A hydrogen embrittlement cracking early warning method and system for hydrogen storage tanks based on acoustic emission technology

Abstract

The present invention discloses a hydrogen storage tank hydrogen embrittlement cracking early warning method and system based on acoustic emission technology, the method comprising: arranging an acoustic emission sensor on the hydrogen storage tank to be monitored, collecting the acoustic emission signal generated by the entire process of hydrogen embrittlement cracking of the hydrogen storage tank to be monitored in real time through the acoustic emission sensor; calculating the stress intensity factor based on the collected acoustic emission signal; based on the calculated stress intensity factor, judging the danger level of the hydrogen storage tank crack in real time according to the preset danger level judgment criteria, and performing graded early warning of the hydrogen storage tank hydrogen embrittlement cracking process according to the danger level. The present invention can sensitively monitor the microcracks caused by hydrogen corrosion in the hydrogen storage tank, realize timely early warning of early defects of the hydrogen storage tank, and lay a foundation for early prevention of hydrogen storage safety accidents.

Description

Technical Field

[0001] The present invention relates to the technical field of hydrogen storage tank hydrogen embrittlement cracking monitoring and early warning, and in particular to a hydrogen storage tank hydrogen embrittlement cracking early warning method and system based on acoustic emission technology. Background Art

[0002] Hydrogen storage tanks are key equipment in the hydrogen production, storage, and refueling processes. With the rapid development of the hydrogen energy industry, the safety monitoring and assessment technology for hydrogen storage tanks has been continuously improved. Among them, defect damage monitoring is an important method for evaluating the safety performance of hydrogen storage tanks, calculating the remaining life, and preventing leakage accidents. At present, high-pressure gaseous hydrogen storage is the most common method of hydrogen storage. Since there is no material that can completely block the effect of hydrogen embrittlement, under this hydrogen storage condition, the hydrogen storage tank is not only damaged by long-term pressure on the inner surface and fatigue damage caused by repeated filling and degassing, but also by stress concentration caused by hydrogen embrittlement.

[0003] Traditional safety performance evaluation of hydrogen storage tanks is mainly based on fatigue damage of materials under service loads. It fails to establish a defect damage evaluation mechanism that includes the combined effects of fatigue damage and hydrogen embrittlement stress corrosion for the working environment of hydrogen storage tanks, resulting in errors in the assessment and early warning of defect expansion status.

[0004] At the same time, most of the existing hydrogen storage tank monitoring systems are used to monitor and warn of hydrogen leaks, while the detection of hydrogen storage tank damage mainly relies on regular inspections, which requires a large workload and the defect information cannot be obtained in real time, and early monitoring and danger warning of microcrack damage in hydrogen storage tanks have not been established. Summary of the invention

[0005] The present invention provides a hydrogen embrittlement cracking early warning method and system for a hydrogen storage tank based on acoustic emission technology, so as to solve the technical problems that the existing hydrogen storage tank monitoring technology has errors in the evaluation and early warning of the defect expansion status, and the existing hydrogen storage tank monitoring technology has a large workload and the defect information cannot be obtained in real time.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0007] On the one hand, the present invention provides a hydrogen storage tank hydrogen embrittlement cracking early warning method based on acoustic emission technology, the hydrogen storage tank hydrogen embrittlement cracking early warning method based on acoustic emission technology comprises:

[0008] Arrange an acoustic emission sensor on the hydrogen storage tank to be monitored, and collect the acoustic emission signal generated during the whole process of hydrogen embrittlement and cracking of the hydrogen storage tank to be monitored in real time through the arranged acoustic emission sensor;

[0009] Calculate the stress intensity factor based on the collected acoustic emission signal;

[0010] Based on the calculated stress intensity factor and the preset hazard level judgment criteria, the hazard level of the hydrogen storage tank crack is judged in real time, and a graded warning of the hydrogen embrittlement and cracking process of the hydrogen storage tank is given according to the hazard level.

[0011] Furthermore, the response frequency of the acoustic emission sensor includes a frequency band of 150kHz; the arrangement distance between the preamplifier and the acoustic emission sensor is within 5m; when the arrangement distance between the preamplifier and the acoustic emission sensor cannot be controlled within 5m, an acoustic emission sensor with a built-in preamplifier is selected.

