الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
 |  | from | 97 |  |  |
| | | from | 97 | | |
Abstract
INTRODUCTION
1.1 GAS TURBINE USAGE ”ref [1]”:
Gas turbines are used in a wide range of services. They power aircraft of all types and drive mechanical equipment such as pumps, compressors, and generators in electric utilities. They also generate power for peak loads and base-load duties. Recently, the interest in gas turbines has grown significantly in combined-cycle plants. These plants use combinations of gas and steam turbines in various configurations of turbines, heat recovery steam generators, and regenerators.
Gas turbines have these advantages over steam plants:
eThey are small in size, mass, and initial cost per unit output.
eTheir delivery time is relatively short and they can be installed quickly.
eThey are quick starting (as low as 10 s), often by remote controL
eThey are smooth running and have a capacity factor (percent of time the unit is operating at full power) of96 to 98 percent.
eThey can use a wide variety of liquid and gaseous fuels including gasified coal and synthetic fuels.
eThey are subject to fewer environmental restrictions than other prime movers.
Figure 1.1 illustrates a simple cycle gas turbine. The compressor raises the pressure of inlet air 15 to 25 times. The work required by the compressor appears in the flow in the form of increased temperature. The discharge temperature of the compressor is about 750 to 870°F (400 to 465°C). The combustors burn the fuel to increase the temperature of the compressed air to between 2500 and 2600°F (1370 to 1427°C). The turbine nozzles (stationary blades) convert the high~enthalpy air to high velocity. The turbine buckets (moving blades) convelt this energy into rotary motion. The turbine discharge temperature is around 900 to 1 180°F (482 to 638°C).
The categories of gas turbines are:
1. Industrial heavy-duty gas turbines
2. Aircraft-derivative gas turbines
3. Medium-range gas turbines
4. Small gas turbines