Method and device for predicting state of material during preservation process, and vacuum cooling device

Abstract

This invention provides a method for predicting the state of materials during preservation, comprising the following steps: establishing a geometric model of the material based on its shape; determining the material parameters of the geometric model based on the preservation process; constructing a physical field based on the geometric model and material parameters; constructing governing equations for the physical field, wherein heat transfer governing equations for the preservation process are constructed through heat transfer within the material and heat transfer between the material and the medium, and mass transfer governing equations for the preservation process are constructed through mass diffusion of the material in the environment; setting initial conditions, boundary conditions, and physical field parameters for the physical field; meshing the geometric model; solving the governing equations and post-processing the solution results. This invention also provides a device for predicting the state of materials during preservation and a vacuum cooling device.

Description

Technical Field

[0001] This invention relates to the field of food processing, and in particular to a method and apparatus for predicting the state of materials during preservation. Background Technology

[0002] Vacuum cooling is a highly efficient and rapid method for preserving materials. The principle of vacuum cooling is to utilize the latent heat generated by the phase change of water to achieve cooling. Under constant temperature conditions, reducing pressure causes water to change from a liquid to a gaseous state. The latent heat absorbed by the evaporation of water in the material mainly comes from the material's sensible heat, and water has a higher specific heat than most other liquids, thus achieving rapid cooling of the material.

[0003] However, because the vacuum chamber cooling process requires strict sealing, the food state of the cooled material is difficult to monitor directly, which leads to inaccurate control of the vacuum cooling process and a decline in material quality. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention discloses a method for predicting the state of materials during preservation, comprising the following steps:

[0005] Establish a geometric model of the material based on its shape;

[0006] The material parameters of the geometric model are determined based on the preservation process;

[0007] A physical field is constructed based on the geometric model and the material parameters;

[0008] A control equation is constructed for the physical field, wherein the heat transfer control equation for the preservation process is constructed through the heat transfer inside the material and the heat transfer between the material and the medium, and the mass transfer control equation for the preservation process is constructed through the mass diffusion of the material in the environment.

[0009] Set initial conditions, boundary conditions, and physical field parameters for the physical field;

[0010] The geometric model is meshed;

[0011] Solve the governing equations and perform post-processing on the solution results.

[0012] In one embodiment of the aforementioned method of the present invention, the step of constructing the heat transfer control equation for the preservation process through heat transfer within the material and heat transfer between the material and the medium further includes:

[0013] The energy conservation principle of heat transfer in the medium is used to construct the control equation for heat transfer within the material.

[0014] The heat transfer control equation between the material and the environment is constructed by considering the heat transfer at the material boundary in the medium.

[0015] In one embodiment of the method described above, the step of constructing the mass transfer control equation during the preservation process based on the material diffusion in the environment further includes:

[0016] The mass transfer control equation of the material in the environment is constructed based on the law of material transfer from high concentration area to low concentration area.

[0017] In one embodiment of the aforementioned method of the present invention, the step of constructing the governing equation for heat transfer within the material based on the energy conservation of heat transfer in the medium further includes:

[0018] The governing equations for heat transfer within the material are constructed using Fourier's heat transfer law:

[0019] Where ρ represents density, in kg / m³ 3 C P This represents the constant-pressure heat capacity, in J / (kg / K), where J is the joule, K is the Kelvin temperature, T represents the material temperature in K, and t represents time in seconds. Let q denote the vector differential operator, and q denote the net heat flux density vector, in units of W / m³. 2 W represents watts, Q represents the internal heat source, W / m 3 ;

[0020] in, This indicates the rate of water evaporation, expressed in kg / (m³). 3 *s), ΔH vap The latent heat of vaporization of water is expressed in J / kg.

[0021] Where, k vap ρ represents the evaporation rate constant, in units of 1 / s. L This represents the density of the liquid phase, in kg / m³. 3 p * This represents saturated vapor pressure, in Pa, p. G This indicates the pressure inside the vacuum chamber, in Pa; and,

[0022] p * =10 A-B / (C+T) Where A, B, and C are constants, and T represents the material temperature in K.

