Simulation method and system for insulation injection molding dynamic process of submarine cable extrusion molding joint

Abstract

The invention discloses a submarine cable extrusion molding joint insulation injection molding dynamic process simulation method and system, and relates to the field of submarine cable simulation, and the method comprises the steps: building a geometric model of a submarine cable extrusion molding joint, and setting material parameters; establishing a recovery insulation injection molding dynamic simulation model of the submarine cable extrusion molding joint; setting an initial value and a boundary condition of the dynamic simulation model; performing grid division on the geometric model to obtain a finite element grid; and based on the recovery insulation injection molding dynamic simulation model, the initial value, the boundary condition and the finite element mesh, simulating the recovery insulation injection molding process of the submarine cable extrusion molding joint, and iteratively calculating the velocity field, the force field, the temperature field and the volume fraction distribution in the recovery insulation injection molding process. According to the method, the dynamic process of insulation injection molding of the extrusion molding joint can be determined, the formation process of recovery insulation is researched, and reference and guidance are provided for parameter design of an insulation preparation process of the extrusion molding joint.

Description

Technical Field

[0001] The present application relates to the field of submarine cable simulation, and in particular to a method and system for simulating the dynamic process of submarine cable extrusion molding joint insulation injection molding. Background Art

[0002] High-voltage direct current submarine cable is an important equipment of the power transmission system. Its reliable operation ensures the safety and stability of the offshore wind power system. The insulation of the extrusion molded joint is prepared by injection molding and extruding the same insulating material as the submarine cable body. The manufacturing method is as follows: the newly melted insulation is injected into the surface of the reaction force cone through a mold, and is heated, pressurized and degassed at the same time. The insulation of the extrusion molded joint mainly includes body insulation and recovery insulation. Although the insulation of the extrusion molded joint is composed of the same material, such as cross-linked polyethylene, polypropylene, etc., the welding between the body insulation and the recovery insulation is directly affected by the preparation process, and an interface area is inevitably formed between the two. By cutting the insulation layer of the actual submarine cable extrusion molded joint, it is found that there is indeed an interface area with tiny cracks near the interface. Because these cracks exist as defects, the insulation performance of the interface area is reduced. Compared with the cable insulation, the initial voltage of the electric tree in the interface area is reduced by 30%. It can be seen that the existence of the interface area seriously affects the quality of the extrusion molded joint. From the perspective of interface formation, the influence of the recovery insulation injection molding process cannot be ignored. Selecting appropriate injection molding process parameters is of great significance to avoid the formation of insulation interface. Summary of the invention

[0003] The purpose of this application is to provide a method and system for simulating the dynamic process of insulation injection molding of submarine cable extrusion molded joints, which can simulate the dynamic process of insulation injection molding of extrusion molded joints and provide reference and guidance for the design of process parameters for extrusion molded joint insulation preparation.

[0004] To achieve the above objectives, this application provides the following solutions:

[0005] In a first aspect, the present application provides a method for simulating the dynamics process of insulation injection molding of a submarine cable extrusion molding joint, comprising:

[0006] Establish the geometric model of submarine cable extrusion molding joint and set the material parameters;

[0007] Based on the geometric model and material parameters, a dynamic simulation model of the recovery insulation injection molding of the submarine cable extrusion molding joint is established;

[0008] Setting the initial values ​​and boundary conditions of the recovery insulation injection molding dynamics simulation model;

[0009] Meshing the geometric model to obtain a finite element mesh;

[0010] Based on the recovery insulation injection molding dynamics simulation model, the initial value, the boundary conditions and the finite element mesh, the recovery insulation injection molding process of the submarine cable extrusion molding joint is simulated, and the velocity field, force field, temperature field and volume fraction distribution in the recovery insulation injection molding process are iteratively calculated.

[0011] In a second aspect, the present application provides a submarine cable extrusion molding joint insulation injection molding dynamics process simulation system, comprising:

[0012] A geometry model building module, which is used to build the geometry model of submarine cable extrusion molding joints and set material parameters;

[0013] A dynamic model building module, used to establish a dynamic simulation model of the recovery insulation injection molding of the submarine cable extrusion molding joint based on the geometric model and material parameters;

[0014] A condition setting module, used to set the initial value and boundary conditions of the recovery insulation injection molding dynamics simulation model;

[0015] A meshing module, used for meshing the geometric model to obtain a finite element mesh;

[0016] A simulation module is used to simulate the recovery insulation injection molding process of the submarine cable extrusion molded joint based on the recovery insulation injection molding dynamics simulation model, the initial value, the boundary condition and the finite element grid, and iteratively calculate the velocity field, force field, temperature field and volume fraction distribution in the recovery insulation injection molding process.

