Study On Energy-saving Of Double-tunnel Complementary Ventilation Of Highway Tunnel Using Traffic Wind

In the operation of highway tunnel,the function of ventilation system is very important to ensure good air quality.At present,the longitudinal mechanical ventilation is widely used,compared with horizontal ventilation,the energy saving effect has been greatly improved,but the operating power cost is still high.The traffic wind generated by vehicle operation can supplement the ventilation volume of mechanical air to realize energy saving.In highway tunnels,because of traffic flow,longitudinal slope and other factors,the air quality difference between two tunnels is brought.Therefore,it is an effective way to realize the complementary ventilation of double tunnels by traffic wind.This paper takes Xianghe tunnel of Hangzhou-Shaoxing Taizhou expressway as the supporting project,analyzes the equivalent traffic wind characteristics under different traffic flow conditions by cluster analysis of traffic status and full-scale numerical simulation experiment,and designs a two hole complementary traffic ventilation scheme in Xianghe tunnel operation period.The main contents are as follows:(1)Based on the actual traffic flow data of Xianghe tunnel,the paper classifies the traffic operation state of Xianghe tunnel into three typical states by using density and speed as cluster index,and combining the density speed curve with clustering results.The traffic operation state of Xianghe tunnel is divided into three typical states.Based on this,the traffic wind simulation conditions are divided.(2)The model is validated by using ANSYS/FLUENT software,tunnel model and vehicle model are established according to the actual size,and sliding moving grid technology is selected.The paper studies the traffic wind characteristics of different models under the influence of vehicle speed and vehicle model on traffic wind from the two angles of vehicle center line and tunnel vertical plane,and obtains the relationship between vehicle speed and average traffic speed;The paper analyzes the process of traffic wind changing with time in different parts of the vehicle.Through the nonlinear fitting of data,the change characteristics of traffic wind are obtained.The numerical simulation of the traffic wind of the fleet is carried out,and the influence of the traffic flow speed and density on the traffic wind is analyzed.The equivalent traffic speed and ventilation uniformity of the three traffic operation states are calculated.(3)The two hole complementary ventilation scheme of Xianghe tunnel is designed,and the control method of the position and quantity of the cross channel is given.The ventilation volume generated by traffic wind and mechanical ventilation are linearly superimposed.As the design air volume of Xianghe tunnel,the two tunnel complementary ventilation scheme of Xianghe tunnel is designed.Three control strategies of double tunnel complementary ventilation under traffic operation are given.The energy saving effect of the scheme is analyzed.The average ventilation volume can be saved by 15.13% in a day,and the energy saving effect is obvious.The research results can provide theoretical support for the promotion of the two-way complementary ventilation method.