Dissertations / Theses on the topic 'Process Control and Simulation'
To see the other types of publications on this topic, follow the link: Process Control and Simulation.
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 dissertations / theses for your research on the topic 'Process Control and Simulation.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
1
Sneesby, Martin G. "Simulation and control of reactive distillation." Thesis, Curtin University, 1998. http://hdl.handle.net/20.500.11937/2555.
Full textAbstract:
Reactive distillation has enormous potential for the economical synthesis of tertiary ethers. Methyl tert-butyl ether (MTBE) has been commercially produced with this technology since the early 1980s and it appears that the process also has application for Ethyl tert-butyl ether (ETBE) and other ethers. However, the combination of reaction and distillation in a single unit operation produces a process complexity that inhibits expeditious design and tight control, and presents a technology risk for potential developers. This particularly applies to hybrid reactive distillation where both reactive and non-reactive column sections are employed.The steady state simulation of a series of reactive distillation columns and processes for the production of ETBE and MTBE illuminated a number of important issues related to the optimal design techniques. Many of these issues are peculiar to reactive distillation and would not reasonably be anticipated without a priori knowledge of the phenomena involved. For example, the addition of theoretical equilibrium stages and an increase in the reflux ratio do not always have a directionally equivalent effect. The trade-off between energy consumption and capital cost which is the basis for most distillation designs cannot always be applied to reactive distillation. Importantly, the use of standard modelling techniques for equilibrium processes was also validated for reactive distillation design.The use of residue curve diagrams and reactive residue curve diagrams for the design of reactive distillation processes was investigated and shown to provide useful information regarding the feasibility of reaction-separations. Combined with simulation tools (e.g. Pro/II and SpeedUp), these techniques form the basis of a proposed design strategy for hybrid reactive distillation. It is important to apply these design tools appropriately and to select the correct process for a given application. The optimal design must also consider economics and the relative values of products, reactants and energy. These issues were studied with respect to ETBE production for gasoline oxygenation.The complexity of hybrid reactive distillation not only presents design challenges but potentially makes the process more difficult to control. Dynamic simulations of ETBE and MTBE reactive distillation processes were used to explore some unusual dynamic phenomena and to elucidate the process non-linearity and bidirectionality of reactive distillation. The presence of multiple steady states for some reactive distillation columns has been documented previously but the analysis of this behaviour has been incomplete and somewhat flawed. It was shown that the distinction between molar inputs and physically realisable mass or volumetric inputs is crucial and that multiplicity could be present in one case and not in the other. Multiplicity that is only observed with molar inputs (relatively common) was termed pseudo-multiplicity. Pseudo-multiplicity has few implications for the operation and control of practical reactive distillation processes although most literature examples of multiple steady states fall into this category. Four distinct causes of output multiplicity were identified including one new cause, reaction hysteresis, which is only applicable to hybrid reactive distillation. It was shown, using dynamic simulations, that transitions between parallel steady states are possible for a range of physically realisable and practical disturbances. This contrasts with other work in the area, which examines only unrealisable events and control schemes.An extensive analysis of reactive distillation control was also undertaken with respect to ETBE and MTBE hybrid columns. Manual (open-loop) control was shown to be impractical due to the need to sustain the operating conditions at close to the optimal values in order to produce acceptable process performance. One-point composition control was found to be relatively easy to implement and effective with either an energy-balance or a material-balance control scheme provided only one steady state was present. Where multiple steady states exist, there are restrictions on the feasible control structures due to unavoidable instability in the inventory controllers. For example, if multiple steady states exist for the one value of the reboiler duty, only the bottoms product draw rate can be used to control the reboiler sump level. Thus, a material-balance control structure that uses the reboiler duty to control the sump level cannot be implemented in practice. Two-point control was also investigated and found to effectively prevent transitions between parallel steady states. Although more complex and difficult to implement than one-point control, a two-point scheme could be used successfully to control both the product composition and the reactant conversion and this could be desirable in some cases.A reactive distillation pilot plant was designed and operated for ETBE synthesis from ethanol and a locally available refinery hydrocarbon stream. The design of the pilot plant was based on simulation studies and the objective of operating in the industrially significant ranges of product purity and isobutene conversion. A fully automatic control system was designed and installed on the pilot plant to permit precise control of the manipulated variables and the framework to implement a range of control structures and schemes.Keywords: reactive distillation; process simulation; process design; process control; dynamic simulation; multiplicity; bidirectionality; distillation control; inferential control; pilot plant design and operation.
2
Alici, Semra. "Dynamic data reconciliation using process simulation software and model identification tools." Access restricted to users with UT Austin EID Full text (PDF) from UMI/Dissertation Abstracts International, 2001. http://wwwlib.umi.com/cr/utexas/fullcit?p3025133.
Full text
3
Spirito, Mario. "Simulation, control and optimization of asphalt drying process." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2018.
Find full textAbstract:
Il documento presentato punta alla descrizione del lavoro svolto dal DEI in collaborazione con l'azienda Marini-Fayat la quale ha sviluppato un prototipo innovativo per l'essiccazione di asfalti.
L'obiettivo di tale collaborazione ha riguardato principalmente attività di studio della letteratura circa il processo di essiccazione degli asfalti, la sua modellazione e il controllo dell'intero impianto rispettandone i vincoli imposti.
Il lavoro si svolto nel seguente modo, dopo lo studio della letteratura sull'argomento, due tipologie di modello sono state sviluppate: un "Evaluation model" che divideva l'impianto in sezioni concatenate di lunghezza fissata e voleva descrivere in maniera fine i comportamenti fisici del sistema, a questo si è aggiunto lo sviluppo di un "control model" con l'obiettivo di riportare solo i fenomeni principali di questo processo di essiccazione, portando così a una maggiore leggerezza computazionale.
Al fine di testare le azioni di controllo si sono pensati degli esperimento per la stima dei parametri di sistema. Una volta noti tali parametri è stato possibile convalidare l'effettiva funzionalità dei controllori sviluppati sul più leggero e performante "control model" con ottimi risultati.
4
Zhao, Jian 1963. "Simulation of boiler drum process dynamics and control." Thesis, McGill University, 1992. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=61104.
Full textAbstract:
This thesis presents a mathematical process model for the dynamic analysis of a vertical reheat boiler and the application of this model to the optimal design of a drum water level controller. A numerical finite difference technique is used to formulate this model.The control system contains two loops, a feedfoward loop using the steam flow and drum pressure signals as the input and a feedback loop using the deviation of the measured drum water level from its set point as an input. The feedback loop is an incremental PID controller with an adjustable proportional gain. The feedfoward loop is designed to directly actuate the control devices before the "swell" and "shrinkage" in the boiler water level occur. The feedforward controller output signal is summed along with the output of the PID controller to establish the set point for the control actuator. This scheme is effective because steam flow changes are immediately fed forward to change the final feedwater set point for the control actuator. In this way, feedwater flow tracks steam flow and any disturbances in the feedwater system will be arrested quickly.
It is shown that an incremental PID controller plus adapt feedfoward compensator can be successfully employed for the control of water level in such a plant.
5
Cameron, Ewan A. "Enhancement of process control using real-time simulation." Thesis, University of Edinburgh, 1989. http://hdl.handle.net/1842/10860.
Full text
6
Sneesby, Martin G. "Simulation and control of reactive distillation." Curtin University of Technology, School of Chemical Engineering, 1998. http://espace.library.curtin.edu.au:80/R/?func=dbin-jump-full&object_id=10629.
Full textAbstract:
Reactive distillation has enormous potential for the economical synthesis of tertiary ethers. Methyl tert-butyl ether (MTBE) has been commercially produced with this technology since the early 1980s and it appears that the process also has application for Ethyl tert-butyl ether (ETBE) and other ethers. However, the combination of reaction and distillation in a single unit operation produces a process complexity that inhibits expeditious design and tight control, and presents a technology risk for potential developers. This particularly applies to hybrid reactive distillation where both reactive and non-reactive column sections are employed.The steady state simulation of a series of reactive distillation columns and processes for the production of ETBE and MTBE illuminated a number of important issues related to the optimal design techniques. Many of these issues are peculiar to reactive distillation and would not reasonably be anticipated without a priori knowledge of the phenomena involved. For example, the addition of theoretical equilibrium stages and an increase in the reflux ratio do not always have a directionally equivalent effect. The trade-off between energy consumption and capital cost which is the basis for most distillation designs cannot always be applied to reactive distillation. Importantly, the use of standard modelling techniques for equilibrium processes was also validated for reactive distillation design.The use of residue curve diagrams and reactive residue curve diagrams for the design of reactive distillation processes was investigated and shown to provide useful information regarding the feasibility of reaction-separations. Combined with simulation tools (e.g. Pro/II and SpeedUp), these techniques form the basis of a proposed design strategy for hybrid reactive distillation. It is important to apply these design tools appropriately and to ++select the correct process for a given application. The optimal design must also consider economics and the relative values of products, reactants and energy. These issues were studied with respect to ETBE production for gasoline oxygenation.The complexity of hybrid reactive distillation not only presents design challenges but potentially makes the process more difficult to control. Dynamic simulations of ETBE and MTBE reactive distillation processes were used to explore some unusual dynamic phenomena and to elucidate the process non-linearity and bidirectionality of reactive distillation. The presence of multiple steady states for some reactive distillation columns has been documented previously but the analysis of this behaviour has been incomplete and somewhat flawed. It was shown that the distinction between molar inputs and physically realisable mass or volumetric inputs is crucial and that multiplicity could be present in one case and not in the other. Multiplicity that is only observed with molar inputs (relatively common) was termed pseudo-multiplicity. Pseudo-multiplicity has few implications for the operation and control of practical reactive distillation processes although most literature examples of multiple steady states fall into this category. Four distinct causes of output multiplicity were identified including one new cause, reaction hysteresis, which is only applicable to hybrid reactive distillation. It was shown, using dynamic simulations, that transitions between parallel steady states are possible for a range of physically realisable and practical disturbances. This contrasts with other work in the area, which examines only unrealisable events and control schemes.An extensive analysis of reactive distillation control was also undertaken with respect to ETBE and MTBE hybrid columns. Manual (open-loop) control was shown to be impractical due to ++
the need to sustain the operating conditions at close to the optimal values in order to produce acceptable process performance. One-point composition control was found to be relatively easy to implement and effective with either an energy-balance or a material-balance control scheme provided only one steady state was present. Where multiple steady states exist, there are restrictions on the feasible control structures due to unavoidable instability in the inventory controllers. For example, if multiple steady states exist for the one value of the reboiler duty, only the bottoms product draw rate can be used to control the reboiler sump level. Thus, a material-balance control structure that uses the reboiler duty to control the sump level cannot be implemented in practice. Two-point control was also investigated and found to effectively prevent transitions between parallel steady states. Although more complex and difficult to implement than one-point control, a two-point scheme could be used successfully to control both the product composition and the reactant conversion and this could be desirable in some cases.A reactive distillation pilot plant was designed and operated for ETBE synthesis from ethanol and a locally available refinery hydrocarbon stream. The design of the pilot plant was based on simulation studies and the objective of operating in the industrially significant ranges of product purity and isobutene conversion. A fully automatic control system was designed and installed on the pilot plant to permit precise control of the manipulated variables and the framework to implement a range of control structures and schemes.Keywords: reactive distillation; process simulation; process design; process control; dynamic simulation; multiplicity; bidirectionality; distillation control; inferential control; pilot plant design and operation.
