A device and method for monitoring corrosion of a sealing steel plate of an underground gas storage

Abstract

The application discloses a kind of underground gas storage sealing steel plate corrosion monitoring device and method, including ultrasonic probe and processor;Underground gas storage includes tubular sealing steel plate, and ultrasonic probe is installed on the inner side wall of sealing steel plate;Ultrasonic probe includes multiple ultrasonic probe groups spaced along the axial direction of sealing steel plate, each ultrasonic probe group includes multiple ultrasonic probe units spaced along the circumferential direction of sealing steel plate, and processor is electrically connected with each ultrasonic probe unit;Ultrasonic probe unit is configured to receive and send signal.Compared with prior art, the application can realize real-time monitoring and long-term monitoring of the corrosion of the sealing steel plate of underground gas storage, and can determine the corrosion core area and corrosion degree of the sealing steel plate, so as to repair and maintain the corrosion area of the sealing steel plate of the gas storage chamber in a targeted manner, thereby ensuring the safety and stability of the gas storage chamber during operation, continuous detection, low cost, high intelligence and good real-time detection results.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of corrosion detection, in particular to a device and method for monitoring corrosion of sealing steel plates of underground gas storage. BACKGROUND

[0002] Compressed air energy storage is a technology that uses compressed air as a medium to store energy and generate electricity. Currently, salt caverns and artificially excavated cavities are commonly used as gas storage containers. For newly built underground gas storage with artificially excavated cavities, gas tightness and stability are key technical difficulties. Currently, a steel lining concrete structure sealing system is commonly used. However, the steel lining of the underground gas storage is in a high-pressure and humid environment, and the problem of steel lining corrosion cannot be ignored. Currently, the common corrosion prevention method for steel lining concrete is to cover the surface with corrosion-resistant paint, and the steel plate generally has a corrosion allowance of more than 1mm. The current domestic standard requires that the design service life of the corrosion-resistant paint is generally not more than 20 years. If the corrosion-resistant paint is not monitored and repainted during operation, it is difficult to meet the service life of the gas storage. The corrosion allowance of the sealing steel plate cannot be seen and controlled during operation, and the corrosion condition is generally detected manually during maintenance. Currently, there is no precise and intelligent means for real-time monitoring.

[0003] Currently, the conventional methods for detecting steel plate corrosion include ultrasonic thickness measurement, resistance method, coupon weight loss method, etc. New detection methods include FSM field fingerprint method, resistance probe method, etc. The ultrasonic thickness measurement method uses ultrasonic waves to penetrate the material and measure the characteristics of the echo to detect the wall thickness and corrosion condition of the material. By measuring the time or amplitude change of the sound wave propagation, the thickness or corrosion degree of the material can be determined. The resistance method monitors the corrosion rate by measuring the change in resistance of the metal sample. The coupon weight loss method places corrosion coupons inside the pipeline or equipment, removes the coupons after a certain period of time, cleans and weighs them accurately, and indirectly infers the corrosion condition of the inner wall of the pipeline or equipment by calculating the corrosion amount and rate of the corrosion coupons. The FSM field fingerprint method monitors the resistance change by arranging an electrode matrix on the outside of the pipeline and setting a constant excitation current in the monitoring area, and then reflects the corrosion degree. The resistance probe method calculates the corrosion amount and corrosion rate by measuring the resistance change of the corroded metal during the corrosion process. The above existing detection methods are all manual detection under the condition of periodic maintenance and pressure relief, and have the problems of discontinuous detection, high cost, low intelligence, and poor real-time detection results. SUMMARY

[0004] The present application provides a device and method for monitoring corrosion of sealing steel plates of underground gas storage to solve the problems of discontinuous detection, high cost, low intelligence, and poor real-time detection results of the existing corrosion monitoring methods for sealing steel plates of underground gas storage.

[0005] To achieve the above-mentioned purpose, the present application adopts the following technical solutions.

