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单项选择题
A.microscopic steel shavings
B.abrasive waste
C.anti-oxidant compounds
D.oxidation by-products
单项选择题
A.increase the capacity of the coil
B.increase the superheat at the bulb
C.deliver more refrigerant to the coil
D.decrease the capacity of the coil
单项选择题
A.Centrifugal
B.Reciprocating
C.Gear
D.Rotary
单项选择题
A.a high suction head
B.rotating rings
C.badly worn bearings
D.a loose stuffing box gland
单项选择题
A.solenoid valve to seize
B.compressor to hunt
C.formation of flash gas in the liquid line
D.expansion valve to freeze open
单项选择题
A.insufficient condenser cooling water
B.excessive condenser cooling water
C.air in the refrigeration system
D.excessive refrigerant in the system
单项选择题
A.Thermal expansion valve frozen open
B.Suction gas heat exchanger bypassed
C.Condenser clogged or fouled
D.High pressure cutout switch inoperative
单项选择题
A.noise and vibration
B.an increase in discharge pressure
C.an increase in suction pressure
D.lifting of the relief valve
单项选择题
A.insufficient cooling water flow to the condenser
B.a low refrigerant charge in the system
C.the liquid valve is open too much
D.high evaporator superheat
单项选择题
A.dead band action
B.neutral zone action
C.range
D.on-off action