• Proceedings of the SAREK Conference
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• 2007.11a
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• pp.82-87
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• 2007

In the present study, the simulation on the annual performance evaluation of a renewable energy systems with fuel cell driven compound source hybrid heat pump systems is applied to the heating and cooling of large community building. The large community building has the economical advantage to apply heat pump cooling and heating systems the long period operation. If air and ground source hybrid heat pump systems are combined, COP of the system can be increased largely. Fuel cell driven compound source hybrid heat pump system can reduced the fuel cost as well as thermal storage tank sharply.

• Proceedings of the SAREK Conference
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• 2008.11a
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• pp.21-26
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• 2008

Recently, small and medium-sized buildings have employed a multi-heat pump. The major benefits of the multi-heat pump over a conventional system are that it is easier system to maintain along with a diversification of facility use, and high comfortability. The performance of multi-heat pump systems can be enhanced by using geothermal energy instead of air source energy. This paper describes the multi-heat pumps applied in an ground source heat pump system for an actual building. The performance of a ground source multi-heat pump installed in the field was investigated in cooling mode. The maximum COP of the systems with single U-tube and double tube ground loop heat exchangers were 6.6 and 6.0, respectively. It is suggested that the new algorithms to control the flow rate of secondary fluid for ground loop heat exchanger have to be developed in order to enhance the performance of the system.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.15 no.1
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• pp.59-66
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• 2003

The purpose of this study is to analyze the characteristics (COP) of the heat pump system for various operating conditions with the use of seawater heat source and exhaust energy. To accomplish the goal, first of all, the computer simulation for heat pump system is carried out. The heat pump system model is made of a waste heat recovery system and a vapor compression refrigeration system, and the working fluid is R-22. The model calculated the change of COP with the variation of temperature and flow rate. The COP and the plate heat exchanger (PHE) area of the heat pump system are considered moderately high in the condensation temperature of $25^{\circ}^C$ and the evaporation temperature of $2^{\circ}^C$ in indoor culture system. The simulation results will be used effectively for the design and the performance prediction of heat pump system using unused energy in a land base aquaculture system.

• Proceedings of the SAREK Conference
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• 2006.06a
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• pp.915-920
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• 2006

Recently available heat pump system by using air heat-source is not efficient. Because the mean temperature of korean winter season is low, economy of air heat-source heat pump descend, and COP is below 3.0. This paper was practiced the simulation on evaluation criteria for heat pump heating and cooling systems to resident building. As a result, heating and cooling composition heat pump system apply to the building needed to be provided heat source for 24 hours.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.22 no.6
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• pp.337-344
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• 2010

Good plant-growth conditions can be achieved by means of using greenhouses. One of the main issues in greenhouse cultivation is energy savings through the development of high efficient heating and cooling system. GSHPs are one of the recommended systems to cope with this pending need. The aim of this study is to investigate the heating performance of ground source multi-heat pump system installed in a greenhouse under part load conditions. Daily average heating COP of the heat pump unit was very high by at least 7.4, because of relatively large condenser, evaporator, and mass flow rate through ground loop heat exchanger. However, the system COP, overall heating coefficient of the performance of the system with heat pump unit and GLHX, decreased drastically due to relatively large power consumption of circulating pump under part load condition. It is suggested that the technology to enhance the performance of the ground source multi-heat pump system for a greenhouse under part load conditions should be developed.

• Journal of Advanced Marine Engineering and Technology
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• v.40 no.7
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• pp.563-568
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• 2016

In this study, experiments were conducted to evaluate the performance of a heat pump system. A heat pump system with an air as heat source is adapted as reference. The developed system uses a plate heat exchanger an evaporator to absorb heat from a stack of fuel cell driven electric vehicles. Hence, the system functions as a water source heat pump system. The results indicated that the; power consumption increased with the rotational speed of the compressor. A system performance($COP_h$) of 2.03 at an electronic expansion valve(EEV) openings of 25% and a compressor speed of 1200 rpm was observed in the reference system. However, at the same compressor speed, the $COP_h$ of the water source heat pump system corresponded to 9.42 at an EEV openings of 75%. It was found that the water source heat pump system exhibited the highest performance at a water temperature of $50^{\circ}C$.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.14 no.1
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• pp.1-7
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• 2018

A ground source heat pump system should be equipped with devices to measure the generated heating or cooling heat amount in Korea. Generally, the heat measuring devices have been developed to estimate consumed heat amount in residential or commercial buildings from a central air-conditioning system or a district heating system. In this study, two representive heat measuring devices used for buildings were selected, and the accuracy of them were experimentally estimated at the ground source heat pump operating conditions. The obtained heat amounts from the heat measuring devices were deviated within 4.3% comparing with the precise values calculated from an accredited test facility. Even though the accumulated heat amount values of the heat measuring devices had a small difference comparing with the precise values, the temperatures of heat measuring devices showed greatly different values comparing with the precise temperature. Therefore, it is highly recommended to develop the heat measuring devices which is appropriate for the ground source heat pump systems.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.25 no.3
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• pp.131-136
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• 2013

The present study has conducted cycle design and control technology of a water source VRF heat pump system. Previously, study of a simultaneous heating and cooling in an air source VRF heat pump system has been conducted. However, performance data and design methods for simultaneous heating and cooling in a water source VRF heat pump system are limited in the literature, due to various system parameters and operating conditions. In this study, the operating characteristics and performances of a simultaneous heating and cooling heat pump system are carried out, in simultaneous operation modes. Control logics of an EEV are developed for flow rate control to the outdoor unit, and are verified. When the control logics are applied, the simultaneous cooling and heating performances are sufficiently achieved, and system COPs are increased by up to 23.4%.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.25 no.11
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• pp.600-605
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• 2013

Ground source heat pump systems (GSHP) can achieve higher performance of the system, by supplying more efficient heat source to the heat pump, than the conventional air-source heat pump system. But building clients and designers have hesitated to use GSHP systems, due to expensive initial cost, and uncertain economic feasibility. In order to reduce the initial cost, many researches have focused on the energy-pile system, using the structure of the building as a heat exchanger. Even though several experimental studies for the energy-pile system have been conducted, there was not enough data of quantitative evaluation with economic analysis and comprehensive analysis for the energy-pile. In this study, a prediction method has been developed for the energy pile system with barrette pile, using the ground heat transfer model and ground heat exchanger model. Moreover, a feasibility study for the energy pile system with barrette pile was conducted, by performance analysis and LCC assessment. As a result, it was found that the heat exchange rate of a barrette pile was 2.55 kW, and the payback period using LCC analysis was 8.8 years.

• Proceedings of the SAREK Conference
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• 2005.11a
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• pp.173-178
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• 2005

Recently. we interested in renewable energy due to cost increase of the crude oil, etc. In this study solar assisted hybrid heat pump system that uses the solar heat and air as heat source analyzed by experimentally.'rho system could runs at dual mode. One is thermal storage mode of solar energy at day time and the other is heat pump mode with low temperature air as heat source at night time. In case of setting temperature over the limited range. high temperature water heated at the solar energy collecting tubes supplied to the storage tank. As results. it is founded that the heat pump performance Is higher than general heat pump which using the only air as a heat source. The developed system could be used as main healing equipment for the panel heating for the residential house.