JPH0358456B2 - - Google Patents

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 gas concentration in the oil increases, so the gas dissolved in the oil (hereinafter referred to as gas in oil) is extracted and analyzed, and based on the analysis results, the inside of the transformer can be detected. A method for diagnosing abnormal conditions is already well known, and because abnormal conditions can be detected early, it is widely used and effective both in Japan and abroad.

Methods for analyzing gas in oil include, for example: (1) Extracting gas in oil using a Torrichieri vacuum using mercury, and analyzing the extracted gas using a gas chromatograph.

(2) Gas in the oil is extracted using a combination of a mercury diffusion pump and a Tepra pump, and the extracted gas is analyzed using a gas chromatograph.

etc., and are widely used.

However, while these methods are easy to implement, they also have the following problems.

(1) Operations are performed manually or semi-automatically, so human hands are required throughout the entire process from start to finish.

(2) Operation is complicated, and operator skill is required to perform highly accurate analysis.

(3) Since mercury is used, there is a risk of harm to the human body due to deterioration of the working environment due to mercury volatilization.

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

In order to solve the above problems, an automatic analyzer for gas in oil, invented by the present inventors, was developed
It is described in Publication No. 209, the magazine "Fuji Jiho" Vol. 45, No. 11, and the "Journal of Japan Petroleum Institute" Vol. 24, No. 2.

Figure 1 shows the configuration of this automatic gas-in-oil analyzer as well as a system diagram for explaining the paths of oil and gas. The explanation will be divided into the sample oil collection process and the deaeration process.

1 Collection of sample oil into the bleed cylinder A piston 2 is arranged in the bleed cylinder 1 so as to be slidable in the axial direction by a piston rod 3 provided at the center of the piston 2. Bearing 3 fixed with member 34
5 and passes through the member 34. A bellows 4 is attached to the lower part of the outer circumference of the piston 2 up to the bottom.
A first chamber 32 is formed between the bellows 4 and the bleed cylinder 1. 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 disposed between a portion of the side surface of the piston 2 above the opening of the pore 6 and the inner surface of the bleed cylinder 1, and a second A chamber 33 is formed.

On the other hand, the flow path for the sample oil flowing into and being discharged from the bleed cylinder 1 is piped between the bleed cylinder 1 and a container 8 containing the sample oil 7 collected from the oil-filled equipment. 9, Solenoid valve 10
and a piping route from the second chamber 33 to the oil outlet at the free end of the system via the solenoid valve 11 and the check valve 12. and a path connecting these two paths via a solenoid valve 13.

Next, the procedure for collecting the sample oil 7 into the bleed cylinder 1 with the configuration up to this point will be explained. The piston 2 stops at the uppermost position in the bleed cylinder 1, the solenoid valves 10, 11, and 13 are open, and the oil flows only from the container 8 side to the check valve 9.
2, oil flows only from the bleed cylinder 1 side, so when the piston 2 is lowered to the lowest position by the piston rod 3 in this state, the second chamber 33 formed between the bleed cylinder 1 and the piston 2 Sample oil 7 flows into bleed cylinder 1 through check valve 9 and solenoid valves 13 and 11 to be depressurized. At this time, the oil existing in the first chamber 32 is pressurized by the downward movement of the piston 2, and the oil that is present in the first chamber 32 is pressurized to the solenoid valve 1.
0, but the flow is blocked toward the check valve 9, and it joins with the sample oil 7 flowing from the container 8 and is collected into the second chamber 33 through the electromagnetic valves 13 and 11. Ru.

Next, when the piston rod 3 is operated to raise the piston 2 to the upper limit position, a portion of the oil accumulated in the second chamber 33 flows into the first chamber 32 through the pore 6 of the piston 2. However, most of the solenoid valve 1
1. It passes through the check valve 12 and is discharged to the outside via the oil discharge port. At the same time, the first chamber 32 is depressurized and the sample oil 7 flows therein through the check valve 9 and the solenoid valve 10. At this time, the solenoid valve 13 remains open, so that the solenoid is removed from the top of the bleed cylinder 1. Some of the oil discharged through valve 11 is mixed in. However, the solenoid valve 13 may be closed when the piston 2 is raised.

