A large container leakage detection system and a leakage source location method

Abstract

The present invention relates to the field of leakage detection of large containers such as oil storage tanks, natural gas storage tanks, spacecraft environmental simulation equipment, and large spacecraft cabins. The present invention proposes a leakage detection system and method for large containers based on an acoustic sensor array. By installing a plurality of wireless sensors on the wall of the container to be measured to form a wireless transmission acoustic emission leak detection system, according to a certain control method and positioning algorithm, real-time detection of leakage can be carried out in a large range, and no personnel operation is required throughout the process. The sensors in this method are powered by batteries and transmit data wirelessly. During the entire detection process, there is no need to lay cables, which greatly improves the leak detection efficiency.

Description

Field of the Invention

[0001] The present invention relates to the field of leakage detection of large containers such as oil storage tanks, natural gas storage tanks, spacecraft environmental simulation equipment, and large spacecraft cabins. Background Art

[0002] In the large industrial field, large containers such as oil storage tanks, natural gas storage tanks, spacecraft environmental simulation equipment, and large spacecraft cabins have a diameter exceeding 10 meters and a volume exceeding 1000 m 3 , and currently, traditional leakage location methods mainly use the bubble method or the helium mass spectrometry suction method. Both methods require personnel to conduct inspections with equipment, resulting in low leak detection efficiency. The detection values are restricted by personnel experience, and the detection results are unstable. Moreover, most containers store flammable and explosive media, and personnel detection poses a huge safety hazard. This invention patent proposes a large container leakage location method based on a wireless acoustic sensor array, which utilizes the attenuation characteristics of leakage sound waves on the container wall to achieve rapid leakage location of large containers. Summary of the Invention

[0003] The present invention proposes a large container leakage detection system and method based on an acoustic sensor array. By installing multiple wireless sensors on the wall of the container to be measured, a wireless transmission acoustic emission leakage detection system is formed. Utilizing the attenuation characteristics of leakage sound waves on the container wall, real-time detection of leakage can be carried out within a large range according to a certain control method and positioning algorithm, and no personnel operation is required throughout the process. The sensors in this method are powered by batteries and transmit data wirelessly. During the entire detection process, there is no need to lay cables, which greatly improves the leak detection efficiency.

[0004] The present invention provides a large container leakage detection method based on an acoustic sensor array, including the following steps:

[0005] (1) Install sensors on the container wall according to a certain layout to form a sensor array;

[0006] (2) Number all sensors, denoted as N ij (i = 1, 2, ……, n; j = 1, 2, ……, m), where i represents the i-th row, j represents the j-th sensor from the left in each row, n is the number of rows of sensors, m is the number of sensors in each row, and the total number of sensors is denoted as N n×m ;

[0007] (3) Establish a coupling coefficient matrix A of the sensor array;

[0008] (4) Establish a leakage sound wave intensity attenuation coefficient matrix C;

[0009] (5) Turn on all sensors to receive leakage signals. When the signal received by any one sensor increases by 3 times and lasts for more than 1 second, it is determined that leakage has occurred;

[0010] (6) Record the energy value S of the signals received by all sensors Lij (i = 1, 2, ……, n, j = 1, 2, ……, m), to obtain a two-dimensional matrix D; (7)

[0012] Slice the three-dimensional matrix C into N two-dimensional sub-matrices C in the N direction n×m n×m ij , Subtract the two-dimensional matrix D from each of the N two-dimensional matrices C one by one and sum the squares to obtain Z n×m ij Nij = |D - C ij | 2 , and find the N sensor corresponding to the minimum value of Z. The leakage source is in the area near the N sensor; Nij ij ij

[0013] (8) Use the leakage signals received by the sensors N, N, N, N, N around the N sensor to perform cross-correlation time difference positioning to obtain the accurate position of the leakage source. ij i(j-1) i(j+1) (i-1)j (i+1)j

[0014] Preferably, the sensor includes a receiving sensor, a charge amplification module, a digital sampling module, a wireless communication module, a transmitting sensor, a lithium battery, a WIFI antenna, and a mechanical housing.