[0006] In one aspect, a device for monitoring corrosion of a sealing steel plate of an underground gas storage is provided, comprising an ultrasonic probe and a processor; the underground gas storage comprises a tubular sealing steel plate, the ultrasonic probe is installed on an inner side wall of the sealing steel plate; the ultrasonic probe comprises a plurality of ultrasonic probe groups arranged in an axial direction of the sealing steel plate, each ultrasonic probe group comprises a plurality of ultrasonic probe units arranged in a circumferential direction of the sealing steel plate, and the processor is electrically connected with each ultrasonic probe unit; each ultrasonic probe unit is configured to receive and send signals.

[0007] In some embodiments, in each ultrasonic probe group, each ultrasonic probe unit is arranged uniformly.

[0008] In some embodiments, the interval between two adjacent ultrasonic probe groups is the same, and the positions of each ultrasonic probe unit in the two adjacent ultrasonic probe groups correspond to each other.

[0009] In another aspect, a method for monitoring corrosion of a sealing steel plate of an underground gas storage is provided, which is applied to the device for monitoring corrosion of the sealing steel plate of the underground gas storage; the method comprises:

[0010] S1, each ultrasonic probe unit receives an ultrasonic signal sent by an adjacent ultrasonic probe unit to obtain a plurality of monitoring sound pressures;

[0011] S2, if all the monitoring sound pressures are equal to a standard sound pressure, it is determined that the sealing steel plate has no corrosion;

[0012] if a monitoring sound pressure less than the standard sound pressure is detected, it is determined that the sealing steel plate has corrosion; wherein the standard sound pressure is a monitoring sound pressure obtained by each ultrasonic probe unit when the sealing steel plate has no corrosion.

[0013] In some embodiments, when the monitoring sound pressure less than the standard sound pressure is detected, the corrosion position is determined to be near the ultrasonic probe unit receiving the monitoring sound pressure.

[0014] In some embodiments, step S1 comprises: taking an ultrasonic signal sent by a first ultrasonic probe unit and received by a second ultrasonic probe unit as a monitoring sound pressure; wherein the first ultrasonic probe unit and the second ultrasonic probe unit are ultrasonic probe units in two adjacent ultrasonic probe groups, and the positions of the first ultrasonic probe unit and the second ultrasonic probe unit correspond to each other.

[0015] In some embodiments, when the sealing steel plate has corrosion, the diameter d2 of the corrosion point is calculated by the following formula:

[0016]

[0017] Wherein, c4 is the material scattering coefficient, F is the anisotropy coefficient, L is the interval distance between adjacent two ultrasonic probe groups, p1 x is the standard sound pressure, p2 x is the monitoring sound pressure, a is the refraction angle, and x is the distance from the detection point to the wave source.

[0018] In some embodiments, step S1 comprises: taking the ultrasonic signal sent by the first ultrasonic probe unit and received by the second ultrasonic probe unit as the monitoring sound pressure; wherein the first ultrasonic probe unit and the second ultrasonic probe unit are two adjacent ultrasonic probe units in the same ultrasonic probe group.

[0019] In some embodiments, when the sealed steel plate has corrosion, the diameter d2 of the corrosion point is calculated by the following formula:

[0020]

[0021] Wherein, c4 is the material scattering coefficient, F is the anisotropy coefficient, γ is the included angle between adjacent two ultrasonic probe units in the same ultrasonic probe group, D is the diameter of the sealed steel plate, p1 x is the standard sound pressure, p2 x is the monitoring sound pressure, a is the refraction angle, and x is the distance from the detection point to the wave source.

[0022] In another aspect, a computer device is provided, comprising a memory, a processor, and a computer program stored in the memory, wherein the processor executes the computer program to implement the steps of the above method.

