Gas leakage alarm device for detecting pressure fluctuation at tail end of pipeline

Abstract

The invention discloses a pipeline tail end pressure fluctuation detection gas leakage alarm device, which relates to the technical field of gas leakage alarm, and comprises a gas pipeline, a flange end, a detachable sealing sleeve and a compression seat, the detection alarm unit is mounted on the outer wall of the compression seat; the fuel gas compression unit is arranged in the compression seat and used for compressing fuel gas leaked from the abutting face of the two flange ends, and the compressed fuel gas is detected through the detection alarm unit. The fuel gas compression unit compresses fuel gas leaked from the fuel gas pipeline, so that the concentration of the leaked fuel gas is increased at the initial stage of leakage, the detection alarm unit detects the fuel gas with high concentration, and if the fuel gas leakage is detected, an alarm signal is generated, and compared with the prior art, the fuel gas leakage detection alarm device has the advantages that the detection alarm device is simple in structure and convenient to use. The gas is compressed in the initial leakage stage, so that the gas concentration is increased, and whether the gas leaks or not can be found in time.

Description

Technical Field

[0001] The present invention relates to the technical field of gas leakage alarm, and particularly to a gas leakage alarm device for detecting pressure fluctuation at the end of a pipeline. Background Art

[0002] In the gas pipeline transmission and distribution link, the pressure regulating box plays a crucial role in the operation of the gas pipeline network. Usually, the pressure regulating box is regularly inspected and maintained by pipeline patrol personnel. However, it is obviously not in line with the actual situation to rely on staff to detect the gas pressure and leakage in each pressure regulating box. Therefore, in the prior art, an alarm system or device that can replace manual inspection is needed to detect the gas pressure fluctuation and gas leakage in the pressure regulating box.

[0003] After retrieval, a detection and alarm system for pressure fluctuation and gas leakage at the end of a pipeline disclosed in the Chinese Utility Model Patent Publication No. CN214279137U includes a high and low pressure alarm module, a gas alarm module, and a communication alarm automatic dialing module. The high and low pressure alarm module and the gas alarm module are respectively electrically connected to the communication alarm automatic dialing module. The high and low pressure alarm module detects pressure fluctuation and generates a first trigger signal. The gas alarm module detects gas leakage and generates a second trigger signal. The first trigger signal and the second trigger signal trigger the communication alarm automatic dialing module to perform automatic dialing alarm.

[0004] The leakage alarm system in the above prior art relies on a gas detection probe to detect gas leakage at the pipeline connection end. However, since the gas leakage rate varies, when the gas leakage rate is small, it takes a long time for the gas to reach a certain concentration and then be detected by the gas detection probe. At this time, the gas leakage has continued for a long time. Therefore, the existing leakage alarm system cannot detect gas leakage in time. Summary of the Invention

[0005] The purpose of the present invention is to provide a gas leakage alarm device for detecting pressure fluctuation at the end of a pipeline to solve the problems raised in the above background art.

[0006] To achieve the above purpose, the present invention provides the following technical solutions: A gas leakage alarm device for detecting pressure fluctuation at the end of a pipeline includes two adjacent gas pipelines installed in an external pressure regulating box. Flange ends are fixedly connected to the opposite ends of the two gas pipelines, and the adjacent flange ends are detachably connected. The device further includes: A detachable airtight sleeve sleeved on the peripheries of the two gas pipelines. The flange ends are located inside the detachable airtight sleeve, and the inner cavity of the detachable airtight sleeve is evacuated. A compression seat fixedly connected to the outer wall of the detachable airtight sleeve, the interior of the compression seat being hollow and communicating with the inner cavity of the detachable airtight sleeve; A detection and alarm unit installed on the outer wall of the compression seat; A gas compression unit provided in the compression seat, the gas compression unit being used to compress the gas leaked from the abutting surfaces of the two flange ends, and the compressed gas being detected by the detection and alarm unit.

[0007] Through the above technical solution, the gas leaked from the gas pipeline is compressed by the gas compression unit, so as to increase the concentration of the leaked gas in the initial stage of leakage, enabling the detection and alarm unit to detect the gas with a higher concentration. If gas leakage is detected, an alarm signal will be generated. Compared with the prior art, since the gas is compressed in the initial stage of leakage to increase the gas concentration, it is possible to detect whether gas leaks in a timely manner.

