No description available.

No description available.

M.S.

The VPI plant has met the load situation of the 1935-1936 heating season with a small margin of capacity. Should it have been considered necessary, as a matter of policy, to carry reserve through this heating season, 20,751 pounds per hour of steam capacity would have been lacking. To meet the maximum possible hourly-load anticipated for the 1936- 1937 heating season, it would require an increase in the present capacity of the plant of 11 percent. Considering the carrying of ample reserve, an increase of 117 percent would be necessary. In that the load has reached and passed the most economical output from the standpoint of fuel consumption, forcing of present equipment will now involve economic losses that may be used to offset the costs of a new boiler installation. The load duration curve shown in Fig. 11 will be valuable in economic studies of this type. In conclusion, the authors suggest the possibility of using capacity now latent in the plant. The building of a storage place to make dry coal available tor No.4 boiler would release approximately 6,700 pounds per hour of latent steam capacity. Further gains could be made by forcing boilers 1, 2, and 3 to higher ratings with excess air during the peak hours, while the use of a higher grade bituminous coal during the heavy heating season would also show substantial gains in capacity. / Master of Science

In 1939, a fifth steam generating unit was added to the Virginia Polytechnic Institute Central Heating and Power Plant. This unit was an E. Keeler, 500 horsepower, three drum, bent water tube type boiler, fired by a Westinghouse five retort underfeed stoker with link-grate section. Soon after the installation of this unit, W.F. Diamond and C.F. DeBush made an investigation to determine the effects of various fuel bed depths on the efficiency of the unity. Approximately 6 1/2 years have elapsed since their investigation was completed. No other tests have been conducted on the unit up to now. Consequently, its performance characteristics and maximum thermal efficiency at the present time are not accurately known. Even though Diamond and DeBusk made their investigation to determine the effect of various depths of fuel bed on the performance of the unit, the optimum percentage C0₂, and the range of load for maximum thermal efficiency, there is at the present time, a decided difference of opinion among the power plant personnel regarding these facts. It is contemplated that a sixth unit will shortly be installed in the V.P.I. Power Plant. Therefore, it is necessary to know what maximum continuous load and what peak loads for short periods of time the No. five until can be expected to carry now that it has been in operation for almost seven years. During the past two or three years, the operation of the stoker on the No. five unit has not been satisfactory. Large coke trees (see Discussion of Results, page 67) are formed in the fuel bed at the front end of the stoker where coal enters the furnace. There coke trees ride on the fuel bed as it moves from the front end of the furnace to the ash discharge orifice (see Fig 18), and are only partially consumed during combustion. When they reach the ash discharge orifice clogging results. This necessitates cleaning the orifice and ash discharge plates with a firing iron. Actual cases have been known to occur when a complete loss of load and a 50 per cent reduction in steam pressure have resulted from the clogging of the orifice. / Master of Science

Thesis. 1975. M.S.--Massachusetts Institute of Technology. Dept. of Mechanical Engineering. / Includes bibliographical references. / M.S.

Made available in DSpace on 2016-12-23T14:07:27Z (GMT). No. of bitstreams: 1 Dissertacao de Valter Barbosa de Oliveira Junior.pdf: 5244754 bytes, checksum: 0e5a4d27ed2f4da1d96089d0041ddaaa (MD5) Previous issue date: 2009-08-28 / Centrais termelétricas a vapor são capazes de utilizar biomassa e fazer o reaproveitamento de resíduos agrícolas, resíduos urbanos ou subprodutos industriais para produzir energia elétrica, condicionadas aos seus projetos. Este trabalho tem como objetivos representar, por meio de modelos matemáticos, os principais componentes que constituem o circuito de vapor de uma planta de geração termelétrica a vapor, com foco em caldeira aquatubular, e apresentar uma avaliação dos diversos modelos encontrados na literatura de referência, visando dar suporte ao desenvolvimento de aplicações de simulação dinâmica. Os modelos apresentados abrangem a conversão da energia térmica em energia mecânica e a conversão da energia mecânica em energia elétrica. O conhecimento das características das respostas dinâmicas dos componentes de uma central termelétrica é importante para a análise de estabilidade e para o projeto do sistema de controle. A partir dos modelos dinâmicos do processo é possível a realização de testes de estratégias de controle que, interagindo com os modelos da planta, possibilitem identificar previamente o comportamento dinâmico esperado. Este trabalho também pode ser utilizado como uma referência básica para o desenvolvimento de um simulador com finalidade de treinamento de operadores, cuja aplicação possibilita que seja feita a integração total do operador aos procedimentos operacionais, antes mesmo da partida da planta, ampliando a sua capacidade de aprendizagem / Steam power plants are able to utilize biomass and make the recovering of agricultural residues, urban residues or industrial by-products to produce electric energy, conditioned to its projects. This work aims to represent by means of mathematic modeling the main components that constitute the main steam circuit of a steam power plant, with focus in drum boiler, and to present an analysis of the several models founded at the reference literature, aiming to give support to the development of dynamic simulation applications. The models embrace the conversion of thermal energy in mechanical energy and the conversion of mechanical energy in electric energy. The knowledge of the dynamic response characteristics of power plant components is important for the analysis of stability and control system design. From the dynamic model of process is possible to perform tests of control strategies that, having interaction with the plant models, allow the previous indentifying of its hoped dynamic behavior. This work may be used also as a basic reference to the development of a simulator for operators training purpose, whose application allows the operator to be fully integrated to the operational procedures, before the plant start up, increasing his learning ability

