The Numerical Simulation And Experiment Research On Lift Force And Recoil Effect Of Safety Valve

Spring safety valve is a self-acting valve,which discharges rated fluids depend on the lift force without any external force,so that the operating pressure would not exceed the specified value.The lift force means the opening force of the opening part during the safety valve overpressure relief process,which is composed of the valve core lift force and the disc holder lift force.The valve core lift force comes from the total fluid force of the valve core surface. the disc holder lift force comes from the total fluid force of the disc holder surface,which is called the recoil force. Thus it can be seen that,the valve core lift force and the disc holder lift force are important parts of the lift force,which are the key ensurance of the devices essential safety.The essence of studying the lift force and the recoil force is to study the essential safety of safety valve. This paper study the safety valve overpressure relief process through the numerical simulation and the experiment methods. The research contents are as follows:Firstly,the numerical simulation was further improved,including boundary details, limiting displacement settings, the new model measured sizes, grid partitioning and so on. The test results are showed that the 3D simulation is consistent with the sensor testing data.With the numerical simulationwas and the aerodynamics theory,the cause and change of the internal flow mechanism are quantitatively studied.Secondly,by using the experimental setup and the valve core new sensor,the valve core pressure,lift are successfully obtained,with which the recoil force is calculated. The relief valve interior steady flow field of moving parts is analyzed,by using the domain decomposition and paths analysis methods, and the force balance and the distribution of velocity and the stress characteristics of the paths in the interior and external flow field are studied too.Thirdly,through the comparison of the data of the disc holder existing or not, the influence of disc holder on safety valve performance is analyzed. Optimization design was carried out on the structure of disc holder,so that the safety valve could achieve better performance. The influences of disc holder on lift force and recoil force are also studied.Fourthly, the research showed that the breadth of sealing surface affects the safety valve performance, which has relations with the lift force and the recoil force.Fifth,by using the experimental setup and the new sensor,the valve core pressure,lift,lifting height are successfully obtained.With these test data,this paper studied relationship between lift and lifting height,this means using the lifting height data could estimates the lift data, the converse is also true,so that the indirect measurements of the lifting height and lift are realized.