THERMAL-PROPERTIES OF ORGANIC LATENT COLD-STORAGE MATERIALS

The thermal properties of organic compounds intended to be applied as latent cold storage substances were investigated by methods of analysis according to Tammann, and by DTA and DSC. Findings were made concerning the melting and solidification behaviour, subcooling, specific melting enthalpies and specific heat capacities of paraffin mixtures, low and high-molecular glycols, ethylenediamine hydrates and formamide. Ethylenediamines and ethylene glycol, with high storage densities of 200-300 MJ.m-3, appear to bc promising cold storage substances if subcooling is reduced. Through the use of congruently melting low-molecular glycols and formamide, storage densities of about 170 MJ.m-3 are obtained. Paraffin mixtures and high-molecular glycols melt in wide ranges of temperatures and give values of about 100 MJ.m-3, which are not relevant to cold storage units.