A gas leak detection device with optical and pressure compound monitoring

Abstract

The application discloses a gas leakage detection device for optical and pressure composite monitoring, which comprises a pipe shell, a pressure-sensitive core and a laser gas detection unit. One end of the pipe shell is open, and the pressure-sensitive core is sealedly installed at the opening of the pipe shell. A gas chamber is arranged in the pipe shell, and diffusion air holes communicating with the gas chamber are arranged on the pipe shell. The laser gas detection unit is located in the interior of the other end of the pipe shell. The region of the pressure-sensitive core opposite to the laser gas detection unit is provided with a reflecting layer, and the inner wall of the gas chamber and the reflecting layer on the pressure-sensitive core are used for reflecting the laser emitted by the laser gas detection unit. The application has the advantages of simple structure, accurate and rapid leakage detection and the like.

Description

Technical Field

[0001] This invention relates to the field of gas leak detection technology, specifically to a gas leak detection device that combines optical and pressure monitoring. Background Technology

[0002] Pressure sensors are used to detect leaks. Their ability to measure gas pressure allows for rapid detection of leaks, making them widely used in leak detection. For example, in the automotive industry, pressure sensors detect tire leaks; in air conditioning and refrigeration, they detect leaks in refrigeration systems; and in the chemical and petroleum industries, they detect leaks in pipelines and equipment. However, ordinary pressure sensors struggle to accurately detect minute leaks in pressure vessels. For instance, in high-pressure hazardous gas storage tanks, a slight leak may not cause a significant pressure change, and the resulting pressure variation is insufficient for the resolution of the pressure sensor, rendering it unable to provide monitoring and alarm functions. Furthermore, pressure changes due to temperature variations can also lead to false alarms. These are drawbacks of indirectly detecting leaks through pressure.

[0003] Tunable Semiconductor Laser Absorption Spectroscopy (TDLAS) is a laser monitoring technology that measures gas concentration by utilizing the principle that laser energy is selectively absorbed by gas molecules to form an absorption spectrum. Specifically, when the wavelength of the laser passing through the gas being measured matches the center frequency of a certain absorption line of the gas, photons of that frequency are absorbed, causing the laser intensity to attenuate. The degree of attenuation is proportional to the concentration of the gas being measured, following the Lambert-Beer law. Therefore, the gas concentration can be measured by measuring the attenuation of the laser intensity. However, laser gas sensing requires waiting for the gas to diffuse into the gas chamber before detection, resulting in a lag in leak alarm time.

[0004] Therefore, in summary, conventional pressure sensors cannot monitor minute leaks in gas containers; pressure sensors may issue false alarms for leaks caused by pressure changes due to temperature variations; and laser gas sensing methods have a time lag in leak alarms. Summary of the Invention

[0005] To address the technical problems existing in the prior art, the present invention provides a gas leak detection device that combines optical and pressure monitoring, which is simple in structure and provides accurate and rapid leak detection.

[0006] To solve the above-mentioned technical problems, the technical solution proposed by this invention is as follows:

[0007] A gas leak detection device combining optical and pressure monitoring includes a casing, a pressure-sensitive core, and a laser gas detection unit. One end of the casing is open, and the pressure-sensitive core is sealed and installed at the opening of the casing. A gas chamber is provided inside the casing, and a diffusion vent communicating with the gas chamber is provided on the casing. The laser gas detection unit is located inside the other end of the casing. A reflective layer is provided on the area of ​​the pressure-sensitive core facing the laser gas detection unit, and the inner wall of the gas chamber and the reflective layer on the pressure-sensitive core are used to reflect the laser emitted by the laser gas detection unit.

[0008] As a further improvement to the above technical solution:

[0009] A concave reflector is provided inside the other end of the tube.

[0010] The pressure-sensitive core surface is coated with a high-reflectivity film layer at other locations outside the pressure-sensitive film area to serve as a reflective layer.

[0011] The pressure-sensitive core is sealed and welded to the opening of the tube shell.

[0012] The diffusion pores are metal filter pores, ceramic filter pores, or semi-permeable membrane filter pores.

[0013] The tube shell has a first circuit board at one end and a second circuit board at the other end.

[0014] The first circuit board and the second circuit board are connected by conductive pillars.

[0015] The conductive pillar is a copper pillar.

[0016] The other end of the tube is provided with a cable, which is connected to the second circuit board.

