A method and device for obtaining parameters of a microwave heating system based on field-circuit combination

Abstract

The application discloses a method and device for obtaining microwave heating system parameters based on field-circuit combination. The application has the characteristics of simple modeling method, intuitive and reliable model, reasonable parameter selection, etc. On the premise of retaining certain accuracy, the numerical analysis process is simplified, the problem of excessive occupation of computer processor time and memory by numerical simulation technology can be solved, the reliability of simulation results is improved, repeated simulation and test adjustment is avoided, a large amount of manpower, material resources and financial resources are saved, work efficiency and work effect are improved. Specifically: through three-dimensional modeling of the heating system, two-port network division of the three-dimensional model, and combination of field analysis and circuit analysis, the parameters of the electromagnetic field in which the whole heated material in the microwave heating system is located can be effectively obtained. The application has the characteristics of accuracy and rapidity, the difficulty of field analysis on the heating cavity is reduced, and is more suitable for engineering application.

Description

TECHNICAL FIELD

[0001] The present application relates to a method and device for obtaining parameters of a microwave heating system based on field-circuit combination, and belongs to the field of microwave heating modeling and simulation. BACKGROUND

[0002] Microwave heating technology combines two popular research fields of electromagnetic field and heat, and converts microwave energy into heat energy through the absorption of heated materials, thereby achieving the heating of the materials. Microwave heating has the advantages of high efficiency, energy saving, selective heating, and clean and pollution-free, and has been widely used in metallurgy, chemical industry, pharmaceuticals, food and other aspects.

[0003] In the analysis of microwave heating, the temperature of the heated material is obtained by analyzing the electromagnetic field distribution of the material. The distribution of the electromagnetic field in the microwave resonant cavity is a boundary value problem in mathematical physics. So far, there are mainly four methods to solve the boundary value problem of electromagnetic distribution:

[0004] (1) Graphical method

[0005] The graphical method has a long history. Its advantage is that it is more intuitive, and its disadvantage is that the calculation accuracy is not high, which cannot meet the needs of modern engineering calculation.

[0006] (2) Analytical method

[0007] The analytical method is a relatively mature method so far. Before the advent of numerical analysis based on computer technology, the boundary value problem of electromagnetic distribution was mainly solved by the analytical method.

[0008] (3) Simulation method

[0009] The simulation method is to measure the static electromagnetic field with the same field equation, the same boundary condition and the same boundary condition through experiment, to realize the simulation of electromagnetic field distribution.

[0010] (4) Numerical analysis method

[0011] With the rapid development of modern computers, the full-wave analysis method of electromagnetic field based on field theory becomes possible. Through high-performance computers, numerical and program forms are used to replace analytical forms to describe electromagnetic field problems. Difference is used to replace differentiation, and finite summation is used to replace integration, so that the analytical problem is converted into a difference equation or algebraic equation problem.

[0012] Because the heating cavity of microwave heating is often a finite closed space, there are multiple distribution modes of microwaves in the finite space, for such a complex electromagnetic field, the finite element method is widely used in modeling due to its ability to handle irregular geometry and boundary conditions, spatial and temporal characteristics. However, in commercial software such as COMSOL based on the finite element method, a large number of grids need to be divided when analyzing the microwave heating system, and the solving process is very slow. In some engineering applications, it is often limited by computer storage capacity and execution time, and an effective method is needed to solve the above problems. SUMMARY

[0013] The application provides a method and device for obtaining parameters of a microwave heating system based on field-circuit combination, which can effectively obtain the parameters of the electromagnetic field in which the whole heated material is located in the microwave heating system by three-dimensional modeling of the heating system, dividing the two-port network of the three-dimensional model, and combining field analysis and circuit analysis.

