A new speed optimization algorithm with application in pickling and rolling line

Xiaoyan Zhu,Qiaohui Jiao,Dianhua Zhang,Li Wang

doi:10.1177/1687814016646502

Abstract

In order to reduce equipment wear and operator pressure, as well as to improve the production efficiency of combined continuous pickling line and tandem cold rolling mill units, four sections’ speeds should be automatically optimized to control the three loopers’ abundance, which include the entry loopers’ entry speed, pickling speed, trimming speed, and tandem cold rolling mill entry speed. According to the optimal speed principle, a new optimization algorithm was proposed based on objective function. In this work, Nelder–Mead simplex method is applied to find the optimal solution by minimizing the objective function. In addition, the calculation of four initial speeds is specified, especially the initial tandem cold rolling mill entry speed. The proposed speed optimization algorithm was successfully applied to a 1450 mm continuous pickling line and tandem cold rolling mill. The acceleration and deceleration are smooth and steady when welding, trimming, or roll changing takes place in practice, the three loopers’ abundance are controlled in suitable range. Results show that the continuous pickling line unit could provide the material in maximum capacity to ensure that the tandem cold rolling mill unit’s production is efficient, and the rolling yield is greatly improved due to the decrease in the number of stops.

Highlights

The combined continuous pickling line and tandem cold rolling mill (CPLTCM) units have multiple advantages such as high rolling yield and production efficiency; savings on labor and construction costs; reduction in energy and roll consumption; and so on
Evaluate the function values through the Nelder–Mead simplex method mentioned in section ‘‘Nelder–Mead simplex algorithm.’’ Before the pickling condition changes, the new li will trigger a new optimal calculation after valuating it to the objective function
The comparison of the production efficiency of three classes is given in Table 3 and it indicates that the production efficiency was greatly improved

Summary

Introduction

The combined continuous pickling line and tandem cold rolling mill (CPLTCM) units have multiple advantages such as high rolling yield and production efficiency; savings on labor and construction costs; reduction in energy and roll consumption; and so on. The middle looper for the storage of the strip is to adapt the running speed between the pickling section and the trimming section. The trimmer cuts the strip to the finished width, and the exit looper for strip storage adapts the running speed between the trimming section and the rolling section. The speed optimization study for the tandem cold rolling mill unit has been well developed, but to authors’ knowledge, there are few reports on the continuous pickling line unit of the CPLTCM. The experience-based setup speed can ensure normal operation of production and meet certain quality requirements, the results may not always be optimal.[5,6] Sometimes, the operators do not find it easy to regulate the four sections’ speeds reliably when welding, trimming, or roll changing takes place. The application result is illustrated through the real data of the actual practice in section ‘‘Results.’’ the conclusions are presented in section ‘‘Conclusion.’’

Objective function design

Results

Conclusion