Thermal performance and optimization of a casing pipe solar energy storage floor with phase change material

Abstract

For PCM utilization in building component, energy storage structure is expected to improve the ability to extract heat from heat source and dissipate heat to the room at the same time. This paper presents a ring-shaped energy storage structure with combination of an outer casing pipe and an inner coil pipe in heating terminal. To better understand thermal performance and integration strategy of the terminal, effects of thermal parameters of PCM and structural parameters of casing pipe are analysed by numerical model. Root mean square deviation (RMSD) are 0.3% and 2.1% with experiments conducted to validate numerical model. Compared with conventional PCM and traditional heating terminal, casing tube PCM heating terminal have highest stability coefficient index at 0.983, which shows its thermal constancy and comfort level. Results show both thermal conductivity and heat of fusion of PCM have lifting limit at 0.2 W/m2·K and 350 J/g for enhancing the heating terminal thermal performance. PCM melting temperature have matching point at 293 K for high concrete layer surface average temperature and low temperature amplitude. Changing the ratio of casing and coil pipe diameter from 1.5 to 2 could reduce 12.3 K temperature fluctuation on floor surface. The above research provides a heating terminal which can simultaneously enhance heat absorption from heat source and emission to indoor room, while a basic reference for the terminal design and selection is investigated.