A hydrogen sensor

Abstract

The utility model relates to a kind of hydrogen sensors.The hydrogen sensor includes shell and upper cover, upper cover is provided with the gas inlet hole through along the height direction of upper cover, the gas inlet hole is microchannel, diameter is 0.1-2.0mm, length is 1.5-4.5mm.Working electrode is fixedly arranged on the inner side surface of upper cover in shell, and working electrode is set to be opposite to the gas inlet hole, so that the gas in the gas inlet hole can quickly diffuse to working electrode.The gas inlet hole is microchannel in the utility model, since H2 molecule has smaller volume than CO, H2 reaches working electrode with faster diffusion characteristics, which can effectively reduce the cross interference of CO on H2.Gas directly diffuses to working electrode from gas inlet hole, greatly shortens the time of gas diffusion, and accelerates the response time of sensor.

Description

Technical Field

[0001] This utility model relates to the field of gas sensor technology, specifically to a hydrogen sensor. Background Technology

[0002] Hydrogen is a clean and renewable energy source that can power vehicles, with water as its only emission, making hydrogen fuel cells a preferred option for new energy vehicles. However, hydrogen mixed with air is highly flammable, requiring particularly effective sensors for monitoring. Detecting hydrogen is extremely challenging. This gas is invisible and odorless, but highly volatile and flammable; only 4% hydrogen in the air is needed to produce hydrogen-oxygen gas, sometimes called a hydrogen-oxygen mixture, and even the smallest spark can ignite it. To ensure the safety of future hydrogen fuel cell vehicles and related infrastructure, it is essential to detect even minute amounts of hydrogen in the air, and hydrogen sensors must respond quickly enough to detect leaks before a fire occurs. However, CO, with similar chemical properties to H2, is considered one of the strongest interfering gases in H2 sensing.

[0003] Existing hydrogen sensors, including housings and top covers, such as Figure 1 As shown, the upper cover includes a cover plate 1, a gas chamber 6 is provided on the upper side of the cover plate, a sealing plate 2 is provided at the opening of the gas chamber, and an air inlet 4 is provided on the sealing plate. A working electrode 3 is heat-fused to the lower side of the cover plate. Gas enters the gas chamber 6 through the air inlet 4, and then diffuses from the gas chamber to the working electrode, at which point the sensor generates a response. Due to the presence of the intermediate gas chamber, the time for gas to diffuse to the working electrode is relatively long, resulting in a long response time for the sensor. Moreover, both H2 and CO in the gas can diffuse from the gas channel to the working electrode, making the resistance to CO interference poor. Utility Model Content

[0004] The purpose of this invention is to provide a hydrogen sensor to solve the technical problems of poor resistance to CO interference and slow response in the prior art.

[0005] To achieve the above objectives, the present invention provides a hydrogen sensor with the following technical solution: a hydrogen sensor comprising a housing and a top cover, the top cover having an air inlet hole extending along the height direction of the top cover, the air inlet hole being a microchannel with a diameter of 0.1-2.0 mm and a length of 1.5-4.5 mm; a working electrode is fixedly disposed inside the housing on the lower side of the top cover, the working electrode being positioned directly opposite the air inlet hole, so that the gas entering the air inlet hole can diffuse directly onto the working electrode.

[0006] The diameter of the air inlet is 0.5 mm and the length is 3.2 mm.

[0007] The upper side of the cover is provided with a first groove with the opening facing upward, and the air inlet of the air inlet is located on the bottom of the first groove.

[0008] The lower side of the top cover is provided with a second groove with the opening facing downwards. The air outlet of the air inlet is located on the bottom of the second groove. The second groove is for the installation of the filter layer, and the working electrode covers the filter layer.

[0009] The beneficial effects of this invention are as follows: In this invention, the air inlet is a microchannel. Because H2 molecules have a smaller volume than CO molecules, H2 diffuses faster and preferentially reaches the working electrode, effectively reducing the cross-interference of CO with H2. The gas diffuses directly from the air inlet of the microchannel to the working electrode, greatly shortening the gas diffusion time and accelerating the sensor's response time. Attached Figure Description

[0010] Figure 1 This is a schematic diagram of the structure of the upper cover of the hydrogen sensor in the background technology;

[0011] Figure 2 This is a schematic diagram of the structure of a hydrogen sensor according to a first embodiment of the present invention;

[0012] Figure 3 yes Figure 2 A sectional view;

[0013] Figure 4 This is a response time curve of the hydrogen sensor with the structure of Embodiment 1 of this utility model and the hydrogen sensor with the structure of the comparative example. Detailed Implementation

[0014] To facilitate understanding of this utility model, a more detailed description is provided below with reference to the accompanying drawings and specific embodiments. The accompanying drawings show preferred embodiments of this utility model. However, this utility model can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the disclosure of this utility model.

[0015] It should be noted that, unless otherwise defined, the technical and scientific terms used in this specification have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The use of "belonging" in this specification is for the purpose of describing particular embodiments only and is not intended to limit the scope of this invention.

[0016] An embodiment of a hydrogen sensor according to this utility model is as follows: Figures 2-3As shown, the device includes a housing and a top cover 1. The top cover 1 has an air inlet 2 extending along its height. The air inlet 2 is a microchannel designed to restrict the airflow of incoming gas. The microchannel is defined as having a diameter between 0.1-2.0 mm and a length between 1.5-4.5 mm. In this embodiment, the diameter of the air inlet 2 is 0.5 mm, and the length is 3.2 mm. A working electrode 3 is fixedly disposed inside the housing on the lower side of the top cover 1. In this embodiment, the working electrode is thermally fused to the top cover 1. The working electrode 3 is positioned directly opposite the air inlet 2, allowing the gas entering the air inlet to diffuse directly onto the working electrode. The microchannel design offers the following advantages: because H2 molecules have a smaller volume than CO, H2 diffuses faster and preferentially reaches the working electrode, effectively reducing the cross-interference of CO with H2. Furthermore, the gas can diffuse directly from the air inlet to the working electrode, significantly shortening the gas diffusion time and accelerating the sensor's response time.

