Method and device for determining minimum safe operation angle of industrial axial flow compressor and related equipment

Abstract

The invention relates to the technical field of turbomachinery, and particularly provides a method and device for determining the minimum safe operation angle of an industrial axial flow compressor and related equipment, and the method comprises the steps: carrying out complete machine single-channel steady CFD calculation on a plurality of static blade safe operation angles corresponding to the industrial axial flow compressor; carrying out structural dynamics modal analysis on the first-stage moving blade and tenon integral model to obtain first four-order inherent frequencies and vibration modes of blade vibration; performing steady and unsteady hybrid simulation based on the plurality of stationary blade safe operation angles, and determining a mode and a pitch diameter which are most likely to be excited to generate asynchronous vibration; and for each stationary blade safe operation angle, bidirectional fluid-solid coupling simulation is carried out based on a whole machine steady CFD flow field result and a modal and pitch diameter which are most likely to excite asynchronous vibration, and under the condition that a coupling simulation result represents that no non-integral-order vibration aeroelastic phenomenon occurs, the current stationary blade safe operation angle is determined to be the minimum safe operation angle, and the current stationary blade safe operation angle is determined to be the minimum static blade safe operation angle. Therefore, the calculation precision of the minimum safe operation angle is improved.

Description

Technical Field

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

[0002] At present, industrial axial compressors with adjustable stator blades have the characteristics of high efficiency, suitability for large and medium flow rates and a wide range of operating adjustment conditions. In addition to traditional uses 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, and have considerable economic and social benefits.

[0003] The design and operation specifications of industrial axial compressors with adjustable stator blades usually strictly prohibit the stator blade angle from being operated at a level less than the minimum safe operating angle. If the stator blade angle of the compressor is operated at a level less than the minimum safe operating angle, the first stage of the compressor is very likely to enter an aeroelastic unstable state. At this stator blade angle, no matter what the outlet pressure of the axial compressor is in, the first stage moving blades will fail and break prematurely, which will have a serious impact on the continuous operation of the process industry and cause huge economic losses. At present, the minimum safe operating angle of the stator blades of industrial axial compressors with adjustable stator blades is usually determined by the following two methods: 1) existing empirical standard values; 2) special blade tip timing test; among them, the minimum safe operating angle determined by the existing empirical standard values ​​lacks precision, and it is easy for the blades to fail and break prematurely due to too small a value, and too large a value leads to a narrow effective working range; and the special blade tip timing test is actually to arrange blade tip timing sensors on the bearing steel surface of the axial compressor blade to monitor the blade vibration amplitude and dynamic stress level at different stator blade angles. Among them, when the blade vibration and dynamic stress levels suddenly increase, the stator blade angle is determined to be the minimum safe operating angle. Here, the minimum safe operating angle of the axial compressor can be accurately determined through the blade tip timing test, but this test subject belongs to a special test, which requires extremely high professional quality of the test personnel, and the test preparation cycle is long and the test cost is extremely high. Therefore, industrial axial compressor manufacturers rarely conduct this type of test. Summary of the invention

[0004] In response to the above problems, the present application provides a method, device and related equipment for determining the minimum safe operating angle of an industrial axial compressor. Based on the bidirectional fluid-solid coupling method, it analyzes whether the first-stage moving blades will experience non-integral-order vibration aeroelastic phenomena such as frequency locking and phase locking at different stationary blade angles, thereby significantly improving the calculation accuracy of the minimum safe operating angle of the axial compressor.

[0005] To achieve the purpose of this application, this application provides the following technical solutions:

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

[0007] Determining a plurality of safe operating angles of stationary blades corresponding to the industrial axial compressor;

[0008] Establishing a geometric model based on the industrial axial compressor, meshing the geometric model, obtaining a target geometric model corresponding to the industrial axial compressor, and performing a single-channel steady-state CFD calculation of the whole machine based on the target geometric model under the safe operating angles of the multiple stator blades after setting the flow field boundary conditions, to obtain a steady-state CFD flow field result of the whole machine;

[0009] Performing structural dynamics modal analysis on the first-stage moving blade and tenon overall model in the target geometric model to obtain the first four natural frequencies and vibration modes of the blade;

[0010] Performing a steady + unsteady hybrid simulation based on the multiple stationary blade safe operation angles to determine the mode and pitch diameter that are most likely to be excited to cause asynchronous vibration;

[0011] For each of the stator blade safe operating angles, a bidirectional fluid-solid coupling simulation is performed based on the steady-state CFD flow field results of the whole machine and the modes and node diameters that are most likely to be excited to cause asynchronous vibrations, to obtain a coupling simulation result, so as to analyze whether a non-integer order vibration aeroelastic phenomenon will occur through the coupling simulation result; wherein, when the coupling simulation result indicates that the non-integer order vibration aeroelastic phenomenon does not occur, the current stator blade safe operating angle is determined to be the minimum safe operating angle.

