Coefficient of performance for a low-dissipation Carnot-like refrigerator with nonadiabatic dissipation

TL;DR

This paper analyzes the COP bounds of a Carnot-like refrigerator considering nonadiabatic dissipation and finite-time adiabatic processes, improving the accuracy of theoretical predictions for real refrigerators.

Contribution

It extends previous models by incorporating nonadiabatic dissipation and finite-time adiabatic processes, aligning theoretical bounds more closely with experimental data.

Findings

COP bounds are unchanged from idealized models despite nonadiabatic effects

Theoretical predictions match observed COPs more closely when dissipation is symmetric

Finite-time adiabatic processes significantly influence refrigerator performance bounds

Abstract

We study the coefficient of performance (COP) and its bounds of the Canot-like refrigerator working between two heat reservoirs at constant temperatures $T_h$ and $T_c$, under two optimization criteria $\chi$ and $\Omega$. In view of the fact that an "adiabatic" process takes finite time and is nonisentropic, the nonadiabatic dissipation and the finite time required for the "adiabatic" processes are taken into account. For given optimization criteria, we find that the lower and upper bounds of the COP are the same as the corresponding ones obtained from the previous idealized models where any adiabatic process undergoes instantaneously with constant entropy. When the dissipations of two "isothermal" and two "adiabatic" processes are symmetric, respectively, our theoretical predictions match the observed COP's of real refrigerators more closely than the ones derived in the previous models, providing a strong argument in favor of our approach.