Gas pipe system leakage detection device and method for gas engine

Abstract

The invention discloses a gas pipeline system leakage detection device and method for a gas engine, and relates to the technical field of gas pipeline leakage detection, the gas pipeline system leakage detection device comprises a temperature sensor, a data acquisition and processing unit and a display and alarm unit, the temperature sensor is arranged between the inner wall and the outer wall of a double-wall gas pipe, and the data acquisition and processing unit is connected with the display and alarm unit. Temperature sensors are additionally arranged at the bending part, the reducing throttling part and the connecting part of the double-wall gas pipe; the data acquisition and processing unit is used for calculating the position of a leakage point according to data acquired by the temperature sensor; and the display and alarm unit is connected with the data acquisition and processing unit and is used for displaying leakage point information in real time and sending out an alarm signal when leakage is detected. The method can improve the leakage detection efficiency, achieves the precise positioning of a leakage point, and is suitable for the complex environment of a gas pipe system of a marine gas engine.

Description

Technical Field

[0001] The present invention relates to the technical field of gas pipeline leakage detection, and in particular to a gas pipeline leakage detection device and method for a gas engine. Background Art

[0002] During the operation of the double-walled gas pipe of a marine natural gas engine, leakage problems and difficulty in locating the leakage point have a serious impact on its safety and reliability. There are many gas pipeline leakage detection methods in the prior art, but these methods have certain limitations due to the special working conditions and structural characteristics of the double-walled gas pipe used in ships. Some traditional methods based on pressure sensors may be interfered with in complex ship environments, affecting the detection accuracy; and some detection methods based on acoustic or optical principles may not be able to accurately detect and locate the leakage point due to factors such as the double-wall structure and the noise and vibration during the operation of the ship.

[0003] There are some existing solutions for leak detection through the fusion of multiple sensors, but they are all applied in relatively stable environments such as civil natural gas pipelines. The gas pipe system of a marine gas engine is in the cabin environment and faces complex factors such as vibration and noise during the operation of the ship. These complex factors may interfere with the detection principle and signal transmission relied on by the existing fusion solution, affecting the accuracy of detection and positioning. In addition, the space of the marine double-wall gas pipe system is relatively narrow, and there are special requirements for the size and installation method of the sensor. The existing solution does not take this space limitation into account, and its sensor selection and installation method cannot adapt to the environment of the marine gas pipe system, resulting in ineffective installation and normal operation.

[0004] The double-wall structure of the ship's double-wall gas pipe makes it more difficult to detect and locate internal gas leaks, and there are many connection points (such as flanges, welding points, etc.) in the ship's gas pipe system. These points are potential risk points for leakage and need to be monitored; the natural gas used in ship gas engines has specific physical and chemical properties, such as flammability, explosiveness, density and other characteristics; the existing scheme does not comprehensively consider the above factors, resulting in the inability to comprehensively, accurately and efficiently detect leaks, and there may be safety hazards during the detection and positioning process. Summary of the invention

[0005] In view of the deficiencies in the prior art, the purpose of the present invention is to provide a gas pipe system leakage detection device and method for a gas engine, which can improve the leakage detection efficiency, achieve accurate positioning of the leakage point, and is suitable for the complex environment of the gas pipe system of a marine gas engine.

[0006] In order to achieve the above object, the present invention is implemented through the following technical solutions:

[0007] In a first aspect, an embodiment of the present invention provides a gas pipe system leakage detection device for a gas engine, comprising a temperature sensor, a data acquisition and processing unit, and a display and alarm unit, wherein the temperature sensor is arranged between the inner and outer walls of a double-walled gas pipe, and a temperature sensor is additionally arranged at a bend, a diameter-changing throttling part, and a connection of the double-walled gas pipe;

[0008] The data acquisition and processing unit is used to calculate the leakage point location according to the data collected by the temperature sensor;

[0009] The display and alarm unit is connected to the data acquisition and processing unit, and is used to display the leakage point information in real time and send out an alarm signal when a leakage is detected.

