B1-1 Prime Movers And Engines Flashcards
A steam engine is very suited to applications where:
A) high rotational speed is required
B) power output is greater than 20 MW
C) slow rotational speed, without the use of reduction gearing is required
D) oil free exhaust steam is required
E) high torque at high speed is required
C) slow rotational speed, without the use of reduction gearing is required
A device that uses a working fluid to convert thermal energy to mechanical energy is called a/an: A) heat engine B) thermo-mechanical converter C) gas expander D) process engine E) electrical generator
A) heat engine
A steam engine piston:
A) can never have steam applied to either side
B) is lubricated from the crankcase oil by the splash method
C) moves fastest at the end of its stroke
D) moves fastest at the beginning of its stroke
E) never requires lubrication
D) moves fastest at the beginning of its stroke
A steam engine has the steam supply to the cylinder shut off once the piston has travelled: A) 15 to 20% of the stroke B) 25 to 35% of the stroke C) 45 to 55% of the stroke D) 75 to 95% of the stroke E) 100% of the stroke
B) 25 to 35% of the stroke
When checking bearings on an operating steam engine, an engineer should:
A) get accustomed to normal operating temperature and vibration by feeling the bearings
B) take note of the temperature displayed on the indicator
C) get accustomed to the odours of the operating equipment
D) check the oil quality leaving it
E) check the oil quantity leaving it
A) get accustomed to normal operating temperature and vibration by feeling the bearings
When deciding on the energy design of a power plant, the factor that is NOT of particular concern is the: A) system efficiency B) environment C) equipment costs D) customers' profile E) type of fuel to be burned
D) customers’ profile
Large power production plants tend to be of the thermal type because they can burn solid fuels and:
A) require the least amount of manpower
B) require little or no cooling water
C) they are the least expensive to build
D) the heat cycle they use is the most efficient
E) the noise level is much less than internal combustion engines
D) the heat cycle they use is the most efficient
In a large reaction turbine, the steam pressure drop occurs across the:
A) two sets of fixed nozzles and then two sets of moving blades
B) stationary blades and moving blades
C) fixed nozzles
D) moving blades
E) fixed nozzles and stationary blades
B) stationary blades and moving blades
The principle of an impulse turbine is that:
1) the steam pressure is reduced in the stationary nozzles
2) the high velocity steam will change direction through the moving blades
3) the steam pressure will drop across the moving blades
4) the steam pressure is increased through the nozzles
A) 1,2 and 3 only
B) 2,3 and 4 only
C) 1 and 2 only
D) 1,3 and 4 only
E) 1,2,3 and 4
C) 1 and 2 only
Generally, steam turbine blades are made of: A) high tensile ceramic B) cast iron C) carbon steel D) stainless steel E) brass
D) stainless steel
An example of a turbine which uses a condenser is a/an:
A) non-condensing extraction turbine
B) turbine exhausting to atmosphere
C) turbine exhausting to a vacuum
D) back pressure turbine
E) bleeder turbine exhausting at atmospheric pressure
C) turbine exhausting to a vacuum
The overspeed trip on a small turbine is actuated by: A) excess vibration B) high steam temperature C) centrifugal force D) high steam pressure E) excessive back pressure
C) centrifugal force
A steam turbine surface condenser:
1) produces a high vacuum at the turbine exhaust
2) decreases the pump power requirement in returning feedwater to the boiler
3) provides a source of high quality boiler feedwater
4) converts turbine exhaust steam back to water (condensate)
5) increases overall plant efficiency
A) 1,3,4 and 5 only
B) 2,3,4 and 5 only
C) 1,2,3 and 5 only
D) 1,2 and 4 only
E) 1 and 5 only
A) 1,3,4 and 5 only
The shafts of high output high temperature steam turbines are usually sealed using: A) oil sealed glands B) carbon rings C) packing glands D) water sealed glands E) labyrinth glands
E) labyrinth glands
Turbines often have segmental carbon ring sealing glands, which are held in place by: A) thrust runners B) labyrinths C) drive screws D) shrouding E) garter springs
E) garter springs
A cooling tower design that eliminates the use of fans and fill is the: A) induced draft tower B) hyperbolic tower C) chimney tower D) Venturi tower E) Bernoulli tower
D) Venturi tower
Cooling towers reduce water temperatures as a result of:
A) latent heat transfer between air and water in a shell and tube exchanger
B) purely latent heat transfer. As a result of the evaporation of a portion of the water
