Power augmentation

The augmentation of power in a gas turbine is achieved by many different techniques. In this section, we are looking at techniques, which could be achieved on existing gas turbines. Thus, techniques such as additional combustors are not considered as being practical on an existing turbine. In other words, the concentration in this section is on practical solutions. Practical power augmentation can be divided into two main... 

A commercial combustion turbine with the provision to inject, at any point upstream of the combustor, the externally supplied humidified and preheated supplementary compressed air. Engineering and mechanical aspects of the air injection for the compressed air injection plant concepts are similar to the steam injection for the power augmentation, which has accumulated significant operating experience. 

Figure 2-41. Heated and humidified eompressed air injeetion system for power augmentation of a gas turbine.

Cyrus, B., Meher-Homji, T.R., and Mee III, Gas Turbine Power Augmentation by Fogging of Inlet Air, 28th Turbomachinery 28 Symposium Proceedings p. 93 1999. 

The code provides for the testing of gas turbines supplied with gaseous or liquid fuels (or solid fuels converted to liquid or gas prior to entrance to the gas turbine). Test of gas turbines with water or steam injection for emission control and/or power augmentation are included. The tests can be applied to gas turbines in combined-cycle power plants or with other heat recovery systems. 

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. 

Example case history 5. Power augmentation for a gas turbine in cogeneration... 

Little and Rives, Steam Injection of Frame 5 Gas Turbines for Power Augmentation in Cogeneration Service, IGTI, 1988. 

This important book provides operators of industrial gas turbines with a review of the principles of gas turbine operation and how they can be used to predict and improve turbine performance. The book is accorr5)anied by a CD which allows readers to simulate such aspects of performance as emissions, changes in pressure and power augmentation. 

Kinetic data are available for the nitration of a series of p-alkylphenyl trimethylammonium ions over a range of acidities in sulphuric acid. - The following table shows how p-methyl and p-tert-h xty augment the reactivity of the position ortho to them. Comparison with table 9.1 shows how very much more powerfully both the methyl and the tert-butyl group assist substitution into these strongly deactivated cations than they do at the o-positions in toluene and ferf-butylbenzene. Analysis of these results, and comparison with those for chlorination and bromination, shows that even in these highly deactivated cations, as in the nitration of alkylbenzenes ( 9.1.1), the alkyl groups still release electrons in the inductive order. In view of the comparisons just... 

FIG. 17-61 Electrically augmented gramilar-Led filter. (Combustion Power Company.)... 

The thermodynamic analysis presented here is an outline of the air-standard Bray ton cycle and its various modifications. These modifications are evaluated to examine the effects they have on the basic cycle. One of the most important is the augmentation of power in a gas turbine, this is treated in a special section in this chapter. 

Water injection, or steam injection systems, are being used extensively to augment power. Corrosion problems in the compressor diffuser and combustor have not been found to be major problems. The increase in work and efficiency with a reduction in NO makes the process very attractive. Split-shaft cycles are attractive for use in variable-speed mechanical drives. The off-design characteristics of such an engine are high efficiency and high torque at low speeds. 

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... 

Combination of Evaporative Cooling and Steam Injection. The combination of the above techniques must also be investigated as none of these techniques is exclusive of the other techniques and can be easily used in conjunction with each other. Figure 2-44 is a schematic of combining the inlet evaporative cooling with injection of steam in both the compressor exit and the combustor. In this system, the power is augmented benefiting from... 

Wheatstone, C. (1867). On the Augmentation of the Power of a Magnet by the reaciion thereon of Currents induced by the Magnet itself Proceedings of (be Royal Society, Februaiy. 

---