Parameter calculation method and device for influence of ablation vapor on switch arc combustion characteristics

Abstract

The application relates to a parameter calculation method, device and equipment for the influence of ablation vapor on the arc combustion characteristics of a switch, the method comprising the following steps: obtaining arc parameter data of a switch device; calculating the evaporation rate and mass fraction of each species according to the arc parameter data; calculating the Stefan flow rate according to the evaporation rate and mass fraction of all species of the switch device; coupling the evaporation rate and the Stefan flow rate through a boundary condition to construct a magnetohydrodynamic model; and updating the thermodynamic parameters of the magnetohydrodynamic model according to the mass fraction of all species. The method constructs a magnetohydrodynamic model through the evaporation rate and the Stefan flow rate, adopts the mass fraction of each species to update the thermodynamic parameters of the magnetohydrodynamic model under the arc plasma condition of a mixed gas atmosphere composition, and analyzes the influence of ablation vapor on the arc extinguishing chamber temperature and pressure distribution, arc voltage and other arc combustion characteristics of the switch device through the thermodynamic parameters.

Description

Technical Field

[0001] This application relates to the field of circuit combustion technology, and in particular to a method, apparatus and equipment for calculating parameters of the influence of ablation steam on the combustion characteristics of switch arcs. Background Technology

[0002] With the development of technology, the power grid structure is becoming increasingly complex, with AC and DC interactions, and the grid capacity is constantly increasing. Problems such as excessive short-circuit current and the risk of large-scale power outages seriously threaten the safe and stable operation of the power system. The short-circuit current withstand capability of the existing 500kV main grid can no longer meet the needs of power grid development, and there is an urgent need to develop large-capacity, highly reliable switchgear that can be used for both old substation renovation and new construction projects.

[0003] In the entire breaking process of circuit breakers in power systems, the study of the arcing stage characteristics of circuit breakers is fundamental to the analysis of arc and airflow field characteristics, and also has a significant impact on the post-arc breaking process. The metal vapor from the circuit breaker significantly affects the physical properties of the arc plasma mixture, while the polymer vapor emitted from the ablation of polymers on the circuit breaker walls plays a role in the arc movement and morphological development. If the high-voltage circuit breaker casing is composed of polymers that easily vaporize at high temperatures, the generation of a large amount of polymer vapor will greatly increase local pressure, alter the flow field, and thus accelerate arc movement and arc demise. Stefan flow is internally generated and can occur without any external flow application. As polymer vapor continuously diffuses from the reaction surface to the surrounding gas, this diffusion leads to a net mass transfer, a convective process, which is crucial when strong evaporation occurs in a thermal environment. Therefore, the Stefan flow velocity can be used to characterize the impact of metal vapor or polymer vapor entering the circuit breaker arc plasma and its effect on changes in local spatial flow velocity. Summary of the Invention

[0004] This application provides a method, apparatus, and equipment for calculating parameters of the influence of ablation steam on the arc combustion characteristics of a switch, which solves the technical problem that there is no existing method for evaluating the influence of arc combustion characteristics of circuit breakers.

[0005] To achieve the above objectives, the embodiments of this application provide the following technical solutions:

[0006] On the one hand, a method for calculating the parameters of the effect of ablation steam on the combustion characteristics of a switching arc is provided, including the following steps:

[0007] Acquire the arc parameter data of the switching device, which includes the diffusion coefficient of vapor, flow field velocity, equilibrium vapor pressure, Boltzmann constant, single atom mass of electrode material, surface temperature of electrode, and initial total pressure, source term and density of each species;

[0008] Based on the arc parameter data, the evaporation rate and mass fraction of each species in the switching device are calculated; and based on the evaporation rate and mass fraction of all species in the switching device, the Stefan flow rate of the switching device electrode and its cavity wall surface is calculated.

[0009] The evaporation rate and the Stefan flow velocity are coupled through boundary conditions to construct a magnetohydrodynamic model of the switching device;

[0010] The thermodynamic parameters of the magnetohydrodynamic model are updated based on the mass fraction of all species in the switching device; the thermodynamic parameters include the specific heat, density, viscosity, thermal conductivity, and electrical conductivity of the switching device under species disturbance.

[0011] The boundary conditions are as follows: , For Stefan flow rate, Y i Let be the quality score of the i-th species of the switching device. Let be the evaporation rate of the i-th species in the switching equipment. Let be the density of the i-th species.

[0012] Preferably, the method for calculating the parameters affecting the combustion characteristics of the ablation steam on the switching arc includes:

[0013] The mapping relationship of the switching device is obtained, and the arc root tilt angle and arc center curvature radius of the switching device are calculated based on the Stefan flow rate, the mass fraction of each species and the mapping relationship using the arc spatiotemporal distribution.

[0014] The mapping relationships include the mapping between the flow field of the switching device and the species mass fraction, the mapping between the flow field and the arc root radius, and the mapping between the arc length and the current.

[0015] The expression for the spatiotemporal distribution of the electric arc is:

[0016]

[0017]

[0018] In the formula, The angle of inclination of the arc root of the switchgear. For Stefan flow rate, Y i Let f1 be the mass fraction of the i-th species in the switching device, r be the arc root radius, f1 be the mapping relationship between the flow field and the species mass fraction, f2 be the mapping relationship between the flow field and the arc root radius, F be the mapping relationship between the arc length and the current, l be the arc column length of the switching device, j be the current density of the switching device, A be a coefficient, and R be the arc center curvature radius of the switching device.

