Nowadays, computers are extensively used in engineering modeling and simulation fields in many different ways, one of which is in chemical engineering. Simulation and modeling of a chemical process plant and the sizing of the equipment with the assistance of computers, is of special interests to process engineers and investors. This is due to the ability of high speed computers, which make millions of mathematical calculations in less than a second associated with the new powerful software that make the engineering calculations more reliable and precise by making very fast iterations in thermodynamics, heat and mass transfer calculations. This combination of new technological hardware and developed software enables process engineers to deal with simulation, design, optimization, control, analysis etc. of complex plants, e.g. refinery and petrochemical plants, reliably and satisfactorily. The main chemical process simulators used for static and dynamic simulations are ASPEN PLUS, ASPEN HYSYS, PRO II, and CHEMCAD. The basic design concepts of all simulators are the same and one can fairly use all simulators if one is expert in any of them. Hydrogenation process is an example of the complex plants, to which a special attention is made by process designers and manufacturers. This process is used for upgrading of hydrocarbon feeds containing sulfur, nitrogen and/or other unsaturated hydrocarbon compounds. In oil and gas refineries, the product of steam cracking cuts, which is valuable, may be contaminated by these unwanted components and thus there is a need to remove those pollutants in downstream of the process. Hydrogenation is also used to increase the octane number of gasoline and gas oil. Sulfur, nitrogen and oxygen compounds and other unsaturated hydrocarbons are undesired components causing environmental issues, production of by-products, poisoning the catalysts and corrosion of the equipment. The unsaturated C=C double bonds in dioleffinic and alkenyl aromatics compounds, on the other hand, cause unwanted polymerization reactions due to having the functionality equal to or greater than 2. Hydrogenation process of the undesired components will remove those impurities and/or increase the octane number of aforementioned hydrocarbons. This process is sometimes referred to as “hydrotreating”; however, “upgrader” is a general word and is, of course, of more interest. In this thesis, a hydrogenation process plant was designed on the basis of the chemistry of hydrocarbons, hydrogenation reaction mechanism, detailed study of thermodynamics and kinetics and then a steady-state simulation and design of the process is carried out by ASPEN HYSYS 2006 followed by design evaluation and some modifications and conclusions. Hydrogenation reaction has a complicated mechanism. It has been subjected to hot and controversial debates over decades. Many kinetic data are available, which contradict one another. Among them, some of the experimental researches utilize good assumptions in order to simplify the mechanism so that a “Kinetic Reaction” modeling can be employed. This thesis takes the benefit of such research works and applies some conditions to approve the validity of those assumptions. On the basis of this detailed study of reaction modeling and kinetic data, a hydrogenation plant was designed to produce and purify over 98 million kilograms of different products; e.g. Benzene, Toluene, Iso-octane etc. with fairly high purity.

Nowadays, computers are extensively used in engineering modeling and simulation fields in many different ways, one of which is in chemical engineering. Simulation and modeling of a chemical process plant and the sizing of the equipment with the assistance of computers, is of special interests to process engineers and investors. This is due to the ability of high speed computers, which make millions of mathematical calculations in less than a second associated with the new powerful software that make the engineering calculations more reliable and precise by making very fast iterations in thermodynamics, heat and mass transfer calculations. This combination of new technological hardware and developed software enables process engineers to deal with simulation, design, optimization, control, analysis etc. of complex plants, e.g. refinery and petrochemical plants, reliably and satisfactorily. The main chemical process simulators used for static and dynamic simulations are ASPEN PLUS, ASPEN HYSYS, PRO II, and CHEMCAD. The basic design concepts of all simulators are the same and one can fairly use all simulators if one is expert in any of them. Hydrogenation process is an example of the complex plants, to which a special attention is made by process designers and manufacturers. This process is used for upgrading of hydrocarbon feeds containing sulfur, nitrogen and/or other unsaturated hydrocarbon compounds. In oil and gas refineries, the product of steam cracking cuts, which is valuable, may be contaminated by these unwanted components and thus there is a need to remove those pollutants in downstream of the process. Hydrogenation is also used to increase the octane number of gasoline and gas oil. Sulfur, nitrogen and oxygen compounds and other unsaturated hydrocarbons are undesired components causing environmental issues, production of by-products, poisoning the catalysts and corrosion of the equipment. The unsaturated C=C double bonds in dioleffinic and alkenyl aromatics compounds, on the other hand, cause unwanted polymerization reactions due to having the functionality equal to or greater than 2. Hydrogenation process of the undesired components will remove those impurities and/or increase the octane number of aforementioned hydrocarbons. This process is sometimes referred to as “hydrotreating”; however, “upgrader” is a general word and is, of course, of more interest. In this thesis, a hydrogenation process plant was designed on the basis of the chemistry of hydrocarbons, hydrogenation reaction mechanism, detailed study of thermodynamics and kinetics and then a steady-state simulation and design of the process is carried out by ASPEN HYSYS 2006 followed by design evaluation and some modifications and conclusions. Hydrogenation reaction has a complicated mechanism. It has been subjected to hot and controversial debates over decades. Many kinetic data are available, which contradict one another. Among them, some of the experimental researches utilize good assumptions in order to simplify the mechanism so that a “Kinetic Reaction” modeling can be employed. This thesis takes the benefit of such research works and applies some conditions to approve the validity of those assumptions. On the basis of this detailed study of reaction modeling and kinetic data, a hydrogenation plant was designed to produce and purify over 98 million kilograms of different products; e.g. Benzene, Toluene, Iso-octane etc. with fairly high purity.

