A hydrogen detection sensor packaging structure based on micro-nano optical fiber

Abstract

The present invention discloses a hydrogen detection sensor packaging structure based on micro-nano optical fiber, comprising: a hydrogen detection chamber box, a hydrogen detection chamber top cover, a ventilation window, a dustproof grille, a first probe displacement limiting device, a second probe displacement limiting device, and a hydrogen sensor probe; wherein the hydrogen detection chamber top cover is connected to the open end of the cavity of the hydrogen detection chamber box; the ventilation window is connected to the open end of a groove provided in the hydrogen detection chamber top cover; the dustproof grille is connected to the opening of the ventilation window; one end of the hydrogen sensor probe is connected to the first probe displacement limiting device, and the other end of the hydrogen sensor probe is connected to the second probe displacement limiting device; the first probe displacement limiting device and the second probe displacement limiting device are both connected to the bottom of the hydrogen detection chamber box. The present invention solves the technical problem in the prior art that hydrogen detection sensors are not suitable for engineering operation environments with long-term low-frequency vibration, high dust content, and high humidity.

Description

Technical Field

[0001] The present invention belongs to the technical field of gas trace detection, and in particular relates to a hydrogen detection sensor packaging structure based on micro-nano optical fibers. Background Art

[0002] Hydrogen is an important clean energy source with extremely promising applications. Currently, China is vigorously promoting the development of hydrogen energy applications. Hydrogen refueling stations are crucial infrastructure for the industrialization and commercialization of hydrogen fuel cells. However, the most important hydrogen storage devices at hydrogen refueling stations are limited by aging pipelines and gas tanks, which pose a risk of leakage.

[0003] Hydrogen is a flammable and explosive gas. When its concentration in air exceeds 4%, it is highly susceptible to explosion, posing a significant safety hazard. Therefore, it is urgent to develop a hydrogen detection sensor suitable for engineering applications.

[0004] Traditional electrochemical, resistive, and electromagnetic hydrogen sensors have low sensitivity and slow response in hydrogen concentration detection, as well as the risk of electric spark explosion, and have been gradually eliminated. The existing hydrogen detection methods mainly include coating color change detection method and optical fiber coating detection method. Among them, Chinese Patent Authorization Announcement No. CN111174986A discloses a hydrogen detection method based on a hydrogen-discoloring silica gel coating material. The coating material is laid on the outer surface of the pipeline to be detected, and the color of the coating material is compared by regular inspections by inspection personnel to determine whether the hydrogen pipeline is leaking. However, the above method has the problems of wide material laying range, easy loss, and poor repeatability. The hydrogen detection material is exposed to the air environment for a long time and ages, and its performance is easily affected by surrounding environmental factors (such as moisture, dust, microorganisms, etc.). At the same time, the inspection personnel have a large operating range, which is time-consuming and labor-intensive. There is a risk of not discovering hydrogen leaks due to negligence of personnel or lighting factors. Chinese Patent Authorization Publication No. CN110967329A discloses a hydrogen detection system and method based on micro-nano optical fibers. This method utilizes stimulated Raman scattering (SRS) mediated by the rotational Raman transitions of hydrogen molecules to alter the ratio of pump light and Stokes light from the incident light source, thereby detecting hydrogen concentration and improving hydrogen detection sensitivity. However, this detection system fails to account for the effects of environmental factors (such as vibration, dust, and water molecules in the air), resulting in poor system robustness and unsuitable for use in engineering environments. Summary of the Invention

[0005] The technical problem solved by the present invention is: to overcome the shortcomings of the existing technology and provide a hydrogen detection sensor packaging structure based on micro-nano optical fiber, which solves the technical problem that the hydrogen detection sensor in the existing technology is not suitable for engineering working environments with long-term low-frequency vibration, high dust and high humidity.