[0008] Further, the detection and alarm unit includes a high-voltage trigger circuit provided on the dial and pointer of an external explosion-proof electric contact pressure gauge. The high-voltage trigger circuit is electrically connected to a controller, and the controller is electrically connected to a gas detection probe. A detection port is opened on the outer wall of the compression seat, and a hollow seat is installed at the end of the detection port. The gas detection probe is installed in the hollow seat.

[0009] Through the above technical solution, when the gas pressure of the gas pipeline fluctuates, the pointer of the explosion-proof electric contact pressure gauge will swing, causing the high-voltage trigger circuit to be turned on. The controller controls the gas detection probe to start, and the gas detection probe conducts detection, thereby detecting gas leakage when the gas pressure fluctuates.

[0010] Further, the detachable airtight sleeve includes two jacket sleeves, which are respectively defined as a first jacket sleeve and a second jacket sleeve. The first jacket sleeve and the second jacket sleeve are spliced into an annular structure and clamp the periphery of the gas pipeline. The compression seat is fixedly connected to the periphery of the first jacket sleeve.

[0011] Through the above technical solution, the gas pipeline is clamped by the first jacket sleeve and the second jacket sleeve, so that the gas pipeline is assembled and connected with the detachable airtight sleeve.

[0012] Further, arc-shaped flanges are fixedly connected to the end faces of the first jacket sleeve and the second jacket sleeve respectively. The arc-shaped flanges are engaged with the periphery of the gas pipeline, and the arc-shaped flanges on the first jacket sleeve and the second jacket sleeve are detachably connected.

[0013] Through the above technical solution, when the inner arc surface of the arc-shaped flange is engaged with the gas pipeline, the contact area between the periphery of the gas pipeline and the first jacket sleeve and the second jacket sleeve is increased, so as to improve the sealing performance between the periphery of the gas pipeline and the first jacket sleeve and the second jacket sleeve.

[0014] Further, the gas compression unit includes a sliding plug coaxially engaged in the inner cavity of the compression seat. The sliding plug freely slides in the inner cavity of the compression seat. One end of the compression seat away from the gas pipeline is coaxially penetrated with a sliding rod, and the sliding rod freely slides on the compression seat. The sliding plug is fixedly sleeved on the periphery of the sliding rod. A rotary plug is coaxially engaged in the inner cavity of the compression seat. The rotary plug freely slides in the inner cavity of the compression seat, and the rotary plug is located between the sliding plug and the gas pipeline. The end faces of the sliding plug and the rotary plug are in contact with each other, and a first communication groove and a second communication groove are respectively formed on the end faces of the two. The rotary plug is rotatably sleeved on the end of the sliding rod. A communication component is arranged on the compression seat. The communication component is used to drive the rotary plug and the sliding plug to move away from the gas pipeline, and rotate the rotary plug by a fixed angle, so that the first communication groove and the second communication groove are in a staggered distribution state.

[0015] Through the above technical solution, the communication component drives the sliding rod to move away from the gas pipeline, so that the sliding rod drives the rotary plug and the sliding plug to move synchronously. When the rotary plug moves, it rotates at the same time, so that the first communication groove and the second communication groove change from the original state of overlapping openings to a staggered distribution state. When the sliding plug moves away from the gas pipeline, the sliding plug and the rotary plug can compress the gas in the compression seat to increase the concentration of the gas.

[0016] Further, two balls are rotatably embedded on the periphery of the rotary plug. An irregular rolling groove for engaging the balls is formed on the inner cavity wall of the compression seat. The irregular rolling groove sequentially includes a spiral rolling groove and a straight-section rolling groove away from the gas pipeline. The balls freely roll in the spiral rolling groove and the straight-section rolling groove.

[0017] Through the above technical solution, when the rotary plug moves away from the gas pipeline, the balls will roll from the spiral rolling groove into the straight-section rolling groove. During the rolling process, the balls will drive the rotary plug to rotate, so that the rotary plug rotates around the axis of the sliding rod.

[0018] Further, the communication component includes a mounting seat connected to the end face of the compression seat. One end of the sliding rod penetrating into the mounting seat is fixedly sleeved with a sliding block. An electromagnet is connected to the inner cavity wall of the mounting seat. The electromagnet and the sliding block are used in cooperation, and a first elastic member is arranged between the two. The first elastic member has an elastic abutting force on the sliding block in the direction away from the electromagnet.

