Simulation method and system for wind flow heat transfer of high-ground-temperature tunnel

Abstract

The invention discloses a simulation method and system for wind flow heat transfer of a high-ground-temperature tunnel. The method comprises the following steps: constructing a tunnel geometric model containing different heat insulation structures by utilizing drawing software; importing the tunnel geometric model into numerical simulation software, constructing entity units in the numerical simulation software, and dividing grids; initial conditions and boundary conditions are set, numerical simulation is conducted through a finite difference method, and the air flow heat transfer processes in different construction stages and under the heat insulation structure are simulated; and analyzing a numerical simulation result, generating a distribution cloud picture of a temperature field, comparing heat transfer effects of different construction stages and the heat insulation structure, and determining an optimal design scheme. According to the method, the wind flow heat transfer problem in the high-ground-temperature tunnel is systematically solved through tunnel geometric model building, parameter setting, numerical simulation and result analysis, scientific basis and actual guidance are provided for tunnel engineering by simulating different heat insulation structures and the heat transfer process of the construction stage, and the safety and efficiency of the engineering are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of air flow heat transfer simulation, in particular to a simulation method and system for air flow heat transfer in high-temperature tunnels. BACKGROUND

[0002] With the rapid development of urban and infrastructure construction, tunnels as important transportation and energy channels are increasingly used in high-temperature environments. High-temperature tunnels generally refer to tunnel environments with surface temperatures much higher than normal temperatures, which impose strict requirements on the design, construction, and operation of tunnels. High temperatures not only increase the thermal load of tunnels but also have negative impacts on tunnel structural materials, construction personnel, and equipment, and even affect the long-term stability and service life of tunnels.

[0003] In high-temperature tunnel projects, due to high ground temperatures, air flow heat transfer in tunnels becomes an important factor affecting tunnel construction and operation. Existing heat transfer simulation methods mainly focus on heat and mass transfer in water bodies or other environments and do not fully consider the special requirements of high-temperature environments, which makes the accuracy and reliability of existing methods insufficient in high-temperature environments, resulting in the inability to comprehensively evaluate the heat flow distribution and air flow dynamics inside the tunnel. Moreover, these methods cannot reflect the heat transfer characteristics of different construction stages and different tunnel structure forms when applied to air flow heat transfer in high-temperature tunnels, which has certain limitations. Based on this, the present application proposes a simulation method for air flow heat transfer in high-temperature tunnels to improve the accuracy and practicality of simulation. SUMMARY

[0004] The present application provides a simulation method and system for air flow heat transfer in high-temperature tunnels to solve the problem of insufficient accuracy and reliability of existing heat transfer simulation methods in high-temperature tunnels, the inability to comprehensively evaluate the heat flow distribution and air flow dynamics inside the tunnel, and the inability to reflect the heat transfer characteristics of different construction stages and different tunnel structure forms.

[0005] According to a first aspect, a simulation method for air flow heat transfer in high-temperature tunnels is provided in an embodiment, the method comprising:

[0006] constructing a tunnel geometric model containing different thermal insulation structures using drawing software;

[0007] importing the tunnel geometric model into a numerical simulation software, constructing solid elements, and dividing grids in the numerical simulation software;

[0008] setting initial conditions and boundary conditions and performing numerical simulation using the finite difference method to simulate the air flow heat transfer process under different construction stages and thermal insulation structures, wherein a multi-field coupling method is used to simulate the interaction of multiple physical fields;

[0009] The numerical simulation results are analyzed, and the distribution cloud of the temperature field is generated, the heat transfer effects of different construction stages and heat insulation structures are compared, and the optimal design scheme is determined.

[0010] Further, a tunnel geometric model containing different heat insulation structures is constructed by using drawing software, specifically including:

[0011] A tunnel lining structure plan is drawn in AutoCAD, and the length, width and height of the tunnel are set;

[0012] Different heat insulation layer thicknesses are set on the tunnel wall, and different heat insulation structures include single-layer heat insulation, double-layer heat insulation and off-wall heat insulation.

[0013] Further, the tunnel geometric model is imported into a numerical simulation software, specifically including:

[0014] The numerical simulation software includes Ansys, Fluent or Comsol.

