A whole-process cold-chain logistics safety prediction system and method

Abstract

This invention discloses a full-process cold chain logistics safety prediction system and method, belonging to the field of packaging engineering and logistics technology. The invention aims to solve the problems of existing cold chain analysis tools, which are based on static temperature assumptions and lack mechanical coupling, resulting in large prediction errors and limited functionality. The system includes modules for geometric modeling, mesh generation, boundary condition setting, solution calculation, and result early warning. Key technical points include: supporting user input of dynamic external temperature curves that change over time to simulate real logistics environments; and integrating vibration parameters from sea, land, and air transportation modes to achieve thermo-mechanical coupling simulation. This method can accurately predict product temperature changes and packaging structure responses under complex dynamic environments, automatically calculate safe durations, and visually warn of over-temperature risks, effectively guiding cold chain packaging design and logistics risk management. It is applicable to the full-process cold chain safety assessment of vaccines, fresh produce, and frozen foods.

Description

Technical Field

[0001] This invention relates to the fields of packaging engineering and logistics technology, and in particular to a whole-process cold chain logistics safety prediction system and method. Background Technology

[0002] Cold chain logistics is a crucial link in ensuring the quality and safety of perishable products such as food and pharmaceuticals. Current cold chain packaging design and safety assessment technologies primarily rely on simulation software based on finite element analysis. However, existing technologies suffer from the following drawbacks: First, current simulation tools typically rely on the simplified assumption of a constant external ambient temperature, such as performing antifreeze or cold-keeping analyses only for single, constant low- or high-temperature environments. Real-world logistics processes (such as cross-climate zone transportation and loading / unloading at distribution centers) involve complex dynamic temperature changes (such as diurnal temperature variations and the door-opening effect). Predictions based on static assumptions often deviate significantly from reality, leading to either overly conservative and wasteful packaging designs or insufficient protection that introduces risks.

[0003] Secondly, existing technologies for thermal simulation often neglect the mechanical environmental impact of logistics transportation methods (sea, land, and air transport). Vibrations and impacts during transportation not only affect the integrity of the packaging structure but also cause compression deformation of insulation materials, thereby altering their thermal conductivity. Existing software lacks the ability to couple and analyze dynamic temperature fields with transportation vibration dynamic fields, making it impossible to effectively predict the overall safety of fragile or highly sensitive products in complex logistics environments. Summary of the Invention

[0004] To address the aforementioned technical problems, a first aspect of the present invention provides a full-process cold chain logistics safety prediction system, the system comprising:

[0005] The geometric modeling module is used to automatically generate a three-dimensional geometric model containing the packaging box, insulation layer, and cold or heat source based on the packaging parameters input by the user.

[0006] The mesh generation module is used to perform mesh generation on the three-dimensional geometric model;

[0007] The boundary condition and physics field setting module is used to set the physics field model required for simulation calculations and apply external temperature boundary conditions and mechanical load boundary conditions; the external temperature boundary conditions support inputting dynamic temperature curves that change over time; the mechanical load boundary conditions support selecting transportation methods and applying corresponding vibration parameters.

[0008] The solution calculation module is used to call the solver to perform multiphysics transient simulation based on the three-dimensional geometric model and boundary conditions, and to calculate the temperature field changes and structural response inside the packaging under dynamic external temperature and transportation vibration conditions.

[0009] The results visualization and early warning module is used to output temperature change curves and stress distribution cloud maps, and calculate the safe duration based on the set product safe temperature range.

[0010] Furthermore, the packaging parameters received by the geometric modeling module include: the length, width, height and wall thickness of the packaging box, the thickness of the insulation material, and the length, width and height of the cold source or heat source; the geometric modeling module constructs and assembles the solid models of each component according to the packaging parameters.

[0011] Furthermore, the mesh division module is configured to: divide the packaging box and the air area inside the box using a tetrahedral mesh, divide the cold source or heat source area using a swept mesh, and support user adjustment of the mesh size.

[0012] Furthermore, the physical field model configured by the boundary conditions and physical field setting module includes: a solid heat transfer model for simulating heat conduction of the packaging box and cold source, a fluid heat transfer and laminar flow model for simulating air convection inside the box, and a non-isothermal flow model for simulating temperature and fluid coupling; when the cold source is a phase change material, it also includes a phase change material model and receives phase change temperature and latent heat parameters.

[0013] Furthermore, when applying external temperature boundary conditions, the boundary condition and physics field setting module adopts a dynamic temperature curve mode: by reading the user-uploaded time-temperature data file or the time-temperature points drawn by the user on the interface, it generates a continuous external temperature function. And apply it to the outer surface of the packaging box using the following formula:

[0014]

[0015] in, The outer surface temperature of the enclosure. For time.

