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The paper addresses the problem of the existence and quantification of the exergy of non-equilibrium systems. Assuming that both energy and exergy are a priori concepts, the Gibbs “available energy” A is calculated for arbitrary temperature or concentration distributions across the body, with an accuracy that depends only on the information one has of the initial distribution. It is shown that ...

Contaminants cause a decrease in the quality of materials with each recycling step. These quality losses should be minimized to increase the sustainability of resources use. Quality losses cannot be measured using weight-based recovery definitions alone, as the quality degradation cannot be translated by mass measures. Therefore, a better measure of the efficiency of resource use is investigate...

The benefits are demonstrated of using exergy to understand the efficiencies of electrical power technologies and to assist improvements. Although exergy applications in power systems and electrical technology are uncommon, exergy nevertheless identifies clearly potential reductions in thermodynamic losses and efficiency improvements. Various devices are considered, ranging from simple electric...

A new method of optimization on linear parabolic solar collectors using exergy analysis is presented. A comprehensive mathematical modeling of thermal and optical performance is simulated and geometrical and thermodynamic parameters were assumed as optimization variables. By applying a derived expression for exergy efficiency, exergy losses were generated and the optimum design and operating co...

Availability analysis is an effective approach to studying energy conversion in systems and identifying inefficiency. In the present study, a single-zone model was used to examine energy performance parameters and heat release rates. The governing equation of availability analysis was applied in the model, and the possibility of using biodiesel produced from sunflower oil as diesel engine was i...

The exergetic analysis is a tool that has been used successfully in many studies aiming a more rational energy consumption to reduce the cost of processes. With this analysis, it is possible to perform an evaluation of the overall process, locating and quantifying the degradation of exergy. This paper applies exergy approach for analyzing the heat exchanger network design and refrigeration of M...

The use of zeotropic mixtures in well-designed heat pump cycles enables considerable performance improvements. Temperature glide matching the exchange processes and recovery expansion losses by internal decrease exergy destruction yield higher cycle performances. A case study for supply to district heating is presented, indicating increases COP from 4.3 a pure fluid standard 5.2 mixture with op...