A Micromagnetic Detection Process for Micron-level Leakage of Heat Exchangers in High-end Equipment

Abstract

The present invention discloses a micron-level magnetic flux leakage detection process for heat exchangers of high-end equipment, which relates to the technical field of non-destructive testing of heat exchanger tubes. The magnetic flux leakage detection process includes the following steps: S100, detection probe unit: Using the probe housing for positioning, arranging high-precision TMR high-sensitivity sensors on the corresponding detection surface, encapsulating them after being used as the detection unit, and equipping two types of probes, namely probe A and probe B, to respectively detect the tangential component HPX and the normal component HPY of the magnetic flux leakage field strength, and performing a scan on the arc surface of the workpiece. By adopting high-precision TMR high-sensitivity sensors and equipping two types of probes for detecting the tangential component HPX and the normal component HPY of the magnetic flux leakage field strength, this process can accurately capture the weak magnetic flux leakage signals generated by micron-level defects, realizing the efficient detection of micro-cracks and hole defects on the inner and outer walls of the heat exchanger.

Description

Technical Field

[0001] The present invention relates to the technical field of non-destructive testing of heat exchanger tubes, and particularly to a micron-level magnetic flux leakage detection process for heat exchangers of high-end equipment. Background Art

[0002] With the continuous progress and development of industrial technologies, heat exchangers, as indispensable key components in many industrial fields, their performance and reliability directly affect the operating efficiency and safety of the entire equipment. After long-term operation, heat exchangers may develop defects such as micro-cracks or holes due to material fatigue, corrosion, etc. If these defects are not discovered and processed in a timely manner, they will gradually expand, ultimately leading to serious safety accidents and posing a huge threat to production safety and personnel health. Therefore, it is particularly important to perform efficient and accurate defect detection on heat exchangers.

[0003] However, most of the heat exchanger detection technologies commonly used in the market at present rely on macroscopic magnetic particle testing and ultrasonic testing, and have limited detection effects on micron-level fine defects, and cannot effectively detect the bending area of C-shaped tubes. Especially when the curvature of the detection part is large, it is difficult for traditional probes to closely fit the surface of the workpiece, resulting in the existence of detection blind spots. During the detection process, the recognition and alarm mechanism for abnormal waveforms is not perfect enough, and situations of missed detection and false alarms are likely to occur, affecting the accuracy and reliability of the detection results. In addition, conventional non-destructive testing methods require special magnetization devices, have limited ability to diagnose early damage of ferromagnetic materials, and are difficult to detect the positions of micro-defects and stress concentrations.

[0004] In summary, there are many deficiencies in the existing technology for detecting micron-level defects in heat exchangers, and it is difficult to meet the high requirements of modern high-end equipment for detection accuracy, efficiency, and intelligent level. Therefore, developing a new magnetic flux leakage detection process that can efficiently and accurately detect micron-level defects in heat exchangers, and has strong adaptability, high automation, strong data processing ability, and visual display of detection results, is of great significance for improving the heat exchanger detection technology level and ensuring industrial production safety and efficiency. Summary of the Invention

[0005] The purpose of the present invention is to make up for the deficiencies of the existing technology, and provide a micron-level magnetic flux leakage detection process for heat exchangers of high-end equipment. It can accurately detect the tangential component HPX and normal component HPY of the magnetic flux leakage field intensity by using probe housing positioning and equipped with high-precision TMR high-sensitivity sensors. Through the coordinated use of probe A and probe B, and the precise analysis of the signal acquisition and processing unit and the terminal acquisition and processing unit, high-precision detection of defects on the inner and outer walls of the heat exchange tube can be achieved.

[0006] To solve the above technical problems, the present invention provides the following technical solution: A micron-level magnetic flux leakage detection process for a heat exchanger of high-end equipment, the magnetic flux leakage detection process comprising the following steps:

[0007] S100, Detection probe unit: Using a probe shell for positioning, arranging high-precision TMR high-sensitivity sensors on the corresponding detection surface, encapsulating them as a detection unit after that, and equipping two types of probes, namely probe A and probe B, to respectively detect the tangential component HPX and the normal component HPY of the magnetic flux leakage field strength, and performing a scan on the arc surface of the workpiece;

[0008] S200, Adapter box connection unit: Customizing an adapter box using aluminum, which is equipped with multiple adapter pin inputs and a single DB37 socket output, to connect the signals of the probe and the signal acquisition and processing unit, and solve the matching of the sockets. Insert the probe into the corresponding socket of the adapter box, and connect it to the signal acquisition and processing unit through a DB37 patch cord;