[0010] As a further implementation method, the temperature sensor is inserted between the inner and outer walls of the double-walled gas pipe through the hole, and sealant is filled between the temperature sensor and the hole wall.

[0011] As a further implementation, the hole adopts a sealed thread structure, and the temperature sensor is fixed in the hole by a nut.

[0012] As a further implementation, the connection line of the temperature sensor is led out of the double-wall gas pipe through a sealed metal hose, and a sealing structure is provided at the connection between the metal hose and the pipe wall.

[0013] As a further implementation, the connecting wire and the metal hose are wrapped with insulating material on the outside.

[0014] In a second aspect, an embodiment of the present invention further provides a method for detecting leakage of a gas pipe system for a gas engine, using the detection device, comprising:

[0015] The temperature sensor acquires temperature data in real time and transmits the temperature data to the data acquisition and processing unit;

[0016] The data acquisition and processing unit processes the temperature data based on the leak detection algorithm to determine whether there is a leak;

[0017] When there is a leak, the leak point is located according to the leak point location algorithm to determine the coordinates of the leak point.

[0018] As a further implementation, the leakage detection algorithm is:

[0019] The measured temperature of the i-th temperature sensor at time t is T i (t), in the absence of leakage, by statistically analyzing the temperature data within the set time, the average value of the temperature stability range is determined to be The standard deviation is σ, and the temperature deviation of each temperature sensor is calculated The temperature deviation is used as the basis for determining the leakage point.

[0020] As a further implementation, when ΔT i When (t)>kσ, there is leakage in the area where the corresponding temperature sensor is located; k is the set threshold coefficient.

[0021] As a further implementation, the leakage point location algorithm is:

[0022] The two-dimensional coordinates of the leakage point are (x, y). The temperature sensor array has m temperature sensors in the x direction and n temperature sensors in the y direction. Their coordinates are (x i ,y j ),i=1,2,…,m,j=1,2,…,n;

[0023] According to the heat conduction theory, the temperature change around the leak point is inversely proportional to the distance from the leak point. A positioning equation is established and the coordinates (x, y) of the leak point are solved by fitting the positioning equation using the least squares method.

[0024] As a further implementation, the positioning equation is:

[0025] Where ΔT ij (t) is the temperature sensor (x i ,y j ) Temperature deviation at time t, is the distance from the temperature sensor to the leakage point, and A and B are coefficients determined based on multiple sets of experimental results.

[0026] The beneficial effects of the present invention are as follows:

[0027] (1) The temperature sensors of the present invention are evenly distributed between the inner and outer walls of the double-walled pipe, and temperature sensors are added to special parts - bending parts and throttling parts, so as to comprehensively monitor the temperature changes of the pipe system; the data acquisition and processing unit processes the temperature sensor data according to the leakage detection algorithm to determine whether there is a leakage; when a leakage is detected, the temperature sensor data is used to locate the leakage point according to the leakage point location algorithm to determine the coordinates of the leakage point, thereby improving the accuracy, stability and efficiency of leakage detection.

[0028] (2) The present invention determines the mean value and standard deviation of the temperature stability range by statistically analyzing the temperature data within a period of time, and calculates the temperature deviation to judge the leakage; this method based on statistical analysis can more accurately identify temperature anomalies and improve the accuracy of leak detection, which is more accurate than some existing algorithms with simple threshold judgment; using the temperature sensor array data, a positioning equation is established according to the heat conduction theory, and the coordinates of the leak point are solved by the least squares fitting equation. This positioning method based on physical principles and precise calculation can more accurately determine the location of the leak point; when determining the various parameters in the algorithm, through experiments, multiple factors such as the properties of natural gas, the material and structure of the pipeline, and the operating environment of the ship are considered; this method of determining parameters by comprehensively considering multiple practical factors enables the algorithm to better adapt to the complex environment of the gas pipeline system of the marine gas engine, thereby improving the stability of the algorithm. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0030] Figure 1 and Figure 2 is a schematic diagram of a temperature sensor arrangement according to one or more embodiments of the present invention;

[0031] Figure 3 is a flow chart of a detection method according to one or more embodiments of the present invention.

