Airtight door airtightness detection device based on infrared thermal imaging

Abstract

The utility model relates to the field of airtightness detection, in particular to an airtight door airtightness detection device based on infrared thermal imaging, which comprises a sealing cover which covers a door frame wall and is fixed with the door frame wall in an adsorption manner, and a negative pressure type sealing cavity is defined by the sealing cover, the door frame wall and an airtight door on the door frame wall. The sealing cavity is subjected to air exhaust and pressure reduction through a negative pressure source, and a micromanometer for air pressure monitoring is connected in the sealing cavity; an infrared thermal imager located in the sealing cavity is installed on the sealing cover, and the detection range of the infrared thermal imager covers the gap area between the airtight door and the door frame wall. According to the utility model, the air tightness detection time of the air-tight door of the civil air defense space is greatly shortened, and the leakage points of the air-tight door can be accurately checked.

Description

Technical Field

[0001] This utility model relates to the field of airtightness detection, specifically a device for detecting the airtightness of a sealed door based on infrared thermal imaging. Background Technology

[0002] The airtightness of the sealed doors in civil defense spaces is of paramount importance. In wartime, they can prevent the infiltration of toxic gases and block the overpressure of shock waves. Therefore, during the construction phase, it is necessary to test and verify the airtightness of the sealed doors to ensure that the leakage rate meets national standards under a pressure difference of 50Pa.

[0003] The current standard testing method for the airtightness of airtight doors in civil defense spaces is positive pressure testing. During the test, the airtight door is first closed and locked to ensure that the sealing strip on the airtight door is evenly pressurized. Air is injected into the civil defense space through the test interface reserved in the civil defense space (or temporary drilling hole) and pressurized to the set value. After stabilization, the initial pressure is recorded. The pressure is maintained for 5 to 10 minutes, and the pressure drop is observed to see if it meets the standard.

[0004] This positive pressure testing method has the following problems: 1. Due to the extremely large size of the air-raid shelter, a long time needs to be reserved before testing to pressurize the air-raid shelter and bring it to the set pressure value, which takes a very long time; 2. During the testing phase, even if an abnormal pressure drop is detected in the air-raid shelter, since air-raid shelters are usually equipped with multiple sets of airtight doors, it is impossible to determine which airtight door or which area has a problem with airtightness, making it impossible to conduct an accurate investigation. Therefore, this problem urgently needs to be solved. Utility Model Content

[0005] To avoid and overcome the technical problems existing in the prior art, this utility model provides an airtightness detection device for sealed doors based on infrared thermal imaging. This utility model significantly shortens the airtightness detection time of sealed doors in air-raid shelters and can accurately identify leakage points of sealed doors.

[0006] To achieve the above objectives, this utility model provides the following technical solution:

[0007] An infrared thermal imaging-based airtightness detection device for a sealed door includes a sealing cover that is attached to and fixed to a door frame wall by adsorption. The sealing cover, the door frame wall, and the sealed door on the door frame wall enclose a negative pressure sealed cavity. The sealed cavity is depressurized by a negative pressure source, and a micro-manometer for air pressure monitoring is connected inside the sealed cavity. An infrared thermal imager located inside the sealed cavity is installed on the sealing cover, and the detection range of the infrared thermal imager covers the gap area between the sealed door and the door frame wall.

[0008] As a further embodiment of this utility model: a sealing strip is provided at the contact surface between the sealing cover and the door frame wall. The sealing strip includes an outer sealing strip and an inner sealing strip located in the inner ring of the outer sealing strip. The outer sealing strip and the inner sealing strip enclose a negative pressure cavity, which is connected to a vacuum pump through a negative pressure connector on the sealing cover.

[0009] As a further improvement of this utility model, multiple sets of infrared thermal imagers are arranged, and the detection ranges of each infrared thermal imager overlap to cover the gap area between the sealed door and the door frame wall.

[0010] As a further improvement of this utility model: an infrared thermal imager is provided, and a power source for driving the infrared thermal imager to rotate is provided on the sealing cover. The rotation axis of the power source is perpendicular to the door body of the airtight door, and the detection range of the infrared thermal imager when it rotates covers the gap area between the airtight door and the door frame wall.

