A pipeline temperature detection system using a spiral type temperature measurement optical fiber

Abstract

The utility model discloses a kind of pipeline temperature detection system using spiral temperature measuring optical fiber, and low-temperature pipeline is successively wrapped with inner cold insulation layer, intermediate cold insulation layer and outer cold insulation layer from inside to outside;Spiral temperature measuring optical fiber is spirally arranged between low-temperature pipeline and inner cold insulation layer, to monitor the temperature difference on the surface of low-temperature pipeline;First intermediate temperature measuring optical fiber is spirally arranged between inner cold insulation layer and intermediate cold insulation layer, to monitor the temperature difference on the surface of inner cold insulation layer;Second intermediate temperature measuring optical fiber is spirally arranged between intermediate cold insulation layer and outer cold insulation layer, to monitor the temperature difference on the surface of intermediate cold insulation layer;Outer cold insulation layer outside spirally arranged outer temperature measuring optical fiber, to monitor the temperature difference on the surface of outer cold insulation layer.The temperature detection system uses spiral temperature measuring optical fiber technology, realizes the temperature monitoring of LNG pipeline full length, all azimuth, effectively eliminates monitoring blind area, can find crack, cold leakage and other hidden dangers of pipeline arbitrary position in time, greatly improve the accuracy and reliability of monitoring.

Description

Technical Field

[0001] This utility model relates to the field of liquefied natural gas (LNG) pipeline safety monitoring technology, and in particular to a pipeline temperature detection system using a spiral-shaped temperature measuring optical fiber. Background Technology

[0002] In today's industrial and energy sectors, LNG, as a clean and efficient energy source, is playing an increasingly important role in global energy consumption. The safe and timely commissioning of LNG receiving terminals is crucial for their stable and efficient operation. Currently, LNG transmission pipelines primarily rely on traditional monitoring methods for pre-cooling control and long-term safe operation during transmission.

[0003] Traditional temperature monitoring typically employs single-point temperature sensors. These sensors work by using internal thermistor elements, such as thermocouples or resistance temperature detectors (RTDs), to convert temperature changes into electrical signals for measurement. Structurally, each sensor has its own independent signal line and interface, which are connected to the monitoring system via wiring.

[0004] In applications, these sensors are distributed and installed at critical locations on pipelines to acquire temperature data. However, conventional infrared thermal imagers are limited by detection distance and environmental interference, making them unsuitable for long-term online monitoring in complex environments such as pipe racks.

[0005] Problems and shortcomings of existing technologies:

[0006] 1. Incomplete monitoring coverage: Traditional single-point temperature sensors can only obtain temperature information at the installation point, and cannot achieve full coverage monitoring of the pipeline. There are a lot of monitoring blind spots, making it difficult to detect potential hazards such as cracks and cold leakage at locations in the pipeline where the temperature sensor is not installed.

[0007] 2. Complex wiring: Each temperature sensor requires a signal line and interface. In large-scale pipeline monitoring, the wiring project is cumbersome, costly, and difficult to troubleshoot. Due to the large number of lines, problems such as line aging and poor contact are also prone to occur, affecting the stability and accuracy of monitoring.

[0008] 3. Unable to reconstruct the three-dimensional temperature field of the insulation layer and unable to accurately locate the source of cold leakage: Traditional temperature measurement often measures the temperature data of fixed points in the circuit, which is difficult to respond to cold leakage in a timely manner and requires manual on-site determination of the source of cold leakage. Utility Model Content

[0009] The purpose of this invention is to provide a pipeline temperature detection system using a spiral-shaped temperature-sensing optical fiber, in order to solve the defects of traditional single-point temperature sensors in monitoring LNG transmission pipelines.

[0010] To solve the above-mentioned technical problems, this utility model provides a pipeline temperature detection system using a spiral temperature measuring optical fiber, wherein the low-temperature pipeline is wrapped with an inner cold insulation layer, a middle cold insulation layer and an outer cold insulation layer from the inside to the outside.

[0011] An internal temperature-measuring optical fiber is spirally arranged between the low-temperature pipe and the inner cold insulation layer to monitor the temperature difference on the surface of the low-temperature pipe.

