JP4064297B2 - Gas separation recovery filling equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
In the present invention, the power equipment is filled with SF6 gas (sulfur hexafluoride gas, the same applies hereinafter) or a mixed gas of SF6 gas and dilution gas as an insulating gas. The present invention relates to technology for extracting and collecting gas, or for refilling after inspection and repair.
[0002]
[Prior art]
SF6 gas is filled in transformers for high voltage power such as substations and circuit breakers in power circuits, making it possible to reduce the size of the equipment by taking advantage of its thermal stability, electrical stability, and high dielectric strength. The contribution of the substations in urban areas is greatly reduced. SF6 gas filled in transformers and circuit breakers includes those with a purity of 100% and those filled with dilution gas such as nitrogen gas.
[0003]
[Patent Document 1]
JP 2000-015039
Equipment that uses these devices must be regularly inspected and maintained and repaired. During inspection, maintenance and repair, these gases are extracted and replaced with the atmosphere. Inspect and repair. When the inspection and repair are completed, the insulating gas is filled again and operation begins. At the time of gas extraction, vacuum recovery is performed until SF6 gas does not remain in the equipment until a high vacuum is reached, and at the time of filling, air is exhausted to a high vacuum so that no air remains in the container of power equipment. It was necessary to fill the insulating gas with a predetermined concentration. This took a long time. Conventionally, when gas is extracted, there is little damage to human bodies and the like due to these gases, so that they may be released into the atmosphere.
[0004]
However, since SF6 gas is an expensive gas, there has been a recovery device that can be easily recovered and reused in terms of cost, and this SF6 gas must be recovered and refilled and reused after inspection and repair. There was also.
There was a device that pressurized and compressed the extracted SF6 gas, then cooled and liquefied and recovered, but it was recovered by sucking the recovered container up to a high vacuum range, or mixed with other dilution gas There was no device to separate and recover only SF6 gas from
[0005]
In other words, when the SF6 gas concentration is lowered by mixing with other diluent gas, the partial pressure is lowered, so it is compressed to a higher pressure, and cooling to a lower temperature is required, so the price of the apparatus is high. became.
[0006]
In recent years, the release of carbon dioxide or the like into the atmosphere has been regulated to prevent global warming. In 1997, the World Environment Conference was held in Kyoto. As a result, the release of SF6 gas, which has a global warming potential of 24,000 times that of carbon dioxide, into the atmosphere has become strictly regulated.
To prevent SF6 gas from leaking into the atmosphere,
(1) Eliminate gas that leaks from the sealing part of filling equipment.
(2) It is important to eliminate SF6 gas released into the atmosphere when it is involved in gas extraction and refilling during equipment installation, maintenance inspection, repair, dismantling and disposal.
[0007]
This (1) is very small at present due to the improved seal part of the equipment.
As for (2), the electric power industry created the “Standard for Handling SF6 Gas for Electric Power” in December 1998 by the Electric Joint Study Group, and decided to regulate its emission.
The main contents of the regulations are voluntary standards for suctioning and recovering to a high vacuum range of 0.015 MPa · abs (recovery rate of 97 vol% or more) at the time of inspection and repair, and 0.005 MPa · abs (recovery rate of 99 vol% or more) when dismantling and removal. It was created. The power industry has a public mission to minimize the power outage time associated with inspection and repair.
[0008]
There is a disadvantage that it takes a long time to recover if it is sucked and recovered to a high vacuum range. The low recovery rate at the time of inspection and repair is a compromise for shortening the power failure time due to the shutdown of the device as much as possible, and when removing it, it takes enough time to evacuate. In other words, the high vacuum region is sucked and collected, and the amount of leakage into the atmosphere is kept small.
[0009]
The electric power industry will develop and implement a collection device that meets the above criteria by 2005.
Even if 50vol% of inert gas, nitrogen gas, is mixed, the impulse breakdown voltage is 85% of the SF6 gas alone, and the breakdown power at the commercial power frequency is 96.6%. Increasing number of manufacturers are using it with nitrogen gas, which is a dilution gas, when it is sealed in containers.
[0010]
Conventionally, since the mixed gas mixed with such a diluent gas has been difficult to recover, most of it has been discharged into the atmosphere and discarded during inspection and disposal. In addition, SF6 gas is refilled after inspection / maintenance work and repair work is completed. It took a long time because it was refilled with a predetermined concentration of SF6 gas after it was sucked and the outside air was once discharged. An object of the present invention is to provide a gas separation / recovery / filling device that separates and collects the gas and refills the gas.
