JP3720675B2 - Gas recovery method and gas recovery device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a gas recovery method and a gas recovery apparatus that, for example, sucks a gas to be recovered from an apparatus filled with the gas to be charged and recovers the gas in a high-pressure gas cylinder.
[0002]
[Prior art]
As an apparatus filled with the gas to be recovered, for example, a high voltage apparatus such as a substation equipment is filled with sulfur hexafluoride gas (SF6) excellent in insulation inside at a high pressure and disposed inside. High voltage machines are prevented from short-circuiting.
[0003]
This sulfur hexafluoride gas is not a gas that adversely affects the human body, but as a result of recent research, it has been found that it is a gas that affects global warming. Therefore, we are trying to collect and recycle sulfur hexafluoride gas from environmental measures to prevent global warming. That is, when maintaining the high voltage device, the gas recovery device sucks the sulfur hexafluoride gas in the high voltage device and collects it in the high pressure gas cylinder. It is filled with sulfur gas.
[0004]
As shown in FIG. 4, the gas recovery apparatus (A) includes a gas recovery apparatus main body 52, a hose 54 that connects the high voltage apparatus 51 to the gas recovery apparatus main body 52, and a high-pressure gas cylinder 53 connected to the gas recovery apparatus main body 52. A hose 55 is provided.
[0005]
One end of the hose 54 is connected to the suction port 56 of the gas recovery device main body 52, and the other end is connected to the hose attachment port 51 a of the high voltage device 51. The hose 55 has one end connected to the discharge port 57 of the gas recovery apparatus main body 52 and the other end connected to the hose attachment port 53 a of the high-pressure gas cylinder 53.
[0006]
A gas recovery passage 58 extending from the suction port 56 to the discharge port 57 is formed inside the gas recovery device main body 52.
[0007]
The gas recovery passage 58 includes a check vacuum pump 61, a suction vacuum pump 62, a gas reservoir 63, a compressor 64, a cooler 65, and a pressure reducing adjustment valve 66 in order from the suction port 56 side.
[0008]
The check vacuum pump 61 is a vacuum pump for checking the gas tightness of the gas recovery device (A) before starting recovery of sulfur hexafluoride gas.
[0009]
The suction vacuum pump 62 is a vacuum pump for sucking sulfur hexafluoride gas from the high voltage device 51 into the gas recovery passage 58. The gas reservoir 63 is a part for temporarily holding the sucked sulfur hexafluoride gas and introducing it into the compressor 64 in a stable state. The compressor 64 compresses the sucked sulfur hexafluoride gas into a high-pressure gas. The cooler 65 cools and liquefies sulfur hexafluoride gas. In addition, since the liquefied sulfur hexafluoride gas flows through the hose 55 connecting the high-pressure gas cylinder 53 and the gas recovery apparatus main body 52, a pressure-resistant and heat-insulating hose having pressure resistance and heat insulation is adopted.
[0010]
The pressure reducing adjustment valve 66 is a valve provided in a bypass passage 69 that connects the discharge port 57 side to the suction port 56 side from the suction vacuum pump 62 by the cooler 65 of the gas recovery passage 58. The high-pressure gas accumulated in the gas recovery passage 58 on the high-pressure gas cylinder 53 side is introduced into the gas recovery passage 58 on the suction port 56 side from the suction vacuum pump 62, and the gas recovery passage 58 on the high-pressure gas cylinder 53 side is introduced from the cooler 65. Used when depressurizing, usually in a closed state.
[0011]
Hereinafter, the gas recovery procedure in the gas recovery apparatus (A) will be described in order.
[0012]
I. It is confirmed that the gas tightness of the gas recovery device (A) is secured. Specifically, the hose 54 and the hose 55 are connected to the high voltage device 51 and the high pressure gas cylinder 53 with the valve of the hose attachment port 51 a of the high voltage device 51 and the hose attachment port 53 a of the high pressure gas cylinder 53 closed. Attach and check vacuum pump 61 to activate hose 54, gas recovery passage 58 and hose 55 inside gas recovery device main body 52, and confirm that there are no leak points in hose 54, gas recovery passage 58 and hose 55. To do.
[0013]
This is to prevent sulfur hexafluoride gas from leaking into the atmosphere during gas recovery and mixing the atmosphere into the gas recovery passage 58. In addition, the airtightness of the device is confirmed by making a vacuum, and at the same time as confirming the airtightness, before starting the gas recovery, the air in the gas recovery passage 58 is discharged to recover the sulfur hexafluoride gas. This is to prevent impurities from being mixed in the high-pressure gas cylinder 53.
