Ship seawater pipeline leakage diagnosis system

Abstract

The invention belongs to the technical field of pipeline leakage diagnosis, and particularly relates to a ship seawater pipeline leakage diagnosis system. Comprising an equipment layer and a control layer. The equipment layer is provided with a pipeline, a flow meter, a pressure meter, a water tank, a centrifugal pump and a leakage switch valve; the control layer is provided with a PLC (Programmable Logic Controller) and a touch screen; wherein the flowmeter is installed at the head end of a to-be-detected pipeline and used for monitoring the seawater flow change condition in real time, and the pressure gauges are installed at the head end and the tail end of the to-be-detected pipeline and used for monitoring the fine change of seawater pressure in real time. The ship seawater pipeline leakage diagnosis system is simple in implementation scheme, easy to implement and rapid in leakage diagnosis and positioning process, can meet the requirements of leakage analysis and positioning in various ship pipeline systems, does not need too complex equipment, can be used as a leakage diagnosis means of various base pipelines, and has a wide application prospect. The system can also be used as a redundant system of an existing leakage analysis and diagnosis system or structure, and the effectiveness of leakage diagnosis is further improved.

Description

Technical Field

[0001] The invention belongs to the technical field of pipeline leakage diagnosis, and in particular relates to a ship seawater pipeline leakage diagnosis system. Background Art

[0002] With the continuous development of the shipping industry, the safety and operational efficiency of ships have become the focus of the industry. As an important part of the ship, the operating status of the seawater pipeline is directly related to the overall performance of the ship. However, the traditional means of managing the seawater pipeline of ships mainly rely on manual inspections and simple sensor monitoring. These methods have problems such as low efficiency, slow response speed, and high false alarm rate, and cannot meet the high requirements of the modern shipping industry for safety and operational efficiency. During the operation of the ship, the seawater pipeline may leak due to material aging, improper installation, corrosion, etc., which will not only lead to waste of resources, but also pose a threat to the safety of the ship. Traditional leakage detection methods, such as observation, listening, and test paper detection, often have shortcomings such as long detection cycle and low accuracy, making it difficult to detect and deal with leakage problems in time. In order to solve these problems, a variety of seawater pipeline leakage diagnosis and control systems based on sensors and automation technology have emerged in recent years. These systems achieve accurate diagnosis and efficient control of leaks by real-time monitoring of the operating status of the seawater pipeline and using advanced algorithms and data analysis technologies. However, there are still some shortcomings in the existing systems, such as the need to improve the accuracy of diagnosis, the inflexible control strategy, and the unfriendly user experience. Summary of the invention

[0003] In order to solve the above problems, the present invention proposes a ship seawater pipeline leakage diagnosis system, which aims to analyze and locate pipeline leakage faults in a simpler and more efficient manner.

[0004] To achieve the above purpose, the present invention adopts the following technical solution.

[0005] A ship seawater pipeline leakage diagnosis system includes an equipment layer and a control layer; the equipment layer is equipped with a pipeline 1, a flow meter 2, a pressure gauge, a water tank 3, a centrifugal pump 4 and a leakage switch valve 5; the control layer is equipped with a PLC controller 6 and a touch screen 7;

[0006] The flow meter 2 is installed at the head end of the pipeline to be tested to monitor the change of seawater flow in real time, and the pressure gauge is installed at the head and tail ends of the pipeline to be tested to monitor the subtle changes of seawater pressure in real time.

[0007] In a further improvement or preferred embodiment of the above-mentioned ship seawater pipeline leakage diagnosis system, the PLC controller determines the leakage and locates the leakage position based on the following method:

[0008] Step a1, leakage judgment: Continuously detect the flow change at the head end of the pipeline to detect whether there is a sudden increase in flow. If so, compare the average flow Q after the sudden increase. t The difference between the average flow rate Q0 before the mutation ΔQ = Q t -Whether Q0 exceeds the empirical threshold Q￠. If it exceeds, it means leakage occurs. If it does not exceed, no treatment will be given. If a sudden decrease in flow occurs at the head end of the pipeline, it is necessary to conduct a leakage analysis on the previous section of the pipeline. The empirical threshold Q￠ is obtained by analyzing the historical leakage data of the current pipeline, and is generally not lower than the average flow Q after a sudden increase in the historical leakage data. t Compared with the minimum value of the average flow Q0 before the mutation, due to the hysteresis of pipeline flow, when necessary, it can also be assisted by judging whether the duration of the sudden increase in flow is within a reasonable time period. If the mutation period is very short, it indicates that it may be caused by the movement of seawater impurities in the pipeline, and the flow of the subsequent section of the pipeline or the tail of the pipe remains unchanged;

