多晶硅结晶炉研制及凝固工艺

发布时间：2018-05-25 00:03

本文选题：多晶硅结晶炉 + 火焰加热　；参考：《昌吉学院》2017年硕士论文

【摘要】：在能源短缺、环境恶化的今天,可再生光伏发电产业迅速发展,逐渐成为世界能源的重要组成部分。其中多晶硅是光伏产业中太阳能电池生产的重要原料之一。目前市场上并没有专门针对教学科研的价格便宜的小型多晶硅结晶炉。最小装炉量的浙江精功5公斤铸锭炉价格在五十万左右,不太适合于大多数高校新能源实验室。有鉴于此,本篇毕业论文的主要内容是研制一种小型多晶硅实验结晶炉,并应用它开展一些熔炼实验。本文首先介绍了多晶硅铸锭生产的意义和国内外的市场情况,并对多晶硅结晶炉的生产方法进行分析介绍;之后根据多晶硅生产工艺及对多晶硅结晶炉熔炼的要求,提出了两种不同的设计方案,并分别制成装炉量三十克左右的小型化样机。其一为火焰加热方式,冷却水包热交换法定向凝固,其二是感应加热方式,提拉法定向凝固。方案一加热方式为独创性的火焰加热,温度场易控且从根本上比其他方式变化平稳。该方式区别于焰熔单晶生长方式,这是因为在方案一中熔炼硅的工况温度远大于喷嘴材料熔点,这是焰熔法所没有的技术难点,再则因为本方案中坩埚是在热场中依靠辐射均匀受热,而不是物料在火焰上熔化。在方案二中,直流电源经mos场效应管推挽开关二阶振荡电路输出中频交流电,供给感应加热线圈,结晶炉全封闭隔绝空气,用燃烧的炭做牺牲阳极除氧,压力升高时,单向阀导通泄压。方案二创新之处在于定向凝固方式:间歇式提拉,提拉一段时间,停歇更长的时间,让晶体生长不受震动引起的能量起伏的干扰,间歇提拉用单片机控制步进电机实现。电机驱动采用spwm细分技术,这样能使得提拉机械系统运动平稳。方案二进行了二十多次熔炼实验,实验结果及现场实际运行情况表明,该结晶炉设计方案合理,完全达到了预期设计目标要求,可有效提高多晶硅的产品品质并且熔炼工艺参数可调,方便进行熔炼实验。
[Abstract]:With the shortage of energy and the deterioration of environment, renewable photovoltaic power generation industry has developed rapidly and become an important part of the world energy. Polysilicon is one of the important raw materials for solar cell production in photovoltaic industry. There is no small, inexpensive polysilicon crystallization furnace for teaching and research. The price of the 5 kg ingot furnace with the minimum charge of Zhejiang fine work is about 500000, which is not suitable for the new energy laboratory of most colleges and universities. In view of this, the main content of this thesis is to develop a small type of polysilicon experimental crystallization furnace, and use it to carry out some melting experiments. This paper first introduces the significance of polysilicon ingot production and the market situation at home and abroad, and analyzes the production method of polycrystalline silicon crystallization furnace, and then according to the production technology of polysilicon and the requirements of polysilicon crystallization furnace melting, Two different design schemes are put forward, and a miniaturized prototype with about 30 g furnace volume is made. One is the flame heating method, the other is the induction heating method and the Czochralski method. Scheme one is original flame heating, the temperature field is easy to control and basically changes smoothly compared with other ways. This method is different from the growth mode of single crystal by flame melting, because the temperature of melting silicon in scheme one is much higher than the melting point of nozzle material, which is a technical difficulty that the flame melting method does not have. Moreover, the crucible in this scheme is uniformly heated by radiation in the thermal field, rather than the material melting on the flame. In the second scheme, DC power source outputs intermediate frequency alternating current through mos field effect transistor push-pull switch second order oscillation circuit, supplies induction heating coil, crystallizer completely seal off air, uses burning carbon as sacrificial anode to deoxidize, when the pressure rises, One way valve leads to discharge pressure. The innovation of the second scheme lies in the directional solidification mode: intermittent Czochralski, Czochralski for a period of time, stopping longer time, so that the crystal growth is not disturbed by the energy fluctuation caused by vibration. Intermittent Czochralski is realized by the stepper motor controlled by single chip computer. Spwm subdivision technology is used to drive the motor, which can make the motion of the drawing mechanical system stable. More than twenty melting experiments have been carried out in the second scheme. The experimental results and the actual operation on the spot show that the design scheme of the crystallization furnace is reasonable and fully meets the requirements of the expected design objectives. It can effectively improve the product quality of polysilicon, and the melting process parameters can be adjusted, which is convenient for melting experiments.
【学位授予单位】：昌吉学院
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TQ127.2

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