In-service equipment monitoring sensor based on high-temperature demagnetization resistance, monitoring system and method

Abstract

The application discloses a kind of in-service equipment monitoring sensor based on high-temperature anti-demagnetization, monitoring system and method, sensor includes: shell, permanent magnet, shielding layer, coil, wear-resistant layer;Permanent magnet, including the magnetic body made of high-temperature-resistant permanent magnetic material, high-permeability alloy is coated on the outer periphery of the magnetic body, the diameter of the magnetic body decreases from top to bottom, and the high-permeability alloy is coated on the upper end surface and the circumferential surface of the magnetic body in several layers;The permanent magnet is reconstructed by the combination of the magnetic body and the high-permeability alloy, the high-permeability alloy is stacked and coated on the magnetic body, the permanent magnet and the detected object construct low-reluctance closed magnetic circuit to suppress the demagnetizing field strength, so that the working point of the sensor is stabilized in the reversible region of the hysteresis loop, and the magnetic property attenuation in high-temperature environment is effectively suppressed.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of electromagnetic ultrasonic nondestructive testing, and particularly relates to an in-service equipment monitoring sensor based on high-temperature demagnetization resistance, a monitoring system and a method. BACKGROUND

[0002] As a new type of nondestructive testing method, electromagnetic ultrasonic testing technology has the advantages of non-contact excitation, no need for coupling agent, and flexible excitation of various waveforms compared with traditional piezoelectric ultrasonic technology, and is particularly suitable for online monitoring of high-temperature and high-pressure equipment. Pressure-bearing equipment (such as pressure vessels and main steam pipelines) is long-term operated in an extreme environment of high temperature up to 350℃ and high pressure and irradiation, and is prone to composite failure modes such as irradiation embrittlement, stress corrosion cracking, and creep damage.

[0003] At present, nondestructive testing technologies for wall thickness defects of in-service equipment mainly include magnetic flux leakage detection, laser ultrasonic, piezoelectric ultrasonic, and electromagnetic ultrasonic methods. The magnetic flux leakage detection technology has the problem of insufficient measurement accuracy, and it is particularly difficult to detect large-area uniform corrosion thinning defects, which is easy to cause missed detection and misjudgment. The laser detection equipment has the disadvantages of large size and high cost, and its ablation effect may damage the pipe wall surface, so it is not suitable for long-term monitoring in a high-temperature sealed environment. The traditional piezoelectric ultrasonic detection technology needs a coupling agent, and it is difficult to realize long-term monitoring in a high-temperature environment. The existing technology is difficult to implement non-invasive monitoring of a pipeline with an insulating layer. The electromagnetic ultrasonic technology can directly excite ultrasonic waves on the pipe wall through the Lorentz force and magnetostrictive effect, without the need for a coupling agent, and has the advantages of high precision and non-contact, and is particularly suitable for long-term monitoring of high-temperature sealed pipelines. However, when the environmental temperature exceeds the Curie point of the magnet, demagnetization phenomenon occurs, resulting in a decrease in the transduction efficiency of the probe. Therefore, it has become a technical problem to be solved to develop an electromagnetic ultrasonic thickness measuring probe that can operate stably for a long time in a high-temperature environment, for long-term monitoring of high-temperature in-service equipment, while avoiding damage to the probe.

[0004] There are other related technologies in this field. For example, patent application CN111829466A discloses a high-temperature electromagnetic ultrasonic thickness measuring device, which integrates a circulating water cooling system, cooperates with an external water pump and a water storage tank to build a closed cooling loop, and can ensure that the probe works continuously and stably in a high-temperature environment. However, this design needs to configure a circulating pipeline and auxiliary equipment, resulting in a large overall structure, which has significant limitations in long-term online monitoring in densely packed pipeline areas or limited spaces.

[0005] In addition, the patent application with publication number CN222124276U proposes a high-temperature-resistant electromagnetic ultrasonic probe, which adopts a combination of heat pipes and heat sinks and is assisted by a fan cooling design to enhance the high-temperature stability of the electromagnetic coil and the permanent magnet. Although this technology improves the heat management capability through multi-stage heat dissipation design, the integration of the heat dissipation module and the air cooling device also leads to an excessively large probe size, and in a closed cavity or an industrial scene with complex structure, it still faces the dual challenges of insufficient space adaptability and reduced heat dissipation efficiency, making it difficult to meet the long-term monitoring needs in a high-temperature harsh environment in a narrow space.

[0006] The patent application with publication number CN111948587A uses temperature compensation materials to compensate for the deviation of the static magnetic field strength on the measured area caused by environmental temperature changes, so that the static main magnetic field strength has a lower temperature coefficient in the measured area, i.e., higher temperature stability. However, since it needs to add a temperature compensation block on one side of each magnetic block, it will cause uneven temperature distribution of the magnetic blocks, and still has the problem of magnetic field deviation, and the normal component magnetic flux density is not high enough.

[0007] The patent applications with publication numbers CN104880163A and CN102706966A both disclose technical solutions for using armature magnetic concentration, but there is still a problem of magnetic loss in the process of using armature magnetic concentration, and it cannot overcome the problem of high-temperature demagnetization. SUMMARY

[0008] The purpose of the present application is to provide a high-temperature anti-demagnetization in-service equipment monitoring sensor, which solves the problem of irreversible magnetic loss caused by the shift of the working point to the irreversible region of the hysteresis loop due to the demagnetizing field of the traditional EMAT permanent magnet at high temperature.

[0009] To solve the above technical problems, the present application adopts the following technical solution: a high-temperature anti-demagnetization in-service equipment monitoring sensor, which comprises:

[0010] a permanent magnet comprising a magnetic body made of high-temperature-resistant permanent magnetic material, a high-permeability alloy coated on the outer periphery of the magnetic body, the diameter of the magnetic body decreasing from top to bottom, and the high-permeability alloy having several layers and being coated on the upper end surface and the peripheral surface of the magnetic body layer by layer;

[0011] a shell made of high-temperature-resistant material, which is coated on the outer peripheral surface of the permanent magnet;

[0012] a shielding layer located below the magnetic body, and a sealing cover provided on the lower end of the shell;

[0013] a wear-resistant layer provided on the lower end of the shell and sealingly connected with the shell, the wear-resistant layer being located below the shielding layer and forming a gap between the shielding layer and the wear-resistant layer;

[0014] A coil made of high-temperature resistant wire is arranged in the gap between the shielding layer and the wear-resistant layer.

