Gas leakage prevention SF6 live-line charging and gas charging pipeline cleaning gas recovery device

Abstract

The utility model discloses an SF6 live-line filling and gas filling pipeline cleaning device, which comprises a pressure reducing valve, a pressure gauge, a gas filling pipe, a one-way conduction assembly and a cleaning pipeline gas recovery steel cylinder, and is characterized in that the pressure reducing valve and the pressure gauge are used for reducing the pressure of high-pressure SF6 gas in an SF6 gas cylinder and monitoring the pressure; the gas filling pipe is used for conveying SF6; the one-way conduction assembly is arranged at the joint of the gas filling pipe and the SF6 gas inlet of the high-voltage electrical equipment and used for controlling SF6 to enter the SF6 gas inlet of the high-voltage electrical equipment from the gas filling pipe in a one-way mode; and the pipeline cleaning gas recovery steel cylinder is used for collecting SF6 gas during pipeline cleaning operation. According to the pipeline cleaning device for the charged filling and gas filling pipeline, the service life of the gas filling pipe can be greatly prolonged, and the leakage-proof effect is more reliable; reverse flow and backward flow do not occur in the electrified air supply, the occurrence of malignant equipment accidents such as locking and tripping caused by air pressure reduction due to air leakage can be effectively prevented, and the continuous stability of the electrified air supply is improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of live gas filling of SF6 gas insulation equipment, in particular to a gas recovery device for leak-proof SF6 live filling and gas filling pipeline cleaning. Background Art

[0002] Pure sulfur hexafluoride (SF6) gas is colorless, odorless, non-flammable, and has stable chemical properties at room temperature, making it an inert gas. At the same time, SF6 is also an asphyxiant. At high concentrations, it can cause breathing difficulties, wheezing, blue skin and mucous membranes, and whole-body spasms. SF6 gas is heavier than air. After inhaling a mixture of 80% sulfur hexafluoride + 20% oxygen for a few minutes, the human body will experience numbness in the limbs, or even suffocate to death. The decomposition products of sulfur hexafluoride gas after arc extinguishing or high temperature, such as hydrogen sulfide, are highly toxic and can also cause disability or death. Therefore, during the SF6 filling operation, it is necessary to prevent SF6 leakage, and even wear special protective clothing to carry out the operation.

[0003] In the power industry, SF6 gas is widely used as an insulating and arc-extinguishing medium for high-voltage electrical equipment. In order to ensure the safe and reliable operation of the equipment, SF6 gas with pressures ranging from 0.4 to 0.8 MPa must be filled into different gas chambers according to the functional differences of each equipment component. At the same time, in order to ensure the stable and reliable operation of the power grid and protect the environment, the annual leakage rate of SF6 gas-insulated equipment must be controlled within 0.5%. However, due to the aging of sealing materials and uneven settlement of the foundation, it is inevitable that the gas pressure in the equipment will drop. If the gas chamber pressure is not replenished to the rated pressure in time, it will inevitably affect the safe and stable operation of the equipment and even the power grid.

[0004] In addition, SF6 gas is also a greenhouse gas, and its greenhouse effect is about 23,000 times that of the same weight of CO2 gas, that is, the greenhouse effect caused by emitting 1 ton of SF6 gas into the atmosphere is equivalent to emitting 23,000 tons of CO2. SF6 gas is one of the six gases that the United Nations Climate Convention has determined to limit greenhouse gas emissions, and excessive emissions will pollute the environment.

[0005] When performing SF6 gas replenishment operations on various high-voltage electrical equipment, there are mainly two working conditions: energized and de-energized.

[0006] In non-powered conditions, air replenishment is usually carried out simultaneously with the equipment power outage for maintenance.

[0007] Under the condition of non-stop power supply, the specific operation of connecting the sulfur hexafluoride gas filling device using the traditional technical method is as follows:

[0008] 1. First connect the pressure reducing valve to the interface of the SF6 gas cylinder.

