JPS62261958A - Automatic analyzing device for gas in oil - Google Patents

Abstract

PURPOSE:To obtain a highly reliable analytic value by adding a vacuum pump between a mixing cylinder and a discharge port and increasing the degree of evacuation in a metering valve system. CONSTITUTION:Sample oil 7 is sampled in an extraction cylinder 1 and solenoid valves 19 and 21 are opened; and the flow passage of a three-way solenoid valve 22 is connected to the vacuum pump 23 from the solenoid valve 21 and the vacuum pump 23 is put in operation to generate negative pressure in the piping from a solenoid valve 17 to the solenoid valve 21. Then, the solenoid valves 19 and 21 are closed to switch the flow passage of the three-way solenoid valve 22 from the solenoid valve 21 to the discharge port 25 and then the vacuum pump 23 is turned off. A piston 2 at the upper-limit position in the cylinder 1 is lowered to the lower-limit position the solenoid valves 9, 10, 11, 12, and 15 closed, the 2nd chamber 41 at the upper part in the cylinder 1 is evacuated and the pressure in the 1st chamber 40 at the lower part rises, so the sample oil 7 sampled in he 1st chamber 40 is injected strongly into the 2nd chamber 41 in the cylinder 1 through the thin hole 6 at the upper part of the piston 2 and the area is in a vacuum state at this time, so the dissolved gas in the sample oil 7 is separated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical field to which the invention pertains] The present invention relates to an automatic analyzer for gas dissolved in sample oil collected from an oil-immersed transformer or the like.

[Prior art and its problems]

When a thermal or electrical abnormality occurs inside an oil-filled electrical device, such as a transformer, the insulating oil or insulation material around it decomposes, producing gas. These gases dissolve in the insulating oil and the concentration of the gases in the oil increases, so the gases dissolved in the oil (hereinafter referred to as gases in the oil) are extracted and analyzed, and based on the analysis results, the inside of the transformer is detected. Methods for diagnosing abnormal conditions are already well known, and because abnormal conditions can be detected early, they are widely used and effective both domestically and internationally.

Methods for analyzing gas in oil include (1) extracting gas in oil using a Torricelli vacuum using mercury, and analyzing the extracted gas with a gas chromatograph (2) using a mercury diffusion pump and a Tepra pump. However, while these methods are easy to implement, they also have the following problems.

(1) Since the operation is performed manually or semi-automatically, human labor is required throughout the entire process from start to finish. (3) Since mercury is used, there is a risk of harm to the human body due to deterioration of the working environment due to volatilization of mercury.

(4) The device is made of glass and is easily damaged.

In order to solve the above problems, the inventors of the present invention applied for a patent application for an automatic gas-in-oil catfish 2 analyzer invented in 1986-103.
Figure 3, which is currently being filed as No. 593, shows the configuration of this automatic gas-in-oil analyzer as well as a system diagram for explaining the oil and gas routes. The operation will be explained with reference to FIG. 3 by dividing it into the sample oil collection process, dissolved gas extraction process, extraction gas mixing process, extraction gas injection process into the gas chromatograph, and system cleaning process.

1. Collection of sample oil into the extraction cylinder A piston 2 is disposed in the extraction cylinder 1 so as to be slidable in the axial direction by a piston rod 3 provided at the center thereof. A bellows 4 is attached to the lower part of the outer circumference of the piston 2 up to the bottom.
is provided between the bellows 4 and the extraction cylinder 1, and a first
A zero chamber 40 is formed. The piston 2 is provided with several small holes 6 that penetrate through the inside from the side surface thereof and reach the top surface. An O-ring 5 is provided between the side surface of the piston 2 above the opening of the pore 6 and the inner surface of the extraction cylinder 1.
is arranged, and a second chamber 41 is formed above the O-ring 5 in the inner chamber of the extraction cylinder 1.On the other hand, the flow path for the sample oil flowing into the extraction cylinder 1 and being discharged is the oil-filled passage. A first oil is supplied from a container 8 containing sample oil 7 collected from the equipment via a solenoid valve 9, a check valve 13, and a solenoid valve 10.
and a solenoid valve 11. which is connected to a piping line that communicates with the chamber 40 of the extraction cylinder 1 and a piping line that extends upward from the extraction cylinder 1.
Reverse valve 14. It consists of a route that is piped to the external free end of this system via the solenoid valve 12, and a pipe that connects these two routes.

