• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 58
  • 24
  • 17
  • 7
  • 5
  • 4
  • 3
  • 3
  • 3
  • 3
  • 3
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 138
  • 36
  • 25
  • 16
  • 14
  • 14
  • 14
  • 13
  • 12
  • 12
  • 11
  • 11
  • 11
  • 11
  • 10
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Combustion emissions from conventional boiler firing coal and tire derived fuel /

Potluri, Srinivas, January 1991 (has links)
Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1991. / Vita. Abstract. Includes bibliographical references (leaves 66-67). Also available via the Internet.
22

Dispersed-phase flow control in boilers with pressurized vertical spindle mills /

Elshabasy, Aly Abdelaziz, January 2006 (has links)
Thesis (Ph. D.)--Lehigh University, 2006. / Includes vita. Includes bibliographical references (leaves 221-229).
23

Industrial energy analysis and conservation

Dorling, John January 1989 (has links)
This work is concerned with the analysis of industrial energy use for the purposes of reducing that use to a minimum within the constraints imposed by the existing plant. The work is divided into two parts. Firstly, a general analysis of the energy used in an industrial plant is made for the year 1986. Based on monthly records of energy consumption and environmental parameters, it is primarily intended to heighten management awareness of energy flows and the relative contributions from each energy type towards the total annual consumption and cost. It is performed using a suite of interactive linked computer programs and the data is reduced to a graphical form for presentation in a report. The analysis is a first approximation, assuming steady state conditions with many parameters time and space averaged, but is justified by the findings that monetary savings approaching 5% of the annual energy bill could be made with changes to operational procedures alone. As a result of this work, it was revealed that the boiler-house supplying the majority of the plant with high pressure hot water for process and space heating requirements used more than half of the total annual energy requirements and that potential energy savings were likely. Secondly, a detailed analysis of the energy used by the boiler-house is- carried out. A real time monitoring and targeting system which records and displays boiler, environmental and plant parameters is developed and installed. Data gathered over a period of six months enables (i) specific cases of energy wastage resulting from operational procedures to be identified and (ii) trends of performance indicating poor energy efficiency to be traced. The system developed may be used to provide the information necessary to enable improved control. A general result which may be inferred from this work would be that the combined approaches of a topdown general analysis and a bottom-up detailed analysis of energy use can provide significant opportunities for energy conservation resulting solely from the improved operation of large energy consuming plant. The work was performed at a major manufacturing plant in the U. K. with an annual energy consumption of the order of 600 gigawatt-hours and an annual energy bill of the order of E10 million.
24

Projeto e simulação de um sistema de controle via LMIs da produção de vapor de uma caldeira aquatubular

Franco Junior, Ary [UNESP] 30 November 2012 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:22:31Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-11-30Bitstream added on 2014-06-13T18:08:25Z : No. of bitstreams: 1 francojunior_a_me_ilha.pdf: 1767942 bytes, checksum: 2d9c6747eea634729a7e8682fb849965 (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / A caldeira de uma usina de açúcar e etanol é um dos equipamentos mais importantes neste tipo de indústria, pois é responsável pela geração de vapor para o processo indus- trial e geração de energia. De todas as malhas de controle presentes em uma caldeira, a que desperta maior atenção é a do controle da produção de vapor, pois este controle está envolvido com a alimentação de água e calor do sistema, com a produção de vapor, que é o objetivo da caldeira, e com a pressão do vapor, um parâmetro crítico para o funcionamento da caldeira e até para a turbina responsável pela geração de energia elé- trica em uma planta industrial. O sistema de controle utilizado atualmente é ineficiente, visto que os parâmetros do mesmo são ajustados na maioria das indústrias, utilizando o método da tentativa e erro. Além disso, esse ajuste é feito apenas para um ponto de operação da caldeira, sendo que dada uma mudança no ponto de operação devido a vários fatores que possam acontecer, o sistema deve ser ajustado novamente. Neste trabalho, é descrito o funcionamento de uma caldeira e o seu sistema de automação e controle atual- mente utilizado para a malha de controle da produção de vapor, e consequentemente seus problemas. O sistema de produção de vapor de uma caldeira aquatubular é modelado matematicamente, o modelo não linear obtido é então linearizado. São simulados os dois modelos (linear e não linear) para alguns distúrbios da planta; define-se o desempenho esperado do sistema de controle; é projetado um controlador para este sistema através do uso de Desigualdades Matriciais Lineares, em inglês Linear Matrix Inequalities (LMIs), método este que garante restrições nos sinais do sistema controlado. Finalmente... / A sugarmill drum-boiler is one of the most important equipament in this industry type, because it is responsible for the steam generation for the industrial process and generation of energy. Considering the control systems presented in a drum-boiler, the one that wakes up larger attention is the steam production control, because this control is involved with the water feeding and heat feeding of the system, the steam production, that is the objective of the drum-boiler, and with the pressure of the steam, a critical parameter for the drum-boiler operation and also for the turbine that is responsible for the electric power generation of the industrial plant. This control system used nowadays is inefficient, because it is adjusted, in most of the industries, using trial and error method. Besides, that adjustment is just made for a drum-boiler operation point, and given a change in the operation point due to several factors that can happen, the system should be adjusted again. In this work it is described the drum-boiler operation, its automation system and control nowadays used for the steam production control, and consequently its problems. The drum-boiler steam production system is mathematically modeled, by a nonlinear system and then, this model is linearized. Both models (linear and nonlinear) are simulated for some plant disturbances, the expected control system performance is defined, a controller is designed for this system through the use of Linear Matrix Inequalities (LMIs), which method guarantees constraints on the controlled system signals. Finally, the linear and nonlinear controlled models are simulated for some plant... (Complete abstract click electronic access below)
25

