Off-line acoustic emission detection system and method for bottom plate of oil storage tank

Abstract

The invention relates to an oil storage tank bottom plate off-line acoustic emission detection system and method, and belongs to the field of oil storage tank detection. According to the system, the mode that in the traditional acoustic emission detection process, an acoustic emission sensor arranged in a dangerous area, a detection host arranged in a safe area and an analysis computer are connected in real time is changed; the acoustic emission detection device is moved to a safe area, detection data are downloaded to the analysis computer and analyzed and processed by the data processing system, real-time connection between the acoustic emission detection device and the detection host and between the acoustic emission detection device and the analysis computer is not needed, and the problem that signal attenuation is serious when a transmission cable between the to-be-detected equipment in a dangerous area and the detection host is too long can be effectively solved. The device can be used for safe and high-quality acoustic emission detection of equipment such as a cave depot oil tank far away from a safe area.

Description

Technical Field

[0001] The present invention belongs to the field of storage tank detection, and particularly relates to an offline acoustic emission detection system and method for the bottom plate of a storage tank. Background Art

[0002] As a dynamic non-destructive testing technology, acoustic emission detection technology has low detection economic cost and small workload. At the same time, it has the ability to monitor defects in real time and dynamically, which is difficult to achieve by other non-destructive testing methods. The acoustic emission wave comes from the defect itself rather than the outside, with higher sensitivity and recognition, and there is no need to stop production and open the tank, etc. Therefore, acoustic emission detection technology is widely used in the field of detection of atmospheric vertical storage tanks and has extremely high application value in the health management and maintenance decision-making of storage tanks.

[0003] Existing multi-channel acoustic emission detection instruments mostly adopt a technical mode of parallel driving of multiple sensor signal acquisition, conversion and storage by a single detection host; intrinsically safe acoustic emission sensors with pre-amplification functions are placed in the dangerous area to sense signals; non-explosion-proof detection devices such as detection hosts and analysis computers that are connected to the acoustic emission sensors in real time are placed in the safe area, and the acoustic emission sensors are powered and the detection signals are received through a signal isolation safety barrier. This detection mode has the following disadvantages: 1. The on-site equipment deployment range is large, and the equipment connection distance is long. Each channel cable needs 60 - 120m to transmit the signal to the safe area, which is time-consuming and laborious to install and withdraw in limited spaces such as tank rooms and tunnels.

[0004] 2. There are many connection endpoints between the detection system units such as acoustic emission sensors, detection hosts, and analysis computers, which not only affects the explosion-proof safety and signal signal-to-noise ratio, but also easily causes interface damage due to frequent disassembly and assembly.

[0005] 3. The maximum distance for remote transmission of acoustic emission signals using coaxial cables generally should not exceed 200m, otherwise the signal will be severely attenuated. And the distance from the oil tank in the domestic oil storage cavern to the safe area outside the cave often far exceeds this length.

[0006] In summary, this kind of acoustic emission detection system cannot meet the detection requirements of oil tanks in caverns. Summary of the Invention

[0007] The purpose of the present invention is to provide an offline acoustic emission detection system and method for the bottom plate of a storage tank, which has a short on-site layout connection distance and few connection endpoints and is suitable for acoustic emission detection of oil tanks in caverns.

[0008] To achieve the above object, the present invention provides the following technical solutions: An offline acoustic emission detection system for the bottom plate of a storage tank, comprising a synchronization device, a data analysis and processing system, and an acoustic emission detection device arranged around the storage tank; The acoustic emission detection device includes a housing, as well as a power module, an integrated control module, and a storage medium disposed in the housing. The power module and the storage medium are electrically connected to the integrated control module; One side of the housing is provided with an indicator light module, a data transmission interface, and a power switch that are electrically connected to the integrated control module; the data transmission interface is also a charging interface. Connecting a charging cable can use the 220V power supply to charge the acoustic emission detection device; the other side of the housing is provided with a start button, a sensor interface, and a synchronization interface. The sensor interface is electrically connected to the acoustic emission sensor; the start button, the sensor interface, and the synchronization interface are electrically connected to the integrated control module; The acoustic emission sensors are circumferentially equidistantly and equi-heightedly arranged on the outer wall of the oil storage tank through magnetic clamping fixtures; The synchronization device includes a synchronizer and synchronization cables. The synchronization cables connect each acoustic emission detection device in series through the synchronization interface and are electrically connected to the synchronizer. The acoustic emission detection device is electrically connected to the data analysis and processing system through the data transmission interface.

