Flow Boiling and Condensation of Mixtures in Microscale

微尺度混合物的流动沸腾和冷凝

基本信息

批准号：
EP/N011112/1
负责人：
Tassos Karayiannis
金额：
$ 55.01万
依托单位：
Brunel University London
依托单位国家：
英国
项目类别：
Research Grant
财政年份：
2016
资助国家：
英国
起止时间：
2016 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=EP%2FN011112%2F1
关键词：
Flow Boiling Condensation Mixtures Microscale

项目摘要

This proposal is for a joint project between internationally-leading, UK heat transfer research groups at the Universities of Edinburgh, Brunel and Queen Mary, London in collaboration with four industrial partners (Thermacore, Oxford Nanosystems, Super Radiator Coils and Rainford Precision) in the areas of micro-fabrication and thermal management. Advances in manufacturing processes and subsequent use of smaller scale electronic devices operating at increased power densities have resulted in a critical demand for thermal management systems to provide intensive localised cooling. To prevent failure of electronic components, the temperature at which all parts of any electronic device operates must be carefully controlled. This can lead to heat removal rate requirements averaging at least 2 MW/m2 across the complete device, with peak rates of up to 10-15 MW/m2 at local 'hot spots'. Direct air cooling is limited to about 0.5 MW/m2 and liquid cooling systems are only capable of 0.7 MW/m2. Other techniques have not yet achieved heat fluxes above 1 MW/m2.Boiling in microchannels offers the best prospect of achieving such high heat fluxes with uniform surface temperature. In a closed system an equally compact and effective condenser is required for heat rejection to the environment. At high heat flux, evaporator dry-out poses a serious problem, leading to localised overheating of the surface and hence potentially to burn out of electronic components reliant on this evaporative cooling. Use of novel mixtures, termed 'self-rewetting fluids', whose surface tension properties lend themselves to improved wetting on hot surfaces, potentially offers scope for enhanced cooling technologies.In this project, two different aqueous alcohol solutions (one of which is self-rewetting) will be studied to ascertain whether they can provide the necessary evaporative and condensation characteristics required for a closed-loop cooling system capable of more than 2 MW/m2.Researchers at the University of Edinburgh will study the fundamentals of wetting and evaporation/condensation of the mixtures to establish the optimum mixture concentrations and heat transfer surface coating for both evaporation and condensation, using advanced imaging techniques. At Brunel University London, applications of the fluids in metallic single and multi microchannel evaporators will be investigated. Researchers at Queen Mary University London will carry out experimental and theoretical work on condensation of the mixtures in compact exchangers. The combined results will feed into the design of a complete microscale closed-loop evaporative cooling system.Thermacore will provide micro-scale heat exchangers and Oxford Nanosystems will provide structured surface coatings. Sustainable Engine Systems, Super Radiator Coils and will provide advice and represent additional ways of taking developments originating from this research to the market. Rainford Precision will provide Brunel University micro tools and support on their use in micromachining.

该提议是针对爱丁堡大学，布鲁内尔和玛丽皇后，与四个工业合作伙伴（ThermaCore，牛津纳米系统，超级散热器线圈和Rainford精确的四个工业合作伙伴）合作的国际领先，英国传热研究小组之间的联合项目。制造过程的进步以及随后在增加功率密度运行的较小电子设备的使用，导致对热管理系统的关键需求，以提供密集的局部冷却。为了防止电子组件故障，必须仔细控制任何电子设备所有部分的温度。这可能会导致整个设备上至少平均至少2 mW/m2的排放速率要求，在局部“热点”处的峰值速率高达10-15 mW/m2。直接空气冷却仅限于约0.5 mW/m2，液体冷却系统仅能为0.7 mW/m2。其他技术尚未达到1兆瓦/m2的热通量。微通道的沸腾量提供了达到如此高的热通量均匀表面温度的最佳前景。在封闭的系统中，需要同样紧凑且有效的冷凝器才能对环境进行热排斥。在高热量通量下，蒸发器的干燥构成了一个严重的问题，导致表面局部过热，从而有可能燃烧出依赖于这种蒸发冷却的电子成分。使用新颖的混合物，称为“自弃液”，其表面张力的特性使自己可以改善在热表面上的润湿，并有可能为增强的冷却技术提供范围。在这个项目中，两种不同的水性酒精解决方案（其中一种是自我剥削），以确定是否可以确定是否需要确定的避孕功能，并且是否可以确定悬而未决的蒸发特征MW/M2。爱丁堡大学的研究者将研究混合物的润湿和蒸发/凝结的基础，以使用先进的成像技术建立最佳混合物浓度和蒸发和冷凝的最佳混合物浓度。在伦敦布鲁内尔大学，将研究流体在金属单一和多微通道蒸发器中的应用。伦敦玛丽皇后大学的研究人员将开展实验和理论工作，涉及紧凑型交易所中混合物的凝结。结合的结果将进一步介入完整的微观闭环蒸发冷却系统的设计。Thermacore将提供微型热交换器，牛津纳米系统将提供结构化的表面涂层。可持续的发动机系统，超级散热器线圈，并将提供建议，并代表从这项研究到市场的源自开发的其他方法。 Rainford Precision将提供Brunel University的微型工具，并支持其在微加工中的使用。