660MW超临界直流锅炉大比例燃用准东煤燃烧调整试验分析

Experimental Analysis on Combustion Adjustment in 660 MW Supercritical Once-Through Boiler Fired with Zhundong Coal in Large Proportion

准东煤因其灰分低、易着火、燃尽性好等优点通常被作为优良的动力用煤,但因其煤灰中碱金属含量较高,容易出现受热面沾污、腐蚀、结渣等危害锅炉运行安全的问题。在大比例燃用准东煤的过程中,为了增大锅炉热效率、减小热偏差、降低污染物排放量、防止受热面结渣和提高锅炉燃烧经济性,首先通过摸底试验测定了某660 MW锅炉目前的运行情况及特性;其次通过调整运行氧量、燃尽风风量、二次风配风方式等运行方式,对锅炉炉体进行燃烧优化调整;最终根据试验结果给出针对此660 MW超临界直流锅炉高负荷、大比例燃用准东煤时的最优运行方案,在保证安全性的基础上进一步提高锅炉经济效益与整体效率。

Zhundong coal is usually used as good power coal because of its low ash content,easy ignition,good combustion properties and other advantages.However,larger amount of alkali metal in its ash can cause the contamination,corrosion and slagging of heating surface,which may harm the operation safety of boilers.In order to increase the thermal efficiency,reduce the thermal deviation,reduce the emission of pollutants,prevent the slagging of heating surface and improve the combustion economy of the boiler in the process of blending a large proportion of Zhundong coal,the current operation and related characteristics of a 660 MW boiler are measured;by adjusting the operating oxygen content,the over-fire air and the secondary air distribution,the combustion of the boiler is optimized.According to the test results,the optimal operation scheme of the 660 MW supercritical once-through boiler with high load and a large proportion of Zhundong coal is proposed.On the basis of safety,the economic benefits and overall efficiency of the boiler are further improved.