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
Valve cages are used on some large diesel engines to （）
A
reduce wear on the valve stem
B
permit the use of alloy valve seat materials
C
reduce heat transfer from the valve seat
D
facilitate valve removal for servicing
参考答案
参考解析
解析：
暂无解析
更多 “单选题Valve cages are used on some large diesel engines to （）A reduce wear on the valve stemB permit the use of alloy valve seat materialsC reduce heat transfer from the valve seatD facilitate valve removal for servicing” 相关考题
考题
Diesel engines driving alternators operating in parallel must maintain a set frequency regardless of load changes. The governor characteristic used to accomplish this is known as _______.A.actuationB.sensitivityC.compensationD.promptness
考题
Vessels required to be equipped with an approved backfire flame arrester are ______．A.Those with diesel enginesB.All those with gasoline enginesC.Those with large engines onlyD.None of the above
考题
A Kort nozzle is a(n) ______.A.hollow tube surrounding the propeller used to improve thrustB.nozzle attached to a firefighting hoseC.intake valve on a diesel engineD.piston cylinder on a diesel engine
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In large marine diesel engines cylinder oils usually contain additives formulated to impart the （） to clean the rings and grooves.A
inefficiencyB
oilinessC
detergencyD
purity
考题
单选题Thermocouple pyrometers are used on large, main propulsion diesel engines to indicate the temperature of the（）A
cooling water leaving each cylinderB
fuel oil entering the injectorC
exhaust gases at various locationsD
lube oil at the bearing supplies
考题
单选题Mist detectors used on large low-speed main propulsion diesel engines monitor and check for the presence of （）.A
fuel oil vapor at the sludge tank ventB
unburned fuel vapors in the scavenge air receiverC
lube oil vapors in the crank caseD
lube oil vapors in the engine room
考题
单选题Which of the following methods is used to prevent throttling of compressed air through the diesel engine air starting valves?（）A
Holding the valve open for a long periodB
Increasing the starting air pressure usedC
Opening the stating air valve quicklyD
Reducing the starting air valve size
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（）, so they are widely used on board ship nowadays.A
Diesel engines have more advantages in comparison with gasoline enginesB
Diesel engines have more advantages in comparison to gasoline enginesC
Gasoline engines have more advantages in comparison with diesel enginesD
Gasoline engines have more advantages in comparison to diesel engines
考题
单选题Exhaust valve openings in a diesel engine cylinder head are made as large as practical to （）A
increase back pressure during the exhaust processB
facilitate periodic replacement of the valvesC
reduce the pumping loss associated with scavengingD
reduce tension on valve springs
考题
单选题One method of constructing large marine diesel engines and reducing the total engine frame weight is through （）.A
casting interlocking componentsB
welding plates to form sections for assemblyC
forging integral componentsD
case hardening integral components
考题
单选题Some diesel engines are supercharged with a （）A
slam chargerB
turbochargerC
fuel atomizerD
fuel injector
考题
单选题（） the engines, the diesel engine is（） used engine on board.A
Between；more commonlyB
Among；the most commonlyC
Between；not more commonlyD
Among；not the most commonly
考题
单选题Vessels required to be equipped with an approved backfire flame arrester are（）.A
those with diesel enginesB
all those with gasoline enginesC
those with large engines onlyD
None of the above
考题
单选题An electric heater built into some smaller diesel engines is used to （）.A
raise lube oil viscosity for easier starting in cold weatherB
increase air inlet temperatureC
increase compression ratioD
increase jacket water temperature for easier starting in cold weather
考题
单选题（） providing lubricating films, oil used in marine diesel engines have to remove heat from oil cooled piston.A
Except forB
BesideC
ExceptD
In addition to
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Cast iron pistons used in large propulsion diesel engines are constructed with （）A
not taper what so everB
the skirt being tapered and smaller than the crownC
the skirt being tapered and larger than the crownD
the crown being tapered and smaller than the skirt
考题
单选题A Kort nozzle is a(n)（）.A
hollow tube surrounding the propeller used to improve thrustB
nozzle attached to a firefighting hoseC
intake valve on a diesel engineD
piston cylinder on a diesel engine
考题
单选题A waste heat boiler is installed on some diesel propelled vessels to （）.A
provide steam for emergency propulsionB
provide steam for the turbo-generatorC
heat the waste water tanksD
steam for warming engines
考题
单选题The direct acting mechanical governor used with some small diesel engines, controls fuel flow to the engine by（）A
governor flyweight action on a pilot valve which controls fuel injectionB
governor flyweight motion acting on fuel controls through suitable linkageC
positioning a butterfly valve in the fuel delivery system positioningD
a servomotor piston attached to the fuel controls
考题
单选题Turbocharged four-stroke/cycle diesel engines utilize valve overlap for（）.A
improving cylinder scavengingB
preheating the combustion chamberC
reducing air charge densityD
preventing valve wear
考题
单选题Which lubricating oil additive is used in diesel engines to reduce the tendency for sludge and varnish to form on the engine parts?（）A
Flash point improversB
Pour point improversC
InhibitorsD
Foam suppressors
考题
单选题In some type of two-stroke engines, besides some small holes for（）, starting valve, safety valve, indicator cock, and central opening in each cylinder cover for mounting the（）A
fuel valves；exhaust valveB
exhaust valves；inlet valveC
fuel valves；inlet valveD
exhaust valves；fuel valve
考题
单选题In some modern large diesel engines, which of the following is used as the support for the main bearings?（）A
BedplateB
BlockC
BaseD
Sump
热门标签
最新试卷