Flue gas temperature calculation
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I would like to ask the experts: How can the flue gas temperature after complete combustion of a fuel gas with a composition of 50% CH4, 10% H2, 20% CO, and 20% N2 be calculated? Thank you!
The conditions provided by the poster are incomplete; at least the following data are needed to carry out an accurate calculation: 1. Fuel gas pressure and temperature； 2. Pressure, temperature, etc. during combustion ； 3. Is it adiabatic combustion? 4. Composition, quantity, temperature, pressure, etc., of the oxidizing agent (air or oxygen).
Take a look at this: http://bbs.hcbbs.com/viewthread.php?tid=324867
1. Fuel gas pressure: 3.0 MPa; Temperature: 32 degrees Celsius； 2. Pressure, temperature, etc. during combustion ； Pressure during combustion: 2.5 MPa; Temperature: 80 degrees Celsius ； 3. Is it adiabatic combustion? Yes, 4: the composition, amount, temperature, pressure, etc. of the oxidizing agent (air or oxygen). Oxidizer: Air ； complete combustion ； Temperature: 32 degrees Celsius, pressure: 3.0 MPa. May I ask: are these conditions sufficient?
It’s not enough yet; is there exactly enough oxygen to burn CH4, H2, and CO, or is there a certain excess factor? Normally, there is an excess coefficient for oxygen. If all these data are available, the original poster can first perform a material balance based on those conditions, and then carry out a heat balance, thereby enabling the calculations to be done. This post was last edited by mfjxg on 2009-2-5 15:14]
Excess coefficient of oxygen: 1.6 Thank you! I will calculate it based on your instructions.
Only the fuel components are not sufficient; an oxidizer and a combustion environment are also needed, as well as information on whether combustion occurs stably and on energy losses. These aspects are explained in greater detail in the principles of boilers
While doing my calculations, I encountered the need to use the specific heat at constant pressure. However, the values available in the literature are all for constant pressure conditions; although there are correction factors for increased pressure, in practice some of the adiabatic temperatures Tr and adiabatic pressures Pr fall outside the range for which such values are available. I would like to ask experts: how can one find or calculate the specific heat at constant pressure in such cases? Can it be calculated using enthalpy values? Looking forward to it! ! ! ! !