阀的优化设计对压电泵输出性能影响的实验研究

发布时间：2018-08-19 12:53

【摘要】：功能材料因其成本低、性能稳定、制造历史悠久现已成为先进制造技术的主要应用材料之一，而其中的压电材料更是因为其优良的特性得到了广泛的应用，并由此开发出了许多驱动与控制器件，压电泵作为其中的产品之一近年来也已获得了长足的发展，压电泵是利用压电材料的逆压电效应使压电振子产生弯曲变形,再由变形产生泵腔的容积变化来实现流体输出或者利用压电振子产生波动来传输液体。进而实现了结构简单、体积小、重量轻、耗能低、安装使用方便等优点,并可根据实际需要通过调节输入的电压或频率值来控制输出流体的流量和压力。压电泵也在小型移动设备、CPU及显示卡的冷却系统、游戏机控制板、刀片服务器、光生伏打电池、家电、医疗器械（胰岛素泵等）、石化设备、汽车和航空电子设备的水冷系统等诸多领域得到了应用，由于其突出的优点，近年来关于压电泵的研究也已受到了广泛的关注，而就目前而言，压电泵还存在输出流量低、稳定性差、最大输出压力低、寿命短、气泡现象明显、自吸性较差等诸多关键技术问题，，就其发展而言，仍任重而道远！ 1.绪论论述了压电泵的发展历程与国内外研究现状，突出介绍了压电泵的组成及各组成部分对压电泵的综合性能的影响规律，并对其做了理论分析，对压电泵的分类做了简单介绍，并提出了压电泵的关键技术问题，最后强调了被动阀的特性以及对压电泵输出性能的重要影响，基于此，提出了本文的研究重点，即以被动轮式阀为研究方向，通过阀的合理设计来寻求提高压电泵输出性能的方法。 2.阀的限位与预紧主要介绍了压电泵输出流量的计算方法，并与实验测试进行对比，发现实际流量与理论计算值存在较大差距，并就此现象进行了理论分析，考虑到近似计算时忽略了阀的工作状态对压电泵输出特性的影响，因此提出导致实际流量值与理论计算相差较大的原因是被动阀的效率低所致，本文试图采用对阀施加限位与预紧的方法进行优化，改变阀片的开启压力和最大开启高度，减少反向泄露，以达到提高阀的工作效率的目的，并根据不同预紧高度、不同限位高度进行正交试验，结论表明：合理的限位与预紧可以提高压电泵的整体输出性能。 3.多阀泵的理论分析与实验测试基于流体与结构存在耦合关系，推导了流固耦合产生的附加阻尼计算公式，计算了阻力系数，由阻尼系数计算公式可知：阻尼系数与腔体高度的3次方成反比，与驱动器直径的4次方成正比，随阀孔与驱动器的半径比成对数增加，在驱动器半径，腔体高度确定的情况下，可以通过增加阀孔的水力直径的方式减小阻力系数，基于此设想对入口阀采用三阀并联的方式进行设计，保证单个阀片阻力不变的情况下增大整体的等效直径，从而减小阻尼，以达到减小能量损失增大压电泵的输出流量与最佳工作频率的目的，并对单阀泵与三阀并联泵进行了实验测试，结果显示：通过对入口阀进行并联设计可以有效的减小其阻尼系数，由于能量损失降低，压电泵最终的输出性能增强。 4.阀的匹配实验通过对压电振子的输出特性进行理论分析发现：在压电振子尺寸固定以及输入激励不变的情况下，压电振子的输入功率基本不变，而决定压电泵最终的输出能力则取决于阀片的效率，而分析发现：增加阀片的开度并非一定能让压电泵的输出流量有所提升，经仿真分析发现，当阀片的开度增大到一定程度的情况下，泵腔内的压力变化趋缓，此时继续增大阀片的开度反而会导致压电泵的输出流量降低，这是由于因滞后现象明显从而反向泄露增加所致，经试验测试表明：通过改变阀孔的大小、阀孔与阀堵的尺寸匹配、不同厚度阀片的刚度匹配，压电泵的输出流量大大提高。试验结果显示：在其它结构参数不变的情况下存在一种最佳的阀孔尺寸使得压电泵的输出流量最大，对于阀片与阀堵配合尺寸也是如此，另外，对不同厚度阀片进行刚度匹配可以使得压电泵的输出流量最大。当入口阀厚度0.075mm；中间阀厚度0.18mm；出口阀厚度0.075mm时，泵的输出性能最好，最大流量为635.46ml/min,最佳频率为190Hz。 5.35型双腔压电泵的样机试制与性能测试以f35型双腔串联压电泵为试验样机，对双腔串联压电泵进行了原理分析，并对泵的压力、流量、自吸性进行了测试，结果表明：经过阀的合理匹配，该泵在130V驱动电压下，最大流量可达到678ml/min,零流量时的输出压力可达32kpa，最佳频率为200Hz，同时最大自吸高度可达到40cm。
[Abstract]:Because of its low cost, stable performance and long manufacturing history, functional materials have become one of the main application materials of advanced manufacturing technology, and piezoelectric materials have been widely used because of its excellent characteristics, and many drive and control devices have been developed. Piezoelectric pumps as one of the products have also been obtained in recent years. Piezoelectric pumps have made great progress. Piezoelectric pumps use the inverse piezoelectric effect of piezoelectric materials to bend the piezoelectric oscillator, and then change the volume of the pump cavity to achieve fluid output or use the piezoelectric oscillator to generate fluctuations to transfer liquid. Piezoelectric pumps are also used in small mobile devices, CPU and display card cooling systems, console boards, blade servers, photovoltaic batteries, household appliances, medical devices (insulin pumps, etc.), petrochemical equipment, automobiles and avionics. The water-cooling system of the equipment has been applied in many fields. Because of its outstanding advantages, the research on piezoelectric pump has been paid more and more attention in recent years. At present, the piezoelectric pump still has many key problems, such as low output flow, poor stability, low maximum output pressure, short service life, obvious bubble phenomenon, poor self-priming and so on. As far as its development is concerned, it still has a long way to go.
1. introduction
This paper discusses the development history of piezoelectric pumps and the present research situation at home and abroad, highlights the composition of piezoelectric pumps and the impact of each component on the comprehensive performance of piezoelectric pumps, and makes a theoretical analysis of the piezoelectric pumps, a brief introduction to the classification of piezoelectric pumps, and puts forward the key technical issues of piezoelectric pumps, and finally emphasizes the characteristics of passive valves. And the important influence on the output performance of the piezoelectric pump, based on this, the research emphasis of this paper is put forward, that is, to find the method to improve the output performance of the piezoelectric pump through the reasonable design of the passive wheel valve.
Limit and pretightening of 2. valves
