Effect of Tube Bundle Arrangement on the Performance of PCM Heat Storage Units

The results of a comprehensive study on the charging and discharging of latent heat storage systems (LHSS) are presented. Multi-tube shell-and-tube units with variable layouts of tube bundles are examined. Two tube arrangements—in-line and staggered—are tested. A variable number of tubes and different tube positions in a bundle are investigated. Moreover, two pitch ratios are studied. Three commercially available substances are used as phase change materials (PCM). The results show that increasing the number of tubes reduces both the charging and discharging times. It is found that for a bundle of seven tubes with a pitch ratio s/d = 4.5, the in-line tube arrangement results in a shorter charging time, but the discharging time is shorter for a staggered tube arrangement.