Synchronous infrared thermal imaging defect detection device and method in bent pipe simmering process

Abstract

The invention provides a synchronous infrared thermal imaging defect detection device and a synchronous infrared thermal imaging defect detection method in a bent pipe simmering process. A synchronous infrared thermal imaging defect detection device in the elbow bending process comprises a hot-bending elbow production line, a plurality of thermal infrared imagers and a data acquisition and processing device, an induction heating coil is installed on the hot-bending elbow production line, the thermal infrared imagers are installed on the hot-bending elbow production line, and the data acquisition and processing device is installed on the hot-bending elbow production line. The plurality of thermal infrared imagers are arranged adjacent to the induction heating coil, and the data acquisition and processing equipment is electrically connected with the plurality of thermal infrared imagers respectively.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of non-destructive testing of oil and gas pipelines, and particularly relates to a device and method for synchronous infrared thermal imaging defect detection during the bending process of a bent pipe. BACKGROUND

[0002] Hot-bending bent pipes are key components of oil and gas pipelines, used to change the direction of the pipeline. The manufacturing process usually adopts intermediate frequency induction heating technology to locally heat the straight pipe to a plastic state and then bend it. The quality of the bent pipe is directly related to the safe operation of the entire pipe network.

[0003] In the manufacturing process of hot-bending bent pipes, original defects (such as delamination, inclusions, and micro-cracks) that may exist in the pipe blank base material or new defects (such as overheating cracks) generated during the heating process can seriously weaken the mechanical properties of the bent pipe and pose a significant safety hazard. Therefore, it is essential to conduct 100% non-destructive testing of hot-bending bent pipes as a quality assurance link.

[0004] Currently, non-destructive testing of hot-bending bent pipes is usually carried out after the bending process is completed and the pipe is cooled. Since the shape of the hot-bending bent pipe is a circular arc with different curvature radii and angles, there is currently no automated non-destructive testing method. The commonly used methods include manual ultrasonic testing (UT), magnetic powder testing (MT), and radiographic testing (RT, only for defect re-evaluation). These traditional methods have the following obvious drawbacks: Lag: The detection is carried out after the manufacturing process is completed. Once a defective product is found, the entire bent pipe has already been scrapped, resulting in a huge waste of raw materials, energy, and labor, and high costs.

[0005] Cannot reflect the defect expansion behavior during the heating process: Some defects (such as cracks) may expand or change during the heating process. The detection after cooling cannot capture this dynamic process and cannot provide real-time feedback for process optimization.

[0006] Detection efficiency and coverage: Ultrasonic testing requires coupling agent and point-by-point scanning; radiographic testing has radiation safety risks and is sensitive to crack direction. The current non-destructive testing of bent pipes uses manual testing methods for ultrasonic, magnetic powder, penetration, and radiographic testing, which has extremely low testing efficiency and exists missed detection, and cannot truly achieve 100% testing. In summary, there is no automated full-pipe non-destructive testing method for bent pipes.

[0007] The existing patent one CN112986330B discloses a pipeline defect detection data collection device and method based on infrared thermal imaging. The device is connected by double studs in sequence from three parts of infrared thermal imaging, laser excitation and power supply. The infrared thermal imaging part includes an imaging controller, an imaging shell, a sealing baffle and multiple thermal imaging cameras. The laser excitation part is composed of a power part, an excitation part and an excitation controller. The power supply part is composed of a power supply shell, a sealing baffle and a battery. The method of the present application uses a device with a serpentine pipeline robot as a carrier. When the laser excitation is used to heat the pipe wall, the thermal wave on the pipe wall surface has transverse propagation characteristics, thereby having strong sensitivity to cracks on the pipe wall surface. The power of the excitation and the rotation speed of the heating strip are controlled to keep the pipeline at the most suitable temperature, making the thermal imaging data have higher contrast. At the same time, image distortion correction algorithm and navigation algorithm are used to make the defect positioning more accurate. The existing patent one pushes the detection device in the pipeline to walk in the pipeline by the fluid in the pipeline in operation, heats the pipeline by laser excitation, and detects the defects on the inner wall of the pipeline by the infrared thermal imaging part. However, the scheme of the existing patent one cannot detect defects synchronously, on-line, in real time and automatically during the heating process of the hot-bending pipe.

[0008] The existing patent two CN118641580A discloses a welding seam defect detection system and method based on infrared thermal imaging and deep learning. The detection system includes a control end, a temperature control module, a thickness detection module, a thermal signal processing module, a feature extraction module, an intelligent detection module and a receiving end. The control end controls the temperature control module, the thickness detection module, the thermal signal processing module, the feature extraction module and the intelligent detection module. The temperature control module enhances the surface temperature of the steel sample by combining active and passive excitation. The thickness detection module collects sample data through a thickness detection probe and transmits it to the receiving end. The present application enhances the thermal radiation of the detected object surface by adding an active thermal excitation source, obtains a thermal image with more obvious temperature difference, and improves the detection accuracy. It is beneficial to master the intelligent operation equipment technology of petrochemical pipeline and oil tank detection, and to ensure the safe and efficient production and operation of petrochemical enterprises. The existing patent two uses an active fluid cooling excitation method to process the outer surface of the in-use metal pipeline for a short time, amplifies the temperature difference of the defect part, and is beneficial to the capture of the temperature difference by the infrared thermal imager, thereby realizing on-site rapid scanning and detection. However, the scheme of the existing patent two cannot detect defects synchronously, on-line, in real time and automatically during the heating process of the hot-bending pipe.

[0009] The existing patent three CN120307625A discloses a kind of hot bending pipe polyethylene zero hollow drum full-automatic winding anticorrosion process, comprising the following steps: sand blasting to Sa2.5 level is rusted to the outer surface of hot bending pipe, epoxy primer is coated after cleaning;Adopt infrared heating to uniformly preheat the surface of elbow pipe to 40-60 ℃;Polyethylene tape is spirally wound along the axis of elbow pipe to form winding layer, and the tension of winding is constant 50-80N, and the lap rate is 30-50%;Flexible vacuum film is covered on the surface of winding layer, -0.1--0.08MPa negative pressure is applied and maintained for 5-10min.The present application ensures clean base surface by sand blasting and epoxy primer coating, combined with infrared preheating, constant tension winding and lap rate control, so that polyethylene tape is closely attached to the curved surface of elbow pipe, and flexible vacuum film is used to apply negative pressure to immediately remove air bubbles in the winding layer, and then gradient temperature control curing is carried out to realize polyethylene layer zero hollow drum structure, which greatly enhances the bonding strength and long-term sealing property of anticorrosion layer and matrix.The existing patent three combines infrared preheating hot bending pipe polyethylene on the hot bending pipe polyethylene.But the existing patent three only uses the heating function of infrared preheating, and cannot detect defects synchronously, on-line, in real time and automatically during the heating process of hot bending pipe bending.

[0010] Therefore, there is an urgent need in the art for a method and device capable of detecting defects synchronously, on-line, in real time and automatically during the heating process of hot bending pipe bending, to realize active control of product quality, reduce waste and improve manufacturing efficiency and safety. SUMMARY

[0011] The technical problem to be solved by the present application is to provide a bending pipe bending process synchronous infrared thermal imaging defect detection device and method to solve the problems of the prior art.

[0012] The technical solution for solving the above technical problem is as follows: a bending pipe bending process synchronous infrared thermal imaging defect detection device, comprising: a hot bending pipe production line, a plurality of infrared thermal imagers and a data acquisition and processing device, an induction heating coil is installed on the hot bending pipe production line, a plurality of infrared thermal imagers are installed on the hot bending pipe production line, and the plurality of infrared thermal imagers are arranged adjacent to the induction heating coil, and the data acquisition and processing device is electrically connected with the plurality of infrared thermal imagers respectively.

