• Proceedings of the SAREK Conference
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• 2008.06a
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• pp.833-837
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• 2008

GSHP(Ground Source Heat Pump) has been extensively disseminated due to the recent increasing demand over new and renewable energy. In this study, the operating performance of rain water and ground source heat pump system (RW-GSHP) was compared with GSHP during the heating test. Leaving load temperature(LLT) was $50^{\circ}C$, $53^{\circ}C$, $56^{\circ}C$, respectively and rain water tank temperature(RWT) was $13^{\circ}C$, $15^{\circ}C$, $17^{\circ}C$ in this heating test. The experiment was focused on comparison of the system operating performance depending on leaving load temperature (LLT) and rain water tank temperature (RWT). The results showed that rain water and ground source heat pump system (RW-GSHP) was higher heating performance and COPh than those of GSHP.

• Journal of the Korean Solar Energy Society
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• v.26 no.2
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• pp.95-101
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• 2006

The purpose of this study is to present the simulation results and an overview of the performance assessment of the Ground-Source Heat Pump(GSHF) system. The calculation was performed for two design factors: the spacing between boreholes and the depth of the vertical ground heat exchangers. And the simulation was carried out using the thermal simulation code TRNSYS with new model of water to water heat pump developed by this study. As a result, it was anticipated that the yearly mean COPs of heat pump for heating and cooling are about 3.7 and 5.8 respectively and the heat pump can supply 100% of heating and cooling load all the year around.

• Proceedings of the SAREK Conference
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• 2005.11a
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• pp.167-172
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• 2005

The purpose of this study is to present the simulation results and an overview of the performance assessment of the Ground-Source Heat Pump(GSHP) system. The calculation was performed for two design factors. the spacing between boreholes and the depth of the vertical ground heat exchangers. And the simulation was carried out using the thermal simulation code TRNSYS with new model o( water to water heat pump developed by this study. As a result, it was anticipated that the yearly mean COPs of heat pump for heating and cooling are about 3.7 and 5.8 respectively and the heat pump can supply 100% of heating and cooling load all the year around.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.26 no.5
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• pp.212-217
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• 2014

Recently, the use of renewable energy has been increased due to growing concern on the energy-saving at buildings and the reduction of $CO_2$ emission. In the field of architecture, to reduce the energy consumption of heating, cooling and hot water supply, heat pump systems with renewable energy has been developed and used in various applications. However, there have been many of researches on the large-scale commercial heat pump systems, but the research and the field application of a compact heat pump system is rare. Therefore, in order to develop the compact heat pump for the small-scale residential building, this study conducted the performance test and feasibility study for a hybrid heat pump using the heat source of air, solar and ground. In the results of experiments through a trial product, the average COP of cooling mode with ground heat source was 4.75, and it of heating mode was 4.03. Furthermore, the average COP of cooling mode with air heat source was 2.60, and it of heating mode was 2.92. Finally, payback period of the system was calculated as 9.2 years.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.21 no.8
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• pp.468-474
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• 2009

Ground water source heat pump system is the oldest one of the ground source heat pump systems. Despite of this, little formal design information has been available until recently. The important design parameters for open system are the identification of optimum ground water flow, heat exchanger selection and well pump. In this study, the capacity of 50 RT system of two well type ground water heat pump system was used. As a result, static water level was -7 m and the level during the heating operation was -32 m, cooling operation was -40 m. The initial static water level recovered within 48 hrs. The temperature of ground water is $15.6^{\circ}C$ for heating season and $16.2^{\circ}C$ for cooling season and does not depend on the outdoor temperature. Operation efficiency of the system shows that, COP 3.1 for heating and COP 4.2 for cooling.

