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ISSN Online: 2377-424X

ISBN Print: 978-1-56700-474-8

ISBN Online: 978-1-56700-473-1

International Heat Transfer Conference 16
August, 10-15, 2018, Beijing, China

A COMPARISON STUDY ON HEAT TRANSFER ENHANCEMENT OF PHASE CHANGE MATERIALS BY ADDING CARBON MATERIALS WITH DIFFERENT MICROSTRUCTURES

Get access (open in a dialog) DOI: 10.1615/IHTC16.hte.022479
pages 5459-5475

摘要

Decrease of the fossil fuels and increase in the energy demand has increased the mismatch between energy demand and supply. Excess energy stored in a suitable form has been able to bridge this energy demand/supply gap significantly. Thermal energy storage with the use of phase change materials (PCMs), which feature to high energy storage density and nearly isothermal operating characteristic, is an effective way to solve the problems of energy storage and conservation. Poor heat transfer performance is the common drawback for most potential PCMs due to the low thermal conductivity. Therefore, this study investigates the performance enhancement of palmitic and stearic acids eutectic mixture (PA-SA) with the additions of different microstructure and dimension carbon materials (carbon nanotubes, graphene nanoplatelets and expanded graphite) as heat transfer promoters. Composite PCMs filled with carbon materials were prepared at various loadings by melt blending method. The microstructure, thermal properties, thermal conductivity of the composite PCMs were measured. The heat transfer performance of the composite PCMs were investigated by the thermal energy storage/release test in a phase change unit. The results show that all the carbon materials can improve the thermal conductivity of PA-SA effectively, but it also weakens the natural convection of PA-SA in liquid state. The heat transfer performances results show that expended graphite with threedimensional network structure is more effective addition for enhancing the heat transfer of the PCMs compared with other carbon materials.