650MW汽轮机主汽阀内漏机理研究

Research on Internal Leakage Mechanism of Main Steam Valve of 650MW Steam Turbine

从国内某核电机组主汽阀长期内漏缺陷出发,全面剖析了主汽阀的结构和原理,对可能引起主汽阀内漏的原因逐一进行分析和讨论,采用理论研究和力学计算相结合的方法,明确了主汽阀内漏机理,确定了该主汽阀长期内漏的根本原因。研究结果表明,空气滑阀强度足够阻止主汽阀阀碟回座到位,空气滑阀高度过大会使主汽阀密封面无法贴合而内漏。给出了空气滑阀的调整方案,可使其发挥自身功能而又不影响主汽阀密封,对650MW汽轮机主汽阀的检修和设计具有指导意义。

Starting from the long-term internal leakage defect of the main steam valve of a domestic nuclear power unit,this article comprehensively analyzes the main steam valve structure and principle,analyzes and discusses the possible causes of the main steam valve internal leakage one by one,and adopts a method of combining theoretical research and mechanical calculations.Clarified the internal leakage mechanism of the main steam valve,and determined the root cause of the long-term internal leakage of the main steam valve.The research results show that the strength of the air slide valve is sufficient to prevent the valve disc of the main steam valve from returning to its seat,and the height of the air slide valve is too large to make the sealing surface of the main steam valve unable to fit and internal leakage.The article gives an adjustment plan for the air slide valve,which can make it play its own functions without affecting the main steam valve seal.The thesis has guiding significance for the maintenance and design of the main steam valve of 650MW steam turbine.