太阳选择性吸收涂层的中温法向发射比测试对比

COMPARISON OF THE NORMAL THERMAL EMITTANCE MEASUREMENT OF SOLAR SELECTIVE COATING AT THE MIDDLE TEMPERATURES

采用紫外-可见光-红外分光光度计、傅里叶红外光谱仪,在室温条件下,测量Mo-SiO2太阳选择性吸收涂层在空气300℃退火前后0.34～25.00μm波长范围内的近法向反射光谱曲线。假设室温和高温条件下光谱反射特性不变,根据基尔霍夫定律计算出涂层在不同温度下的法向发射比。采用辐射计法,测量同一片样品在200℃、300℃时的法向发射比,两种方法得出的数值差异仅为0.02～0.03。经误差分析发现,在保证涂层退火前后反射光谱曲线不变、工作温度不超过300℃的情况下,基于室温反射光谱曲线和中温辐射计法的结果在测试仪器的误差范围内基本等效。

The normal thermal emittance of Mo-SiO2 solar selective coating at 200℃ and 300℃ were measured by spectral reflectance and emission power, respectively. The near-normal reflectance in the wavelength region of 0.34-25μm of the as-deposited and annealed samples were measured with UV-VIS-NIR and FT-IR spectrometers at room temperature. The solar absorptance （α） and the normal thermal emittance （εn） at different temperature are calculated by Kirchhoff＇ s law on the hypothesis of the same spectral reflectance at different temperature, en at 200℃ and 300℃ were also measured by normal relative emission power meter. The difference of measured value was about 0.02-0.03, which showed the equivalence of spectral reflectance and emission power meter based on the error analysis.