Method and device for determining gas cavity of gas sensor, electronic equipment and storage medium

Abstract

The invention provides a method and a device for determining a gas cavity of a gas sensor, electronic equipment and a storage medium, and relates to the technical field of gas sensors. The time required by the target gas to reach the uniform concentration distribution state in the gas cavity models of different inlet and outlet structures is determined through analog simulation, so that the inlet and outlet structure with the shortest time consumption is screened out. The stability of the gas sensor is guaranteed by taking gas uniform distribution as a limiting condition, and the response speed of the gas sensor is guaranteed by optimizing the time consumption for achieving uniform distribution. Model simulation and gas cavity inlet and outlet structure optimization are combined, the gas cavity capable of accelerating uniform distribution of gas is conveniently and efficiently determined at low cost, and therefore the response speed and stability of the gas sensor are improved.

Description

Technical Field

[0001] The present application relates to the technical field of gas sensors, and in particular to a method, device, electronic device and storage medium for determining a gas cavity of a gas sensor. Background Art

[0002] The air cavity plays a vital role in the gas sensor, which directly affects the performance and response characteristics of the sensor. The design optimization of the air cavity can improve the sensitivity, response speed and stability of the sensor. A suitable air cavity design can ensure that the gas can be fully diffused and evenly distributed in the sensitive area of ​​the sensor, thereby improving the detection sensitivity and accuracy of the sensor.

[0003] Therefore, how to provide a more convenient and efficient solution for the optimal design of the gas cavity of the gas sensor has become an urgent problem to be solved. Summary of the invention

[0004] Based on this, it is necessary to provide a method, device, electronic device and storage medium for determining the air cavity of a gas sensor in response to the above-mentioned technical problems, so as to provide a more convenient and efficient solution for the optimized design of the air cavity of the gas sensor.

[0005] A method for determining an air cavity of a gas sensor, the method comprising: based on a candidate air cavity model, simulating the gas concentration distribution of a target gas entering the candidate air cavity model to obtain the time taken for the gas concentration of the target gas to reach a uniform distribution state; determining the target air cavity model with the shortest time consumption from different candidate air cavity models, wherein different candidate air cavity models are provided with different inlet and outlet structures; the target air cavity model is used to determine the air cavity of the gas sensor.

[0006] In some embodiments, based on the candidate air cavity model, the gas concentration distribution simulation is performed on the target gas entering the candidate air cavity model to obtain the time taken for the gas concentration of the target gas to reach a uniform distribution state, including: based on a preconfigured physical field interface, preconfigured boundary conditions and initial conditions, the gas concentration of the target gas entering the candidate air cavity model is transiently calculated to obtain a transient calculation result of the gas concentration, the preconfigured physical field interface being used to simulate the flow and heat transfer process of the target gas in the candidate air cavity model; based on the transient calculation result, the time taken for the gas concentration of the target gas to reach a uniform distribution state in the candidate air cavity model is determined.

[0007] In some embodiments, the inlet and outlet structures of the candidate air cavity model include: the inlet and outlet are arranged in parallel on the same side of the air cavity body, the inlet and outlet are arranged on both sides of the air cavity body and form a right angle, and the inlet and outlet are arranged on both sides of the air cavity body and form a right angle.

[0008] In some embodiments, the physics interfaces include: a Non-Isothermal Flow interface, a Turbulent Reflected Flow interface, and a Transport of Diluted Species interface.

[0009] In some embodiments, based on the preconfigured physical field interface, preconfigured boundary conditions and initial conditions, the gas concentration of the target gas entering the candidate air cavity model is transiently calculated to obtain the transient calculation result of the gas concentration, including: calling the non-isothermal flow interface, the turbulent reaction flow interface and the dilute species transfer interface to perform multi-physical field coupling, and respectively obtaining the momentum equation, energy equation and transfer equation of the target gas as equations to be solved in the transient solver; referring to the boundary conditions and initial conditions, executing the transient solver to obtain the transient calculation result.

[0010] In some embodiments, the candidate air cavity model is a three-dimensional finite element model, the finite elements of the preset calculation area in the finite element model are obtained based on hexahedral structured grid division, and the finite elements of the preset non-calculation area in the finite element model are obtained based on tetrahedral structured grid division.

[0011] In some embodiments, the boundary conditions include: the position of the air cavity inlet, the position of the air cavity outlet, the flow rate of the target gas at the air cavity inlet, the pressure at the air cavity outlet, and the ambient temperature.

[0012] A device for determining an air cavity of a gas sensor comprises: a simulation module for simulating the gas concentration distribution of a target gas entering the candidate air cavity model based on a candidate air cavity model, and obtaining the time taken for the gas concentration of the target gas to reach a uniform distribution state; a determination module for determining the target air cavity model with the shortest time consumption from different candidate air cavity models, wherein different candidate air cavity models are provided with different inlet and outlet structures; the target air cavity model is used to determine the air cavity of the gas sensor.

