摘要
采空区注氮是预防遗煤自燃的重要手段,明确不同注氮条件下采空区自燃危险区域变化以及注氮量极值,可为采空区注氮防灭火提供重要的参数指导。本文基于工作面漏风实测与数值模拟方法,构建了综放工作面采空区注氮数值模型,分析未注氮以及200~1600 m^(3)/h注氮量条件下采空区氧浓度、温度等参数变化,给出采空区自燃危险区域变化规律以及最大合理注氮量。结果表明:未注氮采空区存在40℃高温区域,进风侧氧化升温带21~130 m.当注氮200 m^(3)/h时,采空区40℃等值面消失,随着注氮量增加,采空区33℃以上高温区域不断减小,直至注氮1600 m^(3)/h时基本消失,氧化升温带最大宽度则由109 m逐步降低至11 m,注氮效果显著。以工作面回风侧氧气浓度不低于18%为基准,确定采空区最大注氮量为1220 m^(3)/h.
Nitrogen injection in goaf is an important means to prevent spontaneous combustion of coal.Clarifying the change of spontaneous combustion hazard zone and the injection extreme value during nitrogen injection in goaf can provide important parameter guidance for preventing and extinguishing coal fire.In this paper,a numerical model of nitrogen injection in goaf was constructed based on the method of air leakage measurement and numerical simulation.By analyzing the change of parameters such as oxygen concentration and temperature in goaf under the conditions of no nitrogen injection and 200~1600 m^(3)/h nitrogen injection,the change rule of spontaneous combustion hazard zone and the maximum reasonable nitrogen injection in goaf are obtained.The results show that:there is a 40℃high tem-perature zone in goaf without nitrogen injection,and the oxidation heating zone on the aie inlet side is from 21 to 130 m.When 200 m^(3)/h nitrogen is injected,the 40℃isosurface is disappeared in goaf.As the amount of nitrogen injection increases,the high temperature zone above 33℃in goaf continues to decrease.Until the nitrogen injection reaches 1600 m^(3)/h,the high temperature zone is basically disappeared,and the maximum width of the oxidation heating zone is gradually reduced from 109 m to 11 m.The nitrogen injection effect is significantly to prevent coal fire in goaf.On the basis of oxygen concentration in the return air side of working face is not less than 18%,the maximum nitrogen injection in goaf is determined to be 1220 m^(3)/h.
出处
《山西焦煤科技》
CAS
2021年第9期4-8,56,共6页
Shanxi Coking Coal Science & Technology
关键词
煤自燃
采空区注氮
注氮量
自燃“三带”
Coal spontaneous combustion
Nitrogen injection in goaf
Numerical simulation
Spontaneous com-bustion“three zones”
Nitrogen injection volume
作者简介
张勋(1989-),男,山东济宁人,2015年毕业于辽宁工程技术大学,副教授,主要从事矿井火灾防治理论与技术研究工作,E-mail:zhangshen1989@163.com。
