Ship pipeline leakage detection and positioning method based on optimization algorithm

Abstract

The invention discloses a ship pipeline leakage detecting and positioning method based on an optimization algorithm, and belongs to the technical field of thermal power generating unit monitoring. In the ship pipeline leakage detecting and positioning method, various data acquisition modules are arranged, and an infrared thermal imager can also be used for measuring the temperature of a working medium pipeline of a ship pipeline and serves as a basis for judging whether heat preservation reaches a specified effect or not; the sealing position of the flange is prone to leakage, the thermal infrared imager can be used for monitoring heat preservation of the boiler shell so as to reduce heat dissipation loss, a high-temperature point on the outer wall of the boiler can be found, the high-temperature point indicates the failure position of the refractory layer, and therefore the situation that the process efficiency is reduced due to heat loss is avoided. The alarm module is arranged, when the information acquisition module monitors that the working medium of the ship pipeline leaks, the multiple alarm modules in the alarm module can send out broadcast voice through the broadcast voice alarm module to remind more workers to pay attention to maintenance, and the overall safety and reliability of the system are improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of ship pipeline detection, and particularly relates to a ship pipeline leakage detection and positioning method based on an optimization algorithm. BACKGROUND

[0002] Ship pipeline working medium leakage detection is an important technical means for guaranteeing safe operation of a ship and environmental protection, and is mainly used for monitoring abnormal leakage of liquid or gaseous medium in various pipeline systems of the ship. The pipeline system on the ship is widely distributed in key parts such as a power system, a fuel system, a cooling system, a ballast system and a fire extinguishing system. Once leakage occurs, serious consequences such as fire, explosion, environmental pollution or equipment damage may be caused. Therefore, modern ships generally adopt various detection technologies such as infrared thermal imaging, gas sensors, acoustic emission detection, pressure change monitoring and optical fiber sensing to realize real-time monitoring and early warning of pipeline leakage. The leakage detection system is usually integrated into a comprehensive monitoring platform of the ship, has the functions of automatic alarm, positioning and data recording, and provides timely and accurate information support for the ship operator, and is an important guarantee measure for improving the safety, reliability and environmental protection performance of the ship.

[0003] However, the common detection method has a single data acquisition method, so that the accuracy of the whole detection is not high enough. SUMMARY

[0004] The purpose of the present application is to solve the above-mentioned problems, and to provide a ship pipeline leakage detection and positioning method based on an optimization algorithm.

[0005] The technical scheme adopted by the present application is as follows: a ship pipeline leakage detection and positioning method based on an optimization algorithm, comprising the following steps:

[0006] S1: first set a ship pipeline working medium leakage data acquisition module, and the data acquisition module is composed of an infrared thermal imager, a ship pipeline working medium flow state monitoring module, a distributed optical fiber temperature measurement host and a distributed temperature measurement optical fiber;

[0007] S2: the temperature measurement control host can be connected to a PC through a communication interface for display. The temperature trajectory of the optical cable can be displayed in real time on the PC, the alarm signal can be highlighted, and the actual position of the damaged point of the optical cable can be determined and displayed. When the optical cable is damaged, the system can timely locate the damaged point and fuse it through an optical fiber fusion machine;

[0008] S3: set an infrared thermal imager to safely monitor ship pipeline working medium leakage. The infrared thermal imager can more directly find out whether the thermal insulation layer of the ship pipeline working medium pipeline is damaged or leaked. If the thermal insulation layer of the ship pipeline working medium pipeline falls off, the temperature difference at the falling-off position is large, and the falling-off position can be clearly displayed in a thermal image;

[0009] S4: Set up a pressure sensor to monitor the ship pipeline working fluid flow state, and paste the piezoelectric pressure sensor on the ship pipeline working fluid pipeline to collect the pressure signal on the ship pipeline working fluid pipeline;

[0010] S5: Establish a ship pipeline working fluid flow calculation model, according to the ship pipeline working fluid flow change of the ship pipeline working fluid pipeline, establish the corresponding model, when the ship pipeline working fluid pipeline leaks, ignore the medium influence of the fluid flow in the ship pipeline working fluid pipeline, set the distance of the leakage point from the pipe section head as x, then according to the attenuation change of the ship pipeline working fluid flow, the ship pipeline working fluid flow change model is constructed as follows:

[0011] |Δp x |=|Δp0|e -ηx In the formula: |△p0| represents the pressure drop of water flow at the leakage point of the pipe section; |△p x | represents the pressure drop at a distance x from the leakage point of the pipe section; η represents the flow attenuation coefficient of the ship pipeline working fluid flow away from the leakage point. The pressure sensor is installed at the head and tail of the ship pipeline working fluid pipeline respectively, and when the pressure value of the ship pipeline working fluid pipeline is greater than the minimum pressure value that the pressure sensor can detect, the leakage of the ship pipeline working fluid pipeline can be successfully monitored;

[0012] S6: The data transmission module transmits the collected information, and the data transmission module uses the WirelessHART communication node to transmit the related information;

[0013] S7: After the data transmission module transmits the data to the software of the external leakage monitoring platform, the distributed optical fiber temperature measurement monitoring system, the infrared thermal imaging temperature measurement system and the ship pipeline working fluid flow state monitoring module are controlled and managed, if the pipeline has abnormal condition, whether the alarm information of the distributed optical fiber temperature measurement monitoring system or the infrared thermal imaging temperature measurement system or the ship pipeline working fluid flow state information will be prompted on the platform;

