Gas Nitriding Nitrogen Furnace Temperature Control System Simulation Technology

This paper is based on the problem of technique improvement of gas-nitriding furnace. According to the demand of the technology of gas nitriding, the author firstly put forward total demand analysis and systematic model-making for gas-nitriding furnace's temperature control system with UML in order to definite the temperature control system's functional requirement and the interaction of each object in this system on the basis of this idea. It's thought that the key step for realizing the temperature control system is the analysis and the design of the PID controller. Considering that the gas-nitriding furnace has significant temperature lag, the author initially pointed out the opinion of realizing the system of temperature control by PID controller with pure lag compensation and then designed the parameter of PID controller with pure lag compensation and ordinary PID controller by MATLAB6.5. Furthermore , the two temperature control system formed by two different PID controller are simulated and compared based on the MATLAB6.5's Simulink circumstances. The result suggests that the robust of the PID control system with pure lag compensation is better than that of the ordinary PID control system. In order to decrease the over-adjusting in temperature and transaction time, a multi-model selector was provided to different scenarios of ascending temperature to make this system be simulated under Simulink's circumstances. The result of simulation demonstrated that the effect of the system temperature control with model selector is superior to that of the system with PID controller or with pure lag compensation. The research works in this simulation holds an active reference and can be used to improve the technology in the temperature control system of the traditional industrial electric-furnace in which The only method of temperature control is on and off. Finally, as an attempt, an tiny database on nitrogen technology is developed for small industry as the technician's reference.