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

Directory of Open Access Journals (Sweden)

Zhongchao Zhao

2018-05-01

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

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

Institute of Scientific and Technical Information of China (English)

王芳; 郑茂余; 邵俊鹏; 李忠建

2008-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2003-12-01

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

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

Directory of Open Access Journals (Sweden)

Wessam El-Baz

2018-05-01

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

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

International Nuclear Information System (INIS)

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

2015-01-01

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

Current status of ground-source heat pumps in China

International Nuclear Information System (INIS)

Yang Wei; Zhou Jin; Xu Wei; Zhang Guoqiang

2010-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

1980-11-12

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

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

Science.gov (United States)

Pei, Guihong; Zhang, Liyin

2016-01-01

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

Ground source thermo-pumps for individual residential houses; Les thermopompes a capteur enterres dans les residences individuelles

Energy Technology Data Exchange (ETDEWEB)

Ossant, G. [Societe Syrec (France)

1997-12-31

The main principles, performances and constraints of the various types of ground source thermo-pumps for individual houses, i.e. ground/ground thermo-pumps, glycol water/water thermo-pumps and ground/water thermo-pumps are reviewed, and their energy consumptions are discussed. The design and operating conditions of a reverse ground source thermo-pump (Syrec) for space heating and air conditioning through a hot and cold floor system and a Syrec ground source thermo-pump for water heating, are presented

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...

Characterization of Site for Installing Open Loop Ground Source Heat Pump System

Science.gov (United States)

Yun, S. W.; Park, Y.; Lee, J. Y.; Yi, M. J.; Cha, J. H.

2014-12-01

This study was conducted to understand hydrogeological properties of site where open loop ground source heat pump system will be installed and operated. Groundwater level and water temperature were hourly measured at the well developed for usage of open loop ground source heat pump system from 11 October 2013 to 8 January 2014. Groundwater was sampled in January and August 2013 and its chemical and isotopic compositions were analyzed. The bedrock of study area is the Jurassic granodiorite that mainly consists of quartz (27.9 to 46.8%), plagioclase (26.0 to 45.5%), and alkali feldspar (9.5 to 18.7%). The groundwater level ranged from 68.30 to 68.94 m (above mean sea level). Recharge rate was estimated using modified watertable fluctuation method and the recharge ratios was 9.1%. The water temperature ranged from 14.8 to 15.0oC. The vertical Increase rates of water temperature were 1.91 to 1.94/100 m. The water temperature showed the significant seasonal variation above 50 m depth, but had constant value below 50 m depth. Therefore, heat energy of the groundwater can be used securely in open loop ground source heat pump system. Electrical conductivity ranged from 120 to 320 µS/cm in dry season and from 133 to 310 µS/cm in wet season. The electrical conductivity gradually decreased with depth. In particular, electrical conductivity in approximately 30 m depth decreased dramatically (287 to 249 µS/cm) in wet season. The groundwater was Ca-HCO3 type. The concentrations of dissolved components did not show the vertically significant variations from 0 to 250 m depth. The δ18O and δD ranged from -9.5 to -9.4‰ and from -69 to -68‰. This work is supported by the New and Renewable Energy of the Korea Institute of Energy Technology Evaluation and Planning (KETEP) grant funded by the Korea government Ministry of Knowledge Economy (No.20123040110010).

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

International Nuclear Information System (INIS)

Hadley, Donald L

2001-01-01

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

Geothermal energy. Ground source heat pumps

International Nuclear Information System (INIS)

2009-01-01

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

North Village Ground Source Heat Pump Demonstration Project

Energy Technology Data Exchange (ETDEWEB)

Redderson, Jeff

2015-08-03

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

In situ study of the effect of ground source heat pump on shallow ground-water quality in the late Pleistocene terrace area of Tokyo, Japan

Science.gov (United States)

Takemura, T.; Uemura, K.; Akiba, Y.; Ota, M.

2015-12-01

The implementation of ground source heat pump (GSHP) systems has rapidly increased around the world, since they reduce carbon dioxide emissions and save electric energy. The GSHP system transfer heat into the geosphere zone when air conditioners are used to cool rooms or buildings. However, the effects of temperature increase on the quality of underground water has yet to be fully investigated. In order to reduce the risks of ground-water pollution by the installed GSHPs, it is important to evaluate the effect of temperature change on the ground-water quality. In this study, we installed a closed loop GSHP system on a heat exchange well along with a monitoring well drilled to measure ground-water quality and temperature. The monitoring well was drilled at 0.1cm away from the heat exchange well. We observed that changes of temperature in the heat exchange well affected the water quality, especially turbidity, in gravelly layer.

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

International Nuclear Information System (INIS)

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

2014-01-01

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

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.

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

International Nuclear Information System (INIS)

Jalaluddin; Miyara, Akio

2015-01-01

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

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

Science.gov (United States)

Qin, Zenghu; Tong, Mingwei; Kun, Lin

2012-01-01

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

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

International Nuclear Information System (INIS)

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

2017-01-01

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

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

International Nuclear Information System (INIS)

An Qiang

2011-01-01

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

Ground Source Integrated Heat Pump (GS-IHP) Development

Energy Technology Data Exchange (ETDEWEB)

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

2013-05-24

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

Finite Volume Based Computer Program for Ground Source Heat Pump System

Energy Technology Data Exchange (ETDEWEB)

Menart, James A. [Wright State University

2013-02-22

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

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

Science.gov (United States)

Yin, Baoquan; Wu, Xiaoting

2018-02-01

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

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

Science.gov (United States)

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

2017-11-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2017-04-24

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

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

Energy Technology Data Exchange (ETDEWEB)

NONE

2009-07-01

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

Ground-source heat pump barometer

International Nuclear Information System (INIS)

Anon.

2011-01-01

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

Geothermal heat pumps - Trends and comparisons

Energy Technology Data Exchange (ETDEWEB)

Lund, John W

1989-01-01

Heat pumps are used where geothermal water or ground temperatures are only slightly above normal, generally 50 to 90 deg. F. Conventional geothermal heating (and cooling) systems are not economically efficient at these temperatures. Heat pumps, at these temperatures, can provide space heating and cooling, and with a desuperheater, domestic hot water. Two basic heat pump systems are available, air-source and water- or ground-source. Water- and ground-coupled heat pumps, referred to as geothermal heat pumps (GHP), have several advantages over air-source heat pumps. These are: (1) they consume about 33% less annual energy, (2) they tap the earth or groundwater, a more stable energy source than air, (3) they do not require supplemental heat during extreme high or low outside temperatures, (4) they use less refrigerant (freon), and (5) they have a simpler design and consequently less maintenance.

Exergy analysis of a two-stage ground source heat pump with a vertical bore for residential space conditioning under simulated occupancy

International Nuclear Information System (INIS)

Ally, Moonis R.; Munk, Jeffrey D.; Baxter, Van D.; Gehl, Anthony C.

2015-01-01

Highlights: • Exergy and energy analysis of a vertical-bore ground source heat pump over a 12-month period is presented. • The ground provided more than 75% of the heating energy. • Performance metrics are presented. • Sources of systemic inefficiency are identified and prioritized using Exergy analysis. • Understanding performance metrics is vital for judicial use of renewable energy. - Abstract: This twelve-month field study analyzes the performance of a 7.56 W (2.16-ton) water-to-air-ground source heat pump (WA-GSHP) to satisfy domestic space conditioning loads in a 253 m 2 house in a mixed-humid climate in the United States. The practical feasibility of using the ground as a source of renewable energy is clearly demonstrated. Better than 75% of the energy needed for space heating was extracted from the ground. The average monthly electricity consumption for space conditioning was only 40 kW h at summer and winter thermostat set points of 24.4 °C and 21.7 °C, respectively. The WA-GSHP shared the same 94.5 m vertical bore ground loop with a separate water-to-water ground-source heat pump (WW-GSHP) for meeting domestic hot water needs in the same house. Sources of systemic irreversibility, the main cause of lost work, are identified using Exergy and energy analysis. Quantifying the sources of Exergy and energy losses is essential for further systemic improvements. The research findings suggest that the WA-GSHPs are a practical and viable technology to reduce primary energy consumption and greenhouse gas emissions under the IECC 2012 Standard, as well as the European Union (EU) 2020 targets of using renewable energy resources

Simulation and optimisation of a ground source heat pump with different ground heat exchanger configurations for a single-family residential house

DEFF Research Database (Denmark)

Pavlov, Georgi Krasimiroy; Olesen, Bjarne W.

2012-01-01

In the future there will be an increased demand for energy efficient cooling of residential buildings. Therefore it is essential to develop cooling concepts that are passive and/or using very little primary energy. A possible solution is a ground source heat pump combined with a low-temperature h....... For the studied geographical location, passive cooling by bypassing the heat pump and using only the ground heat exchanger can provide acceptable room temperatures.......In the future there will be an increased demand for energy efficient cooling of residential buildings. Therefore it is essential to develop cooling concepts that are passive and/or using very little primary energy. A possible solution is a ground source heat pump combined with a low......-temperature heating and high-temperature cooling system. The present work evaluates the performance in relation to thermal comfort and energy consumption of a GSHP with different GHE concepts. The different configurations are analyzed being part of the energy supply system of a low-energy residential house...

Ground Source Geothermal District Heating and Cooling System

Energy Technology Data Exchange (ETDEWEB)

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

2016-10-21

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2013-11-01

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

Energy consumption modeling of air source electric heat pump water heaters

International Nuclear Information System (INIS)

Bourke, Grant; Bansal, Pradeep

2010-01-01

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

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

Directory of Open Access Journals (Sweden)

Md. Hasan Ali

2017-10-01

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

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

International Nuclear Information System (INIS)

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

1993-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2011-07-01

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

Seasonal coefficient of performance for ground source heat pump and groundwater one in Białystok

Science.gov (United States)

Gajewski, Andrzej

2017-11-01

European Economic Area (EEA) states declare to contain greenhouse gases emissions at 20% by 2020, whereas European Union (EU) does 40% before 2030, which result in encouragement to apply low-carbon technologies. Coefficient of Performance (COP) and Seasonal Coefficient of Performance (SCOPnet) are obtained using temperature measurement done by The Institute of Meteorology and Water Management - National Research Institute (IMGW-PIB) at the weather station in Bialystok for ten-year period. The first variant is ground source heat pump (GSHP) and the second one is groundwater source heat pump (WSHP) which can be equipped with separating heat exchanger (SHE) optionally. In both cases heat is generated for heating system only. Ground temperature is determined from Baggs (1983) formula using Oleśkowicz-Popiel et. al. (2002) adaptation to Polish climate and substituting the local constants achieved by Biernacka (2010). Water temperature in a groundwater basin is obtained from Kowalski (2007) equation. Estimation is done in each hour of heating season. All COP values are higher than 3.5 required by EU (2013). SCOPnet are as follows: 6.12, 5.86, 5.03 for WSHP, WSHP+SHE, GSHP respectively. Insomuch as WSHP needs only two boreholes it is recommended to the areas beneath ones a groundwater basin is located.

Seasonal coefficient of performance for ground source heat pump and groundwater one in Białystok

Directory of Open Access Journals (Sweden)

Gajewski Andrzej

2017-01-01

Full Text Available European Economic Area (EEA states declare to contain greenhouse gases emissions at 20% by 2020, whereas European Union (EU does 40% before 2030, which result in encouragement to apply low-carbon technologies. Coefficient of Performance (COP and Seasonal Coefficient of Performance (SCOPnet are obtained using temperature measurement done by The Institute of Meteorology and Water Management – National Research Institute (IMGW-PIB at the weather station in Bialystok for ten-year period. The first variant is ground source heat pump (GSHP and the second one is groundwater source heat pump (WSHP which can be equipped with separating heat exchanger (SHE optionally. In both cases heat is generated for heating system only. Ground temperature is determined from Baggs (1983 formula using Oleśkowicz-Popiel et. al. (2002 adaptation to Polish climate and substituting the local constants achieved by Biernacka (2010. Water temperature in a groundwater basin is obtained from Kowalski (2007 equation. Estimation is done in each hour of heating season. All COP values are higher than 3.5 required by EU (2013. SCOPnet are as follows: 6.12, 5.86, 5.03 for WSHP, WSHP+SHE, GSHP respectively. Insomuch as WSHP needs only two boreholes it is recommended to the areas beneath ones a groundwater basin is located.

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

Energy Technology Data Exchange (ETDEWEB)

James A Menart, Professor

2013-02-22

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

Energetic Efficiency Evaluation by Using GroundWater Heat Pumps

Directory of Open Access Journals (Sweden)

Tokar Adriana

2012-09-01

Full Text Available Romania has significant energy potential from renewable sources, but the potential used is much lower due to technical and functional disadvantages, to economic efficiency, the cost elements and environmental limitations. However, efforts are being made to integrate renewable energy in the national energy system. To promote and encourage private investments for renewable energy utilization, programs have been created in order to access funds needed to implement these technologies. Assessment of such investments was carried out from technical and economical point of view, by analyzing a heat pump using as heat source the solar energy from the ground.

HEAT PUMP USING SUBSOIL WATERS AS LOW TEMPERATURE HEAT SOURCE

Directory of Open Access Journals (Sweden)

Denysova Alla

2015-08-01

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

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

Science.gov (United States)

Casasso, Alessandro; Sethi, Rajandrea

2014-05-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

1997-11-25

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

IEA HPP Annex 29 - ground-source heat pumps overcoming technical and market barriers. Status report Norway

International Nuclear Information System (INIS)

Stene, Joern

2004-12-01

Norway is a member of Annex 29, 'Ground-Source Heat Pump Systems Overcoming Technical and Market Barriers' (2004-2006), organized under the umbrella of the International Energy Agency (IEA) and the IEA Heat Pump Programme (HPP). The 7 participating countries are Austria (Operating Agent), Canada, Japan, Norway, Spain, Sweden and the USA. The Norwegian participation is financed by ENOVA SF, and SINTEF Energy Research is responsible for planning and carrying out the Norwegian activities. This report provides a status for ground-source heat pump (GSHP) systems in Norway with regard to state-of-the-art technology, installation examples, geological data, costs and market opportunities. A Norwegian Internet home page for ground-source heat pump systems (www.energy.sintef.no/prosjekt/Annex29) is also presented. GSHP systems in Norway are classified as direct systems (groundwater and soil/ground) and indirect closed-loop systems (vertical-rock and horizontal-soil/ground). The vast majority of the installations are indirect closed-loop systems utilizing vertical boreholes in rock as a heat source, heat sink and thermal energy storage. GSHP systems are relatively capital intensive installations, but they achieve high energy efficiency due to the relatively high and stable heat source temperature and the fact that a considerable share of the cooling demand in non-residential buildings can be covered by means of free cooling. In order to obtain energy efficient and reliable GSHP installations, it is important to implement a total quality concept where focus is on quality and system integration during all stages of the project. A life cycle analysis (LCA) will be an important tool in such a concept, since both the investment costs as well as the lifetime operational and maintenance costs are included (author) (ml) Litt usikker pae tag 620- ikke en vanlig sintef rapportkode

A review of the cylindrical heat source method for the design and analysis of vertical ground-coupled heat pump systems

Energy Technology Data Exchange (ETDEWEB)

Bernier, M. [Ecole Polytechnique, Montreal, PQ (Canada). Dept. de Genie Mecanique

2000-12-01

The successful design and analysis of ground-coupled heat pump (GCHP) systems depends in large part on the adequate prediction of ground water heat transfer. The author presented a detailed review of the cylindrical heat source method utilized for the prediction of transient heat transfer in vertical U-tube ground heat exchangers. The physics that underlies the theory applicable to this technology is explained in a step-by-step manner. Explanations are also provided for the equations that govern the determination of design lengths for the cylindrical heat method, as presented in the ASHRAE handbook. Some improvements were recommended by the author, such as the calculation of the effective thermal resistances using the borehole diameter instead of the equivalent U-tube diameter now in use. Annual hour-by-hour building load calculations should be used to calculate ground loads. 8 refs., 2 tabs., 5 figs., 3 appendices.

