Dangerous gas leakage monitoring system and method based on porous rotating wheel device

Abstract

The invention discloses a hazardous gas leakage monitoring system and method based on a porous rotating wheel device, and belongs to the technical field of hazardous gas leakage monitoring. The system comprises a multi-hole rotating wheel device, the multi-hole rotating wheel device comprises a disc-shaped rotating wheel, a rotating shaft is arranged in the center of the rotating wheel, a plurality of optical filter installation hole positions are evenly distributed in the rotating wheel, and the installation hole positions correspond to optical filters of different wave bands; the stepping motor is connected with a rotating shaft of the rotating wheel and used for driving the rotating wheel to rotate so as to switch the optical filters; the refrigerating device comprises a cylindrical chamber and a Stirling cryocooler, the cylindrical chamber seals the porous rotating wheel optical filter device, and the cylindrical chamber is provided with an incident window and an emergent window on the two sides of the porous rotating wheel device respectively; a refrigeration probe of the Stirling cryocooler is inserted into the closed cavity and is used for refrigerating incident infrared light; a medium wave infrared movement; and a control module. According to the invention, through switching of the plurality of optical filters, more VOCs gas leakage monitoring imaging is realized, the monitoring capability is improved, and the cost is reduced.

Description

Technical Field

[0001] The present invention belongs to the technical field of hazardous gas leakage monitoring, and relates to a hazardous gas leakage monitoring system and method based on a porous runner device. Background Art

[0002] Using an imaging module based on mid-wave infrared absorption technology to monitor the leakage of hazardous gases (mainly VOCs, volatile organic compounds) is a widely used monitoring method at present. VOCs gases contain thousands of substances, and the absorption peaks in their infrared absorption spectra are distributed in various bands of mid-wave infrared light.

[0003] CN111157479A discloses a spectroscopic infrared imaging monitoring device for VOC gas leakage, including: an infrared lens, an infrared spectroscopic element, a long-wave pass infrared filter, a first infrared focal plane detector, a second infrared focal plane detector, an infrared image processing module, and a display module; the infrared lens receives scene infrared radiation and outputs it to the infrared spectroscopic element; the infrared spectroscopic element outputs a first path of infrared radiation and a second path of infrared radiation, the first path of infrared radiation passes through the long-wave pass infrared filter and is output to the first infrared focal plane detector, and the second path of infrared radiation is output to the second infrared focal plane detector; the output ends of the first infrared focal plane detector and the second infrared focal plane detector are connected to the infrared image processing module; the cut-off edge of the long-wave pass infrared filter is at 3.3 - 3.7 μm.

[0004] CN113418887A discloses an imaging optical system for VOC gas emissions, including an infrared lens, an infrared spectroscopic element, a long-wave pass infrared filter, a first infrared focal plane detector, a second infrared focal plane detector, an infrared image processing module, and a display module, and further includes a condenser lens, which converges and intensifies the scene infrared radiation and outputs it to the infrared spectroscopic element.

[0005] Since the focal plane sensor of the mid-wave infrared module is very sensitive to infrared light noise, a narrow-band filter (generally with a span of 0.2 μm to 0.3 μm) must be used when monitoring gases to reduce the infrared light noise outside the absorption peak of the gas to be measured. Most of the mid-wave infrared modules for VOCs gas imaging on the market are built-in with band-pass filters of 3.2 μm to 3.5 μm, because this band can monitor the leakage of more VOC gases.

[0006] However, the actual monitoring requirements are for more types of VOCs gases. The traditional solutions can only disassemble the mid-wave infrared module to replace the filter, or deploy multiple mid-wave infrared modules. These two methods are costly and cannot meet the need for continuous monitoring. Therefore, there is an urgent need for a new hazardous gas leakage monitoring system and method that can achieve imaging monitoring of more VOCs gas leaks without disassembling the mid-wave infrared module to replace the filter or deploying multiple mid-wave infrared modules. Summary of the Invention

[0007] The object of the present invention is to provide a hazardous gas leakage monitoring system and method based on a porous wheel device, which can achieve imaging monitoring of more VOCs gas leaks without disassembling the mid-wave infrared module to replace the filter or deploying multiple mid-wave infrared modules. The object of the present invention is achieved through the following specific technical solutions.