[0015] Further, the initial conditions and boundary conditions are set, specifically including:

[0016] The condition parameters set include wind speed, temperature, pressure parameters and different heat insulation material attribute parameters.

[0017] Further, the finite difference method is used for numerical simulation, specifically including:

[0018] The finite difference equation is established and iterative calculation is performed, and when the calculation error of the tunnel environment temperature before and after two times is less than the preset value, the iteration is terminated, and the temperature values of all grid nodes of the tunnel surrounding rock-structure-environment are output.

[0019] Further, a multi-field coupling method is used to simulate the interaction of multiple physical fields, specifically including:

[0020] In the simulation of the non-steady state temperature field of the tunnel surrounding rock-structure in high-altitude areas using multi-physical field coupling finite element software, and considering the convection in the tunnel, in addition to the basic heat conduction equation, a formula describing the convective heat transfer is also introduced, specifically as follows:

[0021] Surrounding rock-structure heat transfer, i.e. heat conduction:

[0022] The heat transfer between the surrounding rock and the lining material satisfies the Fourier law, and the main form of heat transfer is heat conduction, and the non-steady state heat transfer formula is as follows:

[0023]

[0024] Where T represents temperature, unit is ℃; λ i (T) is the thermal conductivity of the material, which is a function of T, unit is W / (m·℃). is the gradient operator; Q represents the heat source generated per unit volume, with the unit of W / m 3 ;

[0025] Heat exchange between structure surface and tunnel air flow:

[0026] Under the action of air flow in the tunnel, the tunnel surface first exchanges heat with the surrounding rock surface during the construction period, and then exchanges heat with the primary support surface and the secondary lining surface as the construction process develops. This process meets Newton's cooling law, which is in the form of Neumann in the numerical simulation software as follows:

[0027] q = hA(T 表面 -T 流体 )

[0028] In the formula, q is the convective heat transfer, with the unit of W; h is the convective heat transfer coefficient, with the unit of W / (m 2 ·℃); A is the heat transfer area, with the unit of m 2 ; T surface and T fluid are the temperatures of the solid surface and the surrounding fluid, respectively, with the unit of ℃;

[0029] Energy conservation of tunnel temperature field:

[0030] For a system that considers the convective heat transfer of air flow in the tunnel, the energy conservation equation of the temperature field will combine the heat conduction, convection, and possibly the heat radiation term, which is generally expressed as:

[0031]

[0032] In the formula, u is the flow velocity vector; qrad is the radiation heat transfer, which is not considered in the study; Q is the hydration heat of concrete, with the unit of kJ / kg, and the hydration heat formula is as follows:

[0033]

[0034] The derivative with respect to time t gives the transient hydration heat release formula of concrete as follows:

[0035]

[0036] In the formula, t is the hydration heat release time of cement, with the unit of d; Q0 is the hydration heat release per unit mass of cement; g and b are constants; after the primary support and secondary lining are constructed, they need to be set as heat sources and substituted into the transient hydration heat release formula of concrete. Considering the transient hydration heat release of concrete, it is helpful to more accurately analyze the distribution rule and evolution process of the tunnel temperature field.

[0037] Further, the numerical simulation results are analyzed, and the distribution cloud of the temperature field is generated, which specifically includes:

[0038] Import the simulation data file in Tecplot or ParaView, and draw the distribution cloud of the temperature field.

[0039] Further, compare the heat transfer effects of different construction stages and insulation structures to determine the optimal design scheme, specifically including:

[0040] By comparing the maximum temperature on the lining or the maximum ambient temperature of different insulation structures, the effects of single-layer insulation, double-layer insulation, different insulation layer thickness, and off-wall insulation are compared to determine the optimal insulation scheme.

[0041] According to the simulation results of different construction stages, adjust the construction scheme to improve the construction efficiency and safety.

