燃煤电站锅炉空气分段低NO_x燃烧影响因素的数值模拟

Numerical Simulation of Influential Factors on Air Staging Low NO_x Combustion for Coal-fired Utility Boilers

空气分段低NOx燃烧技术目前已逐渐用于现役燃煤电站锅炉的改造和锅炉设计中,通过CFD软件平台,使用数值计算的方法对空气分段燃烧技术进行研究。研究了影响燃煤电站锅炉NOx排放的因素,讨论了影响空气分段燃烧生成NOx的因素。计算结果表明,分段风喷口高度是影响最终NOx排放浓度的重要因素之一。在一定有效范围内,NOx排放浓度随着分段风喷口高度的变化并不大;分段风抽风量也是影响NOx生成的重要因素,NOx排放浓度随着分段风抽风量增大而降低。另外还需综合考虑实际锅炉的运行情况、经济效益和环境效益等各方面因素,进行合理的优化选择最佳运行参数。

Air staging low NOx combustion is a kind of applicable technology. Numerical simulation of an air staging coal-fired utility boiler is performed on Computational Fluid Dynamics （CFD） software platform. Factors on nitrogen oxides （NOx） emission of air staging are compared and researched. Results show that the height of air staging injector is an important factor on NOx emission. NOx, emission amount changes a little when the height of the sir staging injector increases in a certain range. NOx emission is also influenced by the amount of staging air. NOx emission decreases when staging air increases. To get optimize operating parameters, other factors including operating situation, economic efficiency and environment effect should also be considered.