Method for calculating vibration mode and harmonic response process of gas storage pressurization area pipeline

Abstract

The invention belongs to the field of gas storage safety evaluation, and particularly relates to a method for calculating the vibration mode and harmonic response process of a gas storage pressurization area pipeline. Comprising the following steps: dividing grids for a fluid domain and a solid domain of a three-dimensional model of a supercharged area pipeline and setting constraints; a pre-stress coupling wet mode method is adopted to carry out fluid-structure interaction statics analysis to obtain initial pre-stress, and then a multi-order vibration wet mode is calculated; and applying external excitation based on a wet mode result, and obtaining deformation and stress concentration conditions during vibration by using a direct complete harmonic response method. According to the method, multi-load coupling is considered, fine modeling is conducted on dangerous positions such as welding seams and supports and a high-pressure container, self-adaptive grid division and high-precision constraint are adopted, the pre-stress wet mode and a direct complete harmonic response analysis method are innovatively combined, the calculation accuracy is greatly improved, and the method is suitable for large-scale popularization and application. Powerful support is provided for design optimization, safety evaluation and maintenance of the pipeline in the pressurization area, the safety risk is reduced, and the system reliability is improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of gas storage safety evaluation, and particularly relates to a calculation method of mode shapes and harmonic response process of a pipeline in a pressurization area of a gas storage. BACKGROUND

[0002] An underground gas storage is an underground and ground integrated system for natural gas injection, storage and extraction. A pipeline system in a pressurization area of the injection station is a key hub connecting the underground reservoir and the ground transmission and distribution network, and bears the functions of high-pressure natural gas injection, storage and extraction. The pipeline in the pressurization area is long-term served in a high-pressure and variable working condition environment, and bears multiple coupling effects of support constraint prestress, high-pressure natural gas circumferential and axial stress, pipeline and fluid gravity vertical bending moment, and dynamic excitations such as compressor vibration and fluid pulsation, which is easy to induce resonance to cause weld cracking, support loosening and even pipeline rupture in the pressurization area, and threatens the safety of the energy supply chain.

[0003] The current vibration evaluation method for the pipeline in the pressurization area of the gas storage has significant defects: a single load is used for separate calculation, and the results are simply superimposed. For example, although the patent application with the publication number CN115659721A combines the beam model and the shell model and uses one-way fluid-structure coupling, a multi-load coupling framework is not established, and there is a large deviation from the actual working condition. In practice, the coupling effects of support prestress, high-pressure "rigidification effect" in the pipeline and gravity bending moment make the dynamic characteristics of the pipeline in the pressurization area have essential differences from those under the action of a single load, and the traditional method cannot capture this synergistic effect.

[0004] There are many simplifications and omissions in modeling accuracy: the weld is simplified as a smooth transition structure, and the local stress concentration caused by the weld reinforcement is ignored (most vibration fatigue failures originate from the weld toe); the support structure adopts a rigid constraint assumption, and the stiffness nonlinearity of the elastic support such as the rubber pad is not considered, such as the patent application with the publication number CN111881600A does not involve detailed modeling of the support, resulting in a large error in the transmission of prestress; the connection between the high-pressure container and the pipeline in the pressurization area is simplified as a rigid node, and the influence of the container weight on the stiffness matrix of the pipeline in the pressurization area is ignored, which may miss the key resonance risk.

[0005] The accuracy defects in the dynamics analysis link are prominent: the modal analysis does not consider the influence of the initial stress field, and the calculation in the unstressed state leads to a significant deviation of the high-order modal frequency; the harmonic response calculation mostly uses the modal superposition method (ignoring the modal damping coupling effect) rather than the complete method, such as the patent application with the publication number CN115374559A based on fluid-structure coupling equivalent analysis of the dynamic characteristics of the pipeline in the pressurization area, but the error of the resonance peak value is often large, and the position of the maximum deformation and stress concentration cannot be accurately predicted.

[0006] These defects result in the existing method vibration mode frequency error, vibration stress response calculation deviation is more than 40%, seriously restricts the safety evaluation and optimization design of the pressurized zone pipeline, and a high-precision calculation method of comprehensive fine modeling, multi-load coupling and accurate boundary condition is urgently needed to provide support for the whole life cycle safety management of the pressurized zone pipeline. SUMMARY

[0007] In view of the above problems, in a first aspect, the application provides a calculation method for the vibration mode and harmonic response process of the pressurized zone pipeline of the gas storage, comprising the following steps: The fluid domain and the solid domain of the three-dimensional model of the pressurized zone pipeline are meshed, and corresponding constraint conditions are set for the structure in the three-dimensional model of the pressurized zone pipeline; The initial prestress of the pressurized zone pipeline is obtained by using the prestressed coupled wet modal method for fluid-structure coupling static analysis, and the multi-order vibration wet modal of the pressurized zone pipeline is calculated based on the initial prestress by using the dynamic equation; Based on the analysis results of the multi-order vibration wet modal, the external excitation load matched with the actual working condition is applied, and the direct complete harmonic response method is used for dynamic analysis to obtain the deformation distribution and stress concentration of the pressurized zone pipeline during vibration.