7
Liu, Pi-Shien 1960. "Real-time process control and simulation for chemical mix facility." Thesis, The University of Arizona, 1988. http://hdl.handle.net/10150/276673.
Full textAbstract:
The purpose of this study is to design a real-time control and simulation system for a chemical mix facility. A simulation circuit board and software simulation in an IBM personal computer emulated the real-time chemical mix facility. A second personal computer controlled the plant. The parallel port in the IBM PC computer serves as a communication path between the controlled and controlling system. Results show that the simulation can assist the design of the actual system.
8
Godfrey, Simon. "Honeywell Experion System: Configuration, simulation and process control software interoperability." Thesis, Godfrey, Simon (2016) Honeywell Experion System: Configuration, simulation and process control software interoperability. Honours thesis, Murdoch University, 2016. https://researchrepository.murdoch.edu.au/id/eprint/35817/.
Full textAbstract:
The use of automated distributed control systems has become a widely discussed topic as industry attempts to maximise efficiency. An increase in automation technology has resulted in demand for “industry ready” graduate engineers with knowledge and experience with such technologies. Murdoch University (Murdoch) provides students with exposure to industry standard automation systems such as Honeywell’s Experion Process Knowledge System (PKS), a Distributed Control System (DCS) designed for the control and optimisation of industrial plants.
Presently, Murdoch uses Experion to monitor and control its pilot plant, exposing instrumentation and control students to the configuration and control of an industrial plant. Additionally, Murdoch holds a second Experion simulation license providing the ability to program and simulate process and control strategies. This project scope was to explore several key areas of the Experion simulation system followed by the development of a series of learning materials to facilitate the teaching of the Experion system to students for a new unit to be introduced at Murdoch University in 2017.
The methodology adopted to achieve the project outcome involved developing a comprehensive understanding of Experion and its associated applications, before building a series of example simulation programs for the purpose of implementing and testing a variety of Experion’s control strategies. Additionally, real-time control of the Experion simulation programs, using third party process control software, was achieved. The successful interoperability of MATLAB, Simulink, and LabVIEW with Experion provides an avenue for implementing advanced control strategies both in simulation and on Murdoch’s pilot plant.
At the conclusion of the project, an extensive list of learning materials was produced, providing comprehensive procedures to enact tasks within the Experion system. This includes initial setup and configuration, development of simulated programs and associated Human Machine Interface (HMI) displays, the implementation of control strategies, and third party process control software interoperability. These learning materials provide students with an enhanced learning experience, giving them the skills and exposure required to thrive in the automation engineering industry as a Murdoch University graduate.
9
Von, Raubenheimer Albert Ludwich. "Strategic supply chain management using simulation." Pretoria : [s.n.], 2005. http://upetd.up.ac.za/thesis/available/etd-12012005-092956/.
Full text
10
Cox, Steven. "Simulation and control of univariate and multivariate set-up dominant process." Thesis, Durham University, 2015. http://etheses.dur.ac.uk/11383/.
Full textAbstract:
This thesis explores the use of statistically valid process improvement tools in low-volume applications. Setting out the following research questions: How can the Six Sigma Measure and Analyse phases of a chronic quality problem be statistically validated in a low-volume process? How can a statistically valid approach for process control be implemented in a low-volume process? And how can this tool be extended to fit multivariate processes and can the calculation of control parameter adjustments be automated? In answer, the thesis presents an enhanced PROcess VAriation Diagnosis Tool (PROVADT) method, driving a Six Sigma improvement project through the Measure and Analyse phases. PROVADT provides a structured sampling plan to perform a Multi-Vari study, Isoplot, Gage R&R and Provisional Process Capability in as few as twenty samples and eighty measurements, making the technique suited to low-volume applications. The enhanced PROVADT method provides a Gage R&R without confounded variation sources, as was the case in the original method, and its practical application was demonstrated through two case studies. Process control tools for low-volume, high-variety manufacturing applications were developed. An adjustable traffic-light chart, with control limits linked to tolerance and simple decision rules, was used for monitoring univariate processes. This tool, the Set-Up Process Algorithm (SUPA), uses probability theory to provide 98% confidence that the process is operating at a pre-specified minimum level of Cp in as few as five samples. SUPA was extended to deal with high-complexity applications, resulting in multivariate SUPA (mSUPA). mSUPA maintains SUPA’s principles, but presents the information about multiple process features on one chart, rather than multiple univariate charts. To supplement the mSUPA tool, a theoretical method for calculating optimal process adjustment when a multivariate process is off-target was introduced, combining discrete-event simulation and numerical optimisation to calculate adjustments.
11
Grossi, Matteo. "Dynamic design, optimization and simulation of a control strategy for a pharmaceutical bioprocess." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2019. http://amslaurea.unibo.it/17906/.
Full textAbstract:
In recent years, pharmaceutical companies have grown interest in developing new technologies for the continuous manufacturing of drug products. The continuous manufacturing of pharmaceuticals is critical in order to increase productivity and to reduce the amount of overall waste in a time-efficient manner. To strive towards this goal, in this work, the realistic case study of the continuous production of lovastatin is investigated and modeled. Therefore, based on the steady-state model proposed by Colombo et al. (2018) [1], a control plant-wide control strategy is developed and simulated for a semi-continuous benchmark simulation model for the production of lovastatin. Hence, the upstream and downstream processes have been integrated with feedback control systems using rigorous non-linear dynamic process models, in order to reach an accurate control of the process variables, and thus consistently maintain the predefined product quality. The proposed strategy ultimately leads to the identification and the development of a comprehensive benchmark model of an end-to-end plant-wide controlled system that, as it captures the generic dynamics of a bio-pharmaceutical process, can be deemed as a starting point for further simulations and implementations of other chemical process units. The results showed that under considerable and durable disturbances, the designed control strategy is capable to take action and adjust the process variables to their set points values, thus attesting for the effectiveness of the proposed model.
12
Ekman, Mats. "Urban water management : Modelling, simulation and control of the activated sludge process." Licentiate thesis, Uppsala universitet, Avdelningen för systemteknik, 2003. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-86143.
Full textAbstract:
During the last few decades, wastewater treatment processes in urban water management have become more and more efficient and complex. Several factors such as urbanization, stricter legislations on effluent quality, economics, increased knowledge of the involved biological, chemical and physical processes as well as technical achievements have been important incentives for the development of more efficient procedures for wastewater treatment plants. Future requirements on more sustainable urban water systems, in combination with increasing wastewater loads, will most probably further increase the need for optimization and control of both existing and emerging wastewater treatment processes. In this thesis estimation, modelling and control strategies are developed in order to improve the efficiency of the activated sludge process. The first part of the thesis presents a JAVA based simulator of the activated sludge process. An overview of its features, with some emphasis on implemented control strategies, is given. In particular, a new control strategy for the internal recycling flow rate is described. A summary of experiences from using the simulator as a teaching and training tool is also given. The second part of the thesis includes a derivation of reduced order models for the activated sludge process. The resulting models, a time-varying linear state-space model for the anoxic part and a time-varying bilinear state-space model for the aerobic part, are intended to be used for control applications. In the third part, an adaptive control strategy for control of the nitrate level using an external carbon source is presented. The controller adapts and compensates for changes in the system dynamics since important system parameters are estimated adaptively and incorporated on-line in the control design. The estimated system parameters and model states also give guidance about the state of the process and the characteristics of the wastewater. Several simulation examples are used to illustrate the control law. Finally, a new suboptimal control law for the bilinear quadratic regulator problem with infinite final time is presented. The control strategy is evaluated in a simulation study, where special concern is devoted to controlling the activated sludge process, using the bilinear model developed in the second part of this thesis.
13
Gil, Iván-Dario. "Modeling, Simulation, Dynamic Optimization and Control of a Semibatch Emulsion Polymerization Process." Thesis, Université de Lorraine, 2014. http://www.theses.fr/2014LORR0036/document.
Full textAbstract:
Dans ce travail, la modélisation, la simulation, l'optimisation dynamique et la commande nonlinéaire d'un procédé industriel de polymérisation en émulsion produisant du polyacétate de vinyle (PVAc) sont étudiées. La réaction est modélisée comme un système à deux phases constitué d'une phase aqueuse et une phase particulaire. Un modèle détaillé est développé pour calculer la masse molaire moyenne en poids, la masse molaire moyenne en nombre et la dispersité. Les moments de chaînes en croissance et terminés sont utilisés pour représenter l'état du polymère et pour calculer la distribution de masse molaire (MWD). L'étude de cas correspond à un réacteur industriel fonctionnant dans une entreprise de produits chimiques à Bogotá. Un réacteur à l'échelle industrielle (11 m3 de capacité) est simulé dans lequel une réaction semi-batch de polymérisation en émulsion de l'acétate de vinyle est effectuée. Le problème d'optimisation dynamique est résolu directement en utilisant un solveur de programmation non linéaire. L'intégration des équations différentielles est faite en utilisant la méthode de Runge-Kutta. Trois problèmes d'optimisation différents sont résolus, depuis le plus simpliste (une seule variable d'optimisation : la température du réacteur) au plus complexe (trois variables d'optimisation : la température du réacteur, le débit de l'amorceur et le débit du monomère) en vue de minimiser le temps final de réaction. Une réduction de 25% du temps de traitement par batchs est réalisée par rapport aux conditions normales de fonctionnement appliquées dans l'entreprise. Les résultats montrent qu'il est possible de minimiser la durée de réaction alors que certaines qualités de polymères souhaitées (conversion, masse molaire et contenu en solides) satisfont les contraintes définies. Une technique de commande non linéaire géométrique à l'aide de la linéarisation entrée/sortie est adaptée à la régulation de la température du réacteur. Un filtre Kalman étendu (EKF) est mis en oeuvre pour estimer les états non mesurés et il est testé dans différents cas, dont une étude de robustesse où des erreurs du modèle sont introduites pour vérifier son bon fonctionnement. Après vérification des performances du régulateur, certains changements d'opération du procédé ont été proposés afin d'améliorer la productivité du procédé et la qualité du polymère. Enfin, le profil de température optimale et les politiques d'alimentation optimales de débits du monomère et de l'amorceur, obtenues dans l'étape d'optimisation dynamique, ont fourni les consignes optimales pour la commande non linéaire. Les résultats montrent que le régulateur non linéaire conçu ici convient pour suivre les trajectoires optimales de température calculées précédemmentIn this work, modeling, simulation, dynamic optimization and nonlinear control of an industrial emulsion polymerization process to produce poly-vinyl acetate (PVAc) are proposed. The reaction is modeled as a two-phase system composed of an aqueous phase and a particle phase. A detailed model is used to calculate the weight average molecular weight, the number average molecular weight and the dispersity. The moments of the growing and dead chains are used to represent the state of the polymer and to calculate the molecular weight distribution (MWD). The case study corresponds to an industrial reactor operated at a chemical company in Bogotá. An industrial scale reactor (11 m3 of capacity) is simulated where a semi-batch emulsion polymerization reaction of vinyl acetate is performed. Dynamic optimization problem is solved directly using a Nonlinear Programming solver. Integration of differential equations is made using Runge-Kutta method. Three different optimization problems are solved from the more simplistic (only one control variable: reactor temperature) to the more complex (three control variables : reactor temperature, initiator flow rate and monomer flow rate) in order to minimize the reaction time. A reduction of 25% of the batch time is achieved with respect to the normal operating conditions applied at the company. The results show that is possible to minimize the reaction time while some polymer desired qualities (conversion, molecular weight and solids content) satisfy the defined constraints. A nonlinear geometric control technique by using input/output linearization is adapted to the reactor temperature control. An extended Kalman filter (EKF) is implemented to estimate unmeasured states and it is tested in different cases including a robustness study where model errors are introduced to verify its good performance. After verification of controller performance, some process changes were proposed in order to improve process productivity and polymer quality. Finally, the optimal temperature profile and optimal feed policies of the monomer and initiator, obtained in a dynamic optimization step, are used to provide the optimal set points for the nonlinear control. The results show that the nonlinear controller designed here is appropriate to follow the optimal temperature trajectories calculated previously
14
Goodall, William Richard. "Scheduling and control in the batch process industry using hybrid knowledge based simulation." Thesis, University of Warwick, 1993. http://wrap.warwick.ac.uk/78612/.