[0015] The permanent magnet and the object under inspection form a low-reluctance closed magnetic circuit to suppress the demagnetizing field strength, so that the working point of the sensor is stabilized in the reversible region of the hysteresis loop.

[0016] In another embodiment, the shell comprises an outer layer and an inner layer, and a heat insulation cavity is formed between the inner layer and the outer layer.

[0017] In another embodiment, the heat insulation cavity between the inner layer and the outer layer is filled with a heat insulation adhesive material.

[0018] In another embodiment, the inner side of the upper end of the inner layer is attached to the permanent magnet, and a gap is formed between the circumferential surface of the lower end of the inner layer and the permanent magnet, which is a heat insulation cavity.

[0019] In another embodiment, the magnetic body is made of samarium-cobalt magnet, alnico magnet, neodymium-iron-boron magnet or ferrite magnet.

[0020] In another embodiment, the high-permeability alloy is one or a combination of silicon steel sheet, soft magnetic ferrite, cobalt-based amorphous / nanocrystalline alloy, iron-based amorphous / nanocrystalline alloy, permalloy or high-permeability nickel-based alloy.

[0021] In another embodiment, the high-permeability alloy and the magnetic body, the high-permeability alloy and the high-permeability alloy are bonded by high-temperature resistant ceramic adhesive. The ceramic adhesive between the high-permeability alloy and the magnetic body, the high-permeability alloy and the high-permeability alloy, the shielding layer and the coil, the coil and the wear-resistant layer, the wear-resistant layer and the shell, and the shielding layer and the shell is subjected to secondary curing at high temperature to form a honeycomb microporous sealing structure.

[0022] In another embodiment, the magnetic body is an axially symmetric isosceles frustum, and the ratio of the diameter of the lower end surface to the height is 1:3-2:3, and the optimal ratio is 1:2.

[0023] The application also provides an in-service equipment monitoring system based on high-temperature anti-demagnetization, which comprises a host computer, a multi-channel monitoring host connected to the host computer, and a sensor connected to the multi-channel monitoring host, wherein the sensor is the above-mentioned sensor.

[0024] In another embodiment, the sensor further comprises a temperature sensor arranged on the shell, and the multi-channel monitoring host comprises a temperature compensation module for receiving temperature signals from the temperature sensor and adaptively correcting measurement results according to temperature changes to eliminate the influence of temperature.

[0025] In another implementation, the host computer comprises a feature parameter extraction and analysis module for extracting feature parameters representing the material state from the processed ultrasonic signals of the multi-channel monitoring host.

[0026] In another implementation, the wear-resistant layer is a high-temperature-resistant ceramic sheet with a thickness of 1.2-2.0 mm, and the surface is polished to a predetermined roughness to optimize the ultrasonic coupling effect.

[0027] In another implementation, the outer layer and the inner layer are both made of high-temperature-resistant stainless steel, and the shielding layer is made of a copper sheet with a thickness of 0.1-0.3 mm.

[0028] The present application also provides a monitoring method based on the above-mentioned system, which comprises the following steps:

[0029] Step S1: receiving the temperature signal from the temperature sensor and adaptively correcting the measurement result according to the temperature change, eliminating the temperature influence through the temperature compensation algorithm to obtain the compensated transverse and longitudinal wave speeds;

[0030] Step S2: based on the adjacent echo time difference Δt of the transverse wave signal and the compensated transverse wave speed Vs, and according to the amplitude attenuation and propagation time offset of each channel echo signal, the thickness value h = Δt·Vs / 2 is calculated based on the time difference diffraction method to evaluate the material corrosion;

[0031] Step S3: constructing a three-dimensional mesh model of the curved surface of the measured object, and expanding the discrete monitoring points into a continuous curved surface through the curvature integral interpolation algorithm, wherein the node interpolation weight is determined by the reciprocal of the curvature radius of the adjacent triangular facets;

[0032] Step S4: fusing the curved surface mesh model generated in step S3 with the corrosion defect feature data of step S2, representing the corrosion area of different depths through different gradient color mapping tables, and dynamically displaying the corrosion area ratio and the maximum corrosion depth;

[0033] Step S5: correcting the ultrasonic speed error under high temperature conditions by using the temperature compensation formula based on the transverse and longitudinal wave speed data excited by electromagnetic ultrasonic and the temperature compensation formula in step S1, and then calculating the Young's modulus through the feature parameter extraction and analysis algorithm to realize the continuous monitoring of the Young's modulus under high temperature environment.

[0034] The beneficial effects of the present application are that: when the working temperature approaches the Curie point of the permanent magnet, it is easy to enter the irreversible working area, unlike the conventional technology which delays the magnet approaching the Curie point through water circulation or air forced cooling temperature control means to ensure that it does not enter the irreversible area. The present application reconfigures the permanent magnet by combining the magnetic body with the high permeability alloy, the magnetic structure design of the magnetic body combined with the design of the heat insulation shell makes the permanent magnet and the detected object form a low magnetic resistance closed magnetic circuit to suppress demagnetization, when approaching the Curie point, relieve the magnetic performance decay, make the sensor working point stable in the reversible area of the hysteresis loop, to ensure that it does not enter the irreversible area, thereby effectively suppressing the magnetic performance decay under high temperature environment, effectively reducing the magnetic loss, solving the problem that the traditional EMAT (electromagnetic ultrasonic) permanent magnet under high temperature due to demagnetizing field makes the working point deviate to the irreversible area of the hysteresis loop and causes irreversible magnetic loss; The method discards the traditional complex external cooling system, fundamentally improves the high temperature stability of the permanent magnet through the anti-demagnetization innovation under high temperature, combines the multi-channel monitoring host, the temperature compensation module for eliminating temperature influence, the feature parameter extraction and analysis module to constitute a monitoring system to present the area ratio of corrosion defects and the maximum corrosion depth in real time, The in-service equipment monitoring system can realize the visualization mapping of the material corrosion defect distribution and the continuous monitoring of the material Young's modulus, effectively solve the long-existing technical bottlenecks of insufficient reliability and high maintenance cost in the field of high temperature equipment online monitoring, and provide a technical scheme for industrial equipment in-service detection. BRIEF DESCRIPTION OF DRAWINGS

