大型水轮机组热电阻制造和安装工艺问题分析及处理对策

Analysis and Treatment on Thermal Resistance Manufacturing and Erection Technology Problems in Large Hydraulic Turbine Set

水力发电测温电阻的设置是为了动态监测水轮发电机组导轴承的受热以及定子铁芯、线圈的发热情况,从中判断机组是否处于正常受控状态。而由于热电阻制造、安装工艺造成温度信号误报一直困扰着电厂运行人员和检修维护人员,严重时可造成机组事故停机。文章首先论述了水轮机组轴承测温电阻制造安装时常见的问题,接着针对这些问题展开探讨,提出改进意见及处理对策。大化水电厂5号机组轴承、定子铁芯和线圈测温系统经改造后投运2年半,至今未出现过一例因热电阻问题而发生的故障,这对减少设备的维护工作量,降低设备故障率,确保机组的安全运行起到了关键的作用。

In hydropower projects, the thermal resistor is set for dynamic monitoring of the heated conditions of the guide bearing of hydro-generator unit and the heating conditions of the stator core and coil, so as to judge the operation conditions of unit. However, the false temperature signals, caused by manufacturing and erection technologies of thermal resistor, always trouble the operators and the maintenance personnel, which even cause emergency shutdown in serious false alarms. The paper discusses the common problems encountered during manufacturing and erecting the thermal resistor for turbine generator unit bearing, and proposes some improvement suggestions and countermeasures. After improvement, no false signal had been received from the temperature measuring system of the bearing, stator core and coil of No. 5 unit of Dahua hydropower station since been put into operation in the past two and a half years, which played a key role in reducing equipment maintenance workload and equipment failure rate and in ensuring safe operation of unit.