NCEES 2008 # 129

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tmacier

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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

Sample_Problem_129.JPG

 
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?

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

 
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THanks - got it-

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

 
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!

 
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Yes, you use the h values at ATM in the quality equation because they say it's withdrawn at that pressure.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.

 
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