Computational method for system-level analysis of two-phase pumped loops for cooling of electronics

Abstract

Two-phase pumped-loop systems are being actively explored for the cooling of high-heat-flux electronics cooling because of their compactness and low thermal resistance. A typical two-phase pumped loop consists of a microchannel heat sink based evaporator, a finned-tube condenser, a reservoir, and a positive displacement pump. In the present study, the physics of operation of a two-phase pumped-loop system is presented. A two-level computational method, involving coupled component-level and system-level analyses, is then presented for predicting the performance of this system. Component models for the finned-tube condenser and the microchannel-heat-sink evaporator incorporate analysis of one-dimensional two-phase flow within the flow passages combined with correlations for friction factor and heat transfer coefficient under two-phase conditions. Further, the component model for the microchannel-heat-sink evaporator considers the interaction between conduction in the solid region and two-phase flow in individual channels. The system-level solution exploits the simplicity of the two-phase loop to analyze system-level interactions among the components. The computational method has been applied for the analysis of the performance of a practical two-phase pumped loop. Results of analysis illustrate the utility of the computational model in the design of two-phase pumped-loop systems.