Micron-scale magnetic flux leakage detection process for high-end equipment heat exchanger

Abstract

The invention discloses a micron-sized magnetic flux leakage detection process for a high-end equipment heat exchanger, and relates to the technical field of nondestructive testing of heat exchange tubes of heat exchangers, the magnetic flux leakage detection process comprises the following steps: S100, detecting a probe unit: positioning by adopting a probe shell, arranging a high-precision TMR high-sensitivity sensor on a corresponding detection surface, and packaging after serving as a detection unit, according to the method, a TMR high-sensitivity sensor with high precision is adopted, two probes, namely, a probe A and a probe B, are arranged and are used for detecting a tangential component HPX and a normal component HPY of the leakage magnetic field intensity respectively, and scanning is carried out on the arc surface of a workpiece. The high-precision TMR high-sensitivity sensor is adopted, and the two probes for detecting the tangential component HPX and the normal component HPY of the leakage magnetic field intensity are arranged; the process can accurately capture weak leakage magnetic field signals generated by micron-sized defects, and realizes efficient detection of micro crack and hole defects on the inner and outer walls of the heat exchanger.

Description

Technical Field

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

[0002] With the continuous advancement and development of industrial technology, heat exchangers, as indispensable key components in many industrial fields, have a direct impact on the operating efficiency and safety of the entire equipment due to their performance and reliability. After a long period of operation, heat exchangers may have defects such as tiny cracks or holes due to material fatigue, corrosion, etc. If these defects are not discovered and handled in time, they will gradually expand and eventually lead to serious safety accidents, posing a huge threat to production safety and personnel health. Therefore, efficient and accurate defect detection of heat exchangers is particularly important.

[0003] However, the heat exchanger inspection technologies commonly used in the market currently mostly rely on macroscopic magnetic particle inspection and ultrasonic inspection, which have limited effects on the detection of subtle defects at the micron level and cannot achieve effective inspection of the bending area of ​​the C-tube. Especially when the curvature of the inspection part is large, it is difficult for the traditional probe to fit tightly against the surface of the workpiece, resulting in the existence of a blind spot in the inspection. During the inspection process, the recognition and alarm mechanism for abnormal waveforms is not perfect, which is prone to missed inspections and false alarms, affecting the accuracy and reliability of the inspection results. In addition, conventional non-destructive testing methods require special magnetization devices, which have limited ability to diagnose early damage to ferromagnetic materials and are difficult to detect microscopic defects and stress concentration locations.

[0004] In summary, the existing technology has many shortcomings in the detection of 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 intelligence. Therefore, it is necessary to develop a new magnetic leakage detection process that can efficiently and accurately detect micron-level defects in heat exchangers, and has strong adaptability, high degree of automation, strong data processing capabilities, and visual display of detection results. It is of great significance to improve the level of heat exchanger detection technology and ensure industrial production safety and efficiency. Summary of the invention

[0005] The purpose of the present invention is to make up for the shortcomings of the prior art and to provide a micron-level magnetic leakage detection process for high-end equipment heat exchangers. It can accurately detect the tangential component HPX and the normal component HPY of the leakage magnetic field intensity by adopting the positioning of the probe shell and being equipped with a high-precision TMR high-sensitivity sensor. 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, it can achieve high-precision detection of defects on the inner and outer walls of the heat exchange tubes.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions: a micron-level magnetic flux leakage detection process for a high-end equipment heat exchanger, the magnetic flux leakage detection process comprising the following steps: S100, detection probe unit: adopts probe shell positioning, arranges high-precision TMR high-sensitivity sensor on the corresponding detection surface, and packages it as a detection unit. It is equipped with two probes, namely probe A and probe B, which respectively detect the tangential component HPX and normal component HPY of the leakage magnetic field intensity, and scan the arc surface of the workpiece; S200, adapter box connection unit: A custom adapter box made of aluminum is equipped with multiple adapter pin inputs and a single DB37 socket output to connect the probe to the signal acquisition and processing unit and solve the matching of the sockets. The probe is inserted into the corresponding socket of the adapter box and connected to the signal acquisition and processing unit through the DB37 adapter cable. S300, signal acquisition and processing unit: amplifies and converts the signal from the probe, and the computer collects and identifies it. It has built-in aviation linear power supply, differential amplifier, signal collector, alarm module, buzzer, and converts the processed signal into a form that can be received by the terminal processing unit; S400, terminal acquisition and processing unit: provides a variety of equipment options, including portable computers, desktop computers, and industrial computers, which receive signals sent by the signal acquisition and processing unit, process them and form the final test results, which can be displayed, stored, and printed; S500, workpiece magnetization and detection unit: magnetize the heat exchange tube to generate a leakage magnetic field at the defect location, use a through-type coil to energize to complete the magnetization process, attach the probe to the surface of the heat exchange tube, scan along the curved path, and detect defects on the inner and outer walls of the heat exchange tube; S600, demagnetization and subsequent processing unit: After the inspection is completed, the heat exchange tube is placed in the demagnetizer to complete the demagnetization to avoid interference with subsequent processes. Subsequent processing is carried out according to the inspection results, that is, repairing and replacing defective heat exchange tubes.

