Radius, number and distribution of pump cavity jet holes of piezoelectric jet pump

Abstract

The invention relates to an improved design of a jet pump for driving fluid, which is characterized in that analogue simulation optimization and test are carried out on radiuses and distribution of jet holes of a pump cavity of a piezoelectric jet pump and the like as well as a relationship between the number and flow to obtain a value range, an optimal value and a position of the radius of the jet holes of the pump cavity corresponding to the maximum flow and the number of the corresponding jet holes; and the pump flow is greatly improved.

Description

Technical Field

[0001] An improved design of a jet pump for driving fluid is proposed. Simulation optimization and experiment are carried out on the radius and number of jet holes in the pump chamber of a piezoelectric jet pump, as well as the relationship between their distribution and flow rate. The range and optimal value of the radius of the pump chamber jet holes corresponding to the maximum flow rate, the position distribution and the number of jet holes are obtained, and the pump flow rate is greatly improved. Background Art

[0002] In the design of the piezoelectric jet pump, the piezoelectric micro blower designed in CN101542122A, that is, the piezoelectric driven gas jet pump is shown in Figure 2 (the original attachment of CN101542122A). Figure 1 ), and the porous jet pump 202411094690.1 previously applied by the applicant is designed as follows Figure 1 As shown. The piezoelectric ceramic 1 of the piezoelectric actuator is driven by an alternating signal to bend and deform up and down and drive the air, so that the fluid in the pump chamber is compressed or expanded, and a large positive or negative pressure is generated in the pump chamber: During the positive pressure period, the fluid (such as air) in the pump chamber is ejected at high speed from the small hole jet hole on the upper wall of the pump chamber, forming a cylindrical high-speed fluid jet, which passes through the interlayer and flows out through the corresponding small hole jet hole of the pump housing (as shown in Figure 2 d). During the negative pressure period, the fluid (such as air) in the interlayer is sucked into the pump chamber through the small hole jet hole on the upper wall of the pump chamber (as shown in Figure 2 b). Thus, a non-return fluid jet pump that does not require a check valve is obtained.

[0003] For the jet pump designed above, the applicant optimized the thickness of the pump barrier in the prior application 202411415732.7, and obtained a significant increase in the pump flow rate. The simulation and the experiment are consistent, and the technical effect is significant. Summary of the invention

[0004] In order to further optimize the performance of the jet pump, a large number of simulation explorations and trial and error were carried out on the radius, distribution and number of the jet holes on the pump chamber to find new improvements to increase the pump flow rate. After a large number of simulation calculations, a set of better design parameters and the relationship between the radius, distribution and number of jet holes and the flow rate were obtained, as shown in Table 1. The maximum flow rate of the pump is as high as 3696 ml / min, which is more than twice the 1700 ml / min before optimization. According to the simulation results, when the radius of the pump cavity jet hole is less than 150 microns, the thickness of the pump is reduced, but the pump flow rate is not only not reduced, but increased, and there is an optimal value, the pump flow rate is the largest. This has a huge impact on the design of the jet pump, and the technical effect is very significant. When the radius of the pump cavity jet hole is in the range of 100 to 145 microns, the pump flow rate is above 2000 ml / min. In the range of 110 to 135 microns, the pump flow rate is greater than 2400, and in the range of 125 to 130, the pump flow rate is greater than 3000. When the radius of the pump cavity jet hole is 130 microns, the pump flow rate is the largest, which is 3696 ml / min.

[0005] The reasonable explanation for the above results is that when the jet hole radius gradually decreases from 300 microns to 150 microns to 100 microns, first, under the premise that the total area of ​​the jet hole (the number of jet holes or the number multiplied by the area of ​​a single jet hole) remains roughly unchanged, the pump chamber pressure at the jet hole remains basically unchanged, and the smaller the jet hole radius, the greater the jet velocity, and the greater the total flow rate (jet velocity multiplied by the total jet area). However, when the jet hole radius is too small, the viscous resistance encountered by the air when flowing through the jet hole becomes larger and larger, so there is a better range or optimal value of the jet hole radius. When it is smaller than this range, the viscous resistance encountered by the air when flowing through the jet hole becomes larger and larger, and the flow rate is affected by the large viscosity and becomes smaller and smaller.