[0012] In one possible implementation, determining a plurality of safe operating angles of stationary blades corresponding to the industrial axial compressor includes: obtaining a plurality of values ​​of the safe operating angles of the stationary blades 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 operating condition.

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

[0014] In a possible implementation, in order to ensure calculation accuracy and cycle, during the structural dynamics modal analysis, structured hexahedral units are used, and contact constraints are set between the tenon and the blade root groove of the target geometric model.

[0015] In a possible implementation, the steady + unsteady mixed simulation is performed based on the multiple stationary blade safe operating angles to determine the mode and node diameter that are most likely to be excited to cause asynchronous vibration, including: analyzing the unsteady flow characteristics and time-space modal characteristics of the tip area of ​​the first-stage moving blade based on the unsteady simulation domain; wherein the unsteady simulation domain is the full-channel calculation domain of the first-stage moving blades and the directly adjacent blade rows; performing a single-channel steady simulation on each blade row in the steady simulation domain; wherein the steady simulation domain is the calculation domain where the other blade rows except the first-stage moving blades and the directly adjacent blade rows are located.

[0016] In a possible implementation, when the coupling simulation result is characterized by the occurrence of the non-integral-order vibration aeroelastic phenomenon, it is determined that the stator blade angle under the current operating condition is an unsafe stator blade angle.

[0017] In a 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 coupling simulation result is stably maintained at a high level, and the coupling simulation result is characterized by the occurrence of the non-integral order vibration aeroelastic phenomenon.

[0018] In a second aspect, the present application provides a device for determining a minimum safe operating angle of an industrial axial flow compressor with adjustable stator blades, which is used to implement the above-mentioned method for determining a minimum safe operating angle of an industrial axial flow compressor, comprising:

[0019] A determination unit, used to determine a plurality of safe operating angles of stationary blades corresponding to the industrial axial compressor;

[0020] A whole-machine single-channel steady-state CFD calculation unit is used to establish a geometric model based on the industrial axial compressor, and to mesh the geometric model to obtain a target geometric model corresponding to the industrial axial compressor, and to perform a whole-machine single-channel steady-state CFD calculation based on the target geometric model under the multiple stationary blade safe operation angles after setting the flow field boundary conditions, to obtain a whole-machine steady-state CFD flow field result;

[0021] A modal analysis unit is used to perform structural dynamics modal analysis on the first-stage moving blade and tenon overall model in the target geometric model to obtain the first four natural frequencies and vibration modes of the blade;

[0022] A hybrid simulation unit, used for performing a steady + unsteady hybrid simulation based on the plurality of stationary blade safe operation angles, and determining a mode and a pitch diameter that are most likely to be excited to cause asynchronous vibration;

[0023] A bidirectional fluid-solid coupling simulation unit is used to perform bidirectional fluid-solid coupling simulation for each of the stator blade safe operating angles based on the steady-state CFD flow field results of the whole machine and the modes and node diameters that are most likely to be excited to cause asynchronous vibrations, to obtain coupling simulation results, so as to analyze whether non-integer order vibration aeroelastic phenomenon will occur through the coupling simulation results; wherein, when the coupling simulation results indicate that the non-integer order vibration aeroelastic phenomenon does not occur, it is determined that the current stator blade safe operating angle is the minimum safe operating angle.

[0024] In a third aspect, the present application provides a device for determining the minimum safe operating angle of an industrial axial compressor with adjustable stator blades, comprising a memory and a processor, wherein the memory stores a computer program, and the processor implements the steps of the above method when executing the computer program.

[0025] In a fourth aspect, the present application provides a computer-readable storage medium having a computer program stored thereon, wherein the computer program implements the steps of the above method when executed by a processor.

[0026] The method, device and related equipment for determining the minimum safe operating angle of an industrial axial compressor of the present application analyze whether the first-stage moving blades at different stationary blade angles will experience non-integral-order vibration aeroelastic phenomena such as frequency locking and phase locking based on a bidirectional fluid-solid coupling 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 levels, thereby significantly improving the calculation accuracy of the minimum safe operating angle of the axial compressor, so that industrial axial compressors with modern advanced blade shapes can have stronger adaptability. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The accompanying drawings are used to provide a further understanding of the present application and form a part of the specification. Together with the embodiments of the present application, they are used to explain the present application and do not constitute a limitation to the present application.

