Temperature distribution calculation method and device for mixed gas isolation switch and medium

Abstract

The invention relates to the field of high-voltage equipment technology detection, in particular to a temperature distribution calculation method and device for a mixed gas isolation switch and a medium. According to the method, a three-dimensional equal-proportion electromagnetic field-temperature field-fluid field coupling calculation model is established, and the temperature distribution of the mixed gas isolation switch is calculated by adopting a multi-physical field coupling method; heating power obtained through electromagnetic field calculation is used as a heat source for temperature field calculation, convective heat transfer process calculation is carried out through mixed gas physical property parameters obtained according to the fluid multi-component transmission principle, the accuracy is high, a resistive film is arranged at the inserting position of a movable contact and a static contact to simulate the poor contact state of the movable contact and the static contact of the disconnecting switch, and the accuracy is high. Therefore, a temperature rise test with a long period and a large error does not need to be carried out, the temperature distribution rule during normal operation and poor contact of the mixed gas isolation switch can be researched and analyzed, and technical support is provided for infrared temperature measurement and fault diagnosis of the mixed gas isolation switch.

Description

Technical Field

[0001] The invention relates to the technical field of high-voltage equipment state detection, and in particular to a temperature distribution calculation method, a device and a medium for a mixed gas isolating switch. Background Art

[0002] Gas-insulated metal-enclosed switchgear (GIS) containing SF6 / N2 mixed gas can greatly reduce SF6 gas emissions and effectively reduce environmental pollution. Relevant theoretical research and pilot operation experience show that a mixed gas ratio of SF6:N2=3:7 and appropriately increasing the gas pressure can achieve a good balance between environmental protection performance and insulation performance. It has now been gradually applied to the disconnector gas chamber of GIS with voltage levels of 220kV and below.

[0003] However, the amount of SF6 / N2 mixed gas disconnectors installed is gradually increasing, and the evaluation method of their operating status also needs to be studied urgently. After replacing the traditional pure SF6 gas with mixed gas, the change in gas convection capacity is bound to have different effects on the temperature distribution inside the disconnector gas chamber. In particular, when the disconnector contacts heat up due to poor contact, the temperature changes reflected on the shell surface are more difficult to grasp. Therefore, it is necessary to study the temperature distribution of SF6 / N2 mixed gas disconnectors, especially when the disconnectors have poor contact defects.

[0004] If the temperature rise test of the SF6 / N2 mixed gas GIS disconnector chamber is carried out in the laboratory, the test cycle is long, there are many error factors, and it is difficult to simulate the different degrees of poor contact defects due to the gas filling and temperature probe arrangement. If the temperature distribution calculation method of the SF6 / N2 mixed gas disconnector coupled with multi-physical fields can be established by simulation software, the temperature distribution law inside and outside the mixed gas disconnector chamber during normal operation and poor contact can be quickly and accurately studied and analyzed.

[0005] It should be noted that the information disclosed in the above background technology section is only used to enhance the understanding of the background of the present application, and therefore may include information that does not constitute the prior art known to ordinary technicians in the field. Summary of the invention

[0006] In view of the defects of the prior art, the present invention provides a temperature distribution calculation method, device and medium for a mixed gas isolating switch. By establishing a three-dimensional proportional electromagnetic field-temperature field-fluid field coupling calculation model and setting a resistance film at the joint of the moving and static contacts to simulate the poor contact state of the moving and static contacts of the isolating switch, there is no need to conduct a temperature rise test with a long cycle and large error. The temperature distribution law of the SF6 / N2 mixed gas isolating switch during normal operation and poor contact can be studied and analyzed, providing technical support for infrared temperature measurement and fault diagnosis of the SF6 / N2 mixed gas isolating switch.

