Ultrasonic phased array detection device and method for weld joint in pressure pipe of power plant

Abstract

The invention discloses an ultrasonic phased array detection device and method for a weld joint in a pressure pipe of a power plant, and relates to the field of weld joint detection. In the scanning driving part, a cross beam provides a transverse track for the detection part and is driven by a telescopic cylinder to move; the wheel sets drive the device to move along the inner wall of the pressure pipe; the permanent magnet suction units are arranged at two ends of the cross beam. The detection part adopts double probes, and high-frequency and low-frequency probes complement each other to detect the welding seam; during detection, the device is firstly put into a pressure pipe, the wheel set drives the device to advance along a circumferential welding seam, and automatic adjustment can be achieved when the device meets uneven positions; when a longitudinal weld joint needs to be detected or a detection position needs to be adjusted, operation is performed through a telescopic cylinder; the high-frequency probe and the low-frequency probe work at the same time during detection, and thick and complex welding seam conditions can be accurately detected. The device is simple and convenient to operate, stable in operation and accurate in detection, and can effectively meet the welding seam detection requirements of the thicker pressure pipe in a power plant.

Description

Technical Field

[0001] The invention relates to the technical field of ultrasonic nondestructive testing, and in particular to an ultrasonic phased array testing device and method for internal welds of a pressure pipe in a power plant. Background Art

[0002] As an important component for transporting high-pressure media, the quality of the welds of the pressure pipes in power plants is directly related to the safe and stable operation of the entire power generation system, and the welds need to be inspected and maintained regularly. For pressure pipes with larger diameters and thicker walls (pipe diameters can reach 10 meters, and the designed plate thickness can reach 52 mm), conventional detection methods are difficult to meet the needs of efficient and accurate detection. In addition, the pressure pipes are deeply buried in concrete structure tunnels, and detection can only be completed from the inside of the pipes. Due to space limitations and complex detection environments, traditional ultrasonic detection devices and methods have many shortcomings. For example, the authorized patent text with authorization announcement number CN101017155 B discloses an ultrasonic phased array detection imaging system for pipe node welds, which is provided with a scanner and an ultrasonic phased array circuit system. The scanner clamps the probe of the ultrasonic phased array circuit system and moves along the outer surface of the branch pipe of the inspected pipe node for detection, but it is more suitable for small-diameter pipes. The diameter of the pressure pipes in power plants is large and there is a lack of support inside the pipes. It is difficult to efficiently complete weld detection in this way. There are also methods that use wall-climbing robots for detection, but there are also many problems. For example, wall-climbing robots require complex steering mechanisms to adjust the detection position, which not only increases the complexity and cost of the equipment, but also easily interferes with the detection when turning, affecting the accuracy of the detection results. At the same time, traditional detection equipment is often bulky, not flexible enough to operate in large-diameter pressure pipes, and has low detection efficiency. In addition, ultrasonic detection is sensitive to environmental interference, and existing detection devices lack means in design to avoid interference from external factors on the transmission and reception of ultrasonic signals, resulting in low detection accuracy. Summary of the invention

[0003] In view of the above problems, an object of the present invention is to provide an ultrasonic phased array detection device and method suitable for internal welds of pressure pipes in power plants, so as to improve detection efficiency and accuracy.

[0004] In order to achieve these purposes and other advantages of the present invention, the present invention provides an ultrasonic phased array detection device for internal welds of a pressure pipe of a power plant, comprising: a detection component for ultrasonically detecting the welds and a scanning drive component for driving the detection component to move along the inner wall of the pressure pipe of the power plant; The scanning drive component comprises: A crossbeam, which forms a transverse motion track of the detection component, the detection component is slidably matched with the crossbeam and is driven by the telescopic cylinder to move transversely; The wheel set is arranged at both ends of the crossbeam to carry the crossbeam, and driven by the power component, drives the inner wall of the crossbeam pressure pipe to move; The suction unit is arranged at both ends of the beam to provide adsorption force so that the scanning drive component adheres to the inner wall of the pressure pipe and does not fall off.

