R&R Consult carried out CFD simulations of ozone leakage in a ship engine room in collaboration with Ankron Water Services GmbH. The purpose was to model the distribution of ozone after a pipe breach. This was used to document safety aspects and evaluate the emergency shut-off system.

Machine room and pipe outline from Ozone generator

We simulated the engine room, which was connected to the rest of the ship via four doors. Inside the room were four ventilation fans, which continuously supply the room with fresh air. Finally, the room contained a pipe network connected to an ozone generator. The pipe network and generator were both initially filled with compressed ozone. Upon pipe breach, a section of the pipe network opened and ozone in the generator and pipe network was free to enter the engine room. After a short period of time, the emergency shut-off system would stop the supply of ozone.

Ozone distribution before shut-off

After shut-off, the ozone had spread further into the engine room due to the initial burst from the breach. The distribution of ozone over time was documented using 1 ppm isosurfaces. Later, the continuous air supply from the ventilation would cause the ozone to dilute towards non-dangerous concentrations.

Ozone distribution after shut-off

The CFD simulation was conducted as a time-dependent solution with a species sub-model for tracking the distribution and dilution of ozone in the engine room. The results provided vital information on safety aspects in case of a rupture as well as the performance of the shut-off system.

 

Ozone distribution during dissipation

 

Animation with envelope of volumefraction