Pipeline defect quantitative detection method and system based on annular ultrasonic phased array

Abstract

The invention belongs to the technical field of ultrasonic nondestructive testing, and relates to a pipeline defect quantitative detection method and system based on an annular ultrasonic phased array, and the method comprises the following steps: carrying out sound beam scanning on the inner wall of a pipeline based on the annular ultrasonic phased array; sound beams are controlled to be propagated in the pipeline at different incident angles, and the incident sound waves at different angles interact with the defect to generate defect echo signal information; and detecting the defect depth and the circumferential and axial defect sizes according to the defect echo signal information. The system comprises an acoustic beam scanning module, a defect echo signal information generation module and a detection module. According to the method and the system, the pipeline can be subjected to defect detection and long-time monitoring through single equipment, meanwhile, the potential defects of the pipeline can be quantitatively detected without replacing the equipment, and the operation is simple.

Description

Technical Field

[0001] The invention belongs to the technical field of ultrasonic nondestructive testing, and in particular relates to a pipeline defect quantitative detection method and system based on an annular ultrasonic phased array. Background Art

[0002] Research on pipeline nondestructive testing technology has been carried out for many years. However, due to the complexity of pipeline structure and its service environment, previous detection methods have their limitations in engineering applications, mainly manifested in: the use of point-by-point scanning and sampling detection methods is inefficient and prone to missed detection; the insulation layer and anti-corrosion layer covering the outer wall of the pipeline need to be peeled off multiple times for quantitative testing, thereby destroying the integrity of the pipeline structure and increasing the cost of testing and maintenance; for pipelines in special service environments such as buried underground, they are blindly excavated and scrapped due to unknown pipeline conditions, and the detection and maintenance lack scientificity. At the same time, it is difficult for existing detection methods to perform quantitative detection of erosion and corrosion area through a single device.

[0003] Modern ultrasonic phased array detection technology uses an electronic system to control the excitation sequence of the array elements in the array transducer, accurately controls the phase of the transmission and reception signals of each element of the transducer, causes interference and superposition of ultrasonic waves, controls the synthetic sound beam to achieve focusing and deflection of the synthetic sound beam, forms a scan line, and performs detection on multiple scan lines within the scanning range, ultimately obtaining an intuitive and friendly defect detection image; at the same time, by improving the guided wave detection software to reduce the training time of operators, reduce the difficulty of using the guided wave system, and improve the detection accuracy of the equipment.

[0004] Based on ultrasonic phased array detection technology, the present invention aims to propose a pipeline defect quantitative detection method, which solves the technical problem that the existing pipeline non-destructive detection method can only determine the defect location but cannot identify and quantitatively evaluate the defects. Summary of the invention

[0005] In view of the above problems, the present invention proposes a pipeline defect quantitative detection method and system based on annular ultrasonic phased array, which qualitatively analyzes the axial and circumferential dimensions of defects in the pipeline and determines the axial and circumferential positions of the damage in the pipeline.

[0006] The technical solution adopted by the present invention is as follows: a method for quantitative detection of pipeline defects based on an annular ultrasonic phased array, characterized in that the method comprises the following steps: scanning the inner wall of the pipeline with an acoustic beam based on the annular ultrasonic phased array; controlling the acoustic beam to propagate in the pipeline at different incident angles, and the incident sound waves at different angles interact with the defects to generate defect echo signal information; and detecting the defect depth, circumferential and axial defect sizes according to the defect echo signal information.

[0007] Furthermore, the acoustic beam scanning of the inner wall of the pipeline based on the annular ultrasonic phased array includes: all array elements of the annular ultrasonic phased array are combined into a closed circular ring, and ultrasonic waves are radiated to the outside of the circular ring. When the center line of the annular ultrasonic phased array coincides with the axial center line of the pipeline, the main acoustic beam line of each array element of the ultrasonic phased array is vertically incident on the inner wall of the measured pipeline. When the main acoustic beam line propagates circumferentially and axially along the inner wall of the measured pipeline, reflected waves and transmitted waves are generated when passing through defects, thereby completing the circumferential and axial scanning of the inner wall of the pipeline.

