A Bearing Load Assessment and Reconstruction Method and System Based on Load Inversion

Abstract

This invention discloses a bearing load assessment and reconstruction method and system based on load inversion. The core process includes: constructing a database of theoretical design values ​​for bearing loads; building a database of true bearing load values ​​for inversion; calculating rotor operating position parameters using a non-contact eddy current displacement sensor; obtaining the true bearing load values ​​through inversion using the rotor operating position parameters; conducting load inversion assessments for the entire shaft system and individual bearings; and triggering load anomaly warnings. This invention achieves accurate acquisition of true bearing load values ​​by inverting measured rotor operating position parameters, reconstructing an assessment system of "inversion true value - theoretical design value." Based on the inversion-driven assessment logic, it can proactively determine whether the loads of individual bearings and the overall shaft system are abnormal, providing precise guidance for the operation, maintenance, and management of turbine unit bearings. This invention effectively improves the reliability of bearing load assessment, reduces the risk of excessive vibration and instability in the unit, and significantly improves the safety margin of bearing load operation, possessing high practical and promotional value.

Description

Technical Field

[0001] This invention relates to the field of turbine shaft load distribution calculation technology, and in particular to a bearing load assessment and reconstruction method and system based on load inversion. Background Technology

[0002] The accuracy of bearing load assessment directly determines whether a steam turbine unit can achieve long-term safe, stable, and economical operation. It is also an important factor affecting the unit's overhaul cycle and operation and maintenance costs.

[0003] In the current design phase, the theoretical design values ​​of the loads of individual bearings and shaft systems can be obtained through forward calculation: using rotor geometry, material density, and rated operating conditions as input parameters, a static model or a simplified dynamic model is established, and the force and moment balance equations are solved according to preset external loads and constraints to obtain the theoretical design values ​​of the loads for each bearing. However, during the actual operation of the turbine unit, due to uncontrollable factors such as statically indeterminate vibrations in the shaft system, nonlinear characteristics of the oil film that are difficult to model, temperature-affected changes in the bearing's hot elevation, steam pressure fluctuations caused by load changes, and boundary conditions that do not match the actual operating conditions, there is often a large deviation between the theoretical design values ​​of the loads obtained through forward calculation and the actual loads on the bearings. This can easily lead to overload, excessive wear and temperature rise, or light load problems in some bearing bushes, resulting in oil film oscillation, excessive metal temperature, or even bearing failure.

[0004] Therefore, it is urgent to introduce a bearing load verification and evaluation mechanism based on inversion: synchronously monitor radial clearance data related to the rotor's working position during unit operation under load, and directly incorporate uncontrollable dynamic factors that were not considered or fully quantified in the forward-obtained theoretical design value of bearing load through the logic of inversion calculation. These factors include blade aerodynamic lateral force and additional radial load caused by steam radial force that changes with load, nonlinear characteristics of oil film stiffness, and factors such as thermal expansion / deformation of various metal components of the turbine unit during hot operation. The true value of bearing load obtained by inversion is compared with the forward theoretical design value and corrected in a timely manner to reduce load evaluation error and achieve early warning of anomalies. Summary of the Invention

[0005] This invention aims to provide a bearing load assessment and reconstruction method and system based on load inversion. This method can directly encompass complex actual operating conditions that are difficult to accurately model, effectively improving the reliability of bearing load assessment, reducing the risk of unit over-vibration and instability, and significantly increasing the safety margin of bearing load operation. It has high practical and promotional value.

[0006] To achieve the above objectives, this invention discloses a load assessment system for sliding bearings of steam turbine units based on inversion. This system is supported by a true bearing load benchmark database and a signal processing unit. Through a core load inversion module, a coordinated bidirectional assessment module, and an early warning response module, it realizes the inversion of the true bearing load value and the function of early warning of load assessment anomalies. The specific process of the load inversion reconstruction assessment method includes the following steps:

[0007] Step (1): Obtain the geometric parameters, material property parameters and rated working condition parameters of the shaft system, establish the static model of the shaft system, solve for the theoretical design value of the load of the target bearing and build a database of theoretical design values ​​of bearing load;

