Carbon dioxide pipeline leakage monitoring system and detection method

Abstract

The invention discloses a carbon dioxide pipeline leakage monitoring system and detection method, and relates to the technical field of pipeline leakage monitoring, the carbon dioxide pipeline leakage monitoring system comprises a pipe body, a thermal insulation layer, a support frame, a plurality of temperature measurement optical fibers, a laser source, a detection host and a monitoring device, the thermal insulation layer sleeves the pipe body, and an annular cavity is limited between the thermal insulation layer and the pipe body; the multiple supporting frames are arranged in the annular cavity at intervals, the multiple temperature measuring optical fibers are arranged in the annular cavity along the pipe body, the laser source is connected with the temperature measuring optical fibers and used for emitting laser pulse signals, and the detection host is connected with the temperature measuring optical fibers and used for obtaining temperature signals of all detection points. And the monitoring device is connected with the detection host and is used for comprehensively judging whether the pipeline leaks or not and judging leakage points of the pipeline according to the temperature signals of the detection points. According to the carbon dioxide pipeline leakage monitoring system, the position of a leakage point can be accurately positioned, the environmental influence is small, the detection efficiency is high, and the layout cost is low.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of pipeline leakage monitoring, in particular to a carbon dioxide pipeline leakage monitoring system and a detection method. BACKGROUND

[0002] In carbon storage and utilization technology, critical carbon dioxide is often transported and geologically stored through pipelines. However, with the increase of use time, pipeline aging, changes in geographical and climate environment, and human damage, leakage accidents often occur. Establishing a pipeline monitoring system to realize real-time monitoring of pipeline leakage, minimizing economic losses and resource waste, and avoiding environmental pollution and safety accidents as much as possible are indispensable measures.

[0003] In related technologies, the preferred monitoring method is optical fiber sensing monitoring. Optical fiber sensing technology has many advantages such as high measurement sensitivity, anti-electromagnetic interference, anti-radiation, high pressure resistance, corrosion resistance, small size, and light weight. However, there are the following problems in the process of detecting the pipeline: the system cannot identify the temperature change along the pipeline, the monitoring distance is short, and the leakage point positioning accuracy is poor; or the cost of laying is high, and there is a missed detection phenomenon; or when monitoring the pipeline leakage, factors such as the size of the pressure in the pipeline, the size of the leakage, the location of the leakage point, and the length of the optical fiber ring will affect the accuracy of the measurement, resulting in a large measurement error. SUMMARY

[0004] The present application aims to at least partially solve one of the technical problems in the related art.

[0005] To this end, the present application provides a carbon dioxide pipeline leakage monitoring system, which can accurately locate the position of the leakage point, is less affected by the environment, has high detection efficiency, and has low laying cost.

[0006] The present application also provides a carbon dioxide pipeline leakage detection method.

[0007] The carbon dioxide pipeline leakage monitoring system of the present application comprises: a pipe body; a heat preservation layer and a support frame, the heat preservation layer is sleeved on the pipe body, and an annular cavity is defined between the heat preservation layer and the pipe body, the support frame is annular and provided in plurality, and the plurality of support frames are provided in the annular cavity in an axial direction of the pipe body; a plurality of temperature measurement optical fibers, the plurality of temperature measurement optical fibers are provided in the annular cavity in the axial direction of the pipe body, and the temperature measurement optical fibers are provided in the support frame and have a set distance between the temperature measurement optical fibers and the side wall of the pipe body; A laser source connected with the temperature measuring fiber and used for emitting laser pulse signals, and a detection host connected with the temperature measuring fiber and used for acquiring temperature signals of each detection point along the pipeline; A monitoring device connected with the detection host, used for displaying the temperature of each detection point in real time and comprehensively judging whether the pipeline leaks and the leakage point of the pipeline according to the temperature signals of each detection point.

[0008] The carbon dioxide pipeline leakage monitoring system can accurately locate the position of the leakage point, has less environmental influence, high detection efficiency and low laying cost.

[0009] In some embodiments, the support frame is a ring plate structure, and a first hole for the temperature measuring fiber to pass through is arranged on the support frame in the circumferential direction, and a sealed cavity is limited between the support frame and the pipe body and the heat preservation layer.

[0010] In some embodiments, the support frame includes a plurality of fan-shaped unit plates, and two adjacent unit plates are connected by bolts, or are clamped and matched.

