Deep-sea gate valve parameter optimization and performance detection method based on multi-physical field coupling

Abstract

The application discloses a deep-sea gate valve parameter optimization and performance detection method based on multi-physical field coupling and relates to the field of gate valve health management, and comprises the following steps: a multi-physical field coupling model comprising a deep-sea pressure field, an ocean current impact flow field, a seawater corrosion chemical field and a structural mechanics field is established; the multi-physical field coupling model is inputted with deep-sea related parameters, i.e., valve body related parameters, the valve body structure, the sealing assembly, the valve rod structure and the valve core shape of the gate valve are optimized and designed, and the value combination of each parameter is determined to generate several groups of candidate parameter schemes; and the multi-physical field coupling model covering the deep-sea pressure, the ocean current impact, the seawater corrosion and the structural mechanics is established, the comprehensive action of the deep-sea complex environment on the gate valve can be accurately mapped, the key parameters are inputted, the multi-performance index weight optimization function is combined with the constraint condition, and the scientific design of the key parameters of the valve body, the sealing assembly, the valve rod and the valve core can be realized.

Description

Technical Field

[0001] This invention relates to the field of gate valve health management technology, specifically to a method for optimizing parameters and testing the performance of deep-sea gate valves based on multi-physics coupling. Background Technology

[0002] Deep-sea gate valves are core control components for deep-sea oil and gas development and other operations, used to precisely control the flow of fluids such as oil, gas, and seawater within pipelines. They can withstand the high pressure, low temperature, and highly corrosive environment of the deep sea, and rely on a high-strength valve body and reliable sealing design to provide crucial assurance for the safe and stable operation of deep-sea systems.

[0003] The invention patent application with application number 202510682058.7 discloses a method for testing the sealing performance of a flat gate valve under high pressure differential conditions. This application aims to solve the problem that "in the case of a flat gate valve under high pressure differential conditions and in an environment that requires frequent opening and closing, the contact pressure of the sealing surface may be less than the fluid pressure difference on both sides of the gate during the opening or closing process, which may lead to macroscopic leakage (fluid force directly pushes open the sealing surface) or microscopic leakage (insufficient contact pressure of the sealing surface, which cannot flatten the microscopic unevenness of the surface (such as rough peaks and valleys), resulting in leakage through tiny gaps), and the high-speed jet generated by the medium through the gap of the sealing surface can easily cause cavitation wear, thereby affecting the sealing performance of the gate valve."

[0004] However, due to the application scenarios of deep-sea gate valves, their bodies are constantly subjected to the pressure of the deep sea, the impact pressure of ocean currents, the high corrosiveness of seawater, and the attachment of seabed organisms. Therefore, during the design phase of the gate valve, it is necessary to undergo rigorous performance testing to ensure its performance in later use.

[0005] To address this, we propose a method for optimizing deep-sea gate valve parameters and testing performance based on multi-physics coupling. Summary of the Invention

[0006] In view of the above-mentioned shortcomings of the existing technology, the present invention provides a method for optimizing the parameters and testing the performance of deep-sea gate valves based on multi-physics coupling, which can effectively solve the problems of the existing technology.

[0007] To achieve the above objectives, the present invention is implemented through the following technical solutions;

[0008] This invention discloses a method for optimizing parameters and testing the performance of deep-sea gate valves based on multiphysics coupling, including:

[0009] A multiphysics coupling model was established, incorporating deep-sea pressure, ocean current impact, seawater corrosion chemical, and structural mechanical fields. Inputting deep-sea pressure, ocean current velocity, seawater corrosive medium, valve body material parameters, sealing structure dimensions, valve stem structure parameters, and valve core shape parameters into the multiphysics coupling model, the key parameters of the gate valve's body structure, sealing components, valve stem structure, and valve core shape were optimized. The optimal combinations of parameter values ​​were determined to generate several candidate parameter schemes. A multiphysics coupling simulation platform for deep-sea gate valves was constructed, and the candidate parameter schemes were imported into the platform for simulation analysis. The stress, corrosion, fluid resistance, and biofouling characteristics of gate valves in deep-sea environments were studied, and three optimal parameter combinations were selected. Based on the simulation results, gate valve prototypes with the corresponding parameter combinations were prepared. A deep-sea simulation test device was built to simulate deep-sea pressure, ocean current impact, seawater corrosion, and biofouling environments. The gate valve prototypes were placed in the device for performance testing under a multiphysics coupling environment, and data on pressure resistance, impact resistance, corrosion resistance, and biofouling resistance were acquired simultaneously. The performance data were fed back to the multiphysics coupling model for parameter iterative optimization, and the optimal parameter combination for the gate valve was finally determined.

[0010] Furthermore, when establishing a multiphysics coupling model, it follows the following rules:

[0011] Using the deep-sea pressure field as the initial action field, the deep-sea pressure is converted into a uniformly distributed load on the valve body surface, which serves as the input boundary condition for the structural mechanics field. Based on the velocity distribution of the ocean current impact field, the impact force and torque of the fluid on the valve body, valve stem, and valve core are calculated and superimposed onto the load system of the structural mechanics field.

[0012] Establish a two-way coupling relationship between the seawater corrosion chemical field and the structural mechanical field:

[0013] First, the stress distribution of the valve body obtained from structural mechanics field calculations is used as a corrosion acceleration factor input into the seawater corrosion chemical field;

[0014] Secondly, the seawater corrosion chemical field acquires corrosion damage parameters in real time through corrosion sensors, including the corrosion depth on the valve body surface and the residual strength of the material in the corrosion area. The corrosion depth is used to proportionally correct the elastic modulus and yield strength of the valve body material in the structural mechanical field, while the residual strength of the material in the corrosion area is directly used as the core indicator for verifying the bearing capacity of the valve body in the structural mechanical field. If the residual strength of the material in any area is lower than the preset safety threshold, the corresponding structural parameters of that area will be re-optimized.

[0015] Key parameters of the biofilm layer are defined, including the layer thickness and density. In the ocean current impact field, the fluid resistance coefficient is corrected using the layer thickness as a variable. For every increase in the layer thickness by a preset value, the fluid resistance coefficient increases by a preset proportion. In the structural mechanics field, the mass of the biofilm layer is calculated based on its thickness and density. This mass is then converted into an additional uniformly distributed load acting on the attachment area of ​​the valve body surface. Simultaneously, based on this mass and its distribution on the valve body surface, the valve body's moment of inertia and mass distribution are corrected.

