solar hot water industry in China. These policies have accelerated the development of industry in which the main two incentive policies have the greatest influence on solar water heater industry. First one is the policy of mandatory installation of solar water heater implemented since 2007 by some local governments at provincial and municipal levels. Second is the subsidy policy for solar water heaters in the household appliances going to the countryside scheme implemented since 2009. At last the article gives the reason why China solar water heater industry have so rapid growth. From technology research, industrialization, prices and policy environment gives analysis. - Highlights: ► We compared International and China market about solar thermal products. ► The reason for rapid development of China solar water heater is explained. ► The experience of China solar water heater industry would give reference to other develop country. ► “Meet the demands of customer” is the main driver for the solar water heater industry development. ► The policy framework about China solar thermal industry was introduced. The industry achieved commercial operation without subsidy.

Technical support document: Energy efficiency standards for consumer products: Room air conditioners, water heaters, direct heating equipment, mobile home furnaces, kitchen ranges and ovens, pool heaters, fluorescent lamp ballasts and television sets. Volume 3, Water heaters, pool heaters, direct heating equipment, and mobile home furnaces

Energy Technology Data Exchange (ETDEWEB)

1993-11-01

This is Volume 3 in a series of documents on energy efficiency of consumer products. This volume discusses energy efficiency of water heaters. Water heaters are defined by NAECA as products that utilize oil, gas, or electricity to heat potable water for use outside the heater upon demand. These are major appliances, which use a large portion (18% on average) of total energy consumed per household (1). They differ from most other appliances in that they are usually installed in obscure locations as part of the plumbing and are ignored until they fail. Residential water heaters are capable of heating water up to 180{degrees}F, although the setpoints are usually set lower.

Measure Guideline: Heat Pump Water Heaters in New and Existing Homes

Energy Technology Data Exchange (ETDEWEB)

Shapiro, C.; Puttagunta, S.; Owens, D.

2012-02-01

This Building America Measure Guideline is intended for builders, contractors, homeowners, and policy-makers. This document is intended to explore the issues surrounding heat pump water heaters (HPWHs) to ensure that homeowners and contractors have the tools needed to appropriately and efficiently install HPWHs. Heat pump water heaters (HPWHs) promise to significantly reduce energy consumption for domestic hot water (DHW) over standard electric resistance water heaters (ERWHs). While ERWHs perform with energy factors (EFs) around 0.9, new HPWHs boast EFs upwards of 2.0. High energy factors in HPWHs are achieved by combining a vapor compression system, which extracts heat from the surrounding air at high efficiencies, with electric resistance element(s), which are better suited to meet large hot water demands. Swapping ERWHs with HPWHs could result in roughly 50% reduction in water heating energy consumption for 35.6% of all U.S. households. This Building America Measure Guideline is intended for builders, contractors, homeowners, and policy-makers. While HPWHs promise to significantly reduce energy use for DHW, proper installation, selection, and maintenance of HPWHs is required to ensure high operating efficiency and reliability. This document is intended to explore the issues surrounding HPWHs to ensure that homeowners and contractors have the tools needed to appropriately and efficiently install HPWHs. Section 1 of this guideline provides a brief description of HPWHs and their operation. Section 2 highlights the cost and energy savings of HPWHs as well as the variables that affect HPWH performance, reliability, and efficiency. Section 3 gives guidelines for proper installation and maintenance of HPWHs, selection criteria for locating HPWHs, and highlights of important differences between ERWH and HPWH installations. Throughout this document, CARB has included results from the evaluation of 14 heat pump water heaters (including three recently released HPWH

Assessment of a Hybrid Retrofit Gas Water Heater

Energy Technology Data Exchange (ETDEWEB)

Hoeschele, Marc [Davis Energy Group, Davis, CA (United States); Weitzel, Elizabeth [Davis Energy Group, Davis, CA (United States); Backman, Christine [Davis Energy Group, Davis, CA (United States)

2017-02-28

This project completed a modeling evaluation of a hybrid gas water heater that combines a reduced capacity tankless unit with a downsized storage tank. This product would meet a significant market need by providing a higher efficiency gas water heater solution for retrofit applications while maintaining compatibility with the 1/2 inch gas lines and standard B vents found in most homes. The TRNSYS simulation tool was used to model a base case 0.60 EF atmospheric gas storage water, a 0.82 EF non-condensing gas tankless water heater, an existing (high capacity) hybrid unit on the market, and an alternative hybrid unit with lower storage volume and reduced gas input requirements. Simulations were completed under a 'peak day' sizing scenario with 183 gpd hot water loads in a Minnesota winter climate case. Full-year simulations were then completed in three climates (ranging from Phoenix to Minneapolis) for three hot water load scenarios (36, 57, and 96 gpd). Model projections indicate that the alternative hybrid offers an average 4.5% efficiency improvement relative to the 0.60 EF gas storage unit across all scenarios modeled. The alternative hybrid water heater evaluated does show promise, but the current low cost of natural gas across much of the country and the relatively small incremental efficiency improvement poses challenges in initially building a market demand for the product.

Assessment of a Hybrid Retrofit Gas Water Heater

Energy Technology Data Exchange (ETDEWEB)

Hoeschele, Marc [Alliance for Residential Building Innovation (ARBI), Davis, CA (United States); Weitzel, Elizabeth [Alliance for Residential Building Innovation (ARBI), Davis, CA (United States); Backman, Christine [Alliance for Residential Building Innovation (ARBI), Davis, CA (United States)

2017-02-01

This project completed a modeling evaluation of a hybrid gas water heater that combines a reduced capacity tankless unit with a downsized storage tank. This product would meet a significant market need by providing a higher efficiency gas water heater solution for retrofit applications while maintaining compatibility with the 1/2 inch gas lines and standard B vents found in most homes. The TRNSYS simulation tool was used to model a base case 0.60 EF atmospheric gas storage water, a 0.82 EF non-condensing gas tankless water heater, an existing (high capacity) hybrid unit on the market, and an alternative hybrid unit with lower storage volume and reduced gas input requirements. Simulations were completed under a 'peak day' sizing scenario with 183 gpd hot water loads in a Minnesota winter climate case. Full-year simulations were then completed in three climates (ranging from Phoenix to Minneapolis) for three hot water load scenarios (36, 57, and 96 gpd). Model projections indicate that the alternative hybrid offers an average 4.5% efficiency improvement relative to the 0.60 EF gas storage unit across all scenarios modeled. The alternative hybrid water heater evaluated does show promise, but the current low cost of natural gas across much of the country and the relatively small incremental efficiency improvement poses challenges in initially building a market demand for the product.

Comparative Experimental Analysis of the Thermal Performance of Evacuated Tube Solar Water Heater Systems With and Without a Mini-Compound Parabolic Concentrating (CPC Reflector(C < 1

Directory of Open Access Journals (Sweden)

Yuehong Su

2012-04-01

Full Text Available Evacuated tube solar water heater systems are widely used in China due to their high thermal efficiency, simple construction requirements, and low manufacturing costs. CPC evacuated tube solar water heaters with a geometrical concentration ratio C of less than one are rare. A comparison of the experimental rig of evacuated tube solar water heater systems with and without a mini-CPC reflector was set up, with a series of experiments done in Hefei (31°53'N, 117°15'E, China. The first and second laws of thermodynamics were used to analyze and contrast their thermal performance. The water in the tank was heated from 26.9 to 55, 65, 75, 85, and 95 °C. Two types of solar water heater systems were used, and the data gathered for two days were compared. The results show that when attaining low temperature water, the evacuated tube solar water heater system without a mini-CPC reflector has higher thermal and exergy efficiencies than the system with a mini-CPC reflector, including the average and immediate values. On the other hand, when attaining high temperature water, the system with a mini-CPC reflector has higher thermal and exergy efficiencies than the other one. The comparison presents the advantages of evacuated tube solar water heater systems with and without a mini-CPC reflector, which can be offered as a reference when choosing which solar water system to use for actual applications.

Solar water heater design package

Science.gov (United States)

1981-01-01

Package describes commercial domestic-hot-water heater with roof or rack mounted solar collectors. System is adjustable to pre-existing gas or electric hot-water house units. Design package includes drawings, description of automatic control logic, evaluation measurements, possible design variations, list of materials and installation tools, and trouble-shooting guide and manual.

10 CFR 431.102 - Definitions concerning commercial water heaters, hot water supply boilers, and unfired hot water...

Science.gov (United States)

2010-01-01

... supply boilers, and unfired hot water storage tanks. 431.102 Section 431.102 Energy DEPARTMENT OF ENERGY... Water Heaters, Hot Water Supply Boilers and Unfired Hot Water Storage Tanks § 431.102 Definitions concerning commercial water heaters, hot water supply boilers, and unfired hot water storage tanks. The...

High Efficiency Water Heating Technology Development Final Report. Part I, Lab/Field Performance Evaluation and Accelerated Life Testing of a Hybrid Electric Heat Pump Water Heater (HPWH)

Energy Technology Data Exchange (ETDEWEB)

Baxter, Van D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Murphy, Richard W. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Rice, C. Keith [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Linkous, Randall Lee [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

2016-04-01

DOE has supported efforts for many years with the objective of getting a water heater that uses heat pump technology (aka a heat pump water heater or HPWH) successfully on the residential equipment market. The most recent previous effort (1999-2002) produced a product that performed very well in ORNL-led accelerated durability and field tests. The commercial partner for this effort, Enviromaster International (EMI), introduced the product to the market under the trade name Watter$aver in 2002 but ceased production in 2005 due to low sales. A combination of high sales price and lack of any significant infrastructure for service after the sale were the principal reasons for the failure of this effort. What was needed for market success was a commercial partner with the manufacturing and market distribution capability necessary to allow economies of scale to lead to a viable unit price together with a strong customer service infrastructure. General Electric certainly meets these requirements, and knowing of ORNL s expertise in this area, approached ORNL with the proposal to partner in a CRADA to produce a high efficiency electric water heater. A CRADA with GE was initiated early in Fiscal Year, 2008. GE initially named its product the Hybrid Electric Water Heater (HEWH).

An International Survey of Electric Storage Tank Water Heater Efficiency and Standards

Energy Technology Data Exchange (ETDEWEB)

Johnson, Alissa; Lutz, James; McNeil, Michael A.; Covary, Theo

2013-11-13

Water heating is a main consumer of energy in households, especially in temperate and cold climates. In South Africa, where hot water is typically provided by electric resistance storage tank water heaters (geysers), water heating energy consumption exceeds cooking, refrigeration, and lighting to be the most consumptive single electric appliance in the home. A recent analysis for the Department of Trade and Industry (DTI) performed by the authors estimated that standing losses from electric geysers contributed over 1,000 kWh to the annual electricity bill for South African households that used them. In order to reduce this burden, the South African government is currently pursuing a programme of Energy Efficiency Standards and Labelling (EES&L) for electric appliances, including geysers. In addition, Eskom has a history of promoting heat pump water heaters (HPWH) through incentive programs, which can further reduce energy consumption. This paper provides a survey of international electric storage water heater test procedures and efficiency metrics which can serve as a reference for comparison with proposed geyser standards and ratings in South Africa. Additionally it provides a sample of efficiency technologies employed to improve the efficiency of electric storage water heaters, and outlines programs to promote adoption of improved efficiency. Finally, it surveys current programs used to promote HPWH and considers the potential for this technology to address peak demand more effectively than reduction of standby losses alone

Techno-economıc Analysıs of Evacuated Tube Solar Water Heater usıng F-chart Method

Science.gov (United States)

Fayaz, H.; Rahim, N. A.; Saidur, R.; Hasanuzzaman, M.

2018-05-01

Solar thermal utilization, especially the application of solar water heater technology, has developed rapidly in recent decades. Solar water heating systems based on thermal collector alone or connected with photovoltaic called as photovoltaic-thermal (PVT) are practical applications to replace the use of electrical water heaters but weather dependent performance of these systems is not linear. Therefore on the basis of short term or average weather conditions, accurate analysis of performance is quite difficult. The objective of this paper is to show thermal and economic analysis of evacuated tube collector solar water heaters. Analysis done by F-Chart shows that evacuated tube solar water heater achieves fraction value of 1 to fulfil hot water demand of 150liters and above per day for a family without any auxiliary energy usage. Evacuated tube solar water heater show life cycle savings of RM 5200. At water set temperature of 100°C, RM 12000 is achieved and highest life cycle savings of RM 6100 at the environmental temperature of 18°C are achieved. Best thermal and economic performance is obtained which results in reduction of household greenhouse gas emissions, reduction of energy consumption and saves money on energy bills.

Evaluation of the service quality of solar water-heaters; Evaluation de la qualite de service des chauffe-eau solaires

Energy Technology Data Exchange (ETDEWEB)

Buscarlet, C.; Filloux, A.

1998-12-31

This small booklet is the result of research studies carried out for the evaluation of solar water-heater performances, including service quality. Service quality is evaluated according to the capacity of production of `useful` hot water (hot water above a given temperature) and to the influence of the daily profile of drawing up on the performances of the water-heater. Procedures have been developed that allow to determine these indicators without the need of supplementary tests. A suggestion of information file for solar water-heaters without auxiliary heating is proposed which presents for each type of apparatus a synthetic information about its performances and service quality. (J.S.)

One-year assessment of a solar space/water heater--Clinton, Mississippi

Science.gov (United States)

1981-01-01

Unit called "System 4" integrated into space-heating and hot-water systems of dormitory satisfied 32 percent of building heat load. System 4 includes flat-plate air collectors, circulation blowers, rock storage bed with heat exchanger, two hot water tanks, and auxiliary heaters. Report describes performance of system and subsystems, operating-energy requirements and savings, and performance parameters.

Solar Water-Heater Design and Installation

Science.gov (United States)

Harlamert, P.; Kennard, J.; Ciriunas, J.

1982-01-01

Solar/Water heater system works as follows: Solar--heated air is pumped from collectors through rock bin from top to bottom. Air handler circulates heated air through an air-to-water heat exchanger, which transfers heat to incoming well water. In one application, it may reduce oil use by 40 percent.

Experimentation of a Solar Water Heater with Integrated Storage Tank

International Nuclear Information System (INIS)

Elhmidi, I; Frikha, N; Chaouchi, B; Gabsi, S

2009-01-01

An integrated collector storage (ICS) solar water heater was constructed in 2004 and studied its optical and thermal performance. It was revealed that it has some thermal shortcomings of thermal performances. The ICS system consists of one cylindrical horizontal tank properly mounted in a stationary symmetrical Compound Parabolic Concentrating (CPC) reflector trough. The main objective was to delimit the causes of these deficiencies and trying to diagnose them. A rigorous experimentation of the solar water heater has been done over its daily energetic output as well as the evolution of the nocturnal thermal losses. In fact, three successive days, including nights, of operation have permitted to obtain diagrams describing the variations of mean temperature in the tank and the thermal loss coefficient during night of our installation. The experimental results, compared with those obtained by simulation, showed a perfecting of thermal performances of system which approach from those of other models introduced on the international market

Performance evaluation of an integrated solar water heater as an option for building energy conservation

Energy Technology Data Exchange (ETDEWEB)

Dharuman, C.; Arakeri, J.H.; Srinivasan, K. [Indian Inst. of Science, Bangalaore (India). Dept. of Mechanical Engineering

2006-03-15

Since a majority of residential and industrial building hot water needs are around 50 {sup o}C, an integrated solar water heater could provide a bulk source that blends collection and storage into one unit. This paper describes the design, construction and performance test results of one such water-heating device. The test unit has an absorber area of 1.3 m{sup 2} and can hold 170 l of water, of which extractable volume per day is 100 l. Its performance was evaluated under various typical operating conditions. Every morning at about 7:00 a.m., 100 l of hot water were drawn from the sump and replaced with cold water from the mains. Although, during most of the days, the peak temperatures of water obtained are between 50 and 60 {sup o}C, the next morning temperatures were lower at 45-50 {sup o}C. Daytime collection efficiencies of about 60% and overall efficiencies of about 40% were obtained. Tests were conducted with and without stratification. Night radiation losses were reduced by use of a screen insulation. (author)

Reliable, Economic, Efficient CO2 Heat Pump Water Heater for North America

Energy Technology Data Exchange (ETDEWEB)

Radcliff, Thomas D; Sienel, Tobias; Huff, Hans-Joachim; Thompson, Adrian; Sadegh, Payman; Olsommer, Benoit; Park, Young

2006-12-31

Adoption of heat pump water heating technology for commercial hot water could save up to 0.4 quads of energy and 5 million metric tons of CO2 production annually in North America, but industry perception is that this technology does not offer adequate performance or reliability and comes at too high of a cost. Development and demonstration of a CO2 heat pump water heater is proposed to reduce these barriers to adoption. Three major themes are addressed: market analysis to understand barriers to adoption, use of advanced reliability models to design optimum qualification test plans, and field testing of two phases of water heater prototypes. Market experts claim that beyond good performance, market adoption requires 'drop and forget' system reliability and a six month payback of first costs. Performance, reliability and cost targets are determined and reliability models are developed to evaluate the minimum testing required to meet reliability targets. Three phase 1 prototypes are designed and installed in the field. Based on results from these trials a product specification is developed and a second phase of five field trial units are built and installed. These eight units accumulate 11 unit-years of service including 15,650 hours and 25,242 cycles of compressor operation. Performance targets can be met. An availability of 60% is achieved and the capability to achieve >90% is demonstrated, but overall reliability is below target, with an average of 3.6 failures/unit-year on the phase 2 demonstration. Most reliability issues are shown to be common to new HVAC products, giving high confidence in mature product reliability, but the need for further work to minimize leaks and ensure reliability of the electronic expansion valve is clear. First cost is projected to be above target, leading to an expectation of 8-24 month payback when substituted for an electric water heater. Despite not meeting all targets, arguments are made that an industry leader could

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.

Energy Efficiency Modelling of Residential Air Source Heat Pump Water Heater

Directory of Open Access Journals (Sweden)

Cong Toan Tran

2016-03-01

Full Text Available The heat pump water heater is one of the most energy efficient technologies for heating water for household use. The present work proposes a simplified model of coefficient of performance and examines its predictive capability. The model is based on polynomial functions where the variables are temperatures and the coefficients are derived from the Australian standard test data, using regression technics. The model enables to estimate the coefficient of performance of the same heat pump water heater under other test standards (i.e. US, Japanese, European and Korean standards. The resulting estimations over a heat-up phase and a full test cycle including a draw off pattern are in close agreement with the measured data. Thus the model allows manufacturers to avoid the need to carry out physical tests for some standards and to reduce product cost. The limitations of the methodology proposed are also discussed.

Application of a Linear Input/Output Model to Tankless Water Heaters

Energy Technology Data Exchange (ETDEWEB)

Butcher T.; Schoenbauer, B.

2011-12-31

In this study, the applicability of a linear input/output model to gas-fired, tankless water heaters has been evaluated. This simple model assumes that the relationship between input and output, averaged over both active draw and idle periods, is linear. This approach is being applied to boilers in other studies and offers the potential to make a small number of simple measurements to obtain the model parameters. These parameters can then be used to predict performance under complex load patterns. Both condensing and non-condensing water heaters have been tested under a very wide range of load conditions. It is shown that this approach can be used to reproduce performance metrics, such as the energy factor, and can be used to evaluate the impacts of alternative draw patterns and conditions.

Condensation heat transfer of a feed-water heater and improvement of its performance

International Nuclear Information System (INIS)

Takamori, Kazuhide; Murase, Michio; Baba, Yoshikazu; Aihara, Tsuyoshi

1995-01-01

In this study, a condensation heat transfer model, coupled with a three-dimensional two-phase flow analysis, was developed. In the heat transfer model, the liquid film flow rate on the heat transfer tubes was calculated by a mass balance equation and the liquid film thickness was calculated from the liquid film flow rate using Nusselt's laminar flow model and Fujii's equation for the steam velocity effect. The model was verified by condensation heat transfer experiments. In the experiments, 112 horizontal, staggered tubes with an outer diameter of 16mm and length of 0.55m were used. The calculated over-all heat transfer coefficients agreed with the data within ±5% under the inlet quality conditions of 13-100%. Based on a three-dimensional two-phase flow analysis, an improved feed-water heater with support plates, which have flow holes between the upper and lower tube bundles, was designed. The total heat exchange capacity of the improved feed-water heater increased about 6%. (author)

Field Monitoring Protocol. Heat Pump Water Heaters

Energy Technology Data Exchange (ETDEWEB)

Sparn, B. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Earle, L. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Christensen, D. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Maguire, J. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Wilson, E. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Hancock, C. E. [Mountain Energy Partnership, Longmont, CO (United States)

2013-02-01

This document provides a standard field monitoring protocol for evaluating the installed performance of Heat Pump Water Heaters in residential buildings. The report is organized to be consistent with the chronology of field test planning and execution. Research questions are identified first, followed by a discussion of analysis methods, and then the details of measuring the required information are laid out. A field validation of the protocol at a house near the NREL campus is included for reference.

Field Monitoring Protocol: Heat Pump Water Heaters

Energy Technology Data Exchange (ETDEWEB)

Sparn, B.; Earle, L.; Christensen, D.; Maguire, J.; Wilson, E.; Hancock, E.

2013-02-01

This document provides a standard field monitoring protocol for evaluating the installed performance of Heat Pump Water Heaters in residential buildings. The report is organized to be consistent with the chronology of field test planning and execution. Research questions are identified first, followed by a discussion of analysis methods, and then the details of measuring the required information are laid out. A field validation of the protocol at a house near the NREL campus is included for reference.

Solar water heater for NASA's Space Station

Science.gov (United States)

Somers, Richard E.; Haynes, R. Daniel

1988-01-01

The feasibility of using a solar water heater for NASA's Space Station is investigated using computer codes developed to model the Space Station configuration, orbit, and heating systems. Numerous orbit variations, system options, and geometries for the collector were analyzed. Results show that a solar water heater, which would provide 100 percent of the design heating load and would not impose a significant impact on the Space Station overall design is feasible. A heat pipe or pumped fluid radial plate collector of about 10-sq m, placed on top of the habitat module was found to be well suited for satisfying water demand of the Space Station. Due to the relatively small area required by a radial plate, a concentrator is unnecessary. The system would use only 7 to 10 percent as much electricity as an electric water-heating system.

Air source heat pump water heater: Dynamic modeling, optimal energy management and mini-tubes condensers

International Nuclear Information System (INIS)

Ibrahim, Oussama; Fardoun, Farouk; Younes, Rafic; Louahlia-Gualous, Hasna

2014-01-01

This paper presents a dynamic simulation model to predict the performance of an ASHPWH (air source heat pump water heater). The developed model is used to assess its performance in the Lebanese context. It is shown that for the four Lebanese climatic zones, the expected monthly values of the average COP (coefficient of performance) varies from 2.9 to 5, leading to high efficiencies compared with conventional electric water heaters. The energy savings and GHG (greenhouse gas) emissions reduction are investigated for each zone. Furthermore, it is recommended to use the ASHPWH during the period of highest daily ambient temperatures (noon or afternoon), assuming that the electricity tariff and hot water loads are constant. In addition, an optimal management model for the ASHPWH is developed and applied for a typical winter day of Beirut. Moreover, the developed dynamic model of ASHPWH is used to compare the performance of three similar systems that differ only with the condenser geometry, where results show that using mini-condenser geometries increase the COP (coefficient of performance) and consequently, more energy is saved as well as more GHG emissions are reduced. In addition, the condenser “surface compactness” is increased giving rise to an efficient compact heat exchanger. - Highlights: • Numerical modeling and experimental validation for ASHPWH (air source heat pump water heater). • Optimization of the ASHPWH-condenser length. • Comparison of the ASHPWH with conventional electric water heater according to energy efficiency and green gas house emissions. • Development of an energetic-economic optimal management model for ASHPWH. • Energetic and environmental assessment of ASHPWH with mini-tubes condensers

Preheating Water In The Covers Of Solar Water Heaters

Science.gov (United States)

Bhandari, Pradeep

1995-01-01

Solar water heaters that include glass covers over absorber plates redesigned to increase efficiencies according to proposal. Redesign includes modification of single-layer glass cover into double-layer glass cover and addition of plumbing so cool water to be heated made to flow between layers of cover before entering absorber plate.

Modeling of a split type air conditioner with integrated water heater

International Nuclear Information System (INIS)

Techarungpaisan, P.; Theerakulpisut, S.; Priprem, S.

2007-01-01

This paper presents a steady state simulation model to predict the performance of a small split type air conditioner with integrated water heater. The mathematical model consists of submodels of system components such as evaporator, condenser, compressor, capillary tube, receiver and water heater. These submodels were built based on fundamental principles of heat transfer, thermodynamics, fluid mechanics, empirical relationships and manufacturer's data as necessary. The model was coded into a simulation program and used to predict system parameters of interest such as hot water temperature, condenser exit air temperature, evaporator exit air temperature, mass flow rate of refrigerant, heat rejection in the condenser and cooling capacity of the system. The simulation results were compared with experimental data obtained from an experimental rig built for validating the mathematical model. It was found that the experimental and simulation results are in good agreement

Performance Study of a Cylindrical Parabolic Concentrating Solar Water Heater with Nail Type Twisted Tape Inserts in the Copper Absorber Tube

Directory of Open Access Journals (Sweden)

Amit K. Bhakta

2018-01-01

Full Text Available This paper reports the overall thermal performance of a cylindrical parabolic concentrating solar water heater (CPCSWH with inserting nail type twisted tape (NTT in the copper absorber tube for the nail twist pitch ratios, 4.787, 6.914 and 9.042, respectively. The experiments are conducted for a constant volumetric water flow rate and during the time period 9:00 a.m. to 15:00 p.m. The useful heat gain, hourly solar energy collected and hourly solar energy stored in this solar water heater were found to be higher for the nail twist pitch ratio 4.787. The above said parameters were found to be at a peak at noon and observed to follow the path of variation of solar intensity. At the start of the experiment, the value of charging efficiency was observed to be maximum, whereas the maximum values of instantaneous efficiency and overall thermal efficiency were observed at noon. The key finding is that the nail twist pitch ratio enhances the overall thermal performance of the CPCSWH.

Experimental and theoretical evaluation of the performance of a tar solar water heater

International Nuclear Information System (INIS)

Ammari, H.D.; Nimir, Y.L.

2003-01-01

The paper presents an experimental and theoretical evaluation of the performance of a tar solar water heater and comparison with that of a conventional type collector. The performance of both collectors is assessed under the same conditions. Both of the collectors have the same surface area and are glazed. The conventional type has the water tubes welded to the absorber plate, whereas in the tar type, the tar acts as an absorber plate that covers the water tubes. The theoretical model for each collector type, with the transient effects taken into account, is based on a control volume and a time base in the related energy equations. By considering a small element of the collector in each case, three partial differential equations were developed for each collector and were solved numerically by the Runge-Kutta method of the fifth order. A good agreement was achieved between the numerical and experimental results for both the conventional and tar collectors, indicating the feasibility of employing the theoretical model in the design of flat plate solar collectors. The results also showed that the conventional collector is more efficient than the tar type during most of the daylight, but the tar collector had the added advantage of better conservation of energy in late afternoon and evening

Research and development of a heat-pump water heater. Volume 2. R and D task reports

Energy Technology Data Exchange (ETDEWEB)

Dunning, R.L.; Amthor, F.R.; Doyle, E.J.

1978-08-01

The heat pump water heater is a device that works much like a window air conditioner except that heat from the home is pumped into a water tank rather than to the outdoors. The objective established for the device is to operate with a Coefficient of Performance (COP) of 3 or, an input of one unit of electric energy would create three units of heat energy in the form of hot water. With such a COP, the device would use only one-third the energy and at one-third the cost of a standard resistance water heater. This Volume 2 contains the final reports of the three major tasks performed in Phase I. In Task 2, a market study identifies the future market and selects an initial target market and channel of distribution, all based on an analysis of the parameters affecting feasibility of the device and the factors that will affect its market acceptance. In the Task 3 report, the results of a design and test program to arrive at final designs of heat pumps for both new water heaters and for retrofitting existing water heaters are presented. In the Task 4 report, a plan for an extensive field demonstration involving use in actual homes is presented. Volume 1 contains a final summary report of the information in Volume 2.

Analysis of Large- Capacity Water Heaters in Electric Thermal Storage Programs

Energy Technology Data Exchange (ETDEWEB)

Cooke, Alan L. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Anderson, David M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Winiarski, David W. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Carmichael, Robert T. [Cadeo Group, Washington D. C. (United States); Mayhorn, Ebony T. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Fisher, Andrew R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

2015-03-17

This report documents a national impact analysis of large tank heat pump water heaters (HPWH) in electric thermal storage (ETS) programs and conveys the findings related to concerns raised by utilities regarding the ability of large-tank heat pump water heaters to provide electric thermal storage services.

Dissemination of Solar Water Heaters in Taiwan: The Case of Remote Islands

Directory of Open Access Journals (Sweden)

Kung-Ming Chung

2013-10-01

Full Text Available Solar water heaters represent the success story in the development of renewable energy in Taiwan. With increasing public awareness, there are over 0.3 million residential systems in operation. To disseminate solar water heaters in remote islands, economic feasibility and water quality are taken into account in this study. The payback period in Kinmen and Penghu Counties are evaluated, according to effective annual solar energy gain, hot water consumption pattern and cost. Assessment of the scaling and corrosion tendencies for solar water heaters using tap and underground water are also presented. For flat-plate solar collectors with metal components, favorable corrosion resistance and protective anti-corrosion coatings are required.

Control and Coordination of Frequency Responsive Residential Water Heaters

Energy Technology Data Exchange (ETDEWEB)

Williams, Tess L.; Kalsi, Karanjit; Elizondo, Marcelo A.; Marinovici, Laurentiu D.; Pratt, Richard M.

2016-07-31

Demand-side frequency control can complement traditional generator controls to maintain the stability of large electric systems in the face of rising uncertainty and variability associated with renewable energy resources. This paper presents a hierarchical frequency-based load control strategy that uses a supervisor to flexibly adjust control gains that a population of end-use loads respond to in a decentralized manner to help meet the NERC BAL-003-1 frequency response standard at both the area level and interconnection level. The load model is calibrated and used to model populations of frequency-responsive water heaters in a PowerWorld simulation of the U.S. Western Interconnection (WECC). The proposed design is implemented and demonstrated on physical water heaters in a laboratory setting. A significant fraction of the required frequency response in the WECC could be supplied by electric water heaters alone at penetration levels of less than 15%, while contributing to NERC requirements at the interconnection and area levels.

High-temperature MEMS Heater Platforms: Long-term Performance of Metal and Semiconductor Heater Materials

Directory of Open Access Journals (Sweden)

Theodor Doll

2006-04-01

Full Text Available Micromachined thermal heater platforms offer low electrical power consumptionand high modulation speed, i.e. properties which are advantageous for realizing non-dispersive infrared (NDIR gas- and liquid monitoring systems. In this paper, we report oninvestigations on silicon-on-insulator (SOI based infrared (IR emitter devices heated byemploying different kinds of metallic and semiconductor heater materials. Our resultsclearly reveal the superior high-temperature performance of semiconductor over metallicheater materials. Long-term stable emitter operation in the vicinity of 1300 K could beattained using heavily antimony-doped tin dioxide (SnO2:Sb heater elements.

77 FR 74559 - Energy Conservation Program for Consumer Products: Test Procedures for Residential Water Heaters...

Science.gov (United States)

2012-12-17

... Conservation Program for Consumer Products: Test Procedures for Residential Water Heaters, Direct Heating... Energy (DOE) is amending its test procedures for residential water heaters, direct heating equipment (DHE... necessary for residential water heaters, because the existing test procedures for those products already...

76 FR 56347 - Energy Conservation Program for Consumer Products: Test Procedures for Residential Water Heaters...

Science.gov (United States)

2011-09-13

... Conservation Program for Consumer Products: Test Procedures for Residential Water Heaters, Direct Heating... proposed to amend, where appropriate, its test procedures for residential water heaters, direct heating... notes that the test procedure and metric for residential water heaters currently address and incorporate...

Environmental aspects of the use of materials for solar water heaters

International Nuclear Information System (INIS)

Van der Leun, C.J.; De Jager, D.

1994-10-01

The study on the title subject has been carried out in order to apply the results in new designs and to improve the production of solar water heating systems. Attention is paid to solar water heaters that are under development and solar water heaters that are commercially available in the Netherlands. Use has been made of a IVAM-developed product analysis method. For seven solar water heater concepts, that were on the market or under development in the Netherlands in 1992, the applied amounts of materials have been inventorized. Data on the environmental effects of the production of these materials are outlined and aggregated on the level of the components and the systems. Based on those data, environmental profiles are drafted, comprising 'effect scores' on 9 environmental criteria. However, the environmental 'effect scores' are not reliable enough to determine the most important factors in order to identify options to reduce the negative environmental effects. Data on the energy consumption of the production of relevant materials are available and reliable. The solar water heaters, considered in this report, do not show large differences for that matter. It appears that the amounts of air pollution, water pollution and waste flow from the production of materials for solar water heaters are no reasons to further reduce environmental effects of the production. It is recommended to focus on the reduction of material quantities and to increase the quantity of recycled material. Also it is recommended that manufacturers of solar boilers set up a take-back system. 43 tabs., 1 appendix, 56 refs

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%.

Thermal performance of an integrated collector storage solar water heater (ICSSWH) with phase change materials (PCM)

International Nuclear Information System (INIS)

Chaabane, Monia; Mhiri, Hatem; Bournot, Philippe

2014-01-01

Highlights: • We study the effect of phase change materials integration on the thermal performances of an ICSSWH. • Two kinds and tree radiuses of the PCM layer are studied and the most appropriate design is presented. • The use of phase change materials in ICSSWH is determined to reduce the night thermal losses. • Myristic acid is the most appropriate PCM for this application regarding the daily and night operation. - Abstract: In this paper, we propose a numerical study of an integrated collector storage solar water heater (ICSSWH). Two numerical models in three-dimensional modeling are developed. The first one which describes a sensible heat storage unit (SHSU), allowing validating the numerical model. Based on the good agreement between numerical results and experimental data from literature, and as this type of solar water heater presents the disadvantage of its high night losses, we propose to integrate a phase change material (PCM) directly in the collector and to study its effect on the ICSSWH thermal performance. Indeed, a second 3D CFD model is developed and series of numerical simulations are conducted for two kind (myristic acid and RT42-graphite) and three radiuses (R = 0.2 m, R = 0.25 m and R = 0.3 m) of this PCM layer. Numerical results show that during the day-time, the latent heat storage unit (LHSU) performs better than the sensible one when myristic acid is used as PCM. Regarding the night operating of this solar system, it is found that the LHSU is more effective for both PCMs as it allows lower thermal losses and better heat preservation

Performance characteristics of solar air heater with surface mounted obstacles

International Nuclear Information System (INIS)

Bekele, Adisu; Mishra, Manish; Dutta, Sushanta

2014-01-01

Highlights: • Solar air heater with delta shaped obstacles have been studied. • Obstacle angle of incidence strongly affects the thermo-hydraulic performance. • Thermal performance of obstacle mounted collectors is superior to smooth collectors. • Thermo-hydraulic performance of the present SAH is higher than those in previous studies. - Abstract: The performance of conventional solar air heaters (SAHs) can be improved by providing obstacles on the heated wall (i.e. on the absorber plate). Experiments have been performed to collect heat transfer and flow-friction data from an air heater duct with delta-shaped obstacles mounted on the absorber surface and having an aspect ratio 6:1 resembling the conditions close to the solar air heaters. This study encompassed for the range of Reynolds number (Re) from 2100 to 30,000, relative obstacle height (e/H) from 0.25 to 0.75, relative obstacle longitudinal pitch (P l /e) from 3/2 to 11/2, relative obstacle transverse pitch (P t /b) from 1 to 7/3 and the angle of incidence (α) varied from 30° to 90°. The thermo-hydraulic performance characteristics of SAH have been compared with the previous published works and the optimum range of the geometries have been explored for the better performance of such air-heaters compared to the other designs of solar air heaters

Fuzzy Logic Approach to Diagnosis of Feedwater Heater Performance Degradation

International Nuclear Information System (INIS)

Kang, Yeon Kwan; Kim, Hyeon Min; Heo, Gyun Young; Sang, Seok Yoon

2014-01-01

Since failure in, damage to, and performance degradation of power generation components in operation under harsh environment of high pressure and high temperature may cause both economic and human loss at power plants, highly reliable operation and control of these components are necessary. Therefore, a systematic method of diagnosing the condition of these components in its early stages is required. There have been many researches related to the diagnosis of these components, but our group developed an approach using a regression model and diagnosis table, specializing in diagnosis relating to thermal efficiency degradation of power plant. However, there was a difficulty in applying the method using the regression model to power plants with different operating conditions because the model was sensitive to value. In case of the method that uses diagnosis table, it was difficult to find the level at which each performance degradation factor had an effect on the components. Therefore, fuzzy logic was introduced in order to diagnose performance degradation using both qualitative and quantitative results obtained from the components' operation data. The model makes performance degradation assessment using various performance degradation variables according to the input rule constructed based on fuzzy logic. The purpose of the model is to help the operator diagnose performance degradation of components of power plants. This paper makes an analysis of power plant feedwater heater by using fuzzy logic. Feedwater heater is one of the core components that regulate life-cycle of a power plant. Performance degradation has a direct effect on power generation efficiency. It is not easy to observe performance degradation of feedwater heater. However, on the other hand, troubles such as tube leakage may bring simultaneous damage to the tube bundle and therefore it is the object of concern in economic aspect. This study explains the process of diagnosing and verifying typical

Fuzzy Logic Approach to Diagnosis of Feedwater Heater Performance Degradation

Energy Technology Data Exchange (ETDEWEB)

Kang, Yeon Kwan; Kim, Hyeon Min; Heo, Gyun Young [Kyung Hee University, Yongin (Korea, Republic of); Sang, Seok Yoon [Engineering and Technical Center, Korea Hydro, Daejeon (Korea, Republic of)

2014-08-15

Since failure in, damage to, and performance degradation of power generation components in operation under harsh environment of high pressure and high temperature may cause both economic and human loss at power plants, highly reliable operation and control of these components are necessary. Therefore, a systematic method of diagnosing the condition of these components in its early stages is required. There have been many researches related to the diagnosis of these components, but our group developed an approach using a regression model and diagnosis table, specializing in diagnosis relating to thermal efficiency degradation of power plant. However, there was a difficulty in applying the method using the regression model to power plants with different operating conditions because the model was sensitive to value. In case of the method that uses diagnosis table, it was difficult to find the level at which each performance degradation factor had an effect on the components. Therefore, fuzzy logic was introduced in order to diagnose performance degradation using both qualitative and quantitative results obtained from the components' operation data. The model makes performance degradation assessment using various performance degradation variables according to the input rule constructed based on fuzzy logic. The purpose of the model is to help the operator diagnose performance degradation of components of power plants. This paper makes an analysis of power plant feedwater heater by using fuzzy logic. Feedwater heater is one of the core components that regulate life-cycle of a power plant. Performance degradation has a direct effect on power generation efficiency. It is not easy to observe performance degradation of feedwater heater. However, on the other hand, troubles such as tube leakage may bring simultaneous damage to the tube bundle and therefore it is the object of concern in economic aspect. This study explains the process of diagnosing and verifying typical

Report of the workshop Energy Utility and Solar Water Heater 1993

International Nuclear Information System (INIS)

1993-01-01

The title workshop was organized to increase the interest of energy utilities for the Solar Water Heater campaign by providing representatives of the utilities with information about the technical and marketing aspects of solar boilers, and to stimulate knowledge transfer between the energy utilities about the method, the possibilities and bottlenecks of solar water heater projects

Survey of large-scale solar water heaters installed in Taiwan, China

Energy Technology Data Exchange (ETDEWEB)

Chang Keh-Chin; Lee Tsong-Sheng; Chung Kung-Ming [Cheng Kung Univ., Tainan (China); Lien Ya-Feng; Lee Chine-An [Cheng Kung Univ. Research and Development Foundation, Tainan (China)

2008-07-01

Almost all the solar collectors installed in Taiwan, China were used for production of hot water for homeowners (residential systems), in which the area of solar collectors is less than 10 square meters. From 2001 to 2006, there were only 39 large-scale systems (defined as the area of solar collectors being over 100 m{sup 2}) installed. Their utilization purposes are for rooming house (dormitory), swimming pool, restaurant, and manufacturing process. A comprehensive survey of those large-scale solar water heaters was conducted in 2006. The objectives of the survey were to asses the systems' performance and to have the feedback from the individual users. It is found that lack of experience in system design and maintenance are the key factors for reliable operation of a system. For further promotion of large-scale solar water heaters in Taiwan, a more compressive program on a system design for manufacturing process should be conducted. (orig.)

