【作者】 杨柳；

【导师】 王化祥； 黄晓玲；

【作者基本信息】 天津大学 ， 检测技术与自动化装置， 2004， 硕士

【摘要】 工业锅炉炉膛中存在两种火焰，一为炉体火焰，一为若干个喷火嘴喷出的火焰，工厂常常需要知道在炉体背景火焰下，喷嘴是否在喷火，以确定各个喷嘴的运行状态。工业上把火焰检测器将炉体火焰误判为喷嘴火焰的情况称为“偷看”；把不能透过炉体火焰看到喷嘴火焰的情况称为“漏看”。检测器“偷看” 和“漏看”的频繁发生，会对锅炉的正常运行造成严重的影响。“偷看” 和“漏看”的实质是无法对重叠的火焰进行准确的判断，因此如何对重叠的火焰进行准确的判断成为解决此问题的关键。本文详细介绍了火焰检测技术的原理、发展动态，总结了光电技术在火焰检测方面的应用。通过对几种光电检测电路的比较和分析，在试验测试的基础上，构建了一个性能较好的信号提取电路。采用电压编程精确滤波器对信号进行滤波，并以TMS320LF2407A DSP为核心，设计出一个进行光电转换、信号调理、数据采集的硬件平台。软件设计方面，采用汇编语言实现了系统控制、频谱分析和与上位机的通讯，同时在上位机中用VC＋＋编程，实时显示了频谱数据的柱状图。在基于闪烁频率法检测火焰的原理上，提出了一种以快速傅立叶变换（FFT）分析火焰闪烁频谱，建立火焰重叠判据，从而判断火焰重叠与否的方法。为解决“偷看” “漏看” 提供了一种新方案。此外，本文还对系统的深入设计和优化提出了建议。更多还原

【Abstract】 There are two kind of flame in industry internally fired boiler. One is boiler-body flame the other is flame from burner nozzles. In order to judge the operation status of boiler, workers need to know whether the burner nozzle is burning or not under the background flame of boiler-body. In industry we define “peek” as phenomenon that the detector take the boiler-body flame as burner-nozzle’s flame .We define “leak” as phenomenon that the detector can not probe the burner-nozzle’s flame though boiler-body flame. These two phenomena will damage boiler if they happen too frequently. The essential of the phenomena is the detector cannot judge the overlapping status of flame. So how to judge the overlapping status of flame is the focus of the problem.This thesis introduces the foundation and development of flame detection technology and summarizes the application of photoelectric technology in flame detection. Through comparing and analyzing of photoelectric detecting circuit, an efficient signal detecting circuit is established based on the data obtained from experimentation. A precision voltage programmable filter is used to deal with the signal. Using TMS320LF2407A DSP as controller, a hardware system for photoelectric transforming, signal dealing and sampling is designed. As for software design, it realizes the function of system controlling, frequency analyzing and communication with PC using assembly language. At the same time graph of real time data is displayed on PC using VC++ as programming tool. Based on the detection method of flame flicking frequency, a new method for judge the overlap status of two flames is proposed. The method use FFT (Fast Fourier transform) to analyze frequency spectrum of flame flicking frequency and build the flame overlapping criterion then compare the field data with the criterion to know whether the two flames overlap or not. This method is a new solution for “peek” and “leak” phenomena.Furthermore advice for deep research and optimizing design is also presented.更多还原