Thermal-economic modeling and optimization of vertical ground-coupled heat pump

Energy Technology Data Exchange (ETDEWEB)

Sanaye, Sepehr; Niroomand, Behzad [Energy Systems Improvement Laboratory (ESIL), Department of Mechanical Engineering, Iran University of Science and Technology (IUST), Narmak, Tehran 16488 (Iran)

2009-04-15

The optimal design process of a ground source heat pump includes thermal modeling of the system and selection of optimal design parameters which affect the system performance as well as initial and operational costs. In this paper, the modeling and optimizing processes of a ground-coupled heat pump (GCHP) with closed vertical ground heat exchanger (VGHX) are presented. To verify the modeling procedure of heat pump and VGHX systems, the simulation outputs were compared with the corresponding values reported in the literature and acceptable accuracy was obtained. Then an objective function (the sum of annual operating and investment costs of the system) was defined and minimized, exposed to the specified constraints to estimate the optimum design parameters (decision variables). Two Nelder-Mead and genetic algorithm optimization techniques were applied to guarantee the validity of the optimization results. For the given heating/cooling loads and various climatic conditions, the optimum values of heat pump design parameters (saturated temperature/pressure of condenser and evaporator) as well as VGHX design parameters (inlet and outlet temperatures of the ground water source, pipe diameter, depth and number of boreholes) were predicted. Furthermore, the sensitivity analysis of change in the total annual cost of the system and optimum design parameters with the climatic conditions, cooling/heating capacity, soil type, and number of boreholes were discussed. Finally, the sensitivity analysis of change in optimum design parameters with increase in the investment and electricity costs was performed. (author)

Thermal-economic modeling and optimization of vertical ground-coupled heat pump

International Nuclear Information System (INIS)

Sanaye, Sepehr; Niroomand, Behzad

2009-01-01

The optimal design process of a ground source heat pump includes thermal modeling of the system and selection of optimal design parameters which affect the system performance as well as initial and operational costs. In this paper, the modeling and optimizing processes of a ground-coupled heat pump (GCHP) with closed vertical ground heat exchanger (VGHX) are presented. To verify the modeling procedure of heat pump and VGHX systems, the simulation outputs were compared with the corresponding values reported in the literature and acceptable accuracy was obtained. Then an objective function (the sum of annual operating and investment costs of the system) was defined and minimized, exposed to the specified constraints to estimate the optimum design parameters (decision variables). Two Nelder-Mead and genetic algorithm optimization techniques were applied to guarantee the validity of the optimization results. For the given heating/cooling loads and various climatic conditions, the optimum values of heat pump design parameters (saturated temperature/pressure of condenser and evaporator) as well as VGHX design parameters (inlet and outlet temperatures of the ground water source, pipe diameter, depth and number of boreholes) were predicted. Furthermore, the sensitivity analysis of change in the total annual cost of the system and optimum design parameters with the climatic conditions, cooling/heating capacity, soil type, and number of boreholes were discussed. Finally, the sensitivity analysis of change in optimum design parameters with increase in the investment and electricity costs was performed

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

Energy Technology Data Exchange (ETDEWEB)

Mittereder, N.; Poerschke, A.

2013-11-01

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

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

International Nuclear Information System (INIS)

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

2003-01-01

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

TWO-STAGE HEAT PUMPS FOR ENERGY SAVING TECHNOLOGIES

Directory of Open Access Journals (Sweden)

A. E. Denysova

2017-09-01

Full Text Available The problem of energy saving becomes one of the most important in power engineering. It is caused by exhaustion of world reserves in hydrocarbon fuel, such as gas, oil and coal representing sources of traditional heat supply. Conventional sources have essential shortcomings: low power, ecological and economic efficiencies, that can be eliminated by using alternative methods of power supply, like the considered one: low-temperature natural heat of ground waters of on the basis of heat pump installations application. The heat supply system considered provides an effective use of two stages heat pump installation operating as heat source at ground waters during the lowest ambient temperature period. Proposed is a calculation method of heat pump installations on the basis of groundwater energy. Calculated are the values of electric energy consumption by the compressors’ drive, and the heat supply system transformation coefficient µ for a low-potential source of heat from ground waters allowing to estimate high efficiency of two stages heat pump installations.

Simulation of the thermal performance of a hybrid solar-assisted ground-source heat pump system in a school building

Science.gov (United States)

Androulakis, N. D.; Armen, K. G.; Bozis, D. A.; Papakostas, K. T.

2018-04-01

A hybrid solar-assisted ground-source heat pump (SAGSHP) system was designed, in the frame of an energy upgrade study, to serve as a heating system in a school building in Greece. The main scope of this study was to examine techniques to reduce the capacity of the heating equipment and to keep the primary energy consumption low. Simulations of the thermal performance of both the building and of five different heating system configurations were performed by using the TRNSYS software. The results are presented in this work and show that the hybrid SAGSHP system displays the lower primary energy consumption among the systems examined. A conventional ground-source heat pump system has the same primary energy consumption, while the heat pump's capacity is double and the ground heat exchanger 2.5 times longer. This work also highlights the contribution of simulation tools to the design of complex heating systems with renewable energy sources.

Hybrid Ground-Source Heat Pump Installations: Experiences, Improvements, and Tools

Energy Technology Data Exchange (ETDEWEB)

Scott Hackel; Amanda Pertzborn

2011-06-30

One innovation to ground-source heat pump (GSHP, or GHP) systems is the hybrid GSHP (HyGSHP) system, which can dramatically decrease the first cost of GSHP systems by using conventional technology (such as a cooling tower or a boiler) to meet a portion of the peak heating or cooling load. This work uses three case studies (two cooling-dominated, one heating-dominated) to demonstrate the performance of the hybrid approach. Three buildings were studied for a year; the measured data was used to validate models of each system. The models were used to analyze further improvements to the hybrid approach, and establish that this approach has positive impacts, both economically and environmentally. Lessons learned by those who design and operate the systems are also documented, including discussions of equipment sizing, pump operation, and cooling tower control. Finally, the measured data sets and models that were created during this work are described; these materials have been made freely available for further study of hybrid systems.

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

Energy Technology Data Exchange (ETDEWEB)

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

2014-01-01

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

Optimal Ground Source Heat Pump System Design

Energy Technology Data Exchange (ETDEWEB)

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

2015-04-01

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

Energy saving analysis on mine-water source heat pump in a residential district of Henan province, central China

Science.gov (United States)

Wang, Hong; Duan, Huanlin; Chen, Aidong

2018-02-01

In this paper, the mine-water source heat pump system is proposed in residential buildings of a mining community. The coefficient of performance (COP) and the efficiency of exergy are analyzed. The results show that the COP and exergy efficiency of the mine-water source heat pump are improved, the exergy efficiency of mine-water source heat pump is more than 10% higher than that of the air source heat pump.The electric power conservation measure of “peak load shifting” is also emphasized in this article. It shows that itis a very considerable cost in the electric saving by adopting the trough period electricity to produce hot water. Due to the proper temperature of mine water, the mine-watersource heat pump unit is more efficient and stable in performance, which further shows the advantage of mine-water source heat pump in energy saving and environmental protection. It provides reference to the design of similar heat pump system as well.

Crawl space assisted heat pump. [using stored ground heat

Science.gov (United States)

Ternes, M. P.

1980-01-01

A variety of experiments and simulations, currently being designed or underway, to determine the feasibility of conditioning the source air of an air to air heat pump using stored ground heat or cool to produce higher seasonal COP's and net energy savings are discussed. The ground would condition ambient air as it is drawn through the crawl space of a house. Tests designed to evaluate the feasibility of the concept, to determine the amount of heat or cool available from the ground, to study the effect of the system on the heating and cooling loads of the house, to study possible mechanisms which could enhance heat flow through the ground, and to determine if diurnal temperature swings are necessary to achieve successful system performance are described.

太阳能辅助地源热泵供暖实验研究%Experimental study of a solar assisted ground source heat pump for heating

Institute of Scientific and Technical Information of China (English)

赵忠超; 丰威仙; 巩学梅; 米浩君; 成华; 云龙

2014-01-01

An experimental study is performed to determine the performance of the solar assisted ground source heat pump(SAGSHP)by using a solar-ground source heat pump hybrid system in the city of Ningbo. The result shows that comparing with the ground source heat pump(GSHP),when the ratio of solar energy to the whole en-ergy is 41. 9% ,the coefficient of performance( COP)of the heat pump and system can improve 15. 1% and 7. 7% respectively. Therefore,the solar assisted ground source heat pump has a significant performance advan-tage according to the experimental result.%选取宁波某公用建筑的太阳能-地源热泵复合系统为实验系统，对太阳能辅助地源热泵（ solar assisted ground source heat pump，SAGSHP）供暖进行了实验研究.研究结果表明：与单一的地源热泵（ground source heat pump，GSHP）相比，当太阳能承担41.9%负荷时，热泵机组和整个系统的能效比（coefficient of performance，COP）分别提高了15.1%和7.7%， SAGSHP 供暖运行模式具有明显的性能优势.

太阳能耦合地源热泵供暖系统的实验研究%Experimental Study on Heating System of Solar Coupled Ground Source Heat Pump

Institute of Scientific and Technical Information of China (English)

智超英; 赵宇含

2017-01-01

太阳能耦合地源热泵系统的设计以太阳能为辅助、地源热泵为主,最大化地利用太阳能资源,在满足地板采暖制备的情况下,富裕的热量可以补充到生活用水当中.通过实验验证了太阳能耦合地源热泵供暖系统可以有效恢复土壤温度,提高机组性能系数,实现热泵长期稳定的运行.%The design of solar coupled ground source heat pump system is based on solar energy and ground source heat pump.The system can maximize solar energy utilization in the preparation of floor heating.Rich heat can be added to the life water.This paper introduces the solar coupled ground source heat pump heating system.The experiment proves that the system can effectively restore the soil temperature, improve the performance coefficient of the crew, and realize the long-term stable operation of the heat pump.

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

Institute of Scientific and Technical Information of China (English)

Nan Lv; Qing Zhang; Zhenqian Chen; Dongsheng Wu

2017-01-01

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

Cooling performance of a vertical ground-coupled heat pump system installed in a school building

Energy Technology Data Exchange (ETDEWEB)

Hwang, Yujin; Lee, Jae-Keun; Jeong, Young-Man; Koo, Kyung-Min [Department of Mechanical Engineering, Pusan National University, San 30, Jangjeon-Dong, Kumjung-Ku, Busan 609-735 (Korea); Lee, Dong-Hyuk; Kim, In-Kyu; Jin, Sim-Won [LG Electronics, 391-2 Gaeumjeong-dong, Changwon City, Gyeongnam (Korea); Kim, Soo H. [Department of Nanosystems and Nanoprocess Engineering, Pusan National University, San 30, Jangjeon-Dong, Kumjung-Ku, Busan 609-735 (Korea)

2009-03-15

This paper presents the cooling performance of a water-to-refrigerant type ground heat source heat pump system (GSHP) installed in a school building in Korea. The evaluation of the cooling performance has been conducted under the actual operation of GSHP system in the summer of year 2007. Ten heat pump units with the capacity of 10 HP each were installed in the building. Also, a closed vertical typed-ground heat exchanger with 24 boreholes of 175 m in depth was constructed for the GSHP system. To analyze the cooling performance of the GSHP system, we monitored various operating conditions, including the outdoor temperature, the ground temperature, and the water temperature of inlet and outlet of the ground heat exchanger. Simultaneously, the cooling capacity and the input power were evaluated to determine the cooling performance of the GSHP system. The average cooling coefficient of performance (COP) and overall COP of the GSHP system were found to be {proportional_to}8.3 and {proportional_to}5.9 at 65% partial load condition, respectively. While the air source heat pump (ASHP) system, which has the same capacity with the GSHP system, was found to have the average COP of {proportional_to}3.9 and overall COP of {proportional_to}3.4, implying that the GSHP system is more efficient than the ASHP system due to its lower temperature of condenser. (author)

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

Directory of Open Access Journals (Sweden)

Jinshun Wu

2013-01-01

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

Case Study for the ARRA-funded Ground Source Heat Pump Demonstration at Denver Museum of Nature & Science

Energy Technology Data Exchange (ETDEWEB)

Im, Piljae [ORNL; Liu, Xiaobing [ORNL

2016-09-01

High initial costs and lack of public awareness of ground-source heat pump (GSHP) technology are the two major barriers preventing rapid deployment of this energy-saving technology in the United States. Under the American Recovery and Reinvestment Act (ARRA), 26 GSHP projects were competitively selected and carried out to demonstrate the benefits of GSHP systems and innovative technologies for cost reduction and/or performance improvement. This report highlights the findings of a case study of one such GSHP demonstration projects that uses a recycled water heat pump (RWHP) system installed at the Denver Museum of Nature & Science in Denver, Colorado. The RWHP system uses recycled water from the city’s water system as the heat sink and source for a modular water-to-water heat pump (WWHP). This case study was conducted based on the available measured performance data from December 2014 through August 2015, utility bills of the building in 2014 and 2015, construction drawings, maintenance records, personal communications, and construction costs. The annual energy consumption of the RWHP system was calculated based on the available measured data and other related information. It was compared with the performance of a baseline scenario— a conventional VAV system using a water-cooled chiller and a natural gas fired boiler, both of which have the minimum energy efficiencies allowed by ASHRAE 90.1-2010. The comparison was made to determine energy savings, operating cost savings, and CO2 emission reductions achieved by the RWHP system. A cost analysis was performed to evaluate the simple payback of the RWHP system. Summarized below are the results of the performance analysis, the learned lessons, and recommended improvement in the operation of the RWHP system.

Ground-source heat pump barometer - EurObserv'ER - September 2011

International Nuclear Information System (INIS)

2011-09-01

2,9% slide by the GHSP market in the EU between 2009 and 2010. The double whammy dealt by the economic crisis and housing slump has stifled expansion of the ground-source heat pump market in many European countries. The European Union market contracted for the second year running (by 2.9% between 2009 and 2010), and this despite the fact that more than 100 000 units were sold over the twelve-month period, taking the number of installed units past the one million mark

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

Energy Technology Data Exchange (ETDEWEB)

Im, Piljae [ORNL; Liu, Xiaobing [ORNL

2015-09-01

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

Geothermal heat pumps - gaining ground in the UK and worldwide

International Nuclear Information System (INIS)

Curtis, Robin

2001-01-01

This 2001 edition of the guide to UK renewable energy companies examines the geothermal heat pump sector, and discusses the technology involved, installations of geothermal heat pumps, the activity in the UK market with increased interest in UK geothermal heat pump products from abroad, and developments in the building sector. The UK government's increased support for the industry including its sponsorship of the Affordable Warmth programme, and the future potential of ground source systems are discussed

Land subsidence due to groundwater pumping and recharge: considering the particle-deposition effect in ground-source heat-pump engineering

Science.gov (United States)

Cui, Xianze; Liu, Quansheng; Zhang, Chengyuan; Huang, Yisheng; Fan, Yong; Wang, Hongxing

2018-01-01

With the rapid development and use of ground-source heat-pump (GSHP) systems in China, it has become imperative to research the effects of associated long-term pumping and recharge processes on ground deformation. During groundwater GSHP operation, small particles can be transported and deposited, or they can become detached in the grain skeleton and undergo recombination, possibly causing a change in the ground structure and characteristics. This paper presents a mathematical ground-deformation model that considers particle transportation and deposition in porous media based on the geological characteristics of a dual-structure stratum in Wuhan, eastern China. Thermal effects were taken into consideration because the GSHP technology used involves a device that uses heat from a shallow layer of the ground. The results reveal that particle deposition during the long-term pumping and recharge process has had an impact on ground deformation that has significantly increased over time. In addition, there is a strong correlation between the deformation change (%) and the amount of particle deposition. The position of the maximum deformation change is also the location where most of the particles are deposited, with the deformation change being as high as 43.3%. The analyses also show that flow of groundwater can have an effect on the ground deformation process, but the effect is very weak.

Land subsidence due to groundwater pumping and recharge: considering the particle-deposition effect in ground-source heat-pump engineering

Science.gov (United States)

Cui, Xianze; Liu, Quansheng; Zhang, Chengyuan; Huang, Yisheng; Fan, Yong; Wang, Hongxing

2018-05-01

With the rapid development and use of ground-source heat-pump (GSHP) systems in China, it has become imperative to research the effects of associated long-term pumping and recharge processes on ground deformation. During groundwater GSHP operation, small particles can be transported and deposited, or they can become detached in the grain skeleton and undergo recombination, possibly causing a change in the ground structure and characteristics. This paper presents a mathematical ground-deformation model that considers particle transportation and deposition in porous media based on the geological characteristics of a dual-structure stratum in Wuhan, eastern China. Thermal effects were taken into consideration because the GSHP technology used involves a device that uses heat from a shallow layer of the ground. The results reveal that particle deposition during the long-term pumping and recharge process has had an impact on ground deformation that has significantly increased over time. In addition, there is a strong correlation between the deformation change (%) and the amount of particle deposition. The position of the maximum deformation change is also the location where most of the particles are deposited, with the deformation change being as high as 43.3%. The analyses also show that flow of groundwater can have an effect on the ground deformation process, but the effect is very weak.

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

International Nuclear Information System (INIS)

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

2016-01-01

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

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

International Nuclear Information System (INIS)

Hanova, J; Dowlatabadi, H

2007-01-01

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

Determination of Ground Heat Exchangers Temperature Field in Geothermal Heat Pumps

Science.gov (United States)

Zhurmilova, I.; Shtym, A.

2017-11-01

For the heating and cooling supply of buildings and constructions geothermal heat pumps using low-potential ground energy are applied by means of ground exchangers. The process of heat transfer in a system of ground exchangers is a phenomenon of complex heat transfer. The paper presents a mathematical modeling of heat exchange processes, the temperature fields are built which are necessary for the determination of the ground array that ensures an adequate supply of low potential energy excluding the freezing of soil around the pipes in the ground heat exchangers and guaranteeing a reliable operation of geothermal heat pumps.

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

Energy Technology Data Exchange (ETDEWEB)

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

1996-10-27

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

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

International Nuclear Information System (INIS)

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

2009-01-01

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

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

Directory of Open Access Journals (Sweden)

Xin Wen Zhang

2015-07-01

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

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

International Nuclear Information System (INIS)

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

2014-01-01

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

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

DEFF Research Database (Denmark)

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

2012-01-01

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

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

Directory of Open Access Journals (Sweden)

Xiang Gou

2016-12-01

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

Impact of global warming on performance of ground source heat pumps in US climate zones

International Nuclear Information System (INIS)

Shen, Pengyuan; Lukes, Jennifer R.

