Ultra high boiling performance on nano/microstructured surfaces through electrodeposition of copper and graphene

基于脉冲电沉积石墨烯/碳纳米管及其铜复合材料的超高池沸性能研究努力获得一个基本的理解沸腾机制在增强的微结构表面与纳米涂层在首选位置。采用先进的可视化和测量技术，采用高速成像（高达25,000 fps）和5 - 13 μ m尺寸的微热电偶，将开发和验证一个新的模型，该模型结合了微对流在增强沸腾传热中的作用。该模型将通过COMSOL Multiphysics®数值模拟和单独设计的微观结构特征池沸腾实验进一步验证，并在优选区域应用纳米涂层。通过局部气泡/液体运动和相关传热获得的基本见解将为加强和模拟池沸腾传热和临界热流密度（CHF）提供新的途径。电化学领域的一些最新进展将被用于开发高导电性的多孔石墨烯基结构，这些结构可以为传热和CHF增强提供可控的形态特征。池沸腾是一种极其重要的传热方式，应用于许多关键技术，包括发电（核能、化石燃料和替代能源）、电子冷却、石化和加工工业，以及空调和制冷应用。在沸腾过程中，传热性能的改进通常旨在：(i)减少壁面过热度，（ii）增加最大传热速率，即临界热通量。拟议的项目提供了解决这两个性能改进参数的新途径。本项目提出的新方法和建模将为提高利用沸腾过程的设备的能源效率提供新的途径。这对于利用替代热能尤其具有重要意义，因为可用的温差通常很低，而且至关重要。

CBET 1335927PI: Kandlikar The proposed project Ultra High Pool Boiling Performance on Novel Microstructures through Pulsed Electrodeposition of Graphene/Carbon Nanotubes and their Copper Composites? strives to gain a fundamental understanding of the boiling mechanism over enhanced microstructured surfaces with nanocoatings at preferred locations. A new model that incorporates the role of microconvection in enhancing the boiling heat transfer will be developed and validated by using advanced visualization and measurement techniques employing high speed imaging (up to 25,000 fps), and microthermocouples of 5 - 13 µm dimensions. The model will be further validated through COMSOL Multiphysics® numerical simulation and pool boiling experiments over individually designed microsctruture features with nanocoatings applied over preferred regions. The fundamental insight gained through the localized bubble/liquid motion and the associated heat transfer will provide new avenues in enhancing and modeling the pool boiling heat transfer and critical heat flux (CHF). Some of the recent advances in the field of electrochemistry will be utilized in developing multi-porous graphene-based structures that are highly conductive and can provide controlled morphological features for heat transfer and CHF enhancement.The pool boiling constitutes an extremely important mode of heat transfer that is applied in a number of critical technologies including power generation (nuclear, fossil fuel, and alternative energy source based), electronics cooling, petrochemical and process industries, and air-conditioning and refrigeration applications. Heat transfer performance improvements in the boiling process are generally aimed at: (i) a reduction in the wall superheat, and (ii) an increase in the maximum heat transfer rate, identified as the critical heat flux. The proposed project provides a new pathway to address both of these performance improvement parameters. The new approach and the modeling proposed in this project will provide a new pathway in improving energy efficiencies of devices utilizing the boiling process. This is in particular of great significance for utilizing alternative thermal energy sources, since the available temperature differences are generally low and are of critical importance.