Study on phase change temperature distributions of composite PCMs in thermal energy storage systems

✍ Scribed by Jianfeng Wang; Guangming Chen; Fei Zheng

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 110 KB
• Volume: 23
• Category: Article
• ISSN: 0363-907X
• DOI: 10.1002/(sici)1099-114x(19990325)23:4<277::aid-er475>3.0.co;2-q

✦ Synopsis

A one-dimensional (1D) physical model is developed for latent heat thermal energy storage (TES) systems using composite phase change materials (PCMs) with different phase change temperature (PCT) distributions. By theoretical investigation under the assumption of neglecting the sensible heat, the optimum linear PCT distributions which are corresponding to minimum phase change time are derived. To verify the theoretical results of the optimum linear PCT distributions, the finite difference method is adopted to simulate the cyclical freezing and melting processes of composite PCMs. The numerical results in which the sensible heat is taken into account show that: (1) the optimum linear PCT distributions obtained from the theoretical analyses seem to be the optimum ones of composite PCMs in practical latent heat TES systems; (2) the phase change time of composite PCMs with the optimum linear PCT distributions used in practical latent heat TES systems can be decreased by as much as 25-40% by properly selecting the segmented numbers of composite PCMs as compared with that of PCMs of a single PCT.