针对给水泵汽轮机真空建立的排汽管道改造

Exhaust pipe renovation for establishment of vacuum in feedpump-driving turbine system

分析比较了给水泵汽轮机投轴封及真空建立的两种方式:无旁通阀方式和有旁通阀方式,指出了两者的优缺点。对现有的方式提出了改进措施,即取消真空蝶阀和旁通阀,在真空蝶阀前增加一路管径为DN80的抽空气管道接至真空泵入口。该改进方案对凝汽器真空的影响小,安全性高,厂用电增加少,并提高了机组运行方式的灵活性。

This paper analyzes and compares two approaches for vacuum establishment in feedpump-driving turbine system. i. e. the approach without by-pass valves and that with by-pass valves. The advantages and disadvantages of these two traditional approaches are indicated. A measure for improvement is presented, in which the vacuum butterfly valve and the by-pass valve are cancelled, and a DN80-caliber suction pipe is added in front of the vacuum butterfly valve and connected to the vacuum pump intake. The improved method has little influence on condenser vacuum and is of high safety; meanwhile. it improves the operation flexibility of units without notable increase in auxiliary power consumption.