• Title/Summary/Keyword: 2단압축열펌프

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An Experimental Study on the Part-Load Performance of a River Water Source 2-Stage Heat Pump (하천수 열원 2단 압축 열펌프시스템의 부분부하 운전특성에 관한 실험적 연구)

  • Kim, Ji-Young;Baik, Young-Jin;Lee, Young-Soo;Ra, Ho-Sang
    • Proceedings of the KSME Conference
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    • 2007.05b
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    • pp.1964-1968
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    • 2007
  • The river water heat source heat pump has the advantage in the performance compared to air source heat pump. Although its better performance, the large temperature difference between load and source makes system performance worse by nature. In this study, 2-stage compression is considered as the solution of this problem. Generally, heat pump is designed for maximum capacity rate, but it actually operates at part load condition in many cases. Therefore, an information on the part-load character is very important in view of the system overall performance. In this study, part-load performance tests of a R134a 2-stage compression heat pump were carried out over the river water and supply heating water temperature changes. The experimental results show that the system performance is influenced by the part load rates, river water temperature, load temperature, etc.

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A study on the part-load performance of 2-stage water source heat pump (2단 압축 수열원 열펌프 시스템의 부분부하 운전특성에 관한 연구)

  • Lee, Young-Soo;Baik, Young-Jin
    • Journal of the Korean Society for Geothermal and Hydrothermal Energy
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    • v.5 no.1
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    • pp.13-17
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    • 2009
  • The river water heat source heat pump has the advantage in the performance compared to air source heat pump. In this study, an experimental study on a 2-stage heat pump, which is designed to utilize a river water heat source, were carried out. Generally, a heat pump is designed for maximum capacity rate, but it actually operates at part load condition in most cases. Therefore, an information on the part-load characteristic is very important in view of the system overall performance. In this study, part-load performance tests of a R134a 2-stage compression heat pump were carried out over the river water and supply heating water temperature changes.

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A Study on the Operating Control of a Heat Pump System with Screw Compressors (스크류 열펌프 시스템의 운전제어 방안에 관한 연구)

  • Park, Jun-Tark;Lee, Young-Soo;Kim, Jiyoung;Chae, Kyu-Jung;Yang, Hee-Jung
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.25 no.3
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    • pp.168-172
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    • 2013
  • A preliminary performance test of a 30RT 2-stage screw heat pump was carried out in order to develop a high performance large-scale unutilized energy source heat pump system, which will be used for district heating and cooling. In this study, two issues of the system operating control were investigated. The first issue is the mode switching control from 1-stage to 2-stage. A stable 2-stage heating operation is guaranteed, only if the load-side water inlet temperature is over a certain value, where the 1-stage heating operation should be done first from a cold start. The second issue is oil level control. An oil shortage problem in the low stage compressor, which depends on the degree of suction superheat, was solved by a proper oil level control scheme.

Performance Analysis and Prior-Treatment of Heat Pump System with Low-Temperature Water Heat Source (저온수열원이용 열펌프시스템의 전처리 및 성능분석)

  • Park, Seong-Ryong;Chang, Ki-Chang;Lee, Sang-Nam;Ra, Ho-Sang;Park, Jun-Tack
    • Proceedings of the KSME Conference
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    • 2000.04b
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    • pp.258-263
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    • 2000
  • River water is higher in temperature than the surrounding environment during the winter. It is highly suitable a heat source for heat pump system. Despite its suitability, however, it is not widely used, due to its fouling and corrosive nature in heat exchanger tubes of evaporator. It is designed prior-treatment system which come into direct contact with the river water, such as auto-seamer, ozone generator for bactericidal test and auto-cleaning system. And it is analyzed treatment effects for its operation. It is designed two-stage compression heat pump system using R-134a with heating load 35.16kW, ad analyzed its performance. As a result it is obtained 3.08 COP when mid-point pressure is 1,200kPa, and bypass ratio of flowing refreigerant to high-stage compressor is 25.1%

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A Study on The Operation Characteristics of 2-Stage Compression Heat Pump using Treated sewage (하수처리수를 이용한 2단 압축 열펌프 시스템의 운전특성에 관한 연구)

  • Kim, Ji-Young;Baik, Young-Jin;Lee, Young-Soo;Chang, Ki-Chang;Ra, Ho-sang
    • Proceedings of the SAREK Conference
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    • 2008.06a
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    • pp.299-303
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    • 2008
  • The treated sewage temperature is about $5^{\circ}C$ lower in summer and $5{\sim}10^{\circ}C$ higher in winter than ambient air. It can be used heat pump heat source and is good heat source on high performance of heat pump. In this study, to develop 100RT 2-stage compression heat pump use treated sewage water heat source and system applies to sewage disposal plant. Although heat pump is better performance, the large temperature difference between load and source makes the performance degradation of a heat pump. To solve this problem screw 2-stage compression is considered. The experiment was focused on the system operating performance variations over supply water and treated sewage water a temperature in the field. The results show that system of heating performance is higher then general heat pump and is enough to supply a hot water of $70^{\circ}C$.

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Cooling Performance Test of 2-stage Heat Pump System Using River Water as a Heat Source (하천수율원이용 2단압축 열펌프시스템 냉방성능평가)

  • Kim, J.R.;Lee, Y.S.;Jang, K.C.;Ra, H.S.
    • Proceedings of the KSME Conference
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    • 2004.04a
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    • pp.2129-2134
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    • 2004
  • The present study has been conducted to develop a heat pump system using river water of temperature energy which not only belongs to unutilized energy but is a kind of good heat source due to maintain its temperature in a certain degree regardless of seasonal variation. The system did not meet the proposed performance after setup. In this paper, the system performance affected by refrigerant Oil, by pressure drop, or by other factors has been discussed. The followings were obtained : (1) Refrigerant Oil mixture rate was 2.5 in weight percentage, (2) Pressure drop through evaporator was 29.1kPa($3.1^{\circ}C$ in saturated tempearture) (3) Pressure drop from the end of evaporator to compressor inlet was 39.8kPa($4.0^{\circ}C$ in saturated tempearture). (4) The system performance can to be improved by modifying a part of pipe line to compressor, and reducing pressure drop through heat exchangers.

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Performance and Parameter Comparison between single stage and Two-Stage Compression/Absorption Heat Pump System (단단 및 2단 압축/흡수 히트펌스시스템의 성능 및 중요인자비교 분석)

  • Tian, Huaizhang;Park, Seong-Ryong
    • Proceedings of the SAREK Conference
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    • 2005.11a
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    • pp.451-456
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    • 2005
  • The mathematical model for the heat exchangers of absorber and desorber is made in the elementary control volume method and the thermodynamic properties of working fluid. water/ammonia mixture. are calculated by some fundamental subroutines in RefProp 7.0 and flash subroutines made by authors The simulation results show that two-stage cycle has higher COP than single stage if temperature lift is high: the performance of single stage compression cycle can be improved by increase of absorber pressure. but the performance of two-stage compression cycle can not be improved in this way : the compressor discharging temperature of two-stage compression is much lower than that of single stage cycle. which is very important to the safety operation of CA heat pump. Major parameter comparison between the cycles at their optimal configurations is also given.

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