Model selection method and device for fire-fighting pipeline compensator

Abstract

The invention provides a model selection method and device for a fire-fighting pipeline compensator, and relates to the technical field of fire-fighting engineering pipeline safety. The method comprises the following steps: establishing a pipeline fluid-structure coupling model based on a fire-fighting pipeline and an existing compensator; the static deformation quantity of an existing compensator is calculated through a pipeline fluid-structure coupling model; obtaining the pressure variation of the fire-fighting pipeline in unit time, and updating the static deformation quantity based on the pressure variation of the fire-fighting pipeline to obtain a dynamic deformation quantity; and determining the type of the compensator to be replaced according to the dynamic deformation quantity. According to the invention, accurate model selection of the compensator can be realized.

Description

Technical Field

[0001] This invention relates to the field of fire protection engineering pipeline safety technology, and in particular to a method and device for selecting fire protection pipeline compensators. Background Technology

[0002] The reliability of the fire protection system within a substation is directly related to the security of power supply and the stability of the social economy. Fire protection pipelines, as the key carriers for transporting fire extinguishing media (such as water and foam), are subjected to multiple dynamic loads over long periods, including high-temperature heat radiation, equipment vibration, and foundation settlement. This makes them prone to axial displacement, lateral deflection, and stress concentration, leading to leaks at pipe joints, weld cracks, and even pipe bursts, seriously threatening the integrity of the fire protection system. As a core component for regulating pipeline deformation, the scientific selection and design of compensators directly determine the long-term stability of the fire protection system.

[0003] However, traditional compensator selection methods mostly rely on the static design parameters of fire protection pipelines to determine the specifications and models of compensators, without considering the actual dynamic load inside the fire protection pipelines. This leads to a mismatch between static and dynamic operating conditions, resulting in a large deviation between the compensator selection and the actual operating conditions, which can easily cause leakage or fatigue failure. Summary of the Invention

[0004] This invention provides a method and apparatus for selecting fire-fighting pipeline compensators to solve the problem of large deviations between the selected compensator and actual working conditions.

[0005] In a first aspect, embodiments of the present invention provide a method for selecting a fire-fighting pipeline compensator, including:

[0006] Based on fire-fighting pipelines and existing compensators, a pipeline fluid-structure coupling model is established;

[0007] Using the aforementioned pipeline fluid-structure coupling model, the static deformation of the existing compensator is calculated;

[0008] The pressure change of the fire pipeline within a unit time is obtained, and the static deformation is updated based on the pressure change of the fire pipeline to obtain the dynamic deformation.

[0009] Based on the dynamic deformation, determine the type of compensator to be replaced.

[0010] Optionally, updating the static deformation variable based on the pressure change to obtain the dynamic deformation variable includes:

[0011] Obtain the fluid density and cross-sectional area of ​​the fire-fighting pipeline;

[0012] The dynamic adjustment value of deformation is determined based on the pressure change, the fluid density, and the cross-sectional area of ​​the fire-fighting pipeline;

[0013] The dynamic deformation variable is determined based on the dynamic adjustment value of the deformation variable and the static deformation variable.

[0014] Optionally, the pipeline fluid-structure coupling model includes the fluid viscosity coefficient;

[0015] Before calculating the static deformation of the existing compensator using the aforementioned pipeline fluid-structure coupling model, the following steps are also included:

[0016] The fluid viscosity coefficient in the pipeline fluid-structure coupling model is corrected by using a non-Newtonian fluid correction term, resulting in a corrected pipeline fluid-structure coupling model.

[0017] Optionally, the pipeline fluid-structure coupling model includes an elastic modulus;

[0018] Before calculating the static deformation of the existing compensator using the aforementioned pipeline fluid-structure coupling model, the following steps are also included:

[0019] Based on the elastic modulus, finite element simulation analysis was performed on the fire-fighting pipeline and the existing compensator to obtain simulation results at different measuring points in the finite element model.

[0020] The actual measurement results at different measuring points on the fire-fighting pipeline and the existing compensator are obtained accordingly.

[0021] An objective function is established with the goal of minimizing the error between the simulation results and the measured results, and the objective function is solved to determine the optimal elastic modulus.

[0022] Optionally, the simulation results include simulated displacement and simulated stress; the measured results include measured displacement and measured stress.

[0023] The objective function, which aims to minimize the error between the simulation results and the measured results, includes:

[0024] Calculate the displacement error term based on the simulated displacement and the measured displacement;

[0025] Calculate the stress error term based on the simulated stress and the measured stress;

[0026] The displacement error term and the stress error term are weighted and summed to determine the simulation deviation, and an objective function is established with the goal of minimizing the simulation deviation.

[0027] Optionally, determining the type of compensator to be replaced based on the dynamic deformation includes:

[0028] The type of compensator to be replaced is determined based on at least one of the pressure value of the fire-fighting pipeline, the diameter of the fire-fighting pipeline, the ambient temperature and the ambient humidity, the location of the fire-fighting pipeline and the dynamic deformation.

[0029] Optionally, the type of compensator to be replaced is determined based on at least one of the pressure value of the fire-fighting pipeline, the diameter of the fire-fighting pipeline, the ambient temperature and the ambient humidity, as well as the location of the fire-fighting pipeline and the dynamic deformation, including:

[0030] When the fire-fighting pipeline is located in an expansion joint or settlement joint area, if the dynamic deformation of the existing compensator is greater than or equal to the first preset deformation, the pressure value of the fire-fighting pipeline is greater than the first preset pressure value, and the pipe diameter of the fire-fighting pipeline is greater than the first preset pipe diameter value, then the type of compensator to be replaced is determined to be a corrugated compensator.