[0009] S300, Signal acquisition and processing unit: Amplifying and converting the signals transmitted by the probe, collecting and discriminating them by a computer, with an aviation linear power supply, a differential amplifier, a signal collector, an alarm module, and a buzzer built-in, and converting the processed signals into a form that can be received by the terminal processing unit;

[0010] S400, Terminal acquisition and processing unit: Providing multiple device options, namely a portable computer, a desktop computer, and an industrial computer, receiving the signals sent by the signal acquisition and processing unit, processing them and forming the final detection result, and the detection result can be displayed, stored, and printed;

[0011] S500, Workpiece magnetization and detection unit: Magnetizing the heat exchange tube to generate a magnetic flux leakage field at the defect position, completing the magnetization process by energizing a through-type coil, attaching the probe to the outer wall of the heat exchange tube, and performing a scan along the curved surface path to detect the defects on the inner and outer walls of the heat exchange tube;

[0012] S600, Demagnetization and subsequent processing unit: After the detection is completed, putting the heat exchange tube into a demagnetizer to complete demagnetization to avoid interference with subsequent processes, and performing subsequent processing according to the detection result, that is, repairing and replacing defective heat exchange tubes.

[0013] Furthermore, the S100 detection probe unit is positioned by a probe shell, and a high-precision TMR high-sensitivity sensor is arranged on the corresponding detection surface, which is then packaged as a detection unit and equipped with two probes, namely probe A and probe B. Probe A is used to detect the tangential component HPX of the leakage magnetic field strength, and probe B is used to detect the normal component HPY of the leakage magnetic field strength. The specific method for detecting the tangential component HPX and the normal component HPY of the leakage magnetic field strength is as follows: when a ferromagnetic component in a geomagnetic magnetic field environment is subjected to an external load, a fixed node of a magnetic domain with magnetostrictive properties is generated in a stress concentration area, a magnetic pole is generated, and a demagnetizing field is formed, thereby minimizing the magnetic permeability of the ferromagnetic metal here and forming a leakage magnetic field on the metal surface. This irreversible change in the magnetic state still "memorizes" the location of microscopic defects and stress concentration after the working load is eliminated, namely, the "magnetic memory effect". The tangential component HPX of the leakage magnetic field strength has a maximum value, while the normal component HPY changes its sign and has a zero value. Therefore, the signals in the HPX and HPY directions are detected by probe A and probe B respectively, so as to complete the diagnosis of defects and stress concentration on the component.

[0014] Furthermore, the S100 performs centralized diagnosis and detection of signals in the HPX and HPY directions through probes A and B respectively, fits the probes on the surface wall of the arc surface of the workpiece, and manually scans along the arc surface path. The shape of the probe matches the arc surface of the workpiece and fits tightly on the surface. The position of the abnormal waveform is repeatedly scanned and determined. During the scanning process, the sensor collects leakage magnetic field data in real time, and converts the analog signal into a digital signal through a signal conversion circuit. The collected data is preliminarily processed, and the processed data is sent to the adapter box connection unit for further analysis to identify abnormal changes in the leakage magnetic field.

[0015] Furthermore, the S200 adapter box connection unit uses an aluminum customized adapter box with multiple adapter pin inputs and a single DB37 socket output. The adapter pin receives the signal from the probe, and each adapter pin input corresponds to a probe. The DB37 socket integrates the probe signals collected by the adapter box. The tangential component HPX and normal component HPY signals of the leakage magnetic field strength detected by probe A and probe B are transmitted to the adapter box through the adapter pin input. The adapter box performs preliminary sorting and integration of these signals, so that the signals of multiple probes can be output in an orderly manner through a single DB37 socket, and output to the signal acquisition and processing unit through the socket.

[0016] Furthermore, the S300 signal acquisition and processing unit amplifies and converts the signal from the probe, and the computer collects and identifies it. The unit has a built-in aviation linear power supply, a differential amplifier, a signal collector, an alarm module, and a buzzer, and its contents include:

[0017] The aviation linear power supply provides stable power support for the entire unit, enabling each component to operate normally;

[0018] The differential amplifier precisely amplifies the weak signals received from the adapter box, enhancing the signal strength. The amplified signals are used for subsequent processing and analysis;

[0019] The signal collector real-time collects the amplified signals and converts them into digital signals for computer processing;

[0020] When the alarm module detects abnormal signals, it triggers an alarm to alert the operator;

[0021] The buzzer cooperates with the alarm module to emit a sound alarm, reminding the operator to conduct further inspections.

