Over pressure systems
In certain areas of a building, which are used for evacuation, (staircases, elevator shafts), it may be necessary to install an over pressure system. In case of fire, this system allows for over-pressure in the relevant space, so that the smoke in this space can not flow into. Thus the escape route for fire-brigades remains free of smoke.
An over pressure system may also be used in an escape tunnel. In such a tunnel, usually located next to a road or railway tunnel, a pressure installation ensures that the tunnel remains free from smoke and heat in case of fire and thus provides a safe escape. These systems are calculated according to EN 12101-6 or in accordance with the basic standards.
To make a prediction on the situation in the parking garage during a car fire, a CFD simulation is executed. To carry out this simulation a 3-dimensional model of the parking garage is set up. Subsequently, technical installations and control strategies are used by using mathematical formulas in the model. When the model is fitted with the corresponding physical parameters, this is ready for simulation. Using a finite volume method the mass, momentum and energy balances are resolved per time step.
The simulation results can be analyzed per time step for different quantities.