Sulfur hexafluoride mixing, sampling and enriching device and method

Abstract

The embodiment of the invention discloses a sulfur hexafluoride mixed sampling enrichment device and method, and relates to the technical field of high voltage and ultrahigh voltage. The sulfur hexafluoride mixing, sampling and enriching device comprises a gas inlet pipe, a gas inlet valve, a pipeline, a first valve, a gas mixing bottle, a semiconductor low-temperature cold trap, a first gas outlet pipe, a first gas outlet valve, a plurality of second valves and a plurality of gas collecting bottles, the gas inlet pipe is communicated with a gas inlet end, the gas mixing bottle is communicated with a first branch pipe, each second branch pipe is communicated with each gas collecting bottle, and each second branch pipe is communicated with each semiconductor low-temperature cold trap. The semiconductor low-temperature cold trap is fixed on the gas mixing bottle, the first gas outlet pipe is communicated with the gas mixing bottle through the first gas outlet valve, the plurality of gas collection bottles are arranged, a plurality of sulfur hexafluoride inflation devices can be sampled, gas in the plurality of sampled gas collection bottles is mixed into the gas mixing bottle, and only mixed samples need to be detected in a laboratory, so that the detection time is greatly shortened, and the detection efficiency is improved. Therefore, the troubleshooting time is saved.

Description

Technical Field

[0001] This invention relates to the field of high voltage and ultra-high voltage electrical technology, and in particular to a sulfur hexafluoride mixed sampling and enrichment device and method. Background Technology

[0002] With the development of high-voltage and ultra-high-voltage electrical technology in my country, SF6 (sulfur hexafluoride) gas has been widely used as an insulating medium for related high-voltage and ultra-high-voltage electrical equipment. Under partial discharge and current-carrying overheating conditions, the sulfur and fluoride ions released from the decomposition of SF6 gas undergo complex chemical reactions with the electrode materials, insulating materials, seals, and air and moisture entering the equipment, producing a series of characteristic gases that characterize equipment faults, such as SO2, H2S, SOF2, SO2F2, HF, CF4, CO, and CO2. Ensuring the safety, stability, and reliability of SF6 equipment and reducing operational risks is one of the key tasks of substation operation and maintenance. SF6 gas decomposition product detection is a crucial means of effectively assessing the internal condition of equipment without disassembling it. Therefore, analyzing the composition and content of SF6 decomposition products is an important method for effective fault diagnosis and preventive maintenance of electrical equipment.

[0003] Currently, SF6 decomposition products are generally detected using electrochemical sensors. This method is fast, but its accuracy is not high. Therefore, DL / T1359 requires the addition of laboratory testing, which requires on-site sampling and bringing the samples back to the laboratory.

[0004] After on-site gas sampling, each sample needs to be analyzed in the laboratory. This makes it impossible to quickly test multiple samples simultaneously, and it also makes it difficult to quickly provide results when troubleshooting equipment malfunctions, thus wasting time. Summary of the Invention

[0005] Therefore, it is necessary to provide a sulfur hexafluoride mixed sampling and enrichment device and method, which aims to solve the problems of needing to analyze each sample in the laboratory after on-site gas sampling, the inability to quickly complete the simultaneous detection of multiple samples, the inability to quickly provide results during equipment fault diagnosis, the inability to quickly find the faulty gas chamber, and the waste of time; at the same time, it can enrich faulty gases such as sulfur dioxide in the gas, thereby improving the detection sensitivity.

[0006] In a first aspect, the present invention provides a sulfur hexafluoride mixed sampling and enrichment device, the sulfur hexafluoride mixed sampling and enrichment device comprising: an inlet pipe, an inlet valve, a pipeline, a first valve, a mixed gas bottle, a semiconductor cryogenic cold trap, a first outlet pipe, a first outlet valve, a plurality of second valves, and a plurality of gas collection bottles. The pipeline includes an inlet end, a first branch pipe, and multiple second branch pipes. The inlet pipe is connected to the inlet end and is equipped with an inlet valve for opening or closing the inlet pipe. The gas mixing bottle is connected to the first branch pipe, and the first valve is installed on the first branch pipe for opening or closing the gas mixing bottle. Each second branch pipe is sequentially arranged between the inlet end and the first branch pipe and is connected to each gas collecting bottle. Each second valve is installed on each second branch pipe for opening or closing the gas collecting bottle. The semiconductor cryogenic cold trap is fixed to the gas mixing bottle and is used to cool the gas mixing bottle. The first outlet pipe is connected to the gas mixing bottle through the first outlet valve.

