Methods, devices, and related equipment for determining the minimum safe operating angle of industrial axial compressors

Abstract

This invention relates to the field of turbomachinery technology, specifically providing a method, apparatus, and related equipment for determining the minimum safe operating angle of an industrial axial compressor. The method includes: performing steady-state CFD calculations on multiple stationary blade safe operating angles of the industrial axial compressor using a single-channel method; performing structural dynamic modal analysis on the overall model of the first-stage moving blade and tenon to obtain the first four natural frequencies and mode shapes of the blade vibration; performing steady-state and unsteady hybrid simulations based on multiple stationary blade safe operating angles to determine the modes and pitch diameters most likely to be excited by asynchronous vibration; and for each stationary blade safe operating angle, performing bidirectional fluid-structure interaction simulations based on the steady-state CFD flow field results of the entire machine and the modes and pitch diameters most likely to be excited by asynchronous vibration. If the coupled simulation results indicate that no non-integer-order vibration aeroelasticity occurs, the current stationary blade safe operating angle is determined as the minimum safe operating angle, thereby improving the calculation accuracy of the minimum safe operating angle.

Description

Technical Field

[0001] This application relates to the field of turbine machinery technology, and in particular to a method, apparatus and related equipment for determining the minimum safe operating angle of an industrial axial compressor. Background Technology

[0002] Currently, adjustable-blade industrial axial compressors are characterized by high efficiency, applicability to large and medium flow rates, and a wide range of operating conditions. In addition to traditional applications such as blast furnace blasting, catalytic cracking, extra-large air separation, biopharmaceuticals, extra-large gas sources, and wind tunnels, they can be expanded to the petroleum, chemical, and energy storage industries, bringing considerable economic and social benefits.

[0003] The stationary vane angle of an adjustable-vane industrial axial compressor is usually strictly prohibited from being less than the minimum safe operating angle in the design and operation specifications. If the compressor operates with a stationary vane angle less than the minimum safe operating angle, the first stage of the compressor is very likely to enter a gaseous instability state. At this stationary vane angle, regardless of the operating condition of the axial compressor outlet pressure, the first stage moving vane will fail and break prematurely, which will seriously affect the continuous operation and production of the process industry and cause great economic losses. Currently, the minimum safe operating angle of the stationary blades in adjustable-blade industrial axial compressors is typically determined using two methods: 1) existing empirical specifications; 2) specialized blade tip timing tests. The minimum safe operating angle determined by existing empirical specifications lacks precision, easily leading to premature blade failure and breakage due to an excessively small value, or a narrow effective operating range due to an excessively large value. Specialized blade tip timing tests involve placing blade tip timing sensors on the rigid surface of the axial compressor blades to monitor the blade vibration amplitude and dynamic stress level at different stationary blade angles. When a sudden increase in blade vibration and dynamic stress occurs, that stationary blade angle is considered the minimum safe operating angle. While this method accurately determines the minimum safe operating angle of the axial compressor, it is a specialized test requiring highly skilled personnel, involves a lengthy preparation period, and incurs extremely high costs. Therefore, industrial axial compressor manufacturers rarely conduct this type of test. Summary of the Invention

[0004] To address the aforementioned issues, this application provides a method, apparatus, and related equipment for determining the minimum safe operating angle of an industrial axial compressor. Based on a two-way fluid-structure interaction method, it analyzes whether non-integer-order vibration aeroelastic phenomena such as frequency locking and phase locking will occur in the first-stage moving blades under different stationary blade angles, thereby significantly improving the calculation accuracy of the minimum safe operating angle of the axial compressor.

[0005] To achieve the objectives of this application, the following technical solution is provided:

[0006] In a first aspect, this application provides a method for determining the minimum safe operating angle of an industrial axial compressor, including:

[0007] Determine the safe operating angles of multiple stator vanes corresponding to the industrial axial compressor;

[0008] A geometric model based on the industrial axial compressor is established, and the geometric model is meshed to obtain the target geometric model corresponding to the industrial axial compressor. After setting the flow field boundary conditions, a single-channel steady CFD calculation of the whole machine is performed based on the target geometric model under the safe operating angle of the multiple stator blades to obtain the steady CFD flow field results of the whole machine.

[0009] Structural dynamics modal analysis was performed on the first-stage moving blade and tenon integral model in the target geometric model to obtain the first four natural frequencies and mode shapes of the blade vibration.

[0010] Based on the multiple stationary blade safe operating angles, a steady-state + unsteady-state hybrid simulation was performed to determine the modes and nodal diameters most likely to be excited by asynchronous vibration.

