SF6 gas filling and pressurizing device

Abstract

The invention is applicable to the field of gaseous liquefaction, and provides an SF6 gas filling and pressurizing device which comprises a pressure tank, sealing mechanisms are arranged at the front end and the rear end of the pressure tank, a sulfur hexafluoride liquefaction mechanism is arranged in the pressure tank, and an air inlet valve and an air outlet valve are arranged on the side wall of the pressure tank. The ends of the air inlet valve and the air outlet valve are respectively connected with a circulating air pipe; a quantitative pipe is arranged at the bottom of the pressure box, the top end of the quantitative pipe is communicated with the bottom of the pressure box in a sealed mode, and a constant-pressure hose is arranged at the bottom end of the quantitative pipe. When the sulfur hexafluoride gas treatment device is used, sulfur hexafluoride gas to be treated is introduced into the gas inlet valve, redundant gas in the pressure box is discharged from the gas outlet valve and recycled, meanwhile, the two cooling connectors are communicated with circulating liquid nitrogen, the liquid nitrogen starts to absorb heat of the sulfur hexafluoride gas after penetrating through the heat exchange coil, and the heat of the sulfur hexafluoride gas is recovered. The sulfur hexafluoride gas can be condensed into liquid at the standard atmospheric pressure and the temperature of minus 63 DEG C, so that sulfur hexafluoride substances can be conveniently collected in the pressure box.

Description

Technical Field

[0001] The present invention belongs to the field of gaseous liquefaction, and particularly relates to an SF6 gas charging and pressurizing device. Background Art

[0002] With the development of industrial technology, modern gaseous liquefaction technology has become increasingly perfect. Sulfur hexafluoride belongs to an inert gas with extremely stable chemical properties. Sulfur hexafluoride gas can still maintain extremely high stability in a high-temperature environment and can be used for arc extinguishing in circuit systems. A gas liquefaction device and a gas liquefaction method using the gas liquefaction device that can supply high-pressure natural gas in a device for efficiently liquefying a raw material gas by using the cold energy of liquefied natural gas disclosed in Patent CN113330263B. This gas liquefaction device includes: a main heat exchanger that cools the raw material gas compressed by a first compressor; a first pressure reducing valve that decompresses and cools the raw material gas; a gas-liquid separator that separates the raw material gas discharged from the first pressure reducing valve into gas and liquid; a first pump that pressurizes the liquefied natural gas to a first pressure; and a second pump that pressurizes the liquefied natural gas to a second pressure higher than the first pressure. Among them, heat exchange is performed in the main heat exchanger between the raw material gas on the one hand and the liquefied natural gas pressurized by the first pump and the liquefied natural gas pressurized by the second pump on the other hand. This device still has defects when in use. First, the treatment method of liquefied natural gas is not good enough. The pressure of liquefied natural gas is relatively high, which requires high sealing and anti-pressure performance of the pipe body, resulting in a gas leakage failure during the gas treatment process. Second, it is difficult to control the injection amount of gas by the conventional pressurizing and charging device, and the amount of injected gas is prone to fluctuate, resulting in inaccurate gas transportation. Summary of the Invention

[0003] The purpose of the present invention is to provide an SF6 gas charging and pressurizing device in view of the deficiencies of the prior art. When this device is in use, the sulfur hexafluoride gas to be treated is introduced into the intake valve, and the excess gas inside the pressure tank is discharged from the outlet valve and recycled. At the same time, two cooling interfaces are connected to circulating liquid nitrogen. After the liquid nitrogen passes through the heat exchange coil, it begins to absorb the heat of the sulfur hexafluoride gas. The sulfur hexafluoride gas can be condensed into a liquid at standard atmospheric pressure and minus 63 degrees Celsius, which is convenient for collecting the sulfur hexafluoride substance inside the pressure tank. If there is no liquid nitrogen, other cooling substances can be introduced into the heat exchange coil. If the temperature of the cooling substance is higher than minus 63 degrees Celsius, the threshold value of the surplus gas pressure of the outlet valve is increased, and then the sulfur hexafluoride can become a liquid under high pressure and above minus 63 degrees Celsius, so as to solve the problems mentioned in the background art.

