CFD Calculationand Optimization Of The Generator Coolingair Flow

With the continuous development of hydropower technology in china, it is increasing emphasis on the construction of hydropower. Over years a number of major hydropower projects were established, the unit capacity of generator also increased. Followed, the heat load of generator is corresponding increasing, which leads to the temperature of various parts of generator increasing, and affect motor life and reliability, so the research for the generator ventilation becoming increasingly important, has become one of the most important problem for the generator design process. In the application process works for generator group, the air ventilation system is well received because of simple structure, easy operation and maintenance, operation and high reliability. The quality of the ventilation system will directly affect the efficiency of generation, and inextricably linked to security and stability of the generator. So it is vitally important to the design of ventilation systems. The designer of the electrical structure must be concern about that, if wind road is smooth and reduce the resistance of the local structure of generator and improve heat dissipation. As commercial CFD software and computer technology rapid developing, it is possible to explore and validate design through a large number of calculations and analysis.Steady flow inner the generator air cooling system was simulated using fluid simulation software Fluent / Gambit. Firstly, software for 3D modeling UGNX4.0 was used to model the flow, and then the grid was made by Gambit imported from Parasolid. After this, the grid was imported to Fluent, standardκ-εturbulence model, SIMPLE pressure correction algorithm and multi-reference system model are adapted to numerically simulate the inner flow field of the generator cooling system model. Then, the characteristics of the pressure and velocity distribution are analyzed. At last, the drag coefficient and thermal coefficient of the local structure is calculated according to the result of the simulation. Drag coefficient and thermal coefficient is selected as the basis for evaluation for the ventilation cooling effect. Because of the overall flow field model for large ventilation channel structure for small in the case, some reasonable and effective simplifications has been done in the modeling and meshing process, the calculation of the flow field is divided into two domains, and by iterative calculation to ensure the continuity of the flow field. The data in the calculation of flow field was used to calculate drag coefficient and thermal coefficient of local structure, by changing the size and structure of ventilation to improve its internal flow field, and compare with the drag coefficient and the thermal coefficient of different structural ventilations, get corresponding conclusions...