Building America Case Study: Assessment of a Hybrid Retrofit Gas Water Heater

Energy Technology Data Exchange (ETDEWEB)

M. Hoeschele, E. Weitzel, C. Backman

2017-06-01

This project completed a modeling evaluation of a hybrid gas water heater that combines a reduced capacity tankless unit with a downsized storage tank. This product would meet a significant market need by providing a higher efficiency gas water heater solution for retrofit applications while maintaining compatibility with the half-inch gas lines and standard B vents found in most homes. The TRNSYS simulation tool was used to model a base case 0.60 EF atmospheric gas storage water, a 0.82 EF non-condensing gas tankless water heater, an existing (high capacity) hybrid unit on the market, and an alternative hybrid unit with lower storage volume and reduced gas input requirements.

The study of production performance of water heater manufacturing by using simulation method

Science.gov (United States)

Iqbal, M.; Bamatraf, OAA; Tadjuddin, M.

2018-02-01

In industrial companies, as demand increases, decision-making to increase production becomes difficult due to the complexity of the model systems. Companies are trying to find the optimum methods to tackle such problems so that resources are utilized and production is increased. One line system of a manufacturing company in Malaysia was considered in this research. The Company produces several types of water heater and each type went into many processes, which was divided into twenty six sections. Each section has several operations. The main type of the product was 10G water heater which is produced most compare to other types, hence it was taken under consideration to be studied in this research. It was difficult to find the critical section that could improve the productions of the company. This research paper employed Delmia Quest software, Distribution Analyser software and Design of Experiment (DOE software) to simulate one model system taken from the company to be studied and to find the critical section that will improve the production system. As a result, assembly of inner and outer tank section were found to be the bottleneck section. Adding one section to the bottleneck increases the production rate by four products a day. The buffer size is determined by the experiment was six items.

Understanding the Ecological Adoption of Solar Water Heaters Among Customers of Island Economies

Directory of Open Access Journals (Sweden)

Pudaruth Sharmila

2017-04-01

Full Text Available This paper explores the major factors impacting upon the ecological adoption of solar water heaters in Mauritius. The paper applies data reduction technique by using exploratory factor analysis on a sample of 228 respondents and condenses a set of 32 attributes into a list of 8 comprehensible factors impacting upon the sustained adoption of solar water heater in Mauritius. Multiple regression analysis was also conducted to investigate upon the most predictive factor influencing the adoption of solar water heaters in Mauritius. The empirical estimates of the regression analysis have also depicted that the most determining factor pertaining to the ‘government incentives for solar water heaters’ impacts upon the adoption of solar water heaters. These results can be related to sustainable adoption of green energy whereby targeted incentive mechanisms can be formulated with the aim to accelerate and cascade solar energy adoption in emerging economies. A novel conceptual model was also proposed in this paper, whereby, ecological stakeholders in the sustainable arena could use the model as a reference to pave the way to encourage adoption of solar water heating energy. This research represents a different way of understanding ecological customers by developing an expanding on an original scale development for the survey on the ecological adoption of solar water heaters.

Research and development of a high efficiency gas-fired water heater. Volume 2. Task reports

Energy Technology Data Exchange (ETDEWEB)

Vasilakis, A.D.; Pearson, J.F.; Gerstmann, J.

1980-01-01

Design and development of a cost-effective high efficiency gas-fired water heater to attain a service efficiency of 70% (including the effect of exfiltration) and a service efficiency of 78% (excluding exfiltration) for a 75 GPD draw at a 90/sup 0/F temperature rise, with a stored water to conditioned air temperature difference of 80/sup 0/F, are described in detail. Based on concept evaluation, a non-powered natural draft water heater was chosen as the most cost-effective design to develop. The projected installed cost is $374 compared to $200 for a conventional unit. When the project water heater is compared to a conventional unit, it has a payback of 3.7 years and life cycle savings of $350 to the consumer. A prototype water heater was designed, constructed, and tested. When operated with sealed combustion, the unit has a service efficiency of 66.4% (including the effect of exfiltration) below a burner input of 32,000 Btu/h. In the open combustion configuration, the unit operated at a measured efficiency of 66.4% Btu/h (excluding exfiltration). This compares with a service efficiency of 51.3% for a conventional water heater and 61% for a conventional high efficiency unit capable of meeting ASHRAE 90-75. Operational tests showed the unit performed well with no evidence of stacking or hot spots. It met or exceeded all capacity or usage tests specified in the program test plan and met all emission goals. Future work will concentrate on designing, building, and testing pre-production units. It is anticipated that both sealed combustion and open draft models will be pursued.

South Africa. Fertile ground for solar water heaters

Energy Technology Data Exchange (ETDEWEB)

Oirere, Shem

2012-07-01

The national solar water heating plan, launched by South Africa's state power utility Eskom, seems to be making good progress with the power generator saying at least 215,000 solar water heater (SWH) systems had been installed by February this year. (orig.)

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.

Wasted Heat Engine Utilization in Central AC Condenser Type Water Chiller for Economical Energy Water Heaters

Directory of Open Access Journals (Sweden)

I Made Rasta

2012-11-01

Full Text Available Central AC type water chiller is a refrigeration machine that release heat to environment. Heat energy that released to environment comes from room heat load that absorbed by machine and heat from compressor. The best form in using this loss energy is heat recovery water heater technology, where this machine will take heat from condenser by a heat exchanger to heating water. Refrigerant will flow in the heat exchanger before entering condenser, after that refrigerant flow to other components such as, expansion valve, evaporator, compressor and than return again to condenser, this process will be cycling regularly (closed cycle. Based on experimental and analysis result especially for AC with capacity 2 Pk, and tank capacity 75 liter, with water heater recovery device obtained that: (1 Compressor power consumption decrease from 1.66 kW to 1.59kW. (2 Heat rejected from condenser and used by water heater has ratio 4.683 kJ/s and 1.59 kJ/s, with water heater efficiency is 32.2%. (3 Maximum water temperature can be reached are in range 34oC – 47.5oC in 10-150 minutes and flow rate is 0.5 – 2.5 liter /min

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.

Solar air heaters and their applications

Science.gov (United States)

Selcuk, M. K.

1977-01-01

The solar air heater appears to be the most logical choice, as far as the ultimate application of heating air to maintain a comfortable environment is concerned. One disadvantage of solar air heaters is the need for handling larger volumes of air than liquids due to the low density of air as a working substance. Another disadvantage is the low thermal capacity of air. In cases where thermal storage is needed, water is superior to air. Design variations of solar air heaters are discussed along with the calculation of the efficiency of a flat plate solar air heater, the performance of various collector types, and the applications of solar air heaters. Attention is given to collectors with nonporous absorber plates, collectors with porous absorbers, the performance of flat plate collectors with finned absorbers, a wire mesh absorber, and an overlapped glass plate air heater.

Experimental study on the performance of a multi-functional domestic air conditioner with integrated water heater

International Nuclear Information System (INIS)

Dong, Jiankai; Li, Hui; Yao, Yang; Jiang, Yiqiang; Zhang, Xinran

2017-01-01

Highlights: • A novel MDACWH was presented and experimentally studied. • MDACWH has high performance on making domestic hot water and air conditioning. • The time for heating water reduced to 22.0 min after modification. • Average COP reached 4.32, which was 1.58 times higher than the unmodified unit. - Abstract: The recovery of condenser heat is concerned one of the most effective methods to curb energy consumption in residential dwellings. Aiming at recovering the condenser heat of domestic air conditioner, this paper experimentally studied a multi-functional domestic air conditioner with integrated water heater (MDACWH) which can effectively provide space – cooling and domestic hot water simultaneously. The dynamic operation characteristics, such as hot water supply and energy efficiency were tested to verify the availability of the MDACWH. The results showed that the MDACWH can effectively heat the domestic hot water without losing its cooling capacity. It was also found that with the use of MDACWH, the coefficient of comprehensive energy performance of the MDACWH was about 1.58 times higher than that of the unmodified experimental unit. Furthermore, the water-heating time was shorten remarkably from 128.5 min to 22.0 min. The novel domestic air conditioner, compared with the unmodified initial prototype, can be more practical and provide significant energy savings in space-cooling and hot water supply.

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.

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.

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.

Numerical and experimental investigation of thermosyphon solar water heater

International Nuclear Information System (INIS)

Zelzouli, Khaled; Guizani, Amenallah; Kerkeni, Chakib

2014-01-01

Highlights: • We studied a thermosyphon solar water heater composed of high-performance components. • A differential equations solution technique is investigated. • The influences of the collector and storage losses on the system performance were examined. • The storage losses have more influence on the long-term performance. - Abstract: A glassed flat plate collector with selective black chrome coated absorber and a low wall conductance horizontal storage are combined in order to set up a high performance thermosyphon system. Each component is tested separately before testing the complete system in spring days. During the test period, effect of different inlet water temperatures on the collector performance is studied and results have shown that the collector can reach a high efficiency and high outlet water temperature even for elevated inlet water temperatures. Subsequently, long term system performance is estimated by using a developed numerical model. The proposed model, accurate and gave a good agreement with experimental results, allowed to describe the heat transfer in the storage. It has shown also that the long-term performances are strongly influenced by losses from the storage than losses from the collector

75 FR 20111 - Energy Conservation Program: Energy Conservation Standards for Residential Water Heaters, Direct...

Science.gov (United States)

2010-04-16

... Program: Energy Conservation Standards for Residential Water Heaters, Direct Heating Equipment, and Pool... heating equipment and pool heaters. Table I.1--Amended Energy Conservation Standards for Residential Water... for national energy and water conservation; and 7. Other factors the Secretary of Energy (Secretary...

Studi Kinerja Solar Water Heater Dengan Aliran Zig-zag Beralur Balok

Directory of Open Access Journals (Sweden)

M. Rizki Ikhsan

2017-05-01

Full Text Available Solar energy can be used for water heating by using solar water heater application. Therefore, its still needs some modification due to its low efficiency. This modification can be done by replacing the conventional plate of solar collectors into a double plate with a zig-zag pattern. The results shown that along with the decreasing of water flow rates could significantly increase the useful energy (Qu. Initial temperature of water inlet could affect the generated maximum temperature. The highest mean efficiencies of double plate solar water heater with a zig-zag grooved beams pattern of 49.11% was gained in the flow rate of 700 mL / min.

Computational Fluid Dynamics Model for Solar Thermal Storage Tanks with Helical Jacket Heater and Upper Spiral Coil Heater

Energy Technology Data Exchange (ETDEWEB)

Baek, Seung Man [Seoul Nat' l Univ., Seoul (Korea, Republic of); Zhong, Yiming; Nam, Jin Hyun [Daegu Univ., Daegu (Korea, Republic of); Chung, Jae Dong [Sejong Univ., Seoul (Korea, Republic of); Hong, Hiki [Kyung Hee Univ., Seoul (Korea, Republic of)

2013-04-15

In a solar domestic hot water (Shadow) system, solar energy is collected using collector panels, transferred to a circulating heat transfer fluid (brine), and eventually stored in a thermal storage tank (Test) as hot water. In this study, a computational fluid dynamics (CAD) model was developed to predict the solar thermal energy storage in a hybrid type Test equipped with a helical jacket heater (mantle heat exchanger) and an immersed spiral coil heater. The helical jacket heater, which is the brine flow path attached to the side wall of a Test, has advantages including simple system design, low brine flow rate, and enhanced thermal stratification. In addition, the spiral coil heater further enhances the thermal performance and thermal stratification of the Test. The developed model was validated by the good agreement between the CAD results and the experimental results performed with the hybrid-type Test in Shadow settings.

Computational Fluid Dynamics Model for Solar Thermal Storage Tanks with Helical Jacket Heater and Upper Spiral Coil Heater

International Nuclear Information System (INIS)

Baek, Seung Man; Zhong, Yiming; Nam, Jin Hyun; Chung, Jae Dong; Hong, Hiki

2013-01-01

In a solar domestic hot water (Shadow) system, solar energy is collected using collector panels, transferred to a circulating heat transfer fluid (brine), and eventually stored in a thermal storage tank (Test) as hot water. In this study, a computational fluid dynamics (CAD) model was developed to predict the solar thermal energy storage in a hybrid type Test equipped with a helical jacket heater (mantle heat exchanger) and an immersed spiral coil heater. The helical jacket heater, which is the brine flow path attached to the side wall of a Test, has advantages including simple system design, low brine flow rate, and enhanced thermal stratification. In addition, the spiral coil heater further enhances the thermal performance and thermal stratification of the Test. The developed model was validated by the good agreement between the CAD results and the experimental results performed with the hybrid-type Test in Shadow settings

Numerical study on the effects of absorptivity on performance of flat plate solar collector of a water heater

Science.gov (United States)

Tambunan, D. R. S.; Sibagariang, Y. P.; Ambarita, H.; Napitupulu, F. H.; Kawai, H.

2018-03-01

The characteristics of absorber plate of a flat plate solar collector play an important role in the improvement of the performance. In this work, a numerical analysis is carried out to explore the effect of absorptivity and emissivity of absorber plate to the performance of the solar collector of a solar water heater. For a results comparison, a simple a simple solar box cooker with absorber area of 0.835 m × 0.835 m is designed and fabricated. It is employed to heat water in a container by exposing to the solar radiation in Medan city of Indonesia. The transient governing equations are developed. The governing equations are discretized and solved using the forward time step marching technique. The results reveal that the experimental and numerical results show good agreement. The absorptivity of the plate absorber and emissivity of the glass cover strongly affect the performance of the solar collector.

Building America Case Study: Assessment of a Hybrid Retrofit Gas Water Heater

Energy Technology Data Exchange (ETDEWEB)

2017-06-19

This project completed a modeling evaluation of a hybrid gas water heater that combines a reduced capacity tankless unit with a downsized storage tank. This product would meet a significant market need by providing a higher efficiency gas water heater solution for retrofit applications while maintaining compatibility with the half-inch gas lines and standard B vents found in most homes. The TRNSYS simulation tool was used to model a base case 0.60 EF atmospheric gas storage water, a 0.82 EF non-condensing gas tankless water heater, an existing (high capacity) hybrid unit on the market, and an alternative hybrid unit with lower storage volume and reduced gas input requirements. Simulations were completed under a 'peak day' sizing scenario with 183 gpd hot water loads in a Minnesota winter climate case. Full-year simulations were then completed in three climates (ranging from Phoenix to Minneapolis) for three hot water load scenarios (36, 57, and 96 gpd). Model projections indicate that the alternative hybrid offers an average 4.5% efficiency improvement relative to the 0.60 EF gas storage unit across all scenarios modeled. The alternative hybrid water heater evaluated does show promise, but the current low cost of natural gas across much of the country and the relatively small incremental efficiency improvement poses challenges in initially building a market demand for the product.

EXPERIMENTAL INVESTIGATION ON THE PERFORMANCE OF THERMOSYPHON SOLAR WATER HEATER IN THE SOUTH CASPIAN SEA

Directory of Open Access Journals (Sweden)

Abdollah Riahi

2011-01-01

Full Text Available In the present study, a natural circulation closed thermosyphon flat plate solar water heater has been tested at the Faculty of Engineering of University of Mazandaran located in Babol city (36N, 52E. Data were collected for several sunny and cloudy days. Dynamic response of the system to variations in solar insolation was studied and analyzed. It was found that such systems can provide ample energy to satisfy the demand for hot water, contrary to misperception among locals

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.

Experimental performance analysis on a direct-expansion solar-assisted heat pump water heater

International Nuclear Information System (INIS)

Li, Y.W.; Wang, R.Z.; Wu, J.Y.; Xu, Y.X.

2007-01-01

A direct expansion solar assisted heat pump water heater (DX-SAHPWH) experimental set-up is introduced and analyzed. This DX-SAHPWH system mainly consists of 4.20 m 2 direct expansion type collector/evaporator, R-22 rotary-type hermetic compressor with rated input power 0.75 kW, 150 L water tank with immersed 60 m serpentine copper coil and external balance type thermostatic expansion valve. The experimental research under typical spring climate in Shanghai showed that the COP of the DX-SAHPWH system can reach 6.61 when the average temperature of 150 L water is heated from 13.4 deg. C to 50.5 deg. C in 94 min with average ambient temperature 20.6 deg. C and average solar radiation intensity 955 W/m 2 . And the COP of the DX-SAHPWH system is 3.11 even if at a rainy night with average ambient temperature 17.1 deg. C. The seasonal average value of the COP and the collector efficiency was measured as 5.25 and 1.08, respectively. Through exergy analysis for each component of the DX-SAHPWH system, it can be calculated that the highest exergy loss occurs in the compressor, followed by collector/evaporator, condenser and expansion valve, respectively. Further more, some methods are suggested to improve the thermal performance of each component and the whole DX-SAHPWH system

Solar water heaters: possibilities of using in the climatic conditions of the Russia medium area

International Nuclear Information System (INIS)

Popel', O.S.; Frid, S.E.

2001-01-01

On the basis of mathematical simulation of the simplest solar water heating facility using up-to-date software and data of typical meteorological year it was shown that under the real climatic conditions peculiar to Russia central region it is appropriate to use seasonal solar water heaters operating from March up to September. It is shown that to promote solar water heaters in the Russian market one should elaborate engineering approaches and should introduce new materials ensuring reduction of cost of solar water heaters with the availability of high quality and durability [ru

Estimation of cobalt release from feed water heater tubes of BWRs

International Nuclear Information System (INIS)

Uchida, S.; Kitamura, M.; Ozawa, Y.

1983-01-01

To evaluate the release source of cobalt from heater tubes of the feed water line, release rate measurements were carried out by detecting 60 Co released from irradiated stainless steel in contact with neutral water at an oxygen concentration of 20 ppb. The dependences of cobalt release rate on temperature, flow velocity and exposure time were studied after 670 hours of release experiments, and an empirical equation (which is presented) was obtained in the temperature range from 150 to 240 deg C. A decrease in the cobalt release rate above 250 deg C was considered due to the formation of a protective oxide layer. From these data, the amount of cobalt released from individual feed water heaters was evaluated. It was demonstrated that low cobalt containing stainless steel was economically applied only in the higher temperature region of the heater (20% of the total surface) to reduce cobalt feed rate into the reactor (to approx. 1/2). (author)

Study of thermal effects and optical properties of an innovative absorber in integrated collector storage solar water heater

Science.gov (United States)

Taheri, Yaser; Alimardani, Kazem; Ziapour, Behrooz M.

2015-10-01

Solar passive water heaters are potential candidates for enhanced heat transfer. Solar water heaters with an integrated water tank and with the low temperature energy resource are used as the simplest and cheapest recipient devices of the solar energy for heating and supplying hot water in the buildings. The solar thermal performances of one primitive absorber were determined by using both the experimental and the simulation model of it. All materials applied for absorber such as the cover glass, the black colored sands and the V shaped galvanized plate were submerged into the water. The water storage tank was manufactured from galvanized sheet of 0.0015 m in thickness and the effective area of the collector was 0.67 m2. The absorber was installed on a compact solar water heater. The constructed flat-plate collectors were tested outdoors. However the simulation results showed that the absorbers operated near to the gray materials and all experimental results showed that the thermal efficiencies of the collector are over than 70 %.

Pretest thermal analysis of the Tuff Water Migration/In-Situ Heater Experiment

International Nuclear Information System (INIS)

Bulmer, B.M.

1980-02-01

This report describes the pretest thermal analysis for the Tuff Water Migration/In-Situ Heater Experiment to be conducted in welded tuff in G-tunnel, Nevada Test Site. The parametric thermal modeling considers variable boiling temperature, tuff thermal conductivity, tuff emissivity, and heater operating power. For nominal tuff properties, some near field boiling is predicted for realistic operating power. However, the extent of boiling will be strongly determined by the ambient (100% water saturated) rock thermal conductivity. In addition, the thermal response of the heater and of the tuff within the dry-out zone (i.e., bounded by boiling isotherm) is dependent on the temperature variation of rock conductivity as well as the extent of induced boiling

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.

Solar Hot Water Heater

Science.gov (United States)

1978-01-01

The solar panels pictured below, mounted on a Moscow, Idaho home, are part of a domestic hot water heating system capable of providing up to 100 percent of home or small business hot water needs. Produced by Lennox Industries Inc., Marshalltown, Iowa, the panels are commercial versions of a collector co-developed by NASA. In an effort to conserve energy, NASA has installed solar collectors at a number of its own facilities and is conducting research to develop the most efficient systems. Lewis Research Center teamed with Honeywell Inc., Minneapolis, Minnesota to develop the flat plate collector shown. Key to the collector's efficiency is black chrome coating on the plate developed for use on spacecraft solar cells, the coating prevents sun heat from "reradiating," or escaping outward. The design proved the most effective heat absorber among 23 different types of collectors evaluated in a Lewis test program. The Lennox solar domestic hot water heating system has three main components: the array of collectors, a "solar module" (blue unit pictured) and a conventional water heater. A fluid-ethylene glycol and water-is circulated through the collectors to absorb solar heat. The fluid is then piped to a double-walled jacket around a water tank within the solar module.

Exergy Based Performance Analysis of Double Flow Solar Air Heater with Corrugated Absorber

OpenAIRE

S. P. Sharma; Som Nath Saha

2017-01-01

This paper presents the performance, based on exergy analysis of double flow solar air heaters with corrugated and flat plate absorber. A mathematical model of double flow solar air heater based on energy balance equations has been presented and the results obtained have been compared with that of a conventional flat-plate solar air heater. The double flow corrugated absorber solar air heater performs thermally better than the flat plate double flow and conventional flat-plate solar air heate...

Integrated collector storage solar water heater: Temperature stratification

International Nuclear Information System (INIS)

Garnier, C.; Currie, J.; Muneer, T.

2009-01-01

An analysis of the temperature stratification inside an Integrated Collector Storage Solar Water Heater (ICS-SWH) was carried out. The system takes the form of a rectangular-shaped box incorporating the solar collector and storage tank into a single unit and was optimised for simulation in Scottish weather conditions. A 3-month experimental study on the ICS-SWH was undertaken in order to provide empirical data for comparison with the computed results. Using a previously developed macro model; a number of improvements were made. The initial macro model was able to generate corresponding water bulk temperature in the collector with a given hourly incident solar radiation, ambient temperature and inlet water temperature and therefore able to predict ICS-SWH performance. The new model was able to compute the bulk water temperature variation in different SWH collectors for a given aspect ratio and the water temperature along the height of the collector (temperature stratification). Computed longitudinal temperature stratification results obtained were found to be in close agreement with the experimental data.

New Home Buyer Solar Water Heater Trade-Off Study

International Nuclear Information System (INIS)

Symmetrics Marketing Corporation

1999-01-01

This report details the results of a research conducted in 1998 and 1999 and outlines a marketing deployment plan designed for businesses interested in marketing solar water heaters in the new home industry

Acceptability of the integral solar water heater by householders in the low income urban community

CSIR Research Space (South Africa)

Basson, FA

1984-01-01

Full Text Available A research and demonstration project on the use and performance of low cost integral solar water heaters in urban low-income dwellings was carried out in 1982/83. The project involved technical and socio-economic components. This report summarises...

An economic and performance design study of solar preheaters for domestic hot water heaters in North Carolina

Science.gov (United States)

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

1977-01-01

The performance and estimated material costs for several solar preheaters for domestic hot water heaters using isolation levels present in North Carolina are presented. The effects of monthly variations in isolation and the direction of incident radiation are included. Demand is assumed at 13 gallons (49.2 liters) per day per person. The study shows that a closed circulation system with 82 gallons (310 liters) of preheated storage and 53.4 cu ft (4.94 cu m) of collector surface with single cover can be expected to cost about $800 and to repay it capital cost and interest (at 8%) in 5.2 years, assuming present electric rates increase at 5% per year.

Experimental and theoretical investigation of Stirling engine heater: Parametrical optimization

International Nuclear Information System (INIS)

Gheith, R.; Hachem, H.; Aloui, F.; Ben Nasrallah, S.

2015-01-01

Highlights: • A Stirling engine was investigated to optimize its operation and its performance. • The porous medium present the highest amount of heat exchanged in a Stirling engine. • The heater characteristics are determinant points to enhance the thermal exchange in Stirling engine. • All operation parameters influence the heater performances. • Thermal and exergy heater efficiencies are sensible to temperature and pressure. - Abstract: The aim of this work is to optimize γ Stirling engine performances with a special care given to the heater. This latter consists of 20 tubes in order to increase the exchange area between the working gas and the hot source. Different parameters were chosen to evaluate numerically and experimentally the heater. The selected four independent parameters are: heating temperature (300–500 °C), initial filling pressure (3–8 bar), cooling water flow rate (0.2–3 l/min) and frequency (2–7 Hz). The amount of energy exchanged in the heater is significantly influenced by the frequency and heating temperature but it is slightly enhanced with the increase in the cooling water flow rate. The thermal and the exergy efficiencies of the heater are very sensible to the temperature and pressure variations.

CFD Study of Fluid Flow in an All-glass Evacuated Tube Solar Water Heater

DEFF Research Database (Denmark)

Ai, Ning; Fan, Jianhua; Li, Yumin

2008-01-01

Abstract: The all-glass evacuated tube solar water heater is one of the most widely used solar thermal technologies. The aim of the paper is to investigate fluid flow in the solar water heater by means of computational fluid dynamics (CFD). The investigation was carried out with a focus on the co...... for future system optimization....

Consumers and experts. An econometric analysis of the demand for water heaters

International Nuclear Information System (INIS)

Van Soest, A.; Bartels, R.; Fiebig, D.G.

2003-01-01

Consumers can accumulate product information on the basis of a combination of searching, product advertising and expert advice. Examples of experts who provide product information include doctors advising patients on treatments, motor mechanics diagnosing car problems and recommending repairs, accountants recommending investment strategies, and plumbers making recommendations on alternative water heaters. In each of these examples, the transactions involve the sale of goods and services where the seller is at the same time an expert providing advice on the amount and type of product or service to be purchased. In the case of water heaters, the plumber advising a consumer on their choice of water heater will most likely also install the appliance. Because of the information asymmetry there is potentially a strategic element in the transmission of information from expert to consumer. This paper reports on an econometric investigation of the factors that determine the choices made by consumers and the recommendations made by plumbers and the extent to which plumbers act in the best interests of their customers. The empirical work is made possible by the availability of stated preference data generated by designed experiments involving separate samples of Australian consumers and plumbers. We find some evidence that plumbers have higher preferences than consumers for heater characteristics that increase their profit margin

Experimental performance analysis and optimization of a direct expansion solar-assisted heat pump water heater

International Nuclear Information System (INIS)

Li, Y.W.; Wang, R.Z.; Wu, J.Y.; Xu, Y.X.

2007-01-01

In this study, a direct expansion solar-assisted heat pump water heater (DX-SAHPWH) with rated input power 750 W was tested and analyzed. Through experimental research in spring and thermodynamics analysis about the system performance, some suggestions for the system optimization are proposed. Then, a small-type DX-SAHPWH with rated input power 400 W was built, tested and analyzed. Through exergy analysis for each component of DX-SAHPWH (A) and (B), it can be seen that the highest exergy loss occurs in the compressor and collector/evaporator, followed by the condenser and expansion valve, respectively. Furthermore, some methods are suggested to improve the performance of each component, especially the collector/evaporator. A methodology for the design optimization of the collector/evaporator was introduced and applied. In order to maintain a proper matching between the heat pumping capacity of the compressor and the evaporative capacity of the collector/evaporator under widely varying ambient conditions, the electronic expansion valve and variable frequency compressor are suggested to be utilized for the DX-SAHPWH

Solar water heaters in China: A new day dawning

NARCIS (Netherlands)

Han, Jingyi; Mol, A.P.J.; Lu, Y.

2010-01-01

Solar thermal utilization, especially the application of solar water heater technology, has developed rapidly in China in recent decades. Manufacturing and marketing developments have been especially strong in provinces such as Zhejiang, Shandong and Jiangsu. This paper takes Zhejiang, a relatively

Feed-water heaters alternative design comparison; Comparacion de disenos alternativos de calentadores

Energy Technology Data Exchange (ETDEWEB)

Torres Toledano, Gerardo [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

1988-12-31

A procedure is presented for the alternative design comparison of feed water heaters, based in the failure records of damaged tubes during operation. The procedure is used for cases in which non-continuous or random inspections are made to the feed-water heaters. [Espanol] Se presenta un procedimiento para comparar disenos alternativos de calentadores, basandose en los registros de fallas de los tubos rotos acumuladas durante su operacion. El procedimiento se emplea para casos en los que se realizan inspecciones a los calentadores no continuas, ya sea periodicas o al azar.

Feed water pre-heater with two steam spaces

International Nuclear Information System (INIS)

Tratz, H.; Kelp, F.; Netsch, E.

1976-01-01

A feed water pre-heater for the two stage heating of feed water by condensing steam, having a low installed height is described, which can be installed in the steam ducts of turbines of large output, as in LWRs in nuclear power stations. The inner steam space is closed on one side by the water vessel, while the tubes of the inner steam space go straight from the water vessel, and the tubes of the outer steam space are bent into a U shape and open out into the water vessel. The two-stage preheater is thus surrounded by feedwater in two ways. (UWI) [de

Effect of Collector Aspect Ratio on the Thermal Performance of Wavy Finned Absorber Solar Air Heater

OpenAIRE

Abhishek Priyam; Prabha Chand

2016-01-01

A theoretical investigation on the effect of collector aspect ratio on the thermal performance of wavy finned absorber solar air heaters has been performed. For the constant collector area, the various performance parameters have been calculated for plane and wavy finned solar air heaters. It has been found that the performance of wavy finned solar air heater improved with the increase in the collector aspect ratio. The performance of wavy finned solar air heater has been found 30 percent hig...

DEVELOPMENT AND PRELIMINARY TESTING OF A PARABOLIC TROUGH SOLAR WATER HEATER

Directory of Open Access Journals (Sweden)

O. A. Lasode

2011-06-01

Full Text Available Solar energy is a high-temperature, high-energy radiant energy source, with tremendous advantages over other alternative energy sources. It is a reliable, robust renewable resource which is largely undeveloped. The design and fabrication of parabolic trough solar water heater for water heating was executed. The procedure employed includes the design, construction and testing stages. The equipment which is made up of the reflector surface (curved mirror, reflector support, absorber pipe and a stand was fabricated using locally sourced materials. The results obtained. compared favourably with other research works in the literature. It depicts that employing a suitable design, selection of time of heating and proper focusing of the reflected rays to the focal spot region, solar radiation can efficiently be utilized for water heating in a tropical environment. This work presents a parabolic trough solar water heater as a suitable renewable energy technology for reducing water-heating costs.

A parametric study on a humidification–dehumidification (HDH) desalination unit powered by solar air and water heaters

International Nuclear Information System (INIS)

Yıldırım, Cihan; Solmuş, İsmail

2014-01-01

Highlights: • A time dependent humidification–dehumidification desalination process is investigated. • Fourth-order Runge–Kutta method is used to simulate the problem. • Daily and annual performance are examined. • Various operational parameters are investigated. - Abstract: The performance of a solar powered humidification–dehumidification desalination system is theoretically investigated for various operating and design parameters of the system under climatological conditions of Antalya, Turkey. The primary components of the system are a flat plate solar water heater, a flat plate double pass solar air heater, a humidifier, a dehumidifier and a storage tank. The mathematical model of the system is developed and governing conservation equations are numerically solved by using the Fourth order Runge–Kutta method. Daily and annual yields are calculated for different configurations of the system such as only water heating, only air heating and water–air heating

Radiative heat transfer analysis in pure water heater used for semiconductor processing

International Nuclear Information System (INIS)

Liu, L.H.; Kudo, K.; Mochida, A.; Ogawa, T.; Kadotani, K.

2004-01-01

A simplified one-dimensional model is presented to analyze the non-gray radiative transfer in pure water heater used in the rinsing processes within semiconductor production lines, and the ray-tracing method is extended to simulate the radiative heat transfer. To examine the accuracy of the simplified model, the distribution of radiation absorption is determined by the ray-tracing method based the simplified model and compared with the data obtained by three-dimensional non-gray model in combination with Monte Carlo method in reference, and the effects of the water thickness on the radiation absorption are analyzed. The results show that the simplified model has a good accuracy in solving the radiation absorption in the pure water heater. The radiation absorption increases with the water thickness, but when the water thickness is greater than 50 mm, the radiation absorption increases very slowly with the water thickness

Pengaruh Pelat Penyerap Ganda Model Gelombang dengan Penambahan Reflector terhadap Kinerja Solar Water Heater Sederhana

OpenAIRE

Ismail, Nova Risdiyanto

2011-01-01

Telah banyak dilakukan USAha meningkatkan kinerja solar water heater diantaranya modifikasi pelat penyerap tunggal menjadi ganda, modifikasi aliran untuk meningkatkan penyerapan panas, modifikasi material dan pelat penyerap ganda model gelombang. Penelitian ini bertujuan untuk mengetahui pengaruh pelat penyerap ganda model gelombang dengan penambahan reflector terhadap kinerja solar water heater sederhana. Dalam penelitian ini dilakukan secara eksperimen, untuk embandingkan kinerja pelat pen...

76 FR 63211 - Energy Efficiency Program: Test Procedures for Residential Water Heaters, Direct Heating...

Science.gov (United States)

2011-10-12

... DEPARTMENT OF ENERGY 10 CFR Part 430 [Docket Number EERE-2011-BT-TP-0042] RIN 1904-AC53 Energy Efficiency Program: Test Procedures for Residential Water Heaters, Direct Heating Equipment, and Pool Heaters AGENCY: Office of Energy Efficiency and Renewable Energy, Department of Energy. ACTION: Request for...

Thermo-hydraulic performance enhancement of solar air heater ...

African Journals Online (AJOL)

DR OKE

Keywords: Solar air heater; Nusselt number; thermal efficiency; multiple arcs with ... loss; and one or two covers of glass or transparent plastic provide resistance to ..... Methods of testing to determine the thermal performance of solar collectors.

Temperature distributions in trapezoidal built in storage solar water heaters with/without phase change materials

International Nuclear Information System (INIS)

Tarhan, Sefa; Sari, Ahmet; Yardim, M. Hakan

2006-01-01

Built in storage solar water heaters (BSSWHs) have been recognized for their more compact constructions and faster solar gain than conventional solar water heaters, however, their water temperatures quickly go down during the cooling period. A trapezoidal BSSWH without PCM storage unit was used as the control heater (reference) to investigate the effect of two differently configured PCM storage units on the temperature distributions in water tanks. In the first design, myristic acid was filled into the PCM storage tank, which also served as an absorbing plate. In the second design, lauric acid was filled into the PCM storage tank, which also served as a baffle plate. The water temperature changes were followed by five thermocouples placed evenly and longitudinally into each of the three BSSWHs. The effects of the PCMs on the water temperature distributions depended on the configuration of the PCM storage unit and the longitudinal position in the water tanks. The use of lauric acid lowered the values of the peak temperatures by 15% compared to the control heater at the upper portion of the water tanks because of the low melting temperature of lauric acid, but it did not have any consistent effect on the retention of the water temperatures during the cooling period. The ability of the myristic acid storage unit to retain the water temperatures got more remarkable, especially at the middle portion of the water tank. The myristic acid storage increased the dip temperatures by approximately 8.8% compared to the control heater. In conclusion, lauric acid storage can be used to stabilize the water temperature during the day time, while the myristic acid storage unit can be used as a thermal barrier against heat loss during the night time because of its relatively high melting temperature and low heat conduction coefficient in its solid phase. The experimental results have also indicated that the thermal characteristics of the PCM and the configuration of the PCM storage

NORTH PORTAL - WATER HEATER CALCULATION - CHANGE HOUSE FACILITY No.5008

International Nuclear Information System (INIS)

R.B. Blackstone

1996-01-01

The purpose of this design analysis and calculation is to determine the demand for hot water in the Change House Facility and the selection of a water heater of appropriate size in accordance with the Uniform Plumbing Code (Section 4.4.1) and U.S. Department of Energy Order 6430.1A-1540 (Section 4.4.2)

10 CFR 431.106 - Uniform test method for the measurement of energy efficiency of commercial water heaters and hot...

Science.gov (United States)

2010-01-01

... efficiency of commercial water heaters and hot water supply boilers (other than commercial heat pump water... PROGRAM FOR CERTAIN COMMERCIAL AND INDUSTRIAL EQUIPMENT Commercial Water Heaters, Hot Water Supply Boilers and Unfired Hot Water Storage Tanks Test Procedures § 431.106 Uniform test method for the measurement...