Next, the procedure for collecting the sample oil 7 into the extraction cylinder 1 with the configuration up to this point will be explained. The piston 2 stops at the uppermost position in the extraction cylinder 1, the solenoid valves 9, 10, 11, and 12 are open, and the check valve 13 allows oil to flow only from the side of the container 8. 14, oil flows only from the extraction cylinder 1 side, so when the piston 2 is lowered to the lowest position with the piston rod 3 in this state, the extraction cylinder 1 and the piston 2
The sample oil 7 flows into the extraction cylinder IK through the solenoid valve 9° check valve 13 and the t-magnetic valve 11 in order to reduce the pressure in the second chamber 41 formed between the two. At this time, the oil existing in the first chamber 40 is pressurized by the downward movement of the piston 2 and is forced out through the solenoid valve 10, but the flow is blocked to the check valve 13 and the oil is removed from the container 8. It joins with the sample oil 7 flowing in, passes through the electromagnetic valve 11, and is collected into the second chamber 41.

Next, when the piston rod 3 is operated to raise the piston 2 to its maximum position, some of the oil that had accumulated in the second chamber 41 flows into the first chamber 40 through the pore 6 of the piston 2. Most of the oil is discharged to the outside through the solenoid valve 11, the check valve 14, and the solenoid valve 12. At the same time, the pressure in the first chamber 40 is reduced, and the sample oil 7 passes through the solenoid valve 9. The oil flows through the check valve 13 and the electromagnetic valve 10, but at this time, some of the oil discharged from the pipe connecting the two paths is mixed in.

When the above operation is repeated, for example, six times, the oil sampled in the extraction cylinder 1 is replaced with new sample oil 7. Finally, by stopping the piston 2 at the uppermost position, the oil accumulated in the 20th chamber 41 in the extraction cylinder 1 is discharged, and a certain amount of sample oil 7 is collected in the first chamber 40.

2. Extraction of dissolved gas in collected sample oil Extraction cylinder 1
An extraction gas path is provided outside the upper part of the extraction cylinder 1 so as to communicate with the extraction cylinder 1 in order to extract the gas in the sample oil 7 sampled and guide it to the analyzer. That is, the extracted gas is guided from the extraction cylinder 1 through the solenoid valve 15, through the oil detector 16, and into the extracted gas sampling cylinder 18. automatic hexagonal pulp 60.61
The gas flows into the metering tubes 60a, 61a attached to these and the extraction gas mixing cylinder 20. Hereinafter, the path from the solenoid valve 19 to the extraction gas mixing cylinder 20 will be collectively referred to as a metering valve system. Note that detailed description of the configuration and operation of the gas chromatograph 42 will be omitted.

The oil detector 16 is a beam switch consisting of a light emitting diode that emits light with a wavelength of 9400A and its light receiver.The piping in this part uses a glass tube that transmits light, and the oil is sent from the extraction cylinder 1. A signal is output when the oil rises inside the glass tube and blocks the light.

In response to this signal, the solenoid valve 15 is closed to prevent the oil from rising.Next, the procedure for extracting dissolved gas from the sample collected in the extraction cylinder 1 will be explained. When the piston 2, which is at the highest limit position, is lowered to the lowest position with the solenoid valves 9, 10, 11, 12 and 15 closed, the upper second chamber 41 in the extraction cylinder 1 becomes depressurized, and the lower part As the pressure in the first chamber 40 increases, the sample oil collected in the first chamber 40 passes through the pore 6 in the upper part of the piston 2 and is violently injected into the second chamber 41 in the extraction cylinder 1. At this time, since that area is in a vacuum state, the gas and oil dissolved in the sample oil 7 are separated. When the solenoid valves 15 and 17 are opened when the piston 2 reaches the lowest position and starts rising again, the gas separated and extracted from the sample oil 7 is guided through the oil detector 16 to the under-extracted gas sampling cylinder 18. At this time, the piston 18a of the extraction gas sampling cylinder 18 is lowered in advance to bring it into a reduced pressure state.