[0015] Preferably, the sensors are arranged in an equilateral triangle honeycomb pattern or a square pattern.

[0016] Preferably, the sensor spacing is generally 10 - 20 meters, and several more sensors are arranged at more parts with discontinuous structures on the container surface. The discontinuous structures are welds or penetrators.

[0017] Preferably, the coupling coefficient of the sensor is calibrated before leakage detection. The specific steps are as follows: The transmitting sensor of each sensor transmits a standard signal S0, and the signal received by the receiving sensor is S Nij , then the coupling coefficient α of the Nth sensor ij Nij = (S Nij / S0) 1 / 2 , traverse all sensors to obtain the two-dimensional matrix A of the coupling coefficients of the sensor array. If α Nij is less than 0.5, the N sensor needs to be reinstalled. ij

[0018] ​​​​​​​​​​​​​​Preferably, the steps for establishing the leakage acoustic wave intensity attenuation coefficient matrix are as follows: Assume that the transmitting sensor of any one of the sensors (N i0j0 ) emits a standard signal S0, and the signal energy values S Nij (i = 1, 2, ……, n, j = 1, 2, ……, m) received by all sensors are traversed through all the transmitting sensors N ij , and a three-dimensional matrix B of the leakage acoustic wave intensity attenuation coefficient of the sensor array is obtained.

[0019] Furthermore, the steps for establishing the leakage acoustic wave intensity attenuation coefficient matrix with improved stability are as follows: Assume that the transmitting sensor of any one of the multifunctional integrated sensors (N i0j0 ) emits a signal S′0 with an energy value 10 times that of the standard signal energy value, and the signal energy values S′ Nij (i = 1, 2, ……, n, j = 1, 2, ……, m) received by all sensors are traversed through all the transmitting sensors N ij , and a three-dimensional matrix B′ of the leakage acoustic wave intensity attenuation coefficient of the sensor array is obtained. Take the average value of the three-dimensional matrices B and B′, denoted as C.

[0020] The advantages of the present invention are as follows:

[0021] 1. The present invention proposes a large container leakage positioning system based on wireless signal transmission. All devices are powered by batteries without the need to lay cables. The sensors are directly adsorbed on the surface of the large container by means of magnetic adsorption, which is very convenient to use.

[0022] 2. The leakage positioning method of the present invention is particularly suitable for the leakage detection of large containers, especially for large containers with a volume of more than 10,000 cubic meters.

[0023] 3. The leakage positioning method of the present invention fully considers the influence of structures such as welds and penetrations on the acoustic wave propagation and reduces its influence on leakage positioning.

[0024] 4. The leakage positioning method of the present invention uses the method of signal energy attenuation for rough leakage positioning. When using the method of signal attenuation for rough leakage positioning, matrix information is utilized, with stronger stability, effectively avoiding positioning errors caused by interference of individual sensor signals, etc.

[0025] 5. The leakage positioning method of the present invention combines the signal energy attenuation positioning method and the cross-correlation time difference positioning method, improving the positioning stability and positioning accuracy.

[0026] 6. The multifunctional integrated sensor used in the present invention has a built-in transmitting sensor and a receiving sensor, which can automatically calibrate the sensor coupling situation, avoiding positioning errors caused by poor coupling. Description of the Drawings

[0027] Figure 1 It is a schematic diagram of the sensor system structure.

[0028] Figure 2 It is a schematic diagram of the structure of the wireless transmission acoustic emission leak detection system.

[0029] Figure 3 It is a schematic diagram of the sensor layout.

[0030] Figure 4 It is a flow chart for leak location. Specific implementation manners

[0031] The following is the specific implementation manner as the content of the present invention. The content of the present invention will be further clarified through the specific implementation manner below. Of course, the description of the following specific implementation manners is only for exemplifying the content of different aspects of the present invention and should not be construed as limiting the scope of the present invention.

