The Experts below are selected from a list of 297 Experts worldwide ranked by ideXlab platform
Javier Royo - One of the best experts on this subject based on the ideXlab platform.
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Structural Theory and thermoeconomic diagnosis part ii application to an actual power plant
Energy Conversion and Management, 2002Co-Authors: Antonio Valero, L Serra, Felix Lerch, Javier RoyoAbstract:In this second part of the paper, the new advances on thermoeconomic diagnosis presented in the part I are applied to the Escucha power plant, which is a 160 MW conventional coal fired power plant sited in Aragon (Spain). As a result the validity of the methodology is proved and quantified. The methodology is validated using a specific simulator of the Escucha power plant cycle, mainly based on [ASME Power Division, Paper no. 62-WA-209, 1974] method. This simulator reproduces with high accuracy the cycle behavior for different operating conditions, either in design and in off design conditions. The error is lower than 1% in most of cases. The simulated results, i.e. temperatures, pressures, mass flow rates, power and so on, are considered as plant measured and validated values. In this way all measurement uncertainties are avoided. A complete thermoeconomic diagnosis is presented applying the Structural Theory of Thermoeconomics. The impact of the component inefficiencies on the fuel plant consumption, and the effect of a component inefficiency (intrinsic malfunction) on the rest of the plant components (induced malfunctions and dysfunctions), are analyzed and quantified. The methodology is validated quantifying its accuracy.
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Structural Theory and thermoeconomic diagnosis part i on malfunction and dysfunction analysis
Energy Conversion and Management, 2002Co-Authors: Cesar Torres, L Serra, Antonio Valero, Javier RoyoAbstract:Thermoeconomic diagnosis of complex energy systems is probably the most developed application of thermoeconomic analysis [NATO ASI on thermodynamics and optimization of complex energy systems, 1999, p. 117]. It is applied to diagnose the causes of the additional fuel consumption of a steadily operating plant, due to the inefficiencies of its components. In this paper, a new method based on the Structural Theory and symbolic thermoeconomics [Energy 19 (13) (1994) 365] is introduced. It integrates the thermoeconomic methodologies developed until now, such as fuel impact and technical exergy saving [Flowers 94, Florence World Energy Research Symposium, Florence, Italy, 1994, p. 149] and let us to compute the additional fuel consumption as the sum of both the irreversibilities and the malfunction costs of the plant components. Furthermore, it will be able to quantify the effect of a component malfunction in the other components of the plant. As result, new concepts are included in the diagnosis analysis: intrinsic malfunction, induced malfunction and dysfunction. The key of the proposed method is the construction of the malfunction/dysfunction table which contains, in a very compact form, the information related with the plant inefficiencies and their effects on each component and on the whole plant. This methodology is not only a theoretical advance but also it enhances the thermoeconomic diagnosis applications, based on performance tests or simulation models. Some of them are presented in this paper using a simple example. The application of the methodology is shown in the second part of the paper.
Antonio Valero - One of the best experts on this subject based on the ideXlab platform.
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Structural Theory and thermoeconomic diagnosis part i on malfunction and dysfunction analysis
Energy Conversion and Management, 2002Co-Authors: Cesar Torres, L Serra, Antonio Valero, Javier RoyoAbstract:Thermoeconomic diagnosis of complex energy systems is probably the most developed application of thermoeconomic analysis [NATO ASI on thermodynamics and optimization of complex energy systems, 1999, p. 117]. It is applied to diagnose the causes of the additional fuel consumption of a steadily operating plant, due to the inefficiencies of its components. In this paper, a new method based on the Structural Theory and symbolic thermoeconomics [Energy 19 (13) (1994) 365] is introduced. It integrates the thermoeconomic methodologies developed until now, such as fuel impact and technical exergy saving [Flowers 94, Florence World Energy Research Symposium, Florence, Italy, 1994, p. 149] and let us to compute the additional fuel consumption as the sum of both the irreversibilities and the malfunction costs of the plant components. Furthermore, it will be able to quantify the effect of a component malfunction in the other components of the plant. As result, new concepts are included in the diagnosis analysis: intrinsic malfunction, induced malfunction and dysfunction. The key of the proposed method is the construction of the malfunction/dysfunction table which contains, in a very compact form, the information related with the plant inefficiencies and their effects on each component and on the whole plant. This methodology is not only a theoretical advance but also it enhances the thermoeconomic diagnosis applications, based on performance tests or simulation models. Some of them are presented in this paper using a simple example. The application of the methodology is shown in the second part of the paper.
