A method for detecting the sealing of a gas supply pipeline after installation of a heavy-duty gas turbine

Abstract

The present application relates to the technical field of pipeline sealing detection, and particularly relates to a heavy-duty gas turbine post-installation gas supply pipeline sealing detection method. In the present application, temperature values in a thermal image frame of a gas supply pipeline peripheral measurement point are arranged according to spatial coordinates of the measurement point to generate temperature distribution data, and high-frequency signal components in a time domain signal of a sound wave are energy-interpolated according to spatial coordinates of the measurement point to generate sound wave energy distribution data. Spatial sliding windows are used to synchronously traverse the temperature distribution data and the sound wave energy distribution data, and the correlation between sound wave energy values and temperature values is calculated bit by bit. The position with the largest correlation is taken as a sound-heat coupling center, so that synchronous correlation analysis of the temperature distribution data and the sound wave energy distribution data is realized.

Description

Technical Field

[0001] This invention relates to the field of pipeline sealing testing technology, specifically to a method for testing the sealing of gas supply pipelines after the installation of a heavy-duty gas turbine. Background Technology

[0002] The gas supply pipeline of a heavy-duty gas turbine includes numerous flange connections and weld locations. To ensure the safe operation of the gas supply pipeline after the installation of the heavy-duty gas turbine, it is necessary to use testing methods to confirm whether there are any gas leaks at each connection point before the pipeline is put into operation or after maintenance, in order to avoid safety accidents caused by gas leaks.

[0003] In response, Chinese invention patent CN106500925A discloses a gas leak detection system, device, and method for GIS equipment. It generates infrared images using an infrared scanner and determines whether they represent gas leaks. If a leak is detected, the leak location is sent to an acoustic emission scanner, which uses the energy values ​​detected by three acoustic emission detection probes to determine the accurate leak point. Chinese invention patent CN122306327A discloses a micro-leakage gap detection system and method for internal combustion engine cylinder blocks. It periodically introduces high-pressure gas into the cylinder block. During the pressure holding phase, ultrasonic sensors and thermal imaging components collect ultrasonic data and abnormal cold point data. The location of the leak is determined by combining the three-dimensional coordinates of the abnormal cold points with the ultrasonic data.

[0004] However, the existing technologies still have the following shortcomings: they lack the ability to correlate the outputs of acoustic detection and infrared thermography, thus making it impossible to determine the leak location based on the correlation analysis results. Flange locations and weld locations are structural features in pipelines prone to leaks, but existing technologies do not establish a spatial correlation between leak location and flange or weld locations within the pipeline structure. This results in a lack of comparison between the final leak location and the structural features of the pipeline, and it is impossible to distinguish whether the leak is at a connection point or within the pipe itself, thus failing to provide maintenance personnel with a basis for differentiated maintenance strategies. Summary of the Invention

[0005] The purpose of this invention is to overcome the defects of the prior art and provide a method for sealing detection of gas supply pipeline after installation of heavy-duty gas turbine, including the following steps: arranging the temperature values ​​in the thermal image frame of the measuring point on the periphery of the gas supply pipeline according to the spatial coordinates of the measuring point to generate temperature distribution data; extracting the high-frequency signal components in the time domain signal of the sound wave and performing energy interpolation according to the spatial coordinates of the measuring point to generate sound wave energy distribution data.

[0006] The temperature distribution data and sound energy distribution data are traversed synchronously using a spatial sliding window. The correlation between the sound energy value and the temperature value is calculated bit by bit, and the position with the highest correlation is taken as the sound-thermal coupling center.

[0007] Calculate the spatial distance between the acoustic-thermal coupling center and each flange and weld location in the gas supply pipeline, and identify the location with the smallest spatial distance as the potential leak point.

[0008] Based on the structural layout and direction of the gas supply pipeline, potential leak points are connected to each measuring point to form a spatial connection line; a spatial ray is drawn based on the direction of the spatial connection line to delineate the projection envelope area, and the centroid of the projection envelope area is taken as the leak location.

[0009] Leakage levels are classified based on the energy accumulation and correlation of high-frequency signal components, and a seal detection conclusion is generated by combining the pressure attenuation per unit time of the gas supply pipeline and the location of the leak.

[0010] Compared with the prior art, the present invention has the following beneficial effects: 1. The present invention generates temperature distribution data by arranging the temperature values ​​in the thermal image frame of the gas supply pipeline according to the spatial coordinates of the measuring points, and generates sound wave energy distribution data by interpolating the high-frequency signal components in the time domain signal of the sound wave according to the spatial coordinates of the measuring points. The temperature distribution data and the sound wave energy distribution data are traversed synchronously with a spatial sliding window, and the correlation between the sound wave energy value and the temperature value is calculated bit by bit. The position with the highest correlation is taken as the sound-thermal coupling center, thus realizing the synchronous correlation analysis of temperature distribution data and sound wave energy distribution data.

[0011] 2. This invention calculates the spatial distance between the acoustic-thermal coupling center and the positions of flanges and welds in the gas supply pipeline. The position with the smallest spatial distance is identified as the potential leak point. This establishes a spatial correlation between the location of the leak point and the structural features of the pipeline, such as flanges and welds, which are prone to leakage. Furthermore, based on the structural layout and direction of the gas supply pipeline, the final leak location is determined. The leak location is compared with the center position of the flange end face and the center position of the weld. The leak location is marked as either a connection leak or a pipe body leak. This provides a basis for maintenance personnel to take differentiated maintenance measures based on the type of leak location. Attached Figure Description

[0012] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0013] Figure 1 This is a schematic diagram of the detection method of the present invention; Figure 2 This is a schematic diagram of the process for determining the acoustic-thermal coupling center in this invention; Figure 3 This is a schematic diagram of the process for identifying potential leakage points in this invention; Figure 4 This is a schematic diagram illustrating the process of obtaining the leak location according to the present invention; Figure 5 This is a schematic diagram illustrating the process of classifying leakage levels according to the present invention; Figure 6 This is a schematic diagram illustrating the dynamic changes in the correlation difference and the spatial distance between the acoustic-thermal coupling center and the sealing node in this invention. Figure 7 This is a dynamic comparison diagram of the pressure decay per unit time of the gas supply pipeline, the preset pressure decay threshold, the proportion of highly correlated windows, and the proportional threshold in this invention. Detailed Implementation

[0014] Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the invention. Furthermore, it should be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale.