[0011] For each of the aforementioned stator blade safe operating angles, a two-way fluid-structure interaction simulation is performed based on the steady CFD flow field results of the entire machine and the mode and pitch diameter most likely to be excited by asynchronous vibration, to obtain the coupled simulation results. The coupled simulation results are used to analyze whether non-integer order vibration aeroelasticity will occur. Wherein, if the coupled simulation results indicate that the non-integer order vibration aeroelasticity has not occurred, the current stator blade safe operating angle is determined as the minimum safe operating angle.

[0012] In one possible implementation, determining the multiple safe operating angles of the stator vanes corresponding to the industrial axial compressor includes: estimating multiple values ​​of the safe operating angles of the stator vanes of the industrial axial compressor based on empirical values; and setting the flow field boundary conditions under a selected operating condition, wherein the selected operating condition is a deep blockage condition.

[0013] In one possible implementation, the single-channel steady-state CFD calculation of the whole machine adopts the SA turbulence model, and the version of the SA turbulence model is SA-PGω-QCR2020.

[0014] In one possible implementation, to ensure computational accuracy and cycle time, the structural dynamics modal analysis employs structured hexahedral elements, and contact constraints are set between the tenon and the root groove of the target geometric model.

[0015] In one possible implementation, the step of performing a steady-unsteady hybrid simulation based on the multiple stationary blade safe operating angles to determine the modes and nodal diameters most likely to be excited by asynchronous vibration includes: analyzing the unsteady flow characteristics and spatiotemporal modal characteristics of the tip region of the first-stage moving blade based on the unsteady simulation domain; wherein the unsteady simulation domain is the full-channel computational domain of the first-stage moving blade and the directly adjacent blade row; performing a single-channel steady-state simulation for each blade row within the steady simulation domain; wherein the steady simulation domain is the computational domain of the blade rows other than the first-stage moving blade and the directly adjacent blade row.

[0016] In one possible implementation, if the coupled simulation results characterize the occurrence of the non-integer order aeroelastic vibration phenomenon, the stator angle under the current operating condition is determined to be the unsafe stator angle.

[0017] In one possible implementation, when the unsteady flow excitation frequency is locked to the natural frequency or the superposition of the natural frequency and the rotational frequency, the vibration stress in the coupled simulation results is characterized as being stably maintained at a high level, and the coupled simulation results are characterized as the occurrence of the non-integer order vibration aeroelastic phenomenon.

[0018] Secondly, this application provides a device for determining the minimum safe operating angle of an industrial axial compressor with adjustable stator vanes, used to implement the above-mentioned method for determining the minimum safe operating angle of an industrial axial compressor, including:

[0019] The determining unit is used to determine the safe operating angles of multiple stator vanes corresponding to the industrial axial compressor;

[0020] The whole machine single-channel steady CFD calculation unit is used to establish a geometric model based on the industrial axial compressor, and to perform meshing on the geometric model to obtain the target geometric model corresponding to the industrial axial compressor. After setting the flow field boundary conditions, the whole machine single-channel steady CFD calculation is performed on the target geometric model under the multiple stationary blade safe operating angles to obtain the whole machine steady CFD flow field results.

[0021] The modal analysis unit is used to perform structural dynamic modal analysis on the first-stage moving blade and tenon integral model in the target geometric model to obtain the first four natural frequencies and mode shapes of the blade vibration.

[0022] The hybrid simulation unit is used to perform steady-state and unsteady-state hybrid simulations based on the multiple stator blade safe operating angles to determine the modes and nodal diameters most likely to be excited by asynchronous vibrations.

[0023] A two-way fluid-structure interaction (FSI) simulation unit is used to perform two-way FSI simulations for each of the aforementioned stator blade safe operating angles, based on the steady CFD flow field results of the whole machine and the modes and nodal diameters most likely to be excited by asynchronous vibrations, to obtain the coupling simulation results. The coupling simulation results are used to analyze whether non-integer order vibration aeroelasticity will occur. Wherein, if the coupling simulation results indicate that the non-integer order vibration aeroelasticity has not occurred, the current stator blade safe operating angle is determined to be the minimum safe operating angle.

[0024] Thirdly, this application provides a device for determining the minimum safe operating angle of an adjustable-blade industrial axial compressor, including a memory and a processor. The memory stores a computer program, and the processor executes the computer program to implement the steps of the above method.

[0025] Fourthly, this application provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the above-described method.

[0026] The method, apparatus, and related equipment for determining the minimum safe operating angle of an industrial axial compressor disclosed in this application analyze whether non-integer-order vibration aeroelastic phenomena such as frequency locking and phase locking will occur in the first-stage moving blades under different stationary blade angles based on a two-way fluid-structure interaction model. After obtaining the dynamic stress and aeroelastic response level of the first-stage moving blades, the minimum safe operating angle of the axial compressor is determined by analyzing the flow field characteristics and dynamic stress level. This significantly improves the calculation accuracy of the minimum safe operating angle of the axial compressor, enabling industrial axial compressors with modern advanced blade profiles to have stronger adaptability. Attached Figure Description

[0027] The accompanying drawings are provided to further understand this application and form part of the specification. They are used together with the embodiments of this application to explain this application and do not constitute a limitation thereof.