[0028] Figure 1 A schematic diagram of the effective operating area corresponding to the industrial axial compressor with adjustable stator blades provided in an embodiment of the present application;

[0029] Figure 2 An optional flow chart of a method for determining the minimum safe operating angle of an industrial axial compressor provided in an embodiment of the present application;

[0030] Figure 3 An optional flow chart of a method for determining the minimum safe operating angle of an industrial axial compressor provided in an embodiment of the present application;

[0031] Figure 4 The relative Mach number cloud diagrams of the flow field at three typical blade heights at a certain stator blade angle provided in the embodiment of the present application;

[0032] Figure 5 A schematic diagram of the distribution of the entropy cloud diagram of the flow section provided in the embodiment of the present application;

[0033] Figure 6 A schematic diagram of the separation vortex morphology when aeroelastic instability exists at the tip of the suction surface of the first-stage moving blade at different stationary blade angles provided in an embodiment of the present application;

[0034] Figure 7 A schematic diagram of the first four vibration modes of the first-stage rotor blade provided in an embodiment of the present application;

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

[0036] Fig. 9 A schematic diagram of the historical trend of dynamic stress and vibration amplitude of five different blades of the first-stage rotor blade provided in an embodiment of the present application;

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

[0038] Fig.11 A schematic diagram of the structure of a device for determining the minimum safe operating angle of an industrial axial compressor provided in an embodiment of the present application. DETAILED DESCRIPTION

[0039] In order to make the purpose, technical solutions and advantages of this application clearer, the technical solutions in this application will be clearly and completely described below in conjunction with the drawings in this application. Obviously, the described embodiments are part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without creative work 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 understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features; in the description of this application, unless otherwise specified, "plurality" means two or more.

[0041] The stator blade angle of industrial axial compressors with adjustable stator blades has an allowable design operating range. If the operating range is exceeded, the compressor is likely to be in an unsafe state. Figure 1As shown in the figure, when the stator blade angle reaches the maximum allowable angle when the axial compressor is running, the axial compressor will enter a supersonic state, which may cause the flow resistance of the airflow in the blade grid to be too large, affecting the efficiency of the compressor. It may also cause the separation of the airflow on the blade surface to intensify, causing problems similar to blockage, making the compressor unable to work normally. At this time, the flow rate is at the maximum flow limit value, and continuing to increase the stator blade angle will not be able to achieve a larger flow rate; if the stator blade angle is less than the minimum allowable angle (i.e., the minimum safe working angle of the stator blade) when the axial compressor is running, the first stage of the compressor is very likely to enter an aeroelastic unstable state. At this stator blade angle, no matter what the outlet pressure of the axial compressor is in, the first stage moving blades will fail and break prematurely, which will have a serious impact on the continuous operation and production of the process industry and cause huge economic losses. At present, the minimum safe operating angle of the stator blades of industrial axial compressors with adjustable stator blades is usually determined by the following two methods: 1) existing empirical standard values; 2) special blade tip timing test; among them, the minimum safe operating angle determined by the existing empirical standard values ​​lacks precision, and it is easy for the blades to fail and break prematurely due to too small a value, and too large a value leads to a narrow effective working range; and the special blade tip timing test is actually to arrange blade tip timing sensors on the bearing steel surface of the axial compressor blade to monitor the blade vibration amplitude and dynamic stress level at different stator blade angles. Among them, when the blade vibration and dynamic stress levels suddenly increase, the stator blade angle is determined to be the minimum safe operating angle. Here, the minimum safe operating angle of the axial compressor can be accurately determined through the blade tip timing test, but this test subject belongs to a special test, which requires extremely high professional quality of the test personnel, and the test preparation cycle is long and the test cost is extremely high. Therefore, industrial axial compressor manufacturers rarely conduct this type of test.

[0042] In order to solve the above technical problems, the present invention proposes the following technical solutions and corresponding embodiments.

[0043] Example 1

[0044] Combine the following Figures 1 to 9 The embodiments shown describe the technical solution of the present invention:

[0045] Figure 2 FIG. 2 is a flow chart showing a method for determining the minimum safe operating angle of an industrial axial compressor according to an embodiment of the present application. Figure 2 As shown, a method for determining the minimum safe operating angle of an industrial axial compressor in an embodiment of the present application includes the following steps S101 to S105:

[0046] Step S101, determining a plurality of safe operating angles of stationary blades corresponding to the industrial axial flow compressor;

[0047] In the embodiment of the present application, the multiple stator blade safe operation angles corresponding to the industrial axial flow compressor are several possible safe operation angles inferred from existing empirical specifications. It should be noted that the industrial axial flow compressor of the present application is an industrial axial flow compressor with adjustable stator blades.

