从粉尘卷扬到二次爆炸:可燃气体−沉积粉尘复合体系的多相流动力学与爆炸机制研究进展及展望

Comprehensive review of multiphase flow dynamics and explosion mechanisms in hybrid combustible gas–deposited dust systems: From dust entrainment to secondary explosions

  • 摘要: 可燃气体–沉积粉尘复合体系的爆炸灾害长期以来对涉粉企业构成严重安全威胁,尤其是在初次爆炸引发粉尘卷扬后,极易产生连锁反应诱发二次爆炸。而二次爆炸由于其传播距离远,破坏范围广,且具有高度不确定性,常导致远超初次爆炸的灾难性后果。为此,基于文献调研,全面综述了该类复合体系中从粉尘卷扬到激波诱导下二次爆炸过程中的关键多相流动力学与爆炸机制特征。通过扬尘机理、运动模型以及粒子运移规律3个方面重点梳理并阐释了粉尘卷扬过程中的分子扩散动力学机制,并总结基于机器学习算法的粉尘浓度动态预测及爆炸参数的快速量化建模,梳理各文献中算法的使用频率及特点。同时,结合实验研究和数值模拟手段,梳理了二次爆炸过程中的爆炸压力特性、火焰传播特性、气固两相流场演化规律和爆炸反应微观机理方面的研究进展。研究结果表明激波诱导的粉尘卷扬过程是流体–颗粒–冲击波多物理场耦合作用的结果,其复合体系的爆炸特性不仅取决于粉尘本身的固有属性,还受到外部激波作用下复杂的流场环境的影响。此外,归纳了可燃气体–沉积粉尘复合体系的气固耦合流场演化特性,发现其流场结构直接影响粉尘云状态和燃烧效率,从而主导二次爆炸的发生。最后,基于微观表征与反应路径分析,以低热稳定性的煤尘和高热稳定性铝尘为例,探讨其爆炸机理。最后基于现有研究成果,对未来二次爆炸亟待解决的问题进行展望,旨在完善复合体系爆炸的理论框架,为工业爆炸灾害的精准防控与本质安全提升提供依据。

     

    Abstract: The explosion hazards associated with hybrid combustible gas–deposited dust systems have long been posing severe safety threats to powder-processing industries. Particularly, initial explosions triggering dust entrainment readily initiate chain reactions that induce secondary explosions. Given that secondary explosions exhibit long-range propagation, extensive destruction scales, and high unpredictability, they frequently cause catastrophic consequences far exceeding primary explosions. Based on comprehensive literature review, key multiphase flow dynamics and explosion mechanisms throughout the dust entrainment to shockwave-induced secondary explosion process are systematically synthesized. It systematically examines molecular diffusion kinetics in dust entrainment through three aspects: entrainment mechanisms, motion models, and particle transport principles. Additionally,summarize the dynamic prediction of dust concentration based on machine learning algorithms and the rapid quantification modeling of explosion parameters, while reviewing the frequency and characteristics of algorithm usage across various literature. Furthermore, by integrating experimental studies and numerical simulations, it reviews research advances in explosion pressure characteristics, flame propagation behaviors, gas-solid two-phase flow field evolution patterns, and microscopic explosion mechanisms. Results demonstrate that shock-induced dust entrainment stems from strongly coupled multiphysics interactions among fluid dynamics, particle mechanics, and shock waves. The explosion behavior of hybrid systems depends not only on inherent dust properties but also on complex flow-field environments governed by external shocks. Additionally, analysis of gas–solid coupled flow evolution reveals that flow-field structures directly determine dust cloud distribution and combustion efficiency, thereby dominating secondary explosion initiation. Finally, through microcharacterization and reaction pathway analysis, explosion mechanisms are contrasted using low-thermal-stability coal dust (pyrolysis-dominated) and high-thermal-stability aluminum dust (surface-oxidation-dominated). Concluding with current research findings, future critical challenges are outlined to refine theoretical frameworks for hybrid explosions, providing foundations for precise prevention/control of industrial explosion disasters and inherent safety enhancement.

     

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