2015-01-01

Highlights: • Used morphing method to have downscaled hourly local weather data from GCM. • Selected representative cities in different climate zones in the US for case study on GSHP performance. • Used hourly building simulation tools (eQuest and TRNSYS) to project GSHP performance in future. • Analysis on GSHP performance in 2050 for both residential and office building in the US are conducted. - Abstract: Ground source heat pumps (GSHP) have attracted increasing attention because of their high energy efficiencies. The aim of this paper is to study the performance of (GSHP) in future climate conditions (2040–2069) by using projected future hourly weather data of selected representative cities in the US to estimate future ground temperature change. The projected hourly weather data and estimated ground temperatures are input to an hourly simulation tool (TRNSYS and eQuest for this research), which provides reliable coupling of GSHP system and building performance. The simulation results show that global warming will decrease the energy efficiency of GSHP in US residential buildings because a rise in inlet and outlet water temperature is predicted for GSHP systems during the cooling season and because buildings will become more cooling dominated in the future. For office buildings, although the cooling performance of GSHP will not drop significantly under future climate, the overall energy efficiency for the system will decrease due to the increasing energy consumption of the ground loop pump. In the future, considering the significant ground heat imbalance for GSHP operation, GSHP will become less competitive both economically and technically than it is now in the context of US climate zones

Horizontal ground coupled heat pump: Thermal-economic modeling and optimization

Energy Technology Data Exchange (ETDEWEB)

Sanaye, Sepehr; Niroomand, Behzad [Energy Systems Improvement Laboratory (ESIL), Department of Mechanical Engineering, Iran University of Science and Technology (IUST) (Iran)

2010-12-15

The modeling and optimizing processes of a Ground Coupled Heat Pump (GCHP) with closed Horizontal Ground Heat eXchanger (HGHX) are presented in this paper. After thermal modeling of GCHP including HGHX, the optimum design parameters of the system were estimated by minimizing a defined objective function (total of investment and operation costs) subject to a list of constraints. This procedure was performed applying Genetic Algorithm technique. For given heating/cooling loads and various climatic conditions, the optimum values of saturated temperature/pressure of condenser and evaporator as well as inlet and outlet temperatures of the water source in cooling and heating modes were predicted. Then, for our case study, the design parameters as well as the configuration of HGHX were obtained. Furthermore, the sensitivity analysis of change in the total annual cost of the system and optimum design parameters with the climatic conditions, cooling/heating capacity, and soil type were discussed. (author)

Horizontal ground coupled heat pump: Thermal-economic modeling and optimization

International Nuclear Information System (INIS)

Sanaye, Sepehr; Niroomand, Behzad

2010-01-01

The modeling and optimizing processes of a Ground Coupled Heat Pump (GCHP) with closed Horizontal Ground Heat eXchanger (HGHX) are presented in this paper. After thermal modeling of GCHP including HGHX, the optimum design parameters of the system were estimated by minimizing a defined objective function (total of investment and operation costs) subject to a list of constraints. This procedure was performed applying Genetic Algorithm technique. For given heating/cooling loads and various climatic conditions, the optimum values of saturated temperature/pressure of condenser and evaporator as well as inlet and outlet temperatures of the water source in cooling and heating modes were predicted. Then, for our case study, the design parameters as well as the configuration of HGHX were obtained. Furthermore, the sensitivity analysis of change in the total annual cost of the system and optimum design parameters with the climatic conditions, cooling/heating capacity, and soil type were discussed.

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

Energy Technology Data Exchange (ETDEWEB)

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

2008-07-01

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

Investigations and model validation of a ground-coupled heat pump for the combination with solar collectors

International Nuclear Information System (INIS)

Pärisch, Peter; Mercker, Oliver; Warmuth, Jonas; Tepe, Rainer; Bertram, Erik; Rockendorf, Gunter

2014-01-01

The operation of ground-coupled heat pumps in combination with solar collectors requires comprising knowledge of the heat pump behavior under non-standard conditions. Especially higher temperatures and varying flow rates in comparison to non-solar systems have to be taken into account. Furthermore the dynamic behavior becomes more important. At ISFH, steady-state and dynamic tests of a typical brine/water heat pump have been carried out in order to analyze its behavior under varying operation conditions. It has been shown, that rising source temperatures do only significantly increase the coefficient of performance (COP), if the source temperature is below 10–20 °C, depending on the temperature lift between source and sink. The flow rate, which has been varied both on the source and the sink side, only showed a minor influence on the exergetic efficiency. Additionally a heat pump model for TRNSYS has been validated under non-standard conditions. The results are assessed by means of TRNSYS simulations. -- Highlights: • A brine/water heat pump was tested under steady-state and transient conditions. • Decline of exergetic efficiency at low temperature lifts, no influence of flow rate. • Expected improvement by reciprocating compressor and electronic expansion valve for solar assisted heat source. • A TRNSYS black box model (YUM) was validated and a flow rate correction was proven • The start-up behavior is a very important parameter for system simulations

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).

Annual simulations of heat pump systems with vertical ground heat exchangers

Energy Technology Data Exchange (ETDEWEB)

Bernier, M.A.; Randriamiarinjatovo, D. [Ecole Polytechnique, Montreal, PQ (Canada). Dept. de Genie Mecanique

2001-06-01

The recent increased popularity in ground-coupled heat pump (GCHP) systems is due to their energy saving potential. However, in order for a GCHP to operate efficiently, they must be sized correctly. This paper presents a method to perform annual simulations of GCHP systems to optimize the length of the ground heat exchanger and provide annual energy consumption data. A computer program has been developed to simulate the building load, heat pump and the ground heat exchanger, the three most distinct parts of the system. The coupled governing equations of these three models are solved simultaneously until a converged solution is obtained at each time step. The simulations are performed using the Engineering Equation Solver (EES). This program has proven to be useful in balancing ground heat exchanger length against heat pump energy consumption.15 refs., 9 figs.

A model predictive framework of Ground Source Heat Pump coupled with Aquifer Thermal Energy Storage System in heating and cooling equipment of a building

NARCIS (Netherlands)

Rostampour Samarin, V.; Bloemendal, J.M.; Keviczky, T.

2017-01-01

This paper presents a complete model of a building heating and cooling equipment and a ground source heat pump (GSHP) coupled with an aquifer thermal energy storage (ATES) system. This model contains detailed
mathematical representations of building thermal dynamics, ATES system dynamics, heat

Ground source heat pump retrofit at North Bonneville, WA City Hall

Energy Technology Data Exchange (ETDEWEB)

Hughey, M. [Skamania Co. PUD No. 1, Carson, WA (United States)

1997-12-31

In 1995, the City of North Bonneville, WA installed a 10-ton Ground Source Heat Pump (GSHP) to replace the electric resistance furnace in its 4,000 square, foot City Hall. North Bonneville is 30 miles east of Portland, Oregon, at river level in the Columbia River Gorge. Funded jointly by the Bonneville Power Administration, the State of Washington and the City, this project has successfully reduced the heating cost of City Hall by nearly one-half while dramatically increasing comfort. It has become a commercial model in the Pacific Northwest for assessing values of commercial GSHP retrofits. This interim report compares estimated savings with actual experience for the first operating year. Projected savings were $1,500; actual savings were $1,390 prior to adjustment for extreme weather. Adjusted savings for Heating Year 1996 were $1,490, a 47 percent decrease. Maintenance savings (not itemized) were in addition to this amount. Monitoring continues in 1997.

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

Directory of Open Access Journals (Sweden)

Pavel Neuberger

2017-11-01

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

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

Directory of Open Access Journals (Sweden)

Alexandros Sotirios Anifantis

2016-09-01

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

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

International Nuclear Information System (INIS)

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

2013-01-01

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

Numerical and experimental analysis of a horizontal ground-coupled heat pump system

Energy Technology Data Exchange (ETDEWEB)

Esen, Hikmet; Esen, Mehmet [Department of Mechanical Education, Faculty of Technical Education, University of Firat, 23119 Elazig (Turkey); Inalli, Mustafa [Department of Mechanical Engineering, Faculty of Engineering, University of Firat, 23119 Elazig (Turkey)

2007-03-15

The main objective of this work is to evaluate a heat pump system using the ground as a source of heat. A ground-coupled heat pump (GCHP) system has been installed and tested at the test room, University of Firat, Elazig, Turkey. Results obtained during experimental testing are presented and discussed here. The coefficient of performance (COP{sub sys}) of the GCHP system is determined from the measured data. A numerical model of heat transfer in the ground was developed for determining the temperature distribution in the vicinity of the pipe. The finite difference approximation is used for numerical analysis. It is observed that the numerical results agree with the experimental results. (author) (author)

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

Directory of Open Access Journals (Sweden)

Zi-ping Zhang

2013-01-01

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

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

International Nuclear Information System (INIS)

Ciavaglia, L.

2005-01-01

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

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

DEFF Research Database (Denmark)

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

2012-01-01

An important challenge for energy systems today is reducing dependency on fossil fuels, while handling increasing penetration levels of intermittent renewables such as wind and solar power. The efficient consumption of energy is a vital mater for a sustainable energy system. A significant part...... of energy is used for space heating, space cooling, and domestic hot water production which are provided to residential and commercial buildings. Air source heat pumps (ASHP) are widely used conversion technologies all over the world for providing building thermal energy services as: cooling, heating......, and water heating. ASHP does not have a constant temperature for the primary source like: soil, ground water, or surface water heat pumps but still have a majority in usage. As result, laboratory experiments and tests are faced by the problem of having to handle a wide range of conditions under which...

IMPACT OF GEOTHERMAL GRADIENT ON GROUND SOURCE HEAT PUMP SYSTEM MODELING

Directory of Open Access Journals (Sweden)

Tomislav Kurevija

2014-07-01

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

Development of a nonazeotropic heat pump for crew hygiene water heating

Science.gov (United States)

Walker, David H.; Deming, Glenn I.

1991-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2016-12-01

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

Overview of ground coupled heat pump research and technology transfer activities

Science.gov (United States)

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

Highlights of DOE-sponsored ground coupled heat pump (GCHP) research at Oak Ridge National Laboratory (ORNL) are presented. ORNL, in cooperation with Niagara Mohawk Power Company, Climate Master, Inc., and Brookhaven National Laboratory developed and demonstrated an advanced GCHP design concept with shorter ground coils that can reduce installed costs for northern climates. In these areas it can also enhance the competitiveness of GCHP systems versus air-source heat pumps by lowering their payback from 6 to 7 years to 3 to 5 years. Ground coil heat exchanger models (based primarily on first principles) have been developed and used by others to generate less conservative ground coil sizing methods. An aggressive technology transfer initiative was undertaken to publicize results of this research and make it available to the industry. Included in this effort were an international workshop, trade press releases and articles, and participation in a live teleconference on GCHP technology.

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

Directory of Open Access Journals (Sweden)

Chiemi Iba

2018-04-01

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

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

Directory of Open Access Journals (Sweden)

Nyers Jozsef

2017-01-01

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

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

International Nuclear Information System (INIS)

Johnson, Eric P.

2011-01-01

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

Characterization of the effects of borehole configuration and interference with long term ground temperature modelling of ground source heat pumps

International Nuclear Information System (INIS)

Law, Ying Lam E.; Dworkin, Seth B.

2016-01-01

Highlights: • Long term ground temperature response is explored using finite element methods. • Simulation method is validated against experimental and analytical data. • Temperature changes at a fast rate in the first few years and slows down gradually. • ASHRAE recommended separation distances are not always sufficient. • Thermal accumulation occurs at the centre of borehole field. - Abstract: Ground source heat pumps (GSHPs) are an environmentally friendly alternative to conventional heating and cooling systems because of their high efficiency and low greenhouse gas emissions. The ground acts as a heat sink/source for the excess/required heat inside a building for cooling and heating modes, respectively. However, imbalance in heating and cooling needs can change ground temperature over the operating duration. This increase/decrease in ground temperature lowers system efficiency and causes the ground to foul—failing to accept or provide more heat. In order to ensure that GSHPs can operate to their designed conditions, thermal modelling is required to simulate the ground temperature during system operation. In addition, the borehole field layout can have a major impact on ground temperature. In this study, four buildings were studied—a hospital, fast-food restaurant, residence, and school, each with varying borehole configurations. Boreholes were modelled in a soil volume using finite-element methods and heating and cooling fluxes were applied to the borehole walls to simulate the GSHP operation. 20 years of operation were modelled for each building for 2 × 2, 4 × 4, and 2 × 8 borehole configurations. Results indicate that the borehole separation distance of 6 m, recommended by ASHRAE, is not always sufficient to prevent borehole thermal interactions. Benefits of using a 2 × 8 configuration as opposed to a 4 × 4 configuration, which can be observed because of the larger perimeter it provides for heat to dissipate to surrounding soil were

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

International Nuclear Information System (INIS)

Lund, Rasmus; Persson, Urban

2016-01-01

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

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

Science.gov (United States)

Dimera, Nikoletta

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

Heating and cooling with ground-loop heat pumps; Heizen und Kuehlen mit erdgekoppelten Waermepumpen

Energy Technology Data Exchange (ETDEWEB)

Afjei, Th.; Dott, R. [Institut Energie am Bau, Fachhochschule Nordwestschweiz (FHNW), Muttenz (Switzerland); Huber, A. [Huber Energietechnik AG, Zuerich (Switzerland)

2007-08-15

This final report for the Swiss Federal Office of Energy (SFOE) presents the results of the SFOE-project 'Heating and cooling with ground coupled heat pumps' in which the benefits and costs of a heat pump heating and cooling system with a borehole heat exchanger were examined. In particular the dimensioning of the hydraulic system, control concept and user behaviour are dealt with. The results of the simulations of thermal building behaviour with MATLAB/SIMULINK, CARNOT, and EWS are discussed. The results of parameter studies carried out, including varying shading, cooling characteristic curves, temperature differences in the heat exchanger and the dead time between heating and cooling mode are discussed. These showed that a simple system with heat pump and borehole heat exchanger for heating or preparation of domestic hot water as well as for passive cooling proved to be the best choice.

Ground-Source Heat Pumps. Overview of Market Status, Barriers to Adoption, and Options for Overcoming Barriers

Energy Technology Data Exchange (ETDEWEB)

Goetzler, William [Navigant Consulting, Inc., Chicago, IL (United States); Zogg, Robert [Navigant Consulting, Inc., Chicago, IL (United States); Lisle, Heather [Navigant Consulting, Inc., Chicago, IL (United States); Burgos, Javier [Navigant Consulting, Inc., Chicago, IL (United States)

2009-02-03

February 2009 final report submitted to DOE by Navigant Consulting, Inc. This report summarizes the status of ground-source heat pump (GSHP) technology and market penetration globally, estimates the energy saving potential of GSHPs in the U.S., identifies key market barriers that are inhibiting wider market adoption of GSHPs, and recommends initiatives that can be implemented or facilitated by the DOE to accelerate market adoption.

Air source integrated heat pump simulation model for EnergyPlus

Energy Technology Data Exchange (ETDEWEB)

Shen, Bo; New, Joshua; Baxter, Van

2017-12-01

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

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

DEFF Research Database (Denmark)

Dannemand, Mark; Furbo, Simon; Perers, Bengt

2017-01-01

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

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

Directory of Open Access Journals (Sweden)

Yuguo Wu

2018-09-01

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

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

Science.gov (United States)

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

2017-12-01

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

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 analysis of direct-expansion ground-coupled heat pump systems

Science.gov (United States)

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

1991-09-01

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

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

Directory of Open Access Journals (Sweden)

Piljae Im

2018-01-01

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

Experimental studies on a ground coupled heat pump with solar thermal collectors for space heating

International Nuclear Information System (INIS)

Xi, Chen; Hongxing, Yang; Lin, Lu; Jinggang, Wang; Wei, Liu

2011-01-01

This paper presents experimental studies on a solar-assisted ground coupled heat pump (SAGCHP) system for space heating. The system was installed at the Hebei Academy of Sciences in Shijiazhuang (lat. N38 o 03', long. E114 o 26'), China. Solar collectors are in series connection with the borehole array through plate heat exchangers. Four operation modes of the system were investigated throughout the coldest period in winter (Dec 5th to Dec 27th). The heat pump performance, borehole temperature distributions and solar colleting characteristics of the SAGCHP system are analyzed and compared when the system worked in continuous or intermittent modes with or without solar-assisted heating. The SAGCHP system is proved to perform space heating with high energy efficiency and satisfactory solar fraction, which is a promising substitute for the conventional heating systems. It is also recommended to use the collected solar thermal energy as an alternative source for the heat pump instead of recharging boreholes for heat storage because of the enormous heat capacity of the earth. -- Highlights: → We study four working modes of a solar-assisted ground coupled heat pump. → The heating performance is in direct relation with the borehole temperature. → Solar-assisted heating elevates borehole temperature and system performance. → The system shows higher efficiency over traditional heating systems in cold areas. → Solar heat is not suggested for high temperature seasonal storage.