[0009] Preferably, the offline acoustic emission detection system for the bottom plate of the oil storage tank further includes an auxiliary device. The auxiliary device includes a grounding resistance tester and an oil and gas concentration detector, which are used to detect the grounding resistance of the oil storage tank and the oil and gas concentration on site.

[0010] Further, the housing is milled from a whole aluminum ingot by a CNC machining center. The interior of the housing is integrally potted with an insulating, heat-conducting, and sealing adhesive. The surface of the housing is treated with anodic oxidation and blackening and is provided with heat dissipation fins.

[0011] Further, the indicator light module is provided with a protective cover; the data transmission interface and the power switch are arranged side by side and are provided with a protective cover in total.

[0012] Further, the indicator light module includes a power indicator light (white), a breathing light (white), a collection status light (green), an abnormal indicator light (red), a synchronization signal indicator light (orange), and a coupling light (blue); the breathing light is also an impact indicator light. When an impact signal is collected, the indicator light flashes red.

[0013] Further, two synchronization interfaces are provided, which are respectively used for input and output.

[0014] Further, a pre-signal amplifier is provided on the acoustic emission sensor.

[0015] Further, a handle is provided on the housing.

[0016] An offline acoustic emission detection method for the bottom plate of an oil storage tank, which is applied to the above detection system, includes the following steps: Step 1: Circumferentially install each acoustic emission detection device around the storage tank. Install the acoustic emission sensors circumferentially at equal distances and equal heights on the outer wall of the storage tank through magnetic clamping fixtures, and connect each acoustic emission detection device in series through a synchronization cable and connect it to a synchronizer; Step 2: Start the acoustic emission detection devices of each channel and enter the acquisition state; Step 3: Start the synchronizer to make the acoustic emission detection devices of each channel enter the offline synchronous acquisition state. After the signal acquisition is completed, turn off the acoustic emission detection devices of each channel; Step 4: Connect each acoustic emission detection device to the data analysis and processing system in turn through a data transmission interface to extract the acquired information; Step 5: Conduct a correlation analysis on the acquired information of each channel to check the synchronous time difference of each channel; if the synchronous time difference of each channel for the same acoustic emission signal source does not exceed the set value of 200 microseconds, the offline synchronous acquisition is effective; Step 6: Fill in the detection parameters and then export the detection report.

[0017] Specifically, the detection parameters include the material, radius, wave velocity of the storage tank, as well as the number and distribution form of the acoustic emission detection devices.

[0018] The beneficial effects of the present invention are as follows: Improve the structure of the traditional single detection host controlling multi-channel signal acquisition, conversion, and storage to independent acquisition, conversion, and storage of each acoustic emission detection device, and perform clock synchronization of each acoustic emission detection device through a synchronization device; change the mode of real-time connection between the acoustic emission sensors placed in the dangerous area and the detection host and analysis computer placed in the safe area during the traditional acoustic emission detection process. After each acoustic emission detection device finishes collecting signals in the dangerous area, move it to the safe area, download the detection data to the analysis computer, and analyze and process it by the data processing system. There is no need for real-time connection between the acoustic emission detection device and the detection host and analysis computer, which can effectively overcome the problem of serious signal attenuation when the transmission cable length between the equipment to be detected in the dangerous area and the detection host is too long, and improve the applicability and reliability of the acoustic emission detection technology for detecting equipment such as underground storage tanks far from the safe area.

[0019] The above description is only an overview of the technical solution of the present invention. In order to be able to understand the technical means of the present invention more clearly and implement it according to the content of the specification, the following takes the preferred embodiments of the present invention and combines with the drawings to describe in detail as follows. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a structural diagram of an acoustic emission detection device shown in an embodiment of the present invention; Figure 2 It is a working state schematic diagram of an offline acoustic emission detection system for the bottom plate of a storage tank shown in an embodiment of the present invention; Figure 3 This is the working flowchart of the off-line acoustic emission detection system for the bottom plate of an oil storage tank shown in an embodiment of the present invention; Figures 4-1 to 4-6 This is the flowchart of step 7 of the off-line acoustic emission detection method for the bottom plate of an oil storage tank shown in Embodiment 2 of the present invention, where: Figure 4-1 : Create a bottom tank positioning map; Figure 4-2 : Automatically arrange sensors; Figure 4-3 : Position sensor setting; Figure 4-4 : Bottom tank positioning map attribute setting; Figure 4-5 : Select the export report command; Figure 4-6 : Fill in the basic report information and generate a PDF report.