[0006] The objectives of the present invention are achieved through the following technical solutions: a hydrogen detection sensor packaging structure based on micro-nano optical fiber, comprising: a hydrogen detection chamber box, a hydrogen detection chamber top cover, a ventilation window, a dustproof grille, a first probe displacement limiting device, a second probe displacement limiting device, and a hydrogen sensor probe; wherein the hydrogen detection chamber top cover is connected to the open end of the cavity of the hydrogen detection chamber box; the ventilation window is connected to the open end of the groove opened in the hydrogen detection chamber top cover; the dustproof grille is connected to the open end of the ventilation window; one end of the hydrogen sensor probe is connected to the first probe displacement limiting device, and the other end of the hydrogen sensor probe is connected to the second probe displacement limiting device; the first probe displacement limiting device and the second probe displacement limiting device are both connected to the bottom of the hydrogen detection chamber box; the first probe displacement limiting device, the second probe displacement limiting device and the hydrogen sensor probe are all located in the cavity of the hydrogen detection chamber box.

[0007] In the above-mentioned hydrogen detection sensor packaging structure based on micro-nano optical fiber, the first probe displacement limiting device includes a first probe vibration damper base and a first probe displacement limiting top cover; wherein, the first probe vibration damper base is connected to the first probe displacement limiting top cover.

[0008] In the above-mentioned hydrogen detection sensor packaging structure based on micro-nano optical fiber, the second probe displacement limiting device includes a second probe vibration damper base and a second probe displacement limiting top cover; wherein, the second probe vibration damper base is connected to the second probe displacement limiting top cover.

[0009] In the above-mentioned hydrogen detection sensor packaging structure based on micro-nano optical fiber, the hydrogen sensor probe includes a probe fixing base, a probe fixing top cover, a micro-nano optical fiber, an optical fiber adhesive and a transmission optical fiber air-sealing head; wherein, the probe fixing top cover is connected to the open end of the probe fixing base; the middle part of the micro-nano optical fiber is arranged in a reserved optical fiber bonding groove opened in the probe fixing base through the optical fiber adhesive, one end of the micro-nano optical fiber is connected to the hydrogen detection gas chamber box through the transmission optical fiber air-sealing head, and the other end of the micro-nano optical fiber passes through the hydrogen detection gas chamber box and is connected to the external demodulation end.

[0010] The above-mentioned hydrogen detection sensor packaging structure based on micro-nano optical fiber further includes: a first waterproof and breathable membrane; wherein the first waterproof and breathable membrane is provided between the breathable window and the top cover of the hydrogen detection chamber.

[0011] The above-mentioned hydrogen detection sensor packaging structure based on micro-nano optical fiber also includes: an elastic adhesive; wherein, one end of the hydrogen sensor probe is connected to the first probe displacement limiting device via the elastic adhesive, and the other end of the hydrogen sensor probe is connected to the second probe displacement limiting device via the elastic adhesive.

[0012] The above-mentioned hydrogen detection sensor packaging structure based on micro-nano optical fiber also includes: a vibration damper; wherein the first probe displacement limiting device and the second probe displacement limiting device are both connected to the bottom of the hydrogen detection gas chamber box through the vibration damper.

[0013] In the above-mentioned hydrogen detection sensor packaging structure based on micro-nano optical fiber, the vibration damper includes a vibration-damping rubber and a fastening bolt; wherein the vibration-damping rubber is sleeved on the outer surface of the fastening bolt.

[0014] In the above-mentioned hydrogen detection sensor packaging structure based on micro-nano optical fiber, the hydrogen sensor probe also includes a second waterproof and breathable membrane; wherein the outer side surface of the probe fixed top cover and the outer side surface of the probe fixed base are both provided with the second waterproof and breathable membrane.

[0015] In the above-mentioned hydrogen detection sensor packaging structure based on micro-nano optical fiber, the core taper angle of the micro-nano optical fiber is obtained by the following formula:

[0016]

[0017] Where Ω is the core taper angle of the micro-nano optical fiber, a is the core radius of the micro-nano optical fiber, and β1 and β2 represent the propagation constants of the guided mode and radiative mode of the micro-nano optical fiber, respectively.

