Gas turbines compressors

Injection of Water or Steam at the Gas Turbine Compressor Exit. Steam injection or water injection has been often used to augment the power generated from the turbine as seen in Figure 2-42. Steam can be generated from the exhaust gases of the gas turbine. The HRSG for such a unit is very elementary as the pressures are low. This technique augments power and also increases the turbine efficiency. The amount of steam is limited to about... 

The concept of injecting humidified and heated compressed air just after the gas turbine compressor is another very interesting way to increase power and efficiency. In this system, compressed air is added to the compressed discharge air. The compressed air is about 5% of the main gas turbine air and this air after it has been compressed using an external compressor is then injected into an air saturation device where steam obtained from the HRSG unit is then injected into the device to saturate the air with water and the saturated air then is further heated in the HRSG before it is injected into the compressor discharge of the gas turbine. 

The rule of thumb for a multiple stage gas turbine compressor would be that the energy rise per stage would be constant, rather than the commonly... 

The turbine temperature, flow, and speed increases in a very short time of about three to five minutes to the full rated parameters. There is usually a short period of time where the temperature may overshoot. If supplementary firing or steam injection for power augmentation is part of the plant system, these should be turned on only after the gas turbine has reached full flow. The injection of steam for power augmentation, if done before full load, could cause the gas turbine compressor to surge. 

Figure 20-11. Gas turbine compressor efficiency as a function of temperature ioad.

The work produced by the gasifier turbine (fFgt) is equal to the gas turbine compressor work (fFJ ... 

Dr. Boyce has authored more than 100 technical papers and reports on Gas Turbines, Compressors Pumps, Fluid Mechanics, and TurboMachinery. He is a Fellow of the ASME, and the Institute of Diesel and Gas Turbine Engineers, U.K., and member of SAE, NSPE and several other professional and honorary societies. He is also a registered professional engineer in Texas. 

By far, the largest application of the axial compressor is the aircraft jet engine. The second most common usage is the land-based gas turbine, either the aircraft derivative or generic designed type. In last place of the applications comes the process axial compressor. All principles of operation are exactly the same. About the most obvious difference is that the gas turbine compressor is a higher pressure ratio machine and therefore has more stages. 

Of the gas turbine-compressor combinations previously mentioned, gas turbines are by far the most frequently used as drivers for centrifugal compressors. Next in use would be axial compressors and, on occasion, the gas turbine is used as a driver for the larger screw compressors. There... 

Unit Gas Turbine Compressor Section Turbine Section ... 

Combined Brayton-Rankine Cycle The combined Brayton-Rankine cycle. Figure 9-14, again shows the gas turbine compressor for the air flow to the cell. This flow passes through a heat exchanger in direct contact with the cell it removes the heat produced in cell operation and maintains cell operation at constant temperature. The air and fuel streams then pass into the cathode and anode compartments of the fuel cell. The separate streams leaving the cell enter the combustor and then the gas turbine. The turbine exhaust flows to the heat recovery steam generator and then to the stack. The steam produced drives the steam turbine. It is then condensed and pumped back to the steam generator. 

The performance of a SOFC system with a Brayton-Rankine bottoming cycle for heat and fuel recovery has been calculated. Gas turbine compressor and expander efficiencies of 83% and 89% and a steam turbine efficiency of 90% have been assumed. 

Regarding the need for absolute removal of all free liquid mist, such as with a gas turbine compressor suction scrubber, I find a 100-pm particle size selection to be good design practice. This particle size fallout before reaching a demister pad will indeed ensure that most any demister pad will remove all remaining free liquid mist. 

The gas turbine compressor is the means of heating the SOFC to ion conduction operating temperature, a considerable advantage, amplified in Section 4.1.9. 

Because the IT/SOFC integrates well with the gas turbine so as to burn fuel not consumed by isothermal oxidation, and because the gas turbine compressor provides the means to elevate the system temperature to ion conduction level for start-up purposes, the IT/SOFC is a promising choice, with a wide selection of competing types. 

Also burned in the gas turbine combustion chamber is the excess fuel and oxygen which the isothermal oxidation process of the fuel cell cannot consume. The gas turbine compressor takes in atmospheric air, which is separated into oxygen and nitrogen oxygen for the fuel cell and compressed nitrogen to contribute its exergy to the gas turbine combustion chamber, in which it is heated for expansion in the turbine. 

Figure 8 Potential application of catalytic filters in the IGCC cycle. Legend 1. gasifier 2. catalytic filter unit 3. combustion chamber 4. gas turbine-compressor setup 5. boiler for heat recovery from exhaust gases 6. condenser 7. steam turbine.

The gasifier is of an air-blown type. Thus about 10 % of the air is extracted from the gas turbine compressor, further con ressed in a booster compressor, and finally injected into the bottom of the gasifier. 

The catalytic activity of substituted hexa-aluminates for methane combustion is low compared with noble metals, like Pd. For use in a fully catalytic combustor, these materials will have to be combined with a first stage with higher activity. For other fuels the differences are not so pronounced, e.g. for diesel. Hexa-aluminates also show a high activity in CO and H2 combustion and gasified biomass. For these kinds of fuels the ignition temperatures over hexa-aluminates are in the same area as the outlet temperature from the gas turbine compressor. 

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