[0013] In some embodiments, the simulation module is used to: perform transient calculation of the gas concentration of the target gas entering the candidate air cavity model based on a preconfigured physical field interface, preconfigured boundary conditions and initial conditions to obtain a transient calculation result of the gas concentration, wherein the preconfigured physical field interface is used to simulate the flow and heat transfer process of the target gas in the candidate air cavity model; based on the transient calculation result, determine the time it takes for the gas concentration of the target gas to reach a uniform distribution state in the candidate air cavity model.

[0014] In some embodiments, the inlet and outlet structures of the candidate air cavity model include: the inlet and outlet are arranged in parallel on the same side of the air cavity body, the inlet and outlet are arranged on both sides of the air cavity body and form a right angle, and the inlet and outlet are arranged on both sides of the air cavity body and form a right angle.

[0015] In some embodiments, the physics interfaces include: a Non-Isothermal Flow interface, a Turbulent Reflected Flow interface, and a Transport of Diluted Species interface.

[0016] In some embodiments, the simulation module is used to: call the non-isothermal flow interface, the turbulent reaction flow interface and the dilute species transfer interface to perform multi-physics field coupling, and obtain the momentum equation, energy equation and transfer equation of the target gas respectively as equations to be solved in the transient solver; refer to the boundary conditions and initial conditions, execute the transient solver, and obtain the transient calculation results.

[0017] In some embodiments, the candidate air cavity model is a three-dimensional finite element model, the finite elements of the preset calculation area in the finite element model are obtained based on hexahedral structured grid division, and the finite elements of the preset non-calculation area in the finite element model are obtained based on tetrahedral structured grid division.

[0018] In some embodiments, the boundary conditions include: the position of the air cavity inlet, the position of the air cavity outlet, the flow rate of the target gas at the air cavity inlet, the pressure at the air cavity outlet, and the ambient temperature.

[0019] An electronic device comprises a memory, a processor and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the steps of the method for determining the gas cavity of the gas sensor as described in any of the above embodiments are implemented.

[0020] A computer-readable storage medium stores a computer program, which, when executed by a processor, implements the steps of the method for determining the gas cavity of a gas sensor as described in the above embodiment.

[0021] In summary, the present application proposes a method, device, electronic device and storage medium for determining the air cavity of a gas sensor. The present application considers the influence of different inlet and outlet structures on the gas flow rate and flow direction, and analyzes the relationship between the change in the position of the air cavity inlet and outlet and the gas concentration distribution in the air cavity through model simulation. This method constructs an air cavity simulation model with different inlet and outlet structures, and determines the time required for the target gas to reach a uniform concentration distribution state in the air cavity model with different inlet and outlet structures through simulation, so as to screen out an inlet and outlet structure with the shortest time consumption. The uniform distribution of gas is used as a limiting condition to provide a guarantee for the stability of the gas sensor, and the time consumption to achieve uniform distribution is optimized to provide a guarantee for the response speed of the gas sensor. The present application combines model simulation with the optimization of the air cavity inlet and outlet structure, and determines the air cavity that can accelerate the uniform distribution of gas at a low cost, conveniently and efficiently, thereby improving the response speed and stability of the gas sensor. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative labor.

[0023] Figure 1 is a flow chart of a method for determining a gas cavity of a gas sensor according to an exemplary embodiment of the present application; Figure 2 is a schematic diagram of a candidate air cavity model according to an exemplary embodiment of the present application; Figure 3 is a schematic diagram of a candidate air cavity model according to another exemplary embodiment of the present application; Figure 4 is a schematic diagram of a candidate air cavity model according to another exemplary embodiment of the present application; Figure 5 is a flow chart of a method for determining a gas cavity of a gas sensor according to an exemplary embodiment of the present application; Figure 6 is a flow chart of a method for determining a gas cavity of a gas sensor according to an exemplary embodiment of the present application; Figure 7 is a schematic block diagram of a device for determining a gas cavity of a gas sensor according to an exemplary embodiment of the present application; Figure 8 It is a schematic block diagram of an electronic device according to an exemplary embodiment of the present application. DETAILED DESCRIPTION

[0024] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. The embodiments described by reference to the drawings are exemplary and are intended to be used to explain the present application, and cannot be understood as limiting the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0025] It should be understood that when used in the present specification and the appended claims, the term "comprising" indicates the presence of described features, integers, steps, operations, but does not exclude the presence or addition of one or more other features, integers, steps, operations and / or groups thereof.

[0026] It should also be understood that the term "and / or" used in the present description and the appended claims refers to and includes any and all possible combinations of one or more of the associated listed items.

[0027] As used in the present specification and the appended claims, the term "if" may be interpreted as "when" or "upon" or "in response to determining" or "in response to detecting", depending on the context. Similarly, the phrase "if it is determined" or "if [described condition or event] is detected" may be interpreted as meaning "upon determination" or "in response to determining" or "upon detection of [described condition or event]" or "in response to detecting [described condition or event]", depending on the context.

[0028] In addition, in the description of the present specification and the appended claims, the terms "first", "second", "third", etc. are only used to distinguish the descriptions and cannot be understood as indicating or implying relative importance.

[0029] References to "one embodiment" or "some embodiments" etc. described in the present specification mean that one or more embodiments of the present invention include specific features, structures or characteristics described in conjunction with the embodiment. Therefore, the phrases "in one embodiment", "in some embodiments", "in some other embodiments", "in some other embodiments", etc. appearing in different places in this specification do not necessarily refer to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized in other ways. The terms "including", "comprising", "having" and their variations all mean "including but not limited to", unless otherwise specifically emphasized in other ways.

