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单选题
The speed of the turbocharger for a four-stroke/cycle diesel engine driving a generator at constant speed depends on the ()
A
engine speed
B
kilowatt load
C
fuel injection pressure
D
air intake manifold temperature
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更多 “单选题The speed of the turbocharger for a four-stroke/cycle diesel engine driving a generator at constant speed depends on the ()A engine speedB kilowatt loadC fuel injection pressureD air intake manifold temperature” 相关考题
考题
Proper lubrication of the main bearings is more easily obtained in a single acting, four-stroke/cycle diesel engine than in a tow-stroke/cycle diesel engine because________.A.The direction of pressure on the journal in four-stroke engine is continuouslyB.positive feed lubricators are installed on all bearings of four-stroke engine, whereas as a splash feed system is used on tow-stroke engineC.four-stroke engines usually utilize a heavier grade of oil than tow-stroke enginesD.Low-stroke engines usually consume less lube oil than four-stroke engines
考题
If all other conditions such as bore, stroke, speed, and mean effective pressures are equal, a two stroke/cycle diesel engine will develop approximatelyA.the same indicated horsepower as a four-stroke/cycle engineB.twice the indicated horsepower as a four-stroke/cycle engineC.one half the indicated horsepower as a four-stroke/cycle engineD.one power stroke for every two crankshaft revolutions
考题
During the valve overlap period, the exhaust pressure of a turbocharged four-stroke/cycle diesel engine must be less than the intake manifold pressure to ensure ______.A.effective cylinder scavenging and coolingB.constant pressure from the turbochargersC.cooler operation of the exhaust systemD.effective constant pressure for turbocharger operation
考题
单选题Compared to four-stroke/cycle engines, two-stroke/cycle diesel engines have the disadvantage of ()A
less even torqueB
higher cylinder head temperaturesC
fewer power strokes per revolutionD
greater weight/size requirements
考题
单选题If the turbocharger of a four-stroke/cycle diesel engine fails to operate, which of the following statements best describes the probable effect?()A
Intake manifold pressure will be highB
Intake manifold pressure will be unaffectedC
Exhaust temperatures will be highD
Exhaust temperatures will be low
考题
单选题Typical marine propulsion plants include() directly coupled to the vessel’s single large-diameter, fixed-pitch propeller.A
a single, long-stroke, slow-speed, turbocharged, two-stroke diesel engineB
a single, long-stroke, medium-speed, turbocharged, four-stroke diesel engineC
two medium-speed, turbocharged, four-stroke diesel enginesD
a variable-speed AC generator
考题
单选题The camshaft drive is designed to maintain proper camshaft speed relative to crankshaft speedIn maintaining this relationship, the camshaft drive causes the camshaft to rotate at()A
one half crankshaft speed in a two-stroke cycle diesel engineB
crankshaft speed in a two-stroke cycle diesel engineC
two times crankshaft speed in a two-stroke cycle diesel engineD
one-fourth times crankshaft speed in a four-stroke cycle diesel engine
考题
单选题Air motion is induced in a four-stroke/cycle diesel engine cylinder to improve air fuel mixing, and is known as()A
superchargingB
scavengingC
turbulenceD
swept volume charging
考题
单选题The size of the exhaust valve opening is ()A
most critical in a four-stroke cycle diesel engineB
most critical in a two-stroke/cycle diesel engineC
most critical in a four-stroke/cycle diesel engine if it is turbochargedD
of equal importance in a two-stroke/cycle diesel engine as in a four-stroke/cycle diesel engine
考题
单选题Proper lubrication of the main bearings is more easily obtained in a single acting, four-stroke/cycle diesel engine than in a tow-stroke/cycle diesel engine because().A
The direction of pressure on the journal in four-stroke engine is continuouslyB
positive feed lubricators are installed on all bearings of four-stroke engine, whereas as a splash feed system is used on tow-stroke engineC
four-stroke engines usually utilize a heavier grade of oil than tow-stroke enginesD
Low-stroke engines usually consume less lube oil than four-stroke engines
考题
单选题When would the available energy of the exhaust gases of a two-stroke/cycle diesel engine be insufficient to drive an exhaust gas turbocharger, resulting in the incorrect amount of air for combustion?()A
During operation at low speedB
During operation at rated speed, but low power outputC
During accelerationD
All of the above
考题
单选题During the valve overlap period, the exhaust pressure of a turbochargers, four-stroke/cycle diesel engine must be less than the intake manifold pressure to ensure ()A
