Abstract: Reasonable distribution of exhaust volume is of greatimportance to smoke control and fire safety in large-scale hangar. An exhaust volume "polluted area ratio" distribution method was put forward and the corresponding calculation model of distribution was given based on the characteristics of smoke concentration distribution in large-scale hangar. To prove the superiority of the exhaust volume "polluted area ratio" distribution method, a large-scale hangar in Wuhan was taken as an example for the comparison analysis of equal exhaust volume distribution and "polluted area ratio" distribution. The visibility, the velocity distribution at the center section, the cross-sectional distribution of smoke concentration near the exhaust outlet, and the variation of temperature and carbon monoxide concentration near the ignition point were simulated by FDS software. The simulation results showed that when the exhaust volume "polluted area ratio" distribution method was used, the visibility could be significantly improved in hangar 600 s after stable combustion of fuel. The backflow and accumulation of smoke under the ceiling was almost disappeared. Near the exhaust outlet, the smoke concentration in the section was low and evenly distributed. Furthermore, the temperature and carbon monoxide concentration near the ignition source were significantly decreased. It indicated that the "polluted area ratio" distribution method is a new way to achieve rapid smoke extraction and improve the fire-fighting safety in hangar effectively.

Key words: large-scale hangar, exhaust volume distribution, fire smoke, numerical simulation