A method for multi-parameter intelligent leakage monitoring and positioning of a long brine pipeline

Abstract

This invention discloses a multi-parameter intelligent leak monitoring and location method for long-distance brine pipelines, relating to the field of pipeline safety monitoring technology. The method includes the following steps: Step S1: Deployment of multi-parameter acquisition nodes; Step S2: Real-time acquisition of multi-parameters; Step S3: Dual-parameter fusion leak judgment; Step S4: Leak point location calculation. This method solves the problem in existing technologies where long-distance brine / saltwater pipelines, complex terrain, non-full-pipe operation, and field deployment make it difficult to achieve low false alarms, high accuracy, pipe-break-free operation, and easy maintenance for leak monitoring and location under special working conditions.

Description

Technical Field

[0001] This invention relates to the field of pipeline safety monitoring technology, specifically to a multi-parameter intelligent leak monitoring and location method for long-distance brine pipelines. Background Technology

[0002] Long-distance pipelines are the core carriers for transporting fluid materials such as brine and saline solution in the salt industry and chemical industry. With advantages such as continuous closed-loop transportation, low loss, and low operating costs, they are widely used in scenarios such as well salt mining and the export of chemical raw materials. Long-distance brine pipelines are typically characterized by long transportation distances, significant terrain undulations along the route, numerous elevation points, and complex laying environments. Some pipelines traverse remote areas, facing long-term risks such as geological disasters, human-caused damage, pipe corrosion and aging, and fluctuations in valve chamber operating conditions. Once a leak occurs, it will not only cause the loss of brine raw materials and significantly increase the production costs of enterprises, but also pollute the soil and surface water, damage the surrounding ecological environment, and even cause production safety accidents, posing a serious threat to the safe operation of the pipeline and environmental protection. Therefore, achieving real-time monitoring, accurate judgment, and rapid location of leaks in long-distance brine pipelines is a core technical requirement for ensuring the continuous and stable operation of the pipeline.

[0003] Currently, traditional pipeline leak detection technologies are mostly used in conventional fluid pipelines such as oil and tap water, and there are many technical shortcomings when directly applied to long-distance brine pipelines: 1. Single monitoring method and high false alarm rate: Mainstream technologies only use single parameter monitoring such as pressure negative pressure wave or flow rate, which are easily affected by normal operating conditions such as pump stoppage, pressure buildup, pipeline venting, and valve adjustment. They cannot effectively distinguish between leakage signals and operating condition fluctuations, resulting in frequent false alarms and high risk of missed alarms, making it difficult to meet the high reliability monitoring requirements of industrial sites.

[0004] 2. Poor adaptability to non-full pipe / negative pressure areas: There are multiple elevation points along the brine long-distance pipeline. After low-flow transportation or shutdown, non-full pipe flow and negative pressure areas are easily formed. Traditional pressure wave monitoring technology suffers from signal interruption and severe attenuation in these areas, making it impossible to properly capture leakage characteristics, and even creating monitoring blind spots.

[0005] 3. High difficulty in on-site deployment and operation and maintenance: Traditional monitoring equipment often requires pipe breaking for installation, which is complex and damages the original pipeline structure. At the same time, valve chambers along the pipeline are mostly located in the field environment without mains power and with weak communication signals, making it difficult to guarantee power supply and data transmission for the equipment, and thus impossible to achieve stable operation around the clock.

[0006] 4. Insufficient positioning accuracy: Existing leak location methods do not combine actual pipeline elevation data and the distribution of non-full pipe sections to correct for pressure wave propagation speed and delay, resulting in large positioning errors and making it difficult to provide accurate location support for on-site emergency repairs.

