DSP锅炉火焰检测系统设计

通过对锅炉火焰燃烧特性的研究,提出了基于DSP的锅炉火焰检测系统的检测原理,并详细介绍了用于煤火检测的可见光型火检探头的设计方法,以及如何利用DSP实现快速傅立叶变换（FFT）算法完成信号的频谱分析。     

全炉膛灭火保护的探讨

本文在分析现有炉膛安全监控系统在处理“全炉膛灭火”信号时存在一些问题的基础上，提出将全炉膛火检直接接入炉膛安全监控系统，将两“全炉膛灭火”信号相与相同决定是否ＭＦＴ，以提高现有系统可靠性的方案。文中对基于数字图像处理的全炉膛火检系统及其工业试验结果进行了介绍。     

600 MW燃煤机组火检光纤可靠性分析与改进

燃煤机组火焰的检测至关重要,火检信号开关量带有主保护,所以火焰检测装置的可靠性直接影响锅炉的安全稳定运行。现分析了火检光纤故障的主要原因,在此基础上对火检光纤冷却系统进行了改造,达到了保护光纤的目的。     

炉膛火焰数字图像处理系统研究和应用

本文着眼于目前在电站锅炉火检系统中应用最为广泛的炉膛火焰数字图像处理系统、分析了其硬件系统的构成，通过对其典型部件的研究，提出在炉膛火焰监测中，硬件设备的选择依据，以及硬件系统实施的注意，对于炉膛火焰的数字图像处理的精确性、稳定性、可靠性有着重要的意义。     

重载铁路电化区段信号机械设备故障自动检测方法

为解决重载铁路电化区段信号机械设备故障在检测中存在检测结果误差大、错检与漏检率高等问题，设计了重载铁路电化区段信号机械设备故障自动检测方法。分析重载铁路电化区段信号机械设备的组成，以及机械设备运行的自动化控制过程，确定机械设备故障类型；针对不同故障类型设置故障自动检测判据，利用传感器设备采集实时运行数据，通过滤波和融合后输出初始数据样本，提取信号机械设备实时信号特征，通过计算检测判据相似度，确定信号机械设备故障类型，输出故障自动检测结果。实验结果表明，所提方法综合信号机械设备故障位置、程度等多个方面，使平均检测误差低于1.0,错检率和漏检率均低于1%,提升了重载铁路电化区段信号机械设备故障自动检测的有效性。     

火检信号异常导致锅炉MFT事件分析与改进

对于锅炉安全系统而言,火焰检测器是至关重要的部件,其主要功能是准确地鉴别出燃料送入炉膛而未被点燃时可能导致炉膛爆炸的潜在危险,正是由于它的重要性,决定了其性能必须安全可靠。然而燃烧器喷嘴附近恶劣的工作环境、机组运行时背景工况的不确定性,以及相关逻辑的不合理都易造成火检信号的异常。现就某600MW燃煤发电机组试运过程中火检信号异常导致锅炉MFT的事件进行分析,并提出了预防与改进措施。     

炉膛燃烧图像预处理技术及应用

介绍了数字图像锅炉炉膛火焰检测系统的组成，研究了数字图像预处理的算法，包括平滑、锐化和边缘检测等技术及其在锅炉燃烧火焰监测系统中的应用。     

基于图像处理的嵌入式火焰检测系统

针对目前锅炉火焰监视和燃烧状态检测系统存在的火焰图像处理能力不足、实时性差等问题,提出了基于图像处理的嵌入式火焰检测系统,介绍了系统的硬件构成、各功能模块电路和软件设计。现场运行结果表明,该系统能够快速准确地检测出不同工况下火焰的燃烧状态,提供可靠的燃烧预警和灭火保护信号输出,保障了锅炉安全运行。     