[0019] Through the above technical solution, when the electromagnet is energized, it generates magnetism and produces magnetic attraction on the sliding block, thereby driving the sliding block to move in the mounting seat in the direction away from the electromagnet, and driving the sliding rod to move synchronously. The sliding block compresses the first elastic part, causing the first elastic part to accumulate elastic potential energy. When the electromagnet is de-energized, the elastic potential energy accumulated in the first elastic part is released, thereby driving the sliding block to move in the opposite direction.

[0020] Furthermore, the controller is electrically connected to a time delay relay, and the time delay relay is electrically connected to the electromagnet.

[0021] Through the above technical solution, when the signal of the high-voltage trigger circuit is fed back to the controller, the controller starts the delay relay, and the delay relay controls the delayed power supply of the electromagnet, so that the gas in the gas pipeline has a certain leakage time, so that the gas leaked from the compression seat has a sufficient concentration.

[0022] Furthermore, an extrusion ring plate is mounted on the periphery of the gas pipeline, and the extrusion ring plate slides freely on the periphery of the gas pipeline. A second elastic member is provided between the extrusion ring plate and the inner cavity walls of the first jacket and the second jacket. The second elastic member has an elastic push force on the extrusion ring plate toward the flange end, and the outer wall of the rotating plug is provided with a toggle assembly for driving the extrusion ring plate to move away from the flange end.

[0023] Through the above technical solution, when the rotary plug moves in the direction away from the gas pipeline, the toggle assembly moves synchronously, so that under the elastic supporting force of the second elastic member, the two extrusion ring plates will move closer to each other and squeeze the gas in the first jacket and the second jacket into the compression seat.

[0024] Furthermore, the shifting assembly includes two shifting blocks fixedly connected to the end surface of the rotating plug, the thickness of the shifting blocks is smaller than the thickness of the flange end, and the two shifting blocks are respectively against the end surfaces of the two extrusion ring plates.

[0025] Through the above technical solution, when the rotating plug rotates, the shift block will rotate, and the outer walls on both sides of the shift block in the thickness direction will rotate to a state facing the extrusion ring plate, so that the extrusion ring plate can move toward the flange end, and then the extrusion ring plate can squeeze the leaked gas in the first jacket and the second jacket into the compression seat.

[0026] Compared with the prior art, the present invention has the following beneficial effects: 1. In the present invention, the gas compression unit compresses the gas leaked from the gas pipeline, thereby increasing the concentration of the leaked gas at the initial stage of leakage, so that the detection alarm unit detects the gas with a larger concentration. If a gas leak is detected, an alarm signal will be generated. Compared with the prior art, since the gas is compressed at the initial stage of leakage to increase the gas concentration, it is possible to detect whether the gas is leaking in time; 2. In the present invention, the connecting component drives the sliding rod to move in a direction away from the gas pipeline, so that the sliding rod drives the rotating plug and the sliding plug to move synchronously. When the rotating plug moves, it rotates at the same time, so that the first connecting groove and the second connecting groove change from the original mouth overlap state to the staggered distribution state, so that when the sliding plug moves in a direction away from the gas pipeline, the sliding plug and the rotating plug can compress the gas in the compression seat to increase the concentration of the gas; 3. In the present invention, when the rotary plug rotates, the shift block will rotate, and the outer walls on both sides of the shift block in the thickness direction will rotate to a state facing the extrusion ring plate, so that the extrusion ring plate can move toward the flange end, and then the extrusion ring plate can squeeze the leaked gas in the first jacket and the second jacket into the compression seat. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a schematic diagram of the framework structure of a gas leakage alarm device for detecting pressure fluctuations at the end of a pipeline in the present invention; Figure 2 It is a schematic diagram of the positional relationship of the jacket, the gas pipeline and the compression seat after assembly in the present invention; Figure 3 for Figure 2 Schematic diagram of the positional relationship after the middle part of the structure is cut open; Figure 4 for Figure 2 Schematic diagram of the explosion decomposition of the structure in the middle; Figure 5 for Figure 4 A magnified schematic diagram of the local structure at point A; Figure 6 for Figure 2 A schematic diagram of the positional relationship from another perspective; Figure 7 for Figure 6 Schematic diagram of the positional relationship of some structures after being cut open from another perspective; Figure 8 It is a schematic structural diagram of the first jacket in the present invention; Figure 9 for Figure 8 A schematic diagram of the positional relationship from another perspective; Figure 10 for Figure 9 A schematic cross-sectional view of the structure; Figure 11 This is a schematic diagram of the positional relationship after the rotary plug and the dial block are assembled in the present invention.