[0007] In summary, existing leak detection technologies are ill-suited to the special operating conditions of long-distance brine pipelines, such as long distances, complex terrain, non-full-pipe operation, and field deployment. They struggle to achieve leak detection and location with low false alarms, high accuracy, no pipe breakage required, and easy maintenance. Therefore, there is an urgent need to develop an intelligent leak detection and location technology that is adaptable to complex operating conditions and suitable for field deployment. Summary of the Invention

[0008] The purpose of this invention is to solve the problem that existing technologies for long-distance brine / salt water pipelines, which are subject to special conditions such as long distances, complex terrain, non-full-pipe operation, and field deployment, make it difficult to achieve leak monitoring and location with low false alarms, high accuracy, no pipe breakage, and easy maintenance. The invention proposes a multi-parameter intelligent leak monitoring and location method for long-distance brine pipelines.

[0009] This invention is achieved through the following technical solution: A multi-parameter intelligent leak monitoring and location method for long-distance brine pipelines includes the following steps: Step S1: Deployment of multi-parameter acquisition nodes The brine / salt water export pipeline is divided into multiple monitoring zones, and pressure monitoring nodes and flow monitoring nodes are set up at the beginning and end of the pipeline and at key valve chambers or vent valves along the pipeline. Step S2: Real-time acquisition of multiple parameters Real-time collection of pressure data from each pressure monitoring node and flow data from each flow monitoring node; Step S3: Two-parameter fusion leakage judgment Using the characteristics of pressure transient negative pressure wave and the characteristics of interval flow difference as the joint judgment criteria, when the pressure wave characteristics are detected at the same time and the interval flow imbalance value between adjacent monitoring points exceeds the preset threshold, a leak is determined and an alarm is triggered; if only a single parameter meets the leak characteristics, it is judged as a normal operating condition disturbance and no leak alarm is triggered. Step S4: Leakage point location calculation After a leak alarm is triggered, the location of the leak point is calculated using the negative pressure wave positioning formula. Based on pipeline elevation data and non-full pipe section data, the wave velocity and propagation delay are corrected, and the distance from the leak point to the beginning of the pipeline is output.

[0010] Furthermore, in step S1, pressure monitoring nodes are installed at the beginning and end of the pipeline and at the exhaust valves along the pipeline. The pressure monitoring nodes achieve pressure acquisition without breaking the pipe by adding a short circuit and pressure tapping pipe at the ball valve of the exhaust valve. Flow monitoring nodes are installed at the beginning and end of the pipeline and at the shut-off valves along the pipeline. The flow monitoring nodes use suspended ultrasonic flow meters to collect flow without breaking the pipe.

[0011] Furthermore, at least four key venting valve chambers are set up along the brine / salt water export pipeline, and pressure monitoring nodes are installed in the venting valve chambers; the pressure transmitters configured in the pressure monitoring nodes are explosion-proof, with an accuracy of not less than 0.075% FS and a pressure resistance of not less than 1.5MPa; At least three shut-off valve chambers are set up along the brine / salt water export pipeline. Flow monitoring nodes are arranged in the shut-off valve chambers. The ultrasonic flow meter meets the installation requirements of a straight pipe section of 5D before and 2.5D after the pipe section, and the measurement accuracy is not less than ±1%.

[0012] Furthermore, in step S1, the long-distance pipeline is divided into several monitoring intervals according to the valve chamber location, and each interval is independently judged for flow imbalance.

[0013] Furthermore, in step S3, the interval flow imbalance value is the ratio of the flow difference between two adjacent flow monitoring nodes to the theoretical transport flow; the preset threshold is 5%~10%.

[0014] Furthermore, in step S4, the negative pressure wave positioning formula is: X = L - a × Δt Where X is the distance from the leak point to the beginning, L is the total length of the pipeline, a is the measured sound velocity of the brine medium, and Δt is the time difference between upstream and downstream pressure wave reception. The corrections include: correcting the pressure wave propagation speed based on pipeline elevation data, and correcting the pressure wave propagation delay based on the length and distribution of non-full pipe sections.

