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单项选择题
A.remove any air that may accumulate in the system
B.take out unpleasant fumes from the refrigerant
C.vent off excess refrigerant in an emergency
D.permit opening the refrigerating system for cleaning and inspecting
单项选择题
A.to increase the system efficiency by sensible heat transfer
B.to stop the liquid from flashing
C.to reduce the load on the compressor
D.to remove latent heat of vaporization and the suction piping transfer
单项选择题
A.its pressure and temperature are both lowered
B.its pressure and temperature are both raised
C.its pressure is lowered and its temperature is raised
D.its pressure is raised and its temperature is lowered
单项选择题
A.thermal valve
B.magnetic stop valve
C.bellows valve
D.bimetallic valve
单项选择题
A.high-pressure cutout switch is jammed open
B.low-pressure switch is jammed shut
C.thermal bulb is not operating properly
D.scale trap is clogged
单项选择题
A.in the middle of evaporator coils
B.near the evaporator coil outlet
C.near the evaporator coil inlet
D.on the bottom row of evaporator coils
单项选择题
A.amount of superheat in the vapor leaving the coil
B.amount of superheat in the liquid
C.temperature in the evaporator coils
D.pressure in the evaporator coils
单项选择题
A.stop the refrigerant from flowing
B.force the refrigerant to flow
C.cause the refrigerant pressure to rise
D.cause the refrigerant pressure to fall
单项选择题
A.the expansion valve will move toward the wide open position
B.the expansion valve will move toward the closing position
C.the feeler bulb will conveys the high temperature
D.the superheat degree will raise
单项选择题
A.move in an opening direction
B.move in a closing direction
C.either open or close
D.not move at all