[0028] In the figure, the descriptions of each reference numeral are as follows: 1, high-voltage trigger circuit; 2, controller; 3, time-delay relay; 4, battery; 5, gas detection probe; 6, gas pipeline; 7, first jacket; 8, compression seat; 9, mounting seat; 10, hollow seat; 11, second jacket; 12, electromagnet; 13, first elastic member; 14, sliding block; 15, sliding rod; 16, sliding plug; 17, dial block; 18, first communication groove; 19, rotary plug; 20, flange end; 21, extrusion ring plate; 22, second elastic member; 23, second communication groove; 24, ball; 25, detection port; 26, vacuum extraction port; 27, straight-section rolling groove; 28, spiral rolling groove. Specific embodiments

[0029] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present invention.

[0030] Please refer to Figure 1 - Figure 11 , the present invention provides a technical solution: a gas leakage alarm device for detecting pressure fluctuations at the end of a pipeline, including two adjacent gas pipelines 6 installed in an external pressure regulating box. Flange ends 20 are fixedly connected to the opposite ends of the two gas pipelines 6. The adjacent two flange ends 20 are connected by a screw pair, and the flange end 20 is sealed by a gasket. A detachable airtight sleeve is assembled on the periphery of the gas pipeline 6. The detachable airtight sleeve includes two jackets, which are respectively defined as the first jacket 7 and the second jacket 11. The first jacket 7 and the second jacket 11 are spliced into an annular structure and clamp the periphery of the gas pipeline 6. A compression seat 8 is fixedly connected to the periphery of the first jacket 7. Arc-shaped flanges are fixedly connected to the end faces of the first jacket 7 and the second jacket 11. The arc-shaped flanges are engaged with the periphery of the gas pipeline 6, and the arc-shaped flanges on the first jacket 7 and the second jacket 11 are connected by screws. An explosion-proof electric contact pressure gauge is installed on one of the gas pipelines 6. A high-voltage trigger circuit 1 is provided on the pointer and the dial of the explosion-proof electric contact pressure gauge. The structure and working principle of the high-voltage trigger circuit 1 can refer to the high-low voltage trigger alarm module in Chinese Patent Publication No. CN214279137U. The periphery of the first jacket 7 is welded with a compression seat 8. The inside of the compression seat 8 is hollow. A communication cavity is formed between the inner cavities of the first jacket 7 and the second jacket 11. The flange ends 20 on the two gas pipelines 6 are located in the communication cavity. A vacuum extraction port 26 is provided on the periphery of the second jacket 11 (as Figure 6As shown in the figure, through the vacuum pumping port 26, the communication cavity can be evacuated, so that a vacuum state is formed in the communication cavity. The outer wall on the upper side of the compression seat 8 is provided with a detection port 25, and a hollow seat 10 is installed on the detection port 25. A gas detection probe 5 is installed in the hollow seat 10. A battery 4 and a controller 2 are installed in the pressure regulating box. The controller 2 is electrically connected to the high-voltage trigger circuit 1, and the controller 2 and the high-voltage trigger circuit 1 are powered by the battery 4. A sliding plug 16 is coaxially clamped and installed in the inner cavity of the compression seat 8. The sliding plug 16 slides freely in the inner cavity of the compression seat 8. A sliding rod 15 is coaxially penetrated through one end of the compression seat 8 away from the gas pipeline 6. The sliding rod 15 slides freely on the compression seat 8. The sliding plug 16 is fixedly sleeved on the periphery of the sliding rod 15. A rotary plug 19 is coaxially clamped in the inner cavity of the compression seat 8. The rotary plug 19 slides freely in the inner cavity of the compression seat 8, and the rotary plug 19 is located between the sliding plug 16 and the gas pipeline 6. The end faces of the sliding plug 16 and the rotary plug 19 are in contact with each other, and the first communication groove 18 and the second communication groove 23 are respectively opened on the end faces of the two. The rotary plug 19 is rotatably sleeved on the end of the sliding rod 15. In the initial state, the mouths of the first communication groove 18 and the second communication groove 23 coincide, so that the first communication groove 18 and the second communication groove 23 are in a communicating state. When the sliding rod 15 moves in the outer direction of the compression seat 8, it drives the sliding plug 16 to move synchronously in the direction away from the gas pipeline 6, and at the same time drives the rotary plug 19 to move in the direction away from the gas pipeline 6. Two balls 24 are rotatably embedded on the periphery of the rotary plug 19 (as Figure 11 shown). The inner cavity wall of the compression seat 8 is provided with a special-shaped rolling groove for the balls 24 to engage. The special-shaped rolling groove includes a spiral rolling groove 28 and a straight-section rolling groove 27 in sequence in the direction away from the gas pipeline 6. The balls 24 roll freely in the spiral rolling groove 28 and the straight-section rolling groove 27. When the rotary plug 19 moves in the direction away from the gas pipeline 6, the balls 24 will roll from the spiral rolling groove 28 into the straight-section rolling groove 27. During the rolling process, the balls 24 will drive the rotary plug 19 to rotate, so that the rotary plug 19 rotates around the axis of the sliding rod 15. The end face of the compression seat 8 is connected to the mounting seat 9 by means of screws. One end of the sliding rod 15 passing through the mounting seat 9 is fixedly sleeved with a sliding block 14. The sliding block 14 is made of any material among iron, cobalt, and nickel. The inner cavity wall of the mounting seat 9 is connected with an electromagnet 12. The electromagnet 12 and the sliding block 14 are used in cooperation, and a first elastic member 13 is provided between the two. The first elastic member 13 has an elastic abutting force on the sliding block 14 in the direction away from the electromagnet 12. The controller 2 is electrically connected to a time-delay relay 3. The time-delay relay 3 is installed in the external pressure regulating box. The time-delay relay 3 is electrically connected to the electromagnet 12. The electromagnet 12 is powered by the battery 4. A squeezing ring plate 21 is sleeved on the periphery of the gas pipeline 6. The squeezing ring plate 21 can freely slide on the periphery of the gas pipeline 6. A second elastic member 22 is arranged between the squeezing ring plate 21 and the inner cavity walls of the first jacket 7 and the second jacket 11. The second elastic member 22 has an elastic abutting force on the squeezing ring plate 21 towards the flange end 20. Two dial blocks 17 are fixedly connected to the end face of the rotary plug 19. The thickness dimension of the dial block 17 is smaller than the thickness dimension of the flange end 20, and the two dial blocks 17 respectively abut against the end faces of the two squeezing ring plates 21.