[0048] Step S102: establish a geometric model based on the industrial axial compressor, and mesh the geometric model to obtain a target geometric model corresponding to the industrial axial compressor, and after setting the flow field boundary conditions, perform a single-channel steady-state CFD calculation of the whole machine based on the target geometric model under the safe operating angles of the multiple stator blades to obtain a steady-state CFD flow field result of the whole machine.

[0049] In the embodiment of the present application, the inlet and outlet boundary conditions are set for the selected working condition, such as the inlet total pressure, the inlet total temperature and the outlet pressure. For example, the selected working condition is a deep blocking working condition with low exhaust pressure, and a steady CFD calculation is performed for the selected working condition, wherein the outlet pressure is set to the exhaust pressure when the outlet regulating valve is fully opened under the deep blocking working condition simulation, and the exhaust pressure is usually lower than 150kPa. Here, the inlet total pressure is set to 101.325kPa, the inlet total temperature is 288.15K, and the outlet given static The pressure is 150kPa. Fluid Dynamics, computational fluid dynamics) method uses computational The machine directly numerically solves the NS equations for conservation of momentum of incompressible fluids; the main reason for selecting the CFD method in this application is that the CFD method can obtain accurate solutions to the flow field by establishing mathematical models and iterative calculations, and can flexibly simulate various complex fluid flow problems (such as turbulence).

[0050] In the embodiment of the present application, a solid wall model and a rotating-static interface model are set, wherein the rotating-static interface model is a model set at the interface between the rotating part (such as the moving blade) and the stationary part (such as the stationary blade). Generally, the model simulating the interaction at the interface can be a mixed interface model or a slip interface model. As a feasible implementation method, the wall boundary is processed by using a slip wall and a wall function, the circumferential geometric boundary adopts a periodic boundary condition, and the mixed surface method is used to transmit information between different rows.

[0051] In the embodiment of the present application, when performing the single-channel steady-state CFD calculation of the whole machine based on the target geometric model under the safe operating angles of the multiple stator blades, the turbulence model selects the SA turbulence model to ensure the simulation accuracy and stability; illustratively, the SA turbulence model version selected is the improved version of the classic SA turbulence model SA-PGω-QCR2020. As an implementation reference,

[0052] Step S103, performing structural dynamics modal analysis on the first-stage moving blade and tenon overall model in the target geometric model to obtain the first four-order natural frequencies and vibration modes of the blade.

[0053] In an embodiment of the present application, the finite element software ANSYS is used to perform structural dynamic modal analysis, wherein, in order to ensure the calculation accuracy and period, the calculation model adopts a structured hexahedral unit, the material is X3CrNiMo13-4, the elastic modulus, Poisson's ratio, density and other mechanical parameters of the material are set, and the first four-order natural frequencies and vibration modes of the first-stage moving blade and tenon overall model are calculated through finite element analysis; here, a cyclic symmetric model is adopted, and a contact constraint is set between the tenon and the blade root groove, and stress stiffening and rotational softening effects are considered during the analysis process.

[0054] Step S104: performing a steady + unsteady hybrid simulation based on the plurality of stationary blade safe operating angles determined in step S101 to determine the mode and pitch diameter that are most likely to be excited to cause asynchronous vibration.

[0055] In the embodiment of the present application, in order to save computational cost and computational time, the unsteady + steady hybrid simulation method is adopted, and the unsteady simulation domain only includes the full channel calculation domain of the first-stage moving blades and the directly adjacent blade rows, and the subsequent blade rows are all subjected to single-channel steady simulation, that is, the unsteady simulation domain is the full channel calculation domain of the first-stage moving blades and the directly adjacent blade rows, and the other blade rows except the first-stage moving blades and the directly adjacent blade rows are subjected to single-channel steady simulation. Here, when performing unsteady simulation, the unsteady flow characteristics and the evolution of the spatiotemporal modal characteristics (such as pulsating pressure, modal force frequency, amplitude, and nodal diameter) of the tip area of ​​the first-stage moving blades are analyzed to obtain the unsteady flow excitation frequency and nodal diameter, and the natural frequency determined in the above step S103 is compared with the unsteady flow excitation frequency to determine whether the unsteady flow may excite the corresponding mode of the moving blades and thus cause asynchronous vibration, so as to determine the mode and nodal diameter that are most likely to be excited to cause asynchronous vibration in the judgment process. In the embodiment of the present application, the simulation software high-order aerodynamics internal and external flow solver (High-order AeroDynamic External and internal flow Solver (HADES) performs computational analysis on the unsteady simulation domain and steady simulation domain under multiple assumed safe operating angles of stator blades. Here, HADES is used to perform multiphase flow, fluid-solid interaction, combustion, noise and vibration analysis, etc., to achieve high-precision simulation and analysis of aerodynamic internal and external flows.

