The presence of moisture in a refrigerant interferes with the operation of___________________?
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Answer: D. expansion valve
Explanation
Moisture in a refrigerant can freeze at the expansion valve orifice, clogging it and disrupting the flow of refrigerant. When liquid refrigerant throttles through the valve, the temperature drops below freezing, turning dissolved moisture into ice crystals. This ice blockage starves the evaporator of refrigerant, causing immediate loss of cooling capacity and erratic pressures. Refrigerant systems must maintain extreme dryness, measured in parts per million of water vapor content. Filter-driers containing desiccants like molecular sieve are installed in liquid lines to absorb residual moisture. Chemical reactions between moisture, refrigerants, and compressor oils can also produce corrosive hydrofluoric acids.
The compressor handles gas flow but is not the primary location where moisture freezes to form flow blockages. The condenser operates at high temperatures and pressures where ice crystal formation is thermodynamically impossible. While moisture affects overall heat transfer, the specific mechanical interference occurs directly at the expansion valve.
- Subject
- Engineering
- Category
- Mechanical Engineering
- Topic
- —
- Difficulty
- medium
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