[0018] In the above-mentioned hydrogen detection sensor packaging structure based on micro-nano optical fiber, the length of the micro-nano optical fiber after tapering is:

[0019]

[0020] Where L is the initial length of the micro-nano optical fiber, r w is the initial fiber radius of the micro-nano fiber, dr w is the radius change of the central waist region of the micro-nano optical fiber.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] (1) The present invention provides a dust-proof and breathable barrier outside the hydrogen sensor probe by combining the hydrogen detection chamber box and the dust-proof grille in the device, thereby effectively isolating dust particles in the hydrogen sensor detection environment and improving the service life of the hydrogen detection sensor.

[0023] (2) The present invention connects the hydrogen sensor probe to the hydrogen detection chamber box through the vibration damper in the device, thereby effectively isolating the vibration influence of the hydrogen sensor detection environment and improving the accuracy of the hydrogen detection sensor.

[0024] (3) The present invention provides two layers of waterproof and breathable membranes on the outside of the hydrogen sensor probe, thereby effectively isolating water molecules from the hydrogen sensor detection environment and improving the accuracy of the hydrogen detection sensor. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiment below. The accompanying drawings are for illustration purposes only and are not to be considered as limiting the present invention. The same reference symbols are used throughout the drawings to represent the same components. In the drawings:

[0026] Figure 1 Schematic diagram of a hydrogen detection sensor packaging structure based on micro-nano optical fiber provided in an embodiment of the present invention;

[0027] Figure 2 1 is a schematic cross-sectional view of the dustproof and waterproof structure of the hydrogen sensor chamber provided by an embodiment of the present invention;

[0028] Figure 3 This is a cross-sectional view of the internal assembly of the hydrogen sensor chamber provided by an embodiment of the present invention;

[0029] Figure 4 is a schematic diagram of a hydrogen sensor vibration damper installation structure provided by an embodiment of the present invention;

[0030] Figure 5 is a cross-sectional view of the packaging structure of a hydrogen sensor probe provided by an embodiment of the present invention;

[0031] Figure 6 Schematic diagram of a micro-nano optical fiber provided by an embodiment of the present invention;

[0032] Figure 7 This is a schematic diagram of the micro-nano optical fiber after tapering provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0033] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art. It should be noted that, unless there is a conflict, the embodiments of the present disclosure and the features described in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0034] Figure 1 Schematic diagram of a hydrogen detection sensor packaging structure based on micro-nano optical fiber provided in an embodiment of the present invention; Figure 2 1 is a schematic cross-sectional view of the dustproof and waterproof structure of the hydrogen sensor chamber provided by an embodiment of the present invention; Figure 3 This is a cross-sectional view of the internal assembly of the hydrogen sensor chamber provided by an embodiment of the present invention; Figure 4 Schematic diagram of the hydrogen sensor damper installation structure provided by the embodiment of the present invention. Figures 1 to 4 As shown, the hydrogen detection sensor packaging structure based on micro-nano optical fiber includes: a hydrogen detection chamber box 1, a hydrogen detection chamber top cover 4, a ventilation window 5, a dustproof grille 6, a first probe displacement limiting device, a second probe displacement limiting device, and a hydrogen sensor probe 12.

[0035] The hydrogen detection chamber top cover 4 is connected to the open end of the cavity of the hydrogen detection chamber box 1; the air vent 5 is connected to the open end of the groove opened in the hydrogen detection chamber top cover 4; the dustproof grille 6 is connected to the open end of the air vent 5; one end of the hydrogen sensor probe 12 is connected to the first probe displacement limiting device, and the other end of the hydrogen sensor probe 12 is connected to the second probe displacement limiting device; the first probe displacement limiting device and the second probe displacement limiting device are both connected to the bottom of the hydrogen detection chamber box 1; the first probe displacement limiting device, the second probe displacement limiting device and the hydrogen sensor probe 12 are all located in the cavity of the hydrogen detection chamber box 1.