[0013] The beneficial effects of the technical solution of the present application are: the device is integrated on the hot bending pipe production line, and infrared thermal imaging detection is carried out synchronously during the induction heating bending process of the elbow pipe, so as to realize real-time identification of internal defects.The two-dimensional temperature field distribution image of the heating area is collected in real time by using infrared thermal imager while the elbow pipe is heated by medium frequency induction coil, and the defects are identified by analyzing the uniformity of temperature distribution and the difference of temperature rising curve in thermal image.The synchronous, on-line and non-destructive detection of hot bending pipe during induction heating bending process is realized.Defects can be found immediately, which provides the possibility for process intervention.

[0014] Further, the hot bending pipe production line is provided with a ring-shaped support parallel to the induction heating coil, and the plurality of infrared thermal imagers are mounted on the ring-shaped support.

[0015] The beneficial effects of the above further technical solutions are that the ring-shaped support facilitates the installation and maintenance of the plurality of infrared thermal imagers, and facilitates the non-contact and non-destructive detection of the pipe by the infrared thermal imagers. The automatic non-destructive inspection of the hot bending pipe is realized, and the inspection coverage and efficiency are improved. The infrared detection is non-contact, is not affected by electromagnetic fields, has no radiation risk, and is safe.

[0016] Further, the plurality of infrared thermal imagers are mounted on the ring-shaped support at equal intervals along the circumference of the ring-shaped support.

[0017] The beneficial effects of the above further technical solutions are that the infrared thermal imagers are used to continuously shoot infrared thermal images of the heating area. The data can be collected in all directions. The infrared thermal imaging provides two-dimensional temperature field information, which can intuitively show the temperature distribution of the entire heating area, has a wide coverage, has no missed detection dead angle, and is especially suitable for large-area rapid scanning. The infrared detection is non-contact, is not affected by electromagnetic fields, has no radiation risk, and is safe.

[0018] Further, a cooling and protection system for protecting the infrared thermal imagers is mounted on the hot bending pipe production line, and the cooling and protection system is arranged adjacent to the plurality of infrared thermal imagers.

[0019] The beneficial effects of the above further technical solutions are that the cooling and protection system is used to cool the thermal imagers and the protective cover, and ensures stable operation of the equipment.

[0020] Further, the cooling and protection system comprises a protective cover and a cooling device, the cooling device is wrapped on the outside of the infrared thermal imager, and the protective cover is arranged on the outside of the cooling device.

[0021] The beneficial effects of the above further technical solutions are that the cooling and protection system is used to cool the thermal imagers and the protective cover, and ensures stable operation of the equipment. The structure is simplified, and the cost is reduced.

[0022] Further, the cooling device is a gas-cooled cooling device or a liquid-cooled cooling device.

[0023] The beneficial effects of the above further technical solutions are that the cooling device can be selected according to actual needs, and the applicability is improved.

[0024] Further, the data acquisition and processing equipment is electrically connected with a display and an alarm device.

[0025] The beneficial effects of adopting the above-mentioned further technical solution are: the display is used to show the temperature field distribution, temperature data, and defect alarm information at different locations of the heating zone in real time. When a defect is detected, the alarm device can alert the operator.

[0026] Furthermore, the alarm device is an audible and visual alarm.

[0027] The beneficial effects of adopting the above-mentioned further technical solution are: the display is used to show the temperature field distribution, temperature data, and defect alarm information at different locations of the heating zone in real time. When a defect is detected, the operator can be alerted through an audible and visual alarm.

[0028] Furthermore, the hot-bending tube production line is equipped with a tube bending machine, on which a straight tube to be bent is placed, and multiple infrared thermal imagers and induction heating coils are arranged around the straight tube to be bent.

[0029] The beneficial effects of adopting the above-mentioned further technical solution are as follows: The device is integrated into the hot bending tube production line, and performs infrared thermal imaging detection simultaneously during the induction heating bending process to identify internal defects in real time. While the bent tube is heated by the medium-frequency induction coil, an infrared thermal imager is used to acquire a two-dimensional temperature field distribution image of the heating area in real time. Defects are identified by analyzing the uniformity of the temperature distribution and the differences in the heating curves in the thermal image. This achieves synchronous, online, and non-destructive testing of hot bending tubes during the induction heating bending process. It enables immediate defect detection, providing the possibility for process intervention. Infrared thermal imaging provides two-dimensional temperature field information, which can intuitively display the temperature distribution of the entire heating area, with wide coverage and no blind spots, making it particularly suitable for large-area rapid scanning.

[0030] Furthermore, the angle between the optical axis of the infrared thermal imager and the surface normal of the straight tube to be heated ranges from 30° to 45°.

[0031] The beneficial effects of adopting the above-mentioned further technical solutions are: avoiding specular reflection interference. Infrared thermal imagers are used to continuously capture infrared thermal images of the heated area, facilitating comprehensive data acquisition. Infrared thermal imaging provides two-dimensional temperature field information, which can intuitively display the temperature distribution of the entire heated area, with wide coverage and no blind spots, making it particularly suitable for large-area rapid scanning. Infrared detection is non-contact, unaffected by electromagnetic field interference, and poses no radiation risk, ensuring good safety.

[0032] Furthermore, the outer diameter of the straight pipe to be heated is 1219mm, the wall thickness of the straight pipe to be heated is 30mm, and the straight pipe to be heated is an X80 grade steel pipe.

[0033] The advantages of adopting the above-mentioned further technical solutions are: they are suitable for defect detection in large-diameter straight pipes to be heated. Infrared thermal imaging provides two-dimensional temperature field information, which can intuitively display the temperature distribution of the entire heating area, with wide coverage and no blind spots, making it particularly suitable for large-area rapid scanning. Infrared detection is non-contact, unaffected by electromagnetic interference, and has no radiation risk, ensuring good safety.

[0034] Furthermore, the fields of view of the multiple infrared thermal imagers cover the heating zone of the straight tube to be heated.

[0035] The beneficial effects of adopting the above-mentioned further technical solutions are: Infrared thermal imagers are used to continuously capture infrared thermal images of the heated area, facilitating comprehensive data acquisition. Infrared thermal imaging provides two-dimensional temperature field information, which can intuitively display the temperature distribution of the entire heated area, with wide coverage and no blind spots, making it particularly suitable for large-area rapid scanning. Infrared detection is non-contact, unaffected by electromagnetic interference, and poses no radiation risk, ensuring good safety.

[0036] Furthermore, the heating zone of the straight tube to be heated is divided into an induction heating heating zone and an induction heating constant temperature zone, both of which are adjacent to the induction heating coil.

[0037] The beneficial effects of adopting the above-mentioned further technical solutions are: Infrared thermal imagers are used to continuously capture infrared thermal images of the heated area, facilitating comprehensive data acquisition. Infrared thermal imaging provides two-dimensional temperature field information, which can intuitively display the temperature distribution of the entire heated area, with wide coverage and no blind spots, making it particularly suitable for large-area rapid scanning. Infrared detection is non-contact, unaffected by electromagnetic interference, and poses no radiation risk, ensuring good safety.

[0038] Furthermore, the infrared thermal imager operates in a wavelength range of 3-5 μm or 8-14 μm.

[0039] The beneficial effects of adopting the above-mentioned further technical solutions are: meeting the defect detection requirements of the straight pipe to be heated, improving performance, and enhancing applicability.

