再生顶板裂隙漏风诱发煤自燃机制及纳米浆泡材料导向固结机理

再生顶板裂隙漏风引发煤自燃是煤层复采、分层开采过程中的主要灾害之一，亟需探明其自燃演化机制及裂隙固结防控机理。本项目通过构建相似物理模型，基于MIRA超声成像技术，研究再生顶板裂隙动态演化过程，探明裂隙漏风特征。基于煤自燃特性参数测试，融合空隙率、流动、传热、传质等方程，构建再生顶板碎煤自燃演化“流-固-热-化”全耦合模型，实现自燃危险区域的精准判定。研究裂隙温度对纳米浆泡流体扩散效果的影响，揭示温度场对纳米浆泡材料渗流扩散的导向作用机制。研究不同扩散距离处纳米浆泡材料的降温规律，揭示其对高温裂隙场的降温机制。基于固结前后煤岩样界面矿物组成、细微观结构和表面性质等变化表征，揭示纳米浆泡材料固结煤岩的化学浸染作用机制。构建浆泡与煤岩体界之间的界面力学分析模型，揭示固结后煤岩样物理力学特征强化的内在机制。研究成果可为复采、分层开采过程中再生顶板上覆煤体自燃高效防治提供理论支持和科学依据。

The spontaneous combustion of coal caused by air leakage from regenerated roof cracks is one of the main disasters in the process of multiple mining and stratified mining. It is urgent to explore the evolution mechanism of spontaneous combustion and the prevention and control mechanism of fissure consolidation. In this project, the dynamic evolution process of cracks in regenerated roof is studied based on MIRA super-generation imaging technology by constructing similar physical model, and the characteristics of air leakage in cracks are proved. Based on the measurement of coal spontaneous combustion characteristic parameters and the integration of void fraction evolution, flow, heat transfer and mass transfer equations, a fully coupled model of regenerated roof crushed coal spontaneous combustion evolution "fluid-solid-heat-chemical" was constructed to accurately determine the dangerous zone of spontaneous combustion. The effect of crack temperature on the diffusion of nano-particle foam slurry （NFS） fluid was studied, and the guiding mechanism of temperature field on the seepage diffusion of NFS material was revealed. The cooling mechanism of NFS at different diffusion distances was studied to reveal the cooling mechanism of NFS foams to high temperature fracture field. Based on the characterization of mineral composition, micro-structure and surface properties of coal-rock interface before and after consolidation, the mechanism of chemical impregnation of coal-rock consolidated by NFS was revealed. The interface mechanics analysis model between slurry bubble and coal-rock mass boundary is constructed to reveal the internal mechanism of strengthening the physical and mechanical characteristics of coal-rock samples after consolidation. The research results can provide theoretical support and scientific basis for the efficient prevention and control of spontaneous combustion in the regenerated roof and goaf of re-mining and stratified mining face.