JP2844200B2 - Gas in oil detector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an in-oil system that automatically detects gas dissolved in insulating oil of power substation equipment such as an oil-immersed transformer and determines abnormality of the equipment. The present invention relates to a gas detection device. Various insulating materials and insulating oils are sealed in transformers and the like.However, when discharge or local overheating occurs, thermal decomposition of these insulating materials occurs, and H ₂ , Co ₂ , Co, CH ₄ , C _{4 2 H 4, C 2 H 6} , gaseous substances such as occurs in dissolved in the insulating oil. Therefore, by examining the amount and type of gas in the insulating oil, it is possible to determine whether the oil-filled equipment is normal or abnormal.

[Prior art] Abnormality diagnosis of equipment performed by gas in oil is conventionally performed by a detection tube method using the color reaction of gas in oil, an optical interferometer method using the difference in the refractive index of gas, and combustible from combustion heat. In addition to the method of measuring and judging the concentration of the reactive gas component, there is a method of extracting insulating gas by extracting the gas and analyzing it, and a method of separating and analyzing gas from oil using a polymer membrane. Are known. Among the methods described above, the conventional method of extracting insulating oil, extracting gas, and analyzing it is as follows. Take out the sample oil from the oil filling device with an oil sampling pump, measure this sample oil to a certain amount, and then use a vacuum pump. Or by using a decompression cylinder, decompression bellows, etc. to release the gas into a space decompressed to separate gas from oil,
The separation gas is sent to the measuring device to diagnose the abnormality. The method also using a polymer film, so that to prevent liquid, attached to the transformer polymer film such as a fluorine-based resin or a polyimide resin that transmits only the gas is constantly monitored and transmitted to a H ₂ gas sensor, etc. It was made.

[Problems to be Solved by the Invention] Among the above-mentioned conventional methods, the detection tube method, the optical interferometer method, and the method of measuring the concentration of combustible gas by combustion all require the rapid inspection of a large number of sample oils. Is not appropriate for
In addition, the analyzer is complicated, and the operation requires skill. In the conventional method of collecting sample oil and separating gas, a pump for extracting sample oil from oil filling equipment, a device for collecting a certain amount of sample oil, and a vacuum for decompression used for gas separation A pump or a decompression cylinder or bellows and a device to drive it, a gas detection device, etc. are provided independently. However, there is a problem in that a complicated control mechanism is required to operate the device, the cost of the device is high, and the maintenance and management are troublesome and costly. In addition, the method using a polymer membrane has the advantage that there is no need to collect the sample oil and the separated gas can be monitored at all times.
There are problems such as limitations on the types of gases that can be detected and difficulty in measuring within a short time.

[Means for Solving the Problems] The present invention solves such a problem and makes it possible to simplify the configuration to reduce the size of the entire apparatus and to maintain a highly reliable gas detection capability for a long time. An apparatus for detecting gas in oil is provided.

The means include a cylinder having a decompression chamber and a hydraulic pressure generation chamber, a piston provided in each of the chambers and connected to each other, a means for supplying oil to each of the chambers, It has a means for keeping the amount of oil in the chamber constant, a means for promoting a gas-liquid separation operation of oil in a decompressed state, a gas separation chamber connected to the decompression chamber, and a gas detection means connected to the gas separation chamber. It is a gas in oil detection device.

Embodiment FIG. 1 is a diagram showing an example of a gas-in-oil detection device of the present invention. In FIG. 1, 1 is a gas detection device in oil, 2 is a cylinder, 3 is a vacuum generation chamber (decompression chamber), 4 is a hydraulic pressure generation chamber,
5 and 6 are pistons, 7 is a rod, 8 and 14 are magnetic stirrers, 9 is an oil pump, 10 is a gas detector, 11 is a gas detector, 12 is a gas pump, 13 is a limit switch, and 15 is a level switch (gas separation chamber). ), 16 is an oil mist filter, 17 is a strainer, 18 is a drain valve, 19 is a transformer, and 20 to 25 are solenoid valves. A procedure for detecting a component of gas in oil in the transformer 19 in the above configuration will be described below.

First, sample oil is sampled from the transformer 19 into the gas-in-oil detection device 1. When sampling, first, the valves 21, 24, and 25 are turned on (the other valves are off; the same applies hereinafter). When the oil pump 9 rotates forward, the sample oil is supplied from the transformer 19 to the valve 18, the strainer 17, and the valve 21.
Through the valve 20 and into the hydraulic pressure generating chamber 4 through the valve 20. One side of the piston 6 faces the hydraulic pressure generation chamber 4,
Since the opposite side faces the outside air, by continuing the forward rotation of the oil pump 9, the piston 6 is pushed to the outside air side, and comes into contact with the end of the cylinder 2 and stops. At this time, a sufficient amount of oil from the transformer 19 is sampled into the pressure reducing chamber 3 and the hydraulic pressure generating chamber 4 in the cylinder 2 so as not to be affected by old oil remaining in the piping system. And become full. At this time, in the system of the gas detector 10, the valves 24 and 25 are on and the gas pump 12 is operating, and the clean outside air sucked from the valve 25 is a level switch.
15, the operation of discharging to the atmosphere from the valve 24 through the oil mist filter 16, the valve 23, the gas detector 11, etc., thereby keeping the gas detection unit 10 always clean and We are ready.