[0028] Figure 1 A schematic diagram of the effective operating area of ​​the adjustable stationary vane industrial axial flow compressor provided in the embodiments of this application;

[0029] Figure 2 A schematic diagram of an optional process for determining the minimum safe operating angle of an industrial axial compressor provided in this application embodiment;

[0030] Figure 3 A schematic flowchart of an optional method for determining the minimum safe operating angle of an industrial axial compressor provided in this application embodiment;

[0031] Figure 4 The relative Mach number cloud diagrams of the flow field at three typical blade heights at a certain stationary blade angle are provided in the embodiments of this application.

[0032] Figure 5 This is a schematic diagram of the entropy cloud distribution of the flow cross section provided in an embodiment of this application;

[0033] Figure 6 A schematic diagram of the separation vortex morphology at the tip of the suction surface of the first-stage moving blade under different stationary blade angles, as provided in the embodiments of this application;

[0034] Figure 7 This is a schematic diagram of the first four vibration modes of the first-stage blade provided in an embodiment of this application;

[0035] Figure 8 A schematic diagram of the axial velocity distribution at a certain moment in three cross sections of the blade tip during unsteady simulation provided in this application embodiment;

[0036] Figure 9 A schematic diagram illustrating the historical trends of dynamic stress and vibration amplitude of five different blades of the first-stage moving blade provided in this embodiment of the application;

[0037] Figure 10 A schematic diagram of the structure of the device for determining the minimum safe operating angle of an industrial axial compressor provided in this application embodiment;

[0038] Figure 11 A schematic diagram of the structure of the device for determining the minimum safe operating angle of an industrial axial compressor provided in this application embodiment. Detailed Implementation

[0039] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0040] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature; in the description of this application, unless otherwise stated, "multiple" means two or more.

[0041] The stator vane angle of an adjustable-vane industrial axial compressor has a permissible design operating range. Exceeding this range can easily lead to an unsafe condition for the compressor. (Refer to...) Figure 1As shown, when the stator vane angle of an axial compressor reaches its maximum permissible angle during operation, the compressor will enter an ultrasonic state. This may cause excessive flow resistance in the blade stack, affecting the compressor's efficiency. It may also lead to increased separation of airflow on the blade surface, causing blockage-like problems and preventing the compressor from operating normally. At this point, the flow rate is at its maximum flow limit, and further increasing the stator vane angle will not achieve a larger flow rate. If the stator vane angle of the axial compressor is less than the minimum permissible angle (i.e., the minimum safe operating angle of the stator vane), the first stage of the compressor is very likely to enter a gaseous instability state. At this stator vane angle, regardless of the operating conditions of the axial compressor outlet pressure, the first stage moving blades will prematurely fail and break, seriously affecting continuous production in the process industry and causing significant economic losses. Currently, the minimum safe operating angle of the stationary blades in adjustable-blade industrial axial compressors is typically determined using two methods: 1) existing empirical specifications; 2) specialized blade tip timing tests. The minimum safe operating angle determined by existing empirical specifications lacks precision, easily leading to premature blade failure and breakage due to an excessively small value, or a narrow effective operating range due to an excessively large value. Specialized blade tip timing tests involve placing blade tip timing sensors on the rigid surface of the axial compressor blades to monitor the blade vibration amplitude and dynamic stress level at different stationary blade angles. When a sudden increase in blade vibration and dynamic stress occurs, that stationary blade angle is considered the minimum safe operating angle. While this method accurately determines the minimum safe operating angle of the axial compressor, it is a specialized test requiring highly skilled personnel, involves a lengthy preparation period, and incurs extremely high costs. Therefore, industrial axial compressor manufacturers rarely conduct this type of test.

[0042] To address the aforementioned technical problems, the present invention proposes the following technical solutions and corresponding embodiments.

[0043] Example 1

[0044] The following is combined with Figures 1 to 9 The illustrated embodiments describe the technical solution of the present invention:

[0045] Figure 2 A flowchart illustrating a method for determining the minimum safe operating angle of an industrial axial compressor according to an embodiment of this application is shown. Figure 2 As shown, an embodiment of this application provides a method for determining the minimum safe operating angle of an industrial axial compressor, comprising the following steps S101 to S105:

[0046] Step S101: Determine the safe operating angles of multiple stator vanes corresponding to the industrial axial compressor;

[0047] In this embodiment, the multiple safe operating angles of the stator vanes corresponding to the industrial axial compressor are several possible safe operating angles inferred from existing empirical specifications. It should be noted that the industrial axial compressor in this application is a stator-adjustable industrial axial compressor.