[0016] Furthermore, the boundary condition and physics field setting module provides four transportation options—sea, land, air, and custom—when applying mechanical load boundary conditions. The system determines the vibration data based on the user-selected transportation method and applies the base acceleration to the bottom of the packaging box using the following formula:

[0017]

[0018] in, For the basic acceleration of the bottom of the box, For vibration data corresponding to the transportation mode, The interpolation function is used; the solution calculation module uses the thermal-stress coupling interface to calculate the effect of vibration on the temperature field.

[0019] Furthermore, the vibration parameters corresponding to the transportation modes are preset as follows: for sea transport mode, the frequency is 0.1-5Hz and the acceleration is 0.1-0.5g; for land transport mode, the frequency is 5-100Hz and the acceleration is 0.5-1.5g; for air transport mode, the frequency is 10-500Hz and the acceleration is 1.0-3.0g.

[0020] Furthermore, the result visualization and early warning module is configured to: generate key point temperature change curves, and overlay and display the product temperature curve, the external temperature change curve, and the upper and lower limits of the user-defined safe temperature zone on the curve graph; automatically determine whether the product temperature exceeds the safe temperature range, and calculate the duration for which the product temperature remains within the safe range as the safe duration.

[0021] Furthermore, the result visualization and early warning module is also used to: issue an overheating risk warning when the product temperature exceeds the upper limit of the safe temperature zone, and issue an overcooling risk warning when the product temperature is below the lower limit of the safe temperature zone; output the maximum stress value caused by vibration for assessing the safety of the packaging structure.

[0022] A second aspect of the present invention also provides a method for predicting the safety of the entire cold chain logistics process, comprising the following steps:

[0023] S1. Input packaging size parameters, thermal conductivity of insulation material, cold source phase change parameters, initial product temperature and safe temperature range;

[0024] S2. Generate a 3D geometric model of the packaging and perform mesh generation;

[0025] S3. Set up a physical field model and apply external temperature boundary conditions and mechanical load boundary conditions; wherein, the external temperature boundary condition is a dynamic temperature curve that changes with time, and the mechanical load boundary condition automatically matches vibration parameters according to the selected transportation method.

[0026] S4. Perform multiphysics transient simulation calculations to solve the coupled response of the temperature field and the mechanical field;

[0027] S5 outputs a temperature cloud map and a product temperature change curve superimposed with the external temperature curve, calculates the safe duration, and provides early warning of over-temperature risks.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] This invention achieves accurate predictions in dynamic environments: It breaks through the limitations of traditional static temperature assumptions by introducing dynamic external temperature curve boundary conditions, enabling precise simulation of temperature fluctuations in real-world scenarios such as diurnal temperature differences, geographical cross-regional travel, and the "door-opening effect." Combined with a transient solver, the predicted safety duration more closely reflects the actual logistics process, effectively avoiding prediction distortion caused by environmental simplification.

[0030] A thermo-mechanical coupling-based end-to-end safety assessment system has been constructed: This invention innovatively integrates a solid mechanics module with vibration parameter libraries for various transportation modes (sea, land, and air), enabling the simulation of the impact of transportation vibrations on packaging structures and heat transfer processes. Through thermo-mechanical coupling calculations, it can not only predict product temperature changes but also assess the stress distribution of packaging under vibration, providing more comprehensive safety assurance for the entire transportation process of perishable and fragile products.

[0031] Improved decision-making efficiency and intuitiveness: Through a visualized results output module, the system can automatically calculate and display the "safe duration" of a product within its safe temperature range and provide intuitive warnings of overheating risks. This allows non-simulation professionals to quickly assess the effectiveness of packaging solutions, optimize cold source configuration, and reduce logistics costs while ensuring safety. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the parameter setting interface provided in an embodiment of the present invention, showing the setting controls for packaging size, material parameters, and external temperature input;

[0033] Figure 2 The flowchart for model solving calculation provided in this embodiment of the invention illustrates the processing logic from parameter input to result warning;

[0034] Figure 3 The three-dimensional geometric model diagram of the packaging box, insulation layer and cold source generated for the embodiments of the present invention;

[0035] Figure 4 This is a schematic diagram illustrating the grid division of the packaging box and cold source in an embodiment of the present invention;

[0036] Figure 5 A software user interface layout diagram provided for an embodiment of the present invention;

[0037] Figure 6 This is a transient temperature field cloud map inside the packaging at a specific moment, output by an embodiment of the present invention.

[0038] Figure 7 This is an example diagram of temperature change curves output by an embodiment of the present invention, including product temperature, safe temperature zone, and ambient temperature curves.