[0007] In one embodiment, the sulfur hexafluoride mixed sampling enrichment device further includes a plurality of second gas outlet pipes and a plurality of second gas outlet valves, each of the second gas outlet pipes being connected to each of the gas collection bottles, and each of the second gas outlet valves being installed on each of the second gas outlet pipes and used to open or close the second gas outlet pipes.

[0008] In one embodiment, the sulfur hexafluoride mixed sampling and enrichment device further includes a vacuum pump, which is disposed between the inlet end and the second branch pipe, and is connected to the pipeline and used for evacuation.

[0009] In one embodiment, the sulfur hexafluoride mixed sampling and enrichment device further includes a pressure gauge installed in the pipeline and located between the gas inlet and the vacuum pump. The pressure gauge is used to detect the pressure of the gas collection bottle and the vacuum level of the vacuum pump.

[0010] In one embodiment, the sulfur hexafluoride mixed sampling enrichment device further includes a gas washing bottle and a third valve. The pipeline also includes an outlet end and a third branch pipe. The third branch pipe is connected to the outlet end and the gas washing bottle. The third valve is installed on the third branch pipe and is used to open or close the gas washing bottle.

[0011] In one embodiment, the sulfur hexafluoride mixed sampling enrichment device further includes a third gas outlet pipe and a third gas outlet valve. The third gas outlet pipe is connected to the gas washing bottle, and the third gas outlet valve is installed on the third gas outlet pipe and is used to open or close the third gas outlet pipe.

[0012] In one embodiment, the sulfur hexafluoride mixed sampling enrichment device further includes a housing with a accommodating space, wherein the inlet pipe, the inlet valve, the pipeline, the first valve, the mixed gas bottle, the semiconductor cryogenic cold trap, the first outlet pipe, the first outlet valve, a plurality of second valves and a plurality of gas collection bottles are all installed in the accommodating space.

[0013] In one embodiment, the sulfur hexafluoride mixed sampling and enrichment device further includes a leak alarm installed within the containment space and used to detect sulfur hexafluoride gas.

[0014] In one embodiment, the inner wall of each gas collecting bottle is coated with a passivation coating, and the inner wall of the gas mixing bottle is coated with a passivation coating.

[0015] Secondly, the present invention also provides a sulfur hexafluoride mixed sampling enrichment method, the sulfur hexafluoride mixed sampling enrichment method comprising the sulfur hexafluoride mixed sampling enrichment device of any of the above embodiments, the method comprising the following steps: Before sampling, turn on the vacuum pump, press the inlet valve, the first valve, the second valve and the third valve to evacuate the gas collecting bottle, the gas mixing bottle and the gas washing bottle to remove air and residual sulfur hexafluoride decomposition products from the pipeline and the gas collecting bottle, the gas mixing bottle and the gas washing bottle, and then turn off the vacuum pump; Connect the inlet pipe to the sulfur hexafluoride filling device, press the third valve, and the sulfur hexafluoride gas enters the gas washing bottle through the pipeline and the third branch pipe to flush the pipeline and recover the waste gas; Pressing the second valve allows sulfur hexafluoride from the sulfur hexafluoride filling device to slowly enter the gas collecting bottle. Once the pressure reading on the pressure gauge matches the pressure of the sulfur hexafluoride filling device, the bottle is considered full. Repeat the above steps, pressing the second valve sequentially to complete gas sampling from each gas collecting bottle. After sampling is completed, press the first valve first, and then press each of the second valves simultaneously. The gas in each gas collecting bottle enters the gas mixing bottle, and the gas mixing is completed. Turn on the semiconductor cryogenic cold trap switch, and the temperature drops to -60 to -64°C. At this time, most of the SF6 becomes solid. Open the first vent valve and extract the enriched SF6 decomposition products through the first vent pipe. During testing, the sample in the gas mixing bottle is tested first. If it contains sulfur hexafluoride decomposition products, the gas sample in the gas collecting bottle is tested sequentially.

