Numerical Simulation of Combustion Characteristics and NOx Emissions in a 300 MWe Utility Boiler with Different Outer Secondary-Air Vane Angles

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• 作者：Lingyan Zeng ; Zhengqi Li ; Guangbo Zhao ; Shanping Shen ; Fucheng Zhang
• 刊名：Energy & Fuels
• 出版年：2010
• 出版时间：October 21, 2010
• 年：2010
• 卷：24
• 期：10
• 页码：5349-5358
• 全文大小：1174K
• 年卷期：v.24,no.10(October 21, 2010)
• ISSN：1520-5029

文摘

We experimentally and numerically studied the pulverized-coal combustion process and NO_x emissions for a 300 MW_e wall-fired boiler burning bituminous coal. Measurements of the polar components of the gas velocity made with a particle-dynamics anemometer and calculated values are found to be in good agreement. Good agreement was also found for the CO₂ concentration, NO_x concentration, and combustible material content in the fly ash between simulation and industrial experiments performed on full-scale boilers. For enhanced ignition−dual register (EI−DR) burners, pulverized coal is spread widely from the burner. Some pulverized-coal particles are thrown to the furnace hopper, and much pulverized coal is swept to the furnace hopper at the bottom of the boiler. As the outer secondary-air vane angle increases, the temperature of the water-cooled tube wall region near the burners and furnace hopper increases. Changes in the NO_x concentration at the furnace outlet are not simply linear with changes in the outer secondary-air vane angle. The NO_x concentration at the furnace outlet was lowest (420.2 ppm at 6% O₂) for an outer secondary-air vane angle of 35° and highest (468.2 ppm at 6% O₂) for an outer secondary-air vane angle of 30°. This represents an increase of 11.4%.