权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

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Rainford Precision)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以更高功率密度运行的较小规模电子设备的使用导致了对热管理系统的迫切需求，以提供密集的局部冷却。为了防止电子元件发生故障，任何电子设备的所有部件的工作温度都必须仔细控制。这可能导致整个设备的平均散热速率要求至少为2 mW/m2，在局部“热点”处的峰值散热速率高达10-15 mW/m2。直接空冷限制在0.5兆瓦/平方米左右，液体冷却系统只能达到0.7兆瓦/平方米。其他技术还没有达到1 mW/m2以上的热流密度。微通道内的沸腾是获得如此高的热流密度和均匀表面温度的最好前景。在封闭系统中，需要一个同样紧凑和有效的冷凝器来将热排出到环境中。在高热流密度下，蒸发器干涸是一个严重的问题，导致表面局部过热，因此有可能烧坏依赖这种蒸发冷却的电子元件。新型混合物的使用，被称为“自增湿流体”，其表面张力特性有助于改善热表面的润湿，潜在地提供了增强冷却技术的空间。在该项目中，将研究两种不同的酒精水溶液(其中一种是自增湿)，以确定它们是否能够提供所需的蒸发和冷凝特性，以满足2兆瓦/平方米以上的闭环系统所需。爱丁堡大学的研究人员将利用先进的成像技术，研究混合物的润湿和蒸发/冷凝的基本原理，以确定蒸发和冷凝的最佳混合物浓度和热传递表面涂层。在伦敦布鲁内尔大学，将研究这种流体在金属单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换热器中混合物的冷凝进行实验和理论研究。合并后的结果将用于设计一个完整的微型闭环式蒸发冷却系统。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。可持续发动机系统，超级散热器线圈，将提供建议，并代表将这项研究的开发推向市场的其他方式。Rainford Precision将为布鲁内尔大学提供微型工具，并就其在微机械加工中的使用提供支持。