[0006] Through experiments, it is confirmed that the radius, position and number of the jet holes have a significant correlation with the flow rate of the pump. Figure 1The designed pump cavity has a jet hole radius of 150 microns, a number of four holes, and a barrier height of 750 microns, with a flow rate of 1400 ml / min. In the actual sample preparation test, the flow rate was 1700 ml / min. In this optimization, it was further found that when four jet holes with a radius of 220 microns were taken, and the jet holes were roughly distributed on the center line of a circle with a radius of 600 microns and the center of the pump cavity as the center, the flow rate was the largest when other parameter sizes remained unchanged, which was 1937 ml / min. When the radius of the jet hole is reduced and the number of the jet holes is increased to maintain the total jet area greater than or equal to the total area of ​​the four 220 micron jet holes, the number of jet holes increases from four to 8, 16, 24, 32, and 40, and the radius of the jet hole gradually decreases, the total jet area gradually increases, the radius of the center line of the jet hole circle gradually increases, and the flow rate gradually increases to the peak value and then decreases: from 1937 for four 220 micron jet holes to 2213, 2643, 3204, 3696, and 2412 ml / min. The flow peak occurs in the combination of 32 jet holes with a radius of 130 microns, and the jet holes are roughly distributed on a circle with a radius of 1350 microns with the center of the pump cavity as the center, and the corresponding flow peak is 3696 ml / min.

[0007] Table 1 Relationship between the number, radius and position of jet holes and the maximum flow rate Number of jet holes Optimal radius of jet hole (micrometer) Radius of the center line of the jet hole (micrometer) Maximum flow rate (ml / min) 4 220 600 1937 8 150 750 2213 16 140 1100 2643 24 135 1100 3204 32 130 1350 3696 40 115 1500 2412 The data in Table 1 is a comparison of the maximum flow rate corresponding to the optimal jet hole radius and position for each number of jet holes. For example, the flow rate of 3696 ml / min for 32 jet holes in Table 1 is obtained by finding the optimal radius with the maximum flow rate in the range of 100 to 220 microns under the premise of 32 jet holes, and then performing simulations of various design combinations near the optimal radius to obtain the final maximum flow rate and the corresponding jet hole radius value and position size. Therefore, Table 1 is a comparison of the maximum flow rate corresponding to the number, radius and position of each jet hole, which contains a large number of simulation calculations.

[0008] Since this design is based on the piezoelectric material with a radius of 5500 microns, the radius of the center line of the jet hole in this application can be calculated based on the radius of the piezoelectric material. For example, the radius of the center line of the jet hole corresponding to the peak flow rate of 3696 ml / min is 1350 microns. It can also be expressed as the radius of the center line of the jet hole is 1350 / 5500=27 / 110 of the radius of the piezoelectric material.

[0009] According to the above analysis, the jet pump preferably uses 5 or more jet holes; more preferably, 8 or more jet holes; more preferably, 16 or more jet holes; more preferably, 24 or more jet holes; more preferably, 32 or more jet holes. The jet hole radius is preferably selected: the jet hole radius is preferably 220+ / -50 microns or 220+ / -30 microns; more preferably, the jet hole radius is 100-145 microns; more preferably, the jet hole radius is preferably 110-140 microns; more preferably, the jet hole radius is preferably 120-135 microns; more preferably, the jet hole radius is preferably 125-135 microns. At the same time, the jet holes are roughly distributed on the second diaphragm with the center of the pump cavity as the center, and the radius is preferably in the range of 750-1500 microns, or (3 / 22-3 / 11) of the radius of the piezoelectric material. It is further preferred that the jet holes are roughly distributed on a circle with a radius of 800 to 1500 microns, or (8 / 55 to 3 / 11) of the radius of the piezoelectric material; it is further preferred that the jet holes are roughly distributed on a circle with a radius of 1100 to 1400 microns, or (1 / 5 to 14 / 55) of the radius of the piezoelectric material; it is further preferred that the jet holes are distributed on a circle or annular belt with a radius of 1100+ / -100 microns, or (1 / 5+ / -1 / 55) of the radius of the piezoelectric material; it is further preferred that the jet holes are distributed on a circle or annular belt with a radius of 1350+ / -100 microns, or (27 / 110+ / -1 / 55) of the radius of the piezoelectric material. The above preferences for the radius, position and number of the jet holes can be performed individually or in combination. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 A cross-sectional view of the design of the present application is shown schematically.

[0011] Figure 2 The prior art CN101542122A is shown as follows: Figure 1 .

[0012] In the figure, 1 is the piezoelectric or other material actuating component of the fluid pump, 2 is the gasket of the piezoelectric actuating component, 3 is the diaphragm, 4 is the pump cavity, 5 is the second diaphragm, 6 is the air inlet partition, 7 is the N number of pump cavity jet holes, 8 is the opening of the pump housing 9, the fluid outlet of the pump, 9 is the pump housing, 10 is the side wall opening of the partition, the pump inlet. The feeding electrode and the like are omitted in the figure. DETAILED DESCRIPTION

[0013] Combined with Figure 1, giving the specific implementation method of the present application, and further expounding the design concept of the present application. According to the mechanism proposed in the present application, it can be promoted and applied to various jet fluid pumps driven by electromagnetic actuation materials such as piezoelectric without creative labor. It only needs to imitate the analysis of pressure distribution and air intake in the present application to realize non-return jet fluid delivery in various designs, including but not limited to the design of the present application, and other actuation materials or mechanically driven fluid pumps, and obtain a significant improvement in efficiency.

