A gas turbine cylinder displacement monitoring system and method

Abstract

The present application relates to the technical fields of gas turbine equipment operation and maintenance, in particular to a gas turbine cylinder displacement monitoring system and method, the present application acquires the expansion displacement of multiple positions of the gas turbine cylinder through the displacement sensor, then determines the reference expansion displacement range through the acquisition of the gas turbine operation load and surface temperature, so as to determine whether the expansion displacement under the current operation load and surface temperature is abnormal. The image of the elastic support plate bending process is analyzed, and the bending characteristics of the elastic support plate in the stress process are extracted. Through the analysis of the bending symmetry characteristics, it can be judged whether the bending of the elastic support plate on both sides is symmetrical, and combined with the reference expansion displacement range, the comprehensive expansion displacement and the bending uniformity characteristics of the elastic support plate, it can be judged whether the elastic support plate hinders the expansion of the cylinder and whether it produces defects such as stiffness improvement in the high temperature environment.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of gas turbine equipment operation and maintenance, and particularly relates to a gas turbine cylinder displacement monitoring system and method. BACKGROUND

[0002] Figure 1 A schematic diagram of an existing gas turbine installation structure is shown in FIG. 1. Figure 1 As shown in FIG. 1, when the gas turbine is working, the highest temperature inside the combustion chamber reaches 1400 DEG C, and the turbine blade and cylinder temperature also reaches 500-600 DEG C. Due to the thermal expansion characteristics of metal, when the gas turbine is working, the cylinder will be displaced in the axial direction to the exhaust direction. In order to ensure the free expansion and contraction of the gas turbine unit in the working state, the gas turbine is provided with a special elastic support to ensure that the displacement of the gas turbine cylinder is not limited.

[0003] However, when the gas turbine is not installed in a standard manner, is not properly maintained, or is incorrectly operated, the support may fail, which not only cannot guarantee the free expansion displacement of the gas turbine cylinder, but also hinders the expansion of the gas turbine cylinder.

[0004] At present, there is no monitoring means for the expansion of the cylinder of the gas turbine, and the displacement value is not analyzed, and the equipment degradation prediction can only be carried out after the defect maintenance. SUMMARY

[0005] Therefore, the present application aims to provide a gas turbine cylinder displacement monitoring system and method to solve the above technical problems.

[0006] In order to achieve the above-mentioned purpose, the present application adopts the following technical solutions:

[0007] The gas turbine cylinder displacement monitoring system of the present application comprises the following steps:

[0008] A data acquisition module is configured to acquire the current operating load of the gas turbine, the surface temperature of the gas turbine cylinder, an inclined image containing an elastic support plate, and the expansion displacement amount of a plurality of measurement positions of the hot end of the gas turbine cylinder, wherein the elastic support plate is bent when the hot end of the gas turbine cylinder expands, and the expansion displacement amount of the plurality of measurement positions is acquired by a plurality of range finders.

[0009] A reference data module is configured to extract the reference expansion displacement range of the hot end of the gas turbine cylinder corresponding to the current operating load and the surface temperature from a pre-constructed reference database.

[0010] An image processing module is configured to process the inclined image to obtain the deformation characteristics of the elastic support plate, wherein the deformation characteristics include the bending uniformity characteristics and the bending symmetry characteristics.

[0011] The analysis module is configured to calculate a comprehensive expansion displacement of the expansion displacement amounts of the plurality of measurement positions, check the bending features on both sides of the elastic support plate based on the bending symmetry feature of the elastic support plate to obtain a symmetry checking result of the elastic support plate, and check the comprehensive expansion displacement and the bending uniformity feature based on the reference expansion displacement range to obtain an elasticity checking result of the elastic support plate.

[0012] The monitoring and early warning module is configured to monitor and early warn the displacement of the gas turbine cylinder based on the symmetry checking result and the elasticity checking result of the elastic support plate.

[0013] The application further provides a gas turbine cylinder displacement monitoring method, which comprises the following steps.

[0014] The current operation load of the gas turbine, the surface temperature of the gas turbine cylinder, an inclined image containing an elastic support plate, and expansion displacement amounts of a plurality of measurement positions of the hot end of the gas turbine cylinder are acquired, wherein the elastic support plate bends when the hot end of the gas turbine cylinder expands, and the expansion displacement amounts of the plurality of measurement positions are collected by a plurality of range finders.

[0015] A reference expansion displacement range of the hot end of the gas turbine cylinder corresponding to the current operation load and the surface temperature is extracted from a pre-constructed reference database.

[0016] The inclined image is processed to obtain deformation features of the elastic support plate, wherein the deformation features include a bending uniformity feature and a bending symmetry feature.

[0017] The analysis module is configured to calculate a comprehensive expansion displacement of the expansion displacement amounts of the plurality of measurement positions, check the bending features on both sides of the elastic support plate based on the bending symmetry feature of the elastic support plate to obtain a symmetry checking result of the elastic support plate, and check the comprehensive expansion displacement and the bending uniformity feature based on the reference expansion displacement range to obtain an elasticity checking result of the elastic support plate.

