基于蒙特卡洛算法的定日镜场的优化设计

Optimization Design of Heliostatic Mirror Field Based on Monte Carlo Algorithm

摘要: 针对定日镜场的优化设计问题，本文首先建立阴影挡光效率模型，结合蒙特卡洛与光线追踪法求解阴影遮挡效率；根据太阳高度角、太阳方位角求解余弦效率、法向直接辐射照度等，得出光学效率与定日镜场的输出热功率。其次，建立以单位面积定日镜输出热功率最大为目标的非线性目标规划模型。在给定相邻定日镜间距的范围内，求得定日镜场中每一圈层的定日镜数目与相邻定日镜的间距大小；采用Campo布置方法确定定日镜坐标，利用阴影挡光效率模型，当额定年平均输出热功率达到60 MW，求得吸收塔位置坐标(0, 0, 80)，定日镜尺寸(宽 × 高)为(6 m × 6 m)，安装高度为4 m，定日镜总数为2475面，定日镜场总面积为89,100 m²。利用Campo方法确定定日镜场中的定日镜排列方式，能够在简化定日镜场的条件下更为简单的求解定日镜的具体坐标。最后，保持额定功率不变，设计定日镜尺寸为(7 m × 7 m)、安装高度为4 m来达到更大单位面积输出热功率。

Abstract: Aiming at the optimization design problem of heliostat field, in this paper, the shadow blocking efficiency model is first established, which combines with Monte Carlo and ray tracing method to solve the shadow blocking efficiency. According to the solar altitude Angle and solar azimuth Angle, cosine efficiency and direct irradiance of normal phase are solved, get the optical efficiency and the output thermal power of heliostatic field. Secondly, a nonlinear target programming model with the maximum output thermal power of heliostat per unit area is established. Within the range given the spacing of adjacent heliostats, the number of heliostats in each circle and the distance between the adjacent heliostats in the heliostats field are obtained. The coordinates of heliostat were determined by Campo’s arrangement method. When the rated annual average thermal output power reached 60 MW, using the shadow blocking efficiency model, the position coordinate of the absorber is (0, 0, 80), and the heliostat size (W × H) is (6 m × 6 m), the installation height is 4 m, the total number of heliostats is 2475, and the total number of heliostats field is 89,100 m². Using Campo method to determine the heliostat arrangement in heliostat field, the specific coordinates of heliostat can be solved more easily under the condition of simplifying heliostat field. Finally, it keeps the rated power unchanged, designs helioscope size of (7 m × 7 m), installation height of 4 m to achieve a large unit area of thermal output power.