Need Help energy calculations. 3

[Sideliner]

NEED: FREE Energy (GIBBS)? or Specific Energy for
gasoline in kcal/mole or energy/unit.

Can you bright minds help me out please. Years ago
in College we did a combustion calculation appx. like
the following. The latent heat (heat contained at start of process) of reactants were combined with the specific heat of reaction to products. This total heat of reaction plus
the starting heat was devided among the mass of the products
to determine the theoretical combustion temperature of the products. I may have gotten the terms and the method slightly wrong, so please do straighten me out. I realize that this whole calculation is complicated by a cycle of compression and decompression. So, what's the situation?
Sideliner (met.) PLease,Please.

 

[GregLocock]

Higher calorific value of gasoline is 43 MJ/kg

Cheers

Greg Locock

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.

 

[j2bprometheus]

Hi- Do you want to calculate the flame temperature for some situation? This is usually referred to as the adiabatic flame temperature. Look in the index of a thermodynamics book for "adiabatic flame temperature" or for "flame temperature". The key idea is the that enthalpy of the products equals the enthalpy of the reactants.
John B. Heywood's book on IC engines gives some convenient tables and polynomial fits for enthalpies, heating values, etc.
I normally use EQUIL (which is part of CHEMKIN) to calculate flame temperatures for natural gas type fuels.

 

[Sideliner]

Dear Mr. j2bprometheus,

Yes, I do want to calc. flame temp. for some situation.
Ohhhhhhhh, I am like sooo way past the times. I'm screwing around with the system so that regular adiabatic tables just won't do. And, it isn't an isothermal calculation either. As a cetified fossil for all to see, may I please ask what is EQUIL and CHEMKIN? Software? Thanks! Sideliner

 

[quark]

Check this thread610-50077

 

[j2bprometheus]

Mr. Sideliner- EQUIL and CHEMKIN are computer programs. They are now commercially available. We have old versions that were freeware from Sandia National Lab. Sorry for the slow response.
C.R. Ferguson wrote book with some fortran routines for calculating equilibrium temperature. See Ferguson, C. R., 1986, "Internal Combustion Engines", Wiley. Do a search for the terms "farg", "ECP", and Ferguson and you will some info on them. They make it easy to calculate an adiabatic flame temperature, if you have a FORTRAN compiler.

 

[Sideliner]

Dear Friends,

You guys are great!Thanks to you and Eng-Tips!
I'll do some "figurin," scratch both ends, and
let you finally know what I am up to doing. Give
me at least a month.
Sideliner