[0023] In one embodiment of the aforementioned method of the present invention, the step of constructing the heat transfer control equation between the material and the environment based on the heat transfer situation at the material boundary in the medium further includes:

[0024] The heat transfer control equation between the material and the environment is constructed using Newton's law of cooling:

[0025] q=h(T ext -T), where q represents the net heat flux density vector at the material boundary, in W / m³. 2 h represents the heat transfer coefficient at the boundary, in W / (m²). 2 *K), T ext The external ambient temperature is represented by K, and T represents the material temperature, also in K.

[0026] In one embodiment of the method described above, the step of constructing the mass transfer control equation of the material in the environment based on the law of material transfer from a high concentration region to a low concentration region further includes:

[0027] The mass transfer control equation of the material in the environment is constructed using Fick's second diffusion law:

[0028] Where, θ L D represents the volume fraction of the liquid phase. L This represents the apparent liquid diffusion coefficient, expressed in m² / s.

[0029] Where α represents a proportionality constant. This indicates the residual saturation.

[0030] In one embodiment of the method described above, the steps of solving the governing equations and post-processing the solution results further include:

[0031] Set the solver to transient;

[0032] Set the output timing step according to the preservation process requirements;

[0033] The plotting group is set up to plot the data results based on the solution results of the control equations.

[0034] The present invention also provides a material state prediction device during the preservation process, for implementing the aforementioned method, comprising:

[0035] The geometric model building module establishes a geometric model of the material based on its shape.

[0036] The material parameter module determines the material parameters of the geometric model based on the preservation process.

[0037] The physics field construction module constructs a physics field based on the geometric model and the material parameters. This physics field construction module further includes:

[0038] The control equation construction module constructs control equations for the physical field, including heat transfer control equations for the preservation process based on heat transfer within the material and heat transfer between the material and the medium, and mass transfer control equations for the preservation process based on the material diffusion in the environment.

[0039] The physics field setting module sets the initial conditions, boundary conditions, and physics field parameters for the physics field.

[0040] The mesh generation module performs mesh generation on the geometric model;

[0041] The solution and post-processing module solves the governing equations and performs post-processing on the solution results.

[0042] The present invention also provides a vacuum cooling device, comprising:

[0043] A vacuum chamber is used to provide a vacuum environment for materials.

[0044] A vacuum unit includes a vacuum pump and a vacuum valve connected to the vacuum pump, the vacuum pump and the vacuum valve being used to provide a vacuum environment for the vacuum chamber;

[0045] A cooling unit, connected to the vacuum chamber, is used to provide cooling water;

[0046] The control unit is connected to the vacuum pump and the cooling unit;

[0047] The aforementioned material state prediction device during the preservation process is connected to the control unit.

[0048] The present invention also provides a storage medium for storing a computer control program for performing the steps of any of the foregoing methods.

[0049] This invention proposes a method, apparatus, and vacuum cooling device for predicting the state of materials during preservation. It constructs a geometric model of the material and its material parameters, and then builds a physical field based on these parameters. Control equations for this physical field are then established, including heat transfer control equations based on internal heat transfer within the material and heat transfer between the material and the medium, and mass transfer control equations based on the material's diffusion within the environment. Solving these control equations yields simulation results of the material's state during preservation. Based on these simulation results, the preservation process can be precisely controlled, better maintaining the quality of the material. Attached Figure Description

[0050] Figure 1 This is a schematic diagram of the material state prediction method during the preservation process in an embodiment of the present invention;

[0051] Figure 2 This is a two-dimensional axisymmetric model diagram of the material in an embodiment of the present invention;

[0052] Figure 3 This is a mesh partitioning diagram of the material in an embodiment of the present invention;

[0053] Figure 4 This is a temperature distribution diagram of the materials in an embodiment of the present invention;

[0054] Figure 5 This is a moisture distribution diagram of the materials in an embodiment of the present invention;

[0055] Figure 6 These are the measured and simulated temperature change curves of the material during vacuum cooling in the embodiments of the present invention;

[0056] Figure 7 The figures shown are the measured moisture content and simulated temperature change curves of the material during vacuum cooling in this embodiment of the invention.