[0011]
[Problems to be solved by the invention]
This is to collect almost the entire amount of SF6 gas and dilution gas from the container to be collected (transformer, circuit breaker, etc.) without leaking into the atmosphere, and to shorten the time required for inspection work including recovery and refilling. For the purpose. During periodic inspections and repairs, after extracting the gas to be collected from the container to be collected, such as a transformer filled with insulating gas, the inside of the container is replaced with air, and then a person enters to repair and check the power equipment. After the repair is completed, the insulating gas is filled again. These times cause power outages because the operation of the power equipment is stopped. In order to shorten the power outage time, the time required for repair and inspection of the equipment and devices in the container to be collected is required for a predetermined time regardless of the performance of the gas recovery / refilling device. Therefore, it is necessary to extract and collect the gas other than the predetermined time and to shorten the refilling time of the gas, and the present invention intends to shorten the time by a new method related to the collecting and refilling.
[0012]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, the present invention separates and recovers, taking into consideration the characteristics of SF6 gas having a critical temperature of 45.64 ° C., a critical pressure of 3.66 MPa · G, a melting point of −50.8 ° C., and a sublimation point of −63.8 ° C.
FIG. 1 shows an embodiment of the present invention.
[0013]
The recovery container 26 is filled with a recovery target gas such as SF6 gas at a high pressure of about 0.6 MPa · abs. Since SF6 gas is an easily liquefied gas, a pressurizing unit 22 that pressurizes the SF6 gas with a pressurizing pump 31 and a liquefying unit 23 that cools and liquefies are provided, and in a range where the concentration of SF6 gas in the gas to be recovered is high Since the partial pressure of SF6 gas in the gas to be recovered is high, the pressure required for liquefying easily from the relationship between the liquefaction temperature of the gas to be liquefied and the pressure may be within a relatively low pressure range. Can be easily liquefied and recovered in a relatively high range.
[0014]
First, the SF6 gas is recovered to such a range that the pressure in the container to be recovered can be liquefied by the pressure pump 31 and the liquefying unit 23 by such a method. When this pressure becomes a predetermined pressure or less, a diluent gas such as nitrogen gas is introduced from the external gas supply unit 25 into the collection container and the SF6 gas is diluted, and the collection gas in which the dilution gas and the SF6 gas are mixed is supplied. It is intended to recover SF6 gas by introducing it into a gas separation section from a container to be recovered and separating it into dilution gas and SF6 gas.
[0015]
The gas to be collected filled in the container to be collected may be diluted with SF6 gas 100% and diluent gas such as nitrogen gas as described above. By providing a gas separation unit 21 that separates the SF6 gas from the mixed gas of the dilution gas and the SF6 gas, the inside of the container to be collected is filled with the dilution gas instead of evacuating to high vacuum and taking out the gas to be collected. The recovery time is faster in this method, where the positive pressure is taken out and the concentration of SF6 gas is increased and separated and recovered.
[0016]
This gas separation part is performed by the PSA method (Pressure Swing Adosorption) using an adsorbent that adsorbs a specific gas. When a mixed gas containing a specific gas and a dilution gas is fed into the adsorption cylinder filled with the adsorbent while applying pressure, the specific gas (one gas) is adsorbed and removed by this adsorbent, and the other gas that is not adsorbed is removed. Since it is separated and taken out from the multiple ends of the adsorption cylinder, this process is referred to as an adsorption process, and the pressure for feeding gas while applying pressure to the adsorption cylinder is referred to as operation pressure.
[0017]
If the mixed gas (raw material gas) is stopped feeding shortly before the specific gas is adsorbed by the adsorbent, and the pressure in the adsorbing cylinder is reduced from the inlet end of the adsorbing cylinder, the adsorbent adsorbs the adsorbent. The specific gas that has been removed is released from the adsorbent and discharged, and the adsorption capacity of the adsorbent is regenerated. This process is called a regeneration process.
[0018]
This process is called a pressure fluctuation adsorption (PSA) method because the gas is separated while repeating the adsorption process and the regeneration process, that is, applying pressure to the adsorption cylinder or reducing the pressure.
[0019]
The adsorbent adsorbs SF6 gas, which is the target gas, depending on its type, and does not adsorb nitrogen gas, etc., which is a dilution gas. Some gas adsorbs better.
The method of extracting the target gas is slightly different depending on the adsorbent used in this way.
