Two application applications of Fuzzy Logic to improve the performance of two controllers are presented. The first application takes a Sliding Mode Controller designed for chemical process to reject disturbances. A fuzzy element is added to the sliding surface to improve the controller performance when set point change affects the control loop; especially for process showing highly nonlinear behavior. This fuzzy element, , is calculated by means of a set of fuzzy rules designed based on expert knowledge and experience. The addition of improved the controller response because accelerate or smooth the controller as the control loop requires. The Fuzzy Sliding Mode Controller (FSMCr) is a completely general controller. The FSMCr was tested with two models of nonlinear process: mixing tank and neutralization reactor. In both cases the FSMCr improves the performance shown for other control strategies, as the industrial PID, the conventional Sliding Mode Control and the Stan dard Fuzzy Logic Controller. The second part of this research presents a new way to implement the Dynamic Matrix Control Algorithm (DMC). A Parametric structure of DMC (PDMC) control algorithm is proposed, allowing to the controller to adapt to process nonlinearities. For a standard DMC a process model is used to calculate de controller response. This model is a matrix calculated from the dynamic response of the process at open loop. In this case the process parameters are imbibed into the matrix. The parametric structure isolates the process parameters allowing adjust the model as the nonlinear process changes its behavior. A Fuzzy supervisor was developed to detect changes in the process and send taht [sic]information to the PDMCr. The modeling error and other parameters related were used to estimate those changes. Some equations were developed to calculate the PDMCr tuning parameter,lambda, as a function of the process parameters. The performance of PDMCr was tested using to model of nonlinear process and compare with the standard DMC; in most the cases PDMCr presents less oscillations and tracks with less error the set point. Both control strategies presented in this research can be implemented into industrial applications easily.

When cylinders for motor saws are manufactured there are high demands on the cylinders strength and wearing qualities. Aluminum is a material with low density and is used by Husqvarna AB for their motor saw cylinders. The aluminum is strengthening with nickel that is attached to the cylinders through electrolysis. When aluminum is in contact with oxygen a film of oxide is formed. To eliminate the oxide and to prevent formation of new oxide zinc is used. The cylinders are dipped into a bath of zinc before they pass on to a pre-nickel process, which purpose is to remove the excess of zinc so the “real” nickel process won’t be contaminated. In the process there is a selective bath where zinc is precipitated on sheet-metals through electrolysis. The problem is that while zinc is precipitated so is nickel and in a much greater extend, about 1 % zinc and 99 % nickel. Husqvarna AB needs a technique to increase precipitation of zinc and reduce the precipitation of nickel. A small copy of the selective bath was constructed where adjustments of different parameters were possible. In the bath there was an anode of nickel, a cathode, process liquid, a pump for stirring and a plant installation from an aquarium for the temperature. In the bath different voltages, distance between anode – cathode and different sheets of metal were tested. Every test were in progress for about three days and then pieces of sheet-metals were cut and sent for analysis of zinc/nickel percentage. A couple of the tested sheet-metals didn’t work and the ones that did work showed no special difference in zinc/nickel percentage. An increase in distance between the anode and cathode showed a small difference but not much. The alteration that showed to be most effective was to decrease the voltage. The normal voltage is 2, 8 V but when it was decreased to 2, 0 V it gave a much better result. The layer on the sheet-metal showed to contain 12 % zinc and 88 % nickel. A couple of other tests were performed with decreased voltage but no one gave as good result as 2, 0 V. If Husqvarna AB shall be able to use a lower voltage they need a greater cathode surface then they have today. That is because of the lower reaction rate. The lower reaction rate conducts an increasing amount of zinc in the bath and an electrolysis that doesn’t work completely. Other methods for precipitation could have been tested e.g. change of anode, precipitation of zinc as a salt or a powder that could have been filtrated or a process that reduces the excess of zinc. To test any of these methods big changes in the process structure would be needed which costs both time and money. The authors therefore concluded that the best thing for Husqvarna AB to do is to increase the cathode surface by connecting another bath next to the existent. / Vid tillverkning av motorsågscylindrar ställs det höga krav på att de är tåliga och slitstarka. På Husqvarna AB tillverkas motorsågscylindrar av aluminium som är ett material med låg densitet. Aluminiumet förstärks med nickel som genom elektrolys fästs på cylindrarna. På aluminium bildas ett oxidskikt