单项选择题
To obtain maximum efficiency, two stage air compressors are usually ().
A.horizontally mounted
B.never fitted with intake filters
C.fitted with intercoolers
D.operated in an unloaded condition at all times
相关考题
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单项选择题
Which of the following statements is true concerning the overall efficiency of air compressors?()
A.High pressure compressors are more efficient than low pressure compressors
B.Mechanical efficiency divided by compressor efficiency will equal the overall efficiency of the compressor unit
C.Two stage compressors are generally more efficient than single stage compressors
D.The volumetric efficiency is decreased in multistage compressors -
单项选择题
The ability of an oil to separate cleanly from an oil and water mixture is referred to as its ().
A.precipitation number
B.neutralization number
C.pour point
D.demulsibility -
单项选择题
When the relief valve opens it discharges high pressure refrigerant vapor to the ().
A.liquid strainer
B.refrigerant inlet of the condenser
C.inlet side of the evaporator
D.suction side of the compressor
