1.School of Emergency Management and Safety Engineering, China University of Mining and Technology(Beijing), Beijing ,China; 2.State Key Lab of Coal Resources and Safe Mining,Beijing , China; 3.State Key Lab Cultivation Base for Gas Geology and Gas Control-Province of State Key Lab Breeding Base,Jiaozuo , China; 4. Shanxi Water Conservancy and Construction Engineering Bureau，Taiyuan ,China

This paper aims to properly control the inlet air velocity of roadway and reduce the occurrence of fire and its damage in coal mines. Fluent is used to conduct the numerical simulation of airflow in a coal mine roadway in the presence of fire. The effects of different inlet speeds on the velocity field, temperature field and distribution of gas emission are discussed. The results show that the greater inlet air velocity is associated with smaller influence on air flow distribution in the roadway and the lowest air velocity is located in the flame zone.The longitudinal distribution profile of the velocity forms an “arc layered” shape.As fire increases the gas concentration in the roadway, when air velocity is low, the gas concentration can reach the lower limit of gas explosion,causing gas explosion. Changes of air velocity would cause large change in the distance of “smoke flow back”. The greater the air velocity is, the more significant the smoke exhaust effect in the roadway is. The simulation results show that properly control of the inlet air velocity of roadways has a significant effect on preventing gas explosion and smoke emission in the roadway after fire and explosion.

国家重点研发计划资助项目(2018YFC0808301)；北京市自然科学基金面上资助项目(8192036)；河南省瓦斯地质与瓦斯治理重点实验室——省部共建国家重点实验室培育基地开放基金资助项目(WS2018B04)