A.Energy can be created or destroyed
B.Energy may not be transformed
C.The total quantity of energy in the universe is always the same
D.None of the above
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A.evaporator
B.compressor
C.expansion valve
D.condenser
A.has continuously for a long period
B.suction pressure is below normal
C.oil level is below normal
D.starts after a long idle period
A.protect the pump from fine soluble contaminants
B.prevent solid particles from entering the pump
C.prevent solid particles from entering the filter
D.protect the directional control valves
A.Feed-water heater internal tube surfaces
B.Internal distillate cooler tubes
C.Flash chamber vertical surfaces
D.Distilling condenser tubes
A.Reduction of friction
B.Insulation of hot surfaces
C.Lubrication of moving parts
D.Elevation of cooler outlet temperatures
最新試題
Low compressor head pressure in a refrigeration system can be caused by（）.
If you are given the job of adding hydraulic fluid to a mooring winch, and are not certain as to the type of fluid to use, you should （）.
If the head pressure of a reciprocating refrigeration compressor is excessive, （）.
When a refrigeration compressor has developed a high head pressure as a result of a refrigerant overcharge, you should （）.
Heavy wear in a particular area of the inner circumference of a packing ring may be caused by （）.
The output volume of a positive fixed displacement pump can be changed only by （）.
Who is responsible for ensuring that someone is assigned to close the watertight doors in an emergency?（）
A pressure drop through the refrigerant liquid line may cause （）.
The temperature differential occurring between the inlet temperature of the fluid to be cooled and the outlet temperature of the cooling medium in a shell-and-tube heat exchanger is greatest in which of the flow designs listed?（）
A grease gun is generally used to lubricate a （）.