JP3130290B2 - Gas recovery equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to relates to a gas recovery unit for recovering a gas such as SF 6 _(sulfur hexafluoride) and Freon.

[0002]

2. Description of the Related Art Generally, a gas recovery apparatus of this type includes a compressor connected to a device to be recovered and a gas compressed by the compressor, as disclosed in, for example, Japanese Patent Application Laid-Open No. 8-93997. And a condenser for cooling and liquefying the liquefied gas, and a recovery container (tank or cylinder) for containing the liquefied gas. Further, there is also known an apparatus which does not include a condenser or a cooling device and stores the gas compressed by a compressor in a recovery container as it is.

[0003]

However, in the above-mentioned conventional gas recovery apparatus, the gas in the equipment to be recovered is only sucked by the suction force accompanying the operation of the compressor. Remains without being collected. In particular, when the volume of the equipment to be recovered is large and a large amount of gas is recovered, for example, in the case of SF ₆ gas used in gas circuit breakers (GCB) and gas insulated substations (GIS) used in power substations The amount recovered is very large and the amount remaining remains large. The remaining gas is released into the atmosphere, which contributes to global warming.

In order to solve this problem, it is conceivable to equip a gas recovery device with a vacuum pump and evacuate and recover the gas in the device to be recovered by the vacuum pump. However, since a vacuum pump is originally designed to open the exhaust side (exit side) to the atmosphere and is usually designed to loosely seal the exhaust side, a general-purpose vacuum pump is used. Is connected to the compressor, there is a possibility that air will leak if the pressure on the exhaust side of the vacuum pump becomes negative. If the sealing performance on the exhaust side of the vacuum pump is increased in order to prevent this air leak, the cost of the vacuum pump and hence the gas recovery device increases.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and it is an object of the present invention to use a general-purpose vacuum pump to completely recover gas in a device to be recovered by evacuation. It is intended to provide a gas recovery device capable of effectively preventing the occurrence of air leak on the exhaust side of the gas.

[0006]

To solve the above-mentioned problems, the present invention relates to a gas recovery apparatus for recovering gas from a device to be recovered by a compressor connected to the device to be recovered. A vacuum pump that evacuates and supplies the compressor to the compressor via a supply pipe, and a pressure-holding valve that is provided in the supply pipe and holds the pressure on the vacuum pump at a predetermined pressure. I do. In this configuration, the gas is evacuated from the device to be recovered by the vacuum pump, and the gas can be completely recovered without leaving the gas in the device to be recovered. Moreover, since the pressure on the exhaust side of the vacuum pump, that is, the side connected to the compressor, is maintained at a predetermined pressure by the pressure-holding valve, the pressure is reduced to a negative pressure, and no air leak occurs.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a gas recovery device A according to one embodiment of the present invention. This gas recovery device A is a gas circuit breaker (GCB) of a substation or a gas insulated substation (GIS).
(Hereinafter referred to as a gas circuit breaker B) is to liquefy the SF ₆ gas and collect it in the cylinder 1 of the cylinder unit C.

The cylinder unit C comprises a cylinder 1 for collecting liquefied gas, a weighing machine 2 for measuring the weight of the cylinder 1 to measure the amount of liquefied gas in the cylinder 1, and a truck (not shown) for placing and transporting these. And a plurality (two in the figure) are prepared according to the total volume of the liquefied gas to be recovered. The gas recovery device A and the plurality of cylinder units C,... Are carried by a vehicle into the substation at the time of periodic inspection of the gas circuit breaker B and the like. , And each cylinder unit C is connected to the gas recovery device A via the hose 4.

The gas recovery device A is a motor-driven type
A stage compressor 11, a vacuum pump 12, and a cooling device 13 are provided. The compressor 11 and the vacuum pump 12 evacuate and compress the SF ₆ gas from a gas circuit breaker B or the like of a substation, and further compress the SF ₆ gas. The liquefied SF ₆ gas is temporarily recovered in the liquefied gas recovery cylinder 1 of each cylinder unit C.

The vacuum pump 12 has an intake side (inlet side) connected to a gas circuit breaker B or the like, which is a device to be recovered,
The exhaust side (outlet side) is the feed line 16 and the surge tank 17
Is connected to the compressor 11 via a gas circuit breaker B to evacuate the SF ₆ gas from the gas circuit breaker B or the like and feed the gas to the compressor 11 side. A pressure holding valve 18 for maintaining the pressure on the vacuum pump 12 side at a predetermined pressure (for example, 0.2 kgf / cm ² ) is provided in the feed line 16.
Is provided. The cooling device 13 forms a refrigerant circuit including a refrigerator 21, an expansion valve 22, a heat exchanger 23, and the like, and uses the SF ₆ gas compressed by the compressor 11 to a heat exchanger 23 (a condenser on a gas pipe side). It is designed to cool down.

Further, the gas recovery device A includes the compressor 11,
A pressure reducing valve 27 is provided in a pipeline 26 that bypasses the vacuum pump 12 and the cooling device 13 and connects the gas circuit breaker B side to the cylinder unit C side. Then, the liquefied gas in the liquefied gas recovery cylinder 1 of each cylinder unit C is supplied to a gas circuit breaker B or the like.
When returning to, the liquefied gas in the cylinder 1 is spontaneously vaporized, and is returned to the gas circuit breaker B or the like through the pipe 26 while being reduced to a predetermined pressure by the pressure reducing valve 27 so as to be filled.

