单项选择题
A.Refrigerator B.Refrigerant C.Cooling medium D.Brine
In a refrigeration plant the （） need defrosting.A.fanB....
单项选择题In a refrigeration plant the （） need defrosting.
A.fan B.compressor C.condenser D.evaporator
Hot gas defrosting uses the hot gas from （） to defrost ...
单项选择题Hot gas defrosting uses the hot gas from （） to defrost the evaporator.
A.starting air bottles B.diesel engines C.boilers D.refrigeration compressors
The evaporating pressure in R22 vapor compression refri...
单项选择题The evaporating pressure in R22 vapor compression refrigeration plant should be （） atmospheric.
A.below B.above C.equal to D.much larger than