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

Energy Technology Data Exchange (ETDEWEB)

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

2012-11-30

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

Vertical-borehole ground-coupled heat pumps: A review of models and systems

Energy Technology Data Exchange (ETDEWEB)

Yang, H.; Cui, P. [Renewable Energy Research Group, Department of Building Services Engineering, The Hong Kong Polytechnic University, Hong Kong (China); Fang, Z. [Ground Source Heat Pump Research Center, Shandong Jianzhu University, Jinan (China)

2010-01-15

A large number of ground-coupled heat pump (GCHP) systems have been used in residential and commercial buildings throughout the world due to the attractive advantages of high efficiency and environmental friendliness. This paper gives a detailed literature review of the research and developments of the vertical-borehole GCHP technology for applications in air-conditioning. A general introduction on the ground source heat pump system and its development is briefly presented first. Then, the most typical simulation models of the vertical ground heat exchangers currently available are summarized in detail including the heat transfer processes outside and inside the boreholes. The various design/simulation programs for vertical GCHP systems primarily based on the typical simulation models are also reviewed in this paper. Finally, the various hybrid GCHP systems for cooling or heating-dominated buildings are well described. It is found that the GCHP technology can be used both in cold and hot weather areas and the energy saving potential is significant. (author)

The influence of heat sink temperature on the seasonal efficiency of shallow geothermal heat pumps

Science.gov (United States)

Pełka, Grzegorz; Luboń, Wojciech; Sowiżdżał, Anna; Malik, Daniel

2017-11-01

Geothermal heat pumps, also known as ground source heat pumps (GSHP), are the most efficient heating and cooling technology utilized nowadays. In the AGH-UST Educational and Research Laboratory of Renewable Energy Sources and Energy Saving in Miękinia, shallow geothermal heat is utilized for heating. In the article, the seasonal efficiency of two geothermal heat pump systems are described during the 2014/2015 heating season, defined as the period between 1st October 2014 and 30th April 2015. The first system has 10.9 kW heating capacity (according to European Standard EN 14511 B0W35) and extracts heat from three vertical geothermal loops at a depth of 80m each. During the heating season, tests warmed up the buffer to 40°C. The second system has a 17.03 kW heating capacity and extracts heat from three vertical geothermal loops at a depth of 100 m each, and the temperature of the buffer was 50°C. During the entire heating season, the water temperatures of the buffers was constant. Seasonal performance factors were calculated, defined as the quotient of heat delivered by a heat pump to the system and the sum of electricity consumed by the compressor, source pump, sink pump and controller of heat pumps. The measurements and calculations give the following results: - The first system was supplied with 13 857 kWh/a of heat and consumed 3 388 kWh/a electricity. The SPF was 4.09 and the average temperature of outlet water from heat pump was 40.8°C, and the average temperature of brine flows into the evaporator was 3.7 °C; - The second system was supplied with 12 545 kWh/a of heat and consumed 3 874 kWh/a electricity. The SPF was 3.24 and the average temperature of outlet water from heat pump was 51.6°C, and the average temperature of brine flows into the evaporator was 5.3°C. To summarize, the data shown above presents the real SPF of the two systems. It will be significant in helping to predict the SPF of objects which will be equipped with ground source heat pumps.

Electrical and engine driven heat pumps for effective utilisation of renewable energy resources

Energy Technology Data Exchange (ETDEWEB)

Aye, Lu; Charters, W.W.S

2003-07-01

Much of the energy used for domestic, commercial and industrial purposes is to provide efficient and effective heating of conditioned spaces and for specialist niche applications in process heat systems. Vapour compression heat pumps driven by electric motors or engines provide the real capability of upgrading low temperature sources of ambient and waste heat to match the desired load temperatures in such heating applications. Major source of ambient heat stem from the storage of solar energy in the ground, in lakes and rivers, and in atmospheric air. Heat pumps can therefore be used to effectively harness indirectly the daily solar radiation input. In addition many industries have major sources of waste low grade heat in the form of air or water discharged from the industrial process heat stream. Heat pumps are generally formally classified therefore as air source, ground source or water source units although there has also been considerable interest recently in hybrid units combining the attributes of two or more of these specific types mentioned above.

Electrical and engine driven heat pumps for effective utilisation of renewable energy resources

Energy Technology Data Exchange (ETDEWEB)

Lu Aye [Melbourne Univ., Dept. of Civil and Environmental Engineering, Parkville, VIC (Australia); Charters, W.W.S. [Melbourne Univ., Dept. of Mechanical and Manufacturing Engineering, Parkville, VIC (Australia)

2003-07-01

Much of the energy used for domestic, commercial and industrial purposes is to provide efficient and effective heating of conditioned spaces and for specialist niche applications in process heat systems. Vapour compression heat pumps driven by electric motors or engines provide the real capability of upgrading low temperature sources of ambient and waste heat to match the desired load temperatures in such heating applications. Major source of ambient heat stem from the storage of solar energy in the ground, in lakes and rivers, and in atmospheric air. Heat pumps can therefore be used to effectively harness indirectly the daily solar radiation input. In addition many industries have major sources of waste low grade heat in the form of air or water discharged from the industrial process heat stream. Heat pumps are generally formally classified therefore as air source, ground source or water source units although there has also been considerable interest recently in hybrid units combining the attributes of two or more of these specific types mentioned above. (Author)

Analysis & Tools to Spur Increased Deployment of “Waste Heat” Rejection/Recycling Hybrid Ground-source Heat Pump Systems in Hot, Arid or Semiarid Climates Like Texas

Energy Technology Data Exchange (ETDEWEB)

Masada, Glenn [Univ. of Texas, Austin, TX (United States); Moon, Tess [Univ. of Texas, Austin, TX (United States)

2013-09-01

This project team analyzed supplemental heat rejection/recovery (SHR) devices or systems that could be used in hybrid ground source heat pump (HGHP) systems located in arid or semi-arid regions in southwestern U.S. Identification of effective SHR solutions would enhance the deployment of ground source heat pumps (GHP) in these regions. In a parallel effort, the team developed integrated GHP models that coupled the building load, heat pump, and ground loop subsystems and which could be applied to residential and commercial office buildings. Then GHP and HGHP performances could be compared in terms of operational performance and life-cycle costs. Several potential SHR devices were analyzed by applying two strategies: 1) to remove heat directly from the water in the ground loop before it enters the ground and 2) to remove heat in the refrigerant loop of the vapor compression cycle (VCC) of the heat pump so less heat is transferred to the water loop at the condenser of the VCC. Cooling towers, adsorption coolers, and thermoelectric liquid coolers were included in strategy 1, and expanded desuperheaters, thermosyphons, and an optimized VCC were included in strategy 2. Of all SHR devices analyzed, only the cooling tower provided a cost-effective performance enhancement. For the integrated GHP model, the project team selected the building load model HAMBASE and its powerful computational Simulink/MatLab platform, empirical performance map models of the heat pumps based upon manufacturers’ performance data, and a ground loop model developed by Oklahoma State University and rewritten for this project in Simulink/MatLab. The design process used GLHEPRO, also from Oklahoma State University, to size the borehole fields. The building load and ground loop models were compared with simulations from eQuest, ASHRAE 140-2008 standards, EnergyPlus, and GLHEPRO and were found to predict those subsystems’ performance well. The integrated GHP model was applied to a 195m²

Norwegian participation in IEA Heat Pump Programme Annex 29 - final report

International Nuclear Information System (INIS)

Stene, Joern

2006-06-01

Ground source heat is a collective name for tapping, recharging and storing thermal energy at moderate temperature in the bedrock, ground water and soil (renewable energy). By means of heat pumps, ground source heating systems can be used as highly energy efficient and environmentally-friendly heating and cooling in all kinds of buildings. IEA's heat pump programme (IEA HPP) has in the period March 2004 to June 2006 carried out an Annex on heating pump systems based on ground source heat: 'Annex 29 - Ground-source heat pumps overcoming market and technical barriers'. The project has i.a. covered the development of more cost- and energy efficient solutions, identification and analysis of market obstacles, technology transfer and the task of making visible the energy economising potential and environmental gains that this type of systems represent. The six participating countries have been Canada, Japan, Norway, Sweden, USA and Austria (operating agent). Norway's participation in IEA Annex 29 has been financed by ENOVA SF, while SINTEF Energy research AS has been in charge of planning and executing the Norwegian project activities. This report provides a general presentation of ground source heat pump systems, and gives a summary of the most important Norwegian activities in IEA Annex 29, which includes: The development of a Norwegian internet home page (http://www.energy.sintef.no/prosjekt/annex29), preparation of Norwegian status report, initiation, coordination and carrying out of Norwegian research projects and reports, communication of results (technology transfer) in Norway, networking activities towards important market actors in Norway, participation and delivering discourse at international seminars (workshops), and participation at international working sessions (ml)

A strategy for improving pump and treat ground water remediation

International Nuclear Information System (INIS)

Hoffman, F.

1992-07-01

Established pump and treat ground water remediation has a reputation for being too expensive and time consuming, especially when cleanup standards are set at very low levels, e.g., 50 ft below ground surface) widespread ground water contamination. The perceived shortcomings of pump and treat result from the (1) tendency of most contaminants to sorb to formation materials, thus retarding contaminant removal; (2) geologic complexity, which requires detailed characterization for the design of optimal extraction systems within available resources; and (3) failure to apply dynamic well field management techniques. An alternative strategy for improving pump and treat ground water remediation consists of (1) detailed characterization of the geology, hydrology, and chemistry; (2) use of computer-aided data interpretation, data display, and decision support systems; (3) removal of sources, if possible; (4) initial design for plume containment and source remediation; (5) phased installation of the well field; (6) detailed monitoring of the remediation; (7) active ongoing re-evaluation of the operating well field, including redesign as appropriate (dynamic management); (8) re-injection of treated ground water to speed the flushing of contaminants; and (9) setting of appropriate cleanup levels or goals. Use of some or all of these techniques can dramatically reduce the time required to achieve cleanup goals and thus the cost of ground water remediation

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

Energy Technology Data Exchange (ETDEWEB)

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

2008-07-01

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

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

Directory of Open Access Journals (Sweden)

Moore Andrew D.

2017-01-01

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

Technical and economic working domains of industrial heat pumps: Part 2 - ammonia-water hybrid absorption-compression heat pumps

DEFF Research Database (Denmark)

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

2015-01-01

The ammonia-water hybrid absorption-compression heat pump (HACHP) has been proposed as a relevant technology for industrial heat supply, especially for high sink temperatures and high temperature glides in the sink and source. This is due to the reduced vapour pressure and the non-isothermal phase...... change of the zeotropic mixture, ammonia-water. To evaluate to which extent these advantages can be translated into feasible heat pump solutions, the working domain of the HACHP is investigated based on technical and economic constraints. The HACHP working domain is compared to that of the best available...... vapour compression heat pump with natural working fluids. This shows that the HACHP increases the temperature lifts and heat supply temperatures that are feasible to produce with a heat pump. The HACHP is shown to be capable of delivering heat supply temperatures as high as 150 °C and temperature lifts...

Technical and Economic Working Domains of Industrial Heat Pumps: Part 2 - Ammonia-Water Hybrid Absorption-Compression Heat Pumps

DEFF Research Database (Denmark)

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

2014-01-01

The ammonia-water hybrid absorption-compression heat pump (HACHP) is a relevant technology for industrial heat supply, especially for high sink temperatures and high temperature glides in the sink and source. This is due to the reduced vapour pressure and the non-isothermal phase change...... of the zeotropic mixture, ammonia-water. To evaluate to which extent these advantages can be translated into feasible heat pump solutions, the working domain of the HACHP is investigated based on technical and economic constraints. The HACHP working domain is compared to that of the best possible vapour...... compression heat pump with natural working fluids. This shows that the HACHP increases the temperature lifts and heat supply temperatures that are feasible to produce with a heat pump. The HACHP is shown to be capable of delivering heat supply temperatures as high as 140 XC and temperature lifts up to 60 K...

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

DEFF Research Database (Denmark)

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

2016-01-01

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

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

International Nuclear Information System (INIS)

Ozgener, Onder; Hepbasli, Arif

2005-01-01

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

Energy and exergy analysis of a ground-coupled heat pump system with two horizontal ground heat exchangers

Energy Technology Data Exchange (ETDEWEB)

Esen, Hikmet; Esen, Mehmet [Department of Mechanical Education, Faculty of Technical Education, Firat University, 23119 Elazig (Turkey); Inalli, Mustafa; Pihtili, Kazim [Department of Mechanical Engineering, Faculty of Engineering, Firat University, 23119 Elazig (Turkey)

2007-10-15

In this paper we investigate of energetic and exergetic efficiencies of ground-coupled heat pump (GCHP) system as a function of depth trenches for heating season. The horizontal ground heat exchangers (HGHEs) were used and it were buried with in 1 m (HGHE1) and 2 m (HGHE2) depth trenches. The energy efficiency of GCHP systems are obtained to 2.5 and 2.8, respectively, while the exergetic efficiencies of the overall system are found to be 53.1% and 56.3%, respectively, for HGHE1 and HGHE2. The irreversibility of HGHE2 is less than of the HGHE1 as about 2.0%. The results show that the energetic and exergetic efficiencies of the system increase when increasing the heat source (ground) temperature for heating season. And the end of this study, we deal with the effects of varying reference environment temperature on the exergy efficiencies of HGHE1 and HGHE2. The results show that increasing reference environment temperature decreases the exergy efficiency in both HGHE1 and HGHE2. (author)

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

DEFF Research Database (Denmark)

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

2017-01-01

This paper presents a theoretical study on the optimal usage of different low temperature heat sources to supply district heating by heat pumps. The study is based on data for the Copenhagen region. The heat sources were prioritized based on the coefficient of performance calculated for each hour...... and the covered demand of each heat source as well as required peak unit capacity. The results showed that heat pumps using different heat sources yield better performance than a heat pump based on a single one. The performance was influenced by the composition of the different heat sources. It was found that 78......% groundwater, 22% seawater and 0% air resulted in highest COP of 3.33 for the given heat demand. Furthermore, the implementation of rule based short term storage made peak units redundant. The variation in base load capacity showed that heat pumps utilizing the analyzed heat sources could perform very...

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

Energy Technology Data Exchange (ETDEWEB)

Roberson, B.F.

1988-07-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2010-07-01

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

Numerical analysis of a magnetocaloric heat pump implementation into a residential building

DEFF Research Database (Denmark)

Johra, Hicham

of the magneto-caloric heat pump in a single hydronic loop coupling directly the heat source and the heat sink without additional heat exchangers. Moreover, several parameters can be controlled in order to perform efficient part load power generation. The objective of this work is to understand how to integrate...... a magneto-caloric heat pump into a residential building and establish a control strategy for such device. A numerical model of a single family house with water based under-floor heating and horizontal ground source heat exchanger is created. It is used to demonstrate the feasibility and the advantages...... of the integrated magneto-caloric heat pump system is compared with conventional heat pumps one....

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.

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

Science.gov (United States)

Januševičius, Karolis; Streckienė, Giedrė

2013-12-01

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

太阳能-土壤源热泵复合系统优化与性能分析%System Optimization and Performance Analysis of Solar Energy and Ground-source Heat Pump Hybrid System

Institute of Scientific and Technical Information of China (English)

丁力勤

2016-01-01

本文利用瞬时系统模拟软件（Trnsys）搭建了常规土壤源热泵系统及太阳能-土壤源热泵并联复合式系统的模型，并根据不同集热器单位面积流量和水箱体积等参数进行了模拟计算。结果表明，土壤源热泵系统性能系数达3.6~3.8，具有明显的节能优势。%The models of ground-source heat pump system and the solar energy and ground-source heat pump shunt-wound hybrid system have been built by transient system (Trnsys) simulation software, and the simulation calculation has been processed according to the flow rate per unit area and water tank volume for different collectors. According to the simulation results, the coefficient of performance of the ground-source heat pump system is 3.6~3.8, and the system has advantages on energy saving.

Gas-driven pump for ground-water samples

Science.gov (United States)

Signor, Donald C.

1978-01-01

Observation wells installed for artificial-recharge research and other wells used in different ground-water programs are frequently cased with small-diameter steel pipe. To obtain samples from these small-diameter wells in order to monitor water quality, and to calibrate solute-transport models, a small-diameter pump with unique operating characteristics is required that causes a minimum alternation of samples during field sampling. A small-diameter gas-driven pump was designed and built to obtain water samples from wells of two-inch diameter or larger. The pump is a double-piston type with the following characteristics: (1) The water sample is isolated from the operating gas, (2) no source of electricity is ncessary, (3) operation is continuous, (4) use of compressed gas is efficient, and (5) operation is reliable over extended periods of time. Principles of operation, actual operation techniques, gas-use analyses and operating experience are described. Complete working drawings and a component list are included. Recent modifications and pump construction for high-pressure applications also are described. (Woodard-USGS)

Geothermal(Ground-Source)Heat Pumps: Market Status, Barriers to Adoption, and Actions to Overcome Barriers

Energy Technology Data Exchange (ETDEWEB)

Hughes, Patrick [ORNL

2008-12-01

More effective stewardship of our resources contributes to the security, environmental sustainability, and economic well-being of the nation. Buildings present one of the best opportunities to economically reduce energy consumption and limit greenhouse gas emissions. Geothermal heat pumps (GHPs), sometimes called ground-source heat pumps, have been proven capable of producing large reductions in energy use and peak demand in buildings. However, GHPs have received little attention at the policy level as an important component of a national strategy. Have policymakers mistakenly overlooked GHPs, or are GHPs simply unable to make a major contribution to the national goals for various reasons? This brief study was undertaken at DOE's request to address this conundrum. The scope of the study includes determining the status of global GHP markets and the status of the GHP industry and technology in the United States, assembling previous estimates of GHP energy savings potential, identifying key barriers to application of GHPs, and identifying actions that could accelerate market adoption of GHPs. The findings are documented in this report along with conclusions and recommendations.