For example, when SF6 gas is the target gas, the former adsorbent is molecular sieve charcoal with activated carbon having a molecular sieve function, and the latter adsorbent includes zeolite 5A type and 4A type. Zeolite also adsorbs part of the decomposition gas of nitrogen gas, moisture, carbon dioxide gas, oxygen and other SF6, so these can be separated from the mixed gas.
[0020]
In the former case, since the SF6 gas is separated by adsorbing to the adsorbent, the SF6 gas separated from the adsorbent is recovered in the decompression regeneration step.
In the latter case, SF6 gas is separated from the other end of the adsorption cylinder in the pressure adsorption process, and the SF6 gas is recovered in the adsorption process. An appropriate one of these adsorbents is selected to constitute a gas separation recovery and filling apparatus by the PSA method, and the present invention includes a method using both these adsorbents.
[0021]
Even when the gas separation unit having such a configuration separates SF6 gas into other dilution gas, a slight amount of SF6 gas is included on the dilution gas side. It is technically difficult to keep the SF6 gas contained in the separated diluted gas as low as ppm order over the entire range where the SF6 gas concentration in the gas to be recovered changes, and this SF6 gas has a certain concentration. It is a problem to release the exhaust gas contained in the atmosphere.
[0022]
For this reason, it is configured such that the dilution gas (including a small amount of SF6 gas) separated by the gas separation unit is returned to the container to be collected again.
That is, the container to be recovered and the gas separation part are connected by a conduit, and the gas to be recovered in which a plurality of types of gases in the container to be recovered are mixed is separated by the gas separation part, and one separated gas is recovered. At the same time, a gas separation / recovery / filling apparatus is constructed in which the other dilution gas is returned to the container to be collected by a conduit and filled. Then, the gas to be returned to the container to be recovered at the time of gas separation and recovery and refilling is changed as necessary. That is, in the above, when the gas to be recovered is a mixed gas in which SF6 gas and diluent gas are mixed, one gas separated by the gas separation unit is SF6 gas and the other gas is diluent gas at the time of recovery. At the time of filling, one of the separated gases is a dilution gas, and the other gas is SF6 gas. At the time of recovery, the mixed gas concentration gradually decreases by returning the diluted gas containing a small amount of SF6 to the container to be recovered.
[0023]
When gas is filled after the inspection work is completed, one of the gases separated by the gas separation unit is the dilution gas, and it is either collected outside the container to be collected or released to the atmosphere, and the other gas, SF6 gas, is put into the container to be collected. Put it back. As a result, the gas concentration in the container to be collected increases. The concentration in the container to be recovered can be controlled by returning the necessary separation gas based on the measured gas concentration.
Further details will be described later.
At the time of gas recovery, SF6 is filtered and leaked to the outside air by liquefying and recovering only the separated SF6 gas while circulating the gas cyclically by the route that returns the gas separated from the recovery container and gas separation part to the recovery container In addition, the SF6 gas concentration in the container to be recovered gradually decreases and the internal pressure of the container to be recovered also decreases. When this pressure falls below a predetermined value, the gas separation unit 21 continues gas separation while filling the dilution gas from the gas supply unit 100 having the dilution gas supply source and maintaining a constant pressure.
[0024]
When the concentration of the gas to be recovered becomes a certain value or less, the SF6 gas concentration contained in the dilution gas separated by the gas separation unit becomes very low and can be released to the atmosphere. The gas supply unit for supplying the dilution gas may be any gas that can be separated by the gas separation unit, and may be nitrogen gas or air (mixed gas of nitrogen and oxygen), which can be sufficiently separated by using zeolite as an adsorbent. . After the insulating gas is extracted, it is convenient because it is replaced with air and a person enters the inside to perform work (repair). The name of the container to be collected that contains this power equipment is good when recovering gas, but when it is filled again after inspection and repair, it becomes a filled container, but it is not good that the name changes with the same product. In this text, even when gas is filled, it is called a container to be collected.
[0025]
DETAILED DESCRIPTION OF THE INVENTION
After the repair and inspection, if SF6 gas lower than the target concentration is filled in the collection container after refilling the gas, the mixed gas in the collection container is introduced into the gas separation section and separated. The separated diluted gas is recovered by returning the SF6 gas to the container to be recovered, and the SF6 gas contained therein is reduced by further processing to be released into the atmosphere or contained in the exhaust gas. If the SF6 gas concentration is below a certain level, it is released into the atmosphere as it is, so that excess dilution gas is extracted from the container to be recovered, the SF6 gas concentration is increased, and the mixed gas concentration in the container to be recovered is the target value. To match.
