Research on laser online monitoring equipment for high-temperature corrosive gas in coal-fired boilers
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摘要:
燃煤锅炉燃烧场的经济性、安全性和环保性对于智慧电厂建设具有重要意义。H2S和CO是燃煤锅炉燃烧场的两种主要高温腐蚀气体，它们不仅腐蚀锅炉近壁面，尾气对大气环境的危害也极其严重。基于近红外可调谐半导体 吸收光谱技术，结合波长调制光谱技术和频分复用技术，研制了一款无人值守的燃煤锅炉主燃区的H2S和CO气体浓度实时在线监测设备。仿真模拟了
6335 ~6341 cm−1范围内的气体吸收光谱，并选定1.5 μm附近的近红外 器作为 光源。研制了一套耐高温耐腐蚀的Herriott型多光程池，使 与气体相互作用的有效光程达15 m；开发了硬件电路及相应的固件程序，实现了H2S和CO吸收光谱信号的二次解调与浓度反演。线性度和Allan方差实验表明，其线性拟合相关系数分别为0.9998 和0.9995 ，在73 s和53 s的积分时间下，H2S和CO的最低检测极限分别为0.2×10−6 mol/mol和0.344×10−6 mol/mol。最后，将研制的设备在某300 MW电负荷的四角切圆燃煤锅炉主燃区燃烧气氛场进行应用示范，对水冷壁附近的H2S和CO进行同步测量。结果表明，锅炉中H2S和CO的浓度呈正相关，厌氧燃烧会导致两种气体的含量增加，造成对水冷壁的腐蚀。Abstract:The coal-fired boiler combustion process's economic, safety, and environmental performance holds great significance when constructing smart power plants. In coal-fired boiler combustion, H2S and CO are the two main high-temperature corrosive gases. They not only corrode the boiler near the wall surface but also pose severe harm to the atmospheric environment through their exhaust gases. Based on the near-infrared tunable diode laser absorption spectroscopy technology, combined with wavelength modulation spectroscopy and frequency division multiplexing technology, an unstaffed online real-time monitoring instrument for H2S and CO gas concentrations in the main combustion zone of coal-fired boilers was developed. Gas absorption spectroscopy in the
6335 ~6341 cm−1 range was simulated, and two near-infrared lasers near 1.5 μm were selected as the laser source. A high-temperature resistant and corrosion-resistant Herriott-type multi-pass cell was developed to attain an effective optical path length of 15 m for the interaction between laser and gas. Hardware circuits and corresponding firmware programs were developed to attain secondary demodulation of the absorption spectroscopy signals of H2S and CO and concentration inversion. The linearity and Allan variance experiments showed linear fitting correlation coefficients of0.9998 and 0.9995. At 73 s and 53 s integration times, the minimum detection limits for H2S and CO were 0.2×10−6 mol/mol and 0.344×10−6 mol/mol, respectively. Finally, the developed instrument was applied in the combustion atmosphere of the main combustion zone of a 300 MW tangential four-corner coal-fired boiler, and synchronous measurements of H2S and CO near the water-cooled wall were conducted. The results indicated a positive correlation between the concentrations of H2S and CO in the boiler, with anaerobic combustion leading to an increase in the content of these gases and causing corrosion to the water-cooled wall. -
图 3 H2S和CO吸收信号的幅度与标准气体浓度的关系
Figure 3. The relationship between the amplitude and standard gas concentration for H2S and CO absorption signals
图 4 10×10−6 mol/mol的H2S和100×10−6 mol/mol的CO吸收信号的Allan方差随积分时间的变化情况
Figure 4. Allan variance of 10×10−6 mol/mol H2S and 100×10−6 mol/mol CO absorption signals varying with integration time
图 5 现场测量48 h的H2S和CO浓度数据
Figure 5. On-site measurement data of H2S and CO concentrations for 48 hours
