轮机英语船舶辅助机械章节练习(2017.11.27)

单项选择题
Which of the following statements is true concerning centrifugal pumps?（）
A.They are particularly suited for pumping high viscosity fluids
B.They are started with the discharge valve opened
C.The flow of liquid is developed by imparting energy due to the rotation of an impeller
D.They are always mounted in a horizontal position
单项选择题
In a vapor compression refrigeration the evaporating pressure is maintained constant by the action of the （）, which removes vapor from the evaporator at the same rate at which it is formed.
A.evaporator
B.compressor
C.condenser
D.none of the above
单项选择题
The percentage of impurities in a specific fuel oil sample is determined by （）.
A.settling in a fuel tank
B.testing in a laboratory centrifuge
C.burning in a calorimeter
D.testing in a closed cup
单项选择题
The tendency of a flammable liquid to vaporize is indicated by its （）.
A.ignition temperature
B.flash point
C.flammable range
D.convection index
单项选择题
In （） pumps a closed discharge valve will cause bursting discharge pressure.
A.centrifugal
B.plunger
C.injector
D.water
单项选择题
WHR stands for （）.
A.Water Head Register
B.Water Heater Re-circulating
C.Waste Heat Recovery
D.Waste Handle Reference
单项选择题
The amount of fluid delivered by a gear pump can be regulated by （）.
A.throttling the pressure line
B.changing the speed of the rotor
C.either A or B
D.None of the above is true
单项选择题
Large pipes or down-comers are fitted between the steam drum and （） to ensure good natural circulation of water.
A.fire-tubes
B.furnaces
C.water drums
D.water wall tubes
单项选择题
（） is the circulation and refreshing of the air in a space without necessarily a change of temperature.
A.Refrigeration
B.Air conditioning
C.Ventilation
D.Heating
单项选择题
When the steering gear is in operation, you should （）.
A.check hydraulic oil levels every hour
B.check the rams for overheating
C.check for excessive oil leakage from rams
D.drain water from telemotor cylinders each watch