[0018] The monitoring and early warning module is configured to monitor and early warn the displacement of the gas turbine cylinder based on the symmetry checking result and the elasticity checking result of the elastic support plate.

[0019] The beneficial effects of the present application are: the gas turbine cylinder displacement monitoring system and method provided by the present application can collect the expansion displacement amounts of multiple positions of the gas turbine cylinder through the displacement sensor, and then determine the reference expansion displacement range by collecting the running load and surface temperature of the gas turbine, so as to determine whether the expansion displacement amount under the current running load and surface temperature is abnormal. The image of the bending process of the elastic support plate under stress is analyzed, and the bending characteristics of the elastic support plate during the stress process are extracted. By analyzing the bending symmetry characteristics, it can be determined whether the bending of the elastic support plate on both sides is symmetrical, and in combination with the reference expansion displacement range, the comprehensive expansion displacement amount and the bending uniformity characteristics of the elastic support plate, it can be determined whether the elastic support plate hinders the expansion of the cylinder and whether it has defects such as stiffness improvement in the high temperature environment. The present application can effectively monitor whether the support structure has defects in real time by monitoring the displacement of the gas turbine cylinder, and solves the problem that the equipment can only be found and maintained after serious deterioration. BRIEF DESCRIPTION OF DRAWINGS

[0020] The present application will be further described below in combination with the drawings and embodiments:

[0021] Figure 1 It is a schematic diagram of the installation structure of the existing gas turbine;

[0022] Figure 2 It is a use scene diagram of a gas turbine cylinder displacement monitoring system in an embodiment of the present application;

[0023] Figure 3 It is a structure schematic diagram of the data processing part of a gas turbine cylinder displacement monitoring system shown in an embodiment of the present application;

[0024] Figure 4 It is a structure diagram of a gas turbine cylinder displacement monitoring system shown in an embodiment of the present application;

[0025] Figure 5 It is an example diagram of the outer contour of the elastic support plate in an embodiment of the present application;

[0026] Figure 6 It is a schematic diagram of the included angle in an embodiment of the present application;

[0027] Figure 7 It is a flowchart of the acquisition of the comprehensive expansion displacement amount in an embodiment of the present application;

[0028] Figure 8 It is a flowchart of a gas turbine cylinder displacement monitoring method shown in an embodiment of the present application. DETAILED DESCRIPTION

[0029] Figure 2This is a diagram illustrating an application scenario of a gas turbine cylinder displacement monitoring system according to one embodiment of this application. Figure 2 As shown, this application includes a gas turbine cylinder 1, a U-shaped bracket 2, an elastic support plate 3, a base 4, an LVDT sensor 5, a transmission rod 6, and a transmission rod bracket 7. The U-shaped bracket 2 is connected to both sides of the cylinder 1 via bearings, and the elastic support plate 3 at the bottom of the U-shaped bracket 2 is fixed to the base 4. The base 4 itself is fixed. When the cylinder 1 expands due to heat, it forces the bearings to rotate and bend the elastic support plate 3, thereby allowing the cylinder 1 to expand freely and effectively support it. During this process, the cylinder 1 pushes the transmission rod 6, and the LVDT sensor 5 reads the amount of expansion displacement of the cylinder 1. To prevent the weight of the transmission rod 6 from affecting the reading accuracy, this application also provides a transmission rod bracket 7 on the base 4 to support the transmission rod 6. In addition, a camera 8 is provided to acquire images of the elastic support plate 3.

[0030] Specifically, in this embodiment, the expansion displacement of multiple measurement positions (such as four) at the hot end of the cylinder 1 is collected by LVDT sensors 5. The iron cores of the multiple LVDT sensors 5 are in contact with the hot end of the gas turbine cylinder through the transmission rod 6. The movement direction of the iron cores of the multiple LVDT sensors 5 is consistent with the expansion offset direction of the cylinder 1.

[0031] Figure 3 This is a schematic diagram of the data processing section of a gas turbine cylinder displacement monitoring system according to one embodiment of this application, as shown below. Figure 3 As shown, the analog signals collected by the LVDT sensor are converted into digital signals by the analog-to-digital converter (ADC) and sent to the analysis host. The images captured by the camera are also sent to the analysis host for analysis and monitoring.

[0032] Figure 4 This is a structural diagram of a gas turbine cylinder displacement monitoring system shown in one embodiment of this application, as follows: Figure 4 As shown: This embodiment of a gas turbine cylinder displacement monitoring system includes:

[0033] The data acquisition module 410 is used to acquire the current operating load of the gas turbine, the surface temperature of the gas turbine cylinder, the tilt image including the elastic support plate, and the expansion displacement of multiple measurement positions at the hot end of the gas turbine cylinder. The elastic support plate bends when the hot end of the gas turbine cylinder expands and displaces, and the expansion displacement of the multiple measurement positions is acquired by multiple rangefinders.

