Influence of Steam Ejector on Low-temperature Multi-effect Distillation System Under Wide Load Operation of Power Plant

The problem of lack of fresh water resources becomes more and more serious. The coupling of low-temperature multi-effect distillation (LT-MED) seawater desalination technology in thermal power plants is widely used, because it can effectively reduce the cost of water production. Ebsilon software was used to model the power plant and a LT-MED seawater desalination coupling system. The influences of steam ejectors on the thermal economy of the water and power cogeneration system under wide load were analyzed. The results show that the couple d system has the optimal performance for single-stage steamejector at the 75% THA condition design of the power plant. For a cogeneration system with a two-stage steam ejector, the system's electricity loss for water production (ELWP) is reduced by 13.65% than the system with single-stage steam ejector, when the plant load is at 75% THA. And the two-stage steam’s ELWP is also lower than that of the single stage steam ejector system when the plant load is above 50% THA.