A design method for a water pump volute for vibration reduction

Abstract

This invention relates to the field of hydraulic machinery in water conservancy engineering, specifically a design method for a water pump volute for vibration reduction; it includes: an impeller, a volute, and an elastic material wall surface; the pressure chamber is an important component in the operation of the water pump, which helps to collect the fluid pressed out from the impeller, reduce the flow velocity, recover some energy, and allow the fluid to flow smoothly out of the pump; during the operation of the water pump, the fluid flows out through the rotating impeller, impacting and squeezing the volute wall surface. The interaction between the rotating impeller and the stationary volute wall surface, i.e., dynamic-static interference, will generate pressure pulsations. Large pressure pulsations will lead to vibration noise, reduce the operating efficiency of the water pump, and even affect the safe and stable operation of the pump device; this invention achieves the purpose of water pump vibration reduction by processing the volute wall surface into an elastic material wall surface, buffering the pressure pulsations caused by dynamic-static interference, and has the advantages of novel structure, energy saving and efficiency improvement, and ease of design.

Description

Technical Field

[0001] This invention relates to the field of hydraulic machinery in water conservancy engineering, specifically to a design method for a water pump volute for vibration reduction. Background Technology

[0002] During pump operation, fluid flows out through the rotating impeller, impacting and compressing the volute casing wall. The interaction between the rotating impeller and the stationary volute casing wall, known as dynamic-static interference, generates pressure pulsations. Large pressure pulsations can lead to vibration noise, reduced pump efficiency, and even affect the safe and stable operation of the pump system. This invention provides a pump volute casing design method for vibration reduction to address this problem. Summary of the Invention

[0003] The purpose of this invention is to provide a design method for a water pump volute for vibration reduction, in order to solve the problems mentioned in the background art.

[0004] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0005] The objective of this invention is achieved as follows: First, a modification scheme is determined. A modification area is selected as an example, and the vibration acceleration amplitude at the corresponding point on the outer wall of the volute is obtained. By setting a target vibration acceleration amplitude, the relevant dimensions of the modification area are calculated, and thus the volume of the modification area is determined. The strength of the elastic material is not lower than the strength of the raw material. Furthermore, the vibration reduction characteristics of the elastic material itself are utilized to further achieve the purpose of vibration reduction in the water pump.

[0006] A method for designing a water pump volute for vibration reduction, the method comprising:

[0007] S1. Arrange n semi-cylindrical modification zones evenly in the volute, and arrange semi-cylindrical modification zones symmetrically on both sides of the volute outlet expansion tube.

[0008] S2. Obtain a wall position point at a certain location in the volute, install an accelerometer at the corresponding position point on the outer wall of the volute, and confirm the vibration acceleration amplitude and frequency.

[0009] S3. Measure the damping ratio and elastic modulus of the elastic material respectively, and set the vibration reduction target;

[0010] S4. Analyze the relationship between the target vibration acceleration amplitude and the initial vibration acceleration amplitude based on the vibration acceleration amplitude;

[0011] S5. Analyze the stiffness coefficient of the elastic material based on the target vibration acceleration amplitude to confirm the design scheme of the modification area.

[0012] Preferably, S1 includes: designing a semi-cylindrical modification area centered on a certain wall surface of the vortex chamber, taking the wall surface location point A as the center;

[0013] The semi-cylinder is defined with radius r along the radial direction of the volute and height h along the axial direction of the volute; the modified area is made of elastic material.

[0014] Preferably, S2 includes: obtaining a wall position point A at a certain location in the volute chamber, installing an acceleration sensor at a position point A1 on the outer wall of the volute corresponding to point A, and then measuring the vibration acceleration amplitude at point A1 as a under normal operating conditions of the water pump, and obtaining the main frequency at that location as f through spectrum analysis.

[0015] Preferably, S3 includes:

[0016] S3-1. Determine the damping ratio ζ of elastic materials using the impulse response method;

[0017] S3-2. Determine the elastic modulus E of the elastic material through a compression test;

[0018] S3-3. Set a vibration reduction target, planning to reduce the vibration acceleration amplitude at point A1 to a. aim and below.