[0007] In order to solve the technical problem, the technical solution adopted by the present invention is: a temperature distribution calculation method for a mixed gas isolating switch, comprising the following steps: S1. Perform three-dimensional modeling and finite element meshing on the gas chamber of the mixed gas disconnector. The model is an electromagnetic field-temperature field-fluid field coupling calculation model, and parameters are assigned to each material in the model; S2, electromagnetic field-temperature field coupling, first use the conductor AC impedance empirical formula under the influence of skin effect to calculate the conductor heating power, use the coaxial conductor magnetic field distribution empirical formula and Faraday's law of electromagnetic induction to calculate the shell heating power, then combine the law of conservation of energy in the conductor and shell, and calculate the solid temperature of the mixed gas isolating switch gas chamber through the heat transfer process inside the mixed gas isolating switch conductor and shell; S3, fluid field-temperature field coupling, firstly, according to the principle of fluid multi-component transmission, the physical properties of the mixed gas in the mixed gas isolating switch air chamber are combined, and then the fluid energy conservation equation, mass conservation equation and momentum conservation equation are combined to represent the convective heat transfer process inside the mixed gas, and the gas temperature of the mixed gas isolating switch air chamber is calculated based on the convective heat transfer process; determine the influence of the gas temperature of the mixed gas isolating switch air chamber on the solid temperature, and determine the final solid temperature of the isolating switch air chamber according to the influence; S4. Set up the various parts of the coupling calculation model Initial temperature at time, calculation time step, convergence criterion , let n's initial value be 1; S5, execute steps S2 and S3, calculate Solid temperature and gas temperature of the mixed gas isolating switch gas chamber at the moment; S6: Determine whether the difference between the current temperature of all parts and the previous temperature is less than the convergence criterion If yes, then read the calculation result of the solid temperature distribution. If not, update the material parameters according to the current temperature of each part, set n=n+1, and repeat step S5.

[0008] Furthermore, using the empirical formula of the conductor AC impedance under the influence of the skin effect, the calculation formula for the conductor heating power is: (1) (2) (3), Using the empirical formula of the magnetic field distribution of the coaxial conductor and Faraday's law of electromagnetic induction, the formula for calculating the shell heating power is: (4), in is the heating power of the conductor in Joules, is the effective value of the conductor current, is the AC impedance per unit length of the conductor, For its actual part, and are the inner and outer diameters of the hollow conductor, , is the angular frequency, is the magnetic permeability of the conductor material, , , , are one type of zero-order Bessel function, one type of first-order Bessel function, two types of zero-order Bessel function, and two types of first-order Bessel function, respectively. is the temperature of the solid in the gas chamber of the mixed gas isolating switch, which is the unknown quantity to be determined. , The conductor material is at temperature 、 Resistivity at 20°C, is the temperature coefficient of resistivity of the conductor material, is the heat generation power of the shell circulation, and are the inner diameter and outer diameter of the shell respectively; the heat generation power of the conductor and the shell is used as a heat source to excite the solid temperature calculation of the gas chamber of the mixed gas disconnector; Combined with the law of energy conservation in the conductor and shell, the heat transfer process inside the conductor and shell of the mixed gas disconnector can be expressed as: (5) (6) (7) (8) in: , , are the density, specific heat capacity and thermal conductivity of the conductor / shell, The heat generated by the conductor / shell itself per unit length; It is the heat transfer inside the solid material; It is the heat radiation heat exchange between the solid and the shell; is the Stefan Boltzmann constant; and They are the outer surface temperature of the conductor and the inner surface temperature of the shell, which are read during the iterative calculation process; and are the emissivities of the outer surface of the conductor and the inner surface of the shell, respectively; is the Laplace operator.

[0009] Furthermore, according to the principle of multi-component transmission of fluids, the physical properties of the mixed gas in the gas chamber of the mixed gas isolation switch are combined to obtain: (9) , in , , , They are the density, specific heat capacity at constant pressure, thermal conductivity, and dynamic viscosity of the mixed gas, respectively. , , , are the density, specific heat capacity at constant pressure, thermal conductivity, and dynamic viscosity of gas 1, , , , are the density, specific heat capacity at constant pressure, thermal conductivity, and dynamic viscosity of gas 2, , are the mass fractions of gas 1 and gas 2 in the mixed gas respectively; Combining the fluid energy conservation equation, mass conservation equation and momentum conservation equation, the convective heat transfer process inside the mixed gas can be expressed as: (10) (11) (12) Where: is the temperature of the mixed gas, which is the unknown quantity to be determined; is the Laplace operator; is the gas pressure of the mixed gas isolating switch gas chamber, is the acceleration due to gravity, and are the velocity vector and the identity matrix, respectively. is the density difference caused by thermal expansion of the gas, Represents matrix transpose.

[0010] Furthermore, the mixed gas temperature Temperature of solid materials The influence of is reflected on the interface between the two, satisfying the following interface boundary conditions: (13) Where: and are the outer surface temperature of the conductor and the inner surface temperature of the shell, and are the temperatures of the mixed gas in contact with the outer surface of the conductor and the inner surface of the shell, respectively. and are the normal vectors of the outer surface of the conductor and the inner surface of the shell, respectively.

