Measurement of gaseous hydrocarbon distribution by a near-infrared absorption tomography system
Measurement of gaseous hydrocarbon distribution by a near-infrared absorption tomography system
复制标题
近红外吸收断层扫描系统测量气态烃分布
DOI：
10.1117/1.1377306
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发表时间：
2001
期刊：
影响因子：
--
通讯作者：
H. McCann
中科院分区：
文献类型：
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作者：
F. Hindle;S. Carey;K. Ozanyan;D. Winterbone;E. Clough;H. McCann
化学物质的空间分布可以是化学反应器性能的关键决定因素。内燃机燃烧室内空燃比的空间变化对燃油效率和排放有重要影响。本文报道了一种基于光纤的近红外吸收层析成像系统的研制，用于测量缸内碳氢化合物的分布。它已成功地应用于不稳定注气。该技术利用了1.7 μm辐射的特定（但较弱）碳氢化合物吸收，该波长直到最近才通过固态全光电元件的可用性而变得可用。还部署了一个标准的电信激光器来测量参考信息。测量空间由32个双波长光纤耦合测量路径采样。两个测量值之比的对数产生烃吸收的路径积分，从而产生浓度的路径积分。路径积分通常以28 dB信噪比（SNR）测量。单通道特性表明，该技术很容易校准的温度和压力的影响，在70-150°C和1- 10巴的区域。不同的气态烃流的层析重建已实现与D/5的顺序，其中D是容器直径的空间分辨率。时间分辨率约为每秒1,000帧。
The spatial distribution of chemical species can be a critical determinant of chemical reactor performance. The spatial variation of air-fuel ratio in a combustion chamber of an Internal Combustion engine has significant influence on fuel efficiency and emissions. We report the development of a fibre-based Near Infra-Red Absorption Tomography system, to measure the distribution of hydrocarbons in-cylinder. It has been successfully applied to transient gas injections. The technique exploits the specific (but weak) hydrocarbon absorption of 1.7 μm radiation, which wavelength has only recently become accessible by availability of solid-state all-optoelectronic components. A standard telecommunications laser was also deployed to measure reference information. The measurement space is sampled by 32 dual-wavelength fibre-coupled measurement paths. The logarithm of the ratio of the two measurements yields the path integral of the hydrocarbon absorption, and hence, of concentration. The path integral is measured with typically 28dB signal-to-noise ratio (SNR). Single-channel characterisation shows that the technique is readily calibrated for temperature and pressure effects, over the region 70–150°C and 1-10bar. Tomographic reconstruction of different gaseous hydrocarbon flows has been achieved with spatial resolution of the order D/5, where D is the vessel diameter. Temporal resolution of about 1,000 frames per second is demonstrated.