[0034] The surface temperature of the gas turbine cylinder block is measured using a temperature gun, while the tilted images are captured by a camera fixed in the location.

[0035] The expansion displacement is acquired by the LVDT sensor mentioned earlier. LVDT stands for Linear Variable Differential Transformer. The main components of an LVDT sensor include a primary coil and two secondary coils. An iron core can move within the air-core coils and is connected to the object being measured. The principle of the LVDT sensor is that when an alternating current passes through the primary coil, a voltage is induced in the secondary coils. The movement of the iron core changes the distribution of the magnetic field, thus affecting the induced voltage in the secondary coils. Through precise circuit design, the LVDT can convert minute displacement changes into measurable voltage changes, thereby achieving high-precision measurement.

[0036] Reference data module 420 is used to extract from a pre-built reference database the reference expansion displacement range of the hot end of the gas turbine cylinder block corresponding to the current operating load and surface temperature;

[0037] Since the cylinder block material is fixed, its thermal expansion ratio is also fixed. Therefore, under normal operating conditions, if the temperature rises to a stable level under a certain operating load (e.g., 80%), its expansion displacement is constant. If the support hinders the free expansion of the cylinder block, prolonged obstruction will cause additional mechanical stress within the cylinder block material. This stress may lead to material fatigue, shortening the service life of the cylinder block and other related components. Furthermore, continuous obstruction may cause permanent deformation or even cracking of the cylinder block or other connected components. This not only affects the normal operation of the gas turbine but may also cause serious equipment failure.

[0038] To investigate whether the support hinders the expansion of the cylinder, this application pre-constructs a reference database. Reference data on the expansion displacement of the cylinder under different operating conditions is obtained through testing, and then the measured expansion displacement is verified. The construction process of the reference database includes:

[0039] (1) Obtain expansion data of the gas turbine at multiple test time points, wherein the expansion data includes operating load value, surface temperature value and expansion displacement;

[0040] Generally, the surface temperature of a gas turbine cylinder block is determined by the operating load of the gas turbine. However, when the load of the gas turbine changes, its temperature change is often lagging. Therefore, in order to find the thermal expansion displacement test value under various scenarios, this application conducts tests under multiple load and temperature conditions and collects expansion displacement data.

[0041] (2) The bloated data is divided into multiple bloated datasets based on the operating load, wherein each bloated dataset contains bloated data within the operating load range;

[0042] (3) The expansion dataset is divided a second time based on the surface temperature value to obtain multiple expansion data subsets, wherein each expansion data subset contains expansion data for a surface temperature range under a running load range;

[0043] In steps (2) and (3), the test data is divided twice to divide the expansion data into multiple load and temperature conditions. The table below is an exemplary division diagram. In practice, the division will be more detailed. The division results are shown in the table below:

[0044] Table 1. Example of data partitioning for dilatation

[0045]

[0046] (4) Remove the expansion data with abnormal expansion displacement in the expansion data subset to obtain the target set; calculate the average value and standard deviation of the expansion displacement of all expansion data in the target set, construct a displacement reference range based on the average value and standard deviation; and construct a reference database based on the displacement parameter range of multiple surface temperature ranges of multiple operating load ranges.

[0047] For any outliers that may appear in the subset (e.g., due to measurement bias, operational errors, etc.), this application calculates the deviation between each expansion displacement and the average value, and removes outliers with deviations exceeding a threshold to obtain the target set. The average value and standard deviation of the target set are calculated, and a reference range is constructed based on three times the standard deviation.

[0048] The reference range is (mean - 3 × standard deviation, mean + 3 × standard deviation).

[0049] Finally, the reference database required in this embodiment can be established based on the reference ranges under various load and temperature conditions.

[0050] Image processing module 430 is used to process the tilted image to obtain the deformation characteristics of the elastic support plate, wherein the deformation characteristics include bending uniformity characteristics and bending symmetry characteristics;

[0051] When the cylinder expands and displaces due to heat, the maximum displacement can reach tens of millimeters, causing significant bending of the elastic support plate (such as a steel plate). Under normal circumstances, the curvature of the bent steel plate is uniform across all locations, and the curvature on both sides is roughly the same. However, during long-term use, the properties of the steel plate may change. For example, its rigidity may increase, making it difficult to bend and thus hindering the cylinder's expansion and displacement; or it may undergo plastic deformation, which cannot be observed visually under the support structure, leading to a risk of hindering the cylinder's expansion and displacement.