[0036] like Figure 3 As shown, the first probe displacement limiting device includes a first probe vibration damper base 81 and a first probe displacement limiting top cover 101 ; wherein, the first probe vibration damper base 81 is connected to the first probe displacement limiting top cover 101 .

[0037] like Figure 3 As shown, the second probe displacement limiting device includes a second probe vibration damper base 82 and a second probe displacement limiting top cover 102 ; wherein, the second probe vibration damper base 82 is connected to the second probe displacement limiting top cover 102 .

[0038] like Figure 5As shown, the hydrogen sensor probe 12 includes a probe fixing base 13, a probe fixing top cover 14, a micro-nano optical fiber 3, an optical fiber adhesive 16 and a transmission optical fiber gas sealing head 2; wherein, the probe fixing top cover 14 is connected to the open end of the probe fixing base 13; the middle part of the micro-nano optical fiber 3 is arranged in a reserved optical fiber bonding groove opened in the probe fixing base 13 through the optical fiber adhesive 16, one end of the micro-nano optical fiber 3 is connected to the hydrogen detection gas chamber box 1 through the transmission optical fiber gas sealing head 2, and the other end of the micro-nano optical fiber 3 passes through the hydrogen detection gas chamber box 1 and is connected to the external demodulation end.

[0039] The hydrogen detection sensor packaging structure based on micro-nano optical fiber further includes: a first waterproof breathable membrane 80 ; wherein the first waterproof breathable membrane 80 is provided between the breathable window 5 and the top cover 4 of the hydrogen detection chamber.

[0040] The hydrogen detection sensor packaging structure based on micro-nano optical fiber also includes: an elastic adhesive 11; wherein, one end of the hydrogen sensor probe 12 is connected to the first probe displacement limiting device through the elastic adhesive 11, and the other end of the hydrogen sensor probe 12 is connected to the second probe displacement limiting device through the elastic adhesive 11.

[0041] The micro-nano optical fiber-based hydrogen gas detection sensor packaging structure also includes a vibration damper 9. The first and second probe displacement limiting devices are both connected to the bottom of the hydrogen gas detection chamber box 1 via the vibration damper 9. Furthermore, the vibration damper 9 includes a vibration-damping rubber 21 and a fastening bolt 22. The vibration-damping rubber 21 is sleeved onto the outer surface of the fastening bolt 22.

[0042] The hydrogen sensor probe 12 further includes a second waterproof breathable membrane 15 ; wherein, the outer side surface of the probe fixing top cover 14 and the outer side surface of the probe fixing base 13 are both provided with the second waterproof breathable membrane 15 .

[0043] See also Figure 1 The hydrogen detection chamber box 1, the hydrogen detection chamber top cover 4, and the air vent 5 are fixedly connected by fasteners 7. The hydrogen detection chamber box 1 is provided with bottom steps with bolt mounting holes on the left and right sides of the extension direction, which are used to fix the hydrogen sensor to the test platform. The transmission fiber optic gas sealing head 2 is screwed into the threaded mounting hole of the hydrogen detection chamber box 1, and the micro-nano optical fiber 3 extends out of the hydrogen detection chamber box 1 through the transmission fiber optic gas sealing head 2.

[0044] Preferably, the hydrogen sensor should be fixed upside down above the target to be measured. The density of hydrogen is less than that of air. After leakage, it will rise and fill the hydrogen detection chamber box 1 after passing through the air permeable window 5, the dustproof grille 6 and the first waterproof breathable membrane 8, which is more conducive to the hydrogen sensor to detect the hydrogen concentration.

