JPS63200508A - Method for adjusting gas pressure of gas-insulated electromagnetic induction apparatus - Google Patents

Abstract

PURPOSE:To miniaturize a gas pressure adjustment apparatus and a gas store tank by causing the gas pressure adjustment apparatus to operate its function so that a mixed gas pressure in a storage vessel can be constant in a range of minimum working temperature and the specified working temperature. CONSTITUTION:A coil 1 and a core 2 are housed in a storage vessel 3 and a gas store tank 10 where a mixed gas 4 mixed by insulating gas and cooling medium are kept in store is installed at the storage vessel 3. A gas pressure adjustment device that is composed of a pressure control part 11, a pressure detector 12, a compressor 13, a control valve 14 as well as a piping 15 is mounting between the gas store tank 10 and the storage vessel 3. A mixed gas in the storage vessel 3 operates the gas pressure adjustment device so that a mixed gas pressure can be constant in a range of a minimum working temperature and the specified working temperature. And its device does not operate in the range of the specified working temperature and the maximum working temperature and then a pressure of the storage vessel 3 is allowed to depend on variations of the temperature. In this way, a reduction of an insulating gas feeding between the storage vessel 3 and the store tank 10 makes the gas pressure adjustment device as well as the gas store tank 10 more compact.

Description

[Detailed Description of the Invention] [Field of Industrial Application] This invention adjusts the pressure in a tank filled with a mixed gas of a non-condensable insulating gas and a condensable refrigerant. The present invention relates to a gas pressure adjustment method for gas-insulated electromagnetic induction equipment.

[Conventional technology]

Figure 2 is a schematic configuration diagram showing a conventional gas insulated transformer disclosed in Japanese Patent Application Laid-Open No. 59-186312. A container (4) contains a non-condensable insulating gas and a refrigerant having condensing and insulating properties to insulate and cool the winding (1) and core (2). (5) is a refrigerant liquid in which the refrigerant is in a liquid phase.

(6A) is a refrigerant liquid cooler attached to the container (3) for cooling the heat generated from the winding m (1) and the iron core (2), (7), (8A), (8B), (9 ) are windings (1) with refrigerant liquid (5) respectively.

The pump, piping, and sprayer (10) for dispersing K in the iron core (2) are a gas storage tank attached to the container (3).

(11) is the pressure control unit, (12) is the pressure detector that detects the gas pressure in the container (3).% ('') is from the volume (3) to the gas storage tank (10) or from the gas storage tank (10). volume(
6) is a compressor capable of pumping the mixed gas (4) in both directions, (14) is a control valve, (15) is a pipe that communicates the volume (3) with the gas storage tank (10), and (16) is a pressure detector (17) that measures the gas pressure in the gas storage tank (10);
is a control valve, (18) is a gas storage tank (
When the refrigerant liquid condensed from the refrigerant gas in the mixed gas (4) in 10) exceeds a specified value (detected by a liquid level gauge (not shown) in the gas storage tank (10)), the refrigerant liquid (5) is volume(
A bypass pipe (19) communicates the volume (3) with the bottom of the gas storage tank (4) in order to return the mixture gas to the mixed gas (4). Then, the pressure control section (
11), pressure detector (12), compressor (13) control valve (
14) and piping (15) constitute a gas pressure regulating device.

In the conventional gas insulated transformer configured as described above, as shown in Figure 3, the temperature within the volume (3), which changes depending on the load of the gas insulated transformer and changes in ambient temperature, is the minimum operating temperature. Between the temperature and the predetermined operating temperature θ5 determined according to the required dielectric strength, the mixed gas (4) is supplied and discharged between the volume (3) and the gas storage tank (10) to maintain the temperature within the volume (6). The pressure of is adjusted between P and P2. On the other hand, between the predetermined operating temperature θ5 and the minimum operating temperature θ, the pressure is adjusted according to the pressure/temperature characteristics of the mixed gas (4) with the curves (b, -a,) (temperature θ5) shown in the figure. The area surrounded by the curve (b, -a2) (when the temperature is θ5 and the pressure is P2) (the shaded area in FIG. 3) is allowed to change.