[0014] The technical scheme of the application is: a method for obtaining parameters of a microwave heating system based on field-circuit combination, comprising:

[0015] Step 1, determining the three-dimensional model structure composition of the microwave heating system;

[0016] Step 2, establishing a three-dimensional model of the three-dimensional microwave heating system according to the three-dimensional model structure composition of the microwave heating system, and setting a microwave incident port 1;

[0017] Step 3, constructing a two-port network for the heated material and the iris 2 respectively existing in the cavity 3 of the three-dimensional model of the three-dimensional microwave heating system by means of the imaginary plane 5;

[0018] Step 4, performing field analysis on each two-port network to finally obtain the scattering parameters of the heated material and the iris corresponding to the two-port network;

[0019] Step 5, establishing a qualitative equivalent circuit model of the microwave heating system corresponding to the three-dimensional model of the microwave heating system; wherein the microwave field source corresponds to the current source of the equivalent circuit model, and the scattering parameters in the microwave field correspond to the impedance parameters in the equivalent circuit model;

[0020] Step 6, solving the equivalent circuit model according to the scattering parameters to obtain the amplitude of the electromagnetic field in which the whole heated material is located.

[0021] The three-dimensional model structure composition of the microwave heating system includes the iris 2, the cavity 3, the microwave waveguide 4 and the heated material; the heated material includes the material type, properties and size of the heated material, and the properties of the heated material include the dielectric constant.

[0022] Each two-port network adopts two imaginary planes perpendicular to Y-axis; wherein, Y-axis is perpendicular to iris 2, and iris 2 is parallel to microwave incident port 1.

[0023] If the heated material exists one, two-port networks are respectively constructed for the heated material and the iris; if the heated material exists multiple, one two-port network is shared by the heated materials intersecting based on Y-axis in the cavity, otherwise, a two-port network is constructed separately.

[0024] The Step4 specifically is: the scattering parameters of the heated material and the iris in the three-dimensional model of the microwave heating system are solved by using the finite element method.

[0025] The scattering parameters of the heated material and the iris in the three-dimensional model of the microwave heating system are solved by using the finite element method, and the specific steps are as follows:

[0026] Step4.1, according to the solving object of the scattering parameter, select the two-port network to be solved, and determine the two-port network incident port and the two-port network reflection port; wherein, the imaginary plane close to the microwave incident port 1 in the two-port network is the two-port network incident port, and the imaginary plane far away from the microwave incident port 1 in the two-port network is the two-port network reflection port;

[0027] Step4.2, according to the geometric characteristics of the solving domain, the entire solving domain is meshed;

[0028] Step4.3, according to the number of nodes of the divided element and the requirement for the approximation accuracy, select the interpolation function meeting the requirement as the element basis function, and approximate the solving function with the linear combination expression of the element basis function, so as to obtain the algebraic equation containing specific coefficients;

[0029] Step4.4, the element finite element equation in the entire solving domain is overall synthesized to obtain the scattering parameter of the entire solving domain as the scattering parameter of the solving object selected in Step4.1.

[0030] The scattering parameter in the microwave field corresponds to the impedance parameter in the equivalent circuit model, specifically: the real part of the impedance parameter corresponds to the real part of the equivalent impedance of the iris and the real part of the equivalent impedance of the heated material obtained by converting the scattering parameter, and the imaginary part corresponds to the imaginary part of the equivalent impedance of the short-circuit end of the cavity and the imaginary part of the equivalent impedance of the heated material obtained by converting the scattering parameter.

[0031] The amplitude of the electromagnetic field in which the entire heated material is located is represented by the load voltage value in the equivalent circuit model.

[0032] A device for obtaining parameters of a microwave heating system based on field-circuit combination, comprising:

[0033] A determining module is configured to determine a structure composition of a three-dimensional model of a microwave heating system;

[0034] A first establishing module is configured to establish a three-dimensional model of the three-dimensional model of the microwave heating system according to the structure composition of the three-dimensional model of the microwave heating system, and set a microwave incident port 1;

[0035] A constructing module is configured to construct a two-port network for each of the heated material and the iris 2 in the cavity 3 in the three-dimensional model of the microwave heating system through an imaginary plane 5;

[0036] An executing module is configured to perform field analysis on each two-port network, and finally obtain the scattering parameters of the heated material and the iris corresponding to the two-port network;

[0037] A second establishing module is configured to establish a qualitative equivalent circuit model of the microwave heating system corresponding to the three-dimensional model of the microwave heating system; wherein a microwave field source corresponds to a current source of the equivalent circuit model, and a scattering parameter in the microwave field corresponds to an impedance parameter in the equivalent circuit model;

[0038] An acquiring module is configured to solve the equivalent circuit model according to the scattering parameters, and acquire an amplitude of an electromagnetic field electric field in which the heated material is located.

