Two-Phase Liquid Cooling System for Electronics, Part 4: Modeling and Simulations

The fourth article of the present four-part series presents the details of a modeling study using a proprietary two-phase flow simulation code, developed in-house at the LTCM, to predict thermal-hydraulic performance of the pump-driven loop discussed in Part 1 and thermosyphon loop introduced in Parts 2 and 3. The simulation code incorporates LTCM's proven methods for predicting local flow boiling heat transfer coefficients and two-phase pressure gradients in multi-microchannels coupled with a thermosyphon code to simulate all components of the systems together with their operational characteristics and thermal performance. The present simulation tool also provides important guidance for the design of the 18 microcooling zones of the cold plate and louver fin flat tube air-cooled condenser as well as to understand the transient and steady-state contributions of other system components to the overall thermal-hydraulic performance. A comprehensive overview of the modeling and the associated flow charts are first addressed in the present work. Then, the simulation results are compared against the experimental database at the same test conditions resulting in a good agreement. Finally, a sensitivity analysis is performed to investigate the effects of working fluid, thermosyphon height and riser/downcomer diameters on the thermosyphon cooling performance.