[0008] Furthermore, before using the annular ultrasonic phased array to scan the inner wall of the pipeline in the circumferential and axial directions, the number n of working array elements in each group is first determined. When working, starting from the array element at the start point of the scanning of area A, array elements No. 1 to No. n in a clockwise direction simultaneously receive the excitation signal and work; if n is an odd number, the receiving array element is No. (n+1) / 2; if n is an even number, the receiving array element is No. n / 2;

[0009] Next, array elements 2 to n+1 work simultaneously, and array elements 3 to n+2 work simultaneously, and this scanning mode is followed in sequence until all array elements in areas B, C, and D work in sequence and receive signals.

[0010] Furthermore, at the same time, the number n of working elements of the annular ultrasonic phased array is set to 1-16, and the pipeline is detected in an arc-shaped clockwise rotating scanning manner at different times. After scanning for one circle, the information of the entire circumferential direction of the pipeline is detected.

[0011] Furthermore, the annular ultrasonic phased array includes array elements in two states, namely working array elements and non-working array elements; the number of working array elements in each group is set to n=5, and the array elements in each group are detected in turn according to the same delay rule. Taking the number of 9 array elements as an example, the working array elements in the first group are 1-5, and the non-working array elements are 6-9; the working array elements in the second group are 2-6, and the non-working array elements are 1 and 7-9; the working array elements in the third group are 3-7, and the non-working array elements are 1, 2, 8 and 9; the working array elements in the fourth group are 4-8, and the non-working array elements are 1-3 and 9. This rule is followed until the last group. The array element in each group that receives the synthetic echo signal and is displayed on the upper computer is the middle array element, and the circumferential detection of the pipeline is completed in a clockwise direction.

[0012] Furthermore, the sound beam is controlled to propagate in the pipeline at different incident angles, and the incident sound waves at different angles interact with the defects to generate defect echo signal information, including: controlling the delay of each array element, changing the incident angle of the transmitted wave to cause the sound beam to shift, and obtaining the defect echo signal information through the incident sound waves at different angles. The defect echo signal information includes the amplitude of the incident sound wave at different angles, the echo shape and the receiving time.

[0013] Further, detecting the defect depth according to the defect echo signal information includes:

[0014] The relationship between the defect depth d and the time domain damage factor D1 is: D1 = 0.01 + 0.1*d - 0.01*d 2 -0.001*d 3 ;

[0015] The expression of the time domain damage factor D1 is: Among them, V h (t) is the normalized response signal of the echo signal under high amplitude excitation, V l (t) is the normalized response signal of the echo signal under low amplitude excitation, h is the high voltage excitation amplitude, and l is the low voltage excitation amplitude.

[0016] Further, detecting the axial defect size according to the defect echo signal information includes: extracting the first peak and arrival time of the reflected wave in front and behind the defect respectively, and obtaining the axial defect size L as: L = c t *(t2-t1) / 2, where t1 and t2 are the first peak and arrival time of the reflected wave in front of the defect and behind the defect respectively, c t is the guided wave velocity; the relationship between the axial defect size L and the time domain damage factor D1 is: D1=0.01+0.1*L-0.01*L 2 -0.001*L 3 .

[0017] Further, detecting the circumferential defect size according to the defect echo signal information includes: extracting the arrival time of the annular ultrasonic phased array transducer echo and the arrival time of the adjacent transducer echo respectively, and obtaining the circumferential defect size T as follows: T=c t *(t4-t3) / 2; where t3 and t4 are the arrival time of the echo of the annular ultrasonic phased array transducer and the arrival time of the echo of the adjacent transducer respectively; c t is the guided wave velocity; the relationship between the circumferential defect size T and the time domain damage factor D1 is: D1=0.01+0.1*T-0.01*T 2 -0.001*T 3 .

[0018] In addition, the present invention also relates to a pipeline defect quantitative detection system based on an annular ultrasonic phased array, characterized in that the system includes a sound beam scanning module, a defect echo signal information generating module and a detection module; the sound beam scanning module is used to perform sound beam scanning on the inner wall based on the annular ultrasonic phased array; the defect echo signal information generating module is used to control the sound beam to propagate in the pipeline at different incident angles, and the incident sound waves at different angles interact with the defects to generate defect echo signal information; the detection module is used to detect the defect depth, circumferential and axial defect sizes according to the defect echo signal information.