[0014] S8: When the ship pipeline working fluid leaks, the alarm module is started, at this time the telephone alarm module set up starts to broadcast the number to the relevant maintenance personnel for alarm, and at the same time the related broadcast voice alarm module is started, so as to remind more workers to deal with the leakage situation in time, and then the whole ship pipeline working fluid leakage online measurement process is ended;

[0015] S9: Time and space registration of temperature anomaly points of the integrated distributed optical fiber temperature measurement system, leakage area thermograph of the infrared thermal imager, and pressure drop data of the first and last end pressure sensors, solving the flow change model using an improved particle swarm optimization algorithm, fusing multi-source data with the positioning error minimized as the objective function, finally outputting the leakage point location accurate to ±0.2 meters and the confidence evaluation result, and displaying the specific coordinates on the PC end and generating a positioning report;

[0016] S9.1 Time and space registration of multi-source data:

[0017] The external leakage monitoring platform software performs time and space synchronization on the temperature anomaly point coordinates (accurate to meters) collected by the distributed optical fiber temperature measurement system, the leakage area thermograph (pixel level coordinates) photographed by the infrared thermal imager, and the pressure drop data (△p0,△px) of the first and last end pressure sensors, and establishes a multi-source data set in a unified coordinate system.

[0018] S9.2 Solving of the positioning model based on the optimization algorithm:

[0019] An improved particle swarm optimization (PSO) algorithm is used to optimize the parameters of the flow change model in step S5, with the positioning error minimized as the objective function:

[0020]

[0021] x^fiber: distance of the leakage point directly located by the distributed optical fiber temperature measurement system;

[0022] x^pressure: distance of the leakage point calculated based on the pressure drop model (formula: );

[0023] x^IR: projection distance of the center of the temperature difference area identified by the infrared thermal imager on the pipeline;

[0024] α,β,γ: weight coefficients (dynamically adjusted according to sensor accuracy, such as optical fiber positioning weight set to 0.5, pressure model 0.3, and infrared 0.2).

[0025] S9.3 Output of the positioning result and confidence evaluation:

[0026] After the algorithm converges, the final position xx of the leakage point (accurate to ±0.2 meters) is output, and the confidence index (such as error probability <5%) is calculated. The result is displayed on the PC end monitoring interface in the form of "pipeline number + distance from the first end XX meters + three-dimensional coordinates", and a positioning report (including comparison curves of various sensor data) is generated for reference by maintenance personnel.

[0027] Through multi-source data fusion and optimization algorithm iteration, the problem of single sensor positioning ambiguity (such as optical fiber interference by environmental temperature, pressure model ignoring local resistance) can be solved, and the positioning accuracy of the leakage point can be improved.

[0028] In the step S1, the distributed optical fiber temperature measuring host is the main body of the optical fiber system, which is responsible for signal collection, signal processing, data analysis, over-temperature alarm, network transmission and other functions of the whole ship pipeline working medium leakage measuring system. The optical fiber temperature measuring host can realize long-distance temperature detection along the pipeline with high positioning accuracy, without dead angle and blind area, and can accurately detect each temperature point along the pipeline and accurately locate it. The distributed temperature measuring optical fiber mainly performs distributed real-time online monitoring on the ship pipeline working medium leakage between the boiler and the Christmas tree. By linearly laying the temperature sensing optical cable along the pipeline, the temperature distribution around the pipeline is monitored in real time. When the temperature of the local pipeline of the ship pipeline working medium pipeline is abnormal, the distributed optical fiber temperature measuring system can timely capture the abnormality, display and alarm on the temperature curve, and locate the position information of the abnormal point.

[0029] In the step S1, the principle of the distributed temperature measuring optical fiber is to obtain the temperature information of the optical fiber based on the Brillouin / Raman optical time domain analysis technology, and to provide a spatial resolution index. The distributed temperature sensing of the optical fiber is mainly realized by using the optical time domain reflection (OTDR) technology and the temperature effect of the backscattering Brillouin scattering / Raman scattering of the optical fiber. The leakage monitoring host utilizes the leakage monitoring special optical cable to perform real-time online monitoring on the temperature field gradient along the axial line of the ship pipeline working medium pipeline. The leakage monitoring host scans and records the temperature field gradient value at a high sampling interval (up to 0.25m) and a high frequency. When the temperature difference or the temperature rise / drop rate exceeds the set threshold, the system will immediately issue an alarm. According to the optical time domain reflection technology (OTDR), the position of the temperature measuring field mutation point on the optical fiber can be accurately determined by using the travel time of the backscattering light.

[0030] In the step S3, the infrared thermal imaging camera monitors the key areas such as the Christmas tree of the ship pipeline working medium, the ship pipeline working medium flange valve and the ship pipeline working medium boiler shell for 24 hours. Through software analysis algorithm, the temperature anomaly is automatically alarmed. The infrared thermal imaging temperature measurement technology can preview the video of the infrared monitoring point, and can present the temperature of the point in the real-time picture. The temperature measurement thermal imaging camera can perform line temperature measurement, frame temperature measurement and point temperature measurement on the monitoring scene at the front end of the ship pipeline working medium in real time. The temperature measurement range is 0-550℃. The temperature measurement accuracy is ±2℃ or ±2% of the range (the maximum value).

[0031] The step S4, the HL-8 piezoelectric pressure sensor selected by the present application can work normally in the ship pipeline working medium measurement environment, can collect information in the ship pipeline working medium pipeline, and can effectively output. In addition, in the noise environment existing in the ship pipeline working medium pipeline operation, the range determination of the sensor can ensure that all values exceeding the ship pipeline working medium pipeline pressure are ensured, and the corresponding error problem is avoided. And the sensor has high precision, can ensure that the signal transmission is in a stable range, and accurately collects the change of the ship pipeline working medium flow state in the ship pipeline working medium pipeline.

