Pipeline leakage point detection method and system based on gas tracing

Abstract

The invention relates to the technical field of pipeline detection, in particular to a pipeline leakage point detection method and system based on gas tracing. Firstly, composite tracer gas is injected into a to-be-detected pipeline through a gas injection device; the sensor modules distributed in the to-be-detected area collect data parameters in real time, the control host judges whether the data parameters collected at the position where the current sensor module is located are interference data or not based on the gas concentration value, and the interference data are removed in time; the control host marks the data parameters of the non-interference data as effective parameters, and fuses the real-time wind speed value and the real-time temperature value in the effective parameters to correct the effective parameters; and then the leakage position of the to-be-detected pipeline is determined based on the corrected effective parameters. The diffusion error is corrected by fusing the environmental parameters of the temperature and the wind speed, the anti-interference capability is higher, and the precision is higher.

Description

Technical Field

[0001] This invention relates to the field of pipeline inspection technology, specifically to a pipeline leak detection method and system based on gas tracing. Background Technology

[0002] With the development of science and technology, the number of underground pipelines (such as water pipes) is increasing. When leaks occur in these numerous and complex underground pipelines, it is crucial to locate the leak points promptly to prevent water loss. Currently, microphones are used to collect sound signals from the ground in real time, and personnel listen to these signals to determine the location of the leak. This method of leak detection is relatively primitive, with limited accuracy in leak location and difficulty in visually identifying the exact location of the leak. Therefore, there is an urgent need for a more accurate and intuitive technical solution for locating leaks in underground pipelines. Summary of the Invention

[0003] The main objective of this invention is to provide a gas tracing-based pipeline leak detection method and system, aiming to solve the current urgent need for a technical solution that can more accurately and intuitively locate underground pipeline leaks.

[0004] The technical solution proposed in this invention is as follows: A gas tracer-based pipeline leak detection method is applied to a gas tracer-based pipeline leak detection system; the system includes a gas injection device, a sensor module, and a control host; the sensor module and the control host are communicatively connected; the method includes: The gas injection device injects composite tracer gas into the inlet end of the pipeline to be tested; Multiple sensor modules are manually deployed on the ground in the area to be tested. The pipeline to be tested is located underground in the rectangular area. The multiple sensor modules are distributed in a matrix within the area to be tested. Each sensor module includes a gas sensor, a wind speed sensor, and a temperature sensor. The sensor module collects data parameters in real time and sends them to the control host. The data parameters include gas concentration value, real-time wind speed value, and real-time temperature value. The control host determines whether the data parameters collected by the current sensor module at its current location are interference data based on the gas concentration value; If the data parameter is interference data, the control host will mark the data parameter as invalid and discard it; If the data parameter is not interfering data, the control host will mark the data parameter as a valid parameter, and integrate the real-time wind speed value and real-time temperature value in the valid parameter to correct the valid parameter; The control host determines the location of the leak in the pipeline under test based on the corrected effective parameters.

[0005] Preferably, the gas injection device includes a gas storage tank, a pressure sensor, a flow sensor, and a control valve; the gas injection device injects composite tracer gas into the inlet end of the pipeline under test, including: The first tracer gas and the second tracer gas are mixed in a preset ratio to form a composite tracer gas, and the composite tracer gas is filled into a gas storage tank. Connect the outlet of the gas storage tank to the inlet of the pipeline under test, close the outlet of the pipeline under test, and start the control valve to fill the pipeline under test with composite tracer gas.

[0006] Preferably, the first tracer gas is SF6; the second tracer gas is C7H5F3.

[0007] Preferably, the gas injection device injects the composite tracer gas into the inlet end of the pipe to be tested, and then includes: The pressure sensor acquires the real-time pressure value of the pipeline under test and sends it to the control host. The flow sensor acquires the real-time flow value of the pipe under test and sends it to the control host; The control host calculates the injection flow rate of the composite tracer gas based on real-time pressure and flow rates, and adjusts the injection flow rate through a control valve to keep the concentration of the composite tracer gas in the pipeline under test within a preset range.