[0031] When the fire pipeline is in the branch pipeline temperature expansion zone, if the dynamic deformation of the existing compensator is less than or equal to the first preset deformation and greater than or equal to the second preset deformation, and the range of change of ambient temperature is within the first preset range of change, then the type of compensator to be replaced is determined to be a corrugated compensator or a natural bend compensator.

[0032] When the fire-fighting pipeline is located at a bend in an outdoor overhead pipeline or a long straight section of an outdoor overhead pipeline, if the dynamic deformation of the existing compensator is less than the second preset deformation and the ambient humidity is greater than the first preset humidity value, then the type of compensator to be replaced is determined to be a natural bend compensator or a stainless steel corrugated hose.

[0033] Optionally, after determining the type of compensator to be replaced based on the dynamic deformation, the method further includes:

[0034] If there is more than one type of compensator to be replaced, calculate the full life cycle cost of each type of compensator separately.

[0035] The compensator type with the lowest total lifecycle cost is determined as the type of compensator to be replaced last.

[0036] Optionally, the method further includes:

[0037] If all existing compensators on multiple fire-fighting pipelines need to be replaced, the replacement priority is determined based on the dynamic deformation of each existing compensator, and the existing compensators on each fire-fighting pipeline are replaced sequentially based on the replacement priority.

[0038] Secondly, embodiments of the present invention provide a selection device for fire-fighting pipeline compensators, comprising:

[0039] The modeling module is used to build a fluid-structure coupling model of the pipeline based on fire-fighting pipelines and existing compensators;

[0040] The calculation module is used for:

[0041] Using the aforementioned pipeline fluid-structure coupling model, the static deformation of the existing compensator is calculated;

[0042] The pressure change of the fire pipeline within a unit time is obtained, and the static deformation is updated based on the pressure change of the fire pipeline to obtain the dynamic deformation.

[0043] The selection module is used to determine the type of compensator to be replaced based on the dynamic deformation.

[0044] Thirdly, embodiments of the present invention provide an electronic device, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the method described in the first aspect or any possible implementation thereof.

[0045] Compared to existing technologies, this invention utilizes a pipeline fluid-structure coupling model to calculate and determine the static deformation of the compensator. Then, by collecting pressure changes in the fire-fighting pipeline and iteratively updating the static deformation, the dynamic deformation is determined, thereby identifying the appropriate compensator model to be replaced. Here, the pressure changes in the fire-fighting pipeline reflect the actual dynamic load inside the pipeline. This invention updates the static deformation determined by modeling calculations based on the actual dynamic load inside the fire-fighting pipeline, further determining the dynamic deformation under the influence of the actual dynamic load, and thus identifying the compensator model. This ensures that the compensator model matches the actual dynamic load of the fire-fighting pipeline, achieving accurate selection. Attached Figure Description

[0046] Figure 1 This is a structural schematic diagram of the fire-fighting pipeline and compensator provided in an embodiment of the present invention;

[0047] Figure 2 This is a flowchart illustrating the implementation of the selection method for fire-fighting pipeline compensators provided in this embodiment of the invention.

[0048] Figure 3 This is a schematic diagram of the selection device for fire pipeline compensators provided in an embodiment of the present invention;

[0049] Figure 4 This is a schematic diagram of an electronic device provided in an embodiment of the present invention. Detailed Implementation

[0050] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0051] For example, see Figure 1 Compensators are typically installed on fire protection pipelines to reduce stress on the pipelines, preventing them from bending, deforming, or even breaking due to stress, and ensuring the integrity and stability of the pipelines. Most related technologies rely on the static design parameters of the fire protection pipelines to determine the specifications and models of the compensators, without considering the actual dynamic loads inside the pipelines. This leads to a mismatch between static and dynamic operating conditions, resulting in a large deviation between the selected compensator and the actual operating conditions, which can easily cause leakage or fatigue failure.

[0052] To achieve accurate selection of compensators, this embodiment of the invention updates the static deformation determined by modeling calculations based on the actual dynamic load (i.e., pressure change) inside the fire-fighting pipeline. This determines the dynamic deformation under the influence of the actual dynamic load, thereby determining the compensator model. This ensures that the compensator model matches the actual dynamic load of the fire-fighting pipeline, achieving accurate selection.

[0053] See Figure 2 The flowchart illustrating the selection method for fire pipeline compensators provided in this embodiment of the invention is described in detail below:

[0054] Step 201: Based on the fire-fighting pipeline and existing compensators, establish a pipeline fluid-structure coupling model;

[0055] This invention provides an embodiment that can construct a pipe fluid-structure coupling model based on the Navier-Stokes equations and Hooke's law. Specifically:

[0056]

[0057] Where ρ represents the fluid density in the fire-fighting pipeline, u represents the fluid velocity vector, p represents the fluid pressure, μ represents the fluid viscosity coefficient, and F... s Δx represents the reaction force generated by the deformation of the compensator, k represents the stiffness coefficient of the compensator, Δx represents the static deformation of the compensator, n represents the unit vector of the deformation direction, E represents the elastic modulus, A represents the effective cross-sectional area of ​​the compensator, and L represents the length of the compensator.