[0017] The laser gas detection unit includes a laser and a detector.

[0018] Compared with the prior art, the advantages of the present invention are as follows:

[0019] This invention integrates a pressure sensor for indirect, rapid leak detection and a laser gas sensor for direct, precise leak detection. This combined optical and pressure monitoring, with both sensors complementing each other, significantly improves the safety of high-risk gas storage platforms, enabling timely early warning and enhancing the speed and accuracy of leak detection. Furthermore, this invention features a simple and compact structure, composed of small components, allowing for ultra-miniature packaging. Attached Figure Description

[0020] Figure 1 This is a structural diagram of the gas leak detection device of the present invention in an embodiment.

[0021] Legend: 1. Tube shell; 2. Pressure-sensitive core; 3. First circuit board; 4. Copper pillar; 5. Diffuser vent; 6. Second circuit board; 7. Cable; 8. Laser gas detection unit; 9. Concave reflector; 10. Gas chamber. Detailed Implementation

[0022] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0023] like Figure 1 As shown, the gas leak detection device for optical and pressure composite monitoring according to an embodiment of the present invention includes a shell 1, a pressure-sensitive core 2, and a laser gas detection unit 8; one end of the shell 1 is open, and the pressure-sensitive core 2 is sealed and installed at the opening of the shell 1; a gas chamber 10 is provided inside the shell 1, and a diffusion vent 5 communicating with the gas chamber 10 is provided on the shell 1; the laser gas detection unit 8 is located inside the other end of the shell 1; a reflective layer is provided in the area of ​​the pressure-sensitive core 2 facing the laser gas detection unit 8, and the inner wall of the gas chamber 10 and the reflective layer on the pressure-sensitive core 2 are used to reflect the laser emitted by the laser gas detection unit 8.

[0024] Specifically, the pressure-sensitive core 2 is a metal alloy thin-film pressure-sensitive core, but its special feature is that other areas on the surface of the pressure-sensitive core 2 outside the pressure-sensitive film area are coated with a high-reflectivity film layer, which can be used as a reflector. Of course, in other embodiments, a reflector arrangement can also be adopted. In addition, the pressure-sensitive core 2 is welded to the shell 1, which has extremely high sealing performance.

[0025] Specifically, a concave reflector 9 is provided inside the other end of the tube shell 1. The high reflectivity film on the pressure-sensitive core 2 and the concave reflector 9 are used together to reflect the laser emitted by the laser gas detection unit 8. The gas chamber 10 formed by the concave reflector 9, the reflective surface of the pressure-sensitive core 2, and the tube shell 1 is a Herriot absorption cell. The laser is reflected multiple times in the gas chamber 10, which extends the absorption optical path and ensures high-precision detection performance.

[0026] Specifically, the inner end of the tube shell 1 is provided with a first circuit board 3 and the other end is provided with a second circuit board 6. The relative positions of the first circuit board 3, the second circuit board 6 and the concave reflector 9 are fixed by a copper pillar 4. At the same time, the copper pillar 4 acts as a conductor to transmit electrical signals between the first circuit board 3 and the second circuit board 6. In addition, the other end of the tube shell 1 is provided with a cable 7, which is electrically connected to the second circuit board 6.

[0027] Specifically, the laser and detector in the laser gas detection unit 8 can be combined according to the types of hazardous gases actually being monitored. The laser and detector types are selected with reference to the molecular fingerprint spectrum. For example, for common hazardous gases such as ammonia, methane, ethane, carbon monoxide, and nitrogen monoxide, lasers and infrared detectors in the corresponding bands of 2um to 5um are used.

[0028] Specifically, the diffuser pores 5 include, but are not limited to, a filter screen, which has filter pores made of filter materials such as metal, ceramic, or semi-permeable membrane.

[0029] Working process: The casing 1 is installed on the gas storage platform and connected to a high-pressure hazardous gas source. The pressure of the gas is measured by the pressure-sensitive core 2. The pressure signal is connected to the second circuit board 6 through the first circuit board 3 and the copper pillar 4, and finally read out through the cable 7. The change in gas pressure is used to determine whether there is a gas leak. At the same time, when there is a leaking hazardous gas in the gas storage environment, the leaking gas enters the gas chamber 10 through the diffuser vent 5. The laser emitted by the laser gas detection unit 8 is absorbed by the hazardous gas. After being reflected multiple times by the concave reflector 9 and the coated reflective surface of the pressure-sensitive core 2, the absorbed and attenuated laser is received again by the laser gas detection unit 8. The concentration of the gas being measured is measured by the Lambert-Beer theorem. The ambient gas information is exported and collected through the cable 7 to achieve the purpose of alarm monitoring.