• 한국신재생에너지학회:학술대회논문집
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• 2009.11a
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• pp.561-566
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• 2009

Alluvium is sedimentary stratum and composed of gravel, sand, silt, clay. Permeability of alluvium is the higher. If alluvium have lots of aquifer, will be of great use heat source and heat sink of heat pump. Alluvium aquifer contain the thermal energy of surrounding ground. Also geothermal heat pump using alluvium aquifer reduce expenses than general geothermal heat pump, because geothermal heat pump using alluvium aquifer make use of single well. In this study geothermal heat pump using alluvium aquifer was installed and tested for a building. The heat pump capacity is 30USRT. Temperature of ground water is in $12{\sim}17^{\circ}C$ annually and the quality of the water is as good as living water. The heat pump cooling COP is 4.4 ~ 4.7. The system cooling COP is 3.25 ~ 3.6. This performance is as good as BHE type ground source heat pump.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.25 no.8
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• pp.443-449
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• 2013

The purpose of this study is to propose an enhanced variable-speed control method of ground-water circulation pumps using inlet and outlet ground-water temperature difference and analyze its effect for the ground source multi-heat pump system installed in a single-family house. As a result, it has shown to significantly reduce the electricity use of ground-water circulation pump and improve overall system Coefficient of Performance (COP) due to the proposed variable-speed control under partial load conditions after oversized and inefficient single-speed pump retrofit.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.17 no.1
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• pp.71-81
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• 2005

The main objective of the present study is to investigate the performance characteristics of a ground-source heat pump(GSHP) system with a 130 m vertical and 62 mm nominal diameter U-tube ground heat exchanger. In order to evaluate the performance analysis, the ground-source heat pump connected to a test room with $90\;m^2$ floor area in the Korea Institute of Construction $Technology(37^{\circ}39'N,\;126^{\circ}48'E)$ was designed and constructed. This ground-source heat pump system mainly consisted of ground heat exchanger, indoor heat pumps and measuring devices. The cooling and heating loads of the test room were 5.5 and 7.2 kW at design conditions, respectively. The experimental results were obtained from July 2, 2003 to July 1, 2004. The cooling and heating performance coefficients of the system were determined from the measured data. The average cooling and heating COPs for the system were obtained to be 4.90 and 3.96, respectively. The temperature variations in ground and the ground heat exchanger pipe surface at different depths were also measured.

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.172.2-172.2
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• 2010

This study was carried out in order to reduce the installation expense of heating system for greenhouse comparing to geothermal heat pump and develope the coefficient of performance (COP) for a heat pump. For getting plenty of heat flux from geothermal energy. Surface water in river channel was used for getting a lots of geothermal heat by penetrating water through underground soil layer of the river bank that make heat transmission to passing water. The range of water temperature after the process of Ground filtration is 13~18 degrees celsius which is very similar to low heat source of geothermal heat pump system and the plenty amount of heat source from that make the number of geothermal heat exchanging hole and the expense for geothermal heat exchanger construction reduced. Drainage well is also used for returning filtration water to the aquifer that keep the water good recirculation from losing geothermal heat and water resource. For the COP improvement of Heat pump, thermal storage tank with separating insulation plate according to the temperature difference make the COP of Heat pump that is similar to thermal storage tank with diffuser. Developed thermal storage tank make construction expense cheaper than customarily used one's. and that sand filter and oxidation sand (FELOX) are going to be used for improving ground filtration water quality that make heat exchanger efficiency better. All above developed component skill are going to be set on the Ground filtration water source heat pump system and applied for medium, large scale for protected greenhouse in riverside area and on-site experiment is going to do for optimizing the heating system function and overcome the problem happening in the process of on-site application afterward.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.3 no.1
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• pp.17-22
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• 2007

The growth of domestic energy demand is rapidly increased for the industrialization and the improvement of the living standards. It is also recognised that the importance of the use of environmentally friendly energy and high efficient equipment. Ground Source heat pumps (GSHP) using earth as heat source or sink are outstanding environmentally friendly energy systems which have high thermal efficiency when compared to conventional heating and cooling system. So government employs a policy and increase investment for expanding renewable energy market volume. Especially is established a system for obligatory usage of renewable energy to achieve 5% renewable energy diffusion rate by 2011. And the market demand for the ground source heat pump is rapidly growing due to its strong advantages. However domestic situation usually have been depended on the import of ground source heat pumps. In this paper, the results of development of a ground source heat pump using refrigerant R410A are reported.