Microencapsulated n-eicosane PCM suspensions: Thermophysical properties measurement and modeling

This research aims to present the preparation, characterization and thermophysical properties of water-based microencapsulated n-eicosane PCM suspensions for thermal energy storage. n-eicosane PCMs are coated with urea-formaldehyde polymer shell. The microcapsules have been characterized by Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) analyses. The differential scanning calorimetry (DSC) is also performed for measurement of the latent heat value, melting and freezing temperatures, and specific heat of MEPCMs. Then, the thermophysical characteristics of the MEPCM suspension including the thermal conductivity km and viscosity µm have been measured at different particle concentration (2, 5 and 10 wt%) and different temperatures from 25 to 50 °C. New correlations are developed to predict the thermophysical characteristics of MEPCM suspensions. Furthermore, the application performance of artificial neural network for predicting of km and µm is evaluated, and it is found that a neural network with the optimum structure of 2-4-4-2 provides a very accurate prediction of the experimental results.