Remaining Life Prediction And Feasibility Analysis Of Power End Crankshaft Of Mud Pump For Remanufacturing

Mud pump is a key oil production equipment,which plays an important role in the development of the oil industry.In recent years,decommissioned mud pumps have increased significantly.Remanufacturing of decommissioned mud pumps can reduce energy consumption and environmental pollution,which matches the goal of “carbon neutralization and carbon peak”,and has great economic potential.However,for the remanufacturing of the retired mechanical parts,the remaining useful life evaluation and Feasibility Analysis are very important,which directly affects the value,quality and strategy of its remanufacturing.Therefore,it is significant to carry out research on the remaining life prediction and feasibility analysis of the crankshaft for the decommissioned mud pumps.In this thesis,the remaining useful life before remanufacturing of the power end crankshaft for the decommissioned mud pump is studied by dynamic simulation,finite element analysis and fatigue analysis.The remanufacturing feasibility is evaluated by the comprehensive evaluation method.The main research contents are as follows:Firstly,the kinematic and dynamic mathematical models of the mud pump power end are established,and the kinematic and dynamic analysis are carried out for its key parts,such as crankshaft,connecting rod,piston,and crosshead,which provides references for the subsequent simulation verification.Secondly,the rigid multibody dynamics model and the rigid-flexible coupling dynamics model of the power end system are established respectively,and the dynamic simulation is implemented to obtain the motion regularity and force data of the key parts.The results are compared with that of the theoretical one to verify the correctness of the simulation.The rigid-flexible coupling dynamic simulation provides the basis for the crankshaft life evaluation.Then,based on the results of rigid-flexible coupling dynamics simulation and the modal analysis,the stress-time history data of the crankshaft are obtained by using the virtual fatigue durability analysis module,and the fatigue life of the crankshaft is calculated by NCODE,and then the remaining useful life of crankshaft before remanufacturing is obtained considering its service life.Finally,the remanufacturing feasibility evaluation model is established for the crankshaft of the decommissioned mud pump based on the technical,economic and environmental factors,and the weights of each factor are determined by Analytic Hierarchy Process(AHP).According to the existing evaluation criteria of the remanufacturing feasibility,a complete comprehensive evaluation system of remanufacturing feasibility is built,and the remanufacturing feasibility of the crankshaft is evaluated.The results show that the power end crankshaft of the decommissioned mud pump studied in this paper can be remanufactured.