Examine the following statements and choose the correct one?
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Answer: B. If operating temperature of system is low, then refrigerant with low boiling point should be used
Explanation
When a refrigeration system operates at low temperatures, choosing a refrigerant with a correspondingly low boiling point is necessary. The operating evaporator temperature must remain higher than the refrigerant's boiling point to maintain proper heat transfer. Selecting appropriate saturation characteristics ensures the system can absorb heat efficiently from low-temperature cold spaces. Refrigerants undergo phase change inside evaporators by absorbing heat from their surroundings at constant saturation pressure. Atmospheric boiling points dictate the baseline temperature range where a working fluid can function as a refrigerant. Thermodynamic cycles require working fluids whose saturation temperature matches the targeted cooling application requirements.
Refrigerants should possess high latent heat values to maximize heat absorption per unit mass circulated. Precooling and subcooling involve different thermodynamic states and temperature thresholds within the liquid refrigerant line. Superheat adds sensible heat to vapor beyond its saturation temperature, whereas latent heat involves phase change.
- Subject
- Engineering
- Category
- Mechanical Engineering
- Topic
- —
- Difficulty
- medium
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