[0012] Furthermore, the step of arranging an acoustic emission sensor on the hydrogen storage tank to be monitored includes:

[0013] A plurality of acoustic emission sensors are staggeredly arranged along the circumference of the tank body on the cylindrical tank body of the hydrogen storage tank, and the acoustic emission sensors are arranged in multiple rows to form a circumferential diamond array; an acoustic emission sensor is arranged on each side of the thick-walled pipe of the central vent port on the tank top, an acoustic emission sensor is arranged on each side of the thick-walled pipe of the central sewage outlet at the tank bottom, an acoustic emission sensor is arranged at each weld on both sides of the manhole along the longitudinal direction of the tank body, and a plurality of acoustic emission sensors are arranged equidistantly along the circumference of the tank bottom and the tank top; wherein the distance between any adjacent acoustic emission sensors does not exceed the maximum detection distance of the acoustic emission sensor; and the distance between the acoustic emission sensors located at both ends of the diamond diagonal in the circumferential diamond array does not exceed the maximum detection distance of the acoustic emission sensor.

[0014] Further, the calculating of the stress intensity factor based on the collected acoustic emission signal includes:

[0015] Mining the collected acoustic emission signals to extract effective information; wherein the effective information includes: the change rate of the number of acoustic emission events, the change rate of the location of the acoustic emission events, the average frequency of the acoustic emission signals, and the energy of the acoustic emission signals;

[0016] Calculate the real-time crack growth rate based on the extracted effective information;

[0017] Based on the calculated crack growth rate, the stress intensity factor is calculated.

[0018] Furthermore, the calculation formula of the crack growth rate is:

[0019]

[0020]

[0021] in, represents the calculated real-time crack growth rate; β(t) represents the rate deviation coefficient; It indicates the rate of change of the location of the acoustic emission event; Among them, A0, A1, A2, A3, B1, B2 and B3 are the acoustic emission coefficients of the hydrogen storage tank material. represents the rate of change of the number of acoustic emission events, f represents the frequency of the acoustic emission signal, and E represents the energy of the acoustic emission signal.

[0022] Furthermore, the calculation formula of the stress intensity factor is:

[0023]

[0024]

[0025] Wherein, ΔK represents the calculated stress intensity factor; C0, C1, C2 and m are the material constants of the hydrogen storage tank; p is the internal pressure of the hydrogen storage tank; is the fatigue crack growth rate; φ is the cyclic loading time.

[0026] Furthermore, based on the calculated stress intensity factor, according to the preset hazard level determination criteria, the hazard level of the crack of the hydrogen storage tank is determined in real time, and a graded early warning of the hydrogen embrittlement cracking process of the hydrogen storage tank is performed according to the hazard level, including:

[0027] When ΔK ≥ K IC When the crack danger level of the hydrogen storage tank is judged to be level 1, a level 1 warning is issued, indicating that the crack may cause the tank to fail. IC is the fracture toughness constant of the hydrogen storage tank material;

[0028] When ΔK ≥ K th or When the hydrogen storage tank crack danger level is judged to be level 2, a level 2 warning is issued, indicating that the initial crack has appeared. th is the stress intensity factor trigger threshold constant.

[0029] On the other hand, the present invention also provides a hydrogen embrittlement and cracking early warning system for a hydrogen storage tank based on acoustic emission technology, the hydrogen embrittlement and cracking early warning system for a hydrogen storage tank based on acoustic emission technology comprising:

[0030] An acoustic emission sensor is arranged on the hydrogen storage tank to be monitored to collect in real time the acoustic emission signal generated during the whole process of hydrogen embrittlement and cracking of the hydrogen storage tank to be monitored;

[0031] A signal processing module, used for calculating the stress intensity factor based on the collected acoustic emission signal;

[0032] The hydrogen storage tank crack hazard level determination and graded warning module is used to determine the hydrogen storage tank crack hazard level in real time based on the stress intensity factor calculated by the signal processing module and according to preset hazard level determination criteria, and to provide graded warning of the hydrogen embrittlement cracking process of the hydrogen storage tank according to the hazard level.

