CN105698696A - Distributed optical fiber sensibility enhancing device - Google Patents

Abstract

A distributed optical fiber sensibility enhancing device relates to strain sensibility enhancing technology of distributed optical fibers and aims to solve a problem that distributed optical fibers are difficult to monitor micro strain in the prior art. According to the invention, a tube hoop of the device is ring-shaped. An optical fiber channel used for accommodating the distributed optical fibers is arranged in the tube hoop. The tube hoop is provided with three No.1 openings with equal lengths. Each No.1 opening is provided with at least on rubber connection piece. The rubber connection pieces are used for connecting two ends of the No.1 openings. The tube hoop is also provided with a No.2 opening. A fixing structure device is arranged outside the No.2 opening and is used for fixing the two ends of the No.2 opening. The two ends of each of the No.1 opening and the No.2 opening is each provided with a packing component fixedly. The packing components are used for fixing the distributed optical fibers. The device provided by the invention can amplify micro strain outside an optical fiber monitoring range by hundreds or thousands of times, so that the sensibility of the optical fibers to strain is enhanced. The device provided by the invention is suitable for a field of online monitoring of municipal administration engineering, petroleum engineering or natural gas pipelines.

Description

Distribution type fiber-optic enhanced sensitivity device

Technical field

The present invention relates to distributed fibre-optic strain sensitization technology。

Background technology

At present, distribution type fiber-optic is at bridge, the health monitoring of building etc. there is relatively broad application, but, for the material that the elastic modelling quantity such as such as municipal administration cast-iron pipe are bigger, the interior hoop strain caused by variation in water pressure of pipeline is typically smaller than the monitoring sensitivity of distribution type fiber-optic, thus distribution type fiber-optic is difficult to existing effective strain monitoring in fact, which greatly limits the distribution type fiber-optic popularization in municipal administration, oil or natural gas line on-line monitoring field。

Summary of the invention

The invention aims to solve the problem that existing distribution type fiber-optic is difficult to monitoring small strain, it is provided that a kind of distribution type fiber-optic enhanced sensitivity device。

Distribution type fiber-optic enhanced sensitivity device of the present invention includes metal pipe collar 1,2, eight metal package parts 3 of distribution type fiber-optic, fixed structure 4 and multiple rubber and connects sheet 5；

Described pipe collar 1 is in circular, for being fixed on pipeline external, pipe collar 1 circumferential direction inside direction has the optical-fibre channel of circle, described optical-fibre channel is used for placing distribution type fiber-optic 2, pipe collar 1 has three isometric openings, pipe collar 1 is divided into three sections by three openings, and each opening part is additionally provided with at least one rubber and connects sheet 5, and described rubber connects sheet 5 for connecting the two ends of an opening；

Being additionally provided with No. two openings on pipe collar 1, fixed structure 4 is arranged on the outside of described No. two openings, for fixing the two ends of No. two openings；

Package parts 3 are fixed at the two ends of each opening and No. two openings respectively, and described package parts 3 are for stationary distribution formula optical fiber。

Small strain beyond fiber-optic monitoring scope can be carried out the amplification of hundreds times to thousands of times by distribution type fiber-optic enhanced sensitivity device of the present invention, to increase the sensitivity of optical fiber impression strain, such as the armored concrete water-supply-pipe of DN2200, pipe surface microstrain can be exaggerated about 4600 times, the minimum monitoring sensitivity requirement of distribution type fiber-optic can be reached, from realizing the distribution type fiber-optic online health monitoring at pipelines such as municipal administration, natural gas line, oil, pipe safety and control pipeline is most important。When this enhanced sensitivity device is installed, only several tested points need to be selected on pipeline section to install according to result of calculation, thus avoiding the various expenses that large area excavation produces, and this device is quick and easy for installation, have only to respective tube hoop clip is contained in pipe under test outer surface, both it is suitable for the interim health monitoring of pipeline, is suitable for again long term monitoring。

Accompanying drawing explanation

Fig. 1 is the profile of the distribution type fiber-optic enhanced sensitivity device described in embodiment one, and wherein 7 represent inner-walls of duct；

Fig. 2 is the scheme of installation of the distribution type fiber-optic enhanced sensitivity device described in embodiment one；

Fig. 3 is the structural representation of an opening in embodiment one and five；

Fig. 4 is the structural representation of the fixed structure in embodiment three, and wherein plus sige and minus sign represent that distribution type fiber-optic extends forward and extends back respectively；

Fig. 5 is the structural representation of the fixed structure in embodiment four。

Detailed description of the invention

Detailed description of the invention one: present embodiment is described in conjunction with Fig. 1 to Fig. 3, the distribution type fiber-optic enhanced sensitivity device described in present embodiment includes metal pipe collar 1,2, eight metal package parts 3 of distribution type fiber-optic, fixed structure 4 and multiple rubber and connects sheet 5；

Described pipe collar 1 is in circular, for being fixed on pipeline external, pipe collar 1 circumferential direction inside direction has the optical-fibre channel of circle, described optical-fibre channel is used for placing distribution type fiber-optic 2, pipe collar 1 has three isometric openings, pipe collar 1 is divided into three sections by three openings, and each opening part is additionally provided with at least one rubber and connects sheet 5, and described rubber connects sheet 5 for connecting the two ends of an opening；

