Refrigeration Cycle Fundamentals Flashcards
7 cards from real CARO practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Refrigeration Cycle Fundamentals flashcards as text
Under normal operating conditions, in what state should refrigerant leave the evaporator?
Answer: Slightly superheated vapor
A small amount of superheat ensures all liquid has boiled off before the vapor reaches the compressor.
What type of heat does refrigerant primarily absorb as it boils in the evaporator?
Answer: Latent heat of vaporization
Boiling is a change of state, so most of the heat absorbed is latent heat of vaporization.
If the pressure in an evaporator is lowered, what happens to the refrigerant's saturation (boiling) temperature?
Answer: It drops
Saturation temperature is directly tied to pressure, so lower pressure means a lower boiling point.
How is liquid subcooling at the condenser outlet calculated?
Answer: Saturated condensing temperature minus actual liquid line temperature
Subcooling is how far the liquid has been cooled below its saturation temperature at condensing pressure.
Refrigerant leaving the compressor discharge is best described as what?
Answer: High-pressure, high-temperature superheated vapor
Compression raises both pressure and temperature, leaving the vapor well superheated.
What two things happen to refrigerant as it passes through the expansion (metering) device?
Answer: Pressure drops and part of the liquid flashes to vapor
The sudden pressure drop causes some liquid to flash, cooling the remaining liquid to evaporator temperature.
One ton of refrigeration equals how many Btu of heat removal over 24 hours?
Answer: 288,000 Btu
A ton is 12,000 Btu/h, which equals 288,000 Btu per 24 hours (the heat to melt one ton of ice).