Enhancing the thermal response of latent heat storage systems

Latent heat storage systems especially those employing organic materials have been reported to exhibit a rather slow thermal response. This is mainly due to the relatively low thermal conductivities of organic latent heat materials. This paper reports experiments carried out to investigate methods of enhancing the thermal response of paraffin wax heat storage tubes by incorporation of aluminium thermal conductivity promoters of various designs into the body of the wax. Heating and cooling runs were carried out and phase change times determined. It was found that the phase change time reduced significantly by orders of up to 2·2 in energy storage (heating) and 4·2 in energy recovery (cooling). Internal fins performed much better than the star matrices and expanded aluminium performed better than promoters made from aluminium sheet metal in both storage and recovery of heat. © 1997 John Wiley & Sons, Ltd.