Numerical investigation of phase change heat transfer in a confined micro-space by lattice Boltzmann method

Abstract

Phase-change heat transfer has attracted wide attention in thermal management of electronic infrastructures, such as the data center and 5G base station antenna. It possesses the characteristics of high equivalent thermal conductivity, rapid heat diffusion and good temperature uniformity. However, the existing thermal solution to advanced high-performance devices becomes more challenging with high heat flux and small heat dissipation area. Current surface modification technology has been applied for enhancing phase-change means in energy-related fields. In this paper, the hybrid lattice Boltzmann (LB) method was utilized to explore vapor-liquid phase-change mechanism and its enhancement in a confined micro-space. Different modified surfaces’ effects on bubble growth behavior and interfacial phase-change heat transfer were respectively discussed. Based on the pseudopotential LB approach and energy equation, the boiling and condensation regimes were quantitatively evaluated with the heat transfer coefficient and transient heat flux. The numerical results indicated that the wettability possessed significant impacts on the primary characteristics of phase-change heat transfer. It was found that hydrophilic contact angle promoted the initial boiling, while hydrophobic one helped to facilitate drop-wise condensation. The hybrid surfaces possess the best performance for the boiling heat transfer enhancement. Both the modified hybrid and wettability gradient surfaces have positive contributions to the condensation heat transfer enhancement. This study is expected to provide a reference for improving phase-change heat transfer technology for sustainable energy applications.