An experimental investigation of cold storage in an encapsulated thermal storage tank

This paper experimentally investigates the thermal performance and the pressure drop of an encapsulated thermal storage tank during the charging process. A polyvinyl chloride (PVC) hollow cylinder is used as the thermal storage tank. The cylindrical capsules inside the thermal storage tank utilize water added with nucleation agents as the phase change material (PCM), and the coolant is the aqueous solution of ethylene glycol. A series of experiments were carried out to investigate the effects of the inlet coolant temperature and coolant flow rate on nucleation of capsules, heat transfer and pressure drop of the tank. The results indicate that cool energy can be fully stored ill the form of latent heat when the inlet coolant temperature is set below the temperature with 100% nucleation probability. The lower the inlet coolant temperature and the larger the coolant flow rate, the more efficient the storage tank. A correlation for the pressure drop of coolant during a charging process is also developed. (C) 2000 Elsevier Science Inc. All rights reserved.