In 1970&rsquo / s, significant shifts occurred both in planning and design theories as a response to the decreasing role of state in property relations and widening arena of private property. This shift in planning approaches led to an increase in the importance of &lsquo / flexibility&rsquo / concept. However this study proposes that flexibility in the control of spatial development is not an indisputable solution, but rather it is a dilemma. This is because / the definition, degree and effect of flexibility may change in every step of the process depending on the actors in the process. While it may be a way of solution in one case, it may be the problem itself in another. In the study, this dilemma is discussed in the context of spatial development in science parks. The concept of flexibility has a particular importance in respect to science parks which host especially technology based firms. Due to market changes and technology shifts, the spatial requirements of market and also the tenants change in time rapidly. That is why flexibility becomes a necessary tool in the physical planning of science parks. In this context, firstly the role flexibility in different planning and decision-making approaches is discussed. Then the structural characteristics of science parks and specifically METU Technopolis are defined. Within this framework, the physical development process of METU Technopolis and the role of flexibility in planning and decision making processes is examined. Finally some suggestions for controlling the flexibility in planning and design processes are developed.

Combination of high strength with light weight which is the prominent property of aluminum alloy forgings has led aluminum forgings used in rapidly expanding range of applications. In this study, to produce a particular 7075 aluminum alloy part, the forging process has been designed and analyzed. The forging process sequence has been designed by using Finite Volume Method. Then, the designed process has been analyzed by using Finite Element Method and the stress, strain and temperature distributions within the dies have been determined. Five different initial temperatures of the billet / 438, 400, 350, 300 and 250 degree Celsius have been considered in the thermo-mechanically coupled simulations. The initial temperatures of the dies have been taken as 200 degree Celsius for all these analyses. Finite volume analysis and finite element analysis results of the preform and finish part have been compared for the initial billet temperature of 400 oC. Close results have been observed by these analyses. The experimental study has been carried out for the range of the initial billet temperatures of 251&amp / #8211 / 442 degree Celsius in METU-BILTIR Center Forging Research and Application Laboratory. It has been observed that the numerical and the experimental results are in good agreement and a successful forging process design has been achieved. For the initial die temperature of 200 degree Celsius, to avoid the plastic deformation of the dies and the incipient melting of the workpiece, 350 degree Celsius is determined to be the appropriate initial billet temperature for the forging of the particular part.

Assistive technologies (AT) are the products provided to elderly and disabled people to enable them to live more independently. Despite their ability to help maintain independence and prevent injury, the literature discussed within this thesis indicates that assistive technologies are not meeting the needs of the end-user. In response, research has been undertaken with the following objectives: 1. To identify how and why assistive technology products are failing to satisfy the customer. 2. To establish if a design tool can be created that overcomes the issues identified in the inductive research and which enables companies to design customer-satisfying assistive technology products. In progressing these objectives, two phases of research were planned. The first comprised four parallel studies (focus groups, case studies, questionnaires and a literature study), which together examined the state of AT products and the product-development activities of AT manufacturers. The second phase of research examined four customer-focused product design methods for their suitability for utilisation by small companies within the AT sector. On finding that no method in its entirety was suitable, a customer-focused design tool for small AT companies was developed. The resulting tool comprises eight elements for application in the initial stages of the product development process. The tool was tested in four separate studies, which examined its usability and acceptability to AT companies and which gave further insights into the AT sector. The research both finds that AT products are failing the customer in five areas and that manufacturers are contributing to this failure through a lack of customer-focus in their design processes. In addition to identifying the market research and product development activities of small AT companies, a key contribution to knowledge resulting from the research is the concept of sectoral readiness for methods of design. In its conclusion the thesis finds that the two research objectives have been met.

