Method and system for evaluating operation safety and reliability of axial flow fan

Abstract

The invention relates to an axial flow fan operation safety and reliability evaluation method and system. The method comprises the steps that an axial flow fan geometric model is established, a fluid space is extracted, a rotor area is established, and inlet and outlet pipelines are lengthened to the given length; dividing grids, importing the grids into numerical simulation software, giving a flow or back pressure condition, and carrying out iterative calculation until convergence; flow, pressure and torque parameters are collected; data are sorted, static pressure-flow and static pressure efficiency-flow curves are drawn, and a stable operation interval is analyzed; and a working environment flow field model is established, and the operation stability is analyzed and judged in combination with a fan performance curve. According to the method, the efficient and stable operation interval is rapidly and visually positioned through digital simulation, potential safety hazards such as stall and surge are effectively avoided, the operation safety and equipment reliability of the fan are remarkably improved, meanwhile, energy consumption is reduced, the service life is prolonged, and a reliable basis is provided for fan type selection matching and operation optimization.

Description

Technical Field

[0001] This invention relates to the field of wind turbine technology, and in particular to a method and system for assessing the operational safety and reliability of axial flow fans. Background Technology

[0002] Axial flow fans are typical fluid machines that rely on electrical power to increase gas pressure and flow velocity. Due to their simple structure, large ventilation volume, and wide adjustment range, they are widely used in industries such as energy and power, water conservancy and irrigation, mining and metallurgy, shipbuilding, and air conditioning and refrigeration. The internal flow of an axial flow fan is a viscous, unsteady three-dimensional motion, and during operation, instability phenomena such as flow separation, rotational stall, surge, and blade flutter frequently occur.

[0003] The performance curve of axial flow fans is usually expressed as pressure rise-flow rate (ΔP-Q). The hump curve is a special phenomenon characterized by one or more local pressure peaks in the low flow rate region, forming a shape resembling a "hump." This phenomenon is closely related to fan stall and surge. When a fan stalls, the airflow and pressure decrease significantly, causing drastic changes in the flow within the duct. The significantly increased vibration of the stalled fan can easily lead to surge, damaging the equipment and endangering the safe operation of the unit, directly affecting operational stability. Summary of the Invention

[0004] In view of this, it is necessary to provide a method and system for assessing the operational safety and reliability of axial flow fans in order to solve the above-mentioned problems in the prior art.

[0005] To address the aforementioned problems, in a first aspect, embodiments of the present invention provide a method for assessing the operational safety and reliability of an axial flow fan, comprising:

[0006] Establish the geometric model of the axial flow fan, extract the fluid space from the fan inlet to the outlet, and create the fan rotor region in the fluid space; extend the inlet and outlet pipes to the given length;

[0007] The fluid domain of the fan and the inlet and outlet pipeline areas are meshed, the mesh model is imported into the numerical simulation software, and numerical iterative calculations are performed in the numerical simulation software with given flow or back pressure conditions. The inlet and outlet flow and pressure parameters of the pipeline are monitored until the calculation reaches convergence.

[0008] Collect flow parameters, pressure parameters, and torque parameters at the inlet and outlet of the pipeline; wherein, the flow parameters include the volumetric flow rate at the pipeline outlet, the pressure parameters include the static pressure and total pressure at the inlet and outlet of the pipeline, and the torque parameters include the torque along the axis of the fan rotor.

[0009] The collected data were processed, and the static pressure-flow rate curve and static pressure efficiency-flow rate curve of the fan were plotted to analyze the stable operating range of the fan.

[0010] Establish a flow field geometric model of the fan's working environment and divide it into meshes. Import the fan's static pressure-flow rate curve and the mesh into the software for analysis, monitor the fan's air volume, and determine whether the fan is operating stably.

