Experimental study on the thermal performance of a novel dual diameter closed loop pulsating heat pipe.

Abstract

This study on closed-loop pulsating heat pipes (CLPHP) with a dual-diameter design aimed to enhance heat pipe efficiency by investigating the performance of Methanol, Ethanol, and Ethylene Glycol as working fluids. The research began with understanding the critical role of steady-state conditions in CLPHPs for reliable data collection, emphasizing the importance of consistent flow rates and temperatures. The objective was to assess how different fluids affect the thermal resistance and overall efficiency of CLPHPs, especially under varying power loads. The experiment involved meticulous testing across a power range of 10W to 60W, focusing on observing changes in thermal resistance. Results showed that Methanol exhibited the highest performance, achieving a 70% reduction in thermal resistance between 10W and 60W, thus proving most effective in high heat flux conditions. Ethylene Glycol, on the other hand, demonstrated superior efficiency at lower loads, particularly under 30W. These findings highlighted the effectiveness of the dual-diameter design in enhancing internal circulation and preventing dry-out at higher power levels. The study establishes that a dual-diameter closed-loop pulsating heat pipe can significantly improve heat dissipation when paired with an appropriate working fluid like Methanol. This combination presents a potential solution for managing even higher thermal loads, offering a customizable balance between peak performance and efficiency at varying power ranges. The dual-diameter structure’s contribution to reducing thermal resistance and enhancing capillary forces was a key takeaway, suggesting broader applicability in thermal management systems.