Numerical investigation of the impact of toothed fins on the heat transfer performance of a shell-and-tube exchanger during phase change material melting process

Abstract

The poor thermal conductivity of phase transition materials hampers the development of latent heat energy storage devices. There is much scholarly interest in enhancing heat transmission in these materials. Using a finned shell-and-tube exchanger is a traditional strategy for improving the effectiveness of latent thermal energy storage devices. However, the storage systems' actual working volume decreases when many fins are added. Numerous studies have shown that toothed fins are more efficient in transferring heat than regular fins. As a result, it is anticipated that toothed fin latent heat energy storage systems will produce better thermal effects. Unfortunately, the impact of toothed fins on the melting of phase transition materials has only been briefly discussed in published literature. To close this important knowledge gap, this paper thoroughly studies two regularly used fins, namely the annular fin and longitudinal fin with toothed apertures. The impact of different toothed-opening volumes and tooth spacing on the melting process of phase transition materials are examined using numerical simulations. The results show that toothed fins have a 20% lower fin volume than traditional circular and longitudinal fins, which has a marginally less positive impact on phase change material melting times of 1.09% and 0.98%, respectively. The recommended toothed-opening volume and tooth count for the annular fin are 10%–20% and 16 teeth, respectively, whereas the recommended toothed-opening volume and tooth spacing for the longitudinal fin are 10%–20% and 1 mm, respectively. Additionally, the tooth spacing affects heat transfer, in one investigation, decreasing the tooth spacing by 2.5 and 2 times led to reductions in the melting periods of phase change materials of 60 and 70 s, respectively.