Effectiveness of diluent gases on hydrogen flame propagation in tee pipe (part II) – Influence of tee junction position

• Published in: Fuel (Guildford) Vol. 190; pp. 260 - 267
• Main Authors: Emami, Sina Davazdah, Kasmani, Rafiziana Md, Naserzadeh, Zahra, Che Hassan, Che Rosmani, Hamid, Mahar Diana, Sulaiman, Siti Zubaidah, Ibrahim, Norazana, Samsudin, Mohd Dinie Muhaimin
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 15.02.2017; Elsevier BV
• Subjects: Alternative energy sources; Configurations; Diluents; Explosion severity; Explosions; Flame propagation; Gas explosions; Gases; Hydrogen; Hydrogen enrichment; Hydrogen fuels; Ignition; Obstacles; Overpressure; Pipes; Piping; Tee pipes; Obstacles; Explosion severity; Hydrogen; Tee pipes; Diluents
• ISSN: 0016-2361; 1873-7153
• DOI: 10.1016/j.fuel.2016.11.018

•The flame flow mechanism inside the symmetric and asymmetric tee pipe configurations.•Effects of ignition position on flame acceleration of fuels.•Dynamic of flame acceleration of hydrogen-inhibitors/air mixtures.•Influence of obstacle location on flame development of hydrogen-inhibitors/air mixtures. Gas explosions in obstructed vessels have been investigated for many years. However, the flame acceleration mechanism of enriched-hydrogen fuels with diluents in the piping system has received little systematic study in the literature. This particular study aimed to analyse the flame front mechanism of hydrogen-diluents/air explosion inside the pipe by considering the influence of tee junction distance from the ignition points. The tests were performed using H2/diluents-air at different concentrations and ignition positions, in two different tee junction pipe configurations. From the results, the worst case of explosion severity was found in 95% H2–2.5% Ar–2.5% N2/air for all ignition positions. In general, if ignition happened at the tee junction, the overpressure and rate of pressure rise profiles showed almost a similar trend on both configurations. Similar trend was also observed for the flame flow characteristic analysis. Overall, it was clearly demonstrated that a shorter distance between ignition point and obstacles resulted in higher explosion severity.