[0019] The present invention proposes a pipeline defect quantitative detection method and system based on annular ultrasonic phased array. Through a single device, not only can the pipeline be inspected for defects and monitored for a long time, but also the potential defects of the pipeline can be quantitatively detected without changing the equipment, and the operation is simple. By installing a transducer array at one place on the pipeline, the global detection of the pipeline within a range of tens of meters can be achieved, and the efficiency is high. Long-distance detection of the pipeline can be achieved by only stripping off the coating layer of about 100 meters at the installation position of the transducer array, and the cost is low.

[0020] Other features and advantages of the present invention will be described in the following description, and part of them will become obvious from the description, or be understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained through the description and the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0022] Figure 1 The present invention is a flow chart of a pipeline defect quantitative detection method based on annular ultrasonic phased array;

[0023] Figure 2 This is a simplified diagram of the scanning method of the annular ultrasonic phased array;

[0024] Figure 3 Schematic diagram of L(0,1) longitudinal modal excitation;

[0025] Figure 4a Schematic diagram of circular linear scanning excitation. Figure 4b It is a schematic diagram of circular linear scanning propagation;

[0026] Figure 5 It is a schematic diagram of an annular ultrasonic phased array transducer array;

[0027] Figure 6 Schematic diagram of a pipeline defect quantitative detection system based on a circular ultrasonic phased array. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] A pipeline defect quantitative detection method based on annular ultrasonic phased array, such as Figure 1 As shown, the method includes the following steps: scanning the inner wall of the pipeline with an acoustic beam based on a circular ultrasonic phased array; controlling the acoustic beam to propagate in the pipeline at different incident angles, and the incident sound waves at different angles interact with the defects to generate defect echo signal information; and detecting the defect depth, circumferential defect size and axial defect size according to the defect echo signal information.

[0030] When the annular ultrasonic phased array detects inside the pipeline, it has its own specific scanning and detection methods. The simplified scanning method of the annular ultrasonic phased array is as follows: Figure 2 As shown, Figure 2 There are two states of array elements, one is the working array element and the other is the non-working array element. The so-called working array element refers to the array element that is in the working state for a certain period of time. It will receive the pulse signal from the driving circuit and the delay law is applied. These array elements will participate in the detection of a certain area; the so-called non-working array element refers to the array element other than the working array element in a certain period of time. These non-working array elements will not receive the pulse signal during this period of time, so they will not participate in the detection. It is controlled by controlling the transmission delay of different array elements. The delay accuracy of the transmitting end will also affect the accuracy of the sound beam scanning angle. The higher the accuracy of the transmission delay, the higher the accuracy of the deflection angle of the transmitting beam. The annular ultrasonic phased array probe used in the embodiment of the present invention has an array element spacing of 0.4mm and a transmission delay accuracy of 2.5ns; when the scanning angle is -30°~30°, the angle deflection accuracy is close to 1°. By changing the transmission angle, the feedback of the transmission waves in different directions is received, so as to quantitatively analyze the potential defects.

[0031] The T(0,1) mode is used to transmit the excitation signal circumferentially. The number of working array elements in each group is set to n=5. Each group of array elements is detected in turn according to the same delay rule. Each group of array elements forms a wavefront for detecting different areas. Taking 9 array elements as an example, the working array elements of the first group are 1-5, and the non-working array elements are 6-9; the working array elements of the second group are 2-6, and the non-working array elements are 1 and 7-9; the working array elements of the third group are 3-7, and the non-working array elements are 1, 2, 8 and 9; the working array elements of the fourth group are 4-8, and the non-working array elements are 1-3 and 9. This rule is followed until the last group. The array element in each group that receives the synthetic echo signal and displays it on the host computer is the middle array element. In terms of effect, the detection of one circle of the pipeline is completed in a clockwise direction.