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[1] 陈颖, 胡天丁, 刘云利, 等. 二氧化硫在化学资源化利用中的研究进展[J]. 应用化学,2022,39(2):223-234.CHEN Y, HU T D, LIU Y L, et al. Research progress on chemical resourse utilization of sulfur dioxide[J]. Chinese Journal of Applied Chemistry, 2022, 39(2): 223-234. (in Chinese). [2] XIONG X H, CHEN F L, LI L Y, et al. Water wall tubes’ high temperature corrosion root cause investigation: a 300 MW level boiler case[J]. Energies, 2023, 16(4): 1767. doi: 10.3390/en16041767 [3] CAO L T, PENG R, DENG ZH Y. Optimization study on high-temperature corrosion prevention of the water wall of a 1000 MW dual circle tangential boiler during operation[J]. Energy Reports, 2021, 7: 915-925. doi: 10.1016/j.egyr.2021.09.181 [4] 齐骥, 相佳雯, 林栋, 等. 微流控技术在海洋分析监测中的应用研究[J]. 分析化学,2023,51(10):1545-1556.QI J, XIANG J W, LIN D, et al. Applications of microfluidic technology in marine analysis and monitoring[J]. Chinese Journal of Analytical Chemistry, 2023, 51(10): 1545-1556. (in Chinese). [5] 曲艺. 大气光学遥感监测技术现状与发展趋势[J]. 中国光学,2013,6(6):834-840.QU Y. Technical status and development tendency of atmosphere optical remote and monitoring[J]. Chinese Optics, 2013, 6(6): 834-840. (in Chinese). [6] 刘明言, 石秀顶, 李天国, 等. 电化学分析方法检测重金属离子研究进展[J]. 应用化学,2023,40(4):463-475.LIU M Y, SHI X D, LI T G, et al. Research progress in detection of heavy metal ions by electrochemical analysis[J]. Chinese Journal of Applied Chemistry, 2023, 40(4): 463-475. (in Chinese). [7] XIONG X H, LV ZH M, YU SH L, et al. Coke preheating combustion study on NOx and SO2 emission[J]. Journal of the Energy Institute, 2021, 97: 131-137. doi: 10.1016/j.joei.2021.04.007 [8] 杨舒涵, 乔顺达, 林殿阳, 等. 基于可调谐半导体 吸收光谱的氧气浓度高灵敏度检测研究[J]. 中国光学(中英文),2023,16(1):151-157. doi: 10.37188/CO.2022-0029YANG SH H, QIAO SH D, LIN D Y, et al. Research on highly sensitive detection of oxygen concentrations based on tunable diode laser absorption spectroscopy[J]. Chinese Optics, 2023, 16(1): 151-157. (in Chinese). doi: 10.37188/CO.2022-0029 [9] 黄慧, 周亦辰, 彭宇, 等. 基于量子级联 器中红外光谱技术的幽门螺旋杆菌呼气诊断的可行性研究[J]. 分析化学,2022,50(9):1328-1335.HUANG H, ZHOU Y CH, PENG Y, et al. Feasibility study of breath diagnosis in helicobacter pylori based on quantum cascade laser mid-infrared spectroscopy[J]. Chinese Journal of Analytical Chemistry, 2022, 50(9): 1328-1335. (in Chinese). [10] GUO Y CH, QIU X B, LI N, et al. A portable laser-based sensor for detecting H2S in domestic natural gas[J]. Infrared Physics & Technology, 2020, 105: 103153. [11] 谢耀, 华道柱, 齐宇, 等. GFC-IFC技术在多组分微量气体分析中的应用[J]. 中国光学,2021,14(6):1378-1386. doi: 10.37188/CO.2021-0064XIE Y, HUA D Z, QI Y, et al. Applications of GFC-IFC in trace multi-component gas analysis[J]. Chinese Optics, 2021, 14(6): 1378-1386. (in Chinese). doi: 10.37188/CO.2021-0064 [12] RAZA M, XU K, LU ZH M, et al. Simultaneous methane and acetylene detection using frequency-division multiplexed laser absorption spectroscopy[J]. Optics & Laser Technology, 2022, 154: 108285. [13] 李文婷, 吴涛, 闫宏达, 等. 基于射频白噪声的离轴积分腔输出光谱的大气CH4和CO2的监测[J]. 光学学报,2023,43(24):2401013.LI W T, WU T, YAN H D, et al. Monitoring of atmospheric CH4 and CO2 by off-axis integrating cavity output spectra based on RF white noise[J]. Acta Optica Sinica, 2023, 43(24): 2401013. (in Chinese). [14] ZHENG K Y, ZHENG CH T, YAO D, et al. A near-infrared C2H2/CH4 dual-gas sensor system combining off-axis integrated-cavity output spectroscopy and frequency-division-multiplexing-based wavelength modulation spectroscopy[J]. Analyst, 2019, 144(6): 2003-2010. doi: 10.1039/C8AN02164C [15] POGÁNY A, WERHAHN O, EBERT V. Measurement of ammonia line intensities in the 1.5 µm region by direct tunable diode laser absorption spectroscopy[J]. Journal of Quantitative Spectroscopy and Radiative Transfer, 2021, 276: 107884. doi: 10.1016/j.jqsrt.2021.107884 [16] 彭志敏, 杜艳君, 贺拴玲, 等. 350 MW四角切圆锅炉水冷壁高温腐蚀及H2S在线监测预警[J]. 