天然气过江隧道施工过程通风排污数值的模拟

Numerical Simulation of Ventilation and Pollutant Emission During Construction of a Natural Gas Cross-river Tunnel

为保证隧道内施工安全,运用计算流体力学数值模拟技术,研究了天然气过江隧道施工过程中的通风排污方案。研究建立了天然气过江隧道的三维通风模型,以施工人员呼出的CO_(2)浓度和电焊产生的烟尘浓度为评价因子,研究了不同施工阶段污染源的释放位置及浓度对隧道内污染物分布的影响,来评价采用隧道入口送风和隧道内部射流风机共同作用下的通风排污效率。研究发现污染源的释放量对污染物的分布影响最大,污染源的释放位置不同会对隧道内污染物浓度产生一定影响,其中最不利的工况位于隧道两端。

In order to ensure the construction safety in the tunnel,a numerical simulation technique of computational fluid dynamics is applied to study the ventilation and pollutant emission scheme during the construction of the natural gas cross-river tunnel.A three-dimensional ventilation model of the natural gas cross-river tunnel was established,and the CO_(2) concentration exhaled by the construction workers and the fume concentration generated by electric welding were used as evaluation factors to study the effects of the emission location and concentration of pollutants on the distribution of pollutants in the tunnel at different construction stages,in order to evaluate the efficiency of ventilation and pollutant emission under the combined effect of tunnel inlet air supply and tunnel internal jet fans.It is found that the concentration of the pollutant emission has the greatest influence on the distribution of pollutants,and the different locations of the pollutant emission will have a certain influence on the pol utant concentration inside the tunnel,with the most unfavorable working conditions located at both ends of the tunnel.