[0012] A first temperature-measuring optical fiber is spirally arranged between the inner cold insulation layer and the middle cold insulation layer to monitor the temperature difference on the surface of the inner cold insulation layer.

[0013] A second temperature-measuring optical fiber is spirally arranged between the intermediate cold insulation layer and the outer cold insulation layer to monitor the temperature difference on the surface of the intermediate cold insulation layer.

[0014] The outer cold insulation layer is spirally arranged with external temperature measuring optical fibers to monitor the temperature difference on the surface of the outer cold insulation layer.

[0015] Preferably, the ends of the inner temperature measuring fiber, the first intermediate temperature measuring fiber, the second intermediate temperature measuring fiber, and the outer temperature measuring fiber are all connected to a laser source. The laser emitted by the laser source is amplified by an optical signal pulse amplifier and then enters the temperature measuring fiber, where Raman scattering occurs at various positions.

[0016] Preferably, the inner temperature-measuring fiber, the first intermediate temperature-measuring fiber, and the end of the inner temperature-measuring fiber are also connected to the data acquisition module. After the laser is scattered in the temperature-measuring fiber, it will form echo signals of Stokes light and anti-Stokes light of different wavelengths. The echo signals are converted by wavelength division multiplexer and APD photoelectric conversion module and then enter the data acquisition module. The data acquisition module acquires the light intensity signals of at least two beams of light. Based on the principle that the light intensity is different at different temperatures, the temperature of the reflection point is obtained by analyzing the light intensity change.

[0017] Preferably, an acousto-optic modulator is provided between the laser source and the optical signal pulse amplifier. The acousto-optic modulator rapidly switches the on / off state of the laser through a radio frequency drive signal to form a high-contrast pulse output.

[0018] Preferably, the internal temperature measuring fiber is an armored temperature measuring fiber formed by sheathing a circular stainless steel tube.

[0019] Preferably, the internal temperature-measuring optical fiber is an armored temperature-measuring optical fiber formed by an arc-shaped stainless steel cover.

[0020] Preferably, the inner temperature measuring fiber, the first intermediate temperature measuring fiber, the second intermediate temperature measuring fiber, and the outer temperature measuring fiber are arranged in an alternating spiral pattern.

[0021] Compared with the prior art, the beneficial effects of this utility model are:

[0022] This temperature detection system employs spiral-type fiber optic temperature sensing technology to achieve full-length, all-around temperature monitoring of LNG pipelines. This effectively eliminates monitoring blind spots and can promptly detect potential hazards such as cracks and cold water leaks at any location within the pipeline, significantly improving monitoring accuracy and reliability. Compared to traditional single-point sensors, it greatly reduces the number of wires, lowering wiring costs and construction difficulty. Simultaneously, it reduces potential line failure points, decreasing maintenance workload and costs, and improving the stability of the monitoring system. Attached Figure Description

[0023] Figure 1 This is an axial layout diagram of the spiral temperature measuring optical fiber provided by this utility model in a low-temperature pipeline;

[0024] Figure 2 This is a radial layout diagram of the spiral temperature measuring optical fiber provided by this utility model in a low-temperature pipeline;

[0025] Figure 3 This is a schematic diagram of a pipeline temperature detection system using a spiral-shaped temperature-sensing optical fiber, provided by this utility model.

[0026] Figure 4 This is a schematic diagram of the structure of the circular stainless steel tube sleeved to form an armored temperature measuring optical fiber provided by this utility model;

[0027] Figure 5 This is a schematic diagram of the structure of the arc-shaped stainless steel cover forming an armored temperature measuring optical fiber provided by this utility model.

[0028] In the diagram: 10. Low-temperature pipeline; 2. Laser source; 3. Optical signal pulse amplifier; 4. Data acquisition module; 5. APD photoelectric conversion module; 6. Wavelength division multiplexer; 7. Acousto-optic modulator; 11. Inner temperature measuring fiber; 12. First intermediate temperature measuring fiber; 13. Second intermediate temperature measuring fiber; 14. Outer temperature measuring fiber; 20. Inner cold insulation layer; 30. Intermediate cold insulation layer; 40. Outer cold insulation layer. Detailed Implementation

[0029] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. The advantages and features of the present invention will become clearer from the following description and claims. It should be noted that the drawings are all in a very simplified form and use non-precise proportions, and are only used to facilitate and clarify the illustration of the embodiments of the present invention.

