The design of last stage low pressure steam (LP) turbines has become increasingly complicated as turbine manufacturers have pushed for larger and more efficient turbines. The tip sections of these LP turbines encounter condensing wet steam at high velocities resulting in increased losses. These losses are difficult to predict with computational fluid dynamic models. To study these losses and improve the design of LP turbines a study was commissioned to determine the feasibility and cost of a steam cascade facility for measuring low pressure turbine blade tip section aerodynamic and thermodynamic performance. This study focused on two objectives: 1) design a steam production facility capable of simulating actual LP turbine operating conditions, and 2) design an instrumentation system to measure blade performance in wet steam. The steam production facility was designed to allow the test section size to be selected later. A computer code was developed to model the facility cycle and provide equipment requirements. Equipment to meet these requirements, vendors to provide it, and costs were found for a range of test section sizes. A method to control the test section conditions was also developed. To design the instrumentation system two methods of measuring blade losses through entropy generation were proposed. The first method uses existing total pressure probe techniques. The second method uses advanced particle imaging velocimetry techniques possibly for the first time in wet steam. A new method is then proposed to modify the two techniques to take measurements at non-equilibrium states. Finally accuracy issues are discussed and the challenges associated with achieving periodic flow in this facility are investigated. / Master of Science

Tests were conducted in the Lubrication Laboratory of the Virginia Polytechnic Institute to study the effect of several metals on the deterioration of steam-turbine oils. A special test apparatus was constructed and three commercial turbine oils were tested in the presence of 14 different metal and metal combination. Included in this group of metals were five bearing metals, several metals now extensively used in turbine lubricating systems, and several metals that are not at present used in turbine oiling systems. Oxidation of the oils was accomplished by heating the oil in glass containers at 275°F for 200 hours, in the presence of the metals. The oil samples were then subjected to laboratory inspections to determine the extent of oxidation. It was found that in the case of oil A copper, lead and the copper-lead combination were increasingly effective in increasing the viscosity and acidity. Brass, copper, and copper-lead were increasingly effective in promoting sludge formation. With oil B copper, lead, and the copper-lead combination were increasingly effective in promoting sludge formation and increasing the viscosity. Steel, lead and the copper-lead combination were increasingly effective in producing acidity. Copper, metal No. 9, and the copper-lead combination were increasingly effective in increasing the viscosity of oil C. Copper, metal Ho. 5, and copper-lead produced acidity in increasing amounts. Aluminum, zinc, and cooper were increasingly effective in promoting sludge formation. Tin showed the least effect on solidity in the case of all three oil. It caused the lowest sludge formation with oils A and B and was low with oil C. The viscosity of oil A was least affected by metal No. 6, of oil B by metal No. 8, end of oil C by steel. / Master of Science

Thesis. 1977. M.S.--Massachusetts Institute of Technology. Dept. of Mechanical Engineering. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING. / Includes bibliographical references. / M.S.

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

For industrial processes high availability and efficiency are important goals in plant operation. This thesis presents studies and development of tools for on-line treatment of process deterioration and model and sensor errors in order to achieve these goals. Deterioration of measurement devices, process components and process models has caused economical losses, plant failure and human losses. The development of on-line methods to prevent such losses is of special interest and has been conducted at The Department of Energy Technology, Mälardalen University. Important technological obstacles to implementing automatic on-line methods have been identified, such as data selection for adaptation and adaptation of data-driven models to new states. A new method has been developed for decision support by combining artificial intelligence methods and heat and mass balance models, and concepts are proposed for decision support in order to detect developing faults and to conduct appropriate maintenance actions. The methods have been implemented in simulation environment and evaluated on real process data when available. The results can be sumarised as successful development of a decision support method on a steam turbine by combining artificial neural networks and Bayesian networks, and identification of important obstacles for automation of methods for adaptation of heat and mass balance process models and data-driven models when they are subject to deterioration.

Thesis (M.S.)--Florida State University, 2006. / Advisor: Juan C. Ordonez, Florida State University, College of Engineering, Dept. of Mechanical Engineering. Title and description from dissertation home page (viewed Sept. 15, 2006). Document formatted into pages; contains viii, 78 pages. Includes bibliographical references.

