燃煤机组管道吊架位移稳定性评价

Evaluation of displacement stability of pipeline hangers of coal-fired units

管道的膨胀位移特性影响燃煤机组安全性。基于在线监控数据对某超超临界机组管道吊架位移变化情况进行分析评价,构建稳定性评价函数对不同运行阶段的管道吊架位移进行评价。结果表明:管道吊架冷态停炉时位移量维持在冷态设计值左右。热态运行时位移量在热态设计值附近波动。机组启动过程,吊架位移量快速达到热态设计值附近。并网前子阶段吊架的膨胀位移程度比并网后子阶段更大。停机过程吊架位移变化集中在冷却子阶段。热态运行阶段热再蒸汽管道吊架位移稳定性最好,冷再蒸汽管道吊架位移波动最大,稳定性得分比热再管道吊架降低21.8%。机组启动过程各管道吊架位移变化稳定性基本相同。停机过程冷再蒸汽管道吊架位移变化最平稳,主蒸汽管道吊架位移变化相对剧烈,稳定性得分比冷再蒸汽管道吊架降低17.2%。构建的评价函数能准确表述管道吊架膨胀位移特性,为机组安全提供数据支持。

The expansion displacement characteristics of pipelines affect the safety of coal-fired units.Based on online monitoring data,the displacement changes of pipeline hangers for a certain ultra supercritical unit were analyzed and evaluated,and a stability evaluation function was constructed to evaluate the displacement of pipeline hangers at different operating stages.The results indicate that the displacement of the pipeline hanger during cold shutdown is maintained around the cold design value.During hot operation,the displacement fluctuates around the hot design value.During the startup process of the unit,the displacement of the hanger quickly reaches the hot design value.The expansion displacement of the hanger in the pre grid connection sub stage is greater than that in the post grid connection sub stage.The displacement changes of the suspension during the shutdown process are concentrated in the cooling sub stage.During the hot operation stage,the displacement stability of the hot reheat steam pipeline hanger is the best,while the displacement fluctuation of the cold reheat steam pipeline hanger is the largest.The stability score is 21.8%lower than that of the hot reheat pipeline hanger.The stability of the displacement changes of each pipeline hanger during the unit startup process is basically the same.The displacement change of the cold reheat steam pipeline hanger during the shutdown process is the most stable,while the displacement change of the main steam pipeline hanger is relatively severe,with a stability score of 17.2%lower than that of the cold reheat steam pipeline hanger.The constructed evaluation function can accurately describe the expansion displacement characteristics of pipeline hangers,providing data support for unit safety.