[0040] Furthermore, this invention also provides a method for detecting defects by synchronous infrared thermal imaging during the bending and hot-bending process. Based on the aforementioned device for detecting defects by synchronous infrared thermal imaging during the bending and hot-bending process, the method includes: during the process of induction heating and hot-bending of the straight pipe to be bent using an induction heating coil in a hot-bending production line, simultaneously acquiring thermal images of the straight pipe to be bent using multiple infrared thermal imagers; and analyzing the thermal images using data acquisition and processing equipment to identify defects.

[0041] The beneficial effects of adopting the technical solution of this invention are as follows: The device is integrated into the hot bending pipe production line, and performs infrared thermal imaging detection simultaneously during the induction heating bending process to identify internal defects in real time. While the bent pipe is heated by the medium-frequency induction coil, an infrared thermal imager is used to acquire a two-dimensional temperature field distribution image of the heating area in real time. Defects are identified by analyzing the uniformity of the temperature distribution and the differences in the heating curves in the thermal image. This achieves synchronous, online, and non-destructive testing of hot bending pipes during the induction heating bending process. It enables immediate defect detection, providing the possibility for process intervention.

[0042] Furthermore, the thermal image is a two-dimensional temperature field distribution image of the heating area of ​​the straight tube to be heated.

[0043] The beneficial effects of adopting the above-mentioned further technical solution are as follows: while the bent pipe is heated by the medium-frequency induction coil, a two-dimensional temperature field distribution image of the heated area is acquired in real time using an infrared thermal imager. Defects are identified by analyzing the uniformity of the temperature distribution and the differences in the heating curves in the thermal image. Infrared thermal imaging provides two-dimensional temperature field information, which can intuitively display the temperature distribution of the entire heated area, with wide coverage and no blind spots, making it particularly suitable for large-area rapid scanning.

[0044] Furthermore, the step of analyzing the thermal image using data acquisition and processing equipment to identify defects includes: analyzing the uniformity of temperature distribution and the differences in heating curves in the thermal image using data acquisition and processing equipment to identify defects.

[0045] The beneficial effects of adopting the above-mentioned further technical solution are: by utilizing the differences in heating rate, heat capacity, and thermal conductivity between the defective area and the normal parent material, the abnormal temperature field distribution can be visually displayed through infrared thermal imaging technology, thereby identifying defects such as delamination, inclusions, and cracks in real time. By cross-referencing the heating rate and maximum temperature signals, the defect location can be jointly determined, avoiding errors caused by relying on a single signal and ensuring the accuracy of the results.

[0046] Furthermore, before the step of identifying defects by analyzing the uniformity of temperature distribution and the differences in heating curves in the thermal images using data acquisition and processing equipment, the method includes: analyzing and stitching together thermal images acquired by multiple infrared thermal imagers using data acquisition and processing equipment.

[0047] The beneficial effects of adopting the above-mentioned further technical solutions are: facilitating temperature field analysis. It allows for the intuitive display of abnormal temperature field distribution through infrared thermal imaging technology, thereby enabling real-time identification of defects such as delamination, inclusions, and cracks.

[0048] Furthermore, the step of identifying defects by analyzing the uniformity of temperature distribution and the differences in heating curves in the thermal image using data acquisition and processing equipment includes: acquiring a temperature uniformity threshold and a heating rate threshold using the data acquisition and processing equipment; comparing and analyzing the differences in real-time temperature values ​​and heating rates of different regions in the thermal image using the data acquisition and processing equipment; determining whether the differences in real-time temperature values ​​of different regions in the thermal image exceed the temperature uniformity threshold, and determining whether the differences in heating rates of different regions in the thermal image exceed the heating rate threshold; when the difference in real-time temperature values ​​of a region exceeds the temperature uniformity threshold, and / or the difference in heating rates of that region exceeds the heating rate threshold, the region is determined to be a defect region.

[0049] The beneficial effects of adopting the above-mentioned further technical solution are: by setting a temperature uniformity threshold or a heating rate threshold, when the temperature in a certain area abnormally exceeds the threshold, it is automatically identified as a defect area. By cross-referencing the heating rate and the maximum temperature signals, the defect location is jointly determined, avoiding errors caused by a single signal evaluation and ensuring the accuracy of the results.

[0050] Furthermore, after the step of determining that a region is a defective region when the difference in real-time temperature values ​​of a region exceeds the temperature uniformity threshold and / or the difference in the heating rate of the region exceeds the heating rate threshold, the method further includes: marking, classifying, and recording the location coordinates of the defective region using data acquisition and processing equipment.

[0051] The beneficial effects of adopting the above-mentioned further technical solutions are: marking the defective parts for subsequent processing, avoiding the scrapping of the entire bent pipe, and reducing production costs.

[0052] Furthermore, the step of recording the location coordinates of the defect area through the data acquisition and processing equipment includes: compensating the current position of the defect area according to the advancement rate of the straight pipe to be heated by the data acquisition and processing equipment to obtain the actual location coordinates of the defect area.

[0053] The beneficial effect of adopting the above-mentioned further technical solution is that, since the pipe bend is advanced at a constant speed, the position of a certain fixed position of the pipe body in each frame of thermal image will change as the pipe bend advances, and the collected dynamic temperature field data needs to be compensated according to the advancement rate of the pipe bend.

[0054] Furthermore, the step of compensating for the position of the defect area according to the advancing rate of the straight pipe to be heated by the data acquisition and processing equipment to obtain the actual position coordinates of the defect area includes: subtracting the advancing distance of the straight pipe to be heated from the current position of the defect area by the data acquisition and processing equipment to obtain the actual position coordinates of the defect area.

[0055] The beneficial effect of adopting the above-mentioned further technical solution is that the actual position coordinates of the corresponding pipe body can be obtained by subtracting the advancement distance of the bend from the current position, so as to realize the compensation of the collected dynamic temperature field data according to the advancement rate of the bend.

[0056] Furthermore, after the steps of marking, classifying, and recording the location coordinates of the defective area using the data acquisition and processing equipment, the process includes: transmitting the temperature field distribution, temperature data, and defect alarm information at different locations in the heating area to a display for display using the data acquisition and processing equipment; and controlling the alarm device to sound an alarm when a defective area exists using the data acquisition and processing equipment.

[0057] The beneficial effects of adopting the above-mentioned further technical solution are: the display is used to show the temperature field distribution, temperature data, and defect alarm information at different locations of the heating zone in real time. When a defect is detected, the alarm device can alert the operator.

[0058] Furthermore, after the step of controlling the alarm device to sound an alarm when a defective area exists, the method further includes: adjusting the heating process parameters of the hot bending tube production line through the data acquisition and processing device to suppress the expansion of defects.

[0059] The beneficial effects of adopting the above-mentioned further technical solutions are: providing real-time feedback to operators, enabling them to adjust heating process parameters in a timely manner, suppressing defect expansion, or marking defective areas for subsequent processing, avoiding the scrapping of the entire bent pipe, and reducing production costs.

[0060] Furthermore, after the step of analyzing the thermal image through the data acquisition and processing equipment to identify defects, the method includes: establishing a thermal image data archive of the heating process through the data acquisition and processing equipment.

[0061] The beneficial effects of adopting the above-mentioned further technical solutions are: establishing a thermal imaging data archive of the heating process, providing data support for product quality traceability and process optimization. The recorded thermal imaging data of the entire heating process can be used to establish a product quality database, providing a valuable data foundation for analyzing the causes of defects and optimizing the heating process.

[0062] Furthermore, the step of simultaneously acquiring thermal images of the straight tube to be bent using multiple infrared thermal imagers during the induction heating process of the hot bending tube production line using induction heating coils includes: activating the cooling and protection system through data acquisition and processing equipment during the induction heating process of the straight tube to be bent using induction heating coils, and simultaneously acquiring thermal images of the straight tube to be bent using multiple infrared thermal imagers.

