JPH05275246A - Cooling structure of electromagnetic induction disc winding - Google Patents

Abstract

PURPOSE:To reduce pressure loss when refrigerant flows and to improve heat conduction effect in a circumferential direction of an electromagnetic induction disc winding by making cooling of a unit coil constituting the winding uniform. CONSTITUTION:A disc winding 1 is contained between inside and outside insulating tubes 2, 3, a plurality of horizontal oil ducts are formed radially between unit coils constituting the disc winding 1 to form a plurality of inside and outside vertical oil ducts 8, 7 for flow of refrigerant communicating with each horizontal oil duct, the outside vertical oil duct 7 is blocked by a first pass baffle board 11 fixed across a plurality of unit coils and the inside vertical oil duct 8 is blocked by a second pass baffle board 12 which is fixed apart from the first pass baffle board 11 by a plurality of steps circumferentially. In the cooling structure of the electromagnetic induction disc winding, attachment position of the first and second pass baffle boards 11, 12 is set at a position which is deviated axially by a plurality of steps of the unit coils.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling structure for an electromagnetic induction disk winding used in a transformer or the like, and in particular, cooling is performed by forcibly circulating various cooling media such as insulating oil, SF6 gas or incombustible refrigerant. The present invention relates to a structure that forms an oil passage.

[0002]

2. Description of the Related Art Conventionally, a structure shown in FIG. 7 has been known as a cooling structure for an electromagnetic induction device for forcibly circulating a coolant such as insulating oil to cool a disk winding such as a transformer or a shunt reactor. Has been. That is, the disk winding 1 is housed between the inner insulating cylinder 2 and the outer insulating cylinder 3 provided on the outer side of the iron core, and the unit coils 1a, 1a, ...
Is divided into, for example, about 4 to 8 blocks, and the flow-flow baffle plates 4a and 4b connected to the inner insulating cylinder 2 and the outer insulating cylinder 3 are arranged at the boundary of each block.

According to such a cooling structure, the cooling oil as a refrigerant flowing between the inner insulating cylinder 2 and the outer insulating cylinder 3 is horizontally formed between the unit coils 1a, 1a ... As shown by the arrows. Since it flows in the oil passages a to i in the direction, each unit coil 1a,
The cooling action of 1a ... is enhanced.

[0004]

However, in such a conventional disk winding cooling structure, the flow distribution of the cooling oil in the unit block between the bent-flow baffle plates 4a and 4b is determined by each oil passage a. There is a problem that it is difficult to cool the unit coils 1a, 1a, ...

That is, in the structure shown in FIG. 7, as shown in the correlation graph between the oil passage and the oil flow rate in FIG. The oil flow rate decreases as it gets closer to the inlet, and a phenomenon occurs in which almost no cooling oil flows in the oil passage i closest to the oil inlet. Therefore, there arises a problem that a local overheating phenomenon occurs in each of the unit coils 1a, 1a ....

FIG. 9 is a graph showing the relationship between the flow velocity distribution A of the cooling oil with respect to the oil passages a to i between the unit coils and the temperature distribution B of each part of the winding. The unit coils 1a, 1a ...
There is a large temperature difference between them, and it can be seen that there is a large temperature difference between the temperature of the unit coil near the cooling oil outlet and the temperature of the unit coil near the inlet.

In order to correct such a flow distribution of the cooling oil and the temperature nonuniformity and local overheating which accompany it, the interval between the bent baffle plates 4a and 4b is shortened and a large number of bent baffle plates are provided. However, in this case, the pressure loss at the time of circulating the cooling oil increases, which causes a problem that extra power cost for circulating the cooling oil is required.

In order to deal with the above, for example, Japanese Utility Model Publication No. 55-
No. 6105, a plurality of axial duct rods are inserted between the inner and outer circumferences of the disc winding and the inner and outer insulating cylinders to form a plurality of inner and outer vertical oil passages communicating with a horizontal oil passage. , A first baffle plate and a second baffle plate that alternately close the inner and outer vertical oil passages are provided separately in the axial direction.
Discloses a cooling structure in which the mounting positions of the baffle plates on the adjacent inner and outer vertical oil passages are sequentially shifted in the axial direction.

