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单选题
In a diesel engine,（） works as working medium and changes the heat energy to mechanical energy, changes the reciprocating movement to rotary moment（）
A
fuel spray； the burning of the fuel
B
the burned gas mixture； connecting rod
C
medium shaft；crankshaft
D
the burned gas mixture； piston rod
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更多 “单选题In a diesel engine,（） works as working medium and changes the heat energy to mechanical energy, changes the reciprocating movement to rotary moment（）A fuel spray； the burning of the fuelB the burned gas mixture； connecting rodC medium shaft；crankshaftD the burned gas mixture； piston rod” 相关考题
考题
On a medium-speed main propulsion diesel engine, the crank-pin or crank journalbearings receive lubricating oil from( ).A.a spindle lubricatorB.an oil jetC.internal splashingD.drilled passages in the crankshaft
考题
One cylinder of a diesel engine is persistently knocking and does not cease(停止) when the fuel supply to that cylinder is secured.Which of the following problems may be the cause?A.Low loading of the cylinderB.Excessive cooling of that pistonC.Sluggish ring action on the pistonD.A mechanical defect in a working part
考题
单选题The marine diesel engine is a type of diesel engine used on ships The （） of its operation is not very difficult to understand.A
principleB
principalC
causeD
case
考题
单选题Before shutting off the fuel supply to stop a medium or high–speed diesel engine, why is it necessary to allow the engine to idle for a few minutes?（）A
To prevent internal damage form local overheatingB
To ensure the fuel nozzles are flushed cleanC
To clear the smoke stackD
To let the waste heat boiler reduce its rate of steam generation
考题
单选题In a diesel engine, offers the heat energy directly（）； works as working medium and changes the heat energy to mechanical energy（）A
the burning of the fuel； medium shaftB
fuel spray； fresh airC
fuel； fuel sprayD
the burning of the fuel； the burned gas mixture
考题
单选题A supercharged diesel engine when compared to a similar naturally aspirated diesel engine, will develop an increase in （）A
ignition lagB
engine horsepowerC
lube oil system pressureD
specific fuel consumption
考题
单选题（） can be found on most medium to large merchant vessels even if the main engine is either a steam turbine or 2-stroke crosshead engine.A
The medium speed 4-stroke trunk piston engineB
The low speed 2-stroke crosshead engineC
The medium speed 2-stroke crosshead engineD
The low speed 4-stroke trunk piston engine
考题
单选题Starting a large low-speed propulsion diesel engine on diesel fuel during cold weather conditions, will be made easier by （）A
increasing the quantity of starting airB
increasing the lube oil pressureC
heating the engine fuel supplyD
heating the engine coolant
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Why a gearbox is needed in a ship driven by a medium-speed diesel engine?（）A
To reduce the main engine speedB
To increase the main engine speedC
To govern the main engine speedD
To fix the propeller shaft
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What is the effect of heated intake air on a diesel engine? （）A
Increases efficiencyB
Increases engine horsepowerC
Increases engine lifeD
Reduces engine horsepower
考题
单选题A disadvantage of a four-stroke/cycle diesel engine is （）A
higher working temperature of piston and cylinderB
the use of scavenge portsC
fewer power strokes per revolution of the crankshaftD
part of the fuel is burned as the piston is moving away from top dead center
考题
单选题The Total Base Number (TBN) value of diesel engine lube oil refers to its ability to （）A
resist changes in viscosity with changes in temperatureB
resist emulsificationC
neutralize acidsD
resist oxidation at high temperatures
考题
单选题Some medium and high-speed diesel engines require reduction gear units to provide a useful propeller speedIn most reduction gears, the bull gear（）A
must churn the oil in the sumpB
is connected to the propeller shaftC
is driven at the highest RPMD
compensates for alignment variations between the engine and pinion gear
考题
单选题When used with reversing reduction gears, medium-speed diesel engines should be bolted to their foundations with fitted bolts at the drive end and clearance(loosely fitted) bolts in other locations √This is done to （）A
maintain alignment when the ship’s hull is working in heavy seasB
ensure engine vibrations correspond to the natural frequency of the hullC
permit the engine to expand away from the driven equipment as the engine heats up and expandsD
maintain engine thrust bearing clearances
考题
单选题Poor quality fuel being used in a turbocharged medium-speed, diesel engine could result in （）A
hard startingB
excessive fuel consumptionC
loss of powerD
all of the above
考题
单选题One of the differences between a two-stroke engine and a four-stroke engine is,（）A
a two-stroke engine works without exhaust operationB
a two-stroke engine works without compression strokeC
a two-stroke engine works without expansion strokeD
a two-stroke engine works without suction operation
考题
单选题A disadvantage of a two-stroke/cycle diesel engine is（）A
more power strokes per revolutionB
the use of scavenge airC
more complicated valve gearD
higher working temperature of the piston and cylinder
考题
单选题The term medium speed diesel engine is currently taken to mean an engine with an operating rotational speed of （） rpm.A
below 300B
above 1200C
between 300 to 1200D
below 1200
考题
单选题Prior to starting most medium-speed propulsion diesel engines, which of the procedures listed should be observed?（）A
The expansion tank should be topped offB
The thermostatic water regulating valves should be manually openedC
The fuel filters should be changedD
The engine should be turned over slowly with the indicator cocks open
考题
单选题On a turbo-charged, medium-speed diesel engine, which of the following problems is an indication of a restricted air intake passage?（）A
Engine is hard to startB
Engine missesC
Surges at governed RPMD
Coolant temperature is too low
考题
单选题When the diesel is stopped, which of the following items is wrong?（）A
keep all systems in normally runningB
the main engine is stand-byC
shut off the starting air bottle outlet valveD
pay attention to the changes of the system parameters
考题
单选题On a diesel engine equipped with an isochronous governor, if the “speed droop” control is reduced to the “zero” setting, the engine （）A
speed will drop drastically with any increase in loadB
will stop due to zero fuel supplyC
will stall upon application of loadD
speed will remain fairly constant despite load changes
考题
单选题The diesel engine is a type of （）.A
turbine engineB
gas turbineC
steam engineD
internal combustion engine
考题
单选题Compared to a naturally aspirated diesel engine, a supercharged diesel engine has（）A
a cylinder air charge of higher pressureB
increased pumping lossesC
less valve overlapD
reduced blow-by
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