[0016] Implementing the embodiments of the present invention will have the following beneficial effects: The sulfur hexafluoride (SF6) mixed sampling and enrichment device and method of the present invention includes an inlet pipe connected to an inlet end with an inlet valve for opening or closing the inlet pipe. A mixed gas bottle is connected to a first branch pipe, with a first valve installed on the first branch pipe for opening or closing the mixed gas bottle. Second branch pipes are sequentially arranged between the inlet end and the first branch pipe and connected to each gas collection bottle. Second valves are installed on each second branch pipe for opening or closing the gas collection bottle. A semiconductor cryogenic cold trap is fixed to the mixed gas bottle for cooling. A first outlet pipe is connected to the mixed gas bottle through a first outlet valve. By setting multiple gas collection bottles, multiple SF6 filling devices can be sampled, and the gases from the multiple sampled gas collection bottles are mixed into the mixed gas bottle. In the laboratory, only the mixed sample needs to be tested, greatly shortening the testing time and saving troubleshooting time. After most of the sulfur hexafluoride background gas is removed by cryogenic liquefaction in a semiconductor cryogenic cold trap, the concentration of fault gases (sulfur dioxide, hydrogen sulfide, etc.) is concentrated. During laboratory testing, the sensitivity of fault gas detection is increased by tens of times, which can detect latent equipment faults earlier. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] in: Figure 1 This is an isometric schematic diagram of a sulfur hexafluoride sampling and enrichment device in one embodiment.

[0019] Figure label: 1. Intake pipe; 2. Intake valve; 3. Piping; 31. Inlet; 32. First branch pipe; 33. Second branch pipe; 34. Outlet; 35. Third branch pipe; 4. First valve; 5. Mixing cylinder; 6. Semiconductor cryogenic cold trap; 7. First outlet pipe; 8. First outlet valve; 9. Second valve; 91. Gas collecting cylinder; 92. Second outlet pipe; 93. Second outlet valve; 94. Vacuum pump; 95. Pressure gauge; 96. Gas washing bottle; 97. Third valve; 98. Third outlet pipe; 99. Third outlet valve; 100. Housing; 200. Compartment space; 300. Leakage alarm. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0022] In the description of this invention, it should be noted that if terms such as "upper," "lower," "inner," or "outer" are used to indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of this invention is usually placed, they are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0023] Furthermore, the terms "first" and "second" are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.

[0024] It should be noted that, where there is no conflict, the features in the embodiments of the present invention can be combined with each other.

[0025] Please combine them together Figure 1 The sulfur hexafluoride mixed sampling and enrichment device provided by the present invention will now be described.

[0026] The sulfur hexafluoride mixed sampling and enrichment device includes: an inlet pipe 1, an inlet valve 2, a pipeline 3, a first valve 4, a mixed gas bottle 5, a semiconductor cryogenic cold trap 6, a first outlet pipe 7, a first outlet valve 8, multiple second valves 9, and multiple gas collection bottles 91.

[0027] The pipeline 3 includes an inlet end 31, a first branch pipe 32, and multiple second branch pipes 33. The inlet pipe 1 is connected to the inlet end 31. The inlet pipe 1 is equipped with an inlet valve 2, which is used to open or close the inlet pipe 1. The gas mixing bottle 5 is connected to the first branch pipe 32. The first valve 4 is installed on the first branch pipe 32, which is used to open or close the gas mixing bottle 5. Each second branch pipe 33 is sequentially arranged between the inlet end 31 and the first branch pipe 32, and is connected to each gas collecting bottle 91. Each second valve 9 is installed on each second branch pipe 33, which is used to open or close the gas collecting bottle 91. The semiconductor cryogenic cold trap 6 is fixed to the gas mixing bottle 5 and is used to cool the gas mixing bottle 5. The first outlet pipe 7 is connected to the gas mixing bottle 5 through the first outlet valve 8.

