REVIEW ON SUSTAINABLE THERMAL-ENERGY STORAGE TECHNOLOGIES, PART-I - HEAT-STORAGE MATERIALS AND TECHNIQUES

This paper reviews the development of available thermal energy storage (TES) technologies and their individual pros and cons for space and w ater heating applications. Traditionally, available heat has been stor ed in the form of sensible heat (typically by raising the temperature of water, rocks, etc.) for later use. In most of the low temperature a pplications, water is being used as a storage medium. Latent heat stor age on the other hand, is a young and developing technology which has found considerable interest in recent times due to its operational adv antages of smaller temperature swing, smaller size and lower weight pe r unit of storage capacity. it has been demonstrated that, for the dev elopment of a latent heat thermal energy storage system, the choice of the phase change material (PCM) plays an important role in addition t o heat transfer mechanisms in the PCM. Attempts have also been made to utilize technical grade phase change materials as storage media and e mbedded heat exchange tubes/heat pipes with extended surfaces in order to enhance the heat transfer rate to/from the PCM. (C) 1998 Elsevier Science Ltd. All rights reserved.