[0019] Preferably, calculating the evaporation rate and mass fraction of each species in the switching equipment based on the arc parameter data includes: calculating the evaporation rate and mass fraction of each species in the switching equipment using the Langmuir formula and the species transport equation based on the arc parameter data; the Langmuir formula is:

[0020]

[0021]

[0022] The species transport equation is as follows:

[0023]

[0024] In the formula, P is the atomic evaporation rate. eq To balance the vapor pressure, m0 is the single-atom mass of the electrode material, k B Where P is Boltzmann's constant, T is the surface temperature of the electrode, and P is the surface temperature of the electrode. i Let be the partial vapor pressure of the i-th species. Y represents the evaporation rate of the i-th species in the switching equipment. i Let S be the quality fraction of the i-th species in the switching device. i Let i be the source term for the i-th species. Let be the density of the i-th species. Let be the velocity of the flow field in the switchgear, D be the diffusion coefficient of the steam in the switchgear, and t be time.

[0025] Preferably, calculating the Stefan flow rate of the switch device electrode and its cavity wall surface based on the evaporation rate and mass fraction of all species in the switch device includes: calculating the Stefan flow rate of the switch device electrode and its cavity wall surface using a flow rate calculation formula based on the evaporation rate and mass fraction of all species in the switch device; the flow rate calculation formula is:

[0026]

[0027] In the formula, For Stefan flow rate, Y i Let be the mass fraction of the i-th species in the switchgear, D be the diffusion coefficient of the vapor in the switchgear, and n be the total number of species in the switchgear.

[0028] Preferably, updating the thermodynamic parameters of the magnetohydrodynamic (MHD) model based on the mass fraction of all species in the switching equipment includes: calculating the specific heat, density, viscosity, thermal conductivity, and electrical conductivity of the switching equipment under species interference using the calculation formula of the MHD model based on the mass fraction of all species in the switching equipment; the calculation formula of the MHD model is as follows:

[0029]

[0030]

[0031]

[0032]

[0033]

[0034] In the formula, n is the total number of switchgear species, C pmix For the specific heat of switching equipment under species disturbance, The viscosity of switching devices based on species interference, The viscosity of switching devices based on species interference, k represents the conductivity of the switching equipment under species interference. mix C represents the thermal conductivity of switching equipment under species interference. pi Y is the isobaric specific heat of the i-th species. i Let be the quality score of the i-th species of the switching device. Let be the density of the i-th species. Let be the viscosity of the i-th species. Let M be the electrical conductivity of the i-th species. i Let k be the molar mass of the i-th species. i Let be the thermal conductivity of the i-th species.

[0035] On the other hand, a parameter calculation device for the influence of ablation steam on the combustion characteristics of a switching arc is provided, including a data acquisition module, a calculation module, a model building module and an update calculation module;

[0036] The data acquisition module is used to acquire the arc parameter data of the switching equipment. The arc parameter data includes the diffusion coefficient of vapor, the velocity of the flow field, the equilibrium vapor pressure, the Boltzmann constant, the single-atom mass of the electrode material, the surface temperature of the electrode, and the initial total pressure, source term, and density of each species.

[0037] The calculation module is used to calculate the evaporation rate and mass fraction of each species in the switching device based on the arc parameter data; and to calculate the Stefan flow rate of the switching device electrode and its cavity wall surface based on the evaporation rate and mass fraction of all species in the switching device.

[0038] The model building module is used to couple the evaporation rate and the Stefan flow velocity through boundary conditions to build a magnetohydrodynamic model of the switching device.

[0039] The update calculation module is used to update the thermodynamic parameters of the magnetohydrodynamic model based on the mass fraction of all species in the switching device; the thermodynamic parameters include the specific heat, density, viscosity, thermal conductivity, and electrical conductivity of the switching device under species disturbance.

[0040] The boundary conditions are as follows: , For Stefan flow rate, Y i Let be the quality score of the i-th species of the switching device. Let be the evaporation rate of the i-th species in the switching equipment. Let be the density of the i-th species.

[0041] Preferably, the parameter calculation device for the influence of ablation steam on the combustion characteristics of the switch arc includes an arc parameter calculation module. The arc parameter calculation module is used to obtain the mapping relationship of the switch equipment, and calculate the arc root tilt angle and arc center curvature radius of the switch equipment based on the Stefan flow rate, the mass fraction of each species and the mapping relationship using the arc spatiotemporal distribution.

[0042] The mapping relationships include the mapping between the flow field of the switching device and the species mass fraction, the mapping between the flow field and the arc root radius, and the mapping between the arc length and the current.

[0043] The expression for the spatiotemporal distribution of the electric arc is:

[0044]

[0045]

[0046] In the formula, The angle of inclination of the arc root of the switchgear. For Stefan flow rate, Y i Let f1 be the mass fraction of the i-th species in the switching device, r be the arc root radius, f1 be the mapping relationship between the flow field and the species mass fraction, f2 be the mapping relationship between the flow field and the arc root radius, F be the mapping relationship between the arc length and the current, l be the arc column length of the switching device, j be the current density of the switching device, A be a coefficient, and R be the arc center curvature radius of the switching device.

