6 Reversible Processes Versus Quasi-static Processes, and the
Condition of Internal Reversibility . . . . . . . . . . . . . . . . . . . . . . . . . 135
6.1 The Project of Classical Formalism . . . . . . . . . . . . . . . . . . . . . 136
6.2 Quasi-static Processes and the Classical (Caratheodory)
Formalism . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137
6.3 Infinitely Dense State Function Does Not Always
Equal to Infinitely Slow Process . . . . . . . . . . . . . . . . . . . . . . . 141
6.4 Local Thermodynamic Equilibrium and the Modern
(Brussels School) Formalism . . . . . . . . . . . . . . . . . . . . . . . . . . 142
6.4.1 The Entropy Principle of the Modern Formalism . . . . . 143
6.4.2 Temperature of Clausius’ Inequality . . . . . . . . . . . . . . 146
6.4.3 Internal Reversibility as the Condition for Defining
Entropy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146
6.5 Useful Work and Action, Which Are What Distinguishes
Reversible-Like Processes from Spontaneous Natural
Processes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 148
6.5.1 Nonreversible Processes and Reversible-like
Processes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150
6.6 Internal Reversibility and the C p À C V Question in Sect. 2.3 . . . 151
6.7 Conclusion: Nature as It Is and It Can Become . . . . . . . . . . . . 152
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 155
7 Free Energy, Exergy, and Energy: The Exergetic Content
of Energy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157
7.1 Thermodynamic Potentials and Free Energies . . . . . . . . . . . . . . 157
7.1.1 The Extremum Principle for Thermodynamic
Equilibriums of Composite Systems . . . . . . . . . . . . . . 159
7.1.2 Helmholtz Free Energy and Gibbs Free Energy . . . . . . 163
7.1.3 Example: Thermodynamics of a Battery . . . . . . . . . . . 166
7.2 Engineering Inference of the Entropy-Energy Principles . . . . . . 167
7.2.1 Why Exergy? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 168
7.2.2 Energy Equation for Open Systems . . . . . . . . . . . . . . . 169
7.3 A Brief Review of the Concept of Exergy . . . . . . . . . . . . . . . . 170
7.3.1 Exergy Components . . . . . . . . . . . . . . . . . . . . . . . . . . 171
7.3.2 Material Exergy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 172
7.3.3 Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 174
7.4 Thermodynamic Processes and Exergy Balance . . . . . . . . . . . . 174
7.4.1 Control Volume Exergy Balance . . . . . . . . . . . . . . . . . 176
7.5 Chemical Exergy and Exergy of Heat and Cold . . . . . . . . . . . . 178
7.5.1 Energy and Exergy Equations for a Control
Volume . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 179
7.5.2 Relation of Eqs. (118A) and (121) to the Gibbs
Free Energy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 179
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Condition of Internal Reversibility . . . . . . . . . . . . . . . . . . . . . . . . . 135
6.1 The Project of Classical Formalism . . . . . . . . . . . . . . . . . . . . . 136
6.2 Quasi-static Processes and the Classical (Caratheodory)
Formalism . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137
6.3 Infinitely Dense State Function Does Not Always
Equal to Infinitely Slow Process . . . . . . . . . . . . . . . . . . . . . . . 141
6.4 Local Thermodynamic Equilibrium and the Modern
(Brussels School) Formalism . . . . . . . . . . . . . . . . . . . . . . . . . . 142
6.4.1 The Entropy Principle of the Modern Formalism . . . . . 143
6.4.2 Temperature of Clausius’ Inequality . . . . . . . . . . . . . . 146
6.4.3 Internal Reversibility as the Condition for Defining
Entropy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146
6.5 Useful Work and Action, Which Are What Distinguishes
Reversible-Like Processes from Spontaneous Natural
Processes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 148
6.5.1 Nonreversible Processes and Reversible-like
Processes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150
6.6 Internal Reversibility and the C p À C V Question in Sect. 2.3 . . . 151
6.7 Conclusion: Nature as It Is and It Can Become . . . . . . . . . . . . 152
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 155
7 Free Energy, Exergy, and Energy: The Exergetic Content
of Energy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157
7.1 Thermodynamic Potentials and Free Energies . . . . . . . . . . . . . . 157
7.1.1 The Extremum Principle for Thermodynamic
Equilibriums of Composite Systems . . . . . . . . . . . . . . 159
7.1.2 Helmholtz Free Energy and Gibbs Free Energy . . . . . . 163
7.1.3 Example: Thermodynamics of a Battery . . . . . . . . . . . 166
7.2 Engineering Inference of the Entropy-Energy Principles . . . . . . 167
7.2.1 Why Exergy? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 168
7.2.2 Energy Equation for Open Systems . . . . . . . . . . . . . . . 169
7.3 A Brief Review of the Concept of Exergy . . . . . . . . . . . . . . . . 170
7.3.1 Exergy Components . . . . . . . . . . . . . . . . . . . . . . . . . . 171
7.3.2 Material Exergy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 172
7.3.3 Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 174
7.4 Thermodynamic Processes and Exergy Balance . . . . . . . . . . . . 174
7.4.1 Control Volume Exergy Balance . . . . . . . . . . . . . . . . . 176
7.5 Chemical Exergy and Exergy of Heat and Cold . . . . . . . . . . . . 178
7.5.1 Energy and Exergy Equations for a Control
Volume . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 179
7.5.2 Relation of Eqs. (118A) and (121) to the Gibbs
Free Energy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 179
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