ENERGETIC AND EXERGETIC ANALYSES OF CARBON DIOXIDE TRANSCRITICAL REFRIGERATION SYSTEMS FOR HOT CLIMATES

Abstract

In the last two decades many scientific papers and reports have been published in the field of the application of the carbon dioxide as a refrigerant for refrigeration systems and heat pumps. Special attention has been paid to the transcritical cycle. However, almost no papers discussed such cycles for hot climates, i.e., when the temperature of the environment is higher than 40ºС during a long period of time. This paper deals with the energetic and exergetic evaluation of a CO2 refrigeration system operating in a transcritical cycle under hot climatic conditions. The performance and exergy efficiency of the CO2 refrigeration system depend on the operation conditions. The effect of varying these conditions is also investigated as well as the limitations associated with these conditions.

Dates

  • Submission Date2012-10-07
  • Revision Date2013-02-02
  • Acceptance Date2013-02-04
  • Online Date2013-04-13

DOI Reference

10.2298/TSCI121007026F

References

  1. ***, United Nations Environment Programme (UNEP). Montreal protocol on substances that deplete the ozone layer, 1987.
  2. Lorentzen, G., Pettersen, J., A new efficient and environmentally benign system for car air-conditioning. International J Refrigeration 16(1) (1993), pp. 4-12.
  3. Lorentzen, G., Revival of carbon dioxide as a refrigerant, International J Refrigeration 17 (1994), pp. 292-300.
  4. 15th Informatory Note on Refrigerants. Carbon Dioxide as a Refrigerant. Paris, France, 2000.
  5. Pearson, A., Carbon dioxide—new uses for an old refrigerant. Review. International J Refrigeration 28 (2005), pp. 1140-1148.
  6. Kim, M.-H., Pettersen, J., Bullard, C.W., Fundamental process and system design issues in CO2 vapor compression systems, Progress in Energy and Combustion Science, 30 (2004), pp. 119-174.
  7. Sadorsky, P., Trade and energy consumption in the Middle East. Energy Economics 33 (2011), pp. 739-749.
  8. Neksfit, P., Rekstad, H., Zakeri, G.R., Schiefloe, P.A., CO2-heat pump water heater: characteristics, system design and experimental results, International J Refrigeration 21 (3) (1998), pp. 172-179.
  9. Schmidtt, E.L., Kliicker, K., Flacke, N., Steimle, F., Applying the transcritical CO2 process to a drying heat pump, International J Refrigeration 21 (3) (1998), pp. 202-211.
  10. Neksa, P., CO2 heat pump systems, International J Refrigeration 25 (2002), pp. 421-427.
  11. Cecchinato, L., Corradi, M., Fornasieri, E., Zamboni, L., Carbon dioxide as refrigerant for tap water heat pumps: A comparison with the traditional solution, International J Refrigeration 28 (2005), pp. 1250-1258.
  12. Yokoyamaa, R., Shimizua, T., Itob, K., Takemura, K., Influence of ambient temperatures on performance of a CO2 heat pump water heating system. Energy 32 (2007), pp. 388-398.
  13. Fernandez, N., Hwang, Y., Radermacher, R., Comparison of CO2 heat pump water heater performance with baseline cycle and two high COP cycles, International J Refrigeration 33 (2010), pp. 635-644.
  14. Zhang, X.P., Fan, X.W., Wang, F.K., Shen, H.G., Theoretical and experimental studies on optimum heat rejection pressure for a CO2 heat pump system, Applied Thermal Engineering 30 (2010), pp. 2537−2544.
  15. Bilgen, E., Takahashi, H., Exergy analysis and experimental study of heat pump systems, International J Exergy 2 (4) (2002), pp. 259-265.
  16. Tao, Y.B., He, Y.L., Tao, W.Q., Exergetic analysis of transcritical CO2 residential air-conditioning system based on experimental data, Applied Energy, 87 (10) (2010), pp. 3065-3072.
  17. Srinivasan, K., Lim, Y.K., Ho, J.C., Wijeysundera, N.E., Exergetic Analysis of carbon dioxide vapour compression refrigeration cycle using the new fundamental equation of state, Applied Energy 44 (20) (2003), pp. 3267-3278.
  18. Fartaj, A., Ting, D.S.-K., Yang, W.W., Second law analysis of the transcritical CO2 refrigeration cycle, Energy Conversion & Management 45 (2004), pp. 2269-2281.
  19. Sarkar, J., Bhattacharyya, S., Gopal, M.R., Transcritical CO2 heat pump systems: exergy analysis including heat transfer and fluid flow effects, Energy Conversion & Management 46 (2005), pp. 2053−2067.
  20. Kotas, T.J., The Exergy Method of Thermal Plant Analysis, Florida, USA: Krieger Publishing Company, Malabar, 1985.
  21. Kauf, F., Determination of the optimum high pressure for transcritical CO2-refrigeration cycles, International J Thermal Sciences 38(4) (1999), pp. 325-330.
  22. Rozhentsev, A., Wang, C.-C., Some design feature of a CO2 air conditioner, Applied Thermal Engineering, 21 (2001), pp. 871-880.
  23. Bock, www.bock.com
  24. Bitzer, www.bitzer.de
  25. Adson − Engineering Corporation, www.adsoncompressors.com
  26. Cool Pack. Version 1.46. Department of Mechanical Engineering, University of Denmark, www.et.dtu.dk/coolpack.
  27. Bejan, A., Tsatsaronis, G., Moran, M., Thermal Design and Optimization, New York: John Wiley and Sons, 1996.
  28. Tsatsaronis, G., Definitions and nomenclature in exergy analysis and exergoeconomics, Energy 32 (2007), pp. 249−253.
  29. Tsatsaronis, G., Recent developments in exergy analysis and exergoeconomics, International J Exergy 5 (5/6) (2008), pp. 489-499.
  30. Morosuk, T., Tsatsaronis, G. ,Advanced Exergetic Evaluation of Refrigeration Machines Using Different Working Fluids, Energy 34(2009), pp. 2248-2258.