Effect of smoke exhaust openings placement direction of tunnel ceiling mechanical exhaust system

摘要

The numerical mode was constructed on the basis of a 7m-length with 1/10th scale model of subway platform channel. Firstly, the temperature and thickness of smoke layer under the smoke exhaust opening of different placement direction are simulated by using numerical simulation software. In this paper, the regulation of changeable temperature and thickness of smoke layer under the smoke exhaust opening is studied by changing the smoke exhaust rate. Then the Origin was used to fit the smoke layer thickness data obtained by numerical simulation. The model used the same fire heat release rate and the smoke exhaust opening size. The results show that the smoke exhaust rate of the smoke exhaust openings which are horizontally placed is larger than that of the smoke exhaust openings which are placed longitudinally. And the model for estimating the smoke layer thickness in the horizontal direction of smoke exhaust openings is y = y_0 + Ae~(R_0X). The model for estimating the smoke layer thickness in the longitudinal direction of the smoke exhaust openings is y = e~(a+bx+cx~2).