[0008] The primary aspect of the present invention is to provide a hazardous gas leakage monitoring system based on a porous wheel device, comprising: A porous wheel device, including a disc-shaped wheel with a rotating shaft at the center of the wheel, and a plurality of filter mounting holes evenly distributed on the wheel, each mounting hole corresponding to a filter of a different wavelength band; A stepping motor, connected to the rotating shaft of the wheel, for driving the wheel to rotate to switch the filter; A refrigeration device, including a cylindrical chamber and a Stirling refrigerator. The cylindrical chamber seals the porous wheel filter device, and an incident window and an exit window are respectively provided on both sides of the porous wheel device. The refrigeration probe of the Stirling refrigerator is inserted into the sealed chamber for cooling the incident infrared light; A mid-wave infrared module for detecting and analyzing the infrared light spectrum emitted from the exit window; A control module for controlling the rotation direction and the number of steps of the stepping motor according to the target filter number.

[0009] The hazardous gas leakage monitoring system based on a porous wheel device provided by the present invention can accurately switch the filter according to the needs of the monitoring object through the design of the porous wheel device, the stepping motor and the control module, so as to meet the needs of monitoring more types of VOCs gas leaks.

[0010] Further, the wavelength band ranges of the plurality of filters are 3.0 - 5.0 μm, and the span between two adjacent wavelength bands in different wavelength bands is 0.1 - 0.3 μm. Such a wavelength band setting can cover a wider range of VOC gas absorption peaks, meet the monitoring requirements for a variety of different types of VOC gases, and greatly expand the monitoring range compared with the traditional single-wavelength band filter.

[0011] Furthermore, the filter mounting holes of the porous rotating wheel device fix the filter through an O-ring and a metal retaining ring. This fixing method not only ensures the stability of the filter during the rotation of the rotating wheel but also facilitates the installation and replacement of the filter, ensuring that the filter can accurately perform its filtering function under different working environments.

[0012] Furthermore, the cylindrical chamber includes a heat insulation pad and a sealant, and is filled with an inert gas to prevent water vapor condensation. The heat insulation pad can reduce the influence of external heat on the inside of the chamber, the sealant ensures the airtightness of the chamber, and filling with an inert gas effectively avoids the condensation of water vapor during the refrigeration process. These measures jointly ensure the stable operation of the refrigeration device, improve the effect of infrared light refrigeration, and thus enhance the performance of the entire monitoring system.

[0013] Furthermore, it also includes a reset baffle for calibrating the initial position of the rotating wheel; the reset baffle includes two telescopic stop pieces. Usually, the two stop pieces do not touch. When reset is required, the two stop pieces contact each other, and the rotating wheel is in the initial position. At this time, a filter with a fixed serial number (usually set as No. 1, or it can also be set as other serial numbers) is located in the coaxial optical path between the incident window and the exit window. During the long-term operation of the system, the stepping motor may experience position drift. The reset baffle can regularly calibrate the initial position of the rotating wheel to ensure the accuracy of the filter position during each monitoring and improve the reliability of the monitoring data.

[0014] Furthermore, the control module executes the following process: Calculate the stepping difference according to the target filter serial number and the current position serial number; Select the rotation direction of the motor to reach the target position along the shortest path; Drive the stepping motor to rotate the corresponding number of steps and update the current filter serial number.

[0015] Furthermore, the porous rotating wheel device is connected to the stepping motor through a Y-shaped elastic metal device, and the motor power supply line is sealed and fixed with glue.

[0016] Another aspect of the present invention is to provide a method for monitoring dangerous gas leakage. Based on the dangerous gas leakage monitoring system based on a porous rotating wheel device provided by the present invention, it includes the following steps: S1 Continuously cool the cylindrical chamber through a Stirling refrigerator; S2 Determine the filter serial number corresponding to the target gas type according to the target gas type; S3 Control the stepping motor to switch the filter and rotate the rotating wheel to the target filter position; S4 Use a mid-wave infrared camera module to perform imaging monitoring on gas leakage.

[0017] Further, the switching filter in step S3 includes: assuming that the porous rotating wheel device is in the initial state, the number of steps the motor needs to rotate when each filter rotates between the incident window and the exit window is established in sequence to form a basic data set M; according to the preset basic data set M, the step difference from the current filter to the target filter is calculated, and the forward or reverse rotation direction is selected.

