Numerical Simulation of Natural Ventilation in Main Transformer Room of Indoor Substation

In the split main transformer room of the indoor substation studied in this paper, the heat dissipation area of the transformer main body and part of the convection pipeline accounts for approximately 5.4% of the total heat dissipation area, with the outdoor radiator responsible for releasing most of the heat. Compared with the integrated main transformer room of indoor substations, the split-type design features a smaller building size and lower ventilation energy consumption, thus it is widely applied in urban areas. This study employs computational fluid dynamics (CFD) simulation to investigate the natural ventilation and heat dissipation performance of the main transformer room in a 110 kV indoor substation located in the Shijiazhuang area. A thermal imager is used to capture the surface temperature distribution of the main transformer, and the data is fitted into a polynomial function. During the numerical simulation, the surface temperature of the main transformer is set using a user-defined function (UDF), and the total heat dissipation of each heat-dissipating surface of the transformer is extracted via FLUENT(Ansys 2024 R2) software as the basis for evaluating the ventilation and heat dissipation effectiveness. The effects of different ventilation window sizes on the natural ventilation heat dissipation and air change rate of the indoor substation’s main transformer room under thermal pressure are compared. The feasibility of this numerical simulation method is verified through experimental measurements and theoretical analysis.