Experimental investigation of thermal characteristics of phase change material in finned heat exchangers

• Published in: Journal of energy storage 2023-11, Vol.71, p.108162, Article 108162
• Main Authors: Dhaidan, Nabeel S., Hassan, Ali F., Rasheed Al-Gaheeshi, Asseel M., Al-Mousawi, Fadhel Noraldeen, Homod, Raad Z.
• Format: Article
• Language: English
• Subjects: Fins; Heat exchangers; Melting; PCM; Perforation; Thermal performance
• ISSN: 2352-152X; 2352-1538
• DOI: 10.1016/j.est.2023.108162

A significant challenge to the widespread use of practical latent heat energy storage systems based on phase change materials is the inherent low thermal conductivity of these materials. Inserting fins is considered one of the effective methods of heat transfer enhancement. In the present paper, an experimental investigation of the melting process of PCM in finned and unfinned heat exchangers is conducted. The experimental setup was constructed, and the measurement system was used to monitor the transient progress of the melting process. The heat exchanger comprises annular horizontal concentric double pipes, where the inner tube is heated by flowing water as heat transfer fluid (HTF), and the outer shell is thermally insulated. Four configurations of fins of the same fin/PCM volume ratio are attached to the inner tube. These configurations are longitudinal fin (LF), circular fin (CF), longitudinal perforated fin (LPF), and circular perforated fin (CPF). The effect of inlet HTF temperatures of 60, 70, and 80 °C is tested. The experimental findings indicate that the thermal performance of finned heat exchangers exceeds that of unfinned heat exchangers. Also, the perforated finned heat exchangers showed a higher thermal feature than the unperforated ones. In addition, the CPF achieved the lowest melting time and the highest melting rate, followed by LPF, CF, and LF. The maximum reductions of melting time are 71.1 %, 70.6 %, and 70.2 % due to using CPF HE instead of UF HE for inlet HTF temperatures of 60, 70, and 80 °C, respectively. •The melting characteristics of PCM in finned heat exchangers are evaluated.•The perforated and unperforated longitudinal and circular fins are involved.•The insertion of fins enhances the melting characteristics of finned heat exchangers.•The performance of the perforated fins is higher than that of the unperforated fins.•The temperature of heat transfer fluid significantly affects the melting process.