定日镜积尘度检测比对用的标准板制作方法

Manufacture method of standard boards for the detection and comparison of the dust-accumulation-degree of heliostat

针对目前需要实现定日镜按积尘程度自动匹配清洗策略需求这一问题,该文提出一种定日镜积尘度标准板的制作方法,给出积尘度的标定和分级方法。该文选用粒径115μm的石英粉模拟实际灰尘,为保证灰尘尽量均匀撒落至镜面,通过喷笔将灰尘与酒精混合物喷向定日镜面,酒精挥发后将镜面的浮尘吹落,并称量粉尘镜的质量,通过增加喷灰次数得到镜面单位面积的最大灰尘质量,进而通过反射率测量仪测量粉尘镜面的反射率与其对应。结果表明:镜面单位面积可附着的灰尘质量最多为1.86 g/m2,镜面反射率下降约22.78%。由此将镜面积尘度分为5个级别并可制作相应的积尘度标准板。结果可用来给检测现场定日镜积尘度的仪器做测量前的校准,为提高塔式太阳能发电站清洗及发电效率提供一定的参考。

In order to realize an automatic matching and cleaning strategy requirements of heliostat according to dust-accumulation-degree,this paper has proposed a method of making standard plate for dust-accumulationdegree of heliostat,and has developed a special dust spraying device,and has given a calibrating and grading method of dust-accumulation-degree.Quartz powder with a particle size of 115μm was utilized to conduct the experiments.To ensure that the dust was scattered evenly to heliostat surface,the mixtures of dust and alcohol were sprayed to heliostat surface by the airbrush,and the dust was blown off as the alcohol was evaporated.The mass of heliostat was weighed and maximum dust mass per unit area of heliostat was obtained by increasing the spraying numbers.Furthermore,the reflectivity of heliostat surface with adsorption of the dust was measured by a reflectivity measuring instrument.The experimental results indicated that maximum dust mass per unit area of heliostat was 1.86 g/m2,and the reflectivity was reduced by about 22.78%.The dustaccumulation-degree was divided into five grades and standard boards of dust-accumulation-degree were correspondingly manufactured.The results of this paper can be applied to calibrate the instruments for detecting the dust-accumulation-degree of heliostat before measurement and provide a reference for improving cleaning and generating efficiency in tower solar power stations.