Stationary induction appliance

Abstract

To provide a stationary induction appliance capable of suppressing deterioration in cooling performance.SOLUTION: A stationary induction appliance includes an iron core and a winding, a tank, a cooler, a first flow path, and a plurality of first blowers. The tank stores insulation gas along with the iron core and the winding. The cooler is arranged outside the tank, and cools the insulation gas. The first flow path is a flow path through which the insulation gas circulates between the tank and the cooler. The plurality of first blowers is installed in the first flow path, and circulates the insulation gas. The insulation gas is a gas with a smaller molecular weight than SF6.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] An embodiment of the present invention relates to a stationary induction motor. [Background technology]

[0002] The stationary induction machine has an iron core, a winding, a tank, and a cooler. The tank contains insulating gas together with the iron core and the winding. The insulating gas cools the iron core and the winding. The cooler cools the insulating gas. The use of naturally occurring gases with low global warming potential as the insulating gas is being considered. However, because naturally occurring gases have a small heat capacity, there are concerns that the cooling performance of the iron core and the winding may decrease. There is a demand for a stationary induction machine that can suppress the decrease in cooling performance. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2002-289439 A Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present invention is to provide a stationary induction motor capable of suppressing a decrease in cooling performance. [Means for solving the problem]

[0005] A stationary induction machine according to a first aspect of the embodiment has an iron core and a winding, a tank, a cooler, a first flow path, and a plurality of first blowers. The tank contains insulating gas together with the iron core and the winding. The cooler is disposed outside the tank and cools the insulating gas. The first flow path is a flow path through which the insulating gas circulates between the tank and the cooler. The plurality of first blowers are disposed in the first flow path and circulate the insulating gas. The insulating gas is a gas having a smaller molecular weight than SF6.

[0006] In a second aspect of the embodiment, in the stationary induction device of the first aspect, a plurality of first blowers are installed in series or in parallel with the first flow path.

[0007] A third aspect of the embodiment is the stationary induction electric appliance of the first or second aspect, further comprising a second flow path and a plurality of second blowers. The second flow path is a flow path through which insulating gas circulates between the inside and the outside of the tank. The plurality of second blowers are installed in the second flow path and circulate the insulating gas.

[0008] In a fourth aspect of the embodiment, in the stationary induction appliance of the third aspect, the number of the second blowers is equal to or greater than the number of the first blowers.

[0009] In a fifth embodiment, the tank is divided into a main chamber in which the iron core and the winding are disposed, and an auxiliary chamber in which the first flow path and the second flow path open, in the stationary induction electric machine of the third or fourth embodiment. An insulating gas is supplied from the auxiliary chamber to the main chamber.

[0010] A sixth aspect of the embodiment is the stationary induction electric device of the third or fourth aspect, further comprising a junction passage where the first passage and the second passage join together outside the tank. The insulating gas flows into the tank from the junction passage. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a schematic configuration diagram of a static induction device according to a first embodiment. [Diagram 2] Graph of blower performance curve and flow path resistance curve. [Diagram 3] FIG. 4 is a schematic configuration diagram of a stationary induction device according to a first modified example of the first embodiment. [Figure 4] FIG. 11 is a schematic configuration diagram of a stationary induction machine according to a second modified example of the first embodiment. [Diagram 5] FIG. 11 is a schematic configuration diagram of a stationary induction machine according to a third modified example of the first embodiment. [Figure 6] FIG. 11 is a schematic configuration diagram of a stationary induction machine according to a fourth modified example of the first embodiment. [Figure 7]FIG. 11 is a schematic configuration diagram of a stationary induction device according to a second embodiment. [Figure 8] FIG. 13 is a schematic configuration diagram of a stationary induction device according to a first modified example of the second embodiment. [Figure 9] FIG. 13 is a schematic configuration diagram of a stationary induction motor according to a second modified example of the second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, a static induction motor according to an embodiment will be described with reference to the drawings. (First embodiment) 1 is a schematic diagram of a static induction motor 1 according to a first embodiment. The static induction motor 1 is, for example, a transformer or a reactor. The static induction motor 1 includes an iron core 2, a winding 3, a tank 5, a cooler 12, a first flow path 10, and a first blower 15. The iron core 2 is made of a metal material such as iron. The winding 3 is formed by winding a wire coaxially around the iron core 2. The wire is made of a conductive metal material such as copper.

[0013] The tank 5 is formed in a cylindrical shape with both ends closed. The tank 5 contains insulating gas together with the iron core 2 and the windings 3. The insulating gas is a gas that has dielectric strength and arc-extinguishing properties. As the insulating gas, a naturally occurring gas is used to replace SF6 (sulfur hexafluoride) gas. The naturally occurring gas has a smaller global warming potential than SF6 gas. The naturally occurring gas is, for example, dry air, N2 gas, CO2 gas, or a mixture of these. The naturally occurring gas has a smaller molecular weight than SF6.