[0057] Figure 8 This is a block diagram of the material state prediction device during the preservation process in an embodiment of the present invention;

[0058] Figure 9 This is a block diagram of the vacuum cooling device in an embodiment of the present invention.

[0059] In the attached figures, the following labels are used:

[0060] 1: Two-dimensional axisymmetric model

[0061] 21: Grid

[0062] 10: Material State Prediction Device During Preservation

[0063] 11: Geometric Model Building Module

[0064] 12: Material Parameter Module

[0065] 13: Physics Field Construction Module

[0066] 14: Governing Equations Construction Module

[0067] 15: Physics Field Setting Module

[0068] 16: Mesh Generation Module

[0069] 17: Solving and Post-processing Module

[0070] 100: Vacuum cooling device

[0071] 110: Vacuum cavity

[0072] 120: Vacuum Unit

[0073] 121: Vacuum pump

[0074] 122: Vacuum valve

[0075] 130: Cooling unit

[0076] 140: Control Unit

[0077] S1-S7: Steps Detailed Implementation

[0078] The technical solution of the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments, so as to further understand the purpose, solution and beneficial technical effects of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0079] It should be noted that in this specification, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0080] Certain terms are used in this specification and the appended claims to refer to specific components or parts. Those skilled in the art will understand that users or manufacturers may use different names or terms to refer to the same component or part. This specification and the appended claims do not distinguish components or parts by differences in name, but rather by differences in function.

[0081] In this invention, the terms "upper," "lower," "left," "right," "front," "rear," "top," "bottom," "inner," "outer," "middle," "vertical," "horizontal," "lateral," and "longitudinal" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are primarily for the purpose of better describing the invention and its embodiments, and are not intended to limit the indicated devices, elements, or components to having a specific orientation, or to be constructed and operated in a specific orientation.

[0082] Furthermore, in addition to indicating direction or positional relationship, some of the aforementioned terms may also have other meanings. For example, the term "above" may also be used in certain situations to indicate a dependency or connection. Those skilled in the art can understand the specific meaning of these terms in this invention based on the specific circumstances.

[0083] Furthermore, the terms "installation," "setup," "equipped with," "connection," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral structure; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium, or an internal connection between two devices, components, or parts. Those skilled in the art can understand the specific meaning of these terms in this invention based on the specific circumstances.

[0084] Vacuum cooling: At normal atmospheric pressure (1 atmosphere), the boiling point of water is 100°C. As the pressure decreases, the boiling point of water also decreases. For example, at 0.01 atmospheres, the boiling point of water can drop to approximately 0°C. Vacuum cooling accelerates heat dissipation by lowering the ambient pressure, causing water to boil at a lower temperature. When water changes from a liquid to a gaseous state (evaporation), it absorbs a large amount of heat. This is because evaporation is an endothermic process that requires energy to overcome the intermolecular forces. In a vacuum environment, water molecules evaporate more easily from a liquid to a gaseous state, carrying away more heat and achieving rapid cooling. Because the evaporation rate in a vacuum is much higher than at normal atmospheric pressure, the temperature of food can be lowered quickly. This rapid cooling method effectively reduces the growth of microorganisms and chemical reactions in food, thereby extending its shelf life.

[0085] Vacuum cooling places two requirements on the material itself: the material should have a large specific surface area and porosity; and partial water loss should not cause serious quality problems. Currently, in the food industry, vacuum cooling is widely used for removing field heat from fruits and vegetables and for pre-cooling cooked meat products.