The extracted gas collected in the cylinder 18 closes the solenoid valve 17 and opens the solenoid valve 19 to raise the piston 18a.
Piston 20a of extraction gas mixing cylinder 20 in advance
By repeating these piston and valve operations about 30 to 40 times, the extracted gas sampled into the extracted gas sampling cylinder 18 is finally introduced into the metering valve system, which has been depressurized. Most of the gas collected in the sample oil 7 and dissolved in the sample oil 7 is extracted.

3. The gas extracted by operations beyond mixing the extracted gas in the metering valve system has different solubility depending on the gas component, and the composition differs before and after the extraction operation, so perform the following operations to make it uniform. .

Open the solenoid valves 17 and 19 and open the extraction gas mixing cylinder 2.
The piston 20a in 0 is lowered from the uppermost position to the lowermost position and stopped. Then, the pressure inside the mixing cylinder 20 is reduced and the extracted gas collected in the metering valve system flows into the mixing cylinder 20 while being stirred. Next, when the piston 18a in the extracted gas sampling cylinder 18 is similarly lowered from the uppermost position to the lowermost position and stopped, the extracted gas that had flowed into the mixing cylinder 20 is conversely moved into the reduced pressure in the sampling cylinder 18. It flows into the water while being stirred. Then the piston 18a t! in this sampling cylinder 18! - When the piston 20at in the mixing cylinder 20 is raised from the lowest position to the highest position, the extraction gas flows into the mixing cylinder 20, and in the same way, the piston 20at in the mixing cylinder 20 is raised from the lowest position to the highest position and then stopped. By repeating these series of piston operations, the extracted gas in the metering valve system is effectively stirred and mixed to have a uniform composition. Finally, when stopping the drive of the pistons 18a and 20a, set the pistons to the uppermost position. 60.
By switching the flow path 61 using an electric motor (not shown), the liquid is injected into the flow path of the gas chromatogram 742. This extracted gas is piped into the argon gas cylinder 50 and flows into the gas chromatograph 42.
A column and a detector (not shown) are carried and analyzed.

5. Part of the extracted gas sampled in the metering valve system as described above is injected into the gas chromatograph 42 and analyzed. However, at this time, the metering tube 60a.

The extracted gas collected in the metering valve system other than 61a remains in the piping and causes an error in the next analysis value. Therefore, cleaning is required to remove residual extraction gas in this system. This cleaning procedure is performed as follows. A solenoid valve 24 and a solenoid valve 1 are provided in the middle of the piping from the argon gas cylinder 50 connected to the path connecting the extraction cylinder l to the extraction gas sampling cylinder 18.
7, 19, and 21 are opened, the solenoid valve 15 is closed, and the argon gas is introduced from the cylinder 50 into the metering valve system for 30 seconds, and the remaining extraction gas is discharged from the system through the exhaust port 25. Next, close the solenoid valves 21 and 24, and move the piston 18a in the extraction gas sampling cylinder 18 and the piston 20 in the gas mixing cylinder 20 up and down several times alternately, without disconnecting each solenoid valve or connection. The remaining extraction gas is drawn out, so the solenoid valves 21 and 24 are opened again, argon gas is flowed from the cylinder 50 for 30 seconds, and the extracted extraction gas is discharged out of the system. By repeating this series of operations several times, the residual extraction gas is discharged outside the system and the inside of the system is cleaned.

