Experimental study on sodium acetate trihydrate/glycerol deep eutectic solvent nanofluids for thermal energy storage

With the development of electronic machinery, the traditional heat exchange working fluid can no longer be used in some extreme working environments. As a new type of fluid, deep eutectic solvent has the advantages of promising thermal stability, low cost and non-toxicity through the hydrogen bond associ-ation of hydrogen bond acceptor and hydrogen bond donor, and is also coined to be an efficient heat transfer working fluid. In this work, three kinds of nanofluids filled with TiO2, Al2O3 and Fe2O3 nanopar-ticles were prepared with glycerol/sodium acetate trihydrate deep eutectic solvent as the base solution, and the mechanism of thermal conductivity change of nanofluids were discussed from atomic and micro-scopic levels. The experimental results showed that the prepared glycerol/ sodium acetate trihydrate 2:1 deep eutectic solvent system reduced the viscosity by 58.03% compared with glycerol, and increased the thermal conductivity by 17.2% compared with glycerol at 25 celcius. The effects of nanoparticles on thermal conductivity and specific heat capacity were also investigated. Compared with deep eutectic solvent, the thermal conductivity was improved after adding Fe2O3 nanoparticles; it is worth noting that the specific heat capacity of nanofluids was more than doubled after adding nanoparticles.(c) 2022 Elsevier B.V. All rights reserved.

Automated summary

With the development of electronic machinery, the traditional heat exchange working fluid is inadequate in extreme working environments. Deep eutectic solvent, as a new type of fluid, demonstrates promising thermal stability, low cost, and non-toxicity through hydrogen bond association, making it an efficient heat transfer working fluid. This study utilized glycerol/sodium acetate trihydrate deep eutectic solvent as a base solution, prepared nanofluids filled with TiO2, Al2O3, and Fe2O3 nanoparticles, and discussed the mechanism of thermal conductivity change at the atomic and microscopic levels. Experimental results showed that the prepared deep eutectic solvent system reduced viscosity by 58.03% and increased thermal conductivity by 17.2% compared to glycerol at 25 degrees Celsius. Furthermore, the impact of nanoparticles on thermal conductivity and specific heat capacity was investigated, with thermal conductivity being improved by the addition of Fe2O3 nanoparticles and the specific heat capacity of nanofluids more than doubling after nanoparticle incorporation.