摘 要

造纸术起源于中国，是我国古代四大发明的代表之一，是我国古老人民的智慧结晶。早在西汉时期，中国就已经有了简单的纸。到了东汉，蔡伦改进了造纸术，用树皮等原料经过挫、捣、炒、烘制成纸，成为了现代纸的渊源。在造纸术中，原料是最为重要的环节之一。造纸所需要的重要的纤维往往来自于木材等材料，木材想要成为可用的纸质纤维，在古时需要人们长时间的浸泡然后手工捶打，耗时费力。由于现代化学工业的不断发展，研究发现木材水解可以获得造纸所需的纤维。因此木材水解替代了传统技术，这使得造纸的生产效率大大的提高。

20世纪以来，随着科学技术的不断发展及生产工艺不断提出新的要求，电气控制技术得到飞速发展。但早期的继电器控制技术采用固定的硬接线方式将各种继电器、定时器、接触器等按一定的逻辑方式连接起来来完成各种控制，灵活性差，可靠性低。在看到继电器控制系统的种种缺点之后可编程控制器控制系统（PLC）应运而生，并逐渐开始普及。可编程控制器是专门为在工业环境下应用而设计的数字运算操作的电子装置，它通过编程的方式，利用程序来控制各种机械装置或生产过程。PLC可以完成逻辑运算、顺序控制、定时和计算，并且具有数字量和模拟量的输入输出端口。PLC与继电器控制系统比较，其可靠性高，操作方便，编程简单，灵活多变，是继电器控制系统和通用计算机所无法比拟的。

水解反应器是水解反应的容器，在水解反应器中主要涉及到两个过程：一是在温度180℃和压力1MPa，并且在酸性环境下的预处理反应；二是在温度220℃和压力2MPa下木材水解为可用纤维的水解反应。预处理和水解都是在较为严苛的环境下进行的，人为控制基本上不可能实现。使用PLC控制系统可以控制水解反应器内部反应条件，并且采集内部的压力、温度、PH、流量等模拟量，并通过采集到的模拟量对反应过程进行控制。本文主要介绍利用可编程控制器PLC控制木材水解反应器的内部反应过程。

关键词：木材水解；可编程控制器；现代电气控制。

The Design of Hydrolysis Reactor Control System

ABSTRACT

Paper-making is originated in old China,it is one of our four great inventions of ancient China.It’s our ancestors ’wisdom crystallization. There was some simple paper in western Han dynasty. Then ,in eastern Han dynasty,Cal Lun improved the technology of paper-making. This ancient paper, which is made by bark and nets through complex processes, become the origin of modern paper. One of the important parts of paper-making is the raw material. The raw material of paper-making is the unique fiber mostly from wood and many other material. In ancient times, people had to use a lot of time to get the fiber that can be used in paper-making. With the development of modern chemical industry, we can find that wood hydrolysis can make it easier to get the fiber we need. Because of that, wood hydrolysis take the place of traditional technology of getting fiber, which greatly improve the efficiency of paper-making. Since the 20^th century ,to adapt to the needs of new production process, electric control technology has developed a lot. However, relay control technology have many disadvantages such as poor flexibility and low reliability. Due to these reasons ,people invented PLC(Programmable Logic Controller),which is designed for industrial environment and used in many other occasions. PLC uses program to control many electrical equipments. Compared with relay control technology, PLC has high flexibility and reliability. Hydrolysis reactor is designed for wood hydrolysis. It has two processes: firstly, under the 180℃ and 1MPa,wood is being pre-treated; secondly, under the 220℃ and 2MPa,the wood hydrolysis is being acted. Wood hydrolysis needs a complicated environment to make it accurate. It can not be controlled by humans, so PLC is important for the whole control process. This article mainly talk about the application of PLC in wood hydrolysis.

Keywords: Wood Hydrolysis; Programmable Logic Controller; Electric Control Technology.

目 录

1 绪论………………………………………………………………………………………………………1

• 1. 水解反应器在工业中应用的意义…………………………………………………………………1
  2. 水解反应器在国内外的发展………………………………………………………………………1
  3. 工业控制的应用……………………………………………………………………………………2
  4. 可编程控制器简介…………………………………………………………………………………2
  5. 可编程控制器的发展………………………………………………………………………………3
  6. PLC的应用领域……………………………………………………………………………………3
  7. PLC在我国的发展和应用…………………………………………………………………………3

2 水解反应器系统原理……………………………………………………………………………………5

2.1 水解反应器系统简介………………………………………………………………………………5

2.2 水解反应器系统主要装置设计……………………………………………………………………5

2.3 水解反应器系统反应流程…………………………………………………………………………9

2.4 水解反应器的控制系统的选择…………………………………………………………………10

3 基于PLC的水解反应器控制系统硬件设计…………………………………………………………11

3.1 控制系统的硬件系统……………………………………………………………………………11

3.1.1 硬件系统的基本构成………………………………………………………………………11

3.1.2 控制系统硬件选型…………………………………………………………………………12

3.2 控制系统的传感器………………………………………………………………………………14

3.2.1 PH值传感器…………………………………………………………………………………15

3.2.2 温度传感器…………………………………………………………………………………15

3.2.3 压力传感器…………………………………………………………………………………15

3.2.4 电磁流量计…………………………………………………………………………………16

3.3 水解反应器PLC控制系统外接线路图…………………………………………………………16

3.1.1 主电路图……………………………………………………………………………………16

3.1.2 控制系统电路图……………………………………………………………………………17

4 基于PLC的水解反应器控制系统的软件设计………………………………………………………19

4.1 PLC编程语言概述…………………………………………………………………………………19

4.1.1 指令表………………………………………………………………………………………19

4.1.2 结构化文本…………………………………………………………………………………19

4.1.3 梯形图………………………………………………………………………………………19

4.1.4 功能块图……………………………………………………………………………………19

4.1.5 顺序功能图…………………………………………………………………………………20