[0033] On the other hand, the present invention further provides an electronic device, comprising a processor and a memory; wherein the memory stores at least one instruction, and the instruction is loaded and executed by the processor to implement the above method.

[0034] In yet another aspect, the present invention further provides a computer-readable storage medium, wherein the storage medium stores at least one instruction, and the instruction is loaded and executed by a processor to implement the above method.

[0035] The beneficial effects brought about by the technical solution provided by the present invention include at least:

[0036] The present invention is based on acoustic emission technology to sensitively capture microcracks generated by hydrogen embrittlement and fatigue in the early stage of the hydrogen storage tank body, calculate the length and position of the cracks generated during the service of the hydrogen storage tank, and can detect the crack propagation rate and direction in real time. At the same time, the present invention constructs an early warning method and system for the service environment of the hydrogen storage tank, comprehensively considers fatigue damage and hydrogen embrittlement damage to establish an early warning level, thereby realizing real-time monitoring and quantitative evaluation and early warning in accordance with the service environment of the hydrogen storage tank, which can play a role in the early prevention of hydrogen storage accidents. The technical solution of the present invention is particularly suitable for real-time monitoring and evaluation of defect damage during the service of the hydrogen storage tank. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0038] Figure 1 It is a schematic diagram of the execution flow of the hydrogen embrittlement cracking early warning method for a hydrogen storage tank based on acoustic emission technology provided in an embodiment of the present invention;

[0039] Figure 2 Schematic diagram of the arrangement of the acoustic emission sensor provided in an embodiment of the present invention in the hydrogen storage tank body; wherein (a) is a cross-sectional view; (b) is an expanded view; and (c) is a top view.

[0040] Description of reference numerals:

[0041] 1. Vent port; 2. Safety valve interface; 3. Spare port; 4. Temperature measuring port; 5. Air inlet and outlet; 6. Ladder; 7. Support; 8. Sewage outlet; 9. Grounding plate; 10. Acoustic emission sensor wire tube; 11. Manhole; 12. Acoustic emission sensor; 13. Lifting lug; 14. Pressure gauge port. DETAILED DESCRIPTION

[0042] In order to make the objectives, technical solutions and advantages of the present invention more clear, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0043] First embodiment

[0044] This embodiment provides a hydrogen embrittlement cracking warning method for hydrogen storage tanks based on acoustic emission technology, which is used for defect damage monitoring and early warning of hydrogen storage tanks in service. The method obtains crack defect information through acoustic emission technology, and constructs a stress intensity factor warning model based on a functional relationship to achieve real-time monitoring and early warning of early defects in hydrogen storage tanks, which is particularly suitable for hydrogen embrittlement cracking monitoring and early warning of hydrogen storage tanks. The method can be implemented by electronic equipment. The execution process of the method is as follows Figure 1 As shown, the following steps are included:

[0045] S1, arranging an acoustic emission sensor on the hydrogen storage tank to be monitored, and collecting the acoustic emission signal generated by the whole process of hydrogen embrittlement cracking of the hydrogen storage tank to be monitored in real time through the arranged acoustic emission sensor;

[0046] Among them, the response frequency of the acoustic emission sensor should include a frequency band near 150kHz; the arrangement distance between the preamplifier and the acoustic emission sensor is within 5m; when the arrangement distance between the preamplifier and the acoustic emission sensor cannot be controlled within 5m, an acoustic emission sensor with a built-in preamplifier is used as a substitute.