1000MW机组火检失去原因分析与解决方案

某百万机组电厂降负荷时,频繁发生火检系统熄火导致磨煤机跳闸现象。针对这一现象,本文从锅炉燃烧特性和火焰检测特性出发,结合电厂实际运行情况,对该类故障现象展开了详细分析探讨,确认了故障产生的主要原因。通过对火检系统的套管改造,结合燃烧系统调整和控制逻辑优化,从根本上排除了安全隐患。     

提高锅炉火检系统可靠性的措施研究

从系统电源、光纤冷却效果和探头老化等方面分析了火检系统可靠性降低的原因,并制定了合理的改进措施,从而提高了火检系统的稳定性和可靠性,为锅炉安全运行提供了保障。     

新型智能一体化火焰检测器在FSSS系统中的应用

本文通过分析锅炉炉膛煤粉燃烧火焰的状况,说明了火焰检测系统在锅炉炉膛安全系统中的重要作用。介绍一种新型智能一体化火焰检测器,并对该产品的工作原理、技术性能指标、应用等进行了论述。     

光伏用电致发光缺陷检测仪空间分辨率的量化评估

针对光伏用电致发光缺陷检测仪空间分辨率目视判定重复性、准确性差,并且难以量化等问题,提出一套基于卷积神经网络模型的空间分辨率量化评估方法。参照相关标准JJF(闽)1088-2018,采取不同的拍摄条件拍摄并切割出空间分辨率线对图像,对图像进行人工分类。设计卷积神经网络结构,采用卷积层、池化层和全连接层结构,并使用已分类完成的空间分辨率线对图像对模型进行训练。最终使用测试集对模型进行评估,结果表明,模型在测试集上的判别正确率达到99.2%。该方法满足使用要求,可取代目视判别,提高了光伏用电致发光缺陷检测仪空间分辨率判定的准确性与重复性,并为其量化提出了新的解决思路。由于太阳电池片用光致发光缺陷检测仪与光伏用电致发光缺陷检测仪的成像方式类似,该方法可兼容太阳电池片光致发光检测仪的性能评估。     

液化石油气中硫化物的测定方法

对液化石油气中硫化物的分析方法进行了评述。总硫测定多采用氧化微库仑法,灯法等。形态硫分析多采用气相色谱与硫选择性检测器结合的方法,这些检测器有火焰光度检测器（FPD）,原子发射检测器（AED）,硫化学发光检测器（SC）和脉冲火焰光度检测器（PFPD）等。其中硫化学发光检测器能较好地检测液化石油气中的各种形态硫化物。此外,液相色谱法,燃烧－离子色谱法,极谱法和核磁共振法等也可用于硫化物的分析。     

燃煤电厂融合多信号光纤火焰检测器的开发研究

介绍一种新型光纤燃煤炉火焰检测器，阐述其系统组成及特点，并提出了基于模糊推理的多信号融合处理方法。     

一种提高气相色谱检测灵敏度的新方法——柱头瞬间加压法

本文提出一种提高气相色谱检测灵敏度的新方法-柱头瞬间加压法,探讨对不同化合物在不同加压时间和加压速率条件下对提高灵敏度的影响。实验结果表明,在现有仪器允许的操作范围内,该方法可以使被分析的样品检测灵敏度提高6~7倍。     

Application of light collecting probe with high spatial resolution to spark-ignited spherical spray flames

A light collecting probe named Multi-color Integrated Cassegrain Receiving Optics (MICRO) is applied to spark-ignited spherical spray flames to obtain the flame propagation speed in freely falling droplet suspension produced by an ultrasonic atomizer. Two MICRO probes are used to monitor time-series signals of OH chemiluminescence from two different locations in the flame. By detecting the arrival time difference of the propagating flame front, the flame propagation speed is calculated with a two-point delay-time method. In addition, time-series images of OH chemiluminescence are simultaneously obtained by a high-speed digital CCD camera to ensure the validity of the two-point delay-time method by the MICRO system. Furthermore, the relationship between the spray properties measured by phase Doppler anemometer (PDA) and the flame propagation speed are discussed with three different experimental conditions by changing the fuel injection rate. It was confirmed that the two-point delay-time method with two MICRO probes is useful and convenient to obtain the flame propagation speed and that the flame propagation speed depends on the spray properties.     