[0039] Figure 8 This is a schematic diagram of the input parameter error prompt interface provided in an embodiment of the present invention;

[0040] Figure 9 This is a schematic diagram of the transportation mode selection and vibration parameter setting interface provided in an embodiment of the present invention;

[0041] Figure 10This is a schematic diagram of the vibration curve uploading or drawing interface provided in an embodiment of the present invention.

[0042] Illustrations: 100, Geometric Modeling Module; 200, Mesh Generation Module; 300, Boundary Condition and Physics Field Setting Module; 310, Physics Field Setting Unit; 320, External Temperature Boundary Condition Setting Unit; 330, Mechanical Field and Transportation Mode Setting Unit; 400, Solution Calculation Module; 500, Result Visualization and Early Warning Module. Detailed Implementation

[0043] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0044] This invention provides a system and method for predicting the safety of the entire cold chain logistics process, aiming to solve the technical problems of existing cold chain logistics analysis tools, such as limited functionality, reliance on static temperature assumptions, lack of comprehensive safety assessment, and high barriers to entry. This system supports input of dynamically changing ambient temperature curves, mechanical field simulations of various transportation modes, and thermo-mechanical coupling analysis, enabling accurate prediction and early warning of product temperature response and packaging structure safety throughout the entire cold chain logistics process.

[0045] Example 1

[0046] See Figures 1 to 5 This embodiment provides a full-process cold chain logistics safety prediction system. The system is built on a finite element simulation platform and includes a geometric modeling module 100, a mesh generation module 200, a boundary condition and physical field setting module 300, a solution calculation module 400, and a result visualization and early warning module 500.

[0047] The geometric modeling module 100 is used to automatically generate a 3D geometric model based on the packaging parameters input by the user. The packaging parameters received by this module include two categories: packaging box dimensions and cold source dimensions. The packaging box dimensions include the packaging box length. Packaging box width Packaging box height Packaging box wall thickness and insulation material thickness The dimensions of the cold source include its length. Cold source width and the height of the cold source The geometric modeling module 100 automatically constructs a complete three-dimensional geometric model, including the packaging box, insulation layer, and cold or heat source, based on the above parameters. Figure 3As shown. In this embodiment, the cold source can be in the form of a cold storage agent, a phase change material plate, or a gel cold source package, and the heat source can be a heating element used for antifreeze and heat preservation.

[0048] The mesh generation module 200 is used to mesh the 3D geometric model generated by the geometric modeling module 100. For example... Figure 4 As shown, the meshing module 200 uses tetrahedral meshes to partition the packaging box and the air area inside the box to adapt to complex geometries and ensure computational accuracy; for cold or hot sources, it uses swept meshes to obtain higher mesh quality and computational efficiency in regular geometric regions. The meshing module 200 allows users to manually adjust the mesh size to achieve a balance between computational accuracy and computational efficiency.

[0049] The boundary condition and physics setting module 300 is the core module of this system, used to set the physics model and boundary conditions required for simulation calculations. This module includes a physics setting unit 310, an external temperature boundary condition setting unit 320, and a mechanical field and transportation mode setting unit 330.

[0050] The physics setting unit 310 is used to select and configure the physics models required for simulation. Supported physics models include solid heat transfer models, fluid heat transfer models, laminar flow models, and non-isothermal flow models. Solid heat transfer models are used to simulate heat conduction processes in packaging boxes, insulation materials, and cold or heat sources. Fluid heat transfer models are used in conjunction with laminar flow models to simulate natural and forced convection processes of air within the box. Non-isothermal flow models are used to couple the temperature field with fluid flow calculations. When the user selects a phase change material (PCM) as a cold or heat source, the physics setting unit 310 activates the PCM sub-model, which receives the phase change temperature and latent heat of phase change as input parameters. The phase change temperature can be set from -30°C to 30°C, and the latent heat of phase change can be set from 50 kJ / kg to 400 kJ / kg.

[0051] The external temperature boundary condition setting unit 320 is used to set the temperature boundary conditions of the outer surface of the packaging box. This unit supports two working modes: constant temperature mode and dynamic temperature curve mode.

[0052] In constant temperature mode, the user directly inputs a constant ambient temperature value. The temperature setting range is -35℃ to 40℃. The external temperature boundary condition setting unit 320 applies this constant temperature value as a Dirichlet boundary condition to all outer surfaces of the packaging box, that is, directly sets the boundary node temperature to this constant value. This mode is suitable for scenarios where the external temperature is relatively stable, such as long-term frozen storage and constant temperature transportation.