[0011] As a further embodiment of this utility model: the power source includes a bearing seat fixed on one side of the sealing cover adjacent to the airtight door, a rotating shaft arranged perpendicular to the airtight door is mounted on the bearing seat, and an inner magnet is arranged radially on the rotating shaft, with the infrared thermal imager fixed on the inner magnet; an adjusting handwheel arranged coaxially with the bearing seat is rotatably mounted on the side of the sealing cover away from the airtight door, and an outer magnet that magnetically engages with the inner magnet is fixed on the adjusting handwheel, and the infrared thermal imager rotates synchronously with the adjusting handwheel due to the magnetic attraction of the inner magnet and the outer magnet.

[0012] As a further improvement of this utility model, the rotating shaft, bearing seat, and adjusting handwheel are all made of non-magnetic materials.

[0013] As a further improvement of this utility model: a gas source pipe connected to a negative pressure source is pre-embedded on the sealing cover, and a gas source regulating valve, a pressure gauge, a flow regulating valve and a flow meter are sequentially arranged on the gas source pipe along the suction direction of the gas source pipe; a pressure measuring tube connected to a micro pressure gauge is pre-embedded on the sealing cover.

[0014] Compared with the prior art, the beneficial effects of this utility model are:

[0015] 1. This utility model, through the cooperation of a sealing cover, door frame wall, and airtight door, forms a narrow sealed cavity. By evacuating and depressurizing the air inside the sealed cavity, a negative pressure sealed environment can be quickly formed in a short time, eliminating the need for prolonged inflation of the air-raid shelter and significantly shortening the airtightness testing time. When gas in the air-raid shelter leaks into the sealed cavity through the gaps in the airtight door under the action of pressure difference, the gas expands instantaneously and does work. Under the Joule-Thomson effect, the local temperature of the leakage area drops. By placing an infrared thermal imager inside the sealed cavity and observing the temperature gradient in the door gap area in the infrared image, the leakage area can be quickly identified, and the leakage point of the airtight door can be accurately located. The leakage amount per unit time can be calculated based on the readings of the micro-manometer and the flow meter, thereby determining whether the airtightness standard is met.

[0016] 2. The outer sealing strip and the inner sealing strip of this utility model form a negative pressure cavity structure. The negative pressure is generated by active suction by a vacuum pump, which enhances the sealing pressure between the sealing cover and the door frame wall and prevents the gas in the sealing cavity from leaking from the sealing strip, thus affecting the measurement accuracy of airtightness.

[0017] 3. This utility model achieves temperature field imaging of the sealed door gap area without blind spots by setting up multiple sets of infrared thermal imagers or setting up a single set of infrared thermal imagers for rotating scanning, and accurately locates the leakage point. When only one set of infrared thermal imagers is set up, the magnetic attraction synchronous transmission between the inner and outer magnets is adopted, and the angle of the infrared thermal imager can be adjusted without physically penetrating the sealing cover. This avoids the risk of shaft seal leakage caused by the rotating shaft directly penetrating the sealing cover, reduces the leakage on the sealing cover, and further improves the measurement accuracy of airtightness.

[0018] 4. The gas source pipe and pressure measuring pipe of this utility model are pre-embedded in the sealing cover, which is an integrated design that avoids the installation of pipe interfaces and further reduces the risk of leakage on the sealing cover. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of this utility model.

[0020] In the picture:

[0021] 1. Airtight door; 2. Door frame wall;

[0022] 3. Infrared thermal imager; 31. Bearing housing; 32. Rotating shaft;

[0023] 33. Inner magnet; 34. Adjustment handwheel; 35. Outer magnet;

[0024] 4. Negative pressure source; 41. Air source regulating valve; 42. Pressure gauge;

[0025] 43. Flow regulating valve; 44. Flow meter; 45. Gas source pipeline;

[0026] 5. Micromanometer; 51. Pressure measuring tube; 6. Sealing cover; 61. Sealing strip; 62. Negative pressure connector. Detailed Implementation

[0027] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0028] Please see Figure 1 In this embodiment of the utility model, a sealed door airtightness detection device based on infrared thermal imaging is provided. The sealed door 1 is fixed on the door frame wall 2. During the detection, a sealing cover 6 corresponding to the outer ring shape of the door frame wall 2 is placed on the door frame wall 2, so that the door frame wall 2 and the sealing cover 6 form a negative pressure sealing cavity.

