Vibration processing and designing method and device of axial flow pump and electronic equipment

Abstract

The invention provides a vibration processing and designing method and device for an axial flow pump and electronic equipment. The vibration processing and designing method and device for the axial flow pump are characterized in that an excitation source of high-frequency vibration comes from a standing wave in a guide vane; the method comprises the steps that if the ratio of the sound standing wave frequency on the guide vane blade to the inherent frequency of one of the vibration modes of the guide vane blade under the working condition is smaller than a preset threshold value, mechanical parameters of the guide vane blade are changed so as to change the inherent frequency of the guide vane blade, for example, the part length of the guide vane blade is cut off, therefore, the staggering rate between the sound standing wave frequency and the inherent frequency of the guide vane blade can be increased, resonance is avoided, the amplitude of hydraulic excitation caused by the fact that the distance between the impeller and the guide vane is too close can be reduced, and the vibration response of the blade is reduced. The other method comprises the steps that the ratio of the inherent frequency and the sound standing wave frequency of each mode of the guide vane blade is adjusted to reach the preset threshold value in the design stage of the axial flow pump, and the problems of high-frequency vibration and noise of the axial flow pump are solved from the design link.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of device detection, and in particular to a vibration processing and design method and device for an axial flow pump and an electronic device. BACKGROUND

[0002] There are various types of pumps, such as centrifugal pumps, screw pumps, reciprocating pumps, gear pumps, vane pumps, vortex pumps, gas diaphragm pumps, water ring vacuum pumps, steam jet pumps, piston pumps, Roots vacuum pumps, mud pumps, gas-gas booster pumps, gas-liquid booster pumps, rotary vane vacuum pumps, axial flow pumps, self-priming pumps, and the like. Different types of pumps usually differ greatly in mechanical structure and working principle, and are suitable for different scenarios. An axial flow pump relies on the axial thrust (lift) generated by the blades on the fluid when the impeller rotates to transport the fluid. The fluid flows in the axial direction of the pump, and the flow path is approximately straight. The axial flow pump can achieve a large flow rate by increasing the swept area of the blades and the axial flow rate of the fluid, and the flow rate can reach tens of thousands of m 3 / h. Limited by the length of the blades and the rotational speed, the head of the axial flow pump is usually less than 20 m. Therefore, the axial flow pump is usually suitable for large flow and low head scenarios, such as drainage and irrigation.

[0003] An axial flow pump mainly includes a pump body (elbow) with built-in guide vanes, an impeller, a shaft, a bearing box, and the like. In order to real-time understand the health status of the axial flow pump during operation, a vibration monitoring sensor is usually arranged on the axial flow pump, which can be arranged on Figure 1 measurement points A and B as shown. In Figure 1 , 10 is a pump body, 20 is an impeller, 30 is a guide vane, 40 is a shaft, and 50 is a bearing box.

[0004] Under normal circumstances, the vibration frequency of the axial flow pump is 1-5 kHz. However, the inventors have found that high-frequency vibration and noise with abnormal frequency are sometimes monitored in high-speed axial flow pumps. High-frequency vibration can shorten the service life of the equipment and cause damage, and high-frequency noise can also cause harm to the health of relevant workers. SUMMARY

[0005] The present specification provides a vibration processing and design method, device, and electronic device for an axial flow pump to solve the problem of abnormal high-frequency vibration of the axial flow pump.

[0006] To solve the above technical problems, the first aspect of the present specification provides a vibration processing method for an axial flow pump, comprising: acquiring the natural frequency of each vibration mode of the guide vane blade of the axial flow pump; calculating the acoustic standing wave frequency on the guide vane blade under the working condition of the axial flow pump according to the current mechanical parameters of the guide vane blade; and if the ratio of the acoustic standing wave frequency to the natural frequency of one of the modes is less than a preset threshold, changing the mechanical parameters of the guide vane blade to change the natural frequency of the guide vane blade.

[0007] In some embodiments, changing a mechanical parameter of the guide vane blade to change a natural frequency of the guide vane blade includes cutting off a portion of the length of the guide vane blade.

[0008] In some embodiments, the natural frequency of the guide vane of the axial flow pump is calculated using the following formula:

[0009] Wherein, F is the natural frequency; β is the frequency parameter, which is determined according to the width-to-length ratio of the guide vane. When calculating different vibration modes, the same width-to-length ratio corresponds to different frequency parameter values; a is the width of the free end section of the guide vane; D is the bending strength of the guide vane material; ρ is the material density of the guide vane; h is the thickness of the guide vane, E is the elastic modulus of the guide vane, and v is the Poisson's ratio of the guide vane.

[0010] In some embodiments, the natural frequencies of each vibration mode of the guide vane of the axial flow pump are obtained through a knocking test.

[0011] In some embodiments, the acoustic standing wave frequency of the guide vane blade under the operating conditions of the axial flow pump is calculated by the following formula:

[0012] When the extended length of the guide vane is equal to half the wavelength of the standing wave,

[0013] When the extended length of the guide vane is equal to the wavelength of the standing wave,

[0014] When the expanded length of the guide vane is equal to 1.5 times the wavelength of the standing wave,

[0015] Among them, f0 is the frequency of the acoustic standing wave, c is the speed of sound propagation in water, and L is the expanded length of the guide vane.

[0016] In some embodiments, the value of the preset threshold is greater than 1.1.

[0017] In some embodiments, a target length of the guide vane to be cut off is determined by: obtaining mechanical parameters of the axial flow pump guide vane before cutting; assuming that a first length is cut off from the inlet end of the guide vane, and recalculating the natural frequencies of each vibration mode of the axial flow pump guide vane, the acoustic standing wave frequencies, and the ratios of each acoustic standing wave frequency to the natural frequencies of each mode based on the mechanical parameters of the guide vane after the assumed cutoff; if the ratios are greater than a preset threshold, the first length is used as the target length; if the ratios are less than the preset threshold, the assumed cutoff length is increased to a second length, and the natural frequencies of each vibration mode of the axial flow pump guide vane, the acoustic standing wave frequencies, and the ratios of each acoustic standing wave frequency to the natural frequencies of each mode are recalculated based on the mechanical parameters of the guide vane after the assumed cutoff; if the ratios are greater than the preset threshold, the second length is used as the target length; if the ratios are less than the preset threshold, the assumed cutoff length is increased to a third length, the natural frequencies, acoustic standing wave frequencies, and the ratios are recalculated, and the target length is determined based on the ratios.

[0018] The second aspect of this specification provides a design method for an axial flow pump, including: when designing the guide vanes of the axial flow pump, calculating the natural frequencies of each vibration mode of the guide vanes of the axial flow pump based on the proposed mechanical parameters of the axial flow pump; calculating the acoustic standing wave frequency on the guide vanes under the working conditions of the axial flow pump based on the proposed mechanical parameters of the axial flow pump; if there is a ratio of the acoustic standing wave frequency to the natural frequency of one of the modes that is less than a preset threshold, adjusting the proposed mechanical parameters or material of the guide vanes until the ratio of the acoustic standing wave frequency to the natural frequency of each mode reaches the preset threshold, and the proposed mechanical parameters that make the ratio reach the preset threshold are used as the production basis of the axial flow pump.

[0019] In some embodiments, adjusting the proposed mechanical parameter of the guide vane blade includes increasing or decreasing the size of the guide vane blade of the axial flow pump.

