超细水雾抑制甲烷-煤尘复合爆炸的机理研究

Explosion is one of the main forms of industrial production disaster, which is more severe by the gas-dust mixed explosion, and the loss is also more serious. The research of using ultrafine water mist to suppress gas-dust mixed explosion is still in its infancy. The mechanism and influence factor of explosion suppression have not been quantitatively analyzed, and a perfect theory of explosion suppression has not been also formed. This project aims to the basic research for the influence factor and suppression mechanism of the methane and coal dust mixed explosion using ultrafine water mist. Based on the experiment of methane and coal dust mixed explosion suppression by ultrafine water mist in a closed vessel, the influence regulars of water mist and coal dust characteristic parameters on gas-solid mixed explosion intensity and flame structure will be clarified, and the influence mechanism of the mist characteristic parameters on gas-solid mixed explosion will be also revealed. Meanwhile, a three-dimensional numerical model for the methane and coal dust mixed explosion suppression will be built under ultrafine water mist condition. The physical processes of heat and mass transfer between ultrafine water mist and gas-solid two phases mixed explosion and its suppression mechanism will be quantitatively analyzed. The coupling process of gas-solid two phases combustion and turbulence under ultrafine water mist condition and its influence regular on the flame dynamics characteristic, and the explosion suppression criterion will be also revealed, which provides a scientific criterion for the quantitative expression of the gas-solid mixed explosion disaster prevention.

爆炸是工业生产灾害的主要形式之一，由以气体-粉尘复合爆炸更为剧烈，带来的损失也更加严重。采用超细水雾抑制气体-粉尘复合爆炸的研究尚处于起步阶段，抑爆机理和影响因素尚未量化分析，也未形成完善的抑爆理论。本项目拟对超细水雾抑制甲烷-煤尘复合爆炸的影响因素和抑制机理开展基础研究，基于密闭空间内超细水雾抑制甲烷-煤尘复合爆炸实验，明晰水雾和煤尘特性参数对气固复合爆炸强度和火焰结构的影响规律，揭示水雾特性参数对气固两相复合爆炸的影响机理；建立超细水雾作用下甲烷-煤尘复合爆炸的三维数值模型，量化分析超细水雾与气固两相复合爆炸间的传热、传质等物理过程及其抑制机理，揭示超细水雾作用下气固两相燃烧与湍流的耦合作用过程，以及对火焰动力学特性行为的影响规律，确定抑爆准则，为气固复合爆炸灾害防治定量表述提供科学判据。

通过实验与数值模拟相结合的方法，开展了超细水雾对甲烷-煤尘复合爆炸过程的抑制机理研究。搭建了可视化密闭超细水雾抑制甲烷-煤尘复合爆炸实验装置，并开展了水雾和煤尘特性参数对甲烷-煤尘复合爆炸火焰传播速度、爆炸压力及火焰形貌的影响规律。同时，建立了能够描述水雾的汽化、爆炸流场的湍流流动、气固两相燃烧及两者间耦合作用，以及三相间传热传质等过程的气液固三相数值模型，并验证了数值模型的有效性与准确性。量化分析超细水雾与气固两相复合爆炸间的传热、传质等物理过程及其抑制机理。特别是水雾扩散、蒸发，煤尘挥发份的析出、表面燃烧和运动过程，以及火焰流场、超细水雾和煤尘三者间的耦合过程。这为完善气固两相复合爆炸的抑制机理提供了理论支撑。