A Synthesis of Thermodynamic Models Unifying Traditional and Work-Driven Operations with Heat and Mass Exchange

摘要

A novel trend in the theory of thermodynamic limits for energy convertors and traditional heat and mass exchangers is analyzed, where certain special controls called, the Carnot control variables, play a common role. In terms of these controls an expression for the lost work has the same form in irreversible energy convertors and in traditional processes of purely dissipative transport. For sequential-type equipment of a finite size, enhanced limits are obtained for the energy production or consumption. Formal models of simplest energy convertors and characteristics of endoreversible operations are particularly lucid in terms of the Carnot controls. Progress in the theory of energy generation problems is achieved; examples of applications are outlined. Efficiency decrease caused by dissipation and finite rate bounds are estimated for work released from an engine or work added to a heat pump. It is shown that a simplification in the analysis of energy limits in complex thermal operations is achieved when Carnot controls are applied. Extensions involve mass transfer problems and a finite-rate counterpart of classical available energy (exergy).