JPS6223808B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a transformer using electrical insulating oil;
Concerning gas extraction equipment used for analysis of dissolved gas in electrical insulating oil necessary for early abnormality diagnosis of electric power equipment such as reactors, or analysis of dissolved gas in water supplied to water turbines and cooling equipment. .

For example, in the case of electrical insulating oil, the gas extraction equipment for dissolved gas in electrical insulating oil is generally a gas extraction equipment using a Trithierly vacuum, a gas extraction equipment using a combination of a mercury diffusion pump and a Teppler pump, and a gas extraction equipment using a vacuum pump and a transfer pump. There are gas extraction devices that use valves. However, the gas extraction device using the Trithierly vacuum uses a level glass bottle containing mercury to create a so-called Trithierly vacuum, and releases the dissolved gas in the electrical insulating oil into the vacuumed glass container. This method uses mercury and a glass container, which has 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 Trithiery vacuum method described above, there is a risk of mercury vapor escaping and damage to the glass container. In addition, a gas extraction device that uses a vacuum pump and a moving valve uses a vacuum pump to maintain a vacuum inside the cylinder, releases dissolved gas into the cylinder, and operates the moving valve when degassing is completed from the electrical insulating oil. 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. There are drawbacks such as difficulty in measuring the amount of dissolved gas with high accuracy.

In addition to these devices, there is also a dissolved gas extraction device that uses a carrier gas replacement method to extract dissolved gas by replacing the dissolved gas in electrical insulating oil with a carrier gas, but in this case, when the concentration of dissolved gas is low, It is difficult to measure, and 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, and also eliminates the risk of mercury vapor escaping.
Moreover, it is an object of the present invention to provide a gas extraction device that can efficiently and sufficiently degas even highly soluble dissolved gases.

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 switch connected to the deaeration container 1. A sample oil sampler 4 can be connected to the valve 3. Further, the deaeration container 1 has a valve 5.
The cylinder chamber 7 of the reciprocating piston device 7 via
a, and a valve 8 is connected to the cylinder chamber 7a.
A vacuum pump 10 is connected via a three-way switching valve 9.

On the other hand, a conduit 11 connected to the three-way switching valve 9
There are multiple (two in the figure) branch conduits 12.
a, 12b are connected to gas sample tubes 14a, 14b via switching valves 13a, 13b, respectively.

Therefore, when each of the switching valves 13a and 13b is in the illustrated position, the gas passing through the conduit 11 is transferred to the switching valve 1.
Gas sample tubes 14 are passed through 3a and 13b, respectively.
a, 14b, while the switching valves 13a,
13b is rotated 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 is further transferred to the conduits 16a, 16.
b to an analytical device (not shown) such as a gas chromatograph.

Further, the conduit 11 is provided with a pressure sensor 17, and a gas sample tube 1 is passed through the conduit 11.
It is arranged so that the amount of gas supplied to 4a, 14b can be measured.

Incidentally, the reciprocating piston device 7 is driven by a differential pressure piston device 20. That is, the reciprocating piston device 7 has a cylinder chamber 7a and a cylinder chamber 7, as shown in FIG.
The piston 7b has a piston 7b that slides inside a, and rubber gaskets 25, 25 are provided on the outer peripheral surface of both ends of the piston 7b in the axial direction, and the outer peripheral surface between these rubber gaskets 25, 25 has a circumferential surface. Five to seven grooves are formed, and the spaces between these grooves are filled with a non-drying semi-solid filler 26 such as a liquid gasket or grease. The airtightness is maintained by the non-drying semi-solid filling 26, and leakage of the non-drying semi-solid filling 26 is prevented by a pair of rubber gaskets 25, 25. A large-diameter piston 22 is connected to this piston 7b via a piston rod 21, and a cylinder chamber 2 of the large-diameter piston 22 on the piston 7b side
0a is connected to the vacuum pump 10 via a switching valve 23, and the other side cylinder chamber 20b of the large diameter piston 21 is connected to the vacuum pump 10 via a switching valve 24.
It is connected to the.

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 by the differential pressure on both sides thereof. As a result, the piston 7b moves to the right in the figure, and the piston 7b retreats accordingly. On the other hand, the switching valve 23
When the cylinder chamber 20a is connected to the vacuum pump 10 through the switching valve 24 and the cylinder chamber 20b is opened to the atmosphere through the switching valve 24, the large diameter piston 22
At the same time, the piston 7b moves to the left, and the dissolved gas can be transferred to the gas sample tubes 14a and 14b as described above.