[0047] Preferably, the update calculation module is further configured to calculate the specific heat, density, viscosity, thermal conductivity, and electrical conductivity of the switchgear under species interference based on the mass fraction of all species in the switchgear using the calculation formula of the magnetohydrodynamic model; the calculation formula of the magnetohydrodynamic model is:

[0048]

[0049]

[0050]

[0051]

[0052]

[0053] In the formula, n is the total number of switchgear species, C pmix For the specific heat of switching equipment under species disturbance, The viscosity of switching devices based on species interference, The viscosity of switching devices based on species interference, k represents the conductivity of the switching equipment under species interference. mix C represents the thermal conductivity of switching equipment under species interference. pi Y is the isobaric specific heat of the i-th species. i Let be the quality score of the i-th species of the switching device. Let be the density of the i-th species. Let be the viscosity of the i-th species. Let M be the electrical conductivity of the i-th species. i Let k be the molar mass of the i-th species. i Let be the thermal conductivity of the i-th species.

[0054] Preferably, the calculation module is further configured to calculate the evaporation rate and mass fraction of each species in the switching device using the Langmuir formula and the species transport equation based on the arc parameter data; and to calculate the Stefan velocity of the switching device electrodes and their cavity wall surfaces using a flow rate calculation formula based on the evaporation rate and mass fraction of all species in the switching device; the Langmuir formula is:

[0055]

[0056]

[0057] The species transport equation is as follows:

[0058]

[0059] The formula for calculating the flow velocity is:

[0060]

[0061] In the formula, For Stefan flow rate, Y i Let be the quality score of the i-th species of the switching equipment, and n be the total number of species of the switching equipment; P is the atomic evaporation rate. eq To balance the vapor pressure, m0 is the single-atom mass of the electrode material, k B Where P is Boltzmann's constant, T is the surface temperature of the electrode, and P is the surface temperature of the electrode. i Let be the partial vapor pressure of the i-th species. Let S be the evaporation rate of the i-th species in the switching equipment. i Let i be the source term for the i-th species. Let be the density of the i-th species. Let be the velocity of the flow field in the switchgear, D be the diffusion coefficient of the steam in the switchgear, and t be time.

[0062] On the other hand, a terminal device is provided, including a processor and a memory;

[0063] The memory is used to store program code and transmit the program code to the processor;

[0064] The processor is configured to execute the parameter calculation method for the influence of ablation steam on the combustion characteristics of the switching arc according to the instructions in the program code.

[0065] As can be seen from the above technical solutions, the embodiments of this application have the following advantages: the method, apparatus, and equipment for calculating the parameters of the influence of ablation steam on the combustion characteristics of the switching arc, the method includes acquiring arc parameter data of the switching device; calculating the evaporation rate and mass fraction of each species in the switching device based on the arc parameter data; calculating the Stefan velocity of the switching device electrode and its cavity wall surface based on the evaporation rate and mass fraction of all species in the switching device; coupling the evaporation rate and Stefan velocity through boundary conditions to construct a magnetohydrodynamic model of the switching device; and updating the thermodynamic parameters of the magnetohydrodynamic model based on the mass fraction of all species in the switching device. This method for calculating the parameters affecting the arc combustion characteristics of switchgear uses arc parameter data from the switchgear to calculate the evaporation rate and Stefan velocity to construct a magnetohydrodynamic (MHD) model. Then, based on the arc parameter data, the mass fraction of each species in the switchgear is calculated to update the thermodynamic parameters of the MHD model. This allows for obtaining thermodynamic parameters under mixed atmosphere and arc plasma conditions. The thermodynamic parameters can be used to analyze the impact of ablation steam on the arc-extinguishing chamber temperature and pressure distribution, as well as the arc voltage and other arc combustion characteristics of the switchgear, thus solving the technical problem of the lack of existing methods for assessing the impact on the arc combustion characteristics of circuit breakers. Attached Figure Description

[0066] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0067] Figure 1 This is a flowchart illustrating the steps of the parameter calculation method for the effect of ablation steam on the combustion characteristics of a switch arc as described in an embodiment of this application.

[0068] Figure 2 This is a flowchart illustrating the framework of a parameter calculation device for the influence of ablation steam on the combustion characteristics of a switching arc, according to an embodiment of this application. Detailed Implementation

[0069] To make the inventive objectives, features, and advantages of this application more apparent and understandable, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described below are only some embodiments of this application, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0070] In the description of the embodiments of this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0071] In the embodiments of this application, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; 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; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0072] This application provides a method, apparatus, and device for calculating the parameters affecting the arc combustion characteristics of ablation steam on a switchgear. It can calculate the impact of ablation steam on the arc-extinguishing chamber temperature and pressure distribution, as well as the arc voltage, of the switchgear based on thermodynamic parameters such as specific heat, density, viscosity, thermal conductivity, and electrical conductivity under species interference. This addresses the technical problem of the lack of existing methods for evaluating the impact on the arc combustion characteristics of circuit breakers. In this embodiment, the switchgear can be a circuit breaker or a fuse. This embodiment uses a circuit breaker as an example for illustration.

[0073] Example 1:

[0074] Figure 1 This is a flowchart illustrating the steps of the parameter calculation method for the influence of ablation steam on the combustion characteristics of a switch arc, as described in an embodiment of this application.