[0063] The beneficial effects of adopting the above-mentioned further technical solution are: the cooling and protection system is used to cool down the thermal imager and protective cover, ensuring stable operation of the equipment. To avoid the defective area becoming undetectable due to small temperature differences between it and the normal area when the temperature rises to the maximum temperature, the detection device records the data throughout the entire heating process.

[0064] The advantages of additional aspects of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0065] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0066] Figure 1 This is one of the structural schematic diagrams of the synchronous infrared thermal imaging defect detection device for the bending and heating process of the pipe provided in the embodiment of the present invention.

[0067] Figure 2 This is the second schematic diagram of the structure of the synchronous infrared thermal imaging defect detection device for the bending and heating process provided in this embodiment of the invention.

[0068] Figure 3 This is the third schematic diagram of the structure of the synchronous infrared thermal imaging defect detection device for the bending and heating process provided in this embodiment of the invention.

[0069] Figure 4 This is a schematic diagram of a typical defect detected in a thermal image by the synchronous infrared thermal imaging defect detection device for the bending and heating process provided in an embodiment of the present invention.

[0070] The following are the reference numerals: 1. Straight pipe to be heated; 2. Bending section of the pipe; 3. Induction heating coil; 4. Infrared thermal imager; 5. Cooling and protection system; 6. Induction heating heating zone; 7. Induction heating constant temperature zone; 8. Water-cooled spray line after bending; 9. Data acquisition and processing equipment; 10. Display. Detailed Implementation

[0071] The principles and features of the present invention are described below with reference to the accompanying drawings. The embodiments described are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0072] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0073] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0074] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0075] In the description of the embodiments of the present invention, it should be noted that if terms such as "upper", "lower", "horizontal", "inner" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of the invention is usually placed during use, they are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0076] In the description of the embodiments of the present invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the present invention according to the specific circumstances.

[0077] like Figures 1 to 3 As shown, this embodiment of the invention provides a synchronous infrared thermal imaging defect detection device for the bending process of pipes, including: a hot bending production line, multiple infrared thermal imagers 4, and a data acquisition and processing device 9. An induction heating coil 3 is installed on the hot bending production line, and the multiple infrared thermal imagers 4 are installed on the hot bending production line. The multiple infrared thermal imagers 4 are arranged adjacent to the induction heating coil 3, and the data acquisition and processing device 9 is electrically connected to the multiple infrared thermal imagers 4 respectively.

[0078] The beneficial effects of adopting the technical solution of this invention are as follows: The device is integrated into the hot bending pipe production line, and performs infrared thermal imaging detection simultaneously during the induction heating bending process to identify internal defects in real time. While the bent pipe is heated by the medium-frequency induction coil, an infrared thermal imager is used to acquire a two-dimensional temperature field distribution image of the heating area in real time. Defects are identified by analyzing the uniformity of the temperature distribution and the differences in the heating curves in the thermal image. This achieves synchronous, online, and non-destructive testing of hot bending pipes during the induction heating bending process. It enables immediate defect detection, providing the possibility for process intervention.

[0079] This invention relates to the field of non-destructive testing technology for oil and gas pipelines, specifically to an online quality monitoring device (synchronous infrared thermal imaging defect detection device for the bending process) for the manufacturing process of large-diameter hot-bending pipes in oil and gas pipeline engineering, particularly a device that performs simultaneous infrared thermal imaging detection during the induction heating bending process of the bending pipe to identify internal defects in real time.

[0080] This invention provides a synchronous infrared thermal imaging defect detection device for the hot bending process of pipes. This device enables synchronous, online, and non-destructive testing of hot-bent pipes during induction heating, shifting quality monitoring from an "after-the-fact" to an "in-process" approach. Utilizing the differences in heating rate, heat capacity, and thermal conductivity between defective areas and normal base material, infrared thermal imaging technology visually displays abnormal temperature field distributions, thereby identifying defects such as delamination, inclusions, and cracks in real time. It provides real-time feedback to operators, allowing them to adjust heating process parameters (such as power and heating speed) promptly to suppress defect propagation or mark defective areas for subsequent processing, avoiding the scrapping of the entire bent pipe and reducing production costs. It establishes a thermal imaging data archive of the heating process, providing data support for product quality traceability and process optimization. This achieves automated non-destructive inspection of hot-bent pipes, improving inspection coverage and efficiency.

[0081] Figures 1 to 3 The layout of the infrared inspection device on the production line is shown, omitting the bending fixtures that are irrelevant to this design. A straight pipe (the straight pipe to be bent 1) moves forward on the bending machine, where an induction coil (induction heating coil 3) locally heats it (from the induction heating rise zone 6 to the induction heating constant temperature zone 7). After bending, it is water-cooled (after-bend water-cooling spray line 8) to form a bent pipe (bent section 2). Multiple infrared thermal imagers 4 are arranged parallel to the induction coils (induction heating coils 3) (uniformly distributed along the circumference of the steel pipe; the number is calculated based on the effective inspection area of ​​the thermal imager and the outer diameter of the bent pipe to be inspected), always aligned with the heating area (from the induction heating rise zone 6 to the induction heating constant temperature zone 7). A cooling and isolation system 5 protects the thermal imagers (infrared thermal imagers 4). The collected data is sent to a processing device (data acquisition and processing device 9) for analysis, and the results are displayed on a monitor 10.

[0082] like Figures 1 to 3 As shown, further, an annular support is installed on the hot bending tube production line, the annular support is parallel to the induction heating coil 3, and multiple infrared thermal imagers 4 are installed on the annular support.

[0083] The beneficial effects of adopting the above-mentioned further technical solution are as follows: the ring-shaped bracket facilitates the installation and maintenance of multiple infrared thermal imagers, and enables non-contact, non-destructive testing of bent pipes by infrared thermal imagers. This achieves automated, non-destructive testing of hot-bent pipes, improving inspection coverage and efficiency. Infrared detection is non-contact, unaffected by electromagnetic interference, and poses no radiation risk, ensuring good safety.

[0084] like Figures 1 to 3 As shown, further, a plurality of the infrared thermal imagers 4 are mounted at equal intervals along the circumference of the annular bracket on the annular bracket.

[0085] The beneficial effects of adopting the above-mentioned further technical solutions are: Infrared thermal imagers are used to continuously capture infrared thermal images of the heated area, facilitating comprehensive data acquisition. Infrared thermal imaging provides two-dimensional temperature field information, which can intuitively display the temperature distribution of the entire heated area, with wide coverage and no blind spots, making it particularly suitable for large-area rapid scanning. Infrared detection is non-contact, unaffected by electromagnetic interference, and poses no radiation risk, ensuring good safety.

[0086] like Figures 1 to 3 As shown, the hot-bending tube production line is further equipped with a cooling and protection system 5 for protecting the infrared thermal imager 4, and the cooling and protection system 5 is arranged adjacent to a plurality of the infrared thermal imagers 4.

[0087] The beneficial effects of adopting the above-mentioned further technical solutions are: the cooling and protection system is used to cool down the thermal imager and the protective cover, ensuring stable operation of the equipment.

[0088] Furthermore, the cooling and protection system 5 includes a protective cover and a cooling device, wherein the cooling device covers the outside of the infrared thermal imager 4 and the protective cover is disposed on the outside of the cooling device.

[0089] The beneficial effects of adopting the above-mentioned further technical solutions are: the cooling and protection system is used to cool the thermal imager and protective cover, ensuring stable equipment operation; and the structure is simplified, reducing costs.

