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1、轮机英语A 卷姓名： 成绩： 单项选择题（每题 2 分共 100 分）1. The diesel engine is similar to the gasoline engine in that _.A. Both of them are ignited by compressed airB. Both of them are the forms of external combustion enginesC. Both of them have spark plugsD. The power is developed by the piston in the cylinder2. The r
2、atio of th brake horsepower to the indicated by the _.A. Thermal efficiency B. Mechanical efficiency C. Brake thermal efficiency D. Volumetric efficiency3. The ignition quality, of diesel fuel oil is indicated by the _.A. Specific gravity B. Cetane number C. Viscosity D. Calorific value4. How are th
3、e pressure and temperature affected in a diesel engine cylinder during compression?A. Pressure and temperature decreaseB. Pressure and temperature increase C. Pressure decreases and temperature increasesD. Pressure increases and temperature decreases5. An aluminium piston has lower inertia and highe
4、r coefficient of _compared to that of cast ironA. Viscosity B. Twisting moments C. Inertia D. Thermal expansion6. Each cylinder is closed at the top by a _,made of a special heat-resistant steel.A. Cylinder liner B. Coupling flange C. Cylinder cover D. Piston7. The amount of fuel delivered by a heli
5、cal plunger type fuel injection pump is controlled by_.A. Rotation of the pump plunger B. Rotation of the pump barrel C. Varying the pump supply pressure D. Varying the pump return pressure8. In a diesel engine lube oil system, which of the following parts should be lubricated first?A. Camshaft bear
6、ing B. Main bearing C. Piston crowns D. Cylinder9. Sacrificial zinc anodes are used on he saltwater side of diesel engine heat exchangers to_.A. Reduce electrolytic action on heat exchanger metalsB. Keep heat transfer surfaces shiny and cleanC. Prevent rapid accumulation of marine growthD. Provide a
7、 protective coating on heat exchanger surfaces10. In a turbocharger, inlet air velocity is in creased in the _.A. Inlet nozzle ring B. Stationary diffuser passages C. Compressor outlet volute D. Rotating impeller vanes11. Diesel engine cylinder air start valve timing is controlled by _.A. Engine ope
8、rating speed B. An air manifold C. A hydraulic distributor D. The air distributor12. If the compensating needle valve of a hydraulic governor is opened more than necessary the governor will_.A. Have a larger than normal dead bandB. Produce excessive speed response to a load changeC. Respond slowly t
9、o any change in engine loadD. Stabilize engine speed at the new governor setting13. A pyrometer is an instrument commonly used to measure_.A. Cylinder pressure B. Flame intensity C. Exhaust gas temperature D. Crankshaft axial alignment14. pump up the starting air reservoirs to their maximum pressure
10、 and _the air reservoirs and airA. Open B. close C. Drain D. Vent15. 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 unchangedC. Speed is reduced and torque is increasedD. Speed is so
11、metimes unchanged while torque is increased16. Which of the following statements concerning fire-tube boilers is correct?A. Combustion gases flow through the tubes B. Flames impinge(撞击) on the tube C. Combustion occurs in the tubes D. Water flows through the tubes17. The safety valves should be test
12、ed and adjusted when the boiler survey is _.A. Completed B. Carried out C. Cleaned D. Steamed18. When an auxiliary boiler is panting and emitting black smoke, you should _.A. Increase the fuel oil supply pressure B. Decrease the fuel oil C. Decrease the fuel oil supply pressure D. Increase the air s
13、upply 19. If the feed pump for an auxiliary boiler fails to deliver the feed water to the boiler, the cause may be _.A. High steam pressure in the boiler B. Abnormally high feed-water temperature C. Abnormally high boiler water temperature D. Steam demand exceeding feed pump capacity20. A vane pump
14、belongs to_according to its working principle.A. Reciprocating pump B. Positive displacement pump C. Centrifugal pump D. centripetal pump21. The packing installed in the pump stuffing box is lubricated by_.A. Gravity and feed oil cups B. Grease cups C. Hand during installation D. Leakage through the
15、 stuffing box22. If the capacity of a centrifugal pump decreases gradually over a long period of time, you should_.A. Packing gland B. Mechanical seals C. Lantern rings D. Wearing rings23. Which of the listed conditions can lead to cavitation in a centrifugal pump?A. Vapor pockets formed in the suction flow steamB. Rough casing volute surfaces.C. Worn wearing rings D. Heavy fluid m the flow stream24. In a compression refrigeration plant, the hot, high pressure refrigerant gas is cooled by the sea water and become
