JPS5874023A - Transformer - Google Patents

Abstract

PURPOSE:To prevent deterioration of cooling capability due to the leakage of refrigerant by once storing refrigerant leaked from components of a refrigerant circulation circuit within a refrigerant pot and by returning this refrigerant to the refrigerant circulation circuit through a refrigerant feedback pipe. CONSTITUTION:A refrigerant A leaking from components of a refrigerant circulation circuit falls along coils 4, 5 etc. and enters the refrigerant pot 15 provided at the center of bottom part 1a of tank 1. When such refrigerant A reaches the predetermined level, such level is detected by a level detector 17. Then, such refrigerant A is transferred to a refrigerant tank 11 through a feedback pipe 16 by means of a pump 18 which is operated by a signal sent from the detector 17. The refrigerant A being transferred is then sent again to the cooling duct 9 together with other refrigerant A by the pump 12. Thereby, even if the refrigerant A leaks, the cooling capability is not deteriorated and the necessary cooling capability can alwasy be maintained.

Description

[Detailed description of the invention] (-) Technical distribution The present invention includes a foil-wound wire in which a metal seed and an insulating sheet are wound in layers, and a cooling duct through which a cooling medium is passed is built into the winding. Regarding transformers.

(b) Background of the Invention Foil-wound transformers equipped with foil-wound windings have a good space factor, are compact and
Because it has the feature of being lightweight, it is a small-capacity transformer C with a relatively low voltage of several kV or several hundred kVA.
: It has already been put into practical use and is widely available on the market.

Recently, considering its excellent advantages, research has been conducted to expand its application to higher voltage/larger capacity transformers (e.g. f275 kV, 300 MvA transformers), but the biggest key is how to improve the cooling capacity for the windings. Let me.

Is it possible to provide high insulation capacity to the windings?1 However, such high-voltage, large-capacity transformers have not yet been put into practical use. A so-called heat nozzle type is being considered in which a cooling duct is built into the winding and a refrigerant with excellent insulating properties is sent in to directly cool the heat generated from winding loss.

(e) Prior Art No.:1'' Figure 1a shows a transformer of this type. 0 In the figure, 1 is a tank filled with insulating oil or an insulating gas such as 8F*f as an insulating medium.

Inside this tank 1 (2) an iron core 2 is provided.

A low-voltage winding 4 is wound around the outside of the main leg 2a of the iron core 1 via an insulator 2, and a high-voltage winding 5 is wound around the outside of the low-voltage winding 4 via an insulating barrier 6. ing. These low-voltage windings 4 and high-voltage windings 5 are composed of foil-wound windings 12 formed by overlapping and winding a metal sheet 1 such as aluminum foil and an insulating sheet 1 such as a resin film. , each winding 4.5 is insulated by insulating oil or gas sealed in the tank 1.

Further, one cooling duct 9 is built inside the low voltage winding 4, and a plurality of cooling ducts 9 are built inside the high voltage winding 5, respectively. - This cooling metal 9 is a thin flat duct made of metal such as stainless steel and has an approximately circular tuna-like shape, and is wound around the winding 4.5. Inside this cooling duct 9, 7'
A refrigerant such as Ron-113 or Fe12 is passed through the winding 4 as it passes through the cooling mettle.
．． The windings are cooled by removing the heat generated in the refrigerant with the latent heat of evaporation of the refrigerant. And this refrigerant.

In the condenser 10, it is cooled and condensed by water cooling,
The liquefied refrigerant is stored in a refrigerant tank 11 and sent to a pump 12.
The winding 4.5 is fed into the provided cooling duct 9. That is, the refrigerant circulation circuit and the transformer are separated. In addition, the liquid guide pipe 13 that guides the refrigerant is made of metal such as stainless steel, but the connection between it and the cooling terminal (: is not tlkA ID 14) is used, and the liquid guide pipe 13 is made of metal such as stainless steel.
is insulated from the ground potential of tank 1 and the like. The potential of the cooling duct 9 is electrically coupled to the same potential as the windings 4,5 due to the windings 4.1 and 4.1.

