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Analysis of Heat Transfer Performance of a Gas Cooler of CO2 Heat Pump for Water Heating

온수제조용 CO2 히트펌프의 가스쿨러 열전달 성능 해석

  • Received : 2012.09.11
  • Accepted : 2013.11.07
  • Published : 2013.11.30

Abstract

This study presents a prediction method for heat transfer performance of a gas cooler of $CO_2$ heat pump using ${\epsilon}$-NTU method, and compared the results with the experimental data from the open literature. The heat transfer rate, refrigerant side outlet temperature and water side outlet temperature were calculated by using EES(Engineering Equation Solver)program in multi-tube-in-tube type $CO_2$ heat pump gas cooler. Analysis was performed in two methods : The first method performed without dividing into the test section by applying an analysis of the mean properties(mean analysis). The second method, tube length divided into 50 sections, was applied to the local properties(local analysis). From the present study, a good agreement at the local analysis was obtained between the analytical and experimental results by 0.3~1.1%, 1.31~1.88% and 3.12~5.18% for heat transfer rate, water and refrigerant side outlet temperatures, respectively.

본 연구에서는 ${\epsilon}$-NTU 방법을 사용하여 $CO_2$ 히트펌프 가스쿨러의 열전달 성능을 해석하였고, 공개된 실험결과와 비교하였다. $CO_2$ 히트펌프 가스쿨러의 열전달률, 냉매측/순환수측 출구온도를 EES로 계산하였다. 해석은 시험부를 하나의 구간으로 설정하여 냉매와 순환수측 입출구의 평균온도를 물성치로 적용한 평균해석과 시험부를 50구간으로 나누어 각 구간에서의 출구온도를 다음 구간의 입구온도로 사용한 국소해석으로 진행되었다. 실험결과로부터 평균해석보다는 국소해석의 결과가 실험값을 더 만족하였으며, 열전달률은 0.3~1.1%, 순환수측 출구온도는 1.31~1.88%, 냉매측 출구온도는 3.12~5.18% 정도의 오차를 보였다.

Keywords

References

  1. Y. C. Kwon, D. H. Kim, S. J. Lee, J. Y. Choi, J. H. Lee, "Study on Heat Transfer and Pressure Drop Characteristics of Internal Heat Exchanger for $CO_2$ Heat Pump under Cooling Condition", Korean Journal of Air-Conditioning and Refrigeration Engineering Vol. 20, No.8, pp.517-525, 2008.
  2. Y. C. Kwon, S. J. Lee, J. Y. Choi, J. H. Lee, "Experimental Study on Evaporation Heat Transfer and Oil Effect in Micro-fin Tube Using $CO_2$.", Korean Journal of Air-Conditioning and Refrigeration Engineering Vol. 20, No.2, pp.106-112, 2008.
  3. M. H. Kim, "Overview of Development Trend in Japan at $CO_2$ Heat Pump for Water Heating", Journal of the KSME, Vol. 31 No. 7, pp. 65-70, 2007.
  4. P. Neksa, H. Rekstad, G. R. Zakeri and P. A. Schiefloe., "$CO_2$-heat pump water heater: characteristics, system design and experimental results", Int. Journal of Refrigeration, Vol. 21, No. 3, pp. 172-179, 1998. DOI: http://dx.doi.org/10.1016/S0140-7007(98)00017-6
  5. Y. R. Kim, "Design and Performance Test of the Heat Exchanger for Water-heating for Cooling/Heating /water-heating System Using $CO_2$", 2nd Report of Ministry of Knowledge Economy, p.74-95, 2007.
  6. H. K Oh, C. H Son, "Experimental Study on Compact type $CO_2$ Gas Cooler(2)", Journal of the Korean Society of Marine Engineering Vol. 34, No.1, pp.30-36, 2010. DOI: http://dx.doi.org/10.5916/jkosme.2010.34.1.030
  7. H. K Oh, C. H Son, "Experimental Study on Compact type $CO_2$ Gas Cooler(1)", Journal of the Korean Society of Marine Engineering Vol. 34, No.2, pp.259-266, 2010. DOI: http://dx.doi.org/10.5916/jkosme.2010.34.2.259

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