Question 128Refrigeration/AC - 1st Asst/Chief70% to pass
Constant superheat is maintained at the evaporator coil outlet of a refrigeration system or unit by the action of what device?
AI Explanation
The correct answer is C) thermal expansion valve.
The thermal expansion valve is responsible for maintaining constant superheat at the evaporator coil outlet of a refrigeration system. It does this by automatically adjusting the flow of refrigerant into the evaporator based on the temperature and pressure changes in the system. As the refrigerant evaporates in the coil, the thermal expansion valve senses the resulting superheat and adjusts the refrigerant flow accordingly to keep the superheat at a constant level.
The other options are incorrect because: A) a king valve is used to isolate a compressor, B) a low-pressure cutout switch shuts down the system at low pressure, and D) a solenoid valve opens and closes to control refrigerant flow, but does not maintain constant superheat.
Related Questions
#126 When the sensing bulb of a thermostatic expansion valve is charged with a fluid different from the charge used in the system, what name of the charge is associated with the power element? #127 Which of the following illustrated thermal expansion valves would be appropriate to use on an evaporator coil with a 2 psi pressure drop, where externally adjustable superheat and a replaceable power element are both desired? Illustration GS-RA-06 #129 Refrigerant flow through a thermostatic expansion valve is greatest under what conditions? #130 In refrigeration systems with multiple evaporators, the metering of refrigerant to each refrigerated space evaporator is accomplished by what device? #131 When a refrigeration compressor is in the 'off' cycle, the thermal expansion valve will react in what way?