[0047] Furthermore, if Figure 2 As shown, when arranging the acoustic emission sensor 12 on the hydrogen storage tank body to be monitored, the arrangement method is: a plurality of acoustic emission sensors 12 are staggeredly arranged along the circumference of the tank body on the cylindrical tank body part of the hydrogen storage tank, and the acoustic emission sensors 12 are arranged in multiple rows to form a circumferential diamond array; an acoustic emission sensor 12 is arranged on each side of the thick-walled pipe of the central vent 1 on the tank top, an acoustic emission sensor 12 is arranged on each side of the thick-walled pipe of the central sewage outlet 8 on the tank bottom, an acoustic emission sensor 12 is arranged near each weld on both sides of the manhole 11 along the longitudinal direction of the tank body, and a plurality of acoustic emission sensors 12 are arranged equidistantly along the circumference of the tank bottom and the tank top; wherein the distance between any adjacent acoustic emission sensors 12 does not exceed the maximum detection distance of the acoustic emission sensor 12; and the distance between the acoustic emission sensors 12 located at both ends of the diamond diagonal in the circumferential diamond array does not exceed the maximum detection distance of the acoustic emission sensor 12.

[0048] Specifically, see Figure 2 In this embodiment, the total volume of the hydrogen storage tank is 13.9m 3, where the height of the cylindrical tank is 4.76m, the diameter is 1.80m, and the diameter of the tank top and tank bottom is 1.35m. Acoustic emission sensors 12 are arranged in three rows along the circumference of the tank body of the hydrogen storage tank, with four arranged in each row; one is arranged on each side of the thick-walled pipe of the central vent 1 on the top of the tank; one is arranged on each side of the thick-walled pipe of the central sewage outlet 8 on the bottom of the tank; one is arranged on each side of the manhole along the longitudinal direction, for a total of 18. Under the premise of meeting this arrangement, the acoustic emission sensor 12 is arranged as close as possible to the pipe weld.

[0049] S2, calculate the stress intensity factor based on the collected acoustic emission signal;

[0050] Specifically, in this embodiment, the above S2 includes the following steps:

[0051] S21, mining the collected acoustic emission signals to extract effective information to determine whether microcracks have occurred and where they have occurred; wherein the effective information includes: a change rate of the number of acoustic emission events, a change rate of the location of the acoustic emission events, an average frequency of the acoustic emission signals, and an energy of the acoustic emission signals;

[0052] Specifically, the implementation process of S21 is as follows: a threshold value is set according to the actual environmental noise, the number of acoustic emission events is recorded as event count n, and when n ≥ 0, the event is triggered, the timing starts from zero, and the event count change rate is calculated. Determine the real-time position coordinates (x, y, z) of the event based on the positioning model of the acoustic emission software and calculate the rate of position change And get the average frequency of the acoustic emission signal and the acoustic emission signal energy E.

[0053] Average frequency of acoustic emission signal The and signal energy E are calculated by the following formulas:

[0054]

[0055]

[0056] Among them, z(t) is the original signal sequence of acoustic emission, f is the instantaneous frequency of the original signal, and Z(f) is the Fourier transform of the signal z(t).

[0057] S22, calculate the real-time crack growth rate based on the extracted effective information;

[0058] The calculation formula of crack growth rate is:

[0059]

[0060]

[0061] in, represents the calculated real-time crack growth rate; β(t) represents the rate deviation coefficient;

[0062] is the crack growth rate calculated based on the acoustic emission parameters, calculated by the following formula:

[0063]

[0064] Among them, A0, A1, A2, A3, B1, B2 and B3 are all acoustic emission coefficients of hydrogen storage tank materials, f represents the frequency of acoustic emission signals, and E represents the energy of acoustic emission signals.

[0065] Specifically, in this embodiment, the acoustic emission coefficient of the hydrogen storage tank body material is determined through experiments, and the experiments are conducted using samples with the same materials and processing techniques as those used for the hydrogen storage tank in this embodiment.

[0066] S23, calculating the stress intensity factor based on the calculated crack growth rate.

[0067] The calculation formula of stress intensity factor is:

[0068]

[0069]

[0070] Wherein, ΔK represents the calculated stress intensity factor; C0, C1, C2 and m are the material constants of the hydrogen storage tank; p is the internal pressure of the hydrogen storage tank; is the fatigue crack growth rate; φ is the cyclic loading time.

[0071] Specifically, in this embodiment, the variables φ and p depend on the actual working state and are obtained according to the real-time data of the process monitoring system. The material constants of the hydrogen storage tank body are determined through experiments, and the experiments are carried out using samples with the same materials and processing processes as those used for the hydrogen storage tank in this embodiment.

