Investigation of the NO emission during high temperature air combustion (HTAC) of light oil

Studies on NO formation in the case of the preheated air in accordance with the rules of HTAC of light oil were presented. Due to providing good dispersion of oil droplets, an air assisting atomizer was used. The light furnace oil was used. It was assumed that oil evaporates and decomposes to CH₄. The reduction of NO to N₂ was also incorporated using reactions with CH, CH₂, and CH₃. According to both the experiment and the model, temperature increased along the burner axis and reached maximum in the recirculation whirls. Observed maximum of temperature depended on air inlets distance and in the case of internal one did not exceed 1300 K but in the case of external one reached 1500 K. Recirculation exceeded the ratio of 3.5:1 in the case of the internal distance. The thermal mechanism was the most important path of NO growth in the case of pure oil combustion and due to high temperature dependence the external distance provided higher NO emission. The fuel bound nitrogen mechanism dominated after using nitrogen additives (pyridine) in the fuel, and in this case due to high oxygen concentration dependence the external distance was a better solution. This is an abstract of a paper presented at the 30th International Symposium on Combustion (Chicago, IL 7/25-30/2004).