[0035] Figure 1 It is the overall structure schematic diagram of the multi-channel monitoring system in embodiment one;

[0036] Figure 2 It is the hysteresis loop of the permanent magnet of the present application (the sensor working point in the figure is from b to c point, not including b point);

[0037] Figure 3 It is the overall structure schematic diagram of the electromagnetic ultrasonic transducer in embodiment one;

[0038] Figure 4 It is the overall structure schematic diagram of the electromagnetic ultrasonic transducer in embodiment two;

[0039] Figure 5 It is the overall structure schematic diagram of the multi-channel monitoring system in embodiment three;

[0040] Figure 6 It is the overall structure schematic diagram of the electromagnetic ultrasonic transducer in embodiment three. DETAILED DESCRIPTION

[0041] The formula of the demagnetization effect of the permanent magnet under high temperature environment is as follows;

[0042] The demagnetizing field expression is:

[0043]

[0044] Where H d is the demagnetization field, N is the demagnetization factor, and M is the magnetization intensity, where the demagnetization factor N is determined by the geometry of the magnet. At high temperatures, M decreases due to thermal disturbances, and H d Increases, pushing the working point to the irreversible region of the hysteresis loop, resulting in irreversible losses.

[0045] The construction of a closed magnetic circuit significantly reduces the magnetic resistance in the magnetic circuit. The magnetic resistance is defined as:

[0046]

[0047] Where l is the path length, A is the cross-sectional area, μ r is the relative magnetic permeability, μ0 is the vacuum magnetic permeability.

[0048] The total reluctance is given by:

[0049]

[0050] in: ,

[0051] Where R total is the total magnetic resistance, R main Main magnetic circuit, R leakage is the magnetic flux leakage path, R magnet is the magnetic reluctance of the magnet, R yoke The magnetic resistance of high permeability materials. Since high permeability components are much higher than air (μ r =1), the introduction of high permeability components makes R yoke Much smaller than R air , thereby significantly reducing the leakage flux and forcing the magnetic flux to be concentrated in the closed loop. According to Ohm's law of magnetic circuit, the total magnetic flux Φ total for:

[0052]

[0053] Where, Φ total is the total magnetic flux, Φ main Main magnetic flux, Φ leakage is the leakage flux.

[0054] According to the magnetic circuit shunt law, the ratio of the main magnetic flux to the leakage magnetic flux is:

[0055]

[0056] The demagnetizing field H generated by the leakage flux d for:

[0057]

[0058] Combining the magnetic circuit ohm law, total magnetic flux Φ total =F / R total (magnetic motive force F=H m L m , H m is the internal magnetic field of the permanent magnet), we get:

[0059]

[0060] The effective demagnetization factor is defined as:

[0061]

[0062] High temperature causes μ r(magnet) and μ r(yoke) to drop, but the high permeability material still satisfies μ r(yoke) much greater than 1, so that:

[0063]

[0064] At this time, the demagnetization factor is simplified as:

[0065]

[0066] In the formula, μ r(magnet) is the relative permeability of the magnet and μ r(yoke) is the relative permeability of the high permeability material. Through the high temperature resistant high permeability alloy material with μ r(yoke) much greater than 1, the effective demagnetization factor tends to zero, thereby suppressing the demagnetization field strength, stabilizing the sensor operating point in the reversible region of the hysteresis loop, as shown in Figure 2 , effectively suppressing the magnetic property attenuation in high temperature environment and improving the sensor transduction efficiency in high temperature.

[0067] The application will be described in detail below in combination with the embodiments shown in the drawings.

[0068] Example one, as shown in Figure 1 , the high temperature anti-demagnetization in-service equipment monitoring system includes: host computer 11, multi-channel monitoring host 9 connected with the host computer, high temperature anti-demagnetization in-service equipment monitoring sensor 8 connected with the multi-channel monitoring host 9. As shown in Figure 3 , the high temperature anti-demagnetization in-service equipment monitoring sensor includes: permanent magnet, shell 4, shielding layer 6, wear-resistant layer 5, coil 3, temperature sensor 7.

[0069] Specifically, the permanent magnet comprises a magnetic body 1 made of high-temperature-resistant permanent magnet material, and a high-permeability alloy 2 coated on the outer periphery of the magnetic body 1. The diameter of the magnetic body 1 decreases from top to bottom, and the magnetic concentration effect is better, which improves the anti-demagnetization ability of the magnetic body 1. The high-permeability alloy 2 has several layers and is coated on the upper end surface and the peripheral surface of the magnetic body 1 layer by layer. The permanent magnet and the detected object 10 construct a low-magnetic-resistance closed magnetic circuit to suppress the demagnetizing field strength, so that the working point of the sensor is stabilized in the reversible region of the magnetic hysteresis loop. The magnetic body 1 is made of samarium-cobalt magnet, aluminum-nickel-cobalt magnet, neodymium-iron-boron magnet or ferrite magnet, and the best one is samarium-cobalt magnet. The magnetic body 1 is in the shape of an axially symmetric isosceles truncated cone, and the ratio of the diameter of the lower end surface to the height is 1:3-2:3, and the best ratio is 1:2. The high-permeability alloy 2 is one or a combination of silicon steel sheet, soft magnetic ferrite, cobalt-based amorphous / nanocrystalline alloy, iron-based amorphous / nanocrystalline alloy, permalloy or high-permeability nickel-based alloy, and the best one is silicon steel sheet.

[0070] The shell 4 is made of high-temperature-resistant material and is coated on the outer periphery of the permanent magnet. The shell comprises a shell mounting seat 46, an outer layer 41 mounted on the shell mounting seat 46 and an inner layer 42. A heat insulation cavity is formed between the inner layer 42 and the outer layer 41. Both the outer layer 41 and the inner layer 42 are made of high-temperature-resistant stainless steel, and the heat insulation cavity between the inner layer 42 and the outer layer 41 is filled with heat insulation glue material 40. The inner side of the upper end of the inner layer 42 is attached to the permanent magnet, and the peripheral surface of the lower end of the inner layer 42 forms a gap with the permanent magnet, which is a heat insulation cavity 43, and the heat insulation cavity 43 is also filled with heat insulation glue material 40. The temperature sensor 7 is arranged on the outer side wall of the outer layer 41. The first signal line 71 for transmitting the temperature signal of the temperature sensor 7 is attached to the outer side wall of the outer layer 41 and extends upward into the shell mounting seat 46, and then extends out of the peripheral surface of the shell mounting seat 46 and is electrically connected to the multi-channel monitoring host 9.