[0030] Adjusting the inlet and outlet positions of the gas cavity can adjust the flow path and speed of the gas flow in the cavity, thereby affecting the diffusion speed and distribution of the gas. For gas sensors inside the car, this means that changing the inlet and outlet positions may affect the sensor's detection sensitivity and response speed to pollutants in the environment. Positioning the inlet close to the sensor area may speed up the diffusion of the gas and increase the sensor's response speed, but it may also reduce the sensor's stability. Conversely, positioning the inlet away from the sensor area may increase the sensor's stability, but may cause a delay in the response time.

[0031] Therefore, this application uses simulation software to simulate the gas concentration distribution of air cavities with various inlet and outlet structures, so as to screen out air cavities that can facilitate rapid diffusion and uniform distribution of gas in the cavity. In this way, both the stability and response speed of the gas sensor are taken into account when optimizing the air cavity, and a convenient, efficient and low-cost solution is proposed for the optimization of the gas sensor air cavity.

[0032] Figure 1is a flow chart of a method for determining a gas cavity of a gas sensor according to an exemplary embodiment of the present application, such as Figure 1 As shown, the method comprises the following steps: S101, based on a candidate air cavity model, performing a gas concentration distribution simulation on a target gas entering the candidate air cavity model to obtain a time consumption for the gas concentration of the target gas to reach a uniform distribution state.

[0033] The gas sensor air cavity is modeled, a three-dimensional model is constructed, and then the positions of the air cavity inlet and the air cavity outlet in the model are changed to obtain multiple air cavity models with different inlet and outlet positions, namely the above-mentioned candidate air cavity models.

[0034] Each candidate air cavity model is used as the test object, a gas substance is selected as the target gas entering the candidate air cavity model, and the simulation software is used to simulate the distribution of the target gas after entering the candidate air cavity model from the air cavity inlet, such as simulating the concentration change of the target gas at various locations in the candidate air cavity model. Thus, the time required for the target gas to be evenly distributed in the air cavity model is determined through the simulation results, that is, the time required for the gas concentration of the target gas to be equal at various locations in the candidate air cavity model.

[0035] S102, determining the target air cavity model with the shortest time consumption from different candidate air cavity models, wherein different candidate air cavity models are provided with different inlet and outlet structures; the target air cavity model is used to determine the air cavity of the gas sensor.

[0036] According to the simulation results, the time taken for the gas concentration of the target gas to reach a uniform distribution state in different candidate air cavity models is obtained, and then from these candidate air cavity models, a candidate air cavity model with the shortest time consumption is determined as the target air cavity model.

[0037] The gas sensor cavity can be designed with reference to the shape, size, inlet and outlet structure and other features of the target cavity model. Alternatively, the gas sensor cavity can be directly produced according to the target cavity model. In practical applications, the gas entering the cavity can be evenly distributed in the cavity in a short time, and the gas concentration is equal everywhere, thereby shortening the response time of the gas sensor, improving the sensitivity, avoiding the fluctuation of the sensor acquisition data due to the difference in gas concentration at various locations, and improving the stability of the sensor.

[0038] For example, Figure 2 As shown in the figure, during simulation, an air cavity simulation model is built with the air cavity inlet and outlet on the same side. The air cavity volume can be set to about 350ml, and the bottom of the air cavity is a 10cm×10cm arc-shaped square with a height of 4cm. Inside the air cavity is a square PCB board with a side length of 4cm, on which a sensor is embedded. The screws used are 1.5cm long, 0.6cm in outer diameter, and 0.4cm in inner diameter.

[0039] After the model is established, the material of each component in the model can be further defined, for example, the air cavity is made of stainless steel, the substrate of the sensor is made of anisotropic single crystal silicon, and the heating material is made of polycrystalline silicon. Furthermore, ethanol C2H5OH is selected as the target gas. The present invention adjusts the inlet and outlet positions of the air cavity and analyzes the time required for the C2H5OH gas concentration in the air cavity with different inlet and outlet structures to reach uniform distribution, thereby selecting the best structure. In summary, this application considers the impact of different inlet and outlet structures on gas flow rate and flow direction, and analyzes the relationship between the change of the position of the air cavity inlet and outlet and the gas concentration distribution in the air cavity through model simulation. This method constructs an air cavity simulation model with different inlet and outlet structures, and determines the time required for the target gas to reach a uniform concentration distribution state in the air cavity model with different inlet and outlet structures through simulation, so as to screen out an inlet and outlet structure with the shortest time consumption. The uniform distribution of gas is used as a restriction condition to provide a guarantee for the stability of the gas sensor, and the time consumption to achieve uniform distribution is optimized to provide a guarantee for the response speed of the gas sensor. This application combines model simulation with the optimization of the air cavity inlet and outlet structure, and determines the air cavity that can accelerate the uniform distribution of gas at a low cost, conveniently and efficiently, thereby improving the response speed and stability of the gas sensor.

