Effect of single-side centralized exhaust on smoke control and temperature distribution in longitudinal ventilation tunnel fires

In the centralized exhaust tunnel, the smoke exhaust fan room is generally built on both sides of the tunnel to discharge toxic smoke from the tunnel. Because the construction of the fan room is complex and expensive, only one fan room can be built in some short-centralized exhaust tunnels, such as the Mawan Cross-Sea Passage in Shenzhen, China. In this paper, a 1:10 single-side centralized exhaust small-scale tunnel was built to study smoke and temperature distribution beneath ceiling under different longitudinal velocities, smoke exhaust volumes and HRRs. The results showed that the smoke in a single-side exhaust tunnel can be effectively controlled at the appropriate smoke exhaust volume with the longitudinal speed at 0.5 m/s; temperature of smoke is less than 80celcius after passing through exhaust outlet. Based on experimental results, a smoke control scheme for a ceiling point exhaust tunnel with one fan room was obtained. The temperature decay beneath ceiling accords with law of exponential attenuation. A calculation model for temperature decay in a ceiling point exhaust tunnel with one fan room was also proposed. The error between the experimental results and the prediction model in this paper is less than 20%.