[0028] It is understood that the inlet pipe 1 of the sulfur hexafluoride mixed sampling enrichment device is connected to the inlet end 31. The inlet pipe 1 is equipped with an inlet valve 2, which is used to open or close the inlet pipe 1. The mixed gas bottle 5 is connected to the first branch pipe 32. The first valve 4 is installed on the first branch pipe 32, which is used to open or close the mixed gas bottle 5. Each second branch pipe 33 is sequentially arranged between the inlet end 31 and the first branch pipe 32, and is connected to each gas collection bottle 91. Each second valve 9 is installed on each second branch pipe 33, which is used to open or close the gas collection bottle 91. The semiconductor cryogenic cold trap 6 is fixed to the mixed gas bottle 5 and is used to cool the mixed gas bottle 5. The first outlet pipe 7 is connected to the mixed gas bottle 5 through the first outlet valve 8. By setting multiple gas collection bottles 91, multiple sulfur hexafluoride filling devices can be sampled. Then, the gases in the multiple sampled gas collection bottles 91 are mixed into the mixed gas bottle 5. In the laboratory, only the mixed sample needs to be tested, which greatly shortens the testing time and saves troubleshooting time. After most of the background sulfur hexafluoride gas is removed by cryogenic liquefaction in the semiconductor cryogenic cold trap 6, the concentration of fault gases (sulfur dioxide, hydrogen sulfide, etc.) is concentrated. During laboratory testing, the sensitivity of fault gas detection is increased by tens of times, which can detect latent equipment faults earlier.

[0029] It should be noted that when testing multiple sulfur hexafluoride (SF6) filling devices, connect the inlet pipe 1 to the current SF6 filling device, open the inlet valve 2, and SF6 gas enters the pipeline 3 through the inlet pipe 1. Then open the second valve 9, and the SF6 in the pipeline 3 enters the gas collecting bottle 91 through the second branch pipe 33. Then close the second valve 9. Next, connect the inlet pipe 1 to the next SF6 filling device, and the SF6 gas enters the pipeline 3 through the inlet pipe 1. Then open the second valve 9 again, and the SF6 in the pipeline 3... The sulfur hexafluoride enters the next gas collecting bottle 91 through the second branch pipe 33, and then the second valve 9 is closed. This process is repeated for all gas collecting bottles 91. After sampling the gas from different sulfur hexafluoride filling devices, the inlet valve 2 is closed, the first valve 4 and all the second valves 9 are opened, so that the gas from all gas collecting bottles 91 enters the mixing bottle 5. Then the first valve 4 and all the second valves 9 are closed. The semiconductor cryogenic cold trap 6 cools the mixing bottle 5 to -70°C, lowering the temperature of the cold trap to slightly below the melting point of SF6. At this point, most of the SF6 becomes solid. The first outlet valve 8 is opened, and the enriched SF6 decomposition products are extracted from the first outlet pipe 7.

[0030] It should be added that opening the first valve 4 and then opening all the second valves 9 in sequence allows a portion of the gas from all the gas collecting bottles 91 to enter the mixing bottle 5, so that the mixing bottle 5 can obtain the gas from each gas collecting bottle 91.

[0031] Of course, in other embodiments, the intake valve 2, the first valve 4, the first exhaust valve 8 and the multiple second valves 9 are normally closed for manual intake, and are closed in normal state, and will be opened when the button is pressed.

[0032] In this embodiment, the sulfur hexafluoride mixing sampling and enrichment device further includes multiple second vent pipes 92 and multiple second vent valves 93. Each second vent pipe 92 is connected to each gas collection bottle 91, and each second vent valve 93 is installed on each second vent pipe 92 and is used to open or close the second vent pipe 92. If sulfur hexafluoride decomposition products are detected in the mixing bottle 5, the second vent valves 93 are opened sequentially to test each gas collection bottle 91 in turn, thereby determining which gas collection bottle 91 has a problem and thus determining which sulfur hexafluoride filling device has a problem.

[0033] Furthermore, the sulfur hexafluoride mixed sampling and enrichment device also includes a vacuum pump 94, which is located between the inlet end 31 and the second branch pipe 33. The vacuum pump 94 is connected to the pipeline 3 and is used for evacuation. By setting up the vacuum pump 94, air and residual sulfur hexafluoride decomposition products in the pipeline 3, the gas collecting bottle 91, and the mixed gas bottle 5 can be removed.

[0034] Furthermore, the sulfur hexafluoride (SF6) mixing sampling and enrichment device also includes a pressure gauge 95, which is installed in pipeline 3 and located between the inlet 31 and the vacuum pump 94. The pressure gauge 95 is used to detect the pressure of the gas collection bottle 91 and the vacuum degree evacuated by the vacuum pump 94. SF6 slowly enters the gas collection bottle 91 from the SF6 filling device. When the pressure reading on the pressure gauge 95 matches the pressure of the SF6 filling device, it indicates that the bottle is full. In addition, after the vacuum pump 94 evacuates to a certain pressure value, observing the pressure value displayed on the pressure gauge 95 indicates that a certain vacuum degree has been reached, signifying that the evacuation process is complete.

