| Abstract [eng] |
The most popular pressurized water reactors generate a significant amount of electricity worldwide. Analysing their performance and optimising working parameters therefore will remain meaningful tasks in nuclear engineering. This paper incorporates description of pressurised water reactor fuel bundles and their assemblies, defines the purpose of each element, thus enabling to select the area of thermal and hydraulic on top of all interim grid spacers in the fuel bundle. The purpose of these mixing vanes is to create local flow obstructions and induce vortexes, which in turn makes the flow more turbulent and enables the fuel rods to give off their generated heat more easily to the cooling water. The tasks of this paper are to make modifications of the geometrical model of the fuel bundle by changing the grid spacer design – changing the mixing vanes’ angle relative to the coolant flow, also to calculate the needed inlet conditions of the system, make evaluation and description of the ongoing physics by using the numerical simulation software ANSYS CFX 15.0. Calculating thermal and hydraulic parameters of the system is also considered as one of the tasks. The main goal is to find out at which angle the mixing vanes create the biggest effect on the reactor efficiency by making heat transfer from the fuel to the coolant more effective, also evaluating the influence to other reactor core parameters is to be analysed. After the numerical simulations are done and the results are calculated, the mixing vane effect for the thermal and hydraulic processes is investigated, the increased efficiency of the reactor is calculated. This paper also includes future recommendations for similar works in establishing the best mixing vane application. The conclusions based on the numerical simulation results are also presented. |
