Through online optimization and control, vapor compression systems (VCSs) can effectively respond to disturbances, such as weather or varying loads that cannot be accounted for at the design stage, while simultaneously maximizing system efficiency. However, to do so requires a mathematical characterization of efficiency for the VCS. In particular, we would like to maximize the exergetic efficie...

Contaminants cause a decrease in the quality of materials with each recycling step. These quality losses should be minimized to increase the sustainability of resources use. Quality losses cannot be measured using weight-based recovery definitions alone, as the quality degradation cannot be translated by mass measures. Therefore, a better measure of the efficiency of resource use is investigate...

The POXR and SMR methods adopted in producing hydrogen from methane gas are simulated and exergy analysis of both the processes are run for comparison. The effective parameters of the feeding materials ratio and the system temperature for maximizing hydrogen production and increasing efficiency are assessed here. Influenced by the changes in these parameters the unit efficiency is increased up ...

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 ...

Exergy analysis is important and has been widely used to evaluate the thermodynamic efficiency of a variety of processes. Therefore, there is a need to develop a tool for monitoring exergy of a process in real-time and for studying the effects of various feed, equipment, process and environmental changes. The ultimate aim of this work is to develop a tool to enable dynamic and online exergy ana...

This paper presents the exergy analysis of a desalination unit using humidification-dehumidification process. Here, this unit is considered as a thermal system with three main components, which are the heating unit by using a solar collector, the evaporator or the humidifier, and the condenser or the dehumidifier. In these components the exergy is a measure of the quality or grade of energy and...

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...

In order to achieve both power and cooling supply for users, a new combined cooling and power system using ammonia–water mixture is proposed to utilizing low grade heat sources, such as industrial waste heat, solar energy and geothermal energy. The proposed system combines a Kalina cycle and an ammonia–water absorption refrigeration cycle, in which the ammonia–water turbine exhaust is delivered...

The current research is aimed at carrying out an exergy analysis of a 33-MW gas turbine power plant that operates on the Brayton cycle. Quantitative exergy analysis for each component and for the whole system was done. Based on the exergy balance models developed, a computer program is written which is used to investigate the performance of the power plant under varying ambient and turbine inle...