火电站低温低压系统楔形闸板阀在线带压解体检修分析

Overhaul Analysis of Wedge Gate Valves in Low Temperature and Low Pressure System of Thermal Power Plant

润滑油系统的作用是给汽轮发电机的支持轴承、推力轴承和盘车装置提供润滑,为氢密封系统提供备用油以及为操纵机械超速脱扣装置提供压力油。对于高速运转的机组来说,哪怕短暂时间(如几秒钟)的供油中断也会引起重大事故。首先是轴承的巴氏合金因中断冷却而熔化,机组的转子失去支撑,动静部分将发生严重磨损。而调节系统断油,整台机组将失去控制。因此,保证油系统的正常工作对机组的安全至关重要。本文针对辽宁清河发电厂1号机组A主冷油器冷却水回水门阀板脱落事件,对该阀门在线带压解体检修工作进行了分析,识别各项安全风险,并有针对性地制定了防范措施,且分析了阀板脱落的根本原因,进行了有效处理,并提出了相应的改进措施和建议。

The function of the lubricating oil system is to provide lubrication for the support bearings,thrust bearings and cranking devices of the turbine generator,to provide backup oil for the hydrogen sealing system and to provide pressure oil for operating the mechanical overspeed tripping device.For high-speed units,even a short period of time(such as a few seconds)of oil supply interruptions can cause major accidents.The first is that the bearing’s babbitt alloy melts due to interruption of cooling,the rotor of the unit loses support,and the static and dynamic parts will be severely worn.When the regulation system is cut off,the entire unit will lose control.Therefore,ensuring the normal operation of the oil system is critical to the safety of the unit.In response to the falling off of the main water cooler cooling water return valve valve plate of Unit A of Qinghe Power Plant in Liaoning Province,the valve was repaired by online pressure disassembly,identify various safety risks,and targeted preventive measures were developed and analyzed.The root cause of the valve plate falling off was effectively dealt with,and corresponding improvement measures and suggestions were put forward.