Opportunities in Nano-Engineered Surface Designs for Enhanced Condensation Heat and Mass Transfer

Abstract

Recent advancements in surface nano-engineering have spurred intense interests in their implementation for enhancing condensation heat transfer. When appropriately designed, nano-engineered surfaces not only lead to highly efficient transport mechanisms not achievable with conventional dropwise condensation (DWC), they also demonstrate the possibility of augmenting condensation of low surface tension fluids widely used in industry. These advantages are further enhanced by the development of highly scalable nanofabrication methods, which enable the potential transition from laboratory-scale prototypes to real-world industrial applications. In this review, we discuss the progress, opportunities, and challenges of enhancing condensation heat and mass transfer with nano-engineered surfaces. This article provides an overview of the recent developments in micro/nanoscale coating and structure fabrication techniques and performs a thorough comparison of their condensation performance, elucidating the complex interfacial transport mechanism involved. Surface structuring methods that are durable, scalable, and low-cost are essential attributes for large-scale industrial implementation. Here, the methods used to improve surface durability and demonstrations of nanostructure-enhanced meter-scale condensers are presented. Limitations are discussed and the potential techniques to overcome these challenges are summarized. Given the recent development of metal additive manufacturing (AM) technology and its growing relevance in manufacturing processes, we end this review by providing our perspectives on the opportunities in enabling surface nanostructuring of metal additive manufactured materials and the potential of nanometric–millimetric codesign optimization for the development of next-generation additively manufactured condensers.