[0016] Furthermore, when optimizing the key parameters of the gate valve's body structure, sealing components, stem structure, and core shape, the optimization is accomplished using the following function:

[0017] ;

[0018] In the formula: This is a vector of key parameters, including valve body wall thickness, sealing surface width, valve stem diameter, and valve core curvature radius; These are the weighting coefficients for maximum equivalent stress, average corrosion rate, and fluid pressure difference. All are positive numbers, and their sum is 1; The maximum equivalent stress of the gate valve corresponding to the key parameter vector X; The average corrosion rate of the gate valve corresponding to the key parameter vector X; The key parameter vector X corresponds to the pressure difference between the inlet and outlet fluids of the gate valve;

[0019] In the optimization process, with The goal is to minimize the pressure while simultaneously satisfying constraints on the valve body material yield strength, the sealing surface contact pressure, and the fluid resistance coefficient.

[0020] Furthermore, the optimized design of the valve core shape parameters includes:

[0021] Streamlined profile design of valve core: With the goal of reducing ocean current impact resistance, the inlet and outlet ends of the valve core adopt a rounded transition. The radius of curvature of the rounded transition is determined according to the ocean current velocity range. The higher the velocity, the larger the radius of curvature.

[0022] Valve core sealing surface parameter design: The taper and width of the sealing surface match the structural parameters of the sealing assembly, so that the pressure distribution is uniform when the sealing surface contacts the sealing assembly, and the coefficient of variation of the contact pressure is less than the preset threshold.

[0023] Valve core internal flow channel design: The rate of change of the cross-sectional area of ​​the flow channel must be controlled within a preset range, and the surface roughness of the flow channel must be lower than the preset roughness.

[0024] Furthermore, the deep-sea gate valve multiphysics coupling simulation platform consists of a coupling calculation module, a preset simulation step size control logic, and a performance index calculation submodule;

[0025] The coupled calculation module supports real-time data interaction between deep-sea pressure field and structural mechanical field, dynamic parameter transfer between ocean current impact field and seawater corrosion chemical field, and coordinated correction of each field by biofilm parameters.

[0026] In the preset simulation step size control logic, a preset basic step size is used in the initial stage of simulation; when the rate of change of a parameter of a certain physical field is detected to exceed the preset threshold, the step size is automatically reduced to 1 / 5 to 1 / 3 of the preset basic step size.

[0027] The performance index calculation submodule automatically outputs the stress distribution cloud map, corrosion rate contour map, fluid resistance coefficient curve, and bio-attachment amount change curve of the gate valve based on the simulation data.

[0028] Furthermore, in the modeling process of the seawater corrosion chemical field, the parameter settings and dynamic simulation of the seawater corrosion medium are as follows:

[0029] The variation of chloride ion concentration in seawater with deep-sea depth is simulated: the chloride ion concentration increases by a preset ratio for each increase in depth; a seawater temperature gradient parameter is introduced: the temperature variation with depth is used as a correction term for corrosion rate calculation.

[0030] The corrosion rate in the seawater corrosion chemical field is expressed as: ;

[0031] In the formula; Here is the corrosion rate constant; This refers to the chloride ion concentration in seawater. This is the activation energy for the corrosion reaction; It is the ideal gas constant; The absolute temperature of seawater; This is the stress corrosion sensitivity coefficient; This represents the effective stress of the valve body.

[0032] Furthermore, when simulating and analyzing the biofouling characteristics of gate valves in a deep-sea environment, a nutrient concentration parameter is introduced into the ocean current impact field. The nutrient concentration is set according to the actual distribution pattern at different depths in the deep sea, serving as the basis for calculating the initial amount of biofouling. Then, a correlation model between the amount of biofouling and time is constructed.

[0033] In the initial stage, the amount of biological attachment increases linearly over time. When the amount of attachment reaches 80% of the preset saturation value, the growth rate decreases linearly until it approaches saturation.

[0034] Finally, the change in fluid resistance of the gate valve after bio-attachment is quantified: with the fluid resistance without bio-attachment as the benchmark, the fluid resistance coefficient increases by a preset proportion for each additional preset thickness of bio-attachment layer, and this resistance change is fed back to the structural mechanics field to correct the fluid load on the valve body.

[0035] Furthermore, the deep-sea simulation test device used to simulate deep-sea pressure, ocean current impact, seawater corrosion and biofouling environment consists of a pressure control module, an ocean current simulation module, a seawater corrosion simulation module, and a biofouling simulation module.

[0036] The pressure control module employs a staged pressurization method, with the pressurization rate adjusted based on the elastic modulus, yield strength, and Poisson's ratio of the gate valve prototype material.

[0037] When the material's elastic modulus is lower or its yield strength is smaller, the pressurization rate is reduced; when the material's elastic modulus is higher and its yield strength is greater, the pressurization rate is increased. At the same time, a pressure holding unit is set, and the holding time is set according to the performance testing requirements.

[0038] The ocean current simulation module constructs a three-dimensional ocean current field through several sets of evenly distributed adjustable speed thrusters. The speed and direction of the thrusters are independently controlled to simulate the changes in ocean current velocity and direction in different deep-sea areas.

[0039] The seawater corrosion simulation module is equipped with a recyclable seawater medium circulation system. The ion concentration and temperature in the medium are adjusted in real time, and the medium parameters are monitored in real time through sensors to ensure that the chemical field parameters of seawater corrosion inside the device are consistent with those in the simulation model.

[0040] The bio-attachment simulation module is used to set up a bio-inoculation unit in the test device, which can be connected to a preset type of deep-sea attachment organism. The temperature and nutrient concentration are simultaneously controlled to adapt to the environment for bio-attachment, simulating the attachment process of organisms on the surface of the gate valve prototype.

[0041] Furthermore, the operation for performance testing and acquisition of data on pressure resistance, impact resistance, corrosion resistance, and biofouling resistance under multiphysics coupling environments is as follows:

[0042] The surface pressure and internal chamber pressure of the gate valve prototype are collected in real time by a pressure sensor. The sampling frequency is set according to the pressure change rate. When the pressure change rate is less than the preset value, the sampling frequency is reduced to the preset base frequency. When the pressure change rate exceeds the preset value, the sampling frequency is increased by a preset ratio.

[0043] The vibration acceleration of the gate valve prototype under the impact of ocean currents is collected by an accelerometer, and the displacement of key parts of the valve body is collected by a displacement sensor. During the data acquisition process, abnormal values ​​caused by sensor noise are removed. The standard for judging abnormal values ​​is a preset multiple that exceeds the normal data range.

[0044] The corrosion current density on the surface of the gate valve prototype is collected by a corrosion sensor and then converted into corrosion rate. At the same time, the changes in ion concentration in the seawater medium are sampled and analyzed at a preset period.

[0045] Biofouling images of the surface of a gate valve prototype are periodically captured by a camera. The biofouling area and thickness are obtained based on image recognition. At the same time, the change in fluid resistance after biofouling is measured and used as an evaluation index for anti-biofouling performance.

[0046] Furthermore, when feeding performance data back to the multiphysics coupling model for parameter iterative optimization, the following applies:

[0047] The performance data obtained from the experiment is compared one by one with the simulation data output by the simulation platform, and the relative error between the two is calculated. If the relative error of a certain performance index exceeds a preset threshold, the physical field model parameters corresponding to that performance index are corrected.

