Research On Frequency Conversion Control Mechanical Reversing Pumping System And Dynamic Simulation And Optimization

Nowadays,as the difficulty of oil extraction continues to increase,oil fields have also put forward higher requirements for the performance of pumping units.According to practical experience,increasing the stroke and reducing the stroke of the pumping unit can effectively improve the performance of the pumping unit.Tower pumping unit,as the main force of long-stroke pumping unit,has become the core object of pumping unit research,and the reversing mechanism and balance device as key components are the main contents of current tower pumping unit.In this thesis,the design is based on the tower pumping unit.In view of the shortcomings of the current tower pumping units in different forms,combined with the oil field conditions,a structural scheme of the variable frequency control mechanical reversing pumping unit is proposed.The frequency conversion control mechanical reversing pumping unit adopts a mechanical reversing box,and the reversal is realized by a combination of a crank connecting rod mechanism and a gear transmission;a balance scheme combining counterweight balance and swing cylinder auxiliary balance is used;the motor is frequency-converted Optimize the control,so as to realize the active adjustment of the pumping unit balance and suspension point speed.Based on the structural scheme of the variable-frequency control mechanical reversing pumping unit,establish the kinematics simulation model of the ground equipment under the variable-frequency condition,the simulation model of the sucker rod string vibration and suspension load,and the output model of the swing cylinder auxiliary balance system to construct the pumping system The overall numerical simulation model of single degree of freedom and multiple degrees of freedom,the MATLAB simulation results of the suspension point indicator diagram,the suspension point motion law curve and the motor power curve are obtained.Based on the simulation model and data results,the corresponding design variables and constraints are clarified,and the minimum maximum crankshaft torque factor and the minimum root mean square of the motor output power are used as the objective functions to establish the size optimization model of the pumping unit transmission mechanism and the motor frequency conversion control.Optimize the model to obtain the overall optimization result of the pumping unit system.Based on the optimized simulation results of the system,a mechanical simulation model of the reversing mechanism and the tower is established.Considering the elastic foundation of the tower in practical applications,the finite element analysis is carried out respectively,and the overall design of the pumping unit is carried out according to the final analysis result.