[0045] See also Figure 2The ventilation window 5, the dustproof grille 6 and the first waterproof breathable membrane 80 are pressed into the embedded groove of the hydrogen detection chamber top cover 4 in sequence through the fasteners 7. The ventilation device on the top of the hydrogen detection sensor is installed in the order of the ventilation window 5, the dustproof grille 6, the first waterproof breathable membrane 80 and the hydrogen detection chamber top cover 4, ensuring that the dustproof grille 6 serves as the first isolation device of the hydrogen sensor to isolate the dust, and then isolates the external environmental water vapor through the first waterproof breathable membrane 80, which can improve the service life of the first waterproof breathable membrane 8.

[0046] Preferably, the hydrogen detection chamber box 1, the hydrogen detection chamber top cover 4 and the dustproof grille 6 are all made of aluminum alloy with surface anti-rust treatment, which can reduce the weight of the hydrogen detection sensor and increase its service life.

[0047] Preferably, the first waterproof breathable membrane 80 of the present invention is made of polytetrafluoroethylene, and has breathable micro-pores evenly arranged on its surface.

[0048] See also Figure 3 and Figure 4 The hydrogen sensor probe 12 is bonded to the probe vibration damper base through the elastic adhesive 11. The elastic adhesive 11 is applied to the area where the top of both ends of the hydrogen sensor probe 12 overlaps with the probe vibration damper base, and the probe displacement limiting top cover is pressed tightly against the elastic adhesive 11 applied to the top of the hydrogen sensor probe 12. The probe vibration damper base and the probe displacement limiting top cover are fastened together by fasteners 7, thereby limiting the displacement of the hydrogen sensor probe 12 in the three-dimensional direction.

[0049] Preferably, the elastic adhesive 11 is made of an elastic material having a hardness of Shore 20A to 40A after solidification.

[0050] See also Figure 3 and Figure 4 The center of the extended micro-nano optical fiber 3 in the hydrogen sensor probe 12 is consistent with the center of the transmission optical fiber gas sealing head 2, and the concentricity shall not exceed 0.5 mm.

[0051] See also Figure 4 The installation method of the probe vibration damper base is as follows: insert the vibration damping rubber 21 into the installation reserved holes of the four probe vibration damper bases in turn, and then screw the probe vibration damper base and the vibration damping rubber 21 into the reserved threaded holes of the hydrogen detection chamber box 1 through the fastening bolts 22.

[0052] Preferably, the screwing size of the fastening bolt 22 must strictly comply with the installation specifications of the selected shock absorber 9 and must not exceed the tolerance, and must not cause the vibration damping rubber 21 to be excessively deformed or too loose.

[0053] Preferably, the resonance frequency of the vibration absorber 9 selected in the present invention is 20-100 Hz.

[0054] See also Figure 4 An embedded groove is provided at the bottom of the hydrogen detection chamber box 1. The hydrogen sensor probe 12 is connected to the hydrogen detection chamber box 1 structure only through the probe vibration damper base. That is, after the hydrogen sensor probe 12 is installed, the part of the hydrogen sensor probe 12 exposed outside the probe vibration damper base and the probe displacement limiting top cover is in a suspended state and does not contact other structures.

[0055] See also Figure 5 The hydrogen sensor probe 12 is composed of a second waterproof breathable membrane 15, an elastic adhesive 11, a probe fixing base 13, an optical fiber adhesive 16, a micro-nano optical fiber 3, a probe fixing top cover 14, and a second waterproof breathable membrane 15 from bottom to top. The probe fixing base 13 and the probe fixing top cover 14 are both hollow structures with two sets of reinforcing ribs. During installation, the reinforcing ribs are respectively oriented toward the outside of the hydrogen sensor probe.

[0056] During the assembly process, the micro-nano optical fiber 3 is first tapered, and then the micro-nano optical fiber 3 is moved to the reserved optical fiber bonding groove of the probe fixed base 13, and optical fiber adhesive 16 is applied at two optical fiber preset bonding points. At this time, it is necessary to ensure that the relative position of the micro-nano optical fiber 3 and the probe fixed base 13 does not change, and then the probe fixed top cover 14 is placed above the probe fixed base 13, so that the symmetrical bosses of the probe fixed top cover 14 are embedded in the optical fiber reserved groove of the probe fixed base 13, and then filled with optical fiber adhesive 16; after the optical fiber adhesive 16 is completely solidified, use elastic adhesive 11 to bond a layer of second waterproof and breathable membrane 15 to the outer side of the hydrogen sensor probe frame, that is, the outer surface of the reinforcing rib side frame of the fixed base 13 and the probe fixed top cover 14, to complete the packaging of the hydrogen sensor probe.