In FIG. 1, reference numeral 31 denotes an oil filter provided in the feed line 16 on the exhaust side of the vacuum pump 12;
Reference numeral 2 denotes a pressure-holding valve provided in a pipe 33 that communicates between the exhaust side and the suction side of the vacuum pump 12. The set pressure of the pressure-holding valve 32 is equal to the set pressure of the pressure-holding valve 18 in the feed pipe 16. Is set to a higher value (eg, 0.4 kgf / cm ² )
When the pressure on the exhaust side of the vacuum pump 12 exceeds this set value, the pressure is leaked. Also,
36 is a filter, 37 is a 2-port solenoid valve, 38 is a 3-port solenoid valve, 39 is an on-off valve, 40 is a strainer, 41 is a pressure gauge, 42 is a vacuum gauge, 43 is a thermometer, and 44 is a safety valve.

Next, using the gas recovery device A and the plurality of cylinder units C,.
An operation procedure for recovering the SF ₆ gas from the apparatus and returning it to the original state after the inspection of the gas circuit breaker B and the like will be described.

First, after the gas recovery device A and a plurality of cylinder units C,... Are carried into a predetermined place in the substation, the gas recovery device A is connected via a hose 3 to a gas circuit breaker B or the like as a device to be recovered. In addition, the gas recovery device A and the liquefied gas recovery cylinder 1 of each cylinder unit C are connected to the hose 4.
Connect through.

Subsequently, in the gas recovery device A, the compressor 11 and the vacuum pump 12 feed the SF from the gas circuit breaker B to the SF.
₆ gas is evacuated and compressed, and it is further cooled
The liquefied SF ₆ gas is collected in the cylinder 1 of each cylinder unit C. At this time, in each cylinder unit C, the cylinder 1
Is measured and the amount of liquefied gas recovered inside is measured. When the liquefied gas amount reaches the predetermined amount, the two-port solenoid valve 37 of the gas recovery device A corresponding to the cylinder unit C is closed, and the filling and recovery of the liquefied gas into the cylinder 1 is completed. The filling and collection of the liquefied gas into the cylinder 1 of the cylinder unit C is started.

In such gas recovery, the two-stage compressor 11
In addition to suctioning the SF ₆ gas in the gas circuit breaker B etc. by the suction force accompanying the operation of, the SF ₆ gas is sucked and collected by the evacuation by the operation of the vacuum pump 12, so that the gas collection is performed. At the end of the process, no unrecovered SF ₆ gas remains in the gas circuit breaker B or the like. In addition, since the pressure on the exhaust side of the vacuum pump 12, that is, the side connected to the two-stage compressor 11, is maintained at a predetermined pressure by the pressure holding valve 18, it is possible to reduce the pressure to a negative pressure and cause air leak. Absent. For this reason, while using a general-purpose vacuum pump 12, the occurrence of air leak on the exhaust side can be reliably prevented, and the cost can be reduced.

After the recovery of SF ₆ gas from the gas circuit breaker B and the like, and after the inspection of the gas circuit breaker B and the like, the liquefied gas recovered in the cylinder 1 of each cylinder unit C is gas-blocked. When returning to the container B, the cylinder 1 of each cylinder unit C is set up vertically. Then, the liquefied gas in the cylinder 1 evaporates naturally from the upper part of the cylinder 1,
The gas is discharged into the gas circuit breaker B via the hoses 3 and 4 and the pipeline 26 of the gas recovery device A and returned. At that time, the pipe 2
The pressure is reduced to a predetermined pressure by the pressure reducing valve 27 in 6.

As described above, the gas circuit breakers B to SF ₆
A series of work involving the collection and filling of SF ₆ gas after inspection completion of the gas circuit breaker or the like B to the gas circuit breaker, etc. B of gas is terminated.

It should be noted that the present invention is not limited to the above embodiment, but includes various other forms.
For example, in the above embodiment, the gas circuit breaker (GC
B) or a gas insulated substations (has been described gas recovery device A liquefying the SF ₆ gas in GIS) recovering the cylinder 1 of the cylinder unit C, the present invention may be recovered gases other than SF ₆ gas It can be widely applied to gas recovery devices that recover from equipment. In that case, as a gas recovery device,
As in the embodiment, the gas compressed by the compressor is cooled by the cooling device 13 to be liquefied, and the liquefied gas is not collected in the cylinder 1, but the gas compressed by the compressor is simply used as a cylinder or tank. May be collected in a collection container. In short, when the gas is evacuated from the equipment to be recovered using a vacuum pump separately from the compressor and sent to the compressor side, the pipe between the vacuum pump and the compressor is connected to the vacuum pump side. What is necessary is just to provide a pressure holding valve for maintaining the pressure at a predetermined pressure.

[0020]

As described above, according to the gas recovery apparatus of the present invention, since the gas can be evacuated from the equipment to be recovered by the vacuum pump, the gas can be completely recovered without leaving the gas in the equipment to be recovered. can do. In addition, since the vacuum pump is a general-purpose pump, and the pressure on the exhaust side can be maintained at a predetermined pressure, it is possible to reliably prevent the occurrence of air leaks and to reduce the cost. Is very advantageous.

[Brief description of the drawings]

FIG. 1 is a fluid circuit diagram of a gas recovery device according to an embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List A gas recovery device B gas circuit breaker etc. (device to be recovered) 11 compressor 12 vacuum pump 16 feed line 18 pressure holding valve

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H02B 13/02-13/075 H02B 3/00 F25B 45/00

Claims (1)

(57) [Claims] 1. A gas recovery apparatus for recovering gas from a device to be recovered by a compressor connected to the device to be recovered, wherein the gas is evacuated from the device to be recovered, and the gas is evacuated to the compressor via a feed pipe. A gas recovery device, comprising: a vacuum pump for feeding; and a pressure-holding valve provided in the feed pipe and maintaining a pressure on the vacuum pump side at a predetermined pressure.