3D pulsating heat pipes and phase change materials (PCMs) can be used for energy-efficient data centers. In this study an experimental bench of a 3D pulsating heat pipe/PCM module was built to study the heat transfer and energy saving characteristics of the coupled system. The 3D pulsating heat pipe with two liquid-filling rates of 34% and 44% was studied using three working materials

methanol

ethanol

and acetone. The thermal resistance model of the coupling module was established

and the thermal resistance variation rate of the coupling module was defined. The thermal resistance variation and energy-saving characteristics of the coupling module were studied under conditions of variable air temperature (20–26 °C) and velocity (3–9 m/s). In addition

the thermal resistance and energy-saving characteristics of the coupling module were studied. The results show that the thermal resistance change rate of the coupling module with 34% liquid filling rate is higher than that of the liquid filling rate of 44%

in which the thermal resistance change rates using methanol at 80 W and 120 W heating power are 48.2% and 48.7%

respectively. These are higher than those using ethanol and acetone under the same conditions. Compared with the traditional cooling method of data centers

the fans and chips can save 143.61 kWh and 176.82 kWh per year under 80 W heating power

respectively.