3B2 Flashcards
- In an impulse steam turbine nozzle, the following events take place:
1) the steam pressure decreases
2) the enthalpy of the steam decreases
3) the velocity of the steam increases
4) the volume of the steam increases
A) 1,2,3
B) 1,3,4
C) 1,2,3,4
D) 1,2,3
C) 1,2,3,4
- Turbine nozzles convert heat energy into:
A) potential energy B) enthalpy C) eddy-currents D) kinetic energy E) pressure
D) kinetic energy
- The purpose of the bucket or moving blade on the rotor is to convert the _____ energy of the steam into ____ energy.
A) heat, potential B) kinetic, useful C) kinetic, mechanical D) heat, kinetic E) mechanical, kinetic
C) kinetic, mechanical
- In an impulse turbine as the steam passes through the moving blades the _____ drops but the _____ remains the same.
A) velocity, pressure B) enthalpy, velocity C) pressure, velocity D) volume, velocity E) volume, kinetic energy
A) velocity, pressure
- The pressure at the outlet from the moving blades is the same as the pressure at the inlet to the moving blades in the____turbine.
A) topping B) reaction C) back-pressure D) impulse E) extraction
D) impulse
- Steam turbine stationary nozzles serve to:
1) decrease steam pressure
2) increase steam enthalpy
3) decrease steam friction
4) increase steam velocity
A) 1,2,3 B) 1,3,4 C) 1,4 D) 2,3 E) 2,3,4
C) 1,4
- On an extraction turbine the extraction pressure is:
A) not critical B) varied according to turbine load C) maintained constant regardless of turbine load D) proportional to the turbine load E) reduced if load increases
C) maintained constant regardless of turbine load
- A back-pressure turbine which exhaust steam to an old Boiler header still supplying steam to an old lower pressure turbine is called:
A) condensing-bleeder turbine B) cross compound turbine C) condensing turbine D) topping turbine E) mixed pressureturbine
D) topping turbine
- A topping turbine is a special application of a _____ turbine.
A) condensing B) extraction C) condensing-bleeder D) tandem compound E) back-pressure
E) back-pressure
- ______ turbines are large turbines consisting of two or more turbines in series coupled together as one shaft and applied to one generator.
A) topping B) tandem-compound C) condensing-bleeder D) cross-compound E) mixed pressure
B) tandem-compound
- A generator coupled on one shaft to a turbine consisting of two or more turbines in series is called?
A) condensing-bleeder B) cross-compound turbine C) mixed pressure D) tandem-compound turbine E) topping
D) tandem-compound turbine
- ______ turbines are large turbines with parallel shafts with a generator on each shaft.
A) condensing B) tandem-compound C) extraction-bleeder D) condensing-bleeder E) cross-compound
E) cross-compound
- In a reaction turbine the steam pressure drops across both the fixed and moving blades while the steam’s ______ velocity rises in the fixed blades and drops in the moving blades.
A) secondary B) primary C) stationary D) moving E) absolute
E) absolute
- The distinguishing feature of a reaction turbine is the fact that the pressure drop across the ______ blades.
A) cutting B) moving C) sectional D) stationary E) angular
B) moving
- In a steam turbine having pressure drop across the moving blades, an unbalanced ____ thrust will be developed upon the rotor.
A) axial B) centrifugal C) radial D) impulse E) rotational
A) axial
- Reaction turbine blades (moving):
1) convert the kinetic energy of the steam into mechanical energy
2) convert heat energy into kinetic energy
3) are nozzle shaped
4) increase the absolute velocity
A) 1,2,3 B) 2,3,4 C) 1,3,5 D) 1,2,4 E) 1,4
A) 1,2,3
- A reaction turbine results in a long machine due to a large number of alternate rows of:
A) nozzles and moving blades B) nozzles and stationary blades C) fixed and moving blades D) stationary blades E) moving blades and nozzles
C) fixed and moving blades
- A turbine that expands the steam in two or more sets of nozzles in series, each set having velocity-compounded blades to receive the steam issuing from the nozzles is called:
A) extraction turbine B) velocity compounded turbine C) pressure compounded turbine D) pressure-velocity compounded turbine E) mixed-pressure turbine
D) pressure-velocity compounded turbine
- In pressure compound steam turbine:
1) the expansion of steam from Boiler pressure to exhaust pressure is carried out in a number of steps or stages
2) each stage has a set of nozzles and a row of blades
3) all of the velocity available is developed in one set of nozzles
4) the rows of moving blades are separated from each other by partitions or diaphragms into which the nozzles are set
A) 1,2,3 B) 2,3,4 C) 1,3,4 D) 1,2,4 E) 1,2,3,4
D) 1,2,4
- In a steam turbine using velocity compounding ________ expands the steam from initial to exhaust pressure.
A) two sets of nozzles and moving blades B) stationary blades C) stationary and moving blades D) moving blades E) one of the nozzles
E) one of the nozzles
- In a condensing-bleeder turbine up to 20% of the total steam flow may be bled off. What is the bleed-steam used for?
A) building heating B) relieving pressure C) atomization of the fuel D) to be reheated in Boiler E) feed-water heating
E) feed-water heating
- A condensing-bleeder turbine can bleed up to ____ of the total steam flow.
A) 0.1 B) 0.15 C) 0.2 D) 0.25 E) 0.3
C) 0.2
- The primary purpose of a back-pressure turbine is electrical generation.
A) true
B) false
B) false
- In a back-pressure turbine the process steam pressure is:
A) kept constant and the generator output depends on the demand for process steam
B) varied and the generator output remains constant
C) kept constant and the generator output remains constant
D) not important
E) dependant on the generator output
A) kept constant and the generator output depends on the demand for process steam
- Extraction turbines are turbines where steam is extracted at one or more points at constant _____
A) flow B) pressure C) load D) temperature E) efficiency
B) pressure
- Labyrinth seals are:
1) made of cast iron
2) a positive leak proof seal arrangement
3) design to have large clearances between the shaft and casing
4) made of brass or stainless steel
5) use on larger diameter turbine shaft
A) 1,2,5 B) 2,4,5 C) 3,4,5 D) 4,5 E) 1,2,3
D) 4,5
- A steam turbine water seal is used ____ to insure that no air leaks in along the shaft.
A) on start up B) at speed below 2000 rpm C) on shut down D) only on condensing turbine E) at speed above 2000 rpm
E) at speed above 2000 rpm
- On larger turbines, the _____ is split in a horizontal direction.
A) shaft B) governor C) cylinder D) rotor E) drum
C) cylinder
- It is general practice to let the thickness of the walls and flanges ____ from inlet to exhaust end of a steam turbine casing.
A) decrease B) fluctuate C) be the same D) vary E) increase
A) decrease
- Materials at the given maximum temperature and under constant pressure continue to deform with very slowly increasing strain of the material; this phenomenon is called ____.
A) creep B) elongation C) deformation D) jerking E) movement
A) creep
- Steam turbine casing joints are made steam tight by matching _____ exactly.
A) thin high temperature gasket B) bowel pins C) alignment notches D) flange faces E) rubber gasket
D) flange faces
- A steam turbine assembled casing is machined off inside a boring mill to:
1) make grooves for shaft seals
2) make grooves for diaphragms
3) machine surfaces for bearings
4) machine flange surfaces flat
A) 1,2,3 B) 2,3,4 C) 1,3 D) 1,2,4 E) 1,4
A) 1,2,3
- A hollow drum rotor, for good balance, is machined both outside and inside thus the drum must be open at one end. How is the drum end cover with shaft installed in the rotor?
A) press fitted B) welded on C) bolted D) press fit and belted E) shrink fit and welded
E) shrink fit and welded
- When disc rotors are assembled, the discs are heated until they are easily slid along the shaft and then located in the correct position on the shaft and shaft key. A small clearance between the discs prevents _____.
A) noises B) slippage C) thermal stress in the shaft D) acceleration E). Vibrations
C) thermal stress in the shaft
- Rotors for high outputs and high temperatures are generally made of ____ steels.
A) chromium B) chromium-nickel C) nickel-molybdenum D) chromium-nickel-molybdenum E) copper-nickel-bronze
D) chromium-nickel-molybdenum
- The axial thrust in impulse turbines is nearly eliminated by use of a balance or dummy piston.
A) true
B) false
B) false
- A balance piston on a steam turbine is used to:
A) counteract vibration and therefore ensure a smooth running unit
B) increase turbine output
C) measure axial position
D) counteract end thrust
E) provide an area to install a labyrinth seal
D) counteract end thrust
- A steam turbine balance piston is fitted with rings to ensure a tight seal.
A) true
B) false
B) false
- A steam turbine balance piston is fitted with _____ to ensure a tight seal.
A) carbon rings seal B) blades seal C) water seal D) diaphragm E) labyrinth seal
E) labyrinth seal
- Reaction steam turbines often uses _____ seals as part of the shroud with the seal clearances kept as small as possible.
A) radial B) water C) radial and axial D) carbon E) axial
C) radial and axial
- The purpose of a thrust bearing on large reaction steam turbines is to:
1) give confidence to the operator
2) to keep the rotor in an exact position in the casing
3) prevent any steam from escaping
4) to absorb any axial thrust on the rotor
5) support the dummy piston
A) 1,2,3 B) 2,4,5 C) 2,4 D) 3,5 E) 1,4
C) 2,4
- If left at a standstill, while the turbine is still hot, the lower half of the rotor will cool off faster than the upper half and the rotor will _____ or “hog”
A) turn on its own B) bend upwards C) twist D) bend downwards E) stall
B) bend upwards
- A barring gear consists of an electric motor and several sets of reducing gears to turn the turbine shaft at a low speed. It is used:
1) after stopping a hot turbine to prevent “hogging”
2) only on small turbines
3) continually when the turbine is not operating
4) prior to start up for approximately 3 hours
A) 1,2,4 B) 1,2,3 C) 1,4 D) 2,3 E) 2,4
C) 1,4
- A jacking oil pump is used to:
1) make slight adjustments to the turbine bearing housings during overhaul to maintain alignment
2) supply oil to a hydraulic motor for the turning gear
3) supply oil to the bearings under the shaft at all times so lubrication is assured
4) supply a high volume of oil at high pressure
A) 1,2,3 B) 2,3,4 C) 1,3,4 D) 1,2,3,4 E) none of the above
E) none of the above
In a nuclear power station a ____ supplies heat through a ____ to the working fluid in place of a steam plant Boiler.
1) reactor
2) heat exchanger
3) burner
4) pump
A) 1,2 B) 1,3 C) 3,2 D) 1,4 E) 2,4
A) 1,2
- In a nuclear power plant circulating coolant picks up heat in the reactor and rejects it to the _____ in the steam cycle by means of a heat exchanger.
A) hotwell B) condenser C) working fluid D) turbine E) feed pump
C) working fluid
- With _____ a series of nozzle valves opens in sequence as the load increases. This type of governing is most efficient and is used for impulse turbines.
A) throttle governing B) nozzle governing C) speed governing D) bypass governing E) overload governing
B) nozzle governing
- Throttle governing uses a single large control valve so when the steam is throttled the ____, thus increasing turbine efficiency.
A) superheat will increase B) superheat will decrease C) pressure will increase D) pressure will stay the same E) temperature will decrease
A) superheat will increase
- Overload governing is used on ____ turbines.
A) small B) impulse C) low pressure D) reaction E) impulse and reaction
E) impulse and reaction
- ______ is the percent change in speed required for load change equal to the rated.
A) speed governor B) governor speed drop C) governor speed increase D) throttle governing E) integral band
B) governor speed drop
- The two types of governors used on steam turbines are:
1) flow sensitive governor
2) pressure sensitive governor
3) temperature sensitive governor
4) speed sensitive governor
A) 2,4 B) 1,3 C) 1,2 D) 3,4 E) 2,3
A) 2,4
- Back pressure and extraction turbines use ______ in connection with ______.
1) pressure sensitive governor
2) throttle governing
3) speed sensitive governor
4) bypass governing
A) 1,2
B) 1,3
C) 3,4
D) 4,1
B) 1,3
- The overspeed trip on a turbine is usually set to trip the mechanism when it reaches ____ of operating speed.
A) 1 B) 1.05 C) 1.1 D) 1.15 E) 1.2
C) 1.1
- In an/a ______, the spring loaded bolt has a centre of gravity slightly off the centre of the shaft.
A) electric turning gear B) nozzle C) barring gear D) shear pin coupling E) overspeed trip
E) overspeed trip
- In an overspeed trip the spring loaded tripping bolt has a centre of gravity:
A) concentric with the shaft B) towards the nut end of the bolt C) towards the condenser end of the shaft D) towards the head end of the bolt E) towards the centre of the bolt
D) towards the head end of the bolt
- When a hydraulic overspeed trip operates:
1) high pressure oil forces the main steam valve shut
2) high pressure oil supply is shut off
3) the stop valve oil cylinder drain is closed
4) the stop valve oil cylinder drain is opened
5) a spring closes the main steam valve
6) the pilot drain is closed
A) 1,3,6 B) 2,4,5 C) 3,4,6 D) 2,4,6 E) 3,4,5
B) 2,4,5
- When starting up a turbine it is not necessary to open trap bypasses as the traps will remove condensate as it is produced.
A) true
B) false
B) false
- Sealing steam to the turbine glands is admitted ______ is put in operation.
A) before the extraction pump B) before the condenser circulating water pump C) after the air ejector D) after the extraction pump E) after the throttle valve is open
D) after the extraction pump
- The extraction (condensate) pump is put into operation _______ the ________.
1) before
2) after
3) air ejector
4) jack oil pump
5) condenser circulating water pump
A) 1,3 B) 2,3 C) 1,4 D) 1,5 E) 2,5
A) 1,3
- The jacking oil pump supplies oil at pressures of _______ to _____ kPa.
A) 6000-8000 B) 7000-9000 C) 8000-10000 D) 9000-11000 E) 10000-12000
C) 8000-10000
- The jacking oil pump supplies lubricating oil to the:
A) side of the bearing B) top of the bearing C) centre of the shaft D) bottom of the bearings E) thrust bearing
D) bottom of the bearings
- Heat transfer takes place from a _____.
A) hotter to a cooler body except in refrigeration
B) hotter to cooler body if the pressure on hot body is higher
C) cooler to a hotter body
D) cooler to a hotter body
E) hotter to a cooler body
E) hotter to a cooler body
- The rate of heat transfer will depend on:
1) temperature difference
2) thermal resistance to heat flow at the material separating the two fluids
3) area of transmitting surface
A) 1 B) 1,2 C) 1,2,3 D) 2,3 E) 3,1
C) 1,2,3
- In a steam turbine condenser the temperature difference from exhaust steam to cooling water will:
A) remain the same under all loads B) increase with a load decrease C) increase with a load increase for most loads D) remain the same under most loads E) decrease with a load increase
C) increase with a load increase for most loads
- Power plant thermal efficiencies could be easily doubled by removing the ______ and using exhaust steam for heating.
A) hot well B) condenser C) feed pump D) circulating pump E) deaerator
B) condenser
- If the cooling water for a condenser, taken from a cooling tower is high in dissolved oxygen, the ability of the condenser to act as a deaerator is ______.
A) directly proportional to the level of dissolved oxygen
B) not impeded
C) inversely proportional to the level of dissolved oxygen
D) impeded
E) reduced
B) not impeded
- The ____ cooling water is in direct contact with the turbine exhaust steam.
A) down flow condenser B) central flow condenser C) radial flow condenser D) jet condenser E) air ejector
D) jet condenser
- A _____ also acts as a deaerator even with the turbine at full load and the condenser at a reduced vacuum.
A) feed pump B) cooling tower C) air cooled condenser D) surface condenser E) jet condenser
D) surface condenser
- In a ______ the feed pump draws from the hot well only the quantity of feed water required by the Boiler, the remainder overflows into the cooling pond where it is cooled and reused as cooling water.
A) surface condenser B) counterflow condenser C) counterflow condenser D) radial flow condenser E) jet condenser
D) radial flow condenser
- The purpose of a surface condenser is to:
1) maintain a vacuum at the turbine exhaust
2) conserve pure Boiler feedwater
3) act as a deaerator
4) cool the condensate below saturation temperature
A) 1,2,3 B) 2,3,4 C) 1,2,4 D) 1,3,4 E) 1,2,3,4
A) 1,2,3
- A surface condenser may be ____.
1) oval
2) triangular
3) cylindrical
4) rectangular
5) hexagon
A) 1,2,3 B) 2,3,4 C) 3,4,5 D) 1,2,5 E) 1,3,4
E) 1,3,4
- Condenser tube plates can be installed with _____.
1) ferrules
2) metallic or fibre packing
3) roll expanding
4) combination of roll expanding and ferrule
5) all of the above
A) 1,2,3 B) 2,3,4 C) 1,2,4 D) 1,2,5 E) 1,3,4
E) 1,3,4
- In a surface condenser, when the tube plates are practically the same material such as admiralty brass tubes in admiralty brass plates, the tubes can be _____ into the tube plates.
A) ferruled B) welded C) roll expanded D) packed with metallic or fibre packing E) roll expanded at inlet and ferruled at outlet
B) welded
- Allowances must be made for differential expansion of the tubes and shell. Packed tube ends may allow the tube to move ___.
A) through an expansion joint B) through an expansion loop C) very little D) axially in the packing E) radially in the packing
D) axially in the packing
- The classic material for water boxes has always been:
A) admiralty brass B) cast iron C) muntz metal D) low carbon steel E) steel alloy
B) cast iron
- Air in a surface condenser:
1) increases the pressure
2) retards heat transfer
3) enters with the high pressure ejector steam
4) is cooled before being removed
A) 1,2,3 B) 2,3,4 C) 1,3,4 D) 1,2,4 E) 2,3
D) 1,2,4
- In a two stage air ejector for a surface condenser the pressure of the first stage ejector cooler is ____ atmospheric but above ____ pressure.
1) above
2) ejector
3) condenser
4) below
5) steam
A) 1,2 B) 1,3 C) 4,2 D) 4,3 E) 1,5
B) 1,3
- The cooling water for the air ejectors on a surface condenser is _____.
A) row water B) treated water C) condensate D) river water E) distilled water
C) condensate
- The methods to detect cooling water leaks in a surface condenser while it is operation are:
1) pH test
2) electrical conductivity test
3) plastic wrapping test
4) silver nitrate test
5) fluorescent dye test
A) 2,4 B) 1,2,5 C) 2,3,4 D) 1,3 E) 3,4
A) 2,4
- Under normal operating conditions a surface condenser, the atmospheric relief valve is held closed by ______.
A) a spring B) vacuum C) atmospheric pressure D) water pressure E) pressure difference between the atmosphere outside the vacuum in the shell
D) water pressure
- The _____ function is to continually extract the condensate from the condenser Howell and pump it through the air ejector coolers.
A) extraction pump B) circulating pump C) vacuum pump D) feedwater pump E) cooling water pump
A) extraction pump
- The condenser extraction pump suction operates at pressures _____.
A) slightly above atmospheric B) just st below atmospheric C) near absolute zero D) equal to 2 atmosphere E) determined by the level of condensate in the condenser
C) near absolute zero
- In order to prevent air from entering the condenser when the condenser condensate extraction pump is in standby position, the pump is equipped with:
A) shaft sleeves B) labyrinth seals C) mechanical seals D) carbon rings E) water sealed glands
E) water sealed glands
- Feedwater heaters use _____ of bleed steam to heat feedwater.
A) sensible heat B) latent heat C) super heat D) sensible and latent heat E) sensible and super heat
B) latent heat
283 low pressure feedwater heaters are exposed on the waterside to the discharge pressure of the ____ pump.
A) circulating B) extraction C) cooling water D) Boiler feedwater E) air ejector
B) extraction
- High pressure feedwater heaters are exposed on the waterside to the discharge pressure of the _____ pump.
A) extraction B) cooling water C) Boiler feedwater D) circulating E) air ejector
C) Boiler feedwater
- Low pressure feedwater heaters commonly use a _____ design.
A) straight tube B) U tube C) C tube D) bent tube E) low tube
A) straight tube
- High pressure feedwater heaters commonly use a _____ design for thermal expansion and contraction.
A) C tube B) straight tube C) low tube D) U tube E) bent tube
D) U tube
287 the gas turbine system is:
A) ideal for large generator systems
B) ideal to be used over a steam turbine
C) ideal to be used for unmanned and remote locations
D) ideal for applications of a process plant
E) ideal for large gas plant
C) ideal to be used for unmanned and remote locations
- Gas turbines are used in industry as prime movers for:
1) portable generators
2) fire pumps
3) air compressors
4) emergency equipment
A) 1,2,3 B) 1,2,4 C) 1,3,4 D) 1,2,3,4 E) 2,3,4
D) 1,2,3,4
- Gas turbine units are used:
1) for electrical generation
2) where energy is produced for process plants
3) where waste gases from the process may be used to drive the gas turbine
4) where high thermal efficiency is required
A) 1,2,3 B) 1,3,4 C) 2,3,4 D) 1,2,3,4 E) 1,2,4
A) 1,2,3
- Gas turbines are used in large power plants to provide almost instant emergency power for:
A) peak load shaving B) high heating load C) water pumps D) exit lighting E) essential services
E) essential services
- Some of the characteristics which make the gas turbine a better choice over other prime movers are:
1) low maintenance
2) minimum cooling water required
3) high thermal efficiency
4) rapid start up and loading
A) 1,2,3 B) 1,2,4 C) 1,3,4 D) 2,3,4 E) 1,2,3,4
B) 1,2,4
- Gas turbines are far superior to other types of engines in their:
A) fuel consumption B) efficiency C) lubricating oil consumption D) power per mass ratio E) fuel usage
D) power per mass ratio
- A closed cycle gas turbine system:
A) does not use a starting motor
B) has lower pressure used in system
C) will use the same working fluid over again
D) must use a cooler before the regeneration
E) has a lower initial cost than that of the open cycle gas turbine
C) will use the same working fluid over again
- The compressor on a gas turbine:
A) can be driven by the load turbine B) is always of the axial type C) is always a multi stage compressor D) can be of the reciprocating type E) is always of the centrifuge type
A) can be driven by the load turbine
- In a dual shaft gas turbine arrangement:
A) the load turbine is downstream from the compressor turbine
B) the load turbine drives the prop on a turbo prop engine
C) is always used in an open cycle
D) system flexibility is reduced
E) a larger starting motor is required
A) the load turbine is downstream from the compressor turbine
- The advantages of a dual shaft gas turbine arrangement are:
1) greater flexibility
2) it is cheaper
3) smaller starting motor may be used
4) high pressures and temperatures may be obtained
A) 1,2 B) 1,3 C) 2,3 D) 2,4 E) 1,4
B) 1,3
- In a gas turbine cycle using an intercooler the following advantages are obtained:
1) the specific volume of the air is reduced
2) the cooler air recovers more heat from the regenerator
3) the temperature of the second stage compressor will be increased thus increasing thermal efficiency
4) more of the turbine power can be available for the output load
A) 1,2,3 B) 1,2,4 C) 1,3,4 D) 2,3,4 E) 1,2,3,4
B) 1,2,4
- The advantages of using a reheated in a gas turbine cycle are:
1) more air can be compressed
2) a small combustor may be used
3) less air will have to be compressed in order to do the same amount of work
4) the thermal efficiency of the cycle will be improved
A) 1,3 B) 1,4 C) 2,3 D) 2,3 E) 3,4
E) 3,4
- The purpose of a regenerator in a gas turbine is:
A) to clean the exhaust gases
B) to improve the efficiency of the turbine
C) to decrease the temperature in the combustion chamber
D) to raise the air temperature before compression
E) to decrease the air temperature after compression
B) to improve the efficiency of the turbine
- The regenerator in a gas turbine cycle is located:
A) between the power and the load turbine
B) between the turbine outlet and the compressor inlet
C) between the compressor and combustor
D) between the combustor and the turbine
E) between the power turbine and generator
C) between the compressor and combustor
- The regenerator of a gas turbine cycle is a:
A) second combustor
B) heat exchanger
C) vessel used to transfer heat from the exhaust gas to the working fluid before compression occurs
D) increase the pressure of the working fluid in the system
E) increase the temperature of the combustor’s outlet
B) heat exchanger
- A gas turbine air compressor with an intercooler:
A) has the intercooler located after the compressor
B) increases the volume of air being supplied
C) allows more output at the turbine
D) used only with axial type compressors
E) are not as efficient
C) allows more output at the turbine
- The combustion chamber of a gas turbine:
A) increases the pressure of the compressed air
B) burns fuel with excess air
C) is located between the load turbine and the compressor turbine
D) is always of the multiple burner type
E) utilizes 70% of the air supplied by the compressor for actual combustion process
B) burns fuel with excess air
- A gas turbine combustion chamber requires:
A) a cooling water jacket on the inner canister
B) a vacuum breaker
C) a safety pressure relief device
D) a high voltage ignition plug for initial ignition
E) an annual hydrostatic test
D) a high voltage ignition plug for initial ignition
- The capacity of a gas turbine will increase in cold weather because:
A) high grades of fuel oil burn better at cooler temperatures
B) the density of the air is increased
C) the volume of the air will increase
D) the temperature drop throughout the cycle will be less
E) the atmospheric pressure will increase
B) the density of the air is increased
- Which of the following are advantages of a gas turbine:
1) simple design
2) low cost
3) minimal manpower
4) maximum outage time
5) rapid starting
A) 1,2,3,4 B) 2,3,4,5 C) 1,3,4,5 D) 1,2,3,5 E) 1,2,4,5
D) 1,2,3,5
- Which of the following are disadvantages of a gas turbine?
1) complicated design
2) high manufacturing costs
3) slow response to load change
4) low efficiency
5) suitable for low power applications
A) 1,3,5 B) 2,3,4 C) 3,4,5 D) 1,4,5 E) 1,2,3
E) 1,2,3
- The term peaking gas turbine refers to:
A) gas turbines that produce max power
B) gas turbines used with peak horsepower
C) gas turbines used during major outages
D) gas turbines used everyday
E) gas turbines used in heavy load situations
E) gas turbines used in heavy load situations
- Industrial gas turbines compared to aero derivative turbines are:
A) light weight B) rapid load changers C) less efficient D) use all different fuels E) fast starting
C) less efficient
- In simple gas turbines the air is compressed to the following maximum pressures:
A) 2000 kPa B) 2500 kPa C) 3000 kPa D) 3500 kPa E) 4000 kPa
C) 3000 kPa
- Gas turbine final combustion temperatures in a simple gas turbine are:
A) 1500 C B) 1700 C C) 1800 C D) 2000 C E) 2200 C
D) 2000 C
- Gas temperatures at the simple gas turbine inlet section are at maximum:
A) 580 C B) 770 C C) 875 C D) 920 C E) 1050 C
D) 920 C
- Gas temperatures at the exhaust of a simple gas turbine are at maximum:
A) 500 C B) 540 C C) 760 C D) 680 C E) 640 C
E) 640 C
- Aero derivative engines are aircraft jet engines that:
A) are converted from a turboprop engine
B) are heavier in construction than a jet engine
C) are closer in design to industrial gas turbines
D) are more rapid in their startup than jet engines
E) use less power turbine blades
A) are converted from a turboprop engine
- In dual shaft gas turbines the load is driven by:
A) the high pressure turbine
B) the starting motor and low pressure turbine
C) the low pressure turbine
D) the exhaust gases from the combustion chamber
E) the output shaft from the compressor
C) the low pressure turbine
- The term open cycle means:
A) the compressor inlet is open to atmosphere
B) the compressor outlet is open to the combustion chambers
C) the turbine exhaust is open to atmosphere
D) the working fluid is drawn from and returned to the atmosphere
E) every cycle the inlet and outlet are open
D) the working fluid is drawn from and returned to the atmosphere
- What part of the gas turbine is normally smaller in dual shaft gas turbines?
A) the load B) the combustion chambers C) the starting motor D) the compressor E) the turbine blades
C) the starting motor
- Closed cycle means:
A) compressor outlet is closed and the inlet is open
B) combustion chamber is heated internally
C) combustion chamber is heated externally
D) the regenerator is not open on either side
E) the exhaust gases are not open to atmosphere
E) the exhaust gases are not open to atmosphere
- An advantage of closed cycle is:
A) cooling water lowers cost B) fuel is cheaper C) working fluid supports combustion D) pressures are lower so stress is lower onall the equipment E) complexity is less
A) cooling water lowers costs
- Exhaust systems are required on gas turbines to:
1) allow the installation of silencers
2) allow the installation of heat recovery equipment
3) direct the flow to heat recovery systems
4) minimize power losses
5) protect operators
A) 1,3,5 B) 1,2,3 C) 3,4,5 D) 1,4,5 E) 1,3,4
B) 1,2,3
- Gas turbines enclosures are used to:
1) protect equipment from the elements
2) allows the incorporation of heat and gas detectors
3) contains the gas turbine DCS controls
4) keep the turbine from cooling down, more efficient
5) provides ventilation systems
A) 1,2,3 B) 1,2,5 C) 2,3,4 D) 2,3,5 E) 3,5,1
B) 1,2,5
- Auxiliary systems on gas turbines are needed to:
1) provide fuel at the proper temperature and pressures
2) clean and treat fuels
3) provide hydraulic fluid for bearing lubrication
4) inject steam to clean the ducts and housing
5) provide anti icing
A) 1,2,3 B) 2,3,4 C) 3,4,5 D) 1,2,5 E) 2,4,5
D) 1,2,5
- Regarding gears on gas turbines are used:
A) to control speeds B) to drive slower lube oil pumps C) to drive slower hydraulic pumps D) to match turbine and generator speeds E) to increase horsepower
D) to match turbine and generator speeds
- Advantages of gas turbines intakes are:
1) remove contaminants
2) prevent damage from foreign objects
3) allow addition of special cooling systems
4) smooth air flow into the compressor
5) decrease the velocity of the incoming air
A) 1,2,3,4 B) 2,3,4,5 C) 3,4,5,1 D) 4,5,1,2 E) 5,1,2,3
A) 1,2,3,4
- Gas turbines are rated by:
A) output shaft power output vs. fuel energy rate
B) power produced at the output shaft
C) horsepower
D) ratio of rated power to the fuel energy rate
E) ratio of rated power to the LHV of the fuel
B) power produced at the output shaft
- Improving gas turbine efficiency is done by:
1) regeneration
2) precooling
3) aftercooling
4) intercooling
5) reheating
A) 1,2,3 B) 2,3,4 C) 3,4,5 D) 4,5,1 E) 1,2,5
D) 4,5,1
- Regenerators are installed:
A) between the Lp and the Hp compressor sections
B) between the Lp and Hp turbine sections
C) between the outlet and the Lp turbine sections
D) between the Hp compressor and the combustor sections
E) between the combustors and the Hp turbine sections
C) between the outlet and the Lp turbine sections
The beneficial effect of intercoolers decreases with:
A) combining with regeneration B) pressure ratio increase C) colder cooling water D) smaller sized turbines E) higher air throughput
B) pressure ratio increase
Reheat is accomplished by:
A) expanding and heating the gases in two stages
B) heating the gases after the Lp compressor section
C) heating the gases between the Hp and Lp turbine
D) heating the air between the Lp and Hp compressor stages
E) heating the air between the Hp compressor and the Hp turbine sections
C) heating the gases between the Hp and Lp turbine
- How much of the energy provided by the fuel, is absorbed by the compressor:
A) up to 2/3 B) up to 1/3 C) up to 1/2 D) up th 3/4 E) up to 1/4
A) up to 2/3
331: the purpose of a compressor diffuser is to:
A) convert the compressed air exiting the casing
B) convert the compressed air exiting the impeller
C) convert the high pressure air into velocity for the casing
D) convert the high velocity air to pressure energy
E) convert high velocity air to high pressure
D) convert the high velocity air to pressure energy
- The advantages of centrifugal over axial compressors are:
1) high capacity
2) short length
3) high flow rates
4) strength
5) adjustable flow
A) 1,2 B) 2,3 C) 3,4 D) 4,5 E) 2,4
E) 2,4
- In axial flow compressors, compression occurs by:
A) adjusting the stationary blades
B) adjusting the rotating blades
C) adjusting both stationary and rotating blades
D) the use of nozzle blocks between stages
E) adjusting only the moving blades
C) adjusting both the stationary and rotating blades
- In the combustors, how much air is utilized for fuel combustion?
A) 0.1 B) 0.2 C) 0.3 D) 0.4 E) 0.5
B) 0.2
- In the combustors, how much air bypasses the combustion chamber:
A) 0.9 B) 0.8 C) 0.7 D) 0.6 E) 0.5
B) 0.8
- The air bypassing the combustors is used for:
A) increasing the mass of gas products flowing
B) ensuring enough air for complete combustion
C) raising the product temperatures flowing into the turbine blades
D) raising the combustion efficiency
E) cooling the turbine blades
E) cooling the turbine blades
- The combustion chamber exit gas temperatures will reach a maximum of:
A) 1550 C B) 1570 C C) 1650 C D) 1670 C E) 1750 C
D) 1670 C
- The turbine exit gas temperatures will be a maximum of:
A) 600 C B) 700 C C) 750 C D) 800 C E) 850 C
B) 700 C
- Large volume combustors are used when:
A) simplicity is required B) frontal area is no concern C) a regenerator is being used D) less complicated design is called for E) air flow path is less convoluted
C) a regenerator is being used
- The advantage of the Can-Annular design is:
A) uniform outlet temperatures
B) multiple igniters ensure combustion
C) fuel lines distribute fuel more rapidly
D) is a more efficient use of space
E) if one can quits the others will keep working
A) uniform outlet temperatures
- In a single can combustor the interconnected tubes:
A) decreases the number of igniters used
B) decreases the number injectors required
C) decreases the complexity of the turbine
D) decreases the pressures differences in each tube
E) decreases the number of flame tubes required
D) decreases the pressures differences in each tube
- Power is extracted in a gas turbine by:
A) expanding the gases through the turbine blades
B) attaching a generator to the turbine
C) changing pressure to velocity to drive the turbine blades
D) changing velocity to pressure to drive the turbine blades
E) decreasing the hot gas temperature and pressure
E) decreasing the hot gas temperature and pressure
- There are fewer turbine blades than compressor blades because:
A) energy can be extracted more efficiency
B) turbine blades are bigger so require fewer
C) higher exhaust temperatures can be tolerated
D) the hot gases occupy more volume
E) hot exhaust gases are required for the HRSG’s
A) energy can be extracted more efficiently
- Gas turbine blades are cooled to:
A) increase the power output to the HRSG
B) increase metal temperatures out of the turbine
C) increase the longevity of the blades
D) increase flow rates through each section
E) cool the temperature going into the next section
C. Increase the longevity of the blades
- The greatest limitation on increased turbine output is:
A) turbine blade configurations B) heat resisting steels C) design limitations of the turbine shafts D) casing designs that allow flexing E) cost of expensive fuels
B) heat resisting steels
- The maximum run time before blade replacement is:
A) 75,000 hours B) 100,000 hours C) 150,000 hours D) 125,000 hours E) 50,000 hours
B) 100,000 hours
- Control of a gas turbine is accomplished by:
A) varying the loading station B) the power turbine all speed governor C) varying load on the generator D) varying the fuel flow E) controlling the shaft speed
D) varying the fuel flow
- Automatic emergency trips shut off the main fuel valve in the event of:
A) high exhaust temperatures
B) differential pressures are too high across the filters
C) inlet air temperatures exceed maximum
D) compressor discharge pressures are too high
E) compressor discharge temperatures are too high
A) high exhaust temperatures
- Vibration accelerometers are used:
A) if journal or tilt pad bearings are used
B) to trip the turbine on rapid acceleration
C) to control the ramp speed on startup
D) on large industrial gas turbines
E) for anti-friction bearings
E) for anti-friction bearings
- Protective devices will shut down the turbine if:
A) lube oil pressure is too high B) governor oil pressure is too low C) compressor air flow is too high D) combustor gas temperature is too low E) exhaust gas temperature is too high
E) exhaust gas temperature is too high
- Operators are allowed to control _____.
A) the air ratios to the combustors B) the turbine speeds C) the burner logic for combustors D) the turbine ramp rates for startup E) the shutdown sequencing
B) the turbine speeds
- The performance of a gas turbine is calculated by ______.
A) the turbine efficiency B) heat rate vs. power output C) gas flow in vs. kWh out D) gas flow in vs. power output E) gas flow and pressure in vs. power output
B. Heat rate vs. power output
- The number one factor limiting turbine efficiency increases is _____.
A) the blade metallurgy B) the low compressor discharge pressures C) the blade design configuration D) the compression ratio E) the reduction of pressure losses
D) the compression ratio
- Turbine inlet air temperature ____.
A) increases the work done by the turbine
B) decreases the amount of fuel used for the same output
C) decreases the mass of gas flow in the turbine
D) improves overall combustion in the combustors
E) increases the power output of he compressor section
C) decreases the mass of gas flow in the turbine
- Maximum power achieved by a gas turbine is a function of _____.
A) the number of turbine stops and starts every year
B) the number of times base load power is exceeded
C) the number of times peak load is obtained in a year
D) the number of times operational limits are exceeded
E) life expectancy of hot gas components
E) life expectancy of hot gas components
- The operating output of a gas turbine is effected the most by:
A) changing inlet air temperature
B) changing the heat valve of the fuel
C) changing the gas pressure to the combustors
D) changing the combustion flame pattern
E) changing from base loading to peak loading
A) changing inlet air temperature
- Lube oil systems provide two basic functions
A) filtration and anti friction
B) lubricating sliding surfaces in the bearings and cool the bearings
C) an adequate supply of oil to machinery and cooling machine parts
D) filtration and lubricate sliding surfaces
E) vibration dampening and cooling the bearings
B) lubricating sliding surfaces in the bearings and cool the bearings
- All major oil systems consist of what basic components?
1) an oil reservoir to ensure an adequate supply of oil
2) filters to ensure the oil is clean
3) pumps to provide pressure
4) coolers to ensure oil temperatures are kept within operating limits
5) protective, monitoring and control devices
A) 1,2,3,4 B) 1,2,5 C) 1,2,3,4,5 D) 1,5 E) 5
C) 1,2,3,4,5
- Gas turbines use what two different types of bearings?
1) antifriction (roller and/or ball) bearings
2) radial (journal or tilt pad) bearings
3) axial (spherical) bearings
4) take up (frame) bearings
5) swing (levered) bearings
A) 1,4 B) 1,2 C) 1,3 D) 2,4 E) 4,5
B) 1,2
- Why is natural gas the best fuel for a gas turbine?
A) it promotes the most efficient combustion and produces the lowest environmental emissions
B) it is less expensive than other fuel sources
C) it has the highest efficiency of combustion
D) it has less contaminants as compared to other fuel sources
E) it is a lower explosion risk than other fuels
A) it promotes the most efficient combustion and produces the lowest environmental emissions
- Routine maintenance on a gas turbine should involve checking for fuel leaks on a _____ basis.
A) yearly B) monthly C) week.y D) daily E) hourly
D) daily
- An essential auxiliary in a gas turbine installation is:
A) a generator B) a reheated C) a starting motor D) an air heater E) a water pump
C) a starting motor
- Introducing warm air into the gas turbine intake as a result of an anti icing system will?
A) reduce the capacity of the unit, because warm air is less dense than cold air
B) form ice in the air intake
C) cause major damage resulting in catastrophic destruction of the compressor section blading
D) bleed air from the compressor
E) increase hot turbine exhaust
A) reduce the capacity of the unit, because warm air is less dense than cold air
- What is the final step in the sequence of starting a gas turbine?
A) preparation for startup B) loading C) warmup D) crank and light off E) start initiation
B) loading
- What is the first step in the normal shut down of a gas turbine?
A) reduce the speed to idle so the gas turbine can cool down
B) open the breaker that connects the generator to the power system
C) close the fuel valve
D) stop the rotor
E) stop the lube oil system
A) reduce the speed to idle so the gas turbine can cool down
- In order to keep the gas pass of a gas turbine clean the following must be done:
1) inspect and clean the air intake filters
2) water washing of compressor blades
3) inspect and clean air intake ducts
4) good quality fuel must be used
A) 1,2 B) 1,3 C) 1,2,3 D) 1,2,3,4 E) 1,3,4
D) 1,2,3,4
- Why do microturbines require only air bearings?
1) no governing oil system
2) small overall size
3) simplicity of components
4) everything on one shaft
5) no oil systems
A) 1,2 B) 2,3 C) 2,5 D) 3,4 E) 4,5
C) 2,5
- Most aero derivative turbines lube oil systems require?
A) two back lube oil pumps B) separate inlet and outlet filter systems C) separate lube oil tanks and coolers D) separate lube oil systems E) separate back up pumps
D) separate lube oil systems
- Thrust bearings on dual shaft gas turbines are positioned:
A) at the front of the compressor and next to the turbine bearing
B) at the front of both the compressor and the turbine section
C) at the back of the compressor and next to the turbine bearing
D) at the back of the compressor and next to the turbine bearing
E) at the front and back of the turbine section
A) at the front of the compressor and next to the turbine bearing
- Tilt pad bearings are used:
1) in aero derivative gas turbines
2) according to the manufacturer’s specifications
3) on dual shaft industrial gas turbines
4) in large industrial gas turbines
5) with pivot pins
A) 1,2 B) 2,3 C) 3,4 D) 4,5 E) 5,1
D) 4,5
- Aero derivative lube oil systems use a scavenge pump to:
A) recycle oil from the cleaning system
B) collects oil from all users for recycling
C) siphons off small amounts of oil for cleaning
D) collects oil from the supply and return filters for cleaning
E) returns the oil from the bearings to the supply
E) returns the oil from the bearings to the supply
- Natural gas is the best fuel for gas turbines because:
1) no onsite storage
2) most efficient combustion
3) simplest control system
4) highest heat value
5) cleanest burning
A) 1,3 B) 2,4 C) 3,5 D) 2,5 E) 2,3
D) 2,5
- A fuel gas compressor must be used on gas turbines if?
A) the complexity of gas system reduces the gas pressure too low
B) the gas supply pressure is less than the compressor last stage pressure
C) the total pressure drop across the combustors is too great
D) multiple gas nozzles drops the burner gas pressure too low
E) the combustor outlet pressure is greater than compressor outlet pressure
B) the gas supply pressure is less than the compressor last stage pressure
- The most important component of a fuel metering system is?
A) fuel gas Hi/Lo pressure switches B) duplex filters/separators C) fuel metering valve D) primary and secondary shut off valves E) fuel gas scrubber
C) fuel metering valve
- The use of a low heating value (LHV) fuel requires:
A) special nozzles and combustors B) higher pressure gas supply C) higher pressure gas compressors D) higher pressures from the compressor E) larger bore piping for high flow rates
A) special nozzles and combustors
- Typical fuel gas metering valves are:
A) pneumatically adjusted B) a type of pneumatic gas metering control valve C) hydraulically actuated D) electro-pneumatically actuated E) becoming electrically actuated
E) becoming electrically actuated
- Gas turbines use dual fuels for:
1) consists t power delivery
2) use as backup
3) increasing overall power output
4) switching to cheaper fuels
5) less complicated controls during operation
A) 1,2 B) 2,3 C) 2,4 D) 3,4 E) 4,5
C) 2,4
- Fuel system daily maintenance checks consist of:
1) checking the treatment components
2) checking for fuel leaks
3) checking fuel pressures and temperatures
4) checking Delta P across the filters
5) checking the protective devices
A) 1,2 B) 2,3 C) 3,4 D) 2,4 E) 3,5
B) 2,3
- The most important requirements in a dual fuel system is:
A) two types of fuels B) ability to burn both fuels together C) a complex control system D) proper design of the combustors E) special fuel nozzles
E) special fuel nozzles
- Fuel treatment systems consist of:
A) centrifuges, filters, strainers, pumps and related instrumentation
B) filters, dewatering and chemical treatment
C) centrifuges, filters, dewatering and chemical treatment
D) dewatering and chemical treatment
E) mechanical and chemical treatment
C) centrifuges, filters, dewatering and chemical treatment
- Chemicals harmful to the turbine section are:
A) calcium, magnesium and phosphate B) calcium, potassium and silica C) potassium, calcium and magnesium D) sodium, vanadium and silica E) sodium, potassium and vanadium
E) sodium, potassium and vanadium
- Two ways to decrease NOx are:
1) lower the combustion temperature
2) use staged air in the combustors
3) utilize special burners
4) decrease the fuel to air ratio
5) operate with a lean fuel mixture
A) 1,2 B) 2,3 C) 2,4 D) 4,5 E) 3,5
D) 4,5
- The main disadvantage to water or steam injection is:
A) reduced thermal efficiency B) corrosion of the rotating blades C) corrosion of the stationary blades D) corrosion of hot section components E) require ultra pure water or steam
A) reduced thermal efficiency
- Dry low NOx combustion systems operate on:
A) staged fuel burning
B) lean premixed combustion
C) bypass air cooling the flame temperature
D) alternating the spray patterns of the scrubbers
E) injection of dry scrubbing compounds
B) lean premixed combustion
- Control of the dry low NOx burners is done by:
A) adjustable flow nozzles
B) rotating fuel nozzles
C) using three gas headers to inject the fuel
D) extensive solenoid gas staging system
E) computer controlled fuel staging valves
D) extensive solenoid gas staging system
- The practical limit for NOx with steam or water injection for natural gas is:
A) 5 ppm B) 10 ppm C) 15 ppm D) 20 ppm E) 25 ppm
E) 25 ppm
- The practical lower limit for NOx for liquid fuels is:
A) 22 ppm B) 32 ppm C) 42 ppm D) 52 ppm E) 62 ppm
C) 42 ppm
- Starter systems are disengaged when the turbine shaft reaches:
A) once the shafts starts speeding up B) once the turbine speed overruns the starting motor C) 30% speed D) 50% rated speed E) fuel is ignited
E) fuel is ignited
- Which device is not used to start a gas turbine:
A) small gas engines B) small Diesel engines C) pneumatic starters D) electric motors E) steamturbine expanders
A) small gas engines
- Remote gas pipeline stations use _____ for starting gas turbines
A) small gas engines B) small Diesel engines C) pipeline gas D) compressed air tigger motors E) electro-hydraulic motors
C) pipeline gas
- Turning gears are used to:
A) rotate the shaft every hour
B) rotate the shaft 90 degrees every hour
C) lower the stress on the starting motor
D) prevent the shaft from locking
E) prevents the shaft from developing flat spots
D) prevent the shaft from locking
- Turning gears require:
A) extensive cooling systems B) warm up and cool down on usage C) a method to engage or disengage the shaft D) variable frequency drive motors E) hydraulic coupling
C) a method to engage or disengage the shaft
- The first piece on an air intake system is:
A) mesh screen B) cooling coils C) heating coils D) guard filter E) drift eliminators
A) mesh screen
- The air intake duct is mounted above the gas turbine enclosure to:
A) lower the inlet air flow resistance B) keep the intake duct as short as possible C) make the enclosure more compact D) provide support for the filters E) place it in cleaner air
E) place it in cleaner air
- Inlet air temperatures to gas turbine are reduced by:
A) spray cooling B) fog cooling C) evaporative pads D) evaporative cooling E) refrigeration coils
D) evaporative cooling
- Anti icing systems are used to prevent:
A) plugging of filters with ice B) damage to the duct work from icing C) blade damage D) too Lowen intake air temperature E) compressor surging
C) blade damage
- Anti icing systems can cause:
A) wetting of the paper filter elements B) lowering of the unit pressure ratio C) higher temperatures on the back end of the turbine section D) less air flow throughput E) higher costs for little gain
D) less air throughput
- The preparation for startup of a gas turbine usually assumes:
A) subsystem checkout first B) turning on the cooling water C) starting some auxiliary systems D) automatic operation at remote sites E) it is done by operator interaction
D) automatic operation at remote sites
- When the gas turbine start button is pressed what will start first?
A) lubrication pump start B) hydraulic pump start C) ventilation fans start D) gas valves close E) permissive are checked
C) ventilation fans start
- Purging starts when:
A) the compressor runs up B) air flow is established C) compressor reaches maximum D) air flow reaches peak E) starter motor disengages
B) air flow is established
- Start up after a trip is done by:
A) satisfying all of the ‘permissives’
B) the operator initiating a restart
C) the computers re-initiating the startup
D) resetting of the system
E) selecting the manual restart on the screen
D) resetting of the system
- The recycle valve is used to:
A) load the compressor
B) recycle hot compressor air for inlet warming
C) allow the turbine to rapidly increase loading
D) control the combustion in the combustion chambers
E) recycle cooling air back to the combustion chamber
A) load the compressor
- Loading is started when:
A) the generator is at minimum B) after the warmup C) the recycle valve is fully open D) pressures stabilize E) the bleed valves are fully open
B) after the warmup
- A rapid decrease in gas turbine speeds can result in:
A) overcooling of the unit
B) high pressures in the compressor sections
C) high pressures in the turbine sections
D) failure of the recycle valve
E) combustion being interrupted
E) combustion being interrupted
- Prior to lighting off the turbines the operator must:
A) allow the speed to drop to idle B) allow the bleed valves to fully open C) check the guide vane position D) warm the turbine slowly E) open the fuel valves
D) warm the turbine slowly
- The first step in a normal gas turbine shutdown is:
A) close the fuel valve B) cool down the turbine C) reduce speed to idle D) open the recycle valve E) take load off the generator
C) reduce speed to idle
- Fast shutdowns should be avoided because______.
A) of the rapid cooldown
B) of increased wear on the unit
C) most gas valves cannot react quick enough
D) will cause other units to trip
E) can cause flexing of the compressor blades
B) of increased wear on the unit
- Turbine rotor speed on shutdown decreases once ______.
A) the cool down timer times out B) the shaft speed decreases below preset limit C) the turning gears takes over D) the fuel valve closes E) the main oil pump shuts down
D) the fuel valve closes
- Once the turbine rotor stops on some models _______.
A) the barring gear starts B) the cool down timer times out C) the auxiliary oil pump starts D) the main oil pump shuts down E) the jacking oil pump starts
A) the barring gear starts
- The fuel valve closing first on a shutdown is a sign of ______.
A) an operator error B) an emergency shutdown C) a failure of the post lube pump D) a failure of the cooldown timer E) a failure of the recycle valve
B) an emergency shutdown
- The purpose of a gas turbine water wash is to _______.
A) clean the unit front to back B) clean the combustion blades C) clean the gas headers injectors and burners D) clean the combustion chambers E) clean the compressor blading
E) clean the compressor blading
- The cleaning of a gas turbine is accomplished by _______.
A) taking the unit offline and washing each section individually
B) injecting cleaners into the gas or fuel system to clean the internals
C) shutting down the rotor
D) running a liquid or abrasive through the blades
E) injecting cleaners while the unit is running under load
D) running a liquid or abrasive through the blades
- A carbo blast cleaning consists of ____.
A) using carbon black to clean the unit
B) removing all the carbon by blasting it if with solvents
C) removing all the dirt by scrubbing the blades with rice
D) removing dirt and carbon with high pressure water
E) removing carbon from the gas passages, blades, and nozzles
C) removing all the dirt by scrubbing the blades with rice
- Water wash is accomplished by _____.
A) using hard water to scrub the blades
B) using scrub water mixed with sodium, potassium and vanadium
C) injecting water and cleaning solvents into the compressor
D) by adding cleaning solvents to the turbine at one half load
E) by scrubbing all parts with brushes and solvents
C) injecting water and cleaning solvents into the compressor
- Off line washing is performed by _____.
A) having the unit isolated and the speed at zero
B) injecting cleaners into the inlet at 50% rated speed
C) injecting cleaners at 30% rated speed
D) injecting cleaners into the inlet at zero shaft speed
E) injecting cleaners at crank speed
E) injecting cleaners at crank speed
- Water or steam injection reduces NOx emissions from a gas turbine by:
A) creating a reaction environment to bind the NOx compounds
B) preventing corrosion
C) dropping the combustion temperature
D) facilitating the production of H2NO3
E) allowing the removal of excess steam from the combustion process chamber
C) dropping the combustion temperature
- An example of an internal combustion engine is:
A) a Diesel engine B) a steam engine C) a steam turbine D) a gas turbine E) an air compressor
A) a Diesel engine
- A two stroke cycle engine has a power stroke every:
A) two crank shaft revolutions B) four crank shaft revolutions C) crank shaft revolution D) one half revolution E) one half revolution
C) crank shaft revolution
- The distinguishing characteristics of the gasoline engine are ______.
A) vaporized gasoline mixed with air is drawn into the cylinder during the intake stroke
B) ignition is achieved by means of a spark plug
C) governing takes place by throttling the air fuel mixture
D) the fuel is injected at high pressure
E) four stroke cycle
B) ignition is achieved by means of a spark plug
- The major differences of the Diesel engine compared to the gasoline engine are:
1) the charge drawn into the cylinder is air only
2) the fuel is injected at high pressure at the beginning of the compression stroke
3) ignition is due to the high temperature resulting from the compression of the air
4) the fuel is injected at high pressure at the end of the compression stroke
5) the fuel is injected into the engine cylinder at a high temperature
A) 1,3,4 B) 2,3,4 C) 3,4,5 D) 1,4,5 E) 2,4,5
A) 1,3,4
- Scavenging is:
A) the supplying of air for combustion
B) the removal of exhaust gases from the cylinder
C) used in all Diesel engines
D) usually used in four stroke cycle engines
E) recirculation of exhaust gases to reduce emissions
B) the removal of exhaust gases from the cylinder
- A two stroke cycle Diesel engine:
A) always has valves
B) has difficulty removing exhaust gas from the cylinder
C) are always of a uniflow type of action
D) always use scavenging air
E) requires oil mixed in the air for lubrication
B) has difficulty removing exhaust gas from the cylinder
- During the compression stroke of a Diesel engine, the temperature may be as high as ____.
A) 250 C B) 350 C C) 450 C D) 650 C E) 850 C
D) 650 C
- The oil scraper ring in a Diesel engine is located:
A) above the compression rings B) on the crank shaft C) on the bottom portion of the piston D) next to the camshaft E) in between the two compression rings
C) on the bottom portion of the piston
425 the pistons used on a Diesel engine are commonly made of ____ or _____.
1) stainless steel
2) aluminum alloy
3) carbon steel
4) cast iron
A) 1,3 B) 1,4 C) 2,3 D) 1,2 E) 2,4
E) 2,4
- An engine that has a/an ____ has the oil contained within the engine crankcase.
A) wet sump type B) dry sump type C) gravity feed reservoir D) outside storage E) underground storage
A) wet sump type
- Cylinder liners in Diesel engines are usually constructed of _____.
A) cast iron B) aluminum C) white metal D) carbon steel E) alloy steel
A) cast iron
- Diesel piston crowns are usually ______.
A) convex B) concave C) flat D) contoured E) none of the above
B) concave
- Most pistons in large internal combustion engines are provided with ____.
A) four rings B) three rings C) five rings D) six rings E) two rings
C) five rings
- Connecting rods are hollow bored to convey lubricating oil to the _____.
A) gudgeon pins B) pistons C) camshaft D) cylinder walls E) piston skirt
A) gudgeon pins
- Connecting rods are usually made of _____.
A) carbon steel B) forged steel C) aluminum D) cast iron E) aluminum alloy
B) forged steel
432 the purpose of the rocker arm is to operate ______.
A) the camshaft B) the push rods C) the oil pump D) the inlet valves E) the exhaust valves
D) the inlet valves
- The wet type of cylinder liner is _____.
A) water cooled B) oil cooled C) made of white metal D) submerged partly in oil E) all of the above
A) water cooled
- The fuel injector ____.
A) injects a mixture of fuel and air into the cylinder
B) injects fuel into the cylinder during the intake stroke
C) has a fuel injection nozzle
D) is used in conjunction with spark ignition
E) none of the above
C) has a fuel injection nozzle
- The purpose of the carburetor is to :
1) mix the fuel and air
2) atomized the fuel
3) heat the mixture of fuel and air
4) control the amount of air-fuel mixture to the engine
5) produce a vacuum to draw fuel into the engine
A) 1,2,3 B) 2,3,4 C) 1,2,3,4,5 D) 1,2,4,5 E) 1,3,4,5
D) 1,2,4,5
- The purpose of the coil in a battery ignition system is to:
A) increase the voltage to the plugs B) decrease the voltage to the plugs C) prevent an arc across points D) to protect the resister E) to interrupt the primary current quickly
A) increase the voltage to the plugs
- The choke in a carburetor produces a very rich air-fuel mixture for cold engine starts.
A) true
B) false
A) true
- A magneto ignition system:
A) does not require a coil B) produces AC power C) produces a hotter spark at high speeds D) does not require points E) does not require a condenser
C) produces a hotter spark at high speeds
- In the distributor system for the injection of fuel into a Diesel cylinder:
A) two pumps are used B) one pump is used C) one pump is used for each cylinder D) only a metering pump is used E) none of the above
A) two pumps are used
- In the common rail system used for injection of fuel into the Diesel cylinder:
A) the fuel is injected into the cylinder by the fuel pump
B) the fuel is injected into the cylinder by the injector
C) the system requires two pumps
D) the system does not require a return from the injector
E) the excess fuel returns directly to the inlet of the pump
B) the fuel is injected into the cylinder by the injector