[0018] Further, it also includes step S5 of regularly calibrating the initial position of the porous rotating wheel device through the reset baffle to eliminate position drift.

[0019] The present invention has the following beneficial technical effects: Through the filter switching of the porous rotating wheel device, multiple bands in the range of 3.0 μm to 5.0 μm can be covered, meeting the monitoring requirements of various VOC gases. The Stirling refrigerator cools the incident infrared light, effectively reducing thermal noise and improving the monitoring accuracy. There is no need to disassemble the mid-wave infrared core or deploy multiple cores, significantly reducing the equipment cost and maintenance cost. Through the cooperation of the stepping motor and the reset baffle, precise switching of the filter is achieved, ensuring the reliability of the monitoring. The cylindrical chamber is filled with inert gas to prevent water vapor condensation and adapt to complex working environments. Description of the Drawings

[0020] Figure 1 It is a schematic diagram of the main components of a hazardous gas leakage monitoring system based on a porous rotating wheel device.

[0021] Figure 2 It is a schematic diagram of the structure of the porous rotating wheel device.

[0022] Figure 3 It is a schematic diagram of the position calibration of the porous rotating wheel filter refrigeration device.

[0023] Figure 4 It is a schematic diagram of the stepping motor control process.

[0024] Figure 5 It is an infrared image of monitoring methane leakage using a filter of 3.2 μm to 3.4 μm.

[0025] Figure 6 It is an infrared image of monitoring acetylene leakage using a filter of 3.0 μm to 3.2 μm.

[0026] Reference numerals: 1 - front cover of cylindrical chamber, 2 - sealing ring of cylindrical chamber, 3 - porous runner device, 4 - rear cover of cylindrical chamber, 5 - Stirling refrigerator probe, 6 - opening, 7 - Y-shaped elastic metal device, 8 - incident window, 9 - exit window, 10 - front seat of motor connector, 11 - sealing ring of motor connector, 12 - heat insulation pad, 13 - stepping motor, 14 - rear cover of motor connector, 21 - first reset baffle, 22 - second reset baffle, 31 - filter mounting hole position, 32 - metal pressing ring, 33 - O-ring, 34 - filter. Detailed implementation mode

[0027] The technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the specification. Obviously, the described implementation modes are only a part of the implementation modes of the present invention, rather than all of them. All other implementation modes obtained by those of ordinary skill in the art based on the implementation modes of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0028] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be understood as a limitation of the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or quantity or position.

[0029] In the description of the present invention, it should be noted that unless otherwise clearly specified and limited, the terms "installation", "connection", 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 directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. Embodiment 1

[0030] A hazardous gas leakage monitoring system based on a porous runner device, the main components are as Figure 1As shown in the figure, a cylindrical chamber is used to seal the porous wheel device 3. A Stirling refrigerator is used for refrigeration, and a stepper motor 13 is used for driving to realize the rotation of the porous wheel device 3, so as to automatically switch multiple filters. The front cover 1 of the cylindrical chamber has thermal insulation material pasted inside, and the outer wall of the cover has threads. The rear cover 4 of the cylindrical chamber has thermal insulation material pasted inside, and the inside of the cover has threads. The cylindrical chamber sealing ring 2 is used for sealing when the front and rear covers are connected. The front cover 1 of the cylindrical chamber, the cylindrical chamber sealing ring 2, the porous wheel device 3 and the rear cover 4 of the cylindrical chamber can be fastened by threads to form a sealed chamber. The Stirling refrigerator probe 5 is inserted into the sealed chamber through the opening 6. The Y-shaped elastic metal device 7 is fixed at the center of the rear cover 4 of the cylindrical chamber, and is used to clamp the Stirling refrigerator probe 5 inserted into the chamber to increase the contact area of the probe, improve the refrigeration effect, and there are small holes at its bottom for fixing the motor shaft. During installation, after the Stirling refrigerator probe 5 is inserted into the sealed chamber, glue should be used for sealing. An incident window 8 is provided on the front cover 1 of the cylindrical chamber, and there is an infrared coating on the surface. The film material is germanium or silicon, and the infrared coating covers all the infrared bands allowed to pass through by the filters in the porous wheel device 3. An exit window 9 is provided on the rear cover 4 of the cylindrical chamber, and the coating on the surface is the same as that of the incident window 8 and is coaxial with the incident window 8. When the cylindrical chamber is installed on the mid-wave infrared core, the incident window 8 is aligned with the lens, and the exit window 9 is aligned with the core window. In order to reduce the influence of environmental heat, a sealing sleeve is used to connect between the exit window and the core window and is fixed with glue.