[0040] Based on the above embodiment, the inlet and outlet structures of the candidate air cavity model include but are not limited to any of the following: The inlet and outlet are arranged in parallel on the same side of the air cavity body, such as Figure 2 As shown, an inlet pipe and an outlet pipe parallel to each other are arranged on the same side of the regular air cavity body; The inlet and outlet are arranged on both sides of the air cavity body and present a straight angle, such as Figure 3 As shown, an inlet pipe and an outlet pipe are respectively arranged on two mutually parallel sides of the regular air cavity body, wherein the central axes of the inlet pipe and the outlet pipe are located on the same straight line, that is, a right angle is formed between the inlet pipe and the outlet pipe; The inlet and outlet are arranged on both sides of the air cavity body and present a right angle, such as Figure 4 As shown, an inlet pipe and an outlet pipe are respectively arranged on two mutually perpendicular sides of the regular air cavity body, so that a right angle is formed between the inlet pipe and the outlet pipe.

[0041] The differences in the inlet and outlet structures described in this application can be understood as: the differences in the relative position relationship between the inlet pipe and the outlet pipe. In this application, the change in the inlet and outlet structure is used as the only variable, that is, the size, shape and other parameters of the inlet and outlet pipes are guaranteed to be the same, and the influence of the inlet and outlet position setting on the time taken for the gas concentration to reach a uniform distribution state in the air cavity is studied, so as to be able to more clearly and accurately analyze the correspondence between the time taken for the gas concentration to be uniformly distributed and the inlet and outlet positions.

[0042] This application selects three different inlet and outlet structures, namely, the inlet and outlet are set in the same direction, the inlet and outlet are set in opposite directions, and the inlet and outlet are set vertically, to build multiple candidate air cavity models, and analyzes the relationship between the difference in the relative positions of the inlet and outlet pipes and the time required for uniform distribution of gas concentration in the air cavity.

[0043] Based on the above embodiments, Figure 5 As shown, in the above step S101, "based on the candidate air cavity model, simulating the gas concentration distribution of the target gas entering the candidate air cavity model to obtain the time taken for the gas concentration of the target gas to reach a uniform distribution state" includes: S501, based on a preconfigured physical field interface, preconfigured boundary conditions and initial conditions, performing transient calculation on the gas concentration of the target gas entering the candidate air cavity model to obtain a transient calculation result of the gas concentration, wherein the preconfigured physical field interface is used to simulate the flow and heat transfer process of the target gas in the air cavity of the candidate air cavity model; S502: Based on the transient calculation result, determine the time taken for the gas concentration of the target gas to reach a uniform distribution state in the candidate air cavity model.

[0044] The tester can pre-select the physical fields involved in the simulation in the simulation software, configure boundary conditions for the physical fields that need to be configured with boundary conditions, and configure boundary conditions and initial conditions for the entire candidate air cavity model.

[0045] The simulation software simulates the flow and heat transfer process of the target gas in the candidate air cavity model based on the selected physical field, preset boundary conditions and initial conditions, and calculates the gas concentration at various locations in the air cavity in real time during the process, thereby obtaining the transient calculation result of the gas concentration in the candidate air cavity model. For example, the transient calculation result can be a gas concentration distribution diagram in the candidate air cavity model at different times.

[0046] Based on the transient calculation results of the gas concentration, the time consumed from the start of the simulation to the uniform distribution of the gas concentration in the air cavity is determined, that is, the time consumed for the target gas to reach a uniform concentration distribution state in the candidate air cavity model is determined.

[0047] It is not difficult to understand that boundary conditions directly affect the boundary behavior of the simulation area, such as the inlet and outlet of the fluid, the application of temperature, the loading of force, etc. Reasonable selection and setting of boundary conditions can control the boundary behavior of the simulation area and avoid the influence of boundary effects on the simulation results. The physical field defines the basic physical properties and behaviors of the simulation problem. By properly setting the physical field, various physical phenomena and interactions of the problem can be simulated to ensure the authenticity and credibility of the simulation results. By reasonably designing boundary conditions and physical fields, physical phenomena and scenes in the real world can be accurately simulated, making the simulation results reliable and comparable.

[0048] In practice, the design of boundary conditions and physical fields needs to consider numerical stability and convergence to avoid numerical oscillation, divergence or numerical instability, and to ensure the reliability and accuracy of simulation results.

[0049] For example, when simulating the gas concentration distribution in the candidate gas cavity model based on the method for determining the gas sensor gas cavity proposed in this application, the solid and fluid heat transfer physics fields and the dilute species transfer physics fields can be selected in the simulation software, and the corresponding boundary conditions can be set. Under constant temperature conditions, the target gas is a compressible viscous fluid, and its flow characteristics are stable turbulent flow. Therefore, it is also necessary to select a turbulence model in a single-phase flow in the fluid flow physics field to simulate the reaction flow of the target gas. Furthermore, the gas inlet and outlet are defined in the simulation software, and the corresponding flow rate is set. Based on the concentration parameter in the driving equation corresponding to the dilute species transfer physics field, the concentration value of the target gas during the circulation process in the gas cavity is calculated.

[0050] Based on the above embodiments, the physical field may include but is not limited to: non-isothermal flow, turbulent reflected flow, dilute species transfer, and the like.