[0053] In dynamic temperature profile mode, the external temperature boundary condition setting unit 320 allows users to define the external temperature profile that changes over time in two ways. The first method is table upload. Users upload a data file in CSV or TXT format, containing two columns: the first column shows the time data in seconds, and the second column shows the corresponding temperature data in degrees Celsius. The external temperature boundary condition setting unit 320 automatically reads this file and fits it into a continuous temperature curve using an interpolation algorithm. The second method is interface rendering. Users directly click to add time-temperature data points in the graphical interface. The external temperature boundary condition setting unit 320 automatically generates a continuous temperature curve using linear interpolation or spline interpolation algorithms. It is recommended that the temperature values ​​for the dynamic temperature curve be between -40℃ and 50℃ to cover extreme temperature conditions.

[0054] The external temperature boundary condition setting unit 320 sets the user-defined external temperature curve. The time-dependent temperature boundary condition is applied to the outer surface of the packaging box, and the boundary application algorithm is expressed as follows:

[0055]

[0056] in, For the outer surface of the box at time The boundary temperature, For user-defined external temperature functions, For interpolation functions, This provides a set of time-temperature data pairs input by the user. The dynamic temperature profile mode accurately simulates real-world dynamic environmental scenarios such as the door-opening effect, diurnal temperature variations, and inter-climate zone transportation.

[0057] The mechanical field and transportation mode setting unit 330 is used to set the mechanical loads that the packaging structure will experience during transportation. This unit includes a solid mechanics module enable control and a transportation mode selection control. When the user enables the solid mechanics module, the system will incorporate the mechanical response analysis of the packaging structure into the simulation calculation.

[0058] like Figure 9 As shown, the transportation mode selection control offers four options: sea freight, land freight, air freight, and custom. Each transportation mode has predefined typical vibration parameters, as follows: Sea freight mode corresponds to low-frequency swaying and vibration, with a frequency range of 0.1Hz to 5Hz and an acceleration range of 0.1g to 0.5g; Land freight mode corresponds to medium-frequency random vibration, with a frequency range of 5Hz to 100Hz and an acceleration range of 0.5g to 1.5g; Air freight mode corresponds to high-frequency vibration and impact, with a frequency range of 10Hz to 500Hz and an acceleration range of 1.0g to 3.0g.

[0059] like Figure 10 As shown, when the user selects the custom mode, the mechanical field and transportation mode setting unit 330 supports the user to upload a custom vibration curve data file, which is in CSV or TXT format and contains time-acceleration data pairs; the user can also manually input the vibration frequency range and acceleration amplitude through the interface.

[0060] The mechanical field and transportation mode setting unit 330 applies vibration loads to the bottom of the packaging box in the form of basic excitation to simulate the vibration generated by the transportation vehicle. Its basic acceleration application algorithm is expressed as follows:

[0061]

[0062] in, For the bottom of the box at any time The basic acceleration, This provides vibration data corresponding to the selected transportation mode or user-defined vibration curve data. This is the interpolation function.

[0063] The mechanical field and transportation mode setting unit 330 automatically activates the thermal-stress coupling multiphysics interface to couple the mechanical field with the temperature field for calculation, so as to analyze the impact of structural deformation and stress distribution caused by vibration on the heat transfer process.

[0064] The boundary conditions and physics field setting module 300 also supports setting other boundary conditions and initial conditions. The initial temperature setting is used to set the initial temperature of the product and air inside the packaging box, with a setting range of -35℃ to 40℃. The heat flux boundary condition can be selectively applied to specific surfaces to simulate localized heating or cooling scenarios. The convective heat transfer coefficient is used to set the convective heat transfer conditions of the air outside the box. When specific wind speed data is unavailable, the user can customize the convective heat transfer coefficient, with a setting range of 5 W·m⁻²·K⁻¹ to 50 W·m⁻²·K⁻¹.

[0065] The solver module 400 is used to call the finite element solver to perform multiphysics transient simulation calculations. This module receives the geometric model generated by the geometric modeling module 100, the computational mesh generated by the mesh generation module 200, and the physical field model and boundary conditions set by the boundary conditions and physical field setting module 300, and performs coupled transient calculations including temperature and mechanical fields. The solver module 400 calculates the temperature variation over time at various spatial locations inside the packaging under user-defined dynamic external temperature curves and transportation vibration conditions, as well as the stress distribution and deformation response of the packaging structure.

[0066] The results visualization and early warning module 500 is used to visualize and assess the calculation results output by the solution calculation module 400. For example... Figure 6As shown, this module displays a transient temperature field cloud map, demonstrating the temperature distribution inside the packaging at a specific moment. The module also displays a mesh generation diagram for users to check the mesh quality.

