Study on the calculation method of critical smoke exhaust rate for ensuring the exhaust efficiency of fire-induced thermal energy

In the event of a fire, the mechanical smoke exhaust system is adopted to evacuate the thermal energy absorbed by the fire smoke from the affected structure. The thermal exhaust performance of smoke exhaust system is fundamentally determined by a pivotal parameter: the critical exhaust rate of exhaust inlet. In previous studies, the underlying mechanism and the derivation process for determining the critical exhaust rate of exhaust inlet were not presented in a clear and understandable manner. In this study, the critical phenomenon of plugholing influencing thermal exhaust performance is demonstrated. The force analysis of the air drawn through the smoke layer and the mathematical derivation of the critical smoke exhaust rate formula are also conducted. The findings are of significant value for advancing research on improving the exhaust efficiency of fire-induced thermal energy and optimizing engineering design in mechanical smoke exhaust systems.