Turbine control

In most utibty boilers, steam pressure regulation is achieved by the throttling of turbine control values where steam generated by the boiler is admitted into the steam turbine. Some modem steam generators have been designed to operate at pressures above the critical point where the phase change between Hquid and vapor does not occur. 

ASME Gas Turbine Control and Protection Systems B133.4 Published 1978 (Reaffirmed Year 1997)... 

The gas turbine control systems are fully automated, and ensure the save and proper startup of the gas turbine. The gas turbine control system is complex and has a number of safety interlocks to ensure the safe startup of the turbine. 

Lubrication skid. The gas turbine lubrication skid is usually independent of the steam turbine skid as the lubrication oil is usually synthetic due to the high temperatures in the gas turbine. Another reason is due to water contamination of the lubrication oil from the steam turbine. It is advisable to have the lubrication system be totally independent. The gas turbine lubrication skid would report to the gas turbine controller. Since the lubrication system is also used for providing cooling, it is usually operated for about 20 minutes after the gas turbine is shutdown. The lubrication skid contains at least three pumps, two pumps in which each can provide the head required and a third pump, which is usually recommended to be a DC drive for emergency use. These pumps and their control fall under the drive level hierarchy. 

The fuel. skid. This could contain a gas compressor if the fuel gas pressure is low and a knockout drum for any liquid contamination that the gas may have. The requirement of fuel gas pressure is that it should be operated at a minimum of 50-70 psi (3.5-4.83 Bar) above the compressor discharge pressure. The compressor and its motor drive fall under the drive level hierarchy. In the case of liquid fuels, the skid may also contain a fuel treatment plant, which would have centrifuges, electrostatic precipitators, fuel additive pumps, and other equipment. These could be directly controlled by the D-CS system, which would then report its readiness to the gas turbine controller. 

Probably the biggest single advantage of dry gas seals is getting rid of the seat oil. The seal oil system, even when part of a combined lube and seal system, is a complex assembly. With the dry gas seal, the lubrication oil system is all that is needed to service the compressor train bearings and, on turbine driven units, to also supply turbine control oil. As. ui aside, it makes feasible the dream long held by the compressor vendor of having a standardized lube system line. 

Conrad,J. D,.Jr, Know How Your Turbine Controls Work, Power Eng., p. 70, March (1959). 

The Spleen is also important for maintaining balance in the functions of the internal organs. Located in the middle of the body, it is like a turbine, controlling the upward and downward movement of the Qi. It can therefore connect the Lung and Heart, which are located in the upper part of the body, and the Kidney and Liver, which are located in the lower part of the body. (See Figures 13.1 and 13.2 on page 311.)... 

Liese E.A., Smith T.P., Haynes C., Gemmen R.S. (2006) A dynamic bulk SOFC model used in a hybrid turbine controls test facility. In Proceedings of the ASME Turbo Expo, Barcelona, Spain, GT2006-90383. 

Wind Turbine Control Systems Fernando D. Bianchi, Hernan De Battista and Ricardo J. Mantz... 

For additional details on turbine controls and optimization, refer to Section 2.19. 

Back-pressure turbine control system for the generation of LP steam, provided with valve position-based optimizer. 

The ratio (Exf/Exiu>) >1 due to inevitable exergy loss is in the boiler, and hence cHP > cF. Similarly, the cost rate balance for the turbine (control volume 2) is... 

Calculate the flow through the turbine control valve using the methods of Chapters 6 and 10. Enthalpy is unchanged by the throttling process, and so the specific enthalpy at the inlet to the first stage will be equal to the upstream specific enthalpy ... 

Table 2.7. Typical data for simulating gas-turbine control systems...

This defect is met in commercial BWR designs by additional circulation of the coolant around the reactor core, over and above the coolant removed as steam through the turbines. Controllers link the flow rate to the power demand as felt on the turbine, so that the increased coolant input sweeps out the steam bubbles and compensates for the void effect. The RBMK has a similar additional coolant circulation which is necessary, perhaps, for its satisfactory operation with a negative water void coefficient but would exacerbate the disadvantage of a positive coefficient. This again was a feature of the Chernobyl accident. 

McGuire, (McGuire Nuclear Plant) (1988), A safety injection/Reactor trip occurred due to a design deficiency of the main turbine controls Followed by various Equipment Malfunctions, LER (Licensee Event Reports) 369-87-017-01. 

Change of the turbine control system Adaption to modem technology, difficulties with spare parts, high service costs of the system 1994... 

The main turbine and turbine control valves, were analyzed to identify capability to mange the new steam generation rate from the nuclear reactor, control capability of the turbine control valves, considering that the pressure in the reactor vessel was unchanged related to the original design pressure. For such purposes tests were successfully performed to show the capability of the control system. 

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