330MW机组凝汽器真空低原因分析及处理

Analysis and Treatment on Low Vacuum of Condenser in 330 MW Unit

在火力发电厂中,汽轮机凝汽器的真空是衡量机组经济性的重要指标之一,凝汽器真空过低,不仅会影响汽轮发电机组的经济性,而且会影响汽轮机的安全性.主要介绍江苏华电扬州发电有限公司7#机组在运行过程中凝汽器真空偏低的情况,通过现场查看,以及对运行数据的分析,发现机组凝汽器真空偏低的原因是由于真空泵工作液温度过高抽气不足所致,通过进一步分析后,发现真空泵工作液温度偏高是由于闭冷水温度偏高所致.最后,通过改变循泵的运行方式,降低了闭冷水温度和真空泵工作液温度,凝汽器真空得到了提高.

In the power plant,the vacuum of the steam turbine condenser is one of the important indexes to evaluate the economic performance of the unit. If the condenser vacuum is too low,it will affect the safety as well as the economy of the steam turbine. This paper mainly introduces the operation process of No. 7 unit with low condenser vacuum in Yangzhou Power Generation Co.,Ltd. of Jiangsu Huadian. Based on the site and the analysis of operating data,it is found that the low vacuum of the condenser is due to the high temperature of the working fluid in vacuum pump. By further analysis,it is found that the high temperature of the working fluid in vacuum pump is due to the high temperature of the closed cold water. Finally,the vacuum of the condenser is improved by changing the running mode of the circulating pump.