Metal oxide semiconductor resistance type hydrogen sensor integrated with electromagnetic heating

Abstract

The invention discloses a metal oxide semiconductor resistive hydrogen sensor integrated with electromagnetic heating, and belongs to the technical field of hydrogen sensors. The substrate comprises a sensor base and an induction metal ring; the sensing metal ring is arranged on the outer surface of the sensor substrate; a gas sensitive material covering layer is arranged on the outer surface of the substrate; a protective shell with a hollow structure is arranged on the outer side of the gas-sensitive material covering layer, and an induction coil connected with a heating power supply is arranged on the inner surface of the protective shell; a gap is reserved between the induction coil and the gas sensitive material; two lead electrodes for connecting a gas sensitive material are arranged on the substrate. By adopting the technical scheme, the electromagnetic heating technology is integrated in the hydrogen sensor, the efficient and uniform heating of the gas sensitive material can be realized, and the detection precision of the hydrogen sensor is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of hydrogen sensors, and in particular relates to a metal oxide semiconductor resistive hydrogen sensor with integrated electromagnetic heating. Background Art

[0002] Metal oxide semiconductor (MOS) chemiresistor sensors have shown great development potential in the field of environmental monitoring and combustible gas detection due to their excellent stability, excellent repeatability and easy miniaturization. They are widely considered to be one of the most promising sensing technologies. The operating principle of this type of sensor mainly relies on the adsorption of oxygen molecules on the surface of metal oxide semiconductor materials. Therefore, in order to improve its detection sensitivity and other performance, it is usually necessary to heat it. However, this method has low sensitivity for hydrogen detection, and the manufacturing process is relatively complicated and the cost is relatively high.

[0003] At present, the traditional resistance wire heating method has certain limitations, such as complex structure, low integration, and the need to transfer heat through the substrate medium, which leads to low heating efficiency and uneven heat distribution. In order to overcome these problems, people have tried to prepare platinum resistance wire and heat it, while performing temperature control and compensation. This method improves the heating temperature and accuracy to a certain extent, but it also makes the process more complicated, and the complexity of the system is also increased, which leads to an increase in cost. Summary of the invention

[0004] The purpose of the present invention is to meet practical needs and provide a metal oxide semiconductor resistive hydrogen sensor with integrated electromagnetic heating. The electromagnetic heating technology is integrated into the hydrogen sensor, which can achieve efficient and uniform heating of the gas-sensitive material and improve the detection accuracy of the hydrogen sensor.

[0005] In order to achieve the above technical objectives, the first objective of the present invention is to provide a metal oxide semiconductor resistive hydrogen sensor with integrated electromagnetic heating, comprising a substrate; the substrate comprises a sensor base and an inductive metal ring; the inductive metal ring is arranged on the outer surface of the sensor base; a gas-sensitive material covering layer is arranged on the outer surface of the substrate; a protective shell with a hollow structure is arranged on the outer side of the gas-sensitive material covering layer, and an induction coil connected to a heating power supply is arranged on the inner surface of the protective shell; a gap is left between the induction coil and the gas-sensitive material; two lead electrodes for connecting the gas-sensitive material are arranged on the substrate.

[0006] Preferably: a groove is provided on the outer surface of the sensor substrate, and the inductive metal ring is embedded in the groove.

[0007] Preferably: the protection shell includes a grille protection bin and a protection bin cover; wherein: the grille protection bin includes a bottom plate, and a grille assembly is fixedly mounted on the upper surface of the bottom plate; the grille assembly includes a plurality of grille bars that are parallel to each other and do not contact each other; the bottom plate and the protection bin cover are parallel to each other; and support grooves for limiting the substrate are provided on the opposite surfaces of the bottom plate and the protection bin cover.

[0008] Preferably, a spiral groove for placing the induction coil is provided on the inner surface of the grid assembly.

[0009] Preferably: the heating power supply is provided with a current regulator and a frequency regulator.

[0010] Preferably, a variable resistor is provided between the heating power supply and the induction coil.

[0011] Preferably, a positioning hole and a supporting groove are provided at the connection portion between the substrate and the protective shell.

[0012] Preferably, the sensor substrate is made of glass or ceramic material.

[0013] Preferably, the number of the induction metal rings is 5 to 10.

[0014] Preferably, the effective cross-sectional area of ​​the inductive metal ring is 1 / 5 to 1 / 2 of the cross-sectional area of ​​the substrate.

