A novel attempt to enhance the heat transfer rate of thermal energy storage using multitemperature phase change materials through experimental and numerical modelling

• Published in: Applied thermal engineering 2023-06, Vol.227, p.120457, Article 120457
• Main Authors: Nagappan, Beemkumar, Devarajan, Yuvarajan, Kariappan, Elangovan, Raja, T., Thulasiram, Ramachandran
• Format: Article
• Language: English
• Subjects: Clean energy; Energy research; Green energy; Renewable power; Sustainable energy
• ISSN: 1359-4311
• DOI: 10.1016/j.applthermaleng.2023.120457

•Multi-temperature PCM based thermal energy storage system is proposed.•Magnesium chloride hexahydrate, magnesium nitrate hexahydrate and paraffin wax are employed as PCM.•Numerical model analysis on the solid–liquid interface in PCM capsule is performed.•Charging and discharging characteristics of multiple PCM were analyzed.•Numerical model analysis on the solid–liquid interface in PCM capsule is performed. This work aims to develop the numerical model for the three-stage phase transition of multi-level phase change materials (PCMs) and present the comparative performance analysis between single PCM and multi-temperature PCM thermal energy storage (TES) systems. The performance of the thermal energy storage system was conducted by the implementation of multiple phase change materials (PCMs) which are arranged following the temperature profile of the heat transfer fluid. The proposed TES system has two models; the first is fully packed with single PCM – Erythritol TES, and the second is packed with multi-temperature PCMs, namely acetanilide in the first half of the tank and 1-Naphthol in the second half of the tank. The experiments are conducted to validate the numerical model values and observed that the results are in close agreement with each other and the percentage variation is within 3–5%. The results show that using multi-temperature PCMs provides better performance than single-PCM systems. Based on the results, the performance of the TES system can be enhanced with multi-level PCMs rather than choosing high-conductivity materials in the system, which lead to considerable potential in saving energy loss and an economical way of designing the efficient TES system.