Simulation And Control Of Water Cooling Process Of High Speed Wire

The wire products play an important part in country’s production and building, they are commonly used as architectural material and raw material for drawing and cold machining. As the temperature is a key factor to the wire’s final subminiature structure and mechanical performance when rolling, combine using of temperature controlled rolling and control cooling system can assured the high speed wire rolling mill runs normally, and it also can make the wire products have well surface quality, well mechanical performance and well drawing performance. Along with the development of high speed wire rolling mill, the technology of controlled cooling is being continuously improved and perfected, and its advantage has been showed more and more frequently in practice.The paper fixes on the deep research of the temperature field and control strategy of water cooling process of high speed wire. With taking the water cooling segment after the high speed wire’s rolling as the research object, a physical model is built. According to the characteristic of the research object, the heat transferring of the water cooling process is detailed analyzed, preliminary conditions and borer conditions are explained, and at the same time the heat transfer coefficient is discussed. The temperature distribution and changing curve of the transfer process, rolling process and water cooling process is gained. Using the founded temperature model, the controlled cooling factors such as water flux, water temperature, water cooling time and other factors are analyzed, advices to improve the practical technology is offered.According to the practical condition, particular control strategy for the water process of the high speed wire is designed. The structure of two-level control is set, mathematical model and advanced control thought is realized on level two, and elementary automatic control is executed on the first level. The cooling process of high speed wire is separated into two parts which are first calculate the cooling water flow according to the model and second optimize and revise it according to the measurement of the temperature, so the temperature control effect can be assured. As the water tanks in the product line have different character, different model of water flow’s pre-calculation and water flow’s optimization and compensation are designed. Temperature forecast model is changed according to the heat process of the wire in the model of water flow’s pre-calculation. In the model of water flow’s optimization and compensation, feedback control based on model is chosen for No.1 water tank, and online compensation of water flow according to the feedback measured temperature is chosen for the other four water tanks, and the feedback measured temperature also used to revise the temperature forecast model.The particularity of the delay problem of the system is analyzed, and it is found that the reason of the delay problem is that adjusting time is longer than wire’s running time. In order to resolve the problem, the paper focuses on the temperature’s forecast, improve the precision of the temperature model to know the temperature’s change in advance, then the time used for adjusting can be saved.In order to improve the quality of elementary automatic control system on level one, tuning method of PID controller based on fuzzy inference is used, the control process is departed into two states based on fuzzy inference, which are transition and stabilization, and the proportion parameter, the integral parameter and the differential parameter of the PID controller are got distinguishingly from the two fuzzy controller.