单选题Before being shut down, a diesel engine should idle a few minutes in orderto ()Aprevent governor surging at shutdownBmake sure the fuel nozzles are flushed cleanCprevent pressure buildup in the fuel linesDprevent damage from localized overheating
单选题
Before being shut down, a diesel engine should idle a few minutes in orderto ()
A
prevent governor surging at shutdown
B
make sure the fuel nozzles are flushed clean
C
prevent pressure buildup in the fuel lines
D
prevent damage from localized overheating
参考解析
解析:
暂无解析
相关考题:
You should make sure that your password is long enough to prevent it ______ being easily hacked. A.inB.fromC.out
The pressure differential across a diesel engine lube oil system duplex filter should be checked to ________.A.determine the need for filter cleaningB.measure any change in oil viscosityC.prevent damage to the filterD.determine the need for batch filtration
A thrust bearing is used with a propulsion diesel engine to ____.A.control axial movement of the crankshaftB.transmit engine thrust to the propeller shaftC.absorb vibrations in the propeller shaftingD.prevent propeller thrust from being transmitted to the hull
第一组Older loop scavenged engines may have a single injector mounted centrally in the cylinder head. Because the exhaust valve is in the center of the cylinder head on modern uniflow scavenged engines the fuel valves (2 or 3) are arranged around the periphery of the head. The pressure at which the injector operates can be adjusted by adjusting the loading on the spring. The pressures at which the injectors operate vary depending on the engine, but can be as high as 540 bar. Some injectors have internal cooling passages in them extending into the nozzle through which cooling water is circulated. This is to prevent overheating and burning of the nozzle tip. Injectors on modern engines do not have internal cooling passages. They are cooled by a combination of the intensive bore cooling in the cylinder head being close to the valve pockets and by the fuel which is re-circulated through the injector when the follower is on the base of the cam or when the engine is stopped. As well as cooling the injector, re-circulating the fuel when the engine is stopped keeps the fuel at the correct viscosity for injection by preventing it from cooling down. Fuel injectors must be kept in good condition to maintain optimum efficiency, and to prevent conditions arising which could lead to damage within the cylinder. Injectors should be changed in line with manufacturers recommendations, overhauled and tested. Springs can weaken with repeated operation leading to the injector opening at a lower pressure than designed. The needle valve and seat can wear which together with worn nozzle holes will lead to incorrect atomization and dribbling.Modern uniflow scavenged engines have______.A.a single injector mounted in the center of the cylinder headB.several injectors mounted around the external boundary of the cylinder headC.a single injector mounted at the external boundary of the cylinder headD.several injectors mounted in the center of the cylinder head
_______can be a direct cause of faulty operation of diesel engine fuel injection nozzles.A.Excessive fuel nozzle holder coolingB.Sediment in the fuel supplyC.Distortion of the fuel spray patternD.Improper atomization of the fuel
Why is it necessary to warn engine room personnel before activating the fixed CO2 system?A.To make them aware there is a fireB.To let them know they should leave the engine roomC.To prevent possible injury from frostbiteD.To make them aware that ventilation will automatically stop
A safe fuel system must ______.A.prevent engine overheatingB.have proper air/gasoline fuel mixture ratioC.be liquid- and vapor-tightD.supply sufficient air to the intake manifold
单选题Water in the fuel can prevent the engine from starting, prevent it from developing full power, or ()Arun at an irregular speedBcreate high lube oil temperatureCcause the engine to over-speedDcause blue smoke in the exhaust
单选题Care and cleanliness are required when installing diesel fuel filters ().Ato prevent the fuel system from becoming air-houndBto prevent the fuel system becoming clogged with dirty particlesCboth of the aboveDto prevent the lubricating oil from leaking out of the filter element
单选题Heat damage to fuel injection nozzles can be prevented by avoiding ()Aexcessive fuel oil temperatureBlong periods of engine overloadCmetallic contact between nozzles and cylinder headsDhard carbon deposit and varnish on the nozzles
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?()ATo prevent internal damage form local overheatingBTo ensure the fuel nozzles are flushed cleanCTo clear the smoke stackDTo let the waste heat boiler reduce its rate of steam generation
