FRRo - I+D+i - Artículos en Revistas
Permanent URI for this collectionhttp://48.217.138.120/handle/20.500.12272/1297
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Item Families of optimal thermodynamic solutions for combined cycle gas turbine (CCGT) power plants(Elsevier, 2009-10-30) Godoy, Ezequiel; Scenna, Nicolás José; Benz, Sonia JudithOptimal designs of a CCGT power plant characterized by maximum second law efficiency values are determined for a wide range of power demands and different values of the available heat transfer area. These thermodynamic optimal solutions are found within a feasible operation region by means of a nonlinear mathematical programming (NLP) model, where decision variables (i.e. transfer areas, power production, mass flow rates, temperatures and pressures) can vary freely. Technical relationships among them are used to systematize optimal values of design and operative variables of a CCGT power plant into optimal solution sets, named here as optimal solution families. From an operative and design point of view, the families of optimal solutions let knowing in advance optimal values of the CCGT variables when facing changes of power demand or adjusting the design to an available heat transfer area.Item Optimal life cycle oriented design of a GT + 1PSH HRSG type CCGT power plant.(2010) Godoy, Ezequiel; Benz, Sonia Judith; Scenna, Nicolás JoséIn the present work, a life cycle oriented approach is used for designing power plants in a way they can satisfy the desired demand along the whole time horizon, while a selected performance indicator of the project is optimized. As case study, optimal design characteristics as well as optimal values of long term operation parameters of a GT + 1PSH HRSG Type CCGT power plant (GT: gas turbine, 1PSH HRSG: 1 pressure with superheater-heat recovery steam generator, CCGT: combined cycle gas turbine) are obtained by means of a multiperiod mathematical model, seeing that the selected performance indicator is maximized. In addition, advantages of the life cycle oriented approach results are discussed when compared with a power plant design obtained by traditional methods.Item A strategy for the economic optimization of combined cycle gas turbine power plants by taking advantage of useful thermodynamic relationships(Elsevier, 2010-11-01) Godoy, Ezequiel; Benz, Sonia Judith; Scenna, Nicolás JoséOptimal combined cycle gas turbine power plants characterized by minimum specific annual cost values are here determined for wide ranges of market conditions as given by the relative weights of capital investment and operative costs, by means of a nonlinear mathematical programming model. On the other hand, as the technical optimization allows identifying trends in the system behavior and unveiling optimization opportunities, selected functional relationships are obtained as the thermodynamic optimal values of the decision variables are systematically linked to the ratio between the total heat transfer area and the net power production (here named as specific transfer area). A strategy for simplifying the resolution of the rigorous economic optimization problem of power plants is proposed based on the economic optima distinctive characteristics which describe the behavior of the decision variables of the power plant on its optima. Such approach results in a novel mathematical formulation shaped as a system of nonlinear equations and additional constraints that is able to easily provide accurate estimations of the optimal values of the power plant design and operative variables.Item Optimal economic strategy for the multiperiod design and long-term operation of natural gas combined cycle power plants.(Elsevier, 2012-08-25) Godoy, Ezequiel; Scenna, Nicolás José; Benz, Sonia JudithOptimal power plant designs are achieved by means of a proposed multiperiod non-linear programming formulation that utilizes the net present value as objective function, while construction, operation and dismantling of the generation facility are accounted for. In addition, optimal operative characteristics are also established for each operative time period, in a way that the system constraints are always satisfied. Based on the life cycle oriented economic optimal characteristics, a reduced model is proposed as strategy for simplifying the resolution of the rigorous multiperiod model. Trends in the system behavior are identified, enabling the reduction of the multiperiod formulation into a system of non-linear equations plus additional constraints, which allows easily computing accurate estimations of the optimal values of the design variables as well as the time-dependent operative variables.Item Impacto de nociones de disponibilidad en la evaluación económica de proyectos de generación óptimos(Federal