[0008] Step (2): For the target sliding bearing, the rotor is calculated at different eccentricities through fluid dynamics simulation. , offset angle The load vector of the bearing in the X, Y, and Z directions when it is in the working position ,Establish A multidimensional mapping table is used to build a benchmark database of bearing load true values ​​for inversion after data preprocessing, providing a data retrieval basis for subsequent inversion to obtain load true values;

[0009] Step (3): Under unit operating conditions, the radial clearance change between the rotor and the bearing is measured using two non-contact eddy current displacement sensors, and the rotor's working position parameter, i.e., eccentricity, is obtained based on the minute radial clearance change. , offset angle ;

[0010] Step (4): The eccentricity obtained in step (3) and offset angle To retrieve parameters, the inverse distance weighted interpolation method is used to search for the load vector data that best matches the measured operating conditions in the bearing load truth reference database used for inversion, thereby obtaining the bearing load vectors in the X, Y, and Z directions. ;

[0011] Step (5): Based on the load theoretical design value of Step (1), the load vectors of the bearing in the X, Y, and Z directions are obtained by inverting Step (4) from both the perspectives of a single bearing and the entire shaft system. By conducting a two-way evaluation in both numerical and directional aspects, individual abnormal bearings can be predicted and the overall load distribution of the shaft system can be judged as reasonable.

[0012] Step (6) When the relative magnitude of the inverted load true value and the load theoretical design value of a single bearing deviates by more than ±10% in terms of numerical value or by more than ±8° in terms of directional deviation, mark the single abnormal bearing and trigger an abnormal warning; when the overall load value of the unit shaft system deviates too much, the local load distribution is too concentrated, or the load direction coordination is disordered, resulting in additional torque, trigger an abnormal warning for the shaft system load.

[0013] Further, in step (3), both non-contact eddy current displacement sensors are arranged on the end face of the bearing housing, and at a 90° angle along the circumference of the end face of the bearing housing: the X non-contact eddy current displacement sensor is arranged at a 45° counterclockwise angle to the positive right direction of the X-axis, and is used to measure the radial clearance change in the direction at a 45° counterclockwise angle to the positive right direction of the X-axis; the Y non-contact eddy current displacement sensor is arranged at a 135° counterclockwise angle to the positive right direction of the X-axis, and is used to measure the radial clearance change in the direction at a 135° counterclockwise angle to the positive right direction of the X-axis; both sensors are used to monitor the radial clearance change between the outer surface of the rotor and the inner surface of the bearing bush, and the direction of the outer surface of the rotor approaching the inner surface of the bearing bush is taken as the positive direction. When the outer surface of the rotor approaches the inner surface of the bearing bush, the displacement signal output is... A positive value represents the displacement signal output when the outer surface of the rotor moves away from the inner surface of the bearing bush. It is a negative value.

[0014] Furthermore, step 4 involves the following steps to process the inverted bearing load vectors in the X, Y, and Z directions. Inverse distance weighted interpolation solution:

[0015] Step 41: Establish through simulation calculations Multidimensional mapping table ,in It is the number of known data points. Indicates the first Each data point corresponds to the rotor eccentricity under known operating conditions. , offset angle The rotor working position is The load vector of the bearing in the X, Y, and Z directions ;

[0016] ;

[0017] Step 42: Determine the rotor's eccentricity and offset angle under the target operating condition. The load vectors of the bearing to be inverted in the X, Y, and Z directions ;

[0018] Step 43: Using the Euclidean distance calculation formula Calculate the rotor's eccentricity and offset angle under the target operating condition. To the Rotor eccentricity and offset angle at known data points The two-dimensional Euclidean distance;

[0019] Specifically: when ,Right now and At that time, directly take the data point. The load vectors of the bearing in the X, Y, and Z directions under the target working condition obtained through inversion. The interpolation ends at this point.

[0020] Step 44: According to the formula Calculate the unnormalized weight for each data point ,in This represents a positive exponent, with a default value of 2, which can be modified according to actual needs. Then, according to the normalization formula... Solve for the normalized weights of each data point Multidimensional mapping table Normalized weights for each data point Satisfy normalization constraints: ;

[0021] Step 45: Normalize the weights for each data point and load vector By performing a weighted summation, the operating position of the rotor under the target operating condition can be obtained through inversion. The load vector of the bearing in the X, Y, and Z directions The weighted summation formula is: ; ; .