[0007] 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.

[0008] 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.

[0009] 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.

[0010] 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 built-in aviation linear power supply, differential amplifier, signal collector, alarm module, buzzer, and its contents include: The aviation linear power supply provides stable power support for the entire unit, allowing each component to operate normally; The differential amplifier accurately amplifies the weak signal received from the adapter box to enhance the signal strength. The amplified signal is used for subsequent processing and analysis. The signal collector collects the amplified signal in real time and converts it into a digital signal for computer processing; When the alarm module detects an abnormal signal, it will trigger an alarm to alert the operator; The buzzer cooperates with the alarm module to sound an alarm to remind the operator to conduct further inspection.

[0011] Furthermore, the S300 receives signals from the adapter box through the DB37 socket. These signals are the tangential component HPX and normal component HPY signals of the leakage magnetic field strength detected by probe A and probe B, and amplifies and converts them. The processed signals are converted into a 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 processing unit to prepare for subsequent analysis and processing.

[0012] Furthermore, the S400 receives digital signals and data packets in a specific format from the S300 signal acquisition and processing unit, performs in-depth analysis, processing and display of these data, and finally generates a test result report. The unit supports a variety of device options, such as portable computers, desktop computers and industrial computers, to meet the testing needs in different scenarios. The specific steps are as follows: S401, signal reception: the terminal acquisition processing unit receives the digital signal and the data packet of a specific format from the signal acquisition processing unit; S402, data processing: analyzing and processing the received signal, identifying the characteristic information in the signal and the abnormal change of the leakage magnetic field, judging whether there is a defect in the heat exchange tube and the type and location of the defect; S403, result display: displaying the processed test results in a visual manner, presenting an image of the heat exchange tube, and marking the location and information of the defects; S404, data storage and printing: The test result report is stored in the computer hard disk and cloud storage for subsequent analysis and use. A printing function is also provided, and the operator prints the test result report as a basis for test records and processing.

[0013] Furthermore, when the S400 terminal acquisition and processing unit completes the inspection result report and confirms that the heat exchange tube has defects and needs further verification, the S500 workpiece magnetization and detection unit prepares a through-type coil and a magnetization power supply, places the heat exchange tube to be inspected in the magnetization device, and generates a magnetic field by energizing the through-type coil. The magnetic field acts on the heat exchange tube, so that the internal defect position generates a leakage magnetic field due to the magnetostrictive effect. During the magnetization process, the current size and time are controlled. After the 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 signal is transmitted to the S300 signal acquisition and processing unit through the S200 adapter box connection unit. After 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 results, a detailed magnetization detection report is generated and compared with the initial detection results. If it is confirmed that the defect exists and the location is accurate, demagnetization is performed.

[0014] Furthermore, after confirming that the heat exchange tube has defects and is accurately positioned, the S600 takes the heat exchange tube out of the detection device and immediately puts it into a demagnetizer. The demagnetizer uses AC demagnetization and DC demagnetization methods 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 size, direction and decay rate 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 heat exchange tube. According to the generated final test result report, a processing decision is made for the heat exchange tube, including marking and recording if there are minor defects in the heat exchange tube, and repairing and replacing if there are serious defects in the heat exchange tube that affect the heat exchange efficiency and pose a safety hazard. 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.