[0019] Preferably, S4 includes:

[0020] Once the vibration acceleration amplitude 'a' is obtained, the relationship between the target vibration acceleration amplitude and the initial vibration acceleration amplitude can be derived using the vibration acceleration amplitude calculation formula for a damped vibration system:

[0021]

[0022] Among them, a aim It is the amplitude of the target vibration acceleration, in meters. 2 / s; a is the initial vibration acceleration amplitude measured at point A1, in meters. 2 / s;ω 激励 It is the angular frequency corresponding to the excitation force, ω 激励 =2πf, unit is rad / s; ω n ζ is the natural frequency of the modified area, measured in rad / s; ζ is the damping ratio.

[0023] Preferably, S5 includes:

[0024] S5-1. Obtain the natural frequency ω of the modified area. n According to the formula The stiffness coefficient k of the elastic material is obtained;

[0025] Where m is the mass of the elastic material in the modified area, in kg;

[0026] S5-2. Obtain the stiffness coefficient k and the elastic modulus E of the elastic material according to the formula. Confirm the cross-sectional area A;

[0027] Where A is the cross-sectional area perpendicular to the direction of the force; L is the length of the body subjected to the force, L = 2r;

[0028] S5-3. Obtain the cross-sectional area A. Then, according to the formula A = 2rh, V aim减振 =πr 2 h, obtain the volume V of the modified area. aim减振 And it was used as a design scheme.

[0029] Preferably, the strength of the elastic material is not lower than the strength of the raw material.

[0030] Preferably, the elastic material wall surface is edged; a width of 0.1mm to 0.5mm (inclusive) is left at the edge of the modified area for edge sealing; no edge sealing is provided within a range of 0.5mm to 2mm (inclusive) extending outward from the center point of the modified area.

[0031] A computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps in the above-described method for designing a water pump volute for vibration reduction.

[0032] A computer device includes a memory, a processor, and a computer program stored in the memory and running on the processor, wherein the processor executes the program to implement the steps in the above-described method for designing a water pump volute for vibration reduction.

[0033] Compared with the prior art, the beneficial effects achieved by the present invention are:

[0034] This invention addresses the issue of pump vibration reduction during operation. As the fluid flows out through the rotating impeller, it impacts and compresses the volute casing wall. The interaction between the rotating impeller and the stationary volute casing wall (dynamic-static interference) generates pressure pulsations. Significant pressure pulsations can lead to vibration noise, reduced pump efficiency, and even compromised safe and stable operation. This invention reduces pump vibration by processing the volute casing wall into an elastic material. This invention offers advantages such as novel structure, energy efficiency, and ease of design. Attached Figure Description

[0035] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0036] Figure 1 This is a flowchart of a water pump volute design method for vibration reduction according to the present invention;

[0037] Figure 2 This is a cross-sectional view of a water pump casing according to the present invention;

[0038] Figure 3 This invention provides a design method for a water pump volute for vibration reduction.

[0039] Figure 4 This is a schematic diagram of a partial structure of the modified area at point II of the water pump casing according to the present invention;

[0040] In the diagram: 1-Impeller; 2-Vortex; 3-Elastic material modification area; 4-Edge; 5-Point A; 6-Point A1. Detailed Implementation

[0041] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0042] Please see Figures 1-4 The present invention provides the following technical solution:

[0043] A method for designing a water pump volute for vibration reduction, the method comprising:

[0044] S1. Arrange n semi-cylindrical modification zones evenly in the volute, and arrange semi-cylindrical modification zones symmetrically on both sides of the volute outlet expansion tube.

[0045] Preferably, S1 includes: designing a semi-cylindrical modification area centered on a certain wall surface of the vortex chamber, taking the wall surface location point A as the center;

[0046] The semi-cylinder is defined with radius r along the radial direction of the volute and height h along the axial direction of the volute; the modified area is made of elastic material.

[0047] Preferably, the strength of the elastic material is not lower than the strength of the raw material.

[0048] Preferably, the elastic material wall surface is edged; a width of 0.1mm to 0.5mm (inclusive) is left at the edge of the modified area for edge sealing; no edge sealing is provided within a range of 0.5mm to 2mm (inclusive) extending outward from the center point of the modified area.

