SF6 gas leakage monitoring device

Abstract

The utility model relates to the technical field of gas leakage monitoring, and particularly discloses an SF6 gas leakage monitoring device which is characterized in that a suction type air duct structure is fixedly arranged at the bottom end in a high-voltage electric appliance cabinet and comprises an air inlet cylinder, an axial flow fan, a monitoring cylinder and an air exhaust cylinder which are sequentially connected in series and communicated, and a filter screen cover A is detachably arranged at the front end of the air inlet cylinder; a branch cylinder is arranged at the top end of the air inlet cylinder in a communicating mode, a filter screen cover B is arranged above the branch cylinder, and an NDIR sensor used for detecting the SF gas concentration is arranged in the monitoring cylinder. According to the device, a traditional suction type gas monitoring channel is improved, the height-adjustable external thread sleeve is additionally arranged, so that a suction inlet of the newly-added gas monitoring channel is close to the insulation switch equipment, SF6 gas can be sucked into the gas monitoring channel in time when leaked, the NDIR sensor rapidly detects the gas and cooperates with the controller to start an alarm, and the SF6 gas leakage detection efficiency is improved. And the low-position air inlet barrel is reserved and used for monitoring the SF6 gas at the low position in the normal state.

Description

Technical Field

[0001] This utility model relates to the field of gas leak monitoring technology, specifically to an SF6 gas leak monitoring device. Background Technology

[0002] SF6 (sulfur hexafluoride) gas is widely used in high-voltage electrical equipment, such as circuit breakers and GIS (gas-insulated switchgear), due to its excellent insulation and arc-quenching properties. However, SF6 gas leakage can not only lead to a decrease in the insulation performance of equipment, but also pose safety hazards and have a negative impact on the environment (SF6 is a potent greenhouse gas).

[0003] Currently, SF6 gas leak detection involves installing multiple SF6 gas sensors near high-voltage switchgear to monitor concentration and trigger alarms. This is combined with the removal of leaked gas by fans. However, SF6 is heavier than air and gradually settles to the bottom, resulting in lower concentrations at the top. Therefore, placing SF6 gas sensors at the bottom requires the gas to gradually settle. To shorten the response time for gas leaks, SF6 gas sensors need to be installed at both the high and low positions within the cabinet, significantly increasing costs. Therefore, we propose an SF6 gas leak detection device. Utility Model Content

[0004] In view of the above-mentioned technical problems in related technologies, this utility model provides an SF6 gas leakage monitoring device that can solve the above problems.

[0005] To achieve the above-mentioned technical objectives, the technical solution of this utility model is implemented as follows:

[0006] An SF6 gas leak monitoring device includes a high-voltage electrical cabinet and an insulating switchgear installed inside the high-voltage electrical cabinet. An intake air duct structure is fixedly installed at the bottom of the high-voltage electrical cabinet. The intake air duct structure includes an air inlet duct, an axial flow fan, a monitoring duct, and an exhaust duct that are connected in series. A filter screen cover A is detachably installed at the front end of the air inlet duct. A branch duct is connected to the top end of the air inlet duct. A filter screen cover B is installed above the branch duct.

[0007] The monitoring cylinder is equipped with an NDIR sensor A for detecting SF gas concentration. The NDIR sensor A is electrically connected to a controller located outside the monitoring cylinder via a wire.

[0008] Furthermore, a side exhaust pipe is connected and installed in the middle of the exhaust duct, a solenoid valve A is connected and installed at the output end of the exhaust duct, and a solenoid valve B is connected and installed at the output end of the side exhaust pipe. Both solenoid valve A and solenoid valve B are electrically connected to the controller.

[0009] Furthermore, the top of the branch cylinder is threaded with an external threaded sleeve, and the filter screen cover B is fixed to the top of the external threaded sleeve.

[0010] Furthermore, a fixing sleeve is provided on the outer circumference of one end of the air inlet duct and the monitoring duct, and the fixing sleeve is fastened to the axial flow fan by bolts.

[0011] Furthermore, the front end of the air inlet duct is integrally formed with an external thread section, and the inner wall of the filter screen A is provided with an internal thread section that is threaded to the external thread section.

[0012] Furthermore, an NDIR sensor B is fixedly installed on the outside of the monitoring cylinder, and the NDIR sensor B is electrically connected to the controller via a wire.