[0058] In some embodiments, before calculating the static deformation of an existing compensator using a pipeline fluid-structure coupling model, the fluid viscosity coefficient in the pipeline fluid-structure coupling model can be corrected in advance using a non-Newtonian fluid correction term to obtain a corrected pipeline fluid-structure coupling model, so that the static compensation amount can be calculated based on the corrected pipeline fluid-structure coupling model.

[0059] This invention employs the k-ε turbulence model to apply the Navier-Stokes equations in the pipe fluid-structure coupling model. A closed loop is constructed, and a non-Newtonian fluid correction term is introduced to correct for the fluid viscosity coefficient μ. The specific correction formula is as follows:

[0060]

[0061] Where μ' represents the corrected fluid viscosity coefficient, μ0 represents the reference viscosity, γ represents the shear rate, γ0 represents the reference shear rate, and n' represents the exponent, the specific value of which can be determined experimentally.

[0062] In the Navier-Stokes equations, introducing a non-Newtonian fluid correction term typically means replacing the fluid viscosity coefficient μ with the shear rate-dependent function described above. This transforms the Navier-Stokes equations into nonlinear equations, whose solutions depend on the non-Newtonian properties of the fluid.

[0063] In other embodiments, temperature data can be acquired in real time, and the fluid viscosity coefficient can be corrected based on the acquired temperature data. Specifically, when correcting the fluid viscosity coefficient for temperature, the temperature correction coefficients corresponding to the fluid viscosity coefficients at different temperatures can be pre-stored in a Field Programmable Gate Array (FPGA) lookup table to reduce the amount of real-time computation.

[0064] Step 202: Calculate the static deformation of the existing compensator using the pipeline fluid-structure coupling model;

[0065] In solving the above-mentioned pipeline fluid-structure coupling model, the embodiment of the present invention can be solved by finite element modeling and simulation, thereby determining the static compensation amount.

[0066] In the finite element mesh generation process, a hexahedral structured mesh is used in the peak region of the compensator, with boundary layers set along the circumferential / axial direction for mesh densification. The mesh density is three times that of the conventional region (reference size ≤ D / 30), and the aspect ratio is controlled to be ≤ 5:1. The trough region of the compensator can use a tetrahedral unstructured mesh with a gradually changing size transition zone (transition ratio 1:1.5) to smoothly connect with the peak densification zone. The hexahedral mesh size in the conventional region is ≤ D / 10, and the mesh size in the peak densification zone is ≤ D / 30. The maximum aspect ratio across the entire region is checked by mesh skewness (skewness < 0.7). Here, D represents the nominal pipe diameter, and its ratio to the compensator length L (L = 3D) is maintained to ensure standardized mesh density.

[0067] In addition, the crest boundary layer grid density needs to match the pressure sensor layout density to ensure that the spatial gradient measurement resolution of the collected pressure data of the fire pipeline is consistent with the grid scale.

[0068] The hexahedral structured mesh (reference size ≤ D / 30) is directly related to the calculation of the static deformation Δx in the above-mentioned pipeline fluid-structure coupling model. This embodiment of the invention, by refining the mesh in the crest boundary region of the compensator, can accurately capture the force of fluid shear stress on the compensator, avoiding errors in fluid-structure interaction forces caused by excessively coarse meshes.

[0069] In this embodiment of the invention, a tetrahedral unstructured mesh (transition ratio 1:1.5) is used to meet the closure requirements of the k-ε turbulence model. The gradual transition reduces the numerical instability caused by abrupt changes in the shear rate γ in the non-Newtonian fluid correction term. The hexahedral mesh size ≤D / 10 in the conventional region (≤D / 30 in the crest region) provides a stable spatial discrete basis for solving the static compensation.

[0070] This invention employs FPGA acceleration technology for finite element analysis. Here, FPGA acceleration decomposes the Jacobian matrix used in the solution process into four sub-matrices and utilizes a Digital Signal Processor (DSP) module for parallel computation, thereby improving the solution speed. Furthermore, the regularity of the structured mesh accelerates the Jacobian matrix decomposition, further enhancing the solution speed and shortening the single iteration time to ≤1ms.

[0071] Step 203: Obtain the pressure change of the fire pipeline within a unit time, and update the static deformation based on the pressure change of the fire pipeline to obtain the dynamic deformation.

[0072] The embodiments of the present invention can set up pressure sensors to collect fire pipeline pressure in real time, and use edge computing terminals to perform Kalman filtering on the collected pressure data to reduce data noise.

[0073] The Kalman filtering process is briefly described below:

[0074] Establish the state transition equation: x k+1 =A'x k +Bu k +w k ;

[0075] Establish the observation equation: z k+1 =Hx k +v k ;

[0076] Where, x k+1 Let A' represent the state vector at time k+1, i.e., the pressure in the fire-fighting pipeline, and let x represent the state transition matrix. k Let B represent the state vector at time k, and let u represent the input matrix. k Let w represent the input vector at time k. kZ represents the state noise at time k. k+1 This represents the sensor measurement at time k+1, i.e., the actual pressure data collected. H represents the observation matrix, and v k This represents the observation noise at time k.

[0077] Based on the above state transition equation and observation equation, Kalman filtering is applied to the collected pressure data for noise reduction. The filtering equation can be expressed as:

[0078]

[0079] in, This represents the optimal estimate at time k, i.e., the fire pipeline pressure after Kalman filtering. This represents the pressure data at time k predicted from the pressure data at time k-1, where K is the pressure data at time k-1. k Indicates the Kalman gain, z k This represents the sensor measurement value at time k.

