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以国内首台3 MW_(th)富氧燃烧煤粉锅炉为研究对象,借助CFD软件对煤粉空气燃烧和富氧燃烧工况进行数值模拟研究。通过与实验结果对比发现,模拟得到的炉膛温度分布、换热量以及出口组分与实验测量结果吻合,这表明本文使用改进的辐射特性模型以及4步化学反应机理能够很好地预测炉内温度、传热以及烟气组分分布。通过模拟研究,对比分析了空气燃烧与富氧燃烧的炉内特性。研究结果表明:富氧燃烧时,CO_2的显著增加使得燃烧器区域出现高浓度CO;富氧燃烧的整体温度分布与空气燃烧相似,但峰值温度有较大的降低;炉内辐射传热较空气燃烧略有下降。
Taking the first 3 MW_ (th) oxyfuel pulverized coal fired boiler as the research object, CFD software was used to simulate the air-combustion and oxygen-enriched combustion of pulverized coal. Compared with the experimental results, it is found that the simulated temperature distribution, heat transfer and outlet components agree well with the experimental results, which indicates that the improved radiation characteristics model and the four-step chemical reaction mechanism can well predict the furnace temperature , Heat transfer and flue gas composition distribution. Through the simulation study, the characteristics of the furnace in air combustion and oxygen-enriched combustion are comparatively analyzed. The results show that the CO 2 enrichment increases the concentration of CO in the combustor at rich oxygen combustion. The overall temperature distribution of oxy-fuel combustion is similar to that of air combustion, but the peak temperature is greatly decreased. Burning slightly down.