[0090] Furthermore, the cooling device is an air-cooled cooling device or a liquid-cooled cooling device.

[0091] The beneficial effects of adopting the above-mentioned further technical solutions are: it facilitates the selection of cooling devices according to actual needs and improves applicability.

[0092] likeFigures 1 to 3 As shown, the data acquisition and processing device 9 is further electrically connected to the display 10 and the alarm device.

[0093] The beneficial effects of adopting the above-mentioned further technical solution are: the display is used to show the temperature field distribution, temperature data, and defect alarm information at different locations of the heating zone in real time. When a defect is detected, the alarm device can alert the operator.

[0094] Furthermore, the alarm device is an audible and visual alarm.

[0095] The beneficial effects of adopting the above-mentioned further technical solution are: the display is used to show the temperature field distribution, temperature data, and defect alarm information at different locations of the heating zone in real time. When a defect is detected, the operator can be alerted through an audible and visual alarm.

[0096] like Figures 1 to 3 As shown, the hot-bending production line is further equipped with a pipe bending machine, on which a straight pipe 1 to be bent is mounted, and multiple infrared thermal imagers 4 and induction heating coils 3 are arranged around the straight pipe 1 to be bent.

[0097] The beneficial effects of adopting the above-mentioned further technical solution are as follows: The device is integrated into the hot bending tube production line, and performs infrared thermal imaging detection simultaneously during the induction heating bending process to identify internal defects in real time. While the bent tube is heated by the medium-frequency induction coil, an infrared thermal imager is used to acquire a two-dimensional temperature field distribution image of the heating area in real time. Defects are identified by analyzing the uniformity of the temperature distribution and the differences in the heating curves in the thermal image. This achieves synchronous, online, and non-destructive testing of hot bending tubes during the induction heating bending process. It enables immediate defect detection, providing the possibility for process intervention. Infrared thermal imaging provides two-dimensional temperature field information, which can intuitively display the temperature distribution of the entire heating area, with wide coverage and no blind spots, making it particularly suitable for large-area rapid scanning.

[0098] Furthermore, the angle between the optical axis of the infrared thermal imager 4 and the surface normal of the straight tube 1 to be heated is in the range of 30°-45°.

[0099] The beneficial effects of adopting the above-mentioned further technical solutions are: avoiding specular reflection interference. Infrared thermal imagers are used to continuously capture infrared thermal images of the heated area, facilitating comprehensive data acquisition. Infrared thermal imaging provides two-dimensional temperature field information, which can intuitively display the temperature distribution of the entire heated area, with wide coverage and no blind spots, making it particularly suitable for large-area rapid scanning. Infrared detection is non-contact, unaffected by electromagnetic field interference, and poses no radiation risk, ensuring good safety.

[0100] Furthermore, the outer diameter of the straight pipe 1 to be heated is 1219mm, the wall thickness of the straight pipe 1 to be heated is 30mm, and the straight pipe 1 to be heated is an X80 grade steel pipe.

[0101] The advantages of adopting the above-mentioned further technical solutions are: they are suitable for defect detection in large-diameter straight pipes to be heated. Infrared thermal imaging provides two-dimensional temperature field information, which can intuitively display the temperature distribution of the entire heating area, with wide coverage and no blind spots, making it particularly suitable for large-area rapid scanning. Infrared detection is non-contact, unaffected by electromagnetic interference, and has no radiation risk, ensuring good safety.

[0102] like Figures 1 to 3 As shown, furthermore, the fields of view of the plurality of infrared thermal imagers 4 cover the heating zone of the straight tube 1 to be heated.

[0103] The beneficial effects of adopting the above-mentioned further technical solutions are: Infrared thermal imagers are used to continuously capture infrared thermal images of the heated area, facilitating comprehensive data acquisition. Infrared thermal imaging provides two-dimensional temperature field information, which can intuitively display the temperature distribution of the entire heated area, with wide coverage and no blind spots, making it particularly suitable for large-area rapid scanning. Infrared detection is non-contact, unaffected by electromagnetic interference, and poses no radiation risk, ensuring good safety.

[0104] like Figures 1 to 3 As shown, the heating zone of the straight tube 1 to be heated is further divided into an induction heating heating zone 6 and an induction heating constant temperature zone 7, both of which are adjacent to the induction heating coil 3.

[0105] The beneficial effects of adopting the above-mentioned further technical solutions are: Infrared thermal imagers are used to continuously capture infrared thermal images of the heated area, facilitating comprehensive data acquisition. Infrared thermal imaging provides two-dimensional temperature field information, which can intuitively display the temperature distribution of the entire heated area, with wide coverage and no blind spots, making it particularly suitable for large-area rapid scanning. Infrared detection is non-contact, unaffected by electromagnetic interference, and poses no radiation risk, ensuring good safety.

[0106] Furthermore, the infrared thermal imager 4 operates in a wavelength range of 3-5μm or 8-14μm.

[0107] The beneficial effects of adopting the above-mentioned further technical solutions are: meeting the defect detection requirements of the straight pipe to be heated, improving performance, and enhancing applicability.

[0108] The present invention provides a synchronous infrared thermal imaging defect detection device for the hot bending process of pipes. This device can be integrated into the hot bending production line and mainly includes: an induction heating coil 3, an infrared thermal imager 4, a cooling and protection system 5, a data acquisition and processing device 9, and a display and alarm device.

[0109] While the bent pipe (with a bent section 2 on the straight pipe 1 to be bent) is heated by a medium-frequency induction coil (induction heating coil 3), an infrared thermal imager 4 is used to collect a two-dimensional temperature field distribution image (i.e., thermal image) of the heated area in real time. Defects are identified by analyzing the uniformity of the temperature distribution and the differences in the heating curves in the thermal image. The basic principle is: when the pipe body is uniformly heated, the heat flow distribution in the defect-free area is uniform and the temperature field is continuous. However, when there are defects such as delamination, inclusions, or cracks, the thermophysical parameters (such as thermal conductivity and heat capacity) at the defect are different from those of the base material. This will cause abnormal "hot spots" (such as higher temperatures at cracks due to high thermal resistance) or "cold spots" (such as lower temperatures due to low thermal conductivity of inclusions) to appear in this area during the heating process, and different heating rates will be observed during the dynamic heating process.

[0110] The specific components of the device (synchronous infrared thermal imaging defect detection device for the pipe bending process) are as follows: Infrared thermal imager 4: Mounted on a ring-shaped bracket parallel to the induction heating coil 3, its spectral response range must match the heating temperature of the bent tube (typically 500℃-1200℃), and it must have sufficient spatial and temperature resolution to ensure that subtle temperature differences can be captured. Infrared thermal imager 4 is responsible for continuously capturing infrared thermal images of the heated area.

[0111] Cooling and Protection System 5: Since the thermal imager (infrared thermal imager 4) operates in a high-temperature, strong electromagnetic field environment, it must be protected. This system (cooling and protection system 5) includes a high-temperature resistant, magnetically shielded protective cover and an air-cooling or water-cooling device (liquid cooling device) to cool the thermal imager (infrared thermal imager 4) and the protective cover, ensuring stable operation of the equipment.

[0112] Data acquisition and processing device 9 receives the thermal video stream transmitted from infrared thermal imager 4. This device has built-in defect identification algorithm software, capable of: ① Data acquisition: Real-time acquisition of temperature field distribution, analysis and stitching of thermal images acquired by multiple infrared thermal imagers 4.

