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Título
Optimization, Stability, and Entropy in Endoreversible Heat Engines
Autor(es)
Materia
Multiobjective optimization
Pareto front
Stability
Maximumpower regime
Entropy behavior
Fecha de publicación
2020-11-20
Editor
MDPI
Citación
Gonzalez-Ayala, J.; Mateos Roco, J.M.; Medina, A.; Calvo Hernández, A. (2020). Optimization, Stability, and Entropy in Endoreversible Heat Engines. Entropy, 22 (11), 1323.
Resumen
[EN]The stability of endoreversible heat engines has been extensively studied in the literature.
In this paper, an alternative dynamic equations system was obtained by using restitution forces that
bring the system back to the stationary state. The departing point is the assumption that the system
has a stationary fixed point, along with a Taylor expansion in the first order of the input/output heat
fluxes, without further specifications regarding the properties of the working fluid or the heat device
specifications. Specific cases of the Newton and the phenomenological heat transfer laws in a Carnot-like
heat engine model were analyzed. It was shown that the evolution of the trajectories toward the
stationary state have relevant consequences on the performance of the system. A major role was played
by the symmetries/asymmetries of the conductance ratio shc of the heat transfer law associated with the
input/output heat exchanges. Accordingly, threemain behaviorswere observed: (1) For small shc values,
the thermodynamic trajectories evolved near the endoreversible limit, improving the efficiency and
power output values with a decrease in entropy generation; (2) for large shc values, the thermodynamic
trajectories evolved either near the Pareto front or near the endoreversible limit, and in both cases,
they improved the efficiency and power values with a decrease in entropy generation; (3) for the
symmetric case (shc = 1), the trajectories evolved either with increasing entropy generation tending
toward the Pareto front or with a decrease in entropy generation tending toward the endoreversible
limit. Moreover, it was shown that the total entropy generation can define a time scale for both the
operation cycle time and the relaxation characteristic time.
URI
ISSN
1099-4300
DOI
10.3390/e22111323
Versión del editor
Colecciones
- GIOETFE. Artículos [48]