Research On Leakage Mechanism Of All Metal Progressive Cavity Pump

All-metal progressive cavity pump is a new type of PCP, the stator and rotor are made ofspecial steel material and assembled with reasonable clearance fit, which has excellent heatresistance, wear-resistance, corrosion resistance, adaptability to high viscosity, and has asignificant advantage in the heavy oil recovery. Because leakage is the main factor affectingthe efficiency and performance of the all-metal progressive cavity pump, the systematicresearch on leakage mechanism is significant to improve and enhance the lifting performanceof the all-metal progressive cavity pump.In this paper, the working principle and the linetype theory of all-metal progressivecavity pump were analyzed and summarized. The linetype characteristics of PCP wereanalyzed by MATLAB programming. The optimal selection of linetype was carried out andthe main structural parameters were determined. The motion law of rotor was analysisedthrough the theory study, and the three-dimensional solid model of the all-metal progressivecavity pump was established by SolidWorks. Then, the motion simulation of all-metal PCPwas analysised by COSMOS/Motion, the trajectory and velocity curve of each point on therotor and the relative sliding velocity of the rotor and stator were got.The generation and transfer rules of pressure of all-metal PCP in the ideal state and theactual state were analysised. The fluid dynamics analysis software FLUENT was used toanalysis the hydraulic distribution in the internal chamber, and the distribution and transferlaws of hydraulic in the internal chamber were got. By the contact analysis of ANSYS, thecontact characteristics of the rotor and the stator under the action of hydraulic pressure wereresearched, and the influences of different temperature and clearance on the contact stresswere analysised.The leakage formula of the all-metal PCP was deduced through the fundamental theoryof the gap flow and the characteristics of two kinds of gap structure. The fluid dynamics analysis model was established, and the influences of different pressure, viscosity andclearance on the leakage were separately analysised. The reasonable value range of clearancewas got through comprehensively considering the influence of the clearance and contact stresson the leakage.