[0009] Step a2, leak point location: The pressure gauge is divided into several groups according to the number of pipelines to be monitored. Each group includes four pressure sensors arranged on the pipeline section, namely: 12 The first pressure sensor and the second pressure sensor are arranged at the end of the pipeline along the direction of the coastal water flow with a spacing of d 34 The third and fourth pressure sensors are used; after the leakage is confirmed and the flow rate tends to be stable, the average pressures p1, p2, p3, and p4 of the first, second, third, and fourth pressure sensors over a period of time are collected respectively; the distance x0 between the leakage point and the pipe head is solved by the following formula:

[0010] In a further improvement or preferred embodiment of the above-mentioned ship seawater pipeline leakage diagnosis system, the PLC controller determines the leakage and locates the leakage position based on the following method:

[0011] Measure the pressure signal p￠ at the beginning and end of the pipeline m (t) and p n ￠(t);

[0012] Respectively expressed as

[0013] where t m ,t n is the delay of the signal reaching both ends, α and β refer to the signal attenuation factor, δ m (t),δ n (t) refers to the noise signal, and p(t) refers to the leakage signal;

[0014] By time-shifting the signal formula, we can obtain

[0015] Based on the generalized cross-correlation function, the above formula can be solved to obtain the signal delay Δt=t n -t m ;

[0016] According to the transmission process of the negative pressure wave signal, determine the distance D between the leakage point and the pressure measurement point at the head of the pipe. x Expression: D x =0.5×(D+v×Dt).

[0017] A further improvement or preferred implementation of the aforementioned ship seawater pipeline leakage diagnosis system is that when the PLC controller 6 detects a leakage, it will immediately trigger the leakage switch valve 5 to achieve rapid closure or adjustment of the pipeline 1, thereby effectively reducing leakage losses and ensuring the safety of the ship; the system is also equipped with an alarm device 8; once a leakage is detected, the alarm device 8 will immediately send an alarm signal to ensure that the leakage problem is discovered and handled in time to avoid serious consequences.

[0018] As a further improvement or preferred implementation of the aforementioned ship seawater pipeline leakage diagnosis system, the touch screen 7 serves as a human-computer interaction interface, which not only displays the pipeline 1 status and leakage diagnosis results in real time, but also provides an intuitive operation control interface, so that the operator can quickly understand the system status and make necessary operational adjustments.

[0019] In a further improvement or preferred embodiment of the above-mentioned ship seawater pipeline leakage diagnosis system, the PLC controller 6 is equipped with a data storage module 9, which is an important part of the system; it is responsible for storing the pipeline 1 operation data, leakage diagnosis results and control instruction execution status, providing comprehensive and accurate data support for system optimization and fault analysis;

[0020] The PLC controller 6 has a built-in adaptive learning module 61; this module can continuously learn and optimize the leakage diagnosis algorithm and control strategy based on historical data and operation records, making the system more intelligent and accurate, and improving the overall performance of the system.

[0021] A further improvement or preferred implementation of the aforementioned ship seawater pipeline leakage diagnosis system, the system provides an interface for integration with other ship systems; through the integrated interface, information sharing and collaborative work with other ship systems can be achieved, thereby improving the overall safety and operational efficiency of the ship and providing comprehensive technical support for ship operations.