[0032] Embodiment 1

[0033] The large container leak detection system based on an acoustic sensor array has the functions of perceiving, collecting, transmitting, and storing leak signals. The schematic diagram of the structure of the large container leak detection system based on an acoustic sensor array is as Figure 2 shown. The system mainly consists of a multi-functional integrated sensor, a router, a computer, etc. The multi-functional integrated sensor includes a receiving sensor, a charge amplification module, a digital sampling module, a wireless communication module, a transmitting sensor, a lithium battery, a WIFI antenna, and a mechanical housing (including a push switch, an electrical interface, an indicator light, a magnet, etc.), and has the functions of perceiving - collecting - transmitting leak signals, and can calibrate the sensor coupling condition and the sound speed through the transmitting sensor. The end faces of the receiving sensor and the transmitting sensor are smeared with a coupling agent such as vacuum grease and directly adsorbed to the container wall through a magnet.

[0034] Embodiment 2

[0035] (1) Install the sensors on the container wall. Generally, a regular triangular honeycomb layout is adopted, or a square layout can also be adopted according to needs. The sensor spacing is generally 10 - 20 meters. For parts with more discontinuous structures such as welds and penetrations, arrange as many sensors as possible.

[0036] (2) Number all the sensor nodes, denoted as N ij (i = 1, 2, ……, n; j = 1, 2, ……, m), where i represents the i-th row and j represents the j-th sensor from the left in each row, n is the number of rows of sensors, and m is the number of sensors in each row. The total number of sensors is N n×m .

[0037] (3) Establish the coupling coefficient matrix of the sensor array

[0038] Since different sensor coupling situations will lead to inconsistent sensor sensitivities, the coupling coefficient of the sensor is calibrated before leak detection. Each transmitting sensor of the sensor emits a standard signal S0, and the signal received by the receiving sensor is S Nij , then for the N ij th sensor, the coupling coefficient α Nij = (S Nij / S0) 1 / 2 . By traversing all sensors, a two-dimensional matrix A of the coupling coefficients of the sensor array is obtained. If α Nij is less than 0.5, the N ij sensor needs to be reinstalled.

[0039] (4) Establish a leakage acoustic wave intensity attenuation coefficient matrix

[0040] The intensity of the leakage acoustic wave will attenuate during propagation in the medium. By establishing a leakage acoustic wave intensity attenuation map of the entire measured area, the location of the leak can be estimated. To more accurately estimate the leak location, a leakage acoustic wave intensity attenuation coefficient matrix needs to be established first.

[0041] Each transmitting sensor of the sensor emits a standard signal S0, and the signal received by the receiving sensor is S Nij , then for the N ij th sensor, the coupling coefficient α Nij = (S Nij / S0) 1 / 2 . By traversing all sensors, a two-dimensional matrix A of the coupling coefficients of the sensor array is obtained. If α Nij is less than 0.5, the N ij sensor needs to be reinstalled.

[0042] To improve stability, let the transmitting sensor of any one of the multi-functional integrated sensors (N i0j0 ) emit a signal S′0 with an energy value 10 times that of the standard signal energy value, and the signal energy values S′ Nij (i = 1, 2,..., n, j = 1, 2,..., m) received by all sensors. By traversing all the transmitting sensors N ij , a three-dimensional matrix B′ of the leakage acoustic wave intensity attenuation coefficients of the sensor array is obtained. Take the average value of the three-dimensional matrices B and B′ and denote it as C.

[0043] (5) Turn on all sensors to receive the leakage signal. When the signal received by any one sensor increases by 3 times and lasts for more than 1 second, it can be considered that a leak has occurred.

[0044] (6) Record the energy values S Lij of the signals received by all sensors(i = 1, 2, ……, n, j = 1, 2, ……, m), a two-dimensional matrix D is obtained;

[0045] (7) The three-dimensional matrix C is sliced into N n×m two-dimensional sub-matrices C n×m in the N ij direction. The square sum of the differences between the two-dimensional matrix D and the N n×m two-dimensional matrices C ij is calculated one by one to obtain Z Nij = |D - C ij | 2 , and the N Nij sensor corresponding to the minimum value of Z is found. The leakage source is in the area near the N ij sensor; ij

[0046] (8) Using the leakage signals received by the sensors N ij around the N i(j-1) sensor, namely N i(j+1) , N (i-1)j , N (i+1)j , cross-correlation time difference positioning is performed to obtain the accurate position of the leakage source.

