电熔镁炉声信号采集与分析系统的研究

发布时间：2018-08-06 18:40

【摘要】：电熔氧化镁是一种熔点高、耐腐蚀、绝缘性能好的高级耐火材料,其大量应用于冶金、国防、核工业等领域,制备电熔氧化镁的主要生产设备是电熔镁炉。电熔镁炉熔炼现场环境十分恶劣,熔炼生产时存在着复杂的外部扰动,电熔镁炉本身还是一个强非线性、时变性和强耦合性的控制对象,电熔镁炉不同的熔炼状态需要不同的操作策略,而目前电熔镁炉熔炼状态的判断主要依赖于现场操作人员的主观经验,不能够准确的判断出电熔镁炉的熔炼状态,不利于电熔镁炉的自动控制,影响产品的质量和节能减排。本文在国家高技术研究发展计划(863计划)项目“菱镁矿绿色熔炼关键技术与装备”的支持下,以营口某工厂的一台电熔镁炉为冶炼对象,针对电弧声信号与电弧电流之间的数学关系推导出了电弧声信号的数学表达式,确立了电熔镁炉声信号采集测量点的位置,利用NI数据采集卡搭建了数据采集硬件平台,利用图形化编程软件LabVIEW设计开发了电熔镁炉声信号采集与分析系统。本文设计的电熔镁炉声信号采集与分析系统可以实现身份登录、数据采集、数据存取、信号降噪与时频分析、远程控制等功能。利用该系统采集了整个电熔镁炉冶炼过程中不同熔炼状态下的电弧声信号和电流信号,对采集进来的电弧声信号选取了db04小波进行软阈值法降噪,利用LabVIEW和MATLAB混合编程的方式绘制了电弧声信号的小波时频图。通过对电熔镁炉不同熔炼状态下的声强信号、三相电流幅值和电弧声信号时频图的分析提取出了识别电熔镁炉不同熔炼状态的特征判据,现场熔炼实验证明该判据能够有效的判断电熔镁炉的各种工况,提升了产品质量,降低了单吨能耗,为电熔镁炉自动冶炼技术提供了一种新的研究方法。
[Abstract]:Fused magnesium oxide is an advanced refractory with high melting point, corrosion resistance and good insulation performance. It is widely used in metallurgy, national defense, nuclear industry and other fields. The main production equipment for the preparation of fused magnesium oxide is electric melting magnesium furnace. The environment of melting site in electric melting magnesium furnace is very bad, and there are complex external disturbances in smelting production. The furnace itself is a strong nonlinear, time-varying and strong coupling control object. Different melting states of electric melting magnesium furnace need different operation strategies, but at present, the judgment of melting state of electric melting magnesium furnace mainly depends on the subjective experience of field operators, and can not accurately judge the melting state of electric melting magnesium furnace. It is unfavorable to the automatic control of electric melting magnesium furnace and affects the quality of products and energy saving and emission reduction. Supported by the National High Technology Research and Development Program (863 Program) "key Technologies and equipment for Green melting of magnesite", this paper takes an electric melting magnesium furnace in a factory in Yingkou as a smelting object. According to the mathematical relation between arc sound signal and arc current, the mathematical expression of arc sound signal is deduced, the position of measuring point of electric melting magnesium furnace sound signal is established, and the hardware platform of data acquisition is built by using NI data acquisition card. The acoustic signal acquisition and analysis system of fused magnesium furnace is designed and developed by using graphical programming software LabVIEW. The acoustic signal acquisition and analysis system designed in this paper can realize the functions of identity login, data acquisition, data access, signal denoising and time-frequency analysis, remote control and so on. The electric arc sound signals and current signals in different melting states in the whole smelting process of the electric melting magnesium furnace are collected by this system. The db04 wavelet is selected to reduce the noise of the acquired arc sound signals by soft threshold method. The wavelet time-frequency diagram of arc sound signal is drawn by LabVIEW and MATLAB. By analyzing the sound intensity signal, the amplitude of three-phase current and the time-frequency diagram of the electric arc sound signal in different melting states of the fused magnesium furnace, the characteristic criteria for identifying the different melting states of the electric melting magnesium furnace are obtained. The field smelting experiments show that the criterion can effectively judge the various working conditions of the fused magnesium furnace, improve the quality of the product and reduce the energy consumption of one ton. It provides a new research method for the automatic smelting technology of the electric melting magnesium furnace.
【学位授予单位】：大连理工大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TP274.2

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