[0048] For performance indicators with excessive relative error, locate their related parameters, adjust the parameter values ​​according to the error direction, and adjust the adjustment range by a preset proportion of the current value of the parameter.

[0049] When, after a preset number of iterations, the relative errors between the experimental and simulation data for all performance indicators are less than a preset threshold, and all performance indicators meet the design requirements for deep-sea gate valves, the iteration stops. If, after a preset number of iterations, there are still relative errors that do not meet the preset threshold, the coupling relationship of the multiphysics coupling model is readjusted, and the iteration continues.

[0050] Based on the performance indicators that did not meet the standards, locate the associated coupled field pairs;

[0051] For the coupled field pairs in the positioning, their parameter transfer coefficients are corrected:

[0052] ;

[0053] In the formula: These are the original transfer coefficients of the coupled field pairs A and B; This is relative error; This is the coefficient adjustment factor;

[0054] Reassign priority weights to each field coupling:

[0055] Let the original coupling priority weight vector be... These correspond to the coupling priorities of the pressure field, flow field, corrosion field, and structural mechanics field, respectively. The weights are adjusted according to the error proportion, increasing the weight of fields with excessive errors, while still satisfying the requirements after adjustment. , This represents the adjusted i-th weight;

[0056] Dynamic response trigger condition adjustment:

[0057] For a coupled field pair for positioning, determine the associated dynamic response trigger threshold type, and adjust the threshold based on the error level of the corresponding performance index of the field pair:

[0058] The higher the error level, the greater the downward adjustment of the trigger threshold. The adjustment process ensures that the trigger threshold remains within the range that conforms to the physical changes in the actual deep-sea environment. After adjusting the coupling relationship, the multiphysics coupling simulation platform is run again, and the corrected simulation data is output and compared with historical experimental data. If the error of a single coupled field pair drops to within the preset threshold, the next round of global iteration begins. If the target is still not met, the process of positioning the associated coupled field pair, correcting the parameter transfer coefficient, allocating the priority weight of each field coupling, and adjusting the dynamic response trigger conditions is repeated until the coupling relationship meets the expected accuracy requirements.

[0059] Compared with the known prior art, the technical solution provided by this invention has the following beneficial effects:

[0060] This invention provides a method for parameter optimization and performance testing of deep-sea gate valves based on multi-physics coupling. During execution, this method establishes a multi-physics coupling model encompassing deep-sea pressure, ocean current impact, seawater corrosion, and structural mechanics. This model accurately maps the comprehensive effects of the complex deep-sea environment on the gate valve. By inputting key parameters and combining them with constraints using a multi-performance index weighting optimization function, the method achieves scientific design of key parameters for the valve body, sealing components, valve stem, and valve core, generating high-quality candidate solutions. Simulation analysis allows for early assessment of gate valve stress, corrosion, fluid resistance, and biofouling characteristics, efficiently selecting the optimal parameter combination. Real performance data obtained through simulated deep-sea environment experiments is then fed back to the model for iterative optimization, correcting parameters and coupling relationships to ensure that parameter design closely matches actual operating conditions. The final determined optimal parameters enable the gate valve to possess excellent pressure resistance, impact resistance, corrosion resistance, and biofouling resistance, enabling it to stably adapt to complex deep-sea conditions, extending its service life, and reducing subsequent maintenance costs. Attached Figure Description

[0061] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are merely some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without any creative effort.

[0062] Figure 1 This is a flowchart illustrating a method for optimizing parameters and testing the performance of deep-sea gate valves based on multi-physics coupling. Detailed Implementation

[0063] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0064] The present invention will be further described below with reference to embodiments.

[0065] Example:

[0066] This embodiment presents a method for optimizing deep-sea gate valve parameters and testing performance based on multi-physics coupling, such as... Figure 1 As shown, it includes:

[0067] Establish a multi-physics coupled model that includes deep-sea pressure field, ocean current impact field, seawater corrosion chemical field, and structural mechanical field;

[0068] When establishing a multiphysics coupling model, the following rules apply:

[0069] Using the deep-sea pressure field as the initial action field, the deep-sea pressure is converted into a uniformly distributed load on the valve body surface, which serves as the input boundary condition for the structural mechanics field. Based on the velocity distribution of the ocean current impact field, the impact force and torque of the fluid on the valve body, valve stem, and valve core are calculated and superimposed onto the load system of the structural mechanics field.

[0070] Establish a two-way coupling relationship between the seawater corrosion chemical field and the structural mechanical field:

[0071] First, the stress distribution of the valve body obtained from structural mechanics field calculations is used as a corrosion acceleration factor input into the seawater corrosion chemical field;

[0072] Secondly, the seawater corrosion chemical field acquires corrosion damage parameters in real time through corrosion sensors, including the corrosion depth on the valve body surface and the residual strength of the material in the corrosion area. The corrosion depth is used to proportionally correct the elastic modulus and yield strength of the valve body material in the structural mechanical field, while the residual strength of the material in the corrosion area is directly used as the core indicator for verifying the bearing capacity of the valve body in the structural mechanical field. If the residual strength of the material in any area is lower than the preset safety threshold, the corresponding structural parameters of that area will be re-optimized.

[0073] Key parameters of the biofilm layer are defined, including layer thickness and density. In the ocean current impact field, the fluid resistance coefficient is corrected using layer thickness as a variable. For each increase in layer thickness by a preset value, the fluid resistance coefficient increases by a preset proportion. In the structural mechanics field, the mass of the biofilm layer is calculated based on its thickness and density. This mass is then converted into an additional uniformly distributed load acting on the attachment area of ​​the valve body surface. Simultaneously, based on this mass and its distribution on the valve body surface, the moment of inertia and mass distribution of the valve body are corrected. The corrected moment of inertia includes the torque contribution of the biofilm layer mass on the valve body's rotation axis, and the corrected mass distribution reflects the superposition relationship between the biofilm layer mass and the original mass of the valve body.