[0052] To analyze whether the elastic support plate is functioning properly, this application acquires tilted images of the elastic support plate using a camera (taken at an tilt angle), and then analyzes the curvature of the images to determine the state of the elastic support plate, specifically including:

[0053] (1) The tilted image is preprocessed to obtain a preprocessed image, wherein the preprocessing method includes grayscale processing and high-pass filtering;

[0054] The purpose of preprocessing is to simplify image data and enhance edge information. Grayscale processing converts a color image into a single-channel grayscale image, reducing computational complexity. A commonly used method is the weighted average method. High-frequency components (such as edges and details) are enhanced while low-frequency components (such as smooth background regions) are suppressed to facilitate subsequent contour feature extraction.

[0055] (2) Extract the contour features of the preprocessed image to obtain a contour image; and perform coarse localization on the contour image based on the pre-constructed localization box to obtain the region of interest of the contour image;

[0056] The purpose of step (3) is to locate the approximate area of ​​the elastic support plate. Since the camera position is fixed, a fixed-coordinate bounding box can be used to extract the elastic support plate and the surrounding ROI. Contour extraction utilizes existing contour extraction algorithms, such as the Canny operator.

[0057] (3) Perform morphological processing on the contour features in the region of interest, and after morphological processing, filter out closed contours, and extract the size and rectangularity of each closed contour.

[0058] The purpose of step (3) is to remove noise and extract the effective contour. First, noise is removed through morphological processing, such as opening operations (removing small noise points) or closing operations (filling holes). Then, the area of ​​the closed contour is extracted to obtain the size. At the same time, the minimum bounding rectangle of the closed contour is calculated, and the area of ​​the contour is proportional to the area of ​​the minimum bounding rectangle to obtain the rectangleness.

[0059] (4) The closed contour that meets the preset screening conditions in both size and rectangularity is used as the outer contour of the elastic support plate.

[0060] Because the shape of the elastic support plate is close to a parallelogram or trapezoid when viewed from an oblique angle, its size and rectangularity are stable. Therefore, a closed contour that simultaneously meets the screening criteria of size tolerance range and rectangularity tolerance range is considered as the outer contour of the elastic support plate in this application.

[0061] (5) Extract the two long sides side1 and side2 of the outer contour outline of the elastic support plate, and perform curve fitting on the two long sides side1 and side2 to obtain two target curves curve1 and curve2 on both sides of the elastic support plate.

[0062] The two longer sides, side1 and side2, of the outer contour of the elastic support plate are the two sides that produce bending changes, and can be extracted by their lengths. Using polynomial fitting (such as least squares method) or spline interpolation, uniform sampling can be performed on the fitted curve, which facilitates subsequent analysis.

[0063] Figure 5 This is an example diagram of the outer contour of the elastic support plate in one embodiment of this application. The extracted outer contour of the elastic support plate is shown below. Figure 5 As shown.

[0064] (6) Extract multiple sampling points from the two target curves curve1 and curve2 respectively. i In this case, the curve lengths between adjacent sampling points are the same;

[0065] Specifically, x sampling points are set on the target curves curve1 and curve2 respectively, and the target curves curve1 and curve2 are divided into x+1 curve segments by the sampling points.

[0066] (7) Calculate the tangents of the target curve at multiple sampling points, and calculate the angle θ between the tangents of adjacent sampling points. i_i-1 And the angle θ between the tangents of adjacent sampling points. i_i-1 Based on the curve length S of adjacent sampling points i_i-1 Calculate curve segment i_i-1 curvature ρ i_i-1 , ρ i_i-1 =θ i_i-1 / S i_i-1 ;

[0067] Figure 6 This is a schematic diagram of the included angle in one embodiment of this application. This application constructs the included angle between the current curve segment and the previous curve segment by extracting the tangent, and constructs the curvature of each curve segment by combining the length of the curve segment. Thus, the curvature is used to represent the degree of bending on both sides of the elastic support plate.

[0068] (8) Calculate the average curvature ρ1 and ρ2 of multiple curve segments of two target curves curve1 and curve2 based on the curvature of multiple curve segments, and use the curvature of multiple curve segments of the two target curves curve1 and curve2 as the bending uniformity feature, and use the average curvature of the two target curves curve1 and curve2 as the bending symmetry feature.

[0069] The consistency of the average curvature of target curves curve1 and curve2 reflects whether the degree of bending on both sides of the elastic support plate is consistent (symmetrical). The curvature of multiple curve segments reflects the degree of bending of multiple curve segments. If there is a large difference, it indicates that there may be a change in the rigidity of the segment, which causes the degree of bending of the segment to be different from that of other parts. The increase in rigidity will also create the risk of hindering the expansion displacement of the cylinder.

[0070] Analysis module 440 is used to calculate the comprehensive expansion displacement of the expansion displacement at multiple measurement locations; to verify the bending characteristics on both sides of the elastic support plate based on the bending symmetry characteristics of the elastic support plate, thereby obtaining the symmetry verification result of the elastic support plate; and to verify the comprehensive expansion displacement and the bending uniformity characteristics based on the reference expansion displacement range, thereby obtaining the elasticity verification result of the elastic support plate.

