Improved design tools for thermosyphon based thermal management systems

该项目的总体目标是与加拿大默森公司合作，为基于热虹吸的热管理系统开发工程设计 ** 工具。热虹吸管是被动的两相热传输装置;在加热区域蒸发工作流体并在冷却区域冷凝它，以非常小的热阻传递热量。Mersen Canada设计和开发热管理系统 **，该系统将热虹吸管用于高功率电气系统。该系统通常由散热器组成，散热器与热源（电气系统）相连，热虹吸管将热量从散热器传递到冷凝器端，热交换器将热量从冷凝器端排出到周围环境。任何新的热管理系统设计中的一个挑战 ** 是在给定的操作条件下表征和预测 ** 热虹吸管的性能。另一个重要的考虑因素是了解导致热虹吸管失效的因素。目前设计方法的一个主要缺点是缺乏可靠的工程模型，特别是对于默森目前在其热管理系统中使用的热虹吸管类型。这是进一步加剧，因为许多默森的应用是在高 ** 热通量和/或在极端的环境条件下。在这个项目中，将开发Mersen使用的 ** 热虹吸管类型的机械模型。将进行实验以表征热虹吸管的性能并验证模型。此外，还将开发提高散热器性能的方法，以减少由于电气系统局部发热而产生的热点效应。将开发计算模型来模拟热管理系统的冷凝器上使用的 ** 大型自然对流换热器的传热特性。

The overall objective of this project, in collaboration with Mersen Canada, is to develop engineering design**tools for thermosyphon based thermal management systems. Thermosyphons are passive two phase heat**transport devices; evaporating a working fluid in heated regions and condensing it in cooled regions, to transfer**heat with very small thermal resistance. Mersen Canada designs and develops thermal management systems**that use thermosyphons for high power electrical systems. The systems typically consist of heat spreaders that**are attached to the heat source (electrical system), thermosyphons that transfer the heat from the spreader to the**condenser end and a heat exchanger that rejects the heat from the condenser end to the ambient. One challenge**in any new thermal management system design is characterizing and predicting the performance of the**thermosyphons under the given operating conditions. Another important consideration is understanding the**factors that cause failure of the thermosyphons. A major drawback in the current design methodologies is the**lack of reliable engineering models, especially for the types of thermosyphons that Mersen currently uses in**their thermal management systems. This is further exacerbated since many of Mersen's applications are at high**heat flux and/or under extreme environmental conditions. In this project, mechanistic models for the types of**thermosyphons that Mersen uses will be developed. Experiments will be performed to characterize the**performance of the thermosyphons and validate the models. In addition, methods will be developed to improve**the performance of the heat spreaders to reduce the effect of hot spots due to local heat generation from the**electrical systems. Computational models will be developed to simulate the heat transfer characteristics of the**large scale natural convection heat exchangers used on the condenser of the thermal management systems.