A Study on Smoke Behavior in a Compartment with Sprinkler System Activation -Simple Predictive Method on Mass Flow Rates Based on Experimental Study-

Abstract

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.