Performance analysis of high temperature thermal energy storage using magnesium based complex metal hydride: A comparative study of reactor configuration

• Published in: Journal of energy storage 2025-01, Vol.107, Article 114989
• Main Authors: Dubey, Sumeet Kumar, Kumar, K. Ravi, Tiwari, Vinay, Srivastva, Umish
• Format: Article
• Language: English
• Subjects: Complex metal alloy; Energy storage efficiency; Metal hydride; Thermochemical energy storage
• ISSN: 2352-152X
• DOI: 10.1016/j.est.2024.114989

Thermal energy storage using metal hydrides have the potential for storing high temperature thermal energy with minimal heat losses. Unit weight of NaMgH2F is used in the analysis for thermal energy storage in the temperature range of 773 K to 823 K. The energy sorption performance characteristics have been studied using NaMgH2F as energy storage media. Different initial temperatures of the metal hydride reactor, i.e., 773 K, 798 K, and 823 K, are considered for heat transfer and energy sorption analysis. Metal hydride reactors with two different heat transfer fluid flow configurations with the same heat transfer area have been studied to analyze the heat transfer within the reactor along with energy storage performance characteristics. Heat transfer fluid flow configuration 1 has only axial heat transfer fluid tubes, while a circumferential heat transfer fluid jacket is included in configuration 2 along with axial heat transfer fluid. Flow configuration 2 has shown better storage and heat transfer results. The energy storage efficiency at 773 K, 798 K, and 823 K initial reactor temperatures for configuration 1 are 93.2 %, 93.7 %, and 94.4 %, respectively, and 95.2 %, 95.8 %, and 96.4 %, respectively, for configuration 2. [Display omitted] •Numerical analyses of energy sorption in magnesium based complex metal hydride•The effect of initial reactor temperature and HTF flow arrangement is studied.•Energy storage and heat transfer improved with circumferential HTF flow arrangement.•A minimum and maximum energy storage efficiency of 93.2 % and 96.4 % is achieved.•System feasible for energy storage around 500 °C with >90 % storage efficiency