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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皇后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、牛津纳米系统、超级散热器线圈和雷恩福德精密）在微制造和热管理领域合作的联合项目。制造工艺的进步和随后使用以增加的功率密度操作的较小规模电子设备已经导致对热管理系统的关键需求，以提供密集的局部冷却。为了防止电子元件故障，必须仔细控制任何电子设备的所有部件的工作温度。这可能导致整个装置的平均除热率要求至少为2 MW/m2，局部“热点”处的峰值率高达10-15 MW/m2。直接空气冷却限于约0.5 MW/m2，液体冷却系统仅能达到0.7 MW/m2。其他技术还没有达到1 MW/m2以上的热通量。微通道内的沸腾提供了最好的前景，实现这样高的热通量与均匀的表面温度。在封闭系统中，需要同样紧凑和有效的冷凝器来将热量排出到环境中。在高热通量下，蒸发器变干会造成严重的问题，导致表面局部过热，从而可能烧坏依赖于这种蒸发冷却的电子部件。使用新型混合物，称为“自再润湿流体”，其表面张力特性有助于改善热表面上的润湿性，可能为增强冷却技术提供范围。两种不同的醇水溶液（其中一种是自回湿），以确定它们是否能提供封闭式-爱丁堡大学的研究人员将研究混合物的润湿和蒸发/冷凝的基本原理，以建立最佳的混合物浓度和传热表面涂层，用于蒸发和冷凝，使用先进的成像技术。在布鲁内尔大学伦敦，应用的流体在金属单和多微通道蒸发器将进行调查。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研究。综合结果将用于设计完整的微尺度闭环蒸发冷却系统。Thermacore将提供微尺度热交换器，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，并将提供建议，并代表将这项研究的发展推向市场的其他方式。雷恩福德精密将提供布鲁内尔大学的微型工具和支持，他们在微加工的使用。