High-pressure gas circuit breaker nozzle preparation method and nozzle

Abstract

The invention discloses a high-pressure gas circuit breaker nozzle preparation method and a nozzle, which are applied to the technical field of high-pressure circuit breaker structure preparation, and are characterized in that a plurality of preset gradient schemes are simulated by establishing a transient coupling model, and candidate partition gradient schemes including a gas production layer, a corrosion-resistant layer and a transition layer are screened out; therefore, the influence of different partition material distribution on the short-time voltage buildup response and the accumulated damage and interface degradation rate can be directly compared and balanced; and finally, layered preparation is performed in a mold cavity according to the selected partition sequence and the material distribution table, and an original part is activated and enhanced, so that the material gradient and interface conditions obtained through simulation optimization are reproduced and enhanced in a solid part, and therefore, it is ensured that the nozzle has expected rapid pressure building and gas production capacities in the on-off transient stage; and through interlayer bonding and material compactness obtained through engineering manufacturing and interface treatment, the durability in the repeated breaking process is improved.

Description

Technical Field

[0001] This invention relates to the field of high-voltage circuit breaker structure fabrication technology, and in particular to a method for fabricating a high-voltage gas circuit breaker nozzle and the nozzle itself. Background Technology

[0002] The nozzle is a key component in high-voltage gas circuit breakers used to regulate the airflow field. Its geometry and material properties directly determine the pressure build-up, blowing intensity, and arc-extinguishing capability of the gas chamber. During the transient breaking process, the arc ablation of the nozzle material generates vapor and creates a short-term blockage effect. Combined with the turbulent cooling of the strong airflow, this can significantly improve the pressure and breaking performance of the gas chamber in a very short time. However, under high-capacity short-circuit breaking conditions, if ablation becomes uncontrolled, the nozzle material will degrade significantly, leading to an increase in throat diameter, which in turn causes a significant decrease in the repeated breaking capacity and service life of the circuit breaker. In recent years, environmentally friendly alternative gases, such as C4F7N / CO2, have been gradually applied to high-voltage breaking devices. Studies suggest that the arc ablation damage to the nozzle under this type of mixed gas may be more severe than that of SF6, and the radiation spectrum of the arc will bring additional photothermal and photochemical effects. Therefore, the material design needs to simultaneously consider controlled gas production and higher ablation resistance to match the energy dissipation characteristics of gas and arc coupling.

[0003] Existing nozzle fabrication methods primarily improve the thermal conductivity and arc erosion resistance of composite materials by introducing inorganic nano- or micro-fillers (such as h-BN, Al2O3, AlN, MoS2, etc.) into the PTFE matrix. Lamellar fillers (such as h-BN) have been shown in several experiments to enhance the arc resistance of the PTFE matrix due to their high interlayer thermal conductivity and good optical reflection properties; high thermal conductivity fillers (such as AlN) are also used to improve heat conduction and reduce local thermal stress. Furthermore, PTFE ablation models based on local pressure changes and variable enthalpy of vaporization have been used for coupled simulation analysis of nozzle deformation and gas chamber pressure field to guide design. However, most existing nozzle fabrication methods focus on optimizing a single filler type or homogeneous formulation, failing to consider the non-uniform arc loads and differentiated requirements experienced by the nozzle on the arc-side, throat, and outer side from the perspective of spatial functional zoning. This makes it difficult to achieve an ideal trade-off between short-term gas production capacity and long-term durability. On the one hand, the thermal, mechanical, and chemical boundary conditions experienced by different parts of the nozzle under the action of the electric arc are significantly different (e.g., the arc side is subjected to high energy density and strong spectral radiation, while the throat is subjected to high dynamic pressure and mechanical stress). A single homogeneous material cannot simultaneously meet these contradictory local requirements. On the other hand, the interactions between different fillers and organic gas-generating agents in terms of thermal decomposition behavior, interfacial bonding, and thermal transport performance are complex, and their macroscopic engineering performance requires multi-scale mapping and optimization for reliable prediction. In addition, the chemical and photothermal mechanisms of alternative gases such as C4F7N and CO2 differ from those of SF6, making it difficult to achieve a performance combination that can both generate controlled short-term gas production and maintain long-term ablation resistance under actual operating conditions by simply using existing homogeneous formulations and conventional processes. Summary of the Invention

[0004] This invention provides a method for preparing a high-voltage gas circuit breaker nozzle and a nozzle that balances the transient pressure build-up and repeated breaking life of the nozzle.

[0005] To address the aforementioned technical problems, embodiments of the present invention provide a method for preparing a high-voltage gas circuit breaker nozzle, comprising: Obtain a list of candidate materials and initial configuration parameters; construct molecular and interface atomic models based on the list of candidate materials and initial configuration parameters; and calculate the first physical property parameters based on the molecular and interface atomic models and molecular dynamics. The first physical property parameter is mapped to the second physical property parameter based on the preset scale bridging method, and a transient coupling model is established based on the second physical property parameter; Gradient structure simulation is performed based on the transient coupling model and a preset gradient scheme to obtain the performance parameters corresponding to the preset gradient scheme. Candidate partitioning gradient schemes are then obtained based on these performance parameters. Each candidate partitioning gradient scheme includes several candidate partitions, a partitioning order, and a material distribution table corresponding to each candidate partition. Each candidate partition includes a gas-generating layer, a corrosion-resistant scorching layer, and a transition layer. Based on the partitioning sequence, the gas-generating layer, corrosion-resistant burning layer, and transition layer are set in the mold cavity. Based on the material distribution table corresponding to each candidate partition, the original nozzle part is prepared in the mold cavity. The original nozzle part is then activated and enhanced to obtain the high-voltage gas circuit breaker nozzle.

[0006] This invention first obtains a list of candidate materials and initial configuration parameters, constructs a model at the atomic, molecular, and interface scales, and calculates the first physical property parameters using molecular dynamics. This allows for the quantification of physical quantities affecting instantaneous gas generation and interface durability, such as gas production rate and reaction kinetics, interfacial bonding and interfacial mechanical response, at the microscopic level. Subsequently, the first physical property parameters are bridged and mapped to second physical property parameters at a preset scale, and a transient coupling model is established, enabling the microscopic characterization to be computably reflected in the macroscopic transient state. Based on this transient coupling model, simulations are performed on several preset gradient schemes to obtain performance parameters, thereby selecting candidate partitioned gradient schemes that include a gas-generating layer, a corrosion-resistant burning layer, and a transition layer. In the scheme selection stage, the impact of different partition material distributions on two types of performance—"short-term pressure build-up response" and "cumulative damage and interface degradation rate"—is directly compared and weighed. Finally, according to the selected partition order and material distribution table, the parts are prepared in layers in the mold cavity, and the original parts are activated and enhanced. This allows the material gradient and interface conditions obtained from simulation optimization to be reproduced and strengthened in the solid parts. This ensures that the nozzle has the expected rapid pressure build-up and gas production capabilities in the transient phase of the break, and improves the durability in the repeated break process through the interlayer bonding and material density obtained by engineering manufacturing and interface treatment. This helps to achieve a verifiable and manufacturable trade-off and optimization between transient pressure build-up efficiency and long-term break life.

[0007] Furthermore, the steps of obtaining a candidate material list and initial configuration parameters, constructing a molecular and interface atomic model based on the candidate material list and initial configuration parameters, and calculating the first physical property parameters based on the molecular and interface atomic model and molecular dynamics include: Obtain a candidate material list and initial configuration parameters. The candidate material list includes alternative matrix materials, functional fillers, and interface modifiers and their characterization indicators. The initial configuration parameters include the number of nozzle partitions, the geometry of each partition, the target operating temperature and pressure range, and the target porosity. Based on the candidate material list and initial configuration parameters, molecular unit models and functional filler atomic models are constructed, and interface atomic models are assembled at the atomic scale according to the initial configuration parameters. Molecular and interface atomic models are constructed based on the molecular unit model and the interface atomic model. The first physical property parameters are calculated based on the molecular and interface atomic model and molecular dynamics.

[0008] This invention defines a candidate material list including alternative matrices, functional fillers, and interface modifiers and their characterization indicators, and clarifies initial configuration parameters. It also constructs molecular units and interface atomic models at the atomic scale. By accurately characterizing material composition, filler and interface control factors, as well as geometric and operating parameters such as nozzle partitioning and porosity at the model input level, subsequent microscopic calculations can accurately reflect the gas generation potential and interfacial mechanical properties of the material under high-temperature transient conditions. This provides reliable data for determining whether a material partitioning scheme can simultaneously achieve rapid and controllable transient pressure build-up and low cumulative interfacial damage during the design phase, facilitating the early screening of material combinations that balance both aspects.

