High-temperature pipeline defect long-distance on-line monitoring device

Abstract

A long-distance on-line monitoring device for defects of a high-temperature pipeline relates to the technical field of pipeline nondestructive testing, can be applied to on-site monitoring of the high-temperature pipeline for a long time so as to realize on-line monitoring of large-range defects of the high-temperature pipeline, and has higher sensitivity. In the long-distance online monitoring device for the defects of the high-temperature pipeline, a control system is connected with a high-voltage excitation system and a wireless signal transmission system; the high-voltage excitation system is driven by a pulse signal and is connected with the probe combination and the assembly bracket; the probe combination and assembly bracket is sequentially connected with a signal filtering and amplifying system, a signal acquisition system and a wireless signal transmission system; the probe combination and assembly support comprises a probe supporting frame circumferentially installed on the outer wall of a monitored high-temperature pipeline and a plurality of ultrasonic guided wave probes assembled on the probe supporting frame, and the ultrasonic guided wave probes are connected in parallel. A piezoelectric material of a piezoelectric sensor in the ultrasonic guided wave probe is an AIN material, and an AIN piezoelectric sensor is manufactured by adopting an MEMS (Micro Electro Mechanical System) technology.

Description

Technical Field

[0001] The invention relates to the technical field of pipeline nondestructive testing and status monitoring, and in particular to a long-distance online monitoring device for high-temperature pipeline defects. Background Art

[0002] At present, high temperature pressure pipelines are widely used in industrial fields such as oil and natural gas extraction and transportation, chemical production, power plant boilers and thermal systems. However, due to the long-term exposure to high temperature and high pressure, high temperature pressure pipelines may have defects such as cracks, wall corrosion and thinning. If they are not discovered and repaired in time, they will eventually lead to leakage of the internal transport medium and cause catastrophic accidents.

[0003] In practice, for high-temperature pipeline defect detection, the economic advantage of testing when the pipeline is in a high temperature state is far greater than lowering the pipeline temperature to room temperature before testing; and cooling the pipeline means that the continuously running production equipment needs to stop working, which will cause relatively large economic losses. Therefore, it is of great practical significance to conduct online monitoring of its defects when the pipeline is in a high temperature state.

[0004] In the existing technology, ultrasonic guided wave detection technology has the advantages of long-distance and large-scale detection, and is suitable for pipeline detection in various complex environments such as buried pipelines and pipelines that pass through and cross. It can screen various types of defects such as cracks, pores, and wall thickness reduction in a large area. Specifically, when ultrasonic guided wave detection is performed on pipelines, there are three main types of sensors currently used: piezoelectric sensors, electromagnetic ultrasonic sensors, and magnetostrictive sensors.

[0005] Among them, the research and application of piezoelectric sensors are the most extensive. They have high energy conversion efficiency, a wide range of applicable excitation frequencies, and long transmission distances for ultrasonic guided wave signals. However, there are two limitations for the detection of high-temperature pipelines. One is the development of high-temperature coupling agents, and the other is the development of high-temperature resistant piezoelectric materials. The effective operating temperature range of piezoelectric ultrasonic probes is mainly limited by the performance of piezoelectric materials. Piezoelectric materials only have piezoelectric effect within a certain temperature range. When the temperature is greater than a certain critical temperature, namely the Curie temperature, the electric dipoles in the piezoelectric material chip will return to a disordered state, thereby affecting its piezoelectric performance. Generally speaking, the safe operating temperature limit of piezoelectric ultrasonic probes is usually between 0°C and 1 / 2 of the Curie temperature. However, the specific effective operating temperature range may vary due to different piezoelectric materials, probe designs, and manufacturing processes. In actual applications, piezoelectric ultrasonic probes are generally suitable for temperatures between -20°C and 70°C. Exceeding this range may cause the probe's accuracy to decrease or malfunction.

[0006] The main advantage of electromagnetic ultrasonic sensors is that they are non-contact and have a certain lift-off distance, but their transduction efficiency is relatively low, resulting in a short detection transmission distance. In addition, magnetostrictive sensors can achieve non-contact detection and adapt to harsh environments such as high temperature corrosion, but their transduction efficiency is lower than that of piezoelectric sensors and their sensitivity to defect detection is lower.

