Predicting Wall Temperatures in a Smoke Exhaust Duct
Application ID: 35151
A smoke exhaust duct in a building is analyzed. Radiation of a non-gray gas is accounted for with a Radiation in Participating Media interface and the Weighted Sum of Gray Gases Model (WSGG).
The smoke exhaust duct consists of 25 mm plaster walls. Building codes require that the walls must withstand hot fire gases for at least one hour. The fire gases enter the duct at 800°C. After 30 minutes the average temperature of the walls is about 300°C, and after 1 hour 500°C. If gas radiation effects are not included, the wall temperatures are severely underestimated, 100°C after one hour. The results show that the construction would fail from a fire safety standpoint if it were based on a simulation that does not take gas radiation into account.
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