Impacts of the Heating Value and CO/H2 Ratio on Syngas Diffusion Flame Structure

Syngas with CO/H2/N2 as the primary ingredients is the main fuel for the gas turbine in the IGCC system, but changes of the heating value and CO/H2 ratio frequently cause great impacts on the normal operation of the combustor, which is a challenge to the design of the syngas combustor. In this paper based on the Sandia/ETH-Zurich CO/H2/N2. Flame A, numerical simulations and predictions of the impacts of these two factors on the flame structure and diffusion combustion characteristics are carried out, and the main results are as follows. The heating value and CO/H2 ratio both have important impacts on the diffusion combustion characteristics. Most of the impacts have regularity such as changes of the axis velocity and temperature distribution, the highest temperature of the whole temperature field, the combustion efficiency and the NO formation with the heating value and CO/H2 ratio. However, the most important one is that the relationship between the flame size and the Wobbe Index is linear, for it has established connections between the structure size of the combustor and the characteristics of the fuel and the linear relationship can be used to provide reference for the combustor design. So the Wobbe Index is not only an important parameter to judge whether different fuels can be exchanged or not under the same initial pressure and heat load of a combustion equipment, but also an important parameter for syngas combustor design.Copyright © 2012 by ASME