[0022] Its beneficial effects are:

[0023] The ship seawater pipeline leakage diagnosis system of the present invention is simple to implement and easy to implement. The leakage diagnosis and positioning process is rapid, and can meet the needs of leakage analysis and positioning in various types of ship pipeline systems. It does not require overly complex equipment and can be used as a leakage diagnosis method for various types of base pipelines. It can also be used as a redundant system for existing leakage analysis and diagnosis systems or structures, thereby further improving the effectiveness of leakage diagnosis. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of an implementation method of a ship seawater pipeline leakage diagnosis system;

[0025] Figure 2 This is a schematic diagram of the change of flow rate over time before and after the leakage occurs;

[0026] Figure 3 It is a schematic diagram showing the change of the pressure inside the pipe as the distance between the pipe and the leakage point changes. DETAILED DESCRIPTION

[0027] The present invention is described in detail below in conjunction with specific embodiments.

[0028] like Figure 1 As shown, an embodiment of the present invention provides a ship seawater pipeline 1 leakage diagnosis system, which adopts a layered design and consists of an equipment layer and a control layer; the equipment layer is equipped with a pipeline 1, a flow meter 2, a pressure gauge, a water tank 3, a centrifugal pump 4 and a leakage switch valve 5 to ensure the integrity of the pipeline 1 system;

[0029] The control layer integrates a high-performance PLC controller 6 and a touch screen 7 to achieve real-time monitoring, accurate diagnosis and efficient control of pipeline 1 leakage; the flow meter 2 is precisely installed on the pipeline 1, which can monitor the subtle changes in seawater pressure in real time and transmit real-time data to the PLC controller 6; the PLC controller 6 analyzes the pressure data to determine whether the pipeline 1 leaks to ensure timely response. When the PLC controller 6 determines that a leak has occurred, it will immediately trigger the leakage switch valve 5 to achieve rapid closure or adjustment of the pipeline 1, thereby effectively reducing leakage losses and ensuring the safety of the ship.

[0030] The system firstly lays out the seawater pipelines reasonably according to the actual conditions of the ship1. The pipeline layout should ensure uniform pressure distribution, reasonable pressure drop, and minimize components prone to leakage such as elbows and valves. At the same time, the pipelines should be made of corrosion-resistant and high-pressure resistant materials to improve their service life and safety;

[0031] The flow meter 2 is installed at the head end of the pipeline to be tested to monitor the change of seawater flow in real time. The pressure gauge is installed at the head and tail ends of the pipeline to be tested to monitor the subtle changes of seawater pressure in real time. The flow meter and pressure gauge should have the characteristics of high precision, high reliability and fast response to ensure that the system can accurately obtain pipeline pressure data.

[0032] The system is equipped with a water tank 3 and a centrifugal pump 4 to provide a stable water flow for the pipeline. The water tank should have sufficient capacity to meet the water demand of the ship under different working conditions. The centrifugal pump should have the characteristics of high efficiency, low noise, and low vibration to ensure the stable operation of the pipeline; a key leakage switch valve 5 is set on the pipeline to quickly close or adjust the pipeline when a leak is detected. The leakage switch valve should have the characteristics of fast response, high reliability and easy operation to ensure that the leakage source can be cut off in time in an emergency;

[0033] The control layer uses a high-performance PLC controller 6 as the core control unit. The PLC controller has powerful data processing capabilities and flexible logic control functions. It can receive the pressure data transmitted by the pressure gauge in real time and use a preset algorithm to analyze the pressure data to accurately determine whether the pipeline is leaking. At the same time, the PLC controller is also responsible for controlling the action of the leakage switch valve to achieve rapid closure or adjustment of the pipeline;

[0034] First, it is necessary to confirm that a leak has occurred. Based on the fluid pipeline model, under normal circumstances, the pressure value at a fixed collection point fluctuates around a certain value point. After a leak occurs, the pressure in the pipe will continue to drop, and after a period of time, it will return to the original value point. In order to improve the detection efficiency and simplify the monitoring process, a flow meter is set at the head end of the pipeline for monitoring. When a leak occurs, the pipeline flow changes as follows: Figure 3 As shown, through continuous monitoring, the average flow rate Q after the sudden increase is calculated within the time difference Δt when the flow rate increases suddenly. t Whether the difference between the average flow rate Q0 before the mutation exceeds the empirical threshold can be used to determine whether a leak has occurred. Based on the above principle, the PLC controller of this application determines the leak and locates the leak in the following way:

[0035] Step a1, leakage judgment: Continuously detect the flow change at the head end of the pipeline to detect whether there is a sudden increase in flow. If so, compare the average flow Q after the sudden increase. t The difference between the average flow rate Q0 before the mutation ΔQ = Q t -Whether Q0 exceeds the empirical threshold Q￠, if it exceeds, it means that leakage has occurred, if it does not exceed, then no processing will be done, such as Figure 2As shown in the figure, if there is a sudden decrease in the flow at the head end of pipeline 1, it is necessary to conduct a leakage analysis on the previous section of pipeline 1. The empirical threshold Q￠ is obtained by analyzing the historical leakage data of the current pipeline, and is generally not lower than the average flow Q after the sudden increase in the historical leakage data. t Compared with the minimum value of the average flow Q0 before the mutation, due to the hysteresis of pipeline flow, when necessary, it can also be assisted by judging whether the duration of the sudden increase in flow is within a reasonable time period. If the mutation period is very short, it indicates that it may be caused by the movement of seawater impurities in the pipeline, and the flow of the subsequent section of the pipeline or the tail of the pipe remains unchanged;

[0036] After a leak occurs, the fluid loss at the leak point will cause the flow rate before and after the leak point to change. Based on the actual situation, in a normal pipeline without leakage, due to the resistance in the pipe and the compression of the fluid, the water pressure in the pipe gradually decreases along the direction of the fluid, while the flow rate in the pipe at different positions remains unchanged. When a leak occurs in a certain area of ​​pipeline 1, the seawater in the pipe directly decreases before and after the leak position, the flow rate will drop linearly, and the pressure curve in the pipe will show a steep drop at the leak point. For example, Figure 2 As shown; To ensure that the PLC controller 6 can effectively analyze the leakage status in the pipe, the pressure gauge in this application is divided into several groups according to the number of pipelines 1 to be monitored, each group includes four pressure sensors arranged on the pipeline section, including one arranged at the head end of the pipeline along the coastal water flow direction with a spacing of d 12 The first pressure sensor and the second pressure sensor are arranged at the end of the pipeline along the direction of the coastal water flow with a spacing of d 34 The third pressure sensor and the fourth pressure sensor;

[0037] Through analysis, it can be seen that the gradient of the fluid pressure measured between the two pressure gauges near the pipeline can be expressed as

[0038] Where x represents the distance between the measuring point and the pipe head, x0 represents the distance between the leakage point and the pipe head, D is the length of the pipeline, p1, p2, p3, and p4 are the fluid pressures in the pipe measured by the first pressure sensor, the second pressure sensor, the third pressure sensor, and the fourth pressure sensor respectively; their distribution is as follows: Figure 3 As shown, the specific steps are as follows:

[0039] Step a2, leak point location: After the leak is confirmed and the flow rate tends to be stable, the average pressures p1, p2, p3, and p4 of the first pressure sensor, the second pressure sensor, the third pressure sensor, and the fourth pressure sensor over a period of time are collected respectively; the distance x0 between the leak point and the pipe head is solved by the following formula:

[0040]

[0041] In particular, the above scheme is suitable for the situation where the flow rate in the pipeline changes slowly and the leakage at the leakage point is relatively large. Although it can meet the analysis and positioning needs of leakage in most ship pipelines, it is not possible to accurately determine the occurrence of leakage and the accurate location of the leakage point for some pipelines with long lengths or complex pipeline structures. Therefore, for this situation, on the basis of the above, it is necessary to further analyze and process the specific leakage situation. Specifically:

[0042] After a pipeline leak occurs, a negative pressure wave signal will be generated and propagated to both ends of the pipeline at a uniform speed. By analyzing the time difference between the negative pressure wave signals reaching both ends, the specific location of the leak can be determined. Since the negative pressure wave signal is less susceptible to interference and has a long propagation distance, the leak location can be better located.