[0071] The shielding layer 6 is located below the magnetic body 1, and the middle part of the upper end surface of the shielding layer 6 is attached to the lower end surface of the magnetic body 1, and a sealing cover of the shielding layer 6 is arranged on the lower end of the shell 4. The wear-resistant layer 5 is arranged on the lower end of the shell 4 and is sealingly connected to the shell 4. The wear-resistant layer 5 is located below the shielding layer 6 and forms a gap with the shielding layer 6. The coil 3 is made of high-temperature-resistant wire and is arranged in the gap between the shielding layer 6 and the wear-resistant layer 5. The inner part of the shell 4 is provided with a channel 48 for arranging the signal line. The channel 48 extends horizontally from the peripheral surface of the shell mounting seat 46, then extends vertically to the inner layer 42, and finally extends to the area where the coil 3 is located by penetrating the shielding layer 6. The second signal line 31 for transmitting the signal of the coil 3 penetrates the channel 48 and is connected to the multi-channel monitoring host 9. The first signal line 71 and the second signal line 31 are provided with a protective sleeve 49 supported by asbestos at the leading-out part of the shell mounting seat 46. The shielding layer 6 is made of copper sheet with a thickness of 0.1-0.3 mm. The wear-resistant layer 5 is a high-temperature-resistant ceramic sheet with a thickness of 1.2-2.0 mm, and the surface is polished to a predetermined roughness to optimize the ultrasonic coupling effect.

[0072] The high permeability alloy 2 and the magnetic body 1, the high permeability alloy 2 and the high permeability alloy 2 are bonded by the high-temperature-resistant ceramic adhesive; the ceramic adhesive between the high permeability alloy 2 and the magnetic body 1, the high permeability alloy 2 and the high permeability alloy 2, the shielding layer 6 and the coil 3, the coil 3 and the wear-resistant layer 5, the wear-resistant layer 5 and the shell 4, and the shielding layer 6 and the shell 4 are subjected to secondary curing at high temperature to form a honeycomb micropore sealing structure, which can enhance the heat insulation effect between the permanent magnet and the high-temperature environment.

[0073] The multi-channel monitoring host 9 comprises a temperature compensation module for receiving a temperature signal from the temperature sensor 7 and adaptively correcting the measurement result according to the temperature change and eliminating the temperature influence, and the temperature compensation module is configured with an adaptive temperature compensation algorithm;

[0074] The adaptive temperature compensation algorithm determines the transverse wave speed V s0 and the preset value (the longitudinal and transverse wave speeds at 25℃) of the longitudinal wave speed V p0 based on the material properties of the measured member (taking 20# steel as an example), and uses the temperature monitoring sensor to obtain real-time temperature data, and then completes the speed correction at different temperatures through a compensation coefficient, as follows:

[0075]

[0076] In the formula, f1(T) is the compensation coefficient of the temperature on the transverse wave speed, f2(T) is the compensation coefficient of the temperature on the longitudinal wave speed, T is the actual environmental temperature, V' is the longitudinal and transverse wave speed at different temperatures, and V0 is the transverse and longitudinal wave speed at 25℃.

[0077] The compensation coefficient is obtained by measuring the ultrasonic wave speed values at multiple temperature points to obtain a series of data (T, V), and the least square method is used to fit the corresponding relationship formula of the transverse and longitudinal wave speeds and the temperature under high temperature conditions.

[0078] Based on the adjacent echo time difference Δt of the transverse wave signal and the compensated transverse wave speed V s , the thickness of the measured member is calculated by h=Δt·V s / 2 to evaluate the corrosion defects, a curved surface grid model of the measured member is constructed, the two-dimensional display of the corrosion of the measured member is realized by the curvature integral interpolation algorithm combined with the monitoring data of each channel, and the material corrosion defect distribution is displayed in the interface by gradient color scale mapping.

[0079] The host computer 11 comprises a characteristic parameter extraction and analysis module for analyzing the characteristic parameters representing the material state from the ultrasonic signals processed by the multi-channel monitoring host 9;

[0080] The characteristic parameter extraction and analysis algorithm is used for correcting the ultrasonic wave speed error under the high temperature condition by using the temperature compensation formula to modify the transverse wave and longitudinal wave speed data excited by the EMAT, and finally calculating the Young's modulus to realize the continuous monitoring of the Young's modulus under the high temperature environment.

[0081]

[0082] In the formula, E is the Young's modulus of the material, rho is the density of the material, V p is the longitudinal wave propagation speed, V s is the transverse wave propagation speed.

[0083] The application also provides a monitoring method based on the above system, which comprises the following steps:

[0084] Step S1: receiving the temperature signal from the temperature sensor 7, and adaptively correcting the measurement result according to the temperature change, eliminating the temperature influence through the temperature compensation algorithm, and obtaining the compensated transverse wave and longitudinal wave speed;

[0085] Step S2: based on the adjacent echo time difference Delta t of the transverse wave signal and the compensated transverse wave speed V s , and then based on the time difference diffraction method, the thickness value h = Delta t V s / 2 is calculated according to the echo signal amplitude attenuation and propagation time offset of each channel to evaluate the material corrosion;

[0086] Step S3: constructing the three-dimensional grid model of the curved surface of the measured piece, and expanding the discrete monitoring points into a continuous curved surface through the curvature integral interpolation algorithm, wherein the node interpolation weight is determined by the reciprocal of the curvature radius of the adjacent triangular facets;

[0087] Step S4: fusing the curved surface grid model generated in step S3 with the corrosion defect characteristic data in step S2, representing the corrosion area of different depths through different gradient color mapping tables, and dynamically displaying the corrosion area ratio and the maximum corrosion depth;

[0088] Step S5: modifying the ultrasonic wave speed error under the high temperature condition by using the temperature compensation formula based on the transverse wave and longitudinal wave speed data excited by the electromagnetic ultrasonic wave and based on step S1, and then calculating the Young's modulus through the characteristic parameter extraction and analysis algorithm to realize the continuous monitoring of the Young's modulus under the high temperature environment.