University of Santa Catarina, 2013-10-01) Godoy, Ezequiel; Martin, Victor; Benz, Sonia JudithEl presente trabajo tiene por objetivo estudiar el impacto de considerar distintas nociones de disponibilidad durante la formulación del proyecto de inversión de una planta de generación por ciclo combinado. En primer lugar, se propone una estrategia para determinar el horizonte operativo equivalente del sistema, que incluye el cómputo de las erogaciones en que se incurren debido a la operación en todo el conjunto de estados degradados que la planta atraviesa a lo largo de su vida útil. En segundo lugar, se propone incluir una funcionalidad entre disponibilidad y recursos asignados para mantenimiento, con objeto de asegurar que se podrá alcanzar la meta de generación fijada frente a las cambiantes condiciones que la planta debe afrontar. Luego, se analizan las mejoras obtenidas en los indicadores económicos óptimos del proyecto, observándose un incremento del atractivo de las opciones de inversión generadas desde las etapas tempranas de diseño de la planta.Item A NGCC power plant with a CO2 post-combustion capture option : optimal economics for different generation/capture goals(Elsevier, 2013-11-13) Mores, Patricia Liliana; Godoy, Ezequiel; Mussati, Sergio Fabián; Scenna, Nicolás JoséFossil fuel power plants are one of the major sources of electricity generation, although invariably release greenhouse gases. Due to international treaties and countries regulations, CO2emissions reduction is increasingly becoming key in the generators’ economics. NGCC power plants constitute a widely used generation technology, from which CO2capture through a post-combustion and MEA absorption option constitutes a technological challenge due to the low concentration of pollutants in the flue gas and the high energy requirements of the sequestration process. In the present work, a rigorous optimization model is developed to address the design and operation of power plants coupled to capture systems. The equations-oriented modeling strategy here utilized can address greenfield designs in which design and operating variables are simultaneously optimized, in order to ensure that the system will be able to meet process requirements at minimum cost. Then, an analysis of the electricity cost, CO2avoidancecost, energy penalties, as well as the optimal values of decision variables is thoroughly pursued. Different economic tradeoffs are comprised at the optimal solutions for the joint project, as given by the different discrete and continuous decisions that the designer needs to weight in order to achieve the desired generation and capture goals, including the number of parallel capture trains, the inherent efficiency of each recovery unit, and the overall emissions reduction rate. In this context, the joint optimization of the NGCC power plant with the amine-based capture option results in a novel configuration where 731 MW are optimally generated for supplying both the external demand and the capture plant energy requirements, and achieving an overall CO2emissions reduction rate of 82.1% by means of a three capture trains arrangement, where 13.4% of the flue gas stream is bypassed and 94.8% of the CO2gets recovered at each unit. This new generation/capture project features optimal values of its economic performance indicators, with an avoidance cost of 81.7 US$ per tonne of CO2 captured, which can Ministerio de Educación y Deportes Universidad Tecnológica Nacional Facultad Regional Rosario Universidad Tecnológica Nacional – Facultad Regional Rosario Zeballos 1341, Rosario, Santa Fe, Argentina only be secured by simultaneously optimizing the design and operating variables of both systems on a start-of-the-art optimization algorithm.Item Una red para el análisis comparado de competencias en la trama productiva de la industria del software y servicios informáticos(2016-09-01) Riva, Fabiana María; Martín, Vilma; Amar, Eduardo; Pereira, NicolásDe los resultados obtenidos a partir del estudio de la influencia de los sectores que conforman el Triángulo de Sábato en torno a la trama productiva de la Industria del Software y Servicios Informáticos (SSI) en la Región Rosario y de la vasta bibliografía existente referida a la formulación de estrategias para la articulación de los mismos, surge como posibilidad de análisis el enfoque de competencias desde el paradigma de la complejidad. Considerando que este enfoque permite expresar un vínculo real entre Universidad-Estado-Industria, el presente trabajo realiza un abordaje para el desarrollo de una red para el análisis comparado de las competencias en los diferentes contextos. Con el objetivo de promover una interacción activa, que es dialógica entre polos que pueden ser contradictorios entre sí por sus intereses y necesidades, y es recursivo entre las demandas de la Industria, la formación ofrecida por la Universidad y las políticas del Estado, se especifican las características de la mencionada red y los avances para la determinación de los medios que permitan construir un sistema dinámico de adquisición de datos que suministre información tanto para el estudio comparado como para la definición de las estrategias apropiadas para alinear demanda, formación y políticas.Item Análisis de la molienda de expeller de soja evaluando la performance de diferentes tipos de molinos.