单选题A diesel engine should not be operated at low loads for long periods of time because（）A heavy carbon deposits will buildup on the valves and in the exhaustB fuel dilution is increased at low loadC exhaust valves may be damagedD all of the above

题目
单选题
A diesel engine should not be operated at low loads for long periods of time because（）
A

heavy carbon deposits will buildup on the valves and in the exhaust

B

fuel dilution is increased at low load

C

exhaust valves may be damaged

D

all of the above

相似考题

1.Which of the following reasons represents why the designed compression ratio of a gasoline engine is lower than that of a diesel engine?A.compression must be low for effective spark ignitionB.compression must be low for required horsepower and torque generationC.compression must be low to prevent pre-ignitionD.compression must be low to have effective pre-ignition

2.单选题As a heat engine,（） energy is the source of power by which the diesel engine can be operated.A electricB heatC mechanicalD exhaust

3.单选题The purpose of the compensating adjustment used in a diesel engine hydraulic governor is to （）A compensate for low oil levelB increase governor promptnessC prevent governor huntingD limit engine load

4.A diesel engine exposed to widely varying ambient temperatures should use to a lubricating oil with .A.a high viscosity indexB.a low viscosity indexC.neutralize acidsD.resist oxidation at high temperatures

更多“A diesel engine should not be operated at low loads for long”相关问题

  • 第1题：

    单选题
    An over-speed trip stops a diesel engine when the engine （）
    A

    runs out of fuel

    B

    has low lubricating oil pressure

    C

    exceeds a set maximum speed

    D

    has high cooling water temperature


    正确答案： B
    解析： 暂无解析

  • 第2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 air

    B

    increasing the lube oil pressure

    C

    heating the engine fuel supply

    D

    heating the engine coolant


    正确答案： A
    解析： 暂无解析

  • 第3题：

    单选题
    Which of the following procedures should be carried out when a large, low-speed, diesel engine is operated with one cylinder secured?（）
    A

    Lubrication to the defective cylinder should be increased

    B

    Cooling water temperature to the engine should be increased

    C

    Only the turbocharger speed should be reduced

    D

    Engine speed should be reduced


    正确答案： D
    解析： 暂无解析

  • 第4题：

    单选题
    Which of the listed diesel engine operating conditions should be checked immediately after any diesel engine is started?（）
    A

    Exhaust temperature

    B

    Lube oil level

    C

    Lube oil pressure

    D

    Water level in the expansion tank


    正确答案： C
    解析： 暂无解析

  • 第5题：

    单选题
    A diesel engine exposed to widely varying ambient temperatures should use to a lubricating oil with （）
    A

    a high viscosity index

    B

    a low viscosity index

    C

    neutralize acids

    D

    resist oxidation at high temperatures


    正确答案： D
    解析： 暂无解析

  • 第6题：

    单选题
    Burning fuel with a high sulfur content in a diesel engine will （）
    A

    increase thermal efficiency

    B

    cause clogging of the fuel system

    C

    increase the ability of the engine to start in cold weather

    D

    produce corrosion in the cylinder and exhaust system at low loads


    正确答案： A
    解析： 暂无解析

  • 第7题：

    单选题
    What harmful condition can result if a diesel engine is operated at very light loads for long periods of time?（）
    A

    increased carbon buildup

    B

    burning of intake valves

    C

    excessive firing pressures

    D

    increased fuel consumption


    正确答案： B
    解析： 暂无解析

  • 第8题：

    单选题
    A diesel engine may be hard to start if the （）
    A

    air intake is restricted

    B

    engine is cranked too fast

    C

    vibration dampener is faulty

    D

    exhaust back pressure is low


    正确答案： A
    解析： 暂无解析

  • 第9题：

    单选题
    If it becomes necessary to cutout an individual cylinder of a large, low-speed, main propulsion diesel engine, the fuel to that cylinder should be secured and its （）
    A

    fuel pump should be removed and all connections blanked off

    B

    cylinder oil feed rate should be increased slightly above that used at normal sea speed

    C

    cylinder oil feed rate should be reduced

    D

    cylinder oil feed rate should be increased to the maximum flow capable of the metering pump


    正确答案： B
    解析： 暂无解析

  • 第10题：

    单选题
    According to the relevant regulation, lifeboat should be powered by（）.
    A

    inboard diesel engine

    B

    outboard diesel engine

    C

    outboard gasoline engine

    D

    inboard gasoline engine


    正确答案： B
    解析： 暂无解析

  • 第11题：

    单选题
    When running a large, low-speed, main propulsion diesel engine on heavy fuel, which of the following precautions should be observed when switching back over to diesel oil?（）
    A

