自然通风条件下室内CO2扩散浓度变化的数值模拟

探究室内危险性气体泄漏后的扩散特性及危害区域的影响,采用CFD软件FLUENT对室内自然通风条件下CO2连续泄漏扩散浓度的变化过程进行了数值模拟,研究CO2扩散过程的浓度场分布和危害区域变化规律,并比较CO2连续泄漏的风洞实验结果与数值模拟结果。结果表明:CO2在重力的作用下,泄漏后向空间的下方扩散,形成气体积聚,浓度逐渐延长,梯度变化较大,出现分层现象,并形成危害区域。随着时间的延长,室内各点的浓度增加,危害区域逐渐变大,并向上方移动;实验数据和模拟结果吻合较好,证明FLUENT可以较准确地模拟室内CO2的扩散过程。

Numerical simulation of indoor concentration change of carbon dioxide dispersion under natural ventilation condition

The diffusion characteristics and the effect of hazard area with fuel gas leak indoors were discussed.The process of concentration change when continuous releasing of indoor carbon dioxide under natural ventilation condition was numerically simulated with FLUENT by computational fluid dynamic(CFD) method.The concentration distribution of carbon dioxide and the law of hazard area change were studied.Simulation values were then compared with wind tunnel experiment data.Experiment results showed that under the effect of gravity gas diffused to lower space,and the concentration of carbon dioxide rose and changed quickly,so that stratification phenomenon and hazardous area were formed.With the increase of releasing time,the hazard area expanded gradually and moved upwards.The results showed that simulation results agreed well with experimental data and that the indoor leaking process of carbon dioxide could be simulated with FLUENT.