Four different forest restoration modes (Acacia mangium plantation, mixed-native species plantation, conifer plantation and Eucalyptus plantation) were evaluated using Energy System Theory and the emergy synthesis method. In addition, the eco-exergies of the four forest restoration modes were calculated, and combined with emergy and empower density to explore the restoration and selforganizatio...

Beginning with a discussion of energy and exergy analysis definitions, the presented study provides a descriptive mathematical model for energy and exergy analysis for a co-current gas cooling tower. For this purpose using conservation laws of mass, energy and momentum, the variation of temperature and enthalpy of gas and liquid streams are predicted along the tower length and are used in order...

Abstract: In this paper, we analyze the exergy costs of a real large industrial boiler with the aim of improving efficiency. Specifically, the 350-MW front-fired, natural circulation, single reheat and balanced draft coal-fired boiler forms part of a 1050-MW conventional power plant located in Spain. We start with a diagram of the power plant, followed by a formulation of the exergy cost alloca...

Energy and exergy analyses were carried out for a pilot parabolic solar dish-Stirling System. The system was set up at a site at Kerman City, located in a sunny desert area of Iran. Variations in energy and exergy efficiency were considered during the daytime hours of the average day of each month in a year. A maximum collector energy efficiency and total energy efficiency of 54% and 12.2%, res...

Different quality, reserves and production force countries to import fossil fuels to advance their economic development. It is exergy of fossil fuels that is essentially important to economy. Thus, it forms an international exergy flow network embodied in the global fossil energy trade. Based on complex network theory, we built a global fossil energy exergy flow network with countries as nodes,...

Comparative energy and exergy investigations are reported for a transcritical N2O refrigeration cycle with a throttling valve or with an expander when the gas cooler exit temperature varies from 30 to 55 ◦C and the evaporating temperature varies from −40 to 10 ◦C. The system performance is also compared with that of similar cycles using CO2. Results show that the N2O expander cycle exhibits a l...

Abstract Pumped thermal electricity storage is a thermo-mechanical energy technology that has emerged as promising option for large-scale (grid) because of its lack geographical restrictions and relatively low capital costs. This paper focuses on 10 MW Joule-Brayton pumped system with liquid stores performs detailed conventional advanced exergy analyses this system. Results the analysis recuper...

Theoretically, the concepts of energy, entropy, exergy and embodied energy are founded in the fields of thermodynamics and physics. Yet, over decades these concepts have been applied in numerous fields of science and engineering, playing a key role in the analysis of processes, systems and devices in which energy transfers and energy transformations occur. The research reported here aims to dem...