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 connect the sample oil sampler 4 to the atmosphere side by connecting the sample oil sampler 4 to the switching valve 3. Switch to drain some of the electrical insulating oil from the sample and eliminate air from the connection. Next, the piston 7b of the reciprocating piston device 7 is actuated rightward in the figure by the differential pressure piston device 20 to increase the volume of the cylinder chamber 7a. Therefore, by opening the valves 5 and 8 and operating the three-way switching valve 9 to connect the cylinder chamber 7a and each gas sample tube 14a, 14b to the vacuum pump 10, and operating the vacuum pump 10, the cylinder chamber 7a , the degassing container 1, 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.

By 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 in a vacuum state.
The gas also flows into the gas sample tubes 14a and 14b and is accumulated therein.

Therefore, the valve 5 is closed and the cylinder chamber 7a is closed.
The reciprocating piston device 7 is activated by operating the differential pressure piston device 20 while maintaining the three-way switching valve 9 in a state where the gas sample tubes 14a and 14b communicate with each other.
The piston 7b of is moved to the left. Therefore, the movement of the piston 7b forces the dissolved gas in the cylinder chamber 7a into the gas sample tubes 14a,
14b.

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 by opening the valve 5, the dissolved gas in the electrical insulating oil in the degassing container 1 is released from the electrical insulating oil and inside the cylinder chamber 7a. The accumulated dissolved gas is sequentially transferred and charged into the gas sample tubes 14a and 14b by repeating the above-described operation.

In this way, by repeatedly performing the degassing and extraction operation for dissolved gases on the same sample of electrical insulating oil, dissolved gases that have high solubility and are difficult to degas can also be efficiently extracted.

The amount of dissolved gas extracted is measured by a pre-calibrated pressure sensor 17, while the dissolved gas charged into the gas sample tubes 14a and 14b is transferred to the carrier gas supply tube by switching the switching valves 13a and 13b, respectively. By supplying carrier gas from 15 to gas sample tubes 14a, 14b, conduits 16a, 16b are supplied via switching valves 13a, 13b.
The sample is then sent to an analytical device such as a gas chromatograph as appropriate.

As described above, the present invention allows the piston of the reciprocating piston device to connect to the cylinder by a pair of rubber gaskets and a non-drying semi-solid filling filled in the 5 to 7 grooves between them. Since the space is sealed, there is no gas leakage, and by reciprocating the piston, dissolved gas can be repeatedly extracted from the liquid, and even dissolved gases with high solubility can be extracted sufficiently. can do. Moreover, the entire device 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 vacuum and atmospheric pressure, a mechanical drive device or a special pressurizing device is provided to drive the reciprocating piston device. This is not necessary, and the vacuum pump for evacuating the inside of the degassing container can also be used as a driving source.

[Brief explanation of the drawing]

FIG. 1 is a schematic system diagram of the gas extraction device of the present invention;
FIG. 2 is an enlarged sectional view of the main part of FIG. 1. 1... Deaeration container, 2... Stirring device, 4... Sample oil sampler, 5, 8... Valve, 7... Reciprocating piston device, 9... Three-way switching valve, 10... Vacuum pump,
14a, 14b... Gas sample tube, 20... Differential pressure piston device, 25... Rubber gasket, 26...
filling.

Claims (1)

[Claims] 1. In a gas extraction device used for analysis of dissolved gas in liquid, etc., there is a degassing container for separating dissolved gas from the liquid sample, and a device that extracts dissolved gas from the degassing container and transfers it to a gas sample tube. a reciprocating piston device that causes discharge, a differential pressure piston device that reciprocates due to the difference between the vacuum generated by a vacuum pump and atmospheric pressure and drives the reciprocating piston device, the degassing container and the reciprocating piston. The reciprocating piston device comprises a vacuum pump that is connected to the cylinder chamber and gas sample tube of the device via a switching valve, and brings the degassing container and the cylinder chamber to a predetermined vacuum state before starting the gas extraction operation. It has a cylinder and a piston that slides inside the cylinder, rubber gaskets are provided on the outer circumferential surface of both axial ends of the piston, and a plurality of circumferential grooves are formed on the outer circumferential surface between these rubber gaskets,
A gas extraction device characterized in that each groove is filled with a non-drying semi-solid filler.