Dryness Fraction question

  1. 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!
     
  2. jcsd
  3. Astronuc

    Staff: Mentor

    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
     
    Last edited: Jun 3, 2008
  4. stewartcs

    stewartcs 2,284
    Science Advisor

    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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