Comparison of detailed nitrogen-containing mechanisms in preheating combustion technology under O2/CO2 atmosphere

Comprehension of the nitrogen-containing mechanism in oxy-fuel combustion is beneficial for understanding the migration path of NOx under an O-2/CO2 atmosphere and controlling the emissions of NOx. In this study, the Chemkin code was used, and the various nitrogen-containing detailed mechanisms and experimental results were compared and analyzed to explore the adaptability of the existing detailed nitrogen-containing mechanism in oxy-fuel combustion and the influencing factors of NOx in the down-fired combustor (DFC) of the novel preheating combustion technology. A Perfectly Stirred Reactor (PSR) was chosen to simulate the combustion process of the DFC. Multiple detailed nitrogen-containing mechanisms were compared and analyzed. The results showed that the results for the simulation tendency using these mechanisms in the PSR reactor model were consistent with the experimental results. The mechanisms for the smaller NO concentration error between the predicted results and the experimental results of the oxy-fuel preheated combustion technology were USC-Mech 2.11 NOx, GRI-Mech 2.11, konnov0.6, and PG2009. Moreover, in the main combustion zone, the reaction with the highest NO production rate in all detailed nitrogen-containing mechanisms was HNO+H <=>NO+H-2.

Automated summary

In this study, various nitrogen-containing mechanisms and experimental results were compared and analyzed to explore the adaptability of existing mechanisms in oxy-fuel combustion. The results showed that the selected mechanisms had good agreement with the experimental results, with smaller prediction errors.