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The present research aims to achieve a shape-stable, and leakage-proof material for thermal energy storage (TES). The leakage analysis of 20 wt.% SiO2@Cu PCM shows 0.05%, as a result, more testing is conducted to assess its morphology, structure, and thermal properties. TGA and DSC studies demonstrated that the latent heat and thermal degradation rate (TDR) has been delayed, with a significant decrease in latent heat of roughly 8.7% compared to pure paraffin. Laser Flash Method (LFA) results revealed that the thermal conductivity (TC) of the PCM composite significantly increased 4.84 times than the paraffin. [ABSTRACT FROM AUTHOR]

Disodium phosphate dodecahydrate was hybrid with n-octadecane as the phase change material (PCM) by reversed-phase emulsification. The cellulose sponge obtained based on cellulose nanocrystals was used as the support material to fabricate a shape-stable composite phase change material (CPCM) through impregnation. It was laminated with cotton fabric to obtain a sandwich structure thermal insulation fabric. An infrared spectrometer, scanning electron microscope, differential thermal scanning calorimeter, and other equipment were used to characterize the morphology, chemical groups, and latent heat properties of CPCMs and thermal insulation fabrics. The results displayed that the cellulose sponge had a porosity of 99.03%, a density of 0.012 g/cm3, and could withstand 1900 times its weight. When the mass proportion of PCM in the composite system was 67.5%, its latent heat energy was 84.44 J/g, which also revealed optimal shape stability. Compared to the original fabric, the thermal insulation efficiency of the sandwich structured fabric was increased by 17.7%∼18.2%, and the photothermal conversion rate reached 25.88%, with good application performance. [ABSTRACT FROM AUTHOR]

The low ability of phase change material (PCM) to transfer thermal energy has created a serious challenge for the development of latent heat storage (LHTES) units. Embedding foam with high thermal conductivity material like copper has attracted significant attention. Besides, high porosity, lightweight, and easy usage are other important benefits of copper. However, its higher cost and decreasing effective volume of PCM led to the creation of amendments in the foam design. Employment of the foam in the form of fin or foam fin has emerged as an alternative method to benefit from the advantages of porous material and overcome its defects. In this study, various LHTES units with different numbers of foam fins have been simulated numerically and compared with pure PCM and fully foam PCM enclosures. Two practical boundary conditions including constant temperature and constant heat flux were examined for the designed systems. The obtained results demonstrated that foam fins have a remarkable effect on the thermal performance enhancement of LHTES under constant temperature boundary condition. For LHTES with six foam fins, 42% and 30% reductions in melting time were achieved for both types of boundary conditions including constant temperature and heat flux, respectively. At the beginning of charging process, a significant enhancement of input heat rate was proved for LHTES with 6 foam fins and fully foam up to 112% and 155%, respectively. In addition, the foam fins method provided some free volume of PCM to permit the falling out of natural convection of molten PCM. [ABSTRACT FROM AUTHOR]