[0011] Furthermore, the moving contact and the static contact in the electromagnetic field-temperature field-fluid field coupling calculation model are set in a non-contact state, and a resistor film is set in the gap. The change of the contact resistance between the moving and static contacts is simulated by changing the resistance value of the resistor film.

[0012] Furthermore, the mixed gas isolating switch is a SF6 / N2 mixed gas isolating switch.

[0013] Furthermore, a three-dimensional proportional modeling of the mixed gas isolating switch air chamber is performed.

[0014] The present invention also discloses a temperature distribution calculation device for a mixed gas isolating switch, comprising: The three-dimensional modeling and assignment module is used to perform three-dimensional modeling and finite element meshing of the mixed gas disconnector chamber, and to assign parameters to each material in the model. The model built is an electromagnetic field-temperature field-fluid field coupling calculation model; The electromagnetic field-temperature field coupling module first calculates the conductor heating power using the empirical formula of the conductor AC impedance under the influence of the skin effect, and calculates the shell heating power using the empirical formula of the coaxial conductor magnetic field distribution and Faraday's law of electromagnetic induction. Then, combined with the law of conservation of energy in the conductor and the shell, the solid temperature of the mixed gas isolating switch gas chamber is calculated through the heat transfer process inside the conductor and the shell of the mixed gas isolating switch; The fluid field-temperature field coupling module first combines the physical properties of the mixed gas in the mixed gas isolating switch chamber according to the fluid multi-component transmission principle, and then combines the fluid energy conservation equation, mass conservation equation and momentum conservation equation to represent the convective heat transfer process inside the mixed gas. The gas temperature of the mixed gas isolating switch chamber is calculated based on the convective heat transfer process; the influence of the gas temperature of the mixed gas isolating switch chamber on the solid temperature is determined, and the final solid temperature of the isolating switch chamber is determined based on the influence; Initial value setting and calculation module, used to set various parts of the coupling calculation model Initial temperature at time, calculation time step, convergence criterion , set the initial value of n to 1; and trigger the electromagnetic field-temperature field coupling module and the fluid field-temperature field coupling module to calculate Solid temperature and gas temperature of the mixed gas isolating switch gas chamber at the moment; The judgment module is used to judge whether the difference between the current temperature of all parts and the previous temperature is less than the convergence criterion If yes, read the calculation result of solid temperature distribution. If not, update the material parameters according to the current temperature of each part, set n=n+1, trigger the electromagnetic field-temperature field coupling module and fluid field-temperature field coupling module for calculation.

[0015] The present invention also discloses a temperature distribution calculation device for a mixed gas isolating switch, comprising a processor and a memory storing program instructions, wherein the processor is configured to execute the temperature distribution calculation method for the mixed gas isolating switch when running the program instructions.

[0016] The present invention also discloses a storage medium storing program instructions, and when the program instructions are run, the temperature distribution calculation method for the mixed gas isolating switch is executed.

[0017] The beneficial effects of the present invention are as follows: 1. The calculation speed is fast and the efficiency is high, which avoids the shortcomings of long laboratory temperature rise test cycle, waste of manpower and material resources, many error factors, and difficulty in recovering SF6 gas.

[0018] 2. The temperature distribution of the SF6 / N2 mixed gas disconnector is calculated using the multi-physical field coupling method. The heating power obtained by electromagnetic field calculation is used as the heat source for temperature field calculation, and the SF6 / N2 mixed gas physical property parameters obtained based on the multi-component transmission principle of fluid are used to calculate the convective heat transfer process, which has high accuracy.

[0019] 3. The operating conditions of the SF6 / N2 mixed gas isolating switch can be set at will, which is convenient for studying the changing laws of the contact temperature and shell temperature under different operating currents and different contact resistances. The conclusions drawn have certain reference significance for the infrared temperature measurement and defect identification of the SF6 / N2 mixed gas isolating switch, and have good practical application value and promotion value. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a flow chart of the method described in Example 1; Figure 2 It is a structural schematic diagram of a mixed gas isolating switch; Figure 3 It is a schematic diagram of conductor temperature distribution; Figure 4 It is a schematic diagram of shell temperature distribution; Figure 5 It is a schematic diagram of a resistor film provided between the moving and static contacts; Figure 6 Schematic diagram of the curve of the maximum temperature of the conductor and shell surface changing with the contact resistance for different contact resistances; In the figure: 1. shell, 2. insulating torsion bar, 3. pot insulator, 4. moving contact, 5. static contact, 6. contact, 7. contact finger, 8. resistor film. DETAILED DESCRIPTION

[0021] In order to be able to understand the features and technical contents of the embodiments of the present disclosure in more detail, the implementation of the embodiments of the present disclosure is described in detail below in conjunction with the accompanying drawings. The attached drawings are for reference only and are not used to limit the embodiments of the present disclosure. In the following technical description, for the convenience of explanation, a full understanding of the disclosed embodiments is provided through multiple details. However, one or more embodiments can still be implemented without these details. In other cases, to simplify the drawings, well-known structures and devices can be simplified for display.

