多晶硅铸锭炉温度场可视化分析及其结构优化

发布时间：2018-06-02 05:53

本文选题：铸锭炉 + 热场结构　；参考：《太原理工大学》2015年硕士论文

【摘要】：太阳能作为一种可再生清洁能源，为解决能源危机、环境污染等问题做出了巨大贡献。多晶硅铸锭炉生产的硅锭作为太阳能电池的主要材料，，硅锭的质量直接影响太阳能电池的光电转换效率。硅料在铸锭炉内通过加热系统将硅料熔化，硅液在竖直方向的温度梯度下开始结晶生长硅锭。硅锭内碳、氧等非金属杂质和少子寿命都直接或间接受到炉体内温度分布影响。加热系统包括加热体、坩埚、石墨平台、隔热屏等，这部分实体结构称为“热场”结构。国内对多晶硅铸锭炉热场的研究相对比较少，本文以某企业生产的450kg铸锭炉作为研究对象，进行了以下研究：利用有限元ANSYS软件对450kg多晶硅铸锭炉硅料熔化过程进行数值分析与试验研究，通过仿真与试验对比，验证仿真模型及参数的正确性。保持450kg铸锭炉在炉体不变情况下，增大坩埚尺寸，改变加热体等其他热场结构位置，增大有效加热区域，将450kg铸锭炉升级为550kg铸锭炉。文章对550kg铸锭炉硅料加热熔化过程中炉体内温度分布情况进行研究，计算结果表明，550kg铸锭炉中硅料可以完全熔化，进行下一阶段的结晶生长，且单位质量的硅料熔化时间明显缩短，有利于提高硅锭的生产效率，减少能量的消耗。石墨加热体作为铸锭炉的加热部分，为硅锭的生产提供能量。通过公式计算对加热体的加热功率进行计算校核，计算结果表明，加热体的加热功率符合多晶硅铸锭炉的要求。利用ANSYS Workbench软件对石墨加热体进行热-电耦合计算，加热体的最高温度及加热体的温度均匀性都符合设备的使用要求。隔热笼作为多晶硅铸锭炉热场结构的重要组成部分，主要用来支撑、固定隔热屏及控制隔热屏的升降运动。隔热笼受热变形超过一定程度，会引起直线导轨的扭曲变形，对隔热笼提升机构造成损坏。本文对隔热笼结构进行优化设计，并利用ANSYS Workbench软件对隔热笼结构优化前后的三维模型分别进行热-结构耦合计算。隔热笼结构优化前后，温度分布基本相同，但是隔热笼结构优化后，隔热笼所受到的最大热变形明显减小，且变形分布更加均匀，隔热笼结构优化效果明显，有利于提高隔热笼的使用寿命。
[Abstract]:As a renewable and clean energy, solar energy has made great contribution to solving the energy crisis and environmental pollution. The silicon ingot produced by polycrystalline silicon ingot furnace is the main material of solar cell. The quality of silicon ingot directly affects the photoelectric conversion efficiency of solar cell. The silicon material is melted by heating system in the ingot furnace, and the liquid of silicon begins to crystallize and grow under the vertical temperature gradient. The carbon, oxygen and minority carrier lifetime in silicon ingot are directly or indirectly affected by the temperature distribution in the furnace. The heating system includes heating body, crucible, graphite platform, heat shield and so on. This part of solid structure is called "thermal field" structure. The research on the thermal field of polysilicon ingot furnace in China is relatively few. This paper takes the 450kg ingot furnace produced by a certain enterprise as the research object, carries on the following research: The melting process of silicon in 450kg polycrystalline silicon ingot furnace was analyzed and tested by finite element ANSYS software. The correctness of simulation model and parameters was verified by comparison of simulation and test. The 450kg ingot furnace can be upgraded to 550kg ingot furnace by increasing the size of crucible, changing the position of other heat field structures such as heating body and increasing the effective heating area under the condition of keeping the furnace body unchanged. The temperature distribution of silicon in 550kg ingot furnace during heating and melting is studied. The calculated results show that silicon can be melted completely in 550kg ingot furnace, and then crystal growth is carried out in the next stage. The melting time of silicon material per unit mass is shortened obviously, which is beneficial to improve the production efficiency of silicon ingot and reduce the energy consumption. As the heating part of ingot furnace, graphite heater provides energy for the production of silicon ingot. The heating power of the heating body is calculated and checked by the formula calculation. The calculation results show that the heating power of the heating body meets the requirements of polycrystalline silicon ingot furnace. The thermal-electric coupling calculation of graphite heaters using ANSYS Workbench software shows that the maximum temperature of the heaters and the temperature uniformity of the heaters meet the requirements of the equipment. As an important part of the thermal field structure of polysilicon ingot furnace, the heat insulation cage is mainly used to support, fix and control the lift and down movement of the insulation screen. If the thermal deformation of the thermal insulation cage exceeds a certain degree, it will cause the distortion of the linear guide rail and damage the hoisting mechanism of the thermal insulation cage. In this paper, the optimization design of the thermal insulation cage structure is carried out, and the thermo-structural coupling calculation of the three dimensional model before and after the optimization of the thermal cage structure is carried out by using ANSYS Workbench software. Before and after optimization, the temperature distribution is basically the same, but after the optimization, the maximum thermal deformation of the thermal insulation cage is obviously reduced, and the deformation distribution is more uniform, and the optimization effect of the thermal insulation cage structure is obvious. It is beneficial to improve the service life of the insulation cage.
【学位授予单位】：太原理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN304.12

【参考文献】