为给采空区煤自然发火的实际探测及数值分析提供理论支持,研究氧体积分数(φi)、粒度(D)和温度(T)复合作用条件下的松散煤低温氧化的耗氧速率(v0)模型。设计松散煤在氧体积分数相同、粒度不同和粒度相同、氧体积分数不同2种方式下煤的程序升温实验,应用气相色谱仪分析特定温度下的出口气体氧体积分数并对松散煤的耗氧速率进行计算,比较不同氧体积分数、粒度条件下煤样在不同温度点的耗氧速率,得出单一变量条件下的v0-φi,v0-D和v0-T曲线。研究结果表明:耗氧速率与煤样温度基本呈指数关系,与氧体积分数呈对数关系,与松散煤样粒径呈负指数关系;在低温条件下,温度、粒径和氧体积分数3个因素对松散煤耗氧速率的作用相对独立。最后,在实验分析的基础上建立以耗氧速率为因变量,温度、氧体积分数、粒度为自变量的松散煤低温耗氧速率复合作用模型。
To provide theoretical support for actual detection and numerical analysis of goaf coal self-ignition, the oxygen consumption rate(v0) model of loose coal under the combined effect of oxygen volume fraction φi, coal diameter(D) and temperature(T). The temperature-programmed experiments were designed for loose coal under two different conditions, identical φi with different D and different φi with identical D, the gas chromatograph was used to analyze the oxygen volume fraction of outlet gas at certain temperatures and the oxygen consumption rates were calculated, the rates of different experimental conditions were compared, and the v0-φi, v0-D and v0-T curves were drawn under the conditions of single variable. The results show that there is exponential relationship between v0 and T, logarithmic relationship between v0 and φi, and negative exponential relationship between v0 and D; the effects of T, φi and D to v0 are relatively independent. Based on the analysis, an combined effect model of loose coal low-temperature oxygen consumption rate, with v0 as independent variable and T, φi and D as dependent variables, is established.