• Title/Summary/Keyword: Heat pump

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The Performance Improvement of a Gas Injection Heat Pump with a Flash Tank (기액분리기를 적용한 가스 인젝션 히트펌프의 성능 향상에 관한 실험적 연구)

  • Son, Kilsoo;Kim, Dongwoo;Choi, Sungkyung;Kim, Yongchan
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.29 no.6
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    • pp.297-305
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    • 2017
  • Air-source heat pumps are widely used in residential heating systems. However, the decrease in the capacity of the heat pump is unavoidable when operating at very low and high ambient temperatures. The vapor injection technique is considered a promising technology to overcome this problem. Recent research on vapor injection cycles have mainly adopted a scroll compressor with an internal heat exchanger at severe operating conditions. This study measured the COP and EER of a gas injection heat pump using a flash tank with an inverter-driven rotary compressor at severe operating conditions. Compared to non-injection heat pumps, the heating capacity and COP of the gas injection heat pump improved up to 15% and 2.9%, respectively, at outdoor temperatures of $-10^{\circ}C$ to $7^{\circ}C$. The cooling capacity of the gas injection heat pump was 11% higher than the non-injection heat pump at an outdoor temperature of $35^{\circ}C$. At the same time, the EER of the gas injection heat pump was similar to that of the non-injection heat pump.

A Study of Storage Type Cooling and Heating System by Heat Pipe (히트파이프를 이용한 축열식 냉.난방 시스템에 관한 연구)

  • Kim, Seong-Sil;Harm, Seong-Chol;Lee, Yang-Ho;Choi, Byoung-Youn
    • Proceedings of the SAREK Conference
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    • 2006.06a
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    • pp.3-8
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    • 2006
  • The heat pump system is attractive alternatives to conventional heating and cooling systems owing to their higher energy utilization efficiency. The thermal loads of commercial and institutional buildings are generally cooling-dominated. In this study have been developed ice storage type heat pump system for cooling and heating by heat pipe. This system was practiced performance test on evaluation criteria for heat storage systems. Accomplished the actual proof examination and looked into the performance of the system. In this study, measurement and analysis of ice storage type heat pump system for cooling and heating by heat pipe. The heat pump unit COP appears 3.05 for cooling and 4.20 for heating. As a result, the method to energy saving and to using a substitute energy actively that is heat pump cooling & heating system is expected by heat pipe. Thermal storage capacity appears $19.5RTH/m^3$ for cooling.

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Analysis of Thermal Performance of Ground-Source Heat Pump System (지열 이용 히트펌프 시스템의 열성능 해석)

  • Shin, U-Cheul;Baek, Nam-Choon;Kim, Ook-Joong;Koh, Deuk-Yong
    • 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.

Performance Analysis of an Earth Coupled Heat Pump System Operated by an Engine(II) - Performance Analysis of a Vapour Compression type Compact Heat Pump - (엔진구동 지열 열펌프의 성능 분석(II) - 소형 증기압축식 열펌프의 성능 분석 -)

  • 김영복;송대빈;손재길
    • Journal of Biosystems Engineering
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    • v.24 no.6
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    • pp.501-512
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    • 1999
  • In this study, the coefficient of performance of a vapour compression heat pump system was analyzed for the evaluation of the heat pump performance. A water-to-air heat pump was assembled and tested by changing the level of the compressor driving speed and the air mass flow rate during air heating process. The coefficient of performance for air heating was 2.6~3.8 and that for water cooling was 1.0~1.4. The coefficient of performance was not depending on the levels of the compressor driving speed or levels of the air mass flow rate, but on the temperature of the air and water. The coefficient of performance for air heating increased by about 0.2 with the water temperature increasing by 1$^{\circ}C$.

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Optimization of Heat Pump Systems (열펌프의 성능 최적화에 관한 연구)

  • Choi, Jong-Min;Yun, Rin;Kim, Yong-Chan
    • 한국신재생에너지학회:학술대회논문집
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    • 2007.11a
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    • pp.538-541
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    • 2007
  • An expansion device plays an important role in optimizing the heat pumps by controlling refrigerant flow and balancing the system pressures. Conventional expansion devices are being gradually replaced with electronic expansion valves due to increasing focus on comfort, energy conservation, and application of a variable speed compressor. In addition, the amount of refrigerant charge in a heat pump is another primary parameter influencing system performance. In this study, the flow characteristics of the expansion devices are analyzed, and the effects of refrigerant charge amount on the performance of the heat pump are investigated at various operating conditions. Cooling capacity of the heat pump system is strongly dependent on load conditions. The heat pump system is very sensitive with a variation of refrigerant charge amount. But, the performance of it can be optimized by adjusting the flow rate through expansion device to maintain a constant superheat at all test conditions.