[0008] Further, the three-dimensional model of the pressurized zone pipeline is a proportional model, which includes the geometric characteristics and connection mode of the weld, support and high-pressure container.

[0009] Further, the fluid domain is meshed by using tetrahedral mesh, and boundary layer mesh is set in the area close to the pipe wall; The solid domain is meshed by using hexahedral mesh as the main part and tetrahedral mesh as the auxiliary part, and local mesh refinement is performed at the weld, support and high-pressure container connection parts.

[0010] Further, the constraint conditions include elastic constraint at the hoop support, fixed constraint or displacement constraint at the flange, and elastic constraint of the wall surface and the ground.

[0011] Further, the elastic constraint at the hoop support is determined according to the following steps: The mechanical property data of the pressurized zone pipeline and the contact material of the hoop are collected, and a reaction force-deformation relationship calculation model between the hoop and the pressurized zone pipeline is established based on the mechanical property data; The pre-tightening force of a single bolt of the hoop is calculated according to the empirical formula of the pre-tightening force of carbon steel bolt; Based on the calculation results of the pre-tightening force, the extrusion stress distribution on the contact surface of the hoop and the pressurized zone pipeline is obtained by contact mechanics analysis to determine the normal pressure in the initial extrusion state. Based on X, Y, Z space coordinate axes, a single direction step-by-step displacement is applied to the pressurization zone pipeline in the initial extrusion state, the reaction force of the clamp to the pressurization zone pipeline is recorded, and the force-deformation curve in each direction is drawn; The stiffness coefficient in the corresponding coordinate axis direction is calculated through the linear segment slope of the force-deformation curve in each direction, and the stiffness coefficient is taken as the elastic constraint condition at the support of the clamp.

[0012] Further, the constraint type at the flange is determined according to the connection relationship of the flange, if the flange is in contact with the ground, wall surface or high-pressure container, a fixed constraint is applied, if the flange is suspended, a displacement constraint is applied.

[0013] Further, the prestressed coupled wet modal method is used to perform fluid-solid coupling static analysis to obtain the initial prestress of the pressurization zone pipeline, and on the basis of the initial prestress, the dynamics equation is used to calculate the multi-order vibration wet modal of the pressurization zone pipeline, including the following steps: Load the static load of the fluid and solid of the pressurization zone pipeline, the static load includes the fluid pressure in the pipeline, the fluid gravity, the gravity of the pressurization zone pipeline, and the pretightening force and friction resistance of the bolt of the support constraint; Based on the loaded static load, fluid-solid coupling static analysis is performed to calculate the initial prestress of the pressurization zone pipeline under the action of the static load; Map the initial prestress to the three-dimensional model of the pressurization zone pipeline, and use the dynamics equation to calculate the multi-order vibration wet modal of the pressurization zone pipeline.

[0014] Further, the fluid pressure in the pipeline is determined based on the actual conveying pressure; The fluid gravity is calculated based on the fluid density and the fluid volume in the pressurization zone pipeline; The gravity of the pressurization zone pipeline is calculated based on the material density and volume of the pressurization zone pipeline; The pretightening force of the bolt is calculated based on the yield strength of the bolt material and the stress cross-sectional area of the bolt.

[0015] Further, based on the analysis results of the multi-order vibration wet modal, an external excitation load matching the actual working condition is applied, and a complete harmonic response method is used for dynamic analysis to obtain the deformation distribution and stress concentration of the pressurization zone pipeline during vibration, including the following steps: Based on the natural frequency range in the multi-order vibration wet modal result, the frequency range and characteristics of the excitation load are determined, and the excitation load with corresponding characteristics is applied in the frequency range; According to the material and structural characteristics of the pressurization zone pipeline, the damping coefficient of the pressurization zone pipeline during normal operation matching the excitation frequency range is determined; Solve the dynamic equation by using the complete method based on the excitation load and vibration damping ratio, perform direct complete harmonic response calculation to determine the deformation distribution and stress distribution of the pressurization zone pipeline when vibrating; Extract the maximum deformation value of the pressurization zone pipeline and the stress concentration value of the dangerous area under the resonance frequency, analyze whether the maximum deformation value exceeds the safety limit value and whether the stress exceeds the material fatigue limit, and confirm the resonance risk.

[0016] Further, the excitation load satisfies the following formula:

[0017] In the formula, F(t) is the instantaneous load amplitude at time t; F0 is the load peak value; is the angular frequency, =2 f , f is the frequency; is the initial phase angle.

[0018] In a second aspect, the present application provides a system for calculating the vibration mode and harmonic response process of the pressurization zone pipeline of the gas storage, comprising: A mesh division and constraint setting module is configured to divide the fluid domain and the solid domain of the three-dimensional model of the pressurization zone pipeline into meshes, and set corresponding constraint conditions for the structure in the three-dimensional model of the pressurization zone pipeline; A fluid-structure coupling static and wet modal analysis module is configured to perform fluid-structure coupling static analysis by coupling fluid load and solid load by using the prestress coupling wet modal method, to obtain the initial prestress of the pressurization zone pipeline, and to calculate the multi-order vibration wet modal of the pressurization zone pipeline by using the dynamic equation; A complete harmonic response analysis and resonance evaluation module is configured to apply external excitation load matching the actual working condition, to perform dynamic analysis by using the direct complete harmonic response method, and to obtain the deformation distribution and stress concentration of the pressurization zone pipeline when vibrating.