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

[0057] Step S105: For each of the safe operating angles of the stator blade, a bidirectional fluid-solid coupling simulation is performed based on the steady-state CFD flow field results of the whole machine and the modes and node diameters that are most likely to be excited to cause asynchronous vibrations, to obtain a coupling simulation result, so as to analyze whether a non-integer order vibration aeroelastic phenomenon will occur through the coupling simulation result; wherein, if the coupling simulation result indicates that the non-integer order vibration aeroelastic phenomenon does not occur, then the current safe operating angle of the stator blade is determined to be the minimum safe operating angle.

[0058] In the embodiment of the present application, when the coupling simulation result is characterized by the occurrence of the non-integer order vibration aeroelastic phenomenon, it is determined that the stator blade angle under the current operating condition is an unsafe stator blade 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 natural frequency or the superposition of the natural frequency and the rotation frequency, and enters a limit cycle vibration state with a larger amplitude, and the vibration stress is stably maintained at a high level, it can be determined that the first-stage moving blade has a non-integer order vibration phenomenon, and the stator blade angle of this operating condition is an unsafe stator blade angle. Long-term operation at this angle will cause the blade to fail prematurely.

[0059] In an embodiment of the present application, a coupling interface is used to iterate each other based on the aforementioned CFD simulation and structural dynamics modal analysis, that is, within each time step, the calculation results of the flow field and the structural field are transmitted to each other until the convergence criterion is reached; then, the vibration amplitude and dynamic stress level of the first-stage moving 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, the present application uses HADES to perform bidirectional fluid-solid coupling simulation on the model under several possible minimum safe operating angles.

[0061] The method for determining the minimum safe operating angle of an industrial axial compressor provided in the present application analyzes whether the first-stage moving blades will experience non-integral-order vibration aeroelastic phenomena such as frequency locking and phase locking at different stationary blade angles based on a bidirectional fluid-solid coupling method, and determines the minimum safe operating angle of the axial compressor by analyzing its vibration amplitude and dynamic stress level, thereby significantly improving the calculation accuracy of the minimum safe operating angle of the axial compressor, so that industrial axial compressors with modern advanced blade shapes can have stronger adaptability.

[0062] Example 2

[0063] Based on the above embodiment, this embodiment also provides a method for determining the minimum safe operating angle of an industrial axial compressor. Figure 3 An optional flow chart of the method for determining the minimum safe operating angle of an industrial axial compressor provided in this embodiment is as follows: Figure 3As shown, the method of this embodiment includes the following steps S301 to S304 including the following contents:

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

[0065] Among them, the inlet and outlet boundary conditions are given for the selected working conditions, the solid wall model and the rotation-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 the single-channel steady CFD analysis, the inlet boundary conditions are given the total pressure and total temperature, and the outlet boundary conditions are preferentially selected under the simulated exhaust pressure (usually less than 150kPa) under the fully open outlet control valve under deep blocking conditions; at the same time, the accuracy of the steady performance prediction results is evaluated based on the test data to determine the turbulence model that is most suitable for the unsteady simulation of the current type of axial compressor. The most suitable turbulence model for this type of axial compressor is SA-PGω-QCR2020, which is an improved version of the classic SA turbulence model.

[0067] In the embodiment of the present application, a deep blocking condition with low exhaust pressure is selected, and a steady CFD calculation is performed for the selected condition. The inlet boundary conditions are a total pressure of 101.325 kPa, a total temperature of 288.15 K, and an outlet given static pressure of 150 kPa. The wall boundary is processed by a sliding wall and a wall function, and the circumferential geometric boundary adopts a periodic boundary condition. The mixing surface method is used to transmit information between different rows. Figure 4 The relative Mach number cloud diagrams of the flow field at three typical blade heights at a certain static blade angle are shown below. Figure 5 The schematic diagram of the entropy cloud distribution of the flow section shows that there is a large-scale low-speed and separation group occupying the entire channel in the tip section of the first-stage moving blade. Figure 6 Schematic diagram of the separation vortex morphology when aeroelastic instability exists at the tip of the suction surface of the first-stage moving blade at different stationary blade angles.

[0068] Step S302, perform structural dynamic modal analysis on the first-stage moving blade and tenon overall model, select finite element calculation grid units, elastic modulus, Poisson's ratio, density and calculation setting parameters to obtain the first four natural frequencies and vibration modes of the blade vibration.