[0022] The terms "first", "second", etc. in the embodiments of the present disclosure are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the terms used in this way can be interchanged where appropriate, so as to describe the embodiments of the present disclosure described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions.

[0023] Unless otherwise stated, the term "plurality" means two or more.

[0024] In the embodiment of the present disclosure, the character " / " indicates that the preceding and following objects are in an "or" relationship. For example, A / B indicates: A or B.

[0025] The term "and / or" is a description of the association relationship between objects, indicating that three relationships can exist. For example, A and / or B means: A or B, or, A and B.

[0026] Example 1 This embodiment discloses a temperature distribution calculation method for a mixed gas isolating switch, wherein the mixed gas isolating switch is a SF6 / N2 mixed gas isolating switch, and in other embodiments, it may also be an isolating switch with other gas mixtures. Figure 1 As shown, the following steps are included: S1. Carry out three-dimensional proportional modeling and finite element meshing of the gas chamber of the mixed gas disconnector. The model built is an electromagnetic field-temperature field-fluid field coupling calculation model, and parameter assignment is performed for each material in the model; S2, electromagnetic field-temperature field coupling, first use the conductor AC impedance empirical formula under the influence of skin effect to calculate the conductor heating power, use the coaxial conductor magnetic field distribution empirical formula and Faraday's law of electromagnetic induction to calculate the shell heating power, then combine the law of conservation of energy in the conductor and shell, and calculate the solid temperature of the mixed gas isolating switch gas chamber through the heat transfer process inside the mixed gas isolating switch conductor and shell; S3, fluid field-temperature field coupling, firstly, according to the principle of fluid multi-component transmission, the physical properties of the mixed gas in the mixed gas isolating switch air chamber are combined, and then the fluid energy conservation equation, mass conservation equation and momentum conservation equation are combined to represent the convective heat transfer process inside the mixed gas, and the gas temperature of the mixed gas isolating switch air chamber is calculated based on the convective heat transfer process; determine the influence of the gas temperature of the mixed gas isolating switch air chamber on the solid temperature, and determine the final solid temperature of the isolating switch air chamber according to the influence; S4. Set up the various parts of the coupling calculation model Initial temperature at time, calculation time step, convergence criterion , let n's initial value be 1; S5, execute steps S2 and S3, calculate Solid temperature and gas temperature of the mixed gas isolating switch gas chamber at the moment; S6: Determine whether the difference between the current temperature of all parts and the previous temperature is less than the convergence criterion If yes, then read the calculation result of the solid temperature distribution. If not, update the material parameters according to the current temperature of each part, set n=n+1, and repeat step S5.

[0027] In this embodiment, the conductor heating power calculation formula is as follows: (1) (2) (3), Using the empirical formula of the magnetic field distribution of the coaxial conductor and Faraday's law of electromagnetic induction, the formula for calculating the shell heating power is: (4), in is the heating power of the conductor in Joules, is the effective value of the conductor current, is the AC impedance per unit length of the conductor, For its actual part, and are the inner and outer diameters of the hollow conductor, , is the angular frequency and , is the magnetic permeability of the conductor material (aluminum alloy in this embodiment), , , , are one type of zero-order Bessel function, one type of first-order Bessel function, two types of zero-order Bessel function, and two types of first-order Bessel function, respectively. is the temperature of the solid (conductor and shell) in the gas chamber of the mixed gas isolating switch, which is the unknown quantity to be determined. , The conductor material is at temperature 、 Resistivity at 20°C, is the temperature coefficient of resistivity of the conductor material, is the heat generation power of the shell circulation, and are the inner diameter and outer diameter of the shell respectively; the heat generation power of the conductor and the shell is used as a heat source excitation to participate in the calculation of the solid temperature of the gas chamber of the mixed gas disconnector.