[0017] According to the specific embodiments provided in this application, this application has the following technical effects:

[0018] The present application provides a method and system for simulating the dynamic process of insulation injection molding of a submarine cable extrusion molded joint. By constructing a geometric model of the submarine cable extrusion molded joint and a dynamic simulation model of insulation recovery injection molding, the insulation recovery injection molding process of the submarine cable extrusion molded joint is simulated, and the velocity field, force field, temperature field and volume fraction distribution in the insulation recovery injection molding process are iteratively calculated. The dynamic process of insulation injection molding of the extrusion molded joint can be determined, the formation process of insulation recovery can be studied, and reference and guidance can be provided for the design of process parameters for insulation preparation of the extrusion molded joint. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0020] Figure 1 This is an application environment diagram of a method for simulating the dynamics process of insulation injection molding of a submarine cable extrusion molding joint in one embodiment of the present application;

[0021] Figure 2 A schematic flow chart of a method for simulating the dynamics process of insulation injection molding of a submarine cable extrusion molded joint provided in one embodiment of the present application;

[0022] Figure 3 It is a schematic diagram of the structure of the submarine cable extrusion molding connector and injection molding device;

[0023] Figure 4 A schematic diagram of a simulation process in an embodiment of the present application;

[0024] Figure 5 The structure and dimension drawings of the extrusion molded connector and injection molding device for ±500kV high voltage DC submarine cable;

[0025] Figure 6 It is the viscosity characteristic curve of cross-linked polyethylene insulation material;

[0026] Figure 7 This is a calculation result diagram when the simulation time is 180 seconds in the example provided in this application;

[0027] Figure 8 This is a calculation result diagram when the simulation time is 380 seconds in the example provided in this application;

[0028] Fig. 9 This is a calculation result diagram when the simulation time is 680 seconds in the example provided in this application;

[0029] Fig.10 A schematic diagram of functional modules of a submarine cable extrusion molding joint insulation injection molding dynamics process simulation system provided in one embodiment of the present application;

[0030] Fig.11 A schematic diagram of the structure of a computer device provided in one embodiment of the present application.

[0031] Reference numerals: 301 - inner semiconductive layer and conductor, 302 - reaction force cone of body insulation, 303 - restoration insulation injection cavity, 304 - injection mold, 305 - injection port, 306 - heating mold, 501 - air outlet. DETAILED DESCRIPTION

[0032] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0033] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, the present application is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0034] The simulation method for the dynamic process of submarine cable extrusion molding joint insulation injection molding provided in the embodiment of the present application can be applied to Figure 1 In the application environment shown. Among them, the terminal 102 communicates with the server 104 through the network. The data storage system can store the data that the server 104 needs to process. The data storage system can be set up separately, integrated on the server 104, or placed on the cloud or other servers. The terminal 102 can send the relevant parameters of the submarine cable extrusion molding joint to the server 104, and the server 104 establishes a geometric model dynamic simulation model according to the relevant parameters, and simulates the recovery insulation injection molding process of the submarine cable extrusion molding joint. The server 104 can feedback the simulation results to the terminal 102. In addition, in some embodiments, the simulation method of the dynamic process of insulation injection molding of the submarine cable extrusion molding joint can also be implemented by the server 104 or the terminal 102 alone.

[0035] The terminal 102 may be, but is not limited to, various desktop computers, laptop computers, smart phones, tablet computers, IoT devices, and portable wearable devices. The IoT devices may be smart speakers, smart TVs, smart air conditioners, smart vehicle-mounted devices, etc. The portable wearable devices may be smart watches, smart bracelets, head-mounted devices, etc. The server 104 may be implemented as an independent server or a server cluster consisting of multiple servers, or may be a cloud server.

[0036] In an exemplary embodiment, Figure 2 As shown, a method for simulating the dynamic process of submarine cable extrusion molding joint insulation injection molding is provided. The method is executed by a computer device, specifically, it can be executed by a computer device such as a terminal or a server alone, or it can be executed by a terminal and a server together. In the embodiment of the present application, the method is applied to Figure 1 The server 104 in the example is used for explanation, and the steps include the following steps 201 to 205.

[0037] Step 201, establishing a geometric model of a submarine cable extrusion molded joint and setting material parameters.

[0038] In an exemplary embodiment, the parameter data of the submarine cable extrusion molding joint is first obtained, and a geometric model is established based on the parameter data, which includes geometric parameters and material parameters.

[0039] The geometric parameters include the geometric structure of the submarine cable molded joint, the size of the submarine cable molded joint, the geometric structure of the injection mold and the size of the injection mold.

