Fire Science and Technology

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Sprinklers generate a flow of downward moving gases from smoke in the upper layer of a two-layer zone within a compartment. It is necessary to determine quantitatively the flow of downward-moving gases and fire plume in order to calculate smoke behavior in a compartment with sprinkler activation. As a first, this study proposes a measurement technique of mass flow rate based on the gas analysis method since it is difficult to understand through conventional methods. Experiments were conducted on a full scale and the following results were obtained; 1) the mass flow rate of the fire plume grows with sprinkler activation and a flow of downward-moving gases grows as the heat release rate decreases and the amount of sprinkler supplied water increases. 2) A relation between the ratios of the mass flow rate penetrated to lower layer by water droplets to the mass flow rate of watering supply from SP, and of the upper (smoke) layer and the lower layer. As a result, the mass flow rate penetrated to lower layer can be computed when the mass flow rate of watering supply from SP and temperature at the smoke and lower layers are known.

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The concrete-filled steel tubular column without fire protection was initially developed in Europe. Recently, the column has been widely used in buildings in Japan. Because of the differences of the form of the frame and differences of regulations between Japan and Europe, an improved approach is needed to apply the column more extensively in practice. This report presents modeling of the member and frame, based on fire tests and previous research, thermal analysis of the frame during fire, and consideration of on-site planning and execution, as designed by the authors in 47 buildings.

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