塔式太阳能热发电站圆月夜聚光实验研究

Experimental Study of Moonlight Concentration of a Solar Tower Power Plant in the Full Moon Night

在塔式太阳能热发电系统中,吸热器采光面上的聚光能流密度分布的测量对优化整个系统的光热性能有着重要意义。本文提出一种基于月光聚光信息的塔式电站定日镜场聚光能流密度分布的间接测量方法。主要介绍2018年9月24日晚在延庆塔式电站开展的两种对月聚光实验:一种是通过塔上布置的照度计标定电荷耦合元件(charge-coupled device, CCD)相机拍摄的光斑图像,得到定日镜场聚光光斑的照度分布;另一种是使聚光光斑扫描过照度计,得到不同时刻的照度计数值,通过高斯拟合得到聚光光斑的照度分布。将聚光光斑的照度分布与月光测光站测得的月光法向直射照度对比,得到塔上聚光光斑的相对能流密度分布。实验结果表明,通过月光聚光实验,可以得到塔式电站的聚光光斑的相对能流密度分布(即聚光比分布),为后续依据太阳和月亮之间的亮度分布关系,转换为日光聚光能流密度分布提供实验数据支持。

In the solar thermal tower power generation system,the measurement of concentrated flux distribution on the receiver aperture is of great significance for optimizing the solar thermal performance of the whole system.In this paper,an indirect measurement method was proposed based on moonlight concentration for the concentrated solar flux distribution of the heliostat field of a tower power plant.Two moonlight concentrating experiments carried out at Yanqing Solar Tower Power Plant in Beijing in the night of September 24,2018,were introduced:one was to obtain the illuminance distribution of the concentrated lunar image taken by a CCD camera and calibrated through the illuminometers arranged on the tower;another was to obtain the illuminance distribution of the concentrated image by moving the image through the fixed illuminometers and then reconstructing the lunar image from the measured illuminance values at different times by Gaussian fitting.And then the relative illuminance distribution of the concentrated lunar image on the tower was obtained by comparing the illumination distribution with the direct normal illumination of the moonlight measured by the moonlight measuring station.The moonlight concentrating experiments showed that the relative flux distribution(ie,the concentration ratio distribution)of the concentrated lunar image of the tower power plant can be obtained,which provided experimental data support for the subsequent conversion to the solar flux distribution according to the brightness distribution relationship between the sun and the moon.