[0021] Explanation of attached drawing signs: 1. Start button; 2. Sensor interface; 3. Synchronization interface; 4. Acoustic emission sensor; 5. Low-noise signal line; 6. Data transmission interface and power switch module; 7. Indicator light module; 8. Shell; 9. Handle; 10. Heat dissipation fins. Detailed implementation manners

[0022] Next, the technical solutions of the present invention will be clearly and completely described in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0023] In the description of the present invention, it should be noted that unless otherwise clearly defined and limited, the terms "installation", "connection", and "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0024] In addition, the technical features involved in different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other. Embodiment

[0025] Please refer to Figure 1-2 , the off-line acoustic emission detection system for the bottom plate of an oil storage tank shown in a preferred embodiment of the present application includes a plurality of acoustic emission detection devices, a synchronization device, and a data processing system.

[0026] The acoustic emission detection device includes a housing 8, as well as a power module, an integrated control module, and a storage medium disposed in the housing 8. The power module, the storage medium are electrically connected to the integrated control module.

[0027] The housing 8 is designed according to explosion-proof standards and is milled from a whole aluminum ingot by a CNC machining center. The surface is treated with anodized blackening and is provided with heat dissipation fins 10 to enhance the heat dissipation effect and prevent zero drift of the acquisition circuit caused by excessive temperature rise.

[0028] On one side of the housing 8, an indicator light module 7, a data transmission interface, and a power switch module 6 electrically connected to the above integrated control module are provided, and a protective cover is provided to protect them. The indicator light module 7 includes: Power indicator light (white): The light is on after pressing the power switch.

[0029] Breathing light (white): When the start button 1 is pressed, the indicator light will turn green and will flash after waiting for about 10 s, indicating that the hardware starts up normally. Press the start button 1 again to enter the acquisition state, and the indicator light flashes red when an impact signal is acquired.

[0030] Acquisition status indicator light (green): The indicator light is on after pressing the start button 1.

[0031] Abnormal indicator light (red): Lights up when an abnormality in the storage medium or the device is detected.

[0032] Synchronization signal indicator light (orange): The indicator light flashes after signal synchronization.

[0033] Coupling light (blue): When the signal exceeds 90 dB, the blue light is on and flashes.

[0034] On the other side of the housing 8, a start button 1, a sensor interface 2, and a synchronization interface 7 are provided. The sensor interface 2 is connected to an acoustic emission sensor 4 through a low-noise signal line 5; the start button 1, the sensor interface 2, and the synchronization interface 7 are all electrically connected to the integrated control module.

[0035] It should be noted that two synchronization interfaces 7 are provided, which are used as input and output terminals respectively.

[0036] Specifically, a pre-signal amplifier is also provided on the acoustic emission sensor 4.

[0037] Specifically, the acoustic emission detection device is designed based on an embedded system composed of SOC (single chip containing ARM and FPGA) and LINUX, and is provided with a built-in clock.

[0038] Specifically, a handle 9 is also provided on the housing 8 for convenient operation and transfer.

[0039] The synchronization device includes a synchronizer and multiple synchronization cables. The synchronization cables connect each acoustic emission detection device in series through a synchronization interface 7 and are connected to the synchronizer.

[0040] Specifically, the working principle of the above synchronization device is as follows: During the detection process, all acoustic emission detection devices perform A / D sampling using their own clocks. To ensure the accuracy and precision of positioning, a synchronization time correction signal of 100 Hz is additionally added during acquisition. The synchronizer sends a synchronization pulse once every 10 ms. Each time a synchronization pulse is received, the clocks of the acoustic emission detection devices are synchronized once. At other times, each acoustic emission detection device times according to its internal quartz crystal oscillator; considering the frequency stability of the quartz crystal of ±20 ppm, the time error of each acoustic emission detection device is ±10 ms × 20 × 10 -6 = ±0.2 us. After detection, the synchronization error of the acoustic emission detection devices in each channel is ±0.4 us; calculated according to the propagation speed of sound waves in steel of 5.9 mm / us: 5.9 mm / us × 0.8 us = 4.72 mm ≈ 5 mm.

[0041] In summary, with the assistance of the synchronization device, the acoustic emission detection system can detect leakage points with a length of more than 5 mm.

[0042] Preferably, the offline acoustic emission detection system for the bottom plate of the storage tank shown in this application further includes an auxiliary device. The auxiliary device includes a grounding resistance tester and an oil and gas concentration detector, which are used to detect the grounding resistance of the storage tank and the oil and gas concentration on site to ensure the safety of the detection operation.

