Computational method for generalized analysis of pumped two-phase cooling systems and its application to a system used in data-center environments

Two-phase pumped-loop systems are being actively considered for cooling of high heat load electronics. In the present study, a computational method based on a two-level approach is developed for generalized system-level analysis of two-phase pumped-loop cooling systems containing multiple branches under steady-state conditions. Detailed one-dimensional analysis of components with distributed two-phase flow is performed to determine their flow and thermal characteristics. System-level analysis utilizes these compact representations for analyzing the component interaction in a generalized manner to predict the system performance. Component models have been developed for the microchannel-heat-sink, finned-tube evaporator and condenser, reservoir, and positive displacement pump. In order to illustrate the utility of the computational method in the design of practical two-phase cooling systems, it has been applied for the analysis of a pumped-loop system being explored for the cooling of hot-air exhausts from server racks in data centers. The system consists of multiple finned-tube evaporators in parallel branches, a water-cooled condenser, a reservoir, and a pump. Results of the analysis show the occurrence of flow maldistribution among the evaporators due to absorption of varying heat loads.