(2017) D’Emanuele Ares, Carolina; Accoroni, Cecilia; Ferigutti, Leonardo; Godoy, Ezequiel; Reinheimer, María AgustinaEl objetivo del presente trabajo es analizar la performance del proceso de molienda y tamizado de expeller de soja, subproducto de la extracción de aceite por el método de extrusado-prensado, para su posterior utilización en la obtención de productos proteicos. La molienda se realiza con tres molinos diferentes: de bolas (impacto), de rodillos (cizalla y compresión) y de cuchillas (cizalla), bajo diferentes condiciones de operación. El análisis de tamizado se realiza utilizando la serie de tamices ASTM Nº 5, 6, 10, 12, 25, 30 y ciego. Los productos obtenidos se clasifican en finos, medios, y gruesos, analizándose así los rendimientos de cada fracción en cada molino. Al ser la fracción de interés la correspondiente a las partículas de tamaño medio, se concluye que los molinos de cuchillas y de rodillos son mas adecuados debido a que se alcanzan rendimientos superiores al 55% cuando se los opera con una sola pasada. Asimismo, se calculan y reportan las energías especıficas desarrolladas en las moliendas con la Ley de Bond para exponer una comparativa.Item An optimization model for evaluating the economic impact of availability and maintenance notions during the synthesis and design of a power plant(Elsevier, 2017-01-27) Godoy, Ezequiel; Benz, Sonia Judith; Scenna, Nicolás JoséIn this paper, we introduce an optimization strategy in order to comprehensively quantify the impact of availability and maintenance notions during the early stages of synthesis and design of a new natural gas combined cycle power plant. A detailed state-space approach is thoroughly discussed, where influence of maintenance funds on each component’s repair rate is directly assessed. In this context, analysis of the reliability characteristics of the system is centered at two designer-adopted parameters, which largely influence the obtained results: the number of components which may fail independently at the same time, and the number of simultaneous failure/repair events. Then, optimal solutions are evaluated as the availability-related parameters and the amount of resources assigned for maintenance actions are varied across a wide range of feasible values, which enable obtaining more accurate and detailed estimations of the expected economic performance for the project when compared with traditional economic evaluation approaches.Item Comparison between conventional and ultrasoundassisted techniques for extraction of anthocyanins from grape pomace. Experimental results and mathematical modeling(Elsevier, 2017-03-16) Bonfigli, Mónica Beatriz; Godoy, Ezequiel; Reinheimer, María Agustina; Scenna, Nicolás JoséConventional and ultrasound assisted extraction of anthocyanins from grape pomace are here analyzed and compared. Mathematical modeling is used firstly to represent the extraction process and determine the associated mass transport parameters, and afterwards, to obtain useful predictions on how the system behaves under different operating conditions. The mathematical model here developed is based on first-principles, in order to more accurately describe the underlying phenomena that govern the extraction process behavior. Extraction of anthocyanins from grape pomace is performed using a hydro alcoholic solution as solvent, and experimental runs at different temperatures were carried out for both conventional and ultrasound-assisted techniques. A good agreement between experimental and computed extraction yields was achieved as the reported statistical parameters indicate. Obtained results highlight the performance differences between both processes, and pinpoint which variables impact the most in the extraction yield.Item Observatorio regional de desarrollo de la ingeniería en sistemas de información e informática (IISI.d.Ro) : Avances del proyecto de desarrollo experimental(Universidad Tecnológica Nacional. Facultad Regional Avellaneda. Secretaría de Ciencia, Tecnología y Posgrado; Argentina., 2017-09-01) Riva, Fabiana María; Gatto, Miguel Ángel; Abbatemarco, Martín; Pereira, Nicolás; Cervino, Alejo; Rodríguez Guerrero, Juan ManuelEn este artículo se exponen los avances del desarrollo experimental