可调半导体激光光谱技术（TDLAS）可实现温度、 组分浓度等多参数同时测量, 具有体积小、 响应速度快、 环境适应性高等优点, 逐渐成为燃烧流场诊断的主要手段之一。 TDLAS光谱测量常采用直接吸收技术和波长调制技术, 其中强度归一化的波长调制技术, 适合存在振动、 湍流等致光束偏转效应和强辐射本底等恶劣应用环境条件的燃气轮机流场参数测量。 基于TDLAS技术, 开展了1f归一化波长调制技术燃气轮机燃烧室温度、 组分浓度参数测量方法研究和实验室验证工作, 并在某燃气轮机单喷嘴台架进行了冷态、 热态试验验证, 实现了燃气轮机燃烧室沿气流方向温度及H2O、 CH4浓度二维分布测量。 采用1f归一化波长调制技术抑制台架振动、 热辐射背景噪声, 采用1 392, 1 469和1 343 nm蝶形封装的DFB激光器, 三支激光器的出光方式为时分复用, 选取H2O的7 185.6, 6 807.83和7 444.3 cm-1处的吸收线, 两两组合使用, 测量热态下一定范围内的温度和H2O浓度; 采用1 654 nm蝶形封装的DFB激光器, 选取CH4的6 046.96 cm-1处的吸收线进行冷态CH4浓度测量。 实验室对测量系统可靠性进行验证, 配置4%~6%范围内的CH4气体进行测量并与实际值对比, 浓度测量最大相对偏差为3.72%; 在高温炉中设定900~1 500 K范围内的温度台阶, 充入纯水汽, 计算不同设定温度和压力下的温度和浓度测量值, 温度测量最大相对偏差3.07%, 浓度测量最大相对偏差为-2.00%, 验证了该测量系统的可靠性。 台架燃气轮机实验中, 集成了一套小型化测量仪器, 设计多束激光收发一体的测量结构。 实验采用两个电动位移台, 搭载测量结构, 每间隔5 mm逐点移动采样, 对燃气轮机燃烧室300 mm×60 mm的燃烧区域进行测量, 获取了若干工况下冷热态结果。 通过双三次插值的方法绘制分辨率为0.5 mm的二维流场分布图, 结果分别反映了测量区域范围内CH4和火焰分布的真实状态。 为燃气轮机喷嘴燃料、 空气掺混情况和燃烧特性研究提供了新的研究方法和技术手段。

Tunable diode laser absorption spectroscopy (TDLAS) can realize the simultaneous measurement of multiple parameters such as temperature and component concentration, which has the advantages of small size, fast response and high environmental adaptability, so the technology has gradually become a major tool of combustion flow field diagnosis. TDLAS mainly includes direct absorption spectroscopy and wavelength modulation spectroscopy. Intensity normalized wavelength modulation spectroscopy is suitable for gas turbine flow field parameter measurement under severe application environment conditions, such as beam deflection effect caused by vibration, turbulence and strong thermal radiation background. Based on the TDLAS technology, carry out the 1f normalized wavelength modulation technique methods for measuring the parameters of gas turbine combustor temperature, the concentration of components research and laboratory test. A two-dimensional measurement scheme of temperature and concentration of H2O and CH4 in gas turbine combustor along the airflow direction was designed, and a single nozzle bench test of cold and hot state verification test was carried out. The measurement adopted 1f normalized WMS to restrain the rack vibration and the background noise of thermal radiation. The DFB laser in 1 392, 1 469 and 1 343 nm of butterfly package was used. The light output of the three lasers was time-division multiplexing. The absorption lines at 7 185.6, 6 807.83 and 7 444.3 cm-1 of H2O were selected and used in pairs to measure the temperature and H2O concentration in a certain range under the hot state. The DFB laser in 1 654 nm of butterfly package was employed for the measurement of the cold-state CH4 concentration. The laboratory verified the reliability of the measurement system. The CH4 standard gasin the range of 4%～6% was measured and compared with the actual value. The maximum relative deviation of concentration measurement was 3.72%. A temperature step within the range of 900～1 500 K was set in the high-temperature furnace, pure water vapor was filled in, and the temperature measurement value and concentration under different temperatures and pressures set were calculated. The results showed that the maximum relative deviation of temperature measurement was 3.07%, and the maximum relative deviation of water vapor was -2.00%, which reflected the reliability of the measurement system. In the gas turbine experiment, a set of the miniaturized measuring instrument was integrated, and the measurement structure of multi-beam laser transceiver was designed. In the experiment, two electric displacement tables with measuring structure were used to move at intervals of 5 mm and measure the 300 mm×60 mm combustion area in the combustion chamber of a gas turbine so as to obtain the results of hot and cold states under some conditions. By bicubic interpolation, a two-dimensional flow field map with a resolution of 0.5 mm was drawn. The results showed the real state of CH4 and flame distribution in the measurement area. In this paper, a new research method and technical means were proposed for the study of the mixing of fuel and air and the combustion characteristics of gas turbine nozzles.