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Structural Theory and thermoeconomic diagnosis part ii application to an actual power plant
Energy Conversion and Management, 2002Co-Authors: Antonio Valero, L Serra, Felix Lerch, Javier RoyoAbstract:In this second part of the paper, the new advances on thermoeconomic diagnosis presented in the part I are applied to the Escucha power plant, which is a 160 MW conventional coal fired power plant sited in Aragon (Spain). As a result the validity of the methodology is proved and quantified. The methodology is validated using a specific simulator of the Escucha power plant cycle, mainly based on [ASME Power Division, Paper no. 62-WA-209, 1974] method. This simulator reproduces with high accuracy the cycle behavior for different operating conditions, either in design and in off design conditions. The error is lower than 1% in most of cases. The simulated results, i.e. temperatures, pressures, mass flow rates, power and so on, are considered as plant measured and validated values. In this way all measurement uncertainties are avoided. A complete thermoeconomic diagnosis is presented applying the Structural Theory of Thermoeconomics. The impact of the component inefficiencies on the fuel plant consumption, and the effect of a component inefficiency (intrinsic malfunction) on the rest of the plant components (induced malfunctions and dysfunctions), are analyzed and quantified. The methodology is validated quantifying its accuracy.
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Structural Theory as standard for thermoeconomics
Energy Conversion and Management, 1999Co-Authors: Berit Erlach, L Serra, Antonio ValeroAbstract:In this paper the Structural Theory of Thermoeconomics is proposed as a standard and common mathematical formulation for all thermoeconomic methodologies employing thermoeconomic models that can be expressed by linear equations. In previous works it has been demonstrated that the Exergy Cost Theory (ECT), the AVCO approach and the Thermoeconomic Functional Analysis (TFA) can be dealt with the Structural Theory. In this paper, it is demonstrated that the Last-in-First-Out (LIFO) approach, a thermoeconomic cost accounting method, can also be reproduced with the Structural Theory. The LIFO and the Structural Theory are both applied to a combined cycle plant and it is shown that the equation systems obtained from both methods are the same. Moreover, a procedure to develop the productive structure representing the thermoeconomic model of LIFO (i.e. from which the same costing equations are obtained as with the LIFO approach) is explained in detail, which provides the tools to reproduce the costs obtained from LIFO with the Structural Theory for complex energy systems. This paper concludes a series of research works where it has been demonstrated that the most developed thermoeconomic optimization and cost accounting methodologies, as all of them employ thermoeconomic models that can easily be linearized, can be dealt with by the mathematical formalism of the Structural Theory.
L Serra - One of the best experts on this subject based on the ideXlab platform.
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Structural Theory and thermoeconomic diagnosis part i on malfunction and dysfunction analysis
Energy Conversion and Management, 2002Co-Authors: Cesar Torres, L Serra, Antonio Valero, Javier RoyoAbstract:Thermoeconomic diagnosis of complex energy systems is probably the most developed application of thermoeconomic analysis [NATO ASI on thermodynamics and optimization of complex energy systems, 1999, p. 117]. It is applied to diagnose the causes of the additional fuel consumption of a steadily operating plant, due to the inefficiencies of its components. In this paper, a new method based on the Structural Theory and symbolic thermoeconomics [Energy 19 (13) (1994) 365] is introduced. It integrates the thermoeconomic methodologies developed until now, such as fuel impact and technical exergy saving [Flowers 94, Florence World Energy Research Symposium, Florence, Italy, 1994, p. 149] and let us to compute the additional fuel consumption as the sum of both the irreversibilities and the malfunction costs of the plant components. Furthermore, it will be able to quantify the effect of a component malfunction in the other components of the plant. As result, new concepts are included in the diagnosis analysis: intrinsic malfunction, induced malfunction and dysfunction. The key of the proposed method is the construction of the malfunction/dysfunction table which contains, in a very compact form, the information related with the plant inefficiencies and their effects on each component and on the whole plant. This methodology is not only a theoretical advance but also it enhances the thermoeconomic diagnosis applications, based on performance tests or simulation models. Some of them are presented in this paper using a simple example. The application of the methodology is shown in the second part of the paper.
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Structural Theory and thermoeconomic diagnosis part ii application to an actual power plant
Energy Conversion and Management, 2002Co-Authors: Antonio Valero, L Serra, Felix Lerch, Javier RoyoAbstract:In this second part of the paper, the new advances on thermoeconomic diagnosis presented in the part I are applied to the Escucha power plant, which is a 160 MW conventional coal fired power plant sited in Aragon (Spain). As a result the validity of the methodology is proved and quantified. The methodology is validated using a specific simulator of the Escucha power plant cycle, mainly based on [ASME Power Division, Paper no. 62-WA-209, 1974] method. This simulator reproduces with high accuracy the cycle behavior for different operating conditions, either in design and in off design conditions. The error is lower than 1% in most of cases. The simulated results, i.e. temperatures, pressures, mass flow rates, power and so on, are considered as plant measured and validated values. In this way all measurement uncertainties are avoided. A complete thermoeconomic diagnosis is presented applying the Structural Theory of Thermoeconomics. The impact of the component inefficiencies on the fuel plant consumption, and the effect of a component inefficiency (intrinsic malfunction) on the rest of the plant components (induced malfunctions and dysfunctions), are analyzed and quantified. The methodology is validated quantifying its accuracy.
