An approach for thermodynamic reasoning

Re-examination of classical thermodynamics exposes some problems. The introduction of a new reasoning approach leads to a new branch of classical thermodynamics - structural thermodynamics. An inequality principle of thermodynamic state variables decouples structure of a process set with its working medium. The introduction of optimization into thermodynamic analyses changes the attitude of classical thermodynamics from observing/describing systems to controlling/optimizing the systems. To illustrate the approach, structural thermodynamic analysts are performed for reversible heat engines and a class of irreversible heat engines. This leads to and extends the classical Carnot theory.