基于中红外激光吸收谱理论的燃烧气体免标定原位在线协同测量研究

Theoretical and experimental investigation upon combustion has been the fundamental research area of energy and power. As online monitoring of the combustion gases can provide important real-time feedback for combustion control and optimization, it is one of the key steps for major technology developments such as clean utilization of energy, and advanced combustor optimization. Current gas monitoring technology and devices, including those with tunable laser absorption spectroscopy, can satisfy the need for emission monitoring to a certain extent. However, drawbacks in terms of in situ capability, response time, or sensitivity, multi-species monitoring capability, robustness and reliability, are limiting their contributions to real-time, integrated optimization of the combustion systems. Previous work of this project has demonstrated that mid-infrared lasers and multi-wavelength coupling and multiplexing techniques can be used to realize simultaneous monitoring of correlated combustion species, and is capable of obtaining higher sensitivity, stability, and sensor robustness as compared with current technology. This project will study new mid-IR laser based combustion sensing technology from three different aspects: fundamental spectroscopic models, major mechanisms for laser multiplexing and modulation, and sensor demonstration in harsh combustion environments. Precise measurement of the spectroscopic parameters in the mid-infrared region, as well as fiber coupling of mid-infrared lasers will be studied. This project will promote key technology development such as integrated emission control, and advanced energy and power systems.

与燃烧相关的理论与实验研究一直是能源动力领域发展的根本。而燃烧气体的在线监测为燃烧控制和优化提供重要反馈，是能源清洁利用、先进燃烧器设计优化等技术发展的关键环节。包括激光吸收气体测量技术在内的现有燃烧气体检测手段和设备，虽在一定程度上能够满足排放检测要求，但在原位性、响应速度，或准确性、协同性、可靠性等方面存在极大不足，难以满足实时、协同优化的需要。本项目前期工作证明，利用中红外激光和多波长耦合复用系统实现的燃烧气体多组分协同测量，在获得更高精度、稳定性及数据稳健性方面能够突破现有技术瓶颈，发挥光学测量手段优势。本项目将从光谱基本理论、激光调制调谐和信号复用分用等关键技术、恶劣燃烧环境实地测量三方面入手，精确测量未知红外谱线参数并验证光谱模型，阐明中红外多波长激光耦合复用机制，实现高性能指标的燃烧气体免标定原位协同测量。该研究将促进包括污染协同控制、先进能源动力系统在内的相关技术发展。

本项目针对燃烧环境原位定量测量中的重要需求和挑战，发展了基于红外激光吸收光谱技术的燃烧气体免标定原位协同测量方法，顺利完成了项目预期的各项目标，采用理论计算、实验测量与应用系统设计及实现相结合的项目技术路线，在光谱基本理论、激光调制调谐和信号处理方法等关键技术、以及恶劣燃烧环境的测量系统设计实现等三方面均取得了具有代表性的重要进展和成果。项目主要的研究内容总结如下：对光谱理论基础进行了深入研究，以包括一氧化碳、一氧化氮、二氧化碳、水等在内的燃烧小分子气体光谱为对象，对其大量近-中红外谱带谱线进行分析筛选及参数验证，获得谱线最优测量波长组合，提出了一套优化的多波长多组分协同测量方案；发展和验证了具有高噪声免疫性与抗干扰性的多组分免标定原位测量方法，针对高温燃烧协同测量中典型的单一组分多谱线混叠及多组分相邻谱线干扰问题，发展了一套有效的信号处理算法及调制调谐参数优化方法，对高温高压条件的不同线强和低跃迁能量（测温灵敏性）实现优化，有效提取吸光度信号，从而实现对温度和浓度的准确定量测量；实现了在复杂燃烧环境下的多点多组分协同测量，搭建多组分测量系统，并对模型燃烧室密闭空间、复杂湍流燃烧场等复杂现场测量条件，设计搭建了多组分光纤耦合系统、单端漫反射测量系统等，最终获得了高可信度的多组分测量结果，实现了恶劣环境下的有效测量，对相关燃烧基础及应用研究具有重要的借鉴意义。项目研究期间在高水平SCI期刊发表学术论文3篇，培养了4名博士研究生，累计参加国内外学术会议14次，做口头及邀请学术报告9次。