Full textAbstract:
This thesis relates to the area of short term scheduling and control in batch process plants. A batch process plant consists of individual plant items linked by a pipe network through which product is routed. The structure of the network and the valve arrangements which control the routing severely constrains the availability of plant items for configuration in routes when a plant is operating. Current approaches to short term scheduling contain simplifying assumptions which ignore these constraints and this leads to unrealistic and infeasible schedules. The work undertaken investigates the use of techniques from the areas of Artificial Intelligence (AI) and Discrete Event Simulation (DES) in order to overcome these simplifying assumptions and develop good schedules which can be implemented in a plant. The main divisions of work cover a number of areas. The development of a representation scheme for batch plant networks, and procedures for reasoning about the constraints imposed by their structure to infer the actual availability of plant items for routing purposes at any time. The development of a dynamic rule-based route configuration procedure which takes into account the constraints on plant item availability. The development of an activity scheduling framework for batch plants based on this. The development of a dynamic simulation model to take account of finite capacity constraints in a batch plant. The integration of these elements in a hybrid structure to make best use of the techniques available from the areas of AI and DES. The representation scheme and procedures developed for reasoning about the constraints in a plant network enable the simplifying assumptions of other approaches to be overcome so that the system can produce good feasible schedules. The hybrid structure is a practical one to take for implementation and enables the best use of techniques from AI and DES.
15
Mohd, Noraini. "Plantwide Control and Simulation of Sulfur-Iodine Thermochemical Cycle Process for Hydrogen Production." Thesis, Curtin University, 2018. http://hdl.handle.net/20.500.11937/70524.
Full textAbstract:
A PWC structure has developed for an industrial scale SITC plant. Based on the performance evaluation, it has been shown that the SITC plant developed via the proposed modified SOC structure can produce satisfactory performance – smooth and reliable operation. The SITC plant is capable of achieving a thermal efficiency of 69%, which is the highest attainable value so far. It is worth noting that the proposed SITC design is viable on the grounds of economic and controllability.
16
Nguyen, Khanh. "Evaluation of respirometry-based control strategies for the activated sludge process by computer simulation." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape8/PQDD_0002/MQ46599.pdf.
Full text
17
Woldai, Abraha. "Modelling, simulation and adaptive control of a multi-stage flash (MSF) seawater desalination process." Thesis, University of Bath, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.242796.
Full text
18
MacDonald, Angus Joseph. "Integrating CAM and process simulation to enhance the analysis and control of IC fabrication." Thesis, University of Edinburgh, 1989. http://hdl.handle.net/1842/12495.
Full text
19
Illes-Smith, Peter C. "A study of the modelling, dynamic simulation and control of the modern fluid catalytic cracking process." Thesis, University of Leeds, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.330143.
Full text
20
Liu, Qingyun. "Statistical Process Control for the Fairness of Network Resource Distribution." FIU Digital Commons, 2011. http://digitalcommons.fiu.edu/etd/518.
Full textAbstract:
The purpose of this research is to develop a statistical method to monitor the fairness of network resource distribution. The newly developed fairness score function allows users to have the same or different priority levels. Especially, this function possesses all the necessary properties required as a quality characteristic for the purpose of statistical process control.
The main objective is to find the critical values for the statistical test. Monte Carlo simulation is used to find the critical values. When the users have the same priority level, a table of the critical values is given for different sample sizes and different significance levels. When the users have different priority levels, it is difficult to generate a similar table since the users’ priority levels vary. Therefore, the critical values are computed for given priority levels. In both cases, an example is given to demonstrate the approach developed in this study.
21
Vidal, Santos Saulo Fernando dos 1987. "Simulação dinâmica para avaliação de controle de um sistema de resfriamento de líquido." [s.n.], 2012. http://repositorio.unicamp.br/jspui/handle/REPOSIP/266688.
Full textAbstract:
Orientador: Ana Maria Frattini FiletiDissertação (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
22
Reddy, Shailendra N. "A mathematical simulation of ETS' limestone emission control (LEC) process using a moving bed configuration." Ohio : Ohio University, 1991. http://www.ohiolink.edu/etd/view.cgi?ohiou1183736591.
Full text
23
Lamp, Shane B. "Equipment specification, process control, and plant simulation for a lignin-fueled fluidized bed combustor plant." Morgantown, W. Va. : [West Virginia University Libraries], 1998. http://etd.wvu.edu/templates/showETD.cfm?recnum=224.
Full textAbstract:
Thesis (M.S.)--West Virginia University, 1998.Title from document title page. Document formatted into pages; contains xv, 98 p. : ill. (some col.). Vita. Includes abstract. Includes bibliographical references (p. 84).
24
Scullin, Michelle E. "Integrating Value Stream Mapping and Simulation." Diss., CLICK HERE for online access, 2005. http://contentdm.lib.byu.edu/ETD/image/etd898.pdf.
Full text
25
Gonzaga, João Carlos Bastos. "Desenvolvimento de procedimento e Soft-Sensors para controle de plantas de PET." [s.n.], 2011. http://repositorio.unicamp.br/jspui/handle/REPOSIP/266832.
Full textAbstract:
Orientador: Rubens Maciel FilhoTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Química
Made available in DSpace on 2018-08-19T03:14:43Z (GMT). No. of bitstreams: 1 Gonzaga_JoaoCarlosBastos_D.pdf: 2770183 bytes, checksum: 0e70ae7f96abb82812d9755700475caa (MD5) Previous issue date: 2011
Resumo: Neste trabalho são apresentados três estudos distintos de aplicação de Plantwide Control. A primeira aplicação trata-se de um controle antecipativo (feedforward) para controlar os níveis dos reatores na etapa de polimerização, a fim de reduzir suas variabilidades e, consequentemente, a produção de refugo, sendo que, em uma planta de Politereftalato de Etileno (PET), a variação de nível dos polimerizadores interfere na viscosidade e está diretamente relacionada com a capacidade e com a qualidade de produção. A segunda aplicação mostra como desenvolver e utilizar um modelo computacional da planta de PET para possibilitar que alterações de parâmetros de processo, como temperatura e pressão, possam ser feitas sem que haja a necessidade de testes na planta real, uma vez que a existência de um modelo computacional que tenha o mesmo comportamento qualitativo da planta real permite que o efeito de perturbações e outros tipos de alterações na condição do processo sejam avaliados. A terceira aplicação trata-se da implantação de um sensor virtual (soft-sensor), utilizando redes neurais artificiais (RNA) para atuar como um medidor redundante da viscosidade, podendo substituir o sensor físico no caso deste vir a falhar. Estes estudos têm em comum a apresentação de procedimentos para controle do processo de produção de PET, que por possuir muitas particularidades, torna-se um assunto complexo, sendo um desafio modelar e controlar cada única unidade de produção
Abstract: In this work are presented three separate studies of application of Plantwide Control. The first application is a feedforward control to control the levels of reactors in polymerization step, in order to reduce their variability and, consequently, the production of waste, because, in a plant of PET, the variance of level of polymerizing interferes in viscosity and is directly related to the capacity and quality of production. The second application shows how to develop and use a computational model of a PET plant to enable changes to process parameters such as temperature and pressure, without the need of tests in actual plant, once the existence of a computational model has the same qualitative behavior of actual plant, and it allows the effect of disturbance and other types of changes in the condition of the process to be evaluated. The third application is the implantation of a virtual sensor (soft-sensor), using RNA, to act as a redundant viscosity meter that, in the case of possible failures, has as main function to detect physical sensor failures and replace it in the control system monitoring. Generally, the three studies have in common the presentation of procedures to control the production process of polyester. Process control for the production of polymers presents many particularities and, therefore, becomes a complex matter, being a challenge to model and to control every single production unit
Doutorado
Desenvolvimento de Processos Químicos
Doutor em Engenharia Química
26
Sobe, Udo, Karl-Heinz Rooch, and Dietmar Mörtl. "Simulation and Analysis of Analog Circuit and PCM (Process Control Monitor) Test Structures in Circuit Design." Universitätsbibliothek Chemnitz, 2007. http://nbn-resolving.de/urn:nbn:de:swb:ch1-200700919.
Full textAbstract:
PCM test structures are commonly used to check the produced wafers from the standpoint of the technologist. In general
these structures are managed inside the FAB and are focused on standard device properties. Hence their development and
analysis is not driven by analog circuit blocks, which are sensitive or often used. Especially for DFM/Y of analog circuits
the correlation between design and technology has to be defined. The knowledge of electrical behavior of test structures
helps to improve the designer's sensitivity to technological questions.
This paper presents a method to bring the PCM methodology into the analog circuit design to improve design performance,
yield estimation and technology correlation. We show how both analog circuit and PCM blocks can be simulated and
analyzed in the design phase.
27
Salvador, Francisco. "Projeto de um sistema de refreigeração industrial com \"Set-Point\" variável." Universidade de São Paulo, 1999. http://www.teses.usp.br/teses/disponiveis/3/3139/tde-05102010-112239/.
Full textAbstract:
Os sistemas térmicos operam na maior parte do tempo fora de suas condições nominais de projeto. Nos sistemas de refrigeração industrial, a operação com carga térmica parcial ocorre em função de diversos fatores e o consumo de energia apresenta grande variação em função do ciclo de operação. Neste trabalho é proposta a otimização energética dos sistemas frigoríficos por compressão a vapor através da operação com regime variável para o ciclo frigorífico, especificamente através da operação com set-point de temperatura de evaporação variável. Para tanto é desenvolvido um modelo matemático para simulação dinâmica de um sistema de refrigeração industrial por compressão a vapor com refrigerante amônia (R-717) para o congelamento de alimentos composto basicamente de túnel de congelamento por circulação forçada de ar, evaporador com recirculação de líquido, reservatório de líquido a baixa pressão, compressores parafuso e condensador evaporativo atmosférico. São analisados através de simulação dois métodos para a variação do setpoint de temperatura de evaporação: a máxima temperatura de evaporação admissível e a minimização da potência no compressor. Os dois métodos são comparados ao sistema de controle de capacidade atualmente utilizado em instalações industriais.Thermal systems operate most of the time at off-design conditions. In industrial refrigeration systems, the operation in partial loads occurs for many different reasons and the power consumption is a function of the refrigeration cycle pressures. This work proposes an energetic optimization of the compression refrigeration systems by the operation with a variable refrigeration cycle, specifically, by the operation with a variable suction temperature set-point. For this purpose it is developed a mathematical model for dynamic simulation of a industrial refrigeration compression system for food freezing with ammonia refrigerant (R717) formed by an air blast belt freezer, liquid overfeed evaporators, low pressure receiver, screw compressors and evaporative condenser. Two procedures for the suction temperature set-point variation are analyzed by simulation: the maximum suction temperature permitted and the compressor power consumption minimization. Both methods are compared with the capacity control system used in present industrial facilities.
