Novel pulsating heat pipe for high density power data centres: performance and flow regime analysis

With the advancement of technologies such as Artificial Intelligence and 5G telecommunications, where computational rate is constantly pushing its limits, highly efficient and reliable cooling devices are starting to become an overly critical factor. Not only good performance and reliability are needed, but final users are also aiming to minimize maintenance and costs. These are the reasons why a device that uses inherent forces of two-phase flow is so attractive. In this paper, a novel pulsating heat pipe is presented, and its performance is tested with a low-GWP working fluid. The novel pulsating heat pipe has a footprint area of 75 x 65 mm(2) and a height of 18.5 mm. The secondary side of the device is water-cooled. The experimental results highlight how the flow regimes detected via the temperature's readings affect the thermal performance. The performance of the pulsating heat pipe is defined as the maximum heat load dissipated from the source, while maintaining its base temperature to a value of 90 degrees C. Among all the conditions tested, the best performance was achieved with the refrigerant R1233zd(E), able to dissipate 850 W (heat flux of 30 W/cm(2)), corresponding to an overall thermal resistance of 0.065 K/W.