[0014] Heat is generated by the iron core 2 and the windings 3. The insulating gas is a cooling medium that cools the iron core 2 and the windings 3. As the iron core 2 and the windings 3 are cooled, the temperature of the insulating gas rises. The cooler 12 is disposed outside the tank 5 and cools the insulating gas. The first flow path 10 is a flow path through which the insulating gas circulates between the tank 5 and the cooler 12. The cooler 12 exchanges heat between the insulating gas flowing inside the first flow path 10 and air or water flowing outside the first flow path 10. In this way, the cooler 12 cools the insulating gas.

[0015] The first blower 15 is installed in the first flow path 10 and circulates the insulating gas. Both ends of the first flow path 10 are connected to the upper and lower parts of the tank 5. The first blower 15 causes the insulating gas, whose temperature has increased due to cooling of the iron core 2 and the windings 3, to flow from the upper part of the tank 5 to the first flow path 10. The first blower 15 causes the insulating gas, which has been cooled by the cooler 12, to flow from the first flow path 10 to the lower part of the tank 5. The first blower 15 causes the insulating gas to flow from the bottom to the top inside the tank 5. When the insulating gas increases in temperature inside the tank 5, natural convection occurs from the bottom to the top. The first blower 15 does not impede the natural convection of the insulating gas.

[0016] A first partition plate 6 is installed inside the tank 5. The first partition plate 6 separates the upper and lower sections of the tank 5. The first partition plate 6 is disposed between the inner periphery of the tank 5 and the outer periphery of the winding 3. The insulating gas that flows into the lower part of the tank 5 is blocked by the first partition plate 6, passes through the gap between the iron core 2 and the winding 3, and moves to the upper part of the tank 5. As the insulating gas passes through the gap between the iron core 2 and the winding 3, the iron core 2 and the winding 3 are efficiently cooled.

[0017] Natural gases have a smaller heat capacity than SF6 gas. Therefore, there is concern that the cooling performance of the iron core 2 and the windings 3 may be reduced by the insulating gas. One possible method for ensuring cooling performance is to increase the number of coolers 12 to lower the temperature of the insulating gas. However, increasing the number of coolers 12 significantly increases the installation area and cost of the stationary induction motor 1. On the other hand, one possible method is to install multiple first blowers 15 for one cooler 12 to increase the flow rate of the insulating gas. Even if the number of first blowers 15 is increased, the increase in the installation area and cost of the stationary induction motor 1 is small.

[0018] Figure 2 is a graph of the blower's performance curve (PQ characteristics) and the flow path resistance curve. In Figure 2, the performance curve when only one blower is installed is shown by circle dots, the performance curve when two blowers are installed in series is shown by square dots, and the performance curve when two blowers are installed in parallel is shown by triangular dots. When two blowers are installed in series, the static pressure P is twice as high as when only one blower is installed. When two blowers are installed in parallel, the flow rate (air volume) Q is twice as high as when only one blower is installed. The blower can be operated based on the flow rate Q and static pressure P at the intersection of the blower's performance curve and the flow path resistance curve. It can be seen that when two blowers are installed in series or parallel, the flow rate Q increases compared to when only one blower is installed.

[0019] 1, a plurality of first blowers 15 are provided for one cooler 12 in the first flow path 10. In the first embodiment, two first blowers 15 are provided in series for the first flow path 10. The two first blowers 15 are provided upstream of the cooler 12.

[0020] The insulating gas has a smaller molecular weight than SF6 and a smaller heat capacity. Even in this case, the flow rate of the insulating gas is increased by the multiple first blowers 15, so the amount of heat transport from the tank 5 to the cooler 12 increases. This makes it possible to suppress a decrease in the cooling performance of the stationary induction motor 1.

[0021] 3 is a schematic diagram of a stationary induction motor 1 according to a first modified example of the first embodiment. In the first modified example, two first blowers 15 are installed in series with respect to the first flow path 10. The two first blowers 15 are installed downstream of the cooler 12. 4 is a schematic diagram of a stationary induction electric device 1 in a second modified example of the first embodiment. In the second modified example, two first blowers 15 are installed in series with respect to the first flow path 10. Of the two first blowers 15, one is installed upstream of the cooler 12, and the other is installed downstream of the cooler 12.

