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Performance Comparison between Indirect Evaporative Cooler and Regenerative Evaporative Cooler made of Plastic/Paper

플라스틱/종이 재질의 간접 증발 소자와 재생 증발 소자 성능 비교

  • Kim, Nae-Hyun (Division of Mechanical System Engineering, Incheon National University)
  • 김내현 (인천대학교 기계시스템공학부)
  • Received : 2015.10.13
  • Accepted : 2016.01.05
  • Published : 2016.01.31

Abstract

The Korean summer is hot and humid, and air-conditioners consume considerable amounts of electricity. In such cases, the simultaneous use of indirect evaporative coolers may help reduce the sensible heat and save electricity. In this study, heat transfer and pressure drop characteristics of indirect or regenerative evaporative coolers made from plastic/paper are investigated. The results showed that heat and mass transfer model based on the ${\epsilon}-NTU$ method predicted the indirect evaporation efficiencies, cooling capacities and pressure drops adequately. Both for indirect or regenerative evaporative cooler, the indirect evaporation efficiency increased with increasing dry channel inlet temperature or relative humidity. The indirect evaporation efficiency of the regenerative evaporative cooler was larger than that of the indirect evaporative cooler.

여름철이 무더운 대한민국에서는 냉방에 많은 전력을 소비한다. 이 경우 간접증발냉각을 동시에 적용하면 전기 사용을 줄일 수 있다. 본 연구에서는 물 퍼짐성을 개선한 플라스틱/종이 재질의 간접 및 재생증발소자에 대해 일련의 실험을 수행하였다. ${\epsilon}-NTU$ 방식의 열 및 물질전달 해석 모델과 비교한 결과 모델의 예측치는 간접 및 재생증발소자의 간접증발효율, 냉각열량, 압력손실을 적절히 예측하였다. 모델 해석 결과 간접 및 재생증발소자 모두 건채널 입구온도와 상대습도가 증가하면 간접증발효율이 증가하였다. 또한 재생증발소자의 간접증발효율이 간접증발소자의 값보다 크게 나타났다.