[0015] The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the invention or its application or use. Techniques, methods, and apparatus known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and apparatus should be considered part of the specification.

[0016] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values.

[0017] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0018] The following describes in detail, with reference to the accompanying drawings, a specific scheme for a method of detecting the sealing of a gas supply pipeline after the installation of a heavy-duty gas turbine, provided by the present invention.

[0019] Please see Figure 1 The flowchart shows a method for detecting the sealing of a gas supply pipeline after the installation of a heavy-duty gas turbine provided by the present invention. Specifically, it includes the following steps: Step S1: Arrange the temperature values ​​in the thermal image frame of the measuring point on the periphery of the gas supply pipeline according to the spatial coordinates of the measuring point to generate temperature distribution data; extract the high-frequency signal components in the time domain signal of the sound wave and perform energy interpolation according to the spatial coordinates of the measuring point to generate sound wave energy distribution data.

[0020] Since the gas supply pipeline of a heavy-duty gas turbine is located inside the casing, the space around the pipeline is the main channel for sound wave propagation and temperature diffusion. Therefore, this invention chooses to place the measuring points around the gas supply pipeline, so that the temperature changes and sound wave signals generated by the leakage can be propagated to each measuring point through the surrounding space.

[0021] The process of setting up the measuring points is as follows: along the outer space of the gas supply pipeline, with the midpoint between the inner wall of the gas turbine casing and the outer wall of the gas supply pipeline as the reference plane, a measuring point is set at a set interval along the length of the gas supply pipeline on the reference plane.

[0022] To avoid spatial duplication of signals collected from adjacent measuring points and to ensure measurement coverage of the pipe section between adjacent flanges, this invention uses 1.5 times the diameter of the gas supply pipeline as the set spacing. The diameter of the gas supply pipeline is read from the three-dimensional design model of the gas supply pipeline. During actual testing, the set spacing can be adjusted according to the structure of the gas supply pipeline. For example, the diameter of the gas supply pipeline can be used as the set spacing at bends or tees in the gas supply pipeline to avoid insufficient test data due to large distances between measuring points.

[0023] After the measuring points are set up, a spatial rectangular coordinate system is established with the center of the bottom surface of the gas turbine casing as the origin, the direction perpendicular to the bottom surface of the gas turbine casing as the Z-axis, and the direction of the gas supply pipeline inlet as the X-axis. Positioning targets are installed at each measuring point location, and the spatial position of each target relative to the origin is measured using a total station or laser rangefinder to obtain the three-dimensional coordinates of each measuring point within the gas turbine casing space. Then, a detection medium, either dry air or nitrogen, is introduced into the gas supply pipeline. Once the internal pressure of the gas supply pipeline reaches the design pressure value recorded in the gas supply pipeline design document, the pressure is maintained.

[0024] Because when leaking gas is ejected from the high-pressure side to the low-pressure side, the gas expands and absorbs heat, causing the temperature around the leak point to drop. At the same time, high-pressure gas generates high-frequency sound waves when passing through the leak gap. Therefore, thermal images and acoustic time-domain signals are acquired at each measuring point to jointly detect the leak from both thermal and acoustic dimensions.

[0025] The specific acquisition process is as follows: an infrared acoustic imager is installed at each measuring point and the signal acquisition end of the infrared acoustic imager is oriented towards the gas supply pipeline. The infrared acoustic imager synchronously acquires the infrared radiation signal and sound wave signal at each measuring point in real time, generating a thermal image frame and sound wave time domain signal corresponding to each measuring point; the temperature value of each measuring point is the temperature value indicated by the corresponding pixel in the thermal image frame.

[0026] Simultaneously, pressure sensors are installed at the pressure detection ports of the gas supply lines. All infrared acoustic imagers and pressure sensors are connected to the same data acquisition unit via data cables to ensure that thermal image frames, acoustic time-domain signals, and pressure values ​​are aligned in time.

[0027] After obtaining the thermal image frames and acoustic time-domain signals corresponding to each measuring point, temperature distribution data is first generated based on the thermal image frames. Specifically, based on the three-dimensional coordinates of each measuring point, the square root of the sum of the squared differences in coordinates between any two measuring points along the X-axis, Y-axis, and Z-axis is taken to obtain the spatial distance between any two measuring points.

[0028] Simultaneously, a 3D laser scanning device is used to perform a full-space scan of the gas supply pipeline, acquiring spatial point cloud data of the pipeline surface. The spatial point cloud data is filtered to remove outliers and noise points. Then, the point cloud is divided into equally spaced segments along the length of the gas supply pipeline, with the segment spacing being half the pipeline diameter to avoid overly dense segmentation. All point clouds within each segment are projected onto a plane perpendicular to the segment's length. The coordinates of all point clouds within the segment in two orthogonal directions on the plane are summed and divided by the total number of point clouds to obtain the center point of the current segment. The center points of each segment are connected sequentially along the length of the gas supply pipeline to form a spatial coordinate sequence of the pipeline centerline. The spatial direction between any two adjacent coordinate points in the spatial coordinate sequence is taken as the direction of the pipeline. All directions are arranged sequentially along the pipeline centerline to form the direction of the gas supply pipeline.

[0029] Next, the search range is defined with each measuring point as the center and the set interval as the spatial search distance. Other measuring points besides the center are searched within the search range. Starting from the searched measuring point, the measuring points located on both sides of the gas supply pipeline direction and whose line connecting them to the starting point does not intersect the pipeline wall are marked as the spatial adjacent measuring points of the current measuring point.

[0030] For any two measuring points, if one measuring point is marked as a spatially adjacent measuring point of the other measuring point, then the two measuring points are spatially adjacent measuring points.

[0031] After obtaining the spatially adjacent measuring points, each measuring point and its spatially adjacent measuring points are connected by straight line segments to obtain the connecting edges corresponding to each measuring point. The connecting edges of all measuring points are merged to form a triangular network covering the gas supply pipeline space inside the gas turbine casing. In the triangular network, the three-dimensional coordinates of each measuring point are the vertex coordinates of the triangular network, and the temperature value of each measuring point is used as the additional attribute value of the corresponding vertex, thereby generating temperature distribution data.

