【正文】 洛陽理工學(xué)院畢業(yè)設(shè)計(jì)（論文） I 基于 PLC 的 工業(yè)精餾控制系統(tǒng) 摘 要 精餾是石油、輕工、化工等生產(chǎn)過程中，常常需要將原料、中間產(chǎn)物或粗產(chǎn)品中的組成部分進(jìn)行分離，最常用的方法。精餾分離是根據(jù)溶液中各組分揮發(fā)度或沸點(diǎn)的差異，使各組分得以分離。精餾是化工過程中的核心組成部分，而對于精餾過程控制來說溫度的控制是重中之重，劇烈的溫度變化會導(dǎo)致分離組分離提純度降低，對精餾的效率影響極大，甚至導(dǎo)致精餾塔無法正常運(yùn)行以及設(shè)備的損壞。 本設(shè)計(jì)硬件方面采用了西門子 S7200系列 CPU型號為 226的 PLC、 K型熱電偶和溫度模 EM231。熱電偶作為溫度的采 集元件，采集的信號經(jīng)過 EM231的處理后就可把數(shù)據(jù)送入 PLC中進(jìn)行處理。 PLC的程序中 采用 了位置式 PID算法 ，實(shí)現(xiàn)溫度的自動(dòng)控制。 使 PID控制更為靈活 , 較好地滿足了生產(chǎn)過程的要求。用 WINCC上位機(jī)和西門子 S7200 PLC下位機(jī)組成一個(gè)穩(wěn)定的溫度控制系統(tǒng)， 以 達(dá)到溫度控制的目的， 初始時(shí)給系統(tǒng)一個(gè)設(shè)定值， 一旦溫度 偏離 設(shè)定值， 熱電偶采集到后把溫度變化轉(zhuǎn)變?yōu)殡娦盘杺鬟f到 PLC中 ， PLC會 發(fā)出信號 使 精餾塔 內(nèi)電阻加熱絲 ，使其增加或減小 功率 ，使溫度達(dá)到設(shè)定值。實(shí)際運(yùn)行結(jié)果驗(yàn)證了 PLC應(yīng)用于精餾塔溫度控制系統(tǒng)的可行性 及精確性。 關(guān)鍵詞： 可編程控制器，溫度控制， WINCC 上位機(jī) ， PID 控制 洛陽理工學(xué)院畢業(yè)設(shè)計(jì)（論文） II 洛陽理工學(xué)院畢業(yè)設(shè)計(jì)（論文） III Industrial distillation tower based on PLC control system ABSTRACT Distillation is the petroleum, light industry, chemical industry production process, often need to be raw materials, intermediate products or the crude product ponents were separated, the most monly used method. Distillation separation is based on the solution of volatile ponents in degree or boiling point difference, make each allocated to separate. Distillation is the process of the core ponents, and for the distillation process control, temperature control is the most important, sharp temperature change causes the separated group separation purity decreasing, the rectification efficiency greatly, and even lead to the normal operation of distillation tower and equipment damage. While the PLC has high reliability, easy programming, easy maintenance and other advantages, can be widely used in various control systems, so for the distillation process control special decided to use PLC to achieve temperature control for distillation system utility. In the rectifying tower temperature system is plicated in structure and accuracy requirements higher characteristic, adopts Siemens S7200programmable controller PLC on system temperature system. As a result of distillation column temperature lag time constant and the inertia time constant was bigger, used to separate the single loop feedback control system, easy to cause larger oscillation, so the actual is used in cascade control and cascade control main controller adopts the integral separation PID control scheme. At the same time, the single parameter fuzzy PID control and programmable controller logic instructions to bine, the PID control more flexible, to better meet the requirements of the production process. Using WINCC PC and Siemens S7200PLC machine consists of a stable temperature control system, has reached the purpose of temperature control, once the temperature does not reach the set value, monitoring software to monitor out, send a signal to transfer to the PLC for the control of a distillation column motor speed, which increases or decreases the speed, the temperature reaches set value. The actual operation 洛陽理工學(xué)院畢業(yè)設(shè)計(jì)（論文） IV results showed that PLC is applied to the distillation column temperature control system feasibility and accuracy. KEY WORDS: programmable logic controller， temperature control， WINCC PC， PID control 洛陽理工學(xué)院畢業(yè)設(shè)計(jì)（論文） V 目 錄 前 言 ................................................................................................ 1 第 1 章 緒 論 .................................................................................... 2 精餾塔的發(fā)展過程 ................................................................ 2 精餾塔簡介 .................................................................. 2 精餾塔的發(fā)展過程 ...................................................... 2 自動(dòng)化技術(shù)在精餾塔控制系統(tǒng)中的應(yīng)用。 ......................... 5 自動(dòng)化技術(shù)概況 .......................................................... 5 精餾過程的控制目標(biāo) .................................................. 5 精餾過程的基本自動(dòng)控制 ........................................... 7 論文選題的目的和意義 ........................................................ 8 論文的主要工作和技術(shù)線路 ................................................. 9 論文主要工作 .............................................................. 9 論文技術(shù)路線 ............................................................ 10 第 2 章 精餾溫控系統(tǒng)工藝流程 ..................................................... 11 精餾溫控系統(tǒng)原理 .............................................................. 11 溫控系統(tǒng)的工藝流程 .......................................................... 14 第 3 章 精餾系統(tǒng)的硬件設(shè)計(jì) ......................................................... 16 硬件配置 .............................................................................. 16 PLC 的選擇 ................................................................ 16 熱電偶 ....................................................................... 20 EM 231 模擬量輸入模塊 ........................................... 20 I/O 分配表和硬件連接圖 .................................................... 21 第 4 章 溫控系統(tǒng)軟件設(shè)計(jì) ............................................................. 23 編程軟件的功能 及選用 ...................................................... 23 PID 控制算法描述 ............................................................... 26 程序流程圖及程序 .............................................................. 29 程序流程圖 ................................................................ 29 程序 ............................................................................ 31 洛陽理工學(xué)院畢業(yè)設(shè)計(jì)（論文） VI 第 5 章 上位機(jī)監(jiān)控系統(tǒng)設(shè)計(jì) ......................................................... 35 上位機(jī)監(jiān)控軟件設(shè)計(jì) ......................................................... 35 結(jié) 論 .............................................................................................. 38 謝 辭 ................................................................................................ 39 參考文獻(xiàn) .......................................................................................... 40 附 錄 ...................................................