1、三管轮轮机英语大证考试真题41期三管轮轮机英语大证考试真题41期 中华人民共和国海事局 2021年第3期海船船员适任证书全国统考试题(总第41期) 科目：轮机英语试卷代号：805 适用对象：无限、近洋航区3000KW及以上船舶二/三管轮 （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74题，每题1分，第75题至78题，每题1.5分,第79题至80题, 每题10分。 一、单项选择题 1. A diesel engine is similar to a gasoline engine
2、 except that the former has no _. A. cross-head B. spark plug C. connecting rod D. cylinder 2. A diesel engine which is rated for normal operation at a crankshaft speed of 800 RPM, is commonly classed as a _. A. slow-speed diesel B. medium-speed diesel C. high-speed diesel D. constant-speed diesel 3
3、.Which of the diesel engine components listed increases air density and helps to improve engine operating efficiency? A. Impeller B. Compressor C. After-cooler D. Exhaust diffuser 4.For a given size engine, the two-stroke/cycle diesel engine will deliver more power than a four- stroke/cycle diesel e
4、ngine because _. A. it has a longer power stroke B. more air gets into the cylinder each stroke C. it develops twice as many power strokes at the same speed D. higher combustion pressure is developed 5.The intake valves in a diesel engine are reseated by _. A. cam followers B. push rods C. combustio
5、n gases D. valve springs 6.According to the way the energy of the exhaust gases is utilized, pressure-charging can be divided into two main systems, namely, the constant-pressure system and _. A. the pulse-phase system B. the pulse Doppler system C. the pulse system D. the pulse interval system 7.An
6、 over-speed safety device is usually fitted to a generator engine for_in the event of over- speed. A. cutting power off the engine B. increasing the fuel pump setting C. braking the crankshaft D. stabilizing the ship speed 8.What preventative maintenance should be done frequently to diesel engine st
7、arting air receivers? A. Drain the accumulated moisture. B. Test the relief valves. C. Watch the temperature to prevent fluctuations in pressure. D. Clean the interior to remove oil and foreign matter. 9.Immediately after any diesel engine is started, the engineer should check the _. A. crankcase pr
8、essure B. lube oil pressure C. seawater pressure D. exhaust temperature 10. A controllable pitch propeller on a diesel driven vessel eliminates the need for _. A. friction clutches B. disconnect clutches C. reversing gears D. reduction gears 11.In motor ship, _is often used to recover some of the he
9、at carried in the exhaust gases from the main engine. A. an diesel oil heater B. a waste heat boiler C. a fresh water generator D. a donkey boiler 12.An exhaust gas bypass is installed on a waste heat boiler in order to _. A. bypass exhaust gas at high loads to prevent excessive back pressure B. byp
10、ass a portion of the exhaust gas at peak loads for better efficiency C. recycle exhaust gas to the turbocharger D. minimize moisture condensation in the boiler gas passages at low loads 13.Prior to lighting off a cold automatically fired auxiliary boiler, you should _. A. check and regulate the wate
11、r level B. close the air cock once fires are lit C. blow down the gage glass D. assure protective steam flow 14.Flame failure in an automatically fired auxiliary boiler can mostly result from a/an _. A. incorrect electrode setting B. incorrect nozzle position C. clogged fuel nozzle D. broken high te
12、nsion lead 15.Waterside scale in a fire-tube boiler may cause _. A. increased heat transfer B. fireside erosion C. high steam demand D. overheated tubes 16.Which of the following will be the advantage of a centrifugal pump as compared with a reciprocating pump? I. Its discharge is continuous; II. It
13、 has no internal valves; III. Upon accidental closing of discharge valve, excessive pressure will not build up A. I, II B. II, III C. I, II, III D. II only 17.Why are removable sleeves installed on centrifugal pump shafts? A. They make it easier to replace the pump shaft packing. B. They can be econ
14、omically replaced as they wear out. C. They can be removed when it is necessary to lighten the weight of the pump. D. They increase the strength of the shaft. 18.If one of the bilge system manifold valves does not properly seat, the _. A. bilge well connected to that valve, plus the second bilge wel
15、l being pumped will be completely emptied B. bilge system will lose vacuum and prevent the other bilges from being pumped out C. bilge well aft connected to that valve will siphon(虹吸) its contents to the forward bilge wells D. discharge pressure will be too high. 19.Which of the listed statements is
16、 correct concerning the starting of centrifugal pumps? A. They should always be started with the discharge valve closed. B. They should always be started with the discharge valve opened. C. A priming pump is always required to flood the impeller suction. D. They should always be started with the sea
