Method and device for analyzing vibration transfer characteristics of pump rotor system

Abstract

The invention discloses a pump rotor system vibration transmission characteristic analysis method and device, and the method comprises the steps: building an actual pump rotor solid model, and obtaining a water body model for pump calculation; calculating the internal flow exciting force of the pump; internal flow exciting force data are extracted; grid division is conducted on the pump rotor solid model, and a finite element calculation model is established; setting the contact relation among the impeller, the shaft, the bearing and the motor part and the rigidity value of the bearing on the shaft; applying the extracted internal flow exciting force to the surface of the corresponding part and adding a rotating speed to the rotating part; solving the finite element calculation model; and performing post-processing analysis on the calculation result to obtain an acceleration spectrogram of each component. By the adoption of the technical scheme, the problem that an existing method for analyzing the vibration transmission characteristics of the pump rotor system has defects is solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of pump rotor systems, and particularly relates to a method and device for analyzing the vibration transfer characteristics of a pump rotor system. Background Art

[0002] Pump equipment is widely used in engineering fields such as the energy industry, transportation, equipment manufacturing, and aerospace. Among them, centrifugal pumps, centrifugal compressors, water turbines, and steam turbines are typical rotating machinery. The former two are used to convert mechanical energy into the potential energy and kinetic energy of fluids, while the latter two convert the potential energy and kinetic energy of fluids into mechanical energy. In these devices, the rotor system is its core component. Rotating machinery often affects normal operation due to various forms of vibration. The rotor is the main working component of rotating machinery and may vibrate during machine operation, resulting in noise, reduced work efficiency, and even strong vibrations in some cases, causing the shaft or blade to break, and thus leading to significant economic losses.

[0003] Traditional rotor dynamics research is usually based on linear theory. Although reasonable linearization methods can reduce the workload and solve some practical problems in past applications, with the continuous increase in the rotational speed of rotating machinery, rotor design based on linear theory often cannot accurately reflect the actual operating conditions of the unit. There are non-linear excitation sources such as oil film force, sealing force, and fluid-structure coupling force in rotating machinery, and the deficiencies of linear theory in solving rotor dynamics problems are becoming increasingly apparent. Therefore, there is an urgent need to adopt other methods to better master the actual problems in rotating machinery, so as to more effectively utilize and control various non-linear dynamic behaviors. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a method and device for analyzing the vibration transfer characteristics of a pump rotor system.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] A method for analyzing the vibration transfer characteristics of a pump rotor system includes:

[0007] Step 1: Establish an actual solid model of the pump rotor and obtain the water body model for pump calculation at the same time;

[0008] Step 2: Calculate the internal flow excitation force of the pump;

[0009] Step 3: Extract the internal flow excitation force data calculated in Step 2;

[0010] Step 4: Mesh the solid model of the pump rotor in Step 1 to establish a finite element calculation model;

[0011] Step 5: Set the contact relationships among the impeller, shaft, bearings, and motor components and the stiffness values of the bearings on the shaft;

[0012] Step 6: Apply the internal flow excitation force extracted in Step 3 to the surfaces of the corresponding components and add rotational speeds to the rotating components;

[0013] Step 7: Solve the finite element calculation model;

[0014] Step 8: Post-process and analyze the calculation results to obtain the acceleration spectrograms of each component.

[0015] Preferably, the solid model components in Step 1 include: impeller, shaft, bearings, and a simplified motor.

[0016] Preferably, the water body model components in Step 1 include: inlet section, impeller water body, volute water body, and outlet section.

[0017] Preferably, the component contact relationship in Step 5 is bonding, the bearing and the shaft are connected by bearings, and the outer surface of the bearing is grounded.

[0018] Preferably, the post-processing analysis of each component in Step 8 is to extract its acceleration in the time and x directions, perform a fast Fourier transform to obtain the spectrogram of the acceleration in the x direction, and then analyze the vibration transmission characteristics of the pump rotor system.

