Keywords: exergy analysis, carbon dioxide, two-stage compressor, flash gas removal, FGR, air conditioning cycles, energy balance, exergy loss, intercooler, evaporator, expansion valve, heat exchanger
Exergy analysis of advanced transcritical CO2 air conditioning cycles
The energy and exergy balance methods were performed on two advanced transcritical CO2 air conditioning cycles presented in the literature. In addition to the basic transcritical CO2 air conditioning cycle which has five main components, compressor, gas cooler, evaporator, expansion valve and internal heat exchanger, two advanced cycles are investigated; both have two-stage compressor (low stage and high stage) and intercooler, with one of them has an additional Flash Gas Removal (FGR) chamber. The results demonstrated that the compressor-low stage has the largest exergy loss, while the intercooler has the smallest exergy loss in advanced transcritical CO2 air conditioning cycles. Moreover, it demonstrated that the FGR had a minimal effect on improving COP of the system.