煤与瓦斯突出冲击致灾机理与强度预测研究

Coal and gas outburst is one of the major safety problems in the production process of coal mining. The high-pressure gas flow and broken coal (rock) that are rapidly ejected in coal and gas outburst can cause casualties, equipment damage. And the formation of a high energy shock wave even leads to reversal of the wind which may cause a secondary disaster. In order to improve the theoretical model of coal and gas outburst and reduce the degree of the outburst disasters, it is necessary to study the disaster-causing mechanism. At present due to the limitations of test methods, it is not yet formed a unified understanding of the disaster-causing mechanism and the disaster evolution law of coal and gas outburst. The project will make the experimental research as the main means, using the self-developed large-scale coal and gas outburst disaster simulation equipment, the physical simulation test of the dynamic effect of coal and gas outburst in different conditions will be carried out. By monitoring the law of gas flow and pressure change during the test process in the simulated roadway, the quality and distribution of the pulverized coal, to reveal the migration law of coal and gas during the process of outburst disaster. Analyze the formation and propagation characteristics of shock waves in the process of outburst, and construct the model of its shock wave propagation. Based on the energy analysis, the quantitative relationship between the pulverized coal quality and the initial energy and the overpressure of the shock wave under the different conditions is taken as the starting point, and the intensity model of outburst considering the shock wave hazard effect is established. It is can provide the basis for the design and arrangement of mine safety disaster prevention system.

煤与瓦斯突出是影响煤矿安全生产的重大安全问题之一。突出时迅速喷出的高压瓦斯流与破碎煤（岩）会造成人员伤亡、设备损毁，形成的具有较高能量的冲击波甚至会导致风流逆转诱发二次灾害。为了完善突出理论模型以及降低突出灾害程度，有必要深入研究突出致灾机理。目前由于测试手段的限制，对煤与瓦斯突出冲击致灾机理及灾变演化规律尚未形成统一认识。本项目以试验研究为主要手段，利用自主研发的大型煤与瓦斯突出致灾模拟试验装置开展不同条件下煤与瓦斯突出致灾动力效应物理模拟试验，监测突出过程中巷道内气体流场与压力变化规律、突出后煤粉质量与分布规律，揭示突出致灾过程煤、瓦斯运移过程；分析突出冲击波形成与传播特征，构建突出冲击波传播模型；基于能量分析，以不同条件下突出煤粉质量与突出冲击波初始能量、冲击波超压等参数的量化关系为切入点，建立考虑冲击致灾效应的突出强度模型，为矿井安全防灾抗灾系统的设计与布置提供基础。

突出时迅速喷出的高压瓦斯流可能形成具有较高能量的冲击波，从而导致风流逆转诱发二次灾害。为完善突出理论模型及降低突出灾害损失，项目以实验研究为主要手段，结合理论分析、数值模拟及事故案例分析验证，研究了突出灾变演化及各主要参数演变规律，分析了突出冲击波形成及传播机理，构建突出强度预测模型并探讨了不同条件下突出强度与突出冲击波超压等参数的量化关系，为矿井安全防灾抗灾系统的设计与布置提供依据。主要获得以下结果：.1）自主设计的煤与瓦斯突出动力效应模拟试验装置及煤与瓦斯突出致灾可视化模拟试验装置具有以下特点：模拟突出孔洞最大达1.88m3，气体压力5MPa；采用双爆破片突出激发方式实现突出口20ms内开启，实现突出的瞬间发动；通过管道系统组件可实现多种流体运移路线、阻力特性、通风设施的巷道网络模拟；多达90路、最高4MS/s的数据采集系统可全方位、高频率的数据采集；同时利用高速摄像机观测到突出过程中煤的运移规律。.2）基于不同气体压力、装煤量、吸附性气体条件的突出致灾动力效应实验，建立了巷道内煤与瓦斯突出灾变演化模型。实验发现突出发生瞬间，管道内瞬间形成冲击波，后面依次出现冲击气流、突出瓦斯气流和煤-瓦斯两相流。且空气冲击波速度>冲击气流速度>突出瓦斯气流速度>突出煤-瓦斯两相流阵面速度。.3）建立煤与瓦斯突出冲击波传播模型，得到突出冲击波超压峰值随传播距离衰减的规律。基于可压缩流动过程本构方程，建立了高压瓦斯运移的动力学模型，借助Fluent数值模拟软件分析了高压瓦斯突出产生冲击波和传播过程，验证了突出冲击波超压预测模型。.4）基于能量平衡原理，构建了煤与瓦斯突出强度预测模型，分析了突出前后能量积聚与耗散规律，得到突出过程中只有20%以内吸附瓦斯参与突出做功，但吸附瓦斯膨胀能是突出的主要能量。探讨不同条件下突出强度与突出冲击波超压的量化关系。基于典型煤与瓦斯突出事故案例验证该事故强度及能量转化过程。