铁基氧化物微颗粒的光谱辐射特性

Spectral radiation property investigation of iron based oxide micro-particles

太阳能热化学制氢过程中金属氧化物颗粒物性随反应温度、波长以及组分发生改变且其对反应过程的能量传递起着重要的作用。为了获得金属氧化物的光谱辐射特性,搭建了光谱透反射测量系统。首先,通过一系列实验测量校核了该系统测量结果的精确性以及稳定性。其次,研究了含有Ni Fe2O4金属氧化物颗粒的溴化钾压片在光谱区间0.3~1.2μm的透过率。结果表明:该系统具有良好的测试精度;Ni Fe2O4压片的透过率随波长的增大而增大,随厚度的增大而减小;在部分光谱处均存在透过率振荡现象,意味着颗粒在该波段区间存在吸收效果。上述研究为太阳能热化学制氢过程中的反应颗粒的辐射特性的反演提供了实验基础,同时也为太阳能反应器内传热、传质模型的建立提供了理论基础。

The radiative property of metallic oxide during solar hydrogen production process varies with reaction temperature, wavelength and component and it plays a important role during energy transfer process. In order to acquire the spectral radiative property of metallic oxide during 0.3-1.2μm, an experimental system is built. Some experiments are applied to validate the measuring accuracy of this system. Then the transmittance of NiFe2O4 particles are obtained based on KBr pellet method. The experimental results show that the system has a good performance on radiative measurement. The transmittance of sample increases with increase of wavelength and decreases with increase of sample thickness. There are manylocalized fluctuations are also observed in all sample types, which suggesting possible sharp peaks in the absorption coefficient of iron based oxide at these wavelengths. The above investigation will provide a base for a detailed radiative transfer analysis to quantify the radiative properties, like extinction coefficient, scattering albedo and scattering phase function,etc., and provide the basis for developing heat transfer model in thermo-chemical hydrogen production process in the future.