17、ling line valves closed. 20.The simplest method to use for determining if a centrifugal pump is operating as designed, is to _. A. closely observe the pump discharge temperature B. close off the discharge valve, and watch for a rise in pressure C. momentarily close off the suction valve, and watch f
18、or a rise in pressure D. use a clamp on ammeter and compare the readings to past records 21.Which of the following modes of heat transfer does NOT require any physical contact between a warmer and a cooler substance? A. Radiation B. Conduction C. Natural convection D. Contact directly 22. A re-heate
19、r in an air conditioning system functions to _. A. control inlet air temperature B. control inlet air volume C. maintain relative humidity at 15% D. restore conditioned air temperature to a comfortable level 23.In a chilled water air conditioning unit using a reciprocating compressor, the refrigerat
20、ing effect of the primary refrigerant can be increased by _. A. increasing refrigerant pressure in the coil B. increasing chilled water flow through the cooler C. sub-cooling the refrigerant in the condenser D. superheating the refrigerant in the compressor 24.Sludge may form in the lubricating oil
21、crankcase of a reciprocating air conditioning compressor as a result of _. A. wax precipitation in the lube oil B. contamination by dust, scale, or moisture C. refrigerant bubbles in the lube oil D. refrigerant reducing the lube oil viscosity 25.Placing a filter on the _of an oily water separator wi
22、ll “polish” the discharge but overloading must be avoided. A. suction side B. discharge side C. by-pass pipe D. sampling pipe 26.When started, a complete oily water separating unit is first filled _.The oily water mixture is then pumped through the inlet pipe into the coarse separating compartment.
23、A. with dirty water B. with clean water C. by oily water D. by mixed water 27.Which is the pollution prevention equipment? A. booster pump B. evaporator C. incinerator D. cooler 28.The _is used to burn oil sludge. A. clarifier B. oil/water separator C. incinerator D. distiller 29.Most marine biologi
24、cal sewage treatment plants consist of all the following statements except _. A. aeration tanks B. settling tanks C. disinfection agent （消毒剂） D. anaerobic bacteria (厌氧菌) 30.For a purifier changing to a gravity disc with smaller hole diameter will move the interface towards the _. A. bowl periphery B
25、. bowl center C. upper surface D. lower surface 31.The _of the gravity disc is too big. It cause oil to flow through the water outlet. We changed the disc and no oil is found in the water outlet. A. gravity B. diameter C. circumference D. cylinder 32.The advantages of flash type evaporators, as comp
26、ared to submerged tube type evaporators, include _. A. less internal corrosion because of lower brine density B. higher temperature evaporation for lower salinity of the distillate produced C. less scale formation in a flash evaporator D. less feed-water required for a flash evaporator 33.Distilled
27、water from an evaporator may be discharged into a drinking water tank _. A. through a detachable hose connection B. after passing through an activated charcoal filter C. after chemical analysis shows it is fit for consumption D. through a solenoid operated three-way valve 34.What type of valve is us
28、ed to direct the flow of hydraulic fluid? A. relief valve B. direction control valve C. stop valve D. pressure control valve 35.In a radial piston pump, reversal and control of fluid flow are accomplished by moving the _. A. central valve B. radial plunger C. floating ring D. cylinder body 36.In a g
29、eneral cargo crane, _is fitted to lift the cargo load. A. the slewing motor B. the luffing motor C. the hoisting motor D. the fan moter 37._are used to handle anchors and chains. A. Cargo winches B. Mooring winches C. Windlasses D. Cargo hatches 38.The clutch band of a constant tensioning mooring wi
30、nch must be set up tight enough to drive the winch drum and should slip only when _. A. excessive loads are placed on the winch B. minimum pull is being exerted by the winch C. automatic operation of the winch is desired D. wire is being retrieved at the maximum rate 39.Dual (双的)electro-hydraulic st
31、eering units usually operate _. A. with both pumps on line at the same time Bwith one pump on standby Cwith the follow-up gear disconnected Donly when the rudder is moved amidships 40.One factor that determines the frequency of an alternator is the _. A. number of turns of wire in the armature coil B. number of magnetic poles C. strength of the magnets used D. output voltage 41.