[0019] Further, the system further comprises a three-dimensional model construction module configured to construct the three-dimensional model of the pressurization zone pipeline; The three-dimensional model of the pressurization zone pipeline is a scale model, comprising the geometric features and connection modes of the weld, support and high-pressure container.

[0020] In a third aspect, the present application provides an electronic device comprising a memory, a processor and a computer program stored on the memory and executable on the processor, wherein the processor implements the method for calculating the vibration mode and harmonic response process of the pressurization zone pipeline of the gas storage as described.

[0021] In a third aspect, the present application provides a computer program product comprising computer programs / instructions for implementing the method for calculating the vibration mode and harmonic response of the pressurized zone pipeline of the gas storage when executed by a processor.

[0022] The present application has the following beneficial effects: The present application takes into account the combined effects of the prestress of the support constraint at different positions of the pressurized zone pipeline, the pressure stress in the pipeline, the gravity of the pressurized zone pipeline and the fluid gravity, and fully considers the dangerous positions such as welds and supports and high-pressure containers such as oil filters and washing tanks in the modeling process, so that the calculation model is closer to the actual situation, and the accuracy of the calculation results is greatly improved.

[0023] The present application can reliably calculate the vibration mode and vibration response characteristics of the pressurized zone pipeline by using adaptive meshing technology and high-precision constraint condition setting, as well as strict calculation procedures. The calculation results can provide strong support for the design optimization, safety evaluation and maintenance of the pressurized zone pipeline of the gas storage injection station, effectively reduce the safety risks caused by the vibration of the pressurized zone pipeline, and improve the reliability of the conveying system.

[0024] The present application innovatively uses prestressed wet modal and complete harmonic response analysis. The prestressed wet modal analysis takes into account the pretightening force and friction resistance of the bolts, the initial stress field formed by the fluid gravity in the pipeline, the gravity of the pressurized zone pipeline and the fluid gravity, and the coupling effect of the fluid in the pipeline and the pressurized zone pipeline, accurately captures the inherent vibration characteristics of the pressurized zone pipeline under actual working conditions, and can identify the distortion of the vibration mode and the weak area caused by the prestress and the fluid. The complete harmonic response analysis directly solves the complete frequency domain dynamics equation, accurately simulates the dynamic response near the resonance frequency, and fully considers the modal coupling effect and complex boundary dynamic characteristics. The synergistic effect of the two greatly improves the accuracy of the calculation, provides reliable theoretical support for the safety evaluation, structure optimization and risk warning of the pressurized zone pipeline, and effectively reduces the faults and safety risks caused by vibration.

[0025] The present application loads multiple real loads during vibration mode calculation, accurately obtains the multi-order vibration mode distribution and frequency, accurately simulates the response of the pressurized zone pipeline under actual excitation during complete harmonic response calculation, can effectively find the deformation and stress during vibration, provides high-precision data support for the design optimization, fault diagnosis and safety evaluation of the pressurized zone pipeline, and can significantly improve the safety and stability of the operation of the pressurized zone pipeline of the gas storage injection station.

[0026] Other features and advantages of the present application will be set forth in the following description, and in part will become apparent to those skilled in the art from the description, or can be learned by practice of the present application. The objects and other advantages of the present application can be realized and obtained by the structure indicated in the specification, claims and drawings. BRIEF DESCRIPTION OF DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings described below are only some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor based on these drawings.

[0028] Figure 1 The flow chart of the calculation method of the vibration mode and harmonic response process of the pipeline in the pressurization zone of the gas storage in the embodiment of the present application; Figure 2 The detailed flow chart of step S2 in the embodiment of the present application; Figure 1 The detailed flow chart of step S22 in the embodiment of the present application; Figure 3 Figure 2 The detailed flow chart of step S3 in the embodiment of the present application; Figure 4 The detailed flow chart of step S4 in the embodiment of the present application; Figure 1 The deformation distribution graph and the strain distribution graph of the pipeline in the pressurization zone of the gas storage in the embodiment of the present application are shown respectively; Figures 5A-5B The first-order to tenth-order vibration mode deformation distribution graphs of the pipeline in the pressurization zone of the gas storage in the embodiment of the present application are shown respectively in the prestress wet modal analysis; Figures 6A-6J The frequency response curve graph of the pipeline in the pressurization zone of the gas storage in the embodiment of the present application is shown in the complete harmonic response analysis; Figure 7 Figure 1 The stress distribution and deformation distribution graphs of the pipeline in the pressurization zone of the gas storage in the embodiment of the present application are shown respectively in the complete harmonic response analysis at 14Hz; Figure 8 The schematic diagram of an electronic device in the embodiment of the present application is shown. DETAILED DESCRIPTION Figure 9A Figure 9B In order to make the purpose, technical solutions and advantages of the embodiments of the present application more clear, the technical solutions in the embodiments of the present application will be clearly and completely described below in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the protection scope of the present application. Figure 10 In order to make the purpose, technical solutions and advantages of the embodiments of the present application more clear, the technical solutions in the embodiments of the present application will be clearly and completely described below in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the protection scope of the present application.