[0011] Preferably, extending the inlet and outlet pipes to a given length includes:

[0012] The inlet pipe length is greater than the pipe characteristic length, and the outlet pipe length is greater than twice the pipe outlet characteristic length; the formula for calculating the pipe characteristic length L is:

[0013]

[0014] In the formula, S is the cross-sectional area of ​​the pipe, and C is the perimeter of the pipe.

[0015] Preferably, when dividing the fan fluid domain and inlet / outlet pipe area into grids, the rotor area is the fluid area that includes the rotor part, and the shortest distance between the outer boundary of the fluid area and the rotor part is no more than 50mm.

[0016] Preferably, the stable operating range of the fan is the range to the right of the inflection point of the static pressure efficiency-flow rate curve.

[0017] Preferably, determining whether the fan is operating smoothly includes:

[0018] Determine whether the fan flow rate under actual operating conditions is within the fan's stable operating range.

[0019] Preferably, the formula for calculating the static pressure of the fan is:

[0020] P ts =P s_out -P t_in

[0021] In the formula, P ts For the static pressure of the fan, P s_out P is the average static pressure at the outlet section. t_in The total pressure at the inlet section.

[0022] Preferably, the formula for calculating the static pressure efficiency is:

[0023]

[0024] In the formula, η ts Q is the static pressure efficiency of the fan. v For volumetric flow rate, T imp ω represents torque, and ω represents rotational speed.

[0025] Secondly, embodiments of the present invention provide an axial flow fan operation safety and reliability assessment system, comprising:

[0026] The fan model building module creates a geometric model of the axial flow fan, extracts the fluid space from the fan inlet to the outlet, creates the fan rotor region in the fluid space, and extends the inlet and outlet pipes to a given length.

[0027] The mesh simulation calculation module is used to divide the fluid domain and inlet and outlet pipeline areas of the fan into meshes, import the mesh model into the numerical simulation software, give the flow rate or back pressure conditions in the numerical simulation software, perform numerical iterative calculations, monitor the inlet and outlet flow and pressure parameters of the pipeline, and stop when the calculation reaches convergence.

[0028] The parameter acquisition module is used to acquire flow parameters, pressure parameters, and torque parameters at the inlet and outlet of the pipeline; wherein, the flow parameters include the volumetric flow rate at the pipeline outlet, the pressure parameters include the static pressure and total pressure at the inlet and outlet of the pipeline, and the torque parameters include the torque along the axis of the fan rotor.

[0029] The performance analysis module is used to process the collected data, plot the static pressure-flow rate curve and static pressure efficiency-flow rate curve of the fan, and analyze the stable operating range of the fan.

[0030] The operation judgment module is used to establish the flow field geometric model of the fan's working environment and divide it into meshes. The static pressure-flow curve of the fan and the mesh are imported into the software for analysis, monitoring the fan's air volume and judging whether the fan is running smoothly.

[0031] Thirdly, the present invention also provides an electronic device, including a memory and a processor, wherein,

[0032] The memory is used to store programs;

[0033] The processor, coupled to the memory, is used to execute the program stored in the memory to implement the steps in the axial flow fan operation safety and reliability assessment method as described in the first aspect embodiment of the present invention.

[0034] Fourthly, the present invention also provides a computer-readable storage medium for storing a computer-readable program or instruction, which, when executed by a processor, enables the implementation of the steps in the axial flow fan operation safety and reliability assessment method as described in the first aspect embodiment of the present invention.

[0035] The method and system for assessing the operational safety and reliability of axial flow fans provided by this invention have the following advantages compared with existing technologies:

[0036] This invention establishes a simulation model of an axial flow fan and plots static pressure-flow rate curves and static pressure efficiency-flow rate curves to accurately analyze the fan's stable operating range, avoiding problems such as stall and surge caused by operating in unstable ranges. By jointly simulating the fan performance curves with the actual working environment flow field, the operational safety of the fan under field conditions is directly evaluated, improving the practicality and accuracy of the evaluation results. Attached Figure Description

[0037] Figure 1 Flowchart of the axial flow fan operation safety and reliability assessment method provided by the present invention;

[0038] Figure 2 The structural diagram of the axial flow fan provided by the present invention;

[0039] Figure 3 The geometric model of the axial flow fan and pipeline provided by this invention;

[0040] Figure 4 This is a schematic diagram of the axial flow fan and pipe mesh division provided by the present invention;

[0041] Figure 5 The static pressure-flow rate curve and static pressure efficiency-flow rate curve of the axial flow fan provided by this invention;

[0042] Figure 6 The present invention provides a method for monitoring the air delivery volume of an axial flow fan during actual operation.

