泄爆口对管道内氢气火焰传播规律影响的数值模拟

Numerical Simulation of the Influence of Vent on Hydrogen Flame Propagation in Pipeline

为了减少氢气爆炸事故造成的损失与破坏,基于大涡模拟(LES)模型和Zimont燃烧模型,研究泄爆尺寸和泄爆口位置等对受限空间中氢气燃爆特性的影响。结果表明:在火焰通过泄爆口的过程中,泄爆口的排放作用会导致火焰锋面发生畸变。当火焰前锋位于泄爆口前方时,火焰受正向流场的牵引加速传播。当火焰锋面通过泄爆口时,受反射波及垂直流场的共同作用,各工况火焰传播速度出现大幅下降。当火焰前锋位于侧泄爆口后方时,仅当泄爆口距点火端1 m时,泄爆管道内火焰传播速度出现大幅度波动,其余泄爆工况内火焰皆保持低速传播至管道末端。泄爆口的泄压效果与泄爆口尺寸呈正相关,当泄爆口尺寸较小时,泄压效果受泄爆口所在位置的影响很大;而当泄压口尺寸较大时,泄压效果受泄爆口所在位置影响较小。

In order to reduce the damage caused by hydrogen explosion accident,based on the Large Eddy Simulation(LES)model and Zimont combustion model,this paper studied the effects of detonation conditions such as vent size and vent location on hydrogen detonation characteristics in confined space.The results show that in the process of the flame passing through the side vent,the position of the side vent can affect the leading role of the side vent discharge effect in the flame front distortion.When the flame front is in front of the side vent,the flame is accelerated by the traction of the positive flow field.When the flame front passes through the side vent,the flame propagation speed under various working conditions is greatly reduced due to the combined action of reflected wave and vertical flow field.When the front of the flame is located behind the side vent,the flame propagation speed fluctuates greatly only when the side vent is 1m away from the ignition end,and the flame propagation to the end of the pipe is kept at a low speed in other venting conditions.The pressure relief effect of the side vent is positively related to the size of the side vent.When the size of the vent is small,the pressure relief effect is greatly affected by the location of the vent.With the increase of the size of the side vent,the pressure relief effect of the side vent is almost not affected by its location.