Dual source heat pump

Science.gov (United States)

Ecker, Amir L.; Pietsch, Joseph A.

1982-01-01

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

Heat sources for heat pumps in the energetic and economic comparison

International Nuclear Information System (INIS)

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

2016-01-01

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

Temperature distributions in pavement and bridge slabs heated by using vertical ground-source heat pump systems - doi: 10.4025/actascitechnol.v35i4.15712

Directory of Open Access Journals (Sweden)

Asım Balbay

2013-10-01

Full Text Available Temperature distribution which occurs in pavement and bridge slabs heated for de-icing and snow melting during cold periods is determined by using vertical ground-source heat pump (GSHP systems with U-tube ground heat exchanger (GHE. The bridge and pavement models (slabs for de-icing and snow melting were constructed. A three-dimensional finite element model (FEM was developed to simulate temperature distribution of bridge slab (BS and pavement slab (PS. The temperature distribution simulations of PS and BS were conducted numerically by computational fluid dynamics (CFD program named ‘Fluent’. Congruence between the simulations and experimental data was determined.   

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

International Nuclear Information System (INIS)

Yu, Qi Dong

2017-01-01

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

Solar collectors and heat pump: Market review and preliminary simulation results

International Nuclear Information System (INIS)

Tepe, Rainer; Roennelid, Mats

2002-01-01

Heating systems that combine solar collectors and a heat pump available on the market in Sweden have been studied. A majority of the systems found combine the solar collectors with a ground source heat pump. The technology for combining the collectors and the heat pump does however vary considerably. In the most simple systems, the collectors heat the return water from the heat pump, i.e. the collectors are used for raising the temperature in the boreholes for the heat pump. In the advanced systems, the solar heat is used for tap water, space heating and for raising the temperature of the heat pump's evaporator. There exist only very few comparative evaluations of the contributions from solar collectors in heat pump systems, and there is a need for finding the potential for this technique. In the present study, results are reported from preliminary simulations of solar collectors and ground source heat pumps installed in one-family houses. Simulations are made for two heating loads: 8,650 and 16,500 kWh/year resp., and a hot water load of 3,000 kWh/year. The study shows that: the temperature of the borehole decreases when solar collectors are not used (about 1.2 deg C in three years): 8 m 2 glazed solar collectors used for hot water production can reduce the electricity consumption with up to 13%, with best results in the house with low heating load: 50 m 2 unglazed solar collectors coupled to the evaporator or the borehole can give reductions of up to 14%, largest reduction in the house with high heating load, where the heat extraction from the borehole is large: the unglazed collectors have the highest economic potential, and can be cost effective for houses with high heating load: the simulations do not include a thorough system optimization, better results can be expected from continued optimization work

Design aspects of commercial open-loop heat pump systems

Energy Technology Data Exchange (ETDEWEB)

Rafferty, Kevin

2000-01-01

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

Design Aspects of Commerical Open-Loop Heat Pump Systems

Energy Technology Data Exchange (ETDEWEB)

Rafferty, Kevin

2001-03-01

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

Study on hybrid ground-coupled heat pump systems

Energy Technology Data Exchange (ETDEWEB)

Yi, Man; Hongxing, Yang [Renewable Energy Research Group, The Hong Kong Polytechnic University, Hong Kong (China); Zhaohong, Fang [School of Thermal Energy Engineering, Shandong Architecture University, Jinan (China)

2008-07-01

Although ground-coupled heat pump (GCHP) systems are becoming attractive air-conditioning systems in some regions, the significant drawback for their wider application is the high initial cost. Besides, more energy is rejected into ground by the GCHP system installed in cooling-dominated buildings than the energy extracted from ground on an annual basis and this imbalance can result in the degradation of system performance. One of the available options that can resolve these problems is to apply the hybrid ground-coupled heat pump (HGCHP) systems, with supplemental heat rejecters for rejecting extra thermal energy when they are installed in cooling-dominated buildings. This paper presents a practical hourly simulation model of the HGCHP system by modeling the heat transfer of its main components. The computer program developed on this hourly simulation model can be used to calculate the operating data of the HGCHP system according to the building load. The design methods and running control strategies of the HGCHP system for a sample building are investigated. The simulation results show that proper HGCHP system can effectively reduce both the initial cost and the operating cost of an air-conditioning system compared with the traditional GCHP system used in cooling-dominated buildings. (author)

Exergy Analysis of a Ground-Coupled Heat Pump Heating System with Different Terminals

Directory of Open Access Journals (Sweden)

Xiao Chen

2015-04-01

Full Text Available In order to evaluate and improve the performance of a ground-coupled heat pump (GCHP heating system with radiant floors as terminals, an exergy analysis based on test results is performed in this study. The system is divided into four subsystems, and the exergy loss and exergy efficiency of each subsystem are calculated using the expressions derived based on exergy balance equations. The average values of the measured parameters are used for the exergy analysis. The analysis results show that the two largest exergy losses occur in the heat pump and terminals, with losses of 55.3% and 22.06%, respectively, and the lowest exergy efficiency occurs in the ground heat exchange system. Therefore, GCHP system designers should pay close attention to the selection of heat pumps and terminals, especially in the design of ground heat exchange systems. Compared with the scenario system in which fan coil units (FCUs are substituted for the radiant floors, the adoption of radiant floors can result in a decrease of 12% in heating load, an increase of 3.24% in exergy efficiency of terminals and an increase of 1.18% in total exergy efficiency of the system. The results may point out the direction and ways of optimizing GCHP systems.

太阳能—地源热泵联合循环技术研究%Study on Technologies of Solar Energy and Ground Source Heat Pump Combined Circulation

Institute of Scientific and Technical Information of China (English)

孙洲阳; 陈武

2011-01-01

太阳能—地源热泵系统联合循环的研究目前还没有形成完备的理论体系,可供应用的基础数据不足,还不能为工程实际应用提供充足的理论依据.本文就太阳能与地源热泵系统联合运行的必要性和可行性进行探讨,提出了相应的技术方案；总结太阳能—地源热泵空调系统的特性,提出太阳能—地源热泵空调系统有待解决的问题,为太阳能—地源热泵联合循环技术在建筑上应用提供参考和借鉴.%Theory system of solar energy combined with ground-source heat pump has not been mature, thereby lack basic data and theory thereunder for engineering application. Necessarity and feasibility of solar energy combined with ground-source heat pump is discussed, bring forward corresponding technique scheme. Character of solar energy combined with ground-source heat pump system is summarized, and bring forward await settle problems, provide reference for architecture application of solar energy combined with ground-source heat pump.

Air-Source Integrated Heat Pump System Development – Final Report

Energy Technology Data Exchange (ETDEWEB)

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

2017-07-01

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

Soil Thermal Balance Analysis for a Ground Source Heat Pump System in a Hot-Summer and Cold-Winter Region

Directory of Open Access Journals (Sweden)

Zhongchao Zhao

2018-05-01

Full Text Available As a renewable and high energy efficiency technology providing air conditioning and domestic hot water, the ground source heat pump system (GSHPS has been extensively used worldwide in recent years. Compared with conventional systems, GSHPSs with heat recovery reject less heat into the soil and extract more heat from it, which can help reduce soil thermal imbalance in hot-summer and cold-winter regions. In this paper, conventional GSHPS, and GSHPS with different heat recovery ratios, in a typical city were compared based on thermal imbalance ratios, average soil temperatures and soil temperature increases. The transient system simulation software was used to simulate the operation performance of GSHPS. The thermal imbalance ratio and soil temperature decreased with increasing heat recovery ratio. After 20 years of operation, the soil thermal imbalance ratios of the GSHPS were 29.2%, 21.1%, 16%, and 5.2%, and the soil temperature rises were 8.78 °C, 5.25 °C, 3.44 °C, and 0.34 °C, while the heat recovery ratios were 0, 18%, 30% and 53%, respectively. Consequently, a GSHPS with heat recovery is a potentially efficient and economical approach for buildings in hot-summer and cold-winter regions.

The efficiency of the heat pump water heater, during DHW tapping cycle

Directory of Open Access Journals (Sweden)

Gużda Arkadiusz

2017-01-01

Full Text Available This paper discusses one of the most effective systems for domestic hot water (DHW production based on air-source heat pump with an integrated tank. The operating principle of the heat pump is described in detail. Moreover, there is an account of experimental set-up and results of the measurements. In the experimental part, measurements were conducted with the aim of determining the energy parameters and measures of the economic efficiency related to the presented solution. The measurements that were conducted are based on the tapping cycle that is similar to the recommended one in EN-16147 standard. The efficiency of the air source heat pump during the duration of the experiment was 2.43. In the end of paper, authors conducted a simplified ecological analysis in order to determine the influence of operation of air-source heat pump with integrated tank on the environment. Moreover the compression with the different source of energy (gas boiler with closed combustion chamber and boiler fired by the coal was conducted. The heat pump is the ecological friendly source of the energy.

The efficiency of the heat pump water heater, during DHW tapping cycle

Science.gov (United States)

Gużda, Arkadiusz; Szmolke, Norbert

2017-10-01

This paper discusses one of the most effective systems for domestic hot water (DHW) production based on air-source heat pump with an integrated tank. The operating principle of the heat pump is described in detail. Moreover, there is an account of experimental set-up and results of the measurements. In the experimental part, measurements were conducted with the aim of determining the energy parameters and measures of the economic efficiency related to the presented solution. The measurements that were conducted are based on the tapping cycle that is similar to the recommended one in EN-16147 standard. The efficiency of the air source heat pump during the duration of the experiment was 2.43. In the end of paper, authors conducted a simplified ecological analysis in order to determine the influence of operation of air-source heat pump with integrated tank on the environment. Moreover the compression with the different source of energy (gas boiler with closed combustion chamber and boiler fired by the coal) was conducted. The heat pump is the ecological friendly source of the energy.

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

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.

The influence of a vertical ground heat exchanger length on the electricity consumption of the heat pumps

Energy Technology Data Exchange (ETDEWEB)

Michopoulos, A.; Kyriakis, N. [Process Equipment Design Laboratory, Mechanical Engineer Department, Aristotle University of Thessaloniki (AUTh), P.O. Box 487, 541 24 Thessaloniki (Greece)

2010-07-15

The use of heat pumps combined with vertical ground heat exchangers for heating and cooling of buildings, has significantly gained popularity in recent years. The design method for these systems, as it is proposed by ASHRAE, is taking into account the maximum thermal and cooling loads of the building, the thermophysical properties of the soil at the area of installation and a minimum Coefficient of Performance (COP) of the heat pumps. This approach usually results in larger than needed length of the ground heat exchanger, thus increasing the installation cost. A new analytical simulation tool, capable to determine the required ground heat exchanger length has been developed at the Process Equipment Design Laboratory (PEDL) of the AUTh. It models the function of the system as a whole over long time periods, e.g. 20 years, using as input parameters the thermal and cooling loads of the building, the thermophysical properties of the borehole and the characteristic curves of the heat pumps. The results include the electricity consumption of the heat pumps and the heat absorbed from or rejected to the ground. The aim of this paper is to describe the developed simulation algorithm and present the results of such a simulation in a case study. It is proved that the total required length of the ground heat exchanger is less than that calculated using the common numerical method. (author)

Comparison of LCA results of low temperature heat plant using electric heat pump, absorption heat pump and gas-fired boiler

International Nuclear Information System (INIS)

Nitkiewicz, Anna; Sekret, Robert

2014-01-01

Highlights: • Usage of geothermal heat pump can bring environmental benefits. • The lowest environmental impact for whole life cycle is obtained for absorption heat pump. • The value of heat pump COP has a significant influence on environmental impact. • In case of coal based power generation the damage to human health is significant. - Abstract: This study compares the life cycle impacts of three heating plant systems which differ in their source of energy and the type of system. The following heating systems are considered: electric water-water heat pump, absorption water-water heat pump and natural gas fired boiler. The heat source for heat pump systems is low temperature geothermal source with temperature below 20 °C and spontaneous outflow 24 m 3 /h. It is assumed that the heat pumps and boiler are working in monovalent system. The analysis was carried out for heat networks temperature characteristic at 50/40 °C which is changing with outdoor temperature during heating season. The environmental life cycle impact is evaluated within life cycle assessment methodological framework. The method used for life cycle assessment is eco-indicator ‘99. The functional unit is defined as heating plant system with given amount of heat to be delivered to meet local heat demand in assumed average season. The data describing heating plant system is derived from literature and energy analysis of these systems. The data describing the preceding life cycle phases: extraction of raw materials and fuels, production of heating devices and their transportation is taken from Ecoinvent 2.0 life cycle inventory database. The results were analyzed on three levels of indicators: single score indicator, damage category indicators and impact category indicator. The indicators were calculated for characterization, normalization and weighting phases as well. SimaPro 7.3.2 is the software used to model the systems’ life cycle. The study shows that heating plants using a low

Ground source heat pumps versus high efficiency natural gas furnaces in Alberta

Energy Technology Data Exchange (ETDEWEB)

Shaw, J.

2003-02-02

For the past twenty years or so, the heating and cooling of numerous buildings in northern Europe has been accomplished using ground source heat pumps (GSHPs), while in North America they have been in use for approximately ten years. In the Prairies, natural gas furnaces dominate, while GSHP are more popular in eastern Canada. The author noted that natural gas furnaces have an efficiency of 80 per cent or less, while high efficiency natural gas (HENG) furnaces, more expensive, have an efficiency in the 90 per cent range. A brief outline of the principles behind GSHPs was provided. The Coefficient of Performance (COP) of GSHP reaches up to 500 per cent depending whether the unit is cooling or heating. The amount of heat produced by a heating system expressed as a percentage of the energy input required to operate the system is the definition used for the efficiency. In those cases where it is possible to amortize the initial costs, pay now or obtain a subsidy, the installation of GSHP is advantageous. Several factors affect the total cost of heating a building, such as the airtightness of the building and its insulation, the coldness of the climate, and the inside controlled temperature setting. The author then examined the cost of operating a GSHP versus a natural gas furnace. In most examples studied, the cost of operating a GSHP was less than the cost of operating a natural gas furnace. The Total Equivalent Warming Impact (TEWI) of GSHPs and HENG furnaces was examined. The author concluded that the cost of heating by GSHP in Alberta will be lower than the cost of heating by HENG which requires a separate air conditioning unit for the summer months, with additional improvements in efficiency and insulation. 7 refs., 4 tabs.

Field Performance of Heat Pump Water Heaters in the Northeast

Energy Technology Data Exchange (ETDEWEB)

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

2016-02-01

Heat pump water heaters (HPWHs) are finally entering the mainstream residential water heater market. Potential catalysts are increased consumer demand for higher energy efficiency electric water heating and a new Federal water heating standard that effectively mandates use of HPWHs for electric storage water heaters with nominal capacities greater than 55 gallons. When compared to electric resistance water heating, the energy and cost savings potential of HPWHs is tremendous. Converting all electric resistance water heaters to HPWHs could save American consumers 7.8 billion dollars annually ($182 per household) in water heating operating costs and cut annual residential source energy consumption for water heating by 0.70 quads.

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

Institute of Scientific and Technical Information of China (English)

赵金秀

2015-01-01

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

Case Study for the ARRA-funded Ground Source Heat Pump (GSHP) Demonstration at Wilders Grove Solid Waste Service Center in Raleigh, NC

Energy Technology Data Exchange (ETDEWEB)

Liu, Xiaobing [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Malhotra, Mini [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Xiong, Zeyu [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

2017-11-01

High initial costs and lack of public awareness of ground-source heat pump (GSHP) technology are the two major barriers preventing rapid deployment of this energy-saving technology in the United States. Under the American Recovery and Reinvestment Act (ARRA), 26 GSHP projects have been competitively selected and carried out to demonstrate the benefits of GSHP systems and innovative technologies for cost reduction and/or performance improvement. This paper highlights the findings of a case study of one of the ARRA-funded GSHP demonstration projects, a distributed GSHP system for providing all the space conditioning, outdoor air ventilation, and 100% domestic hot water to the Wilders Grove Solid Waste Service Center of City of Raleigh, North Carolina. This case study is based on the analysis of measured performance data, construction costs, and simulations of the energy consumption of conventional central heating, ventilation, and air-conditioning (HVAC) systems providing the same level of space conditioning and outdoor air ventilation as the demonstrated GSHP system. The evaluated performance metrics include the energy efficiency of the heat pump equipment and the overall GSHP system, pumping performance, energy savings, carbon emission reductions, and cost-effectiveness of the GSHP system compared with conventional HVAC systems. This case study also identified opportunities for reducing uncertainties in the performance evaluation and improving the operational efficiency of the demonstrated GSHP system.

