Experimental Investigation of the thermophysical properties of a phase change dispersion for cooling purposes

Phase change dispersions have recently gained interest in isothermal cooling applications. So far, almost all of the investigated phase change dispersions consist of paraffins as the phase change materials. Pure paraffins are expensive and suffer from lower latent heats at higher temperatures (50-60°C). This paper presents a phase change dispersion with two fatty-acid esters as the phase change material, Crodatherm-53/Crodatherm-47 (50:50). The dispersion has a melting temperature of 50°C and is foreseen in high-voltage direct current component cooling. The phase change dispersion was stabilised with emulsifiers to prevent phase separation and nucleation agents were added to supress supercooling. From thermal history calculations, the supercooling of the dispersion was reduced by 10 K with the addition of the nucleation agent. A monomodal particle size distribution was achieved. The viscosity of the dispersion at different temperatures and mass fractions of phase change material was also assessed. From DSC analysis, an apparent specific heat capacity of 8.5 kJ kg⁻¹ was measured for the phase change dispersion. This value is double the apparent specific heat capacity of water within the desired melting range (47.5-50.0°C). This paper presents further experimental data, formulation details and thermophysical and rheological properties of fatty acid esters as phase change materials in phase change dispersions.