[0075] like Figure 1 As shown in the figure, this application provides a method for calculating the parameters of the effect of ablation steam on the combustion characteristics of a switching arc, including the following steps:

[0076] S1. Obtain the arc parameter data of the switching equipment. The arc parameter data includes the diffusion coefficient of vapor, the velocity of the flow field, the equilibrium vapor pressure, the Boltzmann constant, the single-atom mass of the electrode material, the surface temperature of the electrode, and the initial total pressure, source term, and density of each species.

[0077] It should be noted that step S1 involves acquiring arc parameter data of the switching equipment (circuit breaker) to provide data for subsequent analysis of the thermodynamic parameters of the switching equipment under arc plasma conditions involving ablation vapor mixture. In this embodiment, the transport process of the species in the switching equipment is determined based on different ablation materials. The species can be copper vapor generated during the ablation of the copper electrodes of the circuit breaker during use, or it can be an insulating gas in the circuit breaker cavity, such as SF6, or other insulating gases.

[0078] S2. Based on the arc parameter data, calculate the evaporation rate and mass fraction of each species in the switching device; and based on the evaporation rate and mass fraction of all species in the switching device, calculate the Stefan flow rate of the switching device electrode and its cavity wall surface.

[0079] It should be noted that in step S2, the evaporation rate of the switch device in the vaporization process of the metal species is first calculated based on the arc parameter data of the switch device, and the mass fraction of each species in the switch device is also calculated based on the arc parameter data of the switch device. Then, based on the calculated evaporation rate, mass fraction and vapor diffusion coefficient of all species, the Stefan flow rate of the switch device electrode and its cavity wall surface is calculated.

[0080] S3. The evaporation rate and Stefan velocity are coupled through boundary conditions to construct a magnetohydrodynamic model of the switching device. The boundary conditions are: , For Stefan flow rate, Y i Let be the quality score of the i-th species of the switching device. Let be the evaporation rate of the i-th species in the switching equipment. Let be the density of the i-th species.

[0081] It should be noted that in step S3, a magnetohydrodynamic (MHD) model of the switchgear is constructed in ANSYS software using the magnetohydrodynamic equations (mass, momentum, and energy conservation equations) and electromagnetic field equations (Biot-Savart law), based on the switchgear's switching structure, parameters, and boundary conditions. This MHD model includes an ablation model for the Stefan velocity, which can evaluate the impact of ablation vapor on the spatiotemporal distribution of the electric arc during the arc combustion process.

[0082] S4. Update the thermodynamic parameters of the magnetohydrodynamic model based on the mass fraction of all species in the switching equipment; the thermodynamic parameters include the specific heat, density, viscosity, thermal conductivity and electrical conductivity of the switching equipment under species disturbance.

[0083] It should be noted that in step S4, the thermodynamic parameters of the magnetohydrodynamic model are updated based on the mass fraction of each species obtained in step S2. The method for calculating the parameter effects of ablation steam on the arc combustion characteristics of the switching device can analyze the influence of ablation steam on the thermodynamic parameters of the arc plasma based on thermodynamic parameters. The metal vapor brought by the ablation electrode will change the physical properties of the insulating gas during the arc combustion process. For example, when the thermal conductivity changes, the temperature distribution of the arc will change, and the temperature gradient may be larger or smaller. Changes in conductivity will directly affect the voltage distribution of the circuit breaker. Changes in specific heat may lead to higher or lower arc temperatures for the same amount of energy input. Therefore, by using the mass fraction of each arc plasma species in the switching device, the thermodynamic parameters of the arc plasma, including the Stefan velocity, are obtained from the magnetohydrodynamic model under the mixed atmosphere composition. Based on these thermodynamic parameters, the influence of ablation steam on the arc-extinguishing chamber temperature and pressure distribution, as well as the arc voltage and other arc combustion characteristics, is analyzed.

[0084] This application provides a parameter calculation method for the influence of ablation steam on the arc combustion characteristics of a switchgear. The method includes acquiring arc parameter data of the switchgear; calculating the evaporation rate and mass fraction of each species in the switchgear based on the arc parameter data; calculating the Stefan velocity of the switchgear electrodes and their cavity wall surfaces based on the evaporation rate and mass fraction of all species in the switchgear; coupling the evaporation rate and Stefan velocity through boundary conditions to construct a magnetohydrodynamic (MHD) model of the switchgear; and updating the thermodynamic parameters of the MHD model based on the mass fraction of all species in the switchgear. This parameter calculation method for the influence of ablation steam on the arc combustion characteristics of a switchgear uses the arc parameter data of the switchgear to calculate the evaporation rate and Stefan velocity to construct a MHD model. Then, based on the arc parameter data, it calculates the mass fraction of each species in the switchgear to update the thermodynamic parameters of the MHD model. This achieves the acquisition of thermodynamic parameters under arc plasma conditions with mixed atmosphere composition. It enables the analysis of the influence of ablation steam on the arc characteristics of the switchgear, such as the temperature and pressure distribution of the arc extinguishing chamber and the arc voltage, through thermodynamic parameters, thus solving the technical problem of the lack of existing methods for evaluating the influence of ablation steam on the arc combustion characteristics of circuit breakers.

[0085] It should be noted that the parameter calculation method for the influence of ablation steam on the combustion characteristics of the switching arc was realized by simulating the metal steam convection process through the magnetohydrodynamic model of Stefan flow velocity.

