纳米粉体对工业粉尘爆炸火焰及流场灾变行为的抑制机理

As an important and valid method of explosion suppression,the powder suppression technology was widely applied in industrial explosion prevention and was paid increasing attentions nowadays. Due to the complexity of dust explosion suppression itself, most researches were focused on the macro parameters and qualitative study of explosion suppression effect. Furthermore, the explosion flow and flame structure behviors induced by the dust suppression were not defined and described clearly yet.In this study,the meso and micro-scale experiment system was performed to explore the typically industrial dust explosion flame,accompanied with explosion dynamics and fluid mechanics and thermal disaster diagnosis theory.The nanopowder influence on two-phase flame suppression of dust explosion was investigated. Meanwhile,the interaction effects of nanopowder and flow on flame structure were taken into account. Also,the coupling effects between nanopowder mass surface effect and combustion reaction and heat and mass transfer were explored in detail.Based on the studies of nanopowder influence on dust explosion suppression,the inner mechanism of flame structure and flow behavior change was disclosed clearly,involving in the physical and chemical phenomena. In brief,this research will help to disclose the dust flame structure evolution and flow field characteristic deeply,which further provides reliable test data and support for the dust explosion suppression.

纳米粉体抑爆技术作为有效控制和减弱爆炸灾害的重要手段，在工业爆炸防治领域引起人们越来越广泛的重视。基于粉体抑爆过程的复杂性，目前对其研究以爆炸流场宏观参数与定性的抑爆效果研究为主，尚未能准确描述与界定粉体抑爆诱导的流场变化和火焰结构特征。本研究拟采用中小尺度实验模拟为主，将爆炸反应动力学等理论与热灾害诊断技术相结合，研究纳米粉体对粉尘爆炸两相流火焰及其灾变行为的抑制机理,探索纳米粉体及其诱导的流动与火焰结构的相互干涉作用，以及流场结构与纳米粉体表面效应、传热与传质等现象之间的耦合作用机制等；本研究旨在揭示纳米粉体抑爆过程诱导的物理、化学现象和流场变化特征，并构建抑爆火焰结构模型与流场灾变演化规律，从而为粉尘爆炸灾害防治提供实验依据与理论基础。

纳米粉体抑爆技术作为有效控制和减弱爆炸灾害的重要手段，在工业爆炸防治领域引起人们越来越广泛的重视。本研究采用中小尺度实验平台，将爆炸反应动力学等理论与热灾害诊断技术相结合，通过对典型工业粉尘（铝粉、小麦淀粉、木粉）爆炸火焰的研究，利用动态光学测试、同步热分析等实验手段，结合数值模拟的方法获取了纳米粉体在抑爆过程中的宏观动力学参数；利用细微热电偶、离子探针、压力传感器等火焰精细结构诊断技术，研究了粉尘火焰抑爆过程的气固两相流火焰及流场灾变行为。探究了纳米粉体种类、粉尘粒径、质量分数等因素对工业粉尘云火焰传播温度、速度、离子电流、锋面压力等火焰代表性参数的影响，定量描述了纳米粉体对工业粉尘的抑制效果。本课题所取得的研究成果有助于揭示纳米粉体抑爆过程中的物理、化学现象和流场变化特征，为构建纳米粉体抑爆火焰结构模型及工业粉尘爆炸灾害的防治提供了理论支持和实验依据。