Passive nuclear power plant main pump vibration reduction method and system

Abstract

The invention provides a passive nuclear power plant main pump vibration reduction method and system. The vibration reduction method comprises the steps that 1, original design parameters of a main pump are obtained, and the weight, the damping ratio and an installation fastening scheme of a vibration absorber are determined; step 2, performing a knocking test in a state that the main pump is filled with water to obtain a horizontal inherent frequency and a modal shape of the main pump; 3, according to the inherent frequency in the horizontal direction, determining the frequency and rigidity parameters of the vibration absorber; and 4, simulation verification is conducted on the vibration reduction effect of the main pump, design parameters of the vibration absorber are determined when the vibration reduction effect meets the requirement, and manufacturing, verification and installation of the vibration absorber are completed. By the adoption of the vibration reduction method, the original structure and frequency of the main pump are not changed, normal operation of the main pump is not affected, the arrangement space of the solidified nuclear power station is not changed, the construction difficulty is low, and damage to the main pump can be reduced to the maximum extent in the long-term operation period of the nuclear power station.

Description

Technical Field

[0001] The invention relates to the technical field of vibration reduction of a main pump of a nuclear power plant, and in particular to a vibration reduction method and system for a main pump of a passive nuclear power plant. Background Art

[0002] The main pump of the third-generation passive nuclear power plant is an inverted suspended pump located at the bottom of the steam generator. It is the most important core component of the primary circuit pressure boundary of the nuclear power plant. It is used to drive the circulation of coolant inside the reactor. The quality of its operating status directly affects the safe and stable operation of the nuclear power plant.

[0003] The third-generation passive nuclear power plant has two loops, each loop has two steam generators, and each steam generator is installed with two main pumps. The main pump inlet is connected to the steam generator, and the outlet is connected to the cold section, which is a vertical cantilever beam structure.

[0004] When the main pump is running, the high-temperature and high-pressure fluid excitation load at the main pump outlet acts on the root area of ​​the main pump, making the horizontal vibration amplitude at the free end of the bottom of the main pump the largest. When the fluid excitation frequency is close to the overall frequency of the circuit where the main pump is located, a resonance effect will occur, which will cause the main pump vibration to exceed the limit and affect the normal operation of the nuclear power plant. Therefore, effective measures need to be taken to reduce the vibration of the main pump.

[0005] At present, there are two main methods for reducing the vibration of the main pump in nuclear power projects: one is to change the external excitation load of the main pump, which can be achieved by adjusting the speed of the main pump, but this method is only effective for some operating conditions of nuclear power plants;

[0006] Another method is to change the natural frequency of the overall structure of the circuit where the main pump is located. However, due to the limitations of the already arranged and solidified nuclear island building and installed and solidified main pump components, there are currently no effective external intervention vibration reduction measures to change the natural frequency of the overall circuit.

[0007] Based on this, the inventor of the present application has designed a passive nuclear power plant main pump vibration reduction method and system to overcome the above-mentioned technical problems. Summary of the invention

[0008] The technical problem to be solved by the present invention is to overcome the defect in the prior art that the vibration level of the main pump is too large due to the external excitation load, and to provide a vibration reduction method and system for the main pump of a passive nuclear power plant.

[0009] The present invention solves the above technical problems through the following technical solutions:

[0010] The present invention provides a passive nuclear power plant main pump vibration reduction method, which is characterized by comprising:

[0011] Step 1: Obtain the original design parameters of the main pump and determine the weight, damping ratio and installation and fastening scheme of the vibration absorber;

[0012] Step 2: Perform a tapping test on the main pump when it is filled with water to obtain the horizontal natural frequency and modal vibration shape of the main pump;

[0013] Step 3, determining the frequency and stiffness parameters of the vibration absorber according to the horizontal natural frequency;

[0014] Step 4: Simulate and verify the vibration reduction effect of the main pump, and when the vibration reduction effect meets the requirements, determine the design parameters of the vibration absorber to complete the manufacture, verification and installation of the vibration absorber.

