CN116008387A - Storage tank bottom plate detection device and detection method - Google Patents

Abstract

The invention provides a storage tank bottom plate detection device and a detection method, wherein the storage tank bottom plate detection device comprises: the magnetic field sensor comprises a first outer ring magnet, a second outer ring magnet, an inner ring magnet, an annular exciting coil, an isolation layer, a multi-section annular receiving coil and a Hall element, wherein the second outer ring magnet is sleeved on the outer side of the inner ring magnet, the first outer ring magnet is sleeved on the outer side of the second outer ring magnet, the annular exciting coil is wound on the outer sides of the second outer ring magnet and the inner ring magnet, the multi-section annular receiving coil is wound on the first outer ring magnet along the circumferential direction of the first outer ring magnet, the isolation layer is arranged between the first outer ring magnet and the second outer ring magnet, and the Hall element is arranged in the isolation layer. The organic fusion of the magnetic flux leakage detection and electromagnetic ultrasonic guided wave detection technology is realized. The single detection range is large, and the storage tank bottom plate with huge area can be conveniently and comprehensively and rapidly inspected. The detection efficiency of the storage tank bottom plate is improved, and the consumption of manpower and material resources is reduced.

Description

A storage tank bottom plate detection device and detection method

technical field

The invention relates to the technical field of storage tank detection, in particular to a storage tank bottom plate detection device and detection method.

Background technique

Large-scale oil storage tanks are important basic key equipment to protect oil and gas resources. Once corrosion occurs, not only the structural strength of the storage tanks will be reduced, but in severe cases, fire and explosion accidents will be caused, resulting in huge economic losses. In order to ensure the safe operation of the storage tank, in the actual operation process, the storage tank needs to be regularly shut down for maintenance. At present, more and more attention is paid to the structural health inspection and monitoring of storage tanks, and the bottom plate of storage tanks is the focus of attention. At present, traditional detection methods such as magnetic flux leakage, longitudinal wave ultrasonic thickness measurement, eddy current detection, and magnetic particle detection are generally used for the detection of storage tank bottom plates. These detection methods can only detect the plate surface below the sensor, and the single detection range is small and the efficiency is very high. Low.

In actual work, it is difficult to conduct a comprehensive and rapid inspection of the large-area storage tank floor using the above non-destructive testing methods.

Contents of the invention

The technical problem to be solved by the present invention is to provide a detection device and detection method for the bottom plate of a storage tank aiming at the deficiencies of the prior art.

The technical solution of the present invention to solve the above-mentioned technical problems is as follows: a detection device for the bottom plate of a storage tank, comprising: a first outer ring magnet, a second outer ring magnet, an inner ring magnet, an annular excitation coil, an isolation layer, a multi-segment annular receiving coil, a The second outer ring magnet is sleeved on the outside of the inner ring magnet, the first outer ring magnet is sleeved on the outside of the second outer ring magnet, and the annular excitation coil is wound on the On the outside of the second outer ring magnet and the inner ring magnet, multiple segments of the annular receiving coil are wound on the first outer ring magnet along the circumferential direction of the first outer ring magnet, and the isolation layer is installed on the outer ring magnet. Between the first outer ring magnet and the second outer ring magnet, the Hall element is installed in the isolation layer.

The beneficial effect of adopting the technical solution of the present invention is that a wide range of storage tank floor corrosion detection can be realized without direct contact or ultrasonic coupling, the structure of the annular permanent magnet is rationally designed, and the annular excitation coil, annular receiving coil and Hall Components to realize the organic integration of magnetic flux leakage detection and electromagnetic ultrasonic guided wave detection technology. The single detection range is large, which is convenient for comprehensive and rapid inspection of the large-area storage tank bottom plate. It does not need to pre-treat the surface of the tested sample and apply couplant, and has low requirements on the surface of the tested structure, realizing a wide range of full-angle areas. Composite detection and positioning of corrosion defects in the interior solves the technical problem that the existing technology cannot realize the comprehensive detection of ultrasonic guided wave and magnetic flux leakage on the tested material, resulting in incomplete detection. Improve the detection efficiency of the bottom plate of the storage tank and reduce the consumption of manpower and material resources. The use of electromagnetic ultrasonic guided wave transducers can excite omnidirectional horizontal shear guided waves, which will generate echoes after interacting with corrosion defects. Through the collection of echo signals by the outer ring circumferential receiving coil, a certain range can be accurately located Corrosion defects in the inner tank floor.