Orientador: Luiz Carlos Pereira da Silva / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de Computação / Made available in DSpace on 2018-08-10T03:25:09Z (GMT). No. of bitstreams: 1 Marques_FredericoAugustoSpolidorio_M.pdf: 3699527 bytes, checksum: fee04cbb6876f5ce62626058ebc660e7 (MD5) Previous issue date: 2007 / Resumo: Este projeto busca relacionar diversos aspectos interdisciplinares envolvidos em uma central de co-geração de energia elétrica. Motivado pela crescente inserção de centrais de geração distribuída operando de forma ilhada ou paralela ao sistema, foram desenvolvidos modelos mecânicos (térmicos e dinâmicos) e elétricos buscando representar os diversos equipamentos envolvidos em uma central de geração em um nível industrial. Baseado nesta concepção, optou-se pela geração de energia através de máquinas térmicas (turbinas a vapor) impulsionadas pela energia proveniente da queima de biomassa restante de diferentes processos industriais. Os modelos teóricos aqui representados foram numericamente simulados com parâmetros obtidos em um estudo de caso real. Seus resultados foram então comparados qualitativamente e quantitativamente contra as variáveis reais do processo analisado. Ao consolidar esta ferramenta de estudo, o simulador mostrou-se eficiente no treinamento de operadores de casas de forças, sendo capaz de esclarecer as interferências entre o nível de carga com as demais variáveis envolvidas em seu processo / Abstract: This project intends to gather several interdisciplinary aspects common to a co-generation power plant. Driven by the increasing amount of distributed generation units operating on island or parallel mode with the network, some mechanical (thermo and dynamic) and electrical models were developed in order to represent the equipments usually installed on an industrial size power station. Based on this concept, the more convenient option was to proceed the evaluation through turbo machinery (steam turbine) driven by the energy acquired from the heat power on burning byproducts of industrial processes. The theoretical models were simulated with parameters obtained from a real case study. The results were then finally compared with real process information acquired from field research. In order to consolidate this computational tool, the simulator has shown efficient results on training power station operators on clarifying the impacts of load level on the other relevant variables on their processes / Mestrado / Energia Eletrica / Mestre em Engenharia Elétrica

M.Ing. / This dissertation deals with the structural integrity analysis of a low pressure (LP) turbine with transverse cracking. Cracks are initiated in the centre ring keyway of the shaft by a fretting mechanism and propagate during barring operation. The cracks arrest during normal operation when they are still relatively shallow. The aim of the calculations is to predict the transition where cracks start propagating by high cycle fatigue during normal operation of the shaft. Most influencing factors, including continuum mechanics, mathematical modelling, material behaviour, service loads and industry experience, are studied in detail as a precursor to the case study. The calculated results show that the case study is an example where the application of fracture mechanics on the crack-free stress field leads to erroneous results. There is a significant redistribution of stress in the presence of the crack so that the actual stress ratio, as calculated from three dimensional cracked models, varies significantly compared to the crack-free model. Calculated results, together with carefully researched material properties, confirm the postulated crack growth during barring operation and predict limiting crack sizes where high cycle fatigue would ensue during normal operation. The case study concludes that the shaft has a significant remaining life and that it can be returned to service with periodic non-destructive examinations.

The amount of incoming solar energy to earth is greater than any other source. Among existing technologies to harness solar energy there is concentrating solar power (CSP). One advantage of CSP is that is dispatchable, meaning that it can provide power even when the sun is not shining. However, CSP is undergoing challenges which hinder its development such as operating variabilities caused by the fluctuations of the sun or the fact that these systems are not yet cost competitive with respect to other technologies.   One way of improving the performance of CSP plants (CSPPs) is by increasing their operational flexibility, specifically their capability for fast starts. In this way it is possible for the CSPP to harness the solar energy as soon as possible, thus producing more energy and increasing its profitability. Over 90% of CSPPs use a steam turbine to generate electricity. Steam turbines are not currently designed with the flexibility required by the CSP application. Steam turbine start-up is limited by thermal stress and differential expansion. If not carefully controlled, these phenomena either consume lifetime or even result in machine failure. The aim of this work was to understand the improvement potential of steam turbine start-up and quantify this in terms of CSPP performance indicators. For this, a thermo-mechanical steam turbine model was developed and validated. The model was then used to analyze potential improvements and thermal constraints to steam turbine start-up operation. Furthermore, a CSP plant techno-economic model was developed including steam turbine details. This modeling approach including two levels of detail allowed for the particularities of the component to be included within the dynamics of the plant and thus be able to connect the perspectives of the equipment manufacturer with those of the plant operator. Reductions of up to 11.4% in the cost of electricity were found in the studies carried out. / <p>QC 20170814</p>

The aim of the thesis is to design a high-speed steam turbine as a small energy source. Steam turbine consists of a high-pressure, a medium-pressure and a low-pressure part with a removable condensing module. High-pressure part is designed to perform a single-stage radial turbine with axial steam outlet. The work also includes the layout of the modules and sections. To design individual parts are used steam table „X-steam“.