Exergy Analysis for the Evaluation of the Performance of Closed Thermal Energy Storage Systems

1988 ◽  
Vol 110 (4) ◽  
pp. 255-261 ◽  
Author(s):  
M. A. Rosen ◽  
F. C. Hooper ◽  
L. N. Barbaris
Keyword(s):  
Energy Storage ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Exergy Analysis ◽  
Storage Systems ◽  
Energy Storage Systems ◽  
General Acceptance ◽  
The Individual ◽  
Thermal Energy Storage Systems ◽  
Heat Transfers

The use of exergy analysis, rather than energy analysis, for the evaluation of the performance of thermal energy storage systems is discussed. The energy and exergy relationships for a simple closed tank storage with heat transfers by heat exchanger are obtained. A complete storing cycle, as well as the individual charging, storing, and discharging periods, are considered. A numerical example for a simple case is given. The work reported is preliminary to the task of developing simplified conventions for the evaluation and comparison of the performance of thermal storages using exergy analysis methods. The establishment of such simplified conventions appears to be a necessary prerequisite to general acceptance of these methods by the engineering community.

scholarly journals Nano-Enhanced Phase Change Materials in Latent Heat Thermal Energy Storage Systems: A Review

Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3821
Author(s):  
Kassianne Tofani ◽  
Saeed Tiari
Keyword(s):  
Energy Storage ◽  
Phase Change ◽  
Latent Heat ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Phase Change Materials ◽  
Storage Systems ◽  
Heat Pipes ◽  
Energy Storage Systems ◽  
Thermal Energy Storage Systems

Latent heat thermal energy storage systems (LHTES) are useful for solar energy storage and many other applications, but there is an issue with phase change materials (PCMs) having low thermal conductivity. This can be enhanced with fins, metal foam, heat pipes, multiple PCMs, and nanoparticles (NPs). This paper reviews nano-enhanced PCM (NePCM) alone and with additional enhancements. Low, middle, and high temperature PCM are classified, and the achievements and limitations of works are assessed. The review is categorized based upon enhancements: solely NPs, NPs and fins, NPs and heat pipes, NPs with highly conductive porous materials, NPs and multiple PCMs, and nano-encapsulated PCMs. Both experimental and numerical methods are considered, focusing on how well NPs enhanced the system. Generally, NPs have been proven to enhance PCM, with some types more effective than others. Middle and high temperatures are lacking compared to low temperature, as well as combined enhancement studies. Al2O3, copper, and carbon are some of the most studied NP materials, and paraffin PCM is the most common by far. Some studies found NPs to be insignificant in comparison to other enhancements, but many others found them to be beneficial. This article also suggests future work for NePCM and LHTES systems.

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