[0011] In some embodiments, among the plurality of temperature measuring fibers, part of the temperature measuring fibers are spirally wound in the first spiral direction in the annular cavity, and part of the temperature measuring fibers are spirally wound in the second spiral direction in the annular cavity, the first spiral direction and the second spiral direction are opposite, and the plurality of optical fibers intersecting with each other limit a monitoring network in the annular cavity.

[0012] In some embodiments, a second hole for gas to pass through is arranged on the support frame, and a plurality of support rings are arranged at intervals between two adjacent support frames, and the ring width of the support ring is not less than 50 mm.

[0013] In some embodiments, the material of the heat preservation layer is one or more of rock wool, polyethylene, silicate composite heat preservation material, glass wool, rigid polyurethane foam plastic, and rubber sponge, and / or the thickness of the heat preservation layer is 100-200 mm.

[0014] In some embodiments, the distance between the temperature measuring fiber and the side wall of the pipeline is not less than 50 mm.

[0015] The carbon dioxide pipeline leakage detection method includes the carbon dioxide pipeline leakage monitoring system of any one of the above embodiments, and the detection method includes the following steps: The support frame is installed on the pipeline in the axial direction at intervals; The temperature measuring fiber extending along the axial direction of the pipeline is laid on the circumferential side of the pipeline through the support frame; The heat preservation layer is sleeved on the support frame, and the support frame and the temperature measuring optical fiber are insulated and protected by the heat preservation layer; The temperature measuring optical fiber emits a pulse signal through a laser source, and the laser pulse signal generates a backscattering Raman reflection light sensing signal in the temperature measuring optical fiber; The detection host obtains temperature signals of the temperature measuring optical fiber at each detection point along the pipeline by receiving the reflection light sensing signal; The monitoring device determines abnormal temperature signals of each detection point, and analyzes to determine whether the pipeline leaks and the position of the pipeline leak.

[0016] In some embodiments, when laying the temperature measuring optical fiber, the temperature measuring optical fiber has a set distance from the pipeline and the heat preservation layer, respectively.

[0017] In some embodiments, when determining the temperature abnormal point, the following steps are included: According to the temperature signals of each detection point, the temperature signals of each detection point are compared with the preset temperature signals of each detection point stored in the detection host. If there is a difference, it is an abnormal temperature signal; otherwise, it is a normal temperature signal. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 is a schematic diagram of the arrangement of the temperature measuring optical fiber in the carbon dioxide pipeline leak monitoring system of the embodiments of the present application.

[0019] Reference signs: Pipe body 1; heat preservation layer 2; support frame 3; temperature measuring optical fiber 4. DETAILED DESCRIPTION

[0020] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below by referring to the accompanying drawings are exemplary and are intended to explain the present application, and cannot be understood as a limitation of the present application.

[0021] As Figure 1As shown, the carbon dioxide pipeline leakage monitoring system of the embodiment of the present application comprises a pipe body 1, a heat preservation layer 2, a plurality of support frames 3, a plurality of temperature measurement optical fibers 4, a laser source, a detection host and a monitoring device, the heat preservation layer 2 is sleeved on the pipe body 1, and a ring-shaped cavity is limited between the heat preservation layer 2 and the pipe body 1, the support frames 3 are annular and a plurality of support frames 3 are provided, the plurality of support frames 3 are provided in the ring-shaped cavity along the axial direction of the pipe body 1, the plurality of temperature measurement optical fibers 4 are provided in the ring-shaped cavity along the axial direction of the pipe body 1, and the temperature measurement optical fibers 4 are provided through the support frames 3 and a set distance is provided between the temperature measurement optical fibers 4 and the side wall of the pipe body 1, the laser source is connected with the temperature measurement optical fibers 4 and is used for emitting a laser pulse signal, the detection host is connected with the temperature measurement optical fibers 4 and is used for acquiring temperature signals of each detection point along the pipeline, the monitoring device is connected with the detection host, and the monitoring device is used for displaying the temperature of each detection point in real time and is used for comprehensively judging whether the pipeline leaks and judging the leakage point of the pipeline according to the temperature signals of each detection point.