[0028] Combined with the law of energy conservation in the conductor and shell, the heat transfer process inside the conductor and shell of the mixed gas disconnector can be expressed as: (5) (6) (7) (8) in: , , are the density, specific heat capacity and thermal conductivity of the conductor / shell, The heat generated by the conductor / shell itself per unit length; It is the heat transfer inside the solid material; It is the heat radiation heat exchange between the solid and the shell; is the Stefan Boltzmann constant; and They are the outer surface temperature of the conductor and the inner surface temperature of the shell, which are read during the iterative calculation process; and are the radiances of the outer surface of the conductor and the inner surface of the shell respectively; ▽ is the Laplace operator.

[0029] According to the principle of multi-component transmission of fluids, the physical properties of the mixed gas in the gas chamber of the mixed gas isolation switch are combined to obtain: (9) , in , , , They are the density, specific heat capacity at constant pressure, thermal conductivity, and dynamic viscosity of the mixed gas, respectively. , , , are the density, specific heat capacity at constant pressure, thermal conductivity, and dynamic viscosity of gas 1, , , , are the density, specific heat capacity at constant pressure, thermal conductivity, and dynamic viscosity of gas 2, , are the mass fractions of gas 1 and gas 2 in the mixed gas respectively; Combining the fluid energy conservation equation, mass conservation equation and momentum conservation equation, the convective heat transfer process inside the mixed gas can be expressed as: (10) (11) (12) Where: is the temperature of the mixed gas, which is the unknown quantity to be determined; ▽ is the Laplace operator; is the gas pressure of the mixed gas isolating switch gas chamber, is the acceleration due to gravity, and are the velocity vector and the identity matrix, respectively. is the density difference caused by thermal expansion of the gas, Represents matrix transpose.

[0030] Mixed gas temperature Temperature of solid materials The influence of is reflected on the interface between the two, satisfying the following interface boundary conditions: (13) Where: and are the outer surface temperature of the conductor and the inner surface temperature of the shell, and are the temperatures of the mixed gas in contact with the outer surface of the conductor and the inner surface of the shell, respectively. and are the normal vectors of the outer surface of the conductor and the inner surface of the shell, respectively. The above formula shows that at the interface between the mixed gas and the solid material, the gas temperature is equal to the solid temperature, and the heat flux density along the normal direction of the interface is equal.

[0031] In this embodiment, the moving contact and the stationary contact in the electromagnetic field-temperature field-fluid field coupling calculation model are set in a non-contact state, and a resistor film is set in the gap. The change of the contact resistance between the moving and stationary contacts is simulated by changing the resistance value of the resistor film. As reflected in the formula, when the resistance value changes, changes have occurred.

[0032] The method described in this embodiment is applied to a typical model of 220kV SF6 / N2 mixed gas GIS disconnector, such as Figure 2 As shown, it includes a housing 1, a pot-type insulator 3 and an insulating torsion bar 2 located in the housing 1, and two pot-type insulators 3 are connected by a moving contact 4 and a stationary contact 5. The total length of the air chamber of the disconnector is 1200 mm, the inner and outer diameters of the housing are 150 mm and 162 mm respectively, and the inner and outer diameters of the conductor are 64 mm and 70 mm respectively.

[0033] The temperature distribution during normal operation at rated current 3150A is as follows Figure 3 , 4 The highest temperature of the conductor is 37.3℃, which is located at the position where the moving and static contacts are plugged in, and the temperature of the rest of the conductor is around 35℃; due to the convection of the gas, the highest temperature on the shell surface appears at the top, which is 30.2℃, and the lowest temperature at the bottom of the shell is 28.7℃.

[0034] In particular, in order to simulate the poor contact between the moving and static contacts of the SF6 / N2 mixed gas disconnector, the moving contact and the static contact in the calculation model are set to a non-contact state (with a 1mm gap), and a resistance film 8 with a thickness of 1mm is set at the gap. The change of the contact resistance between the moving and static contacts is simulated by changing the resistance value of the resistance film 8. The schematic diagram of the contact 6, the contact finger 7 and the resistance film 8 is shown in Figure 5 shown.

[0035] When the contact resistance of the moving and static contacts of the SF6 / N2 mixed gas is 200 mΩ, the temperature distribution is as follows: Figure 6 As shown, the temperature at the joint of the moving and static contacts of the conductor has reached 68.6°C, and the temperature difference relative to the same position during normal operation is 31.3K; the highest temperature on the shell surface appears just above the moving and static contacts, which is 31.3°C, and the temperature difference is only 1.1K.

