Performance assessment of parabolic dish and parabolic trough solar thermal power plant using nanofluids and molten salts

Abstract

Summary The present study has been conducted using nanofluids and molten salts for energy and exergy analyses of two types of solar collectors incorporated with the steam power plant. Parabolic dish (PD) and parabolic trough (PT) solar collectors are used to harness solar energy using four different solar absorption fluids. The absorption fluids used are aluminum oxide (Al2O3) and ferric oxide (Fe2O3)-based nanofluids and LiCl-RbCl and NaNO3-KNO3 molten salts. Parametric study is carried out to observe the effects of solar irradiation and ambient temperature on the parameters such as outlet temperature of the solar collector, heat rate produced, net power produced, energy efficiency, and exergy efficiency of the solar thermal power plant. The results obtained show that the outlet temperature of PD solar collector is higher in comparison to PT solar collector under identical operating conditions. The outlet temperature of PD and PT solar collectors is noticed to increase 480.9 to 689.7 K and 468.9 to 624.7 K, respectively, with an increase in solar irradiation from 400 to 1000 W/m2. The overall exergy efficiency of PD-driven and PT-driven solar thermal power plant varies between 20.33 to 23.25% and 19.29 to 23.09%, respectively, with rise in ambient temperature 275 to 320 K. It is observed that the nanofluids have higher energetic and exergetic efficiencies in comparison to molten salts for the both operating parameters. The overall performance of PD solar collector is observed to be higher upon using nanofluids as the solar absorbers. Copyright © 2015 John Wiley & Sons, Ltd.