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单选题
Which of the following may hardness of the boiler water cause?（） (1) scale formation (2) tube failure (3) corrosion
A
（1）and（2）
B
（1）and（3）
C
（2）and（3）
D
（1），（2）and（3）
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what chemicals did you use to treat the boiler water ?when you test alkalinity and acidity of water in boiler by pH test paper ? the result shows the boiler water is in acidiity . please describe what the possible cause is .
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If the feed pump for an auxiliary boiler fails to deliver the feed water to the boiler, the cause may be ______.A.high steam pressure in the boilerB.abnormally high feed-water temperatureC.abnormally high boiler water temperatureD.steam demand exceeding feed pump capacity
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The boiler water alkalinity in a coil-type auxiliary boiler should be maintained at the pH recommended by the boiler manufacturer to______.A.precipitate(使沉淀) silica （硅石）from solutionB.reduce corrosion in the heating coilC.prevent clogging and erosion in the coilD.maintain zero water hardness
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单选题Which of the following items is necessary for all waste heat boiler installations, regardless of design or manufacturer? （）A
Control of evaporationB
A separate means to prevent feed-water contaminationC
Power circulating pumpD
Super-heater
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单选题Which of the following operations may be dangerous?A
Overfilling the cooker with food and water.B
Cleaning the cooker with detergent.C
Cooling the cooker with cold water.D
Setting too little cooking time.
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单选题The water level of an exhaust gas boiler which is independent of the auxiliary boiler and just as the extra heating surface of it （）A
will be modulated in proportionB
will be modulated in proportion and integralC
will be modulated in proportion and differentialD
will not be modulated at all
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单选题Which statement concerning the collection of fresh water is FALSE?（）A
Fresh water may be obtained from fishB
lifeboat covers or canopies should be washed with rain before drinking water is collectedC
Fresh water may be collected from condensation inside the life-raftD
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单选题Which of the following statements concerning the water tube and fire tube boilers is not true?（）A
natural circulation of the water in the water tube boiler is better than that in the fire tube boilerB
for the same output the water tube boiler will carry less mass of water compared with the fire tube boilerC
the water tube boiler will cost shorter time for steam raisingD
the water tube boiler require lower skill in operating and maintaining
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单选题In readying an auxiliary water-tube boiler for a routine hydrostatic test, which of the following procedures should be undertaken prior to filling the boiler with fresh water?（）A
The safety valve escape piping should be disconnected from the valve body and a blank insertedB
The boiler vent valves should be openedC
All hand-hole/manhole covers should be tightened up as much as possible to preclude any leaksD
All of the above
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单选题The rate of heat transfer in a water-tube auxiliary boiler can be increased by （）.A
operating the boiler at less than normal water levelB
installing fins on the firesides of water-tubesC
increasing the amount of excess air to the burnersD
treating the boiler water with chemical oxygen scavengers
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单选题In readying an auxiliary water-tube boiler for a routine hydrostatic test, which of the following procedures should be undertaken prior to filling the boiler with fresh water?（）A
The safety valve escape piping should be disconnected from the valve body and a blank insertedB
The boiler vent valves should be openedC
All handhole/manhole covers should be tightened up as much as possible to preclude any leaksD
All of the above
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单选题A distorted furnace in a fire-tube auxiliary boiler may be the result of （）A
firing for extended periods in the low fire modeB
overheating, due to waterside depositsC
varying the water level above the crown sheetD
carrying excessive alkalinity in the boiler water
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单选题The donkey boiler may be given a bottom blow （）A
to raise water levelB
only while making steamC
to remove scumD
when fire are secured
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单选题For proper operation, auxiliary boiler feed water must have which of the following characteristics?（）A
High oxygen concentrationB
Low pHC
Proper alkalinityD
All of the above
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单选题According to the passage, which of the following statements is TRUE?A
All the universities have banned the sale ofbottled water.B
Plastic bottles may do harm to people's health.C
The purchase of soft drinks will increase.D
Bottled water is cheap and environment-friendly.
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单选题The boiler water alkalinity in a coil-type auxiliary boiler should be maintained at the pH recommended by the boiler manufacturer to（）A
precipitate silica from solutionB
reduce corrosion in the heating coilC
prevent clogging and erosion in the coilD
maintain zero water hardness
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inspected carefullyB
placed in serviceC
undertaken with careD
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An economizerB
An attemperatorC
A water dramD
A down-comer tube
考题
单选题If the feed pump for an auxiliary boiler fails to deliver the feed water to the boiler, the cause maybe （）.A
high steam pressure in the boilerB
abnormally high feed water temperatureC
abnormally high boiler water temperatureD
steam demand exceeding feed pump capacity
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单选题Which of the following may cause that excessively warm water leaves the condenser in a refrigeration plant? （） (1) too little cooling water (2) too much cooling water (3) too warm cooler waterA
（1）onlyB
anyof（1），（2）and（3）C
anyof（1）and（3）D
anyof（1）and（2）
考题
单选题Which statement concerning the collection of fresh water is FALSE?（）A
Fresh water may be obtained from fishB
Lifeboat covers or canopies should be washed with rain before drinking water is collectedC
Fresh water may be collected from condensation inside the liferaftD
Seawater should never be consumed
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单选题Which of the following conditions may need to be reduced when operating a large, low speed, main propulsion, diesel engine at low loads?（）A
Injection pressuresB
Control air supply pressureC
Cooling water flow through after-coolersD
Lube oil temperature
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