Design method of water pump volute for vibration reduction

Abstract

The invention relates to the field of hydraulic machinery in hydraulic engineering, in particular to a design method of a water pump volute for vibration reduction. Comprising an impeller, a volute and an elastic material wall surface, the pumping chamber is an important component in the operation process of the water pump and is favorable for collecting fluid pressed out of an impeller, reducing the flow speed and recycling part of energy, so that the fluid smoothly flows out of the pump; in the operation process of the water pump, fluid flows out through rotation of the impeller and impacts and extrudes the wall face of the volute, pressure pulsation can be generated through interaction, namely dynamic and static interference, between the wall face of the rotating impeller and the wall face of the static volute, and large pressure pulsation can cause vibration noise to be generated, reduce the operation efficiency of the water pump and even affect safe and stable operation of a pump device. The wall face of the volute is machined into the wall face made of the elastic material, pressure pulsation caused by dynamic and static interference is buffered, the purpose of water pump vibration reduction is achieved, and the volute has the advantages of being novel in structure, saving energy, improving efficiency, being easy to design and the like.

Description

Technical Field

[0001] The invention relates to the field of hydraulic machinery in water conservancy projects, and in particular to a design method for a water pump volute for vibration reduction. Background Art

[0002] During the operation of the water pump, the fluid flows out through the rotation of the impeller, impacts and squeezes the volute wall, and the interaction between the rotating impeller and the stationary volute wall, i.e., dynamic-static interference, will produce pressure pulsation. Large pressure pulsation will cause vibration and noise, reduce the operating efficiency of the water pump, and even affect the safe and stable operation of the pump device. The present invention provides a water pump volute design method for vibration reduction to solve this problem. Summary of the invention

[0003] The object of the present invention is to provide a water pump volute design method for vibration reduction to solve the problems raised in the above background technology.

[0004] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0005] The purpose of the present invention is achieved as follows: first, a transformation plan is determined. One of the transformation areas is selected as an example, and the vibration acceleration amplitude of the corresponding volute outer wall position point is obtained. By setting the target vibration acceleration amplitude, the relevant size of the transformation area is calculated, and then the volume of the transformation area is determined. The strength of the elastic material is not lower than the strength of the raw material. And the vibration reduction characteristics of the elastic material itself are used to further achieve the purpose of water pump vibration reduction.

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

[0007] S1. n semi-cylindrical transformation areas are evenly arranged in the volute chamber, and semi-cylindrical transformation areas are symmetrically arranged on both sides of the volute outlet expansion pipe;

[0008] S2, obtaining a certain wall position point of the volute chamber, installing an acceleration sensor at a position point on the outer wall of the volute corresponding to the wall position point, and confirming the vibration acceleration amplitude and frequency;

[0009] S3, respectively measuring the damping ratio and elastic modulus of the elastic material and setting a vibration reduction target;

[0010] S4. Analyzing the relationship between the target vibration acceleration amplitude and the initial vibration acceleration amplitude according to the vibration acceleration amplitude;

[0011] S5. Analyze the stiffness coefficient of the elastic material according to the target vibration acceleration amplitude and confirm the design plan of the transformation area.

[0012] Preferably, S1 includes: based on a wall surface of a certain location of the volute chamber, taking the wall surface position point A as the center to design a semi-cylindrical transformation area;

[0013] The radius of the semi-cylinder along the radial direction of the volute is set to r, and the height of the cylinder along the axial direction of the volute is set to h; the material of the transformation area is an elastic material.

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

[0015] Preferably, S3 includes:

[0016] S3-1, determining the damping ratio ζ of the elastic material by the impulse response method;

[0017] S3-2, determining the elastic modulus E of the elastic material by compression test;

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

[0019] Preferably, S4 includes:

[0020] Obtain the vibration acceleration amplitude a, and then according to the vibration acceleration amplitude calculation formula in the damped vibration system, obtain the relationship between the target vibration acceleration amplitude and the initial vibration acceleration amplitude:

[0021]

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

[0023] Preferably, S5 includes:

[0024] S5-1. Obtain the natural frequency ω of the transformation area n , according to the formula Get the stiffness coefficient k of the elastic material;

[0025] Where m is the mass of the elastic material in the transformation 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 force; L is the length of the force-bearing body, 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, and the volume V of the transformation zone is obtained aim减振 , and use it as a design solution.

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

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

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

[0032] A computer device comprises a memory, a processor and a computer program stored in the memory and running on the processor. When the processor executes the program, the steps in the above-mentioned method for designing a water pump volute for vibration reduction are implemented.