[0022] Furthermore, the two-way evaluation system for load inversion in step (5) includes: two-way evaluation of the load inversion of a single bearing: the relative magnitude deviation threshold between the true value of the inverted load and the corresponding theoretical design value of the load is ±10%; the threshold for the directional deviation angle is ±8°; two-way evaluation of the rationality of the overall inverted load distribution of the shaft system: calculate the total theoretical load of the shaft system in the theoretical design value database, compare it with the true value of the total load of the shaft system obtained by inversion, analyze whether the true value of the inverted load of the shaft system is uniform in numerical distribution, whether the radial force and axial force of the inverted load of each bearing in the shaft system are coordinated with the theoretical design direction, and comprehensively evaluate whether there is a risk of shaft system vibration due to directional disorder.

[0023] An inversion-based load assessment system for sliding bearings in steam turbine units, comprising:

[0024] a) Load theoretical design value database, used to store the load theoretical design values ​​of individual bearings and shaft systems obtained through forward simulation calculations using the shaft static model;

[0025] b) The bearing load truth benchmark database used for inversion, which stores the rotor under known operating positions established by fluid dynamics simulation for the target type of sliding bearing. Multidimensional mapping table;

[0026] c) A signal processing unit, connected to two non-contact eddy current displacement sensors, is used to acquire parameters related to the radial clearance change between the rotor and the bearing, and to calculate the rotor's eccentricity in real time under the target operating condition. and offset angle This provides core input parameters for obtaining the true value of bearing inversion load. ;

[0027] d) Load inversion module, which communicates with the bearing load truth reference database and signal processing unit used for inversion, to obtain the rotor eccentricity and offset angle under the target operating condition. As input, it completes the accurate inversion of the true value of the bearing load;

[0028] e) A two-way evaluation module is used to compare the true load value obtained through inversion with the pre-stored theoretical load value to complete the two-way deviation evaluation of the load vector in terms of both value and direction, from the perspective of a single bearing and from the perspective of the entire shaft system.

[0029] f) The early warning response module, relying on the evaluation logic driven by inversion, identifies abnormal load distribution of individual bearings and the entire shaft system. In the bidirectional evaluation module, when the relative magnitude difference of the load vector in terms of numerical value and the deflection angle of the load vector in terms of direction exceed the set threshold, a graded early warning signal is output.

[0030] 5. A load evaluation system for turbine sliding bearings based on inversion according to claim 4, characterized in that: the bearing load truth reference database used for inversion is stored in the non-volatile storage area of ​​the turbine digital control system, and the load inversion module, bidirectional evaluation module and early warning response module are embedded in the turbine TSI or TDM system.

[0031] This invention realizes a two-way evaluation system for load inversion, focusing on two levels: the load of a single bearing and the overall load of the shaft system. Using the theoretical load values ​​from the load theory design value database as a benchmark, the load vectors of the bearing in the X, Y, and Z directions are obtained through inversion in a spatial coordinate system. A two-way evaluation is performed, both numerically and directionally. The two-way evaluation of the inverted load for a single bearing involves comparing the true value of the inverted load of a single target sliding bearing with the corresponding theoretical design value in both magnitude and direction. The relative numerical deviation and directional deflection relative to the coordinate axes are calculated to determine if the relative numerical deviation and directional deflection exceed the design threshold, and the bearing with abnormal load is identified. An early warning is triggered when the numerical deviation between the true inverted load of the overall shaft system and the corresponding theoretical design value is too large, the load distribution in the shaft system is too concentrated locally, or the load direction is disrupted, resulting in additional torque. This indicates a risk of over-vibration or instability in the shaft system.

[0032] The beneficial effects of this invention are:

[0033] 1. High accuracy of bearing load assessment after inversion and reconstruction: A true value database of bearing loads used for inversion is constructed, and non-contact eddy current displacement sensors are used to monitor the relevant state parameters of the rotor working position, so as to achieve accurate inversion of the true value of the load of a single bearing and the entire shaft system. This effectively avoids the shortcomings of existing calculation methods for obtaining theoretical design values ​​of loads, which fail to fully consider the uncontrollable dynamic influence factors that occur in the operating conditions. This makes the load assessment of a single bearing and the entire shaft system more consistent with the actual operating conditions.

