Electrostatic probe for early fault detection of heavy duty gas turbine and use method thereof

Abstract

The invention provides an electrostatic probe for early fault detection of a heavy duty gas turbine and a use method thereof, and is applied to the field of early fault diagnosis of gas turbines, the electrostatic probe comprises a probe 1, a first insulating cover, a second insulating cover, a connecting block, a BNC connector and a shielding cover; the shielding cover contains the top end of the first insulating cover; the BNC connector is installed on the outer surface of the top end of the shielding cover, and an inner core of the BNC connector penetrates through the shielding cover and is arranged in the shielding cover. The bottom end of the probe is a detection end, and the detection end of the probe extends out of the first insulating cover; the top end of the probe penetrates through the first insulating cover and then is installed in the shielding cover. The probe is connected with the BNC connector through a connecting block arranged at the top end. The connecting block is connected with an inner core of the BNC connector; the second insulating cover is arranged in the shielding cover and is coaxial with the shielding cover. One end of the second insulating cover abuts against the inner top wall of the shielding cover. The early fault of the heavy duty gas turbine can be accurately detected by detecting the abnormal charged particles in the gas circuit pipeline.

Description

Technical Field

[0001] This invention relates to the field of early fault diagnosis of gas turbines, and more particularly to an electrostatic probe for early fault detection of heavy-duty gas turbines and its method of use. Background Technology

[0002] A gas turbine is a thermal engine that converts the chemical energy of fuel into mechanical energy. When a gas turbine operates, it first draws in air through the intake port, which then compresses it into high-pressure air by the compressor. This high-pressure air is sent to the combustion chamber, where it mixes with fuel and burns to form extremely hot gas. The high-temperature, high-pressure gas then enters the turbine, driving it to perform work and output power. The hot gas, after performing work, is discharged from the exhaust port. Heavy-duty gas turbines are capable of generating electricity efficiently and cleanly, and are mainly used in machinery, power generation, and marine industries, forming the cornerstone of modern energy and industrial systems.

[0003] In the early stages of a gas turbine failure, an abnormal increase in particle detachment occurs due to friction and collision between mechanical components. These detached particles are often charged and are discharged through the gas pipeline along with the high-speed gas flow. Detecting the electrostatic field of these tiny particles in the gas pipeline can reflect the particle detachment situation and is a novel method for detecting faults in heavy-duty gas turbines.

[0004] Heavy-duty gas turbines are high-speed rotating machines operating under extreme high-temperature and high-pressure environments. Failure to detect faults in their early stages can trigger a chain reaction of damage, leading to unit scrapping or even casualties. Patent CN120067791A proposes a method for diagnosing gas turbine faults by collecting vibration data. However, relying solely on vibration data may not be sufficient for accurate diagnosis in the early stages of a fault. Summary of the Invention

[0005] To address the aforementioned problems, this invention provides an electrostatic probe for early fault detection in heavy-duty gas turbines and its application method. It detects the electric field of abnormal particles detached from the gas turbine's gas path due to friction and collision between mechanical structures. By identifying these abnormally charged particles, it solves the challenge of early fault detection in gas turbines. An installation scheme for the electrostatic probe in the gas path pipeline is proposed. In terms of probe design, it overcomes the problems of low sensitivity and inability to withstand high-temperature, high-velocity gases found in conventional pipeline probes. Specifically, it includes:

[0006] An electrostatic probe for early fault detection in heavy-duty gas turbines includes: a probe, a first insulating cover, a second insulating cover, a connecting block, a BNC connector, and a shielding cover;

[0007] The shielding cover encompasses the top of the first insulating cover;

[0008] The BNC connector is mounted on the outer surface of the top of the shield, and the inner core of the BNC connector passes through the shield and is disposed inside the shield;

[0009] The bottom end of the probe is the detection end, which extends from inside the first insulating cover;

[0010] The tip of the probe passes through the first insulating cover and is installed inside the shielding cover. The probe is connected to the BNC connector through a connecting block located at the tip.

[0011] The connecting block is connected to the inner core of the BNC connector;

[0012] The second insulating cover is disposed inside the shielding cover and is coaxially disposed with the shielding cover. One end of the second insulating cover abuts against the inner top wall of the shielding cover, and the other end of the second insulating cover abuts against the top of the probe.

[0013] Optionally, the first insulating cover is columnar, and a columnar channel is provided inside the first insulating cover for mounting the probe.

[0014] A circumferential groove is provided on the side wall of the first insulating cover, and the groove is used to install the shielding cover;

[0015] A square recess is provided on the side wall of the first insulating cover. The square recess is connected to the slot. There are two square recesses in total, and the two square recesses are arranged opposite each other.