effective cylinder scavenging and coolingB
constant pressure from the turbochargersC
cooler operation of the exhaust systemD
effective constant pressure for turbocharger operation
考题
单选题Proper lubrication of the main bearing is more easily obtained in a single acting four-stroke/cycle diesel engine than in a single acting two-stroke/cycle diesel engine because ()A
bearing pressure in a four-stroke/cycle acting single diesel engine is continually reversedB
bearing pressure in a two-stroke/cycle single acting diesel engine is continually reversedC
the maximum bearing pressure is higher in a single acting two-stroke/cycle diesel engineD
two-stoke/cycle diesel engines require more complicated lubrication piping
考题
单选题Which of the following statements is true regarding the installation of piston rings on two-stroke/cycle, diesel engines as compared to four-stroke/cycle, diesel engines?()A
In a two-stroke/cycle engine, the rings run hotter, requiring the end gap to be greaterB
Some provision must be made in a two-stroke/cycle engine to keep the rings from binding in the portsC
No gap is required to exist between the ends of the ring when cold in a two-stroke/cycle engine, but a small gap is required in a four-stoke/cycle engineD
The gaps should be staggered on either side of a piston in a two-stroke/cycle engine, while staggering is not necessary in a four-stroke/cycle engine
考题
单选题If all other conditions such as bore, stroke, speed, and mean effective pressures are equal, a two-stroke/cycle diesel engine will develop approximately()A
the same indicated horsepower as a four-stroke/cycle engineB
twice the indicated horsepower as a four-stroke/cycle engineC
one half indicated horsepower as a four-stroke/cycle engineD
one power stroke for every two crankshaft revolutions
考题
单选题A two-stroke/cycle diesel engine requires less starting air than a four-stroke/cycle diesel engine, of equal displacement, because the two-stroke/cycle diesel engine()A
has little or no internal frictionB
has a lower effective compression ratioC
operates with scavenge air under a positive pressureD
operates without energy absorbing intake and exhaust strokes
考题
单选题If a four-stroke/cycle diesel engine is running at 1550 RPM, the speed of the camshaft will be().A
525 RPMB
775 RPMC
1550 RPMD
1800 RPM
考题
单选题During which of the listed piston stroke of a four-stroke/cycle diesel engine, is the piston moving downward?()A
Intake strokeB
Compression strokeC
Exhaust strokeD
Pumping stroke
考题
单选题Fuel oil begins injection into the cylinder of a four-stroke/cycle diesel engine during the ().A
intake strokeB
exhaust strokeC
power strokeD
compression stroke
考题
单选题For a given size engine, the two-stroke/cycle diesel engine will deliver more power than a four-stroke/cycle diesel engine because ().A
it has a longer power strokeB
more air gets into the cylinder each strokeC
it develops twice as many power strokes at the same speedD
higher combustion pressure is developed
考题
单选题If the speed of a turbocharged diesel engine is maintained constant the turbocharger speed will ()A
decrease until the engine speed increasesB
increase as the load increasesC
decrease as the loadD
increases remain unchanged
考题
单选题In a main propulsion turbocharged diesel engine, the speed of the turbocharger varies according to the ()A
governor droopB
speeder spring tensionC
fuel rack lagD
load on the engine
考题
单选题A turbocharged, four-stroke/cycle diesel engine has a larger valve overlap than a naturally aspirated four-stroke/cycle diesel engine, in order to in crease the ().A
temperature of the exhaust gasesB
energy supplied to the turbochargerC
air pressure to the intake manifoldD
purge of exhausted gases from the cylinders
考题
单选题A four-stroke/cycle, 1000horsepower diesel engine fails to start at normal cranking speed with normal fuel pressure and ambient temperatureThe reason for the failure could be()A
glazed liners or pistonsB
high lube oil pressureC
excessive compression ratioD
worn valve seats and valves
考题
单选题The camshaft on a four-stroke/cycle diesel engine provides a means to operate the ().A
fuel injectorsB
exhaust valvesC
intake valvesD
all of the above
考题
单选题A piston in a four-stroke/cycle diesel engine makes four strokes during each ().A
crankshaft revolutionB
mechanical cycle of operationC
period of two combustion cyclesD
cycle of two events
考题
单选题In a four-stroke/cycle diesel engine, the camshaft rotates at ()A
twice the crankshaft speedB
half the crankshaft speedC
the same speed as that of the crankshaftD
a speed independent of that of the crankshaft
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