In a standard vapor compression refrigeration cycle, the rate of refrigerant flow is regulated by___________________?
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Answer: D. expansion valve
Explanation
The expansion valve regulates the flow rate of liquid refrigerant entering the evaporator in a vapor compression cycle. By creating a controlled pressure drop, this device meters the exact mass flow required to match cooling loads. Proper refrigerant metering prevents liquid slugging in the compressor while ensuring complete evaporation inside coils. Vapor compression refrigeration relies on four primary components including compressors, condensers, expansion valves, and evaporators. Thermostatic expansion valves sense evaporator exit temperature to dynamically adjust refrigerant flow rates. Throttling through the valve drops high-pressure liquid down to low-pressure saturation conditions instantly.
Commercial air conditioning systems depend on accurate refrigerant regulation to maintain comfortable indoor temperature and humidity. Faulty expansion valves lead to erratic cooling performance, frozen evaporator coils, and potential compressor damage. HVAC technicians calibrate expansion valves carefully during commissioning to optimize coefficient of performance values. The compressor circulates refrigerant vapor through the system and raises its pressure and temperature. The condenser rejects heat from high-pressure refrigerant vapor to the ambient cooling medium or atmosphere. The evaporator absorbs heat from the refrigerated space by boiling low-pressure liquid refrigerant inside tubes.
- Subject
- Engineering
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- Mechanical Engineering
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- —
- Difficulty
- medium
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