非均匀分布作用下典型金属复合粉尘云爆炸动力学影响机制研究

金属和合金粉尘具有高爆炸敏感性和危险性，目前研究集中于形貌和制备方式单一的粉尘，对于不同颗粒形貌和制备方式的金属复合粉尘爆炸机理缺乏系统全面的研究，尚未准确揭示非均匀分布作用下两相复合体系爆炸灾害的理论链。本研究以不同颗粒形貌和制备方式的典型金属复合粉尘为研究对象，建立金属复合粉尘瞬态浓度和流场分布观测系统，利用实验结果对模拟建立的瞬态弥散模型进行修正，实现对反应区全域粉尘瞬态弥散度、湍流分布及金属复合粉尘着火条件的可靠预测。采用动态光学测试、多相流场监测与爆炸产物检测分析相结合的方法，研究金属复合粉尘弥散度和湍流耦合下的爆炸能量传递规律；建立粉体物性表征与爆炸动力学参数之间的相关性，解析爆炸微观动力学反应机制。结合实验研究和数值方法揭示非均匀分布作用下金属复合粉尘爆炸火焰结构与演化机理，揭示爆炸宏观动力学与火焰微观结构的耦合作用。本研究为预防粉尘爆炸事故、完善粉尘爆炸机理提供科学依据。

Metal and alloy dust have high ignition sensitivity and explosion hazards. At present, most research has focused on dust with a single morphology and preparation method, and hence there is a distinct lack of systematic and comprehensive research on the explosion mechanism of composite metal dust with different particle morphology and preparation methods. The theoretical chain of explosion disaster under the action of nonuniform distribution in the two-phase system has not been accurately revealed. This study takes the typical composite metal dust with different particle morphology and preparation methods as the research object, intends to establish an observation system for the flow field and the transient concentration of composite metal dust, and apply the experimental data to modify the simulation model of transient dust dispersion. One goal of this research is to achieve reliable prediction of transient dispersion and turbulence distribution in the entire reaction area, and establish a prediction model for the ignition criterion of the two-phase system. The law of explosion energy transfer under the coupling effect of dust dispersion and initial turbulence is explored by using dynamic optical testing method, multiphase flow field monitoring as well as explosive product detection and analysis methods. The correlation between powder physical properties and explosion dynamics is established, and the reaction kinetics of composite metal dust cloud is studied. Combining experimental investigations and numerical simulations, the flame structure and evolution mechanism of composite metal dust explosion under the action of nonuniform distribution of transient dust dispersion and turbulence intensity is investigated, and the coupling effect of explosion macrodynamics and flame microstructure is revealed. This research provides scientific basis for preventing dust explosion accident and perfecting dust explosion mechanism.