[0005] In the above scheme, the suction unit is used to enable the scanning drive component to move closely inside the pressure pipe without falling, and there is no need to set up a bulky support mechanism inside the pipe, which effectively reduces the overall volume of the device and makes the operation of the detection equipment in the pipe more convenient. When facing a large-diameter pressure pipe, a smaller device can be moved and positioned more flexibly in the pipe, thereby improving the detection efficiency. The design of the crossbeam enables the detection component to move laterally and adjust the detection position and range without changing the direction of movement of the wheel set. The existing detection method using a wall-climbing robot requires a complex steering mechanism to adjust the detection position, and it is easy to interfere with the detection during steering. The present invention simplifies the operation through the cooperation of the crossbeam and the telescopic cylinder, and also improves the stability of the detection component during movement, avoiding shaking or instability caused by frequent steering operations, thereby ensuring the stability of the detection process. The suction unit is located at both ends of the crossbeam away from the detection component, reducing the impact on ultrasonic detection; ultrasonic detection is sensitive to environmental interference. If the suction unit is too close to the detection component, it will interfere with the transmission and reception of ultrasonic signals. The above solution sets the suction unit at a position far away from the detection component, which effectively reduces this interference, allowing the ultrasonic phased array probe to transmit and receive signals more accurately, thereby improving the accuracy of detection and being able to more accurately detect defects in welds and other problems.

[0006] Preferably, the suction unit is a permanent magnetic suction unit. Since the pressure pipe is a steel pipe, permanent magnetic suction can reduce the dependence on electricity, improve endurance, and reduce the risk of power outages. The permanent magnetic unit is relatively electromagnetically stable, which can reduce the interference of traditional electromagnetic suction on ultrasonic phased array probes and signal transmission. Therefore, it is more suitable for use in the complex environment of pressure pipes.

[0007] Preferably, the wheel groups are respectively arranged in front and rear of the direction of travel of the suction unit, and are symmetrical front and back. The wheel groups arranged front and back can provide a wider range of support force, and the force is more uniform. Even if the inner wall is uneven, especially the inner wall of the pipe with a slight arc, the front and rear wheel groups can also provide strong support to maintain the stability of the device. During the movement of the device, due to the pulling of the middle suction unit, the wheel group quickly recovers stability when it rolls over the uneven inner wall, improves the passing capacity, and ensures continuous detection. Since the suction unit is located in the middle and corresponds to the crossbeam, the suction unit provides adsorption force to cling to the inner wall of the pressure pipe, keeps the core of the crossbeam stable, and improves the stability of the detection component.

[0008] Preferably, a roller or a smooth portion is provided at the position where the suction unit contacts the inner wall of the pressure tube. When the device moves on the inner wall of the pressure tube, the suction unit not only provides adsorption force, but also the roller contacts the tube wall, converting sliding friction into rolling friction, greatly reducing friction. The smooth portion contacts the tube wall to reduce friction, thereby improving the smoothness of sliding and reducing jamming.

[0009] Preferably, the suction unit includes a plurality of permanent magnets, which are distributed and arranged in an arc shape to match the arc-shaped inner wall of the pressure tube. The permanent magnets arranged in an arc shape can better adapt to the irregular arc shape of the inner wall of the pressure tube. Even if there are slight unevenness in a local area, the overall adsorption effect can be maintained through the action of other surrounding permanent magnets; at the same time, distributed adsorption can also reduce the bearing pressure of a single permanent magnet and improve the reliability and durability of the permanent magnet.

[0010] Preferably, the wheel set and the suction unit are supported by elastic supporting members and elastically adhere to the inner wall of the pressure tube.

[0011] Preferably, the detection component has a dual-probe detection channel design, the first probe is set at the front end of the forward direction, the second probe is set at the rear end of the forward direction, and either probe is set as a high-frequency probe, and either probe is set as a low-frequency probe. High-frequency probes (such as 10 MHz or above) have higher resolution and can accurately detect tiny defects close to the weld surface. However, due to their relatively weak penetration ability, they may not be able to effectively detect defects in the thickness direction of the entire weld. Therefore, when detecting thicker pipe wall welds, high-frequency probes are mainly used as surface defect detection tools. Low-frequency probes (such as 2-5 MHz) have stronger penetration ability and can detect deep into the weld. They are suitable for detecting thick-walled pressure pipe welds. Although their resolution is relatively low, they can cover a wider detection area, thereby discovering potential defects inside the weld. The present invention is mainly aimed at the detection of welds of pressure pipes in power plants. The designed thickness of the pipe wall can reach 52 mm. The high-frequency probe used has high resolution and can accurately detect tiny defects on the surface of the weld, such as fine cracks and pores, to provide key data for evaluating the surface quality of the weld. The low-frequency probe has strong penetration and can penetrate deep into the weld. Even the welds of thick-walled pressure pipes can be covered for detection, effectively discovering defects such as internal unfusion and large slag inclusions. The two complement each other, allowing the detection component to detect the quality of the weld in all directions and improve the accuracy and reliability of detection. In addition, the weld structure of the pressure pipe in the power plant is complex, such as multi-layer welding, welding of different materials, etc. The dual-probe detection component can meet the detection needs. The high-frequency probe detects surface defects between different welding layers, and the low-frequency probe detects internal defects at the joints of different materials. For example, when detecting the pressure pipe welds welded by stainless steel and carbon steel, the high frequency detects the surface defects of the stainless steel layer, and the low frequency detects the internal defects at the welding interface of the two materials to ensure the quality of complex welds.