For long, industrial archaeological buildings were perceived as unaesthetic objects abandoned at the core of cities, inhibiting spatial and economic development. Much of the industrial heritage were demolished under the modernization discourses of the governments, and as the effects of urbanization and globalization movements. However, especially after the mid-20th century, the issue of conserving the industrial heritage, which was initiated as a disciplinary movement, caused to a change of the mentality in developed societies, which aimed the demolishment of these buildings. In these societies many developments occurred for conserving the industrial heritage. Today, many nations perceive this heritage as a tool of social, spatial and economic development of cities. On the other hand, Maltepe Gas and Electric Factory, which was listed in 1991, still cannot be regenerated since this date. The main aim of this thesis is to clarify the problems that lie behind the conservation problem of Maltepe Gas and Electric Factory landscape, and to propose solutions for the regeneration of the site. The thesis, also aims to put forth the industrial archaeological history of Ankara, to emphasize the significance of this industrial complex. In doing so, after designationg the industrialization history of the city, industrial-spatial evolution of the Maltepe Gas and Electric Factory had been discussed. Then, after clarifying the problems that threaten the regeneration of the landscape, solutions were seeked from the experiences of post-industrial countries. At the end of the thesis, based on the local context, a solution is proposed for the regeneration of the landscape in the framework of conserving the industrial archaeological heritage.

Designers are challenged to manage customer, technology, and socio-economic uncertainty causing dynamic, unquenchable demands on limited resources. In this context, increased concept flexibility, referring to a designer s ability to generate concepts, is crucial. Concept flexibility can be significantly increased through the integrated design of product and material concepts. Hence, the challenge is to leverage knowledge of material structure-property relations that significantly affect system concepts for function-based, systematic design of product and materials concepts in an integrated fashion. However, having selected an integrated product and material system concept, managing complexity in embodiment design-processes is important. Facing a complex network of decisions and evolving analysis models a designer needs the flexibility to systematically generate and evaluate embodiment design-process alternatives. In order to address these challenges and respond to the primary research question of how to increase a designer s concept and design-process flexibility to enhance product creation in the conceptual and early embodiment design phases, the primary hypothesis in this dissertation is embodied as a systematic approach for integrated product, materials and design-process design. The systematic approach consists of two components i) a function-based, systematic approach to the integrated design of product and material concepts from a systems perspective, and ii) a systematic strategy to design-process generation and selection based on a decision-centric perspective and a value-of-information-based Process Performance Indicator. The systematic approach is validated using the validation-square approach that consists of theoretical and empirical validation. Empirical validation of the framework is carried out using various examples including: i) design of a reactive material containment system, and ii) design of an optoelectronic communication system.

