Design And Temperature Field Research Of Linear Motor For Submersible Reciprocating Pump

The traditional rod oil production system has problems such as low efficiency,high energy consumption,and eccentric wear of the rod and tube.The rodless oil production system,which directly drives the reciprocating pump for oil pumping by a linear motor,can effectively improve these problems.Therefore,research on safe and reliable large thrust submersible linear motor is the development trend of oil production industry.Aiming at high thrust and high temperature and high pressure resistance,this thesis designs a submersible linear motor suitable for rodless oil production system,and focuses on the research on its temperature field,mainly including the following aspects:Firstly,the body design of the submersible linear motor is completed according to the technical requirements,and the electromagnetic field simulation of the motor is carried out.The simulation results show that the electromagnetic thrust generated by the motor can meet the requirements.In order to calculate the efficiency of the motor,the mechanism of various energy losses of the motor is expounded and calculated.Secondly,in order to determine whether the designed motor can work normally in a high-voltage environment,the structural strength simulation of the motor is carried out.The simulation results show that the deformation and stress of the main pressure-bearing parts of the motor are within the allowable range,and the motor can withstand external high-voltage environment.Then,the research on the characteristics of the motor temperature field variation under different working conditions is carried out.Using the energy loss of the motor obtained in the electromagnetic field simulation as the heat source,the two-dimensional temperature field model of the motor is established using Fluent software,and the transient temperature rise process of the motor and the influence of crude oil flow rate and ambient temperature on the steady-state temperature of the motor were analyzed.It was found that due to the relatively low heat exchange efficiency between the transformer oil and the casing,the steady-state temperature of the motor winding is close to the allowable limit value,and measures need to be taken to reduce the temperature rise of the motor.Finally,the temperature rise of the motor is controlled from two aspects of reducing the heat generated by the motor and increasing the heat dissipation of the motor.Under the premise of ensuring that the electromagnetic thrust of the motor meets the requirements,the copper loss of the winding is reduced by reducing the excitation current,thereby reducing the calorific value of the motor.In view of the relatively low heat exchange efficiency between the transformer oil and the casing,the heat dissipation of the motor is improved by optimizing the casing structure.After taking optimization measures,the steady-state temperature of the motor winding is reduced by 21.2%,which is much lower than the maximum working temperature of the winding.In order to verify the reliability of the simulation results,an experiment is carried out,and the simulation results are basically consistent with the test results,which proves the reliability of the submersible linear motor designed in this thesis.