[0089] Embodiment two, the in-service equipment monitoring system based on high-temperature anti-demagnetization comprises a host computer 11, a multi-channel monitoring host computer 9 connected with the host computer, and an in-service equipment monitoring sensor based on high-temperature anti-demagnetization connected with the multi-channel monitoring host computer 9. Figure 4 As shown in the figure, the in-service equipment monitoring sensor based on high-temperature anti-demagnetization comprises a permanent magnet, a shell 4, a shielding layer 6, a wear-resistant layer 5, a coil 3 and a temperature sensor 7.

[0090] Specifically, the permanent magnet comprises a magnetic body 1 made of high-temperature-resistant permanent magnet material, and a high-permeability alloy 2 coated on the outer periphery of the magnetic body 1. The diameter of the magnetic body 1 decreases from top to bottom, and the high-permeability alloy 2 is coated on the upper end surface and the peripheral surface of the magnetic body 1 in several layers. The permanent magnet and the object 10 under inspection form a low-magnetic-resistance closed magnetic circuit to suppress the demagnetizing field strength, so that the working point of the sensor is stabilized in the reversible region of the hysteresis loop. The magnetic body 1 is made of samarium-cobalt magnet, aluminum-nickel-cobalt magnet, neodymium-iron-boron magnet, or ferrite magnet, and is preferably made of samarium-cobalt magnet. The magnetic body is an axially symmetric isosceles truncated cone, and the ratio of the diameter of the lower end surface to the height is 1:3-2:3, and is preferably 1:2. The high-permeability alloy 2 is one or a combination of silicon steel sheet, soft magnetic ferrite, cobalt-based amorphous / nanocrystalline alloy, iron-based amorphous / nanocrystalline alloy, permalloy, or high-permeability nickel-based alloy, and is preferably a silicon steel sheet.

[0091] The shell 4 is made of high-temperature-resistant material and is coated on the outer periphery of the permanent magnet. The shell comprises a shell mounting seat 46, an outer layer 41 mounted on the shell mounting seat 46, and an inner layer 42. A heat insulation cavity is formed between the inner layer 42 and the outer layer 41. Both the inner layer 42 and the outer layer 41 are made of high-temperature-resistant stainless steel, and the heat insulation cavity between the inner layer 42 and the outer layer 41 is filled with heat insulation glue material 40. The inner side of the upper end of the inner layer 42 is attached to the permanent magnet, and a gap is formed between the peripheral surface of the lower end of the inner layer 42 and the permanent magnet. The gap is a heat insulation cavity 43, which is also filled with heat insulation glue material 40. The temperature sensor 7 is arranged in the heat insulation cavity between the inner layer 42 and the outer layer 41. The first signal line 71 for transmitting the temperature signal of the temperature sensor 7 is arranged in the heat insulation cavity between the inner layer 42 and the outer layer 41, and extends out of the peripheral surface of the shell mounting seat 46 and is electrically connected to the multi-channel monitoring host 9.

[0092] The middle part of the upper end surface of the shielding layer 6 is attached to the lower end surface of the magnetic body 1, and a sealing cover is arranged on the lower end of the shell 4; the wear-resistant layer 5 is arranged on the lower end of the shell 4 and is sealingly connected with the shell 4, the wear-resistant layer 5 is located below the shielding layer 6 and forms a gap between the shielding layer 6, the lower end surface of the temperature sensor 7 is flush with the lower end surface of the wear-resistant layer 5, and the temperature sensor 7 can be attached to the surface of the detected object 10 during detection, so that the temperature sensor 7 can accurately detect the temperature of the detected object 10, and the temperature sensor 7 and the first signal line 71 thereof can be sealed in the heat insulation glue material 40 and located between the outer layer 41 and the inner layer 42 of the high-temperature-resistant stainless steel, thereby comprehensively protecting the temperature sensor 7; the coil 3 is made of high-temperature-resistant wire and is arranged in the gap between the shielding layer 6 and the wear-resistant layer 5, a channel 48 for arranging the signal line is arranged in the shell 4, the channel 48 extends horizontally from the surface of the shell mounting seat 46, then extends vertically to the inner layer 42, and finally extends through the shielding layer 6 to the area where the coil 3 is located, the second signal line 31 for transmitting signals on the coil 3 passes through the channel 48 and is connected to the multi-channel monitoring host 9, and the first signal line 71 and the second signal line 31 are provided with a protective sleeve 49 supported by asbestos at the leading-out position of the shell mounting seat 46; the shielding layer 6 is made of a copper sheet with a thickness of 0.1-0.3 mm. The wear-resistant layer 5 is a high-temperature-resistant ceramic sheet with a thickness of 1.2-2.0 mm, and the surface is polished to a predetermined roughness to optimize the ultrasonic coupling effect.

[0093] The high-permeability alloy 2 and the magnetic body 1, the high-permeability alloy 2 and the high-permeability alloy 2, the shielding layer 6 and the coil 3, the coil 3 and the wear-resistant layer 5, the wear-resistant layer 5 and the shell 4, and the shielding layer 6 and the shell 4 are bonded by high-temperature-resistant ceramic adhesive; the high-temperature-resistant ceramic adhesive between the high-permeability alloy 2 and the magnetic body 1, the high-permeability alloy 2 and the high-permeability alloy 2, the shielding layer 6 and the coil 3, the coil 3 and the wear-resistant layer 5, the wear-resistant layer 5 and the shell 4, and the shielding layer 6 and the shell 4 is secondary cured at high temperature to form a honeycomb microporous sealing structure, which can enhance the heat insulation effect between the permanent magnet and the high-temperature environment.

[0094] The multi-channel monitoring host 9 comprises a temperature compensation module for receiving temperature signals from the temperature sensor 7 and adaptively correcting measurement results according to temperature changes to eliminate the influence of temperature; the temperature compensation module is configured with an adaptive temperature compensation algorithm.

[0095] The adaptive temperature compensation algorithm determines the transverse wave speed V s0 and the preset value (the longitudinal and transverse wave speeds at 25℃) of the longitudinal wave speed V p0 based on the material properties of the measured object (taking 20# steel as an example), and uses a temperature monitoring sensor to obtain temperature data in real time, and then completes the speed correction at different temperatures through a compensation coefficient, as follows:

[0096]

[0097] In the formula, f1(T) is a compensation coefficient of temperature on the transverse wave speed, f2(T) is a compensation coefficient of temperature on the longitudinal wave speed, T is the actual ambient temperature, V' is the longitudinal and transverse wave speed at different temperatures, and V0 is the transverse and longitudinal wave speed at 25 DEG C.