[0030] In the description of this utility model, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0031] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances. Example

[0032] This invention provides a pipeline temperature detection system using a spiral-shaped temperature-sensing optical fiber. Please refer to [link / reference]. Figure 1 and Figure 2 The low-temperature pipe 10 is wrapped with an inner cold insulation layer 20, a middle cold insulation layer 30 and an outer cold insulation layer 40 from the inside to the outside.

[0033] Specifically, an inner temperature-measuring optical fiber 11 is spirally arranged between the low-temperature pipe 10 and the inner cold insulation layer 20 to monitor the temperature difference on the surface of the low-temperature pipe 10; a first intermediate temperature-measuring optical fiber 12 is spirally arranged between the inner cold insulation layer 20 and the intermediate cold insulation layer 30 to monitor the temperature difference on the surface of the inner cold insulation layer 20; a second intermediate temperature-measuring optical fiber 13 is spirally arranged between the intermediate cold insulation layer 30 and the outer cold insulation layer 40 to monitor the temperature difference on the surface of the intermediate cold insulation layer 30; and an outer temperature-measuring optical fiber 14 is spirally arranged on the outer side of the outer cold insulation layer 40 to monitor the temperature difference on the surface of the outer cold insulation layer 40.

[0034] In this embodiment, the inner temperature measuring fiber 11, the first intermediate temperature measuring fiber 12, the second intermediate temperature measuring fiber 13, and the outer temperature measuring fiber 14 are arranged in an alternating spiral pattern.

[0035] For details, please refer to Figure 3 The ends of the inner temperature measuring fiber 11, the first intermediate temperature measuring fiber 12, the second intermediate temperature measuring fiber 13, and the outer temperature measuring fiber 14 are all connected to the laser source 2. The laser emitted by the laser source 2 is amplified by the optical signal pulse amplifier 3 and then enters the temperature measuring fiber, where Raman scattering occurs at various positions of the temperature measuring fiber.

[0036] Furthermore, the inner temperature measuring fiber 11, the first intermediate temperature measuring fiber 12, and the end of the inner temperature measuring fiber 11 are also connected to the data acquisition module 4. After the laser is scattered in the temperature measuring fiber, it will form echo signals of Stokes light and anti-Stokes light of different wavelengths. After the echo signals are converted by the wavelength division multiplexer 6 and the APD photoelectric conversion module 5, they enter the data acquisition module 4. The data acquisition module 4 acquires the light intensity signals of at least two beams of light. Based on the principle that the light intensity is different at different temperatures, the temperature of the reflection point is obtained by analyzing the change in light intensity.

[0037] Furthermore, an acousto-optic modulator 7 is provided between the laser source 2 and the optical signal pulse amplifier 3. The acousto-optic modulator 7 rapidly switches the on / off state of the laser through a radio frequency drive signal to form a high-contrast pulse output.

[0038] In this embodiment, the laser source 2 is GY-LASER-1550-30, the optical signal pulse amplifier 3 is GY-EDFA-RA, the data acquisition module 4 is GY-DTS-200-DAQ, the APD photoelectric conversion module 5 is APD22-100M, and the wavelength division multiplexer 6 is Ouyi Optoelectronics 1x3 Raman WDM.

[0039] In this embodiment, as Figure 4 As shown, depending on the temperature, for the extreme low temperature conditions (<-100°) of the inner layer, the inner temperature measuring fiber 11 is formed by sheathing a circular stainless steel tube 101 to form an armored temperature measuring fiber, which has good mechanical strength, waterproof, leak-proof and good thermal conductivity, and is suitable for low temperature LNG pipeline monitoring.

[0040] In another embodiment, such as Figure 5 As shown, the internal temperature measuring fiber 11 is armored with an arc-shaped stainless steel cover 102.