Ground water heat pumps and cooling with ground water basins as seasonal storage; Grundvandsvarmepumper og -koeling med grundvandsmagasiner som saesonlager

Energy Technology Data Exchange (ETDEWEB)

2008-04-15

Ground water temperature is constant all the year round, in Denmark approximately 9 deg. C, which is ideal for a number of cooling purposes including cooling of buildings. The structures in which the ground water flows (sand, gravel and chalk) are efficient for storing coldness and heat over longer periods. By using seasonal storage of low-temperature heat and coldness in ground water layers close to the terrain it is feasible to reach profitable energy savings of up to 90% for cooling and heating of e.g. hotels, airports, shopping malls, office buildings and other larger buildings. At the same time the large energy savings means major reduction of CO{sub 2} emissions. (BA)

Quantifying the energy impact of a variable flow pump in a ground-coupled heat pump system

Energy Technology Data Exchange (ETDEWEB)

Iolova, K.; Bernier, M.A. [Ecole Polytechnique, Montreal, PQ (Canada). Dept. de Genie Mecanique; Nichols, L. [Dessau-Soprin, Montreal, PQ (Canada)

2006-07-01

The thermal behaviour of an energy-efficient public high school building was modelled using the TRNSYS multi-zone building simulation program. The architectural elements such as windows, external and internal walls, roofs, and slabs were described in detail. The two-storey Ecole du Tournant high school near Montreal is the most efficient in Quebec and the second in Canada. It consumes 79.2 per cent less source energy than a typical high school built in accordance with the Model National Energy Code of Canada for Buildings. This presentation described the case study and quantified the energy impact of replacing a constant speed pump with a pump driven by a variable frequency drive in a ground-coupled heat pump (GCHP) system that was installed in the high school. Performance data collected from an on-site energy management system showed that the annual energy consumption of the heat pumps is 33 per cent (63700 kWh) of the total energy consumption of the school while the circulating pump consumes 7.1 per cent (13702 kWh). This performance data was used to validate the energy simulations which were performed using TRNSYS 15. Simulations with variable-flow pumping showed that pumping energy consumption was reduced by about 82 per cent while the total energy used by the circulating pump and heat pumps was reduced by 18.5 per cent. 11 refs., 2 tabs., 13 figs.

Groundwater heat pumps with turbines for the return water; Grundwasser-Waermepumpe mit Rueckgabe-Turbinierung

Energy Technology Data Exchange (ETDEWEB)

Eberhard, M.

2007-09-15

This final report for the Swiss Federal Office of Energy (SFOE) reports on improvements in the efficiency of a ground water heat pump installation in an office building. The water return well was equipped with a turbine. In this installation, the ground water is pumped up from a depth of 45 meters which means that a lot of electricity is needed for the pumping of the water. Coefficients of performance of the system are quoted for the situation with and without the turbine. The conversion of a pump for use as a turbine is commented on. The construction of a specially developed turbine with reduced electricity consumption is suggested. Seasonal performance data of the system is provided in tabular form.

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

NARCIS (Netherlands)

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

2015-01-01

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

Impact of Seasonal Heat Accumulation on Operation of Geothermal Heat Pump System with Vertical Ground Heat Exchanger

Science.gov (United States)

Timofeev, D. V.; Malyavina, E. G.

2017-11-01

The subject of the investigation was to find out the influence of heat pump operation in summer on its function in winter. For this purpose a mathematical model of a ground coupled heat pump system has been developed and programmed. The mathematical model of a system ground heat exchanger uses the finite difference method to describe the heat transfer in soil and the analytical method to specify the heat transfer in the U-tubes heat exchanger. The thermal diffusivity by the heat transfer in the soil changes during gradual freezing of the pore moisture and thus slows soil freezing. The mathematical model of a heat pump includes the description of a scroll compressor and the simplified descriptions of the evaporator and condenser. The analysis showed that heating during the cold season and cooling in the warm season affect the average heat transfer medium temperature in the soil loop in the winter season. It has been also showed that the degree of this effect depends on the clay content in the soil.

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

DEFF Research Database (Denmark)

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

2017-01-01

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

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

International Nuclear Information System (INIS)

Dawoud, Belal

2014-01-01

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

Technical Feasibility Study for Deployment of Ground-Source Heat Pump Systems: Portsmouth Naval Shipyard -- Kittery, Maine

Energy Technology Data Exchange (ETDEWEB)

Hillesheim, M.; Mosey, G.

2014-11-01

The U.S. Environmental Protection Agency (EPA) Office of Solid Waste and Emergency Response, in accordance with the RE-Powering America's Lands initiative, engaged the U.S. Department of Energy's (DOE) National Renewable Energy Laboratory (NREL) to conduct feasibility studies to assess the viability of developing renewable energy generating facilities on contaminated sites. Portsmouth Naval Shipyard (PNSY) is a United States Navy facility located on a series of conjoined islands in the Piscataqua River between Kittery, ME and Portsmouth, NH. EPA engaged NREL to conduct a study to determine technical feasibility of deploying ground-source heat pump systems to help PNSY achieve energy reduction goals.

Heat pumps barometer - EurObserv'ER 2016

International Nuclear Information System (INIS)

2016-01-01

The heat pump (HP) sector had an excellent year in 2015. Appliance sales taking all heating and cooling market technologies into account, increased by 20% from 2212898 units in 2014 to 2655331 units in 2015. The emerging trend over the past few years specific to the HP segment for water-borne systems is that air-source HPs are clearly gaining market shares to the detriment of the ground-source HP market, while reversible HPs using air as their vector are taking advantage of record temperatures that have given a boost to the cooling market

地源热泵与太阳能联合供热系统集热器面积优化的研究%Collector Area Optimization of Ground Source Heat Pump and Solar Combined Heating System

Institute of Scientific and Technical Information of China (English)

智超英; 赵宇含

2018-01-01

This paper mainly analyzes various influence factors on heat collector area of the ground source heat pump and solar combined heating system, studies the relationship of the cost of solar heat collection system,ground source heat pump operating costs per square meter,the maximum net benefit and solar collector area. In one run cycle,considering the maximum income,solar heating guarantee rate and ground source heat pump operating costs per square meter, the collector area of the combined heating system is optimized finally.%分析影响地源热泵与太阳能联合供热系统集热器面积的各种因素,研究太阳能集热系统造价、地源热泵每平方米运行费用、最大净受益、太阳能集热器面积相互间的关系.在一个循环周期内参考最大净收益,利用太阳能采暖保证率和地源热泵每平方米的运行费用的统计数据,最终联合供热系统的集热器面积达到最优.

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

International Nuclear Information System (INIS)

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

2008-01-01

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

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

International Nuclear Information System (INIS)

Lam, Joseph C.; Chan, Wilco W.

2003-01-01

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

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

International Nuclear Information System (INIS)

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

2016-01-01

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

Applicability Analysis of Solar Water Source Heat Pump for Building%太阳能水源热泵的建筑适用性研究

Institute of Scientific and Technical Information of China (English)

朱继宏; 李德英

2015-01-01

太阳能水源热泵系统是一种新型高效节能环保的系统，太阳能与热泵联合供暖可以发挥各自的优势，弥补单一形式的不足，提高采暖的稳定性和系统运行性能。针对我国太阳能水源热泵建筑适应性问题，以哈尔滨、北京、上海的气象数据库作为基础条件，分析了典型建筑热负荷特征，建立系统数学模型，并用 TRNSYS 平台进行优化求解，为适用性研究提供了必要的数据基础。依据寿命周期评价理论，对各地区太阳能水源热泵建筑适用性进行分析，结果表明严寒地区及寒冷地区太阳能水源热泵适用性较好，环境效益明显。%The solar water source heat pump system is an environmental friendly and high-efficient system. When solar heating system couples with water source heat pump, the two systems can complement each other, and improve the stability and performance of the heating system. Aiming at applicability of solar water source heat pump for building in our country, with meteorological database of Harbin, Beijing, Shanghai as basic conditions, the paper analyzes heat load characteristics of typical building. Mathematical model is established. Using TRNSYS platform for optimal solution, the article provides the necessary data basis for study on applicability of solar water source heat pump. According to the theory of life cycle assessment, the paper analyzes applicability of solar water source heat pump for building of each region. The result shows that the applicability of solar water source heat pump in severely cold region and cold region is environmentally beneficial.

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

Energy Technology Data Exchange (ETDEWEB)

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

2013-01-15

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

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

Hourly simulation of a Ground-Coupled Heat Pump system

Science.gov (United States)

Naldi, C.; Zanchini, E.

2017-01-01

In this paper, we present a MATLAB code for the hourly simulation of a whole Ground-Coupled Heat Pump (GCHP) system, based on the g-functions previously obtained by Zanchini and Lazzari. The code applies both to on-off heat pumps and to inverter-driven ones. It is employed to analyse the effects of the inverter and of the total length of the Borehole Heat Exchanger (BHE) field on the mean seasonal COP (SCOP) and on the mean seasonal EER (SEER) of a GCHP system designed for a residential house with 6 apartments in Bologna, North-Center Italy, with dominant heating loads. A BHE field with 3 in line boreholes is considered, with length of each BHE either 75 m or 105 m. The results show that the increase of the BHE length yields a SCOP enhancement of about 7%, while the SEER remains nearly unchanged. The replacement of the on-off heat pump by an inverter-driven one yields a SCOP enhancement of about 30% and a SEER enhancement of about 50%. The results demonstrate the importance of employing inverter-driven heat pumps for GCHP systems.

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

Energy Technology Data Exchange (ETDEWEB)

Stene, Joern

2004-02-01

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

Domestic heat pumps in the UK. User behaviour, satisfaction and performance

Energy Technology Data Exchange (ETDEWEB)

Caird, S.; Roy, R.; Potter, S. [Design Innovation Group, Dept. Design, Development, Environment and Materials, Faculty of Mathematics, Computing and Technology, The Open University, Milton Keynes, MK7 6AA (United Kingdom)

2012-08-15

Consumer adoption of microgeneration technologies is part of the UK strategy to reduce carbon emissions from buildings. Domestic heat pumps are viewed as a potentially important carbon saving technology, given the ongoing decarbonisation of the electricity supply system. To address the lack of independent evaluation of heat pump performance, the Energy Saving Trust undertook the UK's first large-scale heat pump field trial, which monitored 83 systems in real installations. As part of the trial, the Open University studied the consumers' experience of using a domestic heat pump. An in-depth user survey investigated the characteristics, behaviour, and satisfactions of private householders and social housing residents using ground source and air source heat pumps for space and/or water heating, and examined the influence of user-related factors on measured heat pump system efficiency. The surveys found that most users were satisfied with the reliability, heating, hot water, warmth and comfort provided by their system. Analysis of user characteristics showed that higher system efficiencies were associated with greater user understanding of their heat pump system, and more continuous heat pump operation, although larger samples are needed for robust statistical confirmation. The analysis also found that the more efficient systems in the sample were more frequently located in the private dwellings than at the social housing sites and this difference was significant. This is explained by the interaction between differences in the systems, dwellings and users at the private and social housing sites. The implications for heat pump research, practice and policy are discussed.

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

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

Science.gov (United States)

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

2017-01-12

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

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

International Nuclear Information System (INIS)

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

2015-01-01

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

Radon as a tracer to characterize the interactions between groundwater and surface water around the ground source heat pump system in riverside area

Science.gov (United States)

Kim, Jaeyeon; Lee, Seong-Sun; Lee, Kang-Kun

2016-04-01

The interaction characteristics between groundwater and surface water was examined by using Radon-222 at Han River Environmental Research Center (HRERC) in Korea where a geothermal resource using indirect open loop ground source heat pump (GSHP) has been developed. For designing a high efficiency performance of the open loop system in shallow aquifer, the riverside area was selected for great advantage of full capacity of well. From this reason groundwater properties of the study site can be easily influenced by influx of surrounding Han River. Therefore, 12 groundwater wells were used for monitoring radon concentration and groundwater level with fluctuation of river stage from May, 2014 to Apr., 2015. The short term monitoring data showed that the radon concentration was changed in accordance with flow meter data which was reflected well by the river stage fluctuation. The spatial distribution of radon concentration from long term monitoring data was also found to be affected by water level fluctuation by nearby dam activity and seasonal effect such as heavy rainfall and groundwater pumping. The estimated residence time indicates that river flows to the study site change its direction according to the combined effect of river stage and groundwater hydrology. In the linear regression of the values, flow velocities were yielded around 0.04 to 0.25 m/day which were similar to flow meter data. These results reveal that Radon-222 can be used as an appropriate environmental tracer in examining the characteristics of interaction in consideration of fluctuating river flow on operation of GSHP in the riverside area. ACKNOWLEDGEMENT This work was supported by the research project of "Advanced Technology for Groundwater Development and Application in Riversides (Geowater+) in "Water Resources Management Program (code 11 Technology Innovation C05)" of the MOLIT and the KAIA in Korea.

Geothermal heat pumps as one of possibilities of an alternative energy used for objects heating objects in Czech Republic

Directory of Open Access Journals (Sweden)

Jiří Ryška

2007-06-01

Full Text Available The use of geothermal energy for more localised energy requirements is becoming more apparent with the use of geothermal heat pumps. The use of heat from the upper portion of the earth's crust can be useful and efficient method of energy saving. At around 50 m below the earth's surface the ambient temperature fluctuates between around 8-12 oC. This heat can be used by being transferred to the surface via a loop system using a high-efficiency refrigerant type of material.These systems are also typically more efficient than gas or oil-fired heating systems. They are more energy efficient than air-source heat pumps because they draw heat from, or release heat to, the earth, which has moderate temperatures all the year, rather than to the air. Geothermal heat pumps use the relatively constant temperature of the ground or water several meters below the earth's surface as source of heating and cooling. Geothermal heat pumps are appropriate for retrofit or new homes, where both heating and cooling are desired. In addition to heating and cooling, geothermal heat pumps can provide domestic hot water. They can be used for virtually any home size or lot in any region of the Czech Republic.

Residential heat pumps in the future Danish energy system

DEFF Research Database (Denmark)

Petrovic, Stefan; Karlsson, Kenneth Bernard

2016-01-01

for politically agreed targets which include: at least 50% of electricity consumption from wind power starting from 2020, fossil fuel free heat and power sector from 2035 and 100% renewable energy system starting from 2050. Residential heat pumps supply around 25% of total residential heating demand after 2035......Denmark is striving towards 100% renewable energy system in 2050. Residential heat pumps are expected to be a part of that system.We propose two novel approaches to improve the representation of residential heat pumps: Coefficients of performance (COPs) are modelled as dependent on air and ground...... temperature while installation of ground-source heat pumps is constrained by available ground area. In this study, TIMES-DK model is utilised to test the effects of improved modelling of residential heat pumps on the Danish energy system until 2050.The analysis of the Danish energy system was done...

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

International Nuclear Information System (INIS)

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

2017-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

Juvonen, J.; Lapinlampi, T.

2013-08-15

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

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

Directory of Open Access Journals (Sweden)

Min Gyung Yu

2016-04-01

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

The impacts of groundwater heat pumps on urban shallow ...

African Journals Online (AJOL)

DR TONUKARI NYEROVWO

2011-07-25

Jul 25, 2011 ... In order to assess the impacts of groundwater heat pumps on urban shallow groundwater ... thermal transfer systems that use the ground water as a ... Abbreviations: GWHPs, Groundwater heat pumps; GHGs, ... Areas (Mm2).

Refrigerant charge management in a heat pump water heater

Science.gov (United States)

Chen, Jie; Hampton, Justin W.

2014-06-24

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

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

Science.gov (United States)

Song, Yulong; Ye, Zuliang; Cao, Feng

2017-08-01

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

Test and Analysis of Solar Energy-ground Source Heat Pump Complex Systems%太阳能-地源热泵复合系统的实验研究

Institute of Scientific and Technical Information of China (English)

侯静; 荆有印; 王静; 杨鹏

2012-01-01

The ground-source heat pump, a trend in the future, is a high efficiency system that uses the renewable geothermal. But in northern China, the heat load is the major way. In this, the heat that underground pipe absorbs in winter is more than the heat discharged by underground pipe in summer. After long-time running, the heat pump system will destroy the soil temperature field. This article describes a complex heat pump system of solar-ground source. And this article, through experiment, will prove that the solar assisted system can effectively restore soil temperature increase the coefficient of performance and achieve long-term stable operation of heat pump system.%地源热泵是利用可再生能源地热能的一种高效热泵系统，是未来发展的趋势。但在我国北方地区，大部分以热负荷为主，冬季地下埋管的取热量高于夏季的释热量，长期运行会破坏土壤温度场。介绍了太阳能一地源热泵复合系统，通过实验验证了太阳能辅助系统能够有效恢复土壤温度，提高系统性能系数，可以实现热泵长期稳定的运行。

Heat pumps as a tool for energy recovery from mining wastes

Energy Technology Data Exchange (ETDEWEB)

Banks, D.; Skarphagen, H.; Wiltshire, R.; Jessop, C. [Holymoor Consultancy, Chesterfield (United Kingdom)

2004-10-22

The article explains the principles of open-loop and closed-loop heat pumps and discusses the use of mine water as a source for ground heat. The use of mine water for space heating or cooling purposes has been demonstrated to be feasible and economic in applications in Scotland, Canada, Norway and the USA. Mine water is an attractive energy resource due to: (1) the high water storage and water flux in mine workings, representing a huge renewable enthalpy reservoir; (2) the possibility of re-branding a potentially polluting environmental liability as a 'green' energy resource; and (3) the development of many mine sites as commercial/industrial parks with large space heating/cooling requirements. The exothermic nature of the pyrite oxidation reaction implies added benefits if closed-loop systems can harness the chemical energy released in mine-waste tips. An appreciation of geochemistry also assists in identifying and solving possible problems with precipitation reactions occurring in heat pump systems. 51 refs., 4 figs., 4 tabs.

