JPH0358457B2 - - 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 intervention is 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
A path is piped to communicate with the first chamber 32 via the solenoid valve 11 and the check valve 12 from the second chamber 33 to an oil outlet at the free end of the system. 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, goes to the filter 16, and is further led to the extracted gas sampling cylinder 17.
Solenoid valves 1 are 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. This 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. put. 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 accuracy.

[Key points of the invention]

The present invention separates the oil from the gas in the oil by installing a solenoid valve near the top of the bleed cylinder and a selective check valve above the solenoid valve that allows only the extracted gas extracted from the sample oil to pass through. This makes it possible to carry out stable gas analysis.

[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 to the analyzer system. In addition, a selective check valve 14a is used in place of the oil detector 14 in the piping to the analyzer system near the upper part of the bleed cylinder 1, and the mutual positional relationship with the solenoid valve 15 is adjusted to be closer to the bleed cylinder 1. is a solenoid valve 15, and a selective check valve 14a is connected to this solenoid valve 15.

Next, the conventional oil detector 14 and the selective check valve 14a used in the device of the present invention will be explained in detail.

FIG. 3 is a block diagram of the main parts of the oil detector 14, and FIGS. 4 and 5 are cross-sectional views of the main parts of the selective check valve.

Transparent pipe 23 connected to the piping system in Fig. 3
The light emitting part 24 is on one side and the light emitting part 24 is on the other side.
A light receiving section 25 is arranged to receive light emitted from the light receiving section 25. 26 represents these power supply units. transparent tube 23
When there is no oil, the light receiving section 25 receives the light from the light emitting section 24 and generates an electrical output, which causes the solenoid valve 15 shown in FIG. 1 or 2 connected to this detector to open. However, when the oil rises and reaches the transparent tube 23, the light emitted from the light emitting section 24 is blocked by the oil and does not reach the light receiving section 25, so that sufficient output cannot be generated. The solenoid valve 15 is closed, and the solenoid valve 1 is closed depending on the presence or absence of oil in the transparent tube 23 in the oil detector 14.
The opening and closing operations of step 5 are automated, and the oil and extracted gas are separated.

On the other hand, in the selective check valve 14a, as shown in FIG.
is included. The oil rising from below flows into the hollow body 27 and continues to rise while keeping the float 29 afloat, but when the float 29 reaches the point where the diameter becomes narrow at the top of the hollow body 27, it does not rise any further. Therefore, oil is also prevented from advancing here. In the absence of oil, the float 29 rests on the perforated plate 28, but since the size of the float 29 is appropriately smaller than the perforated plate 28, the extracted gas can pass through the sides of the float 29. . FIG. 5 shows a selective check valve having a different shape from that in FIG. 4. For example, the float 29 may be shaped like a rocket as shown in FIG.
Note that the arrows in FIGS. 3 to 5 indicate the traveling direction of the oil and extracted gas.

The mutual positional relationship between the oil stopper, which prevents oil from penetrating into the analyzer, and allows only the extracted gas to pass through, and the solenoid valve, which is opened and closed by this stopper, is similar to that of the conventional device shown in Figure 1. It is also possible to arrange it in the opposite way. That is, it is also effective to arrange the solenoid valve 15 closer to the bleed cylinder 1 and connect the oil detector 14 above it. In other words, even if the oil detector 14 is used, the connection with the solenoid valve 15 is
By arranging the piston 2 in the opposite direction to that shown in the figure, 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. 1, but the solenoid valve 15 is located in front of the oil detector 14. Even when the piston 2 reaches the uppermost position in the bleed cylinder 1, no pressure is applied to the oil detector 14, and therefore the creep of oil entering the transparent tube 23 of the oil detector 14 does not proceed; Improved separation of sample oil and extracted gas,
Since oil is present between the oil detector 14 and the solenoid valve 15 at the time of starting gas analysis, all extracted gas is collected from the path above the oil detector 14, so it should be analyzed. There is an advantage that the total amount of bleed gas can be ensured without leaving any excess, and the accuracy of analysis can be improved.