[0074] For the multiphysics coupling model, input deep-sea depth pressure, ocean current velocity, seawater corrosive medium, valve body material parameters, sealing structure size parameters, valve stem structure parameters, and valve core shape parameters, optimize the key parameters of the gate valve's valve body structure, sealing components, valve stem structure, and valve core shape, and determine the value combinations of each parameter to generate several sets of candidate parameter schemes;

[0075] When optimizing the key parameters of the gate valve's body structure, sealing components, stem structure, and core shape, the following function is used:

[0076] ;

[0077] In the formula: This is a vector of key parameters, including valve body wall thickness, sealing surface width, valve stem diameter, and valve core curvature radius; These are the weighting coefficients for maximum equivalent stress, average corrosion rate, and fluid pressure difference. All are positive numbers, and their sum is 1; X represents the maximum equivalent stress of the gate valve corresponding to the key parameter vector X, in MPa. The average corrosion rate of the gate valve corresponding to the key parameter vector X is expressed in mm / a. The pressure difference between the inlet and outlet fluids of the gate valve corresponding to the key parameter vector X, in MPa;

[0078] The above formula constructs a vector around key parameters such as valve body wall thickness and sealing surface width, and takes maximum equivalent stress, average corrosion rate and fluid pressure difference as core evaluation indicators. By setting positive weights and ensuring that the sum of the weights is 1, the importance of different performance indicators is reasonably allocated. The function takes the minimum value as the optimization objective, and strictly follows the constraints of valve body material yield strength, sealing surface contact pressure and fluid resistance coefficient. It not only comprehensively considers the overall performance of the gate valve under multiple physical fields, but also ensures the safety and reliability of parameter design through constraint conditions.

[0079] In the optimization process, with The objective is to minimize the pressure while simultaneously satisfying constraints on the valve body material yield strength, the sealing surface contact pressure, and the fluid resistance coefficient. The priority of gate valve operations in deep-sea operations is determined based on the following: if the operation scenario is deep-water well control, then... Value greater than If the work scenario involves deep-sea mining, then Value greater than If the operation scenario involves deep-sea oil and gas transportation, then Value greater than ;

[0080] Optimization design of valve core shape parameters, including:

[0081] Streamlined profile design of valve core: With the goal of reducing ocean current impact resistance, the inlet and outlet ends of the valve core adopt a rounded transition. The radius of curvature of the rounded transition is determined according to the ocean current velocity range. The higher the velocity, the larger the radius of curvature.

[0082] Valve core sealing surface parameter design: The taper and width of the sealing surface match the structural parameters of the sealing assembly, so that the pressure distribution is uniform when the sealing surface contacts the sealing assembly, and the coefficient of variation of the contact pressure is less than the preset threshold.

[0083] Valve core internal flow channel design: The rate of change of the cross-sectional area of ​​the flow channel must be controlled within a preset range, and the surface roughness of the flow channel must be lower than the preset roughness.

[0084] A multiphysics coupling simulation platform for deep-sea gate valves was constructed. Candidate parameter schemes were imported into the platform, and the stress, corrosion, fluid resistance and biofouling characteristics of the gate valves in the deep-sea environment were simulated and analyzed. The three sets of parameters with the best performance were then selected.

[0085] The deep-sea gate valve multiphysics coupling simulation platform consists of a coupling calculation module, a preset simulation step size control logic, and a performance index calculation submodule.

[0086] The coupled calculation module supports real-time data interaction between deep-sea pressure field and structural mechanical field, dynamic parameter transfer between ocean current impact field and seawater corrosion chemical field, and coordinated correction of each field by biofilm parameters.

[0087] In the preset simulation step size control logic, a preset basic step size is used in the initial stage of simulation; when the rate of change of a parameter of a certain physical field is detected to exceed the preset threshold, the step size is automatically reduced to 1 / 5 to 1 / 3 of the preset basic step size.

[0088] The performance index calculation submodule automatically outputs the stress distribution cloud map, corrosion rate contour map, fluid resistance coefficient curve, and bio-attachment amount change curve of the gate valve based on the simulation data.

[0089] In the modeling of the seawater corrosion chemical field, the parameter settings and dynamic simulation of the seawater corrosion medium are as follows:

[0090] The variation of chloride ion concentration in seawater with deep-sea depth is simulated: the chloride ion concentration increases by a preset ratio for each increase in depth; a seawater temperature gradient parameter is introduced: the temperature variation with depth is used as a correction term for corrosion rate calculation.

[0091] The corrosion rate in the seawater corrosion chemical field is expressed as: ;

[0092] In the formula; Here is the corrosion rate constant; This refers to the chloride ion concentration in seawater. This is the activation energy for the corrosion reaction; It is the ideal gas constant; The absolute temperature of seawater; This is the stress corrosion sensitivity coefficient; The effective stress of the valve body;

[0093] The above formula incorporates parameters such as corrosion rate constant, chloride ion concentration, corrosion reaction activation energy, ideal gas constant, seawater absolute temperature, stress corrosion sensitivity coefficient, and effective stress of valve body. It fully combines the chemical characteristics of seawater with the mechanical state of valve body, and takes into account the influence of chloride ion concentration and temperature on corrosion as they change with depth. By integrating these dynamic factors into the formula, the corrosion rate calculation can accurately reflect the actual situation in the deep sea environment. This overcomes the problem that traditional corrosion rate calculation ignores dynamic environmental changes and stress effects, and provides a more realistic quantitative basis for modeling seawater corrosion chemical field.

[0094] in, The value is determined based on the reactivity of the valve body material with the seawater medium. The range of values ​​is a preset basic range. The higher the reactivity of the valve body material with the seawater medium and the stronger the activity of corrosive ions in the seawater medium, the larger the value. The better the corrosion resistance of the valve body material and the weaker the corrosiveness of the seawater medium, the smaller the value. The value is determined by the reaction characteristics of the valve body material with the seawater medium, and the range is 40-200 J / mol. The larger the value is when the valve body material has stronger corrosion resistance and weaker reaction with the seawater medium, the smaller the value is when the valve body material has weaker corrosion resistance and stronger reaction with the seawater medium. Take 8.314 J / (mol·K) for the formula calculation. The value is determined by material stress corrosion testing based on the composition and microstructure of the valve body material. The value range is a preset interval, typically 0.001-0.01 MPa. -1 The higher the sensitivity of the valve body material to stress corrosion, the larger the value; the stronger the resistance of the valve body material to stress corrosion, the smaller the value. The values ​​are calculated by combining the structural mechanics field with the valve body structural parameters (such as wall thickness and valve stem diameter) and the uniformly distributed load of the deep-sea pressure field and the fluid impact force of the ocean current impact field. The values ​​fall within the preset range set according to the yield strength of the valve body material. The values ​​are larger when the deep-sea depth is greater, the ocean current velocity is higher, and the wall thickness of the key parts of the valve body is thinner, and vice versa.

[0095] When simulating and analyzing the biofouling characteristics of gate valves in a deep-sea environment, a nutrient concentration parameter is introduced into the ocean current impact field. The nutrient concentration is set according to the actual distribution pattern at different depths in the deep sea and serves as the basis for calculating the initial amount of biofouling. Then, a correlation model between the amount of biofouling and time is constructed.

[0096] In the initial stage, the amount of bio-attached organisms increases linearly over time. When the amount of bio-attached organisms reaches 80% of the preset saturation value, the growth rate decreases linearly until it approaches saturation.

