In - Situ Construction Of Inorganic Nanotubes On Cu - Based Surface And Study On Heat Transfer Performance Of Drop - Like Condensation

Condensation phase change heat transfer is a ubiquitous phase-change process that is an essential natural phenomenon and widely used in various industries for applications including,chemical engineering, power generation, thermal management, desalination, and environmental control. Recently, Enhancing heat transfer during condensation has been a hot area of research.Compared with filmwise condensation, dropwise condensation is a type of more efficient heat transfer mode. Besides, the condensate microdrop self-propelling can provide a new way to design the structure for enhancing heat transfer. Based on this, we designed and fabricated a type of copper-based well-aligned tip-like zinc oxide（ZnO） nanotube arrays. Subsequently, after low-surface-energy fluorosilane modification, we found that the nanostructure can realize condensate microdrops self-propelling function. Dropwise condensation heat transfer performance of micro droplets were observed and quantitative measured. The study not only has important significance for understanding the relationship between structure and heat transfer properties, but also help developing advanced heat transfer interface nanomaterials and devices for high-efficiency energy utilization and thermal management.This article main research contents are as follows:（1） Dropwise condensation heat transfer performance study on copper-based ZnO nanotube arrays. A facile two-step chemical bath method and synergistic reaction mechanism were used for the in situ growth of ZnO nanotube arrays on copper substrates. Through modification of low surface energy material, these structure surfaces can realize coalescence and efficient self-propelling of condensation microdroplets. Researches show that the nanostructure samples can greatly improve the heat transfer performance: at 40°C steam temperature, compared to the smooth samples, the heat flux can improve more than 150%, the heat transfer coefficient improves 110 %.（2） Dropwise condensation heat transfer performance study on copper-based CeO₂/ZnO nanotube arrays with a rough mouth. The CeO₂/ZnO nanotube arrays were synthesized by an efficient and simple two-step chemical bath deposition, after low-surface-energy fluorosilane modification, the nanostructure can show excellent superhydrophobicity and low adhesive force.We further investigated the process and mechanism by single factor variable experiments.Researches show that the nanostructure samples can greatly improve the heat transfer performance: at 40°C steam temperature, compared to the smooth samples, the heat flux can improve about 132%, the heat transfer coefficient improves 288%.