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81.
摘? 要:硫化氢因其有毒有害的特性,在工业生产过程中对其浓度检测具有重要意义。本文以监测天然气脱硫过程中的硫化氢为应用案例,采用可调谐二极管激光吸收光谱技术(TDLAS)作为分析平台进行浓度分析。TDLAS气体分析系统基于分子选择吸收原理、比尔-朗伯定理和波长调制技术,包括分析模块、气体模块和人机交互模块。在应用案例中,采用1570nm激光器,通过气体模块模拟天然气背景产生0-100ppm硫化氢混合气体,采用化学计量学方法计算硫化氢浓度,结果显示该分析系统满足2%FS的测量需求。因此,具有非接触式、反应迅速、测量精确等优点的TDLAS技术满足现在石化行业的痕量气体测量需求。 相似文献
82.
硫化氢具有强烈的毒性和腐蚀性,为了贯彻实施新的国家天然气标准,增强含硫天然气生产的安全性,提高生产效益,对含硫天然气气质的在线监测,尤其是硫化氢含量的监测就显得非常重要。但现有的测量方法或者精度不高,或者操作复杂、运行维护困难。为此,提出了基于可调谐半导体激光器吸收光谱技术(TDLAS)的在线硫化氢分析方法,并采用波长调制(WMS)技术减少杂质的影响和提高测量精度,试制了测量范围为1 000~20 000 μmol/mol的在线分析系统。离线标定和在线测试结果表明该系统最快响应时间仅0.25 s,最大测量误差为1.3%。在川东北某含硫气井进行了较长时间的在线测量,结果显示该系统稳定可靠。结论认为,该系统具有维护成本低和操作方便简单等特点,它的成功运用,有望弥补现有方法的不足,为我国高含硫天然气的安全开采服务。 相似文献
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Giovanni Nisato Hannes Klumbies John Fahlteich Lars Müller-Meskamp Peter van de Weijer Piet Bouten Christine Boeffel David Leunberger Wülf Graehlert Steven Edge Stéphane Cros Paul Brewer Esra Kucukpinar Julia de Girolamo Padmanabhan Srinivasan 《Organic Electronics》2014,15(12):3746-3755
The requirement for evaluating high performance barrier layers with water vapor transmission rates (WVTR) far below 10−3 g/m2 d has been sparked by the growing application of flexible and organic electronics. While several highly sensitive WVTR-measurement techniques are described in the literature, their accuracy and comparability has not yet been tested. There is an absence of direct comparison of these methods. With a growing body of literature referring to different coating and barrier technologies (often under different testing conditions), it is extremely difficult to gather a coherent picture both of the performance of the materials studied and the permeation measurement methods used. In order to clarify these points we report on independent WVTR measurements of the same batch of a high performance barrier film under two sets of conditions in several laboratories with different state-of the-art methods. These methods also include several calcium test set-ups. The results showed that, while some differences are present, there is a remarkable level of agreement between the measurement methods even prior to harmonization. 相似文献
85.
TDLAS甲烷气体检测中驱动信号发生电路的设计 总被引:1,自引:0,他引:1
为了满足TDLAS甲烷气体检测要求,以STM32为核心,结合DAC8830、AD9833和OPA188芯片,设计一个驱动信号发生电路。实验数据表明:低频锯齿波信号和正弦波信号噪声小,有效滤除低频噪声干扰;将低频锯齿波信号与10k Hz正弦波叠加,使信号调制到较高频率,通过二倍频正弦波对检测信号进行分析,满足激光器对气体检测驱动信号的要求。 相似文献
86.
Saptarshi Basu Derek E. Lambe Ranganathan Kumar 《International Journal of Heat and Mass Transfer》2010,53(4):703-714
Classical spectroscopic techniques have been applied in a novel manner to measure the concentration of gas species, water vapor and carbon dioxide, within a narrow channel flow field non-invasively. Tunable diode laser absorption spectroscopy (TDLAS) was used in conjunction with a laser modulated at a high frequency [Wavelength Modulation Spectroscopy (WMS)] tuned to the ro-vibrational transition of the species. This technique measures the absorption profile which is a strong function of the species concentration across short path lengths and small time spans, as in PEM fuel cells during high load cycles. This method has been verified in a transparent circular flow 12 cm path length and a 12 mm rectangular flow channel. Distinct absorption peaks for water vapor and carbon dioxide have been identified, and concentrations of water vapor and carbon dioxide within the test cells have been measured in situ with high temporal resolutions. A comparison of the full-width at half-maximum (FWHM) of the absorption lineshapes to the partial pressure of water vapor and carbon dioxide showed strong relationships, except in the lower partial pressure regions. Test section temperature was observed to have very minimal impact on these curves at low partial pressure values. A porous media like a membrane electrode assembly (MEA) similar to those used in PEM fuel cells sandwiched between two rectangular flow channels was also tested. Some of the scattered radiation off the MEA was observed using a photodiode at high gain, allowing for more localized species detection. The technique was used to monitor the humidity on either side of the MEA during both temperature controlled and super-saturated conditions. The measurements were observed to be repeatable to within 10%. 相似文献
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可调谐激光吸收光谱技术监测燃烧中CO检测方法比较 总被引:1,自引:1,他引:0
可调谐二极管激光吸收光谱(TDLAS)技术是利用二极管激光器的波长调谐特性,获得被选定的待测气体特征吸收谱线的吸收光谱,从而对待测气体进行定性或定量分析.TDLAS技术与开放式的多次反射池相结合,分别利用二次谐波探测方法和自平衡加波长调制的新型检测方法,测量了酒精喷灯火焰的CO浓度.测量结果表明,自平衡加波长调制的新型检测方法与二次谐波检测方法相比,不仅使检测限提高了16.3倍,还有效地消除了激光器、火焰的光强波动影响,可以应用在燃烧控制及喷焰气体CO浓度测量等多个领域. 相似文献
89.
利用调谐二极管激光器吸收光谱和紫外差分吸收光谱原理研制了道边实时监测机动车尾气仪,详细讨论了该仪器对几种主要有害气体如CO,CO2,NOx和HC(分别用NO和丁二烯代表)的测试及校正原理.以及各种环境因素对测试结果的影响.全文分上、下两部分.本部分(下)介绍了该仪器的主要技术难点、创新点和性能参数,报道了用该仪器跟美国MD-LaserTech公司商业化产品在北京测试现场的部分路边测试实验结果,讨论了各种环境因素如天气、车型、季节、车速、路况等对测试结果的影响及校正.对仪器的性能参数跟国外同类仪器比较发现,我们研制的仪器性能略优于国外同类仪器90年代后期水平.本技术拥有完整自主知识产权,填补了国内空白. 相似文献
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