[0031] A motor connecting piece front seat 10 is welded on the cylindrical chamber, with threads on the outside and a small hole in the center; the motor connecting piece sealing ring 11 is an O-ring; the heat insulation pad 12 has a small hole in the middle for reducing the heat conduction of the motor to the cylindrical chamber; the motor connecting piece rear cover 14 is made of metal to facilitate the heat dissipation of the stepper motor 13. Its inner wall has threads and a motor fastening buckle. The threads are used to connect with the motor connecting piece front seat 10, and the fastening buckle is used to fix the motor. There are small holes at the rear for installing the motor power supply line. During connection, the motor connecting piece sealing ring 11 is fixed at the root of the motor connecting piece front seat 10, the heat insulation pad 12 is closely attached to the motor connecting piece front seat 10, the stepper motor 13 is inserted into the rear cover 4 of the cylindrical chamber through the small hole of the heat insulation pad 12 and passes through the rotating shaft of the porous wheel device 3, and finally is fixed into the small hole at the bottom of the Y-shaped elastic metal device 7. After the stepper motor 13 and the motor connecting piece front seat 10 are installed, glue should be used for sealing. After the power supply line of the motor connecting piece rear cover 14 is installed, glue should be used for sealing. In order to avoid the water vapor generated by refrigeration, the installation should be carried out in a dry environment, and an inert gas is filled into the cylindrical chamber.

[0032] The structure of the porous wheel device 3 is as Figure 2 shown Figure 2The left figure in the middle is the top view, and the right figure is the three-dimensional view. The porous rotating wheel filter device 3 is in the shape of a disc, with a rotating shaft at the center, and a number of filter mounting holes 31 are evenly distributed. The filter 34 is fixed on the filter mounting hole 31 through a metal pressing ring 32 and an O-ring 33. The wavelength ranges of multiple filters 34 are 3.0 - 5.0 μm, and the span between adjacent two wavelength bands in different wavelength bands is 0.1 - 0.3 μm.

[0033] The position calibration of the porous rotating wheel device 3 is as Figure 3 shown. A first reset baffle 21 is provided on the front cover 1 of the cylindrical chamber, and a second reset baffle 22 is provided on the porous rotating wheel device 3. When the two come into contact, the motor cannot rotate, and the porous rotating wheel device is in the initial position. At this time, the No. 1 filter is just located in the middle of the incident window and the exit window and is coaxial. In actual use, reset calibration is performed regularly to reduce the position drift caused after the motor has worked for a period of time. Due to the existence of the reset baffle, when the motor rotates to select a filter, it will automatically perform forward or reverse positioning of the target filter according to the number of steps.

[0034] The control process of the stepping motor 13 when the porous rotating wheel device 3 selects a target filter is as Figure 4 shown, and the steps are as follows.

[0035] (1) Determine the number corresponding to the required standard filter.

[0036] (2) Read the number of the filter at the current position.

[0037] (3) Determine the rotation direction of the motor, forward or reverse, according to the size of the numbers.

[0038] (4) Assume that when the porous rotating wheel device is in the initial state, sequentially establish the number of steps the motor needs to rotate when each filter rotates between the incident window and the exit window, and form a basic data set M. Calculate the step difference required to rotate from the current position to the target position according to the number difference and the basic data set M.

[0039] (5) Control the motor to run the corresponding step difference, rotate the target filter to the middle of the incident and exit windows, and make the three lenses coaxial.

[0040] (6) Record and save the number of the current filter for the next rotation. Embodiment 2

[0041] A method for monitoring dangerous gas leakage based on a porous rotating wheel device, using the dangerous gas leakage monitoring system of Embodiment 1, includes the following steps: S1 Continuously cool the cylindrical chamber through a Stirling cooler; S2 Determine the filter number corresponding to the target gas type according to the target gas type; S3 controls the stepper motor to switch the filter, and rotates the turntable to the target filter position; S4 uses the mid-wave infrared module to perform imaging monitoring on gas leakage; S5 regularly calibrates the initial position of the porous turntable device through the reset baffle to eliminate position drift.

