Fundamento
Exergy of the heat
Only the Carnot fraction of the heat at Ts can be converted reversibly into work.
\(X_Q=(1-T_0/T_s)Q\)
ThermoLab · Chapter 8
Exergy, destruction and second-law efficiency
Locates irreversibilities component by component, separating quantity of energy from capacity to do work.
Motor listo
Engineering results
NOT RUNDetailed calculation reportEquations · substitution · verification
Run the calculation to generate the report.
Engineering directory
13 linked modules on a single calculation base
Open any tool without losing your chosen unit system. Each page works on its own and keeps its navigation, report and export.
01
Appendices A-1 to A-28Universal property interpolator
→02Chapters 1 and 2Pressure, temperature and general energy balance
→03Chapter 3Pure substances and equations of state
→04Chapter 4Energy integrals for closed systems
→05Chapter 5Control volumes and the first law
→06Chapters 6 and 7Second law, Carnot and entropy
→07Chapter 8Exergy, destruction and second-law efficiency
→08Chapter 9Gas power cycles
→09Chapter 10Rankine steam power cycles
→10Chapter 11Refrigeration cycles
→11Chapters 12 and 13Gas mixtures and psychrometrics
→12Chapters 14 and 15Combustion and adiabatic flame temperature
→13Chapters 16 and 17Chemical equilibrium and compressible flow
→Engineering framework
Theory, equations and conditions of use
Exergy measures the maximum useful work available in bringing a system to equilibrium with its environment. Irreversibility destroys exergy, not energy.
Fundamento
Gouy-Stodola
Exergy destruction is proportional to the entropy generated and to the reference environment.
\(X_{dest}=T_0S_{gen}\)
Fundamento
Second-law efficiency
It compares the useful product with the exergy supplied.
\(\eta_{II}=X_{producto}/X_{combustible}\)
Base documentalÇengel & Boles, 7th edition · SI appendices A-1 to A-28
USCS conversionA-1E to A-27E, via exact factors from the SI base
AlcancePreliminary design, teaching and independent verification
Engineering FAQ
Preguntas frecuentes
Can energy be destroyed?+
No; it is conserved. What is destroyed is its potential to produce work.
Why does T₀ matter?+
It defines the dead state and multiplies Sgen directly.
Where should improvements be prioritised?+
On the components with the largest Xdest, taking cost and feasibility into account as well.