Effect of low volume fraction of H2 on explosion characteristics and mechanism of AlH3 dust via connected container

• Published in: Powder technology 2025-01, Vol.449, p.120372, Article 120372
• Main Authors: Wang, Hao, Li, Xinfeng, Zhang, Chuanbiao, Xie, Jiani, Zhang, Xin, Yu, Yanwu, Shi, Xueqiang, Jiao, Fengyuan, Xu, Sen, Cao, Weiguo
• Format: Article
• Language: English
• Subjects: AlH3 dust explosion; Explosion mechanism; Low concentration H2; Molecular dynamics simulation; Security strategy
• ISSN: 0032-5910
• DOI: 10.1016/j.powtec.2024.120372

During the storage and use of AlH3, a small amount of H2 is easily decomposed, forming a multiphase composite system that increases explosive hazard. This article discussed the AlH3 dust inducing low concentration H2 explosion and venting characteristics by a connected vessel. The results show that when the concentration of H2 was 1 % and 3 %, which was lower than the lower explosive limit of H2 (4 %), H2 was non-flammable, and the explosion was dust-driven explosion. At H2 volume fraction of 5 %, a dual-fuel-driven explosion dominated, culminating in the maximum explosion pressure, reduced pressure, venting flame length, and velocity. The microscopic reaction mechanism of AlH3 with H2 was explored using molecular dynamics simulations. Meanwhile, for the security strategy of AlH3 dust explosion venting with low H2 atmosphere, the NFPA 68 and EN 14491 standards predicted the venting flame length effectively, offering critical insights for the application and safety design of AlH3. [Display omitted] •Pmax and Pred of different volume fractions of H2 induced AlH3 explosion were contrasted.•Venting flame propagation characteristic of AlH3 induced low concentration H2 were analyzed.•Combustion reaction mechanism of AlH3 induced low concentration H2 were established.•Applicability of the NFPA 68 standard and EN 14491 standard was discussed.