[0032] Among them, 1. double-wall gas pipe, 2. temperature sensor, 3. metal hose. DETAILED DESCRIPTION

[0033] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0034] Embodiment 1:

[0035] The present embodiment provides a gas pipe system leakage detection device for a gas engine, including a temperature sensor 2, a data acquisition and processing unit, and a display and alarm unit. The temperature sensor 2 module is used to collect temperature data; the data acquisition and processing unit is used to analyze and process the data collected by the temperature sensor 2 to detect whether there is a leak and locate the leak point; the display and alarm unit is used to display the detection results and issue an alarm.

[0036] This embodiment selects a micro temperature sensor 2 based on the principle of a thermocouple or thermistor. Considering the isolated and closed environment between the inner and outer walls of the double-walled tube, a magnetic sensor is preferably used. This sensor has a small permanent magnet embedded in the bottom of its outer shell. Its size is as small as millimeters and can adapt to narrow installation environments. Its probe part has good thermal conductivity and response speed to accurately sense temperature changes.

[0037] During the design and manufacturing of the gas pipe system, the arrangement position of the temperature sensor 2 is planned in advance, and a suitable installation channel is reserved. The channel adopts a sealed thread structure, and its size matches the external dimensions of the temperature sensor 2. During installation, the temperature sensor 2 is inserted into the space between the inner and outer walls through the channel, and the sealant is filled between the temperature sensor 2 and the channel wall, and then the temperature sensor 2 is fixed in the channel with a nut to ensure a good seal.

[0038] In this embodiment, if Figure 1 and Figure 2 As shown, the temperature sensors 2 are evenly distributed between the inner and outer walls of the double-walled gas pipe 1 to ensure that the temperature changes of the pipe system can be fully monitored. At the bends and reducers of the pipeline, the temperature distribution is uneven due to changes in the gas flow state, so the density of the temperature sensors 2 needs to be increased to more accurately detect whether there is a leak. In addition, in areas close to the connection, such as flange connections, welding areas, etc., there is a risk of poor sealing due to the connection process, so these areas also need to be monitored, and the temperature sensors 2 are reasonably arranged on both sides and around the connection areas.

[0039] Since there are multiple sensors on the periphery of the engine, in order to avoid electromagnetic interference between each other, the wiring harness of the temperature sensor 2 uses a wiring harness material with a shielding function, and is connected at one end of the double-walled tube and connected with an aviation plug. Specifically, the connecting wire of the temperature sensor 2 is led out through a sealed metal hose 3. During the installation process, the metal hose 3 is closely connected to the pipe wall and the installation part of the temperature sensor 2 to prevent gas leakage; sealant or a sealing rubber ring is used at the connection for sealing. Wear-resistant and corrosion-resistant insulating materials such as polyvinyl chloride or rubber sheaths are wrapped around the outside of the metal hose 3 and the connecting wire. For longer wiring lines, a segmented fixing method is adopted, and cable ties or clamps are used to fix the line to the hull structure or pipe bracket to reduce the shaking and stress of the line.

[0040] The display and alarm unit is used to receive the detection results and leakage point location information transmitted by the data acquisition and processing unit; the other has a display screen, which can intuitively display the real-time data of the temperature sensor 2, whether there is a leakage, the coordinate position of the leakage point and other information. When a leakage is detected, the alarm unit will issue an audible and visual alarm to remind the operator to take maintenance measures in time.

[0041] The detection principle of this embodiment is:

[0042] like Figure 3 As shown, the temperature sensor 2 collects temperature data in real time and transmits the temperature data to the data acquisition and processing unit; the data acquisition and processing unit processes the temperature sensor 2 data according to the leakage detection algorithm to determine whether there is a leak. If a leak is detected, the leak point is located using the temperature sensor 2 data according to the leak point location algorithm to determine the coordinates of the leak point.

