采用发射光谱法检测煤粉锅炉火焰的技术研究

利用以CCD阵列作为光电接收元件的微型光纤光谱仪，在燃煤锅炉现场测量火焰从533nm至1050nm波段的发射光谱。通过对不同工况的在大量实测数据曲线进行分析处理，得到了视场中火焰平均温度和黑度。并发现：（1）煤粉火焰辐射基本上可以作为灰体辐射处理；（2）煤粉燃烧器负荷增大时，火焰黑度相应增大，火焰温度波动减小；（3）炉膛内背景火焰燃烧稳定，黑度远大于燃烧器出口火焰黑度，火焰温度波动明显降低；（4）未着火煤粉的温度较低，波动很小，黑度也很小。火焰发射光谱的这些特征为进行火焰监测和诊断提供了可靠的判据。图6表1参9

A Spectrum Analysis Technique for the On-Line Monitoring and diagnosing of Pulverized Coal Flame in Utility Boilers

The radiation spectrum of coal combustion flame from 533nm to 1050nm in wavelength was measured in utility boiler with a compact optical fiber CCD spectrometer. Based on the Wien's law, temperature and emissivity of flame are obtained by analyzing the measured data. The experimental results also show some interesting features. First, the rediation property of the pulverized coal flame is nearly same as the property of gray body. Second, with the increase of the load of burner, the flame emissivity increases and temperature fluctuation decreases, respectively. Third, combustion in the center of boiler is much stable and emissivity is much larger than that of flame at the outlet of the burner. And last, temperature and emissivity of unburned pulverized coal are lower and stable. These properties of the radiation spectrum are very useful for monitoring and diagnosing of coal combustion flame. Figs6, tables 2 and refs 9.