[0029] The sealing cover 6 and the door frame wall 2 are sealed by a sealing strip 61. The sealing strip 61 includes an outer sealing strip and an inner sealing strip that is proportionally reduced in size within the inner ring of the outer sealing strip. The outer and inner sealing strips enclose a negative pressure cavity, which is connected to a vacuum pump through a negative pressure connector 62 on the sealing cover 6. After the sealing cover 6 is fixed, the negative pressure cavity is evacuated to a negative pressure state through the negative pressure connector 62, thereby achieving the adsorption-type fixation of the sealing cover 6. The negative pressure cavity and the sealing cavity can be evacuated sequentially by the vacuum pump.

[0030] The sealing cover 6 is made of cast epoxy resin or carbon fiber reinforced polymer and other non-magnetic materials. During casting, the gas source pipe 45 and pressure measuring pipe 51 are pre-embedded within the sealing cover 6. This pre-embedded arrangement prevents leaks caused by gaps between the pipes and the sealing cover 6. The gas source pipe 45 is connected to a negative pressure source 4, preferably a vacuum pump. The pressure measuring pipe 51 is connected to a micro-manometer 5, which measures the gas pressure inside the sealed cavity. Gas is drawn into the sealed cavity through the gas source pipe 45 to reduce the pressure. Along the suction direction of the gas source pipe 45, a gas source regulating valve 41, a pressure gauge 42, a flow regulating valve 43, and a flow meter 44 are sequentially installed on the gas source pipe 45.

[0031] During the airtightness test, an infrared thermal imager 3 is installed inside the sealed cavity. Under the Joule-Thomson effect, the local temperature in the leakage area decreases. The leakage amount is observed by monitoring the temperature gradient in the door seam area in the infrared image. Multiple sets of infrared thermal imagers 3 can be set up and cross-set to cover the gap area of ​​the sealed door 1.

[0032] To reduce setup costs, this embodiment uses only a single infrared thermal imager 3. The infrared thermal imager 3 covers the gap area of ​​the sealed door 1 when rotated. To drive its rotation, mounting holes are pre-drilled during casting for fixing the adjusting handwheel 34 and bearing seat 31. A rotating shaft 32, arranged perpendicular to the sealed door 1, is mounted on the bearing seat 31. An inner magnet 33 is radially mounted on the rotating shaft 32, and the infrared thermal imager 3 is fixed to the inner magnet 33. An adjusting handwheel 34, coaxially arranged with the bearing seat 31, is rotatably mounted on the side of the sealing cover 6 away from the sealed door 1. An outer magnet 35, magnetically attracted to the inner magnet 33, is fixed on the adjusting handwheel 34. The infrared thermal imager 3 rotates synchronously with the adjusting handwheel 34 due to the magnetic attraction of the inner magnet 33 and the outer magnet 35. The bearing seat 31, its bearing, the adjusting handwheel 34, and the rotating shaft 32 can all be made of ceramic material to avoid the influence of the magnets. External personnel can manually rotate the adjustment handwheel 34 to drive the infrared thermal imager 3 to rotate 360 ​​degrees, forming a detection without blind spots.

[0033] The basic principles of this application have been described above with reference to specific embodiments. However, it should be noted that the advantages, benefits, and effects mentioned in this application are merely examples and not limitations, and should not be considered as essential features of each embodiment of this application. Furthermore, the specific details disclosed above are for illustrative and facilitative purposes only, and are not limitations. These details do not limit the application to the necessity of employing the aforementioned specific details for implementation.