[0097] Finally, the change in fluid resistance of the gate valve after bio-attachment is quantified: with the fluid resistance without bio-attachment as the benchmark, the fluid resistance coefficient increases by a preset proportion for each additional preset thickness of bio-attachment layer, and this change in resistance is fed back to the structural mechanical field to correct the fluid load on the valve body.

[0098] Based on the simulation results, a gate valve prototype with the corresponding parameter combination was prepared.

[0099] A deep-sea simulation test device was built to simulate deep-sea pressure, ocean current impact, seawater corrosion and biofouling environment. The gate valve prototype was placed in it to conduct performance testing under multi-physics field coupling environment, and data on pressure resistance, impact resistance, corrosion resistance and biofouling resistance were obtained simultaneously.

[0100] The deep-sea simulation test device, used to simulate deep-sea pressure, ocean current impact, seawater corrosion and biofouling environment, consists of a pressure control module, an ocean current simulation module, a seawater corrosion simulation module, and a biofouling simulation module.

[0101] The pressure control module employs a staged pressurization method, with the pressurization rate adjusted based on the elastic modulus, yield strength, and Poisson's ratio of the gate valve prototype material.

[0102] When the material's elastic modulus is lower or its yield strength is smaller, the pressurization rate is reduced; when the material's elastic modulus is higher and its yield strength is greater, the pressurization rate is increased. At the same time, a pressure holding unit is set, and the holding time is set according to the performance testing requirements.

[0103] The ocean current simulation module constructs a three-dimensional ocean current field through several sets of evenly distributed adjustable speed thrusters. The speed and direction of the thrusters are independently controlled to simulate the changes in ocean current velocity and direction in different deep-sea areas.

[0104] The seawater corrosion simulation module is equipped with a recyclable seawater medium circulation system. The ion concentration and temperature in the medium are adjusted in real time, and the medium parameters are monitored in real time through sensors to ensure that the chemical field parameters of seawater corrosion inside the device are consistent with those in the simulation model.

[0105] The bio-attachment simulation module is used to set up a bio-inoculation unit in the test device, which can be connected to a preset type of deep-sea attachment organisms. The temperature and nutrient concentration are simultaneously controlled to adapt to the environment for bio-attachment, simulating the attachment process of organisms on the surface of the gate valve prototype.

[0106] The operation for performance testing and acquisition of data on pressure resistance, impact resistance, corrosion resistance, and bioadhesion resistance under multiphysics coupling environment is as follows:

[0107] The surface pressure and internal chamber pressure of the gate valve prototype are collected in real time by a pressure sensor. The sampling frequency is set according to the pressure change rate. When the pressure change rate is less than the preset value, the sampling frequency is reduced to the preset base frequency. When the pressure change rate exceeds the preset value, the sampling frequency is increased by a preset ratio.

[0108] The vibration acceleration of the gate valve prototype under the impact of ocean currents is collected by an accelerometer, and the displacement of key parts of the valve body is collected by a displacement sensor. During the data acquisition process, abnormal values ​​caused by sensor noise are removed. The standard for judging abnormal values ​​is a preset multiple that exceeds the normal data range.

[0109] The corrosion current density on the surface of the gate valve prototype is collected by a corrosion sensor and then converted into corrosion rate. At the same time, the changes in ion concentration in the seawater medium are sampled and analyzed at a preset period.

[0110] Biofouling images of the surface of a gate valve prototype are periodically captured by a camera. The biofouling area and thickness are obtained based on image recognition. At the same time, the change in fluid resistance after biofouling is measured and used as an evaluation index of anti-biofouling performance.

[0111] In the bio-attachment image recognition stage, the bio-attachment area and attachment thickness are identified by a threshold segmentation algorithm and a thickness inversion algorithm based on stereo vision and shadow gradient fusion, respectively.

[0112] The performance data is fed back to the multiphysics coupling model for parameter iterative optimization, and the optimal parameter combination of the gate valve is finally determined.

[0113] When feeding performance data back to the multiphysics coupled model for parameter iterative optimization, the following applies:

[0114] The performance data obtained from the experiment is compared one by one with the simulation data output by the simulation platform, and the relative error between the two is calculated. If the relative error of a certain performance index exceeds a preset threshold, the physical field model parameters corresponding to that performance index are corrected.

[0115] For performance indicators with excessive relative error, locate their related parameters, adjust the parameter values ​​according to the error direction, and adjust the adjustment range by a preset proportion of the current value of the parameter.

[0116] When, after a preset number of iterations, the relative errors between the experimental and simulation data for all performance indicators are less than a preset threshold, and all performance indicators meet the design requirements for deep-sea gate valves, the iteration stops. If, after a preset number of iterations, there are still relative errors that do not meet the preset threshold, the coupling relationship of the multiphysics coupling model is readjusted, and the iteration continues.

[0117] Based on the performance indicators that did not meet the standards, the associated coupled field pairs were identified. For example, if the pressure resistance performance error exceeded the standard, the coupling relationship between the deep-sea pressure field and the structural mechanical field was analyzed in detail; if the corrosion resistance performance error exceeded the standard, the bidirectional coupling relationship between the seawater corrosion chemical field and the structural mechanical field was analyzed in detail.

[0118] For the coupled field pairs in the positioning, their parameter transfer coefficients are corrected:

[0119] ;

[0120] In the formula: These are the original transfer coefficients of the coupled field pairs A and B; This is relative error; For coefficient adjustment factors, ∈ (0.1, 0.5), The larger the value, the larger the value; the higher the physical interaction strength between the coupled field pairs, the smaller the value.

[0121] The above formula uses the original transfer coefficient of the coupled field, the relative error, and the coefficient adjustment factor as variables. The transfer coefficient is dynamically adjusted according to the magnitude of the relative error of the performance index. When there is a deviation between the experimental data and the simulation data, the parameter transfer relationship between the coupled fields is accurately corrected by this formula, ensuring that the coupled model can more accurately simulate the interaction between the physical fields and improve the iterative optimization efficiency and accuracy of the multi-physics coupled model.

[0122] Reassign priority weights to each field coupling:

[0123] Let the original coupling priority weight vector be... These correspond to the coupling priorities of the pressure field, flow field, corrosion field, and structural mechanics field, respectively. The weights are adjusted according to the error proportion, increasing the weight of fields with excessive errors, while still satisfying the requirements after adjustment. , This represents the adjusted i-th weight;

[0124] Dynamic response trigger condition adjustment:

[0125] For the coupled field pairs in the positioning, determine the associated dynamic response triggering threshold type, including the pressure change rate threshold for the pressure field, the flow velocity change rate threshold for the flow field, and the ion concentration change rate threshold for the corrosion field. Based on the error degree of the corresponding performance index of the field pair, correct the threshold:

[0126] The higher the error level, the greater the downward adjustment of the trigger threshold. The adjustment process ensures that the trigger threshold remains within the range that conforms to the physical changes in the actual deep-sea environment. After adjusting the coupling relationship, the multiphysics coupling simulation platform is run again, and the corrected simulation data is output and compared with historical experimental data. If the error of a single coupled field pair drops to within the preset threshold, the next round of global iteration begins. If the target is still not met, the process of positioning the associated coupled field pair, correcting the parameter transfer coefficient, allocating the priority weight of each field coupling, and adjusting the dynamic response trigger conditions is repeated until the coupling relationship meets the expected accuracy requirements.

