Study on the performance of a steam ejector with auxiliary entrainment inlet and its application in MED-TVC desalination system

In order to optimize the performance of a steam ejector used in a MED-TVC desalination system, an auxiliary entrainment inlet is added at the ejector’s low pressure region. The steam ejector is simulated by using the CFD method to investigate the position, width and pressure of the auxiliary entrainment inlet. Detailed analyses and discussions are presented based on the ejector inlet and outlet mass flow rates, internal pressure contours and velocity vector fields. The results indicate that when the pressure at the auxiliary entrainment inlet exceeds a certain value, the internal backflow can be effectively avoided. Besides, there exists an optimal position and width of the auxiliary entrainment inlet. Compared with the conventional ejector, the entrainment ratio is slightly increased by 2.7%, but the ejector outlet mass flow rate can be increased about 15.5% for the auxiliary entrainment inlet with the optimal position and width. Therefore, for a MED-TVC desalination system, applying a steam ejector with auxiliary entrainment inlet can effectively increase the efficiency of the system and increase the production of fresh water.