[0098] The compensation coefficient is obtained by measuring the ultrasonic wave speed values at multiple temperature points to obtain a series of data (T, V), and a least square method is used to fit the corresponding relationship formula of the transverse and longitudinal wave speed and the temperature under high temperature conditions.

[0099] The thickness of the measured member is calculated by h = Δt V s / 2 based on the adjacent echo time difference Δt of the transverse wave signal and the compensated transverse wave speed V s , and the corrosion defect of the material is evaluated.

[0100] The host computer 11 comprises a characteristic parameter extraction and analysis module for extracting and analyzing the characteristic parameters representing the material state from the ultrasonic signals processed by the multi-channel monitoring host computer 9;

[0101] The characteristic parameter extraction and analysis algorithm is used to correct the ultrasonic wave speed error under high temperature conditions by using the transverse and longitudinal wave speed data excited by the EMAT and using the temperature compensation formula, and finally the Young's modulus is calculated to realize the continuous monitoring of the Young's modulus under high temperature conditions.

[0102]

[0103] In the formula, E is the Young's modulus of the material, ρ is the density of the material, V p is the longitudinal wave propagation speed, and V s is the transverse wave propagation speed.

[0104] The application also provides a monitoring method based on the above-mentioned system, which comprises the following steps:

[0105] Step S1: receiving the temperature signal from the temperature sensor 7, and adaptively correcting the measurement result according to the temperature change, eliminating the temperature influence by the temperature compensation algorithm, and obtaining the compensated longitudinal and transverse wave speeds;

[0106] Step S2: based on the adjacent echo time difference Δt of the transverse wave signal and the compensated transverse wave speed V s , and then evaluating the material corrosion based on the time difference diffraction method according to the echo signal amplitude attenuation and the propagation time offset of each channel, and calculating the thickness value h = Δt V s / 2.

[0107] Step S3: constructing a three-dimensional mesh model of the surface of the test piece, and expanding the discrete monitoring points into a continuous surface through a curvature integral interpolation algorithm, wherein the node interpolation weight is determined by the inverse of the curvature radius of adjacent triangles;

[0108] Step S4: Fusing the surface mesh model generated in step S3 with the corrosion defect feature data in step S2, characterizing corrosion areas of different depths through different gradient color mapping, and dynamically displaying the corrosion area ratio and maximum corrosion depth;

[0109] Step S5: The transverse wave and longitudinal wave speed data excited by electromagnetic ultrasound are used to correct the ultrasonic speed error under high temperature conditions using the temperature compensation formula based on step S1, and then the Young's modulus is calculated through characteristic parameter extraction and analytical algorithm to achieve continuous monitoring of the Young's modulus under high temperature environment.

[0110] Example 3, as Figure 5 As shown, the high temperature anti-demagnetization in-service equipment monitoring system includes: a host computer 11, a multi-channel monitoring host 9 connected to the host computer, a high temperature anti-demagnetization in-service equipment monitoring sensor 8 connected to the multi-channel monitoring host 9, an air pump 410, and an air source 411. Figure 6 As shown, the in-service equipment monitoring sensor based on high-temperature anti-demagnetization includes: a permanent magnet, a shell 4, a shielding layer 6, a wear-resistant layer 5, a coil 3, and a temperature sensor 7.

[0111] Specifically, the permanent magnet comprises a magnetic body 1 made of a high-temperature resistant permanent magnetic material and a high-permeability alloy 2 coated around the outer periphery of the magnetic body 1. The diameter of the magnetic body 1 decreases from top to bottom, and the high-permeability alloy 2 is layered and coated on the upper end surface and circumference of the magnetic body 1. The permanent magnet and the object under test 10 form a low-reluctance closed magnetic circuit to suppress the demagnetization field strength, stabilizing the operating point within the reversible region of the hysteresis loop. The magnetic body 1 is made of samarium cobalt, alnico, neodymium iron boron, or ferrite magnets, with samarium cobalt being the most preferred. The magnetic body is shaped like an axially symmetric isosceles frustum, with the ratio of its lower end diameter to its height being between 1:3 and 2:3, with a ratio of 1:2 being the most preferred. This shape provides the best balance between magnetic field strength and magnetic concentration, which helps stabilize the sensor's operating point within the reversible region of the hysteresis loop. The high permeability alloy 2 is a combination of one or more of silicon steel sheet, soft ferrite, cobalt-based amorphous / nanocrystalline alloy, iron-based amorphous / nanocrystalline alloy, Permalloy or high permeability nickel-based alloy, preferably silicon steel sheet.

[0112] The shell 4 is made of high-temperature resistant material, which is coated on the outer circumferential surface of the permanent magnet; the shell comprises a shell mounting seat 46, an outer layer 41 mounted on the shell mounting seat 46 and an inner layer 42, and a heat insulation cavity is formed between the inner layer 42 and the outer layer 41. The outer layer 41 and the inner layer 42 are both made of high-temperature resistant stainless steel, and the heat insulation cavity between the inner layer 42 and the outer layer 41 is filled with heat insulation glue material 40. The inner side of the upper end of the inner layer 42 is attached to the permanent magnet, and the inner layer 42 can be axially spliced to form a cover plate and a cylindrical main body, so that the permanent magnet can be fixed by penetrating the main body and buckling the cover plate, and a gap is formed between the lower end of the inner layer 42 and the outer circumferential surface of the permanent magnet, which is a heat insulation cavity 43. The temperature sensor 7 is arranged in the heat insulation cavity between the inner layer 42 and the outer layer 41, and the first signal line 71 for transmitting the temperature signal of the temperature sensor 7 is arranged in the heat insulation cavity between the inner layer 42 and the outer layer 41 and extends out of the circumferential surface of the shell mounting seat 46 to be electrically connected with the multi-channel monitoring host 9.

