One of the main fortes of emergy analysis is its ability to account for the contribution of ecosystem goods and services, or natural capital. Other holistic analysis methods including life cycle assessment, energy and exergy analysis have ignored this crucial contribution from nature, which is the very basis of sustainability. We introduce a novel approach for an Ecologically-Based Life Cycle A...

A thermodynamic model of a compartment fire with one state variable (corresponding to the dimensionless temperature of the smoke layer) based on energy conservation is studied from the point of view of the Second Law (exergy analysis). To define the exergy rate of the process, a novel concept of mean thermodynamic temperature is introduced for the smoke layer. This parameter is the equivalent o...

this study represents effect of four variables in performance of a heat-pump in two cities of tehran and rasht. a computer program has been developed, simulating a certain heat pump acting in different environments with different refrigerants in heating season. the analysis is based on a homogeneous model. effect of different refrigerants, depth of the buried heat exchangers and moisture conten...

The term`resources' is used in many ways in different disciplines. For purposes of this paper, a resource is an essential input to the economic process. Resources may be material or immaterial (e.g. information) and material resources may be of natural origin or man-made. Services provided by nature (e.g. `assimilative capacity') are also sometimes called resources. However, in this paper, the ...

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. ...

Integrated energy systems utilizing renewable sources are sustainable and environmentally substitutes for conventional fossil-fired energy systems. A new multigeneration plant with two inputs, such as biomass and solar energy, and four useful outputs, such as cooling, heating, power, and distilled water, is presented and investigated in this paper. The proposed system includes evacuated tub...

Tubular solar thermal receivers suitable for central towers are modelled using energy and exergy analysis, in a way that allows individual inspection of the the irreversibilities associated with the various receiver heat transfer processes occurring. The model was used to compare the behaviour of four working fluids: molten salt (NaNO3/KNO3), liquid sodium metal, supercritical carbon dioxide, a...

The main goal of this paper is to analyze the exergy losses during the shock and rarefaction wave of hydrogen-air mixture. First, detonation parameters pressure, temperature, density, and species mass fraction are calculated for three cases where the hydrogen mass fraction in air is 1.5%, 2.5%, and 5%. Then, exergy efficiency is used as objective criteria of performance evaluation. A two-dimens...

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...