轮机英语船舶辅助机械章节练习(2018.01.05)

单项选择题
Water level controllers of the boiler must be kept operable to protect external steam-using plant from water “（）” danger.
A.carry off
B.carry down
C.carry on
D.carry over
单项选择题
Which of the following pumps will build up a bursting pressure or stall their motors if the discharge valves are closed?（）(1) gear(2) centrifugal(3) screw
A.（1）and（2）
B.（1），（2）and（3）
C.（1）and（3）
D.（2）and（3）
单项选择题
The energy associated with molecules is known as （）.
A.kinetic energy
B.potential energy
C.mechanical energy
D.thermal energy
单项选择题
If one hydraulic pump of an electro-hydraulic steering unit falls, the vessels steering can be initially and best maintained by using the （）.
A.trick wheel
B.accumulator
C.standby pump
D.telemotor
单项选择题
The primary reason low pressure evaporators produce distillate more efficiently, and with less scale formation, than high pressure evaporators is （）.
A.evaporation is accomplished in a vacuum
B.due to the higher temperature of the incoming feed
C.due to the latent heat of evaporation principle
D.evaporation in a submerged medium produces more distillate
单项选择题
Which pump installation would require an external source of sealing water?（）
A.Main circulator pump jacket water cooling
B.Salt water service pump
C.Auxiliary condensate pump
D.Bilge pump
单项选择题
Which of the following best describes “overcharge of refrigerant”?（）
A.Too much refrigerant
B.Too little refrigerant
C.Refrigerant is ran out
D.Running is over
单项选择题
In the refrigeration system, a shortage of refrigerant is indicated by （）.
A.the compressor short cycling on high pressure cut out switch
B.high suction pressure
C.high head pressure
D.bubbles in the sight glass
单项选择题
The gear and screw pumps are classified as （）.
A.variable stroke pumps
B.multistage pumps
C.positive displacement pumps
D.triple-ported pumps
单项选择题
Which of the listed operating conditions would have the greatest effect on the volumetric efficiency of an operating reciprocating air compressor?（）
A.The density of the air entering the compressor
B.The temperature of the air entering the compressor
C.The designed rotating speed of the compressor
D.A leaking head gasket