Natural Convection in Microencapsulated PCM Slurries

采用微胶囊化相变浆料的中性浮力悬浮液，对水平和垂直受热表面的自然对流传热进行了一系列实验研究。目标是(1)验证理论预测的一个数量级的提高传热效率在单相系统；(2)建立预测不同浆料浓度下传热的相关性；(3)定义不同箱体内的流场和温度场，以验证未来详细的理论模型。随着小型化技术的发展，电子器件的热管理变得越来越重要。通过自然对流进行被动冷却具有简单可靠的优点，但传统工质产生的传热系数不足以处理非常高的热通量。本研究旨在通过在流体中加入含有相变材料的中性浮力微球，大大提高储热能力，从而大大扩展自然对流的上限。

A set of experiments will be carried out to study natural convection heat transfer over horizontal and vertical heated surfaces using neutrally buoyant suspensions of microencapsulated phase change slurries. The objectives are (1) to verify theoretical predictions of an order-of-magnitude enhancement of heat transfer effectiveness over single phase systems; (2) to develop correlations to predict heat transfer for different slurry concentrations; and (3) to define the flow and temperature fields in various enclosures for validation of future detailed theoretical models. Thermal management of electronic devices becomes more important as miniaturization technology advances. Passive cooling through natural convection has the advantage of simplicity and reliability, but the heat transfer coefficients resulting from traditional working fluids are insufficient to handle the very high heat fluxes. This research aims to significantly extend the upper limit on natural convection by adding neutrally buoyant microspheres containing a phase change material to the fluid, greatly increasing the capacity to store heat.