CN113030242A - Subway buried metal pipeline corrosion optical fiber monitoring device and method - Google Patents
Subway buried metal pipeline corrosion optical fiber monitoring device and method Download PDFInfo
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- CN113030242A CN113030242A CN202110243852.3A CN202110243852A CN113030242A CN 113030242 A CN113030242 A CN 113030242A CN 202110243852 A CN202110243852 A CN 202110243852A CN 113030242 A CN113030242 A CN 113030242A
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Abstract
The patent relates to a subway buried metal pipeline corrosion optical fiber monitoring device and a method, wherein the monitoring device comprises an excitation unit, a sensing unit, a pre-tightening unit, a supporting unit and a control unit, and provides a subway metal pipeline corrosion monitoring method, which specifically comprises the following steps: the exciting unit outputs exciting current to the other end of the buried metal pipeline along one end of the buried metal pipeline, a magnetic field generated by excitation of the exciting current is conducted to the pre-tightened magnetostrictive composite material along a magnetizer of the sensing unit, the magnetostrictive composite material deforms accordingly and causes the optical fiber grating adhered to the magnetostrictive composite material to deform in proportion, the optical fiber grating transmits a deformation signal to the control unit, circulating current on the metal pipeline at the arrangement position of the sensing unit is obtained after calculation of the control unit, and when the exciting current values monitored by two adjacent sensing units are different and the difference value exceeds a set threshold value, the control unit considers that the metal pipeline between the two sensing units is corroded and gives an alarm.
Description
Technical Field
The invention relates to corrosion monitoring of underground metal pipelines, in particular to a corrosion optical fiber monitoring device and method for underground metal pipelines.
Background
At present, a subway power supply system mostly adopts a direct current traction power supply mode, a subway locomotive obtains traction current from a traction substation through a contact network, the traction current returns to the traction substation along a running rail, the insulation performance between the running rail and a track bed of the subway is gradually reduced along with the increase of the operation time of the subway, and part of the traction current leaks to peripheral media from the running rail to form stray current. Stray current can not only cause electrochemical corrosion to a main steel bar structure of a subway system, but also cause corrosion damage to underground buried metal pipelines and the like, the service life and the durability of the buried metal pipelines are reduced, catastrophic consequences can be caused under severe conditions, the buried metal pipelines are usually in underground depths and are in moist corrosive environments all the year round, and the online reliable and accurate method for monitoring the corrosion of the buried metal pipelines is rarely used at present.
Disclosure of Invention
The purpose of the invention is as follows: aiming at the problems, the invention provides an underground subway metal pipeline corrosion optical fiber monitoring device and method, wherein the device is convenient to install and disassemble, simple in detection principle and easy to operate.
The technical scheme is as follows: in order to realize the purpose of the invention, the technical scheme adopted by the invention is as follows: an optical fiber monitoring device for corrosion of a subway buried metal pipeline comprises an excitation unit (1), a supporting unit (2), a sensing unit (3), a pre-tightening unit (4) and a control unit (5);
the supporting unit (2) comprises a supporting fastener (21) and magnetizer slots (22), the supporting fastener (21) is a first semicircular arc steel structure (211) and a second semicircular arc steel structure (212) which are symmetrical, two ends of the first semicircular arc steel structure (211) and two ends of the second semicircular arc steel structure (212) are respectively connected through a first bolt (213) and a second bolt (214) to form a steel ring, and the two magnetizer slots (22) are symmetrically arranged on the outer sides of the semicircular arc steel structures (211) and (212);
