A novel fiber Bragg grating probe for in-situ monitoring of hydraulic shear stress

Abstract

The present invention discloses a novel fiber Bragg grating probe for in-situ monitoring of hydraulic shear force, comprising a No. 1 FC connector, a No. 2 FC connector, a No. 1 flange, a No. 3 FC connector, a hollow connecting tube, a No. 4 FC connector, a No. 2 flange, a No. 5 FC connector, a hollow probe tube, and a needle connected in sequence from left to right; a jumper connected to the No. 3 FC connector passes through the hollow connecting tube and is connected to the No. 4 FC connector; a jumper connected to the No. 5 FC connector passes through the hollow probe tube and the needle in sequence, and the end of the jumper is connected to the grating, the grating extends out of the needle for a certain length, and a cap is used to protect the grating. The present invention achieves the purpose of flexible assembly and disassembly through the assembly of various parts. In the actual in-situ monitoring of hydraulics, after simple and convenient assembly, it can be extended into the solution to be tested to carry out in-situ monitoring of hydraulic shear force in a small space.

Description

Technical Field

[0001] The invention belongs to the technical field of water treatment, and more specifically, relates to a novel fiber Bragg grating probe for in-situ monitoring of hydraulic shear force state. Background Art

[0002] Fiber Bragg gratings, i.e., gratings with periodic spatial phase distribution formed in the fiber core, have a wide reflection bandwidth range, low additional loss, small size, are easy to couple with optical fiber, can be integrated with other optical devices, and are not affected by environmental dust, among other excellent properties. They are currently widely used in the field of optical fiber sensors (displacement, velocity, acceleration, and temperature measurement). In addition, due to their small size and corrosion resistance, they can be used for in-situ monitoring of the hydraulic conditions of flow fields in tiny spaces. However, due to their inherent fragility, they are greatly limited in in-situ monitoring of water environments. Therefore, it is particularly important to realize the encapsulation of fiber Bragg gratings to adapt to various underwater environments. Summary of the invention

[0003] The purpose of the present invention is to overcome the deficiencies in the prior art and to provide a novel fiber Bragg grating probe for in-situ monitoring of hydraulic shear force.

[0004] The objectives of the present invention are achieved through the following technical solutions.

[0005] The novel fiber Bragg grating probe for in-situ monitoring of hydraulic shear force of the present invention comprises a No. 1 FC connector, a No. 2 FC connector, a No. 1 flange, a No. 3 FC connector, a hollow connecting tube, a No. 4 FC connector, a No. 2 flange, a No. 5 FC connector, a hollow probe tube, and a needle, which are sequentially connected from left to right;

[0006] The No. 1 FC connector and the No. 2 FC connector are connected by a jumper wire, the No. 2 FC connector and the No. 1 flange are connected by threads, the No. 1 flange and the No. 3 FC connector are connected by threads, the No. 3 FC connector and the hollow connecting pipe are connected by AB glue, the hollow connecting pipe and the No. 4 FC connector are connected by AB glue, the No. 4 FC connector and the No. 2 flange are connected by threads, the No. 2 flange and the No. 5 FC connector are connected by threads, and the No. 5 FC connector and the hollow probe tube are connected by AB glue;

[0007] Among them, the jumper connected to the No. 3 FC connector passes through the hollow connecting tube and is connected to the No. 4 FC connector; the jumper connected to the No. 5 FC connector passes through the hollow probe tube and the needle in sequence, and the end of the jumper is connected to the grating, the grating extends out of the needle for a certain length, and the grating is protected by a cap.

[0008] The jumper is a protective sheath that uses a plastic sheath to wrap a bare optical fiber.

[0009] The jumper between the No. 3 FC connector and the No. 4 FC connector is welded by a grating welding machine, and the jumper between the No. 5 FC probe and the grating is welded by a grating welding machine.

[0010] Compared with the prior art, the technical solution of the present invention has the following beneficial effects:

[0011] (1) The assembly design of the present invention increases the operability of the Bragg grating during hydraulic monitoring.

[0012] (2) The present invention can customize hollow connecting tubes of different lengths and materials, which are suitable for testing water environments of different depths.

[0013] (3) The present invention can be assembled anytime and anywhere, which is simple and easy.

[0014] (4) The designs of the two hollow probe tubes of the present invention can respectively test the lateral and longitudinal hydraulic changes.

