Critical rotating speed determination method and device, equipment and storage medium

Abstract

The invention relates to the technical field of hydraulic equipment, and discloses a critical rotation speed determination method, device and equipment and a storage medium. Dynamic characteristics of a target pumping and storage unit are analyzed, and a dynamic characteristic coefficient of the target pumping and storage unit is determined; constructing an unbalanced mass force model, an unbalanced magnetic pulling force model and an unbalanced water pressure model of the target pumped storage unit; based on the dynamic characteristic coefficient, the unbalanced mass force model, the unbalanced magnetic pulling force model and the unbalanced water pressure model, constructing a rotor system motion model of the target pumping and storage unit; based on the rotor system motion model, modal frequencies corresponding to the multiple rotating speeds are determined; based on the modal frequency, a critical rotational speed is determined. Therefore, a guide bearing and sealing dynamic characteristic model and exciting force models such as unbalanced mass force, unbalanced magnetic pulling force and unbalanced water pressure are coupled, so that the constructed rotor system motion model is more practical, and the accuracy of the calculated critical rotating speed is ensured.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of hydraulic equipment, in particular to a critical speed determination method, device, equipment and storage medium. BACKGROUND

[0002] The rotor of the pumped storage unit is mainly composed of a generator motor, a pump turbine, a main shaft and other components. When the operating speed of the pumped storage unit approaches or reaches the natural frequency of the rotor, resonance phenomenon occurs, and the vibration amplitude of the rotor increases significantly. The speed is the critical speed of the rotor. When the rotor resonates, the rotor vibrates abnormally and stress concentrates, which may cause damage to the unit. Therefore, a method is needed to accurately calculate the critical speed to avoid resonance of the pumped storage unit during operation and ensure the stability and safety of the pumped storage unit. SUMMARY

[0003] Therefore, the present application provides a critical speed determination method, device, equipment and storage medium to accurately calculate the critical speed.

[0004] In a first aspect, the present application provides a critical speed determination method, which comprises: analyzing the dynamic characteristics of the target pumped storage unit to determine the dynamic characteristic coefficients of the target pumped storage unit, wherein the dynamic characteristic coefficients include the dynamic characteristic coefficients of the guide bearing and the dynamic characteristic coefficients of the ring seal; constructing an unbalanced mass force model, an unbalanced magnetic pull model and an unbalanced water pressure model of the target pumped storage unit; constructing a rotor system motion model of the target pumped storage unit based on the dynamic characteristic coefficients, the unbalanced mass force model, the unbalanced magnetic pull model and the unbalanced water pressure model; determining the modal frequencies corresponding to a plurality of rotational speeds based on the rotor system motion model; determining the critical speed based on the modal frequencies.

[0005] In an optional embodiment, analyzing the dynamic characteristics of the target pumped storage unit to determine the dynamic characteristic coefficients of the target pumped storage unit comprises: analyzing the oil film force of the guide bearing of the target pumped storage unit based on a preset analysis algorithm to obtain the oil film stiffness coefficient and the oil film damping coefficient, wherein the dynamic characteristic coefficients of the guide bearing include the oil film stiffness coefficient and the oil film damping coefficient.

[0006] In an optional embodiment, analyzing the dynamic characteristics of the target pumped storage unit to determine the dynamic characteristic coefficients of the target pumped storage unit comprises: The first direction and the second direction of the sealing force component acting on the rotor are determined based on the relationship between the sealing force of the ring seal of the target pumped storage unit and displacement, velocity, and acceleration, and a dynamic characteristic coefficient of the ring seal is obtained.

[0007] In an optional embodiment, an unbalanced mass force model of the target pumped storage unit is constructed, including: The unbalanced mass is obtained based on a rotor dynamic balancing test. The unbalanced mass force component of the rotor in the first direction and the second direction is respectively constructed based on the unbalanced mass, the eccentric moment of the rotor, and the initial phase, and an unbalanced mass force model is obtained.

[0008] In an optional embodiment, an unbalanced magnetic pull force model of the target pumped storage unit is constructed, including: The unbalanced magnetic pull force model is obtained by performing Maxwell stress integration based on the generator motor of the target pumped storage unit.

[0009] In an optional embodiment, an unbalanced water pressure force model of the target pumped storage unit is constructed, including: The unbalanced water pressure force component in the first direction is obtained by performing integral calculation on the water pressure force acting on the runner in the first direction. The unbalanced water pressure force component in the second direction is obtained by performing integral calculation on the water pressure force acting on the runner in the second direction.

[0010] In an optional embodiment, a rotor system motion model of the target pumped storage unit is constructed based on the dynamic characteristic coefficient, the unbalanced mass force model, the unbalanced magnetic pull force model, and the unbalanced water pressure force model, including: The external force model in the rotor system motion model is determined based on the unbalanced mass force model, the unbalanced magnetic pull force model, and the unbalanced water pressure force model. The rotor system motion model is constructed based on the dynamic characteristic coefficient and the external force model.

[0011] In a second aspect, the present application provides a critical speed determination device, which comprises: A characteristic coefficient determination module is configured to analyze the dynamic characteristics of the target pumped storage unit and determine the dynamic characteristic coefficient of the target pumped storage unit, wherein the dynamic characteristic coefficient includes the dynamic characteristic coefficient of the guide bearing and the dynamic characteristic coefficient of the ring seal. A first model construction module is configured to construct the unbalanced mass force model, the unbalanced magnetic pull force model, and the unbalanced water pressure force model of the target pumped storage unit. A second model construction module is configured to construct the rotor system motion model of the target pumped storage unit based on the dynamic characteristic coefficient, the unbalanced mass force model, the unbalanced magnetic pull force model, and the unbalanced water pressure force model. a modal frequency determination module, configured to determine modal frequencies corresponding to a plurality of rotating speeds respectively based on a rotor system motion model; a critical speed determination module, configured to determine a critical speed based on the modal frequencies.

