Preparation and thermal properties of nano-SiC modified paraffin phase change emulsion
In order to prepare a pumpable PCME with high stability,low subcooling and high thermal conductiv-ity,a modified PCME was prepared by adding different mass fractions of nano-SiC to paraffin(RT55)emulsion(SiC/PCME).The sample of SiC/PCME was prepared by ultrasonic method.The particle size distribution,phase change behaviors,thermal conductivity,thermal response rate and rheological properties of SiC/PCME were investigated.The results showed that the volume average particle size of SiC/PCME with 0.09 wt％SiC was 480 nm,and there was slight change in the particle size distribution before and after 20 days and 120 ther-mal cycles.The latent heat value of 0.09 wt％SiC/PCME measured by DSC was 39.0 J/g,and the subcooling degree was only 0.03 ℃,which was 11.8 ℃ lower than that of unmodified PCME.The subcooling degree of 0.09 wt％SiC/PCME was hardly changed after 120 cycles,which had good cycling thermal stability.The thermal conductivity of SiC/PCME was reached 4.247 W/m·K at 55 ℃.The thermal conductivity of the PCME and thermal response speed were improved by the addition of SiC nanoparticles.The lowest viscosity of SiC/PCME was 3 mPa·s at the shear speed of 100/s.
phase change material emulsionsstabilitythermal propertiesrheological properties
NETL
NSTL
万方数据