[0016] Optionally, the shielding cover includes: a cylindrical cover, a convex ring, and a semi-circular ring fixing member;

[0017] The cylindrical cover is cylindrical in shape, and the convex ring is integrally and coaxially arranged with the cylindrical cover. The convex ring is sleeved on the outer wall of the bottom end of the cylindrical cover. The convex ring is provided with threaded holes and rectangular holes; two rectangular holes are provided, and the two rectangular holes are distributed on the convex ring at 180° opposite to each other.

[0018] Two semi-circular ring fasteners are installed below the convex ring and are used to connect the shielding cover and the first insulating cover.

[0019] Optionally, the two semi-circular ring fasteners are arranged symmetrically;

[0020] Each semi-circular ring fastener is arranged in the shape of a semi-circular ring, and each semi-circular ring fastener has a directional protrusion at the bottom and block-shaped mounting ears at the top of both ends of each semi-circular ring fastener.

[0021] When the semi-circular ring fastener connects the first insulating cover and the shielding cover:

[0022] Two semi-circular ring fasteners are clamped onto the first insulating cover, and the inner edges of the two semi-circular ring fasteners are inserted into the slots.

[0023] Each square protrusion can enter the corresponding square recess on the first insulating cover;

[0024] Two relatively fitted block mounting ears pass through a rectangular hole on the same convex ring.

[0025] Optionally, the probe includes: a disk, reinforcing ribs, and a needle tube;

[0026] One end of the needle is installed inside the first shielding cover via a disc, and the lower surface of the disc abuts against the upper panel of the end of the first shielding cover.

[0027] The other end of the needle extends out of the first shielding cover;

[0028] The reinforcing rib connects the side wall of the needle tube to the lower surface of the disc.

[0029] Optionally, the second insulating cover is cylindrical, the material of the second insulating cover is aluminum oxide, and the inner cavity of the second insulating cover encloses the connecting block.

[0030] Optionally, the connecting block is made of copper.

[0031] A method of using an electrostatic probe for early fault detection in heavy-duty gas turbines, comprising the aforementioned electrostatic probe for early fault detection in heavy-duty gas turbines, including:

[0032] S1. At least four electrostatic probes for early fault detection of heavy-duty gas turbines are evenly arranged on the inner wall of the metal gas pipeline, wherein each electrostatic probe for early fault detection of heavy-duty gas turbines is connected to an electrostatic detection terminal.

[0033] S2. When particles are present in the metal gas pipeline, the electrostatic probe for early fault detection of heavy-duty gas turbines captures the particles. The time-domain electrostatic signal generated by the probe sensing in each electrostatic probe for early fault detection of heavy-duty gas turbines is transmitted to the electrostatic detection terminal for signal fusion and enhancement processing to obtain an enhanced signal dataset.

[0034] S3. Based on the enhanced signal dataset, perform charge fitting and velocity linear fitting respectively to obtain the particle charge linear fitting formula and the particle velocity linear fitting formula.

[0035] Optionally, the time-domain electrostatic signal generated by the probe sensing within each electrostatic probe used for early fault detection of heavy-duty gas turbines in S2 is transmitted to the electrostatic detection terminal for signal fusion and enhancement processing, resulting in an enhanced signal dataset including:

[0036] The average value of the electrostatic signals detected by all probes is obtained by averaging the values ​​of all electrostatic probe signals.

[0037] The standard deviation and bias of the signal are calculated based on the average value of all electrostatic probe signals.

[0038] The enhanced signal dataset is obtained based on the standard deviation and bias of the signal.

[0039] Optionally, the standard deviation of the signal is formulated as formula (1):

[0040] (1)

[0041] s1 is the standard deviation of the signal, and N is the number of all electrostatic probes; The average value of all electrostatic probe signals. The electrostatic signal detected by the i-th electrostatic probe;

[0042] (2)

[0043] s2 represents the signal deviation, and j and k are the probe numbers. Let be the potential of the j-th probe. Let be the potential of the k-th probe;

[0044] The calculation formula for the data in the enhanced signal dataset is formula (3):

[0045] (3)

[0046] The linear regression data represents the data within the enhanced signal dataset, i.e., the data from the probe array; a and b are the regression coefficients determined through simulation, where a = 0.384 and b = -3.034. =0.217.

[0047] The above technical solution has at least the following advantages compared with the existing technology:

[0048] Accurate detection of early-stage faults in heavy-duty gas turbines is possible by detecting abnormally charged particles in the gas pipeline. The device is installed at the smaller diameter end of the widening pipe, balancing the detection challenges posed by particle velocity and electric field strength. This invention features a simple assembly method that eliminates the need for adhesive bonding, facilitating maintenance, repair, and parts replacement. The connection method is reliable, resulting in higher structural strength and the ability to withstand higher temperatures and wind speeds. The probe length, insulation layer thickness, and materials of this invention are rationally designed, allowing for a longer insertion distance into the pipe and a shorter distance from charged particles, enabling more accurate measurement of particle charge. A longer probe causes greater electric field distortion, enhancing the signal. The probe design for electrostatic induction in this invention is hollow, reducing weight with minimal reduction in structural strength.