[0032] Secondly, acoustic energy distribution data is generated based on the acoustic time-domain signal. Specifically, time-frequency transformation is performed on the acoustic time-domain signal at each measuring point, i.e., a short-time Fourier transform is performed on the acoustic time-domain signal at each measuring point, and the signal is segmented and windowed using a Hanning window. The window function slides along the time axis with a set overlap rate, and a Fourier transform is performed on the signal within each time window to obtain the amplitude distribution of the signal at different frequencies (the specific process is existing technology and will not be elaborated here). The amplitude distributions of all time windows are arranged in chronological order to form the time-spectrum data of the corresponding measuring point. The horizontal axis of the time-spectrum data represents time, and the vertical axis represents frequency.

[0033] Based on this, signal components with frequencies higher than the upper limit of the main frequency band of the ambient background noise are extracted from the time-spectrum data of each measuring point and denoted as high-frequency signal components. These high-frequency signal components characterize the energy distribution of high-frequency acoustic signals that may be caused by gas leakage at the corresponding measuring point.

[0034] The process of obtaining the main frequency band range of ambient background noise is as follows: In a silent state where the gas supply pipeline is not filled with the detection medium, ambient background noise signals are collected using an infrared acoustic imager. Time-frequency transformation is performed on the ambient background noise signals at each measuring point to obtain the background noise time-spectrum data for each measuring point. The arithmetic mean of the amplitudes at all frequency positions in the background noise time-spectrum data for each measuring point is calculated. In acoustic emission detection, the threshold level must be set at least 6 dB higher than the background noise level, corresponding to a signal amplitude approximately twice the background noise amplitude. Based on this, the frequency range where the amplitude exceeds twice the obtained arithmetic mean is taken as the main frequency band range of ambient background noise; thus, the main frequency band range of ambient background noise for each measuring point is obtained.

[0035] Then, the integration time window is determined based on the continuous distribution interval of the high-frequency signal components on the time axis. Here, the time axis refers to the time dimension in the time spectrum data.

[0036] The specific determination process is as follows: Calculate the arithmetic mean of the amplitude at all frequency positions in the high-frequency band signal. When a certain amplitude exceeds the obtained arithmetic mean, it indicates that the signal strength at the time corresponding to this amplitude is higher than the average noise level, which corresponds to the effective component of the leaked sound wave signal. Therefore, the time point when the amplitude exceeds the obtained arithmetic mean is marked as the effective time point.

[0037] The consecutive valid time points are then grouped into a continuous distribution interval. The start time of the continuous distribution interval is used as the start time of the integration time window, and the end time of the continuous distribution interval is used as the end time of the integration time window. If multiple continuous distribution intervals exist, the continuous distribution interval with the longest duration is selected as the integration time window.

[0038] After determining the integration time window, the amplitude of the high-frequency signal components is integrated within the integration time window. Specifically, the amplitude is used as the integrand, time is used as the integration variable, the start time of the integration time window is used as the lower limit of integration, and the end time of the integration time window is used as the upper limit of integration. A definite integral is performed on the amplitude in the time dimension, and the result is defined as the acoustic energy value. This yields the acoustic energy value at each measurement point, which reflects the total energy of the high-frequency acoustic signal at the corresponding measurement point.

[0039] Subsequently, using the three-dimensional coordinates of all measuring points as vertices and the same measuring point coordinates as the temperature distribution data as the vertex positions, an interpolation grid covering the gas supply pipeline space inside the gas turbine casing was constructed. The interpolation grid was constructed using the same vertex structure as the triangular mesh to ensure that the temperature distribution data and the acoustic energy distribution data are consistent in spatial location. Simultaneously, the acoustic energy values ​​of each measuring point were used as the vertex attribute values ​​of the interpolation grid to generate acoustic energy distribution data.

[0040] Please see Figure 2 Step S2: Simultaneously traverse the temperature distribution data and sound wave energy distribution data using a spatial sliding window, calculate the correlation between the sound wave energy value and the temperature value bit by bit, and take the position with the highest correlation as the sound-thermal coupling center.

[0041] In practical implementation, because the edge connections of the triangular mesh reflect the spatial adjacency of the measuring points, and the triangular mesh covers the gas supply pipeline space inside the gas turbine casing, the interpolation mesh, although also using the same measuring point coordinates as vertices, is mainly used for spatial interpolation of acoustic energy values. Therefore, a spatial sliding window is constructed based on the triangular mesh to ensure that the coverage area of ​​the spatial sliding window has a clear boundary definition.

[0042] In the temperature distribution data, with the current vertex as the center of the window, adjacent vertices are connected outwards along the edge of the triangular mesh, and each complete circle of connections to adjacent vertices constitutes a connection level. After each level of connection is completed, all connected vertices, along with the center of the window, are used as a spatial sliding window. The coverage of the spatial sliding window expands outwards as the number of connection levels increases, while the center of the window remains at the current vertex. After all connection levels for the current vertex are completed, the center of the window is moved to the next vertex along the gas supply pipeline, and the above step-by-step connection operation is repeated at the new vertex. After each spatial sliding window is formed, the temperature value and sound wave energy value of each vertex within the new spatial sliding window are extracted simultaneously.

[0043] The order in which vertices are connected and added to the spatial sliding window during its formation is denoted as the vertex connection order. Each time a spatial sliding window is formed, the temperature values ​​of all vertices within it are arranged into a temperature vector according to the vertex connection order, and the sound wave energy values ​​at the same vertices are arranged into a sound wave vector in the same order. This facilitates the correspondence analysis between temperature values ​​and sound wave energy values ​​for each vertex.

[0044] Then, along each edge of the triangular mesh, determine whether the order of temperature values ​​at the two vertices of the temperature vector is opposite to the order of sound energy values ​​at the two vertices of the sound wave vector.

[0045] The specific judgment process is as follows: For any edge in the triangular network, this edge connects vertex A and vertex B. The temperature values ​​of vertices A and B are read from the temperature vector. If the temperature value of vertex A is greater than the temperature value of vertex B, the temperature order is recorded as positive; otherwise, the temperature order is recorded as negative. Simultaneously, the sound wave energy values ​​of the same vertices A and B are read from the sound wave vector. If the sound wave energy value of vertex A is greater than the sound wave energy value of vertex B, the sound wave order is recorded as positive; otherwise, the sound wave order is recorded as negative.

[0046] Next, the following judgment is made: if the temperature sequence and the sound wave sequence are both positive or both negative, then the order of the temperature values ​​at the two vertices of the temperature vector is determined to be opposite to the order of the sound wave energy values ​​at the two vertices of the sound wave vector, and the opposite edge is recorded as an acoustic-thermal reverse coupling edge; if the temperature sequence is positive and the sound wave sequence is negative, or the temperature sequence is negative and the sound wave sequence is positive, then the order of the temperature values ​​at the two vertices of the temperature vector is determined to be not opposite to the order of the sound wave energy values ​​at the two vertices of the sound wave vector, and the current edge is not recorded as an acoustic-thermal reverse coupling edge.

