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...

Exergy and thermoeconomic analyses are herein employed to evaluate the proposed refrigeration cycle of Tabriz olefin plant. The exergetic and exergoeconomic variables of all equipment and streams are calculated. Thermoeconomic model is developed according to the total revenue requirement (TRR) method. The results indicate that the rational efficiencies of the Heat Exchanger E-104 and compressor...

In this paper, exergy of conditioned air, exergy efficiency, irreversibility, and entropy generation of common models of evaporative cooling have been investigated in five cities of Iran. Direct evaporative cooling (DEC), indirect evaporative cooling (IEC), and two-stage IEC/DEC as the most popular methods of cooling have been modeled. Atmospheric conditions are considered as the dead state of ...

Several fundamental concepts with respect to the second-law analysis (SLA) of the turbulent flows in gas turbines are discussed in this study. Entropy and exergy equations for compressible/incompressible flows in a rotating/non-rotating frame have been derived. The exergy transformation efficiency of a gas turbine as well as the exergy transformation number for a single process step have been p...

The analysis of complex thermodynamic systems with exergetic and 2nd law methods is continually performed for various fields of engineering. This also applies to environmental control systems (ECS) of aircraft. This paper focuses on methods of exergy and energy analysis applied to ECS. It gives a survey of the published material and identifies the state of the art. Furthermore, this analysis in...

Refrigeration cogeneration systems which generate power alongside with cooling improve energy utilization significantly, because such systems offer a more reasonable arrangement of energy and exergy ‘‘flows’’ within the system, which results in lower fuel consumption as compared to the separate generation of power and cooling or heating. This paper proposes several novel systems of that type, b...

Abstract: The evaluation of the thermodynamic performance of the mutual transformation of different kinds of exergy linked to the intensive thermodynamic parameters of the flow inside the ejector of a refrigeration system is undertaken. Two thermodynamic metrics, exergy produced and exergy consumed, are introduced to assess these transformations. Their calculation is based on the evaluation of ...

A novel solar-based combined system which is consisting of a concentrated PV, a double effect LiBr-H2O absorption chiller, and a Proton Exchange Membrane (PEM) is proposed for hydrogen production. A portion of the received energy is recovered to run a double effect absorption chiller and the rest is turned into electricity, being consumed in the PEM electrolyzer for hydrogen producti...

In this study, the first and the second laws of thermodynamics (exergetic analysis) are used to analyse the performance of a single stage ammonia-water absorption cooling system operating under different working conditions. In this analysis, the performance of the system is simulated under various operating temperatures: the condenser and absorber (30 and 40°C), evaporator (-10°C, 0°C and +10°C...

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...