【摘要】 燃气轮机工作时燃烧室内充满高温燃气，在基于单波长红外辐射的燃烧室壁面测温中，燃气分子对探测信号存在光谱选择性吸收，因此需深入研究其影响机制以提高测温精度。综合考虑燃气分子的光谱特性及燃烧室流场的非均匀性，基于比尔-朗伯定律和逐线积分法，建立了燃气光谱吸收计算模型;结合燃烧室内部流场的非均匀分布特征，构建了沿探测路径的高温燃气辐射传递模型。在单色测温法基础上，进一步发展了壁面红外测温模型，该模型有效修正了高温燃气辐射及背景辐射对测温精度的干扰。以典型燃气轮机燃烧室模型为研究对象，在标准工况下开展流场数值模拟，系统分析了探测位置、探测角度、探测波长及滤波片半峰宽对燃烧室壁面红外测温结果的影响。结果表明:引入燃气辐射和高温背景辐射的修正算法后，测温精度显著提升;由于燃气组分体积浓度梯度和温度分布的非均匀性显著，导致在燃烧室前端与尾部区域探测器的测温误差较大;综合考虑燃气透过率和红外探测器信噪比，探测器中心波长应选择2.2μm，半峰宽大于50 nm。更多还原

【Abstract】 During gas turbine operation,the combustor is filled with high-temperature gas. In singlewavelength infrared thermometry of combustor walls,the spectral-selective absorption of gas molecules affects detection signals,necessitating in-depth research on its influence mechanism to improve measurement accuracy. The spectral characteristics of gas molecules and the non-uniformity of combustor flow fields were considered comprehensively. Based on the Beer-Lambert law and line-by-line integration method,a gas spectral absorption calculation model was established. Combined with the non-uniform distribution characteristics of the internal flow field,a high-temperature gas radiation transfer model along the detection path was developed. Building upon single-color thermometry,an improved wall infrared thermometry model was proposed,effectively correcting interference from high-temperature gas radiation and background radiation on measurement accuracy. Taking a typical gas turbine combustor model as the research object,numerical simulations of the flow field under standard operating conditions were conducted to systematically analyze the influence of detection position,angle,wavelength,and filter bandwidth( FWHM) on infrared thermometry results of combustor walls. The results indicate that the modified algorithm,which incorporates corrections for gas radiation and high-temperature background radiation,significantly enhances temperature measurement accuracy. Due to the pronounced non-uniformity in gas component volume concentration gradients and temperature field distribution,the temperature measurement error of the detector is relatively large in both the front and rear regions of the combustion chamber. Taking into comprehensive consideration gas transmittance and the signal-to-noise ratio of the infrared detector,the central wavelength of the detector should be selected as 2. 2 μm,with a recommended full width at half maximum( FWHM) greater than 50 nm.更多还原