[0040] Among them, Figure 3 As shown, the geometric structure of the submarine cable molded joint includes an inner semi-conductive layer and a conductor 301 and a reaction force cone 302 of the body insulation. The geometric structure of the injection mold 304 includes an injection port 305 and a recovery insulation injection cavity 303. The recovery insulation is injected into the recovery insulation injection cavity 303 from the injection port 305. Before the recovery insulation is injected, the interior of the recovery insulation injection cavity 303 is air. A heating mold 306 is provided outside the injection mold 304.

[0041] The material parameters include the thermal conductivity of the injection mold 304, the constant pressure heat capacity of the injection mold 304, the density of the injection mold 304, the thermal conductivity of the inner semiconductive layer and the conductor 301, the constant pressure heat capacity of the inner semiconductive layer and the conductor 301, the density of the inner semiconductive layer and the conductor 301, the thermal conductivity of the reaction force cone 302 of the body insulation, the constant pressure heat capacity of the reaction force cone 302 of the body insulation, the density of the reaction force cone 302 of the body insulation, the viscosity of the reaction force cone 302 of the body insulation, the thermal conductivity of air, the constant pressure heat capacity of air, the density of air, and the viscosity of air. Among them, the materials of the body insulation and the recovery insulation are the same.

[0042] The present application establishes a full-size geometric model of a submarine cable extrusion molded connector, including 1:1 proportional geometric modeling of the submarine cable molded connector and its injection mold 304. The geometric model is constructed by selecting Comsol finite element software and setting material parameters.

[0043] Step 202, based on the geometric model and material parameters, a dynamic simulation model of the recovery insulation injection molding of the submarine cable extrusion molding joint is established. The material parameters include the constant pressure heat capacity of the fluid, the density of the fluid, the thermal conductivity of the fluid, the viscosity of the fluid, the constant pressure heat capacity of the solid, the density of the solid and the thermal conductivity of the solid. The fluid includes the recovery insulation melt and air. The solid includes the reaction force cone of the body insulation and the injection mold.

[0044] This application establishes a full-scale submarine cable extrusion molding joint recovery insulation injection molding dynamics simulation model. The recovery insulation injection molding dynamics simulation model includes an injection molding dynamics model, an injection molding solid-fluid heat transfer model, a recovery insulation melt viscosity model, and an injection molding phase field model.

[0045] The following is a detailed introduction to each model.

[0046] (a) Injection molding dynamics model.

[0047] During the injection molding process, two fluids, insulating melt and air, are considered to be restored inside the injection mold. The injection molding dynamics model describes the dynamic behavior of the fluid based on the mass conservation equation shown in formula (1), the momentum conservation equation shown in formula (2), and the energy conservation equation shown in formula (3).

[0048]

[0049] Where ρ is the density of the fluid in g / cm 3 , t is time, u is the velocity of the fluid in m / s, p is the pressure in Pa, I is the unit tensor, τ is the viscous stress tensor in N / m 2 , g is the acceleration due to gravity, unit is m / s 2 , C ρ is the constant pressure heat capacity of the fluid, in J / (kg·K), T is the temperature, K, k is the thermal conductivity of the fluid, in W / (m·K), and Q is the heat source inside the fluid, in W / m 3 , ▽ is the Hamiltonian operator.

[0050] (ii) Injection molding solid-fluid heat transfer model.

[0051] The injection molding solid-fluid heat transfer model describes the temperature distribution of the medium inside the injection mold during the injection molding process based on the energy conservation equation. The medium inside the injection mold includes fluid and solid.

[0052] During the injection molding process, the temperature distribution of the recovered insulating melt and air inside the injection mold follows formula (3) for fluid heat transfer, and the temperature of other solids follows formula (4) for solid heat transfer.

[0053]

[0054] Among them, ρ g is the density of the solid in g / cm 3 , C ρg is the constant pressure heat capacity of the solid, in J / (kg·K), k g is the thermal conductivity of the solid, in W / (m·K), Q c is the heat source inside the solid, in W / m 3 .

[0055] (iii) Restore the insulating melt viscosity model.

[0056] The restored insulating melt viscosity model is used to fit the transformation characteristics of the restored insulating melt viscosity with temperature and shear rate, and determine the restored insulating melt stress-strain constitutive relationship.

[0057] Specifically, the viscosity parameters of the insulating sample were tested using a rotational rheometer to obtain the viscosity variation law at different shear rates and temperatures. Then, the restored insulating melt viscosity model shown in formula (5) and the restored insulating melt stress-strain constitutive relationship shown in formula (6) were established.

[0058]

[0059] τ=η(v+(v) T ) (6)

[0060] Where η is the viscosity of the fluid, η ∞ is the infinite shear viscosity, η0 is the zero shear viscosity in Pa·s, β is the relaxation time in s, v is the shear rate, n is the power law exponent, α is the temperature coefficient, and T0 is the initial temperature.

[0061] (iv) Injection molding phase field model.

