JP3203608B2 - Gas-in-oil analyzer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an analyzer for analyzing gas components mixed in insulating oil of oil-filled electrical equipment, and more particularly to an analyzer suitable for diagnosing deterioration of an oil-filled transformer. It is.

[0002]

2. Description of the Related Art The first prior art for analyzing gas mixed in oil is discussed in a technical report of the Institute of Electrical Engineers of Japan (IEE (2) part No. 344). That is, the prior art involves extracting insulating oil from oil-filled electrical equipment and then extracting various gases from the insulating oil (tricelli method,
Dissolved gas in oil is extracted by Tepler pump method, etc., and the dissolved gas in oil is passed through a gas separation device in a gas chromatograph to separate the mixed gas into single component gas for analysis. Have been. A second prior art is disclosed in Japanese Patent Application Laid-Open No. 54-126591. That is, the second conventional technique extracts a gas mixed in the insulating oil by blowing the gas, and detects the combustible gas contained in the extracted gas as a mixed component. . Further, as a third conventional technique, there is a technique shown in FIGS. That is, in the prior art shown in FIGS. 4 and 5, a gas sampling bin 2 containing insulating oil 1 is closed with a bubbling head 3, and gas is extracted by sending air to the oil sampling bin 2 with a blower pump 11. The gas is sent out to the calibration tube 4 via the flow path switching valve 13. When the flow path switching valve 13 is switched, moisture is removed in advance by the water vapor removal filter 10, and air as carrier air is sent into the calibration pipe 4 through the flow path switching valve 13, thereby causing the inside of the calibration pipe 4 to be removed. The gas passes through the carbon dioxide detector 7 through a predetermined passage of the flow path switching valve 13. At that time, carbon dioxide is detected by passing through the carbon dioxide detector 7, and a part of the gas that has passed through the detector 7 is separated into individual component gases by passing through the gas separation device 5, Only the flammable gas is detected by the separated gas passing through the flammable gas detector 8, and thereafter, the arithmetic unit 9 is operated based on the separated gas and the remaining gas passing through the carbon dioxide detector 7.
The arithmetic processing is performed to analyze various gases for each single component. FIG. 5 shows output waveforms of the carbon dioxide detector 7 and the combustible gas detector 8. 6 and 7, the gas in the calibration tube 4 passes through the carbon dioxide detector 7 via the directional control valve 13, and then carbon monoxide is detected by the carbon monoxide detector 6. After detection, the combustible gas is detected by passing through the combustible gas detector 8 via the pump 11 ′, and the detected gas is analyzed by the arithmetic unit 9. FIG. 7 shows output waveforms of the carbon dioxide detector 7, the carbon monoxide detector 6, and the combustible gas detector 8, respectively.

[0003]

However, the prior art shown above does not consider the following points. That is,
In the first prior art, the dissolved gas is extracted from the insulating oil by various gas extraction methods, and the extracted gas is separated into a single component gas, so that the gas extraction device and the separation device are separate devices. Therefore, there is a problem that not only the operation of each device is complicated, but also it takes too much time to finally analyze. In addition, such devices that take too much time are unsuitable for actual work, because if the number of oil-filled electrical devices subject to analysis and survey is large, the number of surveys within a certain period of time will be limited. It is the present situation. The second prior art does not detect the gas for each single component gas, but detects the gas in a state in which only the flammable gas is mixed. There is an inadequate problem in diagnosing deterioration of a vessel. In the third prior art, a gas extraction unit including an oil sampling bottle 2, a calibration tube 4, and a pump 11 is analyzed by detecting a corresponding type of gas from the extracted gas, and a carbon dioxide detector 7, Separation device 5 or carbon monoxide detector 6,
Since the pump 11 ', the flammable gas detector 8, and the analysis unit composed of an arithmetic unit are integrally formed, gas extraction and analysis can be performed by merely installing the extracted insulating oil in the extraction unit. Although it is possible and it does not take much time as compared with the first conventional technique, it is difficult to further reduce the time. That is, the third prior art, for example, after analyzing the insulating oil from the first oil-immersed transformer to be analyzed, and then trying to analyze the insulating oil from the next oil-immersed transformer, Before that, in both the one shown in FIG. 4 and the one shown in FIG. 6, between the extraction unit and the analysis unit, it is necessary to completely remove the gas which was analyzed last time. They need to be cleaned, which has the disadvantage of being cumbersome. As a result, when the number of oil-filled electrical devices is large,
Although the number of processing units is larger than that of the first prior art, there is a problem that good processing efficiency cannot be obtained within a certain time.

