超临界机组P91主蒸汽管道温度计套管焊接改造

我国火力电厂四大管道系统尤其是P91主蒸汽管道系统多次发生温度计套管插接式角焊缝爆漏事故.认真分析了温度计套管焊缝爆漏事故产生的原因,从材料配套选择、焊接方案改造、检验方案改进入手,对2号机组四大管道部分温度、压力套管进行改造,后经第三方全面检验100％合格,从试运投产至今未发生一起漏泄事故.对在建同类型机组也具有良好的借鉴作用.

Welding Transformation of Thermo-well at Supercritical Unit P91 Main Steam Pipe

Burst leak often occurs in four pipe system of thermal power plants in China, especially in thermo-wells plug-in fillet weld of the P91 main steam piping system on many occasions. This paper makes a careful analysis of the causes of the thermowells weld explosive leak, tries to improve the program from the supporting material selected, welding program and test program, reforms the part of the temperature, pressure tube in the four pipeline of the Unit 2. The result shows 100% qualification rate under a comprehensive test made by a third party, and leakage accident has not occurred in the Unit from its trial run production.