[0062] The injection molding phase field model distinguishes the motion process of the recovery insulating melt and air based on the Cahn-Hilliard equation.

[0063] For the problem of restoring the two-phase flow of insulating melt and air, the Cahn-Hilliard equation shown in formula (7) is used to distinguish the movement of the two fluids during the simulation, especially the interface position.

[0064]

[0065] in, is the phase field variable, Indicates the restoration of the insulating fuse. represents air, t is time, γ is mobility, the unit is m3·s / kg, γ=ξ 2 χ,ξ are the thickness control parameters for restoring the interface between the insulating melt and the air. The unit is m, which is determined according to the size of the finite element grid. In this example, one fifth of the minimum grid unit of the fluid is taken. χ is the migration adjustment parameter. The unit is m·s / kg. It is an empirical parameter. The convergence of the calculation can be improved by adjusting the size of χ. In this example, 1m / s is taken. ψ is the auxiliary phase field variable. λ is the mixing energy density, in N, which is related to the surface tension and interface thickness. σ s is the surface tension coefficient, the unit is N / m, and in this example it is taken as 85mN / m.

[0066] Furthermore, in the process of restoring insulation injection molding, the dynamic behavior of the interface between the incompatible fluids is calculated. The injection molding dynamics model is coupled with the injection molding phase field model. The specific coupling process is:

[0067] Formula (1) to (3) are used to calculate the fluid velocity field, and formula (7) is used to control the phase field variables. Changes in the velocity field will change the interface position and the distribution of the two-phase components. The volume fraction of each phase can be expressed by the phase field variables, such as formula (8) to (10). At the interface between the two phases, in order to achieve a smooth transition between the two phases, the physical parameters are set to a smooth transition, such as formula (11) to (14). At the same time, in the two-phase flow, considering the effect of surface tension on fluid motion, the volume force caused by the surface tension of the two-phase fluid is calculated by formula (15). After coupling, formula (16) is used to replace formula (2) in the injection molding dynamics model.

[0068]

[0069] V f1 +V f2 =1 (10)

[0070] ρ s =ρ1V f1 +ρ2V f2 (11)

[0071] η s =η1V f1 +η2V f2 (12)

[0072] C ρs =C ρ1 V f1 +C ρ2 V f2 (13)

[0073] k s =k1V f1 +k2V f2 (14)

[0074]

[0075] Among them, V f1 is the volume fraction of the restored insulating melt, in %, V f2 is the volume fraction of air, in %, ρ s is the density of the fluid at the interface, in g / cm 3 , ρ1 is the density of the restored insulating melt, in g / cm 3 , ρ2 is the density of air, in g / cm 3 , η sis the viscosity of the fluid at the interface, in Pa·s, η1 is the viscosity of the restored insulating melt, in Pa·s, η2 is the viscosity of the air, in Pa·s, C ρs is the constant pressure heat capacity of the fluid at the interface, in J / (kg·K), C ρ1 To restore the constant pressure heat capacity of the insulating melt, the unit is J / (kg·K), C ρ2 is the constant pressure heat capacity of air, in J / (kg·K), k s is the thermal conductivity of the fluid at the interface, in W / (m·K), k1 is the thermal conductivity of the restored insulating melt, in W / (m·K), k2 is the thermal conductivity of air, in W / (m·K), F s is the volume force caused by the surface tension of the two-phase fluid, in N / m 3 .

[0076] Step 203, setting the initial values ​​and boundary conditions of the recovery insulation injection molding dynamics simulation model.

[0077] The initial values ​​include the solid temperature, fluid velocity, force, temperature and volume fraction distribution at the initial moment. The force includes the pressure, gravity, viscous stress and volume force caused by the surface tension of the two-phase fluid.

[0078] The boundary conditions include temperature boundary conditions and fluid boundary conditions.

[0079] Temperature boundary conditions: injection mold surface temperature; conductor surface temperature or external environment temperature.

[0080] Fluid boundary conditions: distribution of fluid inlet position and fluid outlet position; one or more of the air pressure, fluid velocity, flow rate, and fluid velocity size at the fluid inlet; one or more of the air pressure, fluid velocity, flow rate, and fluid velocity size at the fluid outlet.

[0081] Step 204, meshing the geometric model to obtain a finite element mesh.

[0082] In this example, Comsol finite element software is used for meshing. The mesh shape is a free tetrahedral mesh. The fluid and solid are divided separately to optimize the simulation results. The minimum unit size of the fluid mesh is 0.02mm; the minimum unit size of the solid mesh is 0.1mm; the meshing level of the fluid and solid boundary is set to ultrafine, and the resolution of the narrow area is set to 0.6; the calculation is performed by the backward difference formula method, the initial time step is set to 0.0001s, and the solver uses the step size to select the free level to ensure the validity of the simulation data. The setting of the simulation time refers to the injection time in the actual production process.