[0043] Figure 7 This is a structural block diagram of the electronic device provided by the present invention.

[0044] In the diagram, 1-casing, 2-hub, 3-impeller, 4-rear guide vane, 5-motor. Detailed Implementation

[0045] Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which form part of this application and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not intended to limit the scope of the present invention.

[0046] Current technologies for assessing the operational safety and reliability of axial flow fans primarily rely on traditional performance testing and empirical judgment. However, these methods have the following problems. On the one hand, traditional performance testing often ignores the complex viscous and unsteady three-dimensional flow characteristics inside the fan, making it difficult to accurately capture instability phenomena such as flow separation, rotational stall, and surge, resulting in inaccurate judgments of the fan's stable operating range. On the other hand, empirical judgment lacks scientific basis and cannot be dynamically evaluated in conjunction with the actual working environment of the fan, easily causing the fan to operate in an unstable range, increasing the risk of equipment failure, affecting the safe operation of the unit, and failing to effectively extend the fan's service life and reduce energy consumption.

[0047] In view of this, the present invention aims to provide a method for assessing the operational safety and reliability of axial flow fans. This method determines the stable operating range of the axial flow fan and evaluates it based on the actual operating environment, preventing the fan from operating in an unstable range, thus improving the operational safety and reliability of the axial flow fan, while also extending the fan's service life and reducing energy consumption. Several embodiments will be described and illustrated below.

[0048] Figure 1 The flowchart of the axial flow fan operation safety and reliability assessment method provided by the present invention is shown below. Figure 1 The method for assessing the operational safety and reliability of axial flow fans provided by this invention includes at least the following steps:

[0049] Step S1: Establish the geometric model of the axial flow fan, extract the fluid space from the fan inlet to the outlet, and create the fan rotor region in the fluid space; extend the inlet and outlet pipes to the given length.

[0050] Specifically, firstly, the geometric model of the axial flow fan needs to be based on the actual structure of the fan. The axial flow fan used in this embodiment of the invention includes a casing, hub, impeller, rear guide vanes, and motor, such as... Figure 2 As shown, the model covers core components such as the casing, hub, impeller, rear guide vanes, and motor, ensuring that it accurately reflects the physical form of the fan. Based on this, the fluid space from the fan inlet to the outlet is extracted. This space encompasses the entire path of airflow within the fan and is the core computational region for subsequent flow field simulation. Its boundaries must precisely correspond to the inlet and outlet positions of the fan to ensure the integrity of the airflow range.

[0051] Next, a separate fan rotor region needs to be created within the fluid space. This region specifically encloses rotating components such as the impeller, and the shortest distance between its outer boundary and the rotor section does not exceed 50mm. This is to accurately capture the disturbance effect of the rotor rotation on the surrounding fluid, ensuring that subsequent simulations can accurately simulate the interaction between the rotating components and the fluid.

[0052] Finally, extend the inlet and outlet pipes of the fan to a given length. The cross-section of the pipe can be circular, elliptical, or any polygonal structure. The length of the inlet pipe must be greater than one times the characteristic length of the inlet pipe, and the length of the outlet pipe must be greater than twice the characteristic length of the outlet pipe. The formula for calculating the characteristic length L of the pipe is:

[0053]

[0054] In the formula, S is the cross-sectional area of ​​the pipe, and C is the perimeter of the pipe.

