This paper presents a comparative energy and exergy analysis of refrigerants r744, r404a and r290 operating in a singlestage vapour compression refrigeration cycle for use in medium. The software is designed for life insurance companies to assist them in the administration of their policies. This document is the 3rd version of the introduction to exergy and energy. Definition of exergy exergy is the amount of work obtainable when some matter is brought to a state of thermodynamic equilibrium with the common components of the natural surroundings by means of reversible processes, involving interaction only with the above mentioned components of nature szargut et al 1988. Exergy is a tool for detecting and diagnosing efficiency problems in thermal power stations. Nomenclature for exergy analysis t j kotas, y r mayhew, r c. Cziesla encyclopedia of life support systems eolss system are positive. Request pdf exergy analysis in prosimplus simulation software. In this chapter, an exergy analysis applied to a solid oxide fuel cell sofcvapor adsorption refrigeration var system is presented.
Exergy analysis, although used since the 80s, remains unknown and reserved to some experts because of the complex calculations and a concept exergy relatively difficult to handle. To make exergy analysis more understandable and to demonstrate its value for the analysis of the energy efficiency of a process and its utilities, a fullyautomated exergy analysis tool has been developed and integrated in prosimplus energy 3, 4. The results show that using the ert and px reduced the total power consumption of the swro. The first term at the right part is related with the difference in exergy at inlet and outlet of the system. The influences of four significant parameters current density, inlet fuel temperature, fuel utilization and steamtocarbon ratio on the exergy. The performance indicators from exergy analysis are functions of variables such as exergy of work, exergy due to heat transfer or exergy of the process stream.
This document is the 4th version of the introduction to exergy and energy. Exergy analysis indicates that maximum exergy is destroyed during combustion and steam generation, which represents around 65 per cent of the total exergy destruction in the overall system. Exergy analysis within a simulation and optimization software definition of exergy exergy is defined as the maximum theoretical useful work obtained if a system s is brought into thermodynamic equilibrium with the environment by means of reversible processes in which the system s interacts only with this environment. However, up to now the exergy concept was poorly used by process engineers, partly because it was not readily available in process simulation software. This information, which cannot be provided by other means e. In exergy analysis the same set of equations is applicable to all powerhouse components, disregarding the differences in the internal thermodynamic cycle of the components. Delft university of technology contributed to the development of a software package for exergy calculations named cycletempo. The exergy terms in the equations used here are all positive. Exergy analysis exergy analysis involves the combined application of the first and second laws of thermodynamics.
The effect of the integration of solid oxide fuel cell sofc technology was performed in a sugarethanol factory. The aim in an exergy analysis is usually to determine the exergy destructions in each component of the system and to determine exergy efficiencies. The results from exergy analysis show that the bioethanol process has the highest exergy efficiency because of usage of stillage for other processes in which a considerable part of exergy entering. Gcep energy systems analysis team has developed a number of software tools. The software combines these approaches, allowing user to propose the more efficient process. Among the different approaches existing to improve industrial processes, the exergy analysis, although limited to the academic world, has been shown to be a powerful tool for improving energy efficiency of thermal and chemical systems. To define the relationship between the calculated energy and exergy analysis results, linear regression analysis from the statistical methods is applied with the spss 17.
The method of exergy analysis is well suited for furthering this goal, for it enables the location, type and true magnitude of waste and loss to be determined. Chapter 4 exergy and exergy analysis outline fundamentals on exergy exergy associated with ke and pe irreversibility exergy destruction second law efficiency nonflow exergy exergy of a flow stream exergy by heat, work and mass exergy balance. As an innovation of lo3 energy, exergy is built on decades of expertise in energy efficiency programs and regulations, structured finance, and developing technologies. This chapter describes and illustrates the exergy analysis of a drying process applied here to moist solids. Energy and exergy analysis of a university power plant hariharan gopalakrishnan, sharan suresh, and dragoljub kosanovic, university of. Exergy calculation this chapter is intended to give the user a better knowledge of exergy calculations in cycletempo. Unfortunately, these volume licenses are becoming more. Data on energy, exergy analysis and optimisation for a. An open source exergy calculator has been created by embedding the calculation procedure in an open source chemical process simulator. A focus on exergy efficiency evaluation on industrial sites, the promotion of best practices.
An exergetic analysis was performed in ees software. Integrating numerous methods, it systematically exposes the strengths of exergy analysis in. An open source exergy calculator has been created by embedding the calculation procedure in. Computeraided simulation and exergy analysis of tio2. Exergy analysis is used in industry and industrial ecology to. The subject of this book, the exergy method also known as the availability analysis, is a method of thermodynamic analysis in which the basis of evaluation of thermodynamic losses follows from both. This serves as a potential tool for design teams to quickly evaluate. Computeraided exergy sensibility analysis of nitrobenzene. Energy and process engineering introduction to exergy and energy quality truls gundersen page 3 of 25 some text books introduce internal energy and entropy as a way to be able to formulate the 1st and 2nd laws of thermodynamics. The main purpose of an exergy analysis is to pinpoint sources and quantify its degree of thermodynamic imperfection of a process.