Following an introduction, the author describes Texas A&M University and its utilities system. After that, the author presents how to construct simulation models for chilled water and heating hot water distribution systems. The simulation model was used in a $2.3 million Ross Street chilled water pipe replacement project at Texas A&M University. A second project conducted at the University of Texas at San Antonio was used as an example to demonstrate how to identify and design an optimal distribution system by using a simulation model. The author found that the minor losses of these closed loop thermal distribution systems are significantly higher than potable water distribution systems. In the second part of the report, the author presents the latest development of software called the Plant Optimization Program, which can simulate cogeneration plant operation, estimate its operation cost and provide optimized operation suggestions. The author also developed detailed simulation models for a gas turbine and heat recovery steam generator and identified significant potential savings. Finally, the author also used a steam turbine as an example to present a multi-regression method on constructing simulation models by using basic statistics and optimization algorithms. This report presents a survey of the author??s working experience at the Energy Systems Laboratory (ESL) at Texas A&M University during the period of January 2002 through March 2004. The purpose of the above work was to allow the author to become familiar with the practice of engineering. The result is that the author knows how to complete a project from start to finish and understands how both technical and nontechnical aspects of a project need to be considered in order to ensure a quality deliverable and bring a project to successful completion. This report concludes that the objectives of the internship were successfully accomplished and that the requirements for the degree of Degree of Engineering have been satisfied.

<p>This dissertation shows that the architecture of steam generators, steam turbines and heat exchangers for power plants can be predicted on the basis of the constructal law. According to constructal theory, the flow architecture emerges such that it provides progressively greater access to its currents. Each chapter shows how constructal theory guides the generation of designs in pursuit of higher performance. Chapter two shows the tube diameters, the number of riser tubes, the water circulation rate and the rate of steam production are determined by maximizing the heat transfer rate from hot gases to riser tubes and minimizing the global flow resistance under the fixed volume constraint. Chapter three shows how the optimal spacing between adjacent tubes, the number of tubes for the downcomer and the riser and the location of the flow reversal for the continuous steam generator are determined by the intersection of asymptotes method, and by minimizing the flow resistance under the fixed volume constraints. Chapter four shows that the mass inventory for steam turbines can be distributed between high pressure and low pressure turbines such that the global performance of the power plant is maximal under the total mass constraint. Chapter five presents the more general configuration of a two-stream heat exchanger with forced convection of the hot side and natural circulation on the cold side. Chapter six demonstrates that segmenting a tube with condensation on the outer surface leads to a smaller thermal resistance, and generates design criteria for the performance of multi-tube designs.</p> / Dissertation

Following an introduction, the author describes Texas A&M University and its utilities system. After that, the author presents how to construct simulation models for chilled water and heating hot water distribution systems. The simulation model was used in a $2.3 million Ross Street chilled water pipe replacement project at Texas A&M University. A second project conducted at the University of Texas at San Antonio was used as an example to demonstrate how to identify and design an optimal distribution system by using a simulation model. The author found that the minor losses of these closed loop thermal distribution systems are significantly higher than potable water distribution systems. In the second part of the report, the author presents the latest development of software called the Plant Optimization Program, which can simulate cogeneration plant operation, estimate its operation cost and provide optimized operation suggestions. The author also developed detailed simulation models for a gas turbine and heat recovery steam generator and identified significant potential savings. Finally, the author also used a steam turbine as an example to present a multi-regression method on constructing simulation models by using basic statistics and optimization algorithms. This report presents a survey of the author??s working experience at the Energy Systems Laboratory (ESL) at Texas A&M University during the period of January 2002 through March 2004. The purpose of the above work was to allow the author to become familiar with the practice of engineering. The result is that the author knows how to complete a project from start to finish and understands how both technical and nontechnical aspects of a project need to be considered in order to ensure a quality deliverable and bring a project to successful completion. This report concludes that the objectives of the internship were successfully accomplished and that the requirements for the degree of Degree of Engineering have been satisfied.