Dans un contexte de réduction des émissions de gaz à effet de serre (GES) et de forte volatilité du prix des énergies, les investissements en efficacité énergétique des sites industriels résultent souvent d'un processus de décision complexe. L'industriel doit pouvoir disposer d'outils lui permettant d'élaborer les solutions d'efficacité énergétique envisageables sur son site. Outre la recherche des sources d'énergie alternatives, que sont les énergies renouvelables, qui n'atteindront leur maturité technologique que sur le long terme, une solution à court terme consiste plutôt à favoriser une utilisation plus rationnelle de l'énergie. Pour relever ce défi, l'analyse exergétique apparaît comme un outil très efficace, car elle permet d'identifier précisément les sources d'inefficacité d'un procédé donné et de proposer des solutions technologiques visant à y remédier. Malheureusement, contrairement au concept d'enthalpie traditionnellement utilisé pour réaliser des bilans énergétiques sur un procédé, ce concept demeure assez difficile à appréhender et n'est que très rarement implémenté dans les simulateurs de procédés. Les travaux présentés dans ce document visent d'abordà rendre l'analyse exergétique plus accessible en l'intégrant dans un simulateur de procédés, puis à démontrer la pertinence d'une telle analyse pour l'amélioration de l'efficacité des procédés et des utilités associées. Dans un premier temps, une formulation générique et indépendante du choix du modèle thermodynamique pour l'évaluation de l'exergie des flux de matière est introduite. Une méthode de calcul des différentes contributions de l'exergie (contributions thermique, mécanique et chimique) est développée et un nouveau concept visant à évaluer les potentiels de récupérations thermique et mécanique maximales est introduit. Par la suite, la notion de bilan exergétique sur un système donné (opération unitaire ou procédé complet) est introduite. Pour l'évaluation des exergies des flux de travail et de chaleur, deux cas de figure sont étudiés : le cas de l'amélioration de procédés existants (« retrofitting ») et le cas de la conception de nouveaux procédés (« design»). Dans le cas de l'amélioration de procédés existants et afin d'aider au diagnostic énergétique de ces systèmes, des tableaux synthétiques proposant des solutions technologiques visant à réduire les irréversibilités ou les pertes exergétiques externes du procédé sont proposés. Par ailleurs, après une analyse comparative des différentes formulations d'efficacité exergétiques existant dans la littérature, la notion d'efficacité intrinsèque est retenue comme le critère le plus adapté pour une optimisation de l'efficacité exergétique d'un procédé complexe. Enfin, une nouvelle méthodologie structurée dédiée à l'analyse exergétique et permettant de pallier les lacunes des méthodologies existantes est présentée. L'ensemble de ces concepts est implémenté dans un premier prototype logiciel écrit en langage VBScript et intégré au simulateur de procédés ProSimPlus. Enfin, l'efficacité de la procédure est démontrée à travers une étude de cas portant sur la production de gaz naturel. / Energy issue is becoming increasingly crucial for industrial sector that consumes large quantities of utilities. Although the scientific world should continue to look for alternate sources of energy, a short-term solution would rather rely on a more rational use of energy. To face this challenge, exergy analysis appears a very efficient tool as it would enable to increase efficiency and reduce environmental impact of industrial processes. Unfortunately, contrary to enthalpy, this concept is rather difficult to handle and exergy analysis is rarely implemented in process simulators. In this context, the major objective of the study presented in this dissertation is to make exergy analysis more understandable by coupling it with the use of a process simulator and also to demonstrate the value of this approach for analysis of energy efficiency of processes and utilities. This dissertation presents a generic formulation for exergy of material streams that does not depend on the thermodynamic model, so that it could be easily implemented in a process simulator. The different contributions of exergy (thermal, mechanical and chemical) have been developed and new concept such as the maximal thermal and mechanical recovery potential has been introduced in order to pave the way for exergy analysis. The formulations of exergy balances on a real process are presented. For that purpose, the formulation of exergy for heat and work flux is developed. The formulation of exergy balances has been introduced for both design and retrofit situations and then a set of hints for the interpretation of this exergy balance has been given. Synthetic tables providing solutions to reduce irreversibilities and external losses have been introduced. Moreover, different kinds of exergy efficiency have been defined to provide a new criterion for the optimization of the process. A new structured methodology for exergy analysis is developed to overcome the limitations of existing methodologies. To make exergy analysis easier for any engineer, a first prototype has been developed to implement the calculation of exergy for the material streams in a process flowsheet modeled in ProSimPlus. Thanks to this prototype, exergy of each material stream appears in a synthesis table next to the traditional thermodynamic values such as the enthalpy. Finally, a case study on Natural Gas Liquids recovery process is presented to demonstrate the benefit of the exergy analysis for the improvement of existing processes. First, the exergy analysis permits to make an energy diagnosis of the process: it pinpoints the inefficiencies of the process which relies not only on irreversibilities but also on external exergy losses. Then, based upon respective values of internal and external losses and also thanks to the breaking down of exergy into it thermal, mechanical and chemical contributions, some technological solutions are suggested to propose a retrofit process. Finally, the exergy efficiency criteria enable to optimize the operating parameters of the process in order to improve its energy efficiency.

