Computation of Adiabatic Flame Temperatures and Other Thermodynamic Quantities

The equilibrium final temperature and composition of a given fuel-oxidizer mixture have both theoretical and practical importance for helping to understand the behavior of combustion systems. Both are needed in order to estimate levels of chemical pollutants such as oxides of nitrogen (NOx), and the final temperature is necessary to predict the expected thermal efficiency and heating value of a giv~n combu~tor. Knowledge of the ways that varlOUS radlcal and stable intermediate chemical species vary as operating conditions are changed can also suggest system modifications to improve overall performance. In this paper, the methods available for computing chemical equilibrium conditions such as adiabatic flame temperatures will be reviewed. The dependence of computed values on available thermochemical data bases will be demonstrated. Examples of equilibrium flame temperatures and compositions for mixtures of interest and importance in natural gas combustion will be presented.