28
Appell, Kenneth William. "A mathematical simulation of ETS' limestone emission control process using the method of characteristics fixed-bed configuration/gas-phase mass transport control." Ohio : Ohio University, 1989. http://www.ohiolink.edu/etd/view.cgi?ohiou1182276120.
Full text
29
Fåhraeus, Karin. "Enhancement of the Mechatronic Development Process with Software in the loop Simulation : An embedded control case study." Thesis, KTH, Maskinkonstruktion (Inst.), 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-180947.
Full textAbstract:
This master thesis is performed at the mechatronic department at the company Mycronic, which are responsible for the embedded software in their pick and place machines. Today the embedded code can be executed and tested on a PIL simulation, where the control code runs on the actual target processor and the dynamic of the system (plant model) is modeled by a mathematical equation implemented as a C-function on the target board. The task is to find away to run the simulation with the real embedded code on a desktop computer. The aim is to investigate and examine how this simulation can be achieved and the advantages and opportunities it brings to the development process of the embedded system. For embedded system, Model-based Development usually refers to control and plant modelsand simulations and in the loop simulations. In a model-based workflow it starts with Model in the loop (MIL), then Software in the loop (SIL), Processor in the loop (PIL) and finally Hardware in the loop (HIL). Software in the loop simulation means that the plant is modeled but the control is executed in a low level language such as C and the simulation runs on a desktop computer. The investigation on how to implement a simulation resulted in a prototype SIL simulator, representing one of the axes. The simulation executes the control C-code together with a z-axis plant model on a Linux desktop computer. It is realized in two ways, where both are based on compiling the control code for a Linux computer and the difference is the implementation of the plant model. For the first simulation method, the plant models is represented in the same way as the PIL simulation and for the second simulation method the plant model is represented in Simulink. The result from this master thesis is that the SIL simulation has shown to be very useful andhave a lot of advantages. The SIL simulation gives an opportunity to execute and test the code and the control before it is integrated with the target processor. Problems and errors can thus be detected early. One of the big advantages is that it is not dependent of any hardware and any other software/tool. With the SIL simulation the code gets easier to debug, longer logscan be achieved and the simulation gets closer to reality than when modeling the control. A very important part of the SIL simulation is that it includes the interaction between the mechanical design, the control design and the software design which is very important in mechatronics system. The SIL simulation contributes to be able to run the main software together with the simulation, which helps in the integration tests.Detta examensarbete är utfört på företaget Mycronic på deras mekatronikavdelning, vilka är ansvarig för utvecklingen av den inbyggda mjukvaran i deras ytmonteringsmaskiner. I dagsläget kan den inbyggda koden köras och testas i en PIL simulering, där kontrollkoden körs på det inbyggda systemet medan dynamiken av systemet är modellerad och uttryckt med matematiska ekvationer implementerat i en C-funktion. Uppgiften är att hitta ett sätt att köra en simulering med den riktiga inbyggda koden på en dator. Syftet med examensarbetet är att utreda och undersöka hur denna simulering kan förbättra utvecklingsprocessen för den inbyggda koden hos Mycronic. För inbyggda system och reglerteknik syftar Model-based Development (modellbaserad utveckling) oftast på att modeller och simulering av styrsystemet och det dynamiska systemet. Ett modellbaserat arbetsflöde startar med Model in the loop (MIL), sedan Software in the loop (SIL), Processor in the loop (PIL) och sist Hardware in the loop (HIL). Software in the loop simulering betyder att det dynamiska systemet är modellerat men styrsystemet är implementerat i en lågnivå programmeringsspråk så som C. Resultatet från undersökning som innefattade att hitta ett sätta att implementera en simulering var en SIL simulering som representerar en av axlarna och körs på två olika sätt. Simuleringen kör styrsystemets kod tillsammans med en modellering av det dynamiska systemet där skillnaden är implementeringen av denna modell. För den första metoden implementeras dynamiken på samma sätta som PIL simuleringen och för den andra metoden implementeras dynamiken i en modell i Simulink. Resultatet från detta examensarbete är att SIL simuleringen har visat sig vara väldigt användbar och har många fördelar. SIL simuleringen ger en möjlighet att köra och testa koden och regleringen innan den köra på det inbyggda systemets processor. Problem och fel kan på sätt upptäckas tidigt. En stor fördel är att SIL simuleringen inte är beroende av någon hårdvara eller annan mjukvara. Det blir enklare att felsöka koden med SIL simuleringen och längre loggningar kan göras då minnet inte är så begränsat som på det inbyggda systemet. En väldigt viktig fördel med SIL simuleringen är att den inkluderar interaktionen mellan den mekaniska, regler och mjukvaru designen. Den bidrar även till att kunna köra huvudmjukvaran ihop med det inbyggda systemets simulering, vilket hjälper till i integrationsprocessen.
30
Robles, Martínez Ángel. "Modelling, simulation and control of the filtration process in a submerged anaerobic membrane bioreactor treating urban wastewater." Doctoral thesis, Editorial Universitat Politècnica de València, 2013. http://hdl.handle.net/10251/34102.
Full textAbstract:
El reactor anaerobio de membranas sumergidas (SAnMBR) está considerado como tecnología
candidata para mejorar la sostenibilidad en el sector de la depuración de aguas residuales,
ampliando la aplicabilidad de la biotecnología anaerobia al tratamiento de aguas residuales de
baja carga (v.g. agua residual urbana) o a condiciones medioambientales extremas (v.g. bajas
temperaturas de operación). Esta tecnología alternativa de tratamiento de aguas residuales es
más sostenible que las tecnologías aerobias actuales ya que el agua residual se transforma en
una fuente renovable de energía y nutrientes, proporcionando además un recurso de agua
reutilizable. SAnMBR no sólo presenta las principales ventajas de los reactores de membranas
(i.e. efluente de alta calidad, y pocas necesidades de espacio), sino que también presenta las
principales ventajas de los procesos anaerobios. En este sentido, la tecnología SAnMBR
presenta una baja producción de fangos debido a la baja tasa de crecimiento de los
microorganismos implicados en la degradación de la materia orgánica, presenta una baja
demanda energética debido a la ausencia de aireación, y permite la generación de metano, el
cual representa una fuente de energía renovable que mejora el balance energético neto del
sistema. Cabe destacar el potencial de recuperación de nutrientes del agua residual bien cuando
el efluente es destinado a irrigación directamente, o bien cuando debe ser tratado previamente
mediante tecnologías de recuperación de nutrientes.
El objetivo principal de esta tesis doctoral es evaluar la viabilidad de la tecnología SAnMBR
como núcleo en el tratamiento de aguas residuales urbanas a temperatura ambiente. Por lo tanto,
esta tesis se centra en las siguientes tareas: (1) implementación, calibración y puesta en marcha
del sistema de instrumentación, control y automatización requerido; (2) identificación de los
parámetros de operación clave que afectan al proceso de filtración; (3) modelación y simulación
del proceso de filtración; y (4) desarrollo de estrategias de control para la optimización del
proceso de filtración minimizando los costes de operación.
En este trabajo de investigación se propone un sistema de instrumentación, control y
automatización para SAnMBR, el cual fue esencial para alcanzar un comportamiento adecuado
y estable del sistema frente a posibles perturbaciones. El comportamiento de las membranas fue
comparable a sistemas MBR aerobios a escala industrial. Tras más de dos años de operación
ininterrumpida, no se detectaron problemas significativos asociados al ensuciamiento
irreversible de las membranas, incluso operando a elevadas concentraciones de sólidos en el
licor mezcla (valores de hasta 25 g·L-1
). En este trabajo se presenta un modelo de filtración
(basado en el modelo de resistencias en serie) que permitió simular de forma adecuada el proceso de filtración. Por otra parte, se propone un control supervisor basado en un sistema
experto que consiguió reducir el consumo energético asociado a la limpieza física de las
membranas, un bajo porcentaje de tiempo destinado a la limpieza física respecto al total de
operación, y, en general, un menor coste operacional del proceso de filtración.
Esta tesis doctoral está integrada en un proyecto nacional de investigación, subvencionado por
el Ministerio de Ciencia e Innovación (MICINN), con título ¿Modelación de la aplicación de la
tecnología de membranas para la valorización energética de la materia orgánica del agua
residual y la minimización de los fangos producidos¿ (MICINN, proyecto CTM2008-06809-
C02-01/02). Para obtener resultados representativos que puedan ser extrapolados a plantas
reales, esta tesis doctoral se ha llevado a cabo utilizando un sistema SAnMBR que incorpora
módulos comerciales de membrana de fibra hueca. Además, esta planta es alimentada con el
efluente del pre-tratamiento de la EDAR del Barranco del Carraixet (Valencia, España).Robles Martínez, Á. (2013). Modelling, simulation and control of the filtration process in a submerged anaerobic membrane bioreactor treating urban wastewater [Tesis doctoral]. Editorial Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/34102
Alfresco
Premiado
31
Capaci, Francesca. "Contributions to the Use of Statistical Methods for Improving Continuous Production." Licentiate thesis, Luleå tekniska universitet, Industriell Ekonomi, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-66256.
Full textAbstract:
Complexity of production processes, high computing capabilities, and massive datasets characterize today’s manufacturing environments, such as those of continuous andbatch production industries. Continuous production has spread gradually acrossdifferent industries, covering a significant part of today’s production. Commonconsumer goods such as food, drugs, and cosmetics, and industrial goods such as iron,chemicals, oil, and ore come from continuous processes. To stay competitive intoday’s market requires constant process improvements in terms of both effectivenessand efficiency. Statistical process control (SPC) and design of experiments (DoE)techniques can play an important role in this improvement strategy. SPC attempts toreduce process variation by eliminating assignable causes, while DoE is used toimprove products and processes by systematic experimentation and analysis. However,special issues emerge when applying these methods in continuous process settings.Highly automated and computerized processes provide an exorbitant amount ofserially dependent and cross-correlated data, which may be difficult to analyzesimultaneously. Time series data, transition times, and closed-loop operation areexamples of additional challenges that the analyst faces.The overall objective of this thesis is to contribute to using of statisticalmethods, namely SPC and DoE methods, to improve continuous production.Specifically, this research serves two aims: [1] to explore, identify, and outlinepotential challenges when applying SPC and DoE in continuous processes, and [2] topropose simulation tools and new or adapted methods to overcome the identifiedchallenges.The results are summarized in three appended papers. Through a literaturereview, Paper A outlines SPC and DoE implementation challenges for managers,researchers, and practitioners. For example, problems due to process transitions, themultivariate nature of data, serial correlation, and the presence of engineering processcontrol (EPC) are discussed. Paper B further explores one of the DoE challengesidentified in Paper A. Specifically, Paper B describes issues and potential strategieswhen designing and analyzing experiments in processes operating under closed-loopcontrol. Two simulated examples in the Tennessee Eastman (TE) process simulatorshow the benefits of using DoE techniques to improve and optimize such industrialprocesses. Finally, Paper C provides guidelines, using flow charts, on how to use thecontinuous process simulator, “The revised TE process simulator,” run with adecentralized control strategy as a test bed for developing SPC and DoE methods incontinuous processes. Simulated SPC and DoE examples are also discussed.
32
Bhagavatula, Narayan L. "Modeling and experimental verification of pressure prediction in the in-mold coating process for thermoplastic substrates." Columbus, Ohio : Ohio State University, 2006. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1145371989.