[0015] According to one embodiment of the present invention, in step 1,

[0016] The weight information of the vibration absorber is determined according to the wet weight information of the main pump, the damping ratio of the vibration absorber is determined according to the mass ratio of the vibration absorber to the main pump, and the installation and fastening scheme of the vibration absorber is determined according to the material information of the main pump and the size information of the lifting hole.

[0017] According to one embodiment of the present invention, the optimal damping value calculation formula of the vibration absorber is as follows:

[0018]

[0019] Wherein, μ is the mass ratio of the vibration absorber to the main pump.

[0020] According to one embodiment of the present invention, in step 2,

[0021] By installing an acceleration sensor on the main pump and using a hammer test, the natural frequency f of the main pump in two directions is obtained. x , f y .

[0022] According to one embodiment of the present invention, the frequencies of the vibration absorber in two directions are consistent with those of the main pump.

[0023] According to one embodiment of the present invention, the stiffness calculation formula of the vibration absorber in two directions is as follows:

[0024] k x =(2πf x ) 2 m2;

[0025] k y =(2πf y ) 2 m2;

[0026] Where m2 is the weight of the vibration absorber.

[0027] According to an embodiment of the present invention, in step 4, the main pump vibration reduction effect verification process includes: simulation verification of the main pump vibration reduction effect and analysis verification of the main circuit mechanics influence.

[0028] According to one embodiment of the present invention, the simulation verification process of the vibration reduction effect of the main pump includes:

[0029] Step 41, establishing a finite element model for mechanical analysis of the main pump coupling main circuit;

[0030] Step 42, adding a vibration absorber simulation model at the location where the vibration level of the main pump is the maximum;

[0031] Step 43: Using the main pump outlet position as the vibration source input to calculate the vibration amplitude of the main pump.

[0032] According to one embodiment of the present invention, in the analysis and verification of the impact on the main circuit mechanics, a vibration absorber model is added to the main pump model with excessive vibration, and main pipeline stress assessment, functionality assessment, support assessment, pre-breakage leakage assessment and main equipment takeover assessment are carried out.

[0033] The present invention also provides a passive nuclear power plant main pump vibration reduction system, which is characterized in that the passive nuclear power plant main pump vibration reduction method as described above is adopted, and the vibration reduction system comprises:

[0034] An acquisition module is used to obtain the original design parameters of the main pump and determine the weight, damping ratio and installation and fastening scheme of the vibration absorber;

[0035] The test module is used to perform a tapping test on the main pump when it is filled with water to obtain the horizontal natural frequency and modal vibration shape of the main pump;

[0036] A calculation module, used for determining the frequency and stiffness parameters of the vibration absorber according to the horizontal natural frequency;

[0037] The verification module is used to simulate and verify the vibration reduction effect of the main pump, and when the vibration reduction effect meets the requirements, determine the design parameters of the vibration absorber to complete the manufacture, verification and installation of the vibration absorber.

[0038] The present invention also provides an electronic device, which is characterized in that it includes: a processor and a memory, wherein the memory stores programs or instructions that can be run on the processor, and the programs or instructions are executed by the processor to implement the above-mentioned passive nuclear power plant main pump vibration reduction method.

[0039] The present invention also provides a readable storage medium, which is characterized in that the readable storage medium stores a program or instruction, and when the program or instruction is executed by a processor, the above-mentioned passive nuclear power plant main pump vibration reduction method is implemented.

[0040] The positive and progressive effects of the present invention are:

[0041] The passive nuclear power plant main pump vibration reduction method and system of the present invention completes the parameter demonstration of the dynamic vibration absorber through calculation and analysis, and connects the vibration absorber to the main pump through fasteners. Through this method, the low-frequency vibration energy of the main pump is transmitted to the vibration absorber, and the vibration absorber will exert a reaction force on the main pump. This force can offset most of the excitation load of the main pump, thereby reducing the overall vibration level of the main pump, and effectively solving the problem of the large vibration level of the main pump caused by external excitation loads.

