Performance comparison of PTCs with nanoparticles in water and nanoparticle in thermal oil

Abstract

The use of nanoparticles to improve the thermal efficiency of PTCs has become a popular area of research. In this study, we present a comparative analysis of the effects of nanoparticles on the thermal performance of PTCs using water and thermal oil as heat transfer fluids. To obtain accurate temperature estimates, we developed a mathematical model that considers heat transfer in both axial and radial directions. The model includes a two-phase flow homogenous model for the liquid phase, as well as nanoparticle concentration, to achieve the best temperature estimation. We validated our model using experimental data and found that the maximum relative error was 2.3% for water and a lower error of 1.5% for thermal oil. Our analysis of thermal efficiency and exergetic efficiency showed that the addition of Al2O3 nanoparticles led to greater improvements in the thermal efficiency for water, even at the same range of nanoparticle concentration. Furthermore, our results demonstrated that exergetic efficiency was generally higher for water than for thermal oil. Overall, this study highlights the potential benefits of using nanoparticles to enhance the thermal efficiency of PTCs. Our findings could help guide the design and optimization of PTC systems in various applications.