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Μέθοδος ταχέως προσδιορισμού κύριων συστατικών μεταλλουργικών σκωρίων (FeO, CaO, MgO, SiO2)Παλάγκας, Χρήστος 14 January 2009 (has links)
Ο βασικός στόχος της συγκεκριμένης διατριβής ήταν να εξεταστεί η δυνατότητα της τεχνικής LIBS όσον σφορά την ταχεία ποιοτική και ποσοτική ανάλυση της μεταλλουργικής σκωρίας (σε στερεή και υγρή μορφή) σε εργαστηριακή και βιομηχανική κλίμακα.
Η τεχνική εφαρμόστηκε αρχικά σε καθαρά μέταλλα και έπειτα σε πρότυπα δείγματα τα οποία περιείχαν τα αντίστοιχα στοιχεία σε μήτρα CaO. Μελετήθηκαν τα χαρακτηριστικά του πλάσματος που παράγεται από παλμούς διάρκειας των τάξεων nsec και psec. Η θερμοκρασία πλάσματος και η ηλεκτρονική πυκνότητα μειώνονται παρόμοια ενώ υπολογίστηκαν ελαφρώς υψηλότερες τιμές στην περίπτωση του ns λέιζερ. Οι καμπύλες βαθμονόμησης έδειξαν πως η ευαισθησία της μεθόδου παραμένει σχεδόν η ίδια ανεξαρτήτως της διάρκειας παλμού. Τα όρια ανίχνευσης κυμάνθηκαν στην τάξη μερικών μερών του εκατομμυρίου (ppm).
Στη συνέχεια μελετήθηκαν οι δυνατότητες της τεχνικής για on-line ανάλυση της σκωρίας.
Ο δυνατότητες της τεχνικής εξαρτώνται κυρίως από τον λόγο (κρατήρας λέιζερ, ΚΛ)/(μέγεθος σχηματιζόμενης φάσης, ΜΣΦ), οι επιφανειακές ανωμαλίες στην στερεοποιημένη σκωρία καθώς και από την κατανομή του κάθε στοιχείου στην μήτρα. Διαπιστώθηκε πως ο βαθμός ανομοιογένειας της σκωρίας δεν επιδρά σημαντικά στην ακρίβεια της μεθόδου όταν ο λόγος ΚΛ/ΜΣΦ είναι μεγάλος. Σημαντική παράμετρος αποτελεί το γεγονός εάν τα στοιχεία βρίσκονται κατανεμημένα στην μήτρα της σκωρίας ή σε κάποια κρυσταλλική φάση. Η επίδραση των επιφανειακών ανωμαλιών στην ακρίβεια της μεθόδου μειώθηκε με την θραύση και πελλετοποίηση της σκωρίας αλλά, κυρίως για τα στοιχεία τα οποία βρίσκονται κατανεμημένα στην μήτρα της σκωρίας, προτείνεται η αποφυγή της πελλετοποίησης για ανάλυση με χρήση της μεθόδου LIBS.
Η ακρίβεια της τεχνικής εξαρτάται σε μεγάλο βαθμό από τα πρότυπα δείγματα που θα χρησιμοποιηθούν για την κατασκευή των καμπύλων βαθμονόμησης.
Οι καμπύλες βαθμονόμησης της υγρής σκωρίας εμφάνισαν ικανοποιητική γραμμική εξάρτηση μεταξύ της έντασης των γραμμών εκπομπής των στοιχείων με τις αντίστοιχες συγκεντρώσεις ενώ παρατηρήθηκε μικρή αύξηση όσον αφορά τις τιμές των εντάσεων της υγρής σκωρίας σε σχέση με αυτές της στερεάς σκωρίας κάτω από τις ίδιες πειραματικές συνθήκες.
Επίσης παρατηρήθηκε μεγαλύτερη διαπλάτυνση στις γραμμές κάποιων στοιχείων στην υγρή σκωρία. Για συγκεντρώσεις >4-5% παρατηρήθηκε επίσης αύξηση στην κλίση των καμπύλων για την περίπτωση της υγρής σκωρίας. Τέλος, κάθε στοιχείο συμπεριφέρεται διαφορετικά σε σχέση με τα υπόλοιπα, από δείγμα σε δείγμα αλλά και από φάση σε φάση. / To investigate the ability of LIBS technique considering the rapid qualitative and quantitative analysis of metallurgic slag was the main objective of the particular thesis.
Firstly, the LIBS technique applied on pure metals and then on samples containing the same metals in CaO matrix and the time-resolved characteristics of the plasmas produced by nsec and psec pulses were studied. Both the plasma temperature and electron density are decaying similarly and the space-averaged values determined in the nanosecond case are slightly higher than for the picosecond one. Moreover, the calibration curves obtained, show that the inherent sensitivity of the technique remains almost unaltered independently of the pulse duration. The detection limits were found to be few ppm.
Then, the potentiality of LIBS method for quantitative on-line, multi-element slag analysis on plant scale was examined.