[0080] In this embodiment of the invention, after filtering and reducing noise in the pressure data using the Kalman filter algorithm, the pressure change of the fire pipeline per unit time can be calculated based on the filtered and denoised pressure data. Then, the static deformation variables are updated based on the pressure change variables to determine the dynamic deformation variables.

[0081] In some embodiments, the fluid density and cross-sectional area of ​​the fire-fighting pipeline can be obtained first; then, the dynamic adjustment value of the deformation can be determined based on the pressure change, fluid density, and cross-sectional area of ​​the fire-fighting pipeline; finally, the dynamic deformation can be determined based on the dynamic adjustment value of the deformation and the static deformation.

[0082] The specific calculation formula can be expressed as follows:

[0083]

[0084] Where ΔL represents dynamic deformation, Δx represents static deformation, β represents pressure change rate correction coefficient, ΔP represents pressure change, ρ represents fluid density, A represents fire pipeline cross-sectional area, and Δt represents unit time step.

[0085] Step 204: Determine the type of compensator to be replaced based on the dynamic deformation.

[0086] In this embodiment of the invention, the type of compensator to be replaced can be determined based on at least one of the following: the pressure value of the fire-fighting pipeline, the diameter of the fire-fighting pipeline, the ambient temperature and the ambient humidity, as well as the location and dynamic deformation of the fire-fighting pipeline.

[0087] Specifically, when fire-fighting pipelines are located in expansion joint or settlement joint areas, if the dynamic deformation of the existing compensator is greater than or equal to the first preset deformation, the pressure value of the fire-fighting pipeline is greater than the first preset pressure value, and the pipe diameter of the fire-fighting pipeline is greater than the first preset pipe diameter value, then the type of compensator to be replaced is determined to be a corrugated compensator. The pressure resistance of a corrugated compensator is typically ≥2.5 MPa, and the displacement compensation is typically ≥100 mm. In addition, a lateral mechanical compensator can be used to address vertical deformation. Here, the first preset deformation, the first preset pressure value, and the first preset pipe diameter value can be determined according to the actual situation. For example, the first preset deformation can be 50 mm. The first preset pressure value can be 1.6 MPa. The first preset pipe diameter value can be a nominal diameter of 200 mm.

[0088] When the fire-fighting pipeline is located in the temperature expansion zone of a branch pipeline, if the dynamic deformation of the existing compensator is less than or equal to the first preset deformation and greater than or equal to the second preset deformation, and the ambient temperature variation range is within the first preset variation range, then the type of compensator to be replaced is determined to be a corrugated compensator or a natural bend compensator. Here, the corrugated compensator can achieve axial compensation. The natural bend compensator can save nearly 30% of the cost for outdoor overhead pipelines. For example, the second preset deformation can be 30mm. The first preset variation range can be ±30℃.

[0089] When fire-fighting pipelines are located at bends or long straight sections of outdoor overhead pipelines, if the dynamic deformation of the existing compensator is less than the second preset deformation and the ambient humidity is greater than the first preset humidity value, then the compensator to be replaced is determined to be a natural bend compensator or a stainless steel corrugated flexible hose. Specifically, the bending angle of the natural bend compensator is ≥30°, and the length of the stainless steel corrugated flexible hose can be 150–300 mm. For example, the first preset humidity value can be 80%.

[0090] For fire protection pipelines whose main pipelines pass through equipment rooms or important equipment areas, if the pressure value of the fire protection pipeline is ≥1.4MPa and the stress concentration factor is ≥3.0, then the type of compensator to be replaced is determined to be a double-hinged corrugated compensator. Additionally, it can be wrapped with plastic film to prevent contamination by debris.

[0091] For fire protection pipelines in areas with abrupt changes in indoor and outdoor temperature differences, if the temperature gradient is ≥40℃ / m and the thermal expansion coefficients of the pipe materials differ significantly, rubber expansion joints and double-sphere flexible joints can be used as replacement compensators. Here, the rubber expansion joint has a temperature resistance of ±50℃ and a service life ≥10 years. The double-sphere flexible joint has an axial compression capacity ≥50mm.

[0092] For fire-fighting pipelines located near control valve assemblies, if the pressure in the low-stress zone is ≤0.8 MPa, a rigid-supported flexible joint can be used as the compensator to be replaced. One flexible joint should be installed for every 4–5 rigid joints.

[0093] Based on the above selection rules, the types of compensators to be replaced on fire-fighting pipelines at different locations can be clearly identified. In some embodiments, if there is more than one type of compensator to be replaced, the total life cycle cost of each compensator type is calculated separately, and the compensator type with the lowest total life cycle cost is determined as the final compensator type to be replaced.

[0094] The formula for calculating the total life-cycle cost of a compensator can be expressed as:

[0095]

[0096] Where LCC represents the total lifecycle cost of the compensator, C initial Let T represent the initial cost, and C represent the lifespan in years. maintenance,t Let r represent the maintenance cost in year t, r represent the discount rate, and C represent the cost in year t. failure C represents the cost of failure. residual This represents the residual value.

[0097] Initial cost refers to the total cost of equipment procurement, installation, and commissioning. It is usually estimated by a detailed quotation provided by the equipment supplier or by obtaining the average price of similar equipment through market research, combined with specific installation and commissioning requirements.

