湍流状态下甲烷爆炸极限实验研究

Experimental Study on Methane Explosion Limit in Turbulent State

运用20 L球爆炸特性测试系统对静止和湍流两种状态下的甲烷爆炸极限和极限点附近爆炸压力的变化规律进行了研究。结果表明:爆炸前气体状态为静止时,甲烷爆炸极限范围为4.83%~16.4%,气体状态为湍流时甲烷爆炸极限范围为5.10%~15.8%,相对于静止状态,湍流状态下甲烷爆炸极限范围变小。在爆炸极限附近,湍流状态下的甲烷爆炸压力高于静止状态,压力峰值呈现时间小于静止状态。湍流加快了化学反应速率的同时,促使已燃甲烷产生的热量传递到未燃区域,也会加速热量的散发,加快自由基的销毁,弱化甲烷燃烧能量的积累。

The explosion limit of methane and the variation of explosion pressure near the limit point were studied by using a 20 L ball explosion test system.The results show that the explosion limit range of methane is 4.83%~16.4%when the gas in static state before explosion,and 5.10%~15.8%when the gas in turbulent state.Compared with the static state,the explosion limit range of methane in turbulent state becomes smaller.Near the explosion limit,the explosion pressure of methane in turbulent state is higher than that in static state,and the peak time of pressure is shorter than that in static state.The turbulence accelerates the chemical reaction rate,at the same time,promotes the heat generated by the burned methane to transfer to the unburned area,accelerates the heat emission and the destruction of free radicals,and weakens the accumulation of methane combustion energy.