中文摘要：

腔式吸热器是塔式太阳能热发电系统光热转换的关键部件，云层遮挡等非正常瞬态气象条件会引起腔体内热流密度呈现出瞬态阶跃扰动的非连续性特点，易造成腔式吸热器状态参数有较大的动态扰动，严重影响了吸热器的稳定和安全运行。本文基于辐照强度阶跃变化的非连续性特点，综合考虑了压力变动时两相流中的闪蒸和闪凝现象，采用序贯模块法构建了腔式吸热器的动态特性非线性数学模型，获得了辐照强度阶跃扰动时腔式吸热器各耦合输出参数的动态响应规律。这些规律对于腔式吸热器的热力系统及控制系统的设计具有重要的指导意义。

英文摘要：

The solar cavity receiver is an important light-energy to thermal-energy convector in the tower solar thermal power plant system. The heat flux of the inner surface in the receiver will present the characteristics of non-continuous change especially in non-normal and transient weather conditions, which may result in a continuous dynamic variation of the characteristic parameters. Therefore it will seriously affect the stability and safe operation of the receiver. In this paper, on the basis of the non-continuous step change of the radiation flux, we established a non-linear dynamic model by sequential modular approach, which gives a comprehensive consideration of flash or condensation in the two-phase flow. This study has obtained the dynamic responses of the characteristic parameters under step change radiation flux. The results can provide scientific guidance to the safe operation and control of the cavity receiver system.