[0051] In some embodiments, the multiphysics interface and the transport of diluted species interface for non-isothermal flow and turbulent reflected flow fusion can be directly called in the solver, and then the multiphysics fusion can be performed on the called interface.

[0052] In other embodiments, the non-isothermal flow interface, the turbulent reactive flow interface, and the transport of diluted species interface may be called in the solver respectively, and then multi-physics field fusion may be performed.

[0053] Based on the above embodiments, Figure 6 As shown, in the above step S501, "based on the preconfigured physical field interface, the preconfigured boundary conditions and the initial conditions, the gas concentration of the target gas entering the candidate air cavity model is transiently calculated to obtain the transient calculation result of the gas concentration" may include the following steps: S601, calling the non-isothermal flow interface, the turbulent reaction flow interface, and the dilute species transport interface to perform multi-physics field coupling, and respectively obtaining the momentum equation, energy equation, and transfer equation of the target gas as equations to be solved in the transient solver; S602, referring to the boundary conditions and initial conditions, executing the transient solver to obtain the transient calculation result.

[0054] The embodiment of the present application can select the three physical fields of non-isothermal flow, reflected flow and dilute material transfer for coupling. In practical applications, the temperature of the fluid often changes with time and space, and this change will directly affect the physical properties of the fluid (such as density, viscosity, etc.), and then affect the flow characteristics of the fluid. Therefore, in order to more accurately simulate the actual flow process, it is necessary to consider non-isothermal flow. Secondly, in the process of dilute material transfer, the flow of the fluid is one of the main driving forces of material transfer, and the magnitude and direction of the flow velocity will directly affect the rate and path of material transfer. Therefore, when simulating the transfer of dilute materials, it is necessary to consider the influence of the flow velocity, that is, to couple the physical field of the dilute material with the reaction flow. Because the gas can be regarded as a compressible viscous fluid, its flow characteristics are manifested as a stable turbulent flow, so turbulence is selected as the reaction flow of the target gas, that is, a turbulent reaction flow.

[0055] In general, selecting non-isothermal flow, turbulent reaction flow, and diluted species transfer physics coupling when performing flow and heat transfer simulation in simulation software can more accurately simulate the actual flow and heat transfer process to obtain accurate simulation results.

[0056] In the simulation software, by coupling the non-isothermal flow with the dilute species transport, the following set of equations can be obtained: The momentum equation is a partial differential equation that describes the conservation of momentum in viscous fluids. In non-isothermal flows, it takes into account the effects of temperature on fluid properties such as density and viscosity, as well as the effects of natural convection due to temperature gradients. The momentum equation can be expressed as: Among them, ρ represents fluid density, u represents fluid velocity, p represents pressure, μ represents dynamic viscosity, F represents volume force (such as gravity), and T is the transpose sign of the vector. The Nabla operator is a vector differential operator.

[0057] The energy equation describes the change in energy (usually expressed as temperature) within the fluid, including energy transfer due to convection, conduction, and possible heat sources such as chemical reactions. In non-isothermal flows, the energy equation is often coupled with the momentum equation to account for the effect of the flow on the temperature distribution. The energy equation can be expressed as: Where ρ represents the fluid density, u represents the fluid velocity, and C p represents the specific heat capacity at constant pressure, p represents pressure, T represents temperature, q represents heat flux (given by Fourier's law), Indicates the heat generated per unit volume (such as chemical reaction heat), The Nabla operator is a vector differential operator.

[0058] The transport of diluted species equation (also called the convection-diffusion equation) describes the change in concentration of a solute in a fluid, including concentration gradients due to convection and diffusion: Where: c represents the concentration of the solute, u represents the fluid velocity, D represents the diffusion coefficient of the solute, and R represents the source term caused by chemical reactions, etc. The Nabla operator is a vector differential operator.

[0059] This application introduces the effect of solute concentration on fluid properties in the simulation by integrating non-isothermal flow, turbulent reaction flow and dilute material transfer physics, so as to more accurately describe the actual physical phenomena; at the same time, it introduces the nonlinear effects of temperature and concentration on fluid flow. For example, high-concentration solute areas may cause a significant increase in fluid viscosity, thereby affecting flow resistance and heat transfer efficiency; and it couples microscopic solute transfer with macroscopic fluid flow and heat transfer to study the effect of microstructures (such as porous media) on the overall transfer process. Overall, it enhances the simulation accuracy of the flow and heat transfer process of the target gas in the air cavity and improves the accuracy of the simulation results.

[0060] In practice, users can design the physical field interface in the simulation COMSOL, configure the boundary conditions and initial conditions of the physical field, further configure the solver parameters, and finally execute the solver to obtain the results of the gas concentration distribution simulation. For example, the parameter setting and execution of the solver may include the following steps: 1. Select the solver and switch to the "Study" module. Add a time-dependent study: Select "Transient" as the study type. This will allow for transient calculations of gas concentration distribution.

[0061] Set the time range: Start Time: Set the start time (usually 0). End Time: Set the end time (can be set as needed). Time Step: Set the time step (the initial time step can be small and gradually increase).

