An Alternative Demonstration of the Carnot Efficiency “<i>Without</i>” Using the Entropy Function

Abstract

Entropy function is used to demonstrate the Carnot efficiency, even if it is not always easy to understand its bases: the reversible movement or the reversible heat transfer. Here, it is proposed to demonstrate the Carnot efficiency "without" using the Entropy function. For this, it is necessary to enhance two concepts: heat transfer based on the source temperature and work transfer based on external pressure. This is achieved through 1) a balance exchanged heat, based on the source temperature and the system temperature, and 2) a balance exchanged work, based on the external pressure and the internal pressure. With these enhanced concepts, Laplace function () Constant p v ⋅ = γ and Carnot efficiency       1 COLD Carnot HOT T T = − η can be demonstrated without using the Entropy function (). This is only a new formalism. Usual thermodynamics results are not changed. This new formalism can help to get a better description of realistic phenomena, like the efficiency of a realistic cycle.