采空区自燃“三带”微循环理论及漏风流场数值模拟

The "Three Zones" Microcirculation Theory of Goaf Spontaneous Combustion and a Numerical Simulation of the Air Leakage Flow Field

为掌握采空区自燃“三带”分布及其自然发火规律，通过唐口煤矿2307工作面采空区自燃“三带”现场温度和气样观测，利用FLUENT软件对采空区漏风流场数值模拟．结果表明：采空区自燃是一个氧热微循环过程，当漏风供氧大于氧化耗氧、氧化生热大于漏风散热时，氧热微循环可持续进行，直至自燃；得出工作面不同风量下采空区自燃“三带”的区域．进风巷侧采空区可能自燃带范围在48．2～98．6m，而回风巷侧采空区可能自燃带范围在24．3～98．6m．经对比分析，得出最有利于采空区防灭火的最佳供风量为1200～1440m3／min，可满足防灭火的需要．

The 2307 working face of the Tangkou mine was studied by taking temperatures and gas samples at the goaf and considering the ＂Three Zones＂ spontaneous combustion model. FLUENT was used to simulate the air leakage flow field at the goaf. The results show that spontaneous combustion appears to involve both micro-circulation of oxygen and thermal processes. Spontaneous combustion will occur when oxygen input from ventilation leakage is greater than oxygen consumption by the oxidative process and the ventilation leaks dissipate less heat that produced by coal oxidation. The zone of spontaneous combustion of ＂Three Zones＂ with different air volume is obtained. On the intake side of the goaf spontaneous com- bustion was possible over the range from 48.2 m to 98.6 m. At the return side the range was 24.3 m to 98.6 m. The best air supply volume for goaf fire prevention and extinguishment was found to be between 1 200 m3/min and 1 440 m3/min.