Performance-based design to smoke extraction in gymnasium of Beijing university of technology
LI Jun-hua (Tianjin fire officer training center, Tianjin 300402, China)
A smoke exhaust design in gymnasium of Beijing University of Technology was demonstrated in this paper by simulation. Potential fire scenarios were first identified and combined with empirical correlations to calculate the needed smoke extraction volume, which resulted in a volume of 477,889m3/hr. Then smoke movement under different fire scenarios was simulated by the CFD method with the smoke extraction volume range from 400,000 m3/hr to 200,000 m3/hr with a descending step of 50000 m3/hr and corresponding mechanical ventilation volume equaled 50% of smoke extraction volume to optimize the smoke management system design. The simulation results showed that in all the cases apparent smoke stratification phenomena were formed and the temperatures of the upper layer were less than 60℃. Smoke layer analysis indicated that smoke could be controlled to stay above the critical height to do no harm to people in the competition hall with the smoke extraction volume larger than 250,000 m3/hr. The final smoke management system was designed with extraction volume of 250,000 m3/hr and mechanical ventilation volume of 125,000 m3/hr, which could met the optimum design requirement.