One of the goals engineers pursue in the energy production and recovery field is to design a heat exchanger that
can store a large amount of thermal energy in a shorter time. This work practically tests the performance attributes of a latent heat thermal energy storage system in a vertical shell-tube heat exchanger configuration.
Water flows in the tubes that are arranged as circular layers at certain radii in the shell, which is occupied by
organic paraffin phase change material (RT60). The experiments consider the effects of the tube area ratio, layer
radius ratio, number of tube layers, and distribution of the tubes (inline/staggered), besides incorporating semicircular tubes instead of complete circular ones. These experiments are conducted by employing heating water
(65 ◦C to 75 ◦C) during the charging process and cooling water (25 ◦C) during the discharging process. The key
findings from this work are that increasing the radius ratio from 1/3 to 2/3, employing semicircular tubes instead
of complete ones, increasing the area ratio from 2.4% to 4.3%, and distributing the same number of tubes in two
layers rather than one layer provide reductions in the charging time of 7.2%, 7.3%, 17.6%, and 11%, respectively. The corresponding augmentations in the charging/discharging effectiveness are 8.1%/2.6%, 7.4%/3.3%,
19.7%/5.7%, and 8%/4.5%, respectively. Moreover, by applying a staggered distribution of the tubes instead of
an inline one, the charging effectiveness is amplified by 5.3%. Finally, a set of experimental correlations is
developed to predict the charging effectiveness of the storage system. |
