轮机大管轮英语真题48期

)

科目：轮机英语

试卷代号：

803

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< /p>

82

题，每题

1

分，第

83

题至

94

< br>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 medium-speed

diesel engines is .

A. they operate between 150 and 450 rpm

B. they are connected to the propeller by gearing

C. their smaller size and weight

D. they can be connected directly to the propeller without gearing

2. The closing of the exhaust valves used on a modern, large, low-speed, main propulsion diesel

engine may be directly provided by .

A. large conical springs

B. compressed air pressure

C. hydraulic pressure D. exhaust gas pressure

3. One of the factors limiting the amount of toad which can be put on a modem marine diesel engine is

the .

A. governor sensitivity

B. exhaust temperature

C. fuel injection pressure D. speed of the cam shaft

4. The desirable properties or a marine fuel oil should inc

lude .

A. high flash point and high viscosity B. low flash point and high viscosity

C. low heating value and high sulphur content

D. high heating value and low sulphur content

5. As the plunger moves upwards in the barrel, injection will commence once the plunger bas

the spill ports and the pressure builds up.

A. opened up

B. closed off

C. lined up D. taken off

6.

In an auxiliary diesel engine bypass type lubricating oil system, the main lube oil pump forces

.

A. all of the oil used by the engine through a filter

B. some of the oil used by the engine through a filter

C. some of the oil used by the engine through a centrifuge

D. all of the oil used by the engine through a centrifuge

7. Because the circulating water is in a closed loop, is installed to cater for expansion and

contraction of the water at different conditions of operation.

A. an expansion joint B. a drain tank

C. a head tank

D. a contraction tank

8. The high air velocity leaving the compressor of an exhaust gas turbocharger is converted to pressure

in the .

A. inlet nozzle ring B. turbine wheel blade

C. diffuser passages

D. inlet volute

9. is usually driven by the engine camshaft and supplies pilot air to the cylinder air start valve.

A. An air receiver B. An operating valve C. An automatic valve

D. An air distributor

10. Diesel engines driving alternators operating in parallel must maintain a set frequency regardless of

load changes. The governor characteristic used to accomplish this is known as .

A. actuation B. sensitivity

C. compensation

D. promptness

11. By comparing the exhaust gas temperature of each cylinder, the operator can determine if the load

is balanced throughout the engine. The device most commonly used is a .

A. tachometer

B. pyrometer

C. dynamometer D. calorimeter

12. When the ship is going to enter into the harbor, ____.

A. change from heavy fuel oil to diesel oil for main engine

B. pumping out bilge water

C. change sea chest from high level one to lower level one

D. test emergency generator

13. If the jacket water temperature rises rapidly above normal in a diesel engine, you should first .

A. place standby cooler in operation

B. reduce engine toad

C. check thermostatic valve D. clean sea water strainer

14. Air cocks, usually positioned at the in a circulating system, is used to get rid of the air in the

system.

A. bending joint B. expansion tank C. weld

D. the highest point

15. Which of the following conditions could contribute to the cracking of a diesel engine cylinder head?

A. Leaking seal ring

B. Insufficient heat transfer from the exhaust valves

C. Blocked cooling water passages to the head

D. Excessive scavenging air provided to the engine

16. of an engine crankshaft can be detected by measuring deflections of' crank webs for each unit

of the engine.

A. Misalignment

B. Length C. Strength D. Stresses

17. can be a direct cause of faulty operation of diesel engine fuel injection nozzles.

A. Excessive fuel nozzle holder cooling

B. Sediment in the fuel supply

C. Distortion of the fuel spray pattern D. Improper atomization of the fuel

18. When fuel is injected late into a diesel engine cylinder .

A. the exhaust will be clear B. fuel consumption will be low

C. all the fuel will be burned at top dead center

D. fuel consumption will be high

19. A large change in ambient temperature, or using an oil of a viscosity different than the one

recommended by the manufacturer in a mechanical hydraulic governor, will result m the need to adjust

the .

A. pilot valve opening

B. compensating needle valve

C. compensating spring tension D. accumulator spring tension

20. Which of the following factors tends to increase scale formation on the saltwater side of a heat

exchanger used in a diesel engine cooling water system?

A. Baffle plates that have been bent during prior removal.

B. Leaks m the cooler tube nest.

C. Operating the engine while maintaining a high sea water outlet temperature.

D. A punctured sea water strainer supplying cooling water to the heat exchanger.

21. If the scavenge fire is of a more major nature, if there is a risk of the fire extending or if the

scavenge trunk is adjacent to the crankcase with risk of a hot spot developing it sometimes becomes

necessary to the engine.

A. stop

B. start C. speed up D. slow down

22. In an operating diesel engine, which of the following conditions is an indication of a leaking air

starting valve?

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A. Noise coming from that air starting valve.