[0012] The present invention provides a detection method of an ultrasonic phased array detection device for internal welds of a pressure pipe in a power plant, comprising the following steps: Step 1, placing the assembled detection device into the pressure tube; Step 2, starting the power component, so that the wheel set rolls on the inner wall of the pressure tube under the drive of the power component, driving the entire detection device to move along the circumferential weld of the inner wall of the pressure tube; Step 3, during the movement of the device, the suction unit is tightly attached to the inner wall of the pressure tube through the adsorption force of the permanent magnet to prevent the device from falling; when the inner wall of the pressure tube is uneven, the position is quickly adjusted under the action of the elastic support member with the help of the wheel set symmetrically arranged front and back; at the same time, the roller or smooth part on the suction unit contacts the inner wall of the pressure tube to reduce friction; Step 4: When it is necessary to adjust the transverse position of the detection component or to detect the longitudinal weld, the telescopic cylinder is started, and the telescopic cylinder drives the detection component to move transversely on the beam, thereby adjusting the detection position and range; Step 5: During the detection process, the high-frequency probe and the low-frequency probe are operated simultaneously, wherein the high-frequency probe detects the surface of the weld, and the low-frequency probe detects the inside of the weld; for multi-layer welds, the high-frequency probe is used to detect the surfaces between different welding layers, and the low-frequency probe is used to detect the joints of different materials; Step 6: During or after the test, analyze and process the test data.

[0013] The present invention has at least the following beneficial effects: The present invention adopts a suction unit so that the scanning drive component can move closely inside the pressure pipe without falling, and there is no need to set up a bulky support mechanism inside the pipe, which effectively reduces the overall volume of the device and makes the operation of the detection equipment in the pipe more convenient. When facing a large-diameter pressure pipe, a smaller device is easy to carry and can be moved and positioned more flexibly in the pipe, thereby improving the detection efficiency. The design of the crossbeam enables the detection component to move laterally and adjust the detection position and range without changing the movement direction of the wheel group. The traditional detection method using a wall-climbing robot requires a complex steering mechanism to adjust the detection position, while the present invention simplifies the operation through the cooperation of the crossbeam and the telescopic cylinder, and also improves the stability of the detection component during movement, avoiding shaking or instability caused by frequent steering operations, thereby ensuring the stability of the detection process. The suction unit is located at both ends of the crossbeam away from the detection component, reducing the impact on ultrasonic detection; ultrasonic detection is sensitive to environmental interference, and if the suction unit is too close to the detection component, it will interfere with the transmission and reception of ultrasonic signals. The above solution sets the suction unit far away from the detection component, which effectively reduces the interference, allowing the ultrasonic phased array probe to transmit and receive signals more accurately, thereby improving the accuracy of detection. By improving stability and reducing interference, defects in welds and other problems can be detected more accurately.

[0014] Other advantages, objectives and features of the present invention will be embodied in part through the following description, and in part will be understood by those skilled in the art through study and practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 The ultrasonic phased array detection device for the internal weld of a pressure pipe in a power plant of the present invention; Figure 2 It is a structural schematic diagram of the crossbeam of the present invention; Figure 3 It is a schematic diagram of the bottom structure of the suction unit of the present invention; Figure 4 It is a structural schematic diagram of the detection component of the present invention; Figure 5 It is a schematic diagram of the operating structure of the device of the present invention inside the pressure pipe; Figure 6 The schematic diagram is a schematic diagram of the sampling inspection operation of the annular seam and the longitudinal seam by the device of the present invention. DETAILED DESCRIPTION

[0016] The present invention is further described in detail below in conjunction with embodiments so that those skilled in the art can implement the invention with reference to the description.