锅炉技术,2022,53(6):1-7.PENG ZH M, DU Y J, HE SH L, et al. High temperature corrosion of water wall of 350 MW tangentially fired boiler and H2S online monitoring and early warning[J]. Boiler Technology, 2022, 53(6): 1-7. (in Chinese). [17] YU B, WU X, ZHANG M H, et al. Tunable diode laser absorption spectroscopy for open-path monitoring gas markers in fire combustion products[J]. Infrared Physics & Technology, 2023, 131: 104690. [18] 朱晓睿, 卢伟业, 饶雨舟, 等. TDLAS直接吸收法测量CO2的基线选择方法[J]. 中国光学,2017,10(4):455-461. doi: 10.3788/co.20171004.0455ZHU X R, LU W Y, RAO Y ZH, et al. Selection of baseline method in TDLAS direct absorption CO2 measurement[J]. Chinese Optics, 2017, 10(4): 455-461. (in Chinese). doi: 10.3788/co.20171004.0455 [19] 龙江雄, 张玉钧, 邵立, 等. 基于可调谐二极管 吸收光谱的气池光程可溯源测量[J]. 光谱学与光谱分析,2022,42(11):3461-3466.LONG J X, ZHANG Y J, SHAO L, et al. Traceable measurement of optical path length of gas cell based on tunable diode laser absorption spectroscopy[J]. Spectroscopy and Spectral Analysis, 2022, 42(11): 3461-3466. (in Chinese). [20] 袁志国, 马修真, 刘晓楠, 等. 利用可调谐 吸收光谱技术的柴油机排放温度测试研究[J]. 中国光学,2020,13(2):281-289. doi: 10.3788/co.20201302.0281YUAN ZH G, MA X ZH, LIU X N, et al. Testing on diesel engine emission temperature using tunable laser absorption spectroscopy technology[J]. Chinese Optics, 2020, 13(2): 281-289. (in Chinese). doi: 10.3788/co.20201302.0281 [21] 钟笠, 宋迪, 焦月, 等. 具有复杂光谱特征的丙烯气体的TDLAS检测技术研究[J]. 中国光学,2020,13(5):1044-1054. doi: 10.37188/CO.2019-0203ZHONG L, SONG D, JIAO Y, et al. TDLAS detection of propylene with complex spectral features[J]. Chinese Optics, 2020, 13(5): 1044-1054. (in Chinese). doi: 10.37188/CO.2019-0203 [22] 连久翔, 周宾, 王一红, 等. 基于高频参考光的频分复用技术实现强干扰下的气体浓度测量[J]. 光学学报,2020,40(16):1630001. doi: 10.3788/AOS202040.1630001LIAN J X, ZHOU B, WANG Y H, et al. Measurement of gas concentration under strong interference by frequency multiplexing based on high-frequency reference signal[J]. Acta Optica Sinica, 2020, 40(16): 1630001. (in Chinese). doi: 10.3788/AOS202040.1630001 [23] 刘倩倩, 郑玉权. 超高分辨率光谱定标技术发展概况[J]. 中国光学,2012,5(6):566-577.LIU Q Q, ZHENG Y Q. Development of spectral calibration technologies with ultra-high resolutions[J]. Chinese Optics, 2012, 5(6): 566-577. (in Chinese). [24] 任颐杰, 颜昌翔, 徐嘉蔚. 增强吸收光谱技术的研究进展及展望[J]. 中国光学(中英文),2023,16(6):1273-1292. doi: 10.37188/CO.2022-0246REN Y J, YAN CH X, XU J W. Development and prospects of enhanced absorption spectroscopy[J]. Chinese Optics, 2023, 16(6): 1273-1292. (in Chinese). doi: 10.37188/CO.2022-0246 [25] QIU X B, WEI Y B, LI J, et al. Early detection system for coal spontaneous combustion by laser dual-species sensor of CO and CH4[J]. Optics & Laser Technology, 2020, 121: 105832. [26] LIAO K X, QIN M, YANG N, et al. Corrosion main control factors and corrosion degree prediction charts in H2S and CO2 coexisting associated gas pipelines[J]. Materials Chemistry and Physics, 2022, 292: 126838. doi: 10.1016/j.matchemphys.2022.126838 [27] FANG B, YANG N N, WANG CH H, et al. Highly sensitive portable laser absorption spectroscopy formaldehyde sensor using compact spherical mirror multi-pass cell[J]. Sensors and Actuators B: Chemical, 2023, 394: 134379. doi: 10.1016/j.snb.2023.134379 [28] 彭志敏, 贺拴玲, 周佩丽, 等. 基于TDLAS的煤粉锅炉水冷壁近壁面CO/H2S同步在线监测[J]. 热力发电,2022,51(10):145-152.PENG ZH M, HE SH L, ZHOU P L, et al. TDLAS-based synchronous on-line measurement of CO/H2S near water wall of a pulverized coal boiler[J]. Thermal Power Generation, 2022, 51(10): 145-152. (in Chinese). [29] 许伟刚, 谭厚章, 刘原一, 等. 水冷壁高温腐蚀倾向判断及H2S近壁面许用浓度研究[J]. 中国电力,2018,51(7):113-119.XU W G, TAN H ZH, LIU Y Y, et al. Research on determination of high temperature corrosion tendency of water walls and limiting concentration range of H2S near walls[J]. Electric Power, 2018, 51(7): 113-119. (in Chinese). -
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