Numerical Simulation for Optimization of Hybrid Fire Ventilation System in Highway Tunnel

With the growth of the length and traffic volume of the highway tunnel, the traditional use of a separate ventilation mode has been unable to meet the comprehensive requirements properly, including aspects of energy conservation, economical efficiency and safe reliability, Etc. This paper, based on the theory of network ventilation, mainly focuses on the integration analysis of the numerical results of the SES program and the detailed check of the CFD simulation on this subject, and is to predict and compute the fire thermal property and the concentration distributions of air pollutants in the advanced hybrid fire ventilation mode, which promotes the interrelated design parameters and operating strategies to be optimized. The results show that the critical air velocity in tunnel is the key parameter for fire ventilation control system. Furthermore, when the air velocity inside is greater than the critical air velocity calculated, it can prevent fume reversing effectively, and greatly reduce the rear temperature of the fire source, which is conducive to the rear evacuation and rescue work, as well as reducing the ignition chances of the vehicles.