Gas leakage positioning system based on photoacoustic spectrum equipment and intelligent prediction

Abstract

The invention relates to the technical field of acousto-optic fusion, in particular to a gas leakage positioning system based on photoacoustic spectrum equipment and intelligent prediction, which comprises a comprehensive evaluation module, a gas leakage detection module, a gas leakage detection module and a positioning module, re-determining the leakage risk parameter according to the relationship between the leakage risk parameter and the early warning leakage coefficient, so as to determine the time interval for obtaining the leakage risk parameter based on the insufficient value of the leakage risk parameter relative to the standard leakage parameter; wherein the early warning leakage coefficient is determined according to the leakage risk parameter and the standard leakage parameter, and the leakage risk parameter is determined according to the evaluation concentration, the evaluation decrease rate and the evaluation frequency band. Whether the gas leaks or not and the leakage position can be comprehensively determined through a plurality of parameters such as the components of the gas, the pressure change and the sound frequency band of the gas flowing out of the leakage position, and the reaction speed of processing the gas leakage is increased.

Description

Technical Field

[0001] This invention relates to the field of acoustic-optical fusion technology, and in particular to a gas leak location system based on photoacoustic spectroscopy equipment and intelligent prediction. Background Technology

[0002] Gas leak detection is a crucial topic in industrial safety, widely applied in industries such as petrochemicals, natural gas transportation, manufacturing, and energy and power. Gas leaks can lead to not only economic losses, such as energy waste and equipment damage, but also serious safety accidents, such as explosions, fires, and toxic gas poisoning, posing a significant threat to human life and the environment.

[0003] Chinese Patent Publication No. CN118936753A discloses a method and system for spatially locating gas leak sources. The method includes: performing a three-dimensional model of the actual space where the monitored scene is located, and establishing a three-dimensional spatial grid number-process block name lookup table; capturing images of the monitored scene using a first-view imaging monitor from a first visual direction, and capturing images of the monitored scene using a second-view imaging monitor from a second visual direction; dividing the first captured image into a planar grid to determine the first planar grid number where the leak source is located, and dividing the second captured image into a planar grid to determine the second planar grid number where the leak source is located; mapping the first and second planar grid numbers to a three-dimensional grid space, and determining the location of the leak source and the corresponding process block name according to the three-dimensional spatial grid number-process block name lookup table. Therefore, the method and system for spatially locating gas leak sources have the following problems: It is impossible to comprehensively determine whether a gas leak has occurred and its location by using multiple parameters such as gas composition, pressure changes, and the sound frequency band of gas flowing from the leak location, thus failing to accelerate the response speed for handling gas leaks. Summary of the Invention

[0004] To address this, the present invention provides a gas leak location system based on photoacoustic spectroscopy equipment and intelligent prediction, which overcomes the problem in the prior art that it is impossible to comprehensively determine whether a gas leak has occurred and the location of the leak by using multiple parameters such as gas composition, pressure changes, and the sound frequency band of the gas flowing out of the leak location, thereby accelerating the response speed to gas leak handling.

[0005] To achieve the above objectives, the present invention provides a gas leak location system based on photoacoustic spectroscopy equipment and intelligent prediction, comprising: A photoacoustic spectroscopy detection module is installed on the pipeline transporting the gas to acquire the photoacoustic signal of the target gas, determine the gas leakage range based on the judgment result of the evaluation concentration and the risk failure, and determine the entry into the risk warning process according to the relationship between the evaluation concentration and the preset concentration; wherein, the evaluation concentration is determined based on the analysis of gas composition based on photoacoustic signal. A pressure detection module, corresponding to the photoacoustic spectroscopy detection module, is installed on the pipeline transporting the gas. It is used to obtain the actual pressure value of the target gas, determine the gas leakage range based on the evaluation drop rate to identify the seal failure, and determine the risk warning process based on the relationship that the evaluation drop rate is greater than the preset drop rate. The evaluation drop rate is determined based on continuous actual pressure values. A low-frequency acoustic detection module is installed on the pipeline transporting gas, distributed on both sides of the photoacoustic spectroscopy detection module. It is used to acquire the sound frequency band of the transporting gas pipeline, determine the gas leakage range based on the judgment result of the acoustic energy not meeting the standard based on the evaluation frequency band, and determine the risk warning process based on the relationship between the evaluation frequency band and the preset frequency band. The evaluation frequency band is determined based on the acoustic frequency band. The comprehensive evaluation module determines the gas leakage range based on the leakage risk parameters to identify unqualified gas transportation conditions. It then re-determines the leakage risk parameters based on the relationship between the leakage risk parameters and the early warning leakage coefficient. The time interval for obtaining the leakage risk parameters is determined based on the insufficient value of the leakage risk parameters relative to the standard leakage parameters. The early warning leakage coefficient is determined based on the leakage risk parameters and the standard leakage parameters, and the leakage risk parameters are determined based on the evaluation concentration, the evaluation decline rate, and the evaluation frequency band.

[0006] Furthermore, the process by which the photoacoustic spectroscopy detection module determines the risk compliance includes: Compare and evaluate the concentration with the risk concentration to determine the risk compliance. In response to the risk assessment being deemed unacceptable, the upstream pipeline valve is shut off, and the location of the gas leak is determined based on the evaluation concentration from the upstream photoacoustic spectroscopy detection module.

[0007] Furthermore, the process by which the photoacoustic spectroscopy detection module determines whether to enter the risk warning process includes, Compare and evaluate the concentration with the preset concentration to determine the compliance of the components; In response to the determination that a component is unqualified, a first deviation value between the evaluated concentration and the preset concentration is determined to determine the leakage risk parameter.

[0008] Furthermore, the process by which the pressure detection module determines the seal's compliance includes: Compare and evaluate the rate of decrease in risk with the rate of decrease in risk to determine the seal's compliance. In response to the determination that the seal is unqualified, the upstream pipeline valve is shut off, and the gas leak location is determined by combining the evaluation drop rate of the upstream pressure detection module.

