https://doi.org/10.1140/epjp/s13360-021-02124-1
Regular Article
A generalized irreversible thermal Brownian motor cycle and its optimal performance
1
Institute of Thermal Science and Power Engineering, Wuhan Institute of Technology, 430205, Wuhan, China
2
Hubei Provincial Engineering Technology Research Center of Green Chemical Equipment, 430205, Wuhan, China
3
School of Mechanical and Electrical Engineering, Wuhan Institute of Technology, 430205, Wuhan, China
4
College of Power Engineering, Naval University of Engineering, 430033, Wuhan, China
b lingenchen@hotmail.com, lgchenna@yahoo.com
Received:
19
September
2021
Accepted:
27
October
2021
Published online:
8
November
2021
A finite time thermodynamic model of generalized irreversible thermal Brownian motor is proposed, in which heat transfer rate of particles through potential field, heat absorption of particles that overcome external load, the kinetic energy loss of particles, heat flow caused by friction, heat leakage and thermal resistances between reservoir and Brownian motor are considered. The key performance parameters of Brownian motor are derived. The influences of design parameters and irreversible factors on the performances are analyzed. The performance characteristics are determined when the motor operates as a heat engine or a refrigerator. For the Brownian heat engine, the working regions are given when both the power and efficiency are large. By optimizing barrier height and the asymmetry of potential, the performance characteristics under the optimization objectives of maximum power and efficiency are obtained. For the Brownian refrigerator, the working regions are given when both the cooling load and coefficient of performance (COP) are large. By optimizing barrier height and external load, the performance characteristics under the optimization objectives of maximum cooling load and COP are obtained. The results show that external load reduces the drift velocity of particles. There exists an optimal barrier height to maximize the drift velocity or the number of particles. The design parameters influence the drift velocity and heat absorption of the particles and then modulates the performance of system. One can regulate the barrier height to satisfy that the system works in optimal regions in actual design processes. Compared with previous models, the newly established model is universal and the results obtained herein also include the previous ones.
© The Author(s), under exclusive licence to Società Italiana di Fisica and Springer-Verlag GmbH Germany, part of Springer Nature 2021
