风速对煤堆自燃影响的数值模拟

Numerical Simulation of Effect of Wind Speed on Coal Pile Spontaneous Combustion

为研究煤堆自燃特征及风速对其的影响,建立温度场、速度场、氧浓度场等多场耦合的煤堆自燃模型,运用COMSOL软件对不同风速下的煤堆自燃过程和指标参数进行数值模拟分析。模拟结果表明：随着风速的增大,煤堆两侧的风压增强,对空气深入提供直接动力;煤堆最易自燃的风速在0.005-1 m/s范围,当风速为0.5 m/s时达到临界温度的最短时间为36 d,随着风速的增大,煤堆达到临界温度的时间延长。据此,建立低风速下的煤堆临界温度与风速的关系公式,可以有效地确定煤堆内部的温度,对防止自燃有积极的作用。

In order to study the characteristics and the influence of wind speed on coal pile spontaneous combustion,the multifield coupling of spontaneous combustion model of the coal pile,including temperature field,velocity field and oxygen concentration field,was established. The process and parameters of the coal pile spontaneous combustion under different wind speed were analyzed by COMSOL software. The simulation results showed that the air pressure on both sides of the coal pile was enhanced with the increase of wind speed,which was the direct driving force. Coal pile in wind speed within the scope of 0. 005 to 1 m / s was most easily spontaneous combustion,when the wind speed in 0. 5 m / s reached the critical temperature is 36 d. With the increase of wind speed,the time reaching critical temperature was prolonged. The relationship formula of the critical temperature and the wind speed of the coal at low wind speed was established,which could get the internal temperature of coal effectively,and has a positive effect to prevent spontaneous combustion.