[0032] The step S4, the pressure signal appearing at the leakage point of the ship pipeline working medium pipeline. When the ship pipeline working medium pipeline leaks, the water flow will overflow, and the leakage or injection phenomenon will occur, but the pressure change in the early stage is relatively sharp. This change of pressure will also propagate in two directions of the ship pipeline working medium pipeline, so that it can be detected by the pressure sensor installed on the ship pipeline working medium pipeline, so as to obtain the information of the ship pipeline working medium flow. The liquid flow process in the ship pipeline working medium pipeline is as follows:

[0033]

[0034] In the formula, ρ represents the density of the water body inside the ship pipeline working medium pipeline; v represents the conventional flow rate of the fluid inside the ship pipeline working medium pipeline; t represents the detection time of the ship pipeline working medium flow state; and x represents the axial distance along the ship pipeline working medium pipeline.

[0035] The step S6, the WirelessHART communication module conforms to the wireless communication specification of HART7.6 protocol, which is the core part of the WirelessHART field device, and is compatible with the ultra-wideband wireless transceiver of IEEE802.15.4 protocol. The monitoring system arranges 6 nodes and 1 gateway in an area, and the gateway is responsible for the details of node networking. The arrangement of nodes conforms to the spatial distribution and can facilitate the construction of a robust mesh network. The sensor detection module is combined with the WirelessHART module to realize ultrasonic wave and temperature detection and transmission to the upper computer. Then, the leakage level and leakage amount are obtained by using the ultrasonic wave detection mathematical model. After the node deployment is completed, the gateway communicates with each detection node in the specified area to complete the network initialization and networking work.

[0036] The step S7, if the distributed optical fiber alarms in a certain defense area, the infrared thermal imaging camera matched with the defense area will be popped out to review the temperature of the position. If the alarm signals of the two monitoring systems are reviewed each other, the possibility of leakage at this position will be significantly improved.

[0037] In the step S8, the telephone alarm module selects the DTMF two-way receiving / transmitting integrated circuit MT8880, which is specially designed for the receiving and transmitting of the DTMF signal, and can generate and receive the DTMF signal, and can also judge various signal tones (dial tone, ring back tone, busy tone); the chip is set to the DTMF mode and the interrupt mode, and whether the DTMF signal is received can be judged through the IRQ pin; the DTMF instruction is input into the MT8880 through T1, C1 and R3 for decoding, and the decoded instruction is input into the P2 port of the single-chip microcomputer U4 for processing; when the alarm monitoring signal of a certain path is valid, the system prompts, the P2 port outputs the telephone number and the control signal, the DTMF signal is converted into the DTMF signal through the U3 and is output from the 8th pin, is amplified through R17, R16, C4, R12 and Q2, is coupled to the telephone line through T1, and the telephone is dialed, and two telephones are dialed in turn according to the "alarm mode" to alarm; the broadcast voice alarm module selects the finished board XY-V17B, the voice content is stored in the TF card in advance, the file name is named according to the following table, and the level combination playing mode is P0 port output control signal for corresponding voice broadcast, and the voice is amplified through C6, R10 and Q2, and is coupled to the telephone line through T1. According to the length of each voice time, the playing times of each voice can be controlled and the playing is stopped at the end of each voice.

[0038] In summary, due to the adoption of the above technical solutions, the present application has the following advantages:

[0039] 1. In the present application, a plurality of data acquisition modules are provided, and the infrared thermal imager can also be used to measure the temperature of the working fluid pipeline of the ship pipeline and use it as a basis for judging whether the heat preservation achieves the specified effect. Leakage is prone to occur at the flange sealing position, and it can be directly observed by the thermal imager, thereby avoiding the risk of burns during on-site inspection. The infrared thermal imager can be used to monitor the heat preservation of the boiler shell to reduce heat loss and can also find high-temperature points on the outer wall of the boiler, which indicate the position of the failed refractory layer, thereby avoiding the reduction of process efficiency caused by heat loss.

[0040] 2. In the present application, the temperature anomaly points of the distributed optical fiber temperature measurement system, the thermal image of the leakage area of the infrared thermal imager, and the pressure drop data of the first and last end pressure sensors are integrated for space-time registration, and an improved particle swarm optimization algorithm is used to solve the flow change model, thereby significantly improving the comprehensive performance of ship pipeline leakage detection and positioning. The fusion application of multi-source data avoids the limitations of single sensor monitoring. For example, the distributed optical fiber temperature measurement system can accurately capture temperature mutation points, the infrared thermal imager can directly display the temperature difference in the leakage area, and the pressure sensor can reflect flow anomalies through pressure drop changes. The three work together to significantly reduce the false alarm risk caused by environmental interference, ensuring the comprehensiveness and reliability of the leakage state monitoring.

[0041] 3、In the application, the introduction of the optimization algorithm realizes the breakthrough of positioning accuracy, fuses the data of each sensor with the target function of minimizing the positioning error, controls the position error of the leakage point within ±0.2 meters, and outputs the confidence evaluation result, thereby providing a quantitative decision basis for the maintenance personnel, and solving the problems of traditional methods, such as fuzzy positioning and large error. The system performs outstandingly in fault tolerance and continuity, the distributed optical fiber temperature measurement system can automatically locate and repair the damaged point through the optical fiber fusion machine, and the pressure sensor monitors the pipeline pressure state in real time, so that the stable operation of the overall monitoring process can be maintained even if a local module fails. The intelligent design of the alarm mechanism and data management further improves the practical value, the combination of telephone alarm and broadcast voice module ensures that the maintenance personnel respond quickly, the PC end displays the leakage point coordinates in real time and generates a positioning report, realizes efficient cooperation of the whole process from leakage detection, accurate positioning to notification processing, effectively shortens the fault handling time, reduces the risk of accident expansion, and improves the intelligent and fine level of ship pipeline leakage detection. BRIEF DESCRIPTION OF DRAWINGS

[0042] Figure 1 The flowchart of the application;

[0043] Figure 2 The structural schematic diagram of the wirelessHART network. DETAILED DESCRIPTION

[0044] In order to make the purpose, technical scheme and advantages of the application more clear and understandable, the application will be further described in detail below in combination with the drawings and examples. It should be understood that the specific examples described herein are only used to explain the application and not to limit the application.