[0042] The vibration reduction method of the present invention does not change the original structure and frequency of the main pump, does not affect the normal operation of the main pump, does not change the solidified nuclear power plant layout space, has low construction difficulty, and can minimize damage to the main pump during the long-term operation of the nuclear power plant. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] The above and other features, properties and advantages of the present invention will become more apparent through the following description in conjunction with the accompanying drawings and embodiments, in which:

[0044] Figure 1 It is a flow chart of the passive nuclear power plant main pump vibration reduction method of the present invention;

[0045] Figure 2 It is a schematic flow chart of the passive nuclear power plant main pump vibration reduction method of the present invention;

[0046] Figure 3 It is a schematic diagram of the knocking test system of the present invention;

[0047] Figure 4 This is a flow chart for verifying the vibration reduction effect of the present invention;

[0048] Figure 5 This is a mechanical analysis model diagram of the main pump coupling main circuit of the present invention;

[0049] Figure 6 This is a comparison diagram of the vibration reduction effect of the present invention;

[0050] Figure 7 This is a schematic diagram of the installation of the vibration absorber of the present invention;

[0051] Figure 8 for Figure 7 A comparison diagram of vibration reduction effects under the implementation methods;

[0052] Fig. 9 It is a schematic diagram of the structure of the electronic device of the present invention. DETAILED DESCRIPTION

[0053] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0054] Embodiments of the present invention will now be described in detail with reference to the accompanying drawings. Reference will now be made in detail to preferred embodiments of the present invention, examples of which are shown in the accompanying drawings. Wherever possible, the same reference numerals will be used in all drawings to represent the same or similar parts. In addition, although the terms used in the present invention are selected from well-known and commonly used terms, some of the terms mentioned in the specification of the present invention may be selected by the applicant at his or her discretion, and their detailed meanings are explained in the relevant parts of the description of this article. In addition, it is required to understand the present invention not only by the actual terms used, but also by the meaning implied by each term.

[0055] Reference Figure 1 and Figure 2 The present invention proposes a passive nuclear power plant main pump vibration reduction method, comprising:

[0056] S1. Obtain the original design parameters of the main pump and determine the weight, damping ratio and installation and fastening scheme of the shock absorber.

[0057] Among them, the weight of the shock absorber is determined by the wet weight information of the main pump.

[0058] It can be seen that increasing the mass ratio of the shock absorber to the main pump can improve the vibration reduction effect, but it will also cause the main pump and main circuit system to have excessive additional mass, affecting the load distribution and operation of the equipment and system.

[0059] It should be noted that for the third-generation passive nuclear power plant, the optimal mass ratio μ of the vibration absorber weight m2 and the main pump wet weight m1 is between 0.013 and 0.015. Within this range, the installation of the vibration absorber can meet the vibration reduction effect requirements without increasing the weight of the main pump too much and affecting the natural frequency and vibration mode of the main pump.

[0060] According to the principle of damped vibration absorbers, the vibration absorber will add two resonance peaks to the left and right of the resonance frequency while reducing the amplitude at the resonance frequency. The resonance peaks of different damping ratios are different, and the vibration reduction effect is also different. In order to ensure that the vibration absorber has a good vibration reduction effect in a wide frequency range, the vibration reduction frequency and vibration reduction range are taken into consideration, so that the newly added resonance peaks are equal and the highest point of the resonance peaks under various damping ratios.

[0061] The vibration of the main pump is a broadband vibration, and there is vibration contribution in the range of -1Hz-+1Hz near the vibration frequency, so damping materials can be used. Among them, the calculation formula for the optimal damping value of the vibration absorber damping element is as follows:

[0062]

[0063] Among them, ζ is the damping ratio, and μ is the mass ratio of the shock absorber weight m2 and the main pump wet weight m1.

[0064] In the installation and fastening plan of the vibration absorber, the main pump material information and the main pump lifting hole size information are first obtained. The vibration absorber is connected to the main pump through fasteners and the main pump lifting holes. The pump body material information provides a reference for the selection of fastener materials.

[0065] In order to avoid the problem of fasteners getting stuck during the tightening process and reduce damage to the threaded holes, the fasteners and the pump body should not be made of the same material. The hardness of the fastener material can be higher than that of the pump body material.

