Progress in Carnot and Chambadal Modeling of Thermomechanical Engine by Considering Entropy Production and Heat Transfer Entropy

Abstract

Nowadays the importance of thermomechanical engines is recognized worldwide. Since the industrial revolution, physicists and engineers have sought to maximize the efficiency of these machines, but also the mechanical energy or the power output of the engine, as we have recently found. The optimization procedure applied in many works in the literature focuses on considering new objective functions including economic and environmental criteria (i.e., ECOP ecological coefficient of performance). The debate here is oriented more towards fundamental aspects. It is known that the maximum of the power output is not obtained under the same conditions as the maximum of efficiency. This is shown, among other things, by the so-called nice radical that accounts for efficiency at maximum power, most often for the endoreversible configuration. We propose here to enrich the model and the debate by emphasizing the fundamental role of the heat transfer entropy together with the production of entropy, accounting for the external or internal irreversibilities of the converter. This original modeling to our knowledge, leads to new and more general results that are reported here. The main consequences of the approach are emphasized, and new limits of the efficiency at maximum energy or power output are obtained.

Performance of Universal Reciprocating Heat-Engine Cycle with Variable Specific Heats Ratio of Working Fluid

“…Using finite time thermodynamics (FTT) [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 ] to optimize the performances of practical cycles and processes, a series of achievements were made, including Novikov heat engines [ 17 , 18 , 19 , 20 , 21 ], Curzon–Ahlborn heat engines [ 22 , 23 , 24 ], solar-driven engines [ 25 , 26 ], Maisotaenko cycle [ 27 , 28 , 29 ], OTEC systems [ 30 , 31 , 32 ], Kalina cycle [ 33 ], thermoelectric devices [ 34 , 35 , 36 , 37 , 38 , 39 ], dissipative heat engine [ 40 ], refrigeration cycle [ 41 ], earth [ 42 ], quantum systems [ 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 ], economic systems [ 51 , 52 ], chemical systems [ …”

Carnot Cycle and Heat Engine: Fundamentals and Applications

“…Regarding the list of published papers annexed at the end of this editorial, it appears that six papers [1][2][3][4][5][6] are basically concerned with thermodynamics concepts. The three others [7][8][9] employ thermodynamics for specific applications.…”

“…Two papers give respectively a short history regarding efficiency at maximum power and an analysis of the methodology used in modeling and optimization of Carnot engines [2,6]. It appears that in any of the cases specific physical dimensions are correlated to the choice of objective function and constraints.…”

“…This is why we preconize the acronym FDOT (Finite physical Dimensions Optimal Thermodynamics) instead of FTT. In "Progress in Carnot and Chambadal Modeling of Thermomechanical Engines by Considering Entropy Production and Heat Transfer Entropy", Feidt and Costea [6] details some progress in Carnot and Chambadal modeling of thermomechanical engines by considering entropy production as well as heat transfer entropy.…”

“…The paper by Gonzalez-Ayala et al [1] has the same philosophy as the paper by Feidt and Costea [6] but using finite time heat engine models compared to low dissipation models. The proposed models take account of heat leak and internal irreversibilities related to time; the maximum power (MP) regime is covered.…”