[0026]
By using this means, it is not necessary to evacuate the air in the container to a high vacuum at the time of refilling, and after exhausting the air to a certain value, the dilution gas is injected first, and then the SF6 gas and the dilution gas are filled. The mixed gas is circulated through the route between the gas separation unit and the container to be recovered, and is separated into a dilution gas containing SF6 gas and air, etc. Since the SF6 gas mixture can be filled while being discharged, the filling time can be shortened.
More specifically, in the case of recovering the gas to be recovered, in the gas separation recovery filling device having the SF6 gas concentration sensor 20 and the gas separation unit 21, the gas to be recovered containing SF6 gas and other dilution gas from the recovery container 26 The SF6 gas is separated into SF6 gas and another dilution gas, and the SF6 gas is taken out from the SF6 gas outlet 3 to the pressurization unit 22 and the liquefaction unit 23, and liquefied and recovered. The pump 7 is configured to return to the recovery container 26, and the SF6 gas concentration in the recovery gas is detected by the SF6 gas concentration sensor 20. Open to release to the atmosphere.
[0027]
Further, in the gas separation recovery filling device having the gas separation unit 21, the pump 7, and the gas supply unit 25, the gas to be recovered including SF6 gas and other dilution gas is introduced into the gas separation unit 21 from the recovery container 26, The SF6 gas is recovered in the same manner as described above by separating it into SF6 gas and another dilution gas, and this dilution gas is returned to the recovery container 26 by the pump 7 and introduced into the gas separation unit 21 as described above. When the pressure of the gas in the container is lower than a predetermined pressure while being detected by the pressure sensor 36, the valve 29 is opened from the gas supply unit 25 to introduce and fill the container with the gas. Configure.
[0028]
【Example】
For example, if the operating pressure of the gas separation unit 21 is 0.2 MPa · G, the pressure at which gas is introduced from the gas supply unit 25 into the recovery container 26 and filling is started is also a pressure of 0.2 MPa · G or more. The standard. In this case, the PSA gas separation is performed by supplying the PSA system gas separation unit 21 with the pressure in the container to be collected.
The gas supplied from the gas supply unit 25 may be a dilution gas that can be separated by the gas separation unit 21. For example, nitrogen gas is supplied by the configuration of the nitrogen gas cylinder 27 and the pressure reducing valve 28, or the outside air by the air pump 42 is used. The apparatus can be configured to supply air with a device that introduces the air or a device that combines the air pump and the dryer 43.
[0029]
Another embodiment is shown in FIG. In this embodiment, the concentrated SF6 gas is taken out from the container to be collected and a gas takeout part 66 is supplied to the gas separation part. Since the portion to be liquefied and recovered after the SF6 gas outlet 3 separated from the gas separation unit 21 is the same, the description is omitted. In this method, the gas to be recovered is supplied to the gas separation unit through the gas extraction unit. This is because the gas extraction part is composed of a pressure reducing valve 69, a pressure increasing pump 65, a solenoid valve, etc., and the pressure of the gas to be recovered filled in the recovery container 26 is higher than the operating pressure of the PSA type gas separation part. When the pressure is high, the pressure is adjusted to be supplied to the operation pressure via the pressure reducing valve 69, and when the recovery operation proceeds and the pressure in the collection container 26 is lower than the operation pressure, the pressure is increased. The pump 65 is operated to extract the gas to be collected from the container 26 to be collected and to supply the pressure adjusted to the operation pressure necessary for the operation of the PSA.
[0030]
In the case of the configuration having this gas extraction part, in the gas separation recovery and filling apparatus having the gas extraction part 66 and the gas separation part 21 and the pump 7, the gas separation part is separated into SF6 gas and other dilution gas Thus, the gas mixed partially with SF6 gas in the dilution gas is returned to the recovery container by the pump, and the valve 29 'is opened when the pressure of the gas in the recovery container falls below the atmospheric pressure. Thus, the outside air is introduced from the outside air inlet 70 into the container to be collected and filled as a dilution gas.
[0031]
FIG. 1 is a flowchart showing an overall configuration of the present invention including a pressurizing unit 22 and a liquefying unit 23 for liquefying and collecting SF6, showing an embodiment.
