Exergy of an open continuous medium

TL;DR

This paper derives a new formula for exergy in open continuous media that does not depend on an arbitrary reference state, with applications to Earth's atmosphere.

Contribution

It introduces a general exergy formula for open systems that eliminates reliance on external reference states, enhancing theoretical understanding.

Findings

Derived a formula for exergy without external reference dependence

Provided thermodynamic parameters for Earth's atmosphere in exergy analysis

Enhanced the theoretical framework of exergy in open systems

Abstract

Exergy is a very important thermodynamic quantity in several fields such as economy, engineering, ecology and yet it has attracted little attention in pure physics. One of the main problems of the currently used definition of exergy is its dependence on an arbitrarily chosen reference state, which is the thermodynamic state of a reservoir the system is supposedly in contact with. In this paper, starting from a very general definition of exergy, a formula is derived for the exergy balance of a general open continuous medium without any reference to an external environment. A formula is also derived for the most suitable thermodynamic parameters of the Earth atmosphere when seen as an external environment in the usual exergy applications.