针对高炉风口回旋区CCD工况检测中图像过饱和失真问题,提出了CCD光积分时间控制模型,解决高炉回旋区辐射测温过程中CCD在由于辐射强度过大易出现输出过饱和电流导致“图像发自”问题,并进行了高炉回旋区断面温度与CCD快门时间关联实验,并给出了一定快门时间下温度与图像灰度计算模型;理论和实验研究表明,CCD快门时间过长,使图像的清晰程度下降甚至不可辨;通过控制CCD快门时间,可提高CCD辐射测温动态范围;工业应用表明,这种方法能实现高炉风口回旋区断面温度的在线非接触测量和回旋区工况监控。
Aimed at CCD image saturation distortion in working state monitoring for blast furnace raceway, the charged coupled devices (CCD) optical integration time control model is proposed to solve blushing image problem, which is caused by CCD super saturated current output because of too much radiation intensity, and a series of experiment is carried out to study the relation and compute model between CCD integration time and temperature. Through theory and experiment study, it is proved that too long CCD integration time lead to saturated charge in the potential well and charge overflow phenomenon. Temperature dynamic range can be increased through adjusting CCD optical integration time control method. The industry application has showed that it is effective of realizing raceway section temperature measurement and working state monitoring on line.