加熱時の散水システムによる建築部材の延焼防止に関する研究:鋼板面上の水膜流による温度上昇抑制効果

摘要

1．序1．1背景建築基準法では，建築物が密集する地域などを想定し，出火建物から隣接建物への延焼，さらに街区火災や市街地火災へ進展することを防止するために，建築物の外壁や軒裏，開口部などの外周部位に対し，防耐火性能を要求している1）．それらは，延焼危険性を低減させるために物理的要因を排除することが基本概念となっており，建築物の外周部位の材料や構法による対応を求める規制となっている2）．%The full scale tests were carried out to grasp behavior of water film supplied by water discharge system under heating conditions. The specimen was a steel plate of 2438 mm height, 1219 mm width and 6 mm thickness. The intermediate furnace at Tokyo University of Science was used as radiation panel. The radiation panel was placed parallel to the specimen at some distance. The experimental conditions have changed the heat flux rate from radiation panel to specimen covered with water film, the water supply rate gushed from water discharge head and so on. The water film was almost uniform from the top of the specimen to the bottom by using this water discharge system. As the results of experiments, the behavior of water film is clearly involved to the water supply rate and the relation could be marshaled by using Reynolds number based on a simple vis­cous layer model. The water film temperature became higher so that the water supply rate decreases. Based on the experiment results the empirical formula has been developed to calculate the temperature-rise of water under any heating conditions.