Abstract: Taking utility tunnel as the research background, a simulation calculation model for fire smoke prevention and control in the utility tunnel was built by PyroSim numerical simulation software and the rules of smoke spread under conditions such as building ceiling screen, changing fire compartmentation tightness, and adding smoke exhaust facilities were explored. According to study results, before the tunnel was filled with smoke, ceiling screens lowered smoke spread rate, and smoke spread rate was inversely proportional to ceiling screen height. When the fire door was opened, fire smoke spread to the adjacent fire compartment, and smoke spread rate was directly proportional to the fire door opening angle. Mechanical smoke exhaust facilities significantly lowered the smoke spread rate by as much as 50%. When the entire tunnel was full of smoke, mechanical smoke exhaust facilities reduced the smoke concentration in the utility tunnel significantly. Smoke layer temperature dropped by as much as 32 ℃ , while visibility improved by as much as 66%. By studying smoke spread in utility tunnel, this paper aims to determine the optimal measures of preventing and controlling smoke spread in utility tunnel. This paper could also provide reference for practical engineering applications in smoke prevention and control in utility tunnel.

Key words: utility tunnel, cable fire, smoke spread