一种两管径式脉动热管的流动与传热特性

为提高脉动热管的传热特性,提出了一种两管径式脉动热管结构,并基于质量、动量和能量守恒方程发展了适用的物理和数学模型。这种两管径式脉动热管对蒸发段和冷凝段取不同管径,两者的比值定义为直径比,应用上述理论模型分析了直径比对脉动热管运动规律和传热特性的影响。结果显示:采用两管径结构,可以有效提升脉动热管的自激振荡机制,特别是直径比小于1时的情况。而从传热特性而言,相比于传统等管径式脉动热管(直径比等于1),采用直径比小于1的结构可以使脉动热管的热阻明显减小,采用直径比大于1的结构却反而使传热特性下降。

Flow and heat transfer characteristics of a two-diameter pulsating heat pipe

In order to improve the heat transfer characteristics of pulsating heat pipes, a type of two-diameter pulsating heat pipe structure was proposed, and the applicable physical and mathematical model was developed based on the mass, momentum, and energy conservation equations. This two-diameter pulsating heat pipe adopted different pipe diameters between the evaporation section and the condensation section. The ratio of the two was defined as the diameter ratio. The above theoretical model was used to analyze the effect of the diameter ratio on the pulsating heat pipe motion and heat transfer characteristics. Results show that the two-diameter structure can effectively improve the self-excited oscillation mechanism of the pulsating heat pipe, especially when diameter ratio is less than 1. In terms of heat transfer characteristics, compared with the traditional equal-diameter pulsating heat pipe (diameter ratio equals to 1), using the structure of diameter ratio less than 1 can significantly reduce the thermal resistance of the pulsating heat pipe, but using the structure of diameter ratio more than 1 instead can decrease the heat transfer characteristics.