Exergy Analysis of Serpentine Thermosyphon Solar Water Heater

Directory of Open Access Journals (Sweden)

Muhammad Faisal Hasan

2018-03-01

Full Text Available The performance of a solar hot water system is assessed for heat pump and domestic heating applications. Thermodynamic analysis on a serpentine-type thermosyphon flat-plate solar heater is conducted using the Second Law of thermodynamics. Exergetic optimization is first performed to determine the parameters for the maximum exergy efficiency using MATLAB optimization toolbox. Geometric parameters (collector surface area, dimensions, and pipe diameter, optical parameters (transmittance absorptance product, ambient temperature, solar irradiation and operating parameters (mass flow rate, fluid temperature, and overall heat transfer (loss coefficient are accounted for in the optimization scheme. The exergy efficiency at optimum condition is found to be 3.72%. The results are validated using experimental data and found to be in good agreement. The analysis is further extended to the influence of various operating parameters on the exergetic efficiency. It is observed that optical and thermal exergy losses contribute almost 20%, whereas approximately 77% exergy destruction is contributed by the thermal energy conversion. Exergy destruction due to pressure drop is found negligible. The result of this analysis can be used for designing and optimization of domestic heat pump system and hot water application.

热泵与家用太阳热水器联合供热性能试验%Performance jointly test of heat pump water heater with household solar heating

Institute of Scientific and Technical Information of China (English)

谌学先; 高文峰; 兰青; 唐润生; 夏朝凤

2011-01-01

为解决家用太阳能热水器供热的间歇性和不稳定性,应用热泵辅助可达到全天候供热,该文通过对这种联合供热系统的供热性能和运行性能进行了测试,并对热水器的升温、保温和热泵的加热进行了试验和分析,结果表明:空气源热泵辅助型真空管家用太阳热水系统仅在累积太阳辐照量小于14 MJ/m2时,需要空气源热泵辅助加热,总制热性能系数可达6.18.%To solve the problems of heating intermittent and instability for household solar water heater, application of heat pump for evacuated tube solar water heater system can achieved auxiliary heat supply round-the-clock. Heating performance test and operation of the system were conducted and the temperature rise performance, heat preservation of the solar water heater system and the heating performance of heat pump were tested and analyzed in this paper. The result showed that when the solar radiation was less than 14 MJ/m2 , the system needed heating by air source heat pump,on this occasion, the system total coefficient of performance could reach 6.18.

75 FR 21981 - Energy Conservation Program: Energy Conservation Standards for Residential Water Heaters, Direct...

Science.gov (United States)

2010-04-27

... DEPARTMENT OF ENERGY 10 CFR Part 430 [Docket Number EE-2006-BT-STD-0129] RIN 1904-AA90 Energy Conservation Program: Energy Conservation Standards for Residential Water Heaters, Direct Heating Equipment, and Pool Heaters Correction In rule document 2010-7611 beginning on page 20112 in the issue of Friday...

Effect of Fuel Wobbe Number on Pollutant Emissions from Advanced Technology Residential Water Heaters: Results of Controlled Experiments

Energy Technology Data Exchange (ETDEWEB)

Rapp, Vi H.; Singer, Brett C.

2014-03-01

The research summarized in this report is part of a larger effort to evaluate the potential air quality impacts of using liquefied natural gas in California. A difference of potential importance between many liquefied natural gas blends and the natural gas blends that have been distributed in California in recent years is the higher Wobbe number of liquefied natural gas. Wobbe number is a measure of the energy delivery rate for appliances that use orifice- or pressure-based fuel metering. The effect of Wobbe number on pollutant emissions from residential water heaters was evaluated in controlled experiments. Experiments were conducted on eight storage water heaters, including five with “ultra low-NO{sub X}” burners, and four on-demand (tankless) water heaters, all of which featured ultra low-NO{sub X} burners. Pollutant emissions were quantified as air-free concentrations in the appliance flue and fuel-based emission factors in units of nanogram of pollutant emitter per joule of fuel energy consumed. Emissions were measured for carbon monoxide (CO), nitrogen oxides (NO{sub X}), nitrogen oxide (NO), formaldehyde and acetaldehyde as the water heaters were operated through defined operating cycles using fuels with varying Wobbe number. The reference fuel was Northern California line gas with Wobbe number ranging from 1344 to 1365. Test fuels had Wobbe numbers of 1360, 1390 and 1420. The most prominent finding was an increase in NO{sub X} emissions with increasing Wobbe number: all five of the ultra low-NO{sub X} storage water heaters and two of the four ultra low-NO{sub X} on-demand water heaters had statistically discernible (p<0.10) increases in NO{sub X} with fuel Wobbe number. The largest percentage increases occurred for the ultra low-NO{sub X} water heaters. There was a discernible change in CO emissions with Wobbe number for all four of the on-demand devices tested. The on-demand water heater with the highest CO emissions also had the largest CO increase

NORTH PORTAL-WATER HEATER CALCULATION-SHOP BUILDING No. 5006

International Nuclear Information System (INIS)

R. Blackstone

1996-01-01

The purpose of this design analysis and calculation is to determine the demand for hot and the selection of a water heater of appropriate size, in accordance with the Uniform Plumbing Code (Section 4.4.1) and U.S. Department of Energy Order 6430.1A-1540 (Section 4.4.2)

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).

Performance test for a solar water heater

Science.gov (United States)

1979-01-01

Two reports describe procedures and results of performance tests on domestic solar powered hot water system. Performance tests determine amount of energy collected by system, amount of energy delivered to solar source, power required to operate system and maintain proper tank temperature, overall system efficiency, and temperature distribution in tank.

The Energy Efficiency of Hot Water Production by Gas Water Heaters with a Combustion Chamber Sealed with Respect to the Room

Directory of Open Access Journals (Sweden)

Grzegorz Czerski

2014-08-01

Full Text Available This paper presents investigative results of the energy efficiency of hot water production for sanitary uses by means of gas-fired water heaters with the combustion chamber sealed with respect to the room in single-family houses and multi-story buildings. Additionally, calculations were made of the influence of pre-heating the air for combustion in the chimney and air supply system on the energy efficiency of hot water production. CFD (Computational Fluid Dynamics software was used for calculation of the heat exchange in this kind of system. The studies and calculations have shown that the use of gas water heaters with a combustion chamber sealed with respect to the room significantly increases the efficiency of hot water production when compared to traditional heaters. It has also been proven that the pre-heating of combustion air in concentric chimney and air supply ducts essentially improves the energy efficiency of gas appliances for hot water production.

Assessment of the environmental impacts deriving from the life cycle of a typical solar water heater

Directory of Open Access Journals (Sweden)

G. Gaidajis

2014-01-01

Full Text Available According to life cycle thinking, the environmental burden deriving from different life cycle stages of a product or a system, such as manufacturing, transportation, maintenance and landfilling should be taken into consideration while assessing its environmental performance. In that aspect, the environmental impacts deriving from the life cycle of a typical solar water heater (SWH in Greece are analyzed and assessed with the application of relative life cycle assessment (LCA software in this study. In order to examine various impact categories such as global warming, ozone layer depletion, ecotoxicity and so forth, the IMPACT2002+ method is applied. The aim of this study is to examine the life cycle stages, processes and materials that significantly affect the system under examination and to provide a discussion regarding the environmental friendliness of solar water heaters.

Scheduling of Domestic Water Heater Power Demand for Maximizing PV Self-Consumption Using Model Predictive Control

DEFF Research Database (Denmark)

Sossan, Fabrizio; Kosek, Anna Magdalena; Martinenas, Sergejus

2013-01-01

This paper presents a model predictive control (MPC) strategy for maximizing photo-voltaic (PV) selfconsumption in a household context exploiting the flexible demand of an electric water heater. The predictive controller uses a water heater model and forecast of the hot Water consumption in order...... to predict the future temperature of the water and it manages its state (on and off) according to the forecasted PV production, which are computed starting from forecast of the solar irradiance. Simulations for the proof of concept and for validating the proposed control strategy are proposed. Results...... of the control approach are compared with a traditional thermostatic controller using historical measurements of a 10 kW PV installation. Economic results based on the Italian self consumption tariffs are also reported. The model of the water heater complex is a mixed grey and white box and its parameters have...

Feedwater heater

International Nuclear Information System (INIS)

Murata, Shigeto; Minato, Akihiko; Yokomizo, Osamu; Masuhara, Yasuhiro.

1991-01-01

The present invention concerns a feedwater heater for a BWR type reactor. A cylinder is fit into the lower portion of a drain inlet pipe, to which drain water inflows from a turbine, and a disk is disposed to the lower end of the cylinder vertically to the axis of the cylinder, to constitute a drain water dispersing mechanism. Drain water inflown from the drain inlet pipe is fallen in the cylinder and collides against the disk. The collided drain water is splashed horizontally by its kinetic energy to reach the heat transfer pipe and conducts heat exchange. In this case, the drain water is converted into fine droplets by the collision against the disk and scattered in a wide range in the heater. As a result, sensible heat in the drain water can be transferred to feedwater effectively. Then, even the heat energy of the drain water can be utilized effectively for heat exchange, to improve the heat exchange efficiency. (I.N.)

Design and performance of low-wattage electrical heater probe

International Nuclear Information System (INIS)

Biddle, R.; Wetzel, J.R.; Cech, R.

1997-01-01

A mound electrical calibration heater (MECH) has been used in several EG and G Mound developed calorimeters as a calibration tool. They are very useful over the wattage range of a few to 500 W. At the lower end of the range, a bias develops between the MECH probe and calibrated heat standards. A low-wattage electrical calibration heater (L WECH) probe is being developed by the Safeguards Science and Technology group (NIS-5) of Los Alamos National Laboratory based upon a concept proposed by EG and G Mound personnel. The probe combines electrical resistive heating and laser-light powered heating. The LWECH probe is being developed for use with power settings up to 2W. The electrical heater will be used at the high end of the range, and laser-light power will be used low end of the wattage range. The system consists of two components: the heater probe and a control unit. The probe is inserted into the measuring cavity through an opening in the insulating baffle, and a sleeve is required to adapt to the measuring chamber. The probe is powered and controlled using electronics modules located separately. This paper will report on the design of the LWECH probe, initial tests, and expected performance

An experimental investigation with artificial sunlight of a solar hot-water heater

Science.gov (United States)

Simon, F. F.

1976-01-01

Thermal performance measurements were made of a commercial solar hot water heater in a solar simulator to determine basic performance characteristics of a traditional type of flat plate collector, with and without side reflectors (to increase the solar flux). Information on each of the following was obtained; (1) the effect of flow and incidence angle on the efficiency of a flat plate collector (but only without side reflectors); (2) transient performance under flow and nonflow conditions; (3) the effectiveness of reflectors to increase collector efficiency for a zero radiation angle at fluid temperatures required for solar air conditioning; and (4) the limits of applicability of a collector efficiency correlation based on the Hottel Whillier equation.

16 CFR Appendix D2 to Part 305 - Water Heaters-Electric

Science.gov (United States)

2010-01-01

... 16 Commercial Practices 1 2010-01-01 2010-01-01 false Water Heaters-Electric D2 Appendix D2 to... PRODUCTS REQUIRED UNDER THE ENERGY POLICY AND CONSERVATION ACT (âAPPLIANCE LABELING RULEâ) Pt. 305, App. D2 Appendix D2 to Part 305—Water Heaters—Electric Range Information CAPACITY FIRST HOUR RATING Range of...

14 CFR 23.859 - Combustion heater fire protection.

Science.gov (United States)

2010-01-01

... relief of any backfire that, if so restricted, could cause heater failure. (d) Heater controls: general. Provision must be made to prevent the hazardous accumulation of water or ice on or in any heater control... heater in case of leakage. (2) The region surrounding the heater, if the heater fuel system has fittings...

Observation of convection phenomenon by high-performance transparent heater based on Pt-decorated Ni micromesh

Directory of Open Access Journals (Sweden)

Han-Jung Kim

2017-02-01

Full Text Available In this study, we report for the first time on the convection phenomenon for the consistent and sensitive detection of target materials (particulate matter (PM or gases with a high-performance transparent heater. The high-performance transparent heater, based on Pt-decorated Ni micromesh, was fabricated by a combination of transfer printing process and Pt sputtering. The resulting transparent heater exhibited excellent mechanical durability, adhesion with substrates, flexibility, and heat-generating performance. We monitored the changes in the PM concentration and temperature in an airtight chamber while operating the heater. The temperature in the chamber was increased slightly, and the PM2.5 concentration was increased by approximately 50 times relative to the initial state which PM is deposed in the chamber. We anticipate that our experimental findings will aid in the development and application of heaters for sensors and actuators as well as transparent electrodes and heating devices.

Marketing and promoting solar water heaters to home builders

Energy Technology Data Exchange (ETDEWEB)

Keller, C.; Ghent, P.

1999-12-06

This is the final report of a four-task project to develop a marketing plan designed for businesses interested in marketing solar water heaters in the new home industry. This report outlines suggested marketing communication materials and other promotional tools focused on selling products to the new home builder. Information relevant to promoting products to the new home buyer is also included.

Electrochemical corrosion protection of storage water heaters in the building services; Elektrochemischer Korrosionsschutz von Speicher-Wassererwaermern in der Gebaeudetechnik

Energy Technology Data Exchange (ETDEWEB)

Bytyn, Wilfried [MAGONTEC GmbH, Bottrop (Germany)

2012-06-15

Storage water heaters currently experience a new consideration as a central thermal energy storage with an energy buffer characteristics. The contribution under consideration presents the principles and conditions of use for the cathodic corrosion protection of storage water heaters.

Studi Kinerja Solar Water Heater Dengan Aliran Zig-zag Beralur Balok

OpenAIRE

Ikhsan, M. Rizki; Soeparman, Sudjito; Sasongko, Mega Nur

2017-01-01

Solar energy can be used for water heating by using solar water heater application. Therefore, its still needs some modification due to its low efficiency. This modification can be done by replacing the conventional plate of solar collectors into a double plate with a zig-zag pattern. The results shown that along with the decreasing of water flow rates could significantly increase the useful energy (Qu). Initial temperature of water inlet could affect the generated maximum temperature. The hi...

14 CFR 25.859 - Combustion heater fire protection.

Science.gov (United States)

2010-01-01

..., could cause heater failure. (d) Heater controls; general. Provision must be made to prevent the hazardous accumulation of water or ice on or in any heater control component, control system tubing, or... leakage. (2) The region surrounding the heater, if the heater fuel system has fittings that, if they...

Performance Study of Solar Air Heater Having Absorber Plate with Half-Perforated Baffles

OpenAIRE

Maheshwari, B. K.; Karwa, Rajendra; Gharai, S. K.

2011-01-01

The paper presents a detailed mathematical model for performance prediction of a smooth duct solar air heater validated against the experimental results. Experimental study on a solar air heater having absorber plate with half-perforated baffles on the air flow side shows thermal efficiency enhancement of 28%–45% over that of the smooth duct solar air heater, which is attributed to the heat transfer enhancement (of the order of 180%–235%) due to the perforated baffles attached to the absorber...

Measure Guideline. Heat Pump Water Heaters in New and Existing Homes

Energy Technology Data Exchange (ETDEWEB)

Shapiro, Carl [Consortium for Advanced Residential Buildings (CARB), Norwalk, CT (United States); Puttagunta, Srikanth [Consortium for Advanced Residential Buildings (CARB), Norwalk, CT (United States); Owens, Douglas [Consortium for Advanced Residential Buildings (CARB), Norwalk, CT (United States)

2012-02-01

This Building America Measure Guideline is intended for builders, contractors, homeowners, and policy-makers. This document is intended to explore the issues surrounding heat pump water heaters (HPWHs) to ensure that homeowners and contractors have the tools needed to appropriately and efficiently install HPWHs

Numerical analysis of using hybrid photovoltaic-thermal solar water heater in Iran

Directory of Open Access Journals (Sweden)

M Mohammadi Sarduei

2017-05-01

Full Text Available Introduction Electrical performance of solar cells decreases with increasing cell temperature, basically because of growth of the internal charge carrier recombination rates, caused by increased carrier concentrations. Hybrid Photovoltaic/thermal (PVT systems produce electrical and thermal energy simultaneously. PVT solar collectors convert the heat generated in the solar cells to low temperature useful heat energy and so they provide a lower working temperature for solar cells which subsequently leads to a higher electrical efficiency. Recently, in Iran, the reforming government policy in subsidy and increasing fossil fuels price led to growing an interest in use of renewable energies for residual and industrial applications. In spite of this, the PV power generator investment is not economically feasible, so far. Hybrid PVT devices are well known as an alternative method to improve energy performance and therefore economic feasibility of the conventional PV systems. The aim of this study is to investigate the performance of a PVT solar water heater in four different cities of Iran using TRNSYS program. Materials and Methods The designed PVT solar water system consists of two separate water flow circuits namely closed cycle and open circuit. The closed cycle circuit was comprised of a solar PVT collector (with nominal power of 880 W and area of 5.6 m2, a heat exchanger in the tank (with volume of 300 L, a pump and connecting pipes. The water stream in the collector absorbs the heat accumulated in the solar cells and delivers it to the water in the tank though the heat exchanger. An on/off controller system was used to activate the pump when the collector outlet temperature was higher than that of the tank in the closed cycle circuit. The water in the open circuit, comes from city water at low temperature, enters in the lower part of the storage tank where the heat transfer occurs between the two separate circuits. An auxiliary heater, connected

Assessment of radioisotope heaters for remote terrestrial applications

International Nuclear Information System (INIS)

Uherka, K.L.

1987-05-01

This paper examines the feasibility of using radioisotope byproducts for special heating applications at remote sites in Alaska and other cold regions. The investigation included assessment of candidate radioisotope materials for heater applications, identification of the most promising cold region applications, evaluation of key technical issues and implementation constraints, and development of conceptual heater designs for candidate applications. Strontium-90 (Sr-90) was selected as the most viable fuel for radioisotopic heaters used in terrestrial applications. Opportunities for the application of radioisotopic heaters were determined through site visits to representative Alaska installations. Candidate heater applications included water storage tanks, sludge digesters, sewage lagoons, water piping systems, well-head pumping stations, emergency shelters, and fuel storage tank deicers. Radioisotopic heaters for water storage tank freeze-up protection and for enhancement of biological waste treatment processes at remote sites were selected as the most promising applications

16 CFR Appendix D5 to Part 305 - Water Heaters-Heat Pump

Science.gov (United States)

2010-01-01

... 16 Commercial Practices 1 2010-01-01 2010-01-01 false Water Heaters-Heat Pump D5 Appendix D5 to Part 305 Commercial Practices FEDERAL TRADE COMMISSION REGULATIONS UNDER SPECIFIC ACTS OF CONGRESS RULE... Appendix D5 to Part 305—Water Heaters—Heat Pump Range Information CAPACITY FIRST HOUR RATING Range of...

EFFICIENCY OF THE CAPACITY-TYPE SOLAR WATER HEATER WITH THE FLEXIBLE POLYMER ABSORBER.

Directory of Open Access Journals (Sweden)

Ermuratschii V.V.

2008-08-01

Full Text Available Energetic indexes of solar capacity-type water heaters with flexible polymer absorbers and different constructions of enclosures using the refined method of calculus were obtained.

Study on the selection method of feed water heater safety valves in nuclear power plants

International Nuclear Information System (INIS)

Shi Jianzhong; Huang Chao; Hu Youqing

2014-01-01

The selection of the high pressure feedwater heater's safety valve usually follows the principle recommended by HEI standards in thermal power plant. However, the nuclear power plant's heaters generally need to accept a lots of drain from a moisture separator reheater (MSR). When the drain regulating valve was failure in fully open position, a large number of high pressure steam will directly goes into the heater. It make high-pressure heater have a risk of overpressure. Therefore, the safety valve selection of the heaters for nuclear power plants not only need to follow the HEI standards, but also need to check his capacity in certain special conditions. The paper established a calculation method to determine the static running point of the heaters based on characteristic equations of the feed water heater, drain regulating valve and steam extraction pipings, and energy balance principle. The method can be used to calculate the equilibrium pressure of various special running conditions, so further determine whether the capacity of the safety valve meets the requirements of safety and emissions. The method proposed in this paper not only can be used for nuclear power plants, can also be used for thermal power plants. (authors)

Experimental investigation of a Hybrid Solar Drier and Water Heater System

International Nuclear Information System (INIS)

Mohajer, Alireza; Nematollahi, Omid; Joybari, Mahmood Mastani; Hashemi, Seyed Ahmad; Assari, Mohammad Reza

2013-01-01

Highlights: • A Hybrid Solar Drier and Water Heater System experimentally investigated. • Using collected data, GIS maps were plotted for solar energy of Khuzestan Province. • System is presented which facilitates a dual-purpose solar collector. • The system includes a 100 l water storage tank, a solar dryer with 5 trays. • Experiments were carried out to dry vegetables (parsley, dill and coriander). - Abstract: Drying process is of great importance in food industries. One of the best methods of food drying is using solar dryers. For initial estimation of solar energy, calculations were made for statistical information measured by Renewable Energy Organization of Iran. Using collected data, GIS maps were plotted for solar energy of Khuzestan Province, Iran. In this study, a new hybrid system is presented which facilitates a dual-purpose solar collector to simultaneously support a dryer system and provide consumptive hot water. The system includes a 100 l water storage tank, a solar dryer with 5 trays, and a dual-purpose collector. Experiments were carried out to dry a mixture of vegetables (parsley, dill and coriander) at constant air and water flow rates. Besides, an electrical heater has been used as an auxiliary source for heating. The results indicated that the system optimally dried the vegetables and simultaneously provided the consumptive hot water

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.

Dimensioning of a solar water heater made from PET bottles; Dimensionamento de um aquecedor solar de agua feito com garrafas PET

Energy Technology Data Exchange (ETDEWEB)

Bertoleti, Pedro Henrique Fonseca; Souza, Teofilo Miguel de [Universidade Estadual Paulista (UNESP), Guaratingueta, SP (Brazil). Centro de Energias Renovaveis

2008-07-01

This document show the solar water heater made of PET bottles, a simple-construction solar water heater that try to give us two important solutions, water heating using solar energy and reutilization of the PET bottles left in the nature. Also, it will be showed how to do the dimensioning of it. Based on the showed dimensioning a application / software is developed and after that simulations are made using the application to provide how is the economy if it's used this kind of solar water heater and their environmental contribution by reutilization of the PET bottles abandoned in the nature. For example, in a common home the economy is about 45% of the electricity bill considering that the warmed water is used just to take a shower. So, the conclusion is: the solar water heater made by PET bottles is a very relevant equipment to the use of the solar energy, to useful applications and environmental contribution. (author)

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.

即热式热水器的界定和安全隐患%Definition and Safety Risks of Instantaneous Water Heaters

Institute of Scientific and Technical Information of China (English)

陈嘉声; 胡晴宇; 沈冬波

2015-01-01

Describe the definition and classification of open-outlet water heater and closed water heater, analysis safety requirements of open-outlet water heater and closed water heater through using and inter-nal structure,Analysis Safety risks caused by the wrong instal ation method.%通过对敞开式热水器和封闭式热水器的定义明确两者的分类和界定，从使用方式和内部结构的角度分析敞开式热水器和封闭式热水器的安全要求，分析错误的安装方式所带来的安全隐患。

Utilization of air conditioner condenser as water heater in an effort to energy conservation

Science.gov (United States)

Sonawan, Hery; Saputro, Panji; Kurniawan, Iden Muhtar

2018-04-01

This paper presents an experimental study of utilization of air conditioner condenser as water heater. Modification of existing air conditioner system is an effort to harvest waste heat energy from condenser. Modification is conducted in order to test the system into two mode tests, first mode with one condenser and second mode with two condensers. Harvesting the waste heat from condenser needs a theoretical and practice study to see how much the AC performance changes if modifications are made. It should also be considered how the technique of harvesting waste heat for water heating purposes. From the problem, this paper presents a comparison between AC performance before and after modification. From the experiment, an increase in compressor power consumption is 4.3% after adding a new condenser. The hot water temperature is attained to 69 °C and ready for warm bath. The increase in power consumption is not too significant compared to the attainable hot water temperature. Also seen that the value of condenser Performance Factor increase from 5.8 to 6.25 or by 7.8%.

14 CFR 29.859 - Combustion heater fire protection.

Science.gov (United States)

2010-01-01

... relief of any backfire that, if so restricted, could cause heater failure. (d) Heater controls; general. There must be means to prevent the hazardous accumulation of water or ice on or in any heater control... malfunctioning; or (ii) Allow flammable fluids or vapors to reach the heater in case of leakage. (2) Each part of...

Performance of a new solar air heater with packed-bed latent storage energy for nocturnal use

International Nuclear Information System (INIS)

Bouadila, Salwa; Kooli, Sami; Lazaar, Mariem; Skouri, Safa; Farhat, Abdelhamid

2013-01-01

Highlights: • A new solar air heater collector using a phase change material. • Experimental study of the new solar air heater collector with latent storage. • Energy and exergy analysis of the solar heater with latent storage collector. • Nocturnal use of solar air heater collector. - Abstract: An experimental study was conducted to evaluate the thermal performance of a new solar air heater collector using a packed bed of spherical capsules with a latent heat storage system. Using both first and second law of thermodynamics, the energetic and exegetic daily efficiencies were calculated in Closed/Opened and Opened cycle mode. The solar energy was stored in the packed bed through the diurnal period and extracted at night. The experimentally obtained results are used to analyze the performance of the system, based on temperature distribution in different localization of the collectors. The daily energy efficiency varied between 32% and 45%. While the daily exergy efficiency varied between 13% and 25%

In-situ tuff water migration/heater experiment: experimental plan

International Nuclear Information System (INIS)

Johnstone, J.K.

1980-08-01

Tuffs on the Nevada Test Site (NTS) are currently under investigation as a potential isolation medium for heat-producing nuclear wastes. The National Academy of Sciences has concurred in our identification of the potentially large water content (less than or equal to 40 vol %) of tuffs as one of the important issues affecting their suitability for a repository. This Experimental Plan describes an in-situ experiment intended as an initial assessment of water generation/migration in response to a thermal input. The experiment will be conducted in the Grouse Canyon Welded Tuff in Tunnel U12g (G-Tunnel) located in the north-central region of the NTS. While the Grouse Canyon Welded Tuff is not a potential repository medium, it has physical, thermal, and mechanical properties very similar to those tuffs currently under consideration and is accessible at depth (400 m below the surface) in an existing facility. Other goals of the experiment are to support computer-code and instrumentation development, and to measure in-situ thermal properties. The experimental array consists of a central electrical heater, 1.2 m long x 10.2 cm diameter, surrounded by three holes for measuring water-migration behavior, two holes for measuring temperature profiles, one hole for measuring thermally induced stress in the rock, and one hole perpendicular to the heater to measure displacement with a laser. This Experimental Plan describes the experimental objectives, the technical issues, the site, the experimental array, thermal and thermomechanical modeling results, the instrumentation, the data-acquisition system, posttest characterization, and the organizational details

Experimental investigation on the performance of an impinging jet solar air heater

Directory of Open Access Journals (Sweden)

T. Rajaseenivasan

2017-03-01

Full Text Available Investigation on an impinging jet solar air heater is performed and reported in this work. The air is supplied through an impinging jet pipe which contains the nozzles to distribute the air in the solar air heater. The air is released from the jet strikes the absorber plate which increases the heat transfer rate by creating turbulent flow in the collector. This study is focused on the parameters that affect the heat transfer characteristics and compared with conventional solar air heater. The system is examined by varying the angle of attack (0°, 10°, 20°, 30°, 60° and 90° and the nozzle diameter (3 mm, 5 mm and 7 mm in the air mass flow rate range of 0.012–0.016 kg/s. The study revealed that the highest performance is achieved with the 30° angle of attack, and the lowest performance is recorded with the 0°. The reduction in jet diameter increases the pressure loss in the collector. The better system performance is observed with the 5 mm diameter hole. The maximum thermal enhancement factor of 2.19 and efficiency of 55.8% are reached with the flow rate of 0.016 kg/s.

Distributed Nonstationary Heat Model of Two-Channel Solar Air Heater

International Nuclear Information System (INIS)

Klychev, Sh. I.; Bakhramov, S. A.; Ismanzhanov, A. I.; Tashiev, N.N.

2011-01-01

An algorithm for a distributed nonstationary heat model of a solar air heater (SAH) with two operating channels is presented. The model makes it possible to determine how the coolant temperature changes with time along the solar air heater channel by considering its main thermal and ambient parameters, as well as variations in efficiency. Examples of calculations are presented. It is shown that the time within which the mean-day efficiency of the solar air heater becomes stable is significantly higher than the time within which the coolant temperature reaches stable values. The model can be used for investigation of the performances of solar water-heating collectors. (authors)

Thermal performance analysis of a flat heat pipe working with carbon nanotube-water nanofluid for cooling of a high heat flux heater

Science.gov (United States)

Arya, A.; Sarafraz, M. M.; Shahmiri, S.; Madani, S. A. H.; Nikkhah, V.; Nakhjavani, S. M.

2018-04-01

Experimental investigation on the thermal performance of a flat heat pipe working with carbon nanotube nanofluid is conducted. It is used for cooling a heater working at high heat flux conditions up to 190 kW/m2. The heat pipe is fabricated from aluminium and is equipped with rectangular fin for efficient cooling of condenser section. Inside the heat pipe, a screen mesh was inserted as a wick structure to facilitate the capillary action of working fluid. Influence of different operating parameters such as heat flux, mass concentration of carbon nanotubes and filling ratio of working fluid on thermal performance of heat pipe and its thermal resistance are investigated. Results showed that with an increase in heat flux, the heat transfer coefficient in evaporator section of the heat pipe increases. For filling ratio, however, there is an optimum value, which was 0.8 for the test heat pipe. In addition, CNT/water enhanced the heat transfer coefficient up to 40% over the deionized water. Carbon nanotubes intensified the thermal performance of wick structure by creating a fouling layer on screen mesh structure, which changes the contact angle of liquid with the surface, intensifying the capillary forces.

75 FR 52892 - Energy Conservation Program for Consumer Products: Test Procedures for Residential Water Heaters...

Science.gov (United States)

2010-08-30

... ``Energy Conservation Program for Consumer Products Other Than Automobiles,'' including residential water... final rule revising energy conservation standards for residential water heaters, direct heating.... EERE-2009-BT-TP-0013] RIN 1904-AB95 Energy Conservation Program for Consumer Products: Test Procedures...

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.

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

Subsidy programs on diffusion of solar water heaters: Taiwan's experience

International Nuclear Information System (INIS)

Chang, Keh-Chin; Lin, Wei-Min; Lee, Tsong-Sheng; Chung, Kung-Ming

2011-01-01

Financial incentives are essentially one of the key factors influencing diffusion of solar water heaters in many countries. Two subsidy programs were initiated by the government of Taiwan in 1986 (1986-1991) and 2000 (2000-present), respectively. Those long-term national programs are considered to be the driving force on local market expansion. In 2008, the regional subsidy programs for solar water heaters were announced by Kaohsiung city and Kiemen county, which resulted in the growth in sales. A revised subsidy was also initiated by the government of Taiwan in 2009. The subsidy is 50% more. However, the tremendous enlargement of market size with a high-level ratio of subsidy over total installation cost might result in a negative impact on a sustainable SWH industry and long-term development of the local market, which is associated with system design and post-installation service. This paper aims to address the relative efficiency and pitfalls of those national and regional programs. - Research Highlights: → The direct subsidy has been the driving force on market expansion in Taiwan. → Higher subsidy would certainly increase the total number of systems installed. → A high-level subsidy results in a negative impact on users or a sustainable industry.

Collecting performance of an evacuated tubular solar high-temperature air heater with concentric tube heat exchanger

International Nuclear Information System (INIS)

Wang, Ping-Yang; Li, Shuang-Fei; Liu, Zhen-Hua

2015-01-01

Highlights: • A novel evacuated tube solar high temperature air heater is designed. • The solar air heater system consists of 30 linked collecting units. • Every unit consisted of a evacuated tube, a simplified CPC and concentric tube. • The flow air is heated over temperature of 200 °C. - Abstract: A set of evacuated tube solar high temperature air heaters with simplified CPC (compound parabolic concentrator) and concentric tube heat exchanger is designed to provide flow air with a temperature of 150–230 °C for industrial production. The solar air heater system consists of 30 linked collecting units. Each unit includes a simplified CPC and an all-glass evacuated tube absorber with a concentric copper tube heat exchanger installed inside. A stainless steel mesh layer with high thermal conductivity is filled between the evacuated tube and the concentric copper tube. Air passes through each collecting unit, and its temperature increases progressively. An experimental investigation of the thermal performance of the air heater is performed, and the experimental results demonstrate the presented high-temperature solar air heater has excellent collecting performance and large output power, even in the winter. The measured thermal efficiency corresponding to the air temperature of 70 °C reaches 0.52. With the increase of air temperature, thermal efficiency reaches 0.35 at an air temperature of 150 °C, and 0.21 at an air temperature of 220 °C.

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

Heat Pump Water Heater Ducting Strategies with Encapsulated Attics in Climate Zones 2 and 4

Energy Technology Data Exchange (ETDEWEB)

Sweet, M. L. [Southface Energy Inst., Atlanta, GA (United States); Francisco, A. [Southface Energy Inst., Atlanta, GA (United States); Roberts, S. G. [Southface Energy Inst., Atlanta, GA (United States)

2016-05-01

The focus of this study is on the performance of HPWHs with several different duct configurations and their effects on whole building heating, cooling, and moisture loads. A.O. Smith 60 gallon Voltex (PHPT-60) heat pump water heaters (HPWHs) were included at two project sites and ducted to or located within spray foamed encapsulated attics. The effect of ducting a HPWH's air stream does not diminish its efficiency if the ducting does not reduce intake air temperature, which expands HPWH application to confined areas.

PERFORMANCE DETERIORATION OF THERMOSIPHON SOLAR FLAT PLATE WATER HEATER DUE TO SCALING

Directory of Open Access Journals (Sweden)

arunachala umesh chandavar

2011-12-01

Full Text Available 0 0 1 340 1943 International Islamic University 16 4 2279 14.0 Normal 0 false false false EN-US JA X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Times New Roman";} The performance of Flat plate Solar Water Heater deteriorates within five to twelve years of their installation due to factors related to manufacturing, operating conditions, lack of maintenance etc. Especially, problem due to scaling is significant as it is based on quality of water used. The remaining factors are system dependent and could be overcome by quality production. Software is developed by incorporating Hottel Whillier Bliss (H-W-B equation to ascertain the effect of scaling on system efficiency in case of thermosiphon system. In case of clean thermosiphon system, the instantaneous efficiency calculated at 1000 W/m2 radiation is 72 % and it drops to 46 % for 3.7 mm scale thickness. The mass flow rate is reduced by 90 % for 3.7 mm scale thickness. Whereas, the average temperature drop of water in the tank is not critical due to considerable heat content in water under severe scaled condition.  But practically in case of major scale growth, some of the risers are likely to get blocked completely which leads to negligible temperature rise in the tank. ABSTRAK: Prestasi plat rata pemanas air suria merosot selepas lima hingga dua belas tahun  pemasangannya disebabkan faktor-faktor yang berkaitan dengan pembuatannya, cara kendaliannya, kurangnya penyelenggaraan dan sebagainya.  Terutama sekali, masalah disebabkan scaling (tembunan endapan mineral perlu diambil berat kerana ianya bergantung kepada kualiti air yang digunakan. Faktor-faktor selebihya bersandarkan sistem dan ia

Impact of the operation of non-displaced feedwater heaters on the performance of Solar Aided Power Generation plants

International Nuclear Information System (INIS)

Qin, Jiyun; Hu, Eric; Nathan, Graham J.

2017-01-01

Highlights: • Impact of non-displaced feedwater heater on plant’s performance has been evaluated. • Two operation strategies for non-displaced feedwater heater has been proposed. • Constant temperature strategy is generally better. • Constant mass flow rate strategy is suit for rich solar thermal input. - Abstract: Solar Aided Power Generation is a technology in which low grade solar thermal energy is used to displace the high grade heat of the extraction steam in a regenerative Rankine cycle power plant for feedwater preheating purpose. The displaced extraction steam can then expand further in the steam turbine to generate power. In such a power plant, using the (concentrated) solar thermal energy to displace the extraction steam to high pressure/temperature feedwater heaters (i.e. displaced feedwater heaters) is the most popular arrangement. Namely the extraction steam to low pressure/temperature feedwater heaters (i.e. non-displaced feedwater heaters) is not displaced by the solar thermal energy. In a Solar Aided Power Generation plants, when solar radiation/input changes, the extraction steam to the displaced feedwater heaters requires to be adjusted according to the solar radiation. However, for the extraction steams to the non-displaced feedwater heaters, it can be either adjusted accordingly following so-called constant temperature strategy or unadjusted i.e. following so-called constant mass flow rate strategy, when solar radiation/input changes. The previous studies overlooked the operation of non-displaced feedwater heaters, which has also impact on the whole plant’s performance. This paper aims to understand/reveal the impact of the two different operation strategies for non-displaced feedwater heaters on the plant’s performance. In this paper, a 300 MW Rankine cycle power plant, in which the extraction steam to high pressure/temperature feedwater heaters is displaced by the solar thermal energy, is used as study case for this purpose. It

Desempenho de um aquecedor de água a biogás Performance of a water heater by biogas

Directory of Open Access Journals (Sweden)

Fabio M. da Silva

2005-12-01

Full Text Available Estudos foram desenvolvidos para dimensionar e adaptar o injetor do queimador principal de um aquecedor de água tipo acumulação de 75 L. O diâmetro do injetor foi redimensionado em função da pressão de serviço de 100 mm H2O e poder calorífico inferior do biogás de 21.600 kJ m-3 n, garantindo a manutenção da potência calorífica do equipamento de 20.900 kJ h-1. Os resultados demonstraram que o queimador adaptado operou com biogás adequadamente, com chama estável. A eficiência média do aquecedor foi de 68%, para ganho térmico de 36,7 ºC, correspondendo à temperatura final da água igual a 62,7 ºC, sendo consumido 0,796 m³n de biogás, aquecendo 75 L de água em 72 minutos.Studies had been developed to project and to adapt the injector of the main burner of water heater accumulated type of 75 L. The diameter of the injector was project in function of the pressure of service of 100 mm H2O and inferior calorific power of biogas of 21,600 kJ m-3 n, having guaranteed the maintenance of the calorific power of the equipment of 20,900 of kJ h-1 .The results had demonstrated that the adapted burner to operate with biogas operated adequately with a steady flame. The average efficiency of the heater was of 68%, for a thermal profit of 36.7 ºC, corresponding the final temperature of the water of 62.7 ºC being consumed 0.796 m³ n of biogas, heating 75 L of water in 72 minutes.

