MoS2-based nanofluid using pulsed laser ablation in liquid for concentrating solar power plant: Thermophysical study

Abstract

Concentrating solar power plants equipped with parabolic trough collectors (PTC), widely installed globally, require heat transfer enhancements in their hydraulic systems. This paper explores replacing conventional heat transfer fluids with 2D-MoS2/EG nanofluids, synthesized using the pulsed laser ablation in liquid (PLAL) method. Due to the layer-dependent physical properties of MoS2 nanosheets, tunability of PLAL in synthesizing uniform MoS2 monolayer nanosheets in EG with enhanced thermal conductivity and stability for solar PTC is essential and it is not studied thoroughly yet. Thus, this study aims to provide insights into the influence of varying laser parameters on the optical, structural, and thermal properties of MoS2-EG nanofluids and their thermal-hydrodynamical performance in solar PTC. Results show that longer ablation time, especially at higher laser energies, reduces the bandgap, thereby effectively increasing nanosheet formation. This is confirmed by phonon modes indicative of monolayer nanosheets that were outcomed from RAMAN spectroscopy. Zetasizer analysis shows that increasing the laser wavelength from 532 nm to 1064 nm reduces nanoparticle average size from 88.6 nm to 55 nm. Conversely, higher laser energy increases particle size. The optimized nanofluid improved thermal conductivity by 12.5 % at 25 °C and 13.5 % at 75 °C, maintaining a 7 % enhancement after 30 days. Analytical evaluations of solar PTC under single and counter swirl flows (SSF and CSF) show that CSF configurations with a lower twist ratio (0.4) outperform SSF, improving performance by 67 %. Furthermore, introducing optimized nanofluid by PLAL enhances performance by an 6 %. These findings underscore the potential of synthesizing MoS₂/EG nanofluids with higher thermal conductivity and stability via PLAL for enhancing CSP thermal systems.