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

[0034] During the operation of the water pump of the present invention, the fluid flows out through the rotation of the impeller, impacts and squeezes the volute wall, and the interaction between the rotating impeller and the stationary volute wall, i.e., the dynamic and static interference, will produce pressure pulsation. Large pressure pulsation will cause vibration and noise, reduce the operating efficiency of the water pump, and even affect the safe and stable operation of the pump device. The present invention achieves the purpose of reducing vibration of the water pump by processing the volute wall into an elastic material wall. The present invention has the advantages of novel structure, energy saving and efficiency improvement, and easy design. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0036] Figure 1 It is a flow chart of a method for designing a water pump volute for vibration reduction according to the present invention;

[0037] Figure 2 It is a cross-sectional view of a water pump volute of the present invention;

[0038] Figure 3 The present invention provides a method for designing a water pump volute for vibration reduction;

[0039] Figure 4 It is a schematic diagram of the partial structure of the transformation area at point II of a water pump volute of the present invention;

[0040] In the figure: 1-impeller; 2-volute; 3-elastic material transformation area; 4-edge wrapping; 5-point A; 6-point A1. DETAILED DESCRIPTION

[0041] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0042] See also Figure 1-Figure 4 , the present invention provides a technical solution:

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

[0044] S1. n semi-cylindrical transformation areas are evenly arranged in the volute chamber, and semi-cylindrical transformation areas are symmetrically arranged on both sides of the volute outlet expansion pipe;

[0045] Preferably, S1 includes: based on a wall surface of a certain location of the volute chamber, taking the wall surface position point A as the center to design a semi-cylindrical transformation area;

[0046] The radius of the semi-cylinder along the radial direction of the volute is set to r, and the height of the cylinder along the axial direction of the volute is set to h; the material of the transformation area is an elastic material.

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

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

[0049] S2, obtaining a certain wall position point of the volute chamber, installing an acceleration sensor at a position point on the outer wall of the volute corresponding to the wall position point, and confirming the vibration acceleration amplitude and frequency;

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

[0051] S3, respectively measuring the damping ratio and elastic modulus of the elastic material and setting a vibration reduction target;

[0052] Preferably, S3 includes:

[0053] S3-1, determining the damping ratio ζ of the elastic material by the impulse response method;

[0054] S3-2, determining the elastic modulus E of the elastic material by compression test;

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

[0056] S4. Analyzing the relationship between the target vibration acceleration amplitude and the initial vibration acceleration amplitude according to the vibration acceleration amplitude;

[0057] Preferably, S4 includes:

[0058] Obtain the vibration acceleration amplitude a, and then according to the vibration acceleration amplitude calculation formula in the damped vibration system, obtain the relationship between the target vibration acceleration amplitude and the initial vibration acceleration amplitude:

[0059]

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

[0061] S5. Analyze the stiffness coefficient of the elastic material according to the target vibration acceleration amplitude and confirm the design plan of the transformation area.

[0062] Preferably, S5 includes:

[0063] S5-1. Obtain the natural frequency ω of the transformation area n , according to the formula Get the stiffness coefficient k of the elastic material;

[0064] Where m is the mass of the elastic material in the transformation 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 force; L is the length of the force-bearing body, 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, and the volume V of the transformation zone is obtained aim减振 , and use it as a design solution.

[0068] Embodiment 1:

[0069] It is known that the wall thickness of the volute of a water pump is 3mm. The strength of the selected elastic material meets the requirements.

[0070] The detailed design steps are as follows:

[0071] S1: Determine the transformation plan. Evenly arrange 8 semi-cylindrical transformation areas in the volute chamber, and symmetrically arrange 2 semi-cylindrical transformation areas on both sides of the volute outlet expansion pipe;

[0072] Taking the wall surface of the volute chamber II as an example, a transformation area is designed with the wall position point A as the center. 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 transformation material is selected as an elastic material.

[0073] S2: An acceleration sensor is installed at point A1 on the outer wall of the volute corresponding to point A. The vibration acceleration amplitude at point A1 is measured to be a=0.9m / s under normal operation of the pump. 2 Through spectrum analysis, we find that the main frequency here is f=193.3Hz.

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

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

[0076] S5: According to the vibration acceleration amplitude calculation formula in the 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 is the target vibration acceleration amplitude, a aim =0.3m / s 2 ; a is the initial vibration acceleration amplitude measured at A1, a = 0.9m / s 2 ;ω 激励 is the angular frequency corresponding to the excitation force, ω 激励 =2πf=2π×193.3=1214.54rad / s; ω n is the natural frequency of the transformation area, in rad / s; ζ is the damping ratio, ζ = 0.15.

[0079] S6: The calculated ω n =160.6rad / s Substitute into formula (2) to obtain the stiffness coefficient k of the elastic material;

[0080]

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

[0082] but

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

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

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

[0086] At this time, the volume of the transformation zone is V aim减振 =πr 2 h=π×2.5 2 ×9.29=182.41mm 3 ;

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

[0088] The innovation of the present invention is that during the operation of the water pump, the fluid flows out through the rotation of the impeller, impacts and squeezes the volute wall, and the interaction between the rotating impeller and the stationary volute wall, i.e., dynamic-static interference, will produce pressure pulsation. Large pressure pulsation will cause vibration noise, reduce the operating efficiency of the water pump, and even affect the safe and stable operation of the pump device. To solve this problem, the present invention provides a water pump volute design method for vibration reduction, by processing the volute wall into an elastic material wall, thereby achieving the purpose of water pump vibration reduction. The present invention has the advantages of novel structure, energy saving and efficiency improvement, and easy design.

