网友您好， 请在下方输入框内输入要搜索的题目：
题目内容
（请给出正确答案）
单选题
The crankshafts of medium speed engines are almost invariably solid （） from a single piece of steel.
A
forged
B
cast
C
made
D
shrunk
参考答案
参考解析
解析：
暂无解析
更多 “单选题The crankshafts of medium speed engines are almost invariably solid （） from a single piece of steel.A forgedB castC madeD shrunk” 相关考题
考题
Each cylinder liner on the marine medium speed engines _____.A.is usually cooled by sea waterB.can be replaced when worn outC.is in direct contact with the water in the bore of the cylinderD.can t expand when heated
考题
单选题One major disadvantage of a low-speed diesel as compared to a steam main-propulsion system is（）.A
the extra weight required for the diesel reduction gearingB
a minimum speed for the engines that limits the minimum speed of the vesselC
the higher fuel consumption per SHPD
the low efficiency of the system when a controllable pitch propeller is used
考题
单选题（）are increasingly used as main engine on merchant vessels, because they have a high Hp/Weight ratio.A
Slow speed diesel enginesB
Medium-speed diesel enginesC
Steam enginesD
Gasoline engines
考题
单选题The over-speed trip device installed in some diesel engines is automatically actuated by（）A
spring forceB
hydraulic pressureC
centrifugal forceD
mechanical linkage
考题
单选题On most diesel engines, the governor controls the output speed by （）.A
controlling the amount of fuel injected into the cylindersB
varying the speed of the turbochargerC
adjusting the compression ratioD
changing the timing of the fuel injection camshaft
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（） 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The majority of medium speed and high speed marine diesel engines for main or auxiliary drive operate on the （） cycle.A
two-strokeB
four-stokeC
long-strokeD
short-stroke
考题
单选题Each cylinder liner on the marine medium speed engines （）.A
is usually cooled by sea waterB
can be replaced when worn outC
is in direct contact with the water in the bore of the cylinderD
can t expand when heated
考题
单选题Medium speed engines have a （） power to weight ratio than the slow speed two strokes, but due to the higher speeds tend to have （） maintenance intervals.A
higher；reducedB
higher；increasedC
lower；reducedD
lower；increased
考题
单选题Marine four-stroke diesel engines are mainly （）.A
of crosshead typeB
of trunk piston typeC
of low speed typeD
all the above
考题
单选题Diesel engines are considered safer than gasoline engines because（）.A
they are more heavily builtB
the fuel used is less volatileC
they can be easily reversedD
they operate at a lower speed
考题
单选题In conventional systems, the injection pressure（）, while it’s（）in common rail diesel engines.A
fluctuates with the engine speed to some extent, independent of the engine speedB
keeps constant at all engine speed, dependent on the engine speed to some extentC
keeps constant at all engine speed, independent of the engine speedD
is decided by the engine speed, constant at all engine speed
考题
单选题Today, crankshafts for large 2-stroke crosshead engines are of the （）type.A
semi-builtB
built-upC
solid forgedD
individual forged
考题
单选题The reason why more and more of the large merchant vessels are being powered by medium-speed diesel engines is （）.A
they operate between 150 and 450 rpmB
they are connected to the propeller by gearingC
their smaller size and weightD
they can be connected directly to the propeller without gearing
考题
单选题The common rail engines show great advantages in combustion especially（）.A
at high speed and full loadB
at low speed and part loadC
when heavy fuel oil is used at seaD
when the ships run long distance
考题
单选题The crankshafts on the large modern 2-stroke crosshead engines are （）big （）makes as a single unit and so are constructed by joining together individual forgings.A
enough；toB
too；toC
such；soD
so；that
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Crankshafts of medium speed engines are （） from a single piece of steel.A
unusually solid weldedB
never be solid forgedC
almost invariably solid forgedD
almost invariably be welded
考题
单选题Although the crankshafts of medium diesel engines appear to be robust, they rely on the support of （） to develop their full strength.A
the piston rodsB
the crank throwsC
the thrust bearingsD
the main bearings
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Which of the listed types of starting systems is often used on large, low-speed, direct reversing, main propulsion diesel engines?（）A
ElectricB
HydraulicC
AirD
All of the above
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Pistons of marine medium speed diesel engines may be made of （） in order to keep the weight down for balancing purpose at high speed.A
leadB
forged steelC
alloy steelD
aluminum alloy
考题
单选题Most medium and slow speed diesels are started by what medium?（）A
Electric starting motorsB
HydraulicsC
Compressed airD
Ether
热门标签
最新试卷