[0015] Furthermore, the leakage magnetic detection process is to manually scan and detect the C-type tube in the bending area through the probe. After magnetization in the magnetizer, the detection surface is scanned by the probe. If abnormal waveforms appear during the detection process, the alarm module and buzzer of the signal acquisition and processing unit will give an alarm prompt, and demagnetize the normal parts.

[0016] Compared with the existing technology, this high-end equipment heat exchanger micron-level magnetic flux leakage detection process has the following beneficial effects: 1. The present invention adopts a high-precision TMR high-sensitivity sensor and is equipped with two 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, and realize efficient detection of tiny cracks and hole defects on the inner and outer walls of the heat exchanger. In addition, the probe shell positioning technology is used to make the probe fit closely to the arc surface of the workpiece, effectively reducing the detection blind area and improving the detection coverage. This series of innovative designs not only ensures the accuracy of the detection results, but also significantly shortens the detection cycle, reduces the detection cost, and provides a strong guarantee for the safe operation of high-end equipment.

[0017] 2. The present invention can quickly and stably transmit and process signals through the coordinated work of the adapter box connection unit and the signal acquisition and processing unit. The terminal acquisition and processing unit provides a variety of equipment options to meet the detection needs in different scenarios. The detection results can be displayed, stored, and printed, which is convenient for operators to record and analyze. When an abnormal waveform is detected, the alarm module and the buzzer will promptly issue an alarm prompt to ensure that the operator can discover the problem in time. After the detection is completed, the heat exchange tube is demagnetized by a demagnetizer to avoid interference with subsequent processes. For defective heat exchange tubes, they can be repaired and replaced in time according to the test results, ensuring the quality and reliability of the heat exchange tubes.

[0018] Other advantages, objectives and features of the present invention will be set forth in part in the following description and, in part, will be apparent to those skilled in the art based on an examination of the following or may be taught from the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0020] Figure 1 This is an operation flow chart of a micron-level magnetic flux leakage detection process for a high-end equipment heat exchanger; Figure 2 This is the working principle diagram of the magnetic memory method; Figure 3 It is a layout diagram for equipment detection; Figure 4 This is the magnetic field change diagram sensed by the TMR high-sensitivity sensor; Figure 5 This is the equipment structure diagram.

[0021] In the figure: 1. magnetizer; 2. demagnetizer; 3. acquisition and processing unit; 4. detection station. DETAILED DESCRIPTION

[0022] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] Example 1

[0024] This embodiment provides a specific implementation process of a micron-level magnetic flux leakage detection process for a high-end equipment heat exchanger. Figure 1 As shown, by analyzing the leakage magnetic field generated by ferromagnetic materials at stress concentration points, accurate detection of defects on the inner and outer walls of heat exchange tubes can be achieved, improving detection accuracy and efficiency, and meeting the detection needs of high-end equipment heat exchangers. This is of great significance for improving the level of heat exchanger detection technology and ensuring industrial production safety and efficiency.

[0025] First, enter the stage of detecting the probe unit (S100), make the probe shell according to the specific size of the heat exchange tube, ensure that the probe can perfectly fit the surface of the heat exchange tube, install a high-precision TMR high-sensitivity sensor inside the probe shell, and package probe A and probe B, such as Figure 2 As shown in the figure, the two probes are used to detect the tangential component HPX and the normal component HPY of the leakage magnetic field intensity. In order to ensure the close contact between the probe and the surface of the heat exchange tube, the position of the probe is adjusted manually to ensure that it is completely in contact with the surface of the heat exchange tube. After the assembly is completed, preliminary debugging is carried out to verify whether the sensor response is sensitive and whether probe A and probe B can correctly detect the preset magnetic field changes, such as Figure 3 As shown, the probe is started for preliminary scanning. The sensor collects leakage magnetic field data in real time, converts analog signals into digital signals through a signal conversion circuit, and captures weak leakage magnetic field signals to reduce the impact of external interference on the detection results.

[0026] Then, enter the adapter box connection unit stage (S200), use aluminum to customize an adapter box, the adapter box is equipped with multiple adapter pin inputs and a DB37 socket output, probe A and probe B are respectively connected to the corresponding pins of the adapter box, and the adapter box is connected to the signal acquisition and processing unit 3 through the DB37 adapter cable. 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.