[0004] To solve the above problems, the present invention provides the following technical solution: An SF6 gas charging and pressurizing device, including a pressure tank, sealed mechanisms are provided at both the front and rear ends of the pressure tank, a sulfur hexafluoride liquefaction mechanism is provided inside the pressure tank, an intake valve and an outlet valve are provided on the side wall of the pressure tank, and a circulation gas pipe is connected to the ends of the intake valve and the outlet valve; a metering pipe is provided at the bottom of the pressure tank, the top end of the metering pipe is hermetically connected to the bottom of the pressure tank, a constant pressure hose is provided at the bottom end of the metering pipe, an inflator is provided at the bottom end of the constant pressure hose, a metering mechanism is provided inside the metering pipe, a heating mechanism is provided in the side wall of the constant pressure hose, and an inflation mechanism is provided inside the inflator; the sulfur hexafluoride liquefaction mechanism includes a heat exchange coil fixedly provided inside the pressure tank, heat exchange tiles are provided on the side wall of the heat exchange coil, circulation pipes are provided at both ends of the heat exchange coil, the ends of the circulation pipes extend to the outside of the pressure tank, and cooling interfaces are provided at the ends of the circulation pipes, and the two cooling interfaces are connected to circulating liquid nitrogen.

[0005] During use, the sulfur hexafluoride gas to be processed is introduced into the intake valve, and the excess air pressure inside the pressure tank is discharged from the outlet valve and recovered. At the same time, the two cooling interfaces are connected to the circulating liquid nitrogen. After the liquid nitrogen passes through the heat exchange coil, it begins to absorb the heat of the sulfur hexafluoride gas. The sulfur hexafluoride gas can be condensed into a liquid at standard atmospheric pressure and minus 63 degrees Celsius, which is convenient for collecting the sulfur hexafluoride substance inside the pressure tank.

[0006] Further, the sealed mechanism includes two sealed covers, and the sealed covers are hermetically sealed at the front and rear ports of the pressure tank.

[0007] During use, if there is no liquid nitrogen, other cooling substances can be introduced into the heat exchange coil. If the temperature of the cooling substance is higher than minus 63 degrees Celsius, the threshold value of the beneficial gas pressure of the outlet valve is increased, and then the sulfur hexafluoride of the outlet valve can become a liquid under high pressure and above minus 63 degrees Celsius.

[0008] Further, the side walls of the pressure tank and the sealed cover are of a double-layer structure, the internal voids of the pressure tank and the sealed cover are evacuated, and several support members are provided in the internal voids of the pressure tank and the sealed cover. The support members include heat insulation blocks, and the material of the heat insulation blocks is polystyrene. The two ends of the heat insulation blocks are thick and the middle is thin.

[0009] During use, evacuating the internal voids of the pressure tank and the sealed cover has a good heat insulation effect, and polystyrene has a supporting effect to prevent the internal voids of the pressure tank and the sealed cover from being flattened.

[0010] Further, the heat exchange tile includes a copper sheet, and heat conduction perforations matching the heat exchange coil are arranged on the copper sheet. Air blowers are arranged at the front and rear ends of the heat exchange coil, and the air flow channels of the two air blowers pass through the gap between the center of the heat exchange coil and the copper sheet.

[0011] During use, the air blower drives air flow to pass through the heat exchange coil and the copper sheet to transfer heat. After the heat of sulfur hexafluoride is taken away, it can be liquefied and condensed on the surfaces of the heat exchange coil and the copper sheet and collected at the bottom of the pressure tank.

[0012] Further, the metering mechanism includes several layers of inner tank tiles inside the metering tube. The shape of each layer of inner tank tile is a cylindrical tube. An inlet valve is arranged at the top of the metering tube, and an outlet valve is arranged at the lower end of the metering tube. The inlet valve is connected to the inside of the pressure tank, and the outlet valve is connected to the constant pressure hose.

[0013] During use, when the inlet valve is opened, liquid sulfur hexafluoride enters the inside of the metering tube. Then, the total amount of the liquid sulfur hexafluoride is relatively accurate, which is convenient for subsequent quantitative discharge. If it is necessary to change the internal volume of the metering tube, the inner tank tiles can be added or removed.

[0014] Further, the heating mechanism includes heating wires in the side walls of the metering tube and the constant pressure hose.

[0015] During use, after the inside of the metering tube is filled with liquid sulfur hexafluoride, the inlet valve is locked, and then the outlet valve is fully opened and the liquid sulfur hexafluoride is heated. At this time, the liquid sulfur hexafluoride can be completely turned into gas and discharged from the inflator.

