Intelligent calculation method for reverse self-decision temperature control of bar water tank based on trial method

Abstract

The present invention is based on the trial-and-error intelligent calculation method for bar water tank reverse self-decision-making temperature control, including the following steps: 1) calculating the temperature distribution of the rolled piece; distribution, and the load of the water supply system; 3) Use the surface temperature value and the temperature difference between inside and outside as the objective function to find out the water tank switch combination that does not cross the boundary; 4) Try to adjust one by one according to the predetermined scale value and take the minimum load of the water supply system as the objective function The size of the water volume valve of each water tank; 5) Calculate the overall time-temperature evolution curve of the rolled piece after the scale of the water volume valve is lowered, compare it with the expected cct cooling path, and exit when the requirements are met. The present invention realizes rapid self-decision-making, large water volume, and rapid cooling of control parameters for each water tank, finely regulates the microstructure and performance requirements according to water cooling, and uses the fastest cooling speed above the formation temperature of martensite to ensure that the rolled piece obtains ferrite and Pearlite, up to standard mechanical properties.

Description

technical field [0001] The invention relates to an intelligent algorithm for controlling and cooling the production of hot-rolled bars, and in particular to an intelligent calculation method for reverse self-decision-making temperature control of a bar water tank based on a trial and error method. Background technique [0002] Hot-rolled bars usually include ordinary bars (rebar) and high-quality special steel bars (such as high-quality carbon structural steel, alloy structural steel, cold heading steel, etc.). In the whole manufacturing process, the management and control of steelmaking, continuous casting, and steel rolling process sections have a decisive impact on product quality in terms of composition, segregation, and organization. Hot-rolled bars are mainly used as structural parts, and more attention is paid to mechanical properties such as yield strength, tensile strength, and elongation. Due to the limitations of welding conditions and the requirements of sudden l...

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Problems solved by technology

[0003] On the one hand, because the surface of the rolled material is relatively internal, the head and tail are relatively central, and the heat exchange conditions at the corners are good, the temperature of the rolled material will inevitably be uneven; on the one hand, during the hot rolling process of the bar, continuous casting, There are fluctuations in process quality during hot delivery, heating, rough rolling, and intermediate rolling, which cause deviations in the temperature of the intermediate rolled piece; on the one hand, cooling equipment, especially nozzles, guide grooves, etc. During the operation of parts, the formed wear will cause uneven cooling. These three aspects together lead to the control of traditional cooling. It is difficult to achieve high precision and stability, and the reliability of the model and system is high.

In addition, it is difficult for production enterprises to achieve complete specialization in production lines, and it is impossible to produce only one type of steel and specification products. It must follow the production plan and task arrangement, carry out fast-paced production scheduling and change system processes, and changes in production products. The core is the change of process system parameters corresponding to steel types and specifications. In order to ensure high production capacity and low cost, it is necessary to quickly formulate process parameters according to new changes in the production line, and control cooling models and algorithms become the key

[0004] At present, the on-site cooling control parameters for hot-rolled bars are still mainly based on empirical methods. Usually, after accumulating a large number of control cooling process values ​​for steel types and specifications, and after about 3 to 5 times of actual steel running on site for debugging, Get the applicable value and use it for a fixed period of time. When the final detection value such as the temperature of the upper cooling bed and the random inspection of the tissue performance fail, then change the parameters. This method is not only time-consuming and laborious, but also has no theoretical guidance. Line production capacity, in addition, based on the Fourier heat transfer principle, through the differential method, the rolling piece temperature calculation software is formed, combined with the formulas of water pressure and water flow obtained from experience or experiments for heat transfer coefficients, to predict temperature changes, this method Compared with the pure empirical method, it has made some progress, but with the change of working conditions, the heat transfer coefficient value is not stable and needs to be updated, which is often not reflected in the software

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