[0008] Preferably, the gas sensor includes a first gas sensor and a second gas sensor; the sensor module collects data parameters in real time and sends them to the control host, including: The first gas sensor detects the concentration value of the first tracer gas in real time and marks it as the first gas concentration value, which is then sent to the control host. The second gas sensor detects the concentration value of the second tracer gas in real time and marks it as the second gas concentration value, which is then sent to the control host. The control host marks the first gas concentration value and the second gas concentration value as gas concentration values; The control host determines whether the data parameters collected by the current sensor module at its location are interference data based on the gas concentration value, including: The control host determines whether the ratio of the first gas concentration value and the second gas concentration value is greater than a first preset value or less than a second preset value, wherein the second preset value is less than the first preset value; If so, the control host determines that the data parameters collected by the current sensor module at its location are interference data; If not, the control host determines that the data parameters collected by the current sensor module are not interference data.

[0009] Preferably, if the data parameters are not interfering data, the control host marks the data parameters as valid parameters, and integrates the real-time wind speed value and real-time temperature value from the valid parameters to correct the valid parameters, including: The control host establishes an effective parameter correction model: (1), In the formula, This is the corrected gas concentration value. These are the measured gas concentration values; The standard temperature is 293.15 K; T is the measured temperature of the area to be measured, in K. Standard wind speed, in m / s; The measured wind speed in the area to be measured is expressed in m / s. The control host corrects the first gas concentration value and the second gas concentration value based on the effective parameter correction model.

[0010] Preferably, the control host determines the leak location of the pipeline under test based on the corrected effective parameters, including: The control host constructs multiple sets of axial gas concentration gradient curves of the pipeline based on the corrected effective parameters, and uses a Gaussian fitting algorithm to fit the gas concentration gradient curves. The gas concentration in the gas concentration gradient curve is the first gas concentration. Each row of sensor modules corresponds to one gas concentration gradient curve, and the total number of gas concentration gradient curves is consistent with the total number of columns of sensor modules. The control host determines the position of the sensing unit corresponding to the peak value in the gas concentration gradient curve, and then establishes a leak point diffusion model by combining the data parameters of multiple adjacent sensor modules. By solving the zero point of the second derivative of the leak point diffusion model, the coordinates of the leak point in the pipeline under test can be located.

[0011] Preferably, the control host determines the position of the sensing unit corresponding to the peak value in the gas concentration gradient curve, and then, in conjunction with the data parameters of multiple adjacent sensor modules, establishes a leak point diffusion model. By solving for the zero point of the second derivative of the leak point diffusion model, the coordinates of the leak point in the pipeline under test are located, including: The control host uses the row of sensor modules corresponding to the gas concentration gradient curve with the largest peak among multiple gas concentration gradient curves as a reference line, and the position of the sensor module corresponding to the largest peak point on the reference line is set as follows: ; The control host establishes a leak propagation model: (2), In the formula, The calibration gas concentration at point x on the reference line in the area to be measured; The first gas concentration collected by the sensor module corresponding to the maximum peak point; The diffusion coefficient is calculated using the following formula: (3), The control host will The x-position point corresponding to the maximum value is taken as the coordinate of the leak point in the pipe under test.

[0012] This invention also proposes a pipeline leak detection system based on gas tracing, which applies a pipeline leak detection method based on gas tracing; the system includes a gas injection device, a sensor module, and a control host; the sensor module and the control host are communicatively connected.

[0013] The above technical solution can achieve the following beneficial effects: This invention proposes a gas tracer-based pipeline leak detection method, providing a more accurate and intuitive technical solution for locating leaks in underground pipelines. First, a composite tracer gas is injected into the pipeline under test using a gas injection device. Sensor modules deployed within the test area collect data parameters in real time. The control host determines whether the data parameters collected by the current sensor module location are interference data based on the gas concentration value and promptly removes interference data. The control host marks the non-interference data parameters as valid parameters and integrates real-time wind speed and real-time temperature values ​​from the valid parameters to correct them. Then, the leak location in the pipeline under test is determined based on the corrected valid parameters. This application corrects diffusion errors by integrating environmental parameters such as temperature and wind speed, resulting in stronger anti-interference capabilities and higher accuracy. Attached Figure Description

[0014] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0015] Figure 1 This is a flowchart illustrating the first embodiment of a pipeline leak detection method based on gas tracing proposed in this invention. Detailed Implementation

[0016] It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of the invention.