[0009] Furthermore, the calculation of the first physical property parameters based on the molecular and interface atomic model and molecular dynamics includes: The molecular and interface atomic models are preprocessed based on a preset potential energy function to obtain the target molecular and interface atomic models; Based on molecular dynamics, equilibrium simulation and production-state molecular dynamics (MD) operation simulation were performed on the target molecule and interface atomic model to obtain the production-state MD trajectory. Based on the production-state MD trajectory, the interface binding energy, interface diffusion coefficient, local thermal conductivity or thermal interface thermal conductivity, elastic modulus and stress-strain response, interface fracture energy, gas production rate and reaction activation energy are calculated to generate the first physical property parameters.

[0010] This invention preprocesses the potential energy function of the constructed molecular and interface atomic models and performs equilibrium and production state molecular dynamics simulations. It extracts primary physical property parameters such as interfacial binding energy, diffusion coefficient, local thermal conductivity or thermal interface thermal conductivity, elastic modulus and stress-strain response, interfacial fracture energy, gas production rate and reaction activation energy from the production state trajectory. Then, by quantitatively obtaining key microscopic parameters affecting transient gas release rate, energy transfer, and interface and material durability, it can evaluate the impact of a partition design on short-term pressure build-up response and on interfacial fatigue or fracture tendency at the physical mechanism level. This provides a solid physical basis for the parallel trade-off of the two properties in subsequent macroscopic simulation and process implementation.

[0011] Furthermore, the step of mapping the first physical property parameter to a second physical property parameter based on a preset scale bridging method, and establishing a transient coupling model based on the second physical property parameter, includes: The first physical property parameter is mapped to the second physical property parameter based on a preset scale bridging method; The second physical property parameters are used to generate a material property table based on a preset format, and a transient coupled model is constructed based on the material property table as unit properties and domain properties.

[0012] Furthermore, the gradient structure simulation is performed based on the transient coupling model and a preset gradient scheme to obtain the performance parameters corresponding to the preset gradient scheme, and candidate partition gradient schemes are obtained based on the performance parameters; the candidate partition gradient scheme includes several candidate partitions, partition order, and a material distribution table corresponding to each candidate partition, including: Several gradient schemes are preset, and simulations are performed on the transient coupling model based on these schemes to obtain material gas generation and heat transfer parameters, as well as mechanical and interface parameters. A multi-objective optimization algorithm is constructed based on the gas generation and heat transfer parameters of the material, as well as the mechanical and interface parameters. The algorithm is then used to perform transient solutions for each gradient scheme under preset multiple operating conditions to obtain the optimal candidate partition gradient scheme.

[0013] This invention maps a first physical property parameter to macroscopic physical properties and constructs a transient coupling model using a material property table. It performs multi-condition transient simulations on several preset gradient schemes and obtains the optimal candidate partitioning gradient scheme through multi-objective optimization. By using scale bridging and transient coupling simulation, it can evaluate the macroscopic gas generation and heat transfer parameters and macroscopic mechanical and interface parameters of different gradient partitioning schemes at the macroscopic level. Since the macroscopic gas generation and heat transfer parameters determine the transient pressure build-up capability, and the macroscopic mechanical and interface parameters determine the macroscopic damage or stress evolution related to the cumulative breaking life, the transient pressure build-up capability and macroscopic damage or stress evolution of the partitioning scheme can be evaluated in parallel. Through multi-objective optimization, the partitioning scheme that achieves the best trade-off between "pressure build-up response" and "durability" under multi-condition constraints is selected, thus reflecting the trade-off between transient pressure build-up and cumulative breaking life in a manufacturable design scheme.

[0014] Furthermore, the step of preparing the original nozzle component based on the candidate partitions, partition order, and material distribution table corresponding to each candidate partition, and then performing activation and enhancement treatments on the original nozzle component to obtain a high-voltage gas circuit breaker nozzle, includes: Based on the material distribution table, the filler content of the masterbatch powder in each candidate partition is determined, and the masterbatch powder in each candidate partition is layered and filled into the mold cavity based on the partition order and filler content; The mold cavity is subjected to multi-stage hot pressing solid-state sintering, slow cooling, and CNC precision machining to obtain the original nozzle part; The original nozzle component is activated and enhanced to obtain a high-voltage gas circuit breaker nozzle.

[0015] This invention determines the content of filler powder in each candidate partition based on a material distribution table, fills the mold cavity in layers according to the partition order, and prepares the nozzle part through multi-stage hot pressing solid-state sintering, slow cooling and CNC precision machining, and subsequent activation and reinforcement treatment. By realizing the partition filler content and layering process according to the design, and by using controlled hot pressing and post-processing, the material gradient and interface quality obtained by simulation optimization can be reproduced in the physical part. This ensures that the selected partition scheme can not only realize the transient pressure build-up behavior predicted during design in the actual part, but also improve the interlayer bonding and overall material strength through optimized densification and interface activation processes, and reduce the risk of interface degradation and early failure caused by repeated fractures.

[0016] Secondly, the present invention provides a high-voltage gas circuit breaker nozzle, which is manufactured using the aforementioned high-voltage gas circuit breaker nozzle preparation method; The nozzle body is provided with an ablation-resistant layer, a transition layer and a gas-generating layer in sequence along the axial or radial direction; the ablation-resistant layer, the transition layer and the gas-generating layer are distributed in a gradient according to the partition order, and a gradient transition zone is provided between adjacent layers.

[0017] This invention sequentially comprises an ablation-resistant layer, a transition layer, and a gas-generating layer, distributed in a continuous or stepped gradient in the radial or axial direction, with a gradient transition zone between adjacent layers. This structure spatially distributes the "gas-generating function" and "ablation-resistant load-bearing" function to different layers and connects them with gradient transition zones. This allows the outer layer to quickly participate in transient pressure build-up, while the inner layer maintains high structural density and durability. The gradient transition zone helps alleviate interfacial stress caused by thermodynamic abrupt changes, thus simultaneously considering both short-term pressure build-up efficiency and the lifespan requirement of maintaining geometric and interfacial stability during repeated interruptions in the structural layout.

[0018] Furthermore, the gas-generating layer is composed of an organic polymer material, and an organic gas-generating additive is dispersed in the gas-generating layer; the organic polymer material includes polytetrafluoroethylene and its modified system; the organic gas-generating additive includes one or more of fumaric acid, cyanuric acid and orotic acid.

[0019] The gas-generating layer of this invention is composed of organic polymer materials and contains dispersed organic gas-generating additives. This allows the material system of the gas-generating layer to achieve controllable decomposition and gas release when heated through the combination of the organic matrix and specific additives. Thus, it can provide the necessary gas during the transient phase of nozzle operation to promote instantaneous pressure build-up and arc extinguishing. At the same time, the selective design of the organic matrix and additives can control the gas generation process and prevent excessive acceleration of the matrix wear, thereby supporting short-term pressure build-up while avoiding excessively rapid reduction in cumulative interruption life.

[0020] Furthermore, the ablation-resistant layer is composed of an inorganic ceramic matrix composite material, which includes one or more of alumina, silicon nitride, and silicon carbide.

[0021] The ablation-resistant layer of this invention is an inorganic ceramic matrix composite material containing alumina, silicon nitride, or silicon carbide. By using this type of high-temperature stable, low-volatility ceramic matrix material as the inner layer, the geometric stability of the inner cavity and low material loss can be maintained under the conditions of high arc temperature and repeated interruption. This ensures that the morphology of the nozzle throat and the channel maintain the necessary flow characteristics after multiple interruptions, which is conducive to maintaining a long-term stable transient pressure build-up response and significantly improving the cumulative interruption life.

[0022] Furthermore, the transition layer is composed of an organic and inorganic composite system, which includes nano- or micron-sized ceramic particles uniformly dispersed in a resin matrix. The ceramic particles include one or more of alumina, aluminum nitride, silicon carbide, and zirconium oxide.

[0023] The transition layer of this invention is an organic-inorganic composite system with resin as the matrix and uniformly dispersed nano- or micron-sized ceramic particles. The beneficial effects of this transition layer are: its high toughness and improved thermal conductivity or mechanical properties act as a buffer and transition between the inner and outer layers, mitigating the transfer of thermal stress caused by gas generation or sudden temperature changes in the outer layer to the ablation-resistant layer, thereby reducing the rate of interface damage accumulation; simultaneously, its moderate thermal conductivity helps to make gas generation triggering or thermal activation conditions more controllable, facilitating a balance between short-term pressure build-up and long-term durability. Attached Figure Description

[0024] Figure 1 This is a schematic flowchart illustrating a method for preparing a high-voltage gas circuit breaker nozzle according to an embodiment of the present invention. Figure 2 This is a schematic diagram of the structure of an inorganic packing material provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of the structure of an organic additive provided in an embodiment of the present invention; Figure 4 A cross-sectional schematic diagram of a high-voltage gas circuit breaker nozzle provided in this embodiment of the invention; Figure 5 This is a schematic diagram illustrating the coordinated control of nozzle ablation gas production in an embodiment of the present invention. Figure 6 This is a schematic diagram of the transient flow field profile of a nozzle provided in an embodiment of the present invention. Detailed Implementation

[0025] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and are not intended to limit the scope of the invention.

