Temperature curves
Following temperature curves are used for the description of the gas temperature according to EN 1991-1-2.
Standard temperature curve
The fundamental nominal curve, the temperature of gas in the fire compartment is given by the expression
Where is: | θg |
|
t |
|
Parametric temperature curve
This curve is valid for fire compartments up to 500m2, without openings in the roof and for a maximum compartment height of 4m. The curve consists of two phases: heating phase and cooling phase. Following parameters describe the geometry of the curve:
- The time tlim for maximum gas temperature in case of fuel controlled fire
- The thermal absorptivity for the total enclosure b given by the expression
Where is: | ρ |
|
c |
| |
λ |
|
- The opening factor O given by the expression
Where is: | Av |
|
heq |
| |
At |
|
- The design value of the fire load density qt,d related to the total surface area At of the enclosure.
This curve may be used only for "500°C isotherm method".