【正文】 能連續(xù)生產(chǎn)、生產(chǎn)能力大、產(chǎn)品質(zhì)量高、能適應(yīng)電流波動、能耗低、污染小等優(yōu)點，是氯堿工業(yè)發(fā)展的方向。下圖是一臺離子交換膜電解槽（包括 16 個單元槽） 。右圖表示的是一個單元槽的示意圖。在 工業(yè)生產(chǎn) 中，要避免這幾種產(chǎn)物混合，常使反應(yīng)在特殊的電解槽中進(jìn)行。 （ 1） 電解飽和食鹽水反應(yīng)原理 陽極反應(yīng)： 2Cl2e=Cl2↑（氧化反應(yīng)） H+比 Na+容易得到電子，因而 H+不斷地從陰極獲得電子被還原為氫原子，并結(jié)合成氫分子從陰極放出。使離心機(jī)控制線路大大簡化，可靠性提高。除對設(shè)備壽命有很大影響外，蒸發(fā)堿液濃度變化、操作工的操作水平及責(zé)任心不同，造成離心機(jī)分 離的鹽含堿量偏高，失堿率上升，同時增加了回收鹽水中有用鹽酸消耗，浪費(fèi)極大。目前 ,我國離子膜法裝置生產(chǎn)能力已達(dá) 656 萬 t/年 ,離子膜法生產(chǎn)工藝幾乎占到國內(nèi)燒堿裝置總產(chǎn)能的半壁江山。 關(guān)鍵詞： 燒堿生產(chǎn)； PLC；離心機(jī)；程序設(shè)計 北華大學(xué)畢業(yè)設(shè)計（論文 ） 2 Abstract On the analysis and study of caustic soda production system of centrifuge control system based on, according to some of the factory and onsite special production requirements, in the understanding of the caustic soda production process, design of centrifugal machine PLC control system. Centrifuge each electromagic valve operations are controlled by a PLC, can accord to process requirements can be achieved in the valve action. Using PLC control centrifuge each electromagic valve, further reduces the labor intensity of operators, improves the production 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(xué)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(jī)簡介 ....................................................................................................... 8 離心機(jī)的定義 ......................................................................................... 8 離心機(jī)的工作原理 .................................................................................. 8 離心機(jī)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(jī)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(xué)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(jī)和油泵的控制 ................................................................................ 29 電磁閥的控制 ....................................................................................... 29 （ 1）手動控制 ............................................................................................... 29 （ 2）自動控