Further, in order to examine more closely the produced slag, slag samples were analysed in the laboratory. The measurements were performed on solidified slag samples in a pelletized form and on as delivered solidified slag samples.
The limits of the accuracy of this technique depend mainly on the laser spot/phase size ratio, the level of surface abnormalities and the distribution of each element in the matrix. The non-homogeneity level of the slag product seems to be not important in LIBS analysis, when the above ratio is quite large. It is of great importance whether the element is embedded in the matrix or in a specific crystallized phase. The influence of surface abnormalities is reduced in the case of pressed slag, but primarily for the elements distributed in the matrix, fragmentation of the slag should be avoided.
The accuracy of LIBS quantitative slag analysis is strongly dependent on the standard samples that are used
Regarding the liquid slag analysis, the calibration curves presented satisfactory linear dependence between the intensity of analytic lines with the corresponding concentrations while the intensity values of liquid slag appeared to be relatively increased with regard to the intensity values of solid slag under the same experimental conditions.
Widening phenomena were characterized the lines of certain elements in liquid slag. For concentrations >4-5% an increased slope in calibration curves of liquid slag was observed. Finally, it was observed that each element behaves in a different way from sample in sample but also from phase in phase.
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Integration of knowledge-based, qualitative and numeric tools for real time dynamic systems supervisionMeléndez i Frigola, Joaquim 27 February 1998 (has links)
The proposal presented in this thesis is to provide designers of knowledge based supervisory systems of dynamic systems with a framework to facilitate their tasks avoiding interface problems among tools, data flow and management.The approach is thought to be useful to both control and process engineers in assisting their tasks. The use of AI technologies to diagnose and perform control loops and, of course, assist process supervisory tasks such as fault detection and diagnose, are in the scope of this work. Special effort has been put in integrationof tools for assisting expert supervisory systems design. With this aim the experience of Computer Aided Control Systems Design (CACSD) frameworkshave been analysed and used to design a Computer Aided Supervisory Systems (CASSD) framework. In this sense, some basic facilities are required to be available in this proposed framework:· / ion Tools, for signal processing,representation and analysis to obtain significative information.· To deal with process variables, measures or numerical estimations, and expert observations, with uncertainty and imprecision.· Expert knowledge representation at different levels by using a rule-based system or simple qualitative relations.· Modularity and encapsulation of data and knowledge would be useful for structuring information.· Graphical user interface to manage all those facilities in the same environment as actual CACSD packages.Several tools from the AI domain have been added as Simulink ToolBoxes to deal with abstracted information, qualitative relationship and rule-based ES. Simple and intuitive qualitative relationship can be implemented by means of ablock-based qualitative representation language called ALCMEN. An ES shell, called CEES, has also been embedded into MATLAB/Simulink as a block toallow modularisation and partition of large expert KBs. Finally, the numeric to qualitative interfaces is performed by a set of algorithms, called abstraction tools, encapsulated also in Simulink blocks. The functionality of the wholeframework is able due to the use of object oriented approach in the development and implementation of those tools.In this thesis an attempt is undertaken to make steps towards integration of tools for expert supervision, including once for qualitative and symbolic data representation and management and symbolic knowledge processing. The main research objectives of this work include the following points :1. Incorporation of object-variables into classical numerical data processing system. The aim is to allow structural qualitative and symbolic knowledge representation. Complex information is encapsulated in a single source/sink structure, called object-variable, providing methods for knowledge access and processing.2. Implementation of selected particular tools for qualitative and symbolic knowledge representation and interfacing. Higher abstract level information processing based on the introduced object-variables.3. Embedding an object oriented rule-based expert system into a classical CACSD framework in order to provide high level knowledge processing facilities based on the domain of expert knowledge, heuristics, and logic.The object approach forces engineers to structure knowledge becoming highly locatable, modular and encapsulated. This features are very important to getexpert supervisory system design closer to process. The objective is to approach design tools to process engineers avoiding extra-time in learning application functionality and interfacing process variables and design tools. Thus, objects are used in the process variables descriptions as sources of information, encapsulating tools to provide significant (qualitative or numerical) information. Object oriented features will permit to divide large KBs into smaller ones to deal with complex systems adopting distributed solutions. Consequently, ES becomes more specialised, maintainable, and easier to validate.
