室内掺氢天然气泄漏分层现象模拟研究

Simulation study on stratification phenomenon of indoor hydrogen-blended natural gas leakage

为探究掺氢天然气在民用住宅厨房内的泄漏扩散规律,利用数值模拟的方法对掺氢比分别为15%,20%,25%,30%的掺氢天然气泄漏扩散过程进行研究,分析厨房空间内水平和竖直方向上掺氢天然气泄漏后其浓度(本文所称浓度为体积分数)分布情况。研究结果表明:在竖直方向上,掺氢天然气浓度与高度呈现正比关系,且在掺氢天然气泄漏0~2700 s,高度为0.5~2.0 m的范围内,其浓度分布差异较大;在水平方向上,除泄漏点正上方临近位置以外,其他区域的浓度分布差异较小;掺氢天然气静置后厨房内出现甲烷和氢气分层现象,甲烷与氢气浓度比值与高度呈现反比关系。研究结果拟为相关实验提供一定的先验条件,同时可为掺氢天然气泄漏爆炸事故的预防及燃气报警器的安装提供一定参考。

To investigate the leakage and diffusion law of hydrogen-blended natural gas in residential kitchen,the leakage and diffusion processes of hydrogen-blended natural gas with 15%,20%,25%,30%of hydrogen blending ratios respectively were investigated by numerical simulation.The distribution of the concentration of hydrogen-blended natural gas after leakage in the horizontal and vertical directions in the kitchen space was studied.The results show that the concentration of hydrogen-blended natural gas in the vertical direction presents a positive relationship with the height,and the concentration distribution varies widely in the range of 0.5 m to 2.0 m.The difference in concentration distribution in the horizontal direction is small except for the location in the immediate vicinity directly above the leakage point.The stratification phenomenon of methane and hydrogen is observed in the kitchen after standing still of hydrogen-blended natural gas,and the ratio of methane and hydrogen concentration presents an inverse relationship with height.The results can provide certain priori conditions for the related experiments,as well as providing guidance for the prevention of hydrogen-blended natural gas leakage and explosion accidents and the installation of gas alarms.