[0062] Configure solver parameters: Open the solver settings: In the "Study" module, right-click "SolverConfigurations" and select "Edit Solver Configuration". Set the time step control: InitialStep: Set the initial time step (for example, 0.01 seconds); Maximum Step: Set the maximum time step (for example, 0.1 seconds); Minimum Step: Set the minimum time step (for example, 1e -5 seconds). Set tolerance: Relative Tolerance: Set the relative tolerance (e.g. 1e -3). Absolute Tolerance: Sets the absolute tolerance (adjustable based on the magnitude of the variable).

[0063] Set iterative solution parameters: Set the maximum number of iterations and other iterative solution parameters to ensure convergence.

[0064] Run the solution: Click the "Compute" button to start the solution. Monitor the solution process: Observe the convergence curves and intermediate results to ensure that the solution is proceeding normally. If there are convergence problems, you can adjust the solver parameters or time step.

[0065] In finite element analysis, meshing is closely related to the accuracy of simulation results. In order to improve the calculation speed, this application uses meshes of different sizes for different parts of the model when meshing. At the same time, check the mesh quality before simulation to ensure that the mesh has no serious distortion or highly non-orthogonal units. In practice, the mesh density and unit size can be adjusted according to needs to optimize the mesh quality.

[0066] In one embodiment, the candidate air cavity model in the present application is a three-dimensional finite element model, and the finite elements of the preset calculation area in the finite element model are obtained based on hexahedral structured grid division, and the finite elements of the preset non-calculation area in the finite element model are obtained based on tetrahedral structured grid division.

[0067] For example: compared with the gas reaction chamber, the size of the pipe at the inlet and outlet is too small. In order to minimize the numerical error, control the number of mesh units in the calculation area, and speed up the convergence of the numerical calculation, the volume splitting method is used to separate the entire calculation area into several blocks when the calculation area is discretized. Structured grids are widely used because of the high quality and fast speed of the generated mesh, and the mesh model is more consistent with the actual model. In the embodiment of the present application, the air cavity is a regular rectangular parallelepiped geometric shape, so a structured grid is used. In general, hexahedral meshes are of higher quality than tetrahedral meshes and converge more easily, so hexahedral unit meshes are used for most submodules of the model, and tetrahedral meshes are used for meshing at the inlet and outlet connection parts of the pipeline.

[0068] Based on the above embodiment, the boundary conditions may include but are not limited to: the position of the gas cavity inlet, the position of the gas cavity outlet, the flow rate of the target gas at the gas cavity inlet, the pressure of the gas cavity outlet, and the ambient temperature. The initial conditions may include but are not limited to the initial temperature, initial pressure, and initial concentration distribution of the target gas.

[0069] For example, the inlet flow rate can be set to 0.66m / s and the ambient temperature to 20°C. Based on the concentration of ethanol in the laboratory, the molar concentration of C2H5OH is set to 4.8e-5mol / m 3The air inlet of the air cavity is set as the velocity inlet, the air outlet is set as the pressure outlet, and the outlet is set to 0.1MPa atmospheric pressure.

[0070] In order to clearly describe the method for determining the gas cavity of the gas sensor proposed in this application, the model building and simulation process of the gas cavity are combined for exemplary description: The following steps are usually involved in simulating the gas cavity model of a gas sensor in COMSOL Multiphysics: Establishing geometric model: First, you need to create a geometric model of the air cavity. You can use the geometric modeling tools provided by COMSOL or import external CAD files to build a 3D geometric model of the air cavity. Define the shape, size, and structure of the air cavity in the geometric model. The model is divided into structured grids to obtain a finite element air cavity model.

[0071] Define the materials of the components in the model.

[0072] Set the physical field: Select the appropriate physical field to describe the physical process in the air cavity. For the air cavity model of the gas sensor, fluid dynamics (CFD) and heat transfer (Heat Transfer) physical fields are usually involved. In COMSOL, users can select the required physical field module and set the corresponding physical parameters.

[0073] Define boundary conditions: Boundary conditions can include the location of the inlet and outlet of the gas cavity, the injection method of the gas sample, whether the boundary is fixed or moving, etc.

[0074] Set initial conditions: Before simulation, it is necessary to set the initial conditions of the gas cavity, such as the initial temperature, pressure and concentration distribution of the gas, etc. These initial conditions will affect the starting state and evolution process of the simulation.

[0075] Perform simulation calculations: After completing the setting of boundary conditions and initial conditions, simulation calculations can be performed through the solver in COMSOL Multiphysics. The solver will numerically solve the air cavity model based on the set physical fields, boundary conditions, and initial conditions, and obtain the response and performance of the gas sensor under different conditions.

[0076] Analysis results: After the simulation is completed, the simulation results can be analyzed and visualized through the post-processing tools provided by COMSOL Multiphysics. You can view relevant data such as gas concentration, temperature distribution, flow velocity field, and evaluate and optimize the performance of the gas sensor.

[0077] This application determines the time required for the target gas to reach a uniform distribution of gas concentration in the air cavity model by focusing on the gas concentration information in the simulation results. Similarly, the above model building and simulation process is repeated for air cavities with different inlet and outlet structures to obtain the time required for the target gas to reach a uniform distribution of gas concentration in air cavity models with different inlet and outlet structures. Table 1 shows the time required for the gas concentration to reach a uniform distribution in three air cavities with different inlet and outlet position settings.

