地下煤火作为一种全球范围内的灾害，给煤矿生产和生态环境带来了巨大困扰。阴燃作为地下煤火的主要燃烧状态，导致地下煤火持续时间长且极易复燃。因此，研究煤火阴燃蔓延成为治理地下煤火的重要策略。目前，实验及数值模型作为研究手段已开展多项工作，但在反向蔓延数值模型的研究中，仍面临几个亟待解决的关键问题：（1）传统氧气组分运输方程难以解决气固两相之间氧气非均衡的问题。（2）对于阴燃反向蔓延动态过程的氧化反应-氧气输运机制缺乏深入的分析。基于此，本文将实验研究和数值模拟相结合，系统上研究了阴燃蔓延过程中的影响因素及氧化反应-氧气输运机制。

基于煤样物性分析，将其燃烧过程分为四个主要阶段。通过搭建阴燃实验装置，对不同流量以及不同煤样的阴燃特性进行探究，结果表明峰值温度受流量影响显著，其随流量的增大而增大，而超过一定流量的阈值，阴燃峰值温度随流量呈下降趋势。同时，利用遗传算法对动力学参数进行计算，构建包含了水分蒸发及四步反应体系（包含热解以及三步氧化）于一体的气固非均衡数值模型。通过将模拟结果与实验结果进行对比分析，证实了该模型能够较好地模拟阴燃反向蔓延的实验现象，准确性较高。

基于数值模型，对实验中表观温度演变进行分析，结果表明气固非均衡模型的温度前沿均呈凸形演变。对组分质量变化及速率变化进行探讨，发现各步化学反应速率与组分质量随着流量的增大而加快。全局能量分析表明，阴燃反应持续与否取决于全局热量变化。在加热阶段，气体热损失占主导地位，而在蔓延阶段侧边热损失与气体热损失占比最后趋于同一水平。供氧速率分析表明，随着蔓延向下传播，氧气体积分数均呈现先降低后上升规律。对阴燃蔓延前沿进行分析，表明其结构呈凸形蔓延，结构厚度与氧浓度特征长度相关，该结构是决定温度蔓延前沿呈凸形演变的根本原因。基于上述研究对氧化反应-氧气输运机制进行分析，结果表明，除常村煤样(CC煤样)的β-char氧化阶段仅受动力学控制外，其他所有氧化反应均受局部动力学和氧气输运的限制。

As a global disaster, underground coal fire has brought great trouble to coal mine production and ecological environment. As the main combustion state of underground coal fire, smoldering leads to long duration and easy reburning of underground coal fire. Therefore, the study of coal fire smoldering spread has become an important strategy for the management of underground coal fires. At present, many experiments and numerical models have been carried out as research methods, but there are still several key problems to be solved in the study of backward propagation numerical models: (1) The traditional oxygen component transport equation is difficult to solve the problem of oxygen non-equilibrium between gas and solid phases. (2) There is a lack of in-depth analysis of the oxidation reaction-oxygen transport mechanism in the dynamic process of smoldering reverse spread. Based on this, this paper combines experimental research and numerical simulation to systematically study the influencing factors and oxidation reaction-oxygen transport mechanism in the smoldering spread process.

Based on the analysis of the physical properties of coal samples, the combustion process is divided into four main stages. Through the establishment of smoldering experimental device, the smoldering characteristics of different flow rates and different coal samples are explored. The results show that the peak temperature is significantly affected by the flow rate, which increases with the increase of the flow rate, and exceeds the threshold of a certain flow rate, the peak temperature of smoldering decreases with the flow rate. At the same time, the genetic algorithm was used to calculate the kinetic parameters, and a gas-solid non-equilibrium numerical model including water evaporation and four-step reaction system ( including pyrolysis and three-step oxidation ) was constructed. By comparing the simulation results with the experimental results, it is proved that the model can well simulate the experimental phenomenon of smoldering reverse spread, and the accuracy is high.

Based on the numerical model, the apparent temperature evolution in the experiment is analyzed. The results show that the temperature front of the gas-solid non-equilibrium model is convex. The changes of component mass and rate were discussed, and it was found that the chemical reaction rate and component mass of each step increased with the increase of flow rate. The global energy analysis shows that whether the smoldering reaction lasts or not depends on the global heat change. In the heating stage, the gas heat loss is dominant, while in the spreading stage, the proportion of side heat loss and gas heat loss finally tends to the same level. The analysis of oxygen supply rate shows that the oxygen volume fraction decreases first and then increases with the downward propagation. The analysis of the smoldering spread front shows that the structure is convex, and the thickness of the structure is related to the characteristic length of the oxygen concentration. This structure is the root cause of the convex evolution of the temperature spread front. Based on the above research , the oxidation reaction-oxygen transport mechanism is analyzed. The results show that all oxidation reactions are limited by local kinetics and oxygen transport except the β-char oxidation stage of Changcun coal sample ( CC coal sample ), which is only controlled by kinetics.