Throttling Characteristics and Failure Analysis of High Pressure Throttle Valves based on Fluid-solid Coupling

Taking a used in field of fractured continental high pressure gas reservoir development in the Northeastern Sichuan wedge manual throttle valve as an example,investigated the relationship among throttle areas,pressure drop,velocity and throttle opening,and also established mathematical model which is concerned with throttle opening,fluid density,imported flow and pressure drop based on bernoulli's equation.The distribution of the flow field inside the throttle valve and the spool stress distribution under different conditions are compared and analyzed by using the workbench fluid-structure interaction numerical simulation method.The results suggest that the throttling ability decreases quickly with the increase of the degrees of opening in addition it decreases with the increase of fluid density and imported flow.The results suggest that in a certain degree of opening,because of the high speed flow of the valve cavity fluid,the connecting hole of value core stepped surface and pin occurs stress concentration,and the wedge guide surface appears obvious vortex generation which will cause the valve vibration leading to fracture failure;When the degrees of opening is small,the throttling valve works effectively and cause some problems frequently because of the high pressure impact effects of solid-phase fluid such as wedge faces assassination,block and so on.The results of the analysis are very consistent with the field value core failure situation.