Numerical Simulation of the Propagation of Premixed Gas in a Pipe Flame Arrestor

Abstract In this paper, a numerical model of the propagation process of premixed gas in a pipeline flame arrestor is established and solved. The numerical simulation results show that the flame propagation velocity and pressure variation curves of the propane-air premixed gas are the same as those of the ethylene-air premixed gas. The flame front and pressure oscillate periodically throughout the process, and the flame speed oscillates down when the flame front reaches approximately the middle and rear of the pipe. In contrast, the flame velocity versus pressure curve for the explosion of hydrogen-air premixed gases is quite different, with the flame propagating at an almost constant velocity in the initial stages, accelerating suddenly when the flame front reaches near the middle of the pipe, reaching a peak, followed by an accelerated decrease in flame velocity; at the middle and rear of the pipe, the flame once again propagates at a nearly constant velocity, and as the flame is quenched, the flame propagation velocity once again accelerates and decreases. The explosion pressures of the propane-air and ethylene-air premixed gases at each measurement point in the pipeline increase linearly with the initial pressure, and the explosion pressure appreciation is very close. The explosion pressure of hydrogen-air premixes increases significantly with increasing initial pressure, but the increase decreases slightly. The increase in initial pressure increases the flame propagation rate of the premixed gas, and the acceleration effect is significant.