[0029] In order to make the purpose, technical solutions and advantages of the embodiments of the present application more clear, the technical solutions in the embodiments of the present application will be clearly and completely described below in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the protection scope of the present application.

[0030] ​​​The embodiment of the present application provides a calculation method of a mode shape and a harmonic response process of a pipeline in a pressurization area of a gas storage, as shown in the following formula: Figure 1 The method comprises the following steps: S1: constructing a three-dimensional model of the pipeline in the pressurization area, wherein the three-dimensional model of the pipeline in the pressurization area comprises a weld structure, a support structure and structural features of a high-pressure container; S2: respectively performing mesh division on a fluid domain and a solid domain of the three-dimensional model of the pipeline in the pressurization area, and setting corresponding constraint conditions on structures in the three-dimensional model of the pipeline in the pressurization area; S3: performing fluid-solid coupling static analysis by using a prestress coupled wet modal method, obtaining initial prestress of the pipeline in the pressurization area, and combining with calculation of multi-order vibration wet modes of the pipeline in the pressurization area by using a dynamic equation on the basis of the initial prestress; S4: based on analysis results of the multi-order vibration wet modes, applying external excitation loads matched with actual working conditions, performing dynamic analysis by using a direct complete harmonic response method, and obtaining deformation distribution and stress concentration of the pipeline in the pressurization area in vibration.

[0031] In an embodiment of the present application, the three-dimensional model of the pipeline in the pressurization area in step S1 is established in proportion by using a three-dimensional modeling software according to actual sizes of the pipeline in the pressurization area. Specifically, the actual size data of the pipeline in the pressurization area comprises a pipe diameter, a wall thickness, a length, a support position, a weld position, a connection mode with the high-pressure container and the like. In an example, in the modeling process, the shape and size of the weld are accurately drawn, and a geometric model of the support structure is constructed; the connection parts of the high-pressure container (including an oil remover and a washing tank) and the pipeline in the pressurization area are accurately simulated, so that the model is ensured to be true and accurate.

[0032] In an embodiment of the present application, as shown in the following formula: Figure 2 The step S2 comprises the following steps: S21: respectively performing mesh division on a fluid domain and a solid domain of the three-dimensional model of the pipeline in the pressurization area; S22: setting constraint conditions on structures in the three-dimensional model of the pipeline in the pressurization area, including elastic constraints at the hoop support, fixed constraints or displacement constraints at the flange, and elastic constraints on the wall surface and the ground.

[0033] In step S21, the fluid domain is divided by using a tetrahedron mesh, and boundary layer meshes are set in the area close to the pipe wall. Local mesh encryption is performed on the area with large flow velocity variation and close to the pipe wall (for example, the elbow and the valve near the pipeline in the pressurization area), so that the mesh quality and the calculation accuracy are improved.

[0034] The solid domain is meshed primarily with hexahedral meshes, supplemented by tetrahedral meshes. The solid domain of the pressurized pipes includes, but is not limited to, the pipe itself, welds, support structures, and flanges. Local mesh refinement is performed at the connections between the welds and supports and the pressurized pipes to accurately simulate stress concentrations in these critical locations.

[0035] In step S22, the constraint condition at the clamp is determined by the stiffness coefficient at the clamp, and the stiffness coefficient at the clamp is determined, such as Figure 3 As shown, the following steps are included: S221: collecting mechanical property data of the pressurized area pipe and the clamp contact material, and establishing a reaction force-deformation relationship calculation model between the clamp and the pressurized area pipe based on the mechanical property data; S222: Calculate the preload force of a single bolt in a clamp based on the empirical formula for preload force of carbon steel bolts. S223: Based on the preload calculation result, obtain the extrusion stress distribution on the contact surface between the clamp and the pressurized area pipe through contact mechanics analysis to determine the positive pressure in the initial extrusion state; S224: Based on the X, Y, and Z spatial coordinate axes, a unidirectional step-by-step displacement is applied to the pressurized area pipe in the initial extrusion state, the reaction force of the clamp on the pressurized area pipe is recorded, and the force-deformation curve in each direction is drawn; S225: Calculate the stiffness coefficient (Kx, Ky, Kz) in the corresponding coordinate axis direction through the slope of the linear segment of the force-deformation curve in each direction, and use the stiffness coefficient as the elastic constraint condition at the clamp support.

[0036] In step S221, the materials in contact with the clamp include steel of the pressurized area pipeline and rubber pads; the mechanical performance data of the pressurized area pipeline include but are not limited to yield strength, tensile strength, elastic modulus, Poisson's ratio, elongation, and density.