[0127] In this embodiment, the above method can accurately simulate deep-sea environments such as pressure, ocean currents, corrosion, and biofouling, optimize key parameters such as the gate valve body and sealing, and effectively improve the gate valve's pressure resistance, impact resistance, corrosion resistance, and biofouling resistance through simulation screening and physical testing. The optimal parameters can be determined through data feedback iteration, reducing R&D trial and error costs, ensuring the stable operation of the gate valve in the complex deep-sea environment, and providing strong support for the reliability of deep-sea engineering equipment.

[0128] Regarding the method in the above embodiments, the following is an application example of the method:

[0129] A company needs to develop a gate valve suitable for a depth of 3000 meters in the ocean. The above method was used to conduct parameter optimization and performance testing. The specific process is as follows:

[0130] I. Establishment and Parameter Input of Multiphysics Coupled Model

[0131] First, a coupled model was established, incorporating the deep-sea pressure field, ocean current impact field, seawater corrosion chemical field, and structural mechanical field. The model input parameters were set as follows: pressure of 30 MPa corresponding to a depth of 3000 meters; ocean current velocity of 0.5-1.2 m / s in the target sea area; chloride ion concentration increasing with depth in the corrosive seawater medium, reaching 22000 mg / L at 3000 meters, and temperature of 4℃; the valve body material was selected as titanium alloy TC4, with an elastic modulus of 110 GPa and a yield strength of 860 MPa; the initial sealing structure dimensions included a sealing surface width of 5 mm, a valve stem diameter of 20 mm, and a valve core curvature radius of 15 mm.

[0132] II. Key Parameter Optimization Design

[0133] The parameters were optimized with the goal of minimizing the objective function. Weighting coefficients for the maximum equivalent stress, average corrosion rate, and fluid pressure difference were set to 0.4, 0.3, and 0.3, respectively, ultimately yielding a minimum objective function value of 85. The optimization process also satisfied the following constraints: the valve body material yield strength was no less than 860 MPa, the sealing surface contact pressure was no less than 2 MPa, and the fluid resistance coefficient was no higher than 0.08. Specifically, the valve core shape optimization was as follows: for a maximum ocean current velocity of 1.2 m / s, the radius of curvature of the valve core inlet and outlet arcs was set to 20 mm to reduce impact resistance; the sealing surface taper was set to 1:10, the contact pressure variation coefficient was 0.15 (lower than the preset threshold of 0.2); the flow channel cross-sectional area change rate was controlled at 12% (lower than the preset 15%), and the surface roughness Ra was 0.8 μm.

[0134] III. Multiphysics Coupled Simulation and Optimal Solution Selection

[0135] A coupled simulation platform was built, and the coupled calculation module enabled real-time data interaction between different fields. The initial simulation step size was set to 0.1 s, and when the rate of change of flow field parameters exceeded 5%, the step size was automatically reduced to 0.03 s. The performance index submodule output showed: the maximum equivalent stress of the gate valve was 620 MPa, the average corrosion rate was 0.02 mm / year, the fluid resistance coefficient was 0.07, and the biofouling reached 80% of the saturation value (saturation amount 200 g / m²) after 30 days. Based on the simulation results, three optimal parameter combinations were selected:

[0136] The valve body has a wall thickness of 18mm, a sealing surface width of 5mm, a valve stem diameter of 20mm, and a valve core curvature radius of 20mm.

[0137] The valve body has a wall thickness of 19mm, a sealing surface width of 6mm, a valve stem diameter of 21mm, and a valve core curvature radius of 18mm.

[0138] The valve body has a wall thickness of 17mm, a sealing surface width of 5mm, a valve stem diameter of 19mm, and a valve core curvature radius of 22mm.

[0139] IV. Prototype Preparation and Deep-Sea Environment Simulation Testing

[0140] A prototype gate valve was prepared based on three sets of parameters and tested in a deep-sea simulation test device.

[0141] The pressure control module uses a pressurization rate of 0.5 MPa / s (matching the performance of titanium alloy TC4), pressurizes to 30 MPa and holds the pressure for 24 hours. The pressure sensor measured a surface pressure of 30 MPa and an internal chamber pressure of 0.1 MPa (no leakage).

[0142] The ocean current simulation module simulates a three-dimensional ocean current of 0.5-1.2 m / s using 8 sets of thrusters. The vibration acceleration measured by the acceleration sensor is ≤0.8g, and the displacement is ≤0.2mm (outliers exceeding 1.5g are removed).

[0143] The seawater corrosion simulation module maintained a chloride ion concentration of 22000 mg / L and a temperature of 4℃, and the corrosion sensor measured a corrosion rate of 0.02 mm / year.

[0144] The bio-attachment module was inoculated with barnacle larvae (nutrient concentration 0.5 mg / L). After 30 days, image recognition showed that the attachment area was 35%, the thickness was 0.8 mm, and the fluid resistance coefficient increased to 0.09.

[0145] V. Data Feedback and Iterative Optimization

[0146] Comparison of experimental and simulation data: The experimental value of fluid resistance coefficient is 0.09, and the simulation value is 0.075, with a relative error of 20% (exceeding the preset threshold of 15%), so the model needs to be corrected.

[0147] Corrected flow field and structural mechanical field transmission coefficients: The original coefficient was 0.8. After combining a 20% relative error and an adjustment factor of 0.1, the corrected coefficient is 0.816.

[0148] Adjust the coupling priority weights: the original weights for pressure field, flow field, corrosion field, and structural field were 0.3:0.2:0.2:0.3. Since the flow field error accounts for 60%, the adjusted weights are 0.2:0.4:0.2:0.2.

[0149] The dynamic response threshold for the flow field has been adjusted downwards by 20% from 5% to 4%.

[0150] After resimulation, the simulated fluid resistance coefficient was 0.087, and the relative error with the experimental value of 0.09 was reduced to 3.3%. After three iterations, the errors of all performance indicators were less than 15%, and the first set of parameters (valve body wall thickness 18mm, sealing surface width 5mm, valve stem diameter 20mm, valve core curvature radius 20mm) was finally determined to be the optimal parameter combination for this 3000-meter deep-sea gate valve.

