Numerical Simulation of Smoke Variation During Fire in Intake Airways on a Coal Mining Face

Abstract

In order to study the variation of smoke parameters during fire in the intake airway of coal mining face under the different fire source scales and wind speeds, the variation of the CO concentration, temperature and visibility were simulated by Pyrosim. The five fire sources scales are 1, 2, 5, 10 and 20 MW, respectively. The eight kinds of airflow velocity are in the range of 1.0–2.4 m/s. The results show that: (1) With the increasing size of the fire source, the concentration of CO and the time required for CO and temperature entering the stable phase are increased, and the speed of temperature drop is accelerated. (2) As the air velocity increases, the time required for CO entering the stable phase is shortened, and CO concentration in steady phase decreases. As the air velocity goes up, the temperature in return airways rises. With the air velocity decreases, the temperature at the fire source falls. (3) As the air velocity rises, the smoke spreads faster and the visible range at the exit narrows. (4) As the air velocity increases, CO concentration and temperature in the upper windward side of the fire source decrease, and the rollback distance of the smoke flow shortens. The smoke does not rollback after exceeding the critical wind speed.