[0037] In step S222, the empirical formula for the pre-tightening force of carbon steel bolts is as follows:

[0038] Where: is the preload force of a single bolt; is the yield strength of the bolt material, MPa; As is the stress cross-sectional area of ​​the bolt, .

[0039] In step S223, among the X, Y, and Z spatial coordinate axes, X is the axial direction of the pressurized zone pipe, Y is the horizontal radial direction, and Z is the vertical radial direction.

[0040] In one embodiment of the present invention, the specific process of step S224 is as follows: Apply upward Z-direction displacement (such as 0.1mm, 0.2mm, 0.3mm, which needs to be within the elastic deformation range) to the pressurized zone pipeline, and record the corresponding clamp reaction force (Z-direction reaction force Fz) for each displacement; Draw the Z-direction force-deformation curve, and draw the Y-direction force-deformation curve in the same way; Determine the friction coefficient between the pressurized zone pipeline and the rubber pad, apply X-direction displacement to the pressurized zone pipeline, at this time the reaction force includes the reaction force of the clamp and the friction force of the rubber pad, calculate the relationship between the X-direction displacement and the total reaction force (the reaction force of the clamp + the friction force of the rubber pad), and draw the X-direction force-deformation curve.

[0041] In step S2, the constraint at the flange is determined according to the position of the flange, which can be divided into two types: fixed constraint and displacement constraint.

[0042] If the flange is in contact with the ground or wall surface, a fixed constraint is applied, or the constraint at the flange connected to the high-pressure container is set as a fixed constraint, limiting its six degrees of freedom.

[0043] If the flange is suspended, the corresponding displacement constraint is applied. For example, for the flange connection in the middle of the pressurized zone pipeline, if the design allows a certain axial displacement to compensate for thermal expansion and other deformations, an axial displacement constraint is applied to allow radial and circumferential free deformation.

[0044] In step S2, the constraint of the pressurized zone pipeline on the wall surface and the ground is set as an elastic constraint.

[0045] In one embodiment of the present application, as shown in Figure 4 Step S3 includes the following steps: S31: Load the static load of the fluid and solid of the pressurized zone pipeline, which includes the fluid pressure in the pipe, the fluid gravity, the gravity of the pressurized zone pipeline, and the pre-tightening force and friction resistance of the bolt of the support constraint; S32: Perform fluid-structure coupling static analysis based on the loaded static load to calculate the initial pre-stress of the pressurized zone pipeline under the action of the static load; S33: Map the initial pre-stress to the three-dimensional model of the pressurized zone pipeline, and calculate the multi-order vibration wet mode of the pressurized zone pipeline by using the dynamic equation.

[0046] In step S31, the fluid pressure in the pipe is determined according to the actual conveying pressure, the fluid gravity is calculated according to the fluid density and the volume of the fluid in the pressurized zone pipeline; the gravity of the pressurized zone pipeline is calculated according to the material density and the volume of the pressurized zone pipeline; the pre-tightening force of the bolt is calculated based on the yield strength of the bolt material and the stress cross-sectional area of the bolt.

[0047] Wherein, the fluid density is calculated according to the following formula:

[0048] wherein: is the fluid density (kg / m 3 ); P is the absolute pressure (in Pa); M is the molar mass of the fluid (kg / mol), i.e. the molar mass of the gas being conveyed; Z is the compressibility factor, R is the gas constant (8.314 J / mol / K) , and T represents the thermodynamic temperature of the fluid (K).

[0049] In one embodiment of the application, the results of the calculation of step S32 are shown in Figures Figure 5A (deformation distribution) and Figure 5B (stress distribution). The results show that, under the action of fluid pressure, fluid gravity and the gravity of the pipeline in the booster zone, the maximum deformation is 1.02 mm, located at the bend of the pipeline at the outlet of the second stage of the compressor and at the bend of the pipeline from the air cooler to the oil separator; the maximum pre-stress is 70.014 MPa, located near the washing tank of the compressor, and the stress at the bend of the pipeline from the air cooler to the oil separator is 50.012 MPa, which needs to be paid attention to its impact on the long-term operation reliability of the pipeline.

[0050] The analysis results provide a clear direction for subsequent optimization, for example, for the deformation concentrated bend, the curvature radius can be optimized, a flow guide bushing can be added to reduce the effect of secondary flow; for the stress concentrated interface, a gradual transition section needs to be used, and the toughness of the welded joint needs to be strengthened, so as to weaken the peak value of the mechanical response from the aspect of structural design and improve the long-term operation reliability of the system.