[0043] To confirm the negative pressure wave signal, pressure sensors need to be installed on both sides of the pipeline;

[0044] For the pressure signal p￠ measured at the beginning and end of the pipeline m (t) and p n ￠(t) can be expressed as

[0045]

[0046] where t m ,t n is the delay of the signal reaching both ends, α and β refer to the signal attenuation factor, δ m (t),δ n (t) refers to the noise signal, p(t) refers to the leakage signal; to obtain the signal delay Δt = t n -t m , time-shift the signal formula to obtain Based on the generalized cross-correlation function, the above formula can be solved to obtain the signal delay Δt; further, according to the transmission process of the negative pressure wave signal, the distance D between the leakage point and the pressure measurement point at the pipe head can be determined. x =0.5×(D+v×Dt); where v refers to the propagation speed of the negative pressure wave signal; D is the length of the pipeline;

[0047] In this embodiment, the model of the pressure gauge is ROTAMASS RCCT34, the model of the PLC controller is Siemens PLCS7-200CPU224XP, and the model of the touch screen is Weiluntong TK6070i;

[0048] Furthermore, the touch screen 7, as a human-machine interaction interface, not only displays the status of the pipeline 1 and the leakage diagnosis results in real time, but also provides an intuitive operation control interface, so that the operator can quickly understand the system status and make necessary operational adjustments.

[0049] The system is equipped with a touch screen 7 as a human-machine interface. The touch screen can display the operation status of the pipeline, the leakage diagnosis results, the execution of control instructions and other information in real time. At the same time, the operator can also perform operations such as parameter setting, mode selection and troubleshooting through the touch screen, which improves the flexibility and convenience of the system.

[0050] Furthermore, the system is also equipped with an alarm device 8; once a leak is detected, the alarm device 8 will immediately send out an alarm signal to ensure that the leak problem is discovered and dealt with in time to avoid serious consequences.

[0051] The system is also equipped with an alarm device 8 for sending an alarm signal when a leak is detected. The alarm device should have high sensitivity, high reliability and multiple alarm modes such as sound, light, etc. to ensure that the leak problem can be discovered and handled in time.

[0052] Furthermore, the PLC controller 6 is equipped with a data storage module 9, which is an important component of the system; it is responsible for storing the pipeline 1 operation data, leakage diagnosis results and control instruction execution status, providing comprehensive and accurate data support for system optimization and fault analysis.

[0053] The PLC controller has a built-in data storage module 9 for storing information such as pipeline operation data, leakage diagnosis results, and control instruction execution status. The data storage module should have the characteristics of large capacity, high reliability, and easy query, providing comprehensive and accurate data support for system optimization and fault analysis.

[0054] Furthermore, the system also includes a remote control module 10, through which the operator can monitor and operate the ship seawater pipeline 1 leakage diagnosis and control system in real time from a remote location, thereby improving the flexibility and convenience of the system and being suitable for various complex ship operation scenarios; the PLC controller 6 is equipped with an adaptive learning module 61; the module can continuously learn and optimize the leakage diagnosis algorithm and control strategy based on historical data and operation records, making the system more intelligent and accurate, and improving the overall performance of the system; the system provides an interface for integration with other ship systems; through the integrated interface, information sharing and collaborative work with other ship systems can be achieved, thereby improving the overall safety and operational efficiency of the ship and providing comprehensive technical support for ship operations; the system fully considers the particularity and complexity of the ship environment in design and implementation; regardless of whether it is in harsh environments such as high temperature, high humidity or vibration, the system can operate stably to ensure reliable protection for the ship under various working conditions; the system is also highly scalable and customizable; users can customize and expand it according to actual needs to meet the specific needs of different ships and provide more flexible and personalized solutions for ship operations.

[0055] The system provides an interface for integration with other ship systems, which can realize information sharing and collaborative work with other ship systems. This function improves the overall safety and operational efficiency of the ship and provides comprehensive technical support for ship operations.

[0056] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention, rather than to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the present invention.

Claims

1. A ship seawater pipeline leakage diagnosis system, characterized in that: It includes an equipment layer and a control layer; the equipment layer is equipped with pipelines (1), flow meters (2), pressure gauges, water tanks (3), centrifugal pumps (4) and leakage switch valves (5); the control layer is equipped with a PLC controller (6) and a touch screen (7); The flow meter (2) is installed at the head end of the pipeline to be tested, and is used to monitor the change of seawater flow in real time. The pressure meter is installed at the head and tail ends of the pipeline to be tested, and is used to monitor the slight change of seawater pressure in real time.