[0067] like Figure 7 As shown, the results visualization and early warning module 500 outputs a temperature change curve at a key point, which is typically selected as the product's location. This curve overlays the product temperature curve, the user-defined ambient temperature change curve, and the user-defined upper and lower limits of the safe temperature zone. The results visualization and early warning module 500 receives the user-defined safe temperature range for the product, which includes an upper and lower temperature limit, defined by the user based on the product's characteristics.

[0068] The results visualization and early warning module 500 automatically determines whether the product temperature exceeds the safe temperature range, calculates the duration for which the product temperature remains within the safe range as the safe duration, and marks the time point when the overheating event occurs on the temperature curve. When the product temperature exceeds the upper limit of the safe temperature range, the system issues an overheating risk warning; when the product temperature falls below the lower limit of the safe temperature range, the system issues an overcooling risk warning.

[0069] The results visualization and early warning module 500 also outputs a stress distribution cloud map, showing the stress distribution of the packaging structure under transportation vibration loads, and outputs the maximum stress value caused by vibration. Users can compare this maximum stress value with the yield strength of the packaging material to assess the integrity and safety of the packaging structure during transportation.

[0070] like Figure 8 As shown, this system also includes a parameter validation function. When the parameters entered by the user exceed the reasonable range, the system automatically provides an error message to guide the user to correct the input parameters.

[0071] Example 2

[0072] This embodiment provides a method for predicting the safety of the entire cold chain logistics process. This method is based on the system described in Embodiment 1, such as... Figure 2 As shown, it includes the following steps:

[0073] S1. Parameter input steps: Users input packaging parameters, material parameters, temperature parameters, and safety parameters through the system interface.

[0074] S1.1 Packaging Parameter Input: The user inputs the packaging box size parameters, including the packaging box length. Packaging box width Packaging box height And the thickness of the packaging box walls; the user inputs the thickness of the insulation material. The user inputs the dimensions of the cold or heat source, including the length of the cold source. Cold source width and the height of the cold source .

[0075] S1.2 Material Parameter Input: The user inputs the thermal conductivity of the insulation material, which ranges from 0.02 W·m⁻¹·K⁻¹ to 0.2 W·m⁻¹·K⁻¹; the user inputs the phase change parameters of the cold or heat source, including the phase change temperature and the latent heat of phase change. The phase change temperature ranges from -30℃ to 30℃, and the latent heat of phase change ranges from 50 kJ / kg to 400 kJ / kg.

[0076] S1.3 Temperature Parameter Input: The user sets the initial product temperature, ranging from -35℃ to 40℃; the user sets the external temperature boundary conditions, choosing between a constant temperature mode or a dynamic temperature curve mode. In constant temperature mode, the user inputs a constant external temperature value, ranging from -35℃ to 40℃. In dynamic temperature curve mode, the user defines a curve showing the change of external temperature over time by uploading a data file or drawing it through the interface. The recommended temperature range for the curve is between -40℃ and 50℃.

[0077] S1.4 Safety Parameter Input: The user sets the product's safe temperature range, including the upper and lower safe temperature limits. This safe temperature range is determined according to the product type. For example, the safe temperature range for vaccines is usually 2℃ to 8℃, for frozen foods it is usually -18℃ to -15℃, and for fresh products it is usually 0℃ to 4℃.

[0078] S2. Geometric model generation steps: When the user clicks the "Show Geometry" button, the system automatically generates a three-dimensional geometric model containing the packaging box, insulation layer, and cold or heat source based on the packaging parameters input in step S1.

[0079] S3. Boundary Conditions and Physics Field Setting Steps: The user clicks the Boundary Conditions button, and the system executes physics field configuration and applies boundary conditions.

[0080] S3.1 Physics Field Configuration: The system configures the corresponding physics field model according to the user's selection. The system configures a solid heat transfer model to simulate the heat conduction process in the packaging box, insulation materials, and cold or hot sources. The system configures a fluid heat transfer model and a laminar flow model to simulate the convective heat transfer process of the air inside the box. The system configures a non-isothermal flow model to couple the temperature field with the fluid flow. When using phase change materials, the system enables the phase change material sub-model and loads the phase change temperature and latent heat parameters input by the user.

[0081] S3.2 Application of External Temperature Boundary Conditions: In constant temperature mode, the system applies the user-input constant temperature value as a Dirichlet boundary condition to all outer surfaces of the packaging box. In dynamic temperature profile mode, the system loads or generates a user-defined external temperature profile. This temperature is applied as a time-dependent temperature boundary condition to the outer surface of the packaging box. The boundary temperature calculation formula is as follows: .