i kontakt med syre och för att eliminera skiktet samt undvika bildning av ny oxid så doppas cylindrarna i zink innan elektrolysen. Cylindrarna doppas hela i ett zinkatbad innan de går vidare till en förförnicklingsprocess som bland annat är till för att bli av med överflödigt zink så att det inte förorenar det ”riktiga” nickelbadet. I processen finns ett selektivt bad där zink fälls ut genom elektrolys på plåtar. Problemet är att samtidigt som zink fälls ut så fälls också nickel ut och i större mängd, ca 1 % zink respektive 99 % nickel. Husqvarna AB behöver en teknik som ökar utfällning av zink samtidigt som nickelutfällning reduceras. En liten kopia konstruerades av det selektiva badet där justering av olika parametrar kunde utföras. I badet användes en plåtkatod och en nickelanod, vätska från processen, en pump för omrörning och ett akvarieaggregat för värme. I testbaljan provades ändringar av spänning, avstånd anod – katod och olika material som katod. Varje bad kördes ca tre dagar och sedan klipptes bitar av plåtarna bort och skickades iväg för analys av zink/nickelhalt. Det visade sig att ett par av de testade plåtarna inte fungerade och de som fungerade visade ingen större skillnad i zink/nickelhalt. En ökning av avstånd mellan katod och anod gav en liten procentskillnad men inte tillräcklig. Den parameterändring som visade sig vara mest effektiv var att sänka spänningen. Normalt ligger spänningen på 2,8 V men när den sänktes till 2,0 V gav det bättre resultat. Skiktet på plåten visade sig nu innehålla ca 12 % zink och 88 % nickel. Ytterligare försök gjordes med lägre spänning men ingen gav lika bra resultat som 2,0 V. För att Husqvarna AB ska kunna använda lägre spänning kräver det en ökad katodyta än vad som finns i dagsläget, på grund av en lägre reaktionshastighet. Lägre reaktionshastighet leder till en för snabb ökning av zink i badet och en dåligt fungerande elektrolys. Andra metoder för utfällning hade kunnat provats t ex byte av anod, fälla ut zink som ett salt eller pulver som sedan filtrerats bort eller en process för att minska överflödet av zink. Alla dessa metoder kräver att Husqvarna AB gör en omfattande omstrukturering av processen vilket kräver både tid och pengar. Därför kom författarna fram till att en ökad katodyta i form av ett nytt bad anslutet till det gamla vore den bästa lösningen för Husqvarna AB.

Process intensification tools, such as the capillary reactor, offer several benefits to the chemical process industries due to the well-defined high specific interfacial area available for heat and mass transfer, which increases the transfer rates, and due to low inventories, they also enhance the safety of the process. This has provided motivation to investigate three such tools, namely the capillary microreactor, spinning disc and rotating tube reactors, in this study. / The gas-liquid slug flow capillary microreactor intensifies reactor performance through internal circulation caused by the shear between the continuous phase/wall surface and the slug axis, which enhances the diffusivity and consequently increases the reaction rates. However, integrating the complex hydrodynamics of this reactor with its chemical kinetics is a mathematically challenging task. Therefore, in this study, a simple-to-complex approach, using a set of state-of-the-art computational fluid dynamic tools, has been used. Firstly, simulations were performed without any chemical reaction to ascertain the extent of slug flow regime. The model also clearly captured the slug flow generation mechanism which can be used to structurally optimize the angle of entry in these reactors. Finally, the hydrodynamic model was also capable of estimating the pressure drop and slug lengths. After successfully simulating the hydrodynamics of the system, a reaction model was incorporated to study the chemical reaction kinetics. The results were compared with the published experimental work and were found to be in good agreement. / The spinning disc reactor utilizes the centrifugal and shear forces to generate thin liquid films characterized with intense interfering waves. This enables a very high heat transfer coefficients to be realized between the disc and liquid, as well as very high mass transfer between the liquid and the bulk gas phase. The waves formed also produce an intense local mixing with very little back mixing. This makes a spinning disc reactor an ideal contactor for multiphase processes. The focus of this study has been to elucidate the hydrodynamic behaviour of the liquid film flow over the horizontal spinning disc. Investigations were also performed to elaborate the local and overall hydrodynamic characteristics of a fully developed spinning disc reactor. Simulation results showed a continuous linear liquid film on the horizontal spinning disc and intense mixing performance in the annulus of the reactor around the disc surface. Finally, the film thickness data from the simulations were compared with the limited amount of data available for this novel process. / Rotating tube reactor also uses centrifugal forces to generate the liquid film and a high degree of mixing along with an improved control over the reactant retention times. In this work we have conducted a CFD analysis to understand the hydrodynamics of this new technology for future developments.