[0014]
II. Next, the valve of the hose attachment port 67 of the vacuum pump 61 for check is closed, and the valves of the hose attachment port 51a of the high voltage device 51 and the hose attachment port 53a of the high pressure gas cylinder 53 are opened. Sulfur fluoride gas is introduced into the gas recovery passage 58, stored in the gas reservoir 63 of the gas recovery passage 58, compressed by the compressor 64, further liquefied by the cooler 65, and recovered by the high pressure gas cylinder 53 through the hose 55. To do. When the atmospheric pressure of the sulfur hexafluoride gas in the high voltage device 51 decreases, the suction vacuum pump 62 is operated to recover the sulfur hexafluoride gas until the inside of the high voltage device 51 becomes vacuum.
[0015]
III. With the high-voltage device 51 in a vacuum state, the valve of the hose attachment port 51a of the high-voltage device 51 and the valve of the hose attachment port 53a of the high-voltage gas cylinder 53 are closed, and the recovery of sulfur hexafluoride gas is completed. The sulfur hexafluoride gas in the high voltage gas cylinder 53 is supplied again into the high voltage device 51 and reused after maintenance.
[0016]
[Problems to be solved by the invention]
It is desirable that all the sulfur hexafluoride gas is recovered in the high pressure gas cylinder 53. However, according to the above procedure, most of the sulfur hexafluoride gas is recovered in the high-pressure gas cylinder 53, but as shown in black in FIG. 4, the hose 55 and the gas recovery passage 58 are connected to the high-pressure gas cylinder 53. There remains residual sulfur hexafluoride gas that cannot be recovered, and this residual gas is released into the atmosphere after the recovery operation is completed.
[0017]
In particular, since the sulfur hexafluoride gas remaining in the hose 55 from the cooler 65 of the gas recovery passage 58 is liquefied, the amount is considered to be considerably large when converted to a state where it is vaporized to atmospheric pressure at room temperature.
[0018]
Therefore, an object of the present invention is to reuse the residual gas remaining in the gas recovery device and improve the gas recovery rate of the gas recovery device.
[0019]
[Means for Solving the Problems]
The gas recovery method according to the present invention includes a suction port connected to an apparatus filled with a gas to be recovered, a discharge port connected to a high-pressure gas cylinder that recovers the gas to be recovered, and a suction port and the discharge port. Using a gas recovery device that includes a gas recovery passage including a vacuum pump and a compressor, and a plurality of reserve tanks connected to the gas recovery passage through valves, the vacuum recovery pump and the inside of the reserve tank are evacuated. Connected to the device filled with the gas to be collected with the valve of the reserve tank closed, and then collected the gas to be collected from the device filled with the gas to be collected by the vacuum pump and compressor into the high pressure gas cylinder After the gas recovery operation, the reserve tank valves are sequentially opened and closed to sequentially recover the gas to be recovered remaining in the gas recovery passage to the reserve tank. The features.
[0020]
The gas recovery device according to the present invention communicates with a suction port connected to a device filled with a gas to be recovered, a discharge port connected to a high-pressure gas cylinder for recovering the gas to be recovered, a suction port and a discharge port, A gas recovery apparatus including a vacuum pump and a gas recovery passage equipped with a compressor includes a plurality of reserve tanks each connected to the gas recovery passage through a valve, and the vacuum recovery pump and the inside of the reserve tank are evacuated. Connected to the device filled with the gas to be collected with the valve of the reserve tank closed, and then collected the gas to be collected from the device filled with the gas to be collected by the vacuum pump and compressor into the high pressure gas cylinder After the gas recovery operation, the gas to be recovered remaining in the gas recovery passage is reserved by opening and closing the valves of the reserve tank in order. Wherein the sequentially recovered link.
[0021]
The volume of the reserve tank is preferably larger than the volume of the gas recovery passage.
[0022]
In addition, a first barometer provided in the gas recovery passage, a second barometer provided in the reserve tank, and a control device that opens and closes the valve of the reserve tank are provided. When recovering residual gas, when the measured values of the first barometer and second barometer become the same value, the valve of the reserve tank storing the residual gas is closed, and then the residual gas is The reserve tank valve is sequentially opened and closed so that the reserve tank valve to be stored is opened .
[0023]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment in which a gas recovery method and a gas recovery device according to the present invention are applied to recovery of sulfur hexafluoride gas will be described with reference to FIGS. 1 and 2. In FIGS. 1 and 2, the same members as those in the gas recovery apparatus (A) shown in FIG.
