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单选题
Maintaining the lowest possible scavenging air temperature at all times is not recommended due to the possibility of the （）.
A
air charge density becoming too high
B
piston crown surfaces becoming too cold
C
formation of excessive quantities of condensate
D
compression pressure being greatly reduced
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Maintaining the lowest possible scavenging air temperature at all times is not recommended due to the possibility of the ______.A.air charge density becoming too highB.piston crown surfaces becoming too coldC.formation of excessive quantities of condensateD.compression pressure being greatly reduced
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考题
单选题The dew point temperature is（）.A
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单选题Why are some diesel engine cylinder liners plated on the wearing surface with porous chromium?（）A
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The chromium strengthens the liners in the way of the scavenging air portsC
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单选题A two-stroke diesel engine exhaust temperature will be lower than a four-stroke diesel engine of the same displacement because the （） (1) MEP is lower and the scavenging air is cooling the exhaust gases (2) valve overlap in a four-strokeA
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考题
单选题Exhaust temperature increases in all cylinders, the possible cause may be（） (1) increased scavenging air temperature (2) air in fuel pumps and fuel valves (3) fouling of air and gas passagesA
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考题
单选题Sweat damage will occur in a cargo hold containing machinery parts when（）.A
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单选题The term diesel engine scavenging means（）A
delivering more air into the cylinder than it would normally receive during an ordinary charging processB
forcing the products of combustion out of the cylinder with the fresh air chargeC
collecting the air charge at the cleanerD
combustion and expansion of hot gas
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单选题Scavenging is （） of exhaust gases by blowing in fresh air.A
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the deliver
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compression ratioC
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单选题Which condition indicates the air side fouling of an after-cooler on a turbocharged diesel engine?（）A
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单选题To prevent the unnecessary loading of an air conditioning system while maintaining the designed dry bulb temperature and relative humidity in an air conditioning system, you should （）A
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考题
单选题On what do you depend having the air cooler of main engine chemically washed?（）A
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reduced temperature difference between water inlet and outletD
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考题
单选题The process of scavenging a two-stroke/cycle diesel engine serves to（）A
improve fuel flow volumeB
cool the exhaust valvesC
reduce the intake air charge densityD
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考题
单选题The principal difference between loop scavenging and crossflow scavenging, as used in single acting diesel engines, is the （）A
direction of air flow within the cylinderB
sequence of port openingC
method of opening exhaust portsD
volume of air admitted to the cylinder
考题
单选题Fuel has been injected but ignition fails The possible cause may be （）.A
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考题
单选题Which of following functions is not one of the functions of air conditioner?（）A
refreshing the airB
making person upsetC
adjusting the air humidityD
adjusting the air temperature
考题
单选题A two-stroke diesel engine exhaust temperature will be lower than a four-stroke diesel engine of the same displacement because the （） (1) scavenging air is cooling the exhaust gases (2) exhaust cycle time is longerA
(1) onlyB
(2) onlyC
both (1) and (2)D
neither (1) nor (2)
考题
单选题A space should be ventilated when（）.A
The cargo's temperature is colder than the dew point of the air in the spaceB
The cargo's temperature is warmer than the dew point of the air in the spaceC
The dew point of the air in the space is lower than the dew point of the outside airD
All of the above
考题
单选题The effective temperature of air is dependent upon（） Ⅰ.relative humidity Ⅱ.air velocityA
ⅠonlyB
ⅡonlyC
Both Ⅰand ⅡD
NeitherⅠnor Ⅱ
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