[0012] In a third aspect, the present application provides a computer device, comprising a memory and a processor, the memory and the processor are communicatively connected with each other, the memory stores computer instructions, and the processor executes the computer instructions to perform the critical speed determination method in the first aspect or any of the corresponding embodiments.

[0013] In a fourth aspect, the present application provides a computer readable storage medium, which stores computer instructions, and the computer instructions are used to make a computer perform the critical speed determination method in the first aspect or any of the corresponding embodiments.

[0014] In a fifth aspect, the present application provides a computer program product, which comprises computer instructions, and the computer instructions are used to make a computer perform the critical speed determination method in the first aspect or any of the corresponding embodiments.

[0015] The critical speed determination method provided by the embodiments of the present application can fully consider the influence of the ring seal and fluid additional effect on the critical speed in the calculation process of the critical speed by analyzing the dynamic characteristics of the target pumped storage unit, obtaining the dynamic characteristic coefficients of the guide bearing and the ring seal of the target pumped storage unit, and constructing an unbalanced mass force model, an unbalanced magnetic pull model and an unbalanced water pressure model of the target pumped storage unit, and constructing a rotor system motion model of the target pumped storage unit based on the dynamic characteristic coefficients, the unbalanced mass force model, the unbalanced magnetic pull model and the unbalanced water pressure model, so as to couple the guide bearing, the sealing dynamic characteristic model and the unbalanced mass force, the unbalanced magnetic pull and the unbalanced water pressure, etc. excitation force model, so that the constructed rotor system motion model is more in line with the actual situation, and the accuracy of the calculated critical speed is ensured. BRIEF DESCRIPTION OF DRAWINGS

[0016] In order to more clearly illustrate the specific embodiments of the present application or the technical solutions in the prior art, the drawings needed in the specific embodiments or prior art description will be briefly introduced below. Obviously, the drawings in the following description are some embodiments of the present application, and those skilled in the art can also obtain other drawings according to these drawings without creative labor.

[0017] Figure 1 is a flowchart of the critical speed determination method according to the embodiments of the present application; Figure 2is a flowchart of another critical speed determination method according to an embodiment of the present application; Figure 3 is a schematic diagram of an equivalent model of a guide bearing in a critical speed determination method according to an embodiment of the present application; Figure 4 is a schematic diagram of bearing bush distribution of a guide bearing in a critical speed determination method according to an embodiment of the present application; Figure 5 is a flowchart of another critical speed determination method according to an embodiment of the present application; Figure 6 is a flowchart of yet another critical speed determination method according to an embodiment of the present application; Figure 7 is a structural block diagram of a critical speed determination device according to an embodiment of the present application; Figure 8 is a hardware structure schematic diagram of a computer device according to an embodiment of the present application. DETAILED DESCRIPTION

[0018] To make the objectives, technical solutions and advantages of embodiments of the present application clearer, the technical solutions in embodiments of the present application will be described clearly and completely below with reference to the drawings in embodiments of the present application. Obviously, the described embodiments are some but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the present application.

[0019] The rotor, a core component of a pumped storage unit, is mainly composed of a generator motor, a pump turbine, a main shaft and the like. When the operating speed of the pumped storage unit approaches or reaches the natural frequency of the rotor, resonance phenomenon occurs, and the vibration amplitude of the rotor significantly increases. The speed is the critical speed of the rotor. When the rotor resonates, the rotor appears abnormal vibration and stress concentration, and there is a risk of causing damage to the unit.

[0020] In related technologies, in the calculation of the critical speed, the guide bearing is usually regarded as rigid support, or the dynamic characteristic coefficient of the guide bearing is regarded as an eight-parameter model to improve the accuracy of the critical speed. In actual engineering applications, after completing the structure design of the pumped storage unit, only a few specific bearing stiffness values are usually selected to calculate the critical speed to evaluate whether the design has sufficient safety margin. However, the actual rotor system of the pumped storage unit is very complex, and the critical speed is not only affected by the dynamic characteristics of the guide bearing and the dynamic characteristics of the annular seal, but also affected by the residual unbalanced mass, the unbalanced magnetic pull of the generator, the fluid excitation force, the misalignment of the rotor axis and the like. Therefore, the calculation of the critical speed in related technologies cannot match the actual design of the pumped storage unit, and the calculated critical speed is not accurate enough.

[0021] Based on this, the embodiment of the present application provides a critical speed determination method, which comprises: analyzing the dynamic characteristics of a target pumped storage unit to determine the dynamic characteristic coefficients of the target pumped storage unit, wherein the dynamic characteristic coefficients comprise the dynamic characteristic coefficients of guide bearings and the dynamic characteristic coefficients of ring seals; constructing an unbalanced mass force model, an unbalanced magnetic pull model and an unbalanced water pressure model of the target pumped storage unit; constructing a rotor system motion model of the target pumped storage unit based on the dynamic characteristic coefficients, the unbalanced mass force model, the unbalanced magnetic pull model and the unbalanced water pressure model; and determining the modal frequencies corresponding to a plurality of rotating speeds based on the rotor system motion model, and determining the critical speed based on the modal frequencies. Thus, by analyzing the dynamic characteristics of the target pumped storage unit, the dynamic characteristic coefficients of the guide bearings and the dynamic characteristic coefficients of the ring seals of the target pumped storage unit are obtained, so that the influence of the ring seals and the fluid additional effect on the critical speed is fully considered in the calculation process of the critical speed. Meanwhile, the unbalanced mass force model, the unbalanced magnetic pull model and the unbalanced water pressure model of the target pumped storage unit are constructed, and the rotor system motion model of the target pumped storage unit is constructed based on the dynamic characteristic coefficients, the unbalanced mass force model, the unbalanced magnetic pull model and the unbalanced water pressure model, so that the guide bearing, the sealing dynamic characteristic model and the unbalanced mass force, the unbalanced magnetic pull and the unbalanced water pressure excitation force model are coupled, the rotor system motion model constructed is more in line with the actual situation, and the accuracy of the critical speed calculated is ensured.