Being additionally provided with No. two openings on pipe collar 1, fixed structure 4 is arranged on the outside of described No. two openings, for fixing the two ends of No. two openings；

Package parts 3 are fixed at the two ends of each opening and No. two openings respectively, and described package parts 3 are for stationary distribution formula optical fiber。

Being wrapped in the optical-fibre channel within steel pipe collar 1 by distribution type fiber-optic 2, as it is shown in figure 1, pipe collar 1 is cut into three parts, the distance between any two parts is equal, namely forms the opening that three length is equal。Make the distribution type fiber-optic 2 in optical-fibre channel keep fully loosening, and reserve certain length at an opening and No. two opening parts。Package parts 3 adopt the metal derby of routine。By fixed structure 4, distribution type fiber-optic enhanced sensitivity device is fastened on pipeline external, then be positioned at the distribution type fiber-optic 2 of three opening parts then in tight state。For preventing the distribution type fiber-optic 2 of opening part to be pulled off in transport and installation process, each opening part is both provided with the rubber of two cross-sectional dimension 5mm and connects sheet 5 and be connected to the two ends of an opening。Pipe collar 1 is installed on pipeline outer wall, is regulated the width of opening by adjustment fixing structure 4, make the distribution type fiber-optic 2 of three opening parts have initial miniature deformation。When pipeline expands due to internal pressure change or shrinks, owing to the elastic modelling quantity of metal is much larger than the elastic modelling quantity of rubber and distribution type fiber-optic 2, then the deformation of whole pipeline can be approximately considered whole equivalent and is embodied on three sections of optical fiber, thus realizing the effect that pipe surface small strain is amplified。

Detailed description of the invention two: present embodiment is the further restriction to the distribution type fiber-optic enhanced sensitivity device described in embodiment one, in present embodiment, pipe collar 1 is divided into three sections that length is equal by three openings。

Three openings lay respectively on three trisection points of pipe collar 1 circumferencial direction, make distribution type fiber-optic 2 be divided into three parts that length is equal, it is therefore an objective to for convenience of calculation。

If the length of every section of distribution type fiber-optic 2 is L₁, sectional area A₁, elastic modulus E₁, suffered pulling force N₁；

The length of package parts 3 is L₂, sectional area A₂, elastic modulus E₂, suffered pulling force N₂；

Rubber connects leaf length L₃, sectional area A₃, elastic modulus E₃, suffered pulling force N₃；

Sheet 5 and distribution type fiber-optic 2 is connected for object of study, from the equilibrium condition of power with package parts 3, rubber:

N₂=N₁+N₃(1)

From mechanics of materials correlation formula:

$N_1=\frac{{\mathrm{\ΔL}}_1{E}_1{A}_1}{L_1}---\left(2\right)$

$N_3=\frac{{\mathrm{\ΔL}}_3{E}_3{A}_3}{L_3}---\left(3\right)$

That is:

$N_2=\frac{{\mathrm{\ΔL}}_1{E}_1{A}_1}{L_1}+\frac{{\mathrm{\ΔL}}_3{E}_3{A}_3}{L_3}---\left(4\right)$

Again because of E₁>>E₃, L₁≈L₃, △ L₁≈△L₃(5)

Therefore N₂≈N₁(6)

For avoiding confusion, below it is used that N represents N₁And N₂

Every section of optical-fiber deformation amount:

${\mathrm{\ΔL}}_1=\frac{{\mathrm{NL}}_1}{E_1{A}_1}---\left(7\right)$

The deformation quantity of each package parts 3:

${\mathrm{\ΔL}}_2=\frac{{\mathrm{NL}}_2}{E_2{A}_2}---\left(8\right)$

By known distribution type fiber-optic 2 strain of formula (1) (2) it is:

${\mathrm{\ϵ}}_1=\frac{N}{E_1{A}_1}---\left(9\right)$

The strain of package parts 3 is:

${\mathrm{\ϵ}}_2=\frac{N}{E_2{A}_2}---\left(10\right)$

Then:

Because E₂>>E_1,And A₂>>A_1,Therefore the strain of package parts 3 can be ignored_,Diameter is that the deformation of the pipeline of D can be approximately considered and is all embodied on three sections of distribution type fiber-optics 2:

3△L₁≈△L₀=D π ε₀(12)

${\mathrm{\ϵ}}_0=\frac{{\mathrm{\ΔL}}_0}{D\mathrm{\π}}\≈\frac{3{\mathrm{\ΔL}}_1}{D\mathrm{\π}}=\frac{3{\mathrm{\ϵ}}_{1}L}{D\mathrm{\π}}---\left(13\right)$

${\mathrm{\ϵ}}_1=\frac{D\mathrm{\π}}{3L_1}{\mathrm{\ϵ}}_0---\left(14\right)$

Theoretical enhanced sensitivity multiple is

For the aqueduct of DN2200, take L₁=0.5cm, then pipeline strain can amplify 4605 times。

