【作者】 文小军；

【导师】 谢植；

【作者基本信息】 东北大学 ， 检测技术与自动化装置， 2008， 硕士

【摘要】 温度是确定物质状态的参数之一,在科学实验和工业生产中温度信息的获得具有很重要的意义。铸坯表面温度测量一直是钢铁工业连铸生产中迫切需要解决的问题,铸坯表面温度是决定钢水过热度、调节拉速和二冷配水量的关键依据。若能实现铸坯表面温度的准确测量不仅为实现连铸拉速、二冷配水动态优化控制提供了温度检测保证,而且对提高铸坯(钢材)质量、拉速(产量)、节能降耗、安全生产等有直接影响。现代工业表面测温方法中主要有接触式和非接触式测温,其中非接触式测温中的辐射测温以其突出的优点在表面测温中得到了广泛的应用。在生产现场,当辐射温度计正确安装之后,被测表面的发射率就成为影响测量准确度的主要因素,但是发射率的测量至今仍然是个难题。本课题基于单层粗糙表面和多层平面的发射率研究基础,建立铸坯多层粗糙表面发射率模型,利用递推公式求得反射系数,根据基尔霍夫定律,进而求得发射率,并且进行了发射率的计算和分析。主要的内容如下：研究了发射率和散射之间的关系；利用高斯方法建立了一维高斯粗糙表面模型,对其散射系数和发射率进行仿真研究；建立多层平面模型,推导出发射率的递推公式,仿真其发射率的变化规律；建立铸坯表面多层发射率模型,在一维高斯粗糙表面和多层平面模型的基础之上,研究其发射率的变化规律,以及各种因素对发射率的影响；将仿真结果和实际的实验数据对比,修正。通过对单层粗糙表面和多层平面以及铸坯多层粗糙表面的p极化波的发射率仿真分析,发现存在一个发射率最大的角度--伪布鲁斯特角,在这个角度测量物体的p极化波发射率以提高温度测量的精确度。通过对比本文所建立的铸坯多层粗糙表面发射率模型的仿真数据和实际实验数据,变化趋势基本一致。本课题的主要创新点是建立了铸坯表面多层发射率模型,计算并仿真其发射率。更多还原

【Abstract】 Temperature is one of determining substance’s state reference, so acquiring information about it is very important for science experiment and industry production. In continuous casting surface, the urgent problem to be settled is the detecting of the surface temperature of the continuous casting, because this temperature is the important control parameter of confirming molten steel temperature, adjusting casting speed and it has direct influences on the result of secondary cooling. If the surface temperature can be settled exactly, it is not only providing guarantee for the temperature measuring of the continuous casting’s speed and secondary cooling dynamic controlling, but also have direct influence on improving metal quality, speed, reduce costing of energy and safety production. So the study of surface temperature is very important to control cooling models reasonably, adjust casting speed, improve casting flans quality and the successfully running of the whole continuous casting production line. Now, there are two dominating methods to detect the surface temperature via radialization, they are contactive and uncontactive method. And the infrared temperature measuring apparatus is applied in many areas because of its outstanding excellence. After the radiation measurement instruments are installed, the emissivity of surface is becoming the primary factor which bring biggish measuring error. However, the detection of the emissivity is still a difficult problem.This paper has based on the foundation of the emissivity of the rough monolayer and multilayers plane, created the model of casting multilayers surface’s emissivity, and calculated the emissivity via the reflective coefficient and the Kirchoff law, simulated and analysed the model.This paper’s main content is creation of the casting mltilayers surface’s emissivity and the simulation and calculation of the emissivity. According to the Kirchoff law:the object’s emissivity is equal to absorptivity in the same temperature, while the absorptivity is equal to 1 subtract the reflectivity, so the emissivity si equal to 1 subtract the reflectivity. In the first step, the paper has created the model of the casting rough multilayers’emissivtiy which based on the model of the monolayer rough surface and the multilayers plane’s emissivity. Then calculate the reflectivity of it. At last, we can conclude the emissivity’s expressions and simulate it.This paper has researched the theory and sense of the radiative detecting of the temperature, created the multilayer model about the emissivity, calculated the emissivity and presented it on the screen by the Matlab, compared the theory with the fact experimental data. The main content is as follows:Explain the contactive and uncontactive method; has studied the relation between the emisstivity and the scattering coefficient, created the 1-D rough surface by the Gauss method and researched the emissivity and scattering coefficient; work out the formula which can be used to calculate the emissivity based on the multilayer theory, simulate it by Matlab; create the rough multilayer and research its emissivity and simulate it by Matlab, piont out the very factors which can affect the emissivity; compared the simulated curve and the fact data at the end of the paper.According to the simulation and analysis of the monolayer rough surface,the multilayers plane and the casting rough multilayers surface, it has proved that there exist an angle which is called Pseudo-Brewster angle. We can improved the precision while detect the emissivity at this angle. According to the research we can conclude that the result of the model of the casting rough multilayers’emissivity is very close to the practice data, and it is creditable.The innovative point of the paper is to create model of the rough multilayer and calculate the emissivity.更多还原