Heat Transfer Analysis of Nanofluid Based Coolant Used in the Sub-Channel of Fuel Assembly of a Pressurized Water Reactor

摘要

Nano fluids are found as one of the important suspension nanoparticles in the solution that show a very significant improvement on (boiling) critical heat flux (CHF) at moderate concentrations of nanoparticles. CHF is considerate to be the maximum limit of nucleate boiling. Moreover, CHF is the most essential factor for improving the heat transfer mode, and thus the reactor performance. The goal of this study is to investigate the use of nanofluid as a component of the primary coolant in the pressurized water reactor (PWR) to improve heat transfer. This enhances the heat transfer characteristics of the reactor core and also prevents the core from melting in an emergency situation. In current and future PWRs, the nano fluid application could allow substantial power upgrades, thereby enhancing their economic efficiency. In addition, the use of nanofluids could allow as much as 20 percent increase in power density in latest generation plants without any change in the design of the fuel assembly. In this analysis, it has been found that almost 1-4% increase of Nano particle with base fluid caused a substantial escalation in heat transfer, which can reduce the overall bulk temperature and the temperature of the fuel rods as well. In addition to this, turbulent kinetic energy and velocity have been developed and investigated for different percentages of Nano fluid along the sub channel of a PWR fuel assembly, which is crucial in case of design. Overall, there has not been done much CFD based work regarding the Nano fluid application in the coolant of the sub channel, thus impact of nano fluid inclusion in the base water for heat transfer escalation inside a sub channel of a PWR is a crucial topic for investigation, in addition to this, necessary Computational Fluid Dynamics (CFD) relevant data base has been generated for further investigation. Hence, the present CFD analysis represents the novelty and uniqueness of the work for the inclusion of nanofluid with water.