An object of the present invention is to provide a practical and highly reliable gas-in-oil gas analyzer which can greatly improve the efficiency of analysis and improve the accuracy of analysis in view of the above-mentioned problems of the prior art. Is to do.

[0005]

In the apparatus for analyzing gas in oil according to the present invention, an extraction unit having a degassing unit for extracting dissolved gas from insulating oil in an oil collecting bin and a calibration tube for taking in the extracted gas in the degassing unit is provided. Mechanism, a separation unit that separates the extracted gas from the calibration tube for each single component, and a respective detector that detects the gas for each single component separated by the separation unit by type,
A calculation unit for analyzing the concentration of gas for each single component based on the detection of each detector, wherein the extraction mechanism evacuates the calibration tube and the degassing unit, and adjusts the pressure in the degassing unit. Vacuum means is provided to extract the dissolved gas in the insulating oil into the degassing section by the difference between the pressure in the oil sampling bottle and the pressure in the degassing section and the pressure in the calibration pipe. are doing.

[0006]

According to the present invention, as described above, the gas is evacuated between the calibration tube and the deaeration unit by the vacuum means, and the dissolved gas is introduced into the deaeration unit by utilizing the pressure difference between the deaeration unit and the oil collecting bin of the extraction mechanism. Since the extracted gas is sent to the calibration tube by utilizing the pressure difference between the degassing section and the calibration tube, the dissolved gas can be quickly extracted from the insulating oil. Also, since the extraction gas from the degassing section is sent to the evacuated calibration tube, there is no possibility that the extraction gas is diluted by the air in the calibration tube, and the undiluted extraction gas is sent to the separation section. Separated into a single component gas,
Since the single component gas is detected by the corresponding detectors, not only can the separation accuracy of the separation section be sufficiently secured, but also the detection accuracy of the single component gas can be sufficiently secured.
Highly accurate analysis can be reliably performed. Further, after the analysis of one sample is completed, the extraction mechanism is washed by vacuuming to extract the next sample in order to analyze the next sample, so that not only the washing time can be shortened, but also the washing operation is simple and easy. Becomes Therefore, a practical and highly reliable analyzer can be provided by greatly shortening the analysis processing time and improving the analysis accuracy, and the effect is more remarkable particularly when the number of oil-filled electric devices is large.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. 1 to 3, the same parts as those in FIGS. 4 to 7 are denoted by the same reference numerals. The analyzer of the embodiment is
It is roughly divided into an extraction mechanism for extracting a dissolved gas from the insulating oil 1 as a sample, and a separation / analysis mechanism for separating the extracted gas into a single component and detecting the single component gas. Have been.

More specifically, the extraction mechanism has a deaeration section 19 and a calibration tube 4 connected to the deaeration section 19 via a switching cock 18. The deaeration unit 19 is for extracting dissolved gas from the insulating oil 1 as a sample in the oil sampling bin 2 and is connected to the oil sampling bin 2 disposed below the oil sampling bin 2 via a switching cock 15. A stirrer 17 for stirring the inside is built in, and a heating means (not shown) for heating the inside is provided. A pressure gauge 16 for measuring the internal pressure is mounted on the upper part of the degassing part 19, and the gas outlet side on the upper part is connected to the intake side 4 a of the calibration tube 4 via the switching cock 18. On the other hand, the calibration tube 4 has the intake side 4a and the sending side 4a.
b is connected to one of the flow path switching valves 13 as shown in FIG.
Is connected to the gas outlet side. In this embodiment, the flow path switching valve 13 is constituted by a six-way valve, and is switched as shown in FIG. 1 when extracting a dissolved gas, and is switched as shown in FIG. 2 when separating and analyzing the extracted gas. The extraction mechanism causes the degassing unit 19 to extract dissolved gas from the insulating oil 1,
Further, there is provided a vacuuming means for sending the extracted gas to the calibration tube 4. The vacuum pumping means includes a vacuum pump 20 connected to a position halfway on the feeding side 4b of the calibration tube 4;
It has the switching cock 18 installed in the pipe between the intake side 4a of the calibration tube 4 and the degassing section 19, and the switching cock 15 installed in the pipe between the degassing section 19 and the oil sampling bin 2. When extracting the dissolved gas, the vacuum pump 20 is evacuated by evacuating when the flow path switching valve 13 is in the switching state shown in FIG. 1 and the switching cock 18 is opened and the switching cock 15 is closed. 19 and the inside of the calibration tube 4 are reduced to a predetermined gauge pressure (-760 mmHg). When the switching cock 18 is closed and the switching cock 15 is opened while the degassing section 19 and the inside of the calibration tube 4 are evacuated, the pressure in the oil sampling bin 2 and the degassing section 1 are reduced.
Due to the difference from the pressure in the vacuum pump 9, the insulating oil in the oil sampling bin 2 is sucked into the degassing unit 19, and the dissolved gas is extracted from the sucked insulating oil to the upper part in the degassing unit 19. In this case, when extracted into the deaeration section 19, the deaeration section 1
9, the pressure is higher than the initial vacuum pressure (> -760 mmHg), that is, higher than the pressure in the calibration tube 4, so that the switching cock 1 is in this state.
5 and the switching cock 18 are opened, the degassing section 1 is opened.
The extraction gas in 9 is sent out to the calibration tube 4 via the switching valve 18 and the intake side 4a. In addition, the vacuum pump 20 discharges the air evacuated to the atmosphere.