[0049] S2. Obtain a wall position point at a certain location in the volute, install an accelerometer at the corresponding position point on the outer wall of the volute, and confirm the vibration acceleration amplitude and frequency.

[0050] Preferably, S2 includes: obtaining a wall position point A at a certain location in the volute chamber, installing an acceleration sensor at a position point A1 on the outer wall of the volute corresponding to point A, and then measuring the vibration acceleration amplitude at point A1 as a under normal operating conditions of the water pump, and obtaining the main frequency at that location as f through spectrum analysis.

[0051] S3. Measure the damping ratio and elastic modulus of the elastic material respectively, and set the vibration reduction target;

[0052] Preferably, S3 includes:

[0053] S3-1. Determine the damping ratio ζ of elastic materials using the impulse response method;

[0054] S3-2. Determine the elastic modulus E of the elastic material through a compression test;

[0055] S3-3. Set a vibration reduction target, planning to reduce the vibration acceleration amplitude at point A1 to a. aim and below.

[0056] S4. Analyze the relationship between the target vibration acceleration amplitude and the initial vibration acceleration amplitude based on the vibration acceleration amplitude;

[0057] Preferably, S4 includes:

[0058] Once the vibration acceleration amplitude 'a' is obtained, the relationship between the target vibration acceleration amplitude and the initial vibration acceleration amplitude can be derived using the vibration acceleration amplitude calculation formula for a damped vibration system:

[0059]

[0060] Among them, a aim It is the amplitude of the target vibration acceleration, in meters. 2 / s; a is the initial vibration acceleration amplitude measured at point A1, in meters. 2 / s;ω 激励 It is the angular frequency corresponding to the excitation force, ω 激励 =2πf, unit is rad / s; ω n ζ is the natural frequency of the modified area, measured in rad / s; ζ is the damping ratio.

[0061] S5. Analyze the stiffness coefficient of the elastic material based on the target vibration acceleration amplitude to confirm the design scheme of the modification area.

[0062] Preferably, S5 includes:

[0063] S5-1. Obtain the natural frequency ω of the modified area. n According to the formula The stiffness coefficient k of the elastic material is obtained;

[0064] Where m is the mass of the elastic material in the modified area, in kg;

[0065] S5-2. Obtain the stiffness coefficient k and the elastic modulus E of the elastic material according to the formula. Confirm the cross-sectional area A;

[0066] Where A is the cross-sectional area perpendicular to the direction of the force; L is the length of the body subjected to the force, L = 2r;

[0067] S5-3. Obtain the cross-sectional area A. Then, according to the formula A = 2rh, V aim减振 =πr 2 h, obtain the volume V of the modified area. aim减振 And it was used as a design scheme.

[0068] Example 1:

[0069] A water pump has a volute casing wall thickness of 3 mm. The selected elastic material meets the strength requirements.

[0070] The detailed design steps are as follows:

[0071] S1: Determine the modification plan. Distribute eight semi-cylindrical modification zones evenly in the volute chamber, and symmetrically distribute two semi-cylindrical modification zones on both sides of the volute outlet expansion tube;

[0072] Taking the wall surface at volute II as an example, a modification area is designed centered on point A of this wall surface. The radius of the semi-cylinder is 2.5 mm (along the radial direction of the volute), and the height of the cylinder is h (along the axial direction of the volute). The modification material is selected as an elastic material.

[0073] S2: An acceleration sensor is installed at position A1 on the outer wall of the volute corresponding to point A. Under normal operating conditions of the water pump, the vibration acceleration amplitude at point A1 is measured to be a = 0.9 m / s². 2 Spectral analysis revealed that the dominant frequency at this location is f = 193.3 Hz.

[0074] S3: The damping ratio ζ of the elastic material was determined to be 0.15 by the impulse response method, and the elastic modulus E of the elastic material was determined to be 5 GPa by the compression test.

[0075] S4: Set the vibration reduction target. The plan is to reduce the vibration acceleration amplitude at point A1 to a. aim =0.3m / s 2 and below.