the sensing unit (3) is composed of 2 permanent magnets (31), magnetostrictive composite materials (32), magnetizers (33) and fiber gratings (34), wherein the number of the permanent magnets (31) is 2, the permanent magnets are respectively a first permanent magnet (311) and a second permanent magnet (312), and a constant bias magnetic field is provided for the magnetostrictive composite materials (32); the magnetizer (33) comprises a first 3/8 arc-shaped steel structure (331) and a second 3/8 arc-shaped steel structure (332) which are symmetrical; the first 3/8 arc-shaped steel structure (331) and the second 3/8 arc-shaped steel structure (332) respectively penetrate through the two magnetizer slots (22); the first permanent magnet (311) and the second permanent magnet (312) are respectively connected with one ends of a first 3/8 arc-shaped steel structure (331) and a second 3/8 arc-shaped steel structure (332); two ends of the magnetostrictive composite material (32) are respectively connected with the other ends of the first 3/8 arc-shaped steel structure (321) and the second 3/8 arc-shaped steel structure (322);
one end of the fiber grating (34) is embedded in the magnetostrictive composite material (32), and the other end is connected with the control unit (5);
the pre-tightening unit (4) comprises a shell (41), an inner sliding groove (42), a sliding block (43), a spring (44) and a pre-tightening bolt (45), wherein the shell (41) is welded on the outer side of the supporting fastener (21), and the inner sliding groove (42) is formed in the shell; the sliding block (43) is matched with the inner sliding groove (42), an inner thread is arranged at the upper end of the sliding block (43), one side of the spring (44) is connected with the inner thread in a matched mode, the other side of the spring is matched with the permanent magnet (31), and the pre-tightening bolt (45) is installed at the bottom of the shell (41) through a threaded hole;
the excitation unit (1) is connected with one end of the metal pipeline (6), and the excitation unit (1) outputs excitation current to the other end along one end of the metal pipeline (6); the supporting units (2) are fixed on the metal pipeline (6) through the steel ring and are arranged at equal intervals;
the sensing unit (3) monitors the excitation current flowing through the arrangement position of the sensing unit; the permanent magnet (31) of the sensing unit (3) is connected with the spring (44) of the pre-tightening unit (4), and the pre-tightening bolt (45) is rotated to push the sliding block (43) to compress the spring (44) along the inner sliding groove (42) to generate pre-tightening force, so that the first permanent magnet (311) and the second permanent magnet (312) are respectively pressed on the spring (44) of the pre-tightening unit (4) connected with the first permanent magnet and the second permanent magnet; the pretightening force sequentially acts on the magnetostrictive composite material (32) connected with the magnetizer (33) through the permanent magnet (31) connected with the spring (44) and the magnetizer (33) connected with the permanent magnet (31), so that the measurement sensitivity of the magnetostrictive composite material (32) is improved; and the control unit (5) receives the return signal of the sensing unit (3) and performs calculation, storage and alarm.
The invention also provides a subway buried metal pipeline corrosion optical fiber monitoring method realized according to the subway buried metal pipeline corrosion optical fiber monitoring device, which comprises the following steps:
S1: the excitation unit (1) outputs excitation current to the other end along one end of the metal pipeline (6), and the excitation current forms an annular magnetic field along the metal pipeline (6);
S2: the magnetizer (33) of the sensing unit (3) converges the magnetic field of the metal pipeline at the arrangement position and transmits the converged magnetic field to the magnetostrictive composite material (32), the magnetostrictive composite material (32) generates strain under the action of the magnetic field, the strain generated by the magnetostrictive composite material (32) causes the central wavelength of the optical fiber grating (34) embedded in the magnetostrictive composite material to change in proportion, and the control unit (5) converts the excitation current of the metal pipeline (6) at the position according to the signal characteristics returned by the optical fiber grating (34);
S3: the control unit (5) stores the monitoring results of the sensing units (3) at different positions in sequence, and when the difference value of the monitoring results of two adjacent sensing units (3) is not more than 10mA, the control unit (5) judges that the metal pipeline between the two sensing units (3) is not corroded; when the difference value of the monitoring results of two adjacent sensing units (3) is larger than 10mA, the control unit (5) judges that the metal pipeline between the two sensing units (3) is corroded and gives an alarm.
Has the advantages that: compared with the prior art, the technical scheme of the invention has the following beneficial technical effects:
the underground metal pipeline corrosion monitoring device can realize high-precision monitoring of underground metal pipeline corrosion, is low in cost, can be assembled and disassembled on site, and is convenient to use.
