| Abstract [eng] |
In this final project it were discussed about GE14 nuclear fuel assembly design components, main two phases flows of water and steam thermal-hydraulic processes and parameters, also examined other studied spacer grid designs and analyzed results of other similar researches. And then it were created three spacer grid designs in SolidWorks with different types of helix flow mixing devices. These geometries were uploaded to ANSYS CFX, then finite element meshes were generated and after setting correct boundary conditions to domains with homogeneous flow and k-epsilon turbulence models, the CFD simulations were made. To evaluate the effect of mixing devices to thermal-hydraulic processes, the obtained results were compared to data of reference model without mixing devices. In this work the focus was on investigating turbulence processes, cross flow effects, heat transfer coefficient variation and pressure drops in fuel channel of different modified constructions. After analyzing the results the most optimal construction was found and to evaluate its benefits in practical use, according to heat transfer coefficient enhancement heat flux in channel was increased and then CFD simulation of full length fuel assembly was made. The results were also compared to reference model and then appropriate conclusions were made. |