[0069] In the embodiment of the present application, in order to ensure the calculation accuracy and period, the calculation model adopts structured hexahedral units, the material is X3CrNiMo13-4, a cyclic symmetry model is adopted, a contact constraint is set between the tenon and the blade root groove, and stress stiffening and rotation softening effects are considered during the analysis process. Figure 7 Schematic diagram of the first four vibration modes of the first-stage moving blades of an embodiment of the present application.

[0070] Step S303: Based on the determined turbulence model, use the simulation software HADES to perform unsteady + steady mixed simulation on the several minimum safe operation angles to determine the mode and node diameter of the asynchronous vibration.

[0071] Among them, the unsteady + steady hybrid simulation method is that the unsteady simulation domain only includes the full channel calculation domain of the first-stage moving blades and the directly adjacent blade rows, and the subsequent blade rows adopt single-channel steady simulation; specifically, the unsteady flow characteristics and the evolution of the spatiotemporal modal characteristics (pulsating pressure, modal force frequency, amplitude, and node diameter, etc.) in the tip area of ​​the first-stage moving blade are analyzed, and the modal analysis results and the unsteady flow excitation frequency and node diameter are combined to determine the mode and node diameter that are most likely to be excited to cause asynchronous vibration. Figure 8 This is a schematic diagram of the axial velocity distribution at a certain moment in the three sections of the blade tip of the unsteady simulation, in which the low-speed airflow blocks the blade tip channel with the characteristics of the aeroelastic phenomenon of asynchronous vibration.

[0072] Step S304, perform a bidirectional fluid-solid coupling 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 the frequency-locked and phase-locked phenomenon occurs in the calculation results, that is, the airflow excitation frequency is locked to the blade natural frequency or the superposition of the natural frequency and the rotation frequency, and enters a limit cycle vibration state with a large amplitude, and the vibration stress is stably maintained at a high level, it can be determined that the first-stage moving blade has a non-integral order vibration phenomenon, and the stationary blade angle of this working condition is an unsafe stationary blade angle. Long-term operation at this angle will cause the blade to fail prematurely. If the frequency-locked and phase-locked phenomenon does not occur in the calculation results of step 304, the amplitude and dynamic stress level of the first-stage moving blade are low, and the stationary blade angle of this working condition is a stationary blade angle that can be safely operated. Fig. 9 This is a schematic diagram of the historical trend of dynamic stress and vibration amplitude of five different blades of the first-stage rotor blade. Fig. 9 As shown, when the blade vibration amplitude gradually decreases and the absolute value is maintained at a low level, it can be judged that the stator blade angle of this operating condition is a safe stator blade angle.

[0074] The present application also provides a device 1000 for determining the minimum safe operating angle of an industrial axial compressor, referring to Fig.10 As shown, it may include:

[0075] A determination unit 1001 is used to determine a plurality of safe operating angles of stationary blades 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 flow compressor, and mesh the geometric model to obtain a target geometric model corresponding to the industrial axial flow compressor, and perform a whole machine single-channel steady CFD calculation based on the target geometric model under the multiple stationary blade safe operation angles after setting the flow field boundary conditions to obtain a whole machine steady CFD flow field result;

[0077] The modal analysis unit 1003 is used to perform structural dynamics modal analysis on the first-stage moving blade and tenon overall model in the target geometric model to obtain the first four-order natural frequencies and vibration modes of the blade vibration;

[0078] A hybrid simulation unit 1004 is used to perform a steady + unsteady hybrid simulation based on the plurality of stationary blade safe operation angles to determine a mode and a pitch diameter that are most likely to be excited to cause asynchronous vibration;

[0079] The bidirectional fluid-solid coupling simulation unit 1005 is used to perform bidirectional fluid-solid coupling simulation for each of the stator blade safe operating angles based on the steady-state CFD flow field results of the whole machine and the modes and node diameters that are most likely to be excited to cause asynchronous vibrations, to obtain coupling simulation results, so as to analyze whether non-integer order vibration aeroelastic phenomenon will occur through the coupling simulation results; wherein, when the coupling simulation results indicate that the non-integer order vibration aeroelastic phenomenon does not occur, it is determined that the current stator blade safe operating angle is the minimum safe operating angle.

[0080] The device for determining the minimum safe operating angle of an industrial axial flow compressor with adjustable stator blades provided in the embodiment of the present application can be applied to a device for determining the minimum safe operating angle of an industrial axial flow compressor with adjustable stator blades, such as a computer. Fig.11 The hardware structure block diagram of the industrial axial compressor minimum safe operating angle determination device 1100 is shown. Fig.11 The hardware structure of the device for determining the minimum safe operating angle of an industrial axial compressor with adjustable stator blades may include a processor 111, a memory, a network interface 113, and a database 11213 connected through a system bus 114. The processor 111 is used to provide computing and control capabilities; the memory includes a non-volatile storage medium 1121 and an internal memory 1122, wherein the non-volatile storage medium 1121 stores an operating system 11211, a computer program 11212, and a database 11213, and the internal memory 1122 provides an operating environment for the operating system 11211 and the computer program 11212 in the non-volatile storage medium; the database 11213 is used to provide data such as the operating program of each system node; the network interface 113 is used to communicate with an external terminal through a network connection; when the computer program is executed by the processor 111, the method for determining the minimum safe operating angle of an industrial axial compressor described in any of the above embodiments is implemented.

