Performance Study On Flow And Heat Transfer In Staggered Finned Water Cooling Radiator

In recent years, with the rapid development of rail transit and high speed rail, power electronic equipment is developing towards the direction of high performance, superpower and miniaturization. This phenomenon leads to its equivalent heat flux dramatically increased so that it uses a traditional air cooled or water cooled cooling solution is unable to meet the cooling requirements. In radiating field of superpower power electronic equipment, staggered radiator attracts more and more attention from people because of its excellent heat transfer performance.Based on the structure characteristic of the staggered finned water cooling radiator in the EMU rectifier, the paper analyses the radiator by numerical simulation. The main works and conclusions in this paper are as follows:(1) Numerical simulation is used on plate finned, interrupted finned and staggered finned radiator with different mass flow rate. The results of numerical calculation show that the staggered finned radiator has excellent heat transfer performance, it appropriates for radiating field of superpower power electronic equipment, and this radiator can also bring a lot of resistance loss at the same time. With poor transfer performance, plate fin and interrupted fin radiator can't be applied to the field of superpower power electronic equipment.(2) In terms of the fluid tendency of the mass flow rate of three radiator, field synergy theory is brought in this problem, and from the viewpoint of synergy degree between velocity field and temperature gradient field, the inner mechanism of the radiator heat transfer performance is analyzed. It shows that the increase of fluid flow velocity can bring down field synergy degree for the same model. On the other hand, to the same velocity, the model with strong disturbance has high field synergy degree and excellent heat transfer performance.(3) The influence of flow and heat transfer brought by The structure parameters on staggered radiator has been researched by control variable method, and the intrinsic factor has been analyzed. The width and height of fluid channel and the gap length between two rows of fins have great influence on radiator performance. The effects of these parameters are concentrates on the flow velocity, disturbance degree of flow and heat transfer areas. These three factors have a large effect on performance of staggered radiator.(4) When the fluid flow in the radiator, the velocity distribution of the fluid in the radiator depends on overall layout of fins, and it affects the temperature uniformity of the heating surface of the radiator. Optimizing structural of radiator is improved in the aspect of uniform temperature distribution. The problem of low uniform temperature can be solved by adding fins to the radiator at each end.(5) The thick boundary layer appeared at rectangular channel corner. Optimizing structural of radiator is improved in the aspect of boundary layer. The boundary layer can be thinned by inverted fillet treatment.