[0015] Furthermore, it also includes a false alarm intelligent elimination step: establishing a normal operating condition pressure / flow waveform feature library including pump stop, pressure buildup, and venting, comparing the real-time collected waveforms with the feature library, filtering out disturbance signals without leakage characteristics, and marking the operating condition that triggered the alarm in the alarm information.

[0016] Furthermore, it also includes adaptation and optimization steps for non-full pipe / negative pressure areas: install intelligent exhaust valves that only exhaust air and do not suck air at the high-point exhaust valve to prevent air from entering the pipe; A regulating valve is installed at the end of the pipeline to automatically adjust the opening based on the high-point pressure data, eliminate negative pressure zones, and ensure full-pipe operation and normal propagation of pressure waves.

[0017] Furthermore, it also includes field operation and maintenance support steps: deploying a solar power supply system at the valve chamber to provide power to the pressure monitoring nodes and flow monitoring nodes, meeting the power supply requirements for 10 consecutive cloudy and rainy days, with equipment power consumption ≤15W; using 4G / GPRS wireless communication to upload the collected data to the monitoring server, and relaying the data through short-range data transmission modules in weak signal sections.

[0018] Furthermore, the brine long-distance pipeline is a single pipeline or two pipelines arranged in parallel, with pressure monitoring nodes and flow monitoring nodes deployed independently on the two pipelines respectively.

[0019] Furthermore, the response time of the leakage alarm is ≤180s, and the leakage point location radius error is ≤±150m.

[0020] Compared with the prior art, the present invention has the following advantages and beneficial effects: I. This invention proposes a multi-parameter intelligent leak monitoring and location method for long-distance brine pipelines. Through core steps such as multi-parameter acquisition node deployment, real-time multi-parameter acquisition, dual-parameter fusion leak judgment, and leak point location calculation, and with supporting optimization measures such as false alarm elimination, non-full pipe adaptation, and field operation and maintenance support, this method achieves leak monitoring and location with low false alarms, high accuracy, no pipe breakage required, and easy operation and maintenance in special working conditions such as long distances, complex terrain, non-full pipe operation, and field deployment of brine / salt water pipelines.

[0021] II. This invention proposes a multi-parameter intelligent leak monitoring and location method for long-distance brine pipelines. It employs a dual-parameter joint judgment logic based on pressure transient negative pressure waves and interval flow differences, effectively distinguishing between normal operating disturbances such as pump shutdown, pressure buildup, and venting, and genuine leak signals, thus reducing false alarms at the source. Combined with intelligent filtering using a normal operating condition waveform feature library, the number of false alarms under steady-state conditions is controlled to ≤10 times / year, with no missed alarms when there are no equipment or communication failures, significantly improving monitoring reliability.

[0022] Thirdly, this invention proposes a multi-parameter intelligent leak monitoring and location method for long-distance brine pipelines. Pressure monitoring is achieved through a short-circuit connection of an exhaust valve and a pressure tapping pipe, while flow monitoring utilizes a suspended ultrasonic flow meter. The entire process requires no pipe breaking or modification of the existing pipeline. It is simple to construct, has a short construction period, and eliminates the risk of media leakage, making it suitable for the rapid deployment needs of both existing and newly constructed pipelines.

[0023] Fourth, this invention utilizes an intelligent exhaust valve that "only exhausts, does not inhale," installed at high points, in conjunction with an automatic regulating valve at the end, to eliminate air intake and negative pressure zones within the pipe, ensuring stable propagation of pressure waves. Simultaneously, a positioning algorithm, combined with data from non-full pipe sections, corrects propagation delays, completely resolving the monitoring failure issues of traditional technologies at high points and downhill sections of pipelines. This design is adaptable to non-full / negative pressure zones, eliminating monitoring blind spots.

[0024] V. In this invention, a negative pressure wave positioning formula is adopted, and pipeline elevation data is used to correct the wave velocity, and non-full pipe data is used to correct the delay. The leak alarm response time is ≤180s, and the positioning radius error is ≤±150m. It can quickly locate the leak, significantly shorten the repair time, and reduce resource loss and environmental risks. This design provides fast and accurate leak positioning, supporting efficient emergency repairs.

