Investigation on mechanical exhaust of cabin fire in large-space building  

作　　者：SHI CongLing ZHONG MaoHua HUO Ran 

机构地区：[1]China Academy of Safety Sciences and Technology,Beijing 100029,China [2]State Key Laboratory of Fire Science,University of Science and Technology of China,Hefei 230026,China

出　　处：《Science China(Technological Sciences)》2008年第1期65-76,共12页中国科学（技术科学英文版）

基　　金：the National Natural Science Foundation of China (Grant Nos. 50674079 and 50579100)

摘　　要：A calculation model for mechanical exhaust rate in large-space building in the case of cabin fire is proposed through theoretical analysis. Full-scale hot smoke tests are then performed to study the cabin fire spreading to large-space building at dif- ferent air change rates (ACH). The result indicates that under the standard pre- scribed ACH, the effective air heights in the large spaces are respectively 6, 4 and 2 m in the case of cabin fires of 0.34, 0.67 and 1 MW. Numerical experiment has been conducted using self-developing two-zone model. The smoke control effi- ciency is compared by varying the large space’s air change rate in the case of cabin fires ranging from 0.25 to 4 MW. The calculation results show that the air change rates are respectively 3, 6, 10 and 10 ACH when the smoke layer is kept above 5 m, indicating that the centralized exhaust rates far exceed the standard prescribed value. To address this problem, a set of subsidiary distributed mechanical exhaust installing in the cabin with high fire loads is proposed. The simulation shows that both from the safety and economy point of view, the adoption of subsidiary dis- tributed cabin exhaust design may effectively reduce the demand of designed air change rate for large-space building.A calculation model for mechanical exhaust rate in large-space building in the case of cabin fire is proposed through theoretical analysis. Full-scale hot smoke tests are then performed to study the cabin fire spreading to large-space building at different air change rates (ACH). The result indicates that under the standard prescribed ACH, the effective air heights in the large spaces are respectively 6, 4 and 2 m in the case of cabin fires of 0.34, 0.67 and 1 MW. Numerical experiment has been conducted using self-developing two-zone model. The smoke control efficiency is compared by varying the large space’s air change rate in the case of cabin fires ranging from 0.25 to 4 MW. The calculation results show that the air change rates are respectively 3, 6, 10 and 10 ACH when the smoke layer is kept above 5 m, indicating that the centralized exhaust rates far exceed the standard prescribed value. To address this problem, a set of subsidiary distributed mechanical exhaust installing in the cabin with high fire loads is proposed. The simulation shows that both from the safety and economy point of view, the adoption of subsidiary distributed cabin exhaust design may effectively reduce the demand of designed air change rate for large-space building.

关 键 词：large-space CABIN MECHANICAL EXHAUST SPILL PLUME transfer LAG time 

分 类 号：TU972.4[建筑科学—建筑设计及理论]