Efficiency and power of minimally nonlinear irreversible heat engines with broken time-reversal symmetry

TL;DR

This paper investigates minimally nonlinear irreversible heat engines with broken time-reversal symmetry, deriving power and efficiency expressions, and demonstrating the potential to surpass traditional efficiency limits like the Curzon-Ahlborn bound.

Contribution

It introduces a framework for analyzing nonlinear irreversible heat engines with broken symmetry, showing they can achieve Carnot efficiency at positive power and exceed the Curzon-Ahlborn limit.

Findings

Carnot efficiency can be achieved at positive power.

Breaking time-reversal symmetry allows surpassing the Curzon-Ahlborn limit.

Derived expressions include effects of nonlinear dissipation terms.

Abstract

We study the minimally nonlinear irreversible heat engines in which the time-reversal symmetry for the systems may b e broken. The expressions for the power and the efficiency are derived, in which the effects of the nonlinear terms due to dissipations are included. We show that, as within the linear responses, the minimally nonlinear irreversible heat engines enable attainment of Carnot efficiency at positive power. We also find that the Curzon-Ahlborn limit imposed on the efficiency at maximum power can be overcomed if the time-reversal symmetry is broken.