2. The ship seawater pipeline leakage diagnosis system according to claim 1, characterized in that: The PLC controller determines the leak and locates the leak based on the following: Step a1, leakage judgment: Continuously detect the flow change at the head end of the pipeline to detect whether there is a sudden increase in flow. If so, compare the average flow Q after the sudden increase. t The difference between the average flow rate Q0 before the mutation ΔQ = Q t -Whether Q0 exceeds the empirical threshold Q￠. If it exceeds, it means leakage occurs. If it does not exceed, no treatment will be given. If a sudden decrease in flow occurs at the head end of the pipeline, it is necessary to conduct a leakage analysis on the previous section of the pipeline. The empirical threshold Q￠ is obtained by analyzing the historical leakage data of the current pipeline, and is generally not lower than the average flow Q after a sudden increase in the historical leakage data. t Compared with the minimum value of the average flow Q0 before the mutation, due to the hysteresis of pipeline flow, when necessary, it can also be assisted by judging whether the duration of the sudden increase in flow is within a reasonable time period. If the mutation period is very short, it indicates that it may be caused by the movement of seawater impurities in the pipeline, and the flow of the subsequent section of the pipeline or the tail of the pipe remains unchanged; Step a2, leak point location: The pressure gauge is divided into several groups according to the number of pipelines to be monitored. Each group includes four pressure sensors arranged on the pipeline section, namely: 12 The first pressure sensor and the second pressure sensor are arranged at the end of the pipeline along the direction of the coastal water flow with a spacing of d 34 The third and fourth pressure sensors are used; after the leakage is confirmed and the flow rate tends to be stable, the average pressures p1, p2, p3, and p4 of the first, second, third, and fourth pressure sensors over a period of time are collected respectively; the distance x0 between the leakage point and the pipe head is solved by the following formula:

3. The ship seawater pipeline leakage diagnosis system according to claim 1, characterized in that: The PLC controller determines the leak and locates the leak based on the following: Measure the pressure signal p￠ at the beginning and end of the pipeline m (t) and p n ￠(t); Respectively expressed as where t m ,t n is the delay of the signal reaching both ends, α and β refer to the signal attenuation factor, δ m (t),δ n (t) refers to the noise signal, and p(t) refers to the leakage signal; By time-shifting the signal formula, we can obtain Based on the generalized cross-correlation function, the above formula can be solved to obtain the signal delay Δt=t n -t m ; According to the transmission process of the negative pressure wave signal, determine the distance D between the leakage point and the pressure measurement point at the head of the pipe. x Expression: D x =0.5×(D+v×Dt).

4. The ship seawater pipeline leakage diagnosis system according to claim 1, characterized in that: When the PLC controller (6) detects a leak, it will immediately trigger the leak switch valve (5) to quickly close or adjust the pipeline (1), thereby effectively reducing leakage losses and ensuring the safety of the ship. The system is also equipped with an alarm device (8). Once a leak is detected, the alarm device (8) will immediately send out an alarm signal to ensure that the leak problem is discovered and handled in a timely manner to avoid serious consequences.

5. The ship seawater pipeline leakage diagnosis system according to claim 1, characterized in that: The touch screen (7) serves as a human-machine interaction interface, which not only displays the status of the pipeline (1) and the leakage diagnosis results in real time, but also provides an intuitive operation control interface, so that the operator can quickly understand the system status and make necessary operation adjustments.

6. The ship seawater pipeline leakage diagnosis system according to claim 1, characterized in that: The PLC controller (6) is equipped with a data storage module (9), which is an important component of the system; it is responsible for storing pipeline (1) operation data, leakage diagnosis results and control instruction execution status, and provides comprehensive and accurate data support for system optimization and fault analysis; The PLC controller (6) is built with an adaptive learning module (61); the module can continuously learn and optimize the leakage diagnosis algorithm and control strategy based on historical data and operation records, making the system more intelligent and accurate, and improving the overall performance of the system.

7. The ship seawater pipeline leakage diagnosis system according to claim 1, characterized in that: The system provides an interface for integration with other ship systems; through the integrated interface, information sharing and collaborative work with other ship systems can be achieved, improving the overall safety and operational efficiency of the ship and providing comprehensive technical support for ship operations.

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