Air leak detection system

Abstract

In particular, the invention relates to a leak detection system for the precise and effective measurement of the location of air leaks in pneumatic systems, the leak severity indicating the air flow rate in the leak, and the provision of detailed information such as the measured values and the amount of leak loss to the user.

Description

[0001] DESCRIPTION

[0002] AIR LEAK DETECTION SYSTEM

[0003] Technical Field

[0004] The invention relates to a leak detection system for effectively measuring the location and severity of air leaks and informing the user.

[0005] In particular, the invention relates to a leak detection system for the precise and effective measurement of the location of air leaks in pneumatic systems, the leak severity indicating the air flow rate in the leak, and the provision of detailed information such as the measured values and the amount of leak loss to the user.

[0006] State of the Art

[0007] Structures and connections in pneumatic systems may have damage or defects that cause air leakage. These air leaks cause the pressure in the system to drop, resulting in a decrease in the operating efficiency of the system or even a complete stop of operation. For this reason, it is important to detect these air leaks quickly and precisely and to eliminate the problem in order to reduce the operating efficiency, energy and cost losses of the system. Air leaks in pneumatic systems characteristically propagate in the frequency range of 25-40 kHz, and for this reason, the use of ultrasonic sound wave processing methods and systems containing ultrasonic microphones are preferred to detect such leaks. In air leak detection, microphones with analog or digital outputs are used to record sound in areas where air leakage is present and these recordings are compared. In the comparison, the amount of noise of the detected sound is important, and if the noise is too high, it is difficult to detect the sound frequencies of the leak and the detection is not realized. In this sense, due to the high noise level in the measurement environment, digital MEMS (micro-electronic-mechanical system) microphones are much more stable than analog microphones and enable measurements with up to 3 times lower noise levels. PDM (Pulse Density Modulation) MEMS microphones digitally detect and process sound. These very small system elements use PDM, a method of transmitting sound as a digital stream. The signal information here includes the intensity of the sound wave pulses and the loudness of the sound. Unlike conventional (analog) microphones, the signal is transmitted in digital form and therefore the noise received with the sound is much lower than with analog microphones.Existing air leak detection systems with microphones generally use the TDoA (Time Difference of Arrival) method to locate the leak-induced sound source by determining the direction / location. This method determines the position of the sound source by measuring the time differences as the sound reaches the microphone arrays. Typically, TDoA-based systems use microphone arrays of 32, 64 or 16 microphones. These arrays compare audio signals arriving at different times to determine the direction and distance of the sound source. However, TDoA-based systems require a high number of microphones, which increases production and maintenance costs and complicates installation. Again, advanced timing systems and hardware are needed to accurately measure the time differences between the microphones in these systems, making them difficult to use and prolonging the process. In addition, the use of a large number of microphones in the system increases power consumption and prevents the system from being portable / modular. Therefore, all these factors cause difficulties in terms of both production and utilization, and the measurement results obtained are not sufficient to accurately determine the leakage location and severity.

[0008] The patent document US3675053A, which is in the known state of the art, discloses an ultrasonic wave microphone having a high Q factor, comprising a resonator made of metal and a flat piezoelectric vibrator. The resonator is connected to the center of the piezoelectric vibrator, allowing the electrical properties of the microphone to be changed. This microphone is particularly suitable for use with devices such as television remote controls. An ultrasonic microphone device comprising a resonator connected to a piezoelectric vibrator, which is made of metal with a high Q factor and is connected to the center of the piezoelectric vibrator. The resonator allows easy and precise adjustment of the electrical characteristics of the microphone. By directing and amplifying vibrations, it increases the microphone's sensitivity and allows it to work more efficiently in certain frequency ranges. The document does not mention a solution for precise and accurate measurement of the location and leakage severity of air leaks, especially in pneumatic systems, and detailed communication of the measured values and information such as the amount of leakage loss to the user.