[0042] When methane gas monitoring needs to be realized, rotate the turntable to select the filter with a wavelength range of 3.2 μm to 3.4 μm, and the monitoring results are as Figure 5 shown. When acetylene gas monitoring needs to be realized, rotate the turntable to select the filter with a wavelength range of 3.0 μm to 3.2 μm, and the monitoring results are as Figure 6 shown. In this way, according to the monitoring object, by rotating the turntable to select the filter with an appropriate wavelength band, leakage monitoring of various VOCs gases can be carried out, and leakage imaging can be obtained with clear imaging.

[0043] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention without departing from the principle and spirit of the present invention. The protection scope of the present invention is defined by the claims and their equivalent technical solutions.

Claims

1. A dangerous gas leakage monitoring system based on a porous wheel device, characterized in that: include: The multi-hole rotating wheel device comprises a disc-shaped rotating wheel, a rotating shaft is arranged at the center of the rotating wheel, and a plurality of filter installation holes are evenly distributed on the rotating wheel, and each installation hole corresponds to a filter of a different wavelength band; A stepper motor is connected to the rotating shaft of the rotating wheel and is used to drive the rotating wheel to rotate so as to switch the filter; The refrigeration device comprises a cylindrical chamber and a Stirling refrigerator, wherein the cylindrical chamber seals the porous wheel filter device, and the cylindrical chamber is provided with an incident window and an exit window on both sides of the porous wheel device; a refrigeration probe of the Stirling refrigerator is inserted into the sealed chamber to cool the incident infrared light; The medium-wave infrared movement is used to detect and analyze the infrared light spectrum emitted from the exit window; The control module controls the rotation direction and step number of the stepper motor according to the target filter number.

2. The hazardous gas leakage monitoring system according to claim 1, characterized in that: The wavelength range of the multiple filters is 3.0-5.0 μm, and the span between two adjacent wavelengths in different wavelengths is 0.1-0.3 μm.

3. The hazardous gas leakage monitoring system according to claim 1, characterized in that: The filter installation hole of the porous rotating wheel device fixes the filter through an O-ring and a metal pressure ring.

4. The hazardous gas leakage monitoring system according to claim 1, characterized in that: The columnar chamber comprises a heat insulating pad and a sealant, and is filled with an inert gas.

5. The hazardous gas leakage monitoring system according to claim 1, characterized in that: It also includes a reset baffle for calibrating the initial position of the rotating wheel; the reset baffle includes two telescopic baffles, when the two baffles are in contact with each other, the rotating wheel is in the initial position, at which time a fixed number filter is located in the coaxial optical path between the incident window and the exit window.

6. The hazardous gas leakage monitoring system according to claim 1, characterized in that: The control module performs the following process: Calculate the step difference based on the target filter number and the current position number; Select the direction of motor rotation to reach the target position in the shortest way; Drive the stepper motor to rotate the corresponding number of steps and update the current filter number.

7. The hazardous gas leakage monitoring system according to claim 1, characterized in that: The porous rotating wheel device is connected to the stepping motor through a Y-shaped elastic metal device, and the motor power supply circuit is sealed and fixed by glue.

8. A method for monitoring hazardous gas leakage based on the hazardous gas leakage monitoring system according to any one of claims 1 to 7, characterized in that: The following steps are involved: S1 continuously cools the cylindrical chamber using a Stirling refrigerator; S2 determines the filter number of the corresponding band according to the target gas type; S3 controls the stepper motor to switch the filter and rotates the wheel to the target filter position; The S4 uses a mid-wave infrared core to image and monitor gas leaks.

9. The method for monitoring dangerous gas leakage according to claim 8, characterized in that: The switching of filters in step S3 includes: assuming that the multi-hole rotating wheel device is in the initial state, sequentially establishing the number of steps that the motor needs to rotate when each filter rotates between the incident window and the exit window to form a basic data set M; based on the preset basic data set M, calculating the step difference from the current filter to the target filter, and selecting the forward or reverse direction.

10. The method for monitoring dangerous gas leakage according to claim 8, characterized in that: The method further comprises step S5 of regularly calibrating the initial position of the porous wheel device by resetting the baffle plate to eliminate position drift.

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