[0016] Further, the inflation mechanism includes a telescopic head inside the inflator. A sliding channel that is hermetically fitted with the telescopic head is arranged inside the inflator. The sliding channel of the inflator is a double-layer sandwich structure. An array of linear exhaust holes is arranged on the inner layer of the sliding channel. A docking wire groove that is docked with the exhaust holes is arranged on the side wall of the telescopic head. An injection head is arranged at the end of the telescopic head facing away from the inflator. A blocking mechanism is arranged at the port of the sliding channel. A lifting handle is arranged on the outer side wall of the inflator. The inner end of the telescopic head and the inner side wall of the sliding channel are connected by a return spring.

[0017] During use, when the staff holds the lifting handle, the injection head is aligned with the air inlet of the electrical box and pressed. When the docking wire groove on the side wall of the telescopic head is docked with the exhaust holes, gas can be discharged from the injection head. The rate of gas discharge depends on how many exhaust holes the docking wire groove is docked with.

[0018] Further, the blocking mechanism includes a limiting ring at the port of the sliding channel, and the limiting ring is fixed to the port of the sliding channel by bolts.

[0019] During use, the limit ring can prevent the telescopic head from falling off.

[0020] Compared with the prior art, the embodiments of the present application mainly have the following beneficial effects: Firstly, when the device is in use, the sulfur hexafluoride gas to be processed is introduced into the intake valve. The excess gas inside the pressure tank is discharged and recycled through the outlet valve. At the same time, the two cooling interfaces are connected to the circulating liquid nitrogen. After the liquid nitrogen passes through the heat exchange coil, it begins to absorb the heat of the sulfur hexafluoride gas. The sulfur hexafluoride gas can condense into a liquid at a standard atmospheric pressure and minus 63 degrees Celsius, which is convenient for collecting the sulfur hexafluoride substance inside the pressure tank. In the absence of liquid nitrogen, other cooling substances can be introduced into the heat exchange coil. If the temperature of the cooling substance is higher than minus 63 degrees Celsius, the threshold value of the excess gas pressure of the outlet valve is increased. Then, the sulfur hexafluoride can become a liquid under high pressure and above minus 63 degrees Celsius.

[0021] Secondly, when the liquid inlet valve is opened, the liquid sulfur hexafluoride enters the metering tube. After the metering tube is filled with liquid sulfur hexafluoride, the liquid inlet valve is locked, and then the liquid outlet valve is fully opened and the liquid sulfur hexafluoride is heated. At this time, the liquid sulfur hexafluoride can completely turn into gas and be discharged from the inflator. When the staff holds the lifting handle, the injection head is aligned with the air inlet of the electrical box and pressed. When the docking wire groove on the side wall of the telescopic head is docked with the exhaust holes, the gas can be discharged from the injection head. The rate of gas discharge depends on how many exhaust holes the docking wire groove is docked with. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a front view schematic diagram of the present invention.

[0023] Figure 2 It is a bottom view schematic diagram of the present invention.

[0024] Figure 3 It is a sectional view schematic diagram of the pressure tank of the present invention.

[0025] Figure 4 It is a schematic diagram of the heat exchange coil of the present invention.

[0026] Figure 5 It is a schematic diagram of the metering tube of the present invention.

[0027] Figure 6 It is a schematic diagram of the inflator of the present invention.

[0028] Figure 7 It is a sectional view schematic diagram of the inflator of the present invention.

[0029] Figure 8 For the present invention Figure 7 Partial enlarged view of A.

[0030] Figure 9 Schematic diagram of the heat insulation block of the present invention.

[0031] Description of reference numerals: Pressure tank 1, airtight cover plate 101, heat insulation block 102, metering tube 2, liquid inlet valve 201, liquid outlet valve 202, inner tank tile 203, constant pressure hose 3, air pump 4, lifting handle 401, limit ring 402, air inlet valve 5, air outlet valve 501, circulation air pipe 502, cooling interface 6, fan 7, heat exchange coil 8, circulation pipe 801, copper sheet 802, telescopic head 9, docking wire groove 901, injection head 902, return spring 10, exhaust hole 1001. Detailed implementation manners

[0032] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terms used in the description of this application in the specification are only for the purpose of describing specific embodiments, and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the description and claims of this application and the above drawings are intended to cover non-exclusive inclusion. The terms "first", "second", etc. in the description and claims of this application or the above drawings are used to distinguish different objects, not to describe a specific order.