[0039] A computer readable storage medium, the computer readable storage medium stores a computer program, the computer program is executed by a processor to realize the method for obtaining the parameter of the microwave heating system based on the field and the circuit combination in any one of the above.

[0040] The present application has the advantages that: the present application has the characteristics of simple modeling method, intuitive and reliable model, reasonable parameter selection, etc., under the premise of preserving a certain accuracy, simplifies the numerical analysis process, can solve the problem of excessive occupation of computer processor time and memory by numerical simulation technology, at the same time improves the reliability of simulation results, avoids repeated simulation and test adjustment, saves a lot of manpower, material resources and financial resources, improves work efficiency and work effect; specifically: through three-dimensional modeling of the heating system, two-port network division of the three-dimensional model, and combination of field analysis and circuit analysis, the parameter of the electromagnetic field in which the heated material is located in the microwave heating system can be effectively obtained, which has the characteristics of accuracy and rapidity, reduces the difficulty of field analysis of the heating cavity, and is more suitable for engineering application. BRIEF DESCRIPTION OF DRAWINGS

[0041] Figure 1 The flowchart of the present application is shown in the figure;

[0042] Figure 2 The three-dimensional model of the microwave heating system established in the present application is shown in the figure;

[0043] Figure 3It is a design idea diagram of the microwave heating system based on the field-circuit combination analysis of the application;

[0044] Figure 4 It is a side view of the partition diagram of the two-port network of the three-dimensional simulation model in the application;

[0045] Figure 5 It is an equivalent circuit diagram of the microwave heating cavity and the waveguide as a whole in the application.

[0046] The numbers in the figure are: 1-microwave incident port, 2-iris, 3-cavity, 4-microwave waveguide, 5-imaginary plane, 6-mullite rod. DETAILED DESCRIPTION

[0047] The application will be further described below in combination with the drawings and examples, but the content of the application is not limited to the scope described.

[0048] Example 1: As shown in the figure, a method for obtaining parameters of a microwave heating system based on field-circuit combination, comprising: Figures 1-5

[0049] Step 1, determining the structure composition of the three-dimensional model of the microwave heating system;

[0050] Step 2, establishing a three-dimensional model of the microwave heating system in the cmosol software according to the structure composition of the three-dimensional model of the microwave heating system, and setting the microwave incident port 1;

[0051] Step 3, constructing two-port networks for the heated material and the iris 2 respectively existing in the cavity 3 of the three-dimensional model of the microwave heating system through the imaginary plane 5;

[0052] Step 4, performing field analysis on each two-port network to finally obtain the scattering parameters of the heated material and the iris corresponding to the two-port network;

[0053] Step 5, establishing a qualitative equivalent circuit model of the microwave heating system corresponding to the three-dimensional model of the microwave heating system; wherein the microwave field source corresponds to the current source of the equivalent circuit model, and the scattering parameters in the microwave field correspond to the impedance parameters in the equivalent circuit model;

[0054] Step 6, solving the equivalent circuit model according to the scattering parameters to obtain the amplitude of the electromagnetic field electric field in which the whole heated material is located; using the load voltage value in the equivalent circuit model to represent the amplitude of the electromagnetic field electric field in which the whole heated material is located.

[0055] Optionally, the structure composition of the three-dimensional model of the microwave heating system includes the iris 2, the cavity 3, the microwave waveguide 4, and the heated material; the heated material includes the material type, the property, and the size of the heated material, and the property of the heated material includes the dielectric constant. ​

[0056] Optionally, each two-port network adopts two imaginary planes perpendicular to Y-axis; wherein, Y-axis is perpendicular to iris 2, and iris 2 is parallel to microwave incident port 1.