Then, there is a high temperature region, that is, a predetermined operating temperature θ5 and a maximum operating temperature θ. Part of the insulating gas is exhausted into the gas storage tank (10) together with the refrigerant gas, but the refrigerant liquid (5)
) has a high vapor pressure, the partial pressure of the refrigerant gas becomes large, and since this refrigerant gas has a high dielectric strength, it sufficiently compensates for the amount of insulating gas exhausted into the gas storage tank (10). In addition, in the region of low temperature (θ5 - θa), if the pressure in the volume (3) at the predetermined operating temperature θ5 is taken as a value between P and P2, the dielectric strength of the gas is originally lower than the gas pressure. Since the property is determined by the number of molecules (density), at temperatures below 1, the density of gas molecules does not change even if the pressure in the volume (3) decreases, and gas insulated transformers do not have sufficient dielectric strength. Guaranteed.

By adjusting the pressure in the volume (3) in this way, the maximum gas pressure can be suppressed to a low -1 value below P, and the entire operating temperature range (θ8 - θ.) can be maintained within the volume (3). Compared to adjusting the pressure by supplying and discharging the mixed gas (4) between the gas tank (10) and the gas storage tank (10), the amount of the mixed gas (4) to be supplied and discharged is smaller (thus, the volume of the gas storage tank (10) is reduced). be able to.

[Problem that the invention seeks to solve]

By the way, in the conventional gas insulated transformer as described above, as its capacity increases (and its calorific value increases), the amount of refrigerant liquid (5) used for cooling increases. Liquid (5) dissolves SF, gas, and has the property of dissolving a large amount (dissolved) at low temperatures. Therefore, in a large capacity, the amount of refrigerant is large (・, so the insulating gas in volume (3) at low temperature The amount dissolved in the refrigerant liquid (5) increases and the mixed gas (4
) The decrease in the molecular density of the insulating gas in ) cannot be ignored.
In the temperature range below the predetermined operating temperature 05 in Figure 3, the dielectric strength of the gas insulated transformer cannot be ensured, especially in the low-temperature part near the lowest operating temperature θa K, and as a result, the volume is reduced over the entire operating temperature range (θ.-〇a). (3) It is necessary to adjust the gas pressure in
The amount of insulating gas supplied and discharged between the volume (3) and the gas storage tank (10) increases, and the gas pressure regulator and gas storage tank (10)
) had the problem of increasing in size.

This invention was made to solve this problem, and the amount of insulating gas supplied and discharged between the volume and the gas storage tank is reduced, so that the gas pressure regulator and the gas storage tank can be made smaller. The purpose is to obtain a gas pressure adjustment method for insulated electromagnetic induction equipment.

[Means for solving problems]

The gas pressure adjustment method for gas-insulated electromagnetic induction equipment according to the present invention operates the gas pressure adjustment device so that the pressure of the mixed gas in the volume falls within a certain range between its minimum operating temperature and a predetermined operating temperature. It is something that makes you

[For production]

In this invention, the gas pressure regulating device is operated,
The mixed gas is supplied and discharged between the container tank and the gas storage tank, and the pressure of the mixed gas in the container tank is adjusted within a predetermined range between its minimum operating temperature and a predetermined operating temperature. On the other hand, between the predetermined operating temperature and the maximum operating temperature of the mixed gas, the gas pressure regulating device does not operate, and the mixed gas is not supplied or discharged between the container tank and the gas storage tank.

〔Example〕

An embodiment of this invention will be described below. The structure of the gas insulated transformer is exactly the same as that of the conventional one, and its explanation will be omitted.

First, when the gas insulated transformer is stopped, the load is light, and the ambient temperature is low, a large proportion of the insulating gas in the container (3) dissolves in the refrigerant (5). Tank (
3) The pressure of the mixed gas (4) in the compressor (
13) to remove the mixed gas (4) in the gas storage tank (10).
is replenished into the tank (3), and the pressure inside the tank (3) is maintained at least at a value equal to or higher than P2 in Figure 1.

When a gas insulated transformer is operated or under heavy load, the windings (
1) The temperature rises in the vessel (6) due to heat generation within the iron core (2), and the pressure rises due to expansion of the mixed gas (4) and increase in vapor pressure of the refrigerant liquid (5). This value is P in Figure 1,
When the gas reaches the gas storage tank (10), the compressor (13) is operated in the opposite direction to transfer the mixed gas (4) from the container (3) to the gas storage tank (10).
).