[0033] Reference to "embodiment" herein means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of this application. The phrase appears in various places in the specification and does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art will explicitly and implicitly understand that the embodiments described herein can be combined with other embodiments.

[0034] The present invention provides an SF6 gas charging and pressurizing device, such as Figures 1-9As shown in the figure, it includes a pressure tank 1. Sealing mechanisms are provided at both the front and rear ends of the pressure tank 1. A sulfur hexafluoride liquefaction mechanism is arranged inside the pressure tank 1. An intake valve 5 and an outlet valve 501 are provided on the side wall of the pressure tank 1. The ends of the intake valve 5 and the outlet valve 501 are each connected to a circulation gas pipe 502. A metering pipe 2 is arranged at the bottom of the pressure tank 1. The top end of the metering pipe 2 is hermetically connected to the bottom of the pressure tank 1. A constant-pressure hose 3 is arranged at the bottom end of the metering pipe 2. An air inflation cylinder 4 is arranged at the bottom end of the constant-pressure hose 3. A metering mechanism is arranged inside the metering pipe 2. A heating mechanism is arranged in the side wall of the constant-pressure hose 3. An air inflation mechanism is arranged inside the air inflation cylinder 4. The sulfur hexafluoride liquefaction mechanism includes a heat exchange coil 8 fixedly arranged inside the pressure tank 1. Heat exchange tiles are arranged on the side wall of the heat exchange coil 8. Both ends of the heat exchange coil 8 are provided with circulation pipes 801. The ends of the circulation pipes 801 extend to the outside of the pressure tank 1, and cooling interfaces 6 are arranged at the ends of the circulation pipes 801. The two cooling interfaces 6 are connected to circulating liquid nitrogen.

[0035] In this embodiment, the sulfur hexafluoride gas to be processed is introduced into the intake valve 5. The excess gas inside the pressure tank 1 is discharged from the outlet valve 501 and recycled. At the same time, the two cooling interfaces 6 are connected to the circulating liquid nitrogen. After the liquid nitrogen passes through the heat exchange coil 8, it starts to absorb the heat of the sulfur hexafluoride gas. The sulfur hexafluoride gas can be condensed into a liquid at standard atmospheric pressure and minus 63 degrees Celsius, which is convenient for collecting the sulfur hexafluoride substance inside the pressure tank 1.

[0036] In a further embodiment of the present invention, as Figures 1-3 shown, the sealing mechanism includes two sealing covers 101, and the sealing covers 101 hermetically seal the ports at the front and rear of the pressure tank 1.

[0037] In this embodiment, if there is no liquid nitrogen, other cooling substances can be introduced into the heat exchange coil 8. If the temperature of the cooling substance is higher than minus 63 degrees Celsius, the threshold value of the excess pressure of the outlet valve 501 is increased, and then the sulfur hexafluoride can become a liquid under high pressure and at a temperature higher than minus 63 degrees Celsius.

[0038] In a further embodiment of the present invention, as Figure 9 shown, the side walls of the pressure tank 1 and the sealing covers 101 are of a double-layer structure. The internal voids of the pressure tank 1 and the sealing covers 101 are evacuated to a vacuum. A number of support members are arranged in the internal voids of the pressure tank 1 and the sealing covers 101. The support members include heat insulation blocks 102. The material of the heat insulation blocks 102 is polystyrene. The two ends of the heat insulation blocks 102 are thick and the middle is thin.

[0039] In this embodiment, evacuating the internal space between the pressure tank 1 and the airtight cover plate 101 to a vacuum has a good heat insulation effect. Polystyrene has a supporting effect and can prevent the internal space between the pressure tank 1 and the airtight cover plate 101 from being flattened.

[0040] In a further embodiment of the present invention, as Figures 1-4 shown, the heat exchange tile includes a copper sheet 802. Heat conduction perforations matching the heat exchange coil 8 are provided on the copper sheet 802. Air blower 7s are provided at the front and rear ends of the heat exchange coil 8, and the air flow channels of the two air blower 7s pass through the center of the heat exchange coil 8 and the gap of the copper sheet 802.