[0035] Furthermore, the sulfur hexafluoride (SF6) mixed sampling and enrichment device also includes a gas washing bottle 96 and a third valve 97. Pipeline 3 further includes an outlet 34 and a third branch pipe 35. The third branch pipe 35 connects to the outlet 34 and the gas washing bottle 96. The third valve 97 is installed on the third branch pipe 35 and is used to open or close the gas washing bottle 96. When gas flushing of pipeline 3 is required, the third valve 97 is opened, and gas flows through pipeline 3 and the third branch pipe 35 into the gas washing bottle 96, thereby flushing pipeline 3. In addition, the gas washing bottle 96 can also recover gas from the gas collecting bottle 91 and the mixing bottle 5, reducing SF6 emissions.

[0036] Furthermore, the sulfur hexafluoride mixed sampling and enrichment device also includes a third outlet pipe 98 and a third outlet valve 99. The third outlet pipe 98 is connected to the gas washing bottle 96, and the third outlet valve 99 is installed on the third outlet pipe 98 and is used to open or close the third outlet pipe 98. Opening the third outlet valve 99 allows the gas in the gas washing bottle 96 to flow out through the third outlet pipe 98.

[0037] Furthermore, the sulfur hexafluoride mixed sampling and enrichment device also includes a housing 100, which has a accommodating space 200. An inlet pipe 1, an inlet valve 2, a pipeline 3, a first valve 4, a mixing bottle 5, a semiconductor cryogenic cold trap 6, a first outlet pipe 7, a first outlet valve 8, multiple second valves 9, and multiple gas collection bottles 91 are all installed within the accommodating space 200. The housing 100 provides a relatively sealed environment for the gas collection bottles 91, the mixing bottle 5, and the washing bottle 96, protecting them and preventing accidental leakage into the environment.

[0038] Furthermore, the sulfur hexafluoride mixed sampling and enrichment device also includes a leak alarm 300, which is installed within the containment space 200 and used to detect sulfur hexafluoride gas. This allows for the detection of any leaked sulfur hexafluoride gas.

[0039] Furthermore, the inner walls of each gas collecting cylinder 91 and the inner wall of the mixing cylinder 5 are coated with a passivation coating. This prevents the adsorption of substances such as SO2 or H2S.

[0040] In one embodiment, the sulfur hexafluoride (SF6) mixed sampling and enrichment device further includes a microprocessor control system (not shown in the figure), which is integrated inside the housing 100 and electrically connected to the valves, vacuum pump 94, pressure gauge 95, and semiconductor cryogenic cold trap 6. After the user sets the sampling parameters via the touch screen on the housing 100, the microprocessor automatically performs the following operations: First, it turns on the vacuum pump 94 and simultaneously presses the inlet valve 2, the first valve 4, the second valve 9, and the third valve 97 to evacuate the system until the pressure gauge 95 displays 10^-3 Pa, continuing for 5 minutes to remove air and residues; then, it turns off the vacuum pump 94, connects the inlet pipe 1 to the SF6 filling device, presses the third valve 97, and flushes the SF6 gas pipeline 3 for 30 seconds, returning the waste gas to the washing gas bottle 96; next, it presses each of the second valves 9 in sequence, and each gas collecting bottle 91 samples until the pressure gauge 95 displays the same pressure as the device (error ±0.1). After sampling, the valve automatically closes. Once all samples are collected, the microprocessor first presses valve 4, then simultaneously presses all second valves 9, mixing the gas for 10 minutes. Finally, the semiconductor cryogenic trap 6 is activated, with the temperature precisely controlled at -62℃ (using a PID algorithm, fluctuation ±0.5℃). After 15 minutes of enrichment, the first outlet valve 8 is opened, and the enriched gas is introduced into a gas chromatograph-mass spectrometer (GC-MS) for detection through the first outlet pipe 7. If the concentration of decomposition products in the mixed sample exceeds 1 ppm, the system automatically opens the second outlet valve 93 sequentially to detect each gas collecting bottle 91. Furthermore, the inner walls of gas collecting bottles 91 and mixing bottles 5 are coated with a 0.1 mm thick PTFE passivation coating, which, according to tests, has an SO2 adsorption rate of less than 5%. The leak alarm 300 uses an electrochemical sensor with an SF6 detection sensitivity of 1 ppm, automatically triggering an alarm when the sensitivity exceeds the limit. This device can also be used for the detection of decomposition products of other insulating gases (such as N2), achieved by adjusting the temperature of the semiconductor cryogenic trap 6 to -150℃.

