Performance enhancement of disk-shaped flat loop heat pipe

This study addresses the challenge of effective heat dissipation in electronic systems, a critical issue as increased thermal loads demand improved thermal management to ensure reliable performance and longevity. We investigated the performance of disk-shaped flat loop heat pipes by comparing copper and nickel wick materials, using a 6% butanol aqueous self-rewetting fluid as the working fluid. This fluid was chosen for its rapid evaporation characteristics, which help mitigate heat leakage by promoting phase change removal before excessive heat penetration, and for its surface tension reversal property that facilitates prompt fluid replenishment. Experimental results revealed that the copper wick configuration achieved a maximum heat load of 440 Watts, corresponding to a heat flux of approximately 50 Watts per square centimeter, which is significantly higher than the 360 Watts obtained with the nickel wick. Moreover, the copper wick exhibited a performance improvement exceeding 200 percent compared to systems operating with water as the working fluid. These findings indicate that the incorporation of a self-rewetting fluid not only suppresses heat leakage but also enhances overall thermal performance, thereby establishing copper as a viable wick material in such applications. The novelty of this work lies in its comprehensive quantitative evaluation of self-rewetting fluids in disk-shaped flat loop heat pipes, advancing previous efforts by demonstrating marked improvements in heat transfer efficiency and suggesting new design strategies for industrial thermal management.