温度和浓度对甲醇喷雾爆炸特性参数的影响

Effects of temperature and concentration on characteristic parameters of methanol explosion

采用20 L球形喷雾爆炸实验系统,探究甲醇在不同环境温度、物料温度及喷雾浓度下的爆炸特性规律。结果表明:20 L爆炸球内甲醇喷雾液滴爆炸极限范围为118.8~594.0 g/cm^3,与纯气相爆炸极限范围(78.6~628.6 g/cm^3)相比,甲醇喷雾液滴爆炸极限范围较窄,喷雾液滴的爆炸敏感性比纯气相甲醇蒸汽低。随着爆炸球内环境温度的升高,甲醇喷雾爆炸极限范围变宽,受限空间内甲醇气液喷雾点火成功概率增大。当甲醇物料自身温度或爆炸容器内环境温度保持不变时,相应爆炸特性参数在Φ=1.8拐点处均呈现先增大后减小的趋势。当Φ=1.8时,甲醇喷雾爆炸存在最大超压峰值。环境温度、物料温度的升高可以提高雾化质量,促进扩散燃烧。但是环境温度的变化较之物料温度的改变对于甲醇液滴喷雾爆炸特性参数的影响更为显著。环境温度和化学当量比二元变量共同影响着甲醇喷雾爆炸强度值,当Φ=1.8,环境温度为303.15 K时,甲醇的喷雾爆炸强度大于甲烷气体爆炸的爆炸强度。

The explosion characteristics of methanol under different ambient temperature, material temperature and spray concentration were investigated by using the 20 L spherical explosion experiment system. The results show that the explosion limit of methanol spray droplets in the 20 L explosion vessel is 118.8.594.0 g/cm^3. Compared with the limit range of pure gas explosion (78.6.628.6 g/cm3), the limit range of methanol spray droplets explosion is narrower, and the sensitivity of spray droplets is lower than that of pure gas methanol vapor. As the ambient temperature in the explosion vessel increases, the limit range of methanol spray explosion becomes wider, and the probability of successful ignition of gas-liquid spray in the confined space increases. When the temperature of the methanol or the ambient temperature of the explosion vessel remains unchanged, parameters of the corresponding explosion characteristic firstly increase, and then decrease after the inflection point of Φ=1.8. When Φ=1.8, there is a maximum over pressure peak in the methanol spray explosion. The increasing ambient temperature and material temperature can improve the atomization and then promote diffusion combustion. However, the effect of ambient temperature is more significant than the factor of material temperature on the characteristic parameters of methanol droplet spray explosion. The ambient temperature and stoichiometric ratio affect the strength value of methanol spray explosion. When Φ=1.8 and the ambient temperature is 303.15 K, the intensity of methanol spray explosion is greater than the intensity of methane gas explosion.