[0076] S5: Based on the formula for calculating the vibration acceleration amplitude in a damped vibration system, the relationship between the target vibration acceleration amplitude and the initial vibration acceleration amplitude is derived:

[0077]

[0078] In the formula, a aim It is the amplitude of the target vibration acceleration, a aim =0.3m / s 2 ; a is the initial vibration acceleration amplitude measured at point A1, a = 0.9 m / s². 2 ;ω 激励 It is the angular frequency corresponding to the excitation force, ω 激励 =2πf=2π×193.3=1214.54rad / s; ω n ζ is the natural frequency of the renovated area, in rad / s; ζ is the damping ratio, ζ = 0.15.

[0079] S6: Calculate the ω n =160.6rad / s Substituting this into formula (2) yields the stiffness coefficient k of the elastic material;

[0080]

[0081] In the formula, m is the mass of the elastic material in the modified area, m = 1.8 × 10 3 kg;

[0082] but

[0083] S7: According to the stiffness coefficient expression:

[0084] In the formula, A is the cross-sectional area perpendicular to the direction of the force, A = 2rh = (0.005h)m 2 L is the length of the body subjected to force, L = 2r;

[0085] Furthermore, substituting the k calculated in step S7 into formula (3) yields h = 0.00929m = 9.29mm;

[0086] At this point, the volume of the modified area is V. aim减振 =πr 2 h = π × 2.5 2 ×9.29=182.41mm 3 ;

[0087] S8: Design the edging of the modified area. Leave a 0.2mm width at the edge of the modified area for sealing the holes; at the same time, do not seal the holes within a range extending outward from the center point A of the modified area by 0.76mm. Design complete.

[0088] The innovation of this invention lies in the following: During pump operation, fluid flows out through the rotating impeller, impacting and compressing the volute casing wall. The interaction between the rotating impeller and the stationary volute casing wall, i.e., dynamic-static interference, generates pressure pulsations. Significant pressure pulsations can lead to vibration noise, reduced pump efficiency, and even affect the safe and stable operation of the pump system. This invention provides a pump volute casing design method for vibration reduction, by processing the volute casing wall into an elastic material, thereby achieving the purpose of pump vibration reduction. This invention has advantages such as novel structure, energy saving and efficiency improvement, and ease of design.

[0089] Example 2:

[0090] The computer-readable storage medium of this embodiment stores a computer program that, when executed by a processor, implements the steps in a water pump volute design method for vibration reduction according to Embodiment 1.

[0091] The computer-readable storage medium in this embodiment can be an internal storage unit of the terminal, such as the terminal's hard disk or memory; the computer-readable storage medium in this embodiment can also be an external storage device of the terminal, such as a plug-in hard disk, smart memory card, secure digital card, flash memory card, etc. equipped on the terminal; furthermore, the computer-readable storage medium can include both the terminal's internal storage unit and external storage devices.

[0092] The computer-readable storage medium of this embodiment is used to store computer programs and other programs and data required by the terminal. The computer-readable storage medium can also be used to temporarily store data that has been output or will be output.

[0093] Example 3:

[0094] The computer device of this embodiment includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the program, it implements the steps in the water pump volute design method for vibration reduction of Embodiment 1.

[0095] In this embodiment, the processor can be a central processing unit, or other general-purpose processors, digital signal processors, application-specific integrated circuits, off-the-shelf programmable gate arrays or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor can be a microprocessor or any conventional processor, etc. The memory can include read-only memory and random access memory, and provides instructions and data to the processor. A portion of the memory can also include non-volatile random access memory. For example, the memory can also store device type information.

[0096] Those skilled in the art will understand that the content disclosed in the embodiments can be provided as a method, system, or computer program product. Therefore, this solution can take the form of a hardware embodiment, a software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this solution can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage and optical storage) containing computer-usable program code.

[0097] This solution is described with reference to flowchart illustrations and / or schematic diagrams of methods and computer program products according to embodiments of this solution. It should be understood that each block of the flowchart illustrations and / or schematic diagrams, and combinations of blocks of the flowchart illustrations and / or schematic diagrams, can be implemented by computer program instructions; these computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing device to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing device, generate instructions for implementing the flowchart illustrations and / or block combinations. Figure 1 One or more processes and / or methods are illustrated. Figure 1 A device that provides the functions specified in one or more boxes.

