الفهرس Only 14 pages are availabe for public view
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Abstract
The research includes several studies about thermodynamic performance of a steam turbine which is primarily determined by the steam path components. Because the efficiency of the entire power plant cycle is largely dependent on the efficiency of the energy conversion in the turbine, it is important to minimize aerodynamic and steam leakage losses in the steam path. Nozzle and bucket aerodynamic-profile losses, secondary-flow losses, and leakage losses. In order to ensure high-efficiency turbine designs without sacrificing turbine reliability, it is necessary to use both highly-efficient nozzle and bucket designs to minimize profile and secondary losses, and advanced clearance controls to minimize leakage flows. Solid particle erosion studied as a major important effective factor on steam path surfaces which studied through an experimentation to illustrate particle profile on the blades surfaces and how to protect blades from erosive wear. A numerical investigation result of solid particle erosion in the nozzle of 300 MW steam turbine is presented to show the eroded zone which increases the throat area through the nozzle provoking changes in the operation conditions. On the other hand, it is shown that the solid particles flow cause the most severe erosion rate whereas the steam mass flow rate is the most sensitive parameter, Finally it is obtained that the erosion rate decreases as the diameter of the particle increases in a nearly linear form. The research presents an idea and analysis of application of a new solution of a stage before extraction in the modernized LP part of 200MW turbines. A failure case of the low pressure blades of steam turbine is presented in this research where the suction side of blades has been quenched to improve the erosion resistance. New methods have been developed for the modeling of steam turbines. In particular, the new models give a better description of part-load performance than previously models. Two case histories of steam components degradation identified during operation and verified during overhaul are presented. The diagnosis was carried out before the overhauls to indicate major problems to the personal of the plants. Any power loss occurring locally in intermediate stages of a steam turbine results in more available energy in the downstream stages. This effect is well known as the loss factor (LF) which introduced here in thermodynamic expression to improve applications to evaluate malfunctions in the first and intermediate stages of steam turbines. The research illustrate how to detect deterioration in the thermal performance by audit which trending changes in various performance parameters and identify the cause of performance degradation by proper data evaluation and interpretation. During this research Applying condition monitoring is showing different degradation modes to make steam turbine in service well beyond their intended lifetimes without expensive Dismantling decision for inspection. Then making Performance analysis to show conditions which reduce machine efficiency and work output. Data obtained from tests before and after overhaul also reveal whether any restorative work achieved the expected improvements in performance. This research describes typical turbine problems and the monitoring techniques developed and used for the determination of corrosive conditions, and characteristics of materials, exfoliated oxides causing solid particle erosion, and deposit buildup in steam turbines.
The last part introduce a suggestion of a steam turbine used as a driver to air compressor including a design of the steam path components with studying of the effect of operating conditions on steam consumption and the turbine efficiency of this steam