On the irreversible production of entropy

Abstract

The importance of irreversible entropy production is emphasized. The first and second laws of thermodynamics are both expressed by equalities by giving due recognition to the irreversible production of entropy. By specialization and combination of these equations, an "efficiency equation" is derived, applicable to cyclical and steady-state processes, and useful in studying the efficiency of practical processes. The thermodynamic theory involved in determining amounts of entropy produced by irreversible processes is investigated, and six cases of irreversible entropy production are treated in detail. The "efficiency equation" is applied to four practical processes to illustrate its usefulness in analyzing the causes of inefficiency in practical situations. The first and second law equations are directly applied to two theoretical problems so selected as to illustrate differences in the theoretical importance of being able to express the second law in the form of an equality. The concept of temperature is discussed, and the extent of its validity under non-equilibrium situations is analyzed.