How does the mass flow ratio of NH3 compare to Freon-12 under identical refrigeration load and temperature conditions___________________?
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Answer: B. 1 : 9
Explanation
Ammonia has a much higher latent heat of vaporization compared to Freon-12 under identical conditions. Higher latent heat means less mass flow rate of ammonia is needed for the same cooling load. This distinct thermodynamic property creates a mass flow ratio of approximately 1 to 9. Latent heat of vaporization determines how much heat a kilogram of refrigerant can absorb. Ammonia possesses one of the highest latent heat capacities among common commercial refrigerants. Freon-12 requires a much larger circulating mass to achieve equivalent thermal refrigeration capacity.
Industrial ammonia systems use smaller pipe diameters due to the lower mass flow requirements. Comparing refrigerant properties helps engineers select appropriate pipe sizes and compressor displacements. Ammonia high efficiency makes it popular for large industrial cold storage and ice plants. One to one ratio implies identical latent heat capacities, which contradicts actual refrigerant data. Nine to one reverses the actual mass flow ratio relationship between ammonia and Freon-12. Other ratios such as 1 to 3 or 3 to 1 do not match experimental thermodynamic values.
- Subject
- Engineering
- Category
- Mechanical Engineering
- Topic
- —
- Difficulty
- medium
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