[0034] The block diagrams of devices, apparatuses, devices, and systems involved in this application are merely illustrative examples and are not intended to require or imply that they must be connected, arranged, or configured in the manner shown in the block diagrams. As those skilled in the art will recognize, these devices, apparatuses, devices, and systems can be connected, arranged, and configured in any manner. Words such as “comprising,” “including,” “having,” etc., are open-ended terms meaning “including but not limited to,” and are used interchangeably with them. The terms “or” and “and” as used herein refer to the terms “and / or,” and are used interchangeably with them unless the context clearly indicates otherwise. The term “such as” as used herein refers to the phrase “such as but not limited to,” and is used interchangeably with it.

Claims

1. A device for detecting the airtightness of a sealed door based on infrared thermal imaging, characterized in that, The system includes a sealing cover (6) that is mounted on and attached to the door frame wall (2). The sealing cover (6), the door frame wall (2), and the airtight door (1) on the door frame wall (2) form a negative pressure sealed cavity. The sealed cavity is evacuated and depressurized by a negative pressure source (4). A micro pressure gauge (5) for air pressure monitoring is connected inside the sealed cavity. An infrared thermal imager (3) is installed on the sealing cover (6) and located inside the sealed cavity. The detection range of the infrared thermal imager (3) covers the gap area between the airtight door (1) and the door frame wall (2).

2. The airtightness detection device for a sealed door based on infrared thermal imaging according to claim 1, characterized in that, A sealing strip (61) is provided at the contact surface between the sealing cover (6) and the door frame wall (2). The sealing strip (61) includes an outer sealing strip and an inner sealing strip located in the inner ring of the outer sealing strip. The outer sealing strip and the inner sealing strip enclose a negative pressure cavity, which is connected to the vacuum pump through the negative pressure connector (62) on the sealing cover (6).

3. A device for detecting the airtightness of a sealed door based on infrared thermal imaging according to claim 1 or 2, characterized in that, Multiple sets of infrared thermal imagers (3) are arranged, and the detection range of each infrared thermal imager (3) overlaps to cover the gap area between the sealed door (1) and the door frame wall (2).

4. A sealed door airtightness detection device based on infrared thermal imaging according to claim 1 or 2, characterized in that, An infrared thermal imager (3) is provided, and a power source for driving the infrared thermal imager (3) to rotate is provided on the sealing cover (6). The rotation axis of the power source is perpendicular to the door body of the sealed door (1). The detection range of the infrared thermal imager (3) when it rotates covers the gap area between the sealed door (1) and the door frame wall (2).

5. The airtightness detection device for a sealed door based on infrared thermal imaging according to claim 4, characterized in that, The power source includes a bearing seat (31) fixed on one side of the sealing cover (6) adjacent to the airtight door (1). A rotating shaft (32) arranged in the direction perpendicular to the airtight door (1) is installed on the bearing seat (31). An inner magnet (33) is arranged radially on the rotating shaft (32). The infrared thermal imager (3) is fixed on the inner magnet (33). An adjusting handwheel (34) arranged coaxially with the bearing seat (31) is rotatably installed on the side of the sealing cover (6) away from the airtight door (1). An outer magnet (35) that magnetically engages with the inner magnet (33) is fixed on the adjusting handwheel (34). The infrared thermal imager (3) is attracted by the magnetic attraction of the inner magnet (33) and the outer magnet (35) and rotates synchronously with the adjusting handwheel (34).

6. The airtightness detection device for a sealed door based on infrared thermal imaging according to claim 5, characterized in that, The rotating shaft (32), bearing housing (31) and adjusting handwheel (34) are all made of non-magnetic materials.

7. A sealed door airtightness detection device based on infrared thermal imaging according to claim 1 or 2, characterized in that, A gas source pipe (45) connected to the negative pressure source (4) is pre-embedded on the sealing cover (6). Along the suction direction of the gas source pipe (45), a gas source regulating valve (41), a pressure gauge (42), a flow regulating valve (43) and a flow meter (44) are sequentially installed on the gas source pipe (45); a pressure measuring tube (51) connected to the micro pressure gauge (5) is pre-embedded on the sealing cover (6).

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