Heat transfer enhancement of a cascaded thermal energy storage system with various encapsulation arrangements

• Main Authors: Nagappan Beemkumar, Alagu Karthikeyan, Devarajan Yuvarajan
• Format: Article
• Language: English
• Published: VINCA Institute of Nuclear Sciences 2019-01-01
• Series: Thermal Science
• Subjects: cascaded thermal energy storage system; multiple PCM; encapsulation materials
• Online Access: http://www.doiserbia.nb.rs/img/doi/0354-9836/2019/0354-98361700227N.pdf

Ever increasing energy demand ever encourage for new energy production and conservation. In the present work, the cascaded latent heat solar thermal energy storage system has been developed to deliver the heat at different temperature limits and its performance on the improvement of heat transfer characteristics are studied with the use of multiple phase change material (PCM) with various encapsulation arrangements. The storage system consists of three different PCM which have different melting temperatures such as D-mannitol, D-sorbitol, and paraffin wax. Each PCM is encapsulated in different materials of spherical balls like copper, aluminum, and brass. Permanent welding of fins, inside the encapsulated balls of type rectangular, annular and pin is done for enhanced heat transfer. This work investigates for the best combination of fins which may allow the highest heat transfer rate for the least cost. It has been concluded that the transfer of energy is the highest in the use of copper balls for encapsulation of PCM with the attachment of annular fin inside the balls. With respect to energy cost per kJ of heat transfer, the PCM encapsulated in aluminum balls with annular fins may be preferred. However, in all the combinations, to gain higher efficiency of the system proper arrangements of all system components very close to each other is essential to the provision of perfect insulated storage tanks and the components of the piping circuit.