钠钾合金高温热管吸热器空穴抑制及相变耦合机理研究

With Na-K alloy high temperature heat pipe receiver used as heat absorption for space solar dynamic power generation system, its thermal efficiency, working stability and reliability can be greatly improved, which is very important for low-earth orbit and high-power space station to ensure the stable electricity power output. In this project, the mechanism of void cavity suppression and phase change coupling for Na-K alloy high temperature heat pipe receiver will be explored. Axial groove Na-K alloy high temperature heat pipe appllied to space microgravity conditions will be designed and manufactured. The coupling relationship among start-up characteristics, working temperature and structure of heat pipe will be analyzed. The thermophysical performance of high temperature phase change material will be tested by the harmonic detection-based 3ω method. The high temperature material of phase change and composite phase change applied to heat pipe receiver will be fabricated. The sample for unit Na-K alloy high temperature heat pipe receiver will be designed and manufactured. The experimental platform for the thermal performance of unit Na-K alloy high temperature heat pipe receiver will be set up. The performance of heat absorption and storage under different orbit cycles will be studied. The distribution characteristics of void cavity in phase change canister will be detected. The mechanism of void cavity suppression under the action of heat pipe will be revealed. The thermal storage performance of phase change material canister under normal working conditions of heat pipe during sunlight periods will be detailedly studied. And the start-up characteristics of high temperature heat pipe under the action of phase change material canister after releasing the latent heat during eclipse periods will be detailedly studied too. The phase change coupling mechanism between thermal storage canister and Na-K alloy high temperature heat pipe will be revealed. The research can offer the scientific base for the application of high temperature phase change thermal storage in aerospace.

采用钠钾合金高温热管吸热器作为空间太阳能热动力发电系统吸热器，提高其热效率及工作稳定性和可靠性，对于保证低地轨道运行、电能需求大的空间站稳定电力输出具有举足轻重的作用。本课题探索钠钾合金高温热管吸热器空穴抑制及相变耦合机理，设计及研制适用于空间微重力条件下的轴向槽道式钠钾合金高温热管，分析其启动特性与工作温度和热管结构之间的相互耦合关系，研制适用于热管吸热器的高温相变及复合相变材料，设计及研制单元钠钾合金高温热管吸热器样件，搭建其整体热性能测试平台，分析在不同轨道周期下蓄/放热性能，检测相变容器内空穴分布特征，揭示相变容器在热管作用下的空穴抑制机理，具体分析日照期内在高温热管正常运行下相变材料容器的蓄热性能，阴影期内相变材料容器释放潜热后对高温热管的启动作用，揭示相变容器与钠钾合金高温热管间相变耦合机理，为高温相变蓄热在航天上的应用提供科学依据。

热管吸热器作为空间太阳能热动力发电系统吸热器，提高其热效率及工作稳定性和可靠性，对于保证低地轨道运行、电能需求大的空间站稳定电力输出具有举足轻重的作用。本课题通过建立高温相变蓄热数学和物理模型，对微重力条件下高温热管吸热器进行数值模拟，提供该过程的传热计算方法，分析高温相变蓄热过程空穴热力学行为特性;通过理论推导，得出了不同高温热管吸热器PCM容器径向厚度下单根高温热管上相变蓄热容器外径，并据此分别建立了计算模型，对不同相变蓄热容器径向厚度下的热管吸热器蓄热单元进行了数值计算，并跟NASA 方案进行比较， 为地面热管吸热器高温固液相变蓄热实验提供了有力的分析依据;采用泡沫金属基作为填充材料制作了复合相变材料，搭建了钟形真空腔内填充泡沫金属/石蜡的实验台，研究了不同泡沫金属及孔隙数密度PPI下复合相变材料的热性能，为复合相变蓄热在热管吸热器上的应用提供科学依据。