Projeto e simulação de um sistema de controle via LMIs da produção de vapor de uma caldeira aquatubular /

Franco Junior, Ary. January 2012 (has links)
Orientador: Marcelo Carvalho Minhoto Teixeira / Banca: José Paulo Fernandes Garcia / Banca: Alfredo Del Sole Lordelo / Resumo: A caldeira de uma usina de açúcar e etanol é um dos equipamentos mais importantes neste tipo de indústria, pois é responsável pela geração de vapor para o processo indus- trial e geração de energia. De todas as malhas de controle presentes em uma caldeira, a que desperta maior atenção é a do controle da produção de vapor, pois este controle está envolvido com a alimentação de água e calor do sistema, com a produção de vapor, que é o objetivo da caldeira, e com a pressão do vapor, um parâmetro crítico para o funcionamento da caldeira e até para a turbina responsável pela geração de energia elé- trica em uma planta industrial. O sistema de controle utilizado atualmente é ineficiente, visto que os parâmetros do mesmo são ajustados na maioria das indústrias, utilizando o método da tentativa e erro. Além disso, esse ajuste é feito apenas para um ponto de operação da caldeira, sendo que dada uma mudança no ponto de operação devido a vários fatores que possam acontecer, o sistema deve ser ajustado novamente. Neste trabalho, é descrito o funcionamento de uma caldeira e o seu sistema de automação e controle atual- mente utilizado para a malha de controle da produção de vapor, e consequentemente seus problemas. O sistema de produção de vapor de uma caldeira aquatubular é modelado matematicamente, o modelo não linear obtido é então linearizado. São simulados os dois modelos (linear e não linear) para alguns distúrbios da planta; define-se o desempenho esperado do sistema de controle; é projetado um controlador para este sistema através do uso de Desigualdades Matriciais Lineares, em inglês Linear Matrix Inequalities (LMIs), método este que garante restrições nos sinais do sistema controlado. Finalmente... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: A sugarmill drum-boiler is one of the most important equipament in this industry type, because it is responsible for the steam generation for the industrial process and generation of energy. Considering the control systems presented in a drum-boiler, the one that wakes up larger attention is the steam production control, because this control is involved with the water feeding and heat feeding of the system, the steam production, that is the objective of the drum-boiler, and with the pressure of the steam, a critical parameter for the drum-boiler operation and also for the turbine that is responsible for the electric power generation of the industrial plant. This control system used nowadays is inefficient, because it is adjusted, in most of the industries, using trial and error method. Besides, that adjustment is just made for a drum-boiler operation point, and given a change in the operation point due to several factors that can happen, the system should be adjusted again. In this work it is described the drum-boiler operation, its automation system and control nowadays used for the steam production control, and consequently its problems. The drum-boiler steam production system is mathematically modeled, by a nonlinear system and then, this model is linearized. Both models (linear and nonlinear) are simulated for some plant disturbances, the expected control system performance is defined, a controller is designed for this system through the use of Linear Matrix Inequalities (LMIs), which method guarantees constraints on the controlled system signals. Finally, the linear and nonlinear controlled models are simulated for some plant... (Complete abstract click electronic access below) / Mestre
26