[0022] Furthermore, the S300 receives signals from the adapter box through a DB37 socket. These signals are the tangential component HPX and normal component HPY signals of the leakage magnetic field intensity detected by probe A and probe B. It amplifies and converts these signals, and the processed signals are converted into the form received by the terminal processing unit, namely digital signals and data packets in a specific format, and the signals are sent to the terminal acquisition and processing unit to prepare for subsequent analysis and processing.

[0023] Furthermore, the S400 receives digital signals and data packets in a specific format from the S300 signal acquisition and processing unit, deeply analyzes, processes, and displays these data, and finally generates a detection result report. This unit supports multiple device selections, namely portable machines, desktop computers, and industrial computers, to meet the detection requirements in different scenarios. The specific steps are as follows:

[0024] S401, Signal reception: The terminal acquisition and processing unit receives digital signals and data packets in a specific format from the signal acquisition and processing unit;

[0025] S402, Data processing: Analyze and process the received signals, identify the characteristic information in the signals and the abnormal changes in the leakage magnetic field, and judge whether there are defects in the heat exchange tubes and the type and location of the defects;

[0026] S403, Result display: Display the processed detection results in a visual manner, present the image of the heat exchange tube, and mark the location and information of the defects;

[0027] S404, Data storage and printing: The detection result report is stored in the computer hard disk and cloud storage for subsequent analysis and use. It also provides a printing function, and the operator prints the detection result report as the basis for detection records and processing.

[0028] Furthermore, when the S500 workpiece magnetization and detection unit completes the detection result report in the S400 terminal acquisition and processing unit and confirms that there are defects in the heat exchange tubes and further verification is required, it prepares the through-type coil and magnetization power supply, places the heat exchange tubes to be detected in the magnetization device, energizes the through-type coil to generate a magnetic field, and this magnetic field acts on the heat exchange tubes, causing leakage magnetic fields to be generated at the positions of internal defects due to the magnetostrictive effect. During the magnetization process, the magnitude and time of the current are controlled. After magnetization is completed, the S100 detection probe is started for scanning. Probe A and probe B respectively detect the tangential component HPX and the normal component HPY of the leakage magnetic field intensity, and the signals are transmitted to the S300 signal acquisition and processing unit through the S200 adapter box connection unit. After the S300 amplifies and converts the signals, they are received again by the S400 terminal acquisition and processing unit for secondary analysis and confirmation to verify the magnetization effect and the accurate position of the defects. According to the secondary analysis results, a detailed magnetization detection report is generated and compared with the initial detection results. If it is confirmed that the defects exist and the positions are accurate, demagnetization is performed.

[0029] Furthermore, after the S600 confirms that there are defects in the heat exchange tubes and the positions are accurate, it takes out the heat exchange tubes from the detection device and immediately puts them into the demagnetizer. The demagnetizer uses the AC demagnetization method and the DC demagnetization method to eliminate the residual magnetism on the surface and inside of the heat exchange tubes by generating a gradually decaying magnetic field. During the demagnetization process, the magnitude, direction, and decay rate of the demagnetization current are controlled. After demagnetization is completed, a magnetometer is used to detect the residual magnetism level on the surface of the heat exchange tubes. According to the generated final detection result report, processing decisions are made for the heat exchange tubes, including marking and recording for heat exchange tubes with minor defects, and repairing and replacing for heat exchange tubes with serious defects that affect heat exchange efficiency and pose safety hazards. All detection results, demagnetization records, repair and replacement processes, and quality inspection results are recorded to form a complete detection and repair file for reference in the next detection and quality traceability.

[0030] Furthermore, for the bending area of the C-type tube in this magnetic flux leakage detection process, the C-type tube is detected by manual scanning with a probe. After magnetization from the magnetizer, the probe is attached to scan the detection surface. For abnormal waveforms that appear during the detection process, the alarm module and buzzer of the signal acquisition and processing unit give alarm prompts, and demagnetization is performed for normal detected parts.