[0086] In one embodiment of this application, the method for calculating the parameters affecting the ablation steam on the combustion characteristics of the switching arc includes:

[0087] The mapping relationship of the switching equipment is obtained. Based on the Stefan flow rate, the mass fraction of each species and the mapping relationship, the arc root inclination angle and the arc center curvature radius of the switching equipment are calculated using the arc spatiotemporal distribution.

[0088] Among them, the mapping relationships include the mapping between the flow field of the switching equipment and the species mass fraction, the mapping between the flow field and the arc root radius, and the mapping between the arc length and the current;

[0089] The expression for the spatiotemporal distribution of the electric arc is:

[0090]

[0091]

[0092] In the formula, The angle of inclination of the arc root of the switchgear. For Stefan flow rate, Y i Let f1 be the mass fraction of the i-th species in the switching device, r be the arc root radius, f1 be the mapping relationship between the flow field and the species mass fraction, f2 be the mapping relationship between the flow field and the arc root radius, F be the mapping relationship between the arc length and the current, l be the arc column length of the switching device, j be the current density of the switching device, A be a coefficient, and R be the arc center curvature radius of the switching device.

[0093] It should be noted that the parameter calculation method for the influence of ablation steam on the combustion characteristics of the switch arc is to calculate the arc root inclination angle and arc center curvature radius by realizing the influence of arc spatiotemporal distribution on the arc shape and spatial distribution of the switch equipment. Through the arc root inclination angle and arc center curvature radius, the principle support for the optimization of the arc extinguishing chamber structure of the switch equipment is provided, which has important reference significance for the design optimization of the arc extinguishing chamber structure of the switch equipment.

[0094] In one embodiment of this application, calculating the evaporation rate and mass fraction of each species in the switching device based on arc parameter data includes: calculating the evaporation rate and mass fraction of each species in the switching device using the Langmuir formula and the species transport equation based on the arc parameter data; the Langmuir formula is:

[0095]

[0096]

[0097] The species transport equation is:

[0098]

[0099] In the formula, P is the atomic evaporation rate. eqTo balance the vapor pressure, m0 is the single-atom mass of the electrode material, k B Where P is Boltzmann's constant, T is the surface temperature of the electrode, and P is the surface temperature of the electrode. i Let be the partial vapor pressure of the i-th species. Y represents the evaporation rate of the i-th species in the switching equipment. i Let S be the quality fraction of the i-th species in the switching device. i Let i be the source term for the i-th species. Let be the density of the i-th species. Let be the velocity of the flow field in the switchgear, D be the diffusion coefficient of the steam in the switchgear, and t be time.

[0100] It should be noted that the Langmuir formula explains the ratio of cooling density caused by electrode evaporation in switching devices to cooling density caused by thermionic emission. The velocity in the flow field of a switching device refers to the velocity under the law of conservation of fluid momentum.

[0101] In one embodiment of this application, calculating the Stefan flow rate of the switch electrode and its cavity wall surface based on the evaporation rate and mass fraction of all species in the switch device includes: calculating the Stefan flow rate of the switch electrode and its cavity wall surface using a flow rate calculation formula based on the evaporation rate and mass fraction of all species in the switch device; the flow rate calculation formula is:

[0102]

[0103] In the formula, For Stefan flow rate, Y i Let be the mass fraction of the i-th species in the switchgear, D be the diffusion coefficient of the vapor in the switchgear, and n be the total number of species in the switchgear.

[0104] It should be noted that the Stefan velocity refers to the evaporation velocity of metal vapor at the edge of the arc. The parameter calculation method for the influence of this ablation vapor on the combustion characteristics of the switching arc can be achieved by changing the flow field of the switching equipment through the Stefan velocity, thereby affecting the arc morphology and spatial distribution of the switching equipment.

[0105] In one embodiment of this application, updating the thermodynamic parameters of the magnetohydrodynamic (MHD) model based on the mass fraction of all species in the switching device includes: calculating the specific heat, density, viscosity, thermal conductivity, and electrical conductivity of the switching device under species interference using the calculation formula of the MHD model based on the mass fraction of all species in the switching device; the calculation formula of the MHD model is as follows:

[0106]

[0107]

[0108]

[0109]

[0110]

[0111] In the formula, n is the total number of switchgear species, C pmix For the specific heat of switching equipment under species disturbance, The viscosity of switching devices based on species interference, The viscosity of switching devices based on species interference, k represents the conductivity of the switching equipment under species interference. mix C represents the thermal conductivity of switching equipment under species interference. pi Y is the isobaric specific heat of the i-th species. i Let be the quality score of the i-th species of the switching device. Let be the density of the i-th species. Let be the viscosity of the i-th species. Let M be the electrical conductivity of the i-th species. i Let k be the molar mass of the i-th species. i Let be the thermal conductivity of the i-th species.

[0112] It should be noted that two species are used as case studies to illustrate the calculation of specific heat, density, viscosity, thermal conductivity, and electrical conductivity of the switchgear under species interference, based on the mass fraction of all species in the switchgear and using the calculation formula of the magnetohydrodynamic model. The calculations are as follows:

[0113]

[0114]

[0115]

[0116]

[0117] .

[0118] Example 2:

[0119] Figure 2 This is a flowchart illustrating the framework of the parameter calculation device for the influence of ablation steam on the combustion characteristics of a switch arc, as described in an embodiment of this application.

