The shortage of freshwater resources is becoming increasingly serious. A thermal power plant coupled with a low-temperature multi-effect distillation seawater desalination (single-stage thermal vapor compressor (TVC)) has been widely used. To reduce the water production cost effectively, a two-stage TVC is proposed in this study. The simulation work for the system performance under single- and two-stage TVC is analyzed. Results show that the performance of the system coupled with the two-stage TVC is superior under most conditions, and an optimal intermediate pressure (16 kPa) of the two-stage TVC is found for minimum coal consumption. When the power plant load is higher than 70% THA, the cogeneration system performs well, and the motive steam of the two-stage TVC comes from extraction point No. 5. Otherwise, the motive steam that comes from extraction point No. 4 is a suitable choice. The maximum coal consumption reduction value is 1.48 t/h. To deal with the low operation load of power plants in China, 60% THA load of power plant is a suitable choice for two-stage TVC of power-water cogeneration system.

淡水资源短缺日益严重。结合低温多效蒸馏海水淡化（单级热蒸汽压缩机（TVC））的热电厂已得到广泛应用。为了有效降低产水成本，本研究提出了两级 TVC。分析了单级和两级TVC下系统性能的仿真工作。结果表明，在大多数条件下，系统与两级 TVC 相结合的性能优越，并找到了两级 TVC 的最佳中间压力 (16 kPa)，以实现最低的煤耗。当电厂负荷高于 70% THA 时，热电联产系统运行良好，两级 TVC 的动力蒸汽来自 5 号抽汽点。否则，来自 4 号提取点的动力蒸汽是一个合适的选择。最大煤耗降低值为1.48 t/h。为应对我国电厂运行负荷偏低的问题，电厂60%的THA负荷是水电联产两级TVC的合适选择。