自校正模糊史密斯控制器在AICS污水处理

文档编号:ZD1171   文档字数:26563,页数:63

摘  要
 随着我国经济的发展和工业化、城镇化进程的加快，水污染加剧已见端倪，成为我国社会可持续发展的瓶颈，因此改善水环境被污染的状况，加大水污染治理力度，任重而道远。AICS(交替式内循环活性污泥)工艺是一种比较先进的污水处理工艺，但AICS工艺运行模式较为复杂，对自动控制系统的要求较高，因此对AICS污水处理工艺的控制问题的研究具有非常重要的意义。
 曝气池中的溶解氧(DO)浓度作为衡量水质的综合指标，不仅能够准确反映水体受有机物污染的程度，而且直接反映鼓风机鼓入空气量的大小。由于曝气过程呈现严重非线性、时变、滞后等特点，对其进行有效的控制具有一定难度。
 本文以日照市第一污水处理厂的控制系统作为研究背景，在对污水处理曝气过程的DO浓度控制进行理论分析的基础上，建立曝气过程模型，并将模糊自适应PID控制与史密斯预估控制结合起来，设计了一种自校正模糊史密斯控制器，从而更好地适应被控对象的特点，使曝气过程达到最优状态。DO自校正模糊史密斯控制器以西门子S7-300 PLC为核心，整个控制系统主要包含PLC、变频器、鼓风机、DO检测仪。系统实现了对现场DO的数据采集、自校正模糊史密斯控制算法以及上位机监控等功能。
 仿真结果和实际应用表明，采用自校正模糊史密斯控制器后，控制系统的超调量减小，具有较强的稳定性和抗干扰性，是一种较为理想的智能控制性控制方案。利用自校正模糊史密斯控制算法对变频器进行控制后，污水处理曝气过程运行效果良好，具有显著的节能效果，减少鼓风机的磨损，延长使用寿命，显著提高了企业的经济效益与社会效益。
 
 关键词：交替式内循环活性污泥(AICS)，溶解氧(DO)，自校正模糊史密斯，西门子PLC，WinCC
 

Abstract
 With the development of economy and the rapid trend of industrialization and urbanization, the situation of water pollution is more and more serious and becomes the bottleneck of sustainable development. Therefore, it is necessary to deal with water pollution and improve water environment. Although AICS(Alternated Internal Cyclic System) is a kind of advanced technology for sewage treatment, the operation mode of AICS is complex and requires high level automatic control system. Therefore, it is significant to research the controlling technology of AICS.
 The DO (dissolved oxygen) concentration in aeration tank is an standard to judge the quality of water. The DO does not only stand for the degree of water pollution, but also reflect the amount of air from blower. Due to nonlinearity, time-varying and delay of the process of aeration, it is not easy to control DO in the aeration tank.
 Based on the No. 1 sewage treatment plant of Rizhao City, this essay analyses the controlling process of the DO in aeration tank theoretically and builts a model of areation process. In addition, a kind of self-tuning fuzzy Smith controller is designed through integrating self-tuning fuzzy PID control and the Smith predictive control to adapt controlled object and improve the aeration process. Siemens S7-300 PLC is the core of the self-tuning fuzzy Smith controller, which mainly includes PLC, frequency transformer, air blower and DO detector. The system can realize several functions, such as data capture for DO, self-tuning fuzzy Smith controlling algorithm and controlling upper machine.
 The results of simulation and practical application shows that the self-tuning fuzzy Smith controller reduces the overshoot of system, and improves the stability and anti-interference of system. It could be seen as an ideal intelligent controlling scheme. After using the self-tuning fuzzy Smith controller, the areation process works well, reduces energy consumption and friction of air blower and extendes lifetime. Finally, it improves economic benefit and social benefit of the enterprise.

 Key Words: Alternated Internal Cyclic System(AICS), DO, Self-correcting fuzzy Smith, Siemens PLC,  WinCC

目  录
第一章 绪  论 1
 1.1 课题背景及研究意义 1
 1.2 国内外污水处理工艺及自动控制系统研究现状 2
 1.3 本文所作的主要工作 3
 1.4 本文的组织结构 4
第二章 污水处理工艺及SIMATIC简介 5
 2.1 污水处理基本知识 5
2.1.1 污水处理方法 5
2.1.2 污水的常规处理工艺 5
2.1.3 主要水质指标 6
2.1.4 AICS工艺 7
2.1.5 日照市第一污水处理厂工艺 9
2.1.6 溶解氧(DO)在AICS工艺中的作用 10
 2.2 可编程控制器 10
2.2.1 PLC的特点与应用领域 10
2.2.2 SIMATIC S7-300 PLC简介 12
 2.3 上位机组态软件 13
2.3.1 组态软件的选择 13
2.3.2 WinCC简介 14
第三章 自校正模糊史密斯控制器设计 16
 3.1 AICS池系统控制分析 16
 3.2 被控对象模型分析 16
3.2.1 生化过程模型分析 17
3.2.2 曝气仿真模型分析 19
 3.3 控制策略选择 20
 3.4 MATLAB仿真分析及控制策略比较 24

第四章 基于自校正模糊史密斯控制器的AICS污水处理系统设计与实现 30
 4.1 系统结构 30
 4.2 系统相关硬件及仪表 30
4.2.1 鼓风机 30
4.2.2 溶解氧测定仪 31
4.2.3电磁流量计 32
4.2.4 pH计 33
4.2.5 变频器 34
 4.3 系统硬件组态 34
4.3.1 STEP 7编程软件介绍 34
4.3.2 SIMATIC S7-300从站的硬件组态 35
4.3.3 SIMATIC S7-300主站的硬件组态 36
 4.4 溶解氧控制算法的实现 37
4.4.1 S7-SCL编程语言介绍 37
4.4.2 控制算法 38
 4.5 WinCC上位机的组态 45
4.5.1 监控系统的结构 45
4.5.2 监控系统的设计实现 46
 4.6 结论 48
第五章 总结与展望 49
 5.1 工作总结 49
 5.2 展望 49
参考文献 51
致  谢 54
附录 55

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