[0081] The embodiment of the present application also provides a computer-readable storage medium, on which a computer program is stored, and when the computer program is executed by a processor, the method for determining the minimum safe operating angle of an industrial axial compressor in any embodiment of the present application is implemented. Specifically, a system or device equipped with a storage medium can be provided, on which a software program code that implements the functions of any of the above embodiments is stored, and a computer (or CPU or MPU) of the system or device reads and executes the program code stored in the storage medium.

[0082] In particular, according to an embodiment of the present invention, the process described above with reference to the flowchart can be implemented as a computer software program. For example, an embodiment of the present invention includes a computer program product, which includes a computer program carried on a computer-readable storage medium, and the computer program includes a program code for executing the method shown in the flowchart. In such an embodiment, the computer program can be downloaded and installed from a network through a communication part, and / or installed from a removable medium. When the computer program is executed by a central processing unit (CPU), the above-mentioned functions defined in the system of the present application are executed.

[0083] The flow chart and block diagram in the accompanying drawings illustrate the possible architecture, function and operation of the system, method and computer program product according to various embodiments of the present invention. In this regard, each box in the flow chart or block diagram can represent a module, a program segment, or a part of a code, and the above-mentioned module, program segment, or a part of a code contains one or more executable instructions for realizing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the box can also occur in a different order from the order marked in the accompanying drawings. For example, two boxes represented in succession can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram or flow chart, and the combination of the boxes in the block diagram or flow chart can be implemented with a dedicated hardware-based system that performs a specified function or operation, or can be implemented with a combination of dedicated hardware and computer instructions.

[0084] The units involved in the embodiments of the present invention may be implemented by software or hardware, and the units described may also be arranged in a processor. The names of these units do not, in some cases, limit the units themselves.

[0085] It should be noted that, although several modules or units of the equipment for action execution are mentioned in the above detailed description, this division is not mandatory. In fact, according to an embodiment 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. On the contrary, the features and functions of one module or unit described above can be further divided into being embodied by multiple modules or units.

[0086] Through the description of the above implementation, it is easy for those skilled in the art to understand that the example implementation described here can be implemented by software, or by software combined with necessary hardware. Therefore, the technical solution according to the implementation of the present invention can be embodied in the form of a software product, which can be stored in a non-volatile storage medium (which can be a CD-ROM, a USB flash drive, a mobile hard disk, etc.) or on a network, including several instructions to enable a computing device (which can be a personal computer, a server, a touch terminal, or a network device, etc.) to execute the method according to the implementation of the present invention.

[0087] The above embodiments are only used to illustrate the technical solution of the present application, but not to limit it. The present application is not limited to the exact structure described above and illustrated in the accompanying drawings, and it cannot be determined that the specific implementation of the present application is limited to these descriptions. For ordinary technicians in the technical field to which the present application belongs, various changes and modifications made without departing from the concept of the present application should be deemed to belong to the protection scope of the present application.

[0088] In the several embodiments provided in the present 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 only schematic, for example, the division of units is only a logical function division, and there may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interfaces, modules or units, which can be electrical, mechanical or other forms.

[0089] The above embodiments are only used to illustrate the technical solution of the present application, but not to limit it. The present application is not limited to the exact structure described above and illustrated in the accompanying drawings, and it cannot be determined that the specific implementation of the present application is limited to these descriptions. For ordinary technicians in the technical field to which the present application belongs, various changes and modifications made without departing from the concept of the present application should be deemed to belong to the protection scope of the present application.

