Heat transfer enhancement of neopentyl glycol using compressed expanded natural graphite for thermal energy storage

Neopentyl glycol (NPG) was saturated into the compressed expanded natural graphite (CENG) matrices with different densities in an attempt to increase the thermal performance of NPG for latent heat thermal energy storage (LHTES) application. NPG uniformly disperses in the porous network of the expanded graphite. Measured results indicated that thermal conductivities of the composites can be enhanced 11–88 times as compared with that of the pure NPG. The latent heat of the NPG/CENG composites increased with the increasing mass ratio of the NPG in the composites. Compared with the pure NPG, the deformation of the composites due to phase change has been greatly reduced. After phase transition, thermal conductivity of the composites decreased slightly. The trends concluded from the finite element simulation are coincident with the trends from the thermal imager.

► The CENG can enhance the thermal conductivities of the CENG/NPG composites. ► FEM and thermal imager are used to investigate the anisotropy of heat transfer. ► After phase transition, the thermal conductivity of composite has decreased slightly. ► Thermal imager results are coincident with FEM results. ► NPG is a kind of solid–solid phase change materials.