[0022] In use, the laser source emits a pulse signal to the temperature measurement optical fiber 4, the laser pulse signal generates a back Raman scattering form of reflected light sensing signal in the temperature measurement optical fiber 4, the detection host acquires the temperature signals of each detection point along the pipeline by receiving the reflected light sensing signal, the monitoring device analyzes and determines an abnormal temperature signal according to the temperature signals of each detection point, that is, when the temperature of a certain detection point is different from the temperatures of the adjacent detection points before and after the certain detection point and is different from the recorded temperature stored in the detection host, the temperature signal of the certain detection point is an abnormal temperature signal, the certain detection point has pipeline leakage, and the pipeline leakage position is determined according to the pipeline position corresponding to the certain detection point.

[0023] The carbon dioxide pipeline leakage monitoring system of the embodiment of the present application can accurately position the position of the leakage point, has less influence on the environment, has high detection efficiency, and has low layout cost.

[0024] It should be noted that the present embodiment adopts the principle of distributed temperature sensing (DTS): the principle of fiber temperature measurement is based on the back Raman scattering effect. Laser pulses enter from one end of the optical fiber, and the optical fiber molecules interact during forward propagation, resulting in multiple types of scattering. Among them, Raman scattering is due to the thermal vibration of optical fiber molecules to produce a light longer than the wavelength of the light source, called Stokes light, and a light shorter than the wavelength of the light source, called Anti-Stokes light. The intensity of the Anti-Stokes light signal is more sensitive to temperature. The proportion of the Anti-Stokes light signal and the Stokes light signal intensity from any point in the optical waveguide can obtain the temperature information of the point. The above technical principle is used to realize the distributed measurement of the temperature field along the optical fiber by using the optical time domain reflectometry (OTDR) principle, that is, the transmission speed of light in the optical fiber and the time of back light echo are used to locate the hot spots.

[0025] In some embodiments, the support frame 3 is a ring plate structure, and the support frame 3 is provided with a first hole for the temperature measuring optical fiber 4 to pass through in the circumferential direction. The adjacent two support frames 3 and the pipe body 1 and the heat preservation layer 2 limit a sealed cavity.

[0026] By setting the support frame 3 as a ring plate structure, the annular cavity is divided into multiple measurement units along the extension direction of the pipeline while supporting the protective layer, so that each measurement unit has a detection point, which facilitates the detection of pipeline leakage and avoids the radial flow of carbon dioxide along the pipeline after entering the annular cavity. Facilitate the isolation of the position of the pipeline leakage, and then facilitate the positioning of the leakage point, improve the reliability and detection efficiency of the pipeline leakage monitoring.

[0027] In some embodiments, the support frame 3 includes a plurality of fan-shaped unit plates, and adjacent two unit plates are connected by bolts, or the adjacent two unit plates are clamped and matched.

[0028] The support frame 3 is obtained by splicing a plurality of unit plates, which facilitates the installation of the support frame 3 on the pipeline and ensures the reliability of the support frame 3 during use.

[0029] Optionally, the two ends of the unit plate are respectively provided with connecting flanges, and the two connecting flanges are fixed by bolts to realize the connection of the unit plate. The support frame 3 is spliced by two unit plates, which not only ensures the split structure of the support frame 3, but also facilitates the quick splicing and installation of the support frame 3.

[0030] In some embodiments, among the plurality of temperature measuring optical fibers 4, part of the temperature measuring optical fibers 4 are spirally wound in the annular cavity along a first spiral direction, and part of the temperature measuring optical fibers 4 are spirally wound in the annular cavity along a second spiral direction, the first spiral direction and the second spiral direction are opposite, and the plurality of optical fibers intersecting with each other limit the monitoring network in the annular cavity.

[0031] By spirally arranging the temperature measuring optical fibers 4, the detection efficiency of the pipeline leakage can be further improved by the monitoring network formed by the plurality of temperature measuring optical fibers 4, and the leakage point can be further positioned and the position of the leakage point can be further verified by the plurality of temperature measuring optical fibers 4, so as to avoid monitoring failure.

[0032] In some embodiments, the support frame 3 is provided with a second hole for the gas to pass through, and a plurality of support rings are arranged at intervals between adjacent two support frames 3, and the ring width of the support ring is not less than 50 mm.

[0033] By arranging the second hole on the support frame 3, the temperature flow in the annular cavity is facilitated, so that the air temperature in the annular cavity is maintained within a set range under normal circumstances, and by arranging the support pipe, the temperature measuring optical fibers 4 spirally arranged are prevented from contacting the pipeline side wall, and the minimum distance between the temperature measuring optical fibers 4 and the pipeline is ensured, so as to avoid the temperature of the pipeline side wall interfering with the measurement of the temperature measuring optical fibers 4 or increasing the measurement error of the temperature measuring optical fibers 4.

