液氮至液氦温区低温脉动热管传热与流动研究

Cryogenic Oscillating Heat Pipe (COHP) is a new-type heat pipe. It is suited for cooling superconducting magnet, electronic device and harvesting energy because its great heat transport ability, strong adjustability, small in size and simple construction. But the experimental research on COHP from liquid nitrogen to liquid hydrogen temperature is little, not to mention the COHP at liquid helium temperature. Physical and mathematical model of COHP are established in this project and correlation equation is solved to analyze the effect of main parameter on heat transfer and flow. The experimental platform is completed and experimental research is done to analyze the effect of geometric, operational and physical parameters such as pipe diameter, filling ratio, inclination angles and the position of heating. Through the experimental research, the design of COHP is optimized to promote the application. Based on the experimental research, the mathematical model is corrected. At last, the role of driving force, gravity, capillary resistance in COHP is analyzed.

低温脉动热管（COHP）是一种新型热管，与传统热管相比，因其传热性能好、适应性强、体积小、结构简单等优点，在超导磁体冷却、电子散热、能量收集等方面具有更好的发展应用前景。但对于液氮到液氢温区COHP，实验研究数据较少，限制了进一步的深入研究，对于液氦温区COHP的研究更是一片空白。本项目拟就液氮至液氦温区低温脉动热管为研究对象，建立物理模型和数学模型，求解分析主要参数对传热与流动特性的影响。完善补充液氮至液氦温区脉动热管实验平台，在理论指导下进行实验，分析管径、充液率、倾斜角和加热位置、弯头数等几何参数、运行参数及物理参数对低温脉动热管性能可能产生的影响，优化低温脉动热管设计，加速低温脉动热管的应用进程。在实验基础上，修正数学模型，并深入分析驱动力、重力、毛细滞后阻力、汽塞及液塞运动等在低温脉动热管运行中的作用，及参数对传热及流动性能的影响机制。

本项目围绕液氮至液氦温区低温脉动热管展开实验和理论研究。改进完善了制冷机做冷源的低温脉动热管实验平台，设计了一种新型机械热开关，解决了低温脉动热管预冷困难的问题；研制了高传热性能的低温脉动热管，液氦温区脉动热管的有效导热系数可达3600-15000W/mK，远高于固体铜。针对低温脉动热管建立了物理模型和数学模型，通过关联求解分析了主要参数对低温脉动热管的传热与流动特性的影响，研究低温脉动热管启动过程中管内充液与室温充气压力、工质种类、容积的关系，实验分析加热量、充液率和倾斜角度等参数对低温脉动热管性能产生的影响，优化了低温脉动热管设计。在理论和实验基础上，深入探索了低温脉动热管运行机理，分析驱动力、重力、毛细滞后阻力、汽塞及液塞运动等在低温脉动热管运行中的作用，和参数对其的影响机制。