[0042] According to the second aspect, an embodiment provides a simulation system for air flow heat transfer in high-temperature tunnels, the system comprising:

[0043] A model construction module for constructing a tunnel geometric model containing different insulation structures using drawing software;

[0044] A numerical simulation module for importing the tunnel geometric model into a numerical simulation software, constructing solid elements, and dividing grids in the numerical simulation software;

[0045] Setting initial conditions and boundary conditions, and using finite difference method for numerical simulation to simulate the air flow heat transfer process under different construction stages and insulation structures, wherein a multi-field coupling method is used to simulate the interaction of multiple physical fields;

[0046] A result analysis module for analyzing the numerical simulation results and generating the distribution cloud of the temperature field, comparing the heat transfer effects of different construction stages and insulation structures, and determining the optimal design scheme.

[0047] According to the third aspect, an embodiment provides an electronic device, the device comprising: a processor and a memory;

[0048] The memory is used to store one or more program instructions;

[0049] The processor is used to run one or more program instructions to execute the steps of the simulation method for air flow heat transfer in high-temperature tunnels as described in any one of the above.

[0050] According to the fourth aspect, an embodiment provides a computer-readable storage medium, the computer-readable storage medium storing a computer program, the computer program being executed by a processor to implement the steps of the simulation method for air flow heat transfer in high-temperature tunnels as described in any one of the above.

[0051] The application provides a simulation method and system for air flow heat transfer in a high-temperature tunnel, a tunnel geometric model containing different heat insulation structures is constructed by using drawing software; the tunnel geometric model is imported into numerical simulation software, entity units are constructed in the numerical simulation software, and grids are divided; initial conditions and boundary conditions are set, and numerical simulation is performed by using a finite difference method to simulate the air flow heat transfer process under different construction stages and heat insulation structures, wherein a multi-field coupling method is used to simulate the interaction of multiple physical fields; the numerical simulation results are analyzed, and a temperature field distribution cloud map is generated, the heat transfer effects of different construction stages and heat insulation structures are compared, and an optimal design scheme is determined. The application solves the air flow heat transfer problem in a high-temperature tunnel by constructing a tunnel geometric model, setting parameters, numerical simulation and result analysis, provides a scientific basis and practical guidance for a tunnel project by simulating the heat transfer process of different heat insulation structures and construction stages, and improves the safety and efficiency of the project. BRIEF DESCRIPTION OF DRAWINGS

[0052] Figure 1 A flowchart of a simulation method for air flow heat transfer in a high-temperature tunnel is provided for an embodiment of the application;

[0053] Figure 2 A specific implementation flowchart of a simulation method for air flow heat transfer in a high-temperature tunnel is provided for an embodiment of the application;

[0054] Figure 3 A tunnel geometric model diagram in a simulation method for air flow heat transfer in a high-temperature tunnel is provided for an embodiment of the application;

[0055] Figure 4 A Comsol numerical simulation software interface in a simulation method for air flow heat transfer in a high-temperature tunnel is provided for an embodiment of the application;

[0056] Figure 5 A logic structure schematic diagram of a simulation system for air flow heat transfer in a high-temperature tunnel is provided for an embodiment of the application. DETAILED DESCRIPTION

[0057] The present invention will be further described in detail below by means of specific embodiments in conjunction with the accompanying drawings. Similar elements in different embodiments are numbered with associated similar elements. In the following embodiments, many detailed descriptions are provided to enable the present application to be better understood. However, those skilled in the art will readily appreciate that some of the features may be omitted in different circumstances, or may be replaced by other elements, materials, or methods. In some cases, some operations related to the present application are not shown or described in the specification. This is to avoid the core portion of the present application being overwhelmed by excessive descriptions, and for those skilled in the art, it is not necessary to describe these related operations in detail. They will fully understand the related operations based on the description in the specification and the general technical knowledge in the art.

[0058] In addition, the features, operations, or characteristics described in the specification may be combined in any appropriate manner to form various embodiments. Furthermore, the steps or actions in the method description may be reordered or adjusted in a manner readily apparent to those skilled in the art. Therefore, the various sequences in the specification and drawings are provided solely for the purpose of clearly describing a particular embodiment and are not intended to be mandatory, unless otherwise specified.

[0059] The specific technical issues of airflow heat transfer in high-temperature tunnels include:

[0060] 1. Heat conduction and convection simulation in high temperature environment:

[0061] Due to the high ground temperature in the tunnel, heat conduction and convection problems occur, and traditional methods are difficult to accurately simulate these complex thermodynamic processes.