C) heat transfer between air and water in a shell and tube exchanger
D) sensible heat transfer to air and latent heat loss due to evaporation
E) purely sensible heat transfer from the warm water to the cooler air
D) sensible heat transfer to air and latent heat loss due to evaporation
Rate of heat transfer in any cooling tower depends upon:
1) relative velocity of air and water during contact
2) the type of wood used as the tower fill
3) length of contact time between the air and the wate
4) relative humidity of the air
5) the type of heat exchangers used in plant processes
A) 1,3 and 4 only
B) 2,3,4 and 5 only
C) 1,2,3 and 5 only
D) 1,2 and 3 only
E) 3,4 and 5 only
A) 1,3 and 4 only
Biological fouling of recirculating cooling water systems is prevented by:
A) the continuous feeding of poly phosphate chemicals
B) maintenance of the pH below 7.5
C) the use of induced electric currents
D) maintenance of the water temperature in excess of 80 degrees F
E) the shock feeding of biocides
E) the shock feeding of biocides
The purpose of a gas turbine regenerator is:
A) to increase the temperature in the combustion chamber
B) convert the open cycle to the closed one
C) to improve the thermal efficiency of the turbine
D) to lower the temperature in the combustion chamber
E) to reduce the for,action NOx and VOx
C) to improve the thermal efficiency of the turbine
Closed cycle gas turbines:
A) can develop more torque
B) require the use of highly refined fuel
C) are lighter in weight
D) recirculate the same fluid repeatedly through e compressor and turbine
E) can run faster than open cycle gas turbines
D) recirculate the same fluid repeatedly through the compressor and turbine
The air side of a gas turbine regenerator is located:
A) between the turbine and atmosphere
B) before the compressor
C) downstream of the compressor before the combustor
D) after the combustion chamber
E) between the turbine and combustion chamber
C) downstream of the compressor before the combustor
Early gas turbines were handicapped primarily by:
A) their inadequate power capability
B) the inability to get enough air into the combustion chamber
C) their high operating speeds
D) metal not being able to withstand high speed centrifugal forces
E) metals not standing the high temperature involved
E) metals not standing the high temperatures involved
Gas turbines are ideal when considering: A) long warm up periods B) automotive power C) emergency power generation D) good thermal efficiency E) cooling water pump operation
C) emergency power generation
A simple gas turbine is one without reheaters or: A) two shafts B) compressors C) regenerators D) combustors E) starting motors
C) regenerators
Some of the characteristics which make a gas turbine a better choice over other prime movers such as steam turbines are: 1) low maintenance 2) minimum cooling water 3) high thermal efficiency 4) rapid startup and loading A) 2 and 4 only B) 1,2 and 3 only C) 1,2 and 4 only D) 1,3 and 4 only E) 1,2,3 and 4
C) 1,2 and 4 only
A two stroke cycle gasoline engine:
A) does not require intake and exhaust valves
B) must have two cylinders
C) produces half as much power as a four stroke cycle engine
D) is of more complex construction than a four stroke cycle engine
E) has two power strokes per crank revolution
A) does not require intake and exhaust valves
Using a compressed air starting motor is a typical method of starting a: A) small two stroke engine B) jet engine C) large stationary Diesel engine D) high performance engine E) natural gas engine
C) large stationary Diesel engine
Compression ignition engines:
A) will compress air only on the compression stroke
B) will compress air only on the power stroke
C) need a carburetor to mix fuel with air
D) always have suction and discharge valves
E) require a spark timing device
A) will compress air only on the compression stroke
The two stroke gas engine finds application where:
A) only low quality fuels are available
B) maximum power with minimum size is required
C) large power output is required
D) high torque at low speed is required
E) low speed is required
B) maximum power with minimum size is required
Overloading of an individual cylinder in a Diesel engine is indicated by: A) a high exhaust temperature B) a high lube oil temperature C) a low exhaust temperature D) excessive oxygen in the exhaust E) excessive blower discharge pressure
A) a high exhaust temperature
In a compression ignition engine, fuel is normally ignited by: A) high voltage spark igniters B) a magneto spark C) a glow plug D) hot compressed air E) combustor crossfire chambers
D) hot compressed air
A four stroke cycle engine:
