毕业设计双级反渗透水处理设备电气控制系统设计.doc

摘 要 现今社会人民的生活水平的逐渐提高，人们对水的质量要求也越来越高。如今在很多领域都需要纯度极高的水，如固态电子器件、厚膜和薄膜电路、印刷电路、真空管等的制作都要使用超纯水PLC的发展及显而易见的优点, 使其在工业生产过程控制中得到了广泛的应用, PLC控制系统具有安全可靠、功能完善、操作简便等优点从而大大的提高了水处理的自动化水平。本文主要介绍，对其自控系统的控制方式，设备选型Abstract Nowadays peoples living standards has gradually improved the quality of water is bound to put forward higher requirements. Today, all fields are required high purity water. Such as solid state electronic devices, thick film and thin film circuits, printed circuits, vacuum tubes also have to use ultra-pure water production. With the development of PLC and the obvious advantages of the process control in industrial production has been widely applied, PLC control system with safe, reliable, functional, convenient, and accurate, which greatly improved the water level of automation. This paper introduces the development of two reverse osmosis water treatment system and its background, its automatic control system of control, equipment selection are described. In this paper, two reverse osmosis water treatment system, the main circuit diagram. This device mainly consists of two parts .First, raw water pretreatment, municipal tap water into the original water tank, through the pretreatment system, the original water impurities has effectively removed. Second, two reverse osmosis, two reverse osmosis is the process of penetration phenomena in concentrated solution, Using pressure to remove impurities, resulting in high purity water to meet the industry demand and other aspects of life. Key Words：Reverse Osmosis；Automatic control；PLC 目 录 摘 要 I Abstract II 1 引言 1 1.1 设计背景 1 1.2 反渗透系统发展概况 3 2 双级反渗透系统工艺流程 5 3 双级反渗透水处理系统硬件设计 8 3.1 可编程控制器PLC系统模块设计 8 3.1.1 PLC简介 8 3.1.2 本系统PLC选型 11 3.1.3 PLC输入、输出电路 11 3.2 控制电路设计 13 3.2.1 变频器简介 13 3.2.2 变频器的选型 14 3.2.3 SPWM控制技术 15 3.3 主电路设计 16 4 双级反渗透自动控制原理 17 4.1 双级反渗透装置自动控制 17 4.2 控制说明 18 结 论 19 参 考 文 献 20 附录A 工艺流程部件详细数据（调研报告） 21 致 谢 23 1 引言 反渗透技术是当今最先进和最节能有效的膜分离技术。其原理是在高于溶液渗透压的作用下，依据其他物质不能透过半透膜而将这些物质和水分离开来。由于反渗透膜的膜孔径非常小（仅为10A