How to reduce risk of climate change: Domestic hot water production methanization and programmed timing of heaters

International Nuclear Information System (INIS)

Silvestrini, G.

1992-01-01

This paper first identifies a significant and deleterious trend, in terms of poor energy efficiency and high carbon dioxide emissions, towards the increased use of electric water heaters for sanitary hot water production in single family units. It then points out how the use of wall mounted methane fired boilers can result in overall energy savings (overall electric power consumption for domestic hot water production is estimated to represent one- quarter of Italy's total domestic power demand), as well as air pollution abatement. The feasibility of other methods of energy conservation and pollution abatement in domestic water heating are also examined. These include the use of solar hot water heaters, computerized timers which allow users to program the operation of their heating plants, and the adoption by residential communities of methane fuelled district heating plants

A figure of merit for selective absorbers in flat plate solar water heaters

CSIR Research Space (South Africa)

Roberts, DE

2013-12-01

Full Text Available We derive from first principles an analytical expression for a figure of merit (FM) for a selective solar absorber in a single glazed flat plate water heater. We first show that the efficiency of a collector with an absorber with absorptance α...

Economics of Condensing Gas Furnaces and Water Heaters Potential in Residential Single Family Homes

OpenAIRE

Lekov, Alex

2010-01-01

Residential space and water heating accounts for over 90percent of total residential primary gas consumption in the United States. Condensing space and water heating equipment are 10-30percent more energy-efficient than conventional space and water heating. Currently, condensing gas furnaces represent 40 percent of shipments and are common in the Northern U.S. market. Meanwhile, manufacturers are planning to develop condensing gas storage water heaters to qualify for Energy Star? certificati...

Experimental study on a prototype of heat pipe solar water heater using refrigerant R134a as a transfer fluid

Science.gov (United States)

Sitepu, T.; Sembiring, J.; Ambarita, H.

2018-02-01

A prototype of a solar water heater by using refrigerant as a heat transfer fluid is investigated experimentally. The objective is to explore the characteristics and the performance of the prototype. To make heat transfer from the collector to the heated fluid effectively, refrigerant R134a is used as a transfer. In the experiments, the initial pressure inside the heat pipe is varied. The prototype is exposed to solar irradiation in a location in Medan city for three days of the experiment. Solar collector temperatures, solar radiation, water temperature, and ambient temperature are measured. The efficiency of the system is analyzed. The results show that temperature of the hot water increases as the initial pressure of the working fluid increase. However, the increasing is not linear, and there must exist an optimum initial pressure. For the case with the refrigerant pressure of 110 psi, the maximum hot water temperature and maximum thermal efficiency are 45.36oC and 53.23%, respectively. The main conclusion can be drawn here is that solar water heater by using refrigerant R134a should be operated at initial pressure 110 psi.

Improvement in transdermal drug delivery performance by graphite oxide/temperature-responsive hydrogel composites with micro heater

International Nuclear Information System (INIS)

Yun, Jumi; Lee, Dae Hoon; Im, Ji Sun; Kim, Hyung-Il

2012-01-01

Transdermal drug delivery system (TDDS) was prepared with temperature-responsive hydrogel. The graphite was oxidized and incorporated into hydrogel matrix to improve the thermal response of hydrogel. The micro heater was fabricated to control the temperature precisely by adopting a joule heating method. The drug in hydrogel was delivered through a hairless mouse skin by controlling temperature. The efficiency of drug delivery was improved obviously by incorporation of graphite oxide due to the excellent thermal conductivity and the increased interfacial affinity between graphite oxide and hydrogel matrix. The fabricated micro heater was effective in controlling the temperature over lower critical solution temperature of hydrogel precisely with a small voltage less than 1 V. The cell viability test on graphite oxide composite hydrogel showed enough safety for using as a transdermal drug delivery patch. The performance of TDDS could be improved noticeably based on temperature-responsive hydrogel, thermally conductive graphite oxide, and efficient micro heater. - Graphical abstract: The high-performance transdermal drug delivery system could be prepared by combining temperature-responsive hydrogel, thermally conductive graphite oxide with improved interfacial affinity, and efficient micro heater fabricated by a joule heating method. Highlights: ► High performance of transdermal drug delivery system with an easy control of voltage. ► Improved thermal response of hydrogel by graphite oxide incorporation. ► Efficient micro heater fabricated by a joule heating method.

Second-law analysis of a two-phase self-pumping solar water heater

International Nuclear Information System (INIS)

Walker, H.A.; Davidson, J.H.

1992-01-01

In this paper entropy generated by operation of a two-phase self-pumping solar water heater under Solar Rating and Certification Corporation rating conditions is computed numerically in a methodology based on an exergy cascade. An order of magnitude analysis shows that entropy generation is dominated by heat transfer across temperature differences. Conversion of radiant solar energy incident on the collector to thermal energy within the collector accounts for 87.1 percent of total entropy generation. Thermal losses are responsible for 9.9 percent of total entropy generation, and heat transfer across the condenser accounts for 2.4 percent of the total entropy generation. Mixing in the tempering valve is responsible for 0.7 percent of the total entropy generation. Approximately one half of the entropy generated by thermal losses is attributable to the self-pumping process. The procedure to determine total entropy generation can be used in a parametric study to evaluate the performance of two-phase hot water heating systems relative to other solar water heating options

Building America Case Study: Multifamily Central Heat Pump Water Heaters, Davis, California

Energy Technology Data Exchange (ETDEWEB)

M. Hoeschele, E. Weitzel

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.

Building America Case Study: Multifamily Central Heat Pump Water Heaters, Davis, California

Energy Technology Data Exchange (ETDEWEB)

2017-03-08

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.

Temperature measurements from a horizontal heater test in G-Tunnel

International Nuclear Information System (INIS)

Lin, Wunan; Ramirez, A.L.; Watwood, D.

1991-10-01

A horizontal heater test was conducted in G-Tunnel, Nevada Test Site, to study the hydrothermal response of the rock mass due to a thermal loading. The results of the temperature measurements are reported here. The measured temperatures agree well with a scoping calculation that was performed using a model which investigates the transport of water, vapor, air, and heat in fractured porous media. Our results indicate that the temperature field might be affected by the initial moisture content of the rock, the fractures in the rock, the distance from the free surface of the alcove wall, and the temperature distribution on the heater surface. Higher initial moisture content, higher fracture density, and cooling from the alcove wall tend to decrease the measured temperature. The temperature on top of the horizontal heater can was about 30 degrees C greater than at the bottom throughout most of the heating phase, causing the rock temperatures above the heater to be greater than those below. Along a radius from the center of the heater, the heating created a dry zone, followed by a boiling zone and condensation zone. Gravity drainage of the condensed water in the condensation zone had a strong effect on the boiling process in the test region. The temperatures below and to the side of the heater indicated a region receiving liquid drainage from an overlying region of condensation. We verified that a thermocouple in a thin-wall tubing measures the same temperature as one grouted in a borehole

High Efficiency Water Heating Technology Development Final Report, Part II: CO₂ and Absorption-Based Residential Heat Pump Water Heater Development

Energy Technology Data Exchange (ETDEWEB)

Gluesenkamp, Kyle R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Abdelaziz, Omar [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Patel, Viral K. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Mandel, Bracha T. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); de Almeida, Valmor F. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

2017-05-01

The two objectives of this project were to 1.demonstrate an affordable path to an ENERGY STAR qualified electric heat pump water heater (HPWH) based on low-global warming potential (GWP) CO₂ refrigerant, and 2.demonstrate an affordable path to a gas-fired absorption-based heat pump water heater with a gas energy factor (EF) greater than 1.0. The first objective has been met, and the project has identified a promising low-cost option capable of meeting the second objective. This report documents the process followed and results obtained in addressing these objectives.

Relationship between Organic Carbon and Opportunistic Pathogens in Simulated Glass Water Heaters

Directory of Open Access Journals (Sweden)

Krista Williams

2015-06-01

Full Text Available Controlling organic carbon levels in municipal water has been hypothesized to limit downstream growth of bacteria and opportunistic pathogens in premise plumbing (OPPPs. Here, the relationships between influent organic carbon (0–15,000 µg ozonated fulvic acid /L and the number of total bacteria [16S rRNA genes and heterotrophic plate counts (HPCs] and a wide range of OPPPs (gene copy numbers of Acanthamoeba polyphaga, Vermamoeba vermiformis, Legionella pneumophila, and Mycobacterium avium were examined in the bulk water of 120-mL simulated glass water heaters (SGWHs. The SGWHs were operated at 32–37 °C, which is representative of conditions encountered at the bottom of electric water heaters, with water changes of 80% three times per week to simulate low use. This design presented advantages of controlled and replicated (triplicate conditions and avoided other potential limitations to OPPP growth in order to isolate the variable of organic carbon. Over seventeen months, strong correlations were observed between total organic carbon (TOC and both 16S rRNA gene copy numbers and HPC counts (avg. R2 > 0.89. Although M. avium gene copies were occasionally correlated with TOC (avg. R2 = 0.82 to 0.97, for 2 out of 4 time points and over a limited TOC range (0–1000 µg/L, no other correlations were identified between other OPPPs and added TOC. These results suggest that reducing organic carbon in distributed water is not adequate as a sole strategy for controlling OPPPs, although it may have promise in conjunction with other approaches.

Relationship between Organic Carbon and Opportunistic Pathogens in Simulated Glass Water Heaters.

Science.gov (United States)

Williams, Krista; Pruden, Amy; Falkinham, Joseph O; Edwards, Marc; Williams, Krista; Pruden, Amy; Falkinham, Joseph O; Edwards, Marc

2015-06-09

Controlling organic carbon levels in municipal water has been hypothesized to limit downstream growth of bacteria and opportunistic pathogens in premise plumbing (OPPPs). Here, the relationships between influent organic carbon (0-15,000 µg ozonated fulvic acid /L) and the number of total bacteria [16S rRNA genes and heterotrophic plate counts (HPCs)] and a wide range of OPPPs (gene copy numbers of Acanthamoeba polyphaga, Vermamoeba vermiformis, Legionella pneumophila, and Mycobacterium avium) were examined in the bulk water of 120-mL simulated glass water heaters (SGWHs). The SGWHs were operated at 32-37 °C, which is representative of conditions encountered at the bottom of electric water heaters, with water changes of 80% three times per week to simulate low use. This design presented advantages of controlled and replicated (triplicate) conditions and avoided other potential limitations to OPPP growth in order to isolate the variable of organic carbon. Over seventeen months, strong correlations were observed between total organic carbon (TOC) and both 16S rRNA gene copy numbers and HPC counts (avg. R2 > 0.89). Although M. avium gene copies were occasionally correlated with TOC (avg. R2 = 0.82 to 0.97, for 2 out of 4 time points) and over a limited TOC range (0-1000 µg/L), no other correlations were identified between other OPPPs and added TOC. These results suggest that reducing organic carbon in distributed water is not adequate as a sole strategy for controlling OPPPs, although it may have promise in conjunction with other approaches.

Heat Pump Water Heater Technology: Experiences of Residential Consumers and Utilities

Energy Technology Data Exchange (ETDEWEB)

Ashdown, BG

2004-08-04

This paper presents a case study of the residential heat pump water heater (HPWH) market. Its principal purpose is to evaluate the extent to which the HPWH will penetrate the residential market sector, given current market trends, producer and consumer attributes, and technical parameters. The report's secondary purpose is to gather background information leading to a generic framework for conducting market analyses of technologies. This framework can be used to compare readiness and to factor attributes of market demand back into product design. This study is a rapid prototype analysis rather than a detailed case analysis. For this reason, primary data collection was limited and reliance on secondary sources was extensive. Despite having met its technical goals and having been on the market for twenty years, the HPWH has had virtually no impact on contributing to the nation's water heating. In some cases, HPWH reliability and quality control are well below market expectations, and early units developed a reputation for unreliability, especially when measured against conventional water heaters. In addition to reliability problems, first costs of HPWH units can be three to five times higher than conventional units. Without a solid, well-managed business plan, most consumers will not be drawn to this product. This is unfortunate. Despite its higher first costs, efficiency of an HPWH is double that of a conventional water heater. The HPWH also offers an attractive payback period of two to five years, depending on hot water usage. On a strict life-cycle basis it supplies hot water very cost effectively. Water heating accounts for 17% of the nation's residential consumption of electricity (see chart at left)--water heating is second only to space heating in total residential energy use. Simple arithmetic suggests that this figure could be reduced to the extent HPWH technology displaces conventional water heating. In addition, the HPWH offers other

Experimental study of a high-efficiency low-emission surface combustor-heater

International Nuclear Information System (INIS)

Xiong, Tian-yu; Khinkis, M.J.; Fish, F.F.

1991-01-01

The surface combustor-heater is a combined combustion/heat-transfer device in which the heat-exchange surfaces are embedded in a stationary bed of refractory material where gaseous fuel is burned. Because of intensive heat radiation from the hot solid particles and enhanced heat convection from the gas flow to the heat-exchange tubes, heat transfer is significantly intensified. Removing heat simultaneously with the combustion process has the benefit of reducing the combustion temperature, which suppresses NO x formation. A basic experimental study was conducted on a 60-kW bench-scale surface combustor-heater with two rows of water-cooled tube coils to evaluate its performance and explore the mechanism of combined convective-radiative heat transfer and its interaction with combustion in the porous matrix. Combustion stability in the porous matrix, heat-transfer rates, emissions, and pressure drop through the unit have been investigated for the variable parameters of operation and unit configurations. Experimental results have demonstrated that high combustion intensity (up to 2.5 MW/m 2 ), high heat-transfer rates (up to 310 kW/m 2 ), high density of energy conversion (up to 8 MW/m 3 ), as well as ultra-low emissions (NO x and CO as low as 15 vppm*) have been achieved. The excellent performance of the test unit and the extensive data obtained from the present experimental study provide the basis for further development of high-efficiency and ultra low-emission water heaters, boilers, and process heaters based on the surface combustor-heater concept. 4 refs., 16 figs

78 FR 7394 - Notification of Proposed Production Activity; GE Appliances; Subzone 29C (Electric Water Heaters...

Science.gov (United States)

2013-02-01

..., freezers, apparel washing machines and dryers, electric ranges, and air-conditioners, under FTZ procedures...), fan motors, fans, filter/ dryers, expansion valves, accumulators, parts of electric water heaters...

Improvement in transdermal drug delivery performance by graphite oxide/temperature-responsive hydrogel composites with micro heater

Energy Technology Data Exchange (ETDEWEB)

Yun, Jumi [Department of Fine Chemical Engineering and Applied Chemistry, BK21-E2M, Chungnam National University, Daejeon 305-764 (Korea, Republic of); Lee, Dae Hoon [Environment Research Division, Korea Institute of Machinery and Materials, 171 Jang-dong, Yusong-gu, Daejeon 305-343 (Korea, Republic of); Im, Ji Sun [Department of Fine Chemical Engineering and Applied Chemistry, BK21-E2M, Chungnam National University, Daejeon 305-764 (Korea, Republic of); Kim, Hyung-Il, E-mail: hikim@cnu.ac.kr [Department of Fine Chemical Engineering and Applied Chemistry, BK21-E2M, Chungnam National University, Daejeon 305-764 (Korea, Republic of)

2012-08-01

Transdermal drug delivery system (TDDS) was prepared with temperature-responsive hydrogel. The graphite was oxidized and incorporated into hydrogel matrix to improve the thermal response of hydrogel. The micro heater was fabricated to control the temperature precisely by adopting a joule heating method. The drug in hydrogel was delivered through a hairless mouse skin by controlling temperature. The efficiency of drug delivery was improved obviously by incorporation of graphite oxide due to the excellent thermal conductivity and the increased interfacial affinity between graphite oxide and hydrogel matrix. The fabricated micro heater was effective in controlling the temperature over lower critical solution temperature of hydrogel precisely with a small voltage less than 1 V. The cell viability test on graphite oxide composite hydrogel showed enough safety for using as a transdermal drug delivery patch. The performance of TDDS could be improved noticeably based on temperature-responsive hydrogel, thermally conductive graphite oxide, and efficient micro heater. - Graphical abstract: The high-performance transdermal drug delivery system could be prepared by combining temperature-responsive hydrogel, thermally conductive graphite oxide with improved interfacial affinity, and efficient micro heater fabricated by a joule heating method. Highlights: Black-Right-Pointing-Pointer High performance of transdermal drug delivery system with an easy control of voltage. Black-Right-Pointing-Pointer Improved thermal response of hydrogel by graphite oxide incorporation. Black-Right-Pointing-Pointer Efficient micro heater fabricated by a joule heating method.

Diffusion of solar water heaters in regional China: Economic feasibility and policy effectiveness evaluation

International Nuclear Information System (INIS)

Ma, Ben; Song, Guojun; Smardon, Richard C.; Chen, Jing

2014-01-01

Whereas the technical feasibility of solar water heaters (SWHs) has long been established, the economic feasibility of SWHs in regional China remains to be examined. This paper constructs cost models to calculate costs per unit energy saving of SWHs in 27 Chinese provincial capital cities. The cost effectiveness of SWHs is examined at the national level. At a micro level, we analyze the financial attractiveness of consumers’ investment in SWHs. A panel data model is employed to evaluate the effectiveness of a subsidy program in rural China. The results show that SWH costs, ranging from 0.305 to 0.744 CNY/kW h, are much lower than those of other major renewable energies across China. This finding indicates that the diffusion of SWHs is a cost-effective way to reach China’s renewable energy target. For consumers, incentive programs for SWHs are needed to improve the financial attractiveness of the devices in China. Existing subsidy policies for rural China have failed to significantly enhance the deployment of SWHs. The causes of the failure are examined and a new incentive program is suggested for rural areas of the country. - Highlights: • We examine the economic feasibility of solar water heaters in 27 Chinese cities. • We evaluate policy effectiveness of solar water heaters (SWHs) using panel data. • Diffusion of SWHs is cost effective in fulfilling China’s renewable energy target. • Financial attractiveness of SWHs is limited without incentive programs. • The existing subsidy policy is proved to be a failure and a new program is suggested

MHD oxidant intermediate temperature ceramic heater study

Science.gov (United States)

Carlson, A. W.; Chait, I. L.; Saari, D. P.; Marksberry, C. L.

1981-09-01

The use of three types of directly fired ceramic heaters for preheating oxygen enriched air to an intermediate temperature of 1144K was investigated. The three types of ceramic heaters are: (1) a fixed bed, periodic flow ceramic brick regenerative heater; (2) a ceramic pebble regenerative heater. The heater design, performance and operating characteristics under conditions in which the particulate matter is not solidified are evaluated. A comparison and overall evaluation of the three types of ceramic heaters and temperature range determination at which the particulate matter in the MHD exhaust gas is estimated to be a dry powder are presented.

Management of aging of water heaters in nuclear power plants

International Nuclear Information System (INIS)

Martin-Serrano Ledesma, C.; Toro del toro, J.; Real Rubio, I.; Garcia Montejano, A.

2014-01-01

The scope of this work includes the study of all feedwater heaters (from 1 to 6) in their two trains (A and B). In this study the main degradation phenomena that affect them, the operating parameters that can warn of a possible malfunction of the heater and possible strategies inspection, repair and replacement are analyzed. As a result of this study, a higher priority is obtained at a lower state of degradation of the heaters, possibly with a strategy inspection, repair or replacement, for each recharge, until the end of life of the plant. This will be a live program, which must be fed back to the studies of the parameters of operation of the heater during operation and results of the inspection of each recharge. May verify the effectiveness of aging management program using different indicators. (Author)

Quasi-steady state thermal performances of a solar air heater with ...

African Journals Online (AJOL)

Quasi-steady state thermal performance of a solar air heater with a combined absorber is studied. The whole energy balance equations related to the system were articulated as a linear system of temperature equations. Solutions to this linear system were assessed from program based on an iterative process. The mean ...

Performance evaluation of a once-through multi-stage flash distillation system: Impact of brine heater fouling

International Nuclear Information System (INIS)

Baig, Hasan; Antar, Mohamed A.; Zubair, Syed M.

2011-01-01

Multi-stage flash distillation (MSF) system modeling involves a number of process variables. An estimation of all these process variables requires both analytical solutions and experimental/field analysis. However, the accurate estimate of variables related to the brine heater operation in a MSF system is very important for a reliable operation of the system. For example, steam operating conditions as well as the brine properties including fouling of the brine heater tubes have a significant effect on the heat transfer characteristics of the brine heater, which in turn influence the distillate output from the system. In this study, the effect of various design as well as operating conditions on the performance ratio (PR), brine temperature and salinity as it leaves the last flash stage are investigated in a once-through system. Increasing the number of stages from 24 to 32 has a significant effect on the PR, it ranges between 79% (for ΔT = 1.5) and 327% (for ΔT = 2.3) for a top-brine temperature of 106 o C. This value increase as the top-brine temperature increases. Increasing the stage-to-stage temperature difference increases the water salinity as it leaves the final stage and reduces its temperature that would imply better energy utilization within the plant. Results show that brine side heat exchanger fouling has a significant effect in decreasing the overall heat transfer coefficient, which reduces the production rate as the fouling increases with time. A sensitivity analysis to identify the key parameters, which can have a significant influence on the desalination plant performance, is carried out in an attempt to contribute a better understanding and operation of MSF desalination processes.

Experimental Study of a Thermosyphon Solar Water Heater Coupled to a Fibre-Reinforced Plastic (FRP) Storage Tank

International Nuclear Information System (INIS)

Nwosu, P. N.; Oparaku, O. U.; Okonkwo, W. I.; Unachukwu, G. O.; Agbiogwu, D.

2011-01-01

The thermal performance of the thermosyphon solar water heater was analyzed to show its applicability in a tropical climate using data of cloudy, sunny and hazy days. The average daily efficiency of the parallel-connected module, ranged between 35 and 40%. Also, an analysis of the temperature storage characteristics of a novel fibre-reinforced plastic (FRP) storage tank was undertaken. The inlet andoutlet positions were determined using the recommendation of Simon and Wenxian [1]: the optional position for the inlet/outlet was around the very top/bottom of the tank. The obtained results showed that the coupled FRP tank substantially retained and delivered the stored hot water during off-sunshine hours with minimal losses, and stratification occurred in the tank as a result. In view of the thermal performance, FRP materials can be efficiently employed in the design of solar hot water storage tanks. (authors)

Exergy analysis of integrated photovoltaic thermal solar water heater under constant flow rate and constant collection temperature modes

NARCIS (Netherlands)

Tiwari, A.; Dubey, Swapnil; Sandhu, G.S.; Sodha, M.S.; Anwar, S.I.

2009-01-01

In this communication, an analytical expression for the water temperature of an integrated photovoltaic thermal solar (IPVTS) water heater under constant flow rate hot water withdrawal has been obtained. Analysis is based on basic energy balance for hybrid flat plate collector and storage tank,

Large-scale in situ heater tests for hydrothermal characterization at Yucca Mountain

International Nuclear Information System (INIS)

Buscheck, T.A.; Wilder, D.G.; Nitao, J.J.

1993-01-01

To safely and permanently store high-level nuclear waste, the potential Yucca Mountain repository site must mitigate the release and transport of radionuclides for tens of thousands of years. In the failure scenario of greatest concern, water would contact a waste package, accelerate its failure rate, and eventually transport radionuclides to the water table. Our analyses indicate that the ambient hydrological system will be dominated by repository-heat-driven hydrothermal flow for tens of thousands of years. In situ heater tests are required to provide an understanding of coupled geomechanical-hydrothermal-geochemical behavior in the engineered and natural barriers under repository thermal loading conditions. In situ heater tests have been included in the Site Characterization Plan in response to regulatory requirements for site characterization and to support the validation of process models required to assess the total systems performance at the site. Because of limited time, some of the in situ tests will have to be accelerated relative to actual thermal loading conditions. We examine the trade-offs between the limited test duration and generating hydrothermal conditions applicable to repository performance during the entire thermal loading cycle, including heating (boiling and dry-out) and cooldown (re-wetting). For in situ heater tests to be applicable to actual repository conditions, a minimum heater test duration of 6-7 yr (including 4 yr of full-power heating) is required

Assessing Consumer Values and the Supply-Chain Market for the Integrated Water Heater/Dehumidifier

Energy Technology Data Exchange (ETDEWEB)

Ashdown, BG

2005-01-11

This paper presents a case study of the potential market for the dual-service residential integrated water heater/dehumidifier (WHD). Its principal purpose is to evaluate the extent to which this integrated appliance might penetrate the residential market sector, given current market trends, producer and consumer attributes, and technical parameters. The report's secondary purpose is to gather background information leading to a generic framework for conducting market analyses of technologies. This framework can be used to assess market readiness as well as factor preferred product attributes into the design to drive consumer demand for this product. This study also supports analysis for prototype design. A full market analysis for potential commercialization should be conducted after prototype development. The integrated WHD is essentially a heat-pump water heater (HPWH) with components and controls that allow dedicated dehumidification. Adequate residential humidity control is a growing issue for newly constructed residential homes, which are insulated so well that mechanical ventilation may be necessary to meet fresh air requirements. Leveraging its successful experience with the energy-efficient design improvement for the residential HPWH, the Oak Ridge National Laboratory's (ORNL's) Engineering Science and Technology Division's (ESTD's) Building Equipment Group designed a water-heating appliance that combines HPWH efficiency with dedicated dehumidification. This integrated appliance could be a low-cost solution for dehumidification and efficient electric water heating. ORNL is partnering with Western Carolina University, Asheville-Buncombe Technical Community College, American Carolina Stamping Company, and Clemson University to develop this appliance and assess its market potential. For practical purposes, consumers are indifferent to how water is heated but are very interested in product attributes such as initial first cost

Thermo-hydraulic performance of solar air heater having multiple v-shaped rib roughness on absorber plates

Directory of Open Access Journals (Sweden)

Dhananjay Kumar

2018-03-01

Full Text Available This paper presents the performance analysis of the effect of geometrical parameters having multiple v-shaped rib roughness on the airflow side of the absorber plates. Mathematical approach and solution procedure for the analysis of such a solar air heater has been developed theoretically and MATLAB code generated for the solution of the mathematical equations. The effect of parameters such as flow Reynolds number and Relative roughness height on the thermohydraulic performance have been examined and compared with the conventional flat plate solar air heater. A substantial improvement in thermal efficiency of roughened solar air heater as compared to smooth one due to appreciable enhancement in heat transfer coefficient. The enhancement in heat transfer coefficient is also accompanied by a considerable enhancement in pumping power requirement due to the increase in friction factor.

COMBINED UNCOVERED SHEET-AND-TUBE PVT-COLLECTOR SYSTEM WITH BUILT-IN STORAGE WATER HEATER

Directory of Open Access Journals (Sweden)

Muhammad Abid

2012-02-01

Full Text Available This work describes the design and investigation of a simple combined uncovered sheet-and-tube photo-voltaic-thermal (PVT collector system. The PVT-collector system consists of a support, standard PV module (1.22x0.305m, area=0.37m2, fill factor=0.75, sheet-and-tube water collector and storage tank-heater. The collector was fixed under PV module. Inclination angle of the PVT-collector to the horizontal plane was 45 degree. The storage tank-heater played double role i.e. for storage of hot water and for water heating. The PVT-collector system could work in the fixed and tracking modes of operation. During investigations of PVT-collector in natural conditions, solar irradiance, voltage and current of PV module, ambient temperature and water temperature in storage tank were measured. Average thermal and electrical powers of the PVT-collector system at the tracking mode of operation observed were 39W and 21W, with efficiencies of 15% and 8% respectively at the input power of 260W. The maximum temperature of the water obtained was 42oC. The system was observed efficient for low-temperature applications. The PVT-collector system may be used as a prototype for design of PVT-collector system for domestic application, teaching aid and for demonstration purposes.

Prediction of photovoltaic and solar water heater diffusion and evaluation of promotion policies on the basis of consumers’ choices

International Nuclear Information System (INIS)

Yamaguchi, Yohei; Akai, Kenju; Shen, Junyi; Fujimura, Naoki; Shimoda, Yoshiyuki; Saijo, Tatsuyoshi

2013-01-01

Highlights: ► Consumers’ preference on PV and solar water heater were investigated. ► Diffusion of the technologies in Japan was modeled by using Bass diffusion model. ► Policy measures to diffuse the technologies were evaluated by using the framework. ► Subsidy is more cost effective than FIT to diffuse PV. ► Public perception is the bottleneck of diffusion of solar water heater. -- Abstract: This paper proposes an integrated analytical framework consisting of the following three steps: (1) investigation of consumers’ preferences, (2) prediction of technology diffusion by taking into account consumers’ preferences, and (3) estimation of CO 2 emission reduction caused by the diffusion of the examined technology. By using this framework, this paper evaluates the policy measures implemented for disseminating photovoltaics and solar water heaters in terms of the contribution to reducing CO 2 emissions from the residential sector. We investigated consumer preferences for these technologies as well as the effects of attributes such as installation cost, energy price, energy efficiency, and perception on consumers’ choices. Considering these effects, we developed a model that estimates the diffusion of these technologies into the residential sector of Japan through 2025 and the resulting CO 2 emission reduction. We found that the policy measures for the diffusion of photovoltaics that reduce initial cost (e.g., subsidy programs) are more cost effective for reducing CO 2 emission than those reducing users’ operating expenditure (e.g., feed-in tariff programs). For solar water heater to be able to reduce the CO 2 emissions considerably, the public perception must be improved.

A viable CDM model for solar water heaters; CDM-Clean Development Mechanism

Energy Technology Data Exchange (ETDEWEB)

2008-09-15

It is a well known fact that solar water Heaters (SWH) replace fossil fuels and they do not represent business as usual scenario. Therefore use of this appliance can qualify to be considered as Clean Development Mechanism (CDM) project. However a single solar water heater is a very small unit to be able to generate sufficient Certified Emission Reductions (CERs) to pursue it as a CDM project. Even if the project is considered at the level of local venders or at the level of a company engaged in manufacturing SWH, the CERs still remain very small. The study examines the size of the project from the perspective of its viability as a CDM project and also explores other related issues such as additionality requirement, selection of methodology, baseline calculations, approach for stakeholders' comments, potential bundlers, monitoring and verification, and required policy interventions. Bank of Maharashtra (BOM), a commercial bank in India engaged in financing Solar Water Heaters (SWH), was considered as the base for the study. The CERs were calculated considering Electricity and LPG as the baseline. For the purpose of sensitivity analysis, various price bands for CERs (between US$ 15-25/CER) were considered. The analysis was carried out with bundling of SWH at BOM level, and at the Association of Banks (AOB) / Ministry level (in which case SWH financed by several banks are bundled). Recently approved Programme of Activities (PoA) approach was also considered in the analysis. The analysis clearly indicated that: 1) The CDM project with bundling at an individual bank level with about 8600 installations, though cash surplus, would generate the cash just to meet its own sustainability. But it is a very small project. 2) Bundling of installations by various banks, through an entity such as Association of Banks, would be a viable and sustainable CDM project due to benefits arising out of scale of economy. 3) The profitability of the CDM project would improve further if

Thermal-mechanical-hydrological-chemical responses in the single heater test at the ESF

International Nuclear Information System (INIS)

Lin, W.; Blair, S.; Buettner, M

1997-01-01

The Single Heater Test (SHT) is conducted in the Exploratory Studies Facility (ESF) to study the thermal-mechanical responses of the rock mass. A set of boreholes were drilled in the test region for conducting a scoping test of the coupled thermal-mechanical- hydrological-chemical (TMHC) processes. The holes for the TMHC tests include electrical resistivity tomography (ERT), neutron logging/temperature, hydrological, and optical multiple point borehole extensometers. A 4-kW heater was installed in the heater hole, and was energized on August 26, 1996. Some observed movements of the water around the heater are associated with a possible dry-out region near the heater. The water that has been moved is more dilute than the in situ ground water, except for the concentration of Ca. This indicates that fractures are the major water pathways, and the displaced water may have reached an equilibrium with carbonate minerals on the fracture surfaces. No mechanical-hydrological coupling has been observed. The tests are on-going, and more data will be collected and analyzed

蓄能型太阳能热泵热水器性能系数的分析%Coefficient of performance of solar heat pump water heater with energy storage

Institute of Scientific and Technical Information of China (English)

吴薇; 卫梁彦; 程清; 王玲珑

2011-01-01

To solve the problem that solar heat pump water heater was prone to be affected by weather, a novel water heater integrated with collection, storage and evaporation was proposed. The principle, characteristics, operating modes and structure of the collector-storage-evaporator system were investigated. Using phase change material of decanoic acid to store solar radiation in sunny days as low-temperature source, hot water was produced at night or in continuous rainy days. Thermal efficiency of heat pump system was increased significantly, and the operating unstableness of the heat pump system caused by interval solar energy was also solved. Experiments under different conditions and operating modes in spring were conducted, and the coefficient of performance ( COP) of the system was analyzed. The results indicate that COP of this novel solar heat pump water heater with energy storage is higher than that of ordinary solar heat pump water heater at the same weather condition. The average COP of this system is 7. 56 with maximum of 8. 9 for average solar radiation of 592 W·m-2. COP can also reach 6.4 even at night, which means that weather has slight influence on COP.%针对太阳能热泵热水器受天气变化影响的问题,提出了一种新型的集热-蓄能-蒸发一体化太阳能热泵热水器,给出了系统的原理、特点、运行模式和集热-蓄能-蒸发器的结构形式,以癸酸为相变材料储存晴天的太阳辐射能,作为热泵在夜间和连续阴雨天时的低温热源制得热水,提高了热泵的制热效率,解决了太阳能间歇性所造成的系统运行不稳定的问题.进行了春季不同工况、不同工作模式的试验,分析了系统的性能系数COP,得出该系统的平均COP为7.56.太阳辐射强度均值为592 W·m-2的天气条件下,COP可达8.9；即使在夜间,COP仍能达到6.4,均高于相同天气条件下普通太阳能热泵热水器的COP,该系统的COP受天气变化影响较小.

Development of Low-Cost Solar Water Heater Using Recycled Solid Waste for Domestic Hot Water Supply

Directory of Open Access Journals (Sweden)

Talib Din Abdul

2018-01-01

Full Text Available This research is focused on the development of a low-cost solar water heater (SWH system by utilizing solid waste material as part of system elements. Available technologies of the solar water heater systems, heat collectors and its components were reviewed and the best system combinations for low cost design were chosen. The passive-thermosiphon system have been chosen due to its simplicity and independency on external power as well as conventional pump. For the heat collector, flat plate type was identified as the most suitable collector for low cost design and suits with Malaysia climate. Detail study on the flat plate collector components found that the heat absorber is the main component that can significantly reduce the solar collector price if it is replaced with recycled solid waste material. Review on common solid wastes concluded that crushed glass is a non-metal material that has potential to either enhance or become the main heat absorber in solar collector. A collector prototype were then designed and fabricated based on crashed glass heat collector media. Thermal performance test were conducted for three configurations where configuration A (black painted aluminum absorber used as benchmark, configuration B (crushed glass added partially that use glass for improvement, and lastly configuration C (black colored crushed glass that use colored glass as main absorber. Result for configuration B have shown a negative effect where the maximum collector efficiency is 26.8% lower than configuration A. Nevertheless, configuration C which use black crushed glass as main heat absorber shown a comparable maximum efficiency which is at 82.5% of the maximum efficiency for configuration A and furthermore have shown quite impressive increment of efficiency at the end of the experiment. Hence, black colored crushed glass is said to have quite a good potential as the heat absorber material and therefore turn out to be a new contender to other non

Large-scale in situ heater tests for hydrothermal characterization at Yucca Mountain

International Nuclear Information System (INIS)

Buscheck, T.A.; Wilder, D.G.; Nitao, J.J.

1993-01-01

To safely and permanently store high-level nuclear-waste, the potential Yucca Mountain repository site must mitigate the release and transport of radionuclides for tens of thousands of years. In the failure scenario of greatest concern, water would contact a waste package, accelerate its failure rate, and eventually transport radionuclides to the water table. Our analysis indicate that the ambient hydrological system will be dominated by repository-heat-driven hydrothermal flow for tens of thousands of years. In situ heater tests are required to provide an understanding of coupled geomechanical-hydrothermal-geochemical behavior in the engineered and natural barriers under repository thermal loading conditions. In situ heater tests have been included in the Site Characterization Plan in response to regulatory requirements for site characterization and to support the validation of process models required to assess the total systems performance at the site. The success of the License Application (LA) hinges largely on how effectively we validate the process models that provide the basis for performance assessment. Because of limited time, some of the in situ tests will have to be accelerated relative to actual thermal loading conditions. We examine the trade-offs between the limited test duration and generating hydrothermal conditions applicable to repository performance during the entire thermal loading cycle, including heating (boiling and dry-out) and cooldown (re-wetting). For in situ heater tests duration of 6-7 yr (including 4 yr of full-power heating) is required. The parallel use of highly accelerated, shorter-duration tests may provide timely information for the LA, provided that the applicability of the test results can be validated against ongoing nominal-rate heater tests

Packaged die heater

Science.gov (United States)

Spielberger, Richard; Ohme, Bruce Walker; Jensen, Ronald J.

2011-06-21

A heater for heating packaged die for burn-in and heat testing is described. The heater may be a ceramic-type heater with a metal filament. The heater may be incorporated into the integrated circuit package as an additional ceramic layer of the package, or may be an external heater placed in contact with the package to heat the die. Many different types of integrated circuit packages may be accommodated. The method provides increased energy efficiency for heating the die while reducing temperature stresses on testing equipment. The method allows the use of multiple heaters to heat die to different temperatures. Faulty die may be heated to weaken die attach material to facilitate removal of the die. The heater filament or a separate temperature thermistor located in the package may be used to accurately measure die temperature.