[0045] A ship pipeline leakage detection and positioning method based on an optimization algorithm, comprising the following steps:

[0046] S1: first set the ship pipeline working medium leakage data acquisition module, the data acquisition module is composed of an infrared thermal imager, a ship pipeline working medium flow state monitoring module, a distributed optical fiber temperature measurement host and a distributed temperature measurement optical fiber;

[0047] S2: the temperature control host can be connected with the PC through the communication interface for display. The temperature trajectory of the optical cable can be displayed in real time on the PC, the alarm signal can be highlighted, and the actual position of the damaged optical cable can be determined and displayed. When the optical cable is damaged, the system can timely locate the damaged point and repair it through the optical fiber fusion machine;

[0048] S3: set the infrared thermal imager to safely monitor the ship pipeline working medium leakage, the infrared thermal imager can more directly find out whether the thermal insulation layer of the ship pipeline working medium pipeline is damaged or leaked, the thermal insulation of the ship pipeline working medium pipeline falls off, the temperature difference at the falling-off position is large, and the falling-off position can be clearly displayed in the thermal image.

[0049] S4: setting a pressure sensor to monitor the working fluid flow state of the ship pipeline, and attaching a piezoelectric pressure sensor to the working fluid pipeline of the ship pipeline to collect the pressure signal on the working fluid pipeline of the ship pipeline;

[0050] S5: establishing a ship pipeline working fluid flow calculation model, according to the ship pipeline working fluid flow change of the ship pipeline working fluid pipeline, establishing a corresponding model, when the ship pipeline working fluid pipeline leaks, ignoring the medium influence of the fluid flow in the ship pipeline working fluid pipeline, setting the distance of the leakage point from the head of the pipe section as x, then according to the attenuation change of the ship pipeline working fluid flow, the ship pipeline working fluid flow change model is constructed as follows:

[0051] |Δp x |=|Δp0|e -ηx In the formula: |△p0| represents the pressure drop of water flow at the leakage point of the pipe section; |△p x | represents the pressure drop at a distance x from the leakage point of the pipe section; η represents the flow attenuation coefficient of the ship pipeline working fluid flow away from the leakage point. The pressure sensor is installed at the head and tail of the ship pipeline working fluid pipeline respectively, and when the pressure value of the ship pipeline working fluid pipeline is greater than the minimum pressure value that the pressure sensor can detect, the leakage of the ship pipeline working fluid pipeline can be successfully monitored;

[0052] S6: the data transmission module transmits the collected information, and the data transmission module uses the WirelessHART communication node to transmit the related information;

[0053] S7: after the external leakage monitoring platform software receives the data transmitted by the data transmission module, the distributed optical fiber temperature measurement monitoring system, the infrared thermal imaging temperature measurement system and the ship pipeline working fluid flow state monitoring module are controlled and managed, if the pipeline has an abnormal condition, whether it is the alarm information of the distributed optical fiber temperature measurement monitoring system or the infrared thermal imaging temperature measurement system or the ship pipeline working fluid flow state information, it will be prompted on the platform;

[0054] S8: when the ship pipeline working fluid leaks, the alarm module is started, at this time the telephone alarm module set starts to broadcast the number to the relevant maintenance personnel for alarm, and at the same time the related broadcast voice alarm module is started, so as to remind more workers to handle the leakage situation in time, and then the whole ship pipeline working fluid leakage online measurement process is ended.

[0055] S9: Time and space registration of temperature anomaly points of the integrated distributed optical fiber temperature measurement system, leakage area thermograph of the infrared thermal imager, and pressure drop data of the first and last end pressure sensors, solving the flow change model using an improved particle swarm optimization algorithm, fusing multi-source data with the positioning error minimized as the objective function, finally outputting the leakage point location accurate to ±0.2 meters and the confidence evaluation result, and displaying the specific coordinates on the PC end and generating a positioning report;

[0056] S9.1 Time and space registration of multi-source data:

[0057] The external leakage monitoring platform software performs time and space synchronization on the temperature anomaly point coordinates (accurate to meters) collected by the distributed optical fiber temperature measurement system, the leakage area thermograph (pixel level coordinates) photographed by the infrared thermal imager, and the pressure drop data (△p0,△px) of the first and last end pressure sensors, and establishes a multi-source data set in a unified coordinate system.

[0058] S9.2 Solving of the positioning model based on the optimization algorithm:

[0059] An improved particle swarm optimization (PSO) algorithm is used to optimize the parameters of the flow change model in step S5, with the positioning error minimized as the objective function:

[0060]

[0061] x^fiber: distance of the leakage point directly located by the distributed optical fiber temperature measurement system;

[0062] x^pressure: distance of the leakage point calculated based on the pressure drop model (formula: );

[0063] x^IR: projection distance of the center of the temperature difference area identified by the infrared thermal imager on the pipeline;

[0064] α,β,γ: weight coefficients (dynamically adjusted according to sensor accuracy, such as optical fiber positioning weight set to 0.5, pressure model 0.3, and infrared 0.2).

