A gas-turbine enclosure requires ventilation for several functions at the same time. Heat released by the turbine and auxiliary equipment must be removed, while any accidental gas release must be diluted and discharged so that hazardous local concentrations are avoided.
FlowMotion used CFD to analyse the three-dimensional airflow, temperature distribution and gas dispersion inside the enclosure. The model included the relevant supply and extract openings, internal equipment and heat sources.
A sufficient total ventilation volumetric flow does not automatically guarantee safe conditions everywhere. The local airflow distribution is decisive: recirculation zones or poorly ventilated regions can allow heat or released gas to accumulate locally.
Temperature differences also produce density differences and buoyancy, which influence the ventilation flow. Heat transfer from hot equipment can include convection and, where relevant, thermal radiation. Flow resistances of components can be represented appropriately within the CFD model.
The calculations made it possible to compare ventilation concepts on the basis of local velocities, temperatures and gas concentrations and to identify regions requiring improved air supply or extraction.