Full text
33
German, Alina. "Usage of aviation simulator in a process of ATS officers training." Thesis, Національний авіаційний університет, 2020. http://er.nau.edu.ua/handle/NAU/42352.
Full textAbstract:
Робота публікується згідно наказу ректора від 21.01.2020 р. №008/од "Про перевірку кваліфікаційних робіт на академічний плагіат 2019-2020р.р. навчальному році" . Керівник проекту: доцент, Богуненко Микола МиколайовичAviation is a sphere where voice communication system plays a great role. Proficiency in English is a key tool for an air traffic controller and phraseology of radio exchange has a number of specific features. Air traffic controller’s work includes maintaining an orderly flow of air traffic, servicing of an aircraft and control of safe movement on the ground and in the airspace. The only way to communicate with the pilot is a radio communication, which takes place in a real-time operation and requires maximum attention from the specialist. Among the below overviewed means and methods of training, a special place is taken by simulator training, which has the closest connection with the formation of ATCO's high competence and confidence. For this purpose, the existing training systems and theoretical approach foe studying was analyzed. Training simulators allow the formation of knowledge, skills and abilities, as well as professionally important qualities. The main purpose of this work is to present the device that can be used for aviation personal training, as well as in different directions. The aim of this graduate thesis is an investigation of existing training system for an ATCO, its components and training simulators to be used for a specialist preparation and creation of new simulator for aviation personnel training. The following tasks have to get accomplished: 1) Analyze general process of aviation personnel simulator training; 2) Analyze the process of professional skills formation; 3) Analyze human factor affects and its reduction due to skills training; 4) Overview of new simulator system and its usage.
34
Dureau, Maxime. "Characterization and simulation of the mechanical forces that control the process of Dorsal Closure during Drosophila melanogaster embryogenesis." Thesis, Lyon, École normale supérieure, 2015. http://www.theses.fr/2015ENSL0999/document.
Full textAbstract:
Le travail de thèse présenté ici vise à caractériser et simuler les forces mécaniques impliquées dans le processus de fermeture dorsale chez l’organisme Drosophila melanogaster. Ce processus participe à l’acquisition par l’embryon de sa forme finale. Ainsi, l’objectif du travail présenté ici est d’approfondir nos connaissances sur la mécanique des tissus,ainsi que sur leur rôle dans l’embryogenèse.La fermeture dorsale est un processus similaire à la cicatrisation, dans lequel la fermeture du trou dorsal est réalisée par l'amnioséreuse, qui couvre le trou dorsal, et la rangée la plus dorsale des cellules de l'épiderme: les leading edge cells.Une partie du travail présenté ici étudie aussi les mouvements des cellules du leading edge,dans le but de comprendre l’effet du câble d’actine sur la dynamique de la fermeture dorsale.Un algorithme permettant de détecter les contours des cellules, leur position ainsi que celle de leurs jonctions multiples a été développé, ainsi qu'un interface utilisateur.Différents modèles dynamiques ont ensuite été construits, prenant en compte différents comportements mécaniques, selon l’approche lagrangienne. Les systèmes d’équations ont été résolus numériquement, et leurs prédictions comparées aux données biologiques selon l’approche des moindres carrés. Les résultats ont été validés par le test de la fonction d’auto corrélation.Les résultats présentés dans cette thèse nous permettent de mieux comprendre les processus mécaniques impliqués dans les oscillations des cellules de l’amnioséreuse. Ils nous donnent aussi des indices sur leurs caractéristiques biologiques. Ils nous permettent enfin de mieux appréhender le rôle du cabled’actine dans ce processusThe work presented here aims at characterizing and simulating the mechanical forces involved in the process of Dorsal Closure in the organism Drosophila melanogaster, an embryonic process. In particular, Dorsal Closure participates in the acquisition of the final form of the embryo. Therefore, the work presented here aims at fathoming our knowledge on tissues mechanics, as well as their role in the acquisition of shape. The tissues involved in Dorsal Closure are the epidermis and the amnioserosa. At this stage of development, the epidermis surrounds almost all the embryo. Nevertheless, the amnioserosa still covers a large area of the dorsal side called dorsal hole. Hence, Dorsal Closure aims at shutting this hole and joining the lateral sides of the epidermis, in a process similar to wound healing. In order to fuse the two sides of the epidermis on the dorsal line, the epidermis must be drawn dorsalward. This movement is driven by the amnioserosa on the one hand, and by the dorsalmost row of the epidermis (called Leading Edge cells) on the other hand. The latter first form a transcellular Actin Cable around the dorsal hole. The cable, contracting, will reduce the area of the dorsal hole, covered by the amnioserosa. Second, the Leading Edge cells emit protrusions that will attach to the opposite Leading Edge and drag it toward themselves, untill the two sides of the epidermis fuse. These protrusions have a limited range, hence the dragging and fusion only take place at the ends of the dorsal hole (called canthi), where the distance between the two Leading Edges is small enough. The Amnioserosa also drags the epidermis toward the dorsal line. Its cells produce a contractile network. Interstingly, Amnioserosa cells see the area of their top side (apical side) vary in a periodic way. Although these variations have been widely studied, their role in Dorsal Closure remains unknown. This PhD aims at improving our knowledge of the mechanical concepts involved in these oscillations, and to build a physical model representing these movements. The work presented here also studies the movements of the Leading Edge cells, in order to understand the effect of the Actin Cableon the dynamics of Dorsal Closure. In order to study the cells movements and the role of the tissues involved in Dorsal Closure, an algorithm was developped, allowing to detect the cells edges, their position, as well as those of their vertices (multiple junction between three or four cells) and to track them over time. A user interface was also developped, in order to facilitate the adjustment of the parameters allowing the detection, as well as the correction of possible errors. Various dynamical models were then built following the lagrangian approach. The systems of equations deriving from the Euler-Lagrange equations were numerically solved, and their predictions compared to the biological data extracted thanks to the algorithm presented earlier, following the least square approach. The model validation was performed thanks to the autocorrelation function test. Finally, the Leading Edge dynamics was studied characterising the cellular movements at the interface between the epidermis and the amnioserosa. Wild type embryos dynamics were compared to those of mutated embryos showing specific defects in the Actin Cable formation. The results presented in this manuscript allow a better understanding of the processes involved in in Amnioserosa cells oscicllations. They also give clues on their biological characteristics. Finally, they assess the role of the actin cable in this process similar to wound healing
35
Mousavi, Takami Kourosh. "Process Control and Simulation of Ferromagnetic Strip in the Power Transformers and Electrical Machines Applications : Electric power systems." Doctoral thesis, Västerås : School of Sustainable Development of Sociaty and Technology, Mälardalen University, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-6648.
Full text
36
Yang, Xiaochuan. "Simulation of atomization process coupled with forced perturbation with a view to modelling and controlling thermoacoustic instability." Thesis, University of Manchester, 2017. https://www.research.manchester.ac.uk/portal/en/theses/simulation-of-atomization-process-coupled-with-forced-perturbation-with-a-view-to-modelling-and-controlling-thermoacoustic-instability(be01a5bf-41ab-43ea-b96d-9240eded7cb7).html.
Full textAbstract:
Thermoacoustic instability is of fundamental and applied interest in both scientific research and practical applications. This study aims to explore several very important sub-aspects in this field and contribute to a better understanding of thermoacoustic instability as encountered in typical gas turbines and rocket engines. Atomization has been recognized as a key mechanism in driving applied thermoacoustic instability. In this regard, this study mainly focuses on the atomization process relevant for delineation of thermoacoustic instability, contributing to a comprehensive understanding of the effect of acoustics on primary and secondary atomization. Firstly, a tree-based adaptive solver and VOF method are employed to simulate the jet primary atomization. The code is validated by theoretical, numerical and experimental results to demonstrate its capability and accuracy in terms of atomization in both low-speed and high-speed regime. Perturbation frequency and amplitude have shown to affect the atomization significantly. Besides, the effect of acoustic forcing on liquid ligament has also been numerically investigated. A volume source term is introduced to extend the solver to model the compressible effects in the presence of acoustic forcing. The influence of acoustic wave number, amplitude and frequency has been examined in detail. In terms of modelling the thermoacoustic instability, bifurcation analysis is carried out for a time-delayed thermoacoustic system using the Method of Line approach. Good predictions have been obtained to capture the nonlinear behaviors inherent in the system. Moreover, model-based simulation and control of thermoacoustic instability have been conducted. A low-order wave-based network model for acoustics is coupled with nonlinear flame describing function to predict the nonlinear instability characteristics in both frequency and time domain. Furthermore, active feedback control is implemented. Two different controllers have been designed to eliminate the thermoacoustic instability to an acceptably low level and may be employed in a practical manner.
37
Tashtoush, Tariq Husni. "Using lean principles and simulation to enhance the effectiveness of a failure analysis laboratory in a manufacturing environment." Diss., Online access via UMI:, 2009.
Find full textAbstract:
Thesis (M.S.)--State University of New York at Binghamton, Thomas J. Watson School of Engineering and Applied Science, Department of Systems Science and Industrial Engineering, 2009.Includes bibliographical references.
38
Chen, Shuai. "Investigation of FEM numerical simulation for the process of metal additive manufacturing in macro scale." Thesis, Lyon, 2019. http://www.theses.fr/2019LYSEI048/document.
