Geometrical formulation of adiabatic pumping as a heat engine

The thermal calculation of the locomotive traction engine collector is proposed. The equations of the heat balance of its elements are obtained taking into account the cooling air. The calculation results and experimental data of thermal imaging control are presented. Keywords: traction electric motor, collector, thermal calculation, thermal imaging control. [email protected]

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Processes and Responses

10.1093/oso/9780199595068.003.0007 ◽

2017 ◽

Author(s):

Jochen Rau

Keyword(s):

Heat Engine ◽

Cyclic Process ◽

Free Enthalpy ◽

Initial State ◽

Thermodynamic Potentials ◽

Grand Potential ◽

Laws Of Thermodynamics ◽

Cyclic Processes ◽

Energy Exchanges ◽

Thermodynamic Processes

Thermodynamic processes involve energy exchanges in the forms of work, heat, or particles. Such exchanges might be reversible or irreversible, and they might be controlled by barriers or reservoirs. A cyclic process takes a system through several states and eventually back to its initial state; it may convert heat into work (engine) or vice versa (heat pump). This chapter defines work and heat mathematically and investigates their respective properties, in particular their impact on entropy. It discusses the roles of barriers and reservoirs and introduces cyclic processes. Basic constraints imposed by the laws of thermodynamics are considered, in particular on the efficiency of a heat engine. The chapter also introduces the thermodynamic potentials: free energy, enthalpy, free enthalpy, and grand potential. These are used to describe energy exchanges and equilibrium in the presence of reservoirs. Finally, this chapter considers thermodynamic coefficients which characterize the response of a system to heating, compression, and other external actions.

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A One Hundred Watt Sodium Heat Engine

22nd Intersociety Energy Conversion Engineering Conference ◽

10.2514/6.1987-9381 ◽

1987 ◽

Author(s):

J.V. Lasecki ◽

R.F. Novak ◽

J.R. McBride ◽

J.T. Brockway ◽

T.K. Hunt

Keyword(s):

Heat Engine

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Modeling and Performance Optimization of an Irreversible Two-Stage Combined Thermal Brownian Heat Engine

Entropy ◽

10.3390/e23040419 ◽

2021 ◽

Vol 23 (4) ◽

pp. 419

Author(s):

Congzheng Qi ◽

Zemin Ding ◽

Lingen Chen ◽

Yanlin Ge ◽

Huijun Feng

Keyword(s):

Power Output ◽

Performance Optimization ◽

External Load ◽

Thermal Contact ◽

Heat Engine ◽

Design Parameters ◽

Load Effect ◽

Heat Engines ◽

Heat Leakage ◽

Steady Current

Based on finite time thermodynamics, an irreversible combined thermal Brownian heat engine model is established in this paper. The model consists of two thermal Brownian heat engines which are operating in tandem with thermal contact with three heat reservoirs. The rates of heat transfer are finite between the heat engine and the reservoir. Considering the heat leakage and the losses caused by kinetic energy change of particles, the formulas of steady current, power output and efficiency are derived. The power output and efficiency of combined heat engine are smaller than that of single heat engine operating between reservoirs with same temperatures. When the potential filed is free from external load, the effects of asymmetry of the potential, barrier height and heat leakage on the performance of the combined heat engine are analyzed. When the potential field is free from external load, the effects of basic design parameters on the performance of the combined heat engine are analyzed. The optimal power and efficiency are obtained by optimizing the barrier heights of two heat engines. The optimal working regions are obtained. There is optimal temperature ratio which maximize the overall power output or efficiency. When the potential filed is subjected to external load, effect of external load is analyzed. The steady current decreases versus external load; the power output and efficiency are monotonically increasing versus external load.

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Optimization of an active heat engine

Physical Review E ◽

10.1103/physreve.103.052134 ◽

2021 ◽

Vol 103 (5) ◽

Author(s):

Giulia Gronchi ◽

Andrea Puglisi

Keyword(s):

Heat Engine

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Learning the best nanoscale heat engines through evolving network topology

Communications Physics ◽

10.1038/s42005-021-00553-z ◽

2021 ◽

Vol 4 (1) ◽

Author(s):

Yuto Ashida ◽

Takahiro Sagawa

Keyword(s):

Network Topology ◽

Heat Engine ◽

Search Space ◽

Single Electron ◽

Thermodynamic Efficiency ◽

Full Potential ◽

Thermal Systems ◽

Nanoscale Systems ◽

Heat Engines ◽

Many Body Interactions

AbstractThe quest to identify the best heat engine has been at the center of science and technology. Considerable studies have so far revealed the potentials of nanoscale thermal machines to yield an enhanced thermodynamic efficiency in noninteracting regimes. However, the full benefit of many-body interactions is yet to be investigated; identifying the optimal interaction is a hard problem due to combinatorial explosion of the search space, which makes brute-force searches infeasible. We tackle this problem with developing a framework for reinforcement learning of network topology in interacting thermal systems. We find that the maximum possible values of the figure of merit and the power factor can be significantly enhanced by electron-electron interactions under nondegenerate single-electron levels with which, in the absence of interactions, the thermoelectric performance is quite low in general. This allows for an alternative strategy to design the best heat engines by optimizing interactions instead of single-electron levels. The versatility of the developed framework allows one to identify full potential of a broad range of nanoscale systems in terms of multiple objectives.

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Can Quantum Correlations Lead to Violation of the Second Law of Thermodynamics?

Entropy ◽

10.3390/e23050573 ◽

2021 ◽

Vol 23 (5) ◽

pp. 573

Author(s):

Alexey V. Melkikh

Keyword(s):

Quantum Entanglement ◽

Local Equilibrium ◽

Heat Engine ◽

Thermodynamic Quantity ◽

Second Law Of Thermodynamics ◽

Quantum Correlations ◽

Von Neumann Entropy ◽

Second Law ◽

Carnot Cycle ◽

Technical Discussion

Quantum entanglement can cause the efficiency of a heat engine to be greater than the efficiency of the Carnot cycle. However, this does not mean a violation of the second law of thermodynamics, since there is no local equilibrium for pure quantum states, and, in the absence of local equilibrium, thermodynamics cannot be formulated correctly. Von Neumann entropy is not a thermodynamic quantity, although it can characterize the ordering of a system. In the case of the entanglement of the particles of the system with the environment, the concept of an isolated system should be refined. In any case, quantum correlations cannot lead to a violation of the second law of thermodynamics in any of its formulations. This article is devoted to a technical discussion of the expected results on the role of quantum entanglement in thermodynamics.

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