Propagation and Extinction Studies of Laminar Lean Premixed Syngas/Air Flames

This thesis presents pioneering experimental and numerical studies on three aspects of the combustion characteristics of lean premixed syngas/air flames, namely the laminar flame speed, extinction limit and flammability limit. It illustrates a new extinction exponent concept, which enriches the combustion theory.

Above all, the book provides the following: a) a series of carefully measured data and theoretical analyses to reveal the intrinsic mechanisms of the fuel composition effect on the propagation and extinction of lean syngas/air flames; b) a mixing model and correlation to predict the laminar flame speed of multi-component syngas fuels, intended for engineering computations; c) a new extinction exponent concept to describe the critical effects of chemical kinetics on the extinction of lean premixed syngas/air flames; and d) the effects and mechanism of the dilution of incombustible components on lean premixed syngas/air flames and the preferential importance among the thermal, chemical and diffusion effects.

Nominated as an outstanding thesis by Tsinghua University Presents new flame speed and extinction data covering a wide range of experimental conditions Provides insights and interpretations that explore and reveal the internal mechanisms Illustrates a new extinction exponent concept, which enriches the combustion theory Offers a simple but effective model of syngas flame speed for engineering applications

Inhalt
Introduction.- Experimental Approach 35.- Numerical Approach.- Laminar flame speed of lean premixed H2/CO/air flames 71.- Extinction limit of lean premixed H2/CO/air flames.- Lower flammability limit of H2/CO mixtures.- Dilution effect on the propagation and extinction of lean premixed syngas/air flames 139.- Conclusion and recommendation.- Nomenclature.