Laminar Flow Cooling Of Hot Rolled Strip And Its Optimization

The control accuracy of the coiling temperature of the hot striplaminar cooling system affects the strip's structure and mechanicproperties directly, which is the crucial factor to guarantee the betterquality and flatness of strip. So the control on hot strip coiling plays animportant role in hot strip production. It is of great practical importanceto analyze and study the control technical. With the laminar coolingsystem of our country as the background, this dissertation makes a deepstudy from control strategy on how to improve the accuracy of the coilingtemperature and equality of temperature on the same strip. Detailed worksare as follows.As the mathematic model of hot strip laminar cooling system isbased on the theory of calorifics, so the paper first analyze the models ofheat transfer, and particular analyze the mathematic model of the processof this hot strip laminar cooling system. This mathematic model mainlyincludes water cooling model and air cooling model, its calculatedprecision influences the last effect of control cooling. So the proper heattransfer model is very important thing which can improve the accuracy ofthe coiling temperature.Study and analyze the laminar cooling control strategy of a hot millplant in our country, and particular analyze the all functions of controlstrategy. The paper has established a simulate system which can offer anexperiment tool to improve the control strategy and the model.Indicate that one reason of the coiling temperature is not accuratebecause there exist time-delay in laminar cooling control system. Use theSmith-predictor to overcome the influence of the pure time-delay. Withthe strong robust of fuzzy control, the paper design a Fuzzy-PI controllerbased on the Smith-predictor to improve the feedback control of the thehot strip laminar cooling system. The result has proved that the methodcan improve the accuracy of the coiling temperature.Point out the major reason why coiling temperature isn't accurateand temperature equality on the same strip isn't good is the temperatrue model is not accurate enough. ANN has the ability to analytic nonlinearcomplex process, so the paper makes a study on the ANN, adoptimproved BP neural network to predict the strip's coiling temperature.Theresult of the simulation shows that this method is very effective.