The non-uniform inflow structure of reactor coolant pump based on Laser Doppler Velocimetry

Abstract

The hydrodynamic fields generated by the steam generator (SG) head at the reactor coolant pump (RCP) inlet are experimentally and numerically investigated in this paper. The velocity profiles and turbulence intensity rate were obtained with a Laser Doppler Velocimetry (LDV) system. The velocity profiles under non-uniform inflow and uniform inflow conditions were obtained and compared. The numerical results on measurement sections were qualitatively and quantitatively validated against LDV data. The results indicated that the numerical method have a good agreement with the experiments. It can be known from the study that hydraulic performance of pump deteriorates with its inflow. In addition, the velocity profile of non-uniform inflow can be divided into three regions. These regions are constant high velocity region, large velocity gradient region and back flow region respectively. Furtherly, from the turbulence intensity rate analysis, it can be concluded that the non-uniform inflow is highly turbulent, which would bring significant performance changes to the pump.