【正文】 efficiency, and effectively control the mother liquor of salt content and salt content. To overe the centrifuge operating speed regulation of single, higher failure rate of defects. This paper mainly discusses the centrifuge and the work principle of PLC, and the application of ladder diagram PLC preparation procedures, to PLC logic control program design method and the realization process, control system and implementation method have been explained. A thorough understanding of the working principle of centrifugal and fault conditions, the system requirements and parameters analysis, using the PLC of its own with a logical calculations and data processing functions, realizes the centrifuge control system design. The hardware of the system has the advantages of simple structure, convenient operation, good visualizability, safe and reliable control, stable operation, high control precision, with other caustic soda production system of centrifuge control system has several advantages, economic and practical, has the broad application prospect. Key Words： Production of caustic soda ； PLC； Centrifuge ； program design 北華大學畢業(yè)設(shè)計（論文 ） 1 目 錄 摘 要 ........................................................................................................................ 1 Abstract ........................................................................................................................... 2 目 錄 ........................................................................................................................ 1 引 言 ........................................................................................................................ 1 1 緒 論 ....................................................................................................................... 2 燒堿系統(tǒng)定義及其發(fā)展情況 ............................................................................ 2 氯堿工業(yè)的定義 ..................................................................................... 2 離子膜法電解技術(shù)的國內(nèi)發(fā)展情況 ....................................................... 6 現(xiàn)階段離子膜法電解技術(shù)裝備的世界發(fā)展動向 .................................... 8 離心機簡介 ....................................................................................................... 8 離心機的定義 ......................................................................................... 8 離心機的工作原理 .................................................................................. 8 離心機的由來與發(fā)展 .............................................................................. 9 可編程控制器 ................................................................................................. 10 可編程控制器的產(chǎn)生 ............................................................................ 10 PLC 的定義及工作原理 ........................................................................ 11 PLC 的功能與特點 ................................................................................ 12 PLC 的發(fā)展歷史、現(xiàn)狀及其趨勢 ......................................................... 14 西門子 S7300PLC 簡介 ....................................................................... 16 控制系統(tǒng)的現(xiàn)狀及發(fā)展 .................................................................................. 19 工業(yè)控制系統(tǒng)的現(xiàn)狀 ............................................................................ 19 工業(yè)現(xiàn)場的控制系統(tǒng)的發(fā)展 ................................................................ 20 2 離心機控制要求 ....................................................................................................... 21 3 PLC 控制系統(tǒng)的硬件設(shè)計 ........................................................................................ 23 PLC 的選型 ..................................................................................................... 23 PLC 容量估算 .................................................................................................. 24 北華大學畢業(yè)設(shè)計（論文 ） 2 I/O 點數(shù)的估算 ...................................................................................... 24 PLC 存儲器容量估算 ............................................................................ 24 I/O 模塊 的選擇 ...................................................................................... 25 分配輸入 /輸出點 .................................................................................. 26 4 PLC 控制系統(tǒng)的軟件設(shè)計 ........................................................................................ 29 工藝要求 ......................................................................................................... 29 主機和油泵的控制 ................................................................................ 29 電磁閥的控制 ....................................................................................... 29 （ 1）手動控制 ............................................................................................... 29 （ 2）自動控制 ............................................................................................... 29 PLC 控制系統(tǒng)順序功能圖 .............................................................................. 30 PLC 控制系統(tǒng)程序 .......................................................................................... 31 觸摸屏仿真界面 ............................................................................................. 41 結(jié) 論 ...................................................................................................................... 43 參 考 文 獻 ................................................................................................................. 44 致 謝 ...................................................................................................................... 45 北華大學畢業(yè)設(shè)計（論文） 1 引 言 近年來 ,我國的氯堿工業(yè)發(fā)展十分迅猛 ,原有氯堿企業(yè)紛紛擴大生產(chǎn)能力 , 同時一些新的企業(yè)也相繼誕生 ,產(chǎn)能快速提升 ,燒堿生產(chǎn)能力已從 1998 年的 745 萬 t/年增加到 2020年的 1470 萬 t/年 ,7 年期間翻了一番 ,從而使我國在燒堿產(chǎn)能上超過美國成為世界第一。 我國從世界各著名公司引進了多套離子膜法制堿工 藝技術(shù)和裝備后 ,淘汰了水銀法燒堿 ,石墨陽極隔膜法電解裝置也已基本淘汰 ,世界先進水平的離子膜法裝置正在增