Full textAbstract:
La fabrication additive (FA) est devenue une nouvelle alternative pour la fabrication des pièces dans l'industrie. Cependant, il existe encore des limites pour ce procédé, en particulier la forme finale défavorable et les propriétés macroscopiques indésirables des pièces métalliques construites dans les systèmes de FA. La distorsion ou la fissure due à la contrainte résiduelle de ces pièces pose généralement de graves problèmes pour certains types de technologie de la FA métallique. Dans un système de FA, la qualité finale d'une pièce métallique dépend de nombreux paramètres de procédé, qui sont normalement optimisés par une série d'expériences sur des machines de FA. La simulation macroscopique dédiée au procédé de FA est une alternative potentielle pour les pièces métalliques fabriquées par la fabrication additive. Dans cette thèse, nous étudions d'abord le pré-processing de la simulation de FA par la méthode des éléments finis (FEM). Le procédé de fabrication additive est un phénomène multi-physique des champs couplés (champs thermique, mécanique et métallurgique). La simulation macroscopique est réalisée à deux niveaux différents. Au niveau de la couche, la reconstruction du modèle 3D est effectuée à partir du fichier de chemin de balayage de la machine de FA, basée sur la manipulation inverse de l'algorithme d'offsetting-clipping. Au niveau de la pièce, le modèle 3D de CAO est reconstruit dans un maillage des voxels, ce qui est pratique pour une pièce avec une géométrie complexe. Avec les températures de préchauffage différentes et les paramètres du procédé différents, la contrainte résiduelle d'une pièce est analysée. Ces simulations impliquent la technique potentielle pour réduire la contrainte résiduelle par l'optimisation des paramètres du procédé, au lieu de moyens traditionnels par augmenter la température de préchauffage. Basées sur la plateforme de simulation de FEM ci-dessus, deux simulations au niveau de ligne sont également étudiées dans cette thèse, visant à la relation entre le procédé de FA et la qualité finale de la pièce. Ces exemples démontrent la possibilité d'utiliser des simulations macroscopiques pour améliorer le contrôle de la qualité pendant le procédé de FA. Dans la première tâche, l'ensemble de données des paramètres de chauffage et la contrainte résiduelle sont générés par la simulation de FA. La corrélation entre eux est étudiée en utilisant des algorithmes de régression, tel que le réseau neuronal artificiel. Dans la deuxième tâche, un contrôleur de PID pour la boucle de rétroaction puissance-température est intégré dans la simulation de procédé de FA et l'auto-réglage de PID est numériquement étudié au lieu d'utiliser la machine de FA. Les deux tâches montrent le rôle important de la simulation de procédé macroscopique de FA, qui peut remplacer ou combiner les nombreuses expériences essai-erreur dans la fabrication additive métalliqueAdditive manufacturing (AM) has become a new option for the fabrication of metallic parts in industry. However, there are still some limitations for this application, especially the unfavourable final shape and undesired macroscopic properties of metallic parts built in AM systems. The distortion or crack due to the residual stress of these parts leads usually to severe problems for some kinds of metal AM technology. In an AM system, the final quality of a metallic part depends on many process parameters, which are normally optimized by a series of experiments on AM machines. In order to reduce the considerable time consumption and financial expense of AM experiments, the numerical simulation dedicated to AM process is a prospective alternative for metallic part fabricated by additive manufacturing. Because of the multi-scale character in AM process and the complex geometrical structures of parts, most of the academic researches in AM simulation concentrated on the microscopic melting pool. Consequently, the macroscopic simulation for the AM process of a metallic part becomes a current focus in this domain. In this thesis, we first study the pre-processing of AM simulation on Finite Element Method (FEM). The process of additive manufacturing is a multi-physics problem of coupled fields (thermal, mechanical, and metallurgical fields). The macroscopic simulation is conducted in two different levels with some special pre-processing work. For the layer level, the reconstruction of 3D model is conducted from the scan path file of AM machine, based on the inverse manipulation of offsetting-clipping algorithm. For the part level, the 3D model from CAD is reconstructed into a voxel-based mesh, which is convenient for a part with complex geometry. The residual stress of a part is analysed under different preheat temperatures and different process parameters. These simulations imply the potential technique of reducing residual stress by the optimisation of process parameters, instead of the traditional way by increasing preheat temperature. Based on the FEM simulation platform above, two simulations at line level are also studied in this thesis, aiming at the relation between the AM process and part's final quality. These examples demonstrate the feasibility of using macroscopic simulations to improve the quality control during the AM process. In the first task, dataset of heating parameters and residual stress are generated by AM simulation. The correlation between them is studied by using some regression algorithm, such as artificial neural network. In the second task, a PID controller for power-temperature feedback loop is integrated into AM process simulation and the PID auto-tuning is numerically investigated instead of using AM machine. Both of the two tasks show the important role of AM macroscopic process simulation, which may replace or combine with the numerous trial and error of experiments in metal additive manufacturing
39
Joubaud, Maud. "Processus de Markov déterministes par morceaux branchants et problème d’arrêt optimal, application à la division cellulaire." Thesis, Montpellier, 2019. http://www.theses.fr/2019MONTS031/document.
Full textAbstract:
Les processus markoviens déterministes par morceaux (PDMP) forment une vaste classe de processus stochastiques caractérisés par une évolution déterministe entre des sauts à mécanisme aléatoire. Ce sont des processus de type hybride, avec une composante discrète de mode et une composante d’état qui évolue dans un espace continu. Entre les sauts du processus, la composante continue évolue de façon déterministe, puis au moment du saut un noyau markovien sélectionne la nouvelle valeur des composantes discrète et continue. Dans cette thèse, nous construisons des PDMP évoluant dans des espaces de mesures (de dimension infinie), pour modéliser des population de cellules en tenant compte des caractéristiques individuelles de chaque cellule. Nous exposons notre construction des PDMP sur des espaces de mesure, et nous établissons leur caractère markovien. Sur ces processus à valeur mesure, nous étudions un problème d'arrêt optimal. Un problème d'arrêt optimal revient à choisir le meilleur temps d'arrêt pour optimiser l'espérance d'une certaine fonctionnelle de notre processus, ce qu'on appelle fonction valeur. On montre que cette fonction valeur est solution des équations de programmation dynamique et on construit une famille de temps d'arrêt $epsilon$-optimaux. Dans un second temps, nous nous intéressons à un PDMP en dimension finie, le TCP, pour lequel on construit un schéma d'Euler afin de l'approcher. Ce choix de modèle simple permet d'estimer différents types d'erreurs. Nous présentons des simulations numériques illustrant les résultats obtenusPiecewise deterministic Markov processes (PDMP) form a large class of stochastic processes characterized by a deterministic evolution between random jumps. They fall into the class of hybrid processes with a discrete mode and an Euclidean component (called the state variable). Between the jumps, the continuous component evolves deterministically, then a jump occurs and a Markov kernel selects the new value of the discrete and continuous components. In this thesis, we extend the construction of PDMPs to state variables taking values in some measure spaces with infinite dimension. The aim is to model cells populations keeping track of the information about each cell. We study our measured-valued PDMP and we show their Markov property. With thoses processes, we study a optimal stopping problem. The goal of an optimal stopping problem is to find the best admissible stopping time in order to optimize some function of our process. We show that the value fonction can be recursively constructed using dynamic programming equations. We construct some $epsilon$-optimal stopping times for our optimal stopping problem. Then, we study a simple finite-dimension real-valued PDMP, the TCP process. We use Euler scheme to approximate it, and we estimate some types of errors. We illustrate the results with numerical simulations
40
Wang, Hao. "Characterization and Control of Molecular Contaminants on Oxide Nanoparticles and in Ultra High Purity Gas Delivery Systems for Semiconductor Manufacturing." Diss., The University of Arizona, 2013. http://hdl.handle.net/10150/293417.
Full textAbstract:
Molecular contaminants on the surface of nanoparticles (NPs) are critical in determining the environmental safety and health (ESH) impacts of NPs. In order to characterize the surface properties that relate to adsorption and desorption interactions, a method has been developed for studying the dynamic interactions of adsorbing species on NP samples. The results are analyzed using a process simulator to determine fundamental properties such as capacity, affinity, rate expressions, and activation energies of NP interactions with contaminants. The method is illustrated using moisture as a representative model compound and particles of SiO₂, HfO₂, and CeO₂, which are three oxides used in semiconductor manufacturing. The effect of particle size and temperature on the surface properties of porous oxide NPs was investigated. Infrared spectra peaks corresponding to the stretching vibration of water molecules were monitored by in-site Fourier transform infrared (FTIR) spectroscopy. These are related to the moisture concentration on the surface of NPs. A transient multilayer model was developed to represent the fundamental steps in the process. The thermal stability of adsorbed species and the strength of bonding to the surface were evaluated by determining the activation energies of the various steps. The results indicate that the surface interaction parameters are dependent on species, temperature, and particle size. SiO₂ has the highest adsorption capacity and therefore is most prone to the adsorption of moisture and similar contaminants. However, the affinity of the NPs for H₂O retention is highest for CeO₂ and lowest for SiO₂. As temperature decreases, NPs exhibit a higher saturated moisture concentration and are more prone to the adsorption of moisture and similar contaminants. Furthermore, smaller NPs have a higher saturated surface concentration and a slower response to purging and desorption. Factors contributing to the environmental and health impact of NPs (extent of surface coverage, capacity, and activation energy of retention) have been investigated during this study. The second objective of this study is to develop a method to measure and control the contamination in ultra-high-purity (UHP) gas delivery systems. Modern semiconductor manufacturing plants have very stringent specifications for the moisture content at the point-of-use, usually below several parts per billion (ppb). When the gas delivery system gets contaminated, a significant amount of purge time is required for recovery of the background system. Therefore, it is critical for high-volume semiconductor manufacturers to reduce purge gas usage as well as purge time during the dry-down process. A method consisting of experimental research and process simulations is used to compare steady-state purge (SSP) process of constant pressure and flow rate with the pressure-cycle purge (PCP) process of cyclic pressure and flow rate at a controlled interval. The results show that the PCP process has significant advantages over the SSP process under certain conditions. It can reduce the purge time and gas usage when the gas purity at point-of-use is the major concern. The process model is validated by data congruent with the experimental results under various operating conditions and is useful in conducting parametric studies and optimizing the purge process for industrial applications. The effect of key operational parameters, such as start time of PCP process as well as choice of PCP patterns has been studied.
41
Lin, Wen-Hsing. "A comprehensive computer program for the control of first-order process with time delay." Ohio : Ohio University, 1994. http://www.ohiolink.edu/etd/view.cgi?ohiou1178132732.
Full text
42
Leksawasdi, Noppol Biotechnology & Biomolecular Sciences (BABS) UNSW. "Kinetics and modelling of enzymatic process for R-phenylacetylcarbinol (PAC) production." Awarded by:University of New South Wales. Biotechnology and Biomolecular Sciences (BABS), 2004. http://handle.unsw.edu.au/1959.4/20846.
Full textAbstract:
R-phenylacetylcarbinol (PAC) is used as a precursor for production of ephedrine and pseudoephedrine, which are anti-asthmatics and nasal decongestants. PAC is produced from benzaldehyde and pyruvate mediated by pyruvate decarboxylase (PDC). A strain of Rhizopus javanicus was evaluated for its production of PDC. The morphology of R. javanicus was influenced by the degree of aeration/agitation. A relatively high specific PDC activity (328 U decarboxylase g-1 mycelium) was achieved when aeration/agitation were reduced significantly in the latter stages of cultivation. The stability of partially purified PDC and crude extract from R. javanicus were evaluated by examining the enzyme deactivation kinetic in various conditions. R. javanicus PDC was less stable than Candida utilis PDC currently used in our group. A kinetic model for the deactivation of partially purified PDC extracted from C. utilis by benzaldehyde (0?00 mM) in 2.5 M MOPS buffer has been developed. An initial lag period prior to deactivation was found to occur, with first order dependencies of PDC deactivation on exposure time and on benzaldehyde concentration. A mathematical model for the enzymatic biotransformation of PAC and its associated by-products has been developed using a schematic method devised by King and Altman (1956) for deriving the rate equations. The rate equations for substrates, product and by-products have been derived from the patterns for yeast PDC and combined with a deactivation model for PDC from C. utilis. Initial rate and biotransformation studies were applied to refine and validate a mathematical model for PAC production. The rate of PAC formation was directly proportional to the enzyme activity level up to 5.0 U carboligase ml-1. Michaelis-Menten kinetics were determined for the effect of pyruvate concentration on the reaction rate. The effect of benzaldehyde on the rate of PAC production followed the sigmoidal shape of the Monod-Wyman-Changeux (MWC) model. The biotransformation model, which also included a term for PDC inactivation by benzaldehyde, was used to determine the overall rate constants for the formation of PAC, acetaldehyde and acetoin. Implementation of digital pH control for PAC production in a well-stirred organic-aqueous two-phase biotransformation system with 20 mM MOPS and 2.5 M dipropylene glycol (DPG) in aqueous phase resulted in similar level of PAC production [1.01 M (151 g l-1) in an organic phase and 115 mM (17.2 g l-1) in an aqueous phase after 47 h] to the system with a more expensive 2.5 M MOPS buffer.
43
Propes, Nicholas Chung. "Hybrid Systems Diagnosis and Control Reconfiguration for Manufacturing Systems." Diss., Georgia Institute of Technology, 2004. http://hdl.handle.net/1853/5150.
