The vitality of the society is strongly depending on the management of physical, environmental and human resources. The dilemma of the modern society can be stated: misuse of physical resources from poor understanding of concepts such as exergy, misuse of nature from ignorance of ecology and misuse of people or human intelligence from lack of democracy. Exergy is a well-established concept in e...

This paper presents an abbreviated method for estimating exergy destruction in a heat exchanger, requiring only black-box data of the exchanger’s inputs and outputs, and eliminating part of the mathematical difficulties associated with the calculations. A well-known model for temperature distributions in an exchanger is adapted for this case, and is used to distinguish between the contributions...

Metal Foam-enhanced Cascaded Thermal Energy Storage (MF-CTES) has been proposed to solve the problem of poor heat transfer during heat exchange process, which is caused by unavoidable decrease of temperature differences. This paper conducts a theoretical study examining the overall thermal performance of STES (Single-stage Thermal Energy Storage), CTES (Cascaded Thermal Energy Storage) and MF-C...

The application of ecological exergy as a suitable system-oriented development indicator of ecosystems and the estimation proposals from biomass are revised. DNA contents (C-values) of several groups of organisms are figured, either determined by flow cytometry or taken from literature. The applicability of DNA contents for determination of weighing factors to estimate ecological exergy from th...

This paper analyzes the energetic and exergy performance of an active magnetic regenerative refrigerator using water-based Al2O3 nanofluids as heat transfer fluids. A 1D numerical model has been extensively used to quantify the exergy performance of a system composed of a parallel-plate regenerator, magnetic source, pump, heat exchangers and control valves. Al2O3-water based nanofluids are test...

A thermodynamic model of a thermoelectric generator-driven thermoelectric heat pump (TEG-TEH) combined device is established considering the Thomson effect and the temperature dependence of the thermoelectric properties based on non-equilibrium thermodynamics. Energy analysis and exergy analysis are performed. New expressions for heating load, maximum working temperature difference, coefficient...

exergy analysis of an integrated molten carbonate fuel cell-turbo expander-steam turbine hybrid cycle has been presented in this study. the proposed cycle has been used as a sustainable energy approach to provide a micro hybrid power plant with high exergy efficiency. to generate electricity by the mentioned system, an externally reformed molten carbonate fuel cell located upstream of the combi...

the exergy analysis is a proper method for performance evaluation of industrial systems. a generic and detailed analysis of the gpcss on the second gas pipeline of iran  is made by the means of exergy. the two main improvement measures of fuel pre-heating and steam injection technologies are presented for the current conventional stations. steady state equations regarding the second law of ther...

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...