NONEQUILIBRIUM THERMODYNAMICS OF ENERGY TRANSFORMATIONS

Important aspects of classical and nonequilibrium thermodynamics developed separately and lack alignment. Confusing definitions of heat and work exist for open systems in association with the exchange of matter. The concept of heat exchange in open systems requires clarification on the basis of calorimetric principles, whereas power is rigorously defined in terms of external work per time and the product of internal flows and forces. For illustration, analogous electric, thermal and chemical flows and forces are represented. An internal flow is the advancement of a transformation per time. A force is the partial Gibbs (Helmholtz) energy change per advancement. These relations are developed on the basis of the second law of thermodynamics with reference to entropy production, efficiency and energy dissipation. The symbols of nonequilibrium thermodynamics are not generally in line with IUPAC conventions. Any attempt towards a reconciliation necessarily leads to symbols which are unconventional in either tradition. Importantly, improvement of terminological consistency is a basis for conceptual clarification.