[0055] For cylindrical pipes, the characteristic length is directly taken as the inlet diameter D, such as... Figure 3As shown. Other pipe shapes are calculated using cross-sectional area and perimeter. The purpose of extending the pipe is to reduce the interference of the inlet and outlet boundaries on the internal flow field of the fan, allowing the airflow to form a stable flow state before entering the fan and to fully develop after leaving the fan, thereby improving the accuracy of subsequent numerical simulations and providing a reliable geometric basis for the entire evaluation method.

[0056] This invention provides a high-fidelity computational foundation for numerical simulation by accurately establishing the geometric model of the fluid domain of an axial flow fan and standardizing the extension of the duct. This step ensures that the fluid space completely covers the flow path, the rotor region setting accurately captures rotational effects, and the duct extension effectively eliminates boundary interference.

[0057] Step S2: Mesh the fluid domain of the fan and the inlet and outlet pipe areas, import the mesh model into the numerical simulation software, give the flow rate or back pressure conditions in the numerical simulation software, perform numerical iterative calculation, monitor the inlet and outlet flow rate and pressure parameters of the pipes, and stop when the calculation reaches convergence.

[0058] Specifically, to mesh the fan fluid domain and inlet / outlet pipe areas, it is necessary to spatially discretize these areas. This process involves decomposing the continuous fluid space into numerous discrete small units. Figure 4 For the axial flow fan and duct mesh division in this invention, refer to Figure 4 This invention employs a polyhedral mesh generation method. By reasonably setting the mesh size and density, it ensures that the discretized elements can accurately reflect the details of the flow field. In particular, the mesh quality must be guaranteed in complex flow regions such as around the rotor, providing a reliable discretized model for subsequent numerical calculations.

[0059] Next, the pre-defined fan assembly mesh model is imported into numerical simulation software. This software is a commonly used fluid simulation program, such as FLUENT, STAR-CCM+, CFX, COMSOL, or OPENFOAM. After importing, parameters need to be set within the software, including air properties and fan speed. Air properties include density, specific heat, thermal conductivity, and viscosity. These parameters need to be set according to actual operating conditions to match real fluid characteristics. The fan speed is determined based on the fan design parameters or actual operating speed to ensure consistency between simulation and reality.

[0060] Then, flow rate or back pressure conditions are given in the numerical software to simulate different operating conditions. The flow rate condition sets the volume of fluid passing through the pipe per unit time, while the back pressure condition sets the pressure value at the outlet. Numerical iterative calculations are then initiated, and the software gradually approximates the true state of the flow field by repeatedly solving the fluid dynamics control equations.

[0061] During the calculation process, the flow rate and pressure parameters at the inlet and outlet of the pipeline need to be continuously monitored. When these parameters no longer change significantly with the increase of the number of iterations, it indicates that the calculation has reached the convergence state. At this time, the calculation is stopped to obtain stable flow field data under this working condition, which provides a basis for subsequent parameter acquisition and analysis.

[0062] Step S3: Collect the flow rate parameters, pressure parameters, and torque parameters at the inlet and outlet of the pipeline; wherein, the flow rate parameters include the volumetric flow rate at the pipeline outlet, the pressure parameters include the static pressure and total pressure at the inlet and outlet of the pipeline, and the torque parameters include the torque along the axis of the fan rotor.

[0063] Specifically, step S3 is the core step in obtaining the key data required for the evaluation, mainly focusing on parameter acquisition and multi-condition data accumulation. First, flow parameters, pressure parameters, and torque parameters at the pipe inlet and outlet are collected. Flow parameters focus on the volumetric flow rate at the pipe outlet, reflecting the amount of fluid passing through the fan per unit time. Pressure parameters cover the static pressure and total pressure at the pipe inlet and outlet. Static pressure reflects the potential energy state of the fluid, while total pressure comprehensively reflects both potential and kinetic energy; combining these two parameters allows for a comprehensive assessment of the fan's pressure change characteristics. Torque parameters specifically refer to the torque along the fan rotor axis, used to measure the resistance torque experienced by the rotor during rotation, and are an important basis for calculating the fan's power and efficiency.