[0015] The invention solves the problem of the fragility of Bragg optical fiber in the actual testing process, greatly increases its real-time in-situ monitoring capability of hydraulic state in various environments, and improves convenience. During the detection process, multi-point in-situ detection of the solution can be achieved. The comprehensiveness and accuracy of the test results are improved. The invention has low detection cost, light equipment, safe operation, and little influence from the reaction medium. In addition, due to the advantages of the Bragg grating itself, such as small size and corrosion resistance, the operability of the device is greatly improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the assembly scheme of the novel fiber Bragg grating probe of the present invention.

[0017] Figure 2 It is a schematic diagram of the connection part in the present invention.

[0018] Figure 3 It is a real-time change diagram of shear force.

[0019] Figure markings: 1- FC connector No. 1; 2- FC connector No. 2; 3- flange No. 1; 4- FC connector No. 3; 5- hollow connecting tube; 6- FC connector No. 4; 7- flange No. 2; 8- FC connector No. 5; 9- hollow probe tube; 10- needle; 11- grating; 12- cap. DETAILED DESCRIPTION

[0020] The present invention will be further described below in conjunction with the accompanying drawings.

[0021] like Figure 1 and Figure 2As shown, the novel fiber Bragg grating probe for in-situ monitoring of hydraulic shear force of the present invention includes a No. 1 FC connector 1, a No. 2 FC connector 2, a No. 1 flange 3, a No. 3 FC connector 4, a hollow connecting tube 5, a No. 4 FC connector 6, a No. 2 flange 7, a No. 5 FC connector 8, a hollow probe tube 9, and a needle 10, which are sequentially connected from left to right.

[0022] The No. 1 FC connector 1 and the No. 2 FC connector 2 are connected by a jumper wire, the No. 2 FC connector 2 and the No. 1 flange 3 are connected by threads, the No. 1 flange 3 and the No. 3 FC connector 4 are connected by threads, the No. 3 FC connector 4 and the hollow connecting pipe 5 are connected by AB glue, the hollow connecting pipe 5 and the No. 4 FC connector 6 are connected by AB glue, the No. 4 FC connector 6 and the No. 2 flange 7 are connected by threads, the No. 2 flange 7 and the No. 5 FC connector 8 are connected by threads, and the No. 5 FC connector 8 and the hollow probe tube 9 are connected by AB glue.

[0023] The jumper is a protective sheath that wraps a bare optical fiber with a plastic sheath. The jumper connected to the No. 3 FC connector 4 passes through the hollow connecting tube 5 and is connected to the No. 4 FC connector 6. The jumper connected to the No. 5 FC connector 8 passes through the hollow probe tube 9 and the needle 10 in sequence, and the end of the jumper is connected to the grating 11. After the jumper connected to the No. 5 FC connector 8 passes through the hollow probe tube 9, AB glue is needed to fix the jumper. One end of the needle 10 is inserted into the hollow probe tube 9 for about 4 mm and is fixed with AB glue. The grating 11 extends out of the needle 10 by a certain length. The needle 10 and the grating 11 do not need to be fixed additionally, and the cap 12 is used to protect the grating 11.

[0024] The jumper between the No. 3 FC connector 4 and the No. 4 FC connector 6 is welded by a grating welding machine. Specifically, one end of the jumper of the No. 3 FC connector 4 is first inserted into the hollow connecting tube 5 until it reaches the other end, and then the bare optical fiber in the jumper is welded with the bare optical fiber in the jumper at the end of the No. 4 FC connector 6 by the grating welding machine, and the excess jumper is placed in the hollow connecting tube 5 after welding. The jumper at the end of the No. 5 FC probe 8 is welded with the grating 11 by the grating welding machine, and then inserted into the hollow probe tube 9 until it passes through the needle 10, and the extended length can be 10 mm (this is the grid area length, which can be adjusted according to the specific grid area length).

[0025] The hollow connecting tube 5 and the No. 4 FC connector 6 are connected by AB glue. Specifically, the jumper wire at one end of the No. 4 FC connector 6 is inserted into the hollow connecting tube 5, and then the AB glue is injected into the groove at the head of the hollow connecting tube 5, and the No. 4 FC connector 6 is further connected to the groove, so as to achieve the purpose of packaging. Figure 2 The packaging method of the No. 5 FC connector 8 and the hollow probe tube 9 is consistent with the packaging method of the hollow connecting tube 5 and the No. 4 FC connector 6 .