[0020] In some embodiments, the acoustic standing wave frequency of the guide vane blade under the operating conditions of the axial flow pump is calculated by the following formula:

[0021] When the extended length of the guide vane is equal to half the wavelength of the standing wave,

[0022] When the extended length of the guide vane is equal to the wavelength of the standing wave,

[0023] When the expanded length of the guide vane is equal to 1.5 times the wavelength of the standing wave,

[0024] Among them, f0 is the frequency of the acoustic standing wave, c is the speed of sound propagation in water, and L is the expanded length of the guide vane.

[0025] In some embodiments, the value of the preset threshold is greater than 1.1.

[0026] The third aspect of this specification provides a vibration processing device for an axial flow pump, including: an acquisition unit for acquiring the natural frequencies of each vibration mode of the guide vane blade of the axial flow pump; a first calculation unit for calculating the acoustic standing wave frequency on the guide vane blade under the working conditions of the axial flow pump based on the current mechanical parameters of the guide vane blade; a processing unit for changing the mechanical parameters of the guide vane blade to change the natural frequency of the guide vane blade if the ratio of the acoustic standing wave frequency to the natural frequency of one of the modes is less than a preset threshold.

[0027] In some embodiments, changing a mechanical parameter of the guide vane blade to change a natural frequency of the guide vane blade includes cutting off a portion of the length of the guide vane blade.

[0028] In some embodiments, the natural frequency of the guide vane of the axial flow pump is calculated using the following formula:

[0029] Wherein, F is the natural frequency; β is the frequency parameter, which is determined according to the width-to-length ratio of the guide vane. When calculating different vibration modes, the same width-to-length ratio corresponds to different frequency parameter values; a is the width of the free end section of the guide vane; D is the bending strength of the guide vane material; ρ is the material density of the guide vane; h is the thickness of the guide vane, E is the elastic modulus of the guide vane, and v is the Poisson's ratio of the guide vane.

[0030] In some embodiments, the natural frequencies of each vibration mode of the guide vane of the axial flow pump are obtained through a knocking test.

[0031] In some embodiments, the acoustic standing wave frequency of the guide vane blade under the operating conditions of the axial flow pump is calculated by the following formula:

[0032] When the extended length of the guide vane is equal to half the wavelength of the standing wave,

[0033] When the extended length of the guide vane is equal to the wavelength of the standing wave,

[0034] When the expanded length of the guide vane is equal to 1.5 times the wavelength of the standing wave,

[0035] Among them, f0 is the frequency of the acoustic standing wave, c is the speed of sound propagation in water, and L is the expanded length of the guide vane.

[0036] In some embodiments, the value of the preset threshold is greater than 1.1.

[0037] In some embodiments, the processing unit includes: an acquisition subunit for acquiring the mechanical parameters of the guide vane blade of the axial flow pump before it is cut off; a first calculation subunit for assuming that a first length is cut off from the inlet end of the guide vane blade, and recalculating the natural frequency of each vibration mode of the guide vane blade of the axial flow pump, the acoustic standing wave frequency, and the ratio of each acoustic standing wave frequency to the natural frequency of each mode according to the mechanical parameters of the guide vane blade after the assumed cut off; a first determination subunit for taking the first length as the target length if the ratio is greater than a preset threshold; a second calculation subunit for recalculating the first length as the target length if the ratio is greater than a preset threshold; and a second calculation subunit for recalculating the first length as the target length if the ratio is greater than a preset threshold. If the ratio is less than a preset threshold, the assumed resection length is increased to a second length, and the natural frequencies and acoustic standing wave frequencies of each vibration mode of the guide vane of the axial flow pump, as well as the ratios of each acoustic standing wave frequency to the natural frequency of each mode are recalculated based on the mechanical parameters of the guide vane blade assumed to be resected; a second determination subunit is used to use the second length as the target length if the ratio is greater than the preset threshold; if the ratio is less than the preset threshold, the assumed resection length is increased to a third length, the natural frequencies, acoustic standing wave frequencies and the ratio are recalculated, and the target length is determined based on the ratio.

[0038] The fourth aspect of this specification provides a design device for an axial flow pump, comprising: a second calculation unit, for calculating the natural frequencies of each vibration mode of the guide vane of the axial flow pump according to the proposed mechanical parameters of the axial flow pump when designing the guide vane blades of the axial flow pump; a third calculation unit, for calculating the acoustic standing wave frequency on the guide vane blades under the working conditions of the axial flow pump according to the proposed mechanical parameters of the axial flow pump; an adjustment unit, for adjusting the proposed mechanical parameters or materials of the guide vane blades until the ratio of the acoustic standing wave frequency to the natural frequency of each mode reaches a preset threshold if the ratio of the acoustic standing wave frequency to the natural frequency of one of the modes is less than a preset threshold, and using the proposed mechanical parameters that make the ratio reach the preset threshold as the production basis of the axial flow pump.

[0039] In some embodiments, the acoustic standing wave frequency of the guide vane blade under the operating conditions of the axial flow pump is calculated by the following formula:

[0040] When the extended length of the guide vane is equal to half the wavelength of the standing wave,

[0041] When the extended length of the guide vane is equal to the wavelength of the standing wave,

[0042] When the expanded length of the guide vane is equal to 1.5 times the wavelength of the standing wave,

[0043] Among them, f0 is the frequency of the acoustic standing wave, c is the speed of sound propagation in water, and L is the expanded length of the guide vane.

[0044] In some embodiments, the value of the preset threshold is greater than 1.1.

[0045] The fifth aspect of this specification provides an electronic device, comprising: a memory and a processor, wherein the processor and the memory are communicatively connected to each other, the memory stores computer instructions, and the processor implements the vibration processing method of the axial flow pump described in any one of the first aspect or any one of the second aspect by executing the computer instructions.

[0046] A sixth aspect of this specification provides a computer storage medium, which stores computer program instructions. When the computer program instructions are executed by a processor, the vibration processing method of the axial flow pump described in any one of the first aspect or any one of the second aspect is implemented.

[0047] A seventh aspect of this specification provides a computer program product, comprising a computer program, which, when executed by a processor, implements the vibration processing method for an axial flow pump as described in any one of the first aspect or any one of the second aspect.

[0048] The vibration processing and design method, device and electronic equipment of the axial flow pump provided in this specification are based on the discovery that "high-frequency vibration comes from the resonance of the guide vane or the pump body, and the excitation source of the vibration comes from the standing wave inside the guide vane". A vibration processing method for the axial flow pump is proposed. The method includes: obtaining the natural frequency of each vibration mode of the guide vane blade of the axial flow pump; calculating the acoustic standing wave frequency on the guide vane blade under the working conditions of the axial flow pump; if there is a ratio of the acoustic standing wave frequency to the natural frequency of one of the modes is less than a preset threshold, then changing the mechanical parameters of the guide vane blade to change the natural frequency of the guide vane blade, for example, by cutting off part of the length of the guide vane blade, which can increase the offset rate between the acoustic standing wave frequency and the natural frequency of the guide vane blade, thereby avoiding resonance; it can also reduce the amplitude of the hydraulic excitation caused by the close distance between the impeller and the guide vane, thereby reducing the vibration response of the blade.

[0049] The vibration processing and design method, device and electronic equipment of the axial flow pump provided in this specification calculate the natural frequency, acoustic standing wave frequency and comparison value of each mode of the guide vane blade in the design stage of the axial flow pump, and adjust the mechanical parameters of the guide vane blade until the ratio of the acoustic standing wave frequency to the natural frequency of each mode reaches the preset threshold when the ratio is less than the preset threshold. This can make the stagger rate between the natural frequency of each mode of the guide vane blade and the acoustic standing wave frequency reach the preset threshold, thereby avoiding resonance and solving the high-frequency vibration and noise problems of the axial flow pump from the design link. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the accompanying drawings needed to be used in the description of the embodiments or the prior art will be briefly introduced. Obviously, the accompanying drawings in the following description only represent some embodiments described in the present application, and for those skilled in the art, other drawings can also be obtained from these drawings without any creative effort.

