Liquid pipeline leakage detection device based on fiber grating strain sensor

Abstract

The utility model relates to the technical field of liquid pipeline leakage detection, in particular to a liquid pipeline leakage detection device based on a fiber bragg grating strain sensor, which comprises a flow guide layer, a water storage tank, the fiber bragg grating strain sensor and an SAP (super absorbent polymer) reaction layer, the diversion layer clings to the bottom of the pipeline, the water-absorbent resin reaction layer is placed in the water storage tank, and the fiber bragg grating strain sensor penetrates through the water storage tank and is placed on the reaction layer, so that when the liquid pipeline leaks, liquid flows to the bottom of the pipeline along the pipe wall under the action of gravity, finally enters the water storage tank through the diversion layer and is absorbed by the reaction layer; the reaction layer absorbs water and expands to extrude the strain sensor, and leakage information is obtained according to the wavelength change of the strain sensor. According to the utility model, the SAP high-molecular water-absorbent resin reaction layer is used as a material for converting leakage signals, the water absorption and water retention capabilities are strong, the leakage signals can be expanded and converted into strain information of the fiber grating strain sensor, and the fiber grating strain sensor can be reused, so that the maintenance and use costs are reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of liquid pipeline leakage detection, in particular to a liquid pipeline leakage detection device based on a fiber grating strain sensor. Background Art

[0002] As an important tool for transporting raw materials such as oil, natural gas, and water, pipelines have gradually become one of the most important means of transportation compared to other modes of transportation such as water, aviation, and railways, along with the rapid development of China's national economy. During the operation of pipelines, pipeline leakage is caused by factors such as aging and corrosion. Pipeline leakage is divided into large leakage and seepage. Large leakage is more intuitive, and the pressure change of the pipeline is more obvious, which is easy to detect. However, for small leakage, it is difficult to detect because the leakage phenomenon is not obvious; thus, it leads to environmental pollution, waste of resources, and even serious accidents. Therefore, it is of great significance to conduct leakage detection on pipelines so as to take corresponding remedial measures.

[0003] The Chinese invention patent document with publication number CN106989201A discloses a liquid pipeline leakage detection device based on a fiber Raman temperature sensor, which realizes the conversion of leakage signals into temperature signals and amplification of leakage signals. The Chinese invention patent document with publication number CN11721217A discloses a pipeline leakage detection device based on a fiber Bragg grating humidity sensor, which realizes the conversion of leakage signals into humidity signals and realizes reuse and detection.

[0004] For the liquid pipeline leakage detection device based on fiber Raman temperature sensor, the signal conversion material used is calcium oxide, which has an irreversible reaction with water and has a high secondary maintenance cost. For the pipeline leakage detection device based on fiber Bragg grating humidity sensor, this device realizes repeated detection through humidity sensor, but when the humidity sensor is restored to use, it needs to be dried by remote electric heating. For some chemical pipelines, the internal medium is mostly flammable, and the use of electric heating is prone to dangerous accidents. Utility Model Content

[0005] In order to solve the above technical problems, the utility model discloses a liquid pipeline leakage detection device based on a fiber grating strain sensor.

[0006] The specific technical solutions are as follows:

[0007] A liquid pipeline leakage detection device based on fiber grating strain sensor, comprising a guide layer, a water storage tank, a fiber grating strain sensor and a SAP polymer water-absorbing resin reaction layer; the guide layer has upper and lower hollows and is fitted to the bottom of the pipeline, the water storage tank and the bottom of the guide layer are detachably connected through a sliding component, and the sliding component comprises a slider and a slide groove; the guide layer extends along the length direction of the pipeline, the top surface has an arc, and both sides are evenly provided with guide holes, and the bottom of both sides respectively extends outward to form a guide edge, and the bottom of the guide edge is a slider; the water storage tank is a groove body with an arc extending along the length direction of the pipeline, and the top surface of the groove body is provided with a slide groove connected to the slide groove. The invention discloses a chute matched with a block, and a drainage hole is evenly opened on the two sides of the chute body. The inside of the chute body is divided into several parts by partitions, and a circular hole is opened on each partition. The fiber grating strain sensor is a rod body, and the two ends are connected with pigtails. A threaded sleeve with an external thread is fastened outside the pigtail. The fiber grating strain sensor is given a certain prestress and then straightened and horizontally passed through each circular hole. The threaded sleeve and the two ends of the water storage tank are fixed by bolts and sealed and waterproofed. The drainage hole is located between the fiber grating strain sensor and the chute; the SAP polymer water-absorbing resin reaction layer is placed in the chute body between the partitions and is placed below the fiber grating strain sensor.

