Fluid-Thermal-Solid Coupling Analysis Of Ultra-Supercritical Electric Gate Valve And Lightweight Research Of Valve Body Structure

As the contradiction between the expansion of my country’s electricity demand and environmental pollution is becoming increasingly significant,domestic power plants gradually expand the operation of clean and efficient large-capacity,high-parameter ultra-supercritical generating units.At present,most of the ultra-supercritical electric gate valves developed by the valve company through the traditional design methods have the disadvantages of heavy mass and large volume,which causes serious material waste and economic loss.In order to solve the above problems,this article takes the ultra-supercritical electric gate valve as the research object.Based on the fluid-heat-solid multi-field coupling simulation analysis of the gate valve,the research is carried out with the goal of lightening the valve body structure.The specific content is as follows:(1)The fluid-thermal-solid multi-field coupling theory of ultra-supercritical electric gate valve was studied.The solid model of the main pressure-bearing parts of the gate valve was established by using three-dimensional software,and the gate valve was simulated and analyzed by finite element through ANSYS Workbench.The flow characteristics of the fluid medium in the valve were revealed,and the stress and strain conditions of the gate valve under the coupling action of fluid,heat and solid multi-field were obtained.In the end,it was found that its strength and rigidity meet the requirements and there is a large margin,which provides optimization space for the lightweight design of the valve body structure.(2)The thickness of the valve body structure and the size of the ribs were used as design variables,the maximum strength and rigidity limits of the gate valve under given operating conditions,and the range of design variables were the constraints,and the minimum weight of the valve body structure was the lightweight goal.A mathematical model of the lightweight structure of the valve body was presented.The mathematical expression of the maximum equivalent stress and maximum deformation was achieved by establishing a proxy model,the sample data was obtained by using the optimal Latin hypercube design,and the quadratic response surface and Kriging proxy model were used to approximate the sample data.On this basis,the surrogate model with higher accuracy was selected to participate in the solution of the valve body lightweight mathematical model later.(3)The improved differential evolution algorithm was used to solve the lightweight mathematical model of the valve body structure.Under the premise of meeting the strength and stiffness requirements of the electric gate valve,the valve body wall thickness and the size of the ribs were adjusted to make the gate valve lightest.The results show that the weight of the lightweight structure is reduced by 446.62 kg,and the weight reduction ratio reaches 10.27%.The lightweight effect is more significant,which provides an effective way for the lightweight design of other types of valves.