Performance analysis of heat storage of direct-contact heat exchanger with phase-change material

This paper describes the improvement of the heat-storage performance of a direct-contact heat exchanger using the phase-change material (PCM) erythritol (melting point: 391 K) and a heat transfer oil (HTO). A vertical cylinder with 200-mm inner diameter and 1400-mm height was used as the heat-storage unit (HSU). A nozzle pointing vertically downwards was placed on the bottom of the HSU. We examined the effect of the height of the PCM in HSU on heat storage, using two characteristic parameters: temperature effectiveness and the rate of heat storage. According to the results, both of these parameters increase during the increase in latent heat storage with the height of PCM, due to the increase in the residence time with the height of PCM.