Transient Analysis of a Spring-Loaded Pressure Safety Valve Using Computational Fluid Dynamics (CFD)

Abstract

A spring-loaded pressure safety valve (PSV) is a key device used to protect pressure vessels and systems. This paper developed a three-dimensional computational fluid dynamics (CFD) model in combination with a dynamics equation to study the fluid characteristics and dynamic behavior of a spring-loaded PSV. The CFD model, which includes unsteady analysis and a moving mesh technique, was developed to predict the flow field through the valve and calculate the flow force acting on the disk versus time. To overcome the limitation that the moving mesh technique in the commercial software program ANSYS CFX (Version 11.0, ANSYS, Inc., USA) cannot handle complex configurations in most applications, some novel techniques of mesh generation and modeling were used to ensure that the valve disk can move upward and downward successfully without negative mesh error. Subsequently, several constant inlet pressure loads were applied to the developed model. Response parameters, including the displacement of the disk, mass flow through the valve, and fluid force applied on the disk, were obtained and compared with the study of the behavior of the PSV under different overpressure conditions. In addition, the modeling approach could be useful for valve designers attempting to optimize spring-loaded PSVs.

Dynamic behaviour of direct spring loaded pressure relief valves: III valves in liquid service

“…They performed linear and non-linear stability analyses and found parameter ranges where flutter-induced limit cycles turn into chattering motion through grazing bifurcations. At the opposite end of the spectrum of computational complexity, Song et al (2010), produced a 3D CFD model with deforming mesh for investigating the precise flow physics of transient valve motion at instability. Moussou et al (2010) investigated both static and dynamic instabilities through a mixture of analytical calculations, CFD and experiments.…”

A CFD analysis of the dynamics of a direct-operated safety relief valve mounted on a pressure vessel

“…In this paper, the dynamic analysis of an individual direct-operated SRV by the authors [22,23] is extended with similar approaches involving DDM (domain decomposition method), domain interface, moving grid and CEL (CFX Expression Language) used previously [22] utilized again. Differently and importantly, instead of giving a static pressure condition at the inlet of the valve, a pressure vessel is added to provide a relatively real condition, which means that this paper presents an investigation of a simple system including a pressure vessel and a direct-operated SRV rather than a SRV itself.…”

Analysis on the Performance Improvement of Reciprocating Pump with Variable Stiffness Valve using CFD

“…When the pressure difference is enough to overcome the spring preload and gravity of the valve disc, the suction valve opens. In this process, the valve disc is subjected to the following forces: fluid force produced by the pressure difference acting on its surface, gravity, fluid resistance (This force was eventually omitted), spring force (Qian et al, 2014;Beune et al, 2012;Song et al, 2010). The differential equation of motion of valve disc is as follows:…”

“…With the rapid development of CFD technique, many scholars have studied the dynamic opening process of the valve by internal visual simulation. Such as, Song et al (2010) established a three-dimensional CFD model to study the fluid characteristics and dynamic behavior of a spring-loaded pressure safety valve. Moreover, Beune et al (2012) developed a multi-mesh numerical valve model to analyze the opening characteristic of high pressure safety.…”