Journal of the Korea Academia-Industrial cooperation Society (한국산학기술학회논문지)

The Korea Academia-Industrial cooperation Society (한국산학기술학회)
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Performance Comparison of Fin-Tube Type Evaporator using R134a and R1234yf under the Frost Condition

착상조건에서 R134a와 R1234yf를 적용한 핀-관 형태의 증발기 성능 비교

  • Shin, Yunchan (Graduate school of Mechanical engineering, Chosun University) ;
  • Kim, Jinhyun (Department of Automobiles, Chosun College University of Science & Technology) ;
  • Cho, Honghuyn (Department of Mechanical engineering, Chosun University)
  • 신윤찬 (조선대학교 기계공학과 대학원) ;
  • 김진현 (조선이공대학교 자동차과) ;
  • 조홍현 (조선대학교 기계공학과)
  • Received : 2015.06.03
  • Accepted : 2015.09.11
  • Published : 2015.09.30
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Abstract

The low temperature distribution of the refrigerated and frozen food has been increased gradually. Refrigeration industry is using R134a refrigerant, which GWP is 1300. R1234yf is an alternative refrigerant of R134a because GWP of R1234yf refrigerant is just 4. Evaporator used in refrigeration truck refrigeration system is operated on low temperature condition. Accordingly, evaporator is formed frost and the formation of frost is rapidly decreased performance of evaporator. In this study, the performance of evaporator using R134a and R1234yf refrigerant was analyzed with operating conditions under frost condition. As a result, the performance of R134a evaporator according to air inlet temperature, relative humidity and evaporating temperature was more sensitive than R1234yf evaporator. Besides, the frost growth of R134a evaporator is steeper than that of R1234yf one.

식생활의 향상 및 다양화로 신선한 제품에 대한 요구가 증가하고 있으며, 이에 따라 냉장 및 냉동식품의 저온유통 또한 점차 증가되고 있다. 현재 냉동산업에는 주로 R134a 냉매가 사용되고 있으며 GWP(Global Warming Potential)가 1300으로써 매우 높아 지구온난화에 영향을 미친다. 이를 대체하기 위한 냉매로써 R1234yf 냉매가 있으며, GWP는 4로써 매우 낮다. 냉동탑차 냉장시스템에 사용되는 증발기는 저온조건에서 작동되기 때문에 서리가 형성되어 시스템의 성능을 급격히 감소시킨다. 따라서, 본 연구에서 R134a와 R1234yf 냉매를 작동유체로 사용한 증발기의 성능을 착상조건 하에서 다양한 운전조건으로 분석하였다. 해석결과, 서리성장 조건에서 공기측 입구온도, 상대습도, 증발온도 변화에 대하여 R134a 증발기의 성능이 R1234yf 증발기보다 더욱 민감하게 나타났으며 서리의 성장 또한 R134a 증발기가 더 크게 나타났다.

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References

  1. J, P. Won, UNFCCC Alternative Refrigerant Automotive Air-conditioning System Technology Trends, Magazine of the SAREK, Vol. 39, No. 2, pp. 10-16, 2010.
  2. S. H. Kim, H. H. Cho, Performance Comparison between R404A and R744 Refrigeration System in Refrigerating Conditions, SAREK Conference, pp. 199-202, 2012.
  3. J. S. Lee, J. S. Han, M. R. Lee, S. M. Jeon, Performance evaluation of HFO-1234yf as a substitute for R-134a in a Household Freezer/Refrigerator, Korean Society of Mechanical Engineers B, Vol. 35, No. 7, pp. 743-748, 2011. DOI: http://dx.doi.org/10.3795/KSME-B.2011.35.7.743
  4. H. H. Cho, H. S. Lee, C. S. Park, Study on the performance improvement for an automobile air-conditioning system using alternative refrigerant R1234yf, Korean Journal of Air-conditioning and Refrigeration Engineering, Vol. 25, No. 4, pp. 201-207, 2013. DOI: http://dx.doi.org/10.6110/KJACR.2013.25.4.201
  5. H. Chen, L. Thomas, R. Besant, Modeling frost characteristics on heat exchanger fins: Part II, Model validation and limitations ASRAE Trans., pp.368-376, 2000.
  6. C. P. Tso, Y. C. Cheng, A. C. K. Lai, An improved model for predicting performance of finned tube heat exchanger under frosting condition with frost thickness variation along fin, Int. J. of Applied Thermal Engineering, Vol. 26, pp. 111-120, 2006. DOI: http://dx.doi.org/10.1016/j.applthermaleng.2005.04.009
  7. H. W. Schneider, Equation of the growth rate of frost forming on cooled surfaces, Int. J. Heat Mass Transfer, Vol. 21, pp. 1019-1024, 1978. DOI: http://dx.doi.org/10.1016/0017-9310(78)90098-4
  8. C. J. Cremers and V. K. Mehra, Frost formation on vertical cylinders in free convection, ASME J. Heat Transfer, Vol. 104, No. 1, pp. 3-7, 1980. DOI: http://dx.doi.org/10.1115/1.3245065
  9. J. Chi, A computer Model HTPUMP for Simulation of Heat Pump Steady state Performance, NBS, Washington D.C, 1979.
  10. P. A. Domanski, EVSIM: An Evaporator Simulation Model Accounting for Refrigerant and One Dimensional Air Distribution, NISTIR 89-4133, NIST, Washington D.C, 1989,.
  11. F. W. Dittus, L. M. K. Boelter, Public Eng. 2, University of California, Berkeley, 1930.
  12. B. Pierre, Flow resistance with boiling refrigerants-part1, ASHRAE Journal, pp. 58-65, 1964.
  13. K. E. Gungor, R. H. S. Winterton, A general correlation for boiling in tubes and annuli, International Journal of Heat Transfer, Vol. 19, pp. 351-358, 1986. DOI: http://dx.doi.org/10.1016/0017-9310(86)90205-X
  14. C. C. Wang, K. Y. Chi, C. J. Chang, Heat transfer and friction characteristics of plain fin-and-tube heat exchanger, part II: Correlation, Vol. 43, pp. 2693-2700, 2000. DOI: http://dx.doi.org/10.1016/s0017-9310(99)00333-6
  15. K. S. Lee, J. S. Kim, D. K. Yang, Dimensionless correlations of frost properties on a cold cylinder surface, International Journal of Heat and Mass Transfer, Vol. 51, pp. 3946-3952, 2008. DOI: http://dx.doi.org/10.1016/j.ijheatmasstransfer.2008.01.007
  16. ISO 15502, Household refrigerating appliances - Characteristics and test methods, International Organization for Standardization, Geneva, Switzerland, 2005.
  17. K. M. Lee, D. R. Kim, K. S. Lee, Local frosting behavior of a plate-fin and tube heat exchanger according to the refrigerant flow direction and surface treatment. International Journal of Heat and Mass Transfer, Vol. 64. pp. 751-758, 2013. DOI: http://dx.doi.org/10.1016/j.ijheatmasstransfer.2013.05.027