Exergy analysis is a technique at the forefront of applied thermodynamics research whereby systems that utilize energy are assessed in the light of the second law of thermodynamics. All forms of energy transfer and transport can be represented by equivalent exergy transfers which are, in fact, the quantities of work that could be producedfrom the same types of energy transfer or transport by perJect thermodynamic devices free to interact with a specijied reference environment. E w g y is conserved and this is a fundamental physical law. Whereas conventional energy analyses can only account for where energy is distributed, or lost @om systems of interest, exergy analysis can highlight where it is used inefficiently. This paper describes and develops the exergy analysis concept. The exergy transfers associated with various types of energy transfer and transport are defned and an 'exergy analysis toolbox' is described. In Part 2 of the paper a universal rational efficiency is described and a number of worked examples are presented to illustrate the application of exergy analysis. Some of the present limitations of the technique and areas for future development are described.* refers to the thermomechanical dead state of the The M S was

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A project has been underway at the Dublin Institute of Technology (DIT) to investigate the feasibility of a combined Otto and Stirling cycle power plant in which a Stirling cycle engine would serve as a bottoming cycle for a stationary Otto cycle engine. This type of combined cycle plant is considered to have good potential for industrial use. This paper describes work by DIT and collaborators to validate a computer simulation model of the combined cycle plant. In investigating the feasibility of the type of combined cycle that is proposed there are a range of practical realities to be faced and addressed. Reliable performance data for the component engines are required over a wide range of operating conditions, but there are practical difficulties in accessing such data. A simulation model is required that is sufficiently detailed to represent all important performance aspects and that is capable of being validated. Thermodynamicists currently employ a diverse range of modeling, analysis and optimization techniques for the component engines and the combined cycle. These techniques include traditional component and process simulation, exergy analysis, entropy generation minimization, exergoeconomics, finite time thermodynamics and finite dimensional optimization thermodynamics methodology (FDOT). In the context outlined, the purpose of the present paper is to come up with a practical validation of a practical computer simulation model of the proposed combined Otto and Stirling Cycle Power Plant.

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