综采工作面进风巷火灾数值模拟研究

Numerical Simulation of Fire in Intake Airway in Fully Mechanized Working Face

为研究综采工作面进风巷发生火灾时的烟气受火源规模和风速影响的变化规律,运用FDS火灾模拟软件,分别设置1、2、5、10、20 MW 5种火源规模,以及1.0~2.4 m/s内8种风速进行火灾模拟,并对不同火源规模和不同风速条件下综采工作面进风巷火灾发生时期的CO浓度、温度和能见度进行了数值模拟对比研究。结果表明:①随火源规模增大,CO浓度增大,CO浓度分布进入稳定阶段所需时间延长,温度上升到达稳定阶段所需时间延长,温度下降速度加快;②随风速增大,CO浓度分布进入稳定阶段所需时间缩短,稳定阶段CO浓度减小,回风巷温度升高;③随风速增大,烟气传播速度加快,出口处能见度可见范围缩小;④随风速增大,火源上风侧CO浓度及温度均降低,烟流逆退距离缩短,超过临界风速后烟气不产生逆退现象。研究结果可为井下工作人员在火灾发生时期安全逃生提供指导。

In order to study the change rule of smoke under the influence of fire source scale and airflow velocity when fire occurs in intake airway in fully mechanized working face.Using PDS fire simulation software to simulate the variation of the CO concentration,temperature and visibility under the different fire source scales and airflow velocity.The five fire sources scales were 1 MW,2 MW,5 MW,10 MW and 20 MW respectively.The eight kinds of airflow velocity were in the range from 1.0 m/s to 2.4 m/s.The results show that:(1)as the size of fire source increases,CO concentration increases,the time required for CO concentration distribution to enter the stable stage is prolonged,the time required for temperature rise to reach the stable stage is prolonged,and the speed of temperature drop is accelerated;(2)with the increase of airflow velocity,the time required for CO concentration distribution to enter the stable stage is shortened,the CO concentration decreases in the stable stage,and the temperature in return airway rises;(3)with the increase of airflow velocity,smoke spread faster,and visibility narrows at the exit;(4)as the airflow velocity increases,CO concentration and temperature in the upper windward side of the fire source decrease,and the distance of smoke rollback shortens,the smoke does not rollback after exceeding the critical airflow velocity.The study can provide guidance for underground workers to escape safely during a fire.