Thermodynamic performance evaluation of HFC refrigerants for the chiller system simulated by hot gas bypass cycle
The competitive of the building air-conditioning equipment pushes manufactures to develop and improve the performance and efficiency of their products. This process is cost and time consuming for testing the whole units. In this study, for the first time a modified proposed test block with hot gas bypass cycle (HGBP), based on the experimental compressor map, has been used as a model to investigate the theoretical performance of the chiller system. The model assumes one dimensional steady state conditions and uses an experimental compressor map to predict the thermodynamic performance of the system. A computational model, using the software program EES (EES-V8.4), in a single stage of the chiller system with HGBP cycle based on the first and second law analyses are presented for the prediction of the effects of the pressure ratio, degree of superheating and sub-cooling, condenser temperature, outdoor air temperature and humidity ratio on the exergy destruction, exergetic efficiency, gas power and coefficient of performance (COP) of the chiller system. The performance of the implemented model with various hydrofluorocarbon (HFC) refrigerants such as R134a, R152a and R423a are compared. The results, firstly, indicates that the modified model with applying the energy and exergy analysis works for all kind of working refrigerants including HFC refrigerants. Secondly, the performance of the compression refrigeration system based on the experimental compressor map data to choose the right compressor can help engineers to design a high quality unit before going to design the system practically. The results indicate that R423a has a higher coefficient of performance as compared to the rest of the refrigerants. The developed simulation model helped to establish the strong dependence between system performances and the compressor map.
A. Arora and S.C. Kaushik. 2008. Theoretical analysis of a vapour compression refrigeration system with R502a, R404a and R507a. International Journal of Refrigeration, Vol. 31, pp. 998-1005
S. S. Seyitoglu and A. Kilicarslan. 2005 Second law efficiency of different refrigerants in a two stage vapour compression cycle. Journal of Thermal Science and Technology, Vol. 35, pp. 89-97,.
S. Devotta, A. S. Padalkar, and N. K. Sane. 2015 Perfor- mance assessment of HCFC 22 window air conditioner retrofitted with R407C. Applied Thermal Engineering, Vol. 25, pp. 2937-2949,.
F. Samuel, Y. Motta, and P. A. Domanski. 2000 Performance of R22 and its alternative working at high outdoor temperatures. Eighth International Conference at Purdue Univer- sity, pp. 47-54,.
E. Halimic, D. Ross, B. Agnew, and A. Anderson 2003 . A comparison of the operating performance of alternative refrigerants. Applied Thermal Engineering, 23, pp. 369-386,.
B. O. Bolaji. 2010 Exergetic performance of domestic refriger- ator using R12 and its alternative refrigerants. Engineering Science Technology, 5(4), pp. 435-446, .
R. Yumrutas, M. Kunduz, and M. Kanoglu.2002 Exergy analysis of vapour compression refrigeration systems. Exergy. 2:266–272.
J. McGovern. 1984 Analysis of a refrigernat compressor load stand incorporating hot gas bypass and a single full condensation heat exchanger. Proceedings of the International compressor engineering conference at Purdue uni- versity, 491: 468477,.
P. D. Gessler.2014 A one-dimensional model of a closed-loop refrigeration twst block for centrifugal compressors. Master Thesis, Marquette University, 2014.
K. Wark.2002 Advanced thermodynamics for engineers. McGraw-Hill, New York, 1995.
C. Apera and A. Greco. An exergetic analysis of R22 sub- stitution. Applied Thermal Engineering, 22 (13):1455–1469,
R. P. Mandi, R. K. Hegde, and S. N. Sinha. 2005 Performance enhancement of cooling towers in thermal power plants through energy conversion. Power Tech IEEE Explore, Russia, doi: 10.1109/PTC. , 4524607.
G. P. Narayan, K. H. Mistry, M. H. Sharqawy, S. M. Zubair, and J. H. Lienhard. 2010 Energy effectiveness of simultaneous heat and mass exchange devices. Frontries in Heat nad Mass Transfer, 1:023001., 2010.
[T. Muangnoi, W. Asvapoostkul, and S. Wongwises2007. An exergy analysison the performance of a counterflow wet cooling tower. Applied Thermal Engineering, 27:910–917.
R. E. Sonntag, C. Borgnakke, and G. V. van Wylen.2009 Fundamental of Thermodynamics. sixth Edition,John Wiley and Sons, Inc.
Y.Wang, F. Lin, C. Nie, and A. Engeda. 2013 Design and performance evaluation of a very low flow coefficient centrifugal compressor. International Journal of Rotating Machinery, 4:12 pages.
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