海船船员考试
单选题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 horsepowerB more complete cylinder scavengingC extended valve lifeD carbon formation on combust
题目
decreased fuel consumption per brake horsepower
more complete cylinder scavenging
extended valve life
carbon formation on combustion chamber surfaces
相似问题和答案
第1题：
Prolonged operation of a diesel engine with a closed cooling water system, at lower than normal designed operating temperatures can ______.
A.increase power output
B.decrease lube oil viscosity
C.eliminate fuel knock
D.cause sulfuric acid formation
第2题：
What is an advantage of diesel over steam turbine propulsion ________．
A.Less fuel consumption per SHP
B.Diesel fuel costs less than bunker C or its equivalent
C.Less routine maintenance required
D.Less weight per SHP
第3题：
Proper lubrication of the main bearings is more easily obtained in a single acting, four-stroke/cycle diesel engine than in a tow-stroke/cycle diesel engine because________.
A.The direction of pressure on the journal in four-stroke engine is continuously
B.positive feed lubricators are installed on all bearings of four-stroke engine, whereas as a splash feed system is used on tow-stroke engine
C.four-stroke engines usually utilize a heavier grade of oil than tow-stroke engines
D.Low-stroke engines usually consume less lube oil than four-stroke engines
第4题：
Exhaust temperature
Lube oil level
Lube oil pressure
Water level in the expansion tank
第5题：
why
which
in which
on which
第6题：
The relative air pressure in the inlet manifold of a turbocharged diesel engine is usually______.
A.greater than the average exhaust manifold pressure
B.less than the average exhaust manifold pressure
C.greater at the turbine wheel than at the impeller
D.greater at reduced engine speed
第7题：
the same, whether at sea, or during maneuvering
adjusted during each hour of operation while at constant RPM
higher at sea than while maneuvering
lower at sea than while maneuvering
第8题：
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
第9题：
increasing the quantity of starting air
increasing the lube oil pressure
heating the engine fuel supply
heating the engine coolant
第10题：
control axial movement of the crankshaft
transmit engine thrust to the propeller shaft
absorb vibrations in the propeller shafting
prevent propeller thrust from being transmitted to the hul