基于PLC的加热炉仪表控制系统优化研究

Optimization for control system of heating furnace instrument based on PLC

针对加热炉仪表自动控制系统运行的稳定性和实时监控问题,对加热炉控制系统配置、炉膛温度串级调节系统、炉膛温度压力设定、安全连锁系统等方面进行了研究,对加热炉高压鼓风机入口风门开度减小,空气压力降到极限位而引起的加热炉停炉故障以及因液位检测不可靠而导致加热炉底水位增高并淹没炉底部件的事故进行了分析,对高压鼓风机PI自动调节系统和PLC实时监控技术进行了归纳,提出了改进PI调节器和PLC控制程序以及设备异常状态实时监控的方法。研究结果表明,加热炉两台高压鼓风机入口调节器调节灵活方便,性能稳定,不再出现相互干扰问题;加热炉炉底水位监测准确;优化后的加热炉自动控制系统性能稳定、控制精度高、故障发生率低。

Aiming at the problems of the stability of heating,furnace automatic control instruments and real-time monitoring. The problems of heating furnace temperature control system,cascade control system,temperature pressure setting of furnace and safety interlock system were discussed. Some accidents were analyzed,such as the entrance of high-pressure blower was reduced,heating furnace stopped because of low air pressure and the water-level increased due to unreliable water level treasuring which results in the water-level of heating furnace increases. The high pressure blower PI automatic regulation system and PLC real-time monitoring technology were summarized. Some suggestions were given on how to improve PI controller,PLC control program and methods for the abnormal state of equipments in real-time monitoring. The results of study show that the two high-pressure blower inlet regulator are flexible,convenient and stable. No interference problems. The monitoring for the bottom water level of heating furnace and the accident rate are reduced greatly. The automatic control system of heating furnace after being optimized has the characteristics of stability,high precision and low failure rate,which reaches the standards of the design.