ASSESSMENT OF THE GAS COOLING CAPABILITIES OF COMPRESSED AIR FOAM SYSTEMS IN FUEL- AND VENTILATION-CONTROLLED COMPARTMENT FIRES

摘要

The objective of this study was to assess the cooling capabilities of the compressed air foamsystem (CAFS), as an alternative suppression agent to water mist, in fuel- and ventilation-controlledcompartment fires. Two compartment fire behaviour training (CFBT) cells with dimensions of 12mlong × 2.4m wide × 2.4m high and 6m long × 2.4m wide × 2.4m long were used, respectively, for thefuel- and ventilation-controlled experiments. Wooden pallets and chip boards were used as fuels. Inaddition to the CAFS, tests using water mist (the traditional suppression agent) were also conducted.Tests were video recorded and the development of temperature inside the units was also recordedusing thermocouples. A comparative analysis of the results by the CAFS and water mist is conductedbased on the temperature evolution histories and observations from the videos. The results indicatethat the CAFS is more efficient in fire-fighting fuel-controlled fires, whereas for ventilation-controlledfires no noticeable difference is found between the CAFS and water mist. It is however noted that theCAFS does not contribute to or cause a backdraft in ventilation-controlled experiments.