[0026] The No. 5 FC connector 8, hollow probe tube 9, needle 10, grating 11 and cap 12 constitute a probe area, which can realize the change of grating angle. This solution only provides grating angles of 0 degree and 90 degree, but is not limited to these two angles and can be customized according to actual conditions.

[0027] Embodiment 1:

[0028] In the novel fiber Bragg grating probe for in-situ monitoring of hydraulic shear force of the present invention, the No. 1 FC connector 1 is connected to the fiber Bragg grating demodulator, and the length of the jumper between the No. 1 FC connector 1 and the No. 2 FC connector 2 can be customized, and the length here is 1m. The length and diameter of the hollow connecting tube 5 can be customized according to the actual application. Here, in order to reduce its influence on the hydraulics of the monitoring process, a hollow tube with a diameter of 10mm at both ends and a diameter of 4mm in the middle is adopted, and the length is 100mm and 200mm. The diameter of the hollow probe tube 9 is 4mm and the length is 100mm. The total length of the needle 10 is 18mm, the needle tube length is 6.5mm, the outer diameter is 0.5mm, and the inner diameter is 0.26mm. The needle 10 can be adjusted according to the actual situation.

[0029] The specific implementation process of the present invention is as follows: connect the No. 1 FC connector 1 to the fiber Bragg grating demodulator, and then further feed the signal back to the computer. The force change can be directly presented through the supporting software. The result is as follows: Figure 3 As shown, when there is no interference from external forces, the signal is in a stable stage. When there is interference from external forces, the signal changes significantly.

[0030] Although the functions and working processes of the present invention have been described above in conjunction with the accompanying drawings, the present invention is not limited to the above-mentioned specific functions and working processes, and the above-mentioned specific implementation methods are merely illustrative rather than restrictive. Under the guidance of the present invention, ordinary technicians in this field can also make many forms without departing from the scope of protection of the purpose of the present invention and the claims, which are all within the protection of the present invention.

Claims

1. A novel fiber Bragg grating probe for in-situ monitoring of hydraulic shear force, characterized in that: It includes, connected from left to right in sequence, a No. 1 FC connector (1), a No. 2 FC connector (2), a No. 1 flange (3), a No. 3 FC connector (4), a hollow connecting tube (5), a No. 4 FC connector (6), a No. 2 flange (7), a No. 5 FC connector (8), a hollow probe tube (9), and a needle (10); The No. 1 FC connector (1) and the No. 2 FC connector (2) are connected by a jumper wire, the No. 2 FC connector (2) and the No. 1 flange (3) are connected by threads, the No. 1 flange (3) and the No. 3 FC connector (4) are connected by threads, the No. 3 FC connector (4) and the hollow connecting pipe (5) are connected by AB glue, the hollow connecting pipe (5) and the No. 4 FC connector (6) are connected by AB glue, the No. 4 FC connector (6) and the No. 2 flange (7) are connected by threads, the No. 2 flange (7) and the No. 5 FC connector (8) are connected by threads, and the No. 5 FC connector (8) and the hollow probe tube (9) are connected by AB glue; The jumper connected to the No. 3 FC connector (4) passes through the hollow connecting tube (5) and is connected to the No. 4 FC connector (6); the jumper connected to the No. 5 FC connector (8) passes through the hollow probe tube (9) and the needle (10) in sequence, and the end of the jumper is connected to the grating (11), the grating (11) extends out of the needle (10) by a certain length, and the cap (12) is used to protect the grating (11); The hollow connecting tubes (5) of different lengths and materials are customized according to needs, and the angle between the hollow connecting tube (9) and the needle (10) is adjusted according to actual needs. The No. 5 FC connector (8), the hollow probe tube (9), the needle (10), the grating (11) and the cap (12) constitute a probe area, which realizes the change of the grating angle.

2. The novel fiber Bragg grating probe for in-situ monitoring of hydraulic shear force according to claim 1, characterized in that: The jumper is a protective sheath that uses a plastic sheath to wrap a bare optical fiber.

3. The novel fiber Bragg grating probe for in-situ monitoring of hydraulic state according to claim 1, characterized in that: The jumper wire between the No. 3 FC connector (4) and the No. 4 FC connector (6) is welded by a grating welding machine, and the jumper wire between the No. 5 FC probe (8) and the grating (11) is welded by a grating welding machine.

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