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...

nowadays, energy plays an important role in the economic and community development of country. consequently, performance analysis of energy systems is one of the effective methods being used to prevent waste of energy resources. among the different power generation technologies, steam power plants make a significant contribution to power generation in iran, with a share of 47 % of electricity g...

an experimental and theoretical energy and exergy analysis was conducted for a cylindrical cavity receiver employed in a parabolic dish collector. based on simultaneous energy and exergy analysis, the receiver average wall temperature and overall heat transfer coefficient were determined. a simplified nusselt number for heat transfer fluid (htf) through the receiver as a function of reynolds an...

Energy, entropy and exergy concepts come from thermodynamics and are applicable to all fields of science and engineering. Therefore, this article intends to provide background for better understanding of these concepts and their differences among various classes of life support systems with a diverse coverage. It also covers the basic principles, general definitions and practical applications a...

This paper adds an exergy analysis of the novel SOLRGT solar-assisted power generation system proposed and described in detail in Part I of this study (Zhang and Lior, 2012, “Use of Low/Mid-Temperature Solar Heat for Thermochemical Upgrading of Energy, Part I: Application to a Novel Chemically-Recuperated Gas-Turbine Power Generation (SOLRGT) System,” ASME J. Eng. Gas Turbines Power, Accepted. ...

Exergy analysis is a powerful diagnostic tool in thermal systems performance evaluation. The use of such an analysis in seawater desalination processes is of growing importance to determine the sites of the highest irreversible losses. In the literature, exergy analyses of seawater desalination systems have sometimes modeled seawater as sodium chloride solutions of equivalent salt content or sa...

In this work, we present the application of exergy analysis in the evaluation of the ethanol steam reforming (ESR) process in a catalytic membrane reactor (CMR) containing Pd-Ag membranes sandwiched by PdRh/CeO2 catalyst to produce fuel cell grade pure hydrogen (no sweep gas). ESR experiments were performed at T=873-923 K and P=4-12 bar. The fuel was a mixture of ethanol and distilled water wit...

This paper presents a new strategy to synthesis optimum controllable heat exchanger networks; the proposed strategy consists of four sequential steps: i) Quantification of index of structural controllability. ii) Exergy analysis and normalized irreversibility. iii) Thermal effectiveness of network. iv) Fuzzy analogical gates network and selection of the best weight index. Two analogical gates (...

A multigeneration system based on solar thermal energy associated with hot and cold thermal storage is designed and analyzed energetically and exergetically. The system produces electricity, a heating effect, a cooling effect, hydrogen, and dry sawdust biomass as outputs by means of organic Rankine cycles, a heat pump, two absorption chillers, an electrolyser, and a belt dryer. The intermittent...

During the last years, special attention has been paid to renewable polygeneration technologies, able of simultaneously producing thermal, cooling, electrical energy and desalinated water from seawater. This paper focuses on an innovative polygeneration system driven by renewable energy sources, including the following technologies: hybrid photovoltaic/thermal collectors, concentrating paraboli...