阅读说明：本技术 一种基于游标效应的压力传感探头和压力传感器 (Pressure sensing probe and pressure sensor based on vernier effect ) 是由 徐刚 李红丽 李子睿 袁静 王俣晗 李玉梅 于 2020-06-24 设计创作，主要内容包括：本发明公开一种基于游标效应的压力传感探头和压力传感器,该压力传感探头包括底座、耦合器、光谱仪、激光器、两根单模光纤、两个毛细玻璃管、两个感压膜片和两个反光膜片,底座的一侧间隔设有两个凹槽,两个凹槽的槽底上分别安装有反光膜片,两个感压膜片分别安装在两个凹槽内,且每个凹槽内的感压膜片与反光膜片之间具有间隙并构成密闭的FP腔室,两个FP腔室内填充有两种弹性性能相异的透明材料,两个毛细玻璃管与凹槽贯通,两根单模光纤固定安装在两根毛细玻璃管内,其端面分别与反光膜片接触,两根单模光纤的另一端通过耦合器与光谱仪和激光器连接。本发明利用游标效应提高了本申请所述压力传感探头和压力传感器的灵敏度。(The invention discloses a pressure sensing probe and a pressure sensor based on vernier effect, the pressure sensing probe comprises a base, a coupler, a spectrometer, a laser, two single mode fibers, two capillary glass tubes, two pressure sensing membranes and two reflecting membranes, wherein two grooves are arranged at intervals on one side of the base, the reflecting membranes are respectively arranged on the bottoms of the two grooves, the two pressure sensing membranes are respectively arranged in the two grooves, and a gap is arranged between the pressure sensing diaphragm and the light reflecting diaphragm in each groove to form a closed FP chamber, two FP chambers are filled with two transparent materials with different elastic properties, two capillary glass tubes are communicated with the grooves, two single-mode optical fibers are fixedly arranged in the two capillary glass tubes, the end faces of the two single-mode optical fibers are respectively contacted with the reflective membrane, and the other ends of the two single-mode optical fibers are connected with the spectrometer and the laser through the coupler. The invention utilizes vernier effect to improve the sensitivity of the pressure sensing probe and the pressure sensor.)

1. The pressure sensing probe based on the vernier effect is characterized by comprising a base (1), a coupler (2), a spectrometer (3), a laser (4), two single-mode optical fibers (5), two capillary glass tubes (6), two pressure sensing membranes (7) and two reflecting membranes (8), wherein two grooves are formed in one side of the base (1) at intervals, the reflecting membranes (8) are respectively installed on the bottoms of the two grooves, the two pressure sensing membranes (7) are respectively installed in the two grooves, a gap is formed between each pressure sensing membrane (7) in each groove and the reflecting membrane (8) to form a closed FP chamber (9), two transparent materials with different elastic properties are filled in the FP chambers (9), and through grooves penetrating through the base (1) are respectively formed in the bottom wall of each groove, two capillary glass manages (6) and installs two lead to the inslot, and the one end of the two respectively with two reflection of light diaphragm (8) fixed connection, its other end stretches out two respectively lead to the groove, two the one end of single mode fiber (5) is fixed mounting respectively in capillary glass manages (6), and the two terminal surface respectively with reflection of light diaphragm (8) contact, two the other end of single mode fiber (5) is respectively two inputs of coupler (2) are connected, spectrum appearance (3) with laser instrument (4) respectively with two inputs of coupler (2) are connected.

2. The pressure sensing probe based on vernier effect as claimed in claim 1, wherein said base (1) comprises a base (11) and a supporting body (12), said base (11) is provided with two through holes (13) passing through it, said two pressure sensing diaphragms (7) are fixed on said base (11) and respectively sealed at the same end of said two through holes (13), said supporting body (12) is installed at one side of said base (11) on which said pressure sensing diaphragms (7) are provided, and said supporting body (12) is close to one side of said base (11) and forms said groove with said two through holes (13), said reflective diaphragm (8) is installed at one side of said supporting body (12) close to said base (11).

3. A vernier effect based pressure sensing probe according to claim 1, wherein the transparent material in one of the FP chambers (9) is air and the transparent material in the other FP chamber (9) is transparent rubber.

