开窗条件对室内天然气扩散影响的模拟研究

Simulation Study on Influence of Window Conditions on Indoor Natural Gas Diffusion

为研究室内燃气泄漏扩散规律及事故防控技术,使用ICEM软件建立了厨房燃气泄漏的几何模型并划分网格,使用FLUENT软件模拟了不同泄漏口尺寸、窗户类型、门窗启闭及通风条件下室内天然气的浓度场及爆炸区域的变化.模拟结果表明:当天然气泄漏速率较低时,只开窗就可以大大降低室内爆炸区域体积,而高泄漏速率时只开启窗户的作用不大;窗户上部安装和中部安装对室内天然气浓度影响不大,窗户面积对降低天然气浓度影响较大;门窗开启且向室外通风时,0.5m/s的微风即能保证高泄漏速率时的室内天然气浓度不超标,当室内天然气浓度很高时开窗通风也能迅速使其降至安全水平.

In order to explore the gas leakage and diffusion in a residential kitchen,so as to prevent and control this kind of accidents,the method of numerical simulation was used,and a numerical model was set up by ICEM and FLUENT.With the help of the numerical simulation,the gas concentration distribution and the explosible volume were obtained under different conditions.The variable conditions in computation include size of the leakage hole,opening or closing of the window and wind velocity.According to the simulation results,some conclusions are obtained as follows.The opened window can reduce the explosible volume evidently under low leakage rate,but the effect of the window is not obvious under high leakage rate.The effect of the position of the window is not obvious to reduce gas concentration,but doubling the window can reduce the gas concentration obviously.When both the window and door are opened,0.5 m/s wind can keep the gas concentration low enough whether the gas is leaking with high speed or the gas has reached to a dangerous concentration.