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Approche multi-énergies associée à un détecteur spectrométrique rayons X pour l’identification de matériaux / Multi-energy methods for material identification using an X-ray spectrometric photon counting detectorBeldjoudi, Guillaume Nordine 19 September 2011 (has links)
Le développement des détecteurs de rayons X en comptage à base de semiconducteurs est en plein essor depuis une dizaine d’années, et des applications aussi bien dans le domaine médical que dans le domaine du contrôle non destructif sont envisagées. Ces détecteurs permettent en effet de réaliser des mesures à des énergies multiples en une seule acquisition, et ce avec une excellente séparation énergétique. Depuis les années 2008-2009, il semble qu’une véritable course se soit lancée pour le développement de détecteur permettant des mesures multi-énergies sur un nombre toujours plus nombreux de bandes d’énergies. Cependant, à ce jour, parmi l’ensemble des travaux qui ont été réalisés, l’intérêt de réaliser des mesures sur un grand nombre d’énergies n’a pas été démontré pour l’identification de matériaux. Dans le cadre d’une étude en sécurité, nous avons évalué l’intérêt lié à l’utilisation de détecteurs de rayons X en comptage permettant la réalisation de mesures sur plusieurs bandes d’énergies. Le domaine applicatif étudié concerne l’identification de matériaux dans les bagages des voyageurs. Nous avons tout d’abord développé une méthode originale d’identification de matériaux homogènes applicable à tout type de détecteur multi-énergies. Dans un premier temps, nous avons étudié, en simulation, l’évolution des performances d’identification de matériaux avec l’augmentation du nombre de bandes d’énergies de comptage. Un processus d’optimisation a été réalisé dans le but de déterminer, pour certaines configurations, une géométrie optimale des bandes d’énergies de comptage. Dans un second temps, les conséquences résultant de la prise en compte de la fonction de réponse du détecteur ont été quantifiées par la simulation de différents effets détecteurs (partage de charge, résolution en énergie). Une validation expérimentale a enfin pu être effectuée en utilisant un détecteur spectrométrique en comptage. À partir des mesures réalisées avec un tel détecteur, un regroupement des données nous a permis d’évaluer les performances d’identification de détecteurs possédant un nombre de bandes d’énergies de comptage différent. Enfin, nous avons mené une étude préliminaire sur la transposition à la tomographie multi-énergies de la méthode d’identification de matériaux homogènes développée initialement en radiographie. Cette modalité d’imagerie permet alors l’identification de matériaux superposés. / The development of X-ray photon counting detectors based on semiconductors has grown up over the last ten years, and applications in medicine, in security and in nondestructive testing are under study. These detectors make it possible to perform measurements at multiple energies in a single acquisition, with an excellent energetic separation. Since the years 2008-2009, it seems that a real race started for the development of detectors performing multi-energetic measurements on an increasing number of energy bands. However, today, within the works already done, the interest of performing measurements on a large number of energies has not been demonstrated for material identification. As part of a study in homeland security, we assessed the interest of using Xray counting detectors that perform measurements on multiple energy bands. The considered field of interest is material identification in the luggage of travelers. We first developed an original method for identifying single materials. This method is applicable to any type of multi-energy detector. In a first time, we studied in simulation the evolution of the performance for identifying materials with the increasing number of energy bands. An optimization process was carried out to determine, for certain configurations, an optimal geometry of the energy bands.In a second step, the consequences of taking into account the detector response function were quantified by simulating different sensors effects (charge sharing, energy resolution). An experimental validation has been performed by using a counting spectrometric detector. From the measurements experimentally obtained with such a detector, combining the data allowed us to evaluate the identification performance that would have detectors possessing a different number of energy bands. Finally, we conducted a preliminary study on the transposition of the identification method initially developed for radiography to the multi-energy computed tomography. This imaging modality allows to identify superimposed materials.
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Estudo da viabilidade técnica do processo de fabricação de espumas metálicas por reciclagem de cavacos da liga AA356 / Study of the technical viability of the fabrication process of metal foams by means of AA356 alloy machined chips recyclingRibeiro, Daniel Tadeu de Carvalho 08 November 2018 (has links)
Orientador: Maria Helena Robert / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica / Made available in DSpace on 2018-11-08T18:35:02Z (GMT). No. of bitstreams: 1
Ribeiro_DanielTadeudeCarvalho_M.pdf: 21302819 bytes, checksum: 8a7a0a9d878be3b8ccb6833173c35aef (MD5)