[0151] In summary, the methods described in the above embodiments, during execution, establish a multi-physics coupling model encompassing deep-sea pressure, ocean current impact, seawater corrosion, and structural mechanics. This model accurately maps the comprehensive effects of the complex deep-sea environment on the gate valve. By inputting key parameters and combining them with constraints using a multi-performance index weighted optimization function, the scientific design of key parameters for the valve body, sealing components, valve stem, and valve core is achieved, generating high-quality candidate solutions. Simulation analysis can be used to assess the gate valve's stress, corrosion, fluid resistance, and biofouling characteristics in advance, efficiently selecting the optimal parameter combination. Real performance data obtained through experiments simulating the deep-sea environment is then fed back to the model for iterative optimization, correcting parameters and coupling relationships to ensure that parameter design fits actual working conditions. The final determined optimal parameters enable the gate valve to possess excellent pressure resistance, impact resistance, corrosion resistance, and biofouling resistance, allowing it to stably adapt to complex deep-sea conditions, extending its service life, and reducing subsequent maintenance costs.

[0152] The above 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 will 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.

Claims

1. A method for parameter optimization and performance testing of deep-sea gate valves based on multiphysics coupling, characterized in that, include: Establish a multi-physics coupled model that includes deep-sea pressure field, ocean current impact field, seawater corrosion chemical field, and structural mechanical field; For the multiphysics coupling model, input deep-sea depth pressure, ocean current velocity, seawater corrosive medium, valve body material parameters, sealing structure size parameters, valve stem structure parameters, and valve core shape parameters, optimize the key parameters of the gate valve's valve body structure, sealing components, valve stem structure, and valve core shape, and determine the value combinations of each parameter to generate several sets of candidate parameter schemes; When optimizing the key parameters of the gate valve's body structure, sealing components, stem structure, and core shape, the optimization is accomplished using the following function: ； In the formula: This is a vector of key parameters, including valve body wall thickness, sealing surface width, valve stem diameter, and valve core curvature radius; These are the weighting coefficients for maximum equivalent stress, average corrosion rate, and fluid pressure difference. All are positive numbers, and their sum is 1; The maximum equivalent stress of the gate valve corresponding to the key parameter vector X; The average corrosion rate of the gate valve corresponding to the key parameter vector X; The key parameter vector X corresponds to the pressure difference between the inlet and outlet fluids of the gate valve; In the optimization process, with The goal is to minimize the pressure while simultaneously satisfying constraints on the valve body material yield strength, the sealing surface contact pressure, and the fluid resistance coefficient. A multiphysics coupling simulation platform for deep-sea gate valves was constructed. The candidate parameter schemes were imported into the platform, and the stress, corrosion, fluid resistance and biofouling characteristics of the gate valves in the deep-sea environment were simulated and analyzed. The three sets of parameter combinations with the best performance were then selected. Based on the simulation results, a gate valve prototype with the corresponding parameter combination was prepared. A deep-sea simulation test device was built to simulate deep-sea pressure, ocean current impact, seawater corrosion and biofouling environment. The gate valve prototype was placed in it to conduct performance testing under multi-physics field coupling environment, and data on pressure resistance, impact resistance, corrosion resistance and biofouling resistance were obtained simultaneously. The performance data is fed back to the multiphysics coupling model for parameter iterative optimization, and the optimal parameter combination of the gate valve is finally determined. In the modeling process of the seawater corrosion chemical field, the parameter settings and dynamic simulation of the seawater corrosion medium are as follows: The variation of chloride ion concentration in seawater with deep-sea depth is simulated: the chloride ion concentration increases by a preset ratio for each increase in depth; a seawater temperature gradient parameter is introduced: the temperature variation with depth is used as a correction term for corrosion rate calculation. The corrosion rate in the seawater corrosion chemical field is expressed as: ; In the formula; Here is the corrosion rate constant; This refers to the chloride ion concentration in seawater. This is the activation energy for the corrosion reaction; It is the ideal gas constant; The absolute temperature of seawater; This is the stress corrosion sensitivity coefficient; This represents the effective stress of the valve body.

2. The method for parameter optimization and performance testing of deep-sea gate valves based on multiphysics coupling according to claim 1, characterized in that, The multiphysics coupling model, when established, follows the following rules: Using the deep-sea pressure field as the initial action field, the deep-sea pressure is converted into a uniformly distributed load on the valve body surface, which serves as the input boundary condition for the structural mechanics field. Based on the velocity distribution of the ocean current impact field, the impact force and torque of the fluid on the valve body, valve stem, and valve core are calculated and superimposed onto the load system of the structural mechanics field. Establish a two-way coupling relationship between the seawater corrosion chemical field and the structural mechanical field: First, the stress distribution of the valve body obtained from structural mechanics field calculations is used as a corrosion acceleration factor input into the seawater corrosion chemical field; Secondly, the seawater corrosion chemical field acquires corrosion damage parameters in real time through corrosion sensors, including the corrosion depth on the valve body surface and the residual strength of the material in the corrosion area. The corrosion depth is used to proportionally correct the elastic modulus and yield strength of the valve body material in the structural mechanical field, while the residual strength of the material in the corrosion area is directly used as the core indicator for verifying the bearing capacity of the valve body in the structural mechanical field. If the residual strength of the material in any area is lower than the preset safety threshold, the corresponding structural parameters of that area will be re-optimized. Key parameters of the biofilm layer are defined, including the layer thickness and density. In the ocean current impact field, the fluid resistance coefficient is corrected using the layer thickness as a variable. For every increase in the layer thickness by a preset value, the fluid resistance coefficient increases by a preset proportion. In the structural mechanics field, the mass of the biofilm layer is calculated based on its thickness and density. This mass is then converted into an additional uniformly distributed load acting on the attachment area of ​​the valve body surface. Simultaneously, based on this mass and its distribution on the valve body surface, the valve body's moment of inertia and mass distribution are corrected.

3. The method for parameter optimization and performance testing of deep-sea gate valves based on multiphysics coupling according to claim 1, characterized in that, The optimized design of the valve core shape parameters includes: Streamlined profile design of valve core: With the goal of reducing ocean current impact resistance, the inlet and outlet ends of the valve core adopt a rounded transition. The radius of curvature of the rounded transition is determined according to the ocean current velocity range. The higher the velocity, the larger the radius of curvature. Valve core sealing surface parameter design: The taper and width of the sealing surface match the structural parameters of the sealing assembly, so that the pressure distribution is uniform when the sealing surface contacts the sealing assembly, and the coefficient of variation of the contact pressure is less than the preset threshold. Valve core internal flow channel design: The rate of change of the cross-sectional area of ​​the flow channel must be controlled within a preset range, and the surface roughness of the flow channel must be lower than the preset roughness.