[0113] The middle part of the upper end face of the shielding layer 6 is attached to the lower end face of the magnetic body 1, and a sealing cover is arranged on the lower end part of the shell 4; the wear-resistant layer 5 is arranged on the lower end part of the shell 4 and is sealingly connected with the shell 4, the wear-resistant layer 5 is located below the shielding layer 6 and a gap is formed between the wear-resistant layer 5 and the shielding layer 6, the lower end face of the temperature sensor 7 is flush with the lower end face of the wear-resistant layer 5, and the temperature sensor 7 can be attached to the surface of the detected object 10 during detection, so that the temperature sensor 7 can accurately detect the temperature of the detected object 10, and the temperature sensor 7 and the first signal line 71 are sealed in the heat insulation glue material 40 and located between the outer layer 41 and the inner layer 42 of the high-temperature-resistant stainless steel, thereby comprehensively protecting the temperature sensor 7; the coil 3 is made of high-temperature-resistant wire and is arranged in the gap between the shielding layer 6 and the wear-resistant layer 5, a channel 48 for arranging signal lines is formed in the inside of the shell 4, the channel 48 extends horizontally from the periphery of the shell mounting seat 46, then extends vertically to the inner layer 42, and finally extends through the shielding layer 6 to the area where the coil 3 is located, the second signal line 31 for transmitting signals on the coil 3 passes through the channel 48 and is connected to the multi-channel monitoring host 9, a branch channel 47 connected to the heat insulation cavity 43 is arranged on the channel 48, an electromagnetic valve 44 is arranged on the branch channel, a gas conveying pipe 412 connected to the channel 48 is arranged on the leading-out outlet of the channel 48, the gas conveying pipe 412 is connected to a gas source 411 and a gas pump 410, and the heat insulation cavity 43 is vacuumized or filled with heat insulation gas argon provided by the gas source 411 to realize various heat insulation modes, thereby further improving the anti-demagnetization capability of the sensor 8, the channel 48 can be used for wiring and can also switch the heat insulation mode of the heat insulation cavity 43, the heat insulation mode can be filling argon in the heat insulation cavity 43 to realize heat insulation or extracting argon in the heat insulation cavity 43 to realize vacuum heat insulation, and when the temperature of the detected object 10 is higher than the normal detection temperature, the argon filling heat insulation and the vacuum heat insulation can be alternately used to further improve the anti-demagnetization capability of the permanent magnet, the first signal line 71 and the second signal line 31 are provided with a protective sleeve 49 supported by asbestos at the leading-out position of the shell mounting seat 46, and the first signal line 71 and the second signal line 31 pass out of the gas conveying pipe 412 after being led out of the high-temperature area and are sealingly connected with the gas conveying pipe 412, the gas conveying pipe 412 not only conveys gas but also protects the first signal line 71 and the second signal line 31; the shielding layer 6 is made of a copper sheet with a thickness of 0.1-0.3 mm, the wear-resistant layer 5 is a high-temperature-resistant ceramic sheet with a thickness of 1.2-2.0 mm, and the surface is polished to a predetermined roughness to optimize the ultrasonic coupling effect.

[0114] The high permeability alloy 2 and the magnetic body 1, the high permeability alloy 2 and the high permeability alloy 2 are bonded by the high-temperature-resistant ceramic adhesive; the ceramic adhesive between the high permeability alloy 2 and the magnetic body 1, the high permeability alloy 2 and the high permeability alloy 2, the shielding layer 6 and the coil 3, the coil 3 and the wear-resistant layer 5, the wear-resistant layer 5 and the shell 4, and the shielding layer 6 and the shell 4 are subjected to secondary curing at high temperature to form a honeycomb micropore sealing structure, which can enhance the heat insulation effect between the permanent magnet and the high-temperature environment.

[0115] The multi-channel monitoring host 9 comprises a temperature compensation module for receiving temperature signals from the temperature sensor 7 and adaptively correcting measurement results according to temperature changes and eliminating temperature effects, and the temperature compensation module is configured with an adaptive temperature compensation algorithm;

[0116] The adaptive temperature compensation algorithm determines the transverse wave speed V s0 and the preset value of the longitudinal wave speed V p0 of the measured object (taking 20# steel as an example) based on the material properties of the measured object, and uses the temperature monitoring sensor to obtain real-time temperature data, and then uses a compensation coefficient to correct the speed at different temperatures, as follows:

[0117]

[0118] In the formula, f1(T) is the compensation coefficient of the temperature on the transverse wave speed, f2(T) is the compensation coefficient of the temperature on the longitudinal wave speed, T is the actual environmental temperature, V' is the longitudinal and transverse wave speed at different temperatures, and V0 is the transverse and longitudinal wave speed at 25 DEG C.

[0119] The compensation coefficient is obtained by measuring the ultrasonic wave speed values at multiple temperature points to obtain a series of data (T, V), and the least square method is used to fit the corresponding relationship formula of the transverse and longitudinal wave speeds and the temperature under high temperature conditions.

[0120] Based on the time difference Δt of the adjacent echoes of the transverse wave signal and the compensated transverse wave speed V s , the thickness of the measured object is calculated by h=Δt·V s / 2 to evaluate the corrosion defects, a curved surface grid model of the measured object is constructed, the two-dimensional display of the corrosion of the measured object is realized by the curvature integral interpolation algorithm combined with the monitoring data of each channel, and the material corrosion defect distribution is displayed in the interface by gradient color scale mapping.

[0121] The host computer 11 comprises a characteristic parameter extraction and analysis module for analyzing the characteristic parameters representing the material state from the ultrasonic signals processed by the multi-channel monitoring host 9;

[0122] The characteristic parameter extraction and analysis algorithm is used for the transverse wave and longitudinal wave sound velocity data excited by the EMAT, and the temperature compensation formula is used to correct the ultrasonic sound velocity error under high temperature conditions, and finally the Young's modulus is calculated to realize the continuous monitoring of the Young's modulus under high temperature environment, and the specific calculation formula is as follows:

[0123]

[0124] In the formula, E is the Young's modulus of the material, p is the density of the material, V p is the longitudinal wave propagation speed, V s is the transverse wave propagation speed.

