CN200958686Y

CN200958686Y - Quasi-distributed optic-fiber oil-leakage sensor system

Info

Publication number: CN200958686Y
Application number: CN 200620044118
Authority: CN
Inventors: 张晓建; 阮昊
Original assignee: Shanghai Institute of Optics and Fine Mechanics of CAS
Current assignee: Shanghai Institute of Optics and Fine Mechanics of CAS
Priority date: 2006-07-21
Filing date: 2006-07-21
Publication date: 2007-10-10
Anticipated expiration: 2016-07-21

Abstract

A quasi-distributed fiber-optical oil-leakage sensor system to monitor the leakage in oil pipelines is provided, comprising an optical fiber which has one end connected to an optical time domain reflectometer, and one or several fiber-optical leakage sensors whose fiber-optical rings are connected in series by the optical fiber, the fiber-optical leakage sensor comprising a shell which encapsulates a fiber-optical ring and a piece of EPDM rubber, the end of the shell where the EPDM rubber is fixed having a plurality of small holes. The utility model is easy to install with a short debugging time, and can monitor multiple points synchronously.

Description

Quasi-distributing optical fiber oil leakage sensor system

Technical field

The utility model relates to Fibre Optical Sensor and engineering leakage safety precaution equipment, particularly a kind of quasi-distributing optical fiber oil leakage sensor system that is used to monitor the petroleum pipeline leakage.

Background technique

Utilize the line transportation fluid to be a kind of convenient economic means of transprotation, current in petroleum industry, utilize the line transportation oil to have a wide range of applications.Along with the development of line transportation engineering, the economic loss that the leakage failure of pipeline causes more and more causes people's attention.Therefore, people are constantly developed the monitoring method of various pipe leakages, mainly contain two class line leakage methods now: indirect monitoring and directly monitoring.Wherein most of long-distance pipe mainly uses present stage is the indirect monitoring method, as negative pressure wave method, gradient pressure method etc., exactly by the flow of pipeline output terminal and input end, the detection of pressure and other parameters are judged whether pipeline leakage accident takes place.Yet because the loss that suction wave is propagated is big, the sensitivity of pressure transducer and flowmeter itself is limited, the indirect monitoring method only is applicable to a large amount of situations of leaking such as pipeline breaking, for stealing small leakage situations such as oil, pipe leakage, this method exists the location resolving power not high, deficiencys such as rate of false alarm height.Compare with the indirect monitoring method, directly monitoring method can well detect the situation of leakage of oil in a small amount, the quasi-distributed oil leakage sensor system of many documents and company proposition based on fiber bragg grating arranged at present, and this sensed system can be realized many reference amounts, the quasi-distributed measurement of multiple spot.But, there is mutual interference mutually between the temperature of fiber-optic grating sensor and pressure signal, to effectively suppress the strict encapsulation technology of this interference needs, and each fiber bragg grating all needs strict the determining and debugging of centre wavelength that carry out before and after installing, and increased the difficulty and the cost of actual project installation.

Summary of the invention

The purpose of this utility model is to overcome the deficiency of above-mentioned technology formerly, and a kind of quasi-distributing optical fiber oil leakage sensor system is provided, and this system should have easy installation, field adjustable time weak point, can realize the multiple spot monitoring.

Technical solution of the present utility model is as follows:

A kind of quasi-distributing optical fiber oil leakage sensor system, it is characterized in that it is connected with an optical time domain reflectometer by an end optical fiber is in series the fibre optic ring of one or more optical fiber oil leakage sensors, the formation of described optical fiber oil leakage sensor is encapsulation one fibre optic ring and a block rubber in a shell, on the shell of fixing that end of block rubber a plurality of apertures is arranged.Described block rubber is an ethylene-propylene-diene monomer blob of viscose piece.

Principle of the present utility model is the characteristic according to bending loss of optical fiber, be fiber bending radius during greater than the critical bends radius bend loss can ignore, fiber bending radius during less than the critical bends radius bend loss increase rapidly, and ethylene propylene diene rubber has the characteristics of good swellability to the petroleum-type solvent.