[0027] Then, the signal acquisition and processing unit stage (S300) is entered to amplify and convert the signal from the probe, install an aviation linear power supply to provide a stable power supply, connect the differential amplifier to the signal collector so that it can amplify and convert the weak signal from the probe, set up an alarm module and a buzzer so that the operator can be reminded in time when an abnormal signal is detected. After the hardware installation is completed, the software is configured to ensure that the computer can correctly read and process the data from the signal acquisition and processing unit 3. It is also calibrated with standard samples to ensure the overall accuracy of the system.

[0028] Secondly, the terminal acquisition processing unit stage (S400) is entered to receive the digital signal and the data packet in a specific format from the signal acquisition processing unit 3, and the data are deeply analyzed and processed to identify the characteristic information in the signal and the abnormal changes in the leakage magnetic field, so as to judge whether there are defects in the heat exchange tube and the type and location of the defect. The processed test results are displayed in a visual way, presenting an image of the heat exchange tube and marking the location and information of the defect. The test result report is stored on the computer hard disk and uploaded to the cloud for subsequent analysis.

[0029] Next, the workpiece magnetization and detection unit stage (S500) is entered. When the terminal acquisition processing unit 3 confirms that the heat exchange tube has defects and needs further verification, such as Figure 4 As shown, the heat exchange tube to be inspected is placed in a magnetizing device, and a magnetic field is generated by energizing the through-type coil, so that the defective position inside the heat exchange tube generates a leakage magnetic field due to the magnetostrictive effect. After the magnetization is completed, the detection probe is started again for scanning, and the tangential component HPX and the normal component HPY of the leakage magnetic field intensity are detected by 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 secondary analyzed and confirmed by the terminal acquisition and processing unit 3, thereby improving the accuracy of the detection results. According to the change of the signal, it is evaluated whether there are defects and their types on the inner and outer walls of the heat exchange tube, thereby ensuring the accurate positioning of the defect position.

[0030] Finally, the demagnetization and subsequent processing unit stage (S600) is entered. Once it is confirmed that the heat exchange tube has defects, it is immediately taken out of the detection device and placed in the demagnetizer 2 for demagnetization. The demagnetizer 2 adopts 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 demagnetization current are strictly controlled to ensure that the residual magnetism is completely removed. After the demagnetization is completed, the residual magnetism level on the surface of the heat exchange tube is detected by a magnetometer. 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 that affect the heat exchange efficiency and have safety hazards are repaired or replaced. All the test records, demagnetization records, repair and replacement processes and quality inspection results are organized into files for subsequent reference and quality traceability.

[0031] To sum up, this embodiment provides a micron-level magnetic leakage detection process for high-end equipment heat exchangers. Through the collaborative work of various units, it realizes the automatic amplification, conversion, collection, analysis and processing of detection signals, improves detection efficiency, supports a variety of equipment options, and facilitates flexible application in different scenarios. It provides great convenience for detection records and subsequent processing, and ensures the safety and reliability of the detection process.

[0032] Example 2

[0033] This embodiment provides a micron-level magnetic flux leakage detection process for a heat exchanger of high-end equipment. For the C-tube bending area of ​​an aviation instrument, a high-precision TMR high-sensitivity sensor is arranged on the detection surface and packaged into a detection unit. It is equipped with probe A and probe B, which are respectively used to detect the tangential component HPX and the normal component HPY of the leakage magnetic field intensity, ensuring that the probe is firmly installed and closely fits the detection surface to accurately detect the leakage magnetic field signal.

[0034] In the specific implementation, Figure 5 As shown in the figure, a probe shell matching the shape of the C-tube is selected. The inner radius of the C-tube is 18.6mm and the wall thickness is 3.5mm. The corrosion and cracks on the inner wall of the C-tube at the bend are mainly detected. A high-precision TMR high-sensitivity sensor is arranged on the corresponding detection surface and packaged into a detection unit. It is equipped with probe A and probe B, which are used to detect the tangential component HPX and the normal component HPY of the leakage magnetic field intensity respectively. A customized adapter box is made of aluminum, equipped with 4 6-core adapter pin inputs and a single DB37 socket output, as shown in the figure. Figure 3 As shown, prepare a signal acquisition processing unit 3 with a built-in aviation linear power supply, a differential amplifier, a signal collector, an alarm module, and a buzzer, and select a terminal acquisition processing unit 3, including a portable computer, a desktop computer, and an industrial computer.