[0098] Maintenance costs are the expenses incurred in maintaining and repairing equipment during operation. You can learn about the items and frequency of regular maintenance by consulting the equipment's maintenance manual; at the same time, you can analyze the changing trends of maintenance costs by combining historical maintenance records; in addition, you can refer to industry maintenance standards to ensure the rationality of maintenance costs.

[0099] Failure costs are the additional costs incurred due to equipment failure, including downtime losses, repair costs, and potential compensation expenses. By analyzing historical equipment failure records, we can understand the frequency and severity of failures; by combining this with equipment failure analysis reports, we can assess the impact of failures on production; and by referring to industry survey reports, we can understand the failure costs and preventative measures for similar equipment.

[0100] Residual value is the remaining value of equipment at the end of its useful life. The book value of equipment can be determined through depreciation calculations; simultaneously, the actual residual value can be assessed by combining used equipment market prices and industry appraisal reports.

[0101] Compared to existing technologies, this invention utilizes a pipeline fluid-structure coupling model to calculate and determine the static deformation of the compensator. Then, by collecting pressure changes in the fire-fighting pipeline and iteratively updating the static deformation, the dynamic deformation is determined, thereby identifying the appropriate compensator model to be replaced. Here, the pressure changes in the fire-fighting pipeline reflect the actual dynamic load inside the pipeline. This invention updates the static deformation determined by modeling calculations based on the actual dynamic load inside the fire-fighting pipeline, further determining the dynamic deformation under the influence of the actual dynamic load, and thus identifying the compensator model. This ensures that the compensator model matches the actual dynamic load of the fire-fighting pipeline, achieving accurate selection.

[0102] In some embodiments, before using the pipeline fluid-structure coupling model to solve for the static compensation amount, the elastic modulus in the pipeline fluid-structure coupling model can be optimized in advance to determine the optimal elastic model, and the optimal elastic modulus can be applied to the pipeline fluid-structure coupling model to solve for the static compensation amount.

[0103] Specifically, based on the elastic modulus, finite element simulation analysis can be performed on fire-fighting pipelines and existing compensators to obtain simulation results at different measuring points in the finite element model. Then, the actual measurement results at different measuring points on the fire-fighting pipelines and existing compensators can be obtained. An objective function can be established with the goal of minimizing the error between the simulation results and the actual measurement results, and the objective function can be solved to determine the optimal elastic modulus.

[0104] Finite element method (FEM) simulation analysis software can perform displacement and stress analysis on fire-fighting pipelines and compensators by meshing, and determine the simulation results of displacement and stress at different measuring points. This embodiment of the invention determines the optimal elastic modulus based on the error between the FEM simulation analysis results and the actual observation results. It should be noted that the elastic variable values ​​set by the user in the FEM simulation software can affect the simulation results.

[0105] In some embodiments, simulation results include simulated displacement and simulated stress; measured results include measured displacement and measured stress.

[0106] In this embodiment of the invention, when establishing the objective function, the displacement error term can be calculated based on the simulated displacement and the measured displacement; then, the stress error term can be calculated based on the simulated stress and the measured stress; subsequently, the displacement error term and the stress error term are weighted and summed to determine the simulation deviation, and the objective function is established with the goal of minimizing the simulation deviation.

[0107] The mathematical expression for the objective function can be represented as:

[0108]

[0109] Where f(E) represents the objective function when the elastic modulus is E, W u N represents the weighting coefficient of the displacement error term. u Indicates the number of displacement measurement points, u sim,i (E) represents the simulated displacement at the i-th displacement measurement point when the elastic modulus is E, u exp,i σ represents the measured displacement at the i-th displacement measuring point. u,i The standard deviation (W) represents the uncertainty of the measured displacement and is used to normalize the error. σ W represents the weighting coefficient of the stress error term. u +W σ =1, Nσ represents the number of stress measurement points, σ sim,j (E) represents the simulated stress at the j-th stress measurement point when the elastic modulus is E, σ exp,j σ represents the measured stress at the j-th displacement measuring point. σ,j This represents the uncertainty of the measured stress.

[0110] Here, the measured displacement can be acquired by a laser displacement gauge or recorded by a structural health monitoring system. The uncertainty of the measured displacement can be obtained from the sensor's accuracy specification or determined by statistical analysis of repeated experiments. The measured stress can be acquired by strain gauges or obtained from a materials mechanical property database. The uncertainty of the measured stress can be determined by the strain gauge calibration error. The weighting coefficients of the displacement error term and the stress error term can be calibrated using expert experience or optimization algorithms. The initial value of the elastic modulus can be obtained from a materials handbook, and its boundary values ​​are determined by physical constraints.

[0111] This invention also establishes boundary constraints to limit the physical range of the elastic modulus. The physical range of the elastic modulus can be set according to material properties; for fire-fighting pipelines, the physical range of the elastic modulus is typically 10. 9 ~10 11 Pa.

[0112] Based on the above objective function, this embodiment of the invention uses a Bayesian optimization process to determine the optimal elastic modulus. The optimization process is as follows:

[0113] 1. Initialize the prior distribution

[0114] Prior assumption: Assume that the elastic modulus follows a normal distribution P(E)~N(μ'0,σ'0) 2 ), where μ'0 is the initial estimate and σ'0 reflects the initial uncertainty.