[0057] Optionally, if there is one heated material, two-port networks are respectively constructed for the heated material and iris 2; if there are multiple heated materials, one two-port network is shared by the heated materials which cross each other based on Y-axis in the cavity, otherwise, a separately constructed two-port network is adopted (for example, if there are two heated materials, if there is a cross in Y-axis, i.e. there is a common Y coordinate, then the two heated materials share one two-port network; if there are two heated materials, if there is no cross in Y-axis, i.e. separation, then the two heated materials construct two two-port networks; another iris 2 constructs one two-port network).

[0058] Optionally, Step 4 is specifically: the finite element method is adopted to obtain the scattering parameters of the heated material and the iris in the three-dimensional model of the microwave heating system.

[0059] Optionally, the finite element method is adopted to obtain the scattering parameters of the heated material and the iris in the three-dimensional model of the microwave heating system, and the specific steps are as follows:

[0060] Step 4.1, according to the solving object of the scattering parameter, selecting the two-port network to be solved, and determining the incident port of the two-port network and the reflection port of the two-port network; wherein, the imaginary plane close to the microwave incident port 1 in the two-port network is the incident port of the two-port network, and the imaginary plane far away from the microwave incident port 1 in the two-port network is the reflection port of the two-port network; if the heated material is solved, the two-port network corresponding to the heated material is selected, and the others are the same;

[0061] Step 4.2, according to the geometric characteristics of the solving domain, the entire solving domain is meshed;

[0062] Step 4.3, according to the number of nodes of the meshed unit and the requirement for the approximation accuracy, selecting an interpolation function meeting the requirement as the unit base function, and approximating the solving function with the linear combination expression of the unit base function, so as to obtain an algebraic equation containing specific coefficients;

[0063] Step 4.4, the unit finite element equation in the entire solving domain is overall synthesized to obtain the scattering parameter of the entire solving domain, which is the scattering parameter of the solving object selected in Step 4.1.

[0064] Optionally, the scattering parameters in the microwave field correspond to the impedance parameters in the equivalent circuit model. Specifically, the real part of the impedance parameter corresponds to the real part of the iris equivalent impedance and the real part of the heated material equivalent impedance obtained by converting the scattering parameters, and the imaginary part corresponds to the imaginary part of the cavity short-circuit terminal equivalent impedance and the imaginary part of the heated material equivalent impedance obtained by converting the scattering parameters.

[0065] Example 2: As Figures 1-5 As shown, an optional specific method of the present invention will be described in detail below. This embodiment of the invention takes microwave heating of a mullite rod in a single-mode cavity as an example, obtaining the equivalent model and related parameters of the heating system in a two-dimensional simulation circuit.

[0066] Three-dimensional model of microwave heating system as follows Figure 2 As shown, the structure is rectangular, with the X-axis representing the width, the Y-axis representing the length, and the Z-axis representing the height. It includes a microwave entrance port 1, an iris 2, a cavity 3, a microwave waveguide 4, an imaginary plane 5, and a mullite rod 6. Microwaves enter the cavity 3 through the microwave waveguide 4 and the iris 2. The iris 2 serves as the boundary between the cavity 3 and the microwave waveguide 4, with scattering boundary conditions set. The cavity 3 is made of metal and has ideal boundary conditions. The cavity contains an air domain, serving as the energy exchange site for the conversion of microwave energy into heat energy. The mullite rod 6 is placed within the cavity 3. Two-port networks are constructed by using an imaginary plane 5 to connect the mullite rods 6 and iris 2 in the cavity 3. Each two-port network uses two imaginary planes perpendicular to the Y-axis. Mullite rods 6 that intersect based on the Y-axis in the cavity share a two-port network; otherwise, a separate two-port network is used. In the example of this invention, there is only one mullite rod 6, so two two-port networks are established in the entire cavity. The scattering parameters of each two-port network are calculated, and then the scattering parameters are converted into impedance parameters to achieve field-path integration.