This paper mainly introduces the calculation method of the output flow of piezoelectric pump and compares it with the experimental test. It is found that there is a big gap between the actual flow and the theoretical value. The theoretical analysis is made on this phenomenon. Considering that the influence of the working state of the valve on the output characteristics of the piezoelectric pump is neglected in the approximate calculation, the value and theory leading to the actual flow are proposed. The reason for the great difference in calculation is the low efficiency of the passive valve. This paper tries to optimize the valve by applying limit and pre-tightening method, changing the opening pressure and maximum opening height of the valve disc, reducing reverse leakage, so as to improve the efficiency of the valve and orthogonalizing the valve according to different pre-tightening heights and different limit heights. The test results show that the reasonable limit and pre tightening can improve the overall output performance of the high voltage electric pump.
Theoretical analysis and experimental test of 3. multi valve pump
Based on the coupling relationship between fluid and structure, the formulas for calculating the additional damping caused by fluid-structure coupling are deduced and the resistance coefficient is calculated. From the formulas for calculating the damping coefficient, the damping coefficient is inversely proportional to the third power of the cavity height, and is proportional to the fourth power of the diameter of the actuator. When the radius and the height of the cavity are fixed, the resistance coefficient can be reduced by increasing the hydraulic diameter of the valve orifice. Based on this assumption, the inlet valve is designed in parallel with three valves to increase the overall equivalent diameter without changing the resistance of a single valve slice, thereby reducing the damping and reducing the energy loss and increasing the pressure. The experimental results show that the damping coefficient can be effectively reduced by parallel design of the inlet valve, and the final output performance of the piezoelectric pump is enhanced due to the reduction of energy loss.
Matching experiment of 4. valves
Through the theoretical analysis of the output characteristics of piezoelectric oscillator, it is found that the input power of piezoelectric oscillator is basically unchanged when the size of piezoelectric oscillator is fixed and the input excitation is unchanged, and the final output capacity of piezoelectric pump depends on the efficiency of the valve. The analysis shows that increasing the opening of the valve does not necessarily make piezoelectric. The output flow of the pump has been increased. The simulation results show that when the opening of the valve slice increases to a certain extent, the pressure change in the pump cavity slows down. At this time, the output flow of the piezoelectric pump will decrease if the opening of the valve slice continues to increase. This is due to the obvious phenomenon of hysteresis and the increase of reverse leakage. The test table shows that Ming: By changing the size of the valve hole, the size of the valve hole and the valve plug matching, the stiffness of the different thickness of the valve plate matching, the output flow of the piezoelectric pump greatly improved. In addition, the output flow of the piezoelectric pump can be maximized by matching the stiffness of the valve plates with different thicknesses. When the inlet valve thickness is 0.075 mm, the intermediate valve thickness is 0.18 mm, and the outlet valve thickness is 0.075 mm, the output performance of the pump is the best, the maximum flow rate is 635.46 ml/min, and the optimal frequency is 190Hz.
Prototype manufacture and performance test of 5.35 type double cavity piezoelectric pump
Taking F35 series piezoelectric pump with two cavities as the experimental prototype, the principle of the pump is analyzed, and the pressure, flow and self-priming of the pump are tested. The results show that the maximum flow rate can reach 678 ml/min under 130V driving voltage, and the output pressure can reach 32 kPa at zero flow rate and the optimum frequency is 20. 0Hz, and the maximum self suction height can reach 40cm..
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：TH38

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