鋼板軋延模擬暨厚度控制

Simulation of Hot Strip Mill and Gauge Control

洪敏倚(Min-Yi Hong)

指導教授 ： 陳傳生

元智大學/工程學院/機械工程學系/碩士(1998年)

摘要

本文的目的是對於在軋鋼生產線中的精軋區（約七座串列四重式軋機），鋼帶軋延時的初始參數設定及調節系統作動時序作瞭解及分析。在初始參數設定上，最重要的莫過於藕合兩座軋機變化的工輥轉速。在轉速的設定上，會是一站比一站快；因為在軋延過程中，鋼帶受到工輥旋轉及輥隙比入口厚度小的緣故，削減鋼帶厚度的效應造成鋼帶於進口處受到往後的推擠，於出口處受到往前的推擠。倘若每站的輥速是相同的，那在前站的出口及後站的入口間，所造成的速度差將會很大，難以調節。不過，縱使輥速一站比一站快，鋼帶於前站出口速度仍然必須要微小於後站入口速度，如此，產生的堆積張力才可以調節。
在精軋區中，主要有三個調節系統，分別是液壓厚度調節系統、張力調節系統以及工輥轉速調節系統。液壓厚度調節系統於每站鋼帶進入後即啟動，調節因為鋼帶的塑性變形產生軋機剛性及工輥和背輥間的應力變化，所造成的輥隙變化，以維持理想的輥隙。張力調節系統於鋼帶存在於站和站之間時即啟動，調節因工輥慣性大，無法短時間調節站間輥速匹配的誤差，在作動的速度上，儘量和液壓厚度調系統相近，避免造成鋼帶質量流的不匹配。至於工輥轉速調節系統除了第一站是在鋼帶進入第二站時啟動外，其餘的就在鋼帶存在站和站之間數秒後，再啟動。其原因在於工輥慣性大，如果在鋼帶進入次站時即啟動，則在輥速匹配的同時，造成此站鋼帶的出口速度會小於次站的入口速度，形成拉伸張力，無法由張力調節系統來補償。
在找出表示軋延現象的計算公式後，經由和調節系統間的整合，建構一個簡單非線性的軋延模型，即三座串列四重式軋機，作軋鋼離線模擬，方便我們對於初始參數的分析及選用，進而作為線上模擬的參考資料。

關鍵字

液壓厚度調節系統 ； 張力調節系統 ； 工輥轉速調節系統 ； 簡單非線性的軋延模型 ； 軋鋼離線模擬

並列摘要

Finishing rolling (contain seven stands, 4-high mill) is the part of the whole rolling process, and it also reflects the strip final quality all the time. Hence, we are interesting on the thickness variance of the finishing rolling, and try to simulate the situation of the strip when it flows in finishing rolling mill. Before rolling hot strip, the initial set-up value of mills and the time of regulators operation are the most important things that we need to decide.
The most important set-up value is the speed of the work roller because it couples two adjacent rolling mills, and relates the entry and exit speed of strip to the mill. Between two mills, one is exit speed and another one is entry speed, and the two have speed difference, and cause the tension stress that is always positive when the strip is between two mills. The positive means the speed difference after integral is positive because the tension regulator only can regulate the positive tension stress.
There are three main regulators in rolling process, hydraulic gauge, tension and main motor speed regulators. The hydraulic gauge and tension regulators start to regulate errors when the strip arriving at the next mills, and the main motor speed regulator at the first stand starts as the tension regulator, but the other main motor speed regulators start after several seconds when the strip arriving each mill. The reason is the large inertia of the main motor. In order to keep positive tension stress, so the others start after several seconds.
After we getting nonlinear equations about rolling, integrate with regulators to develop three hot mill stands simulators, and let us getting the results that initial set-up value how to infect the rolling strip. Therefore, we may use the initial set-up value that showing good performance of simulators to real hot mill stands, and decrease the danger of guessing initial set-up value, and lower the cost of rolling strip.

並列關鍵字

HASH(0xd94ab50)

參考文獻

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10） A. Lage, et al., “Modeling and Simulation of a Hot Strip Rolling Mill”, Industrial Electronics, Control and Instrumentation, Vol.3, pp.2017-2022, 1994.