Influence of rheological behavior of molten sodium sulfate on adherent heterogeneous surface on performance of high-temperature thermochemical energy storage

Abstract

Molecular dynamics simulations were carried out to investigate the influence of the rheological behavior of molten sodium sulfate on the adherent heterogeneous surface on the performance of high-temperature thermochemical energy storage. It was found that the molten salts occurred to migrate on a nanoscale adherent heterogeneous surface due to the energy gradient of the heterogeneous surface. Molten salts underwent three spreading stages during the entire migration process. Poor wettability of the molten salt on the CaO surface came out in the climb spreading stage, and good wettability came out in the fall spreading stage. More importantly, the motion of molten salt caused an additional enhancement effect of potential energy at the interface compared to the pure CaO surface. The enhancement mechanism was the kinetic energy caused a more violent collision of ions between the molten salt and the solid surface, which lead to a local overheat at the interface to promote the ionization of the surface. The structural analysis illustrated that the calcium oxide ions of the heterogeneous surface appear stronger fluidization compared with the calcium oxide ions of the pure calcium oxide surface. The enhancement effect worked on the CaO based adsorbent rather than the inert solid supports.