[0064] To ensure data comprehensiveness, steps S1 to S3 need to be repeated to collect the above parameters under various operating conditions. By changing the flow rate or back pressure conditions, the performance of the wind turbine under different operating states is simulated, accumulating multiple sets of corresponding flow rate, pressure, and torque data. These data cover the possible operating range of the wind turbine, providing sufficient and representative samples for subsequent performance curve plotting and analysis of stable operating ranges, ensuring the accuracy and reliability of the evaluation results.

[0065] Step S4: Organize the collected data, plot the static pressure-flow rate curve and static pressure efficiency-flow rate curve of the fan, and analyze the stable operating range of the fan.

[0066] Specifically, the collected flow, pressure, and torque parameters are systematically processed, outliers are removed, and the data format is standardized. Based on the processed data, two types of core curves are plotted using numerical analysis tools: the static pressure-flow rate curve and the static pressure efficiency-flow rate curve. Static pressure is calculated using the average static pressure at the outlet section and the total pressure at the inlet section, while static pressure efficiency is derived from a formula combining volumetric flow rate, torque, and rotational speed. The formula for calculating the fan static pressure is:

[0067] P ts =P s_out -P t_in

[0068] In the formula, P ts For the static pressure of the fan, Ps_out P is the average static pressure at the outlet section. t_in The total pressure at the inlet section.

[0069] The formula for calculating static pressure efficiency is:

[0070]

[0071] In the formula, η ts Q is the static pressure efficiency of the fan. v For volumetric flow rate, T imp ω represents torque, and ω represents rotational speed.

[0072] Subsequently, the curve characteristics were analyzed, and the interval to the right of the inflection point of the static pressure efficiency-flow rate curve was determined as the stable operating interval. Figure 5 The static pressure-flow rate curve and static pressure efficiency-flow rate curve of the axial flow fan provided by this invention are as follows: Figure 5 As shown, the air volume is determined to be greater than 17.65m³. 3 / s represents the stable operating range of the wind turbine.

[0073] This invention, by plotting characteristic curves and defining stable operating ranges, transforms discrete parameter data into intuitive performance characteristics, thereby achieving a quantitative definition of the wind turbine's operating state. It precisely delineates the stable range through the static pressure efficiency inflection point, providing a clear standard for subsequent assessments based on actual environmental conditions. This effectively avoids the limitations of relying on experience-based judgments and improves the scientific rigor and accuracy of wind turbine operational safety assessments.

[0074] Step S5: Establish the flow field geometric model of the fan's working environment and divide it into meshes. Import the fan's static pressure-flow rate curve and mesh into the software for analysis, monitor the fan's air volume, and determine whether the fan is operating stably.

[0075] Specifically, in step S5, the fan performance is combined with the actual working environment to complete the safety and reliability assessment of the axial flow fan. First, a comprehensive analysis of the fan's working environment is required, including factors such as the installation space structure, the distribution of surrounding obstacles, and the initial state of the airflow. Based on these actual conditions, a corresponding environmental flow field geometric model is established to ensure that the model accurately reflects the airflow movement space on site. Next, this environmental flow field geometric model is meshed, and through spatial discretization, the continuous environmental flow field is decomposed into multiple computational units, providing a computable basic model for subsequent numerical analysis.

[0076] Then, the previously plotted static pressure-flow rate curves of the fan and the defined environmental mesh are imported into the numerical simulation software for secondary numerical analysis. The software simulates the actual operating state of the fan in that environment based on the environmental flow field characteristics and the fan performance curves, with a focus on monitoring the fan's airflow data. Figure 6 To monitor the air delivery volume of the axial flow fan during actual operation, the present invention refers to... Figure 6 Monitoring revealed that the actual air delivery volume of the fan was approximately 19m³. 3 / s.

