With the spreading of the green environmental protection concept, increasing attention has been paid to improving the tunneling environment. In this paper, the distribution characteristics of airflow fields, the diffusion laws of pollutants, and the influence of airflow rate changes on pollutants in tunnels under single-forced ventilation conditions were simulated according to the computational fluid dynamics (CFD) theory. In addition, the reliability of the simulation results was verified through field measurements. A three-stage distribution was observed once the dust concentration stabilized: we noticed areas with relatively low dust concentrations (<300 mg/m³), high dust concentrations (>500 mg/m³), and medium dust concentrations (~400 mg/m³, near the tunnel exit). Meanwhile, after stabilizing, the gas concentration was 0.67%. Properly increasing the airflow rate (Q) can effectively improve the tunnel environment: when Q reached 600 m³/min, the air in the tunnel was effectively purified. However, under a continuous increase of the airflow rate, there is a risk of pollution rebound.We conclude that, to effectively improve the tunnel environment and achieve a sustainable utilization of resources, the optimal operation airflow rate should be 600 m³/min.

随着绿色环保理念的普及，隧道环境的改善越来越受到重视。本文根据计算流体动力学（CFD）理论，模拟了单强制通风条件下隧道内气流场的分布特征、污染物的扩散规律以及气流速率变化对污染物的影响。此外，通过现场实测验证了仿真结果的可靠性。一旦粉尘浓度稳定，观察到三阶段分布：我们注意到粉尘浓度相对较低（<300 mg/m ³）、高粉尘浓度（> 500 mg/m ³）和中等粉尘浓度（~400 mg /m ³）的区域/米³，靠近隧道出口）。同时，稳定后的气体浓度为0.67%。适当提高风量（Q）可有效改善隧道环境：当Q达到600 m ³ /min时，隧道内空气得到有效净化。但在风速持续增加的情况下，存在污染反弹的风险。我们认为，为有效改善隧道环境，实现资源的可持续利用，最佳运行风速应为600 m ³ /min。