Thesis (Ph.D.)--McMaster University, 2002. / Adviser: P.A. Taylor and John F. MacGregor. Includes bibliographical references. Also available via World Wide Web.

Thesis (Ph.D.)--McMaster University, 2002. / Adviser: P.A. Taylor and John F. MacGregor. Includes bibliographical references. Also available via World Wide Web.

Orientadores: Flávio Vasconcelos da Silva, Ana Maria Frattini Fileti / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Química / Made available in DSpace on 2018-08-16T18:45:23Z (GMT). No. of bitstreams: 1 Costa_ThiagoVazda_M.pdf: 15859888 bytes, checksum: 391c96e4f2ff3598497e8840686f8166 (MD5) Previous issue date: 2010 / Resumo: Uma malha de controle com baixo desempenho implica em um aumento dos custos de produção, causando descarte de produto fora da especificação e desgaste desnecessário dos elementos finais de controle. A depender do processo controlado, uma malha deficiente pode também acarretar em paradas não previstas na planta e até mesmo em danos ao meio ambiente. Diante do exposto, o controle preditivo baseado em modelos (MPC) é um dos poucos algoritmos comprovadamente capazes de estabilizar processos na presença de não-linearidades e restrições. Para atender aos seus objetivos de controle, o algoritmo clássico MPC utiliza um procedimento de otimização baseado no modelo linear da planta. Contudo, o afastamento da região de projeto do modelo linear resulta na perda de sua efetividade e consequente do controlador que o utiliza. Deste modo, objetivou-se a partir de uma descrição não-linear do sistema a melhoria do desempenho do controlador. Os objetivos específicos dessa dissertação foram o estudo e análise de um controlador GPC (generalized predictive controller) operando em paralelo com uma rede de modelos lineares locais, identificada por meio do algoritmo LOLIMOT (local linear model trees), capaz de adequar o modelo de predição do controlador para a faixa de operação atual do processo. Para a avaliação e análise da qualidade do controlador proposto foi montado um aparato experimental para controle de pH. A estratégia de controle foi implementada em um sistema em código aberto para monitoramento e controle do processo. Portanto, considerando a característica estática não-linear do processo foram realizados estudos comparativos entre o GPC tradicional (baseado em um único modelo linear) e a abordagem proposta. Os resultados mostraram que a rede foi capaz de representar satisfatoriamente a saída do sistema, resultando em uma estrutura simples, com modelos locais na forma de estruturas ARX. Também foi demonstrado que o GPC utilizando a rede de modelos lineares locais desempenhou de forma satisfatória e até mesmo superior ao GPC tradicional.Observou-se que a saída calculada pelo controlador proposto foi consideravelmente menos agressiva que o controlador tradicional, levando a uma considerável diminuição do esforço de controle empregado ao sistema. Os resultados obtidos demonstraram que houve uma economia de até 45% no esforço de controle. Observou-se ainda que o sistema desenvolvido é conveniente para aplicações reais, já que a estratégia de controle preditivo concebida em Scilab obteve sucesso na solução do problema de controle dentro do intervalo de amostragem inclusive quando incorporado o problema QP (programação quadrática) com restrições. Tendo em vista que a estrutura destes sistemas permite que sejam utilizados nas mesmas aplicações destinadas a modelos lineares, comprovou-se também a viabilidade e aplicabilidade do uso das redes de modelos lineares locais diretamente em algoritmos de controle avançado já disponíveis para indústria, como nos controladores GPC / Abstract: Low performance control loops imply in higher production costs, leading to off-specification production loss and unnecessary wear of the final control elements. Depending on the controlled process, the deficient loop can also lead to non-expected plant stops and even on environment damage. In this sense, model predictive control (MPC) is one of the few algorithms proved capable to stabilize processes in the presence of nonlinearities and constraints. To meet its control objectives, the classic MPC algorithm is based on an optimization problem which relies in the system's linear model. Although, the removal of the linear model from its designed condition deteriorates the model's and controller's effectiveness. Hence, the general objective of the presented work relies in the non-linear description