This IJ-=ing process is normally performed twice in one analysis process, during the collection of the sample oil 7 into the extraction cylinder 1 and during the analysis of the extracted gas. 0 As described above, when analyzing gas in oil using this device, the piston 2 in the extraction cylinder 1 is used to extract as much gas as possible dissolved in the sample oil 7. From 30 to 30, the gas in the oil is extracted by driving it up and down to reduce the pressure in the second chamber 41, and collect it in the reduced pressure metering valve system.
However, as a result of further detailed experiments by the present inventors regarding this method of extracting gas in oil, it was found that even if the above-mentioned extraction operation was repeated approximately 30 to 40 times. It was found that the extraction efficiency of gas in oil was slightly better than the conventional Torricelli method using mercury, but it was still not sufficient.

Therefore, it is desirable to have an automatic gas-in-oil analyzer that can extract gas dissolved in oil efficiently and sufficiently, and which can provide highly reliable analytical values.

[Purpose of the invention]

The present invention has been made in view of the above points, and its purpose is to provide an automatic gas-in-oil system capable of sufficiently extracting gas dissolved in oil and analyzing the extracted gas-in-oil with high precision. It says that it will provide analysis equipment.

[Key points of the invention]

The automatic gas-in-oil analyzer of the present invention has a vacuum pump added to the metering valve system of the conventional automatic gas-in-oil analyzer to further reduce the pressure inside the metering valve system, and this makes it possible to further reduce the pressure inside the metering valve system. The extraction efficiency of extracted gas is improved compared to conventional equipment,
This allows for highly accurate gas analysis in oil.

[Embodiments of the invention]

The present invention will be explained below based on examples.

FIG. 1 is a system diagram of an automatic gas-in-oil analyzer according to the present invention, and the same reference numerals are used for parts common to those in FIG. 3, and the functions of each component common to those in FIG. Since they are the same, their explanation will be omitted.

The difference between FIG. 1 and FIG. 3 is that a three-way solenoid valve 22 is added to the outlet side of the solenoid valve 21 that shuts off the metering valve system and the outlet 25 in FIG. 3, and a vacuum pump 23 is added to the path that connects it. The difference between the present invention and the conventional one is the extraction cylinder 1.
Dissolved in sample oil 7 collected in 1. It is in the process of extracting the gas that is

This extraction process will be explained below with reference to FIG.

After collecting the sample oil 7 into the extraction cylinder 1, the solenoid valve 19
．． 21 is opened, and the flow path of the three-way solenoid valve 22 is made into a flow path that connects the solenoid valve 21 to the vacuum pump 23. Next, the vacuum pump 23 is operated to create a negative pressure in the piping from the solenoid valve 17 to the solenoid valve 21. After that, solenoid valve 19.21
After closing the three-way solenoid valve 22 and switching the flow path of the three-way solenoid valve 22 from the solenoid valve 21 to the discharge port 25, the vacuum pump 23 is stopped. The following extraction operation is similar to that of the conventional apparatus described above.

That is, when the piston 2 at the uppermost position in the extraction cylinder 1 is lowered to the lowermost position with the solenoid valves 9, 10, 11, 12 and 15 closed, the upper second chamber in the extraction cylinder l 41 is the first chamber 4 at the bottom with reduced pressure.
As the pressure increases, the sample oil 7 collected in the first chamber 40 is violently injected into the 20th chamber 41 in the extraction cylinder 1 through the pore 6 at the top of the piston 2, and at this time, the area Since the sample oil 7 is in a vacuum state, the gas and oil dissolved in the sample oil 7 are separated. When the solenoid valves 15 and 17 are opened when the piston 2 reaches the lowest position and starts to rise again, the gas separated and extracted from the sample oil 7 is guided through the oil detector 16 to the extracted gas sampling cylinder 18. At this time, the piston 18a of the extracted gas sampling cylinder 18 is lowered to be in a reduced pressure state in advance. When the solenoid valve 17 is closed and the solenoid valve 19 is opened to raise the piston 18a, the extracted gas collected in the cylinder 18 has already been released into the piston 20a.
It is introduced into the metering valve system where the pressure is reduced by lowering the pressure. By repeating these piston and valve operations about 30 to 40 times, the extracted gas collected in the extracted gas sampling cylinder 18 is finally collected in the metering valve system, and the gas dissolved in the sample oil 7 is collected. The majority of is extracted.