[0041] In this embodiment, the air blower 7 drives air flow to pass through the heat exchange coil 8 and the copper sheet 802 to transfer heat. After the heat of sulfur hexafluoride is taken away, it can be condensed into a liquid state on the surfaces of the heat exchange coil 8 and the copper sheet 802 and collected at the bottom of the pressure tank 1.

[0042] In a further embodiment of the present invention, as Figures 1-5 shown, the metering mechanism includes several layers of inner tank tiles 203 inside the metering tube 2. The shape of each layer of inner tank tile 203 is a cylindrical tube. A liquid inlet valve 201 is provided at the top of the metering tube 2, and a liquid outlet valve 202 is provided at the lower end of the metering tube 2. The liquid inlet valve 201 is connected to the inside of the pressure tank 1, and the liquid outlet valve 202 is connected to the constant pressure hose 3.

[0043] In this embodiment, when the liquid inlet valve 201 is opened, liquid sulfur hexafluoride enters the inside of the metering tube 2. Thus, the total amount of the liquid sulfur hexafluoride is relatively accurate, which is convenient for subsequent quantitative discharge. When it is necessary to change the internal volume of the metering tube 2, the inner tank tiles 203 can be installed or removed.

[0044] In a further embodiment of the present invention, as Figures 1-5 shown, the heating mechanism includes heating wires in the side walls of the metering tube 2 and the constant pressure hose 3.

[0045] In this embodiment, after the inside of the metering tube 2 is filled with liquid sulfur hexafluoride, the liquid inlet valve 201 is locked, and then the liquid outlet valve 202 is fully opened and the liquid sulfur hexafluoride is heated. At this time, the liquid sulfur hexafluoride can be completely turned into a gas state and discharged from the inflator 4.

[0046] In a further embodiment of the present invention, as Figures 6-8As shown, the inflation mechanism includes a telescopic head 9 inside an inflation cylinder 4. There is a sliding channel inside the inflation cylinder 4 that fits tightly and airtightly with the telescopic head 9. The sliding channel of the inflation cylinder 4 is a double-layer sandwich mechanism. There are exhaust holes 1001 arranged in a linear array on the inner layer of the sliding channel. There is a docking wire groove 901 on the side wall of the telescopic head 9 that docks with the exhaust holes 1001. One end of the telescopic head 9 facing away from the inflation cylinder 4 is provided with an injection head 902. A blocking mechanism is provided at the port of the sliding channel. There is a lifting handle 401 on the outer side wall of the inflation cylinder 4. The inner end of the telescopic head 9 and the inner side wall of the sliding channel are connected by a return spring 10.

[0047] In this embodiment, when a staff member holds the lifting handle 401, align the injection head 902 with the air inlet of the electrical box and press. When the docking wire groove 901 on the side wall of the telescopic head 9 docks with the exhaust holes 1001, gas can be discharged from the injection head 902. The rate of gas discharge depends on how many exhaust holes 1001 the docking wire groove 901 docks with.

[0048] In a further embodiment of the present invention, as Figures 6-8 shown, the blocking mechanism includes a limiting ring 402 at the port of the sliding channel. The limiting ring 402 is fixed to the port of the sliding channel by bolts.

[0049] In this embodiment, the limiting ring 402 can prevent the telescopic head 9 from falling off.

[0050] It should be noted that for the foregoing embodiments, for the sake of simple description, they are all expressed as a series of action combinations. However, those skilled in the art should know that the present invention is not limited by the described action sequence, because according to the present invention, certain steps may be in other sequences or carried out simultaneously. Secondly, those skilled in the art should also know that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily essential to the present invention.

[0051] In several embodiments provided by the present application, it should be understood that the disclosed device can be implemented in other ways. For example, the device embodiments described above are only illustrative. For example, the above division of units can have other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point, the displayed or discussed coupling or communication connection between each other can be through some interfaces. The indirect coupling or communication connection between devices or units can be in the form of telecommunications or other forms.

[0052] The units described above as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or may be distributed over multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0053] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the protection scope of the invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on these embodiments, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention. Although the present invention has been described in detail with reference to the above embodiments, those of ordinary skill in the art can still, without conflict and without creative efforts, combine, add or delete the features in the embodiments of the present invention according to the circumstances, or make other adjustments, so as to obtain different technical solutions that essentially do not deviate from the concept of the present invention, and these technical solutions also belong to the scope of protection of the present invention.