[0066] The layout design of the vibration absorber fasteners is consistent with the main pump lifting holes. The length and thread form of the fastener threaded holes should match the lifting holes. The fasteners use double-headed studs to reduce damage to the threaded holes during installation and disassembly of the vibration absorber.

[0067] S2. Perform a tapping test on the main pump when it is filled with water to obtain the horizontal natural frequency and modal vibration shape of the main pump.

[0068] Reference Figure 3 It can be seen that the present invention adopts the hammer method to perform the main pump knocking test, installs an acceleration sensor on the main pump, uses a hammer head with appropriate hardness to hammer, measures the response of the measuring point position through the acceleration sensor, and performs force hammer excitation and data collection in two horizontal directions of the main pump in turn.

[0069] Since the main pump structure is large in size, the energy of the force hammer point excitation is difficult to excite all the main natural frequencies, so multiple positions can be selected for hammering separately.

[0070] Specifically, the knock test and measurement system consists of a force hammer, an acceleration sensor, a data acquisition and analysis system, etc. The knock test can obtain the frequency f of the main pump in the horizontal X and Y directions. x , f y .

[0071] S3. Determine the frequency and stiffness parameters of the vibration absorber based on the horizontal natural frequency.

[0072] To ensure the horizontal X and Y vibration reduction effect, the frequency of the vibration absorber in the X and Y directions should be consistent with the main pump frequency. Therefore, the stiffness of the vibration absorber in the X and Y directions is:

[0073] k x =(2πf x ) 2 m2;

[0074] k y =(2πf y ) 2 m2;

[0075] According to steps 1 to 3, the design parameters of the vibration absorber can be determined, including mass m2, damping ratio ζ and stiffness k. x, k y .

[0076] S4. Simulate and verify the vibration reduction effect of the main pump, and when the vibration reduction effect meets the requirements, determine the design parameters of the vibration absorber to complete the manufacture, verification and installation of the vibration absorber.

[0077] Specifically, it is mainly used to verify whether the design parameters of the vibration absorber meet the requirements. It also simulates and verifies the vibration reduction effect of the main pump and analyzes and verifies the influence of the main circuit mechanics.

[0078] Reference Figure 4 , a spring-damper system-concentrated mass module unit is added to the bottom of the main pump model in the mechanical analysis model of the main pump coupled main loop to simulate the shock absorber model, where the spring simulates the shock absorber stiffness, the damping coefficient simulates the shock absorber damping ratio, and the concentrated mass simulates the shock absorber mass.

[0079] If finite element software is used for modeling and analysis, the spring-damper unit can be used to directly set the stiffness and unit damping coefficient. The damping coefficient is calculated according to the following formula:

[0080]

[0081] Using the harmonic response analysis method or vibration time history analysis method, the calculation model can refer to Figure 5 , quantitatively analyze the vibration response of the bottom of the main pump before and after adding the vibration absorber model to the main pump to verify the vibration reduction effect.

[0082] The vibration absorber added to the main pump will affect the load distribution of the main circuit. It is necessary to re-evaluate the stress level of the main circuit under various operating conditions, add a dynamic vibration absorber model to the main pump model with excessive vibration, and carry out main pipeline stress assessment, functional assessment, support assessment, pre-breakage leakage assessment and main equipment takeover assessment.

[0083] If after analysis, the vibration reduction effect cannot meet the expectations or the main circuit mechanical analysis and assessment does not meet the requirements, it is necessary to adjust the mass and damping ratio in step 1 and re-evaluate the contents of step 4. If the requirements are met, the design of the vibration absorber is carried out.

[0084] That is, according to the design parameters of the vibration absorber obtained above, the manufacture, verification and installation of the vibration absorber can be completed in sequence.

[0085] When an earthquake occurs, the vibration absorbers and fasteners should maintain the integrity of the structure without causing unacceptable impact on the main pump. Therefore, it is possible to verify whether the vibration absorbers and fasteners meet the earthquake resistance requirements through analysis or testing.

[0086] In addition, fatigue tests or analysis methods can be used to verify that the vibration absorbers and fasteners can withstand vibration fatigue without damage during their service life and meet the life requirements.