[0019] The present invention also provides an analysis device for the vibration transmission characteristics of a pump rotor system, including:

[0020] A first processing module for establishing an actual solid model of the pump rotor and simultaneously obtaining a water body model for pump calculation;

[0021] A second processing module for calculating the internal flow excitation force of the pump;

[0022] A third processing module for extracting internal flow excitation force data;

[0023] A fourth processing module for meshing the solid model of the pump rotor and establishing a finite element calculation model;

[0024] A fifth processing module for setting the contact relationships among the impeller, shaft, bearings, and motor components and the stiffness values of the bearings on the shaft;

[0025] A sixth processing module for applying the extracted internal flow excitation force to the surfaces of the corresponding components and adding rotational speeds to the rotating components;

[0026] A seventh processing module for solving the finite element calculation model;

[0027] An eighth processing module for post-processing and analyzing the calculation results to obtain the acceleration spectrograms of each component.

[0028] Preferably, the solid model components include: an impeller, a shaft, bearings, and a simplified motor.

[0029] Preferably, the water body model components include: an inlet section, an impeller water body, a volute water body, and an outlet section.

[0030] Preferably, the contact relationship between components is bonding. The bearings are connected to the shaft by bearing connections, and the outer surface of the bearings is grounded.

[0031] Preferably, the eighth processing module performs post-processing analysis on each component by extracting its acceleration in the time and x directions and performing a fast Fourier transform to obtain the frequency spectrum diagram of the acceleration in the x direction, and analyzes the vibration transmission characteristics of the pump rotor system.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] 1) Calculation monitoring points are set for different rotor components, which can comprehensively analyze the vibration transmission path and device deformation of the rotor device;

[0034] 2) By calculating the corresponding pump water body model to extract the internal flow excitation force and further performing finite element calculation on the solid, the force condition of the rotor under actual working conditions can be more accurately reflected;

[0035] 3) The post-processing results can be analyzed to obtain the characteristic frequencies of the vibration of the rotor components, thereby clarifying the key components and excitation types for vibration control in the shafting. Description of the Drawings

[0036] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only the embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained according to the provided drawings without creative efforts.

[0037] Figure 1 It is a flowchart of the analysis method for the vibration transmission characteristics of the pump rotor system of the present invention;

[0038] Figure 2 It is a solid model of the pump rotor, where 1 is the impeller, 2 is the shaft, 3 is the first bearing, 4 is the simplified motor, and 5 is the second bearing;

[0039] Figure 3 It is a water body model for pump calculation, 6 is the inlet section, 7 is the impeller water body, 8 is the volute water body, and 9 is the outlet section;

[0040] Figure 4 It is the post-processing result of the acceleration frequency spectrum diagram of each component. Detailed Embodiments

[0041] Next, in combination with the accompanying drawings in the embodiments of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present invention.

[0042] To make the above objects, features, and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below in combination with the accompanying drawings and specific embodiments.

[0043] Embodiment 1:

[0044] As Figure 1 shown, the embodiment of the present invention provides an analysis method for the vibration transfer characteristics of a pump rotor system, including:

[0045] Step 1: Establish a solid model of the pump rotor through Soildeworks, as Figure 2 shown, and further extract to obtain the water body model for pump calculation, as Figure 3 shown;

[0046] Step 2: Calculate the internal flow excitation force of the pump. Specifically, import the water body model components obtained in Step 1 for mesh division, and then import the divided water body mesh into the simulation calculation software. After setting the corresponding boundary conditions for the calculation, set monitoring points on the coupling surface of the internal flow excitation force, and finally start the calculation, and complete the calculation after ensuring that the residual of the calculation reaches a stable state.

[0047] Further, after setting the corresponding boundary conditions for the calculation, specifically, set the impeller water body to rotate at the working speed, and the rest of the water body to be stationary; set the inlet flow velocity according to the standard working condition flow rate, and set the outlet boundary condition to a pressure outlet with the pressure set to atmospheric pressure; set the impeller wall surface to have no slip and the relative rotational speed of the impeller water body to be zero, and set the rest of the wall surfaces to be absolutely stationary; finally, match the interfaces of different components. Specifically, the outlet of the inlet section is matched with the impeller inlet, the impeller outlet is matched with the volute inlet, and the volute outlet is matched with the inlet of the outlet section.

