Journal of the Korean Society for Geothermal and Hydrothermal Energy (한국지열·수열에너지학회논문집)

Korean Society for Geothermal and Hydrothermal Energy (한국지열·수열에너지학회)
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Influence of Low Stage Refrigerant Charge Amount on the Performance of Cascade Heat Pump

캐스케이드 열펌프의 저단 사이클 충전량 변화에 따른 성능 특성

  • Park, Seung Byung (Graduate School of Mechanical Engineering, Hanbant National University) ;
  • Choi, Jong Min (Department of Mechanical Engineering, Hanbant National University)
  • 박승병 (한밭대학교 기계공학과 대학원) ;
  • 최종민 (한밭대학교 기계공학과)
  • Received : 2015.01.27
  • Accepted : 2015.02.24
  • Published : 2015.03.01
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Abstract

In this study, the optimization and performance characteristics of a cascade heat pump system was analyzed with the variation of low stage refrigerant charge amount. The cascade heat pump was designed and constructed with R134a and R410A as the refrigerant for high stage and low stage cycle, respectively. Experiments were conducted by varying the low stage charge amount and the performance characteristics of the cascade heat pump were studied. The refrigerant charge amount of the low stage cycle was varied between the ranges of -15% and +10% of the optimum charge amount. The performance variation experienced in the cascade heat pump due to the variation of refrigerant charge amount shows greater effect in the undercharge regions than the overcharge regions. COP reduction in the undercharge region is larger than the decrease in the overcharge region. Some cycle variation such as power consumption and cycle pressure according to low stage refrigerant charge amount showed different trends comparing with those according to high stage refrrgerant charge amount. Therefore, the optimum charge amount of the cascade heat pump should be determined based on the experimental data obtained by the variation of high and low stage refrigerant charge amount.

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References

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