[0048] Step S102: Establish a geometric model based on the industrial axial compressor, and perform meshing on the geometric model to obtain the target geometric model corresponding to the industrial axial compressor. After setting the flow field boundary conditions, perform single-channel steady CFD calculation of the whole machine based on the target geometric model under the safe operating angle of the multiple stator blades to obtain the steady CFD flow field results of the whole machine.

[0049] In this embodiment, inlet and outlet boundary conditions are set for a selected operating condition, such as total inlet pressure, total inlet temperature, and outlet pressure. For example, the selected operating condition is a deep blockage condition with low exhaust pressure. Steady-state CFD calculations are performed for this selected condition, where the outlet pressure is set to the exhaust pressure under the simulated deep blockage condition with the outlet regulating valve fully open. This exhaust pressure is typically below 150 kPa. Here, the total inlet pressure is set to 101.325 kPa, the total inlet temperature to 288.15 K, and the given static outlet pressure to 150 kPa. The CFD (Computational Fluid Dynamics) method uses a computer to directly solve the Navier-Stokes equations for momentum conservation in incompressible fluids numerically. The main reason for choosing the CFD method in this application is that, through establishing a mathematical model and iterative calculations, the CFD method can obtain an accurate solution to the flow field and can flexibly simulate various complex fluid flow problems (such as turbulence).

[0050] In this embodiment, a solid wall model and a rotation-stationary interface model are set up. The rotation-stationary interface model is a model set at the interface between the rotating part (such as a moving blade) and the stationary part (such as a stationary blade). Typically, the model simulating the interaction at this interface can be a hybrid interface model or a sliding interface model. As a feasible implementation, sliding walls and wall functions are used to handle the wall boundaries, periodic boundary conditions are used for the circumferential geometric boundaries, and a mixed surface method is used to transmit information between different rows.

[0051] In this embodiment, when performing steady-state CFD calculations on the target geometric model based on the multiple stator blade safe operating angles, the SA turbulence model is selected to ensure simulation accuracy and stability; exemplarily, the selected SA turbulence model version is an improved version of the classic SA turbulence model, SA-PGω-QCR2020. As an implementation reference,

[0052] Step S103: Perform structural dynamic modal analysis on the first-stage moving blade and tenon integral model in the target geometric model to obtain the first four natural frequencies and mode shapes of the blade vibration.

[0053] In this embodiment, the finite element software ANSYS is used for structural dynamic modal analysis. To ensure calculation accuracy and periodicity, the calculation model adopts structured hexahedral elements, and the material is X3CrNiMo13-4. The elastic modulus, Poisson's ratio, density and other mechanical parameters of the material are set. The first four natural frequencies and mode shapes of the first-stage moving blade and tenon integral model are calculated by finite element analysis. Here, a cyclic symmetric model is adopted, and contact constraints are set between the tenon and the blade root groove. Stress stiffening and rotational softening effects are considered during the analysis.

[0054] Step S104: Based on the multiple stator blade safe operating angles determined in step S101, perform a steady-state + unsteady-state hybrid simulation to determine the modes and nodal diameters most likely to be excited by asynchronous vibration.

[0055] In this embodiment, to save computational costs and time, the unsteady + steady hybrid simulation method employs a nonsteady simulation domain that only includes the full-channel computational domain of the first-stage moving blade and its directly adjacent blade rows. Subsequent blade rows are simulated using a single-channel steady simulation. In other words, the unsteady simulation domain is the full-channel computational domain of the first-stage moving blade and its directly adjacent blade rows, while other blade rows are simulated using a single-channel steady simulation. Here, during the unsteady simulation, the evolution of the unsteady flow characteristics and spatiotemporal modal characteristics (such as pulsating pressure, modal force frequency, amplitude, and pitch diameter) in the tip region of the first-stage moving blade is analyzed to obtain the unsteady flow excitation frequency and pitch diameter. The natural frequency determined in step S103 is compared with the unsteady flow excitation frequency to determine whether the unsteady flow might excite the corresponding mode of the moving blade, leading to asynchronous vibration. This determination process identifies the mode and pitch diameter most likely to induce asynchronous vibration. In this embodiment, the High-order AeroDynamic External and Internal Flow Solver (HADES) simulation software is used to calculate and analyze the unsteady and steady simulation domains under the predicted safe operating angles of multiple stator blades. Here, HADES is used to perform multiphase flow, fluid-structure interaction, combustion, noise and vibration analysis, etc., to achieve high-precision simulation and analysis of aerodynamic external and internal flows.

