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.

该提案是爱丁堡大学、布鲁内尔大学和伦敦玛丽女王大学的国际领先的英国传热研究小组与四个工业合作伙伴（Thermacore、Oxford Nanosystems、Super Radiator Coils 和 Rainford Precision）合作的一个联合项目。微制造和热管理领域。制造工艺的进步以及随后在更高功率密度下运行的小型电子设备的使用导致了对热管理系统提供密集局部冷却的迫切需求。为了防止电子元件发生故障，必须仔细控制任何电子设备所有部件的工作温度。这可能导致整个设备的平均排热率要求至少为 2 MW/m2，局部“热点”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，液体冷却系统只能达到 0.7 MW/m2。其他技术尚未实现超过 1 MW/m2 的热通量。微通道中的沸腾提供了在均匀表面温度下实现如此高热通量的最佳前景。在封闭系统中，需要同样紧凑且有效的冷凝器来向环境排热。在高热通量下，蒸发器干燥会带来严重的问题，导致表面局部过热，从而可能烧毁依赖于蒸发冷却的电子元件。使用被称为“自再润湿流体”的新型混合物，其表面张力特性有助于改善热表面的润湿性，可能为增强冷却技术提供空间。在该项目中，两种不同的酒精水溶液（其中一种是自再润湿液体）将研究它们是否能够提供超过 2 MW/m2 的闭环冷却系统所需的必要蒸发和冷凝特性。爱丁堡大学的研究人员将研究其基本原理使用先进的成像技术，对混合物的润湿和蒸发/冷凝进行分析，以确定蒸发和冷凝的最佳混合物浓度和传热表面涂层。伦敦布鲁内尔大学将研究流体在金属单微通道和多微通道蒸发器中的应用。伦敦玛丽女王大学的研究人员将对紧凑型交换器中混合物的冷凝进行实验和理论工作。综合结果将用于完整微型闭环蒸发冷却系统的设计。Thermacore 将提供微型热交换器，Oxford Nanosystems 将提供结构化表面涂层。可持续发动机系统、超级散热器线圈将提供建议并代表将本研究的开发成果推向市场的其他方法。 Rainford Precision 将向布鲁内尔大学提供微型工具并支持其在微机械加工中的使用。