Further, the first outer ring magnet, the second outer ring magnet and the inner ring magnet are arranged coaxially.

The beneficial effect of adopting the above further technical solution is: the material used to magnetize the structure to be tested and generate a magnetic field signal inside the structure to be tested.

Further, the annular excitation coil is wound outside the combination formed by the second outer ring magnet and the inner ring magnet.

The beneficial effect of adopting the above-mentioned further technical solution is that: the second outer ring magnet and the inner ring magnet provide radially opposite bias static magnetic fields at the bottom of the storage tank to excite omnidirectionally propagating horizontal shear guided waves. That is, the second outer ring magnet, the inner ring magnet, and the annular excitation coil wound on the second outer ring magnet and the inner ring magnet assembly cooperate with each other to generate electromagnetic ultrasonic guided waves. The static bias magnetic field perpendicular to the tested object is provided by the second outer ring magnet and the inner ring magnet, and the annular excitation coil is connected with a high-frequency excitation current to generate radially distributed induced eddy currents on the upper surface of the bottom plate of the tested storage tank. The induced eddy currents Under the action of the static bias magnetic field, the high-frequency vibration of the particle on the surface of the plate is induced by the Lorentz force, and then the horizontal shear guided wave propagating in all directions is excited.

Further, the isolation layer includes: a pair of silicon steel sheets and an epoxy resin intermediate layer, the pair of silicon steel sheets are connected to the first outer ring magnet and the second outer ring magnet in one-to-one correspondence, and the ring An epoxy resin intermediate layer is installed between a pair of said silicon steels, and said Hall element is located at the bottom of said epoxy resin intermediate layer.

The beneficial effect of adopting the above-mentioned further technical scheme is: an isolation layer is set between the first outer ring magnet and the second outer ring magnet, the lower part is a uniform magnetic field area, and a magnetic field measurement sensor such as a Hall element is arranged in the middle of the uniform magnetic field area. It is used to detect whether there is a magnetic field signal outside the structure to be tested, and the magnetic flux leakage detection of corrosion defects can be realized. The isolation layer is composed of silicon steel sheets on both sides and an epoxy resin intermediate layer. The silicon steel sheets surrounding the first outer ring magnet and the second outer ring magnet are used as high magnetic permeability materials to shield the magnetic field between them and prevent mutual Signal interference affects the accuracy of corrosion detection.

Further, the N pole of the first outer ring magnet is located above the S pole, the N pole of the second outer ring magnet is located below the S pole, and the N pole of the inner ring magnet is located above the S pole.

The beneficial effect of adopting the above-mentioned further technical solution is that a wide range of storage tank floor corrosion detection can be realized without direct contact or ultrasonic coupling, the structure of the ring permanent magnet is reasonably designed, and the ring excitation coil, the ring receiving coil and the Hall Components to realize the organic integration of magnetic flux leakage detection and electromagnetic ultrasonic guided wave detection technology. The single detection range is large, which is convenient for comprehensive and rapid inspection of the large-area storage tank bottom plate. It does not need to pre-treat the surface of the tested sample and apply couplant, and has low requirements on the surface of the tested structure, realizing a wide range of full-angle areas. Composite detection and positioning of corrosion defects in the interior solves the technical problem that the existing technology cannot realize the comprehensive detection of ultrasonic guided wave and magnetic flux leakage on the tested material, resulting in incomplete detection. Improve the detection efficiency of the bottom plate of the storage tank and reduce the consumption of manpower and material resources. The use of electromagnetic ultrasonic guided wave transducers can excite omnidirectional horizontal shear guided waves, which will generate echoes after interacting with corrosion defects. Through the collection of echo signals by the outer ring circumferential receiving coil, a certain range can be accurately located Corrosion defects in the inner tank floor.

Further, top and bottom ends of the first outer ring magnet, the second outer ring magnet, and the inner ring magnet are respectively located on the same plane.

The beneficial effect of adopting the above further technical solution is that it is convenient for installation and maintenance of the detection device for the bottom plate of the storage tank, it is convenient for storage and transportation of the detection device for the bottom plate of the storage tank, and the structure of the detection device for the bottom plate of the storage tank is compact.

Further, the first outer ring magnet, the second outer ring magnet and the inner ring magnet are all ring structures.

The beneficial effect of adopting the above further technical solution is that it is convenient for installation and maintenance of the detection device for the bottom plate of the storage tank, it is convenient for storage and transportation of the detection device for the bottom plate of the storage tank, and the structure of the detection device for the bottom plate of the storage tank is compact.