[0065] S9.3 Output of the positioning result and confidence evaluation:

[0066] After the algorithm converges, the final position xx of the leakage point (accurate to ±0.2 meters) is output, and the confidence index (such as error probability <5%) is calculated. The result is displayed on the PC end monitoring interface in the form of "pipeline number + distance from the first end XX meters + three-dimensional coordinates", and a positioning report (including comparison curves of various sensor data) is generated for reference by maintenance personnel.

[0067] Through multi-source data fusion and optimization algorithm iteration, the problem of single sensor positioning ambiguity (such as optical fiber interference by environmental temperature, pressure model ignoring local resistance) can be solved, and the positioning accuracy of the leakage point can be improved.

[0068] In step S1, the distributed optical fiber temperature measuring host is the main body of the optical fiber system, which is responsible for signal acquisition, signal processing, data analysis, over-temperature alarm, network transmission and other functions of the entire ship pipeline working medium leakage measurement system. The optical fiber temperature measuring host can realize long-distance temperature detection along the ship pipeline working medium leakage with high positioning accuracy, no dead angle and no blind area, accurately detecting each temperature point along the line and accurately positioning; the distributed temperature measuring optical fiber mainly performs distributed real-time online monitoring on the ship pipeline working medium leakage between the boiler and the Christmas tree. By linearly laying the temperature sensing optical cable along the ship pipeline working medium pipeline, the temperature distribution around the pipeline is monitored in real time. When the temperature of the local ship pipeline working medium pipeline is abnormal, the distributed optical fiber temperature measuring system can timely capture the abnormality, display and alarm on the temperature curve, and locate the position information of the abnormal point.

[0069] In step S1, the principle of the distributed temperature measuring optical fiber is to obtain the temperature information of the optical fiber based on the Brillouin / Raman optical time domain analysis technology, and to provide a spatial resolution index. The optical fiber distributed temperature sensing is mainly realized by using the optical time domain reflection (OTDR) technology and the temperature effect of the backscattering Brillouin scattering / Raman scattering of the optical fiber. The leakage monitoring host utilizes the leakage monitoring special optical cable to realize real-time online monitoring of the temperature field gradient along the axial line of the ship pipeline working medium pipeline. The leakage monitoring host scans and records the temperature field gradient value at a dense sampling interval (up to 0.25m) and a high frequency. When the temperature difference or temperature rise / drop rate exceeds the set threshold, the system will immediately issue an alarm. According to the optical time domain reflection technology (OTDR), the position of the temperature measurement field mutation point on the optical fiber can be accurately determined by using the travel time of backscattered light.

[0070] In step S3, the infrared thermal imaging camera monitors the key areas of the ship pipeline working medium Christmas tree, ship pipeline working medium flange valve and ship pipeline working medium boiler shell for 24 hours. Through software analysis algorithm, the temperature anomaly is automatically alarmed. The infrared thermal imaging temperature measurement technology can preview the video of the infrared monitoring point, and can present the temperature of the point in the real-time picture. The temperature measurement thermal imaging camera can realize line temperature measurement, frame temperature measurement and point temperature measurement on the monitoring scene at the front end of the ship pipeline working medium in real time. The temperature measurement range is 0-550℃. The temperature measurement accuracy is ±2℃ or ±2% of the range (taking the maximum value).

[0071] In step S4, the HL-8 piezoelectric pressure sensor selected by the present application can work normally in the working fluid measurement environment of the ship pipeline, can collect information in the ship pipeline, and can effectively output. In addition, in the noise environment existing in the ship pipeline working fluid pipeline operation, the range determination of the sensor can ensure that all values exceeding the ship pipeline working fluid pressure are ensured, and the corresponding error problem is avoided. And the sensor has high precision, can ensure that the signal transmission is in a stable range, and accurately collect the change of the ship pipeline working fluid flow state in the ship pipeline.

[0072] In step S4, the pressure signal appears at the leakage point of the ship pipeline working fluid pipeline. When the ship pipeline working fluid pipeline leaks, the water flow will overflow outward, and the leakage or injection phenomenon will occur, but the pressure change in the early stage is relatively sharp. This change of pressure will also propagate in two directions of the ship pipeline working fluid pipeline, so it can be detected by the pressure sensor installed on the ship pipeline working fluid pipeline, so as to obtain the information of the ship pipeline working fluid flow. The liquid flow process in the ship pipeline working fluid pipeline is as follows:

[0073]

[0074] In the formula, ρ represents the density of the water body inside the ship pipeline working fluid pipeline; v represents the conventional flow rate of the fluid inside the ship pipeline working fluid pipeline; t represents the detection time of the ship pipeline working fluid flow state; and x represents the axial distance along the ship pipeline working fluid pipeline.

[0075] In step S6, the WirelessHART communication module conforms to the wireless communication specification of HART7.6 protocol, which is the core part of the WirelessHART field device, and is compatible with the ultra-wideband wireless transceiver of IEEE802.15.4 protocol. The monitoring system arranges 6 nodes and 1 gateway in an area, and the gateway is responsible for the details of node networking. The arrangement of nodes conforms to the spatial distribution and can facilitate the construction of a robust mesh network. The sensor detection module and the WirelessHART module are combined to realize ultrasonic wave and temperature detection and transmission to the upper computer. Then, the leakage level and leakage amount are obtained by using the ultrasonic wave detection mathematical model. After the node deployment is completed, the gateway communicates with each detection node in the specified area to complete the network initialization and networking work.

