Compartir
Titre
Thermodynamic Performance of a Brayton Pumped Heat Energy Storage System: Influence of Internal and External Irreversibilities
Autor(es)
Sujet
Round-trip efficiency
Irreversibilities
Brayton cycle
Heat pump
Energy storage
Fecha de publicación
2021-11
Citación
Pérez-Gallego, D.; Gonzalez-Ayala, J.; Calvo Hernández, A.; Medina, A. (2021). Thermodynamic Performance of a Brayton Pumped Heat Energy Storage System:
Influence of Internal and External Irreversibilities. Entropy, 23,
1564. https://doi.org/10.3390/
e23121564
Resumen
[EN]A model for a pumped thermal energy storage system is presented. It is based on a Brayton
cycle working successively as a heat pump and a heat engine. All the main irreversibility sources
expected in real plants are considered: external losses arising from the heat transfer between the
working fluid and the thermal reservoirs, internal losses coming from pressure decays, and losses
in the turbomachinery. Temperatures considered for the numerical analysis are adequate for solid
thermal reservoirs, such as a packed bed. Special emphasis is paid to the combination of parameters
and variables that lead to physically acceptable configurations. Maximum values of efficiencies,
including round-trip efficiency, are obtained and analyzed, and optimal design intervals are provided.
Round-trip efficiencies of around 0.4, or even larger, are predicted. The analysis indicates that
the physical region, where the coupled system can operate, strongly depends on the irreversibility
parameters. In this way, maximum values of power output, efficiency, round-trip efficiency, and
pumped heat might lay outside the physical region. In that case, the upper values are considered. The
sensitivity analysis of these maxima shows that changes in the expander/turbine and the efficiencies
of the compressors affect the most with respect to a selected design point. In the case of the expander,
these drops are mostly due to a decrease in the area of the physical operation region.
URI
DOI
10.3390/e23121564
Versión del editor
Aparece en las colecciones
- GIOETFE. Artículos [53]