基于可调谐半导体激光器吸收光谱的温度测量方法研究

Temperature measurements based on tunable diode laser absorption spectroscopy

介绍了基于半导体激光器作光源的吸收光谱测温技术研究和开发集成的系统,利用H_2O在1.4μm附近的吸收线对的线强比值来反演温度.介绍了该系统在实验室管式高温上的标定和开放炉管的测量验证,结果显示各设置温度下测量温度波动平均在50 K左右.之后在CH_4/空气预混平焰炉上进行进一步验证,发现在吸收线7153.7 cm^(-1)长波一侧出现了HITRAN08中未给出的几条H_2O吸收和该吸收线重叠.HITEMP中在这些波长上有对应的吸收线给出,但对另一条选用的吸收7154.354 cm^(-1),给出的可对应吸收线中心频率和测量不一致.根据实验测量结果和HITRAN/HIlTEMP的对比,对选择吸收线对的位置和线强等参数继续采用实验室标定结果,并引入HlTEMP中给出的这些高温下表现出来的吸收线参数,在平焰炉不同当量比状态下做了测量对比.

The thermometry based on absorption spectroscopy and developing of a temperature sensor is introduced, in which temperature is retrieved by measuring line strength ratio between a pair of absorptions of water vapor near 1.4μm. The temperature sensor is first calibrated on a tubular furnace and then used to verify measurement results with the heating tube whose both sides are open, an average fluctuation of about 50 K is obtained at each temperature setpoint. Some new absorption lines of H2O near one absorption （centered at 7153.7 cm^-1） of the selected line pair are observed during demonstration measurements for CH4/air flat flame burner. These absorption lines overlapping with 7153.7 cm^-1, are not listed in HITRAN08 database while HITEMP data give absorption information about these wave number positions. But line center of the other absorption （centered at 7154.354 cm^-1） in HITEMP seems different from our measurement and HITRAN database. A combination of our calibrated results from tubular furnace and line parameters of new features from HITEMP is chosen and some results measured at different equivalence ratios on the burner are shown here.