基于Mie 散射理论水雾介质红外辐射衰减的校正研究

水雾环境对红外辐射有着较强的衰减作用。在工业生产中水雾环境十分常见, 连铸二冷区铸坯的冷却装置采 用的就是人工水雾系统, 而准确掌握连铸二冷区铸坯表面温度对提高产品质量的稳定性具有重要意义。针对二冷区 大量水雾对连铸坯表面非接触式测温存在干扰的问题, 提出了一种基于 Mie 散射理论的校正方法。首先根据现场使 用的气水喷嘴进行模拟实验, 分析现场水雾的水流分布, 建立水雾状态模型; 然后分析水雾状态模型下红外辐射的衰 减特性, 通过模拟试验计算得到相应的消光系数, 并利用朗伯比尔定律得到红外辐射衰减的校正因子, 将校正因子添 加至非接触式红外测温系统中进行实时温度值的校正。研究表明, 通过校正因子的导入能够有效地提高非接触式红 外测温系统的精度。

Correction of infrared radiation attenuation in water mist media based on Mie scattering theory

Water mist environment, which is very common in industrial production, has a strong attenuation effect on infrared radiation. The artificial water mist system is often used in the cooling device of continuous casting slab in secondary cooling zone, and it is of great significance to accurately measure the slab surface temperature in the secondary cooling zone of continuous casting to improve the stability of product quality. In view of the interference of a large amount of water mist in the secondary cooling zone on the non-contact temperature measurement of continuous casting slab surface, a correction method based on Mie scattering theory is proposed. Firstly, according to the air-water nozzle used in the field, the simulation experiment is carried out to analyze the flow distribution of the water mist, and the water mist state model is established. Then the attenuation characteristics of the infrared radiation under the water mist state model is analyzed, the corresponding extinction coefficient is calculated through the simulation experiment, and the correction factor of the infrared radiation attenuation is obtained by using Lambert Beer law. Finally, the correction factor is introduced into the non-contact infrared temperature measurement system to correct the real-time temperature value. The research shows that the accuracy of the non-contact infrared temperature measurement system can be effectively improved by introducing the correction factor.