freeze on the expansion valve seat and reduce the flow of liquid refrigerant
emulsify the oil in the condenser
freeze in the king valve
clog the oil trap
第1题：
If the superheat value of a thermostatic expansion valve is set too low, the _.
A.the suction line will be abnormally cold and liquid may slug back to the compressor
B.the suction line will be hot due to a reduced amount of refrigerant returning to the compressor
C.the temperature of the refrigerant within the condenser will remain the same
D.the temperature of the refrigerant passing through the sub-cooler will decrease
第2题：
Sludge may be formed in the oil in the crankcase of a reciprocating air conditioning compressor as a result of ______.
A.refrigerant bubbles in the lube oil
B.refrigerant reducing the lube oil viscosity
C.oxidation(氧化) of the lube oil from overheating
D.reducing the floc or cloud point of the oil
第3题：
Moisture is removed from a refrigeration system by
A.bleeding refrigerant from the condenser
B.opening a drain petcock on the oil separator
C.condensing the water in the heat exchanger
D.using a dehydrator cartridge
第4题：
high discharge pressure
frosting of the crankcase
high temperature of the overboard water
low suction pressure of compressor
第5题：
above
below
equal to
uncertain
第6题：
In a chilled(冷的) water air conditioning unit using a reciprocating compressor, the refrigerating effect of the primary refrigerant can be increased by ______.
A.increasing refrigerant pressure in the coil
B.increasing chilled water flow through the cooler
C.sub-cooling the refrigerant in the condenser
D.superheating the refrigerant in the compressor
第7题：
The moisture equilibrium chart can be used to determine the ______．
A.Absolute moisture content of the air surrounding a hygroscopic cargo when moisture equilibrium exists
B.Dew point temperature that the air surrounding a hygroscopic commodity will have when in moisture equilibrium with that commodity
C.Enthalpy of the air surrounding a hydroscopic cargo which is in moisture equilibrium with the cargo
D.Temperature at which moisture equilibrium will occur in a cargo hold containing a hygroscopic cargo
第8题：
If the refrigeration compressor crankcase is sweating, the cause may be due to
A.a shortage of refrigerant
B.the compressor running continuously
C.liquid refrigerant returning to the compressor
D.the compressor short cycling on the high pressure cutout
第9题：
liquid
oily mixture
emulsion
vapor
第10题：
too much refrigerant in the system
oil entrained in the refrigerant
less than a full charge of refrigerant in the system
ice crystals forming in the refrigerant