A closed-loop pulsating heat pipe within atmospheric temperature relies on the pulsation and phase change of the internal working fluid. It has been widely used for the heat dissipation of electronic components owing to its high heat transfer efficiency

simple structure

and low cost. In this study

the factors affecting the startup and heat transfer performance of pulsating heat pipes are divided into three categories

namely

structural parameters

operating conditions

and working fluid properties. First

the structural parameters

including factors such as diameter

cross-sectional shape

number of U-bends

and length ratio of each section

are summarized. Second

the influence of operating conditions

including the heating power

inclination angle

and liquid filling rate

is analyzed. Finally

the physical parameters of the working fluid are divided into flow and heat transfer properties. To improve the start-up and heat transfer performance of pulsating heat pipes

future research should focus on conducting in-depth investigations into the critical number of U-bends. The anti-gravity performance of heat pipes must be improved for adapting to small inclination angles and negative angle conditions. A comprehensive evaluation criterion describing the influence of physical parameters on performance should also be established.