Simulation and analysis of temperature field of the discrete cooling system transformer based on FLUENT

Discrete cooling system transformer is prone to be chosen during the construction process of underground transformer substation in major cities, while there are few researches on the radiation of discrete cooling system transformer. In this paper, ICEM CFD software is applied to establish the simplified model of discrete transformer based on the theoretical analysis of thermal behavior of normal one-piece transformer. To simplify the model, winding and iron core should be considered as main heat source in the modeling process. In this model, the transformer is considered as a whole, the Boussinesq model in Fluent is used to simulate the thermal field and oil flow field inside of transformer, and the variation of physical characteristics of transformer with temperature is taken into account. After that, the software CFD-Post is applied to optimize the calculation result and obtain the nephogram of temperature and velocity flow diagram. From the analysis of thermal filed, the temperature and specific position of hot-point are determined, this provides the basis for hot-point measurement of transformer. What's more, the variation of thermal field of discrete cooling system transformer with different external temperature is get by changing the external environment condition, and the thermal field of it is compared with the one of normal one-piece transformer, so the superiority of discrete cooling system in practical application system is proved.