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Drying Performance Simulation for the Basic Design of a Heat Pump Dryer (열펌프 건조기의 기본 설계를 위한 건조 성능 해석)

  • Lee, Kong-Roon;Kim, Ook-Joong
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.31 no.10
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    • pp.860-867
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    • 2007
  • Heat pump drying has a great potential for energy saving due to its high energy efficiency in comparison with conventional air drying. In the present study, the performance simulation for the basic design of a heat pump dryer has been carried out. The simulation includes one-stage heat pump cycle, simple drying process using the drying efficiency. As an example, the heat pump cycle with Refrigerant 134a has been investigated. For the operating conditions such as the average temperature of the condenser, the heat rate released in the condenser, the flow rate of drying air, and drying efficiency, the simulation has been carried out to figure out the performance of the dryer. The parameters considered in the design of the dryer are COP, MER, SMER, the rate of dehumidification, the temperature and humidity of drying air and those parameters are compared for different conditions after carrying out the simulation.

Performance Analysis of Heat Pump System for Greenhouse Cooling (온실 냉방을 위한 히트펌프의 성능 분석)

  • 윤용철;서원명;이석건
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.43 no.6
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    • pp.120-126
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    • 2001
  • This experiment was carried out to analyse on the cooling and dehumidifying effects of greenhouse by air-to-water heat pump system employing the air as cooling source. following results were obtained ; 1. The coefficients of performance (COP) of heat pump itself and total heat pump system were approximately 2.71~2.88 and 1.99~2.22, respectively. 2. The night-time cooling load of experimental greenhouse was 64.9 MJ/h, and the heat absorbed (cooling load) from heat pump system was 816.3~1,004.6 MJ/day. 3. The dehumidified moisture amount from experimental greenhouse was 7.0~15.0 kg/h. 4. The night time temperature of experimental greenhouse cooled by heat pump system could be maintained 4~6$^{\circ}C$ lower than that of control greenhouse which was almost equal to outside air temperature.

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Analysis of Thermal Performance of Ground-Source Heat Pump System (지열 이용 열펌프 시스템의 열성능 해석)

  • Koh, Deuk-Yong;Shin, U-Cheul;Baek, Nam-Choon;Kim, Ook-Joong
    • 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.

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On-site Performance Test and Simulation of a 10 RT Air Source Heat Pump

  • Baik, Young-Jin;Chang, Young-Soo;Kim, Young-Il
    • International Journal of Air-Conditioning and Refrigeration
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    • v.12 no.2
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    • pp.61-69
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    • 2004
  • In this study, on-site performance test of an air source heat pump which has a rated capacity of 10 RT is carried out. Since indoor and outdoor air conditions can not be controlled to satisfy the standard test conditions, experiments are done with the inlet air conditions as they exist. To estimate the performance of the heat pump for other conditions, the heat pump is modeled with a small number of characteristic parameters. The values of the parameters are determined from the few measurements measured on-site during steady operation. A simulation program is developed to calculate cooling capacity and power consumption at any other arbitrary operating conditions. The simulation results are in good agreement with the experiment. This study provides a method of an on-site performance diagnosis of an air source heat pump.

An Experimental Study on the Energy Efficiency Ratio of Heat Pump for Air Source (공기열원 히트펌프의 에너지 효율 비율에 관한 실험적 연구)

  • SOON YOUNG JEONG
    • Transactions of the Korean hydrogen and new energy society
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    • v.33 no.6
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    • pp.838-844
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    • 2022
  • In this paper, an experimental study was conducted on the energy efficiency ratio of performance for air source heat pump. The energy efficiency ratio presents the operating efficiency of heat pump performance. In order to improve reliability in the energy efficiency ratio test of air source heat pump, the measurement uncertainty of the instrument was estimated. Measurement uncertainty refers to the uncertainty of a measurement, estimates the range in which the expected value of the measurement can be within a certain confidence level, and suggests a range in which the measured representative value is incorrect. The measurement uncertainty for the energy efficiency ratio test of air source heat pump was calculated and the measured results were presented.