[0031] Compared with the prior art, the micron-level magnetic flux leakage detection process for high-end equipment heat exchangers has the following beneficial effects:

[0032] I. The present invention adopts a high-precision TMR high-sensitivity sensor and is equipped with two types of probes for detecting the tangential component HPX and the normal component HPY of the leakage magnetic field intensity. This process can accurately capture the weak leakage magnetic field signals generated by micron-level defects, realizing the efficient detection of micro-cracks and hole defects on the inner and outer walls of heat exchangers. In addition, by using the probe shell positioning technology, the probes are closely attached to the arc surface of the workpiece, effectively reducing the detection blind area and improving the detection coverage rate. This series of innovative designs not only ensures the accuracy of the detection results, but also significantly shortens the detection cycle and reduces the detection cost, providing a strong guarantee for the safe operation of high-end equipment.

[0033] II. Through the collaborative work of the connection unit of the adapter box and the signal acquisition and processing unit, the present invention can transmit and process signals quickly and stably. The terminal acquisition and processing unit provides a variety of device options to meet the detection needs in different scenarios. The detection results can be displayed, stored, and printed, facilitating the operators to record and analyze. When abnormal waveforms are detected, the alarm module and the buzzer will give alarm prompts in a timely manner to ensure that the operators can discover problems in time. After the detection is completed, the heat exchange tubes are demagnetized by a demagnetizer to avoid interference with subsequent processes. For defective heat exchange tubes, timely repair and replacement can be carried out according to the detection results, ensuring the quality and reliability of the heat exchange tubes.

[0034] Other advantages, objectives, and features of the present invention will be described to some extent in the subsequent specification, and to some extent, will be obvious to those skilled in the art based on the study of the following text, or can be taught from the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0036] Figure 1 It is an operation flow chart of a micron-level magnetic flux leakage detection process for a heat exchanger of high-end equipment;

[0037] Figure 2 It is a working principle diagram of the magnetic memory method;

[0038] Figure 3 It is a layout plan diagram of equipment detection;

[0039] Figure 4 It is a magnetic field change diagram induced by the TMR high-sensitivity sensor;

[0040] Figure 5 It is a structural diagram of the device.

[0041] In the figure: 1. Magnetizer; 2. Demagnetizer; 3. Acquisition and processing unit; 4. Detection station. Specific implementation mode

[0042] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0043] Embodiment 1

[0044] This embodiment provides a specific implementation process of a micron-level magnetic flux leakage detection process for a high-end equipment heat exchanger. As Figure 1 shown, by analyzing the natural magnetic flux leakage field generated at the stress concentration of ferromagnetic materials, accurate detection of defects on the inner and outer walls of the heat exchange tube is achieved, improving the detection accuracy and efficiency, meeting the detection requirements of high-end equipment heat exchangers, and being of great significance for improving the heat exchanger detection technology level and ensuring industrial production safety and efficiency.

[0045] First, enter the detection probe unit stage (S100). According to the specific dimensions of the heat exchange tube, a probe housing is made to ensure that the probe can perfectly fit the surface of the heat exchange tube. A high-precision TMR high-sensitivity sensor is installed inside the probe housing, and probes A and B are encapsulated. As Figure 2 shown, these two probes are respectively used to detect the tangential component HPX and the normal component HPY of the magnetic flux leakage field intensity. In order to ensure the close contact between the probe and the surface of the heat exchange tube, a manual adjustment method is used to adjust the position of the probe to ensure its perfect fit with the surface of the heat exchange tube. After assembly, preliminary debugging is carried out to verify whether the response of the sensor is sensitive and whether probes A and B can correctly detect the preset magnetic field changes. As Figure 3 shown, start the probe for preliminary scanning. The sensor collects magnetic flux leakage data in real time, converts the analog signal into a digital signal through a signal conversion circuit, and captures weak magnetic flux leakage signals to reduce the influence of external interference on the detection results.

[0046] Then, enter the adapter box connection unit stage (S200). Customize an adapter box using aluminum material. This adapter box is equipped with multiple adapter pin inputs and one DB37 socket output. Connect probe A and probe B to the corresponding pins of the adapter box respectively, and connect the adapter box to the signal acquisition and processing unit 3 through a DB37 patch cord. Before connection, check the contact condition of each pin to ensure the stability and reliability of signal transmission. Test the function of the adapter box, simulate signal input, and verify whether the adapter box can correctly integrate the signal and output it through the DB37 socket by observing the reaction of the signal acquisition and processing unit 3.

[0047] Subsequently, enter the signal acquisition and processing unit stage (S300). Amplify and convert the signals transmitted by the probes. Install an aviation linear power supply to provide stable power supply. Connect the differential amplifier to the signal collector so as to amplify and convert the weak signals from the probes. Set up an alarm module and a buzzer so as to promptly remind the operator when abnormal signals are detected. After the hardware installation is completed, perform software configuration to ensure that the computer can correctly read and process the data transmitted by the signal acquisition and processing unit 3. Also, calibrate through standard samples to ensure the overall accuracy of the system.