[0115] Proxy Model Selection: In this embodiment of the invention, Gaussian Process Regression (GPR) can be used as the surrogate model. GPR establishes a probabilistic mapping relationship between the elastic modulus and the objective function value in the parameter space. It describes this relationship through the mean function and the covariance function (kernel function) and can provide an estimate of the uncertainty of the predicted value.

[0116] 2. Initial Sampling and Observation

[0117] Initial dataset: A small number of parameter combinations {E1, E2, ..., E} are obtained through Latin hypercube sampling or random sampling. n}, and calculate the corresponding objective function values ​​{f(E1), f(E2), ..., f(E)}. n )}.

[0118] Observation correction: If noise exists, it can be reduced by methods such as Kalman filtering.

[0119] 3. Iteratively update the posterior distribution

[0120] Bayesian inference: Based on new observational data (E n+1 ,f(E n+1 The posterior distribution is updated using Bayes' theorem: P(E|D)∝P(D|E)P(E), where P(E|D) represents the posterior distribution, P(D|E) represents the likelihood function, P(E) represents the prior distribution (the posterior distribution of the previous iteration or the initial prior distribution), and D is the historical observation dataset.

[0121] Proxy model update: The relationship between the parameters and the objective function is refitted by Gaussian process regression, and the mean function and covariance matrix of GRP are updated.

[0122] 4. Select the next set of candidate parameters

[0123] Acquisition Function: Selects the next optimal candidate point E based on the posterior distribution. n+1 The function is optimized using a random search method to determine the next set of parameters E. n+1 Specifically, a large number of candidate points can be generated in the parameter space, the acquisition function value of each point can be directly calculated, and the point with the highest score can be selected as the next parameter E. n+1 .

[0124] 5. Termination condition determination

[0125] Convergence criterion: When the change in the objective function is lower than a set threshold (e.g., |f(E)) n+1 )-f(E n The iterations terminate when the maximum number of iterations is reached (∣<∈). Here, ∈ represents a threshold value.

[0126] Output optimal parameters: extract the elastic modulus E corresponding to the mean or maximum posterior probability from the posterior distribution.

[0127] In this embodiment of the invention, Bayesian parameter correction is used to dynamically calibrate the elastic modulus, so that the estimation error of the elastic modulus is ≤3%.

[0128] In some embodiments, if all existing compensators on multiple fire-fighting pipelines need to be replaced, the replacement priority is determined based on the dynamic deformation of each existing compensator, and the existing compensators on each fire-fighting pipeline are replaced sequentially based on the replacement priority.

[0129] Specifically, it can be based on Determine replacement priorities;

[0130] Where Q represents the replacement priority, ΔL represents the dynamic deformation, and D allow This represents the allowable deflection threshold for the pipeline, taken as 5% of the pipe diameter. P represents the pressure of the fire-fighting pipeline. max This indicates the maximum pressure that the fire protection pipeline can withstand, and D represents the diameter of the fire protection pipeline. ref This indicates the reference pipe diameter, typically taken as 250mm (nominal diameter). F leakage F represents the historical leakage frequency within the monitoring period. total This indicates the total monitoring duration.

[0131] Here, the larger the Q value, the higher the replacement priority.

[0132] In other embodiments, the replacement priority can also be determined based on the location of the fire protection pipeline. This embodiment of the invention divides the location of the fire protection pipeline into six categories, which are listed in descending order of replacement priority: areas crossing expansion joints (i.e., areas crossing expansion joints and settlement joints), main pipeline equipment crossing areas (i.e., main pipelines crossing equipment rooms or important equipment areas), branch pipeline expansion areas (i.e., branch pipeline temperature expansion areas), areas of sudden temperature changes (i.e., areas of sudden indoor-outdoor temperature changes), control valve group areas (i.e., areas near control valve groups), and low-stress connection sections (i.e., outdoor overhead pipeline bends or long straight sections).

[0133] It should be understood that the sequence number of each step in the above embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0134] The following are device embodiments of the present invention. For details not described in detail, please refer to the corresponding method embodiments described above.

[0135] Figure 3The diagram shows a structural schematic of a selection device for a fire-fighting pipeline compensator according to an embodiment of the present invention. For ease of explanation, only the parts related to the embodiment of the present invention are shown, and are described in detail below:

[0136] like Figure 3 As shown, a selection device 3 for a fire pipeline compensator includes: a modeling module 31, a calculation module 32, and a selection module 33.

[0137] Modeling module 31 is used to establish a pipeline fluid-structure coupling model based on fire-fighting pipelines and existing compensators;

[0138] Calculation module 32 is used for:

[0139] The static deformation of the existing compensator is calculated using a pipeline fluid-structure coupling model.

[0140] The pressure change of the fire pipeline within a unit of time is obtained, and the static deformation is updated based on the pressure change of the fire pipeline to obtain the dynamic deformation.

[0141] Selection module 33 is used to determine the type of compensator to be replaced based on dynamic deformation.

[0142] Optional, calculation module 32, specifically used for:

[0143] Obtain the fluid density and cross-sectional area of ​​the fire-fighting pipeline;

[0144] The dynamic adjustment value of deformation is determined based on the pressure change, fluid density, and cross-sectional area of ​​the fire-fighting pipeline;

[0145] The dynamic deformation variable is determined based on the dynamic adjustment value of the deformation variable and the static deformation variable.

