Analysis and experimental validation of a pumped two-phase loop for multi-component electronics cooling

Miniaturization and enhanced performance of microchips has resulted in powerful electronic devices with high heat flux components. For these advanced electronics, the current heat transfer method of single-phase forced convection is reaching its thermal limit and more effective cooling solutions are needed. A pumped two-phase loop, in which a pump circulates a working fluid that evaporates to absorb heat, can offer a solution. In this paper the cooling performance of a pumped two-phase loop is discussed and validated. A numerical tool has been developed to aid in designing a fit-for-purpose pumped two-phase loop and to predict its behaviour to changing system parameters and heat inputs. Results from the numerical model are compared with temperature, pressure and flow velocity measurements obtained from a prototype setup. The effects of applying varying heat loads on both a single evaporator and on multiple evaporators simultaneously either in series or in parallel have been investigated. Heat transfer coefficients between 7 and 10 kW/m²K were obtained during the experiments. Model predictions correspond well to the measured performances and findings on the two-phase boiling behaviour are presented. The model is particularly useful for the rapid assessment of the layout of a pumped two-phase loop for high heat flux electronics cooling.