[0041] This invention also discloses a sulfur hexafluoride mixed sampling enrichment method, which includes the sulfur hexafluoride mixed sampling enrichment device of any of the above embodiments, and the method includes the following steps: Before sampling, turn on the vacuum pump 94, press the inlet valve 2, the first valve 4, the second valve 9 and the third valve 97 to evacuate the gas collecting bottle 91, the gas mixing bottle 5 and the gas washing bottle 96 to remove the air and residual sulfur hexafluoride decomposition products in the pipeline 3, gas collecting bottle 91, gas mixing bottle 5 and gas washing bottle 96, and then turn off the vacuum pump 94. Connect the inlet pipe 1 to the sulfur hexafluoride filling equipment, press the third valve 97, and the sulfur hexafluoride gas enters the gas washing bottle 96 through the pipeline 3 and the third branch pipe 35 to flush the pipeline 3 and recover the waste gas. Press the second valve 9. Sulfur hexafluoride in the sulfur hexafluoride filling device slowly enters the gas collecting bottle 91. When the pressure reading on the pressure gauge 95 matches the pressure of the sulfur hexafluoride filling device, it indicates that the bottle is full. Repeat the above steps, pressing each second valve 9 in sequence to complete the gas sampling of each gas collecting bottle 91. After sampling is completed, first press the first valve 4, then press each of the second valves 9 at the same time. The gas in each gas collecting bottle 91 enters the mixing bottle 5, and the gas mixing is completed. Turn on the semiconductor cryogenic cold trap 6 switch, and the temperature drops to -60 to -64°C. At this time, most of the SF6 becomes solid. Open the first vent valve 8 and extract the enriched SF6 decomposition products through the first vent pipe 7. During testing, the sample in the gas mixing bottle 5 is tested first. If it contains sulfur hexafluoride decomposition products, the gas sample in the gas collecting bottle 91 is tested in turn.

[0042] It is understood that by using the method of the present invention, multiple gas collecting bottles 91 can be used to sample multiple sulfur hexafluoride (SF6) filling devices. The gases from the multiple sampled gas collecting bottles 91 are then mixed into a mixing bottle 5. After most of the SF6 is removed by cryogenic liquefaction in a semiconductor cryogenic cold trap 6, the faulty gas enters the detection equipment for testing. Only the mixed sample needs to be tested, greatly shortening the detection time and saving troubleshooting time. If SF6 decomposition products are detected in the mixing bottle 5, the second outlet valve 93 is opened sequentially, and each gas collecting bottle 91 is tested sequentially to determine which gas collecting bottle 91 is faulty, and thus which SF6 filling device is malfunctioning.

[0043] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0044] The above description discloses only preferred embodiments of the present invention and should not be construed as limiting the scope of the present invention. Therefore, equivalent variations made in accordance with the claims of the present invention are still within the scope of the present invention.

Claims

1. A sulfur hexafluoride mixed sampling and enrichment device, characterized in that, The sulfur hexafluoride mixed sampling and enrichment device includes: an inlet pipe, an inlet valve, a pipeline, a first valve, a mixed gas bottle, a semiconductor cryogenic cold trap, a first outlet pipe, a first outlet valve, multiple second valves, and multiple gas collection bottles; The pipeline includes an inlet end, a first branch pipe, and multiple second branch pipes. The inlet pipe is connected to the inlet end and is equipped with an inlet valve for opening or closing the inlet pipe. The gas mixing bottle is connected to the first branch pipe, and the first valve is installed on the first branch pipe for opening or closing the gas mixing bottle. Each second branch pipe is sequentially arranged between the inlet end and the first branch pipe and is connected to each gas collecting bottle. Each second valve is installed on each second branch pipe for opening or closing the gas collecting bottle. The semiconductor cryogenic cold trap is fixed to the gas mixing bottle and is used to cool the gas mixing bottle. The first outlet pipe is connected to the gas mixing bottle through the first outlet valve.

