ABSTRACT
As a promising green energy source, the risk of hydrogen explosion cannot be ignored. In the industrial environment, the connection between factories and different regions may form a mutated structural space. This structure may have a significant impact on the consequences of hydrogen accidents, which is worthy of study. In this research, the simulation method is used to analyze the explosion and combustion process of hydrogen flame propagation in a sudden expansion pipe, which focuses on the impact of the cross-section ratio. The results indicate that due to the influence of Rayleigh-Taylor instability, the flow field in the dead zone near the sudden expansion structure can be unstable and generate vortices, which will significantly change the development of gas combustion and explosion. Under the extrusion and entrainment of vortices, the flame front structure is changed from finger-like flame to mushroom-like flame. When the flame enters the downstream pipe section through the expansion port, the impact of vortices on the flame propagation velocity is changed from suppression to excitation, and the excitation effect is closely related to the cross-section ratio. At the cross-section ratio μ = 3, the maximum flame propagation velocity and maximum pressure growth rate of the downstream pipe are 198.7 m/s and 53.12 MPa/s, respectively, which are 68.8% and 151.4% times higher than those in the case of the cross-section ratio μ = 1.5. There is a remarkable impact of sudden expansion structure on flame propagation and explosion overpressure.
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Notes on contributors
Yuan Mei
Yuan Mei is a doctor at China University of Petroleum-Beijing. His research interests are accident risk assessment and analysis, as well as research on the mechanism of oil and gas fires.
Jian Shuai
Jian Shuai is a professor at China University of Petroleum-Beijing. His research interests are pipeline integrity management, safety engineering and evaluation.
Yuntao Li
Yuntao Li is an associate professor at China University of Petroleum-Beijing. His research interests are fire risk assessment, safety engineering.
Ning Zhou
Ning Zhou is a doctor at Changzhou University. His research interests is accident risk assessment and analysis, safety engineering and evaluation.
Fei Ren
Fei Ren is a doctor at China University of Petroleum-Beijing. His research interests is pipeline safety.
Wei Ren
Wei Ren is a doctor at China University of Petroleum-Beijing. His research interests is pipeline safety