[0048] Secondly, enter the terminal acquisition and processing unit stage (S400). Receive the digital signals and data packets in a specific format from the signal acquisition and processing unit 3, deeply analyze and process these data, identify the characteristic information in the signals and the abnormal changes of the leakage magnetic field, so as to judge whether there are defects in the heat exchange tubes and the type and location of the defects. Display the processed detection results in a visual way, present the image of the heat exchange tubes, and mark the location and information of the defects. Store the detection result report on the computer hard disk and upload it to the cloud for subsequent analysis.

[0049] Next, enter the workpiece magnetization and detection unit stage (S500). When the terminal acquisition and processing unit 3 confirms that there are defects in the heat exchange tubes and further verification is needed, as Figure 4 shown, place the heat exchange tubes to be detected in the magnetization device. Pass an electric current through the through-type coil to generate a magnetic field, so that leakage magnetic fields are generated at the positions of the internal defects of the heat exchange tubes due to the magnetostrictive effect. After magnetization is completed, start the detection probe again for scanning. Detect the tangential component HPX and the normal component HPY of the leakage magnetic field intensity through probe A and probe B respectively. The collected signals are amplified and converted by the adapter box and the signal acquisition and processing unit 3, and then subjected to secondary analysis and confirmation by the terminal acquisition and processing unit 3, improving the accuracy of the detection results. Evaluate whether there are defects and their types on the inner and outer walls of the heat exchange tubes according to the signal changes, ensuring the accurate positioning of the defect positions.

[0050] Finally, enter the demagnetization and subsequent processing unit stage (S600). Once a defect in the heat exchange tube is confirmed, it is immediately removed from the detection device and placed into the demagnetizer 2 for demagnetization. The demagnetizer 2 uses the AC demagnetization method to eliminate the residual magnetism on the surface and inside of the heat exchange tube through a gradually decaying magnetic field. During the demagnetization process, the magnitude, direction, and decay rate of the demagnetizing current are strictly controlled to ensure complete removal of the residual magnetism. After demagnetization, a magnetometer is used to detect the residual magnetism level on the surface of the heat exchange tube. According to the final test result report, the heat exchange tubes with minor defects are marked and recorded, while the heat exchange tubes with serious defects, affecting heat exchange efficiency and posing safety hazards, are repaired or replaced. All the detection records, demagnetization records, repair and replacement processes, and quality inspection results are organized into files for subsequent reference and quality traceability.

[0051] In summary, a micron-level magnetic flux leakage detection process for high-end equipment heat exchangers provided by this embodiment realizes the automatic amplification, conversion, acquisition, analysis, and processing of detection signals through the collaborative work of each unit, improves the detection efficiency, supports multiple device selections, and is convenient for flexible application in different scenarios, providing great convenience for detection records and subsequent processing, and ensuring the safety and reliability of the detection process.

[0052] Embodiment 2

[0053] This embodiment provides a micron-level magnetic flux leakage detection process for high-end equipment heat exchangers. For the bending area of the C-shaped tube of an aviation instrument, high-precision TMR high-sensitivity sensors are arranged on the detection surface and encapsulated into a detection unit, equipped with probe A and probe B, which are respectively used to detect the tangential component HPX and the normal component HPY of the magnetic flux leakage field strength, ensuring that the probes are firmly installed and closely attached to the detection surface to accurately detect the magnetic flux leakage field signal.

[0054] In specific implementation, as Figure 5 shown, a probe shell matching the shape of the C-shaped tube is selected. The inner radius of the C-shaped tube is 18.6 mm and the wall thickness is 3.5 mm. The main purpose is to detect corrosion and cracks on the inner wall of the bending part of the C-shaped tube. High-precision TMR high-sensitivity sensors are arranged on the corresponding detection surface and encapsulated into a detection unit, and equipped with probe A and probe B, which are respectively used to detect the tangential component HPX and the normal component HPY of the magnetic flux leakage field strength. An aluminum custom-made adapter box is used, equipped with 4 six-core adapter pins for input and a single DB37 socket for output. As Figure 3 shown, prepare the signal acquisition and processing unit 3, which is built-in with an aviation linear power supply, a differential amplifier, a signal collector, an alarm module, and a buzzer. Select the terminal acquisition and processing unit 3, including a portable computer, a desktop computer, and an industrial computer.

