火电厂凝汽器诊断系统的研究.doc

摘  要

凝汽系统是电站凝汽式汽轮机组重要的辅助设备，它起着冷源的作用。凝汽器运行的热力性能对汽轮机机组运行的安全性与经济性有很多影响。深入研究凝汽系统的工作机理和运行特性，建立凝汽系统运行监测模型，对提高机组经济运行水平有着重要的意义。
由于引起凝汽器故障的原因很多，判断起来不容易。本文采用比较先进的专家系统来进行凝汽器的故障诊断。论述了火电厂凝汽设备的运行特性；分析了凝汽系统的常见故障，重点分析了凝汽器故障与专家系统故障征兆之间的关系；在综合了专家系统之后，构成了凝汽器性能诊断专家系统模型。
该凝汽器性能诊断专家系统，能及时、在线地对故障有关的数据进行监测，得到故障原因和操作指导，从而使系统尽快恢复正常，保证生产的顺利进行。主要工作包括三个方面：整理了凝汽器故障知识库；开发了诊断专家系统的知识库；利用Visual Basic 6.0开发了凝汽器性能诊断专家系统。该系统具有界面友好，操作简单等特点。

关键字：凝汽器  性能诊断  专家系统 

ABSTRACT

Condenser system is condensing steam turbine power plant auxiliary equipment important, it plays the role of the cold source. Thermal performance of condenser operation has important impact to security and economy of the turbine unit operation. Depth study of the working mechanism of steam systems and operational characteristics, the establishment of steam system operation monitoring model, the level of economic operation to improve the unit has an important significance
It isn’t easy to determine Condenser Fault. In this paper, more advanced expert system for fault diagnosis of the condenser. Condensing power plants are discussed operational characteristics of equipment; of the common faults steam system, analyzes the failure of condenser fault with the expert system the relationship between symptoms; in the integrated expert system, constitutes a condenser Performance diagnostic expert system model.
The condenser performance diagnostic expert system, in time, on-line fault-related data to monitor, is cause of the malfunction and operational guidance, so that the system returns to normal as soon as possible to ensure smooth production. Main work includes three aspects: a consolidation of the condenser fault knowledge base; two developed a diagnostic expert system knowledge base; three developed using Visual Basic 6.0 condenser performance diagnostic expert system. The system is user friendly, simple operation.Visual Basic 6.0.The software is easy for operators to operate and has a friendly interface.

Key Words: condenser    performance diagnosis    expert system
 
目  录

                                       
第一章 绪论 1
1.1 课题的背景及意义 1
1.2 国内外研究现状 4
1.3 本论文的主要工作 5
第二章 火电厂凝汽器主要的性能指标和常见故障 6
2.1 概述 6
2.2 凝汽器简介 6
2.3 凝汽器主要性能指标分析及状态检测参数的确定 7
2.3.1 凝汽器主要性能指标的分析 7
2.3.2 凝汽器状态监测参数的确定 9
2.4 凝汽器故障 10
2.4.1 真空系统比严密 11
2.4.2 凝汽器冷却管 11
2.4.3 真空系统管路爆裂 11
2.4.4 凝汽器冷却管脏污 12
2.4.5 真空泵故障 12
2.4.6 循环水排水管道排水不畅 12
2.4.7 循环水量不足 12
2.4.8 凝汽器满水 13
2.4.9 凝结水泵工作不正常 13
第三章 凝汽器性能诊断系统研究 14
3.1 故障诊断的主要理论和方法 14
3.1.1 故障诊断神经网络理论和方法 14
3.1.2 故障诊断模糊诊断理论和方法 14
3.1.3 故障诊断专家系统诊断理论和方法 15
3.2 专家系统 16
3.2.2 专家系统的特征 16
3.2.3 专家系统的构成 17
3.3 凝汽器性能诊断专家系统的组成 17
3.4 知识库的不确定性表示 19
3.5 规则库的不确定性 20
3.6 结论的可信度 23
第四章 凝汽器性能监测与故障诊断系统的实现 24
4.1 凝汽器性能监测与故障诊断系统的概述 24
4.1.1 系统的编程环境 24
4.1.2 系统的运行环境 24
4.1.3 系统总体构成和功能 24
4.2 系统功能实现过程简述和主要界面 26
4.3 离线火电厂凝汽器性能诊断 29
4.4 知识库查询与编辑 30
第五章 结论与展望 32
5.1 结论 32
5.2 展望 32
参考文献 33
附录1：部分程序 34
致   谢 38