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