[0022] According to the embodiment of the present application, a critical speed determination method is provided, and it should be noted that the steps shown in the flowchart of the drawings can be executed in a computer system such as a group of computer executable instructions, and although the logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0023] In this embodiment, a critical speed determination method is provided, which can be used in hydraulic machinery equipment, Figure 1 is a flowchart of the critical speed determination method according to the embodiment of the present application, as Figure 1 shown, the flowchart comprises the following steps: Step S101, analyzing the dynamic characteristics of a target pumped storage unit to determine the dynamic characteristic coefficients of the target pumped storage unit.

[0024] In the embodiment of the present application, the dynamic characteristic coefficients of the target pumped storage unit comprise the dynamic characteristic coefficients of the guide bearings and the dynamic characteristic coefficients of the ring seals in the target pumped storage unit.

[0025] The dynamic characteristic coefficient of the guide bearing is used for quantifying the stiffness and damping response of the oil film force to the rotor micro disturbance, and generally includes four stiffness coefficients and four damping coefficients; the dynamic characteristic of the guide bearing can be analyzed by using a plurality of methods such as a finite difference method, a finite element method, a numerical simulation method and a test method, and the dynamic characteristic coefficient of the guide bearing is obtained. The dynamic characteristic coefficient of the annular seal is used for representing the response of the turbulent fluid in the sealing gap to the rotor vibration, and generally includes two stiffness coefficients, two damping coefficients and two mass coefficients; the relationship between the sealing force and the displacement, velocity and acceleration of the annular seal can be analyzed, and the dynamic characteristic coefficient of the annular seal is obtained.

[0026] In step S102, the unbalanced mass force model, the unbalanced magnetic pull model and the unbalanced water pressure model of the target pumped storage unit are constructed.

[0027] In the embodiment of the present application, due to the influence of factors such as material defects, bending deformation and machining precision, the rotor often has a certain mechanical imbalance, which generates unbalanced mass force, unbalanced magnetic pull and unbalanced water pressure and the like.

[0028] The unbalanced mass force is the centrifugal force generated due to the uneven distribution of the rotor mass; when the center of mass deviates from the rotation axis, the centrifugal force will cause periodic vibration, and further affect the critical speed; the unbalanced mass force model of the target pumped storage unit can be constructed according to the principle of centrifugal force. The unbalanced magnetic pull is the one-way magnetic attraction force generated due to the asymmetry of the rotor and the stator magnetic field in the generator motor, which will cause the rotor vibration to intensify, and further affect the critical speed; the unbalanced magnetic pull model of the target pumped storage unit can be constructed according to the Maxwell stress tensor or finite element analysis. The unbalanced water pressure is the resultant force generated due to the uneven pressure distribution of the flow passage or impeller on both sides in the fluid machine, i.e. water pump and water turbine, which will cause axial or radial vibration, and further affect the critical speed; the unbalanced water pressure model of the target pumped storage unit can be constructed by analyzing the pressure integration or momentum theorem based on fluid mechanics.

[0029] In step S103, the rotor system motion model of the target pumped storage unit is constructed based on the dynamic characteristic coefficient, the unbalanced mass force model, the unbalanced magnetic pull model and the unbalanced water pressure model.

[0030] In the embodiment of the present application, the rotor system motion model is used for describing the dynamic behavior of the target pumped storage unit, and mainly relates to the dynamic behavior of the rotor under the action of inertial force, elastic force, damping force and external excitation. The model is used for analyzing the critical speed, stability, unbalanced response and other key dynamic characteristics. The unbalanced mass force model, the unbalanced magnetic pull model and the unbalanced water pressure model are taken as the external excitation of the target pumped storage unit, and the rotor system motion model of the target pumped storage unit is constructed in combination with the dynamic characteristic coefficient.

[0031] In step S104, modal frequencies corresponding to the plurality of rotational speeds are determined respectively based on the rotor system motion model.

[0032] In the embodiment of the present application, the modal frequency is the natural frequency of the system under a specific vibration mode. When the rotational speed of the rotor is equal to or close to the modal frequency, the system resonates, and the rotational speed of the rotor at this time is the critical speed. Therefore, the critical speed can be determined based on the relationship between the rotational speed and the modal frequency. Correspondingly, the rotor system motion model is analyzed and solved at different rotational speeds based on the rotor system motion model, and the modal frequencies corresponding to the plurality of different rotational speeds are obtained.

[0033] In step S105, the critical speed is determined based on the modal frequencies.

[0034] In the embodiment of the present application, the modal frequencies corresponding to the plurality of rotational speeds obtained by solving are used to fit the Campbell diagram of the change of the modal frequency with the rotational speed. In the Campbell diagram, the intersection point of the modal frequency curve and the rotational speed line is determined to obtain the critical speed.