[0041] This temperature detection system employs spiral-type fiber optic temperature sensing technology to achieve full-length, all-around temperature monitoring of LNG pipelines. This effectively eliminates monitoring blind spots and can promptly detect potential hazards such as cracks and cold water leaks at any location within the pipeline, significantly improving monitoring accuracy and reliability. Compared to traditional single-point sensors, it greatly reduces the number of wires, lowering wiring costs and construction difficulty. Simultaneously, it reduces potential line failure points, decreasing maintenance workload and costs, and improving the stability of the monitoring system.

[0042] The above description is only a description of the preferred embodiment of the present utility model and is not intended to limit the scope of the present utility model in any way. Any changes or modifications made by those skilled in the art based on the above disclosure shall fall within the protection scope of the claims.

Claims

1. A pipeline temperature detection system employing a spiral-shaped temperature-sensing optical fiber, characterized in that, The low-temperature pipe (10) is wrapped with an inner cold insulation layer (20), a middle cold insulation layer (30) and an outer cold insulation layer (40) from the inside to the outside. An internal temperature measuring fiber (11) is spirally arranged between the low-temperature pipe (10) and the inner cold insulation layer (20) to monitor the temperature difference on the surface of the low-temperature pipe (10); A first intermediate temperature-measuring optical fiber (12) is spirally arranged between the inner cold insulation layer (20) and the intermediate cold insulation layer (30) to monitor the temperature difference on the surface of the inner cold insulation layer (20); A second temperature-measuring optical fiber (13) is spirally arranged between the intermediate cold insulation layer (30) and the outer cold insulation layer (40) to monitor the temperature difference on the surface of the intermediate cold insulation layer (30); The outer cold insulation layer (40) is spirally provided with an external temperature measuring fiber (14) to monitor the temperature difference on the surface of the outer cold insulation layer (40).

2. The pipeline temperature detection system using a spiral-shaped temperature-sensing optical fiber as described in claim 1, characterized in that, The ends of the inner temperature measuring fiber (11), the first intermediate temperature measuring fiber (12), the second intermediate temperature measuring fiber (13), and the outer temperature measuring fiber (14) are all connected to the laser source (2). The laser emitted by the laser source (2) is amplified by the optical signal pulse amplifier (3) and enters the temperature measuring fiber, where Raman scattering occurs at various positions of the temperature measuring fiber.

3. A pipeline temperature detection system using a spiral-shaped temperature-sensing optical fiber as described in claim 2, characterized in that, The ends of the internal temperature measuring fiber (11), the first intermediate temperature measuring fiber (12), and the internal temperature measuring fiber (11) are also connected to the data acquisition module (4). After the laser is scattered in the temperature measuring fiber, it will form echo signals of Stokes light and anti-Stokes light of different wavelengths. After the echo signals are converted by the wavelength division multiplexer (6) and the APD photoelectric conversion module (5), they enter the data acquisition module (4). The data acquisition module (4) acquires the light intensity signals of at least two beams of light. Based on the principle that the light intensity is different at different temperatures, the temperature of the reflection point is obtained by analyzing the change in light intensity.

4. A pipeline temperature detection system using a spiral-shaped temperature-sensing optical fiber as described in claim 3, characterized in that, An acousto-optic modulator (7) is provided between the laser source (2) and the optical signal pulse amplifier (3). The acousto-optic modulator (7) quickly switches the on / off state of the laser through a radio frequency drive signal to form a high-contrast pulse output.

5. A pipeline temperature detection system using a spiral-shaped temperature-sensing optical fiber as described in claim 1, characterized in that, The internal temperature measuring fiber (11) is formed by sheathing a circular stainless steel tube (101).

6. A pipeline temperature detection system using a spiral-shaped temperature-sensing optical fiber as described in claim 1, characterized in that, The internal temperature measuring fiber (11) is armored by being fitted with an arc-shaped stainless steel cover (102).

7. A pipeline temperature detection system using a spiral-shaped temperature-sensing optical fiber as described in claim 1, characterized in that, The inner temperature measuring fiber (11), the first intermediate temperature measuring fiber (12), the second intermediate temperature measuring fiber (13), and the outer temperature measuring fiber (14) are arranged in an alternating spiral pattern.

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