Drawings
FIG. 1 is a fiber optic monitoring device;
FIG. 2 is a supporting unit;
FIG. 3 is a sensing unit;
FIG. 4 is a pretensioning unit;
in the figure: 1. the device comprises an excitation unit, 2, a support unit, 3, a sensing unit, 4, a pre-tightening unit, 5, a control unit, 21, a support fastener, 22, a magnetizer slot, 211, a first semi-circular arc steel structure, 212, a second semi-circular arc steel structure, 213, a first bolt, 214, a second bolt, 31, a permanent magnet, 32, a magnetostrictive composite material, 33, a magnetizer, 34, a fiber grating, 311, a first permanent magnet, 312, a second permanent magnet, 331, a first 3/8 circular arc steel structure, 332, a second 3/8 circular arc steel structure, 41, a shell, 42, an inner chute, 43, a sliding block, 44, a spring, 45 and a pre-tightening bolt.
Detailed Description
The following further describes embodiments of the present patent with reference to the drawings.
The invention provides a subway buried metal pipeline corrosion optical fiber monitoring device which comprises an excitation unit (1), a supporting unit (2), a sensing unit (3), a pre-tightening unit (4) and a control unit (5);
the supporting unit (2) comprises a supporting fastener (21) and magnetizer slots (22), the supporting fastener (21) is a first semicircular arc steel structure (211) and a second semicircular arc steel structure (212) which are symmetrical, two ends of the first semicircular arc steel structure (211) and two ends of the second semicircular arc steel structure (212) are respectively connected through a first bolt (213) and a second bolt (214) to form a steel ring, and the two magnetizer slots (22) are symmetrically arranged on the outer sides of the semicircular arc steel structures (211) and (212);
the sensing unit (3) is composed of 2 permanent magnets (31), magnetostrictive composite materials (32), magnetizers (33) and fiber gratings (34), wherein the number of the permanent magnets (31) is 2, the permanent magnets are respectively a first permanent magnet (311) and a second permanent magnet (312), and a constant bias magnetic field is provided for the magnetostrictive composite materials (32); the magnetizer (33) comprises a first 3/8 arc-shaped steel structure (331) and a second 3/8 arc-shaped steel structure (332) which are symmetrical; the first 3/8 arc-shaped steel structure (331) and the second 3/8 arc-shaped steel structure (332) respectively penetrate through the two magnetizer slots (22); the first permanent magnet (311) and the second permanent magnet (312) are respectively connected with one ends of a first 3/8 arc-shaped steel structure (331) and a second 3/8 arc-shaped steel structure (332); two ends of the magnetostrictive composite material (32) are respectively connected with the other ends of the first 3/8 arc-shaped steel structure (321) and the second 3/8 arc-shaped steel structure (322);
one end of the fiber grating (34) is embedded in the magnetostrictive composite material (32), and the other end is connected with the control unit (5);
the pre-tightening unit (4) comprises a shell (41), an inner sliding groove (42), a sliding block (43), a spring (44) and a pre-tightening bolt (45), wherein the shell (41) is welded on the outer side of the supporting fastener (21), and the inner sliding groove (42) is formed in the shell; the sliding block (43) is matched with the inner sliding groove (42), an inner thread is arranged at the upper end of the sliding block (43), one side of the spring (44) is connected with the inner thread in a matched mode, the other side of the spring is matched with the permanent magnet (31), and the pre-tightening bolt (45) is installed at the bottom of the shell (41) through a threaded hole;
the excitation unit (1) is connected with one end of the metal pipeline (6), and the excitation unit (1) outputs excitation current to the other end along one end of the metal pipeline (6); the supporting units (2) are fixed on the metal pipeline (6) through the steel ring and are arranged at equal intervals;
the sensing unit (3) monitors the excitation current flowing through the arrangement position of the sensing unit; the pre-tightening bolt (45) is rotated to push the sliding block (43) to compress the spring (44) along the inner chute (42) to generate pre-tightening force, so that the first permanent magnet (311) and the second permanent magnet (312) are respectively pressed on the spring (44) of the pre-tightening unit (4) connected with the first permanent magnet and the second permanent magnet; the pretightening force sequentially acts on the magnetostrictive composite material (32) connected with the magnetizer (33) through the permanent magnet (31) connected with the spring (44) and the magnetizer (33) connected with the permanent magnet (31), so that the measurement sensitivity of the magnetostrictive composite material (32) is improved; and the control unit (5) receives the return signal of the sensing unit (3) and performs calculation, storage and alarm.