[0067] Figure 3 This is a schematic diagram illustrating the design concept of the field-circuit combination of this invention. In circuit analysis, the circuit elements mainly include current source terms and impedance terms. The current source term corresponds to the microwave source in the three-dimensional model of the microwave heating system; the impedance term corresponds to the microwave loss in the system. The impedance term is divided into real and imaginary parts. The real part corresponds to the real part of the equivalent impedance of the iris and the real part of the equivalent impedance of the heated material, while the imaginary part corresponds to the imaginary part of the equivalent impedance of the cavity short-circuit terminal and the imaginary part of the equivalent impedance of the heated material. This invention, through three-dimensional modeling of the heating system, partitioning the two-port network of the three-dimensional model, and combining field analysis and circuit analysis (reflected in the conversion between scattering parameters and impedance parameters), can effectively obtain the amplitude of the electromagnetic field of the heated material as a whole in the microwave heating system.

[0068] Figure 4 and Figure 5 This corresponds to the 3D model and the equivalent circuit. Figure 4 forFigure 2 side view, including microwave incident port 1, iris 2, cavity 3, microwave waveguide 4, imaginary plane 5 dividing two-port network, mullite rod 6, iris 2 corresponds to Figure 5 port, cavity 3 corresponds to Figure 5 transmission line, imaginary plane 5 dividing two-port network corresponds to Figure 5 A, B, C, D four imaginary planes in, mullite rod 6 corresponds to Figure 5 sample in.

[0069] The relationship between the power supply, impedance and other parameters of the equivalent circuit and the electric field, scattering parameters and other parameters of the electromagnetic field can be expressed as:

[0070] 1, the relationship between microwave source incident power and cavity electric field amplitude can be expressed as:

[0071] (1)

[0072] Wherein, represents the cavity electric field amplitude; P represents the microwave source incident power; represents the microwave angular frequency; represents the vacuum dielectric constant; V represents the cavity volume.

[0073] 2, the relationship between the equivalent impedance Z a of the iris and the scattering parameters can be expressed as:

[0074] (2)

[0075] Wherein:

[0076] 3, the relationship between the equivalent impedance Z b , Z c of the heated material and the scattering parameters can be expressed as:

[0077] (3)

[0078] (4)

[0079] 4, the relationship between the equivalent impedance of the right side of each imaginary plane and the scattering parameters is respectively expressed as, that is, Figure 5As shown in the structure, Z4 represents the impedance of the right part of the plane where the label D is located, that is, the equivalent impedance of the short end of the cavity; Z3 represents the impedance of the right part of the plane where the label C is located, that is, the equivalent impedance of the short end of the cavity + the equivalent impedance of the heated material; Z2 represents the impedance of the right part of the plane where the label B is located, that is, the equivalent impedance of the short end of the cavity + the equivalent impedance of the heated material + transmission loss; Z1 represents the impedance of the right part of the plane where the label A is located, that is, the equivalent impedance of the short end of the cavity + the equivalent impedance of the heated material + transmission loss + iris equivalent impedance, that is, the impedance and in the equivalent circuit model, that is, Figure 3 The middle impedance; if there are multiple two-port networks of heated materials, the solving method is the same:

[0080] (5)

[0081] (6)

[0082] (7)

[0083] (8)

[0084] 5, The relationship between the electric field of the heated material and the cavity electric field and the equivalent current source can be represented as:

[0085] E= k I s G s + G x +j[ B x − Y 0 cot k 10 L 2 )] = E 0 1+ g x +j b x − y 0 cot k 10 L 2 (9)

[0086] Wherein: The amplitude of the electromagnetic field electric field in which the whole heated material is located; The current source; , , , Can be obtained by

