采用等值刚度法计算程序对某电厂主蒸汽管道在水压试验堵阀去除后其附近支吊架的工作载荷、管道受到的应力以及管道对锅炉末级过热器出口联箱的推力进行了计算分析。结果表明: 去除堵阀后, 其附近支吊架的工作载荷减小, 主蒸汽管道受到的一次应力极大升高, 且最大应力点发生了转移。因此, 需要对管道上的支吊架结构进行整改, 将堵阀附近的一横担恒力吊架改为单个恒力吊架。等值刚度法计算结果表明: 该整改方法即可保证主蒸汽管道在水压试验堵阀去除后能够正常运行, 同时利于水压试验堵阀的回装。

Work load, stress and thrust force of the nearby main steam pipeline after removing the blocking valve were calculated and analyzed by using the equivalent stiffness element method. The results show that the work load of the nearby supports and hangers decreased, the stress of the main steam pipeline increased significantly, and the maximum stress point shifted. So the structure of the supports and hangers must be rectified by replacing the original double hangers with a single hanger. The calculation and analysis results of equivalent stiffness element method show that after the rectification, the main pipeline could operate normally and it also is helpful to reinstall the blocking valve.