Latent and sensible energy storage enhancement of nano-nitrate molten salt

Molten salts have limited thermo-physical properties (such as specific heat capacity) which discourage their wide applications. Therefore, nanoparticles are dispersed in molten salt to improve the storage energy density. Thermophysical properties of CuO-nanosalt are compared with the nitrate binary solar salt. The effect of two different preparation methods of nanosalt samples have been studied and compared for the first time in one paper. Same weight concentration of nanoparticles in both methods of (1 wt.%) is conducted. The maximum increment in specific heat capacity was observed using the one step method by 21.24% in solid phase and 3.7% in liquid phase, respectively. Additionally, the sensible storage energy is improved in the case of nanosalt in comparison to nitrate salt by 9.27% in one step method. Moreover, the latent heat of 1 wt.% CuO-nanosalt (in one step method) increased by 67% in comparison to the nitrate binary salt without any additives while (in two step method) was 14.5%. This indicated the large effect of preparation methods of the nanosalt samples on different enhancements either in sensible heat or in latent heat. Samples are analysed using TEM which it showed an agglomerations of CuO nanoparticles prepared by the novel one step method.