Introduction  It is an inevitable trend for the current power grid construction in the urban area in domestic to adopt a compact indoor layout for the whole house in the power grid project. However, how to dissipate a large amount of heat emitted by indoor equipment without adversely affecting the surrounding environment is an issue worthy of in-depth study. As a cost-effective, noise-free ventilation scheme, natural ventilation should be given a priority. In order to study the influence of different schemes on natural ventilation of the indoor pre-insertion resistor circuit when other conditions remain unchanged, by changing the position and form of the ventilators, this paper discusses the cooling method of an indoor pre-insertion resistor circuit field in a VSC-HVDC converter substation in Guangzhou.

  Method  Based on CFD, the temperature field and velocity field of the air flow in the factory building under the conditions of using streamline ventilator and thin ventilator were simulated respectively.

  Result  The result of the simulation show that the natural ventilation scheme is feasible. It can also be verified that the streamlined ventilator increases the effective ventilation area, optimizes the indoor air flow field, reduces the internal ambient temperature of the indoor DC field by about 2 °C more compared with the thin ventilator, and can achieve a better overall cooling effect under the same ambient temperature.

  Conclusion  It can be concluded that natural ventilation of the indoor pre-insertion resistor circuit is proved to be feasible, and heat dissipation effect of the streamlined ventilator is better than that of the thin ventilator in a specific environment. This project can provide reference and basis for similar VSC-HVDC converter substation in the future.