The Comparison of Thermodynamic and Thermoeconomic Analysis in Application to Eco-Technical System Design 2003-01-2363
The design of any complex system, especially eco-technical is very challenging due to the variety of processes, system composition, relation between different components and presence of the human. Process and technology selections affect the flow rate, composition, and phase of all resulting components. Therefore, evaluating alternative processes and/or technologies used often requires one to compare the relative environmental merits of distinctly different residual streams.
Traditional thermodynamic analysis based on the first law of thermodynamics describes the conservation of energy. In this type of analysis all forms of energy are considered to be equivalent. The loss of quality of energy is not taken into account. It shows the energy flow to be continuous and energy balance is always closed. There can never be an energy loss, only energy transfer to the environment in which case it is useless.
An exergy analysis, based on the first and second law of thermodynamics, shows the thermodynamic imperfection of a process and the system, including all quality losses of materials and energy. For quantifying the irreversibilities and determining system imperfections an exergy analysis has to be performed.
The intent of this paper is to provide a better explanation of exergy method and show examples of it's application.