[0026] The terms "first" and "second," etc., in the specification, claims, and drawings of this application are used to distinguish different objects, not to describe a specific order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to such processes, methods, products, or apparatus.

[0027] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0028] Example 1 See Figure 1 , Figure 1 This is a schematic flowchart illustrating a method for preparing a high-voltage gas circuit breaker nozzle according to an embodiment of the present invention. The embodiment of the present invention provides a method for preparing a high-voltage gas circuit breaker nozzle, including steps 101 to 104, as detailed below: Step 101: Obtain a list of candidate materials and initial configuration parameters; construct molecular and interface atomic models based on the list of candidate materials and initial configuration parameters; and calculate the first physical property parameters based on the molecular and interface atomic models and molecular dynamics. In this embodiment, the steps of obtaining a candidate material list and initial configuration parameters, constructing a molecular and interface atomic model based on the candidate material list and initial configuration parameters, and calculating the first physical property parameters based on the molecular and interface atomic model and molecular dynamics include: Obtain a candidate material list and initial configuration parameters. The candidate material list includes alternative matrix materials, functional fillers, and interface modifiers and their characterization indicators. The initial configuration parameters include the number of nozzle partitions, the geometry of each partition, the target operating temperature and pressure range, and the target porosity. Based on the candidate material list and initial configuration parameters, molecular unit models and functional filler atomic models are constructed, and interface atomic models are assembled at the atomic scale according to the initial configuration parameters. Molecular and interface atomic models are constructed based on the molecular unit model and the interface atomic model. The first physical property parameters are calculated based on the molecular and interface atomic model and molecular dynamics.

[0029] In this embodiment, after constructing a periodic supercell model of the PTFE matrix, the molecular and interface atomic models are preprocessed based on a preset potential energy function to obtain the target molecular and interface atomic models. For example, a force field such as COMPASS can be used as the preset potential energy function. Density functional theory (DFT) is used to perform energy correction and electronic structure analysis on the bonding and chemisorption energies for several representative interface configurations to improve the reliability of the interface binding energy estimation.

[0030] In this embodiment, representative filler and additive models are constructed: inorganic fillers include lamellar or particle models of h-BN, Al2O3, AlN, CoO-Al2O3, MoS2, Si3N4, etc., taking into account typical particle sizes and morphologies; organic gas-generating additives include fumaric acid, cyanuric acid, orotic acid, etc., and possible primary reaction configurations are determined. The above-mentioned inorganic fillers and organic gas-generating additives are exported to molecular dynamics software. Based on molecular dynamics, equilibrium simulation and production-state MD (production-state molecular dynamics) simulation are performed on the target molecule and interface atomic models to obtain the production-state MD trajectory. On this basis, the non-equilibrium molecular dynamics (NEMD) method is used to calculate the interface and overall thermal conductivity.

[0031] In this embodiment, in order to reveal the sensitivity of filler content to interface and thermal transport performance, a content parameter scan should be performed. The default content parameter points are set to 5%, 10%, 15%, 20%, 30%, and 40%. For formulations containing organic gas-producing components, high-temperature thermal decomposition simulations (temperature range 500–2000 K, step size or finer according to experimental intervals) are performed under NVT / NPT conditions using reactive molecular dynamics driven by a reactive force field (ReaxFF). Bond breaking frequencies, key intermediates and stable gaseous products, and their instantaneous gas production rates are recorded. The microscopic outputs are then used as the first physical property parameters, including interfacial binding energy, interlayer / global thermal conductivity, decomposition temperature and activation energy, instantaneous gas production rate, and product spectra. These first physical property parameters are input into a surrogate model (such as an artificial neural network or Gaussian process regression) to establish a response surface. A multi-objective Pareto optimization problem is then solved using NSGA-II. The optimization objectives include at least minimizing linear ablation rate or mass loss, maximizing short-term gas production rate, maximizing interfacial binding energy, and improving thermal conductivity. This outputs the optimal formulation candidate and corresponding microscopic parameters that balance gas production and corrosion resistance, providing direct quantitative basis for subsequent engineering scale-up.

[0032] In this embodiment, the constructed molecular and interface atomic models are first preprocessed based on a preset potential function (i.e., force field) to obtain the target molecular and interface atomic models. Preprocessing includes assigning appropriate atom types, bond angles, and non-bonded interaction parameters, and performing preliminary energy minimization to eliminate configurational stress. Subsequently, molecular dynamics (MD) numerical simulations are performed on the target molecular and interface atomic models. First, equilibrium simulations are conducted to bring the system to thermodynamic steady state (e.g., equilibrium under the NVT / NPT ensemble, where NVT is a constant particle number-constant volume-isothermal ensemble; NPT is a constant particle number-constant pressure-isothermal ensemble). Then, production-state MD (production-state molecular dynamics) simulations are executed to obtain the production-state MD trajectory representing actual working or high-temperature pyrolysis conditions. Based on the production-state MD trajectory, the first physical property parameters are calculated and generated using a property quantification method. Specifically, the interface binding energy is calculated from the difference between the total energy of the system and the energy of each component using the energy difference method. Energy is used to quantify the adsorption and bonding strength of the matrix-filler or matrix-modifier interface; the interface diffusion coefficient is obtained by fitting the mean square displacement (MSD) of the trajectory to the Einstein relation, which is used to characterize the migration rate of atoms or small molecules at the interface and near the interface; heat flux or temperature difference is applied using non-equilibrium molecular dynamics (NEMD) and calculated from steady-state temperature gradient / heat flux, or the local thermal conductivity or thermal interface conductance is estimated from the autocorrelation function integral using the Green-Kubo formula; the corresponding elastic constants and nonlinear mechanical behavior are obtained by applying controlled deformation (tension, compression, or shear) to representative units and recording the stress-strain curves, thereby calculating the elastic modulus and stress-strain response. The stress-strain response is used to calculate the interface fracture energy by introducing cracks into the model or by performing a stepwise stretching simulation using separation energy or binding energy curves to obtain the energy required for interface rupture.For components containing organic gas-producing components, reactive molecular dynamics driven by a reactive force field (ReaxFF) directly simulates bond breaking, intermediate generation, and stable gaseous products under high-temperature conditions, and statistically analyzes the instantaneous gas generation rate. Combined with the reaction rates at different temperatures, the activation energy can be obtained using Arrhenius fitting, thereby calculating the gas generation rate and reaction activation energy.

[0033] In this embodiment, the calculation process of the first physical property parameter should record and retain the production-state MD trajectory and post-processing script to ensure repeatability. The obtained parameters can be used as input for multi-scale scale bridging, or as quantitative data for surrogate model training and response surface construction to support subsequent multi-objective optimization and engineering scale-up.

[0034] This invention obtains a candidate material list including alternative matrices, functional fillers, and interface modifiers and their characterization indicators, and clarifies initial configuration parameters. It then constructs molecular units and interface atomic models at the atomic scale. By accurately characterizing material composition, filler and interface control factors, as well as geometric and operating parameters such as nozzle partitioning and porosity at the model input level, subsequent microscopic calculations can accurately reflect the gas generation potential and interfacial mechanical properties of the material under high-temperature transient conditions. This provides reliable data for determining whether a material partitioning scheme can simultaneously achieve rapid and controllable transient pressure build-up and low cumulative interfacial damage during the design phase, facilitating the early screening of material combinations that balance both aspects.

[0035] Step 102: Map the first physical property parameter to a second physical property parameter based on the preset scale bridging method, and establish a transient coupling model based on the second physical property parameter; In this embodiment, the step of mapping the first physical property parameter to a second physical property parameter based on a preset scale bridging method, and establishing a transient coupling model based on the second physical property parameter, includes: The first physical property parameter is mapped to the second physical property parameter based on a preset scale bridging method; The second physical property parameters are used to generate a material property table based on a preset format, and a transient coupled model is constructed based on the material property table as unit properties and domain properties.

[0036] In this embodiment, the obtained microscopic first physical property parameters, such as interfacial binding energy, interlayer and global thermal conductivity, decomposition activation energy, instantaneous gas production rate, local elastic modulus and stress-strain response, interfacial diffusion coefficient, etc., are first mapped into second physical property parameters usable by the continuous medium through a preset scale bridging method. The second physical property parameters include effective thermal conductivity, specific heat capacity, density, elastic modulus, linear expansion coefficient, porosity-dependent permeability, volumetric source term characterizing gas production or macroscopic reaction rate constant and its temperature dependence, etc.

[0037] In this embodiment, the scale bridging method can be selected from the volume weighted average method, the microstructure factor correction method, the volume average correction based on morphology factor, contact surface fraction or connectivity, or the response surface interpolation method based on the surrogate model. The surrogate model can use artificial neural network or Gaussian process regression to map the microscopic input to the macroscopic output and output uncertainty estimate at the same time to control the uncertainty propagation in the microscopic to macroscopic mapping.