[0087] The following is an example of the vibration exceeding the limit in the horizontal Y direction of the bottom of the main pump of the third-generation passive nuclear power plant under certain operating conditions, wherein:

[0088] The wet weight of the main pump m1=100.800kg, according to step 1, the mass of the vibration absorber m2 is 1.5kg, the mass ratio is 0.0148, and the vibration absorber damping ratio is 6%. The main pump body material is SA-336M F6NM, the Brinell hardness is 295, and the fastener material is SA-540MGr.B23 CL3, the Brinell hardness is 363.

[0089] Through the knocking test, the natural frequencies of the main pump coupling main circuit in the Y direction are obtained as f y =9.3Hz. The Y-direction stiffness and damping coefficient are k y =5121.723N / mm, c y =10.518N / (mm / s). Through harmonic response analysis, the vibration reduction effect of the vibration absorber is estimated as follows: Figure 6 As shown, the vibration speed near the 9.3Hz frequency is reduced from 25.3mm / s to 0.123mm / s, and the vibration reduction effect reaches more than 90%. The main circuit mechanical influence analysis verifies that this solution is acceptable.

[0090] According to the design parameter information, the vibration absorber is manufactured, verified and installed. The effect after the implementation of the plan is as follows Figure 7 As shown in the figure, the comparison of the data before and after the field measurement of vibration reduction is as follows: Figure 8 As shown in the figure, the vibration speed near 9.3Hz is reduced from 26.73mm / s to 3.667mm / s, and the vibration reduction effect reaches 86%. The vibration reduction effect is significant and the vibration level is within the limit. Due to manufacturing and installation deviations, there are usually deviations between the actual product parameters and the design parameters of the vibration absorber, resulting in a certain deviation between the actual vibration reduction effect and the vibration reduction effect estimated by the ideal state calculation model. A certain safety margin is considered during the implementation of the vibration reduction plan.

[0091] The present invention further proposes a passive nuclear power plant main pump vibration reduction system, which adopts the above passive nuclear power plant main pump vibration reduction method, and the vibration reduction system comprises:

[0092] An acquisition module is used to obtain the original design parameters of the main pump and determine the weight, damping ratio and installation and fastening scheme of the vibration absorber;

[0093] The test module is used to perform a tapping test on the main pump when it is filled with water to obtain the horizontal natural frequency and modal vibration shape of the main pump;

[0094] A calculation module, used for determining the frequency and stiffness parameters of the vibration absorber according to the horizontal natural frequency;

[0095] The verification module is used to simulate and verify the vibration reduction effect of the main pump, and when the vibration reduction effect meets the requirements, determine the design parameters of the vibration absorber to complete the manufacture, verification and installation of the vibration absorber.

[0096] In summary, the passive nuclear power plant main pump vibration reduction method and system of the present invention completes the parameter demonstration of the dynamic vibration absorber through calculation and analysis, and connects the vibration absorber to the main pump through fasteners. Through this method, the low-frequency vibration energy of the main pump is transmitted to the vibration absorber, and the vibration absorber will exert a reaction force on the main pump. This force can offset most of the excitation load of the main pump, thereby reducing the overall vibration level of the main pump, and effectively solving the problem of the large vibration level of the main pump caused by the external excitation load.

[0097] The present invention does not change the original structure and frequency of the main pump, does not affect the normal operation of the main pump, does not change the layout space of the solidified nuclear power plant, has low construction difficulty, and can minimize damage to the main pump during the long-term operation of the nuclear power plant.

[0098] Reference Fig. 9 The present invention further provides an electronic device 900, comprising: a processor 901 and a memory 902, wherein the memory 902 stores a program or instruction that can be run on the processor 901, and the program or instruction is executed by the processor 901 to implement the above-mentioned passive nuclear power plant main pump vibration reduction method. When the program or instruction is executed by the processor 901, each process of the above-mentioned passive nuclear power plant main pump vibration reduction method implementation method is implemented, and the same technical effect can be achieved. To avoid repetition, it is not described here.

