Experimental study of myristic acid-xylitol eutectic PCM in a wing-structured solar air collector for medium-temperature thermal storage.

Conventional Phase Change Materials (PCMs) used in solar drying systems often exhibit limitations such as fixed melting temperatures and inadequate thermal matching for medium-temperature applications. To overcome this problem, a novel eutectic PCM composed of Myristic acid (MA) and Xylitol (XY) was developed and incorporated into a solar air collector equipped with an alternative wing-structured absorber plate. The XY composition varied from 10 to 30% in eutectic PCM. Three eutectic compositions (MA90/XY10, MA80/XY20, and MA70/XY30) were prepared and analyzed using DSC, FTIR, SEM, and XRD techniques to evaluate their thermal and structural characteristics. The performance of the system was experimentally examined under solar intensities of 700 and 1000 W/m², and mass flow rates of 0.002 and 0.003 kg/s, both with and without PCM. The experimental results showed that the MA80/XY20 composition achieved a suitable melting temperature of 63.5 °C and a latent heat of 176.8 J/g. The integration of eutectic PCM enhanced the thermal energy storage capacity up to 570.5 kJ, which is significantly higher than the system without PCM. Moreover, improvements in drying efficiency and moisture removal rate were observed. The study confirms that the developed eutectic PCM effectively improves thermal stability and overall performance of solar drying systems.