JPS588736B2 - gas extraction equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to analysis of dissolved gas in electrical insulating oil, which is necessary for early abnormality diagnosis of electric power equipment such as transformers and reactors that use electrical insulating oil. This invention relates to a gas extraction device used for analyzing dissolved gas in water supplied to water turbines, cooling equipment, etc.

For example, in the case of electrical insulating oil, generally speaking,
Examples of gas extraction equipment for dissolved gas in electrical insulating oil include a gas extraction equipment using a Torrichley vacuum, a gas extraction equipment using a combination of a mercury diffusion pump and a Tebra pump, and a gas extraction equipment using a vacuum pump and a moving valve.

However, the above-mentioned gas extraction device using a Toricherry vacuum creates a so-called Torichley vacuum using a glass leveling bottle containing mercury, and extracts the dissolved gas in electrical insulating oil into the vacuumed glass container. This method uses mercury and a glass container, so there are disadvantages such as the risk of mercury vapor escaping and the glass container being damaged.

In addition, a gas extraction device that uses a combination of a mercury diffusion pump and a Teppler pump uses an oil rotary pump, a mercury diffusion pump, and a Teppler pump to maintain a vacuum inside a glass degassing container, and there is electrical insulation inside the degassing container. This is a method in which oil is injected to release dissolved gas and accumulate it in a gas storage container, but like the aforementioned Torichley vacuum method, there is a risk of mercury vapor escaping and damage to the glass container.

Furthermore, a gas extraction device that uses a vacuum pump and a moving valve uses a vacuum pump to maintain the inside of the cylinder in a vacuum state, releases dissolved gas into the cylinder, and operates the moving valve when the degassing from the electrical insulating oil is completed. This method involves charging the extracted dissolved gas into a gas sample tube, but since the extraction operation can only be performed once on the same sample, it is difficult to sufficiently extract highly dissolved dissolved gas, and it is not possible to accurately extract dissolved gas. There are drawbacks such as difficulty in measuring the amount of dissolved gas.

In addition to these devices, there is also a dissolved gas extraction device that uses a carrier gas replacement method to extract the dissolved gas by replacing the dissolved gas in the electrical insulating oil with a carrier gas, but in this case, if the concentration of dissolved gas is low, the measurement is difficult,
There are drawbacks such as the fact that the amount of electrical insulating oil used as a sample is small, which tends to cause errors in measured values.

In view of these points, the present invention eliminates the need to use a glass device that is at risk of breakage, eliminates the risk of mercury vapor escaping, and eliminates the need for highly soluble dissolved gases. It is an object of the present invention to provide a gas extraction device capable of efficiently and sufficiently degassing.

Embodiments of the present invention will be described below with reference to the accompanying drawings.

In FIG. 1, reference numeral 1 denotes a deaeration container for stirring electrical insulating oil as a sample with a stirring device 2 and separating its dissolved gas, and a switching valve 3 connected to the deaeration container L. This sample oil sampling device 4 can be connected.

Further, the degassing container 1 is connected to a cylinder chamber 7a of a reciprocating piston device 7 via a valve 5, and a vacuum pump 10 is connected to the cylinder chamber 7a via a valve 8 and a three-way switching valve 9. has been done.

On the other hand, a plurality of branch pipes 12a and 12b (two in the figure) are connected to the pipe 11 connected to the three-way switching valve 9, and the branch pipes 12a and 12b are connected to the switching valves 13a and 12b, respectively. Gas sample tubes 14a, 14 via 13b
b is connected.

Thus, when the switching valves 13a and 13b are in the illustrated positions, the gas that has passed through the conduit 11 is supplied to the gas sample tubes 14a and 14b through the switching valves 13a and 13b, respectively, and
On the other hand, while rotating the switching valves 13a, 13b by a predetermined angle, the gas in the gas sample tubes 14a, 14b passes through the switching valves 13a, 13b by the carrier gas connected to the switching valves 13a, 13b, and further, the conduit 16a, 16b
Analyzers such as gas chromatographs (not shown)
It is arranged to be sent to

Further, the conduit 11 is provided with a pressure sensor 17, so that the amount of gas supplied to the gas sample tubes 14a, 14b through the conduit 11 can be measured.

By the way, the reciprocating piston device 7 is driven by a differential piston device 20.

That is, the piston 7b of the reciprocating piston device 7
A large-diameter piston 22 is connected to the piston rod 21 via a piston rod 21, and a cylinder chamber 20a on the piston 7b side of the large-diameter piston 22 is connected to the vacuum pump 10 via a switching valve 23.
The other cylinder chamber 20b of the large-diameter piston 21 is connected to the vacuum pump 10 via a switching valve 24.

Therefore, when the switching valve 24 is switched to connect the cylinder chamber 20b to the vacuum pump 10, and the other cylinder chamber 20a is opened to the atmosphere by the switching valve 23, the large diameter piston 22 is moved as shown in the figure by the differential pressure on both sides. The piston 7b moves to the right, and the piston 7b retreats accordingly.

On the other hand, when the cylinder chamber 20a is connected to the vacuum pump 10 via the switching valve 23 and the cylinder chamber 20b is opened to the atmosphere via the switching valve 24, the large-diameter piston 22 and Tomoko piston 7b move to the left, as described above. The dissolved gas can be transferred to the gas sample tubes 14a and 14b.

