多效蒸餾水機(jī)控制系統(tǒng)的研究與實(shí)現(xiàn)

論文編號(hào):ZD1225   論文字?jǐn)?shù):30830,頁(yè)數(shù):64  附原理圖，外文翻譯

 摘       要
 
 蒸餾水機(jī)的運(yùn)行過程十分復(fù)雜，其熱交換回路中主蒸汽壓力、溫度與原料水的壓力、溫度、流量耦和緊密，且呈現(xiàn)非線性關(guān)系，依據(jù)傳統(tǒng)的方法很難建立一個(gè)精確的數(shù)學(xué)模型。本文以化工熱交換原理為基礎(chǔ)，從雙效蒸發(fā)器入手，建立其數(shù)學(xué)模型。
 在蒸餾水生產(chǎn)過程中需要控制兩個(gè)重要參數(shù)：一是蒸餾水在出口處的電導(dǎo)率，另一是蒸餾水在出口處的溫度。電導(dǎo)率一般通過調(diào)節(jié)原料水的閥門開度來控制；出口溫度一般通過調(diào)節(jié)進(jìn)入熱交換器的蒸汽流量來控制。這是一個(gè)典型的雙入雙出的控制系統(tǒng)。由于蒸餾水機(jī)系統(tǒng)本身具有大滯后、非線性、時(shí)變、強(qiáng)干擾等特性，造成雙入雙出的控制系統(tǒng)是一個(gè)強(qiáng)耦合的控制系統(tǒng)。在本設(shè)計(jì)中，我們采用了簡(jiǎn)化解耦的設(shè)計(jì)方法，對(duì)雙入雙出的控制系統(tǒng)進(jìn)行解耦。由于純汽輸出回路和冷卻水回路都是熱交換回路的強(qiáng)烈干擾源，這樣常規(guī)的PID控制就不能很好的保證經(jīng)過解耦后的雙入雙出控制系統(tǒng)的精度。鑒于此，本文采用由PID控制器和專家控制器一起組成自整定PID控制器進(jìn)行控制。
 結(jié)合蒸發(fā)過程實(shí)際，在研究專家系統(tǒng)的基礎(chǔ)上，本文建立了比較完善的知識(shí)庫(kù)，并且對(duì)知識(shí)庫(kù)進(jìn)行了量化處理，采用正向推理機(jī)制，啟發(fā)式搜索方式，交互式人機(jī)接口開發(fā)設(shè)計(jì)了適用于醫(yī)藥用蒸餾水生產(chǎn)過程的專家系統(tǒng)。   
 
 
 【中文關(guān)鍵詞】多效蒸餾水機(jī) 數(shù)學(xué)模型 PID控制 專家系統(tǒng)
 
  Distilled water machine's work process is very complicated. The main steam pressure, temperature of its hot exchange loop and the pressure, temperature, liquid quantity of raw material water connect closely and present nonlinear relation. In terms of traditional methods, it's very hard to establish a precise mathematics model.                       regarding hot exchange principle of chemical engineering as the foundation, we start from double-function evaporation equipment in this paper, then process it.
 During the process, we need to control two important parameters:one is the electric conductivity rate of distilled water at exit; another is the temperature of distilled water at exit. Electric conductivity rate generally is controlled by regulating the raw material water's valve door, while export temperature generally is controlled by regulating steam quantity passed into the heat exchanger. This is a typical control system with double inputs and double outputs. Because the distilled water machine has the characteristics of serious delay, nonlinear, strong interference etc., this system is a closely coupling system. In this design, we adopt simplified method to remove the coupling of this system with double inputs and double outputs. Because the pure vapor output loop and cool water loop are all hot exchange loop's strong interference resource,  common PID can't achieve satisfactory effect. For this reason, this paper adopt  PID controller composed of PID controller and expert system to control the system.
 Combined the actual evaporating process, on the basis of expert system, this paper establish the perfect knowledge warehouse and adopt forward-reasoning mechanism, inspiring research method, exchange person-machine junction to design an expert system applicable to the distilled water production.
 
 【English Linchpin Word】Multi-effect distilled water machine; Mathematic Model;  PID control; Expert system;   
 
 
目        錄

第一章    緒論 5
1.1 蒸餾水機(jī)現(xiàn)狀 5
1.2 控制技術(shù)在蒸餾水機(jī)中的應(yīng)用 5
第二章   方案論證 7
2.1工藝過程 8
第三章    PLC硬件系統(tǒng)的設(shè)計(jì) 9
3.1 PLC-FP3的選擇 9
3.2  I/O分配 9
3.2.1由安裝在底板上的位置確定地址 9
3.2.2用編程工具設(shè)定地址 10
3.3 CPU單元 12
3.3.1 FP3-CPU單元的特殊功能 14
3.3.2 FP3-CPU單元的指令系統(tǒng) 19
3.3.3  存儲(chǔ)區(qū)分配 21
3.3.4 蒸餾水機(jī)中I/O輸入、輸出回路設(shè)計(jì) 23
3.4  A/D單元 25
3.4.1、占用I/O點(diǎn)及I/O分配 25
3.4.2、共享存儲(chǔ)器 26
3.4.3、技術(shù)參數(shù) 27
3.4.4 蒸餾水機(jī)A/D輸入回路設(shè)計(jì) 28
3.5 D/A單元 29
3.5.1、占用I/O點(diǎn)及I/O分配 30
3.5.2、共享存儲(chǔ)器 30
3.5.3、技術(shù)參數(shù) 31
3.5.4 蒸餾水機(jī)D/A輸出回路設(shè)計(jì) 31
3.6  PLC外接檢測(cè)元件的選用 32
3.6.1 溫度傳感器 32
3.6.2壓力傳感器 34
3.6.3 二位三通電控?fù)Q向閥 34
3.6.4 液位傳感器的選用 35
3.6.5 電動(dòng)調(diào)節(jié)閥的選用 36
第四章  專家控制算法 38
4.1專家控制系統(tǒng)的概念和特征 38
4.2 專家控制系統(tǒng)的分類 40
4.2.1基于規(guī)則的專家整定和自適應(yīng)控制器 40
4.2.2  專家監(jiān)督控制系統(tǒng) 41
4.2.3  實(shí)時(shí)專家智能控制系統(tǒng)。 42
4.3  專家控制系統(tǒng)的基本思想和結(jié)構(gòu) 42
4.3.1  專家控制的基本思想 42
4.3.2 專家控制的知識(shí)表示 43
4.3.3 專家控制系統(tǒng)的組織結(jié)構(gòu) 45
4.4專家系統(tǒng)結(jié)構(gòu)設(shè)計(jì)與實(shí)現(xiàn) 46
4.4.1 軟件的設(shè)計(jì)與實(shí)現(xiàn) 47
4.4.2建立專家系統(tǒng)的知識(shí)庫(kù) 47
4.4.3專家系統(tǒng)推理機(jī)的設(shè)計(jì) 48
4.4.4人機(jī)接口設(shè)計(jì) 49
第五章 PID控制算法 51
5.1控制算法的確定 51
5.1.1數(shù)學(xué)模型的建立 51
5.1.2控制算法 51
5.1.3 PID參數(shù)的整定 52
5.2系統(tǒng)采樣周期的確定 54
5.2.1香農(nóng)采樣定理 54
5.3數(shù)字濾波方法的選擇 55
5.3.1數(shù)字濾波的優(yōu)點(diǎn) 55
5.3.2數(shù)字濾波的幾種方法 55
總         結(jié) 57
參 考 文 獻(xiàn) 58
附 錄 59
程 序 清 單 59