Numerical analysis of the journal bearings of Keban Hydroelectric Power Plant using different type nanofluids

Abstract

Energy production in line with demand rapidly increases. Fossil-fuel systems in use today pose a great threat to the future of the world and in this sense, the interest to the renewable energy sources such as hydroelectric energy systems is increasing. In this study, the heating problem of the turbine bearings one of the parts of the hydroelectric energy systems was evaluated, various analyzes were performed with the Computational Fluid Dynamics (CFD) approach to eliminate this problem and the results obtained were shared. Initial analyses were performed and evaluated for Mobil DTE 68 oil, which was commonly used as a refrigerant in journal bearings. Then, Al2O3 nanoparticles at concentrations of 3%, 7% and 10% were then added to the refrigerant oil and necessary analyses were performed for these three conditions. Finally, similar analyses were performed in the 3%, 7% and 10% concentration for SiO2. When the obtained temperature changes were examined accordingly, it was obtained that the increase in the concentration of nanoparticles exhibited a characteristic that was inversely proportional to the surface temperature. With the addition of nanoparticles, surface temperatures have been observed to decrease from 80 °C’ to 68 °C’, but the effect on sharp corners is quite low. In this sense, it has been obtained that nanoparticles can significantly increase the thermal characteristics of Mobil DTE 68 oil, and it has been concluded that nanofluids may be an alternative solution for the overheating problem that occurs in turbine bearings.