The preparation and performance study on composite phase change materials of lauric acid-palmitic acid-tetradecyl alcohol/expanded perlite for thermal energy storage

摘要

In order to obtain phase change materials (PCMs) suitable for building energy conservation, ternary organic phase change materials were studied. According to the second law of thermodynamics and the theory of phase equilibrium, the phase change temperature and latent heat value of the ternary mixture with different proportions was calculated. The results show that the phase change temperature of lauric acid-palmitic acid-tetradecyl alcohol mixture with a mass ratio of 46:5:49 was calculated to be 25.1 °C, the latent heat value is 186 J/g, which was well consistent with the measured 24.8 °C and 165 J/g, and is in the desired temperature range of 25-30 °C for building phase change materials. Furthermore, a new material of lauric acid-palmitic acid-tetradecyl alcohol/expanded perlite was prepared by using a dry expanded perlite (EP) with a particle size of 0.9-2.5 mm as the adsorption carrier, and the optimum proportion of the lauric acid-palmitic acid-tetradecyl alcohol mixture was uniformly adsorbed into the EP by prevailing pressure adsorption method. Lastly, the effects of adsorption temperature and adsorption time on the retention rate were studied.