[0022] 5 is a schematic diagram of a stationary induction motor 1 according to a third modified example of the first embodiment. In the third modified example, two first blowers 15 are installed in parallel with respect to the first flow path 10. The two first blowers 15 are installed upstream of the cooler 12. 6 is a schematic diagram of a stationary induction motor 1 according to a fourth modified example of the first embodiment. In the fourth modified example, two first blowers 15 are installed in parallel with respect to the first flow path 10. The two first blowers 15 are installed downstream of the cooler 12.

[0023] In the first embodiment and its modified example, a plurality of first blowers 15 are installed in series or in parallel with the first flow passage 10. This increases the flow rate of the insulating gas, and therefore increases the amount of heat transport from the tank 5 to the cooler 12. This makes it possible to suppress a decrease in the cooling performance of the stationary induction device 1.

[0024] Second Embodiment 7 is a schematic diagram of the stationary induction electric appliance 1 in the second embodiment. The stationary induction electric appliance 1 in the second embodiment is obtained by adding a second flow path 20 and a second blower 25 to the first embodiment. Descriptions of the second embodiment that are similar to the first embodiment may be omitted.

[0025] The stationary induction motor 1 of the second embodiment has a second flow path 20 and a second blower 25. The second flow path 20 is a flow path through which the insulating gas circulates between the inside and the outside of the tank 5. No cooler is installed in the second flow path 20. Both ends of the second flow path 20 are connected to the upper and lower parts of the tank 5.

[0026] The second blower 25 is installed in the second flow path 20 and circulates the insulating gas. The second blower 25 causes the insulating gas to flow from the upper part of the tank 5 to the second flow path 20. The second blower 25 causes the insulating gas to flow from the second flow path 20 to the lower part of the tank 5.

[0027] A plurality of second blowers 25 are installed in the second flow path 20. In the example of FIG. 7, two second blowers 25 are installed in series with respect to the second flow path 20. The total blowing capacity of the blowers installed in the second flow path 20 is equal to or greater than the total blowing capacity of the blowers installed in the first flow path 10. When the first blower 15 and the second blower 25 are of the same model, the number of the second blowers 25 is equal to or greater than the number of the first blowers 15. In the example of FIG. 7, the number of the first blowers 15 and the number of the second blowers 25 are both two. Even in this case, there is no loss due to a cooler in the second flow path 20, so the flow rate of the second flow path 20 is greater than the flow rate of the first flow path 10.

[0028] The temperature difference between the temperature of the insulating gas present in the upper part of the tank 5 after cooling the iron core 2 and the windings 3 and the temperature of the insulating gas present in the lower part of the tank 5 before cooling the iron core 2 and the windings 3 is Δθ (K). The heat capacity per unit volume of the insulating gas is expressed by the density ρ (kg / m 3 ) and the specific heat Cp (J / kg K). The heat generation amount of the winding is L (W), and the flow rate of the insulating gas inside the tank 5 is Q (m 3 / s). In this case, the following formula 1 holds true. Δθ=(L / ρ Cp) / Q (1)

[0029] 1, the stationary induction device 1 has only the first flow path 10. As an example of this case, the temperature of the insulating gas in the upper part of the tank 5 is 80°C, the temperature of the insulating gas in the lower part of the tank 5 is 60°C, and the temperature difference Δθ is 20°C.

[0030] In the second embodiment shown in FIG. 7, the stationary induction electric device 1 has a second flow path 20 in addition to the first flow path 10. The temperature of the insulating gas flowing from the first flow path 10 into the lower part of the tank 5 is 60°C, as in the first embodiment. The temperature of the insulating gas flowing from the second flow path 20 into the lower part of the tank 5 is 80°C, the same as the temperature of the insulating gas at the upper part of the tank 5. At the lower part of the tank 5, the insulating gas flowing from the first flow path 10 and the second flow path 20 is mixed, and the temperature of the insulating gas becomes 70°C.

[0031] As described above, the flow rate of the second flow path 20 is greater than the flow rate of the first flow path 10. In the second embodiment shown in FIG. 7, the flow rate Q of the insulating gas inside the tank 5 is more than twice as large, for example, 2.5 times larger, as compared with the first embodiment shown in FIG. 1. At this time, the temperature difference Δθ of the insulating gas between the upper and lower parts of the tank 5 is 20° C. / 2.5=8° C. The temperature of the insulating gas in the upper part of the tank 5 is 78° C., which is the temperature difference of 8° C. added to the temperature of the lower part, 70° C. This temperature is lower than the temperature of the upper part of the tank 5, 80° C., in the first embodiment. Therefore, the internal temperature of the tank 5 can be lowered.

[0032] As described above in detail, the stationary induction electric device 1 of the second embodiment has, in addition to the stationary induction electric device 1 of the first embodiment, a second flow path 20 and a plurality of second blowers 25. The second flow path 20 is a flow path through which insulating gas circulates between the inside and the outside of the tank 5. The plurality of second blowers 25 are installed in the second flow path 20 and circulate the insulating gas. The number of the plurality of second blowers 25 is equal to or greater than the number of the plurality of first blowers 15. This increases the flow rate of the insulating gas inside tank 5, thereby improving the cooling performance of core 2 and windings 3.