[0034] In some embodiments, the material of the heat preservation layer 2 is one or more of rock wool, polyethylene, silicate composite heat preservation material, glass wool, rigid polyurethane foam plastic, and rubber sponge, which is convenient for material procurement and reduces the raw material cost of the heat preservation layer 2.

[0035] In some embodiments, the thickness of the heat preservation layer 2 is 100-200 mm, and by limiting the thickness of the heat preservation layer 2, the heat insulation and sealing effects of the heat preservation layer 2 are ensured.

[0036] In some embodiments, the distance between the temperature measuring optical fibers 4 and the pipeline side wall is not less than 50 mm, and by limiting the distance between the temperature measuring optical fibers 4 and the pipeline side wall, the temperature of the pipeline side wall is prevented from being directly conducted to the temperature measuring optical fibers 4, so as to interfere with the measurement of the temperature measuring optical fibers 4 or increase the measurement error of the temperature measuring optical fibers 4.

[0037] The carbon dioxide pipeline leakage detection method of the embodiments of the present application is described below.

[0038] The carbon dioxide pipeline leakage detection method of the embodiments of the present application comprises the carbon dioxide pipeline leakage monitoring system of any one of the above embodiments, and the detection method comprises the following steps: The support frames 3 are installed on the pipeline at intervals along the axial direction; The temperature measuring optical fibers 4 extending along the axial direction of the pipeline are laid on the circumferential side of the pipeline through the support frames 3; The thermal insulation layer 2 is sleeved on the support frame 3, and the support frame 3 and the temperature measuring optical fiber 4 are insulated and protected by the thermal insulation layer 2. The laser source emits a pulse signal to the temperature measuring optical fiber 4, and the laser pulse signal generates a backscattering reflection light sensing signal in the form of backscattering Raman scattering in the temperature measuring optical fiber 4. The detection host obtains temperature signals of the temperature measuring optical fiber 4 at each detection point along the pipeline by receiving the reflection light sensing signal. The monitoring device determines abnormal temperature signals of each detection point and analyzes to determine whether the pipeline leaks and the position of the pipeline leak.

[0039] The carbon dioxide pipeline leak detection method can accurately locate the position of the leak point, has less environmental influence, high detection efficiency, and low laying cost.

[0040] In some embodiments, when laying the temperature measuring optical fiber 4, the temperature measuring optical fiber 4 has a set distance from the pipeline and the thermal insulation layer 2, respectively, the distance between the temperature measuring optical fiber 4 and the pipeline side wall is limited, and the temperature of the pipeline side wall is directly conducted to the temperature measuring optical fiber 4 to avoid interference with the measurement of the temperature measuring optical fiber 4 or increase the measurement error of the temperature measuring optical fiber 4.

[0041] In some embodiments, when determining the temperature abnormal point, the following steps are included: According to the temperature signals of each detection point, the temperature signals of each detection point are compared with the preset temperature signals of each detection point stored in the detection host, if there is a difference, it is an abnormal temperature signal, otherwise it is a normal temperature signal.

[0042] By comparing the temperature signals of the detection points with the preset temperature signals of the detection points stored in the detection host, the temperature jump of the pipeline side caused by the leakage can be located, and the temperature signals of the detection points and the temperature signals of the adjacent detection points can be compared again to verify the abnormal temperature signals, so as to ensure the accuracy of the detection of the leak point.

[0043] In the description of the present application, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0044] In addition, the terms "first", "second", etc. are used only for the purpose of description and do not imply or imply relative importance or imply the number of the technical features indicated. Therefore, the features defined as "first", "second" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "a plurality of" is at least two, such as two, three, etc., unless otherwise explicitly defined.

[0045] In the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connecting", "fixing" and the like should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected or communicated with each other; it can be directly connected, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements or the interaction relationship between two elements, unless otherwise explicitly limited. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0046] In the present application, unless otherwise explicitly specified and limited, the first feature is "on" or "under" the second feature, which can be direct contact between the first and second features, or indirect contact between the first and second features through an intermediate medium. Moreover, the first feature "above", "above" and "above" the second feature can be directly above or obliquely above the first feature, or only indicate that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "below" and "below" the second feature can be directly below or obliquely below the first feature, or only indicate that the horizontal height of the first feature is less than that of the second feature.