The details of the gas separation unit 21 in the figure are shown in the flow chart of the embodiment in FIG. 2 (A) or FIG. 2 (B), which applies here. The recovered gas is connected to the recovered gas inlet 1 of the gas separation unit 21 from the recovered gas outlet 1 ′ of the recovered container 26, and the SF6 gas concentrated in the gas separation unit 21 is pressurized from the SF6 gas outlet 3 The separated gas mainly composed of the other dilution gas is returned to the exhaust gas inlet 2 ′ of the recovery container 26 from the exhaust gas outlet 2. The pressurizing unit 22 includes a buffer tank 30, a pressurizing pump 31, and a pressure reducing valve 32 as a return circuit so as not to overpressurize more than a certain pressure.
The pressurized SF6 gas is sent to the liquefying unit 23, cooled and liquefied, and stored in the storage tank 24. The liquefying unit 23 includes a cooler 33, electromagnetic valves 34 and 37, and a liquefaction tank 35, and is cooled by the cooler 33 and sent to the liquefaction tank 35 to be cooled and liquefied.
[0032]
As long as the SF6 gas entering the liquefaction unit 23 is not 100% pure, the SF6 gas is liquefied in the liquefaction tank 35 and taken out to the storage tank 24, so that the impure gas that is not liquefied is accumulated. Although it is necessary to take it out and return it to the upstream part from the gas separation part, the description of this structure is omitted in FIG. Since the SF6 gas is liquefied and the pressure in the container to be recovered falls below a predetermined value as the recovery operation progresses, the valve 29 is opened from the gas supply unit 25 to introduce and fill the gas, and the gas separation unit 21 The gas pressure required for the operation is maintained. For example, there is a method in which the gas supply unit 25 includes a nitrogen gas cylinder 27 and a pressure reducing valve. Alternatively, as shown as the gas supply unit 40, after taking outside air from the filter 41 and increasing the pressure by the compressor 42, the outside air from which moisture has been removed by the dryer 43 may be supplied as a dilution gas connected to the supply outside air outlet 44 and the valve 29. Good.
[0033]
FIG. 2 (A) is a flow diagram of a gas separation unit using molecular sieve charcoal that strongly adsorbs SF6 gas as a target gas to the adsorbent and hardly adsorbs a diluent gas such as nitrogen gas.
In this example, the gas from the collection target container 26 such as a transformer is introduced from the inlet 1 of the collection target gas, the electromagnetic valves 8 and 10 are opened and introduced into the adsorption cylinder 4 to adsorb the SF6 gas to the adsorbent, and the adsorption Nitrogen gas or the like, which is a dilution gas, is taken out from the other end of the cylinder 4 separately from the SF6 gas, and stored in the exhaust gas tank 6 via the solenoid valves 14 and 9. The exhaust gas is pressurized and discharged by the pump 7 through the exhaust gas outlet 2, and is returned to the recovery container 26 shown in FIG. The gas to be recovered introduced from the inlet 1 is connected to the pressure sensor 36 and the SF6 gas concentration sensor 20, and the pressure and concentration are measured.
[0034]
The gas to be collected is introduced into the adsorption cylinder 4 and stopped before the adsorbent adsorbs the SF6 gas and becomes full (adsorption saturation). Perform the process.
That is, the solenoid valves 8, 10, 16, 11, 14 are closed, all the solenoid valves of the adsorption cylinder 5 are closed, the pressure equalizing solenoid valve 17 is opened, and the nitrogen gas floating in the adsorption cylinder 4 is adsorbed. Move toward 5 with some SF6 gas.
[0035]
After that, the solenoid valve 17 is closed, and the SF6 gas adsorbed to the adsorbent in the adsorption cylinder 4 opens the solenoid valves 11 and 18, and the SF6 gas concentrated by the vacuum pump 7 is removed from the SF6 gas outlet 3 as shown in FIG. To the buffer tank 30 shown in FIG.
In this step, the SF6 gas adsorbed on the adsorbent in the adsorption cylinder 4 is desorbed by depressurizing the inside of the adsorption cylinder, concentrated and taken out from the SF6 gas outlet 3, and the adsorption capacity of the adsorbent is regenerated. This is called the regeneration process.
