Calculation Method of Heat Dissipation Coefficient of Tooth and Yoke Back of Air-cooled Turbogenerator

Abstract

The embodiments of the invention provide a calculation method for the heat dissipation coefficients of tooth parts and yoke back parts of air cooling turbo-generators. The method mainly provides a brand-new solution domain calculation model, including a new boundary condition determining method; based on the ventilation effect of a rotor, the method calculates the heat dissipation coefficients of the surfaces of stator teeth and the surface of a yoke back part and solves the problems of calculation distortion and the complexity, long duration and difficulty in convergence of electrical machine total flow field calculation; since the range of the solution domain of the electrical machine rotor is large, only the fluid field thereof is calculated and the temperature of an air outlet is calculated by using the analytic method. No matter whether total flow field coupling is used or only the fluid field of the rotor is calculated, the heat dissipation coefficient of the yoke back part is difficult to determine; through direct calculation of finite elements, the new method can calculate the heat coefficients of tooth crests and the yoke back part more accurately; the accuracy of calculation of temperature rise of large electrical machine stators is improved and calculation results are accurate.

Description

technical field [0001] The invention relates to the technical field of turbogenerators, in particular to a method for calculating heat dissipation coefficients of teeth and yoke backs of air-cooled turbogenerators. Background technique [0002] During the actual operation of large air-cooled turbogenerators, the design, manufacture and operation departments are particularly concerned about the temperature of the stator winding and iron core. Therefore, engineering and scientific circles put forward a lot of research work on the theory and method of air-cooled turbogenerator. When calculating the stator temperature field of the turbogenerator, the heat dissipation coefficient of the tooth top and the heat dissipation coefficient of the yoke back have a great influence on the temperature rise of the motor stator, and the air flow and heat transfer in the air gap are carried out under very complicated conditions. [0003] The heat dissipation coefficient of the addendum of the...

AI Technical Summary

Problems solved by technology

Because the air inlet and tooth top of the radial ventilation groove of the stator are affected by the air gap air flow and heat transfer, the wind direction will suddenly change, resulting in turbulent flow; the air outlet of the radial ventilation groove of the stator is affected by the yoke back and the casing, and its flow direction is irregular

[0004] At present, in the research work on the stator temperature field of air-cooled turbogenerator, the typical analysis methods are usually thermal circuit method, heat conduction equation plus heat dissipation boundary condition or fluid-solid coupling mathematical model plus heat dissipation boundary condition. These methods are used in the calculation of air-cooled generator In the stator temperature field, the heat dissipation coefficient of the teeth or the back surface of the yoke is given artificially or based on design experience, which more or less makes the calculation model inaccurate, which affects the calculation accuracy, and has a negative impact on the design and operation of the generator. influences

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