As described above, the pressure in the container tank (6) is maintained at a value between P and P between the minimum operating temperature θ8 and the predetermined operating temperature θ5. At this time, the container tank (5) and the gas storage tank (1
The amount of response of the insulating gas among the mixed gas (4) supplied and discharged between the tank (5) and the minimum operating temperature θ8 is the pressure P,
This is the difference between the amount of insulating gas in the container (3) when , and the amount of insulating gas in the container (3) at the same predetermined operating temperature θ5 and pressure P2.

The control valve (
14) and (17) are closed, and the pressure inside the tank (6) changes according to the temperature change, following the curve (bI-01) in Figure 1 (when the pressure is P at the predetermined operating temperature θ5). (b2C2
) (when the pressure is P2 at the predetermined operating temperature θ5) (inside the hatched area in the figure).

'Also, the mixed gas (4) exhausted into the gas storage tank (10)
After the refrigerant gas condenses and liquefies, when a certain amount of refrigerant gas is reached, the control valve (17) opens and the gas storage tank (1
0) is returned to the container tank (5).

As described above, the gas pressure adjustment range in the container tank (3) is maintained at a pressure equal to or higher than P2 even at the lowest operating temperature θ8, so the dielectric strength is sufficient.
Maximum operating temperature θ. Since the pressure at is PA, which is greater than the pressure P, it is necessary to strengthen the gas pressure design of the tank (3). However, the entire operating temperature range (θ8−θ
. ), the response amount of the insulating gas (the amount stored in the gas storage tank (10) at high temperatures and returned to the container (3) at low temperatures) is reduced, and the size of the gas storage tank (10) can be reduced. Can be done. Since this gas storage tank (10) compresses and stores the mixed gas (4), its working pressure is high, and the advantage of making it smaller is that the tank (6) can be used up to a pressure PA slightly higher than Pl. The disadvantage is greater than that.

In the above embodiments, the present invention has been described using a gas insulated transformer, but it goes without saying that it can also be applied to other electromagnetic induction devices such as a gas insulated reactor.

〔Effect of the invention〕

As explained above, according to the gas insulated electromagnetic induction device of the present invention, the compressor and the pressure The gas pressure regulator, which is equipped with a control unit, etc., is activated, but between the predetermined operating temperature and the maximum operating temperature, the gas pressure regulator does not operate, and the pressure inside the container is left to change in temperature. The amount of insulating gas supplied and discharged between the container and the gas storage tank is reduced, the gas pressure adjustment device and the gas storage tank can be downsized, and the manufacturing costs of the gas pressure adjustment device and the gas storage tank are reduced. Additionally, the installation area for gas-insulated electromagnetic induction equipment is reduced by 1 unit.

[Brief explanation of the drawing]

FIG. 1 is a relationship diagram showing the relationship between the temperature and pressure of a mixed gas in a container showing an embodiment of the present invention, FIG. 2 is a schematic configuration diagram of the present invention and a conventional gas insulated transformer, and FIG. The figure is a relationship diagram showing the relationship between the temperature and pressure of a conventional mixed gas in a container. mouth)...Winding, (2)...Iron core, (3)e/Container, (4
)...Mixed gas, (10)...Gas storage tank. In each figure, the same reference numerals indicate the same or corresponding parts. Figure 1 PF) Figure 3 Temperature

Claims (2)

[Claims] (1) A container in which the windings and iron core are stored, a gas storage tank attached to this container that stores a mixed gas of a non-condensing insulating gas and a condensing refrigerant, and this gas In the gas insulated electromagnetic induction device, the gas insulated electromagnetic induction device includes a gas pressure regulating device that is provided between a storage tank and the container tank and fills the container tank with the insulating gas and the refrigerant. The gas pressure regulator is operated so that the pressure falls within a certain range between the minimum operating temperature and a predetermined operating temperature, and the gas pressure regulator is not operated between the predetermined operating temperature and the maximum operating temperature. A gas pressure adjustment method for gas insulated electromagnetic induction equipment, characterized in that the pressure inside the gas tank is left to temperature changes. (2) A method for adjusting gas pressure in a gas-insulated electromagnetic induction device according to claim 1, wherein SF_6 gas is used as the insulating gas and fluorocarbon C_8F_1_6O is used as the refrigerant.