[0008] The inner diameter of the guide hole and the drain hole is ≤5mm, and the hole spacing is less than 10mm.

[0009] A water absorbing and filtering sponge is arranged in the diversion hole and the leakage hole.

[0010] The height of the guide layer is 10 mm, and the height of the water storage tank is 20 mm.

[0011] The distance between two adjacent partitions is 10 mm, and the height of the partition is the same as the height of the water tank.

[0012] The inner diameter of the circular hole on the partition is 3 mm, and the distance between the center of the circular hole and the bottom of the water storage tank is 10 mm.

[0013] The fiber grating strain sensor is a low-temperature-sensitive fiber grating strain sensor.

[0014] The curvature of the top surface of the guide layer fits the pipeline, and the curvature does not exceed 5% of the overall curvature of the pipeline.

[0015] The curvature of the water storage tank is 3% of the pipeline.

[0016] The SAP polymer water-absorbing resin reaction layer is wrapped and packaged with non-woven fabric.

[0017] Compared with the prior art, the utility model has the following beneficial technical effects:

[0018] The utility model has a guide layer close to the bottom of the pipeline, a water-absorbing resin reaction layer placed in a water storage tank, and a fiber grating strain sensor passing through the water storage tank and placed on the reaction layer. When leakage occurs in the liquid pipeline, the liquid will flow to the bottom of the pipeline along the pipe wall due to gravity, and finally enter the water storage tank through the guide layer and be absorbed by the reaction layer. The reaction layer absorbs water and expands, thereby squeezing the strain sensor, and the leakage information is obtained according to the wavelength change of the strain sensor.

[0019] The utility model uses the SAP polymer water-absorbing resin reaction layer as the material for converting leakage signals. The polymer water-absorbing resin is a typical functional polymer material. It can absorb hundreds or even thousands of times its own weight of water and has a strong water retention capacity. It cannot be squeezed out by simple physical methods. It can convert leakage signals into strain information of fiber grating strain sensors, amplify leakage signals, and repeatedly release and absorb water, which can be reused to reduce maintenance and use costs. In addition, under normal temperature and dry conditions, it can spontaneously release water in a short time; when the ambient humidity is high, salt water can also be added to release water, so as to achieve insulation treatment and improve the safety of pipeline operation, especially chemical pipeline operation.

[0020] In the utility model, there is a certain distance between the fiber Bragg grating strain sensor and the SAP polymer water-absorbing resin reaction layer. Even when the humidity in the air is very high, it will not cause changes in the fiber Bragg grating strain sensor, thereby eliminating the influence of environmental humidity. In addition, the fiber Bragg grating strain sensor uses a low-temperature sensitive fiber Bragg grating strain sensor to eliminate the influence of ambient temperature on the leakage signal, thereby improving the accuracy of leakage signal detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the three-dimensional structure of the detection device of the utility model;

[0022] Figure 2 It is a left side view of the detection device of the utility model;

[0023] Figure 3 It is a top view of the detection device of the utility model;

[0024] Figure 4 This is a front view of the detection device of the utility model;

[0025] Figure 5 This is a schematic diagram of the three-dimensional structure of the guide layer of the detection device of the utility model;

[0026] Figure 6 It is a top view of the guide layer of the detection device of the utility model;

[0027] Figure 7 This is a front view of the guide layer of the detection device of the utility model;

[0028] Figure 8 It is a three-dimensional structural schematic diagram of the water storage tank of the detection device of the utility model;

[0029] Fig. 9 This is a schematic cross-sectional view of a water storage tank of the detection device of the utility model;

[0030] In the figure, 1, guide layer; 11, guide hole; 12, guide edge; 13, hollow; 2, water storage tank; 21, partition; 22, circular hole; 23, leakage hole; 3, fiber grating strain sensor; 4, SAP polymer water-absorbing resin reaction layer; 5, sliding component; 51, slider; 52, slide groove; 6, pipeline. DETAILED DESCRIPTION

[0031] The present invention will be further described below in conjunction with the accompanying drawings, but the protection scope of the present invention is not limited to the accompanying drawings.

