单选题The starting air entering the cylinder begins when the piston()Ahas nearly come to the TDCBhas just past the TDCChas nearly come to the BDCDhas just past the BDC

单选题
The starting air entering the cylinder begins when the piston()
A

has nearly come to the TDC

B

has just past the TDC

C

has nearly come to the BDC

D

has just past the BDC


参考解析

解析: 暂无解析

相关考题:

第二组Under normal operation, some lubrication oil mist may be discharged from the air compressor to the air start system. This oil may be from excess compressor cylinder lubrication, from faulty oil scraper rings, or may even be suspended oil vapor contaminating the engine room atmosphere and drawn in at the compressor suction. Oil discharge is kept to a minimum by draining the after cooler, air receiver and starting system. If small quantities of lubrication oil do get passed into the starting air system, they will deposit as thin moist film over internal pipe surfaces but are not readily combustible. If a cylinder non-return valve leak while the engine is in operation, some hot gas, possibly with unburned fuel and cylinder lubrication oil, may be blown through the valve to the adjacent air manifold. With further heating from the leaky valve, this, together with the already deposited oil film, will carbonize and form. incandescent carbon. If starting air is applied to the system while still hot, the high pressure air coming into contact with the burning carbon may cause an explosion. Such an explosion will cause a flame to pass back through the air start pipe system, evaporating the deposited oil film and igniting it in the presence of air. Very high velocities and shockwaves are generated which may rupture pipes and fittings.Alternatively, if excessive oil has entered the air start system, a mixture of air and oil droplets may be discharged through the open cylinder non-return valve during starting. This spray may ignite due to high temperatures in the cylinder, causing a flame through the still open valve to the air manifold.To prevent an explosion, air start valves must be correctly maintained and lubricated to ensure correct timing and free movement with positive closing. Oil in the system must be kept to a minimum, pipe lines must be drained and cleaned internally when necessary and oil discharge from air compressors must be kept to a minimum by good maintenance.The passage is mainly aboutA.crankcase explosionB.scavenge box fireC.starting air pipeD.the danger of explosion in the starting air system

In an operating diesel engine, which of the following conditions is an indication of a leaking air starting valve?A.Noise coming from that air starting valveB.Continuous operation of the starting air compressorC.Zero air pressure in the air starting systemD.Overheated starting air pipe to the cylinder head

In the event of the cylinder starting valve leakage ______would pass into the air pipes and ignite the oil deposited.A.cooling waterB.vapor from the boilerC.starting airD.hot gases

______device is provided to prevent starting air from being admitted to the cylinder before the reversing is completed.A.An automaticB.A transmissionC.A self-regulatingD.An interlocking

单选题Vessels having main engines arranged for air starting are to be provided with at least ()Aone automatic drain serving both containersBtwo air starting containers of approximately equal sizeCone control air container and one starting air containerDone additional means of starting the main engine

单选题The opening or closing of the cylinder starting valve is controlled by ().Athe starting air distributorBthe cut-off valve on the air mainCthe main starting valveDthe air bottle control valve

单选题When the order () is received from the bridge, the main air stop valve in the starting air line should be shut.Astand-by engineBfull aheadCfinished with engineDfull away

单选题The main purpose of starting the diesel engine on air briefly is()Ato inspect if the cylinder has the water leakageBto expel out the residual water/gas/oil from the cylinderCto check if fuel supply is normalDA and B

单选题() device is provided to prevent starting air from being admitted to the cylinder before the reversing is completed.AAn automaticBA transmissionCA self-regulatingDAn interlocking

单选题When used in conjunction with a turbocharger, the main function of an after-cooler is to ()Aincrease the density of the cylinder air chargeBprevent turbocharger overheatingCliminate the need for a pre-coolerDremove moisture from air compressed by the turbocharger

单选题When an air started, four-stroke/cycle diesel engine is being cranked, the starting air is admitted to each cylinder during what would normally be the()Aintake strokeBcompression strokeCpower strokeDexhaust stroke

单选题Which of the following methods is used to prevent throttling of compressed air through the diesel engine air starting valves?()AHolding the valve open for a long periodBIncreasing the starting air pressure usedCOpening the stating air valve quicklyDReducing the starting air valve size

单选题Intercoolers installed on starting air compressors, reduce the possibility of()Adust entering the high pressure stageBlube oil carbonizationCdischarge pulsationsDinter-stage vapor lock

单选题When starting an engine, the compressed air enters the cylinder when the corresponding piston is in position of its()Asuction strokeBcompression strokeCpower strokeDexhaust stroke

单选题The compressed air is admitted to each cylinder through a cam operated by starting air valve when the piston has just passed its ().ABDCBTDCCBBDCDATDC

单选题In the starting system, the automatic valve is controlled by(), and the cylinder start valves are controlled by()Apilot air;pilot airBhandle;solenoidChandle;pilot air coming through the distributorDsolenoid;pilot air coming through the distributor

单选题Each cylinder has one starting valve which is usually opened by air pressure and closed by ()Anuts and boltsBnew jointsCspring forceDsealing rings

单选题Compressed air is supplied by air compression to ().Athe air receiversBthe starting valvesCthe cylinder coversDthe distributors

单选题In the event of the cylinder starting valve leakage () would pass into the air pipes and ignite the oil deposited.Acooling waterBvapor from the boilerCstarting airDhot gases

单选题The starting air entering the cylinder begins when the piston()Ahas nearly come to the TDCBhas just past the TDCChas nearly come to the BDCDhas just past the BDC

单选题If a four-stroke/cycle diesel engine is started by injecting air into the cylinder, the pistons receiving the charge of starting air must be()Aon the power strokeBon the exhaust strokeCat the end of the power strokeDat the start of the intake stroke

单选题When starting air is admitted, a diesel engine turns over very slowly without firingThe cause may be ()Aan obstruction in an cylinderBwater accumulation in some engine cylindersClow starting air pressureDlow scavenge air pressure

单选题When the starting air valve closes on one cylinder, another starting air valve has () opened on another cylinder whose piston has just commenced its downward stroke.AjustBnearlyCmerelyDalready

单选题In an operating diesel engine, which of the following condition is an indication of a leaking air starting valve?()Anoise coming from that air starting valveBcontinuous operation of the starting air compressorCzero air pressure in the air starting systemDoverheated starting air pipe to the cylinder head

单选题The air distributor is conventionally driven by() and distributes into each cylinder by() certain sequence.Acamshaft;fresh airBcamshaft;starting airCelectronic motor which is controlled by a computer;fresh airDelectronic motor which is controlled by a computer;starting air

单选题When an engine is starting and has got a sufficiently high speed, say about 20 rpm,()Athe starting air supply is cut off and fuel is injected into the cylindersBthe fuel feeding is cut off and the turning gear is put inCthe starting air supply is cut off and turning gear is taken outDthe electric blower is shut down and fuel is injected into the cylinders

单选题The highest pressure in a diesel engine cylinder normally occurs ().Aat TDCBbefore TDCCafter TDCDduring air starting

单选题In slow speed two-stroke engines,()the fresh air entering begins when and stops as()Athe inlet port is opened by the up coming piston; the port is closed by the down goingBthe inlet valve is opened by the down going piston;the inlet valve is closedCthe inlet port is opened by the down going piston;the port is closed by the up comingDthe inlet valve is opened