Citation

Yang D, Li P. China Saf. Sci. J. 2022; 32(5): 41-47.

Copyright

(Copyright © 2022, China Occupational Safety and Health Association, Publisher Gai Xue bao)

DOI

10.16265/j.cnki.issn1003-3033.2022.05.0938

PMID

unavailable

Abstract

In order to prevent uncertainly of smoke flow in inclined tunnel fire with longitudinal ventilation, firstly, a theoretical model of critical fan-induced pressure corresponded to only existence of buoyancy-dominated flow pattern Pj,min and only existence of fan-dominated flow pattern Pj,max was proposed through potential function analysis. Then, small-scale experiments were carried out to validate the model's scientificity and effectiveness, and the magnitude of Pj,c, which met critical velocity, were compared with the above Pj,min and Pj,max. The results show that Pj,max is always larger than Pj,c. If Pj,c is adopted in a longitudinally ventilated inclined tunnel, there are two possible flow patterns caused by different fan activation time, one is the pattern that critical velocity is achieved and all of the smoke is exhausted downward, while the other is that buoyancy overwhelms fan-induced pressure rise, and thus part of smoke spreads upstream. If Pj,max is adopted, effective longitudinal ventilation can be finally achieved under any fan activation time. © 2022 China Safety Science Journal. All rights reserved.

Language: zh