Economic scheduling of steam boiler plant shut downs for targeted availability

Els, Daniel Pieter 30 November 2011 (has links)
M.Ing. / In the highly competitive environment in which all companies have to operate, it is becoming more and more important to optimise the amount of time a piece of equipment is down for scheduled repairs and the scheduling of these repairs. In this dissertation the equipment that is considered are the seventeen Babcock Borsig designed boilers situated on the Sasol Secunda site. A schematic drawing of these boilers is shown in figure 1. This drawing does not include the Electrostatic Precipitator that is located at the outlet of the boiler. The main function of the seventeen boilers on the Secunda site is to supply process steam to the rest of the factory. With each of the plants that are supplied with process steam having its own needs at any point in time, ensuring that enough steam is available in the system becomes an extremely important issue. The reason for this is that the plants that are supplied with process steam form a train and if one of the plants can not produce to full capacity, the down stream plants are also affected. The secondary function of the boilers is to supply steam to ten turbines for the generation of electricity. This means that any steam that the factory is not using is used for the generation of electricity. The ten generators can not supply the full need of the factory and the rest is drawn in from the national electricity supplier. It is thus best to generate as much electricity as possible. With the price of electricity varying during the year, winter being more expensive, the time when a boiler is off becomes critical. To ensure that the necessary process steam is available the long term plan of the factory is used to calculate the year budget for steam required by the factory. But as with everything plans do change and a short term plan is used to ensure that enough process steam is available for the factory.
27

Strategic issues for life extension of boiler feed pump drives at coal fired power stations

Govender, T. 04 October 2010 (has links)
M.Ing. / South Africa is presently experiencing a power shortage problem. This has led to numerous investigations into generating needed capacity and finding ways of saving power where possible, in order to sustain an acceptable extra capacity of at least ten percent. This dissertation investigates the possibility of saving power consumed by the electrical boiler feed pumps through engineering management strategies. The technical system drive unit is considered as a case study and consists of the following electrical and mechanical components: • Boiler feed pump. • Boiler feed pump transformer. • Variable speed drive. The methods identified to improve the Variable Speed Drive (VSD) system reliability and obtain total efficiency are: • Technical evaluation of the system. • Engineering management tools including reliability and availability. • A strategic focus on reliability improvement. Technical evaluation of the system includes evaluating the condition of the existing system and possibly replacing it with the latest technology should the system prove inefficient. Engineering management tools such as Total Quality Management (TQM) and Total Productive Maintenance (TPM) ensure that the plant is in a high state of readiness at all times. Strategic management issues in the broader context that influence reliability and availability management have been identified to improve productivity contributing to total organizational overall efficiency. One of the main research conclusions of the dissertation is that not only inherent reliability of a technical system is important but also the achievable reliability in the broader strategic organizational context. The research strategy was exploratory and included an integrated case study on electrical boiler feed pump drives.
28

Susceptibility of service exposed creep resistant materials to reheat cracking during repair welding

Loots, Riaan 04 May 2005 (has links)
Please read the abstract in the section front of this document / Dissertation (MEng(Metallurgical Engineering))--University of Pretoria, 2006. / Materials Science and Metallurgical Engineering / unrestricted
29

Comprehensive black liquor droplet combustion studies /

Ip, Leong-Teng, January 2005 (has links) (PDF)
Thesis (Ph. D.)--Brigham Young University. Dept. of Chemical Engineering, 2005. / Includes bibliographical references (p. 137-145).
30

Boiler maintenance using expert systems

Gamede, Cyril Vuyani January 1989 (has links)
This research explores the application of expert systems to the maintenance of boilers, are as follows: and its main objectives [1] To explore the application of expert systems in the maintenance of boilers. [2] To simplify the task of boiler maintenance with the help of expert systems. [3] To improve the skills of boiler maintenance workers through the knowledge 'captured ' or 'preserved' by expert systems. [4] To minimise errors which may cost time, money, effort and possible risk of injury to boiler maintenance personnel. [5] To develop a prototype expert system which can advise and assist boiler maintenance personnel. [6) To contribute to research in the application of expert systems in the field of engineering.

Page generated in 0.0396 seconds