[0076] In step S7, if the distributed optical fiber alarms in a certain defense area, the infrared thermal imaging camera matched with this defense area will be popped out to review the temperature of this position. If the alarm signals of the two monitoring systems are reviewed each other, the possibility of leakage at this position will be significantly improved.

[0077] In step S8, the telephone alarm module selects the DTMF two-way receiving / transmitting integrated circuit MT8880, which is specially designed for receiving and transmitting DTMF signals. It can not only generate and receive DTMF signals, but also judge various signal tones (dial tone, ringback tone, busy tone). The chip is set to DTMF mode and interrupt mode, and whether a DTMF signal is received can be judged through the IRQ pin. The DTMF command is input into MT8880 through T1, C1 and R3 for decoding, and the decoded command is input into the P2 port of the single-chip microcomputer U4 for processing. When a certain alarm monitoring signal is valid, the system prompts the machine, and the P2 port outputs the telephone number and control signal, which is converted into a DTMF signal through U3 and output from the 8th pin. The signal is amplified through R17, R16, C4, R12 and Q2, and coupled to the telephone line through T1 to dial the telephone. According to the "alarm mode", two telephones are dialed in turn to alarm. The broadcast voice alarm module selects the finished board XY-V17B, and the voice content is stored in the TF card in advance. The file name is named according to the following table, and the level combination plays in the mode. The P0 port outputs the control signal for corresponding voice broadcast, and the voice is amplified through C6, R10 and Q2, and coupled to the telephone line through T1. According to the length of each voice, the number of voice playing can be controlled and the playing can be stopped at the end of each voice.

[0078] A variety of data acquisition modules are provided. The infrared thermal imager can also be used to measure the temperature of the working medium pipeline of the ship pipeline, and the temperature is used as a basis for judging whether the heat preservation reaches the specified effect. Leakage is prone to occur at the flange sealing position, which can be observed directly by the thermal imager, eliminating the risk of burns during on-site inspection. The infrared thermal imager can be used to monitor the heat preservation of the boiler shell to reduce heat loss, and can also find high temperature points on the outer wall of the boiler. The high temperature points indicate the position of the failure of the refractory layer, thereby avoiding the reduction of process efficiency caused by heat loss.

[0079] An alarm module is provided. When the information acquisition module detects that the working medium of the ship pipeline leaks, the multiple alarm modules in the alarm module can issue a broadcast voice to remind more workers to pay attention to maintenance through the broadcast voice alarm module. At the same time, the telephone alarm module can prompt the relevant personnel in time, so that the alarm efficiency of the whole system is improved, and the overall safety and reliability of the system is increased.

[0080] By integrating the temperature anomaly points of the distributed optical fiber temperature measurement system, the leakage area thermograph of the infrared thermal imager, and the pressure drop data of the first and last end pressure sensors for space-time registration, and combining the improved particle swarm optimization algorithm to solve the flow change model, the comprehensive performance of ship pipeline leakage detection and positioning is significantly improved. The fusion application of multi-source data avoids the limitations of single sensor monitoring, such as the distributed optical fiber temperature measurement system can accurately capture temperature mutation points, the infrared thermal imager can intuitively display temperature difference in the leakage area, and the pressure sensor can reflect flow anomalies through pressure drop changes. The three work together to significantly reduce the risk of false positives caused by environmental interference, ensuring the comprehensiveness and reliability of leakage state monitoring.

[0081] The introduction of the optimization algorithm realizes a breakthrough in positioning accuracy, with the positioning error minimized as the objective function to fuse sensor data, the leakage point position error controlled within ±0.2 meters, and the confidence evaluation results output, providing quantitative decision-making basis for maintenance personnel and solving the problem of traditional positioning ambiguity and large error. The system performs outstandingly in fault tolerance and continuity, the distributed optical fiber temperature measurement system can automatically locate and repair damaged points through the optical fiber fusion machine, and the pressure sensor monitors the pipeline pressure state in real time. Even if a local module fails, it can still maintain stable operation of the overall monitoring process. The intelligent design of the alarm mechanism and data management further enhances the practical value, the combination of telephone alarm and broadcast voice module ensures that maintenance personnel respond quickly, the PC end displays the leakage point coordinates in real time and generates a positioning report, realizing efficient cooperation from leakage detection, accurate positioning to notification processing, effectively shortening the fault handling time, reducing the risk of accident expansion, and overall improving the intelligent and fine level of ship pipeline leakage detection.

[0082] The above are preferred embodiments of the present application, and do not limit the protection scope of the present application, therefore: any equivalent changes made in structure, shape, principle, etc. according to the present application should be covered within the protection scope of the present application.

