Thermodynamics Question. Determine Quality of Two Phase Ammonia.

[kdhutchi]

I have attached a copy of my homework paper to this post. I'm fairly certain the answers are not correct. The quality for both parts is 1.00. In addition, the quality increases (to the fourth decimal place) in the 0.0 degree Fahrenheit sample. I'd expect the quality to go down due to less heat energy leading to less vapor. The specific volume values were obtained from my textbook's appendices titled: Properties of Saturated Ammonia (Liquid Vapor).

Also, I tried attaching just the document, but received the "invalid File" remark. I was hoping to just attach the doc to ease replies. Editing the document would be easier than a full fledged post! I'm using 2010 if that helps.

 

[edgepflow]

Your formula is correct but your ammonia properties and units are incorrect.

Units should be volume / mass, like the total specific volume they provided.

Also, as a check: vg / vf is about equal to 50 for ammonia in this range. Your values are much higher.

Check again your ammonia property tables.