[0057] Preferably, the coating thickness of the optical fiber adhesive 16 is in the range of 0.1 to 0.5 mm, and the coating thickness of the elastic adhesive 11 is in the range of 0.05 to 0.3 mm.

[0058] The hydrogen detection chamber box 1 is a "convex" shaped rectangular structure with a hollow structure inside. It is provided with steps and shock absorber mounting holes for installing and fixing the hydrogen sensor structure. Symmetrical earring steps are provided on both sides of the outside, flush with the bottom of the hydrogen detection chamber box 1, and fastener mounting holes are provided on them.

[0059] A threaded through hole is provided on the side of a certain earring step of the hydrogen detection chamber box 1, and the height of the threaded through hole from the center of the hole to the bottom of the box body is 20 to 30 mm.

[0060] A symmetrical "annular runway-type" boss is provided on the top of the opening at the top of the hydrogen detection chamber box 1, and 6 threaded blind holes are embedded in the boss for fixing the hydrogen detection chamber top cover 4.

[0061] The hydrogen detection chamber cover 4 is a symmetrical, rectangular, thin-plate structure with an aspect ratio of 5:1. The bottom of the cover 4 is equipped with a symmetrical, "circular runway" groove and six countersunk bolt holes, connecting it to the hydrogen detection chamber box 1. The top is equipped with two symmetrical, double-layered, downward-pointing steps. The aspect ratio of the upper square step is 2.5:1, and the aspect ratio of the lower square step is 3.5:1. The height ratio of the lower step to the chamber cover is 1:3.5.

[0062] The dustproof grille 6 is made of metal, has a thickness of 0.2 to 0.4 mm, and is evenly distributed with through holes with a diameter of 0.6 to 1 mm.

[0063] The first waterproof breathable membrane 8 and the second waterproof breathable membrane 15 are both made of polytetrafluoroethylene, and have breathable micro-pores evenly arranged on their surfaces.

[0064] The micro-nano optical fiber 3 is made by an optical fiber taper machine and has a length of 10 to 30 cm. Increasing the length is beneficial to improving the detection sensitivity of the hydrogen sensor.

[0065] The probe fixing base 13 is a symmetrical rectangular hollow structure with a length, width and height ratio of 20:2:1. It is provided with three through hollow grooves in the length direction and two sets of reinforcing ribs at the bottom. The ratio of the reinforcing rib height to the height of the probe fixing base 13 is 2:7; at the same time, the probe fixing base 13 is provided with symmetrical optical fiber reserved grooves on both side frames along its length direction, which are used to fix and bond the micro-nano optical fiber 3 to the probe fixing top cover 14.

[0066] The probe fixing top cover 14 has the same length and width as the probe fixing base 13, and the base height is 2 mm; similarly, the probe fixing top cover 14 is also a symmetrical rectangular hollow structure, with three through hollow grooves in its length direction and two groups of reinforcing ribs at the bottom, and the height of the reinforcing ribs is the same as that of the probe fixing top cover 14; the probe fixing top cover 14 is provided with symmetrical boss structures on both side frames along its length direction for pressing the micro-nano optical fiber 3.

[0067] The probe fixing base 13 and the probe fixing top cover 14 are both made of Invar metal material, which has a thermal expansion coefficient much smaller than other metal materials, only 1.5×10 -6 / ℃, which is close to the thermal expansion coefficient of optical fiber and can effectively reduce the temperature variation coefficient of hydrogen sensor.