[0051] Figure 1 Structure diagram of axial flow pump;

[0052] Figure 2 Structure diagram of standing wave in a pipe with both ends closed;

[0053] Figure 3 Structure diagram of standing wave in a pipe with both ends open;

[0054] Figure 4 Structure diagram of standing wave in a pipe with one end open and the other end closed;

[0055] Figure 5 Vibration spectrum diagram of an experimental axial flow pump in a high-frequency vibration state;

[0056] Figure 6 Structure diagram of guide vane knocking experiment;

[0057] Figure 7 Structure diagram of selected knocking point and detection point in the guide vane knocking experiment;

[0058] Figure 8 Spectrum diagram of the first three order natural frequencies of the experimental axial flow pump determined through the knocking experiment;

[0059] Figure 9 Structure diagram of C-F-C-F structure model of guide vane blade;

[0060] Figure 10 Structure diagram of various sizes of guide vane;

[0061] Figure 11 Structure diagram of the value mode of frequency parameters used in the double-symmetry mode of C-F-C-F rectangular plate;

[0062] Figure 12 Structure diagram of the value mode of frequency parameters used in the symmetry-antisymmetry mode of C-F-C-F rectangular plate;

[0063] Figure 13 Flowchart of a vibration processing method of an axial flow pump provided in the present specification;

[0064] Figure 14 Flowchart of a method for determining a target length to be removed on a guide vane blade;

[0065] Figure 15 A cutting diagram of a guide vane of an axial flow pump;

[0066] Figure 16 A cross-sectional diagram of a guide vane before and after cutting; Figure 15

[0067] Figure 17 Another cross-sectional diagram of a guide vane before and after cutting; Figure 15

[0068] Figure 18 Still another cross-sectional diagram of a guide vane before and after cutting; Figure 15

[0069] A flow diagram of another design method of an axial flow pump provided in the present specification; Figure 19

[0070] A principle block diagram of a vibration processing device of an axial flow pump provided in the present specification; Figure 20

[0071] A principle block diagram of another design device of an axial flow pump provided in the present specification; Figure 21

[0072] A principle block diagram of an electronic device provided in the present specification. Figure 22 DETAILED DESCRIPTION

[0073] In order to make personnel in the technical field better understand the technical solutions in the present application, the technical solutions in the present application will be clearly and completely described in the present application embodiments in combination with the drawings in the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor should belong to the protection scope of the present application.

[0074] The impeller diameter of the axial flow pump is large (the impeller diameter of a medium-sized axial flow pump is between 300-1600 mm, and the impeller diameter of a large-sized axial flow pump is more than 1600 mm), and the blade of the medium-sized and large-sized axial flow pump is adjustable. The number of the blades of the axial flow pump is small (2-6 pieces), and the blade is in the form of an airfoil and has a large twist angle. The blade of the axial flow pump is relatively large (the length of the blade of a small-sized axial flow pump is usually about several hundred millimeters, and the width is several tens of millimeters to several hundred millimeters, the length of the blade of a large-sized axial flow pump can be more than 1 meter, even several meters, and the width can also reach several hundred millimeters). The impeller and the guide vane are designed to facilitate large-scale manufacturing.

[0075] ​​​Typically, the vibration frequency of an axial flow pump is between 1 and 5 kHz. However, the inventors have discovered that high-speed axial flow pumps sometimes exhibit abnormally high-frequency vibration and noise. Pumps driven by motors with four or more poles are at risk of exceeding vibration standards, especially annular tube axial flow pumps used in the petrochemical industry.

[0076] The vibration frequency range of the existing pump body is conventionally 1 to 5 kHz. In order to find out the cause of high-frequency vibration, the inventors put forward a lot of conjectures and conducted experimental verification.

[0077] One of the inventors' conjectures is that the high-frequency vibration originates from the resonance of the guide vanes or the pump body, and the excitation source of the vibration comes from the standing waves inside the guide vanes.

[0078] The following is a brief introduction to standing waves. When a wave encounters an obstacle or a dielectric interface during propagation, it is reflected. The superposition of the incident and reflected waves forms a standing wave. The core of a standing wave is the mutual interference of the incident and reflected waves, which ultimately leads to a fixed distribution of vibration intensity (nodes and antinodes) in the medium. The condition for the generation of standing waves is that the distance between the sound source and the reflecting surface and the wavelength form a certain integer ratio. The lowest frequency that meets this condition is when the distance between the sound source and the reflecting surface is equal to half the wavelength. Standing waves can also form when the distance between the sound wave and the reflecting surface is an integer multiple of half the wavelength. Generally, we only need to focus on the distance between the sound wave and the reflecting surface being equal to 1 times (i.e., λ / 2), 2 times (λ), and 3 times (3λ / 2) the half wavelength. In the case of other integer multiples, the wave energy is relatively low and generally does not cause high-frequency vibration issues.

[0079] The inventor studied the standing waves in the pipe and found that: for a pipe with both ends open or closed, when the pipe length is equal to half the wavelength of the sound or an integer multiple of half the wavelength, a standing wave will be formed, such as Figure 2 and Figure 3 As shown; for a pipe with one end open and the other end closed, when the pipe length is 1 / 4 wavelength of the sound or an integer multiple of 1 / 4 wavelength, a standing wave will be formed, such as Figure 4 shown.

[0080] The following example uses an axial flow pump application scenario to calculate the standing wave frequency that can cause resonance. Assume the water temperature is 32°C, the speed of sound in water is c = 1520 m / s, and the extended length of the guide vanes of the experimental axial flow pump is L = 262 mm. If the standing wave wavelength λ is such that L = λ / 2, then λ = 0.262 × 2 = 0.54 m, and the standing wave frequency f0 = c / λ = 1520 / 0.524 = 2900 Hz.

[0081] Similarly, if the standing wave wavelength λ makes L=λ, the standing wave frequency f0=5800 Hz can be calculated; if the standing wave wavelength λ makes L=3λ / 2, the standing wave frequency f0=8702 Hz can be calculated.

[0082] If the above hypothesis that "high-frequency vibration originates from the resonance of the guide vane or the pump body, and the vibration excitation source comes from the standing wave inside the guide vane" is true, then the axial flow pump is very likely to produce high-frequency vibration and noise problems at frequencies of 2900Hz, 5800Hz, and 8702Hz.

[0083] Figure 5 This is a vibration spectrum of an experimental axial flow pump under high-frequency vibration. The spectrum shows high vibration amplitudes near 1180Hz, 2892Hz, and 3067Hz, respectively. The frequencies of 2892Hz and 3067Hz are very close to the calculated standing wave frequency of 2900Hz. This confirms that the standing wave frequency and high-frequency vibration frequency are consistent with the above hypothesis.

[0084] So, is the high-frequency vibration caused by resonance caused by standing waves? This requires further verification to determine whether the natural frequency of the blades is close to the standing wave frequency. To this end, the inventors used guide vane tapping experiments and theoretical calculations to verify this.

