Fig. 4: Simulation results of the two-stage cycle with subcooling (SC).
From: A unified approach for the thermodynamic comparison of heat pump cycles
In this case study, considering R134a as the refrigerant, the condensing and evaporating temperatures are 65 °C and 0 °C, respectively. The results are similar to the Flexible Heat Pump cycle34. a The calculated COP improvement \(\alpha\) varies when the intermediate temperature \({T}_{i}\) in the flash tank increases for different condensing temperatures. b The maximum COP improvement (Max α) increases as the condensing temperature increases. c The corresponding optimal flash tank temperature (optimal \({T}_{i}\)) increases as the condensing temperature increases.