[0062] 2. Accurate simulation of multi-field coupling effects:

[0063] In a tunnel environment, multiple physical fields such as wind speed field, temperature field and concentration field are coupled with each other, and a single physical field simulation cannot fully reflect the actual situation.

[0064] 3. Improve simulation accuracy and practicality:

[0065] The existing simulation methods have limitations in their application to high geothermal tunnels, and the simulation accuracy and practicality of the results need to be improved.

[0066] 4. Consider the construction phase:

[0067] Consider the ventilation and heat transfer issues during tunnel construction and operation

[0068] 5. Consider the heat transfer of different tunnel structural systems:

[0069] The heat transfer problems of ordinary composite lining, sandwich lining and off-wall lining structures of tunnels are considered.

[0070] The present application proposes a wind flow heat transfer simulation method for high-temperature tunnels, aiming to improve the accuracy of simulating the heat flow and wind flow dynamics in high-temperature tunnel environments. This method combines the latest achievements in modern thermodynamics, fluid mechanics, and computational science, through the establishment of mathematical models in high-temperature environments, the use of advanced numerical calculation methods, and real-time data feedback and parameter calibration, to effectively predict the heat flow distribution and wind flow characteristics in tunnels.

[0071] Specifically, the wind flow heat transfer simulation method of the present application includes the following main aspects:

[0072] 1. Mathematical model establishment:

[0073] - Heat transfer model: By considering the thermal conductivity of tunnel structure materials, the distribution of internal heat sources, and the change of environmental temperature in detail, a three-dimensional heat transfer model is established, which comprehensively considers conduction, convection, and radiation.

[0074] - Wind flow dynamics model: Based on the Navier-Stokes equation and energy equation, a dynamic model is established to describe the behavior of wind flow in high-temperature environments, simulating the influence of wind flow on heat transfer.

[0075] 2. Numerical calculation method:

[0076] - High-performance computing: Finite Volume Method (FVM) or Finite Element Method (FEM) is used for numerical simulation, and fine grid division is performed to ensure the accuracy and efficiency of the calculation.

[0077] - Real-time data feedback: Through real-time monitoring of temperature and wind speed data inside the tunnel, model parameters are dynamically adjusted to optimize the accuracy of simulation results.

[0078] 3. Parameter calibration and verification:

[0079] - Experimental data verification: The model is calibrated using actual measured data to ensure the consistency of the simulation results with the real situation.

[0080] - Sensitivity analysis: Sensitivity analysis is performed on key parameters to identify the factors that have the greatest impact on simulation results, to optimize the reliability of the model.

[0081] 4. Application and optimization:

[0082] - Design optimization: Based on the simulation results, the layout of the ventilation system of the tunnel is optimized, and appropriate thermal insulation materials are selected to improve the energy efficiency and thermal management effect of the tunnel.

[0083] - Operation strategy formulation: Based on simulation results and real-time data, effective operation strategies are formulated to achieve accurate control of the temperature and comfort inside the tunnel.

[0084] Specifically, the first embodiment of the present invention provides a method for simulating heat transfer in high ground temperature tunnels. Figure 1 and Figure 2 Provide detailed explanation.

[0085] like Figure 1 As shown, in step S100, a tunnel geometric model including different thermal insulation structures is constructed using drawing software.

[0086] Specifically, CAD software (such as AutoCAD or SolidWorks) is used to construct a tunnel geometry model, such as Figure 3 According to the actual tunnel engineering data, different insulation structures are included, such as single-layer insulation and double-layer insulation.

[0087] Specific example operations:

[0088] -Draw the tunnel section in AutoCAD and set the length, width and height of the tunnel.

[0089] - Different insulation thicknesses are set on the tunnel wall, such as single-layer insulation (10 cm), double-layer insulation (5 cm rock wool + 5 cm polyurethane foam), or off-wall insulation (air interlayer).

[0090] like Figure 1 As shown, in step S200, the tunnel geometry model is imported into numerical simulation software, solid units are constructed in the numerical simulation software, and a grid is divided.