[0085] 1. Guide vane knocking test

[0086] The guide vane knock test of an axial flow pump can be used to detect dynamic characteristics such as the guide vane's natural frequency, thereby preventing problems such as resonance during operation. Specifically, appropriate knock and test points are selected based on the guide vane's structural characteristics and actual operating conditions. Testing equipment such as accelerometers or strain gauges are then installed at the selected test points to collect the guide vane's vibration response signals under the knock. Figure 6 Schematic diagram of the guide vane knocking experiment.

[0087] Usually, multiple points are selected at different parts of the guide vane, such as the edge and center of the blade, for tapping tests to fully understand the vibration characteristics of the guide vane. Figure 7 Schematic diagram of the knocking points and detection points selected for the guide vane knocking test.

[0088] Verification experiment in Figure 7 The detection equipment is installed at the position shown in 6, and the positions shown in 1-5 and 7-15 are struck respectively. While striking, the detection equipment collects the vibration response signal, and the hammer force is set to 5000N.

[0089] For the test results, the frequency analysis range is set to within 6.3kHz, the frequency resolution is 400 lines, and the acceleration response is 20g (where g is the acceleration of gravity). This can be obtained as follows: Figure 8 The first three natural frequency spectra are shown in Figure 2. Figure 8It can be seen that the first-order natural frequency of the guide vane is 2998 Hz, the second-order natural frequency is 3288 Hz, and the third-order natural frequency is 4752 Hz.

[0090] 2. Theoretical Calculation

[0091] The guide vane can be approximately regarded as a rectangular flat plate with both ends well supported and fixed, and the inlet and outlet ends remaining free (without additional rigid constraints), such as Figure 6 As shown, the flow direction of the fluid is shown by the arrow. g1 and g2 indicate the fixed ends, which are the parts connected to the guide vane hub and the cover plate; z1 indicates the inlet end, z2 indicates the outlet end, and z1 and z2 indicate the free ends.

[0092] like Figure 10 As shown, or as Figure 7 and Figure 15 As shown, the top view shape of the guide vane is similar to a curved rectangle with slightly varying widths; Figure 15 、 Figure 16 、 Figure 17 、 Figure 18 It can be seen that the cross-section of the guide vane along the y-axis direction is an arc-shaped structure, the thickness of the main arc area remains uniform, and the thickness shows a gradually decreasing trend towards one end.

[0093] The guide vane can be viewed as a rectangular plate, and its vibration mode is represented by the CFCF mode. C stands for Clamped, which refers to the fixed side of the rectangular plate; F stands for Free, which refers to the free side of the rectangular plate. Figure 9 The four lowest nodal modes of the CFCF vibration modes of the rectangular plate are given. Figure 9 (a) is the first symmetric-symmetric mode, indicating that the shape and material of the rectangular plate make the vibration patterns of the rectangular plate in the x-axis and y-axis directions symmetrical, and the vibration energy distribution is relatively uniform; Figure 9 (b) is the first symmetric-antisymmetric mode, which means that the rectangular plate is symmetric along the x-axis and asymmetric along the y-axis. Figure 9 (c) is the first antisymmetric-symmetric mode, which means that the rectangular plate is symmetric along the y-axis and asymmetric along the x-axis; Figure 9 (d) is the first antisymmetric-antisymmetric mode, indicating that the rectangular plate is asymmetric along both the x-axis and the y-axis.

[0094] like Figure 10 and Figure 15As shown in the figure, the thickness of the guide vane along the y-axis is uneven, showing an asymmetric characteristic, while along the x-axis it is approximately a trapezoid, and its asymmetry has little effect on the vibration mode, so it can be considered that the guide vane is symmetrical along the x-axis. Figure 9 For the cases shown in (a) and (c), the β value can be determined by using the frequency parameter value selection method corresponding to these two cases.

[0095] Specifically, the dimensions of the guide vane blades are expressed as follows: the average width of the free end section of the guide vane is a, the length of the fixed end of the guide vane parallel to the liquid flow direction is b, the thickness of the guide vane steel plate is h, E is the elastic modulus of the guide vane steel plate, v is the Poisson's ratio of the guide vane steel plate, ρ is the material density of the guide vane steel plate, β is the frequency parameter, then the guide vane width-to-length ratio is a / b. Figure 10 The following diagrams show various guide vane dimensions. The left side shows the expanded guide vane blade, with the shading marking the fixed end of the guide vane. The right side shows a side view of the guide vane blade. The specific values ​​for each parameter are shown in Table 1 below.

[0096] Table 1 Main dimensions of guide vanes

[0097] a b a / b h D ρ Remark Original pump design 0.139 0.230 0.6 0.01 19230 78 Calculate β according to a / b=0.6

[0098] The calculation formulas for the guide vane steel plate bending strength D and natural frequency F are as follows:

[0099]

[0100] Figure 10 The different settings of the two coordinate systems in the guide vane can correspond to Figure 9 At least two modes in the equation: bisymmetric mode and symmetric-antisymmetric mode.

[0101] Figure 11 is the bisymmetric mode of the CFCF rectangular plate (corresponding to Figure 9 The frequency parameters used in (a) Schematic diagram of the value selection method, including the values ​​of the frequency parameter β of each vibration mode corresponding to each value of the aspect ratio a / b. Figure 12 is the symmetric-antisymmetric mode of the CFCF rectangular plate (corresponding to Figure 9 The frequency parameters used in (c) Schematic diagram of how to obtain the value of .

[0102] Calculate a / b=0.6, from Figure 11 and Figure 12 Find the values ​​corresponding to the width-to-length ratio of 0.6. The results of calculating the natural frequency based on the values ​​are shown in Table 2 below. Figure 11 and Figure 12 There are a total of 7 frequency parameter β values.

[0103] Table 2 Natural frequencies calculated based on all frequency parameters β corresponding to a / b

[0104]

[0105]

[0106] above Figure 9 The lowest nodal modes of the four symmetry types in the CFCF vibration shapes of the rectangular plate shown, and Figure 11 and Figure 12 The data in the table shown are from a book titled "VIBRATION OF PLATES" published by NASA in the 20th century.

[0107] according to Figure 8 The first-order natural frequency of 2998Hz, the second-order natural frequency of 3288Hz, and the third-order natural frequency of 4752Hz determined by the knocking experiment are very close to the natural frequencies obtained by theoretical calculation. Figure 5 The vibration and noise frequencies of the experimental axial flow pump under high-frequency vibration conditions are approximately around 2880-3100 Hz. The calculated frequency of the guide vane acoustic standing wave is 2900 Hz. In other words, the guide vane acoustic standing wave frequency is very close to the first-order natural frequency of the guide vane blades, and is also very close to the actual vibration frequency of the axial flow pump under high-frequency vibration conditions. Therefore, based on the above data, it can be considered that the inventor's above-mentioned conjecture that "high-frequency vibration originates from the resonance of the guide vanes or pump body, and the vibration excitation source comes from the standing waves inside the guide vanes" is correct. Although the guide vane acoustic standing wave frequency is lower than the first-order natural frequency of the guide vanes, the offset rate is within 10%, thus causing resonance. Since there is no vibration source at the second-order and third-order natural frequencies of the guide vanes, no resonance is excited. In addition, since the energy of the second-order and higher natural frequencies is much smaller than that of the first-order natural frequency, the influence of the second-order and higher natural frequencies can be ignored.

[0108] It should be noted that the natural frequency orders (or vibration modes) corresponding to the same serial number in Table 2 above may be different. For example, the natural frequency orders (or vibration modes) corresponding to serial numbers 2 and 3 are different. This is because the "calculated natural frequencies" in the third column of Table 2 are calculated based on the first symmetric-symmetric mode and the first antisymmetric-symmetric mode of the guide vane under ideal conditions. However, actual guide vanes are not in ideal conditions for these modes. Part of the actual guide vane may approximate the first symmetric-symmetric mode under ideal conditions, while another part approximates the first antisymmetric-symmetric mode under ideal conditions.