[0009] 2. Use wire or pipe clamp to tighten the oxygen hose on the outlet interface of the pressure reducing valve.

[0010] 3. Unscrew the dust cover outside the air chamber inflation interface of the equipment to be inflated.

[0011] 4. Insert the other end of the oxygen hose into the interface of the special joint for inflation connected to the equipment, and tighten it with wire or pipe clamp;

[0012] 5. Slowly open the gas cylinder valve and confirm that the pressure in the gas cylinder is higher than the pressure in the gas chamber by the pressure on the high pressure gauge of the pressure reducing valve.

[0013] 6. Slowly open the pressure reducing valve and flush the clean inflation pipeline with a small flow of gas, and disperse the SF6 gas flushed in the pipeline into the air.

[0014] 7. Without closing the pressure reducing valve and creating a slight positive pressure, quickly screw the special inflation connector onto the inflation interface of the air chamber of the equipment to be inflated.

[0015] 8. Open the inflation valve installed on the air chamber of the equipment to be inflated, and continue to inflate air to the rated air pressure. First close the inflation valve on the air chamber of the equipment to be inflated, then close the pressure reducing valve and the gas cylinder valve, and finally, remove the inflation pipeline and pressure reducing valve.

[0016] When using traditional technology to refill SF6 high-voltage electrical equipment that is energized, there are usually the following risks to the safety of the power grid, equipment, and personnel:

[0017] 1. Aging and worn oxygen hoses may burst.

[0018] 2. The iron wire or hose clamp used to tighten the oxygen hose may burst if exposed to high pressure of 0.4-0.8MPa for a long time.

[0019] 3. If the pressure of the gas cylinder is lower than the pressure of the gas chamber, the gas in the gas chamber will flow back into the gas cylinder. The sharp drop in pressure in the gas chamber will cause accidents to the safe operation of equipment and power grid.

[0020] 4. Operators inhale toxic and harmful gases, causing harm to the human body.

[0021] 5. The SF6 gas discharged from the cleaning pipeline pollutes the environment. Utility Model Content

[0022] In order to address the deficiencies in the above-mentioned prior art, the inventors have, after research and development, designed and provided a SF6 leak-proof live filling and filling pipeline cleaning gas recovery device, which can effectively prevent leakage or backflow when gas is replenished under the operating conditions of SF6 gas insulation equipment, thereby improving the safety of gas replenishment and the reliability of equipment operation. At the same time, it improves the efficiency of gas cleaning in the filling pipeline, reduces the pollution of SF6 gas to the environment, enhances the ease of operation of the filling pipeline cleaning process, and greatly helps operators to develop standardized operating behavior habits.

[0023] The technical solution adopted by the utility model is:

[0024] A gas recovery device for anti-leakage SF6 live charging and charging pipeline cleaning is installed between an SF6 gas cylinder (1) and an SF6 gas charging port (8) of an insulating device, and is used for charging an SF6 transmission channel and cleaning the charging pipeline, and comprises:

[0025] A pressure reducing valve and a pressure gauge (2) connected to the SF6 gas cylinder (1) for reducing the pressure of the high-pressure gas in the SF6 gas cylinder (1) and monitoring the pressure;

[0026] A charging pipe (3), one end of which is connected to the pressure reducing valve and the pressure gauge (2), and the other end of which is used to connect to the SF6 gas charging port (8) of the insulating equipment for charging SF6;

[0027] The one-way guide assembly (7) and the cleaning pipeline control three-way joint (4) are sequentially installed at the end of the gas charging pipe (3); the upper and lower ends of the cleaning pipeline control three-way joint (4) are respectively connected to the gas charging pipe and the one-way guide assembly (7); and the side end is connected to the cleaning pipeline gas recovery cylinder (9) through the gas guide pipe;

[0028] The one-way conducting component (7) is arranged at the end of the gas filling pipe (1) and is used to one-way control SF6 so that it can only enter the insulating equipment to be supplemented with gas from the gas filling pipe (3);

[0029] The cleaning pipeline gas recovery cylinder (9) is connected to the cleaning pipeline control three-way joint (4) through the gas guide pipe and is used to recover SF6 during the cleaning of the charging pipeline;

[0030] Valves are installed at both ends of the recovery cylinder. The gas flow direction and flow rate can be changed by adjusting the valves. Connecting threads and pressure gauges are provided at both ends to monitor the gas pressure in the recovery cylinder.