[0030] When applied to methane cylinders, the housing 1 is installed at the cylinder opening, and the pressure-sensitive core 2 directly monitors changes in methane pressure inside the cylinder. These pressure changes indicate potential gas leaks, serving as an early warning system. Simultaneously, the laser in the laser gas detection unit 8 uses a 1653.7nm wavelength laser, which exhibits significant absorption in methane gas. The pressure-sensitive core 2 is coated with a gold-ringed reflector, providing high reflectivity at 1653.7nm. The reflective area of ​​the pressure-sensitive core 2, along with the concave reflector 9 and the gas chamber 10, forms a Herriot absorption cell. The laser passes through the methane gas multiple times within the absorption cell before being detected and analyzed. This optical method enables effective detection of methane gas in the external environment of the cylinder. If the monitored concentration exceeds a specified value, an alarm is triggered.

[0031] This invention integrates a pressure sensor for indirect, rapid leak detection and a laser gas sensor for direct, precise leak detection. This combined optical and pressure monitoring, with both sensors complementing each other, significantly improves the safety of high-risk gas storage platforms, enabling timely early warning and enhancing the speed and accuracy of leak detection and alarm. Furthermore, this invention features a simple and compact structure, composed of small components, allowing for ultra-miniature packaging.

[0032] In the description of this invention, it should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0033] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0034] In this invention, unless otherwise explicitly specified and limited, the terms "assembly," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0035] The above are merely preferred embodiments of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principles of the present invention should be considered within the scope of protection of the present invention.

Claims

1. A gas leak detection apparatus for optical and pressure compound monitoring, characterized by, The application relates to a laser gas detection device, which comprises a tube shell (1), a pressure-sensitive core (2) and a laser gas detection unit (8); one end of the tube shell (1) is open, the pressure-sensitive core (2) is sealedly installed at the open end of the tube shell (1); an air chamber (10) is arranged in the tube shell (1), diffusion air holes (5) are arranged on the tube shell (1) and communicate with the air chamber (10); the laser gas detection unit (8) is arranged in the other end of the tube shell (1); a reflecting layer is arranged on the pressure-sensitive core (2) opposite to the region of the laser gas detection unit (8); and the inner wall of the air chamber (10) and the reflecting layer on the pressure-sensitive core (2) are used for reflecting the laser emitted by the laser gas detection unit (8).

2. The optical and pressure compound monitoring gas leak detection apparatus of claim 1, wherein, The other end of the tube shell (1) is internally provided with a concave mirror (9).

3. The optical and pressure compound monitored gas leak detection apparatus of claim 1, wherein, The pressure-sensitive core (2) is coated with a high-reflectivity film layer as the reflecting layer at positions other than the pressure-sensing film region on the surface of the pressure-sensitive core (2).

4. The optical and pressure composite monitoring gas leak detection apparatus according to claim 1 or 2 or 3, characterized in that, The pressure-sensitive core (2) is sealedly welded at the open end of the tube shell (1).

5. The optical and pressure compound monitoring gas leak detection apparatus according to claim 1 or 2 or 3, wherein, The diffusion air holes (5) are metal filter air holes, ceramic filter air holes or semi-permeable membrane filter air holes.

6. The optical and pressure composite monitoring gas leak detection apparatus of claim 1 or 2 or 3, wherein, The inside of the tube shell (1) is internally provided with a first circuit board (3) at one end and a second circuit board (6) at the other end.

7. The optical and pressure compound monitored gas leak detection apparatus of claim 6, wherein, The first circuit board (3) and the second circuit board (6) are connected through a conductive column.

8. The optical and pressure compound monitored gas leak detection apparatus of claim 7, wherein, The conductive column is a copper column (4).

9. The optical and pressure compound monitored gas leak detection apparatus of claim 6, wherein, The other end of the tube shell (1) is provided with an electric cable (7), and the electric cable (7) is connected with the second circuit board (6).

10. The optical and pressure compound monitoring gas leak detection apparatus according to claim 1 or 2 or 3, wherein, The laser gas detection unit (8) comprises a laser and a detector.

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