When the above operation is repeated, for example, six times, the oil sampled in the bleed cylinder 1 is replaced with new sample oil 7. Finally, by stopping the piston 2 at the upper limit position, the oil accumulated in the second chamber 33 in the bleed cylinder 1 is discharged, and a certain amount of sample oil 7 is collected in the first chamber 32.

2. Degassing the collected sample oil In order to extract the gas in the sample oil 7 collected in the bleed cylinder 1 and guide it to the analyzer, an extraction gas path is provided outside the top of the bleed cylinder 1 so as to communicate with the bleed cylinder 1. It is provided. That is,
The extracted gas passes from the bleed cylinder 1, passes through the oil detector 14, passes through the electromagnetic valve 15, passes through the filter 16, and is further led to the extracted gas sampling cylinder 17.
A solenoid valve 1 is provided before and after this cylinder 17, respectively.
8 and 19, and a gas flow path is provided so that the extracted gas further flows into an extracted gas storage cylinder 20 and is guided to a gas chromatograph (not shown) via a solenoid valve 21.

Next, a procedure for sending the gas degassed from the sample collected in the bleed cylinder 1 to the gas chromatograph will be explained. When the piston 2 at the highest limit position is lowered to the lowest position by closing the solenoid valves 10, 11, 13 and 15, the upper second chamber 33 in the bleed cylinder 1 becomes depressurized, and the lower first chamber
As the pressure in the first chamber 32 increases, the pressure in the first chamber 32 increases.
The sample oil collected in the hole 6 at the top of the piston 2
The sample oil is violently injected into the second chamber 33 in the bleed cylinder 1, and since the area is under vacuum at this time, the gas dissolved in the sample oil is separated from the oil. When the piston 2 reaches the lowest position and starts rising again, the solenoid valve 15 is opened, and the gas separated and extracted from the sample oil flows through the solenoid valve 1.
The extracted gas is introduced from the filter 16 disposed on the upper part of the extractor 5 into an extracted gas sampling section comprised of an extracted gas storage cylinder 20. The separated and extracted gas passes through the filter 16 and is guided to the extracted gas sampling cylinder 17, but at this time, the solenoid valve 18 is opened in advance and the electromagnetic valve 19 is closed, so that the extracted gas sampling cylinder 17 is brought into a reduced pressure state by lowering the piston 17a. . When the solenoid valve 18 is closed and the solenoid valve 19 is opened to raise the piston 17a, the extracted gas collected in the collection cylinder 17 enters the extracted gas storage cylinder 20, which has been previously depressurized by lowering the piston 20a. By repeating these piston and valve operations about 20 times, the extracted gas sent to the extracted gas sampling cylinder 17 is successively collected in the extracted gas storage cylinder 20, and almost all of the gas dissolved in the sample oil 7 is collected. Since the extracted gas is extracted, the solenoid valve 21 connected to the extracted gas storage cylinder 20 is opened and the extracted gas is guided to a gas chromatograph (not shown) for gas analysis. Note that there is a gas flow path that branches off between the solenoid valve 15 and the filter 16 and has a solenoid valve 22, and is connected to an external argon gas source (not shown).Using this path, After the analysis is completed, argon gas is introduced under positive pressure, and oil and the like remaining in the piping of this apparatus system can be discharged through the check valve 12.

However, during the above process, the injected sample oil returns to its original state through the pore 6, but not all of it returns, and some of it gradually rises through the solenoid valve 15, which remains open, and advances to the extraction gas sampling cylinder 17. I end up. For this reason, conventionally, the oil level is detected by an oil detector 14 installed above the extraction cylinder 1, and based on the signal, the solenoid valve 15 installed above the oil detector 14 is closed, and the oil flows into the extraction gas sampling cylinder 17. This prevented contamination.

However, subsequent research conducted by the present inventors revealed that even the provision of the oil detector as described above was still not sufficient, and that the present device had the following drawbacks.

1) When this apparatus is used for a long period of time, the oil remaining inside the piping gradually creeps and reaches the extracted gas sampling cylinder 17 and the gas flow path system of the analyzer, reducing the analytical performance of the apparatus.

2) A small amount of the extracted gas from the previous analysis remains between the oil detector 14 and the solenoid valve 15, so this will not be a problem if the oil analyzed last time has little gas in the oil, but if there is a lot of gas in the oil, the analysis will fail. adversely affect the value.