[0036] In particular, the curves of the maximum temperature of the conductor and shell surface changing with the contact resistance at different contact resistances are as follows: Figure 6As shown. When the temperature of the moving and static contacts of the SF6 / N2 mixed gas disconnector reaches 90°C, the maximum temperature of the shell surface is 32.7°C, and the temperature difference is 2.5K. Therefore, according to the power enterprise standard DL / T 664-2016 "Application Specification of Infrared Diagnosis of Live Equipment", it can be considered that when the operating current of the SF6 / N2 mixed gas disconnector is 3150A, "the shell surface temperature difference is greater than 2.5K" can be judged that there is a serious heating defect at the internal connection.

[0037] In addition, the operating conditions of the SF6 / N2 mixed gas disconnector can be set at will, which is conducive to scientific research and engineering simulation, and has good practical application value and promotion value.

[0038] Example 2 The present invention also discloses a temperature distribution calculation device for a mixed gas isolating switch, comprising: The three-dimensional modeling and assignment module is used to perform three-dimensional modeling and finite element meshing of the mixed gas disconnector chamber, and to assign parameters to each material in the model. The model built is an electromagnetic field-temperature field-fluid field coupling calculation model; The electromagnetic field-temperature field coupling module first calculates the conductor heating power using the empirical formula of the conductor AC impedance under the influence of the skin effect, and calculates the shell heating power using the empirical formula of the coaxial conductor magnetic field distribution and Faraday's law of electromagnetic induction. Then, combined with the law of conservation of energy in the conductor and the shell, the solid temperature of the mixed gas isolating switch gas chamber is calculated through the heat transfer process inside the conductor and the shell of the mixed gas isolating switch; The fluid field-temperature field coupling module first combines the physical properties of the mixed gas in the mixed gas isolating switch chamber according to the fluid multi-component transmission principle, and then combines the fluid energy conservation equation, mass conservation equation and momentum conservation equation to represent the convective heat transfer process inside the mixed gas. The gas temperature of the mixed gas isolating switch chamber is calculated based on the convective heat transfer process; the influence of the gas temperature of the mixed gas isolating switch chamber on the solid temperature is determined, and the final solid temperature of the isolating switch chamber is determined based on the influence; Initial value setting and calculation module, used to set various parts of the coupling calculation model Initial temperature at time, calculation time step, convergence criterion , set the initial value of n to 1; and trigger the electromagnetic field-temperature field coupling module and the fluid field-temperature field coupling module to calculate Solid temperature and gas temperature of the mixed gas isolating switch gas chamber at the moment; The judgment module is used to judge whether the difference between the current temperature of all parts and the previous temperature is less than the convergence criterion If yes, read the calculation result of solid temperature distribution. If not, update the material parameters according to the current temperature of each part, set n=n+1, trigger the electromagnetic field-temperature field coupling module and fluid field-temperature field coupling module for calculation.

[0039] Example 3 This embodiment discloses a temperature distribution calculation device for a mixed gas isolating switch, including a processor and a memory storing program instructions, wherein the processor is configured to execute the temperature distribution calculation method for a mixed gas isolating switch described in Example 1 when running the program instructions.

[0040] In addition, the logic instructions in the above-mentioned memory can be implemented in the form of software functional units and can be stored in a computer-readable storage medium when sold or used as an independent product.

[0041] The memory, as a computer-readable storage medium, can be used to store software programs and computer executable programs, such as program instructions / modules corresponding to the method in the embodiment of the present disclosure. The processor executes the function application and data processing by running the program instructions / modules stored in the memory, that is, the temperature distribution calculation method for the mixed gas isolation switch in the above-mentioned embodiment 1 is realized.

[0042] The memory may include a program storage area and a data storage area, wherein the program storage area may store an operating system and an application required for at least one function; the data storage area may store data created according to the use of the terminal device, etc. In addition, the memory may include a high-speed random access memory and may also include a non-volatile memory.

[0043] Example 4 This embodiment discloses a storage medium storing program instructions. When the program instructions are run, the temperature distribution calculation method for the mixed gas isolating switch described in Embodiment 1 is executed.

[0044] The computer-readable storage medium mentioned above may be a transient computer-readable storage medium or a non-transitory computer-readable storage medium.

[0045] The technical solution of the embodiment of the present disclosure can be embodied in the form of a software product, which is stored in a storage medium and includes one or more instructions for enabling a computer device (which may be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the method described in the embodiment of the present disclosure. The aforementioned storage medium may be a non-transient storage medium, including: a USB flash drive, a mobile hard disk, a read-only memory (ROM, Read-Only Memory), a random access memory (RAM, Random Access Memory), a disk or an optical disk, and other media that can store program codes, or a transient storage medium.