[0009] Another patent document US2014005958A1 of known art discloses an ultrasonic gas leak detector. It is configured to distinguish ultrasonic waves generated by the release of a pressurized gas leak into the atmosphere from ultrasonic signals that cause false alarms. In an example application, multiple acoustic sensors are used to detect acoustic energy and provide sensor signals. These sensors include a broadband sensor and at least one narrowband sensor. An electronic control unit that responds to signals from these sensors is also part of the system. An electronic control unit is equipped with a threshold comparison function that compares the sensor signal value of the detected ultrasonic energy with the gas leak detection threshold. In addition, ituses Artificial Neural Network (ANN) function to distinguish false alarm sources from real gas leaks by processing data from multiple sensor signals. The document does not mention a solution for precise and accurate measurement of the location and leakage severity of air leaks, especially in pneumatic systems, and detailed communication of the measured values and information such as the amount of leakage loss to the user.

[0010] As a result, in order to detect the location of air leaks in pneumatic systems, there is a need to develop a leak detection system that is customized according to the sound frequency range of the air leak and thus, the leak severity, which indicates the air flow rate in the leak, can be measured precisely and effectively, the measured values and information such as the amount of leak loss are given to the user in detail, and the leak detection process is carried out quickly, economically and effectively.

[0011] Purpose of the Invention

[0012] The present invention relates to a leak detection system which fulfills the above-mentioned requirements, eliminates possible disadvantages and provides some additional advantages.

[0013] The main purpose of the inventive leak detection system is to obtain a leak detection system that enables precise measurement of the position of air leaks and the intensity of air leak flow in pneumatic systems and to increase the effectiveness of leak detection.

[0014] Another object of the invention is to provide a functional leak detection system, which provides detailed information to the user, such as the values measured in the air leak detection process and the amount of leak loss.

[0015] Another object of the invention is to provide an effective leak detection system which increases the accuracy of the measurement process and the precision of position determination by reducing the noise values in the measurement process.

[0016] Another object of the invention is to obtain a leak detection system that provides fast and practical measurement in pneumatic systems of different types, models and sizes and elements of these systems by reducing the dimensions of the structure with its compact and modular structure.

[0017] Another object of the invention is to obtain an efficient leak detection system that reduces production and maintenance costs, workload and the need for specialized personnel / users.Another object of the invention is to provide a leak detection system that enables fast and accurate intervention in the event of an air leak, thereby increasing the duration and effectiveness of pneumatic system maintenance.

[0018] An alternative object of the invention is to provide a leak detection system which reduces the number of microphones used, reduces energy consumption and increases the duration of use during portable use when the detection system is not connected to a power line, and enables the measurement process to be carried out completely.

[0019] In order to achieve the above objectives in the most general form, a leak detection system for precisely measuring the position and severity of air leakage in pressurized systems providing air / gas flow, increasing the detection efficiency, and providing detailed information to the user includes at least one housing; at least one detection unit including at least four detection apertures and at least four sound detection elements; at least one processing unit including at least one conversion element.

[0020] The structural and characteristic features and all advantages of the invention will be more clearly understood by means of the figures given below and the detailed description written by making references to these figures, and therefore, the evaluation should be made by considering these figures and detailed description.

[0021] Figures to Help Understand the Invention

[0022] In order to best understand the structure and advantages of the present invention, it should be evaluated together with the figures described below.

[0023] Figure - 1: An exploded view of the inventive leak detection system.

[0024] Figure - 2: Another exploded view of the inventive leak detection system.

[0025] Figure - 3: A perspective view of the inventive leak detection system.

[0026] Part References

[0027] 1. Housing

[0028] 2. Detection unit

[0029] 2a. Detection aperture

[0030] 2b. Sound detection element

[0031] 3. Processing unit3a. Conversion element

[0032] 4. Control element

[0033] 5. Measuring element

[0034] 6. Display element

[0035] 7. Power storage element

[0036] 8. Data storage element

[0037] 9. Power button

[0038] T. Leak detection system

[0039] Detailed Description of the Invention

[0040] In this detailed description, the preferred embodiments of the leak detection system of the invention are described solely for the purpose of a better understanding of the subject matter and without any limiting effect.

