Experimental Research On Fluid Heat Transfer Characteristics Of Submersible Motor

For the special structure and working environment of electrical submersiblemotor, a motor model considering the coupling effect of temperature field and liquidfield was established, the calculation method for equivalent coefficient of heattransfer and thermal conductivity for the major components of the motor was given,the impact law for temperature field was obtained. The inherent laws of, the complexliquid flow in the gap and inside hole of shaft, and, the interaction of liquid flow andthe coupling heat transfer between stator and rotor, were revealed; the globalsteady-state temperature distribution of the motor was given, the impact law of thecooling of stator and rotor against the temperature distribution was studiedconsidering the flow rate and flow pattern of the raw oil in the tube of the outer wallof the motor.The shortage of the current test device and method for electrical submersiblemotor was analyzed; a new test platform with two layers was developed, whichholding the dynamometer and the tested motor being mounted and running under thedynamometer; by setting the external water cycle system and simulating theinfluence of oil level of well against the cooling effect, the actual running status ofelectrical submersible motor was truly simulated. Based on theoretical calculations,one set of sample electrical submersible motor for testing YQY143-40kW wasdesigned and manufactured; a number of thermocouples were embedded formeasuring the temperature rise of the motor. Through the test of the sample motorand comparison with the analysis test data, the accuracy of the theoreticalcalculations and the validity of testing system and simulation sample motor areverified.Various losses cause the temperature increases when the electrical submersiblemotor running, the heat scattered mainly by the stream of the well liquid of theexternal wall of the motor. Through the rational matching of motor diameter,reducing the inner diameter of the well casing and increasing the displacement of well to promote the flowage of the liquid of well, the heat dissipation of the motor isimproved. By improving existing motor structure, oil impeller is added to the shaft topromote the oil-filling cycle inside the motor and improve the heat dissipation.