[0009] Furthermore, the process by which the pressure detection module determines whether to enter the risk warning process includes: Compare and evaluate the rate of decrease with the preset rate of decrease to determine the compliance of the pressure change; In response to the determination that the pressure change is unqualified, a second deviation value between the evaluated drop rate and the preset drop rate is determined to determine the leakage risk parameters.

[0010] Furthermore, the process by which the low-frequency acoustic detection module determines the acoustic energy qualification includes: Compare and evaluate the frequency band with the risk frequency band to determine the suitability of the acoustic energy. In response to the determination that the acoustic energy is unqualified, the upstream pipeline valve is closed, and the gas leak location is determined by combining the evaluation frequency band of the upstream low-frequency acoustic detection module.

[0011] Furthermore, the process by which the low-frequency acoustic detection module determines whether to enter the risk warning process includes: Compare the evaluation frequency band with the preset frequency band to determine the sound quality. In response to the determination that the sound is unqualified, a third deviation value between the evaluation frequency band and the preset frequency band is determined to determine the leakage risk parameters.

[0012] Furthermore, the process by which the comprehensive evaluation module determines the qualification of gas transportation includes: The gas transportation qualification is determined by comparing leakage risk parameters with standard leakage parameters. In response to the determination that the gas transport is substandard, the upstream pipeline valve is shut off, and the gas leak location is determined based on the insufficient value.

[0013] Furthermore, the process by which the comprehensive evaluation module redetermines the leakage risk parameters includes, By comparing the leakage risk parameters with the early warning leakage parameters, and in response to the leakage risk parameters being greater than the early warning leakage parameters, the leakage risk parameters are re-determined to re-evaluate the gas transportation qualification.

[0014] Furthermore, the time interval for obtaining the leakage risk parameter is positively correlated with the insufficient value.

[0015] Compared with the prior art, the beneficial effect of the gas leak location system based on photoacoustic spectroscopy device and intelligent prediction of the present invention is that it can comprehensively determine whether there is a gas leak and the location of the leak by using multiple parameters such as gas composition, pressure change and sound frequency band of gas flowing out from the leak location, thereby speeding up the response speed to deal with gas leaks.

[0016] Furthermore, by detecting photoacoustic signals in the transported target gas, the concentration of the target gas at the current detection point is determined. Based on the relationship between the evaluated concentration at the current detection point and the preset concentration, in cases where there is no clear gas leak but the target gas concentration fluctuates, the gas transport is evaluated comprehensively in conjunction with other parameters to determine whether the gas transport is qualified in the absence of a clear gas leak. This avoids misjudging gas leaks due to initial concentration fluctuations of the target gas during transport, which might be caused by relying solely on the evaluated concentration to determine whether a gas leak has occurred. This allows for more accurate determination of the gas leak status, improving detection accuracy. It also allows for a comprehensive evaluation of the gas transport status based on leak risk parameters, effectively predicting the location of gas leaks so that repairs can be carried out before a leak occurs, effectively preventing gas leaks from happening. Furthermore, it allows for timely closure of upstream valves in the gas leak area after a leak occurs, preventing continued gas leakage and potential safety accidents.

[0017] Furthermore, by combining the evaluation concentration of a single parameter with the boundary concentration (i.e., the risk concentration) that would not occur during gas transportation if no gas leak has occurred, the potential for gas leakage in the transported gas can be determined. This avoids situations where the evaluation concentration is severely substandard even when no gas leak has occurred, leading to inaccurate comprehensive evaluation of the gas transportation status based on leakage risk parameters. This ensures that gas leaks are determined from multiple dimensions. Moreover, if a single photoacoustic spectroscopy detection module detects an evaluation concentration lower than the risk concentration, the location of the gas leak can be determined by combining the evaluation concentration obtained from an upstream adjacent photoacoustic spectroscopy detection module. The gas leak location can be precisely located based on the difference in evaluation concentrations between adjacent modules and the distance between adjacent photoacoustic spectroscopy detection modules, enabling rapid repair at the gas leak location, accelerating the repair response speed, and minimizing safety risks.

[0018] Furthermore, by detecting the actual pressure changes of the gas in the transport pipeline during the transport of the target gas, the evaluation rate of the gas pressure change is determined. If the gas pressure change does not indicate a gas leak, the relationship between the evaluation rate and the preset rate is used to determine if there is a risk of gas leakage. If a risk of gas leakage exists, the evaluation rate is used to calculate leakage risk parameters to comprehensively evaluate whether the gas transport is qualified in the absence of a clear gas leak. This avoids misjudgments caused by changes in the flow rate of the target gas during transport, which might lead to a misjudgment based on the evaluation rate alone. This allows for more accurate determination of the gas leak status, improving detection accuracy. It also allows for a comprehensive evaluation of the gas transport status based on leakage risk parameters, effectively predicting the location of gas leaks and enabling repairs before leaks occur to prevent them. Furthermore, it allows for timely closure of upstream valves in the leaking area after a leak occurs to prevent continued leakage and potential safety accidents.

[0019] Furthermore, by combining the evaluation decline rate with the risk decline rate that would be impossible under conditions where no gas leak has occurred during gas transportation, the potential for gas leakage in the transported gas can be determined. This avoids situations where the comprehensive evaluation of the gas transportation status based on leakage risk parameters is inaccurate even if no gas leak has occurred, due to severely unacceptable gas pressure fluctuations. This ensures that gas leaks are determined from multiple dimensions. Moreover, if a single pressure detection module detects an evaluation decline rate greater than the risk decline rate, the location of the gas leak can be determined by combining the evaluation decline rate detected by adjacent upstream pressure detection modules. The gas leak location can be precisely located based on the distance between adjacent evaluation decline rates and adjacent pressure detection modules, enabling rapid repair at the gas leak location, accelerating the repair response speed, and minimizing safety risks.