[0120] like Figure 2As shown, this application provides a parameter calculation device for the influence of ablation steam on the combustion characteristics of a switching arc, including a data acquisition module 10, a calculation module 20, a model building module 30, and an update calculation module 40;

[0121] The data acquisition module 10 is used to acquire the arc parameter data of the switching equipment. The arc parameter data includes the diffusion coefficient of vapor, the velocity of the flow field, the equilibrium vapor pressure, the Boltzmann constant, the single atom mass of the electrode material, the surface temperature of the electrode, and the initial total pressure, source term, and density of each species.

[0122] The calculation module 20 is used to calculate the evaporation rate and mass fraction of each species in the switching device based on the arc parameter data; and to calculate the Stefan flow rate of the switching device electrode and its cavity wall surface based on the evaporation rate and mass fraction of all species in the switching device.

[0123] Model building module 30 is used to couple the evaporation rate and Stefan velocity through boundary conditions to build a magnetohydrodynamic model of the switching device;

[0124] The calculation module 40 is updated to update the thermodynamic parameters of the magnetohydrodynamic model based on the mass fraction of all species in the switching device. The thermodynamic parameters include the specific heat, density, viscosity, thermal conductivity, and electrical conductivity of the switching device under species interference.

[0125] The boundary conditions are as follows: , For Stefan flow rate, Y i Let be the quality score of the i-th species of the switching device. Let be the evaporation rate of the i-th species in the switching equipment. Let be the density of the i-th species.

[0126] In this embodiment of the application, the parameter calculation device for the influence of ablation steam on the combustion characteristics of the switch arc includes an arc parameter calculation module. The arc parameter calculation module is used to obtain the mapping relationship of the switch equipment. Based on the Stefan flow rate, the mass fraction of each species and the mapping relationship, the arc spatiotemporal distribution is used to calculate the arc root tilt angle and arc center curvature radius of the switch equipment.

[0127] Among them, the mapping relationships include the mapping between the flow field of the switching equipment and the species mass fraction, the mapping between the flow field and the arc root radius, and the mapping between the arc length and the current;

[0128] The expression for the spatiotemporal distribution of the electric arc is:

[0129]

[0130]

[0131] In the formula, The angle of inclination of the arc root of the switchgear. For Stefan flow rate, Y i Let f1 be the mass fraction of the i-th species in the switching device, r be the arc root radius, f1 be the mapping relationship between the flow field and the species mass fraction, f2 be the mapping relationship between the flow field and the arc root radius, F be the mapping relationship between the arc length and the current, l be the arc column length of the switching device, j be the current density of the switching device, A be a coefficient, and R be the arc center curvature radius of the switching device.

[0132] In this embodiment, the update calculation module 40 is further configured to calculate the specific heat, density, viscosity, thermal conductivity, and electrical conductivity of the switchgear under species interference based on the mass fraction of all species in the switchgear using the calculation formula of the magnetohydrodynamic model; the calculation formula of the magnetohydrodynamic model is as follows:

[0133]

[0134]

[0135]

[0136]

[0137]

[0138] In the formula, n is the total number of switchgear species, C pmix For the specific heat of switching equipment under species disturbance, The viscosity of switching devices based on species interference, The viscosity of switching devices based on species interference, k represents the conductivity of the switching equipment under species interference. mix C represents the thermal conductivity of switching equipment under species interference. pi Y is the isobaric specific heat of the i-th species. i Let be the quality score of the i-th species of the switching device. Let be the density of the i-th species. Let be the viscosity of the i-th species. Let M be the electrical conductivity of the i-th species. i Let k be the molar mass of the i-th species. i Let be the thermal conductivity of the i-th species.

[0139] In this embodiment, the calculation module 20 is further configured to calculate the evaporation rate and mass fraction of each species in the switching device based on the arc parameter data using the Langmuir formula and the species transport equation; and to calculate the Stefan velocity of the switching device electrode and its cavity wall surface using the flow rate calculation formula based on the evaporation rate and mass fraction of all species in the switching device; the Langmuir formula is:

[0140]

[0141]

[0142] The species transport equation is:

[0143]

[0144] The formula for calculating flow velocity is:

[0145]

[0146] In the formula, For Stefan flow rate, Y i Let be the quality score of the i-th species of the switching equipment, and n be the total number of species of the switching equipment; P is the atomic evaporation rate. eq To balance the vapor pressure, m0 is the single-atom mass of the electrode material, k B Where P is Boltzmann's constant, T is the surface temperature of the electrode, and P is the surface temperature of the electrode. i Let be the partial vapor pressure of the i-th species. Let S be the evaporation rate of the i-th species in the switching equipment. i Let i be the source term for the i-th species. Let be the density of the i-th species. Let be the velocity of the flow field in the switchgear, D be the diffusion coefficient of the steam in the switchgear, and t be time.

[0147] It should be noted that the modules in the apparatus of Embodiment 2 correspond to the steps in the method of Embodiment 1. The calculation method of the parameters of the influence of the ablation steam on the combustion characteristics of the switch arc has been described in detail in Embodiment 1. Therefore, the contents of the modules in the apparatus will not be described in detail in Embodiment 2.

[0148] Example 3:

[0149] This application provides a terminal device, including a processor and a memory;

[0150] Memory is used to store program code and transfer the program code to the processor;

[0151] The processor is used to execute the above-mentioned parameter calculation method for the influence of ablation steam on the combustion characteristics of the switching arc according to the instructions in the program code.