Next, the valves 20, 21, 24, and 25 are turned on, and the oil pump 9 is turned on.
To reverse rotation. As a result, the sample oil filled in the decompression chamber 3 and the hydraulic pressure generation chamber 4 starts to be returned to the transformer 19 through the valves 20, 21 and 18. When the piston 5 advances in the direction in which the sample oil is discharged, and the sample oil in the decompression chamber 3 reaches a certain amount which is optimal for gas detection, the limit switch 13 is operated and the oil pump 9 is stopped. At this time, the system of the gas detection unit 10 is in a state of standby for detection by sucking and discharging the atmosphere similarly to the above-described stage.

Next, the valves 20, 23 and 24 are turned on, and the oil pump 9 is rotated forward. As a result, the pressure oil is continuously supplied into the hydraulic pressure generating chamber 4, the piston 6 moves to the atmosphere side, and the piston 5 connected to the piston 6 by the rod 7 also moves to the atmosphere side accordingly. The pressure in the sample oil 3 is reduced to a vacuum state, and the gaseous substance contained in the sample oil is separated and rises and stays in the upper part of the pressure chamber 3. At this time, the gas-liquid separation is effectively performed in a shorter time by flowing the sample oil using the magnetic stirrers 8, 14, and the like. In order to promote the separation of gaseous substances from the sample oil, in addition to the above-described magnetic stirrer, a method of applying vibration to the sample oil using a vibrator or ultrasonic waves may be used. At this time, in the system of the gas detection unit 10, the operation of discharging the air sucked from the valve 23 to the atmosphere from the valve 24 through the gas detector 11 is performed.

The piston 6 is moved to the end of the cylinder 2 to increase the degree of vacuum in the decompression chamber 3 and gaseous substances in the sample oil are separated at the upper part of the decompression chamber 3 and then the valves 20, 22, 23 and 24 are turned on. age,
The oil pump 9 is rotated in the reverse direction. As a result, the sample oil in the hydraulic pressure generating chamber 4 is returned to the transformer 19 through the valves 20 and 18, and accordingly, the piston 5 and the piston 6 connected by the rod 7 move to the pressure reducing chamber 3 side. The decompression chamber 3 communicates with the gas detection unit 10 via a valve 22, a level switch 15, and the like. The gaseous substance separated in the decompression chamber 3 is sucked by the gas pump 12 and flows into the gas detection unit 10. At this time, when the gaseous substance passes, the level switch 15 flows into the gas detection unit 10 in an open state, but when the liquid sample oil passes, the switch operates to shut off the passage, so that the gas detection unit is shut off. No liquid sample oil flows into 10. The gaseous substance passes through 15 parts of the level switch,
When the liquid sample oil reaches the level switch 15, the valve 20
And only the gas pump 12 is turned on, and all other valves and the oil pump are stopped. As a result, a mixed gas of a gaseous substance separated from the sample oil and air is sealed in the piping system of the gas detection unit 10. In this state, gas components are detected by the gas detector 11 while the mixed gas is circulated by the gas pump 12.

When the gas detection is completed, the valves 20, 21, 24 and 25 are turned on,
The oil pump 9 is rotated in the reverse direction. As a result, almost all of the sample oil in the decompression chamber 3 and the oil pressure generation chamber 4 in the cylinder 2 is returned to the transformer 19. Further, the gas detection unit 10 returns to the process of inhaling the outside air again and releasing it into the outside air through the gas detector 11, and performs scavenging of the gas detector 11 to prepare for the next detection.

[Effect of the Invention] As described in detail above, in the present invention, a vacuum generation chamber (decompression chamber) and a hydraulic pressure generation chamber are provided in an integrated cylinder, and a certain amount of oil is sampled by sending sample oil to the cylinder. It can go through decompression and gas separation process. In addition, the oil supply means necessary for the operation can be provided by an extremely simple configuration such as an oil pump and a solenoid valve, so that the oil supply and the vacuum generation can be performed by a simple oil pump without using another means. There is an advantage. If a reversible oil pump is adopted as in the above embodiment,
With the advantage that a fixed amount of sample oil, gas separation from the sample oil, and return of the sample oil to the equipment can be realized by a single oil pump and a simple process. I have. In addition, by performing gas detection in a sealed state without contact between the sample oil and the outside air from oil collection to oil return, it is possible to prevent the components of the sample oil from changing due to contact with the outside air. I have. In addition, by disposing a level switch (gas separation chamber) between the sample oil gas generating section and the gas detecting section, it is possible to improve the accuracy of gas detection and shorten the required time. Further, since the pipe communicating with the gas detecting portion is directly opened to the separated gas retaining portion of the decompression chamber, the gaseous substance separated from the sample oil is quickly sent to the gas detecting portion. This has the advantage that the repetition of gas-liquid separation from the gas can be performed within a short time.

[Brief description of the drawings]

FIG. 1 is a diagram showing an embodiment of the present invention. 1 ... Gas in oil detector, 2 ... Cylinder, 3 ... Vacuum generation chamber (decompression chamber), 4 ... Hydraulic generation chamber, 5,6 ... Piston, 7 ... Rod, 8,14 ... Magnetic Stirrer, 9 Oil pump, 10 Gas detector, 11 Gas detector, 12 Gas pump, 13 Limit switch, 15 Level switch (gas separation chamber), 16
Oil mist filter, 17 ... strainer, 18 ... oil drain valve, 19 ... transformer, 20-25 ... solenoid valve.

Continuation of front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G01R 31/00 G01N 1/22

Claims (1)

(57) [Claims] A cylinder having a pressure reducing chamber and a hydraulic pressure generating chamber;
Pistons provided in each of the chambers and connected to each other, means for supplying oil to each of the chambers, means for keeping the amount of oil in the decompression chamber constant, and promoting a gas-liquid separation operation of oil in a decompressed state A gas separation unit connected to the decompression chamber, and a gas detection unit connected to the gas separation chamber.