JPS6113365B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a naturally cooled induction electric appliance winding, and more particularly to a structure for introducing cooling oil into a disk winding or a helical winding in a naturally cooled transformer or a naturally cooled reactor.

Figure 1 shows the structure of a conventional naturally cooled transformer disk winding with folding plates. A disc winding 4 is constructed by stacking coils 2 wound in a plate shape around an iron core 1 in the height direction with horizontal oil pipes 3 of a predetermined height interposed between the coils 2, each having inner and outer insulation. It is arranged between the cylinders 7 and 8 so as to form the inner and outer vertical oil passages 5 and 6 therebetween, and further closes the inner and outer vertical oil passages 5 and 6 alternately for every predetermined number of coils. A folding plate 9 is provided.

In the disk winding 4 in which such a folding plate 9 is arranged, the oil rising in the inner or outer vertical oil passages 5 and 6 is directed to the horizontal oil passage 3 between each coil as shown by the arrow in FIG. The oil flows in a zigzag pattern to cool each coil 2, but since the flow speed of the oil flowing through the horizontal oil pipe 3 is extremely slow, it is difficult to accurately measure the flow speed. It was not possible to determine the flow velocity distribution between each horizontal oilway in the diversion section between the two.

However, recently, a laser current meter that can accurately measure the flow velocity of low-velocity fluid without contact has been commercialized, so we used this laser current meter to measure the flow velocity of oil flowing through each horizontal oilway in the diversion section. However, the flow velocity distribution between each horizontal oil pipe is
As shown by curve V in the figure, it is faster at the bottom of the diversion section and slower at the top of the diversion section (in this case, since the height dimensions of each horizontal oilway are equal to each other, the distance between each horizontal oilway is (The flow rate distribution becomes similar to the flow velocity distribution), and as a result, the temperature of each coil 2 becomes significantly uneven at the lower and upper parts of the folded flow section, as shown by the curve W, especially in the folded flow section where the flow velocity is low. It was found that there is a tendency for localized high temperatures to occur in the upper part of the area.

The present invention has been made in view of this point, and its object is to provide a naturally cooled induction electric winding that can prevent local temperature increases in the coil with a simple configuration.

In order to achieve this object, the present invention is characterized in that the height dimension of the horizontal oilway located on the upper side is made larger than the height dimension of the horizontal oilway located on the lower side within the diversion section. .

Hereinafter, the present invention will be explained in detail based on each illustrated embodiment. In each figure showing each embodiment, the same reference numerals as in FIGS. 1 and 2 indicate the same or equivalent parts.

FIG. 4 shows an embodiment of the present invention, in which the entire disc-shaped winding formed by stacking a plurality of coils 2 in the height direction is connected to the inner and outer vertical oil passages 5, 6 by folding plates 9. This figure shows one folded flow section in the case where the folded flow sections are divided into a plurality of folded flow sections by alternately closing . Each of the horizontal oil passages 3 between the coils 2 in the folded flow section is configured to vary its height in order to adjust the oil flow velocity. That is, in this embodiment, within one folded flow section, there are an area B extending from the center to the upper part and an area A extending from the lower part to the center.
The height of the horizontal oil passage 3 between the several coils 2 in area A is smaller than the height of the horizontal oil passage 3 between the coils 2 in area B.

In this way, during the natural circulation of oil, the flow velocity that was small in the horizontal oil pipe 3 at the upper part of the diversion section can be increased, and the flow velocity that was large in the horizontal oil pipe 3 at the bottom of the diversion section can be reduced. As shown in the figure, the flow velocity distribution (curve
V ₁ ) is shown in Figure 3, which is the conventional flow velocity distribution (curve V).
The temperature distribution (curve W ₁ ) of each coil 2 can be made more uniform by effectively cooling each coil 2. The temperature distribution can be made more uniform compared to the conventional temperature distribution (curve W) shown in FIG. Also,
When the height dimension of each horizontal oilway is changed as described above, the flow cross-sectional area of the horizontal oilway 3 in the upper part of the diversion section becomes larger than the flow cross-section area of the horizontal oilway 3 in the lower part of the diversion section. The flow rate distribution between the horizontal oil pipes is also made uniform from this point of view, and together with the above-described uniformity of the flow velocity distribution (flow rate distribution), the temperature distribution of each coil 2 can also be made uniform.

FIG. 6 shows another embodiment of the present invention, and similarly to FIG. 4, it shows one folded section when the entire disk winding is divided into several folded sections. In this embodiment, the diversion section is divided into three regions: a lower region C, a central region D, and an upper region E, and the height dimension of the horizontal oil pipe 3 between the coils 2 in the lower region C is set to the maximum. The height dimension of the horizontal oil pipe 3 is gradually increased from the region D to the region E.

In this way, as shown by curve V ₂ in FIG. 7, the flow velocity distribution in the folded flow section is further made uniform, and good cooling is performed, and the temperature rise of each coil 2 is as shown by curve W ₂ . In addition, similar to the embodiment described above, the flow rate distribution between the horizontal oil pipes can be made more uniform based on the change in the height dimension of each horizontal oil pipe, that is, the flow cross-sectional area. In addition to making the flow velocity distribution (flow rate distribution) uniform, the temperature distribution of each coil 2 can also be made uniform.

