中文摘要：

腔式吸热器是太阳能塔式热发电系统中光热转换的重要设备，由于其长期在高密度、非均匀辐射热流条件下工作，因此对其性能进行研究具有重要意义。本文对腔式吸热器的整体结构和吸热面进行了设计，采用改进的蒙特卡罗法与对流换热耦合的方法模拟了腔体内部热流密度分布，分析了吸热管束内部汽液两相流的流量、温度、以及管壁表面温度等参数的变化规律，从而对不同位置的换热系数进行预测，比较全面地认识吸热器整体性能。

英文摘要：

As an important light-energy-to-thermal-energy convector in the tower solar thermal power plant system, a solar cavity receiver is apt to be operated under the condition of high-density, non-uniform heat radiation flux frequently. So it is significant to understand the mechanics of boiling heat transfer in it for its design. In this paper, after a prototype of the cavity receiver and its inner heated surface are determined, a model of simulating its inner heat flux is proposed by using the modified Monte Carlo method coupled with the convection heat transfer. The influences of flow rate, fluid temperature involved in vapor-liquid two-phase flow, and the tube wall temperature are accounted for. The profile of heat transfer coefficient can be obtained at any position along the flow direction. That will help us to have more comprehensive understanding about the overall heat transfer performance of the solar cavity receiver.