供暖气水恒压补水控制系统.doc

内蒙古科技大学 本科生毕业设计说明书（毕业论文） 题 目：供暖气水恒压补水控制系统 学生姓名：牛军 学 号：200540501320 专 业：自动化 班 级：自05-3 指导教师：任彦 供暖气水恒压补水控制系统 摘 要 工业锅炉属于高温、高压设备,其安全性必须放在首位。在锅炉运行时,必须保证补水压力保持在给定恒压点附近，以及把锅炉的热量及时的传送出去。本文对系统采用了PLC控制的变频调速控制方式。传感器实时的把管网的压力和锅炉的出入口温度传送给PLC,经过PLC内部的PID运算然后控制补水部分和循环部分的变频器，实时的控制管网的压力和锅炉的温度。 设计利用PLC和变频器实现自动恒压补水的控制系统。采用PLC内置的PID调节器，选用两台变频器分别控制补水部分的水泵和循环部分的水泵。补水部分用两个水泵，一备一用。循环部分用也用两个水泵，一备一用。 基于PLC和变频器技术的恒压供水系统的组成和工作原理，给出了控制系统的硬件组成和软件设计方案。 由于系统采用了可编程控制器与变频调速技术，因此具有很高的可靠性，抗干扰能力强，节能效果明显。 关键词：PLC；变频器；恒压补水；PID；锅炉； Constant pressure for water supplied control system used for Heating Abstract Industrial boiler is classified to high temperature and high pressure equipment, so its safety must be put prime consideration. When the boiler runs, water supplied pressure should be maintained in the vicinity of a given constant pressure, moreover, the thermal energy generated in the boiler should be sent away as soon as possible. This dissertation adopts PLC control frequency conversion to drag motors, The sensor transfers the temperature of the boiler and the pressure of the tunnel to the internal PLC in a real-time way, after PID calculation by PLC, PLC controls the frequency convertor contained in water supplied system and water circulation system , which controls the pressure of the tunnel and the temperature of the boiler. This design utilizes PLC and frequency convertor automatic to actualize the automatic constant pressure water controlled system. The system adopts the PLC built-in PID adjustor and chooses two frequency convertor to control the pump of the water supplied part and the pump of water circulation part respectively. The water supplied part comprises two water pumps, one for utilization and the other for accident. The dissertation based on PLC and frequency convertor technology and introduced the composition and the theory of constant pressure water supplied system, it also introduced the hardware and software design proposal. Since the system uses a programmable l