[0072] S3, based on the calculated stress intensity factor and the preset hazard level judgment criteria, judge the hazard level of the hydrogen storage tank crack in real time and conduct graded warning of the hydrogen embrittlement and cracking process of the hydrogen storage tank according to the hazard level.

[0073] Specifically, the above S3 processes the monitoring data in real time and gives the determination result, which is as follows:

[0074] When ΔK ≥ K IC When the crack danger level of the hydrogen storage tank is judged to be level 1, a level 1 warning is issued, indicating that the crack may cause the tank to fail. IC is the fracture toughness constant of the hydrogen storage tank material;

[0075] When ΔK ≥ K th or When the hydrogen storage tank crack danger level is judged to be level 2, a level 2 warning is issued, indicating that the initial crack has appeared. th is the stress intensity factor trigger threshold constant.

[0076] Specifically, in this embodiment, K IC It was determined through experiments that the experiment was conducted using a sample with the same material and processing technology as the hydrogen storage tank in this embodiment; K th Calculated by empirical formula as follows:

[0077] ΔK thCF =(2.17±0.25)×10 -3 E0(MN / m 3 / 2 )

[0078] Where E0 is the Young's elastic modulus of the material (unit is MN / m 3 / 2 ), determined through experiments, the experiments were conducted using samples with the same materials and processing techniques as those used for the hydrogen storage tank in this embodiment.

[0079] In summary, this embodiment provides a hydrogen embrittlement cracking warning method for hydrogen storage tanks based on acoustic emission technology. This method uses acoustic emission technology to sensitively capture microcracks caused by hydrogen embrittlement and fatigue in the early stage of the hydrogen storage tank body, calculate the length and position of the cracks generated during the service of the hydrogen storage tank, and can detect the crack propagation rate and direction in real time. In addition, this method comprehensively considers fatigue damage and hydrogen embrittlement damage to establish a warning level, so that microcracks caused by hydrogen embrittlement can be sensitively monitored, and real-time monitoring and timely warning of early defects in hydrogen storage tanks can be achieved, which plays a role in the early prevention of hydrogen storage accidents and lays the foundation for the early prevention of hydrogen storage safety accidents.

[0080] Second embodiment

[0081] This embodiment provides a hydrogen embrittlement cracking early warning system for a hydrogen storage tank based on acoustic emission technology, including:

[0082] An acoustic emission sensor is arranged on the hydrogen storage tank to be monitored to collect in real time the acoustic emission signal generated during the whole process of hydrogen embrittlement and cracking of the hydrogen storage tank to be monitored;

[0083] A signal processing module, used for calculating the stress intensity factor based on the collected acoustic emission signal;

[0084] The hydrogen storage tank crack hazard level determination and graded warning module is used to determine the hydrogen storage tank crack hazard level in real time based on the stress intensity factor calculated by the signal processing module and according to preset hazard level determination criteria, and to provide graded warning of the hydrogen embrittlement cracking process of the hydrogen storage tank according to the hazard level.

[0085] The hydrogen embrittlement and fracture warning system for hydrogen storage tanks based on acoustic emission technology of this embodiment corresponds to the hydrogen embrittlement and fracture warning method for hydrogen storage tanks based on acoustic emission technology of the first embodiment mentioned above; wherein, the functions implemented by each functional module in the hydrogen embrittlement and fracture warning system for hydrogen storage tanks based on acoustic emission technology of this embodiment correspond one by one to each process step in the hydrogen embrittlement and fracture warning method for hydrogen storage tanks based on acoustic emission technology of the first embodiment mentioned above; therefore, they will not be repeated here.

[0086] Third embodiment

[0087] This embodiment provides an electronic device, which includes a processor and a memory; wherein the memory stores at least one instruction, and the instruction is loaded and executed by the processor to implement the method of the first embodiment.

[0088] The electronic device may have relatively large differences due to different configurations or performances, and may include one or more processors (central processing units, CPU) and one or more memories, wherein the memory stores at least one instruction, and the instruction is loaded by the processor to execute the above method.