[0046] The above specific implementations are only specific cases of the present invention and are not intended to limit the present invention in other forms. Any technician familiar with the profession may use the above disclosed technical content to change or modify it into an equivalent implementation of equivalent changes. However, any simple modification, equivalent change and modification made to the above implementation according to the technical essence of the present invention without departing from the technical principle of the present invention shall fall within the patent protection scope of the present invention.

Claims

1. A temperature distribution calculation method for a mixed gas isolating switch, characterized in that: The following steps are involved: S1. Perform three-dimensional modeling and finite element meshing on the gas chamber of the mixed gas disconnector. The model is an electromagnetic field-temperature field-fluid field coupling calculation model, and parameters are assigned to each material in the model; S2, electromagnetic field-temperature field coupling, first use the conductor AC impedance empirical formula under the influence of skin effect to calculate the conductor heating power, use the coaxial conductor magnetic field distribution empirical formula and Faraday's law of electromagnetic induction to calculate the shell heating power, then combine the law of conservation of energy in the conductor and shell, and calculate the solid temperature of the mixed gas isolating switch gas chamber through the heat transfer process inside the mixed gas isolating switch conductor and shell; S3, fluid field-temperature field coupling, firstly, according to the principle of fluid multi-component transmission, the physical properties of the mixed gas in the mixed gas isolating switch air chamber are combined, and then the fluid energy conservation equation, mass conservation equation and momentum conservation equation are combined to represent the convective heat transfer process inside the mixed gas, and the gas temperature of the mixed gas isolating switch air chamber is calculated based on the convective heat transfer process; determine the influence of the gas temperature of the mixed gas isolating switch air chamber on the solid temperature, and determine the final solid temperature of the isolating switch air chamber according to the influence; S4. Set up the various parts of the coupling calculation model Initial temperature at time, calculation time step, convergence criterion , let n's initial value be 1; S5, execute steps S2 and S3, calculate Solid temperature and gas temperature of the mixed gas isolating switch gas chamber at the moment; S6: Determine whether the difference between the current temperature of all parts and the previous temperature is less than the convergence criterion If yes, then read the calculation result of the solid temperature distribution. If not, update the material parameters according to the current temperature of each part, set n=n+1, and repeat step S5.

2. The temperature distribution calculation method for a mixed gas isolating switch according to claim 1, characterized in that: Using the empirical formula of the conductor AC impedance under the influence of the skin effect, the formula for calculating the conductor heating power is: (1)， (2)， （3）， Using the empirical formula of the magnetic field distribution of the coaxial conductor and Faraday's law of electromagnetic induction, the formula for calculating the shell heating power is: （4）， in is the heating power of the conductor in Joules, is the effective value of the conductor current, is the AC impedance per unit length of the conductor, For its actual part, d 1 and d 2 are the inner and outer diameters of the hollow conductor, , is the angular frequency, is the magnetic permeability of the conductor material, I 0. I 1. K 0. K 1 represents a type of zero-order Bessel function, a type of first-order Bessel function, a type of second-order zero-order Bessel function, and a type of second-order Bessel function. T m is the temperature of the solid in the gas chamber of the mixed gas isolating switch, which is the unknown quantity to be determined. , The conductor material is at temperature T m 、 Resistivity at 20°C, is the temperature coefficient of resistivity of the conductor material, is the heat generation power of the shell circulation, D 1 and D 2 are the inner diameter and outer diameter of the shell respectively; the heat generation power of the conductor and the shell is used as a heat source to excite the solid temperature calculation of the gas chamber of the mixed gas disconnector; Combined with the law of energy conservation in the conductor and shell, the heat transfer process inside the conductor and shell of the mixed gas disconnector can be expressed as: (5)， (6)， (7)， (8)， in: , , are the density, specific heat capacity and thermal conductivity of the conductor / shell, The heat generated by the conductor / shell itself per unit length; It is the heat transfer inside the solid material; It is the heat radiation heat exchange between the solid and the shell; is the Stefan Boltzmann constant; and They are the outer surface temperature of the conductor and the inner surface temperature of the shell, which are read during the iterative calculation process; and are the radiances of the outer surface of the conductor and the inner surface of the shell respectively; ▽ is the Laplace operator.