[0023] The present application has at least the following technical effects or advantages: The present application can realize real-time monitoring and long-term monitoring of the corrosion of the sealed steel plate of the underground gas storage, and can determine the corrosion core area and the corrosion degree of the sealed steel plate, so as to target the repair and maintenance of the corrosion area of the sealed steel plate of the gas storage cavern, thereby ensuring the safety and stability of the gas storage cavern during operation. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 is a schematic view of the transverse section of the sealed steel plate corrosion monitoring device of the underground gas storage in an embodiment of the present application;

[0025] Figure 2 is a schematic view of the longitudinal section of the sealed steel plate corrosion monitoring device of the underground gas storage in an embodiment of the present application;

[0026] Figure 3 is a schematic view of the propagation path of the signal emitted by the ultrasonic probe in an embodiment of the present application. DETAILED DESCRIPTION

[0027] In order to better understand the above technical solutions, the above technical solutions will be described in detail below in combination with the drawings in the specification and specific embodiments.

[0028] Embodiment one

[0029] Referring to Figures 1-3 A corrosion monitoring device for a sealed steel plate of an underground gas storage comprises an ultrasonic probe and a processor 3. The underground gas storage comprises a tubular sealed steel plate 1, and the ultrasonic probe is installed on the inner side wall of the sealed steel plate. The ultrasonic probe comprises a plurality of ultrasonic probe groups arranged uniformly along the axial direction of the sealed steel plate, each ultrasonic probe group comprises a plurality of ultrasonic probe units 2 arranged uniformly along the circumferential direction of the sealed steel plate, and the processor is electrically connected with each ultrasonic probe unit 2. The ultrasonic probe unit 2 is configured to receive and send signals.

[0030] This embodiment shows three ultrasonic probe groups, namely Ai, Bi and Ci. In actual application, the number of ultrasonic probe groups can be greater than or equal to 2.

[0031] A monitoring area is set on the inner side of the sealed steel plate 1, and the ultrasonic probe is arranged on the inner side of the sealed steel plate 1. The received ultrasonic signals are transmitted to the processor through an optical fiber, and further data processing is performed by the processor to form the corrosion monitoring device for the sealed steel plate of the underground gas storage.

[0032] A schematic view of a transverse section of the corrosion monitoring device for the sealed steel plate of the underground gas storage is shown in Figure 1 , and a schematic view of a longitudinal section is shown in Figure 2 . The application environment of the monitoring device is a circular cross-section tunnel type compressed air energy storage power station underground gas storage. The diameter of the cross-section of this type of underground gas storage is large, and the diameter D is generally 5m to 14m. The traditional sealed steel plate + concrete sealing method is adopted, and the outer side directly contacts the surrounding rock. The sealed steel plate is generally made of ordinary carbon steel or high-strength steel. The sealed steel plate is made of thin steel plate, and the minimum thickness is generally 12mm to 30mm. The inner and outer sides are covered with a corrosion-resistant coating, and the thickness of the coating is generally 400μm to 1000μm. The ultrasonic probe is arranged in a ring shape on the inner side of the sealed steel plate, and the ring angle is γ. The ultrasonic probe is arranged in multiple rings, and the longitudinal distance is L. The angle and distance are related to the received sound wave intensity, the incident angle, the material properties to be measured, and the like, and should be determined by on-site ultrasonic transmission and reception tests. The probe is pasted or adsorbed to the inner surface of the sealed steel plate, and should have certain high-pressure and high-temperature resistance. The ultrasonic probe also has the functions of waveguide transmission and reception.

[0033] Embodiment two

[0034] A corrosion monitoring method for a sealed steel plate of an underground gas storage is applied to the corrosion monitoring device for the sealed steel plate of the underground gas storage described above. The method comprises the following steps:

[0035] S1, each ultrasonic probe unit receives ultrasonic signals transmitted from an adjacent ultrasonic probe unit to obtain a plurality of monitoring sound pressures.

