• Title/Summary/Keyword: Heat pump system

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Experimental Study for Horizontal Geothermal Heat Pump Heating Performance Analysis (수평형 지열 히트펌프 난방 성능 분석을 위한 실험적 연구)

  • Ihm, Pyeong chan;Cho, Sung woo
    • Journal of the Korean Society for Geothermal and Hydrothermal Energy
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    • v.12 no.2
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    • pp.7-12
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    • 2016
  • This study have an objective to suggest basic data and measured result of heating performance on water-water type horizontal geothermal heat pump which is based on heating and cooling load calculation result of small residential house. The average temperature during measured periods is $9.4^{\circ}C$ on primary EWT and is $7.6^{\circ}C$ on primary LWT. The temperature difference shows $1.8^{\circ}C$ as average temperature. Because the average outdoor temperature of peak is lager than on December and than on January, the temperature difference between EWT and LWT is bigger that on January than that on December. The system COP is 3.62.

Performance of the Flow Distribution and Capacity Modulation of a Multi-Heat Pump System (멀티형 열펌프의 유량분배 및 용량조절 특성)

  • 최종민;김용찬;하진호
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.13 no.5
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    • pp.313-320
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    • 2001
  • In the present study, various experiments were performed to investigate capacity modulation and refrigerant flow distribution of a multi-heat pump using a variable speed compressor and electronic expansion valves(EEVs) in the cooling mode. Based on the experimental results, it was possible to understand the interrelation of dual indoor units which provides some difficulties in capacity control of each indoor unit. The characteristics of capacity modulation of two indoor units were measured by controlling two EEVs with a cooling load of each indoor unit.

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Experimental study on characteristics of two-phase flow through a bypass-orifice expansion device (바이패스 오리피스 팽창장치의 유동 특성에 관한 실험적 연구)

  • Choi, J.M.;Kim, Y.C.
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.11 no.1
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    • pp.109-116
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    • 1999
  • To establish optimum cycle of the inverter-driven heat pump with a variation of frequency, the bypass orifice, which is a short tube having a bypass hole in the middle, was designed and tested. Flow characteristics of the bypass orifice were measured as a function of orifice geometry and operating conditions. Flow trends with respect to frequency were compared with those of short tube orifices and capillary tubes. Generally, the bypass orifice showed the best flow trends among them, that will enhance the seasonal energy efficiency ratio of an inverter heat pump system. Based on experimental data, the semi-empirical flow model was developed to predict mass flow rate through bypass orifices. The maximum difference between measured data and model's prediction was within ${\pm}5%$.

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Experimental and Theoretical Studies on the Dynamic Characteristics During Speed Down of Inverter Heat Pump

  • Hwang, Yoon-Jei;Kim, Ho-Young
    • International Journal of Air-Conditioning and Refrigeration
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    • v.8 no.1
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    • pp.29-39
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    • 2000
  • A series of tests were performed to verify the transient characteristics of heat pump in heating and cooling mode when operating speed was varied over the 30 to 102Hz. One of the major issues that has not been addressed so far is transient characteristics during speed modulation. The model for cycle simulation has been developed to predict the cycle performance under conditions of decreasing drive frequency and the results of the theoretical study were compared with the results of the experimental study. The simulated results were in good agreement with the experimental result within 10%. The transient cycle migration of the liquid state refrigerant causes significant dynamic change in system. Thus, the migration of refrigerant was the most important factor whenever do experimental results analysis or develop simulation model.

