台车式退火炉PLC控制系统的优化设计

摘要

针对原台车式退火炉控温系统超调大、信息监控实时性差以及运行可靠性低等问题,应用西门子S7-300 PLC控制系统进行优化设计,包括温度控制、燃烧过程控制、压力及电气联锁控制、上位机管理系统等.温度是系统控制中的关键参数,根据专家的经验知识,通过PLC程序对控温算法进行优化设计.同时利用STEP7软件指令自主研发程控脉冲燃烧分频程序,保证控温的精确性和在炉内分布的均匀性.实际运行结果表明,系统性能稳定、控温精度高、硬件成本低,很好地满足了工艺需求.%Aiming at the demerits of the temperature control systems for existing trolley type annealing furnace, e. g. , large overshoot, poor real time monitoring performance, and low operation reliability, etc. , by adopting Siemens S7-3OO PLC the optimization design of the control system is carried out, including temperature control, combustion process control, pressure and electric interlock control and host computer management system, etc. Temperature is the critical parameter in system control, in the design, the experience and knowledge of experts is used; the temperature control algorithm is optimally designed through PLC program. In addition, with help of STEP7 software commands, programmable controlled pulse combustion frequency divider program is developed to ensure the accuracy of temperature control and the uniformity of temperature distribution in furnace. The result of practical operation indicates that the system features good stability, high temperature control accuracy, low cost of hardware, and meets technique requirements.