Refrigeration Systems and Heat Transfer Flashcards
7 cards from real ASF 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 Systems and Heat Transfer flashcards as text
What is the primary function of a refrigerant in a cooling system?
Answer: To absorb heat from the refrigerated space and release it outside
Refrigerant absorbs heat in the evaporator and releases it in the condenser, effectively transferring heat out of the refrigerated space.
In a refrigeration cycle, where does the refrigerant absorb heat from the surrounding environment?
Answer: Evaporator
The evaporator is the component where the refrigerant absorbs heat from the surrounding air or food, causing it to evaporate into a gas.
What is the primary role of the compressor in a refrigeration system?
Answer: To increase the pressure and temperature of the refrigerant vapor
The compressor raises the pressure and temperature of the refrigerant vapor so it can effectively release heat in the condenser.
What happens to refrigerant as it passes through the expansion valve?
Answer: Its pressure and temperature decrease rapidly
As refrigerant passes through the expansion valve, its pressure and temperature drop rapidly, preparing it to absorb heat in the evaporator.
Which refrigerant is commonly used in modern household refrigerators due to its low global warming potential?
Answer: R-600a (isobutane)
R-600a (isobutane) has a very low global warming potential and is widely used in modern energy-efficient household refrigerators as an eco-friendly alternative.
What is 'superheat' in the context of a refrigeration system?
Answer: The additional heat in refrigerant vapor above its saturation temperature at a given pressure
Superheat is the additional temperature above the boiling point of the refrigerant at a given pressure, ensuring only vapor enters the compressor to prevent damage.
What is 'subcooling' in a refrigeration system?
Answer: Cooling liquid refrigerant below its condensing saturation temperature
Subcooling is the process of cooling liquid refrigerant below its saturation temperature after the condenser, which improves system efficiency and prevents flash gas.