[0077] Finally, the fan operating status is determined based on the monitored actual air volume: the actual air volume is compared with the stable operating range determined in step S4 (e.g., 17.65m). 3 By comparing the actual air volume (with the inflection point as / s), if the actual air volume is within the stable range to the right of the inflection point, it is determined that the fan is operating smoothly and the design matches the working environment; otherwise, it is considered that there is a risk in operation.

[0078] The method of this invention can simulate the axial flow fan and the on-site environment on a computer. By analyzing the parameters after simulation, the stable operating range of the axial flow fan can be identified, and the stability of the fan under on-site environmental conditions can be assessed. By obtaining the fan's operating status through computer simulation, the entire process is conducted on a computer, which is fast and intuitive, saving time and effort in monitoring the fan's operating status, improving the safety and reliability of axial flow fan operation, extending the fan's service life, and reducing energy consumption.

[0079] This invention establishes a simulation model of an axial flow fan and plots static pressure-flow rate curves and static pressure efficiency-flow rate curves to accurately analyze the fan's stable operating range, avoiding problems such as stall and surge caused by operating in unstable ranges. By jointly simulating the fan performance curves with the actual working environment flow field, the operational safety of the fan under field conditions is directly evaluated, improving the practicality and accuracy of the evaluation results.

[0080] In a preferred embodiment of the present invention, an axial flow fan operation safety and reliability assessment system is provided, comprising:

[0081] The fan model building module creates a geometric model of the axial flow fan, extracts the fluid space from the fan inlet to the outlet, creates the fan rotor region in the fluid space, and extends the inlet and outlet pipes to a given length.

[0082] The mesh simulation calculation module is used to divide the fluid domain and inlet and outlet pipeline areas of the fan into meshes, import the mesh model into the numerical simulation software, give the flow rate or back pressure conditions in the numerical simulation software, perform numerical iterative calculations, monitor the inlet and outlet flow and pressure parameters of the pipeline, and stop when the calculation reaches convergence.

[0083] The parameter acquisition module is used to acquire flow parameters, pressure parameters, and torque parameters at the inlet and outlet of the pipeline; wherein, the flow parameters include the volumetric flow rate at the pipeline outlet, the pressure parameters include the static pressure and total pressure at the inlet and outlet of the pipeline, and the torque parameters include the torque along the axis of the fan rotor.

[0084] The performance analysis module is used to process the collected data, plot the static pressure-flow rate curve and static pressure efficiency-flow rate curve of the fan, and analyze the stable operating range of the fan.

[0085] The operation judgment module is used to establish the flow field geometric model of the fan's working environment and divide it into meshes. The static pressure-flow curve of the fan and the mesh are imported into the software for analysis, monitoring the fan's air volume and judging whether the fan is running smoothly.

[0086] The axial flow fan operation safety and reliability assessment system provided by the present invention is used to execute the axial flow fan operation safety and reliability assessment method provided in the foregoing embodiments. The axial flow fan operation safety and reliability assessment method has been described in detail in the foregoing embodiments, and will not be repeated here.

[0087] Figure 7 A structural block diagram of the electronic device provided by the present invention, such as Figure 7 As shown, the present invention also provides an electronic device 700, which can be a mobile terminal, desktop computer, laptop, handheld computer, server, or other computing device. The electronic device 700 includes a processor 701 and a memory 702, wherein the memory 702 stores an axial flow fan operation safety and reliability assessment program 703.

