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Optimization Modeling of Irreversible Carnot Engine from the Perspective of Combining Finite Speed and Finite Time
Monica Costea1, Stoian Petrescu1, Michel Feidt2
1Department of Engineering Thermodynamics, University POLITEHNICA of Bucharest, Splaiul Independentei 313, 060042 Bucharest, Romania.
Entropy (Basel, Switzerland)
|April 30, 2021
Summary
This study models irreversible Carnot engines, optimizing performance by considering piston speed and irreversibilities. Results show distinct maximums for efficiency and power, differing from time-based optimizations.
Area of Science:
- Thermodynamics
- Engineering
Background:
- Carnot cycle engines are fundamental to thermodynamics.
- Real-world engines face external and internal irreversibilities impacting performance.
Purpose of the Study:
- To model an irreversible Carnot engine using finite speed processes.
- To analyze the impact of piston speed on engine performance.
- To develop an optimization method for cycle fluid temperature.
Main Methods:
- Utilized the Direct Method and the First Law of Thermodynamics.
- Developed models incorporating external (heat transfer) and internal (pressure loss, friction) irreversibilities.
- Introduced an optimization method based on piston speed.
Main Results:
- Identified distinct maximums for thermal efficiency and power output.
- Observed different behaviors for entropy generation per cycle and per time.
- Piston speed optimization results significantly differ from Curzon-Ahlborn time-based optimization.
Conclusions:
- Piston speed is a critical factor in optimizing irreversible Carnot engines.
- Proposed corrections to unify piston speed and time-based optimization analyses.
- The study provides insights into enhancing thermodynamic engine performance under realistic conditions.
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