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Structural Theory as standard for thermoeconomics
Energy Conversion and Management, 1999Co-Authors: Berit Erlach, L Serra, Antonio ValeroAbstract:In this paper the Structural Theory of Thermoeconomics is proposed as a standard and common mathematical formulation for all thermoeconomic methodologies employing thermoeconomic models that can be expressed by linear equations. In previous works it has been demonstrated that the Exergy Cost Theory (ECT), the AVCO approach and the Thermoeconomic Functional Analysis (TFA) can be dealt with the Structural Theory. In this paper, it is demonstrated that the Last-in-First-Out (LIFO) approach, a thermoeconomic cost accounting method, can also be reproduced with the Structural Theory. The LIFO and the Structural Theory are both applied to a combined cycle plant and it is shown that the equation systems obtained from both methods are the same. Moreover, a procedure to develop the productive structure representing the thermoeconomic model of LIFO (i.e. from which the same costing equations are obtained as with the LIFO approach) is explained in detail, which provides the tools to reproduce the costs obtained from LIFO with the Structural Theory for complex energy systems. This paper concludes a series of research works where it has been demonstrated that the most developed thermoeconomic optimization and cost accounting methodologies, as all of them employ thermoeconomic models that can easily be linearized, can be dealt with by the mathematical formalism of the Structural Theory.
Yoram Lanir - One of the best experts on this subject based on the ideXlab platform.
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Mechanistic micro-Structural Theory of soft tissues growth and remodeling: tissues with unidirectional fibers
Biomechanics and Modeling in Mechanobiology, 2015Co-Authors: Yoram LanirAbstract:A new mechanistic Theory was developed for soft tissues growth and remodeling (G&R). The Theory considers tissues with unidirectional fibers. It is based on the loading-dependent local turnover events of each constituent and on the resulting evolution of the tissue micro-structure, the tissue dimensions and its mechanical properties. The Theory incorporates the specific mechanical properties and turnover kinetics of each constituent, thereby establishing a general framework which can serve for future integration of additional mechanisms involved in G&R. The feasibility of the Theory was examined by considering a specific realization of tissues with one fibrous constituent (collagen fibers), assuming a specific loading-dependent first-order fiber’s turnover kinetics and the fiber’s deposition characteristics. The tissue was subjected to a continuous constant rate growth. Model parameters were adopted from available data. The resulting predictions show qualitative agreement with a number of well-known features of tissues including the fibers’ non-uniform recruitment density distribution, the associated tissue convex nonlinear stress–stretch relationship, and the development of tissue pre-stretch and pre-stress states. These results show that mechanistic micro-Structural modeling of soft tissue G&R based on first principles can successfully capture the evolution of observed tissues’ structure and size, and of their associated mechanical properties.
Chuguang Zheng - One of the best experts on this subject based on the ideXlab platform.
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exergy cost analysis of a coal fired power plant based on Structural Theory of thermoeconomics
Energy Conversion and Management, 2006Co-Authors: Chao Zhang, Yan Wang, Chuguang ZhengAbstract:Abstract In this paper, a cost analysis method based on thermoeconomics is applied to a 300 MW pulverized coal fired power plant located in Yiyang (Hunan Province, China). This method, as derived from the second law of thermodynamics, can provide detailed analysis for cost formation of the power plant as well as the effects of different operating conditions and parameters on the performance of each individual component. To perform the thermoeconomic analysis of the plant, a simulator is developed from thermodynamic modeling of the plant. With the thermodynamic properties of the most significant mass and energy flow streams being obtained from the plant, this simulator can reproduce the cycle behavior for different operating conditions with relative errors less than 2%. The models of the simulator are refined using data from designed performance tests in this plant. After simulation, an exergy analysis is performed to calculate the exergy and negentropy of the flows. Then, a thermoeconomic model of the plant is defined based on the functionality of each component using the fuel–product definition. The distribution of the resources throughout the plant and the costs of all flows in the production structure can be calculated by solving a set of equations including the thermoeconomic model of the plant. Three thermoeconomic variables are defined for improving the exergy cost equations in the Structural Theory of thermoeconomics. Several simulation cases have been analyzed in detail using the improved exergy cost method. The results show that the specific irreversibility cost is more suitable than the unit exergy cost of product in quantifying and representing the production performance of a component. The results provide insights useful to designers and managers of the plant into the relations between the thermodynamic losses and exergetic costs. This work demonstrates the merits of this advanced thermoeconomic analysis over those conventional analysis techniques based on the first and second laws of thermodynamics.