[0036] S2, if all monitoring sound pressures are equal to the standard sound pressure, it is determined that the sealed steel plate has no corrosion;

[0037] If a monitoring sound pressure less than the standard sound pressure is detected, it is determined that the sealed steel plate has corrosion; wherein the standard sound pressure is the monitoring sound pressure obtained by each ultrasonic probe unit when the sealed steel plate has no corrosion. Specifically, at the initial stage of operation of the underground gas storage, the sealed steel plate has no corrosion, and the monitoring sound pressure at this time is obtained as the standard sound pressure. After a period of operation, if the sealed steel plate has corrosion, the monitoring sound pressure obtained will be less than the standard sound pressure, and at this time it can be determined that the sealed steel plate has corrosion.

[0038] Further, when a monitoring sound pressure less than the standard sound pressure is detected, the corrosion position is determined to be near the ultrasonic probe unit receiving the monitoring sound pressure.

[0039] Specifically, one of the monitoring methods is:

[0040] The ultrasonic signal received by the second ultrasonic probe unit and transmitted by the first ultrasonic probe unit is taken as the monitoring sound pressure; wherein the first ultrasonic probe unit and the second ultrasonic probe unit are ultrasonic probe units in two adjacent ultrasonic probe groups, and the positions of the first ultrasonic probe unit and the second ultrasonic probe unit correspond to each other.

[0041] At this time, if corrosion of the sealed steel plate is detected, the diameter d2 of the corrosion point can be calculated by the following formula:

[0042]

[0043] In the formula, c4 is the material scattering coefficient, F is the anisotropy coefficient, L is the interval distance between the two adjacent ultrasonic probe groups, p1 x is the standard sound pressure, p2 x is the monitoring sound pressure, a is the refraction angle, and x is the distance from the detection point to the wave source.

[0044] Another monitoring method is:

[0045] The ultrasonic signal received by the second ultrasonic probe unit and transmitted by the first ultrasonic probe unit is taken as the monitoring sound pressure; wherein the first ultrasonic probe unit and the second ultrasonic probe unit are two adjacent ultrasonic probe units in the same ultrasonic probe group.

[0046] At this time, if corrosion of the sealed steel plate is detected, the diameter d2 of the corrosion point can be calculated by the following formula:

[0047]

[0048] In the formula, c4 is the material scattering coefficient, F is the anisotropy coefficient, γ is the included angle between adjacent two ultrasonic probe units in the same ultrasonic probe group, D is the diameter of the sealed steel plate, p1 x is the standard sound pressure, p2 x is the monitoring sound pressure, α is the refraction angle, and x is the distance from the detection point to the wave source. The above parameters are known parameters.

[0049] Taking a domestic compressed air energy storage underground high-pressure gas storage as an example, the Q345R steel is used for the sealed steel plate of the gas storage cavern, ultrasonic probes arranged in a ring direction and a radial direction are pasted on the corrosion monitoring part of the sealed steel plate of the gas storage cavern, each ultrasonic probe has a signal receiving and transmitting function, each adjacent two ultrasonic probes (which can be two ultrasonic probe units corresponding to two positions in the adjacent two ultrasonic probe groups, or can be two adjacent ultrasonic probe units in the same ultrasonic probe group) can form a monitoring group, each group can be operated independently, the ultrasonic receiving and transmitting frequency is set, and the cyclic monitoring of each monitoring group can be realized. The sound wave intensity received by the ultrasonic probe is transmitted to the processor as raw data, the data is stored in the database, and the corrosion point position and diameter are confirmed after data analysis.

[0050] Among them, since the thickness of the sealed steel plate is generally small, an inclined probe is used for the ultrasonic probe, the refraction angle is 63°, the K value is a small value of 2.0, and the used ultrasonic wave meets the requirements of high frequency and short wavelength. The ultrasonic probe spacing L is 50 cm, the ring direction included angle is 10°, and the ultrasonic probe emits ultrasonic waves from the small label to the large label. At this time, only the adjacent large label ultrasonic probe receives the ultrasonic wave information, a pulse wave is used, the single probe emission time is 15 min, and then the cycle is switched to the next monitoring group. Wireless data transmission is used between the ultrasonic probe and the processor, and then the data is transmitted to the server through the special cable or optical fiber in the corridor and vertical shaft. When the corrosion point diameter d2 is greater than or equal to 1 mm, a steel plate corrosion early warning is issued, and a warning is given on the early warning platform. It is necessary to suspend the gas charging and discharging work of the gas storage cavern, and after the gas is discharged, the corrosion position of the sealed steel plate of the gas storage cavern is manually checked.