[0041] At least one processing unit (3), comprises preferably an STM32 model microcontroller suitable for running the FFT (Fast Fourier T ransform) algorithm, which enables the separation of the sound into frequency components by processing the digital data obtained, the calculation of the amplitude difference in the frequencies of the leakage sound, the determination of the leakage position and intensity according to the focusing angle of the relevant detection aperture (2a) by determining from which sound detection element (2b) the sound signal containing the calculated amplitude difference is received; at least one conversion element (3a), preferably a DFSDM (Digital Filter for Sigma-Delta Modulator) module for the conversion of PDM (Pulse Density Modulation) signals into PCM (Pulse Code Modulation) signals, which is connected to the sound detection elements (2b), and which enables the conversion of the sound signals received from the sound detection elements (2b) into digital signal data; preferably in conical form with a length between the ends close to and far from the housing (1) of 8-12 cm, a diameter close to the housing (1) of 2.5 mm and a diameter far from the housing (1) of 3.4 cm to minimize noise during the detection of sound waves in the wavelength range, at least four detection apertures (2a), each of which is positioned at the end of one of the apertures (2a) close to the housing (1), to enable the sound waves transmitted through each detection aperture (2a) to be detected separately, so that the sound waves generated in the air / gas leak are guided and transmitted and the noise during transmission is reduced, at least one detection unit (2), preferably a PDM (Pulse Density Modulation) MEMS (micro-electronic-mechanical system) microphone, containing at least four sound detection elements (2b), extending on the first axis in connection with the housing (1), enabling the transfer of sound waves received from the leakage zone to the sound detection elements (2b) and increasing the measurement efficiency of the position and intensity values ofsound waves in the frequency range of 20-80 kHz; each of which is suitable for the passage of sound waves in the wavelength range of 4-9 mm, extending away from a first axis with a focusing angle value of 12-20 degrees from a first axis extending away from the user while the user carries the system (T) to improve focusing and capture sound waves in the wavelength range of 4-9 mm, and extending symmetrically with respect to the first axis and the second and third axes perpendicular to each other; to precisely measure the position of the air leak and the intensity of the air / gas flow at the leak point in pressurized systems, preferably pneumatic, which provide air / gas flow, and to increase the effectiveness of detecting the leak situation, the exemplary view of which is given in Figure 1, developed with the present invention, the leak detection system (T), which provides detailed transmission of measured values and leakage status information to the user, at least one housing (1), which is suitable for placing the elements of the system (T) inside, which enables the elements of the system (T) to be transported, protected from external influences and the system (T) to be comfortably grasped and carried by the user.

[0042] In an exemplary embodiment of the leak detection system (T) developed with the present invention, the system (T) is moved to the measurement site by the user grasping the housing (1). After the detection unit (2) is oriented to face the potential leakage area, sound waves in a certain frequency / wavelength range are received from the potential leakage area through the detection apertures (2a) and directed to the sound detection elements (2b). At this stage, the sound waves received from different angular positions are transmitted separately to each independent sound detection element (2b) by means of the detection apertures (2a), which are symmetrical with one another and with a focusing angle value of 12-20 degrees from the first axis mentioned, extending away from the user while the user is carrying the system (T). The detection apertures (2a) are conical in shape, each 8-12 cm in length and 2.5 mm-3.4 cm in diameter, in order to focus on and capture and transmit sound waves with a wavelength of 4-9 mm. The angular positioning of the sound detection elements (2b) at equal distances from each other ensures that each sound detection element (2b) is focused on a different area / location. In this way, the sound level to be detected by the sound detection element (2b) focusing on the leakage present in the environment is magnitude higher than the other three sound detection elements (2b) and the ratio of the sound levels between the sound detection elements (2b) determines precisely where the leakage is located spatially.

[0043] Four identical sound detection elements (2b) are specially designed to focus sound waves onto the microphone. The geometry of the detection apertures (2a) is optimized taking into account the focusing angle and the detection frequency of the sound detection elements (2b). In this sense, the size values of the detection apertures (2a) are compatible with the frequency range of 20-80 kHz and the 4-9 mm wavelength of the sound waves in this range. The relationship betweenthe wavelength and frequency of the sound wave is calculated by the following formula depending on the speed of sound (v=343 m / s):

[0044] A=v / f

[0045] = 8.575 millimeters forf=40 kHz

[0046] The diameter and length of the detection apertures (2a) are chosen to be approximately 10 times the wavelength to ensure accurate focusing of the air leakage sound waves. Tests have been carried out with tapered detection apertures (2a) of different lengths and angles, echo and focus criteria are analyzed and it is observed that the selected form of detection apertures (2a) gives the best performance [Table 1],

[0047]

[0048] Table 1: Noise measurement plots for different sized sensing apertures (2a).