[0020] Furthermore, the invention determines the evaluation frequency band within the coverage area of ​​the current detection point by detecting the sound frequency band during the transport of the target gas. Based on the comparison between the evaluation frequency band of the current detection range and the preset frequency band, it determines whether there is an acoustic anomaly. When the acoustic energy is qualified, if there is an acoustic anomaly, it combines other parameters to comprehensively evaluate whether the gas transport is qualified when there is no clear gas leak. This avoids misjudging gas leaks due to external environmental noise or occasional detection errors during gas transport caused by judging whether there is a gas leak based on the evaluation frequency band. This allows for a more accurate determination of the gas leak status, improving detection accuracy. It can also comprehensively evaluate the gas transport status based on leakage risk parameters, effectively predicting the gas leak location so that the leak location can be repaired before a gas leak occurs, effectively preventing the gas leak from happening. It can also promptly close the upstream valve of the gas leak section after a gas leak occurs to prevent continuous gas leakage and the occurrence of safety accidents. Attached Figure Description

[0021] Figure 1 This is a diagram of the gas leak location system based on photoacoustic spectroscopy equipment and intelligent prediction according to the present invention; Figure 2 This is a flowchart illustrating the process of determining and locating gas leaks based on concentration evaluation according to the present invention. Figure 3 This is a flowchart illustrating the process of determining and locating gas leaks based on the rate of decrease in performance, as described in this invention. Figure 4 This is a flowchart illustrating the comprehensive determination and location of gas leaks in this invention. Detailed Implementation

[0022] To make the objectives and advantages of the present invention clearer, the present invention will be further described below with reference to embodiments; it should be understood that the specific embodiments described herein are merely for explaining the present invention and are not intended to limit the present invention.

[0023] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0024] Please see Figure 1 The following is a detailed description of an embodiment of a gas leak location system based on photoacoustic spectroscopy equipment and intelligent prediction for determining and locating gas leaks; This invention provides a gas leak location system based on photoacoustic spectroscopy equipment and intelligent prediction, comprising: A photoacoustic spectroscopy detection module is installed on the pipeline transporting the gas to acquire the photoacoustic signal of the target gas, determine the gas leakage range based on the judgment result of the evaluation concentration and the risk failure, and determine the entry into the risk warning process according to the relationship between the evaluation concentration and the preset concentration; wherein, the evaluation concentration is determined based on the analysis of gas composition based on photoacoustic signal. The photoacoustic spectroscopy detection module includes a photoacoustic spectrometer that acquires the photoacoustic signal of the target gas. The photoacoustic spectrometer analyzes the gas composition based on the photoacoustic signal to determine the target gas evaluation concentration. For example, if natural gas with a methane concentration of 90% is being transported, and the detected gas is methane, then if the methane concentration in the transported natural gas is below 80%, it is considered a methane leak with a risk of explosion. Air has been mixed into the natural gas, and the upstream valve must be shut off, and the incident must be handled as a safety accident. Therefore, in predicting whether a gas leak will occur, a methane concentration of 85% can be considered a risky state, indicating a potential safety hazard. Please see Figure 2 The diagram illustrates in detail the process of determining and locating gas leaks by evaluating concentration. Specifically, the process by which the photoacoustic spectroscopy detection module determines whether to enter the risk warning process includes, The evaluation concentration is compared with the preset concentration to determine the compliance of the component; in response to the determination that the component is unqualified, the first deviation value between the evaluation concentration and the preset concentration is determined to determine the leakage risk parameters.

[0025] If the evaluated concentration is greater than or equal to the preset concentration, the component is deemed qualified; if the evaluated concentration is less than the preset concentration, the component is deemed unqualified. The preset concentration here refers to the initial concentration of the target gas during transportation. For example, during the transportation of methane natural gas, assuming no leakage, the methane concentration typically varies by no more than ±1%. Therefore, for natural gas with a methane concentration of 90%, the preset concentration is set to 90%. When the concentration falls below 89%, it is considered an abnormal concentration. When the evaluated concentration is not lower than the preset concentration, it indicates normal gas transportation and no leakage of the target gas. When the evaluated concentration is lower than the preset concentration, it indicates a possible leakage during transportation, and other gases may have been mixed into the transported gas. The initial concentration of the target gas is then checked to further determine whether the fluctuation in the evaluated concentration is due to... If the initial concentration of the target gas changes, and if the initial concentration of the target gas is not lower than the preset concentration, then the fluctuation in the evaluated concentration is not due to the change in the initial concentration of the target gas. If the initial concentration of the target gas is lower than the preset concentration, then the initial concentration of the target gas is quickly adjusted to reach the preset concentration, and the risk warning process is initiated. During the risk warning process, the leakage risk parameters are calculated using the first deviation value between the evaluated concentration and the preset concentration and the concentration weight. By comprehensively evaluating the gas transportation status through the leakage risk parameters, the gas leakage location can be effectively predicted. Here, the first deviation value = preset concentration - evaluated concentration; at the same time, the accident determination process is initiated. This invention determines the concentration of the target gas at the current detection point by detecting photoacoustic signals in the transported target gas. Based on the relationship between the evaluated concentration at the current detection point and the preset concentration, in cases where there is no clear gas leak but the target gas concentration fluctuates, it comprehensively evaluates whether the gas transport is qualified under the condition that there is no clear gas leak. This avoids misjudging gas leaks due to initial concentration fluctuations of the target gas during transport, which might be caused by relying on the evaluated concentration to determine whether there is a gas leak. This allows for more accurate determination of the gas leak status and improves detection accuracy. Furthermore, it can comprehensively evaluate the gas transport status based on leakage risk parameters, effectively predict the location of gas leaks, and repair the leak before it occurs to effectively prevent gas leaks. It can also promptly close the upstream valve of the gas leak section after a gas leak occurs to prevent continuous gas leakage and potential safety accidents.

[0026] Specifically, the process of the photoacoustic spectroscopy detection module in determining the compliance of the risk includes comparing the evaluation concentration with the risk concentration to determine the compliance of the risk; in response to the determination that the risk is unqualified, determining to close the upstream pipeline valve, and determining the gas leak location based on the evaluation concentration of the upstream photoacoustic spectroscopy detection module.

