基于称重法的烟尘浓度在线监测系统的工程设计及实现

发布时间：2018-04-28 09:37

本文选题：称重法 + 烟尘浓度　；参考：《太原理工大学》2017年硕士论文

【摘要】：现有烟尘浓度监测方法主要包括离线监测与在线监测两种方法。离线监测方法采用手动称重法;而以光学法为代表的在线监测方法,属于非直接称重法,不具备烟尘量值溯源的特点,影响环保部门进行有效监测执法。为此,实验室受山西省环境科学院委托,设计一套基于称重法的烟尘浓度在线监测系统,实现对火电厂超低烟尘浓度排放的在线与准确监测。根据环境监测的在线执法要求,结合我国固体颗粒物浓度测量标准中提出的称重法要求,论文从以下四个方面进行研发:(1)烟尘浓度在线监测系统的整体方案设计。按照自控工程设计方法,完成系统工艺流程设计、机械结构设计、仪表选型、电气连接等工作,并确立了系统的总体控制方案。(2)在线烟尘称重装置的开发和设计。根据系统需求分析,完成在线烟尘称重装置机电一体化结构的开发,完成以STM32为数字处理核心的嵌入式电路设计。实现了烟尘监测中滤膜的存取、传输、采样、丢弃、称重等一系列功能的自动化操作,显著提高烟尘浓度监测的准确性与工作效率。(3)烟尘浓度监测中相关信号处理与控制算法的分析。介绍本系统烟尘浓度的计算方法,分析烟尘浓度监测中烟尘质量、采样体积、烟气含氧量等参数的信号处理方法。并设计了烟尘等速采样的模糊算法,有效消除因采样流速产生的测量误差。(4)烟尘浓度在线监测系统的软件设计。通过下位机PLC和STM32的配合,完成系统的自动化控制与数据的实时采集,并完成WinCC上位机的开发,实现系统运行状态及关键参数的实时反馈,系统关键参数的历史曲线呈现,系统运行错误报警及系统的手动单步控制等功能。烟尘浓度在线监测系统被安装在山西瑞光热电厂进行现场测试,经过反复调整设计方案,系统基本满足烟尘监测要求。在环境监测领域中,解决了自动称重法测烟尘浓度的需求,为环保部门有效监测各燃煤电厂的烟尘浓度、实现烟尘量值溯源提供了依据,具有一定的实际价值。
[Abstract]:The existing monitoring methods of smoke concentration mainly include two methods: offline monitoring and online monitoring. The off-line monitoring method adopts manual weighing method while the on-line monitoring method represented by optical method belongs to indirect weighing method and does not have the characteristics of traceability of smoke and dust value which affects the environmental protection departments to carry out effective monitoring and law enforcement. For this reason, the laboratory is commissioned by Shanxi Academy of Environmental Sciences to design an on-line monitoring system of smoke and dust concentration based on weighing method to realize on-line and accurate monitoring of ultra-low smoke concentration in thermal power plants. According to the online law enforcement requirements of environmental monitoring and the requirements of weighing method put forward in the standard of measuring the concentration of solid particles in China, the overall scheme design of the on-line monitoring system of dust concentration in the following four aspects is carried out in this paper. According to the design method of automatic control engineering, the system technological process design, mechanical structure design, instrument selection, electrical connection and so on are completed, and the overall control scheme of the system, I. e., the development and design of the on-line soot weighing device is established. According to the requirement analysis of the system, the development of the mechatronics structure of the on-line soot weighing device is completed, and the embedded circuit design with STM32 as the core of digital processing is completed. The automatic operation of filter membrane access, transmission, sampling, dropping, weighing and other functions in smoke monitoring is realized. The accuracy and working efficiency of smoke concentration monitoring are improved significantly. This paper introduces the calculation method of smoke concentration in this system, and analyzes the signal processing method of smoke dust quality, sampling volume, flue gas oxygen content and so on in the monitoring of smoke dust concentration. A fuzzy algorithm is designed to effectively eliminate the measurement error caused by sampling velocity. The software design of the on-line monitoring system of smoke concentration is presented. Through the cooperation of PLC and STM32, the automatic control of the system and the real-time collection of data are completed, and the development of the upper computer of WinCC is completed. The real-time feedback of the running state and key parameters of the system is realized, and the historical curve of the key parameters of the system is presented. System running error alarm and system manual single-step control and other functions. On-line smoke concentration monitoring system was installed in Ruiguang Thermal Power Plant of Shanxi Province for field test. After repeated adjustment of the design scheme, the system basically meets the monitoring requirements of smoke and dust. In the field of environmental monitoring, the demand of automatic weighing method for smoke concentration measurement is solved, which provides a basis for the environmental protection department to effectively monitor the smoke concentration in various coal-fired power plants and to trace the source of smoke dust value, which is of certain practical value.
【学位授予单位】：太原理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X84;TP274

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