The separation / analysis mechanism has a separation unit 5, respective detectors, and a calculation unit 9. The separation section 5 has porous particles inside, and when the extraction gas in the calibration tube 4 is supplied, separates into a single component gas by the adsorption and desorption of the porous particles. Each of the detectors detects a combustible gas passing therethrough by burning it, and a combustible gas detector 8 of a contact combustion type or a thermal linear semiconductor type, and carbon dioxide which detects carbon dioxide by an infrared absorption function. It comprises a detector 7 and a carbon monoxide detector 6 for detecting carbon monoxide by performing a constant potential electrolysis, and these detectors 8, 7, 6 are sequentially provided at the outlet side of the separation unit 5. The calculation unit 9 includes the detectors 6 to 8
By calculating based on the detection signal from the respective components, the concentration of each gas is obtained for each single component. Also, the separation / analysis mechanism normally supplies the air only from the pump 11 when the flow path switching valve 13 is switched as shown in FIG. , 7, and 6 are stabilized. That is, the pump 1
The air from 1 stabilizes the functions of the separation unit 5 and the respective detectors by being normally sent in the direction of the separation unit 5, and when the extraction gas is sent into the calibration tube 4,
When the flow path switching valve 13 is switched to the intake side 4a by being switched as shown in FIG. 2, it functions as carrier air for sending out the extracted gas in the calibration tube 4 toward the separation section 5. In addition, a water vapor removal filter 10 is provided on the suction side of the pump 11 to remove moisture of the air sucked from the atmosphere. Further, the separation unit 5 as the separation / analysis mechanism and a pipe having the respective detectors 6 to 8 are accommodated in a thermostat 21. The thermostat 21
In particular, when the temperature around the combustible gas detector 8 is low, it is difficult for the detector 8 to function satisfactorily. Therefore, by maintaining the inside at a predetermined temperature, the combustible gas detector 8 Is configured to be able to maintain the detection function of satisfactorily. Therefore, although not shown, the thermostat 21 is provided with a heating means for maintaining a predetermined temperature.