[0051] The principle of the above monitoring method is as follows:

[0052] Ultrasonic waves can be divided into plane waves and non-plane waves according to wave front. The vibration direction parallel to the propagation direction of ultrasonic plane wave is called longitudinal wave, and the vibration direction orthogonal to the propagation direction of ultrasonic plane wave is called transverse wave. Ultrasonic waves are mainly used for steel plate corrosion monitoring by using the plane wave characteristics of ultrasonic waves in the material. Ultrasonic waves will exist acoustic impedance in the solid material, and will be reflected, refracted and other phenomena when encountering the interface in the material. Firstly, ultrasonic waves with fixed frequency are emitted at the sound wave emitting point, and the sound wave energy curve of the sound wave after refraction, reflection and loss in the initial state of the steel plate without corrosion is collected at the sound wave receiving point. After multiple tests, the energy curve is used as the standard state energy curve for judging the steel plate without corrosion. In the corrosion monitoring process, the energy curve obtained at the actual sound wave receiving point is used as the original data.

[0053] When ultrasonic waves propagate in solid medium, the ultrasonic waves will cause energy loss, i.e. attenuation phenomenon, which mainly manifests as the decrease of amplitude. The attenuation of ultrasonic waves is divided into three types: diffusion attenuation, medium absorption attenuation and scattering attenuation.

[0054] Diffusion attenuation

[0055] During the propagation of ultrasonic waves, the amplitude energy of ultrasonic waves will become smaller and smaller with the increase of propagation distance due to the diffusion of sound beam. This phenomenon is called diffusion attenuation. Diffusion attenuation is caused by the propagation distance of ultrasonic waves in the medium and is independent of the propagation medium. The sound wave will weaken with the increase of propagation distance.

[0056] Medium absorption attenuation

[0057] Absorption causes attenuation. The particles vibrate under the action of ultrasonic waves, and there is a restraint force between the particles, which will hinder the vibration of the particles and cause the loss of sound energy. The lost sound energy is converted into heat energy. In the process of ultrasonic wave propagation, the heat energy gradually increases and the sound energy decreases due to the absorption of medium, which is called absorption attenuation.

[0058] Scattering attenuation

[0059] The main factor causing scattering attenuation of sound wave is the non-uniformity of a large number of crystal metals in the solid. Under the action of the grain boundary of polycrystal, ultrasonic waves will be reflected, refracted and wave shape converted. The scattering attenuation increases with the increase of ultrasonic frequency, and the attenuation caused by transverse wave is greater than that caused by longitudinal wave.

[0060] Attenuation equation and attenuation coefficient

[0061] Plane wave does not exist diffusion attenuation, but only medium attenuation (absorption attenuation and scattering attenuation), and the sound pressure attenuation equation is:

[0062] p x =p0e -ax ;

[0063] Wherein: p0 is the initial sound pressure of the wave source, p x is the sound pressure at a distance x from the wave source; x is the distance from the detection point to the wave source; a is the medium attenuation coefficient, e is the base of natural logarithm. The greater the attenuation coefficient of the ultrasonic wave, the more serious the ultrasonic wave energy attenuation, and under the same propagation medium, the higher the frequency of the ultrasonic wave, the greater the energy loss.

[0064] In the process of propagation of ultrasonic longitudinal wave, there is internal friction force in the medium, and kinetic energy and potential energy are converted into heat energy, resulting in loss of ultrasonic longitudinal wave energy.