However, in the present invention, taking into account the advantages of arranging the oil detector 14 and the solenoid valve 15 in reverse,
This idea is further developed by using a selective check valve 14a instead of the oil detector 14.

When the oil detector 14 shown in the configuration diagram in FIG. 3 is used, when air bubbles generated with rising oil reach the optical system part through the transparent tube 23, the light emitted from the light emitting part 24 is blocked by the air bubbles. light receiving section 25
Since the solenoid valve 15 is closed and the extracted gas is not produced in the bleed cylinder 1, the solenoid valve 15 is closed.
left inside. Therefore, the entire amount of extracted gas cannot be collected unless the operation of the piston 2 of the extraction cylinder 1 is repeated at least 20 times. On the other hand, according to the present invention, the oil detector 14 is replaced by a selective check valve 1 as shown in FIGS. 4 and 5, for example.
4a, bubbles in the rising oil are destroyed by the perforated plate 28, allowing only the extracted gas to pass through. Therefore, the amount of extracted gas remaining in the bleed cylinder 1 is reduced, and the piston 2 can be operated approximately half as many times as in the case of the oil detector 14, resulting in extremely high efficiency. In addition, since the oil detector shown in Fig. 3 uses light transmission, there is a concern that oil may adhere to the inner wall of the transparent tube in the piping path and cause malfunction. The selective check valve used does not require such concerns at all. Additionally, selective check valves are more economical, with equipment costs being about 1/5th that of oil detectors. However, since this selective check valve itself cannot open or close the solenoid valve, the solenoid valve 15 is closed in FIG. 2 when the piston 2 reaches its upper limit position. .

In addition to the above, in the conventional device shown in FIG. During the circulation process, the gas present in the bleed cylinder 1 remains in the second chamber 33,
These gases can get mixed in during the deaeration process of the sample oil and cause errors in the analysis of the extracted gas.
In the device of the present invention, as shown in FIG. 2, the paths of the solenoid valve 11 and the check valve 12 are arranged higher than the uppermost position of the piston 2, so the gas existing in the bleed cylinder 1 is absorbed during the oil circulation process. Since all of the gas is exhausted, there is no possibility of an error in the analysis of the extracted gas.

〔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 circulation path of the oil from which sample oil is collected is connected to the piston of the extraction cylinder. By placing the solenoid valve necessary for the sample oil degassing process near the bleed cylinder and connecting the selective check valve above it,
It brings about the following advantages.

(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 selective check valve will not creep any further.

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

(4) The degassing process is performed efficiently without malfunction.

As a result of the above, when analyzing the extracted gas of a sample oil using the apparatus of the present invention, the entire amount of gas dissolved in the oil can be collected efficiently and separated from the oil in a short time during the degassing process. Since there is no outside air mixed in and oil does not reach the analyzer system, the analyzer is always kept in the best condition and gas analysis can be performed in a stable state, which is a huge improvement in analysis accuracy. Effects can be obtained.

[Brief explanation of drawings]

FIG. 1 is a system diagram of the main parts for explaining a conventional automatic gas-in-oil analyzer, FIG. 2 is a system diagram of the main parts of the apparatus of the present invention, FIG. 3 is a configuration diagram of an oil detector, and FIG. FIG. 5 is a sectional view of the selective check valve. 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, 14a ... Selective check valve, 17 ... Bleed gas sampling cylinder, 27
...Hollow body, 28 ... Perforated plate, 29 ... Float, 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 which 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. a solenoid valve and a sample oil that are connected by piping in order from the cylinder side above the position where the exhaust path is connected to the cylinder near the top of the cylinder in the path leading from the second chamber to the extracted gas sampling section; An automatic gas-in-oil analyzer characterized by comprising a selective check valve that allows only the extracted gas extracted from the oil to pass through.