Experimental assessment of using Phase Change Lightweight Aggregates to enhance the thermal storage of geo-energy structures
Omar Elkezza, Mostafa Mohamed
Abstract
Geo-energy structures (GES) are mainly structural foundations that are used as heat exchangers to extract or dissipate heat from/to the ground, and they are progressively being adopted for providing more sustainable energy strategies in new buildings. Despite the fact that over one-third of a century has passed since the first installation of geo-energy structures in northern Europe, enhancing the thermal energy storage of those structures has not been thoroughly studied. This paper aimed to increase the thermal energy-storage of geo energy structures by incorporating phase change material–impregnated light-weight aggregates (PCM LWA'S) at the soil-structure interface. The results showed that the inclusion of 35 % PCM LWA's at the GES/soil interface extensively increased the temperature difference (inlet-outlet) for cooling and heating. It is also illustrated that the effect of PCM inclusion to enhance the thermal performance is more significant during the heating mode (PCM is cooled down) than during the cooling mode (PCM is heated up). Furthermore, the findings indicated that the use of PCM LWA's has reduced the thermal deformation of GES and has a positive impact on soil temperature and interference radius.