[0082] S3.3 Mechanical Field and Transportation Mode Settings: When the user enables the Solid Mechanics module, the system performs mechanical field configuration. The user selects sea, land, air, or a custom mode from the transportation mode options. The system loads the corresponding vibration parameters or the user-defined vibration curve according to the user's selection. The system applies the vibration load to the bottom of the packaging box as a basic excitation, and the basic acceleration calculation formula is as follows: The system uses a thermal-stress coupling interface to establish a coupling relationship between the temperature field and the mechanical field.

[0083] S4. Meshing Steps: The user clicks the meshing button, and the system meshes the 3D geometric model. The system uses tetrahedral meshes for the packaging box and the air area inside the box, and swept meshes for the cold or heat source areas. The user can adjust the mesh size parameters as needed.

[0084] S5. Calculation Steps: When the user clicks the Calculate button, the system calls the finite element solver to perform multiphysics transient simulation calculations. Based on the set physical field model and boundary conditions, the solver calculates the temperature change over time at various points inside the packaging under dynamic external temperature curves and transportation vibration conditions, while also calculating the stress distribution and deformation response of the packaging structure.

[0085] S6. Results Output and Early Warning Steps: After the calculation is completed, the system automatically outputs the simulation results and performs a safety assessment.

[0086] S6.1 Temperature Field Visualization: The system displays a transient temperature field cloud map, showing the temperature distribution inside the packaging at various times. The system outputs temperature change curves at key points, which overlay the product temperature curve, the external temperature change curve, and the upper and lower limits of the user-defined safe temperature zone.

[0087] S6.2 Safe Duration Calculation and Early Warning: The system automatically traverses the product temperature change curve to determine whether the product temperature at each moment is within the user-defined safe temperature range. The system calculates the duration for which the product temperature remains within the safe range as the safe duration. When the product temperature exceeds the safe temperature range, the system marks the over-temperature time point on the curve and issues an overheat risk warning or an overcooling risk warning based on the type of over-temperature.

[0088] S6.3 Mechanical Analysis Result Output: When the solid mechanics module is enabled, the system displays a stress distribution cloud map and outputs the maximum stress value caused by vibration, allowing users to assess the safety of the packaging structure during transportation.

[0089] Example 3

[0090] This embodiment uses the scenario of cross-regional air transport of vaccines as an example to illustrate the specific application of the system and method of the present invention.

[0091] In the parameter input step, the user inputs the following parameters: the packaging box dimensions are 300mm in length, 300mm in width, and 300mm in height; the insulation material is 30mm thick polyurethane foam with a thermal conductivity of 0.03W·m⁻¹·K⁻¹; the cold source is a phase change material board with a phase change temperature of 5℃ and a latent heat of phase change of 250kJ / kg; the initial product temperature is 5℃; and the safe temperature range is 2℃ to 8℃.

[0092] In the setting of external temperature boundary conditions, the user selects the dynamic temperature curve mode and defines the temperature curve for simulating 6 hours of air transport by drawing on the interface: from 0 to 2 hours, the external temperature is maintained at 15℃, simulating a temperate warehouse environment; from 2 to 4 hours, the external temperature rises linearly from 15℃ to 32℃, simulating temperature changes during transport; from 4 to 6 hours, the external temperature is maintained at 32℃, simulating a tropical destination environment.

[0093] In the mechanical field settings, the user enables the solid mechanics module and selects the air transport mode. The system automatically applies the default vibration parameters for air transport, with a vibration frequency range of 10Hz to 500Hz and an acceleration range of 1.0g to 3.0g.

[0094] After the system completes geometric modeling, mesh generation, and boundary condition settings, the user initiates the solution calculation. Upon completion, the system outputs temperature change curves and stress distribution contour maps. The results show that the product temperature gradually increases during transportation, remaining within a safe range until the end of the journey, but approaching the 8°C upper limit in the last hour. The system calculates a safe duration of 6 hours and simultaneously issues a risk warning indicating insufficient safety margin. The stress contour map shows that the maximum stress on the packaging structure under air transport vibration conditions is 0.8 MPa, lower than the yield strength of the polyurethane foam material, indicating good structural integrity. These simulation results indicate that while this packaging scheme can complete the transportation task, the safety margin is insufficient, and it is recommended to optimize the packaging design or increase the configuration of the cold source.

[0095] Example 4

[0096] This embodiment uses the urban delivery scenario of fresh produce as an example to illustrate the application of the system and method of the present invention in a complex dynamic temperature environment.