[0017] like Figure 1~Figure 5As shown, the present invention provides an ultrasonic phased array detection device for internal welds of a power plant pressure pipe, comprising: a detection component 50 for ultrasonically detecting the welds and a scanning drive component for driving the detection component 50 to move along the inner wall of the power plant pressure pipe 90; The scanning drive component comprises: The crossbeam 10 constitutes a transverse motion track of the detection component 50. The detection component 50 is slidably matched with the crossbeam 10 and is driven by the telescopic cylinder 70 to move transversely; Figure 1 and 2 As shown, the detection component 50 is arranged inside the detection box 60, and a slide 80 is fixed on the top of the detection box 60. The slide 80 is slidably matched with the crossbeam 10. The telescopic cylinder 70 is connected to the side of the detection box 60. The telescopic cylinder can push the detection component 50 connected to the detection box 60 to move horizontally. Preferably, a plurality of arc-shaped protrusions 101 are arranged on the surface of the crossbeam along the length direction. The slide groove 801 of the slide 80 is adapted to the shape of the crossbeam 10. The two are tightly slidably matched to improve the sliding stability, which is smoother than the traditional dovetail groove matching method. The telescopic cylinder 70 can be an electric telescopic cylinder, a pneumatic telescopic cylinder, or a hydraulic telescopic cylinder.

[0018] The wheel set 30 is arranged at both ends of the cross beam 10 to support the cross beam, and driven by the power component, drives the cross beam 10 to move along the inner wall of the pressure pipe; Figure 1 As shown, mounting bridges 40 are respectively provided at both ends of the crossbeam 10, and the wheel set 30 is rotatably mounted on the mounting bridge 40 to support and drive the crossbeam 10 to move. The preferred wheel set uses a hub motor, which integrates the power component and the wheel into a whole, effectively reducing the volume, and is very suitable for use in the present invention. Preferably, the hub motor can be powered by an external power source, for example, a power source such as a battery is installed on a trolley and connected to the hub motor through a power supply line, which can effectively reduce the load of the device.

[0019] The suction unit 20 is arranged at both ends of the beam 10 to provide suction force so that the scanning drive component adheres to the inner wall of the pressure pipe and does not fall off. Figure 1 As shown, the suction unit 20 is installed and fixed below the mounting bridge 40 , and the suction force provided by the suction unit 20 pulls the crossbeam and the detection component so that they are close to the inner wall of the pressure pipe.

[0020] During implementation, the device of the present invention is moved into the pressure pipeline of the power plant. When sampling and testing the annular seam, the crossbeam 10 spans the annular weld, the wheel group and the suction unit are respectively located on both sides of the annular weld to be tested, and the power component drives the wheel group to make annular wall movement along the inside of the pressure pipe, and the position of the detection component is adjusted by the telescopic cylinder so that the ultrasonic phased array detection probe of the detection component 50 is aligned with the weld to perform accurate detection. When testing the longitudinal seam, the driving wheel group moves the crossbeam to the position corresponding to the longitudinal seam, and then drives the detection component to move horizontally through the telescopic cylinder to detect the longitudinal seam.

[0021] In the above embodiment, the suction unit is used to enable the scanning drive component to move closely inside the pressure pipe without falling, and there is no need to set up a bulky support mechanism inside the pipe, which effectively reduces the overall volume of the device and makes the operation of the detection equipment in the pipe more convenient. When facing a large-diameter pressure pipe, a smaller device can be moved and positioned more flexibly in the pipe, thereby improving the detection efficiency. The design of the crossbeam enables the detection component to move laterally and adjust the detection position and range without changing the direction of movement of the wheel set. Compared with the existing detection method using a wall-climbing robot, which requires a complex steering mechanism to adjust the detection position and is easy to interfere with the detection during steering, the present invention simplifies the operation through the cooperation of the crossbeam and the telescopic cylinder, and also improves the stability of the detection component during movement, avoiding shaking or instability caused by frequent steering operations, thereby ensuring the stability of the detection process. The suction unit is located at both ends of the crossbeam away from the detection component, reducing the impact on ultrasonic detection; ultrasonic detection is sensitive to environmental interference. If the suction unit is too close to the detection component, it will interfere with the transmission and reception of ultrasonic signals. The above solution sets the suction unit at a position far away from the detection component, which effectively reduces this interference, allowing the ultrasonic phased array probe to transmit and receive signals more accurately, thereby improving the accuracy of detection and being able to more accurately detect defects in welds and other problems.