[0091] Specifically, the two-dimensional CAD drawing is imported into the numerical simulation software, and the solid units are established in the numerical simulation software and then the mesh is divided.

[0092] like Figure 1 As shown, in step S300, initial conditions and boundary conditions are set, and a finite difference method is used to perform numerical simulation to simulate the wind heat transfer process under different construction stages and insulation structures, wherein a multi-field coupling method is used to simulate the interaction of multiple physical fields.

[0093] Specifically, in the variable setting of the numerical simulation software, set the parameters in the boundary conditions. Figure 4 As shown, by using numerical simulation software (such as Ansys or Fluent or Comsol), the initial conditions and boundary conditions of the wind flow in the tunnel are set, including parameters such as wind speed, temperature, pressure, and different insulation material properties.

[0094] Specific example operations:

[0095] -Use Ansys or Fluent to import the tunnel geometry model.

[0096] - Set fluid properties, including wind speed (0.5 m / s), inlet temperature (25°C), outlet temperature (30°C).

[0097] - Set material properties of the tunnel wall, such as thermal conductivity and specific heat capacity of rock wool and polyurethane foam.

[0098] In this example, finite difference method is used for numerical simulation to simulate the wind flow heat transfer process under different construction stages and insulation structures.

[0099] Finite difference method is a numerical method used to solve approximate solutions of differential equations. This method divides the continuous spatial and temporal domain into a series of discrete grid points, converts the differential equation into discrete difference equations, and then solves these discrete equations to obtain the approximate solution of the original differential equation.

[0100] The basic principle of finite difference method:

[0101] Grid division: First, divide the continuous spatial and temporal domain into a series of discrete grid points (in the pre-processing software);

[0102] Difference formula construction: Use difference formula (such as forward difference, backward difference or central difference) to approximate the differential operator, here using central difference;

[0103] Forming difference equation: Replace the differential operator in the differential equation with the corresponding difference formula to form the difference equation;

[0104] Apply initial conditions and boundary conditions: Discretize and apply these conditions to the difference equation according to the specific conditions of the problem;

[0105] Solve algebraic equations: Solve the discretized algebraic equations to get the numerical solution at the grid points;

[0106] Result post-processing: Analyze the solution, which may need interpolation or smoothing, and perform error analysis and stability analysis.

[0107] Specific example operation:

[0108] - Establish initial conditions and boundary conditions.

[0109] - Use multi-field coupling method to simulate the interaction of wind speed field, temperature field and concentration field.

[0110] When using multi-physical field coupling finite element software to simulate the non-steady state temperature field of tunnel surrounding rock-structure in high altitude area and considering the convection in the tunnel, in addition to the basic heat conduction equation, the formula describing the convective heat transfer needs to be introduced, which involves the following mathematical formulas:

[0111] (1) Surrounding rock-structure heat transfer, i.e. heat conduction:

[0112] The heat transfer between the surrounding rock and the lining material satisfies the Fourier law, and the main form of heat transfer is thermal conduction. The unsteady heat transfer formula is as follows:

[0113]

[0114] wherein T represents temperature, the unit is ℃; λ i (T) is the thermal conductivity of the material, which is a function of T, the unit is W / (m·℃); is the gradient operator; Q represents the heat source generated per unit volume, the unit is W / m 3 ;

[0115] (2) Heat exchange between the structure surface and the tunnel air flow:

[0116] Under the action of the air flow in the tunnel, the tunnel surface first undergoes convective heat exchange with the surrounding rock surface, and then undergoes convective heat exchange with the primary support surface and the secondary lining surface as the construction process develops. This process satisfies the Newton cooling law, and the Noyman form adopted in the numerical simulation software is as follows:

[0117] q = hA(T 表面 -T 流体 )

[0118] In the formula, q is the convective heat transfer, the unit is W; h is the convective heat transfer coefficient, the unit is W / (m 2 ·℃); A is the heat transfer area, the unit is m 2 ; T surface and T fluid are the temperatures of the solid surface and the surrounding fluid, respectively, the unit is ℃;

[0119] (3) Energy conservation of the tunnel temperature field:

[0120] For a system considering the convective heat transfer of the air flow in the tunnel, the energy conservation equation of the temperature field will combine the heat conduction, convection and possible heat radiation terms, and is usually expressed as:

[0121]

[0122] In the formula, u is the flow velocity vector; qrad is the radiation heat transfer, which is not considered in the study; Q is the hydration heat of the concrete, the unit is kJ / kg, and the hydration heat formula is as follows:

[0123]

[0124] The derivative with respect to time t gives the transient hydration heat formula of the concrete as follows:

[0125]

[0126] In the formula, t is the time of cement hydration heat release, unit is d; Q0 is the unit mass of cement hydration heat release; g and b are constants; after the initial support and secondary lining are constructed, it needs to be set as a heat source and substituted into the formula of transient hydration heat release of concrete, considering the transient hydration heat release of concrete, which helps to more accurately analyze the distribution rule and evolution process of tunnel temperature field.

[0127] - Step-by-step iterative calculation to obtain stable heat transfer process.

[0128] Through finite difference method, the iteration can be stopped when the error between the current calculation result and the previous result is less than 10^-5.

[0129] As shown in Figure 1 , in step S400, the numerical simulation results are analyzed, and the distribution cloud chart of temperature field is generated, the heat transfer effects of different construction stages and heat insulation structures are compared, and the optimal design scheme is determined.

[0130] Specifically, the simulation results are imported into post-processing software (such as Tecplot or ParaView) to generate the distribution chart of air flow heat transfer in the tunnel, and the results are analyzed and optimized.

[0131] Specific example operation:

[0132] - Import simulation data file (such as velocity.dat) in Tecplot or ParaView.

[0133] - Generate the distribution cloud chart of temperature field.

[0134] - Analyze the heat transfer effects of different heat insulation structures and construction stages to find the optimal design scheme.

[0135] The main purpose is to compare the effects of single-layer insulation, double-layer insulation, different insulation thickness, and off-wall type by comparing the maximum temperature on the lining of different heat insulation structures or the maximum ambient temperature, to determine the optimal heat insulation scheme. For example, compare the effects of single-layer sandwich insulation and off-wall type (air layer) lining structure with the same thickness, and analyze which one has better insulation effect by comparing the maximum temperature on the secondary lining. Further, compare the decreasing trend of the maximum temperature on the secondary lining when the thickness is different, and then give the optimal heat insulation structure and thickness.

[0136] Different construction stages mean that the construction excavation progress is different, and the temperature of the surrounding rock of the tunnel is different, so the heat insulation structure and the thickness of the heat insulation layer should be adjusted according to the different rock temperatures. Therefore, according to the simulation results of different construction stages, the construction scheme is adjusted to improve the construction efficiency and safety.

[0137] The embodiment of the present application provides a simulation method for air flow heat transfer in a high-temperature tunnel, which systematically solves the air flow heat transfer problem in the high-temperature tunnel by constructing a tunnel geometric model, setting parameters, performing numerical simulation and result analysis. The simulation of the heat transfer process of different heat insulation structures and construction stages provides a scientific basis and practical guidance for the tunnel engineering, and improves the safety and efficiency of the engineering. The technical scheme is suitable for the design, construction and operation stages of the high-temperature tunnel, and can be popularized and applied in other similar engineering environments.

[0138] Corresponding to the simulation method for air flow heat transfer in a high-temperature tunnel disclosed above, the embodiment of the present application also discloses a simulation system for air flow heat transfer in a high-temperature tunnel, as shown in Figure 5 The simulation system specifically comprises:

[0139] A model construction module is configured to construct a tunnel geometric model containing different heat insulation structures by using drawing software.

[0140] A numerical simulation module is configured to import the tunnel geometric model into numerical simulation software, construct entity units in the numerical simulation software, and divide grids.

[0141] Initial conditions and boundary conditions are set, and numerical simulation is performed by using a finite difference method to simulate the air flow heat transfer process under different construction stages and heat insulation structures, wherein a multi-field coupling method is used to simulate the interaction of multiple physical fields.

[0142] A result analysis module is configured to analyze the numerical simulation results, generate a distribution nephogram of a temperature field, compare the heat transfer effects of different construction stages and heat insulation structures, and determine an optimal design scheme.