[0043] Working principle: Please refer to Figure 2 , a plurality of acoustic emission detection devices are arranged circumferentially on the storage tank to be measured. The acoustic emission sensors 4 are circumferentially and equidistantly installed on the outer wall of the storage tank at the same height through magnetic adsorption jigs, and each acoustic emission detection device is connected in series and synchronized through a synchronization device.

[0044] Subsequently, the acoustic emission detection device is started to detect and collect the acoustic emission signals generated by the leakage and corrosion of the bottom plate in the storage tank, and the collected signals are stored in the storage medium.

[0045] After the acquisition is completed, the collected information is transmitted to the data analysis and processing system through the data transmission interface 4, and the collected information is analyzed, integrated, and finally a detection report is obtained. Embodiment

[0046] On the basis of Embodiment 1, the above data analysis and processing system is introduced in detail. The system includes the following functions: a. Interface visualization: Visually model the structural parameters of the storage tank and the measuring point positions; b. Leak detection ability: It can detect leaks with a length of 5 mm or more. c. Tank bottom condition assessment ability: Perform multi-channel fusion processing on the acoustic emission data collected from the measuring points to determine whether there are leaks or weak parts on the bottom of the storage tank, the size and location of the leaks or weak parts. d. Engineering document management: Establish an oil depot detection project to comprehensively manage the basic parameters, acoustic emission detection data, and detection results of the storage tanks to be inspected. e. Acoustic emission detection data management: Associate, label, and store the full-frequency acoustic emission detection data in place. f. Acoustic emission data analysis and processing: It can simultaneously collect / display / store three types of data: characteristic parameters, waveforms, and full waveforms; call data processing algorithms to perform multi-channel fusion processing on the acoustic emission detection data, and output location maps, amplitude distribution maps, signal-time distribution maps, etc. g. Output of acoustic emission detection report for storage tanks: Call the built-in detection report template in standard format, automatically fill in the results of acoustic emission data analysis, and automatically generate a tank bottom condition assessment report for the storage tank (including the five-level safety status of the tank bottom plate, the location of the weak area, and give treatment suggestions, etc.). h. Information management of oil depot facilities and equipment (storage tanks): Establish a data interface with the oil depot facilities and equipment management information system to associate and manage the acoustic emission detection data and condition assessment reports of the storage tanks. i. Detection log management: Establish an acoustic emission detection work log for the storage tank to record relevant matters during the detection process. j. System maintenance: Complete system settings and maintenance management. k. User management: Complete user registration, login, and maintenance management.

[0047] The system performs visual modeling on the structural parameters and measuring point positions of the storage tank by analyzing and processing the signals collected by the acoustic emission detection device, performs multi-channel fusion processing on the acoustic emission data collected from the measuring points on the tank wall, determines whether there are leaks or weak parts on the bottom of the storage tank, the size and location of the leaks or weak parts, and gives a tank bottom condition assessment report, visualizes the collected information, and improves the reliability of the detection.

[0048] Specifically, based on the above embodiments, the offline acoustic emission detection method for the bottom plate of the storage tank shown in this application includes the following steps: Step 1: Install each acoustic emission detection device circumferentially around the storage tank, install the acoustic emission sensors circumferentially at equal distances and heights on the outer wall of the storage tank through magnetic clamping fixtures, and connect each acoustic emission detection device in series through a synchronous cable and connect it to the synchronizer.

[0049] Step 2: Start the acoustic emission detection devices of each channel and enter the acquisition state.

[0050] Step 3: Start the synchronizer to make the acoustic emission detection devices of each channel enter the offline synchronous acquisition state. After the signal acquisition is completed, turn off the acoustic emission detection devices of each channel.

[0051] Step 4: Connect each acoustic emission detection device to the data analysis and processing system in sequence through the data transmission interface, download the Bin files collected offline from all channels in sequence, and save them under the folder.

[0052] Step 5: Sort the bin files according to the channel number and convert them into the PXD format.

[0053] Step 6: Conduct a correlation analysis on the acquisition information of each channel to check the synchronous time difference of each channel; the synchronous time difference of each channel for the same acoustic emission signal source does not exceed the set value of 200 microseconds, and the offline synchronous acquisition is effective.

[0054] Step 7: Fill in the detection parameters and then export the detection report.

[0055] Specifically, the detection parameters in Step 7 include the material, radius, wave velocity of the storage tank, as well as the number and distribution form (circumferential distribution) of the acoustic emission detection devices.