The analyzer of the embodiment has the above-described configuration. Next, the operation will be described. First, when extracting the dissolved gas, the flow path switching valve 13 is switched to the state shown in FIG. 1 and the pump 11 is operated, so that air as carrier air is supplied from the outside air to the pump 1 through the water vapor removal filter 10.
1 is drawn into the constant temperature bath 21 through the flow path switching valve 13, and the inside of the constant temperature bath 21 is maintained at a predetermined temperature. 7. Check that each of the carbon monoxide detectors 6 is in a stable state. Thereafter, the oil sampling bin 2 from which a predetermined amount of the insulating oil 1 to be analyzed and analyzed is set in advance to a position below the deaeration unit 19, and then the switching cock 15 is set.
Is closed, the switching cock 18 is opened, and the vacuum pump 20 is driven so that the calibration tube 4 and the degassing section 1 are opened.
Vacuum is applied to the space between 9 and reduced to a gauge pressure (-760 mmHg). When the switching cock 18 is closed and the switching cock 15 is opened after evacuating to the gauge pressure, the insulation in the oil sampling bin 2 is caused by the difference between the pressure in the deaeration unit 19 and the pressure in the oil sampling bin 2. The oil 1 is sucked into the deaeration section 19 via the switching cock 15, and the dissolved gas in the insulating oil 1 is extracted. At this time, the suctioned insulating oil 1 is stirred by the stirrer 17 in the deaeration unit 19,
Since the inside is heated by heating means not shown,
More dissolved gas can be extracted. Degassing unit 1
When the dissolved gas is extracted in step 9, the switching cock 18 is opened, and when the switching cock 15 is closed, the dissolved gas in the degassing section 19 is changed due to the difference between the pressure in the degassing section 19 and the pressure in the calibration pipe 4. It is sucked into the calibration tube 4 via the intake side 4a. This is because the pressure in the degassing section 19 when the dissolved gas is extracted becomes a pressure (> -760 mmHg) higher than the initially evacuated gauge pressure, and the difference between the pressure and the gauge pressure in the calibration tube 4 is obtained. The dissolved gas is sucked into the calibration tube 4 due to the difference. Thereafter, when the flow path switching valve 13 is switched as shown in FIG.
Is connected to the take-in side 4a of the calibration tube 4, and the sending side 4b of the calibration tube 4 is connected to the separation unit 5 in the thermostat 21, so that air as carrier air flows in the calibration tube 4. The extraction gas is sent to the separation unit 5. When the extraction gas passes through the separation unit 5 in the thermostatic bath 21, the extraction gas is separated into single component gases by the separation unit 5.
By sequentially passing each of the combustible gas detector 8, the carbon dioxide detector 7, and the carbon monoxide detector 6, a corresponding type of gas is detected. On the other hand, when each of the detectors 8, 7, and 6 detects a corresponding type of gas, the calculation unit 9 calculates the concentration of the detected gas by performing calculation based on each output signal as shown in FIG. I will ask. In FIG. 3, the waveform of the combustible gas detector 8 is output with a delay compared to the respective detectors 6 and 7 of carbon monoxide and carbon dioxide. This is because the detection time differs depending on the characteristics. The gas that has passed through the thermostat 21 is released to the atmosphere. When the analysis of one sample, the insulating oil, is completed in this way, the inside of the pipe is washed to analyze the next sample. In that case, in the thermostat 21, the flow path switching valve 13 is switched as shown in FIG.
To purify. In the deaeration unit 19, after the insulating oil 1 is emptied by collecting it in the oil collecting bin 2 or a waste oil tank (not shown), the switching cock 15 is closed, the switching cock 18 is opened, and the vacuum pump is The space between the degassing section 19 and the calibration tube 4 is purified by evacuating at 20 and preparing for the next sample by reducing the pressure to the gauge pressure.

As described above, in the present embodiment, the deaeration section 19 and the calibration tube 4 are evacuated in advance, and deaeration is performed by utilizing the pressure difference between the deaeration section 19 and the oil collecting bin 2. Since the dissolved gas is extracted into the portion 19 and the extracted gas is sent to the calibration tube 4 by utilizing the pressure difference between the degassing portion 19 and the inside of the calibration tube 4, the dissolved gas is quickly removed from the insulating oil 1. Can be extracted. As a result, in the third conventional technique which is extracted by the air bubbling method, 15
In this embodiment, it takes about one minute, and the extraction can be performed very quickly. Further, as described above, since the extraction gas from the degassing unit 19 is sent to the evacuated calibration tube 4, there is no possibility that the extraction gas is diluted by the air in the calibration tube 4, and the extraction gas is not diluted. Since the extracted gas is sent to the separation unit 5 to be separated into a single-component gas, and the single-component gas is detected by the corresponding detectors 8, 7, and 6, the separation accuracy of the separation unit 5 is sufficiently high. As a result, the detection accuracy of the gas of a single component can be sufficiently ensured, so that highly accurate analysis can be reliably performed. Further, after the analysis of one sample is completed, the space between the degassing unit 19 and the calibration tube 4 is washed by vacuuming with the vacuum pump 20 in order to analyze the next sample, so that the washing time can be reduced only. In addition, the cleaning operation is simple and easy. For this reason, the conventional technique shown in FIGS. 4 and 6 requires 45 minutes per sample as the time for gas extraction / analysis and cleaning of the inside of the pipe, but in the example, 15 minutes.
Since it takes only about a minute, the efficiency of analysis work in a certain time can be greatly improved. Further, in the illustrated embodiment,
The deaeration section 19 has a stirrer 17 and heating means,
Is stirred and heated, the degassing action of the dissolved gas in the insulating oil 1 can be further promoted. In the third prior art, the degassing efficiency was about 60%, whereas the degassing efficiency was about 60%.
%. Further, the separating section 5 and the pipe having the respective detectors 8, 7, 6 are accommodated in a thermostat 21, and by maintaining the temperature in the thermostat 21, the flammable gas detector 8 functions particularly well. Therefore, high detection accuracy can be maintained as much as that, and there is no possibility that the detection function becomes unstable due to a change in the ambient temperature. Further, at the time of evacuation, extraction of the dissolved gas, and transport of the extracted gas to the separation section 5, the operation of the vacuum pump 20 and the flow switching valve 1
Although the example in which the switching of the switching cock 3 and the opening and closing of the switching cocks 15 and 18 are performed manually has been described, if a control means capable of automatically operating them is provided, the analysis can be performed automatically, and the analysis can be automated. obtain. According to the present apparatus, since the extracted gas can be separated and analyzed with high accuracy, the specific gas serving as a judgment index when performing the dissolved gas-in-oil degradation diagnosis described in Vol. An abnormal part of the oil-filled electrical equipment can be accurately diagnosed from the occurrence of the gas, the gas pattern, and the composition ratio, the abnormal part can be detected early, and an accident can be prevented.

