塔式太阳能定日镜风荷载群体干扰效应研究

塔式太阳能定日镜风荷载群体干扰效应研究(任务书,开题报告,论文说明书15000字)
摘  要
塔式太阳能热发电系统是一种集中式热发电系统，它是在很大面积的场地上装有许多台大型太阳能反射镜，通常称为定日镜，每台都各自配有跟踪机构准确的将太阳光反射集中到一个高塔顶部的接受器上，从而将光能转化为热能。定日镜是整个系统中占投资比很大的部分，也是整个系统的关键部分。因此，应对定日镜上的各种荷载与作用加以研究，使其满足强度、刚度、稳点性的要求得以正常运行。由于定日镜往往采用独立柱式结构，镜面尺寸较大，镜身较薄，定日镜工作时需根据太阳光迹变换仰角及转动，所以定日镜受风载影响很大。从塔式太阳能热发电系统建立开始，定日镜的抗风设计一直是一个难题。塔式太阳能热发电系统通常建立在开阔的场地，定日镜一般呈辐射状，大面积的布置在开阔的场地上。因此，风载的群体干扰效应与一般建筑有很大的不同，相关研究较少，需要进行深入的研究。
本文通过计算流体动力方学对定日镜的风荷载群体干扰效应进行研究。主要研究内容及成果如下：
（1）选取合理的定日镜布置方式，由最不利情况与工作常态共设置了10种工况。
（2）根据计算得出这10种工况的表面风压系数分布、风速分布、以及风速流线图。将所得计算数据进行分析并与已有的风洞实验数据相对比，验证有效性。分析所得出的数据，研究定日镜间干扰状况。
（3）定日镜之间由于相互干扰，表面风压分布特征与单个定日镜表现出显著差异，需要在相关设计中引起重视。
关键词：定日镜；风压分布；数值模拟；群体干扰
 
Abstract
Tower solar thermal power generation system is a centralized thermal power generation system. It is equipped with many large-scale solar reflectors on a large area of the site, usually called heliostats, each of which is equipped with a tracking mechanism accurately. The reflection of sunlight is concentrated on a receptor at the top of a tall tower, thereby converting light energy into heat energy. Heliostats account for a large portion of the investment in the entire system and are a key part of the overall system. Therefore, the various loads and effects on heliostats should be studied so that they can meet the requirements for strength, stiffness, and stability. Because heliostats often use an independent column structure, the mirror size is relatively large, the mirror body is thin, and the heliostat needs to change the elevation angle and rotation according to the solar light track. Therefore, the heliostat is greatly affected by the wind load. Since the establishment of tower solar thermal power systems, the design of heliostats has always been a challenge. Tower-type solar thermal power systems are usually built on open fields, where heliostats are generally radiating and large areas are laid out on open fields. Therefore, the wind-borne group interference effect is very different from that of general buildings and related research is less, more specific researches are wanted.
In this paper, the effect of wind-borne population interference on heliostats is studied by computational fluid dynamics. The main research contents and results are as follows:
(1) Selecting a reasonable arrangement of heliostats, a total of 10 working conditions were set from the most unfavorable conditions and working normal.
(2) Calculating the surface wind pressure coefficient distribution, wind speed distribution, and wind speed streamline diagram for these 10 operating conditions. The calculated data was analyzed and compared with the existing wind tunnel experiment data to verify the validity. Analyze the data obtained and study the interference between heliostats.
(3) Due to the mutual interference between heliostats, the distribution of surface wind pressure shows a significant difference from that of a single heliostat and needs to be taken into account in related designs.
Key Words：heliostat； wind pressure distribution;  numerical simulation； group interference
 

目  录
摘  要    I
Abstract    II
第1章 绪论    1
1.1 研究背景    1
1.1.1 塔式太阳能热发电系统的发展    1
1.2 塔式太阳能研究现状    3
1.2.1 国外研究状况    3
1.2.2 国内研究状况    4
1.3 本文的研究目的及意义    4
第2章 计算原理及数值模型    6
2.1 控制方程    6
2.2 湍流模型    6
2.2.1 模型    6
2.2.2 模型    8
2.3 几何模型    9
2.3.1几何参数    9
2.3.2工况设置    9
2.3.3边界条件    10
2.4 数值模型    11
2.4.1模型建立    11
2.4.2网格划分    12
2.4.3计算准备    13
第3章 定日镜风荷载群体干扰效应    14
3.1 有效性验证    14
3.2 90°仰角的风速及风压分布    16
3.2.1 0°风向风场特性及风压分布    16
3.2.2 30°风向风场特性及风压分布    18
3.2.3 45°风向风场特性及风压分布    19
3.2.4 60°风向风场特性及风压分布    21
3.2.5 90°风向风场特性及风压分布    23
3.3 60°仰角的风速及风压分布    24
3.3.1 0°风向风场特性及风压分布    24
3.3.2 30°风向风场特性及风压分布    26
3.3.3 45°风向风场特性及风压分布    28
3.3.4 60°风向风场特性及风压分布    30
3.3.5 90°风向风场特性及风压分布    32
3.4 干扰分析    34
3.4.1 90°仰角风压变化    34
3.6.2 60°仰角风压变化    35
第4章 总结与展望    36
4.1 总结    36
4.2 展望    36
参考文献    37
致  谢    39