2. The sulfur hexafluoride mixed sampling and enrichment device according to claim 1, characterized in that, The sulfur hexafluoride mixed sampling and enrichment device further includes multiple second gas outlet pipes and multiple second gas outlet valves. Each second gas outlet pipe is connected to each of the gas collection bottles, and each second gas outlet valve is installed on each second gas outlet pipe and is used to open or close the second gas outlet pipe.

3. The sulfur hexafluoride mixed sampling and enrichment device according to claim 1, characterized in that, The sulfur hexafluoride mixed sampling and enrichment device also includes a vacuum pump, which is located between the inlet end and the second branch pipe. The vacuum pump is connected to the pipeline and is used for evacuation.

4. The sulfur hexafluoride mixed sampling and enrichment device according to claim 3, characterized in that, The sulfur hexafluoride mixed sampling and enrichment device also includes a pressure gauge, which is installed in the pipeline and located between the gas inlet and the vacuum pump. The pressure gauge is used to detect the pressure of the gas collection bottle and the vacuum degree of the vacuum pump.

5. The sulfur hexafluoride mixed sampling and enrichment device according to claim 1, characterized in that, The sulfur hexafluoride mixed sampling and enrichment device also includes a gas washing bottle and a third valve. The pipeline also includes an outlet end and a third branch pipe. The third branch pipe is connected to the outlet end and the gas washing bottle. The third valve is installed on the third branch pipe and is used to open or close the gas washing bottle.

6. The sulfur hexafluoride mixed sampling and enrichment device according to claim 5, characterized in that, The sulfur hexafluoride mixed sampling enrichment device further includes a third gas outlet pipe and a third gas outlet valve. The third gas outlet pipe is connected to the gas washing bottle, and the third gas outlet valve is installed on the third gas outlet pipe and is used to open or close the third gas outlet pipe.

7. The sulfur hexafluoride mixed sampling and enrichment device according to any one of claims 1-6, characterized in that, The sulfur hexafluoride mixed sampling and enrichment device also includes a housing with a accommodating space. The inlet pipe, the inlet valve, the pipeline, the first valve, the mixed gas bottle, the semiconductor cryogenic cold trap, the first outlet pipe, the first outlet valve, a plurality of second valves and a plurality of gas collection bottles are all installed in the accommodating space.

8. The sulfur hexafluoride mixed sampling and enrichment device according to claim 7, characterized in that, The sulfur hexafluoride mixed sampling and enrichment device also includes a leakage alarm, which is installed in the containment space and used to detect sulfur hexafluoride gas.

9. The sulfur hexafluoride mixed sampling and enrichment device according to claim 1, characterized in that, The inner walls of each gas collecting bottle are coated with a passivation coating, and the inner walls of the gas mixing bottle are coated with a passivation coating.

10. A method for mixed sampling and enrichment of sulfur hexafluoride, the method comprising the sulfur hexafluoride mixed sampling and enrichment apparatus as described in any one of claims 1-9, characterized in that, The method includes the following steps: Before sampling, turn on the vacuum pump, press the inlet valve, the first valve, the second valve and the third valve to evacuate the gas collecting bottle, the gas mixing bottle and the gas washing bottle to remove air and residual sulfur hexafluoride decomposition products from the pipeline and the gas collecting bottle, the gas mixing bottle and the gas washing bottle, and then turn off the vacuum pump; Connect the inlet pipe to the sulfur hexafluoride filling device, press the third valve, and the sulfur hexafluoride gas enters the gas washing bottle through the pipeline and the third branch pipe to flush the pipeline and recover the waste gas; Press the second valve, and sulfur hexafluoride in the sulfur hexafluoride filling device slowly enters the gas collecting bottle. When the pressure value of the pressure gauge is consistent with the pressure of the sulfur hexafluoride filling device, it means that it is full. Repeat the above steps, press each of the second valves in sequence, and complete the gas sampling of each gas collecting bottle. After sampling is completed, press the first valve first, and then press each of the second valves simultaneously. The gas in each gas collecting bottle enters the gas mixing bottle, and the gas mixing is completed. Turn on the semiconductor cryogenic cold trap switch, and the temperature drops to -60 to -64°C. At this time, most of the SF6 becomes solid. Open the first vent valve and extract the enriched SF6 decomposition products through the first vent pipe. During testing, the sample in the gas mixing bottle is tested first. If it contains sulfur hexafluoride decomposition products, the gas sample in the gas collecting bottle is tested sequentially.

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