核电厂MSIV空气减压阀卡涩原因分析与改进措施

The Jamming Cause Analysis and Resolution of the MSIV Air Conditioning Valve

摘要: 主蒸汽隔离阀执行机构的空气减压阀在核电厂运行期间易出现卡涩现象，严重影响核电厂机组的稳定运行。本文通过对减压阀工作原理和运行受力状态进行分析，发现造成阀门卡涩的原因有阀门结构缺陷、设计选型不当、制造精度低、配合间隙大、耐磨性能差。为了彻底解决减压阀卡涩问题，采用新型空气减压阀代替原阀门，并对新阀进行了结构分析和性能试验，结果表明替代阀门结构设计合理、关键部件选材合适、各项性能优异，且消除了阀门卡涩隐患，能够代替原阀门执行安全功能，保证了主蒸汽隔离阀的稳定运行，具有广泛推广价值。

Abstract: Jamming is a normal failure of the main steam isolation valve’s (MSIV) air conditioning valve during operation. This failure will significantly affect the stably operation of the nuclear power plant. The operation principle and stressing feature are analyzed, which shows the cause of jamming including structural defects, weak design, low manufacturing precision, big assembly space and poor wear-resisting property. In order to solve the jamming problem, a new type air conditioning valve is selected to substitute the former type. Structural analysis and performance test are implemented, which shows that the new type valve has better structural design and material properties. The high performance can prevent the air condition valve from jam. The new type valve can substitute the former one to perform safe function, and can ensure the stable operation of the MSIV.