Abstract Hybrid explosion experiments of hydrogen/aluminum dust in open space were performed. Aluminum dust with a median diameter of 56.18 μm was mixed with hydrogen at different volume concentrations (0 %, 5 % and 10 %). Flame propagation was recorded by a high-speed camera. The explosion residues were observed by a scanning electron microscope, and their compositions were analyzed by X-ray photoelectron spectroscopy. The flame propagation velocities and structures, explosion residues and the combustion reaction mechanisms of hydrogen/aluminum dust mixtures were elucidated. The results show that the addition of hydrogen can increase the flame brightness and improve the continuity of the flame front. In the flame propagation process of a hydrogen/aluminum dust hybrid explosion, a micro-diffusion flame and asymmetric flame appeared simultaneously. Compared with pure aluminum dust combustion in air, when 5 % hydrogen-air mixtures were used to disperse the dust, the flame propagation velocities decreased by 0.11-0.15 m/s. Attributable to a variety of intermediate products competing for oxygen and absorbing heat, the hybrid explosion residues cooled faster, porous oxide layers and incompletely oxidized aluminum spheres with small particle sizes were formed. The XPS showed that Al2O3, Al(OH)3, AlO(OH) and other complex products appeared in the combustion reactions. On this basis, a combustion model of hydrogen/aluminum dust hybrid explosion was established.

中文翻译：

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氢/铝粉尘混合爆炸的燃烧行为和残留特性

摘要 开展了空地氢/铝粉尘混合爆炸实验。中值直径为 56.18 μm 的铝粉与不同体积浓度（0%、5% 和 10%）的氢气混合。火焰传播由高速摄像机记录。用扫描电子显微镜观察爆炸残留物，用X射线光电子能谱分析其成分。阐明了氢/铝粉尘混合物的火焰传播速度和结构、爆炸残留物和燃烧反应机制。结果表明，氢气的加入可以提高火焰亮度，改善火焰锋面的连续性。在氢/铝粉尘混合爆炸的火焰传播过程中，同时出现了微扩散火焰和不对称火焰。与纯铝粉尘在空气中燃烧相比，当使用5%的氢-空气混合物来分散粉尘时，火焰传播速度降低了0.11-0.15 m/s。由于各种中间产物争氧吸热，混合爆炸残留物冷却速度较快，形成多孔氧化层和不完全氧化的小粒径铝球。XPS表明燃烧反应中出现了Al2O3、Al(OH)3、AlO(OH)等复杂产物。在此基础上，建立了氢/铝粉尘混合爆炸的燃烧模型。由于各种中间产物争氧吸热，混合爆炸残留物冷却速度较快，形成多孔氧化层和不完全氧化的小粒径铝球。XPS表明燃烧反应中出现了Al2O3、Al(OH)3、AlO(OH)等复杂产物。在此基础上，建立了氢/铝粉尘混合爆炸的燃烧模型。由于各种中间产物争氧吸热，混合爆炸残留物冷却速度较快，形成多孔氧化层和不完全氧化的小粒径铝球。XPS表明燃烧反应中出现了Al2O3、Al(OH)3、AlO(OH)等复杂产物。在此基础上，建立了氢/铝粉尘混合爆炸的燃烧模型。