Research on the thermal performance and stability of three-dimensional array pulsating heat pipe for active/passive coupled thermal management application

•A novel planar-structured three-dimensional array pulsating heat pipe was designed.•The planar structure reduces the contact thermal resistance of the heat source.•Array structure promotes temperature uniformity of the 3D-APHP.•3D-APHP has excellent thermal conductivity under different working conditions. The efficient heat transfer performance of three-dimensional pulsating heat pipes can effectively deal with the heat dissipation problems in the field of electronics integration. However, the large contact thermal resistance and complex layout limit the actual cooling efficiency. In this study, a novel three-dimensional array pulsating heat pipe (3D-APHP) with a dual-plane structure was designed. The top and bottom of the 3D-APHP are mounted with flat plates, and the center section is connected by multiple parallel array tubes. The planar and array structures enhance the flexibility in the actual layout of the pulsating heat pipe to accommodate space constraints. The effects of different conditions (working fluid, filling rate, heating power, tube diameter and installation condition) on the heat transfer performance and uniform temperature performance of 3D-APHP were investigated. It is found that 3D-APHP demonstrates efficient heat transfer capability and temperature uniformity. The minimum thermal resistance and maximum thermal conductivity can reach 0.059 °C/W and 170.1 KW/m °C, respectively. Moreover, 3D-APHP exhibits good heat transfer performance across different installation positions with a maximum thermal resistance not exceeding 1.1 °C/W, revealing significant potential for applications. Meanwhile, the two-phase heat transfer process inside the 3D-APHP was analyzed. The uniform vapor–liquid plug distribution can significantly strengthen the thermal performance of the 3D-APHP.