[0089] Fourth embodiment

[0090] This embodiment provides a computer-readable storage medium, which stores at least one instruction, and the instruction is loaded and executed by a processor to implement the method of the first embodiment. The computer-readable storage medium may be a ROM, a random access memory, a CD-ROM, a magnetic tape, a floppy disk, an optical data storage device, etc. The instructions stored therein may be loaded by a processor in a terminal to execute the method.

[0091] In addition, it should be noted that the present invention can be provided as a method, an apparatus or a computer program product. Therefore, the embodiments of the present invention can take the form of a complete hardware embodiment, a complete software embodiment or an embodiment combining software and hardware. Moreover, the embodiments of the present invention can take the form of a computer program product implemented on one or more computer-usable storage media containing computer-usable program code.

[0092] The embodiments of the present invention are described with reference to the flowcharts and / or block diagrams of the methods, terminal devices (systems), and computer program products according to the embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of the processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, an embedded processor, or other programmable data processing terminal device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing terminal device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0093] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing terminal device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce a manufactured product including an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 These computer program instructions can also be loaded onto a computer or other programmable data processing terminal device, so that a series of operation steps are executed on the computer or other programmable terminal device to produce a computer-implemented process, so that the instructions executed on the computer or other programmable terminal device provide for implementing the process in the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0094] It should also be noted that, in this article, the terms "include", "comprises" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or terminal device including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or terminal device. In the absence of further restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the process, method, article or terminal device including the elements.

[0095] Finally, it should be noted that the above is a preferred embodiment of the present invention. It should be pointed out that although the preferred embodiment of the present invention has been described, for those skilled in the art, once the basic creative concept of the present invention is known, several improvements and modifications can be made without departing from the principles of the present invention, and these improvements and modifications should also be regarded as the protection scope of the present invention. Therefore, the attached claims are intended to be interpreted as including the preferred embodiment and all changes and modifications that fall within the scope of the embodiments of the present invention.

Claims

1. A hydrogen embrittlement cracking early warning method for hydrogen storage tanks based on acoustic emission technology, characterized in that: include: Arrange an acoustic emission sensor on the hydrogen storage tank to be monitored, and collect the acoustic emission signal generated by the whole process of hydrogen embrittlement and cracking of the hydrogen storage tank to be monitored in real time through the arranged acoustic emission sensor; Calculate the stress intensity factor based on the collected acoustic emission signal; Based on the calculated stress intensity factor and the preset hazard level judgment criteria, the hazard level of the hydrogen storage tank crack is judged in real time, and a graded warning of the hydrogen embrittlement cracking process of the hydrogen storage tank is carried out according to the hazard level; The step of calculating the stress intensity factor based on the collected acoustic emission signal includes: Mining the collected acoustic emission signals to extract effective information; wherein the effective information includes: the change rate of the number of acoustic emission events, the change rate of the location of the acoustic emission events, the average frequency of the acoustic emission signals, and the energy of the acoustic emission signals; Calculate the real-time crack growth rate based on the extracted effective information; Based on the calculated crack growth rate, the stress intensity factor is calculated; The calculation formula of the crack growth rate is: in, represents the calculated real-time crack growth rate; β(t) represents the rate deviation coefficient; It indicates the rate of change of the location of the acoustic emission event; Among them, A0, A1, A2, A3, B1, B2 and B3 are the acoustic emission coefficients of the hydrogen storage tank material. represents the rate of change of the number of acoustic emission events, f represents the frequency of the acoustic emission signal, and E represents the energy of the acoustic emission signal; The calculation formula of the stress intensity factor is: Wherein, ΔK represents the calculated stress intensity factor; C0, C1, C2 and m are the material constants of the hydrogen storage tank; p is the internal pressure of the hydrogen storage tank; is the fatigue crack growth rate; φ is the cyclic loading time.

2. The hydrogen embrittlement cracking early warning method for hydrogen storage tanks based on acoustic emission technology according to claim 1 is characterized in that: The response frequency of the acoustic emission sensor includes a frequency band of 150kHz; the arrangement distance between the preamplifier and the acoustic emission sensor is within 5m; when the arrangement distance between the preamplifier and the acoustic emission sensor cannot be controlled within 5m, an acoustic emission sensor with a built-in preamplifier is selected.