[0007] In summary, for the application scenario of on-site monitoring of high-temperature pipeline defects, the limitations of piezoelectric sensors can be overcome by developing high-temperature coupling agents and high-temperature piezoelectric materials. The electromagnetic ultrasonic sensors and magnetostrictive sensors are essentially low in conversion efficiency between electrical energy and acoustic energy, and there are great limitations in further improving the detection sensitivity and detection range. At the same time, electromagnetic detection technology requires the use of permanent magnets on the detection coil to set an external magnetic field. The permanent magnet will experience magnetic field degradation as the use time increases in high-temperature environments, which will eventually lead to a gradual decrease in monitoring sensitivity. In addition, for overhead and buried high-temperature pipelines, frequent replacement of monitoring components during long-term online monitoring will cause a relatively large amount of additional workload. Summary of the invention

[0008] The object of the present invention is to provide a long-distance online monitoring device for high-temperature pipeline defects, which can be used for long-term on-site monitoring of high-temperature pipelines to achieve online monitoring of large-scale defects in high-temperature pipelines and has high sensitivity.

[0009] In order to achieve the above object, the present invention adopts the following technical scheme: A long-distance online monitoring device for high-temperature pipeline defects, comprising: a control system, and a high-voltage excitation system and a wireless signal transmission system connected to the control system; the high-voltage excitation system is driven by a pulse signal and connected to a probe assembly and an assembly bracket; the probe assembly and the assembly bracket are connected to a signal filtering and amplifying system, the signal filtering and amplifying system is connected to a signal acquisition system, and the signal acquisition system is connected to the wireless signal transmission system; The probe assembly and assembly bracket include: a probe support frame circumferentially mounted on the outer wall of the monitored high-temperature pipeline, and a plurality of ultrasonic waveguide probes mounted on the probe support frame, and the plurality of ultrasonic waveguide probes are connected in parallel with each other; the piezoelectric material of the piezoelectric sensor in the ultrasonic waveguide probe is AIN material, and the AIN piezoelectric sensor is manufactured using MEMS technology; After the high-voltage signal emitted by the high-voltage excitation system is applied to the ultrasonic guided wave probe, ultrasonic guided waves are stimulated inside the pipe wall of the monitored high-temperature pipe and propagated along the extension direction of the pipe; the ultrasonic guided wave signal is reflected when encountering internal defects of the pipe and welds at the pipe connection, and the reflected signal is received by the ultrasonic guided wave probe connected in parallel and enters the signal filtering and amplifying system; the output signal of the signal filtering and amplifying system is collected by the signal acquisition system and transmitted to the remote monitoring terminal through the wireless signal transmission system under the control of the control system.

[0010] In actual application, the control system is built based on the STM32 chip, which is used to send pulse signals and drive the high-voltage excitation system, and at the same time control the wireless signal transmission system to send the ultrasonic guided wave transmission signal and reflection signal received by the signal acquisition system to the remote monitoring terminal.

[0011] The boost circuit in the high-voltage excitation system uses the LT3580 chip to increase the +5V voltage of the input port VIN to the +350V voltage of the VOUT interface, and connects it to the HV350 in the excitation control circuit; The excitation control circuit adopts the UCC21520 chip, one side of the UCC21520 chip is a low-voltage end, and the other side is a high-voltage end, which can realize the control of the high-voltage end by the low-voltage signal; the control signal is a square wave pulse signal with adjustable frequency, and the frequency range is 10kHz-500kHz; Two UCC21520 chips control the opening and closing of four MOSFET tubes, and the model of the MOSFET tube is AOT20S60L. The ultrasonic waveguide probe is connected to the HDR1 port, and a sinusoidal excitation voltage signal is output at the same time, and the peak-to-peak voltage can reach 700V.