[0065] The medium attenuation coefficient a is:

[0066] a=a a +a s ;

[0067] In the formula, a a is the absorption attenuation coefficient, and a s is the scattering attenuation coefficient.

[0068] The expression of the absorption attenuation coefficient is:

[0069] a a =c1f;

[0070] The expression of the scattering attenuation coefficient is:

[0071]

[0072] In the formula, f is the frequency of the ultrasonic wave; d is the grain diameter of the medium; λ is the wavelength; F is the anisotropy coefficient c1 is the material absorption coefficient, and c2, c3, c4 are the material scattering coefficients. c1, c2, c3, c4 are all constants.

[0073] λ=c / f;

[0074] In the formula, c is the wave velocity.

[0075] The ultrasonic wave exits the sound beam to tilt into the steel plate, when the complete steel plate has no corrosion, the sound beam is reflected in the workpiece multiple times to propagate in the "w" path, as shown in Figure 3 At this time, the ultrasonic wave receiving probe only receives the initial wave after absorption attenuation and scattering attenuation, and the sound pressure at the receiving position is p1 x ; When there is corrosion in the steel plate, the reflected wave generated by the sound beam at the corrosion point will be received by the rear receiving probe, including the initial wave and the defect wave after absorption attenuation and scattering attenuation, and the sound pressure at the receiving position is p2 x . For steel plate corrosion, the corrosion point can be understood as a special grain boundary, and it can be seen that when the ultrasonic wave velocity is constant, the larger the grain diameter, the stronger the scattering attenuation, the greater the scattering attenuation coefficient, and the smaller p2 x . When the corrosion degree reaches d≥λ, p2x Combined with the scattering attenuation law, the corrosion point diameter d2 is back calculated, and when d2 is greater than a certain threshold, a steel plate corrosion warning is issued.

[0076] Since the container steel plate grain diameter d0 is generally 0.01mm-0.03mm, the ultrasonic wavelength λ used is greater than d0, and a s The value is very small, and in this algorithm, the attenuation coefficient of the steel plate without corrosion only considers the absorption attenuation a a At this time, the sound pressure at a distance x from the wave source after attenuation is p1 x The steel plate without corrosion is the container steel plate detected by rust removal and flaw detection, which is regarded as the initial state; for the steel plate with corrosion, the steel plate with corrosion is regarded as the steel plate whose corrosion degree reaches the minimum corrosion accuracy that can be monitored by the present patent (corrosion point diameter d2≥λ), and the attenuation coefficient of the steel plate under test considers the absorption attenuation of the steel plate and the scattering attenuation at the corrosion site. At this time, the sound pressure at a distance x from the wave source after attenuation is p2 x When the corrosion degree does not reach the minimum corrosion accuracy that can be monitored by the present patent, p2 x =p1 x At this time, it is regarded as that the steel plate under test has no corrosion, and when p x2 <p1 x , the corrosion point diameter d2 is determined according to the following formula.

[0077]

[0078] a1=a a ;

[0079] a a =c1f;

[0080] a2=a a +a s ;

[0081] a s =c4F / d2;

[0082] For radial ultrasonic probe installation, i.e. between A i and B i :

[0083] x=L / sinα;

[0084] For ring ultrasonic probe installation, i.e. between A i and A i+1 :

[0085] x=γD / πsinα;

[0086] It can be obtained that:

[0087]

[0088] The calculation is as follows:

[0089]

[0090] For the radial ultrasonic probe, the diameter d2 of the corrosion point is A i and B i :

[0091]

[0092] For the ring ultrasonic probe, the diameter d2 of the corrosion point is A i and A i+1 :

[0093]

[0094] According to the duration of the ultrasonic sound source, it can be divided into pulse wave and continuous wave. The duration of continuous wave is longer than that of pulse wave. In combination with the purpose of corrosion monitoring and the slow nature of corrosion damage, when the corrosion state just occurs, there is no sudden damage to the overall structure of the sealed steel plate. Therefore, the influence of pulse wave as the sound source on the real-time monitoring can be ignored. At the same time, since each ultrasonic sensor has both receiving and transmitting functions, and multiple ultrasonic sensors are arranged on the sealed steel plate, in order to avoid interference between the sensors during operation, pulse wave is used and the transmission frequency characteristics of the ultrasonic wave are controlled.

