Special Issue "Exergy: Analysis and Applications"

Guest Editor
Prof. Dr. Marc A. Rosen
Faculty of Engineering and Applied Science, University of Ontario, Institute of Technology, 2000 Simcoe Street North, Oshawa, Ontario, L1H 7K4, Canada
Website: http://www.engineering.uoit.ca/people/rosen
E-Mail:
Interests: sustainable development; energy; exergy; efficiency; environmental impact; economics; ecology; sustainable engineering and design

Exergy analysis is a powerful thermodynamic technique for assessing and improving the efficiency of processes, devices and systems, as well as for enhancing environmental and economic performance. As a multidisciplinary concept, exergy applications are observed in various fields, including mechanical and chemical engineering as well as economics, management, physics and biology. Consequently, exergy analysis is used increasingly by industries and governments throughout the world, particularly with the aim of improving energy sustainability. Research and review articles on all facets of exergy and its applications, and on exergy-related topics, are sought for this special issue.

Thermodynamics, irreversibility, second law analysis, exergy efficiency, exergy resources, entropy, exergoeconomics, thermoeconomics, optimisation, environomics, exergetic life cycle assessment, regional and national exergy utilisation

Type of Paper: Article
Title: Measured Entropy Production in a Rotational Magnetic Stirring Tank and Parallel Channel Flow
Authors: Olusola Adeyinka ¹ and Greg F. Naterer ²
Affiliations: ¹ Imperial Oil Resources, Calgary, Alberta, Canada
² University of Ontario Institute of Technology, Oshawa, Ontario, Canada; E-Mail: Greg.Naterer@uoit.ca
Abstract: An experimental design is presented for an optical method of measuring spatial variations of flow irreversibilities in laminar viscous fluid motion. Pulsed laser measurements of fluid velocity with PIV (Particle Image Velocimetry) are post-processed to determine the local flow irreversibilities. The experimental technique yields whole-field measurements of instantaneous entropy production with a non-intrusive, optical method. Unlike point-wise methods that give measured velocities at single points in space, the PIV method is used to measure spatial velocity gradients over the entire problem domain. When combined with local temperatures and thermal irreversibilities, these velocity gradients can be used to find local losses of energy availability and exergy destruction. This article focuses on the frictional portion of entropy production, which leads to irreversible dissipation of kinetic energy to internal energy through friction. Such effects are significant in various technological applications, ranging from power turbines and internal duct flows and turbomachinery. Specific problems of a rotational stirring tank and channel flow are examined in this paper. By tracking the local flow irreversibilities, designers can focus on problem areas of highest entropy production to make local component modifications, thereby improving the overall energy efficiency of the system.

Type of Paper: Review
Title: Exergy as a Tool for Ecosystem Health Assessment
Author: Eugene A. Silow
Affiliation: Institute of Biology at Irkutsk State University, Irkutsk, Russia, 664003, e-mail: eugenesilow@hotmail.com
Abstract: Exergy is demonstrated to be useful measurable parameter reflecting the state of the ecosystem, and allowing estimating the severity of its anthropogenous damage. It is shown to have such advantages as good theoretical basis in thermodynamics, close relation to information theory, rather high correlation with others ecosystem goal functions and relative easiness of computation. Now exergy in various forms (so called structural exergy, exergy index, eco-exergy) is more and more often used in ecological assessment. The paper reviews the application of exergy in ecology in the fields of ecological modelling (both mathematical and physical), and natural ecosystem monitoring. Special attention is paid to the use of exergy for aquatic ecosystem studies, particularly, lake Baikal ecosystem state assessment.

Type of Paper: Article
Title: Thermoeconomics and Industrial Ecology, a General Theory
Authors: Antonio Valero, Sergio Usón, César Torres and Alicia D. Valero
Affiliation: CIRCE, Centre of Research for Energy Resources and Consumptions, Universidad de Zaragoza, Zaragoza, Spain; E-Mail: valero@unizar.es
Abstract: Industrial Ecology entails the transformation of industrial processes from linear to closed loop systems: matter and energy flows which were wastes in the first situation, become resources for existing or new processes in the second. Each integration of waste produced in a given process (1) as input for another process (2) causes savings of natural resources: those consumed by (2) and those needed for the transformation of the waste in order to minimize its environmental impact. Besides, Thermoeconomic analysis is a general framework for synthesis, analysis and diagnosis of systems comprising energy and matter flows, by using the concepts of exergy and cost.
A general theory has been developed that applies exergy and thermoeconomic analyses for the study of flow integration which characterizes Industrial Ecology. Considering the equation F= P+R+I, where F is the vector of fuels entering the components, P for products, R for wastes and I for irreversibilities occurring in a plant production, it is possible to distinguish the productive structure, in which the production process is followed, and the waste structure from where wastes are formed to where they are disposed of. Now, the mathematical case of integrating two or more productive structures and two or more residual structures to finally result in the lowest cost of production is tackled. The formulation developed quantifies the resources saved in relation with the amount and cost of waste recycled, the cost of resource substituted and other parameters related to the treatment processes. Accordingly, the methodology provides a systematic and general approach for the analysis of waste flow integration.
A working example is presented to illustrate the capability of the approach.