[0083] Step 205, based on the recovery insulation injection molding dynamics simulation model, the initial value, the boundary condition and the finite element mesh, the recovery insulation injection molding process of the submarine cable extrusion molded joint is simulated, and the velocity field, force field, temperature field and volume fraction distribution in the recovery insulation injection molding process are iteratively calculated.

[0084] The entire simulation process is modeled and differentially solved using Comsol finite element software. The velocity field, force field, and temperature field are solved by formula (1), formula (16), formula (3), formula (4), and formula (6). The force field includes the pressure, viscous stress, gravity, and volume force caused by the surface tension of the two-phase fluid. The pressure p is calculated using formula (16), the viscous stress tensor τ is calculated using formula (6), and the volume force F caused by the surface tension of the two-phase fluid is calculated using formula (15). s The volume fraction is calculated using formula (8) to formula (10).

[0085] In an exemplary embodiment, step 205 includes the following steps 301 to 305 .

[0086] Step 301 , simulating the insulation recovery injection molding process of the submarine cable extrusion molded joint based on the initial value, the boundary condition and the finite element mesh.

[0087] Step 302, for any moment in the recovery insulation injection molding process, calculate the velocity, force, temperature and material parameters of the fluid at the current moment.

[0088] Step 303, according to the velocity, force, temperature and material parameters of the fluid at the current moment, the injection molding dynamics model, the injection molding solid-fluid heat transfer model and the restored insulating melt stress-strain constitutive relationship are used to calculate the velocity, force and temperature of the fluid at the next moment to obtain the velocity field, force field and temperature field. Step 304, according to the volume fraction distribution of the fluid at the current moment and the velocity of the fluid at the next moment, the injection molding phase field model is used to calculate the position distribution of the fluid and determine the volume fraction distribution of the fluid at the next moment.

[0089] Step 305, calculating the density, viscosity, constant-pressure heat capacity and thermal conductivity of the fluid at the interface according to the material parameters and volume fraction distribution of the fluid at the next moment.

[0090] In order to better understand the technical solution of this application, Figure 4 Detailed description of the simulation process:

[0091] 1) Mesh the geometric model of the submarine cable extrusion molded joint.

[0092] 2) Preset simulation duration.

[0093] 3) Obtain the velocity field, force field, temperature field, and volume fraction of the restored insulating melt and air at the current moment.

[0094] 4) Calculate and restore the material parameters such as viscosity, thermal conductivity, etc. of the insulating melt and air at the current moment.

[0095] 5) Obtain temperature boundary conditions and fluid boundary conditions.

[0096] 6) The injection molding dynamics model, injection molding phase field model and injection molding fluid heat transfer model are used to calculate the velocity field, force field, volume fraction and temperature field of the fluid at the next moment:

[0097] Substitute the current speed, force, temperature and other parameters into formula (1), formula (3), formula (4), formula (6) and formula (16) to calculate the speed, force and temperature of the insulating melt and air at the next moment.

[0098] Combined with the current volume fraction distribution, the velocity at the next moment is substituted into formula (7) to calculate the position distribution of the restored insulating melt and air, and the volume fractions of the two fluids are calculated using formulas (8) to (10).

[0099] 7) Based on the calculated velocity, force, temperature and volume fraction of the two fluids, the density, viscosity and other parameters of the fluid at the interface are calculated using formulas (11) to (14), and then the velocity field, force field, temperature field and fluid volume fraction distribution results at the next moment are obtained.

[0100] 8) Update mold temperature using the injection molding solid heat transfer model.

[0101] 9) Determine whether the preset simulation duration is reached at the next moment:

[0102] If so, the velocity field, force field, temperature field, and volume fraction of the insulating melt and air are restored and output.

[0103] If not, according to the velocity field, force field, temperature field, and volume fraction distribution obtained by solving, based on the submarine cable extrusion molding joint insulation injection molding dynamics simulation model and boundary conditions, the viscosity, thermal conductivity and other material parameters of the insulation melt and air are updated and restored, and the above steps 6) to 9) are repeated using the finite element method.

[0104] This application also provides a specific example: taking a ±500kV high voltage DC submarine cable extrusion molded connector as an example, the insulation material type is cross-linked polyethylene. The specific extrusion molded connector structure and size are as follows: Figure 5 As shown, Figure 5 In the figure, 501 is the air outlet; the material parameters of the high voltage DC submarine cable extrusion molded connector are shown in Table 1.