[0071] The expansion displacement values ​​at multiple locations were obtained previously. However, under varying load conditions, uneven temperature distribution may occur, leading to inconsistent expansion displacement values ​​at different locations. Therefore, this application employs the following process to obtain accurate and stable comprehensive expansion displacement values. Figure 7 This is a flowchart illustrating the process of obtaining the comprehensive expansion displacement in one embodiment of this application, as follows: Figure 7 As shown, the process for obtaining the comprehensive expansion displacement includes:

[0072] S1. Calculate the average value of the expansion displacement at the multiple measurement positions, and after normalizing the expansion displacement at the multiple measurement positions, calculate the displacement variance of the multiple normalized expansion displacements.

[0073] First, the overall displacement is obtained by calculating the average value. Then, the variance is calculated to determine whether there is uneven expansion displacement.

[0074] Before calculating the variance, the expansion displacement at multiple measurement locations needs to be normalized to allow for the use of a uniform variance threshold to measure the uniformity of expansion. The normalization method used is max-min normalization, calculated as follows:

[0075]

[0076] In the formula, D is the expansion displacement, D′ is the normalized expansion displacement, max is the maximum value of the expansion displacement at multiple measurement positions, and min is the minimum value of the expansion displacement at multiple measurement positions.

[0077] S2. Compare the displacement variance with the set displacement variance threshold. If the displacement variance is greater than the set displacement variance threshold, it is determined that there is uneven temperature in the cylinder. After waiting for the target time, the expansion displacement of multiple measurement positions is reacquired and the process returns to step S1.

[0078] If the displacement variance exceeds the set displacement variance threshold, it indicates that temperature inhomogeneity is causing slight differences in the expansion displacement at multiple locations. To obtain an accurate overall expansion displacement, it is necessary to wait for the target duration and, after the temperature distribution has become uniform, re-collect the expansion displacement at multiple measurement locations and repeat the above process.

[0079] S3. When the displacement variance is less than or equal to the set displacement variance threshold, the average value of the expansion displacement at the multiple measurement locations is taken as the comprehensive expansion displacement D. average .

[0080] After ensuring uniform temperature distribution and uniform expansion displacement at multiple locations, the average value is taken as the comprehensive expansion displacement D. average .

[0081] After obtaining the above-mentioned comprehensive expansion displacement, reference expansion displacement range, bending uniformity characteristics, and bending symmetry characteristics, the state of the elastic support plate and the U-shaped bracket can be comprehensively analyzed. The analysis logic is as follows:

[0082] (1) Symmetry

[0083] Calculate the difference between the average curvature ρ1 of the target curve curve1 and the average curvature ρ2 of the target curve curve2, |ρ1-ρ2|, and ensure that |ρ1-ρ2| > Δρ. max When the elastic support plate is found to have a defect of asymmetrical bending on both sides, it is determined that the elastic support plate has this defect.

[0084] If the average curvature ρ1 of target curve curve 1 and the average curvature ρ2 of target curve curve 2 differ significantly, it indicates a noticeable difference in the degree of curvature on both sides. This phenomenon may be caused by uneven changes in the rigidity of the elastic support plate on both sides, or by rolling obstruction from a bearing on one side leading to stress variations during expansion displacement, resulting in inconsistent stress on both sides. This application treats this as an asymmetric curvature defect on both sides, and corresponding monitoring and alarm information can be output in subsequent processes.

[0085] (2) Bending uniformity

[0086] (2-1) Calculate the curvature of the multiple curve segments, normalize it, and calculate the variance of the multiple normalized curvatures;

[0087] The normalization calculation also uses the minimum-maximum normalization method; please refer to the previous text for the specific calculation method. The variance of the curvature after multiple normalizations can reflect the uniformity of curvature at multiple locations on a single-sided curve.

[0088] (2-2) Compare the comprehensive expansion displacement with the reference expansion displacement range. When the comprehensive expansion displacement falls into the reference expansion displacement range and the variance is less than or equal to the preset variance threshold, the elastic support plate is determined to be normal.

[0089] If the total expansion displacement falls within the reference expansion displacement range and the bending uniformity is also relatively high, this indicates that the elastic support plate and the U-shaped bracket are under normal stress and working, and have played their due role.

[0090] (2-3) When the total expansion displacement falls into the reference expansion displacement range and the variance is greater than the preset variance threshold, it is determined that the gas turbine cylinder is expanding normally and the elastic support plate has a rigidity change section, and the rigidity change section is located based on the curvature of multiple curve segments.

[0091] If the total expansion displacement falls within the reference expansion displacement range, but the bending uniformity is poor, it indicates that the elastic support plate may have a rigidity variation section. Although it can still provide normal support and expansion displacement, it indicates a certain degree of deterioration, which requires attention from relevant personnel.

