CFD Modelling of High-Pressure Water Mist System in Road Tunnels

摘要

Fire safety is an inherent part during the road tunnel design. As road tunnels pose an important part of road public infrastructure, their endangering by fire may cause significant life, material or traffic costs. Hence are the fire safety systems in road tunnels under constant development and CFD tunnel fire models are used increasingly as an advanced tool during this process. This paper deals with modelling high-pressure water mist system which is still considered as a latter-day firefighting method in road tunnels. Scenarios created in Fire Dynamics Simulator vary in water mist system operating pressure and nozzle lay-out by constant longitudinal velocity 2 m/s in case of 15 MW small truck fire. The analysis of how these variable inputs effect the simulation results is the main aim of the paper focusing on heat flux and air temperature as main water mist fire suppression parameters. Besides, smoke layer height is monitored as essential parameter in solving the problem of evacuation and fire brigade intervention by road tunnel fires. Obtained data cover expected results in sufficient measure and provide foundation of CFD tunnel fire modelling application and further research in this field.