In addition, in FIG. 1, windings 4, which are not directly related to the present invention,
5 Lee R wire and pull it out to the outside of tank 1! ,
The explanation is omitted.

瞠□・、- In transformers using this cooling method, the circulation circuit through which the refrigerant flows for cooling and the insulating medium for insulation are completely separated.For this reason, transformers using this method In particular, it is referred to here as a single-rate transformer.

Transformers using this cooling method utilize the latent heat of vaporization of the refrigerant, so you can expect excellent cooling characteristics.

Large capacity transformer guide=promising.

(d) Problems with the Prior Art The conventional seven-root type transformer has the following problems in terms of cooling.

That is, the cooling tank 9 provided inside the tank 1.
Parts for flowing the refrigerant, such as the liquid guide pipe 13, are manufactured under quality control to prevent refrigerant from leaking to the outside. The joints of these parts also have a joint structure that prevents refrigerant from leaking.

However, power transformers are generally required to have an operating life of 30 years, but within such a long period of time, there are Corrosion or sagging may occur at the joints, which may cause refrigerant to leak. In such cases, the leakage of refrigerant is a very small amount of force. However, the refrigerant force from each part or joint is
If the leakage into tank 1 continues and accumulates, the refrigerant in the refrigerant circulation circuit will gradually move to the inside of tank J, and the amount of refrigerant flowing through the refrigerant circulation circuit will become insufficient. C2.

For this reason, the windings 4 and 5 due to the refrigerant flowing through the cooling duct 9
The cooling capacity of the transformer decreases, causing the transformer to overheat.
This is a serious problem in terms of operational reliability.

(-) Purpose of the Invention The present invention provides a fuel cell system that prevents the leakage of refrigerant from the components of the cooling circulation circuit in a tank, prevents the accompanying decrease in cooling capacity, allows continuous operation without any trouble, and has high operational reliability. It provides a rate type transformer.

(, f) Summary of the Invention This tank is of a separate type, with a refrigerant reservoir provided at the inner bottom 1 of the tank.

By storing the refrigerant leaking from the components of the refrigerant circulation circuit provided inside the tank, and returning the refrigerant stored in the refrigerant reservoir R to the refrigerant circulation circuit I through the refrigerant return pipe,
This prevents a shortage of refrigerant in the refrigerant circulation circuit due to refrigerant leakage, maintains sufficient cooling capacity, and maintains good transformer operation.

(g) Embodiment 12 of the invention Figure 12 shows an embodiment of the transformer of the present invention.
11 and 11 parts are given the same reference numerals. That is,
In this transformer as well, the tank J'?
Inside the iron core 2. A low-voltage winding 4 and a high-voltage winding 5 are provided, each consisting of a metal sheet 7 and an insulating sheet wrapped in foil. Also, a cooling duct 9 is provided in the winding 4.1. This cooling duct is connected inside the tank 1 via an insulation Δfxa to a liquid guide pipe 1at, and is further connected to a condenser 1o from the liquid guide pipe 1!.

A refrigerant circulation circuit is constructed by sequentially connecting the refrigerant tank 11 and the pump 12.

The entire bottom part 1- of the tank 1 is inclined so that the center part is lower, and a refrigerant reservoir 15 for storing an amount of refrigerant is provided inside the center part of the bottom part 1m. The bottom of this refrigerant reservoir 15 is filled with cold a! For example, two refrigerant tanks 11 are connected via a refrigerant return pipe 16 for returning A to the refrigerant circulation circuit. Further, the refrigerant reservoir 15 is provided with a level detector 12 such as a float switch or an optical level switch that detects the liquid level when the refrigerant level reaches a predetermined height 1:'.

