Study On Heat Transfer Process And Visualization Of Two-phase Closed Thermosyphon

With the rapid development of society and economy,the increasing demand of energy,resulted in environmental problems have become increasingly prominent,the recovery of waste heat recycling is more and more important for protect the environment.As one of the most efficient heat transfer components,heat pipe is widely used in industry.This paper briefly describes the development of the research on heat pipe and two-phase closed thermosyphon.At present,the majority of research on thermosyphon is experiment.With the development of the computer technology,the numerical calculation is applied to the engineering practice.In this paper,on the basis of previous theoretical and experimental research,established numerical model of thermosyphon,and simulated by loading UDF use Fluent software,the results obtained were good agreement with the experimental results.The influence of heat flux,work fluid and dip angle on the internal flow and heat transfer process of thermosyphon was discussed.The results show that the heat flux in the range of 1500~40000W/m2,ethanol is better than water,and copper-water heat pipe's heat transfer efficiency reached the highest at 35000 W/m2;at the same heat flux,changed the angle show that the copper-water heat pipe's heat transfer efficiency reached the highest at 55 degrees.Copper-ethanol heat pipe reached a maximum at 60 degrees,and the copper water heat pipe's starting time is shortest at 57 degrees.And the evaporation and condensation processes were analyzed in this paper.The visualization of the behavior of bubble nucleation,growth,detachment,and merge was obtained,and all behavior can analyzed by the classical thermodynamic theory.This study provide a reference for improving the heat transfer performance of two-phase closed thermosyphon.