[0038] In this embodiment, the first physical property parameter refers to the microscopic physical property parameter derived from molecular and interface atomic models and molecular dynamics (MD) calculations, such as interface binding energy, diffusion coefficient of atomic and molecular migration, local thermal conductivity or thermal interface thermal conductivity, local elastic modulus and stress-strain response, interface fracture energy, gas generation rate and reaction activation energy, etc. These parameters directly reflect the interaction, heat and mass transfer and chemical reaction mechanism of materials at the atomic and nanoscale. The second physical property parameter refers to the macroscopic physical property parameter obtained by mapping the first physical property parameter through a preset scale bridging method, such as effective thermal conductivity, specific heat capacity, density, elastic modulus, linear expansion coefficient, porosity-related permeability, macroscopic reaction rate constant and gas generation volume rate as a source term, etc., which can be directly used for engineering-level transient coupling simulations such as finite element / CFD.

[0039] In this embodiment, two types of physical property parameters are cascaded in the same design process and used for numerical mapping and coupled modeling. On the one hand, the microscopic mechanism can be quantitatively transferred to the engineering scale, thereby improving the physical consistency and credibility of simulation predictions and avoiding deviations caused by simply relying on experience or rough matching. On the other hand, it can greatly reduce the number of trial and error experiments and R&D costs. Through surrogate models and response surface optimization, formulations can be quickly screened and the optimal trade-off between gas production and corrosion resistance can be obtained. In addition, uncertainties can be quantified and propagated simultaneously during the mapping process, providing clear sensitivity indicators for engineering scale-up and quality control, and helping to formulate repeatable process windows. Finally, this method enables the material properties based on microscopic physical property design to be directly called in transient coupled simulations such as COMSOL Multiphysics, thereby achieving high-fidelity prediction of thermal, chemical, fluid and structural coupled behavior, supporting more reliable nozzle structure design, process formulation and life assessment, and improving the performance and long-term reliability of circuit breakers under repeated breaking conditions.

[0040] In this embodiment, the second physical property parameters are organized into a structured material property table according to a predetermined format. This property table records the property name, value or dependency expression for temperature, pressure, porosity, etc., unit, interpolation function type, corresponding microstructure identifier, and uncertainty interval by field, so as to facilitate programmatic calling. Then, the material property table is used as the element property and domain property to define the material in the solver (e.g., in the Materials node in COMSOL Multiphysics), and in Finite Element / Computational Fluid Dynamics (CFD). A transient coupled model is constructed within the framework of Computational Fluid Dynamics (CFD). This model should activate and couple the heat conduction module, fluid dynamics and porous media flow module, species transport and chemical reaction module, and structural mechanics module. In the coupling terms, the gas production rate obtained from microscopic mapping is injected into the continuity equation as a volumetric gas source term and a pressure source term. The heat release accompanying gas production is added to the energy equation as a volumetric heat source. The temperature-dependent decomposition reaction rate is introduced into the reaction term using an Arrhenius expression to drive transient matter-energy coupling. Furthermore, porosity-dependent permeability and adsorption and desorption rates are assigned to the spatial field to describe the effects of convection and seepage coupling after gas production. The instantaneous temperature field is mapped into a structural deformation driving term using a thermal expansion coupling operator to evaluate throat evolution.

[0041] In this embodiment, to ensure numerical stability and physical accuracy, the model implements local mesh refinement in high-gradient regions such as the interface and throat, and adopts adaptive, explicit, or implicit hybrid time steps to take into account both the short-term thermal shock of the arc and the time scale of long-term evolution. During the solution process, sensitivity analysis and uncertainty propagation are carried out to identify the second physical property parameter that has the greatest impact on performance. Finally, the solution results, such as transient temperature field, pressure field, velocity field, local material volume loss and throat diameter change, interface stress and crack initiation, are compared and corrected with experimental characterization data, such as thermal conductivity by laser flash method, gas generation spectrum by TGA / GC-MS, porosity distribution by X-ray CT and mechanical tests. This forms a closed-loop verification process from microscopic first physical property to macroscopic transient coupling prediction, providing reliable engineering input and decision-making basis for the design optimization and engineering scale-up of the nozzle gradient structure.

[0042] Step 103: Perform gradient structure simulation based on the transient coupling model and the preset gradient scheme to obtain the performance parameters corresponding to the preset gradient scheme, and obtain candidate partition gradient schemes based on the performance parameters; the candidate partition gradient scheme includes several candidate partitions, partition order, and material distribution table corresponding to each candidate partition; the candidate partitions include a gas-generating layer, a corrosion-resistant burning layer, and a transition layer; In this embodiment, gradient structure simulation is performed based on the transient coupling model and a preset gradient scheme to obtain performance parameters corresponding to the preset gradient scheme, and candidate partition gradient schemes are obtained based on the performance parameters; the candidate partition gradient scheme includes several candidate partitions, partition order, and a material distribution table corresponding to each candidate partition, including: Several gradient schemes are preset, and simulations are performed on the transient coupling model based on these schemes to obtain material gas generation and heat transfer parameters, as well as mechanical and interface parameters. A multi-objective optimization algorithm is constructed based on the gas generation and heat transfer parameters of the material, as well as the mechanical and interface parameters. The algorithm is then used to perform transient solutions for each gradient scheme under preset multiple operating conditions to obtain the optimal candidate partition gradient scheme.

[0043] In this embodiment, several gradient schemes are preset, including radial gradient, axial gradient, and mixed gradient. Each scheme includes several parameterized variants, such as the number of layers, thickness of each layer, width of the transition zone, initial porosity of each layer, and filler ratio. Each preset gradient scheme is used as input for numerical simulation in the transient coupling model. During the simulation, heat conduction, structural mechanics, fluid dynamics, or porous media flow modules are coupled, and chemical reaction and gas generation modules are coupled when necessary. The gas generation rate and heat release obtained from microscopic mapping are injected into the fluid and energy equations as volume source terms. Adaptive time stepping and local mesh refinement are used to analyze the transient response under short-time high gradients, such as temperature field 300–30000 K, pressure 0.1–10 MPa, and stress 0–500 MPa.

[0044] In this embodiment, the simulation output of each preset gradient scheme is a set of performance parameters, including: transient peak pressure rise and pressure rise rate of the gas chamber, throat diameter evolution curve and predicted throat diameter change, local material volume loss and ablation rate, transient heat flux distribution, local and global interface stress and crack initiation index, velocity field and permeation and channel evolution, and lifetime-related cumulative fracture degradation index, etc. These performance parameters can be used as constraints (e.g., maximum allowable throat diameter increase, maximum interface stress limit) or as objectives (e.g., maximizing short-term peak pressure rise, minimizing material volume loss).

[0045] In this embodiment, a multi-objective optimization process is constructed based on the material gas generation and heat transfer parameters, as well as the mechanical and interface parameters obtained from the above simulation. Specifically, firstly, a surrogate model is used to quickly evaluate each gradient scheme within the design space. Then, multi-objective optimization algorithms such as NSGA-II (Non-dominated Sorting Genetic Algorithm II) are used to perform transient solutions and Pareto optimizations on each gradient scheme under preset multiple operating conditions (e.g., different arc energies, breaking currents, and repeated breaking times). An objective function is constructed based on instantaneous pressure build-up capability, long-term ablation resistance, and structural integrity. The compromise solution among the three factors of "instantaneous pressure build-up capability, long-term ablation resistance, and structural integrity" is extracted according to the objective function.

[0046] In this embodiment, robustness and sensitivity analysis of the obtained Pareto front points are also required to screen out schemes that are highly sensitive to or unstable to process or material parameters. The final output of several candidate partition gradient schemes is given in the form of a structured "material distribution table". Each candidate scheme includes at least: the number of candidate partitions, the partition order, the material formulation (components and their mass or volume fraction) of each candidate partition, the target porosity or density range, the layer thickness, the geometry, the corresponding second physical property parameter entries and their temperature or pressure dependence expressions, the uncertainty interval and priority score; this material distribution table can be used as a direct process input for manufacturing processes, and can also be used as a basis for verification and selection during subsequent bench tests and engineering scale-up, thereby forming a closed-loop design and screening process from microscopic physical properties to macroscopic performance and then to manufacturable processes.

[0047] In this embodiment, by mapping the first physical property parameter to macroscopic physical properties and constructing a transient coupling model using a material property table, performing multi-condition transient simulations on several preset gradient schemes, and obtaining the optimal candidate partitioning gradient scheme through multi-objective optimization, the macroscopic gas generation and heat transfer parameters and macroscopic mechanical and interface parameters of different gradient partitioning schemes can be evaluated at the macroscopic level through scale bridging and transient coupling simulation. Since the macroscopic gas generation and heat transfer parameters determine the transient pressure build-up capability, and the macroscopic mechanical and interface parameters determine the macroscopic damage or stress evolution related to the cumulative breaking life, the transient pressure build-up capability and macroscopic damage or stress evolution of the partitioning scheme can be evaluated in parallel. Through multi-objective optimization, the partitioning scheme that achieves the best trade-off between "pressure build-up response" and "durability" under multi-condition constraints is selected, thus reflecting the trade-off between transient pressure build-up and cumulative breaking life in the manufacturable design scheme.