[0012] Specifically, in the ultrasonic guided wave probe, a certain thickness of SiO is deposited on the upper surface of the Si wafer by plasma enhanced chemical vapor deposition. 2 Layer, as an insulating isolation layer; The magnetron sputtering method was used to deposit SiO 2 A Mo-AlN-Mo sandwich piezoelectric structure with a certain thickness is sequentially grown on the layers; The first mask is used for photolithography, and the upper electrode Mo is patterned by ion beam etching; Plasma enhanced chemical vapor deposition was used to deposit SiO on the entire upper surface. 2 layer, and serves as an upper insulating layer; For SiO deposited on the upper surface 2 The SiO 2The layer is used as a mask for etching the piezoelectric layer AlN in the next step; The piezoelectric layer AlN is wet-etched, and an alkaline solution is used to etch the AlN to expose the Mo layer of the lower electrode; Using the third photolithography mask, the SiO deposited on the upper surface 2 The layer is etched to expose the Mo layer of the upper electrode; A resonant cavity is etched on the back of the bottom Si wafer using deep reactive ion etching, and serves as a release cavity for vibration energy. Lead wires are welded to the exposed parts of the upper and lower Mo electrode layers by brazing.

[0013] Furthermore, the Si support legs of the ultrasonic guided wave probe located on the lower surface are inserted into the grooves located on the upper surface of the probe support frame and fixed using high temperature resistant glue.

[0014] Furthermore, the probe support frame is mainly composed of a first support frame and a second support frame of two stainless steel materials of the same structure, and the interface between the first support frame and the second support frame is connected by bolts and nuts; The first support frame and the second support frame are respectively processed with a plurality of threaded holes, and the threaded holes are used to install the ultrasonic guided wave probe.

[0015] In actual application, the system software of the remote monitoring terminal is installed on a personal computer, and the personal computer receives the ultrasonic guided wave signal sent by the wireless signal transmission system through a WIFI receiving device, and displays it on the personal computer; The distance between the probe assembly and the assembly bracket and the nearest pipe connection weld is determined. The transmission speed of the ultrasonic guided wave can be calculated based on the time interval between the reflection signal and the excitation signal at the weld. When the sound wave transmission speed is known, the position of the defect can be calculated based on the time interval between the defect reflection signal and the excitation signal. The size of the defect can be determined based on the amplitude of the defect reflection signal.

[0016] Among them, in the signal filtering and amplifying system, a clamping circuit is set at the front stage to limit the voltage amplitude of the incoming signal, and the LT1568 chip is used for signal filtering, and the circuit is designed to be a low-pass filter with a signal cutoff frequency of 500kHz, which matches the highest excitation frequency of the high-voltage excitation system; The AD8606 chip is used to form a secondary amplifier circuit to amplify the received ultrasonic guided wave signal and achieve a signal amplitude greater than the minimum signal amplitude that can be collected by the signal collection system.

[0017] Specifically, the signal acquisition system is implemented by an AD7626 chip, the wireless signal transmission adopts a WIFI transmission mode, and the wireless signal transmission system is implemented by an ESP32S3 chip; The control system controls the opening and closing of the ESP32S3 chip. After the ESP32S3 chip is turned on, the AD7626 chip is controlled to collect ultrasonic guided wave signals, and the collected digital signals are sent to the remote monitoring terminal.

[0018] Furthermore, the high-temperature pipeline defect long-distance online monitoring device also includes: a power supply system, and the power supply system is implemented by a semiconductor refrigeration sheet; A plurality of the semiconductor refrigeration sheets are attached to the outer surface of the monitored high-temperature pipeline and connected in series with each other, and the semiconductor refrigeration sheets generate electricity by utilizing the temperature difference between the upper and lower surfaces; The electricity generated by the semiconductor refrigeration chip is stored in a lithium-ion battery, and has a charge and discharge management circuit and a voltage conversion circuit, which can output 5V and 3.3V voltages at the same time to meet the power supply requirements of the entire monitoring device.

[0019] Furthermore, the circuit board is encapsulated in an explosion-proof housing, and the circuit is connected to the ultrasonic waveguide probe via a wiring terminal.