Previous issue date: 2011 / Resumo: Este trabalho tem como objetivo desenvolver um método alternativo para a fabricação de espumas metálicas pela reciclagem de cavacos de Al e a caracterização mecânico-metalúrgica do produto obtido. O processo investigado envolve a espumagem de compactados de misturas de cavacos e pó de agente espumante, com a espumagem ocorrendo na liga em estado semi-sólido tixotrópico. Foram fabricados precursores espumáveis pela mistura de cavacos da liga de Al AA356, com duas distintas granulometrias, a 1,5wt% do agente espumante TiH2 e posterior compressão também em duas distintas condições: compressão simples a frio e compressão dupla, a frio e a quente. Os elementos precursores foram aquecidos, sofrendo espumagem em estado semi-sólido, pela dissociação do agente espumante formando gás H2 no interior do metal. As espumas metálicas produzidas foram analisadas quanto à sua qualidade interna, arquitetura celular (dimensões, geometria de poros, espessura de paredes metálicas), propriedades físicas (densidade, teor de porosidade, condutividade e difusividade térmicas) e mecânicas em compressão semi-estática. O comportamento mecânico em compressão e o comportamento térmico das espumas produzidas foram também estimados teoricamente utilizando modelos da literatura. Os resultados obtidos mostraram que o processo proposto é eficaz para a produção de espumas de boa qualidade. Os melhores resultados são obtidos com o emprego de compactação dupla e espumagem direcional do precursor. Não foi possível observar influência das dimensões dos cavacos utilizados, na faixa de tamanhos empregada, nas características e propriedades das espumas produzidas. O comportamento das espumas metálicas sob compressão semi-estática demonstrou a formação de um platô de deformação plástica ascendente, o que indica uma grande capacidade de absorção de energia mecânica; todas as amostras apresentaram condutividade térmica bastante inferior e difusividade superior à do metal maciço, representando boas propriedades isolantes térmicas. Os valores de propriedades mecânicas estimadas teoricamente diferem dos obtidos experimentalmente, indicando necessidade de cuidado no emprego destes modelos / Abstract: This work aims to develop an alternative method for manufacturing metal foams by Al alloy machined chips recycling and mechanical and metallurgical characterization of the product. The process investigated involves foaming a compressed mixture of Al chips and foaming agent powder, with foaming occurring with the alloy in semi-solid thixotropic state. Foamable precursors were manufactured by mixing Al alloy A356 machined chips in two different particle sizes, to 1.5 wt% of the foaming agent TiH2 and its posterior compression also in two distinct conditions: simple cold compression and double compression, cold and hot. The precursors were heated, being foamed in semisolid state, by dissociation of the foaming agent generationg H2 into the bath. The internal quality, cellular architecture (pore size and geometry, cell wall thickness), physical properties (density, porosity level, thermal conductivity and thermal diffusivity) and mechanical behaviour under semi-static compression were analyzed for the metal foams produced. The mechanical behavior under compression and thermal behavior of the foams produced were also calculated using theorical models from literature. The results showed that the procedure proposed is effective for the production of foams of good quality. The best results are obtained foaming directionaly precursors manufactured by double compression. It was not possible to observe the influence of the dimensions of the machined chips, considering the size range adopted, on the characteristics and properties of the foams produced. The mechanical behavior of metallic foams under semi-static compression showed the formation of a ascendent plateau of plastic deformation, which indicates a great capacity of absorbing mechanical energy; all samples showed significantly lower thermal conductivity and diffusivity compared to the solid metal, what represents good thermal insulation properties. The theorical estimative of the sample's mechanical properties differ from those obtained experimentally, indicating that the matematical models proposed has to be used carefully / Mestrado / Materiais e Processos de Fabricação / Mestre em Engenharia Mecânica
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Problèmes de tournées de véhicules et application industrielle pour la réduction de l'empreinte écologique / Vehicule routing problems and industrial application to reduce the ecological footprintGuibadj, Rym Nesrine 16 April 2013 (has links)
Dans cette thèse, nous nous sommes intéressés à la résolution approchée de problèmes de tournées de véhicules. Nous avons exploité des travaux menés sur les graphes d'intervalles et des propriétés de dominance relatives aux tournées saturées pour traiter les problèmes de tournées sélectives plus efficacement. Des approches basées sur un algorithme d'optimisation par essaim particulaire et un algorithme mémétique ont été proposées. Les métaheuristiques développées font appel à un ensemble de techniques particulièrement efficaces telles que le découpage optimal, les opérateurs de croisement génétiques ainsi que des méthodes de recherches locales. Nous nous sommes intéressés également aux problèmes de tournées classiques avec fenêtres de temps. Différents prétraitements ont été introduits pour obtenir des bornes inférieures sur le nombre de véhicules. Ces prétraitements s'inspirent de méthodes issues de modèles de graphes, de problème d'ordonnancement et de problèmes de bin packing avec conflits. Nous avons montré également l'utilité des méthodes développées dans un contexte industriel à travers la réalisation d'un portail de services mobilité. / In this thesis, we focused on the development of heuristic approaches for solvingvehicle routing problems. We exploited researches conducted on interval graphsand dominance properties of saturated tours to deal more efficiently with selectivevehicle routing problems. An adaptation of a particle swarm optimization algorithmand a memetic algorithm is proposed. The metaheuristics that we developed arebased on effective techniques such as optimal split, genetic crossover operatorsand local searches. We are also interested in classical vehicle problems with timewindows. Various pre-processing methods are introduced to obtain lower boundson the number of vehicles. These methods are based on many approaches usinggraph models, scheduling problems and bin packing problems with conflicts. Wealso showed the effectiveness of the developed methods with an industrial applicationby implementing a portal of mobility services.