[0035] The critical speed determination method provided in the embodiment of the present application comprises: analyzing the dynamic characteristics of the target pumped storage unit to determine the dynamic characteristic coefficients of the target pumped storage unit, wherein the dynamic characteristic coefficients include the dynamic characteristic coefficients of the guide bearing and the dynamic characteristic coefficients of the ring seal; constructing an unbalanced mass force model, an unbalanced magnetic pull model and an unbalanced water pressure model of the target pumped storage unit; constructing a rotor system motion model of the target pumped storage unit based on the dynamic characteristic coefficients, the unbalanced mass force model, the unbalanced magnetic pull model and the unbalanced water pressure model; determining modal frequencies corresponding to a plurality of rotational speeds respectively based on the rotor system motion model; and determining the critical speed based on the modal frequencies. Thus, by analyzing the dynamic characteristics of the target pumped storage unit, the dynamic characteristic coefficients of the guide bearing and the dynamic characteristic coefficients of the ring seal of the target pumped storage unit are obtained, so that the influence of the ring seal and the fluid additional effect on the critical speed is fully considered in the calculation process of the critical speed. At the same time, the unbalanced mass force model, the unbalanced magnetic pull model and the unbalanced water pressure model of the target pumped storage unit are constructed, and the rotor system motion model of the target pumped storage unit is constructed based on the dynamic characteristic coefficients, the unbalanced mass force model, the unbalanced magnetic pull model and the unbalanced water pressure model, so as to couple the guide bearing, the sealing dynamic characteristic model and the unbalanced mass force, the unbalanced magnetic pull and the unbalanced water pressure excitation force model, so that the rotor system motion model constructed is more in line with the actual situation, and the accuracy of the critical speed calculated is ensured.

[0036] In the embodiment, a critical speed determination method is provided, which can be used in a hydraulic mechanical equipment, Figure 2 is a flowchart of another critical speed determination method according to the embodiment of the present application.Figure 2 As shown in the figure, the flow includes the following steps: In step S201, the dynamic characteristics of the target pumped storage unit are analyzed to determine the dynamic characteristic coefficients of the target pumped storage unit.

[0037] In the embodiment of the present application, the analysis of the dynamic characteristics of the target pumped storage unit includes the analysis of the dynamic characteristics of the guide bearing and the analysis of the dynamic characteristics of the ring seal. Specifically, step S201 includes the following steps: In step S2011, the oil film force of the guide bearing of the target pumped storage unit is analyzed based on a preset analysis algorithm to obtain the oil film stiffness coefficient and the oil film damping coefficient.

[0038] In the embodiment of the present application, the dynamic characteristic coefficients of the guide bearing include the oil film stiffness coefficient and the oil film damping coefficient. Figure 3 is the equivalent model of the guide bearing in the critical speed determination method according to the embodiment of the present application, as shown in the figure, Figure 3 The radial force of the guide bearing can be decomposed into components in the first direction and the second direction using the following formula (1): Formula (1) Wherein, 、 are the components of the radial force of the guide bearing in the first direction and the second direction, respectively; is the oil film stiffness matrix; is the oil film damping matrix; 、 is the displacement vector component; , is the velocity vector component. The first direction is the X direction and the second direction is the Y direction.

[0039] In the embodiment of the present application, based on the equivalent model of the guide bearing shown in Figure 3 The oil film force of the guide bearing is analyzed using a preset analysis algorithm to obtain the oil film stiffness coefficient and the oil film damping coefficient. The preset analysis algorithm can include numerical simulation methods, analytical calculation methods, and experimental test methods, which are not limited here.

[0040] In an alternative embodiment, when the numerical simulation method is used for analysis, a three-dimensional thermal elastohydrodynamic calculation model of the guide bearing is constructed, and the physical parameters of the target pumped storage unit guide bearing, such as material density, elastic modulus, and Poisson's ratio, are input into the three-dimensional thermal elastohydrodynamic calculation model for three-dimensional thermal elastohydrodynamic numerical simulation, so as to obtain the oil film pressure. The oil film force of the guide bearing is obtained by integrating the oil film pressure, and the dynamic characteristic coefficients are obtained by differentiating the oil film force of the guide bearing.

[0041] In an alternative embodiment, when the analytical calculation method is used for analysis, the finite difference method can be used to construct and solve the Reynolds equation of the finite length bearing to obtain the oil film pressure, as shown in the following formula (2): Formula (2) Wherein, is the coordinate in the circumferential direction of the rotor, is the coordinate in the radial direction of the rotor; is the oil film pressure; is the whirl speed of the shaft; is the dynamic viscosity of the fluid; is the time.

[0042] Figure 4 is the distribution diagram of the bearing pad of the guide bearing in the critical speed determination method according to the embodiment of the application, as shown in Figure 4 After the oil film pressure is obtained, the oil film pressure is integrated to obtain the oil film force of each bearing pad in the guide bearing, as shown in the following formula (3): Formula (3) Wherein, is the oil film force provided by the bearing pad to the shaft; is the area of the bearing pad.

[0043] Based on the oil film force of each bearing pad in the guide bearing, the decomposition in the first direction and the second direction is performed to obtain the radial force components of the guide bearing in the first direction and the second direction, as shown in the following formula (4):

[0044] Formula (4) Wherein, is the radial force component of the guide bearing in the first direction, is the radial force component of the guide bearing in the second direction; is the guide bearing pad angle; is the number of guide bearing pads.

[0045] Based on the radial force components of the guide bearing in the first direction and the second direction, the derivation is performed to obtain the oil film stiffness coefficient and the oil film damping coefficient of the guide bearing, as shown in the following formula (5):

[0046] Formula (5) Wherein, is the oil film stiffness coefficient, is the oil film damping coefficient.