[0088] In some embodiments, memory 702 may be an internal storage unit of a computer device, such as a hard disk or memory. In other embodiments, memory 702 may be an external storage device of a computer device, such as a plug-in hard disk, smart media card (SMC), secure digital card (SD), flash card, etc. Further, memory 702 may include both internal and external storage units of the computer device. Memory 702 is used to store application software and various types of data installed on the computer device, such as program code for installing the computer device. Memory 702 can also be used to temporarily store data that has been output or will be output. In one embodiment, when the axial flow fan operation safety and reliability assessment program 703 is executed by processor 701, the following steps are implemented:

[0089] Establish the geometric model of the axial flow fan, extract the fluid space from the fan inlet to the outlet, and create the fan rotor region in the fluid space; extend the inlet and outlet pipes to the given length;

[0090] The fluid domain of the fan and the inlet and outlet pipeline areas are meshed, the mesh model is imported into the numerical simulation software, and numerical iterative calculations are performed in the numerical simulation software with given flow or back pressure conditions. The inlet and outlet flow and pressure parameters of the pipeline are monitored until the calculation reaches convergence.

[0091] Collect flow parameters, pressure parameters, and torque parameters at the inlet and outlet of the pipeline; wherein, the flow parameters include the volumetric flow rate at the pipeline outlet, the pressure parameters include the static pressure and total pressure at the inlet and outlet of the pipeline, and the torque parameters include the torque along the axis of the fan rotor.

[0092] The collected data were processed, and the static pressure-flow rate curve and static pressure efficiency-flow rate curve of the fan were plotted to analyze the stable operating range of the fan.

[0093] Establish a flow field geometric model of the fan's working environment and divide it into meshes. Import the fan's static pressure-flow rate curve and the mesh into the software for analysis, monitor the fan's air volume, and determine whether the fan is operating stably.

[0094] In some embodiments, processor 701 may be a central processing unit (CPU), microprocessor or other data processing chip, used to run program code stored in memory 702 or process data, such as executing an axial flow fan operation safety and reliability assessment program.

[0095] This embodiment also provides a computer-readable storage medium storing an axial flow fan operation safety and reliability assessment program. When the axial flow fan operation safety and reliability assessment program is executed by a processor, it performs the following steps:

[0096] Establish the geometric model of the axial flow fan, extract the fluid space from the fan inlet to the outlet, and create the fan rotor region in the fluid space; extend the inlet and outlet pipes to the given length;

[0097] The fluid domain of the fan and the inlet and outlet pipeline areas are meshed, the mesh model is imported into the numerical simulation software, and numerical iterative calculations are performed in the numerical simulation software with given flow or back pressure conditions. The inlet and outlet flow and pressure parameters of the pipeline are monitored until the calculation reaches convergence.

[0098] Collect flow parameters, pressure parameters, and torque parameters at the inlet and outlet of the pipeline; wherein, the flow parameters include the volumetric flow rate at the pipeline outlet, the pressure parameters include the static pressure and total pressure at the inlet and outlet of the pipeline, and the torque parameters include the torque along the axis of the fan rotor.

[0099] The collected data were processed, and the static pressure-flow rate curve and static pressure efficiency-flow rate curve of the fan were plotted to analyze the stable operating range of the fan.

[0100] Establish a flow field geometric model of the fan's working environment and divide it into meshes. Import the fan's static pressure-flow rate curve and the mesh into the software for analysis, monitor the fan's air volume, and determine whether the fan is operating stably.

[0101] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the appended claims.

[0102] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for assessing the operational safety and reliability of an axial flow fan, characterized in that, include: Establish a geometric model of the axial flow fan, extract the fluid space from the fan inlet to the outlet, and create the fan rotor region in the fluid space; Extend the inlet and outlet pipelines to a given length; The fluid domain of the fan and the inlet and outlet pipeline areas are meshed, the mesh model is imported into the numerical simulation software, and numerical iterative calculations are performed in the numerical simulation software with given flow or back pressure conditions. The inlet and outlet flow and pressure parameters of the pipeline are monitored until the calculation reaches convergence. Collect flow parameters, pressure parameters, and torque parameters at the inlet and outlet of the pipeline; wherein, the flow parameters include the volumetric flow rate at the pipeline outlet, the pressure parameters include the static pressure and total pressure at the inlet and outlet of the pipeline, and the torque parameters include the torque along the axis of the fan rotor. The collected data were processed, and the static pressure-flow rate curve and static pressure efficiency-flow rate curve of the fan were plotted to analyze the stable operating range of the fan. Establish a flow field geometric model of the fan's working environment and divide it into meshes. Import the fan's static pressure-flow rate curve and the mesh into the software for analysis, monitor the fan's air volume, and determine whether the fan is operating stably.

