Conjugate heat transfer for single phase immersion cooling of CPU

Abstract

This study develops a new design of a single-phase immersion cooling system for CPU in computers. The system consists of a loop filled with a dielectric liquid. Recirculation, which facilitates conjugate heat transfer, is driven by thermal convection without the assistance of a fan or pump. A key innovation which allows a sustained convective flow is the asymmetric geometry of the pipe, including a section of a multi-staged Tesla valve which restricts the fluid flow to one direction. The feasibility of the system is tested by CFD (computational fluid dynamics) simulations with two choices of liquid: mineral oil and FC-3283. It is found that the case with FC-3283 attains a greater degree of cooling compared to mineral oil. In both cases, the temperature of CPU is shown to be in the range that is suitable for real applications. Suggestions are made for future explorations of the geometric effect in closed-loop cooling systems.

Keywords

• Immersion cooling
• Conjugate heat transfer
• Tesla valve