[0068] The probe fixing base 13 , the micro-nano optical fiber and the probe fixing top cover 14 are connected by an elastic adhesive 11 , and the elastic adhesive 11 is applied to the optical fiber reserved grooves on both sides of the probe fixing base 13 .

[0069] The second waterproof breathable membrane 15 is bonded and fixed to the outer side of the reinforcement ribs of the probe fixing base 13 and the probe fixing top cover 14 by elastic adhesive 11, serving as the second waterproof protective layer of the hydrogen sensor. This waterproof breathable membrane does not need to be replaced daily.

[0070] The probe vibration damper base and the probe displacement limiting top cover are both made of aluminum alloy. When connected, they can limit the displacement of the hydrogen sensor in three dimensions. By cooperating with the vibration damper 9, the damage to the hydrogen detection sensor caused by low-frequency vibration in the environment can be reduced, effectively improving the lifespan and precision reliability indicators of the micro-nano optical fiber 3.

[0071] One side of the transmission optical fiber gas sealing head 2 is a mounting thread, and the other side is a screw-on foot pad clamping locking sleeve, which is used to connect the micro-nano optical fiber and the optical fiber protection sleeve, where the outer diameter of the optical fiber protection sleeve is 2mm.

[0072] like Figure 6 As shown, the core taper angle of the micro-nano optical fiber 3 is obtained by the following formula:

[0073]

[0074] Wherein, Ω is the core taper angle of the micro-nano optical fiber 3, a is the core radius of the micro-nano optical fiber 3, β1 and β2 represent the propagation constants of the guided mode and the radiation mode of the micro-nano optical fiber 3, respectively.

[0075] The core taper angle formula of the micro-nano optical fiber 3 can effectively reduce the propagation loss of the Wiener optical fiber 3, while improving the consistency of the micro-nano optical fiber, the core component of the hydrogen detection sensor.

[0076] like Figure 7 As shown, the micro-nano optical fiber 3 is stretched to a length L after tapering. w Length L w It is obtained by the following formula:

[0077]

[0078] Wherein, L is the initial length of the micro-nano optical fiber 3, r w is the initial fiber radius of the micro-nano fiber 3, dr w is the radius change of the central waist region of the micro-nano optical fiber 3.

[0079] The above formula can effectively control and increase the length of the micro-nano optical fiber 3, thereby improving the sensitivity of the hydrogen detection sensor.

[0080] The probe fixing base and the probe fixing top cover of this embodiment are hollow rectangular structures with the same length and width, and are each provided with two sets of reinforcing ribs on the outside. The probe fixing base and the probe fixing top cover are made of the metal material Invar alloy, which has high strength and extremely low thermal expansion coefficient, which is similar to the thermal expansion coefficient of micro-nano optical fiber, effectively reducing the temperature sensitivity of the hydrogen sensor from the physical structure level.

[0081] The top cover of the hydrogen detection chamber in this embodiment is provided with a first waterproof and breathable membrane, and the outer side surfaces of the hydrogen sensor probe fixing base and the probe fixing top cover are provided with a second waterproof and breathable membrane, which effectively isolates the water molecules outside the hydrogen detection chamber and prevents the hydrogen sensor from affecting the detection accuracy of hydrogen concentration when working in a humid environment.

[0082] The hydrogen sensor of this embodiment is equipped with four customized vibration dampers between the hydrogen probe and the hydrogen detection chamber, with a resonant frequency of 20 to 100 Hz. The symmetrical installation effectively reduces the impact of external vibration response on the hydrogen sensor.

[0083] Although the present invention has been disclosed above in terms of preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art may make possible changes and modifications to the technical solutions of the present invention by using the methods and technical contents disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solutions of the present invention shall fall within the scope of protection of the technical solutions of the present invention.