[0125] The application also provides a monitoring method based on the above-mentioned system, which comprises the following steps:

[0126] Step S1: receiving the temperature signal from the temperature sensor 7, and adaptively correcting the measurement result according to the temperature change, eliminating the temperature influence through the temperature compensation algorithm, and obtaining the compensated transverse and longitudinal wave sound velocities;

[0127] Step S2: based on the adjacent echo time difference Δt of the transverse wave signal and the compensated transverse wave sound velocity V s , and then according to the amplitude attenuation and propagation time offset of each channel echo signal, the thickness value h=Δt·V s / 2 is calculated based on the time difference diffraction method to evaluate the material corrosion;

[0128] Step S3: constructing a three-dimensional grid model of the curved surface of the measured piece, and expanding the discrete monitoring points into a continuous curved surface through the curvature integral interpolation algorithm, wherein the node interpolation weight is determined by the reciprocal of the curvature radius of the adjacent triangular facets;

[0129] Step S4: fusing the curved surface grid model generated in step S3 with the corrosion defect characteristic data of step S2, representing the corrosion areas of different depths through different gradient color mapping tables, and dynamically displaying the corrosion area ratio and the maximum corrosion depth;

[0130] Step S5: through the transverse wave and longitudinal wave sound velocity data excited by the electromagnetic ultrasonic, and based on step S1, the temperature compensation formula is used to correct the ultrasonic sound velocity error under high temperature conditions, and then the characteristic parameter extraction and analysis algorithm is used to calculate the Young's modulus, realizing the continuous monitoring of the Young's modulus under high temperature environment;

[0131] When the temperature of the detected object 10 is higher than the normal detection temperature, the argon filling heat insulation and vacuum heat insulation can be alternately used in step S1, so as to further improve the anti-demagnetization ability of the permanent magnet.

[0132] The above examples are only for illustrating the technical concept and characteristics of the present application, and the purpose is to enable those skilled in the art to understand the content of the present application and to implement it, and cannot limit the protection scope of the present application. Any equivalent changes or modifications made according to the spirit of the present application should be covered within the protection scope of the present application.

Claims

1. A high-temperature anti-demagnetization in-service equipment monitoring sensor, characterized in that: It includes: A permanent magnet, comprising a magnetic body (1) made of a high-temperature resistant permanent magnetic material, and a high-permeability alloy (2) coated on the outer periphery of the magnetic body (1), wherein the diameter of the magnetic body (1) decreases from top to bottom, the magnetic body (1) is in the shape of an axially symmetrical isosceles frustum, and the ratio of the diameter of its lower end face to its height is 1:2, and the high-permeability alloy (2) has several layers and is coated on the upper end face and the peripheral surface of the magnetic body (1) layer by layer; A shell (4) is made of a high-temperature resistant material and is coated on the outer peripheral surface of the permanent magnet; a shielding layer (6) located below the magnetic body (1), and a sealing cover thereof provided on the lower end portion of the housing (4); a wear-resistant layer (5), which is provided at the lower end of the shell (4) and is sealed to the shell (4); the wear-resistant layer (5) is located below the shielding layer (6) and forms a gap with the shielding layer (6); A coil (3) made of a high-temperature resistant wire and arranged in a gap between the shielding layer (6) and the wear-resistant layer (5); The permanent magnet and the object to be detected (10) form a low magnetic resistance closed magnetic circuit to suppress the demagnetization field strength, so that the working point of the sensor (8) is stabilized in the reversible region of the hysteresis loop; The shell comprises a shell mounting seat (46), an outer layer (41) mounted on the shell mounting seat (46), and an inner layer (42), wherein the inner side of the upper end of the inner layer (42) is in contact with the permanent magnet, and a gap is formed between the peripheral surface of the lower end and the permanent magnet, and the gap is a heat-insulating cavity (43); The shell (4) is provided with a channel (48) for arranging a signal line. The second signal line (31) for transmitting a signal on the coil passes through the channel (48) and is connected to the multi-channel monitoring host. The channel (48) is provided with a branch channel (47) connected to the thermal insulation cavity (43). The branch channel (47) is provided with a solenoid valve (44). The channel (48) is provided with a gas pipe (412) connected to the channel (48) at the outlet of the shell mounting seat (46). The gas pipe (412) is connected to the gas source (411) and is used to evacuate the thermal insulation cavity (43) or introduce the thermal insulation gas argon provided by the gas source (411) into the thermal insulation cavity (43) through the air pump (410) to achieve various forms of thermal insulation.

2. The high-temperature anti-demagnetization in-service equipment monitoring sensor according to claim 1, characterized in that: A heat-insulating cavity is formed between the inner layer (42) and the outer layer (41).

3. The high-temperature anti-demagnetization in-service equipment monitoring sensor according to claim 2, characterized in that: The heat-insulating cavity between the inner layer (42) and the outer layer (41) is filled with a heat-insulating adhesive material (40).

4. The high-temperature anti-demagnetization in-service equipment monitoring sensor according to claim 1, characterized in that: The magnetic body (1) is made of a samarium cobalt magnet, an aluminum nickel cobalt magnet, a neodymium iron boron magnet or a ferrite magnet.

5. The high-temperature anti-demagnetization in-service equipment monitoring sensor according to claim 1, characterized in that: The high magnetic permeability alloy (2) is a combination of one or more of silicon steel sheets, soft magnetic ferrite, cobalt-based amorphous / nanocrystalline alloy, iron-based amorphous / nanocrystalline alloy, Permalloy or high magnetic permeability nickel-based alloy.

6. The high-temperature anti-demagnetization in-service equipment monitoring sensor according to claim 1, characterized in that: The high magnetic permeability alloy (2) and the magnetic body (1), and the high magnetic permeability alloy (2) and the high magnetic permeability alloy (2) are bonded together by a high-temperature resistant ceramic adhesive.

7. A high-temperature anti-demagnetization in-service equipment monitoring system, comprising: A host computer (11), a multi-channel monitoring host (9) connected to the host computer, and a sensor connected to the multi-channel monitoring host (9), wherein the sensor is any one of the sensors in claims 1-6.

8. The monitoring system according to claim 7, characterized in that: The sensor further comprises a temperature sensor (7) provided on the housing (4), and the multi-channel monitoring host (9) comprises a temperature supplement module for receiving a temperature signal from the temperature sensor (7), adaptively correcting a measurement result according to temperature changes, and eliminating temperature influences.

9. The monitoring system according to claim 8, characterized in that: The host computer (11) includes a characteristic parameter extraction and analysis module for analyzing characteristic parameters representing the material state from the ultrasonic signal processed by the multi-channel monitoring host (9).

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