Refrigeration Systems & Components Flashcards
7 cards from real CRST 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 & Components flashcards as text
What condition is indicated when frost forms uniformly across the entire evaporator coil?
Answer: Normal operation with adequate airflow
Uniform frost across the full coil typically indicates normal operation with proper refrigerant flow and adequate airflow.
A brazed-plate heat exchanger used as an evaporator offers which advantage over a shell-and-tube evaporator?
Answer: Compact size with high heat transfer efficiency
Brazed-plate heat exchangers provide very high surface area-to-volume ratios, offering superior heat transfer in a compact package.
What is the effect of non-condensable gases on condenser performance?
Answer: They raise condensing pressure and reduce efficiency
Non-condensable gases (air, nitrogen) blanket condenser tubes, raising head pressure and reducing heat transfer efficiency.
A scroll compressor produces a rattling noise on startup. What is the most likely cause?
Answer: Reverse rotation of the compressor
Scroll compressors are rotation-sensitive; reverse rotation causes the scrolls to separate and produces a characteristic rattling or grinding noise.
What is the function of a hot gas bypass valve in a refrigeration system?
Answer: Maintain minimum evaporator pressure during light loads
A hot gas bypass valve routes hot discharge gas to the low side to maintain minimum evaporator pressure and prevent coil freeze-up at light loads.
Which component in a refrigeration system is specifically designed to separate oil from refrigerant vapor on the high-pressure side?
Answer: Oil separator
An oil separator is installed in the discharge line to capture oil before it enters the condenser, returning it directly to the compressor crankcase.
In a parallel rack refrigeration system used in supermarkets, what is the main advantage over individual compressor systems?
Answer: Redundancy and shared capacity allowing better load management
Parallel rack systems allow multiple compressors to share load, providing redundancy so that one compressor failure does not shut down the entire system.