[0109] In addition, it can also be seen from Table 2 that the selection of the knocking position also affects the natural frequency measured in the knocking experiment.

[0110] However, the above error does not affect the effectiveness of the technical solutions provided in the specification. The data in Table 2 in the specification is only to verify the general relationship between the high-frequency vibration and noise of the axial flow pump, the natural frequency of the guide vane blade, and the acoustic standing wave frequency of the guide vane blade, and to solve the problem of high-frequency vibration and noise of the axial flow pump based on the general relationship. When solving the problem of high-frequency vibration and noise, the acoustic standing wave frequency on the guide vane blade is set to be greatly staggered with the natural frequency of the guide vane blade, so the specification does not need to accurately determine the natural frequency of the guide vane blade. In practice, it is found that the method provided in the specification can effectively solve the problem of high-frequency vibration and noise of the axial flow pump. In fact, due to the complex structure and working state of the guide vane blade, the existing technology cannot accurately determine the natural frequency of the guide vane blade, which is one of the key factors why the industry is difficult to solve the problem of high-frequency vibration and noise of the axial flow pump.

[0111] In addition, it should be noted that most of the pump blades are short and small or the impeller passing frequency is small, and such a pump will not appear high-frequency resonance and noise when working. The conventional axial flow pump speed is usually 500-1500 r / min, and the high-frequency axial flow pump speed can reach 3000-10000 r / min (or even higher), and the corresponding operating frequency is 50-1000 Hz. Only under such working conditions of the axial flow pump, the high-frequency resonance and noise to be solved in the specification will occur.

[0112] Based on the above research, the specification provides a vibration processing method for an axial flow pump to solve the problem of high-frequency vibration and noise of the axial flow pump. As shown in Figure 13 The method comprises S110-S130.

[0113] S110: Obtain the natural frequency of each vibration mode of the guide vane blade of the axial flow pump.

[0114] The "natural frequency of each vibration mode" can be the first-order natural frequency, the second-order natural frequency, and the third-order natural frequency, that is, the "each vibration mode" refers to each order of the natural frequency.

[0115] In actual use, the specific natural frequencies of several vibration modes that need to be calculated can be determined according to the high-frequency vibration frequency of the axial flow pump under the working condition of generating high-frequency vibration. Some natural frequencies of vibration modes that differ slightly from the actual high-frequency vibration frequency of the axial flow pump can be selected. The higher-order natural frequency differs greatly from the high-frequency vibration frequency of the axial flow pump and can be ignored.

[0116] The natural frequency of the guide vane blade of the axial flow pump can be calculated by the following formula:

[0117] Wherein, F is the natural frequency; β is the frequency parameter, which is determined according to the width-length ratio of the guide vane blade; a is the width of the free end section of the guide vane blade; D is the bending strength of the material (i.e. steel plate) of the guide vane blade; ρ is the material density of the guide vane blade; h is the thickness of the guide vane blade; E is the elastic modulus of the guide vane blade; and v is the Poisson's ratio of the guide vane blade.

[0118] In the case where the width of the guide vane blade varies, the width of the free end section of the guide vane blade can be calculated by taking the average width, or the maximum or minimum width. In the case where the thickness of the guide vane blade varies, the thickness h of the guide vane blade can be calculated by taking the average thickness, or the maximum or minimum thickness.

[0119] In the case of calculating different vibration modes, the frequency parameter corresponding to the same width-length ratio has different values.

[0120] The natural frequency of the guide vane blade of the axial flow pump can also be obtained by knocking experiment, and can also be obtained by simulation.

[0121] S120: Calculate the acoustic standing wave frequency on the guide vane blade under the working condition of the axial flow pump.

[0122] The working condition of the axial flow pump includes water temperature, which affects the propagation speed of sound in water, and the two are in a non-linear positive correlation, that is, within a certain temperature range, the water temperature rises, and the sound speed increases.

[0123] The acoustic standing wave frequency of the guide vane blade under the working condition of the axial flow pump can be calculated by the following formula:

[0124] In the case where the development length of the guide vane blade is equal to half of the standing wave wavelength,

[0125] In the case where the development length of the guide vane blade is equal to the standing wave wavelength,

[0126] In the case where the development length of the guide vane blade is equal to 1.5 times the standing wave wavelength,

[0127] Wherein, f0 is the acoustic standing wave frequency, c is the propagation speed of sound in water, and L is the development length of the guide vane blade.

[0128] S120 can be calculated according to the above three calculation formulas respectively to calculate the acoustic standing wave frequency, so as to judge whether to cut off the guide vane blade.

[0129] S130: If the ratio of the frequency of the acoustic standing wave to the natural frequency of one of the modes is smaller than a preset threshold, the mechanical parameters of the guide vane are changed to change the natural frequency of the guide vane.

[0130] The preset threshold value is greater than 1.1. For example, the preset threshold value may be 1.11, 1.15, 1.2, 1.25, 1.3, 1.35, 1.4, etc.

[0131] In this specification, “mechanical parameters of the guide vane” refer to parameters that can affect the shape of the guide vane, such as the guide vane length, the guide vane curvature, the protrusion on the guide vane, etc.

[0132] The natural frequency of the guide vane can be changed by adding a counterweight to the guide vane or by cutting off part of the length of the guide vane.

[0133] Part of the guide vane length can be cut off from the inlet end of the guide vane blade. Figure 14 As shown, the target length to be cut off on the guide vane blade can be determined through the following S131 to S136.

[0134] S131: Acquire mechanical parameters of the guide vanes of the axial flow pump before they are removed.

[0135] S132: Assuming that a first length is cut off from the inlet end of the guide vane blade, recalculate the natural frequency of each vibration mode of the guide vane blade of the axial flow pump, the acoustic standing wave frequency, and the ratio of each acoustic standing wave frequency to the natural frequency of each mode based on the mechanical parameters of the guide vane blade after the assumed cut-off.

[0136] S133: If the ratio is greater than a preset threshold, the first length is used as the target length.

[0137] S134: If the ratio is less than a preset threshold, the assumed cut-off length is increased to a second length, and the natural frequencies and acoustic standing wave frequencies of each vibration mode of the guide vane of the axial flow pump, as well as the ratios of each acoustic standing wave frequency to the natural frequency of each mode, are recalculated based on the mechanical parameters of the guide vane blade after the assumed cut-off.

[0138] S135: If the ratio is greater than a preset threshold, the second length is used as the target length.

[0139] S136: If the ratio is less than a preset threshold, the assumed resection length is increased to a third length, the natural frequency, the acoustic standing wave frequency and the ratio are recalculated, and the target length is determined based on the ratio.

[0140] The above steps S131 to S136 first determine the length of the guide vane to be cut, and then calculate whether the ratio of the natural frequency of the guide vane to the acoustic standing wave frequency after cutting off the length is greater than a preset threshold. If the ratio is greater than the preset threshold, it means that the staggered ratio of the natural frequency of each order of the guide vane and the acoustic standing wave frequency has met the requirements, and cutting off the guide vane of this length can avoid the occurrence of high-frequency resonance and noise in the axial flow pump. If the ratio is less than the preset threshold, it means that the staggered ratio of the natural frequency of each order of the guide vane and the acoustic standing wave frequency has not met the requirements. Even if the guide vane of this length is cut off, the axial flow pump will still experience high-frequency resonance and noise. To this end, it is necessary to further increase the cutting length, recalculate and judge, and repeat this cycle until the calculated ratio is greater than the preset threshold and the target length is determined. The amplitude of the cutting length can be set to be smaller each time to minimize the length of the blade cut.