[0036]
The adsorption cylinder 5 introduces the gas to be collected through the electromagnetic valve 12, adsorbs the SF6 gas to the adsorbent, opens the electromagnetic valves 15 and 9, and discharges the nitrogen gas to the exhaust gas tank 6 that suppresses the pulsation of the PSA operating pressure. In the same manner as in the above-described steps, the gas is discharged through the outlet 2 of the exhaust gas by the pump 7 and returned to the container 26 to be collected shown in FIG. When the SF6 concentration in the gas to be recovered falls below a certain value by the SF6 gas concentration sensor, the SF6 concentration in the separated diluted gas (nitrogen gas) becomes very small, so the solenoid valve 51 is closed and returned to the recovery container. Then, the valve 52 is opened and discharged from the discharge port 50 into the atmosphere. When the pressure of the pressure sensor 36 is below a certain value, dilution gas or outside air is introduced into the collection container from the gas supply unit. By this method, gas separation is performed while repeating the pressure adsorption process, the pressure equalization process, and the regeneration process in the gas separation unit.
In this way, the gas separation is performed by taking the gas to be recovered, which is the raw material gas, from the inlet 1 of the gas to be recovered, and separating the SF6 gas by adsorbing the SF6 gas to the adsorbent and taking it out as the SF6 gas concentrated in the regeneration process. Sent from 3. On the other hand, nitrogen gas or the like as dilution gas is stored in the exhaust gas tank 6 and returned to the container 26 by the pump 7. The above steps are alternately performed by two adsorption cylinders, and the mixed gas is continuously separated into SF6 and dilution gas, one is collected and the other is returned to the container to be collected.
[0037]
Fig. 2 (B) shows the configuration of a gas separation unit using a zeolite that hardly adsorbs the target gas, SF6 gas, and adsorbs the diluent gas, nitrogen gas, moisture, oxygen, etc. better. FIG.
The gas to be recovered, which is the raw material gas, is introduced from the inlet 1 of the gas to be recovered, the solenoid valves 8 and 10 are opened, and the gas is introduced into the adsorption cylinder 4. The SF6 gas that hardly adsorbs from the gas is condensed and sent from the SF6 gas outlet 3 to the buffer tank 30 in FIG.
[0038]
The adsorbent in the adsorption cylinder 4 adsorbs nitrogen gas, which is a dilution gas, and becomes full (adsorption saturation) shortly before the introduction of the raw material gas is stopped, and the pressure is equalized between the adsorption cylinder 5 after the regeneration process is completed. The process of conversion is performed.
That is, the solenoid valves 8, 18, 11, and 13 are closed, the solenoid valves 14, 15, 10, and 12 are opened, and the SF6 gas floating in the adsorption cylinder 4 is moved toward the adsorption cylinder 5 together with some nitrogen gas. After moving, the solenoid valves 10, 14, 13 are closed, the solenoid valves 11, 9, 8, 12, 15, 18 are opened, the raw material gas is introduced into the adsorption cylinder 5, and the concentrated SF6 gas is Since the gas is led out from the SF3 gas outlet 3 through 15 and 18, the adsorption cylinder 5 enters the adsorption process.
[0039]
Nitrogen gas, etc., which is a dilution gas adsorbed by the adsorbent in the adsorption cylinder 4, is released through the solenoid valves 11 and 9 when the adsorbed nitrogen gas is released by lowering the pressure in the adsorption cylinder. After being stored in the gas tank 6, the valve 51 is opened by the pump 7 and sent out from the outlet 2 of the exhaust gas to the collection container 26 of FIG. Again, the SF6 gas concentration and pressure in the collected gas taken in at the inlet 1 are measured by the SF6 gas concentration meter 20 and the pressure sensor 36, and separated after the SF6 gas concentration in the collected gas falls below a certain value. Since the concentration of SF6 contained in the diluted gas is very low, valve 51 is closed, 52 is opened, and the gas is released into the atmosphere.
Thus, in both (A) and (B), the mixed gas is continuously separated into SF6 and dilution gas by alternately repeating the adsorption process, pressure equalization process, and regeneration process with two adsorption cylinders, and one is recovered. At the same time, the other is returned to the container to be collected.
[0040]
Note that the pressure equalization step in the description of the flow charts of FIGS. 2A and 2B can be omitted depending on the capability of the apparatus.
Next, FIG. 4 shows an example of filling. This will be described using this.