4. A pressure sensor, comprising the pressure sensing probe of claim 2 or 3, further comprising a housing (10), a sealing groove (20) and a pipe sleeve (30), wherein the housing (10) is hollow and has two open ends, one end of the base (11) on which the supporting body (12) is mounted extends into the housing (10) from one open end thereof and is fixedly connected with the housing, a groove wall at the groove opening of the sealing groove (20) is fixedly connected with the other open end of the housing (10), a mounting hole matched with the pipe sleeve (30) is arranged on a groove bottom wall of the sealing groove (20), the pipe sleeve (30) is arranged in the sealing groove (20), and one end of the pipe sleeve, which is close to the mounting hole, extends out of the sealing groove (20) from the mounting hole and is fixedly connected with the same, the coupler (2) is arranged in the housing (10), the optical fiber connected with the input end of the coupler (2) extends out of the sealing groove (20) through the pipe sleeve (30) and is connected with the laser (4) and the spectrometer (3), and a sealing glue (31) is filled between the inner wall of the pipe sleeve (30) and the optical fiber inside the pipe sleeve.

5. The pressure sensor of claim 4, further comprising a seal post (40) disposed within the seal groove (20), the sealing column (40) extends to the interior of the shell (10) near one end thereof and is connected with the shell, the other end of the sealing column (40) is provided with a truncated cone-shaped extrusion head (41), a plurality of opening and closing teeth (32) are arranged in the sealing groove (20), and a plurality of opening and closing teeth (32) are distributed in a same circle by taking the shaft of the extrusion head (41) as the center, the extrusion head (41) extends between the opening and closing teeth (32), which is used for extruding a plurality of opening and closing teeth (32) to cause the opening and closing teeth to generate elastic deformation and expand, the sealing column (40) is provided with an insertion hole which is matched with the mounting hole and penetrates through the mounting hole, one end of the pipe sleeve (30) far away from the sealing groove (20) extends into the jack.

6. A pressure sensor according to claim 5, characterized in that the sealing post (40) is made of a rubber material.

Technical Field

The invention relates to the technical field of optical fiber sensors, in particular to a pressure sensing probe and a pressure sensor based on a vernier effect.

Background

The development of the information technology drives the development of the sensor technology, and the innovation of the sensor technology enables the collection of a plurality of physical quantities in working life to be efficient and accurate, and is particularly outstanding in the innovation of the light sensor. The optical fiber sensor uses optical fibers as a channel, the light waves are used as a carrier to transmit outgoing data, and the measured physical quantity is more accurate than that of a traditional sensor.

The current commonly used electronic pressure gauge and thermometer can only operate in the working environment below 200 ℃ and can not perform long-term continuous real-time monitoring, the oil drainage well measurement and control technology in Steam Assisted Gravity Drainage (SAGD) of oil companies has very important significance, the depth is an important parameter of oil well monitoring and is calculated by hydraulic pressure, and the hydraulic pressure is an important basis for determining the observation level of oil well elements.

Since the pressure of ultra-high oil wells reaches almost 100MPa, the requirements on the working pressure range of the sensor are very high. In the actual use process of the electronic sensor, the piezoresistor is permanently deformed for a long time under the high-pressure environment of the oil well, so that the data of the pressure sensor is greatly drifted, the physical quantity cannot be accurately displayed, meanwhile, the transmission of the liquid under the oil well is interfered by the cable, so that the equipment cannot normally transmit signals and is scrapped, and most feared is a series of disasters such as oil well explosion and the like; the optical fiber pressure sensor has the advantages of being poor in underground petroleum environment, high in sensitivity and accuracy, corrosion resistance, insulativity and chemical stability, anti-electromagnetic interference capacity and high fidelity, the optical fiber pressure sensor has great advantages in underground petroleum high-voltage measurement, however, due to the characteristics of the optical fiber grating, a complex pressure-sensitive structure must be used for a photosensitive material, the accuracy and the stability of the sensor can be affected, and therefore when the optical fiber grating sensor is applied to underground petroleum detection, many accuracy requirements cannot be met.

In order to realize real-time monitoring of pressure changes of these steam injection facilities, it is necessary to develop a pressure sensor suitable for a pressure monitoring system in a high-temperature environment.

Disclosure of Invention

In order to solve the above technical problems, the present invention provides a pressure sensing probe, a pressure sensor and a pressure testing system, which have high accuracy, electrical insulation, strong corrosion resistance and high sensitivity, and are very suitable for pressure measurement under severe environmental conditions:

a pressure sensing probe based on vernier effect comprises a base, a coupler, a spectrometer, a laser, two single-mode fibers, two capillary glass tubes, two pressure sensing membranes and two reflecting membranes, wherein two grooves are formed in one side of the base at intervals, the reflecting membranes are respectively installed on the bottoms of the two grooves, the two pressure sensing membranes are respectively installed in the two grooves, every pressure sensing membrane in each groove is provided with a gap between the corresponding pressure sensing membrane and the corresponding reflecting membrane to form a closed FP (Fabry-Perot) cavity, the FP cavities are filled with two transparent materials with different elastic properties, the bottom wall of each groove is provided with a through groove penetrating through the base, the two capillary glass tubes are installed in the two through grooves, one end of each capillary glass tube is fixedly connected with the two reflecting membranes, and the other end of each capillary glass tube extends out of the two through grooves, two single mode fiber's one end respectively fixed mounting in the capillary glass pipe, and the two terminal surface respectively with reflection of light diaphragm contact, two single mode fiber's the other end respectively two input ends of coupler are connected, the spectrum appearance with the laser instrument respectively with two input ends of coupler are connected.

