A fuzzy logic procedure for ventilation control in case of fire in long tunnels

Abstract

Ventilation is a crucial element while managing fire events in tunnels. This paper deals with ventilation strategies to be applied in case of fire in a long tunnel. The Frejus road tunnel has been considered as an application. This is a single tube road tunnel with semi-transversal ventilation. Ordinary and emergency ventilations are operated by using dedicated supply and extraction ducts. The optimal configuration of the ventilation system depends not only on the fire size and its location, but also on the pressure at the portals (which is an important factor in the case of a long tunnel), the traffic, etc. In this paper, some particular scenarios are analyzed. These scenarios correspond to particular fire locations, fire sizes, pressure and temperature at the portals, and traffic. Fuzzy-logic approach is applied in order to generalize the results obtained in these scenarios, so that any event can be managed. Some transient simulations are performed in order to test the control strategy. The values of input parameters selected for the test cases are not coincident with those selected to build the control strategy. Transient simulations allows one to check not only the extension of the tunnel portion occupied by smoke, but also the time required to confine the smoke front.