3. The hydrogen embrittlement cracking early warning method for hydrogen storage tanks based on acoustic emission technology according to claim 1 is characterized in that: The step of arranging an acoustic emission sensor on the hydrogen storage tank to be monitored includes: A plurality of acoustic emission sensors are staggeredly arranged along the circumference of the tank body on the cylindrical tank body of the hydrogen storage tank, and the acoustic emission sensors are arranged in multiple rows to form a circumferential diamond array; an acoustic emission sensor is arranged on each side of the thick-walled pipe of the central vent port on the tank top, an acoustic emission sensor is arranged on each side of the thick-walled pipe of the central sewage outlet at the tank bottom, an acoustic emission sensor is arranged at each weld on both sides of the manhole along the longitudinal direction of the tank body, and a plurality of acoustic emission sensors are arranged equidistantly along the circumference of the tank bottom and the tank top; wherein the distance between any adjacent acoustic emission sensors does not exceed the maximum detection distance of the acoustic emission sensor; and the distance between the acoustic emission sensors located at both ends of the diamond diagonal in the circumferential diamond array does not exceed the maximum detection distance of the acoustic emission sensor.

4. The hydrogen embrittlement cracking early warning method for hydrogen storage tanks based on acoustic emission technology according to claim 1 is characterized in that: Based on the calculated stress intensity factor, according to the preset hazard level judgment criteria, the hazard level of the crack of the hydrogen storage tank is judged in real time, and a graded warning of the hydrogen embrittlement cracking process of the hydrogen storage tank is performed according to the hazard level, including: When ΔK ≥ K IC When the crack danger level of the hydrogen storage tank is judged to be level 1, a level 1 warning is issued, indicating that the crack may cause the tank to fail. IC is the fracture toughness constant of the hydrogen storage tank material; When ΔK ≥ K th or When the hydrogen storage tank crack danger level is judged to be level 2, a level 2 warning is issued, indicating that the initial crack has appeared. th is the stress intensity factor trigger threshold constant.

5. A hydrogen embrittlement cracking early warning system for hydrogen storage tanks based on acoustic emission technology, characterized in that: include: An acoustic emission sensor is arranged on the hydrogen storage tank to be monitored to collect in real time the acoustic emission signal generated during the whole process of hydrogen embrittlement and cracking of the hydrogen storage tank to be monitored; A signal processing module, used for calculating the stress intensity factor based on the collected acoustic emission signal; A hydrogen storage tank crack hazard level determination and graded warning module is used to determine the hydrogen storage tank crack hazard level in real time based on the stress intensity factor calculated by the signal processing module and according to a preset hazard level determination criterion, and to provide a graded warning of the hydrogen embrittlement cracking process of the hydrogen storage tank according to the hazard level; The step of calculating the stress intensity factor based on the collected acoustic emission signal includes: Mining the collected acoustic emission signals to extract effective information; wherein the effective information includes: the change rate of the number of acoustic emission events, the change rate of the location of the acoustic emission events, the average frequency of the acoustic emission signals, and the energy of the acoustic emission signals; Calculate the real-time crack growth rate based on the extracted effective information; Based on the calculated crack growth rate, the stress intensity factor is calculated; The calculation formula of the crack growth rate is: in, represents the calculated real-time crack growth rate; β(t) represents the rate deviation coefficient; It indicates the rate of change of the location of the acoustic emission event; Among them, A0, A1, A2, A3, B1, B2 and B3 are the acoustic emission coefficients of the hydrogen storage tank material. represents the rate of change of the number of acoustic emission events, f represents the frequency of the acoustic emission signal, and E represents the energy of the acoustic emission signal; The calculation formula of the stress intensity factor is: Wherein, ΔK represents the calculated stress intensity factor; C0, C1, C2 and m are the material constants of the hydrogen storage tank; p is the internal pressure of the hydrogen storage tank; is the fatigue crack growth rate; φ is the cyclic loading time.

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