Preferably, the base includes base and supporter, be equipped with two through-holes that run through it on the base, two pressure sensing diaphragm is fixed on the base to seal respectively two the same one end of through-hole, the supporter is installed be equipped with on the base one side of pressure sensing diaphragm, just the supporter is close to one side and two of base the through-hole constitutes the recess, reflection of light diaphragm installs the supporter is close to one side of base.

Preferably, the transparent material in one of the FP cavities is air, and the transparent material in the other FP cavity is transparent rubber.

A pressure sensor comprises the pressure sensing probe, a shell, a sealing groove and a pipe sleeve, the inner part of the shell is hollow and the two ends of the shell are open, one end of the base, which is provided with the supporting body, extends into the shell from the open end of the shell and is fixedly connected with the shell, the groove wall at the groove opening of the sealing groove is fixedly connected with the other end of the opening of the shell, the groove bottom wall of the sealing groove is provided with a mounting hole matched with the pipe sleeve, the pipe sleeve is arranged in the sealing groove, and one end of the coupler close to the mounting hole extends out of the sealing groove from the mounting hole and is fixedly connected with the sealing groove, the coupler is arranged in the shell, the optical fiber connected with the input end of the coupler extends out of the sealing groove from the pipe sleeve and is connected with the laser and the spectrometer, and sealant is filled between the inner wall of the pipe sleeve and the optical fiber inside the pipe sleeve.

Preferably, still including setting up sealed post in the seal groove, sealed post is close to the one end of casing extends to its inside and is connected with it, the other end of sealed post has the extrusion head that is the round platform shape, be equipped with a plurality of opening in the seal groove and close the tooth, and a plurality of open close the tooth with the axle of extrusion head distributes with the circle as the center, the extrusion head stretches into a plurality ofly open and close between the tooth, it is used for extrudeing a plurality of open and close the tooth and make its production elastic deformation and expand, be equipped with on the sealed post with the jack that the mounting hole cooperation just runs through it, the pipe box is kept away from the one end of seal groove stretches into in the jack.

Preferably, the sealing post is made of a rubber material.

The invention utilizes vernier effect to amplify the sensitivity of the pressure sensing probe and the pressure sensor, realizes high-sensitivity wide-range pressure measurement under the small diameter size, and completes more accurate monitoring in the oil-gas well with corrosive, high-pressure, narrow space and other severe conditions.

The foregoing description is only an overview of the technical solutions of the present invention, and in order to make the technical solutions of the present invention more clearly understood and to implement them in accordance with the contents of the description, the following detailed description is given with reference to the preferred embodiments of the present invention and the accompanying drawings. The detailed description of the present invention is given in detail by the following examples and the accompanying drawings.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the invention without limiting the invention. In the drawings:

FIG. 1 is a schematic structural diagram of a pressure sensing probe according to an embodiment of the present invention;

FIG. 2 is a schematic structural diagram of a pressure sensor according to an embodiment of the present invention;

FIG. 3 is a schematic diagram of a pressure sensor in accordance with an embodiment of the present invention;

FIG. 4 is a schematic structural diagram of a pressure testing system according to an embodiment of the present invention;

FIG. 4a is a spectrum of reflected light from the sensing cavity before and after a pressure change according to an embodiment of the present invention;

FIG. 4b is a graph of the spectrum of reflected light in the reference cavity before and after a pressure change in accordance with an embodiment of the present invention;

FIG. 4c shows interference spectra of light emitted from the sensing chamber and the reference chamber before and after a pressure change according to an embodiment of the present invention.

The specific meanings of the reference numerals are:

1. a base; 11. a base; 12. a support body; 13. a through hole; 2. a coupler; 3. a spectrometer; 4. A laser; 5. a single mode optical fiber; 6. a capillary glass tube; 7. a pressure-sensitive film; 71. a light-reflecting film; 8. a light-reflecting membrane; 9. an FP chamber; 10. a housing; 20. a sealing groove; 30. pipe sleeve; 31. sealing glue; 32. opening and closing teeth; 40. sealing the column; 41. and (4) extruding the head.