A) uses exhaust ports rather than valves
B) requires four strokes to produce one power stroke
C) has the intake valve open during the entire exhaust stroke
D) has a lower weight than an equivalently sized two stroke cycle engine
E) has four power strokes per crank revolution
B) requires four strokes to produce one power stroke
When checking bearings on an operating steam engine, an operator should:
A) check the oil quality leaving it
B) check the oil quantity leaving it
C) get accustomed to the odours of operating equipment
D) take note of the temperature displayed on the indicator
E) get accustomed to normal operating temperature and vibration by feeling the bearings
E) get accustomed to normal operating temperature and vibration by feeling the bearings
A steam engine piston:
A) has steam fed to it only through a fraction of its stroke
B) never requires lubrication
C) moves fastest near the end of its stroke
D) can never have steam applied to one side and then to the other side
E) is lubricated from the crankcase oil by the splash method
A) has steam fed to it only through a fraction of its stroke
A steam engine has the steam supply to the cylinder shut off once the piston has travelled: A) 15-20% on the stroke B) 25-35% of the stroke C) 45-55% of the stroke D) 75-95% of the stroke E) 100% of the stroke
B) 25-35% of the stroke
An example of a prime mover is a/an: A) centrifugal pump B) electric motor C) air compressor D) steam turbine E) boiler
D) steam turbine
A device not considered to be a prime mover is the: A) gas turbine B) electric motor C) Diesel engine D) hydraulic turbine E) steam engine
B) electric motor
During the operation of a steam engine, an indication that something is not functioning correctly is:
A) a change in the steam flow to the engine
B) a change in temperature of the supply steam
C) a change in the noise made by the engine
D) an increase in the output power of the driven generator
E) a change in temperature of the exhaust steam
C) a change in the noise made by the engine
The cross head of a steam engine:
A) does not require any bearing materials
B) imparts linear motion to the valve rod
C) is where linear motion becomes angular
D) does not require any lubrication
E) imparts angular motion to the piston
C) is where linear motion becomes angular
Generally, steam turbine blades are made of: A) cast iron B) stainless steel C) carbon steel D) brass E) high tensile ceramic
B) stainless steel
A large reaction turbine will have:
A) no thrust bearings
B) blades which are basically symmetrical in cross section
C) steam pressure dropping in only the moving blades
D) steam pressure dropping through moving and stationary blades
E) never more than 5 stages
D) steam pressure dropping through moving and stationary blades
The speed and power output of a steam turbine is regulated by the: A) steam extraction valves B) emergency overspeed trip C) steam intercept valves D) governor mechanism E) trip and throttle (T&T) mechanism
D) governor mechanism
The overspeed trip on a small turbine is actuated by: A) excessive back pressure B) high steam pressure C) high steam temperature D) excess vibration E) centrifugal force
E) centrifugal force
A steam turbine trip throttle valve:
A) regulates steam flow to the turbine to maintain a constant speed at all loads
B) regulates startup steam flow and shuts off steam in the event of overspeeding
C) regulates back pressure on a turbine regardless of load
D) regulates the steam flow to the turbine when the shaft increases above a maximum set speed
E) maintains a constant pressure in the steam chest
B) regulates startup steam flow and shuts off steam in the event of overspeeding
An example of a turbine which uses a condenser is a/an:
A) noncondensing extraction turbine
B) back pressure turbine
C) turbine exhausting to atmosphere
D) turbine exhausting to a vacuum
E) bleeder turbine exhausting at atmospheric pressure
D) turbine exhausting to a vacuum
A steam turbine should trip or shut down when normal operating speed is exceeded by: A) 250 rpm B) 100 rpm C) 50 rpm D) 10-15% E) 3-5%
D) 10-15%
Turbines often have segmental carbon ring sealing glands, which are held in place by: A) thrust runners B) labyrinths C) shrouding D) drive screws E) garter springs
E) garter springs
High discharge water temperature from a cooling tower may be a result of:
A) high wet bulb air temperature
B) high solids concentration in the cooling water
C) restriction of air flow through the tower
D) worn or dirty nozzles causing poor water breakup
E) all of the above
E) all of the above
