固液热阻对无烟煤阴燃蔓延特性影响实验研究

Influence of Solid-Liquid Thermal Resistance on the Propagation Characteristics of Anthracite Smoldering

煤炭阴燃是地下煤火灾治理的难点,治理过程中往往依赖于灌浆等方法,但其治理效果缺乏科学的评判依据.为了高效防治地下煤炭阴燃火灾,结合地下煤矿火灾治理规律,依托自制实验装置对比了原始条件与热阻干扰情况下无烟煤正向阴燃蔓延特性.在连续松散煤体间填充5 cm水、岩粉、金属网、凝胶作为实验热阻,分析填充实验热阻对阴燃峰值温度、阴燃峰值升温速率以及阴燃蔓延速率等煤炭阴燃参数的影响.结果表明:填充水后已燃区温度增加4.7~109.0℃,且能促进煤样阴燃传播,而填充岩粉、金属网、凝胶材料后已燃区温度降低了30.7~422.1℃,且阴燃难以维持传播,总体上热阻对传播的抑制效率排序为:凝胶>金属网>岩粉>水.运用熵值法定义权重及计算的阴燃蔓延危险性综合指数排序为:水>原煤>岩粉>金属网>凝胶.分析和结果可以为快速高效控制阴燃的大面积传播和科学设置火灾缓冲带提供科学依据.

Coal smoldering is a difficult point in underground coal fire control,and the control process often depends on grouting and other methods,but its control effect lacks a scientific basis for evaluation.To prevent and control the smoldering fire of underground coal efficiently,combined with the fire control law of underground coal mines,the forward smoldering propagation characteristics of anthracite under original conditions and those under thermal resistance interference were compared using the self-made experimental device.5 cm of water,rock powder,metal mesh and gel were filled between continuous loose coal bodies as experimental thermal resistance,and the effects of filling experimental thermal resistance on coal smoldering parameters such as peak temperature,peak temperature rising rate and smoldering spreading rate were analyzed.The results show that the temperature of the burned area increases by 4.7—109.0℃with the filling of water and the smoldering propagation of coal sam-ples is promoted,while the temperature of the burned area decreases by 30.7—422.1℃with the filling of rock powder,metal mesh and gel material,and smoldering is difficult to maintain.On the whole,the inhibition efficiency of thermal resistance on propagation is in the order of gel>metal mesh>rock powder>water.The weight is defined by entropy method,and the calculated comprehensive index of smoldering spread risk is in the order of water>raw coal>rock powder>metal mesh>gel.The analysis results can provide a scientific basis for quickly and efficiently controlling the spread of smoldering in large areas and scientifically setting fire buffer zones.