Risk exploration of airflow reversal caused by the prominent working face under different ventilation modes

Analyzing and evaluating the safety and reliability of the ventilation system in outburst mining area has important practical significance for optimizing the ventilation system in outburst mine, improving the ability of disaster prevention and resistance in mine.In order to clear and definite the superiority of U-type ventilation and Y-type ventilation in the application of outburst working face, the critical condition of air flow reversal in the inlet duct when gas outburst occurs in the working face under U-type ventilation and Y-type one-in-two-back ventilation is analyzed in this article.Taking the actual ventilation conditions of the working face in Yangquan Baoan coal mine as an example, the requirements of setting and adjusting the position of the air window for the working face advancing under the Y-type “one-in-two-back” ventilation mode are analyzed.And analyzing the relationship between the advancing distance of the working face and the critical gas outburst caused by roadway outburst and airflow reversal under two ventilation modes.The research results show that the critical gas outburst volume of air flow reversal decreases with the decrease of the working face surplus, and the decrease rate is gradually accelerated in the U-type ventilation mode.Under the Y-type, the critical outburst volume of air flow reversal decreases linearly with the decrease of the remaining gas in the working face.At the initial period of working face mining, the ability of Y-type “one-in-two-back” ventilation to resist the airflow reversal caused by gas outburst is much greater than that of U-type ventilation.But with the advance of the working face and the length of the inlet chute becomes shorter, the advantage will become smaller and smaller.