Of evaporative cooling or energy recovery potential in HVAC, the conventional thermodynamic analysis is based on the enthalpy of moist air. In fact, the available energy of moist air is its exergy and the available energy saving potential ought to be the exergy. Isoexergic lines on psychometric charts associated with different ambient states persuade us that exergy and enthalpy are completely i...

The paper reviews various representations of exergy and exergy losses in energy systems going from simple heat exchanger (heat transfer, dissipation and embedded exergy) to the exergy of full energy systems from fossil or non fossil resources (including the diffusion exergy). The systems shown include shell in tube heat exchangers, thermal power cycles, cogeneration, heat pump direct heating sy...

The current research is aimed at carrying out an exergy analysis of a 33-MW gas turbine power plant that operates on the Brayton cycle. Quantitative exergy analysis for each component and for the whole system was done. Based on the exergy balance models developed, a computer program is written which is used to investigate the performance of the power plant under varying ambient and turbine inle...

This study proposes the concept of the local heat loss coefficient and examines the calculation method for the average heat loss coefficient and the average absorber plate temperature. It also presents an exergy analysis model of flat plate collectors, considering non-uniformity in temperature distribution along the absorber plate. The computation results agree well with experimental data. The ...

Exergy is precious energy. On the basis of thermodynamic analysis of thermal processes, one can choose more exergy-saving devices. This is especially important in refrigeration processes, in which the consumption of energy and exergy increases considerably with the falling cooling temperature. The exergy efficiency in terms of exergy losses of vapour compression and sorption cooling processes i...

Usually efficiency is defined in energetic terms without taking into account the quality of the energy. Another way to analyse and optimise processes and systems is in terms of exergy. The concept of exergy incorporates both qualitative and quantitative properties of energy. Exergy analysis makes the exact determination of the energetic and resource saving potential of industrial processes or s...

Exergy analysis is important and has been widely used to evaluate the thermodynamic efficiency of a variety of processes. Therefore, there is a need to develop a tool for monitoring exergy of a process in real-time and for studying the effects of various feed, equipment, process and environmental changes. The ultimate aim of this work is to develop a tool to enable dynamic and online exergy ana...

Exergy is demonstrated to be a useful measurable parameter reflecting the state of the ecosystem, and allowing estimation of the severity of its anthropogenous damage. Exergy is shown to have advantages such as good theoretical basis in thermodynamics, close relation to information theory, rather high correlation with others ecosystem goal functions and relative ease of computation. Nowadays ex...

This paper employs an un-weighted and weighted exergy network to study the properties of ferrous metal ores in countries worldwide and their evolution from 2002 to 2012. We find that there are few countries controlling most of the ferrous metal ore exports in terms of exergy and that the entire exergy flow network is becoming more heterogeneous though the addition of new nodes. The increasing o...

In this paper, a comparison of exergetic models between two hot air engines (a Gamma type Stirling prototype having a maximum output mechanical power of 500 W and an Ericsson hot air engine with a maximum power of 300 W) is made. Referring to previous energetic analyses, exergetic models are set up in order to quantify the exergy destruction and efficiencies in each type of engine. The repartit...