【作者】 欧阳奇；

【导师】 谢志江；

【作者基本信息】 重庆大学 ， 机械电子工程， 2007， 博士

【摘要】 回旋区是风口燃烧带上部焦炭做循环运动的空腔。回旋区温度场分布,影响高炉上部炉料的均衡下降、熔融渣铁的滴落和炉缸的煤气分布,对保证高炉整个冶炼过程连续、稳定地顺利进行起着至关重要的作用。随着高炉的大型化和大喷煤工艺和技术地不断提高,如何实现回旋区温度场实时监测与重构,对强化高炉冶炼、保证铁水产质量具有重要的理论和工业应用意义。基于辐射图像的高炉回旋区温度场重构的关键技术包括回旋区传热传质过程数值模拟、回旋区内弥散介质辐射特性、直吹管窥视孔方向CCD探测器成像过程、回旋区辐射图像与温度场计算关联模型与实验、回旋区光束辐射能传输过程及三维温度场重构算法。本文就此过程中的系列关键技术展开研究,研究主要内容和创新成果有:①回旋区传热传质过程数值模拟。回旋区内传热传质过程是研究基于辐射图像的回旋区温度场重构的主要内容之一,研究回旋区传热传质过程,为研究回旋区空间弥散介质辐射特性、窥视孔CCD成像过程、窥视辐射图像与回旋区温度关联模型、回旋区辐射能传输过程及鼓风温度对回旋区传热传质过程影响的工业应用研究打下基础。通过回旋区运行动力学分析,给出了回旋区几何尺寸计算方法,建立了k ?ε方程、煤粉热解挥发率方程、能量守恒方程及简化的化学反应混合分子数方程,数值模拟了回旋区的温度场、组分种类及组分浓度场分布,并建立了流场数据库。②回旋区弥散介质辐射特征研究。通过直吹管窥视孔方向CCD辐射图像,重构回旋区内温度场分布,其关键技术之一就是要知道回旋区内弥散介质的物质种类、辐射特性,以计算光束在回旋区内的辐射传递过程。通过合并谱带模型计算了回旋区内CO2、H2O蒸汽及NOx等气态燃烧产物的发射率随温度的变化关系及采用Lorentz-Mie电磁理论计算煤粉粒子、焦炭粒子及炭黑等弥散介质的平均衰减系数、平均散射系数及平均吸收系数随温度的变化,以及回旋区内气与固混合物的辐射特性。③研究了直吹管窥视孔方向CCD探测器成像过程。建立了回旋区成像系统光学模型,研究了回旋区三维空间对二维CCD靶面的成像机理,提出了回旋区辐射成像假设,解决了高炉风口直吹管窥视孔CCD成像的像源问题。同时针对CCD传感器在高温测试过程中由于辐射强度过大易出现输出过饱和电流导致“图像发白”问题,提出了CCD快门控制模型,以提高CCD测温动态范围。④研究灰体假设条件下回旋区辐射图像与温度场计算模型。研究CCD辐射图像与回旋区温度场重构方法,在回旋区几何光学成像假设条件下,通过单波长及双波长辐射成像光学计算与推导,建立基于单波长及双波长的辐射测温模型。对回旋区灰体假设条件下窥视辐射图像与回旋区温度关联模型及高温条件下CCD快门控制模型进行系列实验研究。⑤回旋区光束辐射能传输过程和三维温度场重构算法。提出了煤粉及焦炭燃烧火焰光束在回旋区内部的传输过程以及沿直吹管窥视孔方向CCD靶面接受热流的辐射传热方程(RTE)的蒙特卡洛(Monte Carlo)求解方法,研究了影响三维温度场重建的辐射能量分布份额α和β的影响因素,分析了辐射能量分布份额α和β对系数矩阵A的影响。在此基础上,研究和探讨了回旋区不同焦炭粒子浓度下窥视孔方向CCD靶面接受辐射能分布及回旋区的三维温度场重构问题。⑥工业应用研究。在回旋区灰体假设条件下和非灰体实际条件下的窥视孔CCD辐射图像与高炉回旋区温度场重构模型的基础上,展开了回旋区断面不同测点温度分布的实时监测与回旋区温度场三维重构的工业应用研究。应用表明:风口窥视孔辐射图像,直接反映了风口辐射强度的大小,反映了回旋区内煤气与固、液相进行热交换、回旋区的渣铁流及焦炭燃烧等工况。重构温度场几何形态分布与回旋区几何形态分布基本一致,同时,重构的温度场分布与流场计算的温度场分布基本吻合。同时,通过辐射图像,实现了高炉回旋区温度场、回旋区的活跃程度、渣皮和冷料滑落等工况的在线可视化监控,为操作人员提供了高炉风口区域的实时炉况信息,为指导高炉操作提供了科学的依据。本课题得到了国家自然科学基金和上海宝钢联合基金项目“高炉喷煤工况监控及炉缸分布模式研究(5037485)”的资助,以Planck辐射定律、回旋区内弥散介质辐射特性及回旋区辐射传递方程求解为基础,研究了基于辐射图像的回旋区温度场重构算法和实现方法,并进行了系列实验和现场验证,提出的关键技术具有理论和实用价值。更多还原

