PLC在温控系统中的应用

Application of PLC in temperature control system

文章详细介绍了一种PLC对设备进出水温差进行控制的方法。PLC作为核心控制单元,负责对温度信号的采集,通过A/D转换将温度的模拟信号转换为线性输出的数字信号。变频器的运行频率根据进出水的温差信号的变化而变化,并通过D/A转换模块,将数字信号转换为模拟电压信号输出,模拟电压信号来控制变频器的输出频率。通过变频器驱动冷冻泵运行,最终达到缩小进出水温差的目的。

This paper introduces the method of PLC to control the temperature difference of water. As the core control unit, PLC responsible for the temperature signal acquisition, through the A/D conversion to convert the analog signal to digital signal for linear output. The operation frequency of the inverter will change, according to temperature difference of the water,and through the D/A conversion module, the digital signal is converted to analog voltage output signal. The analog voltage output signals to control the inverter output frequency. Through the inverter to drive the frozen pump operation, reach the purpose for reducing temperature difference of water.