The gas supply unit 100 capable of supplying SF6 gas and dilution gas by the SF6 gas supply source 60 constituted by the SF6 gas cylinder 55 and the pressure reducing valve 57, the dilution gas supply source 25 constituted by the nitrogen gas cylinder 27 and the pressure reduction valve 28, and the gas shown in FIG. In the gas separation / recovery / filling device having the pressure sensor 36 and the concentration sensor 20 in the separation unit 21, the container 26, the gas supply unit 100, and the gas separation unit are connected by a conduit, and the pressure sensor 36 and the concentration sensor 20 are connected to each other. The mixed gas in the container to be collected is connected by a conduit, and the pressure and concentration of the mixed gas are measured. Although not shown in the figure, the pressure sensor 36 and the concentration sensor 20 are connected by a signal line. Also connected to the control unit, which is omitted in the figure, is connected to the gas supply unit through a signal line from the control unit, and is supplied from the gas supply unit 100 to the recovery container 26 according to instructions from the control unit. And SF6 gas is introduced in a controlled manner. The diluent gas is introduced into the collection target container 26 by opening the valve 29 'in accordance with the instruction of the control unit, and after a certain amount of outside air remaining in the container is discharged from the collection target container 26, the SF6 gas is also opened through the valve 29. The pressure and concentration inside the container to be collected are detected by the pressure sensor 36 and the concentration sensor 20, and the SF6 gas and the dilution gas are supplied from the gas supply unit while controlling the SF6 gas and the dilution gas so as to reach a predetermined filling pressure (filling )
[0041]
Next, another embodiment will be described.
A gas supply unit 100 that can supply SF6 gas and dilution gas by a dilution gas supply source 25 constituted by an SF6 gas supply source 60, a nitrogen gas cylinder 27, and a pressure reduction valve 28 constituted by a gas separation unit 21, an SF6 gas cylinder 55, and a pressure reduction valve 57. 2 and the pressure sensor 36 and the concentration sensor 20 in the gas separation unit 21 shown in FIG. 2 are omitted in the drawing, but in the gas separation recovery and filling apparatus having the control unit, the container 26 and the gas supply unit 100 are connected to each other. Connected with a conduit, the mixed gas in the container 26 to be collected is connected to the gas separation unit 21, the pressure sensor 36, and the concentration sensor 20 with a conduit, and the pressure and concentration of the mixed gas are measured. Although signal lines are omitted,
[0042]
The pressure sensor, the concentration sensor, and the control unit are connected by a signal line, and further, the control unit, the gas separation unit, and the gas supply unit are connected, and the control unit, the gas separation unit, and the gas supply unit are further connected. Connected by a signal line, SF6 gas and dilution gas are introduced from the gas supply unit by opening and closing the valves 29 ′ and 29 by the control unit, respectively. After 29 ′ is opened and introduced, a certain amount of outside air remaining in the container is discharged from the container to be collected 26, and then SF6 gas is introduced with the valve 29 opened to reduce the pressure and concentration in the container to be collected. While supplying gas from the gas supply unit 100 so that the predetermined filling pressure and concentration are detected while being detected by the pressure sensor 36 and the concentration sensor 20, the mixed gas in the container to be recovered is introduced into the gas separation unit 21 and SF6 gas is supplied. And the diluted gas containing the outside air. The outlet gas inlet 2 ′ is connected and returned, and the dilution gas containing the outside air is opened to open the valve 52 and discharged out of the container to be recovered from the discharge port 50, and the air remaining in the container to be recovered 26 The filling time was shortened by filling SF6 gas while discharging etc.
Note that the necessary gas may be returned to the container to be recovered. The dilution gas may be returned to the container to be recovered as necessary from the relationship between the detected pressure and concentration, and the SF6 gas may be discharged out of the container to be recovered.
[0043]
【The invention's effect】
According to the present invention, it is possible to recover the SF6 gas in the container to be recovered without releasing the mixed gas containing the diluted SF6 gas into the atmosphere.
Further, when refilling, the separated and concentrated SF6 gas is led out to a container such as a transformer, and the dilution gas is led out of the container, so that air or the like can be discharged while filling and the time can be shortened.
[Brief description of the drawings]
FIG. 1 is a flowchart showing the overall configuration of the present invention.
FIG. 2 (A) and FIG. 2 (B) are flow charts showing the detailed configuration of a gas separation unit 21. FIG.