[0113] ② Coordinate calibration: Since the bend is advanced at a constant speed, the position of a certain fixed position of the tube in each frame of the thermal image will change as the bend advances. It is necessary to compensate the collected dynamic temperature field data according to the advancement rate of the bend. The actual position coordinates of the corresponding tube can be obtained by subtracting the advancement distance of the bend from the current position.

[0114] ③ Data comparison: Compare and analyze the differences in real-time temperature values ​​and the differences in heating rates between different regions.

[0115] ④ Defect identification: Set a temperature uniformity threshold or a heating rate threshold. When the temperature in a certain area exceeds the threshold abnormally, it will be automatically identified as a defect area.

[0116] ⑤ Defect Records: Mark and classify defects (such as suspected delamination, suspected cracks) and record their location coordinates.

[0117] ⑥ Display and alarm equipment: including a high-resolution display 10, which displays the temperature field distribution (different colors distinguish temperatures), temperature data, and defect alarm information at different locations of the heating zone (heating area) in real time. When a defect is detected, an audible and visual alarm can be used to alert the operator.

[0118] Because hot-bent pipes have an arc shape with varying radii and angles of curvature, there are currently no automated non-destructive testing methods available. Infrared thermal imaging can visually display the location and size of defects, but it is not possible to perform infrared thermal imaging inspection on pipes and most pipe fittings simultaneously with the heating process. Compared with existing technologies, this invention has the following significant advantages and positive effects: Real-time and synchronous: By integrating the detection process with the heating process, true "online" detection is achieved, enabling the immediate detection of defects and providing the possibility for process intervention.

[0119] Intuitive and comprehensive: Infrared thermal imaging provides two-dimensional temperature field information, which can intuitively display the temperature distribution of the entire heating area. It has a wide coverage and no blind spots, making it especially suitable for large-area rapid scanning.

[0120] Dynamic data analysis: To avoid the inability to identify defects due to small temperature differences between the defective and normal areas when the temperature rises to the maximum temperature, the detection device records the data throughout the entire heating process. By cross-referencing the heating rate and the maximum temperature, the defect location is determined, avoiding errors caused by a single signal and ensuring the accuracy of the results.

[0121] Proactive quality control: Through real-time feedback, operators can immediately adjust heating parameters, attempt to "repair" or control defects to prevent them from expanding, or accurately mark the location of defects before the bend cools, which greatly improves the efficiency and yield of subsequent processing and avoids the huge economic losses caused by scrapping the entire bend.

[0122] Non-contact and highly safe: Infrared detection is non-contact, unaffected by electromagnetic interference (with effective protection), and has no radiation risk, making it highly safe.

[0123] High inspection efficiency: It realizes automated non-destructive inspection synchronized with the pipe bending process, and achieves non-destructive inspection of pipe bending without increasing inspection time.

[0124] Data traceability: The thermal imaging data of the entire heating process can be used to establish a product quality database, providing a valuable data foundation for analyzing the causes of defects and optimizing the heating process.

[0125] Furthermore, this invention also provides a method for detecting defects by synchronous infrared thermal imaging during the bending and hot-bending process. Based on the aforementioned device for detecting defects by synchronous infrared thermal imaging during the bending and hot-bending process, the method includes: during the process of induction heating and hot-bending of the straight pipe to be bent using an induction heating coil in a hot-bending production line, simultaneously acquiring thermal images of the straight pipe to be bent using multiple infrared thermal imagers; and analyzing the thermal images using data acquisition and processing equipment to identify defects.

[0126] The beneficial effects of adopting the technical solution of this invention are as follows: The device is integrated into the hot bending pipe production line, and performs infrared thermal imaging detection simultaneously during the induction heating bending process to identify internal defects in real time. While the bent pipe is heated by the medium-frequency induction coil, an infrared thermal imager is used to acquire a two-dimensional temperature field distribution image of the heating area in real time. Defects are identified by analyzing the uniformity of the temperature distribution and the differences in the heating curves in the thermal image. This achieves synchronous, online, and non-destructive testing of hot bending pipes during the induction heating bending process. It enables immediate defect detection, providing the possibility for process intervention.

[0127] Furthermore, the thermal image is a two-dimensional temperature field distribution image of the heating area of ​​the straight tube to be heated.

[0128] The beneficial effects of adopting the above-mentioned further technical solution are as follows: while the bent pipe is heated by the medium-frequency induction coil, a two-dimensional temperature field distribution image of the heated area is acquired in real time using an infrared thermal imager. Defects are identified by analyzing the uniformity of the temperature distribution and the differences in the heating curves in the thermal image. Infrared thermal imaging provides two-dimensional temperature field information, which can intuitively display the temperature distribution of the entire heated area, with wide coverage and no blind spots, making it particularly suitable for large-area rapid scanning.

[0129] Furthermore, the step of analyzing the thermal image using data acquisition and processing equipment to identify defects includes: analyzing the uniformity of temperature distribution and the differences in heating curves in the thermal image using data acquisition and processing equipment to identify defects.

[0130] The beneficial effects of adopting the above-mentioned further technical solution are: by utilizing the differences in heating rate, heat capacity, and thermal conductivity between the defective area and the normal parent material, the abnormal temperature field distribution can be visually displayed through infrared thermal imaging technology, thereby identifying defects such as delamination, inclusions, and cracks in real time. By cross-referencing the heating rate and maximum temperature signals, the defect location can be jointly determined, avoiding errors caused by relying on a single signal and ensuring the accuracy of the results.

[0131] Furthermore, before the step of identifying defects by analyzing the uniformity of temperature distribution and the differences in heating curves in the thermal images using data acquisition and processing equipment, the method includes: analyzing and stitching together thermal images acquired by multiple infrared thermal imagers using data acquisition and processing equipment.

[0132] The beneficial effects of adopting the above-mentioned further technical solutions are: facilitating temperature field analysis. It allows for the intuitive display of abnormal temperature field distribution through infrared thermal imaging technology, thereby enabling real-time identification of defects such as delamination, inclusions, and cracks.

[0133] Furthermore, the step of identifying defects by analyzing the uniformity of temperature distribution and the differences in heating curves in the thermal image using data acquisition and processing equipment includes: acquiring a temperature uniformity threshold and a heating rate threshold using the data acquisition and processing equipment; comparing and analyzing the differences in real-time temperature values ​​and heating rates of different regions in the thermal image using the data acquisition and processing equipment; determining whether the differences in real-time temperature values ​​of different regions in the thermal image exceed the temperature uniformity threshold, and determining whether the differences in heating rates of different regions in the thermal image exceed the heating rate threshold; when the difference in real-time temperature values ​​of a region exceeds the temperature uniformity threshold, and / or the difference in heating rates of that region exceeds the heating rate threshold, the region is determined to be a defect region.

[0134] The beneficial effects of adopting the above-mentioned further technical solution are: by setting a temperature uniformity threshold or a heating rate threshold, when the temperature in a certain area abnormally exceeds the threshold, it is automatically identified as a defect area. By cross-referencing the heating rate and the maximum temperature signals, the defect location is jointly determined, avoiding errors caused by a single signal evaluation and ensuring the accuracy of the results.

[0135] Furthermore, after the step of determining that a region is a defective region when the difference in real-time temperature values ​​of a region exceeds the temperature uniformity threshold and / or the difference in the heating rate of the region exceeds the heating rate threshold, the method further includes: marking, classifying, and recording the location coordinates of the defective region using data acquisition and processing equipment.

[0136] The beneficial effects of adopting the above-mentioned further technical solutions are: marking the defective parts for subsequent processing, avoiding the scrapping of the entire bent pipe, and reducing production costs.

[0137] Furthermore, the step of recording the location coordinates of the defect area through the data acquisition and processing equipment includes: compensating the current position of the defect area according to the advancement rate of the straight pipe to be heated by the data acquisition and processing equipment to obtain the actual location coordinates of the defect area.

