稳压器喷淋阀碟簧受力分析及其结构优化

Disc spring force analysis and structure optimization of pressurizer spray valve

为解决稳压器喷淋阀在运行过程中出现的密封环磨损及碟簧断裂问题,以某核电站稳压器喷淋阀为例,对密封失效情况下碟簧的受力情况进行了仿真分析、实验研究及优化改进。首先,利用数值模拟方法搭建了去除密封环的喷淋阀流道模型,分析了不同压差下喷淋阀流场变化以及碟簧受力情况;然后,采用二维模拟得到了碟簧被挤压的临界压差,并利用相关实验对模拟数据进行了验证;最后,针对碟簧两侧压差过大问题进行了结构优化,并采用数值计算进行了验证。研究结果表明:在密封失效的情况下,碟簧两侧压差接近进出口压差,当碟簧两侧压差超过0.24 MPa时,碟簧会被挤压并脱离阀体;正常工况下,碟簧也会出现因两侧压差较大而脱离阀体的现象,说明这是导致碟簧往复运动失效的原因之一,而采用波形弹簧代替碟簧可有效解决这一问题。该研究结果对稳压器喷淋阀结构设计具有一定的指导意义。

In order to solve seal ring abrasion and disc spring fracture of pressurizer spray valve during operation,taking a pressurizer spray valve in a nuclear power plant as an example,simulation analysis,experimental research,and optimization improvement were conducted on the stress distribution of the disc spring under seal failure.Firstly,a flow channel model of the spray valve with removed seal ring was established by the numerical simulation method.The flow field changes and the stress distribution on the disc spring of the spray valve under different pressure and difference conditions were analyzed.Then,the critical pressure difference of the disc spring being squeezed was obtained by two-dimensional simulation and verified by relevant experiment.Finally,a structural optimization was proposed to solve the problem of excessive pressure difference between the two sides of the disc spring,and numerical calculation was performed to verify it.The research results indicate that in the case of seal failure,the pressure difference on two sides of the disc spring is close to the pressure difference between the inlet and outlet.When the pressure difference on two sides of the disc spring exceeds 0.24 MPa,the disc spring can be squeezed out of the valve body.Under normal working conditions,there can also be a large pressure difference on both sides of the disc spring,causing it to detach from the valve body.It is determined that it is one of the reasons for the failure of the disc spring s reciprocating motion and the problem can be effectively solved by using a wave spring instead of disk spring.The research results have certain guiding significance for the structural design of pressurizer spray valve.