Claims

1. A method for detecting and locating leaks in ship pipelines based on optimization algorithms, characterized in that: Includes the following steps: S1: First, set up the ship pipeline working fluid leakage data acquisition module. The data acquisition module consists of an infrared thermal imager, a ship pipeline working fluid flow status monitoring module, a distributed fiber optic temperature measurement host, and a distributed temperature measurement fiber optic cable. S2: The temperature control host can be connected to a PC via a communication interface for display; the PC can display the temperature trajectory of the optical cable in real time, highlight alarm signals, and determine and display the actual location of the damaged point of the optical cable; when the optical cable is damaged, the system can locate the damaged point in time and splice it using a fiber optic fusion splicer. S3: Set up an infrared thermal imager to monitor for external leakage of working fluid in ship pipelines. The infrared thermal imager can more intuitively detect whether the insulation layer of the working fluid pipeline is damaged or leaking. If the insulation of the working fluid pipeline falls off, the temperature difference at the point of falloff will be large, which can be clearly shown in the thermal image. S4: Set up a pressure sensor to monitor the flow status of the working medium in the ship's pipeline. Attach the piezoelectric pressure sensor to the working medium in the ship's pipeline to collect the pressure signal on the working medium in the ship's pipeline. S5: Establish a model for calculating the flow rate of the working medium in the ship's pipeline. Based on the changes in the flow rate of the working medium in the ship's pipeline, establish a corresponding model. When the working medium leaks in the ship's pipeline, ignore the influence of the medium flowing inside the pipeline. Let the distance from the leak point to the beginning of the pipe section be x. Then, based on the attenuation of the flow rate of the working medium in the ship's pipeline, the model for the change in the flow rate of the working medium in the ship's pipeline is constructed as follows: In the formula: |△p0| represents the pressure drop of the water flow at the leak point in the pipe section; |△p x | represents the pressure drop at a distance x from the leak point in the pipe section; η represents the flow rate attenuation coefficient of the working medium in the ship's pipeline as it moves further away from the leak point; by installing pressure sensors at the beginning and end of the working medium pipeline in the ship's pipeline, the leak in the working medium pipeline can be successfully monitored when the pressure value of the working medium pipeline in the ship's pipeline is greater than the minimum pressure value that the pressure sensor can detect. S6: The data transmission module transmits the collected information; the data transmission module uses the communication node to transmit relevant information. S7: After receiving the data from the data transmission module, the external leakage monitoring platform software controls and manages the distributed fiber optic temperature measurement and monitoring system, the infrared thermal imaging temperature measurement system, and the ship pipeline working fluid flow status monitoring module. If an abnormal condition occurs in the pipeline, the alarm information from the distributed fiber optic temperature measurement and monitoring system, the infrared thermal imaging temperature measurement system, and the ship pipeline working fluid flow status information will all be displayed on the platform. S8: When a leak of working fluid occurs in the ship's pipeline, the alarm module is activated. At this time, the telephone alarm module starts to broadcast the number to the relevant maintenance personnel to issue an alarm. At the same time, the relevant broadcast voice alarm module is also activated to remind more staff to deal with the leak in a timely manner. After that, the entire online measurement process of the leak of working fluid in the ship's pipeline can be ended. S9: By integrating the temperature anomaly points of the distributed fiber optic temperature measurement system, the thermal image of the leak area from the infrared thermal imager, and the pressure drop data from the pressure sensors at the beginning and end, spatiotemporal registration is performed. An improved particle swarm optimization algorithm is used to solve the flow change model. Multi-source data is fused with minimizing the positioning error as the objective function. Finally, the leak point location and confidence assessment results with an accuracy of ±0.2 meters are output, and the specific coordinates are displayed on the PC and a positioning report is generated. S9.1 Multi-source data spatiotemporal registration: The external leakage monitoring platform software performs spatiotemporal synchronization of the coordinates of temperature anomaly points (accurate to the meter level) collected by the distributed fiber optic temperature measurement system, the thermal image of the leakage area taken by the infrared thermal imager (pixel-level coordinates), and the pressure drop data (△p0, △px) of the first and last pressure sensors, and establishes a multi-source dataset under a unified coordinate system. S9.2 Solution of the localization model based on optimization algorithm: An improved particle swarm optimization (PSO) algorithm is used to optimize the parameters of the flow change model in step S5, with the objective function being to minimize the positioning error. x^fiber: Distance from the leak point directly located by the distributed fiber optic temperature measurement system; x^pressure: Distance to the leak point calculated based on the pressure drop model (Formula: ); x^IR: The projected distance on the pipe from the center of the temperature difference area identified by the infrared thermal imager; α, β, γ: Weighting coefficients (dynamically adjusted according to sensor accuracy, such as 0.5 for fiber optic positioning, 0.3 for pressure model, and 0.2 for infrared); S9.3 Location Result Output and Confidence Assessment: After the algorithm converges, it outputs the final location of the leak point xx (accurate to ±0.2 meters) and calculates the confidence index (such as error probability <5%). The results are displayed on the PC monitoring interface in the form of "pipeline number + distance from the head XX meters + three-dimensional coordinates" and a location report (including comparison curves of data from each sensor) is generated for maintenance personnel to refer to. By fusing multi-source data and iterating optimization algorithms, the problem of ambiguity in single-sensor positioning (such as optical fiber being affected by ambient temperature interference or pressure models ignoring local resistance) can be solved, thereby improving the accuracy of leak point location.

2. The method for detecting and locating leaks in ship pipelines based on optimization algorithms as described in claim 1, characterized in that: In step S1, the distributed fiber optic temperature measurement host is the main body of the fiber optic system. It is responsible for signal acquisition, signal processing, data analysis, over-temperature alarm, and network transmission for the entire ship pipeline working fluid leakage measurement system. The fiber optic temperature measurement host can achieve high positioning accuracy for long-distance working fluid leakage temperature detection along the ship pipeline, without blind spots or dead zones, accurately detecting and locating each temperature point along the line. The distributed temperature measurement fiber mainly performs distributed real-time online monitoring of working fluid leakage measurement in the ship pipeline between the boiler and the wellhead. By linearly laying the temperature-sensing optical cable along the working fluid pipeline, it monitors the temperature distribution around the pipeline in real time. When a local temperature anomaly occurs in the working fluid pipeline, the distributed fiber optic temperature measurement system can promptly capture the anomaly, display it on the temperature curve, issue an alarm, and locate the location information of the anomaly point.

