Research On Piezoelectric Pump For Computer CPU Cooling Device Of Monitoring Center Of Hydropower

Hydropower station monitoring system not only acts the pat of traditional monitoring,it also has the important function of online and remote monitoring of power equipment and other parameters,so greater demands are being placed on the reliability of its monitoring system.The heat generated by the many electronic components in the monitoring center of the hydropower station makes the computer CPU in a high temperature environment.The monitoring system has the hidden danger of system failure due to the high temperature of the computer CPU.The traditional air-cooled cooling method used by the hydropower station monitoring center itself has the disadvantage of low cooling efficiency and cannot meet the heat dissipation requirements.In addition,as a power source of the CPU water-cooling device,the electromagnetic pump cannot be used for a long time because of the disadvantages of excessive heat generation and electromagnetic interference.The miniature piezoelectric pump with piezoelectric material as the driver has the characteristics of high integration,fast response,low energy consumption and no electromagnetic interference,which has attracted the attention of many research groups at home and abroad.At present,piezoelectric pumps used in CPU water-cooling devices need to be driven at AC voltages above 100 Hz to have good output performance.In view of this problem,the piezoelectric pump researched in this paper can work normally at 50 Hz household AC voltage.The improved piezoelectric pump water-cooling device has high integration and occupies a small computer case.In this paper,the research work and the results of the piezoelectric pump are as follows:1.Analyzing the characteristics of piezoelectric ceramic materials,four vibration modes and support modes of piezoelectric vibrators.The factors affecting the volume change of the piezoelectric pump are discussed according to the formula of the piezoelectric vibrator deformation,which provides a basis for the selection of reasonable parameters of the piezoelectric vibrator.2.Using ANSYS software to perform a modal analysis of the piezoelectric vibrator to obtain the modal modes of the piezoelectric vibrator and their corresponding natural frequency values.The first-order vibration mode is selected as the mode of the piezoelectric vibrator.The relationship between the voltage and the center displacement of the piezoelectric vibrator is obtained by simulation calculation using COMSOL software.The relationship between the limit flow of the piezoelectric pump and the frequency and the center displacement of the piezoelectric vibrator is derived theoretically,and the theoretical limit flow of the piezoelectric pump is calculated by MATLAB software to be288ml/min.The effect of high piezoelectric pump cavity on output performance isdiscussed through the compression ratio theory.3.The overall structure of the piezoelectric pump is designed,and an improved check valve structure is proposed.The theoretical analysis of the relationship between the performance of the globe valve and the material properties,the length of the cantilever and the thickness of the valve.The influence of the hysteresis of the stop valve on the performance output of the piezoelectric pump was discussed.4.The piezoelectric pump prototype is processed through MEMS,3D printing and laser marking technology.A piezoelectric pump test platform is built,and the center displacement of the piezoelectric vibrator is 136?m under 220 V driving.The output flow and output pressure of the piezoelectric pump are tested.When the pump cavity height is0.9mm and the cut-off valve thickness is 0.075 mm,the piezoelectric pump has excellent output performance.When the shut-off valve gasket is added,the output flow of the piezoelectric pump is increased by about 19%.At a room temperature of 26?,the piezo pump was integrated with the CPU cooler and the heat dissipation effect of the simulated CPU heating plate was tested.The test results show that the temperature of the simulated CPU heating chip with different power decreases by about 20? after water cooling cycle.