Performance analysis of solar thermal storage systems with packed bed utilizing form-stable phase change materials and heat pump integration.

This article focuses on the development and numerical analysis of a solar thermal energy storage system using a phase change material (PCM) packed bed coupled with a heat pump. The study evaluates the thermal storage and heat extraction performance under varying solar irradiation intensities, opening times, heat collection areas, PCM compositions (paraffin content and graphene nanoparticle addition), and packed bed porosities. Results indicate that higher solar irradiance and optimal operation times (9:00 a.m. or 11:00 a.m.) enhance storage efficiency, while increased paraffin content prolongs phase change duration and nanoparticle addition slightly reduces it. Lower porosity beds yield more uniform temperature distribution but higher pressure drops, and coupling with a heat pump demonstrates adaptable heat extraction rates, maintaining stable outlet temperatures over varying durations. These findings contribute to optimizing solar thermal storage integrated with heat pumps for improved energy efficiency and stability in renewable energy applications.