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单选题
When distilling sea water the cooling water discharging from the distiller is fed back to evaporator as feed water （）.
A
to decrease scale formation
B
for better cooling effect
C
for more economical purpose
D
to raise vacuum
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单选题Which of the following factors tends to increase scale formation on the saltwater side of a heat exchanger used in a diesel engine cooling water system?（）A
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A fouled sea chestC
A restricted water passage in the engineD
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pollutionD
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考题
单选题When distilling salt water the cooling water discharging from the distiller is fed back to evaporator as feed water （）.A
to cut down the amount of cooling water neededB
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单选题（） is used for cylinder and cylinder head, the salt water is used for cooling the lubricating oil, the fresh water in the coolers and the charging air in the air cooler.A
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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
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单选题Which of the following statements is correct concerning diesel engine cooling water systems?（）A
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单选题In a diesel engine jacket water cooler, with seawater cooling the fresh water, the（）A
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单选题Which of the following methods is normally used to control the temperature of air distributed from individual cooling coils in an air conditioning system using a chilled water circulation system?（）A
A room thermostat activates an electric heater at each individual chilled air outlet when necessaryB
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Varying the temperature of the water through the coilsD
Varying the quantity of water flowing through the coils
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单选题When is the density of the water required to be logged in the logbook of a ship?（）A
Any time the vessel moves from water of one density into waters of a different densityB
Prior to getting underway when the vessel is floating in fresh or brackish waterC
Only when the vessel moves from fresh water into salt waterD
The density of the water is not required to be logged in the unofficial logbook
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单选题When a refrigeration compressor has developed a high head pressure as a result of a refrigerant overcharge, you should （）.A
increase the amount of cooling water to the condenserB
decrease the amount of cooling water to the condenserC
add more refrigerant to the systemD
remove some refrigerant from the system
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单选题In a central cooling system, used in some modem ships, sea water is supplied to cool （）which will circulate to other individual cooler, greatly reducing the corrosion problems.A
main bearingsB
sea waterC
cooling oilD
lower temperature fresh water
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单选题If the compressor-discharge temperature is higher than the receiver temperature（）A
increase the amount of cooling water to the condenserB
decrease the amount of cooling water to the condenserC
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remove some of the refrigerant from the system
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