[0020] Compared with the prior art, the high-temperature pipeline defect long-distance online monitoring device described in the present invention has the following advantages: In the long-distance online monitoring device for high-temperature pipeline defects provided by the present invention, since the control system is connected to a high-voltage excitation system and a wireless signal transmission system, the high-voltage excitation system is driven by a pulse signal and connected to a probe assembly and an assembly bracket, the probe assembly and the assembly bracket are connected to a signal filtering and amplifying system, the signal filtering and amplifying system is connected to a signal acquisition system, and the signal acquisition system is connected to the wireless signal transmission system; the probe assembly and the assembly bracket include: a probe support frame circumferentially installed on the outer wall of the monitored high-temperature pipeline, and a plurality of ultrasonic guided wave probes assembled on the probe support frame, and the plurality of ultrasonic guided wave probes are connected in parallel with each other, the piezoelectric material of the piezoelectric sensor in the ultrasonic guided wave probe is made of AIN material, and the AIN piezoelectric sensor is manufactured using MEMS technology; and AlN (aluminum nitride) is a piezoelectric material with an extremely high Curie temperature, and its Curie temperature is usually greater than 1000°C, which A characteristic enables AlN to still maintain stable piezoelectric properties in a high-temperature environment, thus playing an important role in applications requiring high-temperature stability; therefore, in the long-distance online monitoring device for high-temperature pipeline defects provided by the present invention, after the high-voltage signal emitted by the high-voltage excitation system is applied to the ultrasonic waveguide probe, ultrasonic waveguides are stimulated inside the pipe wall of the monitored high-temperature pipe and propagated along the extension direction of the pipe. The ultrasonic waveguide signal is reflected when encountering internal defects of the pipe and welds at the pipe connection. The reflected signal is received by the ultrasonic waveguide probe connected in parallel and enters the signal filtering and amplifying system. The output signal of the signal filtering and amplifying system is collected by the signal acquisition system and, under the control of the control system, is transmitted to the remote monitoring terminal through the wireless signal transmission system, so that it can be applied to the on-site monitoring of high-temperature pipes for a long time to realize the online monitoring of large-scale defects of high-temperature pipes, and has high sensitivity. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 A schematic diagram of the structural framework of a long-distance online monitoring device for high-temperature pipeline defects provided by an embodiment of the present invention; Figure 2 A schematic diagram of the structure of a probe assembly and an assembly bracket in a high-temperature pipeline defect long-distance online monitoring device provided by an embodiment of the present invention; Figure 3 A schematic diagram of the structure of a boost circuit of a high-voltage excitation system in a high-temperature pipeline defect long-distance online monitoring device provided in an embodiment of the present invention; Figure 4 A schematic diagram of the structure of an excitation control circuit of a high-voltage excitation system in a long-distance online monitoring device for high-temperature pipeline defects provided by an embodiment of the present invention; Figure 5 A schematic diagram of the circuit structure of a signal filtering and amplifying system in a high-temperature pipeline defect long-distance online monitoring device provided by an embodiment of the present invention; Figure 6A schematic diagram of the circuit structure of a signal acquisition system and a wireless signal transmission system in a high-temperature pipeline defect long-distance online monitoring device provided in an embodiment of the present invention.

[0022] Reference numerals: 1-control system; 2-high voltage excitation system; 3-wireless signal transmission system; 4-probe assembly and assembly bracket; 41-probe support frame; 411-first support frame; 412-second support frame; 42-ultrasonic guided wave probe; 5-signal filtering and amplification system; 6-signal acquisition system; 7-monitored high-temperature pipeline; 8-power supply system. DETAILED DESCRIPTION

[0023] For ease of understanding, the long-distance online monitoring device for high-temperature pipeline defects provided by an embodiment of the present invention is described in detail below in conjunction with the accompanying drawings.

[0024] The embodiment of the present invention provides a long-distance online monitoring device for high-temperature pipeline defects, such as Figure 1-Figure 6 As shown, it includes: a control system 1, and a high-voltage excitation system 2 and a wireless signal transmission system 3 connected to the control system 1; the high-voltage excitation system 2 is driven by a pulse signal and connected to a probe assembly and an assembly bracket 4; the probe assembly and the assembly bracket 4 are connected to a signal filtering and amplifying system 5, the signal filtering and amplifying system 5 is connected to a signal acquisition system 6, and the signal acquisition system 6 is connected to the wireless signal transmission system 3; The probe assembly and assembly bracket 4 includes: a probe support frame 41 circumferentially mounted on the outer wall of the monitored high-temperature pipeline 7, and a plurality of ultrasonic waveguide probes 42 mounted on the probe support frame 41, and the plurality of ultrasonic waveguide probes 42 are connected in parallel with each other; the piezoelectric material of the piezoelectric sensor in the ultrasonic waveguide probe 42 is made of AIN material, and the AIN piezoelectric sensor is manufactured using MEMS technology; After the high-voltage signal emitted by the high-voltage excitation system 2 is applied to the ultrasonic guided wave probe 42, ultrasonic guided waves are stimulated inside the pipe wall of the monitored high-temperature pipe 7 and propagated along the extension direction of the pipe; the ultrasonic guided wave signal is reflected when encountering internal defects of the pipe and welds at the pipe joints, and the reflected signal is received by the parallel ultrasonic guided wave probe 42 and enters the signal filtering and amplifying system 5; the output signal of the signal filtering and amplifying system 5 is collected by the signal acquisition system 6 and transmitted to the remote monitoring terminal through the wireless signal transmission system 3 under the control of the control system 1.