3. The method for detecting and locating leaks in ship pipelines based on optimization algorithms as described in claim 1, characterized in that: In step S1, the distributed temperature measurement fiber principle is based on Brillouin / Raman optical time-domain analysis technology to obtain the temperature information of the fiber and provide spatial resolution indicators; the distributed temperature sensing of the fiber mainly utilizes optical time-domain reflectometry (OTDR) technology and the temperature effect of backscattering / Raman scattering of the fiber; the leak monitoring host uses a special leak detection optical cable to monitor the temperature field gradient along the axial direction of the working medium pipeline of the ship's pipeline in real time; the leak monitoring host scans and records the temperature field gradient values ​​at a high frequency with a dense sampling interval (up to 0.25m), and when the temperature difference or the rate of temperature rise / fall exceeds the set threshold, the system will immediately issue an alarm; according to optical time-domain reflectometry (OTDR) technology, the location of the temperature field change point on the fiber can be accurately determined by using the travel time of the backscattered light.

4. The method for detecting and locating leaks in ship pipelines based on optimization algorithms as described in claim 1, characterized in that: In step S3, the infrared thermal imaging camera will provide 24-hour coverage monitoring of key areas such as the wellhead of the ship's pipeline working fluid, flange valves of the ship's pipeline working fluid, and the outer shell of the ship's pipeline working fluid boiler. Through software analysis algorithms, it will automatically alarm for abnormal temperatures. The infrared thermal imaging temperature measurement technology can provide video preview of the infrared monitoring points and display the temperature of the points in the real-time image. The temperature measurement thermal imaging camera can perform line temperature measurement, frame temperature measurement, and point temperature measurement in real time on the monitoring scene at the front end of the ship's pipeline working fluid. The temperature measurement range is 0~550℃; the temperature measurement accuracy is up to ±2℃ or ±2% of the range (take the maximum value).

5. The method for detecting and locating leaks in ship pipelines based on optimization algorithms as described in claim 1, characterized in that: In step S4, the HL-8 piezoelectric pressure sensor selected in this study can operate normally in the marine pipeline working medium measurement environment, can collect information from the marine pipeline working medium, and can output effectively. In addition, in the noisy environment of marine pipeline working medium operation, the range measurement of this sensor can ensure that it exceeds all values ​​of the marine pipeline working medium pressure and avoid corresponding error problems. Furthermore, this sensor has high accuracy, which can ensure that the signal transmission is within a stable range and accurately collect the changes in the flow state of the marine pipeline working medium. Pressure signals appearing at leak points in the working fluid pipelines of ships; when a leak occurs in the working fluid pipelines of ships, water will overflow, causing leakage or jetting phenomena. However, the initial pressure changes are relatively rapid. These pressure changes will also propagate in both directions in the working fluid pipelines, and can be detected by pressure sensors installed on the working fluid pipelines, thereby obtaining information on the flow rate of the working fluid in the ship's pipelines; the liquid flow process inside the working fluid pipelines of ships is as follows: In the formula: ρ represents the water density inside the working medium pipeline of the ship; v represents the normal flow velocity of the fluid inside the working medium pipeline of the ship; t represents the detection time of the working medium flow state of the ship; x represents the axial distance along the working medium pipeline of the ship.

6. The method for detecting and locating leaks in ship pipelines based on optimization algorithms as described in claim 1, characterized in that: In step S6, the WirelessHART communication module conforms to the HART 7.6 protocol and is the core component of the WirelessHART field device. It is compatible with the IEEE 802.15.4 protocol for ultra-wideband wireless transceivers. This monitoring system deploys 6 nodes and 1 gateway in one area. The gateway is responsible for the details of node networking. The node deployment conforms to spatial distribution and facilitates the construction of a robust mesh network. The sensor detection module and the WirelessHART module are combined to realize ultrasonic and temperature detection and transmit them to the host computer. Then, the leakage level and leakage amount are obtained using the ultrasonic detection mathematical model. After the node deployment is completed, the gateway will communicate with each detection node in the designated area to complete the network initialization and networking work.

7. The method for detecting and locating leaks in ship pipelines based on optimization algorithms as described in claim 1, characterized in that: In step S7, if the distributed optical fiber triggers an alarm in a certain protection zone, it will trigger an infrared thermal imaging camera that matches the protection zone to verify the temperature at that location. If the alarm signals from the two monitoring systems are mutually verified, the possibility of a leak at that location will be significantly increased.

8. The method for detecting and locating leaks in ship pipelines based on optimization algorithms as described in claim 1, characterized in that: In step S8, the telephone alarm module uses the MT8880 bidirectional DTMF transceiver integrated circuit, which is specifically designed for transmitting and receiving dual-tone multi-frequency (DTMF) signals. It can generate and transmit DTMF signals, decode and receive them, and identify various tone signals (dialing tone, ringback tone, busy tone). The chip is set to dual-tone mode and interrupt mode, and the IRQ pin can be used to determine whether a DTMF signal has been received. The DTMF command is decoded by the MT8880 via T1, C1, and R3. After decoding, the command is input to the P2 port of the microcontroller U4 for processing. When a certain alarm monitoring signal is valid, the system activates, and the P2 port outputs the telephone number and control signal. The signal is converted into a DTMF dual-tone multi-frequency signal by U3 and output from pin 8. It is amplified by R17, R16, C4, R12, and Q2, and coupled to the telephone line by T1. When a call is made, two telephones are dialed alternately according to the "alarm mode" to trigger an alarm. The broadcast voice alarm module uses the off-board XY-V17B. The voice content is stored in advance in the TF card, and the file name is named according to the following table. The playback mode is a combination of levels. The P0 port outputs a control signal to broadcast the corresponding voice. The voice is amplified by C6, R10, and Q2, and coupled to the telephone line by T1. The number of times each voice sentence is played can be controlled according to the length of each voice sentence, and playback can stop when each voice sentence ends.

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