[0015] Compared with the prior art, the advantages and positive effects of this application are:

[0016] The uniqueness of the present invention lies in that it cleverly incorporates an electromagnetic heating mechanism into the structure of the hydrogen sensor, so that the concentration of hydrogen can be detected quickly and accurately, meeting the demand for rapid and high-precision detection of hydrogen concentration. Specifically, the design of the present invention cleverly embeds an induction coil into the inner wall of the grille protection compartment, and cleverly clamps an induction metal ring on the outer surface of the sensor base through a groove. A layer of gas-sensitive material is also specially coated on the outer surface of the induction metal ring. Such a design not only ensures the stability of the assembly structure between the various components, but also enables rapid and uniform electromagnetic heating.

[0017] In general, the present invention realizes direct and uniform heating of the gas-sensitive material on the substrate through this innovative design, which not only improves the heating efficiency, but also significantly improves the heating effect. More importantly, according to the heating requirements of the sensor, the present invention also allows the user to independently select the parameters of the inductive metal ring, thereby realizing flexible adjustment of the heating temperature. This design effectively suppresses the peak temperature that may occur in the center of the sensor, ensuring the stability and reliability of the sensor during operation. Through this innovative heating mechanism, the present invention not only improves the performance of the hydrogen sensor, but also extends its service life, bringing new technological breakthroughs to the field of hydrogen detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 It is an overall assembly diagram of a preferred embodiment of the present invention;

[0020] Figure 2 An exploded view of a preferred embodiment of the present invention;

[0021] Figure 3 This is a schematic diagram of the structure of the grille protection bin in a preferred embodiment of the present invention;

[0022] Figure 4 for Figure 3 AA section view;

[0023] Figure 5 This is a front view of the protective compartment cover in a preferred embodiment of the present invention;

[0024] Figure 6 A side view of a protective compartment cover in a preferred embodiment of the present invention;

[0025] Figure 7 for Figure 6 BB cross-section diagram;

[0026] Figure 8 This is a schematic diagram of the structure of a hydrogen sensor in a preferred embodiment of the present invention;

[0027] Fig. 9 for Figure 8 CC profile of ;

[0028] Fig.10 It is a schematic diagram of the structure of the induction metal ring in the preferred embodiment of the present invention;

[0029] Fig.11 for Fig.10 DD profile diagram;

[0030] Fig.12 It is a structural schematic diagram of the induction coil in a preferred embodiment of the present invention;

[0031] Fig.13 for Fig.12 EE profile of

[0032] Fig.14 4 is a working circuit diagram of a preferred embodiment of the present invention. DETAILED DESCRIPTION

[0033] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. The components of the embodiments of the present invention generally described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents the selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative work belong to the scope of protection of the present invention.

[0034] In the description of the invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the invention can be understood according to specific circumstances.

[0035] See also Figures 1 to 14 ,

[0036] A metal oxide semiconductor resistive hydrogen sensor with integrated electromagnetic heating, mainly comprising:

[0037] Substrate 3; the substrate 3 is a cylindrical structure as a whole; the substrate 3 mainly includes a sensor substrate 302 and a sensing metal ring 401; the sensing metal ring 401 is arranged on the outer surface of the sensor substrate 302;

[0038] A covering layer formed of a gas-sensitive material 5, the covering layer being arranged on the outer surface of the substrate 3;

[0039] A protective shell, which is arranged on the outside of the gas-sensitive material 5 covering layer;

[0040] The induction coil 402 is connected to the heating power supply and is arranged on the inner surface of the protective shell; a gap is left between the induction coil 402 and the gas-sensitive material 5, that is, the two are not in direct contact; two lead electrodes for connecting the gas-sensitive material are arranged on the substrate 3.

[0041] A sensor chamber is formed between the protective shell and the substrate 3 , the induction coil 402 and the gas-sensitive material 5 are located in the sensor chamber, and the induction metal ring 401 is located between the substrate 3 and the gas-sensitive material 5 .

[0042] On the basis of the above embodiments, in order to achieve structural stability, the present application may also adopt one or more of the following additional technical features:

[0043] A groove is provided on the outer surface of the sensor substrate 302, and the size of the groove is equivalent to the size of the induction metal ring, and the induction metal ring 401 is embedded in the groove. The groove can prevent the induction metal ring 401 from moving left and right; the position of the groove is required to be within the range covered by the induction coil and covered by the gas-sensitive material.

[0044] The protective shell is in a hollow cylindrical shape. Specifically, the protective shell mainly includes a grille protection bin 1 and a protection bin cover 2; wherein: the grille protection bin 1 includes a bottom plate ( Figure 2 The bottom plate is a circular sheet structure, and the upper surface of the bottom plate ( Figure 1 A grille assembly is fixedly mounted on the right surface of the leftmost circular piece in the figure; the grille assembly includes a plurality of grille bars 101 that are parallel to each other and do not touch each other; the bottom plate and the protective compartment cover 2 are parallel to each other; and supporting grooves 103 for limiting the position of the substrate 3 are arranged on the opposite surfaces of the bottom plate and the protective compartment cover 2. The bottom plate and the protective compartment cover 2 are located at both ends of the grille assembly, and the protective compartment cover 2 and the grille assembly are in a detachable relationship, which facilitates the disassembly and assembly of the components in the sensor chamber.