Further, FIG. 8 shows still another embodiment of the present invention, and shows two folded sections when the entire disk winding is divided into two or more folded sections. In a naturally cooled transformer, when a disc-shaped winding is divided into multiple folded flow sections, if the number of folded flow sections is too large, the pressure loss of the oil flow in the winding section increases and the circulation flow rate decreases. This will impair the cooling effect, and if the number of diversion sections is too small, the total cross-sectional area of the horizontal oilway within one diversion section will increase, and as a result, the flow velocity flowing through the horizontal oilway 3 will decrease. There is a possibility that it will be difficult to bring the temperature of the coil 2 below a predetermined temperature rise value. Therefore, in this embodiment, in order to achieve a uniform temperature rise in the entire winding with as few number of folded sections as possible, the number of two coils in the folded section is gradually increased from the bottom to the top of the winding. In addition, the height dimension of the horizontal oil pipe 3 between each coil 2 in each fold section is changed in the same way as in the embodiment of FIG. 4 or FIG. 6. It is configured by letting. That is, in this embodiment, in the lower folded flow section where there are many coils, the area F,
It is divided into three regions G and H, and the height of the horizontal oil pipe 3 is gradually increased from region F to region H, and in the upper flow section where the number of coils is small, regions I and J The height dimension of the horizontal oil pipe 3 in the upper region J is divided into two regions, and the height dimension of the horizontal oil pipe 3 in the upper region J is divided into two regions.
The height dimension of the horizontal oil pipe 3 is larger than that of the horizontal oil pipe 3.

As a result, as in each of the embodiments described above, the flow velocity distribution and the flow rate distribution between the horizontal oil pipes 3 in each diversion section are made uniform, and the average of each horizontal oil conduit 3 in the diversion section above the winding is made uniform. Since the flow velocity can be made higher than that of each horizontal oil passage in the folded flow section at the bottom of the winding, even if the temperature of the oil that cooled each coil 2 rises from the bottom of the winding to the top, the disk The temperature rise of the coil 2 between each folded section of the shaped winding and within each folded section can be made uniform, and the cooling efficiency of the entire winding can be improved.

In the embodiment shown in FIG. 8, if the average flow velocity in the horizontal oil pipe 3 in the upper fold section is sufficiently large and the temperature rise of the coil 2 has a margin with respect to the specified value, the fold It is also possible to make the height dimension of each horizontal oilway 3 the same size only in the section.

Furthermore, instead of changing the height dimension of each horizontal oil pipe 3 in the folded flow section for each area including a plurality of coils 2 as described above, By sequentially increasing the height of the oil pipes 3, the flow velocity distribution and flow rate distribution of each horizontal oil pipe can be made more uniform.

As explained above, according to the present invention, it is possible to equalize the temperature distribution of each coil, prevent a local temperature rise in the coil, and significantly improve the cooling efficiency of the entire winding. It becomes possible.

[Brief explanation of the drawing]

Fig. 1 is a vertical cross-sectional view showing the schematic structure of a conventional naturally cooled transformer disk winding, and Fig. 2 is a flow state of oil flowing within one fold section of the disk winding shown in Fig. 1. FIG. 3 is a characteristic diagram showing the oil flow velocity distribution and coil temperature distribution in the folded flow section shown in FIG. 2, and FIG. FIG. 5 is a longitudinal cross-sectional view showing one folded flow section of the plate winding, FIG. 5 is a characteristic diagram showing the oil flow velocity distribution and coil temperature distribution in the folded flow section shown in FIG. 4, and FIG. FIG. 7 is a longitudinal cross-sectional view showing one folded flow section of the disk winding of a naturally cooled transformer according to the embodiment, and FIG. 7 is a characteristic showing the oil flow velocity distribution and coil temperature distribution within the folded flow section shown in FIG. 6. 8 are longitudinal sectional views showing two folded flow sections of a naturally cooled transformer according to still another embodiment of the present invention. 2...Coil, 3...Horizontal oil pipe, 5...Inner vertical oil pipe, 6...Outer vertical oil pipe, 7...Inner insulating tube, 8...Outer insulating tube, 9...Folding plate, A ~J…
...Each area of the folded flow section.

Claims (1)

[Claims] 1. A plurality of coils are stacked in the height direction via horizontal oil pipes to form a disc-shaped winding, and this disc-shaped winding is arranged between inner and outer insulating cylinders. Inner and outer vertical oil passages are formed between the disc-shaped winding and each insulating cylinder, and the inner and outer vertical oil passages are alternately closed by folding plates for each predetermined number of coils to form folded flow sections. A naturally cooled induction electric appliance winding characterized in that the height of the horizontal oil pipe located on the upper side of the folded flow section is larger than the height of the horizontal oil pipe located on the lower side. 2 In claim 1, the folded flow section is divided into a plurality of regions in the height direction, and the height dimensions of the horizontal oil pipes in each region are equal to each other, and the horizontal oil pipes in the upper region are A naturally cooled induction electric winding characterized in that the height dimension of is larger than the height dimension of the horizontal oil pipe in the lower region. 3. The naturally cooled induction electric winding according to claim 1, wherein the height dimension of each horizontal oilway in the folded flow section is gradually increased from the bottom to the top. 4. In claim 1 or 2, the folded flow sections are plural, and the number of coils arranged in the upper folded flow section is greater than the number of coils arranged in the lower folded flow section. A naturally cooled induction electric winding wire characterized by a reduced amount of heat.