[0032] Before using the annular ultrasonic phased array for detection, the number of working array elements in each group, n, should be determined first. When working, start from the scanning starting array element in area A, and receive the excitation signal and work in clockwise direction from 1 to n array elements at the same time. If n is an odd number, the receiving array element is (n+1) / 2, and if n is an even number, the receiving array element is n / 2. Next, array elements 2 to n+1 work at the same time, and array elements 3 to n+2 work at the same time, and this scanning mode is followed in sequence until all array elements in areas B, C, and D work and receive signals in turn. The number of array elements working in the annular ultrasonic phased array at the same time can be controlled between 1 and 16 (i.e., 1≤n≤16), and the pipeline is detected in an arc-shaped clockwise rotation scanning manner at different times. After scanning for one circle, the information of the entire circumferential direction of the pipeline can be detected, achieving the purpose of full coverage detection of the circumference of the pipeline.

[0033] Using L(0,1) longitudinal modal excitation, such as Figure 3 As shown in the figure, each particle of the pipeline to be tested is axially stretched and contracted, and there is no lateral movement of the axis, which can effectively eliminate the modal conversion phenomenon of the sound wave during propagation. If all 16 excitations of each group are turned on, the pipeline will be scanned linearly in an annular manner, and the entire pipeline will be inspected for defects over a long distance. The excitation and propagation schematic diagrams are shown in the figure below. Figure 4a and Figure 4b During the scanning process, the transducer can be moved forward in the axial direction at a certain speed, and the entire pipeline can be inspected in all directions.

[0034] Annular ultrasonic phased array transducer array (such as Figure 5(As shown in the figure) is different from the ordinary annular array. Its array elements form a closed annular structure. Each array element radiates ultrasonic waves into the space outside the annular ring, and its propagation direction is radially outward along the annular ring. Therefore, an annular ultrasonic phased array can detect the area outside the annular ring without changing its position. This array arrangement mode is more suitable for internal detection of pipelines. In the annular ultrasonic phased array, all array element sizes and array element spacing are the same, and the array is divided into 4 working areas (such as Figure 5 As shown in the figure, they are A, B, C, and D areas respectively. The number of array elements in each area is evenly distributed. The starting array element in area A is array element 1, and the ending array element in area D is array element M. Then the array elements in areas A, B, C, and D are numbered in sequence in a clockwise direction, from 1 to M in total.

[0035] The array elements of the annular ultrasonic phased array are rectangular piezoelectric. This shape of array elements is relatively easy to manufacture and has low cost. The array element material is a piezoelectric composite material with stronger performance. All array elements are combined into a closed circular ring to radiate ultrasonic waves to the outside of the circular ring. When the center line of the phased array coincides with the axial center line of the pipeline, each array element of the ultrasonic phased array can be directly facing the inner wall of the pipeline under test. Compared with the one-dimensional linear ultrasonic phased array, the center line of the main sound beam of each array element can be vertically incident on the pipe wall, achieving a good match with the inner wall of the pipeline. The annular ultrasonic phased array is used for in-pipeline detection, and the sound beam is scanned in the circumferential direction of the pipeline. At the same time, the sound beam focusing can be controlled by the delay law, and each focus is closely arranged in a circle, thereby completing full coverage detection of the circumferential direction of the pipeline.

[0036] When conducting in-pipe inspection, the annular ultrasonic phased array transducer needs to enter the inside of the pipeline to inspect the pipeline, so its size cannot exceed the inner diameter of the pipeline. Since ultrasonic detection has a certain detection blind area, the annular ultrasonic phased array transducer cannot be close to the measured area, so the size of the annular ultrasonic phased array cannot be too large. And considering that the detection device can detect pipelines of various diameters, an annular ultrasonic phased array transducer of appropriate size is required. However, due to the constraints of the existing technology during hardware production and the limitation of its production cost, the size of the annular ultrasonic phased array circular transducer is finally selected in the embodiment of the present invention as: diameter × height = 20mm × 31mm. The more the number of annular ultrasonic phased array elements, the longer the focusing distance can be achieved, and the more concentrated the energy in the focusing area, the narrower the main lobe of the ultrasonic field, the higher the lateral resolution, and the lower the side lobe amplitude; but as the number of elements increases, the size of the annular ultrasonic phased array transducer will increase, and its cost will gradually increase, so an appropriate number of elements is required to ensure the detection effect. In the embodiment of the present invention, the number of elements is finally selected as 16. In addition, the frequency can affect the sound field of the ultrasonic phased array and has a certain impact on the detection accuracy; a high frequency can improve the detection resolution, but its attenuation in the medium is greater, so the selected frequency meets the best detection accuracy. In the embodiment of the present invention, a frequency of 50kHz is finally selected.

