吹氩连铸结晶器液面波动行为的时频分析

Time-frequency analysis of level fluctuation behavior in argon blowing continuous casting mold

时频分析是一种研究波动信号特征、揭示波动现象内在机理的有效方法。将时频分析方法应用于吹氩连铸结晶器内的液面波动特性研究,采用水模型试验获取液面波动数据进行时频分析,研究吹氩量、拉速、水口浸入深度和结晶器宽度等工艺参数对液面波动行为的影响,探究液面波动的内在机理。结果表明,振幅较高的频率集中在0~2.5 Hz,其中振幅最大的主频率位于0.1 Hz附近,此外1.5 Hz和2.5 Hz处也存在较高的峰值;通过时域分析发现,增大吹氩量和拉速、或减小水口浸入深度和结晶器宽度将加剧液面波动;通过频域分析发现,拉速、水口浸入深度、结晶器宽度与液面波动主频率有较强的关联性,说明三者均与液面波动的主要振动源高度相关。

Time-frequency analysis is an effective method to explore the characteristics of fluctuation signals and reveal the internal mechanism of fluctuation phenomena.The time-frequency analysis method was applied to study the level fluctuation in argon blowing continuous casting mold,and it was used to process the level fluctuation data obtained by a water model experiment.The effects of various operating parameters such as argon blowing rate,casting speed,nozzle immersion depth and mold width on the level fluctuation were studied to explore the internal mechanism of level fluctuation.Results show that the frequencies with high amplitude are concentrated in 0-2.5 Hz,and the fundamental frequency with the largest amplitude is near 0.1 Hz.In addition,there are high peaks noticed at 1.5 Hz and 2.5 Hz.Based on the time domain analysis,level fluctuation intensity will be aggravated by increase of argon blowing rate and casting speed or decrease of nozzle immersion depth and mold width.Based on the frequency domain analysis,the casting speed,nozzle immersion depth and mold width strongly correlate with the fundamental frequency of level fluctuations,indicating that they are highly related to the main vibration sources.