[0092] (2-4) When the total expansion displacement is less than the lower limit of the reference expansion displacement range and the variance is greater than the preset variance threshold, it is determined that the gas turbine cylinder block cannot expand normally and the elastic support plate has a rigidity change section, and the rigidity change section is located based on the curvature of multiple curve segments.

[0093] If the total expansion displacement is less than the lower limit of the reference expansion displacement range, and the bending uniformity is poor, it indicates that the deterioration of the elastic support plate has hindered the normal expansion displacement of the cylinder and needs to be sent to maintenance personnel.

[0094] (2-5) When the total expansion displacement is less than the lower limit of the reference expansion displacement range and the variance is less than or equal to the preset variance threshold, it is determined that the gas turbine cylinder cannot expand normally and the elastic support plate has an overall rigidity change or a rolling resistance defect of the bearings on both sides.

[0095] Finally, if the total expansion displacement is less than the lower limit of the reference expansion displacement range, but the bending uniformity is also relatively high, there are two possible causes: one is that the elastic support plate has an overall change in rigidity (deterioration), and the other is that the bearings on both sides of the U-shaped bracket have rolling resistance defects. In this case, it is also necessary to send the item to maintenance personnel for repair.

[0096] Furthermore, if the elastic support plate has sections of varying rigidity, this application can also locate these sections, thereby providing reference data during the degradation process. The specific process includes:

[0097] A spatially ordered curvature sequence is constructed based on the curvature of multiple curve segments, and a sliding window is used to slide along the curvature sequence based on a pre-constructed sliding window. At each slide, the average value ρ of all curvatures within the sliding window is calculated. step Where step represents the sliding order;

[0098] Calculate the overall average curvature ρ0 of multiple curve segments, and satisfy ρ step The segment corresponding to the sliding window <ρ0×n is taken as the rigid change segment, where n is the set multiplier.

[0099] This application uses sliding translation to extract the average curvature of multiple segments. Segments with an average curvature much smaller than the overall average curvature are considered as rigid variation segments. Other methods can also be used, such as curve fitting combined with horizontal line interception, to locate rigid variation segments.

[0100] The monitoring and early warning module 450 is used to monitor and warn of the displacement of the gas turbine cylinder based on the symmetry verification results and elasticity verification results of the elastic support plate.

[0101] Finally, based on the above analysis process, if the following situations exist, the symmetry check result or elastic check result will be judged as abnormal, and the corresponding abnormal alarm information will be sent to the maintenance personnel, including:

[0102] (1) Defect of asymmetric bending on both sides;

[0103] (2) The gas turbine cylinder expands normally and the elastic support plate has a rigidity variation section;

[0104] (3) The gas turbine cylinder block cannot expand normally and the elastic support plate has a rigidity variation section;

[0105] (4) The gas turbine cylinder block cannot expand normally and the elastic support plate has an overall change in rigidity or a rolling resistance defect in the bearings on both sides.

[0106] like Figure 8 As shown, this application also provides a method for monitoring the displacement of a gas turbine cylinder block, including the following steps:

[0107] S810, acquire the current operating load of the gas turbine, the surface temperature of the gas turbine cylinder block, the tilt image including the elastic support plate, and the expansion displacement at multiple measurement positions of the hot end of the gas turbine cylinder block, wherein the elastic support plate bends when the hot end of the gas turbine cylinder block expands, and the expansion displacement at the multiple measurement positions is acquired by multiple rangefinders.

[0108] S820, extract the reference expansion displacement range of the hot end of the gas turbine cylinder block corresponding to the current operating load and surface temperature from a pre-built reference database;

[0109] S830, The tilted image is processed to obtain the deformation characteristics of the elastic support plate, wherein the deformation characteristics include bending uniformity characteristics and bending symmetry characteristics;

[0110] S840, calculate the comprehensive expansion displacement of the expansion displacement at multiple measurement locations; verify the bending characteristics on both sides of the elastic support plate based on the bending symmetry characteristics of the elastic support plate to obtain the symmetry verification result of the elastic support plate; and verify the comprehensive expansion displacement and the bending uniformity characteristics based on the reference expansion displacement range to obtain the elasticity verification result of the elastic support plate.

[0111] S850, based on the symmetry verification results and elasticity verification results of the elastic support plate, performs displacement monitoring and early warning of the gas turbine cylinder block.

[0112] This invention discloses a gas turbine cylinder block displacement monitoring system and method. The system collects expansion displacement data at multiple locations on the gas turbine cylinder block using displacement sensors. A reference expansion displacement range is determined by collecting data on the gas turbine's operating load and surface temperature, allowing for the assessment of any anomalies in the expansion displacement under the current operating load and surface temperature. Images of the elastic support plate undergoing bending under stress are analyzed, and its bending characteristics are extracted. Analysis of the bending symmetry characteristics determines whether the bending on both sides of the elastic support plate is symmetrical. Combined with the reference expansion displacement range, the overall expansion displacement, and the bending uniformity characteristics of the elastic support plate, it can be determined whether the elastic support plate hinders the cylinder block's expansion and whether it has caused increased stiffness under high-temperature conditions. This invention, by monitoring the gas turbine cylinder block displacement, effectively monitors for defects in the support structure in real time, solving the problem of discovering and maintaining equipment only after severe deterioration.