[0025] Compared with the prior art, the high-temperature pipeline defect long-distance online monitoring device described in the embodiment of the present invention has the following advantages: In the long-distance online monitoring device for high-temperature pipeline defects provided by an embodiment of the present invention, since the control system 1 is connected to the high-voltage excitation system 2 and the wireless signal transmission system 3, the high-voltage excitation system 2 is driven by a pulse signal and connected to the probe combination and assembly bracket 4, the probe combination and assembly bracket 4 is connected to the signal filtering and amplifying system 5, the signal filtering and amplifying system 5 is connected to the signal acquisition system 6, and the signal acquisition system 6 is connected to the wireless signal transmission system 3; the probe combination and assembly bracket 4 includes: a probe support frame 41 circumferentially installed on the outer wall of the monitored high-temperature pipeline 7, and a plurality of ultrasonic guided wave probes 42 assembled on the probe support frame 41, and the plurality of ultrasonic guided wave probes 42 are connected in parallel with each other, the piezoelectric material of the piezoelectric sensor in the ultrasonic guided wave probe 42 is made of AIN material, and the AIN piezoelectric sensor is manufactured using MEMS technology; and AlN (aluminum nitride) is a piezoelectric material with an extremely high Curie temperature, and its Curie temperature is usually greater than 1000℃, this characteristic enables AlN to still maintain stable piezoelectric properties in a high temperature environment, thus playing an important role in applications requiring high temperature stability; therefore, in the long-distance online monitoring device for high-temperature pipeline defects provided by the embodiment of the present invention, after the high-voltage signal emitted by the high-voltage excitation system 2 is applied to the ultrasonic waveguide probe 42, ultrasonic waveguides are stimulated inside the pipe wall of the monitored high-temperature pipe 7, and propagated along the extension direction of the pipe, and the ultrasonic waveguide signal is reflected when encountering internal defects of the pipe and the weld at the pipe connection, and the reflected signal is received by the parallel ultrasonic waveguide probe 42 and enters the signal filtering and amplifying system 5, and the output signal of the signal filtering and amplifying system 5 is collected by the signal acquisition system 6, and under the control of the control system 1, is transmitted to the remote monitoring terminal through the wireless signal transmission system 3, so that it can be applied to the on-site monitoring of high-temperature pipelines for a long time, so as to realize the online monitoring of large-scale defects of high-temperature pipelines, and has a higher sensitivity.

[0026] In practical application, such as Figure 1-Figure 6 As shown, the control system 1 can be built based on the STM32 chip, used to send pulse signals and drive the high-voltage excitation system 2, and at the same time control the wireless signal transmission system 3 to send the ultrasonic guided wave transmission signal and reflection signal received by the signal acquisition system 6 to the remote monitoring terminal 8; and the model of the STM32 chip that can be selected is STM32F405RGT6.

[0027] Among them, Figure 1-Figure 6 As shown, the boost circuit in the above-mentioned high-voltage excitation system 2 can increase the +5V voltage of the input port VIN to the +350V voltage of the VOUT interface by means of the LT3580 chip, and connect it to the HV350 in the excitation control circuit; The UCC21520 chip can be used in the excitation control circuit. One side of the UCC21520 chip is a low-voltage end and the other side is a high-voltage end, which can realize the control of the high-voltage end by the low-voltage signal; the control signal is a square wave pulse signal with adjustable frequency, and the frequency range can be 10kHz-500kHz; Two UCC21520 chips control the opening and closing of four MOSFET tubes, and the model of the MOSFET tube can be AOT20S60L, and the ultrasonic waveguide probe 42 is connected to the HDR1 port, and a sinusoidal excitation voltage signal is output at the same time, and the peak-to-peak voltage can reach 700V.