Claims

1. A large container leakage detection method based on an acoustic sensor array, characterized in that Including the following steps: (1) Install sensors on the wall of the container according to a certain layout to form a sensor array; (2) Number all the sensors and denote them as N ij (i = 1, 2, ……, n; j = 1, 2, ……, m), where i represents the i-th row, j represents the j-th sensor from the left in each row, n is the number of rows of sensors, m is the number of sensors in each row, and the total number of sensors is denoted as N n×m ; (3) Establish the coupling coefficient matrix A of the sensor array; (4) Establish the leakage acoustic wave intensity attenuation coefficient matrix C; The specific steps are as follows: a) Suppose any one of the sensors (N i0j0 ) has its transmitting sensor emit a standard signal S0, and the signal energy values S Nij (i = 1, 2, ……, n, j = 1, 2, ……, m) received by all sensors are traversed through all the transmitting sensors N ij , and a three-dimensional matrix B of the leakage acoustic wave intensity attenuation coefficient of the sensor array is obtained; b) Suppose any one of the multifunctional integrated sensors (N i0j0 ) emits a signal S′0 with an energy value 10 times the standard signal energy value, and the signal energy values S′ Nij (i = 1, 2, ……, n, j = 1, 2, ……, m) received by all sensors. Traverse all the transmitting sensors N ij , obtain the three-dimensional matrix B′ of the leakage acoustic wave intensity attenuation coefficient of the sensor array, and take the average value of the three-dimensional matrices B and B′, denoted as C; (5) Turn on all sensors to receive leakage signals. When the signal received by any one sensor increases by 3 times and lasts for more than 1 second, it is determined that leakage has occurred; (6) Record the energy value S of the leakage signals received by all sensors Lij (i = 1, 2, ……, n, j = 1, 2, ……, m), to obtain a two-dimensional matrix D; (7) Split the three-dimensional matrix C into N n×m two-dimensional sub-matrices C n×m in the N ij direction, and calculate the sum of squares of the differences between the two-dimensional matrix D and N n×m two-dimensional matrices C ij one by one to obtain Z Nij = |D - C ij | 2 , and find the N Nij sensor corresponding to the minimum value of Z. The leakage source is in the area near the N ij sensor; ij ​ (8) Using N ij Sensors N around the sensor i(j-1) and N i(j+1) and N (i-1)j and N (i+1)j The received leakage signals are used for cross-correlation time difference positioning to obtain the accurate location of the leakage source.

2. The large container leakage detection method based on an acoustic sensor array according to claim 1, characterized in that, The sensor includes a receiving sensor, a charge amplification module, a digital sampling module, a wireless communication module, a transmitting sensor, a lithium battery, a WIFI antenna and a mechanical housing.

3. The method for detecting leakage of a large container based on an acoustic sensor array according to claim 2, characterized in that, The sensors are arranged in a regular triangular honeycomb layout or a square layout.

4. The method for detecting leakage of a large container based on an acoustic sensor array according to claim 3, characterized in that, The distance between the sensors is generally 10 - 20 meters. Several sensors are arranged at the discontinuous structure parts on the surface of the container. The discontinuous structure is generally a weld or a penetrator.

5. The method for detecting leakage of a large container based on an acoustic sensor array according to claim 1, characterized in that, Before leakage detection, a calibration operation of the sensor coupling coefficient is also carried out.

6. The method for detecting leakage of a large container based on an acoustic sensor array according to claim 5, characterized in that, The calibration operation steps of the sensor coupling coefficient are as follows: The transmitting sensor of each sensor transmits a standard signal S0, and the signal received by the receiving sensor is S Nij , then for the N ij th sensor, the coupling coefficient α Nij = (S Nij / S0) 1 / 2 . Traverse all the sensors to obtain the two-dimensional matrix A of the coupling coefficients of the sensor array. If α Nij is less than 0.5, the N ij sensor needs to be reinstalled.

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