[0051] In step S33, the multi-order vibration wet mode of the pipeline in the booster zone is calculated, including solving the natural frequency of the pipeline in the booster zone, so as to find out the resonance frequency of the pipeline in the booster zone, thereby avoiding the influence of the resonance frequency on the structure. For any pipeline in the booster zone, the dynamic equation is as follows:

[0052] wherein: is the mass matrix of the pipeline in the booster zone, reflecting the inertial characteristics of the pipeline in the booster zone, the fluid and the accessories; is the damping coefficient matrix of the pipeline in the booster zone; is the stiffness matrix of the pipeline in the booster zone, including the stiffness of the pipeline in the booster zone itself and the stiffness change caused by the initial pre-stress; represents displacement, represents velocity, represents acceleration, is the excitation load, t represents time, and the formula is the classical differential equation of motion of a multi-degree-of-freedom linear dynamic system (i.e. the dynamic equation), which describes the dynamic response of the structure of the pipeline in the booster zone under the influence of mass, damping and stiffness under the action of the excitation load .

[0053] In an embodiment of the present application, the first ten order modal distribution and frequency of the supercharged zone pipeline are calculated respectively, and the results are shown in Figs. 1 and 2 respectively. Figures 6A-6J As shown in Figs. 1 and 2, it can be seen that the first order vibration mode deformation is large at the elbow of the air cooler return pipeline, the second order vibration mode deformation is large at the elbow of the compressor second stage inlet pipeline, the third order vibration mode deformation is large at the elbow of the compressor second stage outlet pipeline, the fourth order vibration mode deformation is large at the elbow of the compressor first stage outlet pipeline, the fifth, sixth and ninth order vibration mode deformations are large at the valve of the air cooler return pipeline, the seventh and eighth order vibration mode deformations are large at the top of the scrubber tank, and the tenth order vibration mode deformation is large at the air cooler return pipeline.

[0054] In an embodiment of the present application, as shown in Fig. 3, step S4 comprises the following steps. Figure 7 S41: determining the frequency range and characteristics of the excitation load based on the natural frequency range in the multi-order vibration wet modal result, and applying the excitation load with the corresponding characteristics in the frequency range; S42: determining the damping coefficient of the supercharged zone pipeline in normal operation matched with the excitation frequency range according to the material and structural characteristics of the supercharged zone pipeline; S43: solving the dynamic equation based on the excitation load and the damping coefficient, performing direct complete harmonic response calculation, and determining the deformation distribution and stress distribution of the supercharged zone pipeline when vibrating; S44: extracting the maximum deformation value of the supercharged zone pipeline and the stress concentration value of the dangerous area at the resonance frequency, analyzing whether the maximum deformation value exceeds the safety limit value and whether the stress exceeds the material fatigue limit, and confirming the resonance risk.

[0055] In step S41, the basic formula of the excitation load is:

[0056] In the formula, F(t) is the instantaneous load amplitude at time t, F0 is the load peak value, ω is the angular frequency (rad / s), f is the frequency (Hz), and φ0 is the initial phase angle (rad). f

[0057] In step S42, the damping parameters can be determined by referring to the material manual or experimental data according to the material properties (such as carbon steel, alloy steel) and support structure types (such as metal support, rubber pad) of the supercharged zone pipeline.

[0058] In an embodiment of the present application, the frequency sweep response curve at the flange of the gas storage tank is extracted, and the amplitude and stress amplitude at the position can be obtained, as shown in Fig. 4. Figure 8 ​​​​​As shown in the figure, the resonance phenomenon occurs at the frequency of 14Hz at the flange of the gas storage tank. Figures 9A-9B As shown in the figure, when the frequency of vibration is 14Hz, the larger deformation of the pipeline is located at the bend of the second-stage outlet pipeline of the compressor, and the maximum deformation is 8.25mm; the larger stress of the pipeline is located at the base of the gas storage tank, and the maximum stress is 1950.1Mpa.

[0059] If the rotating speed of the compressor in the pressurization zone pipeline is 997r / min, the excited frequency of the compressor is 16.62Hz, which is close to the eighth and ninth order resonance frequencies, so the resonance risk is higher at the flange of the gas storage tank. If the modal analysis method is used, the vibration modal frequency of the pipeline system will be greatly reduced due to the neglect of the influence of fluid and prestress.

[0060] Through the above implementation steps, the vibration modal of the pressurization zone pipeline of the gas storage station and the vibration response characteristics under a specific excitation load can be accurately obtained, the calculation results are compared with the actual test data, the error is within 5%, and it is indicated that the calculation method has higher accuracy and reliability.

[0061] Based on the same inventive concept, a kind of vibration mode and harmonic response process calculation system of pressurization zone pipeline of gas storage is provided in the embodiment of the application, comprising: Three-dimensional model construction module is used to construct the three-dimensional model of pressurization zone pipeline, and the three-dimensional model of pressurization zone pipeline is a proportional model, including the geometric characteristics and connection mode of weld, support and high-pressure container.

[0062] Meshing and constraint setting module is used to mesh the fluid domain and solid domain of the three-dimensional model of pressurization zone pipeline respectively, and corresponding constraint conditions are set for the structure in the three-dimensional model of pressurization zone pipeline; Fluid-structure interaction static and wet modal analysis module is used to carry out fluid-structure interaction static analysis by using prestressed coupling wet modal method, to obtain the initial prestress of pressurization zone pipeline, and to calculate the multi-order vibration wet modal of pressurization zone pipeline by using dynamic equation based on the initial prestress. Complete harmonic response analysis and resonance evaluation module is used to apply external excitation load matched with actual working condition based on the analysis results of multi-order vibration wet modal, to carry out dynamic analysis by using direct complete harmonic response method, to obtain the deformation distribution and stress concentration when pressurization zone pipeline vibrates.