Use of buried collector heat pumps in space heating and cooling; Utilisation en chauffage et en refraichissement des thermopompes a capteurs enterres

Energy Technology Data Exchange (ETDEWEB)

Bernier, J [Societe SYREC, 22 - Dinan (France)

1998-12-31

This paper presents a comparative evaluation of the seasonal thermal performances of the different types of heat pumps with buried collectors: ground/ground type, water-glycol water type, and ground/water type. The different systems are also compared with respect to their adaptation to reversibility. A heat pump system for sanitary hot water production is also presented. (J.S.)

Use of buried collector heat pumps in space heating and cooling; Utilisation en chauffage et en refraichissement des thermopompes a capteurs enterres

Energy Technology Data Exchange (ETDEWEB)

Bernier, J. [Societe SYREC, 22 - Dinan (France)

1997-12-31

This paper presents a comparative evaluation of the seasonal thermal performances of the different types of heat pumps with buried collectors: ground/ground type, water-glycol water type, and ground/water type. The different systems are also compared with respect to their adaptation to reversibility. A heat pump system for sanitary hot water production is also presented. (J.S.)

Exergy metrication of radiant panel heating and cooling with heat pumps

International Nuclear Information System (INIS)

Kilkis, Birol

2012-01-01

Highlights: ► Rational Exergy Management Model analytically relates heat pumps and radiant panels. ► Heat pumps driven by wind energy perform better with radiantpanels. ► Better CO 2 mitigation is possible with wind turbine, heat pump, radiant panel combination. ► Energy savings and thermo-mechanical performance are directly linked to CO 2 emissions. - Abstract: Radiant panels are known to be energy efficient sensible heating and cooling systems and a suitable fit for low-exergy buildings. This paper points out the little known fact that this may not necessarily be true unless their low-exergy demand is matched with low-exergy waste and alternative energy resources. In order to further investigate and metricate this condition and shed more light on this issue for different types of energy resources and energy conversion systems coupled to radiant panels, a new engineering metric was developed. Using this metric, which is based on the Rational Exergy Management Model, true potential and benefits of radiant panels coupled to ground-source heat pumps were analyzed. Results provide a new perspective in identifying the actual benefits of heat pump technology in curbing CO 2 emissions and also refer to IEA Annex 49 findings for low-exergy buildings. Case studies regarding different scenarios are compared with a base case, which comprises a radiant panel system connected to a natural gas-fired condensing boiler in heating and a grid power-driven chiller in cooling. Results show that there is a substantial CO 2 emission reduction potential if radiant panels are optimally operated with ground-source heat pumps driven by renewable energy sources, or optimally matched with combined heat and power systems, preferably running on alternative fuels.

Heat pumps in western Switzerland

International Nuclear Information System (INIS)

Freymond, A.

2003-01-01

The past ten years have seen an extraordinary expansion of heat-pump market figures in the western (French speaking) part of Switzerland. Today, more than 14,000 units are in operation. This corresponds to about 18% of all the machines installed in the whole country, compared to only 10 to 12% ten years ago. This success illustrates the considerable know-how accumulated by the leading trade and industry during these years. It is also due to the promotional program 'Energy 2000' of the Swiss Federal Department of Energy that included the heat pump as a renewable energy source. Already in 1986, the Swiss Federal Institute of Technology in Lausanne was equipped with a huge heat pump system comprising two electrically driven heat pumps of 3.5 MW thermal power each. The heat source is water drawn from the lake of Geneva at a depth of 70 meters. An annual coefficient of performance of 4.5 has been obtained since the commissioning of the plant. However, most heat pump installations are located in single-family dwellings. The preferred heat source is geothermal heat, using borehole heat exchangers and an intermediate heat transfer fluid. The average coefficient of performance of these installations has been increased from 2.5 in 1995 to 3.1 in 2002

Heat-pump-centered integrated community energy systems

Energy Technology Data Exchange (ETDEWEB)

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

1979-12-01

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

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

Science.gov (United States)

Li, Na

2018-02-01

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

An Experimental Facility to Validate Ground Source Heat Pump Optimisation Models for the Australian Climate

Directory of Open Access Journals (Sweden)

Yuanshen Lu

2017-01-01

Full Text Available Ground source heat pumps (GSHPs are one of the most widespread forms of geothermal energy technology. They utilise the near-constant temperature of the ground below the frost line to achieve energy-efficiencies two or three times that of conventional air-conditioners, consequently allowing a significant offset in electricity demand for space heating and cooling. Relatively mature GSHP markets are established in Europe and North America. GSHP implementation in Australia, however, is limited, due to high capital price, uncertainties regarding optimum designs for the Australian climate, and limited consumer confidence in the technology. Existing GSHP design standards developed in the Northern Hemisphere are likely to lead to suboptimal performance in Australia where demand might be much more cooling-dominated. There is an urgent need to develop Australia’s own GSHP system optimisation principles on top of the industry standards to provide confidence to bring the GSHP market out of its infancy. To assist in this, the Queensland Geothermal Energy Centre of Excellence (QGECE has commissioned a fully instrumented GSHP experimental facility in Gatton, Australia, as a publically-accessible demonstration of the technology and a platform for systematic studies of GSHPs, including optimisation of design and operations. This paper presents a brief review on current GSHP use in Australia, the technical details of the Gatton GSHP facility, and an analysis on the observed cooling performance of this facility to date.

Computational Simulation of a Water-Cooled Heat Pump

Science.gov (United States)

Bozarth, Duane

2008-01-01

A Fortran-language computer program for simulating the operation of a water-cooled vapor-compression heat pump in any orientation with respect to gravity has been developed by modifying a prior general-purpose heat-pump design code used at Oak Ridge National Laboratory (ORNL).

Energy Performance and Economic Evaluation of Heat Pump/Organic Rankine Cycle System with Sensible Thermal Storage

DEFF Research Database (Denmark)

Carmo, C.; Dumont, O.; Nielsen, M. P.

2016-01-01

that consists of a ground-source heat pump with possibility of reversing operation as an ORC power cycle combined with solar heating in a single-family building is introduced. The ORC mode enables the use of solar energy in periods of no heat energy demand and reverses the heat pump cycle to supply electrical...... power.This paper combines a dynamic model based on empirical data of the HP/ORC system with lessons learned from 140 heat pump installations operating in real-life conditions in a cold climate. These installations were monitored for a period up to 5 years.Based on the aforementioned model and real......-life conditions knowledge, the paper considers two different sensible energy storage (TES) configurations for the reversible heat pump/organic Rankine cycle (HP/ORC) system: a buffer tank for both space heating and domestic hot water and a hot water storage tank used exclusively for domestic hot water...

Heat pumps

CERN Document Server

Brodowicz, Kazimierz; Wyszynski, M L; Wyszynski

2013-01-01

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

A Comparative Cycle and Refrigerant Simulation Procedure Applied on Air-Water Heat Pumps

DEFF Research Database (Denmark)

Mader, Gunda; Palm, Björn; Elmegaard, Brian

2012-01-01

A vapor compression heat pump absorbs heat from the environment at a low temperature level and rejects heat at a high temperature level. The bigger the difference between the two temperature levels the more challenging is it to gain high energy efficiency with a basic cycle layout as found in most...... small capacity heat pump applications today. Many of the applicable refrigerants also reach their technical limits regarding low vapor pressure for very low source temperatures and high discharge temperatures for high sink temperatures. These issues are especially manifest for air-water heat pumps. Many...... alternative cycle setups and refrigerants are known to improve the energy efficiency of a vapor compression cycle and reduce discharge temperatures. However not all of them are feasible for small capacity heat pumps from a cost and complexity point of view. This paper presents a novel numerical approach...

Performance analysis of air source heat pump system for office building

Energy Technology Data Exchange (ETDEWEB)

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

2016-11-15

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

Heat pumps: Technology and economics. (Latest citations from the NTIS bibliographic database). Published Search

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-05-01

The bibliography contains citations concerning the design, construction, and assessment of heat pumps. Absorption, chemical, ground-source, and gas-source heat pumps and systems are reviewed. Cost-benefit analyses, comparative evaluations, and maintenance costs of heat pump systems are presented. Applications in space heating and waste heat recovery are examined. (Contains 50-250 citations and includes a subject term index and title list.)

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

DEFF Research Database (Denmark)

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

2012-01-01

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

Heat pumps for geothermal applications: availability and performance. Final report

Energy Technology Data Exchange (ETDEWEB)

Reistad, G.M.; Means, P.

1980-05-01

A study of the performance and availability of water-source heat pumps was carried out. The primary purposes were to obtain the necessary basic information required for proper evaluation of the role of water-source heat pumps in geothermal energy utilization and/or to identify the research needed to provide this information. The Search of Relevant Literature considers the historical background, applications, achieved and projected performance evaluations and performance improvement techniques. The commercial water-source heat pump industry is considered in regard to both the present and projected availability and performance of units. Performance evaluations are made for units that use standard components but are redesigned for use in geothermal heating.

Estimating the CO2 mitigation potential of horizontal Ground Source Heat Pumps in the UK

Science.gov (United States)

Garcia-Gonzalez, R.; Verhoef, A.; Vidale, P. L.; Gan, G.; Chong, A.; Clark, D.

2012-04-01

By 2020, the UK will need to generate 15% of its energy from renewables to meet our contribution to the EU renewable energy target. Heating and cooling systems of buildings account for 30%-50% of the global energy consumption; thus, alternative low-carbon technologies such as horizontal Ground Couple Heat Pumps (GCHPs) can contribute to the reduction of anthropogenic CO2 emissions. Horizontal GCHPs currently represent a small fraction of the total energy generation in the UK. However, the fact that semi-detached and detached dwellings represent approximately 40% of the total housing stocks in the UK could make the widespread implementation of this technology particularly attractive in the UK and so could significantly increase its renewable energy generation potential. Using a simulation model, we analysed the dynamic interactions between the environment, the horizontal GCHP heat exchanger and typical UK dwellings, as well as their combined effect on heat pump performance and CO2 mitigation potential. For this purpose, a land surface model (JULES, Joint UK Land Environment Simulator), which calculates coupled soil heat and water fluxes, was combined with a heat extraction model. The analyses took into account the spatio-temporal variability of soil properties (thermal and hydraulic) and meteorological variables, as well as different horizontal GCHP configurations and a variety of building loads and heat demands. Sensitivity tests were performed for four sites in the UK with different climate and soil properties. Our results show that an installation depth of 1.0m would give us higher heat extractions rates, however it would be preferable to install the pipes slightly deeper to avoid the seasonal influence of variable meteorological conditions. A value of 1.5m for the spacing between coils (S) for a slinky configuration type is recommended to avoid thermal disturbances between neighbouring coils. We also found that for larger values of the spacing between the coils

Heat pump technology

CERN Document Server

Von Cube, Hans Ludwig; Goodall, E G A

2013-01-01

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

National Certification Standard for Ground Source Heat Pump Personnel

Energy Technology Data Exchange (ETDEWEB)

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

2013-07-31

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

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

Energy Technology Data Exchange (ETDEWEB)

Tippelt, Egbert [Viessmann, Allendorf (Germany)

2011-12-15

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

Comparison between design and actual energy performance of a HVAC-ground coupled heat pump system in cooling and heating operation

Energy Technology Data Exchange (ETDEWEB)

Magraner, T.; Quilis, S. [Energesis Ingenieria S.L., Ciudad Politecnica de la Innovacion, Camino de Vera s/n, 46022 Valencia (Spain); Montero, A. [Instituto de Ingenieria Energetica, Universidad Politecnica de Valencia, Camino de Vera s/n, 46022 Valencia (Spain); Urchueguia, J.F. [Instituto Universitario de Matematica Pura y Aplicada, Universidad Politecnica de Valencia, Camino de Vera s/n, 46022 Valencia (Spain)

2010-09-15

This work compares the experimental results obtained for the energy performance study of a ground coupled heat pump system with the design values predicted by means of standard methodology. The system energy performance of a monitored ground coupled heat pump system is calculated using the instantaneous measurements of temperature, flow and power consumption and these values are compared with the numerical predictions. These predictions are performed with the TRNSYS software tool following standard procedures taking the experimental thermal loads as input values. The main result of this work is that simulation results solely based on nominal heat pump capacities and performances overestimate the measured overall energy performance by a percentage between 15% and 20%. A sensitivity analysis of the simulation results to changes in percentage of its input parameters showed that the heat pump nominal coefficient of performance is the parameter that mostly affects the energy performance predictions. This analysis supports the idea that the discrepancies between experimental results and simulation outputs for this ground coupled system are mainly due to heat pump performance degradation for being used at partial load. An estimation of the impact of this effect in energy performance predictions reduces the discrepancies to values around 5%. (author)

HEAT PUMP TECHNOLOGY – POTENTIAL IMPACT ON ENERGY EFFICIENCY PROBLEM AND CLIMATE ACTION GOALS WITHIN UKRAINIAN ENERGY SECTOR

Directory of Open Access Journals (Sweden)

O. Ostapenko

2015-12-01

Full Text Available The increasing demand of energy sources for urban, household and industrial facilities requires strategies development for seeking new energy sources. In recent years an important problem is to have energy storage, energy production and energy consumption which fulfill the environment friendly expectations. A lot of attention is devoted to renewable energy sources. One of the most attracting among them is energy production form geothermal sources. At a few meters below the earth’s surface the underground maintains a constant temperature in an approximation through the year allowing to withdraw heat in winter for heating needs and to surrender heat during summer for air-conditioning purposes. Heat pump is a rapidly developing technology for heating and domestic hot water production. Using ground as a heat source, heat exchange is carried out with heat pumps compound to vertical ground heat exchanger tubes that allows the heating and cooling of the buildings utilizing a single unit installation. Heat pump unit provides a high degree of productivity with moderate electric power consumption. In this paper a theoretical performance study of a vapor compression heat pump system with various natural and synthetic refrigerants (HFCs is presented. Operation mode of the heat pump unit was chosen according to European Standard EN14511-2:2007 and EN255-2. An influence of discharge temperature on system performance was evaluated at different boiling temperatures. The comparison of mass flow rate and coefficient of performance for considered refrigerants at constant cooling capacity and condensation temperature was performed.

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

Science.gov (United States)

Juhlin, K.; Gehlin, S.

2016-12-01

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

Quantification of exploitable shallow geothermal energy by using Borehole Heat Exchanger coupled Ground Source Heat Pump systems

International Nuclear Information System (INIS)

Hein, Philipp; Zhu, Ke; Bucher, Anke; Kolditz, Olaf; Pang, Zhonghe; Shao, Haibing

2016-01-01

Highlights: • The amount of technically exploitable shallow geothermal energy was quantified. • Therefore, a comprehensive numerical borehole heat exchanger model was employed. • The concept of equivalent temperature drop is introduced. • For one BHE, an equivalent temperature drop of 1.8–2.8 °C over 30 years is realistic • The average extractable energy amount evaluates to be 3.5–5.4 kW h m"−"2 a"−"1. - Abstract: In previous studies, the amount of exploitable shallow geothermal energy was estimated by assuming a uniform temperature drop of 2–6 °C in the aquifer. In this work, a more comprehensive numerical model has been employed to evaluate the available amount of shallow geothermal energy by using Borehole Heat Exchanger coupled Ground Source Heat Pump systems. Numerical experiments have been performed by simulating the long-term evolution of the subsurface temperature field, which is subject to the operation of borehole heat exchangers and varying parameters like subsurface thermal conductivity and groundwater flow velocity. The concept of equivalent temperature drop is proposed as an auxiliary quantity for the subsurface. With the help of this parameter, a procedure has been established to quantify the amount of shallow geothermal potential. Following this approach, a realistic equivalent temperature reduction is found to be from −1.8 to −4.4 °C in the subsurface over a period of 30 years. This can be translated to an annual extractable geothermal energy value in a unit surface area, and it ranges from 3.5 to 8.6 kW h m"−"2 a"−"1. The exact value is site specific and heavily depends on the soil thermal conductivity, groundwater velocity, and borehole arrangement.

The Strategic Exercise of Options Using Government Subsidies: An Analysis of Production Subsidies for the Ground Source Heat Pump

Science.gov (United States)

Lin, Sheng-Hau; Li, Jia-Hsun; Hsu, Chih-Chen; Hsieh, Jing-Chzi; Liao, Pin-Chao

2018-04-01

This study utilizes consolidation investment theory to incorporate with business strategies and government subsidy to develop a strategic exercise of options model. This empirical investigation examines the ground source heat pump (GSHP) government subsidy program, which is part of China’s 12th Five Year Plan. The developed model is applied to explain the behaviours of business investment with regard to strategic investment timing, option values, and the influence of government subsidies in duopolistic real-world investment decisions. The results indicate that subsidy policy can reduce the differences of investment timing among GSHP investors and has clearly evidenced the positive benefit–cost ratio of government subsidy, which facilitates China’s GSHP industry development.

