CO_(2)驱动下NaHCO_(3)对甲烷爆炸特性的影响

Effect of NaHCO_(3) on methane explosion characteristics driven by CO_(2)

为了研究在CO_(2)气体驱动下NaHCO_(3)粉体浓度对甲烷-空气混合气体爆炸特性的影响,在1 m^(3)球形爆炸容器内,以当量比为1的甲烷-空气混合气体为抑爆对象,开展了CO_(2)驱动下不同浓度NaHCO_(3)粉体抑制甲烷爆炸试验,并结合最大爆炸压力、最大升压速率、到达最大爆炸压力的时间和爆炸火焰传播速度分析了CO_(2)驱动下不同浓度NaHCO_(3)粉体的抑爆效果。结果表明:在当前试验喷粉压力下,由于喷射气体会产生湍流扰动,喷射空气会增强甲烷爆炸,而喷射CO_(2)对甲烷爆炸具有一定的抑制作用,更适合做驱动气体;随着NaHCO_(3)粉体浓度的增加,NaHCO_(3)的抑爆效果增强,当NaHCO_(3)粉体浓度较低时,抑爆效果较差,其中添加100 g/m^(3) NaHCO_(3)粉体仅使甲烷最大爆炸压力下降18.7%,而当NaHCO_(3)粉体浓度超过200 g/m^(3)时表现出明显的抑爆作用;基于热重分析结果,从物理和化学两个方面分析了CO_(2)驱动下NaHCO_(3)粉体抑制甲烷爆炸的机理。

To study the impact of NaHCO_(3) powder concentration on the explosion characteristics of methane-air gas mixture driven by CO_(2),we conducted an explosion suppression test in a 1 m^(3) spherical explosion vessel.In this test,we used a methane-air gas mixture with an equivalent ratio of 1 and different concentrations of NaHCO_(3) powder to suppress methane explosion driven by CO_(2).By evaluating the maximum explosion pressure,maximum pressure rise rate,time to reach the maximum pressure,and flame speed,we analyzed the explosion suppression effect of various NaHCO_(3) powder concentrations driven by CO_(2).The findings are as follows:under the current test dusting pressure,the jet gas creates turbulence disturbances,while the jet air enhances methane explosion;however,the jet CO_(2) exhibits a certain inhibitory effect,making it a more suitable driving gas;as the concentration of NaHCO_(3) powder increases,its inhibitory effect becomes more pronounced;lower concentrations yield poor inhibition.For instance,the addition of 100 g/m^(3) NaHCO_(3) powder only reduces the maximum explosion pressure of methane by 18.7%.However,when the concentration surpasses 200 g/m^(3),the inhibition effect becomes evident;additionally,we conducted thermogravimetric analysis to explore the mechanism of methane explosion suppression by NaHCO_(3) powder driven by CO_(2).Both physical and chemical aspects are taken into consideration.