[0055] Connect the detection probe to the adapter box, insert probe A and probe B into the corresponding sockets (1, 2, 3, 4) of the adapter box through the detection station 4, ensure that each adapter pin input is connected to a corresponding probe, connect the adapter box to the signal acquisition and processing unit 3 through the DB37 adapter cable, when the probe scans the arc surface of the C-type tube, the sensor collects leakage magnetic field data in real time, and converts the analog signal into a digital signal through the signal conversion circuit, the adapter box preliminarily organizes and integrates the probe signal, and outputs the signal to the signal acquisition and processing unit 3 through the DB37 socket, the signal acquisition and processing unit 3 amplifies and converts the signal, and the computer performs The signal is collected and identified. When the alarm module detects an abnormal signal, the buzzer will sound an alarm. The processed signal is converted into a form received by the terminal processing unit, that is, a digital signal and a data packet in a specific format, and sent to the terminal collection processing unit 3. The terminal collection processing unit 3 receives the digital signal and data packet from the signal collection processing unit 3, analyzes and processes the signal, identifies the characteristic information in the signal and the abnormal change of the leakage magnetic field, determines whether the C-type tube has defects and the type and location of the defects, and displays the processed detection results in a visual way, presenting an image of the C-type tube and marking the location and information of the defects.

[0056] The test result report is stored in the computer hard disk and cloud storage, and a printing function is provided. The test result report is printed out as the basis for test records and processing. The C-type tube is placed in the magnetizer 1 for magnetization, and the through-type coil is energized to generate a leakage magnetic field at the defect position. After magnetization, the probe is attached to the surface wall of the C-type tube, and the C-shaped curved surface path is manually scanned slowly. The probe detects the upper half of the C-type tube in the forward direction and the lower half of the C-type tube in the reverse direction. The position with abnormal waveform is repeatedly scanned to determine. If an abnormal waveform appears during the detection process, the alarm module and buzzer of the signal acquisition and processing unit 3 will give an alarm prompt.

[0057] After the detection is completed, the C-tube is placed in the demagnetizer 2 to complete demagnetization. The AC demagnetization method and the DC demagnetization method are used to eliminate the residual magnetism on the surface and inside of the C-tube by generating a gradually decaying magnetic field. During the demagnetization process, the size, direction and decay speed of the demagnetization current are controlled. After the demagnetization is completed, a magnetometer is used to detect the residual magnetism level on the surface of the C-tube. According to the generated final test result report, a treatment decision is made for the C-tube. For C-tubes with slight defects, they are marked and recorded; for C-tubes with serious defects that affect heat exchange efficiency and pose safety hazards, they are repaired and replaced. All test results, demagnetization records, repair and replacement processes, and quality inspection results are recorded to form a complete test and maintenance file for reference and quality traceability for the next test.

[0058] In summary, the detection process of this embodiment is that the workpiece is magnetized first, then detected, and finally demagnetized. The sensing scheme is magnetic flux leakage + magnetic disturbance detection. After the C-shaped pipe fitting is magnetized in the magnetizer 1, the probe is attached to the outer wall of the C-shaped pipe and scanned along the C-shaped curved surface path to detect the defects on the C-shaped surface. After the detection is completed, the C-shaped pipe is put into the demagnetizer 2 to complete demagnetization, and all detection results, demagnetization records, repair and replacement processes, and quality inspection results are recorded to form a complete detection and repair file for reference in the next detection and quality traceability.

[0059] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present invention. Any reference signs in the claims should not be regarded as limiting the claims involved.

