TY - JOUR
TI - Comparative evaluation of a two-stage refrigeration system with flash intercooling using different refrigerants
AU - Mancuhan Ebru
JN - Thermal Science
PY - 2020
VL - 24
IS - 2
SP - 815
EP - 830
PT - Article
AB - The aim of this study is to investigate the effect of low global warming  potential refrigerants on the optimum intermediate pressure (POPT’int) and  performance (COP) values of a refrigeration system with flash intercooling.  For realize, the optimum operating parameters of system were determined in  low temperature applications (LTAs) through a theoretical analysis according  to the different refrigerants (R290, R404A, R407C, R50A and R22). The  theoretical modeling of system is done by optimizing the intermediate  pressure at given evaporation (TE) and condensation (TC) temperatures for  selected refrigerants. After optimization, the maximized values of COP and  second law efficiency are computed from the predicted values of POPT’int.  The linear regression method is then used to derive three correlations of  POPT’int, maximum values of COP and second law efficiency according to TE  and TC. Hence, the POPT’int values maximizing the system performance are  found from various TE and TC values for each refrigerant. Due to  calculations, increasing TE and TC cause the increase in POPT’int in LTAs.  R507A system has the highest POPT’int values and R22 system has the lowest  POPT’int values. Although R22 system has slightly more efficient than R290  system, it is being phased out worldwide because of the risk of ODP and GWP  considerations. Therefore, it is important to evaluate the R22 replacement  options. R290 was discovered to have better performance than the R404A,  R407C and R507A systems in terms of COPmax (1.81), GWP (11) and ODP (0) when  TE and TC are -35ºC and 40ºC.