[0086] Because the vacuum chamber cooling process requires strict sealing, the state of the food material being cooled is difficult to monitor directly. This leads to inaccurate control of the vacuum cooling process and a decline in material quality. To solve this technical problem, such as... Figure 1 As shown, this invention discloses a method for predicting the state of materials during preservation, comprising the following steps:

[0087] Step S1: Establish a geometric model of the material based on its shape;

[0088] Step S2: Determine the material parameters of the geometric model based on the preservation process;

[0089] Step S3: Construct the physical field based on the geometric model and material parameters;

[0090] Step S4: Construct governing equations for the physical field, including heat transfer control equations for the preservation process based on heat transfer within the material and heat transfer between the material and the medium, and mass transfer control equations for the preservation process based on the diffusion of matter in the environment.

[0091] Step S5: Set the initial conditions, boundary conditions, and physical field parameters for the physical field;

[0092] Step S6: Mesh the geometric model;

[0093] Step S7: Solve the governing equations and post-process the solution results.

[0094] like Figure 2 As shown, in one embodiment, in step S1, a geometric model of the material is established based on parameters such as the length, width, and height of the material placed in the vacuum cavity. In one embodiment, the geometric model of the material can be established in COMSOL simulation software, or other modeling software can be used. It should be noted that the simulation software used in this invention is COMSOL, but other similar simulation software can also be used to implement the method of this invention, and it is not limited thereto. In one embodiment, the established geometric model of the material is an abstraction of the three-dimensional geometric model into a two-dimensional axisymmetric model 1.

[0095] In one embodiment, the material parameters of the geometric model determined in step S2 include density, constant-pressure heat capacity, and thermal conductivity. Since food materials are mostly porous media, their material properties need to be classified into solid, liquid, and gas phases based on their different phases. The parameters obtained through measurement and data inquiry are shown in Table 1. Table 1 lists the material property parameters of the materials used in the experiment. For other types of materials, their relevant property parameters need to be obtained through measurement and data inquiry.

[0096] Table 1 Material Properties Details

[0097]

[0098]

[0099] In one embodiment, the step of constructing the heat transfer control equation for the preservation process through heat transfer within the material and heat transfer between the material and the medium further includes:

[0100] The energy conservation principle of heat transfer in the medium is used to construct the control equation for heat transfer within the material.

[0101] By analyzing the heat transfer at the material's boundaries within the medium, a governing equation for heat transfer between the material and its environment is constructed. Using this method, the heat transfer of the material within the environment is analyzed, and governing equations are established to describe the dynamic heat transfer process at different time scales. This allows for the determination of temperature variations within the material and at its boundaries over time, thus predicting the temperature distribution and heat transfer at different points in time, demonstrating strong predictability.

[0102] In one embodiment, the step of constructing the mass transfer control equation during the preservation process based on the material diffusion in the environment further includes:

[0103] This method constructs mass transfer control equations for materials in the environment based on the laws governing the transfer of substances from high-concentration areas to low-concentration areas. It can describe the dynamic mass transfer process of materials at different time scales. By solving the mass transfer control equations, the concentration changes over time within and at the material's boundaries can be obtained, thus predicting the concentration distribution and mass transfer of materials at different time points, demonstrating strong predictability.

[0104] In one embodiment, the step of constructing the governing equation for heat transfer within the material based on the energy conservation principle of heat transfer in the medium further includes:

[0105] The governing equations for heat transfer within the material are constructed using Fourier's heat transfer law:

[0106] Where ρ represents density, in kg / m³ 3 C P This represents the constant-pressure heat capacity, in J / (kg / K), where J is the joule, K is the Kelvin temperature, T represents the material temperature in K, and t represents time in seconds. Let q denote the vector differential operator, and q denote the net heat flux density vector, in units of W / m³. 2 W represents watts, Q represents the internal heat source, W / m 3 ;

[0107] in, This indicates the rate of water evaporation, expressed in kg / (m³). 3 *s), ΔH vap The latent heat of vaporization of water is expressed in J / kg.

[0108] Where, k vap ρ represents the evaporation rate constant, in units of 1 / s. L This represents the density of the liquid phase, in kg / m³. 3 p * This represents saturated vapor pressure, in Pa, p. G This indicates the pressure inside the vacuum chamber, in Pa; and,

[0109] p * =10 A-B / (C+T) Where A, B, and C are constants, and T represents the material temperature in K.