[0056] In this embodiment of the application, when using single-channel steady-state simulation for blade rows other than the first-stage moving blade and the directly adjacent blade row, the turbulence model SA-PGω-QCR2020 determined in the implementation content of step S102 is used.

[0057] Step S105: For each of the stationary blade safe operating angles, a two-way fluid-structure interaction simulation is performed based on the steady CFD flow field results of the whole machine and the mode and pitch diameter most likely to be excited by asynchronous vibration, to obtain the coupling simulation results, so as to analyze whether non-integer order vibration aeroelasticity will occur; wherein, if the coupling simulation results indicate that the non-integer order vibration aeroelasticity has not occurred, then the current stationary blade safe operating angle is determined to be the minimum safe operating angle.

[0058] In this embodiment of the application, when the coupling simulation result indicates the occurrence of the non-integer order vibration aeroelastic phenomenon, the stator angle under the current operating condition is determined to be an unsafe stator angle; that is, if the frequency-locking and phase-locking phenomenon occurs in the calculation result of step S105, that is, the airflow excitation frequency is locked to the blade's natural frequency or the superposition of the natural frequency and the rotation frequency, entering a limit cycle vibration state with a large amplitude, and the vibration stress is stably maintained at a high level, then it can be determined that the first-stage moving blade has a non-integer order vibration phenomenon, and the stator angle under this operating condition is an unsafe stator angle. Long-term operation at this angle will lead to premature blade failure.

[0059] In this embodiment, the CFD simulation and structural dynamics modal analysis are based on a coupled interface for mutual iteration. That is, within each time step, the calculation results of the flow field and the structural field are transferred to each other until the convergence criterion is reached. Then, the vibration amplitude and dynamic stress level of the first-stage blade under the convergence result are obtained, and the aeroelastic stability of the blade is evaluated by the flow field separation cluster scale characteristics and dynamic stress level, and finally the minimum safe operating angle is determined.

[0060] As a feasible implementation method, this application uses HADES to perform bidirectional fluid-structure interaction simulations on models under several possible minimum safe operating angles.

[0061] The method for determining the minimum safe operating angle of an industrial axial compressor provided in this application analyzes whether non-integer-order vibration aeroelastic phenomena such as frequency locking and phase locking will occur in the first-stage moving blades under different stationary blade angles based on the two-way fluid-structure interaction method. By analyzing the vibration amplitude and dynamic stress level, the minimum safe operating angle of the axial compressor is determined, thereby significantly improving the calculation accuracy of the minimum safe operating angle of the axial compressor and enabling industrial axial compressors with modern advanced blade profiles to have stronger adaptability.

[0062] Example 2

[0063] Based on the above embodiments, this embodiment also provides a method for determining the minimum safe operating angle of an industrial axial flow compressor. Figure 3 This is a schematic diagram of one possible process for determining the minimum safe operating angle of an industrial axial compressor provided in this embodiment, as shown below. Figure 3As shown, the method of this embodiment includes the following steps S301 to S304, which include the following contents:

[0064] Step S301: Perform a single-channel steady-state CFD calculation on the estimated minimum safe operating angles.

[0065] Specifically, given the inlet and outlet boundary conditions for the selected operating conditions, a solid wall model and a static-to-static interface model are set, and different turbulence models are selected to obtain the steady CFD flow field of the whole machine.

[0066] Specifically, in single-channel steady-state CFD analysis, the inlet boundary conditions are given as total pressure and total temperature, while the outlet boundary conditions are preferentially selected as the exhaust pressure under simulated deep-blocking conditions with the outlet regulating valve fully open (typically below 150 kPa). Simultaneously, the accuracy of the steady-state performance prediction results is evaluated based on experimental data to determine the most suitable turbulence model for unsteady simulation of this type of axial compressor. The most suitable turbulence model for this type of axial compressor is SA-PGω-QCR2020, an improved version of the classic SA turbulence model.

[0067] In this embodiment, a deep blockage condition with low exhaust pressure is selected, and steady-state CFD calculations are performed for the selected condition. The inlet boundary conditions are a total pressure of 101.325 kPa and a total temperature of 288.15 K, and the outlet given static pressure is 150 kPa. The wall boundary is handled using a sliding wall and a wall function, the circumferential geometric boundary uses a periodic boundary condition, and the information is transmitted between different rows using a mixing surface method. Figure 4 This is a relative Mach number cloud map of the flow field at three typical blade heights under a certain stationary blade angle. Figure 5 This is a schematic diagram of the entropy cloud distribution across the flow path. The diagram shows a large-scale low-velocity and separation cluster occupying the entire flow path at the tip of the first-stage moving blade. Figure 6 This is a schematic diagram of the separation vortex morphology at the tip of the suction surface of the first-stage moving blade under different stationary blade angles when aeroelastic instability exists.