[0143] It should be noted that the detailed description of the simulation system for air flow heat transfer in a high-temperature tunnel provided by the embodiment of the present application can refer to the related description of the simulation method for air flow heat transfer in a high-temperature tunnel provided by the embodiment of the present application, which will not be repeated here.

[0144] In addition, the embodiment of the present application also provides an electronic device, which comprises a processor and a memory; the memory is configured to store one or more program instructions; and the processor is configured to run the one or more program instructions to execute the steps of the simulation method for air flow heat transfer in a high-temperature tunnel according to any one of the above.

[0145] It should be noted that the detailed description of the electronic device provided by the embodiment of the present application can refer to the related description of the simulation method for air flow heat transfer in a high-temperature tunnel provided by the embodiment of the present application, which will not be repeated here.

[0146] In addition, the embodiment of the present application further provides a computer readable storage medium, and the computer readable storage medium stores a computer program, and the computer program is executed by a processor to realize the steps of the simulation method for the air flow heat transfer of a high-temperature tunnel.

[0147] It should be noted that the detailed description of the computer readable storage medium provided by the embodiment of the present application can refer to the related description of the simulation method for the air flow heat transfer of a high-temperature tunnel provided by the embodiment of the present application, and will not be repeated here.

[0148] Those skilled in the art can understand that all or part of the functions of the various methods in the above embodiments can be realized by hardware or by a computer program. When all or part of the functions in the above embodiments are realized by a computer program, the program can be stored in a computer readable storage medium, and the storage medium can include a read-only memory, a random access memory, a magnetic disk, an optical disk, a hard disk, etc. The above functions are realized by executing the program by a computer. For example, the program is stored in a memory of a device, and when the program in the memory is executed by a processor, the above functions are realized. In addition, when all or part of the functions in the above embodiments are realized by a computer program, the program can also be stored in a server, another computer, a disk, an optical disk, a flash disk or a mobile hard disk, etc. The program is downloaded or copied into the memory of a local device, or the system of the local device is updated, and when the program in the memory is executed by a processor, the above functions are realized.

[0149] The above application of specific examples is used to describe the present application, which is only used to help understand the present application, and does not limit the present application. According to the idea of the present application, those skilled in the art can make several simple deductions, deformations or substitutions.

Claims

1. A method for simulating heat transfer in high ground temperature tunnels, characterized in that: The method comprises: Use drawing software to construct a tunnel geometry model including different insulation structures; Importing the tunnel geometry model into numerical simulation software, constructing entity units in the numerical simulation software, and dividing the mesh; Initial and boundary conditions were set, and the finite difference method was used to perform numerical simulations to simulate the wind heat transfer process under different construction stages and insulation structures. The multi-field coupling method was used to simulate the interaction of multiple physical fields. The numerical simulation results are analyzed and a temperature field distribution cloud map is generated to compare the heat transfer effects of different construction stages and insulation structures to determine the optimal design scheme.

2. A method for simulating airflow heat transfer in a high ground temperature tunnel according to claim 1, characterized in that: The geometric model of the tunnel with different insulation structures was constructed using drawing software, including: Draw the tunnel lining structure plan in AutoCAD and set the tunnel length, width and height; Different insulation layer thicknesses are set on the tunnel wall, and different insulation structures include single-layer insulation, double-layer insulation and off-wall insulation.

3. The method for simulating airflow heat transfer in a high ground temperature tunnel according to claim 1, characterized in that: Importing the tunnel geometry model into numerical simulation software specifically includes: The numerical simulation software includes Ansys, Fluent or Comsol.

4. The method for simulating airflow heat transfer in a high ground temperature tunnel according to claim 1, characterized in that: Set the initial and boundary conditions, including: The set condition parameters include wind speed, temperature, pressure parameters and different insulation material property parameters.

5. The method for simulating heat transfer in high ground temperature tunnels according to claim 1, characterized in that: Finite difference method is used for numerical simulation, including: A finite difference equation is established and iterative calculation is performed. When the error between the two calculations of the tunnel ambient temperature is lower than the preset value, the iteration is terminated and the temperature values ​​of all grid nodes of the tunnel surrounding rock, structure and environment are output.

