Early gas turbines were handicapped by
metal not being able to withstand high speed centrifugal forces
the inability to get enough air into the combustion chamber
metals not standing the high temperatures involved
their high operating speeds
their inadequate power cabability
The temperature to which the air can be raised at the turbine inlet is
an indication of a units power
directly related to the unit's size
a function of the air compressor input
an indication of the units efficiency
improper for proper compressor performance
The output power of a gas turbine is directly related to the
mass of gas passing though the turbine per second
temperate at the turbine inlet
mass of the unit
slippage between the turbine and compressor
turbine exhaust temperature
The low installation cost of a gas turbine is
due to cheap materials in the blades
due to short fuel lines
because no fuel pump is required
because no electrical wiring is required
because less auxillary equipment is needed
Some of the characteristics which make the gas turbine a better choice over other prime movers are 1. Low maintenance 2. Minimal cooling water 3. high thermal efficiency 4. rapid start-up and loading
1,2,3,4
1,2,3
1,2,4
1,3,4
2,3,4
The air side of a gas turbine regenerator is located
before the compressor
after the combustion chamber
between the turbine and the combustion chamber
between the turbine and atmosphere
downstream of the compressor
A gas turbine performs most effectively if
lube oil is of the proper viscosity
cooling water temperature is kept low
ambient air temperature is high
ambient air temperature is low
loaded immediately after starting
A combined steam and gas turbine arrangement can be termed
an ideal system
a cogeneration system
a once through system
ideal relative to system efficiency
a high capacity system
The purpose of a regenerator is
to clean the exhaust gases
to improve the efficiency of the turbine
to increase the temperature in the combustion chamber
to lower the temperature in the combustion chamber
to recirculate the exhaust gases back through the compressor
A _________ is suitable for use in the unmanned and remote locations
steam turbine plant
cogeneration plant
gas turbine system
nuclear plant
thermal generating plant
Gas turbine advantages include:
1. high thermal efficiency 2. lower initial cost 3. quick start-up 4. little cooling water requirements 5. power to mass ratio is high 6. remote operation
2,3,4,5,6
1,2,4,6
1,2,3,4,5,6
Disadvantages of a closed cycle gas turbine include: 1. higher initial cost 2. increased cooling water requirements 3. turbine blade fouling 4. they require more creep resistant material than open cycle turbines
1,2
The output power on a gas turbine increases when its colder outside because:
cooling water requirements are lower
colder air has the ability to hold more moisture
higher compressor volumetric efficiency
mass flow of the incoming air is greater
all of the above
A ________ gas turbine system uses the same working fluid over and over again
open cycle
dual shaft
closed cycle
regenerator
emergency power
The major components of a gas turbine system include
low pressure compressor, turbine and duxt burner
compressor, combustor and regenerator
compressor, combustor and turbine
starting motor, oil coolers and flux capacitor
generator, compressor, turbine and combustor
Two stage compression is used in a gas turbine system to:
increased turbine output
reduce the size of the machine
lower the amount of fuel consumed
reduce maintenance costs
increase the compressor life
A regenerator in a gas turbine cycle is located:
between the combustor and the turbine
between the compressor stages
prior to air compression
between the compressor and the combustor
at the turbine outlet
A gas turbine is most efficient when: 1. clean fuel is used 2. turbine blades are clean 3. gas path is clean 4. lubricating oil is clean 5. ambient air temp is low 6. operated at 1/2 load
1,2,3,4,6
1,2,3,4,5
1,3,5
1,2,3,5
A gas turbine operates on the
otto cycle
daltons law
brayton cycle
Charles law
diesel
Remote gas turbines may be started by: 1. mechanical linkages 2. telephone 3. radio link 4. timer relays
2,3
3,4
1,4
2,4
In a total energy arrangement a gas turbine may exhaust its flue gas to: 1. HRSG 2. waste heat boiler 3. atmosphere 4. SAGD
1,3
A gas turbine may be used as a prime mover to operate:
air compressors
fire pumps
generators
emergency equipment
