活塞式调流调压阀流动特性研究

An Analysis of Flow Characteristics of Flow and Pressure Regulating Valve with Piston Sleeves

以DN200活塞式调流调压阀为研究对象,基于Fluent软件,采用Realizable k-ε湍流模型,研究了不同开度下阀内三维流动特性。结果表明:节流孔处存在压力梯度突变,节流孔进口至出口压力先降低后逐渐恢复。同时,下游管道近壁区域存在对称的回流区,阀内出现不同强度的涡流。随着开度逐渐增大,下游管道壁面附近旋涡向上游侧移动,阀内旋涡强度逐渐减弱。此外,节流孔下游形成对冲射流,套筒中心位置出现"低速空穴区"。随着开度逐渐增大,节流孔内最大流速逐渐增大,射流向下游延伸范围逐渐扩大。节流孔壁面附近存在不对称分布的高涡量区域,附壁剪切旋涡形成区域是空化产生的潜在位置。调流调压阀具有线性度较好的流量特性,在小开度下消能降压效果明显。

Taking the flow and pressure regulating valve with piston sleeve of DN200 type as the research object,based on FLUENT and Realizable k-εturbulence model,the three-dimensional flow characteristics in the valve with different opening are studied.The results show that there is a sudden change of pressure gradient at the orifice,and the pressure in the orifice firstly decreases and then gradually recovers from the inlet to the outlet.At the same time,there is a symmetrical circumfluence area near the wall of the downstream pipeline,and eddies of different strength appear in the valve.With the increase in opening,the vortex near the downstream pipe wall moves to the upstream,and the strength of vortex in the valve decreases gradually.In addition,a jet forms at the downstream of the orifice,and a“low-speed cavity area”appears at the center of the sleeve.With the increase in the opening,the maximum velocity in the orifice increases,and the jet extends to the downstream further.There is a high vorticity region with asymmetric distribution near the wall of the orifice,and the region with wall attached vortex is the potential location of cavitation.The linearity of flow characteristic is superior and the effect of energy dissipation and depressurization is obvious at small openings.