Study on the effect of different oxygen concentrations on the spontaneous combustion characteristics of coal
不同氧浓度对煤自燃特性影响研究

摘要

为研究不同氧浓度环境对煤自燃特性的影响规律，采用程序升温实验方法，升温速率为5K/min、升温范围30~400℃，气体流速为50ml/min，改变N₂和O₂的气体流速达到0%、3%、5%、7%、10%、12%、15%、18%、21%九种氧浓度条件，然后对新疆准东地区易自燃煤样进行了系统实验研究。通过监测升温过程中CO、CO₂等特征气体产物浓度变化，分析不同氧浓度对煤氧化自燃过程的影响机理。根据实验结果表明，当温度达到100℃，煤样产生的CO₂浓度随着氧浓度升高而显著升高，与此同时CO浓度开始也呈指数型快速增长，且在12%和15%氧浓度的条件下时达到峰值分别为31590ppm、31570ppm。研究结果为矿井防灭火技术的制定和惰化防火措施的优化提供了理论依据。

Abstract

To investigate the influence of different oxygen concentrations on the spontaneous combustion characteristics of coal, a programmed temperature experiment was conducted with a heating rate of 5 K/min, a temperature range of 30~400℃ and a gas flow rate of 50 ml/min. By adjusting the flow rates of N₂ and O₂, nine oxygen concentration conditions were achieved: 0%, 3%, 5%, 7%, 10%, 12%, 15%, 18%, and 21%. A systematic experimental study was carried out using a coal sample prone to spontaneous combustion from the Zhundong region of Xinjiang. By monitoring the changes in the concentrations of characteristic gaseous products such as CO and CO₂ during the heating process, the influence mechanism of different oxygen concentrations on the coal oxidation and spontaneous combustion process was analyzed. The experimental results indicate that when the temperature reached 100°C, the CO₂ concentration generated by the coal sample increased significantly with rising oxygen concentration. Meanwhile, the CO concentration initially exhibited exponential growth, peaking at 31,590 ppm and 31,570 ppm under oxygen concentrations of 12% and 15%, respectively. The research results provide a theoretical basis for the formulation of mine fire prevention and extinguishing technologies and the optimization of inert gas fire prevention measures.