Enhancement of heat transfer in a typical pressurized water reactor by different mixing vanes on spacer grids

Abstract

The flow mixing devices on a grid spacer are designed to enhance the turbulence and heat transfer in sub-channels. The present study evaluates the effects of different mixing vane configurations on flow pattern and heat transfer in the downstream of the mixing vanes in the sub-channels of fuel assembly. This is done by obtaining velocity and pressure fields, turbulent intensity and the heat transfer coefficient using a three-dimensional CFD analysis. Two blade groups, two-dimensional and three-dimensional, were modeled. The two-dimensional blades are classified in ring type, diamond type, square type, homographic type and multiply type. Three-dimensional blades containing split vane, ripped open, trumpet shaped and split trumpet shaped are applied in a 2×2 rod bundle array. Also, a 3×3 rod bundle array is modeled to evaluate the neighborhood effects on the thermo-hydraulic parameters. The latter model …