Steam turbines illustration

The gas turbine performance at part-load follows the same basic form as that for steam turbines illustrated in Figure 23.10, with the mass flowrate defined in terms of the mass flowrate of fuel. Thus, the part-load gas turbine performance can be modeled as4,9 ... 

The second step in developing the process air train is selecting the air blower main driver. This step includes many alternatives such as power recovery expanders, steam turbines, and electric motors. The following example illustrates these alternatives. 

This approaeh was well illustrated by Brieseh et al. f 14], who showed separate plots of ( o)h. ( o)l and (t o)cp against pressure ratio for a given T ax and r ,in (Fig. 7.11), illustrating the validity of Eq. (7.35). But note that the limiting allowable steam turbine entry temperature also influences the ehoiee of pressure ratio in the gas turbine eyele. 

It is important to seal the glands on the turbine shaft, and a typical arrangement is illustrated in Figure 14-24. Thrust bearing failures can be serious problems for steam turbines and other mechanical drives, as well as the bearings used on the driven equipment. 

Figure 43.6 illustrates the periodic motion time-domain curve of a steam turbine bearing pedestal. Displacement is plotted on the vertical, or Y-axis, and time on the horizontal, or X-axis. The curve shown in Figure 43.6 is the sum of all vibration components generated by the rotating element and bearing-support stmcture of the turbine. 

Figure 23.10a illustrates the relationship between turbine efficiency and mass flow through the turbine. Because hMECH his, the major contribution to the nonlinear trend of the overall efficiency with part-load is from the isentropic efficiency his A turbine model needs to capture this behavior. It should also be noted that there will be an efficiency associated with an electricity generating set coupled to the steam turbine (typically 95 to 98%). 

The relationship between shaft power and mass flow through a heat engine is sometimes called the Willans Line. A typical Willans Line for a steam turbine is illustrated in Figure 23.10b. For many machines this is almost a straight line. 

In order to derive the part-load equations, consideration should be given to how the full-load performance depends on the steam pressure drop. Peterson and Mann10 present curves of the overall efficiency of industrial steam turbines at maximum load. The form of such curves is illustrated in Figure 23.11a. Each curve represents data for many steam turbines at fullload. Performance curves of this form can be used to derive the steam turbine model. Another interpretation... 

Air cooled condensing plants, steam turbines with multiple reheating cycle are described and analyzed. Diagrams and plates illustrating design and plants are appended. 4 refs, cited. 

In the case of "flash steam" power plants, the steam is either generated directly by the production wells or the wells produce hot water from which steam can be separated to drive conventional steam turbine generators. The size of these plants ranges from 100 kW to 150 mW. Figure 2.104 illustrates the optimizing control system for such a geothermal facility. 

Figure 7.2c illustrates how a variable-speed drive (a steam turbine) can be used to control throughput. The turbine is driven by high-pressure steam (600 psia) and discharges into a low-pressure steam header (25 psia). A flow controVspeed control cascade structure is used. The output signal from the flow controller adjusts the setpoint of the turbine speed controller, which manipulates the flow of high-pressure... 

More information about the power production is illustrated in the energy balance shown in Table 5.7. Here the CLC configurations are compared with an IGCC without CO2 capture and an IGCC with conventional Selexol pre-combustion CO2 capture. It is demonstrated that in the packed beds, more energy is produced by the gas turbine, because of the lower C02/H20-temperature, but this is for a large extent compensated by the higher electricity production by the steam turbines. 

Kehlhofer, Rolf, et al. Combined-Cycle Gas and Steam Turbine Power Plants. 3d ed. Tulsa, Okla. Penn Well, 2009. Application of gas turbine as part of cutting-edge powergeneration technology. Presents concepts, components, applications, operations of these plants. Each chapter has illustrative figures. Peng, William W. Fundamentals of Turbomachinery. Hoboken, N.J. John Wiley Sons, 2008. Chapter 8 discusses gas turbines and covers thermodynamics, design, efficiency, and performance, as well as applications illustrated. 

Modern piping and instrumentation drawings show the motor symbol connected to the driven equipment. This equipment may be a pump, compressor, mixer, fan, conveyor, or generator. Figure 7-9 illustrates the standardized symbols for compressors, steam turbines, and motors. 

Lubrication systems provide a constant source of clean oil to pump and compressor bearings, gearboxes, steam turbines, and rotating or moving equipment. A typical lubrication system includes a lubricant reservoir, pump, valves, heat exchanger, and piping. Figure 9-5 illustrates how an industrial lubrication system operates. 

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