Influence of the shape and number of obstacles on the excitation effect of dust-containing gas explosion

• Published in: Powder technology 2024-12, Vol.448, p.120253, Article 120253
• Main Authors: Zhou, Zhenxing, Wang, Gongda, Xu, Jingde, Wang, Haiyan, Zhang, Licong, Liu, Yikang
• Format: Article
• Language: English
• Subjects: coal; Coal dust; combustion; disaster preparedness; dust; equipment design; Gas explosion; Numerical simulation; Obstacle; technology
• ISSN: 0032-5910
• DOI: 10.1016/j.powtec.2024.120253

To investigate the excitation effects of different shapes and quantities of obstacles in dust-containing gas explosions, this study utilized an Euler-Lagrangian model. This model simulated explosions involving dust-laden gas, applying various governing equations to address the roles of coal dust at different combustion stages and its dynamic forces within the flow field. The research examined a 9.5 % gas concentration explosion with 5 g/m3 coal dust in a straight pipeline, assessing the impacts of spherical, regular tetrahedral, and cuboidal obstacles, as well as combinations of 1–3 cuboidal obstacles and three differently shaped obstacles on the explosion's flow field structure, overpressure, and flame propagation speed. Key findings include: dust-containing gas explosions result in more complex flow field structures, and the excitation effects of coal dust and obstacles on flame propagation speed exhibit mutual inhibition. Obstacles increase the maximum overpressure locally without affecting the overall trend of increasing overpressure with distance in closed conduits. Cuboidal obstacles show the most pronounced excitation effects, followed by regular tetrahedral and spherical obstacles, respectively. The number of obstacles also progressively enhances their excitation effects. When three obstacles of different shapes are present, cuboidal and regular tetrahedral obstacles primarily affect the flow field structure, with flame propagation speed and maximum explosion overpressure slightly lower compared to the presence of three cuboidal obstacles alone. These findings offer valuable insights into the destructive effects of gas explosions and the excitation effects of obstacles, providing theoretical support for disaster prevention and recommendations for underground equipment design and layout. [Display omitted] •A numerical method for biphasic explosions is proposed to investigate variations in flow field structure.•The study examines dust-gas explosion propagation under the influence of obstacles with varying shapes and quantities.•This study analyzes flow field structure to investigate how coal dust and obstructions stimulate gas explosions.•The study comprehensively considers the combustion characteristics of coal dust during its participation in gas explosions.