Session: 04-04: Nano/Microscale Boiling and Condensation Heat Transfer

Paper Number: 132004

132004 - Enhancing Pool Boiling Heat Transfer Performance With Composite Multiscale Bionic Structures Fabricated by Additive Manufacturing 

Abstract: 

In this study, three types of triply periodic minimal surface structures (Gyroid, Primitive, and Diamond structures) with distinct geometric characteristics were fabricated using additive manufacturing technology, showcasing significant biomimetic features and complex geometries. Porous structures were prepared on aluminum alloy base frames by finely controlling the process parameters during additive manufacturing, complemented by micro-pores formed by semi-melted powder. These characteristics collectively formed multiscale composite bionic structures, providing an ideal platform to explore their applications in heat exchange. Saturated pool boiling experiments were conducted using deionized water for gyroid, primitive and diamond structures. A high-speed camera was used to capture the nucleation, growth, and detachment of bubbles, enabling comprehensive evaluation of the thermal exchange performance of each structure. The experimental results revealed that compared to smooth copper surfaces, the three TPMS structures significantly impacted the enhancement of pool boiling heat transfer. Specifically, TPMS structures increased the heat exchange area and promoted bubble nucleation and rapid detachment, effectively enhancing the critical heat flux (CHF). The gyroid structure, due to its unique continuous surface properties, exhibited the highest critical heat flux. Moreover, the skeleton pores and surface micro-pores respectively increased critical heat flux and heat transfer coefficient (HTC) of the original gyroid structure. The dual effect of the skeleton pores and surface micro-pores effectively increased the surface area, not only promoting bubble nucleation but also accelerating bubble detachment and heat transfer. Additionally, the gyroid structure facilitated the formation of a more stable vapor layer and promoted more effective vapor-liquid interaction. Although primitive and diamond structures also exhibited higher heat transfer performance due to their porous structures and surface micro-pores, they were still inferior to the gyroid structure. Further, a detailed analysis of the bubble motion dynamics in these structures was conducted. Processing of high-speed camera footage revealed significant differences in bubble behavior across different structures, including variations in size, growth rate, and movement and detachment patterns on various surface structures. These observations provide crucial perspectives for understanding and optimizing the boiling heat exchange process. In summary, this study successfully demonstrates the fabrication of biomimetic structures and their application in boiling heat exchange. These findings not only offer important practical foundations for the application of additive manufacturing technology in designing efficient heat exchangers but also provide valuable data support for the design and optimization of more efficient heat exchange systems in the future. Through this research, the application scope of triply periodic minimal surface structures is expanded, and new possibilities are presented for the use of additive manufacturing technology in complex thermal management systems.

Presenting Author: Li Zhang East China University of Science and Technology

Presenting Author Biography: Design and controllable fabrication methods for reinforced phase change heat transfer surfaces with micro and nano hierarchical structures; structural optimization design to enhance critical heat flux (CHF) for cooling high heat flux components, integrated with 3D printing technology. Research and development of efficient cooling technologies for nuclear power equipment and high heat flux chip cooling.

Authors:

Zhonghao Gu East China University of Science and Technology
Kang Yang East China University of Science and Technology
Li Zhang East China University of Science and Technology