of the system for improving the control performance. The main objectives were the study and analysis of a generalized predictive controller (GPC) operating in parallel with a linear local model network, identified by the LOLIMOT algorithm, able to adequate the controller's prediction model for the process operation range. For the quality assessment of the proposed controller, tests were evaluated in an experimental apparatus for pH control. The control strategy was implemented in an open source system for monitoring and control. Therefore, considering the static nonlinear characteristics of the process, comparative studies were applied between the traditional GPC (based on an single global model) and the proposed approach. The results showed that the dynamic network was able to effectively represent the system output, resulting in a simple structure, given the fact that the local models are indeed local ARX models. It was also shown that the GPC using the linear local model network performed satisfactorily and even better than the single model GPC. It was observed that the output calculated by the proposed controller has been considerably less aggressive than the traditional controller, leading to a considerable reduction in the system's control effort. The results showed that there was a saving up to 45% in the control effort. It was also observed that the developed monitoring and control system is suitable for real applications, since the predictive control strategy, implemented in Scilab, succeeded in solving the control problem within the sampling time even with the embedded constrained QP (quadratic programming) problem. Considering that the structure of these systems allows them to be used in similar applications to linear models, it was also proved the viability and applicability of using the linear local models network directly into advanced control algorithms already available to industry as in the GPC controllers / Mestrado / Sistemas de Processos Quimicos e Informatica / Mestre em Engenharia Química

Orientadores: Rubens Maciel Filho, André Luiz Jardini Munhoz / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Química / Made available in DSpace on 2018-08-22T16:44:29Z (GMT). No. of bitstreams: 1 Bineli_AulusRobertoRomao_D.pdf: 8294042 bytes, checksum: a3a2a14af42175c483a90d29b0102664 (MD5) Previous issue date: 2013 / Resumo: Atualmente, o conceito de sustentabilidade vem ganhando cada vez mais espaço e com ele os desafios de melhorar cada vez mais os processos industriais. Assim, tanto as engenharias quanto as ciências de base têm se dedicado à integração do conhecimento para projetar e implementar soluções inovadoras e ambientalmente equilibradas. Neste contexto, o uso dos microrreatores surge como uma opção atraente e com potencial para atender às diversas e crescentes exigências ambientais e econômicas. Portanto, o principal objetivo desta tese foi projetar fabricar e testar um microrreator catalítico para produção de hidrogênio a partir da reforma a vapor do etanol. Para o cumprimento deste objetivo, quatro etapas principais foram desenvolvidas. A primeira delas foi à realização de estudos fluidodinâmicos do microrreator para a escolha da geometria mais favorável à distribuição do fluxo entre os microcanais. Nesta etapa foi possível quantificar o fluxo do gás nos microcanais e escolher a geometria com o menor valor no desvio padrão relativo. Na segunda etapa, a tecnologia de manufatura aditiva de sinterização direta em metal a laser (DMLS) foi avaliada para a fabricação dos componentes do microrreator mostrando um grande potencial, principalmente por oferecer condições para produção de superfícies porosas. Apesar disso, as peças assim obtidas apresentaram distorções notáveis devido à alta energia do laser, sendo necessários mais estudos dos parâmetros de fabricação a fim de se obter peças com boa qualidade. Por essa razão e para garantir uma boa integração entre os componentes, a estrutura de compartimento do microrreator e as placas de microcanais foram obtidas por métodos convencionais de usinagem e corrosão química. Na terceira etapa, um método de otimização multicritério foi descrito para se investigar e sugerir uma faixa de parâmetros operacionais do microrreator como temperatura, fração de massa de etanol e fluxo volumétrico de alimentação. Nesta fase, entre os três modelos cinéticos selecionados, apenas um foi considerado o mais confiável para se estender o estudo de otimização