Heat pumps: Industrial applications. (Latest citations from the NTIS bibliographic database). Published Search

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-04-01

The bibliography contains citations concerning design, development, and applications of heat pumps for industrial processes. Included are thermal energy exchanges based on air-to-air, ground-coupled, air-to-water, and water-to-water systems. Specific applications include industrial process heat, drying, district heating, and waste processing plants. Other Published Searches in this series cover heat pump technology and economics, and heat pumps for residential and commercial applications. (Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

Heat pumps: Industrial applications. (Latest citations from the NTIS bibliographic database). Published Search

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-01-01

The bibliography contains citations concerning design, development, and applications of heat pumps for industrial processes. Included are thermal energy exchanges based on air-to-air, ground-coupled, air-to-water, and water-to-water systems. Specific applications include industrial process heat, drying, district heating, and waste processing plants. Other Published Searches in this series cover heat pump technology and economics, and heat pumps for residential and commercial applications. (Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

DEA (data envelopment analysis)-assisted supporting measures for ground coupled heat pumps implementing in Italy: A case study

International Nuclear Information System (INIS)

Longo, L.; Colantoni, A.; Castellucci, S.; Carlini, M.; Vecchione, L.; Savuto, E.; Pallozzi, V.; Di Carlo, A.; Bocci, E.; Moneti, M.; Cocchi, S.; Boubaker, K.

2015-01-01

Nowadays, the increasing of the energy consumption is producing serious global warming issues. Mainly most of greenhouse gas emissions in developed countries come from building equipments. In this context, GCHPs (ground coupled heat pumps) are candidate solution as air conditioning systems in buildings due to their higher efficiency compared to conventional devices. Actually, ground coupled heat pump systems are widely, recognized among the most efficient and comfortable used systems. Nevertheless, economic efficiency of the ground coupled heat pumps has to be proved. In this study, DEA (data envelopment analyses) method is applied to a real case in Italy. - Highlights: • Original investigation in terms of energy demands in buildings. • Gathering conjoint classical and scientific analyses. • Presenting original DEA (data envelopment analysis) economic optimization scheme analyses. • Outlining economical feasibility of an efficient low enthalpy-geothermal plant with GCHP (ground coupled heat pump) exchangers.

Verification of the Performance of a Vertical Ground Heat Exchanger Applied to a Test House in Melbourne, Australia

Directory of Open Access Journals (Sweden)

Koon Beng Ooi

2017-10-01

Full Text Available The ground heat exchanger is traditionally used as a heat source or sink for the heat pump that raises the temperature of water to about 50 °C to heat houses. However, in winter, the heating thermostat (temperature at which heating begins in the Australian Nationwide House Energy Rating Scheme (NatHERS is only 20 °C during daytime and 15 °C at night. In South-East Melbourne, the temperature at the bottom of a 50-meter-deep borehole has been recorded with an Emerson™ recorder at 17 °C. Melbourne has an annual average temperature of 15 °C, so the ground temperature increases by 2 °C per 50-m depth. A linear projection gives 23 °C at 200-m of depth, and as the average undisturbed temperature of the ground for a 400-m-deep vertical ground heat exchanger (VGHE. This study, by simulation and experimentation, aims to verify that the circulation of water in the VGHE’s U-tube to low-temperature radiators (LTRs could heat a house to thermal comfort. A literature review is included in the introduction. A simulation, using a model of a 60-m2 experimental house, shows that the daytime circulation of water in this VGHE/LTR-on-opposite-walls system during the 8-month cold half of the year, heats the indoors to NatHERS settings. Simulation for the cold half shows that this VGHE-LTR system could cool the indoors. Instead, a fan creating a cooling sensation of up to 4 °C is used so that the VGHE is available for the regeneration of heat extracted from the ground during the cold portion. Simulations for this hot portion show that a 3.4-m2 flat plate solar collector can collect more than twice the heat extracted from the ground in the cold portion. Thus, it can thus replenish the ground heat extracted for houses double the size of this 60-m2 experimental house. Therefore, ground heat is sustainable for family-size homes. Since no heat pump is used, the cost of VGHE-LTR systems could be comparable to systems using the ground source heat pump. Water

Study on hybrid ground-coupled heat pump system for air-conditioning in hot-weather areas like Hong Kong

Energy Technology Data Exchange (ETDEWEB)

Man, Y.; Yang, H.X. [Hong Kong Polytechnic Univ., Renewable Energy Research Group, Hung Hom, Kowloon, (Hong Kong). Dept. of Building Services Engineering

2008-07-01

Due to its high energy efficiency and reliable operation capability, the ground-coupled heat pump (GCHP) system is becoming attractive for air-conditioning in some moderate-weather regions. However, when the technology is used in buildings where there is only cooling load in hot-weather areas such as Hong Kong, the heat rejected into the ground by the GCHP systems will accumulate around the ground heat exchangers (GHE), resulting in degradation of system performance and increased system operating costs. This problem can be resolved by using a hybrid ground-coupled heat pump (HGCHP) system, as it uses supplemental heat rejecters to reject the accumulated heat. By modeling the heat transfer process of the system's main components, this paper presented a practical hourly simulation model of the HGCHP system. Based on this hourly simulation model, the computer program could be used to calculate the hour-by-hour operation data of the HGCHP system according to the cooling and hot water heating loads of a building. The paper discussed a case study that involved a design of both a HGCHP system and a traditional GCHP system for a hypothetical private residential building located in Hong Kong. The economic comparisons were performed between these two types of systems. It was concluded through the simulations that the HGCHP system could effectively solve the heat accumulation problem and reduce both the initial cost and operating cost of the air-conditioning system in the building. 19 refs., 1 tab., 13 figs.

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

Institute of Scientific and Technical Information of China (English)

ZHAO Jun; CHEN Yan; LU Suzhen; CUI Junkui

2009-01-01

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

太阳能与地源热泵联合温室大棚系统的设计%System design of solar greenhouses combined with ground source heat pump

Institute of Scientific and Technical Information of China (English)

苏伟; 穆青; 董继先; 王彬权

2015-01-01

Greenhouse is an irreplaceable technology in modern agriculture, but it was easily affected by weather. The combination of solar energy-ground source heat pump system can make full use of the complementary advantages of both of them.It confirmed the stable operation of greenhouses all year round.Therefore, a solar greenhouse com-bined with ground source heat pump system and the PLC control circuit of the system were designed, and the brief a-nalysis on the feasibility was carried out.It also provides certain reference and suggestion about subsequent applica-tion of the greenhouses combined with solar energy and ground source heat pump system.%温室大棚是现代农业中不可替代的技术，但其受天气影响比较大，采用太阳能—地源热泵联合系统作业的方式，可充分利用二者的优势，使得温室大棚一年四季稳定运行。为此，设计了太阳能与地源热泵联合温室大棚系统及该系统的PLC控制回路，并对其可行性进行了简要分析，可为后续太阳能—地源热泵联合系统在温室大棚中的应用提供参考。

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

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-03-01

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

Commercial Integrated Heat Pump with Thermal Storage --Demonstrate Greater than 50% Average Annual Energy Savings, Compared with Baseline Heat Pump and Water Heater (Go/No-Go) FY16 4th Quarter Milestone Report

Energy Technology Data Exchange (ETDEWEB)

Shen, Bo [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Baxter, Van D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Rice, C. Keith [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Abu-Heiba, Ahmad [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

2017-03-01

For this study, we authored a new air source integrated heat pump (AS-IHP) model in EnergyPlus, and conducted building energy simulations to demonstrate greater than 50% average energy savings, in comparison to a baseline heat pump with electric water heater, over 10 US cities, based on the EnergyPlus quick-service restaurant template building. We also assessed water heating energy saving potentials using ASIHP versus gas heating, and pointed out climate zones where AS-IHPs are promising.

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.

Modeling of an Air Conditioning System with Geothermal Heat Pump for a Residential Building

Directory of Open Access Journals (Sweden)

Silvia Cocchi

2013-01-01

Full Text Available The need to address climate change caused by greenhouse gas emissions attaches great importance to research aimed at using renewable energy. Geothermal energy is an interesting alternative concerning the production of energy for air conditioning of buildings (heating and cooling, through the use of geothermal heat pumps. In this work a model has been developed in order to simulate an air conditioning system with geothermal heat pump. A ground source heat pump (GSHP uses the shallow ground as a source of heat, thus taking advantage of its seasonally moderate temperatures. GSHP must be coupled with geothermal exchangers. The model leads to design optimization of geothermal heat exchangers and to verify the operation of the geothermal plant.

Corrosion protection of steel in ammonia/water heat pumps

Science.gov (United States)

Mansfeld, Florian B.; Sun, Zhaoli

2003-10-14

Corrosion of steel surfaces in a heat pump is inhibited by adding a rare earth metal salt to the heat pump's ammonia/water working fluid. In preferred embodiments, the rare earth metal salt includes cerium, and the steel surfaces are cerated to enhance the corrosion-inhibiting effects.

Champagne Heat Pump

Science.gov (United States)

Jones, Jack A.

2004-01-01

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

Laboratory Performance Evaluation of Residential Integrated Heat Pump Water Heaters

Energy Technology Data Exchange (ETDEWEB)

Sparn, B.; Hudon, K.; Christensen, D.

2014-06-01

This paper explores the laboratory performance of five integrated Heat Pump Water Heaters (HPWHs) across a wide range of operating conditions representative of U.S. climate regions. HPWHs are expected to provide significant energy savings in certain climate zones when compared to typical electric resistance water heaters. Results show that this technology is a viable option in most climates, but differences in control schemes and design features impact the performance of the units tested. Tests were conducted to map heat pump performance across the operating range and to determine the logic used to control the heat pump and the backup electric heaters. Other tests performed include two unique draw profile tests, reduced air flow performance tests and the standard DOE rating tests. The results from all these tests are presented here for all five units tested. The results of these tests will be used to improve the EnergyPlus heat pump water heater for use in BEopt™ whole-house building simulations.

Laboratory Performance Evaluation of Residential Integrated Heat Pump Water Heaters

Energy Technology Data Exchange (ETDEWEB)

Sparn, B.; Hudon, K.; Christensen, D.

2014-06-01

This paper explores the laboratory performance of five integrated Heat Pump Water Heaters (HPWHs) across a wide range of operating conditions representative of US climate regions. HPWHs are expected to provide significant energy savings in certain climate zones when compared to typical electric resistance water heaters. Results show that this technology is a viable option in most climates, but differences in control schemes and design features impact the performance of the units tested. Tests were conducted to map heat pump performance across the operating range and to determine the logic used to control the heat pump and the backup electric heaters. Other tests performed include two unique draw profile tests, reduced air flow performance tests and the standard DOE rating tests. The results from all these tests are presented here for all five units tested. The results of these tests will be used to improve the EnergyPlus heat pump water heater for use in BEopt(tm) whole-house building simulations.

Optimization of ground source heat pumps systems through the implementation of hybrid systems; Optimizacion de las instalaciones de bomba de calor geotermica mediante la implementacion de sistemas hibridos

Energy Technology Data Exchange (ETDEWEB)

Magraner, T.; Quilis, M. S.; Martinez, S.

2009-07-01

One of the fundamental aspects to consider in the design of a ground heat pump system is the heat balance in the ground since thermal saturation of the ground produces a decreasing of the performance of the system throughout its useful life. The hybrid geothermal system which combined geothermal heat pump system with other systems for generation or dissipation energy are very suitable for balancing the heat exchanger meters needed for the proper functioning of the system, important aspect to reduce costs and achieve attractive return periods of the initial investment. Energesis Ingenieria has developed and implemented in two office buildings, a design of hybrid systems based on the combination of a geothermal heat pump and air-condensed units (dry coolers) that can ensure energy efficiencies comparable to geothermal pure systems, reducing substantially the investment cost. (Author) 5 refs.

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

Energy Technology Data Exchange (ETDEWEB)

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

1998-04-01

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

Surface-near geothermal energy. Ground coupled heat pumps and underground thermal energy storage; Oberflaechennahe Geothermie. Erdgekoppelte Waermepumpen und unterirdische thermische Energiespeicher

Energy Technology Data Exchange (ETDEWEB)

NONE

2011-07-01

Within the eleventh International User Forum at 27th/28th September, 2011 in Regensburg (Federal Republic of Germany) the following lectures were held: (1) Ecologic evaluation of heat pumps - a question of approach (Roland Koenigsdorff); (2) An actual general comment to WHG, the preparations for the new VAUwS and possible consequences on the surface-near geothermal energy (Walker-Hertkorn); (3) Field-test experiences: Ground source heat pumps in small residential buildings (Jeannette Wapler); (4) GeoT*SOL basic - Program for the evaluation and simulation of heat pump systems (Bernhard Gatzka); (5) Monitoring and modelling of geothermal heat exchanger systems (Fabian Ochs); (6) Thermal response tests for the quality assurance of geothermal heat probes (Markus Proell); (7) Process of determining an untroubled soil temperature in comparison (Andreas Koehler); (8) Borehole resistance - Is the TRT measured value also the planning value? (Roland Koenigsdorff); (9) Consideration of the heat transport in geothermal probes (Martin Konrad); (10) Process of evaluation the sealing of geothermal probes with backfilling materials (Manfred Reuss); (11) Quality assessment of geothermal probes in real standard (Mathieu Riegger); (12) Comparison of flat collectors salt water and direct evaporation, design, impacs, consequences (Bernhard Wenzel); (13) Non-covered photovoltaic thermal collectors in heat pump systems (Erik Bertram); (14) Seasonal geothermal probe-heat storage - Heat supply concepts for objects with overbalancing heating level of more than 100 kW (Volker Liebel); (15) Application of geothermal probe fields as a cold storage (Rolf Wagner); (16) Geothermal energy and waste water warmth: State of the art and new technologies for a combined utilization (Wolfram Stodtmeister); (17) Integration of a heat pump into a solar supported local heat supply in Neckarsulm (Janet Nussbicker-Lux); (18) Regenerative heating with photovoltaics and geothermal energy (Christoph Rosinski

Engineering Design and Economic Analysis of Air Source Heat Pump Assisted Solar Water Heating System%热泵+太阳能热水系统的工程设计与经济分析

Institute of Scientific and Technical Information of China (English)

李永华

2013-01-01

以空气源热泵为辅助热源的太阳能集中热水系统，不仅节能效率高，而且能保证全天候连续热水供应，是近年来太阳能利用的发展方向之一。淮海工学院学生浴室采用了空气源热泵辅助太阳能热水系统，设计用水人数17000人，日需热水量184 t。介绍了该热水系统的工作原理及设计计算，并对5种热水工程方案从初期投资和运行费用方面进行了详细的经济性分析，结果表明：以空气源热泵为辅助热源的热水方案较其他方案具有更好的经济、环保效益。%The high energy-efficient solar energy water heating system in conjunction with air source heat pump, supplying all-weather continuous hot water, is one of the developing direction of solar energy utilization in recent years. Students ’ Bathroom of Huaihai Institute of Technology use solar water heating system assisted with air source heat pump for 17000 students, requiring 184 tons of hot water every day. The working principle and design calculation of hot water system are expounded with detailed analysis of the initial investment and operating costs for five kinds of heating water engineering solutions. Results show that air source heat pump as auxiliary heat source has better economic and environmental benefits.

Absorption heat pumps

International Nuclear Information System (INIS)

Formigoni, C.

1998-01-01

A brief description of the difference between a compression and an absorption heat pump is made, and the reasons why absorption systems have spread lately are given. Studies and projects recently started in the field of absorption heat pumps, as well as criteria usually followed in project development are described. An outline (performance targets, basic components) of a project on a water/air absorption heat pump, running on natural gas or LPG, is given. The project was developed by the Robur Group as an evolution of a water absorption refrigerator operating with a water/ammonia solution, which has been on the market for a long time and recently innovated. Finally, a list of the main energy and cost advantages deriving from the use of absorption heat pumps is made [it

Solar-assisted ground-source heat pump system design and case study%太阳能辅助地埋管地源热泵系统设计及实例分析

Institute of Scientific and Technical Information of China (English)

季永明; 端木琳; 李祥立

2017-01-01

Presents an improved method to determine the solar collector area of the solar-assisted ground-source heat pump system based on the heat balance method.For a commercial building in Dalian,proposes the design scheme of a solar-assisted ground-source heat pump system.Simulates the operating parameters of the system by TRNSYS,and the results show that,on the basis of ensuring the heating capacity of the building,the system guarantees the average temperature of the thermal storage soil which contains the ground heat exchanger periodic and consistent change,and the COP of the heat pump is improved significantly compared with that of the system without solar collectors in winter.%基于热平衡法提出了确定太阳能辅助地埋管地源热泵系统中太阳能集热器面积的方法.针对大连地区一公共建筑,提出了太阳能辅助地埋管地源热泵系统设计方案.采用TRNSYS软件对该系统运行参数进行了仿真模拟,结果显示,在保证建筑供热量的基础上,系统能长期保证热泵源侧换热器所在蓄热土壤平均温度呈周期性一致变化,且冬季热泵机组COP较无集热器工况显著提高.

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

Science.gov (United States)

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

2018-01-01

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

Guide to North Dakota's ground-water resources

Science.gov (United States)

Paulson, Q.F.

1983-01-01

Ground water, the water we pump from the Earth through wells or that which flows naturally from springs, is one of North Dakota's most valuable resources. More than 60 percent of the people living in the State use ground water for one purpose of another. It is the only source of water for thousands of farm families and their livestock. Almost all smaller cities and villages depend solely on groudn water as a source of supply. Increasingly, ground water is being used to irrigate crops and grasslands (fig. 1) during protracted dry spells so common in North Dakota. During recent years there has been a rapid development of rural water ditribution systems in which thousands of farms and rurals residences are connected via underground pipeline to a single water source, usually wells pumping ground water.