EFFECTS OF DEGREE SUPERHEATING MOTIVE FLOW ON THE FLOW STRUCTURE IN STEAM EJECTOR BY USING COMPUTATIONAL FLUID DYNAMICS

The ejector is important in the refrigeration cycle, making it a vital component. In recent times, the use of ejectors has surged due to the growing emphasis on reducing environmental pollution, especially in response to climate change and the need for energy conservation. However, there is a research gap in the domain of steam ejectors regarding the investigation of flow behavior under high degrees of superheating. This study aims to fill that gap by examining the influence of high degrees of superheating on the ejector. Degrees of superheating (DOS) of 50, 100, 150, and 200 K are considered, and the study explores how phase change affects the flow pattern. The Kantrowitz nucleation model is employed to simulate the liquid phase phenomena. The outcomes demonstrate that as the degrees of superheating increase, the intensity and location of aerodynamic shocks alter, while the liquid mass fraction and motive mass flow rate decrease. Furthermore, the maximum velocity and suction mass flow rate in the ejector increase. When the DOS increases from 50 to 200 K, the entrainment ratio changes by +20.1%, the motive mass flow rate decreases by -13.4%, and the suction mass flow rate increases by 3.7%.