[0017] This invention proposes a method and system for detecting pipeline leaks based on gas tracing.

[0018] As attached Figure 1As shown, in the first embodiment of the gas tracer-based pipeline leak detection method proposed in this invention, this gas tracer-based pipeline leak detection method is applied to a gas tracer-based pipeline leak detection system; the system includes a gas injection device, a sensor module, and a control host; the sensor module and the control host are communicatively connected; this embodiment includes the following steps: Step S110: The gas injection device injects the composite tracer gas into the inlet end of the pipeline to be tested.

[0019] Specifically, the outlet end of the pipe to be tested needs to be sealed.

[0020] Step S120: Multiple sensor modules are manually deployed on the ground in the area to be tested. The pipeline to be tested is located underground in the area to be tested. The area to be tested is rectangular. The multiple sensor modules are distributed in a matrix within the area to be tested. Each sensor module includes a gas sensor, a wind speed sensor, and a temperature sensor.

[0021] Step S130: The sensor module collects data parameters in real time and sends them to the control host. The data parameters include gas concentration value, real-time wind speed value and real-time temperature value.

[0022] Step S140: The control host determines whether the data parameters collected by the current sensor module at its current location are interference data based on the gas concentration value.

[0023] Step S150: If the data parameter is interference data, the control host will mark the data parameter as invalid and discard it.

[0024] Step S160: If the data parameter is not interfering data, the control host marks the data parameter as a valid parameter, and merges the real-time wind speed value and real-time temperature value in the valid parameter to correct the valid parameter.

[0025] Step S170: The control host determines the leak location of the pipeline under test based on the corrected effective parameters.

[0026] This invention proposes a gas tracer-based pipeline leak detection method, providing a more accurate and intuitive technical solution for locating leaks in underground pipelines. First, a composite tracer gas is injected into the pipeline under test using a gas injection device. Sensor modules deployed within the test area collect data parameters in real time. The control host determines whether the data parameters collected by the current sensor module location are interference data based on the gas concentration value and promptly removes interference data. The control host marks the non-interference data parameters as valid parameters and integrates real-time wind speed and real-time temperature values ​​from the valid parameters to correct them. Then, the leak location in the pipeline under test is determined based on the corrected valid parameters. This application corrects diffusion errors by integrating environmental parameters such as temperature and wind speed, resulting in stronger anti-interference capabilities and higher accuracy.

[0027] In a second embodiment of a pipeline leak detection method based on gas tracing proposed in this invention, based on the first embodiment, the gas injection device includes a gas storage tank, a pressure sensor, a flow sensor, and a control valve; step S110 includes the following steps: Step S210: Mix the first tracer gas and the second tracer gas in a preset ratio (e.g., 1:5) to form a composite tracer gas, and fill the composite tracer gas into a gas storage tank. Specifically, the first tracer gas is used to identify the core leak signal, and the second tracer gas is used for anti-interference verification.

[0028] Step S220: Connect the outlet end of the gas storage tank to the inlet end of the pipeline to be tested, and close the outlet end of the pipeline to be tested. Start the control valve to fill the pipeline to be tested with composite tracer gas.

[0029] Specifically, a "primary-secondary" composite tracer system is constructed to facilitate subsequent verification of concentration ratios to eliminate environmental interference.

[0030] In the third embodiment of the pipeline leak detection method based on gas tracer proposed in this invention, based on the second embodiment, the first tracer gas is SF6; the second tracer gas is C7H5F3.

[0031] Specifically, the first tracer gas is SF6, which is chemically inert (does not react with the pipeline medium), has extremely low natural environmental content (<0.01ppb), and high detection sensitivity (can detect a concentration of 0.001ppb), and is used to identify the core leak point signal; the second tracer gas is C7H5F3: it is volatile and stable, has the same diffusion characteristics as SF6, and has an environmental background value of <0.01ppb, and is used to form a fixed ratio with the main tracer to verify the authenticity of the signal (excluding single interfering gases).