[0031] The working principle of the present invention: When there is a pressure fluctuation during gas transmission, if the sealing performance of the flange end 20 decreases and the gas pressure becomes too high as a result, the gas leaks out from the flange end 20. The leaked gas will enter the communication cavity. Additionally, when there is a pressure fluctuation, the pointer of the explosion-proof electric contact pressure gauge swings, that is, the pointer swings from the area with a small value to the area with a large value, which causes the high-voltage trigger circuit 1 to generate a signal and feedback it to the controller 2. The controller 2 controls the time-delay relay 3 to act and delays to turn on the power supply of the electromagnet 12. During the delay process (the delay duration is usually within 1 - 2 minutes), the leaked gas is stored in the communication cavity. After the delay ends, the power supply of the electromagnet 12 is turned on; The electromagnet 12 generates magnetism and produces a magnetic attraction force on the sliding block 14, thereby driving the sliding block 14 to move away from the gas pipeline 6. At the same time, it drives the sliding rod 15, the sliding plug 16, and the rotary plug 19 to move away from the gas pipeline 6 synchronously. When the rotary plug 19 moves, the ball 24 will roll from the spiral rolling groove 28 into the straight-section rolling groove 27. When the ball 24 rolls in the spiral rolling groove 28, it will drive the rotary plug 19 to rotate around its own axis. When the rotary plug 19 rotates, the two dial blocks 17 gradually rotate around the axis of the rotary plug 19 to 90°. Then, with the elastic abutting force of the second elastic member 22 on the squeezing ring plate 21, the outer side in the thickness direction of the dial block 17 contacts the squeezing ring plate 21. At the same time, when the squeezing ring plate 21 moves towards the flange end 20, it will squeeze the gas in the communication cavity, which is equivalent to reducing the internal volume of the communication cavity. In this way, the gas in the communication cavity will be squeezed into the first communication groove 18 and the second communication groove 23 and enter the inner cavity of the compression seat 8; The first communication groove 18 and the second communication groove 23 change from the original state of overlapping openings to a staggered state, so that the inner cavity of the compression seat 8 is in a closed state. And when the ball 24 rolls into the straight-section rolling groove 27, the sliding plug 16 will compress the gas in the compression seat 8, so that the gas in the compression seat 8 is squeezed and its concentration increases. In this way, the gas with increased concentration will enter the hollow seat 10, enabling the gas detection probe 5 to detect in time. When the gas detection probe 5 detects a gas signal, it will feedback to the controller 2. The controller 2 will generate an alarm signal and remotely feedback it to the external cloud or management terminal, thereby realizing remote inspection; When the sliding block 14 moves in the outer direction of the compression seat 8, the first elastic member 13 will be compressed to accumulate elastic potential energy. When the electromagnet 12 is powered off, the elastic potential energy accumulated by the first elastic member 13 is released, driving the sliding block 14 to move in the direction of the first jacket 7, causing the ball 24 to roll from the straight-section rolling groove 27 to the spiral rolling groove 28, causing the rotary plug 19 to rotate in the reverse direction, and causing the dial block 17 to contact and squeeze the ring plate 21, pushing the ring plate 21 to move away from the flange end 20, so that the internal volume of the communication cavity increases again. The purpose of designing that the two ring plates 21 can move relative to each other is that since the flange end 20 is usually connected by bolts, the part of the bolt passing through the flange end 20 has a certain size, and the communication cavity often needs to reserve enough space for bolt installation, so the volume of the communication cavity is relatively large, which makes it impossible to timely introduce the leaked gas into the compression seat 8. By moving the two ring plates 21 closer to each other, the ring plate 21 abuts against the end of the bolt. At this time, the ring plate 21 can squeeze the gas in the communication cavity into the compression seat 8 as much as possible. After the detection is completed, the ring plates 21 move away from each other, so that the bolt is separated from the contact with the ring plate 21, facilitating installation, operation and maintenance.

