Supersonic Nozzle Location in Steam Ejector Effect on the Mass Fraction and Vacuum of Second Fluid

The steam ejector, an essential auxiliary device, finds extensive use in various applications, including Multiple Effect Evaporation Desalination systems. The present study endeavored to evaluate the impact of different Converging-Diverging Nozzle placements. Initially, a vapor ejection was designed under certain conditions, utilizing one-dimensional compressible flow equations. Subsequently, the flow within the vapor ejection was simulated via a computational fluid dynamics (CFD) application, specifically the ANSYS program. The investigation entailed the selection of multiple nozzle locations and the examination of their effects under two scenarios: one with a constant back pressure for various suction pressures at each nozzle location, and the other with a fixed suction pressure coupled with several exit pressures. Results from the first scenario indicated that the optimal nozzle location was 5 mm from the commencement of the mixing area. For the second scenario, it was observed that closer proximity of the nozzle to the mixing area enhanced the performance of the steam ejector.