基于红外光谱的汽车废气排放诊断技术

提出了红外光谱诊断技术用于诊断汽车废气排放物的温度和组分浓度.进而以分子光谱辐射吸收指数宽带模型为基础,分析研究了火焰温度和组分浓度的红外光谱诊断原理和计算方法,并且进行了试验研究.结果表明该诊断技术不仅可以同步诊断火焰温度和组分浓度,而且实时性和诊断精度也较好.     

基于小波分解与多约束改进的序列图像配准

序列图像配准是光学影像超分辨率重建应用中的关键技术,针对如何提高序列图像超分辨率重建过程中配准的速度和精度问题,提出了一种基于小波分解和改进的多约束准则相结合的配准方法.首先对参考帧和待配准帧进行小波分解,生成小波图像金字塔以缩小搜索空间.其次,从金字塔最高层开始利用由局部灰度熵准则、灰度相似性准则和简化欧式距离比例不变准则构成的改进多约束准则提取同名特征点对,利用最小二乘法计算初始配准参数,然后逐层向下,对配准参数进行修正,实现由粗到精的配准.最后,利用模拟生成图像序列与实际获取图像序列进行测试.实验结果表明该方法在参数获取达到较高精度的情况下能有效提高配准速度,具有较好的效果.     

Characteristics of propagating tribrachial flames in counterflow

The effect of fuel concentration gradient on the propagation characteristics of tribrachial (or triple) flames has been investigated experimentally in both two-dimensional and axisymmetric counterflows. The gradient at the stoichiometric location was controlled by the equivalence ratios at the two nozzles; one of which is maintained rich, while the other lean. Results show that the displacement speed of tribrachial flames in the two-dimensional counterflow decreases with fuel concentration gradient and has much larger speed than the maximum speed predicted previously in two-dimensional mixing layers. From an analogy with premixed flame propagation, this excessively large displacement speed can be attributed to the flame propagation with respect to burnt gas. Corresponding maximum speed in the limit of small mixture fraction gradient was estimated and the curvefit of the experimental data substantiates this limiting speed. As mixture fraction gradient approaches zero, a transition occurs, such that the propagation speed of tribrachial flame approaches stoichiometric laminar burning velocity with respect to burnt gas. Similar results have been obtained for tribrachial flames propagating in axisymmetric counterflow.     

High‐quality imaging in environmental scanning electron microscopy – optimizing the pressure limiting system and the secondary electron detection of a commercially available ESEM

In environmental scanning electron microscopy applications in the kPa regime are of increasing interest for the investigation of wet and biological samples, because neither sample preparation nor extensive cooling are necessary. Unfortunately, the applications are limited by poor image quality. In this work the image quality at high pressures of a FEI Quanta 600 (field emission gun) and a FEI Quanta 200 (thermionic gun) is greatly improved by optimizing the pressure limiting system and the secondary electron (SE) detection system. The scattering of the primary electron beam strongly increases with pressure and thus the image quality vanishes. The key to high‐image quality at high pressures is to reduce scattering as far as possible while maintaining ideal operation conditions for the SE‐detector. The amount of scattering is reduced by reducing both the additional stagnation gas thickness (aSGT) and the environmental distance (ED). A new aperture holder is presented that significantly reduces the aSGT while maintaining the same field‐of‐view (FOV) as the original design. With this aperture holder it is also possible to make the aSGT even smaller at the expense of a smaller FOV. A new blade‐shaped SE‐detector is presented yielding better image quality than usual flat SE‐detectors. The electrode of the new SE detector is positioned on the sample table, which allows the SE‐detector to operate at ideal conditions regardless of pressure and ED.