[0022] In a preferred embodiment, Figure 1As shown, the suction unit is a permanent magnetic suction unit. Considering that the pressure pipe of a power plant is usually made of steel pipe, the permanent magnetic suction unit uses the magnetism of the permanent magnet itself to generate adsorption force, so that it can be firmly adsorbed on the inner wall of the pressure pipe, which can reduce the dependence on electricity, improve endurance, and reduce the risk of power outages. The electromagnetic of the permanent magnetic unit is relatively stable, which can reduce the interference of traditional electromagnetic suction on ultrasonic phased array probes and signal transmission. Therefore, it is more suitable for use in the complex environment of pressure pipes. Compared with the traditional method of relying on electricity to generate suction, the first advantage of the permanent magnetic suction unit is that it reduces the dependence on electricity. In the actual detection process, this means that there is no need to equip the suction unit with a large amount of additional power supply equipment, which not only reduces the complexity and cost of the equipment, but also greatly improves the endurance of the detection device. For example, in a relatively offset or long pressure pipe, it is not convenient to use a wire power supply or a battery, and the detection device using a permanent magnetic suction unit can operate more reliably and reduce the risk of detection interruption due to power outages. In addition, the electromagnetic characteristics of the permanent magnetic unit are relatively stable. Traditional electromagnetic suction equipment will produce complex electromagnetic field changes when working. These changes may interfere with nearby ultrasonic phased array probes and signal transmission processes, thereby affecting the accuracy of the detection results. The permanent magnetic suction unit can effectively reduce this interference due to its stable magnetic field characteristics. In a complex detection environment such as pressure pipelines, ultrasonic phased array probes need to accurately transmit and receive signals to detect tiny defects in welds. The application of permanent magnetic suction units enables ultrasonic phased array probes to work in a relatively stable electromagnetic environment, thereby improving the accuracy and reliability of detection, ensuring that various defects in welds can be detected more accurately, and providing stronger guarantees for the safe operation of pressure pipes in power plants.

[0023] In a preferred embodiment, Figure 1 As shown, the wheel set 30 is respectively arranged in front and rear of the direction of travel of the suction unit 20, and is symmetrical front and back. The wheel sets arranged front and back can provide a wider range of support force, and the force is more uniform. Even if the inner wall is uneven, especially the inner wall of the pipe with a slight arc, the front and rear wheel sets can also provide strong support to maintain the stability of the device. During the movement of the device, due to the pulling of the suction unit in the middle, the wheel set quickly recovers stability when it rolls over the uneven inner wall, improves the passing capacity, and ensures continuous detection. Moreover, since the suction unit is located in the middle and corresponds to the crossbeam, the suction unit provides adsorption force to cling to the inner wall of the pressure pipe, keeps the core of the crossbeam stable, and improves the stability of the detection component.

[0024] In a preferred embodiment, Figure 1 and 5As shown, when the device moves on the inner wall of the pressure tube, the suction unit is close to the inner wall (ideally close but not in contact) to provide suction force, but because the inner wall is not complete, regular and flat, the suction unit 20 may contact the inner wall. In the present invention, a roller or a rounded portion (which can be the entire bottom surface or a protruding part of the bottom surface) is provided on the surface where the suction unit 20 contacts the inner wall of the pressure tube 90. When the roller contacts the tube wall, the sliding friction is converted into rolling friction, which greatly reduces the friction force, or the rounded portion contacts the tube wall to reduce friction, thereby improving the smoothness of sliding and reducing jamming. Preferably, as Figure 3 The figure shows an example of a rounded portion, in which the rounded portion is a rounded arc-shaped ridge 202 arranged along the travel direction, and a plurality of permanent magnets 201 are arranged between the arc-shaped ridges 202 to avoid direct contact with the inner wall of the pressure tube and wear. When replaced with a roller, the arc-shaped ridge 202 in the figure can be set as a roller such as a roller or a ball. Compared with a roller, the arc-shaped ridge 202 is more solid and not easy to be damaged. More importantly, it can reduce deflection so that the device does not deviate when traveling.