[0045] In this embodiment, a grid assembly is provided on the protective housing, and the gap and opening size of the grid can be set to different gap sizes according to different working environments.

[0046] The induction coil needs to cover the gas-sensitive material and be fixed on the inner side of the grille protection compartment.

[0047] A spiral groove 102 for placing the induction coil 402 is provided on the inner surface of the grid assembly.

[0048] The heating power supply is provided with a current regulator and a frequency regulator. The induction coil passes through the grid assembly and is connected to an external power supply. The temperature rise speed of the induction metal ring is controlled by controlling the magnitude and frequency of the current.

[0049] A variable resistor is provided between the heating power supply and the induction coil 402. When the induction coil is working, the heating temperature requirement can be controlled on demand under different conditions through the variable resistor connected in series.

[0050] A positioning hole and a supporting groove are provided at the connection portion between the substrate 3 and the protective shell.

[0051] The sensor substrate 302 is made of glass, ceramic or the like, which is insulating, high-strength, and does not react to the heat of the induction metal ring.

[0052] The induction metal rings are evenly distributed between the gas-sensitive material and the substrate. In order to make the sensor heat more efficiently and evenly, the number of the induction metal rings 401 is 5 to 10. The effective cross-sectional area of ​​the induction metal ring 401 is 1 / 5 to 1 / 2 of the cross-sectional area of ​​the substrate 3. The specific parameters are determined according to the required heating requirements, and the material is selected with better electromagnetic induction performance.

[0053] During use, the components are installed in the above-mentioned assembly relationship and placed in the grid protection compartment. The substrate 3 is accurately installed in the center of the circular axis through the positioning hole 201 and the support groove 202. At this time, the induction coil is energized, and the electromagnetic field generated by the induction coil causes the induction metal ring 401 to generate an induced current. Under the action of the induced current, the induction metal ring 401 is heated. Since the induction coil 402 covers all the gas-sensitive materials, the heating effect is more uniform and the heating efficiency is improved.

[0054] Working principle: After the induction coil is powered on, a high-frequency magnetic field is generated inside the induction coil based on the principle of electromagnetic induction. The induction metal ring generates heat in the high-frequency magnetic field, thereby directly heating the gas-sensitive material. The test electrodes are connected to both sides of the gas-sensitive material, respectively, and the electrochemical signals of the gas-sensitive material in a hydrogen environment are measured. The hydrogen concentration is calculated based on the measured electrochemical signals. The calculation process is a well-known technique in the art and will not be described in detail here.

[0055] The grid protection bin can be a cylinder designed in the style of a uniform grid, with built-in grooves at both ends of the cylinder for positioning, fixing the substrate in the grid protection bin. The inner surface of the side wall of the grid protection bin is provided with a spiral groove 102, and the induction coil is clamped in the spiral groove 102 to prevent displacement due to vibration during operation. Grooves of appropriate size are provided on both sides of the above-mentioned grid protection bin, and positioning holes are provided for positioning to prevent eccentric installation of the substrate.

[0056] The heating module mainly includes an induction coil, and the effective induction range of the induction coil should cover the gas-sensitive material to achieve sufficient heating of the gas-sensitive material.

[0057] In the present application, the substrate 3 is installed at the center of the circular axis of the grid protection bin 1 through the support shaft 303 and the positioning hole 304. The grid protection bin 1 is cylindrical and hollowed out to form a grid structure.

[0058] The induction metal ring 401 is fixed on the groove structure set on the sensor substrate 302, and the gas-sensitive material is coated on the induction metal ring 401 and the sensor substrate 302. When the induction coil 402 is energized, the induction metal ring 401 generates induced eddy currents inside to generate heat, thereby heating the gas-sensitive material.

[0059] The hydrogen sensor based on electromagnetic heating in this embodiment is assembled and spliced ​​in a manner such that the substrate 3 is located at the center of the grid protection chamber 1 , and the induction coil 402 is positioned by the spiral groove 102 on the grid protection chamber 1 , and the induction coil 402 is arranged between the grid protection chamber 1 and the grid 3 .

[0060] Firstly, the hydrogen sensor is placed in the grid protection chamber 1 , and then the protection chamber cover 2 is closed, and the substrate 3 is positioned and fixed through the support groove 201 and the hydrogen positioning hole 202 .

