ABOUT DESIGN AND INSTRUMENTAL CONTROL OF QUALITY OF HEATING AND HEAT TREATMENT OF METAL IN FURNACES
DOI:
https://doi.org/10.14529/met200407Keywords:
quality of metal heating and heat treatment, control of temperature drop across the cross section, automated control system, control algorithm settings, permissible error of surface temperature measurement, heat flux densityAbstract
Introduction. In conditions of increasing requirements for the quality of metal heating before rolling or during its heat treatment, the task of creating and improving the algorithmic support of automated process control systems (ACS TP) of heating and thermal furnaces is quite relevant. Aim. The solution to the problem of controlling the temperature drop over the cross section of a metal when it is heated before rolling or during heat treatment is considered. Materials and methods. An analysis of the literature on the problem. A generalization of the results of previous work is carried out both for cases of exposure at a constant temperature of the working space, and at a constant surface temperature of the workpiece, as well as for the case of heating massive bodies of arbitrary shape. Results. It is shown that the solution to the control problem can be reduced either to measuring the current density of the heat flux inside the metal, or to measuring the temperature difference between the furnace and the surface of the slab. The influence on the structure of control algorithms of various features of the real aging process is investigated. The solution of the control problem for the case of massive bodies of arbitrary shape is given. Relations for control are obtained, similar to control algorithms for ingots and slabs. A method for tuning control algorithms to a real process according to current measurements in a regular mode is indicated. It has been established that for the case of symmetric or one-sided heating of slabs in methodological furnaces, it is sufficient to measure the temperature of only one of the surfaces for adjustment, while asymmetric heating requires the measurement of the temperatures of both surfaces. For the case of holding cold-rolled strip rolls in bell-type furnaces, it is necessary to measure the temperature at three radially different points of the base of the lower roll using contact thermocouples. After adjustment, for control in any case, it is enough to measure the temperature at only one point on the surface. The influence of errors in measuring the surface temperature of a metal on the accuracy of control algorithms and on the accuracy of estimating the maximum temperature difference over its cross section is studied. The implementation options for control algorithms in an industrial environment are given. Conclusion. The results of the work can be used in the development and improvement of the algorithmic support of automated process control systems for heating and thermal furnaces.References
Shakola Yu.A., Kostogryzov V.S., Goldfarb E.M. Sposob opredeleniya prodolzhitel'nosti vyderzhki slitkov v nagrevatel'nykh kolodtsakh [A method for determining the exposure time of ingots in heating wells]. Patent USSR, no. 144866, 1962.
Goldfarb E.M. Teplotekhnika metallurgicheskikh protsessov [Thermotechnology of metallurgical processes]. Moscow, Metallurgy Publ., 1967. 440 p.
Revun M.P., Grankovsky V.I., Baybuz A.N. Intensifikatsiya raboty nagrevatel'nykh pechey [Intensification of the operation of heating furnaces]. Kiev, Technique Publ., 1987. 136 p.
Kostogryzov V.S., Lviv S.G., Miroshnichenko M.V., Morekhina N.M. [A method for controlling the degree of ingot heating over a section]. In the book: Gladkikh V.I. Industrial Furnace, 1979, pp. 53–60. (in Russ.)
Wick H.-J., Greiff H. Monitoring of the degree of warming of blocks in deep furnaces with the extended Kalman filter. METEC'84: 2 Int. Walzwerkkongr., Dusseldorf, June 22–28, 1984, vol. 2. Dusseldorf, 1984, F 3/1–F 3/13.
Barr P.V., Burgess A.W. A.P.C. computer model for the slab reheating furnace. CIM Bull., 1989, 02, no. 926, pp. 116–117.
Klima R., Kuck A., Sucker D. Ein einfaches mathematisches Modell für die Wärmeübertragung und seine Anwendung auf Durchlauf-Warmofen. Gas Warme Int., 1983, vol. 32, no. 4, pp. 138–143.
Revun M.P., Zinchenko V.Yu. [Promising directions for improving the thermal work of heating and thermal chamber furnaces]. Metallurgicheskaya teplotekhnika: sb. nauch. trudov Natsional'noy metallurgicheskoy akademii Ukrainy [Metallurgical heat engineering: Collection Scientific Proceedings of the National Metallurgical Academy of Ukraine]. Dnepropetrovsk, “PP Grek OS.” Publ., 2006, pp. 294–302. (in Russ.)