[0037] In addition, the array element spacing and array element width are very important parameters in the ultrasonic phased array transducer, which will affect the directivity of the sound field and the formation of grating lobes. When the array element spacing is reduced to the point where no grating lobes are generated, the array element width is independent of the main lobe and the position of the grating lobes, and is also independent of the width of the main lobe. However, the array element width will affect the amplitude of the sound pressure in the deflection direction of the array. The larger the array element width, the higher the deflection sound pressure in the array direction. When the array element spacing is large, the directivity of the sound field can be improved, while an excessively large array element spacing will form grating lobes in space that are prone to cause pseudo-defects. Therefore, on the basis of avoiding the generation of grating lobes as much as possible and ensuring that the main lobe width is as narrow as possible, the lateral resolution and larger scanning angle of the array probe are improved at the same time, and the largest array element is selected to enhance the amplitude of the sound pressure in the deflection direction of the array, thereby improving the signal-to-noise ratio of the detection.

[0038] In the embodiment of the present invention, when the transducer diameter is selected to be 20 mm and the number of array elements in each group is 16, the array element spacing is selected to be 50 mm.

[0039] When there is a defect in the pipeline, the sound beam deflection control based on the annular ultrasonic phased array makes the sound beam propagate in the pipeline at different incident angles. When there is a defect in the pipeline, the incident sound waves at different angles interact with the defect to generate defect echo signal information. Control the delay of each array element, change the incident angle of the transmitted wave to cause the sound beam to deviate, and obtain the defect echo signal information through the incident sound waves at different angles. The defect echo signal information includes the amplitude of the incident sound wave at different angles, the echo shape and the receiving time. As the defect size increases, the time domain damage factor D1 of the transmission or reflection signal caused by the defect also increases. With the help of the peak and variance in the random process, the transmission or reflection signal is analyzed, and fitted with the bottom wave amplitude under the variable pressure state, respectively, to find the statistical parameters with the greatest relationship with the defect size, and then indirectly perform quantitative analysis on the axial and circumferential dimensions of the defects in the pipeline.

[0040] The time domain damage factor D1 is obtained using the ultrasonic time domain energy attenuation method. The principle of the ultrasonic time domain energy attenuation method is to determine the received amplitude. Defects will reflect or scatter ultrasonic waves, causing the amplitude of ultrasonic waves to decrease during propagation. The overall health status of the pipeline is usually quantitatively evaluated by measuring the amplitude attenuation of the transmitted wave (ultrasonic transmission method) or the defect reflection echo (ultrasonic reflection method).

[0041] The expression of the time domain damage factor D1 obtained by testing with high amplitude voltage and low amplitude voltage is as follows:

[0042] The expression of the time domain damage factor D1 is: Among them, V h (t) is the normalized response signal of the echo signal under high amplitude excitation, V l (t) is the normalized response signal of the echo signal under low amplitude excitation, h is the high voltage excitation amplitude, and l is the low voltage excitation amplitude.

[0043] The relationship between the time domain damage factor D1 and the defect depth d is:

[0044] D1=0.01+0.1*d-0.01*d 2 -0.001*d 3 According to this relationship, the data shown in Table 1 can be obtained. The damage factor can be used to determine the size of the defect depth, thereby making a quantitative judgment on the defect level.

