TDLAS测量甲烷/空气预混平面火焰温度和H_2O浓度

Temperature and water vapour concentration measurements of CH_4/Air premixed flat flame based on TDLAS

基于可调谐二极管激光器吸收光谱技术（YDLAS）建立了温度和H2O浓度测量系统，利用光谱数据库Hitran2004在1393nm附近选择了在500～1300K有很高测温灵敏度的两条水吸收线：7168．437cm^-1，7185．597cm^-1。在1kHz的扫描频率下，利用直接吸收-扫描波长法对甲烷／空气预混平面火焰进行测量，并进行边界层修正，与热电偶的对比结果显示，在温度区间1100～1350K，两者最大相差80K（6．7％）；水蒸气组分浓度与计算值平均相差小于0．02（10％）．

A sensor based on tunable diode laser absorption spectroscopy （TDLAS） was constructed for temperature and water vapor concentration measurement. Absorption lines were selected and analysed using spectrum database Hitran2004. Two fiber-coupled near infrared distributed feedback lasers was used to probe two water vapor absorption features （7168.437 cm^-1 and 7185. 597 cm^- 1 ） near 1393nm which has high sensitivity of temperature measurement in 500 - 1300K. Successful experiments were performed in a CH4/Air premixed flat flame burner using direct absorption wavelength scanned method at a 1kHz scan rate. Because of the cooler shear layer in the flat flame, mixing layer theory was applied to correct TDLAS results. Comparison with thermoeouple measurements,the max difference of both methods is less than 80K （6.7%）. Comparison with calculation, the average water mole fraction difference is less than 0.02（ 10% ）.