[0048] Step 104: Based on the partitioning sequence, set the gas generation layer, corrosion-resistant burning layer and transition layer in the mold cavity, and prepare the original nozzle part in the mold cavity based on the material distribution table corresponding to each candidate partition, and perform activation treatment and enhancement treatment on the original nozzle part to obtain the high-voltage gas circuit breaker nozzle.

[0049] In this embodiment, the process of setting the gas-generating layer, corrosion-resistant burning layer, and transition layer in the mold cavity based on the partitioning sequence, and preparing the original nozzle component in the mold cavity based on the material distribution table corresponding to each candidate partition, and performing activation and enhancement treatments on the original nozzle component to obtain a high-voltage gas circuit breaker nozzle, includes: Based on the aforementioned partitioning sequence, the gas-generating layer, the corrosion-resistant sintering layer, and the transition layer are disposed within the mold cavity; Based on the material distribution table, the filler content of the masterbatch powder in each zone of the gas-generating layer, corrosion-resistant burning layer, and transition layer is determined, and the masterbatch powder in each zone is filled into the corresponding area of ​​the mold cavity based on the filler content of each zone; The mold cavity is subjected to multi-stage hot pressing solid-state sintering, slow cooling, and CNC precision machining to obtain the original nozzle part; The original nozzle component is activated and enhanced to obtain a high-voltage gas circuit breaker nozzle.

[0050] In this embodiment, the material formulation and target filler content of each candidate zone are first determined according to the material distribution table. The material distribution table provides the composition of the masterbatch powder for each zone, such as matrix grade, filler type and particle size distribution, type and content of organic gas-generating additives, target porosity range, layer thickness and transition zone width, and other engineering parameters. Then, according to the zone order, the gas-generating layer masterbatch, transition layer masterbatch, and corrosion-resistant sintering layer masterbatch are sequentially set in the mold cavity. Each masterbatch powder is prepared by a dry or wet batching process under an inert atmosphere. The inorganic filler is first surface-treated to modify the surface energy and improve dispersibility, and the PTFE powder is mechanically roughened to improve wettability and contact mechanical properties. The "masterbatch powder" is the layered powder pre-prepared according to the design ratio to achieve accurate interlayer filling and porosity control. The masterbatch powder of each zone is layered and filled to the corresponding positions in the mold cavity according to the design, and an initial pressure (e.g., 0.5–5) is applied. The pressure is increased to MPa to remove air, followed by multi-stage hot pressing solid-state sintering under vacuum or nitrogen protection (heating to approximately 360–385 °C and holding for 10–60 min, using a controllable slow cooling curve to reduce thermal stress). The width of the interlayer transition zone is controlled at 0.5–2.0 mm to balance functional transition and stress dispersion. For processable modified or blended systems, layered injection molding or hot isostatic pressing followed by heat treatment can be used to achieve a similar gradient distribution.

[0051] In this embodiment, after sintering and cooling to room temperature, the blank is subjected to CNC precision machining to achieve key geometric tolerances such as throat diameter (e.g., ±0.05 mm). After surface cleaning, non-destructive testing, porosity measurement, and interlayer peeling test are performed to verify the consistency of the preparation, thereby obtaining the original nozzle part. Subsequently, the original nozzle component undergoes activation and enhancement treatments to improve interfacial bonding strength and resistance to arc erosion. The activation treatment includes plasma surface activation (exemplary parameters: inert or oxygen-containing working fluid, power 50–300 W, treatment 30–600 s) or chemical grafting to introduce reactive groups. The enhancement treatment includes low-temperature chemical infiltration (such as sol-gel infiltration or silicone coupling agent impregnation and curing at no more than 200 °C) to form bonding and passivation layers between layers and on the surface, coating the outer surface with a thin layer of ceramic sol or functional film to improve ablation resistance and optical reflection properties, and installing thermally expandable metal support rings as needed in high-stress areas such as the throat, and setting a thin ceramic or high-temperature insulating layer between the support ring and the composite and using compatible bonding or mechanical fastening methods to prevent electrical breakdown.

[0052] In this embodiment, the content of filler powder in each candidate partition is determined according to the material distribution table, and the mold cavity is filled in layers according to the partition order. The nozzle part is prepared by multi-stage hot pressing solid-state sintering, slow cooling and CNC precision machining, and subsequent activation and reinforcement treatment. By realizing the partition filler content and layering process according to the design, and by using controlled hot pressing and post-processing, the material gradient and interface quality obtained by simulation optimization can be faithfully reproduced in the physical part. This ensures that the selected partition scheme can realize the transient pressure build-up behavior predicted in the design on the actual part, and can improve the interlayer bonding and overall material strength through optimized densification and interface activation processes, thereby reducing the risk of interface degradation and early failure caused by repeated fractures.

[0053] In this embodiment, the thermo-mechanical-chemical coupling behavior and cumulative breaking life of the prepared composite modified PTFE gradient partition nozzle under real electric arc conditions are verified.

[0054] In this embodiment, the sample was first characterized macroscopically and microscopically using scanning electron microscopy and X-ray CT (X-ray computed tomography). Image processing and quantitative analysis were then used to extract indicators such as filler cluster density, interlayer interface thickness, and void volume fraction in each zone to assess the consistency between the preparation results and the microscopic parameters set in the numerical simulation. Thermogravimetric analysis and differential scanning calorimetry were used to determine the decomposition initiation temperature, mass loss rate, and exothermic characteristics of the thermal decomposition and gas generation behavior. Pyrolysis, gas chromatography, and mass spectrometry were combined to analyze the gas-generating components and instantaneous gas generation rate. The obtained gas generation spectra and rate curves were compared with reactive molecular dynamics predictions to assess the gas generation mechanism and the risk of harmful products.

[0055] In this embodiment, the layered thermal conductivity and thermal diffusivity are measured using the laser flash method, and the measured layer-by-layer thermal conductivity is compared with the non-equilibrium molecular dynamics prediction layer by layer to correct the mapping function between the micro and macro scales. The mechanical and thermomechanical properties are evaluated under normal and high temperature conditions through linear expansion coefficient testing, three-point bending, compression and impact tests to assess load-bearing capacity and thermo-mechanical compatibility. Thermo-coupling durability tests are carried out on an electric arc simulation or in-situ heating platform to observe throat diameter evolution, interface crack initiation and propagation behavior.

[0056] In this embodiment, during the arc extinguishing bench test, the arc extinguishing success rate, peak pressure rise of the gas chamber, throat diameter change curve, and material degradation and mass loss curve were recorded under representative breaking conditions. The above key performance indicators were compared and verified with pure PTFE samples and homogeneous filler composite samples to demonstrate the advantages of the gradient partitioned material in instantaneous pressure build-up, suppression of throat deformation, and improvement of cumulative breaking life.

[0057] This invention provides a high-voltage gas circuit breaker nozzle, which is manufactured using the high-voltage gas circuit breaker nozzle preparation method described above; The nozzle body is provided with an ablation-resistant layer, a transition layer and a gas-generating layer in sequence along the axial or radial direction; the ablation-resistant layer, the transition layer and the gas-generating layer are distributed in a gradient according to the partition order, and a gradient transition zone is provided between adjacent layers.

[0058] In this embodiment, the nozzle body of the high-voltage gas circuit breaker nozzle is provided with an ablation-resistant layer, a transition layer and a gas-generating layer in a partitioned order along the axial or radial direction. Each partition is spatially gradient distributed and a gradient transition zone is provided between adjacent layers to achieve a smooth transition of performance and stress. Specifically, the ablation-resistant layer is placed on the side closer to the electric arc or in the inner layer. It adopts a composite system toughened and densified with high thermal conductivity and corrosion-resistant inorganic fillers to obtain high density, low evaporation rate and excellent thermomechanical stability, thereby maintaining the geometric stability of the throat under long-term operation and high-temperature electric arc impact. The gas-generating layer is placed on the outer side or away from the electric arc. It adopts a composite matrix with controllable gas-generating organic additives and relatively high porosity to generate stable gas generation when heated and decomposed, thereby enhancing the instantaneous gas chamber pressure build-up and gas blowing effect. The intermediate transition layer is located between the two layers. It adopts an organic and inorganic composite formula and is designed to accommodate the differences between the two ends in terms of thermal conductivity, elastic modulus and porosity. Functionally, it is used to regulate thermal stress, improve interlayer bonding and inhibit delamination or crack initiation caused by thermo-mechanical mismatch.

[0059] In this embodiment, the geometry and physical properties of the gradient transition zone are controlled by design parameters (for example, the width of the transition zone can be set according to engineering needs and is preferably 0.5–2.0 mm), and are obtained through processes such as layered batching, pre-made masterbatch, partitioned filling of mold cavity and graded hot pressing, sintering or layered injection molding.