Full textAbstract:
A methodology for representing and analyzing manufacturing systems in a hybrid systems framework for control reconfiguration purposes in the presence of defects and failures at the product and system levels is presented. At the top level, a supervisory Petri net directs parts/jobs through the manufacturing system. An object-based hybrid systems model that incorporates both Petri nets at the event-driven level and differential equations at the time-driven level describes the subsystems. Rerouting capabilities utilizing this model at the product and operation levels were explained. Simulations were performed on a testbed model for optimal time and mode transition cost to determine the route for parts. The product level reconfiguration architecture utilizes an adaptive network-based fuzzy inference system (ANFIS) to map histogram comparison metrics to set-point adjustments when product defects were detected. Tests were performed on good and defective plastic parts from a plastic injection molding machine. In addition, a mode identification architecture was described that incorporates both time- and event-driven information to determine the operating mode of a system from measured sensor signals. Simulated data representing the measured process signals from a Navy ship chiller system were used to verify that the appropriate operating modes were detected.
44
Paul, Parneet. "Using traditional modelling approaches for a MBR system to investigate alternate approaches based on system identification procedures for improved design and control of a wastewater treatment process." Thesis, De Montfort University, 2011. http://hdl.handle.net/2086/5387.
Full textAbstract:
The specific research work described in this thesis forms part of a much larger research project that was funded by the Technology Programme of the UK Government. This larger project considered improving the design and efficiency of membrane bioreactor (MBR) plant by using modelling, simulation and laboratory methods. This research work uses phenomenological mechanistic models based on MBR filtration and biochemical processes to measure the effectiveness of alternative behavioural models based upon input-output system identification methods. Both model types are calibrated and validated using similar plant layouts and data sets derived for this purpose. Results prove that although both approaches have their advantages, they also have specific disadvantages as well. In conclusion, the MBR plant designer and/or operator who wishes to use good quality, calibrated models to gain a better understanding of their process, should carefully consider which model type is selected based upon on what their initial modelling objectives are (e.g. using either a physically mechanistic model or an input-output behaviourial model). Each situation usually proves unique. In this regard, this research work creates a "Model Conceptualisation Procedure" for a typical MBR which can be used by future researchers as a theoretical framework which underpins any newly created model type. There has been insufficient work completed to date on using a times series input-output approach in the model development of a wastewater treatment plant, so only general conclusions can be made from this research work. However, it can be stated that this novel approach seems to be applicable for a membrane filtration model if care it taken to select appropriate input-output model structures, such as those suggested in the "Model Conceptualisation Procedure". In the case of the development of a MBR biological model, it is thought that a conventional Activated Sludge model produced by the IWA could be coupled to a input-output model structure as suggested by this report to give a hybrid model structure that may have the advantages of both model types. Further research work is needed in this area. Future work that should follow on from this research study should focus on whether these input-output models could be used for predictive control purposes, whether an integrated model could be created, and whether a benchmark could be created for the three main MBR configurations.
45
Silva, Bruno Firmino da 1989. "Desenvolvimento e avaliação de sistemas de controle plantwide aplicados na produção de biodiesel." [s.n.], 2015. http://repositorio.unicamp.br/jspui/handle/REPOSIP/266023.
Full textAbstract:
Orientadores: Flávio Vasconcelos da Silva, Jones Erni SchmitzDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Química
Made available in DSpace on 2018-08-27T17:33:20Z (GMT). No. of bitstreams: 1 Silva_BrunoFirminoda_M.pdf: 5897961 bytes, checksum: ac5990dc3d98f600c8592ed2ea843e04 (MD5) Previous issue date: 2015
Resumo: Os processos químicos apresentam dinâmicas complexas devido a presença de reciclos, integrações energéticas e diversas operações unitárias interconectadas, gerando problemas de interação entre as variáveis e dificultando um efetivo controle do processo. Metodologias de controle global ou plantwide buscam estabelecer sistemas de controle contemplando a planta química como um todo, porém, geram mais de uma solução de controle. Este trabalho propõe avaliar diferentes estruturas de controle global para uma mesma planta química através do uso de indicadores chave de desempenho (KPI ¿ Key Performance Indicator) para o processo, determinando assim qual sistema de controle melhor atende aos objetivos estratégicos da indústria. Como caso de estudo simulou-se uma planta típica para a produção de biodiesel através dos softwares Aspen Plus e Aspen Plus Dynamics. O processo implementado busca representar a produção do biocombustível obtido na transesterificação do óleo de soja com metanol, por meio da rota de catálise alcalina e homogênea. Para simulação dinâmica do processo, utilizaram-se dois conjuntos de controladores obtidos da metodologia de controle global heurística, configurando-se duas propostas de controle para o processo. Para avaliação das propostas de controle, utilizaram-se indicadores chave de desempenho representativos do processo global. O indicador DDS (Dynamic Disturbance Sensitivity), o qual relaciona o acúmulo molar total dos componentes ao longo do tempo, e um indicador que relaciona os custos de matérias-primas foram utilizados. Ambos indicadores, permitiram uma visualização do desempenho dos controladores de modo global e a auxiliaram na escolha do melhor conjunto de malhas de controle para o processo
Abstract: Chemical process have complex dynamics behaviors due to the presence of recycle streams, heat integration and several unit operations interconnected, leading to interaction problems among variables and making difficult to do an effective process control. Plantwide control methodologies aim to establish controls systems for entire chemical plants; however, it is possible to obtain different control solutions. This work proposes an evaluation of different Plantwide control structures for a specific process using Key Performance Indicators (KPI) and determinate which structure best meets the industry strategic goals. As a case study, it was implemented a simulation of a typical biodiesel process in Aspen Plus and Aspen Plus Dynamics. The process implemented intended to represent the production of biofuel obtained from the transesterification of soybean oil with methanol and homogeneous alkaline catalysis as chemical route. For dynamic simulation of the process, two sets of controllers obtained using global control heuristic methodology were used to control the process, setting up two proposals of control for biodiesel production. Key performance indicators of the overall process were used to evaluate the control proposals, such as the DDS indicator (Dynamic Disturbance Sensitivity), which presents the total molar accumulation over time, and an indicator that presents the raw material costs also over time. Both indicators allowed a view of the controllers global performance and aided in choose the best set of control loops for the process
Mestrado
Sistemas de Processos Quimicos e Informatica
Mestre em Engenharia Química
46
Guzman, Pamela, Franklin Montalvo, Edgardo Carvallo, and Carlos Raymundo. "Implementation of a process management model and inventory control to increase the level of service in the after-sales area of industrial equipment." Latin American and Caribbean Consortium of Engineering Institutions, 2019. http://hdl.handle.net/10757/656260.
Full textAbstract:
Currently, many industrial companies generate many losses in their after sales this is generated to an error in the control of inventories and in turn in a mishandling of their assets through their processes, therefore the present research proposes a management model of processes and control of inventories in order to reduce customer losses due to the large number of existing complaints and thus increase sales. Therefore, the process management model, which will contribute to the standardization, optimization and control of its critical processes, and for which indicators, procedures and policies will be proposed for each stage of the process in order to measure its efficiency and effectiveness for correct decision making. With respect to the control of inventories, it is proposed to make a segmentation of the products, which allows the identification of the most important products for the company, to then design a demand forecast model for families of products that will later be individualized considering their factors initial and finally using an inventory management model will obtain the optimal quantity of spare parts order to use in the technical service of the equipment reducing the annual costs related to the inventory.
47
Pires, Carlos Augusto de Moraes. "Reforma catalitica da nafta : modelagem, simulação e controle do processo." [s.n.], 2000. http://repositorio.unicamp.br/jspui/handle/REPOSIP/267566.
Full textAbstract:
Orientadores: João Alexandre F. R. Pereira, Maria de Fatima dos S. LopesTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Quimica
Made available in DSpace on 2018-07-26T19:33:57Z (GMT). No. of bitstreams: 1 Pires_CarlosAugustodeMoraes_D.pdf: 5756765 bytes, checksum: 2dc4d2764d6474896a777d6ffc991d18 (MD5) Previous issue date: 2000
Resumo: O processo de refonna catalítica da nafta, voltado para a produção de compostos aromáticos (benzeno, tolueno e xilenos), foi o tema abordado neste estudo. Considerou-se um típico processo semi-regenerativo, no qual existem quatro reatores radiais em série intercalados com quatro fornalhas que são utilizadas para aquecer as correntes que alimentam os reatores. A modelagem dos reatores foi proposta para os regimes estacionário e transiente e foi considerado um sistema reacional simplificado, envolvendo apenas dez compostos químicos relacionados através de cinco reações. A desativação do catalisador faz parte do modelo cinético e a expressão da taxa de fonnação de coque é baseada na condensação do aromático. Este modelo foi simulado a partir de um programa de computador construí do em linguagem FORTRAN, chegando-se a resultados compatíveis com os encontrados em literatura. Desta fonna, foi possível efetuar um estudo sobre os efeitos das variáveis operacionais nas concentrações dos produtos deste processo e várias conclusões importantes foram obtidas. Após analisar as relações entre os produtos originários da refonna com as variáveis operacionais, foi proposta uma estratégia de controle em cascata para manter a concentração de aromático no "setpoint" desejado. O objetivo da aplicação desta estratégia de controle é o de compensar os efeitos da desativação do catalisador, bastando para isso aumentar a temperatura da corrente de entrada dos reatores. A malha secundária, do controle em cascata, controla a temperatura de entrada dos reatores. Foram utilizados os controladores PID, DMC e LDMC no intuito de verificar o melhor desempenho desta malha. Estes controladores foram elaborados em linguagem FORTRAN e através da simulação destes casos foram obtidas infonnações que pennitiram concluir que o controlador LDMC é o mais apropriado. Para a malha primária, que controla a concentração de aromático, impondo as temperaturas ótimas de entrada para cada reator (setpoints" da malha secundária), foi utilizado o controlador LDMC com duas opções de configuração para a matriz dinâmica. A primeira opção considera o sistema como sendo de múltiplas entradas e única saída (MISO), com as temperaturas representando as variáveis manipuladas e a concentração de aromático a controlada. A segunda opção supõe que o sistema possui única entrada e única saída (SISO), a variável manipulada é a W AIT (que é a soma ponderada das temperaturas de entrada dos reatores, levando em conta a quantidade de catalisador em cada um dos leitos) e a variável controlada é a concentração de aromático. Observa-se que não houve diferença significativa entre estas duas opções para a malha primária, notando-se apenas uma ligeira vantagem para o caso MISO em função da maior atividade do catalisador. Como conclusão deste trabalho, foi possível verificar os vários aspectos da refonna catalítica da nafta inerentes ao processo de obtenção de aromáticos. Entretanto, outras pesquisas nesta linha devem ser realizadas para conseguir, dentre outras coisas, diminuir a defasagem existente de infonnações entre a tecnologia atual e a teoria disponível, sendo que esforços como este devem ser incentivados para obtenção de mais conhecimentos sobre o processo
Abstract: The theme of this study is the process of catalytic refonning for aromatics (benzene, toluene and xilenes). There were considered a typical semiregenerative process, with serial arrange of four radial reactors preceded by four furnaces used to pre-heat the reactors feed. There were proposed stationary and transient for the reactors. A simplified reacctional system were considered, involving only ten chemical compounds related through five reactions. The kinetic model inc1ude the deactivation of the catalyst and the rate of coke fonnation is based on aromatic condensation. The model was simulated in a computer FORTRAN code and the achieved results are compatible with the literature ones. It was then possible to study the effects of operational variables in the products concentrations and several important conclusions were obtained. The relationship among the reforming process products with operational variables were analyzed and a cascade control strategy was proposed to maintain the aromatic concentration in the desired set point. The objective of this control strategy is to compensate the catalyst deactivation effects, and its only action is to increase the temperature of the feed reactors. The secondary loop in the cascade control strategy controls the temperature of the feed ofthe reactors. Controllers PID, DMC and LDMC were tested in order to verify which is the one what maximizes the loop performance. The controllers were programmed in a FORTRAN code and the simulation results shows that the controller LDMC is the most appropriate. For the primary loop, which controls the aromatic concentration, imposing the optimal temperature in each reactor feed ( set point of secondary loop) the controller LDMC was used with two possible configuration of the dynamic matrix. The first option considers the system with multiple entrances and only a exit (MISO), with the temperatures representing the manipulated variables and the aromatic concentration as the controlled one. The second option supposes that the system has only one entrance and only one exit (SISO). The manipulated variable is WAIT (weighted average inlet temperature) the controlled variable is also the aromatic concentration. Both options for primary loop are equivalent, the MISO options is slightly better than the often one because of largest catalyst activity. In this work, it was verified several aspects inherent of catalytic naphtha refonning process for the production of aromatics. Other researches in this line should he done in order to reduce the existent gap of information between current technology and available theory, and other efforts should be motivated for obtaining a better knowledge of the processo
Doutorado
Sistemas de Processos Quimicos e Informatica
Doutor em Engenharia Química
48
Wenzel, Anne. "Erstellung eines Modells zum Abruf positiver Minutenreserve." Bachelor's thesis, Universitätsbibliothek Chemnitz, 2011. http://nbn-resolving.de/urn:nbn:de:bsz:ch1-qucosa-66418.