[0032] In the fourth embodiment of the pipeline leak detection method based on gas tracing proposed in this invention, based on the second embodiment, step S110 is followed by the following steps: Step S410: The pressure sensor acquires the real-time pressure value of the pipeline under test and sends it to the control host.

[0033] Step S420: The flow sensor acquires the real-time flow value of the pipe under test and sends it to the control host.

[0034] Step S430: The control host calculates the injection flow rate of the composite tracer gas based on the real-time pressure value and the real-time flow rate value, and adjusts the injection flow rate through the control valve to keep the concentration of the composite tracer gas in the pipeline under test within a preset range (e.g., 5-10 ppb).

[0035] Specifically, by maintaining the concentration of the composite tracer gas in the pipeline under test within a preset range, both detection sensitivity and reagent economy can be achieved.

[0036] In the fifth embodiment of the pipeline leak detection method based on gas tracing proposed in this invention, based on the second embodiment, the gas sensor includes a first gas sensor and a second gas sensor; step S130 includes the following steps: Step S510: The first gas sensor detects the concentration value of the first tracer gas in real time, marks it as the first gas concentration value, and sends it to the control host.

[0037] Step S520: The second gas sensor detects the concentration value of the second tracer gas in real time and marks it as the second gas concentration value and sends it to the control host.

[0038] Step S530: The control host marks the first gas concentration value and the second gas concentration value as gas concentration values.

[0039] Step S140 includes the following steps: Step S540: The control host determines whether the ratio of the first gas concentration value and the second gas concentration value is greater than a first preset value or less than a second preset value, wherein the second preset value is less than the first preset value.

[0040] Specifically, under normal circumstances, the ratio of the first gas concentration value and the second gas concentration value should be close to the above-mentioned preset ratio (e.g., 1:5). Therefore, when the ratio of the first gas concentration value and the second gas concentration value is greater than the first preset value (0.3) or less than the second preset value (0.1), it proves that the ratio of the first gas concentration value and the second gas concentration value is abnormal. Therefore, the data parameters collected at the current location of the sensor module are treated as interference data to avoid misjudgment and ensure the validity of the data parameters.

[0041] If so, proceed to step S550: The control host determines that the data parameters collected by the current sensor module are interference data.

[0042] If not, proceed to step S560: The control host determines that the data parameters collected by the current sensor module are not interference data.

[0043] In the sixth embodiment of the pipeline leak detection method based on gas tracing proposed in this invention, based on the fifth embodiment, step S160 includes the following steps: Step S610: The control host establishes an effective parameter correction model: (1), In the formula, This is the corrected gas concentration value. These are the measured gas concentration values; The standard temperature is 293.15 K; T is the measured temperature of the area to be measured, in K. Standard wind speed, in m / s; The measured wind speed in the area to be tested is expressed in m / s.

[0044] Step S620: The control host corrects the first gas concentration value and the second gas concentration value based on the effective parameter correction model.

[0045] In the seventh embodiment of the pipeline leak detection method based on gas tracing proposed in this invention, based on the fifth embodiment, step S170 includes the following steps: Step S710: The control host constructs multiple sets of axial gas concentration gradient curves of the pipeline based on the corrected effective parameters, and uses a Gaussian fitting algorithm to fit the gas concentration gradient curves. The gas concentration in the gas concentration gradient curve is the first gas concentration. Each row of sensor modules corresponds to one gas concentration gradient curve. The total number of gas concentration gradient curves is consistent with the total number of columns of sensor modules.

[0046] Step S720: The control host determines the position of the sensing unit corresponding to the peak value in the gas concentration gradient curve, and then, in combination with the data parameters of multiple adjacent sensor modules, establishes a leak point diffusion model. By solving the zero point of the second derivative of the leak point diffusion model, the coordinates of the leak point in the pipeline under test are located.

[0047] Specifically, based on the corrected effective parameters, the leak point of the pipeline under test is accurately located through "gradient fitting + diffusion modeling".