[0138] The beneficial effect of adopting the above-mentioned further technical solution is that, since the pipe bend is advanced at a constant speed, the position of a certain fixed position of the pipe body in each frame of thermal image will change as the pipe bend advances, and the collected dynamic temperature field data needs to be compensated according to the advancement rate of the pipe bend.

[0139] Furthermore, the step of compensating for the position of the defect area according to the advancing rate of the straight pipe to be heated by the data acquisition and processing equipment to obtain the actual position coordinates of the defect area includes: subtracting the advancing distance of the straight pipe to be heated from the current position of the defect area by the data acquisition and processing equipment to obtain the actual position coordinates of the defect area.

[0140] The beneficial effect of adopting the above-mentioned further technical solution is that the actual position coordinates of the corresponding pipe body can be obtained by subtracting the advancement distance of the bend from the current position, so as to realize the compensation of the collected dynamic temperature field data according to the advancement rate of the bend.

[0141] Furthermore, after the steps of marking, classifying, and recording the location coordinates of the defective area using the data acquisition and processing equipment, the process includes: transmitting the temperature field distribution, temperature data, and defect alarm information at different locations in the heating area to a display for display using the data acquisition and processing equipment; and controlling the alarm device to sound an alarm when a defective area exists using the data acquisition and processing equipment.

[0142] The beneficial effects of adopting the above-mentioned further technical solution are: the display is used to show the temperature field distribution, temperature data, and defect alarm information at different locations of the heating zone in real time. When a defect is detected, the alarm device can alert the operator.

[0143] Furthermore, after the step of controlling the alarm device to sound an alarm when a defective area exists, the method further includes: adjusting the heating process parameters of the hot bending tube production line through the data acquisition and processing device to suppress the expansion of defects.

[0144] The beneficial effects of adopting the above-mentioned further technical solutions are: providing real-time feedback to operators, enabling them to adjust heating process parameters in a timely manner, suppressing defect expansion, or marking defective areas for subsequent processing, avoiding the scrapping of the entire bent pipe, and reducing production costs.

[0145] Furthermore, after the step of analyzing the thermal image through the data acquisition and processing equipment to identify defects, the method includes: establishing a thermal image data archive of the heating process through the data acquisition and processing equipment.

[0146] The beneficial effects of adopting the above-mentioned further technical solutions are: establishing a thermal imaging data archive of the heating process, providing data support for product quality traceability and process optimization. The recorded thermal imaging data of the entire heating process can be used to establish a product quality database, providing a valuable data foundation for analyzing the causes of defects and optimizing the heating process.

[0147] Furthermore, the step of simultaneously acquiring thermal images of the straight tube to be bent using multiple infrared thermal imagers during the induction heating process of the hot bending tube production line using induction heating coils includes: activating the cooling and protection system through data acquisition and processing equipment during the induction heating process of the straight tube to be bent using induction heating coils, and simultaneously acquiring thermal images of the straight tube to be bent using multiple infrared thermal imagers.

[0148] The beneficial effects of adopting the above-mentioned further technical solution are: the cooling and protection system is used to cool down the thermal imager and protective cover, ensuring stable operation of the equipment. To avoid the defective area becoming undetectable due to small temperature differences between it and the normal area when the temperature rises to the maximum temperature, the detection device records the data throughout the entire heating process.

[0149] Figures 1 to 3 This diagram illustrates a typical defect detected in a thermal image by the synchronous infrared thermal imaging defect detection device for the bending process provided in this embodiment of the invention. Figures 1 to 3 In the images, (a) shows a transverse crack as a bright, high-temperature line. (b) shows a delamination defect as an irregularly shaped, dark (low-temperature) area. (c) shows inclusions as isolated, dot-like or small, blocky low-temperature areas. (d) shows a normal, uniformly heated thermal image. Figure 4The method visually demonstrates the differences in the performance of different types of defects in the temperature field, proving the effectiveness of the basic principle of this method (synchronous infrared thermal imaging defect detection method during pipe bending process).

[0150] In this embodiment, the test object is an X80 grade pipe with an outer diameter of 1219 mm and a wall thickness of 30 mm.

[0151] The implementation process is as follows: System installation: such as Figure 4 As shown, a high-performance infrared thermal imager 4 (operating wavelength 3-5μm or 8-14μm) is fixed on a pipe bending machine. Ensure that the optical axis of the thermal imager (infrared thermal imager 4) forms a suitable angle (e.g., 30°-45°) with the normal to the pipe surface to avoid specular reflection interference. Clean compressed air is connected to the air-cooled piping of the cooling and protection system 5.

[0152] System Calibration: Start the system, perform temperature measurement calibration on the infrared thermal imager 4, and set the parameters in the data acquisition and processing device 9. For example, the temperature uniformity criterion is set as follows: if the temperature at any point in the heating area deviates from the average temperature of the area by more than ±10℃ at any given time, an alarm is triggered; the heating rate criterion is set as follows: if, in the initial stage of heating (e.g., within 10 seconds), the heating rate of a certain area is significantly lower than 5% of the average temperature of the surrounding area, it is determined to be a suspected large-area stratification.

[0153] Synchronous detection: Begin the pipe bending and heating operation. The pipe bending machine pushes the straight pipe (the straight pipe to be bent 1) forward at a constant speed, and the intermediate frequency induction coil (induction heating coil 3) is energized for heating. The field of view of the infrared thermal imager 4 always completely covers the heating zone (induction heating heating zone 6) and the constant temperature zone (induction heating constant temperature zone 7).

[0154] Data Acquisition and Defect Identification: Infrared thermal imager 4 continuously acquires thermal images at a rate of 25 frames per second and transmits them in real time to data acquisition and processing equipment 9. The software displays the temperature field in real time and runs the defect identification algorithm.

[0155] Results Feedback and Processing: During the simmering process, the software detected a vertical bright line at a certain location that was consistently about 20°C higher than the surrounding temperature (e.g., Figure 4 Figure 1 Figure 4 As shown in section a), the system immediately highlighted the area on display 10 and issued an audible and visual alarm. Based on the alarm information, the operator immediately reduced the induction heating power in that area. After the section of the bend cooled, a re-inspection was conducted using conventional ultrasonic testing, based on the location coordinates recorded by the system. This confirmed that the area was a surface micro-crack. Because the crack was detected in time, its propagation was controlled, and the bend, after subsequent localized grinding, was deemed a qualified product, avoiding complete scrapping.

[0156] This embodiment demonstrates that the device of the present invention (synchronous infrared thermal imaging defect detection device for hot bending process) can effectively realize synchronous online defect detection during the hot bending process, thus achieving the objective of the present invention.

[0157] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A device for simultaneous infrared thermal imaging defect detection during the bending and heating process of pipes, characterized in that, include: The hot bending pipe production line, multiple infrared thermal imagers (4) and data acquisition and processing equipment (9) are provided. The hot bending pipe production line is equipped with an induction heating coil (3). Multiple infrared thermal imagers (4) are installed on the hot bending pipe production line and are located near the induction heating coil (3). The data acquisition and processing equipment (9) is electrically connected to the multiple infrared thermal imagers (4).

2. The device for synchronous infrared thermal imaging defect detection during pipe bending process according to claim 1, characterized in that, The hot-bending tube production line is equipped with an annular support, which is parallel to the induction heating coil (3), and multiple infrared thermal imagers (4) are installed on the annular support.

3. The device for synchronous infrared thermal imaging defect detection during pipe bending process according to claim 2, characterized in that, Multiple infrared thermal imagers (4) are installed at equal intervals along the circumference of the annular bracket on the annular bracket.