[Purpose of the invention]

An object of the present invention is to provide an automatic gas-in-oil analyzer that can completely separate sample oil and gas extracted from the sample oil and analyze gas-in-oil with high precision.

[Key points of the invention]

The present invention provides a solenoid valve near the top of the bleed cylinder and an oil detector above the solenoid valve to improve the separation of oil and gas in the oil and enable stable gas analysis. It is.

[Embodiments of the invention]

Figure 2 shows a system diagram of the main parts of the automatic gas-in-oil analyzer according to the present invention. Parts common to those in Figure 1 are given the same reference numerals, and the functions of each component are explained in principle. Since it is the same as FIG. 1, the explanation will be omitted.

The difference between Fig. 2 and Fig. 1 is that the paths of the solenoid valve 11 and check valve 12 are not directly connected to the bleed cylinder 1, but are connected to piping extending upward from the bleed cylinder 1, and that The positional relationship between the detector 14 and the solenoid valve 15 is reversed. That is, in the device of the present invention, the bleed cylinder 1
Solenoid valve 15 near the top, oil detector 1 above it
4 is arranged, and piping leading to the solenoid valve 11 and check valve 12 is provided in the middle of the piping between the solenoid valve 15 and the bleed cylinder 1.

Therefore, in the conventional device shown in FIG.
Since the path of the check valve 12 is located below the uppermost position of the piston 2, the gas present in the bleed cylinder 1 remains in the second chamber 33 during the oil circulation process during sample oil collection. However, these gases may get mixed in during the deaeration process of the sample oil, causing errors in the analysis of the extracted gas.In contrast, in the apparatus of the present invention, the solenoid valve 11 and check valve 12 are Since the path is located higher than the uppermost position of the piston 2, there is no possibility that the gas present in the bleed cylinder 1 will cause an error in the analysis of the extracted gas completely discharged during the oil circulation process.

On the other hand, in the degassing process of the conventional device shown in FIG. 1, before the piston rod 2 reaches the upper limit position, oil enters the detector 14 together with the bleed gas, and the oil level is detected here and the solenoid valve 15 is closed. However, as the piston 2 continues to rise to the maximum position, pressure is applied to the oil detector 14, and as a result, the oil rises even though the solenoid valve 15 is closed, causing the piston 2 to reach the maximum position. When oil stops rising. After that, when the piston 2 descends to the lowest position, the pressure in the space inside the bleed cylinder 1, that is, the second chamber 33, is reduced and the oil in the oil detector 14 is returned there, and the solenoid valve 15 is also opened, and the piston 2 is moved again. begins to rise. By repeating this vertical movement of the piston 2 about 20 times, the gas in the oil will be extracted.

The oil that has risen between the oil detector 14 and the solenoid valve 15 in the above degassing process is returned to the second chamber 33 each time, but once the oil rises, only a small amount of oil adheres to the inner wall of the pipe. However, it remains attached. Also, the rising position of the oil varies; when there is a lot of gas in the oil, it will be at a low position, but when there is little gas in the oil, it will be at a high position. Therefore, depending on the sample oil, the oil may rise close to the electromagnetic valve 15, resulting in oil adhering to the inner wall. When various sample oils with different amounts of gas in the oil are analyzed repeatedly using this analyzer, the oil adhering to the inner wall will gradually be exposed to the solenoid valve 15.
It creeps towards , and finally the solenoid valve 15
The sample reaches the sampling cylinder 17. If this happens, normal analysis will no longer be possible, and the inside must be cleaned. In particular, when the oil creeps into the solenoid valve 15, the complicated structure inside the solenoid valve makes it difficult for the oil to return to the second chamber 33, and as a result, the oil creeps up to the sampling cylinder 17. This causes the arrival time to be shortened.