[0097] In the parameter input step, the user inputs the following parameters: the packaging box dimensions are 400mm in length, 400mm in width, and 400mm in height; the insulation material is 40mm thick EPS foam with a thermal conductivity of 0.04W·m⁻¹·K⁻¹; the cold source is a cold storage gel pack with a phase change temperature of 0℃ and a latent heat of phase change of 180kJ / kg; the initial product temperature is 4℃; and the safe temperature range is 0℃ to 4℃.

[0098] In the setting of external temperature boundary conditions, the user selects the dynamic temperature curve mode and defines a complex temperature curve to simulate 24-hour delivery: from 0 to 8 hours, the external temperature is maintained at 5°C to simulate the nighttime environment; from 8 to 16 hours, the external temperature rises linearly from 5°C to 25°C to simulate the daytime temperature rise; at the 10th and 14th hours, a 30°C temperature shock is introduced for 10 minutes to simulate the door opening and unloading operations during the delivery process; from 16 to 24 hours, the external temperature gradually drops from 25°C to 10°C to simulate the temperature change from evening to night.

[0099] In the mechanical field settings, the user enables the solid mechanics module and selects the land transport mode. The system automatically applies the default vibration parameters for land transport, with a vibration frequency range of 5Hz to 100Hz and an acceleration range of 0.5g to 1.5g.

[0100] After the calculations were completed, the system output temperature change curve showed that the product temperature fluctuated momentarily during the two door-opening impacts, but quickly returned to the safe range after the door was closed. Despite experiencing diurnal temperature variations, multiple door-opening impacts, and continuous vibrations during land transportation, the product temperature did not exceed the safe range of 0℃ to 4℃ throughout the entire process. The system calculated a safe duration of 24 hours. Stress analysis results showed that the maximum stress on the packaging structure under land transportation vibration conditions was 0.5MPa, indicating that the structure is safe and reliable. These simulation results confirm that the packaging solution is safe and reliable for this 24-hour urban delivery task.

[0101] Example 5

[0102] This embodiment uses the scenario of long-distance land transportation of frozen food as an example to illustrate the application of the system and method of the present invention in a long-term complex dynamic environment and its ability to accurately predict the risk of overheating.

[0103] In the parameter input step, the user inputs the following parameters: the packaging box dimensions are 400mm in length, 400mm in width, and 400mm in height; the insulation material is 40mm thick EPS foam with a thermal conductivity of 0.04W·m⁻¹·K⁻¹; the cold source is a cold storage gel pack with a phase change temperature of 0℃ and a latent heat of phase change of 180kJ / kg; the initial product temperature is -18℃; and the safe temperature range is -18℃ to -15℃.

[0104] In the setting of external temperature boundary conditions, users can select the dynamic temperature curve mode and define a complex 72-hour transportation temperature curve by uploading a pre-measured temperature data file. This curve reflects a combination of factors, including diurnal temperature variations in different latitude regions experienced during transportation, temperature fluctuations when passing through tunnels, and temperature changes during rest stops at service areas.

[0105] In the mechanical field settings, users enable the solid mechanics module and select the custom mode, uploading vibration curve data collected based on actual road conditions to more accurately simulate the real vibration environment during long-distance land transportation.

[0106] After the calculations were completed, the system output temperature change curve clearly showed the trend of product temperature change over transportation time. The results showed that during the first 60 hours of transportation, despite continuous fluctuations in the external temperature, the product temperature remained within the safe range of -18℃ to -15℃. However, after the 60th hour of transportation, due to the persistently high external temperature and the cumulative effect of the localized compression of the insulation material caused by prolonged vibration, resulting in a slight increase in its equivalent thermal conductivity, the product temperature began to slowly rise and exceeded the safe upper limit of -15℃. The system automatically marked this over-temperature point and calculated the precise safe duration as 60 hours.

[0107] Stress analysis results show that prolonged vibration during land transportation causes compressive deformation in localized areas of the insulation material. Although this deformation does not reach the point of material failure, it increases the equivalent thermal conductivity in that area, thereby accelerating the subsequent temperature rise. This simulation result reveals the long-term impact mechanism of vibration on insulation performance, providing crucial technical support for logistics timeliness management and packaging structure optimization. Based on these simulation results, logistics companies can control transportation timeliness to within 60 hours, use insulation materials with better compressive strength, or increase cold source configuration to extend the safe operating time.

[0108] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A full-process cold chain logistics safety prediction system, characterized in that, include: The geometric modeling module (100) is used to automatically generate a three-dimensional geometric model containing the packaging box, insulation layer and cold or heat source based on the packaging parameters input by the user. The mesh generation module (200) is used to mesh the three-dimensional geometric model. The boundary condition and physics field setting module (300) is used to set the physics field model required for simulation calculation and apply external temperature boundary conditions and mechanical load boundary conditions; the external temperature boundary conditions support input of dynamic temperature curves that change over time; the mechanical load boundary conditions support selection of transportation methods and application of corresponding vibration parameters. The solver module (400) is used to call the solver to perform multiphysics transient simulation based on the three-dimensional geometric model and boundary conditions, and to calculate the temperature field changes and structural response inside the packaging under dynamic external temperature and transportation vibration conditions. The results visualization and early warning module (500) is used to output temperature change curves and stress distribution cloud maps, and to calculate the safe duration based on the set product safe temperature range.