[0032] It should be noted that in this text, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprising", "including" or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article or device. Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A gas leakage alarm device for detecting pressure fluctuations at the end of a pipeline, comprising two adjacent gas pipelines (6) installed in an external pressure regulating box. Flange ends (20) are fixedly connected to the opposite ends of the two gas pipelines (6), and the adjacent two flange ends (20) are detachably connected. It is characterized in that, Further comprising: A detachable airtight sleeve sleeved on the peripheries of the two gas pipelines (6), with the flange end (20) located inside the detachable airtight sleeve and the inner cavity of the detachable airtight sleeve evacuated; A compression seat (8) fixedly connected to the outer wall of the detachable airtight sleeve, the interior of the compression seat (8) being hollow and communicating with the inner cavity of the detachable airtight sleeve; A detection and alarm unit installed on the outer wall of the compression seat (8); A gas compression unit provided in the compression seat (8), the gas compression unit being used to compress the gas leaked from the abutting surfaces of the two flange ends (20), and the compressed gas being detected by the detection and alarm unit.

2. The gas leakage alarm device for detecting pressure fluctuations at the end of a pipeline according to claim 1, characterized in that The detection and alarm unit includes a high-voltage trigger circuit (1) provided on the dial and pointer of an external explosion-proof electrical contact pressure gauge, the high-voltage trigger circuit (1) being electrically connected to a controller (2), the controller (2) being electrically connected to a gas detection probe (5), a detection port (25) being opened on the outer wall of the compression seat (8), a hollow seat (10) being installed at the end of the detection port (25), and the gas detection probe (5) being installed in the hollow seat (10).

3. The gas leakage alarm device for detecting pressure fluctuations at the end of a pipeline according to claim 2, wherein The detachable airtight sleeve includes two jacket sleeves, which are respectively defined as a first jacket sleeve (7) and a second jacket sleeve (11), the first jacket sleeve (7) and the second jacket sleeve (11) being spliced into an annular structure and clamping the peripheries of the gas pipelines (6), and the compression seat (8) being fixedly connected to the periphery of the first jacket sleeve (7).

