NCEES 2008 # 129

Started by tmacier , Sep 16 2010 01:54 PM

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6 replies to this topic

#1 tmacier

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Posted 16 September 2010 - 01:54 PM

Working thru problem 129 in the NCEES 2008 study guide.
I must be missing were they obtain 1335.2 BTU/lbm from.
Any guidance would be appreciated.
Thanks
Tim

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#2 tmacier

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Posted 18 September 2010 - 10:43 AM

QUOTE (tmacier @ Sep 16 2010, 09:54 AM) <{POST_SNAPBACK}>

Working thru problem 129 in the NCEES 2008 study guide.
I must be missing were they obtain 1335.2 BTU/lbm from.
Any guidance would be appreciated.
Thanks
Tim

Anyone? Is the 1335 incorrect?

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#3 navyasw02

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Posted 18 September 2010 - 03:16 PM

1335 is correct. App 24.C superheated steam table at 14.696psi at 600F h= 1335.3

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#4 tmacier

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Posted 19 September 2010 - 12:22 PM

THanks - got it-
I appreciate your response - for some foolish reason I could not find that!

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#5 MetsFan

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Posted 12 April 2012 - 09:29 PM

Sorry for bumping such an old thread, but how can you use the h values at 14.7psia? Is it because they withdraw the product at ATM? If they hadn't mentioned that, how would you find the resulting temperature/pressure of the mixture?

Thanks!

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#6 Outlaw44

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Posted 12 April 2012 - 11:17 PM

Sorry for bumping such an old thread, but how can you use the h values at 14.7psia? Is it because they withdraw the product at ATM? If they hadn't mentioned that, how would you find the resulting temperature/pressure of the mixture?

Thanks!

Yes, you use the h values at ATM in the quality equation because they say it's withdrawn at that pressure. To find the quality, you'd have to know the temp or pressure so you can use the hf and hfg at that point from the steam tables.