With such a cooling structure, all the unit coils have a portion having a large cooling effect and a portion having a small cooling effect, so that each unit coil is uniformly cooled and the temperature difference is minimized. The effect is that the maximum temperature of the disk winding is significantly reduced, but in the case of this example, it is necessary to install a subdivided baffle plate for each unit coil, which increases the number of parts. In addition to the drawback that it takes a long time to manufacture, the pressure loss during the circulation of the cooling oil increases, and the baffle plate is subdivided, so that the effect of heat conduction in the winding circumferential direction decreases. There was a problem that it happened.

Therefore, the present invention solves the problems of the conventional cooling structure for the disk windings, facilitates manufacture by suppressing the number of parts to a small number, and uniformly cools each unit coil. It is an object of the present invention to obtain a cooling structure for an electromagnetic induction disk winding, which is capable of reducing the pressure loss during the circulation of cooling oil and enhancing the heat conduction effect in the winding circumferential direction.

[0011]

In order to achieve the above object, the present invention accommodates a disk winding between an inner insulating cylinder and an outer insulating cylinder provided on the outer periphery of an iron core, and the disk winding A plurality of duct pieces are inserted and fixed in the radial direction between the unit coils that form the coil to form a plurality of horizontal oil passages radially, and the inner and outer circumferences of the disc winding and the inner and outer insulating cylinders are formed. A plurality of axial duct rods are inserted between the electromagnetic induction disk winding forming a plurality of inner vertical oil passages and a plurality of outer vertical oil passages for communicating with each horizontal oil passage, The vertical oil passage is closed by a first bent-flow baffle plate fixed across a plurality of unit coils, and the inner vertical oil passage is fixed across a plurality of unit coils, Also, a second fold-flow baffle fixed to the first fold-flow baffle plate by being separated from the first fold-flow baffle plate by a plurality of steps in the circumferential direction. A position in which the mounting positions of the first and second bent flow baffle plates on the outer vertical oil passage and the inner vertical oil passage adjacent to each other are shifted in the axial direction of the inner and outer insulating cylinders by a plurality of stages of unit coils. It has a cooling structure of the electromagnetic induction disk winding set to.

Further, the above-mentioned duct piece is attached with a thickness greater than that of the electric wire and with a radial inclination in the same direction as the flow of the cross-flow section, and the refrigerant of the duct adjacent to the duct piece to which the folding flow baffle plate is fixed. The groove portion is formed along the flow.

[0013]

With this cooling structure, the refrigerant flowing between the inner insulating cylinder and the outer insulating cylinder allows the first vertical flow baffle plate fixed across the plurality of unit coils to form the outer vertical oil passage. The inner vertical oil passage is closed by a second folded flow baffle plate which is closed and is fixed to the first folded flow baffle plate by being separated from the first circumferential flow baffle plate by a plurality of steps in the circumferential direction and straddling a plurality of unit coils. Therefore, the refrigerant flows stepwise along the oil passage in the horizontal direction by using the unit coils of a plurality of stages as one cooling unit.

As a result, the temperature of each unit coil forming the disc winding is distributed over each unit coil by the uniform flow rate distribution of the refrigerant in the unit coil and the heat conduction effect in the circumferential direction of each coil. The temperature distribution becomes substantially uniform, at least local overheating phenomenon does not occur in the unit coil, and the temperature distribution of the entire winding becomes substantially constant.

By mounting the above-mentioned duct piece with a thickness greater than that of the electric wire and with a radial inclination in the same direction as the flow in the cross-flow section, a step drop may occur with respect to the axial tightening load of the winding. Further, since the groove portion along the flow of the refrigerant in the adjacent duct is formed in the duct piece to which the folding flow baffle plate is fixed, the flow velocity distribution of the refrigerant can be made more uniform.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described in detail below with reference to FIGS.

In the figure, 2 is an inner insulating cylinder provided outside the iron core, 3 is an outer insulating cylinder, and the disk winding 1 is housed between the inner insulating cylinder 2 and the outer insulating cylinder 3. The unit coils 1a, 1a, ... Which compose the disc winding 1 are stacked in the axial direction, and these are sequentially connected to form a disk winding.

A plurality of radially extending duct pieces 5, 5 ... Are radially arranged between the unit coils 1a, 1a. The ends and outer ends are the inner and outer circumferences of the disk winding 1 and the inner and outer insulating cylinders 2,
It is fixed to a plurality of axial duct rods 6, 6 inserted between and. In the example of FIG. 1, the circumferential direction of the disc winding 1 is divided into eight equal parts, and the duct pieces 5, 5 ... Are arranged at the respective divided positions.