4. The pipeline end pressure fluctuation detection gas leakage alarm device according to claim 3, characterized in that, Arc-shaped flanges are fixedly connected to the end faces of the first jacket sleeve (7) and the second jacket sleeve (11), the arc-shaped flanges being engaged with the peripheries of the gas pipelines (6), and the arc-shaped flanges on the first jacket sleeve (7) and the second jacket sleeve (11) being detachably connected.

5. The gas leakage alarm device for detecting pressure fluctuations at the end of a pipeline according to claim 3, characterized in that, The gas compression unit includes a sliding plug (16) coaxially engaged in the inner cavity of the compression seat (8), the sliding plug (16) being free to slide in the inner cavity of the compression seat (8), a sliding rod (15) being coaxially inserted through one end of the compression seat (8) away from the gas pipeline (6), the sliding rod (15) being free to slide on the compression seat (8), the sliding plug (16) being fixedly sleeved on the periphery of the sliding rod (15), a rotary plug (19) being coaxially engaged in the inner cavity of the compression seat (8), the rotary plug (19) being free to slide in the inner cavity of the compression seat (8), and the rotary plug (19) being located between the sliding plug (16) and the gas pipeline (6), the end faces of the sliding plug (16) and the rotary plug (19) being in contact and respectively provided with a first communication groove (18) and a second communication groove (23), the rotary plug (19) being rotatably sleeved on the end of the sliding rod (15), and a communication component being provided on the compression seat (8), the communication component being used to drive the rotary plug (19) and the sliding plug (16) to move away from the gas pipeline (6) and rotate the rotary plug (19) by a fixed angle, so that the first communication groove (18) and the second communication groove (23) are in a staggered distribution state.

6. The gas leakage alarm device for detecting pressure fluctuations at the end of a pipeline according to claim 5, characterized in that, The rotary plug (19) is rotatably embedded with two balls (24) on its circumference, and the inner wall of the compression seat (8) is provided with a special-shaped rolling groove for the balls (24) to engage with. The special-shaped rolling groove includes a spiral rolling groove (28) and a straight rolling groove (27) in sequence in a direction away from the gas pipeline (6), and the balls (24) roll freely in the spiral rolling groove (28) and the straight rolling groove (27).

7. The gas leakage alarm device for detecting pressure fluctuations at the end of a pipeline according to claim 5, characterized in that, The connecting component comprises a mounting seat (9) connected to the end surface of the compression seat (8); one end of the sliding rod (15) inserted into the mounting seat (9) is fixedly sleeved with a sliding block (14); an inner cavity wall of the mounting seat (9) is connected to an electromagnet (12); the electromagnet (12) and the sliding block (14) are used in conjunction with each other and a first elastic member (13) is provided between the two; the first elastic member (13) has an elastic resisting force on the sliding block (14) in a direction away from the electromagnet (12).

8. The gas leakage alarm device for detecting pressure fluctuations at the end of a pipeline according to claim 7, characterized in that, The controller (2) is electrically connected to a time delay relay (3), and the time delay relay (3) is electrically connected to the electromagnet (12).

9. The pipeline end pressure fluctuation detection gas leakage alarm device according to claim 5, characterized in that An extrusion ring plate (21) is sleeved on the periphery of the gas pipeline (6), and the extrusion ring plate (21) slides freely on the periphery of the gas pipeline (6). A second elastic member (22) is provided between the extrusion ring plate (21) and the inner cavity walls of the first jacket (7) and the second jacket (11), and the second elastic member (22) exerts an elastic abutting force on the extrusion ring plate (21) toward the flange end (20). The outer wall of the rotary plug (19) is provided with a toggle assembly for driving the extrusion ring plate (21) to move away from the flange end (20).

10. The gas leakage alarm device for detecting pressure fluctuations at the end of a pipeline according to claim 9, characterized in that, The shifting assembly comprises two shifting blocks (17) fixedly connected to the end surface of the rotating plug (19), the thickness of the shifting blocks (17) being smaller than the thickness of the flange end (20), and the two shifting blocks (17) respectively abut against the end surfaces of two extrusion ring plates (21).

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