采动条件下火区有害气体运移特征分析

Analysis on migration features of harmful gas in coal fire zone under mining condition

针对采区上部小煤矿火区气体会直接威胁采面安全开采的问题,分析了乌海某矿火区漏风源、汇的特点,利用示踪气体分析技术,确定了小煤矿火区对主要采面的影响范围及与工作面的联通关系,进而构建了火区的物理模型及边界条件,模拟了工作面未达到火区、工作面位于火区下方、工作面越过火区3种状态下的火区CO向1604工作面的影响时间和运移规律。结果表明,工作面位于火区下方时,采空区CO较未达火区时的浓度升高提前约30 min,且工作面回风流中CO的升高量高于回风隅角;工作面越过火区后,工作面及邻近区域CO浓度上升速度加快。模拟结果与火区实际监测规律类似,可为制定采区回采计划和安全措施提供依据。

According to the gas from the fire zone in the top small coal mine of the coal mining block directly threatened to the safety mining of the coal mining face,the air leakage source and converged features of the coal fire area in a Wuhai mine were analyzed. The analysis technology of the tracer gases was applied to determine the influence scope of the fire zone in small mine to the major coal mining faces and the connection relationship of the coal mining face. Then a physical model and boundary condition of the fire zone was established. The influence time and migration law of CO in the fire zone to No. 1604 coal mining block were simulated under the three statuses as the coal mining face not in the fire zone,the coal mining face under the fire zone and the coal mining face passed the fire zone. The results showed that when the coal mining face was under the fire zone was not reached in the fire zone,CO concentration in the goaf would rise 30 minutes in advance than the coal mining face not in the fire zone,and in the air return flow of the coal mining face,CO risen value was higher than the air return corner.When the coal mining face passed the fire zone,CO concentration rose faster in the coal mining face and adjacent area. The simulation results were similar to the actual monitoring law of the fire zone. The study achievements could provide the theoretical basis to set up the mining planning and safety measures of the mining face.