由于“双碳”目标下新能源发电比例的升高削弱了电网调峰能力,致使燃煤机组面临着深度调峰需求。以某电厂600MW八角切圆锅炉为对象,研究其超低负荷(28%额定负荷)下的多参数协同优化方案。通过构建全尺寸三维模型,分析燃烧器喷口配置、过量空气系数、燃尽风比例及燃烧组织方式对燃烧特性与污染物排放的影响。结果表明：适当提高过量空气系数可显著提升燃烧效率,但会增加NO_x排放；燃尽风比例为10%时,可以实现最高燃烧效率；燃尽风比例为15%时,NO_x排放最低；四层燃烧器配置侧重于降低污染物排放,其NO_x排放浓度较三层配置减少22.8 mg/m3；而三层配置侧重于提升锅炉热效率,其飞灰未燃尽碳含量较四层配置下降0.59%。

The increased proportion of renewable energy generation under the "dual carbon" goals has diminished the grid"s peak-shaving capability, resulting in deep peak-shaving demands for coal-fired units. This study investigates a multi-parameter cooperative optimization scheme for a 600 MW octagonal tangentially-fired boiler under ultra-low loads (28% rated load). A full-scale three-dimensional model was constructed to analyze the effects of burner configuration, excess air ratio, overfire air (OFA) ratio, and combustion organization on combustion characteristics and pollutant emissions. The results indicate that:Increasing the excess air ratio significantly improves combustion efficiency but elevates NOx emissions. An OFA ratio of 10% achieves peak combustion efficiency;Whereas a 15% OFA ratio delivers minimal NOx emissions concentration.The four-layer burner configuration is designed for reduced pollutant emissions, exhibiting a 22.8 mg/m3 lower NOx concentration than the three-layer configuration; conversely, the three-layer configuration is optimized for enhanced boiler thermal efficiency, resulting in a 0.59% reduction in unburned carbon content within the fly ash compared to the four-layer configuration.

吉林省自然基金项目(20210101072JC)