Influence of branch pipes on the deflagration characteristics of methane in confined space

Abstract

To investigate the deflagration characteristics of CH4‐air mixture in confined space, fluid dynamic software Fluidyn was used to build numerical models that each consisted of a horizontal pipe and vertical branches to study the influence of different numbers of branch pipes on the deflagration propagation characteristics of CH4. Research findings suggested that the oscillation trend of the time history curve of pressure at the test point weakened and the peak initial deflagration pressure attenuated in an approximately linear manner with the increase of the propagation distance in the horizontal pipe. With the increase of the number of branches, the peak initial deflagration pressure at the same test point declined with an increasing amplitude. The vertical branch was found to have both “boosting” and “inhibiting” effects on flame propagation. And the inhibiting effect dominated as the number of vertical branches increased, which caused the flame propagation velocity within the horizontal pipe to significantly attenuate. In addition, the functions of the peak initial deflagration pressure varying with the number of branches and propagation distance in the horizontal pipe were obtained by fitting. According to the functions, the vertical branch had marked pressure venting effect on deflagration pressure in the horizontal pipe; the more the branch pipes were, the more significant the pressure venting effect was.

Influence of the opening pressure of explosion‐venting surface on methane deflagration characteristics in municipal sewage confined spaces

“…The deflagration experiment of methane–air mixture was carried out based on an independently designed pipeline, and the numerical model was established by Fluidyn‐MP. Through the comparison between simulation and experiment, the numerical simulation results given in this paper had high confidence, and confirmed that the numerical method was feasible 27 …”

“…The simulation was carried out using the 3D hydrodynamic simulation software Fluidyn‐MP, 27 a multi‐physical field simulation software developed by Fluidyn, a French company. The deflagration experiment of methane–air mixture was carried out based on an independently designed pipeline, and the numerical model was established by Fluidyn‐MP.…”

“…Through the comparison between simulation and experiment, the numerical simulation results given in this paper had high confidence, and confirmed that the numerical method was feasible. 27…”