基于PLC控制的加热炉温度控制系统设计

学科代码：080601 学 号：061401010055

贵 州 师 范 大 学（本 科）

毕 业 设 计

题 目：基于PLC控制的加热炉温度控制系

统设计 学 院：机械与电气工程学院 专 业：电气工程及其自动化 年 级：2006级 姓 名：吴长胜

指导教师：吴舰

完成时间：2010年5月1日

基于PLC控制的加热炉温度控制系统设计

摘要

温度控制系统广泛应用于工业控制领域，如钢铁厂、化工厂、火电厂等锅炉的温度控制系统，电焊机的温度控制系统等。加热炉温度控制在许多领域中得到广泛的应用。这方面的应用大多是基于单片机进行PID 控制, 然而单片机控制的DDC 系统软硬件设计较为复杂, 特别是涉及到逻辑控制方面更不是其长处, 然而PLC 在这方面却是公认的最佳选择。加热炉温度是一个大惯性系统，一般采用PID调节进行控制。随着PLC功能的扩充在许多PLC 控制器中都扩充了PID 控制功能, 因此在逻辑控制与PID控制混合的应用场所中采用PLC控制是较为合理的。本设计是利用西门子S7-300PLC控制加热炉温度的控制系统。首先介绍了温度控制系统的工作原理和系统的组成，然后介绍了西门子S7-300PLC和系统硬件及软件的具体设计过程。

关键词：西门子S7-300PLC，PID，温度传感器，固态继电器

The application of Siemens S7-300 in temperature control

Abstract

Temperature control system has been widely used in the industry controlled field，as the temperature control system of boilers and welding machines in steel works、chemical plant、heat-engine plant etc. Heating-stove temperature control has also been applied widely in all kinds of fields .The application of this aspect is based on SCM which is making the PID control, yet the hardware and software design of DDC system controlled by SCM is somewhat complicated , it’s not an advantage especially related to logic control, however it is accepted as the best choice when mentioned to PLC.

The furnace temperature of heating-stove is a large inertia system，so generally using PID adjusting to control. With the expanding of PLC function, the control function in many PLC controllers has been expanded. Therefore it is more reasonable to apply PLC controlling in the applicable fields where logical control and PID control blend together. The design has utilized the control system with which Siemens S7-300 PLC control the temperature heating-stove. In the first place this paper presents the working principles of the temperature control system and the elements of this system. Then it introduces Siemens S7-300 PLC and the specific design procedures of the hardware and the software.

Key words：Siemens S7-300 PLC，PID，temperature pickup, solid state relay