[0048] In the eighth embodiment of the pipeline leak detection method based on gas tracing proposed in this invention, based on the seventh embodiment, step S720 includes the following steps: Step S810: The control host uses the row of sensor modules corresponding to the gas concentration gradient curve with the largest peak point among multiple gas concentration gradient curves as a reference line, and sets the position of the sensor module corresponding to the largest peak point on the reference line as... .

[0049] Step S820: The control host establishes a leak propagation model: (2), In the formula, The calibration gas concentration at point x on the reference line in the area to be measured; The first gas concentration collected by the sensor module corresponding to the maximum peak point; The diffusion coefficient is calculated using the following formula: (3), Step S830: The control host will The x-position point corresponding to the maximum value is taken as the coordinate of the leak point in the pipe under test.

[0050] Specifically, the results calculated using the diffusion model The x-position point corresponding to the maximum value is the closest point to the leak point in the pipe being tested. Therefore, The x-position point (on the reference line) corresponding to the maximum value is used as the coordinate of the leak point in the pipe to be tested.

[0051] Compared with existing technologies, this solution has the following advantages: 1. Significantly improved anti-interference capability: Through "dual tracer gas ratio verification + environmental correction", the false detection rate is reduced to below 0.5%, which is more than 30 times lower than the traditional single tracer method.

[0052] 2. Breakthrough in positioning accuracy: 2-meter spacing sensor array + Gaussian fitting + diffusion modeling, leak point positioning error ≤ ±0.5 meters, which is 20 times more accurate than traditional methods. It can directly guide precise excavation and maintenance and reduce ineffective construction.

[0053] This invention also proposes a pipeline leak detection system based on gas tracing, which applies a pipeline leak detection method based on gas tracing; the system includes a gas injection device, a sensor module, and a control host; the sensor module and the control host are communicatively connected.

[0054] The sequence numbers of the above embodiments of the present invention are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0055] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention without departing from the spirit and scope of the claims. All of these forms are within the protection scope of the present invention.

Claims

1. A pipeline leak detection method based on gas tracing, characterized in that, An application to a gas-tracing-based pipeline leak detection system; the system includes a gas injection device, a sensor module, and a control host; the sensor module and the control host are communicatively connected; the method includes: The gas injection device injects composite tracer gas into the inlet end of the pipeline to be tested; Multiple sensor modules are manually deployed on the ground in the area to be tested. The pipeline to be tested is located underground in the rectangular area. The multiple sensor modules are distributed in a matrix within the area to be tested. Each sensor module includes a gas sensor, a wind speed sensor, and a temperature sensor. The sensor module collects data parameters in real time and sends them to the control host. The data parameters include gas concentration value, real-time wind speed value, and real-time temperature value. The control host determines whether the data parameters collected by the current sensor module at its current location are interference data based on the gas concentration value; If the data parameter is interference data, the control host will mark the data parameter as invalid and discard it; If the data parameter is not interfering data, the control host will mark the data parameter as a valid parameter, and integrate the real-time wind speed value and real-time temperature value in the valid parameter to correct the valid parameter; The control host determines the location of the leak in the pipeline under test based on the corrected effective parameters.

2. The pipeline leak detection method based on gas tracing according to claim 1, characterized in that, The gas injection device includes a gas storage tank, a pressure sensor, a flow sensor, and a control valve; the gas injection device injects composite tracer gas into the inlet end of the pipeline under test, including: The first tracer gas and the second tracer gas are mixed in a preset ratio to form a composite tracer gas, and the composite tracer gas is filled into a gas storage tank. Connect the outlet of the gas storage tank to the inlet of the pipeline under test, close the outlet of the pipeline under test, and start the control valve to fill the pipeline under test with composite tracer gas.

3. The pipeline leak detection method based on gas tracing according to claim 2, characterized in that, The first tracer gas is SF6; the second tracer gas is C7H5F3.