Claims

1. An SF6 gas charging and pressurizing device, characterized in that: It includes a pressure tank (1), with sealing mechanisms provided at both the front and rear ends of the pressure tank (1). A sulfur hexafluoride liquefaction mechanism is provided inside the pressure tank (1). An intake valve (5) and an outlet valve (501) are provided on the side wall of the pressure tank (1). The ends of the intake valve (5) and the outlet valve (501) are each connected to a circulation gas pipe (502). A metering pipe (2) is provided at the bottom of the pressure tank (1). The top end of the metering pipe (2) is hermetically connected to the bottom of the pressure tank (1). A constant-pressure hose (3) is provided at the bottom end of the metering pipe (2). An inflator (4) is provided at the bottom end of the constant-pressure hose (3). A metering mechanism is provided inside the metering pipe (2). A heating mechanism is provided in the side wall of the constant-pressure hose (3). An inflation mechanism is provided inside the inflator (4). The sulfur hexafluoride liquefaction mechanism includes a heat exchange coil (8) fixedly provided inside the pressure tank (1). Heat exchange tiles are provided on the side wall of the heat exchange coil (8). Both ends of the heat exchange coil (8) are provided with circulation pipes (801). The ends of the circulation pipes (801) extend outside the pressure tank (1), and cooling interfaces (6) are provided at the ends of the circulation pipes (801). The two cooling interfaces (6) are connected to circulating liquid nitrogen.

2. The SF6 gas charging and pressurizing device according to claim 1, wherein: The sealing mechanism includes two sealing covers (101), which hermetically seal the ports at the front and rear of the pressure tank (1).

3. The SF6 gas charging and pressurizing device according to claim 2, wherein: The side walls of the pressure tank (1) and the sealing covers (101) are of a double-layer structure. The internal voids of the pressure tank (1) and the sealing covers (101) are evacuated to a vacuum. A number of support members are provided in the internal voids of the pressure tank (1) and the sealing covers (101). The support members include heat insulation blocks (102), the material of the heat insulation blocks (102) is polystyrene, and both ends of the heat insulation blocks (102) are thick and the middle is thin.

4. A SF6 gas charging and pressurizing device according to claim 1, characterized in that: The heat exchange tiles include copper sheets (802). Heat conduction perforations matching the heat exchange coil (8) are provided on the copper sheets (802). Fans (7) are provided at both the front and rear ends of the heat exchange coil (8). The air flow channels of the two fans (7) pass through the center of the heat exchange coil (8) and the gap of the copper sheets (802).

5. A SF6 gas charging and pressurizing device according to claim 1, characterized in that: The metering mechanism includes several layers of inner tank tiles (203) inside the metering pipe (2). The shape of each layer of inner tank tile (203) is a cylindrical tube. An inlet valve (201) is provided at the top end of the metering pipe (2). An outlet valve (202) is provided at the lower end of the metering pipe (2). The inlet valve (201) is connected to the inside of the pressure tank (1). The outlet valve (202) is connected to the constant-pressure hose (3).

6. The SF6 gas charging and pressurizing device according to claim 1, characterized in that: The heating mechanism includes electric heating wires in the side walls of the metering pipe (2) and the constant-pressure hose (3).

7. The SF6 gas charging and pressurizing device according to claim 1, characterized in that: The inflation mechanism includes a telescopic head (9) inside an inflation cylinder (4). A sliding channel that is hermetically fitted with the telescopic head (9) is provided inside the inflation cylinder (4). The sliding channel of the inflation cylinder (4) is a double-layer sandwich mechanism. An array of linear exhaust holes (1001) is provided on the inner layer of the sliding channel. A docking wire groove (901) that is docked with the exhaust holes (1001) is provided on the side wall of the telescopic head (9). An injection head (902) is provided at one end of the telescopic head (9) facing away from the inflation cylinder (4). A blocking mechanism is provided at the port of the sliding channel. A lifting handle (401) is provided on the outer side wall of the inflation cylinder (4). The inner end of the telescopic head (9) and the inner side wall of the sliding channel are connected by a return spring (10).

8. The SF6 gas charging and pressurizing device according to claim 7, characterized in that: The blocking mechanism includes a limiting ring (402) at the port of the sliding channel. The limiting ring (402) is fixed to the port of the sliding channel by bolts.

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