JPH0676954B2 - Cleaning method for measuring dissolved gas in oil - Google Patents

Description

TECHNICAL FIELD The present invention relates to a cleaning method for an apparatus for measuring dissolved gas in oil.

(Prior art) To measure the gas dissolved in oil, a bubbling gas such as air is introduced into the sample oil in the extractor that has been extracted from electrical equipment in the form of bubbles, and the gas dissolved in the oil is introduced. Dissolved gas in oil, which was taken into air bubbles and the extracted gas was collected in a gas recovery container to measure the gas and the extracted gas collected in the gas recovery container was returned to the extractor by a pump and circulated. The measuring device has been separately proposed by the present inventor.

In such a measuring device, when the measurement of one kind of sample oil is finished and the measurement of another sample oil is performed next, it is necessary to wash the inside of the device prior to the measurement.

Conventionally, the sample oil of the previous time was opened by opening the lid of the extractor, the sample oil was discharged from here, and then air was introduced into and discharged from the gas recovery container and each pipe to clean the inside.

(Problems to be solved by the invention) However, in the circulation bubbling method described above, even after the measurement is completed, since the dissolved gas remains in the sample oil, even after discharging the sample oil from the extractor, The dissolved gas will remain in the extractor.

Therefore, according to the conventional cleaning method, a positive error may occur when measuring low-concentration oil after measuring high-concentration oil.

An object of the present invention is to enable cleaning that does not affect the next measurement in a short time.

(Means for Solving the Problem) The present invention relates to an example of a pipe for connecting an extractor and a gas recovery container with the sample oil, which was the object of the previous measurement, kept in the extractor before starting the next measurement. By opening the part, introducing air from the open part, circulating through the extractor, gas recovery container and each pipe, and then discharging it, it is repeatedly washed until the gas concentration inside each becomes about the outside gas concentration. Then, after the sample oil is discharged from the extractor, the sample oil to be measured next is measured.

(Function) When air is repeatedly circulated while the sample oil of the previous measurement target is kept in the extractor, the dissolved gas remaining in the sample oil as well as inside the extractor, gas recovery container, and piping It will be discharged to the outside.

After that, the sample oil is discharged, but even after the discharge,
It is clear that no dissolved gas remains. Therefore, even if the sample oil for the next measurement is put into the extractor for measurement, the concentration of the previous sample oil is not affected.

(Example) An example method of the present invention will be described. The figure shows an apparatus for detecting dissolved gas in oil used for carrying out this method, and 1 is an extractor in which a sample oil 2 is put. Further, a bubble generator 3 including a ball filter, a bubble generating tube, etc. inside.
Is installed. At the time of measurement, the extractor 1 is hermetically closed, and a bubbling gas such as air is introduced into the bubble generator 3 from the outside via the pump 10.

Bubbles are generated by this air. The gas contained in the sample oil 2 is contained in the bubbles. This extracted gas is sent to the gas recovery container 6 through the pipe 5, and the gas is detected by the gas sensor 7 there.

The detected value is converted into an electric signal and amplified by the amplifier 8. Then, the detected amount is instructed to the meter 9. As the gas sensor, for example, a semiconductor sensor such as a metal oxide such as SnO ₂ or ZnO is used.

The extraction gas in the gas recovery container 6 is piped by the pump 10.
It is returned to the extractor 1 via 11. In this way, the extracted gas is repeatedly circulated, and the gas concentration is measured in the process. The above operation is not particularly different from the operation of this type of device proposed separately.

When the measurement of the dissolved gas of the sample oil is completed, the cleaning is performed before the start of the next measurement. According to the present invention, the pipe 11 is first used while leaving the previous sample oil in the extractor 1.
Is partially opened and the inlet 12 and the outlet 13 are connected.

Specifically, the piping 11 is provided with switching valves 14 and 15, and by switching the switching valves 14 and 15, the inlet 12 and the outlet
13 and 13 are switched and connected to the pipe 11.

Then, fresh air outside is sucked into the pipe 11 through the suction port 12 and fed into the extractor 1. The sent air is discharged from the extractor 1 through the pipe 5, the gas recovery container 6, and the pipe 11 to the outside through the discharge port 13 by the action of the pump 10. This air circulation is continuously performed for the required time.

Then, when the gas concentration of each part is almost the same as the external gas concentration, return the switching valves 14 and 15 to their original positions, and the suction port 12 and the discharge port.
13 is separated from the pipe 11, the pipes 5 and 11 are removed from the extractor 1, and the sample oil in the extractor 1 is discharged. Then add the sample oil for the next measurement and perform the same measurement as above.

When the cleaning is performed in this manner, most of the dissolved gas remaining in the sample oil in the extractor 1 is replaced with the fresh air outside. Therefore, even if a new sample oil is added after discharging this sample oil, the next measurement can be performed without being substantially affected by the gas concentration of the previous sample oil.

Next, an experiment conducted by the present inventor will be described. Insert 33 ml of sample oil with hydrogen gas as dissolved gas in the extractor 1 and set the air introduction / exhaust speed at the inlet 12 and the outlet 13 to 1
/ Min, and the washing time was 2 minutes.

First, the sample oil with a gas concentration of 5000 ppm is measured (first measurement), then washed as described above, and then the sample oil with a gas concentration of 0 ppm is measured (second measurement), and then as described above. After cleaning to a gas concentration of 50
The measurement was performed on the sample oil of 0 ppm (third measurement), and after cleaning as described above, the measurement of the sample oil having a gas concentration of 0 ppm was performed (fourth measurement).

The following table shows the meter readings for each measurement. For comparison, when the sample oil is discharged from the extractor and then air is introduced and discharged to a portion other than the extractor (Comparative Example A) and when air is also introduced and discharged to the extractor (comparison For Example B), using the same sample oil as above,
The results measured under the same conditions are also shown. All units of concentration are ppm.

As can be understood from the above results, in the case of the comparative example, each measurement after the second measurement is influenced by the previous measurement, and the meter indicates a gas concentration value higher than the actual gas concentration. It turns out. On the other hand, in the present experimental example, it is understood that the influence after the high-concentration measurement is slight, and the influence after the low-concentration measurement is hardly influenced.

(Effects of the Invention) As described in detail above, according to the present invention, even when the concentration of dissolved gas in oil is repeatedly measured, it is short enough to be measured without being affected by the concentration of the previous sample oil. It has the effect of being able to wash in time.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a layout diagram showing a configuration for carrying out the method of the present invention. 1 ... Extractor, 2 ... Sample oil, 3 ... Bubble generator, 5,11
…… Piping, 6 …… Gas recovery container, 7 …… Gas sensor, 10
...... Pump, 12 …… Suction port, 13 …… Discharge port,

Claims (1)

[Claims] 1. An apparatus for measuring dissolved gas in oil, comprising: an extracting apparatus for extracting dissolved gas in sample oil in an extractor by circulating bubbling gas; and a measuring apparatus for measuring the concentration of the extracted dissolved gas in oil. After the completion of the measurement, while leaving the sample oil in the extractor, air was introduced into and discharged from the extractor and the measuring device for cleaning, and then the sample oil in the extractor was discharged. A method for cleaning a device for measuring dissolved gas in oil, which is characterized.