[0013] The beneficial effects of this utility model are as follows: The device of this application improves the traditional inhalation gas monitoring channel by adding an adjustable height external threaded sleeve, so that the inlet of the new gas monitoring channel is close to the insulating switch equipment, which can promptly draw SF6 gas into the gas monitoring channel when SF6 gas leaks. The NDIR sensor quickly detects the gas and cooperates with the controller to activate the alarm. The low-position air inlet is reserved for monitoring SF6 gas that is at a low position under normal conditions.

[0014] By installing a side exhaust duct on the exhaust duct, the airflow inside the high-voltage electrical cabinet circulates internally under the action of the axial flow fan when there is no gas leakage. When there is a gas leak, the controller controls solenoid valve A to close and solenoid valve B to open, thereby expelling the leaked SF6 gas from the high-voltage electrical cabinet and improving the safety of the working environment inside the cabinet. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] The present invention will now be described in further detail with reference to the accompanying drawings.

[0017] Figure 1 This is an installation diagram of an SF6 gas leak monitoring device installed in a high-voltage electrical cabinet;

[0018] Figure 2 This is a schematic diagram of an SF6 gas leak monitoring device.

[0019] In the picture:

[0020] 1. High-voltage electrical cabinet; 2. Insulating switchgear; 3. Air inlet duct; 4. Branch duct; 5. Filter screen cover A; 6. External threaded sleeve; 601. Filter screen cover B; 7. Axial flow fan; 8. Controller; 9. Monitoring duct; 10. NDIR sensor A; 11. NDIR sensor B; 12. Exhaust duct; 13. Solenoid valve A; 14. Side exhaust duct; 15. Solenoid valve B. Detailed Implementation

[0021] 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. All other embodiments obtained by those skilled in the art based on the embodiments of the present utility model are within the protection scope of the present utility model.

[0022] like Figure 1-2 As shown, this utility model discloses an SF6 gas leakage monitoring device, including a high-voltage electrical cabinet 1 and an insulating switchgear 2 installed inside the high-voltage electrical cabinet. The bottom of the high-voltage electrical cabinet 1 is fixedly provided with an intake air duct structure. The intake air duct structure includes an air inlet duct 3, an axial flow fan 7, a monitoring cylinder 9 and an exhaust duct 12 installed in series. A filter screen cover A5 is detachably installed at the front end of the air inlet duct 3. A branch cylinder 4 is connected to the top end of the air inlet duct 3. A filter screen cover B601 is installed above the branch cylinder 4.

[0023] The monitoring cylinder 9 is equipped with an NDIR sensor A10 for detecting SF6 gas concentration. The NDIR sensor A10 is electrically connected to the controller 8 located outside the monitoring cylinder 9 via a wire. A side exhaust cylinder 14 is connected to the middle of the exhaust cylinder 12. A solenoid valve A13 is connected to the output end of the exhaust cylinder 12. A solenoid valve B15 is connected to the output end of the side exhaust cylinder 14. Both solenoid valves A13 and B15 are electrically connected to the controller 8.

[0024] Example 1: The NDIR sensor used is a LARK-1SHM SF6 100%vol sensor. Its working principle is to utilize the strong absorption characteristics of SF6 gas for 10.55-micron wavelength infrared light. By comparing the changes in light intensity through dual-beam non-dispersive infrared detection technology (measurement channel and reference channel), the gas concentration is calculated. The NDIR sensor has specific absorption for SF6 gas and is not affected by other gases.

[0025] The controller 8 is used to receive the electrical signal from the NDIR sensor. Based on the electrical signal values ​​of different concentrations of SF6 detected by the NDIR sensor, a threshold is set. When there is no gas leakage, the controller 8 controls the solenoid valve A13 to open and the solenoid valve B15 to close. When there is a gas leak, the controller 8 controls the solenoid valve A13 to close and the solenoid valve B15 to open. The exhaust end of the solenoid valve B15 is connected to the combustion chamber through a pipe, and the SF6 gas and its decomposition products are thermally decomposed by high-temperature combustion.

[0026] The axial flow fan 7, controller 8, and NDIR sensor are all powered by connecting to the power module of the high-voltage electrical cabinet 1 via wires.

[0027] In the preferred technical solution, the top of the branch cylinder 4 is threadedly connected to an external threaded sleeve 6, and the filter screen cover B601 is fixed to the top of the external threaded sleeve 6. The external threaded sleeve 6 can be adjusted by rotation, thereby adjusting the position of the filter screen cover B601 so that the filter screen cover B601 can be close to the insulating switchgear 2.

