The effect of varying the height of the inlet and outlet vent on fire protection in NPPs

الملخص EN

An uncontrolled fire in a nuclear facility can be a very serious event.

The majority of fire dynamics, fire risk evaluations will focus on shutdown cables because of their thermal fragility.

Due to the importance of shutdown cables that pass in the in pump room in a nuclear power plants NPP, it is important to study the parameters related the ventilation system in the pump room to reduce the risk of fire.

It is of great importance to protect the insulation of the shutdown cables in NPPs.

Therefore, the present study numerically investigates the effect of vent opening location of the ventilation system specifications on the heat transfer in the pump room during fire.

Three dimensional ANSYS- FLUENT Computational Fluid Dynamics (CFD) simulations with Realizable k-e turbulence model is used in the study.

Three different domains of the vent opening location are numerically studied to enhance the heat transfer in the closed pump room.

The results revealed that the heat transfer enhancement increases as the difference between inlet and outlet vent which leads to low inlet velocity.

This, in turn, reduces the feedback on the fire.

Furthermore, the results show that, to protect the cable insulation, the outlet vent opening should be far from the insulation location and above the inlet vent