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[en] A ROBUST REAL-TIME COMPONENT FOR PERSONAL PROTECTIVE EQUIPMENT DETECTION IN AN INDUSTRIAL SETTING / [pt] UM COMPONENTE ROBUSTO EM TEMPO REAL PARA DETECÇÃO DE EQUIPAMENTOS DE PROTEÇÃO INDIVIDUAL EM UM AMBIENTE INDUSTRIALPEDRO HENRIQUE LOPES TORRES 19 July 2021 (has links)
[pt] Em grandes indústrias, como construção, metalúrgica e petróleo,
trabalhadores são continuamente expostos a vários tipos de perigos em
seus locais de trabalho. Segundo a Organização Internacional do Trabalho
(OIT), anualmente ocorrem cerca de 340 milhões de acidentes de trabalho.
Equipamentos de Proteção Individual (EPI) são utilizados para garantir
a proteção essencial da saúde e segurança dos trabalhadores. Com isto,
há um grande esforço para garantir que esses tipos de equipamentos sejam
usados de maneira adequada em ambientes de trabalho. Em tais ambientes, é
comum ter câmeras de circuito fechado de televisão (CFTV) para monitorar
os trabalhadores, pois essas podem ser usadas para verificar o uso adequado
de EPIs. Alguns trabalhos presentes na literatura abordam o problema de
verificação automática de EPIs usando imagens de CFTV como entrada;
no entanto, muitos destes trabalhos não conseguem lidar com a detecção
de uso seguro de múltiplos equipamentos e outros até mesmo pulam a fase
de verificação, fazendo apenas a detecção. Neste trabalho, propomos um
novo componente de análise de segurança cognitiva para um sistema de
monitoramento. Este componente atua para detectar o uso adequado de
EPIs em tempo real, usando fluxo de dados de câmeras de CFTV comuns.
Construímos este componente do sistema com base nas melhores técnicas
de Aprendizado Profundo voltadas para a tarefa de detecção de objetos. A
metodologia proposta é robusta com resultados consistentes e promissores
em termos da métrica Mean Average Precision (mAP) e pode atuar em
tempo real. / [en] In large industries, such as construction, metallurgy, and oil, workers
are continually exposed to various hazards in their workplace. Accordingly
to the International Labor Organization (ILO), there are 340 million occupational
accidents annually. Personal Protective Equipment (PPE) is used
to ensure the essential protection of workers health and safety. There is a
great effort to ensure that these types of equipment are used properly. In
such an environment, it is common to have closed-circuit television (CCTV)
cameras to monitor workers, as those can be used to verify the PPE s proper
usage. Some works address this problem using CCTV images; however, they
frequently can not deal with multiples safe equipment usage detection and
others even skip the verification phase, making only the detection. In this
paper, we propose a novel cognitive safety analysis component for a monitoring
system. This component acts to detect the proper usage of PPE s in
real-time using data stream from regular CCTV cameras. We built the system
component based on the top of state-of-art deep learning techniques for
object detection. The methodology is robust with consistent and promising
results for Mean Average Precision (mAP) and can act in real-time.
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Implementação industrial de um otimizador em tempo real. / Industrial implementation of a real time optimizer.Zanin, Antônio Carlos 18 April 2001 (has links)
Esta tese descreve o desenvolvimento e implementação de um otimizador em tempo real da operação do conversor da unidade de craqueamento catalítico em leito fluidizado (FCC) da refinaria Henrique Lage localizada em São José dos Campos. É desenvolvida uma estratégia de otimização integrada ao controlador preditivo cuja função objetivo e restrições incorporam componentes dinâmicos e estáticos. Os problemas de controle multivariável e otimização econômica são resolvidos simultaneamente num mesmo algoritmo. É utilizado um modelo rigoroso do processo para determinar as condições econômicas ótimas do estado estacionário do conversor. Por intermédio do modelo dinâmico, obtido através de testes em degrau na planta, é determinada a melhor trajetória para conduzir o processo para o seu ponto de maior lucratividade, sem violar as suas restrições operacionais durante as transições. As variáveis controladas e manipuladas possuem restrições tanto no transiente como no estado estacionário. O problema de otimização não linear resultante é resolvido através de um algoritmo SQP. A nova estratégia de otimização forneceu excelentes resultados nas simulações com as condições normais de operação e as perturbações típicas da unidade. Na comparação desta estratégia com a convencional, cujas funções de controle e otimização estão separadas, a mesma mostrou um melhor desempenho por manter o processo mais estável. Na fase de implementação do otimizador, o controlador preditivo multivariável existente no conversor foi adaptado para a nova estrutura de otimização através da inclusão das funções de otimização que envolvem o modelo rigoroso do estado estacionário do processo. O controlador/otimizador foi inserido no software da Petrobras denominado SICON, o qual já era utilizado como plataforma de sintonia e manutenção do controlador multivariável linear do conversor. Esse software tem facilidades para desenvolvimento e implementação de estratégias de controle avançado. Neste trabalho são apresentados os aspectos mais importantes da integração do otimizador na estrutura de automação da refinaria e o seu comissionamento. Estão também relacionadas as principais dificuldades encontradas na implementação do otimizador e a forma que as mesmas foram solucionadas. Os resultados obtidos na planta mostram um bom desempenho do novo algoritmo tanto em relação aos benefícios econômicos como na estabilização da unidade. / This thesis describes the development and implementation of a real time optimizer of the operation of a fluid catalytic cracking (FCC) converter in the Henrique Lage refinery located in São José dos Campos. It is developed an optimization strategy integrated into the predictive controller whose objective function and constraints incorporate dynamic and static components. The multivariable control and the economic optimization problems are solved simultaneously by the same algorithm. A rigorous process model is used to determine the converter steady-state optimum economic operating conditions. By utilizing a dynamic model, obtained through step tests in the plant, calculations are carried out in order