[0089] Embodiment 2:

[0090] The computer-readable storage medium of this embodiment stores a computer program thereon, and when the program is executed by a processor, the steps in the method for designing a water pump volute for vibration reduction in embodiment 1 are implemented.

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

[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 is to be output.

[0093] Embodiment 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, the steps of a water pump volute design method for vibration reduction in Embodiment 1 are implemented.

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

[0096] Those skilled in the art will appreciate that the disclosed content of the embodiments may be provided as methods, systems, or computer program products. Therefore, the present solution may adopt the form of hardware embodiments, software embodiments, or embodiments combining software and hardware. Moreover, the present solution may adopt 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, etc.) containing computer-usable program codes.

[0097] The present solution is described with reference to the method according to the embodiment of the present solution and the flowchart and / or block diagram of the computer program product. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of the processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions; these computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 one or more processes and / or methods Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0098] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 one or more processes and / or methods Figure 1 A function specified in one or more boxes.

[0099] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 one or more processes and / or methods Figure 1 The steps for the functions specified in one or more boxes.

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

[0101] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for designing a water pump volute for vibration reduction, characterized in that: The method comprises: S1. n semi-cylindrical transformation areas are evenly arranged in the volute chamber, and semi-cylindrical transformation areas are symmetrically arranged on both sides of the volute outlet expansion pipe; S2, obtaining a certain wall position point of the volute chamber, installing an acceleration sensor at a position point on the outer wall of the volute corresponding to the wall 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. Analyze the stiffness coefficient of the elastic material according to the target vibration acceleration amplitude and confirm the design plan of the transformation area.

2. A method for designing a water pump volute for vibration reduction according to claim 1, characterized in that: The step S1 includes: based on a wall surface of the volute chamber, taking the wall surface position point A as the center, designing a semi-cylindrical transformation area; The radius of the semi-cylinder along the radial direction of the volute is set to r, and the height of the cylinder along the axial direction of the volute is set to h; the material of the transformation area is an elastic material.

3. A method for designing a water pump volute for vibration reduction according to claim 1, characterized in that: The S2 includes: obtaining a certain wall position point A of the volute chamber, installing an acceleration sensor at a position point A1 on the outer wall of the volute corresponding to point A, then under the normal operating condition of the water pump, the vibration acceleration amplitude at A1 is measured to be a, and the main frequency at this point is obtained as f through spectrum analysis.

4. A method for designing a water pump volute for vibration reduction according to claim 1, characterized in that: The S3 includes: S3-1, determining the damping ratio ζ of the elastic material by the impulse response method; S3-2, determining the elastic modulus E of the elastic material by compression test; S3-3, set the vibration reduction target, plan to reduce the vibration acceleration amplitude at A1 to a aim and below.

5. A method for designing a water pump volute for vibration reduction according to claim 1, characterized in that: The S4 comprises: Obtain the vibration acceleration amplitude a, and then according to the vibration acceleration amplitude calculation formula in the damped vibration system, obtain the relationship between the target vibration acceleration amplitude and the initial vibration acceleration amplitude: Among them, a aim is the target vibration acceleration amplitude, in m 2 / s; a is the initial vibration acceleration amplitude measured at A1, in m 2 / s;ω 激励 is the angular frequency corresponding to the excitation force, ω 激励 =2πf, in rad / s; ω n is the natural frequency of the transformation area, in rad / s; ζ is the damping ratio.

6. A method for designing a water pump volute for vibration reduction according to claim 1, characterized in that: The S5 comprises: S5-1. Obtaining the natural frequency ω of the transformation area n , according to the formula Get the stiffness coefficient k of the elastic material; Where m is the mass of the elastic material in the transformation area, in kg; 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; Where A is the cross-sectional area perpendicular to the direction of force; L is the length of the force-bearing body, L = 2r; S5-3. Obtain the cross-sectional area A. Then according to the formula A=2rh, V aim减振 =πr 2 h, and the volume of the transformation zone V is obtained aim减振 , and use it as a design solution.

7. A method for designing a water pump volute for vibration reduction as claimed in claim 2, characterized in that: The strength of the elastic material is not lower than the strength of the raw material.

8. A method for designing a water pump volute for vibration reduction according to claim 1, characterized in that: The wall surface of the elastic material is edged; a width of 0.1mm to 0.5mm 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 extending outward from the center point of the modified area.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the steps in a method for designing a water pump volute for vibration reduction as described in any one of claims 1 to 8 are implemented.

10. A computer device comprising a memory, a processor, and a computer program stored in the memory and running on the processor, characterized in that: When the processor executes the program, the steps of a water pump volute design method for vibration reduction are implemented as described in any one of claims 1-8.

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