Heat Transfer Enhancement In Nuclear Fuel Rod Bundles

A Nano-fluid is the suspension of nanoparticles in a base fluid.Nano-fluids are promising fluids for heat transfer enhancement due to their anomalously high thermal conductivity.At present,there is a significant discrepancy in Nano-fluid thermal conductivity data in the literature.In contrast,Nano-fluid has received very limited attention or is just beginning to attract attention and thermal conductivity enhancement mechanisms of Nano-fluids have not been fully understood yet.Therefore,the reactor's designers may overlook data on the effect of Nano-fluid on the heat transfer in the reactor core.Due to this reasons,this paper emphasizes Nano-fluid simulation with the aim of enhancing the heat transfer between the Nuclear Fuel Rod(NFR)bundles and the coolant.In the first part of this study,a detailed literature review about the thermal conductivity of Nano-fluids is performed.The second part investigates the thermal characteristics of a single-phase Nano-fluid in a nuclear fuel rod bundles and studies the heat transfer between water as coolant and Nano-fluids with different volume percentages.In order to enhance the heat transfer,NFR bundles are modeled and simulated for single prototype NFR,using ANSYS-FLUENT under the assumption of Nano-fluid as a coolant.0.5%and 2%(Volumetric concentration)Al2O3-water based Nano-fluid are used.For the same fluid flow rate,the 2%Nano-fluid provides the highest heat transfer coefficient whereas the water has the lowest heat transfer rate,it is observed that heat transfer coefficient increases as Renault Number(Re)increase.Results show that the Nano-fluids gives better thermal performance than the water.