[0027] The leakage assessment process is initiated, and the evaluated concentration is compared with the risk concentration to determine the risk compliance. At this point, the risk concentration is set at 85%. During the transportation of the target gas, if the evaluated concentration fails to meet the requirements for component compliance due to other factors, the evaluated concentration will not be lower than 85% in the absence of a serious leak. If it is lower than 85%, it indicates that a serious leak is inevitable. Therefore, the risk concentration of 85% is used as the calibration value for whether the target gas will leak during the transportation process. If the evaluated concentration is greater than or equal to the risk concentration, the risk is deemed acceptable. This indicates that there may be a leak in the concentration of the target gas in the transported gas. It could also be due to normal fluctuations caused by measurement errors or instantaneous changes caused by environmental interference. A comprehensive assessment is needed to determine whether a serious leak of the target gas has occurred. If the evaluated concentration is less than the risk concentration, the risk is deemed unqualified, indicating that a significant leak of the target gas has occurred and there is a major safety risk. The emergency response procedure must be activated immediately, the upstream valve must be closed, and the risk qualification of the target gas at the previous detection location must be determined. Maintenance personnel should be notified immediately to carry out repairs quickly, accelerate the repair response speed, and ensure that the emergency response is completed in a short time. This invention uses a single parameter to evaluate the concentration, combined with the boundary concentration (risk concentration) that would be impossible to occur during gas transportation without any leakage, to determine whether there is a possibility of leakage in the transported gas. This avoids situations where the overall gas transportation status is assessed based on leakage risk parameters, but the evaluated concentration is severely substandard, leading to inaccurate assessments. This ensures multi-dimensional gas leakage detection. Furthermore, if a single photoacoustic spectroscopy detection module detects an evaluated concentration lower than the risk concentration, the gas leak location is determined by combining the evaluated concentration obtained from an upstream adjacent photoacoustic spectroscopy detection module. The gas leak location is precisely located based on the difference in evaluated concentrations between adjacent modules and the distance between adjacent photoacoustic spectroscopy detection modules, enabling rapid repair at the leak location, accelerating the repair response speed, and minimizing safety risks.

[0028] A pressure detection module, corresponding to the photoacoustic spectroscopy detection module, is installed on the pipeline transporting the gas. It is used to obtain the actual pressure value of the target gas, determine the gas leakage range based on the evaluation drop rate to identify the seal failure, and determine the risk warning process based on the relationship that the evaluation drop rate is greater than the preset drop rate. The evaluation drop rate is determined based on continuous actual pressure values. The pressure detection module includes a gas pressure sensor, which acquires the actual pressure value of the target gas. The pressure detection module determines the pressure drop rate based on adjacent actual pressure values. Please see Figure 3 The diagram illustrates in detail the process of determining and locating gas leaks by evaluating the rate of descent. Specifically, the process by which the pressure detection module determines whether to enter the risk warning process includes: Compare and evaluate the rate of decrease with the preset rate of decrease to determine the compliance of the pressure change; In response to the determination that the pressure change is unqualified, a second deviation value between the evaluated drop rate and the preset drop rate is determined to determine the leakage risk parameters.

[0029] The pressure change is judged to be qualified by comparing the evaluated decrease rate with the preset decrease rate. If the evaluated decrease rate is less than or equal to the preset decrease rate, the pressure change is deemed qualified. If the evaluated decrease rate is greater than the preset decrease rate, the pressure change is deemed unqualified. During the pipeline transportation of the target gas, if the gas pressure inside the pipeline remains stable and there is no significant pressure drop without gas leakage, it indicates that the transportation process is well sealed. Therefore, the preset drop rate is set to 0.05 MPa / min, which allows the gas pressure to drop continuously for a certain period of time due to changes in the gas path during the gas transportation process. When the evaluated drop rate is less than or equal to the preset drop rate, and the pressure change is deemed acceptable, it indicates that the pipeline is in good sealing condition. Pressure fluctuations during the transportation of gas are normal and do not exceed the allowable range. When the evaluated pressure drop rate exceeds the preset pressure drop rate, indicating that the pressure change is unqualified, it means that there is pressure fluctuation in the gas inside the pipeline, and the pressure fluctuation exceeds the allowable range. The rate of pressure drop may be due to structural defects such as pipeline aging, mechanical damage, or loose connections, posing a risk of serious gas leakage. In this case, it is necessary to enter the risk warning process. During the risk warning process, the leakage risk parameters are calculated using the second deviation value between the evaluated pressure drop rate and the preset pressure drop rate, along with the pressure weight. Wherein, the second deviation value = evaluated pressure drop rate - preset pressure drop rate. This invention detects actual pressure changes in the transport pipeline during the transport of target gas, determines the evaluation rate of pressure drop, and judges the existence of gas leakage risk by comparing the evaluation rate with a preset rate when the gas pressure change does not indicate a gas leak. If a gas leakage risk exists, the evaluation rate is used to calculate leakage risk parameters to comprehensively evaluate whether the gas transport is qualified in the absence of a clear gas leak. This avoids misjudgments caused by changes in the target gas flow rate during transport, which might lead to a misjudgment based solely on the evaluation rate. This allows for more accurate determination of gas leakage status, improving detection accuracy. Furthermore, it can comprehensively evaluate the gas transport status based on leakage risk parameters, effectively predicting the location of gas leaks and allowing for pre-leak repairs to prevent leaks. Additionally, it can promptly close upstream valves in the leak area after a leak occurs to prevent continued leakage and potential safety accidents.

[0030] Specifically, the process by which the pressure detection module determines the seal qualification includes comparing the evaluation drop rate with the risk drop rate to determine the seal qualification; in response to determining that the seal is unqualified, determining to close the upstream pipeline valve, and determining the gas leak location by combining the evaluation drop rate of the upstream pressure detection module.

