Effects of heat transfer mechanism on methane-air mixture explosion in 20 L spherical device

Abstract

This study developed a model of methane one-step combustion mechanism based on the CFD code GASFLOW-MPI to understand the influence mechanism and degree of influence of heat transfer mechanism on methane explosion. Moreover, this study proposed the addition of heat transfer mathematical models using GASFLOW-MPI, including thermal radiation and convection heat transfer. Further, the effects of thermal radiation and convective heat transfer on the shock wave during a methane explosion in a 20 L spherical explosion tank were studied through numerical simulation and the results were compared with the experimental data. The numerical simulation results were found to reasonably predict the peak pressure value and pressure decay process of a methane explosion. In addition, through comparisons of the effects of adiabatic and numerical simulations considering heat loss, the peak pressure of gas explosion calculated via adiabatic simulation were found to be overestimated. Moreover, during the methane-air mixed explosion experiment in the 20 L spherical device, the heat loss was observed to be primarily caused by heat radiation, accounting for more than 76.01% of the total heat loss, followed by convection heat transfer, accounting for 23.99% of the total heat loss. The research results showed that heat loss significantly influenced the methane explosion process. Additionally, for the methane-air mixture explosion experiment in a 20 L spherical device, thermal radiation was the most critical factor that resulted in heat loss in the methane explosion process. Therefore, the influence of thermal radiation and convective heat transfer mechanism on methane explosion must be considered in the numerical simulation of a methane explosion.