JPS5889813A - Foil-wound transformer - Google Patents

Abstract

PURPOSE:To ensure excellent refrigeration for a coil lead by a method wherein refrigeration is effected by a heat pipe, provided with a heat exchanger on its top, that runs along the lead. CONSTITUTION:A heat pipe 17 is arranged along a lead 15 with the intermediary of an insulating sheet 3 ensuring good electrical insulation. Second refrigerant 18 is sealed in the heat pipe 17. A heat exchanger 19 is situated at the upper part of the heat pipe 17 and is connected to an adjacent refrigerant duct 6 and liquid collecting tube 10 with the intermediary of an insulator pipe 11. The heat exchanger 19 is composed of a finned radiator 20 located at the upper part of the heat pipe 17 and a shell 21. Refrigerant 14 flows out of the near-by refrigerant duct 6 and through the space formed by the radiator 20 and shell 21, for the refrigeration of the heat pipe 17. The second refrigerant 18 enclosed in the heat pipe 17 is vaporized while travelling along the lead 15 to be condensed in the heat exchanger 19. The device being thus constructed, temperatures are the same on the surface along the most of the length of the heat pipe 17, ensuring excellent refrigeration along the entire length of the lead 15.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a foil-wound transformer in which a cooling duct is built into a coil formed by overlappingly wound a foil-like conductor and an insulating sheet.

Conventional technology and its problems Foil-wound transformers have the advantage of being smaller and lighter than transformers using linear conductors because the wound conductor has a good space factor. High-voltage, large-capacity transformer 4: Applicable 42 needs to improve the cooling capacity of the coil ζ2 and provide the coil with high insulation capacity, so a cooling duct through which refrigerant flows is built into the coil. , is configured to directly cool the heat generated from the conductor of the coil.

This kind of conventional foil-wound transformer has: As shown in Fig.
) are wound in layers to form a coil body, and this coil body consists of a low-voltage coil (4) and a high-voltage fill (5), each of which has a built-in annular cooling duct (6). ing. This cooling duct reef has a narrow gap R-1
It is filled with cold #&I such as No. 13 or FC-75, and is flushed by the pump (7), thereby removing the Joule heat generated within the foil wrapping 1 ile. Refrigerant I, whose temperature has increased by absorbing heat, is cooled by cooling water (8) in an external cooler (8).
9) and sent into the duct again.

The liquid collection pipe (II is made of metal such as stainless steel, but in order to connect it to the cooling duct, 4 = insulated pipe aυ
is used, so the liquid collecting pipe takes the ground potential of the tank υ, etc. On the other hand, the cooling duct and coil are t! They have the same potential, and insulation between them and the outside is done by SF6 gas Q3 sealed in the tank. Each coil (
4), (5) Inside and outside the chamber, there are lead wires a! that introduce or derive power from the outside to each fill. 9 is provided.

The foil-wound transformer described above is called a separate foil-wound transformer because the circulation circuit through which the refrigerant flows for cooling and the insulator α1 for insulation are completely separated. It is possible to significantly reduce the size of the board, with insulation W4
It has advantages such as high performance.

However, in conventional foil-wound transformers, the leads 5ias for introducing or deriving power from the outside are shown in Figure 3 (
2. A bevel 4 is provided at the end of the foil conductor (2) constituting each coil as shown in Figure 2, but the current density at ζH is higher than that of the coil, so the amount of heat generated is large. There was a problem that the series lead wire part could not be cooled sufficiently due to the fact that a gap was created between the turn coil and the turn coil.

An object of the present invention is to provide a foil-wound transformer whose lead wire portions are sufficiently cooled.

Summary of the invention A heat pipe having a heat exchanger on the upper part is disposed along a lead wire, and is cooled by a refrigerant flowing out from an adjacent cooling duct (2), thereby solving the above problems.

Effects of the Invention According to the present invention, the lead wire of the coil can be cooled well.

Embodiments of the Invention Examples of the invention will now be described with reference to FIGS. 3 and 4. Note that the same parts as in the conventional example are given the same numbers and their explanations are omitted. FIG. 3 is a diagram showing the positional relationship between the heat pipe and the lead wire according to the first aspect of the present invention. It is set up. ′
A second refrigerant Ql is sealed inside the heat pipe. The upper part 12 of the heat pipe is shown in Figure 4 (= shown, 6
= A heat exchanger is provided, and an adjacent cooling duct (
6) and a liquid collecting pipe (IQ is connected via an insulated pipe αυ.The heat exchanger U consists of a heat dissipating member with fins at the upper part of the heat pipe and a shell <21), and is formed by these 62. Refrigerant I flowing out from the adjacent cooling duct flows through the space, cooling the heat nozzle.

According to the embodiment ζ of the present invention, the second refrigerant 4 enclosed in the heat/(eve a7) evaporates in the part along the lead-a94: and condenses in the heat exchanger 00 part. Most of the heat nozzle surface along at2 is in the longitudinal direction C.
: Habo same 1! In this case, the entire length of the lead wire can be used for two cooling purposes.Also 4: Since the refrigerant flowing out from the cooling duct is used to cool the heat pipe, a special cooling system is prepared. It also has the advantage of being simple in structure.

[Brief explanation of drawings]

Fig. 131 is a diagram showing a conventional foil-wound transformer, Fig. 2 is a partially enlarged view of a conventional lead wire section, and Fig. 3 is a partially enlarged view of a lead wire section according to the steaming invention. - Diagram showing the cross section of the beam, w
! FIG. 14 is a diagram showing a lead cooling section according to the present invention. 2... Foil conductor, 3... Insulating sheet 6...
・Cooling duct), 11... Insulated pipe 15... Lead wire, 17... Heat biply... Heat exchanger. Agent: Patent Attorney Noriyuki Jun (and 1 other person) No. 1
Figure 2

Claims (1)

[Claims] In a foil-wound transformer, which has a built-in cooling duct through which refrigerant flows inside the coil, which is made by wrapping a metal conductor and an insulating sheet overlappingly around the outside of the iron core, the upper heat exchanger is connected by running the lead wires of the coil (2) along the coil. 1. A foil-wound transformer, characterized in that the heat exchanger is provided with a heat pipe, and the heat exchanger is cooled by a refrigerant flowing out from an adjacent cooling duct.