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 Optimization of triple-pressure combined-cycle power plants by generalized disjunctive programming and extrinsic functions.(2021-02-01) Manassaldi, Juan Ignacio; Mussati, Miguel Ceferino; Scenna, Nicolás José; Mussati, Sergio FabiánA new mathematical framework for optimal synthesis, design, and operation of triple-pressure steamreheat combined-cycle power plants (CCPP) is presented. A superstructure-based representation of the process, which embeds a large number of candidate configurations, is first proposed. Then, a generalized disjunctive programming (GDP) mathematical model is derived from it. Series, parallel, and combined series-parallel arrangements of heat exchangers are simultaneously embedded. Extrinsic functions executed outside GAMS from dynamic-link libraries (DLL) are used to estimate the thermodynamic properties of the working fluids. As a main result, improved process configurations with respect to two reported reference cases were found. The total heat transfer areas calculated in this work are by around 15% and 26% lower than those corresponding to the reference cases. This paper contributes to the literature in two ways: (i) with a disjunctive optimization model of natural gas CCPP and the corresponding solution strategy, and (ii) with improved HRSG configurations.Item Process optimization and revamping of combined-cycle heat and power plants integrated with thermal desalination processes.(2021-06-06) Manassaldi, Juan Ignacio; Mussati, Miguel Ceferino; Scenna, Nicolás José; Morosuk, Tatiana; Mussati, Sergio FabiánOptimal revamping, sizing, and operation of an existing gas-turbine combined-cycle dual-purpose power/desalination plant – simultaneous electricity and freshwater generation – which operates with a heat recovery steam generation with one-pressure level (1P-HRSG) and a multi-stage flash desalination process, is addressed. The sizes and configurations of the gas turbine and desalination unit are kept the same as in the existing plant through the study. However, the 1P-HRSG is conveniently extended to twoor three-pressure levels with different exchanger arrangements, including steam reheating. To this end, a superstructure-based representation of the HRSG simultaneously embedding several candidate structures was proposed and a mixed-integer nonlinear programming model was derived from it. One revamping case consisted in maximizing the ratio between the freshwater production rate and the heat transfer area of HRSG, keeping unchanged the electricity generation rate (around 73 MW). It was found that the inclusion of a 3P-HRSG resulted in an increase of 13.782 kg⋅s−1 in the freshwater production, requiring 22753 m2 of heat transfer area less in the HRSG. Another revamping case consisted in maximizing the profit, contemplating the possibility to sell extra amounts of electricity and freshwater. Sale prices, for which producing extra electricity and freshwater is beneficial, were determined.Item Obtención de correlaciones convexas para el análisis de los efectos causados por xxplosiones Tipo BLEVE : estimación de distancias de seguridad en función de niveles de vulnerabilidad especificados.(2020-12-01) Kraft, Romina Alejandra; Mores, Patricia Liliana; Scenna, Nicolás JoséEn los últimos años, debido al gran número de accidentes catastróficos en el sector industrial, la obtención de una metodología cuya aplicación contribuya a la mitigación de los daños causados ha adquirido gran importancia. En este trabajo, se obtienen dos correlaciones que describen el comportamiento de un evento específico (explosión tipo BLEVE) por medio de una combinación lineal de funciones convexas simples entre las principales variables: energía interna total del sistema al momento de la explosión, distancia y nivel de daño/tipo de receptor. La primera permite estimar la distancia de seguridad frente a una explosión de cualquier sustancia peligrosa y la segunda, el nivel de daño (expresado en términos de sobrepresión) ocasionado a un receptor ubicado a una cierta distancia del evento catastrófico. En trabajos futuros, se pretende emplear las mismas en la optimización de diseño inherentemente seguro de layout.Item BLEVE : estimación de distancias seguras basándose en variables de diseño.(2022-03-11) Kraft, Romina Alejandra; Mores, Patricia Liliana; Scenna, Nicolás JoséEntre los eventos accidentales más peligrosos se encuentran las explosiones BLEVE. Las graves consecuencias ocasionadas por la onda expansiva generada hacen indispensable su análisis. Los modelos matemáticos disponibles son complejos en cuanto a la cantidad de datos y esfuerzo computacional requeridos para su resolución. En este trabajo, se presenta un modelo simple y directo para la estimación de distancias seguras entre una fuente de explosión y un receptor caracterizado por el nivel de vulnerabilidad. La obtención del mismo se lleva a cabo mediante la selección de variables de diseño convenientes y el análisis de su influencia en los resultados brindados por un modelo matemático con fundamento teórico (modelo base), la formulación de una única expresión matemática con parámetros a determinar (modelo simple) y la resolución de un problema de optimización en el que se maximiza el R2 que resulta de la comparación entre ambos modelos. Finalmente, se demuestra una muy buena performance del modelo propuesto, permitiendo la obtención confiable de distancias seguras desde las primeras etapas del diseño.Item BLEVE: safety distances estimation by simple models based on the Jakob number.(2023-07-03) Kraft, Romina Alejandra; Mores, Patricia L.; Orellano, Santiago; Scenna, Nicolás JoséOne of the most important points in the design of inherently safe processes is to estimate reliable distances among process units at preliminary stages of the plant project to minimize losses and damages caused by the potential occurrence of technological accidents. Therefore, in this paper the achievement of simple, general, dimensionless and reliable equations (Simple Dimensionless Models SDMs) for the direct estimation of safety distances considering the occurrence of BLEVE (Boiling Liquid Expanding Vapour Explosion) event, is proposed. The developed models directly relate safety distances with critical design/operation variables (involved substance, vessel volume, target vulnerability and explosion temperature), which are easily accessible at early stages of the plant project. SDMs are achieved by analysing the influence of these simple variables on the safety distances, which are estimated using a selected rigorous model (Reference Model RfM). This task is simplified by the incorporation of the Jakob Number as an input variable, allowing to obtain dimensionless models and simultaneously an adequate representation of the explosion conditions and the involved substances. As result, the achieved SDMs demonstrate a particularly good fit with respect to the RfM estimations and, at the same time, reliability and versatility. As it is shown in the analysed study cases (involving critical decision variables for the process design and the system safety), the SDMs prove to be also accurate, general, and easily incorporable into more complex optimization problems (QRA analysis, design of emergency plans, safety distance estimation to minimize the probability of domino effects, optimal layout designs, among others).Item Membrane superstructure optimization for carbon capture from cement plants. Water content influence on optimal solution.(2023) Arias, Ana Marisa; Scenna, Nicolás José; Mores, Patricia LilianaA four-membrane superstructure, embedding different connection alternatives and driving force generation options, was extended to consider a four-component wet flue gas mixture. Three case scenarios were assessed for treating a flue gas stream from a cement plant. By minimizing the specific total annual cost (sTAC), each case converged to a distinct local optimal arrangement, achieving the same separation target (90% CO2 recovery and 95% CO2 purity on the concentrated stream), thus highlighting the versatility of the model. In terms of the same superstructure and cost model, the optimal solution for capturing CO2 from wet flue gases is approximately 1.5 times higher than that of a dry mixture. A commonly published optimal two membrane-stage configuration fails to achieve high separation targets, even with low water content. The most cost-effective approach is to eliminate water at the beginning of the process. The energy consumed for CO2 pumping and compression is offset by energy generated during retentate expansion, resulting in a surplus that reduces the overall energy consumption to drive the process.