[0025] VI. In this invention, the valve chamber is powered by solar energy, ensuring stable operation for 10 consecutive cloudy or rainy days, with a single device power consumption of ≤15W. Data transmission utilizes a combination of 4G / GPRS and short-range data transmission module relays, adapting to scenarios where remote valve chambers lack mains power or have weak signals, achieving stable 24 / 7 unattended operation. This design exhibits strong adaptability to outdoor environments and low maintenance costs.

[0026] VII. This invention supports independent monitoring of single and dual pipelines arranged in parallel, and is compatible with various salt industry chemical media such as brine and saline. Monitoring zones can be flexibly divided according to valve chambers, making it suitable for leak monitoring of long-distance brine pipelines in complex terrains. Attached Figure Description

[0027] Figure 1 This is a flowchart of the present invention.

[0028] Figure 2 This is a deployment diagram of pressure monitoring nodes and flow monitoring nodes.

[0029] Figure 3 This is a schematic diagram of the negative pressure wave / sound wave method for positioning.

[0030] Figure 4 This is a schematic diagram of the pressure transmitter installation.

[0031] Figure 5 This is an installation diagram of an ultrasonic flow meter for shut-off valve chambers. Detailed Implementation

[0032] The present invention will be further described in detail below with reference to embodiments, but the implementation of the present invention is not limited thereto.

[0033] Example 1 This embodiment takes the newly built brine / salt water long-distance transmission pipeline of Leshan Fuchuan Company as an example to implement the multi-parameter intelligent leakage monitoring and location method for brine long-distance transmission pipelines described in this invention. Those skilled in the art can refer to this embodiment to realize leakage monitoring and location of similar pipelines. Unless otherwise specified, all technical means are conventional techniques in the field.

[0034] In this embodiment, the target pipeline is approximately 30km long and is arranged in parallel with two pipelines: a DN500 brine pipeline and a DN450 saline pipeline. The pipeline starts at a brine transfer station in a town in Jingyan County and ends at Fuhua Tongda Chemical Plant in Wutongqiao District. The terrain along the route is highly undulating, and five shut-off valve chambers and 18 high-point exhaust valve chambers are pre-set. High-risk leakage sections are concentrated in the latter half of the pipeline.

[0035] refer to Figure 1 This embodiment adopts a three-tier architecture design consisting of a control center layer, a data transmission layer, and a field monitoring layer. The composition and functions of each layer are as follows: Control Center Layer: This mainly includes monitoring servers and host computer data processing software. The core of the host computer software is used to perform leak detection, leak location calculation, false alarm elimination, and to visualize the relevant data.

[0036] Data transmission layer: Composed of field data acquisition terminals, data relay modules and 4G / GPRS sub-modules, responsible for data transmission and relay forwarding.

[0037] On-site monitoring layer: Equipped with pressure monitoring points, flow monitoring points and intelligent control equipment for real-time monitoring and intelligent control of on-site working conditions.

[0038] This embodiment is implemented according to the following steps: Step 1: Deployment of multi-parameter acquisition nodes.

[0039] The pipeline is divided into 6 independent monitoring sections based on the valve chamber location. Each section independently performs flow imbalance judgment. Pressure and flow monitoring nodes are independently deployed on both pipelines, as follows: Deployment of pressure monitoring nodes: Because the shut-off valve chamber does not meet the requirements for adding a tee, the pressure signal acquisition points need to be selected from the 18 pre-designed exhaust valves. Based on GPS elevation parameters, 5 locations were selected from the 18 existing exhaust valve chambers as pressure monitoring points. That is, pressure monitoring nodes will be deployed at the beginning of the pipeline (brine transfer station), the end of the pipeline (Wutong plant area), and 5 key exhaust valve chambers along the pipeline, for a total of 7 points / single pipeline and 14 points / dual pipeline.