[0028] Specifically, Figure 1-Figure 6 As shown, in the ultrasonic guided wave probe 42, a certain thickness of SiO2 can be deposited on the upper surface of the Si wafer by plasma enhanced chemical vapor deposition. 2 Layer, as an insulating isolation layer; Magnetron sputtering can be used to deposit SiO 2 A Mo-AlN-Mo sandwich piezoelectric structure with a certain thickness is sequentially grown on the layers; The first mask plate can be used for photolithography, and the upper electrode Mo can be patterned by ion beam etching; SiO can be deposited on the entire upper surface by plasma enhanced chemical vapor deposition. 2 layer, and serves as an upper insulating layer; The SiO deposited on the upper surface can 2 The SiO 2 The layer is used as a mask for etching the piezoelectric layer AlN in the next step; The piezoelectric layer AlN can be wet-etched, and the AlN is etched using an alkaline solution to expose the Mo layer of the lower electrode; A third photolithography mask can be used to deposit SiO 2 The layer is etched to expose the Mo layer of the upper electrode; A resonant cavity can be etched on the back of the bottom Si wafer using deep reactive ion etching, and used as a release cavity for vibration energy; Lead wires can be welded to the exposed parts of the upper and lower Mo electrode layers by brazing.

[0029] Furthermore, if Figure 1-Figure 6 As shown, the Si support legs of the ultrasonic guided wave probe 42 located on the lower surface can be inserted into the grooves located on the upper surface of the probe support frame 41 and can be fixed using high temperature resistant glue.

[0030] Furthermore, if Figure 1-Figure 6As shown, the probe support frame 41 can be mainly composed of two stainless steel support frames 411 and 412 of the same structure, and the interface between the first support frame 411 and the second support frame 412 can be connected by bolts and nuts; The first support frame 411 and the second support frame 412 may be processed with a plurality of threaded holes respectively, and the threaded holes can be used to install the ultrasonic guided wave probe 42 .

[0031] Furthermore, if Figure 1-Figure 6 As shown, the ultrasonic guided wave probe 42 can be composed of a probe body and a probe bracket connected thereto; a high-temperature coupling agent can be applied to the portion of the probe mounting hole on the probe support frame 41 corresponding to the surface of the monitored high-temperature pipeline 7, and the probe bracket with the probe body mounted thereon is screwed into the probe mounting hole, and the upper surface of the probe body is brought into contact with the surface of the monitored high-temperature pipeline 7; as for the high-temperature coupling agent, the ZGM high-temperature coupling agent developed by the British ACEPOM company can work within a temperature range below 600°C, and for lower temperature ranges, silicone oil, glycerin, etc. can be used as a high-temperature coupling agent.

[0032] In practical application, such as Figure 1-Figure 6 As shown, the system software of the remote monitoring terminal can be installed on a personal computer, and the personal computer can receive the ultrasonic guided wave signal sent by the wireless signal transmission system 3 through a WIFI receiving device and display it on the personal computer; The distance between the probe assembly and the assembly bracket 4 and the nearest pipe connection weld is determined. The transmission speed of the ultrasonic guided wave can be calculated based on the time interval between the reflection signal and the excitation signal at the weld. When the sound wave transmission speed is known, the position of the defect can be calculated based on the time interval between the defect reflection signal and the excitation signal. The size of the defect can be determined based on the amplitude of the defect reflection signal.

[0033] Among them, Figure 1-Figure 6 As shown, since the same set of ultrasonic guided wave probes are used for transmitting and receiving ultrasonic guided wave signals, in order to prevent the high-voltage ultrasonic transmission signal from damaging the signal filtering and amplifying system 5, in the above-mentioned signal filtering and amplifying system 5, a clamping circuit can be set in the front section to limit the voltage amplitude of the incoming signal, and the LT1568 chip can be used for signal filtering, and the circuit is designed to be a low-pass filter, and the signal cutoff frequency can be 500kHz, which matches the highest excitation frequency of the high-voltage excitation system 2; The AD8606 chip can be used to form a secondary amplifier circuit to amplify the received ultrasonic guided wave signal and achieve a signal amplitude greater than the minimum signal amplitude that can be collected by the signal collection system 6.

