有机粉尘点火过程中官能团动态反应及火焰传播突变机理研究

The combustion behavior of organic dust is one of the fundamental problems of dust explosion dynamics. It is significance to study the characteristics of dust ignition and flame propagation in organic dust which will improve the dust combustion theory. Due to the complexity of the chemical structure of organic materials, there are many difficulties in understanding the issues. This project used different types of polyols and coal dust as research objects, and systematically studied the dust combustion dynamics. Firstly, the macroscopic characteristics of dust ignition and the microscopic change law of the dust functional groups were studied to establish the gist of the organic dust ignition based on the dynamic reaction of the functional groups. Secondly, the mechanism of flame propagation in the process of space transformation which effected by the key factors and coupling effects (i.e., dispersion pressure, ignition energy, ignition delay time, etc.) was studied deeply. Lastly, the key parameters that could represent the characteristics of ignition and flame propagation of organic dust are extracted to model that would precisely describe the dynamic reaction of the functional groups during the ignition process and the saltation characteristics of flame propagation during the space transition. The results may deepen and broaden the understanding of the homogeneous and heterogeneous combustion dynamic behaviors of organic dusts. It also may help to understand the complex mechanism of organic dusts combustion and provide theoretical basis for further research on organic dust explosion.

有机粉尘燃烧特性是粉尘爆炸动力学的基础问题，研究有机粉尘点火及火焰传播突变特性对完善粉尘燃烧理论具有重要意义。由于有机物自身化学结构的复杂性，在诸多问题上还存在认识困难。本项目以不同类型的多元醇和煤粉作为研究对象，对其粉尘燃烧动力学特性进行系统研究。首先研究宏观层面粉尘点火特征以及微观层面粉尘官能团动态变化规律，以此建立基于官能团动态反应的有机粉尘点火依据；进一步研究喷粉压力、点火能量、点火延时等关键因素及其耦合作用对空间转变过程中火焰传播突变特性的影响机制；在此基础上，提炼出能够表征有机粉尘点火及火焰传播突变特性的关键参量，从而建立能够准确描述点火过程官能团动态反应及空间转变过程中火焰传播突变特性的模型。研究结果可加深并拓宽对有机粉尘均/异相燃烧动力学特征的认识，有助于理解有机粉尘燃烧的复杂机理，为进一步研究有机粉尘爆炸提供理论依据。

有机粉尘燃烧特性是粉尘爆炸动力学的基础问题，研究有机粉尘点机理火及火焰传播突变特性对完善粉尘燃烧理论具有重要意义。本项目以不同类型的煤粉和有机醇类作为研究对象，对其粉尘燃烧动力学特性进行系统研究。通过宏观粉尘点火实验确定空间转变过程中有机粉尘点火燃烧的关键因素，并结合红外、气体质谱等手段得到了微观层面基于官能团动态变化的粉尘点火规律，在此基础上建立了描述有机粉尘点火过程官能团动态反应及空间转变过程中火焰传播突变特性的模型，并通过分子动力学模拟对燃烧产物及反应路径进行分析。研究结果表明，煤粉点火主要是受到–CH3/–CH2–和–OH的影响，是煤粉中的主要活性官能团，随着粉尘挥发份地减少，活性官能团减少，粉尘更难以点燃，醇类粉尘的火焰传播过程受粉尘的挥发性和自身分解性质的影响。空间转变过程中，有机粉尘的火焰传播分为自由膨胀、加速传播、减速传播三个阶段，火焰速度与温度受燃烧管长影响，所构建模型与实验结果的一致性良好，能够准确描述火焰传播过程中的火焰特性突变情况。研究结果可加深并拓宽对有机粉尘均/异相燃烧动力学特征的认识，有助于理解有机粉尘燃烧的复杂机理，从而为粉尘爆炸灾害的防治提供理论支持。