[0040] The pressure transmitter adopts the following pipe-break-free installation method: (Reference) Figure 4 A short pipe fitting is added between the DN100 ball valve and the automatic air release valve, and a DN15 pressure tap is led out from the short pipe and a DN15 stainless steel ball valve is installed; the pressure transmitter and the ball valve are connected by a stainless steel joint through a threaded connection.

[0041] The pressure transmitter selected is the explosion-proof Rosemount 3051TG series, with an accuracy of 0.075%FS and a pressure resistance of 1.5MPa, meeting the requirements for explosion-proof and measurement accuracy in the field.

[0042] Deployment of traffic monitoring nodes: Flow monitoring nodes are installed at the beginning and end of the pipeline and at three shut-off valve chambers (161#, 272#, WT39#) along the pipeline, for a total of 5 nodes per single pipeline and 10 nodes per dual pipeline.

[0043] Flow rate is detected using a suspended ultrasonic flow meter, reference Figure 5The valve chamber for this flow meter should be located at the lowest point of the pipeline, ensuring that the medium in the measuring pipe section is in a full-pipe flow state. During installation, the straight pipe section layout requirements must be met: the length of the straight pipe section before the flow meter should be no less than 5D, and the length of the straight pipe section after the flow meter should be no less than 2.5D (taking a DN500 pipeline as an example, the length of the straight pipe section before the ultrasonic external sensor is 5 meters, and the length of the straight pipe section after the sensor is 2.5 meters). This flow meter requires no pipe-breaking modifications for installation, and its measurement accuracy can reach ±1%, making it suitable for brine medium measurement and field installation conditions. This design facilitates accurate measurement of the flow signal at the observation point; with the flow signal, the direction of the leak signal can be correctly determined, thereby improving the reliability of the alarm.

[0044] Additionally, if space permits, the sensor should be installed as far away from the shut-off valve as possible.

[0045] The pressure and flow signals at the beginning and end of the system reuse data from the original automatic control system and are connected to the monitoring system through physical signal isolation, without adding instruments.

[0046] Deployment reference for pressure monitoring nodes and flow monitoring nodes Figure 2 .

[0047] Step 2: Real-time acquisition of multiple parameters.

[0048] Each monitoring node collects data in real time using a high-frequency sampling mode: the pressure monitoring node continuously collects pipeline pressure transient data, and the flow monitoring node collects interval flow data in real time; after the collected data is preprocessed by the on-site acquisition terminal, it is uploaded to the monitoring server via wireless communication to achieve 24 / 7 uninterrupted acquisition and provide real-time data support for leak detection.

[0049] Step 3: Two-parameter fusion leakage judgment.

[0050] The system uses the characteristics of transient negative pressure waves and the characteristics of flow difference between regions as the joint judgment criteria, and executes the following logic: Real-time analysis of pressure data to identify typical negative pressure waveforms indicating leakage; Calculate the flow imbalance value (flow difference / theoretical transport flow) between adjacent flow monitoring nodes. In this embodiment, the preset threshold is 8%. Judgment rules: Simultaneously, if the pressure wave matches the leakage waveform and the flow imbalance value is >8%, it is immediately determined that a pipeline leak has occurred and an alarm is triggered. If only a single parameter meets the leakage characteristics, it is judged as a normal operating condition disturbance such as pump stoppage, pressure buildup, or venting, and no alarm is triggered.

[0051] Step 4: Leakage point location calculation.

[0052] Upon triggering a leak alarm, the system immediately initiates location calculations. This means the system analyzes and locates leaks by real-time monitoring of pressure waves and flow rates at various points along the pipeline. When a leak occurs, the pipeline leak monitoring system detects a sudden pressure drop at the leak point. This negative pressure fluctuation propagates at a certain speed from the leak point towards both ends of the pipeline. Pressure sensors installed at both ends of the pipeline capture the waveform of this specific transient pressure wave, which is then used by the software to determine the leak. To achieve accurate location, the leak detection software calculates the location using the pipeline length, precisely measured pressure wave propagation speed in the pipeline medium, and the time difference between the upstream and downstream pressure sensors receiving the pressure wave.

