Abstract Solar reflectors are exposed to outdoor environments where dust accumulation is a primary degrading factor on optical performance. In this study, the effect of dust accumulation on reflectivity at different positions on the reflector of a parabolic trough solar thermal power plant in Hohhot, China was investigated and analyzed. The physical and chemical properties of dust accumulation were tested using a combination of spectrophotometer, scanning electron microscopy, and X-ray diffraction. The results showed that dust accumulation on the bottom edge of the reflector caused the largest decrease in reflectivity compared to dust on the center and top edge. In addition, dust particles at Hohhot were dominated by quartz (SiO2, 53.5%), followed by calcium oxide (CaCO3, 25.4%), and some minor feldspar minerals (NaAlSi3O8, 21.1%). However, some characteristics of the dust could not be determined by experimental measurements. To address this gap, a physical model was proposed to predict the impact of dust accumulation on light reflectivity of the reflector. Different physical parameters of the model are discussed, such as the size of the particles, diaphaneity, the incidence light angle, and tilt angle. The maximum relative deviation between the mathematical model and the experimental results was only 1%.

中文翻译：

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积尘对抛物槽式太阳能聚光器清洁度系数的影响

摘要 太阳能反射器暴露在室外环境中，灰尘堆积是影响光学性能的主要因素。本研究调查分析了呼和浩特某抛物槽式太阳能热电厂不同位置灰尘堆积对反射器反射率的影响。使用分光光度计、扫描电子显微镜和 X 射线衍射的组合测试灰尘堆积的物理和化学性质。结果表明，与中心和顶部边缘的灰尘相比，反射器底部边缘的灰尘堆积导致反射率下降幅度最大。此外，呼和浩特尘粒以石英（SiO2，53.5%）为主，其次是氧化钙（CaCO3，25.4%）和一些次要的长石矿物（NaAlSi3O8，21.1%）。然而，实验测量无法确定粉尘的某些特征。为了弥补这一差距，提出了一种物理模型来预测灰尘积累对反射器光反射率的影响。讨论了模型的不同物理参数，如颗粒大小、透明度、入射光角和倾斜角。数学模型与实验结果的最大相对偏差仅为1%。