[0087] ​In embodiment 3, a device for obtaining parameters of a microwave heating system based on field-circuit combination is provided, and the device comprises: a determination module configured to determine a structure of a three-dimensional model of the microwave heating system; a first establishment module configured to establish a three-dimensional model of the three-dimensional model of the microwave heating system in a cmosol software according to the structure of the three-dimensional model of the microwave heating system, and set a microwave incident port 1; a construction module configured to construct two-port networks for heated materials and iris 2 in a cavity 3 in the three-dimensional model of the microwave heating system by means of an imaginary plane 5; an execution module configured to perform field analysis on each two-port network, and finally obtain scattering parameters of the heated materials and the iris corresponding to the two-port networks; a second establishment module configured to establish a qualitative equivalent circuit model of the microwave heating system corresponding to the three-dimensional model of the microwave heating system; wherein a microwave field source corresponds to a current source of the equivalent circuit model, and scattering parameters in the microwave field correspond to impedance parameters in the equivalent circuit model; and an acquisition module configured to solve the equivalent circuit model according to the scattering parameters, and obtain an amplitude of an electromagnetic field electric field in which the heated materials as a whole are located. It should be noted that the above modules can be realized by software or hardware. For example, for the latter, the above modules can be located in the same processor, and / or the above modules can be located in different processors in any combination. The terms "first", "second", and the like in the specification and claims of the present application and the above drawings are used to distinguish similar objects, and do not necessarily indicate a specific order or sequence. It should be understood that the data used in this way can be interchanged under appropriate circumstances, so that the embodiments of the application described herein can be implemented in an order other than those illustrated or described herein.

[0088] According to another aspect of the embodiments of the present application, a processor is provided for running a program, wherein the program performs the method for obtaining parameters of a microwave heating system based on field-circuit combination when running.

[0089] According to another aspect of the embodiments of the present application, a computer readable storage medium is provided, and a computer program is stored on the computer readable storage medium, wherein the computer program is executed by a processor to implement the method for obtaining parameters of a microwave heating system based on field-circuit combination according to any one of the above embodiments.

[0090] The specific embodiments of the present application are described in detail above with reference to the accompanying drawings, but the present application is not limited to the above embodiments, and various changes can be made within the knowledge of those skilled in the art without departing from the spirit of the present application.

Claims

1. A method for obtaining parameters of a microwave heating system based on field-path combination, characterized in that: include: Step 1: Determine the structural composition of the three-dimensional model of the microwave heating system; Step 2: Based on the three-dimensional model of the microwave heating system, establish a three-dimensional model of the microwave heating system and set the microwave incident port (1). Step 3: Using the imaginary plane (5), construct two-port networks for the heated material and iris (2) in the cavity (3) of the three-dimensional microwave heating system model; Step 4: Perform field analysis on each two-port network to finally determine the heated material and iris scattering parameters corresponding to the two-port network. Step 5: Based on the three-dimensional model of the microwave heating system, establish a qualitative equivalent circuit model of the microwave heating system; where the microwave field source corresponds to the current source in the equivalent circuit model, and the scattering parameters in the microwave field correspond to the impedance parameters in the equivalent circuit model. Step 6: Based on the scattering parameters, solve the equivalent circuit model to obtain the amplitude of the electromagnetic field and electric field of the heated material as a whole. Step 4 specifically involves using the finite element method to determine the parameters of the heated material and iris scattering in the three-dimensional model of the microwave heating system. The specific steps for using the finite element method to determine the heated material and iris scattering parameters in the three-dimensional model of the microwave heating system are as follows: Step 4.1: Based on the object of solving the scattering parameters, select the two-port network to be solved and determine the incident port and reflection port of the two-port network; wherein, the imaginary plane in the two-port network that is close to the microwave incident port (1) is the incident port of the two-port network, and the imaginary plane in the two-port network that is far away from the microwave incident port (1) is the reflection port of the two-port network. Step 4.2: Based on the geometric characteristics of the solution domain, divide the entire solution domain into mesh elements; Step 4.3: Based on the number of nodes in the subdivided unit and the accuracy requirements, select an interpolation function that meets the requirements as the unit basis function, and approximate the solution function with a linear combination expression of the unit basis functions to obtain an algebraic equation containing specific coefficients. Step 4.4: Combine the element finite element equations in the entire solution domain to obtain the scattering parameters of the entire solution domain, which will be used as the scattering parameters of the solution object selected in Step 4.

1.

