Smoke Management Characteristics in a Road Tunnel with Different Scenarios of Exhaust Fans and Solid Curtains

Abstract

The continued condensation of the smoke emitted from the fire arising through the road tunnels leads to many dangers, the most important of which is a loud explosion that may extend outside the tunnels and be a fatal factor for innocent people due to poor design that leads to loss of safety. Also, the increased concentration and level of smoke inside the long tunnels lead to poor visibility for vehicle drivers, in addition to a lack of oxygen and more CO₂, causing a catastrophe to increase the number of deaths of tunnel occupants. Also, increasing the concentration and level of smoke inside the long tunnels leads to a lack of visibility, in addition to a lack of oxygen, which is a cause of a catastrophe with the death of the tunnel’s occupants. To overcome these risks, controlling the smoke generated while directing them away from the level of visibility of tanker truck drivers has become an urgent necessity to save lives and reduce the level of environmental pollutants to achieve safety. The present research aims to conduct a numerical investigation of smoke management due to solid curtains and a transverse ventilation system on smoke condensation leading to blowouts inside a road tunnel with tanker trucks. The FDS version 2018 code is used for modeling the numerical simulations with model validation performed through open literature studies. Different important parameters of temperature distribution, visibility level, and carbon monoxide concentration through tunnels have been studied. Four suggested scenarios are developed, simulated numerically, and discussed at a horizontal road tunnel for 600 seconds when achieving steady-state conditions. The road tunnel is a rectangular cross-section area with a 10 m width and 5 m height. A release heat rate of 100 MW fire is considered equivalent to a burning tanker, while a fixed position of generated fire at 300 m from the road tunnel entrance is supposed. Increasing the volumetric flow rate of exhaust fans with the use of solid curtains (Scenario-D) leads to enhancing the visibility level, decreasing the concentration level of CO, and accordingly safe people through tunnels during a fire with a rate of 100 MW.