Performance of Sprinkler in Atria

Abstract

The performance of a sprinkler installed in an atrium roof was evaluated in this paper by considering three points: possibility of activating the sprinkler head, thermal response, and water requirement. Crude analysis us ing the empirical expressions of the fire plume and the zone model CFAST 2.0 were used to study the possibility of activating the sprinkler head. Smoke spreading out from a fire shop to the atrium was discussed. The software DETACT was used to calculate the activation time for the sprinkler heads of different response time indices installed at different ceiling heights under unsteady t-squared fires. Correlation expressions of the activation time with ceiling height, response time indices of the sprinkler head, fire growth coeffi cients, and ambient temperature were derived. The water requirement at the atrium floor was discussed by calculating the trajectories of water droplets. Higher flow rate and pressure are required for discharging the same water den sity at the floor level. Results indicated that installing an ordinary sprinkler system in a high headroom atrium would not be effective in controlling a fire.