Keywords

References

  1. Duan, Z., Zhan, C., Zhang, X., Mustafa, M. Zhao, X., Alimohammadisgvand, B. and Hasan, A., "Indirect evaporative cooling: past, present and future potentials," Renew. Sustain. Energy Rev., Vol. 16, pp. 6823-6850, 2012. DOI: http://dx.doi.org/10.1016/j.rser.2012.07.007
  2. Jaber, S. and Ajib, S., "Evaporative cooling as an efficient system in Mediterranean region," Appl. Therm. Eng., Vol. 31, pp. 2590-2596, 2011. DOI: http://dx.doi.org/10.1016/j.applthermaleng.2011.04.026
  3. Caliskan, H., Dincer, I. and Hepbasil, A., "Exergoeconomic enviroecomomic and sustainability analyses of a novel air cooler," Energy Build., Vol. 55, pp. 747-756, 2012. DOI: http://dx.doi.org/10.1016/j.enbuild.2012.03.024
  4. Costello, B. and Finn, D., "Thermal effectiveness characteristics of low approach indirect evaporative cooling systems in buildings," Energy Build., Vol. 39, pp. 1235-1243, 2007. DOI: http://dx.doi.org/10.1016/j.enbuild.2007.01.003
  5. Maheshwari, G. P., Al-Ragom, F. and Suri, R. K., "Energy saving potential of an indirect evaporative cooler," Appl. Energy, Vol. 69, pp. 69-76, 2001. DOI: http://dx.doi.org/10.1016/S0306-2619(00)00066-0
  6. Santamouris, M. and Kolokotsa, D.. "Passive cooling dissipation techniques for buildings and other structures: the state of the art," Energy Build., Vol. 57, pp. 74-94, 2013. DOI: http://dx.doi.org/10.1016/j.enbuild.2012.11.002
  7. Watt, J. D. and Brown, W. K., Evaporative Air Conditioning Handbook, 3rd ed., The Fairmont Press Inc., 1997.
  8. Pescod, D., "A heat exchanger for energy saving in an air conditioning plant," ASHRAE Trans., Vol. 85., Pt. 2, pp. 238-251, 1979.
  9. Maclaine-Cross, I. L. and Banks, P. J., "A general theory of wet surface heat exchangers and its application to regenerative cooling," J. Heat Transfer, Vol. 103, pp. 578-585, 1981. DOI: http://dx.doi.org/10.1115/1.3244505
  10. Kettleborough, C. F. and Hsieh, C. S., "The thermal performance of the wet surface plastic plate heat exchanger used in an indirect evaporative cooler," J. Heat Transfer, Vol. 105, pp. 366-373, 1983. DOI: http://dx.doi.org/10.1115/1.3245587
  11. Parker, R. O. and Treybal, R. E., "The heat mass transfer characteristics of evaporative coolers," Chem. Eng. Prog. Symp. Ser. Vol 57, No. 32, pp. 138-149, 1962.
  12. Hasan, A. an Siren, K., "Performance investigation of plain and finned tube evaporatively cooled heat exchangers," Appl. Therm. Eng., Vol. 23, No. 3, pp. 325-340, 2003. DOI: http://dx.doi.org/10.1016/S1359-4311(02)00194-1
  13. Zalewski, W. and Gryglaszewski, P. A., "Mathematical model of heat and mass transfer processes in evaporative coolers," Chem. Eng. Process, Vol. 36, No. 4, pp. 271-280, 1977. DOI: http://dx.doi.org/10.1016/S0255-2701(97)00006-8
  14. Ren, C. and Yang, H., "An analytical model for the heat and mass transfer processes in indirect evaporative cooling with parallel/counter flow configurations," Int. J. Heat Mass Transfer, Vol. 49, pp. 617-627, 2006. DOI: http://dx.doi.org/10.1016/j.ijheatmasstransfer.2005.08.019
  15. Hasan, A., "Going below the wet-bulb temperature by indirect evaporative cooling: Analysis using a modified ${\epsilon}$-NTU method," Appl. Energy, Vol. 89, pp. 237-245, 2012. DOI: http://dx.doi.org/10.1016/j.apenergy.2011.07.005
  16. Cui, X., Chua, K. J., Islam, M. R. and Yang, W. M., "Fundamental formulation of a modified LMTD method to study indirect evaporative heat exchangers," Energy Conservation Management, Vol. 88, pp. 372-381, 2014. DOI: http://dx.doi.org/10.1016/j.enconman.2014.08.056
  17. Riangvilaikul, B. and Kumar, S., "An experimental study of a novel dew point evaporative cooling system," Energy Build., Vol. 42, pp. 637-644, 2010. DOI: http://dx.doi.org/10.1016/j.enbuild.2010.07.020
  18. Zhao, X., Liu, S. and Riffat, S. B., "Comparative study of heat and mass exchanging materials for indirect evaporative cooling systems," Build. Environ., Vol. 43, No. 11, pp. 1902-1911, 2008. DOI: http://dx.doi.org/10.1016/j.buildenv.2007.11.009
  19. KS M 896, Paper and plate - Measurement of water absorption rate in water, 2013.
  20. ASHRAE Standard 41.1, Standard Method for Temperature Measurement, ASHRAE, 1986.
  21. ASHRAE Standard 41.2, "Standard Method for Laboratory Air-Flow Measurement, ASHRAE, 1987.
  22. KS C 9306, Air Conditioner, Korean Standard Association, 2010.
  23. ASHRAE Standard 143, Method of test for rating indirect evaporative coolers, ASHRAE, 2007.
  24. Klein S. J. and McClintock, F. A., "The description of uncertainties in a single sample experiments," Mech. Eng. Vol. 75, pp. 3-9, 1953.
  25. Mirth, D. R. Ramadhyani, S. and Hittle, D. C., "Thermal performance of chilled water cooling coils at low water velocities," ASHRAE Trans., Vol. 99, Pt., 1, pp. 43-53, 1993.
  26. Pirompugd, W., Wang, C. C. and Wongwises, S., "A review on reduction method for heat and mass transfer characteristics of fin-and-tube heat exchangers under dehumidifying conditions," Int. J. Heat Mass Transfer, Vol. 52, No. 9-10, pp. 2370-2378, 2009. DOI: http://dx.doi.org/10.1016/j.ijheatmasstransfer.2008.10.019
  27. Kim, N.-H., Oh, W.-K., Cho, J.-P., Park, W.-Y. and Youn, B., "Data reduction on the airside heat transfer coefficients of heat exchangers under dehumidifying conditions," Korean J. Air-Cond. Refrig., Vol. 15, No. 1, pp. 73-85, 2003.
  28. Holman, J. P., Heat Transfer, 8th ed., McGraw-Hill Pub., 2000.
  29. Shah, R. K. and London, A. L., Laminar Flow in Ducts, Academic Press, 1989.
  30. Johnson, J. E., Heat and mass transfer between two fluid streams separated by a thin permeable barrier, Ph.D Thesis, Univ. Minnesota, 1997.
  31. Kays, W. M. and London, A. L., Compact Heat Exchangers, 3rd ed., Krieger Pub., 1984.