[0152] It should be noted that the processor is used to execute the steps in the above-described method embodiment for calculating the effect of ablation steam on the combustion characteristics of a switching arc, according to the instructions in the program code. Alternatively, when the processor executes the computer program, it implements the functions of each module / unit in the above-described system / device embodiments.

[0153] For example, a computer program can be divided into one or more modules / units, one or more of which are stored in memory and executed by a processor to complete this application. One or more modules / units can be a series of computer program instruction segments capable of performing a specific function, which describe the execution process of the computer program in a terminal device.

[0154] Terminal devices can be computing devices such as desktop computers, laptops, handheld computers, and cloud servers. Terminal devices may include, but are not limited to, processors and memory. Those skilled in the art will understand that this does not constitute a limitation on the terminal device, which may include more or fewer components than illustrated, or combinations of certain components, or different components. For example, a terminal device may also include input / output devices, network access devices, buses, etc.

[0155] The processor referred to can be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor can be a microprocessor or any conventional processor.

[0156] Memory can be an internal storage unit of a terminal device, such as a hard drive or RAM. Memory can also be an external storage device, such as a plug-in hard drive, SmartMedia Card (SMC), Secure Digital (SD) card, or Flash Card. Furthermore, memory can include both internal and external storage units. Memory is used to store computer programs and other programs and data required by the terminal device. Memory can also be used for temporary storage of data that has been output or will be output.

[0157] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0158] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be an indirect coupling or communication connection between apparatuses or units through some interfaces, and may be electrical, mechanical, or other forms.

[0159] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0160] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0161] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0162] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A method for calculating parameters affecting the combustion characteristics of ablation steam on a switching arc, characterized in that, Includes the following steps: Acquire the arc parameter data of the switching device, which includes the diffusion coefficient of vapor, flow field velocity, equilibrium vapor pressure, Boltzmann constant, single atom mass of electrode material, surface temperature of electrode, and initial total pressure, source term and density of each species; Based on the arc parameter data, the evaporation rate and mass fraction of each species in the switching equipment are calculated; And based on the evaporation rate and mass fraction of all species in the switching device, the Stefan flow rate of the switching device electrode and its cavity wall surface is calculated. The evaporation rate and the Stefan flow velocity are coupled through boundary conditions to construct a magnetohydrodynamic model of the switching device; The thermodynamic parameters of the magnetohydrodynamic model are updated based on the mass fraction of all species in the switching device; the thermodynamic parameters include the specific heat, density, viscosity, thermal conductivity, and electrical conductivity of the switching device under species disturbance. The mapping relationship of the switching device is obtained, and the arc root tilt angle and arc center curvature radius of the switching device are calculated based on the Stefan flow rate, the mass fraction of each species and the mapping relationship using the arc spatiotemporal distribution. The boundary conditions are as follows: , For Stefan flow rate, Y i Let be the quality score of the i-th species of the switching device. Let be the evaporation rate of the i-th species in the switching equipment. Let be the density of the i-th species; the mapping relationship includes the mapping between the flow field of the switching device and the species mass fraction, the mapping between the flow field and the arc root radius, and the mapping between the arc length and the current; The expression for the spatiotemporal distribution of the electric arc is: In the formula, The angle of inclination of the arc root of the switchgear. For Stefan flow rate, Y i Let f1 be the mass fraction of the i-th species in the switching device, r be the arc root radius, f1 be the mapping relationship between the flow field and the species mass fraction, f2 be the mapping relationship between the flow field and the arc root radius, F be the mapping relationship between the arc length and the current, l be the arc column length of the switching device, j be the current density of the switching device, A be a coefficient, and R be the arc center curvature radius of the switching device. Based on the mass fraction of all species in the switching equipment, the specific heat, density, viscosity, thermal conductivity, and electrical conductivity of the switching equipment under species interference were calculated using the calculation formula of the magnetohydrodynamic model. The calculation formula of the magnetohydrodynamic model is as follows: In the formula, n is the total number of switchgear species, C pmix For the specific heat of switching equipment under species disturbance, The viscosity of switching devices based on species interference, The viscosity of switching devices based on species interference, k represents the conductivity of the switching equipment under species interference. mix C represents the thermal conductivity of switching equipment under species interference. pi Y is the isobaric specific heat of the i-th species. i Let be the quality score of the i-th species of the switching device. Let be the density of the i-th species. Let be the viscosity of the i-th species. Let M be the electrical conductivity of the i-th species. i Let k be the molar mass of the i-th species. i Let be the thermal conductivity of the i-th species.

2. The parameter calculation method for the influence of ablation steam on the combustion characteristics of a switching arc according to claim 1, characterized in that, The evaporation rate and mass fraction of each species in the switching equipment are calculated based on the arc parameter data, including: using the Langmuir formula and the species transport equation to calculate the evaporation rate and mass fraction of each species in the switching equipment; the Langmuir formula is: The species transport equation is as follows: In the formula, P is the atomic evaporation rate. eq To balance the vapor pressure, m0 is the single-atom mass of the electrode material, k B Where P is Boltzmann's constant, T is the surface temperature of the electrode, and P is the surface temperature of the electrode. i Let be the partial vapor pressure of the i-th species. Y represents the evaporation rate of the i-th species in the switching equipment. i Let S be the quality fraction of the i-th species in the switching device. i Let i be the source term for the i-th species. Let be the density of the i-th species. Let be the velocity of the flow field in the switchgear, D be the diffusion coefficient of the steam in the switchgear, and t be time.

