The Component Equations of Energy and Exergy

Abstract

Energy conversion processes inherently have associated irreversibility. A better understanding of energy conversion will motivate intuition to create new energy-conversion and energy-utilization technology. In the present article, such understanding is further enhanced by decomposing the equations of energy and exergy (availability, available energy, useful energy) to reveal the reversible and irreversible parts of energy transformations. New definitions of thermal, strain, chemical, mechanical and thermochemical forms of energy/exergy are justified and expressions for these properties and their changes are rigorously developed. In the resulting equations, terms appear which explicitly reveal the interconversions between the different forms of energy/exergy, including the breakdown into reversible and irreversible conversions. The equations are valid for chemically reacting or non-reacting inelastic fluids, with or without diffusion.

Performance study of a partial gasification pressurized combustion topping gas cycle and split rankine combined cycle: Part II?Exergy analysis

“…It is observed that PFBC is by far responsible than any other components of the plant for exergy destruction. Exergy loss may arise from different sources like heat transfer with finite temperature difference, internal dissipative effects, mixing of streams, chemical reactions or interactions with the environment etc (Dunbar et al, 1992;Facchini et al, 2000). In PFBC, exergy loss occurs due to all of these factors and hence it is responsible for maximum loss.…”

“…In part I, the exergy analysis of air-cooled Brayton cycle and in part II, that of two-pressure steam bottoming cycles were discussed. For a better understanding of energy conversion processes and their inherent associated irreversibilities, Dunbar et al (1992) discussed the component equations of energy and exergy. Graphical exergy analysis of gas turbine cycle with saturated air (GTSA) was presented by Jin and Ishida (1994).…”

Exergy transfer analysis of convection heat transfer

“…Dunber [1] presented the general theory of thermodynamic exergy and its application to energy systems. Soma [2] presented design and analysis theory of exergy combined thermodynamic energy transfer with its transformation and made some application analysis.…”

A Thermodynamically Correct Treatment of Externalities with an Exergy-Based Numeraire

“…where the suffixes indicate the usual denomination of the various terms: Physical, chemical, kinetic, potential exergy [73]. If other forms of energy fluxes are involved (magnetic, nuclear, etc.…”