The invention also provides a subway buried metal pipeline corrosion optical fiber monitoring method realized according to the subway buried metal pipeline corrosion optical fiber monitoring device, which comprises the following steps:
S1: the excitation unit (1) outputs excitation current to the other end along one end of the metal pipeline (6), and the excitation current forms an annular magnetic field along the metal pipeline (6);
S2: magnetizer (3) of sensing unit33) The magnetic field of the metal pipeline at the distribution position is converged and then transmitted to the magnetostrictive composite material (32), the magnetostrictive composite material (32) generates strain under the action of the magnetic field, the strain generated by the magnetostrictive composite material (32) causes the central wavelength of the optical fiber grating (34) embedded in the magnetostrictive composite material to change in proportion, and the control unit (5) converts the excitation current of the metal pipeline (6) according to the signal characteristics returned by the optical fiber grating (34);
S3: the control unit (5) stores the monitoring results of the sensing units (3) at different positions in sequence, and when the difference value of the monitoring results of two adjacent sensing units (3) is not more than 10mA, the control unit (5) judges that the metal pipeline between the two sensing units (3) is not corroded; when the difference value of the monitoring results of two adjacent sensing units (3) is larger than 10mA, the control unit (5) judges that the metal pipeline between the two sensing units (3) is corroded and gives an alarm.
The magnetostrictive composite material (32) is prepared by uniformly mixing Terfenol-D powder, epoxy resin, a curing agent and a coupling agent in proportion, wherein the proportion of the Terfenol-D powder to the epoxy resin is 5:1, the proportion of the epoxy resin to the curing agent is 3:1, and the coupling agent accounts for 2% of the whole mixture. The epoxy resin serves to bond the Terfenol-D powder particles, and the coupling agent serves to enhance the bonding force of the Terfenol-D powder particles to the epoxy resin. The Terfenol-D powder treated by the coupling agent adopts an integral mixing method, and the specific surface treatment method is simple and easy to operate.
Claims (2)
1. The optical fiber monitoring device for corrosion of the underground subway metal pipeline is characterized by comprising an excitation unit (1), a supporting unit (2), a sensing unit (3), a pre-tightening unit (4) and a control unit (5);
the supporting unit (2) comprises a supporting fastener (21) and magnetizer slots (22), the supporting fastener (21) is a first semicircular arc steel structure (211) and a second semicircular arc steel structure (212) which are symmetrical, two ends of the first semicircular arc steel structure (211) and two ends of the second semicircular arc steel structure (212) are respectively connected through a first bolt (213) and a second bolt (214) to form a steel ring, and the two magnetizer slots (22) are symmetrically arranged on the outer sides of the semicircular arc steel structures (211) and (212);
the pre-tightening unit (4) comprises a shell (41), an inner sliding groove (42), a sliding block (43), a spring (44) and a pre-tightening bolt (45), wherein the shell (41) is welded on the outer side of the supporting fastener (21), and the inner sliding groove (42) is formed in the shell; the sliding block (43) is matched with the inner sliding groove (42), an internal thread is arranged at the upper end of the sliding block (43), one side of the spring (44) is matched and connected with the internal thread, and the pre-tightening bolt (45) is installed at the bottom of the shell (41) through a threaded hole;
