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Flash calculations
Posted:
20 July 2022, 15:23by Stephan
I have a flash unit operation in a testfile.
When I run it, the liquid outlet has a higher water flow than the condensed portion of the water in the inlet stream.
How can that be?
See attached file.
Re: Flash calculations
Posted:
20 July 2022, 16:35by jasper
The document you posted seems to only contain compressor units - can you check whether you attached the right document?
Re: Flash calculations
Posted:
21 July 2022, 07:10by Stephan
Indeed, I atached the wrong file. Here is the right one.
Re: Flash calculations
Posted:
21 July 2022, 08:49by jasper
At 1.634999 bar and 78 C, water is liquid. The vapor pressure for water at 78 C is 0.43703103 bar.
However, mix it with enough air and enough water goes into the vapor phase. Your vapor molar flow rate is 16.5x higher than your liquid molar flow rate. Water mole fraction in the vapor phase is roughly 27%, which, from a quick google search (
https://www.engineeringtoolbox.com/maxi ... _1403.html) is not unreasonable?
Re: Flash calculations
Posted:
21 July 2022, 11:47by Stephan
Indeed, I was wrong.
I just misinterpreted the stream informations.
The flash unit behaves as it should.
Re: Flash calculations
Posted:
21 July 2022, 14:46by jasper
Glad to hear your issue is resolved.