[0060] In this embodiment, to improve the interfacial bonding strength and durability, the filler can be surface-treated, and the interlayer interface can be activated by plasma, chemically grafted, or mechanically anchored. For the high-stress area in the throat, a thermally expandable metal support ring and a thin ceramic isolation layer can be used to limit radial expansion and prevent electrical breakdown. During short-term interruption, this nozzle structure enhances the gas chamber pressure rise through controlled gas production in the gas-producing layer, suppresses throat diameter increase through the high density of the ablation-resistant layer in the throat, and coordinates the thermodynamic response through the transition layer.

[0061] This invention sequentially comprises an ablation-resistant layer, a transition layer, and a gas-generating layer, distributed in a continuous or stepped gradient in the radial or axial direction, with a gradient transition zone between adjacent layers. This structure spatially distributes the "gas-generating function" and "ablation-resistant load-bearing" function to different layers and connects them with gradient transition zones. This allows the outer layer to quickly participate in transient pressure build-up, while the inner layer maintains high structural density and durability. The gradient transition zone helps alleviate interfacial stress caused by thermodynamic abrupt changes, thus simultaneously considering both short-term pressure build-up efficiency and the lifespan requirement of maintaining geometric and interfacial stability during repeated interruptions in the structural layout.

[0062] In this embodiment, the gas-generating layer is composed of an organic polymer material, and an organic gas-generating additive is dispersed in the gas-generating layer; the organic polymer material includes polytetrafluoroethylene and its modified system; the organic gas-generating additive includes one or more of fumaric acid, cyanuric acid and orotic acid.

[0063] In this embodiment, the gas-generating layer is composed of an organic polymer material as the matrix, preferably polytetrafluoroethylene (PTFE) and its modified system as the matrix phase, and organic gas-generating additives are dispersed in the matrix to form a gas-generating functional phase. The organic gas-generating additives can be one or more of fumaric acid, cyanuric acid, and orotic acid, and are prepared as gas-generating layer masterbatch by uniformly mixing them with PTFE / modified PTFE masterbatch in powder or microencapsulated form. The structure and formulation design of this gas-generating layer follows the principle of controlling the pyrolysis of the matrix under the action of electric arc high temperature to release electronegative or inert gases: on the one hand, by selecting appropriate types and contents of additives, and by using microencapsulation, surface modification, or nano or submicron dispersion technology, the uniform distribution and controlled release of additives in the PTFE matrix are achieved; on the other hand, by chemically or physically modifying PTFE to adjust the thermal decomposition temperature and porosity of the matrix, the gas generation initiation temperature and instantaneous gas generation rate are controlled, ensuring that the gas generation efficiency is sufficient to enhance the instantaneous gas chamber pressure build-up and gas blowing effect without causing excessive pressure fluctuations inside the nozzle.

[0064] Please refer to Figure 2 and Figure 3 , Figure 2 This is a schematic diagram of the structure of an inorganic packing material provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of the structure of an organic additive provided in an embodiment of the present invention.

[0065] In this embodiment, the ablation-resistant layer is composed of an inorganic ceramic matrix composite material, which includes one or more of alumina (Al2O3), silicon nitride (Si3N4) and / or silicon carbide (SiC). The sintering density and crack propagation can be improved by incorporating an appropriate amount of glass phase or metal oxide additives into the ceramic matrix, thereby obtaining an ablation-resistant structure with extremely low evaporation rate, high thermal stability and excellent mechanical strength under high-temperature arc impact.

[0066] In this embodiment, the inorganic ceramic matrix composite material refers to a multiphase composite material prepared by a densification process, such as batching, dispersion, molding, and high-temperature sintering or hot isostatic pressing, with the aforementioned ceramic as the main phase. The composite material may contain a finely dispersed phase or a glassy phase to fill the pores between particles and improve density and toughness. To improve the interfacial bonding with adjacent gas-generating layers or transition layers, the inorganic filler can undergo surface modification (e.g., coating with a coupling agent or surface activation) and a reasonable particle size distribution can be selected to balance densification and processability. In terms of process implementation, a controlled heating curve and heat preservation process are preferred to obtain an ablation-resistant layer with high density and low porosity. If necessary, a thin ceramic isolation layer or machined support structure can be set on the surface or between the ablation-resistant layer to enhance the geometric stability of the throat. This ablation-resistant layer exhibits low mass loss, low evaporation rate, and good thermomechanical stability in arc tests, thus effectively resisting ablation and maintaining the geometric integrity of the nozzle under long-term repeated interruption conditions.

[0067] In this embodiment, the transition layer is composed of an organic and inorganic composite system, which includes nano- or micron-sized ceramic particles uniformly dispersed in a resin matrix. The ceramic particles include one or more of alumina, aluminum nitride, silicon carbide, and zirconium oxide.

[0068] In this embodiment, the transition layer is composed of an organic and inorganic composite system, specifically a resin matrix in which nano- or micron-sized ceramic particles are uniformly dispersed. The ceramic particles can be selected from one or more of alumina (Al2O3), aluminum nitride (AlN), silicon carbide (SiC), and zirconium oxide (ZrO2) to balance toughness and thermal conductivity. The resin matrix (such as high-temperature modified epoxy, phenolic, or high-temperature engineering resin) provides the transition layer with elasticity and energy absorption capacity, which can relieve stress under thermal shock or mechanical load. The nano- or micron-sized ceramic particles improve local thermal conductivity and suppress heat concentration by increasing the heat conduction channels and enhancing the stiffness of the matrix, thereby mitigating local thermal stress caused by temperature gradient.

[0069] In this embodiment, to ensure good dispersion and interfacial bonding of ceramic particles in the resin matrix, it is preferable to perform surface modification on the ceramic particles, such as using silane coupling agents, phosphate coupling agents or plasma activation, and prepare a uniform composite slurry through processes such as ball milling, ultrasonication or high-speed dispersion; the composite slurry can be injected or cast into shape by vacuum impregnation or vacuum degassing, and then crosslinked and cured according to the set curing process to obtain a dense and uniform transition layer structure.

[0070] In this embodiment, the porosity of each functional layer of the high-voltage gas circuit breaker nozzle exhibits a decreasing gradient distribution according to the partition order. That is, the porosity of the gas-generating layer is greater than or equal to the porosity of the transition layer, and the porosity of the transition layer is greater than or equal to the porosity of the ablation-resistant layer. The gas-generating layer needs relatively high porosity to facilitate the pyrolysis and gas release of the organic gas-generating components, enhancing instantaneous gas chamber pressure build-up and the gas blowing effect. The transition layer, acting as a buffer zone, has moderate porosity and density to balance gas-generating performance with thermodynamic matching and reduce interfacial stress concentration. The ablation-resistant layer requires the highest density (lowest porosity) to obtain excellent thermal conductivity, low evaporation rate, and mechanical strength, thereby suppressing throat diameter increase and long-term degradation.

[0071] In this embodiment, the porosity gradient is precisely controlled by process parameters such as the filler content and particle size in the masterbatch, masterbatch pre-compression (e.g., initial compression of 0.5–5 MPa), interlayer filling sequence, multi-stage hot pressing and sintering curves and holding time, and interlayer interface treatment (plasma activation, surface grafting, etc.). The width of the transition zone is preferably 0.5–2.0 mm to balance functional transition and stress dispersion.

[0072] In this embodiment, to ensure verifiability and repeatability, X-ray CT tomographic reconstruction, scanning electron microscopy (SEM) combined with image analysis, mercury infiltration method or gas adsorption pore size distribution test are used to quantitatively characterize the porosity of each zone. The measured porosity is used as the input parameter in scale bridging and coupled simulation to evaluate the impact of porosity distribution on instantaneous pressure build-up, local heat flux, interfacial stress and repeated breaking life, and optimize the material formulation and process parameters accordingly.

[0073] In this embodiment, the selection of inorganic and organic filler materials was precisely designed: organic filler materials are represented by polyimide or modified epoxy, which are suitable as candidate materials for gas-generating layer matrix due to their excellent thermal stability and controllable decomposition characteristics; inorganic filler materials are preferably high thermal conductivity ceramic particles (such as aluminum nitride, beryllium oxide, etc.) to significantly improve local heat dissipation capacity and reduce thermal stress concentration.

[0074] In this embodiment, to ensure the uniformity of the material and the quality of interlayer bonding, good dispersion and interfacial bonding are achieved by controlling the particle size and distribution and adopting appropriate surface treatment measures during the composite preparation process. Specifically, the nozzle sample is prepared using a layered pressing and high-temperature curing process: the masterbatch of each zone is layered and molded according to the design. The gas-generating layer is exemplarily formulated with polytetrafluoroethylene (PTFE) as the matrix and a certain proportion of carbon powder is added to control the decomposition rate. The additives are uniformly distributed through molding. The intermediate transition layer is exemplarily a composite system of epoxy resin matrix and alumina micron particles. The particles are uniformly dispersed through vacuum impregnation. The ablation-resistant layer is exemplarily a dense layer obtained by hot pressing and sintering silicon carbide ceramic powder and is integrally formed with the intermediate layer.