[0034] Specifically, Figure 1-Figure 6As shown, the signal acquisition system 6 can be implemented by an AD7626 chip, the wireless signal transmission can be transmitted by WIFI, and the wireless signal transmission system 3 can be implemented by an ESP32S3 chip; The control system 1 controls the opening and closing of the ESP32S3 chip. After the ESP32S3 chip is turned on, it controls the AD7626 chip to collect ultrasonic guided wave signals and sends the collected digital signals to the remote monitoring terminal.

[0035] Furthermore, if Figure 1-Figure 6 As shown, the high-temperature pipeline defect long-distance online monitoring device provided by the embodiment of the present invention may also include: a power supply system 8, and the power supply system 8 may be implemented by a semiconductor cooling sheet, so that no external power supply is required; Multiple semiconductor refrigeration sheets can be pasted on the outer surface of the monitored high-temperature pipe 7 and connected in series with each other, so that the semiconductor refrigeration sheets can generate electricity by using the temperature difference between the upper and lower surfaces; in addition, the lower surface of the semiconductor refrigeration sheet is in close contact with the surface of the monitored high-temperature pipe 7, and the upper surface can be exposed to the air. Preferably, a fan can be pasted on the upper surface to further reduce the temperature, so as to increase the temperature difference and increase the power generation.

[0036] The electricity generated by the semiconductor refrigeration chip can be stored in a lithium-ion battery, and can have a charge and discharge management circuit and a voltage conversion circuit, so that it can output 5V and 3.3V voltages at the same time to meet the power supply requirements of the entire monitoring device.

[0037] Furthermore, the circuit board can be encapsulated in an explosion-proof housing, and the circuit and the ultrasonic guided wave probe 42 can be connected through wiring terminals, thereby effectively meeting the explosion-proof requirements of the monitoring site.

[0038] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art who is familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A long-distance online monitoring device for high-temperature pipeline defects, characterized in that: include: A control system, and a high-voltage excitation system and a wireless signal transmission system connected to the control system; the high-voltage excitation system is driven by a pulse signal and is connected to a probe assembly and an assembly bracket; the probe assembly and the assembly bracket are connected to a signal filtering and amplifying system, the signal filtering and amplifying system is connected to a signal acquisition system, and the signal acquisition system is connected to the wireless signal transmission system; The probe assembly and assembly bracket include: a probe support frame circumferentially mounted on the outer wall of the monitored high-temperature pipeline, and a plurality of ultrasonic waveguide probes mounted on the probe support frame, and the plurality of ultrasonic waveguide probes are connected in parallel with each other; the piezoelectric material of the piezoelectric sensor in the ultrasonic waveguide probe is AIN material, and the AIN piezoelectric sensor is manufactured using MEMS technology; After the high-voltage signal emitted by the high-voltage excitation system is applied to the ultrasonic guided wave probe, ultrasonic guided waves are stimulated inside the pipe wall of the monitored high-temperature pipe and propagated along the extension direction of the pipe; the ultrasonic guided wave signal is reflected when encountering internal defects of the pipe and welds at the pipe connection, and the reflected signal is received by the ultrasonic guided wave probe connected in parallel and enters the signal filtering and amplifying system; the output signal of the signal filtering and amplifying system is collected by the signal acquisition system and transmitted to the remote monitoring terminal through the wireless signal transmission system under the control of the control system.

2. The high-temperature pipeline defect long-distance online monitoring device according to claim 1 is characterized in that: The control system is built based on the STM32 chip, and is used to send pulse signals and drive the high-voltage excitation system, while controlling the wireless signal transmission system to send the ultrasonic guided wave transmission signal and reflection signal received by the signal acquisition system to the remote monitoring terminal.

3. The high-temperature pipeline defect long-distance online monitoring device according to claim 1 is characterized in that: The boost circuit in the high-voltage excitation system uses the LT3580 chip to increase the +5V voltage of the input port VIN to the +350V voltage of the VOUT interface, and connects it to the HV350 in the excitation control circuit; The excitation control circuit adopts the UCC21520 chip, one side of the UCC21520 chip is a low-voltage end, and the other side is a high-voltage end, which can realize the control of the high-voltage end by the low-voltage signal; the control signal is a square wave pulse signal with adjustable frequency, and the frequency range is 10kHz-500kHz; Two UCC21520 chips control the opening and closing of four MOSFET tubes, and the model of the MOSFET tube is AOT20S60L. The ultrasonic waveguide probe is connected to the HDR1 port, and a sinusoidal excitation voltage signal is output at the same time, and the peak-to-peak voltage can reach 700V.

