更多"If a four-stroke/cycle diesel engin"的相关试题:
[单项选择]Before a marine diesel engine is started the cylinders and pistons must be ().
A. cooled to appropriate temperature
B. warmed up gradually to appropriate temperature
C. opened up and renewed
D. ground and polished
[单项选择]A marine diesel engine is started by()
A. supplying high pressure oil into a hydraulic motor
B. supplying high temperature air into the cylinder
C. supplying high pressure air into the cylinder
D. electrical igniting
[单项选择]Immediately after any diesel engine is started, the engineer should check the ()
A. crankcase pressure
B. lube oil pressure
C. saltwater pressure
D. exhaust temperature
[单项选择]A two-stroke/cycle diesel engine requires less starting air than a four-stroke/cycle diesel engine, of equal displacement, because the two-stroke/cycle diesel engine()
A. has little or no internal friction
B. has a lower effective compression ratio
C. operates with scavenge air under a positive pressure
D. operates without energy absorbing intake and exhaust strokes
[单项选择]The camshaft on a four-stroke/cycle diesel engine provides a means to operate the ().
A. fuel injectors
B. exhaust valves
C. intake valves
D. all of the above
[单项选择]Scavenging in a four-stroke/cycle diesel engine occurs during the ().
A. last part of the exhaust stroke, and the first part of the intake stroke
B. last part of the intake stroke only
C. early part of the injection stroke only
D. early part of the power stroke
[单项选择]In a four-stroke cycle diesel engine the intake valves open ()
A. before TDC and close after BDC
B. after TDC and close after BDC
C. before TDC and close before BDC
D. after TDC and close before BDC
[单项选择]A turbocharged, four-stroke/cycle diesel engine has a larger valve overlap than a naturally aspirated four-stroke/cycle diesel engine, in order to in crease the ().
A. temperature of the exhaust gases
B. energy supplied to the turbocharger
C. air pressure to the intake manifold
D. purge of exhausted gases from the cylinders
[单项选择]In a turbocharged four-stroke/cycle diesel engine, the exhaust valve remains open until after top dead center and the intake valve opens before top dead center to().
A. produce a scavenging effect in the combustion space
B. equalize cylinder and exhaust manifold pressures
C. alleviate the difference in valve size between the intake and exhaust
D. flush out condensate that collects after each compression stroke
[单项选择]A disadvantage of a two-stroke/cycle diesel engine is()
A. more power strokes per revolution
B. the use of scavenge air
C. more complicated valve gear
D. higher working temperature of the piston and cylinder
[单项选择]A four-stroke/cycle, 1000horsepower diesel engine fails to start at normal cranking speed with normal fuel pressure and ambient temperatureThe reason for the failure could be()
A. glazed liners or pistons
B. high lube oil pressure
C. excessive compression ratio
D. worn valve seats and valves
[单项选择]A piston in a four-stroke/cycle diesel engine makes four strokes during each ().
A. crankshaft revolution
B. mechanical cycle of operation
C. period of two combustion cycles
D. cycle of two events
[单项选择]If a four-stroke/cycle diesel engine is running at 1550 RPM, the speed of the camshaft will be().
A. 525 RPM
B. 775 RPM
C. 1550 RPM
D. 1800 RPM
[单项选择]In a four-stroke/cycle diesel engine, the camshaft rotates at ()
A. twice the crankshaft speed
B. half the crankshaft speed
C. the same speed as that of the crankshaft
D. a speed independent of that of the crankshaft
[单项选择]
The working cycle of a four-stroke diesel engine consists of four events:()
(1) compression
(2) expansion
(3) exhaust
(4) suctionThe correct sequence is
A. (4)-(2)-(3)-(1)
B. (4)-(3)-(1)-(2)
C. (4)-(3)-(2)-(1)
D. (4)-(1)-(2)-(3)
[单项选择]The diesel engine must be started before it can run by it self For this purpose () has to be used.
A. a starting system
B. the starting air
C. a starting operation
D. A, B and C
[单项选择]A six-cylinder, two-stroke/cycle diesel engine is fitted with a rotary distributing air starting systemThe speed of the rotating distributor disc is ()
A. one-half engine speed
B. the same as engine speed
C. twice engine speed
D. four times engine speed
[单项选择]In a two-stroke/cycle diesel engine, the exhaust gases are expelled from the cylinder by the()
A. exhaust manifold
B. valve bridge
C. pressure of the fresh air charge
D. valve adjusting gear
[单项选择]In a four-stroke/cycle diesel engine, after the completion of the power stroke, the piston will move()
A. up and draw in a fresh air charge
B. down to burn off fuel
C. down to compress the fuel air charge
D. up and force out the exhaust gases