[0048] Set monitoring points on the coupling surface of the internal flow excitation force, specifically the excitation forces in the x, y, and z directions on the blade surface, the excitation forces in the x, y, and z directions on the front cover surface of the impeller, and the excitation forces in the x, y, and z directions on the rear cover surface of the impeller.

[0049] Step 3: Extract the internal flow excitation force data calculated in Step 2;

[0050] Step 4: Mesh the pump rotor solid model in Step 1 to establish a finite element calculation model, which includes: the equilibrium equations, geometric equations, and constitutive equations of each node;

[0051] Step 5: Set the contact relationships between the impeller, shaft, bearing, and motor components and the stiffness value of the bearing on the shaft;

[0052] Step 6: Apply the internal flow excitation force extracted in Step 3 to the surface of the corresponding component and add a rotational speed to the rotating component. The rotational speed in this embodiment is 1500 rpm;

[0053] Step 7: Solve the finite element calculation model;

[0054] Further, in combination with the equations constructed in Step 5, the boundary conditions and initial conditions applied in Step 6, select a suitable basis function to discretize the solid mesh in the spatial domain, use the finite difference method to discretize in the time domain, and finally numerically solve the discretized equations to obtain the final result.

[0055] Step 8: Post-process and analyze the calculation results to obtain the acceleration spectrogram of each component.

[0056] As an implementation manner of the embodiment of the present invention, the solid model components in Step 1 include an impeller, a shaft, a bearing, and a simplified motor. The water body model components in Step 1 include an inlet section, an impeller water body, a volute water body, and an outlet section. Among them, the impeller, bearing, and motor are all installed on the corresponding axial planes; the outlet of the inlet section is connected to the inlet of the impeller, the outlet of the impeller is connected to the inlet of the volute, and the outlet of the volute is connected to the inlet of the outlet section.

[0057] As an implementation manner of the embodiment of the present invention, the component contact relationship in Step 5 is bonding, the bearing and the shaft are connected by a bearing, and the outer surface of the bearing is grounded.

[0058] As an implementation manner of the embodiment of the present invention, in Step 8, the post-processing analysis of each component is to extract its acceleration in the time and x directions, perform a fast Fourier transform to obtain the spectrogram of the acceleration in the x direction, and then analyze the vibration transfer characteristics of the pump rotor system, as Figure 4 shown.

[0059] Example 2:

[0060] The embodiment of the present invention also provides an analysis device for the vibration transfer characteristics of a pump rotor system, including:

[0061] The first processing module is used to establish an actual pump rotor solid model and simultaneously obtain the water body model for pump calculation;

[0062] The second processing module is used to calculate the internal flow excitation force of the pump;

[0063] The third processing module is used to extract the internal flow excitation force data;

[0064] The fourth processing module is used to mesh the solid model of the pump rotor and establish a finite element calculation model;

[0065] The fifth processing module is used to set the contact relationship between the impeller, shaft, bearing and motor components and the stiffness value of the bearing on the shaft;

[0066] The sixth processing module is used to apply the extracted internal flow excitation force to the surface of the corresponding component and add a rotational speed to the rotating component;

[0067] The seventh processing module is used to solve the finite element calculation model;

[0068] The eighth processing module is used to post-process and analyze the calculation results to obtain the acceleration spectrogram of each component.

[0069] As an implementation manner of the embodiment of the present invention, the solid model components include: an impeller, a shaft, a bearing and a simplified motor.

[0070] As an implementation manner of the embodiment of the present invention, the water body model components include: an inlet section, an impeller water body, a volute water body and an outlet section.

[0071] As an implementation manner of the embodiment of the present invention, the component contact relationship is bonding, the bearing and the shaft are connected by a bearing, and the outer surface of the bearing is grounded.