[0035] 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.

[0036] 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.

[0037] 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.

[0038] In summary, the detection process of this embodiment is that the workpiece is first magnetized, detected, and demagnetized. The sensing scheme is leakage magnetic + magnetic disturbance detection. After the C-type pipe is placed in the magnetizer 1 for magnetization, the probe is attached to the surface wall of the C-type pipe and scanned along the C-shaped curved surface path to detect defects on the C-shaped surface. After the detection is completed, the C-type pipe is placed in the demagnetizer 2 to complete demagnetization, and all test results, demagnetization records, repair and replacement processes, and quality inspection results are recorded to form a complete detection and maintenance file for reference and quality traceability for the next detection.

[0039] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

Claims

1. A micron-level magnetic flux leakage detection process for high-end equipment heat exchangers, characterized in that: The magnetic flux leakage detection process includes the following steps: S100, detection probe unit: adopts probe shell positioning, arranges high-precision TMR high-sensitivity sensor on the corresponding detection surface, and packages it as a detection unit. It is equipped with two probes, namely probe A and probe B, which respectively detect the tangential component HPX and normal component HPY of the leakage magnetic field intensity, and scan the arc surface of the workpiece; S200, adapter box connection unit: A custom adapter box made of aluminum is equipped with multiple adapter pin inputs and a single DB37 socket output to connect the probe to the signal acquisition and processing unit and solve the matching of the sockets. The probe is inserted into the corresponding socket of the adapter box and connected to the signal acquisition and processing unit through the DB37 adapter cable. S300, signal acquisition and processing unit: amplifies and converts the signal from the probe, and the computer collects and identifies it. It has built-in aviation linear power supply, differential amplifier, signal collector, alarm module, buzzer, and converts the processed signal into a form that can be received by the terminal processing unit; S400, terminal acquisition and processing unit: provides a variety of equipment options, including portable computers, desktop computers, and industrial computers, which receive signals sent by the signal acquisition and processing unit, process them and form the final test results, which can be displayed, stored, and printed; S500, workpiece magnetization and detection unit: magnetize the heat exchange tube to generate a leakage magnetic field at the defect location, use a through-type coil to energize to complete the magnetization process, attach the probe to the surface of the heat exchange tube, scan along the curved path, and detect defects on the inner and outer walls of the heat exchange tube; S600, demagnetization and subsequent processing unit: After the inspection is completed, the heat exchange tube is placed in the demagnetizer to complete the demagnetization to avoid interference with subsequent processes. Subsequent processing is carried out according to the inspection results, that is, repairing and replacing defective heat exchange tubes.

2. According to the high-end equipment heat exchanger micron-level magnetic flux leakage detection process described in claim 1, it is characterized in that: The S100 detection probe unit adopts a probe shell for positioning, and a high-precision TMR high-sensitivity sensor is arranged on the corresponding detection surface, which is 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 intensity, and probe B is used to detect the normal component HPY of the leakage magnetic field intensity. The specific method for detecting the tangential component HPX and the normal component HPY of the leakage magnetic field intensity is as follows: when the ferromagnetic component in the geomagnetic field environment is subjected to an external load, a fixed node of a magnetic domain with magnetostrictive properties is generated in the stress concentration area, a magnetic pole is generated, and a demagnetizing field is formed, so that the magnetic permeability of the ferromagnetic metal here is minimized, and a leakage magnetic field is formed on the metal surface. This irreversible change of the magnetic state still retains the "memory" of the position of microscopic defects and stress concentration after the working load is eliminated, that is, the "magnetic memory effect". The tangential component HPX of the leakage magnetic field intensity 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, and the diagnosis of defects and stress concentration on the component is completed.

3. According to claim 2, a high-end equipment heat exchanger micron-level magnetic flux leakage detection process is characterized in that: The S100 uses probe A and probe B to diagnose and detect signals in the HPX and HPY directions respectively. The probe is attached to the surface wall of the arc surface of the workpiece, and the arc surface path is manually scanned. The shape of the probe matches the arc surface of the workpiece and fits tightly to the surface. The position of the abnormal waveform is repeatedly scanned to determine. 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.