[0049] The shielding cover and probe design of this invention for connecting sensors or connectors are universal, compatible with various connection methods, and suitable for various solutions. This invention has a relatively simple structure, is inexpensive, and is easy to mass-produce and scale up. Attached Figure Description

[0050] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying 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.

[0051] Figure 1 A perspective view of an electrostatic probe according to one embodiment of the present invention;

[0052] Figure 2 A cross-sectional view of an electrostatic probe according to one embodiment of the present invention;

[0053] Figure 3 A partially enlarged schematic diagram of an electrostatic probe according to one embodiment of the present invention;

[0054] Figure 4 A three-dimensional view of an electrostatic probe according to one embodiment of the present invention;

[0055] Figure 5 A perspective view of the shielding cover of an electrostatic probe according to one embodiment of the present invention;

[0056] Figure 6 A perspective view and a cross-sectional view of the first insulating cover of an electrostatic probe according to one embodiment of the present invention;

[0057] Figure 7 A perspective view of the second insulating cover of an electrostatic probe according to one embodiment of the present invention;

[0058] Figure 8 A perspective view of a semi-circular ring fixing component of an electrostatic probe according to one embodiment of the present invention;

[0059] Figure 9 A perspective view of the connection block of an electrostatic probe according to one embodiment of the present invention;

[0060] Figure 10 A perspective view of a semi-circular ring fixing component of an electrostatic probe according to one embodiment of the present invention;

[0061] Figure 11 This is a schematic diagram of the installation of four electrostatic probes in a metal gas pipeline according to one embodiment of the present invention.

[0062] Marker explanation:

[0063] 1. Probe; 11. Disc; 12. Reinforcing rib; 13. Needle tube;

[0064] 2. First insulating cover; 21. Slot; 22. Square groove;

[0065] 3. Second insulating cover;

[0066] 4. Connecting block;

[0067] 5. BCN connector;

[0068] 6. Shielding cover; 61. Cylindrical cover; 62. Raised ring; 63. Semi-circular ring fastener; 64. Block mounting ear; 65. Square protrusion; 66. Rectangular hole. Detailed Implementation

[0069] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the described embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0070] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains. The terms “first,” “second,” and similar terms used in this invention do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, the terms “an,” “a,” or “the,” and similar terms do not indicate a quantity limitation, but rather indicate the presence of at least one. The terms “comprising,” “including,” or “including,” and similar terms mean that the element or object preceding the word encompasses the element or object listed following the word and its equivalents, without excluding other elements or objects. The terms “connected,” “linked,” or “connected,” and similar terms are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect.

[0071] This invention proposes an electrostatic probe for early fault diagnosis by detecting the electrostatic field in the gas pipeline of a heavy-duty gas turbine. This probe enables the detection of charged particles during faults and solves the environmental adaptability challenges posed by the large diameter of heavy-duty gas turbine pipelines and the high wind speeds and temperatures within them. Specifically, it includes:

[0072] like Figures 1 to 10 As shown, the present invention provides an electrostatic probe for early fault detection in heavy-duty gas turbines in a first aspect, comprising: a probe, a first insulating cover, a second insulating cover, a connecting block, a BNC connector, and a shielding cover; the shielding cover encompasses the top end of the first insulating cover; the BNC connector is mounted on the outer surface of the top end of the shielding cover, and the inner core of the BNC connector passes through the shielding cover and is disposed within the shielding cover; the bottom end of the probe is a detection end, and the detection end of the probe extends from inside the first insulating cover; the top end of the probe passes through the first insulating cover and is installed inside the shielding cover, and the probe is connected by a... The connecting block at the top is connected to the BNC connector; the connecting block is connected to the inner core of the BNC connector; the second insulating cover is disposed inside the shielding cover and is coaxially disposed with the shielding cover, one end of the second insulating cover abuts against the inner top wall of the shielding cover, and the other end of the second insulating cover abuts against the disk position at the top of the probe. The second insulating cover has a columnar stepped structure but has an inwardly extending convex ring structure at the bottom. The bottom surface of the convex ring structure can abut against the upper surface of the disk structure, so that the second insulating cover is confined between the lower surface of the shielding cover and the upper surface of the disk of the probe and confined within the internal space of the shielding cover.

