Analysis And Calculation Of Fluid Field And Temperature Field For The Medium-sized High-voltage Motors In YKK Series

In the1990s, the medium-sized high-voltage motors in YKK Series weredesigned by our country, it has the advantages of high efficiency, energy saving,low noise, small vibration and reliable performance. It can drive the fan,compressor, water pumps, crushing machines, cutting machines and othermachinery, but also can be used as the prime mover in coal mines, industrialmachinery, power plants and various industrial and mining enterprises. Becauseof the complexity of the structure of closed type asynchronous motor,temperature rises always treated as the key issues need attention.The axial and radial mixing ventilation cooling method is applied to theYKK series medium high voltage asynchronous motor interior, radial ventilationducts distributed in the interior of the motor, the rotation of the rotor leads to thefluid flow in the ventilation groove inside becoming very complex. In the actualcalculation, the majority of people choose to simplify the flow of the fluid in theventilating ducts, this method is convenient in calculation, but reduces theaccuracy of the temperature field calculation, the result has larger deviationscompared with the actual situation.This paper analyzes the characteristics of the cooling system of the motor inYKK Series, according to the actual structure size of a YKK450-4、500kWmedium voltage asynchronous motor, sets out the physical model of fluid field ofwind path; analysis of the actual operation of the motor by using the theory offluid mechanics and heat transfer; gives the appropriate assumption and boundarycondition. Through the simulation calculation, the field distribution, pressurecontours and the flow distribution of each ventilation ditch can be obtained; thetemperature field inside the motor is calculated through the fluid field and temperature field coupling method. On the basis of it, change the relatedparameters in the ventilation channel steel, re-modeling of the ventilation channeland get the influence on temperature field distribution of the motor.The fluid field and temperature field distribution of the motor during steadyoperation is calculated accurately in this study, the rationality and accuracy ofcalculation model can be proved from the comparative analysis of simulationresults and experimental data. What’s more, the installation position of theventilation channel is improved in this paper. The theoretical basis of improvingthe heat dissipation performance of the motor can be obtained from the researchresults.