Chapter 12 - Utilization of nanofluids (mono and hybrid) in parabolic trough solar collector: a comparative analysis

Abstract

The application of hybrid nanofluids plays a crucial role for heat transfer enhancement in solar collectors. The utilization of conventional heat transfer fluids (water, ethylene glycol/water, thermal oils) has limitations due to their low thermal properties. Therefore, advanced heat transfer fluids such as mono and hybrid nanofluids get extraordinary attraction due to their enhanced thermophysical properties, mainly thermal conductivity, that lead to better heat transfer characteristics. The present chapter deals with the utilization of Syltherm-800-based mono and hybrid nanofluids in the parabolic trough collector (PTC). Mono nanofluids (TiO2, CuO, MWCNT, and CeO2) and hybrid nanofluids (MWCNTs-TiO2, MWCNTs-CuO, and MWCNTs-CeO2) are investigated and compared to evaluate the thermal enhancement performance of PTC absorber tubes. Thermal efficiency, exergetic efficiency, heat transfer coefficient, Nusselt number, pressure drop, and pumping power are the parameters investigated at different inlet temperatures. In addition, performance evaluation criteria examine the entire thermal enhancement variations in friction factor and Nusselt number. Thermodynamic modeling of the system is conducted in an engineering equation solver.