[0073] In one specific implementation, the probe is installed in the gas path piping of a heavy-duty gas turbine. When the heavy-duty gas turbine is running, friction and collisions between its mechanical components cause charged particles to detach. These particles can be detected by the electrostatic probe as they pass through the gas path piping. The detected electrostatic field strength can reflect the operating condition of the heavy-duty gas turbine and diagnose early electrostatic faults.

[0074] The probe is installed on a gradually widening or constant-diameter pipe. The particle velocity is higher where the pipe diameter is smaller, and the probe is farther from the particles where the diameter is larger. Using the COMSOL Multiphysics 6.0 finite element analysis platform and theoretical analysis, it was demonstrated that the limiting factor for detection capability is primarily the distance between the probe and the particles. The probe is installed at the smaller diameter end of the gradually widening pipe, with the probe mounting diameter less than 8 meters and the lower end of the probe less than 3 meters from the center of the pipe.

[0075] In this example, it needs to be installed on a pipe with a diameter of approximately 5 meters that gradually widens to 7 meters. Since the closer the probe is to the particle, the stronger the signal is, it is preferred to install it at a diameter of 5.5 meters.

[0076] In one specific embodiment, the first insulating cover is columnar, and a columnar channel is provided inside the first insulating cover for installing the probe; a slot is provided around the side wall of the first insulating cover for installing the shielding cover; a square recess is provided on the side wall of the first insulating cover, and the square recess communicates with the slot, and the number of square recesses is two, with the two square recesses facing each other.

[0077] The shielding cover includes: a cylindrical cover, a convex ring, and semi-circular ring fasteners; the cylindrical cover is cylindrical in shape, the convex ring is integrally formed with the cylindrical cover and coaxially arranged, the convex ring is sleeved on the outer wall of the bottom end of the cylindrical cover, and the convex ring is provided with threaded holes and rectangular holes; two rectangular holes are provided, and the two rectangular holes are distributed on the convex ring at 180° opposite to each other; two semi-circular ring fasteners are provided and installed below the convex ring and are used to connect the shielding cover and the first insulating cover. The two semi-circular ring fasteners are symmetrically arranged; each semi-circular ring fastener is arranged in a semi-circular shape, with a directional protrusion at the bottom of each semi-circular ring fastener and block-shaped mounting ears at the top of both ends of each semi-circular ring fastener; when the semi-circular ring fasteners connect the first insulating cover and the shielding cover: the two semi-circular ring fasteners clamp onto the first insulating cover and the inner edges of the two semi-circular ring fasteners are engaged in the slots; each square protrusion can enter the corresponding square recess on the first insulating cover; the two relatively close block-shaped mounting ears pass through the rectangular hole on the same protrusion ring, and the two relatively close block-shaped mounting ears are supported by bolt connection and fixation.

[0078] The first insulating cover, made of high-temperature resistant insulating material, insulates the probe from the gas pipeline. The groove at the top of the first insulating cover matches the reinforcing ribs on the probe, and the square recess on the side matches the square protrusions of the two semi-circular ring fasteners. Alternatively, the insulating layer can be sintered with the probe or base during manufacturing. These connection methods prevent signal transmission interruption caused by probe rotation due to vibrations from a heavy gas turbine. To obtain a sufficiently strong signal, the thickness of the first insulating cover is greater than 10mm.

[0079] In this example, the first insulating cover is made of aluminum oxide, is 235mm long and 15mm thick, and is connected using a slotted fitting method.

[0080] The two semi-circular ring fasteners have almost identical structures and are made of metal. The block-shaped mounting ears at both ends of the two semi-circular ring fasteners pass through the rectangular holes of the shield.

[0081] The two mating block mounting ears have corresponding round holes and can be fixed with hexagonal nuts, round nuts, or square-head nuts and countersunk bolts.

[0082] Furthermore, the two semi-circular ring fasteners can be fixed to the convex ring by means of bolts or other methods.

[0083] Additionally, the two semi-circular ring fasteners support four pre-machined threaded holes on the four circular holes for connection with bolts and the air duct (the duct to be installed). Alternatively, a threaded hole can be pre-machined on the duct for connection using a threaded base. The threaded base structure is as follows: Figure 10 As shown.

[0084] In one specific embodiment, the probe includes: a disk, reinforcing ribs, and a needle tube;

[0085] One end of the needle tube is installed inside the first shielding cover via a disc, and the lower surface of the disc abuts against the upper panel of the end of the first shielding cover; the other end of the needle tube extends out of the first shielding cover; the reinforcing rib connects the side wall of the needle tube to the lower surface of the disc.

