Revisiting Endoreversible Carnot Engine: Extending the Yvon Engine

Area of Science:

• Thermodynamics
• Heat Engines

Background:

• The Curzon-Ahlborn (CA) engine, introduced in 1975, is a foundational model in finite-time thermodynamics.
• The Yvon engine, proposed in 1955, shares the same maximum power efficiency as the CA engine but had limited influence due to its specific setup.

Purpose of the Study:

• To generalize the Yvon engine model to a level comparable with the CA engine.
• To explain the universality of maximum power efficiency being independent of heat transfer coefficients.

Main Methods:

• Extension of the Yvon engine model.
• Derivation of the power expression for the extended Yvon engine.
• Comparative analysis of the extended Yvon engine and the CA engine.

Main Results:

• The generalized Yvon engine achieves a level of generality similar to the CA engine.
• The universality of the Curzon-Ahlborn efficiency (ηCA) being independent of heat transfer coefficients is demonstrated.
• The extended Yvon engine and CA engine are shown to be equivalent, representing steady-state and cyclic forms, respectively.

Conclusions:

• The extended Yvon engine provides a more general framework for analyzing endoreversible Carnot heat engines.
• Finite-time thermodynamics can be understood through both steady-state (Yvon) and cyclic (CA) models.
• The efficiency at maximum power for these engines is a universal characteristic, independent of specific heat transfer details.