7 is an outer vertical oil passage formed between each unit coil 1a, 1a ... And the outer insulating cylinder 3, and 8 is between each unit coil 1a, 1a. It is an inner vertical oil passage formed in the. Reference numeral 11 is a first bent-flow baffle plate that closes a predetermined portion of the outer vertical oil passage 7, and 12 is a second bent-flow baffle plate that closes a predetermined portion of the inner vertical oil passage 8. The first and second bent flow baffle plates 11,
12 are unit coils 1a, 1a ...
Fixed across a plurality of (two in the illustrated example). That is, in this example, the bent-flow baffle plates 11 and 12 have a size in which the circumferential direction of the disc winding 1 is divided into four equal parts.

Therefore, horizontal oil passages a, b, c shown in FIG. 4 are formed between the unit coils 1a, 1a. Is a plurality of radial horizontal oil passages a due to the radial duct pieces 5, 5.
It is divided into b, h, d ...
B, C, D, ... are outer vertical oil passages between the inner and outer circumferences of the disk winding 1 and the inner and outer insulating cylinders 2, 3 which are similarly divided by a plurality of axial duct rods 6, 6. 7 and an inner vertical oil passage 8.

As shown in FIGS. 2 and 3, each of the first and second bent flow baffle plates 11 and 12 is formed of a substantially fan-shaped plate made of an insulating material such as a press board. .. and the unit coils 1a, 1a .. The shapes of the first and second baffle plates 11 and 12 are not limited to the above, and other shapes may be used as long as they block one vertical oil passage on the inner and outer circumferences of the disc winding 1. May be

The above-mentioned duct piece 5 is mounted with a radial inclination greater than the thickness of the electric wire so as not to cause a step drop with respect to the axial tightening load of the winding wire. As shown in FIG. 5, the flow is in the same direction as the flow in the crossflow section. And the first and second bent flow baffle plates 11, 1
In the duct piece 5 to which 2 is fixed, a groove portion 5a for circulating cooling oil is formed. The groove 5a may be provided in another duct piece as required.

FIG. 4 is a cross sectional explanatory view in which the vertical cross sections of the divided horizontal oil passage and vertical oil passage are arranged side by side. As shown in FIG. 4, the first diverting baffle plate 11 is a unit. The coils 1a, 1a, ... Are fixed across two unit coils 1a, 1a .. The second folded flow baffle plate 12 is similarly fixed to the horizontal oil passage at the position across the two unit coils 1a, 1a. The second baffle plate 12 is arranged four steps below the first bent-flow baffle plate 11 provided on the horizontal oil passage a, and the first baffle plate 12 is arranged four steps below the second baffle plate 12 by the first step.
The baffle plate 11 of is arranged.

Further, in the horizontal oil passage (b), the first and second baffle plates (11, 12) are arranged so as to be displaced by two steps with respect to the horizontal oil passage (b), and the horizontal oil passages (c) and (d) will be described below. The first and second baffle plates 1 are arranged at positions shifted by two steps each.
1, 12 are arranged. Therefore, when the horizontal oil passage in the lower stage is sequentially moved in four steps in the clockwise direction, the original horizontal oil passage is returned.

In summary of the above construction, the first folding flow baffle plate 11 and the second folding flow baffle plate 12 fixed at a plurality of steps in the circumferential direction are closed to close the first folding flow baffle plate 11 and the first folding flow baffle plate 11. The mounting positions on the inner vertical oil passage 8 and the outer vertical oil passage 7 adjacent to the flow baffle plates 11 and 12 are divided into a plurality of stages of the unit coils 1a, 1a, ... The configuration is such that the positions are shifted.

According to the cooling structure of this embodiment, the cooling oil as a refrigerant flowing between the inner insulating cylinder 2 and the outer insulating cylinder 3 is fixed across the plurality of unit coils. The outer vertical oil passage 7 was closed by the split-flow baffle plate 11, further separated from the first split-flow baffle plate 11 by a plurality of stages in the circumferential direction, and similarly fixed across a plurality of unit coils. Since the inner vertical oil passage 8 is closed by the second folded flow baffle plate 12, the cooling oil is a horizontal oil passage a with a plurality of unit coils 1a, 1a ... As one cooling unit.
Flows in stages along B, H, and D.