[0086] In one specific implementation, the probe is sealed at both ends and made of a high-temperature resistant conductive material. The upper end of the probe consists of a disc and a needle tube connected together, while the lower end of the tube is sealed. The upper end of the disc has a threaded hole, and reinforcing ribs are provided at the connection point with the tube. Using the COMSOL Multiphysics 6.0 finite element analysis platform and theoretical analysis, it has been proven that a hollow design with an inner diameter to outer diameter ratio greater than 0.4 and less than 0.6 reduces weight with minimal reduction in structural strength. To obtain a sufficiently strong signal, the probe extends beyond the first insulating cover by more than 150 mm and is less than 3 meters from the center of the tube.

[0087] In this example, a 316 stainless steel tube with an outer diameter of 10mm, an inner diameter of 5mm, and a length of 530mm is used. Both ends are sealed, and a disc is connected to the upper end. An M3 threaded hole is provided at the upper end of the disc. The probe extends 200mm beyond the insulating layer.

[0088] Furthermore, when the lower end of the probe is placed in an electric field, an induced charge is generated at the lower end of the probe, and an equal amount of opposite induced charge is generated at the upper end of the probe. Measurement methods include: the charge generating an electric field at the upper end of the probe, which is then measured directly by an electric field sensor; measurement via connecting an external sensor using a connecting block and a BNC connector; and measurement by inserting a wire into a threaded hole, securing it with screws, and then connecting it to a sensor.

[0089] The second insulating cover is cylindrical and made of aluminum oxide. The inner cavity of the second insulating cover encloses a connecting block, which is made of copper.

[0090] The connecting block has a columnar structure, and a through hole is provided on the axis of the connecting block for the inner core of the BCN connector to pass through. The inner core of the BCN connector is connected to the probe through the through hole of the connecting block.

[0091] Accurate detection of early-stage faults in heavy-duty gas turbines is possible by detecting abnormally charged particles in the gas pipeline. The device is installed at the smaller diameter end of the widening pipe, balancing the detection challenges posed by particle velocity and electric field strength. This invention features a simple assembly method that eliminates the need for adhesive bonding, facilitating maintenance, repair, and parts replacement. The connection method is reliable, resulting in higher structural strength and the ability to withstand higher temperatures and wind speeds. The probe length, insulation layer thickness, and materials of this invention are rationally designed, allowing for a longer insertion distance into the pipe and a shorter distance from charged particles, enabling more accurate measurement of particle charge. A longer probe causes greater electric field distortion, enhancing the signal. The probe design for electrostatic induction in this invention is hollow, reducing weight with minimal reduction in structural strength.

[0092] The shielding cover and probe design of this invention for connecting sensors or connectors are universal, compatible with various connection methods, and suitable for various solutions. This invention has a relatively simple structure, is inexpensive, and is easy to mass-produce and scale up.

[0093] like Figure 11 As shown, in a second aspect, the present invention provides a method of using an electrostatic probe for early fault detection in heavy-duty gas turbines, comprising the aforementioned electrostatic probe for early fault detection in heavy-duty gas turbines, including:

[0094] S1. At least four electrostatic probes for early fault detection of heavy-duty gas turbines are evenly arranged on the inner wall of the metal gas pipeline, wherein each electrostatic probe for early fault detection of heavy-duty gas turbines is connected to an electrostatic detection terminal.

[0095] The reason why at least four electrostatic probes (hereinafter also referred to as electrostatic probes) are used for early fault detection in heavy-duty gas turbines is as follows;

[0096] The MSE of different numbers of probe arrays were calculated based on simulation experiments, and the results are shown in Table 1 below:

[0097] Table 1

[0098]

[0099] In this embodiment, to quantitatively evaluate the impact of the number of probes on the performance of the probe array, the mean square error (MSE) is introduced as an evaluation index for the accuracy of the system's detection signal, as shown in the following formula:

[0100]

[0101] n is the total number of probes. Let be the average value of the potentials of n probes. Linear regression values ​​of the probe array.

[0102] The results show that the MSE of the four-probe array is significantly lower than that of the three-probe array (from 1.55 to 0.34), while the signal stability and signal-to-noise ratio are greatly improved. In practical applications, the four-probe array can effectively distinguish complex situations such as multiple particles passing simultaneously and non-uniform particle flows. In more complex application scenarios, higher detection accuracy can be achieved by increasing the number of probes. This probe array is suitable for electrostatic detection inside pipes with higher flow rates and larger dimensions, such as fault monitoring of gas pipelines downstream of gas turbine combustion chambers. Figures 1 to 3 The diagrams show the distribution of 4, 5, and 6 electrostatic probe arrays within the pipe, respectively.