[0034] 2. The bearing load assessment system after inversion and reconstruction is scientific and reliable: The constructed load theoretical design value database and the bearing load true value benchmark database used for inversion serve as the data foundation, realizing bidirectional assessment of the load vector in terms of both numerical value and direction at both the individual bearing and the shaft system as a whole. It comprehensively covers the distribution of loads on local metal parts and the shaft system as a whole, effectively improving the comprehensiveness and reliability of the load assessment results.

[0035] 3. The bearing load assessment system after inversion and reconstruction has strong predictive ability for load anomalies: Based on the assessment logic driven by inversion, it makes a judgment on whether the load of a single bearing and the overall shaft system is abnormal, providing accurate guidance for the operation, maintenance and management of turbine unit bearings, effectively improving the reliability of bearing load assessment, reducing the risk of unit over-vibration and instability, and significantly improving the safety margin of bearing load fluctuations during unit operation, which has high practical value. Attached Figure Description

[0036] Figure 1 This is a schematic diagram illustrating the technical path of the bearing load assessment and reconstruction method and system presented in this paper.

[0037] Figure 2 This is the flowchart of the system.

[0038] Figure 3 This is a schematic diagram of the turbine shaft system as an example of this method. Detailed Implementation

[0039] The present invention will be further illustrated below with reference to the accompanying drawings and specific embodiments. It should be understood that the following specific embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. It should be noted that the terms "front," "rear," "left," "right," "up," and "down" used in the following description refer to directions in the accompanying drawings, and the terms "inner" and "outer" refer to directions toward or away from the geometric center of a specific component, respectively.

[0040] Taking a 350MW steam turbine generator unit of a thermal power plant as the evaluation object, the unit has a high-pressure and intermediate-pressure combined cylinder, a low-pressure cylinder, and three rotors for the generator. The shaft system is equipped with six floor-mounted radial bearings, and the exciter rotor is installed on the extended end of the generator rotor (e.g., Figure 3 (As shown in Table 1). The total weight of the shaft system, including the rotor, coupling, bearing inner ring, and auxiliary transmission components, is approximately 164,875 kg. The weights of each component are shown in Table 1. Based on the inversion-based load assessment system for turbine unit sliding bearings described in this invention, the bearing load inversion assessment for individual bearings and the entire shaft system is carried out. The specific implementation process is as follows:

[0041] Table 1: Mass of Unit Components

[0042] I. Calculation of Theoretical Design Values ​​of Bearing Load

[0043] A discretized modeling method for the rotor shaft system of a steam turbine generator set was adopted to ensure that the total weight, total length, and center of mass of the simplified model corresponded to the actual rotor. The mass of each component after modeling is shown in Table 2. A set of force and torque balance equations was established, and the overall shaft system load was reasonably distributed into individual bearing theoretical loads based on the stiffness and installation position of each bearing, as shown in Table 3.

[0044] Table 2: Mass of each component of the unit after modeling

[0045]

[0046] Table 3: Theoretical Design Values ​​of Load for Each Bearing

[0047] II. Establishing a True Value Database for Bearing Loads Used in the Inversion

[0048] The geometric parameters of each target bearing in the simulation calculation are set as shown in Table 4. All bearings adopt a single-sided oil inlet method. The geometric center of the oil inlet is located on the horizontal left side of the bearing, and the opening direction of the oil inlet is perpendicular to the end face of the bearing housing.

[0049] Table 4: Modeling parameters of a single bearing

[0050] For the above-mentioned target type of sliding bearing, fluid dynamics simulation tools were used to simulate and calculate the rotor at different eccentricities. and offset angle The load vectors of the bearing in the X, Y, and Z spatial directions under the corresponding working position and operating conditions. ,Establish A multidimensional mapping table is constructed to form a true value benchmark database for bearing loads used in the inversion, serving as a data benchmark for subsequent comparison and evaluation between theoretical load design values ​​and true load values.

[0051] III. Real-time monitoring and calculation of rotor working position

[0052] The clearance data between the rotor and the bearing bush were measured and the eccentric coordinates of the rotor center were calculated: A Cartesian coordinate system O-XY was established on the plane containing the radial section of the bearing bush, with the center of the bearing bush's inner hole as the origin O, the horizontal direction to the right as the positive X-axis, and the vertical direction upward as the positive Y-axis. Figure 1 (As shown in the figure). The inner diameter of the bearing bush is defined as R, and the rotor radius is r. In the initial state, the rotor center coincides with the inner diameter O of the bearing bush. At this time, the initial radial clearance between the inner surface of the bearing bush and the outer surface of the rotor is Rr.