[0031] The recycled cylinders are compatible with the interface of professional SF6 gas processing equipment and can withstand a pressure of 10MPa.

[0032] Furthermore, the one-way conducting component (7) comprises:

[0033] The air cavity (71), serving as the main body of the one-way conducting component (7), has two openings, one above the other;

[0034] The one-way rotating piece (72) is in the shape of a disc and is arranged at the bottom of the connection side between the air cavity (71) and the inflation tube (3); the one-way rotating piece (72) can only rotate from bottom to top to open the lower opening.

[0035] Furthermore, one side of the one-way rotating piece (72) is connected to the rotating shaft on the air cavity (71), and the protruding portion on the other side of the one-way rotating piece (72) overlaps with the flat and smooth valve opening at the bottom of the air cavity (71) to form a planar sealing surface. The one-way rotating piece (72) can only rotate in one direction along the inflation pipe (3) toward the SF6 gas inflation port (8) of the insulating equipment.

[0036] Furthermore, connecting threads (6) are provided at both ends of the air cavity (71) which are respectively connected to the SF6 gas charging port (8) of the insulating device.

[0037] Furthermore, the inflation tube (3) comprises: an inner layer hose and an outer layer steel braided tube formed by winding double layers of stainless steel wires; the joints at both ends are formed by high-pressure crimping, and the pressure resistance can reach 10 MPa; the joints are firm, reliable and well sealed.

[0038] Furthermore, the capacity of the pipeline cleaning gas recovery cylinder (9) is greater than the total capacity of the gas charging pipe (3).

[0039] Furthermore, valves are installed at both ends of the cleaning pipeline gas recovery cylinder (9), and the gas flow direction and flow rate can be changed by adjusting the valves. Connecting ports are provided at both ends, and pressure gauges and air guide pipes are installed respectively. The pressure gauge is used to monitor the gas pressure in the recovery cylinder.

[0040] The working principle of this utility model is introduced as follows:

[0041] A one-way rotating piece that can rotate in one direction is set at the bottom of the air cavity of the one-way conduction component. The two ends of the air cavity are connected to the pressure reducing valve and the charging port of the SF6 gas insulation equipment to be replenished through connecting threads. When the pressure in the SF6 gas cylinder is higher than the pressure in the SF6 gas insulation equipment to be replenished, when the SF6 gas flows from the gas cylinder to the gas chamber of the equipment through the charging pipe, the high-pressure gas will continuously push the one-way rotating piece open, and the SF6 gas will flow from the gas cylinder to the gas chamber. When there is no gas flowing in the charging pipe, the one-way rotating piece in the one-way conduction component will automatically close by its own weight;

[0042] When the SF6 gas pressure in the SF6 gas insulation equipment to be replenished is higher than the gas pressure in the gas cylinder, the high-pressure gas quickly flows to the one-way rotating piece, which intensifies the close fit between the one-way rotating piece and the valve port, making the one-way conducting component continuously closed, and the high-pressure gas in the gas chamber cannot flow out;