[0098] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or methods are illustrated. Figure 1 The function specified in one or more boxes.

[0099] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or methods are illustrated. Figure 1 The steps of the function specified in one or more boxes.

[0100] Those skilled in the art will understand that all or part of the processes in the above embodiments can be implemented by a computer program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. The storage medium can be a magnetic disk, optical disk, read-only memory (ROM), or random access memory (RAM), etc.

[0101] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for designing a water pump volute for vibration reduction, characterized by: The method comprises: S1, uniformly arranged in the volute chamber a semi-cylinder reconstruction area, and the semi-cylinder reconstruction area is symmetrically arranged on both sides of the volute outlet expansion pipe S2, acquiring a wall surface position point of the cochlear chamber, installing an acceleration sensor at a cochlear shell outer wall position point corresponding to the wall surface position point, and confirming the vibration acceleration amplitude and frequency; S3, respectively measuring the damping ratio and elastic modulus of the elastic material, and setting a vibration reduction target; S4, analyzing the relationship between the target vibration acceleration amplitude and the initial vibration acceleration amplitude according to the vibration acceleration amplitude; S5, analyzing the stiffness coefficient of the elastic material according to the target vibration acceleration amplitude, and confirming the design scheme of the reconstruction area; The S1 comprises: based on a wall surface of the cochlear chamber, taking the wall surface position point A as the center to design a semi-cylindrical reconstruction area. Wherein set along the volute radial direction, the semicircular cylinder radius is , along the volute axial direction, the cylinder height is h; the material of the reconstruction area is elastic material; The S2 comprises: acquiring a wall position point A of a cochlea chamber, installing an acceleration sensor at a position point A1 of an outer wall of the cochlea chamber corresponding to the point A, and measuring a vibration acceleration amplitude at the position point A1 under a normal operation condition of the water pump , and obtaining a main frequency at the position point A1 through frequency spectrum analysis . The S3 comprises: S3-1. Determining the damping ratio of an elastic material by the impulse response method ; S3-2, Determining the elastic modulus of an elastic material by compression test ; S3-3, set a damping target, plan to reduce the vibration acceleration amplitude at A1 to and the following; The S4 comprises: Obtaining vibration acceleration amplitude Then, according to the formula of vibration acceleration amplitude in the damped vibration system, the relationship between the target vibration acceleration amplitude and the initial vibration acceleration amplitude is obtained: ； wherein, is the target vibration acceleration amplitude, in units of ; is the initial vibration acceleration amplitude measured at A1, in units of ; is the angular frequency corresponding to the excitation force, , in units of ; is the natural frequency of the retrofit zone, in units of ; is the damping ratio; The S5 comprises: S5-1, obtaining the inherent frequency of the reconstruction area , according to the formula , the stiffness coefficient of the elastic material is obtained ; wherein is the mass of the elastic material of the modification zone, in kg ; S5-2, obtaining the stiffness coefficient and the elastic modulus of the elastic material , according to the formula , confirming the cross-sectional area ; wherein is the cross-sectional area perpendicular to the force direction; is the length of the force receiver, ; S5-3, obtain cross-sectional area Then, according to the formula , , the volume of the reconstruction zone is obtained and is taken as the design scheme.

2. A method for designing a water pump volute for vibration reduction as recited in claim 1 wherein, The strength of the elastic material is not less than the strength of the original material.

3. A method for designing a water pump volute for vibration reduction as recited in claim 1 wherein, The elastic material wall surface is edge-wrapped; a width of 0.1mm-0.5mm is left at the edge of the reconstruction area for edge wrapping and hole sealing; a range of 0.5mm-2mm is extended outward from the center point of the reconstruction area without setting a hole sealing edge.

4. A computer readable storage medium having stored thereon a computer program, characterized in that: The program is executed by the processor to implement the steps in the water pump cochlear shell design method for vibration reduction according to any one of claims 1-3.

5. A computer device comprising a memory, a processor, and a computer program stored on the memory and running on the processor, characterized in that, The processor executes the program to implement the steps in the water pump cochlear shell design method for vibration reduction according to any one of claims 1-3.

Images