[0047] In the description of the present application, the description of the terms "one embodiment", "some embodiments", "example", "specific example" or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In the present application, the illustrative description of the above terms is not necessarily for the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any suitable manner in any one or more embodiments or examples. In addition, those skilled in the art can combine and combine different embodiments or features of different embodiments or examples described in the present application without contradiction.

[0048] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limiting the present application, and those skilled in the art can make changes, modifications, replacements and variations to the above embodiments within the scope of the present application.

Claims

1. A carbon dioxide pipeline leak monitoring system, characterized by, The application relates to a carbon dioxide pipeline leakage monitoring system, which comprises the following parts: a pipe body, a heat preservation layer and support frames, the heat preservation layer is sleeved on the pipe body, and an annular cavity is formed between the heat preservation layer and the pipe body; the support frames are annular and are arranged in the annular cavity in an axial direction; a plurality of temperature measuring optical fibers are arranged in the annular cavity in the axial direction of the pipe body, the temperature measuring optical fibers pass through the support frames and are arranged at a certain distance from the side wall of the pipe body; a laser source is connected with the temperature measuring optical fibers and is used for emitting laser pulse signals; a detection host is connected with the temperature measuring optical fibers and is used for acquiring temperature signals of each detection point along the pipeline; a monitoring device is connected with the detection host, the monitoring device is used for displaying the temperature of each detection point in real time and judging whether the pipeline leaks and the leakage position of the pipeline according to the temperature signals of each detection point. The support frame is a ring plate structure, a first hole for the temperature measuring optical fibers to pass through is arranged on the support frame in a circumferential direction, and a sealed cavity is formed between the support frames, the pipe body and the heat preservation layer. The support frame comprises a plurality of fan-shaped unit plates, and two adjacent unit plates are connected through bolts or are connected through clamping. In the plurality of temperature measuring optical fibers, part of the temperature measuring optical fibers are spirally wound in a first spiral direction in the annular cavity, and part of the temperature measuring optical fibers are spirally wound in a second spiral direction in the annular cavity; the first spiral direction and the second spiral direction are opposite to each other, and the plurality of optical fibers intersect with each other to form a monitoring net in the annular cavity. A second hole for gas to pass through is arranged on the support frame, a plurality of support rings are arranged between two adjacent support frames, and the ring width of the support ring is not less than 50 mm. The material of the heat preservation layer is one or more of rock wool, polyethylene, silicate composite heat preservation material, glass wool, rigid polyurethane foam plastic and rubber sponge, and / or the thickness of the heat preservation layer is 100-200 mm.

2. The carbon dioxide pipeline leak monitoring system of claim 1, wherein, The distance between the temperature measuring optical fibers and the side wall of the pipeline is not less than 50 mm.

3. The carbon dioxide pipeline leak monitoring system of claim 2, wherein, The application further discloses a detection method of the carbon dioxide pipeline leakage monitoring system.

4. The carbon dioxide pipeline leak monitoring system of claim 1, wherein, The support frames are arranged on the pipeline in an axial direction; 5. The carbon dioxide pipeline leak monitoring system of claim 4, wherein, The temperature measuring optical fibers are arranged on the pipeline through the support frames; 6. The carbon dioxide pipeline leak monitoring system of any one of claims 1-5, wherein, The heat preservation layer is sleeved on the support frames to protect the support frames and the temperature measuring optical fibers; 7. The carbon dioxide pipeline leak monitoring system of any one of claims 1-5, wherein, The laser source emits pulse signals to the temperature measuring optical fibers, and the laser pulse signals generate reflection light sensing signals in the form of backward Raman scattering in the temperature measuring optical fibers; 8. A method of detecting a leak in a carbon dioxide pipeline, the method comprising: The detection host acquires temperature signals of each detection point along the pipeline through the reflection light sensing signals; The monitoring device determines abnormal temperature signals of each detection point and analyzes the abnormal temperature signals to determine whether the pipeline leaks and the leakage position of the pipeline. The temperature measuring optical fibers have a certain distance from the pipeline and the heat preservation layer when the temperature measuring optical fibers are arranged. When the abnormal temperature point is determined, the following steps are included: ​ ​ ​ 9. The method of claim 8, wherein, ​ 10. The method of claim 8, wherein, ​ According to the temperature signals of the detection points, the temperature signals of the detection points are compared with preset temperature signals of the detection points stored in the detection host, if there is a difference, the temperature signals are abnormal temperature signals, otherwise, the temperature signals are normal temperature signals.

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