[0047] In an alternative embodiment, when the analysis is performed using the test method, an oil film pressure measuring point is installed on the pad surface of the guide bearing, the oil film pressure is obtained by testing the oil film pressure measuring point, the oil film force of the guide bearing is obtained by integrating the oil film pressure, and the dynamic characteristic coefficient is obtained by differentiating the oil film force of the guide bearing.

[0048] Step S2012, based on the relationship between the sealing force and the displacement, velocity and acceleration of the annular seal of the target pumped storage unit, the sealing force components in the first direction and the second direction acting on the rotor are determined, and the dynamic characteristic coefficient of the annular seal is obtained.

[0049] In the embodiment of the application, the relationship between the sealing force and the displacement, velocity and acceleration of the annular seal is shown in the following formula (6): Formula (6) Wherein, is the force of the sealing fluid on the rotor in the first direction, is the force of the sealing fluid on the rotor in the second direction; is the main stiffness coefficient, is the cross stiffness coefficient; is the main damping coefficient, is the cross damping coefficient; is the main mass coefficient; , is the displacement vector component; , is the velocity vector component; , is the acceleration vector component.

[0050] At the initial moment, i.e. t = 0, = 0, = 0, = 0, , = 0, . Wherein, is the displacement of the whirl center, is the rotor whirl velocity. Based on this analysis, the dynamic characteristic coefficient of the annular seal is obtained, as shown in the following formula (7):

[0051] Formula (7) Step S202, constructing the unbalanced mass force model, the unbalanced magnetic pull model and the unbalanced water pressure model of the target pumped storage unit. For details, please refer to the step S102 of the embodiment shown in Figure 1 , which will not be repeated here.

[0052] In step S203, a rotor system motion model of the target pumped storage unit is constructed based on the dynamic characteristic coefficient, the unbalanced mass force model, the unbalanced magnetic pull model and the unbalanced water pressure model. For details, please refer to Figure 1 In step S103 of the embodiment shown in the figure, no further elaboration is given here.

[0053] In step S204, modal frequencies corresponding to multiple rotation speeds are determined based on the rotor system motion model. For details, please refer to Figure 1 In step S104 of the embodiment shown in the figure, no further elaboration is given here.

[0054] In step S205, the critical rotation speed is determined based on the modal frequencies. For details, please refer to Figure 1 In step S105 of the embodiment shown in the figure, no further elaboration is given here.

[0055] The critical rotation speed determination method provided in the embodiment fully considers the influence of the annular seal and fluid additional effect on the critical rotation speed in the calculation process of the critical rotation speed, so as to ensure the accuracy of the calculated critical rotation speed.

[0056] In the embodiment, a critical rotation speed determination method is provided, which can be used in a hydraulic mechanical equipment, Figure 5 is a flowchart of another critical rotation speed determination method according to an embodiment of the present application, which, as shown in the figure, includes the following steps: Figure 5 In step S501, the dynamic characteristic of the target pumped storage unit is analyzed to determine the dynamic characteristic coefficient of the target pumped storage unit. For details, please refer to Figure 1 In step S101 of the embodiment shown in the figure, no further elaboration is given here.

[0057] In step S502, an unbalanced mass force model, an unbalanced magnetic pull model and an unbalanced water pressure model of the target pumped storage unit are constructed.

[0058] In the embodiment, the unbalanced mass force model, the unbalanced magnetic pull model and the unbalanced water pressure model of the target pumped storage unit are respectively constructed. Specifically, step S502 can include the following steps: In step S5021, the unbalanced mass is obtained.

[0059] In step S5022, based on the unbalanced mass, the eccentric moment of the rotor and the initial phase, the unbalanced mass force components of the rotor in the first direction and the second direction are respectively constructed to obtain the unbalanced mass force model.

[0060] ​In the embodiment of the present application, steps S5021 and S5022 are used to construct the unbalanced mass force model. The unbalanced mass is obtained based on the rotor dynamic balancing test. After obtaining the unbalanced mass, the unbalanced mass force components of the rotor in the first direction and the second direction are constructed based on the centrifugal force formula, and the unbalanced mass force model is obtained, as shown in the following formula (8):

[0061] Formula (8) Wherein, is the unbalanced mass force component of the rotor in the first direction, is the unbalanced mass force component of the rotor in the second direction; is the maximum unbalanced mass; is the eccentricity moment; is the initial phase.

[0062] Step S5023, Maxwell stress integration is performed based on the target pumped storage unit generator to obtain an unbalanced magnetic pull model.

[0063] In the embodiment of the present application, step S5023 is used to construct the unbalanced magnetic pull model. Specifically, Maxwell stress integration is performed on the target pumped storage unit generator to obtain the unbalanced magnetic pull model, as shown in the following formula (9): Formula (9) Wherein, is the unbalanced magnetic pull; is the length of the generator rotor, is the diameter of the generator rotor; is the air permeability coefficient; is the air gap fundamental magnetic motive force coefficient; is the excitation current; is the average length of the air gap; is the rotor eccentricity.

[0064] Step S5024, the water pressure acting on the runner in the first direction is integrated and calculated to obtain the unbalanced water pressure component in the first direction.

[0065] Step S5025, the water pressure acting on the runner in the second direction is integrated and calculated to obtain the unbalanced water pressure component in the second direction.

[0066] In the embodiment of the present application, steps S5024 and S5025 are used to construct the unbalanced water pressure model. Specifically, the water pressure acting on the runner in the first direction and the second direction is integrated and calculated respectively to obtain the unbalanced water pressure components in the first direction and the second direction, as shown in the following formula (10):

[0067] Formula (10) in, is the projection of the infinitesimal area of ​​the inner surface of the runner on the normal plane in the first direction, is the projection of the infinitesimal area of ​​the inner surface of the runner on the normal plane in the second direction; is the unbalanced water pressure component in the first direction, is the unbalanced water pressure component in the second direction.

