Experimental study on pool boiling performance of low GWP fluids

Pool boiling heat transfer plays a crucial role in cooling systems for power electronics, nuclear reactors, data centers, and lithium-ion batteries, where effective heat dissipation is essential to prevent overheating and ensure operational safety and longevity. In the last decades, research has mostly focused on perfluorocarbons, such as FC-72, a commercial version of perfluorohexane with a Global Warming Potential (GWP) of 9000 and hydrofluoreheters. However, there is an ongoing shift toward alternative refrigerants with lower GWP values. This study experimentally investigates pool boiling heat transfer on a smooth aluminium alloy substrate using low-GWP dielectric fluids. The objective is to contribute to the literature by providing a database on the pool boiling performance of lower GWP fluids in comparison with FC-72. The working fluids under investigation are: Novec-649, HFE-7100, TMC-49, and Opteon™ SF33, all suitable for heat transfer applications in direct electronics cooling. Despite similar thermal properties of the fluids, boiling curves differentiate for both Critical Heat Flux and superheat values.