【作者】 王立新；

【导师】 孙志坚； 洪荣华；

【作者基本信息】 浙江大学 ， 工程热物理， 2006， 硕士

【摘要】 为解决高热流密度电子元件的散热要求，确保其工作在正常的温度范围内，电子元件散热器的研究日益受到重视，传统单相流散热器不能满足日益增大的热流密度要求。回路型重力热管不使用毛细结构，结构简单、加工方便，依靠重力自然回流，相变传递热量，是解决高热流密度电子元件散热的有效途径之一。 回路型热管蒸发腔内的换热流动是一个复杂的非线形两相流过程，利用Fluent中多相流模型Mixture Model，并结合实际模型编写Udf程序，使状态方程、边界条件和物性参数和数学模型结合起来求解。叙述了这些确定条件在Flunet软件中的实现方法，以及在软件使用过程中应注意的一些问题和具体的操作方法，为用Fluent软件模拟传热运动过程做充分的准备。为验证计算方法的可靠性，计算结果与实验结果进行了对比，二者温度变化的规律是一致的，误差相差2～3℃，计算模型和结果是有意义的。 用Fluent数值模拟分析了回路型热管蒸发器的换热特性。首先，计算了不同发热功率(100W～140W)，不同饱和温度(40℃～70℃)，不同充液量(6mm～11mm)对蒸发器底板的温度场分布的影响，进而得到发热电子元件表面的最高和最低温度；其次，分析了不同形状强化槽道表面(矩形、半园形和三角形)对蒸发器底板温度分布的影响；此外，还计算了发热功率为100W，饱和温度为50℃，充液量为6mm，初始温度为20℃时，蒸发腔内瞬态的传热过程，得到了不同时刻瞬态的温度场图，显示了热管从启动到稳定过程中的温度变化；最后利用BP网络模型对计算数据做了处理，利用线形回归整理出了参数关联式，扩展了计算结果的应用范围。 结果表明，回路型重力热管能有效解决高热流电子元件的散热要求，使其工作在临界温度以下，计算方法和结果为蒸发器的优化设计提供了理论支持。更多还原

【Abstract】 The research of radiator for electronic cooling is regarded more and more because of its meeting demand for electronic component with high heating flux and ensuring its working within normal temperature range. However, the traditional single-phase radiator can not meet the demand of higher and higher heating flux. No capillary Loop thermosyphon machined easily and circulated by its own gravity is one of the most effective way to solve heating dissipation of electronic component with high flux via phase change heat transfer.It is a complicated nonliner two-phase liquid process in the evaporator. The problem can be solved by using the Mixture Model of Fluent software and programing UDF to make the state equation,boundary condition,physical parameter and math model combine. Morever, how to make these setting in the Fuent software is discussed in detail. The temperature results by computing and experimental means are compared to get that the temperature difference between them is 2-3 ℃, but the temperature changing tendency between them are alike,and the computing model and results can be accepted.The performance of evaporator of loop thermosyhon is simulated numerically and analyzed by fluent software. The parameter of heating power(l00W-140W), saturation temperature (40℃-70℃ ) height of water quantity (6mm-11mm) and different shape augmented surface is computed and the temperature field is achieved. The situation of temperature on electronic component surface is also achieved. Furthermore,The transient heating procedure in the evaporator is computed and the transient temperature fields are achieved. The computational data is dealed by using the BP net and parameter formula is gained by using liner regression.The result shows that the loop thermosyphon can meet the demand for heating dissipation of high fulx electronic component and can make it work under the critical temperature. The computing results and procedures provides theoretic help to the optimum design of evaporator.更多还原