Experimental studies on smoke control with mechanical exhaust at high level in a cabin fire

摘要

Although the cabin design is widely used for providing fire safety in big public transport terminals in the Far East, there are concerns on this design concept. Very few full-scale burning tests on the design were reported in the literature. Smoke exhaust system might be put at high or low level. In this article, full-scale burning tests were carried out to study smoke control with mechanical exhaust at high level in a cabin fire. A cabin of length 3 m, width 4 m, and height 3 m was constructed. Smoke temperature, smoke layer height in the cabin, and velocity in the fan duct were measured with different heat release rates and heights of the ventilation opening. Twelve sets of tests were carried out with results reported in this article. Experimental results indicated that when the height of the ventilation opening was high, the calculation results of McCaffrey plume correlation were lower than the experimental data. When the height of the ventilation opening was low, the calculation results of McCaffrey plume correlation were higher than the experimental data. The calculation results of McCaffrey plume correlation agreed well with the experimental data in the intermittent flame zone. McCaffrey plume correlation used in cabin design should be revised with the coefficient concerned. Further, empirical correlation on the flow rate of fans in controlling smoke not to spill out from the cabin was derived based on the experimental data.