Preliminary study on CO₂ transcritical ejector enhanced compressor refrigeration system for independent space cooling and dehumidification

This study presents a single CO₂ vapour-compression system for independent cooling and dehumidification of indoor air conditioning systems. A CO₂ gas cooler outlet split (GOS) ejector system is introduced to generate two levels of evaporating temperature, and therefore indoor air temperature and humidity can be controlled independently. The two-phase ejector improves energy efficiency of the CO₂ transcritical system by recovering expansion work loss. The steady state analysis shows that the COP of the CO₂ ejector system is 12–60% better than that of standard isenthalpic expansion one when the humidity load ratio covers 10–50% of the total thermal load. Moreover, transient performances of the CO₂ GOS ejector system under different indoor load conditions are simulated. It proves that the hybrid GOS GCHPing system offers a solution to the future air conditioning sector to use the environmentally friendly CO₂ as long term working fluid.