Some Effects on the Temperature of the Mine Air at the Heading Face

Currently, with the increase in mining output leading to deeper mining levels, the volume of heading face serving production has also increased. The thermal environment tends to worsen when digging deep due to the geothermal's effect, which increases the air temperature at the heading face. According to QCVN01/2011-BCT, the temperature at the heading face is not allowed to exceed 30 degrees C. To ensure this, in Vietnam today, mainly forced ventilation method uses local fans to provide a clean amount of air to ensure a favorable environment for workers. With the forced ventilation method, the duct position is usually arranged on the side, and the distance from the duct mouth to the heading face is determined to ensure that l < 6 root s. In this study, a numerical simulation method by Ansys CFX software is applied to study the influence of several factors such as duct position, air temperature of duct, and roughness characteristics of roadway on the temperature of the mine air at the heading face. The models are set up with six duct positions and four air temperature of duct parameters. Model 1 (y =1.1 m) is better than models 2 to 6 in terms of temperature distribution and the lowest temperature values. Four models have different wind temperatures, and we can see the significant influence of the inlet air temperature of the duct on the thermal environment of the heading face. The results show that with the model T = 297.15K, the temperature value on the roadway length is guaranteed as specified < 303K. The result is a reference for determining the duct position and cool for the high-temperature heading face.