【作者】 史光；

【导师】 刘伟；

【作者基本信息】 华中科技大学 ， 工程热物理， 2007， 硕士

【摘要】 毛细抽吸两相循环系统是一种利用工质相变传输热量,由毛细力驱动系统循环的装置。作为一种热控系统,毛细抽吸两相回路因具有高效、可靠、节能等优点,愈来愈多地被应用到航天飞行器热控、高热流密度电子设备的冷却等诸多领域。系统以蒸发器多孔芯中液相与汽相间形成的弯月面所提供的毛细压头作为驱动力,驱动系统循环。通过工质的相变,系统在小温差下实现较大的热负荷传输。国内外的研究表明,由于各种原因,传统的毛细抽吸两相循环系统存在启动困难和运行过程中压力和温度的波动等问题,这严重制约其应用发展。国内外许多学者就此问题开展了广泛而深入的研究,积极探索解决的方法。本文首先介绍了毛细抽吸两相循环系统的工作原理和运行特点,对国内外毛细抽吸两相循环系统的研究状况进行了评述,指出了已有系统存在的缺点和不足。针对这些问题,结合国内外的研究经验,在本实验室设计并制造的新型平板式毛细泵循环(Capillary Pumped Loop)系统上进行了启动及变工况等大量的相关实验。实验证明,该系统具有良好的启动性能,稳定的变工况运行性能,为今后的进一步研究奠定了良好的基础。为了符合热负荷不断向高热流密度发展的趋势,本文初步设计了具有圆盘式蒸发器的小型环路热管(Loop Heat Pipe)系统,以期能够解决具有10W/cm2以上高热流密度热负荷的散热需求。本文针对所设计的小型圆盘式蒸发器,利用ANSYS仿真软件对其进行了强度分析,结果显示其应力、应变均符合设计要求;利用FLUENT仿真软件对其进行了启动前的瞬态热分析,模拟出启动前蒸发器内部的温度分布,这对以后的实验工作有重要的指导意义。最后,本文针对现有的CPL系统提出了改进措施,并对以后搭建LHP系统实验平台和进行相关的实验工作进行了展望。更多还原

【Abstract】 The Capillary Pumped Loop is such a system, of which the driven potential depends on the phase change of the working fluid and the capillary force. With high efficiency, high dependability, and energy saving, as a two-phase thermal-control system, it is applied in many fields such as controlling heat transfer on spacecrafts, cooling electronic devices with high power density. The system drives the working-media circulation by the capillary pressure across the surface tension formed at the liquid-vapor interface, transferring the great heat loads with low temperature difference by phase change.However, many investigations about the system indicate that there are problems that plague the application of it, such as being difficult to start-up and being unsteady when pressure oscillated during operation. Therefore, how to restrain the hydrodynamic oscillation and improve the start-up ability is the crucial issue on the system research. Many researchers are now investigating these problems.This thesis introduced the operation principles and characteristics of the Capillary Pumped Loop system, and gave some comments on the systems that had already been made. Based on their experience and what we had learned, we designed a new type CPL with flat evaporator. In order to better understand and analyze its operation theory and working performance, we had done lots of experiments on the new type system about the start-up and unsteady operation capabilities. The results indicated that the new type system had great start-up ability and steady working performance.In order to accord with the trend of electronic devices having higher and higher power density, we designed a new type miniature LHP system with disk evaporator, hoping to resolve the heat dissipation problems when the power density is above 10W/cm2. The structure of the disk evaporator was introduced in this article. The simulations for strength analysis were taken with 3-D model created using ANSYS, the results indicated that both the strain and the stress were under control. Also the simulations for transient thermal analysis before the evaporator start-up were taken; the results show the temperature distributions in the evaporator at different time. The studies were meaningful and helpful for the experimental research in the future.更多还原