Akademik Veri Yönetim Sistemi
JOURNAL OF POLYTECHNIC-POLITEKNIK DERGISI, 2023 (ESCI)
Energy is one of the world's critical resources. For this reason, energy saving and efficiency is an important study subject. In order to save energy, there are theoretical and experimental studies in the literature due to the need for the improvement of heat transfer and the compactness of the heat exchangers, and the search for new fluids that will provide heat transfer improvement instead of the traditional fluids used in heat exchangers.In this study, the nanofluids obtained by changing the ratios of Al2O3 and SiO2 high nanoparticles volume fraction instead of low nanoparticles volume fraction and by changing the ratios of the base fluid ethylene glycol-water mixtures, where efficient results were obtained in providing heat transfer improvement, the thermal and hydraulic performance of a concentric, intertwined, parallel and counter flow in a tubular heat exchanger, using hot and cold fluids at different volumetric flows, was investigated numerically. Water on the hot fluid side, 0:100%, 40:60%, 60:40% and 100:0% on the cold fluid side, into different ratios of EG-water at 0%, 2%, 4%, 6% nanoparticles volume fractions and different Reynolds numbers (6000 - 8000 - 12000 - 16000 -20000) nanofluids obtained by adding Al2O3 and SiO2 nanoparticles were used. According to the results of numerical studies, when the fixed volumetric flow value of hot fluid water is 3 l/min, the constant volumetric flow value of nanofluids is 0.9 l/min and Reynolds number 20000, Al2O3-100:0% EG/water and SiO2-100:0% EG/water. The Nusselt number of nanofluids increased by 15.4% and 9.1%, respectively, compared to 0:100% EG/water. The results showed that the pressure drop in a counter flow tubular heat exchanger is high, as well as the heat exchanger performance is better than the parallel flow, the Nusselt number increases with the solid volume concentration contained in the nanofluid, and both the 0:100% ratio and the SiO2 of the Al2O3-100:0% EG/water nanofluid. SiO2-100:0% EG/water indicates that it is more effective in increasing the performance of the heat exchanger compared to nanofluid.