The Study Of Premixed Flame Propagating And Quenching In Narrow Channel

The investigations into premixed flame propagating in flame arrester elements are quite important for design and application of flame arresters since flame arresters are widely used in combustible gas transport pipe network in industry to avoid disaster explosion. Aiming to provide theoretical references for deflagration suppression and the design of flame arresters, premixed flame propagating and quenching in narrow under different conditions are studied in this paper in experiment and numerical simulations.Propane/air premixed flame propagating and quenching in narrow channel are studied in experiment, and the relationships between the quenching distance with the flame velocity and channel gap are obtained. Meanwhile, these results can give more reference to the work of numerical simulations.Two-dimensional theoretical model for unsteady premixed flame propagating in parallel plane is built. After grid size sensitivity simulations are performed in Fluent, a general propose CFD code, propane/air and methane/air premixed flame with different velocity propagating in narrow channel under different channel gap and wall temperature parallel plane are simulated, and the quenching distances under different conditions are obtained. The numerical results are compared with the experiment in this paper and the literature. The data are consistent with each other, which indicate that the numerical method in this paper is feasible. According to the analysis of the mass numerical datas, the rules of premixed flame propagating and quenching in narrow channel are obtained.The change of temperature and species concentration is shown in detail, and the unstable phenomenon is found when premixed flame propagates in narrow channel.Special attention is devoted to the influence of flame velocity, channel gap and wall temperature to quenching distance. Quenching distances under different conditions are got. For any specific flame, when the flame velocity is small and the channel is narrow, the quenching length becomes smaller compared with the case of high inflow velocity and broad channel. The quenching length is larger for the higher temperature of wall at the same flame velocity and channel gap. The larger the flame velocity and channel gap, the more distinct the influence of the wall temperature on quenching length.The relationships between the quenching distance and flame velocity, channel gap, wall temperature are as follows,G V TwDimensionless constant C of these factors is uncovered. The abac dimensionless constant C is worked out. Quenching distance of different velocity can be easily calculated, according to dimensionless formula and constant C.The premixed flame propagating and quenching in narrow channel has been revealed and the rules of quenching, when flame propagating in narrow parallel channel, also have been given. The corresponding dimensionless relationships obtained can be useful for the design and application of the flame arrester. These studies have positive effect on the development of explosion suppression theory and the application of explosion suppression technology.