[0078] Table 1 Correspondence between the position of the gas cavity inlet and outlet and the time required for the gas concentration to reach uniform distribution The air cavity model with the shortest time consumption and uniform distribution of gas concentration is selected. The structure of the air cavity model can be used as a reference to design the air cavity in the gas sensor.

[0079] In summary, this application simulates a variety of air cavity models with different inlet and outlet structures to select the air cavity with the best inlet and outlet structure, thereby minimizing the time required for uniform distribution of gas concentration in the air cavity of the gas sensor. Traditionally, air cavity design often ignores the impact of the inlet and outlet positions on gas flow and distribution, resulting in uneven gas concentration in the air cavity, affecting sensor performance and stability. The present invention provides a basis for selecting the best inlet and outlet structure by performing simulation analysis on different inlet and outlet structures, so as to achieve rapid and uniform distribution of gas concentration in the air cavity of the gas sensor, thereby improving the performance and stability of the sensor.

[0080] The beneficial effects of the present invention include: (1) Improving the performance of gas sensors: By selecting the best inlet and outlet structure, the gas flow direction and speed in the gas cavity can be optimized, thereby accelerating the time it takes for the gas concentration to reach a uniform distribution. This helps to improve the sensitivity and response speed of the sensor, thereby improving the performance of the sensor.

[0081] (2) Improve sensor stability: The optimized inlet and outlet structures can effectively control the gas flow in the gas cavity and reduce uneven gas distribution, thereby improving the stability and repeatability of the sensor. This helps reduce the error of the sensor under different working conditions and improves its long-term stability.

[0082] (3) Providing theoretical reference values ​​for experiments: By simulating the gas cavity models with different inlet and outlet structures, the time required for the gas concentration to reach uniform distribution under different structures can be obtained. This provides a theoretical reference value for the gas intake time in gas sensor-related experiments, which helps to design a reasonable experimental plan and optimize the experimental process.

[0083] (4) Promote the development of technology: Optimized gas cavity design can improve the performance and stability of gas sensors and promote the development of gas sensing technology. This will help develop more advanced and reliable gas sensors to meet the growing application needs and promote continuous progress in this technology field.

[0084] It should be understood that the size of the serial numbers of the steps in the above embodiments does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0085] Figure 7 is a schematic block diagram of a device for determining a gas cavity of a gas sensor according to another exemplary embodiment of the present application, such as Figure 7 As shown, the device 7 includes a simulation module 701 and a determination module 702 .

[0086] A simulation module 701 is used to simulate the gas concentration distribution of the target gas entering the candidate gas cavity model based on the candidate gas cavity model, and obtain the time taken for the gas concentration of the target gas to reach a uniform distribution state; The determination module 702 is used to determine the target air cavity model with the shortest time consumption from different candidate air cavity models, and different candidate air cavity models are provided with different inlet and outlet structures; the target air cavity model is used to determine the gas sensor air cavity.

[0087] In some embodiments, the simulation module is used to: perform transient calculation of the gas concentration of the target gas entering the candidate air cavity model based on a preconfigured physical field interface, preconfigured boundary conditions and initial conditions to obtain a transient calculation result of the gas concentration, wherein the preconfigured physical field interface is used to simulate the flow and heat transfer process of the target gas in the candidate air cavity model; based on the transient calculation result, determine the time it takes for the gas concentration of the target gas to reach a uniform distribution state in the candidate air cavity model.

[0088] In some embodiments, the inlet and outlet structures of the candidate air cavity model include: the inlet and outlet are arranged in parallel on the same side of the air cavity body, the inlet and outlet are arranged on both sides of the air cavity body and form a right angle, and the inlet and outlet are arranged on both sides of the air cavity body and form a right angle.

[0089] In some embodiments, the physics interfaces include: a Non-Isothermal Flow interface, a Turbulent Reflected Flow interface, and a Transport of Diluted Species interface.

[0090] In some embodiments, the simulation module is used to: call the non-isothermal flow interface, the turbulent reaction flow interface and the dilute species transfer interface to perform multi-physics field coupling, and obtain the momentum equation, energy equation and transfer equation of the target gas respectively as equations to be solved in the transient solver; refer to the boundary conditions and initial conditions, execute the transient solver, and obtain the transient calculation results.

[0091] In some embodiments, the candidate air cavity model is a three-dimensional finite element model, the finite elements of the preset calculation area in the finite element model are obtained based on hexahedral structured grid division, and the finite elements of the preset non-calculation area in the finite element model are obtained based on tetrahedral structured grid division.

[0092] In some embodiments, the boundary conditions include: the position of the air cavity inlet, the position of the air cavity outlet, the flow rate of the target gas at the air cavity inlet, the pressure at the air cavity outlet, and the ambient temperature.