[0141] Figure 15 This is a schematic diagram of cutting a guide vane blade of an axial flow pump. The lower shaded part represents the guide vane hub, the upper shaded part represents the inner wall of the pump body, the straight lines represented by circle 1, circle 2, and circle 3 are the outlet end contour lines of the guide vane blade, and the straight lines represented by circle 1', circle 2', and circle 3' are the inlet end contour lines of the guide vane blade before cutting. Figure 15 The figure also shows the contour line of the inlet end after cutting. Figure 15 The cutting method shown is: take the contact point between the guide vane inlet contour line and the inner wall of the pump body as the first starting point, and determine the distance m from the first starting point on the contact line between the guide vane blade and the inner wall of the pump body (m is a positive number, Figure 15 The contact point between the guide vane inlet end contour line and the guide vane hub is taken as the second starting point, and a distance n from the second starting point is determined on the contact line between the guide vane blade and the guide vane hub (n is 0 or a positive number, Figure 15 where n is 10 mm); cut the following three line segments: a first line segment from the first starting point to position M, a second line segment from the second starting point to position N, and a third line segment from position M to position N.

[0142] Figure 16 for Figure 15 The schematic cross-sectional view of the guide vane before and after cutting is shown. Figure 15 Schematic diagram of the cross section indicated by circle 3 and circle 3'; Figure 17 for Figure 15 Another cross-sectional schematic diagram of the guide vane before and after being cut is shown, specifically Figure 15 Schematic diagram of the cross section indicated by circle 2 and circle 2'. After cutting the first, second, and third line segments, the cross section indicated by circle 2 and circle 2' is cut off by 16 mm. Figure 18 for Figure 15 Another cross-sectional diagram of the guide vane before and after being cut is shown, specifically Figure 15 Schematic diagram of the cross section indicated by the circle 1 and the circle 1'.

[0143] exist Figure 16 、 Figure 17 、 Figure 18 The 10 on the right side indicates the thickness of the guide vane, and the R and angle on the left side indicate the radian parameters of one end of the guide vane.

[0144] The vibration processing method of the axial flow pump provided in this specification is based on the discovery that "high-frequency vibration comes from the resonance of the guide vane or the pump body, and the excitation source of the vibration comes from the standing wave inside the guide vane". The method includes: calculating the natural frequency of each vibration mode of the guide vane blade of the axial flow pump; calculating the acoustic standing wave frequency on the guide vane blade under the working conditions of the axial flow pump; if there is a ratio of the acoustic standing wave frequency to the natural frequency of one of the modes is less than a preset threshold, then changing the mechanical parameters of the guide vane blade to change the natural frequency of the guide vane blade, for example, by cutting off part of the length of the guide vane blade, which can increase the offset rate between the acoustic standing wave frequency and the natural frequency of the guide vane blade, thereby avoiding resonance; it can also reduce the amplitude of the hydraulic excitation caused by the close distance between the impeller and the guide vane, thereby reducing the vibration response of the blade.

[0145] Based on the above research, this specification also provides a design method for an axial flow pump to solve the high-frequency vibration and noise problems of the axial flow pump from the design link of the axial flow pump. Figure 19 As shown, the method includes S210 to S230.

[0146] S210: When designing the guide vanes of the axial flow pump, the natural frequencies of the vibration modes of the guide vanes of the axial flow pump are calculated based on the proposed mechanical parameters of the axial flow pump.

[0147] S220: Calculating the acoustic standing wave frequency on the guide vane blade under the working condition of the axial flow pump based on the proposed mechanical parameters of the axial flow pump.

[0148] The working conditions of the axial flow pump include water temperature. Water temperature affects the speed of sound propagation in water. The two are nonlinearly positively correlated, that is, within a certain temperature range, the water temperature increases and the sound speed increases.

[0149] The acoustic standing wave frequency of the guide vane under the working conditions of the axial flow pump can be calculated by the following formula:

[0150] When the extended length of the guide vane is equal to half the wavelength of the standing wave,

[0151] When the extended length of the guide vane is equal to the wavelength of the standing wave,

[0152] When the expanded length of the guide vane is equal to 1.5 times the wavelength of the standing wave,

[0153] Among them, f0 is the frequency of the acoustic standing wave, c is the speed of sound propagation in water, and L is the expanded length of the guide vane.

[0154] S220 may be to calculate the acoustic standing wave frequencies respectively according to the above three calculation formulas, so as to determine whether to remove the guide vane blades.

[0155] S230: If the ratio of the frequency of the standing wave to the natural frequency of one of the modes is less than a preset threshold, the proposed mechanical parameters or material distribution of the guide vane are adjusted until the ratio of the frequency of the standing wave to the natural frequency of each mode reaches the preset threshold. The proposed mechanical parameters that make the ratio reach the preset threshold are used as the production basis of the axial flow pump.

[0156] The preset threshold value is greater than 1.1. For example, the preset threshold value may be 1.11, 1.15, 1.2, 1.25, 1.3, 1.35, 1.4, etc.

[0157] In some embodiments, adjusting the proposed mechanical parameter of the guide vane blade includes increasing or decreasing the size of the guide vane blade of the axial flow pump.

[0158] After the axial flow pump is put into use, the size of the guide vanes of the axial flow pump cannot usually be increased. During the design stage of the axial flow pump, the size of the guide vanes can usually be adjusted in the direction of increase or decrease.

[0159] In some cases, the natural frequencies of guide vanes vary depending on the material used. If the guide vanes are made of two materials, the natural frequencies may also vary depending on the material distribution within the guide vanes. "Adjusting the material of the guide vanes" can refer to adjusting the material itself or the material distribution.

[0160] The above S210 to S230 calculate the natural frequency of each mode of the guide vane, the acoustic standing wave frequency and the comparison value between the two during the design stage of the axial flow pump, and adjust the mechanical parameters of the guide vane until the ratio of the acoustic standing wave frequency to the natural frequency of each mode reaches the preset threshold when the ratio is less than the preset threshold. This can make the staggered rate between the natural frequency of each mode of the guide vane and the acoustic standing wave frequency reach the preset threshold, thereby avoiding resonance and solving the high-frequency vibration and noise problems of the axial flow pump from the design link.

[0161] This specification also provides a vibration processing device for an axial flow pump, which can be used to achieve Figure 13 The vibration treatment method of the axial flow pump is shown in FIG. Figure 20As shown, the device includes an acquisition unit 110 , a first calculation unit 120 and a processing unit 130 .

[0162] The acquisition unit 110 is used to acquire the natural frequencies of each vibration mode of the guide vane blade of the axial flow pump.

[0163] The first calculation unit 120 is used to calculate the acoustic standing wave frequency on the guide vane under the working condition of the axial flow pump according to the current mechanical parameters of the guide vane.

[0164] The processing unit 130 is configured to change the mechanical parameters of the guide vane to change the natural frequency of the guide vane if the ratio of the frequency of the acoustic standing wave to the natural frequency of one of the modes is smaller than a preset threshold.

[0165] In some embodiments, changing a mechanical parameter of the guide vane blade to change a natural frequency of the guide vane blade includes cutting off a portion of the length of the guide vane blade.