Detailed description of the invention three: present embodiment is described in conjunction with Fig. 4, present embodiment is the further restriction to the distribution type fiber-optic enhanced sensitivity device described in embodiment one, in present embodiment, described fixed structure 4 includes a protruding 4-1, No. two protruding 4-2, top cover 4-3 and sheet metal, a number protruding 4-1 and No. two protruding 4-2 is separately fixed at the two ends of No. two openings, steel disc is between a protruding 4-1 and No. two protruding 4-2, and top cover 4-3 is fixed by screws in a protruding 4-1 and No. two protruding 4-2 tops。

In present embodiment, sheet metal can choose different-thickness according to practical situation, sheet metal is inserted between a protruding 4-1 and No. two protruding 4-2, the distribution type fiber-optic 2 making three opening parts produces initial microstrain, then with screw, top cover 4-3 is fixed on a protruding 4-1 and No. two protruding 4-2, thus plays the effect of stationary distribution formula photosensitivity enhancing device。

Detailed description of the invention four: present embodiment is described in conjunction with Fig. 5, present embodiment is the further restriction to the distribution type fiber-optic enhanced sensitivity device described in embodiment one, in present embodiment, described fixed structure 4 includes a protruding 4-1 and No. two protruding 4-2, a described protruding 4-1 and No. two protruding 4-2 is separately fixed at the two ends of No. two openings, the top of a number protruding 4-1 is provided with groove 4-4, the top of No. two protruding 4-2 is provided with slide block 4-5, described slide block 4-5 can move along No. two protruding 4-2 tops, and can enter inside groove 4-4, the end face of groove 4-4 end face and slide block 4-5 is provided with sawtooth。

Present embodiments provide for the another kind of concrete structure of fixed structure 4, as shown in Figure 5, slide block 4-5 is moved to the left, stop mobile after making it into groove 4-4 certain length, at this moment the distribution type fiber-optic 2 of three opening parts can produce initial microstrain, and fixation can be played in the position of slide block 4-5 by two gang saw teeth。Fixed structure 4 in present embodiment regulates the precision of initial microstrain and is better than embodiment two, and owing to eliminating the screw at top, so operationally more convenient。

Detailed description of the invention five: present embodiment is described in conjunction with Fig. 3; present embodiment is the further restriction to the distribution type fiber-optic enhanced sensitivity device described in embodiment one to four; in present embodiment, each opening part is additionally provided with screening glass 6, and described screening glass 6 is positioned at rubber and connects sheet 5 outside。

And using the screening glass 6 of steel to reinforce optical fiber further at an opening part, the two ends of an opening can arrange slot, inserts in slot by screening glass 6, covers rubber and connects sheet 5 and optical fiber, and screening glass 6 can reduce the impact on optical fiber of the buried rear surrounding soil。

Claims (5)

1. distribution type fiber-optic enhanced sensitivity device, it is characterized in that, this device includes metal pipe collar (1), distribution type fiber-optic (2), eight metal package parts (3), fixed structure (4) and multiple rubber and connects sheet (5)；

Described pipe collar (1) is in circular, for being fixed on pipeline external, pipe collar (1) circumferential direction inside direction has the optical-fibre channel of circle, described optical-fibre channel is used for placing distribution type fiber-optic (2), pipe collar (1) has three isometric openings, pipe collar (1) is divided into three sections by three openings, each opening part is additionally provided with at least one rubber and connects sheet (5), and described rubber connects sheet (5) for connecting the two ends of an opening；

Being additionally provided with No. two openings on pipe collar (1), fixed structure (4) is arranged on the outside of described No. two openings, for fixing the two ends of No. two openings；

A package parts (3) is fixed at the two ends of each opening and No. two openings respectively, and described package parts (3) are for stationary distribution formula optical fiber。

2. distribution type fiber-optic enhanced sensitivity device according to claim 1, it is characterised in that pipe collar (1) is divided into three sections that length is equal by three openings。

3. distribution type fiber-optic enhanced sensitivity device according to claim 1, it is characterized in that, described fixed structure (4) includes a projection (4-1), No. two projections (4-2), top cover (4-3) and sheet metal, a number projection (4-1) and No. two projections (4-2) are separately fixed at the two ends of No. two openings, steel disc is positioned between a projection (4-1) and No. two projections (4-2), and top cover (4-3) is fixed by screws in a projection (4-1) and No. two projection (4-2) tops。

4. distribution type fiber-optic enhanced sensitivity device according to claim 1, it is characterized in that, described fixed structure (4) includes a projection (4-1) and No. two projections (4-2), a described projection (4-1) and No. two projections (4-2) are separately fixed at the two ends of No. two openings, the top of a number projection (4-1) is provided with groove (4-4), the top of No. two projections (4-2) is provided with slide block (4-5), described slide block (4-5) can move along No. two projection (4-2) tops, and it is internal to enter groove (4-4), the end face of groove (4-4) end face and slide block (4-5) is provided with sawtooth。

5. the distribution type fiber-optic enhanced sensitivity device according to claim 1,2,3 or 4, it is characterised in that each opening part is additionally provided with screening glass (6), and described screening glass (6) is positioned at rubber and connects sheet (5) outside。