[0053] refer to Figure 3 The negative pressure wave positioning formula is used: X = L - a × Δt. In the formula: X is the distance from the leak point to the beginning end, m; L is the total length of the pipeline, m; a is the measured sound velocity of the brine medium; Δt is the time difference between upstream and downstream pressure wave reception, s.

[0054] Positioning Correction: The pressure wave propagation speed is corrected by combining the elevation data of this pipeline, and the pressure wave propagation delay is corrected by combining the distribution of the non-full pipe section in the second half of the pipeline. The influence of terrain and flow pattern on positioning accuracy is eliminated, and the precise distance from the leak point to the beginning of the pipeline is finally output.

[0055] Supporting optimization measures were implemented.

[0056] False alarms can be intelligently eliminated.

[0057] The system has a built-in normal operating condition waveform feature library, which includes disturbance waveforms such as pump stoppage, pressure buildup, valve regulation, and pipeline venting. The waveforms collected in real time are automatically compared with the feature library to filter out disturbance signals without leakage characteristics. At the same time, the cause of the operating condition is marked in the alarm information, and the number of false alarms under steady-state conditions is controlled to ≤10 times / year.

[0058] Optimization for non-full pipe / negative pressure zones.

[0059] Intelligent exhaust valves that only exhaust air and do not draw air are installed at the high points along the entire pipeline to prevent air from entering the pipeline; regulating valves are installed at the end of the pipeline to automatically adjust the opening based on the high-point pressure data, eliminate negative pressure zones, and ensure full pipeline operation and normal propagation of pressure waves.

[0060] Field operation and maintenance support.

[0061] In this embodiment, for locations with inconvenient power supply, a solar power system can be deployed in each valve chamber. Solar power supply must meet the power requirements for 10 consecutive cloudy / rainy days, with a single device power consumption ≤15W. Data transmission uses 4G / GPRS wireless communication. In areas with weak signals, data is relayed via short-range data transmission modules (i.e., data is first sent to adjacent points using short-range data transmission modules, and then transmitted outwards by devices at those adjacent points), ensuring stable data upload from field nodes.

[0062] Technical specifications of this embodiment.

[0063] Leakage alarm response time: ≤180s; Leakage point location radius error: ≤ ±150m; Number of false alarms under steady-state conditions: ≤10 times / year; The system operates stably 24 / 7 with no missed alarms (except for equipment and communication failures).

[0064] This embodiment, through technologies such as dual-parameter fusion judgment, pipe-break-free deployment, non-full pipe adaptation, and field operation and maintenance support, perfectly adapts to the complex working conditions of long-distance brine pipelines, achieving rapid identification, accurate location, and low false alarm operation of leaks. It can be directly promoted and applied to the safety monitoring of similar long-distance salt and chemical pipelines.

[0065] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Any simple modifications or equivalent changes made to the above embodiments based on the technical essence of the present invention shall fall within the protection scope of the present invention.

Claims

1. A multi-parameter intelligent leak monitoring and location method for long-distance brine pipelines, characterized in that, Includes the following steps: Step S1: Deployment of multi-parameter acquisition nodes The brine / salt water export pipeline is divided into multiple monitoring zones, and pressure monitoring nodes and flow monitoring nodes are set up at the beginning and end of the pipeline and at key valve chambers or vent valves along the pipeline. Step S2: Real-time acquisition of multiple parameters Real-time collection of pressure data from each pressure monitoring node and flow data from each flow monitoring node; Step S3: Two-parameter fusion leakage judgment Using the characteristics of pressure transient negative pressure wave and the characteristics of interval flow difference as the joint judgment criteria, when the pressure wave characteristics are detected at the same time and the interval flow imbalance value between adjacent monitoring points exceeds the preset threshold, a leak is determined and an alarm is triggered; if only a single parameter meets the leak characteristics, it is judged as a normal operating condition disturbance and no leak alarm is triggered. Step S4: Leakage point location calculation After a leak alarm is triggered, the location of the leak point is calculated using the negative pressure wave positioning formula. Based on pipeline elevation data and non-full pipe section data, the wave velocity and propagation delay are corrected, and the distance from the leak point to the beginning of the pipeline is output.