[0099] The present invention also provides a readable storage medium, on which a program or instruction is stored, and when the program or instruction is executed by a processor, the above-mentioned passive nuclear power plant main pump vibration reduction method is implemented. When the program or instruction is executed by the processor, each process of the above-mentioned passive nuclear power plant main pump vibration reduction method implementation method is implemented, and the same technical effect can be achieved. In order to avoid repetition, it will not be repeated here.

[0100] For those skilled in the art, the above invention disclosure is only used as an example and does not constitute a limitation of the present application. Although not explicitly stated herein, those skilled in the art may make various modifications, improvements and amendments to the present application. Such modifications, improvements and amendments are suggested in the present application, so such modifications, improvements and amendments still belong to the spirit and scope of the exemplary implementation of the present application.

[0101] At the same time, the present application uses specific words to describe the embodiments of the present application. For example, "one embodiment", "an embodiment", and / or "some embodiments" refer to a certain feature, structure or characteristic related to at least one embodiment of the present application. Therefore, it should be emphasized and noted that "one embodiment" or "an embodiment" or "an alternative embodiment" mentioned twice or more in different positions in this specification does not necessarily refer to the same embodiment. In addition, certain features, structures or characteristics in one or more embodiments of the present application can be appropriately combined.

[0102] Some aspects of the present application may be performed entirely by hardware, entirely by software (including firmware, resident software, microcode, etc.), or by a combination of hardware and software. The above hardware or software may be referred to as "data blocks", "modules", "engines", "units", "components" or "systems". The processor may be one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DAPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), processors, controllers, microcontrollers, microprocessors, or combinations thereof. In addition, various aspects of the present application may be expressed as computer products located in one or more computer-readable media, which include computer-readable program codes. For example, computer-readable media may include, but are not limited to, magnetic storage devices (e.g., hard disks, floppy disks, tapes ...), optical disks (e.g., compact disks CDs, digital versatile disks DVDs ...), smart cards, and flash memory devices (e.g., cards, sticks, key drives ...).

[0103] A computer-readable medium may include a propagated data signal containing computer program code, such as in baseband or as part of a carrier wave. The propagated signal may have a variety of manifestations, including electromagnetic, optical, etc., or a suitable combination. A computer-readable medium may be any computer-readable medium other than a computer-readable storage medium, which may be connected to an instruction execution system, device or apparatus to communicate, propagate or transmit a program for use. The program code on the computer-readable medium may be propagated via any suitable medium, including radio, cable, fiber optic cable, radio frequency signal, or similar medium, or any combination of the above mediums.

[0104] Similarly, it should be noted that in order to simplify the description of the disclosure of this application and thus facilitate the understanding of one or more embodiments of the invention, in the foregoing description of the embodiments of this application, multiple features are sometimes grouped into one embodiment, drawing or description thereof. However, this disclosure method does not mean that the subject matter of this application requires more features than those mentioned in the claims.

[0105] In fact, the features of the embodiments are less than all the features of the single embodiments disclosed above. In some embodiments, numbers describing the number of components and attributes are used. It should be understood that such numbers used in the description of the embodiments are modified by the modifiers "about", "approximately" or "substantially" in some examples.

[0106] Unless otherwise stated, "approximately", "approximately" or "substantially" indicates that the number allows a variation of ±20%. Accordingly, in some embodiments, the numerical parameters used in the specification and claims are approximate values, which may change according to the characteristics required by the individual embodiments. In some embodiments, the numerical parameters should take into account the specified significant digits and adopt the general method of retaining digits. Although the numerical domains and parameters used to confirm the breadth of their range in some embodiments of the present application are approximate values, in specific embodiments, the setting of such numerical values ​​is as accurate as possible within the feasible range.

[0107] Although the present invention is disclosed as above in terms of preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art may make possible changes and modifications without departing from the spirit and scope of the present invention. Therefore, any modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the scope of protection defined by the claims of the present invention.