[0047] Based on this, the number of acoustic-thermal reverse coupling edges is counted. If the number of acoustic-thermal reverse coupling edges is zero, the correlation degree is recorded as zero; if the number of acoustic-thermal reverse coupling edges is greater than zero, the proportion of the number of acoustic-thermal reverse coupling edges to the total number of edges within the spatial sliding window is calculated as the correlation degree. The correlation degree characterizes the degree of spatial consistency between temperature distribution data and sound wave energy distribution data within the coverage area of ​​the spatial sliding window. The higher the correlation degree, the higher the probability of a leakage point existing within the coverage area of ​​the spatial sliding window.

[0048] After traversing all the vertices of the triangular mesh as the center of the spatial sliding window, the center of the spatial sliding window with the highest correlation is taken as the acoustic-thermal coupling center.

[0049] If multiple spatial sliding windows have the same and highest correlation, the arithmetic mean of the three-dimensional coordinates of the centers of these spatial sliding windows is taken, and the resulting coordinate position is taken as the acoustic-thermal coupling center. In this way, the centers of these spatial sliding windows with the same highest correlation are merged into a representative position.

[0050] Please see Figure 3 Step S3: Calculate the spatial distance between the acoustic-thermal coupling center and the flange and weld positions in the gas supply pipeline, and take the position with the smallest spatial distance as the potential leakage point.

[0051] Because flange and weld connections in gas supply pipelines are the most prone to gas leaks in the pipeline system, they should be prioritized for investigation. The acoustic-thermal coupling center is the most likely spatial location for leaks; therefore, this invention determines potential leak points based on the spatial distance between the acoustic-thermal coupling center and the locations of flanges and welds in the gas supply pipeline.

[0052] Specifically, the 3D coordinates of the center positions of each flange end face and the 3D coordinates of the center positions of each weld are extracted from the 3D design model of the gas supply pipeline. If these cannot be extracted from the 3D design model, existing techniques in the field of point cloud data processing are used to identify the contours and center point positions of each flange end face and the contours and center lines of each weld from the spatial point cloud data of the gas supply pipeline; the 3D coordinates of the center positions of each flange end face and the 3D coordinates of the center positions of each weld are then extracted. All the obtained flange end face center positions and weld center positions are merged into a set of sealing nodes.

[0053] Next, each sealing node in the set of sealing nodes is traversed. Based on the three-dimensional coordinates of the acoustic-thermal coupling center and the current sealing node, the spatial distance between the current sealing node and the acoustic-thermal coupling center is calculated according to the calculation process of the spatial distance between any two measuring points in step S1. The larger the spatial distance, the lower the probability of leakage at the current sealing node; the smaller the spatial distance, the higher the probability of leakage at the current sealing node.

[0054] Based on this, the sealing node with the smallest spatial distance is selected as the initial potential leak point. If multiple sealing nodes with the same and smallest spatial distance exist, then all sealing nodes corresponding to these spatial distances are selected as initial potential leak points.

[0055] However, the minimum spatial distance can only ensure that the sealing node is closest to the acoustic-thermal coupling center in spatial location. Correlation verification needs to be introduced to further verify the initial potential leakage point and avoid the selection of the wrong potential leakage point.

[0056] The verification process is as follows: For all sealing nodes, including the initial potential leak point, determine the triangular facet in the triangulation network that has the smallest spatial distance to each sealing node. A triangular facet is the smallest triangular unit in the triangulation network, formed by connecting three adjacent measurement points.

[0057] Specifically, based on the three-dimensional coordinates of the current sealing node and the three-dimensional coordinates of the three vertices of each triangular facet in the triangular mesh, following the calculation process of the spatial distance between any two measuring points in step S1, the spatial distance from the current sealing node to the three vertices of each triangular facet is calculated, resulting in three spatial distances. The minimum value of the three spatial distances is taken as the spatial distance from the current sealing node to the current triangular facet. All triangular facets are traversed, and the triangular facet with the smallest spatial distance value is taken as the triangular facet with the smallest spatial distance to the current sealing node.

[0058] Then, based on the correlation degree corresponding to the three vertices of the triangular facet with the smallest spatial distance to the current sealing node, the arithmetic mean of the three correlation degrees is calculated as the correlation degree of the sealing node; the difference in correlation degree between each sealing node and the acoustic-thermal coupling center is calculated. The smaller the difference in correlation degree, the closer the correlation degree of the sealing node is to the correlation degree of the acoustic-thermal coupling center, and the higher the probability that the sealing node is a leakage point.

[0059] If the difference in correlation degree of the initial potential leak point is greater than the difference in correlation degree of any of the remaining sealing nodes, then the sealing node with the smallest difference in correlation degree is used to replace the initial potential leak point as the final potential leak point to participate in the calculation of step S4; otherwise, the initial potential leak point is used as the final potential leak point to participate in the calculation of step S4.

[0060] To facilitate the explanation of the correlation verification process for potential leak points, five sealing nodes—F1 flange, W1 weld, F2 flange, W2 weld, and F3 flange—are used to form an exemplary verification sequence. The difference in correlation between each sealing node is calculated based on the spatial distance between the three vertices of a triangular facet and the current sealing node, and the correlation degree corresponding to the three vertices of the triangular facet. The resulting data is used to illustrate the changing relationship of the correlation verification and correction of potential leak point selection in this invention, and does not constitute a limitation on specific gas turbine pipeline detection parameters. Specific parameters may vary, such as... Figure 6 As shown.

[0061] See Figure 6 The F1 flange has the smallest spatial distance (0.6m) between its acoustic-thermal coupling center and the sealing node, making it the initial potential leak point, but its correlation difference is 0.367. The W1 weld has the smallest correlation difference (0.097) between its acoustic-thermal coupling center and the sealing node, with a spatial distance of 0.7m. Since the correlation difference of the initial potential leak point, the F1 flange, is greater than that of the W1 weld among the other sealing nodes, the W1 weld is used instead of the F1 flange as the final potential leak point. This change demonstrates that correlation verification can avoid incorrect selection of potential leak points based solely on minimum spatial distance, ensuring that the final potential leak point simultaneously satisfies both spatial proximity and acoustic-thermal coupling consistency.