3. The parameter calculation method for the influence of ablation steam on the combustion characteristics of a switching arc according to claim 1, characterized in that, The Stefan flow rate of the switchgear electrode and its cavity wall surface is calculated based on the evaporation rate and mass fraction of all species in the switchgear, including: calculating the Stefan flow rate of the switchgear electrode and its cavity wall surface using a flow rate calculation formula based on the evaporation rate and mass fraction of all species in the switchgear; the flow rate calculation formula is: In the formula, For Stefan flow rate, Y i Let be the mass fraction of the i-th species in the switchgear, D be the diffusion coefficient of the vapor in the switchgear, and n be the total number of species in the switchgear.

4. A parameter calculation device for the influence of ablation steam on the combustion characteristics of a switching arc, characterized in that, It includes a data acquisition module, a calculation module, a model building module, an update calculation module, and an arc parameter calculation module; The data acquisition module is used to acquire the arc parameter data of the switching equipment. The arc parameter data includes the diffusion coefficient of vapor, the velocity of the flow field, the equilibrium vapor pressure, the Boltzmann constant, the single-atom mass of the electrode material, the surface temperature of the electrode, and the initial total pressure, source term, and density of each species. The calculation module is used to calculate the evaporation rate and mass fraction of each species in the switching device based on the arc parameter data; and to calculate the Stefan flow rate of the switching device electrode and its cavity wall surface based on the evaporation rate and mass fraction of all species in the switching device. The model building module is used to couple the evaporation rate and the Stefan flow velocity through boundary conditions to build a magnetohydrodynamic model of the switching device. The update calculation module is used to update the thermodynamic parameters of the magnetohydrodynamic model based on the mass fraction of all species in the switching device; the thermodynamic parameters include the specific heat, density, viscosity, thermal conductivity, and electrical conductivity of the switching device under species disturbance. The arc parameter calculation module is used to obtain the mapping relationship of the switching device. Based on the Stefan flow rate, the mass fraction of each species and the mapping relationship, the arc spatiotemporal distribution is used to calculate the arc root tilt angle and arc center curvature radius of the switching device. The boundary conditions are as follows: , For Stefan flow rate, Y i Let be the quality score of the i-th species of the switching device. Let be the evaporation rate of the i-th species in the switching equipment. Let be the density of the i-th species; the mapping relationship includes the mapping between the flow field of the switching device and the species mass fraction, the mapping between the flow field and the arc root radius, and the mapping between the arc length and the current; The expression for the spatiotemporal distribution of the electric arc is: In the formula, The angle of inclination of the arc root of the switchgear. For Stefan flow rate, Y i Let f1 be the mass fraction of the i-th species in the switching device, r be the arc root radius, f1 be the mapping relationship between the flow field and the species mass fraction, f2 be the mapping relationship between the flow field and the arc root radius, F be the mapping relationship between the arc length and the current, l be the arc column length of the switching device, j be the current density of the switching device, A be a coefficient, and R be the arc center curvature radius of the switching device. The update calculation module is also used to calculate the specific heat, density, viscosity, thermal conductivity, and electrical conductivity of the switchgear under species interference based on the mass fraction of all species in the switchgear and the calculation formula of the magnetohydrodynamic model; the calculation formula of the magnetohydrodynamic model is: In the formula, n is the total number of switchgear species, C pmix For the specific heat of switching equipment under species disturbance, The viscosity of switching devices based on species interference, The viscosity of switching devices based on species interference, k represents the conductivity of the switching equipment under species interference. mix C represents the thermal conductivity of switching equipment under species interference. pi Y is the isobaric specific heat of the i-th species. i Let be the quality score of the i-th species of the switching device. Let be the density of the i-th species. Let be the viscosity of the i-th species. Let M be the electrical conductivity of the i-th species. i Let k be the molar mass of the i-th species. i Let be the thermal conductivity of the i-th species.

5. The parameter calculation device for the influence of ablation steam on the combustion characteristics of a switching arc according to claim 4, characterized in that, The calculation module is further configured to calculate the evaporation rate and mass fraction of each species in the switching device based on the arc parameter data using the Langmuir formula and the species transport equation; and to calculate the Stefan velocity of the switching device electrodes and their cavity wall surfaces using a flow rate calculation formula based on the evaporation rate and mass fraction of all species in the switching device; the Langmuir formula is: The species transport equation is as follows: The formula for calculating the flow velocity is: In the formula, For Stefan flow rate, Y i Let be the quality score of the i-th species of the switching equipment, and n be the total number of species of the switching equipment; P is the atomic evaporation rate. eq To balance the vapor pressure, m0 is the single-atom mass of the electrode material, k B Where P is Boltzmann's constant, T is the surface temperature of the electrode, and P is the surface temperature of the electrode. i Let be the partial vapor pressure of the i-th species. Let S be the evaporation rate of the i-th species in the switching equipment. i Let i be the source term for the i-th species. Let be the density of the i-th species. Let be the velocity of the flow field in the switchgear, D be the diffusion coefficient of the steam in the switchgear, and t be time.

6. A terminal device, characterized in that, Including the processor and memory; The memory is used to store program code and transmit the program code to the processor; The processor is configured to execute, according to the instructions in the program code, the parameter calculation method for the influence of ablation steam on the combustion characteristics of a switching arc as described in any one of claims 1-3.

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