to determine the best path to drive the process to its more profitable operating point, without violating operational constraints during the transient modes. All controlled and manipulated variables are constrained, both in the steady-state and in the dynamic states. The resulting optimization problem is nonlinear and is solved by an SQP algorithm. The new optimization strategy has provided excellent results in the simulations performed at normal operating conditions and typical disturbances. Comparing to the conventional strategy, whose control and optimization functions are separated, the new one has shown a better performance by maintaining a smoother operation of the process. In the optimizer implementation phase, the existent predictive linear controller was adapted to the new optimization structure by including the optimization function that involves the rigorous steady-state model of the process. The optimizing controller was inserted in Petrobras SICON software, which was already being used as a tuning and maintenance platform of the linear multivariable controller of the converter. This software has nice features for the development and implementation of advanced process control strategies. In this work it is presented the more important aspects of the optimizer integration into the refinery automation structure and its commissioning. The main difficulties of the optimizer implementation and the way how they were solved are also related. Plant results show a good performance of the new algorithm in terms of economic benefits and unit stabilization.
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Implementação industrial de um otimizador em tempo real. / Industrial implementation of a real time optimizer.Antônio Carlos Zanin 18 April 2001 (has links)
Esta tese descreve o desenvolvimento e implementação de um otimizador em tempo real da operação do conversor da unidade de craqueamento catalítico em leito fluidizado (FCC) da refinaria Henrique Lage localizada em São José dos Campos. É desenvolvida uma estratégia de otimização integrada ao controlador preditivo cuja função objetivo e restrições incorporam componentes dinâmicos e estáticos. Os problemas de controle multivariável e otimização econômica são resolvidos simultaneamente num mesmo algoritmo. É utilizado um modelo rigoroso do processo para determinar as condições econômicas ótimas do estado estacionário do conversor. Por intermédio do modelo dinâmico, obtido através de testes em degrau na planta, é determinada a melhor trajetória para conduzir o processo para o seu ponto de maior lucratividade, sem violar as suas restrições operacionais durante as transições. As variáveis controladas e manipuladas possuem restrições tanto no transiente como no estado estacionário. O problema de otimização não linear resultante é resolvido através de um algoritmo SQP. A nova estratégia de otimização forneceu excelentes resultados nas simulações com as condições normais de operação e as perturbações típicas da unidade. Na comparação desta estratégia com a convencional, cujas funções de controle e otimização estão separadas, a mesma mostrou um melhor desempenho por manter o processo mais estável. Na fase de implementação do otimizador, o controlador preditivo multivariável existente no conversor foi adaptado para a nova estrutura de otimização através da inclusão das funções de otimização que envolvem o modelo rigoroso do estado estacionário do processo. O controlador/otimizador foi inserido no software da Petrobras denominado SICON, o qual já era utilizado como plataforma de sintonia e manutenção do controlador multivariável linear do conversor. Esse software tem facilidades para desenvolvimento e implementação de estratégias de controle avançado. Neste trabalho são apresentados os aspectos mais importantes da integração do otimizador na estrutura de automação da refinaria e o seu comissionamento. Estão também relacionadas as principais dificuldades encontradas na implementação do otimizador e a forma que as mesmas foram solucionadas. Os resultados obtidos na planta mostram um bom desempenho do novo algoritmo tanto em relação aos benefícios econômicos como na estabilização da unidade. / This thesis describes the development and implementation of a real time optimizer of the operation of a fluid catalytic cracking (FCC) converter in the Henrique Lage refinery located in São José dos Campos. It is developed an optimization strategy integrated into the predictive controller whose objective function and constraints incorporate dynamic and static components. The multivariable control and the economic optimization problems are solved simultaneously by the same algorithm. A rigorous process model is used to determine the converter steady-state optimum economic operating conditions. By utilizing a dynamic model, obtained through step tests in the plant, calculations are carried out in order to determine the best path to drive the process to its more profitable operating point, without violating operational constraints during the transient modes. All controlled and manipulated variables are constrained, both in the steady-state and in the dynamic states. The resulting optimization problem is nonlinear and is solved by an SQP algorithm. The new optimization strategy has provided excellent results in the simulations performed at normal operating conditions and typical disturbances. Comparing to the conventional strategy, whose control and optimization functions are separated, the new one has shown a better performance by maintaining a smoother operation of the process. In the optimizer implementation phase, the existent predictive linear controller was adapted to the new optimization structure by including the optimization function that involves the rigorous steady-state model of the process. The optimizing controller was inserted in Petrobras SICON software, which was already being used as a tuning and maintenance platform of the linear multivariable controller of the converter. This software has nice features for the development and implementation of advanced process control strategies. In this work it is presented the more important aspects of the optimizer integration into the refinery automation structure and its commissioning. The main difficulties of the optimizer implementation and the way how they were solved are also related. Plant results show a good performance of the new algorithm in terms of economic benefits and unit stabilization.