[0075] Please refer to Figure 4 , Figure 4 A cross-sectional schematic diagram of a high-voltage gas circuit breaker nozzle provided in an embodiment of the present invention.

[0076] In this embodiment, the nozzle is arranged sequentially from the inside to the outside along the jet axis as follows: a gas-generating layer, an intermediate transition layer, and an erosion-resistant layer. The gas-generating layer shown in the figure is located near the nozzle cavity (i.e., the side closest to the arc or plasma). When subjected to the high temperature of the electric arc at the moment of circuit breaker breaking, it preferentially undergoes controlled thermal decomposition and gas generation to temporarily replenish steam in the gas chamber, enhance the instantaneous gas pressure rise, and generate directional gas blowing, thereby assisting in plasma cooling and arc extinguishing. The intermediate transition layer is located between the gas-generating layer and the erosion-resistant layer, with a transition zone width designed to be 0.5 mm to 2.0 mm, to mitigate the difference in thermomechanical properties between the two layers and disperse thermal stress. The erosion-resistant layer is located near the throat / outer side and employs a high thermal conductivity, corrosion-resistant ceramic matrix composite system to improve heat dissipation and geometric stability, suppressing throat diameter increase and deformation during repeated breaking processes, thereby improving the cumulative breaking life.

[0077] Please refer to Figure 5 , Figure 5 This is a schematic diagram illustrating the coordinated control of nozzle ablation gas production in an embodiment of the present invention.

[0078] In this embodiment, Figure 5 The upper middle section is the "upper" cavity area, the central section is the "larynx" restricted segment, and the lower section is the "downstream" diffusion area. Figure 5The vertical gradient arrows (from "weak" to "strong" from top to bottom) indicate the trend of the flow field intensity (local velocity and flow fluctuations and airflow energy) concentrating and increasing axially from upstream to the throat. The horizontal arrows in the figure indicate the local thermal shock effect of the electric arc or the direction of the electric arc on the throat sidewall (local high-temperature irradiation / ablation caused by the electric arc oscillating near the sidewall or in the near-throat region). The throat is shown with a dashed box, which is the most sensitive structural control section of the nozzle. Even a small increase in the throat diameter will significantly reduce the gas chamber pressure build-up efficiency and worsen the repeated interruption life.

[0079] In this embodiment, when an electric arc forms near the cavity sidewall or arc-side region during the interruption process and heats the inner surface of the nozzle, the gas-generating layer near the arc surface preferentially undergoes controlled thermal decomposition, releasing low-molecular-weight gases and replenishing the chamber gas volume in a short timescale, resulting in a momentary increase in the pressure gradient and flow velocity from upstream to the throat. This short-term "gas source" provided by the gas-generating layer, in conjunction with the contracting throat formed by the nozzle geometry, generates directional high-kinetic-energy gas blowing, enhancing the cooling and mechanical extrusion effect on the plasma, thereby promoting arc extinction. At the same time, the throat and outer side are covered with an ablation-resistant layer to ensure resistance to local high temperature and high erosion under continuous or repeated interruption conditions, suppressing throat diameter expansion and structural deformation, and maintaining long-term geometric stability.

[0080] Please refer to Figure 6 , Figure 6 This is a schematic diagram of the transient flow field profile of a nozzle provided in an embodiment of the present invention.

[0081] In this embodiment, Figure 6 The diagram provides transient flow field profiles of the nozzle at two different moments during the arcing stage. The arrows in the diagram indicate the gas flow direction, and the colors represent scalar contour plots of the velocity field / flow intensity. The upper and lower diagrams correspond to the early moment (t1, when the arc has just formed and begins to interact with the inner wall of the nozzle) and the later moment (t2, after the arc has developed and shifted or oscillated to the right / outside of the cavity) during the interruption process, respectively.

[0082] In this embodiment, upstream of the nozzle (i.e. Figure 6 The white cavity area on the right side of the middle (close to the gas chamber) interacts most intensely with the electric arc during the entire arc combustion process. The electric arc heat, irradiation, and chemical reactions cause this area to have the greatest demand for short-term gas production.

[0083] In this embodiment, the middle reaches of the nozzle, i.e., the throat (i.e. Figure 6 The white platform protruding downward in the middle and its downstream contraction section are the limiting throttling section. Its inner diameter (throat diameter) is extremely sensitive to the pressure build-up efficiency and arc extinguishing effect of the gas chamber. Small changes in the throat diameter will significantly affect the instantaneous pressure rise and subsequent gas blowing capacity. Therefore, this section must maintain geometric stability and avoid excessive ablation.

[0084] In this embodiment, at time t1, the airflow converges in front of the throat and generates an acceleration zone and local vortex below the platform (see light green and yellow areas); during this stage, the gas-producing layer begins to decompose thermally, delivering additional gas to the throat, causing a sudden increase in momentum and pressure from upstream to the throat; In this embodiment, at time t2, the arc further evolves or shifts, and stronger disturbances and localized backflow appear on the right side of the cavity (see...). Figure 6 (Deep blue vortex in the lower middle or right side). If the throat material is not resistant to ablation, the inner wall of the throat will be subjected to higher thermal erosion and chemical corrosion at this stage, resulting in an increase in throat diameter and a decrease in air chamber pressure building efficiency.

[0085] In this embodiment, firstly, a candidate material list and initial configuration parameters are obtained, and a model is constructed at the atomic, molecular, and interface scales. Molecular dynamics calculations are then used to obtain the first physical property parameters, which quantify physical quantities affecting instantaneous gas generation and interface durability at the microscopic level, such as gas generation rate and reaction kinetics, interfacial bonding and interfacial mechanical response. Subsequently, these first physical property parameters are bridged and mapped to second physical property parameters at a preset scale, and a transient coupling model is established, allowing the microscopic characterization to be computably reflected in the macroscopic transient state. Based on this transient coupling model, simulations are performed on several preset gradient schemes to obtain performance parameters, thereby selecting candidate partitioned gradient schemes that include a gas-generating layer, a corrosion-resistant burning layer, and a transition layer. This allows for direct comparison and weighing of the impact of different partition material distributions on two types of performance: "short-term pressure build-up response" and "cumulative damage and interface degradation rate" during the scheme selection phase. Finally, the parts are prepared in layers in the mold cavity according to the selected partition order and material distribution table, and the original parts are activated and enhanced. This allows the material gradient and interface conditions obtained from simulation optimization to be reproduced and strengthened in the solid parts. This ensures that the nozzle has the expected rapid pressure build-up and gas production capabilities in the transient phase of the break, and improves the durability during repeated break processes through interlayer bonding and material density obtained through engineered manufacturing and interface treatment. This helps to achieve a verifiable and manufacturable trade-off and optimization between transient pressure build-up efficiency and long-term break life.

[0086] In this embodiment, a high-voltage gas circuit breaker nozzle is provided. The gas-generating layer on the arc side achieves controllable gas generation and directional gas blowing at the moment of interruption by precisely incorporating controllable gas-generating organic additives into the PTFE matrix, significantly enhancing the instantaneous pressure build-up and arc-extinguishing capabilities of the gas chamber. Secondly, the high thermal conductivity and ablation-resistant composite layer at the throat or outer side effectively improves thermal diffusion and inhibits surface deformation and throat diameter increase, thereby maintaining throat geometric stability and reducing performance degradation after repeated interruptions. Thirdly, the intermediate transition zone alleviates the differences in thermomechanical properties between layers, reduces the risk of internal stress concentration and interlayer delamination, and improves the overall structural reliability. Furthermore, this invention achieves an engineering compromise between "short-term gas generation rate—long-term ablation rate—interfacial bonding energy—thermal conductivity" through multi-scale simulation and multi-objective optimization using Materials Studio / COMPASS, LAMMPS (NEMD / ReaxFF), NSGA-II, and COMSOL thermo-mechanical-fluid coupled response surfaces, ensuring the repeatability of the formulation and the feasibility of process scale-up. Finally, by adopting a process route involving layered masterbatch preparation, multi-stage hot pressing, and plasma surface activation, industrial-scale preparation and strict quality control were achieved. After verification by SEM, X-ray CT, TGA / GC-MS, laser flash thermal conductivity testing, and arc bench testing, it exhibited higher instantaneous pressure build-up capability, smaller throat diameter loss, and significantly extended cumulative breaking life under environmentally friendly gas conditions such as C4F7N / CO2, thus meeting the dual requirements of arc extinguishing efficiency and long-term reliability for practical large-capacity breaking devices.

[0087] In this embodiment of the invention, a terminal device is also provided, including a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor. When the processor executes the computer program, it implements the above-described high-voltage gas circuit breaker nozzle preparation method.

