大管轮轮机英语综合(33-48期)(13)

If the head pressure of a reciprocating refrigeration compressor is excessive, ______. A. the relief valve should open before the high pressure cutout

B. the relief valve should open and allow the excess refrigerant to flow to the receiver C. the high pressure cutout switch should operate before the relief valve opens D. you should close the suction valve

33. Sludge may form in the crankcase of an air conditioning compressor as a result of ______. A. bubbling refrigerant B. overheating and oxidation

C. lowered operating temperatures D. reducing the cloud or flash point 34. A feeler or thermal bulb is used for the expansion valve to ______. A. detect the temperature B. detect the pressure

C. heat the refrigerant D. accelerate the refrigerant

35.

The dew point of air is reached when the wet bulb temperature is ______.

A. twice the dry bulb temperature B. 10℃ above the dry bulb temperature C. 5℃ above the dry bulb temperature D. equal to the dry bulb temperature 36. ______ is used to produce electric power.

A. An alternator B. A fresh water generator C. A compressor D. A clarifier 37. In order to change the direction of rotation of a D.C. motor ______.

I. the field leads must be changed ; II. the input leads must be changed A. I only B. II only C. either I or II D. neither I or II

38.

Which of the following should be the FIRST step in removing a generator from parallel operation? A. Trip the generator off the switchboard.

大管轮轮机英语综合

B. Turn off all electrical equipment.

C. Remove the load from the 'off going' generator.

D. Increase the cycles of the generator staying on the line.

39. There is a danger of the starting current ______that the windings are burnt out. A. to increase B. to be so increased C. increased D. being so increased

40. The viscosity regulator controls the fuel oil temperature ______ provide oil at the correct viscosity for combustion.

A. in order that B. because of C. in order to D. owing to

41. When there is a fire in a large electric motor, normally the very FIRST step is to ______. A. secure the electric supply B. ventilate area to remove smoke C. start the fire pump and lead out hose D. apply foam

42. Engine protection by means of an alarm or shutdown control can be obtained with devices that are sensitive to ______.

A. temperature B. pressure C. engine speed D. all of the above

43. With UMS, when the engine room is unwatched ______will control the main engine. A. the bridge officer on watch B. the chief engineer C. the duty engineer D. the duty motorman

44. The correct tightening is obtained by use of ______to measure the extension given to the bolts. A. pressure gauges B. stretch gauges C. thermometers D. bridge gauges 45. A main propulsion diesel engine is normally shut down by ______. A. shutting off the air supply B. over-speeding the engine C. securing the fuel supply D. securing the ignition system

46.

One cylinder of a diesel engine is persistently knocking and does not cease when the fuel supply to that cylinder is secured. Which of the following problems may be the cause? A. Low loading of the cylinder. B. Excessive cooling of that piston.

C. Sluggish ring action on the piston. D. A mechanical defect in a working part. 47. Poor combustion in a diesel engine can be caused by ______________. A. reduce the engine load B. increase the cooling water flow C. increase the lube oil pressure D. adjust the fuel rack

48.

If fuel injection to a four-stroke/cycle diesel engine begins earlier than designed, ignition may be delayed because the ______.

A. cylinder compression pressure may not be high enough B. cylinder compression temperature may be too high C. fuel oil injection pressure may not be high enough D. scavenge and purge process is incomplete

49.

Diesel engine automated control systems may utilize sensing devices of dual function, with sensing ranges providing both alarm and engine shut down capability. Which of the key points listed would only require an alarm sensor?

A. Lube oil pressure and temperature. B. Jacket water pressure and temperature. C. Engine over-speed. D. Lube oil sump level. 50. Fix the fuel injector into ______after repair.

A. the cylinder liner B. the cylinder cover C. the cylinder jacket D. the piston 51.

Lower suction pressure of a pump may be caused by ______.

A. too much air in the pipe line B. closed inlet valve C. empty tank D. leaky pipe

52. Diesel engine exhaust temperatures may be used to indicate ______.

A. leaking exhaust valves B. an overloaded cylinder C. a clogged injector nozzle D. all of the above

53. Shims of different thicknesses are inserted between the shells to enable adjustment of ______.

A. the bearing clearances B. the bearing thickness C. the bearing strength D. the bridge hardness

54. Oil mist detectors are usually used on board to detect oil mist density within ______.

A. the engine crankcase B. the engine scavenge boxes C. drain tanks D. fuel tanks 55. Tools with ______handles should be used to check electric circuit.

A. plastic B. metal C. stainless steel D. copper

56. It is well known that the whole power distribution of the ship’s electrical services mainly

depend on the ______.

A. sub-boards B. main switchb …… 此处隐藏：5104字，全部文档内容请下载后查看。喜欢就下载吧 ……