Effects on Performance of an Internal Heat Exchanger According to Charge Amount and Operating Condition in $CO_2$ Cooling Mode

이산화탄소 냉방운전 시 냉매충전량 및 운전조건에 따라 내부열교환기가 성능에 미치는 영향

  • 곽명석 (조선대학교 기계공학과 대학원) ;
  • 조홍현 (조선대학교 기계공학과)
  • Received : 2012.01.11
  • Accepted : 2012.02.03
  • Published : 2012.03.01


This is an experimental study on the performance characteristics of effective heat pump in the cooling mode using a single-stage compression $CO_2$ cycle with an IHX(internal heat exchanger). The performance of a single-stage compression with IHX was investigated according to charge amount and operating condition. Moreover, the performance characteristic of cooling operating was analyzed with the length of IHX. As a result, the optimum refrigerant charge amount was 2.2 kg. The optimal system COP for compressor frequency of 30, 40, 50, and 60 Hz was 3.493, 3.228, 2.978, and 2.659, respectively. Since the system with IHX can maintain large cooling capacity regardless of operating condition, the system performance doesn't reduce considerably under unfavorable condition. When the compressor frequency was 40 Hz, the COP for a system with IHX length of 3 m and 5 m was 3.361 and 3.51, respectively. By using the IHX into a $CO_2$ cooling system, the performance and reliability improves simultaneously.



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