Design of a single-phase immersion cooling system through experimental and numerical analysis

Abstract

Cooling electronics systems more effectively could enable computer systems to utilize power more efficiently. Immersion cooling is a potential method to cool computers and other electronics by submerging them into a thermal conductive dielectric liquid or coolant. In this study, an innovative cooling structure and procedure of a single-phase immersion cooling system using heat sink and forced circulation is presented. The straight finned heat sink is attached on the CPU surface, and the entire mainboard is submerged in an engineered fluid, 3 M Novec 7100, which is able to dissipate heat and is used in immersion cooling applications. An experimental test is utilized to verify a simulation model built using the computer simulation software. Three circulating speeds of the liquid coolant along with the use of two different materials for the heat sink are chosen to explore the cooling effects of a single-phase immersion cooling system. The heat distribution of the designed model at various flow rates of liquid coolant and materials was observed through the cross-sectional viewpoint and 3D isothermal surface model. The results of the simulations show that the faster flowing speed of liquid coolant would remove more heat, and cause lower temperature of CPU. However, the flow of coolant was encumbered due to slower circulating speed. It also caused the higher temperature values and unbalanced heat distribution. The highest temperatures were measured, and the unbalanced heat distribution of the model was observed. It is noted that the material of the heat sink do not significantly affect the results. These outcomes are able to provide the system designer with useful information to increase power densification and guarantee the safe operation of the related computer, server and communication systems.