[0024]
As shown in FIG. 1, this gas recovery device (B) has four reserve tanks (11, 12, 13, 14) attached to a gas recovery passage 58. The reserve tanks (11, 12, 13, 14) are attached to the suction port 56 side of the suction vacuum pump 62 in the gas recovery passage 58. In FIGS. 1 and 2, 21 is a barometer for measuring the pressure in the gas recovery passage 58, and 22 is the pressure in the hose 23 for connecting the reserve tank (11, 12, 13, 14) to the gas recovery passage 58. It is a barometer. The reserve tanks (11, 12, 13, 14) each have a volume of 24 l, and the total volume of the hose 55 and the gas recovery passage 58 is approximately 20 l.
[0025]
A method of using this gas recovery device (B) will be described.
[0026]
First, the gas recovery device (B) is configured such that the hoses 54 and 55 are connected to the high voltage device 51 and the high pressure gas cylinder with the valves of the hose attachment port 51a of the high voltage device 51 and the hose attachment port 53a of the high pressure gas cylinder 53 closed. 53 and the check vacuum pump 61 is operated with the valves of the gas intake ports (15, 16, 17, 18) of the reserve tanks (11, 12, 13, 14) opened. As a result, the airtightness of the hose 54, the gas recovery passage 58 and the hose 55 is ensured, and the hose 54, the hose 55, the gas recovery passage 58 and the reserve tanks (11, 12, 13, 14) are evacuated to supply gas. Impurities are prevented from being mixed in the high-pressure gas cylinder 53 when recovered.
[0027]
Next, the valve of the gas intake port (15, 16, 17, 18) of the reserve tank (11, 12, 13, 14) and the valve of the hose attachment port 67 of the check vacuum pump 61 are closed, and the high voltage device 51 is closed. The valve of the hose attachment port 51a and the valve of the hose attachment port 53a of the high pressure gas cylinder 53 are opened, and the sulfur hexafluoride gas in the high voltage device 51 is introduced from the hose 54 into the gas recovery passage 58 and compressed by the compressor 64. Further, it is liquefied by the cooler 65 and collected in the high-pressure gas cylinder 53 through the hose 55. When the atmospheric pressure of the sulfur hexafluoride gas in the high voltage device 51 decreases, the suction vacuum pump 62 is operated to recover the sulfur hexafluoride gas until the inside of the high voltage device 51 becomes vacuum.
[0028]
With the high-voltage device 51 in a vacuum state, the valve of the hose attachment port 51a of the high-voltage device 51 and the valve of the hose attachment port 53a of the high-pressure gas cylinder 53 are closed to finish the gas recovery. Since the hose 54 is in a vacuum similar to the high voltage device 51, as shown in FIG. 2, when the gas recovery is finished, the valve of the suction port 56 of the gas recovery device main body 52 is closed, and the hose 54 is closed. 54 should be removed.
[0029]
Next, the residual gas remaining in the hose 55 and the gas recovery passage 58 is provisionally stored in the reserve tank (11, 12, 13, 14) by the following procedure.
[0030]
First, in FIG. 2 showing the state when the residual gas is stored, the decompression regulating valve 66 is opened, and the high pressure gas accumulated in the gas recovery passage 58 and the hose 55 on the discharge port 57 side from the cooler 65 is evacuated. The gas is discharged from the suction vacuum pump 62 to the gas recovery passage 58 on the suction port 56 side, and the gas recovery passage 58 and the hose 55 on the discharge port 57 side are decompressed from the cooler 65. Thereby, the residual gas can be circulated in the gas recovery passage 58.
[0031]
Next, the valve of the gas intake port 15 of the first reserve tank 11 is opened. Since the reserve tank 11 is evacuated before the gas is collected, the residual gas is sucked until the pressure in the reserve tank 11 and the gas collection passage 58 becomes uniform by opening the valve of the gas intake port 15. Can do. It should be noted that the barometric pressure becomes uniform when the required time has elapsed, and it can be confirmed that the barometers 21 and 22 have the same value, thereby making it uniform.
[0032]
Thus, approximately 54.4% (24/44) of the residual gas is temporarily stored in the first reserve tank 11 according to the volume ratio of the reserve tank 11 and the (hose 55 + gas recovery passage 58). be able to. Further, at this stage, the gas remaining in the gas recovery passage 58 is about 45.6% (20/44) compared with that before the residual gas recovery.