The refrigerant return pipe 16 is provided with an inlet 1# for transferring the refrigerant A in the return direction, and this inlet 11 is driven by a signal from the level detector 17. Note that the refrigerant return pipe 16 is provided with a check valve 19 that prevents the refrigerant A from flowing back in the opposite direction to the return direction, that is, from the refrigerant tank 11 side to the refrigerant reservoir 15 side. ' Therefore, the winding 4.5 provided inside the tongue □1j1
Corrosion or cracks have occurred in the components of the refrigerant circulation circuit such as the cooling duct 9 and liquid guide pipe 13, or the joints between the cooling duct 9 and liquid guide pipe 13 and the insulated pipe ft4. If the refrigerant flowing through each part leaks out from that part, the amount of leaked refrigerant flows down through each part and the winding 4.
reach the inner surface of Furthermore, refrigerant A is at the bottom 1m of tank l.
A refrigerant reservoir 15 that flows on the inner surface and is provided in the center of the bottom 1
Go inside. The refrigerant collected as shown in Fig. 15
When the liquid level of the refrigerant accumulated inside the vehicle reaches a predetermined height, C: Motor holding f V -2k test, 2 k, test force t
s e: ,)aitimu-1□A liquid level height, that is, leaked refrigerant ti:r--'Transformer Guide: 4)'ii-□"□ do.

By the signal from level detector 1r.

-n f1m is driven to transfer the amount of refrigerant accumulated in the refrigerant reservoir 15 into the refrigerant tank 11 through the refrigerant return pipe 16.

The refrigerant transferred into the refrigerant tank gate 11 is sent together with other refrigerant amounts to the cooling duct 1 again by the pump 12, and is then transferred to the winding 4. Cool S. That is, the refrigerant A leaking from the components of the refrigerant circulation circuit provided in the Jl tank 1 is returned to the refrigerant circulation circuit and circulates within the circuit to cool the transformer. Therefore, in the refrigerant circulation circuit, tank 1
Even if there is a leakage of refrigerant A inside the transformer, the cooling capacity does not decrease and the transformer can be cooled by always maintaining the necessary sufficient cooling capacity. Therefore, even if refrigerant A leaks in tank 1 in the refrigerant circulation circuit, transformer □
? It can be operated for a long time without causing any heat. In this embodiment, the liquid level of the amount of refrigerant in the refrigerant reservoir 15 is detected L"t'MAv-in the circulation comb chamber □, ゛・ ,
□ ・□″□Returning can be performed automatically without requiring any management work by one worker.

``Note that instead of using the pump 18 to transfer the refrigerant as described in the previous embodiment, the pressure of the insulating gas sealed in the tank 1 of the transformer is used to transfer the refrigerant from the gas pressure 62. Reservoir 15c: The collected refrigerant A may be force-fed to the refrigerant tank 11 through the refrigerant return pipe 16. In this case, the refrigerant return pipe 16 receives a signal from the level detector 17. A parso or manually operated nozzle is provided to open the refrigerant return pipe 16.

(h) Effects of the Invention The transformer of the present invention stores refrigerant leaking from the components of the refrigerant circulation circuit in the tank and returns it to the refrigerant circulation circuit. There is no decrease in cooling capacity during the process, and good transformer operation can be maintained.

It has excellent long-term operational reliability as a separate/# rate type transformer.

[Brief explanation of the drawing]

FIG. 1 is a vertical sectional view showing a conventional transformer, and FIG. 2 is a vertical sectional view showing an embodiment of the transformer of the present invention. l...tank, 2...iron core, 47m low voltage winding, J
...High voltage winding, 1...metal sheet), 1-insulating sheet. Liao...cooling duct, 1#--condenser, 11-...refrigerant tank, Jj-/nf,! j''・-Liquid guide pipe, 14・-・
Insulation/f-ia", JJ-... Refrigerant reservoir, 1 #-...
Refrigerant return pipe. 17...Level detector, 11...-knob. 111! ! Q

Claims (1)

[Claims] A foil-wound wire made of overlapping metal sheets and insulating sheets is installed inside the tank, and a cooling duct connected to the refrigerant circulation circuit and through which the refrigerant passes is installed. In the transformer, the tank has an internal reservoir, and the refrigerant reservoir is connected to the refrigerant circulation circuit via a refrigerant return pipe that transfers the stored refrigerant.