| Summary: | 碩士 === 國立高雄第一科技大學 === 環境與安全衛生工程研究所 === 102 === Fire spread in high rise buildings occurs if flames emerge and extend on the facade of the building to cause ignition in floors above the floor of fire origin. Considerable work has investigated the heat exposure onto the facade owing to flames emerging from a door-like opening in an enclosure. However, the heat exposure to the external facade from window-like opening locations has not been incorporated into current engineering fire design methods. In this study, experiments in small scale enclosures having various opening shapes and locations were underpinned for flames on facade emerging from ventilation controlled fire at the floor of fire origin. To limit uncertainties, a propane gas burner was used to produce controlled heat release rates (30, 40 and 50 kW) as fire source. The size of opening (in W×H) were 20×10 cm, 10×20 cm and 20×20 cm. Actual heat release rate, gas temperature inside the enclosure, heat flux on the facade wall, and flame contours were measured. Our experimental observations and data show that the shape of opening strongly influenced the combustion conditions, and two categories were found, giving combustion primarily outside the enclosure and combustion both inside and outside the enclosure. Two sets of correlations for the two categories were derived. For the category of combustion both inside and outside the enclosure, the heat flux on the facade from window-like openings was close to that from door-like openings. The external flame heights are very close in the experiments with the same opening geometry, and fuel supply rate. The highest heat flux always occurs with lower opening because the lintel barrier caused gas fuel to accumulate in the enclosure. When the gas fuel flowed out, the cool gas fuel temperature has been heated into hot gas fuel. Further, for the category of combustion outside the enclosure, a series of correlation was provided.
|
|---|
