某660 MW机组主蒸汽管道膨胀异常原因分析及治理方案

Cause analysis and treatment on main steam piping abnormal expansion in a 660 MW unit

针对某电厂主蒸汽管道热膨胀位移异常状况,进行管道支吊架状态检查、性能测试和管系应力计算,分析支吊架状态异常对管系应力分布的影响,并与设计工况下的管系应力进行对比。发现恒力支吊架旋转机构卡死对管道的二次应力影响较大,最大处超过设计工况的2倍,严重影响管道的安全运行。应加强管道的金属监督和日常巡检,通过支吊架状态调整能够改善管道的应力分布,有效解决由支吊架引起的管道膨胀异常问题。

In response to the abnormal thermal expansion displacement of the main steam pipeline in a certain power plant,pipeline support and hanger status inspection,performance testing,and pipeline stress calculation were carried out.The impact of abnormal support and hanger status on the stress distribution of the pipeline system was analyzed and compared with the pipeline stress under design conditions.It was found that the locking of the rotating mechanism of the constant force support and hanger has a significant impact on the secondary stress of the pipeline,with the maximum exceeding twice the design condition,seriously affecting the safe operation of the pipeline.Therefore,metal supervision and daily inspection of the pipeline should be strengthened.Adjusting the status of supports and hangers can improve the stress distribution of pipelines and effectively solve the problem of abnormal pipeline expansion caused by supports and hangers.