【作者】 田硕；

【导师】 刘长军；

【作者基本信息】 华东理工大学 ， 化工过程机械， 2012， 硕士

【摘要】 高压注射气体隔离阀是某类核电站核岛安全保护系统泄压管线的关键设备之一,其作用是在事故状态下及时准确得完成开启,实现管道泄压,对核电站的安全运行起着重要的保护作用。国内某核电站在更换了高压注射气体隔离阀的阀座等易损件后,出现了阀门不能在规定时间内开启的问题,经分析确定了更换的阀座备件导致了阀门的启动力矩过大,进而造成了阀门不能正常开启。据了解,此类阀门及阀座均由国外企业生产,我国核电企业对于此类阀门启动力矩分析方法及阀座对启动力矩影响情况并不明确。本文基于以上背景,以此类高压注射气体隔离阀为研究对象,对阀门的启动力矩和阀座对于启动力矩的影响情况进行了研究,主要研究工作和结果如下：(1)以现有的两类聚甲醛阀座为测试对象,试验测试阀座材料的压缩力学性能、压缩性能时间效应、摩擦性能及摩擦性能的时间效应,对比两类阀座材料性能的差别,并为数值模拟计算提供合适的材料性能参数。试验表明：两类阀座材料的力学性能存在一定差别,并且材料力学性能具有时间效应；两类阀座材料的摩擦性能基本一致,且摩擦性能也存在时间效应。(2)利用ABAQUS有限元分析软件,模拟计算了阀门在不同密封状态下,球体与阀座之间的接触受力情况及阀门的启动力矩,计算了相关影响因素对启动力矩的影响,最终分析确定了一种启动力矩计算方法。结果表明：阀门的启动力矩随加载时间的延长而增大,其原因是阀座材料力学性能和摩擦性能的时间效应的双重作用；阀座材料性能因素和结构尺寸因素通过影响阀座与球体间的作用力,进而影响阀门的启动力矩；在出口侧阀座密封状态下,阀座结构尺寸因素对启动力矩影响较大,而材料性能因素影响程度有限；在入口侧阀座密封状态下,阀座材料性能因素和结构尺寸因素均对启动力矩有显著影响。(3)设计开发了阀门模拟试验装置及启动力矩测试方法,通过试验的方式测试分析阀门的启动力矩、预紧位移-预紧力,并验证有限元数值模拟计算的可靠性。试验表明；在恒定载荷下,阀门的启动力矩具有时间效应,启动力矩随加载时间的延长而增大；试验结果与模拟计算的结果吻合度较高,证明了有限元计算的可靠性；本试验装置和试验方法可用于阀座备件的验收评定,具有较高的实用价值。更多还原

【Abstract】 High-pressure gas injection isolation valve is a control equipment in pressure releasing pipeline of security protection system for some kind of nuclear power plants, which is used to release pipeline pressure in the accident situation and ensure the safe operation of the nuclear power plant. The valve in a domestic nuclear power was in fault that the valve can not open within the prescribed time, after some vulnerable parts such as valve seat were replaced. It was determined that the cause of valve fault is that replacement of spare seat led to excessive pivoting torque. It is understood that the analysis methods of pivoting torque for such valves and the impact of valve seat to pivoting torque are not clear in China’s nuclear power business, because such valves and valve seats produced by foreign enterprises. Based on the above background, this thesis has studied the analysis methods of pivoting torque for such valves and the impact of valve seat to pivoting torque. The main research work and the results obtained are as follows:(1) Compression mechanical properties, time effect of compression mechanical performance, friction performance and time effect of friction properties of two types of POM seat material have been tested, and the performance of different types of seat materials has been analyzed comparatively, and the seat material properties have been provided to numerical simulation. It has been found that the mechanical properties between two kinds of seat materials are a little different, and there is time effect of mechanical performance. The friction properties between two kinds of seat materials are almost consistent, and there is time effect of friction performance.(2) The finite element model of contact between the ball and seat has been established, pivoting torque for the valve and the impact of valve seat to pivoting torque have been calculated,and analysis methods of pivoting torque for the valve has been confirmed. The results show that, because of time effect of compression mechanical performance and friction properties, pivoting torque for the valve can increase with the extension of load time. Material properties and structural dimension of the seat affect the pivoting torque for the valve by influencing the force between the seat and ball. In the export side seat tightness condition, the affection to pivoting torque of structural dimension of the seat is main, and the influence to pivoting torque of material performance is limited; In the entrance side seat tightness condition, the influence to pivoting torque of both material performance and structural dimension of the seat are significant.(3) Test equipment and test methods for pivoting torque of the valve have been designed. By using the method of experimental test, pivoting torque and pre-tightening force of the valve have been tested. And the reliability of the numerical simulation has been verified. Test results show that, in the constant load conditions, there is time effect of pivoting torque for the valve, pivoting torque for the valve increasing with the extension of load time. Test results are closed to simulation results highly, which has testifies simulation results are accurate. The test equipment and test methods can be used to assess the reliability of spare seat, which is of great significance.更多还原