單項(xiàng)選擇題Routine maintenance on a Central Control Room hermetically sealed air conditioning unit should include （）

A.changing the air filter
B.recharging the system
C.changing compressor lubricant
D.renewing container vacuum


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1.單項(xiàng)選擇題In an air conditioning system, moisture is removed from the air by（）

A.filers
B.separators
C.ducted traps
D.dehumidifiers

2.單項(xiàng)選擇題A lower thermostatic temperature setting will provide a desired degree of comfort in a room where （）

A.low relative humidity is maintained
B.triple banded squirrel cage fans are used
C.air circulation is a maximum
D.high relative humidity is maintained

3.單項(xiàng)選擇題To prevent the unnecessary loading of an air conditioning system while maintaining the designed dry bulb temperature and relative humidity in an air conditioning system, you should （）

A.admit only enough fresh outside air to provide proper ventilation
B.reduce the air reheating system load
C.lower the compressor head pressure
D.operate the purge recovery unit continuously

4.單項(xiàng)選擇題To add refrigerant to the low side of an air conditioning system, the refrigerant should be introduced through the （）

A.suction service valve as a vapor
B.suction service valve as a liquid
C.discharge service valve as a vapor
D.charging valve as a liquid

5.單項(xiàng)選擇題Which of the fluids listed is normally used to condense the primary refrigerant in a shipboard central air conditioning system?（）

A.Air or Nitrogen
B.Seawater or Fresh water
C.Sodium Nitrate brine
D.Calcium Sulfate brine