重气泄漏扩散的影响因素分析

Analysis of Influence Factors for Dense Gas Leakage Dispersion

根据计算流体力学原理提出高原山区城市重气流动和扩散过程的数学物理模型。在给出计算所需的定解条件,采用SIMPLE算法,模拟流场与风洞实验结果吻合良好的情况下,利用该模型分析了重气密度、大气压及气温因素对重气流动和扩散过程的影响。结果表明,重气密度越大,重气效应越明显;在泄放质量流率等其他条件不变的情况下,大气压越小,气温越高,湍流扩散系数越大,同一地点的重气浓度越大,标准大气压下的重气浓度比高原地区810 hPa大气压下的低6.2%-24.7%,平均低19.8%,0℃时的重气浓度比23.5℃时的低6.9%-8.9%,平均低8.2%。

The mathematical physics models were founded to reflect the physical phenomenon in the air turbulent flow and dispersion with dense gases in the plateau mountainous city,according to the principles of CFD.The condition to determine the solution was given.They were solved by means of a method based on the SIMPLE algorithm.The influence of dense gas density,air pressure and air temperature on the process of dense gas dispersion was analyzed by this model,the simulation result of flow field and concentration field was verified by the wind tunnel experiment.It shows that the the larger the density of dense gas is,the more obvious the effect of dense gas is.With the same mass flow rate and other condition,the larger the air pressure is,the lower the air temperature is,and the higher the air turbulent dispersion coefficient is,the bigger the dense gas concentration at the same site is.The concentration of dense gas at the normal air pressure is less 6.2%～24.7%,average 19.8%,than plateau with 810 hPa,and the concentration of dense gas at 0 ℃ is 6.9%～8.9% or average 8.2%,less than plateau with 23.5 ℃.