[0032] Figure 1 It is a three-dimensional structural schematic diagram of the detection device of the utility model. Figure 2 This is a left view of the detection device of the utility model. Figure 3 It is a top view of the detection device of the utility model. Figure 4 The front view of the detection device of the utility model is shown in the figure: the liquid pipeline leakage detection device based on the fiber Bragg grating strain sensor of the utility model is characterized by comprising a guide layer 1, a water storage tank 2, a fiber Bragg grating strain sensor 3 and a SAP polymer water-absorbing resin reaction layer 4; the guide layer 1 has upper and lower hollows 13, which are fitted and installed on the bottom of the pipeline 6, and the water storage tank 2 and the bottom of the guide layer 1 are detachably connected through a sliding component 5 for later inspection and maintenance, and the sliding component 5 includes a slider 51 and a slide groove 52;

[0033] Figure 5 This is a schematic diagram of the three-dimensional structure of the guide layer of the detection device of the utility model. Figure 6 This is a top view of the guide layer of the detection device of the utility model. Figure 7 The front view of the guide layer of the detection device of the utility model is shown in the figure: the guide layer 1 extends along the length direction of the pipe 6, the top surface has an arc, and guide holes 11 are evenly provided on both sides. The bottom of the two sides respectively extends outward to form a guide edge 12, and the bottom of the guide edge 12 is a slider 51;

[0034] Figure 8 This is a three-dimensional structural diagram of the water storage tank of the detection device of the utility model. Fig. 9The schematic diagram of the cross section of the water tank of the detection device of the utility model is shown in the figure: the water tank 2 is a curved tank body extending along the length direction of the pipe 6, the top surface of the tank body is provided with a slide groove 52 matching the slider 51, and a drainage flow hole 23 is evenly provided on the two side surfaces of the tank body. The interior of the tank body is divided into several parts by a partition 21. The partition is provided to ensure that the leaked liquid is concentrated in one water tank and absorbed by the SAP polymer water-absorbing resin reaction layer to prevent it from spreading to other water tanks, thereby obtaining leakage information more quickly. A circular hole 22 is provided on each partition 21. The fiber Bragg grating strain sensor is a rod body, with pigtails connected at both ends. A threaded sleeve with an external thread is fastened outside the pigtail. The fiber Bragg grating strain sensor is given a certain prestress and then straightened and horizontally passed through each circular hole. The threaded sleeve is fixed to both ends of the water storage tank by bolts and sealed and waterproofed. The drain hole 23 is located between the fiber Bragg grating strain sensor 3 and the slide 52. When it rains, the water in the water storage tank will be discharged from the drain hole after it is full. The SAP polymer water-absorbing resin reaction layer 4 is placed in the tank body between the partitions 21 and is placed below the fiber Bragg grating strain sensor 3.

[0035] The inner diameter of the guide hole 11 and the drain hole 23 is ≤5mm, and the hole spacing is less than 10mm. A water-absorbing filter sponge is arranged in the guide hole 11 and the drain hole 23 to filter soil and absorb liquid. The height of the guide layer 1 is 10mm.

[0036] The height of the water tank 2 is 20 mm, and the curvature is 3% of the pipe. The curvature of the top surface of the guide layer 1 fits the pipe 6, and the curvature does not exceed 5% of the overall curvature of the pipe. The distance between two adjacent partitions 21 is 10 mm, and the height of the partition 21 is the same as the height of the water tank 2. The inner diameter of the circular hole 22 on the partition 21 is 3 mm, and the center of the circular hole 22 is 10 mm away from the bottom of the water tank 2.

[0037] The fiber Bragg grating strain sensor 3 is a low temperature sensitive fiber Bragg grating strain sensor 3. The SAP polymer water absorbing resin reaction layer 4 is wrapped and packaged with non-woven fabric.

[0038] During installation, first install the guide layer 1 close to the bottom of the pipe 6. Then give the fiber grating strain sensor 3 a certain prestress and straighten it to pass horizontally through the circular holes 22 of the partition 21. Connect the pigtails at both ends, and screw them to the two ends of the water storage tank 2 and make a sealing and waterproof treatment. Wrap the SAP polymer water-absorbing resin reaction layer 4 with non-woven fabric to prevent it from being lost with the liquid. The SAP polymer water-absorbing resin reaction layer 4 is placed in the tank between the partitions 21 and under the fiber grating strain sensor 3. Then set a water-absorbing filter sponge in the guide hole 11 and the drain hole 23 to filter soil and absorb liquid. Finally, the water storage tank 2 and the guide layer 1 are installed through the sliding assembly.