[0105] Table 1 Material parameters of high voltage DC submarine cable extrusion molded connector

[0106]

[0107] The viscosity parameters of the insulating sample were tested using a rotational rheometer. Figure 6 As shown in Table 2, the viscosity variation law at different shear rates and temperatures is obtained, and then the characteristic equation of the viscosity of the insulating material melt is constructed and the stress-strain constitutive relationship of the insulating melt is restored. The viscosity fitting parameters are shown in Table 2.

[0108] Table 2 Viscosity parameters of cross-linked polyethylene insulation material

[0109] parameter Numeric <![CDATA[Zero shear viscosity η0]]> 49976 <![CDATA[Infinite shear viscosity η ∞ > 0 Power law index n 0.47 Relaxation time β 9.31 Temperature coefficient α 2612.9

[0110] The initial pressure and initial velocity of the fluid inside the injection mold 304 are set to 0; at the initial moment, no recovery insulation 303 is injected into the injection mold 304, and all is air; the initial temperature inside the injection mold 304 is 120°C; the initial temperature of the recovery insulation melt is 120°C.

[0111] The outer surface temperature of the injection mold 304 is set to 120°C; in order to control the overall injection time within 20 minutes to 30 minutes, the normal inflow velocity of the insulating melt at the injection port 305 is set to 0.03258 mm / s; the outlet pressure of the injection mold 304 is set to 0 Pa; the inlet and outlet positions of the fluid are as follows Figure 5 As shown in the figure, it is assumed that there is no slip between the insulating melt and the flow channel wall. The calculation results of this example are as follows Figures 7 to 9 As shown, it can be seen that the present application can accurately obtain the formation process of the recovery insulation 303.

[0112] Based on the same inventive concept, the embodiment of the present application also provides a simulation system for implementing the above-mentioned simulation method. The implementation scheme for solving the problem provided by the system is similar to the implementation scheme recorded in the above-mentioned method, so the specific limitations in one or more simulation system embodiments provided below can refer to the limitations on the simulation method above, and will not be repeated here.

[0113] In an exemplary embodiment, Fig.10 As shown, a submarine cable extrusion molding joint insulation injection molding dynamics process simulation system is provided, including: a geometric model construction module 601, a dynamic model construction module 602, a condition setting module 603, a meshing module 604 and a simulation module 605.

[0114] The geometric model building module 601 is used to build the geometric model of the submarine cable extrusion molding joint and set the material parameters.

[0115] The dynamic model building module 602 is used to establish a dynamic simulation model of the insulation recovery injection molding of the submarine cable extrusion molding joint based on the geometric model and material parameters.

[0116] The condition setting module 603 is used to set the initial value and boundary conditions of the recovery insulation injection molding dynamics simulation model.

[0117] The meshing module 604 is used to mesh the geometric model to obtain a finite element mesh.

[0118] The simulation module 605 is used to simulate the recovery insulation injection molding process of the submarine cable extrusion molding joint based on the recovery insulation injection molding dynamics simulation model, the initial value, the boundary conditions and the finite element mesh, and iteratively calculate the velocity field, force field, temperature field and volume fraction distribution in the recovery insulation injection molding process.

[0119] In an exemplary embodiment, a computer device is provided. The computer device may be a server or a terminal. The internal structure diagram thereof may be as follows: Fig.11 As shown. The computer device includes a processor, a memory, an input / output interface (Input / Output, I / O) and a communication interface. The processor, the memory and the input / output interface are connected through a system bus, and the communication interface is connected to the system bus through the input / output interface. The processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The database of the computer device is used to store the structure and material data of the full-size submarine cable extrusion molding structure. The input / output interface of the computer device is used to exchange information between the processor and an external device. The communication interface of the computer device is used to communicate with an external terminal through a network connection. When the computer program is executed by the processor, a method for simulating the dynamic process of submarine cable extrusion molding joint insulation injection molding is implemented.

[0120] Those skilled in the art will understand that Fig.11 The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine certain components, or have a different arrangement of components.

[0121] In an exemplary embodiment, a computer-readable storage medium is provided, storing a computer program, and when the computer program is executed by a processor, the steps in the above method embodiments are implemented.

[0122] In an exemplary embodiment, a computer program product is provided, including a computer program, and when the computer program is executed by a processor, the steps in the above method embodiments are implemented.

[0123] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, stored data, displayed data, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of relevant data must comply with relevant regulations.

[0124] In this application, all actions to obtain signals, information or data are carried out in compliance with the relevant data protection laws and policies of the country where they are located and with the authorization given by the owner of the corresponding device.

[0125] Those of ordinary skill in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to the memory, database or other medium used in the embodiments provided in the present application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM may be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM).

[0126] The database involved in each embodiment provided in this application may include at least one of a relational database and a non-relational database. The non-relational database may include a distributed database based on blockchain, etc., but is not limited thereto. The processor involved in each embodiment provided in this application may be a general-purpose processor, a central processing unit, a graphics processor, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, etc., but is not limited thereto.