e assim sugerir uma faixa de operação do microrreator. Na etapa final, testes experimentais da reação de reforma a vapor do etanol foram conduzidos sob duas diferentes composições de catalisadores, Ni/Al2O3 e Ni/CeO2, com o objetivo de se conhecer as principais reações. Os resultados mostraram que a desidratação e decomposição do etanol foram predominantes em ambos catalisadores, porém foi observada a supressão da desidratação em temperatura de 500 e 600ºC. Entre os catalisadores estudados o Ni/CeO2 foi o mais seletivo e promissor, pois foi capaz não somente de suprimir as reações indesejadas, como a formação de coque, mas por fornecer alta produtividade e rendimento comparado com o Ni/Al2O3. Além disso, ficou demonstrado que o projeto do microrreator proposto foi capaz de produzir hidrogênio com rendimentos significativos, próximo a 100% em altos tempos de residência, sendo, portanto, uma boa opção a ser considerada tanto para aplicações em pequena quanto em grande escala / Abstract: Currently, the concept of sustainability is gaining more prominence and with it the challenges to improve industrial processes. Thus, both engineering as the basic sciences has been devoted to integrate knowledge to design and implement innovative and environmentally balanced solutions. In this context, the use of microreactors emerges as an attractive option and with potential to meet various environmental and economic requirements. Therefore, the objective of this thesis was to design, fabricate and test a catalytic microreactor for hydrogen production from ethanol steam reforming. To achieve this objective, four main steps were developed. Firstly, studies of the fluid dynamic behavior of microreactor were conducted for choosing the most favorable geometry to flow distribution among microchannels. At this point it was possible to quantify the internal gas flow in the microchannels and to select the geometry with the lowest value in the relative standard deviation. In the second step, the additive manufacturing technology of Direct Metal Laser Sintering (DMLS) was evaluated to fabricate the microreactor components. This technology showed a great potential, especially to provide conditions to produce pieces with porous surfaces. Nevertheless, the pieces obtained by this process showed remarkable distortions due to the high laser energy, necessitating further study about fabrication parameters in order to improve the quality of the parts. For that reason and also to ensure good integration among the components, the housing structure and microchannel plates were obtained by conventional methods of milling cutter and wet chemical etching, respectively. In the third step, a multicriteria optimization method was described to investigate and suggest a range of operating parameters such as temperature, ethanol mass fraction and volumetric flow. Among the three kinetic models selected, only one was considered the most reliable to extend the study of optimization and thus to suggest a range of operation conditions of the microreactor. In the final step, experimental tests of ethanol steam reforming were conducted under two different compositions of catalysts, Ni/Al2O3 and Ni/CeO2, with the aim of knowing the main reactions. The results showed that the ethanol dehydration and decomposition were predominant in both catalysts, but the suppression of the dehydration in the temperatures of 500 to 600°C was observed. Also, among the catalysts studied, the Ni/CeO2 was the most promising not only because it was able to suppress the undesired reactions, but also to provide a high productivity and yield compared to the Ni/Al2O3. Furthermore, it was shown that the design of microreactor was able to produce hydrogen with significant yields, close to 100% at high residence times, and is therefore a good option to be considered in applications ranging from small to large scales / Doutorado / Desenvolvimento de Processos Químicos / Doutor em Engenharia Química