[0088] In this embodiment of the invention, a computer-readable storage medium is also provided, which includes a stored computer program, wherein the computer program controls the device where the computer-readable storage medium is located to execute the above-described high-voltage gas circuit breaker nozzle preparation method when it is running.

[0089] For example, a computer program can be divided into one or more modules, one or more of which are stored in memory and executed by a processor to perform the present invention. The one or more modules 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.

[0090] The terminal device may be a desktop computer, laptop, handheld computer, or cloud server, etc. The terminal device may include, but is not limited to, a processor, memory, and display. Those skilled in the art will understand that the above components are merely examples of terminal devices and do not constitute a limitation on the terminal device. It may include more or fewer components, or combinations of certain components, or different components. For example, the terminal device may also include input / output devices, network access devices, buses, etc.

[0091] The processor 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. The processor is the control center of the terminal device, connecting all parts of the terminal device through various interfaces and lines.

[0092] Memory can be used to store computer programs and / or modules. The processor implements various functions of the terminal device by running or executing the computer programs and / or modules stored in the memory, and by accessing data stored in the memory. Memory can mainly include a program storage area and a data storage area. The program storage area can store the operating system, application programs required for at least one function (such as sound playback, text conversion, etc.), etc.; the data storage area can store data created based on the use of the mobile phone (such as audio data, text message data, etc.). In addition, memory can include high-speed random access memory, and can also include non-volatile memory, such as hard disks, RAM, plug-in hard disks, smart media cards (SMC), secure digital cards (SD cards), flash cards, at least one disk storage device, flash memory device, or other volatile solid-state storage devices.

[0093] In this invention, if the module for preparing the nozzle of a high-voltage gas circuit breaker 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, all or part of the processes in the above embodiments of the present invention can also be implemented by a computer program instructing related hardware. The computer program can be stored in a computer-readable storage medium, and when executed by a processor, it can implement the steps of the various method embodiments described above. The computer program includes computer program code, which can be in the form of source code, object code, executable files, or certain intermediate forms. The computer-readable medium can include: any entity or device capable of carrying computer program code, recording media, USB flash drives, portable hard drives, magnetic disks, optical disks, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signals, telecommunication signals, and software distribution media, etc. Those skilled in the art can understand and implement this invention without any inventive effort.

[0094] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the scope of protection of the present invention. In particular, it should be noted that any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention for those skilled in the art.

Claims

1. A method for preparing a high-voltage gas circuit breaker nozzle, characterized in that, include: Obtain a list of candidate materials and initial configuration parameters; construct molecular and interface atomic models based on the list of candidate materials and initial configuration parameters; and calculate the first physical property parameters based on the molecular and interface atomic models and molecular dynamics. The first physical property parameter is mapped to the second physical property parameter based on the preset scale bridging method, and a transient coupling model is established based on the second physical property parameter; Gradient structure simulation is performed based on the transient coupling model and a preset gradient scheme to obtain the performance parameters corresponding to the preset gradient scheme. Candidate partitioning gradient schemes are then obtained based on these performance parameters. Each candidate partitioning gradient scheme includes several candidate partitions, a partitioning order, and a material distribution table corresponding to each candidate partition. Each candidate partition includes a gas-generating layer, a corrosion-resistant scorching layer, and a transition layer. Based on the partitioning sequence, the gas-generating layer, corrosion-resistant burning layer, and transition layer are set in the mold cavity. Based on the material distribution table corresponding to each candidate partition, the original nozzle part is prepared in the mold cavity. The original nozzle part is then activated and enhanced to obtain the high-voltage gas circuit breaker nozzle.

2. The method for preparing a high-voltage gas circuit breaker nozzle as described in claim 1, characterized in that, The steps of obtaining a candidate material list and initial configuration parameters, constructing molecular and interface atomic models based on the candidate material list and initial configuration parameters, and calculating first physical property parameters based on the molecular and interface atomic models and molecular dynamics include: Obtain a candidate material list and initial configuration parameters. The candidate material list includes alternative matrix materials, functional fillers, and interface modifiers and their characterization indicators. The initial configuration parameters include the number of nozzle partitions, the geometry of each partition, the target operating temperature and pressure range, and the target porosity. Based on the candidate material list and initial configuration parameters, molecular unit models and functional filler atomic models are constructed, and interface atomic models are assembled at the atomic scale according to the initial configuration parameters. Molecular and interface atomic models are constructed based on the molecular unit model and the interface atomic model. The first physical property parameters are calculated based on the molecular and interface atomic model and molecular dynamics.

3. The method for preparing a high-voltage gas circuit breaker nozzle as described in claim 2, characterized in that, The calculation of the first physical property parameters based on the molecular and interface atomic model and molecular dynamics includes: The molecular and interface atomic models are preprocessed based on a preset potential energy function to obtain the target molecular and interface atomic models; Based on molecular dynamics, equilibrium simulation and production-state molecular dynamics (MD) operation simulation were performed on the target molecule and interface atomic model to obtain the production-state MD trajectory. Based on the production-state MD trajectory, the interface binding energy, interface diffusion coefficient, local thermal conductivity or thermal interface thermal conductivity, elastic modulus and stress-strain response, interface fracture energy, gas production rate and reaction activation energy are calculated to generate the first physical property parameters.

4. The method for preparing a high-voltage gas circuit breaker nozzle as described in claim 3, characterized in that, The step of mapping the first physical property parameter to a second physical property parameter based on a preset scale bridging method, and establishing a transient coupling model based on the second physical property parameter, includes: The first physical property parameter is mapped to the second physical property parameter based on a preset scale bridging method; The second physical property parameters are used to generate a material property table based on a preset format, and a transient coupled model is constructed based on the material property table as unit properties and domain properties.

5. The method for preparing a high-voltage gas circuit breaker nozzle as described in claim 4, characterized in that, The process involves performing gradient structure simulation based on the transient coupling model and a preset gradient scheme to obtain performance parameters corresponding to the preset gradient scheme, and then obtaining candidate partition gradient schemes based on these performance parameters. The candidate partition gradient schemes include several candidate partitions, a partitioning order, and a material distribution table corresponding to each candidate partition, including: Several gradient schemes are preset, and simulations are performed on the transient coupling model based on these schemes to obtain material gas generation and heat transfer parameters, as well as mechanical and interface parameters. A multi-objective optimization algorithm is constructed based on the gas generation and heat transfer parameters of the material, as well as the mechanical and interface parameters. The algorithm is then used to perform transient solutions for each gradient scheme under preset multiple operating conditions to obtain the optimal candidate partition gradient scheme.

6. The method for preparing a high-voltage gas circuit breaker nozzle as described in claim 5, characterized in that, The process involves setting the gas-generating layer, corrosion-resistant sintering layer, and transition layer within the mold cavity based on the partitioning sequence, preparing the original nozzle component within the mold cavity based on the material distribution table corresponding to each candidate partition, and performing activation and enhancement treatments on the original nozzle component to obtain a high-voltage gas circuit breaker nozzle, including: Based on the aforementioned partitioning sequence, the gas-generating layer, the corrosion-resistant sintering layer, and the transition layer are disposed within the mold cavity; Based on the material distribution table, the filler content of the masterbatch powder in each zone of the gas-generating layer, corrosion-resistant burning layer, and transition layer is determined, and the masterbatch powder in each zone is filled into the corresponding area of ​​the mold cavity based on the filler content of each zone; The mold cavity is subjected to multi-stage hot pressing solid-state sintering, slow cooling, and CNC precision machining to obtain the original nozzle part; The original nozzle component is activated and enhanced to obtain a high-voltage gas circuit breaker nozzle.

7. A high-voltage gas circuit breaker nozzle, comprising a nozzle body; characterized in that the high-voltage gas circuit breaker nozzle is manufactured using a high-voltage gas circuit breaker nozzle manufacturing method as described in any one of claims 1 to 6; The nozzle body is provided with an ablation-resistant layer, a transition layer and a gas-generating layer in sequence along the axial or radial direction; the ablation-resistant layer, the transition layer and the gas-generating layer are distributed in a gradient according to the partition order, and a gradient transition zone is provided between adjacent layers.

8. A high-voltage gas circuit breaker nozzle as described in claim 7, characterized in that, The gas-generating layer is composed of organic polymer materials, and organic gas-generating additives are dispersed in the gas-generating layer; the organic polymer materials include polytetrafluoroethylene and its modified systems; the organic gas-generating additives include one or more of fumaric acid, cyanuric acid and orotic acid.

9. A high-voltage gas circuit breaker nozzle as described in claim 8, characterized in that, The ablation-resistant layer is composed of an inorganic ceramic matrix composite material, which includes one or more of alumina, silicon nitride, and silicon carbide.

10. A high-voltage gas circuit breaker nozzle as described in claim 7, characterized in that, The transition layer is composed of an organic and inorganic composite system, which includes nano- or micron-sized ceramic particles uniformly dispersed in a resin matrix. The ceramic particles include one or more of alumina, aluminum nitride, silicon carbide, and zirconium oxide.

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