Operating a propulsion diesel engine at less than 30% of designed normal load for prolonged periods will result in （）.
A . decreased fuel consumption per brake horsepower
B . more complete cylinder scavenging
C . extended valve life
D . carbon formation on combustion chamber surface
相似题目
-
A large, low-speed, crosshead, main propulsion diesel engine using residual fuel oils must have a cylinder oil having a （）
A、the use of a poor quality oil
B、the deterioration of its properties
C、the formation of deposits
D、the reduction in heat transfer ability
-
Loss of lubricating oil pressure to the main propulsion diesel engine will actuate a/an （）.
A . overspeed trip
B . audible/visual alarm
C . the ships/boats general alarm
D . reserve oil storage tank
-
A possible cause for an individual piston to knock when at TDC on a slow-speed, two-stroke/cycle main propulsion diesel engine could be due to （）
A . early fuel injection
B . excessive bearing play within the running gear
C . overloading of the cylinder
D . all of the above
-
On a medium-speed main propulsion diesel engine, the crank-pin or crank journal bearings receive lubricating oil from （）.
A . a spindle lubricator
B . an oil jet
C . internal splashing
D . drilled passages in the crankshaft
-
A water jacket is placed around the exhaust manifolds of propulsion diesel engines to（）
A . reduce heat radiation to the engine room
B . aid in preventing turbocharger overheating
C . condense and drain moisture from exhaust gases
D . dampen exhaust gas pulsations in the manifold
-
In a main propulsion turbocharged diesel engine, the speed of the turbocharger varies according to the （）
A . governor droop
B . speeder spring tension
C . fuel rack lag
D . load on the engine
-
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 dow
-
The four-stroke engine is used for （） and sometimes for main propulsion with a gearbox to provide a propeller speed of between 90 to 120 rev/min.
A . alternator
B . turbo-charger
C . remote controller
D . windla
-
A large, low-speed, main propulsion diesel engine uses sea water to directly cool the （）.
A . cylinder heads
B . exhaust valves
C . scavenging air
D . injector
-
A defective injector nozzle in a propulsion diesel engine can cause（）
A . engine power losses
B . smoking due to unburned fuel
C . high exhaust temperature readings
D . all of the above
-
On a large low-speed main propulsion diesel engine, lower main bearing wear is usually measured by using a/an （）
A . dial indicator
B . outside caliper
C . bridge gauge
D . tram rod
-
Which of the following problems can cause fluctuating pressures in the closed cooling system of a main propulsion diesel engine?（）
A . Defective temperature controls in the system
B . Cavitation in the cooling water pump
C . Opened vent in the cooling system
D . Restricted water passages in the engine
-
After a liferaft is launched，the operating cord（）.
A . serves as a sea painter
B . detaches automatically
C . is used to rig the boarding ladder
D . is cut immediately as it is of no further use
-
“John killed Bill but Bill didn’t die” is a (n) （）.
A . entailment
B . presupposition
C . anomaly
D . contradictio
-
A thrust bearing is used with a propulsion diesel engine to （）.
A . control axial movement of the crankshaft
B . transmit engine thrust to the propeller shaft
C . absorb vibrations in the propeller shafting
D . prevent propeller thrust from being transmitted to the hul
-
One major disadvantage of a low-speed diesel as compared to a steam main-propulsion system is（）.
A . the extra weight required for the diesel reduction gearing
B . a minimum speed for the engines that limits the minimum speed of the vessel
C . the higher fuel consumption per SHP
D . the low efficiency of the system when a controllable pitch propeller is used
-
Critical speeds occurring within the operating speed range of a main propulsion diesel engine may be changed, or have their damaging effects reduced by a/an （）
A . engine support vibration isolator
B . detuner or viscous fluid damper
C . lightened crankshaft flywheel
D . spherically seated crankshaft bearing
-
Diana died on Sunday, August 31，1997, following a () crash in Paris.
-
Mary washed for a living after her husband died of cancer.
-
Martha is managing a projectthat has a degree of operating leverage equal to 2.1. How will the operating cash flows change if the quantity solddecreases by 4 percent?
-
What happens AFTER a star dies？
A．It becomes invisible.
B．It falls to Earth.
C．It burns up all of its gases.
D．It becomes brighter and easier to see.
此题为多项选择题。
-
What happens to a female elephant when it dies？
A．The others take a little of its corpse away.
B．The others eat its dead body.
C．The others bury it near their home.
D．The others leave its dead body there.
-
It was said that he died______a fever.
A．in
B．by
C．of
D．from
-
Mary felt lonely after her husband died in a car accident.
A．alone
B．gloomy
C．desolate
D．separate