[0068] Step S302: Perform structural dynamic modal analysis on the overall model of the first-stage moving blade and tenon. After selecting the finite element calculation mesh element, elastic modulus, Poisson's ratio, density and calculation setting parameters, obtain the first four natural frequencies and mode shapes of the blade vibration.

[0069] In this embodiment of the application, in order to ensure the accuracy and cycle of the calculation, the calculation model adopts a structured hexahedral element, the material is X3CrNiMo13-4, a cyclic symmetric model is adopted, and contact constraints are set between the tenon and the blade root groove. Stress stiffening and rotational softening effects are considered in the analysis process. Figure 7 This is a schematic diagram of the first four vibration modes of the first-stage moving blade in an embodiment of this application.

[0070] Step S303: Based on the determined turbulence model, use the simulation software HADES to perform unsteady + steady hybrid simulation on the several minimum safe operating angles to determine the modes and pitch of asynchronous vibration.

[0071] The unsteady + steady hybrid simulation method involves using a full-channel computational domain in the unsteady simulation domain that includes only the first-stage moving blade and directly adjacent blade rows, while subsequent blade rows are simulated using a single-channel steady simulation. Specifically, it analyzes the evolution of unsteady flow characteristics and spatiotemporal modal properties (pulsating pressure, modal force frequency, amplitude, and nodal diameter, etc.) in the tip region of the first-stage moving blade, and combines the modal analysis results with the unsteady flow excitation frequency and nodal diameter to determine the modes and nodal diameters most likely to be excited by asynchronous vibration. Figure 8 This is a schematic diagram of the axial velocity distribution of three sections at a certain moment in an unsteady simulation of the blade tip. In this diagram, the low-speed airflow blocking the blade tip channel exhibits aeroelastic characteristics of asynchronous vibration.

[0072] Step S304: Perform bidirectional fluid-structure interaction simulation on the several possible minimum safe operating angles, obtain the vibration amplitude and dynamic stress level of the first-stage moving blade under the convergence result, evaluate the aeroelastic stability of the blade through the flow field separation cluster scale characteristics and dynamic stress level, and finally determine the minimum safe operating angle of the axial compressor.

[0073] If frequency-locking and phase-locking occur in the calculation results, meaning the airflow excitation frequency is locked to the blade's natural frequency or a superposition of the natural frequency and rotational frequency, entering a limit cycle vibration state with a large amplitude, and the vibration stress remains stably at a high level, then it can be determined that the first-stage moving blade is experiencing non-integer order vibration. The stationary blade angle under this condition is an unsafe stationary blade angle; long-term operation at this angle will lead to premature blade failure. If frequency-locking and phase-locking do not occur in the calculation results of step 304, and the amplitude and dynamic stress level of the first-stage moving blade are low, then the stationary blade angle under this condition is a safe operating stationary blade angle. Figure 9 This is a schematic diagram illustrating the historical trends of dynamic stress and vibration amplitude for five different blades of the first-stage moving blade. (Reference) Figure 9 As shown, when the blade vibration amplitude gradually decreases and the absolute value remains at a low level, the stationary blade angle under this working condition can be determined to be a safe stationary blade angle.

[0074] This application embodiment also provides a device 1000 for determining the minimum safe operating angle of an industrial axial flow compressor, for reference. Figure 10 As shown, it may include:

[0075] Determining unit 1001 is used to determine multiple stationary vane safe operating angles corresponding to the industrial axial compressor;

[0076] The whole machine single-channel steady CFD calculation unit 1002 is used to establish a geometric model based on the industrial axial compressor, and to perform meshing on the geometric model to obtain the target geometric model corresponding to the industrial axial compressor. After setting the flow field boundary conditions, the whole machine single-channel steady CFD calculation is performed on the target geometric model under the multiple stator blade safe operating angles to obtain the whole machine steady CFD flow field results.

[0077] Modal analysis unit 1003 is used to perform structural dynamic modal analysis on the first-stage moving blade and tenon integral model in the target geometric model to obtain the first four natural frequencies and mode shapes of the blade vibration.

[0078] The hybrid simulation unit 1004 is used to perform steady-state and unsteady-state hybrid simulation based on the multiple stator blade safe operating angles to determine the modes and nodal diameters most likely to be excited by asynchronous vibration.

[0079] The two-way fluid-structure interaction simulation unit 1005 is used to perform two-way fluid-structure interaction simulation for each of the stator blades' safe operating angles, based on the steady CFD flow field results of the whole machine and the mode and pitch diameter most likely to be excited by asynchronous vibration, to obtain the coupled simulation results, so as to analyze whether non-integer order vibration aeroelasticity will occur through the coupled simulation results; wherein, if the coupled simulation results indicate that the non-integer order vibration aeroelasticity has not occurred, the current stator blade safe operating angle is determined to be the minimum safe operating angle.

