Hydrogen sensor performance test system based on gas-induced color change material

Abstract

This utility model discloses a hydrogen sensor performance testing system based on gas-chromic materials, belonging to the field of sensor performance testing technology. The system mainly consists of an optical detection module, a gas mixing module, and a test chamber module. The optical detection module uses a fiber optic spectrometer to monitor the spectral characteristics changes of the gas-chromic material in a hydrogen environment in real time, achieving high-precision detection by establishing a quantitative relationship between hydrogen concentration and optical parameters. The gas mixing module can accurately prepare hydrogen mixtures of different concentrations and deliver them to the test chamber. The test chamber module adopts a standardized operating procedure and integrates vacuuming, gas replacement, and optical detection functions. This system effectively solves the problems of insufficient accuracy and poor efficiency in traditional electrochemical detection methods and is suitable for performance testing and calibration of various forms of gas-chromic materials.

Description

Technical Field

[0001] This utility model belongs to the field of sensor performance testing technology, specifically relating to a hydrogen sensor performance testing system based on gas-chromic materials. Background Technology

[0002] With the accelerated global energy structure transformation, hydrogen's strategic position as a zero-carbon clean energy source is becoming increasingly prominent. However, its explosive concentration limit of 4%-75% and its colorless and odorless characteristics make leak detection a core challenge for safe applications. Traditional hydrogen sensors mainly rely on electrochemical, thermal conductivity, or semiconductor principles, and generally suffer from the following inherent defects: electrochemical sensors require external circuitry and may cause sparks in flammable environments; semiconductor sensors are susceptible to interference from humidity, CO, etc., resulting in a high false alarm rate; the electrolyte in electrochemical sensors is prone to drying out, leading to a short average lifespan; and they are difficult to meet the safety monitoring needs of flammable and explosive scenarios.

[0003] Hydrogen-sensitive gas-chromic sensors are sensing elements that do not contain electronic components and rely solely on changes in the intrinsic optical properties of materials for detection. They possess advantages such as intrinsic safety (no power supply required) and resistance to electromagnetic interference. However, they face the challenge of a lack of performance evaluation systems. Existing technologies lack standardized measurement methods for key parameters such as response time and optical contrast, and most existing testing devices do not integrate environmental compensation modules. Furthermore, fluctuations in temperature and humidity can cause baseline drift in gas-chromic materials.

[0004] To address the issue of environmental interference, Chinese patent CN 219496293 U discloses a hydrogen sensor performance testing device. This device simulates different operating conditions through a temperature and humidity control module and employs an electrical signal triggering mechanism for performance evaluation: when the sensor output electrical signal reaches equilibrium, the control unit automatically adjusts the hydrogen concentration to complete the detection. While this solution solves the environmental interference problem, its detection mode, which relies on electrical signal triggering, suffers from insufficient accuracy. It cannot directly capture the changes in the optical spectral characteristics of gas-induced color-changing materials, making it difficult to quantify key parameters such as the response sensitivity and color-changing dynamics of optical sensors, thus hindering the accurate evaluation of optical sensing technology.

[0005] Therefore, there is an urgent need to develop a novel testing mode based on direct optical signal detection to overcome the insufficient accuracy of existing electrical signal detection mechanisms in evaluating the performance of gas-induced color-changing materials. Utility Model Content

[0006] To address the aforementioned problems, this utility model aims to provide a novel hydrogen sensor performance testing system. This system integrates vacuum purification and in-situ optical monitoring technologies, and establishes a standardized benchmark for evaluating the performance of gas-induced color-changing sensors by directly quantifying the spectral changes of materials in a hydrogen environment.

