采用绝热式自燃测试方法分析煤的自燃倾向

Spontaneous combustion tendency of coal using adiabatic spontaneous combustion test method

对煤的自燃倾向进行快速有效鉴别,有助于对煤的自燃倾向采取分级分类管理从而有效防治煤矿火灾,因而采用绝热式自燃测试方法对煤的自燃倾向进行准确分析很有必要。简要介绍绝热式自燃测试方法的测试原理及其仪器结构,模拟煤炭自燃的物理过程,通过采用包括反应器、气体预热铜管和跟踪温度控制方式等综合绝热措施以实现300 g煤样的自然发火实验,记录煤样从40℃上升到70℃的升温速率(或前30 h的升温速率),测试煤样的自燃特性曲线并分析曲线特征。即建立煤绝热氧化产热速率计算模型,结合实验数据计算所得的煤在绝热氧化条件下的升温速率和产热速率可鉴定煤自燃倾向性的强弱。采用绝热式自燃测试方法对不同煤的自燃倾向分析后表明,无烟煤和部分烟煤的自燃倾向较低,褐煤的自燃倾向较高,故而在煤矿开采时需特别注意褐煤的自燃倾向。

The rapid and effective identification of spontaneous combustion tendency of coal is helpful for classification managing of coals with different spontaneous combustion tendencies,thus,the coal mine fire disaster can be effectively prevented.Therefore,it is necessary to accurately analyze the spontaneous combustion tendency of coal by using adiabatic spontaneous combustion test method.This article briefly introduced the test principle and instrument structure of the adiabatic spontaneous combustion test method,the physical process of coal spontaneous combustion was simulated,by using the comprehensive adiabatic measures including reactor,gas preheating copper tube and temperature-tracking control mode,spontaneous combustion of 300 g coal sample was achieved,the coal sample temperature increasing rates from 40℃to 70℃(heating rates in the first 30 hours)were recorded,the spontaneous combustion characteristic curve of the sample was drawn and analyzed.Calculating model for heat generation rate during the adiabatic oxidation of coal was established,combining with the temperature rising rate and heat generation rate of coal under adiabatic oxidation condition(those rates were calculated from experimental data),the strength of coal spontaneous combustion tendency could be identified.Analysis of the spontaneous combustion tendency of different coals using the adiabatic spontaneous combustion test method shows that bituminous coal and some anthracite have a lower spontaneous combustion tendency and lignite has a higher spontaneous combustion tendency.Therefore,special attention must be paid to the spontaneous combustion tendency of lignite when mining.