To the solution of the problem of control of metal temperature in ACS TP of methodical furnaces

Introduction. In the context of increasing requirements for the quality of metal heating before rolling, the task of improving the automated control systems for the technological process (APCS) of heating furnaces is quite urgent. Purpose of the study. To establish the most rational methods and procedures for solving the problem of metal temperature control within the framework of the automated process control system of methodical furnaces. Materials and methods. The analysis and generalization of literature data on the problem is carried out. Acceptable technical structures of control subsystems are determined by means of a physical-technical approach. Results. A system is proposed that includes both a sensor for the temperature of the masonry or the temperature of the working space in the zone, and two pyrometers, one of which is connected to the metal located at the beginning of the zone, and the second - at its end section. Such a system, firstly, will determine the weighted average temperature of the metal in the zone, which is very important for the high-quality operation of automatic control systems (ACS) of the zone temperature regime, and, secondly, the systematic measurement error will be eliminated using a temperature sensor masonry or working space temperature. The reasons why it is preferable to use a radiation temperature sensor of the working space are indicated. Such corrected signals from the pyrometers can be used not only in the automatic control system of the temperature regime of the furnace zones, but, for example, to adapt the used heating models. The structure of the mathematical model is substantiated, suitable for the feedback loop of the process control system, the expediency of describing the heating of slabs by a one-dimensional heat conduction equation in combination with the zonal method of calculation and experimental tuning of external heat transfer models is shown. The characteristics of various algorithms for controlling the temperature fields of slabs are given. The admissibility of a conventionally symmetric description of the heating process is noted, due to the possibility of such a choice of settings (tasks) of the temperature regulators of the lower zones of the methodical furnaces, in which the dynamics of the average mass temperatures of the upper and lower halves of the slab will almost completely coincide. Conclusion. The results of the work can be used in the development and improvement of the automated process control system of heating furnaces.