基于激光吸收光谱技术的火焰温度二维检测研究

Research on 2D Measurement of Flame Temperature Based on TDLAS Technology

为了实现燃烧场温度的高精度测量,将可调谐半导体激光吸收光谱技术(TDLAS)与计算层析技术(CT)进行结合建立了TDLAT温度测量系统。选用中心波长为1388 nm和1343 nm的DFB激光器,在10 kHz的扫描频率下利用32光路CT测量单元对三喷口燃烧器的甲烷预混火焰进行吸光度测量,并对激光吸收结果进行了二维重建。结果表明:Φ10与Φ8喷口中心温度基本一致,温度最高超过1700 K,Φ6喷口中心温度相对较低,约为1500 K,且火焰面积较小。将重建结果与热电偶结果对比显示,两者温度分布基本吻合,验证了TDLAT技术应用于火焰温度二维测温的可行性与准确性。

In order to achieve high-precision measurement of combustion field temperature,the TDLAT temperature measurement system was established by combining tunable diode laser absorption spectroscopy(TDLAS)and computed tomography(CT).Using DFB lasers with center wavelengths of 1388 nm and 1343 nm,under the scanning frequency of 10 kHz,the 64-path CT measurement unit was used to measure the absorbance of the methane premixed flame of the three-jet burner,and the laser absorption results were reconstructed in 2D.The results show that:the temperature ofΦ10 andΦ8 jet was basically the same.The maximum temperature could exceed 1700 K.The temperature of theΦ6 jet center was relatively low,about 1500 K,and the flame area was small.Comparing the reconstruction results with the thermocouple results,the temperature distribution of the two was basically the same,and the TDLAT technology had higher accuracy and resolution.The feasibility and accuracy of TDLAT technology applied to flame temperature 2D temperature measurement was thus verified.