Thermodynamic analysis of two-fluid, two-phase immersion cooling system for cooling of electronic components

Abstract

Two-phase immersion cooling system is a specialized and increasingly popular method for cooling high-power density electronic components, such as CPUs, GPUs, and other server equipments. In a typical two-phase immersion cooling system, a dielectric fluid is employed for immersing electronic components. The challenge lies in the fact that the fluid chosen often has limited thermal conductivity, hindering effective heat transfer. In a two-fluid immersion cooling system, electronic components are submerged in a dielectric fluid known as the boiling fluid. Within the same tank, a separate condensing fluid is introduced, which is immiscible with the boiling fluid. The condensing fluid, characterized by its lower density and higher thermal conductivity compared to the boiling fluid, enhances heat transfer within the system. In the current study, Novec 7100 serves as the boiling fluid, while deionized water is employed as the condensing fluid. In this work, exergy analysis is conducted to assess and compare the efficiency of a two-fluid, two-phase immersion cooling system in contrast to a single-fluid, two-phase immersion cooling system. Additionally, a comparison is carried out to evaluate how the performance of the system varies under diverse operating conditions. The study is conducted for a maximum heat flux of 12.3 W/cm2 and performance of the system is evaluated at condenser inlet temperatures spanning from 5 to 25 °C. From the investigations carried out, it is seen that the exergy efficiency of the two-fluid system surpasses that of the single-fluid system by approximately 70% under same heat flux and condenser inlet temperature conditions.