固体颗粒物诱发溢流阀调压失效的作用机制

Functional mechanism of relief valve pressure maladjustment induced by solid particles

针对实际中出现的先导式溢流阀调压失效现象,运用FLUENT中的欧拉-欧拉多相流模型对溢流阀中含有均压槽的主阀配合间隙内流场进行液固两相流二维轴对称数值计算.研究发现:固体颗粒物在均压槽内有高度聚集现象,均压槽内贴近阀体壁面的半月形区域中固相体积分数最大值是进口的10倍左右,液流主流束和均压槽底部固相体积分数较低;当阀芯运动方向与间隙内压力梯度方向相反时,均压槽出口间隙将浸入高体积分数固相区,部分颗粒在压差作用下将嵌入均压槽出口后的间隙中,引起阀芯卡滞,进而诱发调压失效.

Aimed at the phenomenon of pressure maladjustment occurred practically in pilot-operated re- lief valve, the internal flow field in fitting gap of the main poppet of this valve with ring groove was calcu- lated numerically by using Eulerian-Eulerian multiphase flow model in software FLUENT for solid-liquid two-phase two-dimensional axisymmetric flow. The research results showed that the solid particles gather densely in ring groove. The volume fraction of solid particles around semilunar zone was ten times higher than that at inlet, but it was low near main stream and at bottom. When the direction of the spool motion reversed to that of pressure gradient, the outlet gap of the ring groove would submerse into the semilunar zone and partial particles would implant into the gap behind the ring groove, leading to spool sticking and inducing pressure maladjustment.