Claims

1. A method for reducing vibration of a main pump of a passive nuclear power plant, characterized in that: include: Step 1: Obtain the original design parameters of the main pump and determine the weight, damping ratio and installation and fastening scheme of the vibration absorber; Step 2: Perform a tapping test on the main pump when it is filled with water to obtain the horizontal natural frequency and modal vibration shape of the main pump; Step 3, determining the frequency and stiffness parameters of the vibration absorber according to the horizontal natural frequency; Step 4: Simulate and verify the vibration reduction effect of the main pump, and when the vibration reduction effect meets the requirements, determine the design parameters of the vibration absorber to complete the manufacture, verification and installation of the vibration absorber.

2. The passive nuclear power plant main pump vibration reduction method according to claim 1, characterized in that: In the step 1, The weight information of the vibration absorber is determined according to the wet weight information of the main pump, the damping ratio of the vibration absorber is determined according to the mass ratio of the vibration absorber to the main pump, and the installation and fastening scheme of the vibration absorber is determined according to the material information of the main pump and the size information of the lifting hole.

3. The passive nuclear power plant main pump vibration reduction method according to claim 2, characterized in that: The optimal damping value calculation formula of the vibration absorber is as follows: Wherein, μ is the mass ratio of the vibration absorber to the main pump.

4. The passive nuclear power plant main pump vibration reduction method according to claim 1, characterized in that: In the step 2, By installing an acceleration sensor on the main pump and using a hammer test, the natural frequency f of the main pump in two directions is obtained. x , f y .

5. The passive nuclear power plant main pump vibration reduction method according to claim 4, characterized in that: The frequency of the vibration absorber in both directions is consistent with that of the main pump.

6. The passive nuclear power plant main pump vibration reduction method according to claim 4, characterized in that: The stiffness calculation formula of the vibration absorber in two directions is as follows: k x =(2πf x ) 2 m2; k y =(2πf y ) 2 m2; Wherein, m2 is the weight of the vibration absorber.

7. The passive nuclear power plant main pump vibration reduction method according to claim 1, characterized in that: In step 4, the main pump vibration reduction effect verification process includes: simulation verification of the main pump vibration reduction effect and analysis verification of the main circuit mechanics impact.

8. The passive nuclear power plant main pump vibration reduction method according to claim 7, characterized in that: The simulation verification process for the vibration reduction effect of the main pump includes: Step 41, establishing a finite element model for mechanical analysis of the main pump coupling main circuit; Step 42, adding a vibration absorber simulation model at the location where the vibration level of the main pump is the maximum; Step 43: Using the main pump outlet position as the vibration source input to calculate the vibration amplitude of the main pump.

9. The passive nuclear power plant main pump vibration reduction method according to claim 7, characterized in that: In the analysis and verification of the impact on the main circuit mechanics, a vibration absorber model is added to the main pump model with excessive vibration, and main pipeline stress assessment, functionality assessment, support assessment, pre-breakage leakage assessment and main equipment takeover assessment are carried out.

10. A passive nuclear power plant main pump vibration reduction system, characterized in that: The passive nuclear power plant main pump vibration reduction method according to any one of claims 1 to 9 is adopted, wherein the vibration reduction system comprises: An acquisition module is used to obtain the original design parameters of the main pump and determine the weight, damping ratio and installation and fastening scheme of the vibration absorber; The test module is used to perform a tapping test on the main pump when it is filled with water to obtain the horizontal natural frequency and modal vibration shape of the main pump; A calculation module, used for determining the frequency and stiffness parameters of the vibration absorber according to the horizontal natural frequency; The verification module is used to simulate and verify the vibration reduction effect of the main pump, and when the vibration reduction effect meets the requirements, determine the design parameters of the vibration absorber to complete the manufacture, verification and installation of the vibration absorber.

11. An electronic device, characterized in that: include: A processor and a memory, wherein the memory stores a program or instruction that can be run on the processor, and the program or instruction is executed by the processor to implement the passive nuclear power plant main pump vibration reduction method as described in any one of claims 1-9.

12. A readable storage medium, characterized in that: The readable storage medium stores a program or instruction, and when the program or instruction is executed by the processor, the passive nuclear power plant main pump vibration reduction method as described in any one of claims 1-9 is implemented.

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