Enhancing heat pipe performance through hybrid wick structures: Balancing pore size and permeability

Abstract

This study investigates the impact of wick structures on heat pipe performance by optimizing the balance between effective pore radius and permeability for efficient heat dissipation. It addresses the challenge of enhancing capillary pumping forces while maintaining optimal liquid replenishment to the evaporator. A novel hybrid wick structure is proposed, strategically integrating sintered and screened elements within the heat pipe to improve thermal performance. Experimental tests include varying inclination angles (antigravity up to 60°) to assess thermal resistance and liquid return capabilities. Results show a 13.31 % reduction in thermal resistance compared to conventional sintered heat pipes, particularly at higher power levels (40 W– 60 W). At a 40° inclination angle, optimal evaporation and liquid flow improve thermal performance, with thermal resistance for sintered and hybrid heat pipes decreasing by 14.05 % and 27.72 %, respectively. However, at 60° inclination, the hybrid’s thermal resistance increases significantly due to local dry-out. The study identifies limitations beyond 45° inclination, which is attributed to increased receding contact angles, and the influence of gravity becomes more pronounced, affecting capillary limits. This research underscores the importance of innovative wick designs in advancing heat pipe technology for diverse applications.