2. The method for assessing the operational safety and reliability of an axial flow fan according to claim 1, characterized in that, The extension of the inlet and outlet pipelines to a given length includes: The inlet pipe length is greater than the pipe characteristic length, and the outlet pipe length is greater than twice the pipe outlet characteristic length; the formula for calculating the pipe characteristic length L is: In the formula, S is the cross-sectional area of ​​the pipe, and C is the perimeter of the pipe.

3. The method for assessing the operational safety and reliability of an axial flow fan according to claim 1, characterized in that, When dividing the fluid domain and inlet / outlet pipe area of ​​the fan into grids, the rotor area is the fluid area that includes the rotor part, and the shortest distance between the outer boundary of the fluid area and the rotor part is no more than 50mm.

4. The method for assessing the operational safety and reliability of an axial flow fan according to claim 1, characterized in that, The stable operating range of the fan is the range to the right of the inflection point of the static pressure efficiency-flow rate curve.

5. The method for assessing the operational safety and reliability of an axial flow fan according to claim 1, characterized in that, The determination of whether the fan is operating smoothly includes: Determine whether the fan flow rate under actual operating conditions is within the fan's stable operating range.

6. The method for assessing the operational safety and reliability of an axial flow fan according to claim 1, characterized in that, The formula for calculating the static pressure of the fan is: P ts =P s_out -P t_in In the formula, P ts For the static pressure of the fan, P s_out P is the average static pressure at the outlet section. t_in The total pressure at the inlet section.

7. The method for assessing the operational safety and reliability of an axial flow fan according to claim 1, characterized in that, The formula for calculating the static pressure efficiency is: In the formula, η ts Q is the static pressure efficiency of the fan. v For volumetric flow rate, T imp ω represents torque, and ω represents rotational speed.

8. A system for assessing the operational safety and reliability of an axial flow fan, characterized in that, include: The fan model creation module establishes the geometric model of the axial flow fan, extracts the fluid space from the fan inlet to the outlet, and creates the fan rotor region in the fluid space; Extend the inlet and outlet pipelines to a given length; The mesh simulation calculation module is used to divide the fluid domain and inlet and outlet pipeline areas of the fan into meshes, import the mesh model into the numerical simulation software, give the flow rate or back pressure conditions in the numerical simulation software, perform numerical iterative calculations, monitor the inlet and outlet flow and pressure parameters of the pipeline, and stop when the calculation reaches convergence. The parameter acquisition module is used to acquire flow parameters, pressure parameters, and torque parameters at the inlet and outlet of the pipeline; wherein, the flow parameters include the volumetric flow rate at the pipeline outlet, the pressure parameters include the static pressure and total pressure at the inlet and outlet of the pipeline, and the torque parameters include the torque along the axis of the fan rotor. The performance analysis module is used to process the collected data, plot the static pressure-flow rate curve and static pressure efficiency-flow rate curve of the fan, and analyze the stable operating range of the fan. The operation judgment module is used to establish the flow field geometric model of the fan's working environment and divide it into meshes. The static pressure-flow curve of the fan and the mesh are imported into the software for analysis, monitoring the fan's air volume and judging whether the fan is running smoothly.

9. An electronic device, Its features are, Including memory and processor, among which, The memory is used to store programs; The processor, coupled to the memory, is used to execute the program stored in the memory to implement the steps in the axial flow fan operation safety and reliability assessment method according to any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that, Used to store computer-readable programs or instructions, which, when executed by a processor, can implement the steps in the axial flow fan operation safety and reliability assessment method according to any one of claims 1 to 7.

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