Fire Safety Science Digital Archive

This work deals with smoke movements between two mechanically ventilated compartments interconnected by a vent. Based on large scale fire tests, it discusses the effect of vent flow on smoke stratification. The tests concern a 97kW propane fire in a 120m3 enclosure connected to an adjacent 170m3 enclosure, both mechanically ventilated. The renewal rate is the varying parameter (from 2.3h-1 to 8h-1) typical to operating conditions in nuclear installations. The present contribution investigates the effect of the vent flow on the smoke distribution in both rooms. The temperature and species concentration distributions are analyzed. The effect of ventilation flow rate on the smoke filling and the smoke distribution in both rooms is presented. From mass balance equations, an indirect method is proposed to compute the flow rates at vent (net, upward and downward) only from gas temperatures and species concentrations in both rooms without considering direct measurements at the vent. This indirect method is compared to a direct method (computation of flow rates from spatial integration of temperature and velocity field at the vent cross section). The analysis discusses the application of this indirect method for large scale fire test experiments.