Thermal performance evaluation of electronic fluorinated liquids for single-phase immersion liquid cooling

The regulation and prediction of the cooling performance by thermal properties of electronic fluorinated liquids (EFLs) are critical challenges in EFL selection and development for single-phase immersion liquid cooling (SPILC) systems in data centers. To address this, this paper proposes a figure of merit (FOM) to guide the selection and development of EFLs for SPILC systems. An integrated experimental platform is constructed to measure EFL thermophysical properties over a wide temperature range. The influence mechanism of thermophysical properties of different EFLs on the flow and heat transfer performance of SPILC systems is numerically investigated. The results indicate that FOM is effective and reliable in evaluating EFL performance. According to the importance of FOM, the ranking order of thermophysical properties for EFLs is dynamic viscosity > thermal conductivity > density > specific heat capacity. With increasing temperature, only the weight factor of dynamic viscosity increases, while weight factors of other thermophysical properties decrease. Moreover, the average Nusselt number and pressure drop of a SPILC cabinet using the EFL with the lowest dynamic viscosity increases by 57.3% and decreases by 59%, respectively. Therefore, when selecting and designing EFLs in data centers, efforts should be made to minimize their dynamic viscosity.