【Abstract】 The raceway is a cavum which coke is circularly moved at the upper of combustion strip. The temperature field distribution of raceway play an important role in continuous and steadily production through evenly descend of the upper charging of the blast furnace, the drippage of melted slag and iron, the gas distribution. With the improvement of the injected pulverized coal technology and aggrandizement of blast furnace cubage, it is an important role in strengthened smelt of the blast furnace and ensure the quality and output of the blast furnace.The reconstruction key technology of the raceway temperature field, which is based on CCD radiation imge, include the quality and heat transmission simulation of the raceway in the blast furnace, the dispersion medium radiation characteristics of the raceway, the CCD sensor imaging process at the direction of the blowtorch peephole, the computation model and experiment of radiation image and temperature field distribution of the raceway, the radiation energy transmission process and the three dimensional temperature field reconstruction arithmetic. According to this, this paper developed series theory and experiment studies, in which main results and innovation exists as follows:①Energy and quality transmission process simulation of the raceway. One of the main contents which are studied on the quality and energy transmission is carried out the temperature field reconstruction based on radiation image. It is a basic of developing a series of studies on the radiation characteristics of the dispersion medium in the raceway, the imaging process at the direction of the peephole, the relation model of the radiation image and the temperature field distribution, the radiation energy transferring process in the raceway and the industrial application at different blast temperature. The dynamics characteristic of the raceway is studied and the computation method of the raceway gemotery size and influence causes is provided, and the temperature field distribution, component and chroma distribution through k ?εequation, pulverized coal power volatilization and decompose model, simple chemical reaction eqation mix molecule equation. The flow field database is provided for computing the radiation characteristics of the dispersion medium.②The dispersion medium radiation characteristic computation of the raceway. The raceway temperature field reconstruction is carried out by radiation image at the direction of the blowtorch radiation image. One of the key technology is studied the radiation characteristics of the dispersion medium and the component kinds to compute the optical energy transmission process in the raceway. The spectrum of gas output ,such as CO2 and H2O steam, is computed through combined spectrum model, and the relation of the spectrum of the particles and mix combustion output between temperature in the raceway is get through Lorentz-Mie theory.③Study on the CCD imaging process at the direction of blowtorch peephole . The raceway imaging model and mechanism is studied. The imaging hypothesis is provided, and the computation results show it is almostly identical with CCD target imaging and virtual plane imaging. And because the problem of CCD super-saturation current output in the process of CCD untouched raceway high temperature measurement, so the CCD shutter control model is also provided to prevent from the super-saturation current output and exceed the CCD noise signal.④Study on the relation model about radiation image versus temperature field distribution at the suppose of gay ranceway. The 3-D temperature field reconstruction method is studied based on CCD radiation image. The single wavelength and dual-wavelength radiation measurement model is established through geometry imaging hypothesis condition. A seris of experiments were carried out for vertifying CCD shutter control model and relational model about radiation image versus temperature at the suppose of gay ranceway.⑤Three dimensional temperature reconstruction arithmetic and radiation energy transmission process study. The radiation energy transmission process along raceway and the computation of radiation transmission equation (RTE) is provided. The factor of radiation share parameters (αandβ), which is influenced coefficient matrix A are studied. The 3-D temperature field distribution and CCD target radiation energy distribution is analyzed in this paper.⑥Study on industry application. The industry application in raceway temperature field monitoring and 3-D reconstruction is studied at the basis of the raceway gray suppose and non-gray dispersion medium. The application results show that the radiation image of raceway directly reflect the radiant intensity, heat transmission of raceway. The reconstruction temperature geometry form distribution is almostly identify with the form distribution of the raceway. At the same time, the method can visually monitor the working states of of the raceway ,such as the temperature field distribtution, activity states, slide states of slag and cold stock and heat and quality transmission process. It is effective of instructing blast furnace operation through in-time information.The paper was Sponsored by National Natural Science Foundation of China and Shanghai Bao steel Group Co United Research Foundation (50374085) named by“The working state monitoring of the injected pulverized blast furnace”. A series of experiment and theory studies were carried out for monitoring and reconstructing 3-D temperature field based on radiation image at the base of RTE. It studied the series key technologies which had tested and have practical and popularized values. .更多还原