6. The method for simulating airflow heat transfer in a high ground temperature tunnel according to claim 1, characterized in that: Multi-field coupling methods are used to simulate the interaction of multiple physical fields, including: When using multi-physics coupled finite element software to simulate the unsteady temperature field of the surrounding rock and structure of tunnels at high altitudes and considering convection within the tunnel, in addition to the basic heat conduction equation, it is also necessary to introduce a formula to describe convection heat transfer, as follows: Heat transfer from surrounding rock to structure, i.e. heat conduction: The heat transfer between the surrounding rock and the lining material satisfies Fourier's law. The main form of heat transfer is heat conduction. The unsteady heat transfer formula is as follows: Where T represents temperature in °C; λ i (T) is the thermal conductivity of the material, which is a function of T and is expressed in W / (m·°C); is the gradient operator; Q represents the heat source generated per unit volume, and the unit is W / m 3 ; Heat exchange between structure surface and tunnel airflow: Under the action of the airflow in the tunnel, convection heat transfer first occurs with the surrounding rock surface during the tunnel construction period, and then with the primary support surface and the secondary lining surface as the construction progresses. This process complies with Newton's law of cooling. The Neumann form used in the numerical simulation software is as follows: q=hA(T 表面 -T 流体 ) Where q is the convective heat transfer, the unit is W; h is the convective heat transfer coefficient, the unit is W / (m 2 ·℃); A is the heat exchange area, unit is m 2 ; Tsurface and Tfluid are the temperatures of the solid surface and the surrounding fluid, respectively, in °C; Energy conservation of tunnel temperature field: For a system considering convective heat transfer through airflow in a tunnel, the energy conservation equation for the temperature field combines heat conduction, convection, and possible heat radiation terms, and is usually expressed as: Where u is the velocity vector; qrad is the radiation heat transfer, which is not considered in this study; Q is the hydration heat release of concrete, in kJ / kg. The hydration heat release formula is as follows: The formula for the transient hydration heat release of concrete is derived by taking the derivative of time t as follows: Where t is the time of cement hydration heat release, in days; Q0 is the heat release per unit mass of cement hydration; g and b are constants. After the primary support and secondary lining are installed, they need to be set as heat sources and substituted into the formula for the transient hydration heat release of concrete. Considering the transient hydration heat release of concrete will help to more accurately analyze the distribution law and evolution process of the tunnel temperature field.

7. The method for simulating airflow heat transfer in a high ground temperature tunnel according to claim 1, characterized in that: Analyze the numerical simulation results and generate a temperature field distribution cloud map, including: Import the simulation data file into Tecplot or ParaView and draw the distribution cloud diagram of the temperature field.

8. The method for simulating airflow heat transfer in a high ground temperature tunnel according to claim 1, characterized in that: Compare the heat transfer effects of different construction stages and insulation structures to determine the optimal design solution, including: By comparing the maximum temperature on the lining of different insulation structures or the maximum ambient temperature, we can compare the effects of single-layer insulation, double-layer insulation, different insulation layer thicknesses, and off-wall insulation to determine the optimal insulation solution. According to the simulation results of different construction stages, the construction plan is adjusted to improve construction efficiency and safety.

9. A simulation system for heat transfer in high ground temperature tunnels, characterized in that: The system comprises: Model building module, used to build tunnel geometry models including different insulation structures using drawing software; A numerical simulation module, used for importing the tunnel geometric model into numerical simulation software, constructing entity units in the numerical simulation software, and dividing the grid; Initial and boundary conditions were set, and the finite difference method was used to perform numerical simulations to simulate the wind heat transfer process under different construction stages and insulation structures. The multi-field coupling method was used to simulate the interaction of multiple physical fields. The result analysis module is used to analyze the numerical simulation results and generate a temperature field distribution cloud map to compare the heat transfer effects of different construction stages and insulation structures and determine the optimal design solution.

10. An electronic device, characterized in that: The device includes: a processor and a memory; The memory is used to store one or more program instructions; The processor is used to run one or more program instructions to execute the steps of the method for simulating airflow heat transfer in a high ground temperature tunnel as described in any one of claims 1 to 8.

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