[0045] Table 1 Data related to defect depth d, time domain damage factor D1 and defect level

[0046] Defect depth d(mm) <![CDATA[Time domain damage factor D1]]> Defect level 0-20％d 0-0.061 slight 20%d-40%d 0.061-0.106 generally 40%d-60%d 0.106-0.152 medium 60%d-80%d 0.152-0.179 More serious 80% dd 0.179-0.207 serious

[0047] According to the defect echo signal information, by extracting the first peak and arrival time of the reflected wave in front and behind the defect respectively, the axial defect size L is obtained as: L = c t *(t2-t1) / 2, where t1 and t2 are the first peak and arrival time of the reflected wave in front of the defect and behind the defect respectively, c t is the guided wave velocity; the relationship between the axial defect size L and the time domain damage factor D1 is: D1=0.01+0.1*L-0.01*L 2 -0.001*L 3 .

[0048] When the defect depth is determined, for example, 50% defect depth d, according to the expression defined by the axial defect size L and the damage factor D1, Table 2 can also be obtained to determine the defect level, thereby determining the pipeline defect level corresponding to different axial defect sizes.

[0049] Table 2 Data on axial defect size, time domain damage factor D1 and defect grade

[0050]

[0051]

[0052] The circumferential defect size T is analyzed by the time variation of the reflected wave. By extracting the arrival time of the annular ultrasonic phased array transducer echo and the arrival time of the adjacent transducer echo, the circumferential defect size T is obtained as: T = c t *(t4-t3) / 2; where t3 and t4 are the arrival time of the echo of the annular ultrasonic phased array transducer and the arrival time of the echo of the adjacent transducer respectively; c t is the guided wave velocity; the relationship between the circumferential defect size T and the time domain damage factor D1 is: D1=0.01+0.1*T-0.01*T 2 -0.001*T 3 .

[0053] Taking the defect depth of 50%d as an example, the data shown in Table 3 are obtained. From the data shown in Table 3, it can be judged that the range of the time domain damage factor D1 corresponding to different circumferential defect sizes T is different, thereby judging the pipeline defect level corresponding to different circumferential defect sizes T.

[0054] Table 3 Data on circumferential defect size, time domain damage factor D1 and defect level

[0055] Circumferential defect size T(mm) <![CDATA[Time domain damage factor D1]]> Defect level 0-20 0-0.012 slight 20-40 0.012-0.014 generally 40-60 0.014-0.016 medium 60-80 0.016-0.018 More serious 80-100 0.018-0.020 serious

[0056] In addition, the present invention also relates to a pipeline defect quantitative detection system based on annular ultrasonic phased array, such as Figure 6As shown, the system includes an acoustic beam scanning module 11, a defect echo signal information generating module 12 and a detection module 13. The acoustic beam scanning module 11 is used to perform acoustic beam scanning on the inner wall based on an annular ultrasonic phased array; the defect echo signal information generating module 12 is used to control the acoustic beam to propagate in the pipeline at different incident angles, and the incident sound waves at different angles interact with the defect to generate defect echo signal information; the detection module 13 is used to detect the defect depth, circumferential and axial defect sizes according to the defect echo signal information.

[0057] Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent substitutions for some of the technical features therein; and these modifications or substitutions do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A pipeline defect quantitative detection method based on annular ultrasonic phased array, characterized in that: The method comprises the following steps: The inner wall of the pipeline is scanned by acoustic beam based on the annular ultrasonic phased array; The sound beam is controlled to propagate in the pipeline at different incident angles. The incident sound waves at different angles interact with the defects to generate defect echo signal information; The defect depth, circumferential and axial defect sizes are detected based on the defect echo signal information.

2. The method according to claim 1, characterized in that The sound beam scanning of the inner wall of the pipeline based on the annular ultrasonic phased array includes: All the array elements of the annular ultrasonic phased array are combined into a closed circle, radiating ultrasonic waves to the outside of the circle. When the center line of the annular ultrasonic phased array coincides with the axial center line of the pipeline, the main sound beam line of each array element of the ultrasonic phased array is vertically incident on the inner wall of the measured pipeline. When the main sound beam line propagates circumferentially and axially along the inner wall of the measured pipeline, reflected waves and transmitted waves will be generated when passing through the defects, completing the circumferential and axial scanning of the inner wall of the pipeline.