4. The method for parameter optimization and performance testing of deep-sea gate valves based on multiphysics coupling according to claim 1, characterized in that, The deep-sea gate valve multiphysics coupling simulation platform consists of a coupling calculation module, a preset simulation step size control logic, and a performance index calculation submodule. The coupled calculation module supports real-time data interaction between the deep-sea pressure field and the structural mechanical field, dynamic parameter transfer between the ocean current impact field and the seawater corrosion chemical field, and coordinated correction of each field by the parameters of the biofilm layer. In the preset simulation step size control logic, a preset basic step size is used in the initial stage of simulation; when the rate of change of a parameter of a certain physical field is detected to exceed the preset threshold, the step size is automatically reduced to 1 / 5 to 1 / 3 of the preset basic step size. The performance index calculation submodule automatically outputs the stress distribution cloud map, corrosion rate contour map, fluid resistance coefficient curve, and bio-attachment amount change curve of the gate valve based on the simulation data.

5. The method for parameter optimization and performance testing of deep-sea gate valves based on multiphysics coupling according to claim 1, characterized in that, When simulating and analyzing the biofouling characteristics of the gate valve in a deep-sea environment, a nutrient concentration parameter is introduced into the ocean current impact field. The nutrient concentration is set according to the actual distribution pattern at different depths in the deep sea and serves as the basis for calculating the initial amount of biofouling. Then, a correlation model between the amount of biofouling and time is constructed. In the initial stage, the amount of biological attachment increases linearly over time. When the amount of attachment reaches 80% of the preset saturation value, the growth rate decreases linearly until it approaches saturation. Finally, the change in fluid resistance of the gate valve after bio-attachment is quantified: with the fluid resistance without bio-attachment as the benchmark, the fluid resistance coefficient increases by a preset proportion for each additional preset thickness of bio-attachment layer, and this resistance change is fed back to the structural mechanics field to correct the fluid load on the valve body.

6. The method for parameter optimization and performance testing of deep-sea gate valves based on multiphysics coupling according to claim 1, characterized in that, The deep-sea simulation test device for simulating deep-sea pressure, ocean current impact, seawater corrosion and biofouling environment consists of a pressure control module, an ocean current simulation module, a seawater corrosion simulation module, and a biofouling simulation module. The pressure control module employs a staged pressurization method, with the pressurization rate adjusted based on the elastic modulus, yield strength, and Poisson's ratio of the gate valve prototype material. When the material's elastic modulus is lower or its yield strength is smaller, the pressurization rate is reduced; when the material's elastic modulus is higher and its yield strength is greater, the pressurization rate is increased. At the same time, a pressure holding unit is set, and the holding time is set according to the performance testing requirements. The ocean current simulation module constructs a three-dimensional ocean current field through several sets of evenly distributed adjustable speed thrusters. The speed and direction of the thrusters are independently controlled to simulate the changes in ocean current velocity and direction in different deep-sea areas. The seawater corrosion simulation module is equipped with a recyclable seawater medium circulation system. The ion concentration and temperature in the medium are adjusted in real time, and the medium parameters are monitored in real time through sensors to ensure that the chemical field parameters of seawater corrosion inside the device are consistent with those in the simulation model. The bio-attachment simulation module is used to set up a bio-inoculation unit in the test device, which can be connected to a preset type of deep-sea attachment organism. The temperature and nutrient concentration are simultaneously controlled to adapt to the environment for bio-attachment, simulating the attachment process of organisms on the surface of the gate valve prototype.

7. The method for parameter optimization and performance testing of deep-sea gate valves based on multiphysics coupling according to claim 1, characterized in that, The operation for performance testing and acquisition of data on pressure resistance, impact resistance, corrosion resistance, and bioadhesion resistance under the multiphysics coupling environment is as follows: The surface pressure and internal chamber pressure of the gate valve prototype are collected in real time by a pressure sensor. The sampling frequency is set according to the pressure change rate. When the pressure change rate is less than the preset value, the sampling frequency is reduced to the preset base frequency. When the pressure change rate exceeds the preset value, the sampling frequency is increased by a preset ratio. The vibration acceleration of the gate valve prototype under the impact of ocean currents is collected by an accelerometer, and the displacement of key parts of the valve body is collected by a displacement sensor. During the data acquisition process, abnormal values ​​caused by sensor noise are removed. The standard for judging abnormal values ​​is a preset multiple that exceeds the normal data range. The corrosion current density on the surface of the gate valve prototype is collected by a corrosion sensor and then converted into corrosion rate. At the same time, the changes in ion concentration in the seawater medium are sampled and analyzed at a preset period. Biofouling images of the surface of a gate valve prototype are periodically captured by a camera. The biofouling area and thickness are obtained based on image recognition. At the same time, the change in fluid resistance after biofouling is measured and used as an evaluation index for anti-biofouling performance.

8. The method for parameter optimization and performance testing of deep-sea gate valves based on multiphysics coupling according to claim 1, characterized in that, When feeding performance data back to the multiphysics coupled model for parameter iterative optimization, the following applies: The performance data obtained from the experiment is compared one by one with the simulation data output by the simulation platform, and the relative error between the two is calculated. If the relative error of a certain performance index exceeds a preset threshold, the physical field model parameters corresponding to that performance index are corrected. For performance indicators with excessive relative error, locate their related parameters, adjust the parameter values ​​according to the error direction, and adjust the adjustment range by a preset proportion of the current value of the parameter. When, after a preset number of iterations, the relative errors between the experimental and simulation data for all performance indicators are less than a preset threshold, and all performance indicators meet the design requirements for deep-sea gate valves, the iteration stops. If, after a preset number of iterations, there are still relative errors that do not meet the preset threshold, the coupling relationship of the multiphysics coupling model is readjusted, and the iteration continues. Based on the performance indicators that did not meet the standards, locate the associated coupled field pairs; For the coupled field pairs in the positioning, their parameter transfer coefficients are corrected: ； In the formula: These are the original transfer coefficients of the coupled field pairs A and B; This is relative error; This is the coefficient adjustment factor; Reassign priority weights to each field coupling: Let the original coupling priority weight vector be... These correspond to the coupling priorities of the pressure field, flow field, corrosion field, and structural mechanics field, respectively. The weights are adjusted according to the error proportion, so that the weights of fields with excessive errors are increased, while still meeting the requirements after adjustment. , This represents the adjusted i-th weight; Dynamic response trigger condition adjustment: For a coupled field pair for positioning, determine the associated dynamic response trigger threshold type, and adjust the threshold based on the error level of the corresponding performance index of the field pair: The higher the error level, the greater the downward adjustment of the trigger threshold. The adjustment process ensures that the trigger threshold remains within the range that conforms to the physical changes in the actual deep-sea environment. After adjusting the coupling relationship, the multiphysics coupling simulation platform is run again, and the corrected simulation data is output and compared with historical experimental data. If the error of a single coupled field pair drops to within the preset threshold, the next round of global iteration begins. If the target is still not met, the process of positioning the associated coupled field pair, correcting the parameter transfer coefficient, allocating the priority weight of each field coupling, and adjusting the dynamic response trigger conditions is repeated until the coupling relationship meets the expected accuracy requirements.

Images