Fundamental Study on Latent Cold Heat Energy Storage by Means of Oil Droplets at Low Freezing Point. Cold Heat Energy Release Characteristics of Direct-Contact Heat Exchange between Solidified Oil Droplets and Hot Air.

Abstract

This paper deals with the cold latent heat energy release characteristics of direct-contact heat exchange between solidified oil droplets[tetradecane, CH3(CH2)12CH3, melting point of 5.8°C]and hot air. The hot air was injected into a solidified oil droplets-water mixture layer from the distributor with a number of small circular nozzles. The solidified oil droplets-water mixture layer was fluidized by air bubbles ascending in the layer, and the air bubbles were cooled as they passed through the layer, by direct-contact heat exchange. The present paper describes the characteristics of temperature and humidity of the outlet air from the layer, and time history of the cold heat energy release. The experiments were performed with reference to several experimental parameters, i.e., air flow rate, air temperature and humidity, and the proportion of solidified oil droplets to water in the mixture layer. Finally, some correlation equations for the outlet air temperature and humidity, and the completion time of cold latent heat energy release were derived in terms of various nondimensional parameters.