[0033]
Next, the valve of the gas intake port 15 of the first reserve tank 11 is closed, and the valve of the gas intake port 16 of the second reserve tank 12 is opened. Since the second reserve tank 12 is vacuum like the first reserve tank 11, residual gas is maintained until the pressure in the reserve tank 12 and the gas recovery passage 58 becomes uniform by opening the valve of the gas intake port 16. Can be aspirated. As a result, 24.8% {(20/44) × (24/44)} of the residual gas in the total volume of the residual tank 12 by the volume ratio of the reserve tank 12 and (the hose 55 + the gas recovery passage 58) It can be temporarily stored in the tank 12.
[0034]
Thereafter, similarly, the valves of the gas intake ports 17 and 18 of the third reserve tank 13 and the fourth reserve tank 14 are sequentially opened and closed to suck the residual gas.
[0035]
Accordingly, 11.3% {(20/44) 2 × (24/44)} of the residual gas can be stored in the third reserve tank 13, and the fourth reserve tank can be stored. 14, the remaining gas of 5.1% {(20/44) 3 × (24/44)} among the total residual gas can be stored. As a result, the sulfur hexafluoride gas finally remaining in the gas recovery passage 58 is about 4.4% of the total residual gas.
[0036]
That is, according to this gas recovery device (B), as shown in FIG. 3, the gas intake ports (15, 16, 17, 18) of the first to fourth reserve tanks (11, 12, 13, 14). By opening and closing the valves in order, the residual gas that has not been recovered in the past and has been released into the atmosphere can be sucked into the respective reserve tanks (11, 12, 13, 14) step by step. It is possible to store about 96% of the total.
[0037]
Next, the reuse of sulfur hexafluoride gas stored in the reserve tanks (11, 12, 13, 14) will be described.
[0038]
Until the sulfur hexafluoride gas stored in the reserve tank (11, 12, 13, 14) is again extracted from the high voltage device 51, the reserve tank (11, 12, 13, 14) is used. ) Store in.
[0039]
When the sulfur hexafluoride gas is extracted again from the high voltage device 51, the valves of the gas intake ports (15, 16, 17, 18) of the reserve tanks (11, 12, 13, 14) are closed. As described above, the hose 54 and the hose 55 are connected to operate the check vacuum pump 61, and the hose 54, the gas recovery passage 58 and the hose 55 are evacuated.
[0040]
Then, by opening the valve of the gas intake port (15, 16, 17, 18) of the reserve tank (11, 12, 13, 14) and starting the collection of sulfur hexafluoride gas, the reserve tank (11, 12, 13, 14), the sulfur hexafluoride gas in the high-pressure gas cylinder 53 can be recovered, and the reserve tanks (11, 12, 13, 14) can be evacuated. When the gas recovery is completed, the valves of the gas intake ports (15, 16, 17, 18) of the reserve tanks (11, 12, 13, 14) are closed, and the reserve tanks (11, 12, 13, 14) are closed. ) To a vacuum.
[0041]
After the gas recovery, the valve remaining in the gas intake port (15, 16, 17, 18) of the reserve tank (11, 12, 13, 14) is opened and closed again in order, thereby remaining in the gas recovery passage 58. The gas can be sucked and stored in the reserve tanks (11, 12, 13, 14).
[0042]
Thereby, the sulfur hexafluoride gas sucked into the reserve tanks (11, 12, 13, 14) can be collected in the high-pressure gas tank 53 and supplied into the high-voltage device 51 after maintenance to be reused.
[0043]
The gas recovery apparatus according to the embodiment of the present invention has been described above, but the gas recovery apparatus of the present invention is not limited to the above embodiment.
[0044]
For example, the number of reserve tanks is not limited to four. If the number of reserve tanks is increased, the residual gas storage rate is further improved. Further, if the reserve tank has a sufficiently large volume with respect to the volume of the gas recovery passage, the number of reserve tanks may be one. Further, the volume of each reserve tank and the order in which the valves of the intake ports of the reserve tank when the residual gas is stored can be arbitrarily changed.
[0045]
In the above-described residual gas recovery, the barometer 21 that measures the pressure in the gas recovery passage 58 and the barometer 22 that measures the pressure in the reserve tank (11, 12, 13, 14) have the same value. Provided with a control device configured to automatically open and close the valves of the gas intake ports (15, 16, 17, 18) of the reserve tank (11, 12, 13, 14) in the order described above. The recovery of residual gas may be automated.