Orientador: Roger Josef Zemp / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Química / Made available in DSpace on 2018-08-23T09:46:30Z (GMT). No. of bitstreams: 1 Santos_RaphaelRibeiroCruz_M.pdf: 3339099 bytes, checksum: 221059e3eab5645623f894afee5431de (MD5) Previous issue date: 2013 / Resumo: Neste trabalho é apresentada uma metodologia de desenvolvimento de um sistema supervisório utilizando Microsoft Excel®. O sistema foi desenvolvido para operar uma planta de polimerização em solução de estireno. A aplicação de códigos computacionais na em VBA (Visual Basic for Applications) na planilha torna possível a criação de um cliente OPC para comunicação entre o computador e hardware. A planilha possui, portanto condições de receber, enviar, armazenar e tratar informações vindas do processo. A polimerização de estireno é realizada utilizando tolueno como solvente e BPO (Peroxido de Benzoíla) como iniciador. Aquisição da temperatura do reator, temperatura de entrada e saída da camisa e massa especifica do meio reacional foram realizada. A partir dos dados experimentais extraídos da reação de polimerização, foi gerado um modelo empírico utilizando Redes Neurais Artificiais (RNA). As RNAs são implementadas no Excel de forma simples, usando a própria planilha, por operar matrizes, tornando-se oportunas para o desenvolvimento de controladores preditivos. O Microsoft Excel® mostrou-se uma interessante ferramenta para aplicação em automação de protótipos experimentais / Abstract: This research work presents a methodology for the development of a supervisory system using Microsoft Excel®. The system was designed to operate a styrene polymerization plant. The development of computational codes in VBA (Visual Basic for Applications) allows for the creation of an OPC client for communication between computer and hardware. The spreadsheet has porting is able to receive, send, store and process information from the process. The polymerization of styrene is carried out using toluene as solvent and BPO (benzoyl peroxide) as an initiator. Acquisition of reactor temperature, inlet temperature and outlet shirt and specific mass of the reaction medium were performed. From the experimental data extracted from the polymerization reaction, an empirical model was generated using Artificial Neural Networks (RNA). RNAs are easily implemented in Excel simply, using operations arrays, making it appropriate for the development of predictive controllers. The use of Microsoft Excel® proved to be an interesting tool for application in automation experimental prototypes / Mestrado / Engenharia Química / Mestre em Engenharia Química

Orientador: Flávio Vasconcelos da Silva / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Química / Made available in DSpace on 2018-08-23T22:24:17Z (GMT). No. of bitstreams: 1 Fonseca_RodolphoRodrigues_M.pdf: 9175458 bytes, checksum: f2dde4cc9ff6948eb7de39f51a322a4a (MD5) Previous issue date: 2013 / Resumo: Devido ao aumento da demanda nacional e mundial por combustíveis renováveis e novas tecnologias para melhoria de seus processos, é inegável a importância do desenvolvimento de novos controladores que possam garantir o funcionamento adequado destes sistemas. Neste contexto, este trabalho focou no desenvolvimento de um tipo de controlador não convencional baseado em inteligência artificial (Lógica Fuzzy) associado a uma estratégia Split-range para a manutenção da temperatura de reação de transesterificação do óleo de soja. Os ensaios foram conduzidos em um reator batelada totalmente instrumentado, monitorado e controlado via SCADA (Supervisory Control And Data Acquisition). Verificou-se que a melhor estratégia proposta para os sistemas de controle Fuzzy - Split-range na regulação da temperatura do reator foi a que empregou 147 regras sem a mistura de utilidades na jaqueta do reator, obtendo rápida estabilização da temperatura do reator, aproximadamente 15 minutos, e menor esforço de controle quando comparado às demais estratégias testadas. Como ferramentas de análise comparativa do sistema de controle foram utilizados os critérios de desempenho IAE, ISE e ITAE, além dos esforços de controle requeridos pelas válvulas durante os ensaios. Os resultados mostraram que a combinação Fuzzy - Split-range é viável no controle de temperatura, podendo ser estendida a demais processos industriais. / Abstract: In fact of national and international demand increasing for renewable fuels as biodiesel and also new technologies for process enhancement, it is worthy of attention the development of new controllers that guarantee adequate biodiesel production process control. In this context, this work applied the design of a non-conventional controller based on artificial intelligence (Fuzzy Logic) associated with Split-range strategy to regulate the temperature of soybean oil transesterification. The tests were conducted in a instrumented batch reactor, monitored and controlled by a SCADA (Supervisory