[0017] The upper side of the top cover 1 has an upward-facing first groove 4, and the air inlet of the air inlet 2 is located on the bottom of the first groove 4. The first groove serves two purposes: firstly, since the top cover and the housing need to be ultrasonically welded together, the first groove prevents the microchannels from being blocked during the ultrasonic welding process, thus affecting gas entry; secondly, it buffers the airflow, slowing down the speed of the gas entering the air inlet, which improves the consistency of sensor sensitivity. The lower side of the top cover 1 has a downward-facing second groove 5, and the air outlet of the air inlet 2 is located on the bottom of the second groove 5. The second groove serves to accommodate the filter layer, with the working electrode covering the filter layer.

[0018] This utility model provides a second embodiment of a hydrogen sensor, which differs from the first embodiment only in the size of the air inlet. In this embodiment, the diameter of the air inlet is 0.1 mm and the length is 1.5 mm.

[0019] This invention relates to a third embodiment of a hydrogen sensor, which differs from the first embodiment only in the size of the air inlet. In this embodiment, the diameter of the air inlet is 2.0 mm and the length is 4.5 mm.

[0020] To verify the performance of the hydrogen sensor in this invention, a hydrogen sensor from the background art was used as a comparative example, and the hydrogen sensor with the structure of Experimental Example 1 was used as an experimental example. The experimental example and the comparative example were placed on a test board and tested in a fume hood. First, air was introduced for 1 minute. After the output signal stabilized, 100 ppm H2 was introduced for 3 minutes. Finally, the H2 was removed after 4 minutes, and the curve returned to the baseline level when air was introduced. Figure 4In the diagram, lines 1 and 2 represent the response time curves of the hydrogen sensor in the experimental example, while lines 3 and 4 represent the response time curves of the hydrogen sensor in the comparative example. It is clearly evident that the response times T90 of the two sensors are significantly different, with lines 1 and 2 showing advantages in both T90 and recovery time T10 after gas withdrawal. This is particularly beneficial in industrial settings such as coal mines, where it can quickly detect leaked H2 from the air, enhancing safety and reliability. Furthermore, in the anti-interference experiment, the results are shown in the table below. It is evident that the CO interference performance of the hydrogen sensor in the experimental example is significantly better than that of the hydrogen sensor in the comparative example. When 50 ppm CO gas is introduced, the CO capture capability of the hydrogen sensor in the comparative example is 10 times that of the hydrogen sensor in the experimental example, as shown in Table 1.

[0021] Table 1

[0022] Experimental Example Comparative Example 50ppm CO display value 10ppm 100ppm

[0023] In the foregoing description of this specification, unless otherwise expressly specified and limited, the terms "fixed," "installed," "connected," or "joined" should be interpreted broadly. For example, the term "joined" can refer to 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 an indirect connection through an intermediate medium; or it can refer to the internal communication of two components or the interaction between two components. Therefore, unless otherwise expressly limited in this specification, those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0024] Based on the above description in this specification, those skilled in the art will also understand that the following terms used, such as "upper," "lower," "front," "rear," "left," "right," "length," "width," "thickness," "vertical," "horizontal," "top," "bottom," "inner," "outer," "axial," "radial," "circumferential," "center," "longitudinal," "transverse," "clockwise," or "counterclockwise," are terms indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings of this specification. They are only for the purpose of facilitating the explanation of the present invention and simplifying the description, and do not imply that the device or element involved must have the specific orientation, or be constructed and operated in a specific orientation. Therefore, the above-mentioned orientation or positional relationship terms should not be understood or interpreted as limitations on the present invention.

[0025] Furthermore, the terms "first" or "second," etc., used in this specification to refer to numbers or ordinal numbers are for descriptive purposes only and should not be construed as indicating, explicitly or implicitly, relative importance or specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this specification, "a plurality of" means at least two, such as two, three, or more, unless otherwise explicitly specified.

[0026] In other embodiments of this utility model, the diameter and length of the air inlet can also be selected within the above range.

Claims

1. A hydrogen sensor, comprising a housing and a top cover, characterized in that: The upper cover is provided with an air inlet hole that runs through the height of the upper cover. The air inlet hole is a microchannel with a diameter of 0.1-2.0 mm and a length of 1.5-4.5 mm. A working electrode is fixedly provided inside the housing on the inner side of the upper cover. The working electrode is positioned directly opposite the air inlet hole, so that the air entering the air inlet hole can diffuse directly to the working electrode.

2. The hydrogen sensor according to claim 1, characterized in that: The diameter of the air inlet is 0.5 mm and the length is 3.2 mm.

3. The hydrogen sensor according to claim 1 or 2, characterized in that: The outer side of the top cover is provided with a first groove with the opening facing upwards, and the air inlet of the air inlet is located on the bottom of the first groove.

4. The hydrogen sensor according to claim 1 or 2, characterized in that: The inner side of the top cover is provided with a second groove with the opening facing downwards. The air outlet of the air inlet is located on the bottom of the second groove. The second groove is for the installation of the filter layer, and the working electrode covers the filter layer.

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