[0056] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope recorded in this specification.

[0057] The above-described embodiments only represent several implementation manners of the present invention. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention patent should be subject to the appended claims.

Claims

1. An off-line acoustic emission detection system for the bottom plate of an oil storage tank, characterized in that It includes a synchronization device, a data analysis and processing system, and an acoustic emission detection device arranged around the oil storage tank; The acoustic emission detection device includes a housing, and a power module, an integrated control module, and a storage medium arranged in the housing. The power module, the storage medium are electrically connected to the integrated control module; One side of the housing is provided with an indicator light module, a data transmission interface, and a power switch that are electrically connected to the integrated control module; the data transmission interface also serves as a charging interface for charging the acoustic emission detection device; the other side of the housing is provided with a start button, a sensor interface, and a synchronization interface. The sensor interface is electrically connected to an acoustic emission sensor; the start button, the sensor interface, and the synchronization interface are electrically connected to the integrated control module; The acoustic emission sensors are circumferentially equidistantly and equidistantly arranged on the outer wall of the oil storage tank through magnetic clamping fixtures; The synchronization device includes a synchronizer and synchronization cables. The synchronization cables connect each acoustic emission detection device in series through the synchronization interface and are electrically connected to the synchronizer. The acoustic emission detection device is electrically connected to the data analysis and processing system through the data transmission interface.

2. The offline acoustic emission detection system for the bottom plate of an oil storage tank according to claim 1, wherein It also includes an auxiliary device. The auxiliary device includes a grounding resistance tester and an oil and gas concentration detector for detecting the grounding resistance of the oil storage tank and the oil and gas concentration on site.

3. The offline acoustic emission detection system for the bottom plate of the storage oil tank according to claim 1, wherein The housing is milled from a whole aluminum ingot through a CNC machining center. The interior of the housing is integrally potted with an insulating and heat-conducting sealant. The surface of the housing is treated with anodic oxidation and blackening and is provided with heat dissipation fins.

4. The offline acoustic emission detection system for the bottom plate of an oil storage tank according to claim 1, wherein The indicator light module is provided with a protective cover; the data transmission interface and the power switch are arranged side by side and are provided with protective covers.

5. The offline acoustic emission detection system for the bottom plate of an oil storage tank according to claim 1, characterized in that, The indicator light module includes a power indicator light, a breathing light, a collection status light, an abnormal indicator light, a synchronization signal indicator light, and a coupling light; the breathing light also serves as an impact indicator light and flashes when an impact signal is collected.

6. The off-line acoustic emission detection system for the bottom plate of an oil storage tank according to claim 1, wherein Two synchronization interfaces are provided, which serve as an input end and an output end respectively.

7. The offline acoustic emission detection system for the bottom plate of an oil storage tank according to claim 1, wherein A pre-signal amplifier is arranged on the acoustic emission sensor.

8. The offline acoustic emission detection system for the bottom plate of an oil storage tank according to claim 1, characterized in that, A handle is arranged on the housing.

9. An off-line acoustic emission detection method for the bottom plate of an oil storage tank, which is applied to the off-line acoustic emission detection system for the bottom plate of an oil storage tank as described in any one of claims 1-7, and is characterized in that, It includes the following steps: Step 1: Install each acoustic emission detection device circumferentially around the oil storage tank. Install the acoustic emission sensors circumferentially equidistantly and equidistantly on the outer wall of the oil storage tank through magnetic clamping fixtures. Connect each acoustic emission detection device in series through synchronization cables and connect them to the synchronizer; Step 2: Start the acoustic emission detection devices of each channel and enter the collection state; Step 3: Start the synchronizer to make the acoustic emission detection devices of each channel enter the offline synchronous collection state. After the signal collection is completed, turn off the acoustic emission detection devices of each channel; Step 4: Each acoustic emission detection device is sequentially connected to the data analysis and processing system through the data transmission interface to extract the collected information; Step 5: Conduct a correlation analysis on the collected information of each channel to check the synchronous time difference of each channel; if the synchronous time difference of each channel for the same acoustic emission signal source does not exceed the set value of 200 microseconds, the offline synchronous collection is effective; Step 6: Fill in the detection parameters and then export the detection report.

10. The method for off-line acoustic emission detection of the bottom plate of an oil storage tank according to claim 8, characterized in that, The detection parameters in Step 6 include the material, radius, wave velocity of the oil storage tank, and the quantity and distribution form of the acoustic emission detection devices.

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