大管轮轮机英语综合
30. Which of the following problems could cause air to blow out through the inlet air filter of a
running compressor?
A. Excessive compression in the cylinder B. A broken intake valve
C. A dirty inlet filter element D. An improperly adjusted discharge valve
31. When a refrigeration compressor is in the 'off' cycle, the thermal expansion valve will ______.
A. always be wide open when the compressor restarts B. continue to operate as if the system were in operation
C. remain open until evaporator pressure equalizes, then close until the compressor restarts D. always be completely closed until the compressor restarts
32. An increasing head pressure in a refrigeration system, without any corresponding change in the
cooling water inlet temperature, would probably be caused by ______. A. restriction in refrigerant piping
B. air and non-condensable gases in the condenser C. water in the refrigerant
D. flooding back of liquid refrigerant from the evaporator
33. In a refrigeration system, if the cooling water to the condenser fails, the ______.
A. box temperature solenoid valve will close B. expansion valve will close C. compressor will shutdown D. king valve will open
34. The basic training in fire prevention and fire fighting should include the theoretical elements
which should cover ______.
A. the three elements of fire and explosion B. lower and upper flammable limits
C. classification of fires and applicable extinguishing agents D. all of the above
35. Sacrificial zinc anodes are used on the saltwater side of diesel engine heat exchangers to ______.
A. reduce electrolytic action on heat exchanger metals B. keep heat transfer surfaces shiny and clean C. prevent rapid accumulation of marine growth
D. provide a protective coating on heat exchanger surfaces
36. To parallel an incoming machine to a running machine therefore it is necessary to ensure firstly
that ______.
A. two frequencies must be brought into phase
B. the incoming machine accepts a small amount of load C. the running machine must be unload D. both voltages are equal
37. Self-excited a.c. generator with error operated voltage control systems draw the full excitation
power for the machine terminals. This dispenses with the current transformers, reactors and capacitors necessary for accurate compounding, but renders the excitation system vulnerable to variations in its output voltage. Which of the following is correct about the generator mentioned according to the sentences above?
A. It consumes no excitation power. B. It has current transformers.
C. Components are needed for accurate compounding. D. Its excitation system is vulnerable to voltage variations
38. Which of the following should be the FIRST step in removing a generator from parallel operation?
A. Trip the generator off the switchboard. 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. This arrangement is ______if the elements are directly connected to one another and the control
action takes place without human involvement.
A. a manual closed loop B. a manual opened loop C. an automatic closed loop D. an automatic opened loop
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. ______is a precaution which contributes to avoiding trouble under normal operating conditions.
A. Constant inspection B. Keeping constant load C. Remaining constant temperature D. varying speed
42. To repair a small electrical motor that has been submerged in saltwater, you should ______.
A. wash it with fresh water and apply an external source of heat B. renew the windings
C. send it ashore to an approved service facility
D. rinse all electrical parts with a carbon tetrachloride cleaning solvent and then blow dry the motor with compressed air
43. The diesel engine consumes considerably less fuel than the steam engine for equal output,
______enables a motor-ship to load more cargo.
A. why B. which C. in which D. on which
44. The conclusion that mechanical efficiency is always ______100 per cent is correct.
A. small than B. more than C. little than D. less than
45. The diesel engine valve subjected to most severe conditions of service is the ______.
A. cylinder exhaust valve B. air starting valve C. air inlet valve D. cylinder relief valve 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. A diesel engine is operating with excessively high exhaust temperatures at all cylinders. To
correct this condition, you should first ______.
A. reduce the engine load B. increase the cooling water flow C. increase the lube oil pressure D. adjust the fuel rack
48. High exhaust temperature and black smoke exhausting from an auxiliary diesel engine can be
caused by ______.
A. engine overload B. low combustion temperature C. plugged fuel nozzle holes D. excessive compression pressure 49. Hearing a strong noise, ______at once.
A. the engine stopped B. the engine was stopped C. he stopped the engine D. he had stopped the engine
50. To correct a hunting problem in a main propulsion diesel engine hydraulic governor, you should
______.
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