[0031] The leakage assessment process begins, and the gas pressure of a single parameter is analyzed to determine the sealing condition. In the absence of serious gas leakage, the evaluation rate should vary within a certain range and should not show a continuous downward trend. When the evaluation rate reaches a certain value, it indicates that the current transportation status has become abnormal. In the gas transportation process, the pressure drop rate threshold is generally set at 0.1 MPa / min to distinguish between normal pressure fluctuations and abnormal pressure drops that may cause leakage accidents. Therefore, the risk drop rate of 0.1 MPa / min is used as the calibration value for sealing qualification assessment. The sealing passability is determined by comparing the evaluation decline rate with the risk decline rate; if the evaluation decline rate is less than or equal to the risk decline rate, the sealing is considered passable; if the evaluation decline rate is greater than the risk decline rate, the sealing is considered failable. When the evaluation decline rate is less than or equal to the risk decline rate, it indicates that the sealing is qualified. This means that the pressure change in the pipeline is abnormal, but has not reached the point of leakage. The pressure change may be due to fluctuations caused by changes in the initial gas flow rate. At this time, monitor the changes in the initial gas flow rate to see if there is a sudden drop in the initial flow rate, which would cause the gas pressure to drop, so that the evaluation decline rate is greater than the preset decline rate. At this time, the risk warning process is initiated. When the evaluation decline rate is greater than the risk decline rate, the seal is deemed unqualified, indicating that the pipeline sealing performance can no longer meet the requirements for safe transportation. At this time, there is a serious gas leak, accompanied by a continuous and rapid drop in pressure, which may cause the concentration of flammable gas in the surrounding environment to rise to the lower explosive limit. In this case, the upstream valve should be closed immediately and the downstream gas should be transported quickly to avoid gas accumulation and causing a safety accident. Maintenance personnel should be notified immediately to carry out maintenance. The evaluation decline rate of adjacent pressure detection modules should be compared to quickly locate the problem, reduce maintenance time, and speed up the maintenance response.

[0032] The rate of decrease in pressure can be determined by comparing two adjacent actual pressure values ​​detected by a single pressure detection module, or by comparing actual pressure values ​​between adjacent pressure detection modules. When determined by comparing actual pressure values ​​between adjacent pressure detection modules, the rate of change of the pressure gradient between the two points needs to be calculated. When locating a gas leak, the rate of decrease in pressure determined by comparing two adjacent actual pressure values ​​detected by a single pressure detection module can be used to locate the leak based on the rate of decrease in pressure between two adjacent single pressure detection modules and the distance between them. The closer the leak is to the upstream pressure detection module, the greater the decrease in the rate of decrease in pressure downstream; conversely, the farther the leak is from the upstream pressure detection module, the smaller the change in the rate of decrease in pressure downstream. The rate of decrease in pressure determined by comparing actual pressure values ​​between adjacent pressure detection modules is based on the magnitude of the fluctuation in the actual pressure value, i.e., the magnitude of the rate of decrease itself. The closer the leak is to the upstream pressure detection module, the greater the rate of decrease in pressure between the two modules, and the more significant the change in the pressure gradient; conversely, the farther the leak is from the upstream pressure detection module, the smaller the rate of decrease in pressure between the two modules, and the less significant the change in the pressure gradient. This invention uses a single parameter to evaluate the rate of decline, combined with a risk decline rate that would be impossible in the absence of gas leakage during gas transportation, to determine whether there is a possibility of gas leakage in the transported gas. This avoids situations where the comprehensive evaluation of the gas transportation status based on leakage risk parameters is inaccurate even if there is no gas leakage, but the gas pressure fluctuation is already severely substandard. This ensures that gas leakage is determined from multiple dimensions. Furthermore, if a single pressure detection module detects an evaluation decline rate greater than the risk decline rate, the gas leak location is determined by combining the evaluation decline rate detected by an upstream adjacent pressure detection module. The gas leak location is precisely located based on the distance between adjacent evaluation decline rates and adjacent pressure detection modules, enabling rapid repair at the gas leak location, accelerating the repair response speed, and minimizing safety risks.

[0033] A low-frequency acoustic detection module is installed on the pipeline transporting gas, distributed on both sides of the photoacoustic spectroscopy detection module. It is used to acquire the sound frequency band of the transporting gas pipeline, determine the gas leakage range based on the judgment result of the acoustic energy not meeting the standard based on the evaluation frequency band, and determine the risk warning process based on the relationship between the evaluation frequency band and the preset frequency band. The evaluation frequency band is determined based on the acoustic frequency band. The low-frequency acoustic detection module acquires the sound frequency band of the transport gas pipeline, compares and evaluates the frequency band with the preset frequency band, and determines the sound qualification. The distance between each low-frequency acoustic detection module and the nearest photoacoustic spectroscopy detection module is 1 / 4 of the distance between two adjacent photoacoustic spectroscopy detection modules, thereby ensuring that the low-frequency acoustic detection modules on the gas transport pipeline can be linearly and uniformly distributed and cover the entire pipeline area for acoustic monitoring. When the gas is being transported normally without any leakage, the low-frequency acoustic detection module acquires a sound frequency range of 0-100Hz. At this time, the airflow in the pipeline is stable, and the acoustic signal does not have significant fluctuation characteristics. When a minor leak occurs, the sound wave frequency caused by turbulence at the leak point is concentrated in the range of 100-500 Hz. Therefore, the preset frequency range is set to 150Hz. Specifically, the process by which the low-frequency acoustic detection module determines whether to enter the risk warning process includes: The evaluation frequency band is compared with the preset frequency band to determine the sound quality. In response to the determination that the sound is unqualified, the third deviation value between the evaluation frequency band and the preset frequency band is determined to determine the leakage risk parameters.