encarado por el Proyecto: Observatorio Regional de Desarrollo de la Ingeniería en Sistemas de Información e Informática (IISI.d.r.O.). IISI.d.r.O. tiene como finalidad el diseño, construcción e implementación de una plataforma tecnológica integrada y abierta que recopile, analice y suministre información sustantiva en torno al desarrollo y evolución de las Tecnologías de Información y Comunicaciones, Software y Servicios Informáticos y su aporte a las cadenas productivas transversales, para atender a las necesidades de los sectores que conforman el Triángulo de Sábato. Basado en el ciclo de mejora a partir del que fue planteado el cronograma del Proyecto, los progresos se exponen según las plataformas: Estratégica, Tecnológica, de Suministro de Información y de Recursos Humanos. Se consideran en la exposición cuestiones que diferencian al desarrollo experimental encarado, por el ámbito universitario en que se producen. En este primer ciclo, los objetivos que se derivan de la finalidad principal de IISI.d.r.O. fueron tenidos en cuenta en creciente complejidad, avanzando durante su ejecución en cuestiones técnicas, legales y éticas. Los conocimientos adquiridos fueron transferidos en diferentes acciones y sientan las bases para el trabajo futuro de IISI.d.r.O.Item Optimization of the design, operating conditions, and coupling configuration of combined cycle power plants and CO2 capture processes by minimizing the mitigation cost.(2017-10-04) Mores, Patricia Liliana; Manassaldi, Juan Ignacio; Scenna, Nicolás José; Caballero, José Antonio; Mussati, Miguel Ceferino; Mussati, Sergio FabiánThis paper deals with the optimization of the coupling between a natural gas combined cycle (NGCC plant and a post-combustion CO2 capture process by minimizing the mitigation cost – defined as the ratio between the cost of electric power generation and the amount of CO2 emitted per unit of total net electric power generated – while satisfying the design specifications: electric power generation capacity and CO2 capture level. Three candidate coupling configurations, which differ in the place where the steam is extracted from, are optimized using detailed and rigorous models for both the NGCC and the CO2 capture plants. By comparing the mitigation cost of each configuration, the optimal integration configuration and the corresponding optimal sizes and operating conditions of all process units (steam turbines, gas turbines, heat recovery steam generators HRSGs, absorption and regeneration columns, reboilers and condensers, and pumps) are provided. In the computed optimal solution, the steam required by the CO2 capture plant is extracted from both the steam turbine and the HRSG (evaporator operating at low pressure), and the mitigation cost is 90.88 $/t CO2. The optimal solution is compared with suboptimal solutions corresponding to the other two candidate coupling schemes. These solutions are compared in detail regarding capital investment.Item Modelado matemático, validación y análisis del proceso de extracción de antocianinas en harina de orujos tintos a diferentes temperaturas.(2018-07) Bonfigli, Mónica Beatriz; Chiandoni, Florencia Soledad; Kraft, Romina Alejandra; Reinheimer, María AgustinaLa extracción sólido-líquido es una operación unitaria ampliamente utilizada para extraer compuestos biológicos de interés de diversas matrices alimentarias. En el presente trabajo se ha desarrollado un modelo matemático para el análisis del proceso de extracción de antocianinas en orujos tintos. El modelo está formado tanto por ecuaciones algebraicas como diferenciales y fue desarrollado en el software de optimización GAMS (General Algebraic Modeling System). Para la implementación de las ecuaciones a derivadas parciales en el modelo se utilizó el método implícito de discretización. Para la validación del modelo, se llevaron a cabo corridas a diferentes temperaturas de extracción (25, 45 y 65 ºC), utilizando como solvente extractor una mezcla hidro-alcohólica (50:50). Se observó un buen ajuste entre los valores óptimos obtenidos y experimentales, observándose que se obtiene una mayor eficiencia de extracción a 45 ºC.Item Optimal design of a two-stage membrane system for hydrogen separation in refining processes.