[0103] The electrostatic probe array comprises a ceramic layer and a metal core; the ceramic layer is made of alumina, zirconium oxide, silicon nitride, or aluminum nitride; the ceramic layer is in physical contact or electrically insulated from the metal pipe, and the metal core is electrically insulated from the metal pipe. Multiple electrostatic probe arrays are uniformly installed circumferentially on the inner wall of the metal gas pipe; the electrostatic probes within the electrostatic probe array are fixed to the inner wall of the metal gas pipe using screws.

[0104] S2. When particles are present in the metal gas pipeline, the electrostatic probe for early fault detection of heavy-duty gas turbines captures the particles. The time-domain electrostatic signal generated by the probe sensing in each electrostatic probe for early fault detection of heavy-duty gas turbines is transmitted to the electrostatic detection terminal for signal fusion and enhancement processing to obtain an enhanced signal dataset, including:

[0105] When particles are present in the metal gas pipeline, a fault is determined to exist in the metal gas pipeline, and the electrostatic probe array captures the electrostatic signals of the particles. Generally, particles do not exist in pipelines; they only appear when a certain fault occurs, such as erosion, corrosion, or burning inside the combustion chamber. In such cases, particles will be present in the gas turbine pipeline. To roughly pinpoint the fault location, it is necessary to know the parameters of the particles and then compare their physical properties to roughly determine the type of particles. Since differences in particle size lead to different amounts of charge carried by the particles, causing changes in the electrostatic charge level in the gas pipeline, abnormal particulate matter can be detected based on changes in the electrostatic field of the gas pipeline. Therefore, this application uses an electrostatic probe array for detection.

[0106] The time-domain electrostatic signals generated by the electrostatic probes in each electrostatic probe array are transmitted to the electrostatic monitoring terminal for signal fusion and enhancement processing, resulting in an enhanced signal dataset including:

[0107] The average value of all electrostatic probe signals is obtained by averaging the electrostatic signals detected by all electrostatic probes.

[0108] The formula for calculating the average is: ;

[0109] N is the total number of electrostatic probes; The average value of all electrostatic probe signals. Let be the electrostatic signal detected by the i-th electrostatic probe.

[0110] The standard deviation and bias of the signal are calculated based on the average value of all electrostatic probe signals.

[0111] The formula for the standard deviation s1 of the signal is formula (1):

[0112] (1)

[0113] The formula for the deviation of the signal is formula (2):

[0114] (2)

[0115] S2 represents the signal deviation, and j and k represent the probe numbers. Let be the potential of the j-th probe. Let be the potential of the k-th probe.

[0116] The calculation formula for the data in the enhanced signal dataset is formula (3):

[0117] (3)

[0118] The linear regression data represents the data within the enhanced signal dataset, i.e., the data from the probe array; a and b are the regression coefficients determined through simulation, where a = 0.384 and b = -3.034. =0.217.

[0119] S3. Based on the enhanced signal dataset, perform charge fitting and velocity linear fitting respectively to obtain the particle charge linear fitting formula and the particle velocity linear fitting formula.

[0120] For linear regression data The charge quantity is fitted, and the formula for linear fitting of charge quantity is:

[0121] ;in The particle charge is the result of linear fitting. The slope is fitted to the "output-charge" equation. The intercept for fitting the charge quantity;

[0122] For linear regression data Perform a Fast Fourier Transform (FFT) to transform the time-domain signal Convert the signal to the frequency domain and normalize it to obtain the normalized frequency domain signal. ;

[0123] Acquire signal 3dB bandwidth The linear fitting formula for velocity is: ;

[0124] in The particle velocity is the linearly fitted value, and k is the slope of the "signal 3dB bandwidth - velocity" fitting. The intercept for velocity fitting.

[0125] In one specific implementation, the probe array consists of four electrostatic probes that are evenly distributed circumferentially on the wall of the metal gas pipeline. The included angle between adjacent probes is 90°, ensuring good spatial coverage and symmetry of the electrostatic signal across the pipeline cross-section.

[0126] Each electrostatic probe is fixed to a pre-drilled mounting hole in the pipe wall via a threaded connection, ensuring mechanical strength and airtightness. The probe structure consists of an outer ceramic isolation layer and an inner metal electrode core. The ceramic isolation layer is made of high-purity alumina ceramic (…). It possesses excellent high-temperature insulation properties and mechanical strength, and can operate for extended periods in high-temperature environments above 800°C. The metal electrode core is made of a high-temperature alloy, primarily composed of nickel, chromium, and iron, exhibiting excellent high-temperature oxidation and corrosion resistance, making it suitable for the high-temperature, high-pressure gas flow environment of gas turbines.

[0127] The metal electrode core extends into the pipe, and its exposed length needs to be adjusted according to the actual pipe dimensions. A ceramic insulating layer ensures complete electrical insulation between the metal electrode core and the metal pipe wall, preventing grounding interference.