[0043] The data acquisition and processing unit transmits the leak detection and positioning results to the display and alarm unit, which displays the relevant information on the display screen in a timely manner and issues an audible and visual alarm when a leak is detected, so that the operator can take appropriate maintenance measures.

[0044] Maintain the device regularly and check the working status of the temperature sensor 2 to ensure its normal operation. Check whether the temperature sensor 2 is damaged or the connection line is loose. If there is any problem, replace or repair it in time. And calibrate the device regularly, and re-determine the parameters in the leak detection algorithm and positioning algorithm according to the actual situation. For example, as the pipeline is used for a longer time, its material properties may change, or the operating environment of the ship may change, which may affect the measurement accuracy of the temperature sensor 2 and the accuracy of the algorithm. Therefore, regular calibration is required to ensure the reliability and accuracy of the device.

[0045] The detection device of this embodiment can effectively improve the accuracy of gas pipe leakage detection for marine gas engines and the accuracy of leakage point positioning, thereby providing a guarantee for the safe operation of the marine double-wall gas pipe 1.

[0046] Embodiment 2:

[0047] This embodiment provides a method for detecting leakage of a gas pipe system for a gas engine, using the detection device described in Embodiment 1, such as Figure 3 As shown, the temperature sensor acquires temperature data in real time and transmits the temperature data to the data acquisition and processing unit; the data acquisition and processing unit processes the temperature data based on the leakage detection algorithm to determine whether there is a leakage; when there is a leakage, the leakage point is located according to the leakage point location algorithm to determine the coordinates of the leakage point.

[0048] Specifically, the leak detection algorithm is:

[0049] The measured temperature of the i-th temperature sensor at time t is T i (t), in the absence of leakage, by statistically analyzing the temperature data within a certain period of time, the average value of the temperature stability range is determined to be The standard deviation is σ, and the temperature deviation of each temperature sensor is calculated When ΔTi When (t)>kσ, it is considered that there is leakage in the area where the temperature sensor is located; k is the set threshold coefficient, which is determined according to the actual situation.

[0050] The leak point location algorithm is:

[0051] When a possible leak is detected based on the temperature field change, the data of the temperature sensor array is used to locate the leak point. The two-dimensional coordinates of the leak point are defined as (x, y). The temperature sensor array has m temperature sensors in the x direction and n temperature sensors in the y direction. The corresponding two-dimensional coordinates are (x i ,y j ),i=1,2,…,m,j=1,2,…,n.

[0052] According to the heat conduction theory, the temperature change around the leak point is inversely proportional to the distance from the leak point, and the positioning equation is established:

[0053]

[0054] Where ΔT ij (t) is the temperature sensor (x i ,y j ) Temperature deviation at time t, is the distance from the temperature sensor to the leakage point, and A and B are coefficients determined according to multiple sets of leakage test results.

[0055] The coordinates (x, y) of the leakage point are solved by fitting the positioning equation using the least squares method.

[0056] This embodiment determines various parameters in the leakage detection algorithm and the positioning algorithm through experiments and theoretical analysis; for example, in the detection method based on temperature field changes, the average value of the stable range is determined. Standard deviation σ and threshold coefficient k; Determine coefficients A, B, etc. in the positioning method based on temperature sensor data; The determination of these parameters needs to consider multiple factors such as the properties of natural gas, the material and structure of the pipeline, and the operating environment of the ship.

[0057] In terms of efficiency, the present embodiment has the following aspects: the temperature sensor collects data in real time, the temperature sensor is sensitive to reaction, and can quickly process data according to the corresponding algorithm; this real-time performance can detect leakage more quickly.

[0058] In terms of accuracy: by statistically analyzing the temperature data over a period of time to determine the average and standard deviation of the temperature stability range, the temperature deviation is calculated to determine the leak; this method based on statistical analysis can more accurately identify temperature anomalies and improve the accuracy of leak detection, which is more accurate than some existing algorithms with simple threshold judgments. Using the temperature sensor array data, the positioning equation is established according to the heat conduction theory, and the coordinates of the leak point are solved by fitting the equation using the least squares method. This positioning method based on physical principles and precise calculations can more accurately determine the location of the leak point.

