管道内瓦斯爆炸温度与压力峰值试验研究

Experimental research on the temperature and pressure peak value of the gas explosion in the pipeline

为分析瓦斯爆炸的火焰温度及压力峰值在管道中的传播规律,采用瓦斯管网爆炸测试系统进行试验,通过爆炸压力和爆炸火焰温度采集系统采集数据。在相同点火能量和点火位置的条件下,分析了体积分数对瓦斯爆炸的温度峰值和压力峰值的影响,及温度峰值和压力峰值随管道距离的变化规律。结果表明:当瓦斯体积分数低于9.5%时,温度峰值和压力峰值随瓦斯体积分数增大而增大;同一体积分数下,温度峰值最大值出现在最接近爆源的位置,并呈逐渐下降的趋势,接近爆源的温度峰值下降较明显,随管道延长,温度峰值的下降减慢且趋于平缓;温度峰值与传播距离近似呈三次函数关系;冲击波压力峰值随管道传播呈先上升后下降再上升的波动性变化。

The paper is engaged in an experimental study on the tem- perature and pressure peak value of the gas explosion in its pipeline. As is well known, gas explosion is one of the major disasters in the coal mine production, which is often likely to cause disastrous human casualty and material losses. Thus, we believe it is of the utmost im- portance to study and grasp the regularity and the relation between the maximum tolerable temperature and pressure peak value that is prone to cause the gas explosion in the pipeline. It comes from the said purpose that we have prepared a testing system of gas explosion in the pipeline in hoping to examine and investigate the said testing experi- ment, which is supposed to be made up of an 1 m3 antiknock tank and five 2-m-long antiknock pipelines. The explosion experiment we have laid out is with the methane/air mixture whose concentrations are7%, 7.5%, 8%, 8.5%, 9% and 9.5%, respectively, in hoping to collect the data and values of the explosion pressure and flame temperature of the explosion. What our experiments attempt to do is to analyze and make out the effects of different concentrations of the coal composition, the coal-seam＇s temperature and maximum pressure value on the likely-to-happen explosion in addition to the changing regularity of the temperature and pressure in relation to the distance of pipeline at the same ignition energy and position. The ex- periment and analysis results help to confirm our hypothesis that the temperature and pressure peak value tend to increase with the rise of gas concentrations when the gas concentration is less than 9.5 % , at which the temperature and the pressure peak tends to reach the maxi- mum value when the gas concentration is 9.5 % . It can also be found from the observation window on the antiknock tank that the explosion can reach its most violent stage with the bright flame and the loud ex- plosion sound. The maximum temperature peak value proves to occur at a position which is closest to the explosion source at the same con- centration, and then tends to drop down gradually, though the decline process seems different. On the other hand, the temperature peak in the pipeline also occurs close to the explosion source and then de- creases abruptly along with the extension of the pipeline while the slow and gentle decline of temperature peak has been going on. Based on the fitting function of the temperature peak value which is changing from the propagation distance, it can be concluded that the temperature peak value has a cubic function to the propagation dis- tance. On the other hand, the pressure peak of the shock wave in the pipeline has been found closest to the explosion source, which may not reach its maximum value, but whose volatility tends to increase first, decrease later and then rise again along with its propagation in the pipeline, thus demonstrating a consistent trend with the change of the temperature. Thus, the conclusion gained through our experi- ments can provide a theoretical basis for the exploration of the propa- gation regularity of the gas explosion.