(2018-10-31) Arias, Ana Marisa; Mores, Patricia Liliana; Scenna, Nicolás José; Caballero, José Antonio; Mussati, Sergio Fabián; Mussati, Miguel CeferinoThis paper fits into the process system engineering field by addressing the optimization of a two-stage membrane system for H2 separation in refinery processes. To this end, a nonlinear mathematical programming (NLP) model is developed to simultaneously optimize the size of each membrane stage (membrane area, heat transfer area, and installed power for compressors and vacuum pumps) and operating conditions (flow rates, pressures, temperatures, and compositions) to achieve desired target levels of H2 product purity and H2 recovery at a minimum total annual cost. Optimal configuration and process design are obtained from a model which embeds different operating modes and process configurations. For instance, the following candidate ways to create the driving force across the membrane are embedded: (a) compression of both feed and/or permeate streams, or (b) vacuum application in permeate streams, or (c) a combination of (a) and (b). In addition, the potential selection of an expansion turbine to recover energy from the retentate stream (energy recovery system) is also embedded. For a H2 product purity of 0.90 and H2 recovery of 90%, a minimum total annual cost of 1.764 M$·year−1 was obtained for treating 100 kmol·h−1 with 0.18, 0.16, 0.62, and 0.04 mole fraction of H2, CO, N2, CO2, respectively. The optimal solution selected a combination of compression and vacuum to create the driving force and removed the expansion turbine. Afterwards, this optimal solution was compared in terms of costs, process-unit sizes, and operating conditions to the following two suboptimal solutions: (i) no vacuum in permeate stream is applied, and (ii) the expansion turbine is included into the process. The comparison showed that the latter (ii) has the highest total annual cost (TAC) value, which is around 7% higher than the former (i) and 24% higher than the found optimal solution. Finally, a sensitivity analysis to investigate the influence of the desired H2 product purity and H2 recovery is presented. Opposite cost-based trade-offs between total membrane area and total electric power were observed with the variations of these two model parameters. This paper contributes a valuable decision support tool in the process system engineering field for designing, simulating, and optimizing membranebased systems for H2 separation in a particular industrial case; and the presented optimization resultsprovide useful guidelines to assist in selecting the optimal configuration and operating mode.Item Membrane-based processes: optimization of hydrogen separation by minimization of power, membrane area, and cost.(2018-11-12) Mores, Patricia Liliana; Arias, Ana Marisa; Scenna, Nicolás José; Caballero, José Antonio; Mussati, Sergio Fabián; Mussati, Miguel CeferinoThis work deals with the optimization of two-stage membrane systems for H2 separation from off-gases in hydrocarbons processing plants to simultaneously attain high values of both H2 recovery and H2 product purity. First, for a given H2 recovery level of 90%, optimizations of the total annual cost (TAC) are performed for desired H2 product purity values ranging between 0.90 and 0.95 mole fraction. One of the results showed that the contribution of the operating expenditures is more significant than the contribution of the annualized capital expenditures (approximately 62% and 38%, respectively). In addition, it was found that the optimal trade-offs existing between process variables (such as total membrane area and total electric power) depend on the specified H2 product purity level. Second, the minimization of the total power demand and the minimization of the total membrane area were performed for H2 recovery of 90% and H2 product purity of 0.90. The TAC values obtained in the first and second cases increased by 19.9% and 4.9%, respectively, with respect to that obtained by cost minimization. Finally, by analyzing and comparing the three optimal solutions, a strategy to systematically and rationally provide ‘good’ lower and upper bounds for model variables and initial guess values to solve the cost minimization problem by means of global optimization algorithms is proposed, which can be straightforward applied to other processes.Item A risk– based design of ammonia refrigeration systems in food manufacturing plants.(2019-01) Biscotti, Paola Silvina; Reinheimer, María Agustina; Scenna, Nicolás JoséThis paper presents a risk-based design procedure of ammonia based refrigeration processes taking into account the allocation of the manufacturing plant and the surrounding environment vulnerability at early stages of process design. In addition, the proposed design framework allows the integration of a process simulator with vulnerability assessment packages. As a case study, the design of the refrigeration system for a surimi manufacturing plant is presented.Item Development of extrinsic functions for optimal synthesis and design : application to distillation-based separation processes.