辐射光谱法电站锅炉燃烧检测诊断研究
发布时间：2018-07-26 10:19
【摘要】：燃煤火电机组是我国电力工业的支柱,占主导地位。因此,准确有效的监测现代燃煤电站锅炉炉内火焰,对电站锅炉和电厂的高效安全运行具有十分重要的意义。本文基于自行研制的以光纤光谱仪为核心的火焰检测系统对燃料燃烧火焰和电站锅炉炉内燃烧状况进行了研究,提出了对光谱火焰测温法的改进方法和一种简单方便并适合在线测量的火焰光谱发射率测量方法,自行研制了火检探针,在一台300MW煤粉锅炉上开展了试验研究,给出了利用该火检探针在电站锅炉实测的结果,并对结果进行了深入的分析。本文的主要内容及创新点如下:(1)火焰温度是炉内燃烧监测诊断的一个重要参数,基于CCD光纤光谱仪的火焰温度检测方法因其具有独特的优点而成为火焰温度测量领域的研究热点之一。由于CCD本身的光谱响应特性,光谱仪需要用黑体炉进行标定。但当标定温度和被测温度相差较大时,测得的被测物体温度与实际温度误差较大。另外,当光谱仪测得的响应强度与标定时对黑体炉的响应强度相差较大时,得到的温度值也会存在较大误差。本文就上述两种误差提出了解决方法,实验证明改进之后测量误差大大减小,使得基于光纤光谱仪的火焰辐射测温范围大幅度扩大。(2)以往在线测量非灰体火焰光谱发射率的方法,由于理论不完善,存在诸多缺陷。本文主要针对不同燃料的燃烧火焰,提出一种基于近红外光谱仪的测量火焰光谱发射率的方法,并与其他火焰光谱发射率模型进行了比较和验证。另外,作者还提出了一种基于火焰光谱发射率的混合燃料组份的检测方法。(3)火焰的闪动频率,作为火焰稳定性的一个参照,是火焰检测和燃烧诊断的一个重要判据。但是由于在工业炉膛内的火焰信号具有较宽的频谱,在信号的整个频谱范围内都包含噪声,并且噪声在高频范围内占支配地位,在对信号进行处理之前必须对信号作消噪处理,这样才能高效提取信号中的有用信息。本文中利用小波阈值法对电站锅炉中采集到的光谱信号进行消噪,然后对消噪后的信号作快速傅里叶变换得到火焰的闪动频率。(4)在利用光谱法研究温度、辐射率和火焰闪动频率的测量方法之后,研制了火检探针,本文给出了该火检探针在电站锅炉实测的结果,并对结果进行了深入的分析,为基于这三个参数提出一套锅炉燃烧诊断方案奠定了基础。这也是本课题研究的最终目的:建立火力发电站中燃煤锅炉的火焰检测和燃烧诊断体系,为电站锅炉的高效稳定安全运行和变负荷时各参数的调节提供正确高效的依据和保障。
[Abstract]:Coal-fired thermal power unit is the mainstay of our country's electric power industry, occupies the leading position. Therefore, the accurate and effective monitoring of the flame in the furnace of the modern coal-fired power plant boiler is of great significance to the efficient and safe operation of the utility boiler and the power plant. In this paper, the flame detection system based on fiber-optic spectrometer has been developed to study the combustion status of fuel combustion flame and boiler furnace. In this paper, an improved method of spectral flame temperature measurement and a simple and convenient method for measuring flame spectral emissivity are presented. The flame detection probe is developed, and the experimental study is carried out on a 300MW pulverized coal boiler. The measured results of the fire detection probe in the boiler of power station are given, and the results are analyzed in depth. The main contents and innovations of this paper are as follows: (1) Flame temperature is an important parameter for combustion monitoring and diagnosis in furnace. The flame temperature detection method based on CCD optical fiber spectrometer has become one of the research hotspots in flame temperature measurement field because of its unique advantages. Because of the spectral response of CCD, the spectrometer needs to be calibrated by blackbody furnace. However, when the difference between the calibrated temperature and the measured temperature is large, the error between the measured object temperature and the actual temperature is larger. In addition, when the response intensity measured by the spectrometer is different from the response intensity of the calibration to the blackbody furnace, there is also a large error in the obtained temperature value. In this paper, the methods of solving the above two kinds of errors are put forward. The experimental results show that the measurement error is greatly reduced after the improvement. The range of flame radiation temperature measurement based on fiber-optic spectrometer is greatly expanded. (2) the methods of on-line measurement of flame spectral emissivity of non-gray body have many defects due to the imperfect theory. In this paper, a method of measuring flame spectral emissivity based on near infrared spectrometer is proposed, and compared with other flame spectral emissivity models. In addition, the author also proposes a method for the detection of mixed fuel components based on flame spectral emissivity. (3) Flame flash frequency, as a reference for flame stability, is an important criterion for flame detection and combustion diagnosis. However, because the flame signal in the furnace has a wide spectrum, noise is included in the whole spectrum range of the signal, and the noise dominates in the high frequency range, so the signal must be de-noised before the signal is processed. In this way, useful information can be extracted efficiently. In this paper, the wavelet threshold method is used to de-noise the spectral signal collected in the boiler of power station, and then the fast Fourier transform of the de-noised signal is used to get the flash frequency of the flame. (4) the temperature is studied by using the spectral method. After measuring the emissivity and flame flashover frequency, a fire detector probe is developed. The measured results of the probe in the boiler of power station are given, and the results are analyzed deeply. It lays a foundation for a boiler combustion diagnosis scheme based on these three parameters. This is the ultimate purpose of this study: to establish the flame detection and combustion diagnosis system of coal-fired boilers in thermal power stations, to provide a correct and efficient basis and guarantee for the efficient, stable and safe operation of utility boilers and the adjustment of the parameters when the load is changed.