[0028] In the preferred technical solution, a fixing sleeve is provided on the outer circumferential surface of both the air inlet duct 3 and the monitoring duct 9. The fixing sleeve is fastened to the axial flow fan 7 by bolts. The outer circumferential surface of the axial flow fan 7 is also provided with an inner threaded hole sleeve that is aligned with the fixing sleeve. The bolts pass through the fixing sleeve and engage with the inner threaded hole sleeve, which facilitates the disassembly and assembly of the axial flow fan 7.

[0029] In the preferred technical solution, the front end of the air inlet duct 3 is integrally formed with an external thread section, and the inner wall of the filter screen cover A5 is provided with an internal thread section that is threaded to the external thread section, so as to facilitate the disassembly of the filter screen cover A5 for cleaning.

[0030] In the preferred technical solution, an NDIR sensor B11 is fixedly installed on the outside of the monitoring cylinder 9. The NDIR sensor B11 is electrically connected to the controller 8 through a wire to prevent the NDIR sensor A10 from failing to detect SF6 gas in time due to a malfunction of the axial flow fan 7. The external NDIR sensor B11 serves as a backup alarm function.

[0031] In practical use, when there is no leakage of normal gas, the controller 8 controls the solenoid valve A13 to open and the solenoid valve B15 to close. The axial flow fan 7 is constantly open and running. Both the filter screen B601 and the filter screen A5 can absorb and guide the airflow into the air inlet duct 3 and the monitoring duct 9, and finally discharge it from the exhaust duct 12. When SF6 gas leaks, the NDIR sensor A10 sends an electrical signal to the controller 8, which controls the solenoid valve A13 to close and the solenoid valve B15 to open. The exhaust end of the solenoid valve B15 is connected to the combustion chamber through a pipe. The SF6 gas and its decomposition products are thermally decomposed by high-temperature combustion. When the NDIR sensor B11 detects SF6 gas, it also sends an electrical signal to the controller 8, which controls the solenoid valve A13 to close and the solenoid valve B15 to open. The external NDIR sensor B11 serves as a backup alarm function.

[0032] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A SF6 gas leakage monitoring device, comprising a high-voltage electrical cabinet (1) and an insulated switchgear (2) arranged inside the high-voltage electrical cabinet, characterized in that: The high-voltage electrical cabinet (1) is fixedly provided with an intake air duct structure at the bottom. The intake air duct structure includes an air inlet duct (3), an axial flow fan (7), a monitoring duct (9) and an exhaust duct (12) that are connected in series. A filter screen cover A (5) is detachably installed at the front end of the air inlet duct (3). A branch duct (4) is connected to the top end of the air inlet duct (3). A filter screen cover B (601) is installed above the branch duct (4). The monitoring cylinder (9) is equipped with an NDIR sensor A (10) for detecting SF6 gas concentration. The NDIR sensor A (10) is electrically connected to a controller (8) located outside the monitoring cylinder (9) via a wire.

2. The SF6 gas leakage monitoring device according to claim 1, characterized in that, The exhaust duct (12) is connected to a side exhaust duct (14) in the middle. The exhaust duct (12) is connected to a solenoid valve A (13) in the output end. The side exhaust duct (14) is connected to a solenoid valve B (15) in the output end. Both the solenoid valve A (13) and the solenoid valve B (15) are electrically connected to the controller (8). 3.The SF6 gas leakage monitoring device of claim 1, wherein, The top of the branch cylinder (4) is threadedly connected to an external threaded sleeve (6), and the filter screen cover B (601) is fixed to the top of the external threaded sleeve (6).

4. The SF6 gas leakage monitoring device according to claim 1, characterized in that, The air inlet duct (3) and the monitoring duct (9) are both provided with a fixing sleeve on the outer circumference of one end, and the fixing sleeve is fastened to the axial flow fan (7) by bolts.

5. The SF6 gas leakage monitoring device according to claim 1, characterized in that, The front end of the air inlet duct (3) is integrally formed with an external thread section, and the inner wall of the filter screen cover A (5) is provided with an internal thread section that is threadedly engaged with the external thread section.

6. The SF6 gas leakage monitoring device according to claim 1, characterized in that, An NDIR sensor B (11) is fixedly installed on the outside of the monitoring cylinder (9), and the NDIR sensor B (11) is electrically connected to the controller (8) through a wire.

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