Thermal hydraulic investigations and optimization on the EVC system of a PWR by CFD simulation

•This study constructs a full CFD model for the EVC system of a PWR.•The complex fluid and solid coupling is treated in the computation.•Primary characteristics of the velocity, pressure and temperature distributions in the EVC system are investigated.•The optimization of the EVC system with different inlet boundaries are performed.

In order to optimize the design of Reactor Pit Ventilation (EVC) system in a Pressurized Water Reactor (PWR), it is necessary to study the characteristics of the velocity, pressure and temperature fields in the EVC system. A full computational fluid dynamics (CFD) model for the EVC system is constructed by a commercial CFD code, where the complex fluid and solid coupling is treated. The Shear Stress Transport (SST) model is adopted to perform the turbulence calculation. This paper numerically investigates the characteristics of the velocity, pressure and temperature distributions in the EVC system. In particular, the effects of inlet air parameters on the thermal hydraulic characteristics and the reactor pit structure are also discussed for the EVC system optimization. Simulations are carried out with different mesh sizes and boundary conditions for sensitivity analysis. The computational results are important references to optimize the design and verify the rationality of the EVC system.