不同φ(CO2)/φ(O2)比例对煤自燃特性的影响

为了研究CO₂对煤自燃特性的影响,利用热重与质谱联用技术测试了阳泉五矿煤在不同φ(CO₂)/φ(O₂)比例下的氧化燃烧过程,分析了热重曲线,特征温度点,放热量与气体逸出规律。研究结果表明:随着φ(CO₂)/φ(O₂)比例增大,热重曲线向高温偏移,特征温度点升高,燃烧剧烈程度降低,气体逸出温度升高;温度小于360℃前,放热量相差较小;温度继续升高后,在相同温度下,放热量随氧浓度降低而降低;由于CO₂与H2反应产生CH₄,所以CO₂含量越高,CH₄逸出强度更高;同时,煤在低氧浓度下更易不完全燃烧,所以会产生更多CO;相较于空气氛围,CO₂浓度高于88%时才具有抑制作用。

Effect of different φ(CO_2)/φ(O_2) ratios on coal spontaneous combustion characteristics

To study the effect of carbon dioxide on coal spontaneous combustion characteristics,the thermogravimetry-mass spectrometry technology was used to test the oxidative combustion process of Yangquan No.5 coal mine under different φ(CO₂)/φ(O₂)ratios.We analyzed thermogravimetric curves,characteristic temperature point,heat release and gas escape laws.The results show that as the ratio of φ(CO₂)/φ(O₂) increases,the thermogravimetric curve shifts to high temperature,the characteristic temperature point increases,the intensity of combustion decreases,and the gas escape temperature increases.Before the temperature is less than 360℃,the difference in exothermic heat is small.As the temperature continues to rise,at the same temperature,the heat release decreases as the oxygen concentration decreases.Since carbon dioxide reacts with hydrogen to produce CH₄,the higher the carbon dioxide content,the higher the CH₄ intensity.At the same time,coal is more prone to incomplete combustion at low oxygen concentrations,so more CO is produced.Compared with air atmosphere,the concentration of carbon dioxide is higher than 88%,which has an inhibitory effect.