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Wi-Fi 6E Performance Evaluation in Industrial Scenarios / Wi-Fi 6E Prestationsutvärdering i industriella scenarierRong, Wenqi January 2021 (has links)
As Industry 4.0 keeps approaching, the quality of data communication in industrial scenarios is increasingly important to support a high degree of automation and intelligence in factories. Wi-Fi 6E, the latest advanced wireless local-area network standard, comes with new 6 GHz unlicensed spectrum, a new access method named Orthogonal Frequency Division Multiple Access, and even more features. Accordingly, Wi-Fi 6E can be a promising candidate technology for an industrial wireless network. To fulfill industrial applications, Wi-Fi 6E is challenged with high communication requirements and a massive number of devices to support. Since the cutting-edge Wi- Fi 6E systems have not been widely deployed practically, simulations are required to evaluate the performance of Wi-Fi 6E in industrial scenarios. Based on an event-based simulator from Ericsson, we performed simulations covering not only single access point scenarios with periodic traffic, but also scenarios where multiple applications and generations of Wi-Fi systems coexist. Finally, a large-area industry scenario with frequency planning applied was evaluated. Through simulation results and analysis, we conclude that Wi-Fi 6E performs well in most of our tested scenarios. Compared to legacy Wi-Fi 5,Wi-Fi 6E performs better when subject to uplink traffic, and is more suitable for handling a massive number of devices or high packet rate traffic due to its unique multi-user accessing. However, Wi-Fi 6E can have poor performance when performing multi-user transmission with applications that have complex traffic and millisecond-level latency requirement. In some cases, Wi-Fi 6E performs worse than Wi-Fi 5 while handling multiple applications whose packet sizes vary a lot. Moreover, with the increase in factory scales, Wi-Fi 6E can have a magnificent performance drop, almost 100%, through the regulatory requirements in the new 6 GHz unlicensed band. / När Industri 4.0 fortsätter att närma sig blir datakommunikationens kvalitet i industriella scenarier allt viktigare för att stödja en hög grad av automatisering och intelligens i fabriker. Wi-Fi 6E, den senaste avancerade standarden för trådlöst lokalt nätverk, kommer med ett nytt 6 GHz olicensierat spektrum, en ny åtkomstmetod som heter Orthogonal Frequency Division Multiple Access och ännu fler funktioner. Följaktligen kan Wi-Fi 6E vara en lovande kandidatteknik för ett industriellt trådlöst nätverk. För att uppfylla industriella applikationer utmanas Wi-Fi 6E med höga kommunikationskrav och ett stort antal enheter att stödja. Eftersom de banbrytande Wi-Fi 6E systemen inte har använts i stor utsträckning praktiskt taget, krävs simuleringar för att utvärdera prestandan för Wi-Fi 6E i industriella scenarier. Baserat på en händelsebaserad simulator från Ericsson utförde vi simuleringar som inte bara omfattar enstaka åtkomstpunktsscenarier med periodisk trafik, utan också scenarier där flera applikationer och generationer av Wi-Fi-system samexisterar. Slutligen utvärderades ett storindustriscenario med tillämpad frekvensplanering. Genom simuleringsresultat och analys drar vi slutsatsen att Wi-Fi 6E fungerar bra i de flesta av våra testade scenarier. Jämfört med äldre Wi-Fi 5, fungerar Wi-Fi 6E bättre när den utsätts för upplänkstrafik och är mer lämpad för att hantera ett stort antal enheter eller hög pakettrafik på grund av dess unika åtkomst för flera användare. Wi-Fi 6E kan dock ha dålig prestanda vid överföring av fleranvändare med applikationer som har komplex trafik och krav på latens på millisekundnivå. I vissa fall fungerar Wi-Fi 6E sämre än Wi-Fi 5 när hanterar flera applikationer vars paketstorlekar varierar mycket. Med ökningen av fabriksskalor kan Wi-Fi 6E dessutom ha en fantastisk prestandaförlust, nästan 100%, genom lagkraven för det nya 6 GHz-bandet utan licens.
