A Bell Type Furnace Atmosphere Tuning Work Research And Implementation Of The Algorithm

Atmosphere furnace is a nonlinear control-system with large time-delay and inertia, so traditional control strategies can’t respond to temperature changes timely and accurately. At the same time, chopping the voltage wave is used to change power, which leads to high harmonic wave, low power factor, and big grid pollution. Limited by the technology and the cost, the atmosphere furnaces are almost operated on low-automation process. In short, the unreasonable control strategy, behindhand control method, and low degree of automation are the main problems of current atmosphere furnace.Several key technologies on the control of the new atmosphere furnace are studied in this paper. Firstly, Fuzzy PID control strategy is suitable to this nonlinear control system. Control strategy and the fuzzy rules are determined by MATLAB. Secondly, splicing the voltage wave is used to change power with high power factor and low harmonic wave. Such as deciding voltage stages and calculating splice angle, many key issues are analyzed in detail. Lastly, CAN bus is adopt to realize remote monitoring and improve degree of automation. The system hardware structure is described, especially the control board, trigger board and power plate. Besides, the system software algorithms are elaborated, such as AD sampling correction algorithm, zero crossing point capture and lock algorithm, splice the voltage to change power algorithm, fuzzy PID control algorithm and CAN communication algorithm.Energy saving, emission reduction, and integrated automation are our primary goal. Fuzzy PID control strategy, the voltage wave and remote monitoring are applied. Corresponding experimental platform was build. A large number of debugging was done. And last an atmosphere furnace was developed with less energy consumption, high degree of automation and low pollution. The application result validate that this equipment has good performance on changing power, and power is more then20KW. What’s more, its harmonic pollution is low; its most high power factor can of0.95; and it save15%of energy than the original equipment.