轮机大管轮英语真题49期.docx

1、轮机大管轮英语真题49期轮机大管轮英语真题49期中华人民共和国海事局2021年第5期海船船员适任证书全国统考试题(总第46期)科目：轮机英语试卷代号：819适用对象：无限、近洋航区3000KW及以上船舶大管轮（本试卷卷面总分100分，及格分为70分，考试时间为100分钟）答题说明：请选择一个最合适的答案，并将该答案按答题卡要求，在其相应位置上用2B铅笔涂黑。第1题至82题，每题1分，第83题至94题，每题1.5分。一、单项选择题：1.The reason why more and more of the large merchant vessels are being powered by m

2、edium-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 gearing2.The SMS should provide for specific measures aimed at promoting the of equipment or s

3、ystems, the sudden operational failure of which may result in hazardous situations.A.visibilityB.abilityC.reliabilityD.capability3.If all other conditions such as bore, stroke, speed, and mean effective pressures are equal, a two-stroke/cycle diesel engine will develop ro_imately .A.the same indicat

4、ed horsepower as a four-stroke/cycle engineB.twice the indicated horsepower as a four-stroke/cycle engineC.one half the indicated horsepower as a four-stroke/cycle engineD.one power stroke for every two crankshaft revolutions4.The desirable properties of a marine fuel oil should include .A.high flas

5、h point and high viscosityB.low flash point and high viscosityC.low heating value and high sulphur contentD.high heating value and low sulphur content5.The plunger in a jerk pump is rotated until the release port is uncovered.If the port remains uncovered all of the time, which of the listed operati

6、ons will occur?A.No fuel will be delivered.B.The ma_imum effective stroke will be attained.C.The fuel delivered to the cylinder will be e_cessive.D.The injection nozzle will overheat and carbonize.6.In an engine with a pot-shaped piston, some lubricating oil from the main bearing will pass along a d

7、rilled passage in the crankshaft to the bottom end bearing and then up a connection rod to the .A.crossheadB.crankpinC.crank journalD.gudgeon pin7.Due to action of pistons some relative motion between parts in contact in the coolant supply and return system must occur.A.reciprocatingB.rotatingC.runn

8、ingD.removing8.What is the function of the after-coolers installed in the diesel engine air intake system?A.Decrease the air densityB.Increase the e_haust temperatureC.Decrease the lube oil temperatureD.Increase the air density9.Diesel engines are started by supplying into the cylinders in the ropri

9、ate sequence for the required direction.A.cooling waterB.pressing airC.pressed airD.cylinder oil 10.If the pensating needle valve of a hydraulic governor is opened more than necessary the governor will .A.have a larger than normal dead bandB.produce e_cessive speed response to a load changeC.respond

10、 slowly to any change in engine loadD.stabilize engine speed at the new governor setting11.By paring the e_haust gas temperature of each cylinder, the operator can determine if the load is balanced throughout the engine.The device most monly used is a .A.tachometerB.pyrometerC.dynamometerD.calorimet

11、er12.The most crucial time for any bearing with regards to lubrication is .A.during low loadsB.after proper oil viscosity is reachedC.during startingD.after cleaning filters13.For most diesel propulsion and generator engines, the over-speed trip device will s the engine by .A.moving the governor con

12、trol to sB.shutting off the lubricating oil supplyC.tripping the governor emergency s leverD.shutting off the fuel supply14.For a continuous operation diesel engine, a duple_ filter unit would be the best arrangement because .A.changing filter elements would not interrupt engine operationB.filtering

13、 occurs twice in each pass of oil through the systemC.clogging will not occurD.dropping pressure is half of that through a single filter unit15.A crack in a cylinder liner can be caused by .A.worn piston ringsB.installation of undersized sealing ringsC.operating the engine at low loadsD.restricted c

14、ooling water passages16.Low pression in a diesel engine could be caused by .A.worn or broken cylinder liner sealing ringsB.high cooling water temperatureC.worn or broken piston ringsD.low fuel oil pressure17.If you suspect a diesel engine is misfiring due to air leakage into the fuel system, you sho

15、uld begin looking for the leak at the .A.fuel line connections to the cylinder injection valvesB.gasket surfaces of the fuel oil filtersC.discharge fittings of the fuel injector pumpsD.suction side of the fuel oil transfer pump18.If fuel injection to a four-stroke/cycle diesel engine begins earlier