Claims

1. A micron-level magnetic flux leakage detection process for heat exchangers of high-end equipment, characterized in that, The magnetic flux leakage detection process includes the following steps: S100, Detection probe unit: Positioned by a probe housing, high-precision TMR high-sensitivity sensors are arranged on the corresponding detection surface. After being encapsulated as a detection unit, two types of probes are equipped, namely probe A and probe B, which are used to detect the tangential component HPX and the normal component HPY of the magnetic flux leakage intensity respectively, and are scanned on the arc surface of the workpiece. Among them, in S100, the detection probe unit is positioned by a probe housing, high-precision TMR high-sensitivity sensors are arranged on the corresponding detection surface. After being encapsulated as a detection unit, two types of probes are equipped, namely probe A and probe B. Probe A is used to detect the tangential component HPX of the magnetic flux leakage intensity, and probe B is used to detect the normal component HPY of the magnetic flux leakage intensity. For detecting the tangential component HPX and the normal component HPY of the magnetic flux leakage intensity, the specific method is as follows: When a ferromagnetic component in the geomagnetic field environment is subjected to an external load, fixed nodes of magnetic domains with magnetostrictive properties are generated in the stress concentration area, magnetic poles are generated, and a demagnetizing field is formed, so that the magnetic permeability of the ferromagnetic metal here is the smallest, and a magnetic flux leakage field is formed on the metal surface. This irreversible change in the magnetic state still retains the "memory" of the position of microscopic defects and stress concentration after the working load is removed, that is, the "magnetic memory effect". The tangential component HPX of the magnetic flux leakage intensity has a maximum value, while the normal component HPY changes sign and has a zero value. Therefore, by detecting the signals in the HPX and HPY directions with probe A and probe B respectively, the diagnosis of defects and stress concentration on the component is completed; S200, Adapter box connection unit: Customize an adapter box using aluminum, which is equipped with multiple adapter pin inputs and a single DB37 socket output to connect the signals of the probe and the signal acquisition and processing unit, and solve the matching of the socket. Insert the probe into the corresponding socket of the adapter box and connect it to the signal acquisition and processing unit through a DB37 transfer wire; S300, Signal acquisition and processing unit: Amplify and convert the signals transmitted by the probe, and collect and discriminate them by a computer. It is built-in with an aviation linear power supply, a differential amplifier, a signal collector, an alarm module, and a buzzer, and converts the processed signals into a form that can be received by the terminal processing unit; S400, Terminal acquisition and processing unit: Provide multiple device options, namely a portable computer, a desktop computer, and an industrial computer. Receive the signals sent by the signal acquisition and processing unit, process them and form the final detection result. The detection result can be displayed, stored, and printed; S500, Workpiece magnetization and detection unit: Magnetize the heat exchange tube to generate a magnetic flux leakage field at the defect position. The magnetization process is completed by passing an electric current through a through-type coil. Fit the probe on the outer wall of the heat exchange tube and scan along the curved surface path to detect the defects on the inner and outer walls of the heat exchange tube; S600, Demagnetization and subsequent processing unit: After the detection is completed, put the heat exchange tube into a demagnetizer to complete demagnetization to avoid interference with subsequent processes. Perform subsequent processing according to the detection result, that is, repair and replace the defective heat exchange tube.

2. The micron-level magnetic flux leakage detection process for the heat exchanger of high-end equipment according to claim 1, characterized in that, The S100 respectively conducts centralized diagnosis and detection of signals in the HPX and HPY directions through probe A and probe B. The probes are attached to the surface of the arc of the workpiece, and manually scanned along the path of the arc surface. The shape of the probes matches the arc surface of the workpiece and is closely attached to the surface. The positions with abnormal waveforms are repeatedly scanned and determined. During the scanning process, the sensor collects the magnetic leakage field data in real time, and converts the analog signal into a digital signal through the signal conversion circuit. The collected data is preliminarily processed, and the processed data is sent to the connection unit of the adapter box for further analysis to identify the abnormal changes in the magnetic leakage field.

3. The micron-level magnetic flux leakage detection process for the heat exchanger of high-end equipment according to claim 1, characterized in that, The S200 connection unit of the adapter box customizes the adapter box using aluminum, which is equipped with multiple adapter pin inputs and a single DB37 socket output. The adapter pins receive the signals from the probes, and each adapter pin input corresponds to connecting a probe. The DB37 socket integrates the probe signals collected by the adapter box. The tangential component HPX and the normal component HPY signals of the magnetic leakage field intensity detected by probe A and probe B are transmitted to the adapter box through the adapter pin inputs. The adapter box preliminarily arranges and integrates these signals, enabling the signals of multiple probes to be output orderly through a single DB37 socket and output to the signal acquisition and processing unit through this socket.

4. The micron-level magnetic flux leakage detection process for a high-end equipment heat exchanger according to claim 1, characterized in that, The S300 signal acquisition and processing unit amplifies and converts the signals transmitted from the probes, and is collected and judged by a computer. This unit is built-in with an aviation linear power supply, a differential amplifier, a signal collector, an alarm module, and a buzzer. Its content includes: The aviation linear power supply provides stable power support for the entire unit, enabling each component to operate normally; The differential amplifier precisely amplifies the weak signals received from the adapter box, enhances the signal intensity, and the amplified signals are used for subsequent processing and analysis; The signal collector collects the amplified signals in real time and converts them into digital signals for the computer to process; When the alarm module detects an abnormal signal, it will trigger an alarm to remind the operator to pay attention; The buzzer cooperates with the alarm module to emit an audible alarm to remind the operator to conduct further inspections.