Development of design program for small-sized gas absorption chiller/heaters

Energy Technology Data Exchange (ETDEWEB)

Yoon, J.I.; Kwon, O.K.; Moon, C.K. [Pukyong National University, Pusan (Korea); Yang, Y.M.; Kim, H.Y. [R and D Center, Korea Gas Corporation, Ansan (Korea)

1999-10-01

Analysis of basic data is performed for development of small size water-cooled household absorption chiller/heater using non CFC refrigerant, analytic simulation program of air cooling performance is developed that system has 1.5-10RT of air cooling performance, we perform cycle analysis and numerical simulation. We develope a performance analysis of simulation program to perform a basic design for 1.5-10RT apparatus of small size system of development model in gas driven double effect absorption chiller/heater. The system working condition and operation limit condition is decided from the existing data which is analyzed and the conference with KOGAS. After the basic input variable and regular condition is established for heat cycle analysis, the simulation algorithm is set up and performance simulation program is coded according to the organized algorithm. The basic design of optimum system is completed from parametric study using developed simulation program and establishing the design variable range of developing object model. 20 refs., 30 figs., 9 tabs.

Performance analysis of a hybrid photovoltaic thermal solar air heater

International Nuclear Information System (INIS)

Othman, Mohd Yusof; Yatim, Baharudin; Abu Bakar, Mohd Nazari; Sopian, Kamaruzzaman

2006-01-01

A photovoltaic (PV/T) air heater is a collector that combines thermal and photovoltaic systems in one single hybrid generating unit. It generators both thermal and electrical energies simultaneously. A new design of a double-pass photovoltaic-thermal solar air collector with CPC and fins was successfully developed and fabricated at Universiti Kebangsaam Malaysia. This collector tested under actual environmental conditions to study its performance over a range of operating conditions. The test set-up, instrumentation and measurement are described further. It was found that the performance of the collector was in agreement with the theoretical prediction. Results of the outdoors test are presented and discussed(Author)

DEVELOPMENT OF TECHNICAL DECISIONS FOR HEAT SUPPLY WITH TUBULAR GAS HEATERS

Directory of Open Access Journals (Sweden)

IRODOV V. F.

2017-05-01

Full Text Available Annotation. Problems formulation. The problem that is solved is the development of autonomous heat supply systems that reduce the capital costs of construction and increase the efficiency of the use of energy resources. One of the ways to solve this problem is the use of tubular gas heaters. For this, it is necessary to develop new technical solutions for heat supply with tubular gas heaters, as well as scientific and methodological support for the development, construction and operation of heat supply systems with tubular gas heaters. Analysis of recent research. Preliminary studies of infrared tubular gas heaters are considered, which were used to heat industrial enterprises with sufficiently high premises. The task was to extend the principles of heat supply by means of tubular heaters for heating air, water and heating medium in relatively low rooms. Goal and tasks. To lay out the development of technical solutions for heat supply with tubular gas heaters, which increase the efficiency and reliability of heat supply systems and extend the use of tubular gas heaters in heat supply. Results. Technical solutions for heat supply with tubular gas heaters have made it possible to extend their applications for heating air, water and heating medium in relatively low rooms. Scientific novelty. New technical solutions for heat supply with tubular gas heaters increase the efficiency of using fuel and energy resources at low capital costs. Practical significance. Technical solutions for heat supply using tubular heaters have the potential for wide application in the heat supply of industrial, public and residential facilities. Conclusions. For two decades, new technical solutions for heat supply with tubular gas heaters have been developed, which increase the efficiency and reliability of heat supply systems and can be widely used for autonomous heating.

Experimental analysis of distinct design of a batch solar water heater with integrated collector storage system

Directory of Open Access Journals (Sweden)

Varghese Jaji

2007-01-01

Full Text Available The performance of a new design of batch solar water heater has been studied. In this system, the collector and storage were installed in one unit. Unlike the conventional design consisting of small diameter water tubes, it has a single large diameter drum which serves the dual purpose of absorber tube and storage tank. In principle it is a compound parabolic collector. The drum is sized to have a storage capacity of 100 liter to serve a family of four persons. The tests were carried out with a single glass cover and two glass covers. The tests were repeated for several days. Performance analysis of the collector has revealed that it has maximum mean daily efficiency with two glass covers as high as 37.2%. The maximum water temperature in the storage tank of 60°C has been achieved for a clear day operation at an average solar beam radiation level of 680 W/m2 and ambient temperature of 32°C. To judge the operating characteristics and to synchronize utility pattern of the collector, the different parameters such as efficiency, mean plate temperature and mass flow rate has been investigated.

Heater Validation for the NEXT-C Hollow Cathodes

Science.gov (United States)

Verhey, Timothy R.; Soulas, George C.; Mackey, Jonathan A.

2018-01-01

Swaged cathode heaters whose design was successfully demonstrated under a prior flight project are to be provided by the NASA Glenn Research Center for the NEXT-C ion thruster being fabricated by Aerojet Rocketdyne. Extensive requalification activities were performed to validate process controls that had to be re-established or revised because systemic changes prevented reuse of the past approaches. A development batch of heaters was successfully fabricated based on the new process controls. Acceptance and cyclic life testing of multiple discharge and neutralizer sized heaters extracted from the development batch was initiated in August, 2016, with the last heater completing testing in April, 2017. Cyclic life testing results substantially exceeded the NEXT-C thruster requirement as well as all past experience for GRC-fabricated units. The heaters demonstrated ultimate cyclic life capability of 19050 to 33500 cycles. A qualification batch of heaters is now being fabricated using the finalized process controls. A set of six heaters will be acceptance and cyclic tested to verify conformance to the behavior observed with the development heaters. The heaters for flight use will be then be provided to the contractor from the remainder of the qualification batch. This paper summarizes the fabrication process control activities and the acceptance and life testing of the development heater units.

Thermal stratification in storage tanks of integrated collector storage solar water heaters

International Nuclear Information System (INIS)

Oshchepkov, M.Y.; Frid, S.E.

2015-01-01

To determine the influence of the shape of the tank, the installation angle, and the magnitude of the absorbed heat flux on thermal stratification in integrated collector-storage solar water heaters, numerical simulation of thermal convection in tanks of different shapes and same volume was carried out. Idealized two-dimensional models were studied; auto model stratification profiles were obtained at the constant heat flux. The shape of the tank, the pattern of the heat flux dynamics, the adiabatic mixing on the circulation rate and the degree of stratification were shown to have significant influence. (authors)

A thermodynamic analysis of a transcritical cycle with refrigerant mixture R32/R290 for a small heat pump water heater

Energy Technology Data Exchange (ETDEWEB)

Yu, Jianlin; Xu, Zong; Tian, Gaolei [Department of Refrigeration and Cryogenic Engineering, School of Energy and Power Engineering, Xi' an Jiaotong University, West Xianning Road, No. 28, Xianning West Road, Xi' an Shaanxi 710049 (China)

2010-12-15

In this study, a thermodynamic analysis on the performance of a transcritical cycle using azeotropic refrigerant mixtures of R32/R290 with mass fraction of 70/30 has been performed. The main purpose of this study is to theoretically verify the possibility of applying the chosen refrigerant mixture in small heat pumps for high temperature water heating applications. Performance evaluation has been carried out for a simple azeotropic mixture R32/R290 transcritical cycle by varying evaporator temperature, outlet temperature of gas cooler and compressor discharge pressure. Furthermore, the effects of an internal heat exchanger on the transcritical R32/R290 cycle have been presented at different operating conditions. The results show that high heating coefficient of performance (COP{sub h}) and volumetric heating capacity can be achieved by using this transcritical cycle. It is desirable to apply the chosen refrigerant mixture R32/R290 in small heat pump water heater for high temperature water heating applications, which may produce hot water with temperature up to 90 C. (author)

Geographic variation of solar water performance in Europe

Energy Technology Data Exchange (ETDEWEB)

Yohanis, Y. [University of Ulster (United Kingdom). Faculty of Engineering; Popel, O.; Frid, S. [Russian Academy of Sciences, Moscow (Russian Federation). Institute for High Temperatures; Norton, B. [Dublin Institute of Technology (Ireland)

2006-07-01

Solar water heater (SWH) performance has been analysed using the 'number of days' method for 147 different sites in all European countries. The total number of days that the temperature of delivered solar heated water reaches or exceeds specified demand temperatures is correlated with solar radiation on a horizontal surface for summer, warm half-year, and whole year periods. Maps are presented and discussed showing the contours for the number of days that an illustrative SWH met different hot water demand temperatures. Correlations between number of days water is provided at a specified temperature and solar fractions for the same periods are determined. (author)

Assessment of global environmental impacts by utilizing methodology of LCA on solar water heater for dwellings; LCA shuho ni yoru taiyonetsu onsuiki no kankyo fuka hyoka

Energy Technology Data Exchange (ETDEWEB)

Kamoshida, J [Shibaura Institute of Technology, Tokyo (Japan); Asai, S [Yazaki Corp., Tokyo (Japan)

1997-11-25

CO2 emission was quantified through the life cycle of a solar water heater to assess its environment impact. Although LCA (life cycle assessment) originally sums up I/O of all materials and energy through the whole life cycle of a product to examine environment impact, this assessment was carried out for only CO2. Calculation of CO2 emission assumed a natural circulating solar water heater of 200 l in effective hot water capacity, 2.78m{sup 2} in effective collecting area, and 0.5 in average annual collecting efficiency of total solar radiation, and an auxiliary city gas heat source for compensating insufficient heat quantity. The total CO2 emission in the life cycle of a solar water heater was obtained from an industrial association table assuming the life cycles of 10 and 20 years. CO2 emission was estimated to be 5407.1kg-CO2 and 10665.2kg-CO2 for 10 and 20 years, respectively. CO2 emission due to city gas was largest in the total CO2 emission in the life cycle. As a result, for reduction of CO2 emission due to a solar water heater, improvement of equipment efficiency was most important. 6 refs., 5 figs., 3 tabs.

Study of an improved integrated collector-storage solar water heater combined with the photovoltaic cells

International Nuclear Information System (INIS)

Ziapour, Behrooz M.; Palideh, Vahid; Mohammadnia, Ali

2014-01-01

Highlights: • Simulation of an enhanced ICSSWH system combined with PV panel was conducted. • The present model dose not uses any photovoltaic driven water pump. • High packing factor and tank water mass are caused to high PVT system efficiency. • Larger area of the collector is resulted to lower total PVT system efficiency. - Abstract: A photovoltaic–thermal (PVT) module is a combination of a photovoltaic (PV) panel and a thermal collector for co-generation of heat and electricity. An integrated collector-storage solar water heater (ICSSWH) system, due to its simple and compact structure, offers a promising approach for the solar water heating in the varied climates. The combination of the ICSSWH system with a PV solar system has not been reported. In this paper, simulation of an enhanced ICSSWH system combined with the PV panel has been conducted. The proposed design acts passive. Therefore, it does not use any photovoltaic driven water pump to maintain a flow of water inside the collector. The effects of the solar cell packing factor, the tank water mass and the collector area on the performance of the present PVT system have been investigated. The simulation results showed that the high solar cell packing factor and the tank water mass are caused to the high total PVT system efficiency. Also, larger area of the collector is resulted to lower total PVT system efficiency

Exergetic performance evaluation of a single pass baffled solar air heater

International Nuclear Information System (INIS)

Sabzpooshani, M.; Mohammadi, K.; Khorasanizadeh, H.

2014-01-01

In this study, the exergetic performance of a baffled type solar air heater has been evaluated theoretically. A detailed parametric study was done to investigate the effect of variation of fin and baffle parameters, number of glass covers, bottom insulation thickness and inlet air temperature at different mass flow rates on the exergy efficiency. The results indicated that attaching fins and baffles at low mass flow rates can lead to noticeable enhancement of the exergy efficiency. The results revealed that the trend of variation of the energy and exergy efficiencies are not the same and the exergy efficiency is the chief criterion for performance evaluation. Increasing the baffles width, reducing the distance between baffles and increasing the number of fins are effective at low mass flow rates, but at high mass flow rates the inverse trend is observable, such that exergy efficiency reduces sharply. The results showed that exergy efficiency increases with increasing the solar radiation intensity. By adding the second glass cover the exergy efficiency enhances at low mass flow rates. Increasing the insulation thickness over an optimum value doesn't improve the exergy efficiency. Increasing the inlet air temperature increases the exergy efficiency especially at high mass flow rates. - Highlights: • We study the exergetic performance of an upward type baffled solar air heater. • The effect of several design parameters on the performance is investigated. • Exergetic performance is very sensitive to the variation of baffles parameters. • Adding fins and baffles and increasing their parameters are efficient at low m . . • At high m . increment of baffles parameters causes decline of the exergy efficiency

Experimental validation of dynamic simulation of the flat plate collector in a closed thermosyphon solar water heater

DEFF Research Database (Denmark)

Taherian, H.; Kolaei, Alireza Rezania; Sadeghi, S.

2011-01-01

This work studies the dynamic simulation of thermosyphon solar water heater collector considering the weather conditions of a city in north of Iran. The simulation was done for clear and partly cloudy days. The useful energy, the efficiency diagrams, the inlet and the outlet of collector, center...

Vol. 34 - Optimization of quench protection heater performance in high-field accelerator magnets through computational and experimental analysis

CERN Document Server

Salmi, Tiina

2016-01-01

Superconducting accelerator magnets with increasingly hi gh magnetic fields are being designed to improve the performance of the Large Hadron Collider (LHC) at CERN. One of the technical challenges is the magnet quench p rotection, i.e., preventing damage in the case of an unexpected loss of superc onductivity and the heat generation related to that. Traditionally this is d one by disconnecting the magnet current supply and using so-called protection he aters. The heaters suppress the superconducting state across a large fraction of the winding thus leading to a uniform dissipation of the stored energy. Preli minary studies suggested that the high-field Nb 3 Sn magnets under development for the LHC luminosity upgrade (HiLumi) could not be reliably protected using the existing heaters. In this thesis work I analyzed in detail the present state-of-the-art protection heater technology, aiming to optimize its perfo rmance and evaluate the prospects in high-field magnet protection. The heater efficiency analyses ...

Evaluation method for two-phase flow and heat transfer in a feed-water heater

International Nuclear Information System (INIS)

Takamori, Kazuhide; Minato, Akihiko

1993-01-01

A multidimensional analysis code for two-phase flow using a two-fluid model was improved by taking into consideration the condensation heat transfer, film thickness, and film velocity, in order to develop an evaluation method for two-phase flow and heat transfer in a feed-water heater. The following results were obtained by a two-dimensional analysis of a feed-water heater for a power plant. (1) In the model, the film flowed downward in laminar flow due to gravity, with droplet entrainment and deposition. For evaluation of the film thickness, Fujii's equation was used in order to account for forced convection of steam flow. (2) Based on the former experimental data, the droplet deposition coefficient and droplet entrainment rate of liquid film were determined. When the ratio at which the liquid film directly flowed from an upper heat transfer tube to a lower heat transfer tube was 0.7, the calculated total heat transfer rate agreed with the measured value of 130 MW. (3) At the upper region of a heat transfer tube bundle where film thickness was thin, and at the outer region of a heat transfer tube bundle where steam velocity was high, the heat transfer rate was large. (author)

Device Performance Improvement of Double-Pass Wire Mesh Packed Solar Air Heaters under Recycling Operation Conditions

Directory of Open Access Journals (Sweden)

Chii-Dong Ho

2016-01-01

Full Text Available The improvement of device performance of a recycling solar air heater featuring a wire mesh packing was investigated experimentally and theoretically. The application of the wire mesh packing and recycle-effect concept to the present study were proposed aiming to strengthen the convective heat-transfer coefficient due to increased turbulence. Comparisons were made among different designs, including the single-pass, flat-plate double-pass and recycling double-pass wire mesh packed operations. The collector efficiency of the recycling double-pass wire mesh packed solar air heater was much higher than that of the other configurations for various recycle ratios and mass flow rates scenarios. The power consumption increment due to implementing wire mesh in solar air heaters was also discussed considering the economic feasibility. A fairly good agreement between theoretical predictions and experimental measurements was achieved with an analyzed error of 1.07%–9.32%.

Test of two heat-pump systems, Fre-Heater Type B and Fre-Heater Type C, made by Mueller. Installations for the cooling of milk and the heating of water on farms. Beproeving van twee warmtepompsystemen, type Fre-Heater, modellen B en C, fabrikaat Mueller. Installaties voor het koelen van melk en het verwarmen van water op de boerderij

Energy Technology Data Exchange (ETDEWEB)

Bouman, S; Verheij, C P; de Vries, J

1980-01-01

At the request of Meko Holland BV, Assen (the Netherlands), two heat-pump systems, Fre-Heater Type B and Fre-Heater Type C (FH-B and FH-C), were tested for their suitability for the simultaneous cooling of milk and heating of water on farms. The main purpose of the tests was to provide information about the technical properties of the systems, and about the possibilities they offer for the saving of energy. The test was carried out according to the directives laid down in the 'Beproevingsmethoden voor warmtepompsystemen ten behoeve van het verwarmen van water op de boerderij' (Test methods for heat-pump systems for the heating of water on farms), issued by the Netherlands Institute for Dairy Research, 1980. Both systems were compared with a conventional air-cooled refrigerated farm milk tank with a COPR (coefficient of performance of refrigeration) of 2.5. The FH-B was found to have a COPR of 2.25, and the FH-C a COPR of 2.52. The net savings of energy that could be achieved with the FH-B were 16.8 kWh per m3 cooled 'milk', and with the FH-C 17.2 kWh per m3 cooled 'milk'. Based on a pay-back period of five years and a price of electrical energy of Dfl 0.20 per kWh, the FH-B appeared to be economically justified at a farm with 38 cows and the FH-C at a farm with 48 cows (milk production 5.5 m3 per cow per year).

Forced-circulation solar water heater using a solar battery; Taiyo denchi wo mochiita kyosei junkanshiki taiyonetsu onsuiki

Energy Technology Data Exchange (ETDEWEB)

Asai, S; Mizuno, T [Yazaki Resources Co. Ltd., Shizuoka (Japan)

1996-10-27

For the purpose of satisfying demands for qualitative improvement on tapwater temperature and pressure, an indirect-type solar water heater using solar cells, in which a closed type hot water storage tank connected directly to the water supply is integrated with a solar collector, was examined for its characteristics and performance. The heat collecting medium is a water solution of polypropylene glycol, which circulates through the solar collector pump, cistern, solar collector, and heat exchanger (hot water storage tank). The results of the test are summarized below. When comparison is made between the two solar collector pump control methods, the solar cells direct connection method and the differential thermo method utilizing temperature difference between the solar collector and the hot water storage tank, they are alike in collecting heat on clear days, but on cloudy days the latter collects 5% more than the former. In winter, when the heat exchanger heat transfer area is 0.4m{sup 2} large, a further increase in the area improves but a little the heat collecting efficiency. An increase in the medium flow rate and temperature, or in the Reynolds number, enhances the heat collecting efficiency. 13 figs., 6 tabs.

Thermal behaviour of solar air heater with compound parabolic concentrator

International Nuclear Information System (INIS)

Tchinda, Rene

2008-01-01

A mathematical model for computing the thermal performance of an air heater with a truncated compound parabolic concentrator having a flat one-sided absorber is presented. A computer code that employs an iterative solution procedure is constructed to solve the governing energy equations and to estimate the performance parameters of the collector. The effects of the air mass flow rate, the wind speed and the collector length on the thermal performance of the present air heater are investigated. Predictions for the performance of the solar heater also exhibit reasonable agreement, with experimental data with an average error of 7%

One dimensional analysis model for condensation heat transfer in feed water heater

International Nuclear Information System (INIS)

Murase, Michio; Takamori, Kazuhide; Aihara, Tsuyoshi

1998-01-01

In order to simplify condensation heat transfer calculations for feed water heaters, one dimensional (1D) analyses were compared with three dimensional (3D) analyses. The results showed that average condensation heat transfer coefficients by 1D analyses with 1/2 rows of heat transfer tubes agreed with those by 3D analyses within 7%. Using the 1D analysis model, effects of the pitch of heat transfer tubes were evaluated. The results showed that the pitch did not affect much on heat transfer rates and that the size of heat transfer tube bundle could be decreased by a small pitch. (author)

Studies in biogas technology. Part 4. A noval biogas plant incorporating a solar water-heater and solar still

Energy Technology Data Exchange (ETDEWEB)

Reddy, A K.N. [Indian Inst. of Science, Bangalore; Prasad, C R; Sathyanarayan, S R.C.; Rajabapaiah, P

1979-09-01

A reduction in the heat losses from the top of the gas holder of a biogas plant has been achieved by the simple device of a transparent cover. The heat losses thus prevented have been deployed to heat a water pond formed on the roof of the gas holder. This solar-heated water is mixed with the organic input for hot-charging of the biogas plant. To test whether the advantages indicated by a thermal analysis can be realized in practice, a biogas plant of the ASTRA design was modified to incorporate a roof-top water-heater. The operation of such a modified plant, even under worst case conditions, shows a significant improvement in the gas yield compared to the unmodified plant. Hence, the innovation reported here may lead to drastic reductions in the sizes and therefore costs of biogas plants. By making the transparent cover assume a tent-shape, the roof-top solar heater can serve the additional function of a solar still to yield distilled water. The biogas plant-cum-solar still described here is an example of a spatially integrated hybrid device which is extremely cost-effective.

A hybrid desalination system using humidification-dehumidification and solar stills integrated with evacuated solar water heater

International Nuclear Information System (INIS)

Sharshir, S.W.; Peng, Guilong; Yang, Nuo; Eltawil, Mohamed A.; Ali, Mohamed Kamal Ahmed; Kabeel, A.E.

2016-01-01

Highlights: • Evacuated solar water heater integrated with humidification-dehumidification system. • Reuse of warm water drained from humidification-dehumidification to feed solar stills. • The thermal performance of hybrid system is increased by 50% and maximum yield is 63.3 kg/day. • The estimated price of the freshwater produced from the hybrid system is $0.034/L. - Abstract: This paper offers a hybrid solar desalination system comprising a humidification-dehumidification and four solar stills. The developed hybrid desalination system reuses the drain warm water from humidification-dehumidification to feed solar stills to stop the massive warm water loss during desalination. Reusing the drain warm water increases the gain output ratio of the system by 50% and also increased the efficiency of single solar still to about 90%. Furthermore, the production of a single solar still as a part of the hybrid system was more than that of the conventional one by approximately 200%. The daily water production of the conventional one, single solar still, four solar still, humidification- dehumidification and hybrid system were 3.2, 10.5, 42, 24.3 and 66.3 kg/day, respectively. Furthermore, the cost per unit liter of distillate from conventional one, humidification- dehumidification and hybrid system were around $0.049, $0.058 and $0.034, respectively.

Extreme learning machine: a new alternative for measuring heat collection rate and heat loss coefficient of water-in-glass evacuated tube solar water heaters.

Science.gov (United States)

Liu, Zhijian; Li, Hao; Tang, Xindong; Zhang, Xinyu; Lin, Fan; Cheng, Kewei

2016-01-01

Heat collection rate and heat loss coefficient are crucial indicators for the evaluation of in service water-in-glass evacuated tube solar water heaters. However, the direct determination requires complex detection devices and a series of standard experiments, wasting too much time and manpower. To address this problem, we previously used artificial neural networks and support vector machine to develop precise knowledge-based models for predicting the heat collection rates and heat loss coefficients of water-in-glass evacuated tube solar water heaters, setting the properties measured by "portable test instruments" as the independent variables. A robust software for determination was also developed. However, in previous results, the prediction accuracy of heat loss coefficients can still be improved compared to those of heat collection rates. Also, in practical applications, even a small reduction in root mean square errors (RMSEs) can sometimes significantly improve the evaluation and business processes. As a further study, in this short report, we show that using a novel and fast machine learning algorithm-extreme learning machine can generate better predicted results for heat loss coefficient, which reduces the average RMSEs to 0.67 in testing.

Natural convection in a parallel-plate vertical channel with discrete heating by two flush-mounted heaters: effect of the clearance between the heaters

Science.gov (United States)

Sarper, Bugra; Saglam, Mehmet; Aydin, Orhan; Avci, Mete

2018-04-01

In this study, natural convection in a vertical channel is studied experimentally and numerically. One of the channel walls is heated discretely by two flush-mounted heaters while the other is insulated. The effects of the clearance between the heaters on heat transfer and hot spot temperature while total length of the heaters keeps constant are investigated. Four different settlements of two discrete heaters are comparatively examined. Air is used as the working fluid. The range of the modified Grashof number covers the values between 9.6 × 105 and 1.53 × 10.7 Surface to surface radiation is taken into account. Flow visualizations and temperature measurements are performed in the experimental study. Numerical computations are performed using the commercial CFD code ANSYS FLUENT. The results are represented as the variations of surface temperature, hot spot temperature and Nusselt number with the modified Grashof number and the clearance between the heaters as well as velocity and temperature variations of the fluid.

Fire-tube immersion heater optimization program and field heater audit program

Energy Technology Data Exchange (ETDEWEB)

Croteau, P. [Petro-Canada, Calgary, AB (Canada)

2007-07-01

This presentation provided an overview of the top 5 priorities for emission reduction and eco-efficiency by the Petroleum Technology Alliance of Canada (PTAC). These included venting of methane emissions; fuel consumption in reciprocating engines; fuel consumption in fired heaters; flaring and incineration; and fugitive emissions. It described the common concern for many upstream operating companies as being energy consumption associated with immersion heaters. PTAC fire-tube heater and line heater studies were presented. Combustion efficiency was discussed in terms of excess air, fire-tube selection, heat flux rate, and reliability guidelines. Other topics included heat transfer and fire-tube design; burner selection; burner duty cycle; heater tune up inspection procedure; and insulation. Two other programs were also discussed, notably a Petro-Canada fire-tube immersion heater optimization program and the field audit program run by Natural Resources Canada. It was concluded that improved efficiency involves training; managing excess air in combustion; managing the burner duty cycle; striving for 82 per cent combustion efficiency; and providing adequate insulation to reduce energy demand. tabs., figs.

Guidebook for the Development of a Nationally Appropriate Mitigation Action for Solar Water Heaters

DEFF Research Database (Denmark)

Haselip, James Arthur; Lütken, Søren E.; Sharma, Sudhir

This guidebook provides an introduction to designing government-led interventions to scale up investment in solar water heater (SWH) markets, showing how these interventions can be packaged as Nationally Appropriate Mitigation Actions (NAMAS). Reflecting the changing balance in global greenhouse...... gas emissions, NAMAs embody the principle of common but differentiated responsibilities. In addition to developed countries’ commitments to make quantitative reductions of greenhouse gas emissions, developing countries are invited to contribute with voluntary actions that are ‘nationally appropriate...

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.

Householders' use of storage heaters

Energy Technology Data Exchange (ETDEWEB)

Crawshaw, C M; Williams, D I; Steele, L M

1986-11-01

An investigation into the understanding and use of storage heater controls was carried out. The general level of satisfaction with storage heating was high (90%) and most people had a reasonable idea of how the system works, what the controls do and of the tariff costs. However, the study did find substantial areas of ignorance; 37% could not say what controls their heater had and 15% did not know what tariff they were on. This lack of knowledge may prevent users getting the best performance from their heating system, resulting in discomfort and large bills.

Performance analysis of solar air heater with jet impingement on corrugated absorber plate

Directory of Open Access Journals (Sweden)

Alsanossi M. Aboghrara

2017-09-01

Full Text Available This paper deals with the experimental investigation outlet temperature and efficiency, of Solar Air heater (SAH. The experimental test set up designed and fabricated to study the effect of jet impingement on the corrugated absorber plate, through circular jets in a duct flow of solar air heater, and compared with conventional solar air heater on flat plat absorber. Under effect of mass flow rate (ṁ of air and solar radiation on outlet air temperature, and efficiency, are analyzed. Results show the flow jet impingement on corrugated plat absorber is a strong function of heat transfer enhancement. The present investigation concludes that the mass flow rate of air substantially influences the heat transfer on solar air heaters. And the thermal efficiency of proposed design duct is observed almost 14% more as compare to the smooth duct. At solar radiation 500–1000 (W/M2, 308 K ambient temperature and 0.01–0.03 (Kg/S mass flow rate

The potential and reality of the solar water heater programme in South African townships: Lessons from the City of Tshwane

International Nuclear Information System (INIS)

Curry, Claire; Cherni, Judith A.; Mapako, Maxwell

2017-01-01

The South African solar water heater (SWH) programme is part of national policy to improve the country's electricity security, an innovative strategy to provide indigent households with free solar water heaters. The study assesses the effects of the government programme for poor townships on reduction of household electricity consumption, decline in energy poverty, and reduction in CO2 emissions; and estimates the impact of SWH on reducing electricity demand nationwide. It reports results from fieldwork carried out in the City of Tshwane to measure both quantitatively and qualitatively the success of the project's deployment in townships. Although households register average savings of 27% on their monthly electricity bills and off-peak electricity demand has reduced significantly in the area, a variety of problems prevented the project from attaining the desired level of impact. Difficulties encountered include technical faults with the heaters combined with nonavailability of maintenance; a rise in water consumption; lack of community engagement leading to apathy; and dearth of owner training leading to underuse. The gap between inflated estimates and real savings is discussed. Expanding the programme could generate jobs but significant challenges remain. - Highlights: • The government's aim of saving electricity and reducing utility bills partly achieved. • Savings of electricity are estimated at about 25% less than the potential saving. • Wrong assumption that peak time is only 1 h produced savings 5 times larger. • ESKOM & government overlooked providing Information on the SWH to the householders. • No maintenance led to abandonment by many or water leaking increasing utility bills.

Performance study of solar air heater duct having absorber plate with V down perforated baffles

Directory of Open Access Journals (Sweden)

Sunil Chamoli

2014-04-01

Full Text Available This paper presents results of a study of the performance of solar air heaters with V down perforated baffles as roughness on the air flow side of the absorber plate. Investigations have been carried out using a mathematical model to study the effects of ambient conditions, operating and design parameters on effective efficiency of such air heaters. The thermal and effective efficiencies differ only marginally at lower flow rates. With an increase in the flow rate, the difference between the thermal and effective efficiencies increases because of the increase in the pumping power. The results of the study are presented in the form of plots to show the effect of ambient, design and operating conditions on thermal and effective efficiency.

Analysis of solar water heater with parabolic dish concentrator and conical absorber

Science.gov (United States)

Rajamohan, G.; Kumar, P.; Anwar, M.; Mohanraj, T.

2017-06-01

This research focuses on developing novel technique for a solar water heating system. The novel solar system comprises a parabolic dish concentrator, conical absorber and water heater. In this system, the conical absorber tube directly absorbs solar radiation from the sun and the parabolic dish concentrator reflects the solar radiations towards the conical absorber tube from all directions, therefore both radiations would significantly improve the thermal collector efficiency. The working fluid water is stored at the bottom of the absorber tubes. The absorber tubes get heated and increases the temperature of the working fluid inside of the absorber tube and causes the working fluid to partially evaporate. The partially vaporized working fluid moves in the upward direction due to buoyancy effect and enters the heat exchanger. When fresh water passes through the heat exchanger, temperature of the vapour decreases through heat exchange. This leads to condensation of the vapour and forms liquid phase. The working fluid returns to the bottom of the collector absorber tube by gravity. Hence, this will continue as a cyclic process inside the system. The proposed investigation shows an improvement of collector efficiency, enhanced heat transfer and a quality water heating system.

To built a solar hot water heater to work the sustainability problem

Directory of Open Access Journals (Sweden)

Carretero Gómez, María Begoña

2012-01-01

Full Text Available We are commemorating the Education Decade for Sustainable Development. If we want to create positive towards our environment and its sustainable development we have to begin working at school. It is necessary to show our students what problems of the environment are and which solutions can be adopted. That is the reason we have planned this activity in our secondary school. We do think that by doing daily activities we have a good opportunity to fulfil this goal. An example of such experiences is the fabrication of a solar hot water heater to make them and their families more environment conscience.

Enhancing the solar still using immersion type water heater productivity and the effect of external cooling fan in winter

International Nuclear Information System (INIS)

Al-Garni, Ahmed Z.

2012-01-01

In the present work an attempt is made to enhance the of double slope solar still productivity by an immersion type water heater using. The effect of using an external fan to cool the glass surface is also examined. Experiments were carried out for winter season in Saudi Arabian climatic conditions at latitude 26 degree N. A solar still with 35 degree glass slope angle is chosen in our study. Since the yield of a solar still is more for low water depths, the water level in the base tank was maintained at 1 cm. The experimental results showed that the productivity increased by a significant 370% when two water heaters each having 500 W capacities was used. When external cooling fan was used the productivity was found to decrease by 4 % and 8% for wind speeds of 7 m/s and 9 m/s respectively. Thermal modeling was also done by the heat and mass transfer relations using, and then numerical simulations were carried out to validate with the experimental results. A good agreement between experimental and numerical results was found. The present study is partial implementation of two patents submitted in this field. (authors)

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

Experimental study on depth of paraffin wax over floating absorber plate in built-in storage solar water heater

Directory of Open Access Journals (Sweden)

R Sivakumar

2015-11-01

Full Text Available The aim of this article is to study the effect of depth of phase change material over the absorber surface of an integrated collector-storage type flat plate solar water heater. Flat plate solar water heaters are extensively used all over the world to utilize the natural source of solar energy. In order to utilize the solar energy during off-sunshine hours, it is inevitable to store and retain solar thermal energy as long as possible. Here, phase change material is not used for heat storage, but to minimize losses during day and night time only. The depth of phase change material over a fixed depth of water in a solar thermal collector is an important geometric parameter that influences the maximum temperature rise during peak solar irradiation and hence the losses. From the results of the studies for different masses of paraffin wax phase change material layers, the optimum depth corresponding to the maximum heat gain till evening is found to be 2 mm, and the heat retention till the next day morning is found to be 4 mm.

Low-Temperature Baseboard Heaters in Built Environments

Energy Technology Data Exchange (ETDEWEB)

Ploskic, Adnan

2010-10-15

The European Union has adopted a plan to decrease 20 % of total energy consumption through improved energy efficiency by 2020. One way of achieving this challenging goal may be to use efficient water-based heating systems supplied by heat pumps or other sustainable systems. The goal of this research was to analyze and improve the thermal performance of water-based baseboard heaters at low-temperature water supply. Both numerical (CFD) and analytical simulations were used to investigate the heat efficiency of the system. An additional objective of this work was to ensure that the indoor thermal comfort was satisfied in spaces served by such a low-temperature heating system. Analyses showed that it was fully possible to cover both transmission and ventilation heat losses using baseboard heaters supplied by 45 deg C water flow. The conventional baseboards, however, showed problems in suppressing the cold air down-flow created by 2.0 m high glazing and an outdoor temperature of -12 deg C. The draught discomfort at ankle level was slightly above the upper limit recommended by international and national standards. On the other hand, thermal baseboards with integrated ventilation air supply showed better ability to neutralize cold downdraught at the same height and conditions. Calculations also showed that the heat output from the integrated system with one ventilation inlet was approximately twice as high as that of the conventional one. The general conclusion from this work was that low temperature baseboards, especially with integrated ventilation air supply, are an efficient heating system and able to be combined with devices that utilize the low-quality sustainable energy sources such as heat pumps

Performances of packed bed double pass solar air heater with different inclinations and transverse wire mesh with different intervals

Directory of Open Access Journals (Sweden)

Sugantharaj Gnanadurai Sam Stanley

2016-01-01

Full Text Available Solar air heating is a technology in which the solar energy from the sun is captured by an absorbing medium and used to heat the air flowing through the heater. In this study, thermal performance of a double pass solar air heater has been investigated experimentally at different conditions. The experiments were conducted with different inclinations of the collector, with and without wire mesh vertically fixed at the second pass in transverse direction and with different mass flow rates. The effect of air mass flow rate, wire mesh pitch and collector inclination on temperature rise and thermal efficiency have been studied. Results show that efficiency increases with mass flow rate. For the same mass flow rate, the thermal efficiency increases with the decrease in the wire mesh pitch. The maximum daily average efficiency of air heater was 79.8% at 0.025 kg/s mass flow rate, 10 cm wire mesh gap and 9º collector inclination facing south. The highest collector efficiency was observed in solar air heaters with 10 cm wire mesh gap.

Heater-Integrated Cantilevers for Nano-Samples Thermogravimetric Analysis

Science.gov (United States)

Toffoli, Valeria; Carrato, Sergio; Lee, Dongkyu; Jeon, Sangmin; Lazzarino, Marco

2013-01-01

The design and characteristics of a micro-system for thermogravimetric analysis (TGA) in which heater, temperature sensor and mass sensor are integrated into a single device are presented. The system consists of a suspended cantilever that incorporates a microfabricated resistor, used as both heater and thermometer. A three-dimensional finite element analysis was used to define the structure parameters. TGA sensors were fabricated by standard microlithographic techniques and tested using milli-Q water and polyurethane microcapsule. The results demonstrated that our approach provides a faster and more sensitive TGA with respect to commercial systems.

The Impact of Water Quality on the Use of Solar Water Heaters in Remote Islands of Taiwan

Directory of Open Access Journals (Sweden)

Kai-Chun Fan

2016-11-01

Full Text Available The use of solar water heaters (SWHs in Taiwan’s remote islands has been subjected to scaling and, in particular, corrosion problems due to sources of water. In this study, four different water quality indices including the Langelier Saturation Index (LSI, the Ryznar Stability Index (RSI, the Puckorius Scaling Index (PSI, and the Larson-Skold Corrosive Index (LSCI were employed to assess the scaling and corrosion tendencies in SWHs caused by tap water and ground water in the Penghu, Kinmen, and Lienchiang counties, each of which is constituted of several remote islands. In general, the LSI, the RSI, and the PSI results show a slight scaling tendency in Penghu, but a corrosion tendency in Kinmen and Lienchiang. Nevertheless, all LSCI results show a serious steel corrosion tendency in these three counties. In addition, the chloride ion (Cl− concentrations are higher than 45 mg/L in either tap water (except for the Lieyu township in Kinmen or ground water. This fact resulted in serious corrosion problems, as found in the currently installed SWHs, which were mainly made from 304 stainless steel. The metals with higher corrosion resistance to chloride ions are required in the manufacture of SWHs to be installed on these three remote-island counties.

Safety grade pressurizer heater power supply connector assembly

International Nuclear Information System (INIS)

Burnett, J.M.; Daftari, R.M.; Reyns, R.M.