[0014] exist Figure 1 In the figure, each element is basically circular, with the central symmetry line as the axis, but the shape of the pump can be circular or square without restriction. The feeding electrode and the like are omitted in the figure. The electromagnetic actuating component 1 is made of piezoelectric material or other materials, which bends and deforms up and down under the action of electric and / or magnetic signals, driving the gasket 2 and the diaphragm 3 to bend and deform together, resulting in a significant change in the volume of the pump chamber 4, forming a large positive pressure or negative pressure. When the pump chamber is compressed, the high-pressure fluid flows out of the pump chamber jet hole 7 at a high speed, passes through the air inlet partition 6, and flows out to the outside through the pump housing outlet 8. When the pump chamber expands, the fluid in the partition 6 under negative pressure is attracted and flows into the pump chamber. Multiple jet holes 7 are arranged in the high-pressure area of ​​the pump and are reasonably distributed to make full use of the energy of all high-pressure areas. In order to avoid "backflow", the height of the partition 6 is set to be 5 times the radius of the jet hole of the pump chamber. Thereby avoiding that during the process of pump chamber suction and expansion, the vertical distance between the pump housing outlet 8 and the pump chamber jet hole 7, that is, the height of the partition, is too small, and the pump housing outlet 8 enters the influence range of the pump chamber suction. According to the simulation optimization results, multiple pump cavity jet holes are set, such as 8 to 32. According to the optimal radius and the optimal position distribution of the jet holes under each number obtained by the simulation optimization, experimental verification is carried out to obtain the maximum flow rate of the pump. The flow rate is more than doubled compared with the prior art, the effect is obvious, simple and practical. At the same time, when the design optimized by this application is adopted, not only the flow rate is increased, but also the thickness of the pump is reduced, because the radius of the jet hole is reduced from 220 or 150 microns to 130 microns. The thickness of the interlayer of the pump is also reduced from five times of 220 or 150 microns, that is, 1100 or 750 microns, to five times of 130 microns, that is, 650 microns. That is, under the premise of thinner interlayer thickness and pump thickness, this design has achieved the technical effect of nearly doubling the flow rate of the pump.

[0015] It should be pointed out that each dimension in the present application has a certain error range. Due to the slight differences in material parameters, processes and structures, the dimensions of the optimized parameters in the present application may vary slightly, and these changes or errors are all covered by the protection scope of the present application. Moreover, the dimension parameters of the present application are obtained relative to the diameter of the piezoelectric material 1, which is 11 mm. When the diameter of the piezoelectric material changes, the position dimension of the jet hole in the present application, that is, the radius dimension of the center line of the jet hole, changes in the same proportion as the radius of the piezoelectric material changes.

[0016] The technical core of this application is to obtain the influence of the number, radius and position of the jet holes in the pump cavity on the flow rate of the pump through simulation analysis in a jet fluid pump driven by an electromagnetic actuation material such as a piezoelectric material, and then obtain the appropriate number, radius and position of the jet holes in the pump cavity, thereby obtaining a substantial improvement in the key core performance of the prior art - the pump flow rate, and obtaining significant technical progress and technical benefits. This design can be used in the design of other jet pumps without the need for creative labor or overcoming any prejudice. For example, any actuation material driven pump, including a mechanically driven pump, as long as the pump cavity is repeatedly compressed and expanded, can be provided with a number / radius of jet holes 7 with simulation optimization on the wall of the pump cavity, and a fluid barrier layer separated by a certain height or distance is provided, and a corresponding outer shell and an opening 8 on the outer shell surrounding the jet hole 7 are provided, so that the compressed fluid in the pump cavity is jetted at high speed, passes through the jet hole 7, the barrier layer and the outlet 8 to flow to the outside; and when inhaling, the fluid is absorbed from the barrier layer to replenish the pump cavity. In the case of a piezoelectric pump, the piezoelectric material can be a single layer or multiple layers, and there can be more than one piezoelectric vibrator, such as Figure 1 The second diaphragm in the device can be replaced by a piezoelectric vibrator, that is, a combination of a diaphragm and a piezoelectric material. Various prior art common jet pump designs, or future jet pump technologies, can be simply introduced into the design of the present application without the need for creative labor.

[0017] The improved design of the present application is supported by simulation and experimental verification, and has achieved significant technological progress and significant technological benefits. The core performance pump flow rate of the pump has been greatly improved from 1700 ml / min of the prior art to 3696 ml / min.