[0063] Another exemplary embodiment of the application provides an electronic device. As shown in the figure, Figure 10 The electronic device includes at least one processor 1001, at least one communication interface 1002, at least one memory 1003 and at least one communication bus 1004; wherein the processor 1001, the communication interface 1002 and the memory 1003 complete the communication among each other through the communication bus 1004; a memory 1003 storing a computer program; a processor 1001 configured to implement the method for calculating the mode shapes and harmonic response process of the gas storage booster pipeline when executing the program stored in the memory 1003.

[0064] Optionally, the communication interface can be an interface of a communication module, such as an interface of a GSM module; the processor can be a processor CPU, or an application specific integrated circuit ASIC, or one or more integrated circuits configured to implement the embodiments of the present application. The memory can include a high-speed RAM memory, and can also include a non-volatile memory, such as at least one disk memory. The memory stores a program, and the processor executes the program stored in the memory to implement some or all of the method embodiments described above.

[0065] Based on the same inventive concept, the embodiments of the present application also provide a computer readable storage medium storing a computer program, and the computer program is executed to implement some or all of the method embodiments described above. Optionally, the storage medium can be a non-transitory computer readable storage medium, such as a ROM, a random access memory (RAM), a CD-ROM, a magnetic tape, a floppy disk, and an optical data storage device, etc.

[0066] Based on the same inventive concept, the embodiments of the present application also provide a computer program product including computer programs / instructions, and the computer programs / instructions are executed by a processor to implement some or all of the method embodiments described above.

[0067] Although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that the technical solutions recorded in the foregoing embodiments can be modified, or some of the technical features can be replaced by equivalent features; and these modifications or replacements do not cause the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for calculating the vibration mode and harmonic response process of a pipeline in a pressurized area of ​​a gas storage reservoir, characterized in that: The following steps are involved: Meshing the fluid domain and solid domain of the three-dimensional model of the pressurized area pipeline separately, and setting corresponding constraints on the structure of the three-dimensional model of the pressurized area pipeline; Using the prestressed coupled wet modal method, a fluid-solid coupled statics analysis was performed to obtain the initial prestress of the pressurized area pipeline. Based on the initial prestress, the multi-order vibration wet modes of the pressurized area pipeline were calculated using dynamic equations. Based on the analysis results of multi-order vibration wet modes, external excitation loads matching the actual operating conditions were applied, and dynamic analysis was performed using the direct perfect harmonic response method to obtain the deformation distribution and stress concentration of the pressurized area pipeline during vibration.

2. The method for calculating the vibration mode and harmonic response process of the pipeline in the pressurized area of ​​the gas storage reservoir according to claim 1 is characterized in that: The three-dimensional model of the pressurized area pipeline is a scale model, including the geometric features and connection methods of the welds, supports and high-pressure vessels.

3. The method for calculating the vibration mode and harmonic response process of the pipeline in the pressurized area of ​​the gas storage reservoir according to claim 1 is characterized in that: The fluid domain is divided using tetrahedral grids, and a boundary layer grid is set in the area close to the pipe wall; The solid domain is divided mainly by hexahedral mesh and supplemented by tetrahedral mesh, and local mesh refinement is performed at welds, supports, and high-pressure vessel connection locations.

4. The method for calculating the vibration mode and harmonic response process of the pipeline in the pressurization area of ​​a gas storage reservoir according to any one of claims 1 to 3, characterized in that: The constraint conditions include elastic constraints at the clamp supports, fixed constraints or displacement constraints at the flanges, and elastic constraints at the walls and the ground.

5. The method for calculating the vibration mode and harmonic response process of the pipeline in the pressurized area of ​​the gas storage reservoir according to claim 4 is characterized in that: The elastic constraint at the clamp support is determined according to the following steps: Collecting mechanical property data of the pressurized area pipe and the contact material of the clamp, and establishing a reaction force-deformation relationship calculation model between the clamp and the pressurized area pipe based on the mechanical property data; Calculate the preload force of a single bolt of the clamp based on the empirical formula for preload force of carbon steel bolts; Based on the preload calculation results, the extrusion stress distribution on the contact surface between the clamp and the pressurized zone pipe is obtained through contact mechanics analysis to determine the positive pressure in the initial extrusion state; Based on the X, Y, and Z spatial coordinate axes, a unidirectional step-by-step displacement is applied to the pressurized area pipe in the initial extrusion state. The reaction force of the clamp on the pressurized area pipe is recorded, and the force-deformation curves in each direction are drawn. The stiffness coefficient in the direction of the corresponding coordinate axis is calculated by the slope of the linear segment of the force-deformation curve in each direction, and the stiffness coefficient is used as the elastic constraint condition at the clamp support.

