Effects of Fire Source Conditions on Vent Flow Velocity and Hot Gas Layer Characteristics in Two Rooms Connected by Vertical Opening

Abstract

In this study, the effects of fire source conditions on the vent flow velocity and hot gas layer characteristics in two rooms (ROOM-I and ROOM-II) connected by a vertical opening (VO-I) were investigated experimentally. In ROOM-II, the vertical opening (VO-II) connected to the outside was installed. The fire sources were located at the centers of ROOM-I and ROOM-II, and the heat release rates were 1.32, 3.32, and 5.21 kW. Regarding the vent flow velocity, when the fire source was located in ROOM-I, the outflow of the hot gas and inflow of cold air occurred in the upper and lower parts of VO-I and VO-II, respectively, which were the same as those of VO-II when the fire source was located in ROOM-II. However, when the fire source was located in ROOM-II, the hot gas in the upper part of VO-I flowed out to ROOM-I and flowed again into ROOM-II. Additionally, the hot gas layer thickness and temperature rise in the fire and adjacent rooms were compared. In the fire room, the case where the fire source was placed in ROOM-I showed a thicker hot gas layer and a higher hot gas layer temperature rise than the case where the fire source was placed in ROOM-II. In the adjacent room, the case where the fire source was placed in ROOM-I showed a thinner hot gas layer and a higher hot gas layer temperature rise than the case where the fire source was placed in ROOM-II. The dependence of the hot gas layer temperature rise on the heat release rate was higher than that of the hot gas layer thickness.