How Do You Calculate Enthalpy with Ammonia's Dryness Fraction at -10C?

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To calculate the enthalpy of ammonia (R717) at a saturation temperature of -10°C with a dryness fraction of 0.9, one must refer to the ammonia properties table. The dryness fraction represents the ratio of vapor mass to the total mass in a saturated mixture, indicating the quality of the refrigerant. It is distinct from water content and does not imply the presence of ammonium hydroxide. Understanding this concept is crucial for accurate thermodynamic calculations. Utilizing the properties table will yield the necessary enthalpy value for the specified conditions.
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With the use of Ammonia (R717) properties table, find the enthalpy of the refrigerant if the saturation temperature is -10C and the dryness fraction, x, is 0.9.

can anyone help me with this? i do not understand the use of dryness fraction
Many thanks!
 
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Check one's text, but if 'dryness' is like steam quality, then it refers to the fraction of a saturated two phase system which is gas (vapor), as opposed to the other fraction which is liquid.

I assume dryness does not refer to the water content, which would lead to ammonium hydroxide, or 'aqua' ammonia.

This might be of interest - http://www.tannerind.com/anhydrous-ammonia.html

http://www.iifiir.org/en/doc/1055.pdf
 
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rubberduckie said:
With the use of Ammonia (R717) properties table, find the enthalpy of the refrigerant if the saturation temperature is -10C and the dryness fraction, x, is 0.9.

can anyone help me with this? i do not understand the use of dryness fraction
Many thanks!

The dryness fraction is just another term in thermodynamics for quality. It's equal to the mass of the vapor phase of the substance divided by the total mass of the substance.

Hope that helps.

CS
 
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