Experimental Research on Drag Characteristic of Air Flow Path for ACP-100 Passive Containment Air Cooling System

Passive containment air cooling system (PAS) is an important special safety system for the small modular pressurized water reactor ACP-100. The heat is transferred to the environment by the natural draft air cooling under accident conditions. The flow loss of the air flow paths has an important influence on the heat transfer power of PAS. A one-sixth scale model of PAS air flow path was constructed which was a 90° wedge angle sector of the cylindrical symmetric passages. The pressure distributions at different sections of the model were measured, the drag coefficients were analyzed. The experimental results showed that the total drag coefficients of the four different air inlet paths were almost the same, and they showed a decreasing trend with the increase of Reynolds number. The sleeves had the largest drag coefficient, accounting for about 26%, followed by the air inlet, chimney outlet, the turning and the corridor. The other components had little effect on the pressure loss. Afterward, the aerodynamic modification was carried out, the modification for the turning could reduce the total drag coefficient by 4.5 %. The experimental results of this paper provide necessary data support for the ACP 100 engineering design.