Claims

1. A hydrogen detection sensor packaging structure based on micro-nano optical fiber, characterized in that include: A hydrogen detection chamber box (1), a hydrogen detection chamber top cover (4), a ventilation window (5), a dustproof grille (6), a first probe displacement limiting device, a second probe displacement limiting device, and a hydrogen sensor probe (12); wherein, The hydrogen detection chamber top cover (4) is connected to the open end of the cavity of the hydrogen detection chamber box (1); The air-permeable window (5) is connected to the open end of the groove provided on the top cover (4) of the hydrogen detection chamber; The dustproof grille (6) is connected to the open end of the air vent (5); One end of the hydrogen sensor probe (12) is connected to the first probe displacement limiting device, and the other end of the hydrogen sensor probe (12) is connected to the second probe displacement limiting device; The first probe displacement limiting device and the second probe displacement limiting device are both connected to the bottom of the hydrogen detection chamber box (1); the first probe displacement limiting device, the second probe displacement limiting device and the hydrogen sensor probe (12) are all located in the cavity of the hydrogen detection chamber box (1); The hydrogen sensor probe (12) comprises a probe fixing base (13), a probe fixing top cover (14), a micro-nano optical fiber (3), an optical fiber adhesive (16) and a transmission optical fiber gas sealing head (2); wherein, The probe fixing top cover (14) is connected to the open end of the probe fixing base (13); The middle portion of the micro-nano optical fiber (3) is arranged in a reserved optical fiber bonding groove provided on the probe fixing base (13) via an optical fiber adhesive (16); one end of the micro-nano optical fiber (3) is connected to the hydrogen detection chamber box (1) via the transmission optical fiber air sealing head (2); the other end of the micro-nano optical fiber (3) passes through the hydrogen detection chamber box (1) and is connected to an external demodulation end; It also includes: a first waterproof and breathable membrane (80); wherein the first waterproof and breathable membrane (80) is provided between the breathable window (5) and the top cover (4) of the hydrogen detection chamber; It also includes: an elastic adhesive (11); wherein one end of the hydrogen sensor probe (12) is connected to the first probe displacement limiting device via the elastic adhesive (11), and the other end of the hydrogen sensor probe (12) is connected to the second probe displacement limiting device via the elastic adhesive (11); The core taper angle of the micro-nano optical fiber (3) is obtained by the following formula: Wherein, Ω is the core taper angle of the micro-nano optical fiber (3), a is the core radius of the micro-nano optical fiber (3), and β1 and β2 represent the propagation constants of the guided mode and the radiation mode of the micro-nano optical fiber (3), respectively.

2. The micro-nano optical fiber-based hydrogen detection sensor packaging structure according to claim 1, characterized in that: The first probe displacement limiting device comprises a first probe vibration damper base (81) and a first probe displacement limiting top cover (101); wherein the first probe vibration damper base (81) is connected to the first probe displacement limiting top cover (101).

3. The micro-nano optical fiber-based hydrogen detection sensor packaging structure according to claim 1, characterized in that: The second probe displacement limiting device comprises a second probe vibration damper base (82) and a second probe displacement limiting top cover (102); wherein the second probe vibration damper base (82) is connected to the second probe displacement limiting top cover (102).

4. The hydrogen detection sensor packaging structure based on micro-nano optical fiber according to claim 1 is characterized in that Also includes: A vibration damper (9); wherein the first probe displacement limiting device and the second probe displacement limiting device are both connected to the bottom of the hydrogen detection chamber box (1) through the vibration damper (9).

5. The micro-nano optical fiber-based hydrogen detection sensor packaging structure according to claim 4, characterized in that: The vibration damper (9) comprises a vibration damping rubber (21) and a fastening bolt (22); wherein the vibration damping rubber (21) is sleeved on the outer surface of the fastening bolt (22).

6. The micro-nano optical fiber-based hydrogen detection sensor packaging structure according to claim 1, characterized in that: The hydrogen sensor probe (12) further comprises a second waterproof breathable membrane (15); wherein the outer side surface of the probe fixing top cover (14) and the outer side surface of the probe fixing base (13) are both provided with the second waterproof breathable membrane (15).

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