葛洲坝机组新事故配压阀动作异常原因分析及处理

Analysis and treatment of accident pressure valve malfunction in Gezhouba Hydropower Station units

葛洲坝机组在扩大性B修后的调速器修后机械(无水)试验中,新更换的事故配压阀出现了投入后导叶关闭异常缓慢、动作后复归过程延迟等现象。针对新事配出现的异常现象,对事配结构和事配动作油路进行分析,并通过现场重新拆除事配本体进行逐级检查,最终确定其原因是事配的回油腔侧端盖在出厂时加工错误,导致事配在投入和复归过程中,流过事配阀的油路不顺畅。对回油腔侧端盖重新加工处理后,事故配压阀能够正常动作。

In the mechanical test(water-free)for speed controller after B class maintenance of Gezhouba Hydropower Station units,it was found that the guide vane closed fairly slow and its reset process has delayed even after replacing a new accident pressure valve.In order to tackle this problem,we analyzed the structure of valve and its oil path,and carried out an inspection on the valve which were dismantled.We found that the malfunction was caused by the incorrect handling of end cover on the oil cavity,resulting in a blockage of oil path during the valve input and reset processes.The valve operated normally after re-processing the end cover on oil cavity.