[0034] If the evaluation frequency band is less than or equal to the preset frequency band, the sound is deemed acceptable; if the evaluation frequency band is greater than the preset frequency band, the sound is deemed unacceptable. When the evaluation frequency band is less than or equal to the preset frequency band, the sound is deemed qualified, indicating that there is no significant turbulence disturbance in the pipeline, the acoustic characteristics are within the normal range, and the gas transportation is in a safe and stable state. When the evaluation frequency band is greater than the preset frequency band, the sound is deemed unqualified, indicating that there is an abnormality in the sound frequency band acquired by the low-frequency acoustic detection module. At this time, the evaluation frequency band may be due to data fluctuations caused by external noise or gas leakage. Therefore, it is necessary to detect changes in gas flow rate. If the changes in gas flow rate are correlated with changes in the evaluation frequency band, the gas flow rate should be adjusted to stabilize before further determining whether the sound judgment is qualified. At the same time, the risk warning process is initiated. During the risk warning process, the leakage risk parameters are calculated by using the third deviation value between the evaluation frequency band and the preset frequency band and the sound weight. The third deviation value = evaluation frequency band - preset frequency band. This invention determines the evaluation frequency band within the coverage area of ​​the current detection point by detecting the sound frequency band during the transport of the target gas. Based on the comparison between the evaluation frequency band of the current detection range and the preset frequency band, it determines whether there is an acoustic anomaly. If the acoustic energy is acceptable, but an acoustic anomaly is present, it combines other parameters to comprehensively evaluate whether the gas transport is qualified in the absence of a clear gas leak. This avoids misjudging gas leaks due to environmental noise or occasional detection errors during gas transport, which might arise from judging gas leaks based on the evaluation frequency band. This allows for more accurate determination of gas leak status, improving detection accuracy. Furthermore, it can comprehensively evaluate the gas transport status based on leakage risk parameters, effectively predicting the location of gas leaks and allowing for repairs before leaks occur, effectively preventing gas leaks. It can also promptly close upstream valves in the gas leak area after a leak occurs to prevent continued gas leakage and potential safety accidents.

[0035] Specifically, the process by which the low-frequency acoustic detection module determines the acoustic energy qualification includes: By comparing the evaluation frequency band with the risk frequency band, the acoustic energy is deemed acceptable; in response to the determination that the acoustic energy is unacceptable, the upstream pipeline valve is shut off, and the gas leak location is determined by combining the evaluation frequency band of the upstream low-frequency acoustic detection module.

[0036] The degree of sound non-compliance is further determined by evaluating the frequency band with a single parameter. The evaluation frequency band is compared with the risk frequency band to determine the acoustic energy compliance. The risk frequency band is 100-500Hz. Since there is the possibility of external noise interference in the low frequency part of 100-500Hz, 300Hz is selected as the value of the risk frequency band as the threshold for determining the acoustic energy compliance. If the evaluation frequency band is less than or equal to the risk frequency band, the acoustic energy is deemed to be qualified; if the evaluation frequency band is greater than the risk frequency band, the acoustic energy is deemed to be unqualified. When the evaluation frequency band is less than or equal to the risk frequency band, the acoustic energy is deemed to be qualified. This indicates that there is a possibility of leakage in the pipeline transporting the gas. There may also be fluctuations in the evaluation frequency band caused by various factors such as external noise or changes in gas flow. In this case, a risk warning process should be initiated. When the evaluation frequency band is greater than the risk frequency band, and the acoustic energy is deemed unqualified, it indicates that there is a huge spillover of acoustic energy, suggesting that the leak point has generated significant turbulent disturbances and that the acoustic energy is being released in a concentrated manner, exhibiting high-confidence leak characteristics. In this case, the upstream valve should be immediately closed, and a rapid alarm should be issued to notify maintenance personnel. The location should be analyzed using adjacent low-frequency acoustic detection modules. After the sound wave reaches the adjacent low-frequency acoustic detection module, the magnitude of the evaluation frequency band obtained by the adjacent low-frequency acoustic detection module is used to predict the location of the leak point, thereby achieving the purpose of rapid location.

[0037] This invention uses a single-parameter evaluation frequency band combined with a risk frequency band indicating potential gas leakage during gas transportation to determine whether a gas leak is possible. This avoids situations where the comprehensive evaluation of gas transportation status based on leakage risk parameters fails to identify a leak even if the evaluation frequency band is severely substandard, leading to inaccurate comprehensive evaluations of gas transportation status. This ensures multi-dimensional gas leak detection. Furthermore, if a gas leak is detected by a single-parameter evaluation frequency band, the leak location can be precisely pinpointed by combining evaluation frequency bands detected by adjacent upstream and downstream low-frequency acoustic detection modules. The leak location can be determined by time difference or abrupt changes in the evaluation frequency band, enabling rapid repair at the leak location, accelerating repair response speed, and minimizing safety risks.

[0038] The comprehensive evaluation module determines the gas leakage range based on the leakage risk parameters to identify unqualified gas transportation conditions. It then re-determines the leakage risk parameters based on the relationship between the leakage risk parameters and the early warning leakage coefficient. The time interval for obtaining the leakage risk parameters is determined based on the insufficient value of the leakage risk parameters relative to the standard leakage parameters. The early warning leakage coefficient is determined based on the leakage risk parameters and the standard leakage parameters, and the leakage risk parameters are determined based on the evaluation concentration, the evaluation decline rate, and the evaluation frequency band.

[0039] Based on the first deviation value, the second deviation value, the third deviation value, the concentration weight, the pressure weight, and the sound weight, the leakage risk parameters are determined, and the leakage risk parameters are compared with the standard leakage parameters to determine the qualification of gas transportation. Let the leakage risk parameter be S, and its calculation formula is: S = Ki × (First Deviation Value / Preset Concentration) × Wi + Kj × (Second Deviation Value / Decrease Rate) × Wj + Kf × (Third Deviation Value / Preset Frequency Band) × Wf, where Ki, Kj, and Kf are correction coefficients to ensure that the first, second, and third deviation values ​​are all of the same order of magnitude after correction. Wi, Wj, and Wf are the concentration weight, pressure weight, and sound weight, respectively. In the process of predicting gas leaks, evaluating concentration best reflects the characteristics of gas leaks, followed by evaluating the decrease rate, and lastly evaluating the frequency band. Therefore, in the initial calculation of the leak risk parameter S, Wi = 0.5, Wj = 0.35, and Wf = 0.15 are set to reflect the various factors. The primary and secondary relationships of parameters in leak identification are considered. While correcting the first deviation value / preset concentration, the second deviation value / decline rate, and the third deviation value / preset frequency band using Ki, Kj, and Kf to ensure their magnitudes are within the same range, it is crucial to ensure that the evaluation concentration and concentration weight fully respond to the impact on leak risk parameters. Simultaneously, it is essential to ensure the evaluation decline rate and pressure weight are effective in determining leak risk parameters, avoiding multiple parameters changing dynamically and altering the actual meaning of the leak risk parameters. Therefore, the stability of leak risk parameters is ensured through the evaluation decline rate and pressure weight, and the response speed of leak risk parameters is increased by adjusting the evaluation concentration. Thus, Ki is set to 10, Kj to 1, and Kf to 5. For example, when the evaluation concentration is 88%, the evaluation decrease rate is 0.08 MPa / min, and the evaluation frequency band is 160 Hz, then S = 10 × (0.02 / 0.9) × 0.5 + 1 × (0.03 / 0.05) × 0.35 + 5 × (10 / 150) × 0.15 = 0.371; The standard leakage parameter was obtained through statistical analysis of historical leakage data and actual maintenance records, and was set as Sz=0.3; Please see Figure 4 The process for determining the qualification of gas transportation is shown in detail. Specifically, the process by which the comprehensive evaluation module determines the qualification of gas transportation includes: By comparing the leakage risk parameters with the standard leakage parameters, the qualification of gas transportation is determined; in response to the determination that the gas transportation is unqualified, the upstream pipeline valve is closed, and the gas leakage location is determined based on the insufficient value.