[0007] To achieve the above objectives, the technical solution adopted by this utility model is as follows: A hydrogen sensor performance testing system based on gas-chromic materials, comprising: a gas mixing module, used to dilute standard concentration hydrogen into a hydrogen mixture containing a preset hydrogen concentration and then deliver it to a test chamber module; the test chamber module, comprising: a top cover with a visualization quartz window; a testing stage for placing the material to be tested; a mixed gas inlet connected to the gas mixing module for introducing the hydrogen mixture; a vacuum interface connected to a vacuum pump; and a mixed gas outlet connected to an exhaust pipe for discharging the mixed gas; and an optical detection module, comprising: an optical fiber transmission unit, where a specific wavelength light signal emitted by a light source is transmitted through an optical fiber and illuminates the surface of the material to be tested through the visualization quartz window, while simultaneously receiving the reflected / transmitted light from the material; a spectral detection unit, where a spectrometer disperses the returned light signal and then digitizes it using a detector to output spectral data; and a data processing unit, where a terminal device analyzes the spectral data in real time using a matching algorithm, extracts optical parameters, and synchronously records dynamic changes.

[0008] Furthermore, the gas mixing module includes a gas mixing tank, a hydrogen source, and a dilution gas source;

[0009] The gas mixing tank is integrated into the main structure of the system and is connected to a hydrogen source and a dilution gas source through independent gas transport pipelines. Specifically, the gas transport pipeline connected to the hydrogen source is equipped with a hydrogen flow meter and hydrogen; the gas transport pipeline connected to the dilution gas source is equipped with a dilution gas flow meter and a dilution gas control valve. When the hydrogen / dilution gas flow rate reaches a preset threshold, the hydrogen control valve / dilution gas control valve is opened, allowing the two gases to be dynamically mixed in the gas mixing tank. An online hydrogen analyzer is installed in the gas mixing tank and is electrically connected to the control panel on the surface of the main structure.

[0010] Furthermore, the visualization quartz window is located in the center of the top cover, the top cover can be opened and closed, and the testing platform is located directly below the top cover.

[0011] Furthermore, the vacuum interface is connected to the vacuum pump through a pipeline configured with a vacuum pump control valve. The vacuum pump is located inside the main structure of the system and is controlled to start and stop via a vacuum pump switch. The operating status of the vacuum pump is displayed in real time by a working indicator light.

[0012] Furthermore, the mixed gas inlet is connected to the gas mixing tank through a gas guide pipe. A mixed gas control valve is installed on the gas guide pipe. When the mixed gas in the gas mixing tank reaches the set concentration, the mixed gas control valve is opened to allow the hydrogen mixed gas to enter the test chamber.

[0013] Furthermore, an air vent valve is installed on the vent pipeline.

[0014] Furthermore, the optical fiber is fixed on an optical fiber stage, which includes:

[0015] A horizontal support plate is used to fix optical fibers using the optical fiber holes opened on it;

[0016] The height-adjustable bracket allows for adjustment of the vertical height of the horizontal support plate.

[0017] Furthermore, the hydrogen flow meter, hydrogen control valve, dilution gas flow meter, dilution gas control valve, vacuum pump control valve, mixed gas control valve, vacuum pump switch, working indicator light, and vent valve are all located on the side wall of the main structure of the system.

[0018] The beneficial effects of this utility model are:

[0019] 1. The hydrogen sensor performance testing system based on gas-chromic materials disclosed in this application directly monitors the spectral characteristic changes of gas-chromic materials using optical fibers and spectrometers, establishes a quantitative correspondence between hydrogen concentration and optical parameters, and realizes high-sensitivity, high-precision direct optical detection, effectively overcoming the problem of indirect errors that may exist in traditional electrical signal detection;

[0020] 2. The test system disclosed in this application integrates a gas mixing module and a vacuum control unit, which can achieve rapid gradient switching within the range of 0-100% hydrogen concentration, making it convenient to simulate the hydrogen sensitivity of materials under different hydrogen concentrations;

[0021] 3. The testing system disclosed in this application adopts a modular testing chamber structure, which optimizes the process connection between vacuuming, gas replacement and optical detection. This not only improves testing efficiency but also avoids interference from other gases and improves the accuracy of the test results. Attached Figure Description

[0022] Figure 1 This is a left-side schematic diagram of a hydrogen sensor performance testing system based on gas-chromic materials.

[0023] Figure 2 This is a front view schematic diagram of a hydrogen sensor performance testing system based on gas-chromic materials.