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Analysis of Electric Substitution Effects by the Gas Consumption and Characteristics of Gas Cooling System (냉방기기 사용량과 특성을 고려한 가스냉방기기의 전력대체 효과 분석)

  • Park, Rae-Jun;Song, Kyung-Bin
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.61 no.5
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    • pp.669-675
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    • 2012
  • Recently, the amount of electrical heat pump(EHP), a electrical conditioning equipment, is sharply increasing due to the luxury and multi-story trend of building. Accordingly, the cooling load that occupying substantial part of summer electric consumption has increased dramatically, making difficulties in domestic supply of electricity in summer. There are some efforts to replace it with an alternative cooling equipment such as gas heat pump(GHP), a gas cooling equipment, in order to solve the problem of summer electricity supply through reducing the summer electricity peak. It is rare, however, to find studies on the actual effects of GHP on the reduction of summer electricity peak. This study, therefore, estimated the effects of the GHP on the summer electricity peak by the gas consumption and characteristics of gas cooling systems. In addition, electric substitution effects by gas cooling systems were analyzed through case studies in the summer of 2010.

PERFORMANCE EVALUATION OF BUBBLE PUMP USED IN A PASSIVE SOLAR WATER HEATER SYSTEM

  • Xuesong, Li;Park, Gi-Tae;Chung, Han-Shik;Jeong, Hyo-Min
    • Proceedings of the KSME Conference
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    • 2007.05b
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    • pp.2309-2314
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    • 2007
  • The application analysis of bubble pump on the domestic solar water heater system is presented. The system investigated in this study is a passive device, self pumping and self regulating. It was test to use the bubble pump on solar water heater system. The test experiment has been taken on the existed vacuum tube about the efficiency, working fluid temperature and pressure and circulated power. In order to check the working temperature and working pressure effectively, the bubble pump was test separated from the solar water heater. The equipment consists of the bubble pump, heater and heat exchanger. The main structure of bubble pump was design depend on the character of two phase flow. The complete system was instrumented to measure pressures, temperatures and flow-rates at various locations. The theory analysis of design bubble pump has been given and the experiment design has been included in the paper.

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Analysis of Thermodynamic Design Data for Heating of Double - Effect Solar Absorption System using LiBr - water and Ethylene Glycol Mixture (에틸렌글리콜 혼합액을 사용하고, 태양열을 보조열원으로 하는 이중효용 흡수식 시스템의 난방 특성해석)

  • Won, S.H.
    • Journal of the Korean Solar Energy Society
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    • v.22 no.4
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    • pp.51-61
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    • 2002
  • Analysis of thermodynamic design data of double effect solar absorption heat pump system for heating has been done to find the property of Libr-water + ethylene Glycol mixture for working fluid by computer simulation. Derived thermodynamic design data. enthalpy based coefficient of performance and flow ratio for possible combinations of operating temperature for water - LiBr and Ethylene Glycol mixture (H2O: CHO ratio 10:1 by mole) by computer simulation. The obtained results, COP and mass flow ratio of the water-lithium bromide-ethylene glycol system, are compared with data for the water-Libr pair solution.

Pre-Analysis Study on Ground Source Heat Pump System in Building with RETScreen (RETScreen을 활용한 건물에서의 지열 히트펌프 시스템 적용 사전 분석연구)

  • Kim, Yu Jin;Lee, Kwang-Seob;Lee, Euy-Joon;Kang, Eun-Chul
    • Journal of the Korean Solar Energy Society
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    • v.40 no.2
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    • pp.1-10
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    • 2020
  • Korea government published renewable energy obligation policy that public building must be supplied some part of total consumption energy (2019: 27%, 2020: 30%). RETScreen is freely available global energy tool that developed by Canadian National Energy Laboratory to quantify energy saving to compare conventional system. This program can be performed energy modeling, cost analysis, greenhouse gas emission analysis and financial analysis. In this study, GSHP (Ground source heat pump) heating and cooling system were studied for the energy deliverly and ROI (Return On Investment) in an office building. Three cases were studied according to the number of HP (Heat pump) units for the 1,000㎡ office building located in Daejeon. Results indicated that the energy delivery of the case 1 (1 HP unit) covered 57% of the office building heating and cooling energy consumption. The case 2 (2 HP units) covered 87.8% and the case 3 (3 HP units) covered 96.8% of the office building energy consumption. The ROI of the case 1 indicated 7.9 years. While 8.2 years for the case 2 and 9.7 years for the case 3.