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The performance evaluation of R744 transcritical ejector and R290/R744 cascade refrigeration systems for Turkey

ABSTRACT
In this study, performance of two different environmentally friendly systems with natural refrigerant solutions, R744 transcritical booster system with ejector and a R290/R744 cascade system are examined theoretically by using EES software. Operating conditions are determined to represent different climatic regions in Turkey using summer dry bulb temperatures of various cities. The transcritical and the cascade system are assumed to operate at two different evaporation temperatures of -10°C and -32°C. The overall Energy Efficiency Ratio (EER) values for each system with respect to the same ambient and evaporation conditions are compared and evaluated. Finally, performance of both systems has been compared and the appropriate solution for each city has been suggested. For cold and mild climate regions of Turkey, the performance of transcritical alternative is found better than the proposed cascade system. Moreover, the performance of transcritical system is observed slightly lower than those of the cascade system in hot climate regions of Turkey such as Aegean, Mediterranean and South-East Anatolian regions. It is also found that the performance of the transcritical system is better in regions having lower ambient conditions such as near the Black Sea and eastern regions of Turkey. Therefore, for the mild and cold regions of Turkey, the transcritical ejector option is the better alternative due to having higher performance compared to the cascade system.
KEYWORDS
PAPER SUBMITTED: 2018-09-11
PAPER REVISED: 2018-11-30
PAPER ACCEPTED: 2018-12-06
PUBLISHED ONLINE: 2018-12-16
DOI REFERENCE: https://doi.org/10.2298/TSCI180911348Y
REFERENCES
  1. Llopis, R., Sanchez, D., Sanz-Kock, C., Cabello, R., Torrella, E., Energy and Environmental Comparison of Two-Stage Solutions for Commercial Refrigeration at Low Temperature: Fluids and Systems, Appl. Energ., 138 (2015), pp. 133-142.
  2. Gullo, P., Tsamos, M.K., Hafner A., Banasiak, K., Ge, T.Y., Tassou, S., Crossing CO2 Equator with the Aid of Multi-Ejector Concept: A Comprehensive Energy and Environmental Comparative Study, Energy, 164 (2018), pp. 236-263.
  3. Gullo, P., Hafner A., Banasiak, K., Transcritical R744 Refrigeration Systems for Supermarket Applications: Current Status and Future Perspectives, Int. J. Refrig., 93 (2018), pp. 269-310.
  4. Hafner, A., et al., Multi-Ejector Concept for R-744 Supermarket Refrigeration, Int. J. Refrig., 43 (2014), pp. 1-13.
  5. Li, D., Groll, E. A., Transcritical CO2 Refrigeration Cycle with Ejector-Expansion Device, Int. J. Refrig., 28 (2005), pp. 766-773.
  6. Zhang, Z., Ma, Y., Wang, H., Li, M., Theoretical Evaluation on Effect of Internal Heat Exchanger in Ejector Expansion Transcritical CO2 Refrigeration Cycle, Appl. Therm. Eng., 50 (2013), pp. 932-938.
  7. Bhattacharyya, S., Ahammed, E., Ramgopal, M., Thermodynamic Design and Simulation of a CO2 Based Transcritical Vapour Compression Refrigeration System with an Ejector, Int. J. Refrig., 45 (2014), pp. 177-188.
  8. Kim, M.S., Kim, M.S., Lee, J.S., Studies on The Performance of a CO2 Air Conditioning System Using an Ejector As an Expansion Device, Int. J. Refrig., 38 (2014), pp. 140-152.
  9. Haida, M., Smolka, J., Palacz, M., Bodys, J., Nowak, A.J., Bulinski, Z., Fic, A., Banasiak, K., Hafner, A., Numerical Investigation of an R744 Liquid Ejector for Supermarket Refrigeration Systems, Therm. Sci., 20 (2016), pp. 1259-1269.
  10. Bodys, J., Palacz, M., Haida, M., Smolka, J., Nowak, A.J., Banasiak, K., Hafner, A., Full-Scale Multi-Ejector Module for a Carbondioxide Supermarket Refrigeration System: Numerical Study of Performance Evaluation, Energ. Convers. Manage., 138 (2017), pp. 312-326.
  11. Gullo, P., Hafner, A., Cortella, G., Multi-ejector R744 Booster Refrigerating Plant and Air Conditioning System Integration - A Theoretical Evaluation of Energy Benefits for Supermarket Applications, Int. J. Refrig., 75 (2017), pp. 164-176.
  12. Llopis, R., Sanchez, D., Sanz-Kock, D., Cabello, R., Torrella E., Experimental Evaluation of An Internal Heat Exchanger In a CO2 Subcritical Refrigeration Cycle With Gas-cooler, Appl. Therm. Eng., 80 (2015), pp. 31-41.
  13. Sarkar, J., Agrawal, N., Performance Optimization of Transcritical CO2 Cycle with Parallel Compression Economization, Int. J. Therm. Sci., 49 (2010), pp. 838-843.
  14. Karampour, M. and S. Sawalha, State-of-the-art Integrated CO2 Refrigeration System for Supermarkets: A Comparative Analysis, Int. J. Refrig., 86 (2018), pp. 239-257.
  15. Llopis, R., et al., Subcooling Methods for CO2 Refrigeration Cycles: A Review, Int. J. Refrig., 93 (2018), pp. 85-107.
  16. Catalán-Gil, J., et al., Energy Evaluation of Multiple Stage Commercial Refrigeration Architectures Adapted to F-Gas Regulation, Energies, 11 (2018), pp. 1915.
  17. Haida, M., Banasiak, K., Smolka, J., Hafner, A., Eikevik T.M., Experimental Analysis of The R744 Vapour Compression Rack Equipped with The Multi-Ejector Expansion Work Recovery Module, Int. J. Refrig., 64 (2015), pp. 93-107.
  18. Yılmaz, T., Bulut, H., New Ambient Temperature Design Values for Turkey, 10th National Installation Engineering Congress and Exhibition, Izmir, Turkey, 2001, pp. 293 -311.
  19. Robinson, D.M., Groll, E.A., Efficiencies of Transcritical CO2 Cycles With and Without an Expansion Turbine, Int. J. Refrig., 21 (1998), 7, pp. 577-589.