1987-01-01

This patent describes a pressurizer heater power supply connector assembly for attaching a power cable to an electric heater within a pressurizer of a pressurized water nuclear reactor system, the electric heater having pin contacts. The assembly comprises: a pin-socket type connector including a tubular body having a first open end carrying a pin-socket contact member and an insert intermediate a shell and the pin-socket contact member, the contact member having socket means for electrically receiving and contacting the pin contacts, and a second open end; a flexible sealed conduit including a flexible corrugated tube having one end connected to the second open end of the pin-socket type connector, and another end; and a shop splice assembly including a header adapter and a hose clamp interconnected between the header adapter and another end of the flexible corrugated tube

Tube Plugging Criteria for the High-pressure Heaters of Nuclear Power Plant

Energy Technology Data Exchange (ETDEWEB)

Kim, Hyungnam; Cho, Nam-Cheoul; Lee, Kuk-hee [KHNP Central Research Institute, Daejeon (Korea, Republic of)

2015-10-15

In this paper, a method to establish the tube plugging criteria of BOP heat exchangers is introduced and the tube plugging criteria for the high pressure heaters of a nuclear power plant. This method relies on the similar plugging criteria used in the steam generator tubes. Power generation field urges nuclear power plants to reduce operating and maintaining costs to remain competitive. To reduce the cost by means of preventing the lowering thermal efficiency, the inspection of balance-of-plant heat exchanger, which was treated as not important work, becomes important. The tubing materials and tube thickness of heat exchangers in nuclear power plants are selected to withstand system temperature, pressure, and corrosion. But tubes have experienced leaks and failures and plugged based upon eddy current testing (ET) results. There are some problems for plugging the heat exchanger tubes since the criterion and its basis are not clearly described. For this reason, the criteria for the tube wall thickness are addressed in order to operate the heat exchangers in nuclear power plant without trouble during the cycle. The feed water heater is a kind of heat exchanger which raises the temperature of water supplied from the condenser. The heat source of high-pressure heaters is the extraction steam from the high-pressure turbine and moisture separator re-heater. If the tube wall of the heater is broken, the feed water flowing inside the tube intrudes to shell side. This forces the turbine to be stop in order to protect it. There are many codes and standards to be referred for calculating the minimum thickness of the heat exchanger tube in the designing stage. However, the codes and standards related to show the tube plugging criteria may not exist currently. A method to establish the tube plugging criteria of BOP heat exchangers is introduced and the tube plugging criteria for the high pressure heaters of Ulchin NPP No. 3 and 4. This method relies on the similar plugging

Application of CAE-modeling for the study of the influence of the sensor location on the flow-through water heater operation

Science.gov (United States)

Yakunin, A. G.

2018-01-01

The article deals with issues related to increasing the efficiency of the system of automatic maintenance of the temperature of liquid media entering the pipes to the place of consumption. For this purpose, a flowing water heater model is proposed, made in the SolidWorks environment, the construction parameters of which can be changed using the appropriate macro and screen form. It is shown that the choice of the location of the temperature sensor has a significant effect on such parameters of the device as the accuracy of maintaining a given temperature regime and the duration of the transient process caused by a change in the temperature of the liquid entering the heater. On a concrete example, it is shown that by changing the distance between the sensor and the heating module, it is possible to achieve minimum temperature fluctuations of the heat-transfer-agent at the heater outlet.

Local market of solar water heaters in Taiwan. Review and perspectives

International Nuclear Information System (INIS)

Chang, K.C.; Lee, T.S.; Chung, K.M.; Lin, W.M.

2009-01-01

For promotion of solar water heaters in Taiwan, incentive programs were first initiated from 1986 to 1991 and re-initiated from 2000 to the present. The subsidies create an economic incentive for the end users and have been rather instrumental at the initial stage of each program but lost their significance thereafter. To analyze the behavior of the major actors in the local market, two questionnaires were developed. One was addressed to sales and distribution agents while the other one consisted of person-to-person interviews with household owners. The market-driven mechanism is a multi-parametric phenomenon. Other than the capital cost and energy price (cost to benefit), architectural type of buildings (or degree of urbanization) and household composition play the major roles in market diffusion. (author)

Low cost solar air heater

International Nuclear Information System (INIS)

Gill, R.S.; Singh, Sukhmeet; Singh, Parm Pal

2012-01-01

Highlights: ► Single glazed low cost solar air heater is more efficient during summer while double glazed is better in winter. ► For the same initial investment, low cost solar air heaters collect more energy than packed bed solar air heater. ► During off season low cost solar air heater can be stored inside as it is light in weight. - Abstract: Two low cost solar air heaters viz. single glazed and double glazed were designed, fabricated and tested. Thermocole, ultraviolet stabilised plastic sheet, etc. were used for fabrication to reduce the fabrication cost. These were tested simultaneously at no load and with load both in summer and winter seasons along with packed bed solar air heater using iron chips for absorption of radiation. The initial costs of single glazed and double glazed are 22.8% and 26.8% of the initial cost of packed bed solar air heater of the same aperture area. It was found that on a given day at no load, the maximum stagnation temperatures of single glazed and double glazed solar air heater were 43.5 °C and 62.5 °C respectively. The efficiencies of single glazed, double glazed and packed bed solar air heaters corresponding to flow rate of 0.02 m 3 /s-m 2 were 30.29%, 45.05% and 71.68% respectively in winter season. The collector efficiency factor, heat removal factor based on air outlet temperature and air inlet temperature for three solar air heaters were also determined.

Infrared transparent graphene heater for silicon photonic integrated circuits.

Science.gov (United States)

Schall, Daniel; Mohsin, Muhammad; Sagade, Abhay A; Otto, Martin; Chmielak, Bartos; Suckow, Stephan; Giesecke, Anna Lena; Neumaier, Daniel; Kurz, Heinrich

2016-04-18

Thermo-optical tuning of the refractive index is one of the pivotal operations performed in integrated silicon photonic circuits for thermal stabilization, compensation of fabrication tolerances, and implementation of photonic operations. Currently, heaters based on metal wires provide the temperature control in the silicon waveguide. The strong interaction of metal and light, however, necessitates a certain gap between the heater and the photonic structure to avoid significant transmission loss. Here we present a graphene heater that overcomes this constraint and enables an energy efficient tuning of the refractive index. We achieve a tuning power as low as 22 mW per free spectral range and fast response time of 3 µs, outperforming metal based waveguide heaters. Simulations support the experimental results and suggest that for graphene heaters the spacing to the silicon can be further reduced yielding the best possible energy efficiency and operation speed.

Performance evaluation of a natural-convection solar air-heater with a rectangular-finned absorber plate

International Nuclear Information System (INIS)

Fakoor Pakdaman, M.; Lashkari, A.; Basirat Tabrizi, H.; Hosseini, R.

2011-01-01

This paper deals with an experimental investigation to evaluate different thermal characteristics of a natural-convection flat-plate solar air-heater with longitudinal rectangular fins array. Having determined the thermal performance of the system a Nusselt number correlation is presented for such finned duct devices. In the presented empirical model which may have industrial applications, solar radiation and ambient temperature have been considered as independent parameters. Other characteristics of the system such as different dimensionless variables, plates and outflow temperatures, efficiency, and mass flow rate have been empirically modeled based on these variables. The particular difference in this study in comparison with the other similar studies is the presentation of an empirical model for rectangular-finned solar air-heaters. This model proposes design concepts and rules of thumb, and demonstrates the calculations of the design parameters. Based on the order of magnitude analysis, solar radiation has been found to be the main parameter which characterizes the thermal behavior of the system. Besides, exergy analysis has been carried out, and optimum conditions in which the system has the highest performance have been determined.

Thermal behaviour of a solar air heater with a compound parabolic concentrator

International Nuclear Information System (INIS)

Tchinda, R.

2005-11-01

A mathematical model for computing the thermal performance of an air heater with a truncated compound parabolic concentrator having a flat one-sided absorber is presented. A computed code that employs an iterative solution procedure is constructed to solve the governing energy equations and to estimate the performance parameters of the collector. The effects of the air mass flow rate, the wind speed and the collector length on the thermal performance of the present air heater are investigated. Prediction for the performance of the solar heater also exhibits reasonable agreement with experimental data with an average error of 7%. (author)

Thermal Performance of Solar Air Heater Having Absorber Plate with V-Down Discrete Rib Roughness for Space-Heating Applications

Directory of Open Access Journals (Sweden)

Rajendra Karwa

2013-01-01

Full Text Available The paper presents results of thermal performance analysis of a solar air heater with v-down discrete rib roughness on the air flow side of the absorber plate, which supplies heated air for space heating applications. The air heater operates in a closed loop mode with inlet air at a fixed temperature of 295 K from the conditional space. The ambient temperature varied from 278 K to 288 K corresponding to the winter season of Western Rajasthan, India. The results of the analysis are presented in the form of performance plots, which can be utilized by a designer for calculating desired air flow rate at different ambient temperature and solar insolation values.

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.

Test design requirements: Canister-scale heater test

International Nuclear Information System (INIS)

Schauer, M.I.; Craig, P.A.; Stickney, R.G.

1986-03-01

This document establishes the Test Design Requirements for the design of a canister scale heater test to be performed in the Exploratory Shaft test facility. The purpose of the test is to obtain thermomechanical rock mass response data for use in validation of the numerical models. The canister scale heater test is a full scale simulation of a high-level nuclear waste container in a prototypic emplacement borehole. Electric heaters are used to simulate the heat loads expected in an actual waste container. This document presents an overview of the test including objectives and justification for the test. A description of the test as it is presently envisioned is included. Discussions on Quality Assurance and Safety are also included in the document. 12 refs., 1 fig

Immersible solar heater for fluids

Science.gov (United States)

Kronberg, James W.

1995-01-01

An immersible solar heater comprising a light-absorbing panel attached to a frame for absorbing heat energy from the light and transferring the absorbed heat energy directly to the fluid in which the heater is immersed. The heater can be used to heat a swimming pool, for example, and is held in position and at a preselected angle by a system of floats, weights and tethers so that the panel can operate efficiently. A skid can be used in one embodiment to prevent lateral movement of the heater along the bottom of the pool. Alternative embodiments include different arrangements of the weights, floats and tethers and methods for making the heater.

Microcontroller based instrumentation for heater control circuit of tin oxide based hydrogen sensor

International Nuclear Information System (INIS)

Premalatha, S.; Krithika, P.; Gunasekaran, G.; Ramakrishnan, R.; Ramanarayanan, R.R.; Prabhu, E.; Jayaraman, V.; Parthasarathy, R.

2015-01-01

A thin film sensor based on tin oxide developed in IGCAR is used to monitor very low levels of hydrogen (concentration ranging from 2 ppm to 80 ppm). The heater and the sensor patterns are integrated on a miniature alumina substrate and necessary electrical leads are taken out. For proper functioning of the sensor, the heater has to be maintained at a constant temperature of 350°C. The sensor output (voltage signal) varies with H 2 concentration. In fast breeder reactors, liquid sodium is used as coolant. The sensor is used to detect water/steam leak in secondary sodium circuit. During the start up of the reactor, steam leak into sodium circuit generates hydrogen gas as a product that doesn't dissolve in sodium, but escapes to the surge tank containing argon i.e. in cover gas plenum of sodium circuit. On-line monitoring of hydrogen in cover gas is done to detect an event of water/steam leakage. The focus of this project is on the instrumentation pertaining to the temperature control for the sensor heater. The tin oxide based hydrogen sensor is embedded in a substrate which consists of a platinum heater, essentially a resistor. There is no provision of embedding a temperature sensor on the heater surface due to the physical constraints, without which maintaining a constant heater temperature is a complex task

Heater-Integrated Cantilevers for Nano-Samples Thermogravimetric Analysis

Directory of Open Access Journals (Sweden)

Valeria Toffoli

2013-12-01

Full Text Available The design and characteristics of a micro-system for thermogravimetric analysis (TGA in which heater, temperature sensor and mass sensor are integrated into a single device are presented. The system consists of a suspended cantilever that incorporates a microfabricated resistor, used as both heater and thermometer. A three-dimensional finite element analysis was used to define the structure parameters. TGA sensors were fabricated by standard microlithographic techniques and tested using milli-Q water and polyurethane microcapsule. The results demonstrated that our approach provides a faster and more sensitive TGA with respect to commercial systems.

A silicon nanowire heater and thermometer

Science.gov (United States)

Zhao, Xingyan; Dan, Yaping

2017-07-01

In the thermal conductivity measurements of thermoelectric materials, heaters and thermometers made of the same semiconducting materials under test, forming a homogeneous system, will significantly simplify fabrication and integration. In this work, we demonstrate a high-performance heater and thermometer made of single silicon nanowires (SiNWs). The SiNWs are patterned out of a silicon-on-insulator wafer by CMOS-compatible fabrication processes. The electronic properties of the nanowires are characterized by four-probe and low temperature Hall effect measurements. The I-V curves of the nanowires are linear at small voltage bias. The temperature dependence of the nanowire resistance allows the nanowire to be used as a highly sensitive thermometer. At high voltage bias, the I-V curves of the nanowire become nonlinear due to the effect of Joule heating. The temperature of the nanowire heater can be accurately monitored by the nanowire itself as a thermometer.

Water solar distiller productivity enhancement using concentrating solar water heater and phase change material (PCM

Directory of Open Access Journals (Sweden)

Miqdam T. Chaichan

2015-03-01

Full Text Available This paper investigates usage of thermal energy storage extracted from concentrating solar heater for water distillation. Paraffin wax selected as a suitable phase change material, and it was used for storing thermal energy in two different insulated treasurers. The paraffin wax is receiving hot water from concentrating solar dish. This solar energy stored in PCM as latent heat energy. Solar energy stored in a day time with a large quantity, and some heat retrieved for later use. Water’s temperature measured in a definite interval of time. Four cases were studied: using water as storage material with and without solar tracker. Also, PCM was as thermal storage material with and without solar tracker.The system working time was increased to about 5 h with sun tracker by concentrating dish and adding PCM to the system. The system concentrating efficiency, heating efficiency, and system productivity, has increased by about 64.07%, 112.87%, and 307.54%, respectively. The system working time increased to 3 h when PCM added without sun tracker. Also, the system concentrating efficiency increased by about 50.47%, and the system heating efficiency increased by about 41.63%. Moreover, the system productivity increased by about 180%.

Policy development for solar water heaters: the case of Lebanon

International Nuclear Information System (INIS)

Chedid, R.B.

2000-01-01

Full text.The electric energy demand in Lebanon is estimated to grow at an average of 3-5% per year for the coming 10 years. Such an increase in energy demand is problematic for Lebanon since its economy is almost totally dependent on imported fuel which contributes to 97% of the overall energy requirements. Solar water heaters (SWH) are regarded as the most important element in a long term energy conservation and management strategy for this country, but their promotion is a national issue requiring the participation of many stake holders and decision makers. Additionally, the success of solar energy penetration into the existing energy market is constrained by many factors such as technical and financial limitations, decision criteria and policy instruments. This paper will explore the feasibility of SWH, and will work out, using the Analytic Hierarchy Process technique, a policy to ensure a large scale diffusion of SWH in the energy market

Hydrodynamic aspects of the design of feed heaters and de-aerator storage tanks

International Nuclear Information System (INIS)

Kubie, J.; Rowe, M.; Jones, E.W.

1979-01-01

Regenerative feed heaters of the direct-contact type and feed water deaerators transmit large quantities of saturated, i.e. boiling, water. Drainage of saturated flows has long been a problem because of the possibility of the flow flashing to steam. Adequate drainage of direct-contact heaters is particularly important because of the danger of condensate returning to the turbine and causing serious damage. Likewise, a deaerator must drain easily or the boiler feed pump to which it drains will lose suction head and cavitate. This paper examines a number of hydrodynamic aspects of heater design and operating experience with particular emphasis on the problem of drainage. Formulae are derived and presented with recommendations for their use by designers in the power plant industry. (author)

Coupled solar still, solar heater

Energy Technology Data Exchange (ETDEWEB)

Davison, R R; Harris, W B; Moor, D H; Delyannis, A; Delyannis, E [eds.

1976-01-01

Computer simulation of combinations of solar stills and solar heaters indicates the probable economic advantage of such an arrangement in many locations if the size of the heater is optimized relative to that of the still. Experience with various low cost solar heaters is discussed.

Evaluation of Solar Air Heater Performance with Artificial Rib Roughness over the Absorber Plate using Finite Element Modelling Analysis

Science.gov (United States)

Kumar, K. Ravi; Nikhil Varma, P.; Jagadeesh, N.; Sandeep, J. V.; Cheepu, Muralimohan; Venkateswarlu, D.; Srinivas, B.

2018-03-01

Among the different renewable energy resources, solar energy is widely used due to its quantitative intensity factor. Solar air heater is cheap, simple in design and has got wide range of applications. A modest solar air heater has a lower in heat transfer and thermal performance as it has heat transfer coefficient lower in between coated absorber plate and the carrier fluid. This low thermal performance can be reduced to a greater extent by introducing the artificially created roughness over the absorber plate of the solar heater. In the present study, the combination of various geometries and roughness’s on the absorber plate are reported. Methods have been developed and implemented in order to improve the rate of the heat transfer. A comparison is drawn among different geometries to select the most effective absorber plate roughness. For flow analysis k-ω SST model was used and the constant heat flux was taken as 1100 W/m2. The Reynolds number is varied in a range from 3000 to 20000. The variation of different parameters temperature, Nusselt number, turbulence kinetic energy and heat transfer coefficient with Reynolds number were examined and discussed.

A theoretical model for flow boiling CHF from short concave heaters

International Nuclear Information System (INIS)

Galloway, J.E.; Mudawar, I.

1995-01-01

Experiments were performed to enable the development of a new theoretical mode for the enhancement in CHF commonly observed with flow boiling on concave heater as compared to straight heaters. High-speed video imaging and photomicrography were employed to capture the trigger mechanism for CHF each type heater. A wavy vapor layer was observed to engulf the heater surface in each case, permitting liquid access to the surface only in regions where depressions (troughs) in the liquid vapor interface made contact with the surface. CHF in each case occurred when the pressure force exerted upon the wavy vapor-liquid inter ace in the contact region could no longer overcome the momentum of the vapor produced in these regional. Shorter interfacial wavelengths with greater curvature were measured on the curve, heater than on the straight heater, promoting a greater pressure force on the wave interface and a corresponding increase in CHF for the curved heater. A theoretics. CHF model is developed from these observations, based upon a new theory for hydrodynamic instability, along a curved interface. CHF data are predicted with good accuracy for both heaters. 23 refs., 9 figs

The sun as hot water source. Answers to questions on the solar water heater; Le soleil source d'eau chaude. Les reponses a vos questions sur le chauffe-eau solaire

Energy Technology Data Exchange (ETDEWEB)

NONE

2004-07-01

This guide answers to the main questions concerning a water heating system for domestic use. It aims to help the people who want to buy a solar water heater, to better estimate the advantages and the limits, in providing information on the operating and the use. (A.L.B.)

Quasi-steady state thermal performance of a solar air heater

African Journals Online (AJOL)

2017-01-17

Jan 17, 2017 ... two kind of solar air heaters are commonly used relates ...... step is then initialized with output temperature of the first ..... Where da is the diameter of the aluminum wire making the porous absorber mesh (da 0.45mm) and Dh ...

High temperature collecting performance of a new all-glass evacuated tubular solar air heater with U-shaped tube heat exchanger

International Nuclear Information System (INIS)

Wang, Pin-Yang; Guan, Hong-Yang; Liu, Zhen-Hua; Wang, Guo-San; Zhao, Feng; Xiao, Hong-Sheng

2014-01-01

Highlights: • A novel solar air heater with simplified CPC and U-type heat exchanger is designed and tested. • The system is made up of 10 linked collecting panels. • Simplified CPC has a much lower cost at the expense of slight efficiency loss. • The air heater can propose the heated air exceeding 200 °C with great air flow rate. - Abstract: Experiment and simulation are conducted on a new-type all-glass evacuated tubular solar air heater with simplified compound parabolic concentrator (CPC). The system is made up of 10 linked collecting panels and each panel includes a simplified CPC and an all-glass evacuated tube with a U-shaped copper tube heat exchanger installed inside. Air is gradually heated when passing through each U-shaped copper tube. The heat transfer model of the solar air heater is established and the outlet air temperature, the heat power and heat efficiency are calculated. Calculated and experimental results show that the present experimental system can provide the heated air exceeding 200 °C. The whole system has an outstanding high-temperature collecting performance and the present heat transfer model can meet the general requirements of engineering calculations

Ultrathin Polyimide-Stainless Steel Heater for Vacuum System Bake-out

CERN Document Server

Rathjen, Christian; Henrist, Bernard; Kölemeijer, Wilhelmus; Libera, Bruno; Lutkiewicz, Przemyslaw

2005-01-01

Space constraints in several normal conducting magnets of the LHC required the development of a dedicated permanent heater for vacuum chamber bake-out. The new heater consists of stainless steel bands inside layers of polyimide. The overall heater thickness is about 0.3 mm. The low magnetic permeability is suitable for applications in magnetic fields. The material combination allows for temperatures high enough to activate a NEG coating. Fabrication is performed in consecutive steps of tape wrapping. Automation makes high volume production at low costs possible. About 800 m of warm vacuum system of the long straight sections of the LHC will be equipped with the new heater. This paper covers experience gained at CERN from studies up to industrialization.

Design and stability limits of the HPLWR re-heater

International Nuclear Information System (INIS)

Herbell, H.; Class, A.; Starflinger, J.; Schulenberg, T.

2010-01-01

The High Performance Light Water Reactor (HPLWR) is a particular design study of a supercritical water cooled reactor. A heat exchanger design has been proposed for the re-heater as a shell-and-tube heat exchanger. Inside the tubes fluid undergoes pseudo-condensing, e.g. it changes its density from steam-like to liquid-like properties (from 80 kg/m 3 to 582 kg/m 3 ) at supercritical pressure, whereas the shell side superheats intermediate pressure steam. For sub-critical pressures an instability has been reported by Goodykoontz and Dorsch (19679. The experiment exhibits unstable steam condensation in case of downward flow inside a tube of 7.4 mm diameter and 2.42 m length in some specific cases. The counter-current condenser was cooled with water flowing in an annulus surrounding the condenser tube. This experiment motivates the current investigation of instabilities for supercritical pseudo-condensation. The study includes static instabilities, i.e. Ledingegg instability and flow maldistribution of the parallel tubes, as well as pressure drop oscillations. At the present stage, no instabilities are predicted for the specific operation conditions of the HPLWR. The commercial system code APROS is used to perform one dimensional transient simulations of the described experiment to understand the physical mechanism. These simulations show that choking flow initiates the pressure oscillations. These periodically change steam temperatures, and consequently the condensation rate. In turn, this modifies the sound speed which is responsible for choking. Condensate reverse flow at choked conditions triggers the pressure waves. APROS simulations and experimental results agree well both in pressure amplitude and frequency. APROS simulations at supercritical pressure conditions did not exhibit any instability as the fluid velocity is clearly sub-sonic in the entire HPLWR re-heater. (authors)

Small scale heater tests in argillite of the Eleana Formation at the Nevada Test Site

International Nuclear Information System (INIS)

McVey, D.F.; Thomas, R.K.; Lappin, A.R.

1979-11-01

Near-surface heater tests were run in the Eleana Formation at the Nevada Test Site, in an effort to evaluate argillaceous rock for nuclear waste storage. The main test, which employed a full-scale heater with a thermal output approximating commercial borosilicate waste, was designed to operate for several months. Two smaller, scaled tests were run prior to the full-scale test. This report develops the thermal scaling laws, describes the pretest thermal and thermomechanical analysis conducted for these two tests, and discusses the material properties data used in the analyses. In the first test, scaled to a large heater of 3.5 kW power, computed heater temperatures were within 7% of measured values for the entire 96-hour test run. The second test, scaled to a large heater having 5.0 kW power, experienced periodic water in-flow onto the heater, which tended to damp the temperature. For the second test, the computed temperatures were within 7% of measured for the first 20 hours. After this time, the water effect became significant and the measured temperatures were 15 to 20% below those predicted. On the second test, rock surface spallation was noted in the bore hole above the heater, as predicted. The scaled tests indicated that in-situ argillite would not undergo major thermostructural failure during the follow-on, 3.5 kW, full-scale test. 24 figures, 6 tables

Performance investigation of a novel frost-free air-source heat pump water heater combined with energy storage and dehumidification

International Nuclear Information System (INIS)

Wang, Fenghao; Wang, Zhihua; Zheng, Yuxin; Lin, Zhang; Hao, Pengfei; Huan, Chao; Wang, Tian

2015-01-01

Highlights: • Experiments are carried out to investigate a novel frost-free ASHPWH system. • Dynamic characteristics of the system are studied at different ambient conditions. • Test results confirm the expected potential to control the frost-free process. • The COP increased 17.9% and 3.4% respectively in comparison with RCD at −3 °C and 3 °C. - Abstract: Air-source heat pump (ASHP) often operates with substantial frost formation on the outdoor heat exchanger at low ambient temperature in winter, it insulates the finned surface and also reduces heat transfer rate, leading to performance degradation or even shutdown of ASHP systems. Although several defrosting methods have been reported, the frosting and defrosting processes reduced energy efficiency and resulted in, in some cases, heat pump breakdown. To solve this problem, a novel frost-free air-source heat pump water heater (ASHPWH) system has been developed, which coupled with an extra heat exchanger coated by a solid desiccant (EHECSD) with an energy storage device (ESD). Based on the previous studies, a further analysis and comprehensive research on the novel frost-free ASHPWH system is presented in this paper. The dynamic characteristics of the novel system are investigated experimentally in different ambient conditions. An experimental setup and experimental procedures are described in detail. Thereafter, the dehumidification efficiency and regeneration efficiency of EHECSD, suction and discharge pressures of the compressor, the temperature of PCM are evaluated during the heating and regeneration modes respectively. Results indicate that the system can keep the evaporator frost-free for 32, 34, 36 min during heating mode at the ambient temperatures of −3 °C, 0 °C and 3 °C and 85% RH. Compared with the reverse-cycle defrosting (RCD), COP of the frost-free ASHPWH are 17.9% and 3.4% higher at the ambient temperature of −3 °C and 3 °C respectively. With this innovative technology, it has

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.

Gravity and Heater Size Effects on Pool Boiling Heat Transfer

Science.gov (United States)

Kim, Jungho; Raj, Rishi

2014-01-01

The current work is based on observations of boiling heat transfer over a continuous range of gravity levels between 0g to 1.8g and varying heater sizes with a fluorinert as the test liquid (FC-72/n-perfluorohexane). Variable gravity pool boiling heat transfer measurements over a wide range of gravity levels were made during parabolic flight campaigns as well as onboard the International Space Station. For large heaters and-or higher gravity conditions, buoyancy dominated boiling and heat transfer results were heater size independent. The power law coefficient for gravity in the heat transfer equation was found to be a function of wall temperature under these conditions. Under low gravity conditions and-or for smaller heaters, surface tension forces dominated and heat transfer results were heater size dependent. A pool boiling regime map differentiating buoyancy and surface tension dominated regimes was developed along with a unified framework that allowed for scaling of pool boiling over a wide range of gravity levels and heater sizes. The scaling laws developed in this study are expected to allow performance quantification of phase change based technologies under variable gravity environments eventually leading to their implementation in space based applications.

Experimental validation of dynamic simulation of the flat plate collector in a closed thermosyphon solar water heater

International Nuclear Information System (INIS)

Taherian, H.; Rezania, A.; Sadeghi, S.; Ganji, D.D.

2011-01-01

This work studies the dynamic simulation of thermosyphon solar water heater collector considering the weather conditions of a city in north of Iran. The simulation was done for clear and partly cloudy days. The useful energy, the efficiency diagrams, the inlet and the outlet of collector, center of the absorber and center of the glass cover temperatures, were obtained. The simulation results were then compared with the experimental results in fall and showed a good agreement.

A modernized high-pressure heater protection system for nuclear and thermal power stations

Science.gov (United States)

Svyatkin, F. A.; Trifonov, N. N.; Ukhanova, M. G.; Tren'kin, V. B.; Koltunov, V. A.; Borovkov, A. I.; Klyavin, O. I.

2013-09-01

Experience gained from operation of high-pressure heaters and their protection systems serving to exclude ingress of water into the turbine is analyzed. A formula for determining the time for which the high-pressure heater shell steam space is filled when a rupture of tubes in it occurs is analyzed, and conclusions regarding the high-pressure heater design most advisable from this point of view are drawn. A typical structure of protection from increase of water level in the shell of high-pressure heaters used in domestically produced turbines for thermal and nuclear power stations is described, and examples illustrating this structure are given. Shortcomings of components used in the existing protection systems that may lead to an accident at the power station are considered. A modernized protection system intended to exclude the above-mentioned shortcomings was developed at the NPO Central Boiler-Turbine Institute and ZioMAR Engineering Company, and the design solutions used in this system are described. A mathematical model of the protection system's main elements (the admission and check valves) has been developed with participation of specialists from the St. Petersburg Polytechnic University, and a numerical investigation of these elements is carried out. The design version of surge tanks developed by specialists of the Central Boiler-Turbine Institute for excluding false operation of the high-pressure heater protection system is proposed.

Co-Production Performance Evaluation of a Novel Solar Combi System for Simultaneous Pure Water and Hot Water Supply in Urban Households of UAE

Directory of Open Access Journals (Sweden)

Nutakki Tirumala Uday Kumar

2017-04-01

Full Text Available Water is the most desirable and sparse resource in Gulf cooperation council (GCC region. Utilization of point-of-use (POU water treatment devices has been gaining huge market recently due to increase in knowledge of urban population on health related issues over contaminants in decentralized water distribution networks. However, there is no foolproof way of knowing whether the treated water is free of contaminants harmful for drinking and hence reliance on certified bottled water has increased worldwide. The bottling process right from treatment to delivery is highly unsustainable due to huge energy demand along the supply chain. As a step towards sustainability, we investigated various ways of coupling of membrane distillation (MD process with solar domestic heaters for co-production of domestic heat and pure water. Performance dynamics of various integration techniques have been evaluated and appropriate configuration has been identified for real scale application. A solar combi MD (SCMD system is experimentally tested for single household application for production 20 L/day of pure water and 250 L/day of hot water simultaneously without any auxiliary heating device. The efficiency of co-production system is compared with individual operation of solar heaters and solar membrane distillation.

Infrared Heaters

Science.gov (United States)

1979-01-01

The heating units shown in the accompanying photos are Panelbloc infrared heaters, energy savers which burn little fuel in relation to their effective heat output. Produced by Bettcher Manufacturing Corporation, Cleveland, Ohio, Panelblocs are applicable to industrial or other facilities which have ceilings more than 12 feet high, such as those pictured: at left the Bare Hills Tennis Club, Baltimore, Maryland and at right, CVA Lincoln- Mercury, Gaithersburg, Maryland. The heaters are mounted high above the floor and they radiate infrared energy downward. Panelblocs do not waste energy by warming the surrounding air. Instead, they beam invisible heat rays directly to objects which absorb the radiation- people, floors, machinery and other plant equipment. All these objects in turn re-radiate the energy to the air. A key element in the Panelbloc design is a coating applied to the aluminized steel outer surface of the heater. This coating must be corrosion resistant at high temperatures and it must have high "emissivity"-the ability of a surface to emit radiant energy. The Bettcher company formerly used a porcelain coating, but it caused a production problem. Bettcher did not have the capability to apply the material in its own plant, so the heaters had to be shipped out of state for porcelainizing, which entailed extra cost. Bettcher sought a coating which could meet the specifications yet be applied in its own facilities. The company asked The Knowledge Availability Systems Center, Pittsburgh, Pennsylvania, a NASA Industrial Applications Center (IAC), for a search of NASA's files

Low cost solar array project silicon materials task. Development of a process for high capacity arc heater production of silicon for solar arrays

Science.gov (United States)

Fey, M. G.

1981-01-01

The experimental verification system for the production of silicon via the arc heater-sodium reduction of SiCl4 was designed, fabricated, installed, and operated. Each of the attendant subsystems was checked out and operated to insure performance requirements. These subsystems included: the arc heaters/reactor, cooling water system, gas system, power system, Control & Instrumentation system, Na injection system, SiCl4 injection system, effluent disposal system and gas burnoff system. Prior to introducing the reactants (Na and SiCl4) to the arc heater/reactor, a series of gas only-power tests was conducted to establish the operating parameters of the three arc heaters of the system. Following the successful completion of the gas only-power tests and the readiness tests of the sodium and SiCl4 injection systems, a shakedown test of the complete experimental verification system was conducted.

Artificial neural networks for the performance prediction of heat pump hot water heaters

Science.gov (United States)

Mathioulakis, E.; Panaras, G.; Belessiotis, V.

2018-02-01

The rapid progression in the use of heat pumps, due to the decrease in the equipment cost, together with the favourable economics of the consumed electrical energy, has been combined with the wide dissemination of air-to-water heat pumps (AWHPs) in the residential sector. The entrance of the respective systems in the commercial sector has made important the modelling of the processes. In this work, the suitability of artificial neural networks (ANN) in the modelling of AWHPs is investigated. The ambient air temperature in the evaporator inlet and the water temperature in the condenser inlet have been selected as the input variables; energy performance indices and quantities characterising the operation of the system have been selected as output variables. The results verify that the, easy-to-implement, trained ANN can represent an effective tool for the prediction of the AWHP performance in various operation conditions and the parametrical investigation of their behaviour.

Parallel heater system for subsurface formations

Science.gov (United States)

Harris, Christopher Kelvin [Houston, TX; Karanikas, John Michael [Houston, TX; Nguyen, Scott Vinh [Houston, TX

2011-10-25

A heating system for a subsurface formation is disclosed. The system includes a plurality of substantially horizontally oriented or inclined heater sections located in a hydrocarbon containing layer in the formation. At least a portion of two of the heater sections are substantially parallel to each other. The ends of at least two of the heater sections in the layer are electrically coupled to a substantially horizontal, or inclined, electrical conductor oriented substantially perpendicular to the ends of the at least two heater sections.

Output control system in a boiling water atomic power plant

International Nuclear Information System (INIS)

Sadakane, Ken-ichiro.

1975-01-01

Object: To provide a line in bypass relation with a water heater, a flow rate of said bypass being adjusted to thereby perform quick responsive sub-cool control of a core inlet. Structure: A steam line and a water line are disposed so as to feed water from the reactor core to the water heater via turbine and thence to the core. A line disposed in bypass relation with the water heater arranged in the water line includes a control valve for controlling water passing through the bypass line and a main control for sending a signal to said control valve, said main control receiving loads from the outside, whereby a control signal is transmitted to the control valve, causing water passing through the water heater and water line to the core to be bypassed, a period of time for supplying time to be reduced, and quick response to be enhanced. (Kamimura, M.)

Classification of Feedwater Heater Performance Degradation Using Residual Sign Matrix

International Nuclear Information System (INIS)

Ha, Gayeon; Heo, Gyunyoung; Song, Seok Yoon

2016-01-01

Since a performance of Feedwater Heater (FWH) is directly related to the thermodynamic efficiency of Nuclear Power Plants (NPPs), performance degradation of FWH results in loss of thermal power and ultimately business benefit. Nevertheless, it is difficult to diagnose its degradation of performance during normal operation due to its minor changes in process parameters, for instance, pressure, temperature, and flowrate. In this paper, six degradation modes have been analyzed and the performance indices for FWH such as Terminal Temperature Difference (TTD) and Drain Cooling Approach (DCA) have been used to diagnose degradation modes. PEPSE (Performance Evaluation of Power System Efficiencies) simulation, which is a plant simulation software simulating plant static characteristic and building energy balance model, has been used to generate the data of performance indices of FWH and actual measurements of FWH from NPPs was used to validate the classification model. In this paper, six degradation modes have been analyzed and the performance indices for FWH have been used to diagnose what degradation mode occurs. The RSM was proposed as a trend identifier of variables. Using RSM, it is possible to obtain appropriate information of the variables in noise environment since noise can be compressed while the original information is being converted to a trend. The SVC has been performed to classify the degradation mode of FWH, and then actual measurements of FWH from NPPs was used to validate the classification model. Performance indices under various leakage conditions show different patterns. In further study, tube leakage simulations for the various cases will be needed

Classification of Feedwater Heater Performance Degradation Using Residual Sign Matrix

Energy Technology Data Exchange (ETDEWEB)

Ha, Gayeon; Heo, Gyunyoung [Kyung Hee University, Seoul (Korea, Republic of); Song, Seok Yoon [KHNP CRI, Daejeon (Korea, Republic of)

2016-10-15

Since a performance of Feedwater Heater (FWH) is directly related to the thermodynamic efficiency of Nuclear Power Plants (NPPs), performance degradation of FWH results in loss of thermal power and ultimately business benefit. Nevertheless, it is difficult to diagnose its degradation of performance during normal operation due to its minor changes in process parameters, for instance, pressure, temperature, and flowrate. In this paper, six degradation modes have been analyzed and the performance indices for FWH such as Terminal Temperature Difference (TTD) and Drain Cooling Approach (DCA) have been used to diagnose degradation modes. PEPSE (Performance Evaluation of Power System Efficiencies) simulation, which is a plant simulation software simulating plant static characteristic and building energy balance model, has been used to generate the data of performance indices of FWH and actual measurements of FWH from NPPs was used to validate the classification model. In this paper, six degradation modes have been analyzed and the performance indices for FWH have been used to diagnose what degradation mode occurs. The RSM was proposed as a trend identifier of variables. Using RSM, it is possible to obtain appropriate information of the variables in noise environment since noise can be compressed while the original information is being converted to a trend. The SVC has been performed to classify the degradation mode of FWH, and then actual measurements of FWH from NPPs was used to validate the classification model. Performance indices under various leakage conditions show different patterns. In further study, tube leakage simulations for the various cases will be needed.

Technical support document: Energy efficiency standards for consumer products: Room air conditioners, water heaters, direct heating equipment, mobile home furnaces, kitchen ranges and ovens, pool heaters, fluorescent lamp ballasts and television sets. Volume 1, Methodology

Energy Technology Data Exchange (ETDEWEB)

1993-11-01

The Energy Policy and Conservation Act (P.L. 94-163), as amended, establishes energy conservation standards for 12 of the 13 types of consumer products specifically covered by the Act. The legislation requires the Department of Energy (DOE) to consider new or amended standards for these and other types of products at specified times. DOE is currently considering amending standards for seven types of products: water heaters, direct heating equipment, mobile home furnaces, pool heaters, room air conditioners, kitchen ranges and ovens (including microwave ovens), and fluorescent light ballasts and is considering establishing standards for television sets. This Technical Support Document presents the methodology, data, and results from the analysis of the energy and economic impacts of the proposed standards. This volume presents a general description of the analytic approach, including the structure of the major models.

Design data brochure: Solar hot air heater

Science.gov (United States)

1978-01-01

The design, installation, performance, and application of a solar hot air heater for residential, commercial and industrial use is reported. The system has been installed at the Concho Indian School in El Reno, Oklahoma.

