Optimization on airflow distribution for anti-condensation of high-voltage switchgear using CFD method

Abstract

High-voltage switchgear is indispensable for power system. Condensation of the switchgear occurs frequently due to water vapor infiltration and water accumulation in cable trench, which may cause large-scale blackout of the power system. Effective dehumidification measures are crucial to safe and stable operation of the switchgear. In this paper, an air-conditioning based dry-air dehumidification measure is proposed for anti-condensation of the switchgear. Different airflow distributions are studied by numerical simulation of the thermal-humidity environment within the switchgear. Results show that the performance of the proposed dehumidification system is satisfactory. The switchgear wall temperature can be up to 7.6 °C higher than the return air dew point temperature, and the moisture content differences between the supply and return air can be more than 3.4 g/kg. Besides, some optimization measures for improving the dehumidification effect are proposed. After the optimization of the airflow distribution, the relative humidity and the temperature of the return air are reduced by 3.3% and 1.3 °C, respectively.