第47期轮机英语

47期轮机英语考试题目

一单项选择题

A1.The___ engine is used for alternators and some times for main propulsion provide a propeller of between

90 to 120 rpm.

A.four-stroke

B.two-stroke.

C.slow speed

D.reversible

B2.The abbreviation”MIP”stands for____,

A.middle indicating pressure

B.mean indicated pressure

C.mean pitch

D.middle indicated power

D3.The cetane number of a diesel fuel oil indicates its____.

A.viscosity

B.acid content

C.heating value

D.ignition quality

C4.In a two-stroke engine the camshaft rotates at___the enging rotational speed.

A.half

B.twice

C.the same speed as

D.four times

D5.A diesel enging is similar to a gasoline engine except that the former has no ____.

A.cross-head

B.cylinder

C.connecting rod

D.spark plug

C6.It is easier to replace a dry cylinder liner than a wet one because____.

A.of the thin wall thickedss

B.honing makes it easier to maintain the desired oil film

C.water seals are not required

D.it fits more loosely due to a decrease in heat transfer through the composite wall

D7.A main bearing consists of two shells which are secured by means of studs and____.

A.tie rods

B.though bolts

C.lead wires

D.bearing caps

C8.However fast or slow the combustion rate,it is still a____between carbon,hydrogen,sulph and oxygen that releases heat.

A.physical deformation

B.state exchange

C.chemical reaction

D.coalescence

A9.During the fuel injection period,fuel pressure must exceed cylinder gas pressure to____.

A.ensure penetration and distribution of the fuel in the combustion chamber

B.ensure the needle valves is flushed clean duringeach injection

C.prevent combustion gas blowback into the open needle valve

Dprevent reflected pressure waves when the neddle valve close.

B10.In a diesel engine lube oil system ,which of the following parts should be lubricated first?

A.Camshaft bearings

B.Main bearings

C.Piston crowns

D.Cylinder walls

B11.In a diesel engine closed freshwater cooling system,the amount of coolant flowing through the heat exchanger is controlled by the _____,

A.suction pressure regulator

B.thermostatic bypass valve

C.sea water temperature

D.water level in the expansion tank

C12.Which of diesel engine compnents listed increases air density and helps to improve engine operating efficiency?

A.Impeller

B.Air bottle

C.Air cooler

D.Exhaust diffuser

B13.A large two-stroke/cycle direct reversing diesel engine is to be revered. Prior to the admission of starting air you must_____.

A.line up the engine for restarting with diesel oil

B.reposition the fuel injection cam

C.change the intake and exhaust valve cam positions

D.place the starting cam in the intermediate position

C14.Which of the listed governer characteristics will greatly affect the load sharing relationship between paralleled diesel generators?

A.Sensitivity

B.Power

C.Speed droop

pensation

C15.Thermocouple pytometers are used on large,main propulsion diesel engines to indicate the temperature of the _____.

A.cooling water leaving each cylinder

B.fuel oil entering the injector

C.exhaust gases atvarious loactions

D.lube oil at the bearing supplies

B16.After starting a diesel engine,which of the listed oprating conditions should be checked first?

A.Air box pressure

B.Lube oil pressure

C.Exhaust temperatures

D.Raw water pressure

C17.To shut down a diesel engine after it exceeds the set maximum speed ,which type of device listed should be used?

A.Speed limiting governor

B.Over-speed governor

C.Over-speed trip

D.Over-speed relay

A18.The treatment of the fuel oils involves storage,heating,filtering and_____.

A.centrifuging

B.pressurizing

C.atomization

D.igniting

B19.A propeller,in order to operate efficiently,must rolate at a relatively_____ speed

A.high

B.low

C.fast

D.lowly

tcnt heat changes the___ of water.

A.physical-state

B.temperature

C.atmospheric-pressure

D.sensible-pressure

C21.The primary function of a flame safeguard system, as used on am automatically fired auxiliary boiler,is toprevent_____.

A.accidental dry firing and overpressure

B.uncontrolled fires in the furnace

C.explosions in the boiler furnace

D.overheating of the pressure parts

A22.Improper maintenance of the fule oil burners in an automatically fired auxiliary boiler could resuit in_______.

A.increased fule consumption

B.increased feed-water consumption

C.fule pump failure

bustion control systerm failure

A23.Bumer ignition failure in an automatically fired auxiliary boiler could result in_____.

A.a burned out solenoid in the oil supply valva

B.high tempersure excess air

C.incorrectly setting the hot-welldump valve

D.an incorrectly positioned burner smubber(缓冲器)relary