The thermal performance of the two-pass, two-glass-cover solar air heater

Energy Technology Data Exchange (ETDEWEB)

Persad, P.; Sateunanathan, S.

1983-08-01

Analytic models are developed for the performance prediction of a two-glass-cover solar air heater operated in both the single-pass and two-pass modes. It is shown that the two-pass mode of operation is superior to the single-pass mode of operation over the range of collector inlet temperatures considered. This is seen to be mainly due to the fact that, in the two-pass mode of operation, the outer glass cover is cooled by the working fluid, thereby reducing the top losses. It is also shown that the performance in the two-pass mode of operation is independent of length, over the range of collector lengths considered, and that a critical plate spacing, dependent on the temperature level of operation of the collector, is indicated. Predicted values of performance are in good agreement with experimental results.

Discussion on Boiler Efficiency Correction Method with Low Temperature Economizer-Air Heater System

Science.gov (United States)

Ke, Liu; Xing-sen, Yang; Fan-jun, Hou; Zhi-hong, Hu

2017-05-01

This paper pointed out that it is wrong to take the outlet flue gas temperature of low temperature economizer as exhaust gas temperature in boiler efficiency calculation based on GB10184-1988. What’s more, this paper proposed a new correction method, which decomposed low temperature economizer-air heater system into two hypothetical parts of air preheater and pre condensed water heater and take the outlet equivalent gas temperature of air preheater as exhaust gas temperature in boiler efficiency calculation. This method makes the boiler efficiency calculation more concise, with no air heater correction. It has a positive reference value to deal with this kind of problem correctly.

Remote Visual Testing (RVT) for the diagnostic inspection of feedwater heaters

International Nuclear Information System (INIS)

Nugent, M.J.; Pellegrino, B.A.

1993-01-01

Feedwater heaters are an important component in the overall plant heat rate, reliability, availability, performance and maintenance considerations at power stations. The ability to diagnose heater problems in-situ properly can lead to: (1) Preventative plugging of damaged, but unfailed tubes; (2) In-place repair procedures; (3) Incorporation of corrective actions into replacement designs or heater/unit operations. The benefits and limitations of Non-Destructive Testing (NDT) on feedwater heaters are briefly reviewed. All Remote Visual Testing (RVT) including borescopes, fiberscopes, videoborescopes and Closed Circuit Television (CCTV) cameras are discussed along with currently accepted formats for documentation. The benefits of a comprehensive in-place inspection involving Remote Visual Testing are discussed in relationship to its diagnostic capabilities. The results of eight post-service heater inspections are discussed along with the root cause of failure of seven unique failure mechanisms. These inspections, including FWH access, RVT tool and data analysis, are detailed. 13 figs

Experimental Study of a Novel Direct-Expansion Variable Frequency Finned Solar/Air-Assisted Heat Pump Water Heater

Directory of Open Access Journals (Sweden)

Jing Qin

2018-01-01

Full Text Available A novel direct expansion variable frequency finned solar/air-assisted heat pump water heater was fabricated and tested in the enthalpy difference lab with a solar simulator. A solar/air source evaporator-collector with an automatic lifting glass cover plate was installed on the system. The system could be operated in three modes, namely, air, solar, and dual modes. The effects of the ambient temperature, solar irradiation, compressor frequency, and operating mode on the performance of this system were studied in this paper. The experimental results show that the ambient temperature, solar irradiation, and operating mode almost have no effect on the energy consumption of the compressor. When the ambient temperature and the solar irradiation were increased, the COP was found to increase with decreasing heating time. Also, when the compressor frequency was increased, an increase in the energy consumption of the compressor and the heat gain of the evaporator were noted with a decrease in the heating time.

Build Your Own Solar Air Heater.

Science.gov (United States)

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

The solar air heater is a simple device for catching some of the sun's energy to heat a home. Procedures for making and installing such a heater are presented. Included is a materials list, including tools needed for constructing the heater, sources for obtaining further details, and a list of material specifications. (JN)

A masonry heater, a large thermal flywheel and constant temperatures : the winter of 1996/1997 of the Alberta Sustainable Home/Office

Energy Technology Data Exchange (ETDEWEB)

Ostrowski, J.; Fofonoff, B.

1997-07-01

A masonry heater using scrapwood and firewood as the only source of back-up heat in this 1820 sq ft single-family live-in demonstration home/office, was described. The heater also contributed significantly to the thermal flywheel of the house. Together with other forms of thermal mass within the building (concrete slab, wood studs, drywall, tiles, furniture, plants, etc), the masonry heater was sufficient to see the occupants through the severe and long winter of 1996/97 with comfortable indoor temperatures. The masonry heater is located near the center of the house with a sunny view towards the south. On sunny winter days it operates as a passive solar heat sink, with the sun charging up the brick face by about five degrees C. In the evening, a 40 pound load of scrap and firewood will take about 1.25 hours to penetrate through the refractory interior core and brick exterior. This provides a cosy fireplace for the occupants, while storing heat in its mass for slow release during the next 1.5 to 3 days. It heats water for storage in the hot water tank. During the period of September 1996 to May 1997 one cord of wood was burned, which is about 12 per cent of the energy pumped into the average single family home in Calgary during the same period. Experience to-date suggests that the masonry heater performs very well as a back-up heater, maintaining an ambient temperature of about 20 degrees C throughout the winter. Some flat plate solar collectors might be necessary to provide for radiant floor heating of the mass since floor temperatures were lower than most occupants found comfortable.

Conasauga near-surface heater experiment. Final report

International Nuclear Information System (INIS)

Krumhansl, J.L.

1979-11-01

The Conasauga Experiment was undertaken to begin assessment of the thermomechanical and chemical response of a specific shale to the heat resulting from emplacement of high-level nuclear wastes. Canister-size heaters were implanted in Conasauga shale in Tennessee. Instrumentation arrays wee placed at various depths in drill holes around each heater. The heaters operated for 8 months and, after the first 4 days, were maintained at 385 0 C. Emphasis was on characterizing the thermal and mechanical response of the formation. Conduction was the major mode of heat transport; convection was perceptible only at temperatures above the boiling point of water. Despite dehydration of the shale at higher temperatures, in situ thermal conductivity was essentially constant and not a function of temperature. The mechanical response of the formation was a slight overall expansion, apparently resulting in a general decrease in permeability. Metallurgical observations were made, the stability of a borosilicate glass wasteform simulant was assessed, and changes in formation mineralogy and groundwater composition were documented. In each of these areas, transient nonequilibrium processes occur that affect material stability and may be important in determining the integrity of a repository. In general, data from the test reflect favorably on the use of shale as a disposal medium for nuclear waste

The design of electrical heater pins to simulate transient dryout and post-dryout of water reactor fuel

International Nuclear Information System (INIS)

Burgess, M.H.; Butcher, A.A.; Sidoli, J.E.A.

1978-11-01

A theoretical assessment of indirect and direct filled heater simulations of nuclear reactor fuel pins is described. For reasons of fast temperature response, a direct unfilled heater, with thermocouples buried in the walls, is recommended for studies of Loss-of-Coolant Accidents leading to dryout, post-dryout and rewetting. A design of heater pins, for use in SGHWR or PWR experiments, and compatible with existing 9MW power supplies, is described. Experiments to confirm collapse pressure calculations at 1000 0 C and thermocouple response times are also reported. (author)

China's transition to green energy systems: The economics of home solar water heaters and their popularization in Dezhou city

International Nuclear Information System (INIS)

Li Wei; Song Guojun; Beresford, Melanie; Ma, Ben

2011-01-01

Studying the popularization of solar water heaters (SWHs) is significant for understanding China's transition to green energy systems. Using Dezhou as a case study, this paper presents new angles on analyzing SWH deployment in China by addressing both the economic potential and the institutional dimensions at the local level. Using estimates from the demand-side of hot water for a typical three-person household in Dezhou, the paper evaluates the economic potential of a SWH in saving electricity and reducing carbon dioxide emissions. Then, expanding the analysis beyond economics, we take an institutionalist approach to study the institutional factors that contribute to Dezhou's success in SWH adoptions. By examining the five main actors in Dezhou's energy regime, we find that Dezhou's SWH deployment is driven by an urge to develop businesses and the local economy, and its success results from at least five unique factors, including the development of SWH industrial clusters in Dezhou, big manufacturers' market leadership in SWH innovations, a tight private enterprise-local government relation, geographic location within the SWH industrial belt, and the adaptive attitude of Dezhou's households towards natural resource scarcity. - Highlights: → We study the popularization of solar water heaters in Dezhou, China. → We study the institutional factors that contribute to Dezhou's success. → Five main actors in Dezhou's energy regime are examined. → Dezhou's success results from at least five unique factors. → This leads to important directions for improving China'ss green innovation adoption.

Experimental investigation of the performance of an elbow-bend type heat exchanger with a water tube bank used as a heater or cooler in alpha-type Stirling machines

Energy Technology Data Exchange (ETDEWEB)

El-Ehwany, A.A.; Hennes, G.M. [Mech. Power Dept., Faculty of Eng., Ain Shams University, Cairo (Egypt); Eid, E.I. [Mech. Dept., Faculty of Ind. Education, Suez Canal University, Suez 43515 (Egypt); El-Kenany, E. [The Specialized Studies Academy, Workers University, Tech. Dept., Mansura (Egypt)

2011-02-15

In this work the effect of the elbow-bend geometry and the effect of the tube arrangement on the performance of air-to-water heat exchanger is studied experimentally. In elbow-bend heat exchanger, the direction of the working fluid is bended at 90 degrees to its inlet direction. The heating or cooling fluid flows inside straight tubes while the working fluid flows past the tubes along an elbow pass. Three different types of the geometry of the elbow with three different tube bank arrangements were studied. The results were plotted and analyzed to clarify the effects of the elbow-bend geometry, the tube bank arrangements and the dead volume in the heat exchanger on the heat transfer and pressure drop. Two empirical correlations were deduced for each design, one to predict the relation between Nusselt and Reynolds numbers, while the other relation is between the friction factor and Reynolds number. This work was done to select the more suitable design to be used as a heater or a cooler in Stirling machines. (author)

Nuclear plant power up-rate study: feedwater heater evaluations

International Nuclear Information System (INIS)

Svensson, Eric; Catapano, Michael; Coakley, Michael; Thomas, Dan

2014-01-01

Given today's nuclear industry business climate, it has become common for Utility companies to consider increasing unit capacities through turbine replacement and power up-rates. An integral part of the studies conducted by many towards this end, involve the generation of a set of turbine cycle heat balances with predicted performance parameters for the up-rated condition. Once these tentative operating values are established, it becomes necessary to evaluate the suitability of the existing components within each system to ensure they are capable of continued safe and reliable operation. The ultimate cost for the up-rate, including the cost for any major required modifications or significant replacements is weighed against increased revenue generated from the up-rate over time. Exelon's Peach Bottom Atomic Power Station (PBAPS) is currently planning for an Extended Power up-rate (EPU) for both units. To ensure the existing Feedwater Heaters (FWH) could maintain the operating and transient response margins at the EPU condition, an engineering study was conducted. Powerfect Inc. in conjunction with SPX Heat Transfer LLC were contracted to provide engineering services to analyze the design, thermal performance, reliability and operating conditions at projected EPU conditions. Specifically, to address the following with regard to the station's Feedwater Heaters (FWHs): 1. Evaluate Drain Cooler (DC) Velocities - including zone inlet velocity, cross and window velocities and outlet velocities. 2. Evaluate Drain Cooler Zone Pressure Drop for effect on drain cooler margins to flashing. 3. Evaluate differential pressure allowable across the pass partition plate. 4. Evaluate Drain Cooler Tube Vibration Potential. 5. Perform detailed steam dome velocity calculations. The goal of the study was to identify the most susceptible areas within the heaters for problems and potential failures when operating at the higher duty of the EPU condition for the remaining life

Heater test planning for the near surface test facility at the Hanford reservation

International Nuclear Information System (INIS)

DuBois, A.; Binnall, E.; Chan, T.; McEvoy, M.; Nelson, P.; Remer, J.

1979-03-01

The underground test facility NSTF being constructed at Gable Mountain, is the site for a group of experiments designed to evaluate the thermo-mechanical suitability of a deep basalt stratum as a permanent repository for nuclear waste. Thermo-mechanical modeling was performed to help design the instrumentation arrays for the three proposed heater tests (two full scale tests and one time scale test) and predict the thermal environment of the heaters and instruments. The modeling does not reflect recent RHO revisions to the in situ heater experiment plan. Heaters, instrumentation, and data acquisition system designs and recommendations were adapted from those used in Sweden

Heat Pump Water Heater Ducting Strategies with Encapsulated Attics in Climate Zones 2 and 4

Energy Technology Data Exchange (ETDEWEB)

Sweet, M. L. [Southface Energy Inst., Upper Marlboro, MD (United States); Francisco, A.; Roberts, S. G.

2016-05-01

The focus of this study is on the performance of HPWHs with several different duct configurations and their effects on whole building heating, cooling, and moisture loads. A.O. Smith 60 gallon Voltex (PHPT-60) heat pump water heaters (HPWHs) were included at two project sites and ducted to or located within spray foamed encapsulated attics. The effect of ducting a HPWH's air stream does not diminish its efficiency if the ducting does not reduce intake air temperature, which expands HPWH application to confined areas. Exhaust ducts should be insulated to avoid condensation on the exterior, however this imposes a risk of condensation occurring in the duct's interior near the HPWH due to large variation of temperatures between the compressor and the duct and the presence of bulk moisture around the condenser. The HPWH's air conditioning impact on HVAC equipment loads is minimal when the intake and exhaust air streams are connected to a sealed attic and not the living space. A HPWH is not suitable as a replacement dehumidifier in sealed attics as peak moisture loads were observed to only be reduced if the heat pump operated during the morning. It appears that the intake air temperature and humidity was the most dominant variable affecting HPWH performance. Different ducting strategies such as exhaust duct only, intake duct only, and exhaust and intake ducting did not have any effect on HPWH performance.

Test of the heatpump system Fre-Heater model D, made by Mueller Europa BV. Installation for the cooling of milk and the heating of water on farms. Beproeving van een warmtepompsysteem, type Fre-Heater model D, fabrikaat Mueller. Installatie voor het koelen van melk en het verwarmen van water op de boerderij

Energy Technology Data Exchange (ETDEWEB)

Verheij, C P; de Vries, J; van Haren, J J

1982-01-01

At the request of Mueller Europa BV (the Netherlands) the Fre-Heater D heat-pump system was tested for its suitability for the simultaneous cooling of milk and the heating of water on farms. The main purpose of the test was to provide information about the technical properties of the system and about the possibilities it offers for the saving of energy. The test was carried out according to the directives laid down in the 'Beproevingsmethode voor warmtepompsystemen ten behoeve van het verwarmen van water op de boerderij' (Test method for heat-pump systems for the heating of water on farms), issued by the Netherlands Institute for Dairy Research, 1980. The results obtained in the tests were used for the calculation of the savings of energy. The system was compared with a conventional air-cooled refrigerated farm milk tank with a COPR (coefficient of performance of refrigeration) of 2.5. The Fre-Heater D was found to have a COPR of 2.40. The net savings of energy that could be achieved varied from 20.9 to 13.8 kWh per m3 cooled 'milk' at farm sizes from 40 to 78 cows. Based on a price of electrical energy of Dfl 0.20 per kWh, this installation was found to be economically justified at a farm with 40 cows and more (milk production 5.5 m3 per cow per year). For a farm with 40 cows the pay-back period was found to be 4.1 years, and for a farm with 78 cows this period was 3.2 years.

Heater for Combustible-Gas Tanks

Science.gov (United States)

Ingle, Walter B.

1987-01-01

Proposed heater for pressurizing hydrogen, oxygen, or another combustible liquid or gas sealed in immersion cup in pressurized tank. Firmly supported in finned cup, coiled rod transfers heat through liquid metal to gas tank. Heater assembly welded or bolted to tank flange.

Evaluation of RSG-GAS purification system and pool warm water layer supplier performance

International Nuclear Information System (INIS)

Sudiyono; Suhadi; Diah-Erlina-Lestari

2005-01-01

Function of RSG-GAS purification system and warm water supplier (KBE 02) are to pick up dissolve activation result and another dirts of warm water layer. To keep quality of water at the decided level. The system is equipped by heater to supply warm water layer on the reactor pool surface the distribution is to reduce radiation level in the operation hall area a speciality on the reactor pool surface. Line KBE 02 tomord beam tube headitty system supplies water necessary to be shielding to beam tube in use off time. Of the RSG-GAS purification system and pool warm water layer performance date can be shown north of water is always in good condition. To require the dechded requirement. Resin live time is two years and then months

Quench Heater Experiments on the LHC Main Superconducting Magnets

OpenAIRE

Rodríguez-Mateos, F; Pugnat, P; Sanfilippo, S; Schmidt, R; Siemko, A; Sonnemann, F

2000-01-01

In case of a quench in one of the main dipoles and quadrupoles of CERN's Large Hadron Collider (LHC), the magnet has to be protected against excessive temperatures and high voltages. In order to uniformly distribute the stored magnetic energy in the coils, heater strips installed in the magnet are fired after quench detection. Tests of different quench heater configurations were performed on various 1 m long model and 15 m long prototype dipole magnets, as well as on a 3 m long prototype quad...

49 CFR 179.12 - Interior heater systems.

Science.gov (United States)

2010-10-01

... Design Requirements § 179.12 Interior heater systems. (a) Interior heater systems shall be of approved design and materials. If a tank is divided into compartments, a separate system shall be provided for... 49 Transportation 2 2010-10-01 2010-10-01 false Interior heater systems. 179.12 Section 179.12...

Low-temperature baseboard heaters with integrated air supply - An analytical and numerical investigation

Energy Technology Data Exchange (ETDEWEB)

Ploskic, Adnan; Holmberg, Sture [Fluid and Climate Technology, School of Architecture and Built Environment, KTH, Marinens vaeg 30, SE-13640 Handen, Stockholm (Sweden)

2011-01-15

The functioning of a hydronic baseboard heating system with integrated air supply was analyzed. The aim was to investigate thermal performance of the system when cold outdoor (ventilation) airflow was forced through the baseboard heater. The performance of the system was evaluated for different ventilation rates at typical outdoor temperatures during the Swedish winter season. Three different analytical models and Computational Fluid Dynamics (CFD) were used to predict the temperature rise of the airflow inside the baseboard heater. Good agreement between numerical (CFD) and analytical calculations was obtained. Calculations showed that it was fully possible to pre-heat the incoming airflow to the indoor temperature and to cover transmission losses, using 45 C supply water flow. The analytical calculations also showed that the airflow per supply opening in the baseboard heater needed to be limited to 7.0 l/s due to pressure losses inside the channel. At this ventilation rate, the integrated system with one air supply gave about 2.1 more heat output than a conventional baseboard heating system. CFD simulations also showed that the integrated system was capable of countering downdraught created by 2.0 m high glazed areas and a cold outdoor environment. Draught discomfort in the case with the conventional system was slightly above the recommended upper limit, but heat distribution across whole analyzed office space was uniform for both heating systems. It was concluded that low-temperature baseboard heating systems with integrated air supply can meet both international comfort requirements, and lead to energy savings in cold climates. (author)

Electrical heaters for thermo-mechanical tests at the Stripa mine

International Nuclear Information System (INIS)

Burleigh, R.H.; Binnall, E.P.; DuBois, A.O.; Norgren, D.U.; Ortiz, A.R.

1979-01-01

Electrical heaters were installed at the Stripa mine in Sweden to simulate the heat flux expected from canisters containing nuclear waste. Three heater types were designed and fabricated: two full scale heaters, 2.6 m in length and 324 mm in diameter, supplying a maximum power output of 5 kW; eight peripheral heaters of 25 mm diameter, supplying 1.1 kW; and eight time scale heaters, one-third the size and power of the full scale heaters. The heater power can be monitored by panel meters as well as by a computer-based data acquisition system. Both the controller and the heater were designed with a high degree of redundancy in case of component failure. Auxiliary items were provided with the heaters to monitor borehole decrepitation and heater temperature, and to dewater the heater holes. This report describes the above systems and relates experience gained during testing, installation, and operation

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.

Novel Method for Measuring the Heat Collection Rate and Heat Loss Coefficient of Water-in-Glass Evacuated Tube Solar Water Heaters Based on Artificial Neural Networks and Support Vector Machine

Directory of Open Access Journals (Sweden)

Zhijian Liu

2015-08-01

Full Text Available The determinations 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, the direct determination requires complex detection devices and a series of standard experiments, which also wastes too much time and manpower. To address this problem, we propose machine learning models including artificial neural networks (ANNs and support vector machines (SVM to predict the heat collection rate and heat loss coefficient without a direct determination. Parameters that can be easily obtained by “portable test instruments” were set as independent variables, including tube length, number of tubes, tube center distance, heat water mass in tank, collector area, final temperature and angle between tubes and ground, while the heat collection rate and heat loss coefficient determined by the detection device were set as dependent variables respectively. Nine hundred fifteen samples from in-service water-in-glass evacuated tube solar water heaters were used for training and testing the models. Results show that the multilayer feed-forward neural network (MLFN with 3 nodes is the best model for the prediction of heat collection rate and the general regression neural network (GRNN is the best model for the prediction of heat loss coefficient due to their low root mean square (RMS errors, short training times, and high prediction accuracies (under the tolerances of 30%, 20%, and 10%, respectively.

Is your electric process heater safe?

Energy Technology Data Exchange (ETDEWEB)

Tiras, C.S.

2000-04-01

Over the past 35 years, electric process heaters (EPHs) have been used to heat flowing fluids in different sectors of the energy industry: oil and gas exploration and production, refineries, petrochemical plants, pipeline compression facilities and power-generation plants. EPHs offer several advantages over fired heaters and shell-and-tube exchangers, which have been around for many years, including: smaller size, lighter weight, cleaner operation, lower capital costs, lower maintenance costs, no emissions or leakage, better control and improved safety. However, while many industrial standards have addressed safety concerns of fired heaters and shell-and-tube exchangers (API, TEMA, NFPA, OSHA and NEC), no standards address EPHs. The paper presents a list of questions that plant operators need to ask about the safety of their electric process heaters. The answers are also given.

Buffer mass test - Heater design and operation

International Nuclear Information System (INIS)

Nilsson, J.; Ramqvist, G.; Pusch, R.

1984-06-01

The nuclear waste is assumed to be contained in cylindrical metal canisters which will be inserted in deposition holes. Heat is generated as a result of the continuing decay of the radioactive waste and in the Buffer Mass Test (BMT) the heat flux expected from such canisters was simulated by the use of six electric heaters. the heaters were constructed partly of aluminium and partly of stainless steel. They are 1520 mm in length and 380 mm in diameter, and give a maximum power output of 3000 W. The heater power can be monitored by panel meters coupled to a computer-based data acquisition system. Both the heater and the control system were manufactured with a high degree of redundancy in case of component failure. This report describes the design, construction, testing, installation and necessary tools for heater installation and dismantling operation. (author)

SINGLE HEATER TEST FINAL REPORT

International Nuclear Information System (INIS)

J.B. Cho

1999-01-01

The Single Heater Test is the first of the in-situ thermal tests conducted by the U.S. Department of Energy as part of its program of characterizing Yucca Mountain in Nevada as the potential site for a proposed deep geologic repository for the disposal of spent nuclear fuel and high-level nuclear waste. The Site Characterization Plan (DOE 1988) contained an extensive plan of in-situ thermal tests aimed at understanding specific aspects of the response of the local rock-mass around the potential repository to the heat from the radioactive decay of the emplaced waste. With the refocusing of the Site Characterization Plan by the ''Civilian Radioactive Waste Management Program Plan'' (DOE 1994), a consolidated thermal testing program emerged by 1995 as documented in the reports ''In-Situ Thermal Testing Program Strategy'' (DOE 1995) and ''Updated In-Situ Thermal Testing Program Strategy'' (CRWMS M and O 1997a). The concept of the Single Heater Test took shape in the summer of 1995 and detailed planning and design of the test started with the beginning fiscal year 1996. The overall objective of the Single Heater Test was to gain an understanding of the coupled thermal, mechanical, hydrological, and chemical processes that are anticipated to occur in the local rock-mass in the potential repository as a result of heat from radioactive decay of the emplaced waste. This included making a priori predictions of the test results using existing models and subsequently refining or modifying the models, on the basis of comparative and interpretive analyses of the measurements and predictions. A second, no less important, objective was to try out, in a full-scale field setting, the various instruments and equipment to be employed in the future on a much larger, more complex, thermal test of longer duration, such as the Drift Scale Test. This ''shake down'' or trial aspect of the Single Heater Test applied not just to the hardware, but also to the teamwork and cooperation between

Heater test in the Opalinus Clay of the Mont Terri URL. Gas release and water redistribution - Contribution to heater experiment (HE); Rock and bentonite thermo-hydro-mechanical (THM) processes in the nearfield

International Nuclear Information System (INIS)

Jockwer, N.; Wieczorek, K.

2006-06-01

Beside salt and granite, clay formations are investigated as potential host rocks for disposing radioactive waste. In Switzerland in the canton Jura close to the city of St. Ursanne, an underground laboratory was built in the vicinity of the reconnaissance gallery of a motorway tunnel. Since 1995, a consortium of 12 international organisations is running this laboratory for investigating the suitability of the Opalinus clay formation with regard to disposal of radioactive waste. In 1999, the Heater Experiment B (HE-B) was started for investigating the coupled thermo-hydro-mechanical (THM) processes of the Opalinus clay in interaction with the bentonite buffer. The principal contractors of this project were the Bundesanstalt fuer Geowissenschaften und Rohstoffe (BGR), the Empresa Nacional de Residuos Radiactivos S. A. (ENRESA), the Gesellschaft fuer Anlagen- und Reaktorsicherheit (GRS) mbH, and the National Cooperative for the Disposal of Radioactive Waste (NAGRA). GRS participated in that experiment for determining the subjects of gas generation, gas release, water content, and water redistribution in the Opalinus clay during heating. This was achieved by analysing gas and water samples from the test field before, during, and after the heating period and by performing geoelectric tomography measurements in the heated region. The in-situ measurements were supported by an additional laboratory programme. This report deals with the work of GRS performed in this project during the years 1999 to 2005. All the results obtained in the frame of the project are presented. Additional laboratory measurements conducted by the Pore Water Laboratory at CIEMAT in Madrid are also presented. The participation of GRS was funded by German Ministry of Economics and Labour (BMWA) under the contract No. 02 E 9602 and by the Commission of the European Communities under the contract No. FIKW.CT-2001-00132. (orig.)

Efficiency of the pre-heater against flow rate on primary the beta test loop

International Nuclear Information System (INIS)

Edy Sumarno; Kiswanta; Bambang Heru; Ainur R; Joko P

2013-01-01

Calculation of efficiency of the pre-heater has been carried out against the flow rate on primary the BETA Test Loop. BETA test loop (UUB) is a facilities of experiments to study the thermal hydraulic phenomenon, especially for thermal hydraulic post-LOCA (Lost of Coolant Accident). Sequences removal on the BETA Test Loop contained a pre-heater that serves as a getter heat from the primary side to the secondary side, determination of efficiency is to compare the incoming heat energy with the energy taken out by a secondary fluid. Characterization is intended to determine the performance of a pre-heater, then used as tool for analysis, and as a reference design experiments. Calculation of efficiency methods performed by operating the pre-heater with fluid flow rate variation on the primary side. Calculation of efficiency on the results obtained that the efficiency change with every change of flow rate, the flow rate is 71.26% on 163.50 ml/s and 60.65% on 850.90 ml/s. Efficiency value can be even greater if the pre-heater tank is wrapped with thermal insulation so there is no heat leakage. (author)

solar dryer with biomass backup heater for drying fruits

African Journals Online (AJOL)

SOLAR DRYER WITH BIOMASS BACKUP HEATER FOR DRYING FRUITS: DEVELOPMENT AND PERFORMANCE ANALYSIS. ... Journal of Science and Technology (Ghana) ... Most solar dryers rely on only solar energy as the heat source.

Solar Water Heater

Science.gov (United States)

1993-01-01

As a Jet Propulsion Laboratory (JPL) scientist Dr. Eldon Haines studied the solar energy source and solar water heating. He concluded he could build a superior solar water heating system using the geyser pumping principle. He resigned from JPL to develop his system and later form Sage Advance Corporation to market the technology. Haines' Copper Cricket residential system has no moving parts, is immune to freeze damage, needs no roof-mounted tanks, and features low maintenance. It provides 50-90 percent of average hot water requirements. A larger system, the Copper Dragon, has been developed for commercial installations.

First phase of small diameter heater experiments in tuff

International Nuclear Information System (INIS)

Zimmerman, R.M.

1983-01-01

As part of the Nevada Nuclear Waste Storage Investigations (NNWSI) project, we have undertaken small diameter heater experiments in the G-Tunnel Underground Facility on the Nevada Test Site (NTS). These experiments are to evaluate the thermal and hydrothermal behavior which might be encountered if heat producing nuclear waste were disposed of in welded and nonwelded tuffs. The two Phase I experiments discussed have focused on vertical borehole emplacements. In each experiment, temperatures were measured along the surface of the 10.2-cm-dia heater and the 12.7-cm-dia boreholes. For each experiment, measurements were compared with computer model representations. Maximum temperatures reached were: 196 0 C for the welded tuff after 21 days of operations at 800W and 173 0 C for the nonwelded tuff after 35 days of operations at 500W. Computed results indicate that the same heat transfer model (includes conduction and radiation only) can describe the behavior of both tuffs using empirical techniques to describe pore water vaporization. Hydrothermal measurements revealed heat-indiced water migration. Results indicated that small amounts of liquid water migrated into the welded tuff borehole early in the heating period. Once the rock-wall temperatures exceeded 94 0 C, in both tuffs, there was mass transport of water vapor as evidence indicated condensation cooler regions. Borehole pressures remained essentially ambient during the thermal periods

Forced-circulation solar water heater using a solar battery; Taiyo denchi wo mochiita kyosei junkahshiki taiyonetsu onsuiki

Energy Technology Data Exchange (ETDEWEB)

Asai, S; Mizuno, T [Yazaki Corp., Tokyo (Japan)

1997-11-25

Optimal operation control was discussed on a forced-circulation solar water heater using solar cells not only as the power supply of a heat collecting pump, but also for controlling operation of the heat collecting pump. With this system, when the amount of power generated by solar cells reaches a sufficient level for operating the heat collecting pump, the heat collecting pump starts operation, wherein the heat collecting medium circulates in the system. The discussion was given by using simulation based on experimental expressions such as the relation expression between insolation and heat collecting medium flow rate as derived from the result of the system`s heat collecting performance test. As a result, the following conclusions were obtained: optimal insolation for activating the discussed system is from 50 to 100 W/m {sup 2}, and the heat collected within this range is within -1.5% of the collected heat amount at an optimum value; optimal activating insolation for the case of 1000 to 2000 W/m {sup 2} with low daily cumulative insolation is from 0 to 50 W/m {sup 2}, whereas the optimal activating insolation amount increases as the daily cumulative insolation amount increases; and the optimal activating insolation amount increases as water to be supplied requires higher temperature. 1 ref., 17 figs., 2 tabs.

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.

Analisis Termal High Pressure Feedwater Heater di PLTU PT. XYZ

Directory of Open Access Journals (Sweden)

Maria Ulfa Damayanti

2017-01-01

Full Text Available Abstrak- PT. XYZ mengoperasikan tiga unit Pembangkit Listrik Tenaga Uap (PLTU unit 3, 7 dan 8 berkapasitas 2.030 MegaWatt. Pada PLTU Paiton unit 7 dan 8 terdapat delapan buah feedwater heater yaitu empat buah Low Pressure Water Heater (LPWH, tiga buah High Pressure Water Heater (HPWH, dan sebuah dearator. Pada PLTU Paiton unit 7 dan 8 terdapat kerusakan pada HPWH 6 yang menyebabkan penurunan efisiensi dari siklus secara keseluruhan. Penurunan efisiensi dapat terjadi karena temperatur feedwater sebelum masuk ke boiler terlalu rendah, sehingga kalor yang dibutuhkan oleh boiler untuk memanaskan feedwater meningkat. Oleh karena itu konsumsi batubara akan meningkat dan menyebabkan terjadi kenaikan biaya operasional harian dalam sistem pembangkit. Dari data Divisi Produksi PT. XYZ Unit 7 dan 8 diperoleh spesifikasi HPWH 6, 7, dan 8 dan propertis fluida dalam HPWH 6, 7, dan 8. Data tersebut digunakan sebagai dasar analisis termal yang meliputi performa masing-masing HPH. Tahap selanjutnya dalam analisis termal adalah memvariasikan beban 25%, 50%, 75%, 100%, dan 105%. Tahap terakhir analisis adalah menghitung performa dengan variasi sumbatan (plug 5%, 10%, 15%, dan 20% sesuai dengan variasi beban. Hasil yang didapatkan dari penelitian tugas akhir ini adalah nilai effectiveness tertinggi tercapai pada pembebanan 100% serta menghasilkan pressure drop tertinggi pada pembebanan 105%, nilai effectiveness terbesar serta nilai pressure drop terkecil terjadi pada zona Condensing, serta sumbatan (plugging pada HPH akan menyebabkan penurunan nilai effectiveness dan kenaikan pressure drop sisi tube.

Numerical investigation on effect of riser diameter and inclination on system parameters in a two-phase closed loop thermosyphon solar water heater

International Nuclear Information System (INIS)

Aung, Nay Zar; Li, Songjing

2013-01-01

Highlights: • Optimum inclination for maximum heat flux changes with latitude of location. • Optimum inclination for maximum heat flux also changes local solar time. • Maximum flow rate increases with increasing of riser tube size. • Maximum mass flow rate is obtained at different inclinations for different risers. • Length of two-phase region depends on inclination angles but not riser tube size. - Abstract: In this work, the effect of riser diameter and its inclination angle on system parameters in a two-phase closed loop thermosyphon solar water heater has been numerically investigated. Here, receivable heat flux by the collector, circulating mass flow rate, driving pressure, total pressure drop, heat transfer coefficient in risers and collector efficiency are defined as system parameters. For this aim, a model of two-phase thermosyphon solar water heater that is acceptable for various inclinations is presented and variations of riser diameter and inclination are considered. The riser tube size is varied from 1.25 cm to 2.5 cm with inclination range 2–75°. The system absolute pressure is set as 3567 Pa and water is chosen as working fluid. The results show that higher inclination angle is required for higher latitude location to obtain maximum solar heat flux. At local solar noon of 21.996 north latitude, the optimum inclination angle increases in the range of 24–44° with increasing of riser diameter giving maximum circulating mass flow rate from 0.02288 kg/s to 0.03876 kg/s. The longer two-phase heat transfer characteristics can be obtained at smaller inclination angles and mass flow rate for all riser tube sizes. Therefore, it is observed that the optimum inclination angles and diameters for solar heat flux, circulating mass flow rate and heat transfer coefficient in two-phase thermosyphon systemdo not coincide. From this work, better understanding and useful information are provided for constructing two-phase thermosyphon solar heaters

Loss of feedwater heater analysis for the South Texas Project

International Nuclear Information System (INIS)

Joyce, K.C.; Johnson, M.R.; Albury, C.R.

1987-01-01

The results of the steady state and transient analyses of the low pressure feedwater heater train for the South Texas Nuclear Project are presented. The South Texas Project consists of two 1250 MW Westinghouse PWR units. This analysis was performed using the Modular Modeling System (MMS) simulation code. The model presented will be incorporated into the secondary side model in support of the plant training simulator and the analysis of secondary side transients. Results of this analysis are considered preliminary until benchmarked against actual plant data. A model description of the feedwater heater train from the condensate pumps to the deaerator is presented. The methodology used to develop the model is also discussed. Results of the steady state run are presented, and a transient, the loss of extraction steam to feedwater heater 15A, is examined

Particulate matter sensor with a heater

Science.gov (United States)

Hall, Matthew [Austin, TX

2011-08-16

An apparatus to detect particulate matter. The apparatus includes a sensor electrode, a shroud, and a heater. The electrode measures a chemical composition within an exhaust stream. The shroud surrounds at least a portion of the sensor electrode, exclusive of a distal end of the sensor electrode exposed to the exhaust stream. The shroud defines an air gap between the sensor electrode and the shroud and an opening toward the distal end of the sensor electrode. The heater is mounted relative to the sensor electrode. The heater burns off particulate matter in the air gap between the sensor electrode and the shroud.

A prototype construction of bearing heater system

International Nuclear Information System (INIS)

Firman Silitonga

2007-01-01

A bearing heater system has been successfully constructed using transformer-like method of 1000 VA power, 220 V primary voltage, and 50 Hz electrical frequency. The bearing heater consists of primary coil 230 turns, U type and bar-type iron core with 36 cm 2 , 9 cm 2 ,and 3 cm 2 cross-section, and electrical isolation. The bearing heater is used to enlarge the diameter of the bearing so that it can be easily fixed on an electric motor shaft during replacement because the heating is conducted by treated the bearing as a secondary coil of a transformer. This bearing heater can be used for bearing with 3 and 6 cm of inner diameter and 12 cm of maximum outside diameter. (author)

Electrical resistivity monitoring of the single heater test in Yucca Mountain

International Nuclear Information System (INIS)

Ramirez, A.

1997-10-01

Of the several thermal, mechanical and hydrological measurements being used to monitor the rockmass response in the Single Heater Test, electrical resistance tomography (ERT) is being used to monitor the movement of liquid water with a special interest in the movement of condensate out of the system. Images of resistivity change were calculated using data collected before, during and after the heating episode. This report will concentrate on the results obtained after heating ceased; previous reports discuss the results obtained during the heating phase. The changes recovered show a region of increasing resistivity approximately centered around the heater as the rock mass cooled. The size of this region grows with time and the resistivity increases become stronger. The increases in resistivity are caused by both temperature and saturation changes. The Waxman Smits model has been used to calculate rock saturation after accounting for temperature effects. The saturation estimates suggest that during the heating phase, a region of drying forms around the heater. During the cooling phase, the dry region has remained relatively stable. Wetter rock regions which developed below the heater during the heating phase, are slowly becoming smaller in size during the cooling phase. The last set of images indicate that some rewetting of the dry zone may be occurring. The accuracy of the saturation estimates depends on several factors that are only partly understood

Electrical resistivity monitoring of the thermomechanical heater test in Yucca Mountain

International Nuclear Information System (INIS)

Ramirez, A.; Daily, W.; Buettner, M.