[0095] When a corrosion warning occurs, the visualization interface will display the warning probe picture, in which green is the normal probe block and red is the alarm probe block. It is necessary to suspend the gas charging and discharging work of the gas storage cavern, and after discharging, the warning position is manually checked.

[0096] In the specification provided herein, a large number of specific details are described. However, it can be understood that the embodiments of the present application can be practiced without these specific details. In some examples, well-known methods, structures and techniques are not shown in detail in order not to obscure the understanding of the present specification.

[0097] Similarly, it is to be understood that the embodiments of the present application can be alternately practiced by a single integrated circuit, in different combinations of hardware and software, or in entirely hardware embodiments.

[0098] It will be appreciated by persons skilled in the art that modules or units or groups of the examples disclosed herein can be arranged in a device as described in the examples, or in different devices from those described in the examples. The modules in the above-described examples can be combined or further divided into additional modules or sub-modules. It will be appreciated that combinations of the above modules or units or groups can form special purpose devices or general purpose devices. It will also be appreciated that such devices can be provided as part of a larger system including a computer or other processor, or provided as standalone devices.

[0099] It will be appreciated that, for obviating the need for a detailed understanding of the internal workings of the devices in the examples, the devices in the examples can be implemented in a different manner from that described in the examples. It will be appreciated by persons skilled in the art that the modules in the devices in the examples can be adapted and placed in one or more devices different from those in the examples. The modules in the examples can be combined into one module or further divided into additional sub-modules.

[0100] Furthermore, to one of ordinary skill in the art, embodiments that differ from the examples that are described herein can be practiced, as appreciated by those skilled in the art, that the combination of features of different embodiments implies that the features in question are within the scope of the application and form different embodiments.

[0101] Furthermore, some of the embodiments described herein are of a machine that is intended to be understood as a legal, physical, and / or electronic equivalent of a human being. Furthermore, the embodiments described herein can be implemented as a machine that is intended to be understood as a legal, physical, and / or electronic equivalent of a human being.

[0102] The various techniques described herein can be implemented in connection with hardware or software or, where appropriate, with a combination of both. Thus, the methods and apparatus of the present application, or certain aspects or portions thereof, can take the form of program code (i.e., instructions) embodied in tangible media, such as floppy diskettes, CD-ROMs, hard drives, or any other machine-readable storage medium wherein, when the program code is loaded into and executed by a machine, such as a computer, the machine becomes an apparatus for practicing the subject application.

[0103] Where a program code is executed on a programmable computer, the computing device generally includes a processor, a storage medium readable by the processor (including volatile and non-volatile memory and / or storage elements), at least one input device, and at least one output device. The storage medium is configured to store program code whose execution implements the methods of the application. The program code can be implemented in a high level procedural or object-oriented programming language to communicate with a computer system. Alternatively, the program code can be implemented in assembly or machine language, if desired.

[0104] In the context of this document, a "computer-readable medium" can be any means that can store, communicate, propagate, or transport the program for use by or in connection with the computer. The computer readable medium can be, for example but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, or a propagation medium. The computer-readable medium can be a computer- readable storage medium or a computer-readable communication medium. The computer-readable storage medium can be, for example, but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, or a propagation medium. The computer-readable communication medium can be, for example, but not limited to, wired media such as a wired network or direct-wired connection, and wireless media such as acoustic, radio frequency, infrared, and other wireless media. Combinations of the any of the above can also be included within the scope of computer-readable media.

