OCR Text |
Show burner on NOx emission. Lower total momentum generally resulted in higher NOx except for flames J-M, in which oxygen was injected in the center nozzle with fuel through the annular nozzle. Reviewing Fig. 15 in conjunction with Fig 16 suggests an optimum range of total momentum in terms of total radiative heat flux and NOx' In this particular experiment, the optimum total momentum appears to be in the range of 0.5-1.0, where except for flames J-M, relatively high heat flux as well as low NOx are achieved. CONCLUSION We investigated the combustion characteristics of oxy-fuel flames to identify the optimum operating conditions for low NOx and high total radiative flux. A low velocity of gas and oxygen under 10 mls was necessary in order to generate high total radiative flux. In contrast, NOx increased with lower velocity of gas and oxygen. Low NOx oxy-fuel combustion was achieved by increasing the velocity of gas and oxygen. The optimum operating conditions for low NOx and high total radiative flux required a low velocity of gas and oxygen, preferably in the range of 5 to 10 m/s. Low NOx emission was observed with the FDI combustion technique, which is already utilized for high temperature preheated air combustion. REFERENCES 1. Saiki, N. and Koizumi, T., "Application of Low NOx Combustion Technique for Regenerative System," Proc. of AFRC/JFRC Pacific Rim International Conference on Environmental Control of Combustion Processes, 1994 2. Matsumoto, M., Nakamachi, I., Yasuoka, S., Saiki, N. and Koizumi, T., "Advanced Fuel Direct Injection - FDI System," Proc. of 11th IFRF Members Conference, 1995 |