| With the deepening of oilfield development,the working conditions and parameters of oil wells are more complex and diverse.As one of the main tools of oilfield exploitation,screw pump has a large difference in working parameters,such as pressure and flow rate,in order to meet the needs of different well depth and liquid production.In the detection of screw pump performance,the screw pump performance test platform on the pressure regulator can adjust the large pressure difference and wide flow.The purpose of this paper is to study a kind of pressure regulating valve,so that it can achieve the pressure regulating range of 1-15MPa in the flow range of 50-300m~3/d,and has a certain precision and stable regulating performance.Based on the analysis of the working principle and structural characteristics of the general pressure regulating valve,the driving mode,throttling form and the overall structure of the pressure regulating valve designed in this paper are designed.Open different forms of throttling grooves upward on the spool shaft,choose the hydraulic drive mode,by changing the relative position of the spool and valve sleeve to change the length of the throttling groove and then adjust the pressure.A preliminary three-dimensional model of the pressure regulating valve with straight groove spool was established by using Solid Works software,and imported into Fluent simulation software.The fluid domain model was extracted and its structure was simplified.According to the linear change of the fluid domain after the movement of the valve core,the fluid simulation analysis was carried out by using the layering dynamic grid technology,and the corresponding curves of the pressure and the valve core closing stroke,the corresponding curves of the pressure change rate and the valve core closing stroke,and the corresponding curves of the valve core control distance and the flow were obtained within the designed flow range.By analyzing the effect of pressure flow regulation on this structure pressure regulating valve,it can be seen that the designed range of pressure regulation cannot be reached within the range of designed flow and adjustment accuracy.The throttle groove is optimized into a spiral groove with different pitch,pitch in the range of 80-200mm,the structure of the pressure regulating valve using the same analysis method as the straight groove spool pressure regulating valve,the structure of the pressure regulating valve in part of the design flow range to reach the design of the pressure regulating range.In view of the situation that the minimum pressure of the regulating valve of the spiral groove spool structure with a pitch of 80mm fails to reach the designed minimum pressure at the large flow rate,two symmetrical 150mm auxiliary spiral grooves are designed at the inlet of the spiral groove with this pitch.As the first optimization plan,simulation analysis shows that,Scheme one spiral groove pressure regulating valve in the design flow,adjustment accuracy range can achieve the design of pressure adjustment range,but part of the spool does not participate in the work,and can not ensure the uniformity of the valve spool to flow adjustment distance.On the basis of scheme 1,the side length of equilateral triangle groove at the outlet end of spiral groove is increased from 1mm to 3mm.As the optimization scheme 2,the simulation analysis shows that spiral groove pressure regulating valve in scheme 2 can achieve the designed pressure regulating range within the range of designed flow rate and adjustment precision,and the spool is fully involved in the work,and the uniformity of the valve spool to the flow regulating distance is ensured.Meet the design requirements. |