[0062] Please see Figure 4Step S4: Based on the structure and direction of the gas supply pipeline, connect the potential leak point with each measuring point to form a spatial connection line; draw a spatial ray based on the direction of the spatial connection line to delineate the projection envelope area, and take the center of gravity of the projection envelope area as the leak location.

[0063] First, based on the structural layout of the gas supply pipeline, the pipe segment to which the potential leak point belongs is determined. The structural layout of the gas supply pipeline refers to the spatial topology of the gas supply pipeline within the gas turbine casing space, including information such as the connection relationships, direction, and diameter of each pipe segment. The structural layout of the gas supply pipeline is obtained from the three-dimensional design model of the gas supply pipeline or the spatial point cloud data obtained in step S1.

[0064] The specific determination process is as follows: Since the potential leak point is located at the center of the flange end face or the center of the weld, and the center of the flange end face and the center of the weld correspond to the connection point of the adjacent pipe section in the structural layout of the gas supply pipeline, the pipe section containing the three-dimensional coordinates of the potential leak point is searched from the structural layout of the gas supply pipeline.

[0065] Next, the spatial point cloud data of the gas supply pipeline is analyzed. Existing point cloud filtering and segmentation algorithms are used to identify the point cloud data of the pipe segment to which potential leak points belong (the specific process is existing technology and will not be detailed here). Cylindrical surface fitting is performed on the point cloud data of the corresponding pipe segment, and the direction of the central axis of the cylinder is taken as the axis direction of the corresponding pipe segment. Then, the point cloud data of the corresponding pipe segment is sliced ​​along the axis direction of the pipe segment; the specific identification, fitting, and slicing processes are existing technology and will not be detailed here. All point clouds within each slice are projected onto a plane perpendicular to the axis of the corresponding pipe segment. Based on the calculation process of the center point of the current segment in step S1, the center point of the slice is calculated similarly. The center points of multiple slices are extracted sequentially along the axis direction of the corresponding pipe segment and connected in spatial order to form the centerline of the corresponding pipe segment.

[0066] Subsequently, following the calculation process of the spatial distance between any two measuring points in step S1, the spatial distance between each center point on the centerline of the pipe section and the potential leak point is calculated. The center point with the smallest spatial distance and its two adjacent center points before and after it are selected, for a total of five center points. This is to avoid the subsequent fitted straight line being easily affected by the positional deviation of a single point, and at the same time to avoid increasing the amount of calculation due to too many selected points. The five center points are fitted into a straight line, and the spatial direction of the straight line is used as the tangent direction of the centerline of the pipe section at the location of the potential leak point.

[0067] Then, the tangent direction of the centerline of the corresponding pipe section at the potential leak point is taken as the direction of the gas supply pipeline at the potential leak point. Starting from the potential leak point, the potential leak point is connected to each measuring point to form a spatial connection line corresponding to each measuring point; the spatial connection line vector is obtained by subtracting the three-dimensional coordinates of the starting point from the three-dimensional coordinates of the endpoint of the spatial connection line, and the direction of the spatial connection line vector corresponding to each measuring point is taken as the spatial projection direction of each measuring point.

[0068] Next, starting from the potential leak point, spatial rays are drawn out along the spatial projection direction of each measuring point. The first measuring point through which the spatial ray passes is taken as the cutoff point. Following the calculation process for the spatial distance between any two measuring points in step S1, the spatial distance between the potential leak point and the cutoff point is calculated. Using the direction of the gas supply pipeline at the potential leak point as the starting reference direction, a plane perpendicular to the starting reference direction is drawn through the potential leak point. First, each cutoff point is projected onto the drawn plane. Then, using the projection of the potential leak point as the center point, and the projection of the cutoff point with the smallest spatial distance as the starting point, the projections of the remaining cutoff points are connected one by one in a clockwise direction. The connection order is used as the spatial orientation order of each cutoff point around the potential leak point.

[0069] Subsequently, according to the spatial orientation of each cutoff point around the potential leak point, the cutoff points on adjacent spatial rays are connected to form closed and non-self-intersecting boundary surfaces. The closed spatial region enclosed by all boundary surfaces is taken as the projection envelope. If a closed spatial region cannot be formed, i.e., the sparse distribution of some ray directions prevents the boundary surface from being completely closed, then the convex hull of the spatial point set formed by all cutoff points is taken as the projection envelope.

[0070] The projection envelope region is an irregular polyhedron in space. The geometric centroid of the projection envelope region is obtained by discretizing it into multiple tetrahedrons, calculating the volume and centroid of each tetrahedron, multiplying the centroid and volume of each tetrahedron and summing the results, and dividing the sum by the sum of the volumes of all tetrahedrons to obtain the weighted average position. The weighted average position is taken as the geometric centroid of the projection envelope region, i.e., the leakage location.

[0071] Among them, the acquisition of convex hull, discretization into tetrahedrons, and calculation of tetrahedron volume and centroid are all existing techniques in the field of computational geometry, and will not be elaborated here.

[0072] Please see Figure 5 Step S5: Based on the energy accumulation and correlation of the high-frequency signal components, the leakage level is classified, and a sealing detection conclusion is generated by combining the pressure attenuation per unit time of the gas supply pipeline and the leakage location.

[0073] In practice, the amplitudes of the high-frequency signal components at each measuring point within the integration time window are squared and summed to obtain the energy accumulation degree at each measuring point. The energy accumulation degree directly reflects the intensity of the acoustic signal generated by the leak. The larger the energy accumulation degree, the stronger the high-frequency acoustic signal received at the measuring point, and the closer the spatial distance between the measuring point and the leak point.

[0074] Based on this, the measuring point corresponding to the maximum energy accumulation among all measuring points is used as the reference measuring point. The ratio of the energy accumulation of each measuring point to the energy accumulation of the reference measuring point is calculated. The larger the ratio, the stronger the leakage sound wave energy received at the measuring point. The measuring point with the largest ratio is selected as the measuring point of interest.

[0075] Then, the correlation scores of all spatial sliding windows are summed and divided by the total number of spatial sliding windows to obtain the average correlation score. Among all spatial sliding windows, those with a correlation score greater than the average correlation score are considered high-correlation windows.

[0076] If there is no correlation degree greater than the average correlation degree among all spatial sliding windows, then it is determined that there is no high correlation window, and the leakage level is judged as low-level leakage.