(2019-04-09) Manassaldi, Juan Ignacio; Mussati, Miguel Ceferino; Scenna, Nicolás José; Mussati, Sergio FabiánThis work deals with the development and implementation of mathematical models in the General Algebraic Modeling System (GAMS) environment for optimization purposes, involving extrinsic functions that are executed outside GAMS from dynamic-link libraries (DLL) implemented in the programming language C. Three DLL libraries are developed to calculate thermodynamic properties: the Raoult's law for vapor-liquid equilibrium, the Non-Random Two-Liquid (NRTL) model, and the Peng–Robinson equation of state. A detailed description on how GAMS and DLL libraries interact is presented. Case studies dealing with the optimal design of multi-component distillation columns with increasing complexity levels are discussed. For the proposed case studies, the obtained results show that the usage of the proposed extrinsic functions allows to significantly enhance the model implementation compared to the traditional model implementation approach, and to considerably reduce the model size as well as the computational time required by the optimization algorithms.Item Cost-based comparison between membrane systems and chemical absorption processes for CO2 capture from flue gas.(2019-05-09) Arias, Ana Marisa; Mores, Patricia Liliana; Scenna, Nicolás José; Caballero, José Antonio; Mussati, Miguel Ceferino; Mussati, Sergio FabiánAn optimization study of membrane-based separation systems for carbon dioxide capture from flue gas of power plants is conducted, considering the possibility of employing up to four stages and using diverse options to create the required driving force. By proposing a superstructure-based model, the number of stages, recycle options, use of feed compression and/or permeate vacuum, driving force distribution along each membrane stage, operating conditions and equipment sizes are simultaneously optimized in order to minimize the total annual cost at high capture ratios and purity targets. Thus, different optimal arrangements are obtained and the total cost is reduced in about 20% compared without employing vacuum. Besides the optimal number of stages diminishes with decreasing purity, but it is independent of the capture ratio. Also, the total cost decreases with the increase of the membrane permeance requiring lower values of operating pressure and membrane areas. Permeance values higher than 2400 GPU lead to lower number of stages and recycles for the same separation target. By contrast, a sensitivity analysis shows that the total cost increases with the increase of the electricity price, capacity factor, and capital recovery factor, which are the more influential parameters in the objective function. Despite new optimal operating and design conditions are obtained when these parameters vary, no modifications in the optimal arrangement are observed.Item Experimental data acquisition and mathematical model for soluble protein extraction from Argentinian extruded expeller soybean meal(2019-06) Accoroni, Cecilia; Godoy, Ezequiel; Reinheimer, María AgustinaExtruded expeller soybean meal is a byproduct of the soybean oil extraction, which is frequently used in Argentina by animal feed millers. In this work, the soluble protein extraction stage is studied as the first step of a challenge project in order to obtain a soy protein product from this byproduct. Extruded expeller (EE) meals from 4 different Argentinian processing plants were used to obtain experimental data sets, using 1 to 3 consecutive extraction cycles operating at temperatures from 55 to 65ºC. Firstly, 16 data sets were used to estimate the values of the distribution constant and the diffusivity of proteins within the particle, both as function of the extraction temperature. The remaining 25 data sets were used for validation purposes. Extraction yields were analyzed considering the impact of the operating conditions, while a good agreement between experimental and predicted extraction yields was achieved as the reported statistical parameters indicate.Item Agregado de valor a expeller de soja.(2019-12) Godoy, Ezequiel; Llopart, Emilce; Morselini, Santiago; Mijoevich, Ayelén; Romero, María del Pilar; Aimaretti, Nora; Reinheimer, María AgustinaEl presente trabajo se enfoca en la extracción acuosa de proteínas a partir de expeller de soja y su posterior precipitación, así como en el análisis de los efluentes sólidos resultantes de este proceso a fines de evaluar su potencial valorización considerando principalmente el contenido de fibra dietaria. Para esto, se evaluaron y caracterizaron muestras de expeller provistas por PyMES de la región, que fueron sometidas al proceso de recuperación de proteínas y fibras bajo un amplio rango de condiciones operativas. Los resultados obtenidos fueron sometidos a análisis de varianza, y permiten detectar potenciales alternativas de procesamiento para la generación de productos de mayor valor agregado.
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