[0043] The capacity of the cleaning pipeline gas recovery cylinder is set slightly larger than the capacity of the charging pipe after calculating the total capacity of the charging pipe. Therefore, it can be ensured that when the pipeline is cleaned, the cleaning pipeline control three-way joint is adjusted to connect the pipeline with the gas guide pipe and the charging pipe pipeline of the SF6 gas cylinder, and then the valve at the end of the cleaning pipeline gas recovery cylinder is adjusted to connect the gas guide pipe and the cleaning pipeline gas recovery cylinder, and then the pressure reducing valve and the pressure gauge are operated to inject SF6 gas into the charging pipe, and almost all the residual gas in the charging pipe is collected in the cleaning pipeline gas recovery cylinder, and the valve at the end of the cleaning pipeline gas recovery cylinder is closed after the charging pipeline cleaning process is completed; the cleaning pipeline gas recovery cylinder is removed, and the charging pipe head is connected to the SF6 gas charging port of the insulating equipment of the gas chamber, and the cleaning pipeline control three-way joint is operated to connect the charging pipe and the one-way guide component, so that the charging pipe pipeline of the SF6 gas cylinder is inflated to the gas chamber, and the SF6 gas insulating equipment to be replenished is filled with qualified SF6 gas.

[0044] Compared with the prior art, the utility model has the following beneficial effects:

[0045] (1) The capacity of the gas recovery cylinder for cleaning the pipeline is set slightly larger than the capacity of the gas filling pipe after calculating the total capacity of the gas filling pipe, and the pressure of the cylinder is lower than the output pressure of the SF6 gas cylinder, so that the gas used for cleaning the pipeline can be recovered; this can not only effectively reduce the emission of SF6 gas, but also improve the utilization efficiency of SF6 gas;

[0046] (2) The one-way rotating piece of the one-way conducting assembly can ensure that the gas in the gas chamber of the SF6 gas-insulated equipment to be replenished does not leak or flow back during the process of live gas replenishment, even if the pipeline bursts, the joint bursts, or the gas cylinder pressure is lower than the gas chamber pressure;

[0047] (3) The steel braided pipe with double-layer stainless steel wire winding and high-pressure crimping improves the protection and anti-aging life extension performance of the inflation pipeline, the anti-leakage performance is more stable and reliable, and the continuous stability of live air replenishment is improved.

[0048] (4) Reduce the harm to the human body caused by operators inhaling toxic and harmful gases. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 This is a schematic diagram of the structure and state transition of the one-way conducting component;

[0050] Figure 2 It is a partial schematic diagram of the connection between the inflation pipe and the connecting thread, the cleaning pipe control tee joint, and the one-way conduction component;

[0051] Figure 3 It is a schematic diagram of the connection structure between the inflation pipe and the inflation port of the insulation equipment;

[0052] Figure 4 It is a schematic diagram of the overall structure of the utility model;

[0053] Explanation of the reference numerals: 1—SF6 gas cylinder, 2—pressure reducing valve and pressure gauge, 3—gas charging pipe, 4—three-way joint, 5—gas guide pipe, 6—connecting thread, 7—one-way guide assembly, 71—gas cavity, 72—one-way rotating plate, 8—SF6 gas charging port of insulating equipment, 9—gas recovery cylinder for cleaning pipeline. DETAILED DESCRIPTION

[0054] In order to make the purpose, technical solution and advantages of the utility model clearer, the utility model is further described in detail below in combination with specific implementation methods and with reference to the accompanying drawings. It should be understood that these descriptions are only exemplary and are not intended to limit the scope of the utility model. In addition, in the following description, the description of well-known structures and technologies is omitted to avoid unnecessary confusion of the concept of the utility model.

[0055] like Figure 1-4 As shown, a gas recovery device for SF6 live filling and filling pipeline cleaning to prevent leakage is installed between the SF6 gas cylinder 1 and the SF6 gas filling port 8 of the insulating equipment as an SF6 transportation channel. The filling and filling pipeline cleaning device includes: a pressure reducing valve and a pressure gauge 2 connected to the SF6 gas cylinder 1, used to reduce the pressure of the high-pressure gas in the SF6 gas cylinder 1 and monitor the pressure; a filling pipe 3 connected between the pressure reducing valve and the pressure gauge 2 and a one-way conducting component 7, used to transport SF6; the one-way conducting component 7 is provided at the filling pipe 3 and the filling interface 8 of the insulating equipment to be filled with gas, used to unidirectionally control SF6 to enter the insulating equipment to be filled with gas only from the filling pipe 3; a cleaning pipeline control three-way joint 4 is provided between the filling pipe 3 and the one-way conducting component 7, used to control the flow direction of SF6 gas; a cleaning pipeline gas recovery cylinder 9 is connected to the cleaning pipeline control three-way joint 4, used to recover SF6 during the cleaning of the filling pipeline;

