初始温度和压力对排污空间甲烷-空气混合物爆燃特性影响的模拟研究

市政排污空间作为城市公共基础设施的重要组成部分,易积聚可燃气体形成爆炸性环境。结合排污空间的特殊环境条件,采用Fluidyn-MP多物理场数值模拟软件,建立了20 L球形爆炸罐分析模型,通过改变初始温度和初始压力,对排污空间甲烷-空气混合物爆燃特性及其变化规律进行模拟研究。结果表明:初始温度升高导致甲烷-空气混合物最大爆炸压力降低,缩短了到达最大爆炸压力的时间;初始压力增加导致最大爆炸压力急剧升高,并延长了到达最大爆炸压力的时间;最大爆炸压力对初始压力的敏感程度远大于初始温度的影响。此外,随着初始温度和初始压力的升高,爆炸火焰平均传播速度增加,而火焰传播速度对初始温度较敏感。

Simulation research on influence of initial temperature and pressure on deflagration characteristics of methane air mixture in drainage space

As an important component of urban public infrastructure, the municipal drainage space is easily to accumulate the combustible gas and form the explosive environment. Combined with the special environmental conditions of drainage space, an analysis model of 20 L spherical explosion tank was established by using the Fluidyn-MP multiple physical field numerical simulation software. Through changing the initial temperature and the initial pressure, the deflagration characteristics and their variation laws of methane air mixture in the drainage space were simulated. The results showed that the increase of initial temperature resulted in the decrease of the maximum explosion pressure of methane air mixture, and shortened the time to reach the maximum explosion pressure. The increase of initial pressure resulted in a dramatic increase of the maximum explosion pressure, and prolonged the time to reach the maximum explosion pressure. The sensitivity of the maximum explosion pressure to the initial pressure was much greater than that of the initial temperature. Furthermore, with the increase of initial temperature and pressure, the average propagation velocity of explosive flame increased, and the flame propagation velocity was relatively sensitive to the initial temperature.