DN350型楔形闸阀阀座在进口通入温度为545 ℃、压力为10.3 MPa的水时发生屈服失效。为解决此问题，建立有限元模型，运用单向流固耦合方法得到阀座的等效应力与总变形云图。结果表明：内腔流场压力增大使得出口阀座的卸荷槽处应力增大，导致屈服失效，出口阀座顶部向内凹陷;增加卸荷槽数量能够优化应力在阀座上的分布，增大阀座外径能够增加阀座的刚度并减小变形量;当卸荷槽数量为2时，出口阀座应力降低了57.97%,总变形降低了48.58%;增加阀座厚度能降低阀座应力，当阀座厚度增加量为15 mm时满足强度要求。优化后的阀座满足实际工况强度要求，该方法为类似结构的改进提供了参考。
The DN350 wedge gate valve seat yield failure occurs when the inlet water temperature is 545 ℃ and the pressure is 10.3 MPa. In order to solve this problem, the finite element model was established, and the equivalent stress and total deformation nephogram of the valve seat were obtained by using the unidirectional fluidsolid coupling method. The results show that the pressure in the inner cavity flow field increases，the stress in the unloading groove of the outlet valve seat increases, resulting in yield failure, and the top of the outlet valve seat is concave inward;the distribution of stress on the valve seat can be optimized by increasing the number of unloading grooves,the seat stiffness can be increased and the deformation can be reduced by increasing the outer diameter of the valve seat;when the number of unloading grooves is 2, the outlet valve seat stress is reduced by 57.97% and the total deformation is reduced by 48.58%;seat stress can be reduced by increasing seat thickness, and the strength meets the requirements when the valve seat thickness is increased by 15 mm. The optimized valve seat meets the requirements of the actual working condition strength.This method provides reference for the improvement of similar structures.
ZHAO Yingchang, HE Qingzhong, WANG Jia, WU Sheng, LIAO Boquan. Failure and Improvement of Wedge Double Gate Gate Valve Seat[J]. Machine Tool & Hydraulics,2021,49(5):150-155