🔥 Entropy & Exergy Analysis
Second-law analysis of open systems. Compute entropy generation, exergy destruction (Gouy-Stodola), flow exergy, heat exergy, and exergy efficiency with dead-state reference comparison.
📝 Configuration
Ṡ_gen = ṁ(s_out − s_in) − Q̇_in/T_source + Q̇_out/T_sink
Ẋ_dest = T₀ · Ṡ_gen (Gouy-Stodola)
ψ = (h − h₀) − T₀(s − s₀)
η_ex = Ẋ_out / Ẋ_in
📊 Results
Configure inputs and click Analyze to view results.
📘 Methodology
Entropy Generation
For any open system at steady state, the entropy balance gives: Ṡ_gen = ṁ(s_out − s_in) − ΣQ̇_k/T_k. Entropy generation is always ≥ 0 (Clausius inequality). It quantifies the total irreversibility in the process.
Exergy & Gouy-Stodola
Exergy (available work) is the maximum useful work obtainable as the system reaches equilibrium with the dead state (T₀, P₀). The Gouy-Stodola theorem states: Ẋ_dest = T₀·Ṡ_gen. This directly links entropy generation to lost work potential.
Dead State & Flow Exergy
The dead state is the environmental reference (typically 25°C, 101.325 kPa). Flow exergy per unit mass: ψ = (h−h₀) − T₀(s−s₀). It combines thermal, mechanical, and chemical exergy components for a flowing stream.