单选题Before starting a diesel engine, you should always()Acheck the pyrometer readingsBcheck the crankcase oil levelCcheck the fuel oil strainersDclean the fuel system
单选题While a ship with twin screw is making a turn, in order to prevent overload, the duty engineer should ()Areduce the fuel feeding of main engine of inner propellerBreduce the fuel feeding of main engine of outer propellerCfirstly reduce the fuel of main engine of inner propeller, then reduce the fuel feeding of engine of outer propellerDreduce fuel feeding of two engines at the same time
单选题If a tow-stroke/diesel engine is over-speeding due to leakage of lube oil into the cylinders, what should you do to stop the engine?()AMove the fuel control mechanism to the no fuel positionBBlock the fuel supply by closing the master fuel valveCShut off the fuel supply and block the flow of intake airDRelieve all pressure in the fuel system
单选题Why is it necessary to warn engine room personnel before activating the fixed CO2 system?()ATo make them aware there is a fireBTo let them know they should leave the engine roomCTo prevent possible injury from frostbiteDTo make them aware that ventilation will automatically stop
单选题The lubrication to the cylinders affected by the fire must be ()to prevent seizure and all scavenge drains must be ()to prevent the discharge of sparks and burning oil from the drains into the engine room.Adecreased;openedBdecreased;shutCincreased;openedDincreased;shut
单选题After fuel tanks have been topped off, which of the listed procedures should be followed next?()AThe pressure-vacuum relief valve should be resetBThe tanks should be made seaworthy to prevent contaminationCThe tanks should be sounded to make sure the levels are not risingDThe tanks should be marked with a bull stamp on the manifold filling valve
单选题If a diesel engine has been stopped because of piston seizure due to severe overheating, the crankcase()Ainspection covers should not be opened until the engine has cooledBventilation system should be continued in operation for one hour for coolingCscavenge pump should be immediately secured to prevent loss of lube oilDexplosion covers should be opened slightly to provide extra ventilation
单选题Fuel is admitted to a diesel engine cylinder through the ().Aintake valvesBcarburetorCexhaust portsDinjector nozzles
单选题Faulty operation of diesel engine fuel injection nozzles can be directly caused by ().Awater in the fuel oil supplyBexcessive fuel nozzle holder coolingCa distorted fuel spray patternDleakage past the plunger into the oil drain
单选题When fueling has been completed().Athe fuel tank fill pipe should be left open to allow vapors to vent from the tankBthe engine should be started immediately to prevent vapor lock in the fuel lineCall hatches should be opened and all compartments should be ventilatedDopen the fuel line and drain a small amount of gasoline into the bilge to clear the line of sediment
单选题Faulty operation of diesel engine fuel injection nozzles can be a direct cause of().Aexcessive fuel nozzle holder coolingBsediment in the fuel supplyCdistortion of the fuel spray patternDimproper atomization of the fuel
单选题Before being shut down, a diesel engine should idle a few minutes in orderto ()Aprevent governor surging at shutdownBmake sure the fuel nozzles are flushed cleanCprevent pressure buildup in the fuel linesDprevent damage from localized overheating
单选题When ship navigating in rough sea, the first measure taken by the chief engineer to prevent the overload should be()Acleaning fuel oil, lubricating oil and seawater filterBreducing fuel feeding of the main engine appropriately or reducing the pitch angle of propellerCusing low sea chestDclosing the skylight and the ventilation opening, which doesn’t affect the normal work of equipments
单选题Heat damage to fuel injection nozzles on small high-speed diesel engines, can be prevented by()Aemploying fuel oil as a cooling mediumBpreventing hard carbon deposit on nozzle tipsCavoiding fuel oil temperature exceeding builder’s specificationDensuring good metallic contact between nozzles and cylinder heads
单选题Whether a ship is sailing before the wind or sailing in the rough sea, we must reduce the fuel injection of the main engine.For the former one, it aims to prevent the main engine being(), while for the later one, it aims to prevent the main engine being().Aoverspeed;overloadBoverload;overspeedCover torque;overspeedDlow mechanical efficiency;overload
单选题To prevent vibration damage to the fuel supply line of a diesel engine, you may use ().Aa short length of heavy duty clear plastic tubingBa length of approved flexible nonmetallic hoseCwelded flange connections for all jointsDaluminum piping with expansion loops
单选题Air in the fuel lines to the fuel injection nozzles of a diesel engine will cause the engine to ()Aburn excessive amounts of lube oilBoverheat without smokingCoperate with reduce power or stopDrun away without load