The authors outline a method of enhancing the thermal properties of a paraffin phase change material through the addition of herringbone-style graphite nanofibers (HGNFs). It was found that the solid-phase thermal conductivity increased exponentially with the presence of HGNFs; however, a significant increase in the liquid-phase thermal conductivity was not observed until the concentration of HGNFs in the composite PCM reached a point above the percolation threshold. The volumetric heat ...
The fatty acid stearic acid has been widely studied for its use in thermal energy storage applications as a phase change material (PCM). Stearic acid shows promise for this application because of its high volumetric storage density and its favorable thermal properties; however, two properties of stearic acid limit its use as a PCM: its low thermal conductivity and its propensity to leak liquid during the phase change process. This ...
Through the addition of expanded graphite (EG) to polyethylene glycol, the authors were able to enhance the thermal conductivity of the phase change material (PCM). The transient plane source (TPS) technique was used to measure the thermal conductivity of the PCM. The amount of EG affected thermal conductivity, while amount of polyethylene glycol affected latent heat. Through the use of EG, the thermal conductivity was raised fourfold.....
Through the addition of copper oxide nanoparticles to cyclohexane in varying concentrations, a series of nano-enhanced phase change materials (NePCM) were prepared. The transient plane source (TPS) technique was used to characterize the NePCM at multiple temperatures. It was determined experimentally that increasing concentrations of nanoparticles in the liquid phase resulted in increasing thermal conductivity, but increasing nanoparticle concentration in the solid phase didn't have the same effect.Unidirectional freezing ...
Through the addition of different amounts of thermally conducting B-Aluminum nitride powder to polyethylene glycol and silica gel a form-stable phase change material (PCM) is prepared. Using the Thermal Constants Analyzer, the researchers were able to measure the thermal conductivity of the PCMs. Increasing amounts of B-Aluminum nitride powder results in increasing thermal conductivity, but a decrease in the value of the latent heat. Melting temperatures were unaffected by the ...
