南昌红谷隧道通风及洞口污染物排放分析

Analysis on ventilation and pollutant emission at entrance of Honggu Tunnel in Nanchang

通过对隧道需风量计算、通风网络模拟及现场风速测试,得到了隧道各匝道在不同车速条件下的通风量,分析了多匝道风量分配特性;采用隧道出口污染物扩散TOP模式,预测隧道出口不同风量条件下的污染物扩散情况,并实测了隧道出口污染物浓度,分析了洞口排风对敏感建筑附近环境的影响。研究表明,城市隧道通风计算中污染物CO基准排放量取值偏高,需风量计算值偏大。认为在相关标准编制及工程设计中应重视机动车尾气排放中NO_x的基准排放量和浓度控制值;对于多匝道隧道,可以通过诱导交通组织和调节分离匝道风量分配比例,降低距离敏感建筑物较近出口污染物浓度。

Through the calculation of tunnel air demand,ventilation network simulation and field wind speed test,obtains the ventilation volume of each ramp in the tunnel under different vehicle speed conditions.Analyses the multi-ramp air rate distribution characteristics.By means of the TOP mode of pollutant diffusion at tunnel exit,predicts the pollutant diffusion at tunnel exit under different air rate conditions.Measures the pollutant concentration at tunnel exit and analyses the impact of exhaust air at the tunnel exit on the environment near sensitive buildings.The results show that the base emission value of CO is larger in ventilation calculation of urban tunnel and the calculation value of air demand is larger than normal.Thinks that the base emission and concentration control value of NO_x in motor vehicle exhaust emission should be paid attention to in the formation of relevant standards and engineering design.For multi-ramp tunnels,the pollutant concentration at the tunnel exit near sensitive buildings can be reduced by inducing traffic organization and adjusting the air rate distribution of separated ramp.