Optimization of VD/VOD multi-stage serial steam ejectors based on CFD

Abstract

The objective of this research is to optimize the first two-stage ejectors of a VD/VOD system in order to increase the entrainment ratio (ER) of the system. By optimizing the first ejector, its working point is located in the double choked region, and its entrainment ratio increases up to 0.342. Furthermore, the maximum back pressure corresponding to the breaking point of the optimized first ejector increases by 12.1% compared to its original state. The working point of the original second ejector is in the single choked region and the performance of this ejector is also low. By optimizing the second ejector, the working point becomes closer to the double choked region, and its entrainment ratio increases by 26.43%. The outlet pressure corresponding to the breaking point of the optimized second ejector increases by 5.1% compared to its original state.