An experimental and theoretical study of a CO2 ejector

In this paper we represent the performance of an ejector used in the CO2 heat pump water heater system by means of experimental and theoretical studies. This work accounts for the effects of primary flow pressure, entrained flow pressure and back pressure on the entrainment ratio in off-design conditions. The performance of the ejector is experimentally investigated in a CO2-ejector test rig. Using ejector characteristic-curve equations, we provide predictions in good agreement with the experimental data. Furthermore, the model predictions will be utilized as a design tool for optimizing the performance of next generation ejector.