Transient pressure characteristics in a pressure regulating system by using 1-D analytic valve modeling

Abstract

Typically, a Pressure Control Valve (PCV) system is constructed with 3 to 4 PCV lines in order to prepare for both a future demand increase and a continuous supply of power after an emergency shutdown of the operating line. However, some operation failure cases that do not follow the original design concepts of a PCV system have been reported in the field. In this study, an accurate 1-D PCV system numerical model was built and a 1-D compressible flow theory was introduced for analytic valve modeling to find solutions for this problem. Several numerical analyses were successfully performed to examine the generation and propagation characteristics of the transient pressure and to clarify the relationships between the transient pressure or surge wave and each factor or parameter relating to fluid dynamics behavior in a PCV system. The relationship between the transient pressure and other factors, such as the size of pipe and header linked after a PCV, the pipe size of the added components linked after the header, and the generation time of the transient pressure and influence of the Slam Shut Valve were investigated in detail. Finally, in order to reduce the strength of the transient pressure and to delay its propagation, this study demonstrates the benefit both of enlargement of the pipe linked to the component added after the PCV system, and the installation of a dissipation component between the operation line and the other lines.

Numerical simulation and structure improvement of double throttling in a high parameter pressure reducing valve

“…Cho et al (2007) derived a force balance equation and evaluated the pressure distribution and forces acting on the top and bottom planes of the valve plug. Some studies on transient numerical models of control valves were reported by Kerh et al (1997) and Shin et al (2008), which also have significance for engineering applications. Most researchers focus on the distribution of characteristics in the valve and the flow patterns.…”

Dynamic modeling and simulation of an integral bipropellant propulsion double-valve combined test system

“…As a component for reducing and stabilizing pressure in the fluid pipeline system, the PRR is widely researched [11][12][13][14][15][16][17][18][19][20][21][22][23] for its dynamic characteristics. However, many models for gas PRR adopt some assumptions such as isothermic [12,13], isentropic [14][15][16] and linearization [15] which do not strictly agree with reality.…”

“…Their pressure differential equations are usually obtained by taking the derivative of ideal gas state equation or isentropic equation and employing isothermal process assumption [12] or isentropic process assumption [15,16] rather than by deduction from the energy equation of compressible transient flow in one-dimensional (1D) conservative form. The final forms of these models depend too much on ideal gas state equation or isentropic equation; many models either do not give comprehensive consideration to roles of various chambers [12,13,15,16,21] (usually emphasize on simulating throttling and pressure stabilizing of valve spool but give little or inadequate consideration to roles of other chambers than high-and low-pressure chambers) or adopt pressure difference-based relationship between pressure and flow rate for valve spool and orifice throttling [15][16][17][18][19][20]. Moreover, there are some researches [21][22][23] on liquid PRR in the hydraulic system which use the method of bond graph and regard the fluids as incompressible flow.…”