Multi-objective Design Optimization of a Pressure Safety Valve for Raped Opening and Reclosing

A pressure safety valve (PSV) is widely used to open and relieve excess pressure from a pressure vessel/system. The rapid opening and reliable reclosing of a PSV are of great importance and are strongly determined by the coupling effect of the compressed spring and the fluid flow through the chamber region, which is mainly determined by the shape and the size of the disc and adjusting ring. In this paper, a multi-objective design optimization of a PSV is presented to trade-off the rapid opening and the reliable reclosing. The opening and reclosing operation is firstly estimated by comparing the spring force and the fluid forces, respectively, where flow force is obtained by using three-dimensional (3-D) steady CFD simulation. Then, radial basis function (RBF) models are developed to approximate the two objective functions. A multi-objective optimization algorithm is then utilized to search the optimal design. Additionally, a global sensitivity analysis (GSA) is carried out to identify the most important variables for the optimal design. The results show the influence of design variables on the opening and reclosing of the PSV, and give the optimal structure with desirable function. The analysis and optimization method used also shows a great potential to assist engineers in the preliminary design of PSVs, especially when the physical experiments are difficult to implement.