【作者】 环久峰；

【导师】 王栋；

【作者基本信息】 大连理工大学 ， 环境工程， 2006， 硕士

【摘要】 本研究选取热力系统的水汽循环作为研究对象,针对目前水汽质量监测的特点和现有监控系统在故障诊断分析和预防方面的不足,阐述了研究热力系统水质化学诊断的必要性及应用前景。研究中采用水质温度响应和实际案例分析等手段,系统地分析了因水汽质量恶化引起故障的机理及特点,在此基础上引入专家系统、故障诊断技术等理论方法,研究并开发了循环热力系统水质化学诊断专家系统和水汽质量监控软件。 实验选取六种典型锅炉水处理工况下的模拟水相,跟踪电导率和pH随温度变化的情况。对实验结果的解析可得出:①不同的炉水处理工况下,水样电导率温度补偿系数差异明显,实际监测中不应采用统一的温度补偿系数。②各水样电导率温度响应关系符合Arrhenius关系,计算得出的电导活化能受温度影响比较小,可用作表征体系热力学性质的一项量化指标。 以某企业的空冷换热器的腐蚀实效为案例,采用水质分析,水样pH、电导率温度响应,配合电镜、电子能谱分析、XRD等手段,解析了腐蚀失效是氧腐蚀、二氧化碳腐蚀和应力集中的协同作用结果,同时还确认了由水质数据进行故障诊断的可行性。 研究中讨论了基于专家系统进行水汽故障诊断的技术基础。在案例分析和总结文献的基础上,初步确定了水质化学诊断的重点指标、知识的表示形式和诊断规则,开发了水质化学诊断专家系统的知识库、人机界面和核心推理程序。构建了实时水质数据的异常辨识和在线诊断的功能框架。诊断结果给出故障原因、影响及处理对策。 最后对水质监控软件的开发过程,监控软件与现场设备的通讯、应用DDE(动态数据交换)技术实现监控软件和水质化学诊断专家系统之间的双向通讯、监控界面的动态网页发布等功能的实现方法给与说明。更多还原

【Abstract】 Basing on the Water/steam system in thermal system, the significances and excellent prospect of water quality chemical diagnosis research is described according to the features of water/steam quality monitoring as well as the deficiency in fault diagnosis and preventive measures. In this research, the mechanisms and features of faults caused by impurities in Water/steam system is roundly analyzed by using both temperature response of water quality and one real case study. At the mean time a water quality chemical diagnosis expert system and a real-time monitoring software are developed applying with methods of ES （Expert System） and fault diagnosis etc.Six typical working conditions models of boiler water have been chosen to manage the changes in electrical conductivity and pH, which are traced at different temperatures. Following conclusions can be draw by analyzing the experiment results: ① Different water sample can lead to great differences in electrical conductivity temperature compensate coefficient, so the temperature compensate coefficient should be chosen according to actual condition. ② The conductivity temperature responses are coincident with Arrhenius equation. The influences from the temperature to the values of conductivity activation energy （Ea） are slim. Therefore Ea can be acomparison index of thermodynamic parameters for different systems.Taken the air cooled heat exchanger of some company as an example, the corrosion failure of an air-steam heat exchanger was analyzed by means of water quality analysis, temperature response of pH and conductivity as well as SEM, EDS and XRD. The diagnosis concludes that the cooperation of oxygen corrosion and CO₂ corrosion is the primary reason for the failure. The feasibility of using water quality as basic data for fault diagnosis is also validated.In this research, the water/steam fault diagnosis in the company of ES method is discussed. Basing on the results of case study and literatures, some modules of water quality diagnosis expert system, such as such as primarily parameter, form of knowledge and rules of diagnosis, are established;knowledge library, software interface and key rules are developed;function frames of distinguish abnormal real-time data and online diagnosis are constructed. The reasons of fault, influences and corresponding preventive measures have been provided as well.In the end some introductions are given for the developing process of monitoring software, communication between monitoring software and local instruments, communication between monitoring software and diagnosis expert system through DDE（Dynamic Data Exchange） as well as dynamic Web publishing of monitoring interface etc.更多还原