[0053] Two non-contact eddy current displacement sensors are both arranged on the end face of the bearing housing, at a 90° angle along the circumference: The X-type non-contact eddy current displacement sensor is arranged at a 45° counterclockwise angle to the positive X-axis of the Cartesian coordinate system, used to measure radial clearance changes in the direction 45° counterclockwise from the positive X-axis; the Y-type non-contact eddy current displacement sensor is arranged at a 135° counterclockwise angle to the positive X-axis of the Cartesian coordinate system, used to measure radial clearance changes in the direction 135° counterclockwise from the positive X-axis. The direction from the rotor's outer surface to the inner surface of the bearing bush is taken as the positive direction; a positive displacement signal is output when the rotor's outer surface approaches the inner surface of the bearing bush. When the outer surface of the rotor moves away from the inner surface of the bearing bush, the output displacement signal is negative. (like Figure 1 (As shown). Through the formula , Calculate the eccentric coordinates of the rotor center Further calculations yielded the rotor eccentricity under the target operating condition. , offset angle .

[0054] IV. Obtaining the True Value of Bearing Load through Inversion

[0055] Taking bearing No. 5 as an example: the measured displacement signal output , Calculated according to the formula , , , ;by Using the input parameters, the load vectors of bearing No. 5 in the X, Y, and Z directions, obtained by inverse distance weighted interpolation from the bearing load truth reference database used for inversion, are as follows: , , The radial load value is 406148.21 N, and the radial load direction deviation angle is -1.95° (i.e., a counterclockwise angle of 1.95° with the positive Y-axis in the O-XY coordinate system). Repeating the above steps yields the true values ​​of the inverse loads for the remaining five bearings. The rotor eccentricity and deviation angle under the target operating condition are monitored and calculated. The true load values ​​of a single target bearing obtained by inversion are shown in Table 5.

[0056] Table 5: Inversion Results of Actual Load for Each Bearing

[0057]

[0058] V. Two-way evaluation of bearing load

[0059] Focusing on both individual bearing loads and overall shaft system loads, and using theoretical load values ​​from the load theory design database as a benchmark, the load vectors of the bearings in the X, Y, and Z directions are inverted in a spatial coordinate system. A two-way evaluation was performed, both numerically and directionally. The load evaluation results are shown in Table 6.

[0060] Table 6: Comparison of True Values ​​of Load Inversion with Theoretical Design Values ​​of Load for Individual Bearings

[0061] (1) Two-way evaluation of inverted load of a single bearing: The threshold for the relative magnitude difference of the load vector in terms of numerical value is set to ±10%; the threshold for the directional deviation of the load vector is set to ±8°. According to the data in Table 6, the absolute value of the relative magnitude deviation of the load of bearings 1, 2 and 4 in terms of numerical value is ≥10%, and the directional deviation of the load of bearings 1 and 2 is >8°. Therefore, bearings 1, 2 and 4 are marked as “abnormal”; the absolute value of the relative magnitude deviation of the load of bearing 3 in terms of numerical value is close to 10% but does not exceed it, and the directional deviation of the load is <8°. Therefore, bearing 3 is marked as “attention”; the relative magnitude deviation of the load of bearings 5 ​​and 6 in terms of numerical value and the directional deviation are both less than the threshold. Therefore, bearings 5 ​​and 6 are marked as “normal”.

[0062] (2) Two-way evaluation of the rationality of the load distribution inversion of the unit shaft system: The theoretical design value of the total load of the shaft system is The true value of the total load in the inversion is The relative deviation of the total load in terms of value is <0.1%, which meets the application requirements. The uniformity of the overall load distribution in the unit's shaft system is judged as "poor distribution" because the relative magnitude deviation between the actual load and the theoretical load of bearings 1, 2, and 4 is too large. The directional coordination of the overall load distribution in the unit's shaft system is judged as follows: the directional deviation angle of the actual load of bearings 1 and 2 is >8°, indicating a risk of vibration induced by additional torque, requiring a design safety margin.