[0077] The spatial region enclosed by all vertices within a highly correlated window is defined as the spatial range covered by the highly correlated window. If the measurement point of interest is located inside or on the boundary of a highly correlated window, it is determined that the measurement point of interest falls within the spatial range covered by this highly correlated window; otherwise, it is determined that the measurement point of interest does not fall within the spatial range covered by this highly correlated window.

[0078] Next, the proportion of highly correlated windows to the total number of spatial sliding windows is calculated. The larger the proportion of highly correlated windows, the wider the spatial range of acoustic-thermal correlation anomalies and the higher the severity of leakage.

[0079] The first criterion is whether the measurement point falls within the spatial range covered by any highly correlated window, and the second criterion is the proportion of highly correlated windows. The leakage level is classified based on the combination of the first and second criterion.

[0080] The specific classification process is as follows: When the monitoring point falls within the spatial range covered by a high-correlation window, and the proportion of high-correlation windows exceeds a certain threshold, the leakage level is classified as high-level leakage. When the monitoring point falls within the spatial range covered by a high-correlation window, but the proportion of high-correlation windows does not exceed a certain threshold, the leakage level is classified as medium-level leakage. When the monitoring point does not fall within the spatial range covered by a high-correlation window, the leakage level is classified as low-level leakage.

[0081] The process for determining the proportional threshold is as follows: The distance between adjacent flanges is read from the 3D design model of the gas supply pipeline. The distance is divided by the diameter of the gas supply pipeline to obtain an initial ratio. Then, the initial ratio is divided by the sum of the initial ratio and 1 for normalization. The resulting quotient is used as the proportional threshold, which is a dimensionless parameter between 0 and 1. When there are multiple adjacent flange distances in the same gas supply pipeline, the arithmetic mean of all initial ratios is used for normalization.

[0082] Considering that the pressure decay per unit time in the gas supply pipeline reflects the overall sealing performance of the pipeline system, this invention uses the overall sealing performance of the pipeline system as the quantitative basis for the test conclusion. To reduce the impact of temperature fluctuations in the test medium on the pressure measurement results, after filling the gas supply pipeline with the test medium to the design pressure value, it is allowed to stand for at least 30 minutes to allow the temperature to stabilize. Then, the system pressure values ​​of the gas supply pipeline at the start and end times of the test period are obtained using a pressure sensor installed on the gas supply pipeline.

[0083] The detection period refers to the time interval from the start of data collection to the completion of all data collection after the detection medium is filled into the gas supply pipeline.

[0084] Subsequently, the difference in system pressure between the start and end times is calculated. This difference is then divided by the duration of the detection period to obtain the pressure decay per unit time in the gas supply pipeline. A larger pressure decay per unit time in the gas supply pipeline indicates a faster pressure drop in the pipeline system, poorer pipeline sealing performance, and more severe leakage.

[0085] To distinguish whether the leak originates from a pipe connection or the pipe itself, the leak location is compared with the center of the flange end face and the center of the weld. Specifically, the spatial distance between the leak location and the center of each flange end face and each weld is calculated. If the minimum spatial distance is less than or equal to a preset location threshold, the leak location is marked as a connection leak; otherwise, the leak location is marked as a pipe body leak.

[0086] The preset location threshold is set to 15% of the gas supply pipeline diameter. In actual testing, when the pipeline vibrates significantly, it can cause the positioning target of the measuring point to shift, causing the three-dimensional coordinate measurement value of the measuring point to deviate from the true position. This can lead to a positioning deviation in the final calculated leak location. In this case, the preset location threshold needs to be increased to 20% of the gas supply pipeline diameter to avoid missed or incorrect detections due to positioning deviations.

[0087] Subsequently, based on different combinations of leakage level, leakage location marking results, and pressure decay per unit time in the gas supply pipeline, a seal detection conclusion is generated.

[0088] The specific generation process is as follows: When any of the following combinations are present, the generated seal detection conclusion is a seal failure and an emergency repair is prompted: 1) The leakage level is high-level leakage and the pressure decay per unit time of the gas supply pipeline is greater than the preset pressure decay threshold, and the leakage location is marked as a connection leak or a pipe body leak; 2) The leakage level is high-level leakage, the pressure decay per unit time of the gas supply pipeline is less than or equal to the preset pressure decay threshold, and the leakage location is marked as a pipe body leak; 3) The leakage level is medium-level leakage, the pressure decay per unit time of the gas supply pipeline is greater than the preset pressure decay threshold, and the leakage location is marked as a pipe body leak; 4) The leakage level is medium-level leakage, the pressure decay per unit time of the gas supply pipeline is less than or equal to the preset pressure decay threshold, and the leakage location is marked as a pipe body leak; 5) The leakage level is low-level leakage, the pressure decay per unit time of the gas supply pipeline is greater than the preset pressure decay threshold, and the leakage location is marked as a pipe body leak.

[0089] When any of the following combinations are present, the generated seal detection conclusion is seal failure and a planned maintenance is prompted: 1) The leakage level is high-level leakage, the pressure decay per unit time in the gas supply pipeline is less than or equal to the preset pressure decay threshold, and the leakage location is marked as a connection leak; 2) The leakage level is medium-level leakage, the pressure decay per unit time in the gas supply pipeline is greater than the preset pressure decay threshold, and the leakage location is marked as a connection leak; 3) The leakage level is medium-level leakage, the pressure decay per unit time in the gas supply pipeline is less than or equal to the preset pressure decay threshold, and the leakage location is marked as a connection leak; 4) The leakage level is low-level leakage, the pressure decay per unit time in the gas supply pipeline is greater than the preset pressure decay threshold, and the leakage location is marked as a connection leak.

[0090] When the leakage level is low and the pressure decay per unit time in the gas supply pipeline is less than or equal to the preset pressure decay threshold, if the leakage location is marked as a connection leak, the generated seal detection conclusion is "sealing status to be observed" and a planned maintenance is prompted; if the leakage location is marked as a pipe body leak, the generated seal detection conclusion is "sealing status abnormal" and a priority re-inspection is prompted.

[0091] The preset pressure attenuation threshold is determined in advance through calibration tests. Specifically, a reference pipeline with the same structure as the gas supply pipeline under test and confirmed to be leak-free is selected. The maximum allowable leakage rate determined according to the pipeline design documents is applied to the reference pipeline, and the pressure attenuation value after application is measured as the preset allowable pressure attenuation threshold. When the test medium, test pressure, or pipeline volume changes, recalibration is required. The specific calibration process is existing technology and will not be elaborated here.