[0024] Figure 3 A top-view schematic diagram of a hydrogen sensor performance testing system based on gas-chromic materials;

[0025] Among them, 1-main structure, 2-test cavity, 3-fiber optic station;

[0026] 11-Hydrogen flow meter, 12-Dilution gas flow meter, 13-Hydrogen control valve, 14-Dilution gas control valve, 15-Mixed gas control valve, 16-Vacuum pump control valve, 17-Vacuum pump switch, 18-Working indicator light.

[0027] 21-Visual quartz window, 22-Mixed gas inlet, 23-Vacuum port, 24-Mixed gas outlet;

[0028] 31-Height adjustable bracket, 32-Horizontal support plate, 33-Fiber optic port. Detailed Implementation

[0029] To enable those skilled in the art to better understand the technical solution of this utility model, the following description is provided in conjunction with the appendix. Figure 1-3 The technical solution of this utility model will be further described below.

[0030] It should be noted that the embodiments provided by this utility model are only for the purpose of effectively illustrating the technical features of this utility model. The locating terms such as left side, right side, upper end, and lower end are only for better describing the embodiments of this utility model and should not be regarded as a limitation on the technical solution of this utility model.

[0031] Example 1

[0032] This embodiment discloses a hydrogen sensor performance testing system based on gas-chromic materials. The system employs a modular design, with each component linked to a valve system via gas pipelines. For details, please refer to [reference needed]. Figure 1-3 .

[0033] The main structure 1 of the system integrates a gas mixing tank and a vacuum pump internally, and is externally connected to the test chamber 2 and the fiber optic station 3. Hydrogen and nitrogen sources (as dilution gases) are connected to the gas mixing tank via independent gas delivery pipelines. A hydrogen flow meter 11 and a hydrogen control valve 13 are installed on the gas delivery pipeline connecting the gas mixing tank and the hydrogen source, while a dilution gas flow meter 12 and a dilution gas control valve 14 are installed on the gas delivery pipeline connecting the gas mixing tank and the nitrogen source. After the flow rates of the hydrogen and nitrogen sources are precisely adjusted by the hydrogen flow meter 11 and the dilution gas flow meter 12, they are connected to the gas mixing tank by controlling the hydrogen control valve 13 and the dilution gas control valve 14. That is, when the flow meter reaches the preset concentration value, the hydrogen / dilution gas control valves 13 / 14 are simultaneously opened to dynamically mix the two gases in the gas mixing tank. The high-precision flow meter combination can achieve precise configuration of ppm-level hydrogen-nitrogen mixed gas.

[0034] The test chamber 2 is equipped with an openable top cover to facilitate the placement of the test material into the test chamber 2. The top cover has a centrally located visual quartz window 21 (transmission band 200~1100 nm). A test stage for placing the test material is fixedly installed inside the test chamber 2 and directly below the top cover. The side wall of the test chamber 2 is provided with a mixed gas inlet 22, a vacuum interface 23 and a mixed gas outlet 24 that are connected to the inside of the chamber. The gas mixing tank is connected to the mixed gas inlet 22 on the test chamber 2 through a gas guide pipe. A mixed gas control valve 15 is installed on the gas guide pipe. When the hydrogen percentage of the mixed gas in the gas mixing tank reaches the set value (the gas mixing tank is equipped with an online hydrogen analyzer to monitor the hydrogen concentration in the mixed gas in real time. The analyzer is electrically connected to the control panel (not shown in the figure) installed on the surface of the main structure 1 through electrical circuits, so that the operator can intuitively view and monitor the gas concentration data, thereby facilitating the smooth operation of subsequent operations; the model of the online hydrogen analyzer is not limited, and common online hydrogen concentration analyzers on the market are applicable), the mixed gas control valve 15 is opened, and the mixed gas enters the interior of the test chamber 2. The vacuum port 23 is connected to a vacuum pump via a pipeline, and a vacuum pump control valve 16 is installed on this pipeline (kept closed during testing). The vacuum pump is controlled to start and stop via a vacuum pump switch 17, and the working indicator light 18 on the main structure 1 displays the vacuum pump's operating status in real time. The mixed gas outlet 24 is connected to an venting pipeline to directly exhaust the mixed gas into the atmosphere. An venting valve (not shown in the figure) is installed on the venting pipeline.