[0061] The area covered by the induction metal ring 401 on the sensor base 302 is larger than the gas-sensitive material 301, so that the heating speed of the sensor base 302 is increased, a better heating effect is achieved, heating is uniform, and heating efficiency is improved. The induction coil 402 is abutted against the spiral groove 102 and is made of copper material.

[0062] The sensor substrate 302 is made of ceramic material, and the surface is grooved for embedding the inductive metal ring, so that it can respond more quickly and has better heating efficiency.

[0063] Working principle: When a high-frequency magnetic field passes through the induction coil, an induced eddy current is generated inside, generating heat. According to the relevant formulas of the electric power consumed by the electromagnetic induction coil and the inductance, volume, and effective cross-sectional area of ​​the induction metal ring, the heating efficiency of induction heating can be achieved by increasing the current size, the thickness and width of the metal ring, and the number of turns of the induction coil.

[0064] The grid bars 101 of the grid protection chamber 1 play a role in protecting the substrate 3 and in allowing hydrogen to flow in.

[0065] The present application integrates a heating technical solution for a hydrogen sensor, specifically adopting an electromagnetic heating method, which has the advantages of high heating efficiency, uniform heating and high integration.

[0066] 1. The grid protection compartment of the grid structure cylinder has a built-in groove to fix the induction coil;

[0067] 2. The outer surface of the sensor substrate 302 is embedded with a sensing metal ring.

[0068] 3. The induction coil and the metal ring interact with each other for heating, which not only improves the heating uniformity and heating efficiency, but also improves the integration of the sensor and the heating module;

[0069] 4. The electromagnetic heating method of the induction coil has a low driving voltage and is easy to integrate the sensor with the circuit.

[0070] The above description is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, without departing from the principle of the present invention, these improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A metal oxide semiconductor resistive hydrogen sensor with integrated electromagnetic heating, characterized in that: The invention comprises a substrate (3); the substrate (3) comprises a sensor base (302) and an induction metal ring (401); the induction metal ring (401) is arranged on the outer surface of the sensor base (302); a gas-sensitive material (5) covering layer is arranged on the outer surface of the substrate (3); a protective shell with a hollow structure is arranged on the outer side of the gas-sensitive material (5) covering layer, and an induction coil (402) connected to a heating power source is arranged on the inner surface of the protective shell; a gap is left between the induction coil (402) and the gas-sensitive material (5); and two lead electrodes for connecting the gas-sensitive material are arranged on the substrate (3).

2. The metal oxide semiconductor resistive hydrogen sensor with integrated electromagnetic heating according to claim 1, characterized in that: A groove is provided on the outer surface of the sensor substrate (302), and the inductive metal ring (401) is embedded in the groove.

3. The metal oxide semiconductor resistive hydrogen sensor with integrated electromagnetic heating according to claim 2, characterized in that: The protective shell comprises a grille protection bin (1) and a protection bin cover (2); wherein: the grille protection bin (1) comprises a bottom plate, on the upper surface of which a grille assembly is fixedly mounted; the grille assembly comprises a plurality of grille bars (101) which are parallel to each other and do not contact each other; the bottom plate and the protection bin cover (2) are parallel to each other; and support grooves (103) for limiting the position of a substrate (3) are provided on the opposite surfaces of the bottom plate and the protection bin cover (2).

4. The metal oxide semiconductor resistive hydrogen sensor with integrated electromagnetic heating according to claim 3, characterized in that: A spiral groove (102) for placing an induction coil (402) is provided on the inner surface of the grid component.

5. The metal oxide semiconductor resistive hydrogen sensor with integrated electromagnetic heating according to claim 1, characterized in that: The heating power supply is provided with a current regulator and a frequency regulator.

6. The metal oxide semiconductor resistive hydrogen sensor with integrated electromagnetic heating according to claim 1, characterized in that: A variable resistor is provided between the heating power source and the induction coil (402).

7. The metal oxide semiconductor resistive hydrogen sensor with integrated electromagnetic heating according to claim 1, characterized in that: A positioning hole and a supporting groove are provided at the connection portion between the substrate (3) and the protective shell.

8. The metal oxide semiconductor resistive hydrogen sensor with integrated electromagnetic heating according to claim 1, characterized in that: The sensor substrate (302) is made of glass or ceramic material.

9. The metal oxide semiconductor resistive hydrogen sensor with integrated electromagnetic heating according to claim 1, characterized in that: The number of the induction metal rings (401) is 5 to 10.

10. The metal oxide semiconductor resistive hydrogen sensor with integrated electromagnetic heating according to claim 1, characterized in that: The effective cross-sectional area of ​​the inductive metal ring (401) is 1 / 5 to 1 / 2 of the cross-sectional area of ​​the substrate (3).

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