Control of smoke flow using a jet-fan in an underground car park

Abstract

Ventilation systems are used to provide ventilation for covered car parks and to control the smoke in the event of fire. In this paper the interaction between the fire ceiling jet and the flow driven by jet-fans is studied using CFD simulations. There is a number of parameters that can affect the flow of smoke that need to be considered. To avoid mistakes, fluid flow visualisation is highly required as well as in order to directly compare the different design variants. One of the best option to make flow analysis is to performed Computational Fluid Dynamics simulations (CFD). By CFD it is possible to detailed analyse and keep control of the flow of fluid, heat transfer and other related phenomena. It also helps predict the contamination level of Carbon Monoxide, heat and smoke intensity and distribution. In this study, CFD simulations were used to design, test and compare different design of a fire ventilation system. The research drew attention to the location of jet-fan type fans. The main objective of the study was to assess the impact of jet-fans on fire and to check if it is possible to evacuate people from the garage in less than 10 minutes. The simulation results emphasize the important location of the different elements on the functionality and efficiency of a fire protection system. Due to the evacuation of people from the garage, the simulation results suggest a 10 minute safety time for evacuation. During this period, high visibility and oxygen concentration, as well as low temperature allow for rapid evacuation.