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Mise au point de mélanges collants écologiques à partir des écorces d’Acacia mollissima du Maroc / Elaboration of ecological adhesives from Moroccan bark of Acacia mollissimaRhazi, Naima 29 December 2015 (has links)
Cette étude présente une dimension économique, sociale et environnementale très importante. Elle rentre dans le cadre du projet Franco-Marocain PHC Toubkal (Ecopama, Volubilis 2012). Son objectif majeur est de valoriser les écorces Marocaine d’Acacia mollissima par une extraction verte permettant l’obtention des produits réactifs, des tanins condensés, qui seront utilisés dans le collage des panneaux de contreplaqués. Trois méthodes d’extraction ont été étudiées. Deux sont conventionnelles, une macération et une infusion ; ces deux techniques d’extraction sont simples, peu coûteuses. La troisième est une extraction assistée par micro-ondes ; c’est une technique innovante, rapide et peu consommatrice en solvant. La méthodologie des plans d’expériences est utilisée dans cette étude pour déterminer les facteurs les plus significatifs pour l’amélioration du rendement d’extraction des tanins condensés, optimiser les conditions d’extractions, réduire la proportion de solvant utilisé ainsi que le temps d’extraction. L’impact des conditions d’extraction et des méthodes d’extraction sur la teneur des tanins condensés sont étudiés pour la première fois pour les écorces d’Acacia mollissima du Maroc. Les extraits ont été caractérisés par des dosages colorimétriques, par des analyses structurales et thermiques. Les trois méthodes d’extraction ont été comparées. La teneur des extractibles est affectée par la proportion de solvant utilisé et le temps d’extraction. L’extraction assistée par micro-onde présente des teneurs en tanins condensés supérieure à l’extraction par des méthodes conventionnelles mais la teneur en sucre extraits est aussi élevée. Des formulations de colles à base de tanin et de lignosulfonate ont été élaborées en utilisant l’hexamine comme durcisseur. La colle biosourcée et ses constituants ont été caractérisés par analyse thermogravimétrique (ATG), et par calorimétrie différentielle à balayage (DSC). Les propriétés thermomécaniques et mécaniques des colles élaborées sont évaluées. L’optimisation des conditions de pressage des panneaux de contreplaqués, ainsi que le ratio tanin-lignosulfonate glyoxalé, ont été réalisées. La résistance des panneaux à l’eau froide et chaude est améliorée par l’addition de la résine époxy aux formulations de colle. Les propriétés mécaniques des panneaux de contreplaqués encollés ont été évalués par des tests normatifs et ont été comparés à celle des résines synthétiques commerciales (urée formaldéhyde et phénol formaldéhyde). La qualité de collage des panneaux élaborés a été évaluée. Les différentes colles présentent des caractéristiques physiques et thermiques satisfaisantes et acceptables pour les industries de collage des panneaux de bois. Des panneaux de contreplaqués avec de bonnes performances mécaniques et une excellente résistance à l’eau froide et bouillante ont été fabriqués. Ces colles présentent une qualité de collage qui se rapproche de celle des résines phénol-formaldéhyde, et peuvent être utilisées avec succès, pour une application industrielle des panneaux de contreplaqués, en milieu sec, humide et extérieur. / This study has an important economical, social and environmental dimension. It was conducted within the framework Franco-Moroccan PHC Toubkal "Ecopama, Volubilis 2012". The desire to enhance Moroccan bark of Acacia mollissima by the use of green extraction and also to obtain reagent products, condensed tannins, was the main objective of this study. These tannins will be used in the bonding of plywood panels. Three extraction methods were studied. Two are conventional, maceration and infusion; witch is simple and cheap extraction method. The third is microwave assisted extraction which is a fast, innovative method using a small amount of solvent. The experimental design methodology was used to identify the significant factors to improve yield extraction of condensed tannins, to optimize extraction process, to reduce solvent proportion and time extraction. The impact of extraction conditions and extraction process were studied for the first time on condensed tannins contents extracted from Moroccan bark of Acacia mollissima. The extracts were characterized using colorimetric assays, structural and thermal analysis.The three types of extraction were compared. The extractibles contents were affected by solvent proportion and also time extraction. Microwave assisted extraction produced a higher condensed tannins than the conventional method but in the other hand the sugars extracted is more important. Tannin-lignosulfonate adhesives were produced using hexamine as a hardener. The biobased adhesive formulations and their compounds were compared using thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) and by determining the thermal and mechanical proprieties of the adhesives. Optimal tannin-glyoxalated lignosulfonates ratio and pressing conditions of plywood panels were measured. The resistance of plywood panels to the cold and hot water was improved by the addition of epoxy resin in adhesive formulations. Mechanical properties of plywood panels made with tannin-lignosulfonates-epoxy adhesives were evaluated using normative standard and compared to those of panels made with a commercial resins (urea formaldehyde and phenol formaldehyde). The bonding quality of plywood panels elaborated was evaluated. The various adhesives elaborated have satisfactory and acceptable physical and thermal characteristics for bonding panels used in wood industries. Plywood panels with good mechanical performance, good resistance to cold water and to boiling water, were produced. The bonding quality of the adhesives elaborated in laboratory scale presented approximate proprieties than the phenol-formaldehyde resins which can use with successfully in dry, wet and exterior industrial application of plywood panels.
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