[0080] The minimum safe operating angle determination device for adjustable-vane industrial axial compressors provided in this application embodiment can be applied to equipment for determining the minimum safe operating angle of adjustable-vane industrial axial compressors, such as computers. Optionally, Figure 11 The hardware structure block diagram of the device 1100 for determining the minimum safe operating angle of an industrial axial compressor is shown. (Refer to...) Figure 11 The hardware structure of the device for determining the minimum safe operating angle of an adjustable-blade industrial axial compressor may include a processor 111, a memory, a network interface 113, and a database 11213 connected via a system bus 114. The processor 111 provides computing and control capabilities; the memory includes a non-volatile storage medium 1121 and internal memory 1122, wherein the non-volatile storage medium 1121 stores an operating system 11211, computer programs 11212, and the database 11213, and the internal memory 1122 provides an environment for the operation of the operating system 11211 and computer programs 11212 in the non-volatile storage medium; the database 11213 provides data such as the operating programs of each system node; the network interface 113 is used for communication with external terminals via a network connection; when the computer program is executed by the processor 111, it implements the method for determining the minimum safe operating angle of an industrial axial compressor as described in any of the above embodiments.

[0081] This application also provides a computer-readable storage medium storing a computer program. When executed by a processor, the computer programmer implements the method for determining the minimum safe operating angle of an industrial axial compressor according to any embodiment of this application. Specifically, a system or device equipped with a storage medium can be provided, on which software program code implementing the functions of any of the above embodiments is stored, and the computer (or CPU or MPU) of the system or device can read and execute the program code stored in the storage medium.

[0082] In particular, according to embodiments of the present invention, the processes described above with reference to the flowcharts can be implemented as computer software programs. For example, embodiments of the present invention include a computer program product comprising a computer program carried on a computer-readable storage medium, the computer program containing program code for performing the methods shown in the flowcharts. In such embodiments, the computer program can be downloaded and installed from a network via a communication component, and / or installed from a removable medium. When the computer program is executed by a central processing unit (CPU), it performs the functions defined in the system of this application.

[0083] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of the present invention. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions indicated in the blocks may occur in a different order than those indicated in the drawings. For example, two consecutively indicated blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in a block diagram or flowchart, and combinations of blocks in a block diagram or flowchart, may be implemented using a dedicated hardware-based system that performs the specified function or operation, or using a combination of dedicated hardware and computer instructions.

[0084] The units described in the embodiments of the present invention can be implemented in software or hardware, and the described units can also be located in a processor. The names of these units do not necessarily limit the specific unit itself.

[0085] It should be noted that although several modules or units of the device for performing actions have been mentioned in the detailed description above, this division is not mandatory. In fact, according to embodiments of the present invention, the features and functions of two or more modules or units described above can be embodied in one module or unit. Conversely, the features and functions of one module or unit described above can be further divided and embodied by multiple modules or units.

[0086] Through the above description of the embodiments, those skilled in the art will readily understand that the exemplary embodiments described herein can be implemented by software or by combining software with necessary hardware. Therefore, the technical solutions according to the embodiments of the present invention can be embodied in the form of a software product, which can be stored in a non-volatile storage medium (such as a CD-ROM, USB flash drive, portable hard drive, etc.) or on a network, including several instructions to cause a computing device (such as a personal computer, server, touch terminal, or network device, etc.) to execute the method according to the embodiments of the present invention.

[0087] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit it. This application is not limited to the exact structures described above and illustrated in the accompanying drawings, and it should not be considered that the specific implementation of this application is limited to these descriptions. For those skilled in the art, various changes and modifications made without departing from the concept of this application should be considered to fall within the protection scope of this application.

[0088] In the several embodiments provided in this application, it should be understood that the disclosed systems, modules, and methods can be implemented in other ways. For example, the module embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces, or indirect coupling or communication connection between modules or units, and may be electrical, mechanical, or other forms.

[0089] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit it. This application is not limited to the exact structures described above and illustrated in the accompanying drawings, and it should not be considered that the specific implementation of this application is limited to these descriptions. For those skilled in the art, various changes and modifications made without departing from the concept of this application should be considered to fall within the protection scope of this application.