the sensing unit (3) is composed of 2 permanent magnets (31), magnetostrictive composite materials (32), magnetizers (33) and fiber gratings (34), wherein the number of the permanent magnets (31) is 2, the permanent magnets are respectively a first permanent magnet (311) and a second permanent magnet (312), and a constant bias magnetic field is provided for the magnetostrictive composite materials (32); the magnetizer (33) comprises a first 3/8 arc-shaped steel structure (331) and a second 3/8 arc-shaped steel structure (332) which are symmetrical; the first 3/8 arc-shaped steel structure (331) and the second 3/8 arc-shaped steel structure (332) respectively penetrate through the two magnetizer slots (22); the first permanent magnet (311) and the second permanent magnet (312) are respectively connected with one ends of a first 3/8 arc-shaped steel structure (331) and a second 3/8 arc-shaped steel structure (332); two ends of the magnetostrictive composite material (32) are respectively connected with the other ends of the first 3/8 arc-shaped steel structure (321) and the second 3/8 arc-shaped steel structure (322); one end of the fiber grating (34) is embedded in the magnetostrictive composite material (32), and the other end is connected with the control unit (5);
the first permanent magnet (311) is connected with one pre-tightening unit (4) through a spring (44), and the second permanent magnet (312) is connected with the other pre-tightening unit (4) through the spring (44);
the excitation unit (1) is connected with one end of the metal pipeline (6), and the excitation unit (1) outputs excitation current to the other end along one end of the metal pipeline (6); the supporting units (2) are fixed on the metal pipeline (6) through the steel ring and are arranged at equal intervals;
the pre-tightening bolt (45) is rotated to push the sliding block (43) to compress the spring (44) along the inner chute (42) to generate pre-tightening force, so that the first permanent magnet (311) and the second permanent magnet (312) are respectively pressed on the spring (44) of the pre-tightening unit (4) connected with the first permanent magnet and the second permanent magnet; the pretightening force sequentially acts on the magnetostrictive composite material (32) connected with the magnetizer (33) through the permanent magnet (31) connected with the spring (44) and the magnetizer (33) connected with the permanent magnet (31), so that the measurement sensitivity of the magnetostrictive composite material (32) is improved; and the control unit (5) receives the return signal of the sensing unit (3) and performs calculation, storage and alarm.
2. The underground metal pipeline corrosion optical fiber monitoring method is realized according to the underground metal pipeline corrosion optical fiber monitoring device, and is characterized by comprising the following steps of:
S1: the excitation unit (1) outputs excitation current to the other end along one end of the metal pipeline (6), and the excitation current forms an annular magnetic field along the metal pipeline (6);
S2: the magnetizer (33) of the sensing unit (3) converges the magnetic field of the metal pipeline at the arrangement position and transmits the converged magnetic field to the magnetostrictive composite material (32), the magnetostrictive composite material (32) generates strain under the action of the magnetic field, the strain generated by the magnetostrictive composite material (32) causes the central wavelength of the optical fiber grating (34) embedded in the magnetostrictive composite material to change in proportion, and the control unit (5) converts the excitation current of the metal pipeline (6) at the position according to the signal characteristics returned by the optical fiber grating (34);
S3: the control unit (5) stores the monitoring results of the sensing units (3) at different positions in sequence, and when the difference value of the monitoring results of two adjacent sensing units (3) is not more than 10mA, the control unit (5) judges that the metal pipeline between the two sensing units (3) is not corroded; when the difference value of the monitoring results of two adjacent sensing units (3) is larger than 10mA, the control unit (5) judges that the metal pipeline between the two sensing units (3) is corroded and gives an alarm.
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| CN202110243852.3A CN113030242A (en) | 2021-03-05 | 2021-03-05 | Subway buried metal pipeline corrosion optical fiber monitoring device and method |
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| CN202110243852.3A CN113030242A (en) | 2021-03-05 | 2021-03-05 | Subway buried metal pipeline corrosion optical fiber monitoring device and method |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
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| WO2024082775A1 (en) * | 2022-10-20 | 2024-04-25 | 中国矿业大学 | Optical fiber current sensor system for underground spaces such as coal mines and the like and method |
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