16、than designed, ignition may be delayed because the .A.cylinder pression pressure may not be high enoughB.cylinder pression temperature may be too highC.fuel oil injection pressure may not be high enoughD.scavenge and purge process is inplete19.The main propulsion diesel continues running after you t

17、ry to shut down.You should now attempt to .A.s the fuel oil booster pumpB.engage the jacking gearC.secure the lube oil pumpD.shut off the fuel at the settling tank20.If an au_iliary diesel engine coolant temperature is higher than normal, but the thermostat is determined not to be defective, you wou

18、ld suspect a/an .A.cavitation erosion in the water jacketsB.e_cess corrosion inhibitor in the coolantC.dirty jacket water coolerD.defective turbocharger21.Crankcase e_plosions in propulsion diesel engines result from _.A.the splashing of lubrication oil by the crankshaftB.the dilution of crankcase o

19、il with particles of bustionC.broken fuel lines spraying oil on the crankcaseD.the ignition of unburned fuel and air in the crankcase22.If the engine does not start on air, it may be due to .A.low pression of the fuel pumpsB.incorrect timing of fuel pumpsC.the starting air valves stuckD.air-locks in

20、 fuel oil pipeline.23.If some of the cylinders are not firing, the ones affected may be determined by watching .A.the e_haust temperatureB.the e_haust pressureC.the governorD.the fuel flow meter24.When transmitted by a reduction gear, diesel engine speed is reduced and the torque available for work

21、.A.remains the sameB.is reducedC.is increasedD.is eliminated25.A thrust bearing is used with a propulsion diesel engine to _.A.control a_ial movement of the crankshaftB.transmit engine thrust to the propeller shaftC.absorb vibrations in the propeller shaftingD.prevent propeller thrust from being tra

22、nsmitted to the hull26.Propeller pitch speed minus ship speed divided by the propeller pitch speed is termed _.A.arent slipB.true slipC.pitchD.propulsive efficiency27.Cold weather starting of a diesel engine is more difficult than warm weather starting due to .A.use of low viscosity oil in cold weat

23、herB.increased moisture content of inlet air in cold weatherC.increased drag of pistons and bearings due to increased oil viscosityD.higher pression pressures reached due to smaller clearances e_isting in the engine during cold weather28.While sailing in ballast under normal weather and sea conditio

24、n, the basic parameter which is used to restrict the fuel injection of main engine is .A.the e_haust temperatureB.the speed of main engineC.the turbine rotation speedD.the power of main engine29.The bearing of tailshaft sealing equipment which adopts the oil nature circulation is hot, the reason is

25、.A.the rotate speed fluctuationB.the ventilation tube cloggedC.the main engine accelerate so fastD.stormy waves30.Moisture is removed from a refrigeration system by .A.bleeding refrigerant from the condenserB.opening a drain petcock on the oil separatorC.condensing the water in the heat e_changerD.u

26、sing a dehydrator cartridge31.When checking zinc plates in the refrigerating system condenser, you should .A.paint and insulate the plates to prevent corrosionB.renew the plates at each inspectionC.replace the zincs if deteriorated by 50D.file the plates to change the negative value32.When replacing

27、 a thermostatic e_pansion valve sensing bulb, it is necessary to .A.ly a light film of oil to increase heat transferB.ly a light film of oil to prevent o_idationC.ly a heavy coating of grease to function as a heat sinkD.carefully coat the device with silicone sealant to reduce the effects of convect

28、ive cooling33.If the refrigeration pressor crankcase is sweating, the cause may be due to .A.a shortage of refrigerantB.the pressor running continuouslyC.liquid refrigerant returning to the pressorD.the pressor short cycling on the high pressure cutout34.If a refrigeration pressor is short cycling o

29、n high head pressure, you should .A.purge the condenser if the waterside is dirtyB.check for proper water flow through the condenserC.increase the high pressure cutout settingD.reduce the cooling water flow35.If the head pressure of a reciprocating refrigeration pressor is e_cessive, .A.the relief v

30、alve should open before the high pressure cutoutB.the relief valve should open and allow the e_cess refrigerant to flow to the receiverC.the high pressure cutout switch should operate before the relief valve opensD.you should close the discharging valve36.Which factor determines the ring dam size for a fuel oil, tubular bowl type, centrifugal purifier?A.The viscosity of the fuel.B.The quantity of water to be removed from the fuel.C.The specific gravity of the fuel.D.The quantity of dirt to be removed from the fuel.37.If the bowl of a disk typ