Steam turbines control, correction

Figure 17.4 shows a centrifugal pump, driven by a steam turbine. The correct operating speed for the pump and turbine is that speed that puts the process-control valve in a mostly open, but still controllable, position. As we slow the turbine to force open the process-control valve, the turbine s governor valve will close. Steam flow to the turbine will decline in accordance with fan laws ... 

These operating problems must be overcome by selecting the correct system. Figure 15.15 shows an arrangement that balances the process steam and electrical demands by running the turbo-alternator in parallel with the electrical supply utility. The turbine inlet control valve maintains a constant steam pressure on the turbine exhaust, irrespective of the fluctuation in process steam demand. 

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