600MW超临界空冷机组锅炉燃烧调整试验研究

Test Study on Combustion Adjustment for Boiler in 600 MW Supercritical Air-cooled Unit

为提高锅炉运行安全与经济性,某电厂600 MW空冷机组进行了燃烧调整试验。详细研究了一次风配风均匀性、制粉系统挡板特性、运行氧量和燃尽风率对锅炉效率的影响。结果表明:煤粉随着分离器挡板开度增大和一次风量增加逐渐变粗;随着氧量降低,锅炉效率逐渐增大,额定负荷下氧量保持在3.0%左右最佳;随着燃尽风率降低,锅炉效率逐渐增大,NOx排放浓度逐渐增加。综合考虑锅炉效率、NOx排放浓度和屏过管壁金属温度,额定负荷下燃尽风挡板开度保持在75%左右最佳,此时NOx质量浓度为385.1 mg/Nm3。通过燃烧调整,锅炉效率提高0.45个百分点,调整后锅炉效率在93.15%以上。

The test study on combustion optimization and adjustment of boiler in a 600 MW air - cooled power plant is made for enhancing operation security and economy of boiler. The effects of primary air distribution uniformity, baffle characteristics of milling system, operation oxygen, and over fire air rate on boiler efficiency are researehed. The results show that fineness of pulverized coal gradually increases as opening degree of separator baffle and primary air flow increasing. Boiler efficiency increases as oxygen increasing, and optimal oxygen is about 3.0% in the condition nominal load. As over fire air rate increasing, boiler efficiency and NOx emission concentration gradually increase. Considering the boiler efficiency, NOx emission concentration and metal temperature of platen superheater well, optimal opening degree of over fire air baffle keeps about 75% in the condition nominal load, and then NO, emission concentration is 385. 1 mg/Nm3. Boiler efficiency can enhance 0. 45 percentage point, upwards 93. 15% after combustion adjustment of boiler.