3. The temperature distribution calculation method for a mixed gas isolating switch according to claim 2, characterized in that: According to the principle of multi-component transmission of fluids, the physical properties of the mixed gas in the gas chamber of the mixed gas isolation switch are combined to obtain: (9) ， in , , , They are the density, specific heat capacity at constant pressure, thermal conductivity, and dynamic viscosity of the mixed gas, respectively. , , , are the density, specific heat capacity at constant pressure, thermal conductivity, and dynamic viscosity of gas 1, , , , are the density, specific heat capacity at constant pressure, thermal conductivity, and dynamic viscosity of gas 2, , are the mass fractions of gas 1 and gas 2 in the mixed gas respectively; Combining the fluid energy conservation equation, mass conservation equation and momentum conservation equation, the convective heat transfer process inside the mixed gas can be expressed as: (10)， (11)， (12)， Where: is the temperature of the mixed gas, which is the unknown quantity to be determined; ▽ is the Laplace operator; is the gas pressure of the mixed gas isolating switch gas chamber, is the acceleration due to gravity, and are the velocity vector and the identity matrix, respectively. is the density difference caused by thermal expansion of the gas, Represents matrix transpose.

4. The temperature distribution calculation method for a mixed gas isolating switch according to claim 3, characterized in that: Mixed gas temperature Temperature of solid materials The influence of is reflected on the interface between the two, satisfying the following interface boundary conditions: (13)， Where: and are the outer surface temperature of the conductor and the inner surface temperature of the shell, and are the temperatures of the mixed gas in contact with the outer surface of the conductor and the inner surface of the shell, respectively. and are the normal vectors of the outer surface of the conductor and the inner surface of the shell, respectively.

5. The temperature distribution calculation method for a mixed gas isolating switch according to claim 1, characterized in that: The moving contact and the static contact in the electromagnetic field-temperature field-fluid field coupling calculation model are set in a non-contact state, and a resistor film is set in the gap. The change of the contact resistance between the moving and static contacts is simulated by changing the resistance value of the resistor film.

6. The temperature distribution calculation method for a mixed gas isolating switch according to claim 1, characterized in that: The mixed gas isolating switch is a SF6 / N2 mixed gas isolating switch.

7. The temperature distribution calculation method for a mixed gas isolating switch according to claim 1, characterized in that: Carry out three-dimensional proportional modeling of the mixed gas isolating switch chamber.

8. A temperature distribution calculation device for a mixed gas isolating switch, characterized in that: include: The three-dimensional modeling and assignment module is used to perform three-dimensional modeling and finite element meshing of the mixed gas disconnector chamber, and to assign parameters to each material in the model. The model built is an electromagnetic field-temperature field-fluid field coupling calculation model; The electromagnetic field-temperature field coupling module first calculates the conductor heating power using the empirical formula of the conductor AC impedance under the influence of the skin effect, and calculates the shell heating power using the empirical formula of the coaxial conductor magnetic field distribution and Faraday's law of electromagnetic induction. Then, combined with the law of conservation of energy in the conductor and the shell, the solid temperature of the mixed gas isolating switch gas chamber is calculated through the heat transfer process inside the conductor and the shell of the mixed gas isolating switch; The fluid field-temperature field coupling module first combines the physical properties of the mixed gas in the mixed gas isolating switch chamber according to the fluid multi-component transmission principle, and then combines the fluid energy conservation equation, mass conservation equation and momentum conservation equation to represent the convective heat transfer process inside the mixed gas. The gas temperature of the mixed gas isolating switch chamber is calculated based on the convective heat transfer process; the influence of the gas temperature of the mixed gas isolating switch chamber on the solid temperature is determined, and the final solid temperature of the isolating switch chamber is determined based on the influence; Initial value setting and calculation module, used to set various parts of the coupling calculation model Initial temperature at time, calculation time step, convergence criterion , let n's initial value be 1; And trigger the electromagnetic field-temperature field coupling module and the fluid field-temperature field coupling module to calculate Solid temperature and gas temperature of the mixed gas isolating switch gas chamber at the moment; The judgment module is used to judge whether the difference between the current temperature of all parts and the previous temperature is less than the convergence criterion If yes, read the calculation result of solid temperature distribution. If not, update the material parameters according to the current temperature of each part, set n=n+1, trigger the electromagnetic field-temperature field coupling module and fluid field-temperature field coupling module for calculation.

9. A temperature distribution calculation device for a mixed gas isolating switch, comprising a processor and a memory storing program instructions, characterized in that: The processor is configured to execute the temperature distribution calculation method for a mixed gas isolation switch according to any one of claims 1 to 7 when running the program instructions.

10. A storage medium storing program instructions, characterized in that: When the program instructions are executed, the temperature distribution calculation method for a mixed gas disconnector according to any one of claims 1 to 7 is executed.

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