某1000MW超超临界机组高温再热蒸汽管道异常膨胀原因探讨

Reason Analysis of High Temperature Reheater Piping Abnormal Expansion of 1000MW Ultra-supercritical Power Plant

某1 000 MW超超临界机组管道支吊架检查过程中发现高温再热蒸汽管道膨胀异常,该管道大量恒力吊架指示异常,部分恒力吊架冷态和热态均处于下极限位置,严重阻碍管道正常膨胀。从管道布置设计,支吊架设置,管道壁厚和附件重量,以及现场阻尼器异常受阻四方面探讨管道异常膨胀的原因,为进一步处理该问题提供理论依据,并为高温高压蒸汽管道的设计和现场安装提出参考意见。

The abnormal thermal expansion of high temperature reheater steam piping was found in the process of cold and hot state inspection of hangers and supports for 1 000 MW ultra-supercritical unit. Many displacement pointers of the constant spring hangers were in abnormal place. Some constant spring hangers were at lowest position for both cold and hot state, which severely impeded the normal thermal expansion of the high temperature reheater steam piping. Four aspects for the abnormal thermal expansion are discussed： piping layout, arrangement of support-hangers, wall thickness of piping and weight of piping fittings, snubber expansion impediment, which provides the theoretical basis for solving similar problems and the references for the design and installation of high temperature and high pressure steam pipings.