[0039] During use, when the pipeline 6 leaks, the liquid will flow along the pipe wall to the guide layer 1, and will be collected through the guide hole 11 into the water storage tank 2 and then absorbed by the SAP polymer water-absorbing resin reaction layer 4. The SAP polymer water-absorbing resin reaction layer 4 will expand rapidly and increase in volume, so that the grating strain sensor 3 will be squeezed and produce obvious strain changes, thereby amplifying the leakage information of the pipeline 6 and converting it into fiber grating strain information. The SAP polymer water-absorbing resin reaction layer can absorb liquids such as water and petroleum to expand, and can release water under dry, normal temperature, and high temperature conditions, and can be reused. When it is in an environment with high humidity, that is, when the water-releasing environment conditions are not met, adding salt water can make the SAP polymer water-absorbing resin reaction layer that has absorbed water quickly release water, thereby achieving the effect of repeated use. It should be noted that there is a distance between the fiber grating strain sensors. When the ambient air humidity is high, the SAP polymer water-absorbing resin reaction layer absorbs moisture in the air, which is not enough to expand it to the fiber grating strain sensor, thereby eliminating the influence of the ambient humidity factor. Furthermore, the fiber Bragg grating strain sensor in the utility model uses a low-temperature-sensitive fiber Bragg grating strain sensor to avoid the influence of the ambient temperature on the leakage signal.

Claims

1. A liquid pipeline leakage detection device based on fiber grating strain sensor, characterized in that: It includes a guide layer, a water storage tank, a fiber Bragg grating strain sensor and a SAP polymer water-absorbing resin reaction layer; the guide layer is hollow at the top and bottom and is installed at the bottom of the pipeline; the water storage tank and the bottom of the guide layer are detachably connected through a sliding component, and the sliding component includes a slider and a slide groove; the guide layer extends along the length of the pipeline, the top surface has an arc, and guide holes are evenly arranged on both sides, and the bottom of the two sides respectively extends outward to form a guide edge, and the bottom of the guide edge is a slider; the water storage tank is a trough body with an arc extending along the length of the pipeline, and the top surface of the trough body is provided with a slide groove matching the slider, and the two sides of the trough body are A drainage hole is evenly opened on each side, and the interior of the tank is divided into several parts by partitions. A circular hole is opened on each partition. The fiber grating strain sensor is a rod body, and the pigtails are connected at both ends. A threaded sleeve with an external thread is fastened outside the pigtail. The fiber grating strain sensor is given a certain prestress and then straightened and horizontally passes through each circular hole. The threaded sleeve is fixed to the two ends of the water storage tank by bolts and sealed and waterproofed. The drainage hole is located between the fiber grating strain sensor and the slide groove; the SAP polymer water-absorbing resin reaction layer is placed in the tank between the partitions and placed below the fiber grating strain sensor.

2. The liquid pipeline leakage detection device based on fiber grating strain sensor according to claim 1 is characterized in that: The inner diameter of the guide hole and the drain hole is ≤5mm, and the hole spacing is less than 10mm.

3. The liquid pipeline leakage detection device based on fiber grating strain sensor according to claim 1 is characterized in that: A water absorbing and filtering sponge is arranged in the diversion hole and the leakage hole.

4. The liquid pipeline leakage detection device based on fiber grating strain sensor according to claim 1 is characterized in that: The height of the guide layer is 10 mm, and the height of the water storage tank is 20 mm.

5. The liquid pipeline leakage detection device based on fiber grating strain sensor according to claim 1 is characterized in that: The distance between two adjacent partitions is 10 mm, and the height of the partition is the same as the height of the water tank.

6. The liquid pipeline leakage detection device based on fiber grating strain sensor according to claim 1 is characterized in that: The inner diameter of the circular hole on the partition is 3 mm, and the distance between the center of the circular hole and the bottom of the water storage tank is 10 mm.

7. The liquid pipeline leakage detection device based on fiber grating strain sensor according to claim 1 is characterized in that: The fiber grating strain sensor is a low-temperature-sensitive fiber grating strain sensor.

8. The liquid pipeline leakage detection device based on fiber grating strain sensor according to claim 1, characterized in that: The curvature of the top surface of the guide layer fits the pipeline, and the curvature does not exceed 5% of the overall curvature of the pipeline.

9. The liquid pipeline leakage detection device based on fiber grating strain sensor according to claim 1, characterized in that: The curvature of the water storage tank is 3% of the pipeline.

10. The liquid pipeline leakage detection device based on fiber grating strain sensor according to claim 1, characterized in that: The SAP polymer water-absorbing resin reaction layer is wrapped and packaged with non-woven fabric.

Images