1997-01-01

A test is being conducted in the densely welded Topopah Springs tuff within Yucca Mountain, Nevada to study the thermomechanical and hydrological behavior of this horizon when it is headed. A single 4 kW heater, placed in a horizontal borehole, was turned on August, 1996 and will continue to heat the rockmass until April 1997. Of the several thermal, mechanical and hydrological measurements being used to monitor the rockmass response, electrical resistance tomography (ERT) is being used to monitor the movement of liquid water with a special interest in the movement of condensate out of the system. Four boreholes, containing a total of 30 ERT electrodes, were drilled to form the sides of a 30 foot square with the heater at the center and perpendicular to the plane. Images of resistivity change were calculated using data collected before and during the heating episode. The changes recovered show a region of decreasing resistivity approximately centered around the heater. The size this region grows with time and the resistivity decreases become stronger. The changes in resistivity are caused by both temperature and saturation changes. The observed resistivity changes suggest that the rock adjacent to the heater dries as heating progresses. This dry region is surrounded by a region of increased saturation where steam recondenses and imbibes into the rock

Electrical resistivity monitoring of the thermomechanical heater test in Yucca Mountain

International Nuclear Information System (INIS)

Ramirez, A.; Daily, W.; Buettner, M.; LaBrecque, L

1996-01-01

A test is being conducted in the densely welded Topopah Springs tuff within Yucca Mountain, Nevada to study the thermomechanical and hydrological behavior of this horizon when it is heated. A single 4 kW heater, placed in a horizontal borehole, was turned on August, 1996 and will continue to heat the rockmass until April 1997. Of the several thermal, mechanical and hydrological measurements being used to monitor the rockmass response, electrical resistance tomography (ERT) is being used to monitor the movement of liquid water with a special interest in the movement of condensate out of the system. Four boreholes, containing a total of 30 ERT electrodes, were drilled to form the sides of a 30 foot square with the heater at the center and perpendicular to the plane. Images of resistivity change were calculated using data collected before and during the heating episode. The changes recovered show a region of decreasing resistivity approximately centered around the heater. The size this region grows with time and -the resistivity decreases become stronger. The changes in resistivity are caused by both temperature and saturation changes. The observed resistivity changes suggest that the rock adjacent to the heater dries as heating progresses. This dry region is surrounded by a region of increased saturation where steam recondenses and imbibes into the rock

An experimental evaluation of multi-pass solar air heaters

Energy Technology Data Exchange (ETDEWEB)

Satcunanathan, S.; Persad, P.

1980-12-01

Three collectors of identical dimensions but operating in the single-pass, two-pass and three-pass modes were tested simultaneously under ambient conditions. It was found that the two-pass air heater was consistently better than the single-pass air heater over the day for the range of mass flow rates considered. It was also found that at a mass flow rate of 0.0095 kg s/sup -1/ m/sup -2/, the thermal performances of the two-pass and three-pass collectors were identical, but at higher flow rates the two-pass collector was superior to the three-pass collector, the superiority decreasing with increasing mass flow rate.

Heating Performance Study on a Passive Solar Heater

Directory of Open Access Journals (Sweden)

Naz Muhammad Y.

2017-01-01

Full Text Available A passive thermosyphon heating system was designed, fabricated and tested for its thermal performance in semi-arid and four-season climate of Pakistan. The heating system design was based on a two-stage storage and natural thermosyphon circulation of the water. The objective of the study was to enhance the heating performance of the thermosyphon systems by using a semicircular steel pot collector, water carrying copper coil cover, two step water storage, and side mirror reflectors. The experiments were conducted during April to July 2014 when ambient temperature was reported to vary between 32°C and 44°C. In continuous flow mode operation, the hot water temperature remained between 46°C and 78°C. Since water temperature in the range of 45°C to 50°C is considered suitable for the domestic use, the presented design can easily reach the temperatures even higher than those acceptable for the domestic use.

SINGLE HEATER TEST FINAL REPORT

Energy Technology Data Exchange (ETDEWEB)

J.B. Cho

1999-05-01

The Single Heater Test is the first of the in-situ thermal tests conducted by the U.S. Department of Energy as part of its program of characterizing Yucca Mountain in Nevada as the potential site for a proposed deep geologic repository for the disposal of spent nuclear fuel and high-level nuclear waste. The Site Characterization Plan (DOE 1988) contained an extensive plan of in-situ thermal tests aimed at understanding specific aspects of the response of the local rock-mass around the potential repository to the heat from the radioactive decay of the emplaced waste. With the refocusing of the Site Characterization Plan by the ''Civilian Radioactive Waste Management Program Plan'' (DOE 1994), a consolidated thermal testing program emerged by 1995 as documented in the reports ''In-Situ Thermal Testing Program Strategy'' (DOE 1995) and ''Updated In-Situ Thermal Testing Program Strategy'' (CRWMS M&O 1997a). The concept of the Single Heater Test took shape in the summer of 1995 and detailed planning and design of the test started with the beginning fiscal year 1996. The overall objective of the Single Heater Test was to gain an understanding of the coupled thermal, mechanical, hydrological, and chemical processes that are anticipated to occur in the local rock-mass in the potential repository as a result of heat from radioactive decay of the emplaced waste. This included making a priori predictions of the test results using existing models and subsequently refining or modifying the models, on the basis of comparative and interpretive analyses of the measurements and predictions. A second, no less important, objective was to try out, in a full-scale field setting, the various instruments and equipment to be employed in the future on a much larger, more complex, thermal test of longer duration, such as the Drift Scale Test. This ''shake down'' or trial aspect of the Single Heater Test applied

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.

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.

Solar-energy-system performance evaluation: Scattergood School Recreation Center, West Branch, Iowa, June 1978-April 1979

Energy Technology Data Exchange (ETDEWEB)

Shenfish, K.L.

1979-01-01

The solar energy system at Scattergood School in Iowa is designed to supply space heating and hot water and is also used to dry grain. The system has an array of flat plate solar air heaters connected to a pebble bed and two 120-gallon tanks. Back-up heat is furnished by two gas heaters for space heating and a 52-gallon electric water heater. The system is briefly described, and its thermal performance is analyzed using a system energy balance technique. (LEW)

Architecture for Absorption Based Heaters

Science.gov (United States)

Moghaddam, Saeed; Chugh, Devesh

2018-04-24

An absorption based heater is constructed on a fluid barrier heat exchanging plate such that it requires little space in a structure. The absorption based heater has a desorber, heat exchanger, and absorber sequentially placed on the fluid barrier heat exchanging plate. The vapor exchange faces of the desorber and the absorber are covered by a vapor permeable membrane that is permeable to a refrigerant vapor but impermeable to an absorbent. A process fluid flows on the side of the fluid barrier heat exchanging plate opposite the vapor exchange face through the absorber and subsequently through the heat exchanger. The absorption based heater can include a second plate with a condenser situated parallel to the fluid barrier heat exchanging plate and opposing the desorber for condensation of the refrigerant for additional heating of the process fluid.

Hydrothermal field test with french candidate clay embedding steel heater in the Stripa mine

International Nuclear Information System (INIS)

Pusch, R.; Karnland, O.; Lajudie, A.; Lechelle, J.; Bouchet, A.

1992-12-01

Field experiments with French kaolinite/smectite clay heated up to 170 degrees C in boreholes in granite were conducted for 8 months and 4 years. The clay heated for 8 months has a considerably higher water content and it had undergone much less changes in mineralogy and physical properties than the clay exposed to heating for 4 years. The drying of the latter clay was probably caused by hydrogen gas from corrosion of the heater. The clay next to the heater turned into clay-stone despite conversion of the kaolinite component to smectite. (42 refs)

Microbial induced corrosion (MIC) on DHP copper by Desulfovibrio desulfuricans and Bacillus megaterium strains in media simulating heater waters

International Nuclear Information System (INIS)

Zumelzu, E.; Cabezas, C.; Schoebitz, R.; Ugarte, R.; Rodriguez, E.D.; Rios, J.

2003-01-01

The complexity and diversity of microbial populations in water heating systems of steam generators make it necessary to study the magnitude of the metabolic activity of bacteria and biofilm development that may lead to degradation of metal components through microbial induced corrosion (MIC). Electrolytes simulating the conditions found in heater water networks were used to induce biofilm formation on DHP copper coupons by Desulfovibrio desulfuricans DSMZ and Bacillus megaterium C10, a commercial strain and an isolate from these waters, respectively. In order to enhance their action, industrial waters enriched with the minimum nutrient content such as sodium lactate and sodium sulphite for the DSMZ strain and glucose, proteose peptone and starch for the C10 strain were employed. Biofilm formation was studied under controlled temperature, time, shaking, pH and concentrations of the media used in this study. Then, the samples were electrochemically tested in an artificial solution of sea water as control medium, based on the hypothesis that the action of an aggressive biofilm/electrolyte medium generates damaged and non-damaged areas on the metal surface, and assuming that the sea water trial can detect the latter. Hence, a higher anodic current was associated with a lower degradation of the metal surface by the action of one of the media under study. All these trials were performed along with bacterial count, scanning electron microscopy (SEM) and atomic absorption spectroscopy (AAS). Furthermore, it was possible to identify under which conditions MIC on DHP copper occurred and complex mechanisms from retention of cations to diffusion processes at the biofilm/tested media interface level were proposed. Surface corrosion by MIC took place on DHP copper; therefore, greater control on the treatment of industrial waters is highly desirable. (author)

Energy discharge heater power supply

International Nuclear Information System (INIS)

Jaskierny, W.

1992-11-01

The heater power supply is intended to supply capacitively stored,energy to embedded heater strips in cryo magnets. The amount of energy can be controlled by setting different charge different capacitor values. Two chassis' can be operated in series or interlocks are provided. The charge voltage, number of capacitors pulse can be monitored. There and dual channel has two discharge supplies in one chassis. This report reviews the characteristics of this power supply further

Effects of Delta-Shaped Obstacles on the Thermal Performance of Solar Air Heater

Directory of Open Access Journals (Sweden)

Adisu Bekele

2011-01-01

Full Text Available An experimental investigation has been carried out to study the effect of delta-shaped obstacles mounted on the absorber surface of an air heater duct with an aspect ratio 6 : 1 resembling the conditions close to solar air heaters. This study encompassed the Reynolds number (Re ranging from 3400 to 27600, longitudinal pitch of the obstacle (Pl/e varied from 3/2 to 11/2, and relative obstacle height (e/H varied from 0.25 to 0.75. The relative obstacle transverse pitch (Pt/b=7/3 and the angle of attack of flow on obstacle = 90° are kept constant during the whole experimentation. By comparing the heat transfer data obtained from the obstacle-mounted duct with that of smooth duct under similar geometrical and flow conditions, the obstacle-mounted duct enhances the heat transfer by 3.6-times at Re = 7276.82, Pl/e=3/2, and e/H=0.75.

China's transition to green energy systems: The economics of home solar water heaters and their popularization in Dezhou city

Energy Technology Data Exchange (ETDEWEB)

Li Wei, E-mail: weiweileede@gmail.com [Department of Economics, Macquarie University, Sydney, NSW 2109 (Australia); Song Guojun [Environmental Policy and Planning Institute (EPPI), Renmin University of China, Beijing (China); Beresford, Melanie [Department of Economics, Macquarie University, Sydney, NSW 2109 (Australia); Ma, Ben [Environmental Policy and Planning Institute (EPPI), Renmin University of China, Beijing (China)

2011-10-15

Studying the popularization of solar water heaters (SWHs) is significant for understanding China's transition to green energy systems. Using Dezhou as a case study, this paper presents new angles on analyzing SWH deployment in China by addressing both the economic potential and the institutional dimensions at the local level. Using estimates from the demand-side of hot water for a typical three-person household in Dezhou, the paper evaluates the economic potential of a SWH in saving electricity and reducing carbon dioxide emissions. Then, expanding the analysis beyond economics, we take an institutionalist approach to study the institutional factors that contribute to Dezhou's success in SWH adoptions. By examining the five main actors in Dezhou's energy regime, we find that Dezhou's SWH deployment is driven by an urge to develop businesses and the local economy, and its success results from at least five unique factors, including the development of SWH industrial clusters in Dezhou, big manufacturers' market leadership in SWH innovations, a tight private enterprise-local government relation, geographic location within the SWH industrial belt, and the adaptive attitude of Dezhou's households towards natural resource scarcity. - Highlights: > We study the popularization of solar water heaters in Dezhou, China. > We study the institutional factors that contribute to Dezhou's success. > Five main actors in Dezhou's energy regime are examined. > Dezhou's success results from at least five unique factors. > This leads to important directions for improving China'ss green innovation adoption.

Optimal design and placement of serpentine heat exchangers for indirect heat withdrawal, inside flat plate integrated collector storage solar water heaters (ICSSWH)

Energy Technology Data Exchange (ETDEWEB)

Gertzos, K.P.; Caouris, Y.G.; Panidis, T. [Dept. of Mechanical Engineering and Aeronautics, University of Patras, 265 00 Patras (Greece)

2010-08-15

Parameters that affect the temperature at which service hot water (SHW) is offered by an immersed tube heat exchanger (HX), inside a flat plate Integrated Collector Storage Solar Water Heater (ICSSWH), are examined numerically, by means of Computational Fluid Dynamics (CFD) analysis. The storage water is not refreshed and serves for heat accumulation. Service hot water is drawn off indirectly, through an immersed serpentine heat exchanger. For the intensification of the heat transfer process, the storage water is agitated by recirculation through a pump, which goes on only when service water flows inside the heat exchanger. Three main factors, which influence the performance, are optimized: The position of the HX relative to tank walls, the HX length and the tube diameter. All three factors are explored so that to maximize the service water outlet temperature. The settling time of the optimum configuration is also computed. Various 3-D CFD models were developed using the FLUENT package. The heat transfer rate between the two circuits of the optimum configuration is maintained at high levels, leading to service water outlet temperatures by 1-7 C lower than tank water temperatures, for the examined SHW flow rates. The settling time is retained at sufficient law values, such as 20 s. The optimal position was found to lay the HX in contact with the front and back walls of the tank, with an optimum inner tube diameter of 16 mm, while an acceptable HX length was found to be about 21.5 m. (author)

STUDY ON THE OPTIMIZATION OF IGBT THERMAL MANAGEMENT FOR PTC HEATER

Directory of Open Access Journals (Sweden)

J. W. JEONG

2015-12-01

Full Text Available It is essential to optimize HVAC (Heating, Ventilation and Air-Conditioning system for a thermal plant or an electric vehicle since it has a significant effect on the thermal efficiency. PTC (positive temperature coefficient heaters are often used for a heating system and the power module of the PTC heaters, IGBT (insulated gate bipolar mode transistor, requires thermal management. In this study, in order to maximize the cooling performance for IGBT, a novel method that uses forced convection inside the HVAC duct with heat sinks was developed. In addition, heat sinks were optimized in terms of IGBT junction temperature and heat sink weight by 3-dimensional CFD (Computational Fluid Dynamics simulation. The results show that the junction temperature of IGBT for 5.6kW PTC heater can be maintained at about 335K.

Solair heater program: solair applications study. Final report

Energy Technology Data Exchange (ETDEWEB)

1977-12-01

General Electric has designed and tested a low-cost solar system using a vacuum tube solar air heater under ERDA Contract E(11-1)-2705. This contract extension has been provided to evaluate various applications of this solar collector. The evaluation identified attractive applications, evaluated corresponding control procedures, estimated system performance, compared economically insolation and insulation, and evaluated the repackaging of off-the-shelf equipment for improved cost effectiveness. The results of this study prompted General Electric's marketing group to do a detailed commercialization study of a residential domestic water heating system using the Solair concept which has been selected as the most attractive application. Other attractive applications are space/domestic water heating and a heat pump assisted solar system/domestic water heating where the heat pump and the solar system function in parallel. A prime advantage of heated air solar systems over liquid systems is cost and longer life which results in higher BTU's/dollar. Other air system advantages are no liquid leakage problems, no toxicity of freezing problems, and less complicated equipment. A hybrid solar system has been identified that can improve the market penetration of solar energy. This system would use the existing mass of the house for energy storage thereby reducing solar cost and complexity. Adequate performance can be obtained with house temperature swings comparable to those used in nighttime setback of the thermostat. Details of this system are provided.

Solar water-heating performance evaluation-San Diego, California

Science.gov (United States)

1981-01-01

Report describes energy saved by replacing domestic, conventional natural gas heater with solar-energy subsystem in single-family residence near San Diego, California. Energy savings for 6 month test period averaged 1.089 million Btu. Collector array covered 65 square feet and supplied hot water to both 66-gallon solar storage tank and 40-gallon tank for domestic use. Natural gas supplied house's auxiliary energy.

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.

Effect of Graphene-EC on Ag NW-Based Transparent Film Heaters: Optimizing the Stability and Heat Dispersion of Films.

Science.gov (United States)

Cao, Minghui; Wang, Minqiang; Li, Le; Qiu, Hengwei; Yang, Zhi

2018-01-10

To optimize the performance of silver nanowire (Ag NW) film heaters and explore the effect of graphene on a film, we introduced poly(3,4-ethylenedioxythiophene):poly(4-styrenesulfonate) (PEDOT:PSS) and graphene modified with ethyl cellulose (graphene-EC) into the film. The high-quality and well-dispersed graphene-EC was synthesized from graphene obtained by electrochemical exfoliation as a precursor. The transparent film heaters were fabricated via spin-coating. With the assistance of graphene-EC, the stability of film heaters was greatly improved, and the conductivity was optimized by adjusting the Ag NW concentration. The film heaters exhibited a fast and accurate response to voltage, accompanied by excellent environmental endurance, and there was no significant performance degradation after being operated for a long period of time. These results indicate that graphene-EC plays a crucial role in optimizing film stability and heat dispersion in the film. The Ag NW/PEDOT:PSS-doped graphene-EC film heaters show a great potential in low-cost indium-tin-oxide-free flexible transparent electrodes, heating systems, and transparent film heaters.

Process and device for replacing heater in PWR pressurizer

International Nuclear Information System (INIS)

Gente, D.; Giron, M.

1990-01-01

To assure the tight fixation of replacing heater on a pressurizer penetration sleeve, a gas metal-arc welding single pass is executed. A tubular shaft is fixed over end of heater projecting from penetration sleeve. Over shaft is fixed tubular support for the torch which can rotate about axis of support axis heater. Welding torch and welding wire feeder roll are rotated in synchronisation by appropriate motors. Weld is made in single pass round periphery of heater and penetration sleeve [fr

On a Green Municipal Initiative in Cape Town (South Africa): Lessons from the Solar Water Heater Advanced Program

International Nuclear Information System (INIS)

Dubresson, Alain

2013-01-01

During the 2000's, the metropolitan municipality of Cape Town elaborated an ambitious energy transition strategy, backed up by the Energy and Climate Action Plan approved in 2010. One element of this plan is a mass solar water heater roll-out programme for households. Analysing the difficulties in the implementation of this programme, this article argues that the main limits to metropolitan action do not result primarily from local and/or multi-level governance issues but from national constraints and stakes which are deeply rooted in the political economy of South Africa. Any attempt to build an autonomous metropolitan energy policy is therefore today illusory in South Africa

Interim status report on the revision of ASME PTC 12.1 -- closed feedwater heaters

International Nuclear Information System (INIS)

Stellern, J.L.; Hoobler, J.V.; Milton, J.W.; Welch, T.; Kona, C.; Thompson, H.N.; Tsou, J.L.

1993-01-01

The ASME Performance Test Code (PTC) 12.1-1978 for the performance testing of feedwater heaters is being revised extensively and updated. The committee anticipates that the final draft of the proposed Code will be ready for industry review in 1993. This Code revision will greatly enhance the usefulness and cost effectiveness of feedwater heater performance testing. This paper has been prepared to report on the progress of the committee and to disseminate information on the nature of the revision. Included in this paper are some of the notable changes intended for the Code. The most extensive change is the calculation method, which is described in step-by-step detail. An approach is also described for using ultrasonic flow techniques to test individual or split-string feedwater heaters, when flow nozzles are not available. Additionally some educational information on the use and limitations of ultrasonic measurement instrumentation is included. Discussion is also included on the required uncertainty analysis. 3 refs., 2 figs., 2 tabs

Development of the robot for pressurizer electric heater inspection and repairing

International Nuclear Information System (INIS)

Jung, Seung Ho; Kim, Seung Ho; Su, Yong Chil

1999-01-01

In this study a robot system has been developed for inspection and maintenance of the pressurizer and the rod heaters. The developed robot system consists of four parts: two links, a support frame, a movable gripper, and a controller box. The robot is attached on the support frame, which is attached at the man-way flange of the pressurizer such that the robot is positioned inside pressurizer. To access arbitrary heater, at first two links horizontally rotate, and then the gripper suspended by two steel wires moves up and down by turing wire drum because the rod heaters are located about 8 meters under the robot and are arranged in two circular rows. The robot must be designed under several constraints such as its weight and collision with pressurized wall or spray nozzle because the robot is positioned and moves inside the pressurizer. To verify that the designed robot is free from collision during installation procedure and it can access any desired rod heater, it is simulated by 3-dimensional graphic software (RobCAD). For evaluating stress of the support frame finite element analysis is performed by using the ANSYS code

PERFORMANCE CHARACTERISTICS OF PARABOLIC SOLAR COLLECTOR WATER HEATER SYSTEM FITTED WITH NAIL TWISTED TAPES ABSORBER

Directory of Open Access Journals (Sweden)

K. SYED JAFAR

2017-03-01

Full Text Available In this paper, the experimental heat transfer, friction loss and thermal performance data for water flowing through the absorber tube fitted with two different twisted tape configurations in parabolic trough collector (PTC are presented. In the present work, a relative experimental study is carried out to investigate the performance of a PTC influenced by heat transfer through fluidabsorber wall mixing mechanism. The major findings of this experiment show that heat transport enhancement in the nail twisted tape collector perform significantly better than plain twisted tapes and also show that the smallest twisted tape ratio enhances the system performance remarkably maximizing the collector efficiency. The results suggest that the twisted tape and nail twisted tape would be a better option for high thermal energy collection in laminar region of the PTC system.

Experimental study on split air conditioner with new hybrid equipment of energy storage and water heater all year round

International Nuclear Information System (INIS)

Wang Shaowei; Liu Zhenyan; Li Yuan; Zhao Keke; Wang Zhigang

2005-01-01

This paper presents a split air conditioner with a new hybrid equipment of energy storage and water heater all year round (ACWES). The authors made a special design on the storage tank to adjust the refrigerant capacity in the storage coils under different functions, instead of adding an accumulator to the system. An ACWES prototype, rebuilt from an original split air conditioner, has been finished, and experimental study of the operation processes of the prototype was done from which some important conclusions and suggestions have been made, which were helpful in the primary design and improvement of an ACWES system for potential users

MD#1826: Measurement of Quench Heater vertical kick

CERN Document Server

Valette, Matthieu; Lindstrom, Bjorn Hans Filip; Bortot, Lorenzo; Fernandez Navarro, Alejandro; Schmidt, Rudiger; Verweij, Arjan

2018-01-01

Following the observation of vertical orbit oscillations of the LHC beam between the detection of a (beam induced) quench of an LHC main dipole and the beam dump, a study was started to verify that the orbit distortions are caused by the firing of the quench heaters (QH). Simulation of the magnetic field generated by the discharge of the QH and its effect on the beam confirmed it was the most likely cause. A dedicated experiment with 450 GeV proton beams was performed to validate the simulation results. The results are presented below and compared to the simulations. Furthermore, estimates on the effect of quench heater firing in superconducting magnets other than the studied LHC main dipoles on the circulating proton beams in LHC and the future HL-LHC are discussed.

Heater improves cold-temperature capacity of silver-cadmium batteries

Science.gov (United States)

Webster, W. H., Jr.; Jackson, T. P.

1975-01-01

Eight heaters are included in 14-cell package to provide 14-Vdc. Each heater is 11-ohm self-adhesive strip placed across broad face of each pair of cells. They are installed before cells are wired. Heaters are in series and are connected through pair of redundant thermostats.

Multi-step heater deployment in a subsurface formation

Science.gov (United States)

Mason, Stanley Leroy [Allen, TX

2012-04-03

A method for installing a horizontal or inclined subsurface heater includes placing a heating section of a heater in a horizontal or inclined section of a wellbore with an installation tool. The tool is uncoupled from the heating section. A lead in section is mechanically and electrically coupled to the heating section of the heater. The lead-in section is located in an angled or vertical section of the wellbore.

Heater experiments in the Climax Stock, Nevada Test Site

International Nuclear Information System (INIS)

Ramspott, L.; Ballou, L.

1977-01-01

The Climax Stock is a composite granitic intrusive at the Nevada Test Site, with an existing shaft and an open drift about 1400 ft. below the surface. In September 1977, the Lawrence Livermore Laboratory plans to operate three in-situ heater experiments in this area. The first experiment consists of a single heater surrounded by thermocouples at distances of from 1/10 to 5 meters. The close spacing will scale down the time required for useful thermal measurements. The heater, which is 3 meters long and capable of about 3 kW, will be energized for a month, turned off for a month, and the cycle repeated. The rock surface temperature in the heater hole is not expected to exceed 500 to 600 0 C, and the temperature beyond 0.1 m into the rock is not expected to exceed 400 0 C. Measurements will be taken during all four months. These measurements will be compared with numerical simulations to determine the thermal properties of the medium. The second experiment, also involving only a single heater, will be more completely instrumented to include the measurement of permeability, rock displacement, stress/strain, and possibly acoustic emission measurements. The scale of the experiment will be larger, and the heater will be energized continuously for about 4 months. The third test in the series is envisioned to be a scale-up of the second, except that multiple heaters will be used. These heaters will be energized for about a year. They will be arranged around a pillar structure left in the room to obtain information on mine stability in the presence of multiple heaters

Development of the robot for pressurizer electric heater inspection and repairing

International Nuclear Information System (INIS)

Jung, Seung Ho; Kim, Seung Ho; Su, Yong Chil

1998-01-01

In this study a robot system has been developed for inspection and maintenance of the pressurizer and the rod heater. The developed robot system consists of four parts: two links, a support frame, a movable gripper, and a controller box. The robot is attached on the support frame, which is attached at the man-way flange of the pressurizer such that the robot is positioned inside pressurizer. To access arbitrary heater, at first two links horizontally rotate, and then the gripper suspended by two steel wires moves up and down by turing wire drum because the rod heaters are located about 8 meters under the robot and are arranged in two circular rows. The robot must be designed under several constraint such as its weight and collision with pressurizer wall or spray nozzle because the robot is positioned and moves inside the pressurizer. To verify that the designed robot is free from collision during installation procedure and it can access any desired rod heater, it is simulated by 3-dimensional graphic software (RobCAD). For evaluating stress of the support frame finite element analysis is performed by using the ANSYS code. For gripping the rod heater the passive self-locking mechanism is adopted, which is made up three balls and springs. Because the mechanism is very simple, it is very hardly defected than that adopted motor. (author). 11 refs., 8 tabs., 13 figs

Determination of inorganic compounds in drinking water on the basis of house water heater scale, part 1: Determination of heavy metals and uranium

Directory of Open Access Journals (Sweden)

Rajković Miloš B.

2004-01-01

Full Text Available The analysis of scale originated from drinking water on the house water heater, showed that scale is basically calcium carbonate that crystallizes hexagonally in the form of calcite. Scale taken as a sample from different spots in Belgrade – upper town of Zemun (sample 1 and Pančevo (sample 2 showed different configuration although it came from the same waterworks. That indicates either that the water flowing through waterworks pipes in different parts of the city is not the same or the waterworks net is not the same (age, maintaining, etc. All the elements which are dominant in drinking water (Ca, Mg, K, and Na, and which could be found in water by natural processes, are by their content far below the values regulated by law. The analysis also showed the presence of many metals: Ti, Pb, Zn, Cu Li, Sr, Cd, and Cr in the first sample, which are not found in the scale taken near Pančevo. The results obtained by calculating the mass concentration in drinking water on the basis of scale content, showed that both waters belonged to the category of low mineral waters. Contents of inorganic substances in these waters (117.85 mg/dm3 for sample 1 or 80.83 mg/dm3 for sample 2 are twice lower than the values predicted by the legislation. Gammaspectrometric analysis indicates the presence of radioactive elements – uranium and strontium which can influence human health.

Test results and supporting analysis of a near-surface heater experiment in the Eleana argillite

International Nuclear Information System (INIS)

McVey, D.F.; Lappin, A.R.; Thomas, R.K.

1979-01-01

A preliminary evaluation of the in-situ thermomechanical response of argillite to heating was obtained from a near-surface heater test in the Eleana Formation, at the United States Department of Energy, Nevada Test Site. The experiment consisted of a 3.8 kW, 3-m long x 0.3-m diameter electrical heater in a central hole surrounded by peripheral holes containing instrumentation to measure temperature, gas pressures, and vertical displacement. A thermal model of the experiment agreed well with experimental results; a comparison of measured and predicted temperatures indicates that some nonmodeled vertical transport of water and water vapor occurred near the heater, especially at early times. A mechanical model indicated that contraction of expandable clays in the argillite produced a region 1.5 - 2.0 m in radius, in which opening of preexisting joints occurred as a result of volumetric contraction. Results of thermal and mechanical modeling, laboratory property measurements, experimental temperature measurements, and post-test observations are all self-consistent and provide preliminary information on the in-situ response of argillaceous rocks to the emplacement of heat-producing nuclear waste

Heater rod temperature change at boiling transition under flow oscillation

International Nuclear Information System (INIS)

Kasai, Shigeru; Toba, Akio; Takigawa, Yukio; Ebata, Shigeo; Morooka, Shin-ichi; Shirakawa, Ken-etsu; Utsuno, Hideaki.

1986-01-01

The experiments were performed to investigate the boiling transition phenomenon under flow oscillation (OSBT) during thermal hydraulic instability. It was found, from the experimental results, that the thermal hydraulic instability did not immediately lead to the boiling transition (BT) and, even when the BT occurred due to a power increase, the change in the heater rod temperature was periodically up and down with a saw-toothed shape and no excursion occurred. To investigate the temperature change characteristics, an analysis was also performed using the transient thermal hydraulics code. The analytical results showed that the shape of the heater rod temperature change was well simulated by presuming a repeat of alternate BT and rewetting. Based on these results, further analysis has been performed with the lumped parameter model to investigate the temperature profile characteristics as well as the effects of the post-BT heat transfer coefficient and the flow oscillation period on the maximum temperature. (author)

Local Adaptive Control of Solar Photovoltaics and Electric Water Heaters for Real-time Grid Support

DEFF Research Database (Denmark)

Bhattarai, Bishnu Prasad; Mendaza, Iker Diaz de Cerio; Bak-Jensen, Birgitte

2016-01-01

Overvoltage (OV) in a low voltage distribution network is one of the foremost issues observed even under moderate penetration of rooftop solar photovoltaics (PVs). Similarly, grid under-voltage (UV) is foreseen as a potential issue resulting from increased integration of large flexible loads......, such as electric vehicles, electric water heaters (EWHs) etc. An adaptive control using only local measurements for the EWHs and PVs is proposed in this study to alleviate OV as well as UV issues. The adaptive control is designed such that it monitors the voltage at the point of connection and adjusts active...... and reactive power injection/consumptions of the EWHs and PVs following the voltage violations. To effectively support the network in real-time, the controller allows EWHs to operate prior to PVs in OV and after the PVs in UV violations. The effectiveness of the proposed control strategy is demonstrated...

Investigations on the performance of a double pass, hybrid - type (PV/T) solar air heater

Energy Technology Data Exchange (ETDEWEB)

Srinivas, M.; Jayaraj, S. [Department of Mechanical Engineering, National Institute of Technology, Calicut-673601 (India)

2013-07-01

A solar hybrid energy system having photovoltaic and thermal (PV/T) devices, which produces both thermal and electrical energies simultaneously is considered for analysis. A double pass hybrid solar air (PV/T) heater with slats is designed and fabricated to study its thermal and electrical performance. Air as a heat removing fluid is made to flow through upper and lower channels of the collector. The collector is designed in such a way that the absorber plate is partially covered by solar cells. The raise in temperature of the solar cell is expected to decrease its electrical performance. Thin metallic strips called slats are attached longitudinally at the bottom side of the absorber plate to improve the system performance by increasing the cooling rate of the absorber plate. Thermal and electrical performances of the whole system at varying cooling conditions are presented. An artificial neural network model is used for forecasting the system performance at any desired conditions. The proposed model can be successfully used for evaluating the effect of different operating parameters under different ambient conditions for predicting the overall performance of the system.

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.

Alternative for Summer Use of Solar Air Heaters in Existing Buildings

Directory of Open Access Journals (Sweden)

Sergio L. González-González

2017-07-01

Full Text Available Among solar thermal technologies for indoor heating, solar air heaters (SAH are appealing for implementation on existing buildings due to their simplicity, fewer risks related to the working fluid, and possible independence from the building structure. However, existing research work mainly focuses on winter use and still fails in providing effective solutions for yearly operation, which would enhance their interest. With the aim of analysing an alternative summer use, this work firstly characterises a double channel-single pass solar air collector through experimentation. From the obtained results, modelling and simulation tasks have been conducted to evaluate the possibilities of using hot air, provided by the SAH, while operating under summer conditions within a closed loop, to feed an air-to-water heat exchanger for domestic hot water (DHW production. The system is studied through simulation under two different configurations for a case study in Valladolid (Spain, during the period from May to September for different airflows in the closed loop. Results show that daily savings can vary from 27% to 85% among the different operating conditions; a configuration where make-up water is fed to the heat exchanger being preferable, with a dedicated water tank for the solar heated water storage of the minimum possible volume. The more favourable results for the harshest months highlight the interest of extending the use of the solar air heaters to the summer period.

Leak Detection of High Pressure Feedwater Heater Using Empirical Models

International Nuclear Information System (INIS)

Lee, Song Kyu; Kim, Eun Kee; Heo, Gyun Young; An, Sang Ha

2009-01-01

Even small leak from tube side or pass partition within the high pressure feedwater heater (HPFWH) causes a significant deficiency in its performance. Plant operation under the HPFWH leak condition for long time will result in cost increase. Tube side leak within HPFWH can produce the high velocity jet of water and it can cause neighboring tube failures. However, most of plants are being operated without any information for internal leaks of HPFWH, even though it is prone to be damaged under high temperature and high pressure operating conditions. Leaks from tubes and/or pass partition of HPFWH occurred in many nuclear power plants, for example, Mihama PS-2, Takahama PS-2 and Point Beach Nuclear Plant Unit 1. If the internal leaks of HPFWH are monitored, the cost can be reduced by inexpensive repairs relative to loss in performance and moreover plant shutdown as well as further tube damages can be prevented

Analysis of polymer foil heaters as infrared radiation sources

International Nuclear Information System (INIS)

Witek, Krzysztof; Piotrowski, Tadeusz; Skwarek, Agata

2012-01-01

Infrared radiation as a heat source is used in many fields. In particular, the positive effect of far-infrared radiation on living organisms has been observed. This paper presents two technological solutions for infrared heater production using polymer-silver and polymer-carbon pastes screenprinted on foil substrates. The purpose of this work was the identification of polymer layers as a specific frequency range IR radiation sources. The characterization of the heaters was determined mainly by measurement of the surface temperature distribution using a thermovision camera and the spectral characteristics were determined using a special measuring system. Basic parameters obtained for both, polymer silver and polymer carbon heaters were similar and were as follows: power rating of 10–12 W/dm 2 , continuous working surface temperature of 80–90 °C, temperature coefficient of resistance (TCR) about +900 ppm/K for polymer-carbon heater and about +2000 ppm/K for polymer-silver, maximum radiation intensity in the wavelength range of 6–14 μm with top intensity at 8.5 μm and heating time about 20 min. For comparison purposes, commercial panel heater was tested. The results show that the characteristics of infrared polymer heaters are similar to the characteristics of the commercial heater, so they can be taken into consideration as the alternative infrared radiation sources.

Experimental study of heat transfer and thermal performance with longitudinal fins of solar air heater

Directory of Open Access Journals (Sweden)

Foued Chabane

2014-03-01

Full Text Available The thermal performance of a single pass solar air heater with five fins attached was investigated experimentally. Longitudinal fins were used inferior the absorber plate to increase the heat exchange and render the flow fluid in the channel uniform. The effect of mass flow rate of air on the outlet temperature, the heat transfer in the thickness of the solar collector, and the thermal efficiency were studied. Experiments were performed for two air mass flow rates of 0.012 and 0.016 kg s−1. Moreover, the maximum efficiency values obtained for the 0.012 and 0.016 kg s−1 with and without fins were 40.02%, 51.50% and 34.92%, 43.94%, respectively. A comparison of the results of the mass flow rates by solar collector with and without fins shows a substantial enhancement in the thermal efficiency.

Experimental study of heat transfer and thermal performance with longitudinal fins of solar air heater.

Science.gov (United States)

Chabane, Foued; Moummi, Noureddine; Benramache, Said

2014-03-01

The thermal performance of a single pass solar air heater with five fins attached was investigated experimentally. Longitudinal fins were used inferior the absorber plate to increase the heat exchange and render the flow fluid in the channel uniform. The effect of mass flow rate of air on the outlet temperature, the heat transfer in the thickness of the solar collector, and the thermal efficiency were studied. Experiments were performed for two air mass flow rates of 0.012 and 0.016 kg s(-1). Moreover, the maximum efficiency values obtained for the 0.012 and 0.016 kg s(-1) with and without fins were 40.02%, 51.50% and 34.92%, 43.94%, respectively. A comparison of the results of the mass flow rates by solar collector with and without fins shows a substantial enhancement in the thermal efficiency.

Characterization of large cadmium zinc telluride crystals grown by traveling heater method

DEFF Research Database (Denmark)

Chen, H.; Awadalla, S.A.; Iniewski, K.

2008-01-01

The focus of this paper is to evaluate thick, 20 X 20 X 10 and 10 X 10 X 10 mm(3), cadmium zinc telluride (CZT), Cd0.9Zn0.1Te, crystals grown using the traveling heater method (THIM). The phenomenal spectral performance and small size and low concentration of Te inclusions/precipitates of these c......The focus of this paper is to evaluate thick, 20 X 20 X 10 and 10 X 10 X 10 mm(3), cadmium zinc telluride (CZT), Cd0.9Zn0.1Te, crystals grown using the traveling heater method (THIM). The phenomenal spectral performance and small size and low concentration of Te inclusions...