Combustion Temperatures

Abstract

The molar balance data of chapter 5 permitted the derivation of equilibrium product composition at any selected temperature, which might be sustained artificially by the extraction or supply of energy in some form. In combination with the energy-balance data of chapter 6, it now becomes possible to determine the temperature achieved naturally by the combustion products under any specified conditions. Assuming no external addition from the environment, the maximum value of this temperature is reached when no energy losses occur through work or heat transfers to the environment, that is, under isochoric adiabatic conditions in the non-flow case, and isobaric adiabatic conditions in steady flow. Once again, in view of the many applications of constant-pressure steady flow in furnaces, continuous-flow engines and chemical processing generally, the following treatment is based on enthalpy, with the symbol T_{p ad} representing isobaric adiabatic combustion temperature. However, comparable arguments apply to internal energy and T_{V ad} for the iso-choric adiabatic combustion temperature in such applications as the spark-ignition piston engine.