冷却水流径对双流程凝汽器热力性能的影响

The Effects on Thermal and Mechanical Performance of Double Tube-passes Condensers in Two Different Cooling Water Paths

双流程大型电站凝汽器的冷却水流径主要有上进下出和下进上出两种。利用自行开发的凝汽器工作性能数值模拟软件PPOC3.0模拟和分析了4台不同管束类型的双流程凝汽器在这两种不同冷却水流径情况下的热力性能。结果表明,对于从顶部进汽的大型电站凝汽器,采用上进下出的冷却水流径,可以减小凝汽器的汽阻和凝结水的过冷度,并且改善凝汽器水侧的水力特性。冷却水流径对凝汽器热负荷的影响与凝汽器具体的管束型式有关,将冷却水的第一流程安排在有抽气口和空冷区的管束部分,可以提高凝汽器的热负荷。

There are mostly two types of cooling water paths for double tube- passes condensers, which are upper-lower path and lower-upper path, respectively. The computer program PPOC3.0 developed by author is applied to simulate and analyze the thermal performance of four sets of double tube-passes condensers in two different cooling water paths. The resuits show that the steam-side flow resistance and sub-cooled temperature of condensate in the condenser can be reduced,and the waterside hydraulic performance can be improved in upper-lower cooling water path. The effect of cooling water path on heat flux is relevant to tube boundle arrangements, and the heat flux can be improved by arranging the first cooling water path in the tube nest where the vent and air cooling regions are located.