[0063] VI. Load assessment triggers load anomaly early warning response

[0064] Based on the bidirectional evaluation results of load inversion, the following warnings are triggered: Level 1 Warning (Low Risk): The evaluation results of bearings 1 and 2 show abnormal load value deviation and directional deviation exceeding the threshold. The abnormal individual bearing is marked, and the bearing elevation and wear condition are checked on-site. Level 2 Warning (Medium Risk): The overall load of the shaft system is disordered in direction, indicating the risk of additional bending moment. Level 3 Warning (High Risk): The relative deviation between the theoretical design value of the total load of the shaft system and the true value of the total inverted load is <10%, which meets the application requirements and no alarm is triggered.

[0065] After the graded early warning signal is output, the basic data of the bearing load theoretical design value database and the bearing load true value benchmark database used for inversion are combined to carry out targeted inspection and correction of individual abnormal bearings: (1) Check the wear condition of bearings No. 1, 2 and 4, and readjust the shim elevation to eliminate load vector deviation; (2) Re-measure the hot state of the low pressure cylinder, and adjust the simulation model parameters in combination with the basic data of the bearing load true value benchmark database used for inversion to improve the matching degree between the bearing inversion load bidirectional evaluation results and the actual working conditions.

[0066] The technical means disclosed in this invention are not limited to those disclosed in the above embodiments, but also include technical solutions composed of any combination of the above technical features.

Claims

1. A method for reconstructing a bearing load assessment system based on load inversion, characterized in that, Includes the following steps: Step (1): Obtain the geometric parameters, material property parameters and rated working condition parameters of the shaft system, establish the static model of the shaft system, solve for the theoretical design value of the load of the target bearing and build a database of theoretical design values ​​of bearing load; Step (2): For the target sliding bearing, the rotor is calculated at different eccentricities through fluid dynamics simulation. , offset angle The load vector of the bearing in the X, Y, and Z directions when it is in the working position ,Establish A multidimensional mapping table is used to build a benchmark database of bearing load true values ​​for inversion after data preprocessing, providing a data retrieval basis for subsequent inversion to obtain load true values; Step (3): Under unit operating conditions, the radial clearance change between the rotor and the bearing is measured using two non-contact eddy current displacement sensors, and the rotor's working position parameter, i.e., eccentricity, is obtained based on the minute radial clearance change. , offset angle ; Step 4: The eccentricity obtained in step (3) and offset angle To retrieve parameters, the inverse distance weighted interpolation method is used to search for the load vector data that best matches the measured operating conditions in the bearing load truth reference database used for inversion, thereby obtaining the bearing load vectors in the X, Y, and Z directions. ; Step (5): Based on the load theoretical design value of Step (1), the load vectors of the bearing in the X, Y, and Z directions are obtained by inverting Step (4) from both the perspectives of a single bearing and the entire shaft system. By conducting a two-way evaluation in both numerical and directional aspects, individual abnormal bearings can be predicted and the overall load distribution of the shaft system can be judged as reasonable. Step (6) When the relative magnitude of the inverted load true value and the load theoretical design value of a single bearing deviates by more than ±10% in terms of numerical value or by more than ±8° in terms of directional deviation, mark the single abnormal bearing and trigger an abnormal warning; when the overall load value of the unit shaft system deviates too much, the local load distribution is too concentrated, or the load direction coordination is disordered, resulting in additional torque, trigger an abnormal warning for the shaft system load.

2. The bearing load assessment system reconstruction method based on load inversion according to claim 1, characterized in that: Step (3) Both non-contact eddy current displacement sensors are arranged on the end face of the bearing housing, at a 90° angle along the circumference: the X non-contact eddy current displacement sensor is arranged at a 45° counterclockwise angle to the positive right direction of the X-axis, and is used to measure the radial clearance change in the direction at a 45° counterclockwise angle to the positive right direction of the X-axis; the Y non-contact eddy current displacement sensor is arranged at a 135° counterclockwise angle to the positive right direction of the X-axis, and is used to measure the radial clearance change in the direction at a 135° counterclockwise angle to the positive right direction of the X-axis; both sensors are used to monitor the radial clearance change between the outer surface of the rotor and the inner surface of the bearing bush, and the direction of the outer surface of the rotor approaching the inner surface of the bearing bush is taken as the positive direction. The displacement signal output when the outer surface of the rotor approaches the inner surface of the bearing bush is... A positive value represents the displacement signal output when the outer surface of the rotor moves away from the inner surface of the bearing bush. It is a negative value.

