Numerical Simulation on Impact of New Energy Vehicle Running Proportion on Urban Tunnel Inner Environment

Abstract This study investigates the impact of new energy vehicles on CO concentration in tunnels, as these vehicles produce near-zero emissions compared to traditional fuel vehicles. By using numerical simulation, the research examines the longitudinal distribution of CO under normal and congested traffic conditions. The results indicate that increasing the proportion of new energy vehicles significantly reduces CO emissions, thus decreasing the length of tunnel sections requiring ventilation. Specifically, when new energy vehicles account for 50% of traffic, CO concentrations drop by 56.62% and 53.30% under normal and congested conditions, respectively. These findings offer valuable insights for optimizing tunnel ventilation systems with energy-saving considerations.