Search

CN-121994384-A - Thin-wall cylinder pressure sensor based on distributed optical fiber strain measurement

CN121994384ACN 121994384 ACN121994384 ACN 121994384ACN-121994384-A

Abstract

A thin-wall cylinder pressure sensor based on distributed optical fiber strain measurement is characterized in that one end of a sensing sleeve is a closed end, the middle of the sensing sleeve is a thin-wall sensing section, the other end of the sensing sleeve is a connecting end, a connecting joint is connected to the connecting end of the sensing sleeve, an axial through hole is machined in the center of the connecting joint and is communicated with a cavity of the sensing sleeve, and a single-mode fiber is wound on the thin-wall sensing section of the sensing sleeve. According to the invention, the optical fiber is combined with the thin-wall cylinder structure, the whole area of the outer wall of the sensing sleeve is subjected to continuous strain monitoring, the complete information of the strain distribution of the whole cylinder wall is obtained, the limitation of point type measurement of the traditional sensor is broken through, the limited omission of key pressure change areas due to measurement points is avoided, the pressure field distribution data can be synchronously obtained, and a brand new technical path is provided for accurate analysis and fault pre-judgment under a complex pressure environment.

Inventors

  • SU DAN
  • XIA YUFEI
  • HU XIXI
  • QIAO XUEGUANG

Assignees

  • 西北大学

Dates

Publication Date
20260508
Application Date
20260310

Claims (7)

  1. 1. A thin-wall cylinder pressure sensor based on distributed optical fiber strain measurement is characterized in that one end of a sensing sleeve is a closed end, the middle of the sensing sleeve is a thin-wall sensing section, the other end of the sensing sleeve is a connecting end, a connecting joint is connected to the connecting end of the sensing sleeve, an axial through hole is machined in the center of the connecting joint and is communicated with a cavity of the sensing sleeve, and a single-mode fiber is wound on the thin-wall sensing section of the sensing sleeve.
  2. 2. The thin-walled cylinder pressure sensor based on distributed optical fiber strain measurement according to claim 1, wherein the ratio of the inner diameter to the wall thickness of the thin-walled sensing section of the sensing sleeve is more than or equal to 20.
  3. 3. The thin-walled cylinder pressure sensor based on distributed optical fiber strain measurement according to claim 2, wherein the thin-walled sensing section of the sensing sleeve has a wall thickness of 0.5-2 mm.
  4. 4. The thin-walled cylinder pressure sensor based on distributed optical fiber strain measurement of claim 1 wherein the single mode fiber is a bend insensitive single mode fiber.
  5. 5. The thin-walled cylinder pressure sensor based on distributed optical fiber strain measurement of claim 1 wherein the sensing sleeve is one of stainless steel, copper and titanium.
  6. 6. The thin-walled cylinder pressure sensor based on distributed optical fiber strain measurement as set forth in claim 1, wherein a sealing ring is disposed between the connection joint and the connection end of the sensing sleeve.
  7. 7. A method for calibrating a thin-wall cylindrical fiber grating pressure sensor is characterized in that the pressure sensor in claim 1 is subjected to strain measurement, the applied pressure ranges from 1 MPa to 20 MPa, the pressure is stabilized for 120 seconds every 2 MPa seconds, the pressure is repeated at least three times, a strain distribution curve of an optical fiber section wound on a thin-wall sensing section of the pressure sensor in claim 1 is obtained, a maximum strain area on the thin-wall sensing section in claim 1 is marked based on the strain distribution curve, a single-mode fiber of the pressure sensor in claim 1 is removed, an optical fiber with an optical grating is pasted on a sensing sleeve, the optical grating section is positioned in the maximum strain area, and the calibration of the thin-wall cylindrical fiber grating pressure sensor is completed.

Description

Thin-wall cylinder pressure sensor based on distributed optical fiber strain measurement Technical Field The invention belongs to the technical field of sensors, and particularly relates to a thin-wall cylinder pressure sensor based on distributed optical fiber strain measurement. Background The pressure measurement is used as an indispensable basic detection link in industrial production, scientific research and exploration and engineering practice, and the accuracy of industrial system state evaluation, the reliability of engineering decision and the effectiveness of scientific research experimental data are directly determined by the measurement precision, the space coverage capability, the environmental adaptability and the dynamic response speed. In recent years, with the rapid development of the fields of aerospace, energy chemical industry, civil engineering, deep sea exploration, high-end equipment manufacturing and the like, the demands for pressure monitoring show a diversified upgrading trend of global continuous monitoring, complex environment adaptation, rapid dynamic response and high-precision micro-change detection, the technical short plates of the traditional pressure sensors are increasingly prominent, and the high-end measurement demands of various fields are difficult to meet. The traditional pressure sensor mainly comprises an electric sensor, wherein the electric sensor comprises piezoelectric type, piezoresistive type, capacitive type and the like, the sensor can only realize point measurement, cannot continuously monitor a pressure field in a large range, is easy to miss a key pressure change area, is difficult to completely reflect pressure field distribution, is easy to be subjected to electromagnetic interference, greatly reduces measurement accuracy in a strong electromagnetic environment and even fails, is relatively complex in structural design, has low dynamic response speed, cannot capture a pressure signal with quick transient, is difficult to adapt to the monitoring requirement of the pressure field with quick change, has poor corrosion resistance and high pressure resistance, and has poor stability and short service life in severe environments such as chemical high temperature and high pressure, deep sea high salt and the like. In order to break through the technical bottleneck of the traditional electric sensor, the optical fiber pressure sensor has the unique advantages of electromagnetic interference resistance, corrosion resistance, small volume, light weight and continuous arrangement, becomes an important direction of the development of the pressure measurement technology, and provides a brand new technical path for monitoring the distributed pressure field. The distributed optical fiber sensor based on the technologies of optical frequency domain reflection, optical back scattering and the like can acquire strain distribution information along a long-distance optical fiber with millimeter-level spatial resolution, realize global continuous monitoring of physical quantity, meet the main requirements of each field on pressure field distribution detection, and become research hot spots in the current optical fiber sensing field. However, the existing optical fiber pressure sensor still has a plurality of problems to be optimized in structural design, measurement coupling mechanism and practical application suitability, the existing optical fiber pressure sensor adopts single-point or local sensing modes, global strain distribution monitoring cannot be achieved, the optical fiber Fabry-Perot type interference pressure sensor is complex in structural design and is easy to erode by media and interfere with temperature in a pressure medium environment, when the optical fiber grating type sensor is combined with a thin-wall cylindrical structure, the optical fiber arrangement mode is lack of pertinence, a grating pasting link has no definite positioning basis, a cylindrical maximum strain area is not determined first, and therefore grating pasting is difficult to collimate, maximum strain cannot be captured accurately, and optimal measurement performance cannot be achieved. Disclosure of Invention The invention aims to overcome the defects of the prior art and provide the thin-walled cylinder pressure sensor based on distributed optical fiber strain measurement, which has the advantages of compact structure, small volume, global continuous strain monitoring and more accurate pressure field analysis. The technical scheme for solving the technical problems is that the thin-wall cylinder pressure sensor based on distributed optical fiber strain measurement is characterized in that one end of a sensing sleeve is a closed end, the middle of the sensing sleeve is a thin-wall sensing section, the other end of the sensing sleeve is a connecting end, a connecting joint is connected to the connecting end of the sensing sleeve, an axial through hole is machined in the center of the c