4. According to the high-end equipment heat exchanger micron-level magnetic flux leakage detection process of claim 1, it is characterized in that: The S200 adapter box connection unit uses an aluminum customized adapter box, which is equipped 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 is connected to a corresponding 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 preliminarily organizes and integrates 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.

5. According to the high-end equipment heat exchanger micron-level magnetic flux leakage detection process of claim 1, it is characterized in that: The S300 signal acquisition and processing unit amplifies and converts the signal from the probe, and the computer collects and identifies the signal. The unit has a built-in aviation linear power supply, a differential amplifier, a signal collector, an alarm module, and a buzzer. The contents include: The aviation linear power supply provides stable power support for the entire unit, allowing each component to operate normally; The differential amplifier accurately amplifies the weak signal received from the adapter box to enhance the signal strength. The amplified signal is used for subsequent processing and analysis. The signal collector collects the amplified signal in real time and converts it into a digital signal for computer processing; When the alarm module detects an abnormal signal, it will trigger an alarm to alert the operator; The buzzer cooperates with the alarm module to sound an alarm to remind the operator to conduct further inspection.

6. According to claim 5, a high-end equipment heat exchanger micron-level magnetic flux leakage detection process is characterized in that: The S300 receives signals from the adapter box through the DB37 socket. These signals are the tangential component HPX and normal component HPY signals of the leakage magnetic field strength detected by probes A and 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 processing unit to prepare for subsequent analysis and processing.

7. According to claim 1, a high-end equipment heat exchanger micron-level magnetic flux leakage detection process is characterized in that: The S400 receives digital signals and data packets in a specific format from the S300 signal acquisition and processing unit, performs in-depth analysis, processing and display of these data, and finally generates a test result report. The unit supports a variety of device options, including portable computers, desktop computers and industrial computers, to meet the testing needs in different scenarios. The specific steps are as follows: S401, signal reception: the terminal acquisition processing unit receives the digital signal and the data packet of a specific format from the signal acquisition processing unit; S402, data processing: analyzing and processing the received signal, identifying the characteristic information in the signal and the abnormal change of the leakage magnetic field, judging whether there is a defect in the heat exchange tube and the type and location of the defect; S403, result display: displaying the processed test results in a visual manner, presenting an image of the heat exchange tube, and marking the location and information of the defects; S404, data storage and printing: The test result report is stored in the computer hard disk and cloud storage for subsequent analysis and use. A printing function is also provided, and the operator prints the test result report as a basis for test records and processing.

8. According to claim 1, a high-end equipment heat exchanger micron-level magnetic flux leakage detection process is characterized in that: When the S400 terminal acquisition and processing unit completes the inspection result report and confirms that the heat exchange tube has defects and needs further verification, the S500 workpiece magnetization and detection unit prepares a through-type coil and a magnetization power supply, places the heat exchange tube to be inspected in the magnetization device, and generates a magnetic field by energizing the through-type coil. The magnetic field acts on the heat exchange tube, so that the internal defect position generates a leakage magnetic field due to the magnetostrictive effect. During the magnetization process, the current size and time are controlled. After the 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 adapter box connection unit. After 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 position of the defect. 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 defect exists and the position is accurate, demagnetization is performed.

9. According to claim 8, a high-end equipment heat exchanger micron-level magnetic flux leakage detection process is characterized in that: After confirming that the heat exchange tube has defects and is accurately located, the S600 takes the heat exchange tube out of the detection device and immediately puts it into the demagnetizer. The demagnetizer uses AC demagnetization and DC demagnetization methods 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 the 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 test result report, a processing decision is made for the heat exchange tube, including marking and recording if there are minor defects in the heat exchange tube, and repairing and replacing if there are serious defects in the heat exchange tube that affect the heat exchange efficiency and pose a safety hazard. 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.

10. According to claim 1, a high-end equipment heat exchanger micron-level magnetic flux leakage detection process is characterized in that: The leakage magnetic detection process is to manually scan and detect the bending area of ​​the C-type tube by a probe. After magnetization in the magnetizer, the detection surface is scanned by the probe. If abnormal waveforms appear during the detection process, the alarm module and buzzer of the signal acquisition and processing unit will give an alarm prompt, and demagnetize the normal parts.

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