Claims

1. A gas turbine cylinder displacement monitoring system, characterized in that, Including the following steps: The data acquisition module is used to acquire the current operating load of the gas turbine, the surface temperature of the gas turbine cylinder, the tilt image including the elastic support plate, and the expansion displacement at multiple measurement positions of the hot end of the gas turbine cylinder. The elastic support plate bends when the hot end of the gas turbine cylinder expands, and the expansion displacement at the multiple measurement positions is acquired by multiple rangefinders. The reference data module is used to extract the reference expansion displacement range of the hot end of the gas turbine cylinder block corresponding to the current operating load and surface temperature from a pre-built reference database. An image processing module is used to process the tilted image to obtain the deformation characteristics of the elastic support plate, wherein the deformation characteristics include bending uniformity characteristics and bending symmetry characteristics; The analysis module is used to calculate the comprehensive expansion displacement at multiple measurement locations; to verify the bending characteristics on both sides of the elastic support plate based on the bending symmetry characteristics of the elastic support plate, thereby obtaining the symmetry verification result of the elastic support plate; and to verify the comprehensive expansion displacement and the bending uniformity characteristics based on the reference expansion displacement range, thereby obtaining the elasticity verification result of the elastic support plate. The monitoring and early warning module is used to monitor and warn of the displacement of the gas turbine cylinder based on the symmetry verification results and elasticity verification results of the elastic support plate.

2. The gas turbine cylinder displacement monitoring system according to claim 1, characterized in that, The expansion displacement at multiple measurement positions of the hot end of the gas turbine cylinder is acquired by LVDT sensors. The iron cores of the multiple LVDT sensors are in contact with the hot end of the gas turbine cylinder via a transmission bracket. The movement direction of the iron cores of the multiple LVDT sensors is consistent with the expansion offset direction of the gas turbine cylinder.

3. The gas turbine cylinder displacement monitoring system according to claim 1, characterized in that, The process of constructing the reference database includes: The expansion data of the gas turbine at multiple test time points are obtained, wherein the expansion data includes operating load value, surface temperature value and expansion displacement; The bloated data is first divided based on the operating load to obtain multiple bloated datasets, wherein each bloated dataset contains bloated data within a range of operating load. The expansion dataset is divided a second time based on the surface temperature value to obtain multiple expansion data subsets, wherein each expansion data subset contains expansion data for a surface temperature range under a running load range; Expansion data with abnormal expansion displacement in the expansion data subset are removed to obtain the target set; the average value and standard deviation of the expansion displacement of all expansion data in the target set are calculated, and a displacement reference range is constructed based on the average value and standard deviation; and a reference database is constructed based on the displacement parameter range of multiple surface temperature ranges under multiple operating load ranges.

4. The gas turbine cylinder displacement monitoring system according to claim 1, characterized in that, The tilted image is processed to obtain the deformation characteristics of the elastic support plate, including: The tilted image is preprocessed to obtain a preprocessed image, wherein the preprocessing methods include grayscale processing and high-pass filtering; Extract the contour features of the preprocessed image to obtain a contour image; and perform coarse localization on the contour image based on the pre-constructed bounding box to obtain the region of interest of the contour image. Morphological processing is performed on the contour features within the region of interest, and closed contours are selected after morphological processing. The size and rectangularity of each closed contour are also extracted. The closed contour that satisfies the preset screening conditions in both size and rectangularity is used as the outer contour of the elastic support plate. Extract the two long sides, side1 and side2, of the outer contour of the elastic support plate, and perform curve fitting on the two long sides, side1 and side2, to obtain two target curves, curve1 and curve2, on both sides of the elastic support plate. Extract multiple sampling points from the two target curves curve1 and curve2 respectively. i In this case, the curve lengths between adjacent sampling points are the same; Calculate the tangents to the target curve at multiple sampling points, and calculate the angle θ between the tangents at adjacent sampling points. i_i-1 And the angle θ between the tangents of adjacent sampling points. i_i-1 Based on the curve length S of adjacent sampling points i_i-1 Calculate curve segment i_i-1 curvature ρ i_i-1 , ρ i_i-1 =θ i_i-1 / S i_i-1 ; The average curvatures ρ1 and ρ2 of multiple curve segments of two target curves curve1 and curve2 are calculated based on the curvature of multiple curve segments. The curvatures of multiple curve segments of the two target curves curve1 and curve2 are used as the bending uniformity feature, and the average curvature of the two target curves curve1 and curve2 is used as the bending symmetry feature.

