Study On Lifting Performance Of Ellipse-like Type PCP

There are mainly single head and double head progressive cavity pump in oil field.The profile of the double-head progressive cavity pump is obtained by the equidistant curve of the swing line of the fixed rotor bone line outward.The shape line of the ellipse-like progressive cavity pump is formed by the straight line directly enveloping the ellipse-like rotor,and then the stator line is formed by the rotor enveloping the inward rolling method.The shape lines of the rotor are all directly enveloped,and no isometric curve is needed to obtain the profile,which avoids the phenomenon of bucking.In this paper,the flow area,sliding speed and lifting performance of the new type of ellipse-like progressive cavity pump are studied,which lays a foundation for the further research on the design,manufacture and application of this type of progressive cavity pump.According to the forming principle of the rotor profile of the elliptic type progressive cavity pump,the formula for calculating the theoretical area is obtained.Under the condition that the stator diameter of the progressive cavity pump is determined,the eccentricity directly affects the rotor section shape of the progressive cavity pump,and then affects the flow area of the progressive cavity pump.Through the calculation and analysis of the flow area under different eccentricity,the optimum range of eccentricity parameters is obtained.The analytical formula and the motion simulation model for the theoretical calculation of the relative sliding speed between fixed rotors are established,and the variation rules of the sliding speed are analyzed respectively.The finite element model of elliptic type progressive cavity pump was established by using ANSYS software according to the actual working condition,and the contact stress of sealing belt was calculated.According to the minimum contact stress criterion,determine the leakage location of the sealing belt.Taking this leak location as the study object,a large number of finite element simulation calculations were carried out to obtain the critical contact stress corresponding to different low pressure chamber pressure of the progressive cavity pump.The calculation method of lifting pressure is obtained by analyzing the pressure transfer law of screw pump.The lifting pressure of different series is calculated and compared with the conventional progressive cavity pump.Using the method of control variables,the finite element analysis was carried out for the lifting pressure of the elliptic type progressive cavity pump with different structural parameters.The critical contact stress of screw pump under the conditions of different eccentricity,initial interference and lead is calculated respectively and the variation rules of the lifting pressure and the above three structural parameters were obtained,and the influenceof the above three structural parameters on the lifting performance was analyzed.