煤粉广泛应用于火电、化工及冶金领域，在制备及输送过程中，由于氧化活性增强极易自然发火并诱发燃爆事故，严重威胁作业人员生命安全。为预防煤粉灾害事故发生，研究最低着火温度对应着火延迟时间等关键临界参数的影响因素及预测具有重要义。通过搭建煤粉自然发火演化试验系统，采集硫磺沟矿和红柳矿的2种变质程度煤粉，并放置于反应池进行恒温氧化试验，分析了煤粉自然发火临界参数影响因素；同时建立了煤粉自然发火临界参数数学预测模型，对煤粉自然发火临界参数进行预测。结果表明：氧浓度和堆积厚度是影响煤粉自然发火临界参数的重要因素。煤粉的最低着火温度和对应着火延迟时间随氧浓度的降低显著增加，氧浓度降低抑制煤粉活性结构与氧气反应，减缓煤粉的升温速率，进而增加煤粉的最低着火温度和着火延迟时间。随着煤粉堆积厚度的增加，煤粉氧化释放的热量更容易蓄积，煤粉的最低着火温度逐渐降低，最大降幅可达34 ℃。而煤粉堆积厚度的增加可减缓氧气进入煤粉内部的扩散率，对应着火延迟时间表现出增加趋势。利用线性回归方法建立了数学预测模型，可用于计算煤粉自然发火临界参数，为煤粉自然发火引发爆燃事故防控提供了依据。

Pulverized coal (PC) is widely used in thermal power,chemical and metallurgical fields. In the process of preparation and transportation,due to its increased oxidation activity,it is easy to spontaneously ignite and induce explosion accidents,which seriously threatens the life safety of operators. In order to prevent the occurrence of PC disasters,it is of great significance to study the influencing factors and prediction of the critical parameters of PC spontaneous combustion. The key critical parameters such as the minimum ignition temperature (tM) and the corresponding ignition delay time (ti) for the self-ignition of PC were studied. Through the establishment of the self-ignition evolution experimental system of PC,the pulverized coal with two levels of metamorphism from the Liuhuanggou mine and the Hongliu mine were collected and placed in an equidistant cylindrical reaction tank for a constant temperature oxidation experiment. The influencing factors of the critical parameters of PC spontaneous combustion were analyzed. The mathematical prediction model for the critical parameters of PC spontaneous combustion was established to predict the critical parameters. The results show that oxygen concentration and accumulation thickness are important factors affecting the critical parameters of PC spontaneous combustion. With the decrease in oxygen concentration,MIT and ti of the two types of coal powder increase remarkably. The decrease of oxygen concentration inhibits the reaction of the active structure of PC with oxygen,slows down the heating rate of PC,and then increases the MIT and ti of pulverized coal. As the thickness of pulverized coal increases,the heat released by pulverized coal oxidation is more likely to accumulate. The minimum ignition temperature of pulverized coal gradually decreases,and the maximum drop can reach 34 ℃. The increase in the thickness of the PC accumulation can slow down the diffusion rate of oxygen into the PC,which shows an increasing trend corresponding to ti. A linear regression mathematical prediction model is established using linear regression method,which can be used to calculate the critical parameters of pulverized coal spontaneous combustion and provide a basis for the prevention and control of deflagration accidents caused by PC spontaneous combustion.