The implementation, functional features and advantages of the objects of the present invention will be further explained with reference to the accompanying drawings.

Detailed Description

The principles and features of the present invention are described below in conjunction with the accompanying fig. 1-4, which are provided by way of example only to illustrate the present invention and not to limit the scope of the present invention. The invention is described in more detail in the following paragraphs by way of example with reference to the accompanying drawings. Advantages and features of the present invention will become apparent from the following description and from the claims. It is to be noted that the drawings are in a very simplified form and are not to precise scale, which is merely for the purpose of facilitating and distinctly claiming the embodiments of the present invention.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

Referring to fig. 1-4, an embodiment of the present invention is provided, in which the pressure sensing probe based on the vernier effect includes a base 1, a coupler 2, a spectrometer 3, a laser 4, two single-mode optical fibers 5, two capillary glass tubes 6, two pressure sensing films 7, and two reflecting films 8, two grooves are spaced at one side of the base 1, the reflecting films 8 are respectively mounted on bottoms of the two grooves, the two pressure sensing films 7 are respectively mounted in the two grooves, a gap is formed between the pressure sensing film 7 and the reflecting film 8 in each groove to form a closed FP cavity 9, the two FP cavities 9 are filled with two transparent materials with different elastic properties, through grooves penetrating through the base 1 are respectively formed on bottom walls of the two grooves, the two capillary glass tubes 6 are mounted in the two through grooves, and the two one end respectively with two 8 fixed connection of reflection of light diaphragms, its other end stretches out two respectively lead to the groove, two single mode fiber 5's one end respectively fixed mounting in capillary glass pipe 6, and the two terminal surface respectively with 8 contacts of reflection of light diaphragms, two single mode fiber 5's the other end respectively two inputs of coupler 2 are connected, spectrum appearance 3 with laser instrument 4 respectively with two inputs of coupler 2 are connected.

The cross section of two recesses is circular, two pressure sensing diaphragm 7 is circular, and pressure sensing diaphragm 7 welds respectively in the recess and with two the coaxial distribution of recess.

As shown in fig. 1, after the two pressure sensing diaphragms 7 deform in a pressure environment, light emitted by the laser 4 vertically enters the two reflecting diaphragms 8 through the couplers 2 via the two single-mode fibers 5, a part of the light is reflected, the rest of the light enters the corresponding FP chambers 9 and is reflected by the reflecting films 71 on the pressure sensing diaphragms 7, and then the two reflected lights interfere with each other and enter the spectrometer 3 for display.

Due to the fact that the elastic performance of materials in the two FP chambers 9 is different, when the same external pressure is applied, the deformation degree of the two pressure sensing diaphragms 7 is different, light rays entering the two FP chambers 9 generate optical path difference, reflected light of the two parts generate displacement difference and generate interference, the measuring sensitivity and resolution of optical sensing are refined through vernier effect, and the use accuracy of the pressure sensor is improved.

Because the installation space of the pressure sensor is limited in the oil well, the effective diameter of the pressure sensing diaphragm 7 is 3mm, so that the maximum outer diameter of the sensor is controlled within 10 mm; meanwhile, in consideration of a strong corrosion environment in an oil well, the nickel alloy 625 is adopted as a membrane and other materials of structures which are in direct contact with oil gas; because the temperature in the oil production well is high, the reliability of the sensor is considered, and the temperature of 100 ℃ is selected as the maximum stress value of the sensor diaphragm.

As shown in fig. 1, preferably, the base 1 includes a base 11 and a supporting body 12, two through holes 13 penetrating through the base 11 are provided on the base 11, two pressure sensing diaphragms 7 are fixed on the base 11 and are respectively sealed at the same ends of the two through holes 13, the supporting body 12 is installed at one side of the pressure sensing diaphragm 7 provided on the base 11, one side of the supporting body 12 close to the base 11 and two through holes 13 form the groove, and the light reflecting diaphragm 8 is installed at one side of the supporting body 12 close to the base 11.

The grooves are formed between the two bases 11 and the supporting body 12, so that materials with different elastic properties are filled in the two FP chambers 9.

Preferably, the transparent material in one of the FP cavities 9 is air, and the transparent material in the other FP cavity 9 is transparent rubber.

The air source is wide, and the manufacturing is easy; the transparent rubber has stable performance, and the stability of the performance of the pressure sensing probe is ensured.

