以PLC 作控制器，結合溫度變送器、液位變送器以及晶閘管和變頻器等執行元件，組成電熱鍋爐溫度-液位雙回路控制系統，詳細介紹了控制系統的構成原理、硬件配置和軟件控制流程。系統中的PID 調節功能用PLC 集成的PID 指令實現。在實驗室進行了系統
調試，收到了比較滿意的控制效果。系統安全、可靠、易于實現、維修方便。
關鍵詞：PLC；電熱鍋爐；PID；雙回路控制
Double-loop control system of electrothermal boiler’ s temperature and level
REN JUNJIE LI HONGXING LI YONGXIA ZHANG YINONG (Beijing Union University，Beijing，China) Abstract: Based on PLC, combined with temperature transmitter, level transmitter, thyristor and frequency converter, a double-loop control system of electrothermal boiler’ s temperature and level is composed。The structure and control principle are introduced in details. The hardware configuration and software control flowchart are also described. The PID function is achieved with the PID instruction integrated in PLC. The system is debugged in the laboratory and a satisfactory control can be received.
Key words： PLC Eectrothermal boiler PID Double-loop control