[0068] Step S503: Based on the dynamic characteristic coefficient, the unbalanced mass force model, the unbalanced magnetic pull model and the unbalanced water pressure model, a rotor system motion model of the target pumped storage unit is constructed. Figure 1 Step S103 of the illustrated embodiment will not be described in detail here.

[0069] Step S504: Based on the rotor system motion model, determine the modal frequencies corresponding to the multiple speeds. Figure 1 Step S104 of the illustrated embodiment will not be described in detail here.

[0070] Step S505: Determine the critical speed based on the modal frequency. Figure 1 Step S105 of the illustrated embodiment will not be described in detail here.

[0071] The critical speed determination method provided in an embodiment of the present invention constructs an unbalanced mass force model, an unbalanced magnetic pull model and an unbalanced water pressure model of the target pumped storage unit, and constructs a rotor system motion model of the target pumped storage unit based on the dynamic characteristic coefficient, the unbalanced mass force model, the unbalanced magnetic pull model and the unbalanced water pressure model, thereby coupling the guide bearing and seal dynamic characteristic models with the excitation force models such as the unbalanced mass force, the unbalanced magnetic pull and the unbalanced water pressure, so that the constructed rotor system motion model is more in line with reality, and the accuracy of the calculated critical speed is guaranteed.

[0072] In this embodiment, a critical speed determination method is provided, which can be used in hydraulic machinery equipment. Figure 6 FIG. 1 is a flow chart of another critical speed determination method according to an embodiment of the present invention. Figure 6 As shown, the process includes the following steps: Step S601: Analyze the power characteristics of the target pumped storage unit and determine the power characteristic coefficient of the target pumped storage unit. Figure 1 Step S101 of the illustrated embodiment will not be described in detail here.

[0073] Step S602, an unbalanced mass force model, an unbalanced magnetic pull model and an unbalanced water pressure model of the target pumped storage unit are constructed. For details, please refer to Figure 1 Step S102 of the embodiment shown in the figure will not be repeated here.

[0074] Step S603, a rotor system motion model of the target pumped storage unit is constructed based on the dynamic characteristic coefficient, the unbalanced mass force model, the unbalanced magnetic pull model and the unbalanced water pressure model.

[0075] Specifically, step S603 includes: Step S6031, an external force model in the rotor system motion model is determined based on the unbalanced mass force model, the unbalanced magnetic pull model and the unbalanced water pressure model.

[0076] In the embodiment of the application, the rotor system motion model can be shown in the following formula (11): Formula (11) Wherein, is a mass matrix, is a damping matrix, is a stiffness matrix, is a gyro matrix; is a rotor whirl speed; is a generalized displacement vector of the rotor system, is a generalized velocity vector of the rotor system, is a generalized acceleration vector of the rotor system; is a generalized external force acting on the rotor system.

[0077] In the embodiment of the application, the generalized external force on the rotor system includes the unbalanced mass force, the unbalanced magnetic pull and the unbalanced water pressure. The unbalanced mass force model, the unbalanced magnetic pull model and the unbalanced water pressure model are added to obtain the external force model of the rotor system motion model.

[0078] Step S6032, the rotor system motion model is constructed based on the dynamic characteristic coefficient and the external force model.

[0079] In the embodiment of the application, the dynamic characteristic coefficient is embedded in the rotor system motion model in the form of a corresponding matrix, and the external force model is embedded in the rotor system motion model in the form of an external force, to obtain the rotor system motion model.

[0080] Step S604, modal frequencies corresponding to multiple rotation speeds are respectively determined based on the rotor system motion model. For details, please refer to Figure 1 Step S104 of the embodiment shown in the figure will not be repeated here.

[0081] Step S605, determining the critical speed based on the modal frequency. For details, please refer to Figure 1 Step S105 of the embodiment shown will not be described here.

[0082] The critical speed determination method provided by the embodiment of the application, constructs an unbalanced mass force model, an unbalanced magnetic pull model and an unbalanced water pressure model of the target pumped storage unit, constructs a rotor system motion model of the target pumped storage unit based on the dynamic characteristic coefficient, the unbalanced mass force model, the unbalanced magnetic pull model and the unbalanced water pressure model, thereby coupling the dynamic characteristic model of the guide bearing and the sealing and the unbalanced mass force, the unbalanced magnetic pull and the unbalanced water pressure, so that the rotor system motion model constructed is more in line with the actual situation, and the accuracy of the critical speed calculated is ensured.

[0083] In the embodiment, a critical speed determination device is also provided, which is used to implement the above-mentioned embodiments and preferred embodiments, and will not be described here. As used below, the term "module" can be a combination of software and / or hardware that implements a predetermined function. Although the device described in the following embodiments is preferably implemented in software, implementation of hardware, or a combination of software and hardware, is also possible and contemplated.

[0084] The embodiment provides a critical speed determination device, as shown in the figure, comprising: Figure 7 as shown, comprising: The characteristic coefficient determination module 701 is configured to analyze the dynamic characteristics of the target pumped storage unit and determine the dynamic characteristic coefficient of the target pumped storage unit, wherein the dynamic characteristic coefficient includes the dynamic characteristic coefficient of the guide bearing and the dynamic characteristic coefficient of the annular seal. The first model construction module 702 is configured to construct an unbalanced mass force model, an unbalanced magnetic pull model and an unbalanced water pressure model of the target pumped storage unit. The second model construction module 703 is configured to construct a rotor system motion model of the target pumped storage unit based on the dynamic characteristic coefficient, the unbalanced mass force model, the unbalanced magnetic pull model and the unbalanced water pressure model. The modal frequency determination module 704 is configured to determine the modal frequency corresponding to each of a plurality of rotational speeds based on the rotor system motion model. The critical speed determination module 705 is configured to determine the critical speed based on the modal frequency.