Control And Data Acquisition) system. For the studied process control, the best combination set among the Fuzzy - Split-range strategies for the reactor's temperature control applied 147 set rules and no mixture of utilities in reactor's jacket. With fast temperature estabilization in almost 15 min, less control effort was required by the system among the strategies testeds. Performance criterions as IAE, ISE and ITAE were used to support comparative analysis, either control efforts by valves were used. The results show that Fuzzy - Split-range strategy is viable in biodiesel batch reactor temperature control, promising to application in others chemical processes. / Mestrado / Sistemas de Processos Quimicos e Informatica / Mestre em Engenharia Química

Orientador: Ana Maria Frattini Fileti / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Química / Made available in DSpace on 2018-08-21T17:10:58Z (GMT). No. of bitstreams: 1 VidalSantos_SauloFernandodos_M.pdf: 3908407 bytes, checksum: 8f5bba56950cb6628faf5b13df5bea0e (MD5) Previous issue date: 2012 / Resumo: Na maioria das indústrias químicas se faz necessário a refrigeração de equipamentos, produtos, processos, ambientes, etc. A grande desvantagem dos sistemas de refrigeração empregados nesses processos está no gasto energético envolvido, que pode representar 70% do gasto total de uma planta. Visando minimizar esses gastos, exaustivos trabalhos de pesquisa vem sendo desenvolvidos neste campo. No Laboratório de Controle e Automação de Processos da Faculdade de Engenharia Química da Unicamp, há um protótipo de um chiller utilizado em pesquisas de técnicas de modelagem e controle visando reduzir o gasto energético empregado nos sistemas de refrigeração. Com o intuito de facilitar estes estudos, este trabalho desenvolveu um modelo a partir dos simuladores comerciais ASPEN PLUS'MARCA REGISTRADA' e ASPEN DYNAMICS'MARCA REGISTRADA' capaz de representar o protótipo experimental citado. Para validação do modelo, foram utilizados dados obtidos da própria planta experimental, em diferentes condições de processo, garantindo a funcionalidade do modelo para situações diversas de funcionamento do equipamento. Uma vez validado, o modelo desenvolvido foi utilizado no estudo dinâmico do processo de refrigeração. Também foram verificadas estratégias de controle clássico e sua aplicabilidade nos sistema em questão. Está presente no trabalho o detalhamento das variáveis e parâmetros que foram utilizados na configuração, no ASPEN PLUS'MARCA REGISTRADA', dos blocos representativos dos equipamentos. Todas as formas de controle PID sugeridas se adaptaram bem ao processo, mas apenas no ponto de operação para qual o controle foi sintonizado, ou seja, para cada ponto de operação, uma nova sintonia deve ser realizada / Abstract: Refrigeration systems are required in most chemical industries in order to maintain the temperature in process equipments, production line, air-conditioned environments or rooms, etc. The main drawback of the refrigeration systems is the great expense of energy, which can represent up to 70% of the energy expenditure of the global plant. Aiming to minimize these costs, several scientific works have been developed in this field. In the Automation and Process Control Laboratory at FEQ/UNICAMP, there is a chiller prototype used in technical research on modeling and control strategies to save energy in refrigeration systems. In order to facilitate these studies, in this work it was developed a model, based on commercial simulators such as ASPEN PLUS 'TRADE MARK' and ASPEN DYNAMICS'TRADE MARK', capable of representing the experimental prototype. To validate the model, data obtained from the experimental plant, under different process conditions was used, ensuring the functionality of the model for different operating conditions. After validated, the model was used to the dynamic cooling process study. Classical control strategies were applied and their applicability in the cooling system was analyzed. This work contains details on the configuration of variables and parameters used in the equipment simulation blocks from ASPEN PLUS'TRADE MARK'. All proposed strategies of PID control showed to be well adapted to the process, but only at the operating point for which control was tuned. To summarize, for each operating point a new controller tuning must be carried out / Mestrado / Sistemas de Processos Quimicos e Informatica / Mestre em Engenharia Química