A.reciprocating pump
B.positive displacement pump
C.centrifugal pump
D.centripetal pump
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A.remain constant along the tubes length
B.be greatest in a single pass counter flow heat exchanger
C.remain constant throughout the heat exchanger
D.vary from section to section through out the heat exchanger
A.suction pressure only
B.head pressure only
C.superheat only
D.suction pressure and box temperature
A.microscopic steel shavings
B.abrasive waste
C.anti-oxidant compounds
D.oxidation by-products
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
A.eliminate hot air from the condenser
B.maintain steady pressure in a system
C.heat, or cool one fluid by means of another fluid
D.reduce the engine room temperature in tropical climates
A.increase the amount of cooling water to the condenser
B.decrease the amount of cooling water to the condenser
C.add more refrigerant to the system
D.remove some refrigerant from the system
A.Cross
B.Parallel
C.Counter
D.Circular
A.insufficient condenser cooling water
B.excessive condenser cooling water
C.air in the refrigeration system
D.excessive refrigerant in the system
A.Centrifugal
B.Reciprocating
C.Gear
D.Rotary
A.Thermal expansion valve frozen open
B.Suction gas heat exchanger bypassed
C.Condenser clogged or fouled
D.High pressure cutout switch inoperative
最新試題
If the thermal bulb of an expansion valve is incorrectly placed at the center of the coil instead of the end, it will （）.
Which of the problems listed would came the discharge temperature of an R-12 refrigeration compressor to increase?（）
A salinity indicator is used to determine the （）.
The rate of heat transfer between the hot and cold fluids passing through a shell-and-tube type heat exchanger will （）.
A gradual decrease in the discharge pressure of an operating hydraulic pump can be caused by （）.
When the steering gear is in operation, you should （）.
The temperature differential occurring between the inlet temperature of the fluid to be cooled and the outlet temperature of the cooling medium in a shell-and-tube heat exchanger is greatest in which of the flow designs listed?（）
Who is responsible for ensuring that someone is assigned to close the watertight doors in an emergency?（）
The major source of chemical contaminants in hydraulic fluid is （）.
If the viscosity of the liquid being transferred remains constant as the discharge pressure increases, the rotary pump （）.