Claims

1. A method for determining the minimum safe operating angle of an industrial axial flow compressor, characterized in that, include: Determine the safe operating angles of multiple stator vanes corresponding to the industrial axial compressor; A geometric model based on the industrial axial compressor is established, and the geometric model is meshed to obtain the target geometric model corresponding to the industrial axial compressor. After setting the flow field boundary conditions, a single-channel steady CFD calculation of the whole machine is performed based on the target geometric model under the safe operating angle of the multiple stator blades to obtain the steady CFD flow field results of the whole machine. Structural dynamic modal analysis was performed on the first-stage moving blade and tenon integral model in the target geometric model to obtain the first four natural frequencies and mode shapes of the blade vibration. Based on the multiple stator blade safe operating angles, a hybrid steady-state and unsteady-state simulation was performed to determine the modes and nodal diameters most likely to be excited by asynchronous vibration, including: The unsteady flow characteristics and spatiotemporal modal properties of the tip region of the first-stage moving blade are analyzed based on the unsteady simulation domain; wherein, the unsteady simulation domain is the full-channel computational domain of the first-stage moving blade and the directly adjacent blade row; A single-channel steady-state simulation is performed on each leaf row within the steady-state simulation domain; wherein, the steady-state simulation domain is the computational domain of all leaf rows except the first-stage moving blade and the directly adjacent leaf rows. For each of the aforementioned stator blade safe operating angles, a two-way fluid-structure interaction simulation is performed based on the steady CFD flow field results of the entire machine and the mode and pitch diameter most likely to be excited by asynchronous vibration, to obtain the coupled simulation results. The coupled simulation results are used to analyze whether non-integer order vibration aeroelasticity will occur. Wherein, if the coupled simulation results indicate that the non-integer order vibration aeroelasticity has not occurred, the current stator blade safe operating angle is determined as the minimum safe operating angle.

2. The method for determining the minimum safe operating angle of an industrial axial compressor according to claim 1, characterized in that, Determining the multiple safe operating angles of the stator vanes corresponding to the industrial axial flow compressor includes: estimating multiple values ​​of the safe operating angles of the stator vanes of the industrial axial flow compressor based on empirical values; The flow field boundary conditions are set under a selected operating condition, which is a deep blockage condition.

3. The method for determining the minimum safe operating angle of an industrial axial compressor according to claim 2, characterized in that, The single-channel steady-state CFD calculation of the whole machine adopts the SA turbulence model, and the version of the SA turbulence model is SA-PGω-QCR2020.

4. The method for determining the minimum safe operating angle of an industrial axial compressor according to claim 2, characterized in that, During the structural dynamics modal analysis, structured hexahedral elements are used, and contact constraints are set between the tenon and the root groove of the target geometric model.

5. The method for determining the minimum safe operating angle of an industrial axial compressor according to claim 1, characterized in that, The method further includes: When the coupling simulation results indicate that the non-integer order aeroelastic vibration phenomenon has occurred, the stator angle under the current operating condition is determined to be the unsafe stator angle.

6. The method for determining the minimum safe operating angle of an industrial axial compressor according to claim 5, characterized in that, When the unsteady flow excitation frequency is locked to the natural frequency or the superposition of the natural frequency and the rotational frequency, the vibration stress in the coupled simulation results is characterized as being maintained at a high level, and the coupled simulation results are characterized as the occurrence of the non-integer order vibration aeroelastic phenomenon.

7. A device for determining the minimum safe operating angle of an industrial axial compressor with adjustable stator vanes, used to implement the method for determining the minimum safe operating angle of an industrial axial compressor as described in any one of claims 1-6, characterized in that, include: The determining unit is used to determine the safe operating angles of multiple stator vanes corresponding to the industrial axial compressor; The whole machine single-channel steady CFD calculation unit is used to establish a geometric model based on the industrial axial compressor, and to perform meshing on the geometric model to obtain the target geometric model corresponding to the industrial axial compressor. After setting the flow field boundary conditions, the whole machine single-channel steady CFD calculation is performed on the target geometric model under the multiple stationary blade safe operating angles to obtain the whole machine steady CFD flow field results. The modal analysis unit is used to perform structural dynamic modal analysis on the first-stage moving blade and tenon integral model in the target geometric model to obtain the first four natural frequencies and mode shapes of the blade vibration. The hybrid simulation unit is used to perform steady-state and unsteady-state hybrid simulations based on the multiple stator blade safe operating angles to determine the modes and nodal diameters most likely to be excited by asynchronous vibrations. A two-way fluid-structure interaction (FSI) simulation unit is used to perform two-way FSI simulations for each of the aforementioned stator blade safe operating angles, based on the steady CFD flow field results of the whole machine and the modes and nodal diameters most likely to be excited by asynchronous vibrations, to obtain the coupling simulation results. The coupling simulation results are used to analyze whether non-integer order vibration aeroelasticity will occur. Wherein, if the coupling simulation results indicate that the non-integer order vibration aeroelasticity has not occurred, the current stator blade safe operating angle is determined to be the minimum safe operating angle.

8. A device for determining the minimum safe operating angle of an adjustable-blade industrial axial compressor, comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the method according to any one of claims 1 to 6.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 6.

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