Experimental and simulation study on flow heat transfer characteristics of flat pulsating heat pipe with wide and narrow interphase channels

The miniaturization and high density of electronic devices have made temperature control an increasingly important technical challenge. This paper presents a design for a wide and narrow interphase channel plate pulsating heat pipe to address the issue of efficient and stable operation under horizontal and negative inclination angles. A test platform was constructed to evaluate the performance of the heat pipe. The study investigated the operating characteristics of plate pulsating heat pipes in wide and narrow interphase channels by controlling different dip angles, filling rates, and cooling water temperatures. Numerical simulations were conducted using Fluent for 30 % and 50 % filling rates at 90 degrees inclination angle. The results indicated that the wide and narrow channel plate pulsating heat pipe can operate stably at a 50 % liquid filling rate and a -5 degrees incline angle. At an incline angle of 60 degrees and a filling rate of 50 %, the study observed a minimum thermal resistance of 0.44 K/W at 60 W heating power. The influence of different cooling water temperatures on the average temperature difference in the evaporation section decreases as the heating power increases. The working medium undergoes three stages during the start-up stage: bubble formation, bubble growth, and gas plug movement.