Therefore, in order to extract dissolved gas in electrical insulating oil using the above device, first connect the sample oil sampler 4 to the switching valve 3, and then switch the switching valve 3 so that the sample oil sampler 4 communicates with the atmosphere. , while draining some of the electrical insulating oil from the sample, exclude air from the connection.

Next, the differential pressure piston device 20 causes the piston 7b of the reciprocating piston device T to move toward the right in the figure to increase the volume of the cylinder chamber 7a.

Therefore, the valves 5 and 8 are opened and the three-way switching valve 9 is operated to remove the cylinder chamber 7a and each gas sample tube 14a, 14.
b is connected to the vacuum pump 10, and the vacuum pump 10
By operating the cylinder chamber 7a, deaeration container 1,
Then, the insides of the gas sample tubes 14a, 14b, etc. are brought into a predetermined vacuum state.

When the inside of the cylinder chamber 7a etc. reaches a predetermined vacuum state in this way, the three-way switching valve 9 is switched to cut off the communication between the cylinder chamber 7a, gas sample tubes 14a, 14b, etc. and the vacuum pump 10, and the switching valve 3 is switched off. When opened, the electrical insulating oil in the sample oil sampler 4 flows into the degassing container 1, and the stirring device 2 is operated to stir the electrical insulating oil.

Due to the stirring, the dissolved gas in the electrical insulating oil is separated and released from the electrical insulating oil, and the released dissolved gas is kept in the cylinder chamber 7a and the gas sample tube 14 which are kept in a vacuum state.
a, 14b and is accumulated therein.

Therefore, while the valve 5 is closed and the cylinder chamber 7a and the gas sample tubes 14a, 14b are in communication with each other, the differential pressure piston device 20 is operated while the three-way switching valve 9 is maintained. Move the piston 7b to the left.

Therefore, due to the movement of the piston 7b, the dissolved gas in the cylinder chamber Ta is forced into the gas sample tubes 14a, 14.
It is transferred and charged to b.

When the gas sample tubes 14a, 14b are completely charged as described above, the valve 8 is closed and the piston 7b of the reciprocating piston device 7 is moved to the right again.

As a result, the inside of the cylinder chamber 7a is brought to a high degree of vacuum again, so that when the valve 5 is opened, the dissolved gas in the electrical insulating oil in the degassing container 1 is released from the electrical insulating oil and accumulates in the cylinder chamber Ia. By repeating the above-described operation, the accumulated dissolved gas is sequentially transferred and charged into the gas sample tubes 14a and 14b.

In this way, by repeatedly performing the degassing extraction operation of the dissolved gas on the same sample of electrical insulating oil, the dissolved W1
Dissolved gases that are difficult to degas with a high level of gas can also be efficiently extracted.

The amount of dissolved gas extracted is measured using a pre-calibrated pressure sensor 11, while the amount of dissolved gas is measured using a gas sample tube 14.
The dissolved gas charged into the switching valves 13a, 14b
3b and supply the carrier gas from the carrier gas supply pipe 15 to the gas sample tubes 14a, 14b through the switching valves 13a, 13b to the conduits 16a, 16b, respectively.
16b, and is sent to an analytical device such as a gas chromatograph as appropriate.

Note that the present invention can be applied to various liquids, such as when extracting and analyzing dissolved gas in water by the same method as described above from water supplied to a water turbine or water supplied to cooling equipment, etc. It is.

Since the present invention is configured as described above, dissolved gas can be repeatedly extracted by reciprocating the piston of the reciprocating piston device, and even dissolved gases with high solubility can be sufficiently extracted. It is extremely small and lightweight, and since mercury is not used to extract dissolved gas, there is no risk of mercury vapor escaping.

Furthermore, since the piston of the reciprocating piston device is caused to reciprocate by the pressure difference between the vacuum and atmospheric pressure, it is necessary to provide a mechanical drive device or a special pressurizing device for driving the reciprocating piston device. The vacuum pump for creating a vacuum inside the degassing container can also be used as a driving source.

[Brief explanation of the drawing]

The drawing is a schematic system diagram of the gas extraction device of the present invention. 1... Deaeration container, 2... Stirring device, 4
...Sample oil sampler, 5,8...Valve, I.
... Reciprocating piston device, 9 ... Three-way switching valve, 10 ... Vacuum pump, 14a, 14b
......Gas sample tube, 20...Differential pressure piston device.

Claims (1)

[Claims] 1. A gas extraction device used for analysis of dissolved gas in a liquid, etc. includes a deaeration container for separating dissolved gas from a sample liquid, and a deaeration container for extracting the dissolved gas from the deaeration container and converting it into a gas. a reciprocating piston device that discharges gas into a sample tube; a differential pressure piston device that reciprocates due to the difference between the vacuum generated by a vacuum pump and atmospheric pressure to drive the reciprocating piston device; and the deaeration container and the reciprocating piston device. A vacuum pump connected to the cylinder chamber of the piston device and the gas sample tube through a switching valve, and which brings the degassing container, cylinder chamber, etc. to a predetermined vacuum state before starting the gas extraction operation. Extraction device.