Claims

1. A method for determining the minimum safe operating angle of an industrial axial compressor, characterized in that: include: Determining a plurality of safe operating angles of stationary blades corresponding to the industrial axial compressor; Establishing a geometric model based on the industrial axial compressor, meshing the geometric model, obtaining a target geometric model corresponding to the industrial axial compressor, and performing a single-channel steady-state CFD calculation of the whole machine based on the target geometric model under the safe operating angles of the multiple stator blades after setting the flow field boundary conditions, to obtain a steady-state CFD flow field result of the whole machine; Performing structural dynamics modal analysis on the first-stage moving blade and tenon overall model in the target geometric model to obtain the first four natural frequencies and vibration modes of the blade; Performing a steady + unsteady hybrid simulation based on the multiple stationary blade safe operation angles to determine the mode and pitch diameter that are most likely to be excited to cause asynchronous vibration; For each of the stator blade safe operating angles, a bidirectional fluid-solid coupling simulation is performed based on the steady-state CFD flow field results of the whole machine and the modes and node diameters that are most likely to be excited to cause asynchronous vibrations, to obtain a coupling simulation result, so as to analyze whether a non-integer order vibration aeroelastic phenomenon will occur through the coupling simulation result; wherein, when the coupling simulation result indicates that the non-integer order vibration aeroelastic phenomenon does not occur, the current stator blade safe operating angle is determined to be 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: The determining of the plurality of safe operating angles of the stator blades corresponding to the industrial axial compressor comprises: obtaining a plurality of values ​​of the safe operating angles of the stator blades of the industrial axial compressor by inferring based on empirical values; The flow field boundary condition is set under a selected working condition, and the selected working condition is a deep blockage working condition.

3. The method for determining the minimum safe operating angle of an industrial axial compressor according to claim 2, characterized in that: The SA turbulence model is used in the single-channel steady CFD calculation of the whole machine, and the SA turbulence model version 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 units are used, and contact constraints are set between the tenon and the blade 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 4, characterized in that: The steady + unsteady hybrid simulation is performed based on the plurality of stationary blade safe operation angles to determine the mode and pitch diameter that are most likely to be excited to cause asynchronous vibration, including: Analyze the unsteady flow characteristics and spatiotemporal modal characteristics of the tip area of ​​the first-stage moving blade based on the unsteady simulation domain; wherein the unsteady simulation domain is the full channel calculation domain of the first-stage moving blade and the directly adjacent blade row; Single-channel steady-state simulation is performed on each blade row within the steady-state simulation domain; wherein the steady-state simulation domain is the calculation domain where the blade rows other than the first-stage moving blades and the directly adjacent blade rows are located.

6. The method for determining the minimum safe operating angle of an industrial axial compressor according to claim 5 is characterized in that The method further comprises: When the coupling simulation result indicates that the non-integral-order vibration aeroelastic phenomenon occurs, it is determined that the stator blade angle under the current operating condition is an unsafe stator blade angle.

7. The method for determining the minimum safe operating angle of an industrial axial compressor according to claim 6, characterized in that: When the unsteady flow excitation frequency is locked to the natural frequency or the superposition of the natural frequency and the rotation frequency, the vibration stress in the coupling simulation result is stably maintained at a high level, and the coupling simulation result is characterized by the occurrence of the non-integral order vibration aeroelastic phenomenon.

8. A device for determining the minimum safe operating angle of an industrial axial flow compressor with adjustable stator blades, used to implement the method for determining the minimum safe operating angle of an industrial axial flow compressor according to any one of claims 1 to 7, characterized in that: include: A determination unit, used to determine a plurality of safe operating angles of stationary blades corresponding to the industrial axial compressor; A whole-machine single-channel steady-state CFD calculation unit is used to establish a geometric model based on the industrial axial compressor, and to mesh the geometric model to obtain a target geometric model corresponding to the industrial axial compressor, and to perform a whole-machine single-channel steady-state CFD calculation based on the target geometric model under the multiple stationary blade safe operation angles after setting the flow field boundary conditions, to obtain a whole-machine steady-state CFD flow field result; A modal analysis unit is used to perform structural dynamics modal analysis on the first-stage moving blade and tenon overall model in the target geometric model to obtain the first four-order natural frequencies and vibration modes of the blade vibration; A hybrid simulation unit, used for performing a steady + unsteady hybrid simulation based on the plurality of stationary blade safe operation angles, and determining a mode and a pitch diameter that are most likely to be excited to cause asynchronous vibration; A bidirectional fluid-solid coupling simulation unit is used to perform bidirectional fluid-solid coupling simulation for each of the stator blade safe operating angles based on the steady-state CFD flow field results of the whole machine and the modes and node diameters that are most likely to be excited to cause asynchronous vibrations, to obtain coupling simulation results, so as to analyze whether non-integer order vibration aeroelastic phenomenon will occur through the coupling simulation results; wherein, when the coupling simulation results indicate that the non-integer order vibration aeroelastic phenomenon does not occur, it is determined that the current stator blade safe operating angle is the minimum safe operating angle.

9. A device for determining the minimum safe operating angle of an industrial axial compressor with adjustable stator blades, comprising a memory and a processor, wherein the memory stores a computer program, characterized in that: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 7 are implemented.

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

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