[0025] In a preferred embodiment, Figure 2 , 3 As shown in FIG. 5 , the suction unit 20 includes a plurality of permanent magnets, and the plurality of permanent magnets 201 are distributed and arranged in an arc shape, thereby matching the arc-shaped inner wall of the pressure tube. Figure 3 FIG. 2 is a schematic diagram of the bottom surface structure of the suction unit. The permanent magnets 201 are fixed on the bottom surface of the suction unit in an arranged and distributed manner. Figure 2 As shown, the bottom surface of the suction unit 20 is arc-shaped. Such arc-shaped distributed arrangement of permanent magnets can better adapt to the irregular arc shape of the inner wall of the pressure tube. Even if there are slight unevenness in the local area, the overall adsorption effect can be maintained through the action of other surrounding permanent magnets. At the same time, distributed adsorption can also reduce the bearing pressure of a single permanent magnet, improve the reliability and durability of the permanent magnet, and facilitate replacement.

[0026] In a preferred embodiment, the wheel set and the suction unit are supported by an elastic support member, and elastically adhere to the inner wall of the pressure tube. Figure 2 As shown, the leaf spring 401 is an elastic support member, which is installed in an arc shape at the bottom of the mounting bridge 40, and the suction unit 20 is installed on the leaf spring 401. Compared with other elastic support members such as springs, the leaf spring 401 is used here so that the suction unit and the leaf spring have a larger bonding area, thereby improving the stability of the suction unit, reducing the offset, and having little impact on the detection component. The leaf spring 401 has a shock-absorbing and buffering effect. When the inner wall is uneven and produces ups and downs or vibrations, the suction unit 20 provides adsorption force to make the detection component quickly restore stability, and distributes force to the front and rear wheel groups through the leaf spring and the mounting bridge 40, so that the wheel groups are pressed against the inner wall to keep the device stable.

[0027] like Figure 2 As shown, the elastic support member of the wheel set is a spring shock absorber 302, and the wheel 301 of the wheel set is installed on the spring shock absorber 302. Preferably, the wheel 301 is a rubber wheel, or a rubber layer is provided on the surface of the wheel.

[0028] In a preferred embodiment, Figure 4 As shown, the detection component 50 has a dual-probe detection channel design, the first probe 502 is set at the front end of the forward direction (left side of the figure), and the second probe 501 is set at the rear end of the forward direction (right side of the figure), and either probe is set as a high-frequency probe, and either probe is set as a low-frequency probe. High-frequency probes (such as 10MHz and above) have higher resolution and can accurately detect tiny defects close to the weld surface. However, due to their relatively weak penetration ability, they may not be able to effectively detect defects in the thickness direction of the entire weld. Therefore, when detecting thicker pipe wall welds, high-frequency probes are mainly used as surface defect detection tools. Low-frequency probes (such as 2-5MHz) have stronger penetration ability and can penetrate deep into the weld for detection. They are suitable for detecting thick-walled pressure pipe welds. Although their resolution is relatively low, they can cover a wider detection area, thereby discovering potential defects inside the weld. The present invention is mainly aimed at the detection of welds of pressure pipes in power plants. The designed thickness of the pipe wall can reach 52mm. The high-frequency probe used has high resolution and can accurately detect tiny defects on the weld surface, such as fine cracks and pores, to provide key data for evaluating the surface quality of the weld. The low-frequency probe has strong penetration and can penetrate deep into the weld. Even thick-walled pressure pipe welds can be covered for detection, and internal defects such as unfused welds and large slag inclusions can be effectively found. The two complement each other, allowing the detection component to detect weld quality in all directions and improve detection accuracy and reliability. In addition, the weld structure of the pressure pipe in a power plant is complex, such as multi-layer welding, welding of different materials, etc. The dual-probe detection component can meet the detection needs. The high-frequency probe detects surface defects between different welding layers, and the low-frequency probe detects internal defects at the joint of the pressure pipe section. For example, when detecting pressure pipe welds welded with stainless steel and carbon steel, the high frequency detects surface defects of the stainless steel layer, and the low frequency detects internal defects at the welding interface of the two materials to ensure the quality of complex welds. In a preferred embodiment, Figure 4 As shown, the design of the detection box 60 can solve the problem that the probe easily touches the wall inside the arc of the pressure tube. The first probe and the second probe are installed inside the detection box 60 and keep a certain distance from the bottom surface of the detection box 60, such as 0.1~5 cm. The bottom side frame of the detection box 60 is provided with a rubber plate, the front and rear sides are the first rubber plate 601, and the left and right sides are the second rubber plate 602. The rubber plate can produce a certain deformation and fit closely to the inner wall of the pressure tube, and can maintain the distance between the probe and the inner wall to prevent the probe from directly contacting the inner wall. The rubber plate can also reduce the influence of vibration caused by friction on detection.