[0128] Four probes are connected to a multi-channel high-precision electrometer via shielded high-temperature signal cables. Each channel has a sampling rate of over 4kHz to meet the requirements for acquiring higher frequency signals. After pre-amplification and filtering, the signals are synchronously acquired by a high-speed data acquisition card and transmitted to the host computer for processing.

[0129] In this embodiment, the signals collected by the four probes are denoted as follows: , , , hereinafter referred to as The signal processing flow is as follows:

[0130] Calculate the average value of the four probe signals: ;

[0131] Calculate the standard deviation s1 and bias s2 of the four-probe array;

[0132] ;

[0133] ;

[0134] Perform linear regression to obtain the enhanced signal dataset. :

[0135] ;

[0136] Where the regression coefficient a 1−4 and b 1−4 Determined through preliminary calibration experiments;

[0137] right Perform linear fitting of charge: ;

[0138] Speed ​​inversion is still based on the 3dB bandwidth of the signal after FFT transformation. : .

[0139] Based on the above calculations, the charge and velocity of the abnormal particles can be obtained, and the type of particles can be predicted based on the relevant parameters to pinpoint the range of the situation.

[0140] By employing an array of more than two electrostatic probes circumferentially distributed along the pipe wall, this invention fundamentally overcomes the limitations of single-point monitoring. The array design achieves spatial coverage of the entire pipe cross-section, ensuring effective detection regardless of whether abnormal particles pass through the pipe's center or edge, significantly reducing the probability of missed detection. By introducing a linear regression algorithm to fuse multiple signals (calculating the mean, standard deviation, and bias), random noise and systematic errors caused by the randomness of particle positions are effectively suppressed, thereby significantly improving the signal-to-noise ratio and the accuracy of charge inversion. As shown in Table 1, the mean square error of the four-probe array is reduced by more than 93% compared to the two-probe array, demonstrating its high-precision detection capability under complex operating conditions.

[0141] This method can detect the charge and speed of abnormal particles. Based on these two parameters, those skilled in the art, combined with experience or other characteristics, can determine the material of the particles. Based on the material of the particles, those skilled in the art can have a general idea of ​​the location of the abnormal particles in the original device, and can troubleshoot the fault point within the range, effectively preventing the occurrence of larger faults.

[0142] Furthermore, this invention proposes to use multiple algorithms such as probe array signal mean method, linear regression method, and nonlinear regression method to analyze the charge of charged particles and improve the calculation accuracy. It also proposes to use Fast Fourier Transform (FFT) and time domain method to solve the motion state and position of charged particles. This invention can realize real-time high-precision inversion of the charge, motion speed and position of abnormal charged particles in gas pipelines. It has the advantages of fast response, high accuracy and strong anti-interference ability. It is suitable for fault early warning and health management in high temperature and high flow rate gas pipeline environments such as heavy gas turbines.

[0143] The following points need to be explained:

[0144] (1) The accompanying drawings of the embodiments of the present invention only involve the structures involved in the embodiments of the present invention. Other structures can refer to the general design.

[0145] (2) For clarity, the thickness of layers or regions is enlarged or reduced in the drawings used to describe embodiments of the invention, i.e., these drawings are not drawn to scale. It is understood that when an element such as a layer, film, region or substrate is referred to as being “above” or “below” another element, the element may be “directly” located “above” or “below” the other element or there may be intermediate elements.

[0146] (3) Where there is no conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other to obtain new embodiments.

[0147] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. The scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. An electrostatic probe for early fault detection in heavy-duty gas turbines, characterized in that, include: Probe, first insulating cover, second insulating cover, connecting block, BNC connector, and shielding cover; The shielding cover encompasses the top of the first insulating cover; The BNC connector is mounted on the outer surface of the top of the shield, and the inner core of the BNC connector passes through the shield and is disposed inside the shield; The bottom end of the probe is the detection end, which extends from inside the first insulating cover; The tip of the probe passes through the first insulating cover and is installed inside the shielding cover. The probe is connected to the BNC connector through a connecting block located at the tip. The connecting block is connected to the inner core of the BNC connector; The second insulating cover is disposed inside the shielding cover and is coaxially disposed with the shielding cover. One end of the second insulating cover abuts against the inner top wall of the shielding cover, and the other end of the second insulating cover abuts against the top of the probe.

2. The electrostatic probe for early fault detection of heavy-duty gas turbines according to claim 1, characterized in that, The first insulating cover is cylindrical, and a cylindrical channel is provided inside the first insulating cover. The cylindrical channel inside the first insulating cover is used to install the probe. A circumferential groove is provided on the side wall of the first insulating cover, and the groove is used to install the shielding cover; A square recess is provided on the side wall of the first insulating cover. The square recess is connected to the slot. There are two square recesses in total, and the two square recesses are arranged opposite each other.