Taess thermoeconomic analysis of energy systems software. The bottom line is that not everyone who is using this textbook may be familiar with exergy. Exergy, energy system analysis, and optimization theme is a component of the encyclopedia of energy sciences, engineering and technology resources which is part of the global encyclopedia of life. Exergy analysis of equipment reveals that amine contactor and regenerator are the major areas of exergy destruction and least efficient among all. The syllabus exergetically efficient heat production and use in dutch deals with the analysis and assessment of energy systems for the production and use of low temperature heat. Exergy analysis is a very representative analysis method, which can be used to study various energy conversion processes, and can be used to explain the causes of irreversible energy loss during energy transfer and to have a more intuitive understanding of the exergy loss rate in the system.
The concept of chemical exergy can facilitate the computational work involved in exergy analysis. Table 2 summarizes the chemical and physical exergy of process streams, which were calculated using both mathematical equations and simulation software. Exergy analysis is a powerful tool for optimizing drying conditions, and is particularly important for largescale hightemperature drying applications in industry. Exergy analysis and design optimization for aerospace vehicles and systems progress in astronautics and aeronautics by jose a. Taess is a software tool designed for the thermoeconomic analysis of energy. Analysis of heat transfer, friction factor and exergy loss.
Wall clearly states the relation between exergy analysis and resource accounting. This chapter presents exergy analyses of several renewable energy systems including solar photovoltaic pv systems, solar ponds, wind turbines, and geothermal district heating systems and power plants. Locations and magnitude of exergy destruction is evaluated in the boiler and found that the major exergy destruction occurs at combustor followed by heat exchanger. The book provides an original and precise formulation of the chemical. Conventional and advanced exergy analyses provided the necessary information to make informed. Exergy analysis is usually used to determine exergy efficiencies and identify and quantify exergy destructions so that directions for improved efficiency can be determined.
Exergy has been developed by entropy nz and its partners. In this report, the concept of exergy and the general methodology of the exergetic analysis and the thermoeconomic combined exergetic and economic analysis of energy conversion systems are. Advanced exergy analysis of an integrated sofcadsorption. Exergy analysis is used to estimate the exergy destructions and thus to point out the malfunctions occurring in every component of the refrigerating system 12. Exergy, exergy destruction rate and exergy efficiency. Energy, exergy and thermodynamics thermodynamics, maximum power, hierarchies, and material cycles. The subject of this book, the exergy method also known as the availability analysis, is a method of thermodynamic analysis in which the basis of evaluation of thermodynamic losses follows from both the first and the second law of thermodynamics rather than just the first law. Steady state energy and exergy analysis of pulverized coal. Therefore, to say something about it, it must be known to which exergy level the calculation must be compared with. Exergy of a system is the maximum useful work possible during a process that brings the system into equilibrium with a heat reservoir.
Energy and exergy analysis of a university power plant. Students may be exposed to exergy analysis in followon courses, but these are generally technical electives. This paper presents an exergy analysis of an actual twopass ro desalination system with the seawater solution treated as a real mixture and not an ideal mixture. Abo akademi univ thermal and flow engineering, piispankatu 8, 20500 turku 11 jan 15 20102 example. Data on energy, exergy analysis and optimisation for a sugar. This important new text demonstrates exergy applications in ecology, economics, and industry. His 20plus years of industry experience run the gamut from field auditing to managing relationships. Assuming there is a property called internal energy symbol u or u in specific form. Introduction consumers are beginning to demand products that are ecofriendly over their life. The exergy balance around the system provides information concerning the efficiency of process stages and allows to identify promising improvements. Decisions are made, however, at the plant component level 8, 9. We utilize our extensive experience and our proprietary software to design the optimal heat exchanger. Exergy analysis for the performance of solar collectors.
Control volume the topic menu above allows you to move directly to any of the four sections for each topic. Comparative energy and exergy analysis of r744, r404a and. The components with greater exergy destructions are also those with more potential for improvements. Exergy destruction in a component can be determined from an exergy. In fact, it constitutes the very first presentation of the vast possibilities of important ecological applications of exergy analysis.
Prophyplus software performs fast, interactive, fluid phase equilibria and fluid. Exergy, energy system analysis and optimization vol. This section of the text lays out the history of exergy, the development of the exergy balance, and the application of the exergy. Using a simulation software to perform energy and exergy analyses.
Exergy is a potential indicator that can aid in the design of energy efficient chemical processes and plants. A lot of professional software contributers have an academical license program. Exergy analysis of a gas turbine trigeneration system. Thus, an exergy balance assesses the local destruction of the exergy. Efficiency in lng processing through exergy analysis. Energy and exergy analysis and optimum working conditions of. Exergy analysis of thermal, chemical, and metallurgical. Energy analysis can show the energy efficiency of a process but it does not tell us anything about the usability of the energy before or after it. Exergy, exergy destruction rate and exergy efficiency analysis of thermal power plants by computer software at various operating conditions.
