Numerical Calculation Of Fluid Field And Thermal Field For Large Hydro-generator

Whether thermal field of hydro-generator is rational or not affects its security directly, however the thermal field lies on the distributions of cooling material and electromagnetic losses. In this paper, to gain accurate thermal field, the rotary fluid field is calculated based on the fluid dynamics theory, and then the fluid field and thermal field of stator are calculated through conjugate heat transfer method.Based on the analysis on ventilation system, the calculation region of rotary fluid field is plotted out and meshed in unstructured grid. According to the characteristic of cooling material, basic assumption and boundary condition are presented. The calculation is performed by finite volume method, and fluid field distribution is obtained. In order to finding more perfect fluid field parameter, the fluid fields of different rotor positions and various inlet velocities are calculated. And the fluid fields are respectively calculated and analyzed by compressible and incompressible model.In addition, according to the structure characteristic of stator, the 3D calculation region of fluid field and thermal field is plotted out and meshed in structured grid, and 3D mathematical models are established. Based on the analysis on cooling process of stator, basic assumption and boundary condition are presented. The calculation is performed by finite volume method and partial adaptive grid technique. The results of calculation are compared respectively with the results of traditional method and measured values, which illuminates the veracity of conjugate method. The surface heat transfer coefficient is obtained, and the heat transfer process is shown accurately by numerical method. And the affection of cooling air quantity to stator thermal field is analyzed.