[0092] To facilitate the explanation of the process of generating leakage level determination and sealing test results, an exemplary test sequence is constructed using 10 consecutive test periods T1 to T10. The pressure decay per unit time in the gas supply pipeline is calculated based on the difference in system pressure values ​​at the start and end of the test period and the duration of the test period; the proportion of highly correlated windows is calculated based on the number of windows with a correlation greater than the average correlation of all windows and the total number of windows; the proportional threshold is calculated based on the distance between adjacent flanges and the diameter of the gas supply pipeline, and is dimensionless. The obtained data is used to demonstrate the linkage between the leakage level classification and the generation of sealing test results in this invention, and does not constitute a limitation on specific gas turbine pipeline test parameters, such as... Figure 7 As shown.

[0093] See Figure 7 During periods T1, T5, and T8, the pressure decay per unit time in the gas supply pipeline all exceeded the preset pressure decay threshold, and the corresponding proportion of high-correlation windows was higher than the proportional threshold. When the monitoring point fell within the space covered by the high-correlation window, the generated seal detection conclusion was seal failure, and an emergency repair was prompted. During periods T2 and T6, the pressure decay per unit time in the gas supply pipeline all exceeded the preset pressure decay threshold, and the corresponding proportion of high-correlation windows was lower than the proportional threshold. When the monitoring point fell within the space covered by the high-correlation window, and the leak location was marked as a leak at the connection point, the generated seal detection conclusion was seal failure, and a planned maintenance was prompted. This linkage corresponds to the closed-loop process of generating seal detection conclusions based on different combinations of leak level, leak location marking results, and pressure decay per unit time, demonstrating that the method adopted in this invention can comprehensively consider acoustic and thermal correlation characteristics, pipeline pressure decay characteristics, and leak location structure type to output differentiated seal detection conclusions and maintenance strategy basis.

[0094] It should be noted that since leakage at the connection point corresponds to the failure of the sealing surface at the flange connection or weld connection, it can be repaired by tightening the flange bolts or repairing the weld, hence the suggestion of planned maintenance. However, leakage in the pipe body corresponds to cracks, holes, or other defects in the pipe section. These defects pose a risk of continued expansion under internal pressure, potentially leading to breakage, thus requiring urgent repair.

[0095] After generating the sealing test result, perform the corresponding operation according to the result type: if the generated sealing test result is sealing failure and prompts emergency repair, immediately send an alarm signal to the operation and maintenance center, and highlight the leak location in the three-dimensional design model of the gas supply pipeline.

[0096] If the generated seal test result indicates seal failure and suggests planned maintenance, a maintenance work order is generated and sent to the operations and maintenance center. The maintenance work order includes the leak location, leak level, leak location marking result, gas supply pipeline pressure decay per unit time, and seal test result.

[0097] If the generated sealing test conclusion is "sealing condition requires observation" and a planned maintenance is recommended, the test data will be recorded, and a re-inspection will be prioritized in the next testing cycle. If the generated sealing test conclusion is "sealing condition is abnormal" and a priority re-inspection is recommended, the test data will be recorded, and a re-inspection will be prioritized in the next testing cycle.

[0098] If a re-inspection confirms that there is no leakage, the seal test result is updated to "seal is normal" and archived; if a re-inspection confirms that there is leakage, the process is transferred to maintenance.

[0099] The detection data includes temperature values, acoustic energy values, and pressure attenuation per unit time at each measuring point, as well as leak location, leak level, leak location marking results, pressure attenuation per unit time in the gas supply pipeline, and seal detection conclusions. Re-inspection refers to re-acquiring thermal images and acoustic time-domain signals at confirmed leak locations, and then performing steps such as leak level determination and seal detection conclusion generation to verify the accuracy of the initial inspection conclusions.

[0100] The above embodiments can be implemented, in whole or in part, by software, hardware, firmware, or any other combination thereof. When implemented in software, the above embodiments can be implemented, in whole or in part, as a computer program product.

[0101] Those skilled in the art will recognize that the modules and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this invention.

[0102] In addition, the functional modules in the various embodiments of the present invention can be integrated into one processing module, or each module can exist physically separately, or two or more modules can be integrated into one module.

[0103] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

[0104] Finally, the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for testing the sealing of a gas supply pipeline after the installation of a heavy-duty gas turbine, characterized in that, Includes the following steps: The temperature values ​​in the thermal image frames of the measuring points around the gas supply pipeline are arranged according to the spatial coordinates of the measuring points to generate temperature distribution data. The high-frequency signal components in the time domain signal of the sound wave are extracted and energy interpolated according to the spatial coordinates of the measuring points to generate sound wave energy distribution data. The temperature distribution data and sound energy distribution data are traversed synchronously using a spatial sliding window. The correlation between the sound energy value and the temperature value is calculated bit by bit, and the position with the highest correlation is taken as the sound-thermal coupling center. Calculate the spatial distance between the acoustic-thermal coupling center and each flange and weld location in the gas supply pipeline, and identify the location with the smallest spatial distance as the potential leak point. Based on the structural layout and direction of the gas supply pipeline, potential leak points are connected to each measuring point to form a spatial connection line; a spatial ray is drawn based on the direction of the spatial connection line to delineate the projection envelope area, and the centroid of the projection envelope area is taken as the leak location. Leakage levels are classified based on the energy accumulation and correlation of high-frequency signal components, and a seal detection conclusion is generated by combining the pressure attenuation per unit time of the gas supply pipeline and the location of the leak.

2. The method for testing the sealing of a gas supply pipeline after installation of a heavy-duty gas turbine according to claim 1, characterized in that, The process of generating temperature distribution data is as follows: Obtain the three-dimensional coordinates of each measuring point outside the gas supply pipeline within the gas turbine casing space and the temperature values ​​of the corresponding pixels in the thermal image frame; Based on the spatial distance between each pair of measuring points and the direction of the gas supply pipeline, determine the spatially adjacent measuring points between each measuring point; Each measuring point and its spatially adjacent measuring points are connected to form a triangular network covering the gas supply pipeline space inside the gas turbine casing. The three-dimensional coordinates of each measuring point are used as the vertex coordinates of the triangular network, and the temperature value of each measuring point is used as the additional attribute value of the corresponding vertex to generate temperature distribution data.

