Study On Cooling And Heat Transfer About Electrical Transmission System Of Wheeled Vehicle

As for high power hybrid electric vehicles, because of the power flow and heat flow is complex, and the amount of heating of the heat source component is high, which put forward higher requirements about thermal management of power system. The target of the research about the thermal management is how to play the energy-saving advantages of hybrid system under the normal operation of the high power hybrid vehicle.In this article, take an electrical transmission for specialty vehicles as research objects. Establishing heat calculation model of the thermal source, calculating the heat of the themal source under four kinds of typical working conditions, designing the high and low temperature circulation loop. According to the simulation results of the 3-D temperature field of the hub motor, taking maximum calorific effect of vehile value under various conditions as a reference point, calculating the needed cooling air and liquid cooling parameters. Finally, selecting the fan and the pump according to the maximum needed cooling airflow and cooling liquid flow.The internal structure of the hub motor is simplified, and the 3D model of the motor is established. In addition, establishing calculation model of motor copper loss, calculation model of iron loss, calculation model of rotor current loss, calculation model of physical parameters about equivalent insulator, calculation model of the coefficient of heat transfer on the end and calculation model of the equivalent heat transfer coefficient of air gap between stator and rotor. For the case of the maximum heat of the motor when the vehicle is in normal driving, off-road driving or climbing driving conditions, analyzing the temperature fields in the hub motor by using CFX software when inlet water temperature is different under different operating conditions. According to the simulation results, we can test whether the design of low temperature circulation loop of the cooling system is right.Establishing the one-dimensional simulation model of cooling system of the vehicle by KULI software. Calculating the heat dissipation of each heat source component under the maximum heat source of different conditions. According to the simulation results, we can verify whether the designed cooling system is right.Finally, building a test-bed, and the experimental study is carried out on the cooling system components. Testing the actual heat transfer performance of the corrugated fin type radiator and the maximum temperature of the inner winding of the hub motor when it simulates the vehicle at 120km/h speed.