[0105] As used herein, unless otherwise indicated, the use of the ordinal adjectives "first", "second", "third", etc., merely to distinguish different instances of an object to which the adjective refers, and are not intended to denote a given sequence or order of such objects. Thus, a reference to first and second components, for example, does not imply that the component will be employed prior to or following each other, in some embodiment, such components can be integrated within a single process.

[0106] While the application has been described in terms of several embodiments, those skilled in the art will recognize that the application can be practiced with modifications and alterations limited only by the spirit and scope of the claims. The teachings of the application provided herein can be applied to other systems, not only for the systems directly or indirectly related to the disclosure. Accordingly, the disclosure is intended to embrace all such alterations, modifications, and variations that fall within the scope and spirit of the appended claims. In addition, while a particular feature of the application can have been disclosed with respect to only one of several embodiments, such feature can be combined with one or more other features of the same or different embodiments as can be desired and advantageous for any given or

[0107] Finally, it is to be understood that the application is not limited in its application to the details of the construction and the arrangement of the components set forth in the description or illustrated in the drawings. The application is capable of other embodiments and of being practiced or being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and not of limitation.

Claims

1. A device for monitoring corrosion of a steel plate of a seal of an underground gas storage, characterized in that The application relates to an ultrasonic detection device for a sealed steel plate of an underground gas storage, which comprises an ultrasonic probe and a processor; the underground gas storage comprises a tubular sealed steel plate, the ultrasonic probe is arranged on the inner side wall of the sealed steel plate; the ultrasonic probe comprises a plurality of ultrasonic probe groups arranged along the axial direction of the sealed steel plate, each ultrasonic probe group comprises a plurality of ultrasonic probe units arranged along the circumferential direction of the sealed steel plate, and the processor is electrically connected with the ultrasonic probe units. The ultrasonic probe unit is configured to receive and send signals. The processor is configured to: acquire the monitoring sound pressures obtained by the second ultrasonic probe units from the ultrasonic wave signals sent by the first ultrasonic probe units; when all the monitoring sound pressures are equal to the standard sound pressure, it is judged that the sealed steel plate is not corroded; when a monitoring sound pressure less than the standard sound pressure is detected, it is judged that the sealed steel plate is corroded; wherein the standard sound pressure is the monitoring sound pressure obtained by the ultrasonic probe units when the sealed steel plate is not corroded; when it is judged that the sealed steel plate is corroded, if the first ultrasonic probe unit and the second ultrasonic probe unit are ultrasonic probe units in two adjacent ultrasonic probe groups respectively, and the positions of the first ultrasonic probe unit and the second ultrasonic probe unit correspond to each other, the diameter d2 of the corrosion point is calculated through the following formula: if the first ultrasonic probe unit and the second ultrasonic probe unit are two adjacent ultrasonic probe units in the same ultrasonic probe group, the diameter d2 of the corrosion point is calculated through the following formula: In the formula, c4 is a material scattering coefficient, F is an anisotropy coefficient, L is a spacing distance between adjacent two ultrasonic probe groups, γ is an included angle between adjacent two ultrasonic probe units in the same ultrasonic probe group, D is a diameter of the sealed steel plate, p1 x is a standard sound pressure, p2 x is a monitoring sound pressure, α is a refraction angle, and x is a distance from a detection point to a wave source.

2. The underground gas storage reservoir seal steel sheet corrosion monitoring apparatus according to claim 1, characterized by: In each ultrasonic probe group, the ultrasonic probe units are uniformly arranged.

3. The underground gas storage reservoir seal steel sheet corrosion monitoring apparatus according to claim 1 or 2, characterized by: The intervals between the adjacent two ultrasonic probe groups are the same, and the positions of the ultrasonic probe units in the adjacent two ultrasonic probe groups correspond to each other.

4. The underground gas storage cavern seal steel sheet corrosion monitoring apparatus according to claim 1 or 2, characterized by, The processor is configured to determine that the corrosion position is near the ultrasonic probe unit receiving the monitoring sound pressure less than the standard sound pressure.

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