    The diesel oil must never be allowed to mix with the heavy fuel

    B

    The temperature of the fuel from the pre–heater should be gradually reduced after switching over the three–way valve

    C

    The heating steam to the pre-heater should be secured as soon as the diesel fuel passes through the three-way valve

    D

    The heating steam must be secured before the diesel oil passes through the three-way valve


    正确答案： D
    解析： 暂无解析

  • 第12题：

    单选题
    Misfiring in a diesel engine at light loads can be caused by（）
    A

    high lube oil temperature

    B

    low lube oil temperature

    C

    excessive cylinder cooling

    D

    high air injection pressure


    正确答案： D
    解析： 暂无解析

  • 第13题：

    单选题
    The diesel engine exhaust gas bypass, as fitted with some waste heat boilers, is installed to （）
    A

    prevent engine back pressure at heavy loads

    B

    increase total engine efficiency at low loads

    C

    prevent boiler corrosion at low engine loads

    D

    improve engine fuel consumption at any load


    正确答案： C
    解析： 暂无解析

  • 第14题：

    单选题
    The highest loads applied to the diesel engine crankshaft main bearings are （）
    A

    axial loads

    B

    firing loads

    C

    inertia loads

    D

    centripetal loads


    正确答案： C
    解析： 暂无解析

  • 第15题：

    单选题
    In order to start a large, low-speed, main propulsion diesel engine on high viscosity fuel after an extended shutdown, the （）
    A

    fuel must be preheated

    B

    intake air should be preheated

    C

    lube oil outlet temperature should be increased 20℃ above normal

    D

    none of the above


    正确答案： B
    解析： 暂无解析

  • 第16题：

    单选题
    Low compression of diesel engine may result from （）
    A

    a worn cylinder

    B

    broken piston rings

    C

    any of A and B

    D

    none of the above


    正确答案： A
    解析： 暂无解析

  • 第17题：

    单选题
    When the normal compression ratio of a diesel engine is not very high, misfiring at light loads may be caused by （）
    A

    overloading the engine

    B

    low exhaust valve lift

    C

    excessive cylinder cooling

    D

    insufficient mechanical clearance


    正确答案： A
    解析： 暂无解析

  • 第18题：

    单选题
    A diesel engine should not be operated at low loads for long periods of time because（）
    A

    heavy carbon deposits will buildup on the valves and in the exhaust

    B

    fuel dilution is increased at low load

    C

    exhaust valves may be damaged

    D

    all of the above


    正确答案： C
    解析： 暂无解析

  • 第19题：

    单选题
    Electrically operated safety devices on auxiliary diesel engines function to stop the engine by （）.
    A

    increasing the volume of intake air

    B

    shutting off the fuel supply

    C

    increasing the engine back pressure

    D

    over-speeding the engine


    正确答案： A
    解析： 暂无解析

  • 第20题：

    单选题
    Operating a diesel engine under light loads and at low temperatures for an exhaust for an extended period can result in（）
    A

    formation of carbon on the intake and exhaust ports

    B

    high water jacket temperatures

    C

    overheated pistons and cylinders

    D

    an increase in lube oil viscosity due to fuel dilution


    正确答案： D
    解析： 暂无解析

  • 第21题：

    单选题
    Which of the following reasons represents why the designed compression ratio of a gasoline engine is lower than that of a diesel engine?（）
    A

    compression must be low for effective spark ignition

    B

    compression must be low for required horsepower and torque generation

    C

    compression must be low to prevent pre-ignition

    D

    compression must be low to have effective pre-ignition


    正确答案： B
    解析： 暂无解析

  • 第22题：

    单选题
    Which is false about engine trials?（）
    A

    engine trails should be done after finishing the operation of turning the engine with the turning gear and starting the engine on air briefly

    B

    in the operation of engine trails, the main engine should be running in low-speed

    C

    As to the ship equipment with twin main engine, engine trials should be done with one engine ahead and another engine astern at the same time

    D

    the order “engine trials” should be given by the bridge


    正确答案： A
    解析： 暂无解析

  • 第23题：

    单选题
    When ship navigating in rough sea, the correct operation is （）
    A

    navigating with a low diesel engine speed

    B

    navigating with a stable diesel engine speed

    C

    increasing the efficiency of propeller

    D

    increasing fuel injection


    正确答案： D
    解析： 暂无解析

  • 第24题：

    单选题
    Which of the following conditions may need to be reduced when operating a large, low speed, main propulsion, diesel engine at low loads?（）
    A

    Injection pressures

    B

    Control air supply pressure

    C

    Cooling water flow through after-coolers

    D

    Lube oil temperature


    正确答案： D
    解析： 暂无解析

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