A Heat Dissipation Enhancement Measure for Transformer Based on Falling Film Flow

With the increase of electricity demand, the overheating phenomenon of the oil-immersed transformer in operation is increasing. In view of the insufficient heat dissipation capacity of the existing ONAN transformer, it is essential to research the heat dissipation enhancement measures of the transformer. The heat transfer process of oil-immersed transformer is firstly analyzed, and the air-side heat transfer coefficient of radiator (hair) is pointed out to be the crucial parameter limiting the heat dissipation capacity of the ONAN transformer. Then, a two-dimensional axisymmetric thermal-fluid coupling model of transformer is established to explore the relationship between hair and transformer internal temperature, and obtain the better hair. Finally, a heat dissipation enhancement measure based on falling film flow is put forward in this paper, and the simulation experiment platform is built to obtain the hair. The results show that the falling film flow measure can achieve the better hair, reduce the top-oil temperature and the hot-spot temperature of the transformer effectively. The proposal of the heat dissipation enhancement measure based on falling film flow can provide a new solution to meet the overload operation requirements of transformers and reduce the probability of ONAN transformer overheating.