单项选择题
A.prevent soot fires in the exhaust system B.prevent exhaust gas erosion of the tubes C.increase the velocity of exhaust gas flow D.increase the rate of heat transfer
On a medium-speed main propulsion diesel engine, the cr...
单项选择题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
The rate of cylinder lubricating oil metered to each cy...
单项选择题The rate of cylinder lubricating oil metered to each cylinder of a large low-speed main propulsion diesel engine is （）
A.the same, whether at sea, or during maneuvering B.adjusted during each hour of operation while at constant RPM C.higher at sea than while maneuvering D.lower at sea than while maneuvering
The crankcases of many diesel engines are kept under a ...
单项选择题The crankcases of many diesel engines are kept under a slight vacuum to （）
A.improve fuel economy B.increase the air charge velocity C.reduce the risk of explosion D.all of the above