Technique effect of the present utility model is as follows:

1, can realize multiple spot monitoring and locating function, promptly judge these pipe leakage incidents of orienting.

2, the utlity model has easy for installation, field adjustable time weak point, cost is low, can realize characteristics such as multi-point sensing monitoring.

Description of drawings

Below in conjunction with accompanying drawing the utility model is further specified.

Fig. 1 is the structural representation of the utility model optical fiber oil leakage sensor.

Fig. 2 is the structural representation of the utility model quasi-distributing optical fiber oil leakage sensor system.

Fig. 3 is the plotted curve that the detected back of optical time domain reflectometer changes with fiber lengths to the Rayleigh scattering luminous power.

Embodiment

The utility model is described in further detail below in conjunction with accompanying drawing.

See also Fig. 1 and Fig. 2 earlier, Fig. 1 is the structural representation of the utility model optical fiber oil leakage sensor, and Fig. 2 is the structural representation of the utility model quasi-distributing optical fiber oil leakage sensor system.As seen from the figure, the utility model quasi-distributing optical fiber oil leakage sensor system, the optical fiber 1 that is connected with an optical time domain reflectometer 6 by an end constitutes one or more optical fiber oil leakage sensor 8 series connection, the formation of described optical fiber oil leakage sensor 8 is encapsulation one fibre optic ring 5 and ethylene-propylene-diene monomer blob of viscoses 3 in a shell 2, and a plurality of apertures 4 are arranged on the shell 2 of that end of fixing this ethylene-propylene-diene monomer blob of viscose 3.

The bending radius of the fibre optic ring 5 in the optical fiber oil leakage sensor is set to equal or is slightly larger than optical fiber critical bends radius, fibre optic ring 5 and an ethylene-propylene-diene monomer blob of viscose 3 are encapsulated in the package casing 2 as shown in Figure 1, on that end package casing 2 of fixing block rubber 3 a series of apertures 4 are arranged.When petroleum pipeline generation seepage, oil enters aperture 4 and contacts with ethylene-propylene-diene monomer blob of viscose 3, and ethylene propylene diene rubber is met oil and produced expansion, and fibre optic ring 5 is applied an active force.Fibre optic ring 5 stressed back local buckling radiuses diminish, when the bending radius of fibre optic ring 5 during less than the critical bends radius, bending loss of optical fiber increases rapidly, positions by optical time domain reflectometer 6 online detection light loss consumptions and to loss increase point, can judge and the targeted duct leakage.

When oil pipe detection zone 9 did not have incident of leakage to take place, the curve that optical time domain reflectometer 6 detected backs change with fiber lengths to the Rayleigh scattering luminous power was shown in Fig. 3 curve a, and curve smoothing is fluctuation not, and the expression fibre loss does not change.When incident of leakage takes place in oil pipe detection zone 9, the curve that the detected back of optical time domain reflectometer 6 changes with fiber lengths to the Rayleigh scattering luminous power is shown in Fig. 3 curve b, stair-stepping decline appears in curve, and expression optical fiber excess loss occurs in the place that curve descends.The situation that Fig. 3 curve b occurs is, the optical fiber connecting end be respectively distance 1 and distance 2 optical fiber on excess loss has appearred, show that the optical fiber oil leakage sensor that is installed in this two place detects the generation of leakage of oil incident at corresponding oil pipe monitoring section.Can see that the utility model can detect a lot of leakage of oil incidents of pipeline simultaneously, and the place of locating events generation simultaneously.

Claims

1, a kind of quasi-distributing optical fiber oil leakage sensor system, it is characterized in that it is connected with an optical time domain reflectometer (6) by an end optical fiber (1) is with one or more optical fiber oil leakage sensors (8) series connection and constitute, the formation of described optical fiber oil leakage sensor (8) is encapsulation one fibre optic ring (5) and an ethylene-propylene-diene monomer blob of viscose (3) in a shell (2), on the shell (2) of that end of fixing this ethylene-propylene-diene monomer blob of viscose (3) a plurality of apertures (4) is arranged.