Claims

1. A piezoelectric jet pump for driving fluid, which is composed of piezoelectric material, gasket, diaphragm, pump cavity, second diaphragm, air intake spacer, shell, etc. The second diaphragm is provided with a pump cavity jet hole composed of a plurality of small holes, and the shell is provided with an opening, i.e., an outlet. When the pump cavity is compressed, the fluid forms a high-speed jet, which passes through the second diaphragm, the air intake spacer and the shell through the jet hole of the pump cavity and flows out of the pump body through the outlet of the shell. When the pump cavity expands, the fluid in the air intake spacer flows into the pump cavity through the pump cavity jet hole, characterized in that: The radius of the pump cavity jet hole is in the range of 100-145 microns, or 220+ / -50 microns.

2. The piezoelectric jet pump for driving fluid according to claim 1, further characterized in that: The radius of the pump cavity jet hole is in the range of 110 to 140 microns.

3. The piezoelectric jet pump for driving fluid according to claim 1, further characterized in that: The radius of the pump cavity jet hole is in the range of 120 to 135 microns.

4. The piezoelectric jet pump for driving fluid according to claim 1, further characterized in that: The radius of the pump cavity jet hole is in the range of 125 to 135 microns.

5. A piezoelectric jet pump for driving fluid, which is composed of piezoelectric material, gasket, diaphragm, pump chamber, second diaphragm, air intake spacer, shell, etc. The second diaphragm is provided with a pump chamber jet hole composed of a plurality of small holes, and the shell is provided with an opening, i.e., an outlet. When the pump chamber is compressed, the fluid forms a high-speed jet, which passes through the second diaphragm, the air intake spacer and the shell through the jet hole of the pump chamber and flows out of the pump body through the outlet of the shell. When the pump chamber expands, the fluid in the air intake spacer flows into the pump chamber through the pump chamber jet hole, characterized in that: The center line of the jet hole is a circle with a radius of 800-1500 microns, or (8 / 55-3 / 11) of the radius of the piezoelectric material and with the center of the pump cavity as the center.

6. The piezoelectric jet pump for driving fluid according to claim 5, further characterized in that: The radius of the center line of the pump cavity jet hole is in the range of 1100-1500 microns, or (1 / 5-3 / 11) of the radius of the piezoelectric material.

7. The piezoelectric jet pump for driving fluid according to claim 5, further characterized in that: The radius of the center line of the pump cavity jet hole is in the range of 1100-1400 microns, or (1 / 5-14 / 55) of the radius of the piezoelectric material.

8. The piezoelectric jet pump for driving fluid according to claim 5, further characterized in that: The radius of the center line of the pump cavity jet hole is in the range of 1350+ / -100 microns, or (27 / 110+ / -1 / 55) of the radius of the piezoelectric material.

9. A piezoelectric jet pump for driving fluid, which is composed of piezoelectric material, gasket, diaphragm, pump cavity, second diaphragm, air intake spacer, shell, etc. The second diaphragm is provided with a pump cavity jet hole composed of a plurality of small holes, and the pump shell is provided with an opening, i.e., an outlet. When the pump cavity is compressed, the fluid forms a high-speed jet, which passes through the second diaphragm, the air intake spacer and the shell through the jet hole of the pump cavity and flows out of the pump body through the shell outlet. When the pump cavity expands, the fluid in the air intake spacer flows into the pump cavity, characterized in that: The number of the pump cavity jet holes is 5 or more, and the jet holes are distributed on a circle with a radius ranging from 750 to 1500 microns, or (3 / 22 to 3 / 11) of the radius of the piezoelectric material and with the center of the pump cavity as the center.

10. The piezoelectric jet pump for driving fluid according to claim 9, further characterized in that: The number of the pump cavity jet holes is 8 or more, and the jet holes are distributed on a circle with a radius ranging from 750 to 1500 microns, or (3 / 22 to 3 / 11) of the radius of the piezoelectric material.

11. The piezoelectric jet pump for driving fluid according to claim 9, further characterized in that: The number of the pump cavity jet holes is 16 or more, and the jet holes are distributed on a circle or annular belt with a radius of 1100+ / -100 microns, or (1 / 5+ / -1 / 55) of the radius of the piezoelectric material.

12. The piezoelectric jet pump for driving fluid according to claim 9, further characterized in that: The number of the pump cavity jet holes is 24 or more, and the jet holes are distributed on a circle or annular belt with a radius of 1100+ / -100 microns, or (1 / 5+ / -1 / 55) of the radius of the piezoelectric material.

13. The piezoelectric jet pump for driving fluid according to claim 9, further characterized in that: The number of the pump cavity jet holes is 32 or more, and the jet holes are distributed on a circle or annular belt with a radius of 1350+ / -100 microns, or a range of (27 / 110+ / -1 / 55) of the radius of the piezoelectric material.

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