Specht Eckehard, Alt Rudiger. Temperature compensation in heated solids. Steel Res., 1990, vol. 61, no. 11, pp. 569–575.
Lukin S.V., Kibardin A.N., Sidorenkova S.E., Kochkin A.A. [Optimization of heating and temperature control of slabs during hot planting in heating furnaces]. Vestnik Cherepovetskogo gosudarstvennogo universiteta [Bulletin of the Cherepovets State University], 2016, no. 3, pp. 7–11. (in Russ.)
Panferov V.I. [About the indirect control algorithm and the features of the temperature fields of massive bodies during exposure at a constant surface temperature]. Izv. vuzov. Chernaja metallurgija [The News of High Schools. Ferrous Metallurgy], 1985, no. 4, pp. 93–97. (in Russ.)
Panferov V.I. [To control and analysis of temperature fields of massive bodies during the leveling period at zero heat flux through the surface]. Izv. vuzov. Chernaja metallurgija [The News of High Schools. Ferrous Metallurgy], 1986, no. 3, pp. 123–126. (in Russ.)
Panferov V.I. [About some properties and about the algorithm of indirect control of temperature fields of massive bodies during the exposure period at a constant furnace temperature]. Izv. vuzov. Chernaja metallurgija [The News of High Schools. Ferrous Metallurgy], 1985, no. 6, pp. 114–116. (in Russ.)
Panferov V.I. [To control the temperature fields of massive bodies during the exposure period at a constant furnace temperature]. Izv. vuzov. Chernaja metallurgija [The News of High Schools. Ferrous Metallurgy], 1986, no. 7, p. 157. (in Russ.)
Panferov V.I. [Algorithmization of quality control of metal heating in furnaces]. Izv. vuzov. Chernaja metallurgija [The News of High Schools. Ferrous Metallurgy], 1989, no. 4, pp. 140–144. (in Russ.)
Kartashov Je.M. Analiticheskie metody v teorii teploprovodnosti tverdyh tel [Analytical methods in the theory of the thermal conductivity of solids]. Moscow, High School Publ., 2001. 550 p.
Panferov V.I. [Adaptive quality control systems for metal heating in furnaces]. Izv. vuzov. Chernaja metallurgija [The News of High Schools. Ferrous Metallurgy], 1990, no. 7, p. 110. (in Russ.)
Thayts N.Yu. Tekhnologiya nagreva stali [Steel heating technology]. Moscow, Metallurgizdat Publ., 1950. 450 p.
Pryadkin L.L. [Automation of continuous heating furnaces of rolling production]. Stal' [Steel], 1986, no. 2, pp. 103–106. (in Russ.)
Kehlbery E. Optimization of reheat furnace operation. ABB Rev., 1992, no. 3, pp. 13–18.
Parsunkin B.N., Panferov V.I. [Control of metal heating]. Izv. vuzov. Chernaja metallurgija, 1981, no. 10, pp. 127–129. (in Russ.)
Panferov V.I., Gelfand I.M., Kulachenkov G.P., Torchinsky E.M. [Development of an automated control system for annealing rolls of cold rolled tape]. Resursosberegayushchiye i ekologicheski chistyye tekhnologii v metiznom proizvodstve: sb. nauch. tr. MM SSSR.[Resource-saving and environmentally friendly technologies in hardware production: Sat. scientific Proceedings of the MM of the USSR]. Moscow, Metallurgy Publ., 1991, pp. 53–57. (in Russ.)
Panferov V.I. [Some problems of automation of hoods]. Izv. vuzov. Chernaja metallurgija [The News of High Schools. Ferrous Metallurgy], 2002, no. 4, pp. 42–45. (in Russ.)
Parsunkin B.N., Andreev S.M., Akhmetov T.U., Akhmetova A.U. [Investigation of the accuracy of the method for monitoring the temperature state of heated continuously cast billets before issuing]. Elektrotekhnicheskiye sistemy i kompleksy [Electrotechnical systems and complexes], 2014, no. 4 (25), pp. 28 – 30. (in Russ.)
Andreev S.M. Teoreticheskiye osnovy i prakticheskaya realizatsiya energosberegayushchego optimal’nogo upravleniya nagrevom nepreryvnolitykh zagotovok v pechakh prokhodnogo tipa: dis. d-ra tekhn. nauk [Theoretical foundations and practical implementation of energy-saving optimal control of heating continuously cast billets in continuous furnaces. Doct. sci. diss.]. Magnitogorsk, 2019. 310 p.