[0046]
【The invention's effect】
In the gas recovery apparatus according to the present invention, the hose and the reserve tank for temporarily storing the residual gas in the gas recovery passage are disposed in the gas recovery passage closer to the suction port than the vacuum pump. The remaining gas can be sucked into the reserve tank and reused, and the gas recovery rate can be greatly improved.
[0047]
A plurality of the reserve tanks are provided, and when storing the residual gas, the reserve tanks are opened and closed in order and stored, so that the residual gas can be sucked into each reserve tank in stages and the residual gas storage rate is increased. improves.
[0048]
Since the volume of the reserve tank is larger than the volume of the gas recovery passage, the residual gas can be efficiently sucked into the reserve tank.
[0049]
In addition, a first barometer provided in the gas recovery passage, a second barometer provided in the reserve tank, and a control device that opens and closes the valve of the reserve tank are provided, and the control device remains in the gas recovery passage. When the measured values of the first barometer and the second barometer become the same during the residual gas recovery to recover the recovered gas, the valve of the reserve tank storing the residual gas is closed, and then the residual gas Since the reserve tank valve is sequentially opened and closed so as to open the reserve tank valve for storing the gas, the work of sucking the residual gas into the reserve tank can be automated.
[Brief description of the drawings]
FIG. 1 is a diagram schematically showing a gas recovery apparatus according to an embodiment of the present invention.
FIG. 2 is a view showing a state when the residual gas is sucked by the gas recovery apparatus according to the embodiment of the present invention.
FIG. 3 is a view showing a residual gas storage rate of the gas recovery apparatus according to the embodiment of the present invention.
FIG. 4 is a diagram showing an outline of a gas recovery device.
[Explanation of symbols]
11-14 Reserve tank 51 High voltage device
51a Hose attachment port 52 on the high voltage device side Gas recovery device 53 High pressure gas cylinder
53a Hose attachment port 54, 55 hose on the high pressure gas cylinder side
56 suction port
57 outlet
58 Gas recovery passage 61 Check vacuum pump 62 Suction vacuum pump 63 Gas reservoir 64 Compressor 65 Cooler 66 Depressurization regulating valve

Claims (4)

A suction port connected to an apparatus filled with the gas to be collected;
A discharge port connected to a high-pressure gas cylinder for collecting the gas to be collected;
A gas recovery passage that communicates the suction port and the discharge port and includes a vacuum pump and a compressor;
Using a gas recovery apparatus comprising a plurality of reserve tanks connected to the gas recovery passages via valves,
The gas recovery passageway and the reserve tank are evacuated by the vacuum pump, and then connected to the device filled with the gas to be recovered with the reserve tank valve closed, and the gas to be recovered is filled by the vacuum pump and the compressor. After the gas recovery operation for recovering the gas to be recovered from the installed device to the high pressure gas cylinder, the gas to be recovered remaining in the gas recovery passage is sequentially recovered in the reserve tank by sequentially opening and closing the valves of the reserve tank. Characterized gas recovery method. A suction port connected to an apparatus filled with the gas to be collected;
A discharge port connected to a high-pressure gas cylinder for collecting the gas to be collected;
In the gas recovery apparatus provided with a gas recovery passage provided with a vacuum pump and a compressor in communication with the suction port and the discharge port,
A plurality of reserve tanks connected to the gas recovery passages via valves,
The gas recovery passageway and the reserve tank are evacuated by the vacuum pump, and then connected to the device filled with the gas to be recovered with the reserve tank valve closed, and the gas to be recovered is filled by the vacuum pump and the compressor. The recovered gas remaining in the gas recovery passage is sequentially recovered in the reserve tank by sequentially opening and closing the valve of the reserve tank after the recovered gas recovery operation for recovering the recovered gas from the apparatus to the high-pressure gas cylinder. A gas recovery apparatus characterized by that. The gas recovery apparatus according to claim 2 , wherein a volume of the reserve tank is larger than a volume of the gas recovery passage. A first barometer provided in the gas recovery passage; a second barometer provided in the reserve tank; and a control device that opens and closes a valve of the reserve tank; and the control device is provided in the gas recovery passage. When the measurement value of the first barometer and the second barometer becomes the same value during the recovery of the residual gas to recover the residual gas to be recovered, the valve of the reserve tank storing the residual gas is closed, and the next The gas recovery apparatus according to claim 2 , wherein the valve of the reserve tank is sequentially opened and closed so that the valve of the reserve tank that stores residual gas is opened.

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