FIG. 6 is a graph plotting the temperature changes of the unit coil numbers 1 to 12 which compose the disk winding when the present embodiment is applied. The temperature distribution is substantially uniform over each unit coil. At the same time, it is understood that at least a local overheating phenomenon does not occur with respect to the unit coil. That is, the temperature of each unit coil forming the disk winding is unitized by the uniform distribution of the flow rate of the cooling oil in each unit coil 1a, 1a ... And the heat conduction effect in the circumferential direction of each coil. The local overheating of the coil is prevented, and the temperature distribution of the entire winding is substantially constant.

[0028]

As described above in detail, according to the cooling structure of the electromagnetic induction disk winding according to the present invention, the refrigerant is arranged along the oil passage in the horizontal direction by using a plurality of unit coils as one cooling unit. Since the flow of cooling oil in each unit coil that makes up the winding is made substantially uniform, the heat transfer effect in the circumferential direction of each coil causes the temperature to flow over each unit coil. It is possible to obtain an effect that the distribution becomes substantially uniform, a local overheating phenomenon does not occur in the unit coil, and the temperature distribution of the entire winding becomes substantially constant.

In particular, according to the present invention, it is not necessary to attach a segmental folded baffle plate for each unit coil, and the arrangement interval of the segmented baffle plates can be set appropriately, so that the number of parts can be reduced. There is an effect that the time required for reduction and production is shortened, the pressure loss in the oil passage through which the refrigerant passes is not increased, and extra power cost is not required when the refrigerant is circulated.

Since the above-mentioned duct piece is mounted with a thickness greater than that of the electric wire and with a radial inclination in the same direction as the flow in the cross-flow section, a step drop occurs with respect to the axial tightening load of the winding. Never. Further, by forming a groove along the flow of the refrigerant in the adjacent duct in the duct piece to which the folding flow baffle plate is fixed, it becomes possible to make the flow velocity distribution of the refrigerant more uniform.

[Brief description of drawings]

FIG. 1 is a lateral cross-sectional view of an essential part showing an embodiment of a cooling structure according to the present invention.

FIG. 2 is a plan view of a first bent-flow baffle plate used in this example.

FIG. 3 is a plan view of a second folded flow baffle plate used in this example.

FIG. 4 is a cross-sectional explanatory view in which vertical sections of a divided horizontal oil passage and vertical oil passages are arranged side by side.

FIG. 5 is an enlarged plan view for explaining details of main parts of the present embodiment.

FIG. 6 is a graph in which a temperature change for each unit coil number to which the present embodiment is applied is plotted.

FIG. 7 is a longitudinal sectional view of an essential part showing an example of a conventional oil passage structure.

FIG. 8 is a graph showing a change in oil flow rate with respect to an oil passage in a conventional example.

FIG. 9 is a graph showing a correlation between an oil passage and a flow velocity A and a temperature B in a conventional example.

[Explanation of symbols]

 1 ... Disc winding 1a ... Unit coil 2 ... Inner insulating cylinder 3 ... Outer insulating cylinder 5 ... Duct piece 5a ... Groove part 6 ... Duct rod 7 ... Outer vertical oil passage 8 ... Inner vertical oil passage 11 ... First bent flow Baffle plate 12 ... Second broken flow baffle plate

Claims (2)

[Claims] 1. A disk winding is housed between an inner insulating cylinder and an outer insulating cylinder provided on the outer circumference of an iron core, and a plurality of duct pieces are radially arranged between unit coils forming the disk winding. To form a plurality of horizontal oil passages radially, insert a plurality of axial duct rods between the inner and outer circumferences of the disc winding and the inner insulating cylinder and the outer insulating cylinder, In an electromagnetic induction disk winding forming a plurality of inner vertical oil passages and outer vertical oil passages for refrigerant circulation that communicate with each horizontal oil passage, the outer vertical oil passage straddling a plurality of unit coils. The first vertical flow baffle plate is closed by the first fixed current flow baffle plate, and the inner vertical oil passage is fixed across a plurality of unit coils. The first and second bent-flow baffle plates are closed by a second fixed-flow baffle plate that is separated and fixed. Cooling structure adjacent the mounting position in the outer vertical oil roads and inner vertical oil passage, an electromagnetic induction disk winding, characterized in that set in a plurality of stages shifted by positions of unit coils in the axial direction of the inner and outer insulation cylinder. 2. The duct piece is attached to the duct piece, which is thicker than the electric wire and has a radial inclination in the same direction as the flow of the cross flow section, and the duct baffle plate is fixed to the duct piece adjacent to the duct piece. The cooling structure for an electromagnetic induction disk winding according to claim 1, wherein the flow velocity distribution of the refrigerant is made uniform by forming a groove portion along the flow of.