[0040] If S≤Sz, the gas transport is deemed qualified; if S>Sz, the gas transport is deemed unqualified. When S≤Sz, it indicates that there is no leakage in the gas transportation process, but there is a risk of leakage, which requires close monitoring. When S > Sz, it indicates that a leak has occurred during gas transportation. An alarm should be issued immediately to notify maintenance personnel to carry out repairs. The leak risk parameters obtained by the installation points of adjacent photoacoustic spectroscopy detection modules are compared. The closer the leak point is to the leak point, the greater the leak risk parameter is, thereby quickly and accurately locating the leak point and speeding up the repair response. This invention employs a comprehensive evaluation of gas transportation status based on leakage risk parameters determined by evaluation concentration, evaluation decline rate, and evaluation frequency band. This analysis combines multiple directions and dimensions to assess gas transportation status even when a single parameter does not explicitly indicate a gas leak. It can accurately determine gas leak conditions and, even in the absence of a leak, predict the likelihood of a leak based on the difference between the leakage risk parameters and standard leakage parameters, enabling early warning. This multi-parameter coupled analysis effectively improves the sensitivity and accuracy of gas leak identification, avoiding safety hazards caused by misjudgments based on a single parameter. It can determine gas leak conditions independently or jointly using multiple single parameters, ensuring a comprehensive and accurate prediction of gas transportation status. This allows for a thorough understanding of the dynamic changes in risks during gas transportation and provides a scientific basis for handling gas leaks.

[0041] Specifically, the process by which the comprehensive evaluation module redetermines the leakage risk parameters includes, By comparing the leakage risk parameters with the early warning leakage parameters, and in response to the leakage risk parameters being greater than the early warning leakage parameters, the leakage risk parameters are re-determined to re-evaluate the gas transportation qualification.

[0042] When S≤Sz, in order to increase the reliability of detection, a warning leakage parameter is set according to the insufficient value of S relative to Sz. Let the warning leakage parameter be Sq, Sq=(Sz-S). Sq can also be set to different values ​​according to different detection requirements, for example Sq=(Sz-S / 2). When S≥Sq, the values ​​of Wi, Wj, and Wf are redefined to redetermine S, thereby increasing the accuracy of detection. For example, when the evaluation concentration is 89%, the evaluation decrease rate is 0.06 MPa / min, and the evaluation frequency band is 180 Hz, S = 10 × (0.01 / 0.9) × 0.5 + 1 × (0.01 / 0.05) × 0.35 + 5 × (30 / 150) × 0.15 = 0.235. At this point, S < Sz and S > Sq, indicating a potential leakage risk in gas transportation. The values ​​of Wi, Wj, and Wf are then redefined to re-determine S. During the re-determination of Wi, Wj, and Wf, the parameters with the largest deviations from the first, second, and third deviation values ​​are weighted accordingly. At this point, the deviation between the evaluation degradation rate and the evaluation frequency band is the largest. Therefore, adjustments are made based on the evaluation degradation rate and the evaluation frequency band with the largest weights. Wj is increased to 0.45, and Wi is correspondingly decreased to 0.4, while Wf remains unchanged. The redefined S is then 10 × (0.01 / 0.9) × 0.4 + 1 × (0.01 / 0.05) × 0.45 + 5 × (30 / 150) × 0.15 = 0.265. At this point, S is still less than Sz but close to Sz. Subsequent determinations of S are based on the redefined Wi, Wj, and Wf to improve detection sensitivity and judgment accuracy.

[0043] This invention first determines a leakage risk parameter based on a preset weighted single parameter to quickly determine whether a gas leak has occurred. If no leak is confirmed, an early warning leakage parameter and a dynamic weight adjustment mechanism are introduced to achieve a refined assessment of potential leakage risks. When the leakage risk parameter is greater than or equal to the early warning leakage parameter, the leakage risk parameter is redefined and combined with a standard leakage parameter to determine whether a gas leak has occurred. Simultaneously, the early warning leakage parameter is dynamically adjusted. When the leakage risk parameter is low, indicating a low probability of gas leakage, the early warning leakage parameter is increased accordingly to reduce the probability of false alarms. When the leakage risk parameter is close to the standard leakage parameter, the early warning leakage parameter is promptly decreased to improve detection sensitivity, ensuring that no potential leakage risk is missed. This increases the accuracy of predicting gas leaks and the precision of locating the leak location after a leak is confirmed.

[0044] Specifically, the time interval for obtaining the leakage risk parameters is positively correlated with the deficiency value; the smaller the deficiency value, the shorter the time interval for obtaining the leakage risk parameters. For example, when S=0.05, the time interval for obtaining the leakage risk parameters is 10 minutes; when S=0.1, the time interval for obtaining the leakage risk parameters is 8 minutes; when S=0.2, the time interval for obtaining the leakage risk parameters is 4 minutes; and when S=0.25, the time interval for obtaining the leakage risk parameters is 2 minutes.