[0127] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0128] This article uses specific examples to illustrate the principles and implementation methods of this application. The description of the above embodiments is only used to help understand the method and core ideas of this application. At the same time, for those skilled in the art, according to the ideas of this application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting this application.

Claims

1. A method for simulating the dynamic process of submarine cable extrusion molding joint insulation injection molding, characterized in that: The submarine cable extrusion molding joint insulation injection molding dynamics process simulation method comprises: Establish the geometric model of submarine cable extrusion molding joint and set the material parameters; Based on the geometric model and material parameters, a dynamic simulation model of the recovery insulation injection molding of the submarine cable extrusion molding joint is established; Setting the initial values ​​and boundary conditions of the recovery insulation injection molding dynamics simulation model; Meshing the geometric model to obtain a finite element mesh; Based on the recovery insulation injection molding dynamics simulation model, the initial value, the boundary conditions and the finite element mesh, the recovery insulation injection molding process of the submarine cable extrusion molding joint is simulated, and the velocity field, force field, temperature field and volume fraction distribution in the recovery insulation injection molding process are iteratively calculated.

2. The method for simulating the dynamic process of submarine cable extrusion molding joint insulation injection molding according to claim 1 is characterized in that: The material parameters include the constant pressure heat capacity of the fluid, the density of the fluid, the thermal conductivity of the fluid, the viscosity of the fluid, the constant pressure heat capacity of the solid, the density of the solid and the thermal conductivity of the solid; the recovery insulation injection molding dynamics simulation model includes an injection molding dynamics model, an injection molding solid-fluid heat transfer model, a recovery insulation melt viscosity model and an injection molding phase field model; The injection molding dynamics model describes the dynamic behavior of the fluid based on the mass conservation equation, momentum conservation equation and energy conservation equation; the fluid includes a restored insulating melt and air; The injection molding solid-fluid heat transfer model describes the temperature distribution of the medium inside the injection mold during the injection molding process based on the energy conservation equation; the medium inside the injection mold includes fluid and solid; the solid includes the reaction force cone of the body insulation and the injection mold; The restored insulating melt viscosity model is used to fit the transformation characteristics of the restored insulating melt viscosity with temperature and shear rate, and determine the restored insulating melt stress-strain constitutive relationship; The injection molding phase field model distinguishes the motion process of the recovery insulating melt and air based on the Cahn-Hilliard equation.

3. The method for simulating the dynamics process of insulation injection molding of submarine cable extrusion molding joints according to claim 2 is characterized in that: The injection molding kinetics model is: Where ρ is the density of the fluid, t is the time, u is the velocity of the fluid, p is the pressure, I is the unit tensor, τ is the viscous stress tensor, g is the gravitational acceleration, and F s is the volume force caused by the surface tension of the two-phase fluid, is the phase field variable, Indicates the restoration of the insulating fuse. represents air, ψ is an auxiliary phase field variable, λ is the mixing energy density, σ s is the surface tension coefficient, ξ is the thickness control parameter for restoring the interface between the insulating melt and the air, which is determined according to the size of the finite element grid, and C ρ is the constant-pressure heat capacity of the fluid, T is the temperature, k is the thermal conductivity of the fluid, Q is the heat source inside the fluid, and ▽ is the Hamiltonian operator.

4. The method for simulating the dynamics process of insulation injection molding of submarine cable extrusion molding joints according to claim 2 is characterized in that: The injection molding solid-fluid heat transfer model uses the following formula to describe the temperature distribution of the fluid inside the injection mold during the injection molding process: The injection molding solid-fluid heat transfer model uses the following formula to describe the temperature distribution of the solid inside the injection mold during the injection molding process: Where ρ is the density of the fluid, C ρ is the constant pressure heat capacity of the fluid, T is the temperature, t is the time, u is the velocity of the fluid, k is the thermal conductivity of the fluid, Q is the heat source inside the fluid, τ is the viscous stress tensor, ρ g is the density of the solid, C ρg is the constant pressure heat capacity of the solid, k g is the thermal conductivity of the solid, Q c is the heat source inside the solid, and ▽ is the Hamiltonian operator.

5. The method for simulating the dynamics process of insulation injection molding of submarine cable extrusion molding joints according to claim 2 is characterized in that: The recovery insulating melt viscosity model is: The stress-strain constitutive relation of the restored insulating melt is: τ=η(v+(v) T ); Among them, η is the viscosity of the fluid, η ∞ is the infinite shear viscosity, η0 is the zero shear viscosity, β is the relaxation time, v is the shear rate, n is the power law exponent, α is the temperature coefficient, T is the temperature, T0 is the initial temperature, and τ is the viscous stress tensor.