[0166] In some embodiments, the natural frequency of the guide vane of the axial flow pump is calculated using the following formula:

[0167] Wherein, F is the natural frequency; β is the frequency parameter, which is determined according to the width-to-length ratio of the guide vane. When calculating different vibration modes, the same width-to-length ratio corresponds to different frequency parameter values; a is the width of the free end section of the guide vane; ρ is the material density of the guide vane; h is the thickness of the guide vane, E is the elastic modulus of the guide vane, and v is the Poisson's ratio of the guide vane.

[0168] In some embodiments, the natural frequencies of each vibration mode of the guide vane of the axial flow pump are obtained through a knocking test.

[0169] In some embodiments, the acoustic standing wave frequency of the guide vane blade under the operating conditions of the axial flow pump is calculated by the following formula:

[0170] When the extended length of the guide vane is equal to half the wavelength of the standing wave,

[0171] When the extended length of the guide vane is equal to the wavelength of the standing wave,

[0172] When the expanded length of the guide vane is equal to 1.5 times the wavelength of the standing wave,

[0173] Among them, f0 is the frequency of the acoustic standing wave, c is the speed of sound propagation in water, and L is the expanded length of the guide vane.

[0174] In some embodiments, the value of the preset threshold is greater than 1.1.

[0175] In some embodiments, the processing unit includes an acquisition subunit, a first calculation subunit, a first determination subunit, a second calculation subunit, and a second determination subunit.

[0176] The acquisition subunit is used to acquire the mechanical parameters of the guide vanes of the axial flow pump before they are cut off.

[0177] The first calculation subunit is used to assume that a first length is cut off from the inlet end of the guide vane blade, and recalculate the natural frequency and acoustic standing wave frequency of each vibration mode of the guide vane blade of the axial flow pump according to the mechanical parameters of the guide vane blade after the assumed cut-off, as well as the ratio of each acoustic standing wave frequency to the natural frequency of each mode.

[0178] The first determining subunit is configured to use the first length as the target length if the ratio is greater than a preset threshold.

[0179] The second calculation subunit is used to increase the assumed resection length to a second length if the ratio is less than a preset threshold, and recalculate the natural frequencies and acoustic standing wave frequencies of each vibration mode of the guide vane of the axial flow pump according to the mechanical parameters of the guide vane after the assumed resection, as well as the ratios of each acoustic standing wave frequency to the natural frequency of each mode.

[0180] The second determining subunit is configured to use the second length as the target length if the ratio is greater than a preset threshold.

[0181] If the ratio is less than a preset threshold, the assumed resection length is increased to a third length, the natural frequency, the acoustic standing wave frequency and the ratio are recalculated, and the target length is determined based on the ratio.

[0182] This specification also provides a design device for an axial flow pump, which can be used to achieve Figure 19 The design method of the axial flow pump is shown in FIG. Figure 21 As shown, the apparatus includes a second calculating unit 210 , a third calculating unit 220 and an adjusting unit 230 .

[0183] The second calculation unit 210 is used to calculate the natural frequencies of each vibration mode of the guide vane of the axial flow pump according to the proposed mechanical parameters of the axial flow pump when designing the guide vane of the axial flow pump.

[0184] The third calculation unit 220 is configured to calculate the acoustic standing wave frequency on the guide vane blade under the working condition of the axial flow pump according to the proposed mechanical parameters of the axial flow pump.

[0185] The adjustment unit 230 is used to adjust the proposed mechanical parameters or materials of the guide vane until the ratio of the acoustic standing wave frequency to the natural frequency of each mode reaches the preset threshold if the ratio of the acoustic standing wave frequency to the natural frequency of one of the modes is less than a preset threshold. The proposed mechanical parameters that make the ratio reach the preset threshold are used as the production basis of the axial flow pump.

[0186] In some embodiments, adjusting the designed mechanical parameters of the guide vane blade includes increasing or decreasing the size of the guide vane blade of the axial flow pump.

[0187] In some embodiments, the acoustic standing wave frequency of the guide vane blade under the working condition of the axial flow pump is calculated by the following formula:

[0188] In the case where the development length of the guide vane blade is equal to half of the wavelength of the standing wave,

[0189] In the case where the development length of the guide vane blade is equal to the wavelength of the standing wave,

[0190] In the case where the development length of the guide vane blade is equal to 1.5 times of the wavelength of the standing wave,

[0191] Where f0 is the acoustic standing wave frequency, c is the propagation speed of sound in water, and L is the development length of the guide vane blade.

[0192] In some embodiments, the preset threshold value is greater than 1.1.

[0193] Embodiments of the present application also provide an electronic device, as shown in Figure 22 The electronic device can include a processor 2201 and a memory 2202, where the processor 2201 and the memory 2202 can be connected by a bus or other means, Figure 22 For example, by a bus connection.

[0194] The processor 2201 can be a central processing unit (CPU). The processor 2201 can also be other general-purpose processors, digital signal processors (DSPs), application specific integrated circuits (ASICs), field programmable gate arrays (FPGAs) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components, etc. chips, or combinations of the above various types of chips.

[0195] The memory 2202 as a non-transitory computer readable storage medium can be used to store non-transitory software programs, non-transitory computer executable programs and modules, such as the program instructions / modules of the vibration processing method of the axial flow pump in the embodiments of the present application (for example, Figure 20 The acquisition unit 110, the first calculation unit 120 and the processing unit 130 shown in Figure 21The processor 2201 executes various functional applications and data processing of the processor by running the non-transient software programs, instructions, and modules stored in the memory 2202, thereby implementing the vibration processing method for the axial flow pump in the above-mentioned method embodiment.

[0196] The memory 2202 may include a program storage area and a data storage area, wherein the program storage area may store an operating system and application programs required for at least one function; the data storage area may store data created by the processor 2201, etc. In addition, the memory 2202 may include a high-speed random access memory, and may also include a non-volatile memory, such as at least one disk storage device, a flash memory device, or other non-volatile solid-state storage device. In some embodiments, the memory 2202 may optionally include a memory remotely located relative to the processor 2201, and these remote memories may be connected to the processor 2201 via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0197] The one or more modules are stored in the memory 2202 and when executed by the processor 2201, perform the following steps: Figure 13 or Figure 19 The vibration treatment method of the axial flow pump in the illustrated embodiment.

[0198] The specific details of the above electronic device can be understood by referring to the corresponding descriptions and effects in the method embodiment, and will not be repeated here.

[0199] This specification also provides a computer storage medium, wherein the computer storage medium stores computer program instructions, and when the computer program instructions are executed by a processor, the steps of the above-mentioned vibration processing method for the axial flow pump are implemented.

[0200] This specification also provides a computer program product, which includes a computer program. When the computer program is executed by a processor, the steps of the vibration processing method of the axial flow pump are implemented.

[0201] Those skilled in the art will appreciate that all or part of the processes in the above-mentioned embodiments can be implemented by instructing the relevant hardware through a computer program. The program can be stored in a computer-readable storage medium. When the program is executed, it can include the processes of the embodiments of the above-mentioned methods. The storage medium can be a magnetic disk, an optical disk, a read-only memory (ROM), a random access memory (RAM), a flash memory, a hard disk drive (HDD), or a solid-state drive (SSD). The storage medium can also include a combination of the above-mentioned types of memory.

[0202] The various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on the differences from other embodiments.

[0203] The systems, devices, modules or units described in the above embodiments may be implemented by computer chips or entities, or by products with certain functions.

[0204] For the convenience of description, the above devices are described as being divided into various units according to their functions. Of course, when implementing this application, the functions of each unit can be implemented in the same or multiple software and / or hardware.

