Research on local cold airflow supply methods in designing cooling solutions for longwall faces in underground coal mines

Tóm tắt

Workers in underground coal mines are always at risk of heat shock due to high temperatures and narrow spaces. To reduce the temperature in the longwall faces, some mines have used air conditioners to increase the cooling capacity, creating a better working environment for miners. However, the current method has wasted significant cooling capacity for short-distance tunnels while providing a negligible cooling effect for remote longwall face areas. To resolve this problem, the cooling solution using cold airflow distributed at local points has been studied. The essence of this solution is to direct all cold air from the air conditioner into the air duct and only supply it to the necessary locations. The cold airflow from the air duct is sprayed into the main airflow to reduce the temperature locally for each miner's working position. The cold airflow can be actively adjusted to correspond to the cooling zone in the tunnel's upper, middle, or lower part and longwall face. The effect achieved is to reduce cold air loss, increase the air conditioner's life by installing it in a favorable environment, and directing the cold airflow through the duct to the necessary place. An experimental study using the airflow from the air compressor also reduced 1.10C over a local range of 5 m in the LC-I-9-24B longwall face at the Nam Mau coal mine. This clarifies the applicability of cold airflow at local points and introduces the direction of improving the cooling efficiency of air conditioners in underground coal mines