3. The method for testing the sealing of a gas supply pipeline after installation of a heavy-duty gas turbine according to claim 2, characterized in that, The process of generating sound wave energy distribution data is as follows: Acquire acoustic time-domain signals from various measuring points around the gas supply pipeline; perform time-frequency transformation on the acoustic time-domain signals from each measuring point, and extract signal components with frequencies higher than the upper limit of the main frequency band of the ambient background noise from the time-frequency transformation results, which are recorded as high-frequency signal components. The integration time window is determined based on the continuous distribution interval of the high-frequency signal components on the time axis. The amplitude of the intercepted high-frequency signal components is integrated within the integration time window, and the integration result is defined as the sound wave energy value. Thus, the sound wave energy value of each measuring point is obtained. An interpolation grid covering the gas supply pipeline space inside the gas turbine casing is constructed using the three-dimensional coordinates of all measuring points as vertices. The acoustic energy values ​​of each measuring point are used as the attribute values ​​of the interpolation grid vertices to generate acoustic energy distribution data.

4. The method for testing the sealing of a gas supply pipeline after installation of a heavy-duty gas turbine according to claim 3, characterized in that, The process of determining the acoustic-thermal coupling center is as follows: In the temperature distribution data, with the current vertex as the center of the window, adjacent vertices are connected outwards along the edge of the triangular mesh level by level; after each level of connection is completed, all connected vertices together with the center of the window are used as a spatial sliding window; after all connection levels of the current vertex are completed, the center of the window is moved to the next vertex along the gas supply pipeline, and the level-by-level connection operation is re-executed at the new vertex. After each spatial sliding window is formed, the temperature value and sound wave energy value of each vertex in the new spatial sliding window are extracted simultaneously. Each time a spatial sliding window is formed, the temperature values ​​of all vertices within it are arranged into a temperature vector according to the vertex connection order, and the sound wave energy values ​​at the same vertex are arranged into a sound wave vector in the same order. Along each edge of the triangular mesh, determine whether the order of temperature values ​​at the two vertices of the temperature vector is opposite to the order of sound energy values ​​at the two vertices of the sound wave vector; mark the opposite edges as acoustic-thermal reverse coupling edges, and calculate the proportion of the number of acoustic-thermal reverse coupling edges to the total number of edges in the spatial sliding window as the correlation degree; After traversing all the vertices of the triangular mesh as the center of the spatial sliding window, the center of the spatial sliding window with the highest correlation is taken as the acoustic-thermal coupling center.

5. The method for testing the sealing of a gas supply pipeline after installation of a heavy-duty gas turbine according to claim 2, characterized in that, The process of identifying potential leak points includes: Obtain the three-dimensional coordinates of the center position of each flange end face and the three-dimensional coordinates of the center position of each weld in the gas supply pipeline, and merge them into a set of sealing nodes; Calculate the spatial distance between the acoustic-thermal coupling center and each sealing node in the set of sealing nodes; select the sealing node with the smallest spatial distance as the initial potential leakage point.

6. The method for testing the sealing of a gas supply pipeline after installation of a heavy-duty gas turbine according to claim 5, characterized in that, The process of identifying potential leak points also includes: For all sealing nodes, including the initial potential leakage point, determine the triangular facet in the triangular network with the smallest spatial distance to each sealing node, and use the average value of the correlation degree corresponding to the three vertices of the determined triangular facet as the correlation degree of the sealing node; calculate the difference in correlation degree between each sealing node and the acoustic-thermal coupling center. If the difference in correlation between the initial potential leak point and any of the remaining sealing nodes is greater than the difference in correlation between the sealing nodes, then the sealing node with the smallest difference in correlation will replace the initial potential leak point and become the final potential leak point participating in the formation of the spatial connection line; otherwise, the initial potential leak point will be used as the final potential leak point participating in the formation of the spatial connection line.

7. The method for testing the sealing of a gas supply pipeline after installation of a heavy-duty gas turbine according to claim 1, characterized in that, The process of obtaining the spatial projection direction is as follows: Starting from the potential leak point, connect the potential leak point to each measuring point to form a spatial connection line corresponding to each measuring point; subtract the three-dimensional coordinates of the starting point from the three-dimensional coordinates of the endpoint of the spatial connection line to obtain the spatial connection line vector; use the direction of the spatial connection line vector corresponding to each measuring point as the spatial projection direction of each measuring point.

8. The method for testing the sealing of a gas supply pipeline after installation of a heavy-duty gas turbine according to claim 7, characterized in that, The process of determining the leak location is as follows: Starting from the potential leak point, spatial rays are drawn out along the spatial projection direction of each measuring point, and the position of the first measuring point through which the spatial ray passes is the cut-off point. According to the spatial orientation sequence of each cutoff point around the potential leak point, connect the cutoff points on adjacent spatial rays to form a boundary surface, and use the closed spatial area enclosed by all the boundary surfaces as the projection envelope area. Calculate the geometric centroid of the projection envelope and use it as the leakage location.

9. A method for testing the sealing of a gas supply pipeline after installation of a heavy-duty gas turbine, as described in claim 4, is characterized in that... The process of classifying leakage levels is as follows: The energy accumulation of each measuring point is obtained by squaring the amplitude of the high-frequency signal component within the integration time window and then summing the results. The measuring point corresponding to the maximum energy accumulation among all measuring points is used as the reference measuring point. The ratio of the energy accumulation of each measuring point to the energy accumulation of the reference measuring point is calculated, and the measuring point with the largest ratio is used as the measuring point of interest. Among all spatial sliding windows, those with a correlation degree greater than the average correlation degree of all spatial sliding windows are considered as high correlation windows, and the proportion of the number of high correlation windows to the total number of all spatial sliding windows is calculated. The first criterion is whether the measurement point falls within the spatial range covered by any highly correlated window, and the second criterion is the proportion of highly correlated windows. The leakage level is classified based on the combination of the first and second criterion.

10. A method for testing the sealing of a gas supply pipeline after installation of a heavy-duty gas turbine according to claim 1, characterized in that, The process of generating a seal test result is as follows: Obtain the system pressure values ​​of the gas supply pipeline at the start and end of the detection period; calculate the difference between the system pressure values ​​at the start and end of the detection period, and divide the difference by the duration of the detection period to obtain the pressure decay of the gas supply pipeline per unit time. Calculate the spatial distance between the leak location and the center of each flange end face and the center of each weld. If the minimum spatial distance is less than or equal to the preset location threshold, mark the leak location as a connection leak; otherwise, mark the leak location as a pipe body leak. Based on different combinations of leakage level, leakage location marking results, and gas supply pipeline pressure decay per unit time, a seal detection conclusion is generated.

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