[0146] Optionally, the fluid-structure coupling model of the pipeline includes the fluid viscosity coefficient;

[0147] Calculation module 32 is also used for:

[0148] The fluid viscosity coefficient in the pipe fluid-structure coupling model is corrected by using a non-Newtonian fluid correction term, resulting in a corrected pipe fluid-structure coupling model.

[0149] Optionally, the fluid-structure coupling model of the pipeline includes the elastic modulus;

[0150] Calculation module 32 is also used for:

[0151] Based on the elastic modulus, finite element simulation analysis was performed on fire-fighting pipelines and existing compensators to obtain simulation results at different measuring points in the finite element model.

[0152] The actual measurement results at different measuring points on the fire-fighting pipeline and existing compensators were obtained accordingly.

[0153] An objective function is established with the goal of minimizing the error between simulation results and measured results. The objective function is then solved to determine the optimal elastic modulus.

[0154] Optionally, simulation results include simulated displacement and simulated stress; measured results include measured displacement and measured stress.

[0155] Calculation module 32 is specifically used for:

[0156] Calculate the displacement error term based on the simulated displacement and the measured displacement;

[0157] Calculate the stress error term based on the simulated stress and the measured stress.

[0158] The displacement error term and the stress error term are weighted and summed to determine the simulation deviation, and an objective function is established with the goal of minimizing the simulation deviation.

[0159] Optional, selection module 33, specifically used for:

[0160] The type of compensator to be replaced is determined based on at least one of the following: pressure value of the fire-fighting pipeline, diameter of the fire-fighting pipeline, ambient temperature and ambient humidity, as well as the location and dynamic deformation of the fire-fighting pipeline.

[0161] Optional, selection module 33, specifically used for:

[0162] When the fire pipeline is located in the expansion joint or settlement joint area, if the dynamic deformation of the existing compensator is greater than or equal to the first preset deformation, the pressure value of the fire pipeline is greater than the first preset pressure value, and the pipe diameter of the fire pipeline is greater than the first preset pipe diameter value, then the type of compensator to be replaced is determined to be a corrugated compensator.

[0163] When the fire pipeline is in the temperature expansion zone of the branch pipeline, if the dynamic deformation of the existing compensator is less than or equal to the first preset deformation and greater than or equal to the second preset deformation, and the range of change of the ambient temperature is within the first preset range, then the type of compensator to be replaced is determined to be a corrugated compensator or a natural bend compensator.

[0164] When the fire protection pipeline is located at a bend in an outdoor overhead pipeline or a long straight section of an outdoor overhead pipeline, if the dynamic deformation of the existing compensator is less than the second preset deformation and the ambient humidity is greater than the first preset humidity value, then the type of compensator to be replaced is determined to be a natural bend compensator or a stainless steel corrugated hose.

[0165] Optionally, selection module 33 is also used for:

[0166] If there is more than one type of compensator to be replaced, calculate the full life cycle cost of each type of compensator separately.

[0167] The compensator type with the lowest total lifecycle cost is determined as the type of compensator to be replaced last.

[0168] Optionally, selection module 33 is also used for:

[0169] If all existing compensators on multiple fire-fighting pipelines need to be replaced, the replacement priority is determined based on the dynamic deformation of each existing compensator, and the existing compensators on each fire-fighting pipeline are replaced sequentially based on the replacement priority.

[0170] The above-described device embodiments can be used to implement the above-described method embodiments, and their implementation principles and technical effects are the same as those of the above-described method embodiments, which will not be repeated here.

[0171] Figure 4 This is a schematic diagram of an electronic device provided in an embodiment of the present invention. For example... Figure 4 As shown, the electronic device 4 in this embodiment includes a processor 40 and a memory 41. The memory 41 stores a computer program 42. When the processor 40 executes the computer program 42, it implements the steps in the various method embodiments described above. Alternatively, when the processor 40 executes the computer program 42, it implements the functions of each module / unit in the various device embodiments described above.

[0172] For example, computer program 42 may be divided into one or more modules / units, which are stored in memory 41 and executed by processor 40 to complete the present invention. The one or more modules / units may be a series of computer program instruction segments capable of performing a specific function, which describe the execution process of computer program 42 in electronic device 4.

[0173] Electronic device 4 may include, but is not limited to, processor 40 and memory 41. Those skilled in the art will understand that... Figure 4 This is merely an example of electronic device 4 and does not constitute a limitation on electronic device 4. It may include more or fewer components than shown, or combine certain components, or different components. For example, electronic device 4 may also include input / output devices, network access devices, buses, etc.

[0174] For the sake of simplicity and clarity, only the above-described functional modules / units are used as examples. In practical applications, the functions described above can be assigned to different functional modules / units as needed. These modules / units can be implemented in hardware, software, or a combination of both.

[0175] In the above embodiments, the descriptions of each embodiment have their own emphasis. Parts not detailed or described in a particular embodiment can be referred to in the relevant descriptions of other embodiments. Unless otherwise specified or in conflict with logic, the terminology and / or descriptions between different embodiments are consistent and can be referenced interchangeably. Technical features in different embodiments can be combined to form new embodiments based on their inherent logical relationships.

[0176] The above-described embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included within the protection scope of the present invention.

Claims

1. A method for selecting fire-fighting pipeline compensators, characterized in that, include: Based on fire-fighting pipelines and existing compensators, a pipeline fluid-structure coupling model is established; Using the aforementioned pipeline fluid-structure coupling model, the static deformation of the existing compensator is calculated; The pressure change of the fire pipeline within a unit time is obtained, and the static deformation is updated based on the pressure change to obtain the dynamic deformation. Based on the dynamic deformation, determine the type of compensator to be replaced.