[0045] This enables rapid response to obtain monitoring leak risk parameters, quickly determine the gas transportation situation, and determine whether a leak has occurred during transportation. Through multi-point collaborative monitoring, the location of the leak point can be quickly located to meet the requirements for rapid response to gas leaks and repair.

[0046] The technical solution of the present invention has been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the scope of protection of the present invention.

Claims

1. A gas leak location system based on photoacoustic spectroscopy equipment and intelligent prediction, characterized in that, include, A photoacoustic spectroscopy detection module is installed on the pipeline transporting the gas to acquire the photoacoustic signal of the target gas, determine the gas leakage range based on the judgment result of the evaluation concentration and the risk failure, and determine the entry into the risk warning process according to the relationship between the evaluation concentration and the preset concentration; wherein, the evaluation concentration is determined based on the analysis of gas composition based on photoacoustic signal. A pressure detection module, corresponding to the photoacoustic spectroscopy detection module, is installed on the pipeline transporting the gas. It is used to obtain the actual pressure value of the target gas, determine the gas leakage range based on the evaluation drop rate to identify the seal failure, and determine the risk warning process based on the relationship that the evaluation drop rate is greater than the preset drop rate. The evaluation drop rate is determined based on continuous actual pressure values. A low-frequency acoustic detection module is installed on the pipeline transporting gas, distributed on both sides of the photoacoustic spectroscopy detection module. It is used to acquire the sound frequency band of the transporting gas pipeline, determine the gas leakage range based on the judgment result of the acoustic energy not meeting the evaluation frequency band, and determine the risk warning process based on the relationship between the evaluation frequency band and the preset frequency band. The evaluation frequency band is determined based on the acoustic frequency band. The comprehensive evaluation module determines the gas leakage range based on the leakage risk parameters to identify unqualified gas transportation conditions. It then re-determines the leakage risk parameters based on the relationship between the leakage risk parameters and the early warning leakage coefficient. The time interval for obtaining the leakage risk parameters is determined based on the insufficient value of the leakage risk parameters relative to the standard leakage parameters. The early warning leakage coefficient is determined based on the leakage risk parameters and the standard leakage parameters, and the leakage risk parameters are determined based on the evaluation concentration, the evaluation decline rate, and the evaluation frequency band.

2. The gas leak location system based on photoacoustic spectroscopy equipment and intelligent prediction according to claim 1, characterized in that, The process by which the photoacoustic spectroscopy detection module determines the risk compliance includes: Compare and evaluate the concentration with the risk concentration to determine the risk compliance. In response to the risk assessment being deemed unacceptable, the upstream pipeline valve is shut off, and the location of the gas leak is determined based on the evaluation concentration from the upstream photoacoustic spectroscopy detection module.

3. The gas leak location system based on photoacoustic spectroscopy equipment and intelligent prediction according to claim 1, characterized in that, The process by which the photoacoustic spectroscopy detection module determines whether to enter the risk warning process includes the following steps. Compare and evaluate the concentration with the preset concentration to determine the compliance of the components; In response to the determination that a component is unqualified, a first deviation value between the evaluated concentration and the preset concentration is determined to determine the leakage risk parameter.

4. The gas leak location system based on photoacoustic spectroscopy equipment and intelligent prediction according to claim 1, characterized in that, The process by which the pressure detection module determines the seal's compliance includes: Compare and evaluate the rate of decrease in risk with the rate of decrease in risk to determine the seal's compliance. In response to the determination that the seal is unqualified, the upstream pipeline valve is shut off, and the gas leak location is determined by combining the evaluation drop rate of the upstream pressure detection module.

5. The gas leak location system based on photoacoustic spectroscopy equipment and intelligent prediction according to claim 1, characterized in that, The process by which the pressure detection module determines whether to enter the risk warning process includes the following steps. Compare and evaluate the rate of decrease with the preset rate of decrease to determine the compliance of the pressure change; In response to the determination that the pressure change is unqualified, a second deviation value between the evaluated drop rate and the preset drop rate is determined to determine the leakage risk parameters.

6. The gas leak location system based on photoacoustic spectroscopy equipment and intelligent prediction according to claim 1, characterized in that, The process by which the low-frequency acoustic detection module determines the acoustic energy qualification includes: Compare and evaluate the frequency band with the risk frequency band to determine the suitability of the acoustic energy. In response to the determination that the acoustic energy is unqualified, the upstream pipeline valve is closed, and the gas leak location is determined by combining the evaluation frequency band of the upstream low-frequency acoustic detection module.

7. The gas leak location system based on photoacoustic spectroscopy equipment and intelligent prediction according to claim 1, characterized in that, The process by which the low-frequency acoustic detection module determines whether to enter the risk warning process includes the following steps. Compare the evaluation frequency band with the preset frequency band to determine the sound quality. In response to the determination that the sound is unqualified, a third deviation value between the evaluation frequency band and the preset frequency band is determined to determine the leakage risk parameters.

8. The gas leak location system based on photoacoustic spectroscopy equipment and intelligent prediction according to claim 1, characterized in that, The process by which the comprehensive evaluation module determines the qualification of gas transportation includes: The gas transportation qualification is determined by comparing leakage risk parameters with standard leakage parameters. In response to the determination that the gas transport is substandard, the upstream pipeline valve is shut off, and the gas leak location is determined based on the insufficient value.

9. The gas leak location system based on photoacoustic spectroscopy equipment and intelligent prediction according to claim 1, characterized in that, The process by which the comprehensive evaluation module redetermines the leakage risk parameters includes: By comparing the leakage risk parameters with the early warning leakage parameters, and in response to the leakage risk parameters being greater than the early warning leakage parameters, the leakage risk parameters are re-determined to re-evaluate the gas transportation qualification.

10. The gas leak location system based on photoacoustic spectroscopy equipment and intelligent prediction according to claim 1, characterized in that, The time interval for obtaining the leakage risk parameters is positively correlated with the insufficient value.

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