4. The high-temperature pipeline defect long-distance online monitoring device according to claim 1 is characterized in that: In the ultrasonic guided wave probe, a SiO2 layer of a certain thickness is deposited on the upper surface of the Si wafer by plasma enhanced chemical vapor deposition as an insulating isolation layer; The Mo-AlN-Mo sandwich piezoelectric structure with a certain thickness is grown on the SiO2 layer in sequence by magnetron sputtering. The first mask is used for photolithography, and the upper electrode Mo is patterned by ion beam etching; A SiO2 layer is deposited on the entire upper surface by plasma enhanced chemical vapor deposition and serves as an upper insulating layer; The SiO2 layer deposited on the upper surface is etched, and the second photolithography mask is used to etch the SiO2 layer as a mask for etching the piezoelectric layer AlN in the next step; The piezoelectric layer AlN is wet-etched, and an alkaline solution is used to etch the AlN to expose the Mo layer of the lower electrode; Using a third photolithography mask, the SiO2 layer deposited on the upper surface is etched to expose the Mo layer of the upper electrode; A resonant cavity is etched on the back of the bottom Si wafer using deep reactive ion etching, and serves as a release cavity for vibration energy. Lead wires are welded to the exposed parts of the upper and lower Mo electrode layers by brazing.

5. The long-distance online monitoring device for high-temperature pipeline defects according to claim 1 or 4 is characterized in that: The Si support legs of the ultrasonic guided wave probe located on the lower surface are inserted into the grooves located on the upper surface of the probe support frame and fixed using high temperature resistant glue.

6. The long-distance online monitoring device for high-temperature pipeline defects according to claim 5 is characterized in that: The probe support frame is mainly composed of a first support frame and a second support frame of two stainless steel materials of the same structure, and the interface between the first support frame and the second support frame is connected by bolts and nuts; The first support frame and the second support frame are respectively processed with a plurality of threaded holes, and the threaded holes are used to install the ultrasonic guided wave probe.

7. The high-temperature pipeline defect long-distance online monitoring device according to claim 1 is characterized in that: In the signal filtering and amplifying system, a clamping circuit is set in the front stage to limit the voltage amplitude of the incoming signal, and the LT1568 chip is used for signal filtering. The circuit is designed to be a low-pass filter, and the signal cutoff frequency is 500kHz, which matches the highest excitation frequency of the high-voltage excitation system. The AD8606 chip is used to form a secondary amplifier circuit to amplify the received ultrasonic guided wave signal and achieve a signal amplitude greater than the minimum signal amplitude that can be collected by the signal collection system.

8. The high-temperature pipeline defect long-distance online monitoring device according to claim 1 is characterized in that: The signal acquisition system is implemented by an AD7626 chip, the wireless signal transmission adopts a WIFI transmission mode, and the wireless signal transmission system is implemented by an ESP32S3 chip; The control system controls the opening and closing of the ESP32S3 chip. After the ESP32S3 chip is turned on, the AD7626 chip is controlled to collect ultrasonic guided wave signals, and the collected digital signals are sent to the remote monitoring terminal.

9. The high-temperature pipeline defect long-distance online monitoring device according to claim 1 is characterized in that: Also includes: A power supply system, wherein the power supply system is implemented by using semiconductor cooling chips; A plurality of the semiconductor refrigeration sheets are attached to the outer surface of the monitored high-temperature pipeline and connected in series with each other, and the semiconductor refrigeration sheets generate electricity by utilizing the temperature difference between the upper and lower surfaces; The electricity generated by the semiconductor refrigeration chip is stored in a lithium-ion battery, and has a charge and discharge management circuit and a voltage conversion circuit, which can output 5V and 3.3V voltages at the same time to meet the power supply requirements of the entire monitoring device.

10. The high-temperature pipeline defect long-distance online monitoring device according to claim 1, characterized in that: The circuit board is encapsulated in an explosion-proof housing, and the circuit is connected to the ultrasonic waveguide probe via a wiring terminal.

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