更多"The crankcases of many diesel engin"的相关试题:
[单项选择]The crankcase of many diesel engines are kept under a slight vacuum by the （）.
A. scavenging action of the piston
B. piston type vacuum pump taking suction off a differential manometer
C. gland exhausting manometer
D. crankcase exhaust fan
[单项选择]Many diesel engine exhaust valves are being constructed with hollow stems filled with sodium in order to （）
A. provide added wear protection against today’s corrosive quality of fuel
B. increase overall valve strength due to the high gas pressures
C. assist in dissipating heat due to the extreme operating temperatures
D. reduce the overall weight of the valve thus helping eliminate valve spring surge and hammering
[单项选择]The marine diesel engine is a type of diesel engine used on ships The （） of its operation is not very difficult to understand.
A. principle
B. principal
C. cause
D. case
[单项选择]Diesel oil may be used to cool （） of a diesel engine.
A. cylinders
B. exhaust valves
C. pistons
D. fuel valves
[单项选择]Mechanical lubricators for diesel engine cylinders are usually small reciprocating pumps which are （）.
A. operated manually once an hour
B. operated until the engine has started
C. placed into operation only at maximum load
D. adjustable to meet lubrication requirements
[单项选择]Diesel engine mufflers accomplish noise reduction by （）
A. reducing exhaust gas velocity
B. increasing the frequency of gas vibration
C. the use of long head pipes
D. the use of zinc electrodes
[单项选择]Diesel fuel vapors （）.
A. can not be ignited by a spark unless the vapor is in a confined space
B. are nontoxic in all concentrations
C. can not be ignited by a spark unless they are at their auto-ignition temperature
D. are heavier than air
[单项选择]An emergency diesel generator should automatically shut down in the event of （）
A. dangerous over-speeding
B. a loss of lube oil pressure
C. activation of the fixed CO2 system for the emergency generator space
D. all of the above
[单项选择]The diesel engine consumes considerably less fuel than the steam engine for equal output, （） enables a motor-ship to load more cargo.
A. why
B. which
C. in which
D. on which
[单项选择]Constant cooling the various components of diesel engine has a number of functions except for （）.
A. good lubrication
B. low thermal stress
C. good mechanical properties
D. acid corrosion
[单项选择]Lubricating systems for diesel engines are usually designed to initially provide lube oil to the engine （）
A. camshaft beatings
B. main bearings
C. piston crowns
D. cylinder walls
[单项选择]Diesel engines driving alternators operating in parallel must maintain set frequency regardless of load changesThe governor characteristic used to accomplish this is known as （）
A. actuation
B. sensitivity
C. compensation
D. thrust shaft
[单项选择]Crankcase explosions in propulsion diesel result from（）
A. the splashing of lubrication oil by the crankshaft
B. the dilution of crankcase oil with particles of combustion
C. broken fuel lines spraying oil on the crankcase
D. the ignition of unburned fuel and air in the crankcase
[单项选择]Modern marine diesel engines using mechanical fuel injection, operate on a combustion cycle which is（）
A. a combination of constant volume and constant pressure
B. a combination of constant temperature and constant pressure
C. entirely constant pressure
D. entirely constant volume
[单项选择]Diesel engine fuel oil contamination often results in （）
A. governor malfunctions
B. fuel injection system malfunctions
C. high cylinder lube oil temperatures
D. low intake temperatures
[单项选择]Diesel engine crankshaft deflection readings are generally taken at four crank positionsGood engineering practice requires the deflection gage or indicator to be（）
A. placed as near the crankpin axis as possible
B. removed each time the crankshaft is repositioned
C. left in place for all four readings
D. reset to zero for all four readings
[单项选择]The main operating characteristic of diesel engines which distinguishes them from other internal combustion engines is the （）
A. method of supplying air
B. cooling system
C. method of igniting fuel
D. valve operating mechanism
[单项选择]An operating turbocharged diesel engine that suddenly loses power, is due to a/an（）
A. restricted turbocharger air intake
B. oil leak into the turbocharger
C. dribbling injector
D. low fuel viscosity
[单项选择]High diesel engine cooling water temperatures can be caused by （）.
A. air in the cooling system
B. an overhauled water pump
C. correct amount of coolant
D. no air in the cooling system