On the other hand, in the device of the present invention shown in FIG. 2, the operation of the piston 2 and the action of the solenoid valve 15 by the oil detector 14 are both the same as in the case of FIG.
5 is located in front of the oil detector 14, so when the oil level is detected by the oil detector 14 and the solenoid valve 15 is closed, the oil level will not rise even if the piston 2 continues to rise to the maximum limit. , it can always be stopped at a certain height. In addition, since there is no solenoid valve or other complicated structure above the oil detector 14, the oil that rises to the oil detector 14 each time during the degassing process easily flows smoothly toward the second chamber 33. It's coming back.
At this time, oil remains in the solenoid valve 15 as well, but since the oil is attached to the inner wall of the pipe between the oil detector 14 and the solenoid valve 15, there is no creep force from the solenoid valve 15.
No creep occurs. Also, although there is some creep of oil remaining on the inner wall of the oil detector 14, it takes a long time for the oil to creep on the upper wall surface of the oil detector 14, and it takes an extremely long time for the oil to reach the sampling cylinder 17, so there is no problem in practical use. . As a result, the troubles caused by oil creep that occur in conventional equipment are almost eliminated, and the sample oil and extracted gas are almost completely separated.

Also, as shown in Fig. 1, an oil detector 14 and a solenoid valve 15
In the conventional arrangement, extracted gas is left in the piping area connecting these two at the start of gas-in-oil analysis, and the amount of extracted gas to be analyzed is located above the solenoid valve 15. Therefore, it is not possible to accurately obtain the total amount of extracted gas. However, in the apparatus of the present invention shown in FIG. 2, the oil detector 14 and the solenoid valve 15 are arranged in a position opposite to that in FIG. Oil is present in the piping, and all extracted gas is in the path above the oil detector 14.
The total amount of extracted gas to be analyzed is secured, and the accuracy of analysis can be improved.

〔Effect of the invention〕

As explained above in the embodiments, in an apparatus for extracting and analyzing gas in oil such as insulating oil of a transformer, according to the present invention, a part of the oil circulation path from which sample oil is collected is connected to the bleed cylinder. By installing the piston at a position higher than the upper limit of the piston and by connecting the solenoid valve and the oil detector in the reverse position during the sample oil degassing process, the following advantages are achieved.

(1) Outside air that gets mixed in when replacing the sample oil container does not accumulate in the upper part of the bleed cylinder, and is completely removed during the oil circulation process.

(2) Oil flowing into the oil detector will not creep any further.

(3) Extracted gas can be completely extracted for analysis and an accurate amount can be obtained.

As a result of the above, when analyzing the extracted gas of sample oil using the apparatus of the present invention, all the gas dissolved in the oil is reliably separated from the oil and collected, and there is no contamination of outside air, and the analysis apparatus is As a result, the analyzer is kept in the best possible condition and gas analysis can be performed in a stable state at all times, with the great effect of improving analysis accuracy.

[Brief explanation of drawings]

FIG. 1 is a system diagram for explaining a conventional gas-in-oil automatic analyzer, and FIG. 2 is a system diagram for explaining the apparatus of the present invention. 1... Bleed cylinder, 2... Piston, 4...
Bellows, 6... Pore, 9, 12... Check valve, 1
0, 11, 13, 15, 18, 19, 21, 22
... Solenoid valve, 14 ... Oil detector, 17 ... Bleed gas sampling cylinder, 32 ... First chamber, 33 ... Second chamber.

Claims (1)

[Claims] 1 A cylinder, a piston rod passing through the cylinder, a piston that engages with the cylinder and follows the piston rod, and is arranged concentrically with the piston rod, with one end attached to the piston and the other end attached to the piston. a bellows attached to the end of the cylinder through which the piston rod passes; the piston includes a first chamber formed between the bellows and the cylinder; and a first chamber formed between the bellows and the cylinder; A plurality of relatively small-diameter oil spout holes are formed that communicate with a second chamber formed on the opposite side, and the first chamber has a second chamber connected to a sample oil outlet housed in an external container.
The chamber is configured to communicate with the oil discharge port and the extracted gas sampling section through valves, respectively, and the chamber is connected between the external container and the cylinder via a check valve and a solenoid valve. Oil circulation formed by connecting a passage communicating with the first chamber and an oil discharge passage from the second chamber disposed ahead of the top dead center of the piston via a solenoid valve and a check valve. and an electromagnetic valve and oil detection connected by piping in order from the cylinder side above the position where the exhaust passage is connected to the cylinder in the vicinity above the cylinder in the passage leading from the second chamber to the extracted gas sampling section. An automatic gas-in-oil analyzer characterized by comprising: