Movers, Pump, Compressor & Lubrication Flashcards
A prime mover is:
a) an electric motor
b) a steam turbine
c) a centrifugal pump
d) an air compressor
e) a boiler
a) an electric motor
Large power production plants tend to be of the thermal type because they can burn solid fuels and:
a) they are the least expensive to build
b) the noise level is much less than internal combustion engines
c) the heat cycle they use is the most efficient
d) solid fuels are the most plentiful and cheapest
e) require the least amount of manpower
c) the heat cycle they use is the most efficient
A steam engine will have the steam supply to the cylinder shut off once the piston has travelled
a) 25 to 35% of its stroke
b) 75 to 90% of its stroke
c) 15 to 20% of its stroke
d) 55 to 65% of its stroke
e) 90 to 95% of its stroke
a) 25 to 35% of its stroke
The reciprocating motion of a steam engine is converted to rotary motion
a) at the end of the piston stroke
b) in the steam cylinder
c) via the valve eccentric
d) at the crankshaft
e) via the valve gear
d) at the crankshaft
The crosshead of a steam engine
a) imparts angular motion to the piston rod
b) is where linear motion becomes angular motion
c) imparts linear motion to the piston rod
d) does not require any lubrication
e) never requires any special bearing material
b) is where linear motion becomes angular motion
A steam engine piston
a) moves fastest at the end of its stroke
b) can never have steam applied to either side
c) is lubricated from the crankcase oil by splash method
d) moves fastest at the beginning of its stroke
e) never requires lubrication
d) moves fastest at the beginning of its stroke
A routine inspection of an operating steam engine should cover first and foremost
a) lubricators
b) drive belts
c) engine speed
d) steam temperature
e) steam quality
a) lubricators
Whenever feasibly possible, when checking bearings on running pieces of equipment it is wise to
a) check the oil quality leaving each
b) check the oil quantity leaving each
c) get accustomed to normal running temperature and
vibration by feel
d) smell the normal odours of the running bearing
e) observe the temperature on a thermometer
c) get accustomed to normal running temperature and
vibration by feel
One of the first ways to detect a fault in a reciprocating engine is
a) by sound
b) temperature indication
c) performance efficiency
d) by oil consumption
e) by smell
a) by sound
The slide valve of a steam engine is designed to
a) allow the piston to slide more freely
b) drain the condensate from the cylinder during warm-up
c) provide lubrication for the steam engine
d) provide for the steam to enter and leave the cylinder
e) prevent the engine from overspeeding
d) provide for the steam to enter and leave the cylinder
A steam turbine’s exhaust can often supply a process with steam because
a) processes always require a lower steam pressure
b) processes never require the high steam temperatures turbines do
c) turbine exhaust steam is always dry and saturated
d) it is free of oil
e) the steam will be at a temperature above the initial
temperature
d) it is free of oil
The exhaust steam from a steam turbine is more acceptable for process than the exhaust from a steam engine because
a) it is much hotter
b) it is easily controlled
c) it is free of oil
d) it is free of moisture
e) it contains more condensate
c) it is free of oil
The exhaust steam from a condensing steam turbine
____________ than the exhaust from a steam engine:
a) is drier
b) has more vapour
c) is more contaminated
d) is hotter
e) has more moisture
e) has more moisture
Turbines often have segmental carbon ring sealing glands which are held in place by
a) labyrinths
b) shrouding
c) drive screws
d) garter springs
e) thrust runners
d) garter springs
A steam turbine should trip or shut down when normal
operating speed is exceeded by:
a) 250 RPM
b) 3 to 5%
c) 50 RPM
d) 10 to 15%
e) 25 RPM
d) 10 to 15%
Condensing turbines:
a) are always impulse turbines
b) will have a vacuum in the last row of rotating blades
c) will use the condensate for heating
d) are very small units
e) cannot have counterflow stages
b) will have a vacuum in the last row of rotating blades
Which turbine uses a condenser?
a) back pressure turbine
b) a turbine exhausting to a vacuum
c) a bleeder turbine exhausting at atmospheric pressure
d) a non-condensing extraction turbine
e) a turbine exhausting to atmosphere
b) a turbine exhausting to a vacuum
The shrouding installed on the blading of a steam turbine serves to:
a) cool the blade tips
b) expand the steam
c) stop the steam flow
d) heat the steam
e) confine the steam to the blades
e) confine the steam to the blades
The turbine overspeed trip:
- prevents the turbine from vibrating
- prevents the turbine exceeding the maximum rated speed
- is operated by a spring loaded pin in the rotating blades
- will close the steam stop valve
- should be tested before the turbine is placed in service
a) 2, 4, 5
b) 2, 3, 4, 5
c) 1, 2, 4
d) 3, 4, 5
e) 4, 5
a) 2, 4, 5
The overspeed trip of a steam turbine:
a) operates on turbine vibrations due to high speed
b) is installed on all turbines
c) can be adjusted according to the load demand
d) is regulated by exhaust pressure
e) sheds the load in the event of high pressure
b) is installed on all turbines
Turbine overspeed trip:
a) prevents the turbine from vibrating
b) will close the steam stop valve to the turbine
c) is operated by a spring loaded pin in the rotating blades
d) supplies the operator with rpm indications
e) reduces the turbine speed by increasing the back pressure
b) will close the steam stop valve to the turbine
Turbine lubricating oil:
a) is not required for small impulse turbines
b) must be changed every four months
c) lubricates the blades
d) can be used to operate the turbine governor
e) should be preheated before use
d) can be used to operate the turbine governor
The purpose of turbine glands is to prevent:
a) water from entering the turbine
b) steam from entering the turbine
c) steam escaping from the turbine
d) steam from entering the lubrication system
e) oil from entering the turbine
c) steam escaping from the turbine
Shaft sealing in high output turbines is done with:
a) water seals
b) mechanical seals
c) wear rings
d) packing glands
e) labyrinth seals
e) labyrinth seals
When the steam pressure drop occurs in only the stationary members or components of a turbine, the turbine is known as:
a) a single stage unit
b) an impulse unit
c) a reaction unit
d) a Parsons unit
e) a cross compound reaction unit
b) an impulse unit
A large reaction turbine will have:
a) no thrust bearings
b) steam pressure dropping in only the moving sections
c) blades which are basically symmetrical in cross-section
d) never more than 5 stages
e) steam pressure dropping through moving and stationary sections
e) steam pressure dropping through moving and stationary sections
Turbine speed can be “fine tuned” with a device which will be limited to about 10% over the rated speed. This device is the:
a) governor valve
b) overspeed governor
c) sentinel valve
d) hand speed control
e) overspeed trip
d) hand speed control
Turbine thrust bearings are fixed to the casing and prevent axial movement of the spindle by contacting a component on the shaft known as a:
a) shaft sleeve
b) labyrinth
c) collar
d) shroud
e) diaphragm
c) collar
Shaft sealing carbon glands are:
a) lubricated by the main oil pump
b) limited to a temperature of 250 degrees C
c) replaced monthly due to erosion
d) self-lubricating
e) metal sprayed components
d) self-lubricating
The great majority of steam turbine governing systems utilize the:
a) hydraulic system principle
b) pneumatic system principle
c) mechanical centrifugal principle
d) lever principle
e) bimetal expansion principle
c) mechanical centrifugal principle
Reaction turbines:
a) have bucket shaped blades
b) have a pressure drop through the moving and stationary blades
c) are used for high pressures only
d) have a pressure drop in the moving blades only
e) have little axial thrust
b) have a pressure drop through the moving and stationary blades
In an impulse turbine:
a) the steam flow is reduced through the nozzles
b) the steam pressure is reduced in the nozzles
c) the steam pressure will drop across the blades
d) the steam velocity is increased through the blades
e) the exhaust steam is directed back to the boiler
b) the steam pressure is reduced in the nozzles
The steam turbine that has a pressure drop across
every set of blades is the __________ turbine.
a) double-stage impulse
b) single-stage impulse
c) topping
d) back pressure
e) reaction
e) reaction
When starting a steam turbine it is customary practice to:
a) analyze the oil for water prior to rolling
b) turn on all cooling water systems first
c) place the speed control system in service once the unit is rolling
d) test the overspeed trip as soon as running speed is
attained
e) stop the auxiliary oil pump as soon as steam begins to turn the unit
d) test the overspeed trip as soon as running speed is
attained
Reaction turbines:
a) have all of the steam pressure drop take place
in the stationary nozzle
b) have a velocity increase in the fixed blading
c) are used for higher speed only
d) have a velocity decrease through the fixed blading
e) require little blade sealing
b) have a velocity increase in the fixed blading
The average amount of water volume which evaporates from a cooling tower is:
a) 2%
b) 10%
c) 15%
d) 5%
e) 3.5%
d) 5%
Natural draft cooling towers operate most effectively in large open spaces and:
a) where wind is relatively constant
b) where relative humidity is high
c) where a large body of water is nearby
d) require a windbreak
e) must not be in direct sunlight
a) where wind is relatively constant
Excessive wind velocity in a natural draft cooling tower may cause:
a) louvers to become broken
b) high water drift or losses
c) rotation reversal of the fan
d) over-cooling of the water
e) under-cooling of the water
b) high water drift or losses
Compared to a crossflow tower, a counterflow tower:
a) is not as tall
b) has much less capacity
c) requires less floor space
d) requires more fan power
e) has a higher pressure drop
c) requires less floor space
Water contained in the airstream at the discharge of a
cooling tower is removed:
a) with centrifugal separators
b) by a series of chevron dryers
c) by refrigeration means
d) by a series of baffles
e) with drift eliminators
e) with drift eliminators
A cooling tower which requires neither fan nor fill is the:
a) natural draft unit
b) counterflow induced unit
c) venturi unit
d) crossflow unit
e) forced draft unit
c) venturi unit
A valve which prevents water flow over the fill of a tower during cold weather should not be closed until the:
temperature reaches
a) - 0.5 degrees C
b) + 0.5 degrees C
c) + 5 degrees C
d) + 20 degrees C
e) + 27 degrees C
e) + 27 degrees
To prevent cooling tower basin water from freezing during cold weather many units are equipped with:
a) ethylene glycol antifreeze systems
b) electric basin heaters
c) propane burners
d) ice defrosters
e) warming tapes
b) electric basin heaters
You are replacing the cooling tower fan motor bearings because:
a) the motor was running single phase
b) windings in the motor were faulty
c) a noise which sounded like a bad bearing was heard
d) the rotor was rubbing the stator
e) the gear reducer pinion shaft was misaligned
d) the rotor was rubbing the stator
Scaling is not as severe in towers when compared to boilers because:
a) tower water does not evaporate
b) there are not as many dissolved solids in tower water
c) pressure is not as high
d) temperatures are not as high
e) water is constantly being aerated
d) temperatures are not as high
A gas turbine compressor is usually:
a) centrifugal type
b) downstream of the turbine
c) dynamic axial design
d) downstream of the combustor
e) driven by a motor
c) dynamic axial design
The compressor on the 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) is always independently driven
e) is always a reciprocating type
a) can be driven by the load turbine
The combustion chamber of a gas turbine:
a) increases the pressure of the compressed air
b) is heated between the load turbine and the compression turbine
c) burns fuel with excess air
d) is water cooled
e) rotates at shaft speed
c) burns fuel with excess air
Many typical steam plant auxiliaries are eliminated with a gas turbine due to its:
a) small size
b) high speed
c) high power to weight ratio
d) simplicity
e) low oil consumption
d) simplicity
Gas turbines are very popular where:
a) noise does not present a problem
b) water is scarce
c) industrial sites are small and in congested areas
d) thermal pollution is of major concern
e) natural gas is plentiful
b) water is scarce
Gas turbines are ideal when considering:
a) long warm-up periods
b) emergency power generation
c) automotive power
d) cooling water pump operation
e) good thermal efficiency
b) emergency power generation
A two shaft gas turbine:
a) has the load turbine downstream from the compressor turbine
b) has the first turbine drive the prop on a turbo-prop engine
c) is always an open cycle type
d) is always a closed cycle type
e) does not require a starting motor
a) has the load turbine downstream from the compressor turbine
A gas turbine is not self-starting. It must be rotated at
__________ of its maximum speed before fuel is turned on.
a) 10% to 30%
b) 15% to 30%
c) 20% to 30%
d) 25% to 30%
e) 25% to 50%
c) 20% to 30%
Early gas turbines were handicapped by:
a) metal not being able to withstand high speed centrifugal forces
b) the inability to get enough air into the combustion
chamber
c) metals not standing the high temperatures involved
d) their high operating speeds
e) their inadequate power capability
c) metals not standing the high temperatures involved
The temperature to which the air can be raised at the turbine inlet is:
a) an indication of a unit’s power
b) directly related to the unit’s size
c) a function of the air compressor input
d) an indication of the unit’s efficiency
e) important for proper compressor performance
d) an indication of the unit’s efficiency
The output power of a gas turbine is directly related to the:
a) mass of gas passing through the turbine per second
b) temperature at the turbine inlet
c) mass of the unit
d) slippage between the turbine and compressor
e) turbine exhaust temperature
a) mass of gas passing through the turbine per second
The low installation cost of a gas turbine is:
a) due to cheap materials in the blades
b) due to short fuel lines
c) because no fuel pump is required
d) because no electrical wiring is required
e) because less auxiliary equipment is needed
e) because less auxiliary equipment is needed
Some of the characteristics which make the gas turbine a better choice over other prime movers are:
- low maintenance
- minimum cooling water
- high thermal efficiency
- rapid start-up and loading
a) 1, 2, 3, 4
b) 1, 2, 3
c) 1, 2, 4
d) 1, 3, 4
e) 2, 3, 4
c) 1, 2, 4
The air side of a gas turbine regenerator is located:
a) before the compressor
b) after the combustion chamber
c) between the turbine and combustion chamber
d) between the turbine and atmosphere
e) downstream of the compressor
e) downstream of the compressor
A gas turbine performs most effectively if:
a) lube oil is of the proper viscosity
b) cooling water temperature is kept low
c) ambient air temperature is high
d) ambient air temperature is low
e) loaded immediately after starting
d) ambient air temperature is low
A combined steam and gas turbine arrangement can be termed:
a) an ideal system
b) a cogeneration system
c) a once through system
d) ideal relative to system efficiency
e) a high capacity system
b) a cogeneration system
The purpose of a regenerator is:
a) to clean the exhaust gases
b) to improve the efficiency of the turbine
c) to increase the temperature in the combustion chamber
d) to lower the temperature in the combustion chamber
e) to recirculate the exhaust gases back through the compressor
b) to improve the efficiency of the turbine
In a compression ignition engine the fuel is ignited by:
a) an electric spark
b) the compressed air temperature
c) the atomized fuel
d) a cross-combustor
e) compressed air pressure
b) the compressed air temperature
Diesel engine governing is accomplished by:
a) varying the fuel quality
b) carburetion
c) varying the fuel quantity
d) fuel atomizing air quantity
e) fuel atomizing air pressure
c) varying the fuel quantity
The fuel for a diesel engine is:
a) light fuel oil
b) vaporised by a carburettor
c) mechanically atomized by high pressure
d) atomized before the cylinder
e) mixed with air before the cylinder
c) mechanically atomized by high pressure
Four-stroke cycle engine valves are:
a) operated by cams
b) of the pressure differential variety
c) a number of ports in the cylinder wall
d) often termed reed or channel valves
e) always open as the piston travels upwards
a) operated by cams
An engine which develops one power stroke with every other turn of the crankshaft is the:
a) two stroke diesel engine
b) type which requires pre-mixing lube oil and fuel
c) four stroke natural gas engine
d) V type engine
e) external combustion unit
c) four stroke natural gas engine
Four cycle engine lubrication is usually:
a) forced by pump
b) by gravity oilers
c) by the scoop method
d) by the dip tube method
e) by grease fitting
a) forced by pump
An example of an engine which gives high torque at low speeds would be that of a:
a) chain saw
b) two cycle snowmobile
c) four stroke motocross motorcycle
d) two cycle lawnmower
e) two cycle transit bus
c) four stroke motocross motorcycle
A two cycle engine:
a) must always have lube oil premixed with the fuel
b) can never have a crankcase lubrication system
c) can never be operated in an inverted position
d) “pops” twice as often as an equivalent cylinder four
stroke engine
e) gives one power stroke every other crankshaft revolution
d) “pops” twice as often as an equivalent cylinder four
stroke engine
Pre-mixing lube oil and fuel or having a special lube oil
injection system is typical of the average:
a) snowmobile engine
b) automobile engine
c) aircraft engine
d) tractor engine
e) heavy equipment engine
a) snowmobile engine
A major difficulty encountered with a two-stroke cycle engine is:
a) the high torque at low speeds
b) maintenance of many moving parts
c) the difficulty in cold weather starting
d) the high speeds compared to an equivalent four stroke
engine
e) exhausting the spent gases from the cylinder
e) exhausting the spent gases from the cylinder
A two cycle gasoline engine:
a) has more moving parts than a four cycle
b) produces twice as much power as a four cycle
c) must have two cylinders
d) does not require exhaust valves
e) is of more simple construction than a four cycle
e) is of more simple construction than a four cycle
Cylinder scavenging:
a) is more efficient in a 2 cycle engine than a 4 cycle type
b) is scoring the cylinder by a broken piston ring
c) is the removal of exhaust gases from the cylinder
d) prevents the air from entering the cylinder
e) removes excessive oil from the cylinder walls
c) is the removal of exhaust gases from the cylinder
The purpose of a spark plug is:
a) to ignite the fuel air mixture in a gasoline engine
b) to produce power for the compression stroke
c) to prewarm the engine
d) to raise the ignition point of the fuel
e) to ignite the air in the cylinder
a) to ignite the fuel air mixture in a gasoline engine
Compression ignition engines:
a) need suction end discharge valves
b) will compress air only on the compression stroke
c) need a carburettor to mix the fuel with the air
d) will compress air only on the power stroke
e) require a spark timing device
b) will compress air only on the compression stroke
The injection pump of a diesel engine is driven by:
a) piston action
b) the governor
c) the wrist pin
d) the gudgeon pin
e) the camshaft
e) the camshaft
Ignition in a diesel engine is started by:
a) a glow plug
b) a spark plug
c) a starter motor
d) compression in the cylinder
e) air injection
d) compression in the cylinder
Using a compressed air starting motor is a popular method of starting a:
a) large stationary diesel engine
b) small two stroke engine
c) jet engine
d) high performance engine
e) natural gas engine
a) large stationary diesel engine
When using compressed air to each cylinder for starting purposes, the pressure is approximately:
a) 520 kPa
b) 255 kPa
c) 3,030 kPa
d) 2,100 kPa
e) 435 kPa
d) 2,100 kPa
Reduction in sealing qualities between the piston rings and cylinder wall by the lube oil may be the result of:
a) low cooling water temperature
b) high lube oil viscosity
c) high cooling water temperature
d) high carbon residue of the lube oil
e) wrong fuel being used
c) high cooling water temperature
A pump is capable of suction lift due to a) its ability to convert kinetic energy into potential energy b) the speed at which it operates c) its input power d) its size e) atmospheric pressure
e) atmospheric pressure
Centrifugal pumps do not develop good suction lift because:
a) atmospheric pressure is usually too low
b) the pumped medium relative density is too high
c) their internal component clearances are too high
d) the speed is too low
e) they favour pressure rather than volume
c) their internal component clearances are too high
It is generally accurate to say that:
a) 9.8 kPa pressure results from every metre of water depth or height
b) a water height or depth of 10.34 metres results in 1 kPa
c) 1 kPa will result from a water head of 9.8 metres
d) 10.21 kPa will result from 1 metre of static water head
e) atmospheric pressure has no bearing on static water head
a) 9.8 kPa pressure results from every metre of water depth or height
Preferably, dynamic pumps should be located:
a) directly under the liquid source when suction lift is
involved
b) above the liquid source when suction head is involved
c) above the liquid source when suction lift is involved
d) at the liquid source level when suction lift is involved
e) below the liquid source when suction head is involved
e) below the liquid source when suction head is involved
The vertical distance from the liquid surface up to the pump centre-line plus the vertical distance from the pump centre-line up to the surface of the liquid in the discharge tank is:
a) static discharge head
b) static suction head
c) suction lift
d) total discharge head
e) total static head
e) total static head
The difference between static suction head and static
discharge head is:
a) total static head
b) static discharge head
c) static suction head
d) equivalent head
e) dynamic head
a) total static head