Made available in DSpace on 2014-12-17T15:01:14Z (GMT). No. of bitstreams: 1 CiceroSMG.pdf: 1142595 bytes, checksum: 20dddd65ffb6900703c4d6782ba12894 (MD5) Previous issue date: 2007-11-28 / Petr?leo Brasileiro SA - PETROBRAS / The use of the natural gas is growing year after year in the whole world and also in Brazil. It is verified that in the last five years the profile of natural gas consumption reached a great advance and investments had been carried through in this area. In the oil industry, the use of the natural gas for fuel in the drive of engines is usual for a long date. It is also used to put into motion equipment, or still, to generate electric power. Such engines are based on the motor cycle of combustion Otto, who requires a natural gas with well definite specification, conferring characteristic anti-detonating necessary to the equipment performance for projects based on this cycle. In this work, process routes and thermodynamic conditions had been selected and evaluated. Based on simulation assays carried out in commercial simulators the content of the methane index of the effluent gas were evaluated at various ranges of pressure, temperature, flowrate, molecular weight and chemical nature and composition of the absorbent. As final result, it was established a route based on process efficiency, optimized consumption of energy and absorbent. Thereby, it serves as base for the compact equipment conception to be used in locu into the industry for the removal of hydrocarbon from the natural gas produced / A utiliza??o do g?s natural vem crescendo ano ap?s ano em todo o mundo e tamb?m no Brasil. Verifica-se que nos ?ltimos cinco anos o perfil de consumo de g?s natural veicular ganhou um grande alcance e v?rios investimentos foram realizados nesta ?rea. Na ind?stria do petr?leo a utiliza??o do g?s natural para combust?vel no acionamento de motores j? vem de longa data, e o mesmo ? utilizado tamb?m para movimentar equipamentos, ou ainda, para gerar energia el?trica. Tais motores baseiam-se no ciclo motor de combust?o Otto, que requer um g?s natural com especifica??o bem definida, conferindo caracter?sticas anti-detonantes necess?rias ao desempenho de equipamentos com projetos baseados neste ciclo. Neste trabalho foram analisadas rotas de processo enfocando caracter?sticas necess?rias ? montagem de um equipamento compacto e simples que permitisse remover com efici?ncia compostos pesados do g?s natural conseguindo-se desta forma um ajuste adequado do ?ndice de Metano, caracter?stica principal na aplica??o do g?s natural em motores a combust?o interna. Foram inicialmente selecionados compostos e condi??es termodin?micas que serviram como base para as rotas estudadas. A partir de simula??es realizadas em aplicativos comerciais foram analisadas os efeitos no ?ndice de metano do g?s efluente decorrentes de varia??es na press?o, temperatura, vaz?o, peso molecular e natureza qu?mica do absorvente. Como produto final foi estabelecida uma rota baseada na efici?ncia de processo, consumo otimizado de energia e absorvente, que se prop?e a servir como base para a concep??o de equipamentos compactos a serem utilizados na ind?stria do petr?leo

Esta Tese está dividida em três volumes: I - Croqui: representação e simulação II - O desenho e o processo de projeto III - O ensino do desenho para arquitetos Os três volumes tratam do mesmo objeto de estudo: o desenho do arquiteto e para a arquitetura, mas sob um enfoque diverso. No Volume I, além de uma abordagem teórica sobre as premissas metodológicas, o desenho é visto sob três outros enfoques: enquanto conceito relativo à problemática inerente à arquitetura, ou seja, representação e simulação do espaço; enquanto instrumento de projeto adaptado a cada momento da arquitetura; e também enquanto objeto artístico. No Volume II, estreita-se a relação entre desenho e projeto de arquitetura, tentando estabelecer relações entre um e outro método. São apresentados os resultados do acompanhamento e análise do trabalho de vários arquitetos, bem como entrevistas, na íntegra, com os arquitetos Paulo Mendes da Rocha, Joaquim Guedes e Abrahão Sanovicz. No Volume III, o ensino do desenho tem destaque com base nas teorias da escola ativa, os métodos de ensino-aprendizagem e sua adaptação ao universo da arquitetura. Nos três volumes, a intenção principal é sempre verificar os pressupostos básicos para o ensino de desenho para futuros arquitetos. Os três volumes são permeados por conclusões inerentes ao enfoque sobre o qual se referem. No final do terceiro volume, apresenta-se uma conclusão sobre o enfoque geral, tratado nos três volumes, relacionando imagem, desenho e projeto para fins didáticos. / This Thesis is divided in three volumes: I - Croquis: representation and simulation II - Design and process of the project III - Teaching of the design to architects The three volumes deal with the same object to study: the design of architect and to architecture, but under a different focus. In the first volume, besides a theoretical aproach about the metodological premisses, the design is seen under three other focuses: as a concept conected to the problematic inherente to the architecture, I mean, representation and simulation of the space; whereas instrument of the project adapted to each moment of the architecture; and even as artistic object. In the volume II, narrows the conection between design and project of architecture, trying to stablish conexions between one and other method. Here are presented the results of the attendance and analyse of the work of various architects, as well as briefinga, as a whole, with the architects Paulo Mendes da Rocha, Joaquim Guedes and Abrahão Sanovicz. In the volume III, the teaching of the design has a prominence based in the theories of the active school, the methods of teaching-apprenticeship and its adaptation to the architecture universe. In the three volumes, the main target is always verify the basic pressuposed to the teaching to the future architects. The three volumes are interposed by conclusions inherents to the focus on which they refer. At the end of the third volume, we present a conclusion about the general focused, treated in the three volumes, linking image, drawing and project to didacts aims.