6. The method for simulating the dynamics process of insulation injection molding of submarine cable extrusion molding joints according to claim 2 is characterized in that: The injection molding phase field model is: in, is the phase field variable, Indicates the restoration of the insulating fuse. represents air, t is time, u is fluid velocity, γ is mobility, γ=ξ 2 χ, ξ are the thickness control parameters for restoring the interface between the insulating melt and the air, which are determined according to the size of the finite element grid. χ is the migration adjustment parameter, and ψ is the auxiliary phase field variable. λ is the mixing energy density, σ s is the surface tension coefficient, and ▽ is the Hamiltonian operator.

7. The method for simulating the dynamics process of insulation injection molding of submarine cable extrusion molding joints according to claim 2 is characterized in that: The initial values ​​include the solid temperature, fluid velocity, force, temperature and volume fraction distribution at the initial moment; the force includes the pressure, gravity, viscous stress and volume force caused by the surface tension of the two-phase fluid. Based on the recovery insulation injection molding dynamics simulation model, the initial value, the boundary condition and the finite element mesh, the recovery insulation injection molding process of the submarine cable extrusion molding joint is simulated, and the velocity field, force field, temperature field and volume fraction distribution in the recovery insulation injection molding process are iteratively calculated, specifically including: Simulating the insulation recovery injection molding process of the submarine cable extrusion molded joint based on the initial value, the boundary condition and the finite element mesh; For any moment in the process of restoring insulation injection molding, calculate the velocity, force, temperature and material parameters of the fluid at the current moment; According to the velocity, force, temperature and material parameters of the fluid at the current moment, the injection molding dynamics model, the injection molding solid-fluid heat transfer model and the restored insulating melt stress-strain constitutive relationship are used to calculate the velocity, force and temperature of the fluid at the next moment to obtain the velocity field, force field and temperature field; According to the volume fraction distribution of the fluid at the current moment and the velocity of the fluid at the next moment, the injection molding phase field model is used to calculate the position distribution of the fluid and determine the volume fraction distribution of the fluid at the next moment; According to the material parameters and volume fraction distribution of the fluid at the next moment, the density, viscosity, constant-pressure heat capacity and thermal conductivity of the fluid at the interface are calculated.

8. The method for simulating the dynamics process of insulation injection molding of submarine cable extrusion molding joints according to claim 7 is characterized in that: The volume fraction distribution of the fluid is determined using the following formula: V f1 +V f2 =1; Among them, V f1 To restore the volume fraction of the insulating melt, V f2 is the volume fraction of air, φ is the phase field variable, Indicates the restoration of the insulating fuse. Indicates air.

9. The method for simulating the dynamics process of insulation injection molding of submarine cable extrusion molding joints according to claim 7 is characterized in that: The density, viscosity, constant pressure heat capacity and thermal conductivity of the fluid at the interface are calculated using the following formulas: r s =ρ1V f1 +p2V f2 ; or s =η1V f1 +η2V f2 ; C ρs =C ρ1 V f1 +C ρ2 V f2 ; to s =k1V f1 +k2V f2 ; Among them, ρ s is the density of the fluid at the interface, ρ1 is the density of the restored insulating melt, ρ2 is the density of air, η s is the viscosity of the fluid at the interface, η1 is the viscosity of the restored insulating melt, η2 is the viscosity of the air, C ρs is the constant pressure heat capacity of the fluid at the interface, C ρ1 To restore the constant pressure heat capacity of the insulating melt, C ρ2 is the constant pressure heat capacity of air, k s is the thermal conductivity of the fluid at the interface, k1 is the thermal conductivity of the restored insulating melt, k2 is the thermal conductivity of air, V f1 To restore the volume fraction of the insulating melt, V f2 is the volume fraction of air.

10. A submarine cable extrusion molding joint insulation injection molding dynamics process simulation system, applied to the submarine cable extrusion molding joint insulation injection molding dynamics process simulation method according to any one of claims 1 to 9, characterized in that: The submarine cable extrusion molding joint insulation injection molding dynamics process simulation system comprises: A geometry model building module, which is used to build the geometry model of submarine cable extrusion molding joints and set material parameters; A dynamic model building module, used to establish a dynamic simulation model of the recovery insulation injection molding of the submarine cable extrusion molding joint based on the geometric model and material parameters; A condition setting module, used to set the initial value and boundary conditions of the recovery insulation injection molding dynamics simulation model; A meshing module, used for meshing the geometric model to obtain a finite element mesh; A simulation module is used to simulate the recovery insulation injection molding process of the submarine cable extrusion molded joint based on the recovery insulation injection molding dynamics simulation model, the initial value, the boundary condition and the finite element grid, and iteratively calculate the velocity field, force field, temperature field and volume fraction distribution in the recovery insulation injection molding process.

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