2. The selection method for fire pipeline compensators according to claim 1, characterized in that, The process of updating the static deformation variable based on the pressure change to obtain the dynamic deformation variable includes: Obtain the fluid density and cross-sectional area of ​​the fire-fighting pipeline; The dynamic adjustment value of deformation is determined based on the pressure change, the fluid density, and the cross-sectional area of ​​the fire-fighting pipeline; The dynamic deformation variable is determined based on the dynamic adjustment value of the deformation variable and the static deformation variable.

3. The selection method for fire pipeline compensators according to claim 1 or 2, characterized in that, The pipeline fluid-structure coupling model includes the fluid viscosity coefficient; Before calculating the static deformation of the existing compensator using the aforementioned pipeline fluid-structure coupling model, the following steps are also included: The fluid viscosity coefficient in the pipeline fluid-structure coupling model is corrected by using a non-Newtonian fluid correction term, resulting in a corrected pipeline fluid-structure coupling model.

4. The method for selecting a fire-fighting pipeline compensator according to claim 1 or 2, characterized in that, The pipeline fluid-structure coupling model includes an elastic modulus; Before calculating the static deformation of the existing compensator using the aforementioned pipeline fluid-structure coupling model, the following steps are also included: Based on the elastic modulus, finite element simulation analysis was performed on the fire-fighting pipeline and the existing compensator to obtain simulation results at different measuring points in the finite element model. The actual measurement results at different measuring points on the fire-fighting pipeline and the existing compensator are obtained accordingly. An objective function is established with the goal of minimizing the error between the simulation results and the measured results, and the objective function is solved to determine the optimal elastic modulus.

5. The method for selecting a fire-fighting pipeline compensator according to claim 4, characterized in that, The simulation results include simulated displacement and simulated stress; the measured results include measured displacement and measured stress. The objective function, which aims to minimize the error between the simulation results and the measured results, includes: Calculate the displacement error term based on the simulated displacement and the measured displacement; Calculate the stress error term based on the simulated stress and the measured stress; The displacement error term and the stress error term are weighted and summed to determine the simulation deviation, and an objective function is established with the goal of minimizing the simulation deviation.

6. The method for selecting a fire-fighting pipeline compensator according to claim 1 or 2, characterized in that, The step of determining the type of compensator to be replaced based on the dynamic deformation includes: The type of compensator to be replaced is determined based on at least one of the pressure value of the fire-fighting pipeline, the diameter of the fire-fighting pipeline, the ambient temperature and the ambient humidity, the location of the fire-fighting pipeline, and the dynamic deformation.

7. The method for selecting fire-fighting pipeline compensators according to claim 6, characterized in that, The type of compensator to be replaced is determined based on at least one of the following: pressure value of the fire-fighting pipeline, pipe diameter of the fire-fighting pipeline, ambient temperature and ambient humidity, as well as the location of the fire-fighting pipeline and the dynamic deformation, including: When the fire-fighting pipeline is located in an expansion joint or settlement joint area, if the dynamic deformation of the existing compensator is greater than or equal to the first preset deformation, the pressure value of the fire-fighting pipeline is greater than the first preset pressure value, and the pipe diameter of the fire-fighting pipeline is greater than the first preset pipe diameter value, then the type of compensator to be replaced is determined to be a corrugated compensator. When the fire pipeline is in the branch pipeline temperature expansion zone, if the dynamic deformation of the existing compensator is less than or equal to the first preset deformation and greater than or equal to the second preset deformation, and the range of change of ambient temperature is within the first preset range of change, then the type of compensator to be replaced is determined to be a corrugated compensator or a natural bend compensator. When the fire-fighting pipeline is located at a bend in an outdoor overhead pipeline or a long straight section of an outdoor overhead pipeline, if the dynamic deformation of the existing compensator is less than the second preset deformation and the ambient humidity is greater than the first preset humidity value, then the type of compensator to be replaced is determined to be a natural bend compensator or a stainless steel corrugated hose.

8. The method for selecting a fire-fighting pipeline compensator according to claim 7, characterized in that, After determining the type of compensator to be replaced based on the dynamic deformation, the process further includes: If there is more than one type of compensator to be replaced, calculate the full life cycle cost of each type of compensator separately. The compensator type with the lowest total lifecycle cost is determined as the type of compensator to be replaced last.

9. The method for selecting a fire-fighting pipeline compensator according to claim 1 or 2, characterized in that, The method further includes: If all existing compensators on multiple fire-fighting pipelines need to be replaced, the replacement priority is determined based on the dynamic deformation of each existing compensator, and the existing compensators on each fire-fighting pipeline are replaced sequentially based on the replacement priority.

10. A selection device for fire-fighting pipeline compensators, characterized in that, include: The modeling module is used to build a fluid-structure coupling model of the pipeline based on fire-fighting pipelines and existing compensators; The calculation module is used for: Using the aforementioned pipeline fluid-structure coupling model, the static deformation of the existing compensator is calculated; The pressure change of the fire pipeline within a unit time is obtained, and the static deformation is updated based on the pressure change of the fire pipeline to obtain the dynamic deformation. The selection module is used to determine the type of compensator to be replaced based on the dynamic deformation.

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