2. The method for obtaining microwave heating system parameters based on field-path combination according to claim 1, characterized in that: The three-dimensional model structure of the microwave heating system includes an iris (2), a cavity (3), a microwave waveguide (4), and a material to be heated; the material to be heated includes the material type, properties and size of the material to be heated, and the properties of the material to be heated include the dielectric constant.

3. The method for obtaining microwave heating system parameters based on field-path combination according to claim 1, characterized in that: Each two-port network uses two imaginary planes perpendicular to the Y-axis; wherein the Y-axis is perpendicular to the iris (2) and the iris (2) is parallel to the microwave incident port (1).

4. The method for obtaining microwave heating system parameters based on field-path combination according to claim 1, characterized in that: If there is one heated material, then a two-port network is constructed for the heated material and the iris (2) respectively; if there are multiple heated materials, a two-port network is shared for heated materials that intersect based on the Y-axis in the cavity, otherwise, a separately constructed two-port network is used.

5. The method for obtaining microwave heating system parameters based on field-path combination according to claim 1, characterized in that: The scattering parameters in the microwave field correspond to the impedance parameters in the equivalent circuit model. Specifically, the real part of the impedance parameter corresponds to the real part of the iris equivalent impedance and the real part of the heated material equivalent impedance obtained by converting the scattering parameters, while the imaginary part corresponds to the imaginary part of the cavity short-circuit terminal equivalent impedance and the imaginary part of the heated material equivalent impedance obtained by converting the scattering parameters.

6. The method for obtaining microwave heating system parameters based on field-path combination according to claim 1, characterized in that: The amplitude of the electromagnetic field of the heated material as a whole is represented by the load voltage value in the equivalent circuit model.

7. A device for obtaining microwave heating system parameters based on field-path combination, characterized in that: include: The module is used to determine the structural composition of the three-dimensional model of the microwave heating system. The first module is used to establish a three-dimensional model of the microwave heating system based on the three-dimensional model structure of the microwave heating system, and to set the microwave incident port (1). The construction module is used to construct two-port networks for the heated material and iris (2) in the cavity (3) of the three-dimensional model of the three-dimensional microwave heating system through the imaginary plane (5); The execution module is used to perform field analysis on each two-port network and finally determine the heated material and iris scattering parameters corresponding to the two-port network. The second module is used to establish a qualitative equivalent circuit model of the microwave heating system corresponding to the three-dimensional model of the microwave heating system; wherein, the microwave field source corresponds to the current source of the equivalent circuit model, and the scattering parameters in the microwave field correspond to the impedance parameters of the equivalent circuit model. The acquisition module is used to solve the equivalent circuit model based on the scattering parameters and obtain the amplitude of the electromagnetic field and electric field of the entire heated material. The finite element method was used to determine the parameters of the heated material and iris scattering in the three-dimensional model of the microwave heating system. The specific steps for using the finite element method to determine the heated material and iris scattering parameters in the three-dimensional model of the microwave heating system are as follows: Step 4.1: Based on the object of solving the scattering parameters, select the two-port network to be solved and determine the incident port and reflection port of the two-port network; wherein, the imaginary plane in the two-port network that is close to the microwave incident port (1) is the incident port of the two-port network, and the imaginary plane in the two-port network that is far away from the microwave incident port (1) is the reflection port of the two-port network. Step 4.2: Based on the geometric characteristics of the solution domain, divide the entire solution domain into mesh elements; Step 4.3: Based on the number of nodes in the subdivided unit and the accuracy requirements, select an interpolation function that meets the requirements as the unit basis function, and approximate the solution function with a linear combination expression of the unit basis functions to obtain an algebraic equation containing specific coefficients. Step 4.4: Combine the element finite element equations in the entire solution domain to obtain the scattering parameters of the entire solution domain, which will be used as the scattering parameters of the solution object selected in Step 4.

1.

8. A computer-readable storage medium, characterized in that: A computer program is stored on the computer-readable storage medium, which, when executed by a processor, implements the method for obtaining microwave heating system parameters based on field-path combination as described in any one of claims 1 to 6.

Images