预氧化煤自燃特性试验研究

Experiment Study on Spontaneous Combustion Characteristics of Pre-oxidized Coal

为研究预氧化煤自燃特性参数变化规律,采用程序升温试验研究原煤和预氧化煤的自燃特性。结果表明:与原煤相比,随着温度增加,预氧化至90℃的煤样耗氧速率、CO产生率、CO2产生率、放热强度均大于原煤;随着温度的增加,预氧化至130℃的煤样与原煤的耗氧速率、CO产生率、放热强度曲线的交叉温度为80~90℃,预氧化至170℃的煤样的交叉温度为110~120℃,小于交叉温度时,预氧化煤的耗氧速率、CO产生率、放热强度大于原煤,超过交叉温度后小于原煤;小于80℃时,预氧化至130、170℃的煤样的CO2产生率大于原煤,超过80℃后小于原煤;预氧化煤的最小浮煤厚度、下限氧浓度极值减小,上限漏风强度极值增大;煤的氧化程度越高,自燃极限参数极值变化量越大。

In order to study the variation law of coal spontaneous combustion characteristics,the temperature programming experiment of coal spontaneous combustion was used to research the characteristics of raw coal and pre-oxidized coals.The results showed that,compared with the raw coal,the oxygen consumption rate,CO and CO2 production rate,heat release intensity of pre-oxidized coal to 90℃ were high-er with temperature increased.The variation curves of the oxygen consumption rate,CO production rate,heat release intensity of pre-oxi-dized coal to 130、170 ℃with temperature increased had cross points temperature with that of raw coal. The cross point temperature was 80~90 ℃ to pre-oxidized coal to 130℃ and was 110~120℃ to pre-oxidized coal to 170℃. The above three parameters values of pre-oxidized coals were higher than that of raw coal when temperature was below the cross point temperature while they became smaller in op-posite direction.The CO2 production rate of pre-oxidized coals to 130℃ and 170℃was bigger than that of raw coal when the temperature was below 80 ℃ while it became smaller when the temperature was over 80 ℃. The minimum float coal thickness and lower limit oxygen concentration extremum of pre-oxidized coals decreased,and upper limit air-leakage intensity increased.With higher degree of oxidation, the variable quantity of critical parameters extremum was greater.