The Thermal Response of Heat Storage System With Paraffin and Paraffin/Expanded Graphite Composite for Hot Water Supply

P. Zhang
Institute of Refrigeration and Cryogenics, Shanghai Jiao Tong University, China

L. Xia
Institute of Refrigeration and Cryogenics, Shanghai Jiao Tong University, China

R. Z. Wang
Institute of Refrigeration and Cryogenics, Shanghai Jiao Tong University, China

Ladda ner artikelhttp://dx.doi.org/10.3384/ecp11057756

Ingår i: World Renewable Energy Congress - Sweden; 8-13 May; 2011; Linköping; Sweden

Linköping Electronic Conference Proceedings 57:2, s. 756-763

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Publicerad: 2011-11-03

ISBN: 978-91-7393-070-3

ISSN: 1650-3686 (tryckt), 1650-3740 (online)


The low thermal conductivity of phase change material (PCM) leads to low heat storage/retrieval rates. The expanded graphite (EG) was used to enhance the thermal conductivity. EG/paraffin composite with the 7% mass fraction of EG was prepared as a good candidate for the latent thermal energy storage (LTES) system. A shell and tube LTES system built for room heating and hot water supply in a family was experimentally investigated. The paraffin and paraffin/EG composite were used as the heat storage material; respectively. The experimental results indicated: The utilization of EG/paraffin composite PCM greatly improved the heat storage/retrieval rates of the LTES system. The LTES system with paraffin/EG composite showed a 44% reduction in heat storage duration and a nearly 69% reduction in the retrieval duration; respectively; compared to those for the system using pure paraffin. The most outstanding advantage; for the LTES system filled with paraffin/EG composite; was that the outlet temperature of water can be maintained at a higher level for a longer term than that with paraffin. However; the LTES system filled with EG/paraffin composite did not show an obvious advantage in the step-by-step heat retrieval mode; compared with paraffin.


Latent thermal energy storage; Paraffin/expanded graphite composite; Heat storage/retrieval rate


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