4. The device for synchronous infrared thermal imaging defect detection during pipe bending process according to claim 1, characterized in that, The hot-bending tube production line is equipped with a cooling and protection system (5) for protecting the infrared thermal imager (4), and the cooling and protection system (5) is set up adjacent to a plurality of the infrared thermal imagers (4).

5. The device for synchronous infrared thermal imaging defect detection during pipe bending process according to claim 4, characterized in that, The cooling and protection system (5) includes a protective cover and a cooling device, wherein the cooling device covers the outside of the infrared thermal imager (4) and the protective cover is placed on the outside of the cooling device.

6. The device for synchronous infrared thermal imaging defect detection during pipe bending process according to claim 5, characterized in that, The cooling device is either an air-cooled cooling device or a liquid-cooled cooling device.

7. The device for synchronous infrared thermal imaging defect detection during pipe bending process according to claim 1, characterized in that, The data acquisition and processing device (9) is electrically connected to a display (10) and an alarm device.

8. The device for synchronous infrared thermal imaging defect detection during pipe bending process according to claim 7, characterized in that, The alarm device is an audible and visual alarm.

9. The device for synchronous infrared thermal imaging defect detection during pipe bending process according to claim 1, characterized in that, The hot-bending production line is equipped with a pipe bending machine, on which a straight pipe (1) to be bent is placed. Multiple infrared thermal imagers (4) and induction heating coils (3) are arranged around the straight pipe (1) to be bent.

10. A synchronous infrared thermal imaging defect detection device for the bending process of a pipe according to claim 9, characterized in that, The angle between the optical axis of the infrared thermal imager (4) and the surface normal of the straight tube (1) to be heated is in the range of 30°-45°.

11. The device for synchronous infrared thermal imaging defect detection during pipe bending process according to claim 9, characterized in that, The outer diameter of the straight pipe (1) to be heated is 1219mm, the wall thickness of the straight pipe (1) to be heated is 30mm, and the straight pipe (1) to be heated is an X80 grade steel pipe.

12. The device for synchronous infrared thermal imaging defect detection during pipe bending process according to claim 9, characterized in that, The fields of view of the multiple infrared thermal imagers (4) cover the heating zone of the straight tube (1) to be heated.

13. The device for synchronous infrared thermal imaging defect detection during pipe bending process according to claim 12, characterized in that, The heating zone of the straight tube (1) to be heated is divided into an induction heating heating zone (6) and an induction heating constant temperature zone (7), both of which are adjacent to the induction heating coil (3).

14. The device for synchronous infrared thermal imaging defect detection during pipe bending process according to claim 1, characterized in that, The infrared thermal imager (4) operates in a wavelength range of 3-5 μm or 8-14 μm.

15. A method for simultaneous infrared thermal imaging defect detection during the bending process of pipes, characterized in that, Based on any one of claims 1 to 14, the device for simultaneous infrared thermal imaging defect detection during the bending process of pipes includes the following method: During the hot bending production line, the straight tubes to be bent are heated by induction heating coils, and thermal images of the straight tubes to be bent are simultaneously collected by multiple infrared thermal imagers. Defects are identified by analyzing thermal images using data acquisition and processing equipment.

16. The method for simultaneous infrared thermal imaging defect detection during pipe bending process according to claim 15, characterized in that, The thermal image is a two-dimensional temperature field distribution image of the heating area of ​​the straight tube to be heated.

17. A method for simultaneous infrared thermal imaging defect detection during pipe bending process according to claim 15, characterized in that, The step of analyzing thermal images using data acquisition and processing equipment to identify defects includes: analyzing the uniformity of temperature distribution and the differences in heating curves in the thermal images using data acquisition and processing equipment to identify defects.

18. The method for simultaneous infrared thermal imaging defect detection during pipe bending process according to claim 17, characterized in that, Before the step of identifying defects by analyzing the uniformity of temperature distribution and the differences in heating curves in thermal images using data acquisition and processing equipment, the method includes: analyzing and stitching together thermal images acquired by multiple infrared thermal imagers using data acquisition and processing equipment.

19. A method for simultaneous infrared thermal imaging defect detection during pipe bending process according to claim 17, characterized in that, The step of identifying defects by analyzing the uniformity of temperature distribution and the differences in heating curves in thermal images using data acquisition and processing equipment includes: Temperature uniformity threshold and heating rate threshold are obtained through data acquisition and processing equipment; By comparing and analyzing the differences in real-time temperature values ​​and heating rates of different regions in the thermal image using data acquisition and processing equipment; The data acquisition and processing equipment determines whether the difference in real-time temperature values ​​of different regions in the thermal image exceeds the temperature uniformity threshold, and whether the difference in heating rate of different regions in the thermal image exceeds the heating rate threshold. When the difference in real-time temperature values ​​of a region exceeds the temperature uniformity threshold, and / or the difference in the heating rate of that region exceeds the heating rate threshold, the region is determined to be a defective region.

20. A method for simultaneous infrared thermal imaging defect detection during pipe bending process according to claim 19, characterized in that, The step of determining a region as a defective region when the difference in real-time temperature values ​​of a region exceeds the temperature uniformity threshold and / or the difference in the heating rate of the region exceeds the heating rate threshold includes: marking, classifying, and recording the location coordinates of the defective region using data acquisition and processing equipment.

21. A method for simultaneous infrared thermal imaging defect detection during pipe bending process according to claim 20, characterized in that, The step of recording the location coordinates of the defect area through the data acquisition and processing equipment includes: compensating the current location of the defect area according to the advancement rate of the straight pipe to be heated by the data acquisition and processing equipment to obtain the actual location coordinates of the defect area.

22. The method for simultaneous infrared thermal imaging defect detection during the bending process of a pipe as described in claim 21, characterized in that, The step of compensating for the location of the defect area with the advancing speed of the straight pipe to be heated by the data acquisition and processing equipment to obtain the actual location coordinates of the defect area includes: subtracting the advancing distance of the straight pipe to be heated from the current location of the defect area by the data acquisition and processing equipment to obtain the actual location coordinates of the defect area.

23. The method for simultaneous infrared thermal imaging defect detection during pipe bending process according to claim 20, characterized in that, After the steps of marking, classifying and recording the location coordinates of the defect area through the data acquisition and processing equipment, the method includes: transmitting the temperature field distribution, temperature data and defect alarm information at different locations of the heating area to the display for display through the data acquisition and processing equipment. When a defective area is found, the alarm device is activated by controlling the data acquisition and processing equipment.

24. The method for simultaneous infrared thermal imaging defect detection during the bending process of a pipe as described in claim 23, characterized in that, The step of controlling the alarm device to sound an alarm when a defective area exists includes: adjusting the heating process parameters of the hot bending tube production line through the data acquisition and processing device to suppress the expansion of defects.

25. The method for simultaneous infrared thermal imaging defect detection during pipe bending process according to claim 15, characterized in that, After the step of analyzing the thermal image through data acquisition and processing equipment to identify defects, the method includes: establishing a thermal image data archive of the heating process through the data acquisition and processing equipment.

26. The method for simultaneous infrared thermal imaging defect detection during pipe bending process according to claim 15, characterized in that, The step of simultaneously acquiring thermal images of the straight tube to be bent using multiple infrared thermal imagers during the induction heating process of the hot bending tube production line using an induction heating coil includes: activating the cooling and protection system through data acquisition and processing equipment during the induction heating process of the straight tube to be bent using an induction heating coil, and simultaneously acquiring thermal images of the straight tube to be bent using multiple infrared thermal imagers.

Images