[0035] The fiber optic station 3 consists of a height-adjustable bracket 31 and a horizontal support plate 32. The height-adjustable bracket 31 is fixed to the top of the main structure 1, and the horizontal support plate 32 is horizontally fixed to the height-adjustable bracket 31, thereby achieving vertical height adjustment (this solution does not limit the specific structure of the height-adjustable bracket 31; any bracket structure capable of vertically adjusting the support plate is applicable, and the configuration of the bracket does not affect the core technical features of this solution). Fiber optic holes 33 are provided on the horizontal support plate 32, located above the center of the top cover. Fiber optic cables used for optical detection are inserted into the fiber optic holes 33 for fixation.

[0036] In this embodiment, the optical detection module connects the spectrometer to the terminal device (computer) via optical fiber, forming a complete optical detection loop. During operation, a specific wavelength light signal emitted by the light source is transmitted through the optical fiber, illuminating the surface of the material under test through the visualization quartz window 21. After reflection / transmission from the material surface, the signal is transmitted back to the spectrometer via the optical fiber. The spectrometer disperses the returned light signal into spectral components of different wavelengths, which are then converted into photoelectric values ​​and digitized by a detector (such as a CCD / CMOS sensor), outputting digital spectral data to the terminal device. The accompanying APP analyzes the data in real time using a calibration algorithm, calculating optical parameters such as reflectivity and color difference. When the optical properties of the material under test change, the system immediately captures the change in the light signal, and the terminal synchronously analyzes and records the dynamic parameters, achieving continuous online monitoring of the material's optical properties and ensuring the accuracy of gas-induced color change detection.

[0037] The aforementioned hydrogen flow meter 11, dilution gas flow meter 12, hydrogen control valve 13, dilution gas control valve 14, mixed gas control valve 15, vacuum pump control valve 16, vacuum pump switch 17, working indicator light 18, and vent valve are all located on the side wall of the main structure for easy operation and control by testing personnel.

[0038] The operation process of this testing system is as follows:

[0039] 1) Sample loading: Open the closable top cover, place the material to be tested in the center of the testing platform, and close the top cover.

[0040] 2) System pre-vacuuming: Before testing, start the vacuum pump. At this time, the working indicator light 18 will light up. Then, sequentially open the hydrogen control valve 13, dilution gas control valve 14, mixed gas control valve 15, and vacuum pump control valve 16 to evacuate the gas flow pipeline, gas mixing tank, and the entire interior of the test chamber 2 to ≤10. -3 Pa, after processing is complete, close all valves;

[0041] 3) Mixed gas preparation: Open the pressure reducing valves of the hydrogen source (hydrogen cylinder) and nitrogen source (nitrogen cylinder), adjust the flow rate to the set value through the hydrogen flow meter 11 and the dilution gas flow meter 12, and then open the hydrogen control valve 13 and the dilution gas control valve 14 to allow hydrogen and nitrogen to flow into the gas mixing tank for dynamic mixing. During this process, keep the flow meter reading stable (<±2%) and monitor the hydrogen concentration in the mixed gas in real time (using an online hydrogen analyzer).

[0042] 4) Testing: When the hydrogen concentration in the mixed gas in the gas mixing tank reaches the set value, the mixed gas control valve 15 is opened to supply gas to the test chamber 2 (in the flowing hydrogen test mode, the hydrogen control valve 13 and the dilution gas control valve 14 are kept open; in the stable hydrogen test mode, the hydrogen control valve 13 and the dilution gas control valve 14 are closed). The hydrogen mixture reacts with the material under test. The specific wavelength light signal emitted by the light source is transmitted through the optical fiber and illuminates the material under test through the visualization quartz window 21. The reflected / transmitted light is transmitted back to the spectrometer through the optical fiber. The spectrometer disperses the light signal and then digitizes it through the detector, outputting spectral data to the terminal device. The accompanying APP analyzes and outputs optical parameters in real time and records dynamic changes synchronously.

[0043] 5) System Reset: After the test is completed, open the vent valve to release the residual gas in test chamber 2, then close the vent valve and repeat step 2).