FIG. 2 is a graph showing the relationship between the extraction rate of carbon dioxide gas in air-saturated oil and the number of times of extraction, comparing the conventional apparatus and the apparatus of the present invention. In Fig. 2, curve A shows the relationship when gas is extracted using the conventional method, and curve A shows the relationship when gas is extracted by trapping negative pressure in the metering valve system using the vacuum pump 23 according to the present invention. There is. The extraction rate is 1 for Tepra method.
This is the value when it is set to 00.

Comparing the two curves A and 2 in Figure 2, we can see that with the conventional device, the carbon dioxide extraction rate is 76% even when the number of extractions is 40, whereas with the device of the present invention, the carbon dioxide extraction rate is 76% even when the number of extractions is 40. The gas extraction rate is 86%, which is about 10% higher with the device of the present invention.
It can be seen that the extraction rate has improved.

This is due to the effect that the device of the present invention makes the inside of the metering valve system more depressurized, and the gas dissolved in the sample oil 7 can be extracted efficiently, and the gas dissolved in the sample oil 7 can be efficiently extracted. ◇ [Effect of the invention] Extraction cylinder, extracted gas sampling cylinder, mixing cylinder,
Using an automatic gas-in-oil analyzer, which consists of a six-way automatic valve between the extracted gas sampling cylinder and the mixing cylinder, and the necessary piping and solenoid valves, the gas extracted from the sample oil is made to have a uniform composition. Conventionally, gases with high solubility could not be extracted satisfactorily during the process of extracting dissolved gas from sample oil when mixing and injecting into a gas chromatograph. By adding a pump and increasing the degree of pressure reduction in the metering valve system, the extraction rate for carbon dioxide gas in air-saturated oil is 76 times higher than the conventional one, even after 40 extractions, as described in the example.
In other words, according to the present invention, an analytical value close to the true concentration of gas in oil can be obtained, and the reliability of the analytical value has been greatly improved. 0 that could be used as a device

[Brief explanation of drawings]

Figure 1 is a system diagram of the automatic gas-in-oil analyzer of the present invention;
The figure is a diagram showing the relationship between the extraction rate of carbon dioxide gas in air-saturated oil and the number of extractions, and FIG. 3 is a system diagram of a conventional automatic gas-in-oil analyzer. 1...Extraction cylinder, 18...Extraction gas sampling cylinder IJyda+ 18a, 20a...
Piston, 20...Mixing cylinder, 22...
...Three-way solenoid valve, 23...Vacuum pump 7', 6
0.61... Automatic hexagonal pulp, 60a, 6
1a...Figure 2

Claims (1)

[Scope of Claims] 1) A device that automatically analyzes gas in oil by collecting sample oil, extracting dissolved gas in the sample oil, stirring and mixing, and then injecting the extracted gas into a gas chromatograph. , an extraction cylinder that collects sample oil by operating a piston equipped with a bellows and then extracts dissolved gas in the sample oil; and an extraction cylinder that is piped to the extraction cylinder and temporarily stores the extraction gas and then injects it by operating the piston. A sampling cylinder, a mixing cylinder that uniformly stirs the composition of the extracted gas sent from the extracted gas sampling cylinder by piston operation, and a pipe installed between the extracted gas sampling cylinder and the gas mixing cylinder, and injects the extracted gas into the gas chromatograph. It is characterized by being equipped with a six-way automatic pulp equipped with a metering tube, and a vacuum pump that is connected to the gas mixing cylinder through a three-way solenoid valve and creates negative pressure in the piping between the extracted gas sampling cylinder and the gas mixing cylinder. Automatic gas-in-oil analyzer.