單項選擇題Injectors for use with heavy fuel oil must be cooled by either water or light oil to （）

A.prevent heat corrosion to internal components
B.increase fuel delivery rate and economy
C.prevent pre-ignition
D.avoid carbonization of the nozzle tips


您可能感興趣的試卷

你可能感興趣的試題

1.單項選擇題If the water level dropped rapidly in the expansion tank of a closed diesel engine cooling water system, you should suspect a （）

A.loss of suction in the circulating pump
B.leak in the primary cooling system
C.broken raw water pump shaft
D.burned or cracked piston in one cylinder

2.單項選擇題To minimize the formation of carbon deposits on fuel injection nozzles, you should （）

A.avoid using liquid-cooled nozzles whenever possible
B.avoid low cooling water temperatures
C.avoid prolonged overloading of the engine
D.make certain the gasket seal between the nozzle and cylinder head is tight

3.單項選擇題In a simple mechanical governor, the （）

A.centrifugal force rotates the ball-head
B.flyweight centrifugal force is balanced by spring force
C.flyweight centrifugal force is balanced by hydraulic pressure
D.speeder spring alone actuates the fuel control rod

4.單項選擇題If a diesel engines exhaust temperature is abnormally high, the cause could be（）

A.too light of a load
B.injection timing is too early
C.overloading of the engine
D.too low of a compression ratio

5.單項選擇題The knock occurring when a cold diesel engine is started and continues while running at low speed, but stops when the engine reaches normal operating speed and temperature, is（）.

A.caused by retarded injection timing
B.caused by a mechanical defect in one cylinder
C.caused by high fuel injection pressures
D.normal for these conditions