[0085] In an optional embodiment, the characteristic coefficient determination module 701 comprises: The oil film force analysis unit is configured to analyze the oil film force of the guide bearing of the target pumped storage unit based on a preset analysis algorithm to obtain an oil film stiffness coefficient and an oil film damping coefficient, wherein the dynamic characteristic coefficient of the guide bearing includes the oil film stiffness coefficient and the oil film damping coefficient.

[0086] In an alternative embodiment, the characteristic coefficient determination module 701 comprises: The sealing force analysis unit is configured to determine the sealing force components in the first direction and the second direction acting on the rotor based on the relationship between the sealing force and the displacement, the speed, and the acceleration of the annular seal of the target pumped storage unit, to obtain the dynamic characteristic coefficient of the annular seal.

[0087] In an alternative embodiment, the first model construction module 702 comprises: The unbalance mass acquisition unit is configured to acquire the unbalance mass, which is obtained based on the rotor dynamic balancing test. The unbalance mass force model construction unit is configured to construct the unbalance mass force components of the rotor in the first direction and the second direction respectively based on the unbalance mass, the eccentricity moment of the rotor, and the initial phase, to obtain the unbalance mass force model.

[0088] In an alternative embodiment, the first model construction module 702 comprises: The unbalance magnetic pull force model construction unit is configured to perform Maxwell stress integration based on the generator motor of the target pumped storage unit, to obtain the unbalance magnetic pull force model.

[0089] In an alternative embodiment, the first model construction module 702 comprises: The first unbalance water pressure calculation unit is configured to perform integral calculation on the water pressure acting on the first direction of the runner, to obtain the unbalance water pressure component in the first direction. The second unbalance water pressure calculation unit is configured to perform integral calculation on the water pressure acting on the second direction of the runner, to obtain the unbalance water pressure component in the second direction.

[0090] In an alternative embodiment, the second model construction module 703 comprises: The external force model construction unit is configured to determine the external force model in the rotor system motion model based on the unbalance mass force model, the unbalance magnetic pull force model, and the unbalance water pressure model. The rotor system motion model construction unit is configured to construct the rotor system motion model based on the dynamic characteristic coefficient and the external force model.

[0091] The further function descriptions of the above-mentioned various modules and units are the same as those of the above-mentioned corresponding embodiments, which will not be described here again.

[0092] The critical speed determination device in this embodiment is presented in the form of a functional unit, where the unit refers to an ASIC (Application Specific Integrated Circuit) circuit, a processor and memory that executes one or more software or fixed programs, and / or other devices that can provide the above functions.

[0093] The embodiment of the present invention also provides a computer device having the above Figure 8 The critical speed determination device shown.

[0094] See also Figure 8 , Figure 8 is a structural diagram of a computer device provided by an optional embodiment of the present invention, such as Figure 8 As shown, the computer device includes: one or more processors 10, memory 20, and interfaces for connecting various components, including high-speed interfaces and low-speed interfaces. Various components utilize different buses to communicate with each other and can be installed on a common mainboard or installed in other ways as needed. The processor can process the instructions executed in the computer device, including instructions stored in the memory or on the memory to display the graphical information of the GUI on an external input / output device (such as, a display device coupled to the interface). In some optional embodiments, if necessary, multiple processors and / or multiple buses can be used together with multiple memories and multiple memories. Equally, multiple computer devices can be connected, and each device provides part of the necessary operations (for example, as a server array, a group of blade servers, or a multi-processor system). Figure 8 A processor 10 is taken as an example.

[0095] The processor 10 may be a central processing unit, a network processor, or a combination thereof. The processor 10 may further include a hardware chip. The hardware chip may be an application-specific integrated circuit, a programmable logic device, or a combination thereof. The programmable logic device may be a complex programmable logic device, a field programmable gate array, a general purpose array logic, or any combination thereof.

[0096] The memory 20 stores instructions that can be executed by at least one processor 10, so that the at least one processor 10 executes the method shown in the above embodiment.

[0097] The memory 20 can include a program storage area and a data storage area. The program storage area can store an operating system, application programs required for at least one function, etc. The data storage area can store data created by the computer device, etc. In addition, the memory 20 can include a high-speed random access memory, and can also include a non-transitory memory such as at least one magnetic disk storage device, a flash memory device, or other non-transitory solid state memory device. In some alternative embodiments, the memory 20 can optionally include memory that is remotely located with respect to the processor 10, and which can be connected to the computer device through a network. Examples of such networks include, but are not limited to, the Internet, an enterprise intranet, a local area network, a mobile communications network, and combinations thereof.

[0098] The memory 20 can include a volatile memory, such as a random access memory, and / or can include a non-volatile memory, such as at least one magnetic disk storage device, a flash memory device, or other non-volatile solid state memory device. The memory 20 can also include an array of multi-state flash memory cells, which can be used to store data and / or instructions in multiple states.

[0099] The computer device also includes a communications interface 30 for communicating with other devices or communication networks.

[0100] The embodiments of the present application also provide a computer readable storage medium, and the method according to the embodiments of the present application can be implemented in hardware, firmware, or recorded in a storage medium, or implemented as computer code to be originally stored in a remote storage medium or a non-transitory machine readable storage medium downloaded through a network and stored in a local storage medium, so that the method described herein can be processed by such software on a storage medium using a general purpose computer, a special purpose processor, or programmable or special purpose hardware. The storage medium can be a magnetic disk, an optical disk, a read-only memory, a random access memory, a flash memory, a hard disk, or a solid state disk, etc. Further, the storage medium can also include a combination of the above-mentioned types of memory. It can be understood that the computer, processor, microprocessor controller, or programmable hardware includes a storage component that can store or receive software or computer code, which, when accessed and executed by the computer, processor, or hardware, implements the method shown in the above embodiments.

