A solar cavity receiver is an essential apparatus to achieve solar-thermal conversion in a solar thermal power tower station. Its basic structure is shown in Figure 1. In the solar cavity receiver, several evaporating heating surfaces and superheating surfaces that consist of single parallel panel or multiple parallel panels are arranged in the solar cavity receiver. Evaporating heating surfaces are applied to make working fluid (water) saturated, and the saturated steam is turned into superheated steam to achieve the requirements of steam turbine generation by flowing through superheating surfaces. To improve the solar-thermal conversion, a membrane panel that is made up of several thin-walled tubes is parallel welded together and connected with a horizontal larger diameter manifold is applied on the heating surfaces.^1,2 This panel is a basic component of the cavity receiver. Its constituent parallel tubes are called risers, which are connected to a larger diameter manifold placed horizontally. The radiation heat flux in the cavity receiver is always non-uniform temporally and spatially due to one-target focus type of the heliostat field and astronomical feature of sunlight. The structure of the parallel panel and the non-uniform heat flux distribution may lead to the instability of thermo-hydraulic characteristics of phase-change heat transfer fluid in the solar cavity receiver.

中文翻译：

---

集中热流下太阳能腔体集热器热工水力特性优化

太阳能腔体接收器是塔式太阳能热发电站实现光热转换的重要装置。其基本结构如图1所示。在太阳能腔体接收器中，太阳能腔体接收器内设置有多个由单块平行板或多块平行板组成的蒸发受热面和过热面。利用蒸发受热面使工质（水）饱和，饱和蒸汽流过过热面变成过热蒸汽，达到汽轮机发电的要求。为了提高光热转换，在受热面上采用了由多根薄壁管平行焊接而成的膜板，并与水平的大直径歧管连接。^1,2该面板是腔体接收器的基本组件。其组成的平行管称为立管，连接到水平放置的较大直径歧管。由于定日镜场的单目标焦点类型和太阳光的天文特征，腔体接收器中的辐射热通量在时间和空间上总是不均匀的。平行板的结构和不均匀的热通量分布可能会导致太阳能腔体接收器中相变传热流体的热工水力特性不稳定。