5. The gas turbine cylinder displacement monitoring system according to claim 4, characterized in that, The comprehensive expansion displacement is calculated from multiple measurement locations, including: S1. Calculate the average value of the expansion displacement at the multiple measurement positions, and after normalizing the expansion displacement at the multiple measurement positions, calculate the displacement variance of the multiple normalized expansion displacements. S2. Compare the displacement variance with the set displacement variance threshold. If the displacement variance is greater than the set displacement variance threshold, it is determined that there is uneven temperature in the cylinder. After waiting for the target time, the expansion displacement of multiple measurement positions is reacquired and the process returns to step S1. S3. When the displacement variance is less than or equal to the set displacement variance threshold, the average value of the expansion displacement at the multiple measurement locations is taken as the comprehensive expansion displacement D. average .

6. The gas turbine cylinder displacement monitoring system according to claim 4, characterized in that, Based on the bending symmetry characteristics of the elastic support plate, the bending characteristics on both sides of the elastic support plate are verified to obtain the symmetry verification result of the elastic support plate, including: Calculate the difference between the average curvature ρ1 of the target curve curve1 and the average curvature ρ2 of the target curve curve2, |ρ1-ρ2|, and ensure that |ρ1-ρ2| > Δρ. max When the elastic support plate is found to have a defect of asymmetrical bending on both sides, it is determined that the elastic support plate has this defect.

7. The gas turbine cylinder displacement monitoring system according to claim 4, characterized in that, Based on the reference expansion displacement range, the comprehensive expansion displacement and the bending uniformity characteristics are verified to obtain the deformation elasticity verification result of the elastic support plate, including: The curvature of the multiple curve segments is calculated and normalized, and the variance of the multiple normalized curvatures is calculated. The comprehensive expansion displacement is compared with the reference expansion displacement range. When the comprehensive expansion displacement falls into the reference expansion displacement range and the variance is less than or equal to a preset variance threshold, the elastic support plate is determined to be normal. When the total expansion displacement falls within the reference expansion displacement range and the variance is greater than the preset variance threshold, it is determined that the gas turbine cylinder is expanding normally and the elastic support plate has a rigidity change section, and the rigidity change section is located based on the curvature of multiple curve segments. When the total expansion displacement is less than the lower limit of the reference expansion displacement range and the variance is greater than the preset variance threshold, it is determined that the gas turbine cylinder block cannot expand normally and the elastic support plate has a rigidity change section, and the rigidity change section is located based on the curvature of multiple curve segments. When the total expansion displacement is less than the lower limit of the reference expansion displacement range and the variance is less than or equal to the preset variance threshold, it is determined that the gas turbine cylinder block cannot expand normally and the elastic support plate has an overall rigidity change or a rolling resistance defect in the bearings on both sides.

8. The gas turbine cylinder displacement monitoring system according to claim 7, characterized in that, Based on the curvature positioning of rigid variation sections of multiple curve segments, including: A spatially ordered curvature sequence is constructed based on the curvature of multiple curve segments, and a sliding window is used to slide along the curvature sequence based on a pre-constructed sliding window. At each slide, the average value ρ of all curvatures within the sliding window is calculated. step Where step represents the sliding order; Calculate the overall average curvature ρ0 of multiple curve segments, and satisfy ρ step The segment corresponding to the sliding window <ρ0×n is taken as the rigid change segment, where n is the set multiplier.

9. The gas turbine cylinder displacement monitoring system according to claim 1, characterized in that, Based on the symmetry verification results and elasticity verification results of the aforementioned elastic support plate, displacement monitoring and early warning of the gas turbine cylinder block are performed, including: If the symmetry verification result or the elasticity verification result of the elastic support plate is abnormal, the abnormal symmetry verification result or the abnormal elasticity verification result will be sent to the target object.

10. A method for monitoring the displacement of a gas turbine cylinder block, characterized in that, include: The current operating load of the gas turbine, the surface temperature of the gas turbine cylinder, the tilt image including the elastic support plate, and the expansion displacement at multiple measurement positions of the hot end of the gas turbine cylinder are acquired. The elastic support plate bends when the hot end of the gas turbine cylinder expands. The expansion displacement at the multiple measurement positions is acquired by multiple rangefinders. Extract the reference expansion displacement range of the hot end of the gas turbine cylinder block corresponding to the current operating load and surface temperature from a pre-built reference database; The tilted image is processed to obtain the deformation characteristics of the elastic support plate, wherein the deformation characteristics include bending uniformity characteristics and bending symmetry characteristics; The comprehensive expansion displacement is calculated from multiple measurement locations; the bending characteristics on both sides of the elastic support plate are verified based on the bending symmetry characteristics of the elastic support plate to obtain the symmetry verification result of the elastic support plate; and the comprehensive expansion displacement and the bending uniformity characteristics are verified based on the reference expansion displacement range to obtain the elasticity verification result of the elastic support plate. Displacement monitoring and early warning of the gas turbine cylinder are performed based on the symmetry verification results and elasticity verification results of the elastic support plate.

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