In order to study the heat transfer mechanism of two-phase closed thermosyphon

the physical model of two-phase closed thermosyphon was established and calculated by numerical analysis. The effects of heat flux

dip angle and working fluid on the heat transfer performance of two-phase closed thermosyphon were studied

and the evaporation phase volume fraction cloud chart

the internal heat transfer coefficient curve and temperature field under different conditions were obtained.. The results show that

the heat transfer mechanism of the condensation is the phase change film condensation and the evaporation section is boiling heat transfer. The working fluid has a great influence on the performance of the thermosyphon

and the optimal heat transfer performance exists in the heat pipes. Moreover

the main mechanism for each factor affecting the heat transfer efficiency is the behavior of the bubbles.