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单选题
Cooling water pumps driven by direct reversing diesel engines are usually of the straight impeller vane type pump with a concentric housing to（）
A
facilitate bi-directional operation
B
provide the greatest pump efficiency
C
prevent pump clogging from marine growth
D
prevent cavitation at the pump outlet
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考题
The cooling water of the diesel engine should be treated with chemical, because it contains .A.alkaliB.acidityC.salinityD.impurity
考题
High diesel engine cooling water temperatures can be caused by ______.A.air in the cooling systemB.an overhauled water pumpC.correct amount of coolantD.no air in the cooling system
考题
单选题If a diesel engine were running at 20% overload with a smoky exhaust, you should（）A
stop the engine immediately to prevent damageB
increase lube oil pressureC
slow the engine allowing it to gradually coolD
decrease the cooling water it temperature to the water jacket
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单选题The device allowing for the change in volume of the cooling water in a propulsion diesel engine closed cooling system is the （）.A
fresh water expansion tankB
sea water expansion tankC
thermostatic expansion valveD
jacket water cooler accumulator
考题
单选题One of the purposes for water cooling the exhaust manifold in marine diesel engine is to （）A
reduce lube oil temperatureB
raise exhaust temperature reduceC
excessive heating of engine roomD
reduce load on cooling water pump
考题
单选题The purpose of treating the cooling water of the diesel engine is to（） Ⅰ. resist the scale formation in the cooling chamber Ⅱ.lubricate the engine part Ⅲ.increase thermal capacity Ⅳ.resist corrosionA
Ⅰ+ⅡB
Ⅱ+ⅢC
Ⅲ+ⅣD
Ⅰ+Ⅳ
考题
单选题If the cooling water temperature and the lube oil temperature in a diesel engine are too high, the cause can be （）A
a dirty lube oil strainerB
internal water leaksC
an oil suction line restrictionD
excessive wears of the cooling water pump
考题
单选题Why the cooling water of the diesel engine should be treated? Because the（）A
Cooling water is alkalescenceB
cooling water is acidityC
cooling water has salinityD
cooling water has impurity
考题
单选题If the jacket water temperature in an auxiliary diesel engine cooling system is lower than normal, the probable cause is （）A
air binding of the engine cooling systemB
a cracked water cooled exhaust manifoldC
blockage in the heat exchangerD
faulty operation of the thermostat
考题
单选题In order to reverse the rotation of a two-stroke/cycle loop scavenged, direct reversing, propulsion diesel engine, the cam positions must be changed for the （）.A
starting air and fuel pumpsB
piston cooling pumpsC
exhaust valvesD
all of the above
考题
单选题High diesel engine cooling water temperatures can be caused by （）.A
air in the cooling systemB
an overhauled water pumpC
correct amount of coolantD
no air in the cooling system
考题
单选题In a closed cooling system for a turbocharged, four-stroke/cycle diesel engine, fluctuating water pressure can be caused by （）A
improper venting of the cooling systemB
carrying the expansion tank water level too highC
a totally clogged impeller in the cooling water pumpD
an incorrectly set cooling system temperature control
考题
单选题The expansion tank for a diesel engine closed cooling system is designed to maintain a constant head on the system and （）.A
reduce water temperatureB
reduce water turbulenceC
provide an air cushionD
allow for an increase in water volume as the engine warms up
考题
单选题Corrosion inhibitors and/or soluble oils are added to diesel engine cooling systems to （）A
maintain low pH in the cooling waterB
reduce the cooling water temperatureC
increase cooling water hardnessD
form a protective film on metal surfaces
考题
单选题During maneuvering operations for a direct reversing large, low-speed, main propulsion diesel engine, which of the following actions is used to stop the shaft from turning prior to reversing the engine rotation?（）A
Flywheel inertiaB
Admission of starting airC
The way of the vesselD
securing of fuel to the cylinders
考题
单选题The cooling water of the diesel engine should be treated, because it has（）A
alkale scenceB
acidityC
salinityD
impurity
考题
单选题In a diesel engine cooling system, the high temperature alarm contact maker will be activated on excessively high water discharge temperature from the （）A
raw water pump dischargeB
expansion tank outletC
cooling water heat exchangerD
outlet engine jacket water outlet
考题
单选题Which of the following statements is correct concerning diesel engine cooling water systems?（）A
Each engine must have its own engine driven cooling water pump capable of providing cooling for all ranges of operationB
propulsion engines with bores exceeding 200 mm are to be fitted with a means to display the cooling water temperature of each cylinderC
At least two independent sea suctions are to be provided for supplying water to the engine jackets or to the heat exchangersD
Suitable strain are to be fitted between the circulating pumps and heat exchangers when sea water is used for direct cooling
考题
单选题If the water level dropped rapidly in the expansion tank of a closed diesel engine cooling water system, you should suspect a （）.A
loss of suction in the circulating pumpB
leak in the primary cooling systemC
broken raw water pump shaftD
burned or cracked piston in one cylinder
考题
单选题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 systemB
Cavitation in the cooling water pumpC
Opened vent in the cooling systemD
Restricted water passages in the engine
考题
单选题Temperature control valves installed in the jacket cooling water system of a diesel engine modulates the rate of water flow through the （）.A
cooling water pumpB
nozzle cooling passagesC
cylinder jacketsD
heat exchanger
考题
单选题In a diesel engine cooling water system, a pH of 60 indicates a/an （）.A
slightly acidic conditionB
slightly alkaline conditionC
overtreatment of waterD
neutral condition of water
考题
单选题About the jacket water, that of the auxiliary engines usually（） is circulated by pumps, and the main engine usually （）A
an engine-driven；as wellB
an engine-driven；has an independent pumpC
an independent；as wellD
an independent；has an engine-driven pump
考题
单选题Fuel oil transfer systems used onboard diesel propelled vessels are required to have （）.A
two fuel oil transfer pumps provided where one is to be independent of the main engineB
two fuel oil transfer pumps, with a combined capacity exceeding the maximum consumption of the main engineC
engine driven transfer pumps and only used in constant speed applicationsD
the capacity of the engine driven pump exceed the consumption rate of the engine to which it is attached
考题
单选题Which of the following conditions will develop if the flow of ‘raw’ cooling water to diesel engine is obstructed?（）A
Air will enter the cooling systemB
Carbon will plug the water cooled exhaust manifoldsC
The jacket water temperature will riseD
The lube oil viscosity will increase
考题
单选题In the process of the stand-by, warm-up the engine usually through give preheat of which parts of the diesel engine?（）A
cooling water of the cooling systemB
fuel of the FO systemC
LO of the LO systemD
cooling water of the cooling system and LO of the LO system
考题
单选题High diesel engine cooling water temperatures can be caused by （）.A
a worn water pumpB
not enough coolantC
air in the cooling systemD
all of the above
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