[0110] The Fourier heat transfer law is used to construct the control equation for heat transfer inside materials. It can also describe and predict complex heat transfer processes, such as heat transfer in multi-layer media and phase change heat transfer. In addition, the Fourier law can accurately calculate the heat transfer rate by measuring a small number of parameters.

[0111] In one embodiment, the step of constructing the governing equation for heat transfer between the material and the environment based on the heat transfer at the material boundary in the medium further includes:

[0112] The heat transfer control equation between materials and the environment is constructed using Newton's law of cooling:

[0113] q=h(T ext -T), where q represents the net heat flux density vector at the material boundary, in W / m³. 2 h represents the heat transfer coefficient at the boundary, in W / (m²). 2 *K), T ext The external ambient temperature is represented by K, and T represents the material temperature, also in K.

[0114] The heat transfer control equation between materials and the environment is constructed using Newton's law of cooling. It is easy to apply by measuring a small number of parameters and can quickly calculate and predict the heat transfer rate between materials and the environment.

[0115] In one embodiment, the step of constructing the mass transfer control equation of the material in the environment based on the law of material transfer from a high concentration area to a low concentration area further includes:

[0116] The mass transfer control equations for materials in the environment are constructed using Fick's second diffusion law:

[0117] Where, θ L D represents the volume fraction of the liquid phase. L This represents the apparent liquid diffusion coefficient, expressed in m² / s.

[0118] Where α represents a proportionality constant. This indicates the residual saturation.

[0119] The mass transfer control equation of materials in the environment is constructed using Fick's second diffusion law. Fick's second law is derived from Fick's first law and combined with the mass conservation equation. It can accurately describe the transfer and accumulation of matter during the diffusion process. Fick's second law can more accurately describe the concentration change during the diffusion process. This accuracy is very important for predicting and controlling the mass transfer process.

[0120] In one embodiment, setting the initial conditions in step S5 includes setting the initial temperature T of the material to 353.15 K and the moisture content θ to... L The water content is 0.77 g / g (water content is usually expressed as mass fraction, but here it refers to the volume fraction of the liquid phase), and the boundary conditions include the ambient temperature T. ext The surface heat transfer coefficient h is 25 W / (m²*K), and the evaporation rate m is 273.15 K. LG It is 2.7*10-7 kg / (m3*s).

[0121] like Figure 3 As shown, in one embodiment, the mesh generation in step S5 uses a physics-controlled mesh with an extremely fine size. The number of meshes 21 is 11280. In actual operation, the model can be automatically meshed in Comsol, with finer meshes 21 at sharp corners and curves, and coarser meshes 21 at flat areas. Since the food material has a small volume, and the overall computational load is small after abstracting the material geometry into a two-dimensional axisymmetric model 1, the element size can be "extremely fine" without causing excessive computational pressure. In practice, the mesh size can be set according to the actual situation of the two-dimensional axisymmetric model 1 of the material.

[0122] In one embodiment, the step of solving the governing equations and post-processing the solution results further includes:

[0123] Set the solver to transient;

[0124] Set the output timing step according to the preservation process requirements;

[0125] The plotting group is set up to draw the data results based on the solution of the governing equations.

[0126] In one embodiment, when setting the output time step, if the total process time is 90 minutes and it is necessary to know the specific temperature and moisture content every 10 minutes, then the time unit is set to min, and the output time step is range(0,10,90). Numerical simulation can obtain the distribution of temperature and moisture at various locations of the material at different times. The data results can be displayed by setting up a plotting group, such as... Figure 4 and Figure 5 As shown. Temperature and moisture content data of the material were collected during the vacuum cooling process to verify the numerical simulation results, such as... Figure 6 and Figure 7As shown, based on the simulation results and the comparison with the simulation results, this model can be used to simulate and predict similar processes in the future. Only the geometric model, materials and process parameters need to be replaced, which can save time and resources.