[0205] Through the description of the above embodiments, it can be seen that those skilled in the art can clearly understand that the present application can be implemented by means of software plus the necessary general hardware platform. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art, can be embodied in the form of a software product. The computer software product can be stored in a storage medium, such as ROM / RAM, a magnetic disk, an optical disk, etc., and includes a number of instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to execute certain parts of the methods of each embodiment of the present application.

[0206] The present application can be used in a wide variety of general-purpose or specialized computer system environments or configurations, such as personal computers, server computers, handheld or portable devices, tablet devices, multiprocessor systems, microprocessor-based systems, set-top boxes, programmable consumer electronics, network PCs, minicomputers, mainframe computers, and distributed computing environments that include any of the above.

[0207] The present application may be described in the general context of computer-executable instructions executed by a computer, such as program modules. Generally, program modules include routines, programs, objects, components, data structures, etc. that perform specific tasks or implement specific abstract data types. The present application may also be practiced in distributed computing environments where tasks are performed by remote processing devices connected through a communications network. In a distributed computing environment, program modules may be located in local and remote computer storage media, including storage devices.

[0208] Although the present application has been described through embodiments, those skilled in the art will appreciate that there are many modifications and variations to the present application without departing from the spirit of the present application. It is intended that the appended claims include these modifications and variations without departing from the spirit of the present application.

Claims

1. A vibration treatment method for an axial flow pump, characterized in that: include: Obtain the natural frequencies of each vibration mode of the guide vane of the axial flow pump; Calculate the acoustic standing wave frequency on the guide vane under the working condition of the axial flow pump based on the current mechanical parameters of the guide vane; If the ratio of the frequency of the acoustic standing wave to the natural frequency of one of the modes is smaller than a preset threshold, the mechanical parameters of the guide vane are changed to change the natural frequency of the guide vane.

2. The method according to claim 1, characterized in that Changing the mechanical parameters of the guide vane to change the natural frequency of the guide vane includes: cutting off a portion of the length of the guide vane.

3. The method according to claim 1, characterized in that The natural frequency of the guide vane of the axial flow pump is calculated by the following formula: Wherein, F is the natural frequency; β is the frequency parameter, which is determined according to the width-to-length ratio of the guide vane. When calculating different vibration modes, the same width-to-length ratio corresponds to different frequency parameter values; a is the width of the free end section of the guide vane; D is the bending strength of the guide vane material; ρ is the material density of the guide vane; h is the thickness of the guide vane, E is the elastic modulus of the guide vane, and v is the Poisson's ratio of the guide vane.

4. The method according to claim 1, wherein The natural frequencies of each vibration mode of the guide vane of the axial flow pump are obtained through the knocking experiment.

5. The method according to claim 1, wherein The acoustic standing wave frequency of the guide vane under the working conditions of the axial flow pump is calculated by the following formula: When the extended length of the guide vane is equal to half the wavelength of the standing wave, When the extended length of the guide vane is equal to the wavelength of the standing wave, When the expanded length of the guide vane is equal to 1.5 times the wavelength of the standing wave, Among them, f0 is the frequency of the acoustic standing wave, c is the speed of sound propagation in water, and L is the expanded length of the guide vane.

6. The method according to claim 1, characterized in that The preset threshold value is greater than 1.

1.

7. The method according to claim 2, characterized in that The target length to be cut off on the guide vane is determined by: Obtain the mechanical parameters of the guide vanes of the axial flow pump before they are cut off; Assuming that a first length is cut off from the inlet end of the guide vane, recalculating the natural frequencies of each vibration mode and the acoustic standing wave frequencies of the guide vane of the axial flow pump, as well as the ratios of each acoustic standing wave frequency to the natural frequency of each mode, based on the mechanical parameters of the guide vane after the assumed cut-off; If the ratio is greater than a preset threshold, the first length is used as the target length; If the ratio is less than a preset threshold, the assumed resection length is increased to a second length, and the natural frequencies of each vibration mode of the guide vane of the axial flow pump, the acoustic standing wave frequencies, and the ratios of each acoustic standing wave frequency to the natural frequency of each mode are recalculated based on the mechanical parameters of the guide vane after the assumed resection; If the ratio is greater than a preset threshold, the second length is used as the target length; If the ratio is less than a preset threshold, the assumed resection length is increased to a third length, the natural frequency, the acoustic standing wave frequency and the ratio are recalculated, and the target length is determined based on the ratio.

8. A design method for an axial flow pump, characterized in that: include; When designing the guide vanes of an axial flow pump, the natural frequencies of each vibration mode of the guide vanes of the axial flow pump are calculated based on the proposed mechanical parameters of the axial flow pump; Calculate the acoustic standing wave frequency on the guide vane under the working condition of the axial flow pump based on the proposed mechanical parameters of the axial flow pump; If the ratio of the frequency of the standing wave to the natural frequency of one of the modes is less than a preset threshold, the proposed mechanical parameters or material of the guide vane blades are adjusted until the ratio of the frequency of the standing wave to the natural frequency of each mode reaches the preset threshold. The proposed mechanical parameters that make the ratio reach the preset threshold will be used as the production basis for the axial flow pump.

9. The method according to claim 8, characterized in that Adjusting the proposed mechanical parameters of the guide vane blades includes increasing or decreasing the size of the guide vane blades of the axial flow pump.

10. The method according to claim 8, characterized in that The acoustic standing wave frequency of the guide vane under the working conditions of the axial flow pump is calculated by the following formula: When the extended length of the guide vane is equal to half the wavelength of the standing wave, When the extended length of the guide vane is equal to the wavelength of the standing wave, When the expanded length of the guide vane is equal to 1.5 times the wavelength of the standing wave, Among them, f0 is the frequency of the acoustic standing wave, c is the speed of sound in water, and L is the expanded length of the guide vane.

11. The method according to claim 8, characterized in that The preset threshold value is greater than 1.

1.

12. A vibration treatment device for an axial flow pump, characterized in that: include: An acquisition unit, configured to acquire the natural frequencies of each vibration mode of the guide vane of the axial flow pump; The first calculation unit is used to calculate the acoustic standing wave frequency on the guide vane under the working condition of the axial flow pump according to the current mechanical parameters of the guide vane; The processing unit is configured to change a mechanical parameter of the guide vane to change the natural frequency of the guide vane if a ratio of a frequency of the acoustic standing wave to a natural frequency of one of the modes is smaller than a preset threshold.

13. A design device for an axial flow pump, characterized in that: include: The second calculation unit is used to calculate the natural frequencies of each vibration mode of the guide vane of the axial flow pump according to the proposed mechanical parameters of the axial flow pump when designing the guide vane of the axial flow pump; a third calculation unit for calculating the acoustic standing wave frequency on the guide vane blade under the working condition of the axial flow pump according to the proposed mechanical parameters of the axial flow pump; The adjustment unit is used to adjust the proposed mechanical parameters or materials of the guide vane until the ratio of the acoustic standing wave frequency to the natural frequency of each mode reaches the preset threshold if the ratio of the acoustic standing wave frequency to the natural frequency of one of the modes is less than a preset threshold, and the proposed mechanical parameters that make the ratio reach the preset threshold are used as the production basis of the axial flow pump.

14. An electronic device, characterized in that: include: A memory and a processor, wherein the processor and the memory are communicatively connected to each other, computer instructions are stored in the memory, and the processor implements the vibration processing method of the axial flow pump according to any one of claims 1 to 11 by executing the computer instructions.

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