Performance of a latent thermal energy storage tank fitted with carbon-fiber cloths to expand the heat transfer area

Carbon-fiber cloths were installed in a latent heat thermal energy storage (LHTES) tank to expand the heat transfer area, and the characteristics of the energy charge and discharge processes were compared with the results for carbon-fiber brushes previously reported. In the charge process, carbon-fiber cloths with a volume of 0.27% of the tank volume exhibited better thermal performance than carbon-fiber brushes with a volume of 1.3%. In the discharge process, their thermal performances were the same. The thermal performance of the cloths was accordingly superior to the brushes. When the discharge characteristics were evaluated in terms of the overall fin efficiency, that of carbon-fiber cloths under the present conditions was twice as high as that without carbon fibers. An increase in volume fraction of carbon fibers resulted in higher efficiency, which reached 0.9 only at 1 vol.% of carbon fibers.