Turbines turbine design considerations

Radial-Inflow Turbines 329 Turbine Design Considerations... 

Griffin, D.A. and AshwUl, T.D. (2003), Alternative composite materials for mega-watt-scale wind turbine blades Design considerations and recommended testing , Journal of Solar Energy Engineering, Vol. 125, p. 515. 

GLOSSARY TYPES OF TURBINES TURBINE DESIGN CHARACTERISTICS Turbine Stage Design and Construction Thermodynamic Considerations Performance of Mechanical-Drive Steam Turbines Control Systems... 

The Hawthorne and Davis approach thus aids considerably our understanding of a/s plant performance. The main point brought out by their graphical construction is that the maximum efficiency for the simple [CHT]i cycle occurs at high pressure ratio (above that for maximum specific work) whereas the maximum efficiency for the recuperative cycle [CHTX]i occurs at low pressure ratio (below that for maximum specific work). This is a fundamental point in gas turbine design. 

The first design considerations for the HHV plant began with a system, where a fossil-fired heater replaced the nuclear heat source. However, because of the desired peak temperatures of 850 C (1000 °C for shorter periods) and the design pressure of 50 bar there were feasibility concerns about the lifetime capability of such a fossil-fired heater. Thus a test circuit was chosen comparable to a closed-cycle gas turbine plant as shown in Fig. 5. 

From a spatial perspective, the characteristic of both wind and solar is that they are diffuse resources. This results in projects spread over areas as least as large as fossil-fuel power plants. For wind, the other important characteristic is that it is site specific, so that a wind resource must be developed exactly on the site where sufficient wind is available it cannot be moved to a more convenient location. This implies built-in potential for direct conflicts with whatever may exist already in the same place. A third salient consideration is that no matter how the wind turbines are designed, painted, erected, or spaced to make them less obtmsive or annoying, they cannot be made invisible. Consequently, controversy over their deployment should have been anticipated. One of the best-known examples of such controversy is found near Palm Springs, California (Pasqualetti, 2001, 2002). Two others, less familiar, include the proposal for the Isle of Lewis, in the U.K. and another planned for La Venta, in the state of Oaxaca, Mexico. 

Fired Hester a.s a. Reactor. When viewed as a reactor, the fired heater adds a unique set of energy considerations, such as. Can the heater be designed to operate with less air by O2 and CO analy2ers How does air preheating affect fuel use and efficiency How can a lower cost fuel (coal) be used Can the high energy potential of the fuel be used upstream in a gas turbine ... 

Cracking reactions are endothermic, 1.6—2.8 MJ/kg (700—1200 BTU/lb) of hydrocarbon converted, with heat supplied by firing fuel gas and/or fuel oil in side-wall or floor burners. Side-wall burners usually give uniform heat distribution, but the capacity of each burner is limited (0.1—1 MW) and hence 40 to 200 burners are required in a single furnace. With modem floor burners, also called hearth burners, uniform heat flux distribution can be obtained for coils as high as 10 m, and these are extensively used in newer designs. The capacity of these burners vary considerably (1—10 MW), and hence only a few burners are required. The selection of burners depends on the type of fuel (gas and/or liquid), source of combustion air (ambient, preheated, or gas turbine exhaust), and required NO levels. 

Thrust-Bearing Power Loss The power consumed by various thrust bearing types is an important consideration in any system. Power losses must be accurately predicted so that turbine efficiency can be computed and the oil supply system properly designed. 

One of the main reasons for the good performance of the diesel, compared with alternative machines, is due to the fact that the design is not restricted by metallurgical considerations which, for instance, limits the higher gas temperature in the gas turbine. This is because the cylinder wall is only subject to intermittent peak temperature due to combustion and its average temperature is much lower than the mean gas temperature. Therefore, the cyclic temperature can be maximized. 

Where an under-slung condenser has been specified, the provision of a basement to the engine room offers the attraction of compactness at the expense of enhanced civil works, while alternatively, the specification of pannier condensers can obviate the need for a basement and will simplify the foundation design, but will considerably increase the floor area requirements. The condensing plant itself consists essentially of banks of tubes through which cooling water flows and around which exhausted steam from the turbine is condensed to form a vacuum. Such tubes have traditionally been made of brass, but where severe corrosion conditions exist, cupro-nickel is sometimes used. 

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