Long-term performance evaluation of micro-scale two-phase heat transport device driven by EHD conduction

Micro-scale heat transport devices driven by electrohydrodynamic (EHD) conduction pumping have been successfully developed over the last several years and can operate efficiently for short periods of time. The pumps are made up of specially designed electrodes which generate an intense electric field and result in flow of a dielectric liquid. The pumps are used upstream of an evaporator in a two-phase loop, where the fluid undergoes phase-change and heat transport takes place. While the short-term operation is established, very few studies have been dedicated to operating these devices for extended periods of time. The results in this paper demonstrate operation of a micro-scale electrohydrodynamic pump intermittently for 105 hours and the pressure generation, heat transport and flow rate for two-phase flow are used as measures of performance. The results indicate that the EHD conduction pump can operate successfully for a considerable amount of time without significant deterioration in pump performance. A better understanding of the possible changes in working fluid properties, electrode surface properties and electrochemical interactions can lead to ever more optimized systems that can be run indefinitely. These are important results for potential applications of this technology which require continuous, reliable operation.