[0044] As a preferred system option, the test chamber can integrate an environmental compensation module (including temperature and humidity control components) to study the impact of temperature and humidity changes on the detection performance of the hydrogen sensor. This module achieves environmental variable compensation analysis for hydrogen concentration detection by adjusting the temperature and humidity parameters within the chamber. The core protection content of this application does not involve the specific structure of the environmental compensation module, and therefore will not be elaborated upon. The temperature and humidity control of the test chamber can directly utilize existing, mature temperature and humidity control components for sensor performance testing.

[0045] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. However, the above description is only a specific embodiment of this utility model, and the technical features of this utility model are not limited thereto. Any other embodiments derived by those skilled in the art without departing from the technical solution of this utility model should be included within the scope of this utility model.

Claims

1. A hydrogen sensor performance testing system based on gas- chro ic materials, characterized in that, include: The gas mixing module is used to prepare hydrogen gas mixtures of different concentrations and deliver them to the test chamber module; The test chamber module includes: The top cover has a visual quartz window. The testing station is used to place the materials to be tested. The mixed gas inlet is connected to the gas mixing module and is used to introduce hydrogen mixed gas. Vacuum interface, for connecting to a vacuum pump; The gas mixture outlet is connected to the vent pipe and is used to discharge the gas mixture. Optical inspection module, including: The fiber optic transmission unit transmits a specific wavelength light signal emitted by the light source through an optical fiber, which illuminates the surface of the material under test through a visual quartz window, while simultaneously receiving the reflected / transmitted light back from the material. The spectral detection unit disperses the returned light signal from the spectrometer, then digitizes it using the detector to output spectral data. The data processing unit and terminal equipment analyze spectral data in real time using supporting algorithms, extract optical parameters, and record dynamic changes synchronously.

2. The hydrogen sensor performance test system based on gas- chromic material according to claim 1, wherein, The gas mixing module includes a gas mixing tank, a hydrogen source, and a dilution gas source; The gas mixing tank is integrated into the main structure of the system and is connected to the hydrogen source and dilution gas source through independent gas transport pipelines, wherein: A hydrogen flow meter and hydrogen gas are installed on the gas transport pipeline connected to the hydrogen source; A dilution gas flow meter and a dilution gas control valve are installed on the gas transport pipeline connected to the dilution gas source; When the hydrogen / dilution gas flow rate reaches the preset threshold, the hydrogen control valve / dilution gas control valve is opened to allow the two gases to be dynamically mixed in the gas mixing tank. An online hydrogen analyzer is installed inside the gas mixing tank, which is electrically connected to the control panel on the surface of the main structure.

3. The hydrogen sensor performance test system based on gas- chromic material according to claim 1, wherein, The visualization quartz window is located in the center of the top cover, which can be opened and closed, and the testing platform is located directly below the top cover.

4. The hydrogen sensor performance test system based on gas- chromic material according to claim 1, wherein, The vacuum interface is connected to the vacuum pump through a pipeline configured with a vacuum pump control valve. The vacuum pump is located inside the main structure of the system. The vacuum pump is controlled to start and stop via a vacuum pump switch, and the operating status of the vacuum pump is displayed in real time by a working indicator light.

5. The hydrogen sensor performance test system based on gas- chromic materials as claimed in claim 1, wherein, The mixed gas inlet is connected to the gas mixing tank through a gas guide pipe. A mixed gas control valve is installed on the gas guide pipe. When the mixed gas in the gas mixing tank reaches the set concentration, the mixed gas control valve is opened to allow the hydrogen mixed gas to enter the test chamber.

6. The hydrogen sensor performance test system based on gas- chromic materials as claimed in claim 1, wherein, An air vent valve is installed on the vent pipeline.

7. The hydrogen sensor performance test system based on gas- chromic materials as claimed in claim 1, wherein, The optical fiber is fixed on an optical fiber station, which includes: A horizontal support plate is used to fix optical fibers using the optical fiber holes opened on it; The height-adjustable bracket allows for adjustment of the vertical height of the horizontal support plate.

8. The hydrogen sensor performance test system based on gas- chromic material according to any one of claims 1 to 7, characterized in that The hydrogen flow meter, hydrogen control valve, dilution gas flow meter, dilution gas control valve, vacuum pump control valve, mixed gas control valve, vacuum pump switch, working indicator light, and vent valve are all located on the side wall of the main structure of the system.

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