In the combustors of a gas turbine, how much air usually bypasses the combustion chambers:
90%
80%
60%
50%
20%
The disadvantages of using a regenerator in a gas turbine cycle are: 1. Heating surfaces become coated and must be cleaned 2. Increased capital costs 3. It produces a pressure drop through the system 4. The temperature drop through the system will be reduced
2,3
1,2,4
1,3,4
2,3,4
1,2,3,4
Maximum power achieved by a gas turbine as a function of
The number of turbine stops and starts every year
The number of times base load power output is exceeded
The number of times peak load is obtained in a year
The number of times operational limits are exceeded
Life expectancy of hot gas components
The regenerator of a gas turbine cycle is a:
second combustor
heat exchanger
Vessel used to transfer heat from the exhaust gas to the working fluid before compression occurs
Increase the pressure of the working fluid in the system
Increase the temperature of the combustor's outlet
The gas turbine system is ideal:
For large generator systems
To be used over a steam turbine
To be used for unmanned and remote locations
For all applications of a process plant
For large gas plant
The advantages of a dual shaft gas turbine arrangement are: 1. Greater flexibility 2. It is cheaper 3. Smaller starting motors may be used 4. High pressures and temperatures may be obtained
1,2
1,3
2,4
1,4
Control of a gas turbine is accomplished by:
Varying the loading station
The power turbine all speed governor
Varying load on the generator
Varying the fuel flow
Controlling the shaft speed
The turbine exit gas temperatures will be a maximum of:
600 deg C
700 deg C
750 deg C
800 deg C
850 deg C
Reducing gears are used with gas turbines to:
Control the speed of the power turbine
Drive slower lube oil pumps
Reduce turbine speed before shutdown
Achieve desired speed of the load
Reduce horsepower requirements
A closed cycle gas turbine system
Does not use a starting motor
Has lower pressure used in system
Will use the same working fluid over again
Must use a cooler before the regeneration
Has a lower initial cost than that of the open cycle gas turbine