To prevent basin freeze up, many smaller cooling towers are equipped with: A) natural gas fired duct burners B) direct contact propane burners C) hot water basin heating coils D) hot oil heating systems E) electric or steam coil basin heaters
E) electric or steam coil basin heaters
Biological fouling of recirculating cooling water systems is prevented by:
A) the continuous feeding of poly phosphate chemicals
B) maintenance of the pH below 7.5
C) maintenance of the water temperature in excess of 80*F
D) the shock feeding of biocides
E) the use of induced electric currents
D) the shock feeding of biocides
Cooling tower distribution nozzles should be cleaned at least: A) once per shift B) daily C) weekly D) monthly E) every three months
D) monthly
Dissolved and suspended solids can build up in a closed cooling tower system as the water evaporates. This buildup is controlled by:
A) treating the water supply to remove dissolved solids
B) scraping the scale from the cooling tower components on a regular basis
C) adding chemicals to remove dissolved solids
D) bleeding a portion of the water from the system continuously
E) shock feeding biocide once a week
D) bleeding a portion of the water from the system continuously
A gas turbine performs most effectively if: A) lube oil is of the proper viscosity B) cooling water temperature is kept low C) loaded immediately after starting D) ambient air temperature is low E) ambient air temperature is high
D) ambient air temperature is low
The main reason for the relatively low capital investment required for gas turbines compared to steam turbines is:
A) no need for long natural gas transmission lines
B) the need for less auxiliary equipment
C) a need for little or no operator training
D) no fuel pump required
E) the use of inexpensive materials in turbine construction
B) the need for less auxiliary equipment
The low installation coast of a gas turbine is:
A) because no fuel pump is required
B) because no electrical wiring is required
C) due to compact size of the equipment
D) because less auxiliary equipment is needed
E) due to inexpensive materials in the blades
D) because less auxiliary equipment is needed
Gas turbines are very popular where:
A) natural gas is not available in large quantities
B) thermal NOX pollution is of major concern
C) industrial sites are large allowing room for gas turbine installation
D) noise presents a problem
E) water is scarce
E) water is scarce
In a two shaft gas turbine:
A) the design is always of a closed cycle type
B) the design is always of an open cycle type
C) the shafts are interlocked and rotate at the same speed
D) the load turbine is downstream of the compressor turbine
E) the first turbine drives the prop on a turbo prop engine
D) the load turbine is downstream of the compressor turbine
An essential auxiliary in a gas turbine installation is the: A) condenser B) vacuum breaker C) regenerator D) starting motor E) extraction pump
D) starting motor
A simple gas turbine is one without reheaters or: A) two shafts B) starting motors C) regenerators D) compressors E) combustors
C) regenerators
A four stroke cycle engine:
A) has the intake valve open during the entire exhaust stroke
B) has four power strokes per crank revolution
C) has a lower weight than an equivalently sized two stroke cycle engine
D) requires four strokes to produce one power stroke
E) uses exhaust ports rather than valves
D) requires four strokes to produce one power stroke
The two stroke gas engine finds application where:
A) low speed is required
B) large power output is required
C) high torque at low speed is required
D) maximum power with minimum size is required
E) only low quality fuels are available
D) maximum power with minimum size is required
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 cylinder lawnmower E) two cycle transit bus
C) four stroke motocross motorcycle
The process of vaporization of gasoline and mixing with air for use in a naturally aspirated internal combustion engine is known as: A) oxidation B) fuel injection C) carburetion D) combustion E) supercharging
C) carburetion
One indication of incomplete combustion in a Diesel engine is: A) excessive combustion air B) a low exhaust temperature C) a high lube oil temperature D) excessive oxygen in exhaust E) a high exhaust temperature
E) a high exhaust temperature
An engine which develops one power stroke with every other turn of the crankshaft is the:
A) external combustion unit
B) V type engine
C) two stroke Diesel engine
D) four stroke natural gas engine
E) type which requires premixing lube oil and fuel
D) four stroke natural gas engine
Diesel engines require: A) fuel injectors B) a carburetor C) a distributor cap D) a magneto E) a spark plug in each cylinder
A) fuel injectors