[0033] In the example of FIG. 7, two first blowers 15 are installed in series on the upstream side of the cooler 12, similar to FIG. 1. Alternatively, two first blowers 15 may be installed in series on the downstream side of the cooler 12, similar to FIG. 3. Furthermore, two first blowers 15 may be installed in series, one on the upstream side and one on the downstream side of the cooler 12, similar to FIG. 4. Furthermore, two first blowers 15 may be installed in parallel on the upstream side of the cooler 12, similar to FIG. 5. Furthermore, two first blowers 15 may be installed in parallel on the downstream side of the cooler 12, similar to FIG. 6.

[0034] FIG. 8 is a schematic diagram of the stationary induction electric device 1 in the first modified example of the second embodiment. The stationary induction electric device 1 in the first modified example has a second partition plate 8. The second partition plate 8 is installed below the iron core 2 and the winding 3 inside the tank 5. The second partition plate 8 divides the inside of the tank 5 into a main chamber 5a and an auxiliary chamber 5b. The iron core 2 and the winding 3 are arranged in the main chamber 5a. The first flow path 10 and the second flow path 20 open into the auxiliary chamber 5b. The second partition plate 8 has an opening (not shown) that communicates the main chamber 5a and the auxiliary chamber 5b. The insulating gas is supplied from the auxiliary chamber 5b to the main chamber 5a through the opening of the second partition plate 8.

[0035] The temperature of the insulating gas flowing into the tank 5 from the first flow path 10 is low. The temperature of the insulating gas flowing into the tank 5 from the second flow path 20 is high. The insulating gas flowing into the tank 5 from the first flow path 10 and the second flow path 20 is mixed in the sub-chamber 5b, the temperature is equalized, and the gas is supplied to the main chamber 5a. This reduces temperature unevenness of the insulating gas passing through the iron core 2 and the windings 3, improving the cooling performance of the iron core 2 and the windings 3.

[0036] 9 is a schematic diagram of a stationary induction device 1 in a second modified example of the second embodiment. The stationary induction device 1 in the first modified example has a junction path 30 where a first flow path 10 and a second flow path 20 join together. The junction path 30 is formed at downstream ends of the first flow path 10 and the second flow path 20. The junction path 30 is connected to a lower part of a tank 50.

[0037] The insulating gas that has flowed through the first flow path 10 and the second flow path 20 is mixed in the junction flow path 30, the temperature is equalized, and the gas flows into the lower part of the tank 5. This reduces temperature unevenness in the insulating gas passing through the iron core 2 and the windings 3, improving the cooling performance of the iron core 2 and the windings 3.

[0038] According to at least one of the embodiments described above, the stationary induction motor 1 includes a plurality of first blowers 15 and an insulating gas having a smaller molecular weight than SF6. This makes it possible to suppress a decrease in the cooling performance of the stationary induction motor 1.

[0039] Although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope of the invention and its equivalents described in the claims, as well as in the scope and spirit of the invention. [Explanation of symbols]

[0040] 1...static induction motor, 2...iron core, 3...winding, 5...tank, 5a...main chamber, 5b...auxiliary chamber, 10...first flow path, 12...cooler, 15...first blower, 20...second flow path, 25...second blower, 30...junction path.

Claims

1. An iron core and a winding; a tank that contains an insulating gas together with the iron core and the winding; a cooler disposed outside the tank and configured to cool the insulating gas; a first flow path through which the insulating gas circulates between the tank and the cooler; a plurality of first blowers installed in the first flow path and circulating the insulating gas; The insulating gas is SF ６ It is a gas with a smaller molecular weight than Stationary induction appliance.

2. The plurality of first blowers are installed in series or in parallel with the first flow path. The static induction motor according to claim 1.

3. a second flow path through which the insulating gas circulates between the inside and the outside of the tank; and a plurality of second blowers installed in the second flow path for circulating the insulating gas. The static induction device according to claim 1 or 2.

4. The number of the second blowers is equal to or greater than the number of the first blowers. The static induction motor according to claim 3.

5. the tank is divided into a main chamber in which the iron core and the winding are disposed, and an auxiliary chamber to which the first flow path and the second flow path open, The insulating gas is supplied from the auxiliary chamber to the main chamber. The static induction motor according to claim 3.

6. a joining passage in which the first passage and the second passage join together is provided outside the tank, The insulating gas flows into the tank from the joint passage. The static induction motor according to claim 3.

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