[0072] As an implementation manner of the embodiment of the present invention, the post-processing analysis of each component by the eighth processing module is to extract its acceleration in the time and x directions, perform a fast Fourier transform to obtain the spectrogram of the acceleration in the x direction, and analyze the vibration transmission characteristics of the pump rotor system

[0073] The above-described embodiments are only descriptions of the preferred embodiments of the present invention, and do not limit the scope of the present invention. Without departing from the design spirit of the present invention, various deformations and improvements made by those of ordinary skill in the art to the technical solutions of the present invention shall fall within the protection scope determined by the claims of the present invention.

Claims

1. A method for analyzing the vibration transmission characteristics of a pump rotor system, characterized in that, including: Step 1: Establish an actual solid model of the pump rotor and simultaneously obtain the water body model for pump calculation; Step 2: Calculate the internal flow excitation force of the pump; Step 3: Extract the internal flow excitation force data calculated in Step 2; Step 4: Mesh the solid model of the pump rotor in Step 1 to establish a finite element calculation model; Step 5: Set the contact relationships between the impeller, shaft, bearing, and motor components and the stiffness value of the bearing on the shaft; Step 6: Apply the internal flow excitation force extracted in Step 3 to the corresponding component surfaces and add a rotational speed to the rotating components; Step 7: Solve the finite element calculation model; Step 8: Post-process and analyze the calculation results to obtain the acceleration spectrum diagrams of each component.

2. The method for analyzing the vibration transmission characteristics of the pump rotor system according to claim 1, characterized in that, The solid model components in Step 1 include: impeller, shaft, bearing, and simplified motor.

3. The method for analyzing the vibration transmission characteristics of the pump rotor system according to claim 2, characterized in that, The water body model components in Step 1 include: inlet section, impeller water body, volute water body, and outlet section.

4. The method for analyzing the vibration transmission characteristics of the pump rotor system according to claim 3, characterized in that The component contact relationship in Step 5 is bonding. The bearing and the shaft are connected by a bearing, and the outer surface of the bearing is grounded.

5. The method for analyzing the vibration transmission characteristics of the pump rotor system according to claim 4, characterized in that, In Step 8, the post-processing analysis of each component is to extract its acceleration in the time and x directions, perform a fast Fourier transform to obtain the spectrum diagram of the x-direction acceleration, and then analyze the vibration transmission characteristics of the pump rotor system.

6. An analysis device for the vibration transfer characteristics of a pump rotor system, characterized in that including: The first processing module is used to establish an actual solid model of the pump rotor and simultaneously obtain the water body model for pump calculation; The second processing module is used to calculate the internal flow excitation force of the pump; The third processing module is used to extract the internal flow excitation force data; The fourth processing module is used to mesh the solid model of the pump rotor to establish a finite element calculation model; The fifth processing module is used to set the contact relationships between the impeller, shaft, bearing, and motor components and the stiffness value of the bearing on the shaft; The sixth processing module is used to apply the extracted internal flow excitation force to the corresponding component surfaces and add a rotational speed to the rotating components; The seventh processing module is used to solve the finite element calculation model; The eighth processing module is used to post-process and analyze the calculation results to obtain the acceleration spectrum diagrams of each component.

7. The vibration transmission characteristic analysis device for a pump rotor system according to claim 6, characterized in that, The solid model components include: impeller, shaft, bearing, and simplified motor.

8. The vibration transmission characteristic analysis device of the pump rotor system according to claim 7, characterized in that The water body model components include: inlet section, impeller water body, volute water body, and outlet section.

9. The vibration transmission characteristic analysis device of the pump rotor system according to claim 8, characterized in that, The component contact relationship is bonding. The bearing and the shaft are connected by a bearing, and the outer surface of the bearing is grounded.

10. The vibration transmission characteristic analysis device of the pump rotor system according to claim 9, characterized in that, The post-processing analysis of each component by the eighth processing module is to extract its acceleration in the time and x directions, perform a fast Fourier transform to obtain the spectrum diagram of the x-direction acceleration, and analyze the vibration transmission characteristics of the pump rotor system.

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