[0049] The detection apertures (2a) are angularly positioned to direct the sound waves to the sound detection elements (2b). The angle between the detection apertures (2a) plays a critical role in directing the acoustic waves from the sound source towards the sound detection elements (2b). In the different sized samples in Table 1, the signals generated at 40 kHz and 20 V from the signal source are received from MEMS microphones. In the sample measurements, the PDM signals received from the MEMS microphones used as the sound detection element (2b) are converted to PCM format using the DFSDM module with conversion element (3a) on the STM32 microcontroller with processing unit (3). The PCM data is then processed with the FFT (Fast Fourier Transform) algorithm by means of the processing unit (3) and transferred from the time domain to the frequency domain. The FFT algorithm separates the frequency components of the sound, allowing the calculation of the amplitude values at the frequencies where the leakage sounds are present. The data at the specified frequency is converted into dB by mathematicaloperations. As a result of the processes, the amplitudes of the sounds at the propagation frequency of the air leaks are recorded in decibels. This is done by checking the performance of different sized detection apertures (2a), looking at the echo and selecting the model with the cleaner signal. Thus, the focusing 0=12-20° and the size of the detection aperture (2a) is chosen according to Example 5. Then, by means of the processing unit (3), each sound detection element (2b) detects sound waves at different angles, enabling precise measurement of amplitude differences. The sound detection elements (2b) are placed according to these angles so that the sound waves are focused from a certain direction towards the sound detection elements (2b).

[0050] In a preferred embodiment of the invention, the leak detection system (T) comprises at least one control element (4), preferably in the form of a touch screen, located on the surface of the housing (1) close to the user and connected to the processing unit (3), which enables the leak location and intensity values detected by processing the received sound waves and / or visually transferring them to the user on a map model and allowing the user to enter data / commands into the system (T). In addition, if a leak is detected, the leak point is marked with a circle on the map model shown in the control element (4) and preferably the diameter and color of the circle can change in proportion to the leak severity. Thus, the user can observe the amount and cost of leakage loss on the control element (4).

[0051] In another preferred embodiment of the invention, the leak detection system (T) comprises at least one measuring element (5), preferably a Lidar distance sensor, which enables the linear distance between the leak location and the system (T) to be measured after the leak location has been determined.

[0052] In another preferred embodiment of the invention, the leak detection system (T) comprises at least one display element (6), preferably a camera module, connected to the processing unit (3) and positioned on the side of the housing (1) or detection unit (2) which is remote from the user, enabling a snapshot to be taken of the measured leakage area and a photograph to be taken of the leak detection point.

[0053] In another preferred embodiment of the invention, the leak detection system (T) comprises at least one power storage element (7) in the form of a battery suitable for recharging, which is positioned in the housing (1) and provides storage of the energy required for portable use of the system (T).

[0054] In another preferred embodiment of the invention, the leak detection system (T) comprises at least one data storage element (8), preferably a memory card, in connection with the processingunit (3) and the measuring element (5), for storing all measurement data received and dB (decibel) values of sound waves measured for leaks of different flow and diameter values at a distance of one meter. Thus, after the leakage point is detected, the dB values of the sound wave obtained by keeping the system (T) 1 meter away from the leakage point are compared with the dB values stored in the data storage element (8) to determine the possible leakage amount and cost.

[0055] In another preferred embodiment of the invention, the leak detection system (T) comprises at least one power button (9) connected to the processing unit (1) and enabling the process to be started.

[0056] With the leak detection system (T) developed with the present invention, air leakage can be detected by the amplitude difference method using fewer sound detection elements (2b), and direction determination can be made by using the differences in the detected sound wave intensity. This results in a practical, efficient and effective leak detection system that does not require time difference calculation to determine the direction of the sound source, provides accurate measurement of amplitude differences with correct angular placement, provides highly accurate direction determination by reducing environmental noise, reduces installation, maintenance and repair costs, ease of use and reduces processing time.

