A.molecular fluid vibration
B.energy losses
C.wide pressure variations
D.mechanical damage to control valves
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A.Keeps the refrigerated space cooler
B.Reduces the efficiency of the plant
C.Takes the load off the compressor
D.Has no affect on the system
A.proportional band
B.the error signal
C.the reset signal
D.feedback
A.Dehydrators must be used continuously in a refrigeration system
B.A 25 ton refrigeration system has the same cooling effect as melting 25 tons of ice in 24 hours
C.A thermostatic expansion valve is used to control refrigerated space temperature
D.The liquid receiver functions to collect and remove non- condensable gases
A.Hydraulic
B.Mechanical
C.Pneumatic
D.Electrical
A.Energy can be created or destroyed
B.Energy may not be transformed
C.The total quantity of energy in the universe is always the same
D.None of the above
最新試題
An increasing head pressure in a refrigeration system, without any corresponding change in the cooling water inlet temperature, would probably be caused by （）.
If the viscosity of the liquid being transferred remains constant as the discharge pressure increases, the rotary pump （）.
An internal bypass is provided on some hydraulic system suction strainers to help reduce the possibility of （）.
A gradual decrease in the discharge pressure of an operating hydraulic pump can be caused by （）.
A salinity indicator is used to determine the （）.
Which of the following problems could cause the high pressure cutout switch to shut down the compressor in a refrigeration system?（）
The general purpose of a heat exchanger is to （）.
Thermostatic expansion valves can be adjusted for （）.
Who is responsible for ensuring that someone is assigned to close the watertight doors in an emergency?（）
On tank vessels equipped with power operated cargo tank valves, the type of power operator most commonly used is （）.