采空区亚自燃状态及其向自燃转化研究

针对高危自燃采空区遗留煤发生自燃问题,提出采空区亚自燃状态的概念.开采推进过程中的采空区自燃,都可理解为是从亚自燃状态向自燃状态转化的结果,且其转化过程时间很短,小于最短自然发火期.在不同条件下的自燃过程满足叠加组合原理,采空区亚自燃状态向自燃转化过程是两种以上过程的叠加.转化受亚自燃状态程度(稳定温度)、工作面推进度、漏风供氧、煤堆积状态及防灭火措施(注氮)等因素影响.亚自燃状态理论能够解释生产实践中一旦某一不利因素出现,能在短时间内导致自燃发生的现象(自燃突发性).亚自燃状态概念的提出,将有助于从理论上正确认识实际采空区自燃状态的演变过程,实现早期预防采空区自燃的发生.

Inferior spontaneous combustion state and transformation towards spontaneous combustion in goaf

The concept of inferior spontaneous combustion state in goaf is presented regarding the coal goaf with high risk of spontaneous combustion.The goaf spontaneous combustion during mining can be understood to result from the transformation of inferior spontaneous combustion state to spontaneous combustion state,with short transforming time which is less than the shortest spontaneous combustion time.Spontaneous combustion process under different conditions satisfies superposition combination principle,and the transformation process is due to the superposition of over two kinds of processes.Transformation may be affected by factors such as the degree of inferior spontaneous combustion state(immobile temperature),working face impelling speed,air leakage and oxygen supply,stack state and fire security measures(nitrogen injection),etc.The theory of inferior spontaneous combustion state can explain that once some unfavorable factor appears,spontaneous combustion can be induced in short time(burst spontaneous combustion).The concept of inferior spontaneous combustion state will help understand the evolution of spontaneous combustion in practical goaf,and realize the early prevention of the spontaneous combustion in goaf.