Claims

CLAIMS1. A leak detection system (T) which provides a precise measurement of the air leak position and the air I gas flow intensity at the leak point in pressurized systems that provide air I gas flow, increases the effectiveness of detecting the leak situation, and transmits detailed measured values and leak status information to the user, characterized by;at least one housing (1) that is suitable for the placement of the elements of the system (T) in it, which enables the elements of the system (T) to be carried, protected from external influences and the system (T) to be comfortably grasped and carried by the user;at least one detection unit (2) that enables the transfer of sound waves received from the leakage zone to the mentioned sound detection elements (2b) and to increase the measurement efficiency of the position and intensity values of sound waves in the frequency range of 20-80 kHz, which extends on a first axis in connection with the housing (1), wherein the detection unit (2) comprises at least four detection apertures (2a) to provide transmission by guiding the sound waves generated in the air / gas leak and reduction noise during the transmission, wherein each of the detection apertures (2a) are suitable for passing sound waves in the wavelength range 4-9 mm through it, extending at a focusing angle value of 12-20 degrees away from a first axis that extends away from the user while the user is carrying the system (T) and symmetrically with respect to the first axis and the second and third axes perpendicular to each other, in order to improve the focusing and capture the sound waves in the wavelength range 4-9 mm and at least four sound detection elements (2b) to provide individual detection of the sound waves transmitted through each of the detection apertures (2a), wherein each of the sound detection elements (2b) are positioned at the end of one of the apertures (2a) close to the housing (1);at least one processing unit (3) that enables the separation of sound into frequency components by processing the digital data obtained, the calculation of the amplitude difference in the frequencies of the leakage sound, the determination of the leakage position and intensity according to the focusing angle of the relevant detection aperture (2a) by determining from which sound detection element (2b) the sound signal containing the calculated amplitude difference is received, wherein the processing unit (3) comprises at least one conversion element (3a) connected with the sound detection elements (2b), which enables the conversion of the sound signals received from the sound detection elements (2b) into digital signal data.

2. A leak detection system (T) according to claim 1, characterized in that; the pressurized system is pneumatic.

3. A leak detection system (T) according to claim 1 , characterized in that; each of the detection apertures (2a) is conical in shape with a length value of 8-12 cm, a diameter value of 2.5 mm close to the housing (1) and a diameter value of 3.4 cm away from the housing (1), with a length value of 8-12 cm between the ends close to and distant from the housing (1) to minimize noise during the detection of sound waves in said wavelength range.

4. A leak detection system (T) according to claim 1 , characterized in that; the sound detection elements (2b) are microphones with PDM (Pulse Density Modulation) MEMS (micro electronic-mechanical system).

5. A leak detection system (T) according to claim 1, characterized in that; the conversion element (3a) is a DFSDM (Digital Filter for Sigma-Delta Modulator) module for conversion of PDM (Pulse Density Modulation) signals to PCM (Pulse Code Modulation) signals.

6. A leak detection system (T) according to claim 1, characterized in that; the processing unit (3) is an STM32 model microcontroller suitable for running the FFT (Fast Fourier Transform) algorithm.

7. A leak detection system (T) according to claim 1 , characterized in that; the system (T) further comprises at least one control element (4), preferably in the form of a touch screen, positioned on the surface of the housing (1) close to the user and connected to the processing unit (3), which enables the leak location and intensity values detected by processing the received sound waves and / or visually transferring them to the user on a map model and enabling the user to enter data / commands into the system (T).

8. A leak detection system (T) according to claim 1 , characterized in that; the system (T) further comprises at least one measuring element (5), preferably a Lidar distance sensor, for measuring the linear distance between the leak location and the system (T) after determining the leak location.

9. A leak detection system (T) according to claim 1 , characterized in that; the system (T) further comprises at least one display element (6), preferably a camera module, connected to the processing unit (3) and positioned on the side of the housing (1) or detection unit (2) which isremote from the user, for taking a snapshot of the measured leakage area and photographing the leak detection point.

10. A leak detection system (T) according to claim 1, characterized in that; the housing (1) comprises at least one power storage element (7) in the form of a battery suitable for recharging, which is positioned in the housing (1) and which stores the energy required for portable use of the system (T).

11. A leak detection system (T) according to claim 8, characterized in that; the system (T) further comprises at least one data storage element (8), preferably a memory card, in connection with the processing unit (3) and the measuring element (5), for storing all measurement data received and the dB values of the sound waves measured for leaks of different flow and diameter values at a distance of one meter.

12. A leak detection system (T) according to claim 1 , characterized in that; the system (T) further comprises at least one power button (9) in connection with the processing unit (3) for initiating the process.

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