脉动热管单向运行性能研究

发布时间：2018-05-16 00:33

本文选题：脉动热管 + 可视化　；参考：《华南理工大学》2015年硕士论文

【摘要】：脉动热管是一种新型高效的热管,具有制造成本低和传热性能好的特点。随着各种热管理环境对散热要求的提高和脉动热管本身技术的发展,脉动热管具有十分广阔的应用前景。特别是制造出可稳定单向循环的脉动热管,将对脉动热管的性能有极大的提升,进一步拓宽了脉动热管的应用。本文主要研究脉动热管单向运行的条件及性能。基于非对称的思想,设计了半可视化的脉动热管观察单行流的发生,同时对其温度变化规律进行研究,然后对单向运行的脉动热管的启动性能和稳定运行性能进行研究,并发现脉动热管单向运行的外部条件是输入热流密度的不对称,并且在单侧加热的情况下可以获得最小热阻。重力决定单行运行的方向,即位于加热段的工质总有沿着重力反方向运动的趋势。在对脉动热管非对称加热的温度变化研究中,发现脉动热管运行时存在对立统一的震荡性和单向性。两侧输入的热流密度差异越大,单向性越强,振荡性越弱;反之,单向性越弱,振荡性越强。在对脉动热管单向运行性能的研究中,发现脉动热管的启动性能和稳定运行性能随着功率的增加而增加,但随着充液率的变化出现相反的变化。充液率越高,启动性能越好,稳定运行性能越差。因此,并不存在一个绝对最优的充液率使脉动热管的性能达到最佳,而是需要根据实际应用环境进行取舍。本文还发现对于单向运行的脉动热管,在高功率低充液率条件下,相变传热占主导。同时,本文还发现了重力使更多的液态工质聚集在底部,加热段位置越高,局部充液率就越低,则启动性能越差,稳定运行性能也越差,从而为脉动热管的反重力应用提供指导。
[Abstract]:Pulsating heat pipe is a new type of heat pipe with low manufacturing cost and good heat transfer performance. With the improvement of heat dissipation requirements in various thermal management environments and the development of pulsating heat pipe technology, pulsating heat pipe has a very broad application prospect. Especially the pulsating heat pipe with stable unidirectional circulation will greatly improve the performance of the pulsating heat pipe and further expand the application of the pulsating heat pipe. This paper mainly studies the condition and performance of pulsating heat pipe in one-way operation. Based on the idea of asymmetry, a semi-visual pulsating heat pipe is designed to observe the occurrence of single flow, and the law of temperature variation is studied. Then, the start-up performance and stable operation performance of unidirectional pulsating heat pipe are studied. It is also found that the external condition of unidirectional operation of pulsating heat pipe is the asymmetry of input heat flux, and the minimum thermal resistance can be obtained under the condition of unilateral heating. Gravity determines the direction of one-line operation, that is, the working fluid in the heating section always moves in the opposite direction of gravity. In the study of the temperature variation of pulsating heat pipe asymmetric heating, it is found that there is a unified opposites and unidirectional characteristics in the operation of pulsating heat pipe. The greater the difference of heat flux between two sides is, the stronger the unidirectional property is and the weaker the oscillation is, whereas the weaker the unidirectional property is, the stronger the oscillation is. In the study of the unidirectional operation performance of pulsating heat pipe, it is found that the start-up performance and stable operation performance of pulsating heat pipe increase with the increase of power, but the change of liquid filling rate is opposite. The higher the liquid filling rate, the better the startup performance and the worse the stable operation performance. Therefore, there is no absolute optimal liquid filling rate to optimize the performance of the pulsating heat pipe, but it is necessary to choose and choose according to the practical application environment. It is also found that for unidirectional pulsating heat pipe, phase change heat transfer is dominant under the condition of high power and low liquid charge rate. At the same time, it is also found that gravity makes more liquid working fluids gather at the bottom, the higher the position of the heating section, the lower the local filling rate, the worse the startup performance and the worse the stable operation performance. It provides guidance for the anti-gravity application of pulsating heat pipe.
【学位授予单位】：华南理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TK172.4

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