[0029] In a preferred embodiment, Figure 4As shown, in order to further improve the ultrasonic transmission efficiency, reduce the wear of the probe and ensure the detection accuracy, a container such as a tank 10 is provided to load a coupling agent (such as water or glycerin). The tank 10 is inverted on the top of the detection box 60 and communicated with the inside of the detection box 60 through a quantitative valve. The quantitative valve can allow the coupling agent to be quantitatively added to the inside of the detection box 60. At this time, the coupling agent fills the inside of the detection box 60 and fills the gap between the probe and the inner wall of the pressure tube, thereby improving the ultrasonic transmission efficiency, reducing the wear of the probe, and improving the detection accuracy. Further preferably, a guide tube is provided inside the detection box 60, and the guide tube is connected to the quantitative valve of the tank 10 to guide the coupling agent directly to the front of the probe. The coupling agent flows out from the guide tube and directly enters the gap between the probe and the inner wall. This method can apply the coupling agent more accurately and economically. During the movement of the device, the inside of the detection box 60 is in a relatively closed state. The first rubber plate 601 and the second rubber plate 60 can scrape the coupling agent on the inner wall to keep the coupling agent inside the detection box to reduce losses. Example

[0030] refer to Figure 6 The pressure pipe section of the power plant required to be inspected in the present invention is formed by welding several sections of steel pipes. Among the crossed horizontal and vertical lines in the figure, the horizontal line is the longitudinal weld, the vertical line is the circumferential weld, and the bold line is the weld to be inspected.

[0031] like Figure 5 As shown, an example of a detection method of an ultrasonic phased array detection device for internal welds of a pressure pipe in a power plant according to the present invention comprises: Step 1: Place the assembled detection device into the pressure tube 90; Figure 5 As shown, at this time, the crossbeam 10 spans one or several circumferential welds 901 , and the suction unit 20 is close to the inner wall of the pressure pipe 90 .

[0032] Step 2, start the power component, so that the wheel set 30 rolls on the inner wall of the pressure tube 90 under the drive of the power component, driving the entire detection device to move along the circumferential weld 901 on the inner wall of the pressure tube.

[0033] Step 3, during the movement of the device, the suction unit 20 is used to adhere to the inner wall of the pressure tube through the adsorption force of the permanent magnet to prevent the device from falling; when the inner wall of the pressure tube is uneven, the position is quickly adjusted under the action of the elastic support with the help of the wheel set 30 symmetrically arranged front and back; at the same time, the roller or smooth part on the suction unit contacts the inner wall of the pressure tube to reduce friction.

[0034] Step 4, when the lateral position of the detection component 50 needs to be adjusted, the telescopic cylinder 70 is started, and the telescopic cylinder drives the detection component 50 to move laterally on the beam, thereby adjusting the detection position and range; Figure 5As shown, when the longitudinal weld 902 needs to be inspected, the driving device moves to the position where the cross beam 10 corresponds to the longitudinal weld 902 (based on the coverage of the probe), and then the telescopic cylinder 70 is started to drive the detection component 50 to move horizontally, thereby ultrasonically inspecting the longitudinal weld.

[0035] Step 5: Since the plate thickness of the pressure pipe section is 52 mm and a multi-layer welding process is adopted, the high-frequency probe and the low-frequency probe are operated simultaneously during the detection process, wherein the high-frequency probe detects the surface of the weld and the low-frequency probe detects the inside of the weld; the high-frequency probe is used to detect the surfaces between different welding layers, and the low-frequency probe is used to detect the joints of different materials; Step 6: During the detection process, the detection data is transmitted to the host computer (such as a computer) in real time, or after the detection is completed, the detection data is uploaded to the host computer, and then the detection data is analyzed and processed.

[0036] Although the embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and the embodiments. They can be applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily realized.

Claims

1. An ultrasonic phased array detection device for internal welds of pressure pipes in power plants, characterized in that: include: A detection component (50) for ultrasonically detecting a weld and a scanning drive component for driving the detection component (50) to move along the inner wall of a power plant pressure pipe (90); The scanning drive component comprises: A crossbeam (10) which forms a transverse motion track of the detection component (50); the detection component (50) is slidably matched with the crossbeam (10) and is driven by the telescopic cylinder (70) to move transversely; A wheel assembly (30) is arranged at both ends of the cross beam (10) to support the cross beam, and driven by a power component to drive the cross beam (10) to move along the inner wall of the pressure pipe; The suction unit (20) is arranged at both ends of the crossbeam (10) and provides a suction force so that the scanning drive component adheres to the inner wall of the pressure pipe and does not fall off.