[0127] It should be noted that the material state prediction method described above in this invention can be applied not only to vacuum cooling preservation processes, but also to preservation processes in other non-vacuum environments.

[0128] like Figure 8 As shown, the present invention also provides a material state prediction device 10 for the preservation process, used to implement the aforementioned method, including:

[0129] Geometric model building module 11, which builds a geometric model of the material based on its shape;

[0130] Material Parameter Module 12 determines the material parameters of the geometric model based on the preservation process;

[0131] Physics field construction module 13 constructs the physics field based on the geometric model and material parameters. Physics field construction module 13 further includes:

[0132] The control equation construction module 14 constructs control equations for the physical field. Among them, the heat transfer control equation for the preservation process is constructed through the heat transfer inside the material and the heat transfer between the material and the medium, and the mass transfer control equation for the preservation process is constructed through the material diffusion in the environment.

[0133] Physics field setting module 15 sets the initial conditions, boundary conditions, and physics field parameters for the physics field;

[0134] Mesh generation module 16 performs mesh generation on the geometric model;

[0135] The solution and post-processing module 17 solves the governing equations and performs post-processing on the solution results.

[0136] In one embodiment, the physical field, its governing equations, initial conditions, boundary conditions, and parameters can be constructed in the COMSOL simulation software. It should be noted that the simulation software used in this invention is COMSOL, but other similar simulation software can also be used to implement the method of this invention, and it is not limited thereto.

[0137] like Figure 9 As shown, the present invention also provides a vacuum cooling device 100, comprising:

[0138] Vacuum chamber 110 is used to provide a vacuum environment for materials;

[0139] Vacuum unit 120 includes vacuum pump 121 and vacuum valve 122 connected to vacuum pump 121. Vacuum pump 121 and vacuum valve 122 are used to provide a vacuum environment for vacuum chamber 110.

[0140] A cooling unit 130, connected to the vacuum chamber 110, is used to provide cooling water;

[0141] Control unit 140 is connected to vacuum pump 121 and cooling unit 140.

[0142] The aforementioned material state prediction device 10 during the preservation process is connected to the control unit 140.

[0143] The present invention also provides a storage medium for storing a computer control program, the computer control program being used to perform the steps of any of the foregoing methods.

[0144] It should be understood that the storage medium in the embodiments of the present invention can be volatile memory or non-volatile memory, or may include both volatile and non-volatile memory. The non-volatile memory can be read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), or flash memory. The volatile memory can be random access memory (RAM), which is used as an external cache. By way of example, but not limitation, many forms of random access memory (RAM) are available, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate synchronous DRAM (DDR SDRAM), enhanced synchronous DRAM (ESDRAM), synchronous linked DRAM (SLDRAM), and direct rambus RAM (DR RAM).

[0145] This invention proposes a method, apparatus, and vacuum cooling device for predicting the state of materials during preservation. It constructs a geometric model of the material and its material parameters, and then builds a physical field based on these parameters. Control equations for this physical field are then established, including heat transfer control equations based on internal heat transfer within the material and heat transfer between the material and the medium, and mass transfer control equations based on the material's diffusion within the environment. Solving these control equations yields simulation results of the material's state during preservation. Based on these simulation results, the preservation process can be precisely controlled, better maintaining the quality of the material.

[0146] In summary, the present invention may have many other embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art can devise various corresponding changes and modifications based on the present invention, but these corresponding changes and modifications should all fall within the protection scope of the patent application filed by the present invention.

