School of Power and Mechanical Engineering,Wuhan University

基于CCD相机的双色法广泛应用于燃烧温度场和烟黑浓度场测量,为认识燃烧规律和掌握燃烧状态发挥重要作用。已有工作大多忽略CCD相机的光谱响应特征,而将CCD相机各通道检测信号视为火焰在特定波长处辐射能量,给测量结果带来误差,并鲜有针对光谱响应曲线简化所引起测量误差的分析。以乙烯/空气层流扩散火焰为例,模拟不同光谱响应曲线CCD相机的火焰重建过程,分析了形状、半宽、不对称性等不同光谱响应曲线参数对火焰温度及烟黑浓度重建精度的影响。结果表明,光谱响应曲线形状和半宽对重建精度影响较小,在无测量误差条件下,温度场平均重建误差均小于1%;当光谱响应曲线不对称或中心波长不准确时,重建结果误差明显增大,在无测量误差条件下,温度场平均重建误差可达2.4%。对CCD相机进行黑体炉及光谱响应曲线标定,通过CCD相机对乙烯层流扩散火焰进行测量发现,利用中心波长和实际光谱响应曲线测量结果具有明显偏差,最高温度和最大烟黑浓度偏差分别为4.74%和16.4%。

The two-color method based on CCD cameras is widely used for measuring the combustion temperature field and soot volumefraction field, playing an important role in understanding combustion laws and mastering combustion states. However, most of the existingwork ignores the spectral response characteristics of CCD cameras and regards the detection signals of each channel of the CCD camera asthe radiant energy of the flame at a specific wavelength, which brings errors to the measurement results of combustion temperature and sootvolume fraction. In this work, an ethylene/ air laminar diffusion flame was considered. The impact of various parameters of the spectral response curves (SRC), such as shape, half width, and asymmetry, on the accuracy of reconstructed flame temperature and soot concentration were analyzed. It is found that the influence of SRC shape and bandwidth on the reconstruction accuracy is small, the reconstructionerrors of the temperature field are all below 1% without considering signal error. If the SRC is asymmetric or the center wavelength is inaccurate, there are relatively larger errors in the reconstruction results, and the errors of the temperature field may achieve 2.4% without considering signal error. Through experimental measurement of ethylene laminar diffusion flame by a CCD camera, it is found that thereis a significant deviation between the measurement results using the center wavelength and the actual SRC, and the maximum temperatureand maximum soot volume fraction errors are 4.74% and 16.4%, respectively.

国家自然科学基金资助项目(52076155)

韩磊,程勇,朱宁静,等.光谱响应曲线对双色法燃烧测量技术精度影响[J].洁净煤技术,2024,30(8):128-137.

HAN Lei,CHENG Yong,ZHU Ningjing,et al.Effect of spectral response curves on accuracy of combustion measurementtechniques based on two-color method[J].Clean Coal Technology,2024,30(8):128-137.