Refrigeration Fundamentals & System Components Flashcards
7 cards from real RSES 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 Fundamentals & System Components flashcards as text
A reciprocating compressor with leaking discharge valves will most likely exhibit:
Answer: Lower than normal discharge pressure and reduced capacity
Leaking discharge valves allow compressed gas to flow back into the cylinder, reducing compression efficiency and lowering discharge pressure and system capacity.
The term 'flooding back' in a refrigeration system describes:
Answer: Liquid refrigerant returning to the compressor through the suction line
Flooding back occurs when liquid refrigerant travels through the suction line to the compressor, risking hydraulic damage and oil dilution.
What is the purpose of a crankcase heater on a refrigeration compressor?
Answer: Prevent refrigerant migration into the oil during off-cycle
Crankcase heaters keep the oil warm during off-cycles to prevent refrigerant from migrating into and dissolving in the crankcase oil.
In an evaporative condenser, heat is primarily rejected by:
Answer: Latent heat of evaporation of water sprayed over the coil
Evaporative condensers reject heat mainly through the latent heat of water evaporation, making them more efficient than dry air-cooled condensers.
Which of the following best describes 'approach temperature' for a water-cooled condenser?
Answer: Temperature difference between condensing refrigerant and leaving water
Approach temperature is the difference between the refrigerant condensing temperature and the leaving condenser water temperature, indicating heat exchanger efficiency.
A scroll compressor differs from a reciprocating compressor in that it:
Answer: Uses two interleaving spiral scrolls without intake and discharge valves
Scroll compressors use two meshing spiral scrolls to trap and compress refrigerant, eliminating the need for suction and discharge valves.
Non-condensable gases (such as air) trapped in a refrigeration system will cause:
Answer: Higher than normal discharge pressure and reduced efficiency
Non-condensables occupy condenser volume and add to total discharge pressure without contributing to refrigerating effect, reducing system efficiency.