摘要:连续搅拌釜式化学反应器是生产过程中十分关键的设备,是一个复杂的控制对象,主要特点是大时滞、扰动变化激烈。反应器的控制质量,如对温度、压力、浓度等特征参量的控制好坏,都直接影响生产物的质量,高品质的控制系统设计较难。反应釜控制系统的任务是保证系统稳定,选择合适的控制变量,准确控制反应釜内的组份、温度等参数以达到控制目的。47469
结合控制要求,通过分析工艺流程,本论文设计了进料流量比、液位、温度、压力与组份的控制。控制算法集成了PID串级控制、双闭环比值控制及选择控制等。PLC选用西门子的S7-400 ,并用相应的SIMATIC PCS7软件编程。在化学反应器控制系统中,通过CFC实现了正常工况下的连续控制方案。
毕业论文关键词: CSTR系统;西门子S7-400PLC;SIMATIC PCS7;温度控制;串级控制
The design of the continuous chemical reactor control system circuit based on CFC
Abstract:Continuous stirred tank reactor is the key equipment in chemical production, it is a complicated control object with a large time delay, nonlinearity,time-varying characteristics and drastic changes and large amplitude disturbance.The control quality directly affects the efficiency and quality of the production. The characteristic parameters of continuous stirred tank reactor are generally temperature, pressure and concentration. The control of these parameters directly affects the quality of the product, and it is difficult to design the high quality control system.The task of the control system of the reactor is to ensure the stability of the system, select the appropriate control variables, and accurately control the parameters of the components and the temperature in the reactor to achieve the control purpose.
According to the control requirements and the analysis of the process, this paper designed the feed flow ratio, liquid level, temperature, pressure and component control. The control algorithm integrates PID cascade control, double closed-loop control and selection control etc.The hardware selection is SIEMENS S7-400 PLC, programmed by SIMATIC PCS7 . In the chemical reactor control system, CFC realizes continuous control under normal conditions.
Keywords: CSTR;SIEMENS S7-400PLC;SIMATIC PCS7; Temperature control;Cascade control
目录
1绪论 1
1.1 课题研究背景及意义 1
1.2国内外研究情况及发展 1
1.3本设计的主要工作 1
2系统分析 3
2.1工艺流程概述及分析 3
2.2 CFC图简介 5
2.3控制需求分析 6
2.3.1 进料流量及比例控制 6
2.3.2 反应器液位控制 6
2.3.3 反应器压力安全控制 6
2.3.4反应器组份控制 6
2.3.5 反应器温度控制 6
2.3.6 产物流量控制 7
2.3.7 节能环保指标控制 7
2.4对象特性分析 7
2.4.1 连续式反应器功能原理 7
2.4.2 化学反应器控制要求 7
2.4.3 反应器的特性 7
2.4.4反应器的热稳定性分析