Based on the above pressure sensing probe, a pressure sensor is provided, the pressure sensor further includes a housing 10, a sealing groove 20 and a pipe sleeve 30, the housing 10 is hollow and has two open ends, one end of the base 11 where the supporting body 12 is installed extends into the housing 10 from the open end and is fixed with the housing, a groove wall of the groove opening of the sealing groove 20 is fixed with the open other end of the housing 10, a mounting hole matched with the pipe sleeve 30 is arranged on a groove bottom wall of the sealing groove 20, the pipe sleeve 30 is arranged in the sealing groove 20, one end of the pipe sleeve close to the mounting hole extends out of the sealing groove 20 from the mounting hole and is fixed with the sealing groove, the coupler 2 is arranged in the housing 10, an optical fiber connected with an input end of the coupler 2 extends out of the sealing groove 20 from the pipe sleeve 30 and is connected with the laser 4 and the spectrometer 3, and a sealant 31 is filled between the inner wall of the pipe sleeve 30 and the optical fiber inside the pipe sleeve.

Wherein, be equipped with the screw thread on the outer wall of base 11, just the screw thread department cover of 11 outer walls of base is equipped with the sealing washer, the inner wall of the uncovered department of casing 10 one end is equipped with the internal thread, base 11 closes soon through the screw thread the uncovered department of one end of casing 10, the sealing washer distributes casing 10 with between the base 11, again with base 11 with welded seal is passed through in the gap of the threaded connection department of casing 10, guarantees base 11 with the leakproofness of shell is favorable to the extension pressure sensor's life.

Preferably, still including setting up seal post 40 in the seal groove 20, seal post 40 is close to the one end of casing 10 extends to its inside and is connected with it, seal post 40's the other end has the extrusion head 41 that is the round platform shape, be equipped with a plurality of opening in the seal groove 20 and close tooth 32, and is a plurality of opening close tooth 32 with the axle of extrusion head 41 distributes with the circle as the center, extrusion head 41 stretches into a plurality of opening close between the tooth 32, it is used for extrudeing a plurality of opening close tooth 32 makes its production elastic deformation and expand, be equipped with on seal post 40 with the mounting hole cooperation just runs through its jack, pipe sleeve 30 is kept away from the one end of seal groove 20 stretches into in the jack.

An inner groove wall at the groove opening of the sealing groove 20 is provided with an inner thread, the other end of the opening of the shell 10 is provided with a thread, the sealing groove 20 is screwed at the other end of the opening of the shell 10 through the thread, when the pressure sensor is installed and the sealing groove 20 is screwed through external force, the extrusion head 41 extends into the space between the opening and closing teeth 32 and extrudes the opening and closing teeth 32 to generate elastic deformation and expand, and the sealing performance between the sealing groove 20 and the shell 10 is increased; and the other end of the opening of the shell 10 is welded with the sealing groove 20, and the sleeve is welded with the sealing groove 20, so that the sealing effect of the pressure sensor is further improved.

Preferably, the sealing post 40 is made of a rubber material.

When installing pressure sensor, external force is screwed up during seal groove 20, it is a plurality of open and shut tooth 32 extrudees simultaneously sealed post 40 for sealed post 40 is with a plurality of open and shut tooth 32 in close contact with, obtains good leakproofness, just sealed post 40 compresses tightly the sleeve pipe is avoided the sleeve pipe warp.

The FP cavity 9 filled with air is defined as a sensing cavity, the FP cavity 9 filled with rubber material is defined as a reference cavity, the reflected light spectrograms of the sensing cavity before and after pressure change are respectively obtained as shown in fig. 4a, the reflected light spectrograms of the reference cavity before and after pressure change are respectively obtained as shown in fig. 4b, the interference spectrum of the emitted light in the sensing cavity and the reference cavity before and after pressure change is shown in fig. 4c, and the envelope spectrums of the interference spectrum of the emitted light in the sensing cavity and the reference cavity before and after pressure change are simultaneously obtained.

As can be seen from the comparison between fig. 4c and fig. 4a and 4b, the spectral shift Δ λ in fig. 4c is larger than that in fig. 4a and 4b, and it can be seen that the external pressure is amplified by the vernier formed by the reference cavity and the sensing cavity, thereby improving the sensitivity of the pressure sensor.

The foregoing is merely a preferred embodiment of the invention and is not intended to limit the invention in any manner; the present invention may be readily implemented by those of ordinary skill in the art as illustrated in the accompanying drawings and described above; however, those skilled in the art should appreciate that they can readily use the disclosed conception and specific embodiments as a basis for designing or modifying other structures for carrying out the same purposes of the present invention without departing from the scope of the invention as defined by the appended claims; meanwhile, any changes, modifications, and evolutions of the equivalent changes of the above embodiments according to the actual techniques of the present invention are still within the protection scope of the technical solution of the present invention.