B. Continuous operation of the starting air compressor.

C. Zero air pressure in the air starting system.

D. Overheated starting air pipe to the cylinder head.

23. Engine operating conditions may be indicated by the color of the exhaust smoke. Black smoke

could indicate .

A. an insufficient speed droop setting

B. an overloaded engine

C. clogged drain holes in the oil control rings D. complete combustion

24. In reducing engine speed to an efficient propeller speed by the use of reduction gears, ..

A. speed and torque are both reduced

B. speed is reduced and torque remains unchanged

C. speed is reduced and torque is increased

D. speed is sometimes unchanged while torque is increased

25. Which of the following statements represents an advantage of an electromagnetic clutch?

A. Large misalignments can be tolerated between the shaft and engine coupling

B. Slip is held to a minimum when reversing shaft rotation

C. Engine torsional vibrations to the driven shaft are eliminated

D. It aids in maintaining power factor

26. _____ of the controllable pitch propeller enables the blades to be moved to change the pitch angle.

A. An external mechanism

B. An internal mechanism

C. An interlock device D. A hunting gear system

27. When sailing ill cold zones, should be drained of water.

A. the ventilation pipe

B. the water line for fire fighting on the deck

C. the fuel oil line D. the water supplying line in bath room

28. If anything abnormal be found on the load change of main engine when the ship is entering in

shallow waterway, before taking measures the engineer on duty should .

A. stop main engine immediately

B. ask the captain and the chief engineer's permission for stopping the engine

C. inquire the bridge for the situation initiatively

D. stop engine and inform bridge

29. Pitted reduction gear teeth having a deep blue color with evidence of overheating have been

operated with .

A. excessive speed B. improper warm-up

C. extreme misalignment

D. inadequate lubrication

30. 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

31. To add refrigerant to the low side of an air conditioning system, the refrigerant should be

introduced through the .

A. suction service valve as a vapor

B. suction service valve as a liquid

C. discharge service valve as a vapor D. charging valve as a liquid

32.

If the superheat value of a thermostatic expansion valve is set too low, the _.

A. the suction line will be abnormally cold and liquid may slug back to the compressor

B. the suction line will be hot due to a reduced amount of refrigerant returning to the compressor

C. the temperature of the refrigerant within the condenser will remain the same

D. the temperature of the refrigerant passing through the sub-cooler will decrease

33. Sweating of the refrigeration system compressor crankcase is caused by .

A. too much superheat

B. insufficient superheat

C. suction pressure too low

D. excessive refrigerant returning to the compressor

34. If a refrigeration compressor is short cycling on high head pressure, you should .

A. purge the condenser if the waterside is dirty

B. check for proper water flow through the condenser

C. increase the high pressure cutout setting

D. reduce the cooling water flow

35. Which of the following problems could cause the high pressure cutout switch to shut down the

compressor in a refrigeration system?

A. A shortage of liquid refrigerant. B. Excessive frost on the evaporator.

C. Excessive condenser cooling water.

D. Insufficient condenser cooling water flow.

36. For a purifier changing to a gravity disc with smaller hole diameter will move the interface towards

the .

A. bowl periphery

B. bowl center

C. upper surface D. lower surface

37. can cause oil flow from water outlet of the oil purifier.

A. Oil inlet valve opening too quickly

B. Oil temperature little higher than normal

C. Diameter of gravity disc too small D. Viscosity of oil little lower than normal

38. Check valve isn't used to control .

A. direction of oil flow B. back pressure of return oil

C. bypass of filter

D. high pressure overflow

39. Among the basic categories of equipment, which of the following are used to convert the hydraulic

energy into linear motion?

A. hydraulic pumps B. valves

C. hydraulic cylinders

D. hydraulic motors

40. With reference to a two-ram actuating mechanism, which one of the following statement is FALSE?

A. The rams work inside cylinders.

B. The cylinders have glands sealing their open ends.

C. The rams are connected to a cross-head.

D. The cross-head is mounted on the rudder stock.

41. If a heavy sea strikes the rudder, the shock is transmitted through ___ to the rams, this cause a

sudden increase in oil pressure in one of the cylinders.

A. the control rod B. the hunting gear C. the floating ring

D. the tiller arm

42. The viscosity of' an oil is a measure of its .

A. weight

B. internal friction

C. demulsibility D.S.A.E. number

43. One function provided by a hydraulic accumulator is to ___.

A. provide an area where air can separate from the oil

B. provide an area to separate solid contaminants from the oil

C. act as an oil and water separator

D. absorb shocks occurring in the system

44. Which of the following components are used to convert alternating current produced in the

generator windings to direct current?

A. Armature and equalizer

B. Commutator and brushes

C. Rotor and interpoles D. Field and exciter

45. The frequency of an alternator at a given r/min is determined by the .

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试卷

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