In this research, a rigorous and detailed exergy analysis was performed on an entire actual lng process that was simulated using promax and aspen plus simulation software. Exergy is the only software available for continuous efficiency monitoring that is based on sound physics. Meanwhile, exergy is a measure of the useful work that a system can perform. Gns science is the worldwide agent for exergy sales. The next stage of work will include conducting an advanced exergy analysis upon an agru and the development of an advanced exergy analysis assistant tool. To make exergy analysis more accessible and to demonstrate its value for the analysis of the energy efficiency of a process and its utility system, a fullyautomated exergy analysis.
The analysis shows where the largest quantities of exergy are being consumed within the plant, thus pointing to areas where improvement in energy usage can be made. Energies free fulltext exergy analysis of a twopass. The study continues with an exergy analysis of the ship, since it reveals more on the system inefficiencies. Exergy analysis of distillation processes le goff 1996. Lawrence is a strong believer in the value of hard work. Multigeneration renewable energy system for dairy farms. Exergy analysis of steam power plants pdf free download.
The exergy analysis is shown as a grassmann diagram in the paper. The syllabus exergy analysis in dutch explains what exergy analysis is and what the causes of exergy losses are. Exergy analysis and energy saving are very important parameters in the heat exchanger design. The effects of surface geometry on heat transfer, friction factor and exergy loss were investigated analytically using fluent software for a flat plate heat exchanger. In this paper, a sensibility study of irreversibility due to geometrical parameters variation of a shellandtube heat exchanger is proposed by using an exergy analysis. The primary focus of the study is to identify exergy losses across a baseload lng plant producing more than 3 mta of lng. Strengths and limitations of exergy analysis springerlink. On industrial sites, the promotion of best practices to enable an efficient utilization of energy has emerged as one of the major point of focus. Accordingly, work done by the system and heat transferred from the system are negative. The exergoeconomic analysis program affords a direct connection to the process simulation software. Pdf exergy analysis within process simulation software.
Exergy method of energy systems analysis book osti. Prophyplus thermodynamic calculations software transport. Then why should govt advertisement says to save electricity switch off light and fan when. Exergoeconomics is a unique combination of exergy analysis and cost analysis conducted at the component level to provide the designer or operator of an energy conversion system with information crucial to the design or operation of a costeffective system. Analysis within a simulation and optimization software. Exergy the maximum useful work simulation and advanced modeling of thermal systems and thermoeconomic optimization energy. Exergy is software developed by silverbridge holdings, a south african developer of business software for the financial services market in africa. The energy systems analysis team supports the goals of gcep building a technical portfolio and assessing the impact of research by developing software models that allow quantitative. Exergy exergy transfer and exergy change exergy balance 1. A focus on exergy efficiency evaluation gourmelon, stephane and thery hetreux, raphaele and floquet, pascal and baudouin, olivier and baudet, philippe and campagnolo, louis exergy analysis in prosimplus simulation software. The actual 127 tonh two pass ro desalination plant was modeled using ipsepro software and validated against operating data.
The pressure drop inside the collector is introduced to the analysis. The conceptual environment provides a natural reference state for calculating absolute values of exergy. Silverbridge holdings was listed on the altx stock index on november 27 th, 2006. A simple exergy analysis for a gas processing facility is used to demonstrate the capabilities of the tool. The goal of energy systems analysis is to develop a methodology for measuring the impact of technologies from an energy and materialsusage standpoint. These can be achieved by computing the exergy balance on one hand, and estimating the exergetic efficiency of operations on the other hand. Exergy and exergoeconomic analysis of a combined cooling. Exergy analysis, being a new and useful thermodynamics tool, will be applied to one of the newest research fields in hydrogen production. The actual 127 tonh two pass ro desalination plant was modeled using ipsepro software. Exergy is not an absolute quantity but a relative one. Definition of exergy exergy is the amount of work obtainable when some matter is brought to a state of thermodynamic equilibrium with the common components of the natural surroundings by means of. Gns science is the worldwide agent for exergy sales and development. The exergy of each subsystem is a measure of its distance from equilibrium.
An advanced exergy analysis was conducted for the co 2 sequestration train and the interdependencies between compressor performance and air cooler exergy destruction were demonstrated. For calculating loss of exergy, or process irreversibility, an exergy balance or the gouystodola relation can be used. This is structured similarly to the sankey diagram above, but has dark orange arrows representing the exergy. Exergy analysis is a thermodynamic technique that evaluates a systems 2nd law efficiency. Exergy analysis is based on the relation between the actual work and the maximal work, that could be obtained in the reversible process. The exergy analysis is carried out using the second law of thermodynamics and manages the qualitative aspect of energy systems bejan, 2016. Efficiency a house, like many in finland, is electrically heated, using an electric resistance heating element that converts electricity for 100%. A computer program for the exergoeconomic analysis of energy. First, they provide a consistent interface to programmatically access the. An exergy analysis identifies the location, the magnitude and the sources of thermodynamic inefficiencies in a thermal system. Since exergy s inception in 1979, we have built our reputation worldwide for delivering unsurpassed quality heat exchangers through our engineering and manufacturing expertise. Simulation and exergy analysis of energy conversion.