更多"A fuel injection valve opening at p"的相关试题:
[单项选择]During the fuel injection period, fuel pressure must exceed cylinder gas pressure to （）.
A. ensure penetration and distribution of the fuel in the combustion chamber
B. ensure the needle valve is flushed clean during each injection
C. prevent combustion gas blowback into the open needle valve
D. prevent reflected pressure waves when the needle valve closes
[单项选择]In conventional systems, the injection pressure（）, while it’s（）in common rail diesel engines.
A. fluctuates with the engine speed to some extent, independent of the engine speed
B. keeps constant at all engine speed, dependent on the engine speed to some extent
C. keeps constant at all engine speed, independent of the engine speed
D. is decided by the engine speed, constant at all engine speed
[单项选择]Either a low injection pressure or a leakage of piston rings is able to lead （）.
A. a high exhaust temperature
B. a high smoky exhaust
C. a high output
D. a high compression
[单项选择]The high pressure in fuel injection system of the diesel engine is produced by the （）.
A. injector pump
B. fuel injector
C. governor
D. turbocharger
[单项选择]The needle valve in a fuel valve will （） when the fuel pressure action on the needle valve tapered face exerts a force lower than that of the spring compression.
A. be jammed
B. be opened
C. be seated
D. be broken
[单项选择]If the needle valve in a fuel injection nozzle sticks open （）.
A. no fuel will be delivered through the nozzle
B. the nozzle will overheat and crack
C. time of injection will change
D. fuel will leak into the drain line
[单项选择]The high-pressure fuel opens the fuel valve and is sprayed into the cylinder in tiny droplets known as （）.
A. injection
B. penetration
C. atomization
D. compression
[单项选择]Dirt lodged on the nozzle valve seat of a fuel injection nozzle will cause（）
A. erosion and cratering of the nozzle orifices
B. fuel leakage into the nozzle drain line
C. fuel leakage before and after injection
D. insufficient fuel delivery though that nozzle
[单项选择]The needle valve will open when the fuel pressure acting on the needle valve （） exerts a sufficient force to overcome the spring compression.
A. tape face
B. tapered face
C. surface
D. thinner face
[单项选择]When the opening pressure of a diesel fuel injector is greater than that specified by the engine manufacturer，the （）
A. quantity of fuel injected is decreased
B. quantity of fuel injected will always be increased
C. start of injection is advanced
D. duration of injection will always be greater
[单项选择]When the opening pressure of a diesel engine fuel injector is greater than that specified by the engine manufacturer, which of the following problems can be expected?（）
A. Quantity of fuel injected tends to be decreased
B. Quantity of fuel injected will always be increased
C. Start of injection tends to be advanced
D. Duration of injection will always greater
[单项选择]The size of the exhaust valve opening is （）
A. most critical in a four-stroke cycle diesel engine
B. most critical in a two-stroke/cycle diesel engine
C. most critical in a four-stroke/cycle diesel engine if it is turbocharged
D. of equal importance in a two-stroke/cycle diesel engine as in a four-stroke/cycle diesel engine
[单项选择]The opening of an exhaust valve on a modem, large, low-speed, main propulsion diesel engine may be actuated by （）.
A. direct action of cam shaft
B. compressed air pressure
C. hydraulic “push rods”
D. direct action of the main piston moving down
[单项选择]A fuel-air mixture below the lower explosive limit is too（）.
A. rich to burn
B. lean to burn
C. cool to burn
D. dense to burn
[单项选择]Fuel injection systems meter fuel, atomize fuel, and （）.
A. create turbulence in the combustion chamber
B. aid in completing cylinder scavenging
C. inject fuel at the proper time
D. minimize fuel penetration into the cylinder
[单项选择]Increasing the valve clearance between a valve stem and rocker arm, will result in the valve （）
A. closing later
B. opening sooner
C. staying open for a shorter period of time
D. staying open for a longer period of time
[单项选择]Machinery driving fuel oil transfer and fuel oil service pumps must be fitted with a remote means of stopping the machinery from （）.
A. within the space concerned
B. outside the space concerned
C. the throttle station
D. within the fire room
[单项选择]Fuel injectors used in heavy fuel oil systems are usually provided with cooling to reduce（）.
A. cold corrosion of the nozzles
B. fuel viscosity for better atomization
C. carbon accumulation on the nozzles
D. fuel detonation in the cylinders