3. The bearing load assessment system reconstruction method based on load inversion according to claim 1, characterized in that: Step 4 involves the following steps to process the inverted bearing load vectors in the X, Y, and Z directions. Inverse distance weighted interpolation solution: Step 41: Establish through simulation calculations Multidimensional mapping table ,in It is the number of known data points. Indicates the first Each data point corresponds to the rotor eccentricity under known operating conditions. , offset angle The rotor working position is The load vector of the bearing in the X, Y, and Z directions , ; ； Step 42: Determine the rotor's eccentricity and offset angle under the target operating condition. The load vectors of the bearing to be inverted in the X, Y, and Z directions ; Step 43: Using the Euclidean distance calculation formula Calculate the rotor's eccentricity and offset angle under the target operating condition. To the Rotor eccentricity and offset angle at known data points The two-dimensional Euclidean distance; Specifically: when ,Right now and At that time, directly take the data point. The load vectors of the bearing in the X, Y, and Z directions under the target working condition obtained through inversion. The interpolation ends at this point. Step 44: According to the formula Calculate the unnormalized weight for each data point ,in This represents a positive exponent, with a default value of 2, which can be modified according to actual needs. Then, according to the normalization formula... Solve for the normalized weights of each data point Multidimensional mapping table Normalized weights for each data point Satisfy normalization constraints: ; Step 45: Normalize the weights for each data point and load vector By performing a weighted summation, the operating position of the rotor under the target operating condition can be obtained through inversion. The load vector of the bearing in the X, Y, and Z directions The weighted summation formula is: ; ; .

4. The bearing load assessment system reconstruction method based on load inversion according to claim 1, characterized in that: The two-way evaluation system for load inversion in step (5) includes: two-way evaluation of the load inversion of a single bearing: the relative magnitude deviation threshold between the true value of the inverted load and the corresponding theoretical design value of the load is ±10%; the threshold for the directional deviation angle is ±8°; two-way evaluation of the rationality of the overall load distribution of the shaft system: calculate the total theoretical load of the shaft system in the load theoretical design value database, compare it with the true value of the total load of the shaft system obtained by inversion, analyze whether the true value of the inverted load of the shaft system is uniform in numerical distribution, whether the radial force and axial force of the inverted load of each bearing in the shaft system are coordinated with the theoretical design direction, and comprehensively evaluate whether there is a risk of shaft system vibration due to directional disorder.

5. A load assessment system for turbine sliding bearings based on inversion according to any one of claims 1-4, characterized in that, include: a) Load theoretical design value database, used to store the load theoretical design values ​​of individual bearings and shaft systems obtained through forward simulation calculations using the shaft static model; b) The bearing load truth benchmark database used for inversion, which stores the rotor under known operating positions established by fluid dynamics simulation for the target type of sliding bearing. Multidimensional mapping table; c) A signal processing unit, connected to two non-contact eddy current displacement sensors, is used to acquire parameters related to the radial clearance change between the rotor and the bearing, and to calculate the rotor's eccentricity in real time under the target operating condition. and offset angle This provides core input parameters for obtaining the true value of bearing inversion load. ; d) Load inversion module, which communicates with the bearing load truth reference database and signal processing unit used for inversion, to obtain the rotor eccentricity and offset angle under the target operating condition. As input, it completes the accurate inversion of the true value of the bearing load; e) A two-way evaluation module is used to compare the true load value obtained through inversion with the pre-stored theoretical load value to complete the two-way deviation evaluation of the load vector in terms of both value and direction, from the perspective of a single bearing and from the perspective of the entire shaft system. f) The early warning response module, relying on the evaluation logic driven by inversion, identifies abnormal load distribution of individual bearings and the entire shaft system. In the bidirectional evaluation module, when the relative magnitude difference of the load vector in terms of numerical value and the deflection angle of the load vector in terms of direction exceed the set threshold, a graded early warning signal is output.

6. The inversion-based load assessment system for turbine unit sliding bearings according to claim 5, characterized in that: The bearing load true value reference database used for inversion is stored in the non-volatile storage area of ​​the turbine digital control system. The load inversion module, bidirectional evaluation module and early warning response module are embedded in the turbine TSI or TDM system.

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