2. The end-to-end cold chain logistics safety prediction system according to claim 1, characterized in that, The packaging parameters received by the geometric modeling module (100) include: the length, width, height and wall thickness of the packaging box, the thickness of the insulation material, and the length, width and height of the cold source or heat source; the geometric modeling module (100) constructs and assembles the solid models of each component according to the packaging parameters.

3. The end-to-end cold chain logistics safety prediction system according to claim 1, characterized in that, The mesh division module (200) is configured to divide the packaging box and the air area inside the box using a tetrahedral mesh, and to divide the cold source or heat source area using a swept mesh, and supports users to adjust the mesh size.

4. The end-to-end cold chain logistics safety prediction system according to claim 1, characterized in that, The physical field model configured by the boundary conditions and physical field setting module (300) includes: a solid heat transfer model for simulating heat conduction of the packaging box and cold source, a fluid heat transfer and laminar flow model for simulating air convection inside the box, and a non-isothermal flow model for simulating temperature and fluid coupling; when the cold source is a phase change material, it also includes a phase change material model and receives phase change temperature and latent heat parameters.

5. The end-to-end cold chain logistics safety prediction system according to claim 1, characterized in that, When applying external temperature boundary conditions, the boundary condition and physical field setting module (300) adopts a dynamic temperature curve mode: by reading the time-temperature data file uploaded by the user or the time-temperature points drawn by the user on the interface, it generates a continuous external temperature function. And apply it to the outer surface of the packaging box using the following formula: ； in, The outer surface temperature of the enclosure. For time.

6. The end-to-end cold chain logistics safety prediction system according to claim 1, characterized in that, The boundary condition and physics field setting module (300) provides four transportation options—sea transport, land transport, air transport, and custom transport—when applying mechanical load boundary conditions. The system determines the vibration data based on the user-selected transportation method and applies the base acceleration to the bottom of the packaging box using the following formula: ； in, For the basic acceleration of the bottom of the box, For vibration data corresponding to the transportation mode, The interpolation function is used; the solution calculation module (400) uses the thermal-stress coupling interface to calculate the effect of vibration on the temperature field.

7. The end-to-end cold chain logistics safety prediction system according to claim 6, characterized in that, The vibration parameters corresponding to the transportation method are preset as follows: Ocean freight: Frequency 0.1-5Hz, acceleration 0.1-0.5g; Land transport: frequency 5-100Hz, acceleration 0.5-1.5g; Air transport: frequency 10-500Hz, acceleration 1.0-3.0g.

8. The end-to-end cold chain logistics safety prediction system according to claim 1, characterized in that, The result visualization and early warning module (500) is configured as follows: Generate key point temperature change curves, and overlay the product temperature curve, the external temperature change curve, and the user-defined upper and lower limits of the safe temperature zone onto the curve graph. The system automatically determines whether the product temperature exceeds the safe temperature range and calculates the duration for which the product temperature remains within the safe range as the safe duration.

9. The end-to-end cold chain logistics safety prediction system according to claim 8, characterized in that, The result visualization and early warning module (500) is also used for: An overheating risk warning is issued when the product temperature exceeds the upper limit of the safe temperature range, and an overcooling risk warning is issued when the product temperature is below the lower limit of the safe temperature range. Output the maximum stress value caused by vibration to assess the safety of the packaging structure.

10. A method for predicting the safety of the entire cold chain logistics process, implemented based on the system described in any one of claims 1-9, characterized in that, Includes the following steps: S1. Input packaging size parameters, thermal conductivity of insulation material, cold source phase change parameters, initial product temperature and safe temperature range; S2. Generate a 3D geometric model of the packaging and perform mesh generation; S3. Set up a physical field model and apply external temperature boundary conditions and mechanical load boundary conditions; wherein, the external temperature boundary condition is a dynamic temperature curve that changes with time, and the mechanical load boundary condition automatically matches vibration parameters according to the selected transportation method. S4. Perform multiphysics transient simulation calculations to solve the coupled response of the temperature field and the mechanical field; S5 outputs a temperature cloud map and a product temperature change curve superimposed with the external temperature curve, calculates the safe duration, and provides early warning of over-temperature risks.

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