[0093] In summary, the present application proposes a device for determining the gas cavity of a gas sensor, taking into account the influence of different inlet and outlet structures on the gas flow rate and flow direction, and analyzing the relationship between the change in the position of the inlet and outlet of the gas cavity and the gas concentration distribution in the gas cavity through model simulation. The device constructs an air cavity simulation model with different inlet and outlet structures, and determines the time required for the target gas to reach a uniform concentration distribution state in the air cavity model with different inlet and outlet structures through simulation, so as to screen out an inlet and outlet structure with the shortest time consumption. The uniform distribution of gas is used as a limiting condition to provide a guarantee for the stability of the gas sensor, and the time consumption to achieve uniform distribution is optimized to provide a guarantee for the response speed of the gas sensor. The present application combines model simulation with the optimization of the inlet and outlet structure of the gas cavity, and determines the air cavity that can accelerate the uniform distribution of gas at a relatively low cost, conveniently and efficiently, thereby improving the response speed and stability of the gas sensor.

[0094] In order to implement the above embodiment, the present application embodiment also proposes an electronic device 800, such as Figure 8 As shown, the electronic device 800 may specifically include: a memory 801, a processor 802, and a computer program stored in the memory 801 and executable on the processor 802. When the processor 802 executes the program, the steps of the method for determining the gas cavity of the gas sensor as shown in the above embodiment are implemented.

[0095] In one embodiment, the present application further proposes a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the method for determining the gas cavity of a gas sensor as described in any of the above embodiments.

[0096] Those of ordinary skill in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be implemented by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to memory, storage, database or other media used in the embodiments provided in this application may include non-volatile and / or volatile memory. Non-volatile memory may include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM) or flash memory. Volatile memory may include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in many forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchlink) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM), etc.

[0097] Those skilled in the art can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example. In actual applications, the above-mentioned functions can be distributed and completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above.

[0098] The embodiments described above are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A method for determining a gas cavity of a gas sensor, characterized in that: The method comprises: Based on the candidate air cavity model, a gas concentration distribution simulation is performed on the target gas entering the candidate air cavity model to obtain the time taken for the gas concentration of the target gas to reach a uniform distribution state; Determining the target air cavity model with the shortest time consumption from different candidate air cavity models, wherein different inlet and outlet structures are arranged on different candidate air cavity models; The target air cavity model is used to determine the air cavity of the gas sensor.

2. The method according to claim 1, characterized in that The method of performing gas concentration distribution simulation on the target gas entering the candidate gas cavity model based on the candidate gas cavity model to obtain the time taken for the gas concentration of the target gas to reach a uniform distribution state includes: Based on a preconfigured physical field interface, preconfigured boundary conditions and initial conditions, a transient calculation is performed on the gas concentration of the target gas entering the candidate air cavity model to obtain a transient calculation result of the gas concentration, wherein the preconfigured physical field interface is used to simulate the flow and heat transfer process of the target gas in the candidate air cavity model; Based on the transient calculation result, the time taken for the gas concentration of the target gas to reach a uniform distribution state in the candidate air cavity model is determined.

3. The method according to claim 1, characterized in that The inlet and outlet structures of the candidate air cavity model include: the inlet and outlet are arranged in parallel on the same side of the air cavity body, the inlet and outlet are arranged on both sides of the air cavity body and form a straight angle, and the inlet and outlet are arranged on both sides of the air cavity body and form a right angle.

4. The method according to claim 2, characterized in that The physical field interfaces include: a non-isothermal flow interface, a turbulent reflected flow interface, and a dilute species transport interface.

5. The method according to claim 2, characterized in that The method of performing transient calculation on the gas concentration of the target gas entering the candidate gas cavity model based on the preconfigured physical field interface, the preconfigured boundary conditions and the initial conditions to obtain the transient calculation result of the gas concentration includes: Calling the non-isothermal flow interface, the turbulent reactive flow interface, and the transport of diluted species interface to perform multi-physics field coupling, respectively obtaining the momentum equation, energy equation, and transfer equation of the target gas as equations to be solved in the transient solver; The transient solver is executed with reference to the boundary conditions and the initial conditions to obtain the transient calculation results.

6. The method according to any one of claims 1 to 5, characterized in that: The candidate air cavity model is a three-dimensional finite element model, in which the finite elements of a preset calculation area in the finite element model are obtained based on hexahedral structured grid division, and the finite elements of a preset non-calculation area in the finite element model are obtained based on tetrahedral structured grid division.

7. The method according to claim 2, characterized in that The boundary conditions include: the position of the air cavity inlet, the position of the air cavity outlet, the flow rate of the target gas at the air cavity inlet, the pressure at the air cavity outlet, and the ambient temperature.

8. A device for determining a gas cavity of a gas sensor, characterized in that: include: A simulation module, for performing gas concentration distribution simulation on a target gas entering the candidate gas cavity model based on the candidate gas cavity model, and obtaining a time consumption for the gas concentration of the target gas to reach a uniform distribution state; A determination module, which determines the target air cavity model with the shortest time consumption from different candidate air cavity models, wherein different inlet and outlet structures are arranged on different candidate air cavity models; The target air cavity model is used to determine the air cavity of the gas sensor.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the computer program, the steps of the method for determining the gas cavity of the gas sensor according to any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the steps of the method for determining the gas cavity of a gas sensor as described in any one of claims 1 to 7 are implemented.

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