Thermal characterization and wick optimization of mini-grooved flat heat pipe for electronics cooling.

Effective cooling technology is intensely demanded to cool the electronic devices within small space under high heat flux. Mini-grooved flat heat pipe (FHP) with simple structure, close contact with heat source, uniform temperature and high thermal conductivity can satisfy the demand of transferring the great heat rapidly and weakening the hot spot of electronic devices. As fine wick feature and distribution played a critical part in improving the performance of mini-grooved FHP, a thermal experiment was established to explore the heat transfer characterization of mini-grooved FHP with different wick structures and distributions. And a mathematical model in one dimension was set up to investigate the fluid flow and heat transmission performance of FHP with V-type or rectangle-type grooves, expecting to assist the experiment in understanding the operating mechanisms of mini-grooved FHP further. Effects of input heat, inclined angle, working temperature and wick structure were examined. It is found that among the V-type, rectangle-type and block-type mini-grooved FHPs, V-type FHP presents better heat transfer rate, while block-type FHP displays larger maximum heat transfer amount. V2 sloped convex gradient mini-grooved FHP owns the optimum overall performance. It possesses the merits of narrower grooves at the evaporation section, wider grooves at the condensation section and larger vapor chamber space, which can optimize the liquid and vapor circulation processes inside the FHP. Its thermal resistance and maximum temperature reduce by almost 9.7% and 3.4% separately in comparison with those of V1 straight mini-grooved FHP, which is beneficial to guarantee the reliability and stability of electronic devices. [ABSTRACT FROM AUTHOR]