Smoke control engineering is closely linked to safety objectives. It is important to maintain conditions compatible with the evacuation of users for a sufficient period of time and then to maintain conditions that facilitate the intervention of firefighters. The engineering of smoke control is very complex, the lethal nature of smoke and the presence of the public in buildings require very strict standards for smoke control.

For this mission, the EOLIOS team has provided its expertise in the engineering of smoke removal to improve the design of the University Hospital of Pontoise against fire. In this palliative care unit, patients are unable to move around to escape the fire fumes. The objective of the study was to predict the impact of different door controls on smoke and temperature propagation following several fire starts.

Why carry out smoke control studies in hospitals?

The etudes from desenfumage shave effectuées dyears the hôpitat afin from garantir the sécurity of patients and from staff. Elles permandtent from determiner the meilleures méthodes and solutions from desenfumage for assurer a évacuation rapide and in torte sécurity of fumées and of gaz produits by the incendies which forraient go to produire dyears a hôpital. Elles permandtent également d‘identifier the reefques and the sources from danger potentiels and from developper of solutions from sécurity for the préFriir. The etudes from desenfumage shave également très importantes for s‘assurer that the systèmy from desenfumage shave fonctionnals and peuwind être put in œuvre rapidement and efficacement in case d‘urgence.

Creation of the digital twin for the study of smoke control

For this study, the entire level of the CHU of Pontoise was reproduced with a 3D software. All the ventilation and HVAC systems necessary for smoke removal are taken into account in the modeling. Depending on the scenarios studied, the room doors are left open or not and the fire doors are activated or not. The more accurate the digital twin created, the closer the results will be to reality. The mesh used contains about 10 million elements and is refined in the high gradient areas.

CFD modeling of the different fires

As it is, it is impossible to simulate the lighting of the lights and the way they burn with the software. This makes it an input parameter for the models. Several fires representing several risk areas were modeled for this study: a mattress fire that could be located in a bedroom, an ERP regulatory fire reproducing a start in a storage room and an electrical cabinet fire located in a circulation.

Main results obtained

First of all, fire detection is relatively fast, around 20 seconds, which is in line with expectations.

Then, for the smoke extraction study, the impact of the presence of fire doors is clearly visible. The results of the CFD simulations show 3 distinct evolutions of the smoke distribution. The first moments remain relatively similar in the 3 cases. However, the comparison between the project building and the existing building

highlights the usefulness of fire doors. Indeed, the fumes are much better controlled and partitioned with the fire doors. Moreover, this installation preserves certain spaces from the arrival of fumes. In addition, the correlation between smoke and temperature distribution is significant, with fire doors maintaining more space at room temperature. Therefore, in the scenario of a fire, we strongly recommend the installation of firewall systems.