2. The ultrasonic phased array detection device for internal welds of pressure pipes in power plants according to claim 1, characterized in that: The suction unit is a permanent magnetic suction unit; the wheel sets (30) are respectively arranged in front and rear of the travel direction of the suction unit (20), and are symmetrical front to back.

3. The ultrasonic phased array detection device for internal welds of pressure pipes in power plants according to claim 1, characterized in that: A roller or a smooth portion is provided on the surface where the suction unit (20) contacts the inner wall of the pressure tube (90).

4. The ultrasonic phased array detection device for internal welds of pressure pipes in power plants according to claim 1, characterized in that: The rounded portion is a rounded, smooth arc-shaped ridge (202) arranged along the traveling direction, and a plurality of permanent magnets (201) are arranged between the arc-shaped ridges (202).

5. The ultrasonic phased array detection device for internal welds of pressure pipes in power plants according to claim 1, characterized in that: The suction unit (20) comprises a plurality of permanent magnets, and the plurality of permanent magnets (201) are distributed and arranged in an arc shape, thereby matching the arc-shaped inner wall of the pressure pipe.

6. The ultrasonic phased array detection device for internal welds of pressure pipes in power plants according to claim 1, characterized in that: The detection component (50) has a dual-probe detection channel, the first probe (502) is arranged at the front end in the forward direction, the second probe (501) is arranged at the rear end in the forward direction, any one of the probes is arranged as a high-frequency probe, and any one of the probes is arranged as a low-frequency probe.

7. The ultrasonic phased array detection device for internal welds of a pressure pipe in a power plant according to any one of claim 6, characterized in that: The bottom side frame of the detection box (60) is provided with a rubber plate, the front and rear sides are first rubber plates (601), and the left and right sides are second rubber plates (602). The first probe and the second probe are installed inside the detection box (60) and maintain a certain distance from the bottom surface of the detection box (60).

8. The ultrasonic phased array detection device for internal welds of a pressure pipe in a power plant according to any one of claim 7, characterized in that: A tank (10) loaded with coupling agent is also provided, and the tank (10) is inverted on the top of the detection box (60) and communicated with the interior of the detection box (60) via a quantitative valve.

9. The ultrasonic phased array detection device for internal welds of a pressure pipe in a power plant according to any one of claim 8, characterized in that: The detection box (60) is provided with a guide tube inside, the guide tube being connected to the quantitative valve to guide the coupling agent directly to the front of the probe.

10. A detection method for an ultrasonic phased array detection device for internal welds of a pressure pipe in a power plant according to any one of claims 1 to 9, characterized in that: include: Step 1, placing the assembled detection device into the pressure tube (90); Step 2, starting the power component, so that the wheel set (30) rolls on the inner wall of the pressure tube (90) under the drive of the power component, driving the entire detection device to move along the circumferential weld (901) on the inner wall of the pressure tube; Step 3, during the movement of the device, the suction unit (20) is used to provide suction force to cling to the inner wall of the pressure tube to prevent the device from falling; when the inner wall of the pressure tube is uneven, the position is quickly adjusted under the action of the elastic support member by means of the wheel set (30) symmetrically arranged front and rear; at the same time, the roller or smooth part on the suction unit contacts the inner wall of the pressure tube to reduce friction; Step 4, when performing circumferential weld inspection, when it is necessary to adjust the lateral position of the detection component (50), the telescopic cylinder (70) is started, and the telescopic cylinder drives the detection component (50) to move transversely on the crossbeam, thereby adjusting the detection position and range; when it is necessary to inspect the longitudinal weld (902), the drive device moves until the crossbeam (10) corresponds to the longitudinal weld (902), and then the telescopic cylinder (70) is started to drive the detection component (50) to move transversely, thereby performing ultrasonic inspection on the longitudinal weld; Step 5: During the detection process, the high-frequency probe and the low-frequency probe are operated simultaneously, wherein the high-frequency probe detects the surface of the weld, and the low-frequency probe detects deep into the weld; the high-frequency probe is used to detect the surfaces between different welding layers, and the low-frequency probe is used to detect the joints of different materials.

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