[0056] The inflatable tube 3 is different from ordinary rubber inflatable tubes. After a period of sun exposure, various fine cracks are prone to appear on the rubber surface. Long-term use will cause risks such as leakage. Based on the inner hose, the steel braided tube is made of double-layer stainless steel wire. The joints at both ends are made of high-pressure crimping, and the pressure resistance can reach 10MPa. The joints are firm, reliable and well sealed, which can greatly reduce the occurrence of cracks on the surface of the inflatable tube after long-term use, extend the service life of the inflatable tube, and at the same time avoid more leakage risks, and improve the safety and reliability of the inflation operation.

[0057] like Figure 1 As shown, the one-way conducting component 7 includes: an air cavity 71, which serves as the main body of the one-way conducting component; a one-way rotating piece 72, which is in the shape of a disc and is arranged at the bottom of the connecting side of the air cavity 71 and the inflation tube 3;

[0058] One side of the one-way rotating piece 72 is connected to the rotating shaft on the air cavity 71, and the protruding part on the other side of the one-way rotating piece 72 overlaps with the flat and smooth valve opening at the bottom of the air cavity 71 to form a flat sealing surface. The one-way rotating piece 72 is in the open state only when the high-pressure SF6 gas flows from the gas cylinder 1 through the filling pipe 3 and the one-way conducting component 7 to the SF6 gas insulation equipment to be replenished. Otherwise, the one-way rotating piece 72 is in the closed state;

[0059] The connecting thread 6 is provided at both ends of the air cavity 71 and is respectively connected to the cleaning pipeline control tee joint 4 and the SF6 gas insulation equipment charging port 8;

[0060] The cleaning pipeline control tee joint 4 is connected at both ends by connecting threads 6, and raw tape is wrapped around the connecting threads 6 to ensure a tight seal; or a quick aviation joint structure is adopted to achieve quick assembly and docking.

[0061] Before filling high-voltage electrical equipment with SF6, in order to ensure the purity of the filled SF6, it is necessary to discharge all the water, moisture and other impurities that may exist in the filling pipe 3. Since discharging SF6 directly into the air does not comply with operating specifications, it will pollute the air and is not conducive to the operators to develop standardized operating habits.

[0062] At the end of the gas charging pipe 3, a cleaning gas recovery cylinder 9 is connected, and the cleaning pipeline gas recovery cylinder interface 5 is compatible with the connection thread 6 interface at the end of the air guide pipe, so as to further deepen the processing of the recovered SF6 gas. When cleaning the pipeline, the cleaning pipeline gas recovery cylinder 9 can be connected to the gas charging pipe 3. Since the capacity of the cleaning pipeline gas recovery cylinder 9 is calculated and set to be slightly larger than the capacity of the gas charging pipe 3, the gas cleaning operation is performed to discharge the gas in the gas charging pipe 3 into the cleaning pipeline gas recovery cylinder 9. When the cleaning pipeline gas recovery cylinder 9 is full, it means that the gas in the gas charging pipe 3 has been completely discharged, that is, the pipeline cleaning operation is completed. Then, the one-way conduction component 7 can be docked with the SF6 air inlet 8 of the high-voltage electrical equipment under a slightly positive pressure, thereby ensuring that the entire air pipe connection process is always in a positive pressure state, thereby preventing dust and moisture from invading. Finally, open the valve for filling operation.

