基于PLC和OPC在氨合成塔温度控制系统设计毕业论文

基于PLC和OPC在氨合成塔温度控制系统设计毕业论文

目录

摘要 (3)

第1章引言 (5)

1.1 工业过程控制概述 (5)

1.2 氨合成塔温度控制概述 (6)

1.3 课题来源及主要任务 (8)

第2章各种控制策略的介绍 (9)

2.1 反馈控制 (9)

2.2 前馈控制 (14)

2.3 串级控制系统 (18)

第3章合成氨工艺的介绍 (20)

3.1 氨合成生产的流程 (20)

3.2 氨合成塔 (22)

3.3 氨合成工艺条件选择 (26)

3.4 催化剂的还原、钝化和再升温 (30)

3.5 催化剂的卸出 (32)

3.6 系统概述 (33)

第4章控制策略的选择 (35)

4.1 氨合成塔控制系统分析 (35)

4.1.1 控制方案的选取 (35)

4.1.2 被控对象的数学模型 (36)

第5章 PLC的设计和仿真 (38)

5.1 控制系统 (38)

5.2 设计PLC程序 (38)

5.2.1 简要介绍运行程序 (38)

5.2.2 程序的编写 (39)

第6章 WinCC的仿真 (52)

6.1 创建新项目 (52)

6.2 组态变量 (53)

6.3 创建过程画面 (55)

6.4 组态画面对象 (56)

6.5运行组态项目 (62)

第7章结论与展望 (63)

7.1 全文总结 (63)

7.2 展望 (63)

参考文献 (65)

致谢 (66)

外文文献翻译 (67)

基于PLC和OPC在氨合成塔温度控制系统设计

摘要

氨是最为重要的基础化工产品之一，其产量居各种化工产品的首位; 同时也是能源消耗的大户，世界上大约有10 %的能源用于生产合成氨。氨主要用于农业,合成氨是氮肥工业的基础，氨本身是重要的氮素肥料，其他氮素肥料也大多是先合成氨、再加工成尿素或各种铵盐肥料，这部分约占70 %的比例，称之为“化肥氨”；同时氨也是重要的无机化学和有机化学工业基础原料，用于生产铵、胺、染料、炸药、制药、合成纤维、合成树脂的原料，这部分约占30 %的比例,称之为“工业氨”。

我国合成氨装置以中小规模居多,年产30万吨以上的大型合成氨装置很少；合成氨系统自动化程度低,尤其是关键的氨合成塔温度控制绝大多数是人工操作,工人劳动强度大且温度控制效果不好.因此氨合成系统先进控制技术的研究与应用已成为合成氨工业的迫切要求,对我国合成氨生产企业在现有条件下挖潜增效,提高经济效益和竞争力具有重要意义。

本文分析了氨合成工艺和氨合成塔床层温度控制的特点, 通过对不同位置的温度响应分析比较、对控制点位置的选择提供了基础。为了满足在线控制的需

要提出简化控制模型结构，本文采用一阶加纯滞后模型结构。该模型通过实验进行验证，结果是令人满意的。

PLC具有结构简单、编程方便、性能优越、灵活通用、使用方便、可靠性高、搞干扰能力强等到一系列优点，在工业生产过程自动控制领域得到了广泛应用。本文就基于PLC完成对氨合成塔温度的控制。

关键词：氨，氨合成系统，氨合成塔， PLC

ABSTRACT

Ammonia is the most important one of basic chemical products and the production of chemical products is in the first place; At the same time it is also a large family of energy consumption and the world about 10% of the energy used in the production of synthetic ammonia.Ammonia is mainly used for agriculture and ammonia nitrogen is the foundation of industrial.Other nitrogen fertilizer are is first synthetic ammonia, then processed into urea ammonium salt or kinds of fertilizer, this part of the proportion of about 70%, which is called "chemical fertilizer ammonia".Ammonia is also important inorganic chemistry and organic

chemical industrial base material,which used in the production of ammonium, amine, dye, explosives, pharmacy, synthetic fiber, synthetic resin of raw materials, which account for about 30% of the proportion, called "industrial ammonia".

Most of synthetic ammonia plants in China are small and medium -sized. Annual output of 30 tons or more of the large- scale ammonia plant is very few. Ammonia system is very low degree of automation. Especially critical vast majority of ammonia is a manual temperature control. Especially critical vast majority of ammonia is manual temperature control. Labor intensity is great and effect of temperature control is not good. Therefore, advanced control technology Ammonia Synthesis System Research and Application Has become an urgent requirement for ammonia industry. It has great significance to Ammonia production enterprises in China under the condition of tapping the potential synergies in the existing and Enhance economic efficiency and competitiveness.

Ammonia synthesis and the three casing type ammonia synthesis tower of bed temperature control for quench ammonia synthetic tic tower are analyzed. Based on the different positions of temperature response analysis comparison, control provides the basis for the positions. In order to meet the needs of on-line control this simplified control model structure is adopted in this paper, variable parameter and first-order