煤层露头自燃火灾演化规律数值模拟研究

摘要

In order to solve the resource waste and environmental pollution caused by spontaneous combustion in coal seam outcrop, taking Taileweiqiuke in Xinjiang as the research object, the evolution laws of spontaneous combustion in coal seam outcrop under the effect of fire pressure and the combined effect of fire pressure and external wind pressure were studied by numerical simulation method, so as to provide a basis for the effective management of fire area and the protection of environment.The results showed that under the effect of fire pressure, the maximal wind speed was 0.729 m/s, and the maximum fire pressure was 170.2 Pa.Under the combined effect of fire pressure and external wind pressure, the dynamical system of coal seam outcrop was a negative pressure ventilation system.When the air leakage velocity was 0.2 m/s, the variation laws of temperature, oxygen concentration, velocity and pressure at five typical positions were analyzed, and the influence of porosity and air leakage velocity on spontaneous combustion fire in coal seam outcrop was analyzed.It indicated that the large pores and air leakage and oxygen supply provide favorable conditions for the large-scale development of fire.The results lay a solid foundation for the management of fire area and the protection of ecological environment.%为解决煤层露头自燃所引起的资源浪费和环境污染,以新疆台勒维丘克煤层露头为研究对象,采用数值模拟方法研究煤层露头在火风压、火风压及外部风压作用下的自燃演化规律,为治理火区和保护环境提供依据.研究表明:火风压作用下,风流最大流动速度0.729 m/s,火风压最大达到170.2 Pa;火风压与外部风压联合作用下,煤层露头动力系统是负压通风系统,在漏风速度为0.2 m/s时,研究5个典型位置的温度、氧浓度、速度及压力的变化规律;并分析孔隙率、漏风速度对煤层露头自燃火灾的影响,说明大孔隙和漏风供氧为火灾大规模发展提供有利条件.研究成果对治理火区及保护生态环境奠定坚实基础.