5. The micron-level magnetic flux leakage detection process for the heat exchanger of high-end equipment according to claim 4, wherein The S300 receives the signals from the adapter box through the DB37 socket. These signals are the tangential component HPX and the normal component HPY signals of the magnetic leakage field intensity detected by probe A and probe B, and amplifies and converts them. The processed signals are converted into the form received by the terminal processing unit, that is, digital signals and data packets in a specific format, and the signals are sent to the terminal acquisition and processing unit to prepare for subsequent analysis and processing.

6. The micron-level magnetic flux leakage detection process for a high-end equipment heat exchanger according to claim 1, characterized in that The S400 receives the digital signals and data packets in a specific format from the S300 signal acquisition and processing unit, deeply analyzes, processes, and displays these data, and finally generates a detection result report. This unit supports multiple device selections, namely portable machines, desktop computers, and industrial computers, to meet the detection requirements in different scenarios. The specific steps are as follows: S401, signal reception: The terminal acquisition and processing unit receives the digital signals and data packets in a specific format from the signal acquisition and processing unit; S402, Data Processing: Analyze and process the received signal, identify the characteristic information in the signal and the abnormal changes in the leakage magnetic field, and determine whether there are defects in the heat exchange tube, as well as the type and location of the defects; S403, Result Display: Display the processed detection results in a visual way, present the image of the heat exchange tube, and mark the location and information of the defects; S404, Data Storage and Printing: The detection result report is stored in the computer hard disk and cloud storage for subsequent analysis and use. A printing function is also provided. The operator prints the detection result report as the basis for detection records and processing.

7. The micron-level magnetic flux leakage detection process for a high-end equipment heat exchanger according to claim 1, characterized in that When the S500 workpiece magnetization and detection unit completes the detection result report in the S400 terminal acquisition and processing unit and confirms that there are defects in the heat exchange tube and further verification is required, it prepares the through-type coil and magnetization power supply, places the heat exchange tube to be detected in the magnetization device, and generates a magnetic field by energizing the through-type coil. This magnetic field acts on the heat exchange tube, causing a leakage magnetic field to be generated at the internal defect location due to the magnetostrictive effect. During the magnetization process, the magnitude and time of the current are controlled. After magnetization is completed, the S100 detection probe is started for scanning. Probe A and probe B respectively detect the tangential component HPX and the normal component HPY of the leakage magnetic field intensity. The signal is transmitted to the S300 signal acquisition and processing unit through the S200 junction box connection unit. After the S300 amplifies and converts the signal, it is received again by the S400 terminal acquisition and processing unit for secondary analysis and confirmation to verify the magnetization effect and the accurate location of the defect. According to the secondary analysis result, a detailed magnetization detection report is generated and compared with the initial detection result. If it is confirmed that the defect exists and the location is accurate, demagnetization is performed.

8. The micron-level magnetic flux leakage detection process for the heat exchanger of high-end equipment according to claim 7, characterized in that, After the S600 confirms that there are defects in the heat exchange tube and the location is accurate, the heat exchange tube is taken out of the detection device and immediately placed in a demagnetizer. The demagnetizer uses the AC demagnetization method and the DC demagnetization method to eliminate the residual magnetism on the surface and inside of the heat exchange tube by generating a gradually decaying magnetic field. During the demagnetization process, the magnitude, direction, and decay rate of the demagnetization current are controlled. After demagnetization is completed, a magnetometer is used to detect the residual magnetism level on the surface of the heat exchange tube. According to the generated final detection result report, a processing decision is made for the heat exchange tube, including marking and recording for slightly defective heat exchange tubes, and repairing and replacing for severely defective heat exchange tubes that affect heat exchange efficiency and pose safety hazards. All detection results, demagnetization records, repair and replacement processes, and quality inspection results are recorded to form a complete detection and repair file for reference in the next detection and quality traceability.

9. The micron-level magnetic flux leakage detection process for a high-end equipment heat exchanger according to claim 1, characterized in that, For the bending area of the C-type tube in the magnetic flux leakage detection process, the C-type tube is detected by manual scanning with a probe. After being magnetized from the magnetizer, the probe is attached to the scanning surface for detection. For abnormal waveforms that appear during the detection process, the alarm module and buzzer of the signal acquisition and processing unit give alarm prompts. For normal detected parts, demagnetization is performed.

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