[0059] In terms of stability: when determining the various parameters in the algorithm, through experiments, various factors such as the properties of natural gas, the material and structure of the pipeline, and the operating environment of the ship were taken into consideration; this method of determining parameters by comprehensively considering multiple practical factors enables the algorithm to better adapt to the complex environment of the gas piping system of marine gas engines and improves the stability of the algorithm.

[0060] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A gas pipeline leakage detection device for a gas engine, characterized in that: It includes a temperature sensor, a data acquisition and processing unit, and a display and alarm unit. The temperature sensor is arranged between the inner and outer walls of the double-walled gas pipe, and additional temperature sensors are provided at the bends, diameter-changing throttling parts, and connections of the double-walled gas pipe; The data acquisition and processing unit is used to calculate the leakage point location according to the data collected by the temperature sensor; The display and alarm unit is connected to the data acquisition and processing unit, and is used to display the leakage point information in real time and send out an alarm signal when a leakage is detected.

2. A gas pipe system leakage detection device for a gas engine according to claim 1, characterized in that: The temperature sensor is inserted between the inner and outer walls of the double-wall gas pipe through the hole, and sealant is filled between the temperature sensor and the hole wall.

3. A gas pipe system leakage detection device for a gas engine according to claim 2, characterized in that: The hole adopts a sealed thread structure, and the temperature sensor is fixed in the hole by a nut.

4. A gas pipe system leakage detection device for a gas engine according to any one of claims 1 to 3, characterized in that: The connecting wire of the temperature sensor is led out of the double-wall gas pipe through a sealed metal hose, and a sealing structure is provided at the connection between the metal hose and the pipe wall.

5. A gas pipe system leakage detection device for a gas engine according to claim 4, characterized in that: The connecting wire and the metal hose are wrapped with insulating materials on the outside.

6. A method for detecting leakage of a gas pipe system for a gas engine, characterized in that: A detection device as claimed in any one of claims 1 to 5, comprising: The temperature sensor acquires temperature data in real time and transmits the temperature data to the data acquisition and processing unit; The data acquisition and processing unit processes the temperature data based on the leak detection algorithm to determine whether there is a leak; When there is a leak, the leak point is located according to the leak point location algorithm to determine the coordinates of the leak point.

7. A gas pipeline leakage detection method for a gas engine according to claim 6, characterized in that: The leak detection algorithm is: The measured temperature of the i-th temperature sensor at time t is T i (t), in the absence of leakage, by statistically analyzing the temperature data within the set time, the average value of the temperature stability range is determined to be The standard deviation is σ, and the temperature deviation of each temperature sensor is calculated The temperature deviation is used as the basis for determining the leakage point.

8. A gas pipeline leakage detection method for a gas engine according to claim 7, characterized in that: When |ΔT i When (t)|>kσ, there is leakage in the area where the corresponding temperature sensor is located; k is the set threshold coefficient.

9. A gas pipeline leakage detection method for a gas engine according to claim 6, characterized in that: The leakage point location algorithm is: The coordinates of the leakage point in two dimensions are (x, y). The temperature sensor array has m temperature sensors in the x direction and n temperature sensors in the y direction. Their coordinates are (x i ,y j ),i=1,2,…,m,j=1,2,…,n; According to the heat conduction theory, the temperature change around the leak point is inversely proportional to the distance from the leak point. A positioning equation is established and the coordinates (x, y) of the leak point are solved by fitting the positioning equation using the least squares method.

10. A gas pipeline leakage detection method for a gas engine according to claim 9, characterized in that: The positioning equation is: Where ΔT ij (t) is the temperature sensor (x i ,y j ) Temperature deviation at time t, is the distance from the temperature sensor to the leakage point, and A and B are coefficients determined based on multiple sets of experimental results.

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