6. The method for calculating the vibration mode and harmonic response process of the pipeline in the pressurized area of ​​a gas storage reservoir according to claim 1 is characterized in that: The constraint type at the flange is determined by the connection relationship of the flange. If the flange is in contact with the ground, wall, or high-pressure vessel, a fixed constraint is applied; if the flange is suspended in the air, a displacement constraint is applied.

7. The method for calculating the vibration mode and harmonic response process of the pipeline in the pressurized area of ​​a gas storage reservoir according to claim 1 is characterized in that: The method adopts the prestressed coupled wet modal method to perform fluid-solid coupled statics analysis to obtain the initial prestress of the pressurized area pipeline. Based on the initial prestress, the multi-order vibration wet modes of the pressurized area pipeline are calculated using dynamic equations, including the following steps: Applying static loads of fluid and solids to the pressurized area pipeline, the static loads including the fluid pressure in the pipe, the fluid gravity, the gravity of the pressurized area pipeline, and the pre-tightening force and friction resistance of the supporting and restraining bolts; Perform fluid-solid coupling static analysis based on the applied static load to calculate the initial prestress of the pressurized area pipeline under the static load; The initial prestress is mapped to a three-dimensional model of the pressurized area pipeline, and the multi-order vibration wet modes of the pressurized area pipeline are calculated using dynamic equations.

8. The method for calculating the vibration mode and harmonic response process of the pipeline in the boosting area of ​​a gas storage reservoir according to claim 7 is characterized in that: The pressure of the fluid in the pipe is determined based on the actual delivery pressure; The fluid gravity is calculated based on the fluid density and the volume of the fluid in the pressurized zone pipeline; The gravity of the pressurized area pipeline is calculated based on the density and volume of the pressurized area pipeline material; The pre-tightening force of the bolt is calculated based on the yield strength of the bolt material and the stress cross-sectional area of ​​the bolt.

9. The method for calculating the vibration mode and harmonic response process of the pipeline in the pressurized area of ​​a gas storage reservoir according to claim 1 is characterized in that: Based on the analysis results of the multi-order vibration wet mode, an external excitation load matching the actual working condition is applied, and a dynamic analysis is performed using the complete harmonic response method to obtain the deformation distribution and stress concentration of the boost zone pipeline during vibration, including the following steps: Based on the natural frequency range in the multi-order vibration wet modal results, the frequency range and characteristics of the excitation load are determined, and an excitation load with corresponding characteristics is applied within the frequency range; According to the material and structural characteristics of the pressurized area pipeline, determine the damping coefficient of the pressurized area pipeline during normal operation that matches the excitation frequency range; Solving the dynamic equation based on the excitation load and the damping coefficient, performing a direct fully harmonic response calculation, and determining the deformation distribution and stress distribution of the boost zone pipeline during vibration; Extract the maximum deformation value of the pressurized zone pipeline at the resonant frequency and the stress concentration value in the dangerous area, analyze whether the maximum deformation value exceeds the safety limit and whether the stress exceeds the material fatigue limit, and confirm the resonance risk.

10. The method for calculating the vibration mode and harmonic response process of the pipeline in the pressurized area of ​​a gas storage reservoir according to claim 9, characterized in that: The excitation load satisfies the following formula: Where: F(t) is the instantaneous load amplitude at time t; F0 is the peak load; is the angular frequency, =2 f , f is the frequency; is the initial phase angle.

11. A calculation system for vibration mode and harmonic response process of pipelines in the boosting area of ​​a gas storage reservoir, characterized in that: include: The meshing and constraint setting module is used to mesh the fluid domain and solid domain of the three-dimensional model of the pressurized area pipeline respectively, and set corresponding constraints on the structure in the three-dimensional model of the pressurized area pipeline; The fluid-solid coupling static and wet modal analysis module uses a prestressed coupled wet modal method to couple fluid loads and solid loads for fluid-solid coupling static analysis, obtain the initial prestress of the pressurized area pipeline, and calculate the multi-order vibration wet modes of the pressurized area pipeline using dynamic equations; The full harmonic response analysis and resonance assessment module is used to apply external excitation loads that match the actual operating conditions and perform dynamic analysis using the direct full harmonic response method to obtain the deformation distribution and stress concentration of the boost zone pipeline during vibration.

12. The calculation system for vibration mode and harmonic response process of pipelines in the pressurized area of ​​a gas storage reservoir according to claim 11, characterized in that: The system also includes a three-dimensional model building module for building a three-dimensional model of the pressurized area pipeline; The three-dimensional model of the pressurized area pipeline is a scale model, including the geometric features and connection methods of the welds, supports and high-pressure vessels.

13. An electronic device, characterized in that: The method comprises a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the method for calculating the vibration mode and harmonic response process of the pipeline in the boosting area of ​​the gas storage reservoir as described in any one of claims 1 to 10 is implemented.

14. A computer program product comprising a computer program / instructions, characterized in that When the computer program / instruction is executed by a processor, the method for calculating the vibration mode and harmonic response process of the pipeline in the pressurization area of ​​the gas storage reservoir according to any one of claims 1 to 10 is implemented.

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