Design And Performance Study Of Novel Heat Sink Integrated With Piezoelectric Micropumps

Electronic devices have generally developed towards high power density and miniaturization in recent years,while the heat dissipation problem and the corresponding thermal control solution have become a bottleneck restricting the development of the cutting-edge electronic technology industry.Among many electronic thermal control technologies,the loop liquid cooling technology has the advantages of high efficiency and stability,and plays an important role in the thermal control of electronic devices.However,the loop liquid cooling technology has some shortcomings,such as multi-system components,large space occupancy and complex driving parts,which restrict the development of the loop liquid cooling miniaturization and its application in thermal control of electronic devices.Therefore,the concept of integrating micro heat sink and piezoelectric micropumps is proposed for miniaturization based on the purpose of miniaturization of the loop liquid cooling system,and a novel heat sink integrated with piezoelectric micropumps?PZT-HS?is designed and manufactured.The driving and thermal control performance of the PZT-HS is optimized.In this paper,the main works and results are as follows:?1?The concept of sharing chamber between micro heat sink and piezoelectric micropumps was put forward.Based on the similar structure of chamber between micro heat sink and piezoelectric micropumps,the heat sink integrated with piezoelectric micropumps was designed and manufactured.Calculation formulas of driving performance were established.Different compression parameters of elastic component and different heat transfer enhancement structures were set for optimization.?2?The driving performance experiments measuring system was set up and the driving performance of the PZT-HS was investigated.The influence of different driving parameters and structural parameters on the output flow rate and pressure of the PZT-HS were experimentally studied.The driving parameters included the driving frequency and the driving voltage,and the structural parameters included compression parameters of elastic component and heat transfer enhancement structures.The results demonstrate that the output flow rate of the PZT-HS reach maximum at 15Hz and second maximum at 45Hz.There are two optimum driving frequency segments 10²0Hz and 40⁵0Hz for the PZT-HS.In the range of 0³00V_pp driving voltage,the output flow rate and pressure linearly increased with the driving voltage and all reached maximum at 300V_pp.The best driving performance of the PZT-HS was obtained when the thickness of the elastic component was compressed to 1.8mm.The output flow rate and pressure declined when using nine kinds of heat transfer enhancement structures,and the best driving performance was found on the basic type PZT-HS without heat transfer enhancement structures.?3?The thermal control performance experiments measuring system was set up and the thermal control performance of the PZT-HS was investigated at different driving parameters,inlet temperature and structural parameters experimentally.The results show that the best thermal control performance was obtained at the driving voltage of 300V_pp and the driving frequency of 10Hz.The wall temperature of the PZT-HS was affected by inlet temperature,but the rise of wall temperature and the thermal control performance were not affected by inlet temperature.The thermal control performance became better when the height of fin became larger.While the thermal control performance of the PZT-HS with the combination-shape fin was not good because the combination-shape fin caused a large decrease in the flow rate.In conclusion,the best thermal control performance of the PZT-HS can be reached with 5mm-height fin at 300V_pp and 10Hz.?4?The PZT-HS with the best thermal control performance was applied to the thermal control of the high-power density LED device with the optimized driving parameters.And the LED thermal control experiments measuring system was set up,the heat-pipe-fin heat sink was used for comparison.The experiment shows that the reduction of the LED temperature was1.7³.9?and the enhancement of LED illumination was 2.59%⁹.52%in the steady temperature control.Under the multi cycle intermittent working transient temperature control,the steady temperature state of the LED can be quickly reached within 40 seconds without accumulating excess heat.