【学位授予单位】：上海理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM621.2
本文编号：2145683
[Abstract]:Coal-fired thermal power unit is the mainstay of our country's electric power industry, occupies the leading position. Therefore, the accurate and effective monitoring of the flame in the furnace of the modern coal-fired power plant boiler is of great significance to the efficient and safe operation of the utility boiler and the power plant. In this paper, the flame detection system based on fiber-optic spectrometer has been developed to study the combustion status of fuel combustion flame and boiler furnace. In this paper, an improved method of spectral flame temperature measurement and a simple and convenient method for measuring flame spectral emissivity are presented. The flame detection probe is developed, and the experimental study is carried out on a 300MW pulverized coal boiler. The measured results of the fire detection probe in the boiler of power station are given, and the results are analyzed in depth. The main contents and innovations of this paper are as follows: (1) Flame temperature is an important parameter for combustion monitoring and diagnosis in furnace. The flame temperature detection method based on CCD optical fiber spectrometer has become one of the research hotspots in flame temperature measurement field because of its unique advantages. Because of the spectral response of CCD, the spectrometer needs to be calibrated by blackbody furnace. However, when the difference between the calibrated temperature and the measured temperature is large, the error between the measured object temperature and the actual temperature is larger. In addition, when the response intensity measured by the spectrometer is different from the response intensity of the calibration to the blackbody furnace, there is also a large error in the obtained temperature value. In this paper, the methods of solving the above two kinds of errors are put forward. The experimental results show that the measurement error is greatly reduced after the improvement. The range of flame radiation temperature measurement based on fiber-optic spectrometer is greatly expanded. (2) the methods of on-line measurement of flame spectral emissivity of non-gray body have many defects due to the imperfect theory. In this paper, a method of measuring flame spectral emissivity based on near infrared spectrometer is proposed, and compared with other flame spectral emissivity models. In addition, the author also proposes a method for the detection of mixed fuel components based on flame spectral emissivity. (3) Flame flash frequency, as a reference for flame stability, is an important criterion for flame detection and combustion diagnosis. However, because the flame signal in the furnace has a wide spectrum, noise is included in the whole spectrum range of the signal, and the noise dominates in the high frequency range, so the signal must be de-noised before the signal is processed. In this way, useful information can be extracted efficiently. In this paper, the wavelet threshold method is used to de-noise the spectral signal collected in the boiler of power station, and then the fast Fourier transform of the de-noised signal is used to get the flash frequency of the flame. (4) the temperature is studied by using the spectral method. After measuring the emissivity and flame flashover frequency, a fire detector probe is developed. The measured results of the probe in the boiler of power station are given, and the results are analyzed deeply. It lays a foundation for a boiler combustion diagnosis scheme based on these three parameters. This is the ultimate purpose of this study: to establish the flame detection and combustion diagnosis system of coal-fired boilers in thermal power stations, to provide a correct and efficient basis and guarantee for the efficient, stable and safe operation of utility boilers and the adjustment of the parameters when the load is changed.
【学位授予单位】：上海理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM621.2
【参考文献】
相关博士学位论文 前1条
1 宋扬;光谱发射率在线测量技术研究[D];哈尔滨工业大学;2009年
，本文编号：2145683
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