1 reply to this topic

[Sherif Morsi]

Hi,

 

I calculated the total heat resulting from firing FG in a process heater by multiplying the total gas flow by the LHV of the gas

LHV = 949 Btu/SCF

Flow = 115,000 SCFH

 

Q1 = 109.14 MMBtu/hr

 

I also pulled out the capacity curve of the burners and at 11 psig gas pressure, the heat release per burner is 9 MMBtu/hr.

Q2 = 23 burners x 9MMBtu/hr = 207 MMBtu/hr

 

If I am not mistaken, capacity curves are for a specific gas composition and properties.

 

Why is there such a big difference between the two calculated values given that I am using the same gas properties? P.S: The FG Mol wt is 18 in the datasheet vs. actual Mol wt of 17.6 for the current FG used.

 

Thanks

Sherif

[breizh]

https://books.google... burner&f=false

 

Hi Sherif,

 

Consider the link above , better If you have a chance let you find this book (reference below) 

 

The John Zink Hamworthy Combustion Handbook: Volume 1 - Fundamentals

 

 Note : I found a value of HR # 4 MMBtu/h for methane at the # 11psig. Should not be very different from your gas specification ?  LHV # 910 BTU/scf .

 

Probably good to review your data .

My 2 cents

 

Breizh 

Edited by breizh, 03 November 2019 - 12:31 AM.