2. The method according to claim 1, characterized in that: In step S1, pressure monitoring nodes are set up at the beginning and end of the pipeline and at the exhaust valves along the pipeline. The pressure monitoring nodes achieve pressure acquisition without breaking the pipe by adding a short circuit and pressure tapping pipe to the ball valve of the exhaust valve. Flow monitoring nodes are installed at the beginning and end of the pipeline and at the shut-off valves along the pipeline. The flow monitoring nodes use suspended ultrasonic flow meters to collect flow without breaking the pipe.

3. The method according to claim 2, characterized in that: At least four key venting valve chambers are set up along the brine / salt water export pipeline, and pressure monitoring nodes are installed in the venting valve chambers; the pressure transmitters configured in the pressure monitoring nodes are explosion-proof, with an accuracy of not less than 0.075% FS and a pressure resistance of not less than 1.5MPa; At least three shut-off valve chambers are set up along the brine / salt water export pipeline. Flow monitoring nodes are arranged in the shut-off valve chambers. The ultrasonic flow meter meets the installation requirements of a straight pipe section of 5D before and 2.5D after the pipe section, and the measurement accuracy is not less than ±1%.

4. The method according to claim 1, characterized in that: In step S1, the long-distance pipeline is divided into several monitoring intervals according to the valve chamber location, and each interval is independently judged for flow imbalance.

5. The method according to claim 1, characterized in that: In step S3, the interval flow imbalance value is the ratio of the flow difference between two adjacent flow monitoring nodes to the theoretical transport flow; the preset threshold is 5%~10%.

6. The method according to claim 1, characterized in that, In step S4, the negative pressure wave positioning formula is: X = L - a × Δt Where X is the distance from the leak point to the beginning, L is the total length of the pipeline, a is the measured sound velocity of the brine medium, and Δt is the time difference between upstream and downstream pressure wave reception. The corrections include: correcting the pressure wave propagation speed based on pipeline elevation data, and correcting the pressure wave propagation delay based on the length and distribution of non-full pipe sections.

7. The method according to claim 1, characterized in that, It also includes a false alarm intelligent elimination step: establishing a normal operating condition pressure / flow waveform feature library including pump stop, pressure buildup, and venting, comparing the real-time collected waveforms with the feature library, filtering out disturbance signals without leakage characteristics, and marking the operating condition that triggered the alarm in the alarm information.

8. The method according to claim 1, characterized in that, It also includes adaptation and optimization steps for non-full pipe / negative pressure areas: install an intelligent exhaust valve that only exhausts air and does not suck in air at the high-point exhaust valve to prevent air from entering the pipe; A regulating valve is installed at the end of the pipeline to automatically adjust the opening based on the high-point pressure data, eliminate negative pressure zones, and ensure full-pipe operation and normal propagation of pressure waves.

9. The method according to claim 1, characterized in that, It also includes field operation and maintenance support steps: deploying a solar power system at the valve chamber to provide power to the pressure monitoring node and flow monitoring node, which can meet the power supply requirements for 10 consecutive cloudy and rainy days, with equipment power consumption ≤15W; using 4G / GPRS wireless communication to upload the collected data to the monitoring server, and relaying the data through short-range data transmission modules in weak signal sections.

10. The method according to claim 1, characterized in that, The brine long-distance pipeline is arranged as a single pipeline or two pipelines in parallel, with pressure monitoring nodes and flow monitoring nodes deployed independently on the two pipelines respectively.

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