The Design And Implementation Of Heat Treatment Furnace Multi-point Temperature Control System

Large resistance furnaces are very important equipments for the thermal treatment. Because of its size, high heating temperature and working conditions of high complexity, its precise temperature control is quite difficult. In this paper, focusing on the HSR-1600-8 resistance furnace, the design and implementation of a rational and effective control system for its precise control is of great realistic meaning and applied value, because it can improve the quality of heat treatment and save energy.Firstly, this paper briefly introduces China's resistance furnace of heat treatment industry, as well as the development of temperature control status, analyzes the resistance furnace temperature traditional control methods and its problems. On this basis in accordance with the structure of the resistance furnace and heat treatment process requirements, this paper designs the overall structure of the control system besides hardware and software detailed design and implementation. This system uses 16 ecumenical Xiamen Intelligent Instrument AI-518P as a site controller, uses Dell work station as host computer, uses RS-485 communication bus for connection, uses PC software King view to implement system control algorithm,monitoring, alarm, data log and other functions.Secondly, in connection with structure of resistance furnace and the characteristics of generalized predictive control system, we put up the methods of structure identification and parameters identifications for multivariable CARIMA model, after determining the appropriate samples and input data, we use the recursive least squares method to identify the model parameters, choose multivariable generalized predictive method as the main control algorithm. At last,we design the heat treatment furnace multi-point temperature control algorithm.Finally, using the Matlab system we carry out simulations to study the possible failure of fuse wire, thermocouple damages, as well as PC communication interruptions, etc. The simulation results and actual operating data show that the system can process in accordance with the requirements of the heat treatment, and achieve the desired results.