[0101] Part of the present application can be applied as a computer program product, for example, computer program instructions, when executed by a computer, through the operation of the computer, can invoke or provide the method and / or technical solutions according to the present application. Those skilled in the art should understand that the form of computer program instructions in computer readable medium includes but is not limited to source files, executable files, installation package files and the like, and accordingly, the way of computer program instructions executed by computer includes but is not limited to: the computer directly executes the instructions, or the computer compiles the instructions and then executes the corresponding compiled program, or the computer reads and executes the instructions, or the computer reads and installs the instructions and then executes the corresponding installed program. Here, the computer readable medium can be any available computer readable storage medium or communication medium accessible to the computer.

[0102] Although the embodiments of the present application are described in conjunction with the drawings, various modifications and changes can be made by those skilled in the art without departing from the spirit and scope of the present application, and such modifications and changes fall within the scope defined by the present application.

Claims

1. A method for determining critical speed, characterized in that: The method comprises: Analyzing the dynamic characteristics of a target pumped storage unit to determine a dynamic characteristic coefficient of the target pumped storage unit, wherein the dynamic characteristic coefficient includes a dynamic characteristic coefficient of a guide bearing and a dynamic characteristic coefficient of an annular seal; Constructing an unbalanced mass force model, an unbalanced magnetic pull model, and an unbalanced water pressure model of the target pumped storage unit; Constructing a rotor system motion model of the target pumped storage unit based on the dynamic characteristic coefficient, the unbalanced mass force model, the unbalanced magnetic pull model, and the unbalanced water pressure model; Based on the rotor system motion model, respectively determining modal frequencies corresponding to a plurality of rotational speeds; Based on the modal frequencies, a critical speed is determined.

2. The method according to claim 1, characterized in that The analyzing the power characteristics of the target pumped storage unit to determine the power characteristic coefficient of the target pumped storage unit includes: Based on a preset analysis algorithm, the oil film force of the guide bearing of the target pumped storage unit is analyzed to obtain the oil film stiffness coefficient and the oil film damping coefficient, wherein the dynamic characteristic coefficient of the guide bearing includes the oil film stiffness coefficient and the oil film damping coefficient.

3. The method according to claim 1, characterized in that The analyzing the power characteristics of the target pumped storage unit to determine the power characteristic coefficient of the target pumped storage unit includes: Based on the relationship between the sealing force and displacement, velocity and acceleration of the annular seal of the target pumped storage unit, the sealing force components acting on the rotor in the first direction and the second direction are determined to obtain the dynamic characteristic coefficient of the annular seal.

4. The method according to claim 1, wherein Constructing an unbalanced mass force model of the target pumped storage unit includes: Obtaining an unbalanced mass, where the unbalanced mass is obtained based on a rotor dynamic balancing test; Based on the unbalanced mass, the eccentric moment and the initial phase of the rotor, unbalanced mass force components of the rotor in a first direction and a second direction are respectively constructed to obtain the unbalanced mass force model.

5. The method according to claim 1, wherein Constructing an unbalanced magnetic pull model of the target pumped storage unit, including: The unbalanced magnetic pull model is obtained by performing Maxwell stress integration on the generator motor of the target pumped-storage unit.

6. The method according to claim 1, characterized in that Constructing an unbalanced water pressure model of the target pumped storage unit includes: Integrating the water pressure acting on the runner in the first direction to obtain an unbalanced water pressure component in the first direction; The water pressure acting on the runner in the second direction is integrated and calculated to obtain an unbalanced water pressure component in the second direction.

7. The method according to claim 1, characterized in that The step of constructing a rotor system motion model of the target pumped storage unit based on the dynamic characteristic coefficient, the unbalanced mass force model, the unbalanced magnetic pull model, and the unbalanced water pressure model includes: Determining an external force model in the rotor system motion model based on the unbalanced mass force model, the unbalanced magnetic pull model, and the unbalanced water pressure model; The rotor system motion model is constructed based on the dynamic characteristic coefficient and the external force model.

8. A critical speed determination device, characterized in that: The device comprises: a characteristic coefficient determination module, configured to analyze the dynamic characteristics of a target pumped storage unit and determine a dynamic characteristic coefficient of the target pumped storage unit, wherein the dynamic characteristic coefficient includes a dynamic characteristic coefficient of a guide bearing and a dynamic characteristic coefficient of an annular seal; A first model building module is used to build an unbalanced mass force model, an unbalanced magnetic pull model and an unbalanced water pressure model of the target pumped storage unit; a second model building module, configured to build a rotor system motion model of the target pumped-storage unit based on the dynamic characteristic coefficient, the unbalanced mass force model, the unbalanced magnetic pull model, and the unbalanced water pressure model; A modal frequency determination module, configured to determine modal frequencies corresponding to a plurality of rotational speeds based on the rotor system motion model; The critical speed determination module is configured to determine the critical speed based on the modal frequency.

9. A computer device, characterized in that: include: A memory and a processor, wherein the memory and the processor are communicatively connected to each other, the memory stores computer instructions, and the processor executes the critical speed determination method according to any one of claims 1 to 7 by executing the computer instructions.

10. A computer-readable storage medium, characterized in that The computer-readable storage medium stores computer instructions, and the computer instructions are used to enable a computer to execute the critical speed determination method according to any one of claims 1 to 7.

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