【正文】 sign, operating principles and the basic principles of the design of PLC control system and the steps to illustrate the application of PLC in the sewage treatment process. First design of electrical control and automatic control circuit according to the sewage treatment requirements, including start and stop equipment, status signal fault signal, and signal acquisition, the final design of PLC control system in accordance with the process requirements, including the selection of the PLC, the system allocation of resources, as well as the preparation of the PLC program in accordance with the sewage treatment process. Key words: sewage treatment the PLC process 河南理工大學畢業(yè)設計（論文） III 目 錄 1 緒 論 ...................................................................................................................................... 1 課題的背景 ....................................................................................................................... 1 工業(yè)污水處理的國內外現(xiàn)狀 ........................................................................................... 2 課題主要設計的內容 ....................................................................................................... 3 2 工業(yè)污水處理控制系統(tǒng)總體介紹 ........................................................................................ 4 工業(yè)污水處理基本概念 ................................................................................................... 4 常用的工業(yè)污水處理工藝 .............................................................................................. 4 本設計系統(tǒng)工業(yè)污水處理工藝及描述 ........................................................................... 9 工業(yè)污水處理系統(tǒng)控制形式 ......................................................................................... 10 工業(yè)污水處理系統(tǒng)的功能要求 ..................................................................................... 11 信號輸入 .................................................................................................................. 11 控制輸出信號 .......................................................................................................... 12 3 硬件系統(tǒng)配置 ...................................................................................................................... 13 主要組成部分 ................................................................................................................. 13 電氣控制系統(tǒng) ................................................................................................................. 14 工業(yè)污水處理系統(tǒng)的工作原 理 ..................................................................................... 15 控制系統(tǒng)總體框圖 .................................................................................................. 15 工作過程 .................................................................................................................. 15 工業(yè)污水處理系統(tǒng)主電路設計 .............................................................................. 16 PLC 的選型 ............................................................................................................... 16 PLC 的選擇 ......................................................................................................... 16 S7200 PLC 概述 ..................................................................................................... 17 PLC 的 I/O 資源配置 ..................................................................................................... 18 數(shù)字量輸入部分 ...................................................................................................... 18 數(shù)字量輸出部分 ...................................................................................................... 18 模擬量輸入部分 ...................................................................................................... 19 模擬量輸出部分 ................................................................................................... 19 其他資源配置 ................................................................................................................. 20 接觸器選型 .............................................................................................................. 20 變頻器簡介 .............................................................................................................. 21 河南理工大學畢業(yè)設計（論文） IV 變頻與變壓 (VVVF)原理 ......................................................................................... 21 變頻調速的基本原理 .............................................................................................. 22 變頻器選型 .............................................................................................................. 23 變頻器參數(shù)設置 ...................................................................................................... 23 電動機的選 型 .......................................................................................................... 24 液位差計 .................................................................................................................. 25 溶解氧儀 .................................................................................................................. 25 4 軟件系統(tǒng)設計 ...................................................................................................................... 27 總體流程設計 ................................................................................................................. 27 手動模式 .................................................................................................................. 27 自動模式 .................................................................................................................. 28 曝氣過程控制的任務 ..................................................................................................... 37 氯氣投加環(huán)節(jié) ................................................................................................................. 37 絮凝劑投加環(huán)節(jié) ......................