Full textAbstract:
Im Rahmen der Arbeit wurden die Daten für Minutenreserveabrufe in den Jahren 2006 und 2007 nach Regelzonen analysiert und ein stochastisches Modell erstellt. Die detaillierte Analyse der Minutenreserveabrufe ergab eine Tageszeitabhängigkeit des Auftretens von Abrufen. In den Nachtstunden erfolgten sehr wenige bis keine Abrufe. Die jeweils abgerufenen Mengen lassen ebenfalls eine Tageszeitabhängigkeit erkennen. Auffällig war, dass die Minutenreserveabrufe in der RWE-Regelzone signifikant anders als in den übrigen Regelzonen erfolgten.
Für die Modellbildung wurde ein zusammengesetzter Poisson-Prozess gewählt. Die Intensität λ blieb dabei konstant. Um die Tageszeitabhängigkeit einfließen zu lassen, wurde angenommen, dass die Mengen pro Abruf einer Normalverteilung mit tageszeitabhängigen Parametern μ und σ gehorchen. Mit Hilfe des Modells erfolgten Simulationen von Minutenreser-veabrufen für jede Regelzone. Zur Verifikation des Modells wurden die simulierten Abrufe mit den real eingetretenen Abrufen im Jahr 2008 verglichen. In Intensität der Abrufhäufigkeit und im Erwartungswert der Abrufmengen decken sich die Simulationen sehr gut mit der Realität (siehe Abbildung). Unter Anwendung des Modells lassen sich vielfältige Berechnungen beispielsweise zum Einsatz dezentraler KWK-Anlagen durchführen. In naher Zukunft ist die Er-weiterung des Modells um das in der Realität häufig eintretende Ereignis mehrerer direkt aufeinander folgender Abrufe in etwa derselben Höhe oder auch die Betrachtung negativer Minutenreserve wünschenswert.
49
Pimenta, Luciana Bispo. "Simulação dinâmica de planta de condicionamento de gás natural em plataforma offshore." [s.n.], 2011. http://repositorio.unicamp.br/jspui/handle/REPOSIP/266786.
Full textAbstract:
Orientador: Maria Regina Wolf MacielDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Química
Made available in DSpace on 2018-08-19T10:31:27Z (GMT). No. of bitstreams: 1 Pimenta_LucianaBispo_M.pdf: 3231978 bytes, checksum: c2de8436ce07b62fabe1af47e5020ef1 (MD5) Previous issue date: 2011
Resumo: O comportamento dinâmico em unidades de produção de óleo é muito importante para a operação e projeto de equipamentos. O desenvolvimento da tecnologia no processamento primário de petróleo é caracterizado pela otimização de peso e espaço nas unidades de produção. Estas restrições têm sido diretrizes para pesquisas em desenvolvimento de equipamentos mais eficientes e compactos, como hidrociclones. Porém, esta capacidade de compactar equipamentos resultou em redução na flexibilidade em operar com oscilações de carga (golfadas). Ao longo dos últimos anos, a maturação de campos produtores e o aumento na produção de água e no uso de gás lift associados à produção de óleo em lâminas d'água cada vez mais profundas têm aumentado a freqüência de golfadas. A simulação dinâmica pode ser utilizada para desenvolver estratégias para controlar situações transientes em plataformas offshore. Este trabalho utilizou a simulação dinâmica de uma planta de condicionamento de gás natural em plataforma offshore feita no simulador de processos HYSYS 7.2, como ferramenta para analisar a planta e propor melhores condições de operação. Neste trabalho duas situações serão analisadas. Na primeira, apenas o gás associado passa pelo sistema de compressão e o gás não associado é encaminhado diretamente para desidratação com TEG (situação 1). Na segunda, haverá uma quebra de pressão do gás proveniente dos poços de gás e este deverá ser encaminhado para o sistema de compressão juntamente com o gás proveniente dos poços de óleo (situação 2). Em um primeiro momento, a planta foi analisada em modelo de estado estacionário e foi avaliado o efeito da quebra de pressão na temperatura da tubulação à jusante das válvulas responsáveis pela quebra (situação 2). Em um segundo momento, a planta foi avaliada no estado dinâmico, onde foi possível analisar o efeito que as oscilações de carga têm no sistema de compressão da planta, bem como nas trocas térmicas. Este segundo estudo foi avaliado para as situações 1 e 2. Para o estudo em estado estacionário, foi possível observar que a especificação de temperatura mínima de projeto para a tubulação à jusante das válvulas que efetuam a quebra de pressão não é alcançada, porém, existe uma faixa de ?P ideal para cada válvula a fim de evitar a formação de gelo na parte externa da tubulação. Para o estudo dinâmico foi possível avaliar os efeitos que as oscilações de carga trazem para o sistema de compressão e em que situação (1 ou 2) a planta opera com maior estabilidade. Verificou-se que o trocador da saída do sistema de compressão opera com certa instabilidade na situação 1 devido à baixa vazão de gás a ser resfriado e na situação 2 esta instabilidade é reduzida. As conclusões deste estudo mostram a importância da simulação dinâmica como ferramenta de decisão para o engenheiro de processamento de gás na operação da planta
Abstract: Dynamic behavior in oil production units is vital for equipments project and operation. Technology development in offshore primary processing has traditionally been characterized by optimizing weight and space in their production units. Such restrictions have been the guidelines for researches in developing more efficient and compact equipments, such as hydro cyclones. However, this compactness has resulted, invariably, in reduced capacity to deal with load oscillations, typical in offshore units. Along the last years the maturation of production fields, and the increase of water production and gas lift use, associated to the oil production in larger and larger water depths have been increasing slugs intensity. Dynamic simulation can be used to develop better strategies to control transient situations in offshore units. This study use a dynamic simulation of a natural gas offshore conditioning plant as a tool to analyze the plant and to propose better operational conditions. The process simulator to do dynamic simulation was HYSYS 7.2. In this work two situations were analyzed. In the first one, only the gas from oil wells pass through the gas compression system and the gas from gas wells are forwarded directly to dehydration with TEG (situation 1). In the second situation, there will be a pressure drop of the gas from gas wells and this gas should be forwarded to the compression system along with gas from oil wells (situation 2). At first, the plant was analyzed in steady state model and the effect of pressure drop in pipe temperature downstream of the valves responsible for pressure drop was evaluated (situation 2). In a second stage the plant was evaluated in dynamic state where it was possible to analyze the effect of load oscillations in the compression system, as well as in the heat exchange. This second study was evaluated for situations 1 and 2. For the static study, the specification of minimum project temperature for the pipeline downstream of the valves that perform the pressure drop is not achieved but there is an ideal range pressure drop for each valve to prevent ice formation outside the pipe. In the dynamic study was evaluated the effects of load oscillations in compression system and in what situation (1 or 2) the plant operates with greater stability. It was found that the heat exchange of the output of the compression system operates with instability in the situation 1 due to the low flow of gas to be cooled, and in the situation 2 this instability is reduced. The conclusions of this study show the importance of dynamic simulation as a decision tool for the engineer in the gas processing plant operation
Mestrado
Desenvolvimento de Processos Químicos
Mestre em Engenharia Química
50
Rosa, Eduardo Ledoux. "Projeto de controle e otimização de um sistema de geração de vapor com múltiplas caldeiras com simulação dinâmica." Universidade Tecnológica Federal do Paraná, 2013. http://repositorio.utfpr.edu.br/jspui/handle/1/688.
Full textAbstract:
Este trabalho propõe desenvolver um projeto de controle de um sistema de geração de vapor composto por múltiplas caldeiras que contemple a otimização do consumo de combustível do sistema. Para atingir este objetivo, deve-se combinar um controle regulatório eficiente de uma caldeira e um mecanismo divisor de carga eficiente para que cada caldeira opere com a confiabilidade normalmente requerida, aliado a um ponto ótimo de consumo de combustível. Esta dissertação apresenta: a modelagem dinâmica de uma caldeira aquatubular industrial; a implementação computacional do modelo dinâmico de uma caldeira aquatubular em Matlab; o projeto de controle de uma caldeira aquatubular no sistema de automação 800xA envolvendo a definição de estratégias de controle, a comunicação do sistema de automação com o modelo da planta no Matlab, uma avaliação sobre algumas técnicas de sintonia, bem como a sua simulação dinâmica e resultados; o problema de otimização para minimização do consumo de total de combustível de um sistema de geração de vapor com múltiplas caldeiras, bem como a avaliação de sua resolução com modelagem por uma abordagem de Programação Linear Inteira Mista; e o projeto de controle de um sistema com múltiplas caldeiras, envolvendo também a simulação dinâmica. Com base nos experimentos simulados considerou-se que a estratégia de controle proposta neste trabalho tem desempenho satisfatório, principalmente pelo fato de que a inclusão do bloco divisor de carga não acarretou prejuízo na característica de rejeição de perturbações, o que encoraja estudos posteriores com o objetivo de se ter uma utilização prática.This study proposes to develop a control project for a multiple boilers steam generation system that includes fuel optimization. To achieve that, it must combine an efficient boiler regulatory control and an efficient mechanism for load allocation to each boiler in order to operate with normally required reliability and combined with optimum fuel consumption. This dissertation presents: dynamic modeling of an industrial watertube boiler; computational implementation of the dynamic watertube Boiler model in Matlab, the control design of a watertube Boiler in 800xA automation system involving the definition of control strategies, communication of the 800xA automation system with the plant model in Matlab, an evaluation of some techniques for PID tuning including dynamic simulation results, the optimization problem to minimize the total fuel consumption of a multiple boilers steam generation system, as well as the assessment of their resolution with Mixed Integer Linear Programming modeling approach, and control design of a multiple boilers system, also involving dynamic simulation. Based on simulated experiments it was found that the control strategy proposed in this work has satisfactory performance, mainly because of the inclusion of the divider block load did not affect the rejection of disturbances characteristic, which encourages further studies with objective of practical use.