[0063] It should be understood that the above specific embodiments of the present invention are only used to illustrate or explain the principles of the present invention, and do not constitute a limitation on the present invention. Therefore, any modifications, equivalent substitutions, improvements, etc. made without departing from the spirit and scope of the present invention should be included in the protection scope of the present invention. In addition, the claims attached to the present invention are intended to cover all changes and modifications that fall within the scope and boundaries of the attached claims, or the equivalent forms of such scope and boundaries.

Claims

1. A gas recovery device for SF6 live filling and gas pipeline cleaning to prevent gas leakage, characterized in that: It is installed between the SF6 gas cylinder (1) and the SF6 gas filling port (8) of the insulating equipment and is used for filling the SF6 transmission channel and cleaning the filling pipeline. It includes: A pressure reducing valve and a pressure gauge (2) connected to the SF6 gas cylinder (1) for reducing the pressure of the high-pressure gas in the SF6 gas cylinder (1) and monitoring the pressure; A charging pipe (3), one end of which is connected to the pressure reducing valve and the pressure gauge (2), and the other end of which is used to connect to the SF6 gas charging port (8) of the insulating equipment for charging SF6; The one-way guide assembly (7) and the cleaning pipeline control three-way joint (4) are sequentially installed at the end of the gas charging pipe (3); the upper and lower ends of the cleaning pipeline control three-way joint (4) are respectively connected to the gas charging pipe and the one-way guide assembly (7); and the side end is connected to the cleaning pipeline gas recovery cylinder (9) through the gas guide pipe; The one-way conducting component (7) is arranged at the end of the gas filling pipe (3) and is used to one-way control SF6 so that it can only enter the insulating equipment to be filled with gas from the gas filling pipe (3); The cleaning pipeline gas recovery cylinder (9) is connected to the cleaning pipeline control three-way joint (4) through a gas guide pipe and is used to recover SF6 during the cleaning of the charging pipeline.

2. A gas recovery device for anti-leakage SF6 live filling and filling pipeline cleaning according to claim 1, characterized in that: The one-way conducting component (7) comprises: The air cavity (71), serving as the main body of the one-way conducting component (7), has two openings, an upper opening and a lower opening; The one-way rotating piece (72) is in the shape of a disc and is arranged at the bottom of the connection side between the air cavity (71) and the inflation tube (3); the one-way rotating piece (72) can only rotate from bottom to top to open the lower opening.

3. A gas recovery device for anti-leakage SF6 live filling and gas filling pipeline cleaning according to claim 2, characterized in that: One side of the one-way rotating piece (72) is connected to the rotating shaft on the air cavity (71), and the protruding portion on the other side of the one-way rotating piece (72) overlaps with the flat and smooth valve opening at the bottom of the air cavity (71) to form a planar sealing surface. The one-way rotating piece (72) can only rotate in one direction along the inflation pipe (3) toward the SF6 gas inflation port (8) of the insulating device.

4. A gas recovery device for anti-leakage SF6 live filling and gas filling pipeline cleaning according to claim 2, characterized in that: Connecting threads (6) are provided at both ends of the air cavity (71) that are connected to the SF6 gas charging port (8) of the insulating equipment.

5. The gas recovery device for anti-leakage SF6 live filling and filling pipeline cleaning according to claim 1 is characterized in that: The inflation tube (3) comprises an inner layer soft tube and an outer layer steel braided tube formed by winding double layers of stainless steel wires, and the joints at both ends are formed by high-pressure crimping.

6. The gas recovery device for anti-leakage SF6 live filling and gas filling pipeline cleaning according to claim 1 is characterized in that: The capacity of the pipeline cleaning gas recovery cylinder (9) is greater than the total capacity of the gas charging pipe (3).

7. The gas recovery device for anti-leakage SF6 live filling and filling pipeline cleaning according to claim 1 is characterized in that: The cleaning pipeline gas recovery cylinder (9) is provided with valves at both ends, and the gas flow direction and flow rate can be changed by adjusting the valves. Connecting threads are provided at both ends, and pressure gauges and gas guide pipes are installed respectively. The pressure gauge is used to monitor the gas pressure in the recovery cylinder.

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