Numerical analysis of heat pumps: Selection of the best fluids for maximizing the coefficient of performance
Abstract In this paper, numerical optimization analyses are performed for four distinct heat pump systems, namely, the CVI-1S, CVI-SR, CVI-2S and CVI-3S systems. These analyses are performed for various combinations of hot side and cold side temperature values (i.e., for hot side temperatures ranging from 25 °C to 60 °C, and for cold side temperatures ranging from -40 °C to 10 °C). A total of 167 fluids are compared in order to obtain the highest COP value, for each temperature combination investigated. A robustness analysis is also achieved so as to identify the fluids that provide a COP value larger than 95% of the maximal COP value. Results are presented as charts that allow identifying the best fluids and the most robust fluids for each heat pump system. The results show that heat pump systems involving more equipment or including separators are more efficient than the others. Moreover, the results show that the refrigerants dme, r161, r40, cf3i, r435a and r510a are among the most robust fluids for all heat pump systems investigated.