3. The electrostatic probe for early fault detection of heavy-duty gas turbines according to claim 2, characterized in that, The shielding cover includes: a cylindrical cover, a convex ring, and a semi-circular ring fixing component; The cylindrical cover is cylindrical in shape, and the convex ring is integrally and coaxially arranged with the cylindrical cover. The convex ring is sleeved on the outer wall of the bottom end of the cylindrical cover. The convex ring is provided with threaded holes and rectangular holes; two rectangular holes are provided, and the two rectangular holes are distributed on the convex ring at 180° opposite to each other. Two semi-circular ring fasteners are installed below the convex ring and are used to connect the shielding cover and the first insulating cover.

4. The electrostatic probe for early fault detection of heavy-duty gas turbines according to claim 3, characterized in that, The two semi-circular ring fasteners are arranged symmetrically; Each semi-circular ring fastener is arranged in the shape of a semi-circular ring, and each semi-circular ring fastener has a directional protrusion at the bottom and block-shaped mounting ears at the top of both ends of each semi-circular ring fastener. When the semi-circular ring fastener connects the first insulating cover and the shielding cover: Two semi-circular ring fasteners are clamped onto the first insulating cover, and the inner edges of the two semi-circular ring fasteners are inserted into the slots. Each square protrusion can enter the corresponding square recess on the first insulating cover; Two relatively fitted block mounting ears pass through a rectangular hole on the same convex ring.

5. The electrostatic probe for early fault detection of heavy-duty gas turbines according to claim 4, characterized in that, The probe includes: a disk, reinforcing ribs, and a needle tube; One end of the needle is installed inside the first shielding cover via a disc, and the lower surface of the disc abuts against the upper panel of the end of the first shielding cover. The other end of the needle extends out of the first shielding cover; The reinforcing rib connects the side wall of the needle tube to the lower surface of the disc.

6. The electrostatic probe for early fault detection of heavy-duty gas turbines according to claim 5, characterized in that, The second insulating cover is cylindrical in shape and is made of aluminum oxide. The inner cavity of the second insulating cover contains the connecting block.

7. The electrostatic probe for early fault detection of heavy-duty gas turbines according to claim 6, characterized in that, The connecting block is made of copper.

8. A method for using an electrostatic probe for early fault detection in heavy-duty gas turbines, characterized in that, The electrostatic probe for early fault detection of heavy-duty gas turbines as described in claim 7 includes: S1. At least four electrostatic probes for early fault detection of heavy-duty gas turbines are evenly arranged on the inner wall of the metal gas pipeline, wherein each electrostatic probe for early fault detection of heavy-duty gas turbines is connected to an electrostatic detection terminal. S2. When particles are present in the metal gas pipeline, the electrostatic probe for early fault detection of heavy-duty gas turbines captures the particles. The time-domain electrostatic signal generated by the probe sensing in each electrostatic probe for early fault detection of heavy-duty gas turbines is transmitted to the electrostatic detection terminal for signal fusion and enhancement processing to obtain an enhanced signal dataset. S3. Based on the enhanced signal dataset, perform charge fitting and velocity linear fitting respectively to obtain the particle charge linear fitting formula and the particle velocity linear fitting formula.

9. The method of using the electrostatic probe for early fault detection of heavy-duty gas turbines according to claim 8, characterized in that, The time-domain electrostatic signal generated by the probe sensing within each electrostatic probe in S2 for early fault detection of heavy-duty gas turbines is transmitted to the electrostatic detection terminal for signal fusion and enhancement processing, resulting in an enhanced signal dataset including: The average value of the electrostatic signals detected by all probes is obtained by averaging the values ​​of all electrostatic probe signals. The standard deviation and bias of the signal are calculated based on the average value of all electrostatic probe signals. The enhanced signal dataset is obtained based on the standard deviation and bias of the signal.

10. The method of using the electrostatic probe for early fault detection of heavy-duty gas turbines according to claim 9, characterized in that, The formula for the standard deviation of the signal is formula (1): ；（1） s1 is the standard deviation of the signal, and N is the number of all electrostatic probes; The average value of all electrostatic probe signals. The electrostatic signal detected by the i-th electrostatic probe; ；（2） s2 represents the signal deviation, and j and k are the probe numbers. Let be the potential of the j-th probe. Let be the potential of the k-th probe; The calculation formula for the data in the enhanced signal dataset is formula (3): ；（3） The linear regression data represents the data within the enhanced signal dataset, i.e., the data from the probe array; a and b are the regression coefficients determined through simulation, where a = 0.384 and b = -3.

034. =0.217.

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