FIG. 3 is a flow diagram showing the state of interconnection between a container to be collected 26, a gas extraction unit 66, and a gas separation unit 21;
FIG. 4 is a flow diagram when an exhaust gas recovery container 63 is connected to the exhaust gas outlet 2 of the gas separation unit 21 and a gas supply unit 100 is connected to the recovery container 26;
[Explanation of symbols]
1 Collected gas inlet
1 'Collected gas outlet
2 Exhaust gas outlet
2 'exhaust gas inlet
3 SF6 gas outlet
4 Suction cylinder
5 Suction cylinder
6 Exhaust gas tank
7 Pump
8-19 Solenoid valve
20 SF6 gas concentration sensor
21 Gas separation unit
22 Pressurizing part
23 Liquefaction part
24 storage tank
25 Nitrogen gas supply unit
26 Collected containers
27 Nitrogen gas cylinder
28 Pressure reducing valve
29 Solenoid valve
29 'Solenoid valve
30 Buffer tank
31 Pressurizing pump
32 Pressure reducing valve
33 Cooler
34 Solenoid valve
35 Liquefaction tank
36 Pressure sensor
37 Solenoid valve
40 Outside air supply section
41 Air filter
42 Air pump
43 Hair dryer
44 Supply outside air outlet
51 Solenoid valve
52 Solenoid valve
55 SF6 gas cylinder
57 Pressure reducing valve
63 Exhaust gas collection container
64 Solenoid valve
64 'solenoid valve
65 Booster pump
66 Gas outlet
67 Solenoid valve
68 Solenoid valve
69 Pressure reducing valve
70 Outside air intake
100 Gas supply unit

Claims (6)

  In a gas separation / recovery / filling device that separates a gas from a gas to be recovered mixed with SF6 gas and a diluent gas, the container to be recovered and a gas separation unit are connected by a conduit, and the gas to be recovered in the container to be recovered is separated into the gas A gas separation / recovery / filling device configured to collect one of the separated dilution gases and return the other SF6 gas to the collection target container via a conduit and fill the separated recovery gas. In a gas separation recovery filling method for separating a gas from a mixed gas of SF6 gas and dilution gas in a container to be recovered, a step of introducing the mixed gas from the container to be recovered to a gas separation part through a conduit, and the gas separation The step of separating the mixed gas into SF6 gas and diluent gas, the step of collecting one of the separated diluent gases, and the step of filling the other SF6 gas back into the container to be collected through a conduit are performed simultaneously. A gas separation recovery filling method characterized by the above.   A step of supplying gas from the gas supply unit to the recovery container; and when the pressure of the gas in the recovery container is lower than a predetermined value, the recovery container supplies dilution gas or SF6 gas from the gas supply unit. 3. The gas separation / recovery / filling method according to claim 2, further comprising an introduction step.   In a gas separation / recovery / filling device comprising a gas separation unit that separates a gas from a gas to be collected mixed with SF6 gas and a dilution gas, a gas supply unit configured to take outside air with an air pump and a dryer, and a liquefaction recovery unit. The recovery container and the gas separation part are connected by a conduit, and the gas to be recovered in the recovery container is separated into SF6 gas and dilution gas by the gas separation part, and at the same time the SF6 gas is recovered by the liquefaction recovery part. The other diluted gas is returned to the container to be collected by a conduit and filled, and when the pressure of the container to be collected becomes lower than a predetermined value as the separation and recovery operation proceeds, the gas supply is performed. A gas separation / recovery / filling apparatus, wherein outside air is introduced into the container to be collected from a section.   In a gas separation recovery and filling apparatus having a gas separation unit, a gas supply unit capable of supplying SF6 gas and a dilution gas, a pressure sensor, and a concentration sensor, the container to be recovered, the gas supply unit, and the gas separation unit are connected by a conduit, and the recovery target While controlling the SF6 gas and dilution gas from the gas supply unit while controlling the pressure and concentration inside the container while controlling the SF6 gas and dilution gas, the gas to be recovered is supplied to the gas separation unit. A gas separation / recovery / filling device, wherein SF6 gas and dilution gas are separated into SF6 gas and dilution gas, and SF6 or dilution gas separated according to the detected pressure and concentration is returned to the container to be collected.   In a gas separation recovery and filling apparatus having a gas separation unit, a gas supply unit capable of supplying SF6 gas and a dilution gas, a pressure sensor, and a concentration sensor, the container to be recovered, the gas supply unit, and the gas separation unit are connected by a conduit, and the recovery target While detecting the pressure and concentration in the container, SF6 gas and dilution gas are introduced from the supply unit so that the predetermined filling pressure and concentration are obtained, and further, the mixed gas is introduced from the container to be collected into the gas separation unit, and SF6 A gas separation / recovery / filling device configured to separate a diluent gas containing gas and outside air, return SF6 gas to the container to be collected, and discharge the diluent gas containing outside air to the outside of the container to be collected.

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