Performance Analysis and Optimization for Irreversible Combined Carnot Heat Engine Working with Ideal Quantum Gases

Area of Science:

• Thermodynamics
• Quantum Mechanics
• Energy Systems Engineering

Background:

• Finite-time thermodynamics analyzes energy conversion processes under realistic constraints.
• Combined Carnot cycles offer potential for enhanced thermal efficiency and power output.
• Ideal quantum gases present unique thermodynamic properties as working fluids.

Purpose of the Study:

• To model an irreversible combined Carnot cycle using ideal quantum gases.
• To analyze the effects of thermal resistance, internal irreversibility, and heat leakage on cycle performance.
• To determine optimal operating conditions and compare different working mediums.

Main Methods:

• Developed an irreversible combined Carnot cycle model.
• Utilized finite-time thermodynamics and the quantum gas state equation.
• Employed numerical analysis and the Euler-Lagrange equation for optimization.

Main Results:

• Identified optimal working medium temperatures for maximum power output.
• Characterized performance curves: parabolic without heat leakage, loop-shaped with heat leakage.
• Demonstrated that internal irreversibility reduces both power and efficiency; heat leakage impacts efficiency only.
• Fermi-Bose gas yielded the highest power output among tested mediums.

Conclusions:

• The combined Carnot cycle's performance is significantly influenced by irreversibilities and heat leakage.
• Working medium selection, particularly ideal quantum gases like Fermi-Bose gas, is crucial for maximizing power output.
• Optimal operating conditions exist for balancing power and efficiency in these advanced thermodynamic cycles.