基于相机响应函数和双色测温的火焰温度场重建方法

Reconstruction method of flame temperature field based on camera response function and two-color pyrometry

为简单高效非侵入式测量火焰温度,基于相机响应函数和双色测温法,提出1种非侵入式火焰温度场重建技术。利用传感器成像原理,重新推导双色测温公式,内置色彩滤波器阵列的CMOS相机经过辐射自校准后,得到相机响应函数,进而揭示数字像素强度与辐照度之间关系;基于辐照度比值并通过彩色图像红绿通道,重建火焰二维温度场,将重建的温度值与热电偶测量值进行比较。研究结果表明:火焰温度场分布存在明显的高温锋面和轴向双峰特点,重建温度与测量值最大相对误差约为6.34%,吻合良好。该方法可以准确反映温度场分布特征和结果,基本实现非侵入式温度场有效重建。

For the simple and efficient non-invasive measurement of flame temperature,a reconstruction technology of non-invasive flame temperature field was proposed based on the camera response function and two-color pyrometry method.Based on the principle of sensor imaging,the two-color pyrometry formula was deduced again.After the CMOS camera with built-in color filter array was self-calibrated by radiation,the camera response function was obtained,and then the relationship between digital pixel intensity and irradiance was revealed.Based on the irradiance ratio and through the red-green channel of color image,the two-dimensional temperature field of flame was reconstructed,and the reconstructed temperature values were compared with the thermocouple measurement values.The results showed that the flame temperature field distribution has obvious high-temperature front and axial bimodal characteristics.The maximum relative error between the reconstructed temperature and the measured value is about 6.34%,which indicates the good agreement.This method can accurately reflect the distribution characteristics and results of temperature field,and realize the effective reconstruction of non-invasive temperature field.