Abstract:
Energy piles—A fairly new renewable energy concept—Use a ground heat exchanger
(GHE) in the foundation piles to supply heating and cooling loads to the supported building.
Applying phase change materials (PCMs) to piles can help in maintaining a stable temperature
within the piles and can then influence the axial load acting on the piles. In this study, two kinds
of carbon-based composite PCMs (expanded graphite-based PCM and graphite nanoplatelet-based
PCM) were prepared by vacuum impregnation for potential application in energy piles. Thereafter,
a systematic study was performed and different characterization tests were carried out on two
composite PCMs. The composite PCMs retained up to 93.1% of paraffin and were chemically
compatible, thermally stable and reliable. The latent heat of the composite PCM was up to 152.8 J/g
while the compressive strength of cement paste containing 10 wt % GNP-PCM was found to be
37 MPa. Hence, the developed composite PCM has potential for thermal energy storage applications.