4. The pipeline leak detection method based on gas tracing according to claim 2, characterized in that, The gas injection device injects the composite tracer gas into the inlet end of the pipeline to be tested, and then includes: The pressure sensor acquires the real-time pressure value of the pipeline under test and sends it to the control host. The flow sensor acquires the real-time flow value of the pipe under test and sends it to the control host; The control host calculates the injection flow rate of the composite tracer gas based on real-time pressure and flow rates, and adjusts the injection flow rate through a control valve to keep the concentration of the composite tracer gas in the pipeline under test within a preset range.

5. The pipeline leak detection method based on gas tracing according to claim 2, characterized in that, The gas sensor includes a first gas sensor and a second gas sensor; the sensor module collects data parameters in real time and sends them to the control host, including: The first gas sensor detects the concentration value of the first tracer gas in real time and marks it as the first gas concentration value, which is then sent to the control host. The second gas sensor detects the concentration value of the second tracer gas in real time and marks it as the second gas concentration value, which is then sent to the control host. The control host marks the first gas concentration value and the second gas concentration value as gas concentration values; The control host determines whether the data parameters collected by the current sensor module at its location are interference data based on the gas concentration value, including: The control host determines whether the ratio of the first gas concentration value and the second gas concentration value is greater than a first preset value or less than a second preset value, wherein the second preset value is less than the first preset value; If so, the control host determines that the data parameters collected by the current sensor module at its location are interference data; If not, the control host determines that the data parameters collected by the current sensor module are not interference data.

6. The pipeline leak detection method based on gas tracing according to claim 5, characterized in that, If the data parameter is not interfering data, the control host marks the data parameter as a valid parameter, and integrates the real-time wind speed value and real-time temperature value from the valid parameter to correct the valid parameter, including: The control host establishes an effective parameter correction model: （1）， In the formula, This is the corrected gas concentration value. These are the measured gas concentration values; The standard temperature is 293.15 K; T is the measured temperature of the area to be measured, in K. Standard wind speed, in m / s; The measured wind speed in the area to be measured is expressed in m / s. The control host corrects the first gas concentration value and the second gas concentration value based on the effective parameter correction model.

7. The pipeline leak detection method based on gas tracing according to claim 5, characterized in that, The control host determines the leak location of the pipeline under test based on the corrected effective parameters, including: The control host constructs multiple sets of axial gas concentration gradient curves of the pipeline based on the corrected effective parameters, and uses a Gaussian fitting algorithm to fit the gas concentration gradient curves. The gas concentration in the gas concentration gradient curve is the first gas concentration. Each row of sensor modules corresponds to one gas concentration gradient curve, and the total number of gas concentration gradient curves is consistent with the total number of columns of sensor modules. The control host determines the position of the sensing unit corresponding to the peak value in the gas concentration gradient curve, and then establishes a leak point diffusion model by combining the data parameters of multiple adjacent sensor modules. By solving the zero point of the second derivative of the leak point diffusion model, the coordinates of the leak point in the pipeline under test can be located.

8. The pipeline leak detection method based on gas tracing according to claim 7, characterized in that, The control host determines the position of the sensing unit corresponding to the peak value in the gas concentration gradient curve, and then, by combining the data parameters of multiple adjacent sensor modules, establishes a leak point diffusion model. By solving for the zero point of the second derivative of the leak point diffusion model, the coordinates of the leak point in the pipeline under test are located, including: The control host uses the row of sensor modules corresponding to the gas concentration gradient curve with the largest peak among multiple gas concentration gradient curves as a reference line, and the position of the sensor module corresponding to the largest peak point on the reference line is set as follows: ; The control host establishes a leak propagation model: （2）， In the formula, The calibration gas concentration at point x on the reference line in the area to be measured; The first gas concentration collected by the sensor module corresponding to the maximum peak point; The diffusion coefficient is calculated using the following formula: （3）， The control host will The x-position point corresponding to the maximum value is taken as the coordinate of the leak point in the pipe under test.

9. A pipeline leak detection system based on gas tracing, characterized in that, The method for detecting pipeline leaks based on gas tracing, as described in any one of claims 1-8, comprises a gas injection device, a sensor module, and a control host; the sensor module and the control host are communicatively connected.

Images