A CFD-based investigation of the two-phase R744 ejectors: Flow pattern nozzle design

摘要

Ejector is a promising device to recover throttling loss and increase system efficiency. A CFD-based numerical analysis of a two-phase R744 ejector is presented in this work. A numerical model based on a heterogeneous equilibrium approach is used to simulate the R744 ejector. Based on the experimental work, the numerical model is validated. The flow pattern inside the ejector is studied using the numerical method. The effect of the ejector's nozzle geometry on the ejector performance is discussed, and an optimization of the nozzle geometry is performed. Based on the experimental data, the numerical model predicts the motive mass flow rate and the suction pressure within an error margin of 7%. The optimization of the nozzle geometry can increase the ejector efficiency by 10.5%.