Claims

1. A method for predicting the state of materials during preservation, characterized in that, Includes the following steps: Establish a geometric model of the material based on its shape; The material parameters of the geometric model are determined based on the preservation process; A physical field is constructed based on the geometric model and the material parameters; A control equation is constructed for the physical field, wherein the heat transfer control equation for the preservation process is constructed through the heat transfer inside the material and the heat transfer between the material and the medium, and the mass transfer control equation for the preservation process is constructed through the mass diffusion of the material in the environment. Set initial conditions, boundary conditions, and physical field parameters for the physical field; The geometric model is meshed; Solve the governing equations and perform post-processing on the results; wherein, The heat transfer control equation for the preservation process, which is constructed through heat transfer within the material and heat transfer between the material and the medium, further includes: Based on the energy conservation principle of heat transfer in a medium, the governing equations for heat transfer within a material are constructed, including: Fourier's heat transfer law is used to construct the control equation for heat transfer inside the material; The heat transfer control equations between the material and the environment are constructed by considering the heat transfer at the material boundaries within the medium, including: The heat transfer control equation between the material and the environment is constructed using Newton's law of cooling. The mass transfer control equation for the preservation process is constructed based on the mass diffusion of the material in the environment, including: The mass transfer control equation of the material in the environment is constructed using Fick's second diffusion law.

2. The method as described in claim 1, characterized in that, The steps of constructing the governing equations for heat transfer within a material using Fourier's heat transfer law further include: ,in, Density is expressed in kg / m³. 3 , This represents the constant-pressure heat capacity, in J / (kg / K), where J is the joule, K is the Kelvin temperature, T represents the material temperature in K, and t represents time in seconds. Represents the vector differential operator. Represents the net heat flux density vector, in units of W / m³. 2 W represents watts, Q represents the internal heat source, W / m 3 ; ,in, This indicates the rate of water evaporation, expressed in kg / (m³). 3 *s), The latent heat of vaporization of water is expressed in J / kg. ,in, This represents the evaporation rate constant, in units of 1 / s. This represents the density of the liquid phase, in kg / m³. 3 , This represents the saturated vapor pressure, in Pa. This indicates the pressure inside the vacuum chamber, in Pa; and, Where A, B, and C are constants, and T represents the material temperature in K.

3. The method as described in claim 1, characterized in that, The step of constructing the heat transfer control equation between the material and the environment using Newton's law of cooling further includes: ,in, This represents the net heat flux density vector at the material boundary, in W / m³. 2 , This represents the heat transfer coefficient at the boundary, in units of W / (m²). 2 *K), The external ambient temperature is represented by K, and T represents the material temperature, also in K.

4. The method as described in claim 1, characterized in that, The step of constructing the mass transfer control equation of the material in the environment using Fick's second diffusion law further includes: ,in, Indicates the volume fraction of the liquid phase. This represents the apparent liquid diffusion coefficient, expressed in m² / s. ;in, Represents a proportionality constant. This indicates the residual saturation.

5. The method as described in claim 1, characterized in that, The steps of solving the governing equations and post-processing the solution results further include: Set the solver to transient; Set the output timing step according to the preservation process requirements; The plotting group is set up to plot the data results based on the solution results of the control equations.

6. A material state prediction device during preservation, used to implement the method as described in any one of claims 1 to 5, characterized in that, include: The geometric model building module establishes a geometric model of the material based on its shape. The material parameter module determines the material parameters of the geometric model based on the preservation process. The physics field construction module constructs a physics field based on the geometric model and the material parameters. This physics field construction module further includes: The control equation construction module constructs control equations for the physical field, including heat transfer control equations for the preservation process based on heat transfer within the material and heat transfer between the material and the medium, and mass transfer control equations for the preservation process based on the material diffusion in the environment. The physics field setting module sets the initial conditions, boundary conditions, and physics field parameters for the physics field. The mesh generation module performs mesh generation on the geometric model; The solution and post-processing module solves the governing equations and performs post-processing on the solution results.

7. A vacuum cooling device, characterized in that, include: A vacuum chamber is used to provide a vacuum environment for materials. A vacuum unit includes a vacuum pump and a vacuum valve connected to the vacuum pump, the vacuum pump and the vacuum valve being used to provide a vacuum environment for the vacuum chamber; A cooling unit, connected to the vacuum chamber, is used to provide cooling water; The control unit is connected to the vacuum pump and the cooling unit; The material state prediction device during the preservation process as described in claim 6 is connected to the control unit.

8. A storage medium for storing a computer control program, characterized in that, The computer control program is used to perform the steps of the method as described in any one of claims 1 to 5.

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