In addition, the present invention also provides a storage tank bottom plate detection method, based on a storage tank bottom plate detection device described in any one of the above, a storage tank bottom plate detection method includes:

S1. The detection device for the bottom plate of the storage tank is close to the bottom plate of the storage tank to be detected;

S2. The annular excitation coil excites the horizontal shear guided wave propagating along the 360° direction, and performs corrosion detection on the bottom plate of the storage tank;

S3. The annular receiving coil analyzes the reflected guided wave signal, and locates the corrosion defect within the detection range;

S4. The Hall element analyzes the magnetic flux leakage signal of the bottom plate of the storage tank to be detected, and obtains the corrosion information of the bottom plate of the storage tank to be detected under the detection device for the bottom plate of the storage tank.

The beneficial effect of adopting the technical solution of the present invention is that a wide range of storage tank floor corrosion detection can be realized without direct contact or ultrasonic coupling, the structure of the annular permanent magnet is rationally designed, and the annular excitation coil, annular receiving coil and Hall Components to realize the organic integration of magnetic flux leakage detection and electromagnetic ultrasonic guided wave detection technology. The single detection range is large, which is convenient for comprehensive and rapid inspection of the large-area storage tank bottom plate. It does not need to pre-treat the surface of the tested sample and apply couplant, and has low requirements on the surface of the tested structure, realizing a wide range of full-angle areas. Composite detection and positioning of corrosion defects in the interior solves the technical problem that the existing technology cannot realize the comprehensive detection of ultrasonic guided wave and magnetic flux leakage on the tested material, resulting in incomplete detection. Improve the detection efficiency of the bottom plate of the storage tank and reduce the consumption of manpower and material resources. The use of electromagnetic ultrasonic guided wave transducers can excite omnidirectional horizontal shear guided waves, which will generate echoes after interacting with corrosion defects. Through the collection of echo signals by the outer ring circumferential receiving coil, a certain range can be accurately located Corrosion defects in the inner tank floor.

Further, the step S3 includes:

The rotating storage tank bottom plate detection device uses different segmented annular receiving coils to receive the reflected guided wave signal, and comprehensively analyzes the corrosion information of the storage tank bottom plate to be detected.

The beneficial effect of adopting the above-mentioned further technical solution is: using different segmented circumferential receiving coils to receive the reflected guided wave signal can further improve the positioning accuracy of the corrosion defect on the bottom plate of the storage tank.

Advantages of additional aspects of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.

Description of drawings

Fig. 1 is a cross-sectional view of a detection device for a bottom plate of a storage tank provided by an embodiment of the present invention.

Fig. 2 is a schematic structural diagram of an omnidirectional electromagnetic ultrasonic guided wave transducer for magnetic flux leakage detection sensor provided by an embodiment of the present invention.

Fig. 3 is a cross-sectional view of the omnidirectional electromagnetic ultrasonic guided wave transducer provided by the embodiment of the present invention.

Fig. 4 is a cross-sectional view of the structure of the first outer ring magnet and the second outer ring magnet provided by the embodiment of the present invention.

Fig. 5 is a schematic structural diagram of a detection device for a bottom plate of a storage tank provided by an embodiment of the present invention.

Fig. 6 is a schematic flowchart of a detection method for a bottom plate of a storage tank provided by an embodiment of the present invention.

Description of reference numerals: 1. First outer ring magnet; 2. Second outer ring magnet; 3. Inner ring magnet; 4. Ring excitation coil; 5. Isolation layer; 6. Ring receiving coil; 7. Hall element; 8. Silicon steel sheet; 9. Epoxy resin intermediate layer.

Detailed ways

The principles and features of the present invention are described below in conjunction with the accompanying drawings, and the examples given are only used to explain the present invention, and are not intended to limit the scope of the present invention.

As shown in Figures 1 to 5, the embodiment of the present invention provides a detection device for the bottom plate of a storage tank, including: a first outer ring magnet 1, a second outer ring magnet 2, an inner ring magnet 3, a ring excitation coil 4, an isolation Layer 5, multi-segment annular receiving coil 6, Hall element 7, the second outer ring magnet 2 is sleeved on the outside of the inner ring magnet 3, the first outer ring magnet 1 is sleeved on the second outer ring magnet The outer side of the ring magnet 2, the annular excitation coil 4 is wound on the outer side of the second outer ring magnet 2 and the inner ring magnet 3, and the multi-section annular receiving coil 6 is along the periphery of the first outer ring magnet 1 Winding on the first outer ring magnet 1, the isolation layer 5 is installed between the first outer ring magnet 1 and the second outer ring magnet 2, and the Hall element 7 is installed on the In isolation layer 5.

The beneficial effect of adopting the technical solution of the present invention is that a wide range of storage tank floor corrosion detection can be realized without direct contact or ultrasonic coupling, the structure of the annular permanent magnet is rationally designed, and the annular excitation coil, annular receiving coil and Hall Components to realize the organic integration of magnetic flux leakage detection and electromagnetic ultrasonic guided wave detection technology. The single detection range is large, which is convenient for comprehensive and rapid inspection of the large-area storage tank bottom plate. It does not need to pre-treat the surface of the tested sample and apply couplant, and has low requirements on the surface of the tested structure, realizing a wide range of full-angle areas. Composite detection and positioning of corrosion defects in the interior solves the technical problem that the existing technology cannot realize the comprehensive detection of ultrasonic guided wave and magnetic flux leakage on the tested material, resulting in incomplete detection. Improve the detection efficiency of the bottom plate of the storage tank and reduce the consumption of manpower and material resources. The use of electromagnetic ultrasonic guided wave transducers can excite omnidirectional horizontal shear guided waves, which will generate echoes after interacting with corrosion defects. Through the collection of echo signals by the outer ring circumferential receiving coil, a certain range can be accurately located Corrosion defects in the inner tank floor.

Reasonably designing the structure of the annular permanent magnet, arranging the annular excitation coil, receiving coil (annular receiving coil) and Hall elements can realize the organic integration of magnetic flux leakage detection and electromagnetic ultrasonic guided wave detection technology. There is no need for coupling contact with the surface of the test piece (tank bottom plate), and the use of electromagnetic ultrasonic guided wave transducers can excite omnidirectional horizontal shear guided waves, which will generate echoes after interacting with corrosion defects, and pass through the circumferential direction of the outer ring. The collection of echo signals by the receiving coil (ring receiving coil) can accurately locate the corrosion defects of the bottom plate of the storage tank within a certain range. The second outer ring magnet and the inner ring magnet provide radially opposite bias static magnetic fields at the bottom of the storage tank (storage tank floor) to excite omnidirectionally propagating horizontal shear guided waves. There is no need to pre-treat and apply coupling agent to the surface of the tested sample (tank bottom plate), and it has low requirements on the surface of the tested structure (tank bottom plate), and realizes composite detection and positioning of corrosion defects in a wide range of full-angle areas.

In Fig. 1, the spiral arrow pointing to the left represents the direction of the excited guided wave signal, and the spiral arrow pointing to the right represents the direction of the reflected guided wave signal. The arrows in Figure 2 represent the transmission direction and track of the signal. The spiral arrows in Fig. 3 represent the directions of SH ₀ guided waves. The double-headed arrows in Figure 5 represent the location of the loop receiving coil.

As shown in FIGS. 1 to 5 , further, the first outer ring magnet 1 , the second outer ring magnet 2 and the inner ring magnet 3 are arranged coaxially.

The beneficial effect of adopting the above further technical solution is: the material used to magnetize the structure to be tested and generate a magnetic field signal inside the structure to be tested.

As shown in FIG. 1 to FIG. 5 , further, the annular excitation coil 4 is wound outside the combination formed by the second outer ring magnet 2 and the inner ring magnet 3 .

The beneficial effect of adopting the above-mentioned further technical solution is that: the second outer ring magnet and the inner ring magnet provide radially opposite bias static magnetic fields at the bottom of the storage tank to excite omnidirectionally propagating horizontal shear guided waves. That is, the second outer ring magnet, the inner ring magnet, and the annular excitation coil wound on the second outer ring magnet and the inner ring magnet assembly cooperate with each other to generate electromagnetic ultrasonic guided waves. The static bias magnetic field perpendicular to the tested object is provided by the second outer ring magnet and the inner ring magnet, and the annular excitation coil is connected with a high-frequency excitation current to generate radially distributed induced eddy currents on the upper surface of the bottom plate of the tested storage tank. The induced eddy currents Under the action of the static bias magnetic field, the high-frequency vibration of the particle on the surface of the plate is induced by the Lorentz force, and then the horizontal shear guided wave propagating in all directions is excited.

As shown in Figures 1 to 5, further, the isolation layer 5 includes: a pair of silicon steel sheets 8 and an epoxy resin intermediate layer 9, a pair of silicon steel sheets 8 corresponding to the first outer ring magnet 1 and the second outer ring magnet 2 are connected, the epoxy resin intermediate layer 9 is installed between a pair of the silicon steel 8, and the Hall element 7 is located at the bottom of the epoxy resin intermediate layer 9 .

The beneficial effect of adopting the above-mentioned further technical scheme is: an isolation layer is set between the first outer ring magnet and the second outer ring magnet, the lower part is a uniform magnetic field area, and a magnetic field measurement sensor such as a Hall element is arranged in the middle of the uniform magnetic field area. It is used to detect whether there is a magnetic field signal outside the structure to be tested, and the magnetic flux leakage detection of corrosion defects can be realized. The isolation layer is composed of silicon steel sheets on both sides and an epoxy resin intermediate layer. The silicon steel sheets surrounding the first outer ring magnet and the second outer ring magnet are used as high magnetic permeability materials to shield the magnetic field between them and prevent mutual Signal interference affects the accuracy of corrosion detection.

As shown in Figures 1 to 5, further, the N pole of the first outer ring magnet 1 is located above the S pole, the N pole of the second outer ring magnet 2 is located below the S pole, and the inner ring magnet 3 The N pole is above the S pole.

The beneficial effect of adopting the above-mentioned further technical solution is that a wide range of storage tank floor corrosion detection can be realized without direct contact or ultrasonic coupling, the structure of the ring permanent magnet is reasonably designed, and the ring excitation coil, the ring receiving coil and the Hall Components to realize the organic integration of magnetic flux leakage detection and electromagnetic ultrasonic guided wave detection technology. The single detection range is large, which is convenient for comprehensive and rapid inspection of the large-area storage tank bottom plate. It does not need to pre-treat the surface of the tested sample and apply couplant, and has low requirements on the surface of the tested structure, realizing a wide range of full-angle areas. Composite detection and positioning of corrosion defects in the interior solves the technical problem that the existing technology cannot realize the comprehensive detection of ultrasonic guided wave and magnetic flux leakage on the tested material, resulting in incomplete detection. Improve the detection efficiency of the bottom plate of the storage tank and reduce the consumption of manpower and material resources. The use of electromagnetic ultrasonic guided wave transducers can excite omnidirectional horizontal shear guided waves, which will generate echoes after interacting with corrosion defects. Through the collection of echo signals by the outer ring circumferential receiving coil, a certain range can be accurately located Corrosion defects in the inner tank floor.

As shown in FIG. 1 to FIG. 5 , further, the top and bottom ends of the first outer ring magnet 1 , the second outer ring magnet 2 and the inner ring magnet 3 are respectively located on the same plane.

The beneficial effect of adopting the above further technical solution is that it is convenient for installation and maintenance of the detection device for the bottom plate of the storage tank, it is convenient for storage and transportation of the detection device for the bottom plate of the storage tank, and the structure of the detection device for the bottom plate of the storage tank is compact.

As shown in FIGS. 1 to 5 , further, the first outer ring magnet 1 , the second outer ring magnet 2 and the inner ring magnet 3 are all ring structures.

The beneficial effect of adopting the above further technical solution is that it is convenient for installation and maintenance of the detection device for the bottom plate of the storage tank, it is convenient for storage and transportation of the detection device for the bottom plate of the storage tank, and the structure of the detection device for the bottom plate of the storage tank is compact.

1. Realize that the detection sensor device (tank bottom plate detection device) and the surface of the metal structure (storage tank bottom plate) have a certain distance, without direct contact or ultrasonic coupling, a wide range of storage tank bottom plate corrosion can be realized Detection, by rationally designing the structural distribution of permanent magnets (the first outer ring magnet, the second outer ring magnet and the inner ring magnet), the fusion of electromagnetic guided wave detection and magnetic flux leakage detection methods has been formed, which solves the problem that the existing technology cannot The material under test (tank bottom plate) is subjected to ultrasonic guided wave and magnetic flux leakage comprehensive testing, resulting in the technical problem of incomplete testing.

2. Reasonably design the structure of the ring-shaped permanent magnet (the first outer ring magnet, the second outer ring magnet and the inner ring magnet), and arrange the ring-shaped excitation coil, receiving coil (shaped receiving coil) and Hall element, which can realize magnetic flux leakage detection and Organic fusion of electromagnetic ultrasonic guided wave testing technology. There is no need for coupling contact with the surface of the test piece (tank bottom plate), and the use of electromagnetic ultrasonic guided wave transducers can excite omnidirectional horizontal shear guided waves, which will generate echoes after interacting with corrosion defects, and pass through the circumferential direction of the outer ring. The collection of echo signals by the receiving coil (ring receiving coil) can accurately locate the corrosion defects of the bottom plate of the storage tank within a certain range.

The magnetic flux leakage signal is a low-frequency signal (below 5kHz), and the frequency domain interval used by the electromagnetic ultrasonic guided wave detection is 5-300kHz. The signal characteristics of the two are different, but both require a magnetizer to magnetize the component (tank bottom plate) or The excitation and reception of signals are carried out through the synergy of dynamic and static magnetic fields. Therefore, the present invention realizes the organic integration of the electromagnetic ultrasonic guided wave technology and the magnetic flux leakage detection technology through the reasonable arrangement of the ring-shaped permanent magnets and the signal excitation and reception methods in different frequency domains. efficiency. In the detection process, the characteristics of fixed-point excitation and long-distance detection of electromagnetic ultrasonic guided wave are firstly used to quickly detect the bottom plate of large-area storage tanks, and initially locate the severely corroded parts, and then move the sensor (Hall element) to this area, and use The magnetic flux leakage method can accurately detect the position and size of the defect; in addition, the electromagnetic ultrasonic guided wave technology can perform long-distance coverage detection on positions that are difficult to reach with ordinary sensors.

A storage tank bottom plate detection device, which can be a non-contact storage tank bottom plate composite detection device, consists of a ring-shaped permanent magnet (a first outer ring magnet, a second outer ring magnet, and an inner ring magnet), a ring-shaped excitation coil 4, and an isolation layer 5 , N-segment annular receiving coils 6 and Hall elements 7 distributed in the circumferential direction, wherein the annular permanent magnets include a first outer ring magnet 1, a second outer ring magnet 2 and an inner ring magnet 3 coaxially socketed in sequence; It is used to magnetize the material of the structure under test (tank floor) and generate a magnetic field signal inside the structure under test (tank floor).

An annular excitation coil 4 is wound on the combination of the second outer ring magnet 2 and the inner ring magnet 3 .

Wherein, the second outer ring magnet 2 , the inner ring magnet 3 and the annular excitation coil 4 wound on the combination of the second outer ring magnet and the inner ring magnet cooperate with each other to generate electromagnetic ultrasonic guided waves.

Specifically, the second outer ring magnet 2 and the inner ring magnet 3 provide a static bias magnetic field perpendicular to the tested object (storage tank bottom plate), and the ring-shaped excitation coil is connected to a high-frequency excitation current and is placed on the surface of the tested storage tank bottom plate. Generate radially distributed induced eddy currents. Under the action of the static bias magnetic field, the induced eddy currents are subjected to the Lorentz force to cause high-frequency vibrations of the surface particles of the plate (tank bottom plate), and then stimulate the omnidirectional horizontal shear. guided wave.

The main factor affecting the coverage of the horizontal shear guided wave is the circumferential arrangement spacing of the annular excitation coil 4. If the circumferential arrangement spacing of the annular excitation coil 4 is very small, it can be guaranteed that the Lorentz force generated by the electromagnetic ultrasonic guided wave exciter is Uniform, so that the horizontal shear guided wave covering 360° can be emitted; the smaller the circumferential arrangement spacing of the annular excitation coil 4 is, the larger the coverage of the horizontal shear guided wave is.

Further, the first outer ring magnet 1 is wound with N segments of annular receiving coils 6 in the circumferential direction. By analyzing the propagation time of the echo signal and the direction of the receiving coils, corrosion defects on the bottom plate of the storage tank can be located. If the annular receiving coil 6 is segmented enough, the location of corrosion defects will be more accurate.

Specifically, an isolation layer 5 is set between the first outer ring magnet 1 and the second outer ring magnet 2, the lower part is a uniform magnetic field area, and a magnetic field measurement sensor is arranged in the middle of the uniform magnetic field area, such as a Hall element 7 , which is used to detect whether there is a magnetic field signal outside the structure to be tested, and can realize the magnetic flux leakage detection of corrosion defects.

Further, the isolation layer 5 is composed of silicon steel sheets 8 on both sides and an epoxy resin intermediate layer 9, wherein the silicon steel sheets surrounding the first outer ring magnet and the second outer ring magnet can shield the gap between the two as a high magnetic permeability material. The magnetic field between them can prevent mutual signal interference and affect the accuracy of corrosion detection.

In addition, the detection device for the bottom plate of the storage tank provided in the embodiment of the present invention may be a non-contact composite detection device for the bottom plate of the storage tank, and its principle for corrosion detection of the bottom plate of the storage tank is specifically:

The principle of magnetic flux leakage detection: When a magnetic field is applied to a ferromagnetic workpiece (such as the bottom plate of a storage tank) with a defect, because the magnetic permeability of the ferromagnetic material is different from that of the defect, the magnetic flux will be distorted at the defect, and a part of the magnetic flux will be It escapes from the surface of the workpiece (tank bottom plate), passes through the air and then returns to the S pole. This part is the so-called magnetic flux leakage. The strength of the magnetic field leakage is proportional to the size and depth of the defect. It is detected by the Hall element. The size of this part of the magnetic flux can be calculated to know the size and depth of the defect.

The principle of electromagnetic guided wave detection: the annular excitation coil is arranged in the static bias magnetic field distributed periodically in space. The surface of the bottom plate) is parallel to the surface. Under the Lorentz force, the vibration direction of the particle is perpendicular to the direction of the eddy current and parallel to the surface of the test piece (tank bottom plate). The vibration propagates in the horizontal direction and excites the horizontal shear guided wave.

其中，T为导波从激励到接收到信号的时间间隔，C_g为SH₀导波的群速度，L即为腐蚀缺陷至接收线圈(环形接收线圈)之间的距离。Signal processing process: When using electromagnetic ultrasonic guided waves to detect corrosion defects on the bottom plate of storage tanks, it is necessary to analyze and process the received reflected signals. 360° all-round bottom plate (tank bottom plate) corrosion defect, the segmented coil (ring receiving coil) that receives the reflected signal is oriented to represent the direction of the corrosion defect; half of the time from excitation to signal reception is the same as the horizontal shear guided wave The product of the group velocity represents the distance between the corrosion defect and the receiving coil (annular receiving coil), as shown in the formula:

Among them, T is the time interval from excitation to signal reception of the guided wave, C _g is the group velocity of the SH ₀ guided wave, and L is the distance from the corrosion defect to the receiving coil (ring receiving coil).

As shown in Figure 6, in addition, the present invention also provides a storage tank bottom plate detection method, based on a storage tank bottom plate detection device described in any one of the above, a storage tank bottom plate detection method includes:

S1. The detection device for the bottom plate of the storage tank is close to the bottom plate of the storage tank to be detected;

S2. The annular excitation coil excites the horizontal shear guided wave propagating along the 360° direction, and performs corrosion detection on the bottom plate of the storage tank;

S3. The annular receiving coil analyzes the reflected guided wave signal, and locates the corrosion defect within the detection range;

S4. The Hall element analyzes the magnetic flux leakage signal of the bottom plate of the storage tank to be detected, and obtains the corrosion information of the bottom plate of the storage tank to be detected under the detection device for the bottom plate of the storage tank.

The beneficial effect of adopting the technical solution of the present invention is that a wide range of storage tank floor corrosion detection can be realized without direct contact or ultrasonic coupling, the structure of the annular permanent magnet is rationally designed, and the annular excitation coil, annular receiving coil and Hall Components to realize the organic integration of magnetic flux leakage detection and electromagnetic ultrasonic guided wave detection technology. The single detection range is large, which is convenient for comprehensive and rapid inspection of the large-area storage tank bottom plate. It does not need to pre-treat the surface of the tested sample and apply couplant, and has low requirements on the surface of the tested structure, realizing a wide range of full-angle areas. Composite detection and positioning of corrosion defects in the interior solves the technical problem that the existing technology cannot realize the comprehensive detection of ultrasonic guided wave and magnetic flux leakage on the tested material, resulting in incomplete detection. Improve the detection efficiency of the bottom plate of the storage tank and reduce the consumption of manpower and material resources. The use of electromagnetic ultrasonic guided wave transducers can excite omnidirectional horizontal shear guided waves, which will generate echoes after interacting with corrosion defects. Through the collection of echo signals by the outer ring circumferential receiving coil, a certain range can be accurately located Corrosion defects in the inner tank floor.

Further, the step S3 includes:

The rotating storage tank bottom plate detection device uses different segmented annular receiving coils to receive the reflected guided wave signal, and comprehensively analyzes the corrosion information of the storage tank bottom plate to be detected.

The beneficial effect of adopting the above-mentioned further technical solution is: using different segmented circumferential receiving coils to receive the reflected guided wave signal can further improve the positioning accuracy of the corrosion defect on the bottom plate of the storage tank.

An embodiment of the present invention provides a storage tank bottom plate detection method, which can be a working method of a non-contact storage tank bottom plate composite detection device, including:

Step 1: Put the composite detection device (tank bottom plate detection device) close to the storage tank bottom plate, and excite the horizontal shear guided wave propagating in the 360° direction through the ring excitation coil, and perform corrosion detection on the storage tank bottom plate;

Step 2: Analyze the reflected guided wave signal and locate the corrosion defect within the detection range;

Step 3: Analyze the magnetic flux leakage signal of the storage tank bottom plate through the Hall element, and obtain the corrosion information of the storage tank bottom plate under the composite detection device (storage tank bottom plate detection device);

Step 4: Rotate the composite detection device (tank bottom plate detection device), use different segmented circumferential receiving coils (ring receiving coils) to receive the reflected guided wave signal, and comprehensively analyze the corrosion information of the storage tank bottom plate.

Using different segmented circumferential receiving coils (annular receiving coils) to receive the reflected guided wave signals can further improve the positioning accuracy of corrosion defects on the bottom plate of the storage tank.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present invention, rather than limiting them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: It is still possible to modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the technical solutions of the various embodiments of the present invention. scope.

Claims (9)

1. A storage tank floor detection device, characterized in that it comprises: a first outer ring magnet, a second outer ring magnet, an inner ring magnet, an annular excitation coil, an isolation layer, a multi-section annular receiving coil, and a Hall element. The second outer ring magnet is sleeved on the outside of the inner ring magnet, the first outer ring magnet is sleeved on the outside of the second outer ring magnet, and the annular excitation coil is wound on the second outer ring magnet and the outer side of the inner ring magnet, the multi-segment annular receiving coil is wound on the first outer ring magnet along the circumferential direction of the first outer ring magnet, and the isolation layer is installed on the first outer ring magnet Between the second outer ring magnet, the Hall element is installed in the isolation layer. 2 . The detection device for the bottom plate of a storage tank according to claim 1 , wherein the first outer ring magnet, the second outer ring magnet and the inner ring magnet are arranged coaxially. 3 . 3 . The detection device for the bottom plate of a storage tank according to claim 1 , wherein the annular excitation coil is wound outside the combination formed by the second outer ring magnet and the inner ring magnet. 4 . 4. The detection device for the bottom plate of a storage tank according to claim 1, wherein the isolation layer comprises: a pair of silicon steel sheets and an epoxy resin intermediate layer, and the pair of silicon steel sheets correspond to the said silicon steel sheets one by one. The first outer ring magnet is connected to the second outer ring magnet, the epoxy resin intermediate layer is installed between a pair of silicon steels, and the Hall element is located at the bottom of the epoxy resin intermediate layer. 5. The detection device for the bottom plate of a storage tank according to claim 1, wherein the N pole of the first outer ring magnet is located above the S pole, and the N pole of the second outer ring magnet is located below the S pole , the N pole of the inner ring magnet is located above the S pole. 6. The detection device for the bottom plate of a storage tank according to claim 1, wherein the top and bottom ends of the first outer ring magnet, the second outer ring magnet, and the inner ring magnet are respectively located at the same on flat surface. 7 . The detection device for the bottom plate of a storage tank according to claim 1 , wherein the first outer ring magnet, the second outer ring magnet and the inner ring magnet are all ring structures. 7 . 8. A storage tank bottom plate detection method, characterized in that, based on the storage tank bottom plate detection device described in any one of claims 1 to 7, a storage tank bottom plate detection method comprises: S1. The detection device for the bottom plate of the storage tank is close to the bottom plate of the storage tank to be detected; S2. The annular excitation coil excites the horizontal shear guided wave propagating along the 360° direction, and performs corrosion detection on the bottom plate of the storage tank; S3. The annular receiving coil analyzes the reflected guided wave signal, and locates the corrosion defect within the detection range; S4. The Hall element analyzes the magnetic flux leakage signal of the bottom plate of the storage tank to be detected, and obtains the corrosion information of the bottom plate of the storage tank to be detected under the detection device for the bottom plate of the storage tank. 9. A storage tank floor detection method according to claim 8, characterized in that the step S3 comprises: The rotating storage tank bottom plate detection device uses different segmented annular receiving coils to receive the reflected guided wave signal, and comprehensively analyzes the corrosion information of the storage tank bottom plate to be detected.

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