[0012]

As described above, according to the present invention, the dissolved gas is extracted into the deaeration section by utilizing the pressure difference between the deaeration section and the oil collecting bin of the extraction mechanism which has been previously evacuated. In addition, since the configuration is such that the extracted gas is sent to the calibration tube by utilizing the pressure difference between the degassing section and the calibration tube, the dissolved gas can be quickly extracted from the insulating oil, and the undiluted extracted gas is sent to the separation section. The gas is separated into single-component gases, and the gas is detected by the corresponding detectors, so that highly accurate analysis can be performed reliably. Since the washing is performed, not only the washing time can be shortened, but also the washing operation becomes simple and easy. Therefore, the analysis processing time is greatly shortened and the analysis accuracy is improved, so that a practical and highly reliable analyzer can be provided. And especially If the number of filled electrical equipment often have more remarkable effect.

[Brief description of the drawings]

FIG. 1 is an explanatory piping diagram showing one embodiment of a gas extraction method of an apparatus for analyzing gas in oil according to the present invention.

FIG. 2 is an explanatory piping diagram when analyzing an extracted gas.

FIG. 3 is an output waveform diagram showing a detection state of each detector.

FIG. 4 is a piping diagram showing a configuration example of a conventional technique.

FIG. 5 is an output waveform diagram showing a detection state of each detector in FIG. 4;

FIG. 6 is a piping diagram showing another configuration example of the prior art.

FIG. 7 is an output waveform diagram showing a detection state of each detector in FIG. 6;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Insulating oil, 2 ... Oil sampling bottle, 19 ... Degassing part, 4 ... Calibration tube, 5 ... Separation part, 6 ... Carbon monoxide detector, 7 ... Carbon dioxide detector, 8 ... Combustible gas detector, 9 … Calculating unit, 15,
18: switching cock, 20: vacuum pump, 21: constant temperature bath.

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yoshihiko Kaneko 46-1 Tomioka, Nakajo-cho, Kitakanbara-gun, Niigata Inside Hitachi, Ltd. Nakajo Plant (72) Inventor Takashi Kiryu 46-Tomioka, Nakajima-cho, Kitakanbara-gun, Niigata 1 Inside the Nakajo Plant of Hitachi, Ltd. (72) Inventor Tsukasa Yoneyama 2-4-1 Nishi-Atsujigaoka, Chofu-shi, Tokyo Tokyo Electric Power Company, Ltd. (72) Koichi Murata 2-4-1, Nishi-Atsujigaoka, Chofu-shi, Tokyo No. 1 Tokyo Electric Power Company Technical Research Institute (56) References JP-A-1-227045 (JP, A) JP-A-54-126591 (JP, A) JP-A-1-112445 (JP, U) JP-A 1-64053 (JP, U) Papers of the 72nd Ordinary General Meeting of the Japan Electrical Association, June 3, 1993, p. 78-79 (58) Field surveyed (Int. Cl. ⁷ , DB name) G01N 1/00-1/34 JICST file (JOIS)

Claims (1)

(57) [Claims] 1. An extraction mechanism having a degassing section for extracting dissolved gas from insulating oil in an oil sampling bin, a calibration pipe for taking in the extracted gas in the degassing section, and extracting gas from the calibration pipe for each single component. A separation unit that separates each gas, a detector that detects the gas of each single component separated by the separation unit by type, and an operation that analyzes the concentration of the gas of each single component based on the detection of each detector The extraction mechanism evacuates the calibration tube and the degassing unit, and dissolves the dissolved gas in the insulating oil into the degassing unit by the difference between the pressure in the degassing unit and the pressure in the oil sampling bin. An apparatus for analyzing gas in oil, characterized by comprising vacuum means for extracting and extracting the extracted gas into the calibration tube by a difference between the pressure in the degassing section and the pressure in the calibration tube.