3. The method according to claim 2, characterized in that Before using the annular ultrasonic phased array to scan the inner wall of the pipeline in the circumferential and axial directions, first determine the number n of each group of working array elements. When working, starting from the scanning starting point array element in area A, array elements 1 to n in a clockwise direction simultaneously receive the excitation signal and work; if n is an odd number, the receiving array element is (n+1) / 2; if n is an even number, the receiving array element is n / 2; Next, array elements 2 to n+1 work simultaneously, and array elements 3 to n+2 work simultaneously, and this scanning mode is followed in sequence until all array elements in areas B, C, and D work in sequence and receive signals.

4. The method according to claim 3, characterized in that At the same time, the number n of working elements of the annular ultrasonic phased array is set to 1 to 16, and the pipeline is inspected in an arc-shaped clockwise rotating scanning manner at different times. After scanning for one circle, the information of the entire circumferential direction of the pipeline is detected.

5. The method according to any one of claims 2 to 4, characterized in that: The annular ultrasonic phased array includes array elements in two states, namely working array elements and non-working array elements; the number of working array elements in each group is set to n=5, and the array elements in each group are detected in turn according to the same delay rule. Taking 9 array elements as an example, the working array elements in the first group are 1-5, and the non-working array elements are 6-9; the working array elements in the second group are 2-6, and the non-working array elements are 1 and 7-9; the working array elements in the third group are 3-7, and the non-working array elements are 1, 2, 8 and 9; the working array elements in the fourth group are 4-8, and the non-working array elements are 1-3 and 9. This rule is followed until the last group. The array element in each group that receives the synthetic echo signal and is displayed on the upper computer is the middle array element, and the circumferential detection of the pipeline is completed in a clockwise manner.

6. The method according to claim 5, characterized in that The sound beam is controlled to propagate in the pipeline at different incident angles. The incident sound waves at different angles interact with the defects to generate defect echo signal information, including: controlling the delay of each array element, changing the incident angle of the transmitted wave to cause the sound beam to shift, and obtaining the defect echo signal information through the incident sound waves at different angles. The defect echo signal information includes the amplitude of the incident sound wave at different angles, the echo shape and the receiving time.

7. The method according to claim 6, characterized in that Detecting defect depth based on defect echo signal information includes: The relationship between the defect depth d and the time domain damage factor D1 is: D1 = 0.01 + 0.1*d - 0.01*d 2 -0.001*d 3 ; The expression of the time domain damage factor D1 is: Among them, V h (t) is the normalized response signal of the echo signal under high amplitude excitation, V l (t) is the normalized response signal of the echo signal under low amplitude excitation, h is the high voltage excitation amplitude, and l is the low voltage excitation amplitude.

8. The method according to claim 7, characterized in that According to the defect echo signal information, by extracting the first peak and arrival time of the reflected wave in front and behind the defect respectively, the axial defect size L is obtained as: L = c t *(t2-t1) / 2, where t1 and t2 are the first peak and arrival time of the reflected wave in front of the defect and behind the defect respectively, c t is the guided wave velocity; the relationship between the axial defect size L and the time domain damage factor D1 is: D1=0.01+0.1*L-0.01*L 2 -0.001*L 3 .

9. The method according to claim 7, characterized in that: Detection of circumferential defect size based on defect echo signal information includes: By extracting the arrival time of the annular ultrasonic phased array transducer echo and the arrival time of the adjacent transducer echo, the circumferential defect size T is obtained as: T = c t *(t4-t3) / 2; where t3 and t4 are the arrival time of the echo of the annular ultrasonic phased array transducer and the arrival time of the echo of the adjacent transducer respectively; c t is the guided wave velocity; the relationship between the circumferential defect size T and the time domain damage factor D1 is: D1=0.01+0.1*T-0.01*T 2 -0.